source: trunk/src/sh_static.c@ 538

Last change on this file since 538 was 533, checked in by katerina, 7 years ago

Fix for ticket #425 (bug in static dns resolver).
File size: 49.7 KB
Line 
1/* Copyright (C) 2003 Manuel Novoa III
2 *
3 * This library is free software; you can redistribute it and/or
4 * modify it under the terms of the GNU Library General Public
5 * License as published by the Free Software Foundation; either
6 * version 2 of the License, or (at your option) any later version.
7 *
8 * This library is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * Library General Public License for more details.
12 *
13 * You should have received a copy of the GNU Library General Public
14 * License along with this library; if not, write to the Free
15 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
16 */
17
18/* Nov 6, 2003 Initial version.
19 *
20 * NOTE: This implementation is quite strict about requiring all
21 * field seperators. It also does not allow leading whitespace
22 * except when processing the numeric fields. glibc is more
23 * lenient. See the various glibc difference comments below.
24 *
25 * TODO:
26 * Move to dynamic allocation of (currently staticly allocated)
27 * buffers; especially for the group-related functions since
28 * large group member lists will cause error returns.
29 *
30 */
31
32/* Jul 20, 2004 Adapted for samhain. Rainer Wichmann.
33 *
34 * Stripped all unneeded code.
35 */
36
37#include "config_xor.h"
38
39#if defined(SH_COMPILE_STATIC) && defined(__linux__)
40
41#define _GNU_SOURCE
42#include <features.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <stdint.h>
46#include <string.h>
47#include <stddef.h>
48#include <errno.h>
49#include <assert.h>
50#include <ctype.h>
51#include <pwd.h>
52#include <grp.h>
53
54#include "sh_pthread.h"
55
56extern int sl_close_fd (const char * file, int line, int fd);
57extern int sl_fclose (const char * file, int line, FILE * fp);
58
59
60#ifndef _PATH_PASSWD
61#define _PATH_PASSWD "/etc/passwd"
62#endif
63#ifndef _PATH_GROUP
64#define _PATH_GROUP "/etc/group"
65#endif
66
67#undef FIL__
68#define FIL__ _("sh_static.c")
69
70extern int sl_strlcpy(char * dst, /*@null@*/const char * src, size_t siz);
71extern int sl_strlcat(char * dst, /*@null@*/const char * src, size_t siz);
72
73
74/**********************************************************************/
75/* Sizes for staticly allocated buffers. */
76
77#define PWD_BUFFER_SIZE 256
78#define GRP_BUFFER_SIZE 3584
79#define GRP_BUFFER_SIZE_MALLOC 32768
80
81/**********************************************************************/
82/* Prototypes for internal functions. */
83
84static int __parsepwent(void *pw, char *line);
85static int __parsegrent(void *gr, char *line);
86
87static int __pgsreader(int (*__parserfunc)(void *d, char *line), void *data,
88 char *__restrict line_buff,
89 size_t buflen, FILE *f);
90
91#undef GETXXKEY_R_FUNC
92#undef GETXXKEY_R_PARSER
93#undef GETXXKEY_R_ENTTYPE
94#undef GETXXKEY_R_TEST
95#undef DO_GETXXKEY_R_KEYTYPE
96#undef DO_GETXXKEY_R_PATHNAME
97#define GETXXKEY_R_FUNC sh_getpwnam_r
98#define GETXXKEY_R_PARSER __parsepwent
99#define GETXXKEY_R_ENTTYPE struct passwd
100#define GETXXKEY_R_TEST(ENT) (!strcmp((ENT)->pw_name, key))
101#define DO_GETXXKEY_R_KEYTYPE const char *__restrict
102#define DO_GETXXKEY_R_PATHNAME _PATH_PASSWD
103
104int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
105 GETXXKEY_R_ENTTYPE *__restrict resultbuf,
106 char *__restrict buffer, size_t buflen,
107 GETXXKEY_R_ENTTYPE **__restrict result)
108{
109 FILE *stream;
110 int rv;
111
112 *result = NULL;
113
114 if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
115 rv = errno;
116 } else {
117 /* __STDIO_SET_USER_LOCKING(stream); */
118 do {
119 if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
120 buffer, buflen, stream))
121 ) {
122 if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
123 *result = resultbuf;
124 break;
125 }
126 } else {
127 if (rv == ENOENT) { /* end-of-file encountered. */
128 rv = 0;
129 }
130 break;
131 }
132 } while (1);
133 sl_fclose(FIL__, __LINE__, stream);
134 }
135
136 return rv;
137}
138
139#undef GETXXKEY_R_FUNC
140#undef GETXXKEY_R_PARSER
141#undef GETXXKEY_R_ENTTYPE
142#undef GETXXKEY_R_TEST
143#undef DO_GETXXKEY_R_KEYTYPE
144#undef DO_GETXXKEY_R_PATHNAME
145#define GETXXKEY_R_FUNC sh_getgrnam_r
146#define GETXXKEY_R_PARSER __parsegrent
147#define GETXXKEY_R_ENTTYPE struct group
148#define GETXXKEY_R_TEST(ENT) (!strcmp((ENT)->gr_name, key))
149#define DO_GETXXKEY_R_KEYTYPE const char *__restrict
150#define DO_GETXXKEY_R_PATHNAME _PATH_GROUP
151
152int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
153 GETXXKEY_R_ENTTYPE *__restrict resultbuf,
154 char *__restrict buffer, size_t buflen,
155 GETXXKEY_R_ENTTYPE **__restrict result)
156{
157 FILE *stream;
158 int rv;
159
160 *result = NULL;
161
162 if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
163 rv = errno;
164 } else {
165 /* __STDIO_SET_USER_LOCKING(stream); */
166 do {
167 if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
168 buffer, buflen, stream))
169 ) {
170 if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
171 *result = resultbuf;
172 break;
173 }
174 } else {
175 if (rv == ENOENT) { /* end-of-file encountered. */
176 rv = 0;
177 }
178 break;
179 }
180 } while (1);
181 sl_fclose(FIL__, __LINE__, stream);
182 }
183
184 return rv;
185}
186
187#undef GETXXKEY_R_FUNC
188#undef GETXXKEY_R_PARSER
189#undef GETXXKEY_R_ENTTYPE
190#undef GETXXKEY_R_TEST
191#undef DO_GETXXKEY_R_KEYTYPE
192#undef DO_GETXXKEY_R_PATHNAME
193#define GETXXKEY_R_FUNC sh_getpwuid_r
194#define GETXXKEY_R_PARSER __parsepwent
195#define GETXXKEY_R_ENTTYPE struct passwd
196#define GETXXKEY_R_TEST(ENT) ((ENT)->pw_uid == key)
197#define DO_GETXXKEY_R_KEYTYPE uid_t
198#define DO_GETXXKEY_R_PATHNAME _PATH_PASSWD
199
200int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
201 GETXXKEY_R_ENTTYPE *__restrict resultbuf,
202 char *__restrict buffer, size_t buflen,
203 GETXXKEY_R_ENTTYPE **__restrict result)
204{
205 FILE *stream;
206 int rv;
207
208 *result = NULL;
209
210 if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
211 rv = errno;
212 } else {
213 /* __STDIO_SET_USER_LOCKING(stream); */
214 do {
215 if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
216 buffer, buflen, stream))
217 ) {
218 if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
219 *result = resultbuf;
220 break;
221 }
222 } else {
223 if (rv == ENOENT) { /* end-of-file encountered. */
224 rv = 0;
225 }
226 break;
227 }
228 } while (1);
229 sl_fclose(FIL__, __LINE__, stream);
230 }
231
232 return rv;
233}
234
235#undef GETXXKEY_R_FUNC
236#undef GETXXKEY_R_PARSER
237#undef GETXXKEY_R_ENTTYPE
238#undef GETXXKEY_R_TEST
239#undef DO_GETXXKEY_R_KEYTYPE
240#undef DO_GETXXKEY_R_PATHNAME
241#define GETXXKEY_R_FUNC sh_getgrgid_r
242#define GETXXKEY_R_PARSER __parsegrent
243#define GETXXKEY_R_ENTTYPE struct group
244#define GETXXKEY_R_TEST(ENT) ((ENT)->gr_gid == key)
245#define DO_GETXXKEY_R_KEYTYPE gid_t
246#define DO_GETXXKEY_R_PATHNAME _PATH_GROUP
247
248int GETXXKEY_R_FUNC(DO_GETXXKEY_R_KEYTYPE key,
249 GETXXKEY_R_ENTTYPE *__restrict resultbuf,
250 char *__restrict buffer, size_t buflen,
251 GETXXKEY_R_ENTTYPE **__restrict result)
252{
253 FILE *stream;
254 int rv;
255
256 *result = NULL;
257
258 if (!(stream = fopen(DO_GETXXKEY_R_PATHNAME, "r"))) {
259 rv = errno;
260 } else {
261 /* __STDIO_SET_USER_LOCKING(stream); */
262 do {
263 if (!(rv = __pgsreader(GETXXKEY_R_PARSER, resultbuf,
264 buffer, buflen, stream))
265 ) {
