a798b9f0e1
to gingerbread. Don't treat private IPv4 addresses as being in a non-global scope. The effect of this change is essentially to prefer NATed IPv4 over 6to4.
2169 lines
52 KiB
C
2169 lines
52 KiB
C
/* $NetBSD: getaddrinfo.c,v 1.82 2006/03/25 12:09:40 rpaulo Exp $ */
|
|
/* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */
|
|
|
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/*
|
|
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
|
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* All rights reserved.
|
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*
|
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* Redistribution and use in source and binary forms, with or without
|
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* modification, are permitted provided that the following conditions
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* are met:
|
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* 1. Redistributions of source code must retain the above copyright
|
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* 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 project nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
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* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
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|
*/
|
|
|
|
/*
|
|
* Issues to be discussed:
|
|
* - Thread safe-ness must be checked.
|
|
* - Return values. There are nonstandard return values defined and used
|
|
* in the source code. This is because RFC2553 is silent about which error
|
|
* code must be returned for which situation.
|
|
* - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2
|
|
* says to use inet_aton() to convert IPv4 numeric to binary (alows
|
|
* classful form as a result).
|
|
* current code - disallow classful form for IPv4 (due to use of inet_pton).
|
|
* - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is
|
|
* invalid.
|
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* current code - SEGV on freeaddrinfo(NULL)
|
|
* Note:
|
|
* - We use getipnodebyname() just for thread-safeness. There's no intent
|
|
* to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to
|
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* getipnodebyname().
|
|
* - The code filters out AFs that are not supported by the kernel,
|
|
* when globbing NULL hostname (to loopback, or wildcard). Is it the right
|
|
* thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG
|
|
* in ai_flags?
|
|
* - (post-2553) semantics of AI_ADDRCONFIG itself is too vague.
|
|
* (1) what should we do against numeric hostname (2) what should we do
|
|
* against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready?
|
|
* non-loopback address configured? global address configured?
|
|
* - To avoid search order issue, we have a big amount of code duplicate
|
|
* from gethnamaddr.c and some other places. The issues that there's no
|
|
* lower layer function to lookup "IPv4 or IPv6" record. Calling
|
|
* gethostbyname2 from getaddrinfo will end up in wrong search order, as
|
|
* follows:
|
|
* - The code makes use of following calls when asked to resolver with
|
|
* ai_family = PF_UNSPEC:
|
|
* getipnodebyname(host, AF_INET6);
|
|
* getipnodebyname(host, AF_INET);
|
|
* This will result in the following queries if the node is configure to
|
|
* prefer /etc/hosts than DNS:
|
|
* lookup /etc/hosts for IPv6 address
|
|
* lookup DNS for IPv6 address
|
|
* lookup /etc/hosts for IPv4 address
|
|
* lookup DNS for IPv4 address
|
|
* which may not meet people's requirement.
|
|
* The right thing to happen is to have underlying layer which does
|
|
* PF_UNSPEC lookup (lookup both) and return chain of addrinfos.
|
|
* This would result in a bit of code duplicate with _dns_ghbyname() and
|
|
* friends.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
#include <sys/types.h>
|
|
#include <sys/param.h>
|
|
#include <sys/socket.h>
|
|
#include <net/if.h>
|
|
#include <netinet/in.h>
|
|
#include <arpa/inet.h>
|
|
#include "arpa_nameser.h"
|
|
#include <assert.h>
|
|
#include <ctype.h>
|
|
#include <errno.h>
|
|
#include <netdb.h>
|
|
#include "resolv_private.h"
|
|
#include <stddef.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#include <syslog.h>
|
|
#include <stdarg.h>
|
|
#include "nsswitch.h"
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|
|
|
typedef union sockaddr_union {
|
|
struct sockaddr generic;
|
|
struct sockaddr_in in;
|
|
struct sockaddr_in6 in6;
|
|
} sockaddr_union;
|
|
|
|
#define SUCCESS 0
|
|
#define ANY 0
|
|
#define YES 1
|
|
#define NO 0
|
|
|
|
static const char in_addrany[] = { 0, 0, 0, 0 };
|
|
static const char in_loopback[] = { 127, 0, 0, 1 };
|
|
#ifdef INET6
|
|
static const char in6_addrany[] = {
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
|
|
};
|
|
static const char in6_loopback[] = {
|
|
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1
|
|
};
|
|
#endif
|
|
|
|
static const struct afd {
|
|
int a_af;
|
|
int a_addrlen;
|
|
int a_socklen;
|
|
int a_off;
|
|
const char *a_addrany;
|
|
const char *a_loopback;
|
|
int a_scoped;
|
|
} afdl [] = {
|
|
#ifdef INET6
|
|
{PF_INET6, sizeof(struct in6_addr),
|
|
sizeof(struct sockaddr_in6),
|
|
offsetof(struct sockaddr_in6, sin6_addr),
|
|
in6_addrany, in6_loopback, 1},
|
|
#endif
|
|
{PF_INET, sizeof(struct in_addr),
|
|
sizeof(struct sockaddr_in),
|
|
offsetof(struct sockaddr_in, sin_addr),
|
|
in_addrany, in_loopback, 0},
|
|
{0, 0, 0, 0, NULL, NULL, 0},
|
|
};
|
|
|
|
struct explore {
|
|
int e_af;
|
|
int e_socktype;
|
|
int e_protocol;
|
|
const char *e_protostr;
|
|
int e_wild;
|
|
#define WILD_AF(ex) ((ex)->e_wild & 0x01)
|
|
#define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02)
|
|
#define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04)
|
|
};
|
|
|
|
static const struct explore explore[] = {
|
|
#if 0
|
|
{ PF_LOCAL, 0, ANY, ANY, NULL, 0x01 },
|
|
#endif
|
|
#ifdef INET6
|
|
{ PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
|
|
{ PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
|
|
{ PF_INET6, SOCK_RAW, ANY, NULL, 0x05 },
|
|
#endif
|
|
{ PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
|
|
{ PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
|
|
{ PF_INET, SOCK_RAW, ANY, NULL, 0x05 },
|
|
{ PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 },
|
|
{ PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 },
|
|
{ PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 },
|
|
{ -1, 0, 0, NULL, 0 },
|
|
};
|
|
|
|
#ifdef INET6
|
|
#define PTON_MAX 16
|
|
#else
|
|
#define PTON_MAX 4
|
|
#endif
|
|
|
|
static const ns_src default_dns_files[] = {
|
|
{ NSSRC_FILES, NS_SUCCESS },
|
|
{ NSSRC_DNS, NS_SUCCESS },
|
|
{ 0, 0 }
|
|
};
|
|
|
|
#define MAXPACKET (64*1024)
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|
|
|
typedef union {
|
|
HEADER hdr;
|
|
u_char buf[MAXPACKET];
|
|
} querybuf;
|
|
|
|
struct res_target {
|
|
struct res_target *next;
|
|
const char *name; /* domain name */
|
|
int qclass, qtype; /* class and type of query */
|
|
u_char *answer; /* buffer to put answer */
|
|
int anslen; /* size of answer buffer */
|
|
int n; /* result length */
|
|
};
|
|
|
|
static int str2number(const char *);
|
|
static int explore_fqdn(const struct addrinfo *, const char *,
|
|
const char *, struct addrinfo **);
|
|
static int explore_null(const struct addrinfo *,
|
|
const char *, struct addrinfo **);
|
|
static int explore_numeric(const struct addrinfo *, const char *,
|
|
const char *, struct addrinfo **, const char *);
|
|
static int explore_numeric_scope(const struct addrinfo *, const char *,
|
|
const char *, struct addrinfo **);
|
|
static int get_canonname(const struct addrinfo *,
|
|
struct addrinfo *, const char *);
|
|
static struct addrinfo *get_ai(const struct addrinfo *,
|
|
const struct afd *, const char *);
|
|
static int get_portmatch(const struct addrinfo *, const char *);
|
|
static int get_port(const struct addrinfo *, const char *, int);
|
|
static const struct afd *find_afd(int);
|
|
#ifdef INET6
|
|
static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *);
|
|
#endif
|
|
|
|
