res_init.c revision c39214e0ac49b9f7de6fd9989331145c6e1cd584
1/*	$NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $	*/
2
3/*
4 * Copyright (c) 1985, 1989, 1993
5 *    The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 * 	This product includes software developed by the University of
18 * 	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36/*
37 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
38 *
39 * Permission to use, copy, modify, and distribute this software for any
40 * purpose with or without fee is hereby granted, provided that the above
41 * copyright notice and this permission notice appear in all copies, and that
42 * the name of Digital Equipment Corporation not be used in advertising or
43 * publicity pertaining to distribution of the document or software without
44 * specific, written prior permission.
45 *
46 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
47 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
48 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
49 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
50 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
51 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
52 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
53 * SOFTWARE.
54 */
55
56/*
57 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
58 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
59 *
60 * Permission to use, copy, modify, and distribute this software for any
61 * purpose with or without fee is hereby granted, provided that the above
62 * copyright notice and this permission notice appear in all copies.
63 *
64 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
65 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
66 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
67 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
68 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
69 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
70 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
71 */
72
73#include <sys/cdefs.h>
74#if defined(LIBC_SCCS) && !defined(lint)
75#ifdef notdef
76static const char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
77static const char rcsid[] = "Id: res_init.c,v 1.9.2.5.4.2 2004/03/16 12:34:18 marka Exp";
78#else
79__RCSID("$NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $");
80#endif
81#endif /* LIBC_SCCS and not lint */
82
83
84
85#include <sys/types.h>
86#include <sys/param.h>
87#include <sys/socket.h>
88#include <sys/time.h>
89
90#include <netinet/in.h>
91#include <arpa/inet.h>
92#include "arpa_nameser.h"
93
94#include <ctype.h>
95#include <stdio.h>
96#include <stdlib.h>
97#include <string.h>
98#include <unistd.h>
99#include <netdb.h>
100
101#ifdef ANDROID_CHANGES
102#include <errno.h>
103#include <fcntl.h>
104#include <sys/system_properties.h>
105#endif /* ANDROID_CHANGES */
106
107#ifndef MIN
108#define	MIN(x,y)	((x)<(y)?(x):(y))
109#endif
110
111/* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
112#ifdef ANDROID_CHANGES
113#include "resolv_private.h"
114#else
115#include <resolv.h>
116#endif
117
118#include "res_private.h"
119
120/* Options.  Should all be left alone. */
121#ifndef DEBUG
122#define DEBUG
123#endif
124
125static void res_setoptions __P((res_state, const char *, const char *));
126
127static const char sort_mask[] = "/&";
128#define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
129static u_int32_t net_mask __P((struct in_addr));
130
131#if !defined(isascii)	/* XXX - could be a function */
132# define isascii(c) (!(c & 0200))
133#endif
134
135/*
136 * Resolver state default settings.
137 */
138
139/*
140 * Set up default settings.  If the configuration file exist, the values
141 * there will have precedence.  Otherwise, the server address is set to
142 * INADDR_ANY and the default domain name comes from the gethostname().
143 *
144 * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
145 * rather than INADDR_ANY ("0.0.0.0") as the default name server address
146 * since it was noted that INADDR_ANY actually meant ``the first interface
147 * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
148 * it had to be "up" in order for you to reach your own name server.  It
149 * was later decided that since the recommended practice is to always
150 * install local static routes through 127.0.0.1 for all your network
151 * interfaces, that we could solve this problem without a code change.
152 *
153 * The configuration file should always be used, since it is the only way
154 * to specify a default domain.  If you are running a server on your local
155 * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
156 * in the configuration file.
