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CVE-2022-3592 smbd: No empty path components in openat_pathref_dirfsp_nosymlink()
[Samba.git] / source3 / smbd / files.c
blob64297f187732abba19302b66e905be408e21538e
1 /*
2 Unix SMB/CIFS implementation.
3 Files[] structure handling
4 Copyright (C) Andrew Tridgell 1998
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "includes.h"
21 #include "smbd/smbd.h"
22 #include "smbd/globals.h"
23 #include "smbd/smbXsrv_open.h"
24 #include "libcli/security/security.h"
25 #include "util_tdb.h"
26 #include "lib/util/bitmap.h"
27 #include "lib/util/strv.h"
28
29 #define FILE_HANDLE_OFFSET 0x1000
30
31 static NTSTATUS fsp_attach_smb_fname(struct files_struct *fsp,
32 struct smb_filename **_smb_fname);
33
34 /**
35 * create new fsp to be used for file_new or a durable handle reconnect
36 */
37 NTSTATUS fsp_new(struct connection_struct *conn, TALLOC_CTX *mem_ctx,
38 files_struct **result)
39 {
40 NTSTATUS status = NT_STATUS_NO_MEMORY;
41 files_struct *fsp = NULL;
42 struct smbd_server_connection *sconn = conn->sconn;
43
44 fsp = talloc_zero(mem_ctx, struct files_struct);
45 if (fsp == NULL) {
46 goto fail;
47 }
48
49 /*
50 * This can't be a child of fsp because the file_handle can be ref'd
51 * when doing a dos/fcb open, which will then share the file_handle
52 * across multiple fsps.
53 */
54 fsp->fh = fd_handle_create(mem_ctx);
55 if (fsp->fh == NULL) {
56 goto fail;
57 }
58
59 fsp->fsp_flags.use_ofd_locks = !lp_smbd_force_process_locks(SNUM(conn));
60 #ifndef HAVE_OFD_LOCKS
61 fsp->fsp_flags.use_ofd_locks = false;
62 #endif
63
64 fh_set_refcount(fsp->fh, 1);
65 fsp_set_fd(fsp, -1);
66
67 fsp->fnum = FNUM_FIELD_INVALID;
68 fsp->conn = conn;
69 fsp->close_write_time = make_omit_timespec();
70
71 DLIST_ADD(sconn->files, fsp);
72 sconn->num_files += 1;
73
74 conn->num_files_open++;
75
76 DBG_INFO("allocated files structure (%u used)\n",
77 (unsigned int)sconn->num_files);
78
79 *result = fsp;
80 return NT_STATUS_OK;
81
82 fail:
83 if (fsp != NULL) {
84 TALLOC_FREE(fsp->fh);
85 }
86 TALLOC_FREE(fsp);
87
88 return status;
89 }
90
91 void fsp_set_gen_id(files_struct *fsp)
92 {
93 static uint64_t gen_id = 1;
94
95 /*
96 * A billion of 64-bit increments per second gives us
97 * more than 500 years of runtime without wrap.
98 */
99 gen_id++;
100 fh_set_gen_id(fsp->fh, gen_id);
101 }
102
103 /****************************************************************************
104 Find first available file slot.
105 ****************************************************************************/
106
107 NTSTATUS fsp_bind_smb(struct files_struct *fsp, struct smb_request *req)
108 {
109 struct smbXsrv_open *op = NULL;
110 NTTIME now;
111 NTSTATUS status;
112
113 if (req == NULL) {
114 DBG_DEBUG("INTERNAL_OPEN_ONLY, skipping smbXsrv_open\n");
115 return NT_STATUS_OK;
116 }
117
118 now = timeval_to_nttime(&fsp->open_time);
119
120 status = smbXsrv_open_create(req->xconn,
121 fsp->conn->session_info,
122 now,
123 &op);
124 if (!NT_STATUS_IS_OK(status)) {
125 return status;
126 }
127 fsp->op = op;
128 op->compat = fsp;
129 fsp->fnum = op->local_id;
130
131 fsp->mid = req->mid;
132 req->chain_fsp = fsp;
133
134 DBG_DEBUG("fsp [%s] mid [%" PRIu64"]\n",
135 fsp_str_dbg(fsp), fsp->mid);
136
137 return NT_STATUS_OK;
138 }
139
140 NTSTATUS file_new(struct smb_request *req, connection_struct *conn,
141 files_struct **result)
142 {
143 struct smbd_server_connection *sconn = conn->sconn;
144 files_struct *fsp;
145 NTSTATUS status;
146
147 status = fsp_new(conn, conn, &fsp);
148 if (!NT_STATUS_IS_OK(status)) {
149 return status;
150 }
151
152 GetTimeOfDay(&fsp->open_time);
153
154 status = fsp_bind_smb(fsp, req);
155 if (!NT_STATUS_IS_OK(status)) {
156 file_free(NULL, fsp);
157 return status;
158 }
159
160 fsp_set_gen_id(fsp);
161
162 /*
163 * Create an smb_filename with "" for the base_name. There are very
164 * few NULL checks, so make sure it's initialized with something. to
165 * be safe until an audit can be done.
166 */
167 fsp->fsp_name = synthetic_smb_fname(fsp,
168 "",
169 NULL,
170 NULL,
171 0,
172 0);
173 if (fsp->fsp_name == NULL) {
174 file_free(NULL, fsp);
175 return NT_STATUS_NO_MEMORY;
176 }
177
178 DBG_INFO("new file %s\n", fsp_fnum_dbg(fsp));
179
180 /* A new fsp invalidates the positive and
181 negative fsp_fi_cache as the new fsp is pushed
182 at the start of the list and we search from
183 a cache hit to the *end* of the list. */
184
185 ZERO_STRUCT(sconn->fsp_fi_cache);
186
187 *result = fsp;
188 return NT_STATUS_OK;
189 }
190
191 NTSTATUS create_internal_fsp(connection_struct *conn,
192 const struct smb_filename *smb_fname,
193 struct files_struct **_fsp)
194 {
195 struct files_struct *fsp = NULL;
196 NTSTATUS status;
197
198 status = file_new(NULL, conn, &fsp);
199 if (!NT_STATUS_IS_OK(status)) {
200 return status;
201 }
202
203 status = fsp_set_smb_fname(fsp, smb_fname);
204 if (!NT_STATUS_IS_OK(status)) {
205 file_free(NULL, fsp);
206 return status;
207 }
208
209 *_fsp = fsp;
210 return NT_STATUS_OK;
211 }
212
213 /*
214 * Create an internal fsp for an *existing* directory.
215 *
216 * This should only be used by callers in the VFS that need to control the
217 * opening of the directory. Otherwise use open_internal_dirfsp_at().
218 */
219 NTSTATUS create_internal_dirfsp(connection_struct *conn,
220 const struct smb_filename *smb_dname,
221 struct files_struct **_fsp)
222 {
223 struct files_struct *fsp = NULL;
224 NTSTATUS status;
225
226 status = create_internal_fsp(conn, smb_dname, &fsp);
227 if (!NT_STATUS_IS_OK(status)) {
228 return status;
229 }
230
231 fsp->access_mask = FILE_LIST_DIRECTORY;
232 fsp->fsp_flags.is_directory = true;
233 fsp->fsp_flags.is_dirfsp = true;
234
235 *_fsp = fsp;
236 return NT_STATUS_OK;
237 }
238
239 /*
240 * Open an internal fsp for an *existing* directory.
241 */
242 NTSTATUS open_internal_dirfsp(connection_struct *conn,
243 const struct smb_filename *smb_dname,
244 int _open_flags,
245 struct files_struct **_fsp)
246 {
247 struct vfs_open_how how = { .flags = _open_flags, };
248 struct files_struct *fsp = NULL;
249 NTSTATUS status;
250
251 status = create_internal_dirfsp(conn, smb_dname, &fsp);
252 if (!NT_STATUS_IS_OK(status)) {
253 return status;
254 }
255
256 #ifdef O_DIRECTORY
257 how.flags |= O_DIRECTORY;
258 #endif
259 status = fd_openat(conn->cwd_fsp, fsp->fsp_name, fsp, &how);
260 if (!NT_STATUS_IS_OK(status)) {
261 DBG_INFO("Could not open fd for %s (%s)\n",
262 smb_fname_str_dbg(smb_dname),
263 nt_errstr(status));
264 file_free(NULL, fsp);
265 return status;
266 }
267
268 status = vfs_stat_fsp(fsp);
269 if (!NT_STATUS_IS_OK(status)) {
270 file_free(NULL, fsp);
271 return status;
272 }
273
274 if (!S_ISDIR(fsp->fsp_name->st.st_ex_mode)) {
275 DBG_ERR("%s is not a directory!\n",
276 smb_fname_str_dbg(smb_dname));
277 file_free(NULL, fsp);
278 return NT_STATUS_NOT_A_DIRECTORY;
279 }
280
281 fsp->file_id = vfs_file_id_from_sbuf(conn, &fsp->fsp_name->st);
282
283 *_fsp = fsp;
284 return NT_STATUS_OK;
285 }
286
287 /*
288 * Convert a pathref dirfsp into a real fsp. No need to do any cwd
289 * tricks, we just open ".".
