summaryrefslogtreecommitdiff
path: root/source3/libsmb/libsmb_server.c
blob: 64eb1ea58418c32e47a7fd0dd0216c1402f4f3b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
/* 
   Unix SMB/Netbios implementation.
   SMB client library implementation
   Copyright (C) Andrew Tridgell 1998
   Copyright (C) Richard Sharpe 2000, 2002
   Copyright (C) John Terpstra 2000
   Copyright (C) Tom Jansen (Ninja ISD) 2002 
   Copyright (C) Derrell Lipman 2003-2008
   Copyright (C) Jeremy Allison 2007, 2008
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "libsmbclient.h"
#include "libsmb_internal.h"


/* 
 * Check a server for being alive and well.
 * returns 0 if the server is in shape. Returns 1 on error 
 * 
 * Also useable outside libsmbclient to enable external cache
 * to do some checks too.
 */
int
SMBC_check_server(SMBCCTX * context,
                  SMBCSRV * server) 
{
        socklen_t size;
        struct sockaddr addr;
        
        size = sizeof(addr);
        return (getpeername(server->cli->fd, &addr, &size) == -1);
}

/* 
 * Remove a server from the cached server list it's unused.
 * On success, 0 is returned. 1 is returned if the server could not be removed.
 * 
 * Also useable outside libsmbclient
 */
int
SMBC_remove_unused_server(SMBCCTX * context,
                          SMBCSRV * srv)
{
	SMBCFILE * file;
        
	/* are we being fooled ? */
	if (!context || !context->internal->initialized || !srv) {
                return 1;
        }
        
	/* Check all open files/directories for a relation with this server */
	for (file = context->internal->files; file; file = file->next) {
		if (file->srv == srv) {
			/* Still used */
			DEBUG(3, ("smbc_remove_usused_server: "
                                  "%p still used by %p.\n",
				  srv, file));
			return 1;
		}
	}
        
	DLIST_REMOVE(context->internal->servers, srv);
        
	cli_shutdown(srv->cli);
	srv->cli = NULL;
        
	DEBUG(3, ("smbc_remove_usused_server: %p removed.\n", srv));
        
	smbc_getFunctionRemoveCachedServer(context)(context, srv);
        
        SAFE_FREE(srv);
	return 0;
}

/****************************************************************
 * Call the auth_fn with fixed size (fstring) buffers.
 ***************************************************************/
void
SMBC_call_auth_fn(TALLOC_CTX *ctx,
                  SMBCCTX *context,
                  const char *server,
                  const char *share,
                  char **pp_workgroup,
                  char **pp_username,
                  char **pp_password)
{
	fstring workgroup;
	fstring username;
	fstring password;
        
	strlcpy(workgroup, *pp_workgroup, sizeof(workgroup));
	strlcpy(username, *pp_username, sizeof(username));
	strlcpy(password, *pp_password, sizeof(password));
        
        smbc_getFunctionAuthData(context)(server, share,
                                          workgroup, sizeof(workgroup),
                                          username, sizeof(username),
                                          password, sizeof(password));
        
	TALLOC_FREE(*pp_workgroup);
	TALLOC_FREE(*pp_username);
	TALLOC_FREE(*pp_password);
        
	*pp_workgroup = talloc_strdup(ctx, workgroup);
	*pp_username = talloc_strdup(ctx, username);
	*pp_password = talloc_strdup(ctx, password);
}


void
SMBC_get_auth_data(const char *server, const char *share,
                   char *workgroup_buf, int workgroup_buf_len,
                   char *username_buf, int username_buf_len,
                   char *password_buf, int password_buf_len)
{
        /* Default function just uses provided data.  Nothing to do. */
}



