ap/libc/glibc/glibc-2.23/resolv/res_init.c - T106_DC - Gitiles

 /*
  * Copyright (c) 1985, 1989, 1993
  *    The Regents of the University of California.  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.
  * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
  */

 /*
  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies, and that
  * the name of Digital Equipment Corporation not be used in advertising or
  * publicity pertaining to distribution of the document or software without
  * specific, written prior permission.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  * SOFTWARE.
  */

 /*
  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
  * copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
  * SOFTWARE.
  */

 #if defined(LIBC_SCCS) && !defined(lint)
 static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
 static const char rcsid[] = "$BINDId: res_init.c,v 8.16 2000/05/09 07:10:12 vixie Exp $";
 #endif /* LIBC_SCCS and not lint */

 #include <ctype.h>
 #include <netdb.h>
 #include <resolv.h>
 #include <stdio.h>
 #include <stdio_ext.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <stdint.h>
 #include <arpa/inet.h>
 #include <arpa/nameser.h>
 #include <net/if.h>
 #include <netinet/in.h>
 #include <sys/param.h>
 #include <sys/socket.h>
 #include <sys/time.h>
 #include <sys/types.h>

 #include <not-cancel.h>

 /* Options.  Should all be left alone. */
 #define RESOLVSORT
 #define RFC1535
 /* #undef DEBUG */

 static void res_setoptions (res_state, const char *, const char *)
      internal_function;

 #ifdef RESOLVSORT
 static const char sort_mask_chars[] = "/&";
 #define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL)
 static u_int32_t net_mask (struct in_addr) __THROW;
 #endif

 #if !defined(isascii)	/* XXX - could be a function */
 # define isascii(c) (!(c & 0200))
 #endif

 #ifdef _LIBC
 unsigned long long int __res_initstamp attribute_hidden;
 #endif

 /*
  * Resolver state default settings.
  */

 /*
  * Set up default settings.  If the configuration file exist, the values
  * there will have precedence.  Otherwise, the server address is set to
  * INADDR_ANY and the default domain name comes from the gethostname().
  *
  * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
  * rather than INADDR_ANY ("0.0.0.0") as the default name server address
  * since it was noted that INADDR_ANY actually meant ``the first interface
  * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
  * it had to be "up" in order for you to reach your own name server.  It
  * was later decided that since the recommended practice is to always
  * install local static routes through 127.0.0.1 for all your network
  * interfaces, that we could solve this problem without a code change.
  *
  * The configuration file should always be used, since it is the only way
  * to specify a default domain.  If you are running a server on your local
  * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
  * in the configuration file.
  *
  * Return 0 if completes successfully, -1 on error
  */
 int
 res_ninit(res_state statp) {
 	extern int __res_vinit(res_state, int);

 	return (__res_vinit(statp, 0));
 }
 #ifdef _LIBC
 libc_hidden_def (__res_ninit)
 #endif

 /* This function has to be reachable by res_data.c but not publically. */
 int
 __res_vinit(res_state statp, int preinit) {
 	FILE *fp;
 	char *cp, **pp;
 	int n;
 	char buf[BUFSIZ];
 	int nserv = 0;    /* number of nameservers read from file */
 	int have_serv6 = 0;
 	int haveenv = 0;
 	int havesearch = 0;
 #ifdef RESOLVSORT
 	int nsort = 0;
 	char *net;
 #endif
 #ifndef RFC1535
 	int dots;
 #endif
 #ifdef _LIBC
 	statp->_u._ext.initstamp = __res_initstamp;
 #endif

 	if (!preinit) {
 		statp->retrans = RES_TIMEOUT;
 		statp->retry = RES_DFLRETRY;
 		statp->options = RES_DEFAULT;
 		statp->id = res_randomid();
 	}

 	statp->nscount = 0;
 	statp->defdname[0] = '\0';
 	statp->ndots = 1;
 	statp->pfcode = 0;
 	statp->_vcsock = -1;
 	statp->_flags = 0;
 	statp->qhook = NULL;
 	statp->rhook = NULL;
 	statp->_u._ext.nscount = 0;
 	for (n = 0; n < MAXNS; n++)
 	    statp->_u._ext.nsaddrs[n] = NULL;

 	/* Allow user to override the local domain definition */
 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
 		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 		haveenv++;

 		/*
 		 * Set search list to be blank-separated strings
 		 * from rest of env value.  Permits users of LOCALDOMAIN
 		 * to still have a search list, and anyone to set the
 		 * one that they want to use as an individual (even more
 		 * important now that the rfc1535 stuff restricts searches)
 		 */
 		cp = statp->defdname;
 		pp = statp->dnsrch;
 		*pp++ = cp;
 		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 			if (*cp == '\n')	/* silly backwards compat */
 				break;
 			else if (*cp == ' ' || *cp == '\t') {
 				*cp = 0;
 				n = 1;
 			} else if (n) {
 				*pp++ = cp;
 				n = 0;
 				havesearch = 1;
 			}
 		}
 		/* null terminate last domain if there are excess */
 		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
 			cp++;
 		*cp = '\0';
 		*pp++ = 0;
 	}

