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freebsd-nq/lib/libc/net/getaddrinfo.c
Jilles Tjoelker 7253197882 libc: Use SOCK_CLOEXEC for various internal file descriptors. 
This change avoids undesirably passing some internal file descriptors to a
process created (fork+exec) by another thread.

Kernel support for SOCK_CLOEXEC was added in r248534, March 19, 2013.
2013-09-06 21:02:06 +00:00

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/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 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.
*/
/*
* "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator.
*
* 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.
* - 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?
*
* OS specific notes for freebsd4:
* - FreeBSD supported $GAI. The code does not.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <sys/queue.h>
#ifdef INET6
#include <net/if_var.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>
#include <netinet6/in6_var.h> /* XXX */
#endif
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#include <netdb.h>
#include <resolv.h>
#include <string.h>
#include <stdlib.h>
#include <stddef.h>
#include <ctype.h>
#include <unistd.h>
#include <stdio.h>
#include <errno.h>
#include "res_config.h"
#ifdef DEBUG
#include <syslog.h>
#endif
#include <stdarg.h>
#include <nsswitch.h>
#include "un-namespace.h"
#include "libc_private.h"
#ifdef NS_CACHING
#include "nscache.h"
#endif
#if defined(__KAME__) && defined(INET6)
# define FAITH
#endif
#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
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;
socklen_t a_socklen;
int a_off;
const char *a_addrany;
const char *a_loopback;
int a_scoped;
} afdl [] = {
#ifdef INET6
#define N_INET6 0
{PF_INET6, sizeof(struct in6_addr),
sizeof(struct sockaddr_in6),
offsetof(struct sockaddr_in6, sin6_addr),
in6_addrany, in6_loopback, 1},
#define N_INET 1
#else
#define N_INET 0
#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;
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, ANY, ANY, 0x01 },
#endif
#ifdef INET6
{ PF_INET6, SOCK_DGRAM, IPPROTO_UDP, 0x07 },
{ PF_INET6, SOCK_STREAM, IPPROTO_TCP, 0x07 },
{ PF_INET6, SOCK_STREAM, IPPROTO_SCTP, 0x03 },
{ PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 },
{ PF_INET6, SOCK_RAW, ANY, 0x05 },
#endif
{ PF_INET, SOCK_DGRAM, IPPROTO_UDP, 0x07 },
{ PF_INET, SOCK_STREAM, IPPROTO_TCP, 0x07 },
{ PF_INET, SOCK_STREAM, IPPROTO_SCTP, 0x03 },
{ PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, 0x07 },
{ PF_INET, SOCK_RAW, ANY, 0x05 },
{ -1, 0, 0, 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 }
};
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 */
};
#define MAXPACKET (64*1024)
typedef union {
HEADER hdr;
u_char buf[MAXPACKET];
} querybuf;
static int str2number(const char *, int *);
static int explore_copy(const struct addrinfo *, const struct addrinfo *,
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 struct addrinfo *copy_ai(const struct addrinfo *);
static int get_portmatch(const struct addrinfo *, const char *);
static int get_port(struct addrinfo *, const char *, int);
static const struct afd *find_afd(int);
static int addrconfig(struct addrinfo *);
static void set_source(struct ai_order *, struct policyhead *);
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 explore_fqdn(const struct addrinfo *, const char *,
const char *, struct addrinfo **);
static int reorder(struct addrinfo *);
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(const querybuf *, int, const char *, int,
const struct addrinfo *, res_state);
#if defined(RESOLVSORT)
static int addr4sort(struct addrinfo *, res_state);
#endif
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
#ifdef NS_CACHING
static int addrinfo_id_func(char *, size_t *, va_list, void *);
static int addrinfo_marshal_func(char *, size_t *, void *, va_list, void *);
static int addrinfo_unmarshal_func(char *, size_t, void *, va_list, void *);
#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);
/* 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)))
void
freeaddrinfo(struct addrinfo *ai)
{
struct addrinfo *next;
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, int *portp)
{
char *ep;
unsigned long v;
if (*p == '\0')
return -1;
ep = NULL;
errno = 0;
v = strtoul(p, &ep, 10);
if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX) {
*portp = v;
return 0;
} 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, ai0, *afai;
struct addrinfo *pai;
const struct afd *afd;
const struct explore *ex;
struct addrinfo *afailist[sizeof(afdl)/sizeof(afdl[0])];
struct addrinfo *afai_unspec;
int found;
int numeric = 0;
/* ensure we return NULL on errors */
*res = NULL;
memset(&ai, 0, sizeof(ai));
memset(afailist, 0, sizeof(afailist));
afai_unspec = 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 (!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;
/* matched */
break;
}
if (ex->e_af < 0)
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)
goto bad;
*pai = ai0;
}
ai0 = *pai;
/*
* NULL hostname, or numeric hostname.
