source: trunk/src/sh_static.c@ 501

Last change on this file since 501 was 501, checked in by katerina, 9 years ago

Fix for ticket #397 (regression in sh_static.c).
File size: 49.1 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
1003 if (offset < INT_MAX)
1004 offset++;
1005 else
1006 return -1;
1007
1008 l = data[offset];
1009
1010 if ((l & 0xc0) == (0xc0)) {
1011 if (offset < INT_MAX)
1012 offset++;
1013 else
1014 return -1;
1015 break;
1016 }
1017
1018 if (offset <= (INT_MAX - l))
1019 offset += l;
1020 else
1021 return -1;
1022
1023 } while (l);
1024
1025 return offset - orig_offset;
1026}
1027
1028static int __length_question(unsigned char *message, int offset)
1029{
1030 int i;
1031
1032 i = __length_dotted(message, offset);
1033 if (i < 0)
1034 return i;
1035 if (i < (INT_MAX - 4))
1036 return i + 4;
1037 else
1038 return -1;
1039}
1040
1041/* Decode a dotted string from nameserver transport-level encoding.
1042 This routine understands compressed data. */
1043
1044static int __decode_dotted(const unsigned char *data, int offset,
1045 char *dest, int maxlen)
1046{
1047 int l;
1048 int measure = 1;
1049 int total = 0;
1050 int used = 0;
1051
1052 if (!data)
1053 return -1;
1054 while ((l=data[offset])) {
1055 if (offset < INT_MAX) offset++;
1056 else return -1;
1057 if (measure)
1058 { if (total < INT_MAX) total++; else return -1; }
1059 if ((l & 0xc0) == (0xc0)) {
1060 if (measure)
1061 { if (total < INT_MAX) total++; else return -1; }
1062 /* compressed item, redirect */
1063 offset = ((l & 0x3f) << 8) | data[offset];
1064 if (offset < 0)
1065 return -1;
1066 measure = 0;
1067 continue;
1068 }
1069
1070 if (used >= (INT_MAX - l))
1071 return -1;
1072
1073 if ((used + l + 1) >= maxlen)
1074 return -1;
1075
1076 memcpy(dest + used, data + offset, l);
1077
1078 if (offset <= (INT_MAX - l))
1079 offset += l;
1080 else
1081 return -1;
1082
1083 if (used <= (INT_MAX - l))
1084 used += l;
1085 else
1086 return -1;
1087 if (measure)
1088 { if (total <= (INT_MAX -l)) total += l; else return -1; }
1089
1090 if (used == INT_MAX)
1091 return -1;
1092 if (data[offset] != 0)
1093 dest[used++] = '.';
1094 else
1095 dest[used++] = '\0';
1096 }
1097
1098 /* The null byte must be counted too */
1099 if (measure) {
1100 if (total < INT_MAX) total++; else return -1;
1101 }
1102
1103 DPRINTF("Total decode len = %d\n", total);
1104
1105 return total;
1106}
1107
1108static int __decode_answer(unsigned char *message, int offset,
1109 struct resolv_answer *a)
1110{
1111 char temp[256];
1112 int i = 0;
1113
1114 i = __decode_dotted(message, offset, temp, sizeof(temp));
1115 if (i < 0)
1116 return i;
1117
1118 if (offset <= (INT_MAX - i))
1119 message += offset + i;
1120 else
1121 return -1;
1122
1123 a->dotted = strdup(temp);
1124 a->atype = (message[0] << 8) | message[1];
1125 message += 2;
1126 a->aclass = (message[0] << 8) | message[1];
1127 message += 2;
1128 a->ttl = (message[0] << 24) |
1129 (message[1] << 16) | (message[2] << 8) | (message[3] << 0);
1130 message += 4;
1131 a->rdlength = (message[0] << 8) | message[1];
1132 message += 2;
1133 a->rdata = message;
1134 a->rdoffset = offset + i + RRFIXEDSZ;
1135
1136 DPRINTF("i=%d,rdlength=%d\n", i, a->rdlength);
1137
1138 if (RRFIXEDSZ <= (INT_MAX - i))
1139 i += RRFIXEDSZ;
1140 else
1141 return -1;
1142 if (a->rdlength <= (INT_MAX - i))
1143 return i + a->rdlength;
1144 else
1145 return -1;
1146}
1147
1148
1149/* Encode a dotted string into nameserver transport-level encoding.