 #define	MATCH(line, name) \
 	(!strncmp(line, name, sizeof(name) - 1) && \
 	(line[sizeof(name) - 1] == ' ' || \
 	 line[sizeof(name) - 1] == '\t'))

 	if ((fp = fopen(_PATH_RESCONF, "rce")) != NULL) {
 	    /* No threads use this stream.  */
 	    __fsetlocking (fp, FSETLOCKING_BYCALLER);
 	    /* read the config file */
 	    while (__fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
 		/* skip comments */
 		if (*buf == ';' || *buf == '#')
 			continue;
 		/* read default domain name */
 		if (MATCH(buf, "domain")) {
 		    if (haveenv)	/* skip if have from environ */
 			    continue;
 		    cp = buf + sizeof("domain") - 1;
 		    while (*cp == ' ' || *cp == '\t')
 			    cp++;
 		    if ((*cp == '\0') || (*cp == '\n'))
 			    continue;
 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
 			    *cp = '\0';
 		    havesearch = 0;
 		    continue;
 		}
 		/* set search list */
 		if (MATCH(buf, "search")) {
 		    if (haveenv)	/* skip if have from environ */
 			    continue;
 		    cp = buf + sizeof("search") - 1;
 		    while (*cp == ' ' || *cp == '\t')
 			    cp++;
 		    if ((*cp == '\0') || (*cp == '\n'))
 			    continue;
 		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
 		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
 		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
 			    *cp = '\0';
 		    /*
 		     * Set search list to be blank-separated strings
 		     * on rest of line.
 		     */
 		    cp = statp->defdname;
 		    pp = statp->dnsrch;
 		    *pp++ = cp;
 		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
 			    if (*cp == ' ' || *cp == '\t') {
 				    *cp = 0;
 				    n = 1;
 			    } else if (n) {
 				    *pp++ = cp;
 				    n = 0;
 			    }
 		    }
 		    /* null terminate last domain if there are excess */
 		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
 			    cp++;
 		    *cp = '\0';
 		    *pp++ = 0;
 		    havesearch = 1;
 		    continue;
 		}
 		/* read nameservers to query */
 		if (MATCH(buf, "nameserver") && nserv < MAXNS) {
 		    struct in_addr a;

 		    cp = buf + sizeof("nameserver") - 1;
 		    while (*cp == ' ' || *cp == '\t')
 			cp++;
 		    if ((*cp != '\0') && (*cp != '\n')
 			&& __inet_aton(cp, &a)) {
 			statp->nsaddr_list[nserv].sin_addr = a;
 			statp->nsaddr_list[nserv].sin_family = AF_INET;
 			statp->nsaddr_list[nserv].sin_port =
 				htons(NAMESERVER_PORT);
 			nserv++;
 #ifdef _LIBC
 		    } else {
 			struct in6_addr a6;
 			char *el;

 			if ((el = strpbrk(cp, " \t\n")) != NULL)
 			    *el = '\0';
 			if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL)
 			    *el = '\0';
 			if ((*cp != '\0') &&
 			    (__inet_pton(AF_INET6, cp, &a6) > 0)) {
 			    struct sockaddr_in6 *sa6;

 			    sa6 = malloc(sizeof(*sa6));
 			    if (sa6 != NULL) {
 				sa6->sin6_family = AF_INET6;
 				sa6->sin6_port = htons(NAMESERVER_PORT);
 				sa6->sin6_flowinfo = 0;
 				sa6->sin6_addr = a6;

 				if (__glibc_likely (el == NULL))
 				    sa6->sin6_scope_id = 0;
 				else {
 				    int try_numericscope = 1;
 				    if (IN6_IS_ADDR_LINKLOCAL (&a6)
 					|| IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
 					sa6->sin6_scope_id
 					  = __if_nametoindex (el + 1);
 					if (sa6->sin6_scope_id != 0)
 					    try_numericscope = 0;
 				    }

 				    if (try_numericscope) {
 					char *end;
 					sa6->sin6_scope_id
 					  = (uint32_t) strtoul (el + 1, &end,
 								10);
 					if (*end != '\0')
 					    sa6->sin6_scope_id = 0;
 				    }
 				}

 				statp->nsaddr_list[nserv].sin_family = 0;
 				statp->_u._ext.nsaddrs[nserv] = sa6;
 				statp->_u._ext.nssocks[nserv] = -1;
 				have_serv6 = 1;
 				nserv++;
 			    }
 			}
 #endif
 		    }
 		    continue;
 		}
 #ifdef RESOLVSORT
 		if (MATCH(buf, "sortlist")) {
 		    struct in_addr a;

