xref: /illumos-gate/usr/src/lib/libresolv2/common/resolv/res_init.c (revision f5961f52af4b214e15b671fc88e5f5ea948e9dee)
1  /*
2   * Copyright (c) 1996, 2010, Oracle and/or its affiliates. All rights reserved.
3   */
4  
5  
6  /*
7   * Copyright (c) 1985, 1989, 1993
8   *    The Regents of the University of California.  All rights reserved.
9   *
10   * Redistribution and use in source and binary forms, with or without
11   * modification, are permitted provided that the following conditions
12   * are met:
13   * 1. Redistributions of source code must retain the above copyright
14   *    notice, this list of conditions and the following disclaimer.
15   * 2. Redistributions in binary form must reproduce the above copyright
16   *    notice, this list of conditions and the following disclaimer in the
17   *    documentation and/or other materials provided with the distribution.
18   * 3. All advertising materials mentioning features or use of this software
19   *    must display the following acknowledgement:
20   * 	This product includes software developed by the University of
21   * 	California, Berkeley and its contributors.
22   * 4. Neither the name of the University nor the names of its contributors
23   *    may be used to endorse or promote products derived from this software
24   *    without specific prior written permission.
25   *
26   * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29   * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36   * SUCH DAMAGE.
37   */
38  
39  /*
40   * Portions Copyright (c) 1993 by Digital Equipment Corporation.
41   *
42   * Permission to use, copy, modify, and distribute this software for any
43   * purpose with or without fee is hereby granted, provided that the above
44   * copyright notice and this permission notice appear in all copies, and that
45   * the name of Digital Equipment Corporation not be used in advertising or
46   * publicity pertaining to distribution of the document or software without
47   * specific, written prior permission.
48   *
49   * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
50   * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
51   * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
52   * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
53   * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
54   * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
55   * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
56   * SOFTWARE.
57   */
58  
59  /*
60   * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
61   * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
62   *
63   * Permission to use, copy, modify, and distribute this software for any
64   * purpose with or without fee is hereby granted, provided that the above
65   * copyright notice and this permission notice appear in all copies.
66   *
67   * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
68   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
69   * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
70   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
71   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
72   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
73   * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
74   */
75  
76  #if defined(LIBC_SCCS) && !defined(lint)
77  static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
78  static const char rcsid[] = "$Id: res_init.c,v 1.26 2008/12/11 09:59:00 marka Exp $";
79  #endif /* LIBC_SCCS and not lint */
80  
81  #include "port_before.h"
82  
83  #include <sys/types.h>
84  #include <sys/param.h>
85  #include <sys/socket.h>
86  #include <sys/time.h>
87  
88  #include <netinet/in.h>
89  #include <arpa/inet.h>
90  #include <arpa/nameser.h>
91  
92  #include <ctype.h>
93  #include <stdio.h>
94  #include <stdlib.h>
95  #include <string.h>
96  #include <unistd.h>
97  #include <netdb.h>
98  
99  #ifndef HAVE_MD5
100  # include "../dst/md5.h"
101  #else
102  # ifdef SOLARIS2
103  #  include <sys/md5.h>
104  # endif
105  #endif
106  #ifndef _MD5_H_
107  # define _MD5_H_ 1	/*%< make sure we do not include rsaref md5.h file */
108  #endif
109  
110  
111  #include "port_after.h"
112  
113  /* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
114  #include <resolv.h>
115  
116  /* ISC purposely put port_after.h before <resolv.h> to force in6 stuff
117   * (above) so we explicitly include port_resolv.h here */
118  #include "port_resolv.h"
119  
120  #include "res_private.h"
121  
122  /*% Options.  Should all be left alone. */
123  #define RESOLVSORT
124  #define DEBUG
125  
126  #ifdef  SUNW_INITCHKIF
127  #include <net/if.h>
128  #include <netinet/if_ether.h>
129  #include <sys/sockio.h>
130  #define MAXIFS  8192
131  #endif  /* SUNW_INITCHKIF */
132  
133  #ifdef SOLARIS2
134  #include <sys/systeminfo.h>
135  #endif
136  
137  static void res_setoptions __P((res_state, const char *, const char *));
138  
139  #ifdef RESOLVSORT
140  static const char sort_mask[] = "/&";
141  #define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
142  static u_int32_t net_mask __P((struct in_addr));
143  #endif
144  
145  #if !defined(isascii)	/*%< XXX - could be a function */
146  # define isascii(c) (!(c & 0200))
147  #endif
148  
149  /*
150   * Resolver state default settings.
