/* $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. */ /* * 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 accepts NULL to be compatible with other OSes. * * 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 $GAI. The code does not. */ #include __FBSDID("$FreeBSD$"); #include "namespace.h" #include #include #include #include #include #include #include #ifdef INET6 #include #include #include #include #endif #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 "netdb_private.h" #include "libc_private.h" #ifdef NS_CACHING #include "nscache.h" #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 #define N_LOCAL 2 #else #define N_INET 0 #define N_LOCAL 1 #endif {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), offsetof(struct sockaddr_in, sin_addr), in_addrany, in_loopback, 0}, #define sizeofmember(type, member) (sizeof(((type *)0)->member)) {PF_LOCAL, sizeofmember(struct sockaddr_un, sun_path), sizeof(struct sockaddr_un), offsetof(struct sockaddr_un, sun_path), NULL, NULL, 0}, {0, 0, 0, 0, NULL, NULL, 0}, }; struct explore { int e_af; int e_socktype; int e_protocol; int e_wild; #define AF_ANY 0x01 #define SOCKTYPE_ANY 0x02 #define PROTOCOL_ANY 0x04 #define WILD_AF(ex) ((ex)->e_wild & AF_ANY) #define WILD_SOCKTYPE(ex) ((ex)->e_wild & SOCKTYPE_ANY) #define WILD_PROTOCOL(ex) ((ex)->e_wild & PROTOCOL_ANY) }; static const struct explore explore[] = { #ifdef INET6 { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_INET6, SOCK_STREAM, IPPROTO_TCP, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_INET6, SOCK_STREAM, IPPROTO_SCTP, AF_ANY | SOCKTYPE_ANY }, { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_INET6, SOCK_DGRAM, IPPROTO_UDPLITE, AF_ANY | SOCKTYPE_ANY }, { PF_INET6, SOCK_RAW, ANY, AF_ANY | PROTOCOL_ANY }, #endif { PF_INET, SOCK_DGRAM, IPPROTO_UDP, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_INET, SOCK_STREAM, IPPROTO_TCP, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_INET, SOCK_STREAM, IPPROTO_SCTP, AF_ANY | SOCKTYPE_ANY }, { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE, AF_ANY | SOCKTYPE_ANY }, { PF_INET, SOCK_RAW, ANY, AF_ANY | PROTOCOL_ANY }, { PF_LOCAL, SOCK_DGRAM, ANY, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_LOCAL, SOCK_STREAM, ANY, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { PF_LOCAL, SOCK_SEQPACKET, ANY, AF_ANY | SOCKTYPE_ANY | PROTOCOL_ANY }, { -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; int aio_initial_sequence; }; 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 *); #ifdef INET6 static int is_ifdisabled(char *); #endif 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; while (ai != NULL) { next = ai->ai_next; free(ai->ai_canonname); /* no need to free(ai->ai_addr) */ free(ai); ai = next; } } 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[nitems(afdl)]; 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_LOCAL: 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); } } /* * RFC 3493: AI_ALL and AI_V4MAPPED are effective only against * AF_INET6 query. They need to be ignored if specified in other * occasions. */ switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { case AI_V4MAPPED: case AI_ALL | AI_V4MAPPED: #ifdef INET6 if (pai->ai_family != AF_INET6) pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); break; #endif case AI_ALL: pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); 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) 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 = calloc(n, sizeof(*aio))) == NULL) return(n); /* give up reordering */ /* 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); aio[i].aio_initial_sequence = i; } /* 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, nitems(mib), NULL, &l, NULL, 0) < 0) return (0); if (l == 0) return (0); if ((buf = malloc(l)) == NULL) return (0); if (sysctl(mib, nitems(mib), 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); _map_v4v6_address( (char *)&((struct