static struct addrinfo *getanswer(const querybuf *, int, const char *, int,
|
|
const struct addrinfo *);
|
|
static int _dns_getaddrinfo(void *, void *, va_list);
|
|
static void _sethtent(FILE **);
|
|
static void _endhtent(FILE **);
|
|
static struct addrinfo *_gethtent(FILE **, const char *,
|
|
const struct addrinfo *);
|
|
static int _files_getaddrinfo(void *, void *, va_list);
|
|
|
|
static int res_queryN(const char *, struct res_target *, res_state);
|
|
static int res_searchN(const char *, struct res_target *, res_state);
|
|
static int res_querydomainN(const char *, const char *,
|
|
struct res_target *, res_state);
|
|
|
|
static const char * const ai_errlist[] = {
|
|
"Success",
|
|
"Address family for hostname not supported", /* EAI_ADDRFAMILY */
|
|
"Temporary failure in name resolution", /* EAI_AGAIN */
|
|
"Invalid value for ai_flags", /* EAI_BADFLAGS */
|
|
"Non-recoverable failure in name resolution", /* EAI_FAIL */
|
|
"ai_family not supported", /* EAI_FAMILY */
|
|
"Memory allocation failure", /* EAI_MEMORY */
|
|
"No address associated with hostname", /* EAI_NODATA */
|
|
"hostname nor servname provided, or not known", /* EAI_NONAME */
|
|
"servname not supported for ai_socktype", /* EAI_SERVICE */
|
|
"ai_socktype not supported", /* EAI_SOCKTYPE */
|
|
"System error returned in errno", /* EAI_SYSTEM */
|
|
"Invalid value for hints", /* EAI_BADHINTS */
|
|
"Resolved protocol is unknown", /* EAI_PROTOCOL */
|
|
"Argument buffer overflow", /* EAI_OVERFLOW */
|
|
"Unknown error", /* EAI_MAX */
|
|
};
|
|
|
|
/* XXX macros that make external reference is BAD. */
|
|
|
|
#define GET_AI(ai, afd, addr) \
|
|
do { \
|
|
/* external reference: pai, error, and label free */ \
|
|
(ai) = get_ai(pai, (afd), (addr)); \
|
|
if ((ai) == NULL) { \
|
|
error = EAI_MEMORY; \
|
|
goto free; \
|
|
} \
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
#define GET_PORT(ai, serv) \
|
|
do { \
|
|
/* external reference: error and label free */ \
|
|
error = get_port((ai), (serv), 0); \
|
|
if (error != 0) \
|
|
goto free; \
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
#define GET_CANONNAME(ai, str) \
|
|
do { \
|
|
/* external reference: pai, error and label free */ \
|
|
error = get_canonname(pai, (ai), (str)); \
|
|
if (error != 0) \
|
|
goto free; \
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
#define ERR(err) \
|
|
do { \
|
|
/* external reference: error, and label bad */ \
|
|
error = (err); \
|
|
goto bad; \
|
|
/*NOTREACHED*/ \
|
|
} while (/*CONSTCOND*/0)
|
|
|
|
#define MATCH_FAMILY(x, y, w) \
|
|
((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \
|
|
(y) == PF_UNSPEC)))
|
|
#define MATCH(x, y, w) \
|
|
((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
|
|
|
|
const char *
|
|
gai_strerror(int ecode)
|
|
{
|
|
if (ecode < 0 || ecode > EAI_MAX)
|
|
ecode = EAI_MAX;
|
|
return ai_errlist[ecode];
|
|
}
|
|
|
|
void
|
|
freeaddrinfo(struct addrinfo *ai)
|
|
{
|
|
struct addrinfo *next;
|
|
|
|
assert(ai != NULL);
|
|
|
|
do {
|
|
next = ai->ai_next;
|
|
if (ai->ai_canonname)
|
|
free(ai->ai_canonname);
|
|
/* no need to free(ai->ai_addr) */
|
|
free(ai);
|
|
ai = next;
|
|
} while (ai);
|
|
}
|
|
|
|
static int
|
|
str2number(const char *p)
|
|
{
|
|
char *ep;
|
|
unsigned long v;
|
|
|
|
assert(p != NULL);
|
|
|
|
if (*p == '\0')
|
|
return -1;
|
|
ep = NULL;
|
|
errno = 0;
|
|
v = strtoul(p, &ep, 10);
|
|
if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX)
|
|
return v;
|
|
else
|
|
return -1;
|
|
}
|
|
|
|
/* Determine whether IPv6 connectivity is available. */
|
|
static int
|
|
_have_ipv6() {
|
|
/*
|
|
* Connect a UDP socket to an global unicast IPv6 address. This will
|
|
* cause no network traffic, but will fail fast if the system has no or
|
|
* limited IPv6 connectivity (e.g., only a link-local address).
|
|
*/
|
|
static const struct sockaddr_in6 sin6_test = {
|
|
/* family, port, flow label */
|
|
AF_INET6, 0, 0,
|
|
/* 2000:: */
|
|
{{{ 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }}},
|
|
/* scope ID */
|
|
0};
|
|
sockaddr_union addr_test;
|
|
addr_test.in6 = sin6_test;
|
|
int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP);
|
|
if (s < 0)
|
|
return 0;
|
|
int ret;
|
|
do {
|
|
ret = connect(s, &addr_test.generic, sizeof(addr_test.in6));
|
|
} while (ret < 0 && errno == EINTR);
|
|
int have_ipv6 = (ret == 0);
|
|
do {
|
|
ret = close(s);
|
|
} while (ret < 0 && errno == EINTR);
|
|
return have_ipv6;
|
|
}
|
|
|
|
int
|
|
getaddrinfo(const char *hostname, const char *servname,
|
|
const struct addrinfo *hints, struct addrinfo **res)
|
|
{
|
|
struct addrinfo sentinel;
|
|
struct addrinfo *cur;
|
|
int error = 0;
|
|
struct addrinfo ai;
|
|
struct addrinfo ai0;
|
|
struct addrinfo *pai;
|
|
const struct explore *ex;
|
|
|
|
/* hostname is allowed to be NULL */
|
|
/* servname is allowed to be NULL */
|
|
/* hints is allowed to be NULL */
|
|
assert(res != NULL);
|
|
|
|
memset(&sentinel, 0, sizeof(sentinel));
|
|
cur = &sentinel;
|
|
pai = &ai;
|
|
pai->ai_flags = 0;
|
|
pai->ai_family = PF_UNSPEC;
|
|
pai->ai_socktype = ANY;
|
|
pai->ai_protocol = ANY;
|
|
pai->ai_addrlen = 0;
|
|
pai->ai_canonname = NULL;
|
|
pai->ai_addr = NULL;
|
|
pai->ai_next = NULL;
|
|
|
|
if (hostname == NULL && servname == NULL)
|
|
return EAI_NONAME;
|
|
if (hints) {
|
|
/* error check for hints */
|
|
if (hints->ai_addrlen || hints->ai_canonname ||
|
|
hints->ai_addr || hints->ai_next)
|
|
ERR(EAI_BADHINTS); /* xxx */
|
|
if (hints->ai_flags & ~AI_MASK)
|
|
ERR(EAI_BADFLAGS);
|
|
switch (hints->ai_family) {
|
|
case PF_UNSPEC:
|
|
case PF_INET:
|
|
#ifdef INET6
|
|
case PF_INET6:
|
|
#endif
|
|
break;
|
|
default:
|
|
ERR(EAI_FAMILY);
|
|
}
|
|
memcpy(pai, hints, sizeof(*pai));
|
|
|
|
/*
|
|
* if both socktype/protocol are specified, check if they
|
|
* are meaningful combination.
|
|
*/
|
|
if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) {
|
|
for (ex = explore; ex->e_af >= 0; ex++) {
|
|
if (pai->ai_family != ex->e_af)
|
|
continue;
|
|
if (ex->e_socktype == ANY)
|
|
continue;
|
|
if (ex->e_protocol == ANY)
|
|
continue;
|
|
if (pai->ai_socktype == ex->e_socktype
|
|
&& pai->ai_protocol != ex->e_protocol) {
|
|
ERR(EAI_BADHINTS);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* check for special cases. (1) numeric servname is disallowed if
|
|
* socktype/protocol are left unspecified. (2) servname is disallowed
|
|
* for raw and other inet{,6} sockets.
|
|
*/
|
|
if (MATCH_FAMILY(pai->ai_family, PF_INET, 1)
|
|
#ifdef PF_INET6
|
|
|| MATCH_FAMILY(pai->ai_family, PF_INET6, 1)
|
|
#endif
|
|
) {
|
|
ai0 = *pai; /* backup *pai */
|
|
|
|
if (pai->ai_family == PF_UNSPEC) {
|
|
#ifdef PF_INET6
|
|
pai->ai_family = PF_INET6;
|
|
#else
|
|
pai->ai_family = PF_INET;
|
|
#endif
|
|
}
|
|
error = get_portmatch(pai, servname);
|
|
if (error)
|
|
ERR(error);
|
|
|
|
*pai = ai0;
|
|
}
|
|
|
|
ai0 = *pai;
|
|
|
|
/* NULL hostname, or numeric hostname */
|
|
for (ex = explore; ex->e_af >= 0; ex++) {
|
|
*pai = ai0;
|
|
|
|
/* PF_UNSPEC entries are prepared for DNS queries only */
|
|
if (ex->e_af == PF_UNSPEC)
|
|
continue;
|
|
|
|
if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex)))
|
|
continue;
|
|
if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex)))
|
|
continue;
|
|
if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex)))
|
|
continue;
|
|
|
|
if (pai->ai_family == PF_UNSPEC)
|
|
pai->ai_family = ex->e_af;
|
|
if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
|
|
pai->ai_socktype = ex->e_socktype;
|
|
if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
|
|
pai->ai_protocol = ex->e_protocol;
|
|
|
|
if (hostname == NULL)
|
|
error = explore_null(pai, servname, &cur->ai_next);
|
|
else
|
|
error = explore_numeric_scope(pai, hostname, servname,
|
|
&cur->ai_next);
|
|
|
|
if (error)
|
|
goto free;
|
|
|
|
while (cur->ai_next)
|
|
cur = cur->ai_next;
|
|
}
|
|
|
|
/*
|
|
* XXX
|
|
* If numeric representation of AF1 can be interpreted as FQDN
|
|
* representation of AF2, we need to think again about the code below.
|
|
*/
|
|
if (sentinel.ai_next)
|
|
goto good;
|
|
|
|
if (hostname == NULL)
|
|
ERR(EAI_NODATA);
|
|
if (pai->ai_flags & AI_NUMERICHOST)
|
|
ERR(EAI_NONAME);
|
|
|
|
/*
|
|
* hostname as alphabetical name.
