1/*
2 * ++Copyright++ 1985, 1988, 1993
3 * -
4 * Copyright (c) 1985, 1988, 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 * 4. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 * -
31 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
32 *
33 * Permission to use, copy, modify, and distribute this software for any
34 * purpose with or without fee is hereby granted, provided that the above
35 * copyright notice and this permission notice appear in all copies, and that
36 * the name of Digital Equipment Corporation not be used in advertising or
37 * publicity pertaining to distribution of the document or software without
38 * specific, written prior permission.
39 *
40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
47 * SOFTWARE.
48 * -
49 * --Copyright--
50 */
51
52/* XXX This file is not used by any of the resolver functions implemented by
53 glibc (i.e. get*info and gethostby*). It cannot be removed however because
54 it exports symbols in the libresolv ABI. The file is not maintained any
55 more, nor are these functions. */
56
57#include <shlib-compat.h>
58#if SHLIB_COMPAT (libresolv, GLIBC_2_0, GLIBC_2_25)
59
60# include <sys/types.h>
61# include <sys/param.h>
62# include <sys/socket.h>
63# include <netinet/in.h>
64# include <arpa/inet.h>
65# include <arpa/nameser.h>
66
67# include <stdio.h>
68# include <netdb.h>
69# include <resolv/resolv-internal.h>
70# include <resolv/resolv_context.h>
71# include <ctype.h>
72# include <errno.h>
73# include <stdlib.h>
74# include <string.h>
75
76# define MAXALIASES 35
77# define MAXADDRS 35
78
79static char *h_addr_ptrs[MAXADDRS + 1];
80
81static struct hostent host;
82static char *host_aliases[MAXALIASES];
83static char hostbuf[8*1024];
84static u_char host_addr[16]; /* IPv4 or IPv6 */
85static FILE *hostf = NULL;
86static int stayopen = 0;
87
88static struct hostent *res_gethostbyname2_context (struct resolv_context *,
89 const char *name, int af);
90
91static void map_v4v6_address (const char *src, char *dst) __THROW;
92static void map_v4v6_hostent (struct hostent *hp, char **bp, int *len) __THROW;
93
94extern void addrsort (char **, int) __THROW;
95
96# if PACKETSZ > 65536
97# define MAXPACKET PACKETSZ
98# else
99# define MAXPACKET 65536
100# endif
101
102/* As per RFC 1034 and 1035 a host name cannot exceed 255 octets in length. */
103# ifdef MAXHOSTNAMELEN
104# undef MAXHOSTNAMELEN
105# endif
106# define MAXHOSTNAMELEN 256
107
108typedef union {
109 HEADER hdr;
110 u_char buf[MAXPACKET];
111} querybuf;
112
113typedef union {
114 int32_t al;
115 char ac;
116} align;
117
118# ifndef h_errno
119extern int h_errno;
120# endif
121
122# ifdef DEBUG
123static void
124Dprintf (char *msg, int num)
125{
126 if (_res.options & RES_DEBUG) {
127 int save = errno;
128
129 printf(msg, num);
130 __set_errno (save);
131 }
132}
133# else
134# define Dprintf(msg, num) /*nada*/
135# endif
136
137# define BOUNDED_INCR(x) \
138 do { \
139 cp += x; \
140 if (cp > eom) { \
141 __set_h_errno (NO_RECOVERY); \
142 return (NULL); \
143 } \
144 } while (0)
145
146# define BOUNDS_CHECK(ptr, count) \
147 do { \
148 if ((ptr) + (count) > eom) { \
149 __set_h_errno (NO_RECOVERY); \
150 return (NULL); \
151 } \
152 } while (0)
153
154
155static struct hostent *
156getanswer (const querybuf *answer, int anslen, const char *qname, int qtype)
157{
158 const HEADER *hp;
159 const u_char *cp;
160 int n;
161 const u_char *eom, *erdata;
162 char *bp, **ap, **hap;
163 int type, class, buflen, ancount, qdcount;
164 int haveanswer, had_error;
165 int toobig = 0;
166 char tbuf[MAXDNAME];
167 const char *tname;
168 int (*name_ok) (const char *);
169
170 tname = qname;
171 host.h_name = NULL;
172 eom = answer->buf + anslen;
173 switch (qtype) {
174 case T_A:
175 case T_AAAA:
176 name_ok = res_hnok;
177 break;
178 case T_PTR:
179 name_ok = res_dnok;
180 break;
181 default:
182 return (NULL); /* XXX should be abort(); */
183 }
184 /*
185 * find first satisfactory answer
186 */
187 hp = &answer->hdr;
188 ancount = ntohs(hp->ancount);
189 qdcount = ntohs(hp->qdcount);
190 bp = hostbuf;
191 buflen = sizeof hostbuf;
192 cp = answer->buf;
193 BOUNDED_INCR(HFIXEDSZ);
194 if (qdcount != 1) {
195 __set_h_errno (NO_RECOVERY);
196 return (NULL);
197 }
198 n = dn_expand(answer->buf, eom, cp, bp, buflen);
199 if ((n < 0) || !(*name_ok)(bp)) {
200 __set_h_errno (NO_RECOVERY);
201 return (NULL);
202 }
203 BOUNDED_INCR(n + QFIXEDSZ);
204 if (qtype == T_A || qtype == T_AAAA) {
205 /* res_send() has already verified that the query name is the
206 * same as the one we sent; this just gets the expanded name
207 * (i.e., with the succeeding search-domain tacked on).
