diff options
Diffstat (limited to 'lib/libc/net/getaddrinfo.c')
-rw-r--r-- | lib/libc/net/getaddrinfo.c | 2848 |
1 files changed, 2848 insertions, 0 deletions
diff --git a/lib/libc/net/getaddrinfo.c b/lib/libc/net/getaddrinfo.c new file mode 100644 index 0000000..830e464 --- /dev/null +++ b/lib/libc/net/getaddrinfo.c @@ -0,0 +1,2848 @@ +/* $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: + * - Return values. There are nonstandard return values defined and used + * in the source code. This is because RFC2553 is silent about which error + * code must be returned for which situation. + * - freeaddrinfo(NULL). RFC2553 is silent about it. XNET 5.2 says it is + * invalid. current code - SEGV on freeaddrinfo(NULL) + * + * Note: + * - The code filters out AFs that are not supported by the kernel, + * when globbing NULL hostname (to loopback, or wildcard). Is it the right + * thing to do? What is the relationship with post-RFC2553 AI_ADDRCONFIG + * in ai_flags? + * - (post-2553) semantics of AI_ADDRCONFIG itself is too vague. + * (1) what should we do against numeric hostname (2) what should we do + * against NULL hostname (3) what is AI_ADDRCONFIG itself. AF not ready? + * non-loopback address configured? global address configured? + * + * OS specific notes for freebsd4: + * - FreeBSD supported $GAI. The code does not. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include "namespace.h" +#include <sys/types.h> +#include <sys/param.h> +#include <sys/socket.h> +#include <net/if.h> +#include <netinet/in.h> +#include <sys/queue.h> +#ifdef INET6 +#include <net/if_var.h> +#include <sys/sysctl.h> +#include <sys/ioctl.h> +#include <netinet6/in6_var.h> /* XXX */ +#endif +#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> + +#include "res_config.h" + +#ifdef DEBUG +#include <syslog.h> +#endif + +#include <stdarg.h> +#include <nsswitch.h> +#include "un-namespace.h" +#include "libc_private.h" +#ifdef NS_CACHING +#include "nscache.h" +#endif + +#if defined(__KAME__) && defined(INET6) +# define FAITH +#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 +#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, 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_STREAM, IPPROTO_SCTP, "sctp", 0x03 }, + { PF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, "sctp", 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_STREAM, IPPROTO_SCTP, "sctp", 0x03 }, + { PF_INET, SOCK_SEQPACKET, IPPROTO_SCTP, "sctp", 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 + +#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; +}; + +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 *); +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; + + 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 +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[sizeof(afdl)/sizeof(afdl[0])]; + 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_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); + } + } + + /* + * 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. + * 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 = malloc(sizeof(*aio) * n)) == NULL) + return(n); /* give up reordering */ + memset(aio, 0, sizeof(*aio) * n); + + /* 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); + } + + /* 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, sizeof(mib) / sizeof(mib[0]), NULL, &l, NULL, 0) < 0) + return (0); + if ((buf = malloc(l)) == NULL) + return (0); + if (sysctl(mib, sizeof(mib) / sizeof(mib[0]), 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); + key.sin6_addr.s6_addr[10] = 0xff; + key.sin6_addr.s6_addr[11] = 0xff; + memcpy(&key.sin6_addr.s6_addr[12], + &((struct sockaddr_in *)addr)->sin_addr, 4); + 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, ai.ai_protocol)) < 0) + return; /* give up */ + 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; + + /* XXX: interface name should not be hardcoded */ + strncpy(ifr6.ifr_name, "lo0", sizeof(ifr6.ifr_name)); + 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 < addrlen * 8) { + 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) { + 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. */ + 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; + + /* + * 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); + + 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; + int error; + char pton[PTON_MAX]; + + *res = NULL; + ai = NULL; + + afd = find_afd(pai->ai_family); + if (afd == NULL) + return 0; + + switch (afd->a_af) { + 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; + break; + default: + if (inet_pton(afd->a_af, hostname, pton) != 1) + return 0; + break; + } + + if (pai->ai_family == afd->a_af) { + GET_AI(ai, afd, pton); + GET_PORT(ai, servname); + if ((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 <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, 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 FAITH + struct in6_addr faith_prefix; + char *fp_str; + int translate = 0; +#endif + +#ifdef FAITH + /* + * Transfrom an IPv4 addr into a special IPv6 addr format for + * IPv6->IPv4 translation gateway. (only TCP is supported now) + * + * +-----------------------------------+------------+ + * | faith prefix part (12 bytes) | embedded | + * | | IPv4 addr part (4 bytes) + * +-----------------------------------+------------+ + * + * faith prefix part is specified as ascii IPv6 addr format + * in environmental variable GAI. + * For FAITH to work correctly, routing to faith prefix must be + * setup toward a machine where a FAITH daemon operates. + * Also, the machine must enable some mechanizm + * (e.g. faith interface hack) to divert those