f991bb5181
routines from contrib/bind directly. There were too many problems, including having to add -DUSE_OPTIONS_H to the entire libc source in order for the contrib code to pick up it's options, and so on. Instead, I've merged the changes, libc is now self contained again.
455 lines
14 KiB
C
455 lines
14 KiB
C
/*
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* ++Copyright++ 1985, 1989, 1993
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* -
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* Copyright (c) 1985, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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* -
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* Portions Copyright (c) 1993 by Digital Equipment Corporation.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies, and that
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* the name of Digital Equipment Corporation not be used in advertising or
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* publicity pertaining to distribution of the document or software without
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* specific, written prior permission.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
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* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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* -
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* --Copyright--
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
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static char rcsid[] = "$Id: res_init.c,v 8.5 1996/08/05 08:31:35 vixie Exp $";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include "res_config.h"
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#include <arpa/nameser.h>
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#include <stdio.h>
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#include <ctype.h>
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#include <resolv.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <string.h>
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static void res_setoptions __P((char *, char *));
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#ifdef RESOLVSORT
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static const char sort_mask[] = "/&";
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#define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
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static u_int32_t net_mask __P((struct in_addr));
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#endif
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/*
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* Resolver state default settings.
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*/
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struct __res_state _res;
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/*
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* Set up default settings. If the configuration file exist, the values
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* there will have precedence. Otherwise, the server address is set to
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* INADDR_ANY and the default domain name comes from the gethostname().
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*
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* An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
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* rather than INADDR_ANY ("0.0.0.0") as the default name server address
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* since it was noted that INADDR_ANY actually meant ``the first interface
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* you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
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* it had to be "up" in order for you to reach your own name server. It
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* was later decided that since the recommended practice is to always
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* install local static routes through 127.0.0.1 for all your network
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* interfaces, that we could solve this problem without a code change.
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*
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* The configuration file should always be used, since it is the only way
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* to specify a default domain. If you are running a server on your local
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* machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
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* in the configuration file.
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*
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* Return 0 if completes successfully, -1 on error
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*/
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int
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res_init()
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{
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register FILE *fp;
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register char *cp, **pp;
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register int n;
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char buf[BUFSIZ];
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int nserv = 0; /* number of nameserver records read from file */
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int haveenv = 0;
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int havesearch = 0;
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#ifdef RESOLVSORT
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int nsort = 0;
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char *net;
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#endif
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#ifndef RFC1535
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int dots;
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#endif
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/*
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* These three fields used to be statically initialized. This made
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* it hard to use this code in a shared library. It is necessary,
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* now that we're doing dynamic initialization here, that we preserve
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* the old semantics: if an application modifies one of these three
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* fields of _res before res_init() is called, res_init() will not
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* alter them. Of course, if an application is setting them to
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* _zero_ before calling res_init(), hoping to override what used
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* to be the static default, we can't detect it and unexpected results
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* will follow. Zero for any of these fields would make no sense,
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* so one can safely assume that the applications were already getting
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* unexpected results.
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*
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* _res.options is tricky since some apps were known to diddle the bits
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* before res_init() was first called. We can't replicate that semantic
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* with dynamic initialization (they may have turned bits off that are
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* set in RES_DEFAULT). Our solution is to declare such applications
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* "broken". They could fool us by setting RES_INIT but none do (yet).
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*/
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if (!_res.retrans)
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_res.retrans = RES_TIMEOUT;
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if (!_res.retry)
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_res.retry = 4;
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if (!(_res.options & RES_INIT))
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_res.options = RES_DEFAULT;
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/*
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* This one used to initialize implicitly to zero, so unless the app
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* has set it to something in particular, we can randomize it now.