208 */
209 n = strlen(bp) + 1; /* for the \0 */
210 if (n >= MAXHOSTNAMELEN) {
211 __set_h_errno (NO_RECOVERY);
212 return (NULL);
213 }
214 host.h_name = bp;
215 bp += n;
216 buflen -= n;
217 /* The qname can be abbreviated, but h_name is now absolute. */
218 qname = host.h_name;
219 }
220 ap = host_aliases;
221 *ap = NULL;
222 host.h_aliases = host_aliases;
223 hap = h_addr_ptrs;
224 *hap = NULL;
225 host.h_addr_list = h_addr_ptrs;
226 haveanswer = 0;
227 had_error = 0;
228 while (ancount-- > 0 && cp < eom && !had_error) {
229 n = dn_expand(answer->buf, eom, cp, bp, buflen);
230 if ((n < 0) || !(*name_ok)(bp)) {
231 had_error++;
232 continue;
233 }
234 cp += n; /* name */
235 BOUNDS_CHECK(cp, 3 * INT16SZ + INT32SZ);
236 type = ns_get16(cp);
237 cp += INT16SZ; /* type */
238 class = ns_get16(cp);
239 cp += INT16SZ + INT32SZ; /* class, TTL */
240 n = ns_get16(cp);
241 cp += INT16SZ; /* len */
242 BOUNDS_CHECK(cp, n);
243 erdata = cp + n;
244 if (class != C_IN) {
245 /* XXX - debug? syslog? */
246 cp += n;
247 continue; /* XXX - had_error++ ? */
248 }
249 if ((qtype == T_A || qtype == T_AAAA) && type == T_CNAME) {
250 if (ap >= &host_aliases[MAXALIASES-1])
251 continue;
252 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
253 if ((n < 0) || !(*name_ok)(tbuf)) {
254 had_error++;
255 continue;
256 }
257 cp += n;
258 if (cp != erdata) {
259 __set_h_errno (NO_RECOVERY);
260 return (NULL);
261 }
262 /* Store alias. */
263 *ap++ = bp;
264 n = strlen(bp) + 1; /* for the \0 */
265 if (n >= MAXHOSTNAMELEN) {
266 had_error++;
267 continue;
268 }
269 bp += n;
270 buflen -= n;
271 /* Get canonical name. */
272 n = strlen(tbuf) + 1; /* for the \0 */
273 if (n > buflen || n >= MAXHOSTNAMELEN) {
274 had_error++;
275 continue;
276 }
277 strcpy(bp, tbuf);
278 host.h_name = bp;
279 bp += n;
280 buflen -= n;
281 continue;
282 }
283 if (qtype == T_PTR && type == T_CNAME) {
284 n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf);
285 if (n < 0 || !res_dnok(tbuf)) {
286 had_error++;
287 continue;
288 }
289 cp += n;
290 if (cp != erdata) {
291 __set_h_errno (NO_RECOVERY);
292 return (NULL);
293 }
294 /* Get canonical name. */
295 n = strlen(tbuf) + 1; /* for the \0 */
296 if (n > buflen || n >= MAXHOSTNAMELEN) {
297 had_error++;
298 continue;
299 }
300 strcpy(bp, tbuf);
301 tname = bp;
302 bp += n;
303 buflen -= n;
304 continue;
305 }
306 if (type != qtype) {
307 /* Log a low priority message if we get an unexpected
308 * record, but skip it if we are using DNSSEC since it
309 * uses many different types in responses that do not
310 * match QTYPE.
