/* $NetBSD: gethnamaddr.c,v 1.91 2014/06/19 15:08:18 christos Exp $ */
/*
* ++Copyright++ 1985, 1988, 1993
* -
* Copyright (c) 1985, 1988, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* -
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies, and that
* the name of Digital Equipment Corporation not be used in advertising or
* publicity pertaining to distribution of the document or software without
* specific, written prior permission.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
* SOFTWARE.
* -
* --Copyright--
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include "NetdClientDispatch.h"
#include "resolv_netid.h"
#include "resolv_private.h"
#include "resolv_cache.h"
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdio.h>
#include <strings.h>
#include <syslog.h>
#include <unistd.h>
#define ALIGNBYTES (sizeof(uintptr_t) - 1)
#define ALIGN(p) (((uintptr_t)(p) + ALIGNBYTES) &~ ALIGNBYTES)
#ifndef LOG_AUTH
# define LOG_AUTH 0
#endif
#define MULTI_PTRS_ARE_ALIASES 1 /* XXX - experimental */
#include "nsswitch.h"
#include <stdlib.h>
#include <string.h>
#include "hostent.h"
#define maybe_ok(res, nm, ok) (((res)->options & RES_NOCHECKNAME) != 0U || \
(ok)(nm) != 0)
#define maybe_hnok(res, hn) maybe_ok((res), (hn), res_hnok)
#define maybe_dnok(res, dn) maybe_ok((res), (dn), res_dnok)
#define addalias(d, s, arr, siz) do { \
if (d >= &arr[siz]) { \
char **xptr = realloc(arr, (siz + 10) * sizeof(*arr)); \
if (xptr == NULL) \
goto nospc; \
d = xptr + (d - arr); \
arr = xptr; \
siz += 10; \
} \
*d++ = s; \
} while (/*CONSTCOND*/0)
#define setup(arr, siz) do { \
arr = malloc((siz = 10) * sizeof(*arr)); \
if (arr == NULL) \
goto nospc; \
} while (/*CONSTCOND*/0)
// This should be synchronized to ResponseCode.h
static const int DnsProxyQueryResult = 222;
static const char AskedForGot[] =
"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
#define MAXPACKET (64*1024)
typedef union {
HEADER hdr;
u_char buf[MAXPACKET];
} querybuf;
typedef union {
int32_t al;
char ac;
} align;
#ifdef DEBUG
static void debugprintf(const char *, res_state, ...)
__attribute__((__format__(__printf__, 1, 3)));
#endif
static struct hostent *getanswer(const querybuf *, int, const char *, int,
res_state, struct hostent *, char *, size_t, int *);
static void map_v4v6_address(const char *, char *);
static void map_v4v6_hostent(struct hostent *, char **, char *);
static void addrsort(char **, int, res_state);
void ht_sethostent(int);
void ht_endhostent(void);
struct hostent *ht_gethostbyname(char *);
struct hostent *ht_gethostbyaddr(const char *, int, int);
void dns_service(void);
#undef dn_skipname
int dn_skipname(const u_char *, const u_char *);
static int _dns_gethtbyaddr(void *, void *, va_list);
static int _dns_gethtbyname(void *, void *, va_list);
static struct hostent *gethostbyname_internal(const char *, int, res_state,
struct hostent *, char *, size_t, int *, unsigned, unsigned);
static struct hostent* android_gethostbyaddrfornet_proxy_internal(const void*, socklen_t,
int, struct hostent *, char *, size_t, int *, unsigned, unsigned);
static const ns_src default_dns_files[] = {
{ NSSRC_FILES, NS_SUCCESS },
{ NSSRC_DNS, NS_SUCCESS },
{ 0, 0 }
};
#ifdef DEBUG
static void
debugprintf(const char *msg, res_state res, ...)
{
_DIAGASSERT(msg != NULL);
if (res->options & RES_DEBUG) {
int save = errno;
va_list ap;
va_start (ap, res);
vprintf(msg, ap);
va_end (ap);
errno = save;
}
}
#else
# define debugprintf(msg, res, num) /*nada*/
#endif
#define BOUNDED_INCR(x) \
do { \
BOUNDS_CHECK(cp, x); \
cp += (x); \
} while (/*CONSTCOND*/0)
#define BOUNDS_CHECK(ptr, count) \
do { \
if (eom - (ptr) < (count)) \
goto no_recovery; \
} while (/*CONSTCOND*/0)
static struct hostent *
getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
res_state res, struct hostent *hent, char *buf, size_t buflen, int *he)
{
const HEADER *hp;
const u_char *cp;
int n;
size_t qlen;
const u_char *eom, *erdata;
char *bp, **ap, **hap, *ep;
int type, class, ancount, qdcount;
int haveanswer, had_error;
int toobig = 0;
char tbuf[MAXDNAME];
char **aliases;
size_t maxaliases;
char *addr_ptrs[MAXADDRS];
const char *tname;
int (*name_ok)(const char *);
_DIAGASSERT(answer != NULL);
_DIAGASSERT(qname != NULL);
tname = qname;
hent->h_name = NULL;
eom = answer->buf + anslen;
switch (qtype) {
case T_A:
case T_AAAA:
name_ok = res_hnok;
break;
case T_PTR:
name_ok = res_dnok;
break;
default:
*he = NO_RECOVERY;
return NULL; /* XXX should be abort(); */
}
setup(aliases, maxaliases);
/*
* find first satisfactory answer
*/
hp = &answer->hdr;
ancount = ntohs(hp->ancount);
qdcount = ntohs(hp->qdcount);
bp = buf;
ep = buf + buflen;
cp = answer->buf;
BOUNDED_INCR(HFIXEDSZ);
if (qdcount != 1)
goto no_recovery;
n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
if ((n < 0) || !maybe_ok(res, bp, name_ok))
goto no_recovery;
BOUNDED_INCR(n + QFIXEDSZ);
if (qtype == T_A || qtype == T_AAAA) {
/* res_send() has already verified that the query name is the
* same as the one we sent; this just gets the expanded name
* (i.e., with the succeeding search-domain tacked on).
