source: trunk/server/nsswitch/wb_common.c@ 823

Last change on this file since 823 was 745, checked in by Silvan Scherrer, 13 years ago

Samba Server: updated trunk to 3.6.0
File size: 14.1 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 "replace.h"
26#include "system/select.h"
27#include "winbind_client.h"
28
29/* Global variables. These are effectively the client state information */
30
31int winbindd_fd = -1; /* fd for winbindd socket */
32static int is_privileged = 0;
33
34/* Free a response structure */
35
36void winbindd_free_response(struct winbindd_response *response)
37{
38 /* Free any allocated extra_data */
39
40 if (response)
41 SAFE_FREE(response->extra_data.data);
42}
43
44/* Initialise a request structure */
45
46static void winbindd_init_request(struct winbindd_request *request,
47 int request_type)
48{
49 request->length = sizeof(struct winbindd_request);
50
51 request->cmd = (enum winbindd_cmd)request_type;
52 request->pid = getpid();
53
54}
55
56/* Initialise a response structure */
57
58static void init_response(struct winbindd_response *response)
59{
60 /* Initialise return value */
61
62 response->result = WINBINDD_ERROR;
63}
64
65/* Close established socket */
66
67#if HAVE_FUNCTION_ATTRIBUTE_DESTRUCTOR
68__attribute__((destructor))
69#endif
70static void winbind_close_sock(void)
71{
72 if (winbindd_fd != -1) {
73 close(winbindd_fd);
74 winbindd_fd = -1;
75 }
76}
77
78#define CONNECT_TIMEOUT 30
79
80/* Make sure socket handle isn't stdin, stdout or stderr */
81#define RECURSION_LIMIT 3
82
83static int make_nonstd_fd_internals(int fd, int limit /* Recursion limiter */)
84{
85 int new_fd;
86 if (fd >= 0 && fd <= 2) {
87#ifdef F_DUPFD
88 if ((new_fd = fcntl(fd, F_DUPFD, 3)) == -1) {
89 return -1;
90 }
91 /* Paranoia */
92 if (new_fd < 3) {
93 close(new_fd);
94 return -1;
95 }
96 close(fd);
97 return new_fd;
98#else
99 if (limit <= 0)
100 return -1;
101
102 new_fd = dup(fd);
103 if (new_fd == -1)
104 return -1;
105
106 /* use the program stack to hold our list of FDs to close */
107 new_fd = make_nonstd_fd_internals(new_fd, limit - 1);
108 close(fd);
109 return new_fd;
110#endif
111 }
112 return fd;
113}
114
115/****************************************************************************
116 Set a fd into blocking/nonblocking mode. Uses POSIX O_NONBLOCK if available,
117 else
118 if SYSV use O_NDELAY
119 if BSD use FNDELAY
120 Set close on exec also.
121****************************************************************************/
122
123static int make_safe_fd(int fd)
124{
125 int result, flags;
126 int new_fd = make_nonstd_fd_internals(fd, RECURSION_LIMIT);
127 if (new_fd == -1) {
128 close(fd);
129 return -1;
130 }
131
132 /* Socket should be nonblocking. */
133#ifdef O_NONBLOCK
134#define FLAG_TO_SET O_NONBLOCK
135#else
136#ifdef SYSV
137#define FLAG_TO_SET O_NDELAY
138#else /* BSD */
139#define FLAG_TO_SET FNDELAY
140#endif
141#endif
142
143 if ((flags = fcntl(new_fd, F_GETFL)) == -1) {
144 close(new_fd);
145 return -1;
146 }
147
148 flags |= FLAG_TO_SET;
149 if (fcntl(new_fd, F_SETFL, flags) == -1) {
150 close(new_fd);
151 return -1;
152 }
153
154#undef FLAG_TO_SET
155
156 /* Socket should be closed on exec() */
157#ifdef FD_CLOEXEC
158 result = flags = fcntl(new_fd, F_GETFD, 0);
159 if (flags >= 0) {
160 flags |= FD_CLOEXEC;
161 result = fcntl( new_fd, F_SETFD, flags );
162 }
163 if (result < 0) {
164 close(new_fd);
165 return -1;
166 }
167#endif
168 return new_fd;
169}
170
171/* Connect to winbindd socket */
172
173static int winbind_named_pipe_sock(const char *dir)
174{
175 struct sockaddr_un sunaddr;
176 struct stat st;