 		    cp = buf + sizeof("sortlist") - 1;
 		    while (nsort < MAXRESOLVSORT) {
 			while (*cp == ' ' || *cp == '\t')
 			    cp++;
 			if (*cp == '\0' || *cp == '\n' || *cp == ';')
 			    break;
 			net = cp;
 			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
 			       isascii(*cp) && !isspace(*cp))
 				cp++;
 			n = *cp;
 			*cp = 0;
 			if (__inet_aton(net, &a)) {
 			    statp->sort_list[nsort].addr = a;
 			    if (ISSORTMASK(n)) {
 				*cp++ = n;
 				net = cp;
 				while (*cp && *cp != ';' &&
 					isascii(*cp) && !isspace(*cp))
 				    cp++;
 				n = *cp;
 				*cp = 0;
 				if (__inet_aton(net, &a)) {
 				    statp->sort_list[nsort].mask = a.s_addr;
 				} else {
 				    statp->sort_list[nsort].mask =
 					net_mask(statp->sort_list[nsort].addr);
 				}
 			    } else {
 				statp->sort_list[nsort].mask =
 				    net_mask(statp->sort_list[nsort].addr);
 			    }
 			    nsort++;
 			}
 			*cp = n;
 		    }
 		    continue;
 		}
 #endif
 		if (MATCH(buf, "options")) {
 		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
 		    continue;
 		}
 	    }
 	    statp->nscount = nserv;
 #ifdef _LIBC
 	    if (have_serv6) {
 		/* We try IPv6 servers again.  */
 		statp->ipv6_unavail = false;
 	    }
 #endif
 #ifdef RESOLVSORT
 	    statp->nsort = nsort;
 #endif
 	    (void) fclose(fp);
 	}
 	if (__builtin_expect(statp->nscount == 0, 0)) {
 	    statp->nsaddr.sin_addr = __inet_makeaddr(IN_LOOPBACKNET, 1);
 	    statp->nsaddr.sin_family = AF_INET;
 	    statp->nsaddr.sin_port = htons(NAMESERVER_PORT);
 	    statp->nscount = 1;
 	}
 	if (statp->defdname[0] == 0 &&
 	    __gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
 	    (cp = strchr(buf, '.')) != NULL)
 		strcpy(statp->defdname, cp + 1);

 	/* find components of local domain that might be searched */
 	if (havesearch == 0) {
 		pp = statp->dnsrch;
 		*pp++ = statp->defdname;
 		*pp = NULL;

 #ifndef RFC1535
 		dots = 0;
 		for (cp = statp->defdname; *cp; cp++)
 			dots += (*cp == '.');

 		cp = statp->defdname;
 		while (pp < statp->dnsrch + MAXDFLSRCH) {
 			if (dots < LOCALDOMAINPARTS)
 				break;
 			cp = __rawmemchr(cp, '.') + 1;    /* we know there is one */
 			*pp++ = cp;
 			dots--;
 		}
 		*pp = NULL;
 #ifdef DEBUG
 		if (statp->options & RES_DEBUG) {
 			printf(";; res_init()... default dnsrch list:\n");
 			for (pp = statp->dnsrch; *pp; pp++)
 				printf(";;\t%s\n", *pp);
 			printf(";;\t..END..\n");
 		}
 #endif
 #endif /* !RFC1535 */
 	}

 	if ((cp = getenv("RES_OPTIONS")) != NULL)
 		res_setoptions(statp, cp, "env");
 	statp->options |= RES_INIT;
 	return (0);
 }

 static void
 internal_function
 res_setoptions(res_state statp, const char *options, const char *source) {
 	const char *cp = options;
 	int i;