1150 This routine is fairly dumb, and doesn't attempt to compress
1151 the data */
1152
1153static int __encode_dotted(const char *dotted, unsigned char *dest, int maxlen)
1154{
1155 unsigned int used = 0;
1156
1157 while (dotted && *dotted) {
1158 char *c = strchr(dotted, '.');
1159 unsigned int l = c ? (unsigned int)(c - dotted) : strlen(dotted);
1160
1161 if (l >= ((unsigned int)maxlen - used - 1))
1162 return -1;
1163
1164 dest[used++] = l;
1165 memcpy(dest + used, dotted, l);
1166 used += l;
1167
1168 if (c)
1169 dotted = c + 1;
1170 else
1171 break;
1172 }
1173
1174 if (maxlen < 1)
1175 return -1;
1176
1177 dest[used++] = 0;
1178
1179 return used;
1180}
1181
1182static int __encode_question(struct resolv_question *q,
1183 unsigned char *dest, int maxlen)
1184{
1185 int i;
1186
1187 i = __encode_dotted(q->dotted, dest, maxlen);
1188 if (i < 0)
1189 return i;
1190
1191 dest += i;
1192 if (maxlen < i)
1193 return -1;
1194 maxlen -= i;
1195
1196 if (maxlen < 4)
1197 return -1;
1198
1199 dest[0] = (q->qtype & 0xff00) >> 8;
1200 dest[1] = (q->qtype & 0x00ff) >> 0;
1201 dest[2] = (q->qclass & 0xff00) >> 8;
1202 dest[3] = (q->qclass & 0x00ff) >> 0;
1203
1204 if (i <= (INT_MAX - 4))
1205 return i + 4;
1206 else
1207 return -1;
1208}
1209
1210
1211/* Just for the record, having to lock __dns_lookup() just for these two globals
1212 * is pretty lame. I think these two variables can probably be de-global-ized,
1213 * which should eliminate the need for doing locking here... Needs a closer
1214 * look anyways. */
1215static int ns=0, id=1;
1216
1217static int __dns_lookup(const char *name, int type, int nscount, char **nsip,
1218 unsigned char **outpacket, struct resolv_answer *a)
1219{
1220 int i, j, len, fd, pos, rc;
1221 struct timeval tv;
1222 fd_set fds;
1223 struct resolv_header h;
1224 struct resolv_question q;
1225 int retries = 0;
1226 unsigned char * packet = calloc(1,PACKETSZ);
1227 char *dns, *lookup = calloc(1,MAXDNAME);
1228 int variant = 0;
1229 struct sockaddr_in sa;
1230#ifdef __UCLIBC_HAS_IPV6__
1231 int v6;
1232 struct sockaddr_in6 sa6;
1233#endif
1234
1235 fd = -1;
1236
1237 if (!packet || !lookup || !nscount)
1238 goto fail;
1239
1240 DPRINTF("Looking up type %d answer for '%s'\n", type, name);
1241
1242 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1243 ns %= nscount;
1244 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1245
1246 while (retries++ < MAX_RETRIES) {
1247 if (fd != -1)
1248 sl_close_fd(FIL__, __LINE__, fd);
1249
1250 memset(packet, 0, PACKETSZ);
1251
1252 memset(&h, 0, sizeof(h));
1253
1254 /* Mess with globals while under lock */
1255 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1256 ++id;
1257 id &= 0xffff;
1258 h.id = id;
1259 dns = nsip[ns];
1260 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1261
1262 h.qdcount = 1;
1263 h.rd = 1;
1264
1265 DPRINTF("encoding header\n", h.rd);
1266
1267 i = __encode_header(&h, packet, PACKETSZ);
1268 if (i < 0)
1269 goto fail;
1270
1271 sl_strlcpy(lookup,name,MAXDNAME);
1272 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1273 if (variant < __searchdomains && strchr(lookup, '.') == NULL)
1274 {
1275 sl_strlcat(lookup,".", MAXDNAME);
1276 sl_strlcat(lookup,__searchdomain[variant], MAXDNAME);
1277 }
1278 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1279 DPRINTF("lookup name: %s\n", lookup);
1280 q.dotted = (char *)lookup;
