/* * Copyright (C) 2004-2007 Internet Systems Consortium, Inc. ("ISC") * Copyright (C) 1999-2001 Internet Software Consortium. * * This code is derived from software contributed to ISC by * Berkeley Software Design, Inc. * * Permission to use, copy, modify, and/or distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC AND BERKELEY SOFTWARE DESIGN, INC. * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE * FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR * IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* $ISC: getaddrinfo.c,v 1.43.18.8 2007/09/13 23:46:26 tbox Exp $ */ /*! \file */ /** * lwres_getaddrinfo() is used to get a list of IP addresses and port * numbers for host hostname and service servname. The function is the * lightweight resolver's implementation of getaddrinfo() as defined in * RFC2133. hostname and servname are pointers to null-terminated strings * or NULL. hostname is either a host name or a numeric host address * string: a dotted decimal IPv4 address or an IPv6 address. servname is * either a decimal port number or a service name as listed in * /etc/services. * * If the operating system does not provide a struct addrinfo, the * following structure is used: * * \code * struct addrinfo { * int ai_flags; // AI_PASSIVE, AI_CANONNAME * int ai_family; // PF_xxx * int ai_socktype; // SOCK_xxx * int ai_protocol; // 0 or IPPROTO_xxx for IPv4 and IPv6 * size_t ai_addrlen; // length of ai_addr * char *ai_canonname; // canonical name for hostname * struct sockaddr *ai_addr; // binary address * struct addrinfo *ai_next; // next structure in linked list * }; * \endcode * * * hints is an optional pointer to a struct addrinfo. This structure can * be used to provide hints concerning the type of socket that the caller * supports or wishes to use. The caller can supply the following * structure elements in *hints: * * * * All other elements of the struct addrinfo passed via hints must be * zero. * * A hints of NULL is treated as if the caller provided a struct addrinfo * initialized to zero with ai_familyset to PF_UNSPEC. * * After a successful call to lwres_getaddrinfo(), *res is a pointer to a * linked list of one or more addrinfo structures. Each struct addrinfo * in this list cn be processed by following the ai_next pointer, until a * NULL pointer is encountered. The three members ai_family, ai_socktype, * and ai_protocol in each returned addrinfo structure contain the * corresponding arguments for a call to socket(2). For each addrinfo * structure in the list, the ai_addr member points to a filled-in socket * address structure of length ai_addrlen. * * All of the information returned by lwres_getaddrinfo() is dynamically * allocated: the addrinfo structures, and the socket address structures * and canonical host name strings pointed to by the addrinfostructures. * Memory allocated for the dynamically allocated structures created by a * successful call to lwres_getaddrinfo() is released by * lwres_freeaddrinfo(). ai is a pointer to a struct addrinfo created by * a call to lwres_getaddrinfo(). * * \section lwresreturn RETURN VALUES * * lwres_getaddrinfo() returns zero on success or one of the error codes * listed in gai_strerror() if an error occurs. If both hostname and * servname are NULL lwres_getaddrinfo() returns #EAI_NONAME. * * \section lwressee SEE ALSO * * lwres(3), lwres_getaddrinfo(), lwres_freeaddrinfo(), * lwres_gai_strerror(), RFC2133, getservbyname(3), connect(2), * sendto(2), sendmsg(2), socket(2). */ #include #include #include #include #include #include #include #define SA(addr) ((struct sockaddr *)(addr)) #define SIN(addr) ((struct sockaddr_in *)(addr)) #define SIN6(addr) ((struct sockaddr_in6 *)(addr)) #define SUN(addr) ((struct sockaddr_un *)(addr)) /*! \struct addrinfo */ static struct addrinfo *ai_reverse(struct addrinfo *oai), *ai_clone(struct addrinfo *oai, int family), *ai_alloc(int family, int addrlen); #ifdef AF_LOCAL static int get_local(const char *name, int socktype, struct addrinfo **res); #endif static int add_ipv4(const char *hostname, int flags, struct addrinfo **aip, int socktype, int port); static int add_ipv6(const char *hostname, int flags, struct addrinfo **aip, int socktype, int port); static void set_order(int, int (**)(const char *, int, struct addrinfo **, int, int)); #define FOUND_IPV4 0x1 #define FOUND_IPV6 0x2 #define FOUND_MAX 2 #define ISC_AI_MASK (AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST) /*% Get a list of IP addresses and port numbers for host hostname and service servname. */ int lwres_getaddrinfo(const char *hostname, const char *servname, const struct addrinfo *hints, struct addrinfo **res) { struct servent *sp; const char *proto; int family, socktype, flags, protocol; struct addrinfo *ai, *ai_list; int port, err, i; int (*net_order[FOUND_MAX+1])(const char *, int, struct addrinfo **, int, int); if (hostname == NULL && servname == NULL) return (EAI_NONAME); proto = NULL; if (hints != NULL) { if ((hints->ai_flags & ~(ISC_AI_MASK)) != 0) return (EAI_BADFLAGS); if (hints->ai_addrlen || hints->ai_canonname || hints->ai_addr || hints->ai_next) { errno = EINVAL; return (EAI_SYSTEM); } family = hints->ai_family; socktype = hints->ai_socktype; protocol = hints->ai_protocol; flags = hints->ai_flags; switch (family) { case AF_UNSPEC: switch (hints->ai_socktype) { case SOCK_STREAM: proto = "tcp"; break; case SOCK_DGRAM: proto = "udp"; break; } break; case AF_INET: case AF_INET6: switch (hints->ai_socktype) { case 0: break; case SOCK_STREAM: proto = "tcp"; break; case SOCK_DGRAM: proto = "udp"; break; case SOCK_RAW: break; default: return (EAI_SOCKTYPE); } break; #ifdef AF_LOCAL case AF_LOCAL: switch (hints->ai_socktype) { case 0: break; case SOCK_STREAM: break; case SOCK_DGRAM: break; default: return (EAI_SOCKTYPE); } break; #endif default: return (EAI_FAMILY); } } else { protocol = 0; family = 0; socktype = 0; flags = 0; } #ifdef AF_LOCAL /*! * First, deal with AF_LOCAL. If the family was not set, * then assume AF_LOCAL if the first character of the * hostname/servname is '/'. */ if (hostname != NULL && (family == AF_LOCAL || (family == 0 && *hostname == '/'))) return (get_local(hostname, socktype, res)); if (servname != NULL && (family == AF_LOCAL || (family == 0 && *servname == '/'))) return (get_local(servname, socktype, res)); #endif /* * Ok, only AF_INET and AF_INET6 left. */ ai_list = NULL; /* * First, look up the service name (port) if it was * requested. If the socket type wasn't specified, then * try and figure it out. */ if (servname != NULL) { char *e; port = strtol(servname, &e, 10); if (*e == '\0') { if (socktype == 0) return (EAI_SOCKTYPE); if (port < 0 || port > 65535) return (EAI_SERVICE); port = htons((unsigned short) port); } else { sp = getservbyname(servname, proto); if (sp == NULL) return (EAI_SERVICE); port = sp->s_port; if (socktype == 0) { if (strcmp(sp->s_proto, "tcp") == 0) socktype = SOCK_STREAM; else if (strcmp(sp->s_proto, "udp") == 0) socktype = SOCK_DGRAM; } } } else port = 