* If numeric representation of AF1 can be interpreted as FQDN
* representation of AF2, we need to think again about the code below.
*/
found = 0;
for (afd = afdl; afd->a_af; afd++) {
*pai = ai0;
if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1))
continue;
if (pai->ai_family == PF_UNSPEC)
pai->ai_family = afd->a_af;
if (hostname == NULL) {
error = explore_null(pai, servname,
&afailist[afd - afdl]);
/*
* Errors from explore_null should be unexpected and
* be caught to avoid returning an incomplete result.
*/
if (error != 0)
goto bad;
} else {
error = explore_numeric_scope(pai, hostname, servname,
&afailist[afd - afdl]);
/*
* explore_numeric_scope returns an error for address
* families that do not match that of hostname.
* Thus we should not catch the error at this moment.
*/
}
if (!error && afailist[afd - afdl])
found++;
}
if (found) {
numeric = 1;
goto globcopy;
}
if (hostname == NULL)
ERR(EAI_NONAME); /* used to be EAI_NODATA */
if (pai->ai_flags & AI_NUMERICHOST)
ERR(EAI_NONAME);
if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0))
ERR(EAI_FAIL);
/*
* hostname as alphabetical name.
*/
*pai = ai0;
error = explore_fqdn(pai, hostname, servname, &afai_unspec);
globcopy:
for (ex = explore; ex->e_af >= 0; ex++) {
*pai = ai0;
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 the servname does not match socktype/protocol, ignore it.
*/
if (get_portmatch(pai, servname) != 0)
continue;
if (afai_unspec)
afai = afai_unspec;
else {
if ((afd = find_afd(pai->ai_family)) == NULL)
continue;
/* XXX assumes that afd points inside afdl[] */
afai = afailist[afd - afdl];
}
if (!afai)
continue;
error = explore_copy(pai, afai, &cur->ai_next);
if (error != 0)
goto bad;
while (cur && cur->ai_next)
cur = cur->ai_next;
}
/*
* ensure we return either:
* - error == 0, non-NULL *res
* - error != 0, NULL *res
*/
if (error == 0) {
if (sentinel.ai_next) {
/*
* 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);
if (sentinel.ai_next->ai_canonname ==
NULL) {
sentinel.ai_next->ai_canonname
= canonname;
} else if (canonname != NULL)
free(canonname);
}
}
*res = sentinel.ai_next;
} else
error = EAI_FAIL;
}
bad:
if (afai_unspec)
freeaddrinfo(afai_unspec);
for (afd = afdl; afd->a_af; afd++) {
if (afailist[afd - afdl])
freeaddrinfo(afailist[afd - afdl]);
}
if (!*res)
if (sentinel.ai_next)
freeaddrinfo(sentinel.ai_next);
return (error);
}
static int
reorder(struct addrinfo *sentinel)
{
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);
}
/* 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
int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, IPV6CTL_ADDRCTLPOLICY };
size_t l;
char *buf;
struct in6_addrpolicy *pol, *ep;
if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0)
return (0);
if (l == 0)
return (0);
if ((buf = malloc(l)) == NULL)
return (0);
if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), buf, &l, NULL, 0) < 0) {
free(buf);
return (0);
}
ep = (struct in6_addrpolicy *)(buf + l);
for (pol = (struct in6_addrpolicy *)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 matchlen, bestmatchlen = -1;
u_char *mp, *ep, *k, *p, m;
struct sockaddr_in6 key;
switch(addr->sa_family) {
case AF_INET6:
key = *(struct sockaddr_in6 *)addr;
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],
&((struct sockaddr_in *)addr)->sin_addr, 4);
break;
default:
return(NULL);
}
for (ent = TAILQ_FIRST(head); ent; ent = TAILQ_NEXT(ent, pc_entry)) {
pol = &ent->pc_policy;
matchlen = 0;
mp = (u_char *)&pol->addrmask.sin6_addr;
ep = mp + 16; /* XXX: scope field? */
k = (u_char *)&key.sin6_addr;
p = (u_char *)&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 */
matchlen += 8;
else {
while (m >= 0x80) {
matchlen++;
m <<= 1;
}
}
}
/* matched. check if this is better than the current best. */
if (matchlen > bestmatchlen) {
bestent = ent;
bestmatchlen = matchlen;
}
next:
continue;
}
return(bestent);
#else
return(NULL);
#endif
}
static void
set_source(struct ai_order *aio, struct policyhead *ph)
{
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 = (struct sockaddr *)&ss;
get_port(&ai, "1", 0);
/* 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, r;
int addrlen;
switch (src->sa_family) {
#ifdef INET6
case AF_INET6:
s = (u_char *)&((struct sockaddr_in6 *)src)->sin6_addr;
d = (u_char *)&((struct sockaddr_in6 *)dst)->sin6_addr;
addrlen = sizeof(struct in6_addr);
lim = s + addrlen;
break;
#endif
case AF_INET:
s = (u_char *)&((struct sockaddr_in *)src)->sin_addr;
d = (u_char *)&((struct sockaddr_in *)dst)->sin_addr;
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) {
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;
switch(sa->sa_family) {
#ifdef INET6
case AF_INET6:
sa6 = (struct sockaddr_in6 *)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 */
break;
#endif
case AF_INET:
/*
* IPv4 pseudo scoping according to RFC 3484.