266 if (GETXXKEY_R_TEST(resultbuf)) { /* Found key? */
267 *result = resultbuf;
268 break;
269 }
270 } else {
271 if (rv == ENOENT) { /* end-of-file encountered. */
272 rv = 0;
273 }
274 break;
275 }
276 } while (1);
277 sl_fclose(FIL__, __LINE__, stream);
278 }
279
280 return rv;
281}
282
283struct passwd * sh_getpwuid(uid_t uid)
284{
285 static char buffer[PWD_BUFFER_SIZE];
286 static struct passwd resultbuf;
287 struct passwd *result;
288
289 sh_getpwuid_r(uid, &resultbuf, buffer, sizeof(buffer), &result);
290 return result;
291}
292
293struct passwd * getpwuid(uid_t uid)
294{
295 return sh_getpwuid(uid);
296}
297
298struct group * sh_getgrgid(gid_t gid)
299{
300 static char buffer[GRP_BUFFER_SIZE];
301 static struct group resultbuf;
302 struct group *result;
303
304 sh_getgrgid_r(gid, &resultbuf, buffer, sizeof(buffer), &result);
305 return result;
306}
307
308struct group * getgrgid(gid_t gid)
309{
310 return sh_getgrgid(gid);
311}
312
313struct passwd * sh_getpwnam(const char *name)
314{
315 static char buffer[PWD_BUFFER_SIZE];
316 static struct passwd resultbuf;
317 struct passwd *result;
318
319 sh_getpwnam_r(name, &resultbuf, buffer, sizeof(buffer), &result);
320 return result;
321}
322
323struct group * sh_getgrnam(const char *name)
324{
325 static char buffer[GRP_BUFFER_SIZE];
326 static struct group resultbuf;
327 struct group *result;
328
329 sh_getgrnam_r(name, &resultbuf, buffer, sizeof(buffer), &result);
330 return result;
331}
332
333SH_MUTEX_STATIC(pwf_lock, PTHREAD_MUTEX_INITIALIZER);
334
335
336static FILE *pwf = NULL;
337
338void sh_setpwent(void)
339{
340 SH_MUTEX_LOCK(pwf_lock);
341 if (pwf) {
342 rewind(pwf);
343 }
344 SH_MUTEX_UNLOCK(pwf_lock);
345}
346
347void sh_endpwent(void)
348{
349 SH_MUTEX_LOCK(pwf_lock);
350 if (pwf) {
351 sl_fclose(FIL__, __LINE__, pwf);
352 pwf = NULL;
353 }
354 SH_MUTEX_UNLOCK(pwf_lock);
355}
356
357
358static int sh_getpwent_r(struct passwd *__restrict resultbuf,
359 char *__restrict buffer, size_t buflen,
360 struct passwd **__restrict result)
361{
362 int rv;
363
364 SH_MUTEX_LOCK(pwf_lock);
365
366 *result = NULL; /* In case of error... */
367
368 if (!pwf) {
369 if (!(pwf = fopen(_PATH_PASSWD, "r"))) {
370 rv = errno;
371 goto ERR;
372 }
373 /* __STDIO_SET_USER_LOCKING(pwf); */
374 }
375
376 if (!(rv = __pgsreader(__parsepwent, resultbuf,
377 buffer, buflen, pwf))) {
378 *result = resultbuf;
379 }
380
381 ERR:
382 ; /* 'label at end of compound statement' */
383 SH_MUTEX_UNLOCK(pwf_lock);
384
385 return rv;
386}
387
388SH_MUTEX_STATIC(grf_lock, PTHREAD_MUTEX_INITIALIZER);
389
390static FILE *grf = NULL;
391
392void sh_setgrent(void)
393{
394 SH_MUTEX_LOCK(grf_lock);
395 if (grf) {
396 rewind(grf);
397 }
398 SH_MUTEX_UNLOCK(grf_lock);
399}
400
401void sh_endgrent(void)
402{
403 SH_MUTEX_LOCK(grf_lock);
404 if (grf) {
405 sl_fclose(FIL__, __LINE__, grf);
406 grf = NULL;
407 }
408 SH_MUTEX_UNLOCK(grf_lock);
409}
410
411static int sh_getgrent_r(struct group *__restrict resultbuf,
412 char *__restrict buffer, size_t buflen,
413 struct group **__restrict result)
414{
415 int rv;
416
417 SH_MUTEX_LOCK(grf_lock);
418
419 *result = NULL; /* In case of error... */
420
421 if (!grf) {
422 if (!(grf = fopen(_PATH_GROUP, "r"))) {
423 rv = errno;
424 goto ERR;
425 }
426 /* __STDIO_SET_USER_LOCKING(grf); */
427 }
428
429 if (!(rv = __pgsreader(__parsegrent, resultbuf,
430 buffer, buflen, grf))) {
431 *result = resultbuf;
432 }
433
434 ERR:
435 ; /* 'label at end of compound statement' */
436 SH_MUTEX_UNLOCK(grf_lock);
437
438 return rv;
439}
440
441
442struct passwd * sh_getpwent(void)
443{
444 static char line_buff[PWD_BUFFER_SIZE];
445 static struct passwd pwd;
446 struct passwd *result;
447
448 sh_getpwent_r(&pwd, line_buff, sizeof(line_buff), &result);
449 return result;
450}
451
452
453struct group * sh_getgrent(void)
454{
455 static char line_buff[GRP_BUFFER_SIZE];
456 static struct group gr;
457 struct group *result;
458
459 sh_getgrent_r(&gr, line_buff, sizeof(line_buff), &result);
460 return result;
461}
462
463int sh_initgroups(const char *user, gid_t gid)
464{
465 FILE *grf;
466 gid_t *group_list;
467 int num_groups, rv;
468 char **m;
469 struct group group;
470
471 char * buff = calloc(1,GRP_BUFFER_SIZE_MALLOC);
472
473 rv = -1;
474
475 /* We alloc space for 8 gids at a time. */
476 if (((group_list = calloc(8,sizeof(gid_t *))) != NULL)
477 && ((grf = fopen(_PATH_GROUP, "r")) != NULL)
478 ) {
479
480 /* __STDIO_SET_USER_LOCKING(grf); */
481
482 *group_list = gid;
483 num_groups = 1;
484
485 while (!__pgsreader(__parsegrent, &group, buff, GRP_BUFFER_SIZE_MALLOC, grf)) {
486 assert(group.gr_mem); /* Must have at least a NULL terminator. */
487 if (group.gr_gid != gid) {
488 for (m=group.gr_mem ; *m ; m++) {
489 if (!strcmp(*m, user)) {
490 if (!(num_groups & 7)) {
491 gid_t *tmp = (gid_t *)
492 realloc(group_list,
493 (num_groups+8) * sizeof(gid_t *));
494 if (!tmp) {
495 rv = -1;
496 goto DO_CLOSE;
497 }
498 group_list = tmp;
499 }
500 group_list[num_groups++] = group.gr_gid;
501 break;
502 }
503 }
504 }
505 }
506
507 rv = setgroups(num_groups, group_list);
508 DO_CLOSE:
509 sl_fclose(FIL__, __LINE__, grf);
510 }
511
512 /* group_list will be NULL if initial malloc failed, which may trigger
513 * warnings from various malloc debuggers. */
514 free(group_list);
515 free(buff);
516 return rv;
517}
518
519
520/**********************************************************************/
521/* Internal uClibc functions. */
522/**********************************************************************/
523
524static const unsigned char pw_off[] = {
525 offsetof(struct passwd, pw_name), /* 0 */
526 offsetof(struct passwd, pw_passwd), /* 1 */
527 offsetof(struct passwd, pw_uid), /* 2 - not a char ptr */
528 offsetof(struct passwd, pw_gid), /* 3 - not a char ptr */
529 offsetof(struct passwd, pw_gecos), /* 4 */
530 offsetof(struct passwd, pw_dir), /* 5 */
531 offsetof(struct passwd, pw_shell) /* 6 */
532};
533
534static int __parsepwent(void *data, char *line)
535{
536 char *endptr;
537 char *p;
538 int i;
539
540 i = 0;
541 do {
542 p = ((char *) ((struct passwd *) data)) + pw_off[i];
543
544 if ((i & 6) ^ 2) { /* i!=2 and i!=3 */
545 *((char **) p) = line;
546 if (i==6) {
547 return 0;
548 }
549 /* NOTE: glibc difference - glibc allows omission of
550 * ':' seperators after the gid field if all remaining
551 * entries are empty. We require all separators. */
552 if (!(line = strchr(line, ':'))) {
553 break;
554 }
555 } else {
556 unsigned long t = strtoul(line, &endptr, 10);
557 /* Make sure we had at least one digit, and that the
558 * failing char is the next field seperator ':'. See
559 * glibc difference note above. */
560 /* TODO: Also check for leading whitespace? */
561 if ((endptr == line) || (*endptr != ':')) {
562 break;
563 }
564 line = endptr;
565 if (i & 1) { /* i == 3 -- gid */
566 *((gid_t *) p) = t;
567 } else { /* i == 2 -- uid */
568 *((uid_t *) p) = t;
569 }
570 }
571
572 *line++ = 0;
573 ++i;
574 } while (1);
575
576 return -1;
577}
578
579static const unsigned char gr_off[] = {
580 offsetof(struct group, gr_name), /* 0 */
581 offsetof(struct group, gr_passwd), /* 1 */
582 offsetof(struct group, gr_gid) /* 2 - not a char ptr */
583};
584
585static int __parsegrent(void *data, char *line)
586{
587 char *endptr;
588 char *p;
589 int i;
590 char **members;
591 char *end_of_buf;
592
593 end_of_buf = ((struct group *) data)->gr_name; /* Evil hack! */
594 i = 0;
595 do {
596 p = ((char *) ((struct group *) data)) + gr_off[i];
597
598 if (i < 2) {
599 *((char **) p) = line;
600 if (!(line = strchr(line, ':'))) {