311 */
312 cp += n;
313 continue; /* XXX - had_error++ ? */
314 }
315 switch (type) {
316 case T_PTR:
317 if (strcasecmp(tname, bp) != 0) {
318 cp += n;
319 continue; /* XXX - had_error++ ? */
320 }
321 n = dn_expand(answer->buf, eom, cp, bp, buflen);
322 if ((n < 0) || !res_hnok(bp)) {
323 had_error++;
324 break;
325 }
326 cp += n;
327 if (cp != erdata) {
328 __set_h_errno (NO_RECOVERY);
329 return (NULL);
330 }
331 if (!haveanswer)
332 host.h_name = bp;
333 else if (ap < &host_aliases[MAXALIASES-1])
334 *ap++ = bp;
335 else
336 n = -1;
337 if (n != -1) {
338 n = strlen(bp) + 1; /* for the \0 */
339 if (n >= MAXHOSTNAMELEN) {
340 had_error++;
341 break;
342 }
343 bp += n;
344 buflen -= n;
345 }
346 break;
347 case T_A:
348 case T_AAAA:
349 if (strcasecmp(host.h_name, bp) != 0) {
350 cp += n;
351 continue; /* XXX - had_error++ ? */
352 }
353 if (n != host.h_length) {
354 cp += n;
355 continue;
356 }
357 if (!haveanswer) {
358 int nn;
359
360 host.h_name = bp;
361 nn = strlen(bp) + 1; /* for the \0 */
362 bp += nn;
363 buflen -= nn;
364 }
365
366 /* XXX: when incrementing bp, we have to decrement
367 * buflen by the same amount --okir */
368 buflen -= sizeof(align) - ((u_long)bp % sizeof(align));
369
370 bp += sizeof(align) - ((u_long)bp % sizeof(align));
371
372 if (bp + n >= &hostbuf[sizeof hostbuf]) {
373 Dprintf("size (%d) too big\n", n);
374 had_error++;
375 continue;
376 }
377 if (hap >= &h_addr_ptrs[MAXADDRS-1]) {
378 if (!toobig++) {
379 Dprintf("Too many addresses (%d)\n",
380 MAXADDRS);
381 }
382 cp += n;
383 continue;
384 }
385 memmove(*hap++ = bp, cp, n);
386 bp += n;
387 buflen -= n;
388 cp += n;
389 if (cp != erdata) {
390 __set_h_errno (NO_RECOVERY);
391 return (NULL);
392 }
393 break;
394 default:
395 abort();
396 }
397 if (!had_error)
398 haveanswer++;
399 }
400 if (haveanswer) {
401 *ap = NULL;
402 *hap = NULL;
403 /*
404 * Note: we sort even if host can take only one address
405 * in its return structures - should give it the "best"
406 * address in that case, not some random one
407 */
408 if (_res.nsort && haveanswer > 1 && qtype == T_A)
409 addrsort(h_addr_ptrs, haveanswer);
410 if (!host.h_name) {
411 n = strlen(qname) + 1; /* for the \0 */
412 if (n > buflen || n >= MAXHOSTNAMELEN)
413 goto no_recovery;
414 strcpy(bp, qname);
415 host.h_name = bp;
416 bp += n;
417 buflen -= n;
418 }
419 if (res_use_inet6 ())
420 map_v4v6_hostent(&host, &bp, &buflen);
421 __set_h_errno (NETDB_SUCCESS);
422 return (&host);
423 }
424 no_recovery:
425 __set_h_errno (NO_RECOVERY);
426 return (NULL);
427}
428
429extern struct hostent *res_gethostbyname2(const char *name, int af);
430libresolv_hidden_proto (res_gethostbyname2)
431
432struct hostent *
433res_gethostbyname (const char *name)
434{
435 struct resolv_context *ctx = __resolv_context_get ();
436 if (ctx == NULL)
437 {
438 __set_h_errno (NETDB_INTERNAL);
439 return NULL;
440 }
441
442 if (res_use_inet6 ())
443 {
444 struct hostent *hp = res_gethostbyname2_context (ctx, name, AF_INET6);