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*/
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if (!_res.id)
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_res.id = res_randomid();
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#ifdef USELOOPBACK
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_res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
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#else
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_res.nsaddr.sin_addr.s_addr = INADDR_ANY;
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#endif
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_res.nsaddr.sin_family = AF_INET;
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_res.nsaddr.sin_port = htons(NAMESERVER_PORT);
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_res.nscount = 1;
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_res.ndots = 1;
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_res.pfcode = 0;
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/* Allow user to override the local domain definition */
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if ((cp = getenv("LOCALDOMAIN")) != NULL) {
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(void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
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haveenv++;
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/*
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* Set search list to be blank-separated strings
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* from rest of env value. Permits users of LOCALDOMAIN
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* to still have a search list, and anyone to set the
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* one that they want to use as an individual (even more
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* important now that the rfc1535 stuff restricts searches)
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*/
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cp = _res.defdname;
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pp = _res.dnsrch;
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*pp++ = cp;
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for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
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if (*cp == '\n') /* silly backwards compat */
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break;
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else if (*cp == ' ' || *cp == '\t') {
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*cp = 0;
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n = 1;
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} else if (n) {
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*pp++ = cp;
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n = 0;
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havesearch = 1;
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}
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}
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/* null terminate last domain if there are excess */
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while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
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cp++;
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*cp = '\0';
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*pp++ = 0;
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}
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#define MATCH(line, name) \
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(!strncmp(line, name, sizeof(name) - 1) && \
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(line[sizeof(name) - 1] == ' ' || \
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line[sizeof(name) - 1] == '\t'))
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if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
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/* read the config file */
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while (fgets(buf, sizeof(buf), fp) != NULL) {
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/* skip comments */
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if (*buf == ';' || *buf == '#')
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continue;
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/* read default domain name */
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if (MATCH(buf, "domain")) {
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if (haveenv) /* skip if have from environ */
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continue;
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cp = buf + sizeof("domain") - 1;
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while (*cp == ' ' || *cp == '\t')
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cp++;
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if ((*cp == '\0') || (*cp == '\n'))
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continue;
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strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
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if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
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*cp = '\0';
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havesearch = 0;
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continue;
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}
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/* set search list */
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if (MATCH(buf, "search")) {
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if (haveenv) /* skip if have from environ */
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continue;
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cp = buf + sizeof("search") - 1;
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while (*cp == ' ' || *cp == '\t')
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cp++;
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if ((*cp == '\0') || (*cp == '\n'))
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continue;
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strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
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if ((cp = strchr(_res.defdname, '\n')) != NULL)
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*cp = '\0';
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/*
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* Set search list to be blank-separated strings
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* on rest of line.
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*/
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cp = _res.defdname;
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pp = _res.dnsrch;
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*pp++ = cp;
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for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
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if (*cp == ' ' || *cp == '\t') {
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*cp = 0;
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n = 1;
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} else if (n) {
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*pp++ = cp;
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n = 0;
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}
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}
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/* null terminate last domain if there are excess */
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while (*cp != '\0' && *cp != ' ' && *cp != '\t')
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cp++;
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*cp = '\0';
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*pp++ = 0;
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havesearch = 1;
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continue;
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}
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/* read nameservers to query */
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if (MATCH(buf, "nameserver") && nserv < MAXNS) {
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struct in_addr a;
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cp = buf + sizeof("nameserver") - 1;
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while (*cp == ' ' || *cp == '\t')
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cp++;
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if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
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_res.nsaddr_list[nserv].sin_addr = a;
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_res.nsaddr_list[nserv].sin_family = AF_INET;
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_res.nsaddr_list[nserv].sin_port =
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htons(NAMESERVER_PORT);
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nserv++;
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}
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continue;
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}
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#ifdef RESOLVSORT
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if (MATCH(buf, "sortlist")) {
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struct in_addr a;
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cp = buf + sizeof("sortlist") - 1;
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while (nsort < MAXRESOLVSORT) {
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while (*cp == ' ' || *cp == '\t')
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cp++;
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if (*cp == '\0' || *cp == '\n' || *cp == ';')
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break;
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net = cp;
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while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
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isascii(*cp) && !isspace(*cp))
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cp++;
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n = *cp;