|
|
* we would like to prefer AF_INET6 than AF_INET, so we'll make a
|
|
* outer loop by AFs.
|
|
*/
|
|
for (ex = explore; ex->e_af >= 0; ex++) {
|
|
*pai = ai0;
|
|
|
|
/* require exact match for family field */
|
|
if (pai->ai_family != ex->e_af)
|
|
continue;
|
|
|
|
if (!MATCH(pai->ai_socktype, ex->e_socktype,
|
|
WILD_SOCKTYPE(ex))) {
|
|
continue;
|
|
}
|
|
if (!MATCH(pai->ai_protocol, ex->e_protocol,
|
|
WILD_PROTOCOL(ex))) {
|
|
continue;
|
|
}
|
|
|
|
if (pai->ai_socktype == ANY && ex->e_socktype != ANY)
|
|
pai->ai_socktype = ex->e_socktype;
|
|
if (pai->ai_protocol == ANY && ex->e_protocol != ANY)
|
|
pai->ai_protocol = ex->e_protocol;
|
|
|
|
error = explore_fqdn(pai, hostname, servname,
|
|
&cur->ai_next);
|
|
|
|
while (cur && cur->ai_next)
|
|
cur = cur->ai_next;
|
|
}
|
|
|
|
/* XXX */
|
|
if (sentinel.ai_next)
|
|
error = 0;
|
|
|
|
if (error)
|
|
goto free;
|
|
if (error == 0) {
|
|
if (sentinel.ai_next) {
|
|
good:
|
|
*res = sentinel.ai_next;
|
|
return SUCCESS;
|
|
} else
|
|
error = EAI_FAIL;
|
|
}
|
|
free:
|
|
bad:
|
|
if (sentinel.ai_next)
|
|
freeaddrinfo(sentinel.ai_next);
|
|
*res = NULL;
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* FQDN hostname, DNS lookup
|
|
*/
|
|
static int
|
|
explore_fqdn(const struct addrinfo *pai, const char *hostname,
|
|
const char *servname, struct addrinfo **res)
|
|
{
|
|
struct addrinfo *result;
|
|
struct addrinfo *cur;
|
|
int error = 0;
|
|
static const ns_dtab dtab[] = {
|
|
NS_FILES_CB(_files_getaddrinfo, NULL)
|
|
{ NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */
|
|
NS_NIS_CB(_yp_getaddrinfo, NULL)
|
|
{ 0, 0, 0 }
|
|
};
|
|
|
|
assert(pai != NULL);
|
|
/* hostname may be NULL */
|
|
/* servname may be NULL */
|
|
assert(res != NULL);
|
|
|
|
result = NULL;
|
|
|
|
/*
|
|
* if the servname does not match socktype/protocol, ignore it.
|
|
*/
|
|
if (get_portmatch(pai, servname) != 0)
|
|
return 0;
|
|
|
|
switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
|
|
default_dns_files, hostname, pai)) {
|
|
case NS_TRYAGAIN:
|
|
error = EAI_AGAIN;
|
|
goto free;
|
|
case NS_UNAVAIL:
|
|
error = EAI_FAIL;
|
|
goto free;
|
|
case NS_NOTFOUND:
|
|
error = EAI_NODATA;
|
|
goto free;
|
|
case NS_SUCCESS:
|
|
error = 0;
|
|
for (cur = result; cur; cur = cur->ai_next) {
|
|
GET_PORT(cur, servname);
|
|
/* canonname should be filled already */
|
|
}
|
|
break;
|
|
}
|
|
|
|
*res = result;
|
|
|
|
return 0;
|
|
|
|
free:
|
|
if (result)
|
|
freeaddrinfo(result);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* hostname == NULL.
|
|
* passive socket -> anyaddr (0.0.0.0 or ::)
|
|
* non-passive socket -> localhost (127.0.0.1 or ::1)
|
|
*/
|
|
static int
|
|
explore_null(const struct addrinfo *pai, const char *servname,
|
|
struct addrinfo **res)
|
|
{
|
|
int s;
|
|
const struct afd *afd;
|
|
struct addrinfo *cur;
|
|
struct addrinfo sentinel;
|
|
int error;
|
|
|
|
assert(pai != NULL);
|
|
/* servname may be NULL */
|
|
assert(res != NULL);
|
|
|
|
*res = NULL;
|
|
sentinel.ai_next = NULL;
|
|
cur = &sentinel;
|
|
|
|
/*
|
|
* filter out AFs that are not supported by the kernel
|
|
* XXX errno?
|
|
*/
|
|
s = socket(pai->ai_family, SOCK_DGRAM, 0);
|
|
if (s < 0) {
|
|
if (errno != EMFILE)
|
|
return 0;
|
|
} else
|
|
close(s);
|
|
|
|
/*
|
|
* if the servname does not match socktype/protocol, ignore it.
|
|
*/
|
|
if (get_portmatch(pai, servname) != 0)
|
|
return 0;
|
|
|
|
afd = find_afd(pai->ai_family);
|
|
if (afd == NULL)
|
|
return 0;
|
|
|
|
if (pai->ai_flags & AI_PASSIVE) {
|
|
GET_AI(cur->ai_next, afd, afd->a_addrany);
|
|
/* xxx meaningless?
|
|
* GET_CANONNAME(cur->ai_next, "anyaddr");
|
|
*/
|
|
GET_PORT(cur->ai_next, servname);
|
|
} else {
|
|
GET_AI(cur->ai_next, afd, afd->a_loopback);
|
|
/* xxx meaningless?
|
|
* GET_CANONNAME(cur->ai_next, "localhost");
|
|
*/
|
|
GET_PORT(cur->ai_next, servname);
|
|
}
|
|
cur = cur->ai_next;
|
|
|
|
*res = sentinel.ai_next;
|
|
return 0;
|
|
|
|
free:
|
|
if (sentinel.ai_next)
|
|
freeaddrinfo(sentinel.ai_next);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* numeric hostname
|
|
*/
|
|
static int
|
|
explore_numeric(const struct addrinfo *pai, const char *hostname,
|
|
const char *servname, struct addrinfo **res, const char *canonname)
|
|
{
|
|
const struct afd *afd;
|
|
struct addrinfo *cur;
|
|
struct addrinfo sentinel;
|
|
int error;
|
|
char pton[PTON_MAX];
|
|
|
|
assert(pai != NULL);
|
|
/* hostname may be NULL */
|
|
/* servname may be NULL */
|
|
assert(res != NULL);
|
|
|
|
*res = NULL;
|
|
sentinel.ai_next = NULL;
|
|
cur = &sentinel;
|
|
|
|
/*
|
|
* if the servname does not match socktype/protocol, ignore it.
|
|
*/
|
|
if (get_portmatch(pai, servname) != 0)
|
|
return 0;
|
|
|
|
afd = find_afd(pai->ai_family);
|
|
if (afd == NULL)
|
|
return 0;
|
|
|
|
switch (afd->a_af) {
|
|
#if 0 /*X/Open spec*/
|
|
case AF_INET:
|
|
if (inet_aton(hostname, (struct in_addr *)pton) == 1) {
|
|
if (pai->ai_family == afd->a_af ||
|
|
pai->ai_family == PF_UNSPEC /*?*/) {
|
|
GET_AI(cur->ai_next, afd, pton);
|
|
GET_PORT(cur->ai_next, servname);
|
|
if ((pai->ai_flags & AI_CANONNAME)) {
|
|
/*
|
|
* Set the numeric address itself as
|
|
* the canonical name, based on a
|
|
* clarification in rfc2553bis-03.
|
|
*/
|
|
GET_CANONNAME(cur->ai_next, canonname);
|
|
}
|
|
while (cur && cur->ai_next)
|
|
cur = cur->ai_next;
|
|
} else
|
|
ERR(EAI_FAMILY); /*xxx*/
|
|
}
|
|
break;
|
|
#endif
|
|
default:
|
|
if (inet_pton(afd->a_af, hostname, pton) == 1) {
|
|
if (pai->ai_family == afd->a_af ||
|
|
pai->ai_family == PF_UNSPEC /*?*/) {
|
|
GET_AI(cur->ai_next, afd, pton);
|
|
GET_PORT(cur->ai_next, servname);
|
|
if ((pai->ai_flags & AI_CANONNAME)) {
|
|
/*
|
|
* Set the numeric address itself as
|
|
* the canonical name, based on a
|
|
* clarification in rfc2553bis-03.
|
|
*/
|
|
GET_CANONNAME(cur->ai_next, canonname);
|
|
}
|
|
while (cur->ai_next)
|
|
cur = cur->ai_next;
|
|
} else
|
|
ERR(EAI_FAMILY); /*xxx*/
|
|
}
|
|
break;
|
|
}
|
|
|
|
*res = sentinel.ai_next;
|
|
return 0;
|
|
|
|
free:
|
|
bad:
|
|
if (sentinel.ai_next)
|
|
freeaddrinfo(sentinel.ai_next);
|
|
return error;
|
|
}
|
|
|
|
/*
|
|
* numeric hostname with scope
|
|
*/
|
|
static int
|
|
explore_numeric_scope(const struct addrinfo *pai, const char *hostname,
|
|
const char *servname, struct addrinfo **res)
|
|
{
|
|
#if !defined(SCOPE_DELIMITER) || !defined(INET6)
|
|
return explore_numeric(pai, hostname, servname, res, hostname);
|
|
#else
|
|
const struct afd *afd;
|
|
struct addrinfo *cur;
|
|
int error;
|
|
char *cp, *hostname2 = NULL, *scope, *addr;
|
|
struct sockaddr_in6 *sin6;
|
|
|
|
assert(pai != NULL);
|
|
/* hostname may be NULL */
|
|
/* servname may be NULL */
|
|
assert(res != NULL);
|
|
|
|
/*
|
|
* if the servname does not match socktype/protocol, ignore it.