157 *
158 * Return 0 if completes successfully, -1 on error
159 */
160int
161res_ninit(res_state statp) {
162	extern int __res_vinit(res_state, int);
163
164	return (__res_vinit(statp, 0));
165}
166
167/* This function has to be reachable by res_data.c but not publicly. */
168int
169__res_vinit(res_state statp, int preinit) {
170	register FILE *fp;
171	register char *cp, **pp;
172	register int n;
173	char buf[BUFSIZ];
174	int nserv = 0;    /* number of nameserver records read from file */
175	int haveenv = 0;
176	int havesearch = 0;
177	int nsort = 0;
178	char *net;
179	int dots;
180	union res_sockaddr_union u[2];
181
182        if ((statp->options & RES_INIT) != 0U)
183                res_ndestroy(statp);
184
185	if (!preinit) {
186		statp->retrans = RES_TIMEOUT;
187		statp->retry = RES_DFLRETRY;
188		statp->options = RES_DEFAULT;
189		statp->id = res_randomid();
190	}
191
192	memset(u, 0, sizeof(u));
193#ifdef USELOOPBACK
194	u[nserv].sin.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
195#else
196	u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
197#endif
198	u[nserv].sin.sin_family = AF_INET;
199	u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
200#ifdef HAVE_SA_LEN
201	u[nserv].sin.sin_len = sizeof(struct sockaddr_in);
202#endif
203	nserv++;
204#ifdef HAS_INET6_STRUCTS
205#ifdef USELOOPBACK
206	u[nserv].sin6.sin6_addr = in6addr_loopback;
207#else
208	u[nserv].sin6.sin6_addr = in6addr_any;
209#endif
210	u[nserv].sin6.sin6_family = AF_INET6;
211	u[nserv].sin6.sin6_port = htons(NAMESERVER_PORT);
212#ifdef HAVE_SA_LEN
213	u[nserv].sin6.sin6_len = sizeof(struct sockaddr_in6);
214#endif
215	nserv++;
216#endif
217	statp->nscount = 0;
218	statp->ndots = 1;
219	statp->pfcode = 0;
220	statp->_vcsock = -1;
221	statp->_flags = 0;
222	statp->qhook = NULL;
223	statp->rhook = NULL;
224	statp->_u._ext.nscount = 0;
225	statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
226	if (statp->_u._ext.ext != NULL) {
227	        memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
228		statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
229		strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
230		strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
231	}
232	statp->nsort = 0;
233	res_setservers(statp, u, nserv);
234
235#if 0 /* IGNORE THE ENVIRONMENT */
236	/* Allow user to override the local domain definition */
237	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
238		(void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
239		statp->defdname[sizeof(statp->defdname) - 1] = '\0';
240		haveenv++;
241
242		/*
243		 * Set search list to be blank-separated strings
244		 * from rest of env value.  Permits users of LOCALDOMAIN
245		 * to still have a search list, and anyone to set the
246		 * one that they want to use as an individual (even more
247		 * important now that the rfc1535 stuff restricts searches)
248		 */
249		cp = statp->defdname;
250		pp = statp->dnsrch;
251		*pp++ = cp;
252		for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
253			if (*cp == '\n')	/* silly backwards compat */
254				break;
255			else if (*cp == ' ' || *cp == '\t') {
256				*cp = 0;
257				n = 1;
258			} else if (n) {
259				*pp++ = cp;
260				n = 0;
261				havesearch = 1;
262			}
263		}
264		/* null terminate last domain if there are excess */
265		while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
266			cp++;
267		*cp = '\0';
268		*pp++ = 0;
269	}
270	if (nserv > 0)
271		statp->nscount = nserv;
272#endif
273
274#ifndef ANDROID_CHANGES /* !ANDROID_CHANGES - IGNORE resolv.conf in Android */
275#define	MATCH(line, name) \
276	(!strncmp(line, name, sizeof(name) - 1) && \
277	(line[sizeof(name) - 1] == ' ' || \
278	 line[sizeof(name) - 1] == '\t'))
279
280	nserv = 0;
281	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
282	    /* read the config file */
283	    while (fgets(buf, sizeof(buf), fp) != NULL) {
284		/* skip comments */
285		if (*buf == ';' || *buf == '#')
286			continue;
287		/* read default domain name */
288		if (MATCH(buf, "domain")) {
289		    if (haveenv)	/* skip if have from environ */
290			    continue;
291		    cp = buf + sizeof("domain") - 1;
292		    while (*cp == ' ' || *cp == '\t')
293			    cp++;
294		    if ((*cp == '\0') || (*cp == '\n'))
295			    continue;
296		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
297		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
298		    if ((cp = strpbrk(statp->defdname, " \t\n")) != NULL)
299			    *cp = '\0';
300		    havesearch = 0;
301		    continue;
302		}
303		/* set search list */
304		if (MATCH(buf, "search")) {
305		    if (haveenv)	/* skip if have from environ */
306			    continue;
307		    cp = buf + sizeof("search") - 1;
308		    while (*cp == ' ' || *cp == '\t')
309			    cp++;
310		    if ((*cp == '\0') || (*cp == '\n'))
311			    continue;
312		    strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
313		    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
314		    if ((cp = strchr(statp->defdname, '\n')) != NULL)
315			    *cp = '\0';
316		    /*
317		     * Set search list to be blank-separated strings
318		     * on rest of line.