*/
n = (int)strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN)
goto no_recovery;
hent->h_name = bp;
bp += n;
/* The qname can be abbreviated, but h_name is now absolute. */
qname = hent->h_name;
}
hent->h_aliases = ap = aliases;
hent->h_addr_list = hap = addr_ptrs;
*ap = NULL;
*hap = NULL;
haveanswer = 0;
had_error = 0;
while (ancount-- > 0 && cp < eom && !had_error) {
n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
if ((n < 0) || !maybe_ok(res, bp, name_ok)) {
had_error++;
continue;
}
cp += n; /* name */
BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
type = _getshort(cp);
cp += INT16SZ; /* type */
class = _getshort(cp);
cp += INT16SZ + INT32SZ; /* class, TTL */
n = _getshort(cp);
cp += INT16SZ; /* len */
BOUNDS_CHECK(cp, n);
erdata = cp + n;
if (class != C_IN) {
/* XXX - debug? syslog? */
cp += n;
continue; /* XXX - had_error++ ? */
}
if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
n = dn_expand(answer->buf, eom, cp, tbuf,
(int)sizeof tbuf);
if ((n < 0) || !maybe_ok(res, tbuf, name_ok)) {
had_error++;
continue;
}
cp += n;
if (cp != erdata)
goto no_recovery;
/* Store alias. */
addalias(ap, bp, aliases, maxaliases);
n = (int)strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
had_error++;
continue;
}
bp += n;
/* Get canonical name. */
n = (int)strlen(tbuf) + 1; /* for the \0 */
if (n > ep - bp || n >= MAXHOSTNAMELEN) {
had_error++;
continue;
}
strlcpy(bp, tbuf, (size_t)(ep - bp));
hent->h_name = bp;
bp += n;
continue;
}
if (qtype == T_PTR && type == T_CNAME) {
n = dn_expand(answer->buf, eom, cp, tbuf,
(int)sizeof tbuf);
if (n < 0 || !maybe_dnok(res, tbuf)) {
had_error++;
continue;
}
cp += n;
if (cp != erdata)
goto no_recovery;
/* Get canonical name. */
n = (int)strlen(tbuf) + 1; /* for the \0 */
if (n > ep - bp || n >= MAXHOSTNAMELEN) {
had_error++;
continue;
}
strlcpy(bp, tbuf, (size_t)(ep - bp));
tname = bp;
bp += n;
continue;
}
if (type != qtype) {
if (type != T_KEY && type != T_SIG)
syslog(LOG_NOTICE|LOG_AUTH,
"gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
qname, p_class(C_IN), p_type(qtype),
p_type(type));
cp += n;
continue; /* XXX - had_error++ ? */
}
switch (type) {
case T_PTR:
if (strcasecmp(tname, bp) != 0) {
syslog(LOG_NOTICE|LOG_AUTH,
AskedForGot, qname, bp);
cp += n;
continue; /* XXX - had_error++ ? */
}
n = dn_expand(answer->buf, eom, cp, bp, (int)(ep - bp));
if ((n < 0) || !maybe_hnok(res, bp)) {
had_error++;
break;
}
#if MULTI_PTRS_ARE_ALIASES
cp += n;
if (cp != erdata)
goto no_recovery;
if (!haveanswer)
hent->h_name = bp;
else
addalias(ap, bp, aliases, maxaliases);
if (n != -1) {
n = (int)strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
had_error++;
break;
}
bp += n;
}
break;
#else
hent->h_name = bp;
if (res->options & RES_USE_INET6) {
n = strlen(bp) + 1; /* for the \0 */
if (n >= MAXHOSTNAMELEN) {
had_error++;
break;
}
bp += n;
map_v4v6_hostent(hent, &bp, ep);
}
goto success;
#endif
case T_A:
case T_AAAA:
if (strcasecmp(hent->h_name, bp) != 0) {
syslog(LOG_NOTICE|LOG_AUTH,
AskedForGot, hent->h_name, bp);
cp += n;
continue; /* XXX - had_error++ ? */
}
if (n != hent->h_length) {
cp += n;
continue;
}
if (type == T_AAAA) {
struct in6_addr in6;
memcpy(&in6, cp, NS_IN6ADDRSZ);
if (IN6_IS_ADDR_V4MAPPED(&in6)) {
cp += n;
continue;
}
}
if (!haveanswer) {
int nn;
hent->h_name = bp;
nn = (int)strlen(bp) + 1; /* for the \0 */
bp += nn;
}
bp += sizeof(align) -
(size_t)((u_long)bp % sizeof(align));
if (bp + n >= ep) {
debugprintf("size (%d) too big\n", res, n);
had_error++;
continue;
}
if (hap >= &addr_ptrs[MAXADDRS - 1]) {
if (!toobig++) {
debugprintf("Too many addresses (%d)\n",
res, MAXADDRS);
}
cp += n;
continue;
}
(void)memcpy(*hap++ = bp, cp, (size_t)n);
bp += n;
cp += n;
if (cp != erdata)
goto no_recovery;
break;
default:
abort();
}
if (!had_error)
haveanswer++;
}
if (haveanswer) {
*ap = NULL;
*hap = NULL;
/*
* Note: we sort even if host can take only one address
* in its return structures - should give it the "best"
* address in that case, not some random one
*/
if (res->nsort && haveanswer > 1 && qtype == T_A)
addrsort(addr_ptrs, haveanswer, res);
if (!hent->h_name) {