445 if (hp != NULL)
446 {
447 __resolv_context_put (ctx);
448 return hp;
449 }
450 }
451 struct hostent *hp = res_gethostbyname2_context (ctx, name, AF_INET);
452 __resolv_context_put (ctx);
453 return hp;
454}
455compat_symbol (libresolv, res_gethostbyname, res_gethostbyname, GLIBC_2_0);
456
457static struct hostent *
458res_gethostbyname2_context (struct resolv_context *ctx,
459 const char *name, int af)
460{
461 union
462 {
463 querybuf *buf;
464 u_char *ptr;
465 } buf;
466 querybuf *origbuf;
467 const char *cp;
468 char *bp;
469 int n, size, type, len;
470 struct hostent *ret;
471
472 switch (af) {
473 case AF_INET:
474 size = INADDRSZ;
475 type = T_A;
476 break;
477 case AF_INET6:
478 size = IN6ADDRSZ;
479 type = T_AAAA;
480 break;
481 default:
482 __set_h_errno (NETDB_INTERNAL);
483 __set_errno (EAFNOSUPPORT);
484 return (NULL);
485 }
486
487 host.h_addrtype = af;
488 host.h_length = size;
489
490 /*
491 * if there aren't any dots, it could be a user-level alias.
492 * this is also done in res_query() since we are not the only
493 * function that looks up host names.
494 */
495 char abuf[MAXDNAME];
496 if (strchr (name, '.') != NULL
497 && (cp = __res_context_hostalias (ctx, name, abuf, sizeof (abuf))))
498 name = cp;
499
500 /*
501 * disallow names consisting only of digits/dots, unless
502 * they end in a dot.
503 */
504 if (isdigit(name[0]))
505 for (cp = name;; ++cp) {
506 if (!*cp) {
507 if (*--cp == '.')
508 break;
509 /*
510 * All-numeric, no dot at the end.
511 * Fake up a hostent as if we'd actually
512 * done a lookup.
513 */
514 if (inet_pton(af, name, host_addr) <= 0) {
515 __set_h_errno (HOST_NOT_FOUND);
516 return (NULL);
517 }
518 strncpy(hostbuf, name, MAXDNAME);
519 hostbuf[MAXDNAME] = '\0';
520 bp = hostbuf + MAXDNAME;
521 len = sizeof hostbuf - MAXDNAME;
522 host.h_name = hostbuf;
523 host.h_aliases = host_aliases;
524 host_aliases[0] = NULL;
525 h_addr_ptrs[0] = (char *)host_addr;
526 h_addr_ptrs[1] = NULL;
527 host.h_addr_list = h_addr_ptrs;
528 if (res_use_inet6 ())
529 map_v4v6_hostent(&host, &bp, &len);
530 __set_h_errno (NETDB_SUCCESS);
531 return (&host);
532 }
533 if (!isdigit(*cp) && *cp != '.')
534 break;
535 }
536 if ((isxdigit(name[0]) && strchr(name, ':') != NULL) ||
537 name[0] == ':')
538 for (cp = name;; ++cp) {
539 if (!*cp) {
540 if (*--cp == '.')
541 break;
542 /*
543 * All-IPv6-legal, no dot at the end.
544 * Fake up a hostent as if we'd actually
545 * done a lookup.
546 */
547 if (inet_pton(af, name, host_addr) <= 0) {
548 __set_h_errno (HOST_NOT_FOUND);
549 return (NULL);
550 }
551 strncpy(hostbuf, name, MAXDNAME);
552 hostbuf[MAXDNAME] = '\0';
553 bp = hostbuf + MAXDNAME;
554 len = sizeof hostbuf - MAXDNAME;
555 host.h_name = hostbuf;
556 host.h_aliases = host_aliases;
557 host_aliases[0] = NULL;
558 h_addr_ptrs[0] = (char *)host_addr;
559 h_addr_ptrs[1] = NULL;
560 host.h_addr_list = h_addr_ptrs;
561 __set_h_errno (NETDB_SUCCESS);
562 return (&host);
563 }
564 if (!isxdigit(*cp) && *cp != ':' && *cp != '.')
