/* $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: * - Thread safe-ness must be checked. * - Return values. There are nonstandard return values defined and used * in the source code. This is because RFC2553 is silent about which error * code must be returned for which situation. * - 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 netbsd/openbsd/freebsd4/bsdi4: * - To avoid search order issue, we have a big amount of code duplicate * from gethnamaddr.c and some other places. The issues that there's no * lower layer function to lookup "IPv4 or IPv6" record. Calling * gethostbyname2 from getaddrinfo will end up in wrong search order, as * presented above. * * OS specific notes for freebsd4: * - FreeBSD supported $GAI. The code does not. * - FreeBSD allowed classful IPv4 numeric (127.1), the code does not. */ #include __FBSDID("$FreeBSD$"); #include "namespace.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "res_config.h" #ifdef DEBUG #include #endif #include #include #include "un-namespace.h" #include "libc_private.h" #if defined(__KAME__) && defined(INET6) # define FAITH #endif #define SUCCESS 0 #define ANY 0 #define YES 1 #define NO 0 static const char in_addrany[] = { 0, 0, 0, 0 }; static const char in_loopback[] = { 127, 0, 0, 1 }; #ifdef INET6 static const char in6_addrany[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; static const char in6_loopback[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }; #endif static const struct afd { int a_af; int a_addrlen; int a_socklen; int a_off; const char *a_addrany; const char *a_loopback; int a_scoped; } afdl [] = { #ifdef INET6 #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; const char *e_protostr; int e_wild; #define WILD_AF(ex) ((ex)->e_wild & 0x01) #define WILD_SOCKTYPE(ex) ((ex)->e_wild & 0x02) #define WILD_PROTOCOL(ex) ((ex)->e_wild & 0x04) }; static const struct explore explore[] = { #if 0 { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, #endif #ifdef INET6 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, #endif { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, { -1, 0, 0, NULL, 0 }, }; #ifdef INET6 #define PTON_MAX 16 #else #define PTON_MAX 4 #endif static const ns_src default_dns_files[] = { { NSSRC_FILES, NS_SUCCESS }, { NSSRC_DNS, NS_SUCCESS }, { 0 } }; #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 */ }; static int str_isnumber(const char *); static int explore_fqdn(const struct addrinfo *, const char *, const char *, struct addrinfo **); static int explore_null(const struct addrinfo *, const char *, struct addrinfo **); static int explore_numeric(const struct addrinfo *, const char *, const char *, struct addrinfo **); static int explore_numeric_scope(const struct addrinfo *, const char *, const char *, struct addrinfo **); static int get_canonname(const struct addrinfo *, struct addrinfo *, const char *); static struct addrinfo *get_ai(const struct addrinfo *, const struct afd *, const char *); static int get_portmatch(const struct addrinfo *, const char *); static int get_port(struct addrinfo *, const char *, int); static const struct afd *find_afd(int); static int addrconfig(struct addrinfo *); #ifdef INET6 static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *); #endif static struct addrinfo *getanswer(const querybuf *, int, const char *, int, const struct addrinfo *); static int _dns_getaddrinfo(void *, void *, va_list); static void _sethtent(void); static void _endhtent(void); static struct addrinfo *_gethtent(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 *); static int res_searchN(const char *, struct res_target *); static int res_querydomainN(const