 #ifdef DEBUG
 	if (statp->options & RES_DEBUG)
 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
 		       options, source);
 #endif
 	while (*cp) {
 		/* skip leading and inner runs of spaces */
 		while (*cp == ' ' || *cp == '\t')
 			cp++;
 		/* search for and process individual options */
 		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
 			i = atoi(cp + sizeof("ndots:") - 1);
 			if (i <= RES_MAXNDOTS)
 				statp->ndots = i;
 			else
 				statp->ndots = RES_MAXNDOTS;
 #ifdef DEBUG
 			if (statp->options & RES_DEBUG)
 				printf(";;\tndots=%d\n", statp->ndots);
 #endif
 		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
 			i = atoi(cp + sizeof("timeout:") - 1);
 			if (i <= RES_MAXRETRANS)
 				statp->retrans = i;
 			else
 				statp->retrans = RES_MAXRETRANS;
 		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
 			i = atoi(cp + sizeof("attempts:") - 1);
 			if (i <= RES_MAXRETRY)
 				statp->retry = i;
 			else
 				statp->retry = RES_MAXRETRY;
 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
 #ifdef DEBUG
 			if (!(statp->options & RES_DEBUG)) {
 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
 				       options, source);
 				statp->options |= RES_DEBUG;
 			}
 			printf(";;\tdebug\n");
 #endif
 		} else {
 		  static const struct
 		  {
 		    char str[22];
 		    uint8_t len;
 		    uint8_t clear;
 		    unsigned long int flag;
 		  } options[] = {
 #define STRnLEN(str) str, sizeof (str) - 1
 		    { STRnLEN ("inet6"), 0, RES_USE_INET6 },
 		    { STRnLEN ("ip6-bytestring"), 0, RES_USEBSTRING },
 		    { STRnLEN ("no-ip6-dotint"), 0, RES_NOIP6DOTINT },
 		    { STRnLEN ("ip6-dotint"), 1, ~RES_NOIP6DOTINT },
 		    { STRnLEN ("rotate"), 0, RES_ROTATE },
 		    { STRnLEN ("no-check-names"), 0, RES_NOCHECKNAME },
 		    { STRnLEN ("edns0"), 0, RES_USE_EDNS0 },
 		    { STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP },
 		    { STRnLEN ("single-request"), 0, RES_SNGLKUP },
 		    { STRnLEN ("no_tld_query"), 0, RES_NOTLDQUERY },
 		    { STRnLEN ("no-tld-query"), 0, RES_NOTLDQUERY },
 		    { STRnLEN ("use-vc"), 0, RES_USEVC }
 		  };
 #define noptions (sizeof (options) / sizeof (options[0]))
 		  int i;
 		  for (i = 0; i < noptions; ++i)
 		    if (strncmp (cp, options[i].str, options[i].len) == 0)
 		      {
 			if (options[i].clear)
 			  statp->options &= options[i].flag;
 			else
 			  statp->options |= options[i].flag;
 			break;
 		      }
 		  if (i == noptions) {
 		    /* XXX - print a warning here? */
 		  }
 		}
 		/* skip to next run of spaces */
 		while (*cp && *cp != ' ' && *cp != '\t')
 			cp++;
 	}
 }

 #ifdef RESOLVSORT
 /* XXX - should really support CIDR which means explicit masks always. */
 /* XXX - should really use system's version of this */
 static u_int32_t
 net_mask (struct in_addr in)
 {
 	u_int32_t i = ntohl(in.s_addr);

 	if (IN_CLASSA(i))
 		return (htonl(IN_CLASSA_NET));
 	else if (IN_CLASSB(i))
 		return (htonl(IN_CLASSB_NET));
 	return (htonl(IN_CLASSC_NET));
 }
 #endif

 u_int
 res_randomid(void) {
 	return 0xffff & __getpid();
 }
 #ifdef _LIBC
 libc_hidden_def (__res_randomid)
 #endif


 /*
  * This routine is for closing the socket if a virtual circuit is used and
  * the program wants to close it.  This provides support for endhostent()
  * which expects to close the socket.
  *
  * This routine is not expected to be user visible.
  */
 void
 __res_iclose(res_state statp, bool free_addr) {
 	int ns;

 	if (statp->_vcsock >= 0) {
 		close_not_cancel_no_status(statp->_vcsock);
 		statp->_vcsock = -1;
 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
 	}
 	for (ns = 0; ns < statp->_u._ext.nscount; ns++)
 		if (statp->_u._ext.nsaddrs[ns]) {
 			if (statp->_u._ext.nssocks[ns] != -1) {
 				close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
 				statp->_u._ext.nssocks[ns] = -1;
 			}
 			if (free_addr) {
 				free (statp->_u._ext.nsaddrs[ns]);
 				statp->_u._ext.nsaddrs[ns] = NULL;
 			}
 		}
 }
 libc_hidden_def (__res_iclose)

 void
 res_nclose(res_state statp)
 {
   __res_iclose (statp, true);
 }
 #ifdef _LIBC
 libc_hidden_def (__res_nclose)
 #endif

 #ifdef _LIBC
 # ifdef _LIBC_REENTRANT
 /* This is called when a thread is exiting to free resources held in _res.  */
 static void __attribute__ ((section ("__libc_thread_freeres_fn")))
 res_thread_freeres (void)
 {
   if (_res.nscount == 0)
     /* Never called res_ninit.  */
     return;

   __res_iclose (&_res, true);		/* Close any VC sockets.  */

   /* Make sure we do a full re-initialization the next time.  */
   _res.options = 0;
 }
 text_set_element (__libc_thread_subfreeres, res_thread_freeres);
 text_set_element (__libc_subfreeres, res_thread_freeres);
 # endif
 #endif
	/*
	* Copyright (c) 1985, 1989, 1993
	* The Regents of the University of California. 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.
	* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
	*/

