source: trunk/src/sh_static.c@ 496

Last change on this file since 496 was 481, checked in by katerina, 9 years ago

Enhancements and fixes for tickets #374, #375, #376, #377, #378, and #379.
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 while ((l = data[offset])) {
1002
1003 if (offset < INT_MAX)
1004 offset++;
1005 else
1006 return -1;
1007
1008 if ((l & 0xc0) == (0xc0)) {
1009 if (offset < INT_MAX)
1010 offset++;
1011 else
1012 return -1;
1013 break;
1014 }
1015
1016 if (offset <= (INT_MAX - l))
1017 offset += l;
1018 else
1019 return -1;
1020 }
1021
1022 return offset - orig_offset;
1023}
1024
1025static int __length_question(unsigned char *message, int offset)
1026{
1027 int i;
1028
1029 i = __length_dotted(message, offset);
1030 if (i < 0)
1031 return i;
1032 if (i < (INT_MAX - 4))
1033 return i + 4;
1034 else
1035 return -1;
1036}
1037
1038/* Decode a dotted string from nameserver transport-level encoding.
1039 This routine understands compressed data. */
1040
1041static int __decode_dotted(const unsigned char *data, int offset,
1042 char *dest, int maxlen)
1043{
1044 int l;
1045 int measure = 1;
1046 int total = 0;
1047 int used = 0;
1048
1049 if (!data)
1050 return -1;
1051 while ((l=data[offset])) {
1052 if (offset < INT_MAX) offset++;
1053 else return -1;
1054 if (measure && (total < INT_MAX))
1055 total++;
1056 if ((l & 0xc0) == (0xc0)) {
1057 if (measure && (total < INT_MAX))
1058 total++;
1059 /* compressed item, redirect */
1060 offset = ((l & 0x3f) << 8) | data[offset];
1061 if (offset < 0)
1062 return -1;
1063 measure = 0;
1064 continue;
1065 }
1066
1067 if (used >= (INT_MAX - l))
1068 return -1;
1069
1070 if ((used + l + 1) >= maxlen)
1071 return -1;
1072
1073 memcpy(dest + used, data + offset, l);
1074
1075 if (offset <= (INT_MAX - l))
1076 offset += l;
1077 else
1078 return -1;
1079
1080 if (used <= (INT_MAX - l))
1081 used += l;
1082 else
1083 return -1;
1084 if (measure && (total <= (INT_MAX - l)))
1085 total += l;
1086
1087 if (used == INT_MAX)
1088 return -1;
1089 if (data[offset] != 0)
1090 dest[used++] = '.';
1091 else
1092 dest[used++] = '\0';
1093 }
1094
1095 /* The null byte must be counted too */
1096 if (measure && (total < INT_MAX)) {
1097 total++;
1098 }
1099
1100 DPRINTF("Total decode len = %d\n", total);
1101
1102 return total;
1103}
1104
1105static int __decode_answer(unsigned char *message, int offset,
1106 struct resolv_answer *a)
1107{
1108 char temp[256];
1109 int i = 0;
1110
1111 i = __decode_dotted(message, offset, temp, sizeof(temp));
1112 if (i < 0)
1113 return i;
1114
1115 if (offset <= (INT_MAX - i))
1116 message += offset + i;
1117 else
1118 return -1;
1119
1120 a->dotted = strdup(temp);
1121 a->atype = (message[0] << 8) | message[1];
1122 message += 2;
1123 a->aclass = (message[0] << 8) | message[1];
1124 message += 2;
1125 a->ttl = (message[0] << 24) |
1126 (message[1] << 16) | (message[2] << 8) | (message[3] << 0);
1127 message += 4;
1128 a->rdlength = (message[0] << 8) | message[1];
1129 message += 2;
1130 a->rdata = message;
1131 a->rdoffset = offset + i + RRFIXEDSZ;
1132
1133 DPRINTF("i=%d,rdlength=%d\n", i, a->rdlength);
1134
1135 if (RRFIXEDSZ <= (INT_MAX - i))
1136 i += RRFIXEDSZ;
1137 else
1138 return -1;
1139 if (a->rdlength <= (INT_MAX - i))
1140 return i + a->rdlength;
1141 else
1142 return -1;
1143}
1144
1145
1146/* Encode a dotted string into nameserver transport-level encoding.