n = (int)strlen(qname) + 1; /* for the \0 */
if (n > ep - bp || n >= MAXHOSTNAMELEN)
goto no_recovery;
strlcpy(bp, qname, (size_t)(ep - bp));
hent->h_name = bp;
bp += n;
}
if (res->options & RES_USE_INET6)
map_v4v6_hostent(hent, &bp, ep);
goto success;
}
no_recovery:
free(aliases);
*he = NO_RECOVERY;
return NULL;
success:
bp = (char *)ALIGN(bp);
n = (int)(ap - aliases);
qlen = (n + 1) * sizeof(*hent->h_aliases);
if ((size_t)(ep - bp) < qlen)
goto nospc;
hent->h_aliases = (void *)bp;
memcpy(bp, aliases, qlen);
free(aliases);
aliases = NULL;
bp += qlen;
n = (int)(hap - addr_ptrs);
qlen = (n + 1) * sizeof(*hent->h_addr_list);
if ((size_t)(ep - bp) < qlen)
goto nospc;
hent->h_addr_list = (void *)bp;
memcpy(bp, addr_ptrs, qlen);
*he = NETDB_SUCCESS;
return hent;
nospc:
free(aliases);
errno = ENOSPC;
*he = NETDB_INTERNAL;
return NULL;
}
/* The prototype of gethostbyname_r is from glibc, not that in netbsd. */
int
gethostbyname_r(const char *name, struct hostent *hp, char *buf, size_t buflen,
struct hostent **result, int *errorp)
{
res_state res = __res_get_state();
if (res == NULL) {
*result = NULL;
*errorp = NETDB_INTERNAL;
return -1;
}
_DIAGASSERT(name != NULL);
if (res->options & RES_USE_INET6) {
*result = gethostbyname_internal(name, AF_INET6, res, hp, buf, buflen, errorp, NETID_UNSET,
MARK_UNSET);
if (*result) {
__res_put_state(res);
return 0;
}
}
*result = gethostbyname_internal(name, AF_INET, res, hp, buf, buflen, errorp, NETID_UNSET,
MARK_UNSET);
__res_put_state(res);
if (!*result && errno == ENOSPC) {
errno = ERANGE;
return ERANGE; /* Return error as in linux manual page. */
}
return (*result) ? 0 : -1;
}
/* The prototype of gethostbyname2_r is from glibc, not that in netbsd. */
int
gethostbyname2_r(const char *name, int af, struct hostent *hp, char *buf,
size_t buflen, struct hostent **result, int *errorp)
{
res_state res = __res_get_state();
if (res == NULL) {
*result = NULL;
*errorp = NETDB_INTERNAL;
return -1;
}
*result = gethostbyname_internal(name, af, res, hp, buf, buflen, errorp, NETID_UNSET,
MARK_UNSET);
__res_put_state(res);
if (!*result && errno == ENOSPC) {
errno = ERANGE;
return ERANGE;
}
return (*result) ? 0 : -1;
}
__LIBC_HIDDEN__ FILE* android_open_proxy() {
const char* cache_mode = getenv("ANDROID_DNS_MODE");
bool use_proxy = (cache_mode == NULL || strcmp(cache_mode, "local") != 0);
if (!use_proxy) {
return NULL;
}
int s = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
if (s == -1) {
return NULL;
}
const int one = 1;
setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
struct sockaddr_un proxy_addr;
memset(&proxy_addr, 0, sizeof(proxy_addr));
proxy_addr.sun_family = AF_UNIX;
strlcpy(proxy_addr.sun_path, "/dev/socket/dnsproxyd", sizeof(proxy_addr.sun_path));
if (TEMP_FAILURE_RETRY(connect(s, (const struct sockaddr*) &proxy_addr, sizeof(proxy_addr))) != 0) {
close(s);
return NULL;
}
return fdopen(s, "r+");
}
static struct hostent *
android_read_hostent(FILE* proxy, struct hostent* hp, char* hbuf, size_t hbuflen, int *he)
{
uint32_t size;
char buf[4];
if (fread(buf, 1, sizeof(buf), proxy) != sizeof(buf)) return NULL;
// This is reading serialized data from system/netd/server/DnsProxyListener.cpp
// and changes here need to be matched there.
int result_code = strtol(buf, NULL, 10);
if (result_code != DnsProxyQueryResult) {
fread(&size, 1, sizeof(size), proxy);
*he = HOST_NOT_FOUND;
return NULL;
}
if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
size = ntohl(size);
memset(hp, 0, sizeof(*hp));
char *ptr = hbuf;
char *hbuf_end = hbuf + hbuflen;
if (ptr + size > hbuf_end) {
goto nospc;
}
if (fread(ptr, 1, size, proxy) != size) return NULL;
hp->h_name = ptr;
ptr += size;
char *aliases_ptrs[MAXALIASES];
char **aliases = &aliases_ptrs[0];
while (1) {
if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
size = ntohl(size);
if (size == 0) {
*aliases = NULL;
break;
}
if (ptr + size > hbuf_end) {
goto nospc;
}
if (fread(ptr, 1, size, proxy) != size) return NULL;
if (aliases < &aliases_ptrs[MAXALIASES - 1]) {
*aliases++ = ptr;
}
ptr += size;
}
// Fix alignment after variable-length data.
