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 /*	$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.

  */

 /*

  * This version of getaddrinfo.c is derived from Android 2.3 "Gingerbread",

  * which contains uncredited changes by Android/Google developers.  It has

  * been modified in 2011 for use in the Android build of Mozilla Firefox by

  * Mozilla contributors (including Michael Edwards <m.k.edwards@gmail.com>,

  * and Steve Workman <sjhworkman@gmail.com>).

  * These changes are offered under the same license as the original NetBSD

  * file, whose copyright and license are unchanged above.

  */

 #define ANDROID_CHANGES 1

 #define INET6 1

 /*

  * 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.

  * - 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().

  * - MOZILLA: Thread safeness for pre-Honeycomb Android versions implemented by

  *   way of open/gets/close and mmap rather than fopen/fgets/fclose.  Affects

  *   _files_getaddrinfo for hosts file.  Note: Honeycomb and later versions use

  *   a thread-safe stdio, so for those versions normal Bionic libc getaddrinfo

  *   is used.

  * - 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 <fcntl.h>

 #include <sys/cdefs.h>

 #include <sys/types.h>

 #include <sys/stat.h>

 #include <sys/param.h>

 #include <sys/socket.h>

 #include <sys/un.h>

 #include <sys/mman.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 <stdlib.h>

 #include <string.h>

 #include <unistd.h>

 #include <syslog.h>

 #include <stdarg.h>

 #include "nsswitch.h"

 #ifdef MOZ_GETADDRINFO_LOG_VERBOSE

 #include <android/log.h>

 #endif

 #ifdef ANDROID_CHANGES

 #include <sys/system_properties.h>

 #endif /* ANDROID_CHANGES */

 typedef struct _pseudo_FILE {

     int fd;

     off_t maplen;

     void* mapping;

     off_t offset;

 } _pseudo_FILE;

 #define _PSEUDO_FILE_INITIALIZER { -1, 0, MAP_FAILED, 0 }

 static void

 _pseudo_fclose(_pseudo_FILE * __restrict__ fp)

 {

     assert(fp);

     fp->offset = 0;

     if (fp->mapping != MAP_FAILED) {

         (void) munmap(fp->mapping, fp->maplen);

         fp->mapping = MAP_FAILED;

     }

     fp->maplen = 0;

     if (fp->fd != -1) {

         (void) close(fp->fd);

         fp->fd = -1;

     }

 }

 static _pseudo_FILE *

 _pseudo_fopen_r(_pseudo_FILE * __restrict__ fp, const char* fname)

 {

     struct stat statbuf;

     assert(fp);

     fp->fd = open(fname, O_RDONLY);

     if (fp->fd < 0) {

         fp->fd = -1;

         return NULL;

     }

     if ((0 != fstat(fp->fd, &statbuf)) || (statbuf.st_size <= 0)) {

         close(fp->fd);

         fp->fd = -1;

         return NULL;

     }

     fp->maplen = statbuf.st_size;

     fp->mapping = mmap(NULL, fp->maplen, PROT_READ, MAP_PRIVATE, fp->fd, 0);

     if (fp->mapping == MAP_FAILED) {

         close(fp->fd);

         fp->fd = -1;

         return NULL;

     }

     fp->offset = 0;

     return fp;

 }

 static void

 _pseudo_rewind(_pseudo_FILE * __restrict__ fp)

 {

     assert(fp);

     fp->offset = 0;

 }

 static char*

 _pseudo_fgets(char* buf, int bufsize, _pseudo_FILE * __restrict__ fp)

 {

     char* current;

     char* endp;

     int maxcopy;

     assert(fp);

     maxcopy = fp->maplen - fp->offset;

     if (fp->mapping == MAP_FAILED)

         return NULL;

     if (maxcopy > bufsize - 1)

         maxcopy = bufsize - 1;

     if (maxcopy <= 0)

         return NULL;

     current = ((char*) fp->mapping) + fp->offset;

     endp = memccpy(buf, current, '\n', maxcopy);

     if (endp)

         maxcopy = endp - buf;

     buf[maxcopy] = '\0';

     fp->offset += maxcopy;

     return buf;