601 break;
602 }
603 *line++ = 0;
604 ++i;
605 } else {
606 *((gid_t *) p) = strtoul(line, &endptr, 10);
607
608 /* NOTE: glibc difference - glibc allows omission of the
609 * trailing colon when there is no member list. We treat
610 * this as an error. */
611
612 /* Make sure we had at least one digit, and that the
613 * failing char is the next field seperator ':'. See
614 * glibc difference note above. */
615 if ((endptr == line) || (*endptr != ':')) {
616 break;
617 }
618
619 i = 1; /* Count terminating NULL ptr. */
620 p = endptr;
621
622 if (p[1]) { /* We have a member list to process. */
623 /* Overwrite the last ':' with a ',' before counting.
624 * This allows us to test for initial ',' and adds
625 * one ',' so that the ',' count equals the member
626 * count. */
627 *p = ',';
628 do {
629 /* NOTE: glibc difference - glibc allows and trims leading
630 * (but not trailing) space. We treat this as an error. */
631 /* NOTE: glibc difference - glibc allows consecutive and
632 * trailing commas, and ignores "empty string" users. We
633 * treat this as an error. */
634 if (*p == ',') {
635 ++i;
636 *p = 0; /* nul-terminate each member string. */
637 if (!*++p || (*p == ',') || isspace(*p)) {
638 goto ERR;
639 }
640 }
641 } while (*++p);
642 }
643
644 /* Now align (p+1), rounding up. */
645 /* Assumes sizeof(char **) is a power of 2. */
646 members = (char **)( (((intptr_t) p) + sizeof(char **))
647 & ~((intptr_t)(sizeof(char **) - 1)) );
648
649 if (((char *)(members + i)) > end_of_buf) { /* No space. */
650 break;
651 }
652
653 ((struct group *) data)->gr_mem = members;
654
655 if (--i) {
656 p = endptr; /* Pointing to char prior to first member. */
657 do {
658 *members++ = ++p;
659 if (!--i) break;
660 while (*++p) {}
661 } while (1);
662 }
663 *members = NULL;
664
665 return 0;
666 }
667 } while (1);
668
669 ERR:
670 return -1;
671}
672
673/* Reads until if EOF, or until if finds a line which fits in the buffer
674 * and for which the parser function succeeds.
675 *
676 * Returns 0 on success and ENOENT for end-of-file (glibc concession).
677 */
678
679static int __pgsreader(int (*__parserfunc)(void *d, char *line), void *data,
680 char *__restrict line_buff, size_t buflen, FILE *f)
681{
682 size_t line_len; /* int -> size_t R.W. */
683 int skip;
684 int rv = ERANGE;
685
686 if (buflen < PWD_BUFFER_SIZE) {
687 errno = rv;
688 } else {
689 /* __STDIO_THREADLOCK(f); */
690
691 skip = 0;
692 do {
693 if (!fgets(line_buff, buflen, f)) {
694 if (feof(f)) {
695 rv = ENOENT;
696 }
697 break;
698 }
699
700 line_len = strlen(line_buff) - 1; /* strlen() must be > 0. */
701 if (line_buff[line_len] == '\n') {
702 line_buff[line_len] = 0;
703 } else if (line_len + 2 == buflen) { /* line too long */
704 rv = ERANGE;
705 break;
706 /*
707 ++skip;
708 continue;
709 */
710 }
711
712 if (skip) {
713 --skip;
714 continue;
715 }
716
717 /* NOTE: glibc difference - glibc strips leading whitespace from
718 * records. We do not allow leading whitespace. */
719
720 /* Skip empty lines, comment lines, and lines with leading
721 * whitespace. */
722 if (*line_buff && (*line_buff != '#') && !isspace(*line_buff)) {
723 if (__parserfunc == __parsegrent) { /* Do evil group hack. */
724 /* The group entry parsing function needs to know where
725 * the end of the buffer is so that it can construct the
726 * group member ptr table. */
727 ((struct group *) data)->gr_name = line_buff + buflen;
728 }
729
730 if (!__parserfunc(data, line_buff)) {
731 rv = 0;
732 break;
733 }
734 }
735 } while (1);
736
737 /* __STDIO_THREADUNLOCK(f); */
738 }
739
740 return rv;
741}
742
743/* resolv.c: DNS Resolver
744 *
745 * Copyright (C) 1998 Kenneth Albanowski <kjahds@kjahds.com>,
746 * The Silver Hammer Group, Ltd.
747 *
748 * This library is free software; you can redistribute it and/or
749 * modify it under the terms of the GNU Library General Public
750 * License as published by the Free Software Foundation; either
751 * version 2 of the License, or (at your option) any later version.
752*/
753
754/*
755 * Portions Copyright (c) 1985, 1993
756 * The Regents of the University of California. All rights reserved.
757 *
758 * Redistribution and use in source and binary forms, with or without
759 * modification, are permitted provided that the following conditions
760 * are met:
761 * 1. Redistributions of source code must retain the above copyright
762 * notice, this list of conditions and the following disclaimer.
763 * 2. Redistributions in binary form must reproduce the above copyright
764 * notice, this list of conditions and the following disclaimer in the
765 * documentation and/or other materials provided with the distribution.
766 * 4. Neither the name of the University nor the names of its contributors
767 * may be used to endorse or promote products derived from this software
768 * without specific prior written permission.
769 *
770 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
771 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
772 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
773 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
774 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
775 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
776 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
777 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
778 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
779 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
780 * SUCH DAMAGE.
781 */
782
783/*
784 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
785 *
786 * Permission to use, copy, modify, and distribute this software for any
787 * purpose with or without fee is hereby granted, provided that the above
788 * copyright notice and this permission notice appear in all copies, and that
789 * the name of Digital Equipment Corporation not be used in advertising or
790 * publicity pertaining to distribution of the document or software without
791 * specific, written prior permission.
792 *
793 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
794 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
795 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
796 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
797 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
798 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
799 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
800 * SOFTWARE.
801 */
802
803/*
804 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
805 *
806 * Permission to use, copy, modify, and distribute this software for any
807 * purpose with or without fee is hereby granted, provided that the above
808 * copyright notice and this permission notice appear in all copies.
809 *
810 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
811 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
812 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
813 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
814 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
815 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
816 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
817 * SOFTWARE.
818 */
819
820/*
821 *
822 * 5-Oct-2000 W. Greathouse wgreathouse@smva.com
823 * Fix memory leak and memory corruption.
824 * -- Every name resolution resulted in
825 * a new parse of resolv.conf and new
826 * copy of nameservers allocated by
827 * strdup.
828 * -- Every name resolution resulted in
829 * a new read of resolv.conf without
830 * resetting index from prior read...
831 * resulting in exceeding array bounds.
