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// Code generated by golang.org/x/tools/cmd/bundle. DO NOT EDIT.
//go:generate bundle -o h2_bundle.go -prefix http2 -underscore golang.org/x/net/http2
// Package http2 implements the HTTP/2 protocol.
//
// This package is low-level and intended to be used directly by very
// few people. Most users will use it indirectly through the automatic
// use by the net/http package (from Go 1.6 and later).
// For use in earlier Go versions see ConfigureServer. (Transport support
// requires Go 1.6 or later)
//
// See https://http2.github.io/ for more information on HTTP/2.
//
// See https://http2.golang.org/ for a test server running this code.
//
package http
import (
"bufio"
"bytes"
"compress/gzip"
"context"
"crypto/rand"
"crypto/tls"
"encoding/binary"
"errors"
"fmt"
"io"
"io/ioutil"
"log"
"math"
mathrand "math/rand"
"net"
"net/http/httptrace"
"net/textproto"
"net/url"
"os"
"reflect"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"time"
"internal/x/net/http/httpguts"
"internal/x/net/http2/hpack"
"internal/x/net/idna"
)
// A list of the possible cipher suite ids. Taken from
// https://www.iana.org/assignments/tls-parameters/tls-parameters.txt
const (
http2cipher_TLS_NULL_WITH_NULL_NULL uint16 = 0x0000
http2cipher_TLS_RSA_WITH_NULL_MD5 uint16 = 0x0001
http2cipher_TLS_RSA_WITH_NULL_SHA uint16 = 0x0002
http2cipher_TLS_RSA_EXPORT_WITH_RC4_40_MD5 uint16 = 0x0003
http2cipher_TLS_RSA_WITH_RC4_128_MD5 uint16 = 0x0004
http2cipher_TLS_RSA_WITH_RC4_128_SHA uint16 = 0x0005
http2cipher_TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5 uint16 = 0x0006
http2cipher_TLS_RSA_WITH_IDEA_CBC_SHA uint16 = 0x0007
http2cipher_TLS_RSA_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0008
http2cipher_TLS_RSA_WITH_DES_CBC_SHA uint16 = 0x0009
http2cipher_TLS_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x000A
http2cipher_TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x000B
http2cipher_TLS_DH_DSS_WITH_DES_CBC_SHA uint16 = 0x000C
http2cipher_TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA uint16 = 0x000D
http2cipher_TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x000E
http2cipher_TLS_DH_RSA_WITH_DES_CBC_SHA uint16 = 0x000F
http2cipher_TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x0010
http2cipher_TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0011
http2cipher_TLS_DHE_DSS_WITH_DES_CBC_SHA uint16 = 0x0012
http2cipher_TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA uint16 = 0x0013
http2cipher_TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0014
http2cipher_TLS_DHE_RSA_WITH_DES_CBC_SHA uint16 = 0x0015
http2cipher_TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0x0016
http2cipher_TLS_DH_anon_EXPORT_WITH_RC4_40_MD5 uint16 = 0x0017
http2cipher_TLS_DH_anon_WITH_RC4_128_MD5 uint16 = 0x0018
http2cipher_TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA uint16 = 0x0019
http2cipher_TLS_DH_anon_WITH_DES_CBC_SHA uint16 = 0x001A
http2cipher_TLS_DH_anon_WITH_3DES_EDE_CBC_SHA uint16 = 0x001B
// Reserved uint16 = 0x001C-1D
http2cipher_TLS_KRB5_WITH_DES_CBC_SHA uint16 = 0x001E
http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_SHA uint16 = 0x001F
http2cipher_TLS_KRB5_WITH_RC4_128_SHA uint16 = 0x0020
http2cipher_TLS_KRB5_WITH_IDEA_CBC_SHA uint16 = 0x0021
http2cipher_TLS_KRB5_WITH_DES_CBC_MD5 uint16 = 0x0022
http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_MD5 uint16 = 0x0023
http2cipher_TLS_KRB5_WITH_RC4_128_MD5 uint16 = 0x0024
http2cipher_TLS_KRB5_WITH_IDEA_CBC_MD5 uint16 = 0x0025
http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA uint16 = 0x0026
http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_SHA uint16 = 0x0027
http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_SHA uint16 = 0x0028
http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5 uint16 = 0x0029
http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_MD5 uint16 = 0x002A
http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_MD5 uint16 = 0x002B
http2cipher_TLS_PSK_WITH_NULL_SHA uint16 = 0x002C
http2cipher_TLS_DHE_PSK_WITH_NULL_SHA uint16 = 0x002D
http2cipher_TLS_RSA_PSK_WITH_NULL_SHA uint16 = 0x002E
http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA uint16 = 0x002F
http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA uint16 = 0x0030
http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA uint16 = 0x0031
http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA uint16 = 0x0032
http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA uint16 = 0x0033
http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA uint16 = 0x0034
http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0035
http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA uint16 = 0x0036
http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0037
http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA uint16 = 0x0038
http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA uint16 = 0x0039
http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA uint16 = 0x003A
http2cipher_TLS_RSA_WITH_NULL_SHA256 uint16 = 0x003B
http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x003C
http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x003D
http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA256 uint16 = 0x003E
http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x003F
http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA256 uint16 = 0x0040
http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0041
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0042
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0043
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0044
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0045
http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA uint16 = 0x0046
// Reserved uint16 = 0x0047-4F
// Reserved uint16 = 0x0050-58
// Reserved uint16 = 0x0059-5C
// Unassigned uint16 = 0x005D-5F
// Reserved uint16 = 0x0060-66
http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0x0067
http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA256 uint16 = 0x0068
http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x0069
http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA256 uint16 = 0x006A
http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 uint16 = 0x006B
http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA256 uint16 = 0x006C
http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA256 uint16 = 0x006D
// Unassigned uint16 = 0x006E-83
http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0084
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0085
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0086
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0087
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0088
http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA uint16 = 0x0089
http2cipher_TLS_PSK_WITH_RC4_128_SHA uint16 = 0x008A
http2cipher_TLS_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0x008B
http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA uint16 = 0x008C
http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA uint16 = 0x008D
http2cipher_TLS_DHE_PSK_WITH_RC4_128_SHA uint16 = 0x008E
http2cipher_TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0x008F
http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA uint16 = 0x0090
http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA uint16 = 0x0091
http2cipher_TLS_RSA_PSK_WITH_RC4_128_SHA uint16 = 0x0092
http2cipher_TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0x0093
http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA uint16 = 0x0094
http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA uint16 = 0x0095
http2cipher_TLS_RSA_WITH_SEED_CBC_SHA uint16 = 0x0096
http2cipher_TLS_DH_DSS_WITH_SEED_CBC_SHA uint16 = 0x0097
http2cipher_TLS_DH_RSA_WITH_SEED_CBC_SHA uint16 = 0x0098
http2cipher_TLS_DHE_DSS_WITH_SEED_CBC_SHA uint16 = 0x0099
http2cipher_TLS_DHE_RSA_WITH_SEED_CBC_SHA uint16 = 0x009A
http2cipher_TLS_DH_anon_WITH_SEED_CBC_SHA uint16 = 0x009B
http2cipher_TLS_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009C
http2cipher_TLS_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009D
http2cipher_TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x009E
http2cipher_TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x009F
http2cipher_TLS_DH_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0x00A0
http2cipher_TLS_DH_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0x00A1
http2cipher_TLS_DHE_DSS_WITH_AES_128_GCM_SHA256 uint16 = 0x00A2
http2cipher_TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 uint16 = 0x00A3
http2cipher_TLS_DH_DSS_WITH_AES_128_GCM_SHA256 uint16 = 0x00A4
http2cipher_TLS_DH_DSS_WITH_AES_256_GCM_SHA384 uint16 = 0x00A5
http2cipher_TLS_DH_anon_WITH_AES_128_GCM_SHA256 uint16 = 0x00A6
http2cipher_TLS_DH_anon_WITH_AES_256_GCM_SHA384 uint16 = 0x00A7
http2cipher_TLS_PSK_WITH_AES_128_GCM_SHA256 uint16 = 0x00A8
http2cipher_TLS_PSK_WITH_AES_256_GCM_SHA384 uint16 = 0x00A9
http2cipher_TLS_DHE_PSK_WITH_AES_128_GCM_SHA256 uint16 = 0x00AA
http2cipher_TLS_DHE_PSK_WITH_AES_256_GCM_SHA384 uint16 = 0x00AB
http2cipher_TLS_RSA_PSK_WITH_AES_128_GCM_SHA256 uint16 = 0x00AC
http2cipher_TLS_RSA_PSK_WITH_AES_256_GCM_SHA384 uint16 = 0x00AD
http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0x00AE
http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0x00AF
http2cipher_TLS_PSK_WITH_NULL_SHA256 uint16 = 0x00B0
http2cipher_TLS_PSK_WITH_NULL_SHA384 uint16 = 0x00B1
http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0x00B2
http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0x00B3
http2cipher_TLS_DHE_PSK_WITH_NULL_SHA256 uint16 = 0x00B4
http2cipher_TLS_DHE_PSK_WITH_NULL_SHA384 uint16 = 0x00B5
http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0x00B6
http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0x00B7
http2cipher_TLS_RSA_PSK_WITH_NULL_SHA256 uint16 = 0x00B8
http2cipher_TLS_RSA_PSK_WITH_NULL_SHA384 uint16 = 0x00B9
http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BA
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BB
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BC
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BD
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BE
http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0x00BF
http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C0
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C1
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C2
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C3
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C4
http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA256 uint16 = 0x00C5
// Unassigned uint16 = 0x00C6-FE
http2cipher_TLS_EMPTY_RENEGOTIATION_INFO_SCSV uint16 = 0x00FF
// Unassigned uint16 = 0x01-55,*
http2cipher_TLS_FALLBACK_SCSV uint16 = 0x5600
// Unassigned uint16 = 0x5601 - 0xC000
http2cipher_TLS_ECDH_ECDSA_WITH_NULL_SHA uint16 = 0xC001
http2cipher_TLS_ECDH_ECDSA_WITH_RC4_128_SHA uint16 = 0xC002
http2cipher_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC003
http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA uint16 = 0xC004
http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA uint16 = 0xC005
http2cipher_TLS_ECDHE_ECDSA_WITH_NULL_SHA uint16 = 0xC006
http2cipher_TLS_ECDHE_ECDSA_WITH_RC4_128_SHA uint16 = 0xC007
http2cipher_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC008
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA uint16 = 0xC009
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA uint16 = 0xC00A
http2cipher_TLS_ECDH_RSA_WITH_NULL_SHA uint16 = 0xC00B
http2cipher_TLS_ECDH_RSA_WITH_RC4_128_SHA uint16 = 0xC00C
http2cipher_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC00D
http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA uint16 = 0xC00E
http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA uint16 = 0xC00F
http2cipher_TLS_ECDHE_RSA_WITH_NULL_SHA uint16 = 0xC010
http2cipher_TLS_ECDHE_RSA_WITH_RC4_128_SHA uint16 = 0xC011
http2cipher_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC012
http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA uint16 = 0xC013
http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA uint16 = 0xC014
http2cipher_TLS_ECDH_anon_WITH_NULL_SHA uint16 = 0xC015
http2cipher_TLS_ECDH_anon_WITH_RC4_128_SHA uint16 = 0xC016
http2cipher_TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA uint16 = 0xC017
http2cipher_TLS_ECDH_anon_WITH_AES_128_CBC_SHA uint16 = 0xC018
http2cipher_TLS_ECDH_anon_WITH_AES_256_CBC_SHA uint16 = 0xC019
http2cipher_TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC01A
http2cipher_TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA uint16 = 0xC01B
http2cipher_TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA uint16 = 0xC01C
http2cipher_TLS_SRP_SHA_WITH_AES_128_CBC_SHA uint16 = 0xC01D
http2cipher_TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA uint16 = 0xC01E
http2cipher_TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA uint16 = 0xC01F
http2cipher_TLS_SRP_SHA_WITH_AES_256_CBC_SHA uint16 = 0xC020
http2cipher_TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA uint16 = 0xC021
http2cipher_TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA uint16 = 0xC022
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC023
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC024
http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC025
http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC026
http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC027
http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC028
http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256 uint16 = 0xC029
http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384 uint16 = 0xC02A
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC02B
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC02C
http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC02D
http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC02E
http2cipher_TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC02F
http2cipher_TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC030
http2cipher_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 uint16 = 0xC031
http2cipher_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384 uint16 = 0xC032
http2cipher_TLS_ECDHE_PSK_WITH_RC4_128_SHA uint16 = 0xC033
http2cipher_TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA uint16 = 0xC034
http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA uint16 = 0xC035
http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA uint16 = 0xC036
http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256 uint16 = 0xC037
http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384 uint16 = 0xC038
http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA uint16 = 0xC039
http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA256 uint16 = 0xC03A
http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA384 uint16 = 0xC03B
http2cipher_TLS_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC03C
http2cipher_TLS_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC03D
http2cipher_TLS_DH_DSS_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC03E
http2cipher_TLS_DH_DSS_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC03F
http2cipher_TLS_DH_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC040
http2cipher_TLS_DH_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC041
http2cipher_TLS_DHE_DSS_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC042
http2cipher_TLS_DHE_DSS_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC043
http2cipher_TLS_DHE_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC044
http2cipher_TLS_DHE_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC045
http2cipher_TLS_DH_anon_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC046
http2cipher_TLS_DH_anon_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC047
http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC048
http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC049
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC04A
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC04B
http2cipher_TLS_ECDHE_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC04C
http2cipher_TLS_ECDHE_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC04D
http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC04E
http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC04F
http2cipher_TLS_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC050
http2cipher_TLS_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC051
http2cipher_TLS_DHE_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC052
http2cipher_TLS_DHE_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC053
http2cipher_TLS_DH_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC054
http2cipher_TLS_DH_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC055
http2cipher_TLS_DHE_DSS_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC056
http2cipher_TLS_DHE_DSS_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC057
http2cipher_TLS_DH_DSS_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC058
http2cipher_TLS_DH_DSS_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC059
http2cipher_TLS_DH_anon_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC05A
http2cipher_TLS_DH_anon_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC05B
http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC05C
http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC05D
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC05E
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC05F
http2cipher_TLS_ECDHE_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC060
http2cipher_TLS_ECDHE_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC061
http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC062
http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC063
http2cipher_TLS_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC064
http2cipher_TLS_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC065
http2cipher_TLS_DHE_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC066
http2cipher_TLS_DHE_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC067
http2cipher_TLS_RSA_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC068
http2cipher_TLS_RSA_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC069
http2cipher_TLS_PSK_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC06A
http2cipher_TLS_PSK_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC06B
http2cipher_TLS_DHE_PSK_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC06C
http2cipher_TLS_DHE_PSK_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC06D
http2cipher_TLS_RSA_PSK_WITH_ARIA_128_GCM_SHA256 uint16 = 0xC06E
http2cipher_TLS_RSA_PSK_WITH_ARIA_256_GCM_SHA384 uint16 = 0xC06F
http2cipher_TLS_ECDHE_PSK_WITH_ARIA_128_CBC_SHA256 uint16 = 0xC070
http2cipher_TLS_ECDHE_PSK_WITH_ARIA_256_CBC_SHA384 uint16 = 0xC071
http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC072
http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC073
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC074
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC075
http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC076
http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC077
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC078
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC079
http2cipher_TLS_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC07A
http2cipher_TLS_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC07B
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC07C
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC07D
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC07E
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC07F
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC080
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC081
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC082
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC083
http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC084
http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC085
http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC086
http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC087
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC088
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC089
http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC08A
http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC08B
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC08C
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC08D
http2cipher_TLS_PSK_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC08E
http2cipher_TLS_PSK_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC08F
http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC090
http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC091
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_GCM_SHA256 uint16 = 0xC092
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_GCM_SHA384 uint16 = 0xC093
http2cipher_TLS_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC094
http2cipher_TLS_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC095
http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC096
http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC097
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC098
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC099
http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_128_CBC_SHA256 uint16 = 0xC09A
http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_256_CBC_SHA384 uint16 = 0xC09B
http2cipher_TLS_RSA_WITH_AES_128_CCM uint16 = 0xC09C
http2cipher_TLS_RSA_WITH_AES_256_CCM uint16 = 0xC09D
http2cipher_TLS_DHE_RSA_WITH_AES_128_CCM uint16 = 0xC09E
http2cipher_TLS_DHE_RSA_WITH_AES_256_CCM uint16 = 0xC09F
http2cipher_TLS_RSA_WITH_AES_128_CCM_8 uint16 = 0xC0A0
http2cipher_TLS_RSA_WITH_AES_256_CCM_8 uint16 = 0xC0A1
http2cipher_TLS_DHE_RSA_WITH_AES_128_CCM_8 uint16 = 0xC0A2
http2cipher_TLS_DHE_RSA_WITH_AES_256_CCM_8 uint16 = 0xC0A3
http2cipher_TLS_PSK_WITH_AES_128_CCM uint16 = 0xC0A4
http2cipher_TLS_PSK_WITH_AES_256_CCM uint16 = 0xC0A5
http2cipher_TLS_DHE_PSK_WITH_AES_128_CCM uint16 = 0xC0A6
http2cipher_TLS_DHE_PSK_WITH_AES_256_CCM uint16 = 0xC0A7
http2cipher_TLS_PSK_WITH_AES_128_CCM_8 uint16 = 0xC0A8
http2cipher_TLS_PSK_WITH_AES_256_CCM_8 uint16 = 0xC0A9
http2cipher_TLS_PSK_DHE_WITH_AES_128_CCM_8 uint16 = 0xC0AA
http2cipher_TLS_PSK_DHE_WITH_AES_256_CCM_8 uint16 = 0xC0AB
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CCM uint16 = 0xC0AC
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CCM uint16 = 0xC0AD
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 uint16 = 0xC0AE
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 uint16 = 0xC0AF
// Unassigned uint16 = 0xC0B0-FF
// Unassigned uint16 = 0xC1-CB,*
// Unassigned uint16 = 0xCC00-A7
http2cipher_TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCA8
http2cipher_TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCA9
http2cipher_TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAA
http2cipher_TLS_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAB
http2cipher_TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAC
http2cipher_TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAD
http2cipher_TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256 uint16 = 0xCCAE
)
// isBadCipher reports whether the cipher is blacklisted by the HTTP/2 spec.
// References:
// https://tools.ietf.org/html/rfc7540#appendix-A
// Reject cipher suites from Appendix A.
// "This list includes those cipher suites that do not
// offer an ephemeral key exchange and those that are
// based on the TLS null, stream or block cipher type"
func http2isBadCipher(cipher uint16) bool {
switch cipher {
case http2cipher_TLS_NULL_WITH_NULL_NULL,
http2cipher_TLS_RSA_WITH_NULL_MD5,
http2cipher_TLS_RSA_WITH_NULL_SHA,
http2cipher_TLS_RSA_EXPORT_WITH_RC4_40_MD5,
http2cipher_TLS_RSA_WITH_RC4_128_MD5,
http2cipher_TLS_RSA_WITH_RC4_128_SHA,
http2cipher_TLS_RSA_EXPORT_WITH_RC2_CBC_40_MD5,
http2cipher_TLS_RSA_WITH_IDEA_CBC_SHA,
http2cipher_TLS_RSA_EXPORT_WITH_DES40_CBC_SHA,
http2cipher_TLS_RSA_WITH_DES_CBC_SHA,
http2cipher_TLS_RSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_DH_DSS_EXPORT_WITH_DES40_CBC_SHA,
http2cipher_TLS_DH_DSS_WITH_DES_CBC_SHA,
http2cipher_TLS_DH_DSS_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_DH_RSA_EXPORT_WITH_DES40_CBC_SHA,
http2cipher_TLS_DH_RSA_WITH_DES_CBC_SHA,
http2cipher_TLS_DH_RSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA,
http2cipher_TLS_DHE_DSS_WITH_DES_CBC_SHA,
http2cipher_TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_DES_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_DH_anon_EXPORT_WITH_RC4_40_MD5,
http2cipher_TLS_DH_anon_WITH_RC4_128_MD5,
http2cipher_TLS_DH_anon_EXPORT_WITH_DES40_CBC_SHA,
http2cipher_TLS_DH_anon_WITH_DES_CBC_SHA,
http2cipher_TLS_DH_anon_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_KRB5_WITH_DES_CBC_SHA,
http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_KRB5_WITH_RC4_128_SHA,
http2cipher_TLS_KRB5_WITH_IDEA_CBC_SHA,
http2cipher_TLS_KRB5_WITH_DES_CBC_MD5,
http2cipher_TLS_KRB5_WITH_3DES_EDE_CBC_MD5,
http2cipher_TLS_KRB5_WITH_RC4_128_MD5,
http2cipher_TLS_KRB5_WITH_IDEA_CBC_MD5,
http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_SHA,
http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_SHA,
http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_SHA,
http2cipher_TLS_KRB5_EXPORT_WITH_DES_CBC_40_MD5,
http2cipher_TLS_KRB5_EXPORT_WITH_RC2_CBC_40_MD5,
http2cipher_TLS_KRB5_EXPORT_WITH_RC4_40_MD5,
http2cipher_TLS_PSK_WITH_NULL_SHA,
http2cipher_TLS_DHE_PSK_WITH_NULL_SHA,
http2cipher_TLS_RSA_PSK_WITH_NULL_SHA,
http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA,
http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA,
http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA,
http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA,
http2cipher_TLS_RSA_WITH_NULL_SHA256,
http2cipher_TLS_RSA_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_RSA_WITH_AES_256_CBC_SHA256,
http2cipher_TLS_DH_DSS_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_DH_RSA_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_DHE_DSS_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA,
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA,
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA,
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA,
http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_DH_DSS_WITH_AES_256_CBC_SHA256,
http2cipher_TLS_DH_RSA_WITH_AES_256_CBC_SHA256,
http2cipher_TLS_DHE_DSS_WITH_AES_256_CBC_SHA256,
http2cipher_TLS_DHE_RSA_WITH_AES_256_CBC_SHA256,
http2cipher_TLS_DH_anon_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_DH_anon_WITH_AES_256_CBC_SHA256,
http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA,
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA,
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA,
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA,
http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA,
http2cipher_TLS_PSK_WITH_RC4_128_SHA,
http2cipher_TLS_PSK_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA,
http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA,
http2cipher_TLS_DHE_PSK_WITH_RC4_128_SHA,
http2cipher_TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA,
http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA,
http2cipher_TLS_RSA_PSK_WITH_RC4_128_SHA,
http2cipher_TLS_RSA_PSK_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA,
http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA,
http2cipher_TLS_RSA_WITH_SEED_CBC_SHA,
http2cipher_TLS_DH_DSS_WITH_SEED_CBC_SHA,
http2cipher_TLS_DH_RSA_WITH_SEED_CBC_SHA,
http2cipher_TLS_DHE_DSS_WITH_SEED_CBC_SHA,
http2cipher_TLS_DHE_RSA_WITH_SEED_CBC_SHA,
http2cipher_TLS_DH_anon_WITH_SEED_CBC_SHA,
http2cipher_TLS_RSA_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_RSA_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_DH_RSA_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_DH_RSA_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_DH_DSS_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_DH_DSS_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_DH_anon_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_DH_anon_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_PSK_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_PSK_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_RSA_PSK_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_RSA_PSK_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_PSK_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_PSK_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_PSK_WITH_NULL_SHA256,
http2cipher_TLS_PSK_WITH_NULL_SHA384,
http2cipher_TLS_DHE_PSK_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_DHE_PSK_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_DHE_PSK_WITH_NULL_SHA256,
http2cipher_TLS_DHE_PSK_WITH_NULL_SHA384,
http2cipher_TLS_RSA_PSK_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_RSA_PSK_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_RSA_PSK_WITH_NULL_SHA256,
http2cipher_TLS_RSA_PSK_WITH_NULL_SHA384,
http2cipher_TLS_RSA_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_RSA_WITH_CAMELLIA_256_CBC_SHA256,
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_CBC_SHA256,
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_CBC_SHA256,
http2cipher_TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA256,
http2cipher_TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256,
http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_CBC_SHA256,
http2cipher_TLS_EMPTY_RENEGOTIATION_INFO_SCSV,
http2cipher_TLS_ECDH_ECDSA_WITH_NULL_SHA,
http2cipher_TLS_ECDH_ECDSA_WITH_RC4_128_SHA,
http2cipher_TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_ECDHE_ECDSA_WITH_NULL_SHA,
http2cipher_TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
http2cipher_TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_ECDH_RSA_WITH_NULL_SHA,
http2cipher_TLS_ECDH_RSA_WITH_RC4_128_SHA,
http2cipher_TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_ECDHE_RSA_WITH_NULL_SHA,
http2cipher_TLS_ECDHE_RSA_WITH_RC4_128_SHA,
http2cipher_TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_ECDH_anon_WITH_NULL_SHA,
http2cipher_TLS_ECDH_anon_WITH_RC4_128_SHA,
http2cipher_TLS_ECDH_anon_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_ECDH_anon_WITH_AES_128_CBC_SHA,
http2cipher_TLS_ECDH_anon_WITH_AES_256_CBC_SHA,
http2cipher_TLS_SRP_SHA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_SRP_SHA_RSA_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_SRP_SHA_DSS_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_SRP_SHA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_SRP_SHA_RSA_WITH_AES_128_CBC_SHA,
http2cipher_TLS_SRP_SHA_DSS_WITH_AES_128_CBC_SHA,
http2cipher_TLS_SRP_SHA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_SRP_SHA_RSA_WITH_AES_256_CBC_SHA,
http2cipher_TLS_SRP_SHA_DSS_WITH_AES_256_CBC_SHA,
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_ECDH_ECDSA_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256,
http2cipher_TLS_ECDH_RSA_WITH_AES_256_GCM_SHA384,
http2cipher_TLS_ECDHE_PSK_WITH_RC4_128_SHA,
http2cipher_TLS_ECDHE_PSK_WITH_3DES_EDE_CBC_SHA,
http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA,
http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA,
http2cipher_TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA256,
http2cipher_TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA384,
http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA,
http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA256,
http2cipher_TLS_ECDHE_PSK_WITH_NULL_SHA384,
http2cipher_TLS_RSA_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_RSA_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_DH_DSS_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_DH_DSS_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_DH_RSA_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_DH_RSA_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_DHE_DSS_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_DHE_DSS_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_DHE_RSA_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_DHE_RSA_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_DH_anon_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_DH_anon_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_ECDHE_ECDSA_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_ECDHE_RSA_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_ECDHE_RSA_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_RSA_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_RSA_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_DH_RSA_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_DH_RSA_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_DH_DSS_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_DH_DSS_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_DH_anon_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_DH_anon_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_ECDH_ECDSA_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_ECDH_RSA_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_ECDH_RSA_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_PSK_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_PSK_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_DHE_PSK_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_DHE_PSK_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_RSA_PSK_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_RSA_PSK_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_PSK_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_PSK_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_RSA_PSK_WITH_ARIA_128_GCM_SHA256,
http2cipher_TLS_RSA_PSK_WITH_ARIA_256_GCM_SHA384,
http2cipher_TLS_ECDHE_PSK_WITH_ARIA_128_CBC_SHA256,
http2cipher_TLS_ECDHE_PSK_WITH_ARIA_256_CBC_SHA384,
http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_ECDHE_ECDSA_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_ECDHE_RSA_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_RSA_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_RSA_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_DH_RSA_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_DH_DSS_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_DH_anon_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_DH_anon_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_ECDH_ECDSA_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_ECDH_RSA_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_PSK_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_PSK_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_GCM_SHA256,
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_GCM_SHA384,
http2cipher_TLS_PSK_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_PSK_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_DHE_PSK_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_RSA_PSK_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_128_CBC_SHA256,
http2cipher_TLS_ECDHE_PSK_WITH_CAMELLIA_256_CBC_SHA384,
http2cipher_TLS_RSA_WITH_AES_128_CCM,
http2cipher_TLS_RSA_WITH_AES_256_CCM,
http2cipher_TLS_RSA_WITH_AES_128_CCM_8,
http2cipher_TLS_RSA_WITH_AES_256_CCM_8,
http2cipher_TLS_PSK_WITH_AES_128_CCM,
http2cipher_TLS_PSK_WITH_AES_256_CCM,
http2cipher_TLS_PSK_WITH_AES_128_CCM_8,
http2cipher_TLS_PSK_WITH_AES_256_CCM_8:
return true
default:
return false
}
}
// ClientConnPool manages a pool of HTTP/2 client connections.
type http2ClientConnPool interface {
GetClientConn(req *Request, addr string) (*http2ClientConn, error)
MarkDead(*http2ClientConn)
}
// clientConnPoolIdleCloser is the interface implemented by ClientConnPool
// implementations which can close their idle connections.
type http2clientConnPoolIdleCloser interface {
http2ClientConnPool
closeIdleConnections()
}
var (
_ http2clientConnPoolIdleCloser = (*http2clientConnPool)(nil)
_ http2clientConnPoolIdleCloser = http2noDialClientConnPool{}
)
// TODO: use singleflight for dialing and addConnCalls?
type http2clientConnPool struct {
t *http2Transport
mu sync.Mutex // TODO: maybe switch to RWMutex
// TODO: add support for sharing conns based on cert names
// (e.g. share conn for googleapis.com and appspot.com)
conns map[string][]*http2ClientConn // key is host:port
dialing map[string]*http2dialCall // currently in-flight dials
keys map[*http2ClientConn][]string
addConnCalls map[string]*http2addConnCall // in-flight addConnIfNeede calls
}
func (p *http2clientConnPool) GetClientConn(req *Request, addr string) (*http2ClientConn, error) {
return p.getClientConn(req, addr, http2dialOnMiss)
}
const (
http2dialOnMiss = true
http2noDialOnMiss = false
)
// shouldTraceGetConn reports whether getClientConn should call any
// ClientTrace.GetConn hook associated with the http.Request.
//
// This complexity is needed to avoid double calls of the GetConn hook
// during the back-and-forth between net/http and x/net/http2 (when the
// net/http.Transport is upgraded to also speak http2), as well as support
// the case where x/net/http2 is being used directly.
func (p *http2clientConnPool) shouldTraceGetConn(st http2clientConnIdleState) bool {
// If our Transport wasn't made via ConfigureTransport, always
// trace the GetConn hook if provided, because that means the
// http2 package is being used directly and it's the one
// dialing, as opposed to net/http.
if _, ok := p.t.ConnPool.(http2noDialClientConnPool); !ok {
return true
}
// Otherwise, only use the GetConn hook if this connection has
// been used previously for other requests. For fresh
// connections, the net/http package does the dialing.
return !st.freshConn
}
func (p *http2clientConnPool) getClientConn(req *Request, addr string, dialOnMiss bool) (*http2ClientConn, error) {
if http2isConnectionCloseRequest(req) && dialOnMiss {
// It gets its own connection.
http2traceGetConn(req, addr)
const singleUse = true
cc, err := p.t.dialClientConn(addr, singleUse)
if err != nil {
return nil, err
}
return cc, nil
}
p.mu.Lock()
for _, cc := range p.conns[addr] {
if st := cc.idleState(); st.canTakeNewRequest {
if p.shouldTraceGetConn(st) {
http2traceGetConn(req, addr)
}
p.mu.Unlock()
return cc, nil
}
}
if !dialOnMiss {
p.mu.Unlock()
return nil, http2ErrNoCachedConn
}
http2traceGetConn(req, addr)
call := p.getStartDialLocked(addr)
p.mu.Unlock()
<-call.done
return call.res, call.err
}
// dialCall is an in-flight Transport dial call to a host.
type http2dialCall struct {
p *http2clientConnPool
done chan struct{} // closed when done
res *http2ClientConn // valid after done is closed
err error // valid after done is closed
}
// requires p.mu is held.
func (p *http2clientConnPool) getStartDialLocked(addr string) *http2dialCall {
if call, ok := p.dialing[addr]; ok {
// A dial is already in-flight. Don't start another.
return call
}
call := &http2dialCall{p: p, done: make(chan struct{})}
if p.dialing == nil {
p.dialing = make(map[string]*http2dialCall)
}
p.dialing[addr] = call
go call.dial(addr)
return call
}
// run in its own goroutine.
func (c *http2dialCall) dial(addr string) {
const singleUse = false // shared conn
c.res, c.err = c.p.t.dialClientConn(addr, singleUse)
close(c.done)
c.p.mu.Lock()
delete(c.p.dialing, addr)
if c.err == nil {
c.p.addConnLocked(addr, c.res)
}
c.p.mu.Unlock()
}
// addConnIfNeeded makes a NewClientConn out of c if a connection for key doesn't
// already exist. It coalesces concurrent calls with the same key.
// This is used by the http1 Transport code when it creates a new connection. Because
// the http1 Transport doesn't de-dup TCP dials to outbound hosts (because it doesn't know
// the protocol), it can get into a situation where it has multiple TLS connections.
// This code decides which ones live or die.
// The return value used is whether c was used.
// c is never closed.
func (p *http2clientConnPool) addConnIfNeeded(key string, t *http2Transport, c *tls.Conn) (used bool, err error) {
p.mu.Lock()
for _, cc := range p.conns[key] {
if cc.CanTakeNewRequest() {
p.mu.Unlock()
return false, nil
}
}
call, dup := p.addConnCalls[key]
if !dup {
if p.addConnCalls == nil {
p.addConnCalls = make(map[string]*http2addConnCall)
}
call = &http2addConnCall{
p: p,
done: make(chan struct{}),
}
p.addConnCalls[key] = call
go call.run(t, key, c)
}
p.mu.Unlock()
<-call.done
if call.err != nil {
return false, call.err
}
return !dup, nil
}
type http2addConnCall struct {
p *http2clientConnPool
done chan struct{} // closed when done
err error
}
func (c *http2addConnCall) run(t *http2Transport, key string, tc *tls.Conn) {
cc, err := t.NewClientConn(tc)
p := c.p
p.mu.Lock()
if err != nil {
c.err = err
} else {
p.addConnLocked(key, cc)
}
delete(p.addConnCalls, key)
p.mu.Unlock()
close(c.done)
}
func (p *http2clientConnPool) addConn(key string, cc *http2ClientConn) {
p.mu.Lock()
p.addConnLocked(key, cc)
p.mu.Unlock()
}
// p.mu must be held
func (p *http2clientConnPool) addConnLocked(key string, cc *http2ClientConn) {
for _, v := range p.conns[key] {
if v == cc {
return
}
}
if p.conns == nil {
p.conns = make(map[string][]*http2ClientConn)
}
if p.keys == nil {
p.keys = make(map[*http2ClientConn][]string)
}
p.conns[key] = append(p.conns[key], cc)
p.keys[cc] = append(p.keys[cc], key)
}
func (p *http2clientConnPool) MarkDead(cc *http2ClientConn) {
p.mu.Lock()
defer p.mu.Unlock()
for _, key := range p.keys[cc] {
vv, ok := p.conns[key]
if !ok {
continue
}
newList := http2filterOutClientConn(vv, cc)
if len(newList) > 0 {
p.conns[key] = newList
} else {
delete(p.conns, key)
}
}
delete(p.keys, cc)
}
func (p *http2clientConnPool) closeIdleConnections() {
p.mu.Lock()
defer p.mu.Unlock()
// TODO: don't close a cc if it was just added to the pool
// milliseconds ago and has never been used. There's currently
// a small race window with the HTTP/1 Transport's integration
// where it can add an idle conn just before using it, and
// somebody else can concurrently call CloseIdleConns and
// break some caller's RoundTrip.
for _, vv := range p.conns {
for _, cc := range vv {
cc.closeIfIdle()
}
}
}
func http2filterOutClientConn(in []*http2ClientConn, exclude *http2ClientConn) []*http2ClientConn {
out := in[:0]
for _, v := range in {
if v != exclude {
out = append(out, v)
}
}
// If we filtered it out, zero out the last item to prevent
// the GC from seeing it.
if len(in) != len(out) {
in[len(in)-1] = nil
}
return out
}
// noDialClientConnPool is an implementation of http2.ClientConnPool
// which never dials. We let the HTTP/1.1 client dial and use its TLS
// connection instead.
type http2noDialClientConnPool struct{ *http2clientConnPool }
func (p http2noDialClientConnPool) GetClientConn(req *Request, addr string) (*http2ClientConn, error) {
return p.getClientConn(req, addr, http2noDialOnMiss)
}
// Buffer chunks are allocated from a pool to reduce pressure on GC.
// The maximum wasted space per dataBuffer is 2x the largest size class,
// which happens when the dataBuffer has multiple chunks and there is
// one unread byte in both the first and last chunks. We use a few size
// classes to minimize overheads for servers that typically receive very
// small request bodies.
//
// TODO: Benchmark to determine if the pools are necessary. The GC may have
// improved enough that we can instead allocate chunks like this:
// make([]byte, max(16<<10, expectedBytesRemaining))
var (
http2dataChunkSizeClasses = []int{
1 << 10,
2 << 10,
4 << 10,
8 << 10,
16 << 10,
}
http2dataChunkPools = [...]sync.Pool{
{New: func() interface{} { return make([]byte, 1<<10) }},
{New: func() interface{} { return make([]byte, 2<<10) }},
{New: func() interface{} { return make([]byte, 4<<10) }},
{New: func() interface{} { return make([]byte, 8<<10) }},
{New: func() interface{} { return make([]byte, 16<<10) }},
}
)
func http2getDataBufferChunk(size int64) []byte {
i := 0
for ; i < len(http2dataChunkSizeClasses)-1; i++ {
if size <= int64(http2dataChunkSizeClasses[i]) {
break
}
}
return http2dataChunkPools[i].Get().([]byte)
}
func http2putDataBufferChunk(p []byte) {
for i, n := range http2dataChunkSizeClasses {
if len(p) == n {
http2dataChunkPools[i].Put(p)
return
}
}
panic(fmt.Sprintf("unexpected buffer len=%v", len(p)))
}
// dataBuffer is an io.ReadWriter backed by a list of data chunks.
// Each dataBuffer is used to read DATA frames on a single stream.
// The buffer is divided into chunks so the server can limit the
// total memory used by a single connection without limiting the
// request body size on any single stream.
type http2dataBuffer struct {
chunks [][]byte
r int // next byte to read is chunks[0][r]
w int // next byte to write is chunks[len(chunks)-1][w]
size int // total buffered bytes
expected int64 // we expect at least this many bytes in future Write calls (ignored if <= 0)
}
var http2errReadEmpty = errors.New("read from empty dataBuffer")
// Read copies bytes from the buffer into p.