319		     */
320		    cp = statp->defdname;
321		    pp = statp->dnsrch;
322		    *pp++ = cp;
323		    for (n = 0; *cp && pp < statp->dnsrch + MAXDNSRCH; cp++) {
324			    if (*cp == ' ' || *cp == '\t') {
325				    *cp = 0;
326				    n = 1;
327			    } else if (n) {
328				    *pp++ = cp;
329				    n = 0;
330			    }
331		    }
332		    /* null terminate last domain if there are excess */
333		    while (*cp != '\0' && *cp != ' ' && *cp != '\t')
334			    cp++;
335		    *cp = '\0';
336		    *pp++ = 0;
337		    havesearch = 1;
338		    continue;
339		}
340		/* read nameservers to query */
341		if (MATCH(buf, "nameserver") && nserv < MAXNS) {
342		    struct addrinfo hints, *ai;
343		    char sbuf[NI_MAXSERV];
344		    const size_t minsiz =
345		        sizeof(statp->_u._ext.ext->nsaddrs[0]);
346
347		    cp = buf + sizeof("nameserver") - 1;
348		    while (*cp == ' ' || *cp == '\t')
349			cp++;
350		    cp[strcspn(cp, ";# \t\n")] = '\0';
351		    if ((*cp != '\0') && (*cp != '\n')) {
352			memset(&hints, 0, sizeof(hints));
353			hints.ai_family = PF_UNSPEC;
354			hints.ai_socktype = SOCK_DGRAM;	/*dummy*/
355			hints.ai_flags = AI_NUMERICHOST;
356			sprintf(sbuf, "%u", NAMESERVER_PORT);
357			if (getaddrinfo(cp, sbuf, &hints, &ai) == 0 &&
358			    ai->ai_addrlen <= minsiz) {
359			    if (statp->_u._ext.ext != NULL) {
360				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
361				    ai->ai_addr, ai->ai_addrlen);
362			    }
363			    if (ai->ai_addrlen <=
364			        sizeof(statp->nsaddr_list[nserv])) {
365				memcpy(&statp->nsaddr_list[nserv],
366				    ai->ai_addr, ai->ai_addrlen);
367			    } else
368				statp->nsaddr_list[nserv].sin_family = 0;
369			    freeaddrinfo(ai);
370			    nserv++;
371			}
372		    }
373		    continue;
374		}
375		if (MATCH(buf, "sortlist")) {
376		    struct in_addr a;
377
378		    cp = buf + sizeof("sortlist") - 1;
379		    while (nsort < MAXRESOLVSORT) {
380			while (*cp == ' ' || *cp == '\t')
381			    cp++;
382			if (*cp == '\0' || *cp == '\n' || *cp == ';')
383			    break;
384			net = cp;
385			while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
386			       isascii(*cp) && !isspace((unsigned char)*cp))
387				cp++;
388			n = *cp;
389			*cp = 0;
390			if (inet_aton(net, &a)) {
391			    statp->sort_list[nsort].addr = a;
392			    if (ISSORTMASK(n)) {
393				*cp++ = n;
394				net = cp;
395				while (*cp && *cp != ';' &&
396					isascii(*cp) &&
397					!isspace((unsigned char)*cp))
398				    cp++;
399				n = *cp;
400				*cp = 0;
401				if (inet_aton(net, &a)) {
402				    statp->sort_list[nsort].mask = a.s_addr;
403				} else {
404				    statp->sort_list[nsort].mask =
405					net_mask(statp->sort_list[nsort].addr);
406				}
407			    } else {
408				statp->sort_list[nsort].mask =
409				    net_mask(statp->sort_list[nsort].addr);
410			    }
411			    nsort++;
412			}
413			*cp = n;
414		    }
415		    continue;
416		}
417		if (MATCH(buf, "options")) {
418		    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
419		    continue;
420		}
421	    }
422	    if (nserv > 0)
423		statp->nscount = nserv;
424	    statp->nsort = nsort;
425	    (void) fclose(fp);
426	}
427#endif /* !ANDROID_CHANGES */
428/*
429 * Last chance to get a nameserver.  This should not normally
430 * be necessary
431 */
432#ifdef NO_RESOLV_CONF