|
|
*/
|
|
if (get_portmatch(pai, servname) != 0)
|
|
return 0;
|
|
|
|
afd = find_afd(pai->ai_family);
|
|
if (afd == NULL)
|
|
return 0;
|
|
|
|
if (!afd->a_scoped)
|
|
return explore_numeric(pai, hostname, servname, res, hostname);
|
|
|
|
cp = strchr(hostname, SCOPE_DELIMITER);
|
|
if (cp == NULL)
|
|
return explore_numeric(pai, hostname, servname, res, hostname);
|
|
|
|
/*
|
|
* Handle special case of <scoped_address><delimiter><scope id>
|
|
*/
|
|
hostname2 = strdup(hostname);
|
|
if (hostname2 == NULL)
|
|
return EAI_MEMORY;
|
|
/* terminate at the delimiter */
|
|
hostname2[cp - hostname] = '\0';
|
|
addr = hostname2;
|
|
scope = cp + 1;
|
|
|
|
error = explore_numeric(pai, addr, servname, res, hostname);
|
|
if (error == 0) {
|
|
u_int32_t scopeid;
|
|
|
|
for (cur = *res; cur; cur = cur->ai_next) {
|
|
if (cur->ai_family != AF_INET6)
|
|
continue;
|
|
sin6 = (struct sockaddr_in6 *)(void *)cur->ai_addr;
|
|
if (ip6_str2scopeid(scope, sin6, &scopeid) == -1) {
|
|
free(hostname2);
|
|
return(EAI_NODATA); /* XXX: is return OK? */
|
|
}
|
|
sin6->sin6_scope_id = scopeid;
|
|
}
|
|
}
|
|
|
|
free(hostname2);
|
|
|
|
return error;
|
|
#endif
|
|
}
|
|
|
|
static int
|
|
get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
|
|
{
|
|
|
|
assert(pai != NULL);
|
|
assert(ai != NULL);
|
|
assert(str != NULL);
|
|
|
|
if ((pai->ai_flags & AI_CANONNAME) != 0) {
|
|
ai->ai_canonname = strdup(str);
|
|
if (ai->ai_canonname == NULL)
|
|
return EAI_MEMORY;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static struct addrinfo *
|
|
get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr)
|
|
{
|
|
char *p;
|
|
struct addrinfo *ai;
|
|
|
|
assert(pai != NULL);
|
|
assert(afd != NULL);
|
|
assert(addr != NULL);
|
|
|
|
ai = (struct addrinfo *)malloc(sizeof(struct addrinfo)
|
|
+ (afd->a_socklen));
|
|
if (ai == NULL)
|
|
return NULL;
|
|
|
|
memcpy(ai, pai, sizeof(struct addrinfo));
|
|
ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
|
|
memset(ai->ai_addr, 0, (size_t)afd->a_socklen);
|
|
|
|
#ifdef HAVE_SA_LEN
|
|
ai->ai_addr->sa_len = afd->a_socklen;
|
|
#endif
|
|
|
|
ai->ai_addrlen = afd->a_socklen;
|
|
#if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__)
|
|
ai->__ai_pad0 = 0;
|
|
#endif
|
|
ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
|
|
p = (char *)(void *)(ai->ai_addr);
|
|
memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
|
|
return ai;
|
|
}
|
|
|
|
static int
|
|
get_portmatch(const struct addrinfo *ai, const char *servname)
|
|
{
|
|
|
|
assert(ai != NULL);
|
|
/* servname may be NULL */
|
|
|
|
return get_port(ai, servname, 1);
|
|
}
|
|
|
|
static int
|
|
get_port(const struct addrinfo *ai, const char *servname, int matchonly)
|
|
{
|
|
const char *proto;
|
|
struct servent *sp;
|
|
int port;
|
|
int allownumeric;
|
|
|
|
assert(ai != NULL);
|
|
/* servname may be NULL */
|
|
|
|
if (servname == NULL)
|
|
return 0;
|
|
switch (ai->ai_family) {
|
|
case AF_INET:
|
|
#ifdef AF_INET6
|
|
case AF_INET6:
|
|
#endif
|
|
break;
|
|
default:
|
|
return 0;
|
|
}
|
|
|
|
switch (ai->ai_socktype) {
|
|
case SOCK_RAW:
|
|
return EAI_SERVICE;
|
|
case SOCK_DGRAM:
|
|
case SOCK_STREAM:
|
|
allownumeric = 1;
|
|
break;
|
|
case ANY:
|
|
#if 1 /* ANDROID-SPECIFIC CHANGE TO MATCH GLIBC */
|
|
allownumeric = 1;
|
|
#else
|
|
allownumeric = 0;
|
|
#endif
|
|
break;
|
|
default:
|
|
return EAI_SOCKTYPE;
|
|
}
|
|
|
|
port = str2number(servname);
|
|
if (port >= 0) {
|
|
if (!allownumeric)
|
|
return EAI_SERVICE;
|
|
if (port < 0 || port > 65535)
|
|
return EAI_SERVICE;
|
|
port = htons(port);
|
|
} else {
|
|
if (ai->ai_flags & AI_NUMERICSERV)
|
|
return EAI_NONAME;
|
|
|
|
switch (ai->ai_socktype) {
|
|
case SOCK_DGRAM:
|
|
proto = "udp";
|
|
break;
|
|
case SOCK_STREAM:
|
|
proto = "tcp";
|
|
break;
|
|
default:
|
|
proto = NULL;
|
|
break;
|
|
}
|
|
|
|
if ((sp = getservbyname(servname, proto)) == NULL)
|
|
return EAI_SERVICE;
|
|
port = sp->s_port;
|
|
}
|
|
|
|
if (!matchonly) {
|
|
switch (ai->ai_family) {
|
|
case AF_INET:
|
|
((struct sockaddr_in *)(void *)
|
|
ai->ai_addr)->sin_port = port;
|
|
break;
|
|
#ifdef INET6
|
|
case AF_INET6:
|
|
((struct sockaddr_in6 *)(void *)
|
|
ai->ai_addr)->sin6_port = port;
|
|
break;
|
|
#endif
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct afd *
|
|
find_afd(int af)
|
|
{
|
|
const struct afd *afd;
|
|
|
|
if (af == PF_UNSPEC)
|
|
return NULL;
|
|
for (afd = afdl; afd->a_af; afd++) {
|
|
if (afd->a_af == af)
|
|
return afd;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
#ifdef INET6
|
|
/* convert a string to a scope identifier. XXX: IPv6 specific */
|
|
static int
|
|
ip6_str2scopeid(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid)
|
|
{
|
|
u_long lscopeid;
|
|
struct in6_addr *a6;
|
|
char *ep;
|
|
|
|
assert(scope != NULL);
|
|
assert(sin6 != NULL);
|
|
assert(scopeid != NULL);
|
|
|
|
a6 = &sin6->sin6_addr;
|
|
|
|
/* empty scopeid portion is invalid */
|
|
if (*scope == '\0')
|
|
return -1;
|
|
|
|
if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) {
|
|
/*
|
|
* We currently assume a one-to-one mapping between links
|
|
* and interfaces, so we simply use interface indices for
|
|
* like-local scopes.
