#!/usr/bin/python
# @lint-avoid-python-3-compatibility-imports
#
# tcptop Summarize TCP send/recv throughput by host.
# For Linux, uses BCC, eBPF. Embedded C.
#
# USAGE: tcptop [-h] [-C] [-S] [-p PID] [interval [count]]
#
# This uses dynamic tracing of kernel functions, and will need to be updated
# to match kernel changes.
#
# WARNING: This traces all send/receives at the TCP level, and while it
# summarizes data in-kernel to reduce overhead, there may still be some
# overhead at high TCP send/receive rates (eg, ~13% of one CPU at 100k TCP
# events/sec. This is not the same as packet rate: funccount can be used to
# count the kprobes below to find out the TCP rate). Test in a lab environment
# first. If your send/receive rate is low (eg, <1k/sec) then the overhead is
# expected to be negligible.
#
# ToDo: Fit output to screen size (top X only) in default (not -C) mode.
#
# Copyright 2016 Netflix, Inc.
# Licensed under the Apache License, Version 2.0 (the "License")
#
# 02-Sep-2016 Brendan Gregg Created this.
from __future__ import print_function
from bcc import BPF
import argparse
from socket import inet_ntop, AF_INET, AF_INET6
from struct import pack
from time import sleep, strftime
from subprocess import call
import ctypes as ct
from collections import namedtuple, defaultdict
# arguments
def range_check(string):
value = int(string)
if value < 1:
msg = "value must be stricly positive, got %d" % (value,)
raise argparse.ArgumentTypeError(msg)
return value
examples = """examples:
./tcptop # trace TCP send/recv by host
./tcptop -C # don't clear the screen
./tcptop -p 181 # only trace PID 181
"""
parser = argparse.ArgumentParser(
description="Summarize TCP send/recv throughput by host",
formatter_class=argparse.RawDescriptionHelpFormatter,
epilog=examples)
parser.add_argument("-C", "--noclear", action="store_true",
help="don't clear the screen")
parser.add_argument("-S", "--nosummary", action="store_true",
help="skip system summary line")
parser.add_argument("-p", "--pid",
help="trace this PID only")
parser.add_argument("interval", nargs="?", default=1, type=range_check,
help="output interval, in seconds (default 1)")
parser.add_argument("count", nargs="?", default=-1, type=range_check,
help="number of outputs")
parser.add_argument("--ebpf", action="store_true",
help=argparse.SUPPRESS)
args = parser.parse_args()
debug = 0
# linux stats
loadavg = "/proc/loadavg"
# define BPF program
bpf_text = """
#include <uapi/linux/ptrace.h>
#include <net/sock.h>
#include <bcc/proto.h>
struct ipv4_key_t {
u32 pid;
u32 saddr;
u32 daddr;
u16 lport;
u16 dport;
};
BPF_HASH(ipv4_send_bytes, struct ipv4_key_t);
BPF_HASH(ipv4_recv_bytes, struct ipv4_key_t);
struct ipv6_key_t {
u32 pid;
unsigned __int128 saddr;
unsigned __int128 daddr;
u16 lport;
u16 dport;
};
BPF_HASH(ipv6_send_bytes, struct ipv6_key_t);
BPF_HASH(ipv6_recv_bytes, struct ipv6_key_t);
int kprobe__tcp_sendmsg(struct pt_regs *ctx, struct sock *sk,
struct msghdr *msg, size_t size)
{
u32 pid = bpf_get_current_pid_tgid();
FILTER
u16 dport = 0, family = sk->__sk_common.skc_family;
if (family == AF_INET) {
struct ipv4_key_t ipv4_key = {.pid = pid};
ipv4_key.saddr = sk->__sk_common.skc_rcv_saddr;
ipv4_key.daddr = sk->__sk_common.skc_daddr;
ipv4_key.lport = sk->__sk_common.skc_num;
dport = sk->__sk_common.skc_dport;
ipv4_key.dport = ntohs(dport);
ipv4_send_bytes.increment(ipv4_key, size);
} else if (family == AF_INET6) {
struct ipv6_key_t ipv6_key = {.pid = pid};
__builtin_memcpy(&ipv6_key.saddr,
sk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32, sizeof(ipv6_key.saddr));
__builtin_memcpy(&ipv6_key.daddr,
sk->__sk_common.skc_v6_daddr.in6_u.u6_addr32, sizeof(ipv6_key.daddr));
ipv6_key.lport = sk->__sk_common.skc_num;
dport = sk->__sk_common.skc_dport;
ipv6_key.dport = ntohs(dport);
ipv6_send_bytes.increment(ipv6_key, size);
}
// else drop
return 0;
}
/*
* tcp_recvmsg() would be obvious to trace, but is less suitable because:
* - we'd need to trace both entry and return, to have both sock and size
* - misses tcp_read_sock() traffic
* we'd much prefer tracepoints once they are available.