 }

 typedef union sockaddr_union {

     struct sockaddr     generic;

     struct sockaddr_in  in;

     struct sockaddr_in6 in6;

 } sockaddr_union;

 #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 int _dns_getaddrinfo(void *, void *, va_list);

 static void _sethtent(_pseudo_FILE * __restrict__);

 static void _endhtent(_pseudo_FILE * __restrict__);

 static struct addrinfo *_gethtent(_pseudo_FILE * __restrict__, 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)))

 #pragma GCC visibility push(default)

 extern const char *

 __wrap_gai_strerror(int ecode);

 extern void

 __wrap_freeaddrinfo(struct addrinfo *ai);

 extern int

 __wrap_getaddrinfo(const char *hostname, const char *servname,

     const struct addrinfo *hints, struct addrinfo **res);

 int android_sdk_version;

 #pragma GCC visibility pop

 int android_sdk_version = -1;

 static int honeycomb_or_later()

 {

 #ifdef MOZ_GETADDRINFO_LOG_VERBOSE

 	__android_log_print(ANDROID_LOG_INFO, "getaddrinfo",

 		"I am%s Honeycomb\n",

 		(android_sdk_version >= 11) ? "" : " not");

 #endif

 	return android_sdk_version >= 11;

 }

 const char *

 __wrap_gai_strerror(int ecode)

 {

 	if (honeycomb_or_later())

 		return gai_strerror(ecode);

 	if (ecode < 0 || ecode > EAI_MAX)

 		ecode = EAI_MAX;

 	return ai_errlist[ecode];

 }

 void

 __wrap_freeaddrinfo(struct addrinfo *ai)

 {

 	struct addrinfo *next;

 	if (honeycomb_or_later()) {

 		freeaddrinfo(ai);

 		return;

 	}

 	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;

 }

 /*

  * Connect a UDP socket to a given unicast address. This will cause no network

  * traffic, but will fail fast if the system has no or limited reachability to

  * the destination (e.g., no IPv4 address, no IPv6 default route, ...).

  */

 static int

 _test_connect(int pf, struct sockaddr *addr, size_t addrlen) {

 	int s = socket(pf, SOCK_DGRAM, IPPROTO_UDP);

 	if (s < 0)

 		return 0;

 	int ret;

 	do {

 		ret = connect(s, addr, addrlen);

 	} while (ret < 0 && errno == EINTR);

 	int success = (ret == 0);

 	do {

 		ret = close(s);

 	} while (ret < 0 && errno == EINTR);

 	return success;

 }

 /*

  * The following functions determine whether IPv4 or IPv6 connectivity is

  * available in order to implement AI_ADDRCONFIG.

  *

  * Strictly speaking, AI_ADDRCONFIG should not look at whether connectivity is

  * available, but whether addresses of the specified family are "configured

  * on the local system". However, bionic doesn't currently support getifaddrs,

  * so checking for connectivity is the next best thing.

  */

 static int

 _have_ipv6() {

 	static const struct sockaddr_in6 sin6_test = {

 		.sin6_family = AF_INET6,

 		.sin6_addr.s6_addr = {  // 2000::

 			0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}

 		};

         sockaddr_union addr = { .in6 = sin6_test };

 	return _test_connect(PF_INET6, &addr.generic, sizeof(addr.in6));

 }

 static int

 _have_ipv4() {

 	static const struct sockaddr_in sin_test = {

 		.sin_family = AF_INET,

 		.sin_addr.s_addr = __constant_htonl(0x08080808L)  // 8.8.8.8

 	};

         sockaddr_union addr = { .in = sin_test };

         return _test_connect(PF_INET, &addr.generic, sizeof(addr.in));

 }

 int

 __wrap_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;

 	if (honeycomb_or_later())

 		return getaddrinfo(hostname, servname, hints, res);

 	/* 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)

 		__wrap_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)

 		__wrap_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)

 		__wrap_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)

 		__wrap_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:

 #if 1  /* ANDROID-SPECIFIC CHANGE TO MATCH GLIBC */

 		allownumeric = 1;