151   */
152  
153  /*%
154   * Set up default settings.  If the configuration file exist, the values
155   * there will have precedence.  Otherwise, the server address is set to
156   * INADDR_ANY and the default domain name comes from the gethostname().
157   *
158   * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
159   * rather than INADDR_ANY ("0.0.0.0") as the default name server address
160   * since it was noted that INADDR_ANY actually meant ``the first interface
161   * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
162   * it had to be "up" in order for you to reach your own name server.  It
163   * was later decided that since the recommended practice is to always
164   * install local static routes through 127.0.0.1 for all your network
165   * interfaces, that we could solve this problem without a code change.
166   *
167   * The configuration file should always be used, since it is the only way
168   * to specify a default domain.  If you are running a server on your local
169   * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
170   * in the configuration file.
171   *
172   * Return 0 if completes successfully, -1 on error
173   */
174  int
175  res_ninit(res_state statp) {
176  	extern int __res_vinit(res_state, int);
177  	return (__res_vinit(statp, 0));
178  }
179  
180  /*% This function has to be reachable by res_data.c but not publically. */
181  int
182  __res_vinit(res_state statp, int preinit) {
183  	register FILE *fp;
184  	register char *cp, **pp;
185  	register int n;
186  	char buf[BUFSIZ];
187  	int nserv = 0;    /*%< number of nameserver records read from file */
188  	int haveenv = 0;
189  	int havesearch = 0;
190  #ifdef RESOLVSORT
191  	int nsort = 0;
192  	char *net;
193  #endif
194  	int dots;
195  	union res_sockaddr_union u[2];
196  	int maxns = MAXNS;
197  
198  	RES_SET_H_ERRNO(statp, 0);
199  	if (statp->_u._ext.ext != NULL)
200  		res_ndestroy(statp);
201  
202  	if (!preinit) {
203  		statp->retrans = RES_TIMEOUT;
204  		statp->retry = RES_DFLRETRY;
205  		statp->options = RES_DEFAULT;
206  		res_rndinit(statp);
207  		statp->id = res_nrandomid(statp);
208  	}
209  
210  	memset(u, 0, sizeof(u));
211  #ifdef USELOOPBACK
212  	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
213  #else
214  	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
215  #endif
216  	u[nserv].sin.sin_family = AF_INET;
217  	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
218  #ifdef HAVE_SA_LEN
219  	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
220  #endif
221  	nserv++;
222  #ifdef HAS_INET6_STRUCTS
223  #ifdef USELOOPBACK
224  	u[nserv].sin6.sin6_addr = in6addr_loopback;
225  #else
226  	u[nserv].sin6.sin6_addr = in6addr_any;
227  #endif
228  	u[nserv].sin6.sin6_family = AF_INET6;
229  	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
230  #ifdef HAVE_SA_LEN
231  	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
232  #endif
233  	nserv++;
234  #endif
235  	statp->nscount = 0;
236  	statp->ndots = 1;
237  	statp->pfcode = 0;
238  	statp->_vcsock = -1;
239  	statp->_flags = 0;
240  	statp->qhook = NULL;
241  	statp->rhook = NULL;
242  	statp->_u._ext.nscount = 0;
243  	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
244  	if (statp->_u._ext.ext != NULL) {
245  	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
246  		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
247  		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
248  		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
249  	} else {
250  		/*
251  		 * Historically res_init() rarely, if at all, failed.