char *, const char *, struct res_target *); static char *ai_errlist[] = { "Success", "Address family for hostname not supported", /* EAI_ADDRFAMILY */ "Temporary failure in name resolution", /* EAI_AGAIN */ "Invalid value for ai_flags", /* EAI_BADFLAGS */ "Non-recoverable failure in name resolution", /* EAI_FAIL */ "ai_family not supported", /* EAI_FAMILY */ "Memory allocation failure", /* EAI_MEMORY */ "No address associated with hostname", /* EAI_NODATA */ "hostname nor servname provided, or not known", /* EAI_NONAME */ "servname not supported for ai_socktype", /* EAI_SERVICE */ "ai_socktype not supported", /* EAI_SOCKTYPE */ "System error returned in errno", /* EAI_SYSTEM */ "Invalid value for hints", /* EAI_BADHINTS */ "Resolved protocol is unknown", /* EAI_PROTOCOL */ "Unknown error", /* EAI_MAX */ }; /* * XXX: Our res_*() is not thread-safe. So, we share lock between * getaddrinfo() and getipnodeby*(). Still, we cannot use * getaddrinfo() and getipnodeby*() in conjunction with other * functions which call res_*(). */ pthread_mutex_t __getaddrinfo_thread_lock = PTHREAD_MUTEX_INITIALIZER; #define THREAD_LOCK() \ if (__isthreaded) _pthread_mutex_lock(&__getaddrinfo_thread_lock); #define THREAD_UNLOCK() \ if (__isthreaded) _pthread_mutex_unlock(&__getaddrinfo_thread_lock); /* 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))) char * gai_strerror(ecode) int ecode; { if (ecode < 0 || ecode > EAI_MAX) ecode = EAI_MAX; return ai_errlist[ecode]; } void freeaddrinfo(ai) 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 str_isnumber(p) const char *p; { char *ep; if (*p == '\0') return NO; ep = NULL; errno = 0; (void)strtoul(p, &ep, 10); if (errno == 0 && ep && *ep == '\0') return YES; else return NO; } int getaddrinfo(hostname, servname, hints, res) const char *hostname, *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; memset(&sentinel, 0, sizeof(sentinel)); cur = &sentinel; pai = &ai; pai->ai_flags = 0; pai->ai_family = PF_UNSPEC; pai->ai_socktype = ANY; pai->ai_protocol = ANY; pai->ai_addrlen = 0; pai->ai_canonname = NULL; pai->ai_addr = NULL; pai->ai_next = NULL; if (hostname == NULL && servname == NULL) return EAI_NONAME; if (hints) { /* error check for hints */ if (hints->ai_addrlen || hints->ai_canonname || hints->ai_addr || hints->ai_next) ERR(EAI_BADHINTS); /* xxx */ if (hints->ai_flags & ~AI_MASK) ERR(EAI_BADFLAGS); switch (hints->ai_family) { case PF_UNSPEC: case PF_INET: #ifdef INET6 case PF_INET6: #endif break; default: ERR(EAI_FAMILY); } memcpy(pai, hints, sizeof(*pai)); /* * if both socktype/protocol are specified, check if they * are meaningful combination. */ if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { for (ex = explore; ex->e_af >= 0; ex++) { if (pai->ai_family != ex->e_af) continue; if (ex->e_socktype == ANY) continue; if (ex->e_protocol == ANY) continue; if (pai->ai_socktype == ex->e_socktype && pai->ai_protocol != ex->e_protocol) { ERR(EAI_BADHINTS); } } } } /* * post-2553: AI_ALL and AI_V4MAPPED are effective only against * AF_INET6 query. They need to be ignored if specified in other * occassions. */ switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { case AI_V4MAPPED: case AI_ALL | AI_V4MAPPED: if (pai->ai_family != AF_INET6) pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); break; case AI_ALL: #if 1 /* illegal */ ERR(EAI_BADFLAGS); #else pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); #endif break; } /* * check for special cases. (1) numeric servname is disallowed if * socktype/protocol are left unspecified. (2) servname is disallowed * for raw and other inet{,6} sockets. */ if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) #ifdef