auto import from //depot/cupcake/@135843
diff --git a/libc/netbsd/net/getaddrinfo.c b/libc/netbsd/net/getaddrinfo.c
new file mode 100644
index 0000000..2dd3d97
--- /dev/null
+++ b/libc/netbsd/net/getaddrinfo.c
@@ -0,0 +1,1792 @@
+/* $NetBSD: getaddrinfo.c,v 1.82 2006/03/25 12:09:40 rpaulo Exp $ */
+/* $KAME: getaddrinfo.c,v 1.29 2000/08/31 17:26:57 itojun Exp $ */
+
+/*
+ * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Issues to be discussed:
+ * - 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.
+ * - IPv4 classful (shortened) form. RFC2553 is silent about it. XNET 5.2
+ * says to use inet_aton() to convert IPv4 numeric to binary (alows
+ * classful form as a result).
+ * current code - disallow classful form for IPv4 (due to use of inet_pton).
+ * - 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.
+ */
+
+#include <sys/cdefs.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 <assert.h>
+#include <ctype.h>
+#include <errno.h>
+#include <netdb.h>
+#include "resolv_private.h"
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <syslog.h>
+#include <stdarg.h>
+#include "nsswitch.h"
+
+#define SUCCESS 0
+#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
+
+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
+ {PF_INET6, sizeof(struct in6_addr),
+ sizeof(struct sockaddr_in6),
+ offsetof(struct sockaddr_in6, sin6_addr),
+ in6_addrany, in6_loopback, 1},
+#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, 0 }
+};
+
+#define MAXPACKET (64*1024)
+
+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 str2number(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 **, 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 int get_portmatch(const struct addrinfo *, const char *);
+static int get_port(const struct addrinfo *, const char *, int);
+static const struct afd *find_afd(int);
+#ifdef INET6
+static int ip6_str2scopeid(char *, struct sockaddr_in6 *, u_int32_t *);
+#endif
+
+static struct addrinfo *getanswer(const querybuf *, int, const char *, int,
+ const struct addrinfo *);
+static void aisort(struct addrinfo *s, res_state res);
+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);
+
+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);
+
+static const char * const ai_errlist[] = {
+ "Success",
+ "Address family for hostname not supported", /* EAI_ADDRFAMILY */
+ "Temporary failure in name resolution", /* EAI_AGAIN */
+ "Invalid value for ai_flags", /* EAI_BADFLAGS */
+ "Non-recoverable failure in name resolution", /* EAI_FAIL */
+ "ai_family not supported", /* EAI_FAMILY */
+ "Memory allocation failure", /* EAI_MEMORY */
+ "No address associated with hostname", /* EAI_NODATA */
+ "hostname nor servname provided, or not known", /* EAI_NONAME */
+ "servname not supported for ai_socktype", /* EAI_SERVICE */
+ "ai_socktype not supported", /* EAI_SOCKTYPE */
+ "System error returned in errno", /* EAI_SYSTEM */
+ "Invalid value for hints", /* EAI_BADHINTS */
+ "Resolved protocol is unknown", /* EAI_PROTOCOL */
+ "Argument buffer overflow", /* EAI_OVERFLOW */
+ "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)))
+
+const char *
+gai_strerror(int ecode)
+{
+ if (ecode < 0 || ecode > EAI_MAX)
+ ecode = EAI_MAX;
+ return ai_errlist[ecode];
+}
+
+void
+freeaddrinfo(struct addrinfo *ai)
+{
+ struct addrinfo *next;
+
+ assert(ai != NULL);
+
+ 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)
+{
+ char *ep;
+ unsigned long v;
+
+ assert(p != NULL);
+
+ if (*p == '\0')
+ return -1;
+ ep = NULL;
+ errno = 0;
+ v = strtoul(p, &ep, 10);
+ if (errno == 0 && ep && *ep == '\0' && v <= UINT_MAX)
+ return v;
+ 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;
+ struct addrinfo ai0;
+ struct addrinfo *pai;
+ const struct explore *ex;
+
+ /* hostname is allowed to be NULL */
+ /* servname is allowed to be NULL */
+ /* hints is allowed to be NULL */
+ assert(res != 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 (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);
+ }
+ }
+ }
+ }
+
+ /*
+ * 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->ai_next)
+ cur = cur->ai_next;
+ }
+
+ /*
+ * XXX
+ * If numeric 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 (hostname == NULL)
+ ERR(EAI_NODATA);
+ if (pai->ai_flags & AI_NUMERICHOST)
+ ERR(EAI_NONAME);
+
+ /*
+ * hostname as alphabetical name.