252  		 * Examples and applications exist which do not check
253  		 * our return code.  Furthermore several applications
254  		 * simply call us to get the systems domainname.  So
255  		 * rather then immediately fail here we store the
256  		 * failure, which is returned later, in h_errno.  And
257  		 * prevent the collection of 'nameserver' information
258  		 * by setting maxns to 0.  Thus applications that fail
259  		 * to check our return code wont be able to make
260  		 * queries anyhow.
261  		 */
262  		RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
263  		maxns = 0;
264  	}
265  #ifdef RESOLVSORT
266  	statp->nsort = 0;
267  #endif
268  	res_setservers(statp, u, nserv);
269  
270  #ifdef  SUNW_INITCHKIF
271  /*
272   * Short circuit res_init() if no non-loopback interfaces are up. This is
273   * done to avoid boot delays if "dns" comes before "files" in nsswitch.conf.
274   * An additional fix has been added to this code, to count all external
275   * interfaces, which includes the IPv6 interfaces. If no external interfaces
276   * are found, an additional check is carried out to determine if any deprecated
277   * interfaces are up.
278   */
279  	{
280  		int s;
281  		struct lifnum lifn;
282  
283  		if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
284  			perror("res_init: socket");
285  			goto freedata;
286  		}
287  		lifn.lifn_family = AF_UNSPEC;
288  		lifn.lifn_flags = LIFC_EXTERNAL_SOURCE;
289  		if (ioctl(s, SIOCGLIFNUM, (char *)&lifn) < 0) {
290  			close(s);
291  			goto freedata;
292  		}
293  		if (lifn.lifn_count == 0) {
294  			/*
295  			 * Check if there are any deprecated interfaces up
296  			 */
297  			struct lifconf lifc;
298  			uchar_t *buf;
299  			int buflen, i, int_up = 0;
300  
301  			lifn.lifn_flags = 0;
302  			if ((ioctl(s, SIOCGLIFNUM, (char *)&lifn) < 0) ||
303  					(lifn.lifn_count < 1)) {
304  				close(s);
305  				goto freedata;
306  			}
307  
308  			buflen = lifn.lifn_count * sizeof (struct lifreq);
309  			buf = (uchar_t *)malloc(buflen);
310  			if (buf == NULL) {
311  				close(s);
312  				goto freedata;
313  			}
314  
315  			lifc.lifc_family = AF_UNSPEC;
316  			lifc.lifc_flags = 0;
317  			lifc.lifc_len = buflen;
318  			lifc.lifc_lifcu.lifcu_buf = (caddr_t)buf;
319  			if (ioctl(s, SIOCGLIFCONF, (char *)&lifc) < 0) {
320  				close(s);
321  				free(buf);
322  				goto freedata;
323  			}
324  
325  			for (i = 0; i < lifn.lifn_count; ++i) {
326  				struct lifreq *lreqp, lreq;
327  
328  				lreqp = (struct lifreq *)&lifc.lifc_req[i];
329  				strlcpy(lreq.lifr_name, lreqp->lifr_name,
330  						sizeof (lreq.lifr_name));
331  				if (ioctl(s, SIOCGLIFFLAGS, &lreq) < 0) {
332  					close(s);
333  					free(buf);
334  					goto freedata;
335  				}
336  				if ((lreq.lifr_flags & IFF_UP) &&
337  					!(lreq.lifr_flags & IFF_NOLOCAL) &&
338  					!(lreq.lifr_flags & IFF_NOXMIT) &&
339  					!(lreq.lifr_flags & IFF_LOOPBACK)) {
340  					int_up = 1;
341  					break;
342  				}
343  			}
344  			free(buf);
345  
346  			if (!int_up) {
347  				close(s);
348  				goto freedata;
349  			}
350  		}
351  		close(s);
352  	}
353  #endif  /* SUNW_INITCHKIF */
354  
355  #ifdef	SOLARIS2
356  	/*
357  	 * The old libresolv derived the defaultdomain from NIS/NIS+.
