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NetBSD/lib/libc/net/getaddrinfo.c

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/* $NetBSD: getaddrinfo.c,v 1.119 2018/12/13 04:41:41 dholland Exp $ */
/* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* 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 project 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 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.
*/
/*
* Issues to be discussed:
* - 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.
* current code - SEGV on freeaddrinfo(NULL)
* Note:
* - 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?
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: getaddrinfo.c,v 1.119 2018/12/13 04:41:41 dholland Exp $");
#endif /* LIBC_SCCS and not lint */
#ifndef RUMP_ACTION
#include "namespace.h"
#endif
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ifaddrs.h>
#include <syslog.h>
#include <stdarg.h>
#include <nsswitch.h>
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#endif
#include "servent.h"
#ifndef RUMP_ACTION
#ifdef __weak_alias
__weak_alias(getaddrinfo,_getaddrinfo)
__weak_alias(allocaddrinfo,_allocaddrinfo)
__weak_alias(freeaddrinfo,_freeaddrinfo)
__weak_alias(gai_strerror,_gai_strerror)
#endif
#endif
#define SUCCESS 0
#define ANY 0
#define YES 1
#define NO 0
#define sa4addr(sa) ((void *)&((struct sockaddr_in *)(void *)sa)->sin_addr)
#define sa6addr(sa) ((void *)&((struct sockaddr_in6 *)(void *)sa)->sin6_addr)
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
struct policyqueue {
TAILQ_ENTRY(policyqueue) pc_entry;
#ifdef INET6
struct in6_addrpolicy pc_policy;
#endif
};
TAILQ_HEAD(policyhead, policyqueue);
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
#define AIO_SRCFLAG_DEPRECATED 0x1
struct ai_order {
union {
struct sockaddr_storage aiou_ss;
struct sockaddr aiou_sa;
} aio_src_un;
#define aio_srcsa aio_src_un.aiou_sa
u_int32_t aio_srcflag;
int aio_srcscope;
int aio_dstscope;
struct policyqueue *aio_srcpolicy;
struct policyqueue *aio_dstpolicy;
struct addrinfo *aio_ai;
int aio_matchlen;
};
static const ns_src default_dns_files[] = {
{ NSSRC_FILES, NS_SUCCESS },
{ NSSRC_DNS, NS_SUCCESS },
{ 0, 0 }
};
#define MAXPACKET (64*1024)
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 */
};
struct srvinfo {
struct srvinfo *next;
char name[MAXDNAME];
int port, pri, weight;
};
static int gai_srvok(const char *);
static int str2number(const char *);
static int explore_fqdn(const struct addrinfo *, const char *,
const char *, struct addrinfo **, struct servent_data *);
static int explore_null(const struct addrinfo *,
const char *, struct addrinfo **, struct servent_data *);
static int explore_numeric(const struct addrinfo *, const char *,
const char *, struct addrinfo **, const char *, struct servent_data *);
static int explore_numeric_scope(const struct addrinfo *, const char *,
const char *, struct addrinfo **, struct servent_data *);
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 *,
struct servent_data *);
static int get_port(const struct addrinfo *, const char *, int,
struct servent_data *);
static const struct afd *find_afd(int);
static int addrconfig(uint64_t *);
static void set_source(struct ai_order *, struct policyhead *,
struct servent_data *);
static int comp_dst(const void *, const void *);
#ifdef INET6
static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *);
#endif
static int gai_addr2scopetype(struct sockaddr *);
static int reorder(struct addrinfo *, struct servent_data *);
static int get_addrselectpolicy(struct policyhead *);
static void free_addrselectpolicy(struct policyhead *);
static struct policyqueue *match_addrselectpolicy(struct sockaddr *,
struct policyhead *);
static int matchlen(struct sockaddr *, struct sockaddr *);
static struct addrinfo *getanswer(res_state, const querybuf *, int,
const char *, int, const struct addrinfo *);
static void aisort(struct addrinfo *s, res_state res);
static struct addrinfo * _dns_query(struct res_target *,
const struct addrinfo *, res_state, int);
static struct addrinfo * _dns_srv_lookup(const char *, const char *,
const struct addrinfo *);
static struct addrinfo * _dns_host_lookup(const char *,
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);
#ifdef YP
static struct addrinfo *_yphostent(char *, const struct addrinfo *);
static int _yp_getaddrinfo(void *, void *, va_list);
#endif
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 or servname not 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, svd) \
do { \
/* external reference: error and label free */ \
error = get_port((ai), (serv), 0, (svd)); \
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;
_DIAGASSERT(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);
}
/*
* We don't want localization to affect us
*/
#define PERIOD '.'
