source: branches/samba-3.3.x/source/nsswitch/wb_common.c

Last change on this file was 578, checked in by Herwig Bauernfeind, 14 years ago

Update Samba 3.3 to 3.3.15 (security update)
File size: 15.1 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3
4 winbind client common code
5
6 Copyright (C) Tim Potter 2000
7 Copyright (C) Andrew Tridgell 2000
8 Copyright (C) Andrew Bartlett 2002
9
10
11 This library is free software; you can redistribute it and/or
12 modify it under the terms of the GNU Lesser General Public
13 License as published by the Free Software Foundation; either
14 version 3 of the License, or (at your option) any later version.
15
16 This library is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 Library General Public License for more details.
20
21 You should have received a copy of the GNU Lesser General Public License
22 along with this program. If not, see <http://www.gnu.org/licenses/>.
23*/
24
25#include "winbind_client.h"
26
27/* Global variables. These are effectively the client state information */
28
29int winbindd_fd = -1; /* fd for winbindd socket */
30static int is_privileged = 0;
31
32/* Free a response structure */
33
34void winbindd_free_response(struct winbindd_response *response)
35{
36 /* Free any allocated extra_data */
37
38 if (response)
39 SAFE_FREE(response->extra_data.data);
40}
41
42/* Initialise a request structure */
43
44void winbindd_init_request(struct winbindd_request *request, int request_type)
45{
46 request->length = sizeof(struct winbindd_request);
47
48 request->cmd = (enum winbindd_cmd)request_type;
49 request->pid = getpid();
50
51}
52
53/* Initialise a response structure */
54
55static void init_response(struct winbindd_response *response)
56{
57 /* Initialise return value */
58
59 response->result = WINBINDD_ERROR;
60}
61
62/* Close established socket */
63
64void winbind_close_sock(void)
65{
66 if (winbindd_fd != -1) {
67 close(winbindd_fd);
68 winbindd_fd = -1;
69 }
70}
71
72#define CONNECT_TIMEOUT 30
73
74/* Make sure socket handle isn't stdin, stdout or stderr */
75#define RECURSION_LIMIT 3
76
77static int make_nonstd_fd_internals(int fd, int limit /* Recursion limiter */)
78{
79 int new_fd;
80 if (fd >= 0 && fd <= 2) {
81#ifdef F_DUPFD
82 if ((new_fd = fcntl(fd, F_DUPFD, 3)) == -1) {
83 return -1;
84 }
85 /* Paranoia */
86 if (new_fd < 3) {
87 close(new_fd);
88 return -1;
89 }
90 close(fd);
91 return new_fd;
92#else
93 if (limit <= 0)
94 return -1;
95
96 new_fd = dup(fd);
97 if (new_fd == -1)
98 return -1;
99
100 /* use the program stack to hold our list of FDs to close */
101 new_fd = make_nonstd_fd_internals(new_fd, limit - 1);
102 close(fd);
103 return new_fd;
104#endif
105 }
106 return fd;