832 *
833 * Limit nameservers read from resolv.conf
834 *
835 * Add "search" domains from resolv.conf
836 *
837 * Some systems will return a security
838 * signature along with query answer for
839 * dynamic DNS entries.
840 * -- skip/ignore this answer
841 *
842 * Include arpa/nameser.h for defines.
843 *
844 * General cleanup
845 *
846 * 20-Jun-2001 Michal Moskal <malekith@pld.org.pl>
847 * partial IPv6 support (i.e. gethostbyname2() and resolve_address2()
848 * functions added), IPv6 nameservers are also supported.
849 *
850 * 6-Oct-2001 Jari Korva <jari.korva@iki.fi>
851 * more IPv6 support (IPv6 support for gethostbyaddr();
852 * address family parameter and improved IPv6 support for get_hosts_byname
853 * and read_etc_hosts; getnameinfo() port from glibc; defined
854 * defined ip6addr_any and in6addr_loopback)
855 *
856 * 2-Feb-2002 Erik Andersen <andersee@debian.org>
857 * Added gethostent(), sethostent(), and endhostent()
858 *
859 * 17-Aug-2002 Manuel Novoa III <mjn3@codepoet.org>
860 * Fixed __read_etc_hosts_r to return alias list, and modified buffer
861 * allocation accordingly. See MAX_ALIASES and ALIAS_DIM below.
862 * This fixes the segfault in the Python 2.2.1 socket test.
863 *
864 * 04-Jan-2003 Jay Kulpinski <jskulpin@berkshire.rr.com>
865 * Fixed __decode_dotted to count the terminating null character
866 * in a host name.
867 *
868 * 02-Oct-2003 Tony J. White <tjw@tjw.org>
869 * Lifted dn_expand() and dependent ns_name_uncompress(), ns_name_unpack(),
870 * and ns_name_ntop() from glibc 2.3.2 for compatibility with ipsec-tools
871 * and openldap.
872 *
873 */
874
875#include <sys/socket.h>
876#include <netinet/in.h>
877#include <arpa/inet.h>
878
879/* sl_close_fd(FIL__, __LINE__, )
880 */
881#include <unistd.h>
882
883/* 'struct hostent'
884 */
885#include <netdb.h>
886
887/* constanst like HFIXEDSZ
888 */
889#include <arpa/nameser.h>
890
891SH_MUTEX_STATIC(resolv_lock, PTHREAD_MUTEX_INITIALIZER);
892
893#define __UCLIBC_HAS_IPV6__
894#define MAX_RECURSE 5
895#define REPLY_TIMEOUT 10
896#define MAX_RETRIES 3
897#define MAX_SERVERS 3
898#define MAX_SEARCH 4
899#define MAX_ALIASES 5
900
901/* 1:ip + 1:full + MAX_ALIASES:aliases + 1:NULL */
902#define ALIAS_DIM (2 + MAX_ALIASES + 1)
903
904static int __nameservers;
905static char * __nameserver[MAX_SERVERS];
906static int __searchdomains;
907static char * __searchdomain[MAX_SEARCH];
908
909#undef DEBUG
910/* #define DEBUG */
911
912#ifdef DEBUG
913/* flawfinder: ignore *//* definition of debug macro */
914#define DPRINTF(X,args...) fprintf(stderr, X, ##args)
915#else
916#define DPRINTF(X,args...)
917#endif /* DEBUG */
918
919struct resolv_header {
920 int id;
921 int qr,opcode,aa,tc,rd,ra,rcode;
922 int qdcount;
923 int ancount;
924 int nscount;
925 int arcount;
926};
927
928struct resolv_question {
929 char * dotted;
930 int qtype;
931 int qclass;
932};
933
934struct resolv_answer {
935 char * dotted;
936 int atype;
937 int aclass;
938 int ttl;
939 int rdlength;
940 unsigned char * rdata;
941 int rdoffset;
942};
943
944enum etc_hosts_action {
945 GET_HOSTS_BYNAME = 0,
946 GETHOSTENT,
947 GET_HOSTS_BYADDR,
948};
949
950static int __encode_header(struct resolv_header *h, unsigned char *dest, int maxlen)
951{
952 if (maxlen < HFIXEDSZ)
953 return -1;
954
955 dest[0] = (h->id & 0xff00) >> 8;
956 dest[1] = (h->id & 0x00ff) >> 0;
957 dest[2] = (h->qr ? 0x80 : 0) |
958 ((h->opcode & 0x0f) << 3) |
959 (h->aa ? 0x04 : 0) |
960 (h->tc ? 0x02 : 0) |
961 (h->rd ? 0x01 : 0);
962 dest[3] = (h->ra ? 0x80 : 0) | (h->rcode & 0x0f);
963 dest[4] = (h->qdcount & 0xff00) >> 8;
964 dest[5] = (h->qdcount & 0x00ff) >> 0;
965 dest[6] = (h->ancount & 0xff00) >> 8;
966 dest[7] = (h->ancount & 0x00ff) >> 0;
967 dest[8] = (h->nscount & 0xff00) >> 8;
968 dest[9] = (h->nscount & 0x00ff) >> 0;
969 dest[10] = (h->arcount & 0xff00) >> 8;
970 dest[11] = (h->arcount & 0x00ff) >> 0;
971
972 return HFIXEDSZ;
973}
974
975static int __decode_header(unsigned char *data, struct resolv_header *h)
976{
977 h->id = (data[0] << 8) | data[1];
978 h->qr = (data[2] & 0x80) ? 1 : 0;
979 h->opcode = (data[2] >> 3) & 0x0f;
980 h->aa = (data[2] & 0x04) ? 1 : 0;
981 h->tc = (data[2] & 0x02) ? 1 : 0;
982 h->rd = (data[2] & 0x01) ? 1 : 0;
983 h->ra = (data[3] & 0x80) ? 1 : 0;
984 h->rcode = data[3] & 0x0f;
985 h->qdcount = (data[4] << 8) | data[5];
986 h->ancount = (data[6] << 8) | data[7];
987 h->nscount = (data[8] << 8) | data[9];
988 h->arcount = (data[10] << 8) | data[11];
989
990 return HFIXEDSZ;
991}
992
993static int __length_dotted(const unsigned char *data, int offset)
994{
995 int orig_offset = offset;
996 int l;
997
998 if (!data)
999 return -1;
1000
1001 do {
1002 l = data[offset];
1003 if (offset < INT_MAX)
1004 offset++;
1005 else
1006 return -1;
1007 if (!l)
1008 break;
1009
1010 DPRINTF("l[%d] = %d\n", offset, l);
1011
1012 if ((l & 0xc0) == (0xc0)) {
1013 if (offset < INT_MAX)
1014 offset++;
1015 else
1016 return -1;
1017 break;
1018 }
1019
1020 if (offset <= (INT_MAX - l))
1021 offset += l;
1022 else
1023 return -1;
1024
1025 } while (l);
1026
1027 DPRINTF("orig: %d now %d\n", orig_offset, offset);
1028 return offset - orig_offset;
1029}
1030
1031static int __length_question(unsigned char *message, int offset)
1032{
1033 int i;
1034
1035 i = __length_dotted(message, offset);
1036 if (i < 0)
1037 return i;
1038 if (i < (INT_MAX - 4))
1039 return i + 4;
1040 else
1041 return -1;
1042}
1043
1044/* Decode a dotted string from nameserver transport-level encoding.