#define hyphenchar(c) ((c) == '-')
#define periodchar(c) ((c) == PERIOD)
#define underschar(c) ((c) == '_')
#define alphachar(c) (((c) >= 'a' && (c) <= 'z') || ((c) >= 'A' && (c) <= 'Z'))
#define digitchar(c) ((c) >= '0' && (c) <= '9')
#define firstchar(c) (alphachar(c) || digitchar(c) || underschar(c))
#define lastchar(c) (alphachar(c) || digitchar(c))
#define middlechar(c) (lastchar(c) || hyphenchar(c))
static int
gai_srvok(const char *dn)
{
int nch, pch, ch;
for (pch = PERIOD, nch = ch = *dn++; ch != '\0'; pch = ch, ch = nch) {
if (periodchar(ch))
continue;
if (periodchar(pch)) {
if (!firstchar(ch))
return 0;
} else if (periodchar(nch) || nch == '\0') {
if (!lastchar(ch))
return 0;
} else if (!middlechar(ch))
return 0;
}
return 1;
}
static in_port_t *
getport(struct addrinfo *ai) {
static in_port_t p;
switch (ai->ai_family) {
case AF_INET:
return &((struct sockaddr_in *)(void *)ai->ai_addr)->sin_port;
#ifdef INET6
case AF_INET6:
return &((struct sockaddr_in6 *)(void *)ai->ai_addr)->sin6_port;
#endif
default:
p = 0;
/* XXX: abort()? */
return &p;
}
}
static int
str2number(const char *p)
{
char *ep;
unsigned long v;
_DIAGASSERT(p != NULL);
if (*p == '\0')
return -1;
ep = NULL;
errno = 0;
v = strtoul(p, &ep, 10);
if (errno == 0 && ep && *ep == '\0' && v <= INT_MAX)
return (int)v;
else
return -1;
}
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;
struct servent_data svd;
uint64_t mask = (uint64_t)~0ULL;
int numeric = 0;
/* hostname is allowed to be NULL */
/* servname is allowed to be NULL */
/* hints is allowed to be NULL */
_DIAGASSERT(res != NULL);
(void)memset(&svd, 0, sizeof(svd));
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
memset(&ai, 0, sizeof(ai));
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);
}
}
}
}
if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && addrconfig(&mask) == -1)
ERR(EAI_FAIL);
/*
* 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, &svd);
if (error)
goto bad;
*pai = ai0;
}
ai0 = *pai;
/* NULL hostname, or numeric hostname */
for (ex = explore; ex->e_af >= 0; ex++) {
*pai = ai0;
/* ADDRCONFIG check */
if ((((uint64_t)1 << ex->e_af) & mask) == 0)
continue;
/* 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,
&svd);
else
error = explore_numeric_scope(pai, hostname, servname,
&cur->ai_next, &svd);
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) {
numeric = 1;
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;
/* ADDRCONFIG check */
/* PF_UNSPEC entries are prepared for DNS queries only */
if (ex->e_af != PF_UNSPEC &&
(((uint64_t)1 << ex->e_af) & mask) == 0)
continue;
/* 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,
&svd);
while (cur && cur->ai_next)
cur = cur->ai_next;
}
/* XXX */
if (sentinel.ai_next)
error = 0;
if (error)
goto free;
if (sentinel.ai_next) {
good:
/*
* If the returned entry is for an active connection,
* and the given name is not numeric, reorder the
* list, so that the application would try the list
* in the most efficient order. Since the head entry
* of the original list may contain ai_canonname and
* that entry may be moved elsewhere in the new list,
* we keep the pointer and will restore it in the new
* head entry. (Note that RFC3493 requires the head
* entry store it when requested by the caller).
*/
if (hints == NULL || !(hints->ai_flags & AI_PASSIVE)) {
if (!numeric) {
char *canonname;
canonname = sentinel.ai_next->ai_canonname;
sentinel.ai_next->ai_canonname = NULL;
(void)reorder(&sentinel, &svd);
if (sentinel.ai_next->ai_canonname == NULL) {
sentinel.ai_next->ai_canonname
= canonname;
} else if (canonname != NULL)
free(canonname);
}
}
endservent_r(&svd);
*res = sentinel.ai_next;
return SUCCESS;
} else
error = EAI_FAIL;
free:
bad:
endservent_r(&svd);
if (sentinel.ai_next)
freeaddrinfo(sentinel.ai_next);
*res = NULL;
return error;
}
static int
reorder(struct addrinfo *sentinel, struct servent_data *svd)
{
struct addrinfo *ai, **aip;
struct ai_order *aio;
int i, n;
struct policyhead policyhead;
/* count the number of addrinfo elements for sorting. */
for (n = 0, ai = sentinel->ai_next; ai != NULL; ai = ai->ai_next, n++)
;
/*
* If the number is small enough, we can skip the reordering process.
*/
if (n <= 1)
return n;
/* allocate a temporary array for sort and initialization of it. */
if ((aio = malloc(sizeof(*aio) * n)) == NULL)
return n; /* give up reordering */
memset(aio, 0, sizeof(*aio) * n);
/* retrieve address selection policy from the kernel */
TAILQ_INIT(&policyhead);
if (!get_addrselectpolicy(&policyhead)) {
/* no policy is installed into kernel, we don't sort. */
free(aio);
return n;
}
for (i = 0, ai = sentinel->ai_next; i < n; ai = ai->ai_next, i++) {
aio[i].aio_ai = ai;
aio[i].aio_dstscope = gai_addr2scopetype(ai->ai_addr);
aio[i].aio_dstpolicy = match_addrselectpolicy(ai->ai_addr,
&policyhead);
set_source(&aio[i], &policyhead, svd);
}
/* perform sorting. */
qsort(aio, n, sizeof(*aio), comp_dst);
/* reorder the addrinfo chain. */