107}
108
109/****************************************************************************
110 Set a fd into blocking/nonblocking mode. Uses POSIX O_NONBLOCK if available,
111 else
112 if SYSV use O_NDELAY
113 if BSD use FNDELAY
114 Set close on exec also.
115****************************************************************************/
116
117static int make_safe_fd(int fd)
118{
119 int result, flags;
120 int new_fd = make_nonstd_fd_internals(fd, RECURSION_LIMIT);
121 if (new_fd == -1) {
122 close(fd);
123 return -1;
124 }
125
126 /* Socket should be nonblocking. */
127#ifdef O_NONBLOCK
128#define FLAG_TO_SET O_NONBLOCK
129#else
130#ifdef SYSV
131#define FLAG_TO_SET O_NDELAY
132#else /* BSD */
133#define FLAG_TO_SET FNDELAY
134#endif
135#endif
136
137 if ((flags = fcntl(new_fd, F_GETFL)) == -1) {
138 close(new_fd);
139 return -1;
140 }
141
142 flags |= FLAG_TO_SET;
143 if (fcntl(new_fd, F_SETFL, flags) == -1) {
144 close(new_fd);
145 return -1;
146 }
147
148#undef FLAG_TO_SET
149
150 /* Socket should be closed on exec() */
151#ifdef FD_CLOEXEC
152 result = flags = fcntl(new_fd, F_GETFD, 0);
153 if (flags >= 0) {
154 flags |= FD_CLOEXEC;
155 result = fcntl( new_fd, F_SETFD, flags );
156 }
157 if (result < 0) {
158 close(new_fd);
159 return -1;
160 }
161#endif
162 return new_fd;
163}
164
165/* Connect to winbindd socket */
166
167static int winbind_named_pipe_sock(const char *dir)
168{
169 struct sockaddr_un sunaddr;
170 struct stat st;
171 char *path = NULL;
172 int fd;
173 int wait_time;
174 int slept;
175
176 /* Check permissions on unix socket directory */
177
178 if (lstat(dir, &st) == -1) {
179 errno = ENOENT;
180 return -1;
181 }
182
183 if (!S_ISDIR(st.st_mode) ||
184 (st.st_uid != 0 && st.st_uid != geteuid())) {
185 errno = ENOENT;
186 return -1;
187 }
188
189 /* Connect to socket */
190
191 if (asprintf(&path, "%s/%s", dir, WINBINDD_SOCKET_NAME) < 0) {
192 return -1;
193 }
194
195 ZERO_STRUCT(sunaddr);
196 sunaddr.sun_family = AF_UNIX;
197 strncpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path) - 1);
198
199 /* If socket file doesn't exist, don't bother trying to connect
200 with retry. This is an attempt to make the system usable when
201 the winbindd daemon is not running. */
202
203 if (lstat(path, &st) == -1) {
204 errno = ENOENT;
205 SAFE_FREE(path);
206 return -1;
207 }
208
209 SAFE_FREE(path);
210 /* Check permissions on unix socket file */
211
212 if (!S_ISSOCK(st.st_mode) ||
213 (st.st_uid != 0 && st.st_uid != geteuid())) {
214 errno = ENOENT;
215 return -1;
216 }
217
218 /* Connect to socket */
219
220 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
221 return -1;
222 }
223
224 /* Set socket non-blocking and close on exec. */
225
226 if ((fd = make_safe_fd( fd)) == -1) {
227 return fd;
228 }
229
230 for (wait_time = 0; connect(fd, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1;
231 wait_time += slept) {
232 struct timeval tv;
233 fd_set w_fds;
234 int ret;
235 int connect_errno = 0;
236 socklen_t errnosize;
237
238 if (wait_time >= CONNECT_TIMEOUT)
239 goto error_out;
240
241 switch (errno) {
242 case EINPROGRESS:
243
244 if (fd < 0 || fd >= FD_SETSIZE) {
245 errno = EBADF;
246 goto error_out;
247 }
248
249 FD_ZERO(&w_fds);
250 FD_SET(fd, &w_fds);
251 tv.tv_sec = CONNECT_TIMEOUT - wait_time;
252 tv.tv_usec = 0;
253
254 ret = select(fd + 1, NULL, &w_fds, NULL, &tv);