1281 q.qtype = type;
1282 q.qclass = C_IN; /* CLASS_IN */
1283
1284 j = __encode_question(&q, packet+i, PACKETSZ-i);
1285 if (j < 0)
1286 goto fail;
1287
1288 len = i + j;
1289
1290 DPRINTF("On try %d, sending query to port %d of machine %s\n",
1291 retries, NAMESERVER_PORT, dns);
1292
1293#ifdef __UCLIBC_HAS_IPV6__
1294 v6 = inet_pton(AF_INET6, dns, &sa6.sin6_addr) > 0;
1295 fd = socket(v6 ? AF_INET6 : AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1296#else
1297 fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1298#endif
1299 if (fd < 0) {
1300 continue;
1301 }
1302
1303 /* Connect to the UDP socket so that asyncronous errors are returned */
1304#ifdef __UCLIBC_HAS_IPV6__
1305 if (v6) {
1306 sa6.sin6_family = AF_INET6;
1307 sa6.sin6_port = htons(NAMESERVER_PORT);
1308 /* sa6.sin6_addr is already here */
1309 rc = connect(fd, (struct sockaddr *) &sa6, sizeof(sa6));
1310 } else {
1311#endif
1312 sa.sin_family = AF_INET;
1313 sa.sin_port = htons(NAMESERVER_PORT);
1314 sa.sin_addr.s_addr = inet_addr(dns);
1315 rc = connect(fd, (struct sockaddr *) &sa, sizeof(sa));
1316#ifdef __UCLIBC_HAS_IPV6__
1317 }
1318#endif
1319 if (rc < 0) {
1320 if (errno == ENETUNREACH) {
1321 /* routing error, presume not transient */
1322 goto tryall;
1323 } else
1324 /* retry */
1325 continue;
1326 }
1327
1328 DPRINTF("Transmitting packet of length %d, id=%d, qr=%d\n",
1329 len, h.id, h.qr);
1330
1331 send(fd, packet, len, 0);
1332
1333 FD_ZERO(&fds);
1334 FD_SET(fd, &fds);
1335 tv.tv_sec = REPLY_TIMEOUT;
1336 tv.tv_usec = 0;
1337 if (select(fd + 1, &fds, NULL, NULL, &tv) <= 0) {
1338 DPRINTF("Timeout\n");
1339
1340 /* timed out, so retry send and receive,
1341 * to next nameserver on queue */
1342 goto again;
1343 }
1344
1345 i = recv(fd, packet, 512, 0);
1346 if (i < HFIXEDSZ) {
1347 /* too short ! */
1348 goto again;
1349 }
1350
1351 __decode_header(packet, &h);
1352
1353 DPRINTF("id = %d, qr = %d\n", h.id, h.qr);
1354
1355 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1356 if ((h.id != id) || (!h.qr)) {
1357 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1358 /* unsolicited */
1359 goto again;
1360 }
1361 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1362
1363
1364 DPRINTF("Got response %s\n", "(i think)!");
1365 DPRINTF("qrcount=%d,ancount=%d,nscount=%d,arcount=%d\n",
1366 h.qdcount, h.ancount, h.nscount, h.arcount);
1367 DPRINTF("opcode=%d,aa=%d,tc=%d,rd=%d,ra=%d,rcode=%d\n",
1368 h.opcode, h.aa, h.tc, h.rd, h.ra, h.rcode);
1369
1370 if ((h.rcode) || (h.ancount < 1)) {
1371 /* negative result, not present */
1372 goto again;
1373 }
1374
1375 pos = HFIXEDSZ;
1376
1377 for (j = 0; j < h.qdcount; j++) {
1378 DPRINTF("Skipping question %d at %d\n", j, pos);
1379 i = __length_question(packet, pos);
1380 DPRINTF("Length of question %d is %d\n", j, i);
1381 if (i < 0)
1382 goto again;
1383 pos += i;
1384 }
1385 DPRINTF("Decoding answer at pos %d\n", pos);
1386
1387 for (j=0;j<h.ancount;j++)
1388 {
1389 i = __decode_answer(packet, pos, a);
1390
1391 if (i<0) {
1392 DPRINTF("failed decode %d\n", i);
1393 goto again;
1394 }
1395 /* For all but T_SIG, accept first answer */
1396 if (a->atype != T_SIG)
1397 break;
1398
1399 DPRINTF("skipping T_SIG %d\n", i);
1400 free(a->dotted);
1401 pos += i;
1402 }
1403
1404 DPRINTF("Answer name = |%s|\n", a->dotted);
1405 DPRINTF("Answer type = |%d|\n", a->atype);
1406
1407 sl_close_fd(FIL__, __LINE__, fd);