ptr = (char*)ALIGN(ptr);
int aliases_len = ((int)(aliases - aliases_ptrs) + 1) * sizeof(*hp->h_aliases);
if (ptr + aliases_len > hbuf_end) {
goto nospc;
}
hp->h_aliases = (void*)ptr;
memcpy(ptr, aliases_ptrs, aliases_len);
ptr += aliases_len;
if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
hp->h_addrtype = ntohl(size);
if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
hp->h_length = ntohl(size);
char *addr_ptrs[MAXADDRS];
char **addr_p = &addr_ptrs[0];
while (1) {
if (fread(&size, 1, sizeof(size), proxy) != sizeof(size)) return NULL;
size = ntohl(size);
if (size == 0) {
*addr_p = NULL;
break;
}
if (ptr + size > hbuf_end) {
goto nospc;
}
if (fread(ptr, 1, size, proxy) != size) return NULL;
if (addr_p < &addr_ptrs[MAXADDRS - 1]) {
*addr_p++ = ptr;
}
ptr += size;
}
// Fix alignment after variable-length data.
ptr = (char*)ALIGN(ptr);
int addrs_len = ((int)(addr_p - addr_ptrs) + 1) * sizeof(*hp->h_addr_list);
if (ptr + addrs_len > hbuf_end) {
goto nospc;
}
hp->h_addr_list = (void*)ptr;
memcpy(ptr, addr_ptrs, addrs_len);
*he = NETDB_SUCCESS;
return hp;
nospc:
*he = NETDB_INTERNAL;
errno = ENOSPC;
return NULL;
}
static struct hostent *
gethostbyname_internal_real(const char *name, int af, res_state res, struct hostent *hp, char *buf,
size_t buflen, int *he)
{
const char *cp;
struct getnamaddr info;
char hbuf[MAXHOSTNAMELEN];
size_t size;
static const ns_dtab dtab[] = {
NS_FILES_CB(_hf_gethtbyname, NULL)
{ NSSRC_DNS, _dns_gethtbyname, NULL }, /* force -DHESIOD */
NS_NIS_CB(_yp_gethtbyname, NULL)
NS_NULL_CB
};
_DIAGASSERT(name != NULL);
switch (af) {
case AF_INET:
size = NS_INADDRSZ;
break;
case AF_INET6:
size = NS_IN6ADDRSZ;
break;
default:
*he = NETDB_INTERNAL;
errno = EAFNOSUPPORT;
return NULL;
}
if (buflen < size)
goto nospc;
hp->h_addrtype = af;
hp->h_length = (int)size;
/*
* if there aren't any dots, it could be a user-level alias.
* this is also done in res_nquery() since we are not the only
* function that looks up host names.
*/
if (!strchr(name, '.') && (cp = res_hostalias(res, name,
hbuf, sizeof(hbuf))))
name = cp;
/*
* disallow names consisting only of digits/dots, unless
* they end in a dot.
*/
if (isdigit((u_char) name[0]))
for (cp = name;; ++cp) {
if (!*cp) {
if (*--cp == '.')
break;
/*
* All-numeric, no dot at the end.
* Fake up a hostent as if we'd actually
* done a lookup.
*/
goto fake;
}
if (!isdigit((u_char) *cp) && *cp != '.')
break;
}
if ((isxdigit((u_char) name[0]) && strchr(name, ':') != NULL) ||
name[0] == ':')
for (cp = name;; ++cp) {
if (!*cp) {
if (*--cp == '.')
break;
/*
* All-IPv6-legal, no dot at the end.
* Fake up a hostent as if we'd actually
* done a lookup.
*/
goto fake;
}
if (!isxdigit((u_char) *cp) && *cp != ':' && *cp != '.')
break;
}
*he = NETDB_INTERNAL;
info.hp = hp;
info.buf = buf;
info.buflen = buflen;
info.he = he;
if (nsdispatch(&info, dtab, NSDB_HOSTS, "gethostbyname",
default_dns_files, name, strlen(name), af) != NS_SUCCESS)
return NULL;
*he = NETDB_SUCCESS;
return hp;
nospc:
*he = NETDB_INTERNAL;
errno = ENOSPC;
return NULL;
fake:
HENT_ARRAY(hp->h_addr_list, 1, buf, buflen);
HENT_ARRAY(hp->h_aliases, 0, buf, buflen);
hp->h_aliases[0] = NULL;
if (size > buflen)
goto nospc;
if (inet_pton(af, name, buf) <= 0) {
*he = HOST_NOT_FOUND;
return NULL;
}
hp->h_addr_list[0] = buf;
hp->h_addr_list[1] = NULL;
buf += size;
buflen -= size;
HENT_SCOPY(hp->h_name, name, buf, buflen);
if (res->options & RES_USE_INET6)
map_v4v6_hostent(hp, &buf, buf + buflen);
*he = NETDB_SUCCESS;
return hp;
}
// very similar in proxy-ness to android_getaddrinfo_proxy
static struct hostent *
gethostbyname_internal(const char *name, int af, res_state res, struct hostent *hp, char *hbuf,
size_t hbuflen, int *errorp, unsigned netid, unsigned mark)
{
FILE* proxy = android_open_proxy();
if (proxy == NULL) {
// Either we're not supposed to be using the proxy or the proxy is unavailable.
res_setnetid(res, netid);
res_setmark(res, mark);
return gethostbyname_internal_real(name, af, res, hp, hbuf, hbuflen, errorp);
}
netid = __netdClientDispatch.netIdForResolv(netid);
// This is writing to system/netd/server/DnsProxyListener.cpp and changes
// here need to be matched there.