+ * we would like to prefer AF_INET6 than AF_INET, so we'll make a
+ * outer loop by AFs.
+ */
+ for (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(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, 0, 0 }
+ };
+
+ assert(pai != NULL);
+ /* hostname may be NULL */
+ /* servname may be NULL */
+ assert(res != NULL);
+
+ 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(const struct addrinfo *pai, const char *servname,
+ struct addrinfo **res)
+{
+ int s;
+ const struct afd *afd;
+ struct addrinfo *cur;
+ struct addrinfo sentinel;
+ int error;
+
+ assert(pai != NULL);
+ /* servname may be NULL */
+ assert(res != NULL);
+
+ *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(const struct addrinfo *pai, const char *hostname,
+ const char *servname, struct addrinfo **res, const char *canonname)
+{
+ const struct afd *afd;
+ struct addrinfo *cur;
+ struct addrinfo sentinel;
+ int error;
+ char pton[PTON_MAX];
+
+ assert(pai != NULL);
+ /* hostname may be NULL */
+ /* servname may be NULL */
+ assert(res != NULL);
+
+ *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 0 /*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);
+ if ((pai->ai_flags & AI_CANONNAME)) {
+ /*
+ * Set the numeric address itself as
+ * the canonical name, based on a
+ * clarification in rfc2553bis-03.
+ */
+ GET_CANONNAME(cur->ai_next, canonname);
+ }
+ 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);
+ if ((pai->ai_flags & AI_CANONNAME)) {
+ /*
+ * Set the numeric address itself as
+ * the canonical name, based on a
+ * clarification in rfc2553bis-03.
+ */
+ GET_CANONNAME(cur->ai_next, canonname);
+ }
+ while (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(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;
+
+ assert(pai != NULL);
+ /* hostname may be NULL */
+ /* servname may be NULL */
+ assert(res != NULL);
+
+ /*
+ * 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, 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);
+ return(EAI_NODATA); /* XXX: is return OK? */
+ }
+ sin6->sin6_scope_id = scopeid;
+ }
+ }
+
+ free(hostname2);
+
+ return error;
+#endif
+}
+
+static int
+get_canonname(const struct addrinfo *pai, struct addrinfo *ai, const char *str)
+{
+
+ assert(pai != NULL);
+ assert(ai != NULL);
+ assert(str != NULL);
+
+ 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;
+
+ assert(pai != NULL);
+ assert(afd != NULL);
+ assert(addr != NULL);
+
+ 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);
+
+#ifdef HAVE_SA_LEN
+ ai->ai_addr->sa_len = afd->a_socklen;
+#endif
+
+ ai->ai_addrlen = afd->a_socklen;
+#if defined (__alpha__) || (defined(__i386__) && defined(_LP64)) || defined(__sparc64__)
+ ai->__ai_pad0 = 0;
+#endif
+ ai->ai_addr->sa_family = ai->ai_family = afd->a_af;
+ p = (char *)(void *)(ai->ai_addr);
+ memcpy(p + afd->a_off, addr, (size_t)afd->a_addrlen);
+ return ai;
+}
+
+static int
+get_portmatch(const struct addrinfo *ai, const char *servname)
+{
+
+ assert(ai != NULL);
+ /* servname may be NULL */
+
+ return get_port(ai, servname, 1);
+}
+
+static int
+get_port(const struct addrinfo *ai, const char *servname, int matchonly)
+{
+ const char *proto;
+ struct servent *sp;
+ int port;
+ int allownumeric;
+
+ assert(ai != NULL);
+ /* servname may be NULL */
+
+ 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;
+ }
+
+ port = str2number(servname);
+ if (port >= 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_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(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;
+}
+
+#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;
+
+ assert(scope != NULL);
+ assert(sin6 != NULL);