1147 This routine is fairly dumb, and doesn't attempt to compress
1148 the data */
1149
1150static int __encode_dotted(const char *dotted, unsigned char *dest, int maxlen)
1151{
1152 unsigned int used = 0;
1153
1154 while (dotted && *dotted) {
1155 char *c = strchr(dotted, '.');
1156 unsigned int l = c ? (unsigned int)(c - dotted) : strlen(dotted);
1157
1158 if (l >= ((unsigned int)maxlen - used - 1))
1159 return -1;
1160
1161 dest[used++] = l;
1162 memcpy(dest + used, dotted, l);
1163 used += l;
1164
1165 if (c)
1166 dotted = c + 1;
1167 else
1168 break;
1169 }
1170
1171 if (maxlen < 1)
1172 return -1;
1173
1174 dest[used++] = 0;
1175
1176 return used;
1177}
1178
1179static int __encode_question(struct resolv_question *q,
1180 unsigned char *dest, int maxlen)
1181{
1182 int i;
1183
1184 i = __encode_dotted(q->dotted, dest, maxlen);
1185 if (i < 0)
1186 return i;
1187
1188 dest += i;
1189 if (maxlen < i)
1190 return -1;
1191 maxlen -= i;
1192
1193 if (maxlen < 4)
1194 return -1;
1195
1196 dest[0] = (q->qtype & 0xff00) >> 8;
1197 dest[1] = (q->qtype & 0x00ff) >> 0;
1198 dest[2] = (q->qclass & 0xff00) >> 8;
1199 dest[3] = (q->qclass & 0x00ff) >> 0;
1200
1201 if (i <= (INT_MAX - 4))
1202 return i + 4;
1203 else
1204 return -1;
1205}
1206
1207
1208/* Just for the record, having to lock __dns_lookup() just for these two globals
1209 * is pretty lame. I think these two variables can probably be de-global-ized,
1210 * which should eliminate the need for doing locking here... Needs a closer
1211 * look anyways. */
1212static int ns=0, id=1;
1213
1214static int __dns_lookup(const char *name, int type, int nscount, char **nsip,
1215 unsigned char **outpacket, struct resolv_answer *a)
1216{
1217 int i, j, len, fd, pos, rc;
1218 struct timeval tv;
1219 fd_set fds;
1220 struct resolv_header h;
1221 struct resolv_question q;
1222 int retries = 0;
1223 unsigned char * packet = calloc(1,PACKETSZ);
1224 char *dns, *lookup = calloc(1,MAXDNAME);
1225 int variant = 0;
1226 struct sockaddr_in sa;
1227#ifdef __UCLIBC_HAS_IPV6__
1228 int v6;
1229 struct sockaddr_in6 sa6;
1230#endif
1231
1232 fd = -1;
1233
1234 if (!packet || !lookup || !nscount)
1235 goto fail;
1236
1237 DPRINTF("Looking up type %d answer for '%s'\n", type, name);
1238
1239 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1240 ns %= nscount;
1241 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1242
1243 while (retries++ < MAX_RETRIES) {
1244 if (fd != -1)
1245 sl_close_fd(FIL__, __LINE__, fd);
1246
1247 memset(packet, 0, PACKETSZ);
1248
1249 memset(&h, 0, sizeof(h));
1250
1251 /* Mess with globals while under lock */
1252 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1253 ++id;
1254 id &= 0xffff;
1255 h.id = id;
1256 dns = nsip[ns];
1257 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1258
1259 h.qdcount = 1;
1260 h.rd = 1;
1261
1262 DPRINTF("encoding header\n", h.rd);
1263
1264 i = __encode_header(&h, packet, PACKETSZ);
1265 if (i < 0)
1266 goto fail;
1267
1268 sl_strlcpy(lookup,name,MAXDNAME);
1269 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1270 if (variant < __searchdomains && strchr(lookup, '.') == NULL)
1271 {
1272 sl_strlcat(lookup,".", MAXDNAME);
1273 sl_strlcat(lookup,__searchdomain[variant], MAXDNAME);
1274 }
1275 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1276 DPRINTF("lookup name: %s\n", lookup);
1277 q.dotted = (char *)lookup;
