source: branches/samba-3.3.x/source/smbd/vfs.c@ 621

Last change on this file since 621 was 432, checked in by Silvan Scherrer, 16 years ago

samba 3.3: ticket 132
File size: 25.7 KB
Line 
1/*
2 Unix SMB/Netbios implementation.
3 Version 1.9.
4 VFS initialisation and support functions
5 Copyright (C) Tim Potter 1999
6 Copyright (C) Alexander Bokovoy 2002
7 Copyright (C) James Peach 2006
8
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3 of the License, or
12 (at your option) any later version.
13
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
18
19 You should have received a copy of the GNU General Public License
20 along with this program. If not, see <http://www.gnu.org/licenses/>.
21
22 This work was sponsored by Optifacio Software Services, Inc.
23*/
24
25#include "includes.h"
26
27#undef DBGC_CLASS
28#define DBGC_CLASS DBGC_VFS
29
30static_decl_vfs;
31
32struct vfs_init_function_entry {
33 char *name;
34 const vfs_op_tuple *vfs_op_tuples;
35 struct vfs_init_function_entry *prev, *next;
36};
37
38static struct vfs_init_function_entry *backends = NULL;
39
40/****************************************************************************
41 maintain the list of available backends
42****************************************************************************/
43
44static struct vfs_init_function_entry *vfs_find_backend_entry(const char *name)
45{
46 struct vfs_init_function_entry *entry = backends;
47
48 DEBUG(10, ("vfs_find_backend_entry called for %s\n", name));
49
50 while(entry) {
51 if (strcmp(entry->name, name)==0) return entry;
52 entry = entry->next;
53 }
54
55 return NULL;
56}
57
58NTSTATUS smb_register_vfs(int version, const char *name, const vfs_op_tuple *vfs_op_tuples)
59{
60 struct vfs_init_function_entry *entry = backends;
61
62 if ((version != SMB_VFS_INTERFACE_VERSION)) {
63 DEBUG(0, ("Failed to register vfs module.\n"
64 "The module was compiled against SMB_VFS_INTERFACE_VERSION %d,\n"
65 "current SMB_VFS_INTERFACE_VERSION is %d.\n"
66 "Please recompile against the current Samba Version!\n",
67 version, SMB_VFS_INTERFACE_VERSION));
68 return NT_STATUS_OBJECT_TYPE_MISMATCH;
69 }
70
71 if (!name || !name[0] || !vfs_op_tuples) {
72 DEBUG(0,("smb_register_vfs() called with NULL pointer or empty name!\n"));
73 return NT_STATUS_INVALID_PARAMETER;
74 }
75
76 if (vfs_find_backend_entry(name)) {
77 DEBUG(0,("VFS module %s already loaded!\n", name));
78 return NT_STATUS_OBJECT_NAME_COLLISION;
79 }
80
81 entry = SMB_XMALLOC_P(struct vfs_init_function_entry);
82 entry->name = smb_xstrdup(name);
83 entry->vfs_op_tuples = vfs_op_tuples;
84
85 DLIST_ADD(backends, entry);
86 DEBUG(5, ("Successfully added vfs backend '%s'\n", name));
87 return NT_STATUS_OK;
88}
89
90/****************************************************************************
91 initialise default vfs hooks
92****************************************************************************/
93
94static void vfs_init_default(connection_struct *conn)
95{
96 DEBUG(3, ("Initialising default vfs hooks\n"));
97 vfs_init_custom(conn, DEFAULT_VFS_MODULE_NAME);
98}
99
100/****************************************************************************
101 initialise custom vfs hooks
102 ****************************************************************************/
103
104static inline void vfs_set_operation(struct vfs_ops * vfs, vfs_op_type which,
105 struct vfs_handle_struct * handle, void * op)
106{
107 ((struct vfs_handle_struct **)&vfs->handles)[which] = handle;
108 ((void **)(void *)&vfs->ops)[which] = op;
109}
110
111bool vfs_init_custom(connection_struct *conn, const char *vfs_object)
112{
113 const vfs_op_tuple *ops;
114 char *module_path = NULL;
115 char *module_name = NULL;
116 char *module_param = NULL, *p;
117 int i;
118 vfs_handle_struct *handle;
119 const struct vfs_init_function_entry *entry;
120
121 if (!conn||!vfs_object||!vfs_object[0]) {
122 DEBUG(0,("vfs_init_custon() called with NULL pointer or emtpy vfs_object!\n"));
123 return False;
124 }
125
126 if(!backends) {
127 static_init_vfs;
128 }
129
130 DEBUG(3, ("Initialising custom vfs hooks from [%s]\n", vfs_object));
131
132 module_path = smb_xstrdup(vfs_object);
133
134 p = strchr_m(module_path, ':');
135
136 if (p) {
137 *p = 0;
138 module_param = p+1;
139 trim_char(module_param, ' ', ' ');
140 }
141
142 trim_char(module_path, ' ', ' ');
143
144 module_name = smb_xstrdup(module_path);
145
146 if ((module_name[0] == '/') &&
147 (strcmp(module_path, DEFAULT_VFS_MODULE_NAME) != 0)) {
148
149 /*
150 * Extract the module name from the path. Just use the base
151 * name of the last path component.