if (fprintf(proxy, "gethostbyname %u %s %d",
netid,
name == NULL ? "^" : name,
af) < 0) {
fclose(proxy);
return NULL;
}
if (fputc(0, proxy) == EOF || fflush(proxy) != 0) {
fclose(proxy);
return NULL;
}
struct hostent* result = android_read_hostent(proxy, hp, hbuf, hbuflen, errorp);
fclose(proxy);
return result;
}
/* The prototype of gethostbyaddr_r is from glibc, not that in netbsd. */
int gethostbyaddr_r(const void *addr, socklen_t len, int af, struct hostent *hp, char *buf,
size_t buflen, struct hostent **result, int *h_errnop)
{
*result = android_gethostbyaddrfornet_proxy_internal(addr, len, af, hp, buf, buflen, h_errnop,
NETID_UNSET, MARK_UNSET);
if (!*result && errno == ENOSPC) {
errno = ERANGE;
return ERANGE;
}
return (*result) ? 0 : -1;
}
static struct hostent *
android_gethostbyaddrfornet_real(const void *addr, socklen_t len, int af, struct hostent *hp,
char *buf, size_t buflen, int *he, unsigned netid, unsigned mark)
{
const u_char *uaddr = (const u_char *)addr;
socklen_t size;
struct getnamaddr info;
static const ns_dtab dtab[] = {
NS_FILES_CB(_hf_gethtbyaddr, NULL)
{ NSSRC_DNS, _dns_gethtbyaddr, NULL }, /* force -DHESIOD */
NS_NIS_CB(_yp_gethtbyaddr, NULL)
NS_NULL_CB
};
_DIAGASSERT(addr != NULL);
if (af == AF_INET6 && len == NS_IN6ADDRSZ &&
(IN6_IS_ADDR_LINKLOCAL((const struct in6_addr *)addr) ||
IN6_IS_ADDR_SITELOCAL((const struct in6_addr *)addr))) {
*he = HOST_NOT_FOUND;
return NULL;
}
if (af == AF_INET6 && len == NS_IN6ADDRSZ &&
(IN6_IS_ADDR_V4MAPPED((const struct in6_addr *)addr) ||
IN6_IS_ADDR_V4COMPAT((const struct in6_addr *)addr))) {
/* Unmap. */
uaddr += NS_IN6ADDRSZ - NS_INADDRSZ;
addr = uaddr;
af = AF_INET;
len = NS_INADDRSZ;
}
switch (af) {
case AF_INET:
size = NS_INADDRSZ;
break;
case AF_INET6:
size = NS_IN6ADDRSZ;
break;
default:
errno = EAFNOSUPPORT;
*he = NETDB_INTERNAL;
return NULL;
}
if (size != len) {
errno = EINVAL;
*he = NETDB_INTERNAL;
return NULL;
}
info.hp = hp;
info.buf = buf;
info.buflen = buflen;
info.he = he;
*he = NETDB_INTERNAL;
if (nsdispatch(&info, dtab, NSDB_HOSTS, "gethostbyaddr",
default_dns_files, uaddr, len, af, netid, mark) != NS_SUCCESS)
return NULL;
*he = NETDB_SUCCESS;
return hp;
}
static struct hostent*
android_gethostbyaddrfornet_proxy_internal(const void* addr, socklen_t len, int af,
struct hostent *hp, char *hbuf, size_t hbuflen, int *he,
unsigned netid, unsigned mark)
{
FILE* proxy = android_open_proxy();
if (proxy == NULL) {
// Either we're not supposed to be using the proxy or the proxy is unavailable.
return android_gethostbyaddrfornet_real(addr,len, af, hp, hbuf, hbuflen, he, netid, mark);
}
char buf[INET6_ADDRSTRLEN]; //big enough for IPv4 and IPv6
const char * addrStr = inet_ntop(af, addr, buf, sizeof(buf));
if (addrStr == NULL) {
fclose(proxy);
return NULL;
}
netid = __netdClientDispatch.netIdForResolv(netid);
if (fprintf(proxy, "gethostbyaddr %s %d %d %u",
addrStr, len, af, netid) < 0) {
fclose(proxy);
return NULL;
}
if (fputc(0, proxy) == EOF || fflush(proxy) != 0) {
fclose(proxy);
return NULL;
}
struct hostent *result = android_read_hostent(proxy, hp, hbuf, hbuflen, he);
fclose(proxy);
return result;
}
struct hostent*
netbsd_gethostent_r(FILE *hf, struct hostent *hent, char *buf, size_t buflen, int *he)
{
char *p, *name;
char *cp, **q;
int af, len;
size_t anum;
char **aliases;
size_t maxaliases;
struct in6_addr host_addr;
if (hf == NULL) {
*he = NETDB_INTERNAL;
errno = EINVAL;
return NULL;
}
p = NULL;
setup(aliases, maxaliases);
/* Allocate a new space to read file lines like upstream does.
* To keep reentrancy we cannot use __res_get_static()->hostbuf here,
* as the buffer may be used to store content for a previous hostent
* returned by non-reentrant functions like gethostbyname().