*/
sa4 = (struct sockaddr_in *)sa;
/* IPv4 autoconfiguration addresses have link-local scope. */
if (((u_char *)&sa4->sin_addr)[0] == 169 &&
((u_char *)&sa4->sin_addr)[1] == 254)
return(2);
/* Private addresses have site-local scope. */
if (((u_char *)&sa4->sin_addr)[0] == 10 ||
(((u_char *)&sa4->sin_addr)[0] == 172 &&
(((u_char *)&sa4->sin_addr)[1] & 0xf0) == 16) ||
(((u_char *)&sa4->sin_addr)[0] == 192 &&
((u_char *)&sa4->sin_addr)[1] == 168))
return(14); /* XXX: It should be 5 unless NAT */
/* Loopback addresses have link-local scope. */
if (((u_char *)&sa4->sin_addr)[0] == 127)
return(2);
return(14);
break;
default:
errno = EAFNOSUPPORT; /* is this a good error? */
return(-1);
}
}
static int
explore_copy(const struct addrinfo *pai, const struct addrinfo *src0,
struct addrinfo **res)
{
int error;
struct addrinfo sentinel, *cur;
const struct addrinfo *src;
error = 0;
sentinel.ai_next = NULL;
cur = &sentinel;
for (src = src0; src != NULL; src = src->ai_next) {
if (src->ai_family != pai->ai_family)
continue;
cur->ai_next = copy_ai(src);
if (!cur->ai_next) {
error = EAI_MEMORY;
goto fail;
}
cur->ai_next->ai_socktype = pai->ai_socktype;
cur->ai_next->ai_protocol = pai->ai_protocol;
cur = cur->ai_next;
}
*res = sentinel.ai_next;
return 0;
fail:
freeaddrinfo(sentinel.ai_next);
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 *ai;
int error;
*res = NULL;
ai = NULL;
/*
* filter out AFs that are not supported by the kernel
* XXX errno?
*/
s = _socket(pai->ai_family, SOCK_DGRAM | SOCK_CLOEXEC, 0);
if (s < 0) {
if (errno != EMFILE)
return 0;
} else
_close(s);
afd = find_afd(pai->ai_family);
if (afd == NULL)
return 0;
if (pai->ai_flags & AI_PASSIVE) {
GET_AI(ai, afd, afd->a_addrany);
GET_PORT(ai, servname);
} else {
GET_AI(ai, afd, afd->a_loopback);
GET_PORT(ai, servname);
}
*res = ai;
return 0;
free:
if (ai != NULL)
freeaddrinfo(ai);
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 *ai;
int error;
char pton[PTON_MAX];
*res = NULL;
ai = NULL;
afd = find_afd(pai->ai_family);
if (afd == NULL)
return 0;
switch (afd->a_af) {
case AF_INET:
/*
* RFC3493 requires getaddrinfo() to accept AF_INET formats
* that are accepted by inet_addr() and its family. The
* accepted forms includes the "classful" one, which inet_pton
* does not accept. So we need to separate the case for
* AF_INET.
*/
if (inet_aton(hostname, (struct in_addr *)pton) != 1)
return 0;
break;
default:
if (inet_pton(afd->a_af, hostname, pton) != 1)
return 0;
break;
}
if (pai->ai_family == afd->a_af) {
GET_AI(ai, afd, pton);
GET_PORT(ai, servname);
if ((pai->ai_flags & AI_CANONNAME)) {
/*
* Set the numeric address itself as the canonical
* name, based on a clarification in RFC3493.
*/
GET_CANONNAME(ai, canonname);
}
} else {
/*
* XXX: This should not happen since we already matched the AF
* by find_afd.
*/
ERR(EAI_FAMILY);
}
*res = ai;
return 0;
free:
bad:
if (ai != NULL)
freeaddrinfo(ai);
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;
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);
freeaddrinfo(*res);
*res = NULL;
return(EAI_NONAME); /* XXX: is return OK? */
}
sin6->sin6_scope_id = scopeid;
}
}
free(hostname2);
if (error && *res) {
freeaddrinfo(*res);
*res = NULL;
}
return error;
#endif
}
static int
get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
{
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;
#ifdef FAITH
struct in6_addr faith_prefix;
char *fp_str;
int translate = 0;
#endif
#ifdef FAITH
/*
* Transfrom an IPv4 addr into a special IPv6 addr format for
* IPv6->IPv4 translation gateway. (only TCP is supported now)
*
* +-----------------------------------+------------+
* | faith prefix part (12 bytes) | embedded |
* | | IPv4 addr part (4 bytes)
* +-----------------------------------+------------+
*
* faith prefix part is specified as ascii IPv6 addr format
* in environmental variable GAI.