1408
1409 if (outpacket)
1410 *outpacket = packet;
1411 else
1412 free(packet);
1413 free(lookup);
1414 return (0); /* success! */
1415
1416 tryall:
1417 /* if there are other nameservers, give them a go,
1418 otherwise return with error */
1419 {
1420 int sdomains;
1421
1422 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1423 sdomains=__searchdomains;
1424 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1425 variant = 0;
1426 if (retries >= nscount*(sdomains+1))
1427 goto fail;
1428 }
1429
1430 again:
1431 /* if there are searchdomains, try them or fallback as passed */
1432 {
1433 int sdomains;
1434 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1435 sdomains=__searchdomains;
1436 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1437
1438 if (variant < sdomains) {
1439 /* next search */
1440 variant++;
1441 } else {
1442 /* next server, first search */
1443 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1444 ns = (ns + 1) % nscount;
1445 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1446 variant = 0;
1447 }
1448 }
1449 }
1450
1451fail:
1452 if (fd != -1)
1453 sl_close_fd(FIL__, __LINE__, fd);
1454 if (lookup)
1455 free(lookup);
1456 if (packet)
1457 free(packet);
1458 return -1;
1459}
1460
1461static void __open_etc_hosts(FILE **fp)
1462{
1463 if ((*fp = fopen("/etc/hosts", "r")) == NULL) {
1464 *fp = fopen("/etc/config/hosts", "r");
1465 }
1466 return;
1467}
1468
1469static int __read_etc_hosts_r(FILE * fp, const char * name, int type,
1470 enum etc_hosts_action action,
1471 struct hostent * result_buf,
1472 char * buf, size_t buflen,
1473 struct hostent ** result,
1474 int * h_errnop)
1475{
1476 struct in_addr *in=NULL;
1477 struct in_addr **addr_list=NULL;
1478#ifdef __UCLIBC_HAS_IPV6__
1479 struct in6_addr *in6=NULL;
1480 struct in6_addr **addr_list6=NULL;
1481#endif /* __UCLIBC_HAS_IPV6__ */
1482 char *cp;
1483 char **alias;
1484 int aliases, i;
1485 int ret=HOST_NOT_FOUND;
1486
1487 if (buflen < sizeof(char *)*(ALIAS_DIM))
1488 return ERANGE;
1489 alias=(char **)buf;
1490 buf+=sizeof(char **)*(ALIAS_DIM);
1491 buflen-=sizeof(char **)*(ALIAS_DIM);
1492
1493 if (action!=GETHOSTENT) {
1494#ifdef __UCLIBC_HAS_IPV6__
1495 char *p=buf;
1496 size_t len=buflen;
1497#endif /* __UCLIBC_HAS_IPV6__ */
1498 *h_errnop=NETDB_INTERNAL;
1499 if (buflen < sizeof(*in))
1500 return ERANGE;
1501 in=(struct in_addr*)buf;
1502 buf+=sizeof(*in);
1503 buflen-=sizeof(*in);
1504
1505 if (buflen < sizeof(*addr_list)*2)
1506 return ERANGE;
1507 addr_list=(struct in_addr **)buf;
1508 buf+=sizeof(*addr_list)*2;
1509 buflen-=sizeof(*addr_list)*2;
1510
1511#ifdef __UCLIBC_HAS_IPV6__
1512 if (len < sizeof(*in6))
1513 return ERANGE;
1514 in6=(struct in6_addr*)p;
1515 p+=sizeof(*in6);
1516 len-=sizeof(*in6);
1517
1518 if (len < sizeof(*addr_list6)*2)
1519 return ERANGE;
1520 addr_list6=(struct in6_addr**)p;
1521 p+=sizeof(*addr_list6)*2;
1522 len-=sizeof(*addr_list6)*2;
1523
1524 if (len < buflen) {
1525 buflen=len;
1526 buf=p;
1527 }
1528#endif /* __UCLIBC_HAS_IPV6__ */
1529
1530 if (buflen < 80)
1531 return ERANGE;
1532
1533 __open_etc_hosts(&fp);
1534 if (fp == NULL) {
1535 result=NULL;
1536 return errno;
1537 }
1538 }
1539
1540 *h_errnop=HOST_NOT_FOUND;
1541 while (fgets(buf, buflen, fp)) {
1542 if ((cp = strchr(buf, '#')))
1543 *cp = '\0';
1544 DPRINTF("Looking at: %s\n", buf);
1545 aliases = 0;