 #else

 		allownumeric = 0;

 #endif

 		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;

 }

 struct addrinfo_sort_elem {

 	struct addrinfo *ai;

 	int has_src_addr;

 	sockaddr_union src_addr;

 	int original_order;

 };

 /*ARGSUSED*/

 static int

 _get_scope(const struct sockaddr *addr)

 {

 	if (addr->sa_family == AF_INET6) {

 		const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr;

 		if (IN6_IS_ADDR_MULTICAST(&addr6->sin6_addr)) {

 			return IPV6_ADDR_MC_SCOPE(&addr6->sin6_addr);

 		} else if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr) ||

 			   IN6_IS_ADDR_LINKLOCAL(&addr6->sin6_addr)) {

 			/*

 			 * RFC 4291 section 2.5.3 says loopback is to be treated as having

 			 * link-local scope.

 			 */

 			return IPV6_ADDR_SCOPE_LINKLOCAL;

 		} else if (IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr)) {

 			return IPV6_ADDR_SCOPE_SITELOCAL;

 		} else {

 			return IPV6_ADDR_SCOPE_GLOBAL;

 		}

 	} else if (addr->sa_family == AF_INET) {

 		const struct sockaddr_in *addr4 = (const struct sockaddr_in *)addr;

 		unsigned long int na = ntohl(addr4->sin_addr.s_addr);

 		if (IN_LOOPBACK(na) ||                          /* 127.0.0.0/8 */

 		    (na & 0xffff0000) == 0xa9fe0000) {          /* 169.254.0.0/16 */

 			return IPV6_ADDR_SCOPE_LINKLOCAL;

 		} else {

 			/*

 			 * According to draft-ietf-6man-rfc3484-revise-01 section 2.3,

 			 * it is best not to treat the private IPv4 ranges

 			 * (10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0/16) as being

 			 * in a special scope, so we don't.

 			 */

 			return IPV6_ADDR_SCOPE_GLOBAL;

 		}

 	} else {

 		/*

 		 * This should never happen.

 		 * Return a scope with low priority as a last resort.

 		 */

 		return IPV6_ADDR_SCOPE_NODELOCAL;

 	}

 }

 /* These macros are modelled after the ones in <netinet/in6.h>. */

 /* RFC 4380, section 2.6 */

 #define IN6_IS_ADDR_TEREDO(a)	 \

 	((*(const uint32_t *)(const void *)(&(a)->s6_addr[0]) == ntohl(0x20010000)))

 /* RFC 3056, section 2. */

 #define IN6_IS_ADDR_6TO4(a)	 \

 	(((a)->s6_addr[0] == 0x20) && ((a)->s6_addr[1] == 0x02))

 /* 6bone testing address area (3ffe::/16), deprecated in RFC 3701. */

 #define IN6_IS_ADDR_6BONE(a)      \

 	(((a)->s6_addr[0] == 0x3f) && ((a)->s6_addr[1] == 0xfe))

 /*

  * Get the label for a given IPv4/IPv6 address.

  * RFC 3484, section 2.1, plus changes from draft-ietf-6man-rfc3484-revise-01.

  */

 /*ARGSUSED*/

 static int

 _get_label(const struct sockaddr *addr)

 {

 	if (addr->sa_family == AF_INET) {

 		return 3;

 	} else if (addr->sa_family == AF_INET6) {

 		const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr;

 		if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr)) {

 			return 0;

 		} else if (IN6_IS_ADDR_V4MAPPED(&addr6->sin6_addr)) {

 			return 3;

 		} else if (IN6_IS_ADDR_6TO4(&addr6->sin6_addr)) {

 			return 4;

 		} else if (IN6_IS_ADDR_TEREDO(&addr6->sin6_addr)) {

 			return 5;

 		} else if (IN6_IS_ADDR_V4COMPAT(&addr6->sin6_addr)) {

 			return 10;

 		} else if (IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr)) {

 			return 11;

 		} else if (IN6_IS_ADDR_6BONE(&addr6->sin6_addr)) {

 			return 12;

 		} else {

 			return 2;

 		}

 	} else {

 		/*

 		 * This should never happen.