	/*
	* Portions Copyright (c) 1993 by Digital Equipment Corporation.
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies, and that
	* the name of Digital Equipment Corporation not be used in advertising or
	* publicity pertaining to distribution of the document or software without
	* specific, written prior permission.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
	* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
	* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	* SOFTWARE.
	*/

	/*
	* Portions Copyright (c) 1996-1999 by Internet Software Consortium.
	*
	* Permission to use, copy, modify, and distribute this software for any
	* purpose with or without fee is hereby granted, provided that the above
	* copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
	* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
	* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	* SOFTWARE.
	*/

	#if defined(LIBC_SCCS) && !defined(lint)
	static const char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
	static const char rcsid[] = "$BINDId: res_init.c,v 8.16 2000/05/09 07:10:12 vixie Exp $";
	#endif /* LIBC_SCCS and not lint */

	#include <ctype.h>
	#include <netdb.h>
	#include <resolv.h>
	#include <stdio.h>
	#include <stdio_ext.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>
	#include <stdint.h>
	#include <arpa/inet.h>
	#include <arpa/nameser.h>
	#include <net/if.h>
	#include <netinet/in.h>
	#include <sys/param.h>
	#include <sys/socket.h>
	#include <sys/time.h>
	#include <sys/types.h>

	#include <not-cancel.h>

	/* Options. Should all be left alone. */
	#define RESOLVSORT
	#define RFC1535
	/* #undef DEBUG */

	static void res_setoptions (res_state, const char , const char )
	internal_function;

	#ifdef RESOLVSORT
	static const char sort_mask_chars[] = "/&";
	#define ISSORTMASK(ch) (strchr(sort_mask_chars, ch) != NULL)
	static u_int32_t net_mask (struct in_addr) __THROW;
	#endif

	#if !defined(isascii) /* XXX - could be a function */
	# define isascii(c) (!(c & 0200))
	#endif

	#ifdef _LIBC
	unsigned long long int __res_initstamp attribute_hidden;
	#endif

	/*
	* Resolver state default settings.
	*/

	/*
	* Set up default settings. If the configuration file exist, the values
	* there will have precedence. Otherwise, the server address is set to
	* INADDR_ANY and the default domain name comes from the gethostname().
	*
	* An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
	* rather than INADDR_ANY ("0.0.0.0") as the default name server address
	* since it was noted that INADDR_ANY actually meant ``the first interface
	* you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
	* it had to be "up" in order for you to reach your own name server. It
	* was later decided that since the recommended practice is to always
	* install local static routes through 127.0.0.1 for all your network
	* interfaces, that we could solve this problem without a code change.
	*
	* The configuration file should always be used, since it is the only way
	* to specify a default domain. If you are running a server on your local
	* machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
	* in the configuration file.
	*
	* Return 0 if completes successfully, -1 on error
	*/
	int
	res_ninit(res_state statp) {
	extern int __res_vinit(res_state, int);

	return (__res_vinit(statp, 0));
	}
	#ifdef _LIBC
	libc_hidden_def (__res_ninit)
	#endif

	/* This function has to be reachable by res_data.c but not publically. */
	int
	__res_vinit(res_state statp, int preinit) {
	FILE *fp;
	char cp, *pp;
	int n;
	char buf[BUFSIZ];
	int nserv = 0; /* number of nameservers read from file */
	int have_serv6 = 0;
	int haveenv = 0;
	int havesearch = 0;
	#ifdef RESOLVSORT
	int nsort = 0;
	char *net;
	#endif
	#ifndef RFC1535
	int dots;
	#endif
	#ifdef _LIBC
	statp->_u._ext.initstamp = __res_initstamp;
	#endif

	if (!preinit) {
	statp->retrans = RES_TIMEOUT;
	statp->retry = RES_DFLRETRY;
	statp->options = RES_DEFAULT;
	statp->id = res_randomid();
	}

	statp->nscount = 0;
	statp->defdname[0] = '\0';
	statp->ndots = 1;
	statp->pfcode = 0;
	statp->_vcsock = -1;
	statp->_flags = 0;
	statp->qhook = NULL;
	statp->rhook = NULL;
	statp->_u._ext.nscount = 0;
	for (n = 0; n < MAXNS; n++)
	statp->_u._ext.nsaddrs[n] = NULL;

	/* Allow user to override the local domain definition */
	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
	(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
	statp->defdname[sizeof(statp->defdname) - 1] = '\0';
	haveenv++;