290 */
291 NTSTATUS openat_internal_dir_from_pathref(
292 struct files_struct *dirfsp,
293 int _open_flags,
294 struct files_struct **_fsp)
295 {
296 struct connection_struct *conn = dirfsp->conn;
297 struct smb_filename *smb_dname = dirfsp->fsp_name;
298 struct files_struct *fsp = NULL;
299 char dot[] = ".";
300 struct smb_filename smb_dot = {
301 .base_name = dot,
302 .flags = smb_dname->flags,
303 .twrp = smb_dname->twrp,
304 };
305 struct vfs_open_how how = { .flags = _open_flags, };
306 NTSTATUS status;
307
308 status = create_internal_dirfsp(conn, smb_dname, &fsp);
309 if (!NT_STATUS_IS_OK(status)) {
310 return status;
311 }
312
313 /*
314 * Pointless for opening ".", but you never know...
315 */
316 how.flags |= O_NOFOLLOW;
317
318 status = fd_openat(dirfsp, &smb_dot, fsp, &how);
319 if (!NT_STATUS_IS_OK(status)) {
320 DBG_INFO("fd_openat(\"%s\", \".\") failed: %s\n",
321 fsp_str_dbg(dirfsp),
322 nt_errstr(status));
323 file_free(NULL, fsp);
324 return status;
325 }
326
327 fsp->fsp_name->st = smb_dname->st;
328 fsp->file_id = vfs_file_id_from_sbuf(conn, &fsp->fsp_name->st);
329 *_fsp = fsp;
330 return NT_STATUS_OK;
331 }
332
333 /*
334 * The "link" in the name doesn't imply link in the filesystem
335 * sense. It's a object that "links" together an fsp and an smb_fname
336 * and the link allocated as talloc child of an fsp.
337 *
338 * The link is created for fsps that openat_pathref_fsp() returns in
339 * smb_fname->fsp. When this fsp is freed by file_free() by some caller
340 * somewhere, the destructor fsp_smb_fname_link_destructor() on the link object
341 * will use the link to reset the reference in smb_fname->fsp that is about to
342 * go away.
343 *
344 * This prevents smb_fname_internal_fsp_destructor() from seeing dangling fsp
345 * pointers.
346 */
347
348 struct fsp_smb_fname_link {
349 struct fsp_smb_fname_link **smb_fname_link;
350 struct files_struct **smb_fname_fsp;
351 };
352
353 static int fsp_smb_fname_link_destructor(struct fsp_smb_fname_link *link)
354 {
355 if (link->smb_fname_link == NULL) {
356 return 0;
357 }
358
359 *link->smb_fname_link = NULL;
360 *link->smb_fname_fsp = NULL;
361 return 0;
362 }
363
364 static NTSTATUS fsp_smb_fname_link(struct files_struct *fsp,
365 struct fsp_smb_fname_link **smb_fname_link,
366 struct files_struct **smb_fname_fsp)
367 {
368 struct fsp_smb_fname_link *link = NULL;
369
370 SMB_ASSERT(*smb_fname_link == NULL);
371 SMB_ASSERT(*smb_fname_fsp == NULL);
372
373 link = talloc_zero(fsp, struct fsp_smb_fname_link);
374 if (link == NULL) {
375 return NT_STATUS_NO_MEMORY;
376 }
377
378 link->smb_fname_link = smb_fname_link;
379 link->smb_fname_fsp = smb_fname_fsp;
380 *smb_fname_link = link;
381 *smb_fname_fsp = fsp;
382
383 talloc_set_destructor(link, fsp_smb_fname_link_destructor);
384 return NT_STATUS_OK;
385 }
386
387 /*
388 * Free a link, carefully avoiding to trigger the link destructor
389 */
390 static void destroy_fsp_smb_fname_link(struct fsp_smb_fname_link **_link)
391 {
392 struct fsp_smb_fname_link *link = *_link;
393
394 if (link == NULL) {
395 return;
396 }
397 talloc_set_destructor(link, NULL);
398 TALLOC_FREE(link);
399 *_link = NULL;
400 }
401
402 /*
403 * Talloc destructor set on an smb_fname set by openat_pathref_fsp() used to
404 * close the embedded smb_fname->fsp.
405 */
406 static int smb_fname_fsp_destructor(struct smb_filename *smb_fname)
407 {
408 struct files_struct *fsp = smb_fname->fsp;
409 NTSTATUS status;
410 int saved_errno = errno;
411
412 destroy_fsp_smb_fname_link(&smb_fname->fsp_link);
413
414 if (fsp == NULL) {
415 errno = saved_errno;
416 return 0;
417 }
418
419 if (fsp_is_alternate_stream(fsp)) {
420 struct files_struct *tmp_base_fsp = fsp->base_fsp;
421
422 fsp_set_base_fsp(fsp, NULL);
423
424 status = fd_close(tmp_base_fsp);
425 if (!NT_STATUS_IS_OK(status)) {
426 DBG_ERR("Closing fd for fsp [%s] failed: %s. "
427 "Please check your filesystem!!!\n",
428 fsp_str_dbg(fsp), nt_errstr(status));
429 }
430 file_free(NULL, tmp_base_fsp);
431 }
432
433 status = fd_close(fsp);
434 if (!NT_STATUS_IS_OK(status)) {
435 DBG_ERR("Closing fd for fsp [%s] failed: %s. "
436 "Please check your filesystem!!!\n",
437 fsp_str_dbg(fsp), nt_errstr(status));
438 }
439 file_free(NULL, fsp);
440 smb_fname->fsp = NULL;
441
442 errno = saved_errno;
443 return 0;
444 }
445
446 static NTSTATUS openat_pathref_fullname(
447 struct connection_struct *conn,
448 const struct files_struct *dirfsp,
449 struct files_struct *basefsp,
450 struct smb_filename **full_fname,
451 struct smb_filename *smb_fname,
452 const struct vfs_open_how *how)
453 {
454 struct files_struct *fsp = NULL;
455 bool have_dirfsp = (dirfsp != NULL);
456 bool have_basefsp = (basefsp != NULL);
457 NTSTATUS status;
458
459 DBG_DEBUG("smb_fname [%s]\n", smb_fname_str_dbg(smb_fname));
460
461 SMB_ASSERT(smb_fname->fsp == NULL);
462 SMB_ASSERT(have_dirfsp != have_basefsp);
463
464 status = fsp_new(conn, conn, &fsp);
465 if (!NT_STATUS_IS_OK(status)) {
466 return status;
467 }
468
469 GetTimeOfDay(&fsp->open_time);
470 fsp_set_gen_id(fsp);
471 ZERO_STRUCT(conn->sconn->fsp_fi_cache);
472
473 fsp->fsp_flags.is_pathref = true;
474
475 status = fsp_attach_smb_fname(fsp, full_fname);
476 if (!NT_STATUS_IS_OK(status)) {
477 goto fail;
478 }
479 fsp_set_base_fsp(fsp, basefsp);
480
481 status = fd_openat(dirfsp, smb_fname, fsp, how);
482 if (!NT_STATUS_IS_OK(status)) {
483
484 smb_fname->st = fsp->fsp_name->st;
485
486 if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND) ||
487 NT_STATUS_EQUAL(status, NT_STATUS_OBJECT_PATH_NOT_FOUND) ||
488 NT_STATUS_EQUAL(status, NT_STATUS_STOPPED_ON_SYMLINK))
489 {
490 /*
491 * streams_xattr return NT_STATUS_NOT_FOUND for
492 * opens of not yet existing streams.
493 *
494 * ELOOP maps to NT_STATUS_OBJECT_PATH_NOT_FOUND
495 * and this will result from a open request from
496 * a POSIX client on a symlink.
497 *
498 * NT_STATUS_OBJECT_NAME_NOT_FOUND is the simple
499 * ENOENT case.
500 *
501 * NT_STATUS_STOPPED_ON_SYMLINK is returned when trying
502 * to open a symlink, our callers are not interested in
503 * this.
504 */
505 status = NT_STATUS_OBJECT_NAME_NOT_FOUND;
506 }
507 goto fail;
508 }
509
510 /*
511 * fd_openat() has done an FSTAT on the handle
512 * so update the smb_fname stat info with "truth".
513 * from the handle.
514 */
515 smb_fname->st = fsp->fsp_name->st;
516
517 fsp->fsp_flags.is_directory = S_ISDIR(fsp->fsp_name->st.st_ex_mode);
518
519 fsp->file_id = vfs_file_id_from_sbuf(conn, &fsp->fsp_name->st);
520
521 status = fsp_smb_fname_link(fsp,
522 &smb_fname->fsp_link,
523 &smb_fname->fsp);
524 if (!NT_STATUS_IS_OK(status)) {
525 goto fail;
526 }
527
528 DBG_DEBUG("fsp [%s]: OK\n", fsp_str_dbg(fsp));
529
530 talloc_set_destructor(smb_fname, smb_fname_fsp_destructor);
531 return NT_STATUS_OK;
532
533 fail:
534 DBG_DEBUG("Opening pathref for [%s] failed: %s\n",
535 smb_fname_str_dbg(smb_fname),
536 nt_errstr(status));
537
538 fsp_set_base_fsp(fsp, NULL);
539 fd_close(fsp);
540 file_free(NULL, fsp);
541 return status;
542 }
543
544 /*
545 * Open an internal O_PATH based fsp for smb_fname. If O_PATH is not
546 * available, open O_RDONLY as root. Both is done in fd_open() ->
547 * non_widelink_open(), triggered by setting fsp->fsp_flags.is_pathref to
548 * true.