|
|
*/
|
|
*scopeid = if_nametoindex(scope);
|
|
if (*scopeid == 0)
|
|
goto trynumeric;
|
|
return 0;
|
|
}
|
|
|
|
/* still unclear about literal, allow numeric only - placeholder */
|
|
if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6))
|
|
goto trynumeric;
|
|
if (IN6_IS_ADDR_MC_ORGLOCAL(a6))
|
|
goto trynumeric;
|
|
else
|
|
goto trynumeric; /* global */
|
|
|
|
/* try to convert to a numeric id as a last resort */
|
|
trynumeric:
|
|
errno = 0;
|
|
lscopeid = strtoul(scope, &ep, 10);
|
|
*scopeid = (u_int32_t)(lscopeid & 0xffffffffUL);
|
|
if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid)
|
|
return 0;
|
|
else
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
/* code duplicate with gethnamaddr.c */
|
|
|
|
static const char AskedForGot[] =
|
|
"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
|
|
|
|
static struct addrinfo *
|
|
getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
|
|
const struct addrinfo *pai)
|
|
{
|
|
struct addrinfo sentinel, *cur;
|
|
struct addrinfo ai;
|
|
const struct afd *afd;
|
|
char *canonname;
|
|
const HEADER *hp;
|
|
const u_char *cp;
|
|
int n;
|
|
const u_char *eom;
|
|
char *bp, *ep;
|
|
int type, class, ancount, qdcount;
|
|
int haveanswer, had_error;
|
|
char tbuf[MAXDNAME];
|
|
int (*name_ok) (const char *);
|
|
char hostbuf[8*1024];
|
|
|
|
assert(answer != NULL);
|
|
assert(qname != NULL);
|
|
assert(pai != NULL);
|
|
|
|
memset(&sentinel, 0, sizeof(sentinel));
|
|
cur = &sentinel;
|
|
|
|
canonname = NULL;
|
|
eom = answer->buf + anslen;
|
|
switch (qtype) {
|
|
case T_A:
|
|
case T_AAAA:
|
|
case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/
|
|
name_ok = res_hnok;
|
|
break;
|
|
default:
|
|
return NULL; /* XXX should be abort(); */
|
|
}
|
|
/*
|
|
* find first satisfactory answer
|
|
*/
|
|
hp = &answer->hdr;
|
|
ancount = ntohs(hp->ancount);
|
|
qdcount = ntohs(hp->qdcount);
|
|
bp = hostbuf;
|
|
ep = hostbuf + sizeof hostbuf;
|
|
cp = answer->buf + HFIXEDSZ;
|
|
if (qdcount != 1) {
|
|
h_errno = NO_RECOVERY;
|
|
return (NULL);
|
|
}
|
|
n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
|
|
if ((n < 0) || !(*name_ok)(bp)) {
|
|
h_errno = NO_RECOVERY;
|
|
return (NULL);
|
|
}
|
|
cp += n + QFIXEDSZ;
|
|
if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) {
|
|
/* 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 = strlen(bp) + 1; /* for the \0 */
|
|
if (n >= MAXHOSTNAMELEN) {
|
|
h_errno = NO_RECOVERY;
|
|
return (NULL);
|
|
}
|
|
canonname = bp;
|
|
bp += n;
|
|
/* The qname can be abbreviated, but h_name is now absolute. */
|
|
qname = canonname;
|
|
}
|
|
haveanswer = 0;
|
|
had_error = 0;
|
|
while (ancount-- > 0 && cp < eom && !had_error) {
|
|
n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
|
|
if ((n < 0) || !(*name_ok)(bp)) {
|
|
had_error++;
|
|
continue;
|
|
}
|
|
cp += n; /* name */
|
|
type = _getshort(cp);
|
|
cp += INT16SZ; /* type */
|
|
class = _getshort(cp);
|
|
cp += INT16SZ + INT32SZ; /* class, TTL */
|
|
n = _getshort(cp);
|
|
cp += INT16SZ; /* len */
|
|
if (class != C_IN) {
|
|
/* XXX - debug? syslog? */
|
|
cp += n;
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) &&
|
|
type == T_CNAME) {
|
|
n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
|
|
if ((n < 0) || !(*name_ok)(tbuf)) {
|
|
had_error++;
|
|
continue;
|
|
}
|
|
cp += n;
|
|
/* Get canonical name. */
|
|
n = strlen(tbuf) + 1; /* for the \0 */
|
|
if (n > ep - bp || n >= MAXHOSTNAMELEN) {
|
|
had_error++;
|
|
continue;
|
|
}
|
|
strlcpy(bp, tbuf, (size_t)(ep - bp));
|
|
canonname = bp;
|
|
bp += n;
|
|
continue;
|
|
}
|
|
if (qtype == T_ANY) {
|
|
if (!(type == T_A || type == T_AAAA)) {
|
|
cp += n;
|
|
continue;
|
|
}
|
|
} else 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_A:
|
|
case T_AAAA:
|
|
if (strcasecmp(canonname, bp) != 0) {
|
|
syslog(LOG_NOTICE|LOG_AUTH,
|
|
AskedForGot, canonname, bp);
|
|
cp += n;
|
|
continue; /* XXX - had_error++ ? */
|
|
}
|
|
if (type == T_A && n != INADDRSZ) {
|
|
cp += n;
|
|
continue;
|
|
}
|
|
if (type == T_AAAA && n != IN6ADDRSZ) {
|
|
cp += n;
|
|
continue;
|
|
}
|
|
if (type == T_AAAA) {
|
|
struct in6_addr in6;
|
|
memcpy(&in6, cp, IN6ADDRSZ);
|
|
if (IN6_IS_ADDR_V4MAPPED(&in6)) {
|
|
cp += n;
|
|
continue;
|
|
}
|
|
}
|
|
if (!haveanswer) {
|
|
int nn;
|
|
|
|
canonname = bp;
|
|
nn = strlen(bp) + 1; /* for the \0 */
|
|
bp += nn;
|
|
}
|
|
|
|
/* don't overwrite pai */
|
|
ai = *pai;
|
|
ai.ai_family = (type == T_A) ? AF_INET : AF_INET6;
|
|
afd = find_afd(ai.ai_family);
|
|
if (afd == NULL) {
|
|
cp += n;
|
|
continue;
|
|
}
|
|
cur->ai_next = get_ai(&ai, afd, (const char *)cp);
|
|
if (cur->ai_next == NULL)
|
|
had_error++;
|
|
while (cur && cur->ai_next)
|
|
cur = cur->ai_next;
|
|
cp += n;
|
|
break;
|
|
default:
|
|
abort();
|
|
}
|
|
if (!had_error)
|
|
haveanswer++;
|
|
}
|
|
if (haveanswer) {
|
|
if (!canonname)
|
|
(void)get_canonname(pai, sentinel.ai_next, qname);
|
|
else
|
|
(void)get_canonname(pai, sentinel.ai_next, canonname);
|
|
h_errno = NETDB_SUCCESS;
|
|
return sentinel.ai_next;
|
|
}
|
|
|
|
h_errno = NO_RECOVERY;
|
|
return NULL;
|
|
}
|
|
|
|
struct addrinfo_sort_elem {
|
|
struct addrinfo *ai;
|
|
int has_src_addr;
|
|
sockaddr_union src_addr;
|
|
int original_order;
|
|
};
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_get_scope(const struct sockaddr *addr)
|
|
{
|
|
if (addr->sa_family == AF_INET6) {
|
|
const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr;
|
|
if (IN6_IS_ADDR_MULTICAST(&addr6->sin6_addr)) {
|
|
return IPV6_ADDR_MC_SCOPE(&addr6->sin6_addr);
|
|
} else if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr) ||
|
|
IN6_IS_ADDR_LINKLOCAL(&addr6->sin6_addr)) {
|
|
/*
|
|
* RFC 4291 section 2.5.3 says loopback is to be treated as having
|
|
* link-local scope.
|
|
*/
|
|
return IPV6_ADDR_SCOPE_LINKLOCAL;
|
|
} else if (IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr)) {
|
|
return IPV6_ADDR_SCOPE_SITELOCAL;
|
|
} else {
|
|
return IPV6_ADDR_SCOPE_GLOBAL;
|
|
}
|
|
} else if (addr->sa_family == AF_INET) {
|
|
const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;
|
|
unsigned long int na = ntohl(addr4->sin_addr.s_addr);
|
|
|
|
if (IN_LOOPBACK(na) || /* 127.0.0.0/8 */
|
|
(na & 0xffff0000) == 0xa9fe0000) { /* 169.254.0.0/16 */
|
|
return IPV6_ADDR_SCOPE_LINKLOCAL;
|
|
} else {
|
|
/*
|
|
* According to draft-ietf-6man-rfc3484-revise-01 section 2.3,
|
|
* it is best not to treat the private IPv4 ranges
|
|
* (10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16) as being
|
|
* in a special scope, so we don't.
|
|
*/
|
|
return IPV6_ADDR_SCOPE_GLOBAL;
|
|
}
|
|
} else {
|
|
/*
|
|
* This should never happen.
|
|
* Return a scope with low priority as a last resort.
|
|
*/
|
|
return IPV6_ADDR_SCOPE_NODELOCAL;
|
|
}
|
|
}
|
|
|
|
/* These macros are modelled after the ones in <netinet/in6.h>. */
|
|
|
|
/* RFC 4380, section 2.6 */
|
|
#define IN6_IS_ADDR_TEREDO(a) \
|
|
((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == ntohl(0x20010000)))
|
|
|
|
/* RFC 3056, section 2. */
|
|
#define IN6_IS_ADDR_6TO4(a) \
|
|
(((a)->s6_addr[0] == 0x20) && ((a)->s6_addr[1] == 0x02))
|
|
|
|
/*
|
|
* Get the label for a given IPv4/IPv6 address.
|
|
* RFC 3484, section 2.1, plus Teredo added in with label 5.
|
|
*/
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_get_label(const struct sockaddr *addr)
|
|
{
|
|
if (addr->sa_family == AF_INET) {
|
|
return 4;
|
|
} else if (addr->sa_family == AF_INET6) {
|
|
const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr;
|
|
if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr)) {
|
|
return 0;
|
|
} else if (IN6_IS_ADDR_V4COMPAT(&addr6->sin6_addr)) {
|
|
return 3;
|
|
} else if (IN6_IS_ADDR_TEREDO(&addr6->sin6_addr)) {
|
|
return 5;
|
|
} else if (IN6_IS_ADDR_6TO4(&addr6->sin6_addr)) {
|
|
return 2;
|
|
} else {
|
|
return 1;
|
|
}
|
|
} else {
|
|
/*
|
|
* This should never happen.
|
|
* Return a semi-random label as a last resort.
|
|
*/
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Get the precedence for a given IPv4/IPv6 address.
|
|
* RFC 3484, section 2.1, plus Teredo added in with precedence 25.