358  	 * We want to keep this behaviour
359  	 */
360  	{
361  		char buf[sizeof(statp->defdname)], *cp;
362  		int ret;
363  
364  		if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
365  			(unsigned int)ret <= sizeof(buf)) {
366  			if (buf[0] == '+')
367  				buf[0] = '.';
368  			cp = strchr(buf, '.');
369  			cp = (cp == NULL) ? buf : (cp + 1);
370  			strncpy(statp->defdname, cp,
371  				sizeof(statp->defdname) - 1);
372  			statp->defdname[sizeof(statp->defdname) - 1] = '\0';
373  		}
374  	}
375  #endif	/* SOLARIS2 */
376  
377  	/* Allow user to override the local domain definition */
378  	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
379  		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
380  		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
381  		haveenv++;
382  
383  		/*
384  		 * Set search list to be blank-separated strings
385  		 * from rest of env value.  Permits users of LOCALDOMAIN
386  		 * to still have a search list, and anyone to set the
387  		 * one that they want to use as an individual (even more
388  		 * important now that the rfc1535 stuff restricts searches)
389  		 */
390  		cp = statp->defdname;
391  		pp = statp->dnsrch;
392  		*pp++ = cp;
393  		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
394  			if (*cp == '\n')	/*%< silly backwards compat */
395  				break;
396  			else if (*cp == ' ' || *cp == '\t') {
397  				*cp = 0;
398  				n = 1;
399  			} else if (n) {
400  				*pp++ = cp;
401  				n = 0;
402  				havesearch = 1;
403  			}
404  		}
405  		/* null terminate last domain if there are excess */
406  		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
407  			cp++;
408  		*cp = '\0';
409  		*pp++ = 0;
410  	}
411  
412  #define	MATCH(line, name) \
413  	(!strncmp(line, name, sizeof(name) - 1) && \
414  	(line[sizeof(name) - 1] == ' ' || \
415  	 line[sizeof(name) - 1] == '\t'))
416  
417  	nserv = 0;
418  	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
419  	    /* read the config file */
420  	    while (fgets(buf, sizeof(buf), fp) != NULL) {
421  		/* skip comments */
422  		if (*buf == ';' || *buf == '#')
423  			continue;
424  		/* read default domain name */
425  		if (MATCH(buf, "domain")) {
426  		    if (haveenv)	/*%< skip if have from environ */
427  			    continue;
428  		    cp = buf + sizeof("domain") - 1;
429  		    while (*cp == ' ' || *cp == '\t')
430  			    cp++;
431  		    if ((*cp == '\0') || (*cp == '\n'))
432  			    continue;
433  		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
434  		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
435  		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
436  			    *cp = '\0';
437  		    havesearch = 0;
438  		    continue;
439  		}
440  		/* set search list */
441  		if (MATCH(buf, "search")) {
442  		    if (haveenv)	/*%< skip if have from environ */
443  			    continue;
444  		    cp = buf + sizeof("search") - 1;
445  		    while (*cp == ' ' || *cp == '\t')
446  			    cp++;
447  		    if ((*cp == '\0') || (*cp == '\n'))
448  			    continue;
449  		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
450  		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
451  		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
452  			    *cp = '\0';
453  		    /*
454  		     * Set search list to be blank-separated strings
455  		     * on rest of line.