1546
1547 cp = buf;
1548 while (*cp) {
1549 while (*cp && isspace(*cp))
1550 *cp++ = '\0';
1551 if (!*cp)
1552 continue;
1553 if (aliases < (2+MAX_ALIASES))
1554 alias[aliases++] = cp;
1555 while (*cp && !isspace(*cp))
1556 cp++;
1557 }
1558 alias[aliases] = 0;
1559
1560 if (aliases < 2)
1561 continue; /* syntax error really */
1562
1563 if (action==GETHOSTENT) {
1564 /* Return whatever the next entry happens to be. */
1565 break;
1566 } else if (action==GET_HOSTS_BYADDR) {
1567 if (strcmp(name, alias[0]) != 0)
1568 continue;
1569 } else {
1570 /* GET_HOSTS_BYNAME */
1571 for (i = 1; i < aliases; i++)
1572 if (strcasecmp(name, alias[i]) == 0)
1573 break;
1574 if (i >= aliases)
1575 continue;
1576 }
1577
1578 if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) {
1579 DPRINTF("Found INET\n");
1580 addr_list[0] = in;
1581 addr_list[1] = 0;
1582 result_buf->h_name = alias[1];
1583 result_buf->h_addrtype = AF_INET;
1584 result_buf->h_length = sizeof(*in);
1585 result_buf->h_addr_list = (char**) addr_list;
1586 result_buf->h_aliases = alias + 2;
1587 *result=result_buf;
1588 ret=NETDB_SUCCESS;
1589#ifdef __UCLIBC_HAS_IPV6__
1590 } else if (type == AF_INET6 && inet_pton(AF_INET6, alias[0], in6) > 0) {
1591 DPRINTF("Found INET6\n");
1592 addr_list6[0] = in6;
1593 addr_list6[1] = 0;
1594 result_buf->h_name = alias[1];
1595 result_buf->h_addrtype = AF_INET6;
1596 result_buf->h_length = sizeof(*in6);
1597 result_buf->h_addr_list = (char**) addr_list6;
1598 result_buf->h_aliases = alias + 2;
1599 *result=result_buf;
1600 ret=NETDB_SUCCESS;
1601#endif /* __UCLIBC_HAS_IPV6__ */
1602 } else {
1603 DPRINTF("Error\n");
1604 ret=TRY_AGAIN;
1605 break; /* bad ip address */
1606 }
1607
1608 if (action!=GETHOSTENT) {
1609 sl_fclose(FIL__, __LINE__, fp);
1610 }
1611 return ret;
1612 }
1613 if (action!=GETHOSTENT) {
1614 sl_fclose(FIL__, __LINE__, fp);
1615 }
1616 return ret;
1617}
1618
1619/*
1620 * we currently read formats not quite the same as that on normal
1621 * unix systems, we can have a list of nameservers after the keyword.
1622 */
1623int __get_hosts_byname_r(const char * name, int type,
1624 struct hostent * result_buf,
1625 char * buf, size_t buflen,
1626 struct hostent ** result,
1627 int * h_errnop)
1628{
1629 return(__read_etc_hosts_r(NULL, name, type, GET_HOSTS_BYNAME, result_buf, buf, buflen, result, h_errnop));
1630}
1631
1632static int __open_nameservers(void)
1633{
1634 FILE *fp;
1635 int i;
1636#define RESOLV_ARGS 5
1637 char szBuffer[128], *p, *argv[RESOLV_ARGS];
1638 int argc;
1639
1640 SH_MUTEX_LOCK(resolv_lock);
1641 if (__nameservers > 0) {
1642 goto the_end;
1643 }
1644
1645 if ((fp = fopen("/etc/resolv.conf", "r")) ||
1646 (fp = fopen("/etc/config/resolv.conf", "r"))) {
1647
1648 while (fgets(szBuffer, sizeof(szBuffer), fp) != NULL) {
1649
1650 for (p = szBuffer; *p && isspace(*p); p++)
1651 /* skip white space */;
1652 if (*p == '\0' || *p == '\n' || *p == '#') /* skip comments etc */
1653 continue;
1654 argc = 0;
1655 while (*p && argc < RESOLV_ARGS) {
1656 argv[argc++] = p;
1657 while (*p && !isspace(*p) && *p != '\n')
1658 p++;
1659 while (*p && (isspace(*p) || *p == '\n')) /* remove spaces */
1660 *p++ = '\0';
1661 }
1662
1663 if (strcmp(argv[0], "nameserver") == 0) {
1664 for (i = 1; i < argc && __nameservers < MAX_SERVERS; i++) {
1665 __nameserver[__nameservers++] = strdup(argv[i]);
1666 DPRINTF("adding nameserver %s\n", argv[i]);