* For FAITH to work correctly, routing to faith prefix must be
* setup toward a machine where a FAITH daemon operates.
* Also, the machine must enable some mechanizm
* (e.g. faith interface hack) to divert those packet with
* faith prefixed destination addr to user-land FAITH daemon.
*/
fp_str = getenv("GAI");
if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 &&
afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) {
u_int32_t v4a;
u_int8_t v4a_top;
memcpy(&v4a, addr, sizeof v4a);
v4a_top = v4a >> IN_CLASSA_NSHIFT;
if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) &&
v4a_top != 0 && v4a != IN_LOOPBACKNET) {
afd = &afdl[N_INET6];
memcpy(&faith_prefix.s6_addr[12], addr,
sizeof(struct in_addr));
translate = 1;
}
}
#endif
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);
ai->ai_addr->sa_len = afd->a_socklen;
ai->ai_addrlen = afd->a_socklen;
ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
p = (char *)(void *)(ai->ai_addr);
#ifdef FAITH
if (translate == 1)
memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen);
else
#endif
memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
return ai;
}
/* XXX need to malloc() the same way we do from other functions! */
static struct addrinfo *
copy_ai(const struct addrinfo *pai)
{
struct addrinfo *ai;
size_t l;
l = sizeof(*ai) + pai->ai_addrlen;
if ((ai = (struct addrinfo *)malloc(l)) == NULL)
return NULL;
memset(ai, 0, l);
memcpy(ai, pai, sizeof(*ai));
ai->ai_addr = (struct sockaddr *)(void *)(ai + 1);
memcpy(ai->ai_addr, pai->ai_addr, pai->ai_addrlen);
if (pai->ai_canonname) {
l = strlen(pai->ai_canonname) + 1;
if ((ai->ai_canonname = malloc(l)) == NULL) {
free(ai);
return NULL;
}
strlcpy(ai->ai_canonname, pai->ai_canonname, l);
} else {
/* just to make sure */
ai->ai_canonname = NULL;
}
ai->ai_next = NULL;
return ai;
}
static int
get_portmatch(const struct addrinfo *ai, const char *servname)
{
/* get_port does not touch first argument when matchonly == 1. */
/* LINTED const cast */
return get_port((struct addrinfo *)ai, servname, 1);
}
static int
get_port(struct addrinfo *ai, const char *servname, int matchonly)
{
const char *proto;
struct servent *sp;
int port, error;
int allownumeric;
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:
case SOCK_SEQPACKET:
allownumeric = 1;
break;
case ANY:
switch (ai->ai_family) {
case AF_INET:
#ifdef AF_INET6
case AF_INET6:
#endif
allownumeric = 1;
break;
default:
allownumeric = 0;
break;
}
break;
default:
return EAI_SOCKTYPE;
}
error = str2number(servname, &port);
if (error == 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_protocol) {
case IPPROTO_UDP:
proto = "udp";
break;
case IPPROTO_TCP:
proto = "tcp";
break;
case IPPROTO_SCTP:
proto = "sctp";
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;
}
/*
* post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend
* will take care of it.
* the semantics of AI_ADDRCONFIG is not defined well. we are not sure
* if the code is right or not.
*
* XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with
* _dns_getaddrinfo.
*/
static int
addrconfig(struct addrinfo *pai)
{
int s, af;
/*
* TODO:
* Note that implementation dependent test for address
* configuration should be done everytime called
* (or apropriate interval),
* because addresses will be dynamically assigned or deleted.