177 char *path = NULL;
178 int fd;
179 int wait_time;
180 int slept;
181
182 /* Check permissions on unix socket directory */
183
184 if (lstat(dir, &st) == -1) {
185 errno = ENOENT;
186 return -1;
187 }
188
189 if (!S_ISDIR(st.st_mode) ||
190 (st.st_uid != 0 && st.st_uid != geteuid())) {
191 errno = ENOENT;
192 return -1;
193 }
194
195 /* Connect to socket */
196
197 if (asprintf(&path, "%s/%s", dir, WINBINDD_SOCKET_NAME) < 0) {
198 return -1;
199 }
200
201 ZERO_STRUCT(sunaddr);
202 sunaddr.sun_family = AF_UNIX;
203 strncpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path) - 1);
204
205 /* If socket file doesn't exist, don't bother trying to connect
206 with retry. This is an attempt to make the system usable when
207 the winbindd daemon is not running. */
208
209 if (lstat(path, &st) == -1) {
210 errno = ENOENT;
211 SAFE_FREE(path);
212 return -1;
213 }
214
215 SAFE_FREE(path);
216 /* Check permissions on unix socket file */
217
218 if (!S_ISSOCK(st.st_mode) ||
219 (st.st_uid != 0 && st.st_uid != geteuid())) {
220 errno = ENOENT;
221 return -1;
222 }
223
224 /* Connect to socket */
225
226 if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
227 return -1;
228 }
229
230 /* Set socket non-blocking and close on exec. */
231
232 if ((fd = make_safe_fd( fd)) == -1) {
233 return fd;
234 }
235
236 for (wait_time = 0; connect(fd, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1;
237 wait_time += slept) {
238 struct pollfd pfd;
239 int ret;
240 int connect_errno = 0;
241 socklen_t errnosize;
242
243 if (wait_time >= CONNECT_TIMEOUT)
244 goto error_out;
245
246 switch (errno) {
247 case EINPROGRESS:
248 pfd.fd = fd;
249 pfd.events = POLLOUT;
250
251 ret = poll(&pfd, 1, (CONNECT_TIMEOUT - wait_time) * 1000);
252
253 if (ret > 0) {
254 errnosize = sizeof(connect_errno);
255
256 ret = getsockopt(fd, SOL_SOCKET,
257 SO_ERROR, &connect_errno, &errnosize);
258
259 if (ret >= 0 && connect_errno == 0) {
260 /* Connect succeed */
261 goto out;
262 }
263 }
264
265 slept = CONNECT_TIMEOUT;
266 break;
267 case EAGAIN:
268 slept = rand() % 3 + 1;
269 sleep(slept);
270 break;
271 default:
272 goto error_out;
273 }
274
275 }
276
277 out:
278
279 return fd;
280
281 error_out:
282
283 close(fd);
284 return -1;
285}
286
287static const char *winbindd_socket_dir(void)
288{
289#ifdef SOCKET_WRAPPER
290 const char *env_dir;
291
292 env_dir = getenv(WINBINDD_SOCKET_DIR_ENVVAR);
293 if (env_dir) {
294 return env_dir;
295 }
296#endif
297
298 return WINBINDD_SOCKET_DIR;
299}
300
301/* Connect to winbindd socket */
302
303static int winbind_open_pipe_sock(int recursing, int need_priv)
304{
305#ifdef HAVE_UNIXSOCKET
306 static pid_t our_pid;
307 struct winbindd_request request;
308 struct winbindd_response response;
309 ZERO_STRUCT(request);
310 ZERO_STRUCT(response);
311
312 if (our_pid != getpid()) {
313 winbind_close_sock();
314 our_pid = getpid();
315 }
316
317 if ((need_priv != 0) && (is_privileged == 0)) {
318 winbind_close_sock();
319 }
320
321 if (winbindd_fd != -1) {
322 return winbindd_fd;
323 }
324
325 if (recursing) {
326 return -1;
327 }
328
329 if ((winbindd_fd = winbind_named_pipe_sock(winbindd_socket_dir())) == -1) {
330 return -1;
331 }
332
333 is_privileged = 0;
334
335 /* version-check the socket */
336
337 request.wb_flags = WBFLAG_RECURSE;
338 if ((winbindd_request_response(WINBINDD_INTERFACE_VERSION, &request, &response) != NSS_STATUS_SUCCESS) || (response.data.interface_version != WINBIND_INTERFACE_VERSION)) {
339 winbind_close_sock();
340 return -1;
341 }
342
343 /* try and get priv pipe */
344
345 request.wb_flags = WBFLAG_RECURSE;