|
|
*/
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_get_precedence(const struct sockaddr *addr)
|
|
{
|
|
if (addr->sa_family == AF_INET) {
|
|
return 10;
|
|
} else if (addr->sa_family == AF_INET6) {
|
|
const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr;
|
|
if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr)) {
|
|
return 50;
|
|
} else if (IN6_IS_ADDR_V4COMPAT(&addr6->sin6_addr)) {
|
|
return 20;
|
|
} else if (IN6_IS_ADDR_TEREDO(&addr6->sin6_addr)) {
|
|
return 25;
|
|
} else if (IN6_IS_ADDR_6TO4(&addr6->sin6_addr)) {
|
|
return 30;
|
|
} else {
|
|
return 40;
|
|
}
|
|
} else {
|
|
return 5;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Find number of matching initial bits between the two addresses a1 and a2.
|
|
*/
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_common_prefix_len(const struct in6_addr *a1, const struct in6_addr *a2)
|
|
{
|
|
const char *p1 = (const char *)a1;
|
|
const char *p2 = (const char *)a2;
|
|
unsigned i;
|
|
|
|
for (i = 0; i < sizeof(*a1); ++i) {
|
|
int x, j;
|
|
|
|
if (p1[i] == p2[i]) {
|
|
continue;
|
|
}
|
|
x = p1[i] ^ p2[i];
|
|
for (j = 0; j < CHAR_BIT; ++j) {
|
|
if (x & (1 << (CHAR_BIT - 1))) {
|
|
return i * CHAR_BIT + j;
|
|
}
|
|
x <<= 1;
|
|
}
|
|
}
|
|
return sizeof(*a1) * CHAR_BIT;
|
|
}
|
|
|
|
/*
|
|
* Compare two source/destination address pairs.
|
|
* RFC 3484, section 6.
|
|
*/
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_rfc3484_compare(const void *ptr1, const void* ptr2)
|
|
{
|
|
const struct addrinfo_sort_elem *a1 = (const struct addrinfo_sort_elem *)ptr1;
|
|
const struct addrinfo_sort_elem *a2 = (const struct addrinfo_sort_elem *)ptr2;
|
|
int scope_src1, scope_dst1, scope_match1;
|
|
int scope_src2, scope_dst2, scope_match2;
|
|
int label_src1, label_dst1, label_match1;
|
|
int label_src2, label_dst2, label_match2;
|
|
int precedence1, precedence2;
|
|
int prefixlen1, prefixlen2;
|
|
|
|
/* Rule 1: Avoid unusable destinations. */
|
|
if (a1->has_src_addr != a2->has_src_addr) {
|
|
return a2->has_src_addr - a1->has_src_addr;
|
|
}
|
|
|
|
/* Rule 2: Prefer matching scope. */
|
|
scope_src1 = _get_scope(&a1->src_addr.generic);
|
|
scope_dst1 = _get_scope(a1->ai->ai_addr);
|
|
scope_match1 = (scope_src1 == scope_dst1);
|
|
|
|
scope_src2 = _get_scope(&a2->src_addr.generic);
|
|
scope_dst2 = _get_scope(a2->ai->ai_addr);
|
|
scope_match2 = (scope_src2 == scope_dst2);
|
|
|
|
if (scope_match1 != scope_match2) {
|
|
return scope_match2 - scope_match1;
|
|
}
|
|
|
|
/*
|
|
* Rule 3: Avoid deprecated addresses.
|
|
* TODO(sesse): We don't currently have a good way of finding this.
|
|
*/
|
|
|
|
/*
|
|
* Rule 4: Prefer home addresses.
|
|
* TODO(sesse): We don't currently have a good way of finding this.
|
|
*/
|
|
|
|
/* Rule 5: Prefer matching label. */
|
|
label_src1 = _get_label(&a1->src_addr.generic);
|
|
label_dst1 = _get_label(a1->ai->ai_addr);
|
|
label_match1 = (label_src1 == label_dst1);
|
|
|
|
label_src2 = _get_label(&a2->src_addr.generic);
|
|
label_dst2 = _get_label(a2->ai->ai_addr);
|
|
label_match2 = (label_src2 == label_dst2);
|
|
|
|
if (label_match1 != label_match2) {
|
|
return label_match2 - label_match1;
|
|
}
|
|
|
|
/* Rule 6: Prefer higher precedence. */
|
|
precedence1 = _get_precedence(a1->ai->ai_addr);
|
|
precedence2 = _get_precedence(a2->ai->ai_addr);
|
|
if (precedence1 != precedence2) {
|
|
return precedence2 - precedence1;
|
|
}
|
|
|
|
/*
|
|
* Rule 7: Prefer native transport.
|
|
* TODO(sesse): We don't currently have a good way of finding this.
|
|
*/
|
|
|
|
/* Rule 8: Prefer smaller scope. */
|
|
if (scope_dst1 != scope_dst2) {
|
|
return scope_dst1 - scope_dst2;
|
|
}
|
|
|
|
/*
|
|
* Rule 9: Use longest matching prefix.
|
|
* We implement this for IPv6 only, as the rules in RFC 3484 don't seem
|
|
* to work very well directly applied to IPv4. (glibc uses information from
|
|
* the routing table for a custom IPv4 implementation here.)
|
|
*/
|
|
if (a1->has_src_addr && a1->ai->ai_addr->sa_family == AF_INET6 &&
|
|
a2->has_src_addr && a2->ai->ai_addr->sa_family == AF_INET6) {
|
|
const struct sockaddr_in6 *a1_src = &a1->src_addr.in6;
|
|
const struct sockaddr_in6 *a1_dst = (const struct sockaddr_in6 *)a1->ai->ai_addr;
|
|
const struct sockaddr_in6 *a2_src = &a2->src_addr.in6;
|
|
const struct sockaddr_in6 *a2_dst = (const struct sockaddr_in6 *)a2->ai->ai_addr;
|
|
prefixlen1 = _common_prefix_len(&a1_src->sin6_addr, &a1_dst->sin6_addr);
|
|
prefixlen2 = _common_prefix_len(&a2_src->sin6_addr, &a2_dst->sin6_addr);
|
|
if (prefixlen1 != prefixlen2) {
|
|
return prefixlen2 - prefixlen1;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Rule 10: Leave the order unchanged.
|
|
* We need this since qsort() is not necessarily stable.
|
|
*/
|
|
return a1->original_order - a2->original_order;
|
|
}
|
|
|
|
/*
|
|
* Find the source address that will be used if trying to connect to the given
|
|
* address. src_addr must be large enough to hold a struct sockaddr_in6.
|
|
*
|
|
* Returns 1 if a source address was found, 0 if the address is unreachable,
|
|
* and -1 if a fatal error occurred. If 0 or 1, the contents of src_addr are
|
|
* undefined.
|
|
*/
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_find_src_addr(const struct sockaddr *addr, struct sockaddr *src_addr)
|
|
{
|
|
int sock;
|
|
int ret;
|
|
socklen_t len;
|
|
|
|
switch (addr->sa_family) {
|
|
case AF_INET:
|
|
len = sizeof(struct sockaddr_in);
|
|
break;
|
|
case AF_INET6:
|
|
len = sizeof(struct sockaddr_in6);
|
|
break;
|
|
default:
|
|
/* No known usable source address for non-INET families. */
|
|
return 0;
|
|
}
|
|
|
|
sock = socket(addr->sa_family, SOCK_DGRAM, IPPROTO_UDP);
|
|
if (sock == -1) {
|
|
if (errno == EAFNOSUPPORT) {
|
|
return 0;
|
|
} else {
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
do {
|
|
ret = connect(sock, addr, len);
|
|
} while (ret == -1 && errno == EINTR);
|
|
|
|
if (ret == -1) {
|
|
close(sock);
|
|
return 0;
|
|
}
|
|
|
|
if (getsockname(sock, src_addr, &len) == -1) {
|
|
close(sock);
|
|
return -1;
|
|
}
|
|
close(sock);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Sort the linked list starting at sentinel->ai_next in RFC3484 order.
|
|
* Will leave the list unchanged if an error occurs.
|
|
*/
|
|
|
|
/*ARGSUSED*/
|
|
static void
|
|
_rfc3484_sort(struct addrinfo *list_sentinel)
|
|
{
|
|
struct addrinfo *cur;
|
|
int nelem = 0, i;
|
|
struct addrinfo_sort_elem *elems;
|
|
|
|
cur = list_sentinel->ai_next;
|
|
while (cur) {
|
|
++nelem;
|
|
cur = cur->ai_next;
|
|
}
|
|
|
|
elems = (struct addrinfo_sort_elem *)malloc(nelem * sizeof(struct addrinfo_sort_elem));
|
|
if (elems == NULL) {
|
|
goto error;
|
|
}
|
|
|
|
/*
|
|
* Convert the linked list to an array that also contains the candidate
|
|
* source address for each destination address.