433	if(nserv == 0)
434		nserv = get_nameservers(statp);
435#endif
436
437	if (statp->defdname[0] == 0 &&
438	    gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
439	    (cp = strchr(buf, '.')) != NULL)
440		strcpy(statp->defdname, cp + 1);
441
442	/* find components of local domain that might be searched */
443	if (havesearch == 0) {
444		pp = statp->dnsrch;
445		*pp++ = statp->defdname;
446		*pp = NULL;
447
448		dots = 0;
449		for (cp = statp->defdname; *cp; cp++)
450			dots += (*cp == '.');
451
452		cp = statp->defdname;
453		while (pp < statp->dnsrch + MAXDFLSRCH) {
454			if (dots < LOCALDOMAINPARTS)
455				break;
456			cp = strchr(cp, '.') + 1;    /* we know there is one */
457			*pp++ = cp;
458			dots--;
459		}
460		*pp = NULL;
461#ifdef DEBUG
462		if (statp->options & RES_DEBUG) {
463			printf(";; res_init()... default dnsrch list:\n");
464			for (pp = statp->dnsrch; *pp; pp++)
465				printf(";;\t%s\n", *pp);
466			printf(";;\t..END..\n");
467		}
468#endif
469	}
470
471	if ((cp = getenv("RES_OPTIONS")) != NULL)
472		res_setoptions(statp, cp, "env");
473	if (nserv > 0) {
474		statp->nscount = nserv;
475		statp->options |= RES_INIT;
476	}
477	return (0);
478}
479
480static void
481res_setoptions(res_state statp, const char *options, const char *source)
482{
483	const char *cp = options;
484	int i;
485	struct __res_state_ext *ext = statp->_u._ext.ext;
486
487#ifdef DEBUG
488	if (statp->options & RES_DEBUG)
489		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
490		       options, source);
491#endif
492	while (*cp) {
493		/* skip leading and inner runs of spaces */
494		while (*cp == ' ' || *cp == '\t')
495			cp++;
496		/* search for and process individual options */
497		if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
498			i = atoi(cp + sizeof("ndots:") - 1);
499			if (i <= RES_MAXNDOTS)
500				statp->ndots = i;
501			else
502				statp->ndots = RES_MAXNDOTS;
503#ifdef DEBUG
504			if (statp->options & RES_DEBUG)
505				printf(";;\tndots=%d\n", statp->ndots);
506#endif
507		} else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
508			i = atoi(cp + sizeof("timeout:") - 1);
509			if (i <= RES_MAXRETRANS)
510				statp->retrans = i;
511			else
512				statp->retrans = RES_MAXRETRANS;
513#ifdef DEBUG
514			if (statp->options & RES_DEBUG)
515				printf(";;\ttimeout=%d\n", statp->retrans);
516#endif
517		} else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
518			i = atoi(cp + sizeof("attempts:") - 1);
519			if (i <= RES_MAXRETRY)
520				statp->retry = i;
521			else
522				statp->retry = RES_MAXRETRY;
523#ifdef DEBUG
524			if (statp->options & RES_DEBUG)
525				printf(";;\tattempts=%d\n", statp->retry);
526#endif
527		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
528#ifdef DEBUG
529			if (!(statp->options & RES_DEBUG)) {
530				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
531				       options, source);
532				statp->options |= RES_DEBUG;
533			}
534			printf(";;\tdebug\n");
535#endif
536		} else if (!strncmp(cp, "no_tld_query",
537				    sizeof("no_tld_query") - 1) ||
538			   !strncmp(cp, "no-tld-query",
539				    sizeof("no-tld-query") - 1)) {
540			statp->options |= RES_NOTLDQUERY;
541		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
542			statp->options |= RES_USE_INET6;
543		} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