1278 q.qtype = type;
1279 q.qclass = C_IN; /* CLASS_IN */
1280
1281 j = __encode_question(&q, packet+i, PACKETSZ-i);
1282 if (j < 0)
1283 goto fail;
1284
1285 len = i + j;
1286
1287 DPRINTF("On try %d, sending query to port %d of machine %s\n",
1288 retries, NAMESERVER_PORT, dns);
1289
1290#ifdef __UCLIBC_HAS_IPV6__
1291 v6 = inet_pton(AF_INET6, dns, &sa6.sin6_addr) > 0;
1292 fd = socket(v6 ? AF_INET6 : AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1293#else
1294 fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
1295#endif
1296 if (fd < 0) {
1297 continue;
1298 }
1299
1300 /* Connect to the UDP socket so that asyncronous errors are returned */
1301#ifdef __UCLIBC_HAS_IPV6__
1302 if (v6) {
1303 sa6.sin6_family = AF_INET6;
1304 sa6.sin6_port = htons(NAMESERVER_PORT);
1305 /* sa6.sin6_addr is already here */
1306 rc = connect(fd, (struct sockaddr *) &sa6, sizeof(sa6));
1307 } else {
1308#endif
1309 sa.sin_family = AF_INET;
1310 sa.sin_port = htons(NAMESERVER_PORT);
1311 sa.sin_addr.s_addr = inet_addr(dns);
1312 rc = connect(fd, (struct sockaddr *) &sa, sizeof(sa));
1313#ifdef __UCLIBC_HAS_IPV6__
1314 }
1315#endif
1316 if (rc < 0) {
1317 if (errno == ENETUNREACH) {
1318 /* routing error, presume not transient */
1319 goto tryall;
1320 } else
1321 /* retry */
1322 continue;
1323 }
1324
1325 DPRINTF("Transmitting packet of length %d, id=%d, qr=%d\n",
1326 len, h.id, h.qr);
1327
1328 send(fd, packet, len, 0);
1329
1330 FD_ZERO(&fds);
1331 FD_SET(fd, &fds);
1332 tv.tv_sec = REPLY_TIMEOUT;
1333 tv.tv_usec = 0;
1334 if (select(fd + 1, &fds, NULL, NULL, &tv) <= 0) {
1335 DPRINTF("Timeout\n");
1336
1337 /* timed out, so retry send and receive,
1338 * to next nameserver on queue */
1339 goto again;
1340 }
1341
1342 i = recv(fd, packet, 512, 0);
1343 if (i < HFIXEDSZ) {
1344 /* too short ! */
1345 goto again;
1346 }
1347
1348 __decode_header(packet, &h);
1349
1350 DPRINTF("id = %d, qr = %d\n", h.id, h.qr);
1351
1352 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1353 if ((h.id != id) || (!h.qr)) {
1354 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1355 /* unsolicited */
1356 goto again;
1357 }
1358 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1359
1360
1361 DPRINTF("Got response %s\n", "(i think)!");
1362 DPRINTF("qrcount=%d,ancount=%d,nscount=%d,arcount=%d\n",
1363 h.qdcount, h.ancount, h.nscount, h.arcount);
1364 DPRINTF("opcode=%d,aa=%d,tc=%d,rd=%d,ra=%d,rcode=%d\n",
1365 h.opcode, h.aa, h.tc, h.rd, h.ra, h.rcode);
1366
1367 if ((h.rcode) || (h.ancount < 1)) {
1368 /* negative result, not present */
1369 goto again;
1370 }
1371
1372 pos = HFIXEDSZ;
1373
1374 for (j = 0; j < h.qdcount; j++) {
1375 DPRINTF("Skipping question %d at %d\n", j, pos);
1376 i = __length_question(packet, pos);
1377 DPRINTF("Length of question %d is %d\n", j, i);
1378 if (i < 0)
1379 goto again;
1380 pos += i;
1381 }
1382 DPRINTF("Decoding answer at pos %d\n", pos);
1383
1384 for (j=0;j<h.ancount;j++)
1385 {
1386 i = __decode_answer(packet, pos, a);
1387
1388 if (i<0) {
1389 DPRINTF("failed decode %d\n", i);
1390 goto again;
1391 }
1392 /* For all but T_SIG, accept first answer */
1393 if (a->atype != T_SIG)
1394 break;
1395
1396 DPRINTF("skipping T_SIG %d\n", i);
1397 free(a->dotted);
1398 pos += i;
1399 }
1400
1401 DPRINTF("Answer name = |%s|\n", a->dotted);
1402 DPRINTF("Answer type = |%d|\n", a->atype);
1403