152 */
153
154 SAFE_FREE(module_name);
155 module_name = smb_xstrdup(strrchr_m(module_path, '/')+1);
156
157 p = strchr_m(module_name, '.');
158
159 if (p != NULL) {
160 *p = '\0';
161 }
162 }
163
164 /* First, try to load the module with the new module system */
165 if((entry = vfs_find_backend_entry(module_name)) ||
166 (NT_STATUS_IS_OK(smb_probe_module("vfs", module_path)) &&
167 (entry = vfs_find_backend_entry(module_name)))) {
168
169 DEBUGADD(5,("Successfully loaded vfs module [%s] with the new modules system\n", vfs_object));
170
171 if ((ops = entry->vfs_op_tuples) == NULL) {
172 DEBUG(0, ("entry->vfs_op_tuples==NULL for [%s] failed\n", vfs_object));
173 goto fail;
174 }
175 } else {
176 DEBUG(0,("Can't find a vfs module [%s]\n",vfs_object));
177 goto fail;
178 }
179
180 handle = TALLOC_ZERO_P(conn, vfs_handle_struct);
181 if (!handle) {
182 DEBUG(0,("TALLOC_ZERO() failed!\n"));
183 goto fail;
184 }
185 memcpy(&handle->vfs_next, &conn->vfs, sizeof(struct vfs_ops));
186 handle->conn = conn;
187 if (module_param) {
188 handle->param = talloc_strdup(conn, module_param);
189 }
190 DLIST_ADD(conn->vfs_handles, handle);
191
192 for(i=0; ops[i].op != NULL; i++) {
193 DEBUG(5, ("Checking operation #%d (type %d, layer %d)\n", i, ops[i].type, ops[i].layer));
194 if(ops[i].layer == SMB_VFS_LAYER_OPAQUE) {
195 /* If this operation was already made opaque by different module, it
196 * will be overridden here.
197 */
198 DEBUGADD(5, ("Making operation type %d opaque [module %s]\n", ops[i].type, vfs_object));
199 vfs_set_operation(&conn->vfs_opaque, ops[i].type, handle, ops[i].op);
200 }
201 /* Change current VFS disposition*/
202 DEBUGADD(5, ("Accepting operation type %d from module %s\n", ops[i].type, vfs_object));
203 vfs_set_operation(&conn->vfs, ops[i].type, handle, ops[i].op);
204 }
205
206 SAFE_FREE(module_path);
207 SAFE_FREE(module_name);
208 return True;
209
210 fail:
211 SAFE_FREE(module_path);
212 SAFE_FREE(module_name);
213 return False;
214}
215
216/*****************************************************************
217 Allow VFS modules to extend files_struct with VFS-specific state.
218 This will be ok for small numbers of extensions, but might need to
219 be refactored if it becomes more widely used.