	/*
	* Set search list to be blank-separated strings
	* from rest of env value. Permits users of LOCALDOMAIN
	* to still have a search list, and anyone to set the
	* one that they want to use as an individual (even more
	* important now that the rfc1535 stuff restricts searches)
	*/
	cp = statp->defdname;
	pp = statp->dnsrch;
	*pp++ = cp;
	for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
	if (cp == '\n') / silly backwards compat */
	break;
	else if (cp == ' ' \|\| cp == '\t') {
	*cp = 0;
	n = 1;
	} else if (n) {
	*pp++ = cp;
	n = 0;
	havesearch = 1;
	}
	}
	/* null terminate last domain if there are excess */
	while (cp != '\0' && cp != ' ' && cp != '\t' && cp != '\n')
	cp++;
	*cp = '\0';
	*pp++ = 0;
	}

	#define MATCH(line, name) \
	(!strncmp(line, name, sizeof(name) - 1) && \
	(line[sizeof(name) - 1] == ' ' \|\| \
	line[sizeof(name) - 1] == '\t'))

	if ((fp = fopen(_PATH_RESCONF, "rce")) != NULL) {
	/* No threads use this stream. */
	__fsetlocking (fp, FSETLOCKING_BYCALLER);
	/* read the config file */
	while (__fgets_unlocked(buf, sizeof(buf), fp) != NULL) {
	/* skip comments */
	if (buf == ';' \|\| buf == '#')
	continue;
	/* read default domain name */
	if (MATCH(buf, "domain")) {
	if (haveenv) /* skip if have from environ */
	continue;
	cp = buf + sizeof("domain") - 1;
	while (cp == ' ' \|\| cp == '\t')
	cp++;
	if ((cp == '\0') \|\| (cp == '\n'))
	continue;
	strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
	statp->defdname[sizeof(statp->defdname) - 1] = '\0';
	if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
	*cp = '\0';
	havesearch = 0;
	continue;
	}
	/* set search list */
	if (MATCH(buf, "search")) {
	if (haveenv) /* skip if have from environ */
	continue;
	cp = buf + sizeof("search") - 1;
	while (cp == ' ' \|\| cp == '\t')
	cp++;
	if ((cp == '\0') \|\| (cp == '\n'))
	continue;
	strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
	statp->defdname[sizeof(statp->defdname) - 1] = '\0';
	if ((cp = strchr(statp->defdname, '\n')) != NULL)
	*cp = '\0';
	/*
	* Set search list to be blank-separated strings
	* on rest of line.
	*/
	cp = statp->defdname;
	pp = statp->dnsrch;
	*pp++ = cp;
	for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
	if (cp == ' ' \|\| cp == '\t') {
	*cp = 0;
	n = 1;
	} else if (n) {
	*pp++ = cp;
	n = 0;
	}
	}
	/* null terminate last domain if there are excess */
	while (cp != '\0' && cp != ' ' && *cp != '\t')
	cp++;
	*cp = '\0';
	*pp++ = 0;
	havesearch = 1;
	continue;
	}
	/* read nameservers to query */
	if (MATCH(buf, "nameserver") && nserv < MAXNS) {
	struct in_addr a;

	cp = buf + sizeof("nameserver") - 1;
	while (cp == ' ' \|\| cp == '\t')
	cp++;
	if ((cp != '\0') && (cp != '\n')
	&& __inet_aton(cp, &a)) {
	statp->nsaddr_list[nserv].sin_addr = a;
	statp->nsaddr_list[nserv].sin_family = AF_INET;
	statp->nsaddr_list[nserv].sin_port =
	htons(NAMESERVER_PORT);
	nserv++;
	#ifdef _LIBC
	} else {
	struct in6_addr a6;
	char *el;

	if ((el = strpbrk(cp, " \t\n")) != NULL)
	*el = '\0';
	if ((el = strchr(cp, SCOPE_DELIMITER)) != NULL)
	*el = '\0';
	if ((*cp != '\0') &&
	(__inet_pton(AF_INET6, cp, &a6) > 0)) {
	struct sockaddr_in6 *sa6;

	sa6 = malloc(sizeof(*sa6));
	if (sa6 != NULL) {
	sa6->sin6_family = AF_INET6;
	sa6->sin6_port = htons(NAMESERVER_PORT);
	sa6->sin6_flowinfo = 0;
	sa6->sin6_addr = a6;

	if (__glibc_likely (el == NULL))
	sa6->sin6_scope_id = 0;
	else {
	int try_numericscope = 1;
	if (IN6_IS_ADDR_LINKLOCAL (&a6)
	\|\| IN6_IS_ADDR_MC_LINKLOCAL (&a6)) {
	sa6->sin6_scope_id
	= __if_nametoindex (el + 1);
	if (sa6->sin6_scope_id != 0)
	try_numericscope = 0;
	}

	if (try_numericscope) {
	char *end;
	sa6->sin6_scope_id
	= (uint32_t) strtoul (el + 1, &end,
	10);
	if (*end != '\0')
	sa6->sin6_scope_id = 0;
	}
	}