0; /* * Next, deal with just a service name, and no hostname. * (we verified that one of them was non-null up above). */ if (hostname == NULL && (flags & AI_PASSIVE) != 0) { if (family == AF_INET || family == 0) { ai = ai_alloc(AF_INET, sizeof(struct sockaddr_in)); if (ai == NULL) return (EAI_MEMORY); ai->ai_socktype = socktype; ai->ai_protocol = protocol; SIN(ai->ai_addr)->sin_port = port; ai->ai_next = ai_list; ai_list = ai; } if (family == AF_INET6 || family == 0) { ai = ai_alloc(AF_INET6, sizeof(struct sockaddr_in6)); if (ai == NULL) { lwres_freeaddrinfo(ai_list); return (EAI_MEMORY); } ai->ai_socktype = socktype; ai->ai_protocol = protocol; SIN6(ai->ai_addr)->sin6_port = port; ai->ai_next = ai_list; ai_list = ai; } *res = ai_list; return (0); } /* * If the family isn't specified or AI_NUMERICHOST specified, * check first to see if it is a numeric address. * Though the gethostbyname2() routine * will recognize numeric addresses, it will only recognize * the format that it is being called for. Thus, a numeric * AF_INET address will be treated by the AF_INET6 call as * a domain name, and vice versa. Checking for both numerics * here avoids that. */ if (hostname != NULL && (family == 0 || (flags & AI_NUMERICHOST) != 0)) { char abuf[sizeof(struct in6_addr)]; char nbuf[NI_MAXHOST]; int addrsize, addroff; #ifdef LWRES_HAVE_SIN6_SCOPE_ID char *p, *ep; char ntmp[NI_MAXHOST]; lwres_uint32_t scopeid; #endif #ifdef LWRES_HAVE_SIN6_SCOPE_ID /* * Scope identifier portion. */ ntmp[0] = '\0'; if (strchr(hostname, '%') != NULL) { strlcpy(ntmp, hostname, sizeof(ntmp)); p = strchr(ntmp, '%'); ep = NULL; /* * Vendors may want to support non-numeric * scopeid around here. */ if (p != NULL) scopeid = (lwres_uint32_t)strtoul(p + 1, &ep, 10); if (p != NULL && ep != NULL && ep[0] == '\0') *p = '\0'; else { ntmp[0] = '\0'; scopeid = 0; } } else scopeid = 0; #endif if (lwres_net_pton(AF_INET, hostname, (struct in_addr *)abuf) == 1) { if (family == AF_INET6) { /* * Convert to a V4 mapped address. */ struct in6_addr *a6 = (struct in6_addr *)abuf; memcpy(&a6->s6_addr[12], &a6->s6_addr[0], 4); memset(&a6->s6_addr[10], 0xff, 2); memset(&a6->s6_addr[0], 0, 10); goto inet6_addr; } addrsize = sizeof(struct in_addr); addroff = (char *)(&SIN(0)->sin_addr) - (char *)0; family = AF_INET; goto common; #ifdef LWRES_HAVE_SIN6_SCOPE_ID } else if (ntmp[0] != '\0' && lwres_net_pton(AF_INET6, ntmp, abuf) == 1) { if (family && family != AF_INET6) return (EAI_NONAME); addrsize = sizeof(struct in6_addr); addroff = (char *)(&SIN6(0)->sin6_addr) - (char *)0; family = AF_INET6; goto common; #endif } else if (lwres_net_pton(AF_INET6, hostname, abuf) == 1) { if (family != 0 && family != AF_INET6) return (EAI_NONAME); inet6_addr: addrsize = sizeof(struct in6_addr); addroff = (char *)(&SIN6(0)->sin6_addr) - (char *)0; family = AF_INET6; common: ai = ai_clone(ai_list, family); if (ai == NULL) return (EAI_MEMORY); ai_list = ai; ai->ai_socktype = socktype; SIN(ai->ai_addr)->sin_port = port; memcpy((char *)ai->ai_addr + addroff, abuf, addrsize); if (flags & AI_CANONNAME) { #if defined(LWRES_HAVE_SIN6_SCOPE_ID) if (ai->ai_family == AF_INET6) SIN6(ai->ai_addr)->sin6_scope_id = scopeid; #endif if (lwres_getnameinfo(ai->ai_addr, ai->ai_addrlen, nbuf, sizeof(nbuf), NULL, 0, NI_NUMERICHOST) == 0) { ai->ai_canonname = strdup(nbuf); if (ai->ai_canonname == NULL) { lwres_freeaddrinfo(ai_list); return (EAI_MEMORY); } } else { /* XXX raise error? */ ai->ai_canonname = NULL; } } goto done; } else if ((flags & AI_NUMERICHOST) != 