346 if (winbindd_request_response(WINBINDD_PRIV_PIPE_DIR, &request, &response) == NSS_STATUS_SUCCESS) {
347 int fd;
348 if ((fd = winbind_named_pipe_sock((char *)response.extra_data.data)) != -1) {
349 close(winbindd_fd);
350 winbindd_fd = fd;
351 is_privileged = 1;
352 }
353 }
354
355 if ((need_priv != 0) && (is_privileged == 0)) {
356 return -1;
357 }
358
359 SAFE_FREE(response.extra_data.data);
360
361 return winbindd_fd;
362#else
363 return -1;
364#endif /* HAVE_UNIXSOCKET */
365}
366
367/* Write data to winbindd socket */
368
369static int winbind_write_sock(void *buffer, int count, int recursing,
370 int need_priv)
371{
372 int result, nwritten;
373
374 /* Open connection to winbind daemon */
375
376 restart:
377
378 if (winbind_open_pipe_sock(recursing, need_priv) == -1) {
379 errno = ENOENT;
380 return -1;
381 }
382
383 /* Write data to socket */
384
385 nwritten = 0;
386
387 while(nwritten < count) {
388 struct pollfd pfd;
389 int ret;
390
391 /* Catch pipe close on other end by checking if a read()
392 call would not block by calling poll(). */
393
394 pfd.fd = winbindd_fd;
395 pfd.events = POLLIN|POLLHUP;
396
397 ret = poll(&pfd, 1, 0);
398 if (ret == -1) {
399 winbind_close_sock();
400 return -1; /* poll error */
401 }
402
403 /* Write should be OK if fd not available for reading */
404
405 if ((ret == 1) && (pfd.revents & (POLLIN|POLLHUP|POLLERR))) {
406
407 /* Pipe has closed on remote end */
408
409 winbind_close_sock();
410 goto restart;
411 }
412
413 /* Do the write */
414
415 result = write(winbindd_fd,
416 (char *)buffer + nwritten,
417 count - nwritten);
418
419 if ((result == -1) || (result == 0)) {
420
421 /* Write failed */
422
423 winbind_close_sock();
424 return -1;
425 }
426
427 nwritten += result;
428 }
429
430 return nwritten;
431}
432
433/* Read data from winbindd socket */
434
435static int winbind_read_sock(void *buffer, int count)
436{
437 int nread = 0;
438 int total_time = 0;
439
440 if (winbindd_fd == -1) {
441 return -1;
442 }
443
444 /* Read data from socket */
445 while(nread < count) {
446 struct pollfd pfd;
447 int ret;
448
449 /* Catch pipe close on other end by checking if a read()
450 call would not block by calling poll(). */
451
452 pfd.fd = winbindd_fd;
453 pfd.events = POLLIN|POLLHUP;
454
455 /* Wait for 5 seconds for a reply. May need to parameterise this... */
456
457 ret = poll(&pfd, 1, 5000);
458 if (ret == -1) {
459 winbind_close_sock();
460 return -1; /* poll error */
461 }
462
463 if (ret == 0) {
464 /* Not ready for read yet... */
465 if (total_time >= 30) {
466 /* Timeout */
467 winbind_close_sock();
468 return -1;
469 }
470 total_time += 5;
471 continue;
472 }
473
474 if ((ret == 1) && (pfd.revents & (POLLIN|POLLHUP|POLLERR))) {
475
476 /* Do the Read */
477
478 int result = read(winbindd_fd, (char *)buffer + nread,
479 count - nread);
480
481 if ((result == -1) || (result == 0)) {
482
483 /* Read failed. I think the only useful thing we
484 can do here is just return -1 and fail since the
485 transaction has failed half way through. */
486
487 winbind_close_sock();
488 return -1;
489 }
490
491 nread += result;
492
493 }
494 }
495
496 return nread;
497}
498
499/* Read reply */
500
501static int winbindd_read_reply(struct winbindd_response *response)
502{
503 int result1, result2 = 0;
504
505 if (!response) {
506 return -1;
507 }
508
509 /* Read fixed length response */
510
511 result1 = winbind_read_sock(response,
512 sizeof(struct winbindd_response));
513 if (result1 == -1) {
514 return -1;
515 }
516
517 if (response->length < sizeof(struct winbindd_response)) {
518 return -1;
519 }
520