1404 sl_close_fd(FIL__, __LINE__, fd);
1405
1406 if (outpacket)
1407 *outpacket = packet;
1408 else
1409 free(packet);
1410 free(lookup);
1411 return (0); /* success! */
1412
1413 tryall:
1414 /* if there are other nameservers, give them a go,
1415 otherwise return with error */
1416 {
1417 int sdomains;
1418
1419 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1420 sdomains=__searchdomains;
1421 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1422 variant = 0;
1423 if (retries >= nscount*(sdomains+1))
1424 goto fail;
1425 }
1426
1427 again:
1428 /* if there are searchdomains, try them or fallback as passed */
1429 {
1430 int sdomains;
1431 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1432 sdomains=__searchdomains;
1433 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1434
1435 if (variant < sdomains) {
1436 /* next search */
1437 variant++;
1438 } else {
1439 /* next server, first search */
1440 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1441 ns = (ns + 1) % nscount;
1442 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1443 variant = 0;
1444 }
1445 }
1446 }
1447
1448fail:
1449 if (fd != -1)
1450 sl_close_fd(FIL__, __LINE__, fd);
1451 if (lookup)
1452 free(lookup);
1453 if (packet)
1454 free(packet);
1455 return -1;
1456}
1457
1458static void __open_etc_hosts(FILE **fp)
1459{
1460 if ((*fp = fopen("/etc/hosts", "r")) == NULL) {
1461 *fp = fopen("/etc/config/hosts", "r");
1462 }
1463 return;
1464}
1465
1466static int __read_etc_hosts_r(FILE * fp, const char * name, int type,
1467 enum etc_hosts_action action,
1468 struct hostent * result_buf,
1469 char * buf, size_t buflen,
1470 struct hostent ** result,
1471 int * h_errnop)
1472{
1473 struct in_addr *in=NULL;
1474 struct in_addr **addr_list=NULL;
1475#ifdef __UCLIBC_HAS_IPV6__
1476 struct in6_addr *in6=NULL;
1477 struct in6_addr **addr_list6=NULL;
1478#endif /* __UCLIBC_HAS_IPV6__ */
1479 char *cp;
1480 char **alias;
1481 int aliases, i;
1482 int ret=HOST_NOT_FOUND;
1483
1484 if (buflen < sizeof(char *)*(ALIAS_DIM))
1485 return ERANGE;
1486 alias=(char **)buf;
1487 buf+=sizeof(char **)*(ALIAS_DIM);
1488 buflen-=sizeof(char **)*(ALIAS_DIM);
1489
1490 if (action!=GETHOSTENT) {
1491#ifdef __UCLIBC_HAS_IPV6__
1492 char *p=buf;
1493 size_t len=buflen;
1494#endif /* __UCLIBC_HAS_IPV6__ */
1495 *h_errnop=NETDB_INTERNAL;
1496 if (buflen < sizeof(*in))
1497 return ERANGE;
1498 in=(struct in_addr*)buf;
1499 buf+=sizeof(*in);
1500 buflen-=sizeof(*in);
1501
1502 if (buflen < sizeof(*addr_list)*2)
1503 return ERANGE;
1504 addr_list=(struct in_addr **)buf;
1505 buf+=sizeof(*addr_list)*2;
1506 buflen-=sizeof(*addr_list)*2;
1507
1508#ifdef __UCLIBC_HAS_IPV6__
1509 if (len < sizeof(*in6))
1510 return ERANGE;
1511 in6=(struct in6_addr*)p;
1512 p+=sizeof(*in6);
1513 len-=sizeof(*in6);
1514
1515 if (len < sizeof(*addr_list6)*2)
1516 return ERANGE;
1517 addr_list6=(struct in6_addr**)p;
1518 p+=sizeof(*addr_list6)*2;
1519 len-=sizeof(*addr_list6)*2;
1520
1521 if (len < buflen) {
1522 buflen=len;
1523 buf=p;
1524 }
1525#endif /* __UCLIBC_HAS_IPV6__ */
1526
1527 if (buflen < 80)
1528 return ERANGE;
1529
1530 __open_etc_hosts(&fp);
1531 if (fp == NULL) {
1532 result=NULL;
1533 return errno;
1534 }
1535 }
1536
1537 *h_errnop=HOST_NOT_FOUND;
1538 while (fgets(buf, buflen, fp)) {
1539 if ((cp = strchr(buf, '#')))
1540 *cp = '\0';
1541 DPRINTF("Looking at: %s\n", buf);
1542 aliases = 0;