255
256 if (ret > 0) {
257 errnosize = sizeof(connect_errno);
258
259 ret = getsockopt(fd, SOL_SOCKET,
260 SO_ERROR, &connect_errno, &errnosize);
261
262 if (ret >= 0 && connect_errno == 0) {
263 /* Connect succeed */
264 goto out;
265 }
266 }
267
268 slept = CONNECT_TIMEOUT;
269 break;
270 case EAGAIN:
271 slept = rand() % 3 + 1;
272 sleep(slept);
273 break;
274 default:
275 goto error_out;
276 }
277
278 }
279
280 out:
281
282 return fd;
283
284 error_out:
285
286 close(fd);
287 return -1;
288}
289
290static const char *winbindd_socket_dir(void)
291{
292#ifdef SOCKET_WRAPPER
293 const char *env_dir;
294
295 env_dir = getenv(WINBINDD_SOCKET_DIR_ENVVAR);
296 if (env_dir) {
297 return env_dir;
298 }
299#endif
300
301 return WINBINDD_SOCKET_DIR;
302}
303
304/* Connect to winbindd socket */
305
306static int winbind_open_pipe_sock(int recursing, int need_priv)
307{
308#ifdef HAVE_UNIXSOCKET
309 static pid_t our_pid;
310 struct winbindd_request request;
311 struct winbindd_response response;
312 ZERO_STRUCT(request);
313 ZERO_STRUCT(response);
314
315 if (our_pid != getpid()) {
316 winbind_close_sock();
317 our_pid = getpid();
318 }
319
320 if ((need_priv != 0) && (is_privileged == 0)) {
321 winbind_close_sock();
322 }
323
324 if (winbindd_fd != -1) {
325 return winbindd_fd;
326 }
327
328 if (recursing) {
329 return -1;
330 }
331
332 if ((winbindd_fd = winbind_named_pipe_sock(winbindd_socket_dir())) == -1) {
333 return -1;
334 }
335
336 is_privileged = 0;
337
338 /* version-check the socket */
339
340 request.wb_flags = WBFLAG_RECURSE;
341 if ((winbindd_request_response(WINBINDD_INTERFACE_VERSION, &request, &response) != NSS_STATUS_SUCCESS) || (response.data.interface_version != WINBIND_INTERFACE_VERSION)) {
342 winbind_close_sock();
343 return -1;
344 }
345
346 /* try and get priv pipe */
347
348 request.wb_flags = WBFLAG_RECURSE;
349 if (winbindd_request_response(WINBINDD_PRIV_PIPE_DIR, &request, &response) == NSS_STATUS_SUCCESS) {
350 int fd;
351 if ((fd = winbind_named_pipe_sock((char *)response.extra_data.data)) != -1) {
352 close(winbindd_fd);
353 winbindd_fd = fd;
354 is_privileged = 1;
355 }
356 }
357
358 if ((need_priv != 0) && (is_privileged == 0)) {
359 return -1;
360 }
361
362 SAFE_FREE(response.extra_data.data);
363
364 return winbindd_fd;
365#else
366 return -1;
367#endif /* HAVE_UNIXSOCKET */
368}
369
370/* Write data to winbindd socket */
371
372int winbind_write_sock(void *buffer, int count, int recursing, int need_priv)
373{
374 int result, nwritten;
375
376 /* Open connection to winbind daemon */
377
378 restart:
379
380 if (winbind_open_pipe_sock(recursing, need_priv) == -1) {
381 errno = ENOENT;
382 return -1;
383 }
384
385 /* Write data to socket */
386
387 nwritten = 0;
388
389 while(nwritten < count) {
390 struct timeval tv;
391 fd_set r_fds;
392
393 if (winbindd_fd < 0 || winbindd_fd >= FD_SETSIZE) {
394 errno = EBADF;
395 winbind_close_sock();
396 return -1;
397 }
398
399 /* Catch pipe close on other end by checking if a read()
400 call would not block by calling select(). */
401
402 FD_ZERO(&r_fds);
403 FD_SET(winbindd_fd, &r_fds);
404 ZERO_STRUCT(tv);
405
406 if (select(winbindd_fd + 1, &r_fds, NULL, NULL, &tv) == -1) {
407 winbind_close_sock();
408 return -1; /* Select error */
409 }
410
411 /* Write should be OK if fd not available for reading */
412
413 if (!FD_ISSET(winbindd_fd, &r_fds)) {