PF_INET6 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) #endif ) { ai0 = *pai; /* backup *pai */ if (pai->ai_family == PF_UNSPEC) { #ifdef PF_INET6 pai->ai_family = PF_INET6; #else pai->ai_family = PF_INET; #endif } error = get_portmatch(pai, servname); if (error) ERR(error); *pai = ai0; } ai0 = *pai; /* NULL hostname, or numeric hostname */ for (ex = explore; ex->e_af >= 0; ex++) { *pai = ai0; /* PF_UNSPEC entries are prepared for DNS queries only */ if (ex->e_af == PF_UNSPEC) continue; if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) continue; if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) continue; if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) continue; if (pai->ai_family == PF_UNSPEC) pai->ai_family = ex->e_af; if (pai->ai_socktype == ANY && ex->e_socktype != ANY) pai->ai_socktype = ex->e_socktype; if (pai->ai_protocol == ANY && ex->e_protocol != ANY) pai->ai_protocol = ex->e_protocol; if (hostname == NULL) error = explore_null(pai, servname, &cur->ai_next); else error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); if (error) goto free; while (cur && cur->ai_next) cur = cur->ai_next; } /* * XXX * If numreic representation of AF1 can be interpreted as FQDN * representation of AF2, we need to think again about the code below. */ if (sentinel.ai_next) goto good; if (pai->ai_flags & AI_NUMERICHOST) ERR(EAI_NONAME); if (hostname == NULL) ERR(EAI_NODATA); if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) ERR(EAI_FAIL); /* * hostname as alphabetical name. * we would like to prefer AF_INET6 than AF_INET, so we'll make a * outer loop by AFs. */ for (ex = explore; ex->e_af >= 0; ex++) { *pai = ai0; /* require exact match for family field */ if (pai->ai_family != ex->e_af) continue; if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) { continue; } if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) { continue; } if (pai->ai_socktype == ANY && ex->e_socktype != ANY) pai->ai_socktype = ex->e_socktype; if (pai->ai_protocol == ANY && ex->e_protocol != ANY) pai->ai_protocol = ex->e_protocol; error = explore_fqdn(pai, hostname, servname, &cur->ai_next); while (cur && cur->ai_next) cur = cur->ai_next; } /* XXX */ if (sentinel.ai_next) error = 0; if (error) goto free; if (error == 0) { if (sentinel.ai_next) { good: *res = sentinel.ai_next; return SUCCESS; } else error = EAI_FAIL; } free: bad: if (sentinel.ai_next) freeaddrinfo(sentinel.ai_next); *res = NULL; return error; } /* * FQDN hostname, DNS lookup */ static int explore_fqdn(pai, hostname, servname, res) const struct addrinfo *pai; const char *hostname; const char *servname; struct addrinfo **res; { struct addrinfo *result; struct addrinfo *cur; int error = 0; static const ns_dtab dtab[] = { NS_FILES_CB(_files_getaddrinfo, NULL) { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ NS_NIS_CB(_yp_getaddrinfo, NULL) { 0 } }; result = NULL; THREAD_LOCK(); /* * if the servname does not match socktype/protocol, ignore it. */ if (get_portmatch(pai, servname) != 0) { THREAD_UNLOCK(); return 0; } switch (_nsdispatch(&result, dtab, NSDB_HOSTS, "getaddrinfo", default_dns_files, hostname, pai)) { case NS_TRYAGAIN: error = EAI_AGAIN; goto free; case NS_UNAVAIL: error = EAI_FAIL; goto free; case NS_NOTFOUND: error = EAI_NODATA; goto free; case NS_SUCCESS: error = 0; for (cur = result; cur; cur = cur->ai_next) { GET_PORT(cur, servname); /* canonname should be filled already */ } break; } THREAD_UNLOCK(); *res = result; return 0; free: THREAD_UNLOCK(); 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(pai, servname, res) const struct addrinfo *pai; const char *servname; struct addrinfo **res; { int s; const struct afd *afd; struct addrinfo *cur; struct addrinfo sentinel; int error; *res = NULL; sentinel.ai_next = NULL; cur = &sentinel; /* * filter out AFs that are not supported by the kernel * XXX errno? */ s = _socket(pai->ai_family, SOCK_DGRAM, 0); if (s < 0) { if (errno != EMFILE) return 0; } else _close(s); /* * if the servname does not match socktype/protocol, ignore it. */ if (get_portmatch(pai, servname) != 0) return 0; afd = find_afd(pai->ai_family); if (afd == NULL) return 0; if (pai->ai_flags & AI_PASSIVE) { GET_AI(cur->ai_next, afd, afd->a_addrany); /* xxx meaningless? * GET_CANONNAME(cur->ai_next, "anyaddr"); */ GET_PORT(cur->ai_next, servname); } else { GET_AI(cur->ai_next, afd, afd->a_loopback); /* xxx meaningless? * GET_CANONNAME(cur->ai_next, "localhost"); */ GET_PORT(cur->ai_next, servname); } cur = cur->ai_next; *res = sentinel.ai_next; return 0; free: if (sentinel.ai_next) freeaddrinfo(sentinel.ai_next); return error; } /* * numeric hostname */ static int explore_numeric(pai, hostname, servname, res) const struct addrinfo *pai; const char *hostname; const char *servname; struct addrinfo **res; { const struct afd *afd; struct addrinfo *cur; struct addrinfo sentinel; int error; char pton[PTON_MAX]; *res = NULL; sentinel.ai_next = NULL; cur = &sentinel; /* * if the servname does not match socktype/protocol, ignore it. */ if (get_portmatch(pai, servname) != 0) return 0; afd = find_afd(pai->ai_family); if (afd == NULL) return 0; switch (afd->a_af) { #if 1 /*X/Open spec*/ case AF_INET: if (inet_aton(hostname, (struct in_addr *)pton) == 1) { if (pai->ai_family == afd->a_af || pai->ai_family == PF_UNSPEC /*?*/) { GET_AI(cur->ai_next, afd, pton); GET_PORT(cur->ai_next, servname); while (cur && cur->ai_next) cur = cur->ai_next; } else ERR(EAI_FAMILY); /*xxx*/ } break; #endif default: if (inet_pton(afd->a_af, hostname, pton) == 1) { if (pai->ai_family == afd->a_af || pai->ai_family == PF_UNSPEC /*?*/) { GET_AI(cur->ai_next, afd, pton); GET_PORT(cur->ai_next, servname); while (cur && 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(pai, hostname, servname, res) 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); #else const struct afd *afd; struct addrinfo *cur; int error; char *cp, *hostname2 = NULL, *scope, *addr; struct sockaddr_in6 *sin6; /* * if the servname does not match socktype/protocol, ignore it. */ if (get_portmatch(pai, servname) != 0) return 0; afd = find_afd(pai->ai_family); if (afd == NULL) return 0; if (!afd->a_scoped) return explore_numeric(pai, hostname, servname, res); cp = strchr(hostname, SCOPE_DELIMITER); if (cp == NULL) return explore_numeric(pai, hostname, servname, res); /* * Handle special case of */ 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); 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(pai, ai, str) const struct addrinfo *pai; struct addrinfo *ai; const char *str; { if ((pai->ai_flags & AI_CANONNAME) != 0) { ai->ai_canonname = (char *)malloc(strlen(str) + 1); if (ai->ai_canonname == NULL) return EAI_MEMORY; strlcpy(ai->ai_canonname, str, strlen(str) + 1); } return 0; } static struct addrinfo * get_ai(pai, afd, addr) 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; } static int get_portmatch(ai, servname) 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(ai, servname, matchonly) struct addrinfo *ai; const char *servname; int matchonly; { const char *proto; struct servent *sp; int port; 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: allownumeric = 1; break; case ANY: allownumeric = 0; break; default: return EAI_SOCKTYPE; } if (str_isnumber(servname)) { if (!allownumeric) return EAI_SERVICE; port = atoi(servname); if (port < 0 || port > 65535) return EAI_SERVICE; port = htons(port); } else { switch (ai->ai_socktype) { case SOCK_DGRAM: proto = "udp"; break; case SOCK_STREAM: proto = "tcp"; break; default: proto = NULL; break; } if ((sp = getservbyname(servname, proto)) == NULL) return EAI_SERVICE; port = sp->s_port; } if (!matchonly) { switch (ai->ai_family) { case AF_INET: ((struct sockaddr_in *)(void *) ai->ai_addr)->sin_port = port; break; #ifdef INET6 case AF_INET6: ((struct sockaddr_in6 *)(void *) ai->ai_addr)->sin6_port = port; break; #endif } } return 0; } static const struct afd * find_afd(af) 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(pai) 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, 0)) < 0) af = AF_INET; else { _close(s); if ((s = _socket(AF_INET, SOCK_DGRAM, 0)) < 0) af = AF_INET6; else _close(s); } } if (af != AF_UNSPEC) { if ((s = _socket(af, SOCK_DGRAM, 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(scope, sin6, scopeid) 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)) { /* * 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 RESOLVSORT struct addr_ptr { struct addrinfo *ai; int aval; }; static int addr4sort(struct addrinfo *sentinel) { 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*/ #ifdef DEBUG static const char AskedForGot[] = "gethostby*.getanswer: asked for \"%s\", got \"%s\""; #endif static FILE *hostf = NULL; static struct addrinfo * getanswer(answer, anslen, qname, qtype, pai) const querybuf *answer; int anslen; const char *qname; int qtype; const struct addrinfo *pai; { struct addrinfo sentinel, *cur; struct addrinfo ai; const struct afd *afd; char *canonname; const HEADER *hp; const u_char *cp; int n; const u_char *eom; char *bp, *ep; int type, class, ancount, qdcount; int haveanswer, had_error; char tbuf[MAXDNAME]; int (*name_ok)(const char *); char hostbuf[8*1024]; memset(&sentinel, 0, sizeof(sentinel)); cur = &sentinel; canonname = NULL; eom = answer->buf + anslen; switch (qtype) { case T_A: case T_AAAA: case T_ANY: /*use T_ANY only for T_A/T_AAAA lookup*/ name_ok = res_hnok; break; default: return (NULL); /* XXX should be abort(); */ } /* * find first satisfactory answer */ hp = &answer->hdr; ancount = ntohs(hp->ancount); qdcount = ntohs(hp->qdcount); bp = hostbuf; ep = hostbuf + sizeof hostbuf; cp = answer->buf + HFIXEDSZ; if (qdcount != 1) { h_errno = NO_RECOVERY; return (NULL); } n = dn_expand(answer->buf, eom, cp, bp, ep - bp); if ((n < 0) || !(*name_ok)(bp)) { h_errno = NO_RECOVERY; return (NULL); } cp += n + QFIXEDSZ; if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { /* res_send() has already verified that the query name is the * same as the one we sent; this just gets the expanded name * (i.e., with the succeeding search-domain tacked on). */ n = strlen(bp) + 1; /* for the \0 */ if (n >= MAXHOSTNAMELEN) { h_errno = NO_RECOVERY; return (NULL); } canonname = bp; bp += n; /* The qname can be abbreviated, but h_name is now absolute. */ qname = canonname; } haveanswer = 0; had_error = 0; while (ancount-- > 0 && cp < eom && !had_error) { n = dn_expand(answer->buf, eom, cp, bp, ep - bp); if ((n < 0) || !(*name_ok)(bp)) { had_error++; continue; } cp += n; /* name */ type = _getshort(cp); cp += INT16SZ; /* type */ class = _getshort(cp); cp += INT16SZ + INT32SZ; /* class, TTL */ n = _getshort(cp); cp += INT16SZ; /* len */ if (class != C_IN) { /* XXX - debug? syslog? */ cp += n; continue; /* XXX - had_error++ ? */ } if ((qtype == T_A || qtype == T_AAAA || qtype == T_ANY) && type == T_CNAME) { n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); if ((n < 0) || !