SMBCSRV *
SMBC_find_server(TALLOC_CTX *ctx,
                 SMBCCTX *context,
                 const char *server,
                 const char *share,
                 char **pp_workgroup,
                 char **pp_username,
                 char **pp_password)
{
        SMBCSRV *srv;
        int auth_called = 0;
        
check_server_cache:
        
	srv = smbc_getFunctionGetCachedServer(context)(context,
                                                       server, share,
                                                       *pp_workgroup,
                                                       *pp_username);
        
	if (!auth_called && !srv && (!*pp_username || !(*pp_username)[0] ||
                                     !*pp_password || !(*pp_password)[0])) {
		SMBC_call_auth_fn(ctx, context, server, share,
                                  pp_workgroup, pp_username, pp_password);
                
		if (!pp_workgroup || !pp_username || !pp_password) {
			return NULL;
		}
                
		/*
                 * However, smbc_auth_fn may have picked up info relating to
                 * an existing connection, so try for an existing connection
                 * again ...
                 */
		auth_called = 1;
		goto check_server_cache;
                
	}
        
	if (srv) {
		if (smbc_getFunctionCheckServer(context)(context, srv)) {
			/*
                         * This server is no good anymore
                         * Try to remove it and check for more possible
                         * servers in the cache
                         */
			if (smbc_getFunctionRemoveUnusedServer(context)(context,
                                                                        srv)) { 
                                /*
                                 * We could not remove the server completely,
                                 * remove it from the cache so we will not get
                                 * it again. It will be removed when the last
                                 * file/dir is closed.
                                 */
				smbc_getFunctionRemoveCachedServer(context)(context,
                                                                            srv);
			}
                        
			/*
                         * Maybe there are more cached connections to this
                         * server
                         */
			goto check_server_cache;
		}
                
		return srv;
 	}
        
        return NULL;
}

/*
 * Connect to a server, possibly on an existing connection
 *
 * Here, what we want to do is: If the server and username
 * match an existing connection, reuse that, otherwise, establish a
 * new connection.
 *
 * If we have to create a new connection, call the auth_fn to get the
 * info we need, unless the username and password were passed in.
 */

SMBCSRV *
SMBC_server(TALLOC_CTX *ctx,
            SMBCCTX *context,
            bool connect_if_not_found,
            const char *server,
            const char *share,
            char **pp_workgroup,
            char **pp_username,
            char **pp_password)
{
	SMBCSRV *srv=NULL;
	struct cli_state *c;
	struct nmb_name called, calling;
	const char *server_n = server;
	struct sockaddr_storage ss;
	int tried_reverse = 0;
        int port_try_first;
        int port_try_next;
        const char *username_used;
 	NTSTATUS status;
        
	zero_addr(&ss);
	ZERO_STRUCT(c);
        
	if (server[0] == 0) {
		errno = EPERM;
		return NULL;
	}
        
        /* Look for a cached connection */
        srv = SMBC_find_server(ctx, context, server, share,
                               pp_workgroup, pp_username, pp_password);
        
        /*
         * If we found a connection and we're only allowed one share per
         * server...
         */
        if (srv &&
            *share != '\0' &&
            smbc_getOptionOneSharePerServer(context)) {
                
                /*
                 * ... then if there's no current connection to the share,
                 * connect to it.  SMBC_find_server(), or rather the function
                 * pointed to by context->get_cached_srv_fn which
                 * was called by SMBC_find_server(), will have issued a tree
                 * disconnect if the requested share is not the same as the
                 * one that was already connected.
                 */
                if (srv->cli->cnum == (uint16) -1) {
                        /* Ensure we have accurate auth info */
			SMBC_call_auth_fn(ctx, context, server, share,
                                          pp_workgroup,
                                          pp_username,
                                          pp_password);
                        
			if (!*pp_workgroup || !*pp_username || !*pp_password) {
				errno = ENOMEM;
				cli_shutdown(srv->cli);
				srv->cli = NULL;
				smbc_getFunctionRemoveCachedServer(context)(context,
                                                                            srv);
				return NULL;
			}
                        
			/*
			 * We don't need to renegotiate encryption
			 * here as the encryption context is not per
			 * tid.
			 */
                        
			if (!cli_send_tconX(srv->cli, share, "?????",
                                            *pp_password,
                                            strlen(*pp_password)+1)) {
                                