 		 * Return a semi-random label as a last resort.

 		 */

 		return 1;

 	}

 }

 /*

  * Get the precedence for a given IPv4/IPv6 address.

  * RFC 3484, section 2.1, plus changes from draft-ietf-6man-rfc3484-revise-01.

  */

 /*ARGSUSED*/

 static int

 _get_precedence(const struct sockaddr *addr)

 {

 	if (addr->sa_family == AF_INET) {

 		return 30;

 	} else if (addr->sa_family == AF_INET6) {

 		const struct sockaddr_in6 *addr6 = (const struct sockaddr_in6 *)addr;

 		if (IN6_IS_ADDR_LOOPBACK(&addr6->sin6_addr)) {

 			return 60;

 		} else if (IN6_IS_ADDR_V4MAPPED(&addr6->sin6_addr)) {

 			return 30;

 		} else if (IN6_IS_ADDR_6TO4(&addr6->sin6_addr)) {

 			return 20;

 		} else if (IN6_IS_ADDR_TEREDO(&addr6->sin6_addr)) {

 			return 10;

 		} else if (IN6_IS_ADDR_V4COMPAT(&addr6->sin6_addr) ||

 		           IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr) ||

 		           IN6_IS_ADDR_6BONE(&addr6->sin6_addr)) {

 			return 1;

 		} else {

 			return 40;

 		}

 	} else {

 		return 1;

 	}

 }

 /*

  * Find number of matching initial bits between the two addresses a1 and a2.

  */

 /*ARGSUSED*/

 static int

 _common_prefix_len(const struct in6_addr *a1, const struct in6_addr *a2)

 {

 	const char *p1 = (const char *)a1;

 	const char *p2 = (const char *)a2;

 	unsigned i;

 	for (i = 0; i < sizeof(*a1); ++i) {

 		int x, j;

 		if (p1[i] == p2[i]) {

 			continue;

 		}

 		x = p1[i] ^ p2[i];

 		for (j = 0; j < CHAR_BIT; ++j) {

 			if (x & (1 << (CHAR_BIT - 1))) {

 				return i * CHAR_BIT + j;

 			}

 			x <<= 1;

 		}

 	}

 	return sizeof(*a1) * CHAR_BIT;

 }

 /*

  * Compare two source/destination address pairs.

  * RFC 3484, section 6.

  */

 /*ARGSUSED*/

 static int

 _rfc3484_compare(const void *ptr1, const void* ptr2)

 {

 	const struct addrinfo_sort_elem *a1 = (const struct addrinfo_sort_elem *)ptr1;

 	const struct addrinfo_sort_elem *a2 = (const struct addrinfo_sort_elem *)ptr2;

 	int scope_src1, scope_dst1, scope_match1;

 	int scope_src2, scope_dst2, scope_match2;

 	int label_src1, label_dst1, label_match1;

 	int label_src2, label_dst2, label_match2;

 	int precedence1, precedence2;

 	int prefixlen1, prefixlen2;

 	/* Rule 1: Avoid unusable destinations. */

 	if (a1->has_src_addr != a2->has_src_addr) {

 		return a2->has_src_addr - a1->has_src_addr;

 	}

 	/* Rule 2: Prefer matching scope. */

 	scope_src1 = _get_scope(&a1->src_addr.generic);

 	scope_dst1 = _get_scope(a1->ai->ai_addr);

 	scope_match1 = (scope_src1 == scope_dst1);

 	scope_src2 = _get_scope(&a2->src_addr.generic);

 	scope_dst2 = _get_scope(a2->ai->ai_addr);

 	scope_match2 = (scope_src2 == scope_dst2);

 	if (scope_match1 != scope_match2) {

 		return scope_match2 - scope_match1;

 	}

 	/*

 	 * Rule 3: Avoid deprecated addresses.

 	 * TODO(sesse): We don't currently have a good way of finding this.

 	 */

 	/*

 	 * Rule 4: Prefer home addresses.