1045 This routine understands compressed data. */
1046
1047static int __decode_dotted(const unsigned char *data, int offset,
1048 char *dest, int maxlen)
1049{
1050 int l;
1051 int measure = 1;
1052 int total = 0;
1053 int used = 0;
1054
1055 if (!data)
1056 return -1;
1057 if ((offset < 0) || (offset > (PACKETSZ-1)))
1058 return -1;
1059 while ((l=data[offset])) {
1060 if (offset < (PACKETSZ-1)) offset++;
1061 else return -1;
1062 if (measure)
1063 { if (total < INT_MAX) total++; else return -1; }
1064 if ((l & 0xc0) == (0xc0)) {
1065 if (measure)
1066 { if (total < INT_MAX) total++; else return -1; }
1067 /* compressed item, redirect */
1068 offset = ((l & 0x3f) << 8) | data[offset];
1069 if ((offset < 0) || (offset > (PACKETSZ-1)))
1070 return -1;
1071 measure = 0;
1072 continue;
1073 }
1074
1075 if (used >= (INT_MAX - l))
1076 return -1;
1077
1078 if ((used + l + 1) >= maxlen)
1079 return -1;
1080
1081 memcpy(dest + used, data + offset, l);
1082
1083 if (offset <= ((PACKETSZ-1) - l))
1084 offset += l;
1085 else
1086 return -1;
1087
1088 if (used <= (INT_MAX - l))
1089 used += l;
1090 else
1091 return -1;
1092 if (measure)
1093 { if (total <= (INT_MAX -l)) total += l; else return -1; }
1094
1095 if (used >= maxlen)
1096 return -1;
1097 if (data[offset] != 0)
1098 dest[used++] = '.';
1099 else
1100 dest[used++] = '\0';
1101 }
1102
1103 /* The null byte must be counted too */
1104 if (measure) {
1105 if (total < INT_MAX) total++; else return -1;
1106 }
1107
1108 DPRINTF("Total decode len = %d\n", total);
1109
1110 return total;
1111}
1112
1113static int __decode_answer(unsigned char *message, int offset,
1114 struct resolv_answer *a)
1115{
1116 char temp[256];
1117 int i = 0;
1118
1119 i = __decode_dotted(message, offset, temp, sizeof(temp));
1120 if (i < 0 || i > PACKETSZ)
1121 return -1;
1122
1123 if (offset <= ((PACKETSZ - 10) - i))
1124 message += offset + i;
1125 else
1126 return -1;
1127
1128 a->dotted = strdup(temp);
1129 a->atype = (message[0] << 8) | message[1];
1130 message += 2;
1131 a->aclass = (message[0] << 8) | message[1];
1132 message += 2;
1133 a->ttl = (message[0] << 24) |
1134 (message[1] << 16) | (message[2] << 8) | (message[3] << 0);
1135 message += 4;
1136 a->rdlength = (message[0] << 8) | message[1];
1137 message += 2;
1138 a->rdata = message;
1139 a->rdoffset = offset + i + RRFIXEDSZ;
1140
1141 DPRINTF("i=%d,rdlength=%d\n", i, a->rdlength);
1142
1143 if (RRFIXEDSZ <= (INT_MAX - i))
1144 i += RRFIXEDSZ;
1145 else
1146 return -1;
1147 if (a->rdlength <= (INT_MAX - i))
1148 return i + a->rdlength;
1149 else
1150 return -1;
1151}
1152
1153
1154/* Encode a dotted string into nameserver transport-level encoding.
1155 This routine is fairly dumb, and doesn't attempt to compress
1156 the data */
1157
1158static int __encode_dotted(const char *dotted, unsigned char *dest, int maxlen)
1159{
1160 unsigned int used = 0;
1161
1162 while (dotted && *dotted) {
1163 char *c = strchr(dotted, '.');
1164 unsigned int l = c ? (unsigned int)(c - dotted) : strlen(dotted);
1165
1166 if (l >= ((unsigned int)maxlen - used - 1))
1167 return -1;
1168
1169 dest[used++] = l;
1170 memcpy(dest + used, dotted, l);
1171 used += l;
1172
1173 if (c)
1174 dotted = c + 1;
1175 else
1176 break;
1177 }
1178
1179 if (maxlen < 1)
1180 return -1;
1181
1182 dest[used++] = 0;
1183
1184 return used;
1185}
1186
1187static int __encode_question(struct resolv_question *q,
1188 unsigned char *dest, int maxlen)
1189{
1190 int i;
1191
1192 i = __encode_dotted(q->dotted, dest, maxlen);
1193 if (i < 0)
1194 return i;
1195
1196 dest += i;
1197 if (maxlen < i)
1198 return -1;
1199 maxlen -= i;
1200
1201 if (maxlen < 4)
1202 return -1;
1203
1204 dest[0] = (q->qtype & 0xff00) >> 8;
1205 dest[1] = (q->qtype & 0x00ff) >> 0;
1206 dest[2] = (q->qclass & 0xff00) >> 8;
1207 dest[3] = (q->qclass & 0x00ff) >> 0;
1208
1209 if (i <= (INT_MAX - 4))
1210 return i + 4;
1211 else
1212 return -1;
1213}
1214
1215
1216/* Just for the record, having to lock __dns_lookup() just for these two globals
1217 * is pretty lame. I think these two variables can probably be de-global-ized,
1218 * which should eliminate the need for doing locking here... Needs a closer
1219 * look anyways. */
1220static int ns=0, id=1;
1221
1222static int __dns_lookup(const char *name, int type, int nscount, char **nsip,
1223 unsigned char **outpacket, struct resolv_answer *a)
1224{
1225 int i, j, len, fd, pos, rc;
1226 struct timeval tv;
1227 fd_set fds;
1228 struct resolv_header h;
1229 struct resolv_question q;
1230 int retries = 0;
1231 unsigned char * packet = calloc(1,PACKETSZ);
1232 char *dns, *lookup = calloc(1,MAXDNAME);
1233 int variant = 0;
1234 struct sockaddr_in sa;
1235#ifdef __UCLIBC_HAS_IPV6__
1236 int v6;
1237 struct sockaddr_in6 sa6;
1238#endif
1239
1240 fd = -1;
1241
1242 if (!packet || !lookup || !nscount)
1243 goto fail;
1244
1245 DPRINTF("Looking up type %d answer for '%s'\n", type, name);
1246
1247 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1248 ns %= nscount;
1249 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1250
1251 while (retries++ < MAX_RETRIES) {
1252 if (fd != -1)
1253 sl_close_fd(FIL__, __LINE__, fd);
1254
1255 memset(packet, 0, PACKETSZ);
1256
1257 memset(&h, 0, sizeof(h));
1258
1259 /* Mess with globals while under lock */
1260 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1261 ++id;
1262 id &= 0xffff;
1263 h.id = id;
1264 dns = nsip[ns];
1265 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1266
1267 h.qdcount = 1;
1268 h.rd = 1;
1269
1270 DPRINTF("encoding header %d\n", h.rd);
1271
1272 i = __encode_header(&h, packet, PACKETSZ);
1273 if (i < 0)
1274 goto fail;
1275
1276 sl_strlcpy(lookup,name,MAXDNAME);
1277 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1278 if (variant < __searchdomains && strchr(lookup, '.') == NULL)
1279 {
1280 sl_strlcat(lookup,".", MAXDNAME);
1281 sl_strlcat(lookup,__searchdomain[variant], MAXDNAME);
1282 }
1283 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1284 DPRINTF("lookup name: %s\n", lookup);
1285 q.dotted = (char *)lookup;
1286 q.qtype = type;
1287 q.qclass = C_IN; /* CLASS_IN */
1288
1289 j = __encode_question(&q, packet+i, PACKETSZ-i);
1290 if (j < 0)
1291 goto fail;
1292
1293 len = i + j;
1294
1295 DPRINTF("On try %d, sending query to port %d of machine %s\n",
1296 retries, NAMESERVER_PORT, dns);
1297
1298#ifdef __UCLIBC_HAS_IPV6__
1299 v6 = inet_pton(AF_INET6, dns, &sa6.sin6_addr) > 0;
1300 fd = socket(v6 ? AF_INET6 : AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1301#else
1302 fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1303#endif
1304 if (fd < 0) {
1305 continue;
1306 }
1307
1308 /* Connect to the UDP socket so that asyncronous errors are returned */
1309#ifdef __UCLIBC_HAS_IPV6__
1310 if (v6) {
1311 sa6.sin6_family = AF_INET6;
1312 sa6.sin6_port = htons(NAMESERVER_PORT);
1313 /* sa6.sin6_addr is already here */
1314 rc = connect(fd, (struct sockaddr *) &sa6, sizeof(sa6));
1315 } else {
1316#endif
1317 sa.sin_family = AF_INET;
1318 sa.sin_port = htons(NAMESERVER_PORT);
1319 sa.sin_addr.s_addr = inet_addr(dns);
1320 rc = connect(fd, (struct sockaddr *) &sa, sizeof(sa));
1321#ifdef __UCLIBC_HAS_IPV6__
1322 }
1323#endif
1324 if (rc < 0) {
1325 if (errno == ENETUNREACH) {
1326 /* routing error, presume not transient */
1327 goto tryall;
1328 } else
1329 /* retry */
1330 continue;
1331 }
1332
1333 DPRINTF("Transmitting packet of length %d, id=%d, qr=%d\n",
1334 len, h.id, h.qr);
1335
1336 send(fd, packet, len, 0);
1337
1338 FD_ZERO(&fds);