1667 }
1668 }
1669
1670 /* domain and search are mutually exclusive, the last one wins */
1671 if (strcmp(argv[0],"domain")==0 || strcmp(argv[0],"search")==0) {
1672 while (__searchdomains > 0) {
1673 free(__searchdomain[--__searchdomains]);
1674 __searchdomain[__searchdomains] = NULL;
1675 }
1676 for (i=1; i < argc && __searchdomains < MAX_SEARCH; i++) {
1677 __searchdomain[__searchdomains++] = strdup(argv[i]);
1678 DPRINTF("adding search %s\n", argv[i]);
1679 }
1680 }
1681 }
1682 sl_fclose(FIL__, __LINE__, fp);
1683 } else {
1684 DPRINTF("failed to open %s\n", "resolv.conf");
1685 }
1686 DPRINTF("nameservers = %d\n", __nameservers);
1687 the_end:
1688 ; /* 'label at end of compound statement' */
1689 SH_MUTEX_UNLOCK(resolv_lock);
1690 /* cppcheck-suppress resourceLeak */
1691 return 0;
1692}
1693
1694static int sh_gethostbyname_r(const char * name,
1695 struct hostent * result_buf,
1696 char * buf, size_t buflen,
1697 struct hostent ** result,
1698 int * h_errnop)
1699{
1700 struct in_addr *in;
1701 struct in_addr **addr_list;
1702 unsigned char *packet;
1703 struct resolv_answer a;
1704 int i;
1705 int nest = 0;
1706 int __nameserversXX;
1707 char ** __nameserverXX;
1708
1709 __open_nameservers();
1710
1711 *result=NULL;
1712 if (!name)
1713 return EINVAL;
1714
1715 /* do /etc/hosts first */
1716 if ((i=__get_hosts_byname_r(name, AF_INET, result_buf,
1717 buf, buflen, result, h_errnop))==0)
1718 return i;
1719 switch (*h_errnop) {
1720 case HOST_NOT_FOUND:
1721 case NO_ADDRESS:
1722 break;
1723 case NETDB_INTERNAL:
1724 if (errno == ENOENT) {
1725 break;
1726 }
1727 /* else fall through */
1728 default:
1729 return i;
1730 }
1731
1732 DPRINTF("Nothing found in /etc/hosts\n");
1733
1734 *h_errnop = NETDB_INTERNAL;
1735 if (buflen < sizeof(*in))
1736 return ERANGE;
1737 in=(struct in_addr*)buf;
1738 buf+=sizeof(*in);
1739 buflen-=sizeof(*in);
1740
1741 if (buflen < sizeof(*addr_list)*2)
1742 return ERANGE;
1743 addr_list=(struct in_addr**)buf;
1744 buf+=sizeof(*addr_list)*2;
1745 buflen-=sizeof(*addr_list)*2;
1746
1747 addr_list[0] = in;
1748 addr_list[1] = 0;
1749
1750 if (buflen<256)
1751 return ERANGE;
1752 strncpy(buf, name, buflen);
1753
1754 /* First check if this is already an address */
1755 if (inet_aton(name, in)) {
1756 result_buf->h_name = buf;
1757 result_buf->h_addrtype = AF_INET;
1758 result_buf->h_length = sizeof(*in);
1759 result_buf->h_addr_list = (char **) addr_list;
1760 *result=result_buf;
1761 *h_errnop = NETDB_SUCCESS;
1762 return NETDB_SUCCESS;
1763 }
1764
1765 for (;;) {
1766
1767 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1768 __nameserversXX=__nameservers;
1769 __nameserverXX=__nameserver;
1770 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1771 i = __dns_lookup(buf, T_A, __nameserversXX, __nameserverXX, &packet, &a);
1772
1773 if (i < 0) {
1774 *h_errnop = HOST_NOT_FOUND;
1775 DPRINTF("__dns_lookup\n");
1776 return TRY_AGAIN;
1777 }
1778
1779 strncpy(buf, a.dotted, buflen);
1780 free(a.dotted);
1781
1782 if (a.atype == T_CNAME) { /* CNAME */
1783 DPRINTF("Got a CNAME in gethostbyname()\n");
1784 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
1785 free(packet);
1786
1787 if (i < 0) {
1788 *h_errnop = NO_RECOVERY;
1789 DPRINTF("__decode_dotted\n");
1790 return -1;
1791 }
1792 if (++nest > MAX_RECURSE) {
1793 *h_errnop = NO_RECOVERY;
1794 DPRINTF("recursion\n");