549 */
550 NTSTATUS openat_pathref_fsp(const struct files_struct *dirfsp,
551 struct smb_filename *smb_fname)
552 {
553 connection_struct *conn = dirfsp->conn;
554 struct smb_filename *full_fname = NULL;
555 struct smb_filename *base_fname = NULL;
556 struct vfs_open_how how = { .flags = O_RDONLY|O_NONBLOCK, };
557 NTSTATUS status;
558
559 DBG_DEBUG("smb_fname [%s]\n", smb_fname_str_dbg(smb_fname));
560
561 if (smb_fname->fsp != NULL) {
562 /* We already have one for this name. */
563 DBG_DEBUG("smb_fname [%s] already has a pathref fsp.\n",
564 smb_fname_str_dbg(smb_fname));
565 return NT_STATUS_OK;
566 }
567
568 if (is_named_stream(smb_fname) &&
569 ((conn->fs_capabilities & FILE_NAMED_STREAMS) == 0)) {
570 DBG_DEBUG("stream open [%s] on non-stream share\n",
571 smb_fname_str_dbg(smb_fname));
572 return NT_STATUS_OBJECT_NAME_INVALID;
573 }
574
575 if (!is_named_stream(smb_fname)) {
576 /*
577 * openat_pathref_fullname() will make "full_fname" a
578 * talloc child of the smb_fname->fsp. Don't use
579 * talloc_tos() to allocate it to avoid making the
580 * talloc stackframe pool long-lived.
581 */
582 full_fname = full_path_from_dirfsp_atname(
583 conn,
584 dirfsp,
585 smb_fname);
586 if (full_fname == NULL) {
587 status = NT_STATUS_NO_MEMORY;
588 goto fail;
589 }
590 status = openat_pathref_fullname(
591 conn, dirfsp, NULL, &full_fname, smb_fname, &how);
592 TALLOC_FREE(full_fname);
593 return status;
594 }
595
596 /*
597 * stream open
598 */
599 base_fname = cp_smb_filename_nostream(conn, smb_fname);
600 if (base_fname == NULL) {
601 return NT_STATUS_NO_MEMORY;
602 }
603
604 full_fname = full_path_from_dirfsp_atname(
605 conn, /* no talloc_tos(), see comment above */
606 dirfsp,
607 base_fname);
608 if (full_fname == NULL) {
609 status = NT_STATUS_NO_MEMORY;
610 goto fail;
611 }
612
613 status = openat_pathref_fullname(
614 conn, dirfsp, NULL, &full_fname, base_fname, &how);
615 TALLOC_FREE(full_fname);
616 if (!NT_STATUS_IS_OK(status)) {
617 DBG_DEBUG("openat_pathref_nostream failed: %s\n",
618 nt_errstr(status));
619 goto fail;
620 }
621
622 status = open_stream_pathref_fsp(&base_fname->fsp, smb_fname);
623 if (!NT_STATUS_IS_OK(status)) {
624 DBG_DEBUG("open_stream_pathref_fsp failed: %s\n",
625 nt_errstr(status));
626 goto fail;
627 }
628
629 smb_fname_fsp_unlink(base_fname);
630 fail:
631 TALLOC_FREE(base_fname);
632 return status;
633 }
634
635 /*
636 * Open a stream given an already opened base_fsp. Avoid
637 * non_widelink_open: This is only valid for the case where we have a
638 * valid non-cwd_fsp dirfsp that we can pass to SMB_VFS_OPENAT()
639 */
640 NTSTATUS open_stream_pathref_fsp(
641 struct files_struct **_base_fsp,
642 struct smb_filename *smb_fname)
643 {
644 struct files_struct *base_fsp = *_base_fsp;
645 connection_struct *conn = base_fsp->conn;
646 struct smb_filename *base_fname = base_fsp->fsp_name;
647 struct smb_filename *full_fname = NULL;
648 struct vfs_open_how how = { .flags = O_RDONLY|O_NONBLOCK, };
649 NTSTATUS status;
650
651 SMB_ASSERT(smb_fname->fsp == NULL);
652 SMB_ASSERT(is_named_stream(smb_fname));
653
654 full_fname = synthetic_smb_fname(
655 conn, /* no talloc_tos(), this will be long-lived */
656 base_fname->base_name,
657 smb_fname->stream_name,
658 &smb_fname->st,
659 smb_fname->twrp,
660 smb_fname->flags);
661 if (full_fname == NULL) {
662 return NT_STATUS_NO_MEMORY;
663 }
664
665 status = openat_pathref_fullname(
666 conn, NULL, base_fsp, &full_fname, smb_fname, &how);
667 TALLOC_FREE(full_fname);
668 return status;
669 }
670
671 static char *path_to_strv(TALLOC_CTX *mem_ctx, const char *path)
672 {
673 char *result = talloc_strdup(mem_ctx, path);
674
675 if (result == NULL) {
676 return NULL;
677 }
678 string_replace(result, '/', '\0');
679 return result;
680 }
681
682 NTSTATUS readlink_talloc(
683 TALLOC_CTX *mem_ctx,
684 struct files_struct *dirfsp,
685 struct smb_filename *smb_relname,
686 char **_substitute)
687 {
688 char buf[PATH_MAX];
689 ssize_t ret;
690 char *substitute;
691 NTSTATUS status;
692
693 if (_substitute == NULL) {
694 return NT_STATUS_OK;
695 }
696
697 if (smb_relname == NULL) {
698 /*
699 * We have a Linux O_PATH handle in dirfsp and want to
700 * read its value, essentially a freadlink
701 */
702 smb_relname = synthetic_smb_fname(
703 talloc_tos(), "", NULL, NULL, 0, 0);
704 if (smb_relname == NULL) {
705 DBG_DEBUG("synthetic_smb_fname() failed\n");
706 return NT_STATUS_NO_MEMORY;
707 }
708 }
709
710 ret = SMB_VFS_READLINKAT(
711 dirfsp->conn, dirfsp, smb_relname, buf, sizeof(buf));
712 if (ret < 0) {
713 status = map_nt_error_from_unix(errno);
714 DBG_DEBUG("SMB_VFS_READLINKAT() failed: %s\n",
715 strerror(errno));
716 return status;
717 }
718
719 if ((size_t)ret == sizeof(buf)) {
720 /*
721 * Do we need symlink targets longer than PATH_MAX?
722 */
723 DBG_DEBUG("Got full %zu bytes from readlink, too long\n",
724 sizeof(buf));
725 return NT_STATUS_BUFFER_OVERFLOW;
726 }
727
728 substitute = talloc_strndup(mem_ctx, buf, ret);
729 if (substitute == NULL) {
730 DBG_DEBUG("talloc_strndup() failed\n");
731 return NT_STATUS_NO_MEMORY;
732 }
733
734 *_substitute = substitute;
735 return NT_STATUS_OK;
736 }
737
738 NTSTATUS openat_pathref_dirfsp_nosymlink(
739 TALLOC_CTX *mem_ctx,
740 struct connection_struct *conn,
741 const char *path_in,
742 NTTIME twrp,
743 struct smb_filename **_smb_fname,
744 size_t *unparsed,
745 char **substitute)
746 {
747 struct files_struct *dirfsp = conn->cwd_fsp;
748 struct smb_filename full_fname = {
749 .base_name = NULL,
750 .twrp = twrp,
751 };
752 struct smb_filename rel_fname = {
753 .base_name = NULL,
754 .twrp = twrp,
755 };
756 struct smb_filename *result = NULL;
757 struct files_struct *fsp = NULL;
758 char *path = NULL, *next = NULL;
759 int fd;
760 NTSTATUS status;
761 struct vfs_open_how how = {
762 .flags = O_NOFOLLOW|O_DIRECTORY,
763 .mode = 0,
764 };
765
766 DBG_DEBUG("path_in=%s\n", path_in);
767
768 status = fsp_new(conn, conn, &fsp);
769 if (!NT_STATUS_IS_OK(status)) {
770 DBG_DEBUG("fsp_new() failed: %s\n", nt_errstr(status));
771 goto fail;
772 }
773 fsp->fsp_name = &full_fname;
774
775 #ifdef O_PATH
776 /*
777 * Add O_PATH manually, doing this by setting
778 * fsp->fsp_flags.is_pathref will make us become_root() in the
779 * non-O_PATH case, which would cause a security problem.
780 */
781 how.flags |= O_PATH;
782 #else
783 #ifdef O_SEARCH
784 /*
785 * O_SEARCH just checks for the "x" bit. We are traversing
786 * directories, so we don't need the implicit O_RDONLY ("r"
787 * permissions) but only the "x"-permissions requested by
788 * O_SEARCH. We need either O_PATH or O_SEARCH to correctly
789 * function, without either we will incorrectly require also
790 * the "r" bit when traversing the directory hierarchy.