220******************************************************************/
221
222#define EXT_DATA_AREA(e) ((uint8 *)(e) + sizeof(struct vfs_fsp_data))
223
224void *vfs_add_fsp_extension_notype(vfs_handle_struct *handle, files_struct *fsp, size_t ext_size)
225{
226 struct vfs_fsp_data *ext;
227 void * ext_data;
228
229 /* Prevent VFS modules adding multiple extensions. */
230 if ((ext_data = vfs_fetch_fsp_extension(handle, fsp))) {
231 return ext_data;
232 }
233
234 ext = (struct vfs_fsp_data *)TALLOC_ZERO(
235 handle->conn, sizeof(struct vfs_fsp_data) + ext_size);
236 if (ext == NULL) {
237 return NULL;
238 }
239
240 ext->owner = handle;
241 ext->next = fsp->vfs_extension;
242 fsp->vfs_extension = ext;
243 return EXT_DATA_AREA(ext);
244}
245
246void vfs_remove_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
247{
248 struct vfs_fsp_data *curr;
249 struct vfs_fsp_data *prev;
250
251 for (curr = fsp->vfs_extension, prev = NULL;
252 curr;
253 prev = curr, curr = curr->next) {
254 if (curr->owner == handle) {
255 if (prev) {
256 prev->next = curr->next;
257 } else {
258 fsp->vfs_extension = curr->next;
259 }
260 TALLOC_FREE(curr);
261 return;
262 }
263 }
264}
265
266void *vfs_memctx_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
267{
268 struct vfs_fsp_data *head;
269
270 for (head = fsp->vfs_extension; head; head = head->next) {
271 if (head->owner == handle) {
272 return head;
273 }
274 }
275
276 return NULL;
277}
278
279void *vfs_fetch_fsp_extension(vfs_handle_struct *handle, files_struct *fsp)
280{
281 struct vfs_fsp_data *head;
282
283 head = (struct vfs_fsp_data *)vfs_memctx_fsp_extension(handle, fsp);
284 if (head != NULL) {
285 return EXT_DATA_AREA(head);
286 }
287
288 return NULL;
289}
290
291#undef EXT_DATA_AREA
292
293/*****************************************************************
294 Generic VFS init.
295******************************************************************/
296
297bool smbd_vfs_init(connection_struct *conn)
298{
299 const char **vfs_objects;
300 unsigned int i = 0;
301 int j = 0;
302
303 /* Normal share - initialise with disk access functions */
304 vfs_init_default(conn);
305 vfs_objects = lp_vfs_objects(SNUM(conn));
306
307 /* Override VFS functions if 'vfs object' was not specified*/
308 if (!vfs_objects || !vfs_objects[0])
309 return True;
310
311 for (i=0; vfs_objects[i] ;) {
312 i++;
313 }
314
315 for (j=i-1; j >= 0; j--) {
316 if (!vfs_init_custom(conn, vfs_objects[j])) {
317 DEBUG(0, ("smbd_vfs_init: vfs_init_custom failed for %s\n", vfs_objects[j]));
318 return False;
319 }
320 }
321 return True;
322}
323
324/*******************************************************************
325 Check if directory exists.
326********************************************************************/
327
328bool vfs_directory_exist(connection_struct *conn, const char *dname, SMB_STRUCT_STAT *st)
329{
330 SMB_STRUCT_STAT st2;
331 bool ret;
332
333 if (!st)
334 st = &st2;
335
336 if (SMB_VFS_STAT(conn,dname,st) != 0)
337 return(False);
338
339 ret = S_ISDIR(st->st_mode);
340 if(!ret)
341 errno = ENOTDIR;
342
343 return ret;
344}
345
346/*******************************************************************
347 Check if an object exists in the vfs.
348********************************************************************/
349
350bool vfs_object_exist(connection_struct *conn,const char *fname,SMB_STRUCT_STAT *sbuf)
351{
352 SMB_STRUCT_STAT st;
353
354 if (!sbuf)
355 sbuf = &st;
356
357 ZERO_STRUCTP(sbuf);
358
359 if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
360 return(False);
361 return True;