*/
af = pai->ai_family;
if (af == AF_UNSPEC) {
if ((s = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0)
af = AF_INET;
else {
_close(s);
if ((s = _socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC,
0)) < 0)
af = AF_INET6;
else
_close(s);
}
}
if (af != AF_UNSPEC) {
if ((s = _socket(af, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0)
return 0;
_close(s);
}
pai->ai_family = af;
return 1;
}
#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;
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) ||
IN6_IS_ADDR_MC_NODELOCAL(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
#ifdef NS_CACHING
static int
addrinfo_id_func(char *buffer, size_t *buffer_size, va_list ap,
void *cache_mdata)
{
res_state statp;
u_long res_options;
const int op_id = 0; /* identifies the getaddrinfo for the cache */
char *hostname;
struct addrinfo *hints;
char *p;
int ai_flags, ai_family, ai_socktype, ai_protocol;
size_t desired_size, size;
statp = __res_state();
res_options = statp->options & (RES_RECURSE | RES_DEFNAMES |
RES_DNSRCH | RES_NOALIASES | RES_USE_INET6);
hostname = va_arg(ap, char *);
hints = va_arg(ap, struct addrinfo *);
desired_size = sizeof(res_options) + sizeof(int) + sizeof(int) * 4;
if (hostname != NULL) {
size = strlen(hostname);
desired_size += size + 1;
} else
size = 0;
if (desired_size > *buffer_size) {
*buffer_size = desired_size;
return (NS_RETURN);
}
if (hints == NULL)
ai_flags = ai_family = ai_socktype = ai_protocol = 0;
else {
ai_flags = hints->ai_flags;
ai_family = hints->ai_family;
ai_socktype = hints->ai_socktype;
ai_protocol = hints->ai_protocol;
}
p = buffer;
memcpy(p, &res_options, sizeof(res_options));
p += sizeof(res_options);
memcpy(p, &op_id, sizeof(int));
p += sizeof(int);
memcpy(p, &ai_flags, sizeof(int));
p += sizeof(int);
memcpy(p, &ai_family, sizeof(int));
p += sizeof(int);
memcpy(p, &ai_socktype, sizeof(int));
p += sizeof(int);
memcpy(p, &ai_protocol, sizeof(int));
p += sizeof(int);
if (hostname != NULL)
memcpy(p, hostname, size);
*buffer_size = desired_size;
return (NS_SUCCESS);
}
static int
addrinfo_marshal_func(char *buffer, size_t *buffer_size, void *retval,
va_list ap, void *cache_mdata)
{
struct addrinfo *ai, *cai;
char *p;
size_t desired_size, size, ai_size;
ai = *((struct addrinfo **)retval);
desired_size = sizeof(size_t);
ai_size = 0;
for (cai = ai; cai != NULL; cai = cai->ai_next) {
desired_size += sizeof(struct addrinfo) + cai->ai_addrlen;
if (cai->ai_canonname != NULL)
desired_size += sizeof(size_t) +
strlen(cai->ai_canonname);
++ai_size;
}
if (desired_size > *buffer_size) {
/* this assignment is here for future use */
errno = ERANGE;
*buffer_size = desired_size;
return (NS_RETURN);
}
memset(buffer, 0, desired_size);
p = buffer;
memcpy(p, &ai_size, sizeof(size_t));
p += sizeof(size_t);
for (cai = ai; cai != NULL; cai = cai->ai_next) {
memcpy(p, cai, sizeof(struct addrinfo));
p += sizeof(struct addrinfo);
memcpy(p, cai->ai_addr, cai->ai_addrlen);
p += cai->ai_addrlen;
if (cai->ai_canonname != NULL) {
size = strlen(cai->ai_canonname);
memcpy(p, &size, sizeof(size_t));
p += sizeof(size_t);
memcpy(p, cai->ai_canonname, size);
p += size;
}
}
return (NS_SUCCESS);
}
static int
addrinfo_unmarshal_func(char *buffer, size_t buffer_size, void *retval,
va_list ap, void *cache_mdata)
{
struct addrinfo new_ai, *result, *sentinel, *lasts;
char *p;
size_t ai_size, ai_i, size;
p = buffer;
memcpy(&ai_size, p, sizeof(size_t));
p += sizeof(size_t);
result = NULL;
lasts = NULL;
for (ai_i = 0; ai_i < ai_size; ++ai_i) {
memcpy(&new_ai, p, sizeof(struct addrinfo));
p += sizeof(struct addrinfo);
size = new_ai.ai_addrlen + sizeof(struct addrinfo) +
_ALIGNBYTES;
sentinel = (struct addrinfo *)malloc(size);
memset(sentinel, 0, size);
memcpy(sentinel, &new_ai, sizeof(struct addrinfo));
sentinel->ai_addr = (struct sockaddr *)_ALIGN((char *)sentinel +
sizeof(struct addrinfo));
memcpy(sentinel->ai_addr, p, new_ai.ai_addrlen);
p += new_ai.ai_addrlen;
if (new_ai.ai_canonname != NULL) {
memcpy(&size, p, sizeof(size_t));
p += sizeof(size_t);
sentinel->ai_canonname = (char *)malloc(size + 1);