544			statp->options |= RES_ROTATE;
545		} else if (!strncmp(cp, "no-check-names",
546				    sizeof("no-check-names") - 1)) {
547			statp->options |= RES_NOCHECKNAME;
548		}
549#ifdef RES_USE_EDNS0
550		else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
551			statp->options |= RES_USE_EDNS0;
552		}
553#endif
554		else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
555			statp->options |= RES_USE_DNAME;
556		}
557		else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
558			if (ext == NULL)
559				goto skip;
560			cp += sizeof("nibble:") - 1;
561			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
562			strncpy(ext->nsuffix, cp, (size_t)i);
563			ext->nsuffix[i] = '\0';
564		}
565		else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
566			if (ext == NULL)
567				goto skip;
568			cp += sizeof("nibble2:") - 1;
569			i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
570			strncpy(ext->nsuffix2, cp, (size_t)i);
571			ext->nsuffix2[i] = '\0';
572		}
573		else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
574			cp += sizeof("v6revmode:") - 1;
575			/* "nibble" and "bitstring" used to be valid */
576			if (!strncmp(cp, "single", sizeof("single") - 1)) {
577				statp->options |= RES_NO_NIBBLE2;
578			} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
579				statp->options &=
580					 ~RES_NO_NIBBLE2;
581			}
582		}
583		else {
584			/* XXX - print a warning here? */
585		}
586   skip:
587		/* skip to next run of spaces */
588		while (*cp && *cp != ' ' && *cp != '\t')
589			cp++;
590	}
591}
592
593/* XXX - should really support CIDR which means explicit masks always. */
594static u_int32_t
595net_mask(in)		/* XXX - should really use system's version of this */
596	struct in_addr in;
597{
598	register u_int32_t i = ntohl(in.s_addr);
599
600	if (IN_CLASSA(i))
601		return (htonl(IN_CLASSA_NET));
602	else if (IN_CLASSB(i))
603		return (htonl(IN_CLASSB_NET));
604	return (htonl(IN_CLASSC_NET));
605}
606
607#ifdef ANDROID_CHANGES
608static int
609real_randomid(u_int *random_value) {
610	/* open the nonblocking random device, returning -1 on failure */
611	int random_device = open("/dev/urandom", O_RDONLY);
612	if (random_device < 0) {
613		return -1;
614	}
615
616	/* read from the random device, returning -1 on failure (or too many retries)*/
617	u_int retry = 5;
618	for (retry; retry > 0; retry--) {
619		int retval = read(random_device, random_value, sizeof(u_int));
620		if (retval == sizeof(u_int)) {
621			*random_value &= 0xffff;
622			close(random_device);
623			return 0;
624		} else if ((retval < 0) && (errno != EINTR)) {
625			break;
626		}
627	}
628
629	close(random_device);
630	return -1;
631}
632#endif /* ANDROID_CHANGES */
633
634u_int
635res_randomid(void) {
636#ifdef ANDROID_CHANGES
637	int status = 0;
638	u_int output = 0;
639	status = real_randomid(&output);
640	if (status != -1) {
641		return output;
642	}
643#endif /* ANDROID_CHANGES */
644	struct timeval now;
645	gettimeofday(&now, NULL);
646	return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
647}
648
649/*
650 * This routine is for closing the socket if a virtual circuit is used and
651 * the program wants to close it.  This provides support for endhostent()
652 * which expects to close the socket.
653 *
654 * This routine is not expected to be user visible.