*/
int kprobe__tcp_cleanup_rbuf(struct pt_regs *ctx, struct sock *sk, int copied)
{
u32 pid = bpf_get_current_pid_tgid();
FILTER
u16 dport = 0, family = sk->__sk_common.skc_family;
u64 *val, zero = 0;
if (copied <= 0)
return 0;
if (family == AF_INET) {
struct ipv4_key_t ipv4_key = {.pid = pid};
ipv4_key.saddr = sk->__sk_common.skc_rcv_saddr;
ipv4_key.daddr = sk->__sk_common.skc_daddr;
ipv4_key.lport = sk->__sk_common.skc_num;
dport = sk->__sk_common.skc_dport;
ipv4_key.dport = ntohs(dport);
ipv4_recv_bytes.increment(ipv4_key, copied);
} else if (family == AF_INET6) {
struct ipv6_key_t ipv6_key = {.pid = pid};
__builtin_memcpy(&ipv6_key.saddr,
sk->__sk_common.skc_v6_rcv_saddr.in6_u.u6_addr32, sizeof(ipv6_key.saddr));
__builtin_memcpy(&ipv6_key.daddr,
sk->__sk_common.skc_v6_daddr.in6_u.u6_addr32, sizeof(ipv6_key.daddr));
ipv6_key.lport = sk->__sk_common.skc_num;
dport = sk->__sk_common.skc_dport;
ipv6_key.dport = ntohs(dport);
ipv6_recv_bytes.increment(ipv6_key, copied);
}
// else drop
return 0;
}
"""
# code substitutions
if args.pid:
bpf_text = bpf_text.replace('FILTER',
'if (pid != %s) { return 0; }' % args.pid)
else:
bpf_text = bpf_text.replace('FILTER', '')
if debug or args.ebpf:
print(bpf_text)
if args.ebpf:
exit()
TCPSessionKey = namedtuple('TCPSession', ['pid', 'laddr', 'lport', 'daddr', 'dport'])
def pid_to_comm(pid):
try:
comm = open("/proc/%d/comm" % pid, "r").read().rstrip()
return comm
except IOError:
return str(pid)
def get_ipv4_session_key(k):
return TCPSessionKey(pid=k.pid,
laddr=inet_ntop(AF_INET, pack("I", k.saddr)),
lport=k.lport,
daddr=inet_ntop(AF_INET, pack("I", k.daddr)),
dport=k.dport)
def get_ipv6_session_key(k):
return TCPSessionKey(pid=k.pid,
laddr=inet_ntop(AF_INET6, k.saddr),
lport=k.lport,
daddr=inet_ntop(AF_INET6, k.daddr),
dport=k.dport)
# initialize BPF
b = BPF(text=bpf_text)
ipv4_send_bytes = b["ipv4_send_bytes"]
ipv4_recv_bytes = b["ipv4_recv_bytes"]
ipv6_send_bytes = b["ipv6_send_bytes"]
ipv6_recv_bytes = b["ipv6_recv_bytes"]
print('Tracing... Output every %s secs. Hit Ctrl-C to end' % args.interval)
# output
i = 0
exiting = False
while i != args.count and not exiting:
try:
sleep(args.interval)
except KeyboardInterrupt:
exiting = True
# header
if args.noclear:
print()
else:
call("clear")
if not args.nosummary:
with open(loadavg) as stats:
print("%-8s loadavg: %s" % (strftime("%H:%M:%S"), stats.read()))
# IPv4: build dict of all seen keys
ipv4_throughput = defaultdict(lambda: [0, 0])
for k, v in ipv4_send_bytes.items():
key = get_ipv4_session_key(k)
ipv4_throughput[key][0] = v.value
ipv4_send_bytes.clear()
for k, v in ipv4_recv_bytes.items():
key = get_ipv4_session_key(k)
ipv4_throughput[key][1] = v.value
ipv4_recv_bytes.clear()
if ipv4_throughput:
print("%-6s %-12s %-21s %-21s %6s %6s" % ("PID", "COMM",
"LADDR", "RADDR", "RX_KB", "TX_KB"))
# output
for k, (send_bytes, recv_bytes) in sorted(ipv4_throughput.items(),
key=lambda kv: sum(kv[1]),
reverse=True):
print("%-6d %-12.12s %-21s %-21s %6d %6d" % (k.pid,
pid_to_comm(k.pid),
k.laddr + ":" + str(k.lport),
k.daddr + ":" + str(k.dport),
int(recv_bytes / 1024), int(send_bytes / 1024)))
# IPv6: build dict of all seen keys
ipv6_throughput = defaultdict(lambda: [0, 0])
for k, v in ipv6_send_bytes.items():
key = get_ipv6_session_key(k)
ipv6_throughput[key][0] = v.value
ipv6_send_bytes.clear()
for k, v in ipv6_recv_bytes.items():
key = get_ipv6_session_key(k)
ipv6_throughput[key][1] = v.value
ipv6_recv_bytes.clear()
if ipv6_throughput:
# more than 80 chars, sadly.
print("\n%-6s %-12s %-32s %-32s %6s %6s" % ("PID", "COMM",
"LADDR6", "RADDR6", "RX_KB", "TX_KB"))
# output
for k, (send_bytes, recv_bytes) in sorted(ipv6_throughput.items(),
key=lambda kv: sum(kv[1]),
reverse=True):
print("%-6d %-12.12s %-32s %-32s %6d %6d" % (k.pid,
pid_to_comm(k.pid),
k.laddr + ":" + str(k.lport),
k.daddr + ":" + str(k.dport),
int(recv_bytes / 1024), int(send_bytes / 1024)))
i += 1