791 */
792 how.flags |= O_SEARCH;
793 #endif
794 #endif
795
796 full_fname.base_name = talloc_strdup(talloc_tos(), "");
797 if (full_fname.base_name == NULL) {
798 DBG_DEBUG("talloc_strdup() failed\n");
799 goto nomem;
800 }
801
802 /*
803 * First split the path into individual components.
804 */
805 path = path_to_strv(talloc_tos(), path_in);
806 if (path == NULL) {
807 DBG_DEBUG("path_to_strv() failed\n");
808 goto nomem;
809 }
810
811 /*
812 * First we loop over all components
813 * in order to verify, there's no '.' or '..'
814 */
815 rel_fname.base_name = path;
816 while (rel_fname.base_name != NULL) {
817
818 next = strv_next(path, rel_fname.base_name);
819
820 /*
821 * Path sanitizing further up has cleaned or rejected
822 * empty path components. Assert this here.
823 */
824 SMB_ASSERT(rel_fname.base_name[0] != '\0');
825
826 if (ISDOT(rel_fname.base_name) ||
827 ISDOTDOT(rel_fname.base_name)) {
828 DBG_DEBUG("%s contains a dot\n", path_in);
829 status = NT_STATUS_OBJECT_NAME_INVALID;
830 goto fail;
831 }
832
833 /* Check veto files. */
834 if (IS_VETO_PATH(conn, rel_fname.base_name)) {
835 DBG_DEBUG("%s contains veto files path component %s\n",
836 path_in, rel_fname.base_name);
837 status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
838 goto fail;
839 }
840
841 rel_fname.base_name = next;
842 }
843
844 if (conn->open_how_resolve & VFS_OPEN_HOW_RESOLVE_NO_SYMLINKS) {
845
846 /*
847 * Try a direct openat2 with RESOLVE_NO_SYMLINKS to
848 * avoid the openat/close loop further down.
849 */
850
851 rel_fname.base_name = discard_const_p(char, path_in);
852 how.resolve = VFS_OPEN_HOW_RESOLVE_NO_SYMLINKS;
853
854 fd = SMB_VFS_OPENAT(conn, dirfsp, &rel_fname, fsp, &how);
855 if (fd >= 0) {
856 fsp_set_fd(fsp, fd);
857 TALLOC_FREE(full_fname.base_name);
858 full_fname = rel_fname;
859 goto done;
860 }
861
862 status = map_nt_error_from_unix(errno);
863 DBG_DEBUG("SMB_VFS_OPENAT(%s, %s, RESOLVE_NO_SYMLINKS) "
864 "returned %d %s => %s\n",
865 smb_fname_str_dbg(dirfsp->fsp_name), path_in,
866 errno, strerror(errno), nt_errstr(status));
867 SMB_ASSERT(fd == -1);
868 switch (errno) {
869 case ENOSYS:
870 /*
871 * We got ENOSYS, so fallback to the old code
872 * if the kernel doesn't support openat2() yet.
873 */
874 break;
875
876 case ELOOP:
877 case ENOTDIR:
878 /*
879 * For ELOOP we also fallback in order to
880 * return the correct information with
881 * NT_STATUS_STOPPED_ON_SYMLINK.
882 *
883 * O_NOFOLLOW|O_DIRECTORY results in
884 * ENOTDIR instead of ELOOP for the final
885 * component.
886 */
887 break;
888
889 case ENOENT:
890 /*
891 * If we got ENOENT, the filesystem could
892 * be case sensitive. For now we only do
893 * the get_real_filename_at() dance in
894 * the fallback loop below.
895 */
896 break;
897
898 default:
899 goto fail;
900 }
901
902 /*
903 * Just fallback to the openat loop
904 */
905 how.resolve = 0;
906 }
907
908 /*
909 * Now we loop over all components
910 * opening each one and using it
911 * as dirfd for the next one.
912 *
913 * It means we can detect symlinks
914 * within the path.
915 */
916 rel_fname.base_name = path;
917 next:
918 next = strv_next(path, rel_fname.base_name);
919
920 fd = SMB_VFS_OPENAT(
921 conn,
922 dirfsp,
923 &rel_fname,
924 fsp,
925 &how);
926
927 if ((fd == -1) && (errno == ENOENT)) {
928 const char *orig_base_name = rel_fname.base_name;
929
930 status = get_real_filename_at(
931 dirfsp,
932 rel_fname.base_name,
933 talloc_tos(),
934 &rel_fname.base_name);
935
936 if (!NT_STATUS_IS_OK(status)) {
937 DBG_DEBUG("get_real_filename_at failed: %s\n",
938 nt_errstr(status));
939 goto fail;
940 }
941
942 /* Name might have been demangled - check veto files. */
943 if (IS_VETO_PATH(conn, rel_fname.base_name)) {
944 DBG_DEBUG("%s contains veto files path component "
945 "%s => %s\n",
946 path_in,
947 orig_base_name,
948 rel_fname.base_name);
949 status = NT_STATUS_OBJECT_PATH_NOT_FOUND;
950 goto fail;
951 }
952
953 fd = SMB_VFS_OPENAT(
954 conn,
955 dirfsp,
956 &rel_fname,
957 fsp,
958 &how);
959 }
960
961 /*
962 * O_NOFOLLOW|O_DIRECTORY results in
963 * ENOTDIR instead of ELOOP.
964 *
965 * But we should be prepared to handle ELOOP too.
966 */
967 if ((fd == -1) && (errno == ENOTDIR || errno == ELOOP)) {
968 NTSTATUS orig_status = map_nt_error_from_unix(errno);
969
970 status = readlink_talloc(
971 mem_ctx, dirfsp, &rel_fname, substitute);
972
973 if (NT_STATUS_IS_OK(status)) {
974 /*
975 * readlink_talloc() found a symlink
976 */
977 status = NT_STATUS_STOPPED_ON_SYMLINK;
978
979 if (unparsed != NULL) {
980 if (next == NULL) {
981 *unparsed = 0;
982 } else {
983 size_t parsed = next - path;
984 size_t len = talloc_get_size(path);
985 *unparsed = len - parsed;
986 }
987 }
988 /*
989 * If we're on an MSDFS share, see if this is
990 * an MSDFS link.
991 */
992 if (lp_host_msdfs() &&
993 lp_msdfs_root(SNUM(conn)) &&
994 (substitute != NULL) &&
995 strnequal(*substitute, "msdfs:", 6) &&
996 is_msdfs_link(dirfsp, &rel_fname))
997 {
998 status = NT_STATUS_PATH_NOT_COVERED;
999 }
1000 } else {
1001
1002 DBG_DEBUG("readlink_talloc failed: %s\n",
1003 nt_errstr(status));
1004 /*
1005 * Restore the error status from SMB_VFS_OPENAT()
1006 */
1007 status = orig_status;
1008 }
1009 goto fail;
1010 }
1011
1012 if (fd == -1) {
1013 status = map_nt_error_from_unix(errno);
1014 DBG_DEBUG("SMB_VFS_OPENAT() failed: %s\n",
1015 strerror(errno));
1016 goto fail;
1017 }
1018 fsp_set_fd(fsp, fd);
1019
1020 fsp->fsp_flags.is_directory = true; /* See O_DIRECTORY above */
1021
1022 full_fname.base_name = talloc_asprintf_append_buffer(
1023 full_fname.base_name,
1024 "%s%s",
1025 full_fname.base_name[0] == '\0' ? "" : "/",
1026 rel_fname.base_name);
1027
1028 if (full_fname.base_name == NULL) {
1029 DBG_DEBUG("talloc_asprintf_append_buffer() failed\n");
1030 goto nomem;
1031 }
1032
1033 if (next != NULL) {
1034 struct files_struct *tmp = NULL;
1035
1036 if (dirfsp != conn->cwd_fsp) {
1037 fd_close(dirfsp);
1038 }
1039
1040 tmp = dirfsp;
1041 dirfsp = fsp;
1042
1043 if (tmp == conn->cwd_fsp) {
1044 status = fsp_new(conn, conn, &fsp);
1045 if (!NT_STATUS_IS_OK(status)) {
1046 DBG_DEBUG("fsp_new() failed: %s\n",
1047 nt_errstr(status));
1048 goto fail;
1049 }
1050 fsp->fsp_name = &full_fname;
1051 } else {
1052 fsp = tmp;
1053 }
1054
1055 rel_fname.base_name = next;
1056
1057 goto next;
1058 }
1059
1060 if (dirfsp != conn->cwd_fsp) {
1061 dirfsp->fsp_name = NULL;
1062 SMB_ASSERT(fsp_get_pathref_fd(dirfsp) != -1);
1063 fd_close(dirfsp);
1064 file_free(NULL, dirfsp);
1065 dirfsp = NULL;
1066 }
1067
1068 done:
1069 fsp->fsp_flags.is_pathref = true;
1070 fsp->fsp_name = NULL;
1071
1072 status = fsp_set_smb_fname(fsp, &full_fname);
1073 if (!NT_STATUS_IS_OK(status)) {
1074 DBG_DEBUG("fsp_set_smb_fname() failed: %s\n",
1075 nt_errstr(status));
1076 goto fail;
1077 }
1078
1079 status = vfs_stat_fsp(fsp);
1080 if (!NT_STATUS_IS_OK(status)) {
1081 DBG_DEBUG("vfs_stat_fsp(%s) failed: %s\n",
1082 fsp_str_dbg(fsp),
1083 nt_errstr(status));
1084 goto fail;
1085 }
1086 /*
1087 * We must correctly set fsp->file_id as code inside
1088 * open.c will use this to check if delete_on_close
1089 * has been set on the dirfsp.