sockaddr_in *)addr)->sin_addr, (char *)&key.sin6_addr); 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 */ #ifdef INET6 if (ai.ai_family == AF_INET6) { struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)ai.ai_addr; int off = 0; if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) (void)_setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&off, sizeof(off)); } #endif 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 & 0x80) == 0) { match++; r <<= 1; } break; } else match += 8; return(match); } static int comp_dst(const void *arg1, const void *arg2) { const struct ai_order *dst1 = arg1, *dst2 = arg2; /* * Rule 1: Avoid unusable destinations. * XXX: we currently do not consider if an appropriate route exists. */ if (dst1->aio_srcsa.sa_family != AF_UNSPEC && dst2->aio_srcsa.sa_family == AF_UNSPEC) { return(-1); } if (dst1->aio_srcsa.sa_family == AF_UNSPEC && dst2->aio_srcsa.sa_family != AF_UNSPEC) { return(1); } /* Rule 2: Prefer matching scope. */ if (dst1->aio_dstscope == dst1->aio_srcscope && dst2->aio_dstscope != dst2->aio_srcscope) { return(-1); } if (dst1->aio_dstscope != dst1->aio_srcscope && dst2->aio_dstscope == dst2->aio_srcscope) { return(1); } /* Rule 3: Avoid deprecated addresses. */ if (dst1->aio_srcsa.sa_family != AF_UNSPEC && dst2->aio_srcsa.sa_family != AF_UNSPEC) { if (!(dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && (dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { return(-1); } if ((dst1->aio_srcflag & AIO_SRCFLAG_DEPRECATED) && !(dst2->aio_srcflag & AIO_SRCFLAG_DEPRECATED)) { return(1); } } /* Rule 4: Prefer home addresses. */ /* XXX: not implemented yet */ /* Rule 5: Prefer matching label. */ #ifdef INET6 if (dst1->aio_srcpolicy && dst1->aio_dstpolicy && dst1->aio_srcpolicy->pc_policy.label == dst1->aio_dstpolicy->pc_policy.label && (dst2->aio_srcpolicy == NULL || dst2->aio_dstpolicy == NULL || dst2->aio_srcpolicy->pc_policy.label != dst2->aio_dstpolicy->pc_policy.label)) { return(-1); } if (dst2->aio_srcpolicy && dst2->aio_dstpolicy && dst2->aio_srcpolicy->pc_policy.label == dst2->aio_dstpolicy->pc_policy.label && (dst1->aio_srcpolicy == NULL || dst1->aio_dstpolicy == NULL || dst1->aio_srcpolicy->pc_policy.label != dst1->aio_dstpolicy->pc_policy.label)) { return(1); } #endif /* Rule 6: Prefer higher precedence. */ #ifdef INET6 if (dst1->aio_dstpolicy && (dst2->aio_dstpolicy == NULL || dst1->aio_dstpolicy->pc_policy.preced > dst2->aio_dstpolicy->pc_policy.preced)) { return(-1); } if (dst2->aio_dstpolicy && (dst1->aio_dstpolicy == NULL || dst2->aio_dstpolicy->pc_policy.preced > dst1->aio_dstpolicy->pc_policy.preced)) { return(1); } #endif /* Rule 7: Prefer native transport. */ /* XXX: not implemented yet */ /* Rule 8: Prefer smaller scope. */ if (dst1->aio_dstscope >= 0 && dst1->aio_dstscope < dst2->aio_dstscope) { return(-1); } if (dst2->aio_dstscope >= 0 && dst2->aio_dstscope < dst1->aio_dstscope) { return(1); } /* * Rule 9: Use longest matching prefix. * We compare the match length in a same AF only. */ if (dst1->aio_ai->ai_addr->sa_family == dst2->aio_ai->ai_addr->sa_family && dst1->aio_ai->ai_addr->sa_family != AF_INET) { if (dst1->aio_matchlen > dst2->aio_matchlen) { return(-1); } if (dst1->aio_matchlen < dst2->aio_matchlen) { return(1); } } /* Rule 10: Otherwise, leave the order unchanged. */ /* * Note that qsort is unstable; so, we can't return zero and * expect the order to be unchanged. * That also means we can't depend on the current position of * dst2 being after dst1. We must enforce the initial order * with an explicit compare on the original position. * The qsort specification requires that "When the same objects * (consisting of width bytes, irrespective of their current * positions in the array) are passed more than once to the * comparison function, the results shall be consistent with one * another." * In other words, If A < B, then we must also return B > A. */ if (dst2->aio_initial_sequence < dst1->aio_initial_sequence) return(1); 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; if (pai->ai_family == PF_LOCAL) return (0); /* * 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, ai0; int error; char pton[PTON_MAX], path[PATH_MAX], *p; #ifdef CTASSERT CTASSERT(sizeofmember(struct sockaddr_un, sun_path) <= PATH_MAX); #endif *res = NULL; ai = NULL; afd = find_afd(pai->ai_family); if (afd == NULL) return 0; switch (afd->a_af) { case AF_LOCAL: if (hostname[0] != '/') ERR(EAI_NONAME); if (strlen(hostname) > afd->a_addrlen) ERR(EAI_MEMORY); /* NUL-termination does not need to be guaranteed. */ strncpy(path, hostname, afd->a_addrlen); p = &path[0]; break; 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; p = pton; break; default: if (inet_pton(afd->a_af, hostname, pton) != 1) { if (pai->ai_family != AF_INET6 || (pai->ai_flags & AI_V4MAPPED) != AI_V4MAPPED) return 0; if (inet_aton(hostname, (struct in_addr *)pton) != 1) return 0; afd = &afdl[N_INET]; ai0 = *pai; ai0.ai_family = AF_INET; pai = &ai0; } p = pton; break; } if (pai->ai_family == afd->a_af) { GET_AI(ai, afd, p); GET_PORT(ai, servname); if ((pai->ai_family == AF_INET || pai->ai_family == AF_INET6) && (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 */ 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 INET6 struct in6_addr mapaddr; if (afd->a_af == AF_INET && (pai->ai_flags & AI_V4MAPPED) != 0) { afd = &afdl[N_INET6]; _map_v4v6_address(addr, (char *)&mapaddr); addr = (char *)&mapaddr; } #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; if (ai->ai_family == PF_LOCAL) { size_t n = strnlen(addr, afd->a_addrlen); ai->ai_addrlen -= afd->a_addrlen - n; ai->ai_addr->sa_len -= afd->a_addrlen - n; } ai->ai_addr->sa_family = ai->ai_family = afd->a_af; p = (char *)(void *)(ai->ai_addr); memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); return ai; } /* 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 = calloc(1, l)) == NULL) return NULL; 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_LOCAL: /* AF_LOCAL ignores servname silently. */ return (0); 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; case IPPROTO_UDPLITE: proto = "udplite"; 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; } /* * RFC 3493: AI_ADDRCONFIG check. Determines which address families are * configured on the local system and correlates with pai->ai_family value. * If an address family is not configured on the system, it will not be * queried for. For this purpose, loopback addresses are not considered * configured addresses. * * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with * _dns_getaddrinfo. */ static int addrconfig(struct addrinfo *pai) { struct ifaddrs *ifaddrs, *ifa; struct sockaddr_in *sin; #ifdef INET6 struct sockaddr_in6 *sin6; #endif int seen_inet = 0, seen_inet6 = 0; if (getifaddrs(&ifaddrs) != 0) return (0); for (ifa = ifaddrs; ifa != NULL; ifa = ifa->ifa_next) { if (ifa->ifa_addr == NULL || (ifa->ifa_flags & IFF_UP) == 0) continue; switch (ifa->ifa_addr->sa_family) { case AF_INET: if (seen_inet) continue; sin = (struct sockaddr_in *)(ifa->ifa_addr); if (htonl(sin->sin_addr.s_addr) == INADDR_LOOPBACK) continue; seen_inet = 1; break; #ifdef INET6 case AF_INET6: if (seen_inet6) continue; sin6 = (struct sockaddr_in6 *)(ifa->ifa_addr); if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) continue; if ((ifa->ifa_flags & IFT_LOOP) != 0 && IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) continue; if (is_ifdisabled(ifa->ifa_name)) continue; seen_inet6 = 1; break; #endif } } freeifaddrs(ifaddrs); switch(pai->ai_family) { case AF_INET6: return (seen_inet6); case AF_INET: return (seen_inet); case AF_UNSPEC: if (seen_inet == seen_inet6) return (seen_inet); pai->ai_family = seen_inet ? AF_INET : AF_INET6; return (1); } return (1); } #ifdef INET6 static int is_ifdisabled(char *name) { struct in6_ndireq nd; int fd; if ((fd = _socket(AF_INET6, SOCK_DGRAM | SOCK_CLOEXEC, 0)) < 0) return (-1); memset(&nd, 0, sizeof(nd)); strlcpy(nd.ifname, name, sizeof(nd.ifname)); if (_ioctl(fd, SIOCGIFINFO_IN6, &nd) < 0) { _close(fd); return (-1); } _close(fd); return ((nd.ndi.flags & ND6_IFF_IFDISABLED) != 0); } /* 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 = calloc(1, 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 = calloc(1, 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; } /* * We could have walked a CNAME chain, but the ultimate target * may not have what we looked for. */ RES_SET_H_ERRNO(res, ntohs(hp->ancount) > 0 ? NO_DATA : 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, ai0; querybuf *buf, *buf2; const char *hostname; const struct addrinfo *pai; struct addrinfo sentinel, *cur; struct res_target q, q2; res_state res; ai = NULL; 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; res = __res_state(); 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; } if (pai->ai_family == AF_INET6 && (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) { ai0 = *pai; ai0.ai_family = AF_UNSPEC; pai = &ai0; } 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; } 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 != NULL) { cur->ai_next = ai; while (cur && cur->ai_next) cur = cur->ai_next; } } if (ai == NULL || pai->ai_family != AF_UNSPEC || (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) != AI_V4MAPPED) { ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); if (ai != NULL) cur->ai_next = ai; } free(buf); free(buf2); if (sentinel.ai_next == NULL) switch (res->res_h_errno) { case HOST_NOT_FOUND: case NO_DATA: 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; if (pai->ai_family == AF_INET6 && (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) hints.ai_flags |= AI_V4MAPPED; 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; } static struct addrinfo * _getht(FILE **hostf, const char *name, const struct addrinfo *pai, struct addrinfo *cur) { struct addrinfo *p; while ((p = _gethtent(hostf, name, pai)) != NULL) { cur->ai_next = p; while (cur && cur->ai_next) cur = cur->ai_next; } return (cur); } /*ARGSUSED*/ static int _files_getaddrinfo(void *rv, void *cb_data, va_list ap) { const char *name; const struct addrinfo *pai; struct addrinfo sentinel, *cur; FILE *hostf = NULL; name = va_arg(ap, char *); pai = va_arg(ap, struct addrinfo *); memset(&sentinel, 0, sizeof(sentinel)); cur = &sentinel; _sethtent(&hostf); if (pai->ai_family == AF_INET6 && (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) == AI_V4MAPPED) { struct addrinfo ai0 = *pai; ai0.ai_flags &= ~AI_V4MAPPED; cur = _getht(&hostf, name, &ai0, cur); if (sentinel.ai_next == NULL) { _sethtent(&hostf); ai0.ai_flags |= AI_V4MAPPED; cur = _getht(&hostf, name, &ai0, cur); } } else cur = _getht(&hostf, name, pai, cur); _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; if (pai->ai_family == AF_INET6 && (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) hints.ai_flags |= AI_V4MAPPED; 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; /* 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; while (cur && cur->ai_next) cur = cur->ai_next; } free(ypbuf); } if (ai != NULL) { struct sockaddr_in6 *sin6; switch (ai->ai_family) { case AF_INET: goto done; case AF_INET6: sin6 = (struct sockaddr_in6 *)ai->ai_addr; if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) goto done; break; } } /* hosts.byname is only for IPv4 (Solaris8) */ if (pai->ai_family == AF_UNSPEC || pai->ai_family == AF_INET || ((pai->ai_family == AF_INET6 && (pai->ai_flags & AI_V4MAPPED) == AI_V4MAPPED) && (ai == NULL || (pai->ai_flags & AI_ALL) == AI_ALL))) { r = yp_match(ypdomain, "hosts.byname", name, (int)strlen(name), &ypbuf, &ypbuflen); if (r == 0) { struct addrinfo ai4; ai4 = *pai; if (pai->ai_family == AF_UNSPEC) 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); } } done: 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:""); #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)); }