2 * Copyright (c) 1985, 1989, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
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13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
37 * Permission to use, copy, modify, and distribute this software for any
38 * purpose with or without fee is hereby granted, provided that the above
39 * copyright notice and this permission notice appear in all copies, and that
40 * the name of Digital Equipment Corporation not be used in advertising or
41 * publicity pertaining to distribution of the document or software without
42 * specific, written prior permission.
44 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
45 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
46 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
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48 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
49 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
50 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
55 * Portions Copyright (c) 1996 by Internet Software Consortium.
57 * Permission to use, copy, modify, and distribute this software for any
58 * purpose with or without fee is hereby granted, provided that the above
59 * copyright notice and this permission notice appear in all copies.
61 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
62 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
63 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
64 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
65 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
66 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
67 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
71 #if defined(LIBC_SCCS) && !defined(lint)
72 static char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
73 static char orig_rcsid[] = "From: Id: res_init.c,v 8.7 1996/11/18 09:10:04 vixie Exp $";
74 static char rcsid[] = "$FreeBSD$";
75 #endif /* LIBC_SCCS and not lint */
77 #include <sys/types.h>
78 #include <sys/param.h>
79 #include <sys/socket.h>
81 #include <netinet/in.h>
82 #include <arpa/inet.h>
83 #include <arpa/nameser.h>
91 #include "res_config.h"
93 static void res_setoptions __P((char *, char *));
96 static const char sort_mask[] = "/&";
97 #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
98 static u_int32_t net_mask __P((struct in_addr));
101 #if !defined(isascii) /* XXX - could be a function */
102 # define isascii(c) (!(c & 0200))
106 * Resolver state default settings.
109 struct __res_state _res
110 # if defined(__BIND_RES_TEXT)
111 = { RES_TIMEOUT, } /* Motorola, et al. */
117 * Set up default settings. If the configuration file exist, the values
118 * there will have precedence. Otherwise, the server address is set to
119 * INADDR_ANY and the default domain name comes from the gethostname().
121 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
122 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
123 * since it was noted that INADDR_ANY actually meant ``the first interface
124 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
125 * it had to be "up" in order for you to reach your own name server. It
126 * was later decided that since the recommended practice is to always
127 * install local static routes through 127.0.0.1 for all your network
128 * interfaces, that we could solve this problem without a code change.
130 * The configuration file should always be used, since it is the only way
131 * to specify a default domain. If you are running a server on your local
132 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
133 * in the configuration file.
135 * Return 0 if completes successfully, -1 on error
141 register char *cp, **pp;
144 int nserv = 0; /* number of nameserver records read from file */
156 * These three fields used to be statically initialized. This made
157 * it hard to use this code in a shared library. It is necessary,
158 * now that we're doing dynamic initialization here, that we preserve
159 * the old semantics: if an application modifies one of these three
160 * fields of _res before res_init() is called, res_init() will not
161 * alter them. Of course, if an application is setting them to
162 * _zero_ before calling res_init(), hoping to override what used
163 * to be the static default, we can't detect it and unexpected results
164 * will follow. Zero for any of these fields would make no sense,
165 * so one can safely assume that the applications were already getting
166 * unexpected results.
168 * _res.options is tricky since some apps were known to diddle the bits
169 * before res_init() was first called. We can't replicate that semantic
170 * with dynamic initialization (they may have turned bits off that are
171 * set in RES_DEFAULT). Our solution is to declare such applications
172 * "broken". They could fool us by setting RES_INIT but none do (yet).
175 _res.retrans = RES_TIMEOUT;
178 if (!(_res.options & RES_INIT))
179 _res.options = RES_DEFAULT;
182 * This one used to initialize implicitly to zero, so unless the app
183 * has set it to something in particular, we can randomize it now.