1090 */
1091 fsp->file_id = vfs_file_id_from_sbuf(conn, &fsp->fsp_name->st);
1092
1093 result = cp_smb_filename(mem_ctx, fsp->fsp_name);
1094 if (result == NULL) {
1095 DBG_DEBUG("cp_smb_filename() failed\n");
1096 goto nomem;
1097 }
1098
1099 status = fsp_smb_fname_link(fsp,
1100 &result->fsp_link,
1101 &result->fsp);
1102 if (!NT_STATUS_IS_OK(status)) {
1103 goto fail;
1104 }
1105 talloc_set_destructor(result, smb_fname_fsp_destructor);
1106
1107 *_smb_fname = result;
1108
1109 DBG_DEBUG("returning %s\n", smb_fname_str_dbg(result));
1110
1111 return NT_STATUS_OK;
1112
1113 nomem:
1114 status = NT_STATUS_NO_MEMORY;
1115 fail:
1116 if (fsp != NULL) {
1117 if (fsp_get_pathref_fd(fsp) != -1) {
1118 fd_close(fsp);
1119 }
1120 file_free(NULL, fsp);
1121 fsp = NULL;
1122 }
1123
1124 if ((dirfsp != NULL) && (dirfsp != conn->cwd_fsp)) {
1125 dirfsp->fsp_name = NULL;
1126 SMB_ASSERT(fsp_get_pathref_fd(dirfsp) != -1);
1127 fd_close(dirfsp);
1128 file_free(NULL, dirfsp);
1129 dirfsp = NULL;
1130 }
1131
1132 TALLOC_FREE(path);
1133 return status;
1134 }
1135
1136 void smb_fname_fsp_unlink(struct smb_filename *smb_fname)
1137 {
1138 talloc_set_destructor(smb_fname, NULL);
1139 smb_fname->fsp = NULL;
1140 destroy_fsp_smb_fname_link(&smb_fname->fsp_link);
1141 }
1142
1143 /*
1144 * Move any existing embedded fsp refs from the src name to the
1145 * destination. It's safe to call this on src smb_fname's that have no embedded
1146 * pathref fsp.
1147 */
1148 NTSTATUS move_smb_fname_fsp_link(struct smb_filename *smb_fname_dst,
1149 struct smb_filename *smb_fname_src)
1150 {
1151 NTSTATUS status;
1152
1153 /*
1154 * The target should always not be linked yet!
1155 */
1156 SMB_ASSERT(smb_fname_dst->fsp == NULL);
1157 SMB_ASSERT(smb_fname_dst->fsp_link == NULL);
1158
1159 if (smb_fname_src->fsp == NULL) {
1160 return NT_STATUS_OK;
1161 }
1162
1163 status = fsp_smb_fname_link(smb_fname_src->fsp,
1164 &smb_fname_dst->fsp_link,
1165 &smb_fname_dst->fsp);
1166 if (!NT_STATUS_IS_OK(status)) {
1167 return status;
1168 }
1169
1170 talloc_set_destructor(smb_fname_dst, smb_fname_fsp_destructor);
1171
1172 smb_fname_fsp_unlink(smb_fname_src);
1173
1174 return NT_STATUS_OK;
1175 }
1176
1177 /**
1178 * Create an smb_fname and open smb_fname->fsp pathref
1179 **/
1180 NTSTATUS synthetic_pathref(TALLOC_CTX *mem_ctx,
1181 struct files_struct *dirfsp,
1182 const char *base_name,
1183 const char *stream_name,
1184 const SMB_STRUCT_STAT *psbuf,
1185 NTTIME twrp,
1186 uint32_t flags,
1187 struct smb_filename **_smb_fname)
1188 {
1189 struct smb_filename *smb_fname = NULL;
1190 NTSTATUS status;
1191
1192 smb_fname = synthetic_smb_fname(mem_ctx,
1193 base_name,
1194 stream_name,
1195 psbuf,
1196 twrp,
1197 flags);
1198 if (smb_fname == NULL) {
1199 return NT_STATUS_NO_MEMORY;
1200 }
1201
1202 status = openat_pathref_fsp(dirfsp, smb_fname);
1203 if (!NT_STATUS_IS_OK(status)) {
1204 DBG_ERR("opening [%s] failed\n",
1205 smb_fname_str_dbg(smb_fname));
1206 TALLOC_FREE(smb_fname);
1207 return status;
1208 }
1209
1210 *_smb_fname = smb_fname;
1211 return NT_STATUS_OK;
1212 }
1213
1214 static int atname_destructor(struct smb_filename *smb_fname)
1215 {
1216 destroy_fsp_smb_fname_link(&smb_fname->fsp_link);
1217 return 0;
1218 }
1219
1220 /**
1221 * Turn a path into a parent pathref and atname
1222 *
1223 * This returns the parent pathref in _parent and the name relative to it. If
1224 * smb_fname was a pathref (ie smb_fname->fsp != NULL), then _atname will be a
1225 * pathref as well, ie _atname->fsp will point at the same fsp as
1226 * smb_fname->fsp.
1227 **/
1228 NTSTATUS parent_pathref(TALLOC_CTX *mem_ctx,
1229 struct files_struct *dirfsp,
1230 const struct smb_filename *smb_fname,
1231 struct smb_filename **_parent,
1232 struct smb_filename **_atname)
1233 {
1234 struct smb_filename *parent = NULL;
1235 struct smb_filename *atname = NULL;
1236 NTSTATUS status;
1237
1238 status = SMB_VFS_PARENT_PATHNAME(dirfsp->conn,
1239 mem_ctx,
1240 smb_fname,
1241 &parent,
1242 &atname);
1243 if (!NT_STATUS_IS_OK(status)) {
1244 return status;
1245 }
1246
1247 /*
1248 * We know that the parent name must
1249 * exist, and the name has been canonicalized
1250 * even if this was a POSIX pathname.
1251 * Ensure that we follow symlinks for
1252 * the parent. See the torture test
1253 * POSIX-SYMLINK-PARENT for details.
1254 */
1255 parent->flags &= ~SMB_FILENAME_POSIX_PATH;
1256
1257 status = openat_pathref_fsp(dirfsp, parent);
1258 if (!NT_STATUS_IS_OK(status)) {
1259 TALLOC_FREE(parent);
1260 return status;
1261 }
1262
1263 if (smb_fname->fsp != NULL) {
1264 status = fsp_smb_fname_link(smb_fname->fsp,
1265 &atname->fsp_link,
1266 &atname->fsp);
1267 if (!NT_STATUS_IS_OK(status)) {
1268 TALLOC_FREE(parent);
1269 return status;
1270 }
1271 talloc_set_destructor(atname, atname_destructor);
1272 }
1273 *_parent = parent;
1274 *_atname = atname;
1275 return NT_STATUS_OK;
1276 }
1277
1278 static bool close_file_in_loop(struct files_struct *fsp,
1279 enum file_close_type close_type)
1280 {
1281 if (fsp_is_alternate_stream(fsp)) {
1282 /*
1283 * This is a stream, it can't be a base
1284 */
1285 SMB_ASSERT(fsp->stream_fsp == NULL);
1286 SMB_ASSERT(fsp->base_fsp->stream_fsp == fsp);
1287
1288 /*
1289 * Remove the base<->stream link so that
1290 * close_file_free() does not close fsp->base_fsp as
1291 * well. This would destroy walking the linked list of
1292 * fsps.
1293 */
1294 fsp->base_fsp->stream_fsp = NULL;
1295 fsp->base_fsp = NULL;
1296
1297 close_file_free(NULL, &fsp, close_type);
1298 return NULL;
1299 }
1300
1301 if (fsp->stream_fsp != NULL) {
1302 /*
1303 * This is the base of a stream.
1304 */
1305 SMB_ASSERT(fsp->stream_fsp->base_fsp == fsp);
1306
1307 /*
1308 * Remove the base<->stream link. This will make fsp
1309 * look like a normal fsp for the next round.
1310 */
1311 fsp->stream_fsp->base_fsp = NULL;
1312 fsp->stream_fsp = NULL;
1313
1314 /*
1315 * Have us called back a second time. In the second
1316 * round, "fsp" now looks like a normal fsp.