// It is an error to read when no data is available.
func (b *http2dataBuffer) Read(p []byte) (int, error) {
if b.size == 0 {
return 0, http2errReadEmpty
}
var ntotal int
for len(p) > 0 && b.size > 0 {
readFrom := b.bytesFromFirstChunk()
n := copy(p, readFrom)
p = p[n:]
ntotal += n
b.r += n
b.size -= n
// If the first chunk has been consumed, advance to the next chunk.
if b.r == len(b.chunks[0]) {
http2putDataBufferChunk(b.chunks[0])
end := len(b.chunks) - 1
copy(b.chunks[:end], b.chunks[1:])
b.chunks[end] = nil
b.chunks = b.chunks[:end]
b.r = 0
}
}
return ntotal, nil
}
func (b *http2dataBuffer) bytesFromFirstChunk() []byte {
if len(b.chunks) == 1 {
return b.chunks[0][b.r:b.w]
}
return b.chunks[0][b.r:]
}
// Len returns the number of bytes of the unread portion of the buffer.
func (b *http2dataBuffer) Len() int {
return b.size
}
// Write appends p to the buffer.
func (b *http2dataBuffer) Write(p []byte) (int, error) {
ntotal := len(p)
for len(p) > 0 {
// If the last chunk is empty, allocate a new chunk. Try to allocate
// enough to fully copy p plus any additional bytes we expect to
// receive. However, this may allocate less than len(p).
want := int64(len(p))
if b.expected > want {
want = b.expected
}
chunk := b.lastChunkOrAlloc(want)
n := copy(chunk[b.w:], p)
p = p[n:]
b.w += n
b.size += n
b.expected -= int64(n)
}
return ntotal, nil
}
func (b *http2dataBuffer) lastChunkOrAlloc(want int64) []byte {
if len(b.chunks) != 0 {
last := b.chunks[len(b.chunks)-1]
if b.w < len(last) {
return last
}
}
chunk := http2getDataBufferChunk(want)
b.chunks = append(b.chunks, chunk)
b.w = 0
return chunk
}
// An ErrCode is an unsigned 32-bit error code as defined in the HTTP/2 spec.
type http2ErrCode uint32
const (
http2ErrCodeNo http2ErrCode = 0x0
http2ErrCodeProtocol http2ErrCode = 0x1
http2ErrCodeInternal http2ErrCode = 0x2
http2ErrCodeFlowControl http2ErrCode = 0x3
http2ErrCodeSettingsTimeout http2ErrCode = 0x4
http2ErrCodeStreamClosed http2ErrCode = 0x5
http2ErrCodeFrameSize http2ErrCode = 0x6
http2ErrCodeRefusedStream http2ErrCode = 0x7
http2ErrCodeCancel http2ErrCode = 0x8
http2ErrCodeCompression http2ErrCode = 0x9
http2ErrCodeConnect http2ErrCode = 0xa
http2ErrCodeEnhanceYourCalm http2ErrCode = 0xb
http2ErrCodeInadequateSecurity http2ErrCode = 0xc
http2ErrCodeHTTP11Required http2ErrCode = 0xd
)
var http2errCodeName = map[http2ErrCode]string{
http2ErrCodeNo: "NO_ERROR",
http2ErrCodeProtocol: "PROTOCOL_ERROR",
http2ErrCodeInternal: "INTERNAL_ERROR",
http2ErrCodeFlowControl: "FLOW_CONTROL_ERROR",
http2ErrCodeSettingsTimeout: "SETTINGS_TIMEOUT",
http2ErrCodeStreamClosed: "STREAM_CLOSED",
http2ErrCodeFrameSize: "FRAME_SIZE_ERROR",
http2ErrCodeRefusedStream: "REFUSED_STREAM",
http2ErrCodeCancel: "CANCEL",
http2ErrCodeCompression: "COMPRESSION_ERROR",
http2ErrCodeConnect: "CONNECT_ERROR",
http2ErrCodeEnhanceYourCalm: "ENHANCE_YOUR_CALM",
http2ErrCodeInadequateSecurity: "INADEQUATE_SECURITY",
http2ErrCodeHTTP11Required: "HTTP_1_1_REQUIRED",
}
func (e http2ErrCode) String() string {
if s, ok := http2errCodeName[e]; ok {
return s
}
return fmt.Sprintf("unknown error code 0x%x", uint32(e))
}
// ConnectionError is an error that results in the termination of the
// entire connection.
type http2ConnectionError http2ErrCode
func (e http2ConnectionError) Error() string {
return fmt.Sprintf("connection error: %s", http2ErrCode(e))
}
// StreamError is an error that only affects one stream within an
// HTTP/2 connection.
type http2StreamError struct {
StreamID uint32
Code http2ErrCode
Cause error // optional additional detail
}
func http2streamError(id uint32, code http2ErrCode) http2StreamError {
return http2StreamError{StreamID: id, Code: code}
}
func (e http2StreamError) Error() string {
if e.Cause != nil {
return fmt.Sprintf("stream error: stream ID %d; %v; %v", e.StreamID, e.Code, e.Cause)
}
return fmt.Sprintf("stream error: stream ID %d; %v", e.StreamID, e.Code)
}
// 6.9.1 The Flow Control Window
// "If a sender receives a WINDOW_UPDATE that causes a flow control
// window to exceed this maximum it MUST terminate either the stream
// or the connection, as appropriate. For streams, [...]; for the
// connection, a GOAWAY frame with a FLOW_CONTROL_ERROR code."
type http2goAwayFlowError struct{}
func (http2goAwayFlowError) Error() string { return "connection exceeded flow control window size" }
// connError represents an HTTP/2 ConnectionError error code, along
// with a string (for debugging) explaining why.
//
// Errors of this type are only returned by the frame parser functions
// and converted into ConnectionError(Code), after stashing away
// the Reason into the Framer's errDetail field, accessible via
// the (*Framer).ErrorDetail method.
type http2connError struct {
Code http2ErrCode // the ConnectionError error code
Reason string // additional reason
}
func (e http2connError) Error() string {
return fmt.Sprintf("http2: connection error: %v: %v", e.Code, e.Reason)
}
type http2pseudoHeaderError string
func (e http2pseudoHeaderError) Error() string {
return fmt.Sprintf("invalid pseudo-header %q", string(e))
}
type http2duplicatePseudoHeaderError string
func (e http2duplicatePseudoHeaderError) Error() string {
return fmt.Sprintf("duplicate pseudo-header %q", string(e))
}
type http2headerFieldNameError string
func (e http2headerFieldNameError) Error() string {
return fmt.Sprintf("invalid header field name %q", string(e))
}
type http2headerFieldValueError string
func (e http2headerFieldValueError) Error() string {
return fmt.Sprintf("invalid header field value %q", string(e))
}
var (
http2errMixPseudoHeaderTypes = errors.New("mix of request and response pseudo headers")
http2errPseudoAfterRegular = errors.New("pseudo header field after regular")
)
// flow is the flow control window's size.
type http2flow struct {
// n is the number of DATA bytes we're allowed to send.
// A flow is kept both on a conn and a per-stream.
n int32
// conn points to the shared connection-level flow that is
// shared by all streams on that conn. It is nil for the flow
// that's on the conn directly.
conn *http2flow
}
func (f *http2flow) setConnFlow(cf *http2flow) { f.conn = cf }
func (f *http2flow) available() int32 {
n := f.n
if f.conn != nil && f.conn.n < n {
n = f.conn.n
}
return n
}
func (f *http2flow) take(n int32) {
if n > f.available() {
panic("internal error: took too much")
}
f.n -= n
if f.conn != nil {
f.conn.n -= n
}
}
// add adds n bytes (positive or negative) to the flow control window.
// It returns false if the sum would exceed 2^31-1.
func (f *http2flow) add(n int32) bool {
sum := f.n + n
if (sum > n) == (f.n > 0) {
f.n = sum
return true
}
return false
}
const http2frameHeaderLen = 9
var http2padZeros = make([]byte, 255) // zeros for padding
// A FrameType is a registered frame type as defined in
// http://http2.github.io/http2-spec/#rfc.section.11.2
type http2FrameType uint8
const (
http2FrameData http2FrameType = 0x0
http2FrameHeaders http2FrameType = 0x1
http2FramePriority http2FrameType = 0x2
http2FrameRSTStream http2FrameType = 0x3
http2FrameSettings http2FrameType = 0x4
http2FramePushPromise http2FrameType = 0x5
http2FramePing http2FrameType = 0x6
http2FrameGoAway http2FrameType = 0x7
http2FrameWindowUpdate http2FrameType = 0x8
http2FrameContinuation http2FrameType = 0x9
)
var http2frameName = map[http2FrameType]string{
http2FrameData: "DATA",
http2FrameHeaders: "HEADERS",
http2FramePriority: "PRIORITY",
http2FrameRSTStream: "RST_STREAM",
http2FrameSettings: "SETTINGS",
http2FramePushPromise: "PUSH_PROMISE",
http2FramePing: "PING",
http2FrameGoAway: "GOAWAY",
http2FrameWindowUpdate: "WINDOW_UPDATE",
http2FrameContinuation: "CONTINUATION",
}
func (t http2FrameType) String() string {
if s, ok := http2frameName[t]; ok {
return s
}
return fmt.Sprintf("UNKNOWN_FRAME_TYPE_%d", uint8(t))
}
// Flags is a bitmask of HTTP/2 flags.
// The meaning of flags varies depending on the frame type.
type http2Flags uint8
// Has reports whether f contains all (0 or more) flags in v.
func (f http2Flags) Has(v http2Flags) bool {
return (f & v) == v
}
// Frame-specific FrameHeader flag bits.
const (
// Data Frame
http2FlagDataEndStream http2Flags = 0x1
http2FlagDataPadded http2Flags = 0x8
// Headers Frame
http2FlagHeadersEndStream http2Flags = 0x1
http2FlagHeadersEndHeaders http2Flags = 0x4
http2FlagHeadersPadded http2Flags = 0x8
http2FlagHeadersPriority http2Flags = 0x20
// Settings Frame
http2FlagSettingsAck http2Flags = 0x1
// Ping Frame
http2FlagPingAck http2Flags = 0x1
// Continuation Frame
http2FlagContinuationEndHeaders http2Flags = 0x4
http2FlagPushPromiseEndHeaders http2Flags = 0x4
http2FlagPushPromisePadded http2Flags = 0x8
)
var http2flagName = map[http2FrameType]map[http2Flags]string{
http2FrameData: {
http2FlagDataEndStream: "END_STREAM",
http2FlagDataPadded: "PADDED",
},
http2FrameHeaders: {
http2FlagHeadersEndStream: "END_STREAM",
http2FlagHeadersEndHeaders: "END_HEADERS",
http2FlagHeadersPadded: "PADDED",
http2FlagHeadersPriority: "PRIORITY",
},
http2FrameSettings: {
http2FlagSettingsAck: "ACK",
},
http2FramePing: {
http2FlagPingAck: "ACK",
},
http2FrameContinuation: {
http2FlagContinuationEndHeaders: "END_HEADERS",
},
http2FramePushPromise: {
http2FlagPushPromiseEndHeaders: "END_HEADERS",
http2FlagPushPromisePadded: "PADDED",
},
}
// a frameParser parses a frame given its FrameHeader and payload
// bytes. The length of payload will always equal fh.Length (which
// might be 0).
type http2frameParser func(fc *http2frameCache, fh http2FrameHeader, payload []byte) (http2Frame, error)
var http2frameParsers = map[http2FrameType]http2frameParser{
http2FrameData: http2parseDataFrame,
http2FrameHeaders: http2parseHeadersFrame,
http2FramePriority: http2parsePriorityFrame,
http2FrameRSTStream: http2parseRSTStreamFrame,
http2FrameSettings: http2parseSettingsFrame,
http2FramePushPromise: http2parsePushPromise,
http2FramePing: http2parsePingFrame,
http2FrameGoAway: http2parseGoAwayFrame,
http2FrameWindowUpdate: http2parseWindowUpdateFrame,
http2FrameContinuation: http2parseContinuationFrame,
}
func http2typeFrameParser(t http2FrameType) http2frameParser {
if f := http2frameParsers[t]; f != nil {
return f
}
return http2parseUnknownFrame
}
// A FrameHeader is the 9 byte header of all HTTP/2 frames.
//
// See http://http2.github.io/http2-spec/#FrameHeader
type http2FrameHeader struct {
valid bool // caller can access []byte fields in the Frame
// Type is the 1 byte frame type. There are ten standard frame
// types, but extension frame types may be written by WriteRawFrame
// and will be returned by ReadFrame (as UnknownFrame).
Type http2FrameType
// Flags are the 1 byte of 8 potential bit flags per frame.
// They are specific to the frame type.
Flags http2Flags
// Length is the length of the frame, not including the 9 byte header.
// The maximum size is one byte less than 16MB (uint24), but only
// frames up to 16KB are allowed without peer agreement.
Length uint32
// StreamID is which stream this frame is for. Certain frames
// are not stream-specific, in which case this field is 0.
StreamID uint32
}
// Header returns h. It exists so FrameHeaders can be embedded in other
// specific frame types and implement the Frame interface.
func (h http2FrameHeader) Header() http2FrameHeader { return h }
func (h http2FrameHeader) String() string {
var buf bytes.Buffer
buf.WriteString("[FrameHeader ")
h.writeDebug(&buf)
buf.WriteByte(']')
return buf.String()
}
func (h http2FrameHeader) writeDebug(buf *bytes.Buffer) {
buf.WriteString(h.Type.String())
if h.Flags != 0 {
buf.WriteString(" flags=")
set := 0
for i := uint8(0); i < 8; i++ {
if h.Flags&(1<<i) == 0 {
continue
}
set++
if set > 1 {
buf.WriteByte('|')
}
name := http2flagName[h.Type][http2Flags(1<<i)]
if name != "" {
buf.WriteString(name)
} else {
fmt.Fprintf(buf, "0x%x", 1<<i)
}
}
}
if h.StreamID != 0 {
fmt.Fprintf(buf, " stream=%d", h.StreamID)
}
fmt.Fprintf(buf, " len=%d", h.Length)
}
func (h *http2FrameHeader) checkValid() {
if !h.valid {
panic("Frame accessor called on non-owned Frame")
}
}
func (h *http2FrameHeader) invalidate() { h.valid = false }
// frame header bytes.
// Used only by ReadFrameHeader.
var http2fhBytes = sync.Pool{
New: func() interface{} {
buf := make([]byte, http2frameHeaderLen)
return &buf
},
}
// ReadFrameHeader reads 9 bytes from r and returns a FrameHeader.
// Most users should use Framer.ReadFrame instead.
func http2ReadFrameHeader(r io.Reader) (http2FrameHeader, error) {
bufp := http2fhBytes.Get().(*[]byte)
defer http2fhBytes.Put(bufp)
return http2readFrameHeader(*bufp, r)
}
func http2readFrameHeader(buf []byte, r io.Reader) (http2FrameHeader, error) {
_, err := io.ReadFull(r, buf[:http2frameHeaderLen])
if err != nil {
return http2FrameHeader{}, err
}
return http2FrameHeader{
Length: (uint32(buf[0])<<16 | uint32(buf[1])<<8 | uint32(buf[2])),
Type: http2FrameType(buf[3]),
Flags: http2Flags(buf[4]),
StreamID: binary.BigEndian.Uint32(buf[5:]) & (1<<31 - 1),
valid: true,
}, nil
}
// A Frame is the base interface implemented by all frame types.
// Callers will generally type-assert the specific frame type:
// *HeadersFrame, *SettingsFrame, *WindowUpdateFrame, etc.
//
// Frames are only valid until the next call to Framer.ReadFrame.
type http2Frame interface {
Header() http2FrameHeader
// invalidate is called by Framer.ReadFrame to make this
// frame's buffers as being invalid, since the subsequent
// frame will reuse them.
invalidate()
}
// A Framer reads and writes Frames.
type http2Framer struct {
r io.Reader
lastFrame http2Frame
errDetail error
// lastHeaderStream is non-zero if the last frame was an
// unfinished HEADERS/CONTINUATION.
lastHeaderStream uint32
maxReadSize uint32
headerBuf [http2frameHeaderLen]byte
// TODO: let getReadBuf be configurable, and use a less memory-pinning
// allocator in server.go to minimize memory pinned for many idle conns.
// Will probably also need to make frame invalidation have a hook too.
getReadBuf func(size uint32) []byte
readBuf []byte // cache for default getReadBuf
maxWriteSize uint32 // zero means unlimited; TODO: implement
w io.Writer
wbuf []byte
// AllowIllegalWrites permits the Framer's Write methods to
// write frames that do not conform to the HTTP/2 spec. This
// permits using the Framer to test other HTTP/2
// implementations' conformance to the spec.
// If false, the Write methods will prefer to return an error
// rather than comply.
AllowIllegalWrites bool
// AllowIllegalReads permits the Framer's ReadFrame method
// to return non-compliant frames or frame orders.
// This is for testing and permits using the Framer to test
// other HTTP/2 implementations' conformance to the spec.
// It is not compatible with ReadMetaHeaders.
AllowIllegalReads bool
// ReadMetaHeaders if non-nil causes ReadFrame to merge
// HEADERS and CONTINUATION frames together and return
// MetaHeadersFrame instead.
ReadMetaHeaders *hpack.Decoder
// MaxHeaderListSize is the http2 MAX_HEADER_LIST_SIZE.
// It's used only if ReadMetaHeaders is set; 0 means a sane default
// (currently 16MB)
// If the limit is hit, MetaHeadersFrame.Truncated is set true.
MaxHeaderListSize uint32
// TODO: track which type of frame & with which flags was sent
// last. Then return an error (unless AllowIllegalWrites) if
// we're in the middle of a header block and a
// non-Continuation or Continuation on a different stream is
// attempted to be written.
logReads, logWrites bool
debugFramer *http2Framer // only use for logging written writes
debugFramerBuf *bytes.Buffer
debugReadLoggerf func(string, ...interface{})
debugWriteLoggerf func(string, ...interface{})
frameCache *http2frameCache // nil if frames aren't reused (default)
}
func (fr *http2Framer) maxHeaderListSize() uint32 {
if fr.MaxHeaderListSize == 0 {
return 16 << 20 // sane default, per docs
}
return fr.MaxHeaderListSize
}
func (f *http2Framer) startWrite(ftype http2FrameType, flags http2Flags, streamID uint32) {
// Write the FrameHeader.
f.wbuf = append(f.wbuf[:0],
0, // 3 bytes of length, filled in in endWrite
0,
0,
byte(ftype),
byte(flags),
byte(streamID>>24),
byte(streamID>>16),
byte(streamID>>8),
byte(streamID))
}
func (f *http2Framer) endWrite() error {
// Now that we know the final size, fill in the FrameHeader in
// the space previously reserved for it. Abuse append.
length := len(f.wbuf) - http2frameHeaderLen
if length >= (1 << 24) {
return http2ErrFrameTooLarge
}
_ = append(f.wbuf[:0],
byte(length>>16),
byte(length>>8),
byte(length))
if f.logWrites {
f.logWrite()
}
n, err := f.w.Write(f.wbuf)
if err == nil && n != len(f.wbuf) {
err = io.ErrShortWrite
}
return err
}
func (f *http2Framer) logWrite() {
if f.debugFramer == nil {
f.debugFramerBuf = new(bytes.Buffer)
f.debugFramer = http2NewFramer(nil, f.debugFramerBuf)
f.debugFramer.logReads = false // we log it ourselves, saying "wrote" below
// Let us read anything, even if we accidentally wrote it
// in the wrong order:
f.debugFramer.AllowIllegalReads = true
}
f.debugFramerBuf.Write(f.wbuf)
fr, err := f.debugFramer.ReadFrame()
if err != nil {
f.debugWriteLoggerf("http2: Framer %p: failed to decode just-written frame", f)
return
}
f.debugWriteLoggerf("http2: Framer %p: wrote %v", f, http2summarizeFrame(fr))
}
func (f *http2Framer) writeByte(v byte) { f.wbuf = append(f.wbuf, v) }
func (f *http2Framer) writeBytes(v []byte) { f.wbuf = append(f.wbuf, v...) }
func (f *http2Framer) writeUint16(v uint16) { f.wbuf = append(f.wbuf, byte(v>>8), byte(v)) }
func (f *http2Framer) writeUint32(v uint32) {
f.wbuf = append(f.wbuf, byte(v>>24), byte(v>>16), byte(v>>8), byte(v))
}
const (
http2minMaxFrameSize = 1 << 14
http2maxFrameSize = 1<<24 - 1
)
// SetReuseFrames allows the Framer to reuse Frames.
// If called on a Framer, Frames returned by calls to ReadFrame are only
// valid until the next call to ReadFrame.
func (fr *http2Framer) SetReuseFrames() {
if fr.frameCache != nil {
return
}
fr.frameCache = &http2frameCache{}
}
type http2frameCache struct {
dataFrame http2DataFrame
}
func (fc *http2frameCache) getDataFrame() *http2DataFrame {
if fc == nil {
return &http2DataFrame{}
}
return &fc.dataFrame
}
// NewFramer returns a Framer that writes frames to w and reads them from r.
func http2NewFramer(w io.Writer, r io.Reader) *http2Framer {
fr := &http2Framer{
w: w,
r: r,
logReads: http2logFrameReads,
logWrites: http2logFrameWrites,
debugReadLoggerf: log.Printf,
debugWriteLoggerf: log.Printf,
}
fr.getReadBuf = func(size uint32) []byte {
if cap(fr.readBuf) >= int(size) {
return fr.readBuf[:size]
}
fr.readBuf = make([]byte, size)
return fr.readBuf
}
fr.SetMaxReadFrameSize(http2maxFrameSize)
return fr
}
// SetMaxReadFrameSize sets the maximum size of a frame
// that will be read by a subsequent call to ReadFrame.
// It is the caller's responsibility to advertise this
// limit with a SETTINGS frame.
func (fr *http2Framer) SetMaxReadFrameSize(v uint32) {
if v > http2maxFrameSize {
v = http2maxFrameSize
}
fr.maxReadSize = v
}
// ErrorDetail returns a more detailed error of the last error
// returned by Framer.ReadFrame. For instance, if ReadFrame
// returns a StreamError with code PROTOCOL_ERROR, ErrorDetail
// will say exactly what was invalid. ErrorDetail is not guaranteed
// to return a non-nil value and like the rest of the http2 package,
// its return value is not protected by an API compatibility promise.
// ErrorDetail is reset after the next call to ReadFrame.
func (fr *http2Framer) ErrorDetail() error {
return fr.errDetail
}
// ErrFrameTooLarge is returned from Framer.ReadFrame when the peer
// sends a frame that is larger than declared with SetMaxReadFrameSize.
var http2ErrFrameTooLarge = errors.New("http2: frame too large")
// terminalReadFrameError reports whether err is an unrecoverable
// error from ReadFrame and no other frames should be read.
func http2terminalReadFrameError(err error) bool {
if _, ok := err.(http2StreamError); ok {
return false
}
return err != nil
}
// ReadFrame reads a single frame. The returned Frame is only valid
// until the next call to ReadFrame.
//
// If the frame is larger than previously set with SetMaxReadFrameSize, the
// returned error is ErrFrameTooLarge. Other errors may be of type
// ConnectionError, StreamError, or anything else from the underlying
// reader.
func (fr *http2Framer) ReadFrame() (http2Frame, error) {
fr.errDetail = nil
if fr.lastFrame != nil {
fr.lastFrame.invalidate()
}
fh, err := http2readFrameHeader(fr.headerBuf[:], fr.r)
if err != nil {
return nil, err
}
if fh.Length > fr.maxReadSize {
return nil, http2ErrFrameTooLarge
}
payload := fr.getReadBuf(fh.Length)
if _, err := io.ReadFull(fr.r, payload); err != nil {
return nil, err
}
f, err := http2typeFrameParser(fh.Type)(fr.frameCache, fh, payload)
if err != nil {
if ce, ok := err.(http2connError); ok {
return nil, fr.connError(ce.Code, ce.Reason)
}
return nil, err
}
if err := fr.checkFrameOrder(f); err != nil {
return nil, err
}
if fr.logReads {
fr.debugReadLoggerf("http2: Framer %p: read %v", fr, http2summarizeFrame(f))
}
if fh.Type == http2FrameHeaders && fr.ReadMetaHeaders != nil {
return fr.readMetaFrame(f.(*http2HeadersFrame))
}
return f, nil
}
// connError returns ConnectionError(code) but first
// stashes away a public reason to the caller can optionally relay it
// to the peer before hanging up on them. This might help others debug
// their implementations.
func (fr *http2Framer) connError(code http2ErrCode, reason string) error {
fr.errDetail = errors.New(reason)
return http2ConnectionError(code)
}
// checkFrameOrder reports an error if f is an invalid frame to return
// next from ReadFrame. Mostly it checks whether HEADERS and
// CONTINUATION frames are contiguous.
func (fr *http2Framer) checkFrameOrder(f http2Frame) error {
last := fr.lastFrame
fr.lastFrame = f
if fr.AllowIllegalReads {
return nil
}
fh := f.Header()
if fr.lastHeaderStream != 0 {
if fh.Type != http2FrameContinuation {
return fr.connError(http2ErrCodeProtocol,
fmt.Sprintf("got %s for stream %d; expected CONTINUATION following %s for stream %d",
fh.Type, fh.StreamID,
last.Header().Type, fr.lastHeaderStream))
}
if fh.StreamID != fr.lastHeaderStream {
return fr.connError(http2ErrCodeProtocol,
fmt.Sprintf("got CONTINUATION for stream %d; expected stream %d",
fh.StreamID, fr.lastHeaderStream))
}
} else if fh.Type == http2FrameContinuation {
return fr.connError(http2ErrCodeProtocol, fmt.Sprintf("unexpected CONTINUATION for stream %d", fh.StreamID))
}
switch fh.Type {
case http2FrameHeaders, http2FrameContinuation:
if fh.Flags.Has(http2FlagHeadersEndHeaders) {
fr.lastHeaderStream = 0
} else {
fr.lastHeaderStream = fh.StreamID
}
}
return nil
}
// A DataFrame conveys arbitrary, variable-length sequences of octets
// associated with a stream.
// See http://http2.github.io/http2-spec/#rfc.section.6.1
type http2DataFrame struct {
http2FrameHeader
data []byte
}
func (f *http2DataFrame) StreamEnded() bool {
return f.http2FrameHeader.Flags.Has(http2FlagDataEndStream)
}
// Data returns the frame's data octets, not including any padding
// size byte or padding suffix bytes.
// The caller must not retain the returned memory past the next
// call to ReadFrame.
func (f *http2DataFrame) Data() []byte {
f.checkValid()
return f.data
}
func http2parseDataFrame(fc *http2frameCache, fh http2FrameHeader, payload []byte) (http2Frame, error) {
if fh.StreamID == 0 {
// DATA frames MUST be associated with a stream. If a
// DATA frame is received whose stream identifier
// field is 0x0, the recipient MUST respond with a
// connection error (Section 5.4.1) of type
// PROTOCOL_ERROR.
return nil, http2connError{http2ErrCodeProtocol, "DATA frame with stream ID 0"}
}
f := fc.getDataFrame()
f.http2FrameHeader = fh
var padSize byte
if fh.Flags.Has(http2FlagDataPadded) {
var err error
payload, padSize, err = http2readByte(payload)
if err != nil {
return nil, err
}
}
if int(padSize) > len(payload) {
// If the length of the padding is greater than the
// length of the frame payload, the recipient MUST
// treat this as a connection error.
// Filed: https://github.com/http2/http2-spec/issues/610
return nil, http2connError{http2ErrCodeProtocol, "pad size larger than data payload"}
}
f.data = payload[:len(payload)-int(padSize)]
return f, nil
}
var (
http2errStreamID = errors.New("invalid stream ID")
http2errDepStreamID = errors.New("invalid dependent stream ID")
http2errPadLength = errors.New("pad length too large")
http2errPadBytes = errors.New("padding bytes must all be zeros unless AllowIllegalWrites is enabled")
)
func http2validStreamIDOrZero(streamID uint32) bool {
return streamID&(1<<31) == 0
}
func http2validStreamID(streamID uint32) bool {
return streamID != 0 && streamID&(1<<31) == 0
}
// WriteData writes a DATA frame.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility not to violate the maximum frame size
// and to not call other Write methods concurrently.
func (f *http2Framer) WriteData(streamID uint32, endStream bool, data []byte) error {
return f.WriteDataPadded(streamID, endStream, data, nil)
}
// WriteData writes a DATA frame with optional padding.
//
// If pad is nil, the padding bit is not sent.
// The length of pad must not exceed 255 bytes.
// The bytes of pad must all be zero, unless f.AllowIllegalWrites is set.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility not to violate the maximum frame size
// and to not call other Write methods concurrently.
func (f *http2Framer) WriteDataPadded(streamID uint32, endStream bool, data, pad []byte) error {
if !http2validStreamID(streamID) && !f.AllowIllegalWrites {
return http2errStreamID
}
if len(pad) > 0 {
if len(pad) > 255 {
return http2errPadLength
}
if !f.AllowIllegalWrites {
for _, b := range pad {
if b != 0 {
// "Padding octets MUST be set to zero when sending."
return http2errPadBytes
}
}
}
}
var flags http2Flags
if endStream {
flags |= http2FlagDataEndStream
}
if pad != nil {
flags |= http2FlagDataPadded
}
f.startWrite(http2FrameData, flags, streamID)
if pad != nil {
f.wbuf = append(f.wbuf, byte(len(pad)))
}
f.wbuf = append(f.wbuf, data...)
f.wbuf = append(f.wbuf, pad...)
return f.endWrite()
}
// A SettingsFrame conveys configuration parameters that affect how
// endpoints communicate, such as preferences and constraints on peer
// behavior.
//
// See http://http2.github.io/http2-spec/#SETTINGS
type http2SettingsFrame struct {
http2FrameHeader
p []byte
}
func http2parseSettingsFrame(_ *http2frameCache, fh http2FrameHeader, p []byte) (http2Frame, error) {
if fh.Flags.Has(http2FlagSettingsAck) && fh.Length > 0 {
// When this (ACK 0x1) bit is set, the payload of the
// SETTINGS frame MUST be empty. Receipt of a
// SETTINGS frame with the ACK flag set and a length
// field value other than 0 MUST be treated as a
// connection error (Section 5.4.1) of type
// FRAME_SIZE_ERROR.
return nil, http2ConnectionError(http2ErrCodeFrameSize)
}
if fh.StreamID != 0 {
// SETTINGS frames always apply to a connection,
// never a single stream. The stream identifier for a
// SETTINGS frame MUST be zero (0x0). If an endpoint
// receives a SETTINGS frame whose stream identifier
// field is anything other than 0x0, the endpoint MUST
// respond with a connection error (Section 5.4.1) of
// type PROTOCOL_ERROR.
return nil, http2ConnectionError(http2ErrCodeProtocol)
}
if len(p)%6 != 0 {
// Expecting even number of 6 byte settings.
return nil, http2ConnectionError(http2ErrCodeFrameSize)
}
f := &http2SettingsFrame{http2FrameHeader: fh, p: p}
if v, ok := f.Value(http2SettingInitialWindowSize); ok && v > (1<<31)-1 {
// Values above the maximum flow control window size of 2^31 - 1 MUST
// be treated as a connection error (Section 5.4.1) of type
// FLOW_CONTROL_ERROR.
return nil, http2ConnectionError(http2ErrCodeFlowControl)
}
return f, nil
}
func (f *http2SettingsFrame) IsAck() bool {
return f.http2FrameHeader.Flags.Has(http2FlagSettingsAck)
}
func (f *http2SettingsFrame) Value(id http2SettingID) (v uint32, ok bool) {
f.checkValid()
for i := 0; i < f.NumSettings(); i++ {
if s := f.Setting(i); s.ID == id {
return s.Val, true
}
}
return 0, false
}
// Setting returns the setting from the frame at the given 0-based index.
// The index must be >= 0 and less than f.NumSettings().
func (f *http2SettingsFrame) Setting(i int) http2Setting {
buf := f.p
return http2Setting{
ID: http2SettingID(binary.BigEndian.Uint16(buf[i*6 : i*6+2])),
Val: binary.BigEndian.Uint32(buf[i*6+2 : i*6+6]),
}
}
func (f *http2SettingsFrame) NumSettings() int { return len(f.p) / 6 }
// HasDuplicates reports whether f contains any duplicate setting IDs.
func (f *http2SettingsFrame) HasDuplicates() bool {
num := f.NumSettings()
if num == 0 {
return false
}
// If it's small enough (the common case), just do the n^2
// thing and avoid a map allocation.
if num < 10 {
for i := 0; i < num; i++ {
idi := f.Setting(i).ID
for j := i + 1; j < num; j++ {
idj := f.Setting(j).ID
if idi == idj {
return true
}
}
}
return false
}
seen := map[http2SettingID]bool{}
for i := 0; i < num; i++ {
id := f.Setting(i).ID
if seen[id] {
return true
}
seen[id] = true
}
return false
}
// ForeachSetting runs fn for each setting.
// It stops and returns the first error.
func (f *http2SettingsFrame) ForeachSetting(fn func(http2Setting) error) error {
f.checkValid()
for i := 0; i < f.NumSettings(); i++ {
if err := fn(f.Setting(i)); err != nil {
return err
}
}
return nil
}
// WriteSettings writes a SETTINGS frame with zero or more settings
// specified and the ACK bit not set.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility to not call other Write methods concurrently.
func (f *http2Framer) WriteSettings(settings ...http2Setting) error {
f.startWrite(http2FrameSettings, 0, 0)
for _, s := range settings {
f.writeUint16(uint16(s.ID))
f.writeUint32(s.Val)
}
return f.endWrite()
}
// WriteSettingsAck writes an empty SETTINGS frame with the ACK bit set.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility to not call other Write methods concurrently.
func (f *http2Framer) WriteSettingsAck() error {
f.startWrite(http2FrameSettings, http2FlagSettingsAck, 0)
return f.endWrite()
}
// A PingFrame is a mechanism for measuring a minimal round trip time
// from the sender, as well as determining whether an idle connection
// is still functional.
// See http://http2.github.io/http2-spec/#rfc.section.6.7
type http2PingFrame struct {
http2FrameHeader
Data [8]byte
}
func (f *http2PingFrame) IsAck() bool { return f.Flags.Has(http2FlagPingAck) }
func http2parsePingFrame(_ *http2frameCache, fh http2FrameHeader, payload []byte) (http2Frame, error) {
if len(payload) != 8 {
return nil, http2ConnectionError(http2ErrCodeFrameSize)
}
if fh.StreamID != 0 {
return nil, http2ConnectionError(http2ErrCodeProtocol)
}
f := &http2PingFrame{http2FrameHeader: fh}
copy(f.Data[:], payload)
return f, nil
}
func (f *http2Framer) WritePing(ack bool, data [8]byte) error {
var flags http2Flags
if ack {
flags = http2FlagPingAck
}
f.startWrite(http2FramePing, flags, 0)
f.writeBytes(data[:])
return f.endWrite()
}
// A GoAwayFrame informs the remote peer to stop creating streams on this connection.
// See http://http2.github.io/http2-spec/#rfc.section.6.8
type http2GoAwayFrame struct {
http2FrameHeader
LastStreamID uint32
ErrCode http2ErrCode
debugData []byte
}
// DebugData returns any debug data in the GOAWAY frame. Its contents
// are not defined.
// The caller must not retain the returned memory past the next
// call to ReadFrame.
func (f *http2GoAwayFrame) DebugData() []byte {
f.checkValid()
return f.debugData
}
func http2parseGoAwayFrame(_ *http2frameCache, fh http2FrameHeader, p []byte) (http2Frame, error) {
if fh.StreamID != 0 {
return nil, http2ConnectionError(http2ErrCodeProtocol)
}
if len(p) < 8 {
return nil, http2ConnectionError(http2ErrCodeFrameSize)
}
return &http2GoAwayFrame{
http2FrameHeader: fh,
LastStreamID: binary.BigEndian.Uint32(p[:4]) & (1<<31 - 1),
ErrCode: http2ErrCode(binary.BigEndian.Uint32(p[4:8])),
debugData: p[8:],
}, nil
}
func (f *http2Framer) WriteGoAway(maxStreamID uint32, code http2ErrCode, debugData []byte) error {
f.startWrite(http2FrameGoAway, 0, 0)
f.writeUint32(maxStreamID & (1<<31 - 1))
f.writeUint32(uint32(code))
f.writeBytes(debugData)
return f.endWrite()
}
// An UnknownFrame is the frame type returned when the frame type is unknown
// or no specific frame type parser exists.
type http2UnknownFrame struct {
http2FrameHeader
p []byte
}
// Payload returns the frame's payload (after the header). It is not
// valid to call this method after a subsequent call to
// Framer.ReadFrame, nor is it valid to retain the returned slice.
// The memory is owned by the Framer and is invalidated when the next
// frame is read.
func (f *http2UnknownFrame) Payload() []byte {
f.checkValid()
return f.p
}
func http2parseUnknownFrame(_ *http2frameCache, fh http2FrameHeader, p []byte) (http2Frame, error) {
return &http2UnknownFrame{fh, p}, nil
}
// A WindowUpdateFrame is used to implement flow control.
// See http://http2.github.io/http2-spec/#rfc.section.6.9
type http2WindowUpdateFrame struct {
http2FrameHeader
Increment uint32 // never read with high bit set
}
func http2parseWindowUpdateFrame(_ *http2frameCache, fh http2FrameHeader, p []byte) (http2Frame, error) {
if len(p) != 4 {
return nil, http2ConnectionError(http2ErrCodeFrameSize)
}
inc := binary.BigEndian.Uint32(p[:4]) & 0x7fffffff // mask off high reserved bit
if inc == 0 {
// A receiver MUST treat the receipt of a
// WINDOW_UPDATE frame with an flow control window
// increment of 0 as a stream error (Section 5.4.2) of
// type PROTOCOL_ERROR; errors on the connection flow
// control window MUST be treated as a connection
// error (Section 5.4.1).
if fh.StreamID == 0 {
return nil, http2ConnectionError(http2ErrCodeProtocol)
}
return nil, http2streamError(fh.StreamID, http2ErrCodeProtocol)
}
return &http2WindowUpdateFrame{
http2FrameHeader: fh,
Increment: inc,
}, nil
}
// WriteWindowUpdate writes a WINDOW_UPDATE frame.
// The increment value must be between 1 and 2,147,483,647, inclusive.
// If the Stream ID is zero, the window update applies to the
// connection as a whole.
func (f *http2Framer) WriteWindowUpdate(streamID, incr uint32) error {
// "The legal range for the increment to the flow control window is 1 to 2^31-1 (2,147,483,647) octets."
if (incr < 1 || incr > 2147483647) && !f.AllowIllegalWrites {
return errors.New("illegal window increment value")
}
f.startWrite(http2FrameWindowUpdate, 0, streamID)
f.writeUint32(incr)
return f.endWrite()
}
// A HeadersFrame is used to open a stream and additionally carries a
// header block fragment.
type http2HeadersFrame struct {
http2FrameHeader
// Priority is set if FlagHeadersPriority is set in the FrameHeader.
Priority http2PriorityParam
headerFragBuf []byte // not owned
}
func (f *http2HeadersFrame) HeaderBlockFragment() []byte {
f.checkValid()
return f.headerFragBuf
}
func (f *http2HeadersFrame) HeadersEnded() bool {
return f.http2FrameHeader.Flags.Has(http2FlagHeadersEndHeaders)
}
func (f *http2HeadersFrame) StreamEnded() bool {
return f.http2FrameHeader.Flags.Has(http2FlagHeadersEndStream)
}
func (f *http2HeadersFrame) HasPriority() bool {
return f.http2FrameHeader.Flags.Has(http2FlagHeadersPriority)
}
func http2parseHeadersFrame(_ *http2frameCache, fh http2FrameHeader, p []byte) (_ http2Frame, err error) {
hf := &http2HeadersFrame{
http2FrameHeader: fh,
}
if fh.StreamID == 0 {
// HEADERS frames MUST be associated with a stream. If a HEADERS frame
// is received whose stream identifier field is 0x0, the recipient MUST
// respond with a connection error (Section 5.4.1) of type
// PROTOCOL_ERROR.
return nil, http2connError{http2ErrCodeProtocol, "HEADERS frame with stream ID 0"}
}
var padLength uint8
if fh.Flags.Has(http2FlagHeadersPadded) {
if p, padLength, err = http2readByte(p); err != nil {
return
}
}
if fh.Flags.Has(http2FlagHeadersPriority) {
var v uint32
p, v, err = http2readUint32(p)
if err != nil {
return nil, err
}
hf.Priority.StreamDep = v & 0x7fffffff
hf.Priority.Exclusive = (v != hf.Priority.StreamDep) // high bit was set
p, hf.Priority.Weight, err = http2readByte(p)
if err != nil {
return nil, err
}
}
if len(p)-int(padLength) <= 0 {
return nil, http2streamError(fh.StreamID, http2ErrCodeProtocol)
}
hf.headerFragBuf = p[:len(p)-int(padLength)]
return hf, nil
}
// HeadersFrameParam are the parameters for writing a HEADERS frame.
type http2HeadersFrameParam struct {
// StreamID is the required Stream ID to initiate.
StreamID uint32
// BlockFragment is part (or all) of a Header Block.
BlockFragment []byte
// EndStream indicates that the header block is the last that
// the endpoint will send for the identified stream. Setting
// this flag causes the stream to enter one of "half closed"
// states.
EndStream bool
// EndHeaders indicates that this frame contains an entire
// header block and is not followed by any
// CONTINUATION frames.
EndHeaders bool
// PadLength is the optional number of bytes of zeros to add
// to this frame.
PadLength uint8
// Priority, if non-zero, includes stream priority information
// in the HEADER frame.
Priority http2PriorityParam
}
// WriteHeaders writes a single HEADERS frame.
//
// This is a low-level header writing method. Encoding headers and
// splitting them into any necessary CONTINUATION frames is handled
// elsewhere.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility to not call other Write methods concurrently.
func (f *http2Framer) WriteHeaders(p http2HeadersFrameParam) error {
if !http2validStreamID(p.StreamID) && !f.AllowIllegalWrites {
return http2errStreamID
}
var flags http2Flags
if p.PadLength != 0 {
flags |= http2FlagHeadersPadded
}
if p.EndStream {
flags |= http2FlagHeadersEndStream
}
if p.EndHeaders {
flags |= http2FlagHeadersEndHeaders
}
if !p.Priority.IsZero() {
flags |= http2FlagHeadersPriority
}
f.startWrite(http2FrameHeaders, flags, p.StreamID)
if p.PadLength != 0 {
f.writeByte(p.PadLength)
}
if !p.Priority.IsZero() {
v := p.Priority.StreamDep
if !http2validStreamIDOrZero(v) && !f.AllowIllegalWrites {
return http2errDepStreamID
}
if p.Priority.Exclusive {
v |= 1 << 31
}
f.writeUint32(v)
f.writeByte(p.Priority.Weight)
}
f.wbuf = append(f.wbuf, p.BlockFragment...)
f.wbuf = append(f.wbuf, http2padZeros[:p.PadLength]...)
return f.endWrite()
}
// A PriorityFrame specifies the sender-advised priority of a stream.