                                errno = SMBC_errno(context, srv->cli);
                                cli_shutdown(srv->cli);
				srv->cli = NULL;
                                smbc_getFunctionRemoveCachedServer(context)(context,
                                                                            srv);
                                srv = NULL;
                        }
                        
                        /*
                         * Regenerate the dev value since it's based on both
                         * server and share
                         */
                        if (srv) {
                                srv->dev = (dev_t)(str_checksum(server) ^
                                                   str_checksum(share));
                        }
                }
        }
        
        /* If we have a connection... */
        if (srv) {
                
                /* ... then we're done here.  Give 'em what they came for. */
                return srv;
        }
        
        /* If we're not asked to connect when a connection doesn't exist... */
        if (! connect_if_not_found) {
                /* ... then we're done here. */
                return NULL;
        }
        
	if (!*pp_workgroup || !*pp_username || !*pp_password) {
		errno = ENOMEM;
		return NULL;
	}
        
	make_nmb_name(&calling, smbc_getNetbiosName(context), 0x0);
	make_nmb_name(&called , server, 0x20);
        
	DEBUG(4,("SMBC_server: server_n=[%s] server=[%s]\n", server_n, server));
        
	DEBUG(4,(" -> server_n=[%s] server=[%s]\n", server_n, server));
        
again:
        
	zero_addr(&ss);
        
	/* have to open a new connection */
	if ((c = cli_initialise()) == NULL) {
		errno = ENOMEM;
		return NULL;
	}
        
        if (smbc_getOptionUseKerberos(context)) {
		c->use_kerberos = True;
	}

        if (smbc_getOptionFallbackAfterKerberos(context)) {
		c->fallback_after_kerberos = True;
	}
        
	c->timeout = smbc_getTimeout(context);
        
        /*
         * Force use of port 139 for first try if share is $IPC, empty, or
         * null, so browse lists can work
         */
        if (share == NULL || *share == '\0' || strcmp(share, "IPC$") == 0) {
                port_try_first = 139;
                port_try_next = 445;
        } else {
                port_try_first = 445;
                port_try_next = 139;
        }
        
        c->port = port_try_first;
        
	status = cli_connect(c, server_n, &ss);
	if (!NT_STATUS_IS_OK(status)) {
                
                /* First connection attempt failed.  Try alternate port. */
                c->port = port_try_next;
                
                status = cli_connect(c, server_n, &ss);
		if (!NT_STATUS_IS_OK(status)) {
			cli_shutdown(c);
			errno = ETIMEDOUT;
			return NULL;
		}
	}
        
	if (!cli_session_request(c, &calling, &called)) {
		cli_shutdown(c);
		if (strcmp(called.name, "*SMBSERVER")) {
			make_nmb_name(&called , "*SMBSERVER", 0x20);
			goto again;
		} else {  /* Try one more time, but ensure we don't loop */
                        
			/* Only try this if server is an IP address ... */
                        
			if (is_ipaddress(server) && !tried_reverse) {
				fstring remote_name;
				struct sockaddr_storage rem_ss;
                                
				if (!interpret_string_addr(&rem_ss, server,
                                                           NI_NUMERICHOST)) {
					DEBUG(4, ("Could not convert IP address "
                                                  "%s to struct sockaddr_storage\n",
                                                  server));
					errno = ETIMEDOUT;
					return NULL;
				}
                                
				tried_reverse++; /* Yuck */
                                
				if (name_status_find("*", 0, 0,
                                                     &rem_ss, remote_name)) {
					make_nmb_name(&called,
                                                      remote_name,
                                                      0x20);
					goto again;
				}
			}
		}
		errno = ETIMEDOUT;
		return NULL;
	}
        
	DEBUG(4,(" session request ok\n"));
        
	if (!cli_negprot(c)) {
		cli_shutdown(c);
		errno = ETIMEDOUT;
		return NULL;
	}
        
        username_used = *pp_username;
        
	if (!NT_STATUS_IS_OK(cli_session_setup(c, username_used,
					       *pp_password,
                                               strlen(*pp_password),
					       *pp_password,
                                               strlen(*pp_password),
					       *pp_workgroup))) {
                
