diff options
Diffstat (limited to 'newlib/libc/sys/linux/net/getaddrinfo.c')
| -rw-r--r-- | newlib/libc/sys/linux/net/getaddrinfo.c | 1979 |
1 files changed, 1979 insertions, 0 deletions
diff --git a/newlib/libc/sys/linux/net/getaddrinfo.c b/newlib/libc/sys/linux/net/getaddrinfo.c new file mode 100644 index 000000000..97ba36209 --- /dev/null +++ b/newlib/libc/sys/linux/net/getaddrinfo.c @@ -0,0 +1,1979 @@ +/* $KAME: getaddrinfo.c,v 1.15 2000/07/09 04:37:24 itojun Exp $ */ + +/* + * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the project nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * "#ifdef FAITH" part is local hack for supporting IPv4-v6 translator. + * + * Issues to be discussed: + * - Thread safe-ness must be checked. + * - Return values. There are nonstandard return values defined and used + * in the source code. This is because RFC2553 is silent about which error + * code must be returned for which situation. + * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is + * invalid. + * current code - SEGV on freeaddrinfo(NULL) + * Note: + * - 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? + * - (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? + * - To avoid search order issue, we have a big amount of code duplicate + * from gethnamaddr.c and some other places. The issues that there's no + * lower layer function to lookup "IPv4 or IPv6" record. Calling + * gethostbyname2 from getaddrinfo will end up in wrong search order, as + * follows: + * - The code makes use of following calls when asked to resolver with + * ai_family = PF_UNSPEC: + * getipnodebyname(host, AF_INET6); + * getipnodebyname(host, AF_INET); + * This will result in the following queries if the node is configure to + * prefer /etc/hosts than DNS: + * lookup /etc/hosts for IPv6 address + * lookup DNS for IPv6 address + * lookup /etc/hosts for IPv4 address + * lookup DNS for IPv4 address + * which may not meet people's requirement. + * The right thing to happen is to have underlying layer which does + * PF_UNSPEC lookup (lookup both) and return chain of addrinfos. + * This would result in a bit of code duplicate with _dns_ghbyname() and + * friends. + */ +/* + * diffs with other KAME platforms: + * - other KAME platforms already nuked FAITH ($GAI), but as FreeBSD + * 4.0-RELEASE supplies it, we still have the code here. + * - AI_ADDRCONFIG support is supplied + * - some of FreeBSD style (#define tabify and others) + * - classful IPv4 numeric (127.1) is allowed. + */ + +#include <sys/cdefs.h> +#include <machine/endian.h> + +#include "namespace.h" +#include <sys/types.h> +#include <sys/types.h> +#include <sys/param.h> +#include <sys/socket.h> +#include <net/if.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <arpa/nameser.h> +#include <rpc/rpc.h> +#include <rpcsvc/yp_prot.h> +#include <rpcsvc/ypclnt.h> +#include <netdb.h> +#include <resolv.h> +#include <string.h> +#include <stdlib.h> +#include <stddef.h> +#include <ctype.h> +#include <unistd.h> +#include <stdio.h> +#include <errno.h> +#ifdef DEBUG +#include <syslog.h> +#endif + +#include <syslog.h> +#include <stdarg.h> +#include <nsswitch.h> +#include "un-namespace.h" + +#if defined(__KAME__) && defined(INET6) +# define FAITH +#endif + +#define SUCCESS 0 +#define ANY 0 +#define YES 1 +#define NO 0 + +static const char in_addrany[] = { 0, 0, 0, 0 }; +static const char 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[] = { +#if 0 + { PF_LOCAL, 0, ANY, ANY, NULL, 0x01 }, +#endif +#ifdef INET6 + { PF_INET6, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, + { PF_INET6, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, + { PF_INET6, SOCK_RAW, ANY, NULL, 0x05 }, +#endif + { PF_INET, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, + { PF_INET, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, + { PF_INET, SOCK_RAW, ANY, NULL, 0x05 }, + { PF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP, "udp", 0x07 }, + { PF_UNSPEC, SOCK_STREAM, IPPROTO_TCP, "tcp", 0x07 }, + { PF_UNSPEC, SOCK_RAW, ANY, NULL, 0x05 }, + { -1, 0, 0, NULL, 0 }, +}; + +#ifdef INET6 +#define PTON_MAX 16 +#else +#define PTON_MAX 4 +#endif + +static const ns_src default_dns_files[] = { + { NSSRC_FILES, NS_SUCCESS }, + { NSSRC_DNS, NS_SUCCESS }, + { 0 } +}; + +#if PACKETSZ > 1024 +#define MAXPACKET PACKETSZ +#else +#define MAXPACKET 1024 +#endif + +typedef union { + HEADER hdr; + u_char buf[MAXPACKET]; +} querybuf; + +struct res_target { + struct res_target *next; + const char *name; /* domain name */ + int qclass, qtype; /* class and type of query */ + u_char *answer; /* buffer to put answer */ + int anslen; /* size of answer buffer */ + int n; /* result length */ +}; + +static int str_isnumber(const char *); +static int explore_fqdn(const struct addrinfo *, const char *, + const char *, struct addrinfo **); +static int explore_null(const struct addrinfo *, + const char *, struct addrinfo **); +static int explore_numeric(const struct addrinfo *, const char *, + const char *, struct addrinfo **); +static int explore_numeric_scope(const struct addrinfo *, const char *, + const char *, struct addrinfo **); +static int get_canonname(const struct addrinfo *, + struct addrinfo *, const char *); +static struct addrinfo *get_ai(const struct addrinfo *, + const struct afd *, const char *); +static int get_portmatch(const struct addrinfo *, const char *); +static int get_port(struct addrinfo *, const char *, int); +static const struct afd *find_afd(int); +static int addrconfig(struct addrinfo *); +#ifdef INET6 +static int ip6_str2scopeid(char *, struct sockaddr_in6 *); +#endif + +static struct addrinfo *getanswer(const querybuf *, int, const char *, int, + const struct addrinfo *); +static int _dns_getaddrinfo(void *, void *, va_list); +static void _sethtent(void); +static void _endhtent(void); +static struct addrinfo *_gethtent(const char *, const struct addrinfo *); +static int _files_getaddrinfo(void *, void *, va_list); +#ifdef YP +static struct addrinfo *_yphostent(char *, const struct addrinfo *); +static int _yp_getaddrinfo(void *, void *, va_list); +extern int _yp_check(char **); +#endif + +u_int16_t _getshort(const u_char *src); + +static int res_queryN(const char *, struct res_target *); +static int res_searchN(const char *, struct res_target *); +static int res_querydomainN(const char *, const char *, + struct res_target *); + +static char *ai_errlist[] = { + "Success", + "Address family for hostname not supported", /* EAI_ADDRFAMILY */ + "Temporary failure in name resolution", /* EAI_AGAIN */ + "Invalid value for ai_flags", /* EAI_BADFLAGS */ + "Non-recoverable failure in name resolution", /* EAI_FAIL */ + "ai_family not supported", /* EAI_FAMILY */ + "Memory allocation failure", /* EAI_MEMORY */ + "No address associated with hostname", /* EAI_NODATA */ + "hostname nor servname provided, or not known", /* EAI_NONAME */ + "servname not supported for ai_socktype", /* EAI_SERVICE */ + "ai_socktype not supported", /* EAI_SOCKTYPE */ + "System error returned in errno", /* EAI_SYSTEM */ + "Invalid value for hints", /* EAI_BADHINTS */ + "Resolved protocol is unknown", /* EAI_PROTOCOL */ + "Unknown error", /* EAI_MAX */ +}; + +/* XXX macros that make external reference is BAD. */ + +#define GET_AI(ai, afd, addr) \ +do { \ + /* external reference: pai, error, and label free */ \ + (ai) = get_ai(pai, (afd), (addr)); \ + if ((ai) == NULL) { \ + error = EAI_MEMORY; \ + goto free; \ + } \ +} while (/*CONSTCOND*/0) + +#define GET_PORT(ai, serv) \ +do { \ + /* external reference: error and label free */ \ + error = get_port((ai), (serv), 0); \ + if (error != 0) \ + goto free; \ +} while (/*CONSTCOND*/0) + +#define GET_CANONNAME(ai, str) \ +do { \ + /* external reference: pai, error and label free */ \ + error = get_canonname(pai, (ai), (str)); \ + if (error != 0) \ + goto free; \ +} while (/*CONSTCOND*/0) + +#define ERR(err) \ +do { \ + /* external reference: error, and label bad */ \ + error = (err); \ + goto bad; \ + /*NOTREACHED*/ \ +} while (/*CONSTCOND*/0) + +#define MATCH_FAMILY(x, y, w) \ + ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || (y) == PF_UNSPEC))) +#define MATCH(x, y, w) \ + ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY))) + +char * +gai_strerror(ecode) + int ecode; +{ + if (ecode < 0 || ecode > EAI_MAX) + ecode = EAI_MAX; + return ai_errlist[ecode]; +} + +void +freeaddrinfo(ai) + struct addrinfo *ai; +{ + struct addrinfo *next; + + do { + next = ai->ai_next; + if (ai->ai_canonname) + free(ai->ai_canonname); + /* no need to free(ai->ai_addr) */ + free(ai); + ai = next; + } while (ai); +} + +static int +str_isnumber(p) + const char *p; +{ + char *ep; + + if (*p == '\0') + return NO; + ep = NULL; + (void)strtoul(p, &ep, 10); + if (ep && *ep == '\0') + return YES; + else + return NO; +} + +int +getaddrinfo(hostname, servname, hints, res) + const char *hostname, *servname; + const struct addrinfo *hints; + struct addrinfo **res; +{ + struct addrinfo sentinel; + struct addrinfo *cur; + int error = 0; + struct addrinfo ai; + struct addrinfo ai0; + struct addrinfo *pai; + const struct explore *ex; + + memset(&sentinel, 0, sizeof(sentinel)); + cur = &sentinel; + pai = &ai; + pai->ai_flags = 0; + pai->ai_family = PF_UNSPEC; + pai->ai_socktype = ANY; + pai->ai_protocol = ANY; + pai->ai_addrlen = 0; + pai->ai_canonname = NULL; + pai->ai_addr = NULL; + pai->ai_next = NULL; + + if (hostname == NULL && servname == NULL) + return EAI_NONAME; + if (hints) { + /* error check for hints */ + if (hints->ai_addrlen || hints->ai_canonname || + hints->ai_addr || hints->ai_next) + ERR(EAI_BADHINTS); /* xxx */ + if (hints->ai_flags & ~AI_MASK) + ERR(EAI_BADFLAGS); + switch (hints->ai_family) { + case PF_UNSPEC: + case PF_INET: +#ifdef INET6 + case PF_INET6: +#endif + break; + default: + ERR(EAI_FAMILY); + } + memcpy(pai, hints, sizeof(*pai)); + + /* + * if both socktype/protocol are specified, check if they + * are meaningful combination. + */ + if (pai->ai_socktype != ANY && pai->ai_protocol != ANY) { + for (ex = explore; ex->e_af >= 0; ex++) { + if (pai->ai_family != ex->e_af) + continue; + if (ex->e_socktype == ANY) + continue; + if (ex->e_protocol == ANY) + continue; + if (pai->ai_socktype == ex->e_socktype + && pai->ai_protocol != ex->e_protocol) { + ERR(EAI_BADHINTS); + } + } + } + } + + /* + * post-2553: AI_ALL and AI_V4MAPPED are effective only against + * AF_INET6 query. They needs to be ignored if specified in other + * occassions. + */ + switch (pai->ai_flags & (AI_ALL | AI_V4MAPPED)) { + case AI_V4MAPPED: + case AI_ALL | AI_V4MAPPED: + if (pai->ai_family != AF_INET6) + pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); + break; + case AI_ALL: +#if 1 + /* illegal */ + ERR(EAI_BADFLAGS); +#else + pai->ai_flags &= ~(AI_ALL | AI_V4MAPPED); +#endif + break; + } + + /* + * check for special cases. (1) numeric servname is disallowed if + * socktype/protocol are left unspecified. (2) servname is disallowed + * for raw and other inet{,6} sockets. + */ + if (MATCH_FAMILY(pai->ai_family, PF_INET, 1) +#ifdef PF_INET6 + || MATCH_FAMILY(pai->ai_family, PF_INET6, 1) +#endif + ) { + ai0 = *pai; /* backup *pai */ + + if (pai->ai_family == PF_UNSPEC) { +#ifdef PF_INET6 + pai->ai_family = PF_INET6; +#else + pai->ai_family = PF_INET; +#endif + } + error = get_portmatch(pai, servname); + if (error) + ERR(error); + + *pai = ai0; + } + + ai0 = *pai; + + /* NULL hostname, or numeric hostname */ + for (ex = explore; ex->e_af >= 0; ex++) { + *pai = ai0; + + /* PF_UNSPEC entries are prepared for DNS queries only */ + if (ex->e_af == PF_UNSPEC) + continue; + + if (!MATCH_FAMILY(pai->ai_family, ex->e_af, WILD_AF(ex))) + continue; + if (!MATCH(pai->ai_socktype, ex->e_socktype, WILD_SOCKTYPE(ex))) + continue; + if (!MATCH(pai->ai_protocol, ex->e_protocol, WILD_PROTOCOL(ex))) + continue; + + if (pai->ai_family == PF_UNSPEC) + pai->ai_family = ex->e_af; + if (pai->ai_socktype == ANY && ex->e_socktype != ANY) + pai->ai_socktype = ex->e_socktype; + if (pai->ai_protocol == ANY && ex->e_protocol != ANY) + pai->ai_protocol = ex->e_protocol; + + if (hostname == NULL) + error = explore_null(pai, servname, &cur->ai_next); + else + error = explore_numeric_scope(pai, hostname, servname, &cur->ai_next); + + if (error) + goto free; + + while (cur && cur->ai_next) + cur = cur->ai_next; + } + + /* + * XXX + * If numreic representation of AF1 can be interpreted as FQDN + * representation of AF2, we need to think again about the code below. + */ + if (sentinel.ai_next) + goto good; + + if (pai->ai_flags & AI_NUMERICHOST) + ERR(EAI_NONAME); + if (hostname == NULL) + ERR(EAI_NODATA); + + if ((pai->ai_flags & AI_ADDRCONFIG) != 0 && !addrconfig(&ai0)) + ERR(EAI_FAIL); + + /* + * hostname as alphabetical name. + * we would like to prefer AF_INET6 than AF_INET, so we'll make a + * outer loop by AFs. + */ + for (ex = explore; ex->e_af >= 0; ex++) { + *pai = ai0; + + /* require exact match for family field */ + if (pai->ai_family != ex->e_af) + continue; + + if (!MATCH(pai->ai_socktype, ex->e_socktype, + WILD_SOCKTYPE(ex))) { + continue; + } + if (!MATCH(pai->ai_protocol, ex->e_protocol, + WILD_PROTOCOL(ex))) { + continue; + } + + if (pai->ai_socktype == ANY && ex->e_socktype != ANY) + pai->ai_socktype = ex->e_socktype; + if (pai->ai_protocol == ANY && ex->e_protocol != ANY) + pai->ai_protocol = ex->e_protocol; + + error = explore_fqdn(pai, hostname, servname, + &cur->ai_next); + + while (cur && cur->ai_next) + cur = cur->ai_next; + } + + /* XXX */ + if (sentinel.ai_next) + error = 0; + + if (error) + goto free; + if (error == 0) { + if (sentinel.ai_next) { + good: + *res = sentinel.ai_next; + return SUCCESS; + } else + error = EAI_FAIL; + } + free: + bad: + if (sentinel.ai_next) + freeaddrinfo(sentinel.ai_next); + *res = NULL; + return error; +} + +/* + * FQDN hostname, DNS lookup + */ +static int +explore_fqdn(pai, hostname, servname, res) + const struct addrinfo *pai; + const char *hostname; + const char *servname; + struct addrinfo **res; +{ + struct addrinfo *result; + struct addrinfo *cur; + int error = 0; + static const ns_dtab dtab[] = { + NS_FILES_CB(_files_getaddrinfo, NULL) + { NSSRC_DNS, _dns_getaddrinfo, NULL }, /* force -DHESIOD */ + NS_NIS_CB(_yp_getaddrinfo, NULL) + { 0 } + }; + + result = NULL; + + /* + * 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_NODATA; + goto free; + case NS_SUCCESS: + error = 0; + for (cur = result; cur; cur = cur->ai_next) { + GET_PORT(cur, servname); + /* canonname should be filled already */ + } + break; + } + + *res = result; + + return 0; + +free: + if (result) + freeaddrinfo(result); + return error; +} + +/* + * hostname == NULL. + * passive socket -> anyaddr (0.0.0.0 or ::) + * non-passive socket -> localhost (127.0.0.1 or ::1) + */ +static int +explore_null(pai, servname, res) + const struct addrinfo *pai; + const char *servname; + struct addrinfo **res; +{ + int s; + const struct afd *afd; + struct addrinfo *cur; + struct addrinfo sentinel; + int error; + + *res = NULL; + sentinel.ai_next = NULL; + cur = &sentinel; + + /* + * filter out AFs that are not supported by the kernel + * XXX errno? + */ + s = socket(pai->ai_family, SOCK_DGRAM, 0); + if (s < 0) { + if (errno != EMFILE) + return 0; + } else + close(s); + + /* + * if the servname does not match socktype/protocol, ignore it. + */ + if (get_portmatch(pai, servname) != 0) + return 0; + + afd = find_afd(pai->ai_family); + if (afd == NULL) + return 0; + + if (pai->ai_flags & AI_PASSIVE) { + GET_AI(cur->ai_next, afd, afd->a_addrany); + /* xxx meaningless? + * GET_CANONNAME(cur->ai_next, "anyaddr"); + */ + GET_PORT(cur->ai_next, servname); + } else { + GET_AI(cur->ai_next, afd, afd->a_loopback); + /* xxx meaningless? + * GET_CANONNAME(cur->ai_next, "localhost"); + */ + GET_PORT(cur->ai_next, servname); + } + cur = cur->ai_next; + + *res = sentinel.ai_next; + return 0; + +free: + if (sentinel.ai_next) + freeaddrinfo(sentinel.ai_next); + return error; +} + +/* + * numeric hostname + */ +static int +explore_numeric(pai, hostname, servname, res) + const struct addrinfo *pai; + const char *hostname; + const char *servname; + struct addrinfo **res; +{ + const struct afd *afd; + struct addrinfo *cur; + struct addrinfo sentinel; + int error; + char pton[PTON_MAX]; + + *res = NULL; + sentinel.ai_next = NULL; + cur = &sentinel; + + /* + * if the servname does not match socktype/protocol, ignore it. + */ + if (get_portmatch(pai, servname) != 0) + return 0; + + afd = find_afd(pai->ai_family); + if (afd == NULL) + return 0; + + switch (afd->a_af) { +#if 1 /*X/Open spec*/ + case AF_INET: + if (inet_aton(hostname, (struct in_addr *)pton) == 1) { + if (pai->ai_family == afd->a_af || + pai->ai_family == PF_UNSPEC /*?*/) { + GET_AI(cur->ai_next, afd, pton); + GET_PORT(cur->ai_next, servname); + while (cur && cur->ai_next) + cur = cur->ai_next; + } else + ERR(EAI_FAMILY); /*xxx*/ + } + break; +#endif + default: + if (inet_pton(afd->a_af, hostname, pton) == 1) { + if (pai->ai_family == afd->a_af || + pai->ai_family == PF_UNSPEC /*?*/) { + GET_AI(cur->ai_next, afd, pton); + GET_PORT(cur->ai_next, servname); + while (cur && cur->ai_next) + cur = cur->ai_next; + } else + ERR(EAI_FAMILY); /*xxx*/ + } + break; + } + + *res = sentinel.ai_next; + return 0; + +free: +bad: + if (sentinel.ai_next) + freeaddrinfo(sentinel.ai_next); + return error; +} + +/* + * numeric hostname with scope + */ +static int +explore_numeric_scope(pai, hostname, servname, res) + const struct addrinfo *pai; + const char *hostname; + const char *servname; + struct addrinfo **res; +{ +#if !defined(SCOPE_DELIMITER) || !defined(INET6) + return explore_numeric(pai, hostname, servname, res); +#else + const struct afd *afd; + struct addrinfo *cur; + int error; + char *cp, *hostname2 = NULL, *scope, *addr; + struct sockaddr_in6 *sin6; + + /* + * if the servname does not match socktype/protocol, ignore it. + */ + if (get_portmatch(pai, servname) != 0) + return 0; + + afd = find_afd(pai->ai_family); + if (afd == NULL) + return 0; + + if (!afd->a_scoped) + return explore_numeric(pai, hostname, servname, res); + + cp = strchr(hostname, SCOPE_DELIMITER); + if (cp == NULL) + return explore_numeric(pai, hostname, servname, res); + + /* + * Handle special case of <scoped_address><delimiter><scope id> + */ + hostname2 = strdup(hostname); + if (hostname2 == NULL) + return EAI_MEMORY; + /* terminate at the delimiter */ + hostname2[cp - hostname] = '\0'; + addr = hostname2; + scope = cp + 1; + + error = explore_numeric(pai, addr, servname, res); + if (error == 0) { + int 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 ((scopeid = ip6_str2scopeid(scope, sin6)) == -1) { + free(hostname2); + return(EAI_NODATA); /* XXX: is return OK? */ + } + sin6->sin6_scope_id = scopeid; + } + } + + free(hostname2); + + return error; +#endif +} + +static int +get_canonname(pai, ai, str) + const struct addrinfo *pai; + struct addrinfo *ai; + const char *str; +{ + if ((pai->ai_flags & AI_CANONNAME) != 0) { + ai->ai_canonname = (char *)malloc(strlen(str) + 1); + if (ai->ai_canonname == NULL) + return EAI_MEMORY; + 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 *)(void *)(ai + 1); + memset(ai->ai_addr, 0, (size_t)afd->a_socklen); + ai->ai_addrlen = afd->a_socklen; + ai->ai_addr->sa_family = ai->ai_family = afd->a_af; + p = (char *)(void *)(ai->ai_addr); +#ifdef FAITH + if (translate == 1) + memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); + else +#endif + memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); + return ai; +} + +static int +get_portmatch(ai, servname) + const struct addrinfo *ai; + const char *servname; +{ + + /* get_port does not touch first argument. when matchonly == 1. */ + /* LINTED const cast */ + return get_port((struct addrinfo *)ai, servname, 1); +} + +static int +get_port(ai, servname, matchonly) + struct addrinfo *ai; + const char *servname; + int matchonly; +{ + const char *proto; + struct servent *sp; + int port; + int allownumeric; + + if (servname == NULL) + return 0; + switch (ai->ai_family) { + case AF_INET: +#ifdef AF_INET6 + case AF_INET6: +#endif + break; + default: + return 0; + } + + switch (ai->ai_socktype) { + case SOCK_RAW: + return EAI_SERVICE; + case SOCK_DGRAM: + case SOCK_STREAM: + allownumeric = 1; + break; + case ANY: + allownumeric = 0; + break; + default: + return EAI_SOCKTYPE; + } + + if (str_isnumber(servname)) { + if (!allownumeric) + return EAI_SERVICE; + port = 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 *)(void *) + ai->ai_addr)->sin_port = port; + break; +#ifdef INET6 + case AF_INET6: + ((struct sockaddr_in6 *)(void *) + ai->ai_addr)->sin6_port = port; + break; +#endif + } + } + + return 0; +} + +static const struct afd * +find_afd(af) + int af; +{ + const struct afd *afd; + + if (af == PF_UNSPEC) + return NULL; + for (afd = afdl; afd->a_af; afd++) { + if (afd->a_af == af) + return afd; + } + return NULL; +} + +/* + * post-2553: AI_ADDRCONFIG check. if we use getipnodeby* as backend, backend + * will take care of it. + * the semantics of AI_ADDRCONFIG is not defined well. we are not sure + * if the code is right or not. + * + * XXX PF_UNSPEC -> PF_INET6 + PF_INET mapping needs to be in sync with + * _dns_getaddrinfo. + */ +static int +addrconfig(pai) + struct addrinfo *pai; +{ + int s, af; + + /* + * TODO: + * Note that implementation dependent test for address + * configuration should be done everytime called + * (or apropriate interval), + * because addresses will be dynamically assigned or deleted. + */ + af = pai->ai_family; + if (af == AF_UNSPEC) { + if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) + af = AF_INET; + else { + close(s); + if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) + af = AF_INET6; + else + close(s); + } + } + if (af != AF_UNSPEC) { + if ((s = socket(af, SOCK_DGRAM, 0)) < 0) + return 0; + close(s); + } + pai->ai_family = af; + return 1; +} + +#ifdef INET6 +/* convert a string to a scope identifier. XXX: IPv6 specific */ +static int +ip6_str2scopeid(scope, sin6) + char *scope; + struct sockaddr_in6 *sin6; +{ + int scopeid; + struct in6_addr *a6 = &sin6->sin6_addr; + char *ep; + + /* empty scopeid portion is invalid */ + if (*scope == '\0') + return -1; + + if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { + /* + * We currently assume a one-to-one mapping between links + * and interfaces, so we simply use interface indices for + * like-local scopes. + */ + scopeid = if_nametoindex(scope); + if (scopeid == 0) + goto trynumeric; + return(scopeid); + } + + /* 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: + scopeid = (int)strtoul(scope, &ep, 10); + if (*ep == '\0') + return scopeid; + else + return -1; +} +#endif + +#ifdef DEBUG +static const char AskedForGot[] = + "gethostby*.getanswer: asked for \"%s\", got \"%s\""; +#endif +static FILE *hostf = NULL; + +static struct addrinfo * +getanswer(answer, anslen, qname, qtype, pai) + const querybuf *answer; + int anslen; + const char *qname; + int qtype; + const struct addrinfo *pai; +{ + struct addrinfo sentinel, *cur; + struct addrinfo ai; + const struct afd *afd; + char *canonname; + const HEADER *hp; + const u_char *cp; + int n; + const u_char *eom; + char *bp; + int type, class, buflen, 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; + buflen = sizeof hostbuf; + cp = answer->buf + HFIXEDSZ; + if (qdcount != 1) { + h_errno = NO_RECOVERY; + return (NULL); + } + n = dn_expand(answer->buf, eom, cp, bp, buflen); + if ((n < 0) || !(*name_ok)(bp)) { + h_errno = NO_RECOVERY; + return (NULL); + } + cp += n + QFIXEDSZ; + if (qtype == T_A || qtype == T_AAAA || qtype == T_ANY) { + /* res_send() has already verified that the query name is the + * same as the one we sent; this just gets the expanded name + * (i.e., with the succeeding search-domain tacked on). + */ + n = strlen(bp) + 1; /* for the \0 */ + if (n >= MAXHOSTNAMELEN) { + h_errno = NO_RECOVERY; + return (NULL); + } + canonname = bp; + bp += n; + buflen -= 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, buflen); + 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 > buflen || n >= MAXHOSTNAMELEN) { + had_error++; + continue; + } + strcpy(bp, tbuf); + canonname = bp; + bp += n; + buflen -= n; + continue; + } + if (qtype == T_ANY) { + if (!