1339 FD_SET(fd, &fds);
1340 tv.tv_sec = REPLY_TIMEOUT;
1341 tv.tv_usec = 0;
1342 if (select(fd + 1, &fds, NULL, NULL, &tv) <= 0) {
1343 DPRINTF("Timeout\n");
1344
1345 /* timed out, so retry send and receive,
1346 * to next nameserver on queue */
1347 goto again;
1348 }
1349
1350 i = recv(fd, packet, 512, 0);
1351 if (i < HFIXEDSZ) {
1352 /* too short ! */
1353 goto again;
1354 }
1355
1356 /* ok because we have checked that recv at least HFIXEDSZ */
1357 __decode_header(packet, &h);
1358
1359 DPRINTF("id = %d, qr = %d\n", h.id, h.qr);
1360
1361 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1362 if ((h.id != id) || (!h.qr)) {
1363 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1364 /* unsolicited */
1365 goto again;
1366 }
1367 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1368
1369
1370 DPRINTF("Got response %s\n", "(i think)!");
1371 DPRINTF("qrcount=%d,ancount=%d,nscount=%d,arcount=%d\n",
1372 h.qdcount, h.ancount, h.nscount, h.arcount);
1373 DPRINTF("opcode=%d,aa=%d,tc=%d,rd=%d,ra=%d,rcode=%d\n",
1374 h.opcode, h.aa, h.tc, h.rd, h.ra, h.rcode);
1375
1376 if ((h.rcode) || (h.ancount < 1)) {
1377 /* negative result, not present */
1378 goto again;
1379 }
1380
1381 pos = HFIXEDSZ;
1382
1383 for (j = 0; j < h.qdcount; j++) {
1384 DPRINTF("Skipping question %d at %d\n", j, pos);
1385 i = __length_question(packet, pos);
1386 DPRINTF("Length of question %d is %d\n", j, i);
1387 if (i < 0)
1388 goto again;
1389 pos += i;
1390 if (pos >= PACKETSZ)
1391 goto again;
1392 }
1393 DPRINTF("Decoding answer at pos %d\n", pos);
1394
1395 for (j=0;j<h.ancount;j++)
1396 {
1397 i = __decode_answer(packet, pos, a);
1398
1399 if (i<0) {
1400 DPRINTF("failed decode %d\n", i);
1401 goto again;
1402 }
1403 /* For all but T_SIG, accept first answer */
1404 if (a->atype != T_SIG)
1405 break;
1406
1407 DPRINTF("skipping T_SIG %d\n", i);
1408 free(a->dotted);
1409 pos += i;
1410 if (pos >= PACKETSZ)
1411 goto again;
1412 }
1413
1414 DPRINTF("Answer name = |%s|\n", a->dotted);
1415 DPRINTF("Answer type = |%d|\n", a->atype);
1416
1417 sl_close_fd(FIL__, __LINE__, fd);
1418
1419 if (outpacket)
1420 *outpacket = packet;
1421 else
1422 free(packet);
1423 free(lookup);
1424 return (0); /* success! */
1425
1426 tryall:
1427 /* if there are other nameservers, give them a go,
1428 otherwise return with error */
1429 {
1430 int sdomains;
1431
1432 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1433 sdomains=__searchdomains;
1434 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1435 variant = 0;
1436 if (retries >= nscount*(sdomains+1))
1437 goto fail;
1438 }
1439
1440 again:
1441 /* if there are searchdomains, try them or fallback as passed */
1442 {
1443 int sdomains;
1444 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1445 sdomains=__searchdomains;
1446 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1447
1448 if (variant < sdomains) {
1449 /* next search */
1450 variant++;
1451 } else {
1452 /* next server, first search */
1453 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1454 ns = (ns + 1) % nscount;
1455 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1456 variant = 0;
1457 }
1458 }
1459 }
1460
1461fail:
1462 if (fd != -1)
1463 sl_close_fd(FIL__, __LINE__, fd);
1464 if (lookup)
1465 free(lookup);
1466 if (packet)
1467 free(packet);
1468 return -1;
1469}
1470
1471static void __open_etc_hosts(FILE **fp)
1472{
1473 if ((*fp = fopen("/etc/hosts", "r")) == NULL) {
1474 *fp = fopen("/etc/config/hosts", "r");
1475 }
1476 return;
1477}
1478
1479static int __read_etc_hosts_r(FILE * fp, const char * name, int type,
1480 enum etc_hosts_action action,
1481 struct hostent * result_buf,
1482 char * buf, size_t buflen,
1483 struct hostent ** result,
1484 int * h_errnop)
1485{
1486 struct in_addr *in=NULL;
1487 struct in_addr **addr_list=NULL;
1488#ifdef __UCLIBC_HAS_IPV6__
1489 struct in6_addr *in6=NULL;
1490 struct in6_addr **addr_list6=NULL;
1491#endif /* __UCLIBC_HAS_IPV6__ */
1492 char *cp;
1493 char **alias;
1494 int aliases, i;
1495 int ret=HOST_NOT_FOUND;
1496
1497 if (buflen < sizeof(char *)*(ALIAS_DIM))
1498 return ERANGE;
1499 alias=(char **)buf;
1500 buf+=sizeof(char **)*(ALIAS_DIM);
1501 buflen-=sizeof(char **)*(ALIAS_DIM);
1502
1503 if (action!=GETHOSTENT) {
1504#ifdef __UCLIBC_HAS_IPV6__
1505 char *p=buf;
1506 size_t len=buflen;
1507#endif /* __UCLIBC_HAS_IPV6__ */
1508 *h_errnop=NETDB_INTERNAL;
1509 if (buflen < sizeof(*in))
1510 return ERANGE;
1511 in=(struct in_addr*)buf;
1512 buf+=sizeof(*in);
1513 buflen-=sizeof(*in);
1514
1515 if (buflen < sizeof(*addr_list)*2)
1516 return ERANGE;
1517 addr_list=(struct in_addr **)buf;
1518 buf+=sizeof(*addr_list)*2;
1519 buflen-=sizeof(*addr_list)*2;
1520
1521#ifdef __UCLIBC_HAS_IPV6__
1522 if (len < sizeof(*in6))
1523 return ERANGE;
1524 in6=(struct in6_addr*)p;
1525 p+=sizeof(*in6);
1526 len-=sizeof(*in6);
1527
1528 if (len < sizeof(*addr_list6)*2)
1529 return ERANGE;
1530 addr_list6=(struct in6_addr**)p;
1531 p+=sizeof(*addr_list6)*2;
1532 len-=sizeof(*addr_list6)*2;
1533
1534 if (len < buflen) {
1535 buflen=len;
1536 buf=p;
1537 }
1538#endif /* __UCLIBC_HAS_IPV6__ */
1539
1540 if (buflen < 80)
1541 return ERANGE;
1542
1543 __open_etc_hosts(&fp);
1544 if (fp == NULL) {
1545 result=NULL;
1546 return errno;
1547 }
1548 }
1549
1550 *h_errnop=HOST_NOT_FOUND;
1551 while (fgets(buf, buflen, fp)) {
1552 if ((cp = strchr(buf, '#')))
1553 *cp = '\0';
1554 DPRINTF("Looking at: %s\n", buf);
1555 aliases = 0;
1556
1557 cp = buf;
1558 while (*cp) {
1559 while (*cp && isspace(*cp))
1560 *cp++ = '\0';
1561 if (!*cp)
1562 continue;
1563 if (aliases < (2+MAX_ALIASES))
1564 alias[aliases++] = cp;
1565 while (*cp && !isspace(*cp))
1566 cp++;
1567 }
1568 alias[aliases] = 0;
1569
1570 if (aliases < 2)
1571 continue; /* syntax error really */
1572
1573 if (action==GETHOSTENT) {
1574 /* Return whatever the next entry happens to be. */
1575 break;
1576 } else if (action==GET_HOSTS_BYADDR) {
1577 if (strcmp(name, alias[0]) != 0)
1578 continue;
1579 } else {
1580 /* GET_HOSTS_BYNAME */
1581 for (i = 1; i < aliases; i++)
1582 if (strcasecmp(name, alias[i]) == 0)
1583 break;
1584 if (i >= aliases)
1585 continue;
1586 }
1587
1588 if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) {
1589 DPRINTF("Found INET\n");
1590 addr_list[0] = in;
1591 addr_list[1] = 0;
1592 result_buf->h_name = alias[1];
1593 result_buf->h_addrtype = AF_INET;
1594 result_buf->h_length = sizeof(*in);
1595 result_buf->h_addr_list = (char**) addr_list;
1596 result_buf->h_aliases = alias + 2;
1597 *result=result_buf;
1598 ret=NETDB_SUCCESS;
1599#ifdef __UCLIBC_HAS_IPV6__
1600 } else if (type == AF_INET6 && inet_pton(AF_INET6, alias[0], in6) > 0) {
1601 DPRINTF("Found INET6\n");
1602 addr_list6[0] = in6;
1603 addr_list6[1] = 0;
1604 result_buf->h_name = alias[1];
1605 result_buf->h_addrtype = AF_INET6;
1606 result_buf->h_length = sizeof(*in6);
1607 result_buf->h_addr_list = (char**) addr_list6;
1608 result_buf->h_aliases = alias + 2;
1609 *result=result_buf;
1610 ret=NETDB_SUCCESS;
1611#endif /* __UCLIBC_HAS_IPV6__ */
1612 } else {
1613 DPRINTF("Error\n");
1614 ret=TRY_AGAIN;
1615 break; /* bad ip address */
1616 }
1617
1618 if (action!=GETHOSTENT) {
1619 sl_fclose(FIL__, __LINE__, fp);
1620 }
1621 return ret;
1622 }
1623 if (action!=GETHOSTENT) {
1624 sl_fclose(FIL__, __LINE__, fp);
1625 }
1626 return ret;
1627}
1628
1629/*
1630 * we currently read formats not quite the same as that on normal
1631 * unix systems, we can have a list of nameservers after the keyword.