362}
363
364/*******************************************************************
365 Check if a file exists in the vfs.
366********************************************************************/
367
368bool vfs_file_exist(connection_struct *conn, const char *fname,SMB_STRUCT_STAT *sbuf)
369{
370 SMB_STRUCT_STAT st;
371
372 if (!sbuf)
373 sbuf = &st;
374
375 ZERO_STRUCTP(sbuf);
376
377 if (SMB_VFS_STAT(conn,fname,sbuf) == -1)
378 return False;
379 return(S_ISREG(sbuf->st_mode));
380}
381
382/****************************************************************************
383 Read data from fsp on the vfs. (note: EINTR re-read differs from vfs_write_data)
384****************************************************************************/
385
386ssize_t vfs_read_data(files_struct *fsp, char *buf, size_t byte_count)
387{
388 size_t total=0;
389
390 while (total < byte_count)
391 {
392 ssize_t ret = SMB_VFS_READ(fsp, buf + total,
393 byte_count - total);
394
395 if (ret == 0) return total;
396 if (ret == -1) {
397 if (errno == EINTR)
398 continue;
399 else
400 return -1;
401 }
402 total += ret;
403 }
404 return (ssize_t)total;
405}
406
407ssize_t vfs_pread_data(files_struct *fsp, char *buf,
408 size_t byte_count, SMB_OFF_T offset)
409{
410 size_t total=0;
411
412 while (total < byte_count)
413 {
414 ssize_t ret = SMB_VFS_PREAD(fsp, buf + total,
415 byte_count - total, offset + total);
416
417 if (ret == 0) return total;
418 if (ret == -1) {
419 if (errno == EINTR)
420 continue;
421 else
422 return -1;
423 }
424 total += ret;
425 }
426 return (ssize_t)total;
427}
428
429/****************************************************************************
430 Write data to a fd on the vfs.
431****************************************************************************/
432
433ssize_t vfs_write_data(struct smb_request *req,
434 files_struct *fsp,
435 const char *buffer,
436 size_t N)
437{
438 size_t total=0;
439 ssize_t ret;
440
441 if (req && req->unread_bytes) {
442 SMB_ASSERT(req->unread_bytes == N);
443 /* VFS_RECVFILE must drain the socket
444 * before returning. */
445 req->unread_bytes = 0;
446 return SMB_VFS_RECVFILE(smbd_server_fd(),
447 fsp,
448 (SMB_OFF_T)-1,
449 N);
450 }
451
452 while (total < N) {
453 ret = SMB_VFS_WRITE(fsp, buffer + total, N - total);
454
455 if (ret == -1)
456 return -1;
457 if (ret == 0)
458 return total;
459
460 total += ret;
461 }
462 return (ssize_t)total;
463}
464
465ssize_t vfs_pwrite_data(struct smb_request *req,
466 files_struct *fsp,
467 const char *buffer,
468 size_t N,
469 SMB_OFF_T offset)
470{
471 size_t total=0;
472 ssize_t ret;
473
474 if (req && req->unread_bytes) {
475 SMB_ASSERT(req->unread_bytes == N);
476 /* VFS_RECVFILE must drain the socket
477 * before returning. */
478 req->unread_bytes = 0;
479 return SMB_VFS_RECVFILE(smbd_server_fd(),
480 fsp,
481 offset,
482 N);
483 }
484
485 while (total < N) {
486 ret = SMB_VFS_PWRITE(fsp, buffer + total, N - total,
487 offset + total);
488
489 if (ret == -1)
490 return -1;
491 if (ret == 0)
492 return total;
493
494 total += ret;
495 }
496 return (ssize_t)total;
497}
498/****************************************************************************
499 An allocate file space call using the vfs interface.
500 Allocates space for a file from a filedescriptor.
501 Returns 0 on success, -1 on failure.
502****************************************************************************/
503
504int vfs_allocate_file_space(files_struct *fsp, SMB_BIG_UINT len)
505{
506 int ret;
507 SMB_STRUCT_STAT st;
508 connection_struct *conn = fsp->conn;
509 SMB_BIG_UINT space_avail;
510 SMB_BIG_UINT bsize,dfree,dsize;
511
512 release_level_2_oplocks_on_change(fsp);
513
514 /*
515 * Actually try and commit the space on disk....