(type == T_A || type == T_AAAA)) { + cp += n; + continue; + } + } else if (type != qtype) { +#ifdef DEBUG + if (type != T_KEY && type != T_SIG) + syslog(LOG_NOTICE|LOG_AUTH, + "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", + qname, p_class(C_IN), p_type(qtype), + p_type(type)); +#endif + cp += n; + continue; /* XXX - had_error++ ? */ + } + switch (type) { + case T_A: + case T_AAAA: + if (strcasecmp(canonname, bp) != 0) { +#ifdef DEBUG + syslog(LOG_NOTICE|LOG_AUTH, + AskedForGot, canonname, bp); +#endif + cp += n; + continue; /* XXX - had_error++ ? */ + } + if (type == T_A && n != INADDRSZ) { + cp += n; + continue; + } + if (type == T_AAAA && n != IN6ADDRSZ) { + cp += n; + continue; + } +#ifdef FILTER_V4MAPPED + if (type == T_AAAA) { + struct in6_addr in6; + memcpy(&in6, cp, sizeof(in6)); + if (IN6_IS_ADDR_V4MAPPED(&in6)) { + cp += n; + continue; + } + } +#endif + if (!haveanswer) { + int nn; + + canonname = bp; + nn = strlen(bp) + 1; /* for the \0 */ + bp += nn; + buflen -= 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 (!canonname) + (void)get_canonname(pai, sentinel.ai_next, qname); + else + (void)get_canonname(pai, sentinel.ai_next, canonname); + h_errno = NETDB_SUCCESS; + return sentinel.ai_next; + } + + h_errno = NO_RECOVERY; + return NULL; +} + +/*ARGSUSED*/ +static int +_dns_getaddrinfo(rv, cb_data, ap) + void *rv; + void *cb_data; + va_list ap; +{ + struct addrinfo *ai; + querybuf buf, buf2; + const char *name; + const struct addrinfo *pai; + struct addrinfo sentinel, *cur; + struct res_target q, q2; + + name = va_arg(ap, char *); + pai = va_arg(ap, const struct addrinfo *); + + memset(&q, 0, sizeof(q2)); + memset(&q2, 0, sizeof(q2)); + memset(&sentinel, 0, sizeof(sentinel)); + cur = &sentinel; + + switch (pai->ai_family) { + case AF_UNSPEC: + /* prefer IPv6 */ + q.qclass = C_IN; + q.qtype = T_AAAA; + q.answer = buf.buf; + q.anslen = sizeof(buf); + q.next = &q2; + q2.qclass = C_IN; + q2.qtype = T_A; + q2.answer = buf2.buf; + q2.anslen = sizeof(buf2); + break; + case AF_INET: + q.qclass = C_IN; + q.qtype = T_A; + q.answer = buf.buf; + q.anslen = sizeof(buf); + break; + case AF_INET6: + q.qclass = C_IN; + q.qtype = T_AAAA; + q.answer = buf.buf; + q.anslen = sizeof(buf); + break; + default: + return NS_UNAVAIL; + } + if (res_searchN(name, &q) < 0) + return NS_NOTFOUND; + ai = getanswer(&buf, q.n, q.name, q.qtype, pai); + if (ai) { + cur->ai_next = ai; + while (cur && cur->ai_next) + cur = cur->ai_next; + } + if (q.next) { + ai = getanswer(&buf2, q2.n, q2.name, q2.qtype, pai); + if (ai) + cur->ai_next = ai; + } + if (sentinel.ai_next == NULL) + switch (h_errno) { + case HOST_NOT_FOUND: + return NS_NOTFOUND; + case TRY_AGAIN: + return NS_TRYAGAIN; + default: + return NS_UNAVAIL; + } + *((struct addrinfo **)rv) = sentinel.ai_next; + return NS_SUCCESS; +} + +static void +_sethtent() +{ + if (!hostf) + hostf = fopen(_PATH_HOSTS, "r" ); + else + rewind(hostf); +} + +static void +_endhtent() +{ + if (hostf) { + (void) fclose(hostf); + hostf = NULL; + } +} + +static struct addrinfo * +_gethtent(name, pai) + const char *name; + const struct addrinfo *pai; +{ + char *p; + char *cp, *tname, *cname; + struct addrinfo hints, *res0, *res; + int error; + const char *addr; + char hostbuf[8*1024]; + + if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) + return (NULL); + again: + if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) + return (NULL); + if (*p == '#') + goto again; + if (!(cp = strpbrk(p, "#\n"))) + goto again; + *cp = '\0'; + if (!(cp = strpbrk(p, " \t"))) + goto again; + *cp++ = '\0'; + addr = p; + cname = NULL; + /* if this is not something we're looking for, skip it. */ + while (cp && *cp) { + if (*cp == ' ' || *cp == '\t') { + cp++; + continue; + } + tname = cp; + if (cname == NULL) + cname = cp; + if ((cp = strpbrk(cp, " \t")) != NULL) + *cp++ = '\0'; + if (strcasecmp(name, tname) == 0) + goto found; + } + goto again; + +found: + hints = *pai; + hints.ai_flags = AI_NUMERICHOST; + error = getaddrinfo(addr, NULL, &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; + + if (pai->ai_flags & AI_CANONNAME) { + if (get_canonname(pai, res, cname) != 0) { + freeaddrinfo(res0); + goto again; + } + } + } + return res0; +} + +/*ARGSUSED*/ +static int +_files_getaddrinfo(rv, cb_data, ap) + void *rv; + void *cb_data; + va_list ap; +{ + const char *name; + const struct addrinfo *pai; + struct addrinfo sentinel, *cur; + struct addrinfo *p; + + name = va_arg(ap, char *); + pai = va_arg(ap, struct addrinfo *); + + memset(&sentinel, 0, sizeof(sentinel)); + cur = &sentinel; + + _sethtent(); + while ((p = _gethtent(name, pai)) != NULL) { + cur->ai_next = p; + while (cur && cur->ai_next) + cur = cur->ai_next; + } + _endhtent(); + + *((struct addrinfo **)rv) = sentinel.ai_next; + if (sentinel.ai_next == NULL) + return NS_NOTFOUND; + return NS_SUCCESS; +} + +#ifdef YP +static char *__ypdomain; + +/*ARGSUSED*/ +static struct addrinfo * +_yphostent(line, pai) + char *line; + const struct addrinfo *pai; +{ + struct addrinfo sentinel, *cur; + struct addrinfo hints, *res, *res0; + int error; + char *p = line; + const char *addr, *canonname; + char *nextline; + char *cp; + + addr = canonname = NULL; + + memset(&sentinel, 0, sizeof(sentinel)); + cur = &sentinel; + +nextline: + /* terminate line */ + cp = strchr(p, '\n'); + if (cp) { + *cp++ = '\0'; + nextline = cp; + } else + nextline = NULL; + + cp = strpbrk(p, " \t"); + if (cp == NULL) { + if (canonname == NULL) + return (NULL); + else + goto done; + } + *cp++ = '\0'; + + addr = p; + + while (cp && *cp) { + if (*cp == ' ' || *cp == '\t') { + cp++; + continue; + } + if (!canonname) + canonname = cp; + if ((cp = strpbrk(cp, " \t")) != NULL) + *cp++ = '\0'; + } + + hints = *pai; + hints.ai_flags = AI_NUMERICHOST; + error = getaddrinfo(addr, NULL, &hints, &res0); + if (error == 0) { + for (res = res0; res; res = res->ai_next) { + /* cover it up */ + res->ai_flags = pai->ai_flags; + + if (pai->ai_flags & AI_CANONNAME) + (void)get_canonname(pai, res, canonname); + } + } else + res0 = NULL; + if (res0) { + cur->ai_next = res0; + while (cur && cur->ai_next) + cur = cur->ai_next; + } + + if (nextline) { + p = nextline; + goto nextline; + } + +done: + return sentinel.ai_next; +} + +/*ARGSUSED*/ +static int +_yp_getaddrinfo(rv, cb_data, ap) + void *rv; + void *cb_data; + va_list ap; +{ + struct addrinfo sentinel, *cur; + struct addrinfo *ai = NULL; + static char *__ypcurrent; + int __ypcurrentlen, r; + const char *name; + const struct addrinfo *pai; + + name = va_arg(ap, char *); + pai = va_arg(ap, const struct addrinfo *); + + memset(&sentinel, 0, sizeof(sentinel)); + cur = &sentinel; + + if (!__ypdomain) { + if (_yp_check(&__ypdomain) == 0) + return NS_UNAVAIL; + } + if (__ypcurrent) + free(__ypcurrent); + __ypcurrent = NULL; + + /* hosts.byname is only for IPv4 (Solaris8) */ + if (pai->ai_family == PF_UNSPEC || pai->ai_family == PF_INET) { + r = yp_match(__ypdomain, "hosts.byname", name, + (int)strlen(name), &__ypcurrent, &__ypcurrentlen); + if (r == 0) { + struct addrinfo ai4; + + ai4 = *pai; + ai4.ai_family = AF_INET; + ai = _yphostent(__ypcurrent, &ai4); + if (ai) { + cur->ai_next = ai; + while (cur && cur->ai_next) + cur = cur->ai_next; + } + } + } + + /* ipnodes.byname can hold both IPv4/v6 */ + r = yp_match(__ypdomain, "ipnodes.byname", name, + (int)strlen(name), &__ypcurrent, &__ypcurrentlen); + if (r == 0) { + ai = _yphostent(__ypcurrent, pai); + if (ai) { + cur->ai_next = ai; + while (cur && cur->ai_next) + cur = cur->ai_next; + } + } + + if (sentinel.ai_next == NULL) { + h_errno = HOST_NOT_FOUND; + return NS_NOTFOUND; + } + *((struct addrinfo **)rv) = sentinel.ai_next; + return NS_SUCCESS; +} +#endif + +/* resolver logic */ + +extern const char *__hostalias(const char *); +extern int h_errno; + +/* + * Formulate a normal query, send, and await answer. + * Returned answer is placed in supplied buffer "answer". + * Perform preliminary check of answer, returning success only + * if no error is indicated and the answer count is nonzero. + * Return the size of the response on success, -1 on error. + * Error number is left in h_errno. + * + * Caller must parse answer and determine whether it answers the question. + */ +static int +res_queryN(name, target) + const char *name; /* domain name */ + struct res_target *target; +{ + u_char buf[MAXPACKET]; + HEADER *hp; + int n; + struct res_target *t; + int rcode; + int ancount; + + rcode = NOERROR; + ancount = 0; + + if ((_res.options & RES_INIT) == 0 && res_init() == -1) { + h_errno = NETDB_INTERNAL; + return (-1); + } + + for (t = target; t; t = t->next) { + int class, type; + u_char *answer; + int anslen; + + hp = (HEADER *)(void *)t->answer; + hp->rcode = NOERROR; /* default */ + + /* make it easier... */ + class = t->qclass; + type = t->qtype; + answer = t->answer; + anslen = t->anslen; +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf(";; res_query(%s, %d, %d)\n", name, class, type); +#endif + + n = res_mkquery(QUERY, name, class, type, NULL, 0, NULL, + buf, sizeof(buf)); + if (n > 0 && (_res.options & RES_USE_EDNS0) != 0) + n = res_opt(n, buf, sizeof(buf), anslen); + if (n <= 0) { +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf(";; res_query: mkquery failed\n"); +#endif + h_errno = NO_RECOVERY; + return (n); + } + n = res_send(buf, n, answer, anslen); +#if 0 + if (n < 0) { +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf(";; res_query: send error\n"); +#endif + h_errno = TRY_AGAIN; + return (n); + } +#endif + + if (n < 0 || hp->rcode != NOERROR || ntohs(hp->ancount) == 0) { + rcode = hp->rcode; /* record most recent error */ +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf(";; rcode = %d, ancount=%d\n", hp->rcode, + ntohs(hp->ancount)); +#endif + continue; + } + + ancount += ntohs(hp->ancount); + + t->n = n; + } + + if (ancount == 0) { + switch (rcode) { + case NXDOMAIN: + h_errno = HOST_NOT_FOUND; + break; + case SERVFAIL: + h_errno = TRY_AGAIN; + break; + case NOERROR: + h_errno = NO_DATA; + break; + case FORMERR: + case NOTIMP: + case REFUSED: + default: + h_errno = NO_RECOVERY; + break; + } + return (-1); + } + return (ancount); +} + +/* + * Formulate a normal query, send, and retrieve answer in supplied buffer. + * Return the size of the response on success, -1 on error. + * If enabled, implement search rules until answer or unrecoverable failure + * is detected. Error code, if any, is left in h_errno. + */ +static int +res_searchN(name, target) + const char *name; /* domain name */ + struct res_target *target; +{ + const char *cp, * const *domain; + HEADER *hp = (HEADER *)(void *)target->answer; /*XXX*/ + u_int dots; + int trailing_dot, ret, saved_herrno; + int got_nodata = 0, got_servfail = 0, tried_as_is = 0; + + if ((_res.options & RES_INIT) == 0 && res_init() == -1) { + h_errno = NETDB_INTERNAL; + return (-1); + } + + errno = 0; + h_errno = HOST_NOT_FOUND; /* default, if we never query */ + dots = 0; + for (cp = name; *cp; cp++) + dots += (*cp == '.'); + trailing_dot = 0; + if (cp > name && *--cp == '.') + trailing_dot++; + + /* + * if there aren't any dots, it could be a user-level alias + */ + if (!dots && (cp = __hostalias(name)) != NULL) + return (res_queryN(cp, target)); + + /* + * If there are dots in the name already, let's just give it a try + * 'as is'. The threshold can be set with the "ndots" option. + */ + saved_herrno = -1; + if (dots >= _res.ndots) { + ret = res_querydomainN(name, NULL, target); + if (ret > 0) + return (ret); + saved_herrno = h_errno; + tried_as_is++; + } + + /* + * We do at least one level of search if + * - there is no dot and RES_DEFNAME is set, or + * - there is at least one dot, there is no trailing dot, + * and RES_DNSRCH is set. + */ + if ((!dots && (_res.options & RES_DEFNAMES)) || + (dots && !trailing_dot && (_res.options & RES_DNSRCH))) { + int done = 0; + + for (domain = (const char * const *)_res.dnsrch; + *domain && !done; + domain++) { + + ret = res_querydomainN(name, *domain, target); + if (ret > 0) + return (ret); + + /* + * If no server present, give up. + * If name isn't found in this domain, + * keep trying higher domains in the search list + * (if that's enabled). + * On a NO_DATA error, keep trying, otherwise + * a wildcard entry of another type could keep us + * from finding this entry higher in the domain. + * If we get some other error (negative answer or + * server failure), then stop searching up, + * but try the input name below in case it's + * fully-qualified. + */ + if (errno == ECONNREFUSED) { + h_errno = TRY_AGAIN; + return (-1); + } + + switch (h_errno) { + case NO_DATA: + got_nodata++; + /* FALLTHROUGH */ + case HOST_NOT_FOUND: + /* keep trying */ + break; + case TRY_AGAIN: + if (hp->rcode == SERVFAIL) { + /* try next search element, if any */ + got_servfail++; + break; + } + /* FALLTHROUGH */ + default: + /* anything else implies that we're done */ + done++; + } + /* + * if we got here for some reason other than DNSRCH, + * we only wanted one iteration of the loop, so stop. + */ + if (!(_res.options & RES_DNSRCH)) + done++; + } + } + + /* + * if we have not already tried the name "as is", do that now. + * note that we do this regardless of how many dots were in the + * name or whether it ends with a dot. + */ + if (!tried_as_is && (dots || !(_res.options & RES_NOTLDQUERY))) { + ret = res_querydomainN(name, NULL, target); + if (ret > 0) + return (ret); + } + + /* + * if we got here, we didn't satisfy the search. + * if we did an initial full query, return that query's h_errno + * (note that we wouldn't be here if that query had succeeded). + * else if we ever got a nodata, send that back as the reason. + * else send back meaningless h_errno, that being the one from + * the last DNSRCH we did. + */ + if (saved_herrno != -1) + h_errno = saved_herrno; + else if (got_nodata) + h_errno = NO_DATA; + else if (got_servfail) + h_errno = TRY_AGAIN; + return (-1); +} + +/* + * Perform a call on res_query on the concatenation of name and domain, + * removing a trailing dot from name if domain is NULL. + */ +static int +res_querydomainN(name, domain, target) + const char *name, *domain; + struct res_target *target; +{ + char nbuf[MAXDNAME]; + const char *longname = nbuf; + size_t n, d; + + if ((_res.options & RES_INIT) == 0 && res_init() == -1) { + h_errno = NETDB_INTERNAL; + return (-1); + } +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf(";; res_querydomain(%s, %s)\n", + name, domain?domain:"<Nil>"); +#endif + if (domain == NULL) { + /* + * Check for trailing '.'; + * copy without '.' if present. + */ + n = strlen(name); + if (n >= MAXDNAME) { + h_errno = NO_RECOVERY; + return (-1); + } + if (n > 0 && name[--n] == '.') { + strncpy(nbuf, name, n); + nbuf[n] = '\0'; + } else + longname = name; + } else { + n = strlen(name); + d = strlen(domain); + if (n + d + 1 >= MAXDNAME) { + h_errno = NO_RECOVERY; + return (-1); + } + sprintf(nbuf, "%s.%s", name, domain); + } + return (res_queryN(longname, target)); +} |