|
|
*/
|
|
for (i = 0, cur = list_sentinel->ai_next; i < nelem; ++i, cur = cur->ai_next) {
|
|
int has_src_addr;
|
|
assert(cur != NULL);
|
|
elems[i].ai = cur;
|
|
elems[i].original_order = i;
|
|
|
|
has_src_addr = _find_src_addr(cur->ai_addr, &elems[i].src_addr.generic);
|
|
if (has_src_addr == -1) {
|
|
goto error;
|
|
}
|
|
elems[i].has_src_addr = has_src_addr;
|
|
}
|
|
|
|
/* Sort the addresses, and rearrange the linked list so it matches the sorted order. */
|
|
qsort((void *)elems, nelem, sizeof(struct addrinfo_sort_elem), _rfc3484_compare);
|
|
|
|
list_sentinel->ai_next = elems[0].ai;
|
|
for (i = 0; i < nelem - 1; ++i) {
|
|
elems[i].ai->ai_next = elems[i + 1].ai;
|
|
}
|
|
elems[nelem - 1].ai->ai_next = NULL;
|
|
|
|
error:
|
|
free(elems);
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
|
|
{
|
|
struct addrinfo *ai;
|
|
querybuf *buf, *buf2;
|
|
const char *name;
|
|
const struct addrinfo *pai;
|
|
struct addrinfo sentinel, *cur;
|
|
struct res_target q, q2;
|
|
res_state res;
|
|
|
|
name = va_arg(ap, char *);
|
|
pai = va_arg(ap, const struct addrinfo *);
|
|
//fprintf(stderr, "_dns_getaddrinfo() name = '%s'\n", name);
|
|
|
|
memset(&q, 0, sizeof(q));
|
|
memset(&q2, 0, sizeof(q2));
|
|
memset(&sentinel, 0, sizeof(sentinel));
|
|
cur = &sentinel;
|
|
|
|
buf = malloc(sizeof(*buf));
|
|
if (buf == NULL) {
|
|
h_errno = NETDB_INTERNAL;
|
|
return NS_NOTFOUND;
|
|
}
|
|
buf2 = malloc(sizeof(*buf2));
|
|
if (buf2 == NULL) {
|
|
free(buf);
|
|
h_errno = NETDB_INTERNAL;
|
|
return NS_NOTFOUND;
|
|
}
|
|
|
|
switch (pai->ai_family) {
|
|
case AF_UNSPEC:
|
|
/* prefer IPv6 */
|
|
q.name = name;
|
|
q.qclass = C_IN;
|
|
q.answer = buf->buf;
|
|
q.anslen = sizeof(buf->buf);
|
|
/* If AI_ADDRCONFIG, lookup IPv6 only if we have connectivity */
|
|
if (!(pai->ai_flags & AI_ADDRCONFIG) || _have_ipv6()) {
|
|
q.qtype = T_AAAA;
|
|
q.next = &q2;
|
|
q2.name = name;
|
|
q2.qclass = C_IN;
|
|
q2.qtype = T_A;
|
|
q2.answer = buf2->buf;
|
|
q2.anslen = sizeof(buf2->buf);
|
|
} else {
|
|
q.qtype = T_A;
|
|
}
|
|
break;
|
|
case AF_INET:
|
|
q.name = name;
|
|
q.qclass = C_IN;
|
|
q.qtype = T_A;
|
|
q.answer = buf->buf;
|
|
q.anslen = sizeof(buf->buf);
|
|
break;
|
|
case AF_INET6:
|
|
q.name = name;
|
|
q.qclass = C_IN;
|
|
q.qtype = T_AAAA;
|
|
q.answer = buf->buf;
|
|
q.anslen = sizeof(buf->buf);
|
|
break;
|
|
default:
|
|
free(buf);
|
|
free(buf2);
|
|
return NS_UNAVAIL;
|
|
}
|
|
|
|
res = __res_get_state();
|
|
if (res == NULL) {
|
|
free(buf);
|
|
free(buf2);
|
|
return NS_NOTFOUND;
|
|
}
|
|
|
|
if (res_searchN(name, &q, res) < 0) {
|
|
__res_put_state(res);
|
|
free(buf);
|
|
free(buf2);
|
|
return NS_NOTFOUND;
|
|
}
|
|
ai = getanswer(buf, q.n, q.name, q.qtype, pai);
|
|
if (ai) {
|
|
cur->ai_next = ai;
|
|
while (cur && cur->ai_next)
|
|
cur = cur->ai_next;
|
|
}
|
|
if (q.next) {
|
|
ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai);
|
|
if (ai)
|
|
cur->ai_next = ai;
|
|
}
|
|
free(buf);
|
|
free(buf2);
|
|
if (sentinel.ai_next == NULL) {
|
|
__res_put_state(res);
|
|
switch (h_errno) {
|
|
case HOST_NOT_FOUND:
|
|
return NS_NOTFOUND;
|
|
case TRY_AGAIN:
|
|
return NS_TRYAGAIN;
|
|
default:
|
|
return NS_UNAVAIL;
|
|
}
|
|
}
|
|
|
|
_rfc3484_sort(&sentinel);
|
|
|
|
__res_put_state(res);
|
|
|
|
*((struct addrinfo **)rv) = sentinel.ai_next;
|
|
return NS_SUCCESS;
|
|
}
|
|
|
|
static void
|
|
_sethtent(FILE **hostf)
|
|
{
|
|
|
|
if (!*hostf)
|
|
*hostf = fopen(_PATH_HOSTS, "r" );
|
|
else
|
|
rewind(*hostf);
|
|
}
|
|
|
|
static void
|
|
_endhtent(FILE **hostf)
|
|
{
|
|
|
|
if (*hostf) {
|
|
(void) fclose(*hostf);
|
|
*hostf = NULL;
|
|
}
|
|
}
|
|
|
|
static struct addrinfo *
|
|
_gethtent(FILE **hostf, const char *name, const struct addrinfo *pai)
|
|
{
|
|
char *p;
|
|
char *cp, *tname, *cname;
|
|
struct addrinfo hints, *res0, *res;
|
|
int error;
|
|
const char *addr;
|
|
char hostbuf[8*1024];
|
|
|
|
// fprintf(stderr, "_gethtent() name = '%s'\n", name);
|
|
assert(name != NULL);
|
|
assert(pai != NULL);
|
|
|
|
if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "r" )))
|
|
return (NULL);
|
|
again:
|
|
if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf)))
|
|
return (NULL);
|
|
if (*p == '#')
|
|
goto again;
|
|
if (!(cp = strpbrk(p, "#\n")))
|
|
goto again;
|
|
*cp = '\0';
|
|
if (!(cp = strpbrk(p, " \t")))
|
|
goto again;
|
|
*cp++ = '\0';
|
|
addr = p;
|
|
/* if this is not something we're looking for, skip it. */
|
|
cname = NULL;
|
|
while (cp && *cp) {
|
|
if (*cp == ' ' || *cp == '\t') {
|
|
cp++;
|
|
continue;
|
|
}
|
|
if (!cname)
|
|
cname = cp;
|
|
tname = cp;
|
|
if ((cp = strpbrk(cp, " \t")) != NULL)
|
|
*cp++ = '\0';
|
|
// fprintf(stderr, "\ttname = '%s'", tname);
|
|
if (strcasecmp(name, tname) == 0)
|
|
goto found;
|
|
}
|
|
goto again;
|
|
|
|
found:
|
|
hints = *pai;
|
|
hints.ai_flags = AI_NUMERICHOST;
|
|
error = getaddrinfo(addr, NULL, &hints, &res0);
|
|
if (error)
|
|
goto again;
|
|
for (res = res0; res; res = res->ai_next) {
|
|
/* cover it up */
|
|
res->ai_flags = pai->ai_flags;
|
|
|
|
if (pai->ai_flags & AI_CANONNAME) {
|
|
if (get_canonname(pai, res, cname) != 0) {
|
|
freeaddrinfo(res0);
|
|
goto again;
|
|
}
|
|
}
|
|
}
|
|
return res0;
|
|
}
|
|
|
|
/*ARGSUSED*/
|
|
static int
|
|
_files_getaddrinfo(void *rv, void *cb_data, va_list ap)
|
|
{
|
|
const char *name;
|
|
const struct addrinfo *pai;
|
|
struct addrinfo sentinel, *cur;
|
|
struct addrinfo *p;
|
|
FILE *hostf = NULL;
|
|
|
|
name = va_arg(ap, char *);
|
|
pai = va_arg(ap, struct addrinfo *);
|
|
|
|
// fprintf(stderr, "_files_getaddrinfo() name = '%s'\n", name);
|
|
memset(&sentinel, 0, sizeof(sentinel));
|
|
cur = &sentinel;
|
|
|
|
_sethtent(&hostf);
|
|
while ((p = _gethtent(&hostf, name, pai)) != NULL) {
|
|
cur->ai_next = p;
|
|
while (cur && cur->ai_next)
|
|
cur = cur->ai_next;
|
|
}
|
|
_endhtent(&hostf);
|
|
|
|
*((struct addrinfo **)rv) = sentinel.ai_next;
|
|
if (sentinel.ai_next == NULL)
|
|
return NS_NOTFOUND;
|
|
return NS_SUCCESS;
|
|
}
|
|
|
|
/* resolver logic */
|
|
|
|
/*
|
|
* Formulate a normal query, send, and await answer.
|
|
* Returned answer is placed in supplied buffer "answer".
|
|
* Perform preliminary check of answer, returning success only
|
|
* if no error is indicated and the answer count is nonzero.
|
|
* Return the size of the response on success, -1 on error.
|
|
* Error number is left in h_errno.
|
|
*
|
|
* Caller must parse answer and determine whether it answers the question.