1317 */
1318 return false;
1319 }
1320
1321 close_file_free(NULL, &fsp, close_type);
1322 return true;
1323 }
1324
1325 /****************************************************************************
1326 Close all open files for a connection.
1327 ****************************************************************************/
1328
1329 struct file_close_conn_state {
1330 struct connection_struct *conn;
1331 enum file_close_type close_type;
1332 bool fsp_left_behind;
1333 };
1334
1335 static struct files_struct *file_close_conn_fn(
1336 struct files_struct *fsp,
1337 void *private_data)
1338 {
1339 struct file_close_conn_state *state = private_data;
1340 bool did_close;
1341
1342 if (fsp->conn != state->conn) {
1343 return NULL;
1344 }
1345
1346 if (fsp->op != NULL && fsp->op->global->durable) {
1347 /*
1348 * A tree disconnect closes a durable handle
1349 */
1350 fsp->op->global->durable = false;
1351 }
1352
1353 did_close = close_file_in_loop(fsp, state->close_type);
1354 if (!did_close) {
1355 state->fsp_left_behind = true;
1356 }
1357
1358 return NULL;
1359 }
1360
1361 void file_close_conn(connection_struct *conn, enum file_close_type close_type)
1362 {
1363 struct file_close_conn_state state = { .conn = conn,
1364 .close_type = close_type };
1365
1366 files_forall(conn->sconn, file_close_conn_fn, &state);
1367
1368 if (state.fsp_left_behind) {
1369 state.fsp_left_behind = false;
1370 files_forall(conn->sconn, file_close_conn_fn, &state);
1371 SMB_ASSERT(!state.fsp_left_behind);
1372 }
1373 }
1374
1375 /****************************************************************************
1376 Initialise file structures.
1377 ****************************************************************************/
1378
1379 static int files_max_open_fds;
1380
1381 bool file_init_global(void)
1382 {
1383 int request_max = lp_max_open_files();
1384 int real_lim;
1385 int real_max;
1386
1387 if (files_max_open_fds != 0) {
1388 return true;
1389 }
1390
1391 /*
1392 * Set the max_open files to be the requested
1393 * max plus a fudgefactor to allow for the extra
1394 * fd's we need such as log files etc...
1395 */
1396 real_lim = set_maxfiles(request_max + MAX_OPEN_FUDGEFACTOR);
1397
1398 real_max = real_lim - MAX_OPEN_FUDGEFACTOR;
1399
1400 if (real_max + FILE_HANDLE_OFFSET + MAX_OPEN_PIPES > 65536) {
1401 real_max = 65536 - FILE_HANDLE_OFFSET - MAX_OPEN_PIPES;
1402 }
1403
1404 if (real_max != request_max) {
1405 DEBUG(1, ("file_init_global: Information only: requested %d "
1406 "open files, %d are available.\n",
1407 request_max, real_max));
1408 }
1409
1410 SMB_ASSERT(real_max > 100);
1411
1412 files_max_open_fds = real_max;
1413 return true;
1414 }
1415
1416 bool file_init(struct smbd_server_connection *sconn)
1417 {
1418 bool ok;
1419
1420 ok = file_init_global();
1421 if (!ok) {
1422 return false;
1423 }
1424
1425 sconn->real_max_open_files = files_max_open_fds;
1426
1427 return true;
1428 }
1429
1430 /****************************************************************************
1431 Close files open by a specified vuid.
1432 ****************************************************************************/
1433
1434 struct file_close_user_state {
1435 uint64_t vuid;
1436 bool fsp_left_behind;
1437 };
1438
1439 static struct files_struct *file_close_user_fn(
1440 struct files_struct *fsp,
1441 void *private_data)
1442 {
1443 struct file_close_user_state *state = private_data;
1444 bool did_close;
1445
1446 if (fsp->vuid != state->vuid) {
1447 return NULL;
1448 }
1449
1450 did_close = close_file_in_loop(fsp, SHUTDOWN_CLOSE);
1451 if (!did_close) {
1452 state->fsp_left_behind = true;
1453 }
1454
1455 return NULL;
1456 }
1457
1458 void file_close_user(struct smbd_server_connection *sconn, uint64_t vuid)
1459 {
1460 struct file_close_user_state state = { .vuid = vuid };
1461
1462 files_forall(sconn, file_close_user_fn, &state);
1463
1464 if (state.fsp_left_behind) {
1465 state.fsp_left_behind = false;
1466 files_forall(sconn, file_close_user_fn, &state);
1467 SMB_ASSERT(!state.fsp_left_behind);
1468 }
1469 }
1470
1471 /*
1472 * Walk the files table until "fn" returns non-NULL
1473 */
1474
1475 struct files_struct *files_forall(
1476 struct smbd_server_connection *sconn,
1477 struct files_struct *(*fn)(struct files_struct *fsp,
1478 void *private_data),
1479 void *private_data)
1480 {
1481 struct files_struct *fsp, *next;
1482
1483 for (fsp = sconn->files; fsp; fsp = next) {
1484 struct files_struct *ret;
1485 next = fsp->next;
1486 ret = fn(fsp, private_data);
1487 if (ret != NULL) {
1488 return ret;
1489 }
1490 }
1491 return NULL;
1492 }
1493
1494 /****************************************************************************
1495 Find a fsp given a file descriptor.
1496 ****************************************************************************/
1497
1498 files_struct *file_find_fd(struct smbd_server_connection *sconn, int fd)
1499 {
1500 int count=0;
1501 files_struct *fsp;
1502
1503 for (fsp=sconn->files; fsp; fsp=fsp->next,count++) {
1504 if (fsp_get_pathref_fd(fsp) == fd) {
1505 if (count > 10) {
1506 DLIST_PROMOTE(sconn->files, fsp);
1507 }
1508 return fsp;
1509 }
1510 }
1511
1512 return NULL;
1513 }
1514
1515 /****************************************************************************
1516 Find a fsp given a device, inode and file_id.
1517 ****************************************************************************/
1518
1519 files_struct *file_find_dif(struct smbd_server_connection *sconn,
1520 struct file_id id, unsigned long gen_id)
1521 {
1522 int count=0;
1523 files_struct *fsp;
1524
1525 if (gen_id == 0) {
1526 return NULL;
1527 }
1528
1529 for (fsp = sconn->files; fsp; fsp = fsp->next,count++) {
1530 /*
1531 * We can have a fsp->fh->fd == -1 here as it could be a stat
1532 * open.
1533 */
1534 if (!file_id_equal(&fsp->file_id, &id)) {
1535 continue;
1536 }
1537 if (!fsp->fsp_flags.is_fsa) {
1538 continue;
1539 }
1540 if (fh_get_gen_id(fsp->fh) != gen_id) {
1541 continue;
1542 }
1543 if (count > 10) {
1544 DLIST_PROMOTE(sconn->files, fsp);
1545 }
1546 /* Paranoia check. */
1547 if ((fsp_get_pathref_fd(fsp) == -1) &&
1548 (fsp->oplock_type != NO_OPLOCK &&
1549 fsp->oplock_type != LEASE_OPLOCK))
1550 {
1551 struct file_id_buf idbuf;
1552
1553 DBG_ERR("file %s file_id = "
1554 "%s, gen = %u oplock_type = %u is a "
1555 "stat open with oplock type !\n",
1556 fsp_str_dbg(fsp),
1557 file_id_str_buf(fsp->file_id, &idbuf),
1558 (unsigned int)fh_get_gen_id(fsp->fh),
1559 (unsigned int)fsp->oplock_type);
1560 smb_panic("file_find_dif");
1561 }
1562 return fsp;
1563 }
1564
1565 return NULL;
1566 }
1567
1568 /****************************************************************************
1569 Find the first fsp given a device and inode.
1570 We use a singleton cache here to speed up searching from getfilepathinfo
1571 calls.
1572 ****************************************************************************/
1573
1574 files_struct *file_find_di_first(struct smbd_server_connection *sconn,
1575 struct file_id id,
1576 bool need_fsa)
1577 {
1578 files_struct *fsp;
1579
1580 if (file_id_equal(&sconn->fsp_fi_cache.id, &id)) {
1581 /* Positive or negative cache hit. */
1582 return sconn->fsp_fi_cache.fsp;
1583 }
1584
1585 sconn->fsp_fi_cache.id = id;
1586
1587 for (fsp=sconn->files;fsp;fsp=fsp->next) {
1588 if (need_fsa && !fsp->fsp_flags.is_fsa) {
1589 continue;
1590 }
1591 if (file_id_equal(&fsp->file_id, &id)) {
1592 /* Setup positive cache. */
1593 sconn->fsp_fi_cache.fsp = fsp;
1594 return fsp;
1595 }
1596 }
1597
1598 /* Setup negative cache. */
1599 sconn->fsp_fi_cache.fsp = NULL;
1600 return NULL;
1601 }
1602
1603 /****************************************************************************