(*name_ok)(tbuf)) { had_error++; continue; } cp += n; /* Get canonical name. */ n = strlen(tbuf) + 1; /* for the \0 */ if (n > ep - bp || n >= MAXHOSTNAMELEN) { had_error++; continue; } strlcpy(bp, tbuf, 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) 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) < 0) { freeaddrinfo(sentinel.ai_next); h_errno = 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); h_errno = NETDB_SUCCESS; return sentinel.ai_next; } h_errno = NO_RECOVERY; return NULL; } /*ARGSUSED*/ static int _dns_getaddrinfo(rv, cb_data, ap) void *rv; void *cb_data; va_list ap; { struct addrinfo *ai; querybuf *buf, *buf2; const char *name; const struct addrinfo *pai; struct addrinfo sentinel, *cur; struct res_target q, q2; name = va_arg(ap, char *); pai = va_arg(ap, const struct addrinfo *); memset(&q, 0, sizeof(q2)); memset(&q2, 0, sizeof(q2)); memset(&sentinel, 0, sizeof(sentinel)); cur = &sentinel; buf = malloc(sizeof(*buf)); if (!buf) { h_errno = NETDB_INTERNAL; return NS_NOTFOUND; } buf2 = malloc(sizeof(*buf2)); if (!buf2) { free(buf); h_errno = NETDB_INTERNAL; return NS_NOTFOUND; } switch (pai->ai_family) { case AF_UNSPEC: /* prefer IPv6 */ q.name = name; q.qclass = C_IN; q.qtype = T_AAAA; q.answer = buf->buf; q.anslen = sizeof(buf->buf); q.next = &q2; q2.name = name; q2.qclass = C_IN; q2.qtype = T_A; q2.answer = buf2->buf; q2.anslen = sizeof(buf2->buf); break; case AF_INET: q.name = name; q.qclass = C_IN; q.qtype = T_A; q.answer = buf->buf; q.anslen = sizeof(buf->buf); break; case AF_INET6: q.name = name; q.qclass = C_IN; q.qtype = T_AAAA; q.answer = buf->buf; q.anslen = sizeof(buf->buf); break; default: free(buf); free(buf2); return NS_UNAVAIL; } if (res_searchN(name, &q) < 0) { free(buf); free(buf2); return NS_NOTFOUND; } ai = getanswer(buf, q.n, q.name, q.qtype, pai); if (ai) { cur->ai_next = ai; while (cur && cur->ai_next) cur = cur->ai_next; } if (q.next) { ai = getanswer(buf2, q2.n, q2.name, q2.qtype, pai); if (ai) cur->ai_next = ai; } free(buf); free(buf2); if (sentinel.ai_next == NULL) switch (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() { if (!hostf) hostf = fopen(_PATH_HOSTS, "r" ); else rewind(hostf); } static void _endhtent() { if (hostf) { (void) fclose(hostf); hostf = NULL; } } static struct addrinfo * _gethtent(name, pai) 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, "r" ))) return (NULL); again: if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) return (NULL); if (*p == '#') goto again; if (!(cp = strpbrk(p, "#\n"))) goto again; *cp = '\0'; if (!(cp = strpbrk(p, " \t"))) goto again; *cp++ = '\0'; addr = p; 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(rv, cb_data, ap) void *rv; void *cb_data; va_list ap; { const char *name; const struct addrinfo *pai; struct addrinfo sentinel, *cur; struct addrinfo *p; name = va_arg(ap, char *); pai = va_arg(ap, struct addrinfo *); memset(&sentinel, 0, sizeof(sentinel)); cur = &sentinel; _sethtent(); while ((p = _gethtent(name, pai)) != NULL) { cur->ai_next = p; while (cur && cur->ai_next) cur = cur->ai_next; } _endhtent(); *((struct addrinfo **)rv) = sentinel.ai_next; if (sentinel.ai_next == NULL) return NS_NOTFOUND; return NS_SUCCESS; } #ifdef YP static char *__ypdomain; /*ARGSUSED*/ static struct addrinfo * _yphostent(line, pai) 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(rv, cb_data, ap) void *rv; void *cb_data; va_list ap; { struct addrinfo sentinel, *cur; struct addrinfo *ai = NULL; static char *__ypcurrent; int __ypcurrentlen, r; const char *name; const struct addrinfo *pai; name = va_arg(ap, char *); pai = va_arg(ap, const struct addrinfo *); memset(&sentinel, 0, sizeof(sentinel)); cur = &sentinel; if (!