for (i = 0, aip = &sentinel->ai_next; i < n; i++) {
*aip = aio[i].aio_ai;
aip = &aio[i].aio_ai->ai_next;
}
*aip = NULL;
/* cleanup and return */
free(aio);
free_addrselectpolicy(&policyhead);
return n;
}
static int
get_addrselectpolicy(struct policyhead *head)
{
#ifdef INET6
static const int mib[] = {
CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
static const u_int miblen = (u_int)__arraycount(mib);
size_t l;
char *buf;
struct in6_addrpolicy *pol, *ep;
if (sysctl(mib, miblen, NULL, &l, NULL, 0) < 0)
return 0;
if (l == 0)
return 0;
if ((buf = malloc(l)) == NULL)
return 0;
if (sysctl(mib, miblen, buf, &l, NULL, 0) < 0) {
free(buf);
return 0;
}
ep = (void *)(buf + l);
for (pol = (void *)buf; pol + 1 <= ep; pol++) {
struct policyqueue *new;
if ((new = malloc(sizeof(*new))) == NULL) {
free_addrselectpolicy(head); /* make the list empty */
break;
}
new->pc_policy = *pol;
TAILQ_INSERT_TAIL(head, new, pc_entry);
}
free(buf);
return 1;
#else
return 0;
#endif
}
static void
free_addrselectpolicy(struct policyhead *head)
{
struct policyqueue *ent, *nent;
for (ent = TAILQ_FIRST(head); ent; ent = nent) {
nent = TAILQ_NEXT(ent, pc_entry);
TAILQ_REMOVE(head, ent, pc_entry);
free(ent);
}
}
static struct policyqueue *
match_addrselectpolicy(struct sockaddr *addr, struct policyhead *head)
{
#ifdef INET6
struct policyqueue *ent, *bestent = NULL;
struct in6_addrpolicy *pol;
int curmatchlen, bestmatchlen = -1;
u_char *mp, *ep, *k, *p;
u_int m;
struct sockaddr_in6 key;
switch(addr->sa_family) {
case AF_INET6:
memcpy(&key, addr, sizeof(key));
break;
case AF_INET:
/* convert the address into IPv4-mapped IPv6 address. */
memset(&key, 0, sizeof(key));
key.sin6_family = AF_INET6;
key.sin6_len = sizeof(key);
key.sin6_addr.s6_addr[10] = 0xff;
key.sin6_addr.s6_addr[11] = 0xff;
memcpy(&key.sin6_addr.s6_addr[12], sa4addr(addr), 4);
break;
default:
return NULL;
}
for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) {
pol = &ent->pc_policy;
curmatchlen = 0;
mp = (void *)&pol->addrmask.sin6_addr;
ep = mp + 16; /* XXX: scope field? */
k = (void *)&key.sin6_addr;
p = (void *)&pol->addr.sin6_addr;
for (; mp < ep && *mp; mp++, k++, p++) {
m = *mp;
if ((*k & m) != *p)
goto next; /* not match */
if (m == 0xff) /* short cut for a typical case */
curmatchlen += 8;
else {
while (m >= 0x80) {
curmatchlen++;
m <<= 1;
}
}
}
/* matched. check if this is better than the current best. */
if (curmatchlen > bestmatchlen) {
bestent = ent;
bestmatchlen = curmatchlen;
}
next:
continue;
}
return bestent;
#else
return NULL;
#endif
}
static void
set_source(struct ai_order *aio, struct policyhead *ph,
struct servent_data *svd)
{
struct addrinfo ai = *aio->aio_ai;
struct sockaddr_storage ss;
socklen_t srclen;
int s;
/* set unspec ("no source is available"), just in case */
aio->aio_srcsa.sa_family = AF_UNSPEC;
aio->aio_srcscope = -1;
switch(ai.ai_family) {
case AF_INET:
#ifdef INET6
case AF_INET6:
#endif
break;
default: /* ignore unsupported AFs explicitly */
return;
}
/* XXX: make a dummy addrinfo to call connect() */
ai.ai_socktype = SOCK_DGRAM;
ai.ai_protocol = IPPROTO_UDP; /* is UDP too specific? */
ai.ai_next = NULL;
memset(&ss, 0, sizeof(ss));
memcpy(&ss, ai.ai_addr, ai.ai_addrlen);
ai.ai_addr = (void *)&ss;
get_port(&ai, "1", 0, svd);
/* open a socket to get the source address for the given dst */
if ((s = socket(ai.ai_family, ai.ai_socktype | SOCK_CLOEXEC,
ai.ai_protocol)) < 0)
return; /* give up */
if (connect(s, ai.ai_addr, ai.ai_addrlen) < 0)
goto cleanup;
srclen = ai.ai_addrlen;
if (getsockname(s, &aio->aio_srcsa, &srclen) < 0) {
aio->aio_srcsa.sa_family = AF_UNSPEC;
goto cleanup;
}
aio->aio_srcscope = gai_addr2scopetype(&aio->aio_srcsa);
aio->aio_srcpolicy = match_addrselectpolicy(&aio->aio_srcsa, ph);
aio->aio_matchlen = matchlen(&aio->aio_srcsa, aio->aio_ai->ai_addr);
#ifdef INET6
if (ai.ai_family == AF_INET6) {
struct in6_ifreq ifr6;
u_int32_t flags6;
memset(&ifr6, 0, sizeof(ifr6));
memcpy(&ifr6.ifr_addr, ai.ai_addr, ai.ai_addrlen);
if (ioctl(s, SIOCGIFAFLAG_IN6, &ifr6) == 0) {
flags6 = ifr6.ifr_ifru.ifru_flags6;
if ((flags6 & IN6_IFF_DEPRECATED))
aio->aio_srcflag |= AIO_SRCFLAG_DEPRECATED;
}
}
#endif
cleanup:
close(s);
return;
}
static int
matchlen(struct sockaddr *src, struct sockaddr *dst)
{
int match = 0;
u_char *s, *d;
u_char *lim;
u_int r, addrlen;
switch (src->sa_family) {
#ifdef INET6
case AF_INET6:
s = sa6addr(src);
d = sa6addr(dst);
addrlen = sizeof(struct in6_addr);
lim = s + addrlen;
break;
#endif
case AF_INET:
s = sa4addr(src);
d = sa4addr(dst);
addrlen = sizeof(struct in_addr);
lim = s + addrlen;
break;
default:
return 0;
}
while (s < lim)
if ((r = (*d++ ^ *s++)) != 0) {
while (r < addrlen * 8) {
match++;
r <<= 1;
}
break;
} else
match += 8;
return match;
}
static int
comp_dst(const void *arg1, const void *arg2)
{
const struct ai_order *dst1 = arg1, *dst2 = arg2;
/*
* Rule 1: Avoid unusable destinations.
* XXX: we currently do not consider if an appropriate route exists.