                /* Failed.  Try an anonymous login, if allowed by flags. */
                username_used = "";
                
                if (smbc_getOptionNoAutoAnonymousLogin(context) ||
                    !NT_STATUS_IS_OK(cli_session_setup(c, username_used,
                                                       *pp_password, 1,
                                                       *pp_password, 0,
                                                       *pp_workgroup))) {
                        
                        cli_shutdown(c);
                        errno = EPERM;
                        return NULL;
                }
	}
        
	DEBUG(4,(" session setup ok\n"));
        
	if (!cli_send_tconX(c, share, "?????",
			    *pp_password, strlen(*pp_password)+1)) {
		errno = SMBC_errno(context, c);
		cli_shutdown(c);
		return NULL;
	}
        
	DEBUG(4,(" tconx ok\n"));
        
	if (context->internal->smb_encryption_level) {
		/* Attempt UNIX smb encryption. */
		if (!NT_STATUS_IS_OK(cli_force_encryption(c,
                                                          username_used,
                                                          *pp_password,
                                                          *pp_workgroup))) {
                        
			/*
			 * context->smb_encryption_level == 1
			 * means don't fail if encryption can't be negotiated,
			 * == 2 means fail if encryption can't be negotiated.
			 */
                        
			DEBUG(4,(" SMB encrypt failed\n"));
                        
			if (context->internal->smb_encryption_level == 2) {
	                        cli_shutdown(c);
				errno = EPERM;
				return NULL;
			}
		}
		DEBUG(4,(" SMB encrypt ok\n"));
	}
        
	/*
	 * Ok, we have got a nice connection
	 * Let's allocate a server structure.
	 */
        
	srv = SMB_MALLOC_P(SMBCSRV);
	if (!srv) {
		errno = ENOMEM;
		goto failed;
	}
        
	ZERO_STRUCTP(srv);
	srv->cli = c;
	srv->dev = (dev_t)(str_checksum(server) ^ str_checksum(share));
        srv->no_pathinfo = False;
        srv->no_pathinfo2 = False;
        srv->no_nt_session = False;
        
	/* now add it to the cache (internal or external)  */
	/* Let the cache function set errno if it wants to */
	errno = 0;
	if (smbc_getFunctionAddCachedServer(context)(context, srv,
                                                     server, share,
                                                     *pp_workgroup,
                                                     *pp_username)) {
		int saved_errno = errno;
		DEBUG(3, (" Failed to add server to cache\n"));
		errno = saved_errno;
		if (errno == 0) {
			errno = ENOMEM;
		}
		goto failed;
	}
        
	DEBUG(2, ("Server connect ok: //%s/%s: %p\n",
		  server, share, srv));
        
	DLIST_ADD(context->internal->servers, srv);
	return srv;
        
failed:
	cli_shutdown(c);
	if (!srv) {
		return NULL;
	}
        
	SAFE_FREE(srv);
	return NULL;
}

/*
 * Connect to a server for getting/setting attributes, possibly on an existing
 * connection.  This works similarly to SMBC_server().
 */
SMBCSRV *
SMBC_attr_server(TALLOC_CTX *ctx,
                 SMBCCTX *context,
                 const char *server,
                 const char *share,
                 char **pp_workgroup,
                 char **pp_username,
                 char **pp_password)
{
        int flags;
        struct sockaddr_storage ss;
	struct cli_state *ipc_cli;
	struct rpc_pipe_client *pipe_hnd;
        NTSTATUS nt_status;
	SMBCSRV *ipc_srv=NULL;
        
        /*
         * See if we've already created this special connection.  Reference
         * our "special" share name '*IPC$', which is an impossible real share
         * name due to the leading asterisk.
         */
        ipc_srv = SMBC_find_server(ctx, context, server, "*IPC$",
                                   pp_workgroup, pp_username, pp_password);
        if (!ipc_srv) {
                
