1 // SPDX-License-Identifier: LGPL-2.1
2 /*
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 */
8
9 #include <linux/slab.h>
10 #include <linux/ctype.h>
11 #include <linux/mempool.h>
12 #include <linux/vmalloc.h>
13 #include "cifspdu.h"
14 #include "cifsglob.h"
15 #include "cifsproto.h"
16 #include "cifs_debug.h"
17 #include "smberr.h"
18 #include "nterr.h"
19 #include "cifs_unicode.h"
20 #include "smb2pdu.h"
21 #include "cifsfs.h"
22 #ifdef CONFIG_CIFS_DFS_UPCALL
23 #include "dns_resolve.h"
24 #include "dfs_cache.h"
25 #include "dfs.h"
26 #endif
27 #include "fs_context.h"
28 #include "cached_dir.h"
29
30 extern mempool_t *cifs_sm_req_poolp;
31 extern mempool_t *cifs_req_poolp;
32
33 /* The xid serves as a useful identifier for each incoming vfs request,
34 in a similar way to the mid which is useful to track each sent smb,
35 and CurrentXid can also provide a running counter (although it
36 will eventually wrap past zero) of the total vfs operations handled
37 since the cifs fs was mounted */
38
39 unsigned int
_get_xid(void)40 _get_xid(void)
41 {
42 unsigned int xid;
43
44 spin_lock(&GlobalMid_Lock);
45 GlobalTotalActiveXid++;
46
47 /* keep high water mark for number of simultaneous ops in filesystem */
48 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
49 GlobalMaxActiveXid = GlobalTotalActiveXid;
50 if (GlobalTotalActiveXid > 65000)
51 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
52 xid = GlobalCurrentXid++;
53 spin_unlock(&GlobalMid_Lock);
54 return xid;
55 }
56
57 void
_free_xid(unsigned int xid)58 _free_xid(unsigned int xid)
59 {
60 spin_lock(&GlobalMid_Lock);
61 /* if (GlobalTotalActiveXid == 0)
62 BUG(); */
63 GlobalTotalActiveXid--;
64 spin_unlock(&GlobalMid_Lock);
65 }
66
67 struct cifs_ses *
sesInfoAlloc(void)68 sesInfoAlloc(void)
69 {
70 struct cifs_ses *ret_buf;
71
72 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
73 if (ret_buf) {
74 atomic_inc(&sesInfoAllocCount);
75 spin_lock_init(&ret_buf->ses_lock);
76 ret_buf->ses_status = SES_NEW;
77 ++ret_buf->ses_count;
78 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
79 INIT_LIST_HEAD(&ret_buf->tcon_list);
80 mutex_init(&ret_buf->session_mutex);
81 spin_lock_init(&ret_buf->iface_lock);
82 INIT_LIST_HEAD(&ret_buf->iface_list);
83 spin_lock_init(&ret_buf->chan_lock);
84 }
85 return ret_buf;
86 }
87
88 void
sesInfoFree(struct cifs_ses * buf_to_free)89 sesInfoFree(struct cifs_ses *buf_to_free)
90 {
91 struct cifs_server_iface *iface = NULL, *niface = NULL;
92
93 if (buf_to_free == NULL) {
94 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
95 return;
96 }
97
98 unload_nls(buf_to_free->local_nls);
99 atomic_dec(&sesInfoAllocCount);
100 kfree(buf_to_free->serverOS);
101 kfree(buf_to_free->serverDomain);
102 kfree(buf_to_free->serverNOS);
103 kfree_sensitive(buf_to_free->password);
104 kfree(buf_to_free->user_name);
105 kfree(buf_to_free->domainName);
106 kfree_sensitive(buf_to_free->auth_key.response);
107 spin_lock(&buf_to_free->iface_lock);
108 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list,
109 iface_head)
110 kref_put(&iface->refcount, release_iface);
111 spin_unlock(&buf_to_free->iface_lock);
112 kfree_sensitive(buf_to_free);
113 }
114
115 struct cifs_tcon *
tcon_info_alloc(bool dir_leases_enabled)116 tcon_info_alloc(bool dir_leases_enabled)
117 {
118 struct cifs