// See http://http2.github.io/http2-spec/#rfc.section.6.3
type http2PriorityFrame struct {
http2FrameHeader
http2PriorityParam
}
// PriorityParam are the stream prioritzation parameters.
type http2PriorityParam struct {
// StreamDep is a 31-bit stream identifier for the
// stream that this stream depends on. Zero means no
// dependency.
StreamDep uint32
// Exclusive is whether the dependency is exclusive.
Exclusive bool
// Weight is the stream's zero-indexed weight. It should be
// set together with StreamDep, or neither should be set. Per
// the spec, "Add one to the value to obtain a weight between
// 1 and 256."
Weight uint8
}
func (p http2PriorityParam) IsZero() bool {
return p == http2PriorityParam{}
}
func http2parsePriorityFrame(_ *http2frameCache, fh http2FrameHeader, payload []byte) (http2Frame, error) {
if fh.StreamID == 0 {
return nil, http2connError{http2ErrCodeProtocol, "PRIORITY frame with stream ID 0"}
}
if len(payload) != 5 {
return nil, http2connError{http2ErrCodeFrameSize, fmt.Sprintf("PRIORITY frame payload size was %d; want 5", len(payload))}
}
v := binary.BigEndian.Uint32(payload[:4])
streamID := v & 0x7fffffff // mask off high bit
return &http2PriorityFrame{
http2FrameHeader: fh,
http2PriorityParam: http2PriorityParam{
Weight: payload[4],
StreamDep: streamID,
Exclusive: streamID != v, // was high bit set?
},
}, nil
}
// WritePriority writes a PRIORITY frame.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility to not call other Write methods concurrently.
func (f *http2Framer) WritePriority(streamID uint32, p http2PriorityParam) error {
if !http2validStreamID(streamID) && !f.AllowIllegalWrites {
return http2errStreamID
}
if !http2validStreamIDOrZero(p.StreamDep) {
return http2errDepStreamID
}
f.startWrite(http2FramePriority, 0, streamID)
v := p.StreamDep
if p.Exclusive {
v |= 1 << 31
}
f.writeUint32(v)
f.writeByte(p.Weight)
return f.endWrite()
}
// A RSTStreamFrame allows for abnormal termination of a stream.
// See http://http2.github.io/http2-spec/#rfc.section.6.4
type http2RSTStreamFrame struct {
http2FrameHeader
ErrCode http2ErrCode
}
func http2parseRSTStreamFrame(_ *http2frameCache, fh http2FrameHeader, p []byte) (http2Frame, error) {
if len(p) != 4 {
return nil, http2ConnectionError(http2ErrCodeFrameSize)
}
if fh.StreamID == 0 {
return nil, http2ConnectionError(http2ErrCodeProtocol)
}
return &http2RSTStreamFrame{fh, http2ErrCode(binary.BigEndian.Uint32(p[:4]))}, nil
}
// WriteRSTStream writes a RST_STREAM frame.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility to not call other Write methods concurrently.
func (f *http2Framer) WriteRSTStream(streamID uint32, code http2ErrCode) error {
if !http2validStreamID(streamID) && !f.AllowIllegalWrites {
return http2errStreamID
}
f.startWrite(http2FrameRSTStream, 0, streamID)
f.writeUint32(uint32(code))
return f.endWrite()
}
// A ContinuationFrame is used to continue a sequence of header block fragments.
// See http://http2.github.io/http2-spec/#rfc.section.6.10
type http2ContinuationFrame struct {
http2FrameHeader
headerFragBuf []byte
}
func http2parseContinuationFrame(_ *http2frameCache, fh http2FrameHeader, p []byte) (http2Frame, error) {
if fh.StreamID == 0 {
return nil, http2connError{http2ErrCodeProtocol, "CONTINUATION frame with stream ID 0"}
}
return &http2ContinuationFrame{fh, p}, nil
}
func (f *http2ContinuationFrame) HeaderBlockFragment() []byte {
f.checkValid()
return f.headerFragBuf
}
func (f *http2ContinuationFrame) HeadersEnded() bool {
return f.http2FrameHeader.Flags.Has(http2FlagContinuationEndHeaders)
}
// WriteContinuation writes a CONTINUATION frame.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility to not call other Write methods concurrently.
func (f *http2Framer) WriteContinuation(streamID uint32, endHeaders bool, headerBlockFragment []byte) error {
if !http2validStreamID(streamID) && !f.AllowIllegalWrites {
return http2errStreamID
}
var flags http2Flags
if endHeaders {
flags |= http2FlagContinuationEndHeaders
}
f.startWrite(http2FrameContinuation, flags, streamID)
f.wbuf = append(f.wbuf, headerBlockFragment...)
return f.endWrite()
}
// A PushPromiseFrame is used to initiate a server stream.
// See http://http2.github.io/http2-spec/#rfc.section.6.6
type http2PushPromiseFrame struct {
http2FrameHeader
PromiseID uint32
headerFragBuf []byte // not owned
}
func (f *http2PushPromiseFrame) HeaderBlockFragment() []byte {
f.checkValid()
return f.headerFragBuf
}
func (f *http2PushPromiseFrame) HeadersEnded() bool {
return f.http2FrameHeader.Flags.Has(http2FlagPushPromiseEndHeaders)
}
func http2parsePushPromise(_ *http2frameCache, fh http2FrameHeader, p []byte) (_ http2Frame, err error) {
pp := &http2PushPromiseFrame{
http2FrameHeader: fh,
}
if pp.StreamID == 0 {
// PUSH_PROMISE frames MUST be associated with an existing,
// peer-initiated stream. The stream identifier of a
// PUSH_PROMISE frame indicates the stream it is associated
// with. If the stream identifier field specifies the value
// 0x0, a recipient MUST respond with a connection error
// (Section 5.4.1) of type PROTOCOL_ERROR.
return nil, http2ConnectionError(http2ErrCodeProtocol)
}
// The PUSH_PROMISE frame includes optional padding.
// Padding fields and flags are identical to those defined for DATA frames
var padLength uint8
if fh.Flags.Has(http2FlagPushPromisePadded) {
if p, padLength, err = http2readByte(p); err != nil {
return
}
}
p, pp.PromiseID, err = http2readUint32(p)
if err != nil {
return
}
pp.PromiseID = pp.PromiseID & (1<<31 - 1)
if int(padLength) > len(p) {
// like the DATA frame, error out if padding is longer than the body.
return nil, http2ConnectionError(http2ErrCodeProtocol)
}
pp.headerFragBuf = p[:len(p)-int(padLength)]
return pp, nil
}
// PushPromiseParam are the parameters for writing a PUSH_PROMISE frame.
type http2PushPromiseParam struct {
// StreamID is the required Stream ID to initiate.
StreamID uint32
// PromiseID is the required Stream ID which this
// Push Promises
PromiseID uint32
// BlockFragment is part (or all) of a Header Block.
BlockFragment []byte
// EndHeaders indicates that this frame contains an entire
// header block and is not followed by any
// CONTINUATION frames.
EndHeaders bool
// PadLength is the optional number of bytes of zeros to add
// to this frame.
PadLength uint8
}
// WritePushPromise writes a single PushPromise Frame.
//
// As with Header Frames, This is the low level call for writing
// individual frames. Continuation frames are handled elsewhere.
//
// It will perform exactly one Write to the underlying Writer.
// It is the caller's responsibility to not call other Write methods concurrently.
func (f *http2Framer) WritePushPromise(p http2PushPromiseParam) error {
if !http2validStreamID(p.StreamID) && !f.AllowIllegalWrites {
return http2errStreamID
}
var flags http2Flags
if p.PadLength != 0 {
flags |= http2FlagPushPromisePadded
}
if p.EndHeaders {
flags |= http2FlagPushPromiseEndHeaders
}
f.startWrite(http2FramePushPromise, flags, p.StreamID)
if p.PadLength != 0 {
f.writeByte(p.PadLength)
}
if !http2validStreamID(p.PromiseID) && !f.AllowIllegalWrites {
return http2errStreamID
}
f.writeUint32(p.PromiseID)
f.wbuf = append(f.wbuf, p.BlockFragment...)
f.wbuf = append(f.wbuf, http2padZeros[:p.PadLength]...)
return f.endWrite()
}
// WriteRawFrame writes a raw frame. This can be used to write
// extension frames unknown to this package.
func (f *http2Framer) WriteRawFrame(t http2FrameType, flags http2Flags, streamID uint32, payload []byte) error {
f.startWrite(t, flags, streamID)
f.writeBytes(payload)
return f.endWrite()
}
func http2readByte(p []byte) (remain []byte, b byte, err error) {
if len(p) == 0 {
return nil, 0, io.ErrUnexpectedEOF
}
return p[1:], p[0], nil
}
func http2readUint32(p []byte) (remain []byte, v uint32, err error) {
if len(p) < 4 {
return nil, 0, io.ErrUnexpectedEOF
}
return p[4:], binary.BigEndian.Uint32(p[:4]), nil
}
type http2streamEnder interface {
StreamEnded() bool
}
type http2headersEnder interface {
HeadersEnded() bool
}
type http2headersOrContinuation interface {
http2headersEnder
HeaderBlockFragment() []byte
}
// A MetaHeadersFrame is the representation of one HEADERS frame and
// zero or more contiguous CONTINUATION frames and the decoding of
// their HPACK-encoded contents.
//
// This type of frame does not appear on the wire and is only returned
// by the Framer when Framer.ReadMetaHeaders is set.
type http2MetaHeadersFrame struct {
*http2HeadersFrame
// Fields are the fields contained in the HEADERS and
// CONTINUATION frames. The underlying slice is owned by the
// Framer and must not be retained after the next call to
// ReadFrame.
//
// Fields are guaranteed to be in the correct http2 order and
// not have unknown pseudo header fields or invalid header
// field names or values. Required pseudo header fields may be
// missing, however. Use the MetaHeadersFrame.Pseudo accessor
// method access pseudo headers.
Fields []hpack.HeaderField
// Truncated is whether the max header list size limit was hit
// and Fields is incomplete. The hpack decoder state is still
// valid, however.
Truncated bool
}
// PseudoValue returns the given pseudo header field's value.
// The provided pseudo field should not contain the leading colon.
func (mh *http2MetaHeadersFrame) PseudoValue(pseudo string) string {
for _, hf := range mh.Fields {
if !hf.IsPseudo() {
return ""
}
if hf.Name[1:] == pseudo {
return hf.Value
}
}
return ""
}
// RegularFields returns the regular (non-pseudo) header fields of mh.
// The caller does not own the returned slice.
func (mh *http2MetaHeadersFrame) RegularFields() []hpack.HeaderField {
for i, hf := range mh.Fields {
if !hf.IsPseudo() {
return mh.Fields[i:]
}
}
return nil
}
// PseudoFields returns the pseudo header fields of mh.
// The caller does not own the returned slice.
func (mh *http2MetaHeadersFrame) PseudoFields() []hpack.HeaderField {
for i, hf := range mh.Fields {
if !hf.IsPseudo() {
return mh.Fields[:i]
}
}
return mh.Fields
}
func (mh *http2MetaHeadersFrame) checkPseudos() error {
var isRequest, isResponse bool
pf := mh.PseudoFields()
for i, hf := range pf {
switch hf.Name {
case ":method", ":path", ":scheme", ":authority":
isRequest = true
case ":status":
isResponse = true
default:
return http2pseudoHeaderError(hf.Name)
}
// Check for duplicates.
// This would be a bad algorithm, but N is 4.
// And this doesn't allocate.
for _, hf2 := range pf[:i] {
if hf.Name == hf2.Name {
return http2duplicatePseudoHeaderError(hf.Name)
}
}
}
if isRequest && isResponse {
return http2errMixPseudoHeaderTypes
}
return nil
}
func (fr *http2Framer) maxHeaderStringLen() int {
v := fr.maxHeaderListSize()
if uint32(int(v)) == v {
return int(v)
}
// They had a crazy big number for MaxHeaderBytes anyway,
// so give them unlimited header lengths:
return 0
}
// readMetaFrame returns 0 or more CONTINUATION frames from fr and
// merge them into the provided hf and returns a MetaHeadersFrame
// with the decoded hpack values.
func (fr *http2Framer) readMetaFrame(hf *http2HeadersFrame) (*http2MetaHeadersFrame, error) {
if fr.AllowIllegalReads {
return nil, errors.New("illegal use of AllowIllegalReads with ReadMetaHeaders")
}
mh := &http2MetaHeadersFrame{
http2HeadersFrame: hf,
}
var remainSize = fr.maxHeaderListSize()
var sawRegular bool
var invalid error // pseudo header field errors
hdec := fr.ReadMetaHeaders
hdec.SetEmitEnabled(true)
hdec.SetMaxStringLength(fr.maxHeaderStringLen())
hdec.SetEmitFunc(func(hf hpack.HeaderField) {
if http2VerboseLogs && fr.logReads {
fr.debugReadLoggerf("http2: decoded hpack field %+v", hf)
}
if !httpguts.ValidHeaderFieldValue(hf.Value) {
invalid = http2headerFieldValueError(hf.Value)
}
isPseudo := strings.HasPrefix(hf.Name, ":")
if isPseudo {
if sawRegular {
invalid = http2errPseudoAfterRegular
}
} else {
sawRegular = true
if !http2validWireHeaderFieldName(hf.Name) {
invalid = http2headerFieldNameError(hf.Name)
}
}
if invalid != nil {
hdec.SetEmitEnabled(false)
return
}
size := hf.Size()
if size > remainSize {
hdec.SetEmitEnabled(false)
mh.Truncated = true
return
}
remainSize -= size
mh.Fields = append(mh.Fields, hf)
})
// Lose reference to MetaHeadersFrame:
defer hdec.SetEmitFunc(func(hf hpack.HeaderField) {})
var hc http2headersOrContinuation = hf
for {
frag := hc.HeaderBlockFragment()
if _, err := hdec.Write(frag); err != nil {
return nil, http2ConnectionError(http2ErrCodeCompression)
}
if hc.HeadersEnded() {
break
}
if f, err := fr.ReadFrame(); err != nil {
return nil, err
} else {
hc = f.(*http2ContinuationFrame) // guaranteed by checkFrameOrder
}
}
mh.http2HeadersFrame.headerFragBuf = nil
mh.http2HeadersFrame.invalidate()
if err := hdec.Close(); err != nil {
return nil, http2ConnectionError(http2ErrCodeCompression)
}
if invalid != nil {
fr.errDetail = invalid
if http2VerboseLogs {
log.Printf("http2: invalid header: %v", invalid)
}
return nil, http2StreamError{mh.StreamID, http2ErrCodeProtocol, invalid}
}
if err := mh.checkPseudos(); err != nil {
fr.errDetail = err
if http2VerboseLogs {
log.Printf("http2: invalid pseudo headers: %v", err)
}
return nil, http2StreamError{mh.StreamID, http2ErrCodeProtocol, err}
}
return mh, nil
}
func http2summarizeFrame(f http2Frame) string {
var buf bytes.Buffer
f.Header().writeDebug(&buf)
switch f := f.(type) {
case *http2SettingsFrame:
n := 0
f.ForeachSetting(func(s http2Setting) error {
n++
if n == 1 {
buf.WriteString(", settings:")
}
fmt.Fprintf(&buf, " %v=%v,", s.ID, s.Val)
return nil
})
if n > 0 {
buf.Truncate(buf.Len() - 1) // remove trailing comma
}
case *http2DataFrame:
data := f.Data()
const max = 256
if len(data) > max {
data = data[:max]
}
fmt.Fprintf(&buf, " data=%q", data)
if len(f.Data()) > max {
fmt.Fprintf(&buf, " (%d bytes omitted)", len(f.Data())-max)
}
case *http2WindowUpdateFrame:
if f.StreamID == 0 {
buf.WriteString(" (conn)")
}
fmt.Fprintf(&buf, " incr=%v", f.Increment)
case *http2PingFrame:
fmt.Fprintf(&buf, " ping=%q", f.Data[:])
case *http2GoAwayFrame:
fmt.Fprintf(&buf, " LastStreamID=%v ErrCode=%v Debug=%q",
f.LastStreamID, f.ErrCode, f.debugData)
case *http2RSTStreamFrame:
fmt.Fprintf(&buf, " ErrCode=%v", f.ErrCode)
}
return buf.String()
}
func http2traceHasWroteHeaderField(trace *httptrace.ClientTrace) bool {
return trace != nil && trace.WroteHeaderField != nil
}
func http2traceWroteHeaderField(trace *httptrace.ClientTrace, k, v string) {
if trace != nil && trace.WroteHeaderField != nil {
trace.WroteHeaderField(k, []string{v})
}
}
func http2traceGot1xxResponseFunc(trace *httptrace.ClientTrace) func(int, textproto.MIMEHeader) error {
if trace != nil {
return trace.Got1xxResponse
}
return nil
}
var http2DebugGoroutines = os.Getenv("DEBUG_HTTP2_GOROUTINES") == "1"
type http2goroutineLock uint64
func http2newGoroutineLock() http2goroutineLock {
if !http2DebugGoroutines {
return 0
}
return http2goroutineLock(http2curGoroutineID())
}
func (g http2goroutineLock) check() {
if !http2DebugGoroutines {
return
}
if http2curGoroutineID() != uint64(g) {
panic("running on the wrong goroutine")
}
}
func (g http2goroutineLock) checkNotOn() {
if !http2DebugGoroutines {
return
}
if http2curGoroutineID() == uint64(g) {
panic("running on the wrong goroutine")
}
}
var http2goroutineSpace = []byte("goroutine ")
func http2curGoroutineID() uint64 {
bp := http2littleBuf.Get().(*[]byte)
defer http2littleBuf.Put(bp)
b := *bp
b = b[:runtime.Stack(b, false)]
// Parse the 4707 out of "goroutine 4707 ["
b = bytes.TrimPrefix(b, http2goroutineSpace)
i := bytes.IndexByte(b, ' ')
if i < 0 {
panic(fmt.Sprintf("No space found in %q", b))
}
b = b[:i]
n, err := http2parseUintBytes(b, 10, 64)
if err != nil {
panic(fmt.Sprintf("Failed to parse goroutine ID out of %q: %v", b, err))
}
return n
}
var http2littleBuf = sync.Pool{
New: func() interface{} {
buf := make([]byte, 64)
return &buf
},
}
// parseUintBytes is like strconv.ParseUint, but using a []byte.
func http2parseUintBytes(s []byte, base int, bitSize int) (n uint64, err error) {
var cutoff, maxVal uint64
if bitSize == 0 {
bitSize = int(strconv.IntSize)
}
s0 := s
switch {
case len(s) < 1:
err = strconv.ErrSyntax
goto Error
case 2 <= base && base <= 36:
// valid base; nothing to do
case base == 0:
// Look for octal, hex prefix.
switch {
case s[0] == '0' && len(s) > 1 && (s[1] == 'x' || s[1] == 'X'):
base = 16
s = s[2:]
if len(s) < 1 {
err = strconv.ErrSyntax
goto Error
}
case s[0] == '0':
base = 8
default:
base = 10
}
default:
err = errors.New("invalid base " + strconv.Itoa(base))
goto Error
}
n = 0
cutoff = http2cutoff64(base)
maxVal = 1<<uint(bitSize) - 1
for i := 0; i < len(s); i++ {
var v byte
d := s[i]
switch {
case '0' <= d && d <= '9':
v = d - '0'
case 'a' <= d && d <= 'z':
v = d - 'a' + 10
case 'A' <= d && d <= 'Z':
v = d - 'A' + 10
default:
n = 0
err = strconv.ErrSyntax
goto Error
}
if int(v) >= base {
n = 0
err = strconv.ErrSyntax
goto Error
}
if n >= cutoff {
// n*base overflows
n = 1<<64 - 1
err = strconv.ErrRange
goto Error
}
n *= uint64(base)
n1 := n + uint64(v)
if n1 < n || n1 > maxVal {
// n+v overflows
n = 1<<64 - 1
err = strconv.ErrRange
goto Error
}
n = n1
}
return n, nil
Error:
return n, &strconv.NumError{Func: "ParseUint", Num: string(s0), Err: err}
}
// Return the first number n such that n*base >= 1<<64.
func http2cutoff64(base int) uint64 {
if base < 2 {
return 0
}
return (1<<64-1)/uint64(base) + 1
}
var (
http2commonBuildOnce sync.Once
http2commonLowerHeader map[string]string // Go-Canonical-Case -> lower-case
http2commonCanonHeader map[string]string // lower-case -> Go-Canonical-Case
)
func http2buildCommonHeaderMapsOnce() {
http2commonBuildOnce.Do(http2buildCommonHeaderMaps)
}
func http2buildCommonHeaderMaps() {
common := []string{
"accept",
"accept-charset",
"accept-encoding",
"accept-language",
"accept-ranges",
"age",
"access-control-allow-origin",
"allow",
"authorization",
"cache-control",
"content-disposition",
"content-encoding",
"content-language",
"content-length",
"content-location",
"content-range",
"content-type",
"cookie",
"date",
"etag",
"expect",
"expires",
"from",
"host",
"if-match",
"if-modified-since",
"if-none-match",
"if-unmodified-since",
"last-modified",
"link",
"location",
"max-forwards",
"proxy-authenticate",
"proxy-authorization",
"range",
"referer",
"refresh",
"retry-after",
"server",
"set-cookie",
"strict-transport-security",
"trailer",
"transfer-encoding",
"user-agent",
"vary",
"via",
"www-authenticate",
}
http2commonLowerHeader = make(map[string]string, len(common))
http2commonCanonHeader = make(map[string]string, len(common))
for _, v := range common {
chk := CanonicalHeaderKey(v)
http2commonLowerHeader[chk] = v
http2commonCanonHeader[v] = chk
}
}
func http2lowerHeader(v string) string {
http2buildCommonHeaderMapsOnce()
if s, ok := http2commonLowerHeader[v]; ok {
return s
}
return strings.ToLower(v)
}
var (
http2VerboseLogs bool
http2logFrameWrites bool
http2logFrameReads bool
http2inTests bool
)
func init() {
e := os.Getenv("GODEBUG")
if strings.Contains(e, "http2debug=1") {
http2VerboseLogs = true
}
if strings.Contains(e, "http2debug=2") {
http2VerboseLogs = true
http2logFrameWrites = true
http2logFrameReads = true
}
}
const (
// ClientPreface is the string that must be sent by new
// connections from clients.
http2ClientPreface = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"
// SETTINGS_MAX_FRAME_SIZE default
// http://http2.github.io/http2-spec/#rfc.section.6.5.2
http2initialMaxFrameSize = 16384
// NextProtoTLS is the NPN/ALPN protocol negotiated during
// HTTP/2's TLS setup.
http2NextProtoTLS = "h2"
// http://http2.github.io/http2-spec/#SettingValues
http2initialHeaderTableSize = 4096
http2initialWindowSize = 65535 // 6.9.2 Initial Flow Control Window Size
http2defaultMaxReadFrameSize = 1 << 20
)
var (
http2clientPreface = []byte(http2ClientPreface)
)
type http2streamState int
// HTTP/2 stream states.
//
// See http://tools.ietf.org/html/rfc7540#section-5.1.
//
// For simplicity, the server code merges "reserved (local)" into
// "half-closed (remote)". This is one less state transition to track.
// The only downside is that we send PUSH_PROMISEs slightly less
// liberally than allowable. More discussion here:
// https://lists.w3.org/Archives/Public/ietf-http-wg/2016JulSep/0599.html
//
// "reserved (remote)" is omitted since the client code does not
// support server push.
const (
http2stateIdle http2streamState = iota
http2stateOpen
http2stateHalfClosedLocal
http2stateHalfClosedRemote
http2stateClosed
)
var http2stateName = [...]string{
http2stateIdle: "Idle",
http2stateOpen: "Open",
http2stateHalfClosedLocal: "HalfClosedLocal",
http2stateHalfClosedRemote: "HalfClosedRemote",
http2stateClosed: "Closed",
}
func (st http2streamState) String() string {
return http2stateName[st]
}
// Setting is a setting parameter: which setting it is, and its value.
type http2Setting struct {
// ID is which setting is being set.
// See http://http2.github.io/http2-spec/#SettingValues
ID http2SettingID
// Val is the value.
Val uint32
}
func (s http2Setting) String() string {
return fmt.Sprintf("[%v = %d]", s.ID, s.Val)
}
// Valid reports whether the setting is valid.
func (s http2Setting) Valid() error {
// Limits and error codes from 6.5.2 Defined SETTINGS Parameters
switch s.ID {
case http2SettingEnablePush:
if s.Val != 1 && s.Val != 0 {
return http2ConnectionError(http2ErrCodeProtocol)
}
case http2SettingInitialWindowSize:
if s.Val > 1<<31-1 {
return http2ConnectionError(http2ErrCodeFlowControl)
}
case http2SettingMaxFrameSize:
if s.Val < 16384 || s.Val > 1<<24-1 {
return http2ConnectionError(http2ErrCodeProtocol)
}
}
return nil
}
// A SettingID is an HTTP/2 setting as defined in
// http://http2.github.io/http2-spec/#iana-settings
type http2SettingID uint16
const (
http2SettingHeaderTableSize http2SettingID = 0x1
http2SettingEnablePush http2SettingID = 0x2
http2SettingMaxConcurrentStreams http2SettingID = 0x3
http2SettingInitialWindowSize http2SettingID = 0x4
http2SettingMaxFrameSize http2SettingID = 0x5
http2SettingMaxHeaderListSize http2SettingID = 0x6
)
var http2settingName = map[http2SettingID]string{
http2SettingHeaderTableSize: "HEADER_TABLE_SIZE",
http2SettingEnablePush: "ENABLE_PUSH",
http2SettingMaxConcurrentStreams: "MAX_CONCURRENT_STREAMS",
http2SettingInitialWindowSize: "INITIAL_WINDOW_SIZE",
http2SettingMaxFrameSize: "MAX_FRAME_SIZE",
http2SettingMaxHeaderListSize: "MAX_HEADER_LIST_SIZE",
}
func (s http2SettingID) String() string {
if v, ok := http2settingName[s]; ok {
return v
}
return fmt.Sprintf("UNKNOWN_SETTING_%d", uint16(s))
}
var (
http2errInvalidHeaderFieldName = errors.New("http2: invalid header field name")
http2errInvalidHeaderFieldValue = errors.New("http2: invalid header field value")
)
// validWireHeaderFieldName reports whether v is a valid header field
// name (key). See httpguts.ValidHeaderName for the base rules.
//
// Further, http2 says:
// "Just as in HTTP/1.x, header field names are strings of ASCII
// characters that are compared in a case-insensitive
// fashion. However, header field names MUST be converted to
// lowercase prior to their encoding in HTTP/2. "
func http2validWireHeaderFieldName(v string) bool {
if len(v) == 0 {
return false
}
for _, r := range v {
if !httpguts.IsTokenRune(r) {
return false
}
if 'A' <= r && r <= 'Z' {
return false
}
}
return true
}
func http2httpCodeString(code int) string {
switch code {
case 200:
return "200"
case 404:
return "404"
}
return strconv.Itoa(code)
}
// from pkg io
type http2stringWriter interface {
WriteString(s string) (n int, err error)
}
// A gate lets two goroutines coordinate their activities.
type http2gate chan struct{}
func (g http2gate) Done() { g <- struct{}{} }
func (g http2gate) Wait() { <-g }
// A closeWaiter is like a sync.WaitGroup but only goes 1 to 0 (open to closed).
type http2closeWaiter chan struct{}
// Init makes a closeWaiter usable.
// It exists because so a closeWaiter value can be placed inside a
// larger struct and have the Mutex and Cond's memory in the same
// allocation.
func (cw *http2closeWaiter) Init() {
*cw = make(chan struct{})
}
// Close marks the closeWaiter as closed and unblocks any waiters.
func (cw http2closeWaiter) Close() {
close(cw)
}
// Wait waits for the closeWaiter to become closed.
func (cw http2closeWaiter) Wait() {
<-cw
}
// bufferedWriter is a buffered writer that writes to w.
// Its buffered writer is lazily allocated as needed, to minimize
// idle memory usage with many connections.
type http2bufferedWriter struct {
w io.Writer // immutable
bw *bufio.Writer // non-nil when data is buffered
}
func http2newBufferedWriter(w io.Writer) *http2bufferedWriter {
return &http2bufferedWriter{w: w}
}
// bufWriterPoolBufferSize is the size of bufio.Writer's
// buffers created using bufWriterPool.
//
// TODO: pick a less arbitrary value? this is a bit under
// (3 x typical 1500 byte MTU) at least. Other than that,
// not much thought went into it.
const http2bufWriterPoolBufferSize = 4 << 10
var http2bufWriterPool = sync.Pool{
New: func() interface{} {
return bufio.NewWriterSize(nil, http2bufWriterPoolBufferSize)
},
}
func (w *http2bufferedWriter) Available() int {
if w.bw == nil {
return http2bufWriterPoolBufferSize
}
return w.bw.Available()
}
func (w *http2bufferedWriter) Write(p []byte) (n int, err error) {
if w.bw == nil {
bw := http2bufWriterPool.Get().(*bufio.Writer)
bw.Reset(w.w)
w.bw = bw
}
return w.bw.Write(p)
}
func (w *http2bufferedWriter) Flush() error {
bw := w.bw
if bw == nil {
return nil
}
err := bw.Flush()
bw.Reset(nil)
http2bufWriterPool.Put(bw)
w.bw = nil
return err
}
func http2mustUint31(v int32) uint32 {
if v < 0 || v > 2147483647 {
panic("out of range")
}
return uint32(v)
}
// bodyAllowedForStatus reports whether a given response status code
// permits a body. See RFC 7230, section 3.3.
func http2bodyAllowedForStatus(status int) bool {
switch {
case status >= 100 && status <= 199:
return false
case status == 204:
return false
case status == 304:
return false
}
return true
}
type http2httpError struct {
msg string
timeout bool
}
func (e *http2httpError) Error() string { return e.msg }
func (e *http2httpError) Timeout() bool { return e.timeout }
func (e *http2httpError) Temporary() bool { return true }
var http2errTimeout error = &http2httpError{msg: "http2: timeout awaiting response headers", timeout: true}
type http2connectionStater interface {
ConnectionState() tls.ConnectionState
}
var http2sorterPool = sync.Pool{New: func() interface{} { return new(http2sorter) }}
type http2sorter struct {
v []string // owned by sorter
}
func (s *http2sorter) Len() int { return len(s.v) }
func (s *http2sorter) Swap(i, j int) { s.v[i], s.v[j] = s.v[j], s.v[i] }
func (s *http2sorter) Less(i, j int) bool { return s.v[i] < s.v[j] }
// Keys returns the sorted keys of h.
//
// The returned slice is only valid until s used again or returned to
// its pool.
func (s *http2sorter) Keys(h Header) []string {
keys := s.v[:0]
for k := range h {
keys = append(keys, k)
}
s.v = keys
sort.Sort(s)
return keys
}
func (s *http2sorter) SortStrings(ss []string) {
// Our sorter works on s.v, which sorter owns, so
// stash it away while we sort the user's buffer.
save := s.v
s.v = ss
sort.Sort(s)
s.v = save
}
// validPseudoPath reports whether v is a valid :path pseudo-header
// value. It must be either:
//
// *) a non-empty string starting with '/'
// *) the string '*', for OPTIONS requests.
//
// For now this is only used a quick check for deciding when to clean
// up Opaque URLs before sending requests from the Transport.
// See golang.org/issue/16847
//
// We used to enforce that the path also didn't start with "//", but
// Google's GFE accepts such paths and Chrome sends them, so ignore
// that part of the spec. See golang.org/issue/19103.
func http2validPseudoPath(v string) bool {
return (len(v) > 0 && v[0] == '/') || v == "*"
}
// pipe is a goroutine-safe io.Reader/io.Writer pair. It's like
// io.Pipe except there are no PipeReader/PipeWriter halves, and the
// underlying buffer is an interface. (io.Pipe is always unbuffered)
type http2pipe struct {
mu sync.Mutex
c sync.Cond // c.L lazily initialized to &p.mu
b http2pipeBuffer // nil when done reading
err error // read error once empty. non-nil means closed.
breakErr error // immediate read error (caller doesn't see rest of b)
donec chan struct{} // closed on error
readFn func() // optional code to run in Read before error
}
type http2pipeBuffer interface {
Len() int
io.Writer
io.Reader
}
func (p *http2pipe) Len() int {
p.mu.Lock()
defer p.mu.Unlock()
if p.b == nil {
return 0
}
return p.b.Len()
}
// Read waits until data is available and copies bytes
// from the buffer into p.
func (p *http2pipe) Read(d []byte) (n int, err error) {
p.mu.Lock()
defer p.mu.Unlock()
if p.c.L == nil {
p.c.L = &p.mu
}
for {
if p.breakErr != nil {
return 0, p.breakErr
}
if p.b != nil && p.b.Len() > 0 {
return p.b.Read(d)
}
if p.err != nil {
if p.readFn != nil {
p.readFn() // e.g. copy trailers
p.readFn = nil // not sticky like p.err
}
p.b = nil
return 0, p.err
}
p.c.Wait()
}
}
var http2errClosedPipeWrite = errors.New("write on closed buffer")
// Write copies bytes from p into the buffer and wakes a reader.
// It is an error to write more data than the buffer can hold.
func (p *http2pipe) Write(d []byte) (n int, err error) {
p.mu.Lock()
defer p.mu.Unlock()
if p.c.L == nil {
p.c.L = &p.mu
}
defer p.c.Signal()
if p.err != nil {
return 0, http2errClosedPipeWrite
}
if p.breakErr != nil {
return len(d), nil // discard when there is no reader
}
return p.b.Write(d)
}
// CloseWithError causes the next Read (waking up a current blocked
// Read if needed) to return the provided err after all data has been
// read.
//
// The error must be non-nil.
func (p *http2pipe) CloseWithError(err error) { p.closeWithError(&p.err, err, nil) }
// BreakWithError causes the next Read (waking up a current blocked
// Read if needed) to return the provided err immediately, without
// waiting for unread data.
func (p *http2pipe) BreakWithError(err error) { p.closeWithError(&p.breakErr, err, nil) }
// closeWithErrorAndCode is like CloseWithError but also sets some code to run
// in the caller's goroutine before returning the error.
func (p *http2pipe) closeWithErrorAndCode(err error, fn func()) { p.closeWithError(&p.err, err, fn) }
func (p *http2pipe) closeWithError(dst *error, err error, fn func()) {
if err == nil {
panic("err must be non-nil")
}
p.mu.Lock()
defer p.mu.Unlock()
if p.c.L == nil {
p.c.L = &p.mu
}
defer p.c.Signal()
if *dst != nil {
// Already been done.
return
}
p.readFn = fn
if dst == &p.breakErr {
p.b = nil
}
*dst = err
p.closeDoneLocked()
}
// requires p.mu be held.
func (p *http2pipe) closeDoneLocked() {
if p.donec == nil {
return
}
// Close if unclosed. This isn't racy since we always
// hold p.mu while closing.
select {
case <-p.donec:
default:
close(p.donec)
}
}
// Err returns the error (if any) first set by BreakWithError or CloseWithError.
func (p *http2pipe) Err() error {
p.mu.Lock()
defer p.mu.Unlock()
if p.breakErr != nil {
return p.breakErr
}
return p.err
}
// Done returns a channel which is closed if and when this pipe is closed
// with CloseWithError.
func (p *http2pipe) Done() <-chan struct{} {
p.mu.Lock()
defer p.mu.Unlock()
if p.donec == nil {
p.donec = make(chan struct{})
if p.err != nil || p.breakErr != nil {
// Already hit an error.
p.closeDoneLocked()
}
}
return p.donec
}
const (
http2prefaceTimeout = 10 * time.Second
http2firstSettingsTimeout = 2 * time.Second // should be in-flight with preface anyway
http2handlerChunkWriteSize = 4 << 10
http2defaultMaxStreams = 250 // TODO: make this 100 as the GFE seems to?
)
var (
http2errClientDisconnected = errors.New("client disconnected")
http2errClosedBody = errors.New("body closed by handler")
http2errHandlerComplete = errors.New("http2: request body closed due to handler exiting")
http2errStreamClosed = errors.New("http2: stream closed")
)
var http2responseWriterStatePool = sync.Pool{
New: func() interface{} {
rws := &http2responseWriterState{}
rws.bw = bufio.NewWriterSize(http2chunkWriter{rws}, http2handlerChunkWriteSize)
return rws
},
}
// Test hooks.
var (
http2testHookOnConn func()
http2testHookGetServerConn func(*http2serverConn)
http2testHookOnPanicMu *sync.Mutex // nil except in tests
http2testHookOnPanic func(sc *http2serverConn, panicVal interface{}) (rePanic bool)
)
// Server is an HTTP/2 server.
type http2Server struct {
// MaxHandlers limits the number of http.Handler ServeHTTP goroutines
// which may run at a time over all connections.
// Negative or zero no limit.
// TODO: implement
MaxHandlers int
// MaxConcurrentStreams optionally specifies the number of
// concurrent streams that each client may have open at a
// time. This is unrelated to the number of http.Handler goroutines
// which may be active globally, which is MaxHandlers.
// If zero, MaxConcurrentStreams defaults to at least 100, per
// the HTTP/2 spec's recommendations.
MaxConcurrentStreams uint32
// MaxReadFrameSize optionally specifies the largest frame
// this server is willing to read. A valid value is between
// 16k and 16M, inclusive. If zero or otherwise invalid, a
// default value is used.
MaxReadFrameSize uint32
// PermitProhibitedCipherSuites, if true, permits the use of
// cipher suites prohibited by the HTTP/2 spec.
PermitProhibitedCipherSuites bool
// IdleTimeout specifies how long until idle clients should be
// closed with a GOAWAY frame. PING frames are not considered
// activity for the purposes of IdleTimeout.
IdleTimeout time.Duration
// MaxUploadBufferPerConnection is the size of the initial flow
// control window for each connections. The HTTP/2 spec does not
// allow this to be smaller than 65535 or larger than 2^32-1.
// If the value is outside this range, a default value will be
// used instead.
MaxUploadBufferPerConnection int32
// MaxUploadBufferPerStream is the size of the initial flow control
// window for each stream. The HTTP/2 spec does not allow this to
// be larger than 2^32-1. If the value is zero or larger than the
// maximum, a default value will be used instead.
MaxUploadBufferPerStream int32
// NewWriteScheduler constructs a write scheduler for a connection.
// If nil, a default scheduler is chosen.
NewWriteScheduler func() http2WriteScheduler
// Internal state. This is a pointer (rather than embedded directly)
// so that we don't embed a Mutex in this struct, which will make the
// struct non-copyable, which might break some callers.
state *http2serverInternalState
}
func (s *http2Server) initialConnRecvWindowSize() int32 {
if s.MaxUploadBufferPerConnection > http2initialWindowSize {
return s.MaxUploadBufferPerConnection
}
return 1 << 20
}
func (s *http2Server) initialStreamRecvWindowSize() int32 {
if s.MaxUploadBufferPerStream > 0 {
return s.MaxUploadBufferPerStream
}
return 1 << 20
}
func (s *http2Server) maxReadFrameSize() uint32 {
if v := s.MaxReadFrameSize; v >= http2minMaxFrameSize && v <= http2maxFrameSize {
return v
}
return http2defaultMaxReadFrameSize
}
func (s *http2Server) maxConcurrentStreams() uint32 {
if v := s.MaxConcurrentStreams; v > 0 {
return v
}
return http2defaultMaxStreams
}
type http2serverInternalState struct {
mu sync.Mutex
activeConns map[*http2serverConn]struct{}
}
func (s *http2serverInternalState) registerConn(sc *http2serverConn) {
if s == nil {
return // if the Server was used without calling ConfigureServer
}
s.mu.Lock()
s.activeConns[sc] = struct{}{}
s.mu.Unlock()
}
func (s *http2serverInternalState) unregisterConn(sc *http2serverConn) {
if s == nil {
return // if the Server was used without calling ConfigureServer
}
s.mu.Lock()
delete(s.activeConns, sc)
s.mu.Unlock()
}
func (s *http2serverInternalState) startGracefulShutdown() {
if s == nil {
return // if the Server was used without calling ConfigureServer
}
s.mu.Lock()
for sc := range s.activeConns {
sc.startGracefulShutdown()
}
s.mu.Unlock()
}
// ConfigureServer adds HTTP/2 support to a net/http Server.