516 */
517
518 DEBUG(10,("vfs_allocate_file_space: file %s, len %.0f\n", fsp->fsp_name, (double)len ));
519
520 if (((SMB_OFF_T)len) < 0) {
521 DEBUG(0,("vfs_allocate_file_space: %s negative len requested.\n", fsp->fsp_name ));
522 errno = EINVAL;
523 return -1;
524 }
525
526 ret = SMB_VFS_FSTAT(fsp, &st);
527 if (ret == -1)
528 return ret;
529
530 if (len == (SMB_BIG_UINT)st.st_size)
531 return 0;
532
533 if (len < (SMB_BIG_UINT)st.st_size) {
534 /* Shrink - use ftruncate. */
535
536 DEBUG(10,("vfs_allocate_file_space: file %s, shrink. Current size %.0f\n",
537 fsp->fsp_name, (double)st.st_size ));
538
539 flush_write_cache(fsp, SIZECHANGE_FLUSH);
540 if ((ret = SMB_VFS_FTRUNCATE(fsp, (SMB_OFF_T)len)) != -1) {
541 set_filelen_write_cache(fsp, len);
542 }
543 return ret;
544 }
545
546 /* Grow - we need to test if we have enough space. */
547
548 if (!lp_strict_allocate(SNUM(fsp->conn)))
549 return 0;
550
551 len -= st.st_size;
552 len /= 1024; /* Len is now number of 1k blocks needed. */
553 space_avail = get_dfree_info(conn,fsp->fsp_name,False,&bsize,&dfree,&dsize);
554 if (space_avail == (SMB_BIG_UINT)-1) {
555 return -1;
556 }
557
558 DEBUG(10,("vfs_allocate_file_space: file %s, grow. Current size %.0f, needed blocks = %.0f, space avail = %.0f\n",
559 fsp->fsp_name, (double)st.st_size, (double)len, (double)space_avail ));
560
561 if (len > space_avail) {
562 errno = ENOSPC;
563 return -1;
564 }
565
566 return 0;
567}
568
569/****************************************************************************
570 A vfs set_filelen call.
571 set the length of a file from a filedescriptor.
572 Returns 0 on success, -1 on failure.
573****************************************************************************/
574
575int vfs_set_filelen(files_struct *fsp, SMB_OFF_T len)
576{
577 int ret;
578
579 release_level_2_oplocks_on_change(fsp);
580 DEBUG(10,("vfs_set_filelen: ftruncate %s to len %.0f\n", fsp->fsp_name, (double)len));
581 flush_write_cache(fsp, SIZECHANGE_FLUSH);
582 if ((ret = SMB_VFS_FTRUNCATE(fsp, len)) != -1) {
583 set_filelen_write_cache(fsp, len);
584 notify_fname(fsp->conn, NOTIFY_ACTION_MODIFIED,
585 FILE_NOTIFY_CHANGE_SIZE
586 | FILE_NOTIFY_CHANGE_ATTRIBUTES,
587 fsp->fsp_name);
588 }
589
590 return ret;