 	 * TODO(sesse): We don't currently have a good way of finding this.

 	 */

 	/* Rule 5: Prefer matching label. */

 	label_src1 = _get_label(&a1->src_addr.generic);

 	label_dst1 = _get_label(a1->ai->ai_addr);

 	label_match1 = (label_src1 == label_dst1);

 	label_src2 = _get_label(&a2->src_addr.generic);

 	label_dst2 = _get_label(a2->ai->ai_addr);

 	label_match2 = (label_src2 == label_dst2);

 	if (label_match1 != label_match2) {

 		return label_match2 - label_match1;

 	}

 	/* Rule 6: Prefer higher precedence. */

 	precedence1 = _get_precedence(a1->ai->ai_addr);

 	precedence2 = _get_precedence(a2->ai->ai_addr);

 	if (precedence1 != precedence2) {

 		return precedence2 - precedence1;

 	}

 	/*

 	 * Rule 7: Prefer native transport.

 	 * TODO(sesse): We don't currently have a good way of finding this.

 	 */

 	/* Rule 8: Prefer smaller scope. */

 	if (scope_dst1 != scope_dst2) {

 		return scope_dst1 - scope_dst2;

 	}

 	/*

 	 * Rule 9: Use longest matching prefix.

          * We implement this for IPv6 only, as the rules in RFC 3484 don't seem

          * to work very well directly applied to IPv4. (glibc uses information from

          * the routing table for a custom IPv4 implementation here.)

 	 */

 	if (a1->has_src_addr && a1->ai->ai_addr->sa_family == AF_INET6 &&

 	    a2->has_src_addr && a2->ai->ai_addr->sa_family == AF_INET6) {

 		const struct sockaddr_in6 *a1_src = &a1->src_addr.in6;

 		const struct sockaddr_in6 *a1_dst = (const struct sockaddr_in6 *)a1->ai->ai_addr;

 		const struct sockaddr_in6 *a2_src = &a2->src_addr.in6;

 		const struct sockaddr_in6 *a2_dst = (const struct sockaddr_in6 *)a2->ai->ai_addr;

 		prefixlen1 = _common_prefix_len(&a1_src->sin6_addr, &a1_dst->sin6_addr);

 		prefixlen2 = _common_prefix_len(&a2_src->sin6_addr, &a2_dst->sin6_addr);

 		if (prefixlen1 != prefixlen2) {

 			return prefixlen2 - prefixlen1;

 		}

 	}

 	/*

 	 * Rule 10: Leave the order unchanged.

 	 * We need this since qsort() is not necessarily stable.

 	 */

 	return a1->original_order - a2->original_order;

 }

 /*

  * Find the source address that will be used if trying to connect to the given

  * address. src_addr must be large enough to hold a struct sockaddr_in6.

  *

  * Returns 1 if a source address was found, 0 if the address is unreachable,

  * and -1 if a fatal error occurred. If 0 or 1, the contents of src_addr are

  * undefined.

  */

 /*ARGSUSED*/

 static int

 _find_src_addr(const struct sockaddr *addr, struct sockaddr *src_addr)

 {

 	int sock;

 	int ret;

 	socklen_t len;

 	switch (addr->sa_family) {

 	case AF_INET:

 		len = sizeof(struct sockaddr_in);

 		break;

 	case AF_INET6:

 		len = sizeof(struct sockaddr_in6);

 		break;

 	default:

 		/* No known usable source address for non-INET families. */

 		return 0;

 	}

 	sock = socket(addr->sa_family, SOCK_DGRAM, IPPROTO_UDP);

 	if (sock == -1) {

 		if (errno == EAFNOSUPPORT) {

 			return 0;

 		} else {

 			return -1;

 		}

 	}

 	do {

 		ret = connect(sock, addr, len);

 	} while (ret == -1 && errno == EINTR);

 	if (ret == -1) {

 		close(sock);

 		return 0;

 	}

 	if (getsockname(sock, src_addr, &len) == -1) {

 		close(sock);

 		return -1;

 	}

 	close(sock);

 	return 1;

 }

 /*

  * Sort the linked list starting at sentinel->ai_next in RFC3484 order.