1632 */
1633int __get_hosts_byname_r(const char * name, int type,
1634 struct hostent * result_buf,
1635 char * buf, size_t buflen,
1636 struct hostent ** result,
1637 int * h_errnop)
1638{
1639 return(__read_etc_hosts_r(NULL, name, type, GET_HOSTS_BYNAME, result_buf, buf, buflen, result, h_errnop));
1640}
1641
1642static int __open_nameservers(void)
1643{
1644 FILE *fp;
1645 int i;
1646#define RESOLV_ARGS 5
1647 char szBuffer[128], *p, *argv[RESOLV_ARGS];
1648 int argc;
1649
1650 SH_MUTEX_LOCK(resolv_lock);
1651 if (__nameservers > 0) {
1652 goto the_end;
1653 }
1654
1655 if ((fp = fopen("/etc/resolv.conf", "r")) ||
1656 (fp = fopen("/etc/config/resolv.conf", "r"))) {
1657
1658 while (fgets(szBuffer, sizeof(szBuffer), fp) != NULL) {
1659
1660 for (p = szBuffer; *p && isspace(*p); p++)
1661 /* skip white space */;
1662 if (*p == '\0' || *p == '\n' || *p == '#') /* skip comments etc */
1663 continue;
1664 argc = 0;
1665 while (*p && argc < RESOLV_ARGS) {
1666 argv[argc++] = p;
1667 while (*p && !isspace(*p) && *p != '\n')
1668 p++;
1669 while (*p && (isspace(*p) || *p == '\n')) /* remove spaces */
1670 *p++ = '\0';
1671 }
1672
1673 if (strcmp(argv[0], "nameserver") == 0) {
1674 for (i = 1; i < argc && __nameservers < MAX_SERVERS; i++) {
1675 __nameserver[__nameservers++] = strdup(argv[i]);
1676 DPRINTF("adding nameserver %s\n", argv[i]);
1677 }
1678 }
1679
1680 /* domain and search are mutually exclusive, the last one wins */
1681 if (strcmp(argv[0],"domain")==0 || strcmp(argv[0],"search")==0) {
1682 while (__searchdomains > 0) {
1683 free(__searchdomain[--__searchdomains]);
1684 __searchdomain[__searchdomains] = NULL;
1685 }
1686 for (i=1; i < argc && __searchdomains < MAX_SEARCH; i++) {
1687 __searchdomain[__searchdomains++] = strdup(argv[i]);
1688 DPRINTF("adding search %s\n", argv[i]);
1689 }
1690 }
1691 }
1692 sl_fclose(FIL__, __LINE__, fp);
1693 } else {
1694 DPRINTF("failed to open %s\n", "resolv.conf");
1695 }
1696 DPRINTF("nameservers = %d\n", __nameservers);
1697 the_end:
1698 ; /* 'label at end of compound statement' */
1699 SH_MUTEX_UNLOCK(resolv_lock);
1700 /* cppcheck-suppress resourceLeak */
1701 return 0;
1702}
1703
1704static int sh_gethostbyname_r(const char * name,
1705 struct hostent * result_buf,
1706 char * buf, size_t buflen,
1707 struct hostent ** result,
1708 int * h_errnop)
1709{
1710 struct in_addr *in;
1711 struct in_addr **addr_list;
1712 unsigned char *packet;
1713 struct resolv_answer a;
1714 int i;
1715 int nest = 0;
1716 int __nameserversXX;
1717 char ** __nameserverXX;
1718
1719 DPRINTF("sh_gethostbyname_r: /%s/\n", name);
1720 __open_nameservers();
1721
1722 *result=NULL;
1723 if (!name)
1724 return EINVAL;
1725
1726 /* do /etc/hosts first */
1727 if ((i=__get_hosts_byname_r(name, AF_INET, result_buf,
1728 buf, buflen, result, h_errnop))==0)
1729 return i;
1730 switch (*h_errnop) {
1731 case HOST_NOT_FOUND:
1732 case NO_ADDRESS:
1733 break;
1734 case NETDB_INTERNAL:
1735 if (errno == ENOENT) {
1736 break;
1737 }
1738 /* else fall through */
1739 default:
1740 return i;
1741 }
1742
1743 DPRINTF("Nothing found in /etc/hosts\n");
1744
1745 *h_errnop = NETDB_INTERNAL;
1746 if (buflen < sizeof(*in))
1747 return ERANGE;
1748 in=(struct in_addr*)buf;
1749 buf+=sizeof(*in);
1750 buflen-=sizeof(*in);
1751
1752 if (buflen < sizeof(*addr_list)*2)
1753 return ERANGE;
1754 addr_list=(struct in_addr**)buf;
1755 buf+=sizeof(*addr_list)*2;
1756 buflen-=sizeof(*addr_list)*2;
1757
1758 addr_list[0] = in;
1759 addr_list[1] = 0;
1760
1761 if (buflen<256)
1762 return ERANGE;
1763 strncpy(buf, name, buflen);
1764
1765 /* First check if this is already an address */
1766 if (inet_aton(name, in)) {
1767 result_buf->h_name = buf;
1768 result_buf->h_addrtype = AF_INET;
1769 result_buf->h_length = sizeof(*in);
1770 result_buf->h_addr_list = (char **) addr_list;
1771 *result=result_buf;
1772 *h_errnop = NETDB_SUCCESS;
1773 return NETDB_SUCCESS;
1774 }
1775
1776 for (;;) {
1777
1778 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1779 __nameserversXX=__nameservers;
1780 __nameserverXX=__nameserver;
1781 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1782 i = __dns_lookup(buf, T_A, __nameserversXX, __nameserverXX, &packet, &a);
1783
1784 if (i < 0) {
1785 *h_errnop = HOST_NOT_FOUND;
1786 DPRINTF("__dns_lookup\n");
1787 return TRY_AGAIN;
1788 }
1789
1790 strncpy(buf, a.dotted, buflen);
1791 free(a.dotted);
1792
1793 if (a.atype == T_CNAME) { /* CNAME */
1794 DPRINTF("Got a CNAME in gethostbyname()\n");
1795 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
1796 free(packet);
1797
1798 if (i < 0) {
1799 *h_errnop = NO_RECOVERY;
1800 DPRINTF("__decode_dotted\n");
1801 return -1;
1802 }
1803 if (++nest > MAX_RECURSE) {
1804 *h_errnop = NO_RECOVERY;
1805 DPRINTF("recursion\n");
1806 return -1;
1807 }
1808 continue;
1809 } else if (a.atype == T_A) { /* ADDRESS */
1810 memcpy(in, a.rdata, sizeof(*in));
1811 result_buf->h_name = buf;
1812 result_buf->h_addrtype = AF_INET;
1813 result_buf->h_length = sizeof(*in);
1814 result_buf->h_addr_list = (char **) addr_list;
1815 free(packet);
1816 break;
1817 } else {
1818 free(packet);
1819 *h_errnop=HOST_NOT_FOUND;
1820 DPRINTF("host_not_found\n");
1821 return TRY_AGAIN;
1822 }
1823 }
1824
1825 *result=result_buf;
1826 *h_errnop = NETDB_SUCCESS;
1827 return NETDB_SUCCESS;
1828}
1829
1830struct hostent * sh_gethostbyname(const char *name)
1831{
1832 static struct hostent h;
1833 static char buf[sizeof(struct in_addr) +
1834 sizeof(struct in_addr *)*2 +
1835 sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
1836 struct hostent *hp;
1837
1838 DPRINTF("sh_gethostbyname: /%s/\n", name);
1839 sh_gethostbyname_r(name, &h, buf, sizeof(buf), &hp, &h_errno);
1840 return hp;
1841}
1842
1843static int __get_hosts_byaddr_r(const char * addr, int len, int type,
1844 struct hostent * result_buf,