456  		     */
457  		    cp = statp->defdname;
458  		    pp = statp->dnsrch;
459  		    *pp++ = cp;
460  		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
461  			    if (*cp == ' ' || *cp == '\t') {
462  				    *cp = 0;
463  				    n = 1;
464  			    } else if (n) {
465  				    *pp++ = cp;
466  				    n = 0;
467  			    }
468  		    }
469  		    /* null terminate last domain if there are excess */
470  		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
471  			    cp++;
472  		    *cp = '\0';
473  		    *pp++ = 0;
474  		    havesearch = 1;
475  		    continue;
476  		}
477  		/* read nameservers to query */
478  		if (MATCH(buf, "nameserver") && nserv < maxns) {
479  		    struct addrinfo hints, *ai;
480  		    char sbuf[NI_MAXSERV];
481  		    const size_t minsiz =
482  		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
483  
484  		    cp = buf + sizeof("nameserver") - 1;
485  		    while (*cp == ' ' || *cp == '\t')
486  			cp++;
487  		    cp[strcspn(cp, ";# \t\n")] = '\0';
488  		    if ((*cp != '\0') && (*cp != '\n')) {
489  			memset(&hints, 0, sizeof(hints));
490  			hints.ai_family = PF_UNSPEC;
491  			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
492  			hints.ai_flags = AI_NUMERICHOST;
493  			sprintf(sbuf, "%u", NAMESERVER_PORT);
494  			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
495  			    ai->ai_addrlen <= minsiz) {
496  			    if (statp->_u._ext.ext != NULL) {
497  				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
498  				    ai->ai_addr, ai->ai_addrlen);
499  			    }
500  			    if (ai->ai_addrlen <=
501  			        sizeof(statp->nsaddr_list[nserv])) {
502  				memcpy(&statp->nsaddr_list[nserv],
503  				    ai->ai_addr, ai->ai_addrlen);
504  			    } else
505  				statp->nsaddr_list[nserv].sin_family = 0;
506  			    freeaddrinfo(ai);
507  			    nserv++;
508  			}
509  		    }
510  		    continue;
511  		}
512  #ifdef RESOLVSORT
513  		if (MATCH(buf, "sortlist")) {
514  		    struct in_addr a;
515  
516  		    cp = buf + sizeof("sortlist") - 1;
517  		    while (nsort < MAXRESOLVSORT) {
518  			while (*cp == ' ' || *cp == '\t')
519  			    cp++;
520  			if (*cp == '\0' || *cp == '\n' || *cp == ';')
521  			    break;
522  			net = cp;
523  			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
524  			       isascii(*cp) && !isspace((unsigned char)*cp))
525  				cp++;
526  			n = *cp;
527  			*cp = 0;
528  			if (inet_aton(net, &a)) {
529  			    statp->sort_list[nsort].addr = a;
530  			    if (ISSORTMASK(n)) {
531  				*cp++ = n;
532  				net = cp;
533  				while (*cp && *cp != ';' &&
534  					isascii(*cp) &&
535  					!isspace((unsigned char)*cp))
536  				    cp++;
537  				n = *cp;
538  				*cp = 0;
539  				if (inet_aton(net, &a)) {
540  				    statp->sort_list[nsort].mask = a.s_addr;
541  				} else {
542  				    statp->sort_list[nsort].mask =
543  					net_mask(statp->sort_list[nsort].addr);
544  				}
545  			    } else {
546  				statp->sort_list[nsort].mask =
547  				    net_mask(statp->sort_list[nsort].addr);
548  			    }
549  			    nsort++;
550  			}
551  			*cp = n;
552  		    }
553  		    continue;
554  		}
555  #endif
556  		if (MATCH(buf, "options")) {
557  		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
558  		    continue;
559  		}
560  	    }
561  	    if (nserv > 0)
562  		statp->nscount = nserv;
563  #ifdef RESOLVSORT
564  	    statp->nsort = nsort;
565  #endif
566  	    (void) fclose(fp);
567  	}
568  /*
569   * Last chance to get a nameserver.  This should not normally
570   * be necessary
571   */
572  #ifdef NO_RESOLV_CONF
573  	if(nserv == 0)
574  		nserv = get_nameservers(statp);
575  #endif
576  
577  	if (statp->defdname[0] == 0 &&
578  	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
579  	    (cp = strchr(buf, '.')) != NULL)