packet with + * faith prefixed destination addr to user-land FAITH daemon. + */ + fp_str = getenv("GAI"); + if (fp_str && inet_pton(AF_INET6, fp_str, &faith_prefix) == 1 && + afd->a_af == AF_INET && pai->ai_socktype == SOCK_STREAM) { + u_int32_t v4a; + u_int8_t v4a_top; + + memcpy(&v4a, addr, sizeof v4a); + v4a_top = v4a >> IN_CLASSA_NSHIFT; + if (!IN_MULTICAST(v4a) && !IN_EXPERIMENTAL(v4a) && + v4a_top != 0 && v4a != IN_LOOPBACKNET) { + afd = &afdl[N_INET6]; + memcpy(&faith_prefix.s6_addr[12], addr, + sizeof(struct in_addr)); + translate = 1; + } + } +#endif + + ai = (struct addrinfo *)malloc(sizeof(struct addrinfo) + + (afd->a_socklen)); + if (ai == NULL) + return NULL; + + memcpy(ai, pai, sizeof(struct addrinfo)); + ai->ai_addr = (struct sockaddr *)(void *)(ai + 1); + memset(ai->ai_addr, 0, (size_t)afd->a_socklen); + ai->ai_addr->sa_len = afd->a_socklen; + ai->ai_addrlen = afd->a_socklen; + ai->ai_addr->sa_family = ai->ai_family = afd->a_af; + p = (char *)(void *)(ai->ai_addr); +#ifdef FAITH + if (translate == 1) + memcpy(p + afd->a_off, &faith_prefix, (size_t)afd->a_addrlen); + else +#endif + memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen); + return ai; +} + +/* 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 = (struct addrinfo *)malloc(l)) == NULL) + return NULL; + memset(ai, 0, l); + 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_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; + 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; +} + +/* + * 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(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(char *scope, struct sockaddr_in6 *sin6, u_int32_t *scopeid) +{ + u_long lscopeid; + struct in6_addr *a6; + char *ep; + + a6 = &sin6->sin6_addr; + + /* empty scopeid portion is invalid */ + if (*scope == '\0') + return -1; + + if (IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) { + /* + * We currently assume a one-to-one mapping between links + * and interfaces, so we simply use interface indices for + * like-local scopes. + */ + *scopeid = if_nametoindex(scope); + if (*scopeid == 0) + goto trynumeric; + return 0; + } + + /* still unclear about literal, allow numeric only - placeholder */ + if (IN6_IS_ADDR_SITELOCAL(a6) || IN6_IS_ADDR_MC_SITELOCAL(a6)) + goto trynumeric; + if (IN6_IS_ADDR_MC_ORGLOCAL(a6)) + goto trynumeric; + else + goto trynumeric; /* global */ + + /* try to convert to a numeric id as a last resort */ + trynumeric: + errno = 0; + lscopeid = strtoul(scope, &ep, 10); + *scopeid = (u_int32_t)(lscopeid & 0xffffffffUL); + if (errno == 0 && ep && *ep == '\0' && *scopeid == lscopeid) + return 0; + else + return -1; +} +#endif + + +#ifdef 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 = (struct addrinfo *)malloc(size); + memset(sentinel, 0, 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 = (char *)malloc(size + 1); + memset(sentinel->ai_canonname, 0, 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; + } + + RES_SET_H_ERRNO(res, 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; + querybuf *buf, *buf2; + const char *hostname; + const struct addrinfo *pai; + struct addrinfo sentinel, *cur; + struct res_target q, q2; + res_state res; + + 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; + + 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; + } + + 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; + } + + res = __res_state(); + 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) { + cur->ai_next = ai; + while (cur && cur->ai_next) + cur = cur->ai_next; + } + } + ai = getanswer(buf, q.n, q.name, q.qtype, pai, res); + if (ai) + cur->ai_next = ai; + free(buf); + free(buf2); + if (sentinel.ai_next == NULL) + switch (res->res_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(FILE **hostf) +{ + if (!*hostf) + *hostf = fopen(_PATH_HOSTS, "r"); + 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, "r"))) + 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; + error = getaddrinfo(addr, "0", &hints, &res0); + if (error) + goto again; +#ifdef FILTER_V4MAPPED + /* XXX should check all items in the chain */ + if (res0->ai_family == AF_INET6 && + IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)res0->ai_addr)->sin6_addr)) { + freeaddrinfo(res0); + goto again; + } +#endif + for (res = res0; res; res = res->ai_next) { + /* cover it up */ + res->ai_flags = pai->ai_flags; + res->ai_socktype = pai->ai_socktype; + res->ai_protocol = pai->ai_protocol; + + if (pai->ai_flags & AI_CANONNAME) { + if (get_canonname(pai, res, cname) != 0) { + freeaddrinfo(res0); + goto again; + } + } + } + return res0; +} + +/*ARGSUSED*/ +static int +_files_getaddrinfo(void *rv, void *cb_data, va_list ap) +{ + const char *name; + const struct addrinfo *pai; + struct addrinfo sentinel, *cur; + struct addrinfo *p; + FILE *hostf = NULL; + + name = va_arg(ap, char *); + pai = va_arg(ap, struct addrinfo *); + + memset(&sentinel, 0, sizeof(sentinel)); + cur = &sentinel; + + _sethtent(&hostf); + while ((p = _gethtent(&hostf, name, pai)) != NULL) { + cur->ai_next = p; + while (cur && cur->ai_next) + cur = cur->ai_next; + } + _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; + 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; + + /* 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), &ypbuf, &ypbuflen); + if (r == 0) { + struct addrinfo ai4; + + ai4 = *pai; + 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); + } + } + + /* 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; + free(ypbuf); + } + + 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:"<Nil>"); +#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)); +} |