/* * 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. * * ported from: * FreeBSD: src/lib/libc/net/getaddrinfo.c,v 1.7 2000/02/09 00:38:06 shin Exp * $FreeBSD: ports/security/openssh/files/getaddrinfo.c,v 1.2 2000/04/17 22:20:23 sumikawa Exp $ */ /* * "#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. * Note: * - We use getipnodebyname() just for thread-safeness. There's no intent * to let it do PF_UNSPEC (actually we never pass PF_UNSPEC to * getipnodebyname(). * - The code filters out AFs that are not supported by the kernel, * when globbing NULL hostname (to loopback, or wildcard). Is it the right * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG * in ai_flags? */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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 in6_addrany[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; static const char in_loopback[] = { 127, 0, 0, 1 }; static const char in6_loopback[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }; 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[] = { #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 }, { -1, 0, 0, NULL, 0 }, }; #ifdef INET6 #define PTON_MAX 16 #else #define PTON_MAX 4 #endif static int str_isnumber __P((const char *)); static int explore_fqdn __P((const struct addrinfo *, const char *, const char *, struct addrinfo **)); static int explore_null __P((const struct addrinfo *, const char *, const char *, struct addrinfo **)); static int explore_numeric __P((const struct addrinfo *, const char *, const char *, struct addrinfo **)); static int explore_numeric_scope __P((const struct addrinfo *, const char *, const char *, struct addrinfo **)); static int get_canonname __P((const struct addrinfo *, struct addrinfo *, const char *)); static struct addrinfo *get_ai __P((const struct addrinfo *, const struct afd *, const char *)); static int get_portmatch __P((const struct addrinfo *, const char *)); static int get_port __P((struct addrinfo *, const char *, int)); static const struct afd *find_afd __P((int)); 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 */ "Argument res is NULL", /* EAI_RESNULL */ "Unknown error", /* EAI_MAX */ }; /* XXX macros that make external reference is BAD. */ #define GET_AI(ai, afd, addr) \ do { \ /* external reference: pai, error, and label free */ \ (ai) = get_ai(pai, (afd), (addr)); \ if ((ai) == NULL) { \ error = EAI_MEMORY; \ goto free; \ } \ } while (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 (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 (0) #define ERR(err) \ do { \ /* external reference: error, and label bad */ \ error = (err); \ goto bad; \ } while (0) #define MATCH_FAMILY(x, y, w) \ ((x) == (y) || ((w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) #define MATCH(x, y, w) \ ((x) == (y) || ((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); } while ((ai = next) != NULL); } static int str_isnumber(p) const char *p; { char *q = (char *)p; while (*q) { if (! isdigit(*q)) return NO; q++; } return YES; } 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 afd *afd; const struct explore *ex; sentinel.ai_next = NULL; 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 (res == NULL) return EAI_RESNULL; /* xxx */ 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) { int matched = 0; 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) matched = 1; else continue; if (matched == 0) ERR(EAI_BADHINTS); } } } /* backup original pai contents */ ai0 = *pai; /* * special cases check for inet and inet6 sockets. * (1) servname is disallowed for raw sockets. * (2) numeric servname is disallowed if socktype/protocol is left * unspecified. */ if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) #ifdef INET6 || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) #endif ) { *pai = ai0; if (pai->ai_family == PF_UNSPEC) #ifdef INET6 pai->ai_family = PF_INET6; #else pai->ai_family = PF_INET; #endif error = get_portmatch(pai, servname); if (error) ERR(error); } /* NULL hostname, or numeric hostname */ 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 (hostname == NULL) error = explore_null(pai, hostname, 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_NONAME); /* * hostname as alphabetical name. * we would like to prefer AF_INET6 than AF_INET, so we'll make a * outer loop by AFs. */ for (afd = afdl; afd->a_af; afd++) { *pai = ai0; if (!MATCH_FAMILY(pai->ai_family, afd->a_af, 1)) continue; for (ex = explore; ex->e_af >= 0; ex++) { *pai = ai0; if (pai->ai_family == PF_UNSPEC) pai->ai_family = afd->a_af; 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; error = explore_fqdn(pai, hostname, servname, &cur->ai_next); while (cur && cur->ai_next) cur = cur->ai_next; } } /* XXX: if any addrinfo found, SUCCESS return even if (error != 0) */ if (sentinel.ai_next) { good: *res = sentinel.ai_next; return SUCCESS; } /* else, failed */ free: bad: if (error == 0) error = EAI_FAIL; 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 hostent *hp; int h_error; int af; char *ap; struct addrinfo sentinel, *cur; int i; const struct afd *afd; int error; *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; hp = getipnodebyname(hostname, pai->ai_family, AI_ADDRCONFIG, &h_error); if (hp == NULL) { switch (h_error) { case HOST_NOT_FOUND: case NO_DATA: error = EAI_NODATA; break; case TRY_AGAIN: error = EAI_AGAIN; break; case NO_RECOVERY: case NETDB_INTERNAL: default: error = EAI_FAIL; break; } } else if ((hp->h_name == NULL) || (hp->h_name[0] == 0) || (hp->h_addr_list[0] == NULL)) { freehostent(hp); hp = NULL; error = EAI_FAIL; } if (hp == NULL) goto free; for (i = 0; hp->h_addr_list[i] != NULL; i++) { af = hp->h_addrtype; ap = hp->h_addr_list[i]; if (af != pai->ai_family) continue; GET_AI(cur->ai_next, afd, ap); GET_PORT(cur->ai_next, servname); if ((pai->ai_flags & AI_CANONNAME) != 0) { /* * RFC2553 says that ai_canonname will be set only for * the first element. we do it for all the elements, * just for convenience. */ GET_CANONNAME(cur->ai_next, hp->h_name); } while (cur && cur->ai_next) cur = cur->ai_next; } *res = sentinel.ai_next; return 0; free: if (hp) freehostent(hp); if (sentinel.ai_next) 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(pai, hostname, servname, res) const struct addrinfo *pai; const char *hostname; 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) return 0; close(s); afd = find_afd(pai->ai_family); if (afd == NULL) return 0; GET_AI(cur->ai_next, afd, (pai->ai_flags & AI_PASSIVE) ? afd->a_addrany : afd->a_loopback ); /* xxx meaningless? * GET_CANONNAME(cur->ai_next, "anyaddr"); * or * GET_CANONNAME(cur->ai_next, "localhost"); */ /* if the servname does not match socktype/protocol, ignored */ GET_PORT(cur->ai_next, servname); *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]; int flags; *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; flags = pai->ai_flags; 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*/ } *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; { #ifndef SCOPE_DELIMITER return explore_numeric(pai, hostname, servname, res); #else const struct afd *afd; struct addrinfo *cur; int error; char *cp, *hostname2 = NULL; int scope; #ifdef INET6 struct sockaddr_in6 *sin6; #endif /* * 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'; cp++; switch (pai->ai_family) { #ifdef INET6 case AF_INET6: scope = if_nametoindex(hostname2); if (scope == 0) { error = EAI_SYSTEM; goto free; } break; #endif } error = explore_numeric(pai, cp, servname, res); if (error == 0) { for (cur = *res; cur; cur = cur->ai_next) { #ifdef INET6 if (cur->ai_family != AF_INET6) continue; sin6 = (struct sockaddr_in6 *)cur->ai_addr; if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr) || IN6_IS_ADDR_MC_LINKLOCAL(&sin6->sin6_addr)) sin6->sin6_scope_id = scope; #endif } } #ifdef INET6 free: #endif 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; strcpy(ai->ai_canonname, str); } 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 *)(ai + 1); memset(ai->ai_addr, 0, 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 *)(ai->ai_addr); #ifdef FAITH if (translate == 1) memcpy(p + afd->a_off, &faith_prefix, afd->a_addrlen); else #endif memcpy(p + afd->a_off, addr, 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. */ 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; if (ai->ai_family != AF_INET #ifdef INET6 && ai->ai_family != AF_INET6 #endif ) 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 = htons(atoi(servname)); if (port < 0 || port > 65535) return EAI_SERVICE; } 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 *)ai->ai_addr)->sin_port = port; break; #ifdef INET6 case AF_INET6: ((struct sockaddr_in6 *)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; }