655 */
656void
657res_nclose(res_state statp) {
658	int ns;
659
660	if (statp->_vcsock >= 0) {
661		(void) close(statp->_vcsock);
662		statp->_vcsock = -1;
663		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
664	}
665	for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
666		if (statp->_u._ext.nssocks[ns] != -1) {
667			(void) close(statp->_u._ext.nssocks[ns]);
668			statp->_u._ext.nssocks[ns] = -1;
669		}
670	}
671}
672
673void
674res_ndestroy(res_state statp) {
675	res_nclose(statp);
676	if (statp->_u._ext.ext != NULL)
677		free(statp->_u._ext.ext);
678	statp->options &= ~RES_INIT;
679	statp->_u._ext.ext = NULL;
680}
681
682const char *
683res_get_nibblesuffix(res_state statp) {
684	if (statp->_u._ext.ext)
685		return (statp->_u._ext.ext->nsuffix);
686	return ("ip6.arpa");
687}
688
689const char *
690res_get_nibblesuffix2(res_state statp) {
691	if (statp->_u._ext.ext)
692		return (statp->_u._ext.ext->nsuffix2);
693	return ("ip6.int");
694}
695
696void
697res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
698	int i, nserv;
699	size_t size;
700
701	/* close open servers */
702	res_nclose(statp);
703
704	/* cause rtt times to be forgotten */
705	statp->_u._ext.nscount = 0;
706
707	nserv = 0;
708	for (i = 0; i < cnt && nserv < MAXNS; i++) {
709		switch (set->sin.sin_family) {
710		case AF_INET:
711			size = sizeof(set->sin);
712			if (statp->_u._ext.ext)
713				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
714					&set->sin, size);
715			if (size <= sizeof(statp->nsaddr_list[nserv]))
716				memcpy(&statp->nsaddr_list[nserv],
717					&set->sin, size);
718#ifdef notdef
719			else
720				statp->nsaddr_list[nserv].sin_family = 0;
721#endif
722			nserv++;
723			break;
724
725#ifdef HAS_INET6_STRUCTS
726		case AF_INET6:
727			size = sizeof(set->sin6);
728			if (statp->_u._ext.ext)
729				memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
730					&set->sin6, size);
731			if (size <= sizeof(statp->nsaddr_list[nserv]))
732				memcpy(&statp->nsaddr_list[nserv],
733					&set->sin6, size);
734			else
735				statp->nsaddr_list[nserv].sin_family = 0;
736			nserv++;
737			break;
738#endif
739
740		default:
741			break;
742		}
743		set++;
744	}
745	statp->nscount = nserv;
746
747}
748
749int
750res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
751	int i;
752	size_t size;
753	u_int16_t family;
754
755	for (i = 0; i < statp->nscount && i < cnt; i++) {
756		if (statp->_u._ext.ext)
757			family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
758		else
759			family = statp->nsaddr_list[i].sin_family;
760
761		switch (family) {
762		case AF_INET:
763			size = sizeof(set->sin);
764			if (statp->_u._ext.ext)
765				memcpy(&set->sin,
766				       &statp->_u._ext.ext->nsaddrs[i],
767				       size);
768			else
769				memcpy(&set->sin, &statp->nsaddr_list[i],
770				       size);
771			break;
772
773#ifdef HAS_INET6_STRUCTS
774		case AF_INET6:
775			size = sizeof(set->sin6);
776			if (statp->_u._ext.ext)
777				memcpy(&set->sin6,
778				       &statp->_u._ext.ext->nsaddrs[i],
779				       size);
780			else
781				memcpy(&set->sin6, &statp->nsaddr_list[i],
782				       size);
783			break;
784#endif
785
786		default:
787			set->sin.sin_family = 0;
788			break;
789		}
790		set++;
791	}
792	return (statp->nscount);
793}
794
795#ifdef ANDROID_CHANGES
796void res_setiface(res_state statp, const char* iface)
797{
798	if (statp != NULL) {
799		// set interface
800		if (iface && iface[0] != '\0') {
801			int len = sizeof(statp->iface);
802			strncpy(statp->iface, iface, len - 1);
803			statp->iface[len - 1] = '\0';
804		} else {
805			statp->iface[0] = '\0';
806		}
807	}
808}
809
810void res_setmark(res_state statp, int mark)
811{
812	if (statp != NULL) {
813		statp->_mark = mark;
814	}
815}
816#endif /* ANDROID_CHANGES */
817