591}
592
593/****************************************************************************
594 A vfs fill sparse call.
595 Writes zeros from the end of file to len, if len is greater than EOF.
596 Used only by strict_sync.
597 Returns 0 on success, -1 on failure.
598****************************************************************************/
599
600static char *sparse_buf;
601#define SPARSE_BUF_WRITE_SIZE (32*1024)
602
603int vfs_fill_sparse(files_struct *fsp, SMB_OFF_T len)
604{
605 int ret;
606 SMB_STRUCT_STAT st;
607 SMB_OFF_T offset;
608 size_t total;
609 size_t num_to_write;
610 ssize_t pwrite_ret;
611
612 release_level_2_oplocks_on_change(fsp);
613 ret = SMB_VFS_FSTAT(fsp, &st);
614 if (ret == -1) {
615 return ret;
616 }
617
618 if (len <= st.st_size) {
619 return 0;
620 }
621
622 DEBUG(10,("vfs_fill_sparse: write zeros in file %s from len %.0f to len %.0f (%.0f bytes)\n",
623 fsp->fsp_name, (double)st.st_size, (double)len, (double)(len - st.st_size)));
624
625 flush_write_cache(fsp, SIZECHANGE_FLUSH);
626
627 if (!sparse_buf) {
628 sparse_buf = SMB_CALLOC_ARRAY(char, SPARSE_BUF_WRITE_SIZE);
629 if (!sparse_buf) {
630 errno = ENOMEM;
631 return -1;
632 }
633 }
634
635 offset = st.st_size;
636 num_to_write = len - st.st_size;
637 total = 0;
638
639 while (total < num_to_write) {
640 size_t curr_write_size = MIN(SPARSE_BUF_WRITE_SIZE, (num_to_write - total));
641
642 pwrite_ret = SMB_VFS_PWRITE(fsp, sparse_buf, curr_write_size, offset + total);
643 if (pwrite_ret == -1) {
644 DEBUG(10,("vfs_fill_sparse: SMB_VFS_PWRITE for file %s failed with error %s\n",
645 fsp->fsp_name, strerror(errno) ));
646 return -1;
647 }
648 if (pwrite_ret == 0) {
649 return 0;
650 }
651
652 total += pwrite_ret;
653 }
654
655 set_filelen_write_cache(fsp, len);
656 return 0;
657}
658
659/****************************************************************************
660 Transfer some data (n bytes) between two file_struct's.
661****************************************************************************/
662
663static ssize_t vfs_read_fn(void *file, void *buf, size_t len)
664{
665 struct files_struct *fsp = (struct files_struct *)file;
666
667 return SMB_VFS_READ(fsp, buf, len);
668}
669
670static ssize_t vfs_write_fn(void *file, const void *buf, size_t len)
671{
672 struct files_struct *fsp = (struct files_struct *)file;
673
674 return SMB_VFS_WRITE(fsp, buf, len);
675}
676
677SMB_OFF_T vfs_transfer_file(files_struct *in, files_struct *out, SMB_OFF_T n)
678{
679 return transfer_file_internal((void *)in, (void *)out, n,
680 vfs_read_fn, vfs_write_fn);
681}
682
683/*******************************************************************
684 A vfs_readdir wrapper which just returns the file name.
685********************************************************************/
686
687char *vfs_readdirname(connection_struct *conn, void *p)
688{
689 SMB_STRUCT_DIRENT *ptr= NULL;
690 char *dname;
691
692 if (!p)
693 return(NULL);
694
695 ptr = SMB_VFS_READDIR(conn, (DIR *)p);
696 if (!ptr)
697 return(NULL);
698
699 dname = ptr->d_name;
700
701#ifdef NEXT2
702 if (telldir(p) < 0)
703 return(NULL);
704#endif
705
706#ifdef HAVE_BROKEN_READDIR_NAME
707 /* using /usr/ucb/cc is BAD */
708 dname = dname - 2;
709#endif
710
711 return(dname);
712}
713
714/*******************************************************************
715 A wrapper for vfs_chdir().
716********************************************************************/
717
718int vfs_ChDir(connection_struct *conn, const char *path)
719{
720 int res;
721 static char *LastDir = NULL;
722
723 if (!LastDir) {
724 LastDir = SMB_STRDUP("");
725 }
726
727 if (strcsequal(path,"."))
728 return(0);
729
730#ifdef __OS2__
731 if ((*path == '/' || *path == '\\' || (*path && path[1] == ':')) && strcsequal(LastDir,path))
732#else
733 if (*path == '/' && strcsequal(LastDir,path))
734#endif
735 return(0);
736
737 DEBUG(4,("vfs_ChDir to %s\n",path));
738
739 res = SMB_VFS_CHDIR(conn,path);
740 if (!res) {
741 SAFE_FREE(LastDir);
742 LastDir = SMB_STRDUP(path);
743 }
744 return(res);
745}
746
747/*******************************************************************
748 Return the absolute current directory path - given a UNIX pathname.
749 Note that this path is returned in DOS format, not UNIX
750 format. Note this can be called with conn == NULL.