__ypdomain) { if (_yp_check(&__ypdomain) == 0) return NS_UNAVAIL; } if (__ypcurrent) free(__ypcurrent); __ypcurrent = NULL; /* 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), &__ypcurrent, &__ypcurrentlen); if (r == 0) { struct addrinfo ai4; ai4 = *pai; ai4.ai_family = AF_INET; ai = _yphostent(__ypcurrent, &ai4); if (ai) { cur->ai_next = ai; while (cur && cur->ai_next) cur = cur->ai_next; } } } /* ipnodes.byname can hold both IPv4/v6 */ r = yp_match(__ypdomain, "ipnodes.byname", name, (int)strlen(name), &__ypcurrent, &__ypcurrentlen); if (r == 0) { ai = _yphostent(__ypcurrent, pai); if (ai) { cur->ai_next = ai; while (cur && cur->ai_next) cur = cur->ai_next; } } 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 */ extern const char *__hostalias(const char *); extern int h_errno; /* * 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(name, target) const char *name; /* domain name */ struct res_target *target; { u_char *buf; HEADER *hp; int n; struct res_target *t; int rcode; int ancount; rcode = NOERROR; ancount = 0; if ((_res.options & RES_INIT) == 0 && res_init() == -1) { h_errno = NETDB_INTERNAL; return (-1); } buf = malloc(MAXPACKET); if (!buf) { h_errno = NETDB_INTERNAL; return -1; } for (t = target; t; t = t->next) { int class, type; u_char *answer; int anslen; hp = (HEADER *)(void *)t->answer; hp->rcode = NOERROR; /* default */ /* make it easier... */ class = t->qclass; type = t->qtype; answer = t->answer; anslen = t->anslen; #ifdef DEBUG if (_res.options & RES_DEBUG) printf(";; res_query(%s, %d, %d)\n", name, class, type); #endif n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, buf, MAXPACKET); if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) n = res_opt(n, buf, MAXPACKET, anslen); if (n <= 0) { #ifdef DEBUG if (_res.options & RES_DEBUG) printf(";; res_query: mkquery failed\n"); #endif free(buf); h_errno = NO_RECOVERY; return (n); } n = res_send(buf, n, answer, anslen); #if 0 if (n < 0) { #ifdef DEBUG if (_res.options & RES_DEBUG) printf(";; res_query: send error\n"); #endif free(buf); h_errno = TRY_AGAIN; return (n); } #endif if (n < 0 || 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: 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(name, target) const char *name; /* domain name */ struct res_target *target; { 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, tried_as_is = 0; if ((_res.options & RES_INIT) == 0 && res_init() == -1) { h_errno = NETDB_INTERNAL; return (-1); } 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 = __hostalias(name)) != NULL) return (res_queryN(cp, target)); /* * 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); 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); 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 && (dots || !(_res.options & RES_NOTLDQUERY))) { ret = res_querydomainN(name, NULL, target); 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(name, domain, target) const char *name, *domain; struct res_target *target; { char nbuf[MAXDNAME]; const char *longname = nbuf; size_t n, d; if ((_res.options & RES_INIT) == 0 && res_init() == -1) { h_errno = NETDB_INTERNAL; return (-1); } #ifdef DEBUG if (_res.options & RES_DEBUG) printf(";; res_querydomain(%s, %s)\n", name, domain?domain:""); #endif if (domain == NULL) { /* * Check for trailing '.'; * copy without '.' if present. */ n = strlen(name); if (n >= MAXDNAME) { 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 + d + 1 >= MAXDNAME) { h_errno = NO_RECOVERY; return (-1); } snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain); } return (res_queryN(longname, target)); }