565 break;
566 }
567
568 buf.buf = origbuf = (querybuf *) alloca (1024);
569
570 if ((n = __res_context_search
571 (ctx, name, C_IN, type, buf.buf->buf, 1024,
572 &buf.ptr, NULL, NULL, NULL, NULL)) < 0) {
573 if (buf.buf != origbuf)
574 free (buf.buf);
575 Dprintf("res_nsearch failed (%d)\n", n);
576 if (errno == ECONNREFUSED)
577 return (_gethtbyname2(name, af));
578 return (NULL);
579 }
580 ret = getanswer(buf.buf, n, name, type);
581 if (buf.buf != origbuf)
582 free (buf.buf);
583 return ret;
584}
585
586struct hostent *
587res_gethostbyname2 (const char *name, int af)
588{
589 struct resolv_context *ctx = __resolv_context_get ();
590 if (ctx == NULL)
591 {
592 __set_h_errno (NETDB_INTERNAL);
593 return NULL;
594 }
595 struct hostent *hp = res_gethostbyname2_context (ctx, name, AF_INET);
596 __resolv_context_put (ctx);
597 return hp;
598}
599libresolv_hidden_def (res_gethostbyname2)
600compat_symbol (libresolv, res_gethostbyname2, res_gethostbyname2, GLIBC_2_0);
601
602static struct hostent *
603res_gethostbyaddr_context (struct resolv_context *ctx,
604 const void *addr, socklen_t len, int af)
605{
606 const u_char *uaddr = (const u_char *)addr;
607 static const u_char mapped[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0xff,0xff };
608 static const u_char tunnelled[] = { 0,0, 0,0, 0,0, 0,0, 0,0, 0,0 };
609 int n;
610 socklen_t size;
611 union
612 {
613 querybuf *buf;
614 u_char *ptr;
615 } buf;
616 querybuf *orig_buf;
617 struct hostent *hp;
618 char qbuf[MAXDNAME+1], *qp = NULL;
619
620 if (af == AF_INET6 && len == IN6ADDRSZ &&
621 (!memcmp(uaddr, mapped, sizeof mapped) ||
622 !memcmp(uaddr, tunnelled, sizeof tunnelled))) {
623 /* Unmap. */
624 addr += sizeof mapped;
625 uaddr += sizeof mapped;
626 af = AF_INET;
627 len = INADDRSZ;
628 }
629 switch (af) {
630 case AF_INET:
631 size = INADDRSZ;
632 break;
633 case AF_INET6:
634 size = IN6ADDRSZ;
635 break;
636 default:
637 __set_errno (EAFNOSUPPORT);
638 __set_h_errno (NETDB_INTERNAL);
639 return (NULL);
640 }
641 if (size != len) {
642 __set_errno (EINVAL);
643 __set_h_errno (NETDB_INTERNAL);
644 return (NULL);
645 }
646 switch (af) {
647 case AF_INET:
648 (void) sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa",
649 (uaddr[3] & 0xff),
650 (uaddr[2] & 0xff),
651 (uaddr[1] & 0xff),
652 (uaddr[0] & 0xff));
653 break;
654 case AF_INET6:
655 qp = qbuf;
656 for (n = IN6ADDRSZ - 1; n >= 0; n--) {
657 qp += sprintf(qp, "%x.%x.",
658 uaddr[n] & 0xf,
659 (uaddr[n] >> 4) & 0xf);
660 }
661 strcpy(qp, "ip6.arpa");
662 break;
663 default:
664 abort();
665 }
666
667 buf.buf = orig_buf = (querybuf *) alloca (1024);
668
669 n = __res_context_query (ctx, qbuf, C_IN, T_PTR, buf.buf->buf, 1024,
670 &buf.ptr, NULL, NULL, NULL, NULL);
671 if (n < 0) {
672 if (buf.buf != orig_buf)
673 free (buf.buf);
674 Dprintf("res_nquery failed (%d)\n", n);
675 if (errno == ECONNREFUSED)
676 return (_gethtbyaddr(addr, len, af));
677 return (NULL);
678 }
679 hp = getanswer(buf.buf, n, qbuf, T_PTR);
680 if (buf.buf != orig_buf)