	statp->nsaddr_list[nserv].sin_family = 0;
	statp->_u._ext.nsaddrs[nserv] = sa6;
	statp->_u._ext.nssocks[nserv] = -1;
	have_serv6 = 1;
	nserv++;
	}
	}
	#endif
	}
	continue;
	}
	#ifdef RESOLVSORT
	if (MATCH(buf, "sortlist")) {
	struct in_addr a;

	cp = buf + sizeof("sortlist") - 1;
	while (nsort < MAXRESOLVSORT) {
	while (cp == ' ' \|\| cp == '\t')
	cp++;
	if (cp == '\0' \|\| cp == '\n' \|\| *cp == ';')
	break;
	net = cp;
	while (cp && !ISSORTMASK(cp) && *cp != ';' &&
	isascii(cp) && !isspace(cp))
	cp++;
	n = *cp;
	*cp = 0;
	if (__inet_aton(net, &a)) {
	statp->sort_list[nsort].addr = a;
	if (ISSORTMASK(n)) {
	*cp++ = n;
	net = cp;
	while (cp && cp != ';' &&
	isascii(cp) && !isspace(cp))
	cp++;
	n = *cp;
	*cp = 0;
	if (__inet_aton(net, &a)) {
	statp->sort_list[nsort].mask = a.s_addr;
	} else {
	statp->sort_list[nsort].mask =
	net_mask(statp->sort_list[nsort].addr);
	}
	} else {
	statp->sort_list[nsort].mask =
	net_mask(statp->sort_list[nsort].addr);
	}
	nsort++;
	}
	*cp = n;
	}
	continue;
	}
	#endif
	if (MATCH(buf, "options")) {
	res_setoptions(statp, buf + sizeof("options") - 1, "conf");
	continue;
	}
	}
	statp->nscount = nserv;
	#ifdef _LIBC
	if (have_serv6) {
	/* We try IPv6 servers again. */
	statp->ipv6_unavail = false;
	}
	#endif
	#ifdef RESOLVSORT
	statp->nsort = nsort;
	#endif
	(void) fclose(fp);
	}
	if (__builtin_expect(statp->nscount == 0, 0)) {
	statp->nsaddr.sin_addr = __inet_makeaddr(IN_LOOPBACKNET, 1);
	statp->nsaddr.sin_family = AF_INET;
	statp->nsaddr.sin_port = htons(NAMESERVER_PORT);
	statp->nscount = 1;
	}
	if (statp->defdname[0] == 0 &&
	__gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
	(cp = strchr(buf, '.')) != NULL)
	strcpy(statp->defdname, cp + 1);

	/* find components of local domain that might be searched */
	if (havesearch == 0) {
	pp = statp->dnsrch;
	*pp++ = statp->defdname;
	*pp = NULL;

	#ifndef RFC1535
	dots = 0;
	for (cp = statp->defdname; *cp; cp++)
	dots += (*cp == '.');

	cp = statp->defdname;
	while (pp < statp->dnsrch + MAXDFLSRCH) {
	if (dots < LOCALDOMAINPARTS)
	break;
	cp = __rawmemchr(cp, '.') + 1; /* we know there is one */
	*pp++ = cp;
	dots--;
	}
	*pp = NULL;
	#ifdef DEBUG
	if (statp->options & RES_DEBUG) {
	printf(";; res_init()... default dnsrch list:\n");
	for (pp = statp->dnsrch; *pp; pp++)
	printf(";;\t%s\n", *pp);
	printf(";;\t..END..\n");
	}
	#endif
	#endif /* !RFC1535 */
	}

	if ((cp = getenv("RES_OPTIONS")) != NULL)
	res_setoptions(statp, cp, "env");
	statp->options \|= RES_INIT;
	return (0);
	}

	static void
	internal_function
	res_setoptions(res_state statp, const char options, const char source) {
	const char *cp = options;
	int i;