*/
if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
dst2->aio_srcsa.sa_family == AF_UNSPEC) {
return -1;
}
if (dst1->aio_srcsa.sa_family == AF_UNSPEC &&
dst2->aio_srcsa.sa_family != AF_UNSPEC) {
return 1;
}
/* Rule 2: Prefer matching scope. */
if (dst1->aio_dstscope == dst1->aio_srcscope &&
dst2->aio_dstscope != dst2->aio_srcscope) {
return -1;
}
if (dst1->aio_dstscope != dst1->aio_srcscope &&
dst2->aio_dstscope == dst2->aio_srcscope) {
return 1;
}
/* Rule 3: Avoid deprecated addresses. */
if (dst1->aio_srcsa.sa_family != AF_UNSPEC &&
dst2->aio_srcsa.sa_family != AF_UNSPEC) {
if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
return -1;
}
if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) &&
!(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) {
return 1;
}
}
/* Rule 4: Prefer home addresses. */
/* XXX: not implemented yet */
/* Rule 5: Prefer matching label. */
#ifdef INET6
if (dst1->aio_srcpolicy && dst1->aio_dstpolicy &&
dst1->aio_srcpolicy->pc_policy.label ==
dst1->aio_dstpolicy->pc_policy.label &&
(dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL ||
dst2->aio_srcpolicy->pc_policy.label !=
dst2->aio_dstpolicy->pc_policy.label)) {
return -1;
}
if (dst2->aio_srcpolicy && dst2->aio_dstpolicy &&
dst2->aio_srcpolicy->pc_policy.label ==
dst2->aio_dstpolicy->pc_policy.label &&
(dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL ||
dst1->aio_srcpolicy->pc_policy.label !=
dst1->aio_dstpolicy->pc_policy.label)) {
return 1;
}
#endif
/* Rule 6: Prefer higher precedence. */
#ifdef INET6
if (dst1->aio_dstpolicy &&
(dst2->aio_dstpolicy == NULL ||
dst1->aio_dstpolicy->pc_policy.preced >
dst2->aio_dstpolicy->pc_policy.preced)) {
return -1;
}
if (dst2->aio_dstpolicy &&
(dst1->aio_dstpolicy == NULL ||
dst2->aio_dstpolicy->pc_policy.preced >
dst1->aio_dstpolicy->pc_policy.preced)) {
return 1;
}
#endif
/* Rule 7: Prefer native transport. */
/* XXX: not implemented yet */
/* Rule 8: Prefer smaller scope. */
if (dst1->aio_dstscope >= 0 &&
dst1->aio_dstscope < dst2->aio_dstscope) {
return -1;
}
if (dst2->aio_dstscope >= 0 &&
dst2->aio_dstscope < dst1->aio_dstscope) {
return 1;
}
/*
* Rule 9: Use longest matching prefix.
* We compare the match length in a same AF only.
*/
if (dst1->aio_ai->ai_addr->sa_family ==
dst2->aio_ai->ai_addr->sa_family &&
dst1->aio_ai->ai_addr->sa_family != AF_INET) {
if (dst1->aio_matchlen > dst2->aio_matchlen) {
return -1;
}
if (dst1->aio_matchlen < dst2->aio_matchlen) {
return 1;
}
}
/* Rule 10: Otherwise, leave the order unchanged. */
return -1;
}
/*
* Copy from scope.c.
* XXX: we should standardize the functions and link them as standard
* library.
*/
static int
gai_addr2scopetype(struct sockaddr *sa)
{
#ifdef INET6
struct sockaddr_in6 *sa6;
#endif
struct sockaddr_in *sa4;
u_char *p;
switch(sa->sa_family) {
#ifdef INET6
case AF_INET6:
sa6 = (void *)sa;
if (IN6_IS_ADDR_MULTICAST(&sa6->sin6_addr)) {
/* just use the scope field of the multicast address */
return sa6->sin6_addr.s6_addr[2] & 0x0f;
}
/*
* Unicast addresses: map scope type to corresponding scope
* value defined for multcast addresses.
* XXX: hardcoded scope type values are bad...
*/
if (IN6_IS_ADDR_LOOPBACK(&sa6->sin6_addr))
return 1; /* node local scope */
if (IN6_IS_ADDR_LINKLOCAL(&sa6->sin6_addr))
return 2; /* link-local scope */
if (IN6_IS_ADDR_SITELOCAL(&sa6->sin6_addr))
return 5; /* site-local scope */
return 14; /* global scope */
#endif
case AF_INET:
/*
* IPv4 pseudo scoping according to RFC 3484.
*/
sa4 = (void *)sa;
p = (u_char *)(void *)&sa4->sin_addr;
/* IPv4 autoconfiguration addresses have link-local scope. */
if (p[0] == 169 && p[1] == 254)
return 2;
/* Private addresses have site-local scope. */
if (p[0] == 10 ||
(p[0] == 172 && (p[1] & 0xf0) == 16) ||
(p[0] == 192 && p[1] == 168))
return 14; /* XXX: It should be 5 unless NAT */
/* Loopback addresses have link-local scope. */
if (p[0] == 127)
return 2;
return 14;
default:
errno = EAFNOSUPPORT; /* is this a good error? */
return -1;
}
}
/*
* FQDN hostname, DNS lookup
*/
static int
explore_fqdn(const struct addrinfo *pai, const char *hostname,
const char *servname, struct addrinfo **res, struct servent_data *svd)
{
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)
NS_NULL_CB
};
_DIAGASSERT(pai != NULL);
/* hostname may be NULL */
/* servname may be NULL */
_DIAGASSERT(res != NULL);
result = NULL;
/*
* if the servname does not match socktype/protocol, ignore it.
*/
if (get_portmatch(pai, servname, svd) != 0)
return 0;
switch (nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo",
default_dns_files, hostname, pai, servname)) {
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) {
/* Check for already filled port. */
if (*getport(cur))
continue;
GET_PORT(cur, servname, svd);
/* 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, struct servent_data *svd)
{
int s;
const struct afd *afd;
struct addrinfo *cur;
struct addrinfo sentinel;
int error;
_DIAGASSERT(pai != NULL);
/* servname may be NULL */
_DIAGASSERT(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, svd) != 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, svd);
} else {
GET_AI(cur->ai_next, afd, afd->a_loopback);
/* xxx meaningless?