681 free (buf.buf);
682 if (!hp)
683 return (NULL); /* h_errno was set by getanswer() */
684 hp->h_addrtype = af;
685 hp->h_length = len;
686 memmove(host_addr, addr, len);
687 h_addr_ptrs[0] = (char *)host_addr;
688 h_addr_ptrs[1] = NULL;
689 if (af == AF_INET && res_use_inet6 ()) {
690 map_v4v6_address((char*)host_addr, (char*)host_addr);
691 hp->h_addrtype = AF_INET6;
692 hp->h_length = IN6ADDRSZ;
693 }
694 __set_h_errno (NETDB_SUCCESS);
695 return (hp);
696}
697
698struct hostent *
699res_gethostbyaddr (const void *addr, socklen_t len, int af)
700{
701 struct resolv_context *ctx = __resolv_context_get ();
702 if (ctx == NULL)
703 {
704 __set_h_errno (NETDB_INTERNAL);
705 return NULL;
706 }
707 struct hostent *hp = res_gethostbyaddr_context (ctx, addr, len, af);
708 __resolv_context_put (ctx);
709 return hp;
710}
711compat_symbol (libresolv, res_gethostbyaddr, res_gethostbyaddr, GLIBC_2_0);
712
713void
714_sethtent (int f)
715{
716 if (!hostf)
717 hostf = fopen(_PATH_HOSTS, "rce" );
718 else
719 rewind(hostf);
720 stayopen = f;
721}
722libresolv_hidden_def (_sethtent)
723compat_symbol (libresolv, _sethtent, _sethtent, GLIBC_2_0);
724
725static void
726_endhtent (void)
727{
728 if (hostf && !stayopen) {
729 (void) fclose(hostf);
730 hostf = NULL;
731 }
732}
733
734struct hostent *
735_gethtent (void)
736{
737 char *p;
738 char *cp, **q;
739 int af, len;
740
741 if (!hostf && !(hostf = fopen(_PATH_HOSTS, "rce" ))) {
742 __set_h_errno (NETDB_INTERNAL);
743 return (NULL);
744 }
745 again:
746 if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) {
747 __set_h_errno (HOST_NOT_FOUND);
748 return (NULL);
749 }
750 if (*p == '#')
751 goto again;
752 if (!(cp = strpbrk(p, "#\n")))
753 goto again;
754 *cp = '\0';
755 if (!(cp = strpbrk(p, " \t")))
756 goto again;
757 *cp++ = '\0';
758 if (inet_pton(AF_INET6, p, host_addr) > 0) {
759 af = AF_INET6;
760 len = IN6ADDRSZ;
761 } else if (inet_pton(AF_INET, p, host_addr) > 0) {
762 if (res_use_inet6 ()) {
763 map_v4v6_address((char*)host_addr, (char*)host_addr);
764 af = AF_INET6;
765 len = IN6ADDRSZ;
766 } else {
767 af = AF_INET;
768 len = INADDRSZ;
769 }
770 } else {
771 goto again;
772 }
773 h_addr_ptrs[0] = (char *)host_addr;
774 h_addr_ptrs[1] = NULL;
775 host.h_addr_list = h_addr_ptrs;
776 host.h_length = len;
777 host.h_addrtype = af;
778 while (*cp == ' ' || *cp == '\t')
779 cp++;
780 host.h_name = cp;
781 q = host.h_aliases = host_aliases;
782 if ((cp = strpbrk(cp, " \t")))
783 *cp++ = '\0';
784 while (cp && *cp) {
785 if (*cp == ' ' || *cp == '\t') {
786 cp++;
787 continue;
788 }
789 if (q < &host_aliases[MAXALIASES - 1])
790 *q++ = cp;
791 if ((cp = strpbrk(cp, " \t")))
792 *cp++ = '\0';
793 }
794 *q = NULL;
795 __set_h_errno (NETDB_SUCCESS);
796 return (&host);
797}
798libresolv_hidden_def (_gethtent)
799compat_symbol (libresolv, _gethtent, _gethtent, GLIBC_2_0);
800
801struct hostent *
802_gethtbyname (const char *name)
803{
804 struct hostent *hp;
805
806 if (res_use_inet6 ()) {