  * Will leave the list unchanged if an error occurs.

  */

 /*ARGSUSED*/

 static void

 _rfc3484_sort(struct addrinfo *list_sentinel)

 {

 	struct addrinfo *cur;

 	int nelem = 0, i;

 	struct addrinfo_sort_elem *elems;

 	cur = list_sentinel->ai_next;

 	while (cur) {

 		++nelem;

 		cur = cur->ai_next;

 	}

 	elems = (struct addrinfo_sort_elem *)malloc(nelem * sizeof(struct addrinfo_sort_elem));

 	if (elems == NULL) {

 		goto error;

 	}

 	/*

 	 * Convert the linked list to an array that also contains the candidate

 	 * source address for each destination address.

 	 */

 	for (i = 0, cur = list_sentinel->ai_next; i < nelem; ++i, cur = cur->ai_next) {

 		int has_src_addr;

 		assert(cur != NULL);

 		elems[i].ai = cur;

 		elems[i].original_order = i;

 		has_src_addr = _find_src_addr(cur->ai_addr, &elems[i].src_addr.generic);

 		if (has_src_addr == -1) {

 			goto error;

 		}

 		elems[i].has_src_addr = has_src_addr;

 	}

 	/* Sort the addresses, and rearrange the linked list so it matches the sorted order. */

 	qsort((void *)elems, nelem, sizeof(struct addrinfo_sort_elem), _rfc3484_compare);

 	list_sentinel->ai_next = elems[0].ai;

 	for (i = 0; i < nelem - 1; ++i) {

 		elems[i].ai->ai_next = elems[i + 1].ai;

 	}

 	elems[nelem - 1].ai->ai_next = NULL;

 error:

 	free(elems);

 }

 /*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.answer = buf->buf;

 		q.anslen = sizeof(buf->buf);

 		int query_ipv6 = 1, query_ipv4 = 1;

 		if (pai->ai_flags & AI_ADDRCONFIG) {

 			query_ipv6 = _have_ipv6();

 			query_ipv4 = _have_ipv4();

 		}

 		if (query_ipv6) {

 			q.qtype = T_AAAA;

 			if (query_ipv4) {

 				q.next = &q2;

 				q2.name = name;

 				q2.qclass = C_IN;

 				q2.qtype = T_A;

 				q2.answer = buf2->buf;

 				q2.anslen = sizeof(buf2->buf);

 			}

 		} else if (query_ipv4) {

 			q.qtype = T_A;

 		} else {

 			free(buf);

 			free(buf2);

 			return NS_NOTFOUND;

 		}

 		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;

 		}

 	}

 	_rfc3484_sort(&sentinel);

 	__res_put_state(res);

 	*((struct addrinfo **)rv) = sentinel.ai_next;

 	return NS_SUCCESS;

 }

 static void

 _sethtent(_pseudo_FILE * __restrict__ hostf)

 {

 	assert(hostf);

 	if (hostf->mapping == MAP_FAILED)

 		(void) _pseudo_fopen_r(hostf, _PATH_HOSTS);

 	else

 		_pseudo_rewind(hostf);

 }

 static void

 _endhtent(_pseudo_FILE * __restrict__ hostf)

 {

 	assert(hostf);

 	(void) _pseudo_fclose(hostf);

 }

 static struct addrinfo *

 _gethtent(_pseudo_FILE * __restrict__ 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];

 	assert(hostf);

 //	fprintf(stderr, "_gethtent() name = '%s'\n", name);

 	assert(name != NULL);

 	assert(pai != NULL);

 	if (hostf->mapping == MAP_FAILED)

 		(void) _pseudo_fopen_r(hostf, _PATH_HOSTS);

 	if (hostf->mapping == MAP_FAILED)

 		return (NULL);

  again:

 	if (!(p = _pseudo_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 = __wrap_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) {

 				__wrap_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;

 	_pseudo_FILE hostf = _PSEUDO_FILE_INITIALIZER;

 	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);

 }