* GET_CANONNAME(cur->ai_next, "localhost");
*/
GET_PORT(cur->ai_next, servname, svd);
}
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,
struct servent_data *svd)
{
const struct afd *afd;
struct addrinfo *cur;
struct addrinfo sentinel;
int error;
char pton[PTON_MAX];
_DIAGASSERT(pai != NULL);
/* hostname may be NULL */
/* servname may be NULL */
_DIAGASSERT(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, svd) != 0)
return 0;
afd = find_afd(pai->ai_family);
if (afd == NULL)
return 0;
switch (afd->a_af) {
case AF_INET:
/*
* RFC3493 section 6.1, requires getaddrinfo() to accept
* AF_INET formats that are accepted by inet_addr(); here
* we use the equivalent inet_aton() function so we can
* check for errors. inet_pton() only accepts addresses
* in the dotted quad format and only in base 10, so we
* need to treat AF_INET specially.
*
* We also check for trailing characters and fail if there
* are any. This matches the inet_pton6(), but not the
* inet_pton4() behavior. We choose to make the protocol
* behavior consistent.
*/
if (inet_aton(hostname, (void *)pton) == 1 &&
hostname[strspn(hostname, "0123456789.xabcdefXABCDEF")]
== '\0') {
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, svd);
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;
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, svd);
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, struct servent_data *svd)
{
#if !defined(SCOPE_DELIMITER) || !defined(INET6)
return explore_numeric(pai, hostname, servname, res, hostname, svd);
#else
const struct afd *afd;
struct addrinfo *cur;
int error;
char *cp, *hostname2 = NULL, *scope, *addr;
struct sockaddr_in6 *sin6;
_DIAGASSERT(pai != NULL);
/* hostname may be NULL */
/* servname may be NULL */
_DIAGASSERT(res != NULL);
/*
* if the servname does not match socktype/protocol, ignore it.
*/
if (get_portmatch(pai, servname, svd) != 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,
svd);
cp = strchr(hostname, SCOPE_DELIMITER);
if (cp == NULL)
return explore_numeric(pai, hostname, servname, res, hostname,
svd);
/*
* 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, svd);
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)
{
_DIAGASSERT(pai != NULL);
_DIAGASSERT(ai != NULL);
_DIAGASSERT(str != NULL);
if ((pai->ai_flags & AI_CANONNAME) != 0) {
ai->ai_canonname = strdup(str);
if (ai->ai_canonname == NULL)
return EAI_MEMORY;
}
return 0;
}
struct addrinfo *
allocaddrinfo(socklen_t addrlen)
{
struct addrinfo *ai;
ai = calloc(sizeof(struct addrinfo) + addrlen, 1);
if (ai) {
ai->ai_addr = (void *)(ai+1);
ai->ai_addrlen = ai->ai_addr->sa_len = addrlen;
}
return ai;
}
static struct addrinfo *
get_ai(const struct addrinfo *pai, const struct afd *afd, const char *addr)
{
char *p;
struct addrinfo *ai;
struct sockaddr *save;
_DIAGASSERT(pai != NULL);
_DIAGASSERT(afd != NULL);
_DIAGASSERT(addr != NULL);
ai = allocaddrinfo((socklen_t)afd->a_socklen);
if (ai == NULL)
return NULL;
save = ai->ai_addr;
memcpy(ai, pai, sizeof(struct addrinfo));
/* since we just overwrote all of ai, we have
to restore ai_addr and ai_addrlen */
ai->ai_addr = save;
ai->ai_addrlen = (socklen_t)afd->a_socklen;
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,
struct servent_data *svd)
{
_DIAGASSERT(ai != NULL);
/* servname may be NULL */
return get_port(ai, servname, 1, svd);
}
static int
get_port(const struct addrinfo *ai, const char *servname, int matchonly,
struct servent_data *svd)
{
const char *proto;
struct servent *sp;
int port;
int allownumeric;
_DIAGASSERT(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:
/*
* This was 0. It is now 1 so that queries specifying
* a NULL hint, or hint without socktype (but, hopefully,
* with protocol) and numeric address actually work.
*/
allownumeric = 1;
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 {
struct servent sv;
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;
}
sp = getservbyname_r(servname, proto, &sv, svd);
if (sp == NULL)
return EAI_SERVICE;
port = sp->s_port;
}
if (!matchonly)
*getport(__UNCONST(ai)) = port;
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;
}
/*
* AI_ADDRCONFIG check: Build a mask containing a bit set for each address
* family configured in the system.