*/
const size_t line_buf_size = sizeof(__res_get_static()->hostbuf);
if ((p = malloc(line_buf_size)) == NULL) {
goto nospc;
}
for (;;) {
if (!fgets(p, line_buf_size, hf)) {
free(p);
free(aliases);
*he = HOST_NOT_FOUND;
return NULL;
}
if (*p == '#') {
continue;
}
if (!(cp = strpbrk(p, "#\n"))) {
continue;
}
*cp = '\0';
if (!(cp = strpbrk(p, " \t")))
continue;
*cp++ = '\0';
if (inet_pton(AF_INET6, p, &host_addr) > 0) {
af = AF_INET6;
len = NS_IN6ADDRSZ;
} else {
if (inet_pton(AF_INET, p, &host_addr) <= 0)
continue;
res_state res = __res_get_state();
if (res == NULL)
goto nospc;
if (res->options & RES_USE_INET6) {
map_v4v6_address(buf, buf);
af = AF_INET6;
len = NS_IN6ADDRSZ;
} else {
af = AF_INET;
len = NS_INADDRSZ;
}
__res_put_state(res);
}
/* if this is not something we're looking for, skip it. */
if (hent->h_addrtype != 0 && hent->h_addrtype != af)
continue;
if (hent->h_length != 0 && hent->h_length != len)
continue;
while (*cp == ' ' || *cp == '\t')
cp++;
if ((cp = strpbrk(name = cp, " \t")) != NULL)
*cp++ = '\0';
q = aliases;
while (cp && *cp) {
if (*cp == ' ' || *cp == '\t') {
cp++;
continue;
}
addalias(q, cp, aliases, maxaliases);
if ((cp = strpbrk(cp, " \t")) != NULL)
*cp++ = '\0';
}
break;
}
hent->h_length = len;
hent->h_addrtype = af;
HENT_ARRAY(hent->h_addr_list, 1, buf, buflen);
anum = (size_t)(q - aliases);
HENT_ARRAY(hent->h_aliases, anum, buf, buflen);
HENT_COPY(hent->h_addr_list[0], &host_addr, hent->h_length, buf,
buflen);
hent->h_addr_list[1] = NULL;
HENT_SCOPY(hent->h_name, name, buf, buflen);
for (size_t i = 0; i < anum; i++)
HENT_SCOPY(hent->h_aliases[i], aliases[i], buf, buflen);
hent->h_aliases[anum] = NULL;
*he = NETDB_SUCCESS;
free(p);
free(aliases);
return hent;
nospc:
free(p);
free(aliases);
errno = ENOSPC;
*he = NETDB_INTERNAL;
return NULL;
}
static void
map_v4v6_address(const char *src, char *dst)
{
u_char *p = (u_char *)dst;
char tmp[NS_INADDRSZ];
int i;
_DIAGASSERT(src != NULL);
_DIAGASSERT(dst != NULL);
/* Stash a temporary copy so our caller can update in place. */
(void)memcpy(tmp, src, NS_INADDRSZ);
/* Mark this ipv6 addr as a mapped ipv4. */
for (i = 0; i < 10; i++)
*p++ = 0x00;
*p++ = 0xff;
*p++ = 0xff;
/* Retrieve the saved copy and we're done. */
(void)memcpy(p, tmp, NS_INADDRSZ);
}
static void
map_v4v6_hostent(struct hostent *hp, char **bpp, char *ep)
{
char **ap;
_DIAGASSERT(hp != NULL);
_DIAGASSERT(bpp != NULL);
_DIAGASSERT(ep != NULL);
if (hp->h_addrtype != AF_INET || hp->h_length != NS_INADDRSZ)
return;
hp->h_addrtype = AF_INET6;
hp->h_length = NS_IN6ADDRSZ;
for (ap = hp->h_addr_list; *ap; ap++) {
int i = (int)(sizeof(align) -
(size_t)((u_long)*bpp % sizeof(align)));
if (ep - *bpp < (i + NS_IN6ADDRSZ)) {
/* Out of memory. Truncate address list here. XXX */
*ap = NULL;
return;
}
*bpp += i;
map_v4v6_address(*ap, *bpp);
*ap = *bpp;
*bpp += NS_IN6ADDRSZ;
}
}
static void
addrsort(char **ap, int num, res_state res)
{
int i, j;
char **p;
short aval[MAXADDRS];
int needsort = 0;
_DIAGASSERT(ap != NULL);
p = ap;
for (i = 0; i < num; i++, p++) {
for (j = 0 ; (unsigned)j < res->nsort; j++)
if (res->sort_list[j].addr.s_addr ==
(((struct in_addr *)(void *)(*p))->s_addr &
res->sort_list[j].mask))
break;
aval[i] = j;
if (needsort == 0 && i > 0 && j < aval[i-1])
needsort = i;
}
if (!needsort)
return;
while (needsort < num) {
for (j = needsort - 1; j >= 0; j--) {
if (aval[j] > aval[j+1]) {
char *hp;
i = aval[j];
aval[j] = aval[j+1];
aval[j+1] = i;
hp = ap[j];
ap[j] = ap[j+1];
ap[j+1] = hp;
} else
break;
}
needsort++;
}
}
/*ARGSUSED*/
static int
_dns_gethtbyname(void *rv, void *cb_data, va_list ap)
{
querybuf *buf;
int n, type;
struct hostent *hp;
const char *name;
res_state res;
struct getnamaddr *info = rv;
_DIAGASSERT(rv != NULL);
name = va_arg(ap, char *);
/* NOSTRICT skip string len */(void)va_arg(ap, int);
info->hp->h_addrtype = va_arg(ap, int);
switch (info->hp->h_addrtype) {
case AF_INET:
info->hp->h_length = NS_INADDRSZ;
type = T_A;
break;
case AF_INET6:
info->hp->h_length = NS_IN6ADDRSZ;
type = T_AAAA;
break;
default:
return NS_UNAVAIL;
}
buf = malloc(sizeof(*buf));
if (buf == NULL) {
*info->he = NETDB_INTERNAL;
return NS_NOTFOUND;
}
res = __res_get_state();
if (res == NULL) {
free(buf);
return NS_NOTFOUND;
}
n = res_nsearch(res, name, C_IN, type, buf->buf, (int)sizeof(buf->buf));
if (n < 0) {
free(buf);