1543
1544 cp = buf;
1545 while (*cp) {
1546 while (*cp && isspace(*cp))
1547 *cp++ = '\0';
1548 if (!*cp)
1549 continue;
1550 if (aliases < (2+MAX_ALIASES))
1551 alias[aliases++] = cp;
1552 while (*cp && !isspace(*cp))
1553 cp++;
1554 }
1555 alias[aliases] = 0;
1556
1557 if (aliases < 2)
1558 continue; /* syntax error really */
1559
1560 if (action==GETHOSTENT) {
1561 /* Return whatever the next entry happens to be. */
1562 break;
1563 } else if (action==GET_HOSTS_BYADDR) {
1564 if (strcmp(name, alias[0]) != 0)
1565 continue;
1566 } else {
1567 /* GET_HOSTS_BYNAME */
1568 for (i = 1; i < aliases; i++)
1569 if (strcasecmp(name, alias[i]) == 0)
1570 break;
1571 if (i >= aliases)
1572 continue;
1573 }
1574
1575 if (type == AF_INET && inet_pton(AF_INET, alias[0], in) > 0) {
1576 DPRINTF("Found INET\n");
1577 addr_list[0] = in;
1578 addr_list[1] = 0;
1579 result_buf->h_name = alias[1];
1580 result_buf->h_addrtype = AF_INET;
1581 result_buf->h_length = sizeof(*in);
1582 result_buf->h_addr_list = (char**) addr_list;
1583 result_buf->h_aliases = alias + 2;
1584 *result=result_buf;
1585 ret=NETDB_SUCCESS;
1586#ifdef __UCLIBC_HAS_IPV6__
1587 } else if (type == AF_INET6 && inet_pton(AF_INET6, alias[0], in6) > 0) {
1588 DPRINTF("Found INET6\n");
1589 addr_list6[0] = in6;
1590 addr_list6[1] = 0;
1591 result_buf->h_name = alias[1];
1592 result_buf->h_addrtype = AF_INET6;
1593 result_buf->h_length = sizeof(*in6);
1594 result_buf->h_addr_list = (char**) addr_list6;
1595 result_buf->h_aliases = alias + 2;
1596 *result=result_buf;
1597 ret=NETDB_SUCCESS;
1598#endif /* __UCLIBC_HAS_IPV6__ */
1599 } else {
1600 DPRINTF("Error\n");
1601 ret=TRY_AGAIN;
1602 break; /* bad ip address */
1603 }
1604
1605 if (action!=GETHOSTENT) {
1606 sl_fclose(FIL__, __LINE__, fp);
1607 }
1608 return ret;
1609 }
1610 if (action!=GETHOSTENT) {
1611 sl_fclose(FIL__, __LINE__, fp);
1612 }
1613 return ret;
1614}
1615
1616/*
1617 * we currently read formats not quite the same as that on normal
1618 * unix systems, we can have a list of nameservers after the keyword.
1619 */
1620int __get_hosts_byname_r(const char * name, int type,
1621 struct hostent * result_buf,
1622 char * buf, size_t buflen,
1623 struct hostent ** result,
1624 int * h_errnop)
1625{
1626 return(__read_etc_hosts_r(NULL, name, type, GET_HOSTS_BYNAME, result_buf, buf, buflen, result, h_errnop));
1627}
1628
1629static int __open_nameservers(void)
1630{
1631 FILE *fp;
1632 int i;
1633#define RESOLV_ARGS 5
1634 char szBuffer[128], *p, *argv[RESOLV_ARGS];
1635 int argc;
1636
1637 SH_MUTEX_LOCK(resolv_lock);
1638 if (__nameservers > 0) {
1639 goto the_end;
1640 }
1641
1642 if ((fp = fopen("/etc/resolv.conf", "r")) ||
1643 (fp = fopen("/etc/config/resolv.conf", "r"))) {
1644
1645 while (fgets(szBuffer, sizeof(szBuffer), fp) != NULL) {
1646
1647 for (p = szBuffer; *p && isspace(*p); p++)
1648 /* skip white space */;
1649 if (*p == '\0' || *p == '\n' || *p == '#') /* skip comments etc */
1650 continue;
1651 argc = 0;
1652 while (*p && argc < RESOLV_ARGS) {
1653 argv[argc++] = p;
1654 while (*p && !isspace(*p) && *p != '\n')
1655 p++;
1656 while (*p && (isspace(*p) || *p == '\n')) /* remove spaces */
1657 *p++ = '\0';
1658 }
1659
1660 if (strcmp(argv[0], "nameserver") == 0) {
1661 for (i = 1; i < argc && __nameservers < MAX_SERVERS; i++) {
1662 __nameserver[__nameservers++] = strdup(argv[i]);