+ assert(scopeid != NULL);
+
+ 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
+
+/* code duplicate with gethnamaddr.c */
+
+static const char AskedForGot[] =
+ "gethostby*.getanswer: asked for \"%s\", got \"%s\"";
+
+static struct addrinfo *
+getanswer(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, *ep;
+ int type, class, ancount, qdcount;
+ int haveanswer, had_error;
+ char tbuf[MAXDNAME];
+ int (*name_ok) (const char *);
+ char hostbuf[8*1024];
+
+ assert(answer != NULL);
+ assert(qname != NULL);
+ assert(pai != NULL);
+
+ 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) {
+ h_errno = NO_RECOVERY;
+ return (NULL);
+ }
+ n = dn_expand(answer->buf, eom, cp, bp, ep - bp);
+ 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;
+ /* 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, (size_t)(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) {
+ 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));
+ cp += n;
+ continue; /* XXX - had_error++ ? */
+ }
+ switch (type) {
+ case T_A:
+ case T_AAAA:
+ if (strcasecmp(canonname, bp) != 0) {
+ syslog(LOG_NOTICE|LOG_AUTH,
+ AskedForGot, canonname, bp);
+ cp += n;
+ continue; /* XXX - had_error++ ? */
+ }
+ if (type == T_A && n != INADDRSZ) {
+ cp += n;
+ continue;
+ }
+ if (type == T_AAAA && n != IN6ADDRSZ) {
+ cp += n;
+ continue;
+ }
+ if (type == T_AAAA) {
+ struct in6_addr in6;
+ memcpy(&in6, cp, IN6ADDRSZ);
+ if (IN6_IS_ADDR_V4MAPPED(&in6)) {
+ cp += n;
+ continue;
+ }
+ }
+ 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 (!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;
+}
+
+#define SORTEDADDR(p) (((struct sockaddr_in *)(void *)(p->ai_next->ai_addr))->sin_addr.s_addr)
+#define SORTMATCH(p, s) ((SORTEDADDR(p) & (s).mask) == (s).addr.s_addr)
+
+static void
+aisort(struct addrinfo *s, res_state res)
+{
+ struct addrinfo head, *t, *p;
+ int i;
+
+ head.ai_next = NULL;
+ t = &head;
+
+ for (i = 0; i < res->nsort; i++) {
+ p = s;
+ while (p->ai_next) {
+ if ((p->ai_next->ai_family != AF_INET)
+ || SORTMATCH(p, res->sort_list[i])) {
+ t->ai_next = p->ai_next;
+ t = t->ai_next;
+ p->ai_next = p->ai_next->ai_next;
+ } else {
+ p = p->ai_next;
+ }
+ }
+ }
+
+ /* add rest of list and reset s to the new list*/
+ t->ai_next = s->ai_next;
+ s->ai_next = head.ai_next;
+}
+
+/*ARGSUSED*/
+static int
+_dns_getaddrinfo(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;
+ res_state res;
+
+ name = va_arg(ap, char *);
+ pai = va_arg(ap, const struct addrinfo *);
+
+ fprintf(stderr, "_dns_getaddrinfo() name = '%s'\n", name);
+
+ memset(&q, 0, sizeof(q));
+ memset(&q2, 0, sizeof(q2));
+ memset(&sentinel, 0, sizeof(sentinel));
+ cur = &sentinel;
+
+ buf = malloc(sizeof(*buf));
+ if (buf == NULL) {
+ h_errno = NETDB_INTERNAL;
+ return NS_NOTFOUND;
+ }
+ buf2 = malloc(sizeof(*buf2));
+ if (buf2 == NULL) {
+ free(buf);
+ h_errno = NETDB_INTERNAL;
+ return NS_NOTFOUND;
+ }
+
+ switch (pai->ai_family) {
+ case AF_UNSPEC:
+ /* prefer IPv6 */
+ q.name = name;
+ q.qclass = C_IN;
+ q.qtype = T_AAAA;
+ q.answer = buf->buf;
+ q.anslen = sizeof(buf->buf);
+ q.next = &q2;
+ q2.name = name;
+ q2.qclass = C_IN;
+ q2.qtype = T_A;
+ q2.answer = buf2->buf;
+ q2.anslen = sizeof(buf2->buf);
+ break;
+ case AF_INET:
+ q.name = name;
+ q.qclass = C_IN;
+ q.qtype = T_A;
+ q.answer = buf->buf;
+ q.anslen = sizeof(buf->buf);
+ break;
+ case AF_INET6:
+ q.name = name;
+ 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_get_state();
+ if (res == NULL) {
+ free(buf);
+ free(buf2);
+ return NS_NOTFOUND;
+ }
+
+ if (res_searchN(name, &q, res) < 0) {
+ __res_put_state(res);
+ free(buf);
+ free(buf2);