debugprintf("res_nsearch failed (%d)\n", res, n);
__res_put_state(res);
return NS_NOTFOUND;
}
hp = getanswer(buf, n, name, type, res, info->hp, info->buf,
info->buflen, info->he);
free(buf);
__res_put_state(res);
if (hp == NULL)
switch (*info->he) {
case HOST_NOT_FOUND:
return NS_NOTFOUND;
case TRY_AGAIN:
return NS_TRYAGAIN;
default:
return NS_UNAVAIL;
}
return NS_SUCCESS;
}
/*ARGSUSED*/
static int
_dns_gethtbyaddr(void *rv, void *cb_data, va_list ap)
{
char qbuf[MAXDNAME + 1], *qp, *ep;
int n;
querybuf *buf;
struct hostent *hp;
const unsigned char *uaddr;
int advance;
res_state res;
char *bf;
size_t blen;
struct getnamaddr *info = rv;
unsigned netid, mark;
_DIAGASSERT(rv != NULL);
uaddr = va_arg(ap, unsigned char *);
info->hp->h_length = va_arg(ap, int);
info->hp->h_addrtype = va_arg(ap, int);
netid = va_arg(ap, unsigned);
mark = va_arg(ap, unsigned);
switch (info->hp->h_addrtype) {
case AF_INET:
(void)snprintf(qbuf, sizeof(qbuf), "%u.%u.%u.%u.in-addr.arpa",
(uaddr[3] & 0xff), (uaddr[2] & 0xff),
(uaddr[1] & 0xff), (uaddr[0] & 0xff));
break;
case AF_INET6:
qp = qbuf;
ep = qbuf + sizeof(qbuf) - 1;
for (n = NS_IN6ADDRSZ - 1; n >= 0; n--) {
advance = snprintf(qp, (size_t)(ep - qp), "%x.%x.",
uaddr[n] & 0xf,
((unsigned int)uaddr[n] >> 4) & 0xf);
if (advance > 0 && qp + advance < ep)
qp += advance;
else {
*info->he = NETDB_INTERNAL;
return NS_NOTFOUND;
}
}
if (strlcat(qbuf, "ip6.arpa", sizeof(qbuf)) >= sizeof(qbuf)) {
*info->he = NETDB_INTERNAL;
return NS_NOTFOUND;
}
break;
default:
return NS_UNAVAIL;
}
buf = malloc(sizeof(*buf));
if (buf == NULL) {
*info->he = NETDB_INTERNAL;
return NS_NOTFOUND;
}
res = __res_get_state();
if (res == NULL) {
free(buf);
return NS_NOTFOUND;
}
res_setnetid(res, netid);
res_setmark(res, mark);
n = res_nquery(res, qbuf, C_IN, T_PTR, buf->buf, (int)sizeof(buf->buf));
if (n < 0) {
free(buf);
debugprintf("res_nquery failed (%d)\n", res, n);
__res_put_state(res);
return NS_NOTFOUND;
}
hp = getanswer(buf, n, qbuf, T_PTR, res, info->hp, info->buf,
info->buflen, info->he);
free(buf);
if (hp == NULL) {
__res_put_state(res);
switch (*info->he) {
case HOST_NOT_FOUND:
return NS_NOTFOUND;
case TRY_AGAIN:
return NS_TRYAGAIN;
default:
return NS_UNAVAIL;
}
}
bf = (void *)(hp->h_addr_list + 2);
blen = (size_t)(bf - info->buf);
if (blen + info->hp->h_length > info->buflen)
goto nospc;
hp->h_addr_list[0] = bf;
hp->h_addr_list[1] = NULL;
(void)memcpy(bf, uaddr, (size_t)info->hp->h_length);
if (info->hp->h_addrtype == AF_INET && (res->options & RES_USE_INET6)) {
if (blen + NS_IN6ADDRSZ > info->buflen)
goto nospc;
map_v4v6_address(bf, bf);
hp->h_addrtype = AF_INET6;
hp->h_length = NS_IN6ADDRSZ;
}
__res_put_state(res);
*info->he = NETDB_SUCCESS;
return NS_SUCCESS;
nospc:
errno = ENOSPC;
*info->he = NETDB_INTERNAL;
return NS_UNAVAIL;
}
#ifdef YP
/*ARGSUSED*/
static struct hostent *
_yp_hostent(char *line, int af, struct getnamaddr *info)
{
struct in6_addr host_addrs[MAXADDRS];
char **aliases;
size_t maxaliases;
char *p = line;
char *cp, **q, *ptr;
size_t len, anum, i;
int addrok;
int more;
size_t naddrs;
struct hostent *hp = info->hp;
_DIAGASSERT(line != NULL);
hp->h_name = NULL;
hp->h_addrtype = af;
switch (af) {
case AF_INET:
hp->h_length = NS_INADDRSZ;
break;
case AF_INET6:
hp->h_length = NS_IN6ADDRSZ;
break;
default:
return NULL;
}
setup(aliases, maxaliases);
naddrs = 0;
q = aliases;
nextline:
/* check for host_addrs overflow */
if (naddrs >= __arraycount(host_addrs))
goto done;
more = 0;
cp = strpbrk(p, " \t");
if (cp == NULL)
goto done;
*cp++ = '\0';
/* p has should have an address */
addrok = inet_pton(af, p, &host_addrs[naddrs]);
if (addrok != 1) {
/* skip to the next line */
while (cp && *cp) {
if (*cp == '\n') {
cp++;
goto nextline;
}
cp++;
}
goto done;
}
naddrs++;
while (*cp == ' ' || *cp == '\t')
cp++;
p = cp;
cp = strpbrk(p, " \t\n");
if (cp != NULL) {
if (*cp == '\n')
more = 1;
*cp++ = '\0';
}
if (!hp->h_name)
hp->h_name = p;
else if (strcmp(hp->h_name, p) == 0)
;
else
addalias(q, p, aliases, maxaliases);
p = cp;
if (more)
goto nextline;
while (cp && *cp) {
if (*cp == ' ' || *cp == '\t') {
cp++;
continue;
}
if (*cp == '\n') {
cp++;
goto nextline;
}
addalias(q, cp, aliases, maxaliases);
cp = strpbrk(cp, " \t");
if (cp != NULL)
*cp++ = '\0';
}
done:
if (hp->h_name == NULL) {
free(aliases);
return NULL;
}
ptr = info->buf;
len = info->buflen;