1795 return -1;
1796 }
1797 continue;
1798 } else if (a.atype == T_A) { /* ADDRESS */
1799 memcpy(in, a.rdata, sizeof(*in));
1800 result_buf->h_name = buf;
1801 result_buf->h_addrtype = AF_INET;
1802 result_buf->h_length = sizeof(*in);
1803 result_buf->h_addr_list = (char **) addr_list;
1804 free(packet);
1805 break;
1806 } else {
1807 free(packet);
1808 *h_errnop=HOST_NOT_FOUND;
1809 return TRY_AGAIN;
1810 }
1811 }
1812
1813 *result=result_buf;
1814 *h_errnop = NETDB_SUCCESS;
1815 return NETDB_SUCCESS;
1816}
1817
1818struct hostent * sh_gethostbyname(const char *name)
1819{
1820 static struct hostent h;
1821 static char buf[sizeof(struct in_addr) +
1822 sizeof(struct in_addr *)*2 +
1823 sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
1824 struct hostent *hp;
1825
1826 sh_gethostbyname_r(name, &h, buf, sizeof(buf), &hp, &h_errno);
1827
1828 return hp;
1829}
1830
1831static int __get_hosts_byaddr_r(const char * addr, int len, int type,
1832 struct hostent * result_buf,
1833 char * buf, size_t buflen,
1834 struct hostent ** result,
1835 int * h_errnop)
1836{
1837#ifndef __UCLIBC_HAS_IPV6__
1838 char ipaddr[INET_ADDRSTRLEN];
1839#else
1840 char ipaddr[INET6_ADDRSTRLEN];
1841#endif /* __UCLIBC_HAS_IPV6__ */
1842
1843 switch (type) {
1844 case AF_INET:
1845 if (len != sizeof(struct in_addr))
1846 return 0;
1847 break;
1848#ifdef __UCLIBC_HAS_IPV6__
1849 case AF_INET6:
1850 if (len != sizeof(struct in6_addr))
1851 return 0;
1852 break;
1853#endif /* __UCLIBC_HAS_IPV6__ */
1854 default:
1855 return 0;
1856 }
1857
1858 inet_ntop(type, addr, ipaddr, sizeof(ipaddr));
1859
1860 return(__read_etc_hosts_r(NULL, ipaddr, type, GET_HOSTS_BYADDR,
1861 result_buf, buf, buflen, result, h_errnop));
1862}
1863
1864static int sh_gethostbyaddr_r (const void *addr, socklen_t len, int type,
1865 struct hostent * result_buf,
1866 char * buf, size_t buflen,
1867 struct hostent ** result,
1868 int * h_errnop)
1869
1870{
1871 struct in_addr *in;
1872 struct in_addr **addr_list;
1873#ifdef __UCLIBC_HAS_IPV6__
1874 char *qp;
1875 size_t plen;
1876 struct in6_addr *in6;
1877 struct in6_addr **addr_list6;
1878#endif /* __UCLIBC_HAS_IPV6__ */
1879 unsigned char *packet;
1880 struct resolv_answer a;
1881 int i;
1882 int nest = 0;
1883 int __nameserversXX;
1884 char ** __nameserverXX;
1885
1886 *result=NULL;
1887 if (!addr)
1888 return EINVAL;
1889
1890 switch (type) {
1891 case AF_INET:
1892 if (len != sizeof(struct in_addr))
1893 return EINVAL;
1894 break;
1895#ifdef __UCLIBC_HAS_IPV6__
1896 case AF_INET6:
1897 if (len != sizeof(struct in6_addr))
1898 return EINVAL;
1899 break;
1900#endif /* __UCLIBC_HAS_IPV6__ */
1901 default:
1902 return EINVAL;
1903 }
1904
1905 /* do /etc/hosts first */
1906 if ((i=__get_hosts_byaddr_r(addr, len, type, result_buf,
1907 buf, buflen, result, h_errnop))==0)
1908 return i;
1909 switch (*h_errnop) {
1910 case HOST_NOT_FOUND:
1911 case NO_ADDRESS:
1912 break;
1913 default:
1914 return i;
1915 }
1916
1917 __open_nameservers();
1918
1919#ifdef __UCLIBC_HAS_IPV6__
1920 qp=buf;
1921 plen=buflen;
1922#endif /* __UCLIBC_HAS_IPV6__ */
1923
1924 *h_errnop = NETDB_INTERNAL;
1925 if (buflen < sizeof(*in))
1926 return ERANGE;
1927 in=(struct in_addr*)buf;
1928 buf+=sizeof(*in);
1929 buflen-=sizeof(*in);
1930
1931 if (buflen < sizeof(*addr_list)*2)
1932 return ERANGE;
1933 addr_list=(struct in_addr**)buf;
1934 buf+=sizeof(*addr_list)*2;