414
415 /* Do the write */
416
417 result = write(winbindd_fd,
418 (char *)buffer + nwritten,
419 count - nwritten);
420
421 if ((result == -1) || (result == 0)) {
422
423 /* Write failed */
424
425 winbind_close_sock();
426 return -1;
427 }
428
429 nwritten += result;
430
431 } else {
432
433 /* Pipe has closed on remote end */
434
435 winbind_close_sock();
436 goto restart;
437 }
438 }
439
440 return nwritten;
441}
442
443/* Read data from winbindd socket */
444
445int winbind_read_sock(void *buffer, int count)
446{
447 int nread = 0;
448 int total_time = 0, selret;
449
450 if (winbindd_fd == -1) {
451 return -1;
452 }
453
454 /* Read data from socket */
455 while(nread < count) {
456 struct timeval tv;
457 fd_set r_fds;
458
459 if (winbindd_fd < 0 || winbindd_fd >= FD_SETSIZE) {
460 errno = EBADF;
461 winbind_close_sock();
462 return -1;
463 }
464
465 /* Catch pipe close on other end by checking if a read()
466 call would not block by calling select(). */
467
468 FD_ZERO(&r_fds);
469 FD_SET(winbindd_fd, &r_fds);
470 ZERO_STRUCT(tv);
471 /* Wait for 5 seconds for a reply. May need to parameterise this... */
472 tv.tv_sec = 5;
473
474 if ((selret = select(winbindd_fd + 1, &r_fds, NULL, NULL, &tv)) == -1) {
475 winbind_close_sock();
476 return -1; /* Select error */
477 }
478
479 if (selret == 0) {
480 /* Not ready for read yet... */
481 if (total_time >= 30) {
482 /* Timeout */
483 winbind_close_sock();
484 return -1;
485 }
486 total_time += 5;
487 continue;
488 }
489
490 if (FD_ISSET(winbindd_fd, &r_fds)) {
491
492 /* Do the Read */
493
494 int result = read(winbindd_fd, (char *)buffer + nread,
495 count - nread);
496
497 if ((result == -1) || (result == 0)) {
498
499 /* Read failed. I think the only useful thing we
500 can do here is just return -1 and fail since the
501 transaction has failed half way through. */
502
503 winbind_close_sock();
504 return -1;
505 }
506
507 nread += result;
508
509 }
510 }
511
512 return nread;
513}
514
515/* Read reply */
516
517int winbindd_read_reply(struct winbindd_response *response)
518{
519 int result1, result2 = 0;
520
521 if (!response) {
522 return -1;
523 }
524
525 /* Read fixed length response */
526
527 result1 = winbind_read_sock(response,
528 sizeof(struct winbindd_response));
529 if (result1 == -1) {
530 return -1;
531 }
532
533 /* We actually send the pointer value of the extra_data field from
534 the server. This has no meaning in the client's address space
535 so we clear it out. */
536
537 response->extra_data.data = NULL;
538
539 /* Read variable length response */
540
541 if (response->length > sizeof(struct winbindd_response)) {
542 int extra_data_len = response->length -
543 sizeof(struct winbindd_response);
544
545 /* Mallocate memory for extra data */
546
547 if (!(response->extra_data.data = malloc(extra_data_len))) {
548 return -1;
549 }
550
551 result2 = winbind_read_sock(response->extra_data.data,
552 extra_data_len);
553 if (result2 == -1) {
554 winbindd_free_response(response);
555 return -1;
556 }
557 }
558
559 /* Return total amount of data read */
560
561 return result1 + result2;
562}
563
564/*
565 * send simple types of requests
566 */
567
568NSS_STATUS winbindd_send_request(int req_type, int need_priv,
569 struct winbindd_request *request)
570{
571 struct winbindd_request lrequest;
572
573 /* Check for our tricky environment variable */