	#ifdef DEBUG
	if (statp->options & RES_DEBUG)
	printf(";; res_setoptions(\"%s\", \"%s\")...\n",
	options, source);
	#endif
	while (*cp) {
	/* skip leading and inner runs of spaces */
	while (cp == ' ' \|\| cp == '\t')
	cp++;
	/* search for and process individual options */
	if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
	i = atoi(cp + sizeof("ndots:") - 1);
	if (i <= RES_MAXNDOTS)
	statp->ndots = i;
	else
	statp->ndots = RES_MAXNDOTS;
	#ifdef DEBUG
	if (statp->options & RES_DEBUG)
	printf(";;\tndots=%d\n", statp->ndots);
	#endif
	} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
	i = atoi(cp + sizeof("timeout:") - 1);
	if (i <= RES_MAXRETRANS)
	statp->retrans = i;
	else
	statp->retrans = RES_MAXRETRANS;
	} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
	i = atoi(cp + sizeof("attempts:") - 1);
	if (i <= RES_MAXRETRY)
	statp->retry = i;
	else
	statp->retry = RES_MAXRETRY;
	} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
	#ifdef DEBUG
	if (!(statp->options & RES_DEBUG)) {
	printf(";; res_setoptions(\"%s\", \"%s\")..\n",
	options, source);
	statp->options \|= RES_DEBUG;
	}
	printf(";;\tdebug\n");
	#endif
	} else {
	static const struct
	{
	char str[22];
	uint8_t len;
	uint8_t clear;
	unsigned long int flag;
	} options[] = {
	#define STRnLEN(str) str, sizeof (str) - 1
	{ STRnLEN ("inet6"), 0, RES_USE_INET6 },
	{ STRnLEN ("ip6-bytestring"), 0, RES_USEBSTRING },
	{ STRnLEN ("no-ip6-dotint"), 0, RES_NOIP6DOTINT },
	{ STRnLEN ("ip6-dotint"), 1, ~RES_NOIP6DOTINT },
	{ STRnLEN ("rotate"), 0, RES_ROTATE },
	{ STRnLEN ("no-check-names"), 0, RES_NOCHECKNAME },
	{ STRnLEN ("edns0"), 0, RES_USE_EDNS0 },
	{ STRnLEN ("single-request-reopen"), 0, RES_SNGLKUPREOP },
	{ STRnLEN ("single-request"), 0, RES_SNGLKUP },
	{ STRnLEN ("no_tld_query"), 0, RES_NOTLDQUERY },
	{ STRnLEN ("no-tld-query"), 0, RES_NOTLDQUERY },
	{ STRnLEN ("use-vc"), 0, RES_USEVC }
	};
	#define noptions (sizeof (options) / sizeof (options[0]))
	int i;
	for (i = 0; i < noptions; ++i)
	if (strncmp (cp, options[i].str, options[i].len) == 0)
	{
	if (options[i].clear)
	statp->options &= options[i].flag;
	else
	statp->options \|= options[i].flag;
	break;
	}
	if (i == noptions) {
	/* XXX - print a warning here? */
	}
	}
	/* skip to next run of spaces */
	while (cp && cp != ' ' && *cp != '\t')
	cp++;
	}
	}

	#ifdef RESOLVSORT
	/* XXX - should really support CIDR which means explicit masks always. */
	/* XXX - should really use system's version of this */
	static u_int32_t
	net_mask (struct in_addr in)
	{
	u_int32_t i = ntohl(in.s_addr);

	if (IN_CLASSA(i))
	return (htonl(IN_CLASSA_NET));
	else if (IN_CLASSB(i))
	return (htonl(IN_CLASSB_NET));
	return (htonl(IN_CLASSC_NET));
	}
	#endif

	u_int
	res_randomid(void) {
	return 0xffff & __getpid();
	}
	#ifdef _LIBC
	libc_hidden_def (__res_randomid)
	#endif


	/*
	* This routine is for closing the socket if a virtual circuit is used and
	* the program wants to close it. This provides support for endhostent()
	* which expects to close the socket.
	*
	* This routine is not expected to be user visible.
	*/
	void
	__res_iclose(res_state statp, bool free_addr) {
	int ns;

	if (statp->_vcsock >= 0) {
	close_not_cancel_no_status(statp->_vcsock);
	statp->_vcsock = -1;
	statp->_flags &= ~(RES_F_VC \| RES_F_CONN);
	}
	for (ns = 0; ns < statp->_u._ext.nscount; ns++)
	if (statp->_u._ext.nsaddrs[ns]) {
	if (statp->_u._ext.nssocks[ns] != -1) {
	close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
	statp->_u._ext.nssocks[ns] = -1;
	}
	if (free_addr) {
	free (statp->_u._ext.nsaddrs[ns]);
	statp->_u._ext.nsaddrs[ns] = NULL;
	}
	}
	}
	libc_hidden_def (__res_iclose)

	void
	res_nclose(res_state statp)
	{
	__res_iclose (statp, true);
	}
	#ifdef _LIBC
	libc_hidden_def (__res_nclose)
	#endif

	#ifdef _LIBC
	# ifdef _LIBC_REENTRANT
	/* This is called when a thread is exiting to free resources held in _res. */
	static void __attribute__ ((section ("__libc_thread_freeres_fn")))
	res_thread_freeres (void)
	{
	if (_res.nscount == 0)
	/* Never called res_ninit. */
	return;

	__res_iclose (&_res, true); /* Close any VC sockets. */

	/* Make sure we do a full re-initialization the next time. */
	_res.options = 0;
	}
	text_set_element (__libc_thread_subfreeres, res_thread_freeres);
	text_set_element (__libc_subfreeres, res_thread_freeres);
	# endif
	#endif