186 _res.id = res_randomid();
189 _res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
191 _res.nsaddr.sin_addr.s_addr = INADDR_ANY;
193 _res.nsaddr.sin_family = AF_INET;
194 _res.nsaddr.sin_port = htons(NAMESERVER_PORT);
199 /* Allow user to override the local domain definition */
200 if (issetugid() == 0 && (cp = getenv("LOCALDOMAIN")) != NULL) {
201 (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
202 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
206 * Set search list to be blank-separated strings
207 * from rest of env value. Permits users of LOCALDOMAIN
208 * to still have a search list, and anyone to set the
209 * one that they want to use as an individual (even more
210 * important now that the rfc1535 stuff restricts searches)
215 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
216 if (*cp == '\n') /* silly backwards compat */
218 else if (*cp == ' ' || *cp == '\t') {
227 /* null terminate last domain if there are excess */
228 while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
234 #define MATCH(line, name) \
235 (!strncmp(line, name, sizeof(name) - 1) && \
236 (line[sizeof(name) - 1] == ' ' || \
237 line[sizeof(name) - 1] == '\t'))
239 if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
240 /* read the config file */
241 while (fgets(buf, sizeof(buf), fp) != NULL) {
243 if (*buf == ';' || *buf == '#')
245 /* read default domain name */
246 if (MATCH(buf, "domain")) {
247 if (haveenv) /* skip if have from environ */
249 cp = buf + sizeof("domain") - 1;
250 while (*cp == ' ' || *cp == '\t')
252 if ((*cp == '\0') || (*cp == '\n'))
254 strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
255 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
256 if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
261 /* set search list */
262 if (MATCH(buf, "search")) {
263 if (haveenv) /* skip if have from environ */
265 cp = buf + sizeof("search") - 1;
266 while (*cp == ' ' || *cp == '\t')
268 if ((*cp == '\0') || (*cp == '\n'))
270 strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
271 _res.defdname[sizeof(_res.defdname) - 1] = '\0';
272 if ((cp = strchr(_res.defdname, '\n')) != NULL)
275 * Set search list to be blank-separated strings
281 for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
282 if (*cp == ' ' || *cp == '\t') {
290 /* null terminate last domain if there are excess */
291 while (*cp != '\0' && *cp != ' ' && *cp != '\t')
298 /* read nameservers to query */
299 if (MATCH(buf, "nameserver") && nserv < MAXNS) {
302 cp = buf + sizeof("nameserver") - 1;
303 while (*cp == ' ' || *cp == '\t')
305 if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
306 _res.nsaddr_list[nserv].sin_addr = a;
307 _res.nsaddr_list[nserv].sin_family = AF_INET;
308 _res.nsaddr_list[nserv].sin_port =
309 htons(NAMESERVER_PORT);
315 if (MATCH(buf, "sortlist")) {
318 cp = buf + sizeof("sortlist") - 1;
319 while (nsort < MAXRESOLVSORT) {
320 while (*cp == ' ' || *cp == '\t')
322 if (*cp == '\0' || *cp == '\n' || *cp == ';')
325 while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
326 isascii(*cp) && !isspace(*cp))
330 if (inet_aton(net, &a)) {
331 _res.sort_list[nsort].addr = a;
335 while (*cp && *cp != ';' &&
336 isascii(*cp) && !isspace(*cp))
340 if (inet_aton(net, &a)) {
341 _res.sort_list[nsort].mask = a.s_addr;
343 _res.sort_list[nsort].mask =
344 net_mask(_res.sort_list[nsort].addr);
347 _res.sort_list[nsort].mask =
348 net_mask(_res.sort_list[nsort].addr);
357 if (MATCH(buf, "options")) {
358 res_setoptions(buf + sizeof("options") - 1, "conf");
363 _res.nscount = nserv;
369 if (_res.defdname[0] == 0 &&
370 gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
371 (cp = strchr(buf, '.')) != NULL)
372 strcpy(_res.defdname, cp + 1);
374 /* find components of local domain that might be searched */
375 if (havesearch == 0) {
377 *pp++ = _res.defdname;
382 for (cp = _res.defdname; *cp; cp++)
383 dots += (*cp == '.');
386 while (pp < _res.dnsrch + MAXDFLSRCH) {
387 if (dots < LOCALDOMAINPARTS)
389 cp = strchr(cp, '.') + 1; /* we know there is one */
395 if (_res.options & RES_DEBUG) {
396 printf(";; res_init()... default dnsrch list:\n");
397 for (pp = _res.dnsrch; *pp; pp++)
398 printf(";;\t%s\n", *pp);
399 printf(";;\t..END..\n");
402 #endif /* !RFC1535 */
406 _res.options |= RES_NOALIASES;
407 else if ((cp = getenv("RES_OPTIONS")) != NULL)
408 res_setoptions(cp, "env");
409 _res.options |= RES_INIT;
414 res_setoptions(options, source)
415 char *options, *source;
421 if (_res.options & RES_DEBUG)
422 printf(";; res_setoptions(\"%s\", \"%s\")...\n",
426 /* skip leading and inner runs of spaces */
427 while (*cp == ' ' || *cp == '\t')
429 /* search for and process individual options */
430 if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
431 i = atoi(cp + sizeof("ndots:") - 1);
432 if (i <= RES_MAXNDOTS)
435 _res.ndots = RES_MAXNDOTS;
437 if (_res.options & RES_DEBUG)
438 printf(";;\tndots=%d\n", _res.ndots);
440 } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
442 if (!(_res.options & RES_DEBUG)) {
443 printf(";; res_setoptions(\"%s\", \"%s\")..\n",
445 _res.options |= RES_DEBUG;
447 printf(";;\tdebug\n");
449 } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
450 _res.options |= RES_USE_INET6;
451 } else if (!strncmp(cp, "no_tld_query", sizeof("no_tld_query") - 1)) {
452 _res.options |= RES_NOTLDQUERY;
454 /* XXX - print a warning here? */
456 /* skip to next run of spaces */
457 while (*cp && *cp != ' ' && *cp != '\t')
463 /* XXX - should really support CIDR which means explicit masks always. */
465 net_mask(in) /* XXX - should really use system's version of this */
468 register u_int32_t i = ntohl(in.s_addr);
471 return (htonl(IN_CLASSA_NET));
472 else if (IN_CLASSB(i))
473 return (htonl(IN_CLASSB_NET));
474 return (htonl(IN_CLASSC_NET));
483 gettimeofday(&now, NULL);
484 return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
488 * Weak aliases for applications that use certain private entry points,
489 * and fail to include <resolv.h>.
492 __weak_reference(__res_init, res_init);