*
*/
static int
addrconfig(uint64_t *mask)
{
struct ifaddrs *ifaddrs, *ifa;
if (getifaddrs(&ifaddrs) == -1)
return -1;
*mask = 0;
for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next)
if (ifa->ifa_addr && (ifa->ifa_flags & IFF_UP)) {
_DIAGASSERT(ifa->ifa_addr->sa_family < 64);
*mask |= (uint64_t)1 << ifa->ifa_addr->sa_family;
}
freeifaddrs(ifaddrs);
return 0;
}
#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;
_DIAGASSERT(scope != NULL);
_DIAGASSERT(sin6 != NULL);
_DIAGASSERT(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\"";
#define maybe_ok(res, nm, ok) (((res)->options & RES_NOCHECKNAME) != 0U || \
(ok)(nm) != 0)
static struct addrinfo *
getanswer(res_state res, const querybuf *answer, int anslen, const char *qname,
int qtype, const struct addrinfo *pai)
{
struct addrinfo sentinel, *cur;
struct addrinfo ai, *aip;
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];
int port, pri, weight;
struct srvinfo *srvlist, *srv, *csrv;
_DIAGASSERT(answer != NULL);
_DIAGASSERT(qname != NULL);
_DIAGASSERT(pai != NULL);
_DIAGASSERT(res != 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;
case T_SRV:
name_ok = gai_srvok;
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, (int)(ep - bp));
if ((n < 0) || !maybe_ok(res, bp, name_ok)) {
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 = (int)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;
srvlist = NULL;
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 */
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, (int)sizeof tbuf);
if ((n < 0) || !maybe_ok(res, tbuf, name_ok)) {
had_error++;
continue;
}
cp += 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));
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) {
struct syslog_data sd = SYSLOG_DATA_INIT;
syslog_r(LOG_NOTICE|LOG_AUTH, &sd,
"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) {
struct syslog_data sd = SYSLOG_DATA_INIT;
syslog_r(LOG_NOTICE|LOG_AUTH, &sd,
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 = (int)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;
case T_SRV:
/* Add to SRV list. Insertion sort on priority. */
pri = _getshort(cp);
cp += INT16SZ;
weight = _getshort(cp);
cp += INT16SZ;
port = _getshort(cp);
cp += INT16SZ;
n = dn_expand(answer->buf, eom, cp, tbuf,
(int)sizeof(tbuf));
if ((n < 0) || !maybe_ok(res, tbuf, res_hnok)) {
had_error++;
continue;
}
cp += n;
if (strlen(tbuf) + 1 >= MAXDNAME) {
had_error++;
continue;
}
srv = malloc(sizeof(*srv));
if (!srv) {
had_error++;
continue;
}
strlcpy(srv->name, tbuf, sizeof(srv->name));
srv->pri = pri;
srv->weight = weight;
srv->port = port;
/* Weight 0 is sorted before other weights. */
if (!srvlist
|| srv->pri < srvlist->pri
|| (srv->pri == srvlist->pri &&
(!srv->weight || srvlist->weight))) {
srv->next = srvlist;
srvlist = srv;
} else {
for (csrv = srvlist;
csrv->next && csrv->next->pri <= srv->pri;
csrv = csrv->next) {
if (csrv->next->pri == srv->pri
&& (!srv->weight ||
csrv->next->weight))
break;
}
srv->next = csrv->next;
csrv->next = srv;
}
continue; /* Don't add to haveanswer yet. */
default:
abort();
}
if (!had_error)
haveanswer++;
}
if (srvlist) {
/*
* Check for explicit rejection.
*/
if (!srvlist->next && !srvlist->name[0]) {
free(srvlist);
h_errno = HOST_NOT_FOUND;
return NULL;
}
while (srvlist) {
struct res_target q, q2;
srv = srvlist;
srvlist = srvlist->next;
/*
* Since res_* doesn't give the additional
* section, we always look up.
*/
memset(&q, 0, sizeof(q));
memset(&q2, 0, sizeof(q2));
q.name = srv->name;
q.qclass = C_IN;
q.qtype = T_AAAA;
q.next = &q2;
q2.name = srv->name;
q2.qclass = C_IN;
q2.qtype = T_A;
aip = _dns_query(&q, pai, res, 0);
if (aip != NULL) {
cur->ai_next = aip;
while (cur && cur->ai_next) {
cur = cur->ai_next;
*getport(cur) = htons(srv->port);
haveanswer++;
}
}
free(srv);
}
}
if (haveanswer) {
if (!sentinel.ai_next->ai_canonname)
(void)get_canonname(pai, sentinel.ai_next,
canonname ? canonname : qname);
h_errno = NETDB_SUCCESS;
return sentinel.ai_next;
}
/* We could have walked a CNAME chain, */
/* but the ultimate target may not have what we looked for */
h_errno = ntohs(hp->ancount) > 0? NO_DATA : NO_RECOVERY;
return NULL;
}
#define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr)
#define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr)
static void
aisort(struct addrinfo *s, res_state res)
{
struct addrinfo head, *t, *p;
int i;
head.ai_next = NULL;
t = &head;
for (i = 0; i < res->nsort; i++) {
p = s;
while (p->ai_next) {
if ((p->ai_next->ai_family != AF_INET)
|| SORTMATCH(p, res->sort_list[i])) {
t->ai_next = p->ai_next;
t = t->ai_next;
p->ai_next = p->ai_next->ai_next;
} else {
p = p->ai_next;
}
}
}
/* add rest of list and reset s to the new list*/
t->ai_next = s->ai_next;
s->ai_next = head.ai_next;
}
static struct addrinfo *
_dns_query(struct res_target *q, const struct addrinfo *pai,
res_state res, int dosearch)
{
struct res_target *q2 = q->next;
querybuf *buf, *buf2;
struct addrinfo sentinel, *cur, *ai;
#ifdef DNS_DEBUG
struct res_target *iter;
for (iter = q; iter; iter = iter->next)
printf("Query type %d for %s\n", iter->qtype, iter->name);
#endif
buf = malloc(sizeof(*buf));
if (buf == NULL) {
h_errno = NETDB_INTERNAL;
return NULL;
}
buf2 = malloc(sizeof(*buf2));
if (buf2 == NULL) {
free(buf);
h_errno = NETDB_INTERNAL;
return NULL;
}
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
q->answer = buf->buf;
q->anslen = sizeof(buf->buf);
if (q2) {
q2->answer = buf2->buf;
q2->anslen = sizeof(buf2->buf);
}
if (dosearch) {
if (res_searchN(q->name, q, res) < 0)
goto out;
} else {
if (res_queryN(q->name, q, res) < 0)
goto out;
}
ai = getanswer(res, buf, q->n, q->name, q->qtype, pai);
if (ai) {
cur->ai_next = ai;
while (cur && cur->ai_next)
cur = cur->ai_next;
}
if (q2) {
ai = getanswer(res, buf2, q2->n, q2->name, q2->qtype, pai);
if (ai)
cur->ai_next = ai;
}
free(buf);
free(buf2);
return sentinel.ai_next;
out:
free(buf);
free(buf2);
return NULL;
}
/*ARGSUSED*/
static struct addrinfo *
_dns_srv_lookup(const char *name, const char *servname,
const struct addrinfo *pai)
{
static const char * const srvprotos[] = { "tcp", "udp" };
static const int srvnottype[] = { SOCK_DGRAM, SOCK_STREAM };
static const int nsrvprotos = 2;
struct addrinfo sentinel, *cur, *ai;
struct servent *serv, sv;
struct servent_data svd;
struct res_target q;
res_state res;
char *tname;
int i;
res = __res_get_state();
if (res == NULL)
return NULL;
memset(&svd, 0, sizeof(svd));
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
/*
* Iterate over supported SRV protocols.