//
// The configuration conf may be nil.
//
// ConfigureServer must be called before s begins serving.
func http2ConfigureServer(s *Server, conf *http2Server) error {
if s == nil {
panic("nil *http.Server")
}
if conf == nil {
conf = new(http2Server)
}
conf.state = &http2serverInternalState{activeConns: make(map[*http2serverConn]struct{})}
if h1, h2 := s, conf; h2.IdleTimeout == 0 {
if h1.IdleTimeout != 0 {
h2.IdleTimeout = h1.IdleTimeout
} else {
h2.IdleTimeout = h1.ReadTimeout
}
}
s.RegisterOnShutdown(conf.state.startGracefulShutdown)
if s.TLSConfig == nil {
s.TLSConfig = new(tls.Config)
} else if s.TLSConfig.CipherSuites != nil {
// If they already provided a CipherSuite list, return
// an error if it has a bad order or is missing
// ECDHE_RSA_WITH_AES_128_GCM_SHA256 or ECDHE_ECDSA_WITH_AES_128_GCM_SHA256.
haveRequired := false
sawBad := false
for i, cs := range s.TLSConfig.CipherSuites {
switch cs {
case tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
// Alternative MTI cipher to not discourage ECDSA-only servers.
// See http://golang.org/cl/30721 for further information.
tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256:
haveRequired = true
}
if http2isBadCipher(cs) {
sawBad = true
} else if sawBad {
return fmt.Errorf("http2: TLSConfig.CipherSuites index %d contains an HTTP/2-approved cipher suite (%#04x), but it comes after unapproved cipher suites. With this configuration, clients that don't support previous, approved cipher suites may be given an unapproved one and reject the connection.", i, cs)
}
}
if !haveRequired {
return fmt.Errorf("http2: TLSConfig.CipherSuites is missing an HTTP/2-required AES_128_GCM_SHA256 cipher.")
}
}
// Note: not setting MinVersion to tls.VersionTLS12,
// as we don't want to interfere with HTTP/1.1 traffic
// on the user's server. We enforce TLS 1.2 later once
// we accept a connection. Ideally this should be done
// during next-proto selection, but using TLS <1.2 with
// HTTP/2 is still the client's bug.
s.TLSConfig.PreferServerCipherSuites = true
haveNPN := false
for _, p := range s.TLSConfig.NextProtos {
if p == http2NextProtoTLS {
haveNPN = true
break
}
}
if !haveNPN {
s.TLSConfig.NextProtos = append(s.TLSConfig.NextProtos, http2NextProtoTLS)
}
if s.TLSNextProto == nil {
s.TLSNextProto = map[string]func(*Server, *tls.Conn, Handler){}
}
protoHandler := func(hs *Server, c *tls.Conn, h Handler) {
if http2testHookOnConn != nil {
http2testHookOnConn()
}
conf.ServeConn(c, &http2ServeConnOpts{
Handler: h,
BaseConfig: hs,
})
}
s.TLSNextProto[http2NextProtoTLS] = protoHandler
return nil
}
// ServeConnOpts are options for the Server.ServeConn method.
type http2ServeConnOpts struct {
// BaseConfig optionally sets the base configuration
// for values. If nil, defaults are used.
BaseConfig *Server
// Handler specifies which handler to use for processing
// requests. If nil, BaseConfig.Handler is used. If BaseConfig
// or BaseConfig.Handler is nil, http.DefaultServeMux is used.
Handler Handler
}
func (o *http2ServeConnOpts) baseConfig() *Server {
if o != nil && o.BaseConfig != nil {
return o.BaseConfig
}
return new(Server)
}
func (o *http2ServeConnOpts) handler() Handler {
if o != nil {
if o.Handler != nil {
return o.Handler
}
if o.BaseConfig != nil && o.BaseConfig.Handler != nil {
return o.BaseConfig.Handler
}
}
return DefaultServeMux
}
// ServeConn serves HTTP/2 requests on the provided connection and
// blocks until the connection is no longer readable.
//
// ServeConn starts speaking HTTP/2 assuming that c has not had any
// reads or writes. It writes its initial settings frame and expects
// to be able to read the preface and settings frame from the
// client. If c has a ConnectionState method like a *tls.Conn, the
// ConnectionState is used to verify the TLS ciphersuite and to set
// the Request.TLS field in Handlers.
//
// ServeConn does not support h2c by itself. Any h2c support must be
// implemented in terms of providing a suitably-behaving net.Conn.
//
// The opts parameter is optional. If nil, default values are used.
func (s *http2Server) ServeConn(c net.Conn, opts *http2ServeConnOpts) {
baseCtx, cancel := http2serverConnBaseContext(c, opts)
defer cancel()
sc := &http2serverConn{
srv: s,
hs: opts.baseConfig(),
conn: c,
baseCtx: baseCtx,
remoteAddrStr: c.RemoteAddr().String(),
bw: http2newBufferedWriter(c),
handler: opts.handler(),
streams: make(map[uint32]*http2stream),
readFrameCh: make(chan http2readFrameResult),
wantWriteFrameCh: make(chan http2FrameWriteRequest, 8),
serveMsgCh: make(chan interface{}, 8),
wroteFrameCh: make(chan http2frameWriteResult, 1), // buffered; one send in writeFrameAsync
bodyReadCh: make(chan http2bodyReadMsg), // buffering doesn't matter either way
doneServing: make(chan struct{}),
clientMaxStreams: math.MaxUint32, // Section 6.5.2: "Initially, there is no limit to this value"
advMaxStreams: s.maxConcurrentStreams(),
initialStreamSendWindowSize: http2initialWindowSize,
maxFrameSize: http2initialMaxFrameSize,
headerTableSize: http2initialHeaderTableSize,
serveG: http2newGoroutineLock(),
pushEnabled: true,
}
s.state.registerConn(sc)
defer s.state.unregisterConn(sc)
// The net/http package sets the write deadline from the
// http.Server.WriteTimeout during the TLS handshake, but then
// passes the connection off to us with the deadline already set.
// Write deadlines are set per stream in serverConn.newStream.
// Disarm the net.Conn write deadline here.
if sc.hs.WriteTimeout != 0 {
sc.conn.SetWriteDeadline(time.Time{})
}
if s.NewWriteScheduler != nil {
sc.writeSched = s.NewWriteScheduler()
} else {
sc.writeSched = http2NewRandomWriteScheduler()
}
// These start at the RFC-specified defaults. If there is a higher
// configured value for inflow, that will be updated when we send a
// WINDOW_UPDATE shortly after sending SETTINGS.
sc.flow.add(http2initialWindowSize)
sc.inflow.add(http2initialWindowSize)
sc.hpackEncoder = hpack.NewEncoder(&sc.headerWriteBuf)
fr := http2NewFramer(sc.bw, c)
fr.ReadMetaHeaders = hpack.NewDecoder(http2initialHeaderTableSize, nil)
fr.MaxHeaderListSize = sc.maxHeaderListSize()
fr.SetMaxReadFrameSize(s.maxReadFrameSize())
sc.framer = fr
if tc, ok := c.(http2connectionStater); ok {
sc.tlsState = new(tls.ConnectionState)
*sc.tlsState = tc.ConnectionState()
// 9.2 Use of TLS Features
// An implementation of HTTP/2 over TLS MUST use TLS
// 1.2 or higher with the restrictions on feature set
// and cipher suite described in this section. Due to
// implementation limitations, it might not be
// possible to fail TLS negotiation. An endpoint MUST
// immediately terminate an HTTP/2 connection that
// does not meet the TLS requirements described in
// this section with a connection error (Section
// 5.4.1) of type INADEQUATE_SECURITY.
if sc.tlsState.Version < tls.VersionTLS12 {
sc.rejectConn(http2ErrCodeInadequateSecurity, "TLS version too low")
return
}
if sc.tlsState.ServerName == "" {
// Client must use SNI, but we don't enforce that anymore,
// since it was causing problems when connecting to bare IP
// addresses during development.
//
// TODO: optionally enforce? Or enforce at the time we receive
// a new request, and verify the ServerName matches the :authority?
// But that precludes proxy situations, perhaps.
//
// So for now, do nothing here again.
}
if !s.PermitProhibitedCipherSuites && http2isBadCipher(sc.tlsState.CipherSuite) {
// "Endpoints MAY choose to generate a connection error
// (Section 5.4.1) of type INADEQUATE_SECURITY if one of
// the prohibited cipher suites are negotiated."
//
// We choose that. In my opinion, the spec is weak
// here. It also says both parties must support at least
// TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 so there's no
// excuses here. If we really must, we could allow an
// "AllowInsecureWeakCiphers" option on the server later.
// Let's see how it plays out first.
sc.rejectConn(http2ErrCodeInadequateSecurity, fmt.Sprintf("Prohibited TLS 1.2 Cipher Suite: %x", sc.tlsState.CipherSuite))
return
}
}
if hook := http2testHookGetServerConn; hook != nil {
hook(sc)
}
sc.serve()
}
func http2serverConnBaseContext(c net.Conn, opts *http2ServeConnOpts) (ctx context.Context, cancel func()) {
ctx, cancel = context.WithCancel(context.Background())
ctx = context.WithValue(ctx, LocalAddrContextKey, c.LocalAddr())
if hs := opts.baseConfig(); hs != nil {
ctx = context.WithValue(ctx, ServerContextKey, hs)
}
return
}
func (sc *http2serverConn) rejectConn(err http2ErrCode, debug string) {
sc.vlogf("http2: server rejecting conn: %v, %s", err, debug)
// ignoring errors. hanging up anyway.
sc.framer.WriteGoAway(0, err, []byte(debug))
sc.bw.Flush()
sc.conn.Close()
}
type http2serverConn struct {
// Immutable:
srv *http2Server
hs *Server
conn net.Conn
bw *http2bufferedWriter // writing to conn
handler Handler
baseCtx context.Context
framer *http2Framer
doneServing chan struct{} // closed when serverConn.serve ends
readFrameCh chan http2readFrameResult // written by serverConn.readFrames
wantWriteFrameCh chan http2FrameWriteRequest // from handlers -> serve
wroteFrameCh chan http2frameWriteResult // from writeFrameAsync -> serve, tickles more frame writes
bodyReadCh chan http2bodyReadMsg // from handlers -> serve
serveMsgCh chan interface{} // misc messages & code to send to / run on the serve loop
flow http2flow // conn-wide (not stream-specific) outbound flow control
inflow http2flow // conn-wide inbound flow control
tlsState *tls.ConnectionState // shared by all handlers, like net/http
remoteAddrStr string
writeSched http2WriteScheduler
// Everything following is owned by the serve loop; use serveG.check():
serveG http2goroutineLock // used to verify funcs are on serve()
pushEnabled bool
sawFirstSettings bool // got the initial SETTINGS frame after the preface
needToSendSettingsAck bool
unackedSettings int // how many SETTINGS have we sent without ACKs?
clientMaxStreams uint32 // SETTINGS_MAX_CONCURRENT_STREAMS from client (our PUSH_PROMISE limit)
advMaxStreams uint32 // our SETTINGS_MAX_CONCURRENT_STREAMS advertised the client
curClientStreams uint32 // number of open streams initiated by the client
curPushedStreams uint32 // number of open streams initiated by server push
maxClientStreamID uint32 // max ever seen from client (odd), or 0 if there have been no client requests
maxPushPromiseID uint32 // ID of the last push promise (even), or 0 if there have been no pushes
streams map[uint32]*http2stream
initialStreamSendWindowSize int32
maxFrameSize int32
headerTableSize uint32
peerMaxHeaderListSize uint32 // zero means unknown (default)
canonHeader map[string]string // http2-lower-case -> Go-Canonical-Case
writingFrame bool // started writing a frame (on serve goroutine or separate)
writingFrameAsync bool // started a frame on its own goroutine but haven't heard back on wroteFrameCh
needsFrameFlush bool // last frame write wasn't a flush
inGoAway bool // we've started to or sent GOAWAY
inFrameScheduleLoop bool // whether we're in the scheduleFrameWrite loop
needToSendGoAway bool // we need to schedule a GOAWAY frame write
goAwayCode http2ErrCode
shutdownTimer *time.Timer // nil until used
idleTimer *time.Timer // nil if unused
// Owned by the writeFrameAsync goroutine:
headerWriteBuf bytes.Buffer
hpackEncoder *hpack.Encoder
// Used by startGracefulShutdown.
shutdownOnce sync.Once
}
func (sc *http2serverConn) maxHeaderListSize() uint32 {
n := sc.hs.MaxHeaderBytes
if n <= 0 {
n = DefaultMaxHeaderBytes
}
// http2's count is in a slightly different unit and includes 32 bytes per pair.
// So, take the net/http.Server value and pad it up a bit, assuming 10 headers.
const perFieldOverhead = 32 // per http2 spec
const typicalHeaders = 10 // conservative
return uint32(n + typicalHeaders*perFieldOverhead)
}
func (sc *http2serverConn) curOpenStreams() uint32 {
sc.serveG.check()
return sc.curClientStreams + sc.curPushedStreams
}
// stream represents a stream. This is the minimal metadata needed by
// the serve goroutine. Most of the actual stream state is owned by
// the http.Handler's goroutine in the responseWriter. Because the
// responseWriter's responseWriterState is recycled at the end of a
// handler, this struct intentionally has no pointer to the
// *responseWriter{,State} itself, as the Handler ending nils out the
// responseWriter's state field.
type http2stream struct {
// immutable:
sc *http2serverConn
id uint32
body *http2pipe // non-nil if expecting DATA frames
cw http2closeWaiter // closed wait stream transitions to closed state
ctx context.Context
cancelCtx func()
// owned by serverConn's serve loop:
bodyBytes int64 // body bytes seen so far
declBodyBytes int64 // or -1 if undeclared
flow http2flow // limits writing from Handler to client
inflow http2flow // what the client is allowed to POST/etc to us
parent *http2stream // or nil
numTrailerValues int64
weight uint8
state http2streamState
resetQueued bool // RST_STREAM queued for write; set by sc.resetStream
gotTrailerHeader bool // HEADER frame for trailers was seen
wroteHeaders bool // whether we wrote headers (not status 100)
writeDeadline *time.Timer // nil if unused
trailer Header // accumulated trailers
reqTrailer Header // handler's Request.Trailer
}
func (sc *http2serverConn) Framer() *http2Framer { return sc.framer }
func (sc *http2serverConn) CloseConn() error { return sc.conn.Close() }
func (sc *http2serverConn) Flush() error { return sc.bw.Flush() }
func (sc *http2serverConn) HeaderEncoder() (*hpack.Encoder, *bytes.Buffer) {
return sc.hpackEncoder, &sc.headerWriteBuf
}
func (sc *http2serverConn) state(streamID uint32) (http2streamState, *http2stream) {
sc.serveG.check()
// http://tools.ietf.org/html/rfc7540#section-5.1
if st, ok := sc.streams[streamID]; ok {
return st.state, st
}
// "The first use of a new stream identifier implicitly closes all
// streams in the "idle" state that might have been initiated by
// that peer with a lower-valued stream identifier. For example, if
// a client sends a HEADERS frame on stream 7 without ever sending a
// frame on stream 5, then stream 5 transitions to the "closed"
// state when the first frame for stream 7 is sent or received."
if streamID%2 == 1 {
if streamID <= sc.maxClientStreamID {
return http2stateClosed, nil
}
} else {
if streamID <= sc.maxPushPromiseID {
return http2stateClosed, nil
}
}
return http2stateIdle, nil
}
// setConnState calls the net/http ConnState hook for this connection, if configured.
// Note that the net/http package does StateNew and StateClosed for us.
// There is currently no plan for StateHijacked or hijacking HTTP/2 connections.
func (sc *http2serverConn) setConnState(state ConnState) {
if sc.hs.ConnState != nil {
sc.hs.ConnState(sc.conn, state)
}
}
func (sc *http2serverConn) vlogf(format string, args ...interface{}) {
if http2VerboseLogs {
sc.logf(format, args...)
}
}
func (sc *http2serverConn) logf(format string, args ...interface{}) {
if lg := sc.hs.ErrorLog; lg != nil {
lg.Printf(format, args...)
} else {
log.Printf(format, args...)
}
}
// errno returns v's underlying uintptr, else 0.
//
// TODO: remove this helper function once http2 can use build
// tags. See comment in isClosedConnError.
func http2errno(v error) uintptr {
if rv := reflect.ValueOf(v); rv.Kind() == reflect.Uintptr {
return uintptr(rv.Uint())
}
return 0
}
// isClosedConnError reports whether err is an error from use of a closed
// network connection.
func http2isClosedConnError(err error) bool {
if err == nil {
return false
}
// TODO: remove this string search and be more like the Windows
// case below. That might involve modifying the standard library
// to return better error types.
str := err.Error()
if strings.Contains(str, "use of closed network connection") {
return true
}
// TODO(bradfitz): x/tools/cmd/bundle doesn't really support
// build tags, so I can't make an http2_windows.go file with
// Windows-specific stuff. Fix that and move this, once we
// have a way to bundle this into std's net/http somehow.
if runtime.GOOS == "windows" {
if oe, ok := err.(*net.OpError); ok && oe.Op == "read" {
if se, ok := oe.Err.(*os.SyscallError); ok && se.Syscall == "wsarecv" {
const WSAECONNABORTED = 10053
const WSAECONNRESET = 10054
if n := http2errno(se.Err); n == WSAECONNRESET || n == WSAECONNABORTED {
return true
}
}
}
}
return false
}
func (sc *http2serverConn) condlogf(err error, format string, args ...interface{}) {
if err == nil {
return
}
if err == io.EOF || err == io.ErrUnexpectedEOF || http2isClosedConnError(err) || err == http2errPrefaceTimeout {
// Boring, expected errors.
sc.vlogf(format, args...)
} else {
sc.logf(format, args...)
}
}
func (sc *http2serverConn) canonicalHeader(v string) string {
sc.serveG.check()
http2buildCommonHeaderMapsOnce()
cv, ok := http2commonCanonHeader[v]
if ok {
return cv
}
cv, ok = sc.canonHeader[v]
if ok {
return cv
}
if sc.canonHeader == nil {
sc.canonHeader = make(map[string]string)
}
cv = CanonicalHeaderKey(v)
sc.canonHeader[v] = cv
return cv
}
type http2readFrameResult struct {
f http2Frame // valid until readMore is called
err error
// readMore should be called once the consumer no longer needs or
// retains f. After readMore, f is invalid and more frames can be
// read.
readMore func()
}
// readFrames is the loop that reads incoming frames.
// It takes care to only read one frame at a time, blocking until the
// consumer is done with the frame.
// It's run on its own goroutine.
func (sc *http2serverConn) readFrames() {
gate := make(http2gate)
gateDone := gate.Done
for {
f, err := sc.framer.ReadFrame()
select {
case sc.readFrameCh <- http2readFrameResult{f, err, gateDone}:
case <-sc.doneServing:
return
}
select {
case <-gate:
case <-sc.doneServing:
return
}
if http2terminalReadFrameError(err) {
return
}
}
}
// frameWriteResult is the message passed from writeFrameAsync to the serve goroutine.
type http2frameWriteResult struct {
wr http2FrameWriteRequest // what was written (or attempted)
err error // result of the writeFrame call
}
// writeFrameAsync runs in its own goroutine and writes a single frame
// and then reports when it's done.
// At most one goroutine can be running writeFrameAsync at a time per
// serverConn.
func (sc *http2serverConn) writeFrameAsync(wr http2FrameWriteRequest) {
err := wr.write.writeFrame(sc)
sc.wroteFrameCh <- http2frameWriteResult{wr, err}
}
func (sc *http2serverConn) closeAllStreamsOnConnClose() {
sc.serveG.check()
for _, st := range sc.streams {
sc.closeStream(st, http2errClientDisconnected)
}
}
func (sc *http2serverConn) stopShutdownTimer() {
sc.serveG.check()
if t := sc.shutdownTimer; t != nil {
t.Stop()
}
}
func (sc *http2serverConn) notePanic() {
// Note: this is for serverConn.serve panicking, not http.Handler code.
if http2testHookOnPanicMu != nil {
http2testHookOnPanicMu.Lock()
defer http2testHookOnPanicMu.Unlock()
}
if http2testHookOnPanic != nil {
if e := recover(); e != nil {
if http2testHookOnPanic(sc, e) {
panic(e)
}
}
}
}
func (sc *http2serverConn) serve() {
sc.serveG.check()
defer sc.notePanic()
defer sc.conn.Close()
defer sc.closeAllStreamsOnConnClose()
defer sc.stopShutdownTimer()
defer close(sc.doneServing) // unblocks handlers trying to send
if http2VerboseLogs {
sc.vlogf("http2: server connection from %v on %p", sc.conn.RemoteAddr(), sc.hs)
}
sc.writeFrame(http2FrameWriteRequest{
write: http2writeSettings{
{http2SettingMaxFrameSize, sc.srv.maxReadFrameSize()},
{http2SettingMaxConcurrentStreams, sc.advMaxStreams},
{http2SettingMaxHeaderListSize, sc.maxHeaderListSize()},
{http2SettingInitialWindowSize, uint32(sc.srv.initialStreamRecvWindowSize())},
},
})
sc.unackedSettings++
// Each connection starts with intialWindowSize inflow tokens.
// If a higher value is configured, we add more tokens.
if diff := sc.srv.initialConnRecvWindowSize() - http2initialWindowSize; diff > 0 {
sc.sendWindowUpdate(nil, int(diff))
}
if err := sc.readPreface(); err != nil {
sc.condlogf(err, "http2: server: error reading preface from client %v: %v", sc.conn.RemoteAddr(), err)
return
}
// Now that we've got the preface, get us out of the
// "StateNew" state. We can't go directly to idle, though.
// Active means we read some data and anticipate a request. We'll
// do another Active when we get a HEADERS frame.
sc.setConnState(StateActive)
sc.setConnState(StateIdle)
if sc.srv.IdleTimeout != 0 {
sc.idleTimer = time.AfterFunc(sc.srv.IdleTimeout, sc.onIdleTimer)
defer sc.idleTimer.Stop()
}
go sc.readFrames() // closed by defer sc.conn.Close above
settingsTimer := time.AfterFunc(http2firstSettingsTimeout, sc.onSettingsTimer)
defer settingsTimer.Stop()
loopNum := 0
for {
loopNum++
select {
case wr := <-sc.wantWriteFrameCh:
if se, ok := wr.write.(http2StreamError); ok {
sc.resetStream(se)
break
}
sc.writeFrame(wr)
case res := <-sc.wroteFrameCh:
sc.wroteFrame(res)
case res := <-sc.readFrameCh:
if !sc.processFrameFromReader(res) {
return
}
res.readMore()
if settingsTimer != nil {
settingsTimer.Stop()
settingsTimer = nil
}
case m := <-sc.bodyReadCh:
sc.noteBodyRead(m.st, m.n)
case msg := <-sc.serveMsgCh:
switch v := msg.(type) {
case func(int):
v(loopNum) // for testing
case *http2serverMessage:
switch v {
case http2settingsTimerMsg:
sc.logf("timeout waiting for SETTINGS frames from %v", sc.conn.RemoteAddr())
return
case http2idleTimerMsg:
sc.vlogf("connection is idle")
sc.goAway(http2ErrCodeNo)
case http2shutdownTimerMsg:
sc.vlogf("GOAWAY close timer fired; closing conn from %v", sc.conn.RemoteAddr())
return
case http2gracefulShutdownMsg:
sc.startGracefulShutdownInternal()
default:
panic("unknown timer")
}
case *http2startPushRequest:
sc.startPush(v)
default:
panic(fmt.Sprintf("unexpected type %T", v))
}
}
// Start the shutdown timer after sending a GOAWAY. When sending GOAWAY
// with no error code (graceful shutdown), don't start the timer until
// all open streams have been completed.
sentGoAway := sc.inGoAway && !sc.needToSendGoAway && !sc.writingFrame
gracefulShutdownComplete := sc.goAwayCode == http2ErrCodeNo && sc.curOpenStreams() == 0
if sentGoAway && sc.shutdownTimer == nil && (sc.goAwayCode != http2ErrCodeNo || gracefulShutdownComplete) {
sc.shutDownIn(http2goAwayTimeout)
}
}
}
func (sc *http2serverConn) awaitGracefulShutdown(sharedCh <-chan struct{}, privateCh chan struct{}) {
select {
case <-sc.doneServing:
case <-sharedCh:
close(privateCh)
}
}
type http2serverMessage int
// Message values sent to serveMsgCh.
var (
http2settingsTimerMsg = new(http2serverMessage)
http2idleTimerMsg = new(http2serverMessage)
http2shutdownTimerMsg = new(http2serverMessage)
http2gracefulShutdownMsg = new(http2serverMessage)
)
func (sc *http2serverConn) onSettingsTimer() { sc.sendServeMsg(http2settingsTimerMsg) }
func (sc *http2serverConn) onIdleTimer() { sc.sendServeMsg(http2idleTimerMsg) }
func (sc *http2serverConn) onShutdownTimer() { sc.sendServeMsg(http2shutdownTimerMsg) }
func (sc *http2serverConn) sendServeMsg(msg interface{}) {
sc.serveG.checkNotOn() // NOT
select {
case sc.serveMsgCh <- msg:
case <-sc.doneServing:
}
}
var http2errPrefaceTimeout = errors.New("timeout waiting for client preface")
// readPreface reads the ClientPreface greeting from the peer or
// returns errPrefaceTimeout on timeout, or an error if the greeting
// is invalid.
func (sc *http2serverConn) readPreface() error {
errc := make(chan error, 1)
go func() {
// Read the client preface
buf := make([]byte, len(http2ClientPreface))
if _, err := io.ReadFull(sc.conn, buf); err != nil {
errc <- err
} else if !bytes.Equal(buf, http2clientPreface) {
errc <- fmt.Errorf("bogus greeting %q", buf)
} else {
errc <- nil
}
}()
timer := time.NewTimer(http2prefaceTimeout) // TODO: configurable on *Server?
defer timer.Stop()
select {
case <-timer.C:
return http2errPrefaceTimeout
case err := <-errc:
if err == nil {
if http2VerboseLogs {
sc.vlogf("http2: server: client %v said hello", sc.conn.RemoteAddr())
}
}
return err
}
}
var http2errChanPool = sync.Pool{
New: func() interface{} { return make(chan error, 1) },
}
var http2writeDataPool = sync.Pool{
New: func() interface{} { return new(http2writeData) },
}
// writeDataFromHandler writes DATA response frames from a handler on
// the given stream.
func (sc *http2serverConn) writeDataFromHandler(stream *http2stream, data []byte, endStream bool) error {
ch := http2errChanPool.Get().(chan error)
writeArg := http2writeDataPool.Get().(*http2writeData)
*writeArg = http2writeData{stream.id, data, endStream}
err := sc.writeFrameFromHandler(http2FrameWriteRequest{
write: writeArg,
stream: stream,
done: ch,
})
if err != nil {
return err
}
var frameWriteDone bool // the frame write is done (successfully or not)
select {
case err = <-ch:
frameWriteDone = true
case <-sc.doneServing:
return http2errClientDisconnected
case <-stream.cw:
// If both ch and stream.cw were ready (as might
// happen on the final Write after an http.Handler
// ends), prefer the write result. Otherwise this
// might just be us successfully closing the stream.
// The writeFrameAsync and serve goroutines guarantee
// that the ch send will happen before the stream.cw
// close.
select {
case err = <-ch:
frameWriteDone = true
default:
return http2errStreamClosed
}
}
http2errChanPool.Put(ch)
if frameWriteDone {
http2writeDataPool.Put(writeArg)
}
return err
}
// writeFrameFromHandler sends wr to sc.wantWriteFrameCh, but aborts
// if the connection has gone away.
//
// This must not be run from the serve goroutine itself, else it might
// deadlock writing to sc.wantWriteFrameCh (which is only mildly
// buffered and is read by serve itself). If you're on the serve
// goroutine, call writeFrame instead.
func (sc *http2serverConn) writeFrameFromHandler(wr http2FrameWriteRequest) error {
sc.serveG.checkNotOn() // NOT
select {
case sc.wantWriteFrameCh <- wr:
return nil
case <-sc.doneServing:
// Serve loop is gone.
// Client has closed their connection to the server.
return http2errClientDisconnected
}
}
// writeFrame schedules a frame to write and sends it if there's nothing
// already being written.
//
// There is no pushback here (the serve goroutine never blocks). It's
// the http.Handlers that block, waiting for their previous frames to
// make it onto the wire
//
// If you're not on the serve goroutine, use writeFrameFromHandler instead.
func (sc *http2serverConn) writeFrame(wr http2FrameWriteRequest) {
sc.serveG.check()
// If true, wr will not be written and wr.done will not be signaled.
var ignoreWrite bool
// We are not allowed to write frames on closed streams. RFC 7540 Section
// 5.1.1 says: "An endpoint MUST NOT send frames other than PRIORITY on
// a closed stream." Our server never sends PRIORITY, so that exception
// does not apply.
//
// The serverConn might close an open stream while the stream's handler
// is still running. For example, the server might close a stream when it
// receives bad data from the client. If this happens, the handler might
// attempt to write a frame after the stream has been closed (since the
// handler hasn't yet been notified of the close). In this case, we simply
// ignore the frame. The handler will notice that the stream is closed when
// it waits for the frame to be written.
//
// As an exception to this rule, we allow sending RST_STREAM after close.
// This allows us to immediately reject new streams without tracking any
// state for those streams (except for the queued RST_STREAM frame). This
// may result in duplicate RST_STREAMs in some cases, but the client should
// ignore those.
if wr.StreamID() != 0 {
_, isReset := wr.write.(http2StreamError)
if state, _ := sc.state(wr.StreamID()); state == http2stateClosed && !isReset {
ignoreWrite = true
}
}
// Don't send a 100-continue response if we've already sent headers.
// See golang.org/issue/14030.
switch wr.write.(type) {
case *http2writeResHeaders:
wr.stream.wroteHeaders = true
case http2write100ContinueHeadersFrame:
if wr.stream.wroteHeaders {
// We do not need to notify wr.done because this frame is
// never written with wr.done != nil.
if wr.done != nil {
panic("wr.done != nil for write100ContinueHeadersFrame")
}
ignoreWrite = true
}
}
if !ignoreWrite {
sc.writeSched.Push(wr)
}
sc.scheduleFrameWrite()
}
// startFrameWrite starts a goroutine to write wr (in a separate
// goroutine since that might block on the network), and updates the
// serve goroutine's state about the world, updated from info in wr.
func (sc *http2serverConn) startFrameWrite(wr http2FrameWriteRequest) {
sc.serveG.check()
if sc.writingFrame {
panic("internal error: can only be writing one frame at a time")
}
st := wr.stream
if st != nil {
switch st.state {
case http2stateHalfClosedLocal:
switch wr.write.(type) {
case http2StreamError, http2handlerPanicRST, http2writeWindowUpdate:
// RFC 7540 Section 5.1 allows sending RST_STREAM, PRIORITY, and WINDOW_UPDATE
// in this state. (We never send PRIORITY from the server, so that is not checked.)
default:
panic(fmt.Sprintf("internal error: attempt to send frame on a half-closed-local stream: %v", wr))
}
case http2stateClosed:
panic(fmt.Sprintf("internal error: attempt to send frame on a closed stream: %v", wr))
}
}
if wpp, ok := wr.write.(*http2writePushPromise); ok {
var err error
wpp.promisedID, err = wpp.allocatePromisedID()
if err != nil {
sc.writingFrameAsync = false
wr.replyToWriter(err)
return
}
}
sc.writingFrame = true
sc.needsFrameFlush = true
if wr.write.staysWithinBuffer(sc.bw.Available()) {
sc.writingFrameAsync = false
err := wr.write.writeFrame(sc)
sc.wroteFrame(http2frameWriteResult{wr, err})
} else {
sc.writingFrameAsync = true
go sc.writeFrameAsync(wr)
}
}
// errHandlerPanicked is the error given to any callers blocked in a read from
// Request.Body when the main goroutine panics. Since most handlers read in the
// main ServeHTTP goroutine, this will show up rarely.
var http2errHandlerPanicked = errors.New("http2: handler panicked")
// wroteFrame is called on the serve goroutine with the result of
// whatever happened on writeFrameAsync.
func (sc *http2serverConn) wroteFrame(res http2frameWriteResult) {
sc.serveG.check()
if !sc.writingFrame {
panic("internal error: expected to be already writing a frame")
}
sc.writingFrame = false
sc.writingFrameAsync = false
wr := res.wr
if http2writeEndsStream(wr.write) {
st := wr.stream
if st == nil {
panic("internal error: expecting non-nil stream")
}
switch st.state {
case http2stateOpen:
// Here we would go to stateHalfClosedLocal in
// theory, but since our handler is done and
// the net/http package provides no mechanism
// for closing a ResponseWriter while still
// reading data (see possible TODO at top of
// this file), we go into closed state here
// anyway, after telling the peer we're
// hanging up on them. We'll transition to
// stateClosed after the RST_STREAM frame is
// written.
st.state = http2stateHalfClosedLocal
// Section 8.1: a server MAY request that the client abort
// transmission of a request without error by sending a
// RST_STREAM with an error code of NO_ERROR after sending
// a complete response.
sc.resetStream(http2streamError(st.id, http2ErrCodeNo))
case http2stateHalfClosedRemote:
sc.closeStream(st, http2errHandlerComplete)
}
} else {
switch v := wr.write.(type) {
case http2StreamError:
// st may be unknown if the RST_STREAM was generated to reject bad input.
if st, ok := sc.streams[v.StreamID]; ok {
sc.closeStream(st, v)
}
case http2handlerPanicRST:
sc.closeStream(wr.stream, http2errHandlerPanicked)
}
}
// Reply (if requested) to unblock the ServeHTTP goroutine.
wr.replyToWriter(res.err)
sc.scheduleFrameWrite()
}
// scheduleFrameWrite tickles the frame writing scheduler.
//
// If a frame is already being written, nothing happens. This will be called again
// when the frame is done being written.
//
// If a frame isn't being written we need to send one, the best frame
// to send is selected, preferring first things that aren't
// stream-specific (e.g. ACKing settings), and then finding the
// highest priority stream.
//
// If a frame isn't being written and there's nothing else to send, we
// flush the write buffer.
func (sc *http2serverConn) scheduleFrameWrite() {
sc.serveG.check()
if sc.writingFrame || sc.inFrameScheduleLoop {
return
}
sc.inFrameScheduleLoop = true
for !sc.writingFrameAsync {
if sc.needToSendGoAway {
sc.needToSendGoAway = false
sc.startFrameWrite(http2FrameWriteRequest{
write: &http2writeGoAway{
maxStreamID: sc.maxClientStreamID,
code: sc.goAwayCode,
},
})
continue
}
if sc.needToSendSettingsAck {
sc.needToSendSettingsAck = false
sc.startFrameWrite(http2FrameWriteRequest{write: http2writeSettingsAck{}})
continue
}
if !sc.inGoAway || sc.goAwayCode == http2ErrCodeNo {
if wr, ok := sc.writeSched.Pop(); ok {
sc.startFrameWrite(wr)
continue
}
}
if sc.needsFrameFlush {
sc.startFrameWrite(http2FrameWriteRequest{write: http2flushFrameWriter{}})
sc.needsFrameFlush = false // after startFrameWrite, since it sets this true
continue
}
break
}
sc.inFrameScheduleLoop = false
}
// startGracefulShutdown gracefully shuts down a connection. This
// sends GOAWAY with ErrCodeNo to tell the client we're gracefully
// shutting down. The connection isn't closed until all current
// streams are done.
//
// startGracefulShutdown returns immediately; it does not wait until
// the connection has shut down.
func (sc *http2serverConn) startGracefulShutdown() {
sc.serveG.checkNotOn() // NOT
sc.shutdownOnce.Do(func() { sc.sendServeMsg(http2gracefulShutdownMsg) })
}
// After sending GOAWAY, the connection will close after goAwayTimeout.
// If we close the connection immediately after sending GOAWAY, there may
// be unsent data in our kernel receive buffer, which will cause the kernel
// to send a TCP RST on close() instead of a FIN. This RST will abort the
// connection immediately, whether or not the client had received the GOAWAY.
//
// Ideally we should delay for at least 1 RTT + epsilon so the client has
// a chance to read the GOAWAY and stop sending messages. Measuring RTT
// is hard, so we approximate with 1 second. See golang.org/issue/18701.
//
// This is a var so it can be shorter in tests, where all requests uses the
// loopback interface making the expected RTT very small.
//
// TODO: configurable?
var http2goAwayTimeout = 1 * time.Second
func (sc *http2serverConn) startGracefulShutdownInternal() {
sc.goAway(http2ErrCodeNo)
}
func (sc *http2serverConn) goAway(code http2ErrCode) {
sc.serveG.check()
if sc.inGoAway {
return
}
sc.inGoAway = true
sc.needToSendGoAway = true
sc.goAwayCode = code
sc.scheduleFrameWrite()
}
func (sc *http2serverConn) shutDownIn(d time.Duration) {
sc.serveG.check()
sc.shutdownTimer = time.AfterFunc(d, sc.onShutdownTimer)
}
func (sc *http2serverConn) resetStream(se http2StreamError) {
sc.serveG.check()
sc.writeFrame(http2FrameWriteRequest{write: se})
if st, ok := sc.streams[se.StreamID]; ok {
st.resetQueued = true
}
}
// processFrameFromReader processes the serve loop's read from readFrameCh from the
// frame-reading goroutine.
// processFrameFromReader returns whether the connection should be kept open.
func (sc *http2serverConn) processFrameFromReader(res http2readFrameResult) bool {
sc.serveG.check()
err := res.err
if err != nil {
if err == http2ErrFrameTooLarge {
sc.goAway(http2ErrCodeFrameSize)
return true // goAway will close the loop
}
clientGone := err == io.EOF || err == io.ErrUnexpectedEOF || http2isClosedConnError(err)
if clientGone {
// TODO: could we also get into this state if
// the peer does a half close
// (e.g. CloseWrite) because they're done
// sending frames but they're still wanting
// our open replies? Investigate.