memset(sentinel->ai_canonname, 0, size + 1);
memcpy(sentinel->ai_canonname, p, size);
p += size;
}
if (result == NULL) {
result = sentinel;
lasts = sentinel;
} else {
lasts->ai_next = sentinel;
lasts = sentinel;
}
}
*((struct addrinfo **)retval) = result;
return (NS_SUCCESS);
}
#endif /* NS_CACHING */
/*
* 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;
#ifdef NS_CACHING
static const nss_cache_info cache_info =
NS_COMMON_CACHE_INFO_INITIALIZER(
hosts, NULL, addrinfo_id_func, addrinfo_marshal_func,
addrinfo_unmarshal_func);
#endif
static const ns_dtab dtab[] = {
NS_FILES_CB(_files_getaddrinfo, NULL)
{ NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */
NS_NIS_CB(_yp_getaddrinfo, NULL)
#ifdef NS_CACHING
NS_CACHE_CB(&cache_info)
#endif
{ 0 }
};
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_NONAME;
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;
}
#ifdef DEBUG
static const char AskedForGot[] =
"gethostby*.getanswer: asked for \"%s\", got \"%s\"";
#endif
static struct addrinfo *
getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
const struct addrinfo *pai, res_state res)
{
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];
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) {
RES_SET_H_ERRNO(res, NO_RECOVERY);
return (NULL);
}
n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
if ((n < 0) || !(*name_ok)(bp)) {
RES_SET_H_ERRNO(res, 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) {
RES_SET_H_ERRNO(res, 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, 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) {
#ifdef DEBUG
if (type != T_KEY && type != T_SIG &&
type != ns_t_dname)
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));
#endif
cp += n;
continue; /* XXX - had_error++ ? */
}
switch (type) {
case T_A:
case T_AAAA:
if (strcasecmp(canonname, bp) != 0) {
#ifdef DEBUG
syslog(LOG_NOTICE|LOG_AUTH,
AskedForGot, canonname, bp);
#endif
cp += n;
continue; /* XXX - had_error++ ? */
}
if (type == T_A && n != INADDRSZ) {
cp += n;
continue;
}
if (type == T_AAAA && n != IN6ADDRSZ) {
cp += n;
continue;
}
#ifdef FILTER_V4MAPPED
if (type == T_AAAA) {
struct in6_addr in6;
memcpy(&in6, cp, sizeof(in6));
if (IN6_IS_ADDR_V4MAPPED(&in6)) {
cp += n;
continue;
}
}
#endif
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 defined(RESOLVSORT)
/*
* We support only IPv4 address for backward
* compatibility against gethostbyname(3).
*/
if (res->nsort && qtype == T_A) {
if (addr4sort(&sentinel, res) < 0) {
freeaddrinfo(sentinel.ai_next);
RES_SET_H_ERRNO(res, NO_RECOVERY);
return NULL;
}
}
#endif /*RESOLVSORT*/
if (!canonname)
(void)get_canonname(pai, sentinel.ai_next, qname);
else
(void)get_canonname(pai, sentinel.ai_next, canonname);
RES_SET_H_ERRNO(res, NETDB_SUCCESS);
return sentinel.ai_next;
}
RES_SET_H_ERRNO(res, NO_RECOVERY);
return NULL;
}
#ifdef RESOLVSORT
struct addr_ptr {
struct addrinfo *ai;
int aval;
};
static int
addr4sort(struct addrinfo *sentinel, res_state res)
{
struct addrinfo *ai;
struct addr_ptr *addrs, addr;
struct sockaddr_in *sin;
int naddrs, i, j;
int needsort = 0;
if (!sentinel)
return -1;
naddrs = 0;
for (ai = sentinel->ai_next; ai; ai = ai->ai_next)
naddrs++;
if (naddrs < 2)
return 0; /* We don't need sorting. */
if ((addrs = malloc(sizeof(struct addr_ptr) * naddrs)) == NULL)
return -1;
i = 0;
for (ai = sentinel->ai_next; ai; ai = ai->ai_next) {
sin = (struct sockaddr_in *)ai->ai_addr;
for (j = 0; (unsigned)j < res->nsort; j++) {
if (res->sort_list[j].addr.s_addr ==
(sin->sin_addr.s_addr & res->sort_list[j].mask))
break;
}
addrs[i].ai = ai;
addrs[i].aval = j;
if (needsort == 0 && i > 0 && j < addrs[i - 1].aval)
needsort = i;
i++;
}
if (!needsort) {
free(addrs);
return 0;
}
while (needsort < naddrs) {
for (j = needsort - 1; j >= 0; j--) {
if (addrs[j].aval > addrs[j+1].aval) {
addr = addrs[j];
addrs[j] = addrs[j + 1];
addrs[j + 1] = addr;
} else
break;
}
needsort++;
}
ai = sentinel;
for (i = 0; i < naddrs; ++i) {
ai->ai_next = addrs[i].ai;
ai = ai->ai_next;
}
ai->ai_next = NULL;
free(addrs);
return 0;
}
#endif /*RESOLVSORT*/