521 /* We actually send the pointer value of the extra_data field from
522 the server. This has no meaning in the client's address space
523 so we clear it out. */
524
525 response->extra_data.data = NULL;
526
527 /* Read variable length response */
528
529 if (response->length > sizeof(struct winbindd_response)) {
530 int extra_data_len = response->length -
531 sizeof(struct winbindd_response);
532
533 /* Mallocate memory for extra data */
534
535 if (!(response->extra_data.data = malloc(extra_data_len))) {
536 return -1;
537 }
538
539 result2 = winbind_read_sock(response->extra_data.data,
540 extra_data_len);
541 if (result2 == -1) {
542 winbindd_free_response(response);
543 return -1;
544 }
545 }
546
547 /* Return total amount of data read */
548
549 return result1 + result2;
550}
551
552/*
553 * send simple types of requests
554 */
555
556NSS_STATUS winbindd_send_request(int req_type, int need_priv,
557 struct winbindd_request *request)
558{
559 struct winbindd_request lrequest;
560
561 /* Check for our tricky environment variable */
562
563 if (winbind_env_set()) {
564 return NSS_STATUS_NOTFOUND;
565 }
566
567 if (!request) {
568 ZERO_STRUCT(lrequest);
569 request = &lrequest;
570 }
571
572 /* Fill in request and send down pipe */
573
574 winbindd_init_request(request, req_type);
575
576 if (winbind_write_sock(request, sizeof(*request),
577 request->wb_flags & WBFLAG_RECURSE,
578 need_priv) == -1)
579 {
580 /* Set ENOENT for consistency. Required by some apps */
581 errno = ENOENT;
582
583 return NSS_STATUS_UNAVAIL;
584 }
585
586 if ((request->extra_len != 0) &&
587 (winbind_write_sock(request->extra_data.data,
588 request->extra_len,
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 return NSS_STATUS_SUCCESS;
599}
600
601/*
602 * Get results from winbindd request
603 */
604
605NSS_STATUS winbindd_get_response(struct winbindd_response *response)
606{
607 struct winbindd_response lresponse;
608
609 if (!response) {
610 ZERO_STRUCT(lresponse);
611 response = &lresponse;
612 }
613
614 init_response(response);
615
616 /* Wait for reply */
617 if (winbindd_read_reply(response) == -1) {
618 /* Set ENOENT for consistency. Required by some apps */
619 errno = ENOENT;
620
621 return NSS_STATUS_UNAVAIL;
622 }
623
624 /* Throw away extra data if client didn't request it */
625 if (response == &lresponse) {
626 winbindd_free_response(response);
627 }
628
629 /* Copy reply data from socket */
630 if (response->result != WINBINDD_OK) {
631 return NSS_STATUS_NOTFOUND;
632 }
633
634 return NSS_STATUS_SUCCESS;
635}
636
637/* Handle simple types of requests */
638
639NSS_STATUS winbindd_request_response(int req_type,
640 struct winbindd_request *request,
641 struct winbindd_response *response)
642{
643 NSS_STATUS status = NSS_STATUS_UNAVAIL;
644 int count = 0;
645
646 while ((status == NSS_STATUS_UNAVAIL) && (count < 10)) {
647 status = winbindd_send_request(req_type, 0, request);
648 if (status != NSS_STATUS_SUCCESS)
649 return(status);
650 status = winbindd_get_response(response);
651 count += 1;
652 }
653
654 return status;
655}
656
657NSS_STATUS winbindd_priv_request_response(int req_type,
658 struct winbindd_request *request,
659 struct winbindd_response *response)
660{
661 NSS_STATUS status = NSS_STATUS_UNAVAIL;
662 int count = 0;
663
664 while ((status == NSS_STATUS_UNAVAIL) && (count < 10)) {
665 status = winbindd_send_request(req_type, 1, request);
666 if (status != NSS_STATUS_SUCCESS)
667 return(status);
668 status = winbindd_get_response(response);
669 count += 1;
670 }
671
672 return status;
673}
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