// TODO: add CloseWrite to crypto/tls.Conn first
// so we have a way to test this? I suppose
// just for testing we could have a non-TLS mode.
return false
}
} else {
f := res.f
if http2VerboseLogs {
sc.vlogf("http2: server read frame %v", http2summarizeFrame(f))
}
err = sc.processFrame(f)
if err == nil {
return true
}
}
switch ev := err.(type) {
case http2StreamError:
sc.resetStream(ev)
return true
case http2goAwayFlowError:
sc.goAway(http2ErrCodeFlowControl)
return true
case http2ConnectionError:
sc.logf("http2: server connection error from %v: %v", sc.conn.RemoteAddr(), ev)
sc.goAway(http2ErrCode(ev))
return true // goAway will handle shutdown
default:
if res.err != nil {
sc.vlogf("http2: server closing client connection; error reading frame from client %s: %v", sc.conn.RemoteAddr(), err)
} else {
sc.logf("http2: server closing client connection: %v", err)
}
return false
}
}
func (sc *http2serverConn) processFrame(f http2Frame) error {
sc.serveG.check()
// First frame received must be SETTINGS.
if !sc.sawFirstSettings {
if _, ok := f.(*http2SettingsFrame); !ok {
return http2ConnectionError(http2ErrCodeProtocol)
}
sc.sawFirstSettings = true
}
switch f := f.(type) {
case *http2SettingsFrame:
return sc.processSettings(f)
case *http2MetaHeadersFrame:
return sc.processHeaders(f)
case *http2WindowUpdateFrame:
return sc.processWindowUpdate(f)
case *http2PingFrame:
return sc.processPing(f)
case *http2DataFrame:
return sc.processData(f)
case *http2RSTStreamFrame:
return sc.processResetStream(f)
case *http2PriorityFrame:
return sc.processPriority(f)
case *http2GoAwayFrame:
return sc.processGoAway(f)
case *http2PushPromiseFrame:
// A client cannot push. Thus, servers MUST treat the receipt of a PUSH_PROMISE
// frame as a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
return http2ConnectionError(http2ErrCodeProtocol)
default:
sc.vlogf("http2: server ignoring frame: %v", f.Header())
return nil
}
}
func (sc *http2serverConn) processPing(f *http2PingFrame) error {
sc.serveG.check()
if f.IsAck() {
// 6.7 PING: " An endpoint MUST NOT respond to PING frames
// containing this flag."
return nil
}
if f.StreamID != 0 {
// "PING frames are not associated with any individual
// stream. If a PING frame is received with a stream
// identifier field value other than 0x0, the recipient MUST
// respond with a connection error (Section 5.4.1) of type
// PROTOCOL_ERROR."
return http2ConnectionError(http2ErrCodeProtocol)
}
if sc.inGoAway && sc.goAwayCode != http2ErrCodeNo {
return nil
}
sc.writeFrame(http2FrameWriteRequest{write: http2writePingAck{f}})
return nil
}
func (sc *http2serverConn) processWindowUpdate(f *http2WindowUpdateFrame) error {
sc.serveG.check()
switch {
case f.StreamID != 0: // stream-level flow control
state, st := sc.state(f.StreamID)
if state == http2stateIdle {
// Section 5.1: "Receiving any frame other than HEADERS
// or PRIORITY on a stream in this state MUST be
// treated as a connection error (Section 5.4.1) of
// type PROTOCOL_ERROR."
return http2ConnectionError(http2ErrCodeProtocol)
}
if st == nil {
// "WINDOW_UPDATE can be sent by a peer that has sent a
// frame bearing the END_STREAM flag. This means that a
// receiver could receive a WINDOW_UPDATE frame on a "half
// closed (remote)" or "closed" stream. A receiver MUST
// NOT treat this as an error, see Section 5.1."
return nil
}
if !st.flow.add(int32(f.Increment)) {
return http2streamError(f.StreamID, http2ErrCodeFlowControl)
}
default: // connection-level flow control
if !sc.flow.add(int32(f.Increment)) {
return http2goAwayFlowError{}
}
}
sc.scheduleFrameWrite()
return nil
}
func (sc *http2serverConn) processResetStream(f *http2RSTStreamFrame) error {
sc.serveG.check()
state, st := sc.state(f.StreamID)
if state == http2stateIdle {
// 6.4 "RST_STREAM frames MUST NOT be sent for a
// stream in the "idle" state. If a RST_STREAM frame
// identifying an idle stream is received, the
// recipient MUST treat this as a connection error
// (Section 5.4.1) of type PROTOCOL_ERROR.
return http2ConnectionError(http2ErrCodeProtocol)
}
if st != nil {
st.cancelCtx()
sc.closeStream(st, http2streamError(f.StreamID, f.ErrCode))
}
return nil
}
func (sc *http2serverConn) closeStream(st *http2stream, err error) {
sc.serveG.check()
if st.state == http2stateIdle || st.state == http2stateClosed {
panic(fmt.Sprintf("invariant; can't close stream in state %v", st.state))
}
st.state = http2stateClosed
if st.writeDeadline != nil {
st.writeDeadline.Stop()
}
if st.isPushed() {
sc.curPushedStreams--
} else {
sc.curClientStreams--
}
delete(sc.streams, st.id)
if len(sc.streams) == 0 {
sc.setConnState(StateIdle)
if sc.srv.IdleTimeout != 0 {
sc.idleTimer.Reset(sc.srv.IdleTimeout)
}
if http2h1ServerKeepAlivesDisabled(sc.hs) {
sc.startGracefulShutdownInternal()
}
}
if p := st.body; p != nil {
// Return any buffered unread bytes worth of conn-level flow control.
// See golang.org/issue/16481
sc.sendWindowUpdate(nil, p.Len())
p.CloseWithError(err)
}
st.cw.Close() // signals Handler's CloseNotifier, unblocks writes, etc
sc.writeSched.CloseStream(st.id)
}
func (sc *http2serverConn) processSettings(f *http2SettingsFrame) error {
sc.serveG.check()
if f.IsAck() {
sc.unackedSettings--
if sc.unackedSettings < 0 {
// Why is the peer ACKing settings we never sent?
// The spec doesn't mention this case, but
// hang up on them anyway.
return http2ConnectionError(http2ErrCodeProtocol)
}
return nil
}
if f.NumSettings() > 100 || f.HasDuplicates() {
// This isn't actually in the spec, but hang up on
// suspiciously large settings frames or those with
// duplicate entries.
return http2ConnectionError(http2ErrCodeProtocol)
}
if err := f.ForeachSetting(sc.processSetting); err != nil {
return err
}
sc.needToSendSettingsAck = true
sc.scheduleFrameWrite()
return nil
}
func (sc *http2serverConn) processSetting(s http2Setting) error {
sc.serveG.check()
if err := s.Valid(); err != nil {
return err
}
if http2VerboseLogs {
sc.vlogf("http2: server processing setting %v", s)
}
switch s.ID {
case http2SettingHeaderTableSize:
sc.headerTableSize = s.Val
sc.hpackEncoder.SetMaxDynamicTableSize(s.Val)
case http2SettingEnablePush:
sc.pushEnabled = s.Val != 0
case http2SettingMaxConcurrentStreams:
sc.clientMaxStreams = s.Val
case http2SettingInitialWindowSize:
return sc.processSettingInitialWindowSize(s.Val)
case http2SettingMaxFrameSize:
sc.maxFrameSize = int32(s.Val) // the maximum valid s.Val is < 2^31
case http2SettingMaxHeaderListSize:
sc.peerMaxHeaderListSize = s.Val
default:
// Unknown setting: "An endpoint that receives a SETTINGS
// frame with any unknown or unsupported identifier MUST
// ignore that setting."
if http2VerboseLogs {
sc.vlogf("http2: server ignoring unknown setting %v", s)
}
}
return nil
}
func (sc *http2serverConn) processSettingInitialWindowSize(val uint32) error {
sc.serveG.check()
// Note: val already validated to be within range by
// processSetting's Valid call.
// "A SETTINGS frame can alter the initial flow control window
// size for all current streams. When the value of
// SETTINGS_INITIAL_WINDOW_SIZE changes, a receiver MUST
// adjust the size of all stream flow control windows that it
// maintains by the difference between the new value and the
// old value."
old := sc.initialStreamSendWindowSize
sc.initialStreamSendWindowSize = int32(val)
growth := int32(val) - old // may be negative
for _, st := range sc.streams {
if !st.flow.add(growth) {
// 6.9.2 Initial Flow Control Window Size
// "An endpoint MUST treat a change to
// SETTINGS_INITIAL_WINDOW_SIZE that causes any flow
// control window to exceed the maximum size as a
// connection error (Section 5.4.1) of type
// FLOW_CONTROL_ERROR."
return http2ConnectionError(http2ErrCodeFlowControl)
}
}
return nil
}
func (sc *http2serverConn) processData(f *http2DataFrame) error {
sc.serveG.check()
if sc.inGoAway && sc.goAwayCode != http2ErrCodeNo {
return nil
}
data := f.Data()
// "If a DATA frame is received whose stream is not in "open"
// or "half closed (local)" state, the recipient MUST respond
// with a stream error (Section 5.4.2) of type STREAM_CLOSED."
id := f.Header().StreamID
state, st := sc.state(id)
if id == 0 || state == http2stateIdle {
// Section 5.1: "Receiving any frame other than HEADERS
// or PRIORITY on a stream in this state MUST be
// treated as a connection error (Section 5.4.1) of
// type PROTOCOL_ERROR."
return http2ConnectionError(http2ErrCodeProtocol)
}
if st == nil || state != http2stateOpen || st.gotTrailerHeader || st.resetQueued {
// This includes sending a RST_STREAM if the stream is
// in stateHalfClosedLocal (which currently means that
// the http.Handler returned, so it's done reading &
// done writing). Try to stop the client from sending
// more DATA.
// But still enforce their connection-level flow control,
// and return any flow control bytes since we're not going
// to consume them.
if sc.inflow.available() < int32(f.Length) {
return http2streamError(id, http2ErrCodeFlowControl)
}
// Deduct the flow control from inflow, since we're
// going to immediately add it back in
// sendWindowUpdate, which also schedules sending the
// frames.
sc.inflow.take(int32(f.Length))
sc.sendWindowUpdate(nil, int(f.Length)) // conn-level
if st != nil && st.resetQueued {
// Already have a stream error in flight. Don't send another.
return nil
}
return http2streamError(id, http2ErrCodeStreamClosed)
}
if st.body == nil {
panic("internal error: should have a body in this state")
}
// Sender sending more than they'd declared?
if st.declBodyBytes != -1 && st.bodyBytes+int64(len(data)) > st.declBodyBytes {
st.body.CloseWithError(fmt.Errorf("sender tried to send more than declared Content-Length of %d bytes", st.declBodyBytes))
// RFC 7540, sec 8.1.2.6: A request or response is also malformed if the
// value of a content-length header field does not equal the sum of the
// DATA frame payload lengths that form the body.
return http2streamError(id, http2ErrCodeProtocol)
}
if f.Length > 0 {
// Check whether the client has flow control quota.
if st.inflow.available() < int32(f.Length) {
return http2streamError(id, http2ErrCodeFlowControl)
}
st.inflow.take(int32(f.Length))
if len(data) > 0 {
wrote, err := st.body.Write(data)
if err != nil {
return http2streamError(id, http2ErrCodeStreamClosed)
}
if wrote != len(data) {
panic("internal error: bad Writer")
}
st.bodyBytes += int64(len(data))
}
// Return any padded flow control now, since we won't
// refund it later on body reads.
if pad := int32(f.Length) - int32(len(data)); pad > 0 {
sc.sendWindowUpdate32(nil, pad)
sc.sendWindowUpdate32(st, pad)
}
}
if f.StreamEnded() {
st.endStream()
}
return nil
}
func (sc *http2serverConn) processGoAway(f *http2GoAwayFrame) error {
sc.serveG.check()
if f.ErrCode != http2ErrCodeNo {
sc.logf("http2: received GOAWAY %+v, starting graceful shutdown", f)
} else {
sc.vlogf("http2: received GOAWAY %+v, starting graceful shutdown", f)
}
sc.startGracefulShutdownInternal()
// http://tools.ietf.org/html/rfc7540#section-6.8
// We should not create any new streams, which means we should disable push.
sc.pushEnabled = false
return nil
}
// isPushed reports whether the stream is server-initiated.
func (st *http2stream) isPushed() bool {
return st.id%2 == 0
}
// endStream closes a Request.Body's pipe. It is called when a DATA
// frame says a request body is over (or after trailers).
func (st *http2stream) endStream() {
sc := st.sc
sc.serveG.check()
if st.declBodyBytes != -1 && st.declBodyBytes != st.bodyBytes {
st.body.CloseWithError(fmt.Errorf("request declared a Content-Length of %d but only wrote %d bytes",
st.declBodyBytes, st.bodyBytes))
} else {
st.body.closeWithErrorAndCode(io.EOF, st.copyTrailersToHandlerRequest)
st.body.CloseWithError(io.EOF)
}
st.state = http2stateHalfClosedRemote
}
// copyTrailersToHandlerRequest is run in the Handler's goroutine in
// its Request.Body.Read just before it gets io.EOF.
func (st *http2stream) copyTrailersToHandlerRequest() {
for k, vv := range st.trailer {
if _, ok := st.reqTrailer[k]; ok {
// Only copy it over it was pre-declared.
st.reqTrailer[k] = vv
}
}
}
// onWriteTimeout is run on its own goroutine (from time.AfterFunc)
// when the stream's WriteTimeout has fired.
func (st *http2stream) onWriteTimeout() {
st.sc.writeFrameFromHandler(http2FrameWriteRequest{write: http2streamError(st.id, http2ErrCodeInternal)})
}
func (sc *http2serverConn) processHeaders(f *http2MetaHeadersFrame) error {
sc.serveG.check()
id := f.StreamID
if sc.inGoAway {
// Ignore.
return nil
}
// http://tools.ietf.org/html/rfc7540#section-5.1.1
// Streams initiated by a client MUST use odd-numbered stream
// identifiers. [...] An endpoint that receives an unexpected
// stream identifier MUST respond with a connection error
// (Section 5.4.1) of type PROTOCOL_ERROR.
if id%2 != 1 {
return http2ConnectionError(http2ErrCodeProtocol)
}
// A HEADERS frame can be used to create a new stream or
// send a trailer for an open one. If we already have a stream
// open, let it process its own HEADERS frame (trailers at this
// point, if it's valid).
if st := sc.streams[f.StreamID]; st != nil {
if st.resetQueued {
// We're sending RST_STREAM to close the stream, so don't bother
// processing this frame.
return nil
}
// RFC 7540, sec 5.1: If an endpoint receives additional frames, other than
// WINDOW_UPDATE, PRIORITY, or RST_STREAM, for a stream that is in
// this state, it MUST respond with a stream error (Section 5.4.2) of
// type STREAM_CLOSED.
if st.state == http2stateHalfClosedRemote {
return http2streamError(id, http2ErrCodeStreamClosed)
}
return st.processTrailerHeaders(f)
}
// [...] The identifier of a newly established stream MUST be
// numerically greater than all streams that the initiating
// endpoint has opened or reserved. [...] An endpoint that
// receives an unexpected stream identifier MUST respond with
// a connection error (Section 5.4.1) of type PROTOCOL_ERROR.
if id <= sc.maxClientStreamID {
return http2ConnectionError(http2ErrCodeProtocol)
}
sc.maxClientStreamID = id
if sc.idleTimer != nil {
sc.idleTimer.Stop()
}
// http://tools.ietf.org/html/rfc7540#section-5.1.2
// [...] Endpoints MUST NOT exceed the limit set by their peer. An
// endpoint that receives a HEADERS frame that causes their
// advertised concurrent stream limit to be exceeded MUST treat
// this as a stream error (Section 5.4.2) of type PROTOCOL_ERROR
// or REFUSED_STREAM.
if sc.curClientStreams+1 > sc.advMaxStreams {
if sc.unackedSettings == 0 {
// They should know better.
return http2streamError(id, http2ErrCodeProtocol)
}
// Assume it's a network race, where they just haven't
// received our last SETTINGS update. But actually
// this can't happen yet, because we don't yet provide
// a way for users to adjust server parameters at
// runtime.
return http2streamError(id, http2ErrCodeRefusedStream)
}
initialState := http2stateOpen
if f.StreamEnded() {
initialState = http2stateHalfClosedRemote
}
st := sc.newStream(id, 0, initialState)
if f.HasPriority() {
if err := http2checkPriority(f.StreamID, f.Priority); err != nil {
return err
}
sc.writeSched.AdjustStream(st.id, f.Priority)
}
rw, req, err := sc.newWriterAndRequest(st, f)
if err != nil {
return err
}
st.reqTrailer = req.Trailer
if st.reqTrailer != nil {
st.trailer = make(Header)
}
st.body = req.Body.(*http2requestBody).pipe // may be nil
st.declBodyBytes = req.ContentLength
handler := sc.handler.ServeHTTP
if f.Truncated {
// Their header list was too long. Send a 431 error.
handler = http2handleHeaderListTooLong
} else if err := http2checkValidHTTP2RequestHeaders(req.Header); err != nil {
handler = http2new400Handler(err)
}
// The net/http package sets the read deadline from the
// http.Server.ReadTimeout during the TLS handshake, but then
// passes the connection off to us with the deadline already
// set. Disarm it here after the request headers are read,
// similar to how the http1 server works. Here it's
// technically more like the http1 Server's ReadHeaderTimeout
// (in Go 1.8), though. That's a more sane option anyway.
if sc.hs.ReadTimeout != 0 {
sc.conn.SetReadDeadline(time.Time{})
}
go sc.runHandler(rw, req, handler)
return nil
}
func (st *http2stream) processTrailerHeaders(f *http2MetaHeadersFrame) error {
sc := st.sc
sc.serveG.check()
if st.gotTrailerHeader {
return http2ConnectionError(http2ErrCodeProtocol)
}
st.gotTrailerHeader = true
if !f.StreamEnded() {
return http2streamError(st.id, http2ErrCodeProtocol)
}
if len(f.PseudoFields()) > 0 {
return http2streamError(st.id, http2ErrCodeProtocol)
}
if st.trailer != nil {
for _, hf := range f.RegularFields() {
key := sc.canonicalHeader(hf.Name)
if !httpguts.ValidTrailerHeader(key) {
// TODO: send more details to the peer somehow. But http2 has
// no way to send debug data at a stream level. Discuss with
// HTTP folk.
return http2streamError(st.id, http2ErrCodeProtocol)
}
st.trailer[key] = append(st.trailer[key], hf.Value)
}
}
st.endStream()
return nil
}
func http2checkPriority(streamID uint32, p http2PriorityParam) error {
if streamID == p.StreamDep {
// Section 5.3.1: "A stream cannot depend on itself. An endpoint MUST treat
// this as a stream error (Section 5.4.2) of type PROTOCOL_ERROR."
// Section 5.3.3 says that a stream can depend on one of its dependencies,
// so it's only self-dependencies that are forbidden.
return http2streamError(streamID, http2ErrCodeProtocol)
}
return nil
}
func (sc *http2serverConn) processPriority(f *http2PriorityFrame) error {
if sc.inGoAway {
return nil
}
if err := http2checkPriority(f.StreamID, f.http2PriorityParam); err != nil {
return err
}
sc.writeSched.AdjustStream(f.StreamID, f.http2PriorityParam)
return nil
}
func (sc *http2serverConn) newStream(id, pusherID uint32, state http2streamState) *http2stream {
sc.serveG.check()
if id == 0 {
panic("internal error: cannot create stream with id 0")
}
ctx, cancelCtx := context.WithCancel(sc.baseCtx)
st := &http2stream{
sc: sc,
id: id,
state: state,
ctx: ctx,
cancelCtx: cancelCtx,
}
st.cw.Init()
st.flow.conn = &sc.flow // link to conn-level counter
st.flow.add(sc.initialStreamSendWindowSize)
st.inflow.conn = &sc.inflow // link to conn-level counter
st.inflow.add(sc.srv.initialStreamRecvWindowSize())
if sc.hs.WriteTimeout != 0 {
st.writeDeadline = time.AfterFunc(sc.hs.WriteTimeout, st.onWriteTimeout)
}
sc.streams[id] = st
sc.writeSched.OpenStream(st.id, http2OpenStreamOptions{PusherID: pusherID})
if st.isPushed() {
sc.curPushedStreams++
} else {
sc.curClientStreams++
}
if sc.curOpenStreams() == 1 {
sc.setConnState(StateActive)
}
return st
}
func (sc *http2serverConn) newWriterAndRequest(st *http2stream, f *http2MetaHeadersFrame) (*http2responseWriter, *Request, error) {
sc.serveG.check()
rp := http2requestParam{
method: f.PseudoValue("method"),
scheme: f.PseudoValue("scheme"),
authority: f.PseudoValue("authority"),
path: f.PseudoValue("path"),
}
isConnect := rp.method == "CONNECT"
if isConnect {
if rp.path != "" || rp.scheme != "" || rp.authority == "" {
return nil, nil, http2streamError(f.StreamID, http2ErrCodeProtocol)
}
} else if rp.method == "" || rp.path == "" || (rp.scheme != "https" && rp.scheme != "http") {
// See 8.1.2.6 Malformed Requests and Responses:
//
// Malformed requests or responses that are detected
// MUST be treated as a stream error (Section 5.4.2)
// of type PROTOCOL_ERROR."
//
// 8.1.2.3 Request Pseudo-Header Fields
// "All HTTP/2 requests MUST include exactly one valid
// value for the :method, :scheme, and :path
// pseudo-header fields"
return nil, nil, http2streamError(f.StreamID, http2ErrCodeProtocol)
}
bodyOpen := !f.StreamEnded()
if rp.method == "HEAD" && bodyOpen {
// HEAD requests can't have bodies
return nil, nil, http2streamError(f.StreamID, http2ErrCodeProtocol)
}
rp.header = make(Header)
for _, hf := range f.RegularFields() {
rp.header.Add(sc.canonicalHeader(hf.Name), hf.Value)
}
if rp.authority == "" {
rp.authority = rp.header.Get("Host")
}
rw, req, err := sc.newWriterAndRequestNoBody(st, rp)
if err != nil {
return nil, nil, err
}
if bodyOpen {
if vv, ok := rp.header["Content-Length"]; ok {
req.ContentLength, _ = strconv.ParseInt(vv[0], 10, 64)
} else {
req.ContentLength = -1
}
req.Body.(*http2requestBody).pipe = &http2pipe{
b: &http2dataBuffer{expected: req.ContentLength},
}
}
return rw, req, nil
}
type http2requestParam struct {
method string
scheme, authority, path string
header Header
}
func (sc *http2serverConn) newWriterAndRequestNoBody(st *http2stream, rp http2requestParam) (*http2responseWriter, *Request, error) {
sc.serveG.check()
var tlsState *tls.ConnectionState // nil if not scheme https
if rp.scheme == "https" {
tlsState = sc.tlsState
}
needsContinue := rp.header.Get("Expect") == "100-continue"
if needsContinue {
rp.header.Del("Expect")
}
// Merge Cookie headers into one "; "-delimited value.
if cookies := rp.header["Cookie"]; len(cookies) > 1 {
rp.header.Set("Cookie", strings.Join(cookies, "; "))
}
// Setup Trailers
var trailer Header
for _, v := range rp.header["Trailer"] {
for _, key := range strings.Split(v, ",") {
key = CanonicalHeaderKey(strings.TrimSpace(key))
switch key {
case "Transfer-Encoding", "Trailer", "Content-Length":
// Bogus. (copy of http1 rules)
// Ignore.
default:
if trailer == nil {
trailer = make(Header)
}
trailer[key] = nil
}
}
}
delete(rp.header, "Trailer")
var url_ *url.URL
var requestURI string
if rp.method == "CONNECT" {
url_ = &url.URL{Host: rp.authority}
requestURI = rp.authority // mimic HTTP/1 server behavior
} else {
var err error
url_, err = url.ParseRequestURI(rp.path)
if err != nil {
return nil, nil, http2streamError(st.id, http2ErrCodeProtocol)
}
requestURI = rp.path
}
body := &http2requestBody{
conn: sc,
stream: st,
needsContinue: needsContinue,
}
req := &Request{
Method: rp.method,
URL: url_,
RemoteAddr: sc.remoteAddrStr,
Header: rp.header,
RequestURI: requestURI,
Proto: "HTTP/2.0",
ProtoMajor: 2,
ProtoMinor: 0,
TLS: tlsState,
Host: rp.authority,
Body: body,
Trailer: trailer,
}
req = req.WithContext(st.ctx)
rws := http2responseWriterStatePool.Get().(*http2responseWriterState)
bwSave := rws.bw
*rws = http2responseWriterState{} // zero all the fields
rws.conn = sc
rws.bw = bwSave
rws.bw.Reset(http2chunkWriter{rws})
rws.stream = st
rws.req = req
rws.body = body
rw := &http2responseWriter{rws: rws}
return rw, req, nil
}
// Run on its own goroutine.
func (sc *http2serverConn) runHandler(rw *http2responseWriter, req *Request, handler func(ResponseWriter, *Request)) {
didPanic := true
defer func() {
rw.rws.stream.cancelCtx()
if didPanic {
e := recover()
sc.writeFrameFromHandler(http2FrameWriteRequest{
write: http2handlerPanicRST{rw.rws.stream.id},
stream: rw.rws.stream,
})
// Same as net/http:
if e != nil && e != ErrAbortHandler {
const size = 64 << 10
buf := make([]byte, size)
buf = buf[:runtime.Stack(buf, false)]
sc.logf("http2: panic serving %v: %v\n%s", sc.conn.RemoteAddr(), e, buf)
}
return
}
rw.handlerDone()
}()
handler(rw, req)
didPanic = false
}
func http2handleHeaderListTooLong(w ResponseWriter, r *Request) {
// 10.5.1 Limits on Header Block Size:
// .. "A server that receives a larger header block than it is
// willing to handle can send an HTTP 431 (Request Header Fields Too
// Large) status code"
const statusRequestHeaderFieldsTooLarge = 431 // only in Go 1.6+
w.WriteHeader(statusRequestHeaderFieldsTooLarge)
io.WriteString(w, "<h1>HTTP Error 431</h1><p>Request Header Field(s) Too Large</p>")
}
// called from handler goroutines.
// h may be nil.
func (sc *http2serverConn) writeHeaders(st *http2stream, headerData *http2writeResHeaders) error {
sc.serveG.checkNotOn() // NOT on
var errc chan error
if headerData.h != nil {
// If there's a header map (which we don't own), so we have to block on
// waiting for this frame to be written, so an http.Flush mid-handler
// writes out the correct value of keys, before a handler later potentially
// mutates it.
errc = http2errChanPool.Get().(chan error)
}
if err := sc.writeFrameFromHandler(http2FrameWriteRequest{
write: headerData,
stream: st,
done: errc,
}); err != nil {
return err
}
if errc != nil {
select {
case err := <-errc:
http2errChanPool.Put(errc)
return err
case <-sc.doneServing:
return http2errClientDisconnected
case <-st.cw:
return http2errStreamClosed
}
}
return nil
}
// called from handler goroutines.
func (sc *http2serverConn) write100ContinueHeaders(st *http2stream) {
sc.writeFrameFromHandler(http2FrameWriteRequest{
write: http2write100ContinueHeadersFrame{st.id},
stream: st,
})
}
// A bodyReadMsg tells the server loop that the http.Handler read n
// bytes of the DATA from the client on the given stream.
type http2bodyReadMsg struct {
st *http2stream
n int
}
// called from handler goroutines.
// Notes that the handler for the given stream ID read n bytes of its body
// and schedules flow control tokens to be sent.
func (sc *http2serverConn) noteBodyReadFromHandler(st *http2stream, n int, err error) {
sc.serveG.checkNotOn() // NOT on
if n > 0 {
select {
case sc.bodyReadCh <- http2bodyReadMsg{st, n}:
case <-sc.doneServing:
}
}
}
func (sc *http2serverConn) noteBodyRead(st *http2stream, n int) {
sc.serveG.check()
sc.sendWindowUpdate(nil, n) // conn-level
if st.state != http2stateHalfClosedRemote && st.state != http2stateClosed {
// Don't send this WINDOW_UPDATE if the stream is closed
// remotely.
sc.sendWindowUpdate(st, n)
}
}
// st may be nil for conn-level
func (sc *http2serverConn) sendWindowUpdate(st *http2stream, n int) {
sc.serveG.check()
// "The legal range for the increment to the flow control
// window is 1 to 2^31-1 (2,147,483,647) octets."
// A Go Read call on 64-bit machines could in theory read
// a larger Read than this. Very unlikely, but we handle it here
// rather than elsewhere for now.
const maxUint31 = 1<<31 - 1
for n >= maxUint31 {
sc.sendWindowUpdate32(st, maxUint31)
n -= maxUint31
}
sc.sendWindowUpdate32(st, int32(n))
}
// st may be nil for conn-level
func (sc *http2serverConn) sendWindowUpdate32(st *http2stream, n int32) {
sc.serveG.check()
if n == 0 {
return
}
if n < 0 {
panic("negative update")
}
var streamID uint32
if st != nil {
streamID = st.id
}
sc.writeFrame(http2FrameWriteRequest{
write: http2writeWindowUpdate{streamID: streamID, n: uint32(n)},
stream: st,
})
var ok bool
if st == nil {
ok = sc.inflow.add(n)
} else {
ok = st.inflow.add(n)
}
if !ok {
panic("internal error; sent too many window updates without decrements?")
}
}
// requestBody is the Handler's Request.Body type.
// Read and Close may be called concurrently.
type http2requestBody struct {
stream *http2stream
conn *http2serverConn
closed bool // for use by Close only
sawEOF bool // for use by Read only
pipe *http2pipe // non-nil if we have a HTTP entity message body
needsContinue bool // need to send a 100-continue
}
func (b *http2requestBody) Close() error {
if b.pipe != nil && !b.closed {
b.pipe.BreakWithError(http2errClosedBody)
}
b.closed = true
return nil
}
func (b *http2requestBody) Read(p []byte) (n int, err error) {
if b.needsContinue {
b.needsContinue = false
b.conn.write100ContinueHeaders(b.stream)
}
if b.pipe == nil || b.sawEOF {
return 0, io.EOF
}
n, err = b.pipe.Read(p)
if err == io.EOF {
b.sawEOF = true
}
if b.conn == nil && http2inTests {
return
}
b.conn.noteBodyReadFromHandler(b.stream, n, err)
return
}
// responseWriter is the http.ResponseWriter implementation. It's
// intentionally small (1 pointer wide) to minimize garbage. The
// responseWriterState pointer inside is zeroed at the end of a
// request (in handlerDone) and calls on the responseWriter thereafter
// simply crash (caller's mistake), but the much larger responseWriterState
// and buffers are reused between multiple requests.
type http2responseWriter struct {
rws *http2responseWriterState
}
// Optional http.ResponseWriter interfaces implemented.
var (
_ CloseNotifier = (*http2responseWriter)(nil)
_ Flusher = (*http2responseWriter)(nil)
_ http2stringWriter = (*http2responseWriter)(nil)
)
type http2responseWriterState struct {
// immutable within a request:
stream *http2stream
req *Request
body *http2requestBody // to close at end of request, if DATA frames didn't
conn *http2serverConn
// TODO: adjust buffer writing sizes based on server config, frame size updates from peer, etc
bw *bufio.Writer // writing to a chunkWriter{this *responseWriterState}
// mutated by http.Handler goroutine:
handlerHeader Header // nil until called
snapHeader Header // snapshot of handlerHeader at WriteHeader time
trailers []string // set in writeChunk
status int // status code passed to WriteHeader
wroteHeader bool // WriteHeader called (explicitly or implicitly). Not necessarily sent to user yet.
sentHeader bool // have we sent the header frame?
handlerDone bool // handler has finished
dirty bool // a Write failed; don't reuse this responseWriterState
sentContentLen int64 // non-zero if handler set a Content-Length header
wroteBytes int64
closeNotifierMu sync.Mutex // guards closeNotifierCh
closeNotifierCh chan bool // nil until first used
}
type http2chunkWriter struct{ rws *http2responseWriterState }
func (cw http2chunkWriter) Write(p []byte) (n int, err error) { return cw.rws.writeChunk(p) }
func (rws *http2responseWriterState) hasTrailers() bool { return len(rws.trailers) != 0 }
// declareTrailer is called for each Trailer header when the
// response header is written. It notes that a header will need to be
// written in the trailers at the end of the response.
func (rws *http2responseWriterState) declareTrailer(k string) {
k = CanonicalHeaderKey(k)
if !httpguts.ValidTrailerHeader(k) {
// Forbidden by RFC 7230, section 4.1.2.
rws.conn.logf("ignoring invalid trailer %q", k)
return
}
if !http2strSliceContains(rws.trailers, k) {
rws.trailers = append(rws.trailers, k)
}
}
// writeChunk writes chunks from the bufio.Writer. But because
// bufio.Writer may bypass its chunking, sometimes p may be
// arbitrarily large.
//
// writeChunk is also responsible (on the first chunk) for sending the
// HEADER response.
func (rws *http2responseWriterState) writeChunk(p []byte) (n int, err error) {
if !rws.wroteHeader {
rws.writeHeader(200)
}
isHeadResp := rws.req.Method == "HEAD"
if !rws.sentHeader {
rws.sentHeader = true
var ctype, clen string
if clen = rws.snapHeader.Get("Content-Length"); clen != "" {
rws.snapHeader.Del("Content-Length")
clen64, err := strconv.ParseInt(clen, 10, 64)
if err == nil && clen64 >= 0 {
rws.sentContentLen = clen64
} else {
clen = ""
}
}
if clen == "" && rws.handlerDone && http2bodyAllowedForStatus(rws.status) && (len(p) > 0 || !isHeadResp) {
clen = strconv.Itoa(len(p))
}
_, hasContentType := rws.snapHeader["Content-Type"]
if !hasContentType && http2bodyAllowedForStatus(rws.status) && len(p) > 0 {
ctype = DetectContentType(p)
}
var date string
if _, ok := rws.snapHeader["Date"]; !ok {
// TODO(bradfitz): be faster here, like net/http? measure.
date = time.Now().UTC().Format(TimeFormat)
}
for _, v := range rws.snapHeader["Trailer"] {
http2foreachHeaderElement(v, rws.declareTrailer)
}
// "Connection" headers aren't allowed in HTTP/2 (RFC 7540, 8.1.2.2),
// but respect "Connection" == "close" to mean sending a GOAWAY and tearing
// down the TCP connection when idle, like we do for HTTP/1.
// TODO: remove more Connection-specific header fields here, in addition
// to "Connection".
if _, ok := rws.snapHeader["Connection"]; ok {
v := rws.snapHeader.Get("Connection")
delete(rws.snapHeader, "Connection")
if v == "close" {
rws.conn.startGracefulShutdown()
}
}
endStream := (rws.handlerDone && !rws.hasTrailers() && len(p) == 0) || isHeadResp
err = rws.conn.writeHeaders(rws.stream, &http2writeResHeaders{
streamID: rws.stream.id,
httpResCode: rws.status,
h: rws.snapHeader,
endStream: endStream,
contentType: ctype,
contentLength: clen,
date: date,
})
if err != nil {
rws.dirty = true
return 0, err
}
if endStream {
return 0, nil
}
}
if isHeadResp {
return len(p), nil
}
if len(p) == 0 && !rws.handlerDone {
return 0, nil
}
if rws.handlerDone {
rws.promoteUndeclaredTrailers()
}
endStream := rws.handlerDone && !rws.hasTrailers()
if len(p) > 0 || endStream {
// only send a 0 byte DATA frame if we're ending the stream.
if err := rws.conn.writeDataFromHandler(rws.stream, p, endStream); err != nil {
rws.dirty = true
return 0, err
}
}
if rws.handlerDone && rws.hasTrailers() {
err = rws.conn.writeHeaders(rws.stream, &http2writeResHeaders{
streamID: rws.stream.id,
h: rws.handlerHeader,
trailers: rws.trailers,
endStream: true,
})
if err != nil {
rws.dirty = true
}
return len(p), err
}
return len(p), nil
}
// TrailerPrefix is a magic prefix for ResponseWriter.Header map keys
// that, if present, signals that the map entry is actually for
// the response trailers, and not the response headers. The prefix
// is stripped after the ServeHTTP call finishes and the values are
// sent in the trailers.
//
// This mechanism is intended only for trailers that are not known
// prior to the headers being written. If the set of trailers is fixed
// or known before the header is written, the normal Go trailers mechanism
// is preferred:
// https://golang.org/pkg/net/http/#ResponseWriter
// https://golang.org/pkg/net/http/#example_ResponseWriter_trailers
const http2TrailerPrefix = "Trailer:"
// promoteUndeclaredTrailers permits http.Handlers to set trailers
// after the header has already been flushed. Because the Go
// ResponseWriter interface has no way to set Trailers (only the
// Header), and because we didn't want to expand the ResponseWriter
// interface, and because nobody used trailers, and because RFC 7230
// says you SHOULD (but not must) predeclare any trailers in the
// header, the official ResponseWriter rules said trailers in Go must
// be predeclared, and then we reuse the same ResponseWriter.Header()
// map to mean both Headers and Trailers. When it's time to write the
// Trailers, we pick out the fields of Headers that were declared as
// trailers. That worked for a while, until we found the first major
// user of Trailers in the wild: gRPC (using them only over http2),
// and gRPC libraries permit setting trailers mid-stream without
// predeclarnig them. So: change of plans. We still permit the old
// way, but we also permit this hack: if a Header() key begins with
// "Trailer:", the suffix of that key is a Trailer. Because ':' is an
// invalid token byte anyway, there is no ambiguity. (And it's already
// filtered out) It's mildly hacky, but not terrible.
//
// This method runs after the Handler is done and promotes any Header
// fields to be trailers.
func (rws *http2responseWriterState) promoteUndeclaredTrailers() {
for k, vv := range rws.handlerHeader {
if !strings.HasPrefix(k, http2TrailerPrefix) {
continue
}
trailerKey := strings.TrimPrefix(k, http2TrailerPrefix)
rws.declareTrailer(trailerKey)
rws.handlerHeader[CanonicalHeaderKey(trailerKey)] = vv
}
if len(rws.trailers) > 1 {
sorter := http2sorterPool.Get().(*http2sorter)
sorter.SortStrings(rws.trailers)
http2sorterPool.Put(sorter)
}
}
func (w *http2responseWriter) Flush() {
rws := w.rws
if rws == nil {
panic("Header called after Handler finished")
}
if rws.bw.Buffered() > 0 {
if err := rws.bw.Flush(); err != nil {
// Ignore the error. The frame writer already knows.
return
}
} else {
// The bufio.Writer won't call chunkWriter.Write
// (writeChunk with zero bytes, so we have to do it
// ourselves to force the HTTP response header and/or
// final DATA frame (with END_STREAM) to be sent.
rws.writeChunk(nil)
}
}
func (w *http2responseWriter) CloseNotify() <-chan bool {
rws := w.rws
if rws == nil {
panic("CloseNotify called after Handler finished")
}
rws.closeNotifierMu.Lock()
ch := rws.closeNotifierCh
if ch == nil {
ch = make(chan bool, 1)
rws.closeNotifierCh = ch
cw := rws.stream.cw
go func() {
cw.Wait() // wait for close
ch <- true
}()
}
rws.closeNotifierMu.Unlock()
return ch
}
func (w *http2responseWriter) Header() Header {
rws := w.rws
if rws == nil {
panic("Header called after Handler finished")
}
if rws.handlerHeader == nil {
rws.handlerHeader = make(Header)
}
return rws.handlerHeader
}
// checkWriteHeaderCode is a copy of net/http's checkWriteHeaderCode.
func http2checkWriteHeaderCode(code int) {
// Issue 22880: require valid WriteHeader status codes.
// For now we only enforce that it's three digits.
// In the future we might block things over 599 (600 and above aren't defined
// at http://httpwg.org/specs/rfc7231.html#status.codes)
// and we might block under 200 (once we have more mature 1xx support).
// But for now any three digits.
//
// We used to send "HTTP/1.1 000 0" on the wire in responses but there's
// no equivalent bogus thing we can realistically send in HTTP/2,
// so we'll consistently panic instead and help people find their bugs
// early. (We can't return an error from WriteHeader even if we wanted to.)
if code < 100 || code > 999 {
panic(fmt.Sprintf("invalid WriteHeader code %v", code))
}
}
func (w *http2responseWriter) WriteHeader(code int) {
rws := w.rws
if rws == nil {
panic("WriteHeader called after Handler finished")
}
rws.writeHeader(code)
}
func (rws *http2responseWriterState) writeHeader(code int) {
if !rws.wroteHeader {
http2checkWriteHeaderCode(code)
rws.wroteHeader = true
rws.status = code
if len(rws.handlerHeader) > 0 {
rws.snapHeader = http2cloneHeader(rws.handlerHeader)
}
}
}
func http2cloneHeader(h Header) Header {
h2 := make(Header, len(h))
for k, vv := range h {
vv2 := make([]string, len(vv))
copy(vv2, vv)
h2[k] = vv2
}
return h2
}
// The Life Of A Write is like this:
//
// * Handler calls w.Write or w.WriteString ->
// * -> rws.bw (*bufio.Writer) ->
// * (Handler might call Flush)
// * -> chunkWriter{rws}
// * -> responseWriterState.writeChunk(p []byte)
// * -> responseWriterState.writeChunk (most of the magic; see comment there)
func (w *http2responseWriter) Write(p []byte) (n int, err error) {
return w.write(len(p), p, "")
}
func (w *http2responseWriter) WriteString(s string) (n int, err error) {
return w.write(len(s), nil, s)
}
// either dataB or dataS is non-zero.
func (w *http2responseWriter) write(lenData int, dataB []byte, dataS string) (n int, err error) {
rws := w.rws
if rws == nil {
panic("Write called after Handler finished")
}
if !rws.wroteHeader {
w.WriteHeader(200)
}
if !http2bodyAllowedForStatus(rws.status) {
return 0, ErrBodyNotAllowed
}
rws.wroteBytes += int64(len(dataB)) + int64(len(dataS)) // only one can be set
if rws.sentContentLen != 0 && rws.wroteBytes > rws.sentContentLen {
// TODO: send a RST_STREAM
return 0, errors.New("http2: handler wrote more than declared Content-Length")
}
if dataB != nil {
return rws.bw.Write(dataB)
} else {
return rws.bw.WriteString(dataS)
}
}
func (w *http2responseWriter) handlerDone() {
rws := w.rws
dirty := rws.dirty
rws.handlerDone = true
w.Flush()
w.rws = nil
if !dirty {
// Only recycle the pool if all prior Write calls to
// the serverConn goroutine completed successfully. If
// they returned earlier due to resets from the peer
// there might still be write goroutines outstanding
// from the serverConn referencing the rws memory. See
// issue 20704.
http2responseWriterStatePool.Put(rws)
}
}
// Push errors.
var (
http2ErrRecursivePush = errors.New("http2: recursive push not allowed")
http2ErrPushLimitReached = errors.New("http2: push would exceed peer's SETTINGS_MAX_CONCURRENT_STREAMS")
)
var _ Pusher = (*http2responseWriter)(nil)
func (w *http2responseWriter) Push(target string, opts *PushOptions) error {
st := w.rws.stream
sc := st.sc
sc.serveG.checkNotOn()
// No recursive pushes: "PUSH_PROMISE frames MUST only be sent on a peer-initiated stream."