1604 Find the next fsp having the same device and inode.
1605 ****************************************************************************/
1606
1607 files_struct *file_find_di_next(files_struct *start_fsp,
1608 bool need_fsa)
1609 {
1610 files_struct *fsp;
1611
1612 for (fsp = start_fsp->next;fsp;fsp=fsp->next) {
1613 if (need_fsa && !fsp->fsp_flags.is_fsa) {
1614 continue;
1615 }
1616 if (file_id_equal(&fsp->file_id, &start_fsp->file_id)) {
1617 return fsp;
1618 }
1619 }
1620
1621 return NULL;
1622 }
1623
1624 struct files_struct *file_find_one_fsp_from_lease_key(
1625 struct smbd_server_connection *sconn,
1626 const struct smb2_lease_key *lease_key)
1627 {
1628 struct files_struct *fsp;
1629
1630 for (fsp = sconn->files; fsp; fsp=fsp->next) {
1631 if ((fsp->lease != NULL) &&
1632 (fsp->lease->lease.lease_key.data[0] ==
1633 lease_key->data[0]) &&
1634 (fsp->lease->lease.lease_key.data[1] ==
1635 lease_key->data[1])) {
1636 return fsp;
1637 }
1638 }
1639 return NULL;
1640 }
1641
1642 /****************************************************************************
1643 Find any fsp open with a pathname below that of an already open path.
1644 ****************************************************************************/
1645
1646 bool file_find_subpath(files_struct *dir_fsp)
1647 {
1648 files_struct *fsp;
1649 size_t dlen;
1650 char *d_fullname = NULL;
1651
1652 d_fullname = talloc_asprintf(talloc_tos(), "%s/%s",
1653 dir_fsp->conn->connectpath,
1654 dir_fsp->fsp_name->base_name);
1655
1656 if (!d_fullname) {
1657 return false;
1658 }
1659
1660 dlen = strlen(d_fullname);
1661
1662 for (fsp=dir_fsp->conn->sconn->files; fsp; fsp=fsp->next) {
1663 char *d1_fullname;
1664
1665 if (fsp == dir_fsp) {
1666 continue;
1667 }
1668
1669 d1_fullname = talloc_asprintf(talloc_tos(),
1670 "%s/%s",
1671 fsp->conn->connectpath,
1672 fsp->fsp_name->base_name);
1673
1674 /*
1675 * If the open file has a path that is a longer
1676 * component, then it's a subpath.
1677 */
1678 if (strnequal(d_fullname, d1_fullname, dlen) &&
1679 (d1_fullname[dlen] == '/')) {
1680 TALLOC_FREE(d1_fullname);
1681 TALLOC_FREE(d_fullname);
1682 return true;
1683 }
1684 TALLOC_FREE(d1_fullname);
1685 }
1686
1687 TALLOC_FREE(d_fullname);
1688 return false;
1689 }
1690
1691 /****************************************************************************
1692 Free up a fsp.
1693 ****************************************************************************/
1694
1695 static void fsp_free(files_struct *fsp)
1696 {
1697 struct smbd_server_connection *sconn = fsp->conn->sconn;
1698
1699 if (fsp == sconn->fsp_fi_cache.fsp) {
1700 ZERO_STRUCT(sconn->fsp_fi_cache);
1701 }
1702
1703 DLIST_REMOVE(sconn->files, fsp);
1704 SMB_ASSERT(sconn->num_files > 0);
1705 sconn->num_files--;
1706
1707 TALLOC_FREE(fsp->fake_file_handle);
1708
1709 if (fh_get_refcount(fsp->fh) == 1) {
1710 TALLOC_FREE(fsp->fh);
1711 } else {
1712 size_t new_refcount = fh_get_refcount(fsp->fh) - 1;
1713 fh_set_refcount(fsp->fh, new_refcount);
1714 }
1715
1716 if (fsp->lease != NULL) {
1717 if (fsp->lease->ref_count == 1) {
1718 TALLOC_FREE(fsp->lease);
1719 } else {
1720 fsp->lease->ref_count--;
1721 }
1722 }
1723
1724 fsp->conn->num_files_open--;
1725
1726 if (fsp->fsp_name != NULL &&
1727 fsp->fsp_name->fsp_link != NULL)
1728 {
1729 /*
1730 * Free fsp_link of fsp->fsp_name. To do this in the correct
1731 * talloc destructor order we have to do it here. The
1732 * talloc_free() of the link should set the fsp pointer to NULL.
1733 */
1734 TALLOC_FREE(fsp->fsp_name->fsp_link);
1735 SMB_ASSERT(fsp->fsp_name->fsp == NULL);
1736 }
1737
1738 /* this is paranoia, just in case someone tries to reuse the
1739 information */
1740 ZERO_STRUCTP(fsp);
1741
1742 /* fsp->fsp_name is a talloc child and is free'd automatically. */
1743 TALLOC_FREE(fsp);
1744 }
1745
1746 /*
1747 * Rundown of all smb-related sub-structures of an fsp
1748 */
1749 void fsp_unbind_smb(struct smb_request *req, files_struct *fsp)
1750 {
1751 if (fsp == fsp->conn->cwd_fsp) {
1752 return;
1753 }
1754
1755 if (fsp->notify) {
1756 size_t len = fsp_fullbasepath(fsp, NULL, 0);
1757 char fullpath[len+1];
1758
1759 fsp_fullbasepath(fsp, fullpath, sizeof(fullpath));
1760
1761 /*
1762 * Avoid /. at the end of the path name. notify can't
1763 * deal with it.
1764 */
1765 if (len > 1 && fullpath[len-1] == '.' &&
1766 fullpath[len-2] == '/') {
1767 fullpath[len-2] = '\0';
1768 }
1769
1770 notify_remove(fsp->conn->sconn->notify_ctx, fsp, fullpath);
1771 TALLOC_FREE(fsp->notify);
1772 }
1773
1774 /* Ensure this event will never fire. */
1775 TALLOC_FREE(fsp->update_write_time_event);
1776
1777 if (fsp->op != NULL) {
1778 fsp->op->compat = NULL;
1779 }
1780 TALLOC_FREE(fsp->op);
1781
1782 if ((req != NULL) && (fsp == req->chain_fsp)) {
1783 req->chain_fsp = NULL;
1784 }
1785
1786 /*
1787 * Clear all possible chained fsp
1788 * pointers in the SMB2 request queue.
1789 */
1790 remove_smb2_chained_fsp(fsp);
1791 }
1792
1793 void file_free(struct smb_request *req, files_struct *fsp)
1794 {
1795 struct smbd_server_connection *sconn = fsp->conn->sconn;
1796 uint64_t fnum = fsp->fnum;
1797
1798 fsp_unbind_smb(req, fsp);
1799
1800 /* Drop all remaining extensions. */
1801 vfs_remove_all_fsp_extensions(fsp);
1802
1803 fsp_free(fsp);
1804
1805 DBG_INFO("freed files structure %"PRIu64" (%zu used)\n",
1806 fnum,
1807 sconn->num_files);
1808 }
1809
1810 /****************************************************************************
1811 Get an fsp from a packet given a 16 bit fnum.
1812 ****************************************************************************/
1813
1814 files_struct *file_fsp(struct smb_request *req, uint16_t fid)
1815 {
1816 struct smbXsrv_open *op;
1817 NTSTATUS status;
1818 NTTIME now = 0;
1819 files_struct *fsp;
1820
1821 if (req == NULL) {
1822 /*
1823 * We should never get here. req==NULL could in theory
1824 * only happen from internal opens with a non-zero
1825 * root_dir_fid. Internal opens just don't do that, at
1826 * least they are not supposed to do so. And if they
1827 * start to do so, they better fake up a smb_request
1828 * from which we get the right smbd_server_conn. While
1829 * this should never happen, let's return NULL here.
1830 */
1831 return NULL;
1832 }
1833
1834 if (req->chain_fsp != NULL) {
1835 if (req->chain_fsp->fsp_flags.closing) {
1836 return NULL;
1837 }
1838 return req->chain_fsp;
1839 }
1840
1841 if (req->xconn == NULL) {
1842 return NULL;
1843 }
1844
1845 now = timeval_to_nttime(&req->request_time);
1846
1847 status = smb1srv_open_lookup(req->xconn,
1848 fid, now, &op);
1849 if (!NT_STATUS_IS_OK(status)) {
1850 return NULL;
1851 }
1852
1853 fsp = op->compat;
1854 if (fsp == NULL) {
1855 return NULL;
1856 }
1857
1858 if (fsp->fsp_flags.closing) {
1859 return NULL;
1860 }
1861
1862 req->chain_fsp = fsp;
1863 fsp->fsp_name->st.cached_dos_attributes = FILE_ATTRIBUTES_INVALID;
1864 return fsp;
1865 }
1866
1867 struct files_struct *file_fsp_get(struct smbd_smb2_request *smb2req,
1868 uint64_t persistent_id,
1869 uint64_t volatile_id)
1870 {
1871 struct smbXsrv_open *op;
1872 NTSTATUS status;
1873 NTTIME now = 0;
1874 struct files_struct *fsp;
1875
1876 now = timeval_to_nttime(&smb2req->request_time);
1877
1878 status = smb2srv_open_lookup(smb2req->xconn,
1879 persistent_id, volatile_id,
1880 now, &op);
1881 if (!NT_STATUS_IS_OK(status)) {
1882 return NULL;
1883 }
1884
1885 fsp = op->compat;
1886 if (fsp == NULL) {
1887 return NULL;
1888 }
1889
1890 if (smb2req->tcon == NULL) {
1891 return NULL;
1892 }
1893
1894 if (smb2req->tcon->compat != fsp->conn) {
1895 return NULL;
1896 }
1897
1898 if (smb2req->session == NULL) {
1899 return NULL;
1900 }
1901
1902 if (smb2req->session->global->session_wire_id != fsp->vuid) {
1903 return NULL;
1904 }
1905
1906 if (fsp->fsp_flags.closing) {
1907 return NULL;
1908 }
1909
1910 fsp->fsp_name->st.cached_dos_attributes = FILE_ATTRIBUTES_INVALID;
1911
1912 return fsp;
1913 }
1914
1915 struct files_struct *file_fsp_smb2(struct smbd_smb2_request *smb2req,
1916 uint64_t persistent_id,
1917 uint64_t volatile_id)
1918 {
1919 struct files_struct *fsp;
1920
1921 if (smb2req->compat_chain_fsp != NULL) {
1922 if (smb2req->compat_chain_fsp->fsp_flags.closing) {
1923 return NULL;
1924 }
1925 smb2req->compat_chain_fsp->fsp_name->st.cached_dos_attributes =
1926 FILE_ATTRIBUTES_INVALID;
1927 return smb2req->compat_chain_fsp;
1928 }
1929
1930 fsp = file_fsp_get(smb2req, persistent_id, volatile_id);
1931 if (fsp == NULL) {
1932 return NULL;
1933 }
1934
1935 smb2req->compat_chain_fsp = fsp;
1936 return fsp;
1937 }
1938
1939 /****************************************************************************