* (currently UDP and TCP only)
*/
for (i = 0; i < nsrvprotos; i++) {
/*
* Check that the caller didn't specify a hint
* which precludes this protocol.
*/
if (pai->ai_socktype == srvnottype[i])
continue;
/*
* If the caller specified a port,
* then lookup the database for the
* official service name.
*/
serv = getservbyname_r(servname, srvprotos[i], &sv, &svd);
if (serv == NULL)
continue;
/*
* Construct service DNS name.
*/
if (asprintf(&tname, "_%s._%s.%s", serv->s_name, serv->s_proto,
name) < 0)
continue;
memset(&q, 0, sizeof(q));
q.name = tname;
q.qclass = C_IN;
q.qtype = T_SRV;
/*
* Do SRV query.
*/
ai = _dns_query(&q, pai, res, 1);
if (ai) {
cur->ai_next = ai;
while (cur && cur->ai_next)
cur = cur->ai_next;
}
free(tname);
}
if (res->nsort)
aisort(&sentinel, res);
__res_put_state(res);
return sentinel.ai_next;
}
/*ARGSUSED*/
static struct addrinfo *
_dns_host_lookup(const char *name, const struct addrinfo *pai)
{
struct res_target q, q2;
struct addrinfo sentinel, *ai;
res_state res;
res = __res_get_state();
if (res == NULL)
return NULL;
memset(&q, 0, sizeof(q2));
memset(&q2, 0, sizeof(q2));
switch (pai->ai_family) {
case AF_UNSPEC:
/* prefer IPv6 */
q.name = name;
q.qclass = C_IN;
q.qtype = T_AAAA;
q.next = &q2;
q2.name = name;
q2.qclass = C_IN;
q2.qtype = T_A;
break;
case AF_INET:
q.name = name;
q.qclass = C_IN;
q.qtype = T_A;
break;
case AF_INET6:
q.name = name;
q.qclass = C_IN;
q.qtype = T_AAAA;
break;
default:
__res_put_state(res);
h_errno = NETDB_INTERNAL;
return NULL;
}
ai = _dns_query(&q, pai, res, 1);
memset(&sentinel, 0, sizeof(sentinel));
sentinel.ai_next = ai;
if (ai != NULL && res->nsort)
aisort(&sentinel, res);
__res_put_state(res);
return sentinel.ai_next;
}
/*ARGSUSED*/
static int
_dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
{
struct addrinfo *ai = NULL;
const char *name, *servname;
const struct addrinfo *pai;
name = va_arg(ap, char *);
pai = va_arg(ap, const struct addrinfo *);
servname = va_arg(ap, char *);
/*
* Try doing SRV lookup on service first.
*/
if (servname
#ifdef AI_SRV
&& (pai->ai_flags & AI_SRV)
#endif
&& !(pai->ai_flags & AI_NUMERICSERV)
&& str2number(servname) == -1) {
#ifdef DNS_DEBUG
printf("%s: try SRV lookup\n", __func__);
#endif
ai = _dns_srv_lookup(name, servname, pai);
}
/*
* Do lookup on name.
*/
if (ai == NULL) {
#ifdef DNS_DEBUG
printf("%s: try HOST lookup\n", __func__);
#endif
ai = _dns_host_lookup(name, pai);
if (ai == NULL) {
switch (h_errno) {
case HOST_NOT_FOUND:
case NO_DATA: // XXX: Perhaps we could differentiate
// So that we could return EAI_NODATA?