// http://tools.ietf.org/html/rfc7540#section-6.6
if st.isPushed() {
return http2ErrRecursivePush
}
if opts == nil {
opts = new(PushOptions)
}
// Default options.
if opts.Method == "" {
opts.Method = "GET"
}
if opts.Header == nil {
opts.Header = Header{}
}
wantScheme := "http"
if w.rws.req.TLS != nil {
wantScheme = "https"
}
// Validate the request.
u, err := url.Parse(target)
if err != nil {
return err
}
if u.Scheme == "" {
if !strings.HasPrefix(target, "/") {
return fmt.Errorf("target must be an absolute URL or an absolute path: %q", target)
}
u.Scheme = wantScheme
u.Host = w.rws.req.Host
} else {
if u.Scheme != wantScheme {
return fmt.Errorf("cannot push URL with scheme %q from request with scheme %q", u.Scheme, wantScheme)
}
if u.Host == "" {
return errors.New("URL must have a host")
}
}
for k := range opts.Header {
if strings.HasPrefix(k, ":") {
return fmt.Errorf("promised request headers cannot include pseudo header %q", k)
}
// These headers are meaningful only if the request has a body,
// but PUSH_PROMISE requests cannot have a body.
// http://tools.ietf.org/html/rfc7540#section-8.2
// Also disallow Host, since the promised URL must be absolute.
switch strings.ToLower(k) {
case "content-length", "content-encoding", "trailer", "te", "expect", "host":
return fmt.Errorf("promised request headers cannot include %q", k)
}
}
if err := http2checkValidHTTP2RequestHeaders(opts.Header); err != nil {
return err
}
// The RFC effectively limits promised requests to GET and HEAD:
// "Promised requests MUST be cacheable [GET, HEAD, or POST], and MUST be safe [GET or HEAD]"
// http://tools.ietf.org/html/rfc7540#section-8.2
if opts.Method != "GET" && opts.Method != "HEAD" {
return fmt.Errorf("method %q must be GET or HEAD", opts.Method)
}
msg := &http2startPushRequest{
parent: st,
method: opts.Method,
url: u,
header: http2cloneHeader(opts.Header),
done: http2errChanPool.Get().(chan error),
}
select {
case <-sc.doneServing:
return http2errClientDisconnected
case <-st.cw:
return http2errStreamClosed
case sc.serveMsgCh <- msg:
}
select {
case <-sc.doneServing:
return http2errClientDisconnected
case <-st.cw:
return http2errStreamClosed
case err := <-msg.done:
http2errChanPool.Put(msg.done)
return err
}
}
type http2startPushRequest struct {
parent *http2stream
method string
url *url.URL
header Header
done chan error
}
func (sc *http2serverConn) startPush(msg *http2startPushRequest) {
sc.serveG.check()
// http://tools.ietf.org/html/rfc7540#section-6.6.
// PUSH_PROMISE frames MUST only be sent on a peer-initiated stream that
// is in either the "open" or "half-closed (remote)" state.
if msg.parent.state != http2stateOpen && msg.parent.state != http2stateHalfClosedRemote {
// responseWriter.Push checks that the stream is peer-initiaed.
msg.done <- http2errStreamClosed
return
}
// http://tools.ietf.org/html/rfc7540#section-6.6.
if !sc.pushEnabled {
msg.done <- ErrNotSupported
return
}
// PUSH_PROMISE frames must be sent in increasing order by stream ID, so
// we allocate an ID for the promised stream lazily, when the PUSH_PROMISE
// is written. Once the ID is allocated, we start the request handler.
allocatePromisedID := func() (uint32, error) {
sc.serveG.check()
// Check this again, just in case. Technically, we might have received
// an updated SETTINGS by the time we got around to writing this frame.
if !sc.pushEnabled {
return 0, ErrNotSupported
}
// http://tools.ietf.org/html/rfc7540#section-6.5.2.
if sc.curPushedStreams+1 > sc.clientMaxStreams {
return 0, http2ErrPushLimitReached
}
// http://tools.ietf.org/html/rfc7540#section-5.1.1.
// Streams initiated by the server MUST use even-numbered identifiers.
// A server that is unable to establish a new stream identifier can send a GOAWAY
// frame so that the client is forced to open a new connection for new streams.
if sc.maxPushPromiseID+2 >= 1<<31 {
sc.startGracefulShutdownInternal()
return 0, http2ErrPushLimitReached
}
sc.maxPushPromiseID += 2
promisedID := sc.maxPushPromiseID
// http://tools.ietf.org/html/rfc7540#section-8.2.
// Strictly speaking, the new stream should start in "reserved (local)", then
// transition to "half closed (remote)" after sending the initial HEADERS, but
// we start in "half closed (remote)" for simplicity.
// See further comments at the definition of stateHalfClosedRemote.
promised := sc.newStream(promisedID, msg.parent.id, http2stateHalfClosedRemote)
rw, req, err := sc.newWriterAndRequestNoBody(promised, http2requestParam{
method: msg.method,
scheme: msg.url.Scheme,
authority: msg.url.Host,
path: msg.url.RequestURI(),
header: http2cloneHeader(msg.header), // clone since handler runs concurrently with writing the PUSH_PROMISE
})
if err != nil {
// Should not happen, since we've already validated msg.url.
panic(fmt.Sprintf("newWriterAndRequestNoBody(%+v): %v", msg.url, err))
}
go sc.runHandler(rw, req, sc.handler.ServeHTTP)
return promisedID, nil
}
sc.writeFrame(http2FrameWriteRequest{
write: &http2writePushPromise{
streamID: msg.parent.id,
method: msg.method,
url: msg.url,
h: msg.header,
allocatePromisedID: allocatePromisedID,
},
stream: msg.parent,
done: msg.done,
})
}
// foreachHeaderElement splits v according to the "#rule" construction
// in RFC 7230 section 7 and calls fn for each non-empty element.
func http2foreachHeaderElement(v string, fn func(string)) {
v = textproto.TrimString(v)
if v == "" {
return
}
if !strings.Contains(v, ",") {
fn(v)
return
}
for _, f := range strings.Split(v, ",") {
if f = textproto.TrimString(f); f != "" {
fn(f)
}
}
}
// From http://httpwg.org/specs/rfc7540.html#rfc.section.8.1.2.2
var http2connHeaders = []string{
"Connection",
"Keep-Alive",
"Proxy-Connection",
"Transfer-Encoding",
"Upgrade",
}
// checkValidHTTP2RequestHeaders checks whether h is a valid HTTP/2 request,
// per RFC 7540 Section 8.1.2.2.
// The returned error is reported to users.
func http2checkValidHTTP2RequestHeaders(h Header) error {
for _, k := range http2connHeaders {
if _, ok := h[k]; ok {
return fmt.Errorf("request header %q is not valid in HTTP/2", k)
}
}
te := h["Te"]
if len(te) > 0 && (len(te) > 1 || (te[0] != "trailers" && te[0] != "")) {
return errors.New(`request header "TE" may only be "trailers" in HTTP/2`)
}
return nil
}
func http2new400Handler(err error) HandlerFunc {
return func(w ResponseWriter, r *Request) {
Error(w, err.Error(), StatusBadRequest)
}
}
// h1ServerKeepAlivesDisabled reports whether hs has its keep-alives
// disabled. See comments on h1ServerShutdownChan above for why
// the code is written this way.
func http2h1ServerKeepAlivesDisabled(hs *Server) bool {
var x interface{} = hs
type I interface {
doKeepAlives() bool
}
if hs, ok := x.(I); ok {
return !hs.doKeepAlives()
}
return false
}
const (
// transportDefaultConnFlow is how many connection-level flow control
// tokens we give the server at start-up, past the default 64k.
http2transportDefaultConnFlow = 1 << 30
// transportDefaultStreamFlow is how many stream-level flow
// control tokens we announce to the peer, and how many bytes
// we buffer per stream.
http2transportDefaultStreamFlow = 4 << 20
// transportDefaultStreamMinRefresh is the minimum number of bytes we'll send
// a stream-level WINDOW_UPDATE for at a time.
http2transportDefaultStreamMinRefresh = 4 << 10
http2defaultUserAgent = "Go-http-client/2.0"
)
// Transport is an HTTP/2 Transport.
//
// A Transport internally caches connections to servers. It is safe
// for concurrent use by multiple goroutines.
type http2Transport struct {
// DialTLS specifies an optional dial function for creating
// TLS connections for requests.
//
// If DialTLS is nil, tls.Dial is used.
//
// If the returned net.Conn has a ConnectionState method like tls.Conn,
// it will be used to set http.Response.TLS.
DialTLS func(network, addr string, cfg *tls.Config) (net.Conn, error)
// TLSClientConfig specifies the TLS configuration to use with
// tls.Client. If nil, the default configuration is used.
TLSClientConfig *tls.Config
// ConnPool optionally specifies an alternate connection pool to use.
// If nil, the default is used.
ConnPool http2ClientConnPool
// DisableCompression, if true, prevents the Transport from
// requesting compression with an "Accept-Encoding: gzip"
// request header when the Request contains no existing
// Accept-Encoding value. If the Transport requests gzip on
// its own and gets a gzipped response, it's transparently
// decoded in the Response.Body. However, if the user
// explicitly requested gzip it is not automatically
// uncompressed.
DisableCompression bool
// AllowHTTP, if true, permits HTTP/2 requests using the insecure,
// plain-text "http" scheme. Note that this does not enable h2c support.
AllowHTTP bool
// MaxHeaderListSize is the http2 SETTINGS_MAX_HEADER_LIST_SIZE to
// send in the initial settings frame. It is how many bytes
// of response headers are allowed. Unlike the http2 spec, zero here
// means to use a default limit (currently 10MB). If you actually
// want to advertise an ulimited value to the peer, Transport
// interprets the highest possible value here (0xffffffff or 1<<32-1)
// to mean no limit.
MaxHeaderListSize uint32
// StrictMaxConcurrentStreams controls whether the server's
// SETTINGS_MAX_CONCURRENT_STREAMS should be respected
// globally. If false, new TCP connections are created to the
// server as needed to keep each under the per-connection
// SETTINGS_MAX_CONCURRENT_STREAMS limit. If true, the
// server's SETTINGS_MAX_CONCURRENT_STREAMS is interpreted as
// a global limit and callers of RoundTrip block when needed,
// waiting for their turn.
StrictMaxConcurrentStreams bool
// t1, if non-nil, is the standard library Transport using
// this transport. Its settings are used (but not its
// RoundTrip method, etc).
t1 *Transport
connPoolOnce sync.Once
connPoolOrDef http2ClientConnPool // non-nil version of ConnPool
}
func (t *http2Transport) maxHeaderListSize() uint32 {
if t.MaxHeaderListSize == 0 {
return 10 << 20
}
if t.MaxHeaderListSize == 0xffffffff {
return 0
}
return t.MaxHeaderListSize
}
func (t *http2Transport) disableCompression() bool {
return t.DisableCompression || (t.t1 != nil && t.t1.DisableCompression)
}
// ConfigureTransport configures a net/http HTTP/1 Transport to use HTTP/2.
// It returns an error if t1 has already been HTTP/2-enabled.
func http2ConfigureTransport(t1 *Transport) error {
_, err := http2configureTransport(t1)
return err
}
func http2configureTransport(t1 *Transport) (*http2Transport, error) {
connPool := new(http2clientConnPool)
t2 := &http2Transport{
ConnPool: http2noDialClientConnPool{connPool},
t1: t1,
}
connPool.t = t2
if err := http2registerHTTPSProtocol(t1, http2noDialH2RoundTripper{t2}); err != nil {
return nil, err
}
if t1.TLSClientConfig == nil {
t1.TLSClientConfig = new(tls.Config)
}
if !http2strSliceContains(t1.TLSClientConfig.NextProtos, "h2") {
t1.TLSClientConfig.NextProtos = append([]string{"h2"}, t1.TLSClientConfig.NextProtos...)
}
if !http2strSliceContains(t1.TLSClientConfig.NextProtos, "http/1.1") {
t1.TLSClientConfig.NextProtos = append(t1.TLSClientConfig.NextProtos, "http/1.1")
}
upgradeFn := func(authority string, c *tls.Conn) RoundTripper {
addr := http2authorityAddr("https", authority)
if used, err := connPool.addConnIfNeeded(addr, t2, c); err != nil {
go c.Close()
return http2erringRoundTripper{err}
} else if !used {
// Turns out we don't need this c.
// For example, two goroutines made requests to the same host
// at the same time, both kicking off TCP dials. (since protocol
// was unknown)
go c.Close()
}
return t2
}
if m := t1.TLSNextProto; len(m) == 0 {
t1.TLSNextProto = map[string]func(string, *tls.Conn) RoundTripper{
"h2": upgradeFn,
}
} else {
m["h2"] = upgradeFn
}
return t2, nil
}
func (t *http2Transport) connPool() http2ClientConnPool {
t.connPoolOnce.Do(t.initConnPool)
return t.connPoolOrDef
}
func (t *http2Transport) initConnPool() {
if t.ConnPool != nil {
t.connPoolOrDef = t.ConnPool
} else {
t.connPoolOrDef = &http2clientConnPool{t: t}
}
}
// ClientConn is the state of a single HTTP/2 client connection to an
// HTTP/2 server.
type http2ClientConn struct {
t *http2Transport
tconn net.Conn // usually *tls.Conn, except specialized impls
tlsState *tls.ConnectionState // nil only for specialized impls
singleUse bool // whether being used for a single http.Request
// readLoop goroutine fields:
readerDone chan struct{} // closed on error
readerErr error // set before readerDone is closed
idleTimeout time.Duration // or 0 for never
idleTimer *time.Timer
mu sync.Mutex // guards following
cond *sync.Cond // hold mu; broadcast on flow/closed changes
flow http2flow // our conn-level flow control quota (cs.flow is per stream)
inflow http2flow // peer's conn-level flow control
closing bool
closed bool
wantSettingsAck bool // we sent a SETTINGS frame and haven't heard back
goAway *http2GoAwayFrame // if non-nil, the GoAwayFrame we received
goAwayDebug string // goAway frame's debug data, retained as a string
streams map[uint32]*http2clientStream // client-initiated
nextStreamID uint32
pendingRequests int // requests blocked and waiting to be sent because len(streams) == maxConcurrentStreams
pings map[[8]byte]chan struct{} // in flight ping data to notification channel
bw *bufio.Writer
br *bufio.Reader
fr *http2Framer
lastActive time.Time
// Settings from peer: (also guarded by mu)
maxFrameSize uint32
maxConcurrentStreams uint32
peerMaxHeaderListSize uint64
initialWindowSize uint32
hbuf bytes.Buffer // HPACK encoder writes into this
henc *hpack.Encoder
freeBuf [][]byte
wmu sync.Mutex // held while writing; acquire AFTER mu if holding both
werr error // first write error that has occurred
}
// clientStream is the state for a single HTTP/2 stream. One of these
// is created for each Transport.RoundTrip call.
type http2clientStream struct {
cc *http2ClientConn
req *Request
trace *httptrace.ClientTrace // or nil
ID uint32
resc chan http2resAndError
bufPipe http2pipe // buffered pipe with the flow-controlled response payload
startedWrite bool // started request body write; guarded by cc.mu
requestedGzip bool
on100 func() // optional code to run if get a 100 continue response
flow http2flow // guarded by cc.mu
inflow http2flow // guarded by cc.mu
bytesRemain int64 // -1 means unknown; owned by transportResponseBody.Read
readErr error // sticky read error; owned by transportResponseBody.Read
stopReqBody error // if non-nil, stop writing req body; guarded by cc.mu
didReset bool // whether we sent a RST_STREAM to the server; guarded by cc.mu
peerReset chan struct{} // closed on peer reset
resetErr error // populated before peerReset is closed
done chan struct{} // closed when stream remove from cc.streams map; close calls guarded by cc.mu
// owned by clientConnReadLoop:
firstByte bool // got the first response byte
pastHeaders bool // got first MetaHeadersFrame (actual headers)
pastTrailers bool // got optional second MetaHeadersFrame (trailers)
num1xx uint8 // number of 1xx responses seen
trailer Header // accumulated trailers
resTrailer *Header // client's Response.Trailer
}
// awaitRequestCancel waits for the user to cancel a request or for the done
// channel to be signaled. A non-nil error is returned only if the request was
// canceled.
func http2awaitRequestCancel(req *Request, done <-chan struct{}) error {
ctx := req.Context()
if req.Cancel == nil && ctx.Done() == nil {
return nil
}
select {
case <-req.Cancel:
return http2errRequestCanceled
case <-ctx.Done():
return ctx.Err()
case <-done:
return nil
}
}
var http2got1xxFuncForTests func(int, textproto.MIMEHeader) error
// get1xxTraceFunc returns the value of request's httptrace.ClientTrace.Got1xxResponse func,
// if any. It returns nil if not set or if the Go version is too old.
func (cs *http2clientStream) get1xxTraceFunc() func(int, textproto.MIMEHeader) error {
if fn := http2got1xxFuncForTests; fn != nil {
return fn
}
return http2traceGot1xxResponseFunc(cs.trace)
}
// awaitRequestCancel waits for the user to cancel a request, its context to
// expire, or for the request to be done (any way it might be removed from the
// cc.streams map: peer reset, successful completion, TCP connection breakage,
// etc). If the request is canceled, then cs will be canceled and closed.
func (cs *http2clientStream) awaitRequestCancel(req *Request) {
if err := http2awaitRequestCancel(req, cs.done); err != nil {
cs.cancelStream()
cs.bufPipe.CloseWithError(err)
}
}
func (cs *http2clientStream) cancelStream() {
cc := cs.cc
cc.mu.Lock()
didReset := cs.didReset
cs.didReset = true
cc.mu.Unlock()
if !didReset {
cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
cc.forgetStreamID(cs.ID)
}
}
// checkResetOrDone reports any error sent in a RST_STREAM frame by the
// server, or errStreamClosed if the stream is complete.
func (cs *http2clientStream) checkResetOrDone() error {
select {
case <-cs.peerReset:
return cs.resetErr
case <-cs.done:
return http2errStreamClosed
default:
return nil
}
}
func (cs *http2clientStream) getStartedWrite() bool {
cc := cs.cc
cc.mu.Lock()
defer cc.mu.Unlock()
return cs.startedWrite
}
func (cs *http2clientStream) abortRequestBodyWrite(err error) {
if err == nil {
panic("nil error")
}
cc := cs.cc
cc.mu.Lock()
cs.stopReqBody = err
cc.cond.Broadcast()
cc.mu.Unlock()
}
type http2stickyErrWriter struct {
w io.Writer
err *error
}
func (sew http2stickyErrWriter) Write(p []byte) (n int, err error) {
if *sew.err != nil {
return 0, *sew.err
}
n, err = sew.w.Write(p)
*sew.err = err
return
}
// noCachedConnError is the concrete type of ErrNoCachedConn, which
// needs to be detected by net/http regardless of whether it's its
// bundled version (in h2_bundle.go with a rewritten type name) or
// from a user's x/net/http2. As such, as it has a unique method name
// (IsHTTP2NoCachedConnError) that net/http sniffs for via func
// isNoCachedConnError.
type http2noCachedConnError struct{}
func (http2noCachedConnError) IsHTTP2NoCachedConnError() {}
func (http2noCachedConnError) Error() string { return "http2: no cached connection was available" }
// isNoCachedConnError reports whether err is of type noCachedConnError
// or its equivalent renamed type in net/http2's h2_bundle.go. Both types
// may coexist in the same running program.
func http2isNoCachedConnError(err error) bool {
_, ok := err.(interface{ IsHTTP2NoCachedConnError() })
return ok
}
var http2ErrNoCachedConn error = http2noCachedConnError{}
// RoundTripOpt are options for the Transport.RoundTripOpt method.
type http2RoundTripOpt struct {
// OnlyCachedConn controls whether RoundTripOpt may
// create a new TCP connection. If set true and
// no cached connection is available, RoundTripOpt
// will return ErrNoCachedConn.
OnlyCachedConn bool
}
func (t *http2Transport) RoundTrip(req *Request) (*Response, error) {
return t.RoundTripOpt(req, http2RoundTripOpt{})
}
// authorityAddr returns a given authority (a host/IP, or host:port / ip:port)
// and returns a host:port. The port 443 is added if needed.
func http2authorityAddr(scheme string, authority string) (addr string) {
host, port, err := net.SplitHostPort(authority)
if err != nil { // authority didn't have a port
port = "443"
if scheme == "http" {
port = "80"
}
host = authority
}
if a, err := idna.ToASCII(host); err == nil {
host = a
}
// IPv6 address literal, without a port:
if strings.HasPrefix(host, "[") && strings.HasSuffix(host, "]") {
return host + ":" + port
}
return net.JoinHostPort(host, port)
}
// RoundTripOpt is like RoundTrip, but takes options.
func (t *http2Transport) RoundTripOpt(req *Request, opt http2RoundTripOpt) (*Response, error) {
if !(req.URL.Scheme == "https" || (req.URL.Scheme == "http" && t.AllowHTTP)) {
return nil, errors.New("http2: unsupported scheme")
}
addr := http2authorityAddr(req.URL.Scheme, req.URL.Host)
for retry := 0; ; retry++ {
cc, err := t.connPool().GetClientConn(req, addr)
if err != nil {
t.vlogf("http2: Transport failed to get client conn for %s: %v", addr, err)
return nil, err
}
http2traceGotConn(req, cc)
res, gotErrAfterReqBodyWrite, err := cc.roundTrip(req)
if err != nil && retry <= 6 {
if req, err = http2shouldRetryRequest(req, err, gotErrAfterReqBodyWrite); err == nil {
// After the first retry, do exponential backoff with 10% jitter.
if retry == 0 {
continue
}
backoff := float64(uint(1) << (uint(retry) - 1))
backoff += backoff * (0.1 * mathrand.Float64())
select {
case <-time.After(time.Second * time.Duration(backoff)):
continue
case <-req.Context().Done():
return nil, req.Context().Err()
}
}
}
if err != nil {
t.vlogf("RoundTrip failure: %v", err)
return nil, err
}
return res, nil
}
}
// CloseIdleConnections closes any connections which were previously
// connected from previous requests but are now sitting idle.
// It does not interrupt any connections currently in use.
func (t *http2Transport) CloseIdleConnections() {
if cp, ok := t.connPool().(http2clientConnPoolIdleCloser); ok {
cp.closeIdleConnections()
}
}
var (
http2errClientConnClosed = errors.New("http2: client conn is closed")
http2errClientConnUnusable = errors.New("http2: client conn not usable")
http2errClientConnGotGoAway = errors.New("http2: Transport received Server's graceful shutdown GOAWAY")
)
// shouldRetryRequest is called by RoundTrip when a request fails to get
// response headers. It is always called with a non-nil error.
// It returns either a request to retry (either the same request, or a
// modified clone), or an error if the request can't be replayed.
func http2shouldRetryRequest(req *Request, err error, afterBodyWrite bool) (*Request, error) {
if !http2canRetryError(err) {
return nil, err
}
// If the Body is nil (or http.NoBody), it's safe to reuse
// this request and its Body.
if req.Body == nil || req.Body == NoBody {
return req, nil
}
// If the request body can be reset back to its original
// state via the optional req.GetBody, do that.
if req.GetBody != nil {
// TODO: consider a req.Body.Close here? or audit that all caller paths do?
body, err := req.GetBody()
if err != nil {
return nil, err
}
newReq := *req
newReq.Body = body
return &newReq, nil
}
// The Request.Body can't reset back to the beginning, but we
// don't seem to have started to read from it yet, so reuse
// the request directly. The "afterBodyWrite" means the
// bodyWrite process has started, which becomes true before
// the first Read.
if !afterBodyWrite {
return req, nil
}
return nil, fmt.Errorf("http2: Transport: cannot retry err [%v] after Request.Body was written; define Request.GetBody to avoid this error", err)
}
func http2canRetryError(err error) bool {
if err == http2errClientConnUnusable || err == http2errClientConnGotGoAway {
return true
}
if se, ok := err.(http2StreamError); ok {
return se.Code == http2ErrCodeRefusedStream
}
return false
}
func (t *http2Transport) dialClientConn(addr string, singleUse bool) (*http2ClientConn, error) {
host, _, err := net.SplitHostPort(addr)
if err != nil {
return nil, err
}
tconn, err := t.dialTLS()("tcp", addr, t.newTLSConfig(host))
if err != nil {
return nil, err
}
return t.newClientConn(tconn, singleUse)
}
func (t *http2Transport) newTLSConfig(host string) *tls.Config {
cfg := new(tls.Config)
if t.TLSClientConfig != nil {
*cfg = *t.TLSClientConfig.Clone()
}
if !http2strSliceContains(cfg.NextProtos, http2NextProtoTLS) {
cfg.NextProtos = append([]string{http2NextProtoTLS}, cfg.NextProtos...)
}
if cfg.ServerName == "" {
cfg.ServerName = host
}
return cfg
}
func (t *http2Transport) dialTLS() func(string, string, *tls.Config) (net.Conn, error) {
if t.DialTLS != nil {
return t.DialTLS
}
return t.dialTLSDefault
}
func (t *http2Transport) dialTLSDefault(network, addr string, cfg *tls.Config) (net.Conn, error) {
cn, err := tls.Dial(network, addr, cfg)
if err != nil {
return nil, err
}
if err := cn.Handshake(); err != nil {
return nil, err
}
if !cfg.InsecureSkipVerify {
if err := cn.VerifyHostname(cfg.ServerName); err != nil {
return nil, err
}
}
state := cn.ConnectionState()
if p := state.NegotiatedProtocol; p != http2NextProtoTLS {
return nil, fmt.Errorf("http2: unexpected ALPN protocol %q; want %q", p, http2NextProtoTLS)
}
if !state.NegotiatedProtocolIsMutual {
return nil, errors.New("http2: could not negotiate protocol mutually")
}
return cn, nil
}
// disableKeepAlives reports whether connections should be closed as
// soon as possible after handling the first request.
func (t *http2Transport) disableKeepAlives() bool {
return t.t1 != nil && t.t1.DisableKeepAlives
}
func (t *http2Transport) expectContinueTimeout() time.Duration {
if t.t1 == nil {
return 0
}
return t.t1.ExpectContinueTimeout
}
func (t *http2Transport) NewClientConn(c net.Conn) (*http2ClientConn, error) {
return t.newClientConn(c, false)
}
func (t *http2Transport) newClientConn(c net.Conn, singleUse bool) (*http2ClientConn, error) {
cc := &http2ClientConn{
t: t,
tconn: c,
readerDone: make(chan struct{}),
nextStreamID: 1,
maxFrameSize: 16 << 10, // spec default
initialWindowSize: 65535, // spec default
maxConcurrentStreams: 1000, // "infinite", per spec. 1000 seems good enough.
peerMaxHeaderListSize: 0xffffffffffffffff, // "infinite", per spec. Use 2^64-1 instead.
streams: make(map[uint32]*http2clientStream),
singleUse: singleUse,
wantSettingsAck: true,
pings: make(map[[8]byte]chan struct{}),
}
if d := t.idleConnTimeout(); d != 0 {
cc.idleTimeout = d
cc.idleTimer = time.AfterFunc(d, cc.onIdleTimeout)
}
if http2VerboseLogs {
t.vlogf("http2: Transport creating client conn %p to %v", cc, c.RemoteAddr())
}
cc.cond = sync.NewCond(&cc.mu)
cc.flow.add(int32(http2initialWindowSize))
// TODO: adjust this writer size to account for frame size +
// MTU + crypto/tls record padding.
cc.bw = bufio.NewWriter(http2stickyErrWriter{c, &cc.werr})
cc.br = bufio.NewReader(c)
cc.fr = http2NewFramer(cc.bw, cc.br)
cc.fr.ReadMetaHeaders = hpack.NewDecoder(http2initialHeaderTableSize, nil)
cc.fr.MaxHeaderListSize = t.maxHeaderListSize()
// TODO: SetMaxDynamicTableSize, SetMaxDynamicTableSizeLimit on
// henc in response to SETTINGS frames?
cc.henc = hpack.NewEncoder(&cc.hbuf)
if t.AllowHTTP {
cc.nextStreamID = 3
}
if cs, ok := c.(http2connectionStater); ok {
state := cs.ConnectionState()
cc.tlsState = &state
}
initialSettings := []http2Setting{
{ID: http2SettingEnablePush, Val: 0},
{ID: http2SettingInitialWindowSize, Val: http2transportDefaultStreamFlow},
}
if max := t.maxHeaderListSize(); max != 0 {
initialSettings = append(initialSettings, http2Setting{ID: http2SettingMaxHeaderListSize, Val: max})
}
cc.bw.Write(http2clientPreface)
cc.fr.WriteSettings(initialSettings...)
cc.fr.WriteWindowUpdate(0, http2transportDefaultConnFlow)
cc.inflow.add(http2transportDefaultConnFlow + http2initialWindowSize)
cc.bw.Flush()
if cc.werr != nil {
return nil, cc.werr
}
go cc.readLoop()
return cc, nil
}
func (cc *http2ClientConn) setGoAway(f *http2GoAwayFrame) {
cc.mu.Lock()
defer cc.mu.Unlock()
old := cc.goAway
cc.goAway = f
// Merge the previous and current GoAway error frames.
if cc.goAwayDebug == "" {
cc.goAwayDebug = string(f.DebugData())
}
if old != nil && old.ErrCode != http2ErrCodeNo {
cc.goAway.ErrCode = old.ErrCode
}
last := f.LastStreamID
for streamID, cs := range cc.streams {
if streamID > last {
select {
case cs.resc <- http2resAndError{err: http2errClientConnGotGoAway}:
default:
}
}
}
}
// CanTakeNewRequest reports whether the connection can take a new request,
// meaning it has not been closed or received or sent a GOAWAY.
func (cc *http2ClientConn) CanTakeNewRequest() bool {
cc.mu.Lock()
defer cc.mu.Unlock()
return cc.canTakeNewRequestLocked()
}
// clientConnIdleState describes the suitability of a client
// connection to initiate a new RoundTrip request.
type http2clientConnIdleState struct {
canTakeNewRequest bool
freshConn bool // whether it's unused by any previous request
}
func (cc *http2ClientConn) idleState() http2clientConnIdleState {
cc.mu.Lock()
defer cc.mu.Unlock()
return cc.idleStateLocked()
}
func (cc *http2ClientConn) idleStateLocked() (st http2clientConnIdleState) {
if cc.singleUse && cc.nextStreamID > 1 {
return
}
var maxConcurrentOkay bool
if cc.t.StrictMaxConcurrentStreams {
// We'll tell the caller we can take a new request to
// prevent the caller from dialing a new TCP
// connection, but then we'll block later before
// writing it.
maxConcurrentOkay = true
} else {
maxConcurrentOkay = int64(len(cc.streams)+1) < int64(cc.maxConcurrentStreams)
}
st.canTakeNewRequest = cc.goAway == nil && !cc.closed && !cc.closing && maxConcurrentOkay &&
int64(cc.nextStreamID)+2*int64(cc.pendingRequests) < math.MaxInt32
st.freshConn = cc.nextStreamID == 1 && st.canTakeNewRequest
return
}
func (cc *http2ClientConn) canTakeNewRequestLocked() bool {
st := cc.idleStateLocked()
return st.canTakeNewRequest
}
// onIdleTimeout is called from a time.AfterFunc goroutine. It will
// only be called when we're idle, but because we're coming from a new
// goroutine, there could be a new request coming in at the same time,
// so this simply calls the synchronized closeIfIdle to shut down this
// connection. The timer could just call closeIfIdle, but this is more
// clear.
func (cc *http2ClientConn) onIdleTimeout() {
cc.closeIfIdle()
}
func (cc *http2ClientConn) closeIfIdle() {
cc.mu.Lock()
if len(cc.streams) > 0 {
cc.mu.Unlock()
return
}
cc.closed = true
nextID := cc.nextStreamID
// TODO: do clients send GOAWAY too? maybe? Just Close:
cc.mu.Unlock()
if http2VerboseLogs {
cc.vlogf("http2: Transport closing idle conn %p (forSingleUse=%v, maxStream=%v)", cc, cc.singleUse, nextID-2)
}
cc.tconn.Close()
}
var http2shutdownEnterWaitStateHook = func() {}
// Shutdown gracefully close the client connection, waiting for running streams to complete.
func (cc *http2ClientConn) Shutdown(ctx context.Context) error {
if err := cc.sendGoAway(); err != nil {
return err
}
// Wait for all in-flight streams to complete or connection to close
done := make(chan error, 1)
cancelled := false // guarded by cc.mu
go func() {
cc.mu.Lock()
defer cc.mu.Unlock()
for {
if len(cc.streams) == 0 || cc.closed {
cc.closed = true
done <- cc.tconn.Close()
break
}
if cancelled {
break
}
cc.cond.Wait()
}
}()
http2shutdownEnterWaitStateHook()
select {
case err := <-done:
return err
case <-ctx.Done():
cc.mu.Lock()
// Free the goroutine above
cancelled = true
cc.cond.Broadcast()
cc.mu.Unlock()
return ctx.Err()
}
}
func (cc *http2ClientConn) sendGoAway() error {
cc.mu.Lock()
defer cc.mu.Unlock()
cc.wmu.Lock()
defer cc.wmu.Unlock()
if cc.closing {
// GOAWAY sent already
return nil
}
// Send a graceful shutdown frame to server
maxStreamID := cc.nextStreamID
if err := cc.fr.WriteGoAway(maxStreamID, http2ErrCodeNo, nil); err != nil {
return err
}
if err := cc.bw.Flush(); err != nil {
return err
}
// Prevent new requests
cc.closing = true
return nil
}
// Close closes the client connection immediately.
//
// In-flight requests are interrupted. For a graceful shutdown, use Shutdown instead.
func (cc *http2ClientConn) Close() error {
cc.mu.Lock()
defer cc.cond.Broadcast()
defer cc.mu.Unlock()
err := errors.New("http2: client connection force closed via ClientConn.Close")
for id, cs := range cc.streams {
select {
case cs.resc <- http2resAndError{err: err}:
default:
}
cs.bufPipe.CloseWithError(err)
delete(cc.streams, id)
}
cc.closed = true
return cc.tconn.Close()
}
const http2maxAllocFrameSize = 512 << 10
// frameBuffer returns a scratch buffer suitable for writing DATA frames.
// They're capped at the min of the peer's max frame size or 512KB
// (kinda arbitrarily), but definitely capped so we don't allocate 4GB
// bufers.
func (cc *http2ClientConn) frameScratchBuffer() []byte {
cc.mu.Lock()
size := cc.maxFrameSize
if size > http2maxAllocFrameSize {
size = http2maxAllocFrameSize
}
for i, buf := range cc.freeBuf {
if len(buf) >= int(size) {
cc.freeBuf[i] = nil
cc.mu.Unlock()
return buf[:size]
}
}
cc.mu.Unlock()
return make([]byte, size)
}
func (cc *http2ClientConn) putFrameScratchBuffer(buf []byte) {
cc.mu.Lock()
defer cc.mu.Unlock()
const maxBufs = 4 // arbitrary; 4 concurrent requests per conn? investigate.
if len(cc.freeBuf) < maxBufs {
cc.freeBuf = append(cc.freeBuf, buf)
return
}
for i, old := range cc.freeBuf {
if old == nil {
cc.freeBuf[i] = buf
return
}
}
// forget about it.
}
// errRequestCanceled is a copy of net/http's errRequestCanceled because it's not
// exported. At least they'll be DeepEqual for h1-vs-h2 comparisons tests.
var http2errRequestCanceled = errors.New("net/http: request canceled")
func http2commaSeparatedTrailers(req *Request) (string, error) {
keys := make([]string, 0, len(req.Trailer))
for k := range req.Trailer {
k = CanonicalHeaderKey(k)
switch k {
case "Transfer-Encoding", "Trailer", "Content-Length":
return "", &http2badStringError{"invalid Trailer key", k}
}
keys = append(keys, k)
}
if len(keys) > 0 {
sort.Strings(keys)
return strings.Join(keys, ","), nil
}
return "", nil
}
func (cc *http2ClientConn) responseHeaderTimeout() time.Duration {
if cc.t.t1 != nil {
return cc.t.t1.ResponseHeaderTimeout
}
// No way to do this (yet?) with just an http2.Transport. Probably
// no need. Request.Cancel this is the new way. We only need to support
// this for compatibility with the old http.Transport fields when
// we're doing transparent http2.
return 0
}
// checkConnHeaders checks whether req has any invalid connection-level headers.
// per RFC 7540 section 8.1.2.2: Connection-Specific Header Fields.
// Certain headers are special-cased as okay but not transmitted later.
func http2checkConnHeaders(req *Request) error {
if v := req.Header.Get("Upgrade"); v != "" {
return fmt.Errorf("http2: invalid Upgrade request header: %q", req.Header["Upgrade"])
}
if vv := req.Header["Transfer-Encoding"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && vv[0] != "chunked") {
return fmt.Errorf("http2: invalid Transfer-Encoding request header: %q", vv)
}
if vv := req.Header["Connection"]; len(vv) > 0 && (len(vv) > 1 || vv[0] != "" && !strings.EqualFold(vv[0], "close") && !strings.EqualFold(vv[0], "keep-alive")) {
return fmt.Errorf("http2: invalid Connection request header: %q", vv)
}
return nil
}
// actualContentLength returns a sanitized version of
// req.ContentLength, where 0 actually means zero (not unknown) and -1
// means unknown.
func http2actualContentLength(req *Request) int64 {
if req.Body == nil || req.Body == NoBody {
return 0
}
if req.ContentLength != 0 {
return req.ContentLength
}
return -1
}
func (cc *http2ClientConn) RoundTrip(req *Request) (*Response, error) {
resp, _, err := cc.roundTrip(req)
return resp, err
}
func (cc *http2ClientConn) roundTrip(req *Request) (res *Response, gotErrAfterReqBodyWrite bool, err error) {
if err := http2checkConnHeaders(req); err != nil {
return nil, false, err
}
if cc.idleTimer != nil {
cc.idleTimer.Stop()
}
trailers, err := http2commaSeparatedTrailers(req)
if err != nil {
return nil, false, err
}
hasTrailers := trailers != ""
cc.mu.Lock()
if err := cc.awaitOpenSlotForRequest(req); err != nil {
cc.mu.Unlock()
return nil, false, err
}
body := req.Body
contentLen := http2actualContentLength(req)
hasBody := contentLen != 0
// TODO(bradfitz): this is a copy of the logic in net/http. Unify somewhere?
var requestedGzip bool
if !cc.t.disableCompression() &&
req.Header.Get("Accept-Encoding") == "" &&
req.Header.Get("Range") == "" &&
req.Method != "HEAD" {
// Request gzip only, not deflate. Deflate is ambiguous and
// not as universally supported anyway.