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*cp = 0;
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if (inet_aton(net, &a)) {
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_res.sort_list[nsort].addr = a;
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if (ISSORTMASK(n)) {
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*cp++ = n;
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net = cp;
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while (*cp && *cp != ';' &&
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isascii(*cp) && !isspace(*cp))
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cp++;
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n = *cp;
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*cp = 0;
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if (inet_aton(net, &a)) {
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_res.sort_list[nsort].mask = a.s_addr;
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} else {
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_res.sort_list[nsort].mask =
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net_mask(_res.sort_list[nsort].addr);
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}
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} else {
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_res.sort_list[nsort].mask =
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net_mask(_res.sort_list[nsort].addr);
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}
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nsort++;
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}
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*cp = n;
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}
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continue;
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}
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#endif
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if (MATCH(buf, "options")) {
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res_setoptions(buf + sizeof("options") - 1, "conf");
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continue;
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}
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}
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if (nserv > 1)
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_res.nscount = nserv;
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#ifdef RESOLVSORT
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_res.nsort = nsort;
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#endif
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(void) fclose(fp);
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}
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if (_res.defdname[0] == 0 &&
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gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
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(cp = strchr(buf, '.')) != NULL)
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strcpy(_res.defdname, cp + 1);
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/* find components of local domain that might be searched */
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if (havesearch == 0) {
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pp = _res.dnsrch;
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*pp++ = _res.defdname;
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*pp = NULL;
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#ifndef RFC1535
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dots = 0;
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for (cp = _res.defdname; *cp; cp++)
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dots += (*cp == '.');
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cp = _res.defdname;
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while (pp < _res.dnsrch + MAXDFLSRCH) {
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if (dots < LOCALDOMAINPARTS)
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break;
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cp = strchr(cp, '.') + 1; /* we know there is one */
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*pp++ = cp;
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dots--;
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}
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*pp = NULL;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG) {
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printf(";; res_init()... default dnsrch list:\n");
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for (pp = _res.dnsrch; *pp; pp++)
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printf(";;\t%s\n", *pp);
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printf(";;\t..END..\n");
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}
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#endif /* DEBUG */
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#endif /* !RFC1535 */
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}
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if ((cp = getenv("RES_OPTIONS")) != NULL)
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res_setoptions(cp, "env");
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_res.options |= RES_INIT;
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return (0);
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}
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static void
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res_setoptions(options, source)
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char *options, *source;
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{
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char *cp = options;
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int i;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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printf(";; res_setoptions(\"%s\", \"%s\")...\n",
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options, source);
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#endif
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while (*cp) {
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/* skip leading and inner runs of spaces */
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while (*cp == ' ' || *cp == '\t')
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cp++;
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/* search for and process individual options */
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if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
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i = atoi(cp + sizeof("ndots:") - 1);
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if (i <= RES_MAXNDOTS)
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_res.ndots = i;
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else
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_res.ndots = RES_MAXNDOTS;
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#ifdef DEBUG
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if (_res.options & RES_DEBUG)
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printf(";;\tndots=%d\n", _res.ndots);
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#endif
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} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
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#ifdef DEBUG
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if (!(_res.options & RES_DEBUG)) {
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printf(";; res_setoptions(\"%s\", \"%s\")..\n",
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options, source);
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_res.options |= RES_DEBUG;
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}
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printf(";;\tdebug\n");
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#endif
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} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
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_res.options |= RES_USE_INET6;
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} else {
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/* XXX - print a warning here? */
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}
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/* skip to next run of spaces */
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while (*cp && *cp != ' ' && *cp != '\t')
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cp++;
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}
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}
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#ifdef RESOLVSORT
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/* XXX - should really support CIDR which means explicit masks always. */
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static u_int32_t
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net_mask(in) /* XXX - should really use system's version of this */
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struct in_addr in;
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{
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register u_int32_t i = ntohl(in.s_addr);
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if (IN_CLASSA(i))
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return (htonl(IN_CLASSA_NET));
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else if (IN_CLASSB(i))
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return (htonl(IN_CLASSB_NET));
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return (htonl(IN_CLASSC_NET));
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}
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#endif
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u_int16_t
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res_randomid()
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{
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struct timeval now;
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gettimeofday(&now, NULL);
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return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
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}
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