580  		strcpy(statp->defdname, cp + 1);
581  
582  	/* find components of local domain that might be searched */
583  	if (havesearch == 0) {
584  		pp = statp->dnsrch;
585  		*pp++ = statp->defdname;
586  		*pp = NULL;
587  
588  		dots = 0;
589  		for (cp = statp->defdname; *cp; cp++)
590  			dots += (*cp == '.');
591  
592  		cp = statp->defdname;
593  		while (pp < statp->dnsrch + MAXDFLSRCH) {
594  			if (dots < LOCALDOMAINPARTS)
595  				break;
596  			cp = strchr(cp, '.') + 1;    /*%< we know there is one */
597  			*pp++ = cp;
598  			dots--;
599  		}
600  		*pp = NULL;
601  #ifdef DEBUG
602  		if (statp->options & RES_DEBUG) {
603  			printf(";; res_init()... default dnsrch list:\n");
604  			for (pp = statp->dnsrch; *pp; pp++)
605  				printf(";;\t%s\n", *pp);
606  			printf(";;\t..END..\n");
607  		}
608  #endif
609  	}
610  
611  	if ((cp = getenv("RES_OPTIONS")) != NULL)
612  		res_setoptions(statp, cp, "env");
613  	statp->options |= RES_INIT;
614  	return (statp->res_h_errno);
615  #ifdef  SUNW_INITCHKIF
616  freedata:
617  	RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
618  	if (statp->_u._ext.ext != NULL) {
619  		free(statp->_u._ext.ext);
620  		statp->_u._ext.ext = NULL;
621  	}
622  	return (-1);
623  #endif  /* SUNW_INITCHKIF */
624  
625  }
626  
627  static void
628  res_setoptions(res_state statp, const char *options, const char *source)
629  {
630  	const char *cp = options;
631  	int i;
632  	struct __res_state_ext *ext = statp->_u._ext.ext;
633  
634  #ifdef DEBUG
635  	if (statp->options & RES_DEBUG)
636  		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
637  		       options, source);
638  #endif
639  	while (*cp) {
640  		/* skip leading and inner runs of spaces */
641  		while (*cp == ' ' || *cp == '\t')
642  			cp++;
643  		/* search for and process individual options */
644  		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
645  			i = atoi(cp + sizeof("ndots:") - 1);
646  			if (i <= RES_MAXNDOTS)
647  				statp->ndots = i;
648  			else
649  				statp->ndots = RES_MAXNDOTS;
650  #ifdef DEBUG
651  			if (statp->options & RES_DEBUG)
652  				printf(";;\tndots=%d\n", statp->ndots);
653  #endif
654  		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
655  			i = atoi(cp + sizeof("timeout:") - 1);
656  			if (i <= RES_MAXRETRANS)
657  				statp->retrans = i;
658  			else
659  				statp->retrans = RES_MAXRETRANS;
660  #ifdef DEBUG
661  			if (statp->options & RES_DEBUG)
662  				printf(";;\ttimeout=%d\n", statp->retrans);
663  #endif
664  #ifdef	SOLARIS2
665  		} else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
666  			/*
667  		 	 * For backward compatibility, 'retrans' is
668  		 	 * supported as an alias for 'timeout', though
669  		 	 * without an imposed maximum.
670  		 	 */
671  			statp->retrans = atoi(cp + sizeof("retrans:") - 1);
672  		} else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
673  			/*
674  			 * For backward compatibility, 'retry' is
675  			 * supported as an alias for 'attempts', though
676  			 * without an imposed maximum.
677  			 */
678  			statp->retry = atoi(cp + sizeof("retry:") - 1);
679  #endif	/* SOLARIS2 */
680  		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
681  			i = atoi(cp + sizeof("attempts:") - 1);
682  			if (i <= RES_MAXRETRY)
683  				statp->retry = i;
684  			else
685  				statp->retry = RES_MAXRETRY;
686  #ifdef DEBUG
687  			if (statp->options & RES_DEBUG)
688  				printf(";;\tattempts=%d\n", statp->retry);
689  #endif
690  		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
691  #ifdef DEBUG
692  			if (!(statp->options & RES_DEBUG)) {
693  				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
694  				       options, source);
695  				statp->options |= RES_DEBUG;
696  			}
697  			printf(";;\tdebug\n");
698  #endif