807 hp = _gethtbyname2(name, AF_INET6);
808 if (hp)
809 return (hp);
810 }
811 return (_gethtbyname2(name, AF_INET));
812}
813compat_symbol (libresolv, _gethtbyname, _gethtbyname, GLIBC_2_0);
814
815struct hostent *
816_gethtbyname2 (const char *name, int af)
817{
818 struct hostent *p;
819 char **cp;
820
821 _sethtent(0);
822 while ((p = _gethtent())) {
823 if (p->h_addrtype != af)
824 continue;
825 if (strcasecmp(p->h_name, name) == 0)
826 break;
827 for (cp = p->h_aliases; *cp != 0; cp++)
828 if (strcasecmp(*cp, name) == 0)
829 goto found;
830 }
831 found:
832 _endhtent();
833 return (p);
834}
835libresolv_hidden_def (_gethtbyname2)
836compat_symbol (libresolv, _gethtbyname2, _gethtbyname2, GLIBC_2_0);
837
838struct hostent *
839_gethtbyaddr (const char *addr, size_t len, int af)
840{
841 struct hostent *p;
842
843 _sethtent(0);
844 while ((p = _gethtent()))
845 if (p->h_addrtype == af && !memcmp(p->h_addr, addr, len))
846 break;
847 _endhtent();
848 return (p);
849}
850libresolv_hidden_def (_gethtbyaddr)
851compat_symbol (libresolv, _gethtbyaddr, _gethtbyaddr, GLIBC_2_0);
852
853static void
854map_v4v6_address (const char *src, char *dst)
855{
856 u_char *p = (u_char *)dst;
857 char tmp[INADDRSZ];
858 int i;
859
860 /* Stash a temporary copy so our caller can update in place. */
861 memcpy(tmp, src, INADDRSZ);
862 /* Mark this ipv6 addr as a mapped ipv4. */
863 for (i = 0; i < 10; i++)
864 *p++ = 0x00;
865 *p++ = 0xff;
866 *p++ = 0xff;
867 /* Retrieve the saved copy and we're done. */
868 memcpy((void*)p, tmp, INADDRSZ);
869}
870
871static void
872map_v4v6_hostent (struct hostent *hp, char **bpp, int *lenp)
873{
874 char **ap;
875
876 if (hp->h_addrtype != AF_INET || hp->h_length != INADDRSZ)
877 return;
878 hp->h_addrtype = AF_INET6;
879 hp->h_length = IN6ADDRSZ;
880 for (ap = hp->h_addr_list; *ap; ap++) {
881 int i = sizeof(align) - ((u_long)*bpp % sizeof(align));
882
883 if (*lenp < (i + IN6ADDRSZ)) {
884 /* Out of memory. Truncate address list here. XXX */
885 *ap = NULL;
886 return;
887 }
888 *bpp += i;
889 *lenp -= i;
890 map_v4v6_address(*ap, *bpp);
891 *ap = *bpp;
892 *bpp += IN6ADDRSZ;
893 *lenp -= IN6ADDRSZ;
894 }
895}
896
897extern void
898addrsort (char **ap, int num)
899{
900 int i, j;
901 char **p;
902 short aval[MAXADDRS];
903 int needsort = 0;
904
905 p = ap;
906 for (i = 0; i < num; i++, p++) {
907 for (j = 0 ; (unsigned)j < _res.nsort; j++)
908 if (_res.sort_list[j].addr.s_addr ==
909 (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask))
910 break;
911 aval[i] = j;
912 if (needsort == 0 && i > 0 && j < aval[i-1])
913 needsort = i;
914 }
915 if (!needsort)
916 return;
917
918 while (needsort < num) {
919 for (j = needsort - 1; j >= 0; j--) {
920 if (aval[j] > aval[j+1]) {
921 char *hp;
922
923 i = aval[j];
924 aval[j] = aval[j+1];
925 aval[j+1] = i;
926
927 hp = ap[j];
928 ap[j] = ap[j+1];
929 ap[j+1] = hp;
930
931 } else
932 break;
933 }
934 needsort++;
935 }
936}
937
938#endif /* SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_25) */
939