                /* We didn't find a cached connection.  Get the password */
		if (!*pp_password || (*pp_password)[0] == '\0') {
                        /* ... then retrieve it now. */
			SMBC_call_auth_fn(ctx, context, server, share,
                                          pp_workgroup,
                                          pp_username,
                                          pp_password);
			if (!*pp_workgroup || !*pp_username || !*pp_password) {
				errno = ENOMEM;
				return NULL;
			}
                }
                
                flags = 0;
                if (smbc_getOptionUseKerberos(context)) {
                        flags |= CLI_FULL_CONNECTION_USE_KERBEROS;
                }
                
                zero_addr(&ss);
                nt_status = cli_full_connection(&ipc_cli,
						global_myname(), server,
						&ss, 0, "IPC$", "?????",
						*pp_username,
						*pp_workgroup,
						*pp_password,
						flags,
						Undefined, NULL);
                if (! NT_STATUS_IS_OK(nt_status)) {
                        DEBUG(1,("cli_full_connection failed! (%s)\n",
                                 nt_errstr(nt_status)));
                        errno = ENOTSUP;
                        return NULL;
                }
                
		if (context->internal->smb_encryption_level) {
			/* Attempt UNIX smb encryption. */
			if (!NT_STATUS_IS_OK(cli_force_encryption(ipc_cli,
                                                                  *pp_username,
                                                                  *pp_password,
                                                                  *pp_workgroup))) {
                                
				/*
				 * context->smb_encryption_level ==
				 * 1 means don't fail if encryption can't be
				 * negotiated, == 2 means fail if encryption
				 * can't be negotiated.
				 */
                                
				DEBUG(4,(" SMB encrypt failed on IPC$\n"));
                                
				if (context->internal->smb_encryption_level == 2) {
		                        cli_shutdown(ipc_cli);
					errno = EPERM;
					return NULL;
				}
			}
			DEBUG(4,(" SMB encrypt ok on IPC$\n"));
		}
                
                ipc_srv = SMB_MALLOC_P(SMBCSRV);
                if (!ipc_srv) {
                        errno = ENOMEM;
                        cli_shutdown(ipc_cli);
                        return NULL;
                }
                
                ZERO_STRUCTP(ipc_srv);
                ipc_srv->cli = ipc_cli;
                
                pipe_hnd = cli_rpc_pipe_open_noauth(ipc_srv->cli,
                                                    PI_LSARPC,
                                                    &nt_status);
                if (!pipe_hnd) {
                        DEBUG(1, ("cli_nt_session_open fail!\n"));
                        errno = ENOTSUP;
                        cli_shutdown(ipc_srv->cli);
                        free(ipc_srv);
                        return NULL;
                }
                
                /*
                 * Some systems don't support
                 * SEC_RIGHTS_MAXIMUM_ALLOWED, but NT sends 0x2000000
                 * so we might as well do it too.
                 */
                
                nt_status = rpccli_lsa_open_policy(
                        pipe_hnd,
                        talloc_tos(),
                        True,
                        GENERIC_EXECUTE_ACCESS,
                        &ipc_srv->pol);
                
                if (!NT_STATUS_IS_OK(nt_status)) {
                        errno = SMBC_errno(context, ipc_srv->cli);
                        cli_shutdown(ipc_srv->cli);
                        return NULL;
                }
                
                /* now add it to the cache (internal or external) */
                
                errno = 0;      /* let cache function set errno if it likes */
                if (smbc_getFunctionAddCachedServer(context)(context, ipc_srv,
                                                             server,
                                                             "*IPC$",
                                                             *pp_workgroup,
                                                             *pp_username)) {
                        DEBUG(3, (" Failed to add server to cache\n"));
                        if (errno == 0) {
                                errno = ENOMEM;
                        }
                        cli_shutdown(ipc_srv->cli);
                        free(ipc_srv);
                        return NULL;
                }
                
                DLIST_ADD(context->internal->servers, ipc_srv);
        }
        
        return ipc_srv;
}