699  		} else if (!strncmp(cp, "no_tld_query",
700  				    sizeof("no_tld_query") - 1) ||
701  			   !strncmp(cp, "no-tld-query",
702  				    sizeof("no-tld-query") - 1)) {
703  			statp->options |= RES_NOTLDQUERY;
704  		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
705  			statp->options |= RES_USE_INET6;
706  		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
707  			statp->options |= RES_ROTATE;
708  		} else if (!strncmp(cp, "no-check-names",
709  				    sizeof("no-check-names") - 1)) {
710  			statp->options |= RES_NOCHECKNAME;
711  		}
712  #ifdef RES_USE_EDNS0
713  		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
714  			statp->options |= RES_USE_EDNS0;
715  		}
716  #endif
717  		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
718  			statp->options |= RES_USE_DNAME;
719  		}
720  		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
721  			if (ext == NULL)
722  				goto skip;
723  			cp += sizeof("nibble:") - 1;
724  			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
725  			strncpy(ext->nsuffix, cp, i);
726  			ext->nsuffix[i] = '\0';
727  		}
728  		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
729  			if (ext == NULL)
730  				goto skip;
731  			cp += sizeof("nibble2:") - 1;
732  			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
733  			strncpy(ext->nsuffix2, cp, i);
734  			ext->nsuffix2[i] = '\0';
735  		}
736  		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
737  			cp += sizeof("v6revmode:") - 1;
738  			/* "nibble" and "bitstring" used to be valid */
739  			if (!strncmp(cp, "single", sizeof("single") - 1)) {
740  				statp->options |= RES_NO_NIBBLE2;
741  			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
742  				statp->options &=
743  					 ~RES_NO_NIBBLE2;
744  			}
745  		}
746  		else {
747  			/* XXX - print a warning here? */
748  		}
749     skip:
750  		/* skip to next run of spaces */
751  		while (*cp && *cp != ' ' && *cp != '\t')
752  			cp++;
753  	}
754  }
755  
756  #ifdef RESOLVSORT
757  /* XXX - should really support CIDR which means explicit masks always. */
758  static u_int32_t
759  net_mask(in)		/*!< XXX - should really use system's version of this  */
760  	struct in_addr in;
761  {
762  	register u_int32_t i = ntohl(in.s_addr);
763  
764  	if (IN_CLASSA(i))
765  		return (htonl(IN_CLASSA_NET));
766  	else if (IN_CLASSB(i))
767  		return (htonl(IN_CLASSB_NET));
768  	return (htonl(IN_CLASSC_NET));
769  }
770  #endif
771  
772  void
773  res_rndinit(res_state statp)
774  {
775  	struct timeval now;
776  	u_int32_t u32;
777  	u_int16_t u16;
778  
779  	gettimeofday(&now, NULL);
780  	u32 = now.tv_sec;
781  	memcpy(statp->_u._ext._rnd, &u32, 4);
782  	u32 = now.tv_usec;
783  	memcpy(statp->_u._ext._rnd + 4, &u32, 4);
784  	u32 += now.tv_sec;
785  	memcpy(statp->_u._ext._rnd + 8, &u32, 4);
786  	u16 = getpid();
787  	memcpy(statp->_u._ext._rnd + 12, &u16, 2);
788  
789  }
790  
791  u_int
792  res_nrandomid(res_state statp) {
793  	struct timeval now;
794  	u_int16_t u16;
795  	MD5_CTX ctx;
796  
797  	gettimeofday(&now, NULL);
798  	u16 = (u_int16_t) (now.tv_sec ^ now.tv_usec);
799  
800  	memcpy(statp->_u._ext._rnd + 14, &u16, 2);
801  #ifndef HAVE_MD5
802  	MD5_Init(&ctx);
803  	MD5_Update(&ctx, statp->_u._ext._rnd, 16);
804  	MD5_Final(statp->_u._ext._rnd, &ctx);
805  #else
806  	MD5Init(&ctx);
807  	MD5Update(&ctx, statp->_u._ext._rnd, 16);
808  	MD5Final(statp->_u._ext._rnd, &ctx);
809  #endif
810  	memcpy(&u16, statp->_u._ext._rnd + 14, 2);
811  	return ((u_int) u16);
812  }
813  
814  /*%
815   * This routine is for closing the socket if a virtual circuit is used and
816   * the program wants to close it.  This provides support for endhostent()
817   * which expects to close the socket.
818   *
819   * This routine is not expected to be user visible.