/*ARGSUSED*/
static int
_dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
{
struct addrinfo *ai;
querybuf *buf, *buf2;
const char *hostname;
const struct addrinfo *pai;
struct addrinfo sentinel, *cur;
struct res_target q, q2;
res_state res;
hostname = va_arg(ap, char *);
pai = va_arg(ap, const struct addrinfo *);
memset(&q, 0, sizeof(q));
memset(&q2, 0, sizeof(q2));
memset(&sentinel, 0, sizeof(sentinel));
cur = &sentinel;
buf = malloc(sizeof(*buf));
if (!buf) {
RES_SET_H_ERRNO(res, NETDB_INTERNAL);
return NS_NOTFOUND;
}
buf2 = malloc(sizeof(*buf2));
if (!buf2) {
free(buf);
RES_SET_H_ERRNO(res, NETDB_INTERNAL);
return NS_NOTFOUND;
}
switch (pai->ai_family) {
case AF_UNSPEC:
q.name = hostname;
q.qclass = C_IN;
q.qtype = T_A;
q.answer = buf->buf;
q.anslen = sizeof(buf->buf);
q.next = &q2;
q2.name = hostname;
q2.qclass = C_IN;
q2.qtype = T_AAAA;
q2.answer = buf2->buf;
q2.anslen = sizeof(buf2->buf);
break;
case AF_INET:
q.name = hostname;
q.qclass = C_IN;
q.qtype = T_A;
q.answer = buf->buf;
q.anslen = sizeof(buf->buf);
break;
case AF_INET6:
q.name = hostname;
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_state();
if ((res->options & RES_INIT) == 0 && res_ninit(res) == -1) {
RES_SET_H_ERRNO(res, NETDB_INTERNAL);
free(buf);
free(buf2);
return NS_NOTFOUND;
}
if (res_searchN(hostname, &q, res) < 0) {
free(buf);
free(buf2);
return NS_NOTFOUND;
}
/* prefer IPv6 */
if (q.next) {
ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai, res);
if (ai) {
cur->ai_next = ai;
while (cur && cur->ai_next)
cur = cur->ai_next;
}
}
ai = getanswer(buf, q.n, q.name, q.qtype, pai, res);
if (ai)
cur->ai_next = ai;
free(buf);
free(buf2);
if (sentinel.ai_next == NULL)
switch (res->res_h_errno) {
case HOST_NOT_FOUND:
return NS_NOTFOUND;
case TRY_AGAIN:
return NS_TRYAGAIN;
default:
return NS_UNAVAIL;
}
*((struct addrinfo **)rv) = sentinel.ai_next;
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];
if (!*hostf && !(*hostf = fopen(_PATH_HOSTS, "re")))
return (NULL);
again:
if (!(p = fgets(hostbuf, sizeof hostbuf, *hostf)))
return (NULL);
if (*p == '#')
goto again;
cp = strpbrk(p, "#\n");
if (cp != NULL)
*cp = '\0';
if (!(cp = strpbrk(p, " \t")))
goto again;
*cp++ = '\0';
addr = p;
cname = NULL;
/* if this is not something we're looking for, skip it. */
while (cp && *cp) {
if (*cp == ' ' || *cp == '\t') {
cp++;
continue;
}
tname = cp;
if (cname == NULL)
cname = cp;
if ((cp = strpbrk(cp, " \t")) != NULL)
*cp++ = '\0';
if (strcasecmp(name, tname) == 0)
goto found;
}
goto again;
found:
/* we should not glob socktype/protocol here */
memset(&hints, 0, sizeof(hints));
hints.ai_family = pai->ai_family;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = 0;
hints.ai_flags = AI_NUMERICHOST;
error = getaddrinfo(addr, "0", &hints, &res0);
if (error)
goto again;
#ifdef FILTER_V4MAPPED
/* XXX should check all items in the chain */
if (res0->ai_family == AF_INET6 &&
IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) {
freeaddrinfo(res0);
goto again;
}
#endif
for (res = res0; res; res = res->ai_next) {
/* cover it up */
res->ai_flags = pai->ai_flags;
res->ai_socktype = pai->ai_socktype;
res->ai_protocol = pai->ai_protocol;
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 *);
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 = line;
const char *addr, *canonname;
char *nextline;
char *cp;
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 && 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) {
RES_SET_H_ERRNO(__res_state(), 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, struct res_target *target, res_state res)
{
u_char *buf;
HEADER *hp;
int n;
u_int oflags;
struct res_target *t;
int rcode;
int ancount;
rcode = NOERROR;
ancount = 0;
buf = malloc(MAXPACKET);
if (!buf) {
RES_SET_H_ERRNO(res, NETDB_INTERNAL);
return -1;
}
for (t = target; t; t = t->next) {
int class, type;
u_char *answer;
int anslen;
hp = (HEADER *)(void *)t->answer;
/* make it easier... */
class = t->qclass;
type = t->qtype;
answer = t->answer;
anslen = t->anslen;
oflags = res->_flags;
again:
hp->rcode = NOERROR; /* default */