1663 DPRINTF("adding nameserver %s\n", argv[i]);
1664 }
1665 }
1666
1667 /* domain and search are mutually exclusive, the last one wins */
1668 if (strcmp(argv[0],"domain")==0 || strcmp(argv[0],"search")==0) {
1669 while (__searchdomains > 0) {
1670 free(__searchdomain[--__searchdomains]);
1671 __searchdomain[__searchdomains] = NULL;
1672 }
1673 for (i=1; i < argc && __searchdomains < MAX_SEARCH; i++) {
1674 __searchdomain[__searchdomains++] = strdup(argv[i]);
1675 DPRINTF("adding search %s\n", argv[i]);
1676 }
1677 }
1678 }
1679 sl_fclose(FIL__, __LINE__, fp);
1680 } else {
1681 DPRINTF("failed to open %s\n", "resolv.conf");
1682 }
1683 DPRINTF("nameservers = %d\n", __nameservers);
1684 the_end:
1685 ; /* 'label at end of compound statement' */
1686 SH_MUTEX_UNLOCK(resolv_lock);
1687 /* cppcheck-suppress resourceLeak */
1688 return 0;
1689}
1690
1691static int sh_gethostbyname_r(const char * name,
1692 struct hostent * result_buf,
1693 char * buf, size_t buflen,
1694 struct hostent ** result,
1695 int * h_errnop)
1696{
1697 struct in_addr *in;
1698 struct in_addr **addr_list;
1699 unsigned char *packet;
1700 struct resolv_answer a;
1701 int i;
1702 int nest = 0;
1703 int __nameserversXX;
1704 char ** __nameserverXX;
1705
1706 __open_nameservers();
1707
1708 *result=NULL;
1709 if (!name)
1710 return EINVAL;
1711
1712 /* do /etc/hosts first */
1713 if ((i=__get_hosts_byname_r(name, AF_INET, result_buf,
1714 buf, buflen, result, h_errnop))==0)
1715 return i;
1716 switch (*h_errnop) {
1717 case HOST_NOT_FOUND:
1718 case NO_ADDRESS:
1719 break;
1720 case NETDB_INTERNAL:
1721 if (errno == ENOENT) {
1722 break;
1723 }
1724 /* else fall through */
1725 default:
1726 return i;
1727 }
1728
1729 DPRINTF("Nothing found in /etc/hosts\n");
1730
1731 *h_errnop = NETDB_INTERNAL;
1732 if (buflen < sizeof(*in))
1733 return ERANGE;
1734 in=(struct in_addr*)buf;
1735 buf+=sizeof(*in);
1736 buflen-=sizeof(*in);
1737
1738 if (buflen < sizeof(*addr_list)*2)
1739 return ERANGE;
1740 addr_list=(struct in_addr**)buf;
1741 buf+=sizeof(*addr_list)*2;
1742 buflen-=sizeof(*addr_list)*2;
1743
1744 addr_list[0] = in;
1745 addr_list[1] = 0;
1746
1747 if (buflen<256)
1748 return ERANGE;
1749 strncpy(buf, name, buflen);
1750
1751 /* First check if this is already an address */
1752 if (inet_aton(name, in)) {
1753 result_buf->h_name = buf;
1754 result_buf->h_addrtype = AF_INET;
1755 result_buf->h_length = sizeof(*in);
1756 result_buf->h_addr_list = (char **) addr_list;
1757 *result=result_buf;
1758 *h_errnop = NETDB_SUCCESS;
1759 return NETDB_SUCCESS;
1760 }
1761
1762 for (;;) {
1763
1764 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1765 __nameserversXX=__nameservers;
1766 __nameserverXX=__nameserver;
1767 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1768 i = __dns_lookup(buf, T_A, __nameserversXX, __nameserverXX, &packet, &a);
1769
1770 if (i < 0) {
1771 *h_errnop = HOST_NOT_FOUND;
1772 DPRINTF("__dns_lookup\n");
1773 return TRY_AGAIN;
1774 }
1775
1776 strncpy(buf, a.dotted, buflen);
1777 free(a.dotted);
1778
1779 if (a.atype == T_CNAME) { /* CNAME */
1780 DPRINTF("Got a CNAME in gethostbyname()\n");
1781 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
1782 free(packet);
1783
1784 if (i < 0) {
1785 *h_errnop = NO_RECOVERY;
1786 DPRINTF("__decode_dotted\n");
1787 return -1;
1788 }
1789 if (++nest > MAX_RECURSE) {
1790 *h_errnop = NO_RECOVERY;
