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