574
575 if (winbind_env_set()) {
576 return NSS_STATUS_NOTFOUND;
577 }
578
579 if (!request) {
580 ZERO_STRUCT(lrequest);
581 request = &lrequest;
582 }
583
584 /* Fill in request and send down pipe */
585
586 winbindd_init_request(request, req_type);
587
588 if (winbind_write_sock(request, sizeof(*request),
589 request->wb_flags & WBFLAG_RECURSE,
590 need_priv) == -1)
591 {
592 /* Set ENOENT for consistency. Required by some apps */
593 errno = ENOENT;
594
595 return NSS_STATUS_UNAVAIL;
596 }
597
598 if ((request->extra_len != 0) &&
599 (winbind_write_sock(request->extra_data.data,
600 request->extra_len,
601 request->wb_flags & WBFLAG_RECURSE,
602 need_priv) == -1))
603 {
604 /* Set ENOENT for consistency. Required by some apps */
605 errno = ENOENT;
606
607 return NSS_STATUS_UNAVAIL;
608 }
609
610 return NSS_STATUS_SUCCESS;
611}
612
613/*
614 * Get results from winbindd request
615 */
616
617NSS_STATUS winbindd_get_response(struct winbindd_response *response)
618{
619 struct winbindd_response lresponse;
620
621 if (!response) {
622 ZERO_STRUCT(lresponse);
623 response = &lresponse;
624 }
625
626 init_response(response);
627
628 /* Wait for reply */
629 if (winbindd_read_reply(response) == -1) {
630 /* Set ENOENT for consistency. Required by some apps */
631 errno = ENOENT;
632
633 return NSS_STATUS_UNAVAIL;
634 }
635
636 /* Throw away extra data if client didn't request it */
637 if (response == &lresponse) {
638 winbindd_free_response(response);
639 }
640
641 /* Copy reply data from socket */
642 if (response->result != WINBINDD_OK) {
643 return NSS_STATUS_NOTFOUND;
644 }
645
646 return NSS_STATUS_SUCCESS;
647}
648
649/* Handle simple types of requests */
650
651NSS_STATUS winbindd_request_response(int req_type,
652 struct winbindd_request *request,
653 struct winbindd_response *response)
654{
655 NSS_STATUS status = NSS_STATUS_UNAVAIL;
656 int count = 0;
657
658 while ((status == NSS_STATUS_UNAVAIL) && (count < 10)) {
659 status = winbindd_send_request(req_type, 0, request);
660 if (status != NSS_STATUS_SUCCESS)
661 return(status);
662 status = winbindd_get_response(response);
663 count += 1;
664 }
665
666 return status;
667}
668
669NSS_STATUS winbindd_priv_request_response(int req_type,
670 struct winbindd_request *request,
671 struct winbindd_response *response)
672{
673 NSS_STATUS status = NSS_STATUS_UNAVAIL;
674 int count = 0;
675
676 while ((status == NSS_STATUS_UNAVAIL) && (count < 10)) {
677 status = winbindd_send_request(req_type, 1, request);
678 if (status != NSS_STATUS_SUCCESS)
679 return(status);
680 status = winbindd_get_response(response);
681 count += 1;
682 }
683
684 return status;
685}
686
687/*************************************************************************
688 ************************************************************************/
689
690const char *nss_err_str(NSS_STATUS ret)
691{
692 switch (ret) {
693 case NSS_STATUS_TRYAGAIN:
694 return "NSS_STATUS_TRYAGAIN";
695 case NSS_STATUS_SUCCESS:
696 return "NSS_STATUS_SUCCESS";
697 case NSS_STATUS_NOTFOUND:
698 return "NSS_STATUS_NOTFOUND";
699 case NSS_STATUS_UNAVAIL:
700 return "NSS_STATUS_UNAVAIL";
701#ifdef NSS_STATUS_RETURN
702 case NSS_STATUS_RETURN:
703 return "NSS_STATUS_RETURN";
704#endif
705 default:
706 return "UNKNOWN RETURN CODE!!!!!!!";
707 }
708}
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