// See: http://www.gzip.org/zlib/zlib_faq.html#faq38
//
// Note that we don't request this for HEAD requests,
// due to a bug in nginx:
// http://trac.nginx.org/nginx/ticket/358
// https://golang.org/issue/5522
//
// We don't request gzip if the request is for a range, since
// auto-decoding a portion of a gzipped document will just fail
// anyway. See https://golang.org/issue/8923
requestedGzip = true
}
// we send: HEADERS{1}, CONTINUATION{0,} + DATA{0,} (DATA is
// sent by writeRequestBody below, along with any Trailers,
// again in form HEADERS{1}, CONTINUATION{0,})
hdrs, err := cc.encodeHeaders(req, requestedGzip, trailers, contentLen)
if err != nil {
cc.mu.Unlock()
return nil, false, err
}
cs := cc.newStream()
cs.req = req
cs.trace = httptrace.ContextClientTrace(req.Context())
cs.requestedGzip = requestedGzip
bodyWriter := cc.t.getBodyWriterState(cs, body)
cs.on100 = bodyWriter.on100
cc.wmu.Lock()
endStream := !hasBody && !hasTrailers
werr := cc.writeHeaders(cs.ID, endStream, int(cc.maxFrameSize), hdrs)
cc.wmu.Unlock()
http2traceWroteHeaders(cs.trace)
cc.mu.Unlock()
if werr != nil {
if hasBody {
req.Body.Close() // per RoundTripper contract
bodyWriter.cancel()
}
cc.forgetStreamID(cs.ID)
// Don't bother sending a RST_STREAM (our write already failed;
// no need to keep writing)
http2traceWroteRequest(cs.trace, werr)
return nil, false, werr
}
var respHeaderTimer <-chan time.Time
if hasBody {
bodyWriter.scheduleBodyWrite()
} else {
http2traceWroteRequest(cs.trace, nil)
if d := cc.responseHeaderTimeout(); d != 0 {
timer := time.NewTimer(d)
defer timer.Stop()
respHeaderTimer = timer.C
}
}
readLoopResCh := cs.resc
bodyWritten := false
ctx := req.Context()
handleReadLoopResponse := func(re http2resAndError) (*Response, bool, error) {
res := re.res
if re.err != nil || res.StatusCode > 299 {
// On error or status code 3xx, 4xx, 5xx, etc abort any
// ongoing write, assuming that the server doesn't care
// about our request body. If the server replied with 1xx or
// 2xx, however, then assume the server DOES potentially
// want our body (e.g. full-duplex streaming:
// golang.org/issue/13444). If it turns out the server
// doesn't, they'll RST_STREAM us soon enough. This is a
// heuristic to avoid adding knobs to Transport. Hopefully
// we can keep it.
bodyWriter.cancel()
cs.abortRequestBodyWrite(http2errStopReqBodyWrite)
}
if re.err != nil {
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), re.err
}
res.Request = req
res.TLS = cc.tlsState
return res, false, nil
}
for {
select {
case re := <-readLoopResCh:
return handleReadLoopResponse(re)
case <-respHeaderTimer:
if !hasBody || bodyWritten {
cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
} else {
bodyWriter.cancel()
cs.abortRequestBodyWrite(http2errStopReqBodyWriteAndCancel)
}
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), http2errTimeout
case <-ctx.Done():
if !hasBody || bodyWritten {
cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
} else {
bodyWriter.cancel()
cs.abortRequestBodyWrite(http2errStopReqBodyWriteAndCancel)
}
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), ctx.Err()
case <-req.Cancel:
if !hasBody || bodyWritten {
cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
} else {
bodyWriter.cancel()
cs.abortRequestBodyWrite(http2errStopReqBodyWriteAndCancel)
}
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), http2errRequestCanceled
case <-cs.peerReset:
// processResetStream already removed the
// stream from the streams map; no need for
// forgetStreamID.
return nil, cs.getStartedWrite(), cs.resetErr
case err := <-bodyWriter.resc:
// Prefer the read loop's response, if available. Issue 16102.
select {
case re := <-readLoopResCh:
return handleReadLoopResponse(re)
default:
}
if err != nil {
cc.forgetStreamID(cs.ID)
return nil, cs.getStartedWrite(), err
}
bodyWritten = true
if d := cc.responseHeaderTimeout(); d != 0 {
timer := time.NewTimer(d)
defer timer.Stop()
respHeaderTimer = timer.C
}
}
}
}
// awaitOpenSlotForRequest waits until len(streams) < maxConcurrentStreams.
// Must hold cc.mu.
func (cc *http2ClientConn) awaitOpenSlotForRequest(req *Request) error {
var waitingForConn chan struct{}
var waitingForConnErr error // guarded by cc.mu
for {
cc.lastActive = time.Now()
if cc.closed || !cc.canTakeNewRequestLocked() {
if waitingForConn != nil {
close(waitingForConn)
}
return http2errClientConnUnusable
}
if int64(len(cc.streams))+1 <= int64(cc.maxConcurrentStreams) {
if waitingForConn != nil {
close(waitingForConn)
}
return nil
}
// Unfortunately, we cannot wait on a condition variable and channel at
// the same time, so instead, we spin up a goroutine to check if the
// request is canceled while we wait for a slot to open in the connection.
if waitingForConn == nil {
waitingForConn = make(chan struct{})
go func() {
if err := http2awaitRequestCancel(req, waitingForConn); err != nil {
cc.mu.Lock()
waitingForConnErr = err
cc.cond.Broadcast()
cc.mu.Unlock()
}
}()
}
cc.pendingRequests++
cc.cond.Wait()
cc.pendingRequests--
if waitingForConnErr != nil {
return waitingForConnErr
}
}
}
// requires cc.wmu be held
func (cc *http2ClientConn) writeHeaders(streamID uint32, endStream bool, maxFrameSize int, hdrs []byte) error {
first := true // first frame written (HEADERS is first, then CONTINUATION)
for len(hdrs) > 0 && cc.werr == nil {
chunk := hdrs
if len(chunk) > maxFrameSize {
chunk = chunk[:maxFrameSize]
}
hdrs = hdrs[len(chunk):]
endHeaders := len(hdrs) == 0
if first {
cc.fr.WriteHeaders(http2HeadersFrameParam{
StreamID: streamID,
BlockFragment: chunk,
EndStream: endStream,
EndHeaders: endHeaders,
})
first = false
} else {
cc.fr.WriteContinuation(streamID, endHeaders, chunk)
}
}
// TODO(bradfitz): this Flush could potentially block (as
// could the WriteHeaders call(s) above), which means they
// wouldn't respond to Request.Cancel being readable. That's
// rare, but this should probably be in a goroutine.
cc.bw.Flush()
return cc.werr
}
// internal error values; they don't escape to callers
var (
// abort request body write; don't send cancel
http2errStopReqBodyWrite = errors.New("http2: aborting request body write")
// abort request body write, but send stream reset of cancel.
http2errStopReqBodyWriteAndCancel = errors.New("http2: canceling request")
)
func (cs *http2clientStream) writeRequestBody(body io.Reader, bodyCloser io.Closer) (err error) {
cc := cs.cc
sentEnd := false // whether we sent the final DATA frame w/ END_STREAM
buf := cc.frameScratchBuffer()
defer cc.putFrameScratchBuffer(buf)
defer func() {
http2traceWroteRequest(cs.trace, err)
// TODO: write h12Compare test showing whether
// Request.Body is closed by the Transport,
// and in multiple cases: server replies <=299 and >299
// while still writing request body
cerr := bodyCloser.Close()
if err == nil {
err = cerr
}
}()
req := cs.req
hasTrailers := req.Trailer != nil
var sawEOF bool
for !sawEOF {
n, err := body.Read(buf)
if err == io.EOF {
sawEOF = true
err = nil
} else if err != nil {
cc.writeStreamReset(cs.ID, http2ErrCodeCancel, err)
return err
}
remain := buf[:n]
for len(remain) > 0 && err == nil {
var allowed int32
allowed, err = cs.awaitFlowControl(len(remain))
switch {
case err == http2errStopReqBodyWrite:
return err
case err == http2errStopReqBodyWriteAndCancel:
cc.writeStreamReset(cs.ID, http2ErrCodeCancel, nil)
return err
case err != nil:
return err
}
cc.wmu.Lock()
data := remain[:allowed]
remain = remain[allowed:]
sentEnd = sawEOF && len(remain) == 0 && !hasTrailers
err = cc.fr.WriteData(cs.ID, sentEnd, data)
if err == nil {
// TODO(bradfitz): this flush is for latency, not bandwidth.
// Most requests won't need this. Make this opt-in or
// opt-out? Use some heuristic on the body type? Nagel-like
// timers? Based on 'n'? Only last chunk of this for loop,
// unless flow control tokens are low? For now, always.
// If we change this, see comment below.
err = cc.bw.Flush()
}
cc.wmu.Unlock()
}
if err != nil {
return err
}
}
if sentEnd {
// Already sent END_STREAM (which implies we have no
// trailers) and flushed, because currently all
// WriteData frames above get a flush. So we're done.
return nil
}
var trls []byte
if hasTrailers {
cc.mu.Lock()
trls, err = cc.encodeTrailers(req)
cc.mu.Unlock()
if err != nil {
cc.writeStreamReset(cs.ID, http2ErrCodeInternal, err)
cc.forgetStreamID(cs.ID)
return err
}
}
cc.mu.Lock()
maxFrameSize := int(cc.maxFrameSize)
cc.mu.Unlock()
cc.wmu.Lock()
defer cc.wmu.Unlock()
// Two ways to send END_STREAM: either with trailers, or
// with an empty DATA frame.
if len(trls) > 0 {
err = cc.writeHeaders(cs.ID, true, maxFrameSize, trls)
} else {
err = cc.fr.WriteData(cs.ID, true, nil)
}
if ferr := cc.bw.Flush(); ferr != nil && err == nil {
err = ferr
}
return err
}
// awaitFlowControl waits for [1, min(maxBytes, cc.cs.maxFrameSize)] flow
// control tokens from the server.
// It returns either the non-zero number of tokens taken or an error
// if the stream is dead.
func (cs *http2clientStream) awaitFlowControl(maxBytes int) (taken int32, err error) {
cc := cs.cc
cc.mu.Lock()
defer cc.mu.Unlock()
for {
if cc.closed {
return 0, http2errClientConnClosed
}
if cs.stopReqBody != nil {
return 0, cs.stopReqBody
}
if err := cs.checkResetOrDone(); err != nil {
return 0, err
}
if a := cs.flow.available(); a > 0 {
take := a
if int(take) > maxBytes {
take = int32(maxBytes) // can't truncate int; take is int32
}
if take > int32(cc.maxFrameSize) {
take = int32(cc.maxFrameSize)
}
cs.flow.take(take)
return take, nil
}
cc.cond.Wait()
}
}
type http2badStringError struct {
what string
str string
}
func (e *http2badStringError) Error() string { return fmt.Sprintf("%s %q", e.what, e.str) }
// requires cc.mu be held.
func (cc *http2ClientConn) encodeHeaders(req *Request, addGzipHeader bool, trailers string, contentLength int64) ([]byte, error) {
cc.hbuf.Reset()
host := req.Host
if host == "" {
host = req.URL.Host
}
host, err := httpguts.PunycodeHostPort(host)
if err != nil {
return nil, err
}
var path string
if req.Method != "CONNECT" {
path = req.URL.RequestURI()
if !http2validPseudoPath(path) {
orig := path
path = strings.TrimPrefix(path, req.URL.Scheme+"://"+host)
if !http2validPseudoPath(path) {
if req.URL.Opaque != "" {
return nil, fmt.Errorf("invalid request :path %q from URL.Opaque = %q", orig, req.URL.Opaque)
} else {
return nil, fmt.Errorf("invalid request :path %q", orig)
}
}
}
}
// Check for any invalid headers and return an error before we
// potentially pollute our hpack state. (We want to be able to
// continue to reuse the hpack encoder for future requests)
for k, vv := range req.Header {
if !httpguts.ValidHeaderFieldName(k) {
return nil, fmt.Errorf("invalid HTTP header name %q", k)
}
for _, v := range vv {
if !httpguts.ValidHeaderFieldValue(v) {
return nil, fmt.Errorf("invalid HTTP header value %q for header %q", v, k)
}
}
}
enumerateHeaders := func(f func(name, value string)) {
// 8.1.2.3 Request Pseudo-Header Fields
// The :path pseudo-header field includes the path and query parts of the
// target URI (the path-absolute production and optionally a '?' character
// followed by the query production (see Sections 3.3 and 3.4 of
// [RFC3986]).
f(":authority", host)
f(":method", req.Method)
if req.Method != "CONNECT" {
f(":path", path)
f(":scheme", req.URL.Scheme)
}
if trailers != "" {
f("trailer", trailers)
}
var didUA bool
for k, vv := range req.Header {
if strings.EqualFold(k, "host") || strings.EqualFold(k, "content-length") {
// Host is :authority, already sent.
// Content-Length is automatic, set below.
continue
} else if strings.EqualFold(k, "connection") || strings.EqualFold(k, "proxy-connection") ||
strings.EqualFold(k, "transfer-encoding") || strings.EqualFold(k, "upgrade") ||
strings.EqualFold(k, "keep-alive") {
// Per 8.1.2.2 Connection-Specific Header
// Fields, don't send connection-specific
// fields. We have already checked if any
// are error-worthy so just ignore the rest.
continue
} else if strings.EqualFold(k, "user-agent") {
// Match Go's http1 behavior: at most one
// User-Agent. If set to nil or empty string,
// then omit it. Otherwise if not mentioned,
// include the default (below).
didUA = true
if len(vv) < 1 {
continue
}
vv = vv[:1]
if vv[0] == "" {
continue
}
}
for _, v := range vv {
f(k, v)
}
}
if http2shouldSendReqContentLength(req.Method, contentLength) {
f("content-length", strconv.FormatInt(contentLength, 10))
}
if addGzipHeader {
f("accept-encoding", "gzip")
}
if !didUA {
f("user-agent", http2defaultUserAgent)
}
}
// Do a first pass over the headers counting bytes to ensure
// we don't exceed cc.peerMaxHeaderListSize. This is done as a
// separate pass before encoding the headers to prevent
// modifying the hpack state.
hlSize := uint64(0)
enumerateHeaders(func(name, value string) {
hf := hpack.HeaderField{Name: name, Value: value}
hlSize += uint64(hf.Size())
})
if hlSize > cc.peerMaxHeaderListSize {
return nil, http2errRequestHeaderListSize
}
trace := httptrace.ContextClientTrace(req.Context())
traceHeaders := http2traceHasWroteHeaderField(trace)
// Header list size is ok. Write the headers.
enumerateHeaders(func(name, value string) {
name = strings.ToLower(name)
cc.writeHeader(name, value)
if traceHeaders {
http2traceWroteHeaderField(trace, name, value)
}
})
return cc.hbuf.Bytes(), nil
}
// shouldSendReqContentLength reports whether the http2.Transport should send
// a "content-length" request header. This logic is basically a copy of the net/http
// transferWriter.shouldSendContentLength.
// The contentLength is the corrected contentLength (so 0 means actually 0, not unknown).
// -1 means unknown.
func http2shouldSendReqContentLength(method string, contentLength int64) bool {
if contentLength > 0 {
return true
}
if contentLength < 0 {
return false
}
// For zero bodies, whether we send a content-length depends on the method.
// It also kinda doesn't matter for http2 either way, with END_STREAM.
switch method {
case "POST", "PUT", "PATCH":
return true
default:
return false
}
}
// requires cc.mu be held.
func (cc *http2ClientConn) encodeTrailers(req *Request) ([]byte, error) {
cc.hbuf.Reset()
hlSize := uint64(0)
for k, vv := range req.Trailer {
for _, v := range vv {
hf := hpack.HeaderField{Name: k, Value: v}
hlSize += uint64(hf.Size())
}
}
if hlSize > cc.peerMaxHeaderListSize {
return nil, http2errRequestHeaderListSize
}
for k, vv := range req.Trailer {
// Transfer-Encoding, etc.. have already been filtered at the
// start of RoundTrip
lowKey := strings.ToLower(k)
for _, v := range vv {
cc.writeHeader(lowKey, v)
}
}
return cc.hbuf.Bytes(), nil
}
func (cc *http2ClientConn) writeHeader(name, value string) {
if http2VerboseLogs {
log.Printf("http2: Transport encoding header %q = %q", name, value)
}
cc.henc.WriteField(hpack.HeaderField{Name: name, Value: value})
}
type http2resAndError struct {
res *Response
err error
}
// requires cc.mu be held.
func (cc *http2ClientConn) newStream() *http2clientStream {
cs := &http2clientStream{
cc: cc,
ID: cc.nextStreamID,
resc: make(chan http2resAndError, 1),
peerReset: make(chan struct{}),
done: make(chan struct{}),
}
cs.flow.add(int32(cc.initialWindowSize))
cs.flow.setConnFlow(&cc.flow)
cs.inflow.add(http2transportDefaultStreamFlow)
cs.inflow.setConnFlow(&cc.inflow)
cc.nextStreamID += 2
cc.streams[cs.ID] = cs
return cs
}
func (cc *http2ClientConn) forgetStreamID(id uint32) {
cc.streamByID(id, true)
}
func (cc *http2ClientConn) streamByID(id uint32, andRemove bool) *http2clientStream {
cc.mu.Lock()
defer cc.mu.Unlock()
cs := cc.streams[id]
if andRemove && cs != nil && !cc.closed {
cc.lastActive = time.Now()
delete(cc.streams, id)
if len(cc.streams) == 0 && cc.idleTimer != nil {
cc.idleTimer.Reset(cc.idleTimeout)
}
close(cs.done)
// Wake up checkResetOrDone via clientStream.awaitFlowControl and
// wake up RoundTrip if there is a pending request.
cc.cond.Broadcast()
}
return cs
}
// clientConnReadLoop is the state owned by the clientConn's frame-reading readLoop.
type http2clientConnReadLoop struct {
cc *http2ClientConn
closeWhenIdle bool
}
// readLoop runs in its own goroutine and reads and dispatches frames.
func (cc *http2ClientConn) readLoop() {
rl := &http2clientConnReadLoop{cc: cc}
defer rl.cleanup()
cc.readerErr = rl.run()
if ce, ok := cc.readerErr.(http2ConnectionError); ok {
cc.wmu.Lock()
cc.fr.WriteGoAway(0, http2ErrCode(ce), nil)
cc.wmu.Unlock()
}
}
// GoAwayError is returned by the Transport when the server closes the
// TCP connection after sending a GOAWAY frame.
type http2GoAwayError struct {
LastStreamID uint32
ErrCode http2ErrCode
DebugData string
}
func (e http2GoAwayError) Error() string {
return fmt.Sprintf("http2: server sent GOAWAY and closed the connection; LastStreamID=%v, ErrCode=%v, debug=%q",
e.LastStreamID, e.ErrCode, e.DebugData)
}
func http2isEOFOrNetReadError(err error) bool {
if err == io.EOF {
return true
}
ne, ok := err.(*net.OpError)
return ok && ne.Op == "read"
}
func (rl *http2clientConnReadLoop) cleanup() {
cc := rl.cc
defer cc.tconn.Close()
defer cc.t.connPool().MarkDead(cc)
defer close(cc.readerDone)
if cc.idleTimer != nil {
cc.idleTimer.Stop()
}
// Close any response bodies if the server closes prematurely.
// TODO: also do this if we've written the headers but not
// gotten a response yet.
err := cc.readerErr
cc.mu.Lock()
if cc.goAway != nil && http2isEOFOrNetReadError(err) {
err = http2GoAwayError{
LastStreamID: cc.goAway.LastStreamID,
ErrCode: cc.goAway.ErrCode,
DebugData: cc.goAwayDebug,
}
} else if err == io.EOF {
err = io.ErrUnexpectedEOF
}
for _, cs := range cc.streams {
cs.bufPipe.CloseWithError(err) // no-op if already closed
select {
case cs.resc <- http2resAndError{err: err}:
default:
}
close(cs.done)
}
cc.closed = true
cc.cond.Broadcast()
cc.mu.Unlock()
}
func (rl *http2clientConnReadLoop) run() error {
cc := rl.cc
rl.closeWhenIdle = cc.t.disableKeepAlives() || cc.singleUse
gotReply := false // ever saw a HEADERS reply
gotSettings := false
for {
f, err := cc.fr.ReadFrame()
if err != nil {
cc.vlogf("http2: Transport readFrame error on conn %p: (%T) %v", cc, err, err)
}
if se, ok := err.(http2StreamError); ok {
if cs := cc.streamByID(se.StreamID, false); cs != nil {
cs.cc.writeStreamReset(cs.ID, se.Code, err)
cs.cc.forgetStreamID(cs.ID)
if se.Cause == nil {
se.Cause = cc.fr.errDetail
}
rl.endStreamError(cs, se)
}
continue
} else if err != nil {
return err
}
if http2VerboseLogs {
cc.vlogf("http2: Transport received %s", http2summarizeFrame(f))
}
if !gotSettings {
if _, ok := f.(*http2SettingsFrame); !ok {
cc.logf("protocol error: received %T before a SETTINGS frame", f)
return http2ConnectionError(http2ErrCodeProtocol)
}
gotSettings = true
}
maybeIdle := false // whether frame might transition us to idle
switch f := f.(type) {
case *http2MetaHeadersFrame:
err = rl.processHeaders(f)
maybeIdle = true
gotReply = true
case *http2DataFrame:
err = rl.processData(f)
maybeIdle = true
case *http2GoAwayFrame:
err = rl.processGoAway(f)
maybeIdle = true
case *http2RSTStreamFrame:
err = rl.processResetStream(f)
maybeIdle = true
case *http2SettingsFrame:
err = rl.processSettings(f)
case *http2PushPromiseFrame:
err = rl.processPushPromise(f)
case *http2WindowUpdateFrame:
err = rl.processWindowUpdate(f)
case *http2PingFrame:
err = rl.processPing(f)
default:
cc.logf("Transport: unhandled response frame type %T", f)
}
if err != nil {
if http2VerboseLogs {
cc.vlogf("http2: Transport conn %p received error from processing frame %v: %v", cc, http2summarizeFrame(f), err)
}
return err
}
if rl.closeWhenIdle && gotReply && maybeIdle {
cc.closeIfIdle()
}
}
}
func (rl *http2clientConnReadLoop) processHeaders(f *http2MetaHeadersFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, false)
if cs == nil {
// We'd get here if we canceled a request while the
// server had its response still in flight. So if this
// was just something we canceled, ignore it.
return nil
}
if f.StreamEnded() {
// Issue 20521: If the stream has ended, streamByID() causes
// clientStream.done to be closed, which causes the request's bodyWriter
// to be closed with an errStreamClosed, which may be received by
// clientConn.RoundTrip before the result of processing these headers.
// Deferring stream closure allows the header processing to occur first.
// clientConn.RoundTrip may still receive the bodyWriter error first, but
// the fix for issue 16102 prioritises any response.
//
// Issue 22413: If there is no request body, we should close the
// stream before writing to cs.resc so that the stream is closed
// immediately once RoundTrip returns.
if cs.req.Body != nil {
defer cc.forgetStreamID(f.StreamID)
} else {
cc.forgetStreamID(f.StreamID)
}
}
if !cs.firstByte {
if cs.trace != nil {
// TODO(bradfitz): move first response byte earlier,
// when we first read the 9 byte header, not waiting
// until all the HEADERS+CONTINUATION frames have been
// merged. This works for now.
http2traceFirstResponseByte(cs.trace)
}
cs.firstByte = true
}
if !cs.pastHeaders {
cs.pastHeaders = true
} else {
return rl.processTrailers(cs, f)
}
res, err := rl.handleResponse(cs, f)
if err != nil {
if _, ok := err.(http2ConnectionError); ok {
return err
}
// Any other error type is a stream error.
cs.cc.writeStreamReset(f.StreamID, http2ErrCodeProtocol, err)
cc.forgetStreamID(cs.ID)
cs.resc <- http2resAndError{err: err}
return nil // return nil from process* funcs to keep conn alive
}
if res == nil {
// (nil, nil) special case. See handleResponse docs.
return nil
}
cs.resTrailer = &res.Trailer
cs.resc <- http2resAndError{res: res}
return nil
}
// may return error types nil, or ConnectionError. Any other error value
// is a StreamError of type ErrCodeProtocol. The returned error in that case
// is the detail.
//
// As a special case, handleResponse may return (nil, nil) to skip the
// frame (currently only used for 1xx responses).
func (rl *http2clientConnReadLoop) handleResponse(cs *http2clientStream, f *http2MetaHeadersFrame) (*Response, error) {
if f.Truncated {
return nil, http2errResponseHeaderListSize
}
status := f.PseudoValue("status")
if status == "" {
return nil, errors.New("malformed response from server: missing status pseudo header")
}
statusCode, err := strconv.Atoi(status)
if err != nil {
return nil, errors.New("malformed response from server: malformed non-numeric status pseudo header")
}
header := make(Header)
res := &Response{
Proto: "HTTP/2.0",
ProtoMajor: 2,
Header: header,
StatusCode: statusCode,
Status: status + " " + StatusText(statusCode),
}
for _, hf := range f.RegularFields() {
key := CanonicalHeaderKey(hf.Name)
if key == "Trailer" {
t := res.Trailer
if t == nil {
t = make(Header)
res.Trailer = t
}
http2foreachHeaderElement(hf.Value, func(v string) {
t[CanonicalHeaderKey(v)] = nil
})
} else {
header[key] = append(header[key], hf.Value)
}
}
if statusCode >= 100 && statusCode <= 199 {
cs.num1xx++
const max1xxResponses = 5 // arbitrary bound on number of informational responses, same as net/http
if cs.num1xx > max1xxResponses {
return nil, errors.New("http2: too many 1xx informational responses")
}
if fn := cs.get1xxTraceFunc(); fn != nil {
if err := fn(statusCode, textproto.MIMEHeader(header)); err != nil {
return nil, err
}
}
if statusCode == 100 {
http2traceGot100Continue(cs.trace)
if cs.on100 != nil {
cs.on100() // forces any write delay timer to fire
}
}
cs.pastHeaders = false // do it all again
return nil, nil
}
streamEnded := f.StreamEnded()
isHead := cs.req.Method == "HEAD"
if !streamEnded || isHead {
res.ContentLength = -1
if clens := res.Header["Content-Length"]; len(clens) == 1 {
if clen64, err := strconv.ParseInt(clens[0], 10, 64); err == nil {
res.ContentLength = clen64
} else {
// TODO: care? unlike http/1, it won't mess up our framing, so it's
// more safe smuggling-wise to ignore.
}
} else if len(clens) > 1 {
// TODO: care? unlike http/1, it won't mess up our framing, so it's
// more safe smuggling-wise to ignore.
}
}
if streamEnded || isHead {
res.Body = http2noBody
return res, nil
}
cs.bufPipe = http2pipe{b: &http2dataBuffer{expected: res.ContentLength}}
cs.bytesRemain = res.ContentLength
res.Body = http2transportResponseBody{cs}
go cs.awaitRequestCancel(cs.req)
if cs.requestedGzip && res.Header.Get("Content-Encoding") == "gzip" {
res.Header.Del("Content-Encoding")
res.Header.Del("Content-Length")
res.ContentLength = -1
res.Body = &http2gzipReader{body: res.Body}
res.Uncompressed = true
}
return res, nil
}
func (rl *http2clientConnReadLoop) processTrailers(cs *http2clientStream, f *http2MetaHeadersFrame) error {
if cs.pastTrailers {
// Too many HEADERS frames for this stream.
return http2ConnectionError(http2ErrCodeProtocol)
}
cs.pastTrailers = true
if !f.StreamEnded() {
// We expect that any headers for trailers also
// has END_STREAM.
return http2ConnectionError(http2ErrCodeProtocol)
}
if len(f.PseudoFields()) > 0 {
// No pseudo header fields are defined for trailers.
// TODO: ConnectionError might be overly harsh? Check.
return http2ConnectionError(http2ErrCodeProtocol)
}
trailer := make(Header)
for _, hf := range f.RegularFields() {
key := CanonicalHeaderKey(hf.Name)
trailer[key] = append(trailer[key], hf.Value)
}
cs.trailer = trailer
rl.endStream(cs)
return nil
}
// transportResponseBody is the concrete type of Transport.RoundTrip's
// Response.Body. It is an io.ReadCloser. On Read, it reads from cs.body.
// On Close it sends RST_STREAM if EOF wasn't already seen.
type http2transportResponseBody struct {
cs *http2clientStream
}
func (b http2transportResponseBody) Read(p []byte) (n int, err error) {
cs := b.cs
cc := cs.cc
if cs.readErr != nil {
return 0, cs.readErr
}
n, err = b.cs.bufPipe.Read(p)
if cs.bytesRemain != -1 {
if int64(n) > cs.bytesRemain {
n = int(cs.bytesRemain)
if err == nil {
err = errors.New("net/http: server replied with more than declared Content-Length; truncated")
cc.writeStreamReset(cs.ID, http2ErrCodeProtocol, err)
}
cs.readErr = err
return int(cs.bytesRemain), err
}
cs.bytesRemain -= int64(n)
if err == io.EOF && cs.bytesRemain > 0 {
err = io.ErrUnexpectedEOF
cs.readErr = err
return n, err
}
}
if n == 0 {
// No flow control tokens to send back.
return
}
cc.mu.Lock()
defer cc.mu.Unlock()
var connAdd, streamAdd int32
// Check the conn-level first, before the stream-level.
if v := cc.inflow.available(); v < http2transportDefaultConnFlow/2 {
connAdd = http2transportDefaultConnFlow - v
cc.inflow.add(connAdd)
}
if err == nil { // No need to refresh if the stream is over or failed.
// Consider any buffered body data (read from the conn but not
// consumed by the client) when computing flow control for this
// stream.
v := int(cs.inflow.available()) + cs.bufPipe.Len()
if v < http2transportDefaultStreamFlow-http2transportDefaultStreamMinRefresh {
streamAdd = int32(http2transportDefaultStreamFlow - v)
cs.inflow.add(streamAdd)
}
}
if connAdd != 0 || streamAdd != 0 {
cc.wmu.Lock()
defer cc.wmu.Unlock()
if connAdd != 0 {
cc.fr.WriteWindowUpdate(0, http2mustUint31(connAdd))
}
if streamAdd != 0 {
cc.fr.WriteWindowUpdate(cs.ID, http2mustUint31(streamAdd))
}
cc.bw.Flush()
}
return
}
var http2errClosedResponseBody = errors.New("http2: response body closed")
func (b http2transportResponseBody) Close() error {
cs := b.cs
cc := cs.cc
serverSentStreamEnd := cs.bufPipe.Err() == io.EOF
unread := cs.bufPipe.Len()
if unread > 0 || !serverSentStreamEnd {
cc.mu.Lock()
cc.wmu.Lock()
if !serverSentStreamEnd {
cc.fr.WriteRSTStream(cs.ID, http2ErrCodeCancel)
cs.didReset = true
}
// Return connection-level flow control.
if unread > 0 {
cc.inflow.add(int32(unread))
cc.fr.WriteWindowUpdate(0, uint32(unread))
}
cc.bw.Flush()
cc.wmu.Unlock()
cc.mu.Unlock()
}
cs.bufPipe.BreakWithError(http2errClosedResponseBody)
cc.forgetStreamID(cs.ID)
return nil
}
func (rl *http2clientConnReadLoop) processData(f *http2DataFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, f.StreamEnded())
data := f.Data()
if cs == nil {
cc.mu.Lock()
neverSent := cc.nextStreamID
cc.mu.Unlock()
if f.StreamID >= neverSent {
// We never asked for this.
cc.logf("http2: Transport received unsolicited DATA frame; closing connection")
return http2ConnectionError(http2ErrCodeProtocol)
}
// We probably did ask for this, but canceled. Just ignore it.
// TODO: be stricter here? only silently ignore things which
// we canceled, but not things which were closed normally
// by the peer? Tough without accumulating too much state.
// But at least return their flow control:
if f.Length > 0 {
cc.mu.Lock()
cc.inflow.add(int32(f.Length))
cc.mu.Unlock()
cc.wmu.Lock()
cc.fr.WriteWindowUpdate(0, uint32(f.Length))
cc.bw.Flush()
cc.wmu.Unlock()
}
return nil
}
if !cs.firstByte {
cc.logf("protocol error: received DATA before a HEADERS frame")
rl.endStreamError(cs, http2StreamError{
StreamID: f.StreamID,
Code: http2ErrCodeProtocol,
})
return nil
}
if f.Length > 0 {
if cs.req.Method == "HEAD" && len(data) > 0 {
cc.logf("protocol error: received DATA on a HEAD request")
rl.endStreamError(cs, http2StreamError{
StreamID: f.StreamID,
Code: http2ErrCodeProtocol,
})
return nil
}
// Check connection-level flow control.
cc.mu.Lock()
if cs.inflow.available() >= int32(f.Length) {
cs.inflow.take(int32(f.Length))
} else {
cc.mu.Unlock()
return http2ConnectionError(http2ErrCodeFlowControl)
}
// Return any padded flow control now, since we won't
// refund it later on body reads.
var refund int
if pad := int(f.Length) - len(data); pad > 0 {
refund += pad
}
// Return len(data) now if the stream is already closed,
// since data will never be read.
didReset := cs.didReset
if didReset {
refund += len(data)
}
if refund > 0 {
cc.inflow.add(int32(refund))
cc.wmu.Lock()
cc.fr.WriteWindowUpdate(0, uint32(refund))
if !didReset {
cs.inflow.add(int32(refund))
cc.fr.WriteWindowUpdate(cs.ID, uint32(refund))
}
cc.bw.Flush()
cc.wmu.Unlock()
}
cc.mu.Unlock()
if len(data) > 0 && !didReset {
if _, err := cs.bufPipe.Write(data); err != nil {
rl.endStreamError(cs, err)
return err
}
}
}
if f.StreamEnded() {
rl.endStream(cs)
}
return nil
}
var http2errInvalidTrailers = errors.New("http2: invalid trailers")
func (rl *http2clientConnReadLoop) endStream(cs *http2clientStream) {
// TODO: check that any declared content-length matches, like
// server.go's (*stream).endStream method.
rl.endStreamError(cs, nil)
}
func (rl *http2clientConnReadLoop) endStreamError(cs *http2clientStream, err error) {
var code func()
if err == nil {
err = io.EOF
code = cs.copyTrailers
}
if http2isConnectionCloseRequest(cs.req) {
rl.closeWhenIdle = true
}
cs.bufPipe.closeWithErrorAndCode(err, code)
select {
case cs.resc <- http2resAndError{err: err}:
default:
}
}
func (cs *http2clientStream) copyTrailers() {
for k, vv := range cs.trailer {
t := cs.resTrailer
if *t == nil {
*t = make(Header)
}
(*t)[k] = vv
}
}
func (rl *http2clientConnReadLoop) processGoAway(f *http2GoAwayFrame) error {
cc := rl.cc
cc.t.connPool().MarkDead(cc)
if f.ErrCode != 0 {
// TODO: deal with GOAWAY more. particularly the error code
cc.vlogf("transport got GOAWAY with error code = %v", f.ErrCode)
}
cc.setGoAway(f)
return nil
}
func (rl *http2clientConnReadLoop) processSettings(f *http2SettingsFrame) error {
cc := rl.cc
cc.mu.Lock()
defer cc.mu.Unlock()
if f.IsAck() {
if cc.wantSettingsAck {
cc.wantSettingsAck = false
return nil
}
return http2ConnectionError(http2ErrCodeProtocol)
}
err := f.ForeachSetting(func(s http2Setting) error {
switch s.ID {
case http2SettingMaxFrameSize:
cc.maxFrameSize = s.Val
case http2SettingMaxConcurrentStreams:
cc.maxConcurrentStreams = s.Val
case http2SettingMaxHeaderListSize:
cc.peerMaxHeaderListSize = uint64(s.Val)
case http2SettingInitialWindowSize:
// Values above the maximum flow-control
// window size of 2^31-1 MUST be treated as a
// connection error (Section 5.4.1) of type
// FLOW_CONTROL_ERROR.
if s.Val > math.MaxInt32 {
return http2ConnectionError(http2ErrCodeFlowControl)
}
// Adjust flow control of currently-open
// frames by the difference of the old initial
// window size and this one.
delta := int32(s.Val) - int32(cc.initialWindowSize)
for _, cs := range cc.streams {
cs.flow.add(delta)
}
cc.cond.Broadcast()
cc.initialWindowSize = s.Val
default:
// TODO(bradfitz): handle more settings? SETTINGS_HEADER_TABLE_SIZE probably.
cc.vlogf("Unhandled Setting: %v", s)
}
return nil
})
if err != nil {
return err
}
cc.wmu.Lock()
defer cc.wmu.Unlock()
cc.fr.WriteSettingsAck()
cc.bw.Flush()
return cc.werr
}
func (rl *http2clientConnReadLoop) processWindowUpdate(f *http2WindowUpdateFrame) error {
cc := rl.cc
cs := cc.streamByID(f.StreamID, false)
if f.StreamID != 0 && cs == nil {
return nil
}
cc.mu.Lock()
defer cc.mu.Unlock()
fl := &cc.flow
if cs != nil {
fl = &cs.flow
}
if !fl.add(int32(f.Increment)) {
return http2ConnectionError(http2ErrCodeFlowControl)
}
cc.cond.Broadcast()
return nil
}
func (rl *http2clientConnReadLoop) processResetStream(f *http2RSTStreamFrame) error {
cs := rl.cc.streamByID(f.StreamID, true)
if cs == nil {
// TODO: return error if server tries to RST_STEAM an idle stream
return nil
}
select {
case <-cs.peerReset:
// Already reset.
// This is the only goroutine
// which closes this, so there
// isn't a race.
default:
err := http2streamError(cs.ID, f.ErrCode)
cs.resetErr = err
close(cs.peerReset)
cs.bufPipe.CloseWithError(err)
cs.cc.cond.Broadcast() // wake up checkResetOrDone via clientStream.awaitFlowControl
}
return nil
}
// Ping sends a PING frame to the server and waits for the ack.
func (cc *http2ClientConn) Ping(ctx context.Context) error {
c := make(chan struct{})
// Generate a random payload
var p [8]byte
for {
if _, err := rand.Read(p[:]); err != nil {
return err
}
cc.mu.Lock()
// check for dup before insert
if _, found := cc.pings[p]; !found {
cc.pings[p] = c
cc.mu.Unlock()
break
}
cc.mu.Unlock()
}
cc.wmu.Lock()
if err := cc.fr.WritePing(false, p); err != nil {
cc.wmu.Unlock()
return err
}
if err := cc.bw.Flush(); err != nil {
cc.wmu.Unlock()
return err
}
cc.wmu.Unlock()
select {
case <-c:
return nil
case <-ctx.Done():
return ctx.Err()
case <-cc.readerDone:
// connection closed
return cc.readerErr
}
}
func (rl *http2clientConnReadLoop) processPing(f *http2PingFrame) error {
if f.IsAck() {
cc := rl.cc
cc.mu.Lock()
defer cc.mu.Unlock()
// If ack, notify listener if any
if c, ok := cc.pings[f.Data]; ok {
close(c)
delete(cc.pings, f.Data)
}
return nil
}
cc := rl.cc
cc.wmu.Lock()
defer cc.wmu.Unlock()
if err := cc.fr.WritePing(true, f.Data); err != nil {
return err
}
return cc.bw.Flush()
}
func (rl *http2clientConnReadLoop) processPushPromise(f *http2PushPromiseFrame) error {
// We told the peer we don't want them.
// Spec says:
// "PUSH_PROMISE MUST NOT be sent if the SETTINGS_ENABLE_PUSH
// setting of the peer endpoint is set to 0. An endpoint that
// has set this setting and has received acknowledgement MUST
// treat the receipt of a PUSH_PROMISE frame as a connection
// error (Section 5.4.1) of type PROTOCOL_ERROR."
return http2ConnectionError(http2ErrCodeProtocol)
}
func (cc *http2ClientConn) writeStreamReset(streamID uint32, code http2ErrCode, err error) {
// TODO: map err to more interesting error codes, once the
// HTTP community comes up with some. But currently for
// RST_STREAM there's no equivalent to GOAWAY frame's debug
// data, and the error codes are all pretty vague ("cancel").
cc.wmu.Lock()
cc.fr.WriteRSTStream(streamID, code)
cc.bw.Flush()
cc.wmu.Unlock()
}
var (
http2errResponseHeaderListSize = errors.New("http2: response header list larger than advertised limit")
http2errRequestHeaderListSize = errors.New("http2: request header list larger than peer's advertised limit")
http2errPseudoTrailers = errors.New("http2: invalid pseudo header in trailers")
)
func (cc *http2ClientConn) logf(format string, args ...interface{}) {
cc.t.logf(format, args...)
}
func (cc *http2ClientConn) vlogf(format string, args ...interface{}) {
cc.t.vlogf(format, args...)
}
func (t *http2Transport) vlogf(format string, args ...interface{}) {
if http2VerboseLogs {
t.logf(format, args...)
}
}
func (t *http2Transport) logf(format string, args ...interface{}) {
log.Printf(format, args...)