1935 buflen-=sizeof(*addr_list)*2;
1936
1937#ifdef __UCLIBC_HAS_IPV6__
1938 if (plen < sizeof(*in6))
1939 return ERANGE;
1940 in6=(struct in6_addr*)qp;
1941 qp+=sizeof(*in6);
1942 plen-=sizeof(*in6);
1943
1944 if (plen < sizeof(*addr_list6)*2)
1945 return ERANGE;
1946 addr_list6=(struct in6_addr**)qp;
1947 qp+=sizeof(*addr_list6)*2;
1948 plen-=sizeof(*addr_list6)*2;
1949
1950 if (plen < buflen) {
1951 buflen=plen;
1952 buf=qp;
1953 }
1954#endif /* __UCLIBC_HAS_IPV6__ */
1955
1956 if (buflen<256)
1957 return ERANGE;
1958
1959 if(type == AF_INET) {
1960 const unsigned char *tmp_addr = (const unsigned char *)addr;
1961
1962 memcpy(&in->s_addr, addr, len);
1963
1964 addr_list[0] = in;
1965
1966 sprintf(buf, "%u.%u.%u.%u.in-addr.arpa",
1967 tmp_addr[3], tmp_addr[2], tmp_addr[1], tmp_addr[0]);
1968#ifdef __UCLIBC_HAS_IPV6__
1969 } else {
1970 memcpy(in6->s6_addr, addr, len);
1971
1972 addr_list6[0] = in6;
1973 qp = buf;
1974
1975 for (i = len - 1; i >= 0; i--) {
1976 qp += sprintf(qp, "%x.%x.", in6->s6_addr[i] & 0xf,
1977 (in6->s6_addr[i] >> 4) & 0xf);
1978 }
1979 strcpy(qp, "ip6.int");
1980#endif /* __UCLIBC_HAS_IPV6__ */
1981 }
1982
1983 addr_list[1] = 0;
1984
1985 for (;;) {
1986
1987 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1988 __nameserversXX=__nameservers;
1989 __nameserverXX=__nameserver;
1990 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1991 i = __dns_lookup(buf, T_PTR, __nameserversXX, __nameserverXX, &packet, &a);
1992
1993 if (i < 0) {
1994 *h_errnop = HOST_NOT_FOUND;
1995 return TRY_AGAIN;
1996 }
1997
1998 strncpy(buf, a.dotted, buflen);
1999 free(a.dotted);
2000
2001 if (a.atype == T_CNAME) { /* CNAME */
2002 DPRINTF("Got a CNAME in gethostbyaddr()\n");
2003 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
2004 free(packet);
2005
2006 if (i < 0) {
2007 *h_errnop = NO_RECOVERY;
2008 return -1;
2009 }
2010 if (++nest > MAX_RECURSE) {
2011 *h_errnop = NO_RECOVERY;
2012 return -1;
2013 }
2014 continue;
2015 } else if (a.atype == T_PTR) { /* ADDRESS */
2016 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
2017 free(packet);
2018
2019 result_buf->h_name = buf;
2020 result_buf->h_addrtype = type;
2021
2022 if(type == AF_INET) {
2023 result_buf->h_length = sizeof(*in);
2024#ifdef __UCLIBC_HAS_IPV6__
2025 } else {
2026 result_buf->h_length = sizeof(*in6);
2027#endif /* __UCLIBC_HAS_IPV6__ */
2028 }
2029
2030 result_buf->h_addr_list = (char **) addr_list;
2031 break;
2032 } else {
2033 free(packet);
2034 *h_errnop = NO_ADDRESS;
2035 return TRY_AGAIN;
2036 }
2037 }
2038
2039 *result=result_buf;
2040 *h_errnop = NETDB_SUCCESS;
2041 return NETDB_SUCCESS;
2042}
2043
2044struct hostent * sh_gethostbyaddr (const void *addr, socklen_t len, int type)
2045{
2046 static struct hostent h;
2047 static char buf[
2048#ifndef __UCLIBC_HAS_IPV6__
2049 sizeof(struct in_addr) + sizeof(struct in_addr *)*2 +
2050#else
2051 sizeof(struct in6_addr) + sizeof(struct in6_addr *)*2 +
2052#endif /* __UCLIBC_HAS_IPV6__ */
2053 sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
2054 struct hostent *hp;
2055
2056 sh_gethostbyaddr_r(addr, len, type, &h, buf, sizeof(buf), &hp, &h_errno);
2057
2058 return hp;
2059}
2060
2061/* NEED_STATIC_LIBS */
2062#else
2063
2064/* include something to avoid empty compilation unit */
2065#include <stdio.h>
2066
2067#endif
2068
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