anum = (size_t)(q - aliases);
HENT_ARRAY(hp->h_addr_list, naddrs, ptr, len);
HENT_ARRAY(hp->h_aliases, anum, ptr, len);
for (i = 0; i < naddrs; i++)
HENT_COPY(hp->h_addr_list[i], &host_addrs[i], hp->h_length,
ptr, len);
hp->h_addr_list[naddrs] = NULL;
HENT_SCOPY(hp->h_name, hp->h_name, ptr, len);
for (i = 0; i < anum; i++)
HENT_SCOPY(hp->h_aliases[i], aliases[i], ptr, len);
hp->h_aliases[anum] = NULL;
free(aliases);
return hp;
nospc:
free(aliases);
*info->he = NETDB_INTERNAL;
errno = ENOSPC;
return NULL;
}
/*ARGSUSED*/
int
_yp_gethtbyaddr(void *rv, void *cb_data, va_list ap)
{
struct hostent *hp = NULL;
char *ypcurrent;
int ypcurrentlen, r;
char name[INET6_ADDRSTRLEN]; /* XXX enough? */
const unsigned char *uaddr;
int af;
const char *map;
struct getnamaddr *info = rv;
_DIAGASSERT(rv != NULL);
uaddr = va_arg(ap, unsigned char *);
/* NOSTRICT skip len */(void)va_arg(ap, int);
af = va_arg(ap, int);
if (!__ypdomain) {
if (_yp_check(&__ypdomain) == 0)
return NS_UNAVAIL;
}
/*
* XXX unfortunately, we cannot support IPv6 extended scoped address
* notation here. gethostbyaddr() is not scope-aware. too bad.
*/
if (inet_ntop(af, uaddr, name, (socklen_t)sizeof(name)) == NULL)
return NS_UNAVAIL;
switch (af) {
case AF_INET:
map = "hosts.byaddr";
break;
default:
map = "ipnodes.byaddr";
break;
}
ypcurrent = NULL;
r = yp_match(__ypdomain, map, name,
(int)strlen(name), &ypcurrent, &ypcurrentlen);
if (r == 0)
hp = _yp_hostent(ypcurrent, af, info);
else
hp = NULL;
free(ypcurrent);
if (hp == NULL) {
*info->he = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
return NS_SUCCESS;
}
/*ARGSUSED*/
int
_yp_gethtbyname(void *rv, void *cb_data, va_list ap)
{
struct hostent *hp;
char *ypcurrent;
int ypcurrentlen, r;
const char *name;
int af;
const char *map;
struct getnamaddr *info = rv;
_DIAGASSERT(rv != NULL);
name = va_arg(ap, char *);
/* NOSTRICT skip string len */(void)va_arg(ap, int);
af = va_arg(ap, int);
if (!__ypdomain) {
if (_yp_check(&__ypdomain) == 0)
return NS_UNAVAIL;
}
switch (af) {
case AF_INET:
map = "hosts.byname";
break;
default:
map = "ipnodes.byname";
break;
}
ypcurrent = NULL;
r = yp_match(__ypdomain, map, name,
(int)strlen(name), &ypcurrent, &ypcurrentlen);
if (r == 0)
hp = _yp_hostent(ypcurrent, af, info);
else
hp = NULL;
free(ypcurrent);
if (hp == NULL) {
*info->he = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
return NS_SUCCESS;
}
#endif
/*
* Non-reentrant versions.
*/
struct hostent *
gethostbyname(const char *name)
{
struct hostent *result = NULL;
res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
gethostbyname_r(name, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &result, &h_errno);
return result;
}
struct hostent *
gethostbyname2(const char *name, int af)
{
struct hostent *result = NULL;
res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
gethostbyname2_r(name, af, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &result, &h_errno);
return result;
}
struct hostent *
android_gethostbynamefornet(const char *name, int af, unsigned netid, unsigned mark)
{
struct hostent *hp;
res_state res = __res_get_state();
if (res == NULL)
return NULL;
res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
hp = gethostbyname_internal(name, af, res, &rs->host, rs->hostbuf, sizeof(rs->hostbuf),
&h_errno, netid, mark);
__res_put_state(res);
return hp;
}
struct hostent *
gethostbyaddr(const void *addr, socklen_t len, int af)
{
return android_gethostbyaddrfornet_proxy(addr, len, af, NETID_UNSET, MARK_UNSET);
}
struct hostent *
android_gethostbyaddrfornet(const void *addr, socklen_t len, int af, unsigned netid, unsigned mark)
{
return android_gethostbyaddrfornet_proxy(addr, len, af, netid, mark);
}
__LIBC_HIDDEN__ struct hostent*
android_gethostbyaddrfornet_proxy(const void* addr, socklen_t len, int af,
unsigned netid, unsigned mark)
{
res_static rs = __res_get_static(); /* Use res_static to provide thread-safety. */
return android_gethostbyaddrfornet_proxy_internal(addr, len, af, &rs->host, rs->hostbuf,
sizeof(rs->hostbuf), &h_errno, netid, mark);
}
struct hostent *
gethostent(void)
{
res_static rs = __res_get_static();
if (!rs->hostf) {
sethostent_r(&rs->hostf);
if (!rs->hostf) {
h_errno = NETDB_INTERNAL;
return NULL;
}
}
memset(&rs->host, 0, sizeof(rs->host));
return netbsd_gethostent_r(rs->hostf, &rs->host, rs->hostbuf, sizeof(rs->hostbuf), &h_errno);
}