#ifdef DEBUG
if (res->options & RES_DEBUG)
printf(";; res_query(%s, %d, %d)\n", name, class, type);
#endif
n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL,
buf, MAXPACKET);
if (n > 0 && (res->_flags & RES_F_EDNS0ERR) == 0 &&
(res->options & (RES_USE_EDNS0|RES_USE_DNSSEC)) != 0U)
n = res_nopt(res, n, buf, MAXPACKET, anslen);
if (n <= 0) {
#ifdef DEBUG
if (res->options & RES_DEBUG)
printf(";; res_query: mkquery failed\n");
#endif
free(buf);
RES_SET_H_ERRNO(res, NO_RECOVERY);
return (n);
}
n = res_nsend(res, buf, n, answer, anslen);
if (n < 0) {
/*
* if the query choked with EDNS0, retry
* without EDNS0
*/
if ((res->options & (RES_USE_EDNS0|RES_USE_DNSSEC))
!= 0U &&
((oflags ^ res->_flags) & RES_F_EDNS0ERR) != 0) {
res->_flags |= RES_F_EDNS0ERR;
if (res->options & RES_DEBUG)
printf(";; res_nquery: retry without EDNS0\n");
goto again;
}
rcode = hp->rcode; /* record most recent error */
#ifdef DEBUG
if (res->options & RES_DEBUG)
printf(";; res_query: send error\n");
#endif
continue;
}
if (n > anslen)
hp->rcode = FORMERR; /* XXX not very informative */
if (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;
}
free(buf);
if (ancount == 0) {
switch (rcode) {
case NXDOMAIN:
RES_SET_H_ERRNO(res, HOST_NOT_FOUND);
break;
case SERVFAIL:
RES_SET_H_ERRNO(res, TRY_AGAIN);
break;
case NOERROR:
RES_SET_H_ERRNO(res, NO_DATA);
break;
case FORMERR:
case NOTIMP:
case REFUSED:
default:
RES_SET_H_ERRNO(res, 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 = (HEADER *)(void *)target->answer; /*XXX*/
u_int dots;
int trailing_dot, ret, saved_herrno;
int got_nodata = 0, got_servfail = 0, root_on_list = 0;
int tried_as_is = 0;
int searched = 0;
char abuf[MAXDNAME];
errno = 0;
RES_SET_H_ERRNO(res, 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, abuf, sizeof(abuf))) != NULL)
return (res_queryN(cp, target, res));
/*
* If there are enough dots in the name, let's just give it a
* try 'as is'. The threshold can be set with the "ndots" option.
* Also, query 'as is', if there is a trailing dot in the name.
*/
saved_herrno = -1;
if (dots >= res->ndots || trailing_dot) {
ret = res_querydomainN(name, NULL, target, res);
if (ret > 0 || trailing_dot)
return (ret);
if (errno == ECONNREFUSED) {
RES_SET_H_ERRNO(res, TRY_AGAIN);
return (-1);
}
switch (res->res_h_errno) {
case NO_DATA:
case HOST_NOT_FOUND:
break;
case TRY_AGAIN:
if (hp->rcode == SERVFAIL)
break;
/* FALLTHROUGH */
default:
return (-1);
}
saved_herrno = res->res_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++) {
searched = 1;
if (domain[0][0] == '\0' ||
(domain[0][0] == '.' && domain[0][1] == '\0'))
root_on_list++;
if (root_on_list && tried_as_is)
continue;
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) {
RES_SET_H_ERRNO(res, TRY_AGAIN);
return (-1);
}
switch (res->res_h_errno) {
case NO_DATA:
got_nodata++;
/* FALLTHROUGH */
case HOST_NOT_FOUND:
/* keep trying */
break;
case TRY_AGAIN:
got_servfail++;
if (hp->rcode == SERVFAIL) {
/* try next search element, if any */
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++;
}
}
switch (res->res_h_errno) {
case NO_DATA:
case HOST_NOT_FOUND:
break;
case TRY_AGAIN:
if (hp->rcode == SERVFAIL)
break;
/* FALLTHROUGH */
default:
goto giveup;
}
/*
* If the query has not already been tried as is then try it
* unless RES_NOTLDQUERY is set and there were no dots.
*/
if ((dots || !searched || !(res->options & RES_NOTLDQUERY)) &&
!(tried_as_is || root_on_list)) {
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.
*/
giveup:
if (saved_herrno != -1)
RES_SET_H_ERRNO(res, saved_herrno);
else if (got_nodata)
RES_SET_H_ERRNO(res, NO_DATA);
else if (got_servfail)
RES_SET_H_ERRNO(res, 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;
#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 >= MAXDNAME) {
RES_SET_H_ERRNO(res, 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 + d + 1 >= MAXDNAME) {
RES_SET_H_ERRNO(res, NO_RECOVERY);
return (-1);
}
snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
}
return (res_queryN(longname, target, res));
}
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