751********************************************************************/
752
753struct getwd_cache_key {
754 SMB_DEV_T dev;
755 SMB_INO_T ino;
756};
757
758char *vfs_GetWd(TALLOC_CTX *ctx, connection_struct *conn)
759{
760 char s[PATH_MAX+1];
761 SMB_STRUCT_STAT st, st2;
762 char *result;
763 DATA_BLOB cache_value;
764 struct getwd_cache_key key;
765
766 *s = 0;
767
768 if (!lp_getwd_cache()) {
769 goto nocache;
770 }
771
772 SET_STAT_INVALID(st);
773
774 if (SMB_VFS_STAT(conn, ".",&st) == -1) {
775 /*
776 * Known to fail for root: the directory may be NFS-mounted
777 * and exported with root_squash (so has no root access).
778 */
779 DEBUG(1,("vfs_GetWd: couldn't stat \".\" error %s "
780 "(NFS problem ?)\n", strerror(errno) ));
781 goto nocache;
782 }
783
784 ZERO_STRUCT(key); /* unlikely, but possible padding */
785 key.dev = st.st_dev;
786 key.ino = st.st_ino;
787
788 if (!memcache_lookup(smbd_memcache(), GETWD_CACHE,
789 data_blob_const(&key, sizeof(key)),
790 &cache_value)) {
791 goto nocache;
792 }
793
794 SMB_ASSERT((cache_value.length > 0)
795 && (cache_value.data[cache_value.length-1] == '\0'));
796
797 if ((SMB_VFS_STAT(conn, (char *)cache_value.data, &st2) == 0)
798 && (st.st_dev == st2.st_dev) && (st.st_ino == st2.st_ino)
799 && (S_ISDIR(st.st_mode))) {
800 /*
801 * Ok, we're done
802 */
803 result = talloc_strdup(ctx, (char *)cache_value.data);
804 if (result == NULL) {
805 errno = ENOMEM;
806 }
807 return result;
808 }
809
810 nocache:
811
812 /*
813 * We don't have the information to hand so rely on traditional
814 * methods. The very slow getcwd, which spawns a process on some
815 * systems, or the not quite so bad getwd.
816 */
817
818 if (!SMB_VFS_GETWD(conn,s)) {
819 DEBUG(0, ("vfs_GetWd: SMB_VFS_GETWD call failed: %s\n",
820 strerror(errno)));
821 return NULL;
822 }
823
824 if (lp_getwd_cache() && VALID_STAT(st)) {
825 ZERO_STRUCT(key); /* unlikely, but possible padding */
826 key.dev = st.st_dev;
827 key.ino = st.st_ino;
828
829 memcache_add(smbd_memcache(), GETWD_CACHE,
830 data_blob_const(&key, sizeof(key)),
831 data_blob_const(s, strlen(s)+1));
832 }
833
834 result = talloc_strdup(ctx, s);
835 if (result == NULL) {
836 errno = ENOMEM;
837 }
838 return result;
839}
840
841/*******************************************************************
842 Reduce a file name, removing .. elements and checking that
843 it is below dir in the heirachy. This uses realpath.