0) { return (EAI_NONAME); } } set_order(family, net_order); for (i = 0; i < FOUND_MAX; i++) { if (net_order[i] == NULL) break; err = (net_order[i])(hostname, flags, &ai_list, socktype, port); if (err != 0) return (err); } if (ai_list == NULL) return (EAI_NODATA); done: ai_list = ai_reverse(ai_list); *res = ai_list; return (0); } static char * lwres_strsep(char **stringp, const char *delim) { char *string = *stringp; char *s; const char *d; char sc, dc; if (string == NULL) return (NULL); for (s = string; *s != '\0'; s++) { sc = *s; for (d = delim; (dc = *d) != '\0'; d++) if (sc == dc) { *s++ = '\0'; *stringp = s; return (string); } } *stringp = NULL; return (string); } static void set_order(int family, int (**net_order)(const char *, int, struct addrinfo **, int, int)) { char *order, *tok; int found; if (family) { switch (family) { case AF_INET: *net_order++ = add_ipv4; break; case AF_INET6: *net_order++ = add_ipv6; break; } } else { order = getenv("NET_ORDER"); found = 0; while (order != NULL) { /* * We ignore any unknown names. */ tok = lwres_strsep(&order, ":"); if (strcasecmp(tok, "inet6") == 0) { if ((found & FOUND_IPV6) == 0) *net_order++ = add_ipv6; found |= FOUND_IPV6; } else if (strcasecmp(tok, "inet") == 0 || strcasecmp(tok, "inet4") == 0) { if ((found & FOUND_IPV4) == 0) *net_order++ = add_ipv4; found |= FOUND_IPV4; } } /* * Add in anything that we didn't find. */ if ((found & FOUND_IPV4) == 0) *net_order++ = add_ipv4; if ((found & FOUND_IPV6) == 0) *net_order++ = add_ipv6; } *net_order = NULL; return; } static char v4_loop[4] = { 127, 0, 0, 1 }; /* * The test against 0 is there to keep the Solaris compiler * from complaining about "end-of-loop code not reached". */ #define SETERROR(code) \ do { result = (code); \ if (result != 0) goto cleanup; \ } while (0) static int add_ipv4(const char *hostname, int flags, struct addrinfo **aip, int socktype, int port) { struct addrinfo *ai; lwres_context_t *lwrctx = NULL; lwres_gabnresponse_t *by = NULL; lwres_addr_t *addr; lwres_result_t lwres; int result = 0; lwres = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0); if (lwres != LWRES_R_SUCCESS) SETERROR(EAI_FAIL); (void) lwres_conf_parse(lwrctx, lwres_resolv_conf); if (hostname == NULL && (flags & AI_PASSIVE) == 0) { ai = ai_clone(*aip, AF_INET); if (ai == NULL) { lwres_freeaddrinfo(*aip); SETERROR(EAI_MEMORY); } *aip = ai; ai->ai_socktype = socktype; SIN(ai->ai_addr)->sin_port = port; memcpy(&SIN(ai->ai_addr)->sin_addr, v4_loop, 4); } else { lwres = lwres_getaddrsbyname(lwrctx, hostname, LWRES_ADDRTYPE_V4, &by); if (lwres != LWRES_R_SUCCESS) { if (lwres == LWRES_R_NOTFOUND) goto cleanup; else SETERROR(EAI_FAIL); } addr = LWRES_LIST_HEAD(by->addrs); while (addr != NULL) { ai = ai_clone(*aip, AF_INET); if (ai == NULL) { lwres_freeaddrinfo(*aip); SETERROR(EAI_MEMORY); } *aip = ai; ai->ai_socktype = socktype; SIN(ai->ai_addr)->sin_port = port; memcpy(&SIN(ai->ai_addr)->sin_addr, addr->address, 4); if (flags & AI_CANONNAME) { ai->ai_canonname = strdup(by->realname); if (ai->ai_canonname == NULL) SETERROR(EAI_MEMORY); } addr = LWRES_LIST_NEXT(addr, link); } } cleanup: if (by != NULL) lwres_gabnresponse_free(lwrctx, &by); if (lwrctx != NULL) { lwres_conf_clear(lwrctx); lwres_context_destroy(&lwrctx); } return (result); } static char v6_loop[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 }; static int add_ipv6(const char *hostname, int flags, struct addrinfo **aip, int socktype, int port) { struct addrinfo *ai; lwres_context_t *lwrctx = NULL; lwres_gabnresponse_t *by = NULL; lwres_addr_t *addr; lwres_result_t lwres; int result = 0; lwres = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0); if (lwres != LWRES_R_SUCCESS) SETERROR(EAI_FAIL); (void) lwres_conf_parse(lwrctx, lwres_resolv_conf); if (hostname == NULL && (flags & AI_PASSIVE) == 0) { ai = ai_clone(*aip, AF_INET6); if (ai == NULL) { lwres_freeaddrinfo(*aip); SETERROR(EAI_MEMORY); } *aip = ai; ai->ai_socktype = socktype; SIN6(ai->ai_addr)->sin6_port = port; memcpy(&SIN6(ai->ai_addr)->sin6_addr, v6_loop, 16); } else { lwres = lwres_getaddrsbyname(lwrctx, hostname, LWRES_ADDRTYPE_V6, &by); if (lwres != LWRES_R_SUCCESS) { if (lwres == LWRES_R_NOTFOUND) goto cleanup; else SETERROR(EAI_FAIL); } addr = LWRES_LIST_HEAD(by->addrs); while (addr != NULL) { ai = ai_clone(*aip, AF_INET6); if (ai == NULL) { lwres_freeaddrinfo(*aip); SETERROR(EAI_MEMORY); } *aip = ai; ai->ai_socktype = socktype; SIN6(ai->ai_addr)->sin6_port = port; memcpy(&SIN6(ai->ai_addr)->sin6_addr, addr->address, 16); if (flags & AI_CANONNAME) { ai->ai_canonname = strdup(by->realname); if (ai->ai_canonname == NULL) SETERROR(EAI_MEMORY); } addr = LWRES_LIST_NEXT(addr, link); } } cleanup: if (by != NULL) lwres_gabnresponse_free(lwrctx, &by); if (lwrctx != NULL) { lwres_conf_clear(lwrctx); lwres_context_destroy(&lwrctx); } return (result); } /*% Free address info. */ void lwres_freeaddrinfo(struct addrinfo *ai) { struct addrinfo *ai_next; while (ai != NULL) { ai_next = ai->ai_next; if (ai->ai_addr != NULL) free(ai->ai_addr); if (ai->ai_canonname) free(ai->ai_canonname); free(ai); ai = ai_next; } } #ifdef AF_LOCAL static int get_local(const char *name, int socktype, struct addrinfo **res) { struct addrinfo *ai; struct sockaddr_un *sun; if (socktype == 0) return (EAI_SOCKTYPE); ai = ai_alloc(AF_LOCAL, sizeof(*sun)); if (ai == NULL) return (EAI_MEMORY); sun = SUN(ai->ai_addr); strlcpy(sun->sun_path, name, sizeof(sun->sun_path)); ai->ai_socktype = socktype; /* * ai->ai_flags, ai->ai_protocol, ai->ai_canonname, * and ai->ai_next were initialized to zero. */ *res = ai; return (0); } #endif /*! * Allocate an addrinfo structure, and a sockaddr structure * of the specificed length. We initialize: * ai_addrlen * ai_family * ai_addr * ai_addr->sa_family * ai_addr->sa_len (LWRES_PLATFORM_HAVESALEN) * and everything else is initialized to zero. */ static struct addrinfo * ai_alloc(int family, int addrlen) { struct addrinfo *ai; ai = (struct addrinfo *)calloc(1, sizeof(*ai)); if (ai == NULL) return (NULL); ai->ai_addr = SA(calloc(1, addrlen)); if (ai->ai_addr == NULL) { free(ai); return (NULL); } ai->ai_addrlen = addrlen; ai->ai_family = family; ai->ai_addr->sa_family = family; #ifdef LWRES_PLATFORM_HAVESALEN ai->ai_addr->sa_len = addrlen; #endif return (ai); } static struct addrinfo * ai_clone(struct addrinfo *oai, int family) { struct addrinfo *ai; ai = ai_alloc(family, ((family == AF_INET6) ? sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in))); if (ai == NULL) { lwres_freeaddrinfo(oai); return (NULL); } if (oai == NULL) return (ai); ai->ai_flags = oai->ai_flags; ai->ai_socktype = oai->ai_socktype; ai->ai_protocol = oai->ai_protocol; ai->ai_canonname = NULL; ai->ai_next = oai; return (ai); } static struct addrinfo * ai_reverse(struct addrinfo *oai) { struct addrinfo *nai, *tai; nai = NULL; while (oai != NULL) { /* * Grab one off the old list. */ tai = oai; oai = oai->ai_next; /* * Put it on the front of the new list. */ tai->ai_next = nai; nai = tai; } return (nai); }