}
var http2noBody io.ReadCloser = ioutil.NopCloser(bytes.NewReader(nil))
func http2strSliceContains(ss []string, s string) bool {
for _, v := range ss {
if v == s {
return true
}
}
return false
}
type http2erringRoundTripper struct{ err error }
func (rt http2erringRoundTripper) RoundTrip(*Request) (*Response, error) { return nil, rt.err }
// gzipReader wraps a response body so it can lazily
// call gzip.NewReader on the first call to Read
type http2gzipReader struct {
body io.ReadCloser // underlying Response.Body
zr *gzip.Reader // lazily-initialized gzip reader
zerr error // sticky error
}
func (gz *http2gzipReader) Read(p []byte) (n int, err error) {
if gz.zerr != nil {
return 0, gz.zerr
}
if gz.zr == nil {
gz.zr, err = gzip.NewReader(gz.body)
if err != nil {
gz.zerr = err
return 0, err
}
}
return gz.zr.Read(p)
}
func (gz *http2gzipReader) Close() error {
return gz.body.Close()
}
type http2errorReader struct{ err error }
func (r http2errorReader) Read(p []byte) (int, error) { return 0, r.err }
// bodyWriterState encapsulates various state around the Transport's writing
// of the request body, particularly regarding doing delayed writes of the body
// when the request contains "Expect: 100-continue".
type http2bodyWriterState struct {
cs *http2clientStream
timer *time.Timer // if non-nil, we're doing a delayed write
fnonce *sync.Once // to call fn with
fn func() // the code to run in the goroutine, writing the body
resc chan error // result of fn's execution
delay time.Duration // how long we should delay a delayed write for
}
func (t *http2Transport) getBodyWriterState(cs *http2clientStream, body io.Reader) (s http2bodyWriterState) {
s.cs = cs
if body == nil {
return
}
resc := make(chan error, 1)
s.resc = resc
s.fn = func() {
cs.cc.mu.Lock()
cs.startedWrite = true
cs.cc.mu.Unlock()
resc <- cs.writeRequestBody(body, cs.req.Body)
}
s.delay = t.expectContinueTimeout()
if s.delay == 0 ||
!httpguts.HeaderValuesContainsToken(
cs.req.Header["Expect"],
"100-continue") {
return
}
s.fnonce = new(sync.Once)
// Arm the timer with a very large duration, which we'll
// intentionally lower later. It has to be large now because
// we need a handle to it before writing the headers, but the
// s.delay value is defined to not start until after the
// request headers were written.
const hugeDuration = 365 * 24 * time.Hour
s.timer = time.AfterFunc(hugeDuration, func() {
s.fnonce.Do(s.fn)
})
return
}
func (s http2bodyWriterState) cancel() {
if s.timer != nil {
s.timer.Stop()
}
}
func (s http2bodyWriterState) on100() {
if s.timer == nil {
// If we didn't do a delayed write, ignore the server's
// bogus 100 continue response.
return
}
s.timer.Stop()
go func() { s.fnonce.Do(s.fn) }()
}
// scheduleBodyWrite starts writing the body, either immediately (in
// the common case) or after the delay timeout. It should not be
// called until after the headers have been written.
func (s http2bodyWriterState) scheduleBodyWrite() {
if s.timer == nil {
// We're not doing a delayed write (see
// getBodyWriterState), so just start the writing
// goroutine immediately.
go s.fn()
return
}
http2traceWait100Continue(s.cs.trace)
if s.timer.Stop() {
s.timer.Reset(s.delay)
}
}
// isConnectionCloseRequest reports whether req should use its own
// connection for a single request and then close the connection.
func http2isConnectionCloseRequest(req *Request) bool {
return req.Close || httpguts.HeaderValuesContainsToken(req.Header["Connection"], "close")
}
// registerHTTPSProtocol calls Transport.RegisterProtocol but
// converting panics into errors.
func http2registerHTTPSProtocol(t *Transport, rt http2noDialH2RoundTripper) (err error) {
defer func() {
if e := recover(); e != nil {
err = fmt.Errorf("%v", e)
}
}()
t.RegisterProtocol("https", rt)
return nil
}
// noDialH2RoundTripper is a RoundTripper which only tries to complete the request
// if there's already has a cached connection to the host.
// (The field is exported so it can be accessed via reflect from net/http; tested
// by TestNoDialH2RoundTripperType)
type http2noDialH2RoundTripper struct{ *http2Transport }
func (rt http2noDialH2RoundTripper) RoundTrip(req *Request) (*Response, error) {
res, err := rt.http2Transport.RoundTrip(req)
if http2isNoCachedConnError(err) {
return nil, ErrSkipAltProtocol
}
return res, err
}
func (t *http2Transport) idleConnTimeout() time.Duration {
if t.t1 != nil {
return t.t1.IdleConnTimeout
}
return 0
}
func http2traceGetConn(req *Request, hostPort string) {
trace := httptrace.ContextClientTrace(req.Context())
if trace == nil || trace.GetConn == nil {
return
}
trace.GetConn(hostPort)
}
func http2traceGotConn(req *Request, cc *http2ClientConn) {
trace := httptrace.ContextClientTrace(req.Context())
if trace == nil || trace.GotConn == nil {
return
}
ci := httptrace.GotConnInfo{Conn: cc.tconn}
cc.mu.Lock()
ci.Reused = cc.nextStreamID > 1
ci.WasIdle = len(cc.streams) == 0 && ci.Reused
if ci.WasIdle && !cc.lastActive.IsZero() {
ci.IdleTime = time.Now().Sub(cc.lastActive)
}
cc.mu.Unlock()
trace.GotConn(ci)
}
func http2traceWroteHeaders(trace *httptrace.ClientTrace) {
if trace != nil && trace.WroteHeaders != nil {
trace.WroteHeaders()
}
}
func http2traceGot100Continue(trace *httptrace.ClientTrace) {
if trace != nil && trace.Got100Continue != nil {
trace.Got100Continue()
}
}
func http2traceWait100Continue(trace *httptrace.ClientTrace) {
if trace != nil && trace.Wait100Continue != nil {
trace.Wait100Continue()
}
}
func http2traceWroteRequest(trace *httptrace.ClientTrace, err error) {
if trace != nil && trace.WroteRequest != nil {
trace.WroteRequest(httptrace.WroteRequestInfo{Err: err})
}
}
func http2traceFirstResponseByte(trace *httptrace.ClientTrace) {
if trace != nil && trace.GotFirstResponseByte != nil {
trace.GotFirstResponseByte()
}
}
// writeFramer is implemented by any type that is used to write frames.
type http2writeFramer interface {
writeFrame(http2writeContext) error
// staysWithinBuffer reports whether this writer promises that
// it will only write less than or equal to size bytes, and it
// won't Flush the write context.
staysWithinBuffer(size int) bool
}
// writeContext is the interface needed by the various frame writer
// types below. All the writeFrame methods below are scheduled via the
// frame writing scheduler (see writeScheduler in writesched.go).
//
// This interface is implemented by *serverConn.
//
// TODO: decide whether to a) use this in the client code (which didn't
// end up using this yet, because it has a simpler design, not
// currently implementing priorities), or b) delete this and
// make the server code a bit more concrete.
type http2writeContext interface {
Framer() *http2Framer
Flush() error
CloseConn() error
// HeaderEncoder returns an HPACK encoder that writes to the
// returned buffer.
HeaderEncoder() (*hpack.Encoder, *bytes.Buffer)
}
// writeEndsStream reports whether w writes a frame that will transition
// the stream to a half-closed local state. This returns false for RST_STREAM,
// which closes the entire stream (not just the local half).
func http2writeEndsStream(w http2writeFramer) bool {
switch v := w.(type) {
case *http2writeData:
return v.endStream
case *http2writeResHeaders:
return v.endStream
case nil:
// This can only happen if the caller reuses w after it's
// been intentionally nil'ed out to prevent use. Keep this
// here to catch future refactoring breaking it.
panic("writeEndsStream called on nil writeFramer")
}
return false
}
type http2flushFrameWriter struct{}
func (http2flushFrameWriter) writeFrame(ctx http2writeContext) error {
return ctx.Flush()
}
func (http2flushFrameWriter) staysWithinBuffer(max int) bool { return false }
type http2writeSettings []http2Setting
func (s http2writeSettings) staysWithinBuffer(max int) bool {
const settingSize = 6 // uint16 + uint32
return http2frameHeaderLen+settingSize*len(s) <= max
}
func (s http2writeSettings) writeFrame(ctx http2writeContext) error {
return ctx.Framer().WriteSettings([]http2Setting(s)...)
}
type http2writeGoAway struct {
maxStreamID uint32
code http2ErrCode
}
func (p *http2writeGoAway) writeFrame(ctx http2writeContext) error {
err := ctx.Framer().WriteGoAway(p.maxStreamID, p.code, nil)
ctx.Flush() // ignore error: we're hanging up on them anyway
return err
}
func (*http2writeGoAway) staysWithinBuffer(max int) bool { return false } // flushes
type http2writeData struct {
streamID uint32
p []byte
endStream bool
}
func (w *http2writeData) String() string {
return fmt.Sprintf("writeData(stream=%d, p=%d, endStream=%v)", w.streamID, len(w.p), w.endStream)
}
func (w *http2writeData) writeFrame(ctx http2writeContext) error {
return ctx.Framer().WriteData(w.streamID, w.endStream, w.p)
}
func (w *http2writeData) staysWithinBuffer(max int) bool {
return http2frameHeaderLen+len(w.p) <= max
}
// handlerPanicRST is the message sent from handler goroutines when
// the handler panics.
type http2handlerPanicRST struct {
StreamID uint32
}
func (hp http2handlerPanicRST) writeFrame(ctx http2writeContext) error {
return ctx.Framer().WriteRSTStream(hp.StreamID, http2ErrCodeInternal)
}
func (hp http2handlerPanicRST) staysWithinBuffer(max int) bool { return http2frameHeaderLen+4 <= max }
func (se http2StreamError) writeFrame(ctx http2writeContext) error {
return ctx.Framer().WriteRSTStream(se.StreamID, se.Code)
}
func (se http2StreamError) staysWithinBuffer(max int) bool { return http2frameHeaderLen+4 <= max }
type http2writePingAck struct{ pf *http2PingFrame }
func (w http2writePingAck) writeFrame(ctx http2writeContext) error {
return ctx.Framer().WritePing(true, w.pf.Data)
}
func (w http2writePingAck) staysWithinBuffer(max int) bool {
return http2frameHeaderLen+len(w.pf.Data) <= max
}
type http2writeSettingsAck struct{}
func (http2writeSettingsAck) writeFrame(ctx http2writeContext) error {
return ctx.Framer().WriteSettingsAck()
}
func (http2writeSettingsAck) staysWithinBuffer(max int) bool { return http2frameHeaderLen <= max }
// splitHeaderBlock splits headerBlock into fragments so that each fragment fits
// in a single frame, then calls fn for each fragment. firstFrag/lastFrag are true
// for the first/last fragment, respectively.
func http2splitHeaderBlock(ctx http2writeContext, headerBlock []byte, fn func(ctx http2writeContext, frag []byte, firstFrag, lastFrag bool) error) error {
// For now we're lazy and just pick the minimum MAX_FRAME_SIZE
// that all peers must support (16KB). Later we could care
// more and send larger frames if the peer advertised it, but
// there's little point. Most headers are small anyway (so we
// generally won't have CONTINUATION frames), and extra frames
// only waste 9 bytes anyway.
const maxFrameSize = 16384
first := true
for len(headerBlock) > 0 {
frag := headerBlock
if len(frag) > maxFrameSize {
frag = frag[:maxFrameSize]
}
headerBlock = headerBlock[len(frag):]
if err := fn(ctx, frag, first, len(headerBlock) == 0); err != nil {
return err
}
first = false
}
return nil
}
// writeResHeaders is a request to write a HEADERS and 0+ CONTINUATION frames
// for HTTP response headers or trailers from a server handler.
type http2writeResHeaders struct {
streamID uint32
httpResCode int // 0 means no ":status" line
h Header // may be nil
trailers []string // if non-nil, which keys of h to write. nil means all.
endStream bool
date string
contentType string
contentLength string
}
func http2encKV(enc *hpack.Encoder, k, v string) {
if http2VerboseLogs {
log.Printf("http2: server encoding header %q = %q", k, v)
}
enc.WriteField(hpack.HeaderField{Name: k, Value: v})
}
func (w *http2writeResHeaders) staysWithinBuffer(max int) bool {
// TODO: this is a common one. It'd be nice to return true
// here and get into the fast path if we could be clever and
// calculate the size fast enough, or at least a conservative
// upper bound that usually fires. (Maybe if w.h and
// w.trailers are nil, so we don't need to enumerate it.)
// Otherwise I'm afraid that just calculating the length to
// answer this question would be slower than the ~2µs benefit.
return false
}
func (w *http2writeResHeaders) writeFrame(ctx http2writeContext) error {
enc, buf := ctx.HeaderEncoder()
buf.Reset()
if w.httpResCode != 0 {
http2encKV(enc, ":status", http2httpCodeString(w.httpResCode))
}
http2encodeHeaders(enc, w.h, w.trailers)
if w.contentType != "" {
http2encKV(enc, "content-type", w.contentType)
}
if w.contentLength != "" {
http2encKV(enc, "content-length", w.contentLength)
}
if w.date != "" {
http2encKV(enc, "date", w.date)
}
headerBlock := buf.Bytes()
if len(headerBlock) == 0 && w.trailers == nil {
panic("unexpected empty hpack")
}
return http2splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock)
}
func (w *http2writeResHeaders) writeHeaderBlock(ctx http2writeContext, frag []byte, firstFrag, lastFrag bool) error {
if firstFrag {
return ctx.Framer().WriteHeaders(http2HeadersFrameParam{
StreamID: w.streamID,
BlockFragment: frag,
EndStream: w.endStream,
EndHeaders: lastFrag,
})
} else {
return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag)
}
}
// writePushPromise is a request to write a PUSH_PROMISE and 0+ CONTINUATION frames.
type http2writePushPromise struct {
streamID uint32 // pusher stream
method string // for :method
url *url.URL // for :scheme, :authority, :path
h Header
// Creates an ID for a pushed stream. This runs on serveG just before
// the frame is written. The returned ID is copied to promisedID.
allocatePromisedID func() (uint32, error)
promisedID uint32
}
func (w *http2writePushPromise) staysWithinBuffer(max int) bool {
// TODO: see writeResHeaders.staysWithinBuffer
return false
}
func (w *http2writePushPromise) writeFrame(ctx http2writeContext) error {
enc, buf := ctx.HeaderEncoder()
buf.Reset()
http2encKV(enc, ":method", w.method)
http2encKV(enc, ":scheme", w.url.Scheme)
http2encKV(enc, ":authority", w.url.Host)
http2encKV(enc, ":path", w.url.RequestURI())
http2encodeHeaders(enc, w.h, nil)
headerBlock := buf.Bytes()
if len(headerBlock) == 0 {
panic("unexpected empty hpack")
}
return http2splitHeaderBlock(ctx, headerBlock, w.writeHeaderBlock)
}
func (w *http2writePushPromise) writeHeaderBlock(ctx http2writeContext, frag []byte, firstFrag, lastFrag bool) error {
if firstFrag {
return ctx.Framer().WritePushPromise(http2PushPromiseParam{
StreamID: w.streamID,
PromiseID: w.promisedID,
BlockFragment: frag,
EndHeaders: lastFrag,
})
} else {
return ctx.Framer().WriteContinuation(w.streamID, lastFrag, frag)
}
}
type http2write100ContinueHeadersFrame struct {
streamID uint32
}
func (w http2write100ContinueHeadersFrame) writeFrame(ctx http2writeContext) error {
enc, buf := ctx.HeaderEncoder()
buf.Reset()
http2encKV(enc, ":status", "100")
return ctx.Framer().WriteHeaders(http2HeadersFrameParam{
StreamID: w.streamID,
BlockFragment: buf.Bytes(),
EndStream: false,
EndHeaders: true,
})
}
func (w http2write100ContinueHeadersFrame) staysWithinBuffer(max int) bool {
// Sloppy but conservative:
return 9+2*(len(":status")+len("100")) <= max
}
type http2writeWindowUpdate struct {
streamID uint32 // or 0 for conn-level
n uint32
}
func (wu http2writeWindowUpdate) staysWithinBuffer(max int) bool { return http2frameHeaderLen+4 <= max }
func (wu http2writeWindowUpdate) writeFrame(ctx http2writeContext) error {
return ctx.Framer().WriteWindowUpdate(wu.streamID, wu.n)
}
// encodeHeaders encodes an http.Header. If keys is not nil, then (k, h[k])
// is encoded only if k is in keys.
func http2encodeHeaders(enc *hpack.Encoder, h Header, keys []string) {
if keys == nil {
sorter := http2sorterPool.Get().(*http2sorter)
// Using defer here, since the returned keys from the
// sorter.Keys method is only valid until the sorter
// is returned:
defer http2sorterPool.Put(sorter)
keys = sorter.Keys(h)
}
for _, k := range keys {
vv := h[k]
k = http2lowerHeader(k)
if !http2validWireHeaderFieldName(k) {
// Skip it as backup paranoia. Per
// golang.org/issue/14048, these should
// already be rejected at a higher level.
continue
}
isTE := k == "transfer-encoding"
for _, v := range vv {
if !httpguts.ValidHeaderFieldValue(v) {
// TODO: return an error? golang.org/issue/14048
// For now just omit it.
continue
}
// TODO: more of "8.1.2.2 Connection-Specific Header Fields"
if isTE && v != "trailers" {
continue
}
http2encKV(enc, k, v)
}
}
}
// WriteScheduler is the interface implemented by HTTP/2 write schedulers.
// Methods are never called concurrently.
type http2WriteScheduler interface {
// OpenStream opens a new stream in the write scheduler.
// It is illegal to call this with streamID=0 or with a streamID that is
// already open -- the call may panic.
OpenStream(streamID uint32, options http2OpenStreamOptions)
// CloseStream closes a stream in the write scheduler. Any frames queued on
// this stream should be discarded. It is illegal to call this on a stream
// that is not open -- the call may panic.
CloseStream(streamID uint32)
// AdjustStream adjusts the priority of the given stream. This may be called
// on a stream that has not yet been opened or has been closed. Note that
// RFC 7540 allows PRIORITY frames to be sent on streams in any state. See:
// https://tools.ietf.org/html/rfc7540#section-5.1
AdjustStream(streamID uint32, priority http2PriorityParam)
// Push queues a frame in the scheduler. In most cases, this will not be
// called with wr.StreamID()!=0 unless that stream is currently open. The one
// exception is RST_STREAM frames, which may be sent on idle or closed streams.
Push(wr http2FrameWriteRequest)
// Pop dequeues the next frame to write. Returns false if no frames can
// be written. Frames with a given wr.StreamID() are Pop'd in the same
// order they are Push'd.
Pop() (wr http2FrameWriteRequest, ok bool)
}
// OpenStreamOptions specifies extra options for WriteScheduler.OpenStream.
type http2OpenStreamOptions struct {
// PusherID is zero if the stream was initiated by the client. Otherwise,
// PusherID names the stream that pushed the newly opened stream.
PusherID uint32
}
// FrameWriteRequest is a request to write a frame.
type http2FrameWriteRequest struct {
// write is the interface value that does the writing, once the
// WriteScheduler has selected this frame to write. The write
// functions are all defined in write.go.
write http2writeFramer
// stream is the stream on which this frame will be written.
// nil for non-stream frames like PING and SETTINGS.
stream *http2stream
// done, if non-nil, must be a buffered channel with space for
// 1 message and is sent the return value from write (or an
// earlier error) when the frame has been written.
done chan error
}
// StreamID returns the id of the stream this frame will be written to.
// 0 is used for non-stream frames such as PING and SETTINGS.
func (wr http2FrameWriteRequest) StreamID() uint32 {
if wr.stream == nil {
if se, ok := wr.write.(http2StreamError); ok {
// (*serverConn).resetStream doesn't set
// stream because it doesn't necessarily have
// one. So special case this type of write
// message.
return se.StreamID
}
return 0
}
return wr.stream.id
}
// DataSize returns the number of flow control bytes that must be consumed
// to write this entire frame. This is 0 for non-DATA frames.
func (wr http2FrameWriteRequest) DataSize() int {
if wd, ok := wr.write.(*http2writeData); ok {
return len(wd.p)
}
return 0
}
// Consume consumes min(n, available) bytes from this frame, where available
// is the number of flow control bytes available on the stream. Consume returns
// 0, 1, or 2 frames, where the integer return value gives the number of frames
// returned.
//
// If flow control prevents consuming any bytes, this returns (_, _, 0). If
// the entire frame was consumed, this returns (wr, _, 1). Otherwise, this
// returns (consumed, rest, 2), where 'consumed' contains the consumed bytes and
// 'rest' contains the remaining bytes. The consumed bytes are deducted from the
// underlying stream's flow control budget.
func (wr http2FrameWriteRequest) Consume(n int32) (http2FrameWriteRequest, http2FrameWriteRequest, int) {
var empty http2FrameWriteRequest
// Non-DATA frames are always consumed whole.
wd, ok := wr.write.(*http2writeData)
if !ok || len(wd.p) == 0 {
return wr, empty, 1
}
// Might need to split after applying limits.
allowed := wr.stream.flow.available()
if n < allowed {
allowed = n
}
if wr.stream.sc.maxFrameSize < allowed {
allowed = wr.stream.sc.maxFrameSize
}
if allowed <= 0 {
return empty, empty, 0
}
if len(wd.p) > int(allowed) {
wr.stream.flow.take(allowed)
consumed := http2FrameWriteRequest{
stream: wr.stream,
write: &http2writeData{
streamID: wd.streamID,
p: wd.p[:allowed],
// Even if the original had endStream set, there
// are bytes remaining because len(wd.p) > allowed,
// so we know endStream is false.
endStream: false,
},
// Our caller is blocking on the final DATA frame, not
// this intermediate frame, so no need to wait.
done: nil,
}
rest := http2FrameWriteRequest{
stream: wr.stream,
write: &http2writeData{
streamID: wd.streamID,
p: wd.p[allowed:],
endStream: wd.endStream,
},
done: wr.done,
}
return consumed, rest, 2
}
// The frame is consumed whole.
// NB: This cast cannot overflow because allowed is <= math.MaxInt32.
wr.stream.flow.take(int32(len(wd.p)))
return wr, empty, 1
}
// String is for debugging only.
func (wr http2FrameWriteRequest) String() string {
var des string
if s, ok := wr.write.(fmt.Stringer); ok {
des = s.String()
} else {
des = fmt.Sprintf("%T", wr.write)
}
return fmt.Sprintf("[FrameWriteRequest stream=%d, ch=%v, writer=%v]", wr.StreamID(), wr.done != nil, des)
}
// replyToWriter sends err to wr.done and panics if the send must block
// This does nothing if wr.done is nil.
func (wr *http2FrameWriteRequest) replyToWriter(err error) {
if wr.done == nil {
return
}
select {
case wr.done <- err:
default:
panic(fmt.Sprintf("unbuffered done channel passed in for type %T", wr.write))
}
wr.write = nil // prevent use (assume it's tainted after wr.done send)
}
// writeQueue is used by implementations of WriteScheduler.
type http2writeQueue struct {
s []http2FrameWriteRequest
}
func (q *http2writeQueue) empty() bool { return len(q.s) == 0 }
func (q *http2writeQueue) push(wr http2FrameWriteRequest) {
q.s = append(q.s, wr)
}
func (q *http2writeQueue) shift() http2FrameWriteRequest {
if len(q.s) == 0 {
panic("invalid use of queue")
}
wr := q.s[0]
// TODO: less copy-happy queue.
copy(q.s, q.s[1:])
q.s[len(q.s)-1] = http2FrameWriteRequest{}
q.s = q.s[:len(q.s)-1]
return wr
}
// consume consumes up to n bytes from q.s[0]. If the frame is
// entirely consumed, it is removed from the queue. If the frame
// is partially consumed, the frame is kept with the consumed
// bytes removed. Returns true iff any bytes were consumed.
func (q *http2writeQueue) consume(n int32) (http2FrameWriteRequest, bool) {
if len(q.s) == 0 {
return http2FrameWriteRequest{}, false
}
consumed, rest, numresult := q.s[0].Consume(n)
switch numresult {
case 0:
return http2FrameWriteRequest{}, false
case 1:
q.shift()
case 2:
q.s[0] = rest
}
return consumed, true
}
type http2writeQueuePool []*http2writeQueue
// put inserts an unused writeQueue into the pool.
// put inserts an unused writeQueue into the pool.
func (p *http2writeQueuePool) put(q *http2writeQueue) {
for i := range q.s {
q.s[i] = http2FrameWriteRequest{}
}
q.s = q.s[:0]
*p = append(*p, q)
}
// get returns an empty writeQueue.
func (p *http2writeQueuePool) get() *http2writeQueue {
ln := len(*p)
if ln == 0 {
return new(http2writeQueue)
}
x := ln - 1
q := (*p)[x]
(*p)[x] = nil
*p = (*p)[:x]
return q
}
// RFC 7540, Section 5.3.5: the default weight is 16.
const http2priorityDefaultWeight = 15 // 16 = 15 + 1
// PriorityWriteSchedulerConfig configures a priorityWriteScheduler.
type http2PriorityWriteSchedulerConfig struct {
// MaxClosedNodesInTree controls the maximum number of closed streams to
// retain in the priority tree. Setting this to zero saves a small amount
// of memory at the cost of performance.
//
// See RFC 7540, Section 5.3.4:
// "It is possible for a stream to become closed while prioritization
// information ... is in transit. ... This potentially creates suboptimal
// prioritization, since the stream could be given a priority that is
// different from what is intended. To avoid these problems, an endpoint
// SHOULD retain stream prioritization state for a period after streams
// become closed. The longer state is retained, the lower the chance that
// streams are assigned incorrect or default priority values."
MaxClosedNodesInTree int
// MaxIdleNodesInTree controls the maximum number of idle streams to
// retain in the priority tree. Setting this to zero saves a small amount
// of memory at the cost of performance.
//
// See RFC 7540, Section 5.3.4:
// Similarly, streams that are in the "idle" state can be assigned
// priority or become a parent of other streams. This allows for the
// creation of a grouping node in the dependency tree, which enables
// more flexible expressions of priority. Idle streams begin with a
// default priority (Section 5.3.5).
MaxIdleNodesInTree int
// ThrottleOutOfOrderWrites enables write throttling to help ensure that
// data is delivered in priority order. This works around a race where
// stream B depends on stream A and both streams are about to call Write
// to queue DATA frames. If B wins the race, a naive scheduler would eagerly
// write as much data from B as possible, but this is suboptimal because A
// is a higher-priority stream. With throttling enabled, we write a small
// amount of data from B to minimize the amount of bandwidth that B can
// steal from A.
ThrottleOutOfOrderWrites bool
}
// NewPriorityWriteScheduler constructs a WriteScheduler that schedules
// frames by following HTTP/2 priorities as described in RFC 7540 Section 5.3.
// If cfg is nil, default options are used.
func http2NewPriorityWriteScheduler(cfg *http2PriorityWriteSchedulerConfig) http2WriteScheduler {
if cfg == nil {
// For justification of these defaults, see:
// https://docs.google.com/document/d/1oLhNg1skaWD4_DtaoCxdSRN5erEXrH-KnLrMwEpOtFY
cfg = &http2PriorityWriteSchedulerConfig{
MaxClosedNodesInTree: 10,
MaxIdleNodesInTree: 10,
ThrottleOutOfOrderWrites: false,
}
}
ws := &http2priorityWriteScheduler{
nodes: make(map[uint32]*http2priorityNode),
maxClosedNodesInTree: cfg.MaxClosedNodesInTree,
maxIdleNodesInTree: cfg.MaxIdleNodesInTree,
enableWriteThrottle: cfg.ThrottleOutOfOrderWrites,
}
ws.nodes[0] = &ws.root
if cfg.ThrottleOutOfOrderWrites {
ws.writeThrottleLimit = 1024
} else {
ws.writeThrottleLimit = math.MaxInt32
}
return ws
}
type http2priorityNodeState int
const (
http2priorityNodeOpen http2priorityNodeState = iota
http2priorityNodeClosed
http2priorityNodeIdle
)
// priorityNode is a node in an HTTP/2 priority tree.
// Each node is associated with a single stream ID.
// See RFC 7540, Section 5.3.
type http2priorityNode struct {
q http2writeQueue // queue of pending frames to write
id uint32 // id of the stream, or 0 for the root of the tree
weight uint8 // the actual weight is weight+1, so the value is in [1,256]
state http2priorityNodeState // open | closed | idle
bytes int64 // number of bytes written by this node, or 0 if closed
subtreeBytes int64 // sum(node.bytes) of all nodes in this subtree
// These links form the priority tree.
parent *http2priorityNode
kids *http2priorityNode // start of the kids list
prev, next *http2priorityNode // doubly-linked list of siblings
}
func (n *http2priorityNode) setParent(parent *http2priorityNode) {
if n == parent {
panic("setParent to self")
}
if n.parent == parent {
return
}
// Unlink from current parent.
if parent := n.parent; parent != nil {
if n.prev == nil {
parent.kids = n.next
} else {
n.prev.next = n.next
}
if n.next != nil {
n.next.prev = n.prev
}
}
// Link to new parent.
// If parent=nil, remove n from the tree.
// Always insert at the head of parent.kids (this is assumed by walkReadyInOrder).
n.parent = parent
if parent == nil {
n.next = nil
n.prev = nil
} else {
n.next = parent.kids
n.prev = nil
if n.next != nil {
n.next.prev = n
}
parent.kids = n
}
}
func (n *http2priorityNode) addBytes(b int64) {
n.bytes += b
for ; n != nil; n = n.parent {
n.subtreeBytes += b
}
}
// walkReadyInOrder iterates over the tree in priority order, calling f for each node
// with a non-empty write queue. When f returns true, this funcion returns true and the
// walk halts. tmp is used as scratch space for sorting.
//
// f(n, openParent) takes two arguments: the node to visit, n, and a bool that is true
// if any ancestor p of n is still open (ignoring the root node).
func (n *http2priorityNode) walkReadyInOrder(openParent bool, tmp *[]*http2priorityNode, f func(*http2priorityNode, bool) bool) bool {
if !n.q.empty() && f(n, openParent) {
return true
}
if n.kids == nil {
return false
}
// Don't consider the root "open" when updating openParent since
// we can't send data frames on the root stream (only control frames).
if n.id != 0 {
openParent = openParent || (n.state == http2priorityNodeOpen)
}
// Common case: only one kid or all kids have the same weight.
// Some clients don't use weights; other clients (like web browsers)
// use mostly-linear priority trees.
w := n.kids.weight
needSort := false
for k := n.kids.next; k != nil; k = k.next {
if k.weight != w {
needSort = true
break
}
}
if !needSort {
for k := n.kids; k != nil; k = k.next {
if k.walkReadyInOrder(openParent, tmp, f) {
return true
}
}
return false
}
// Uncommon case: sort the child nodes. We remove the kids from the parent,
// then re-insert after sorting so we can reuse tmp for future sort calls.
*tmp = (*tmp)[:0]
for n.kids != nil {
*tmp = append(*tmp, n.kids)
n.kids.setParent(nil)
}
sort.Sort(http2sortPriorityNodeSiblings(*tmp))
for i := len(*tmp) - 1; i >= 0; i-- {
(*tmp)[i].setParent(n) // setParent inserts at the head of n.kids
}
for k := n.kids; k != nil; k = k.next {
if k.walkReadyInOrder(openParent, tmp, f) {
return true
}
}
return false
}
type http2sortPriorityNodeSiblings []*http2priorityNode
func (z http2sortPriorityNodeSiblings) Len() int { return len(z) }
func (z http2sortPriorityNodeSiblings) Swap(i, k int) { z[i], z[k] = z[k], z[i] }
func (z http2sortPriorityNodeSiblings) Less(i, k int) bool {
// Prefer the subtree that has sent fewer bytes relative to its weight.
// See sections 5.3.2 and 5.3.4.
wi, bi := float64(z[i].weight+1), float64(z[i].subtreeBytes)
wk, bk := float64(z[k].weight+1), float64(z[k].subtreeBytes)
if bi == 0 && bk == 0 {
return wi >= wk
}
if bk == 0 {
return false
}
return bi/bk <= wi/wk
}
type http2priorityWriteScheduler struct {
// root is the root of the priority tree, where root.id = 0.
// The root queues control frames that are not associated with any stream.
root http2priorityNode
// nodes maps stream ids to priority tree nodes.
nodes map[uint32]*http2priorityNode
// maxID is the maximum stream id in nodes.
maxID uint32
// lists of nodes that have been closed or are idle, but are kept in
// the tree for improved prioritization. When the lengths exceed either
// maxClosedNodesInTree or maxIdleNodesInTree, old nodes are discarded.
closedNodes, idleNodes []*http2priorityNode
// From the config.
maxClosedNodesInTree int
maxIdleNodesInTree int
writeThrottleLimit int32
enableWriteThrottle bool
// tmp is scratch space for priorityNode.walkReadyInOrder to reduce allocations.
tmp []*http2priorityNode
// pool of empty queues for reuse.
queuePool http2writeQueuePool
}
func (ws *http2priorityWriteScheduler) OpenStream(streamID uint32, options http2OpenStreamOptions) {
// The stream may be currently idle but cannot be opened or closed.
if curr := ws.nodes[streamID]; curr != nil {
if curr.state != http2priorityNodeIdle {
panic(fmt.Sprintf("stream %d already opened", streamID))
}
curr.state = http2priorityNodeOpen
return
}
// RFC 7540, Section 5.3.5:
// "All streams are initially assigned a non-exclusive dependency on stream 0x0.
// Pushed streams initially depend on their associated stream. In both cases,
// streams are assigned a default weight of 16."
parent := ws.nodes[options.PusherID]
if parent == nil {
parent = &ws.root
}
n := &http2priorityNode{
q: *ws.queuePool.get(),
id: streamID,
weight: http2priorityDefaultWeight,
state: http2priorityNodeOpen,
}
n.setParent(parent)
ws.nodes[streamID] = n
if streamID > ws.maxID {
ws.maxID = streamID
}
}
func (ws *http2priorityWriteScheduler) CloseStream(streamID uint32) {
if streamID == 0 {
panic("violation of WriteScheduler interface: cannot close stream 0")
}
if ws.nodes[streamID] == nil {
panic(fmt.Sprintf("violation of WriteScheduler interface: unknown stream %d", streamID))
}
if ws.nodes[streamID].state != http2priorityNodeOpen {
panic(fmt.Sprintf("violation of WriteScheduler interface: stream %d already closed", streamID))
}
n := ws.nodes[streamID]
n.state = http2priorityNodeClosed
n.addBytes(-n.bytes)
q := n.q
ws.queuePool.put(&q)
n.q.s = nil
if ws.maxClosedNodesInTree > 0 {
ws.addClosedOrIdleNode(&ws.closedNodes, ws.maxClosedNodesInTree, n)
} else {
ws.removeNode(n)
}
}
func (ws *http2priorityWriteScheduler) AdjustStream(streamID uint32, priority http2PriorityParam) {
if streamID == 0 {
panic("adjustPriority on root")
}
// If streamID does not exist, there are two cases:
// - A closed stream that has been removed (this will have ID <= maxID)
// - An idle stream that is being used for "grouping" (this will have ID > maxID)
n := ws.nodes[streamID]
if n == nil {
if streamID <= ws.maxID || ws.maxIdleNodesInTree == 0 {
return
}
ws.maxID = streamID
n = &http2priorityNode{
q: *ws.queuePool.get(),
id: streamID,
weight: http2priorityDefaultWeight,
state: http2priorityNodeIdle,
}
n.setParent(&ws.root)
ws.nodes[streamID] = n
ws.addClosedOrIdleNode(&ws.idleNodes, ws.maxIdleNodesInTree, n)
}
// Section 5.3.1: A dependency on a stream that is not currently in the tree
// results in that stream being given a default priority (Section 5.3.5).
parent := ws.nodes[priority.StreamDep]
if parent == nil {
n.setParent(&ws.root)
n.weight = http2priorityDefaultWeight
return
}
// Ignore if the client tries to make a node its own parent.
if n == parent {
return
}
// Section 5.3.3:
// "If a stream is made dependent on one of its own dependencies, the
// formerly dependent stream is first moved to be dependent on the
// reprioritized stream's previous parent. The moved dependency retains
// its weight."
//
// That is: if parent depends on n, move parent to depend on n.parent.
for x := parent.parent; x != nil; x = x.parent {
if x == n {
parent.setParent(n.parent)
break
}
}
// Section 5.3.3: The exclusive flag causes the stream to become the sole
// dependency of its parent stream, causing other dependencies to become
// dependent on the exclusive stream.
if priority.Exclusive {
k := parent.kids
for k != nil {
next := k.next
if k != n {
k.setParent(n)
}
k = next
}
}
n.setParent(parent)
n.weight = priority.Weight
}
func (ws *http2priorityWriteScheduler) Push(wr http2FrameWriteRequest) {
var n *http2priorityNode
if id := wr.StreamID(); id == 0 {
n = &ws.root
} else {
n = ws.nodes[id]
if n == nil {
// id is an idle or closed stream. wr should not be a HEADERS or
// DATA frame. However, wr can be a RST_STREAM. In this case, we
// push wr onto the root, rather than creating a new priorityNode,
// since RST_STREAM is tiny and the stream's priority is unknown
// anyway. See issue #17919.
if wr.DataSize() > 0 {
panic("add DATA on non-open stream")
}
n = &ws.root
}
}
n.q.push(wr)
}
func (ws *http2priorityWriteScheduler) Pop() (wr http2FrameWriteRequest, ok bool) {
ws.root.walkReadyInOrder(false, &ws.tmp, func(n *http2priorityNode, openParent bool) bool {
limit := int32(math.MaxInt32)
if openParent {
limit = ws.writeThrottleLimit
}
wr, ok = n.q.consume(limit)
if !ok {
return false
}
n.addBytes(int64(wr.DataSize()))
// If B depends on A and B continuously has data available but A
// does not, gradually increase the throttling limit to allow B to
// steal more and more bandwidth from A.
if openParent {
ws.writeThrottleLimit += 1024
if ws.writeThrottleLimit < 0 {
ws.writeThrottleLimit = math.MaxInt32
}
} else if ws.enableWriteThrottle {
ws.writeThrottleLimit = 1024
}
return true
})
return wr, ok
}
func (ws *http2priorityWriteScheduler) addClosedOrIdleNode(list *[]*http2priorityNode, maxSize int, n *http2priorityNode) {
if maxSize == 0 {
return
}
if len(*list) == maxSize {
// Remove the oldest node, then shift left.
ws.removeNode((*list)[0])
x := (*list)[1:]
copy(*list, x)
*list = (*list)[:len(x)]
}
*list = append(*list, n)
}
func (ws *http2priorityWriteScheduler) removeNode(n *http2priorityNode) {
for k := n.kids; k != nil; k = k.next {
k.setParent(n.parent)
}
n.setParent(nil)
delete(ws.nodes, n.id)
}
// NewRandomWriteScheduler constructs a WriteScheduler that ignores HTTP/2
// priorities. Control frames like SETTINGS and PING are written before DATA
// frames, but if no control frames are queued and multiple streams have queued
// HEADERS or DATA frames, Pop selects a ready stream arbitrarily.
func http2NewRandomWriteScheduler() http2WriteScheduler {
return &http2randomWriteScheduler{sq: make(map[uint32]*http2writeQueue)}
}
type http2randomWriteScheduler struct {
// zero are frames not associated with a specific stream.
zero http2writeQueue
// sq contains the stream-specific queues, keyed by stream ID.
// When a stream is idle or closed, it's deleted from the map.
sq map[uint32]*http2writeQueue
// pool of empty queues for reuse.
queuePool http2writeQueuePool
}
func (ws *http2randomWriteScheduler) OpenStream(streamID uint32, options http2OpenStreamOptions) {
// no-op: idle streams are not tracked
}
func (ws *http2randomWriteScheduler) CloseStream(streamID uint32) {
q, ok := ws.sq[streamID]
if !ok {
return
}
delete(ws.sq, streamID)
ws.queuePool.put(q)
}
func (ws *http2randomWriteScheduler) AdjustStream(streamID uint32, priority http2PriorityParam) {
// no-op: priorities are ignored
}
func (ws *http2randomWriteScheduler) Push(wr http2FrameWriteRequest) {
id := wr.StreamID()
if id == 0 {
ws.zero.push(wr)
return
}
q, ok := ws.sq[id]
if !ok {
q = ws.queuePool.get()
ws.sq[id] = q
}
q.push(wr)
}
func (ws *http2randomWriteScheduler) Pop() (http2FrameWriteRequest, bool) {
// Control frames first.
if !ws.zero.empty() {
return ws.zero.shift(), true
}
// Iterate over all non-idle streams until finding one that can be consumed.
for _, q := range ws.sq {
if wr, ok := q.consume(math.MaxInt32); ok {
return wr, true
}
}
return http2FrameWriteRequest{}, false
}