+ 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;
+ }
+ free(buf);
+ free(buf2);
+ if (sentinel.ai_next == NULL) {
+ __res_put_state(res);
+ switch (h_errno) {
+ case HOST_NOT_FOUND:
+ return NS_NOTFOUND;
+ case TRY_AGAIN:
+ return NS_TRYAGAIN;
+ default:
+ return NS_UNAVAIL;
+ }
+ }
+
+ if (res->nsort)
+ aisort(&sentinel, res);
+
+ __res_put_state(res);
+
+ *((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];
+
+// fprintf(stderr, "_gethtent() name = '%s'\n", name);
+ assert(name != NULL);
+ assert(pai != NULL);
+
+ 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;
+ /* if this is not something we're looking for, skip it. */
+ cname = NULL;
+ while (cp && *cp) {
+ if (*cp == ' ' || *cp == '\t') {
+ cp++;
+ continue;
+ }
+ if (!cname)
+ cname = cp;
+ tname = cp;
+ if ((cp = strpbrk(cp, " \t")) != NULL)
+ *cp++ = '\0';
+// fprintf(stderr, "\ttname = '%s'", tname);
+ 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;
+ 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(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 *);
+
+// fprintf(stderr, "_files_getaddrinfo() name = '%s'\n", name);
+ 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;
+}
+
+/* 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, /* domain name */ struct res_target *target,
+ res_state res)
+{
+ u_char buf[MAXPACKET];
+ HEADER *hp;
+ int n;
+ struct res_target *t;
+ int rcode;
+ int ancount;
+
+ assert(name != NULL);
+ /* XXX: target may be NULL??? */
+
+ rcode = NOERROR;
+ ancount = 0;
+
+ 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_nquery(%s, %d, %d)\n", name, class, type);
+#endif
+
+ n = res_nmkquery(res, QUERY, name, class, type, NULL, 0, NULL,
+ buf, sizeof(buf));
+#ifdef RES_USE_EDNS0
+ if (n > 0 && (res->options & RES_USE_EDNS0) != 0)
+ n = res_nopt(res, n, buf, sizeof(buf), anslen);
+#endif
+ if (n <= 0) {
+#ifdef DEBUG
+ if (res->options & RES_DEBUG)
+ printf(";; res_nquery: mkquery failed\n");
+#endif
+ h_errno = NO_RECOVERY;
+ return n;
+ }
+ n = res_nsend(res, 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 = %u, ancount=%u\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(const char *name, struct res_target *target, res_state res)
+{
+ const char *cp, * const *domain;
+ HEADER *hp;
+ u_int dots;
+ int trailing_dot, ret, saved_herrno;
+ int got_nodata = 0, got_servfail = 0, tried_as_is = 0;
+
+ assert(name != NULL);
+ assert(target != NULL);
+
+ hp = (HEADER *)(void *)target->answer; /*XXX*/
+
+ 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++;
+
+
+fprintf(stderr, "res_searchN() name = '%s'\n", name);
+
+ /*
+ * if there aren't any dots, it could be a user-level alias
+ */
+ if (!dots && (cp = __hostalias(name)) != NULL) {
+ ret = res_queryN(cp, target, res);
+ return ret;
+ }
+
+ /*
+ * 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, res);
+ 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, 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) {
+ 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) {
+ 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.
+ */
+ 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(const char *name, const char *domain,
+ struct res_target *target, res_state res)
+{
+ char nbuf[MAXDNAME];
+ const char *longname = nbuf;
+ size_t n, d;
+
+ assert(name != NULL);
+ /* XXX: target may be NULL??? */
+
+#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 + 1 > sizeof(nbuf)) {
+ 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 + 1 + d + 1 > sizeof(nbuf)) {
+ h_errno = NO_RECOVERY;
+ return -1;
+ }
+ snprintf(nbuf, sizeof(nbuf), "%s.%s", name, domain);
+ }
+ return res_queryN(longname, target, res);
+}