1845 char * buf, size_t buflen,
1846 struct hostent ** result,
1847 int * h_errnop)
1848{
1849#ifndef __UCLIBC_HAS_IPV6__
1850 char ipaddr[INET_ADDRSTRLEN];
1851#else
1852 char ipaddr[INET6_ADDRSTRLEN];
1853#endif /* __UCLIBC_HAS_IPV6__ */
1854
1855 switch (type) {
1856 case AF_INET:
1857 if (len != sizeof(struct in_addr))
1858 return 0;
1859 break;
1860#ifdef __UCLIBC_HAS_IPV6__
1861 case AF_INET6:
1862 if (len != sizeof(struct in6_addr))
1863 return 0;
1864 break;
1865#endif /* __UCLIBC_HAS_IPV6__ */
1866 default:
1867 return 0;
1868 }
1869
1870 inet_ntop(type, addr, ipaddr, sizeof(ipaddr));
1871
1872 return(__read_etc_hosts_r(NULL, ipaddr, type, GET_HOSTS_BYADDR,
1873 result_buf, buf, buflen, result, h_errnop));
1874}
1875
1876static int sh_gethostbyaddr_r (const void *addr, socklen_t len, int type,
1877 struct hostent * result_buf,
1878 char * buf, size_t buflen,
1879 struct hostent ** result,
1880 int * h_errnop)
1881
1882{
1883 struct in_addr *in;
1884 struct in_addr **addr_list;
1885#ifdef __UCLIBC_HAS_IPV6__
1886 char *qp;
1887 size_t plen;
1888 struct in6_addr *in6;
1889 struct in6_addr **addr_list6;
1890#endif /* __UCLIBC_HAS_IPV6__ */
1891 unsigned char *packet;
1892 struct resolv_answer a;
1893 int i;
1894 int nest = 0;
1895 int __nameserversXX;
1896 char ** __nameserverXX;
1897
1898 DPRINTF("sh_gethostbyaddr_r called\n");
1899 *result=NULL;
1900 if (!addr)
1901 return EINVAL;
1902
1903 switch (type) {
1904 case AF_INET:
1905 if (len != sizeof(struct in_addr))
1906 return EINVAL;
1907 break;
1908#ifdef __UCLIBC_HAS_IPV6__
1909 case AF_INET6:
1910 if (len != sizeof(struct in6_addr))
1911 return EINVAL;
1912 break;
1913#endif /* __UCLIBC_HAS_IPV6__ */
1914 default:
1915 return EINVAL;
1916 }
1917
1918 /* do /etc/hosts first */
1919 if ((i=__get_hosts_byaddr_r(addr, len, type, result_buf,
1920 buf, buflen, result, h_errnop))==0)
1921 return i;
1922 switch (*h_errnop) {
1923 case HOST_NOT_FOUND:
1924 case NO_ADDRESS:
1925 break;
1926 default:
1927 return i;
1928 }
1929
1930 __open_nameservers();
1931
1932#ifdef __UCLIBC_HAS_IPV6__
1933 qp=buf;
1934 plen=buflen;
1935#endif /* __UCLIBC_HAS_IPV6__ */
1936
1937 *h_errnop = NETDB_INTERNAL;
1938 if (buflen < sizeof(*in))
1939 return ERANGE;
1940 in=(struct in_addr*)buf;
1941 buf+=sizeof(*in);
1942 buflen-=sizeof(*in);
1943
1944 if (buflen < sizeof(*addr_list)*2)
1945 return ERANGE;
1946 addr_list=(struct in_addr**)buf;
1947 buf+=sizeof(*addr_list)*2;
1948 buflen-=sizeof(*addr_list)*2;
1949
1950#ifdef __UCLIBC_HAS_IPV6__
1951 if (plen < sizeof(*in6))
1952 return ERANGE;
1953 in6=(struct in6_addr*)qp;
1954 qp+=sizeof(*in6);
1955 plen-=sizeof(*in6);
1956
1957 if (plen < sizeof(*addr_list6)*2)
1958 return ERANGE;
1959 addr_list6=(struct in6_addr**)qp;
1960 qp+=sizeof(*addr_list6)*2;
1961 plen-=sizeof(*addr_list6)*2;
1962
1963 if (plen < buflen) {
1964 buflen=plen;
1965 buf=qp;
1966 }
1967#endif /* __UCLIBC_HAS_IPV6__ */
1968
1969 if (buflen<256)
1970 return ERANGE;
1971
1972 if(type == AF_INET) {
1973 const unsigned char *tmp_addr = (const unsigned char *)addr;
1974
1975 memcpy(&in->s_addr, addr, len);
1976
1977 addr_list[0] = in;
1978
1979 sprintf(buf, "%u.%u.%u.%u.in-addr.arpa",
1980 tmp_addr[3], tmp_addr[2], tmp_addr[1], tmp_addr[0]);
1981#ifdef __UCLIBC_HAS_IPV6__
1982 } else {
1983 memcpy(in6->s6_addr, addr, len);
1984
1985 addr_list6[0] = in6;
1986 qp = buf;
1987
1988 for (i = len - 1; i >= 0; i--) {
1989 qp += sprintf(qp, "%x.%x.", in6->s6_addr[i] & 0xf,
1990 (in6->s6_addr[i] >> 4) & 0xf);
1991 }
1992 strcpy(qp, "ip6.int");
1993#endif /* __UCLIBC_HAS_IPV6__ */
1994 }
1995
1996 addr_list[1] = 0;
1997
1998 for (;;) {
1999
2000 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
2001 __nameserversXX=__nameservers;
2002 __nameserverXX=__nameserver;
2003 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
2004 i = __dns_lookup(buf, T_PTR, __nameserversXX, __nameserverXX, &packet, &a);
2005
2006 if (i < 0) {
2007 *h_errnop = HOST_NOT_FOUND;
2008 return TRY_AGAIN;
2009 }
2010
2011 strncpy(buf, a.dotted, buflen);
2012 free(a.dotted);
2013
2014 if (a.atype == T_CNAME) { /* CNAME */
2015 DPRINTF("Got a CNAME in gethostbyaddr()\n");
2016 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
2017 free(packet);
2018
2019 if (i < 0) {
2020 *h_errnop = NO_RECOVERY;
2021 return -1;
2022 }
2023 if (++nest > MAX_RECURSE) {
2024 *h_errnop = NO_RECOVERY;
2025 return -1;
2026 }
2027 continue;
2028 } else if (a.atype == T_PTR) { /* ADDRESS */
2029 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
2030 free(packet);
2031
2032 result_buf->h_name = buf;
2033 result_buf->h_addrtype = type;
2034
2035 if(type == AF_INET) {
2036 result_buf->h_length = sizeof(*in);
2037#ifdef __UCLIBC_HAS_IPV6__
2038 } else {
2039 result_buf->h_length = sizeof(*in6);
2040#endif /* __UCLIBC_HAS_IPV6__ */
2041 }
2042
2043 result_buf->h_addr_list = (char **) addr_list;
2044 break;
2045 } else {
2046 free(packet);
2047 *h_errnop = NO_ADDRESS;
2048 return TRY_AGAIN;
2049 }
2050 }
2051
2052 *result=result_buf;
2053 *h_errnop = NETDB_SUCCESS;
2054 return NETDB_SUCCESS;
2055}
2056
2057struct hostent * sh_gethostbyaddr (const void *addr, socklen_t len, int type)
2058{
2059 static struct hostent h;
2060 static char buf[
2061#ifndef __UCLIBC_HAS_IPV6__
2062 sizeof(struct in_addr) + sizeof(struct in_addr *)*2 +
2063#else
2064 sizeof(struct in6_addr) + sizeof(struct in6_addr *)*2 +
2065#endif /* __UCLIBC_HAS_IPV6__ */
2066 sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
2067 struct hostent *hp;
2068
2069 DPRINTF("sh_gethostbyaddr called\n");
2070 sh_gethostbyaddr_r(addr, len, type, &h, buf, sizeof(buf), &hp, &h_errno);
2071
2072 return hp;
2073}
2074
2075/* NEED_STATIC_LIBS */
2076#else
2077
2078/* include something to avoid empty compilation unit */
2079#include <stdio.h>
2080
2081#endif
2082
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