1791 DPRINTF("recursion\n");
1792 return -1;
1793 }
1794 continue;
1795 } else if (a.atype == T_A) { /* ADDRESS */
1796 memcpy(in, a.rdata, sizeof(*in));
1797 result_buf->h_name = buf;
1798 result_buf->h_addrtype = AF_INET;
1799 result_buf->h_length = sizeof(*in);
1800 result_buf->h_addr_list = (char **) addr_list;
1801 free(packet);
1802 break;
1803 } else {
1804 free(packet);
1805 *h_errnop=HOST_NOT_FOUND;
1806 return TRY_AGAIN;
1807 }
1808 }
1809
1810 *result=result_buf;
1811 *h_errnop = NETDB_SUCCESS;
1812 return NETDB_SUCCESS;
1813}
1814
1815struct hostent * sh_gethostbyname(const char *name)
1816{
1817 static struct hostent h;
1818 static char buf[sizeof(struct in_addr) +
1819 sizeof(struct in_addr *)*2 +
1820 sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
1821 struct hostent *hp;
1822
1823 sh_gethostbyname_r(name, &h, buf, sizeof(buf), &hp, &h_errno);
1824
1825 return hp;
1826}
1827
1828static int __get_hosts_byaddr_r(const char * addr, int len, int type,
1829 struct hostent * result_buf,
1830 char * buf, size_t buflen,
1831 struct hostent ** result,
1832 int * h_errnop)
1833{
1834#ifndef __UCLIBC_HAS_IPV6__
1835 char ipaddr[INET_ADDRSTRLEN];
1836#else
1837 char ipaddr[INET6_ADDRSTRLEN];
1838#endif /* __UCLIBC_HAS_IPV6__ */
1839
1840 switch (type) {
1841 case AF_INET:
1842 if (len != sizeof(struct in_addr))
1843 return 0;
1844 break;
1845#ifdef __UCLIBC_HAS_IPV6__
1846 case AF_INET6:
1847 if (len != sizeof(struct in6_addr))
1848 return 0;
1849 break;
1850#endif /* __UCLIBC_HAS_IPV6__ */
1851 default:
1852 return 0;
1853 }
1854
1855 inet_ntop(type, addr, ipaddr, sizeof(ipaddr));
1856
1857 return(__read_etc_hosts_r(NULL, ipaddr, type, GET_HOSTS_BYADDR,
1858 result_buf, buf, buflen, result, h_errnop));
1859}
1860
1861static int sh_gethostbyaddr_r (const void *addr, socklen_t len, int type,
1862 struct hostent * result_buf,
1863 char * buf, size_t buflen,
1864 struct hostent ** result,
1865 int * h_errnop)
1866
1867{
1868 struct in_addr *in;
1869 struct in_addr **addr_list;
1870#ifdef __UCLIBC_HAS_IPV6__
1871 char *qp;
1872 size_t plen;
1873 struct in6_addr *in6;
1874 struct in6_addr **addr_list6;
1875#endif /* __UCLIBC_HAS_IPV6__ */
1876 unsigned char *packet;
1877 struct resolv_answer a;
1878 int i;
1879 int nest = 0;
1880 int __nameserversXX;
1881 char ** __nameserverXX;
1882
1883 *result=NULL;
1884 if (!addr)
1885 return EINVAL;
1886
1887 switch (type) {
1888 case AF_INET:
1889 if (len != sizeof(struct in_addr))
1890 return EINVAL;
1891 break;
1892#ifdef __UCLIBC_HAS_IPV6__
1893 case AF_INET6:
1894 if (len != sizeof(struct in6_addr))
1895 return EINVAL;
1896 break;
1897#endif /* __UCLIBC_HAS_IPV6__ */
1898 default:
1899 return EINVAL;
1900 }
1901
1902 /* do /etc/hosts first */
1903 if ((i=__get_hosts_byaddr_r(addr, len, type, result_buf,
1904 buf, buflen, result, h_errnop))==0)
1905 return i;
1906 switch (*h_errnop) {
1907 case HOST_NOT_FOUND:
1908 case NO_ADDRESS:
1909 break;
1910 default:
1911 return i;
1912 }
1913
1914 __open_nameservers();
1915
1916#ifdef __UCLIBC_HAS_IPV6__
1917 qp=buf;
1918 plen=buflen;
1919#endif /* __UCLIBC_HAS_IPV6__ */
1920
1921 *h_errnop = NETDB_INTERNAL;
1922 if (buflen < sizeof(*in))
1923 return ERANGE;
1924 in=(struct in_addr*)buf;
1925 buf+=sizeof(*in);
1926 buflen-=sizeof(*in);
1927
1928 if (buflen < sizeof(*addr_list)*2)
1929 return ERANGE;
1930 addr_list=(struct in_addr**)buf;