844********************************************************************/
845
846NTSTATUS check_reduced_name(connection_struct *conn, const char *fname)
847{
848#ifdef REALPATH_TAKES_NULL
849 bool free_resolved_name = True;
850#else
851 char resolved_name_buf[PATH_MAX+1];
852 bool free_resolved_name = False;
853#endif
854 char *resolved_name = NULL;
855 size_t con_path_len = strlen(conn->connectpath);
856 char *p = NULL;
857
858 DEBUG(3,("reduce_name [%s] [%s]\n", fname, conn->connectpath));
859
860#ifdef REALPATH_TAKES_NULL
861 resolved_name = SMB_VFS_REALPATH(conn,fname,NULL);
862#else
863 resolved_name = SMB_VFS_REALPATH(conn,fname,resolved_name_buf);
864#endif
865
866 if (!resolved_name) {
867 switch (errno) {
868 case ENOTDIR:
869 DEBUG(3,("reduce_name: Component not a directory in getting realpath for %s\n", fname));
870 return map_nt_error_from_unix(errno);
871 case ENOENT:
872 {
873 TALLOC_CTX *ctx = talloc_tos();
874 char *tmp_fname = NULL;
875 char *last_component = NULL;
876 /* Last component didn't exist. Remove it and try and canonicalise the directory. */
877
878 tmp_fname = talloc_strdup(ctx, fname);
879 if (!tmp_fname) {
880 return NT_STATUS_NO_MEMORY;
881 }
882 p = strrchr_m(tmp_fname, '/');
883 if (p) {
884 *p++ = '\0';
885 last_component = p;
886 } else {
887 last_component = tmp_fname;
888 tmp_fname = talloc_strdup(ctx,
889 ".");
890 if (!tmp_fname) {
891 return NT_STATUS_NO_MEMORY;
892 }
893 }
894
895#ifdef REALPATH_TAKES_NULL
896 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,NULL);
897#else
898 resolved_name = SMB_VFS_REALPATH(conn,tmp_fname,resolved_name_buf);
899#endif
900 if (!resolved_name) {
901 DEBUG(3,("reduce_name: couldn't get realpath for %s\n", fname));
902 return map_nt_error_from_unix(errno);
903 }
904 tmp_fname = talloc_asprintf(ctx,
905 "%s/%s",
906 resolved_name,
907 last_component);
908 if (!tmp_fname) {
909 return NT_STATUS_NO_MEMORY;
910 }
911#ifdef REALPATH_TAKES_NULL
912 SAFE_FREE(resolved_name);
913 resolved_name = SMB_STRDUP(tmp_fname);
914 if (!resolved_name) {
915 DEBUG(0,("reduce_name: malloc fail for %s\n", tmp_fname));
916 return NT_STATUS_NO_MEMORY;
917 }
918#else
919 safe_strcpy(resolved_name_buf, tmp_fname, PATH_MAX);
920 resolved_name = resolved_name_buf;
921#endif
922 break;
923 }
924 default:
925 DEBUG(1,("reduce_name: couldn't get realpath for %s\n", fname));
926 return map_nt_error_from_unix(errno);
927 }
928 }
929
930 DEBUG(10,("reduce_name realpath [%s] -> [%s]\n", fname, resolved_name));
931
932#ifdef __OS2__
933 if (*resolved_name != '/' && *resolved_name != '\\' && (strlen(resolved_name) <= 1 || resolved_name[1] != ':')) {
934#else
935 if (*resolved_name != '/') {
936#endif
937 DEBUG(0,("reduce_name: realpath doesn't return absolute paths !\n"));
938 if (free_resolved_name) {
939 SAFE_FREE(resolved_name);
940 }
941 return NT_STATUS_OBJECT_NAME_INVALID;
942 }
943
944 /* Check for widelinks allowed. */
945 if (!lp_widelinks(SNUM(conn)) && (strncmp(conn->connectpath, resolved_name, con_path_len) != 0)) {
946 DEBUG(2, ("reduce_name: Bad access attempt: %s is a symlink outside the share path\n", fname));
947 if (free_resolved_name) {
948 SAFE_FREE(resolved_name);
949 }
950 return NT_STATUS_ACCESS_DENIED;
951 }
952
953 /* Check if we are allowing users to follow symlinks */
954 /* Patch from David Clerc <David.Clerc@cui.unige.ch>
955 University of Geneva */
956
957#ifdef S_ISLNK
958 if (!lp_symlinks(SNUM(conn))) {
959 SMB_STRUCT_STAT statbuf;
960 if ( (SMB_VFS_LSTAT(conn,fname,&statbuf) != -1) &&
961 (S_ISLNK(statbuf.st_mode)) ) {
962 if (free_resolved_name) {
963 SAFE_FREE(resolved_name);
964 }
965 DEBUG(3,("reduce_name: denied: file path name %s is a symlink\n",resolved_name));
966 return NT_STATUS_ACCESS_DENIED;
967 }
968 }
969#endif
970
971 DEBUG(3,("reduce_name: %s reduced to %s\n", fname, resolved_name));
972 if (free_resolved_name) {
973 SAFE_FREE(resolved_name);
974 }
975 return NT_STATUS_OK;
976}
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