1940 Duplicate the file handle part for a DOS or FCB open.
1941 ****************************************************************************/
1942
1943 NTSTATUS dup_file_fsp(
1944 files_struct *from,
1945 uint32_t access_mask,
1946 files_struct *to)
1947 {
1948 size_t new_refcount;
1949
1950 /* this can never happen for print files */
1951 SMB_ASSERT(from->print_file == NULL);
1952
1953 TALLOC_FREE(to->fh);
1954
1955 to->fh = from->fh;
1956 new_refcount = fh_get_refcount(to->fh) + 1;
1957 fh_set_refcount(to->fh, new_refcount);
1958
1959 to->file_id = from->file_id;
1960 to->initial_allocation_size = from->initial_allocation_size;
1961 to->file_pid = from->file_pid;
1962 to->vuid = from->vuid;
1963 to->open_time = from->open_time;
1964 to->access_mask = access_mask;
1965 to->oplock_type = from->oplock_type;
1966 to->fsp_flags.can_lock = from->fsp_flags.can_lock;
1967 to->fsp_flags.can_read = ((access_mask & FILE_READ_DATA) != 0);
1968 to->fsp_flags.can_write =
1969 CAN_WRITE(from->conn) &&
1970 ((access_mask & (FILE_WRITE_DATA | FILE_APPEND_DATA)) != 0);
1971 to->fsp_flags.modified = from->fsp_flags.modified;
1972 to->fsp_flags.is_directory = from->fsp_flags.is_directory;
1973 to->fsp_flags.aio_write_behind = from->fsp_flags.aio_write_behind;
1974 to->fsp_flags.is_fsa = from->fsp_flags.is_fsa;
1975 to->fsp_flags.is_pathref = from->fsp_flags.is_pathref;
1976 to->fsp_flags.have_proc_fds = from->fsp_flags.have_proc_fds;
1977 to->fsp_flags.is_dirfsp = from->fsp_flags.is_dirfsp;
1978
1979 return fsp_set_smb_fname(to, from->fsp_name);
1980 }
1981
1982 /**
1983 * Return a jenkins hash of a pathname on a connection.
1984 */
1985
1986 NTSTATUS file_name_hash(connection_struct *conn,
1987 const char *name, uint32_t *p_name_hash)
1988 {
1989 char tmpbuf[PATH_MAX];
1990 char *fullpath, *to_free;
1991 ssize_t len;
1992 TDB_DATA key;
1993
1994 /* Set the hash of the full pathname. */
1995
1996 if (name[0] == '/') {
1997 strlcpy(tmpbuf, name, sizeof(tmpbuf));
1998 fullpath = tmpbuf;
1999 len = strlen(fullpath);
2000 to_free = NULL;
2001 } else {
2002 len = full_path_tos(conn->connectpath,
2003 name,
2004 tmpbuf,
2005 sizeof(tmpbuf),
2006 &fullpath,
2007 &to_free);
2008 }
2009 if (len == -1) {
2010 return NT_STATUS_NO_MEMORY;
2011 }
2012 key = (TDB_DATA) { .dptr = (uint8_t *)fullpath, .dsize = len+1 };
2013 *p_name_hash = tdb_jenkins_hash(&key);
2014
2015 DEBUG(10,("file_name_hash: %s hash 0x%x\n",
2016 fullpath,
2017 (unsigned int)*p_name_hash ));
2018
2019 TALLOC_FREE(to_free);
2020 return NT_STATUS_OK;
2021 }
2022
2023 static NTSTATUS fsp_attach_smb_fname(struct files_struct *fsp,
2024 struct smb_filename **_smb_fname)
2025 {
2026 struct smb_filename *smb_fname_new = talloc_move(fsp, _smb_fname);
2027 const char *name_str = NULL;
2028 uint32_t name_hash = 0;
2029 NTSTATUS status;
2030
2031 name_str = smb_fname_str_dbg(smb_fname_new);
2032 if (name_str == NULL) {
2033 return NT_STATUS_NO_MEMORY;
2034 }
2035
2036 status = file_name_hash(fsp->conn,
2037 name_str,
2038 &name_hash);
2039 if (!NT_STATUS_IS_OK(status)) {
2040 return status;
2041 }
2042
2043 status = fsp_smb_fname_link(fsp,
2044 &smb_fname_new->fsp_link,
2045 &smb_fname_new->fsp);
2046 if (!NT_STATUS_IS_OK(status)) {
2047 return status;
2048 }
2049
2050 fsp->name_hash = name_hash;
2051 fsp->fsp_name = smb_fname_new;
2052 fsp->fsp_name->st.cached_dos_attributes = FILE_ATTRIBUTES_INVALID;
2053 *_smb_fname = NULL;
2054 return NT_STATUS_OK;
2055 }
2056
2057 /**
2058 * The only way that the fsp->fsp_name field should ever be set.
2059 */
2060 NTSTATUS fsp_set_smb_fname(struct files_struct *fsp,
2061 const struct smb_filename *smb_fname_in)
2062 {
2063 struct smb_filename *smb_fname_old = fsp->fsp_name;
2064 struct smb_filename *smb_fname_new = NULL;
2065 NTSTATUS status;
2066
2067 smb_fname_new = cp_smb_filename(fsp, smb_fname_in);
2068 if (smb_fname_new == NULL) {
2069 return NT_STATUS_NO_MEMORY;
2070 }
2071
2072 status = fsp_attach_smb_fname(fsp, &smb_fname_new);
2073 if (!NT_STATUS_IS_OK(status)) {
2074 TALLOC_FREE(smb_fname_new);
2075 return status;
2076 }
2077
2078 if (smb_fname_old != NULL) {
2079 smb_fname_fsp_unlink(smb_fname_old);
2080 TALLOC_FREE(smb_fname_old);
2081 }
2082
2083 return NT_STATUS_OK;
2084 }
2085
2086 size_t fsp_fullbasepath(struct files_struct *fsp, char *buf, size_t buflen)
2087 {
2088 int len = 0;
2089 char tmp_buf[1] = {'\0'};
2090
2091 /*
2092 * Don't pass NULL buffer to snprintf (to satisfy static checker)
2093 * Some callers will call this function with NULL for buf and
2094 * 0 for buflen in order to get length of fullbasepath (without
2095 * needing to allocate or write to buf)
2096 */
2097 if (buf == NULL) {
2098 buf = tmp_buf;
2099 SMB_ASSERT(buflen==0);
2100 }
2101
2102 len = snprintf(buf, buflen, "%s/%s", fsp->conn->connectpath,
2103 fsp->fsp_name->base_name);
2104 SMB_ASSERT(len>0);
2105
2106 return len;
2107 }
2108
2109 void fsp_set_base_fsp(struct files_struct *fsp, struct files_struct *base_fsp)
2110 {
2111 SMB_ASSERT(fsp->stream_fsp == NULL);
2112 if (base_fsp != NULL) {
2113 SMB_ASSERT(base_fsp->base_fsp == NULL);
2114 SMB_ASSERT(base_fsp->stream_fsp == NULL);
2115 }
2116
2117 if (fsp->base_fsp != NULL) {
2118 SMB_ASSERT(fsp->base_fsp->stream_fsp == fsp);
2119 fsp->base_fsp->stream_fsp = NULL;
2120 }
2121
2122 fsp->base_fsp = base_fsp;
2123 if (fsp->base_fsp != NULL) {
2124 fsp->base_fsp->stream_fsp = fsp;
2125 }
2126 }
2127
2128 bool fsp_is_alternate_stream(const struct files_struct *fsp)
2129 {
2130 return (fsp->base_fsp != NULL);
2131 }
2132
2133 struct files_struct *metadata_fsp(struct files_struct *fsp)
2134 {
2135 if (fsp_is_alternate_stream(fsp)) {
2136 return fsp->base_fsp;
2137 }
2138 return fsp;
2139 }
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