|
|
*/
|
|
static int
|
|
res_queryN(const char *name, /* domain name */ struct res_target *target,
|
|
res_state res)
|
|
{
|
|
u_char buf[MAXPACKET];
|
|
HEADER *hp;
|
|
int n;
|
|
struct res_target *t;
|
|
int rcode;
|
|
int ancount;
|
|
|
|
assert(name != NULL);
|
|
/* XXX: target may be NULL??? */
|
|
|
|
rcode = NOERROR;
|
|
ancount = 0;
|
|
|
|
for (t = target; t; t = t->next) {
|
|
int class, type;
|
|
u_char *answer;
|
|
int anslen;
|
|
|
|
hp = (HEADER *)(void *)t->answer;
|
|
hp->rcode = NOERROR; /* default */
|
|
|
|
/* make it easier... */
|
|
class = t->qclass;
|
|
type = t->qtype;
|
|
answer = t->answer;
|
|
anslen = t->anslen;
|
|
#ifdef DEBUG
|
|
if (res->options & RES_DEBUG)
|
|
printf(";; res_nquery(%s, %d, %d)\n", name, class, type);
|
|
#endif
|
|
|
|
n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL,
|
|
buf, sizeof(buf));
|
|
#ifdef RES_USE_EDNS0
|
|
if (n > 0 && (res->options & RES_USE_EDNS0) != 0)
|
|
n = res_nopt(res, n, buf, sizeof(buf), anslen);
|
|
#endif
|
|
if (n <= 0) {
|
|
#ifdef DEBUG
|
|
if (res->options & RES_DEBUG)
|
|
printf(";; res_nquery: mkquery failed\n");
|
|
#endif
|
|
h_errno = NO_RECOVERY;
|
|
return n;
|
|
}
|
|
n = res_nsend(res, buf, n, answer, anslen);
|
|
#if 0
|
|
if (n < 0) {
|
|
#ifdef DEBUG
|
|
if (res->options & RES_DEBUG)
|
|
printf(";; res_query: send error\n");
|
|
#endif
|
|
h_errno = TRY_AGAIN;
|
|
return n;
|
|
}
|
|
#endif
|
|
|
|
if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) {
|
|
rcode = hp->rcode; /* record most recent error */
|
|
#ifdef DEBUG
|
|
if (res->options & RES_DEBUG)
|
|
printf(";; rcode = %u, ancount=%u\n", hp->rcode,
|
|
ntohs(hp->ancount));
|
|
#endif
|
|
continue;
|
|
}
|
|
|
|
ancount += ntohs(hp->ancount);
|
|
|
|
t->n = n;
|
|
}
|
|
|
|
if (ancount == 0) {
|
|
switch (rcode) {
|
|
case NXDOMAIN:
|
|
h_errno = HOST_NOT_FOUND;
|
|
break;
|
|
case SERVFAIL:
|
|
h_errno = TRY_AGAIN;
|
|
break;
|
|
case NOERROR:
|
|
h_errno = NO_DATA;
|
|
break;
|
|
case FORMERR:
|
|
case NOTIMP:
|
|
case REFUSED:
|
|
default:
|
|
h_errno = NO_RECOVERY;
|
|
break;
|
|
}
|
|
return -1;
|
|
}
|
|
return ancount;
|
|
}
|
|
|
|
/*
|
|
* Formulate a normal query, send, and retrieve answer in supplied buffer.
|
|
* Return the size of the response on success, -1 on error.
|
|
* If enabled, implement search rules until answer or unrecoverable failure
|
|
* is detected. Error code, if any, is left in h_errno.
|
|
*/
|
|
static int
|
|
res_searchN(const char *name, struct res_target *target, res_state res)
|
|
{
|
|
const char *cp, * const *domain;
|
|
HEADER *hp;
|
|
u_int dots;
|
|
int trailing_dot, ret, saved_herrno;
|
|
int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
|
|
|
|
assert(name != NULL);
|
|
assert(target != NULL);
|
|
|
|
hp = (HEADER *)(void *)target->answer; /*XXX*/
|
|
|
|
errno = 0;
|
|
h_errno = HOST_NOT_FOUND; /* default, if we never query */
|
|
dots = 0;
|
|
for (cp = name; *cp; cp++)
|
|
dots += (*cp == '.');
|
|
trailing_dot = 0;
|
|
if (cp > name && *--cp == '.')
|
|
trailing_dot++;
|
|
|
|
|
|
//fprintf(stderr, "res_searchN() name = '%s'\n", name);
|
|
|
|
/*
|
|
* if there aren't any dots, it could be a user-level alias
|
|
*/
|
|
if (!dots && (cp = __hostalias(name)) != NULL) {
|
|
ret = res_queryN(cp, target, res);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* If there are dots in the name already, let's just give it a try
|
|
* 'as is'. The threshold can be set with the "ndots" option.
|
|
*/
|
|
saved_herrno = -1;
|
|
if (dots >= res->ndots) {
|
|
ret = res_querydomainN(name, NULL, target, res);
|
|
if (ret > 0)
|
|
return (ret);
|
|
saved_herrno = h_errno;
|
|
tried_as_is++;
|
|
}
|
|
|
|
/*
|
|
* We do at least one level of search if
|
|
* - there is no dot and RES_DEFNAME is set, or
|
|
* - there is at least one dot, there is no trailing dot,
|
|
* and RES_DNSRCH is set.
|
|
*/
|
|
if ((!dots && (res->options & RES_DEFNAMES)) ||
|
|
(dots && !trailing_dot && (res->options & RES_DNSRCH))) {
|
|
int done = 0;
|
|
|
|
for (domain = (const char * const *)res->dnsrch;
|
|
*domain && !done;
|
|
domain++) {
|
|
|
|
ret = res_querydomainN(name, *domain, target, res);
|
|
if (ret > 0)
|
|
return ret;
|
|
|
|
/*
|
|
* If no server present, give up.
|
|
* If name isn't found in this domain,
|
|
* keep trying higher domains in the search list
|
|
* (if that's enabled).
|
|
* On a NO_DATA error, keep trying, otherwise
|
|
* a wildcard entry of another type could keep us
|
|
* from finding this entry higher in the domain.
|
|
* If we get some other error (negative answer or
|
|
* server failure), then stop searching up,
|
|
* but try the input name below in case it's
|
|
* fully-qualified.
|
|
*/
|
|
if (errno == ECONNREFUSED) {
|
|
h_errno = TRY_AGAIN;
|
|
return -1;
|
|
}
|
|
|
|
switch (h_errno) {
|
|
case NO_DATA:
|
|
got_nodata++;
|
|
/* FALLTHROUGH */
|
|
case HOST_NOT_FOUND:
|
|
/* keep trying */
|
|
break;
|
|
case TRY_AGAIN:
|
|
if (hp->rcode == SERVFAIL) {
|
|
/* try next search element, if any */
|
|
got_servfail++;
|
|
break;
|
|
}
|
|
/* FALLTHROUGH */
|
|
default:
|
|
/* anything else implies that we're done */
|
|
done++;
|
|
}
|
|
/*
|
|
* if we got here for some reason other than DNSRCH,
|
|
* we only wanted one iteration of the loop, so stop.
|
|
*/
|
|
if (!(res->options & RES_DNSRCH))
|
|
done++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* if we have not already tried the name "as is", do that now.
|
|
* note that we do this regardless of how many dots were in the
|
|
* name or whether it ends with a dot.
|
|
*/
|
|
if (!tried_as_is) {
|
|
ret = res_querydomainN(name, NULL, target, res);
|
|
if (ret > 0)
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* if we got here, we didn't satisfy the search.
|
|
* if we did an initial full query, return that query's h_errno
|
|
* (note that we wouldn't be here if that query had succeeded).
|
|
* else if we ever got a nodata, send that back as the reason.
|
|
* else send back meaningless h_errno, that being the one from
|
|
* the last DNSRCH we did.
|
|
*/
|
|
if (saved_herrno != -1)
|
|
h_errno = saved_herrno;
|
|
else if (got_nodata)
|
|
h_errno = NO_DATA;
|
|
else if (got_servfail)
|
|
h_errno = TRY_AGAIN;
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Perform a call on res_query on the concatenation of name and domain,
|
|
* removing a trailing dot from name if domain is NULL.
|
|
*/
|
|
static int
|
|
res_querydomainN(const char *name, const char *domain,
|
|
struct res_target *target, res_state res)
|
|
{
|
|
char nbuf[MAXDNAME];
|
|
const char *longname = nbuf;
|
|
size_t n, d;
|
|
|
|
assert(name != NULL);
|
|
/* XXX: target may be NULL??? */
|
|
|
|
#ifdef DEBUG
|
|
if (res->options & RES_DEBUG)
|
|
printf(";; res_querydomain(%s, %s)\n",
|
|
name, domain?domain:"<Nil>");
|
|
#endif
|
|
if (domain == NULL) {
|
|
/*
|
|
* Check for trailing '.';
|
|
* copy without '.' if present.
|
|
*/
|
|
n = strlen(name);
|
|
if (n + 1 > sizeof(nbuf)) {
|
|
h_errno = NO_RECOVERY;
|
|
return -1;
|
|
}
|
|
if (n > 0 && name[--n] == '.') {
|
|
strncpy(nbuf, name, n);
|
|
nbuf[n] = '\0';
|
|
} else
|
|
longname = name;
|
|
} else {
|
|
n = strlen(name);
|
|
d = strlen(domain);
|
|
if (n + 1 + d + 1 > sizeof(nbuf)) {
|
|
h_errno = NO_RECOVERY;
|
|
return -1;
|
|
}
|
|
snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
|
|
}
|
|
return res_queryN(longname, target, res);
|
|
}
|