return NS_NOTFOUND;
case TRY_AGAIN:
return NS_TRYAGAIN;
default:
return NS_UNAVAIL;
}
}
}
*((struct addrinfo **)rv) = ai;
return NS_SUCCESS;
}
static void
_sethtent(FILE **hostf)
{
if (!*hostf)
*hostf = fopen(_PATH_HOSTS, "re");
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];
_DIAGASSERT(name != NULL);
_DIAGASSERT(pai != NULL);
if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re")))
return NULL;
again:
if (!(p = fgets(hostbuf, (int)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';
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;
#ifndef _REENTRANT
static
#endif
FILE *hostf = NULL;
name = va_arg(ap, char *);
pai = va_arg(ap, const struct addrinfo *);
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;
}
#ifdef YP
/*ARGSUSED*/
static struct addrinfo *
_yphostent(char *line, const struct addrinfo *pai)
{
struct addrinfo sentinel, *cur;
struct addrinfo hints, *res, *res0;
int error;
char *p;
const char *addr, *canonname;
char *nextline;
char *cp;
_DIAGASSERT(line != NULL);
_DIAGASSERT(pai != NULL);
p = line;
addr = canonname = NULL;
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
nextline:
/* terminate line */
cp = strchr(p, '\n');
if (cp) {
*cp++ = '\0';
nextline = cp;
} else
nextline = NULL;
cp = strpbrk(p, " \t");
if (cp == NULL) {
if (canonname == NULL)
return NULL;
else
goto done;
}
*cp++ = '\0';
addr = p;
while (cp && *cp) {
if (*cp == ' ' || *cp == '\t') {
cp++;
continue;
}
if (!canonname)
canonname = cp;
if ((cp = strpbrk(cp, " \t")) != NULL)
*cp++ = '\0';
}
hints = *pai;
hints.ai_flags = AI_NUMERICHOST;
error = getaddrinfo(addr, NULL, &hints, &res0);
if (error == 0) {
for (res = res0; res; res = res->ai_next) {
/* cover it up */
res->ai_flags = pai->ai_flags;
if (pai->ai_flags & AI_CANONNAME)
(void)get_canonname(pai, res, canonname);
}
} else
res0 = NULL;
if (res0) {
cur->ai_next = res0;
while (cur->ai_next)
cur = cur->ai_next;
}
if (nextline) {
p = nextline;
goto nextline;
}
done:
return sentinel.ai_next;
}
/*ARGSUSED*/
static int
_yp_getaddrinfo(void *rv, void *cb_data, va_list ap)
{
struct addrinfo sentinel, *cur;
struct addrinfo *ai = NULL;
char *ypbuf;
int ypbuflen, r;
const char *name;
const struct addrinfo *pai;
char *ypdomain;
if (_yp_check(&ypdomain) == 0)
return NS_UNAVAIL;
name = va_arg(ap, char *);
pai = va_arg(ap, const struct addrinfo *);
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
/* hosts.byname is only for IPv4 (Solaris8) */
if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) {
r = yp_match(ypdomain, "hosts.byname", name,
(int)strlen(name), &ypbuf, &ypbuflen);
if (r == 0) {
struct addrinfo ai4;
ai4 = *pai;
ai4.ai_family = AF_INET;
ai = _yphostent(ypbuf, &ai4);
if (ai) {
cur->ai_next = ai;
while (cur && cur->ai_next)
cur = cur->ai_next;
}
}
free(ypbuf);
}
/* ipnodes.byname can hold both IPv4/v6 */
r = yp_match(ypdomain, "ipnodes.byname", name,
(int)strlen(name), &ypbuf, &ypbuflen);
if (r == 0) {
ai = _yphostent(ypbuf, pai);
if (ai)
cur->ai_next = ai;
free(ypbuf);
}
if (sentinel.ai_next == NULL) {
h_errno = HOST_NOT_FOUND;
return NS_NOTFOUND;
}
*((struct addrinfo **)rv) = sentinel.ai_next;
return NS_SUCCESS;
}
#endif
/* 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 statp)
{
u_char buf[MAXPACKET];
HEADER *hp;
int n;
struct res_target *t;
int rcode;
u_char *rdata;
int ancount;
_DIAGASSERT(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;
u_int oflags;
hp = (HEADER *)(void *)t->answer;
oflags = statp->_flags;
again:
hp->rcode = NOERROR; /* default */
/* make it easier... */
class = t->qclass;
type = t->qtype;
answer = t->answer;
anslen = t->anslen;
#ifdef DEBUG
if (statp->options & RES_DEBUG)
printf(";; res_nquery(%s, %d, %d)\n", name, class, type);
#endif
n = res_nmkquery(statp, QUERY, name, class, type, NULL, 0, NULL,
buf, (int)sizeof(buf));
#ifdef RES_USE_EDNS0
if (n > 0 && (statp->_flags & RES_F_EDNS0ERR) == 0 &&
(statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0) {
n = res_nopt(statp, n, buf, (int)sizeof(buf), anslen);
rdata = &buf[n];
if (n > 0 && (statp->options & RES_NSID) != 0U) {
n = res_nopt_rdata(statp, n, buf,
(int)sizeof(buf),
rdata, NS_OPT_NSID, 0, NULL);
}
}
#endif
if (n <= 0) {
#ifdef DEBUG
if (statp->options & RES_DEBUG)
printf(";; res_nquery: mkquery failed\n");
#endif
h_errno = NO_RECOVERY;
return n;
}
n = res_nsend(statp, buf, n, answer, anslen);
if (n < 0) {
#ifdef RES_USE_EDNS0
/* if the query choked with EDNS0, retry without EDNS0 */
if ((statp->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U &&
((oflags ^ statp->_flags) & RES_F_EDNS0ERR) != 0) {
statp->_flags |= RES_F_EDNS0ERR;
if (statp->options & RES_DEBUG)
printf(";; res_nquery: retry without EDNS0\n");
goto again;
}
#endif
#if 0
#ifdef DEBUG
if (statp->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 (statp->options & RES_DEBUG)
printf(";; rcode = (%s), counts = an:%d ns:%d ar:%d\n",
p_rcode(hp->rcode),
ntohs(hp->ancount),
ntohs(hp->nscount),
ntohs(hp->arcount));
#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;
char buf[MAXHOSTNAMELEN];
int trailing_dot, ret, saved_herrno;
int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
_DIAGASSERT(name != NULL);
_DIAGASSERT(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++;
/*
* if there aren't any dots, it could be a user-level alias
*/
if (!dots && (cp = res_hostalias(res, name, buf, sizeof(buf))) != 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;
_DIAGASSERT(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);
}
#ifdef TEST
int
main(int argc, char *argv[]) {
struct addrinfo *ai, *sai;
int i, e;
char buf[1024];
for (i = 1; i < argc; i++) {
if ((e = getaddrinfo(argv[i], NULL, NULL, &sai)) != 0)
warnx("%s: %s", argv[i], gai_strerror(e));
for (ai = sai; ai; ai = ai->ai_next) {
sockaddr_snprintf(buf, sizeof(buf), "%a", ai->ai_addr);
printf("flags=0x%x family=%d socktype=%d protocol=%d "
"addrlen=%zu addr=%s canonname=%s next=%p\n",
ai->ai_flags,
ai->ai_family,
ai->ai_socktype,
ai->ai_protocol,
(size_t)ai->ai_addrlen,
buf,
ai->ai_canonname,
ai->ai_next);
}
if (sai)
freeaddrinfo(sai);
}
return 0;
}
#endif
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