820   */
821  void
822  res_nclose(res_state statp) {
823  	int ns;
824  
825  	if (statp->_vcsock >= 0) {
826  		(void) close(statp->_vcsock);
827  		statp->_vcsock = -1;
828  		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
829  	}
830  	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
831  		if (statp->_u._ext.nssocks[ns] != -1) {
832  			(void) close(statp->_u._ext.nssocks[ns]);
833  			statp->_u._ext.nssocks[ns] = -1;
834  		}
835  	}
836  }
837  
838  void
839  res_ndestroy(res_state statp) {
840  	res_nclose(statp);
841  	if (statp->_u._ext.ext != NULL)
842  		free(statp->_u._ext.ext);
843  	statp->options &= ~RES_INIT;
844  	statp->_u._ext.ext = NULL;
845  }
846  
847  const char *
848  res_get_nibblesuffix(res_state statp) {
849  	if (statp->_u._ext.ext)
850  		return (statp->_u._ext.ext->nsuffix);
851  	return ("ip6.arpa");
852  }
853  
854  const char *
855  res_get_nibblesuffix2(res_state statp) {
856  	if (statp->_u._ext.ext)
857  		return (statp->_u._ext.ext->nsuffix2);
858  	return ("ip6.int");
859  }
860  
861  void
862  res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
863  	int i, nserv;
864  	size_t size;
865  
866  	/* close open servers */
867  	res_nclose(statp);
868  
869  	/* cause rtt times to be forgotten */
870  	statp->_u._ext.nscount = 0;
871  
872  	nserv = 0;
873  	for (i = 0; i < cnt && nserv < MAXNS; i++) {
874  		switch (set->sin.sin_family) {
875  		case AF_INET:
876  			size = sizeof(set->sin);
877  			if (statp->_u._ext.ext)
878  				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
879  					&set->sin, size);
880  			if (size <= sizeof(statp->nsaddr_list[nserv]))
881  				memcpy(&statp->nsaddr_list[nserv],
882  					&set->sin, size);
883  			else
884  				statp->nsaddr_list[nserv].sin_family = 0;
885  			nserv++;
886  			break;
887  
888  #ifdef HAS_INET6_STRUCTS
889  		case AF_INET6:
890  			size = sizeof(set->sin6);
891  			if (statp->_u._ext.ext)
892  				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
893  					&set->sin6, size);
894  			if (size <= sizeof(statp->nsaddr_list[nserv]))
895  				memcpy(&statp->nsaddr_list[nserv],
896  					&set->sin6, size);
897  			else
898  				statp->nsaddr_list[nserv].sin_family = 0;
899  			nserv++;
900  			break;
901  #endif
902  
903  		default:
904  			break;
905  		}
906  		set++;
907  	}
908  	statp->nscount = nserv;
909  
910  }
911  
912  int
913  res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
914  	int i;
915  	size_t size;
916  	u_int16_t family;
917  
918  	for (i = 0; i < statp->nscount && i < cnt; i++) {
919  		if (statp->_u._ext.ext)
920  			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
921  		else
922  			family = statp->nsaddr_list[i].sin_family;
923  
924  		switch (family) {
925  		case AF_INET:
926  			size = sizeof(set->sin);
927  			if (statp->_u._ext.ext)
928  				memcpy(&set->sin,
929  				       &statp->_u._ext.ext->nsaddrs[i],
930  				       size);
931  			else
932  				memcpy(&set->sin, &statp->nsaddr_list[i],
933  				       size);
934  			break;
935  
936  #ifdef HAS_INET6_STRUCTS
937  		case AF_INET6:
938  			size = sizeof(set->sin6);
939  			if (statp->_u._ext.ext)
940  				memcpy(&set->sin6,
941  				       &statp->_u._ext.ext->nsaddrs[i],
942  				       size);
943  			else
944  				memcpy(&set->sin6, &statp->nsaddr_list[i],
945  				       size);
946  			break;
947  #endif
948  
949  		default:
950  			set->sin.sin_family = 0;
951  			break;
952  		}
953  		set++;
954  	}
955  	return (statp->nscount);
956  }
957  
958  /*! \file */
959