1931 buf+=sizeof(*addr_list)*2;
1932 buflen-=sizeof(*addr_list)*2;
1933
1934#ifdef __UCLIBC_HAS_IPV6__
1935 if (plen < sizeof(*in6))
1936 return ERANGE;
1937 in6=(struct in6_addr*)qp;
1938 qp+=sizeof(*in6);
1939 plen-=sizeof(*in6);
1940
1941 if (plen < sizeof(*addr_list6)*2)
1942 return ERANGE;
1943 addr_list6=(struct in6_addr**)qp;
1944 qp+=sizeof(*addr_list6)*2;
1945 plen-=sizeof(*addr_list6)*2;
1946
1947 if (plen < buflen) {
1948 buflen=plen;
1949 buf=qp;
1950 }
1951#endif /* __UCLIBC_HAS_IPV6__ */
1952
1953 if (buflen<256)
1954 return ERANGE;
1955
1956 if(type == AF_INET) {
1957 const unsigned char *tmp_addr = (const unsigned char *)addr;
1958
1959 memcpy(&in->s_addr, addr, len);
1960
1961 addr_list[0] = in;
1962
1963 sprintf(buf, "%u.%u.%u.%u.in-addr.arpa",
1964 tmp_addr[3], tmp_addr[2], tmp_addr[1], tmp_addr[0]);
1965#ifdef __UCLIBC_HAS_IPV6__
1966 } else {
1967 memcpy(in6->s6_addr, addr, len);
1968
1969 addr_list6[0] = in6;
1970 qp = buf;
1971
1972 for (i = len - 1; i >= 0; i--) {
1973 qp += sprintf(qp, "%x.%x.", in6->s6_addr[i] & 0xf,
1974 (in6->s6_addr[i] >> 4) & 0xf);
1975 }
1976 strcpy(qp, "ip6.int");
1977#endif /* __UCLIBC_HAS_IPV6__ */
1978 }
1979
1980 addr_list[1] = 0;
1981
1982 for (;;) {
1983
1984 SH_MUTEX_LOCK_UNSAFE(resolv_lock);
1985 __nameserversXX=__nameservers;
1986 __nameserverXX=__nameserver;
1987 SH_MUTEX_UNLOCK_UNSAFE(resolv_lock);
1988 i = __dns_lookup(buf, T_PTR, __nameserversXX, __nameserverXX, &packet, &a);
1989
1990 if (i < 0) {
1991 *h_errnop = HOST_NOT_FOUND;
1992 return TRY_AGAIN;
1993 }
1994
1995 strncpy(buf, a.dotted, buflen);
1996 free(a.dotted);
1997
1998 if (a.atype == T_CNAME) { /* CNAME */
1999 DPRINTF("Got a CNAME in gethostbyaddr()\n");
2000 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
2001 free(packet);
2002
2003 if (i < 0) {
2004 *h_errnop = NO_RECOVERY;
2005 return -1;
2006 }
2007 if (++nest > MAX_RECURSE) {
2008 *h_errnop = NO_RECOVERY;
2009 return -1;
2010 }
2011 continue;
2012 } else if (a.atype == T_PTR) { /* ADDRESS */
2013 i = __decode_dotted(packet, a.rdoffset, buf, buflen);
2014 free(packet);
2015
2016 result_buf->h_name = buf;
2017 result_buf->h_addrtype = type;
2018
2019 if(type == AF_INET) {
2020 result_buf->h_length = sizeof(*in);
2021#ifdef __UCLIBC_HAS_IPV6__
2022 } else {
2023 result_buf->h_length = sizeof(*in6);
2024#endif /* __UCLIBC_HAS_IPV6__ */
2025 }
2026
2027 result_buf->h_addr_list = (char **) addr_list;
2028 break;
2029 } else {
2030 free(packet);
2031 *h_errnop = NO_ADDRESS;
2032 return TRY_AGAIN;
2033 }
2034 }
2035
2036 *result=result_buf;
2037 *h_errnop = NETDB_SUCCESS;
2038 return NETDB_SUCCESS;
2039}
2040
2041struct hostent * sh_gethostbyaddr (const void *addr, socklen_t len, int type)
2042{
2043 static struct hostent h;
2044 static char buf[
2045#ifndef __UCLIBC_HAS_IPV6__
2046 sizeof(struct in_addr) + sizeof(struct in_addr *)*2 +
2047#else
2048 sizeof(struct in6_addr) + sizeof(struct in6_addr *)*2 +
2049#endif /* __UCLIBC_HAS_IPV6__ */
2050 sizeof(char *)*(ALIAS_DIM) + 256/*namebuffer*/ + 32/* margin */];
2051 struct hostent *hp;
2052
2053 sh_gethostbyaddr_r(addr, len, type, &h, buf, sizeof(buf), &hp, &h_errno);
2054
2055 return hp;
2056}
2057
2058/* NEED_STATIC_LIBS */
2059#else
2060
2061/* include something to avoid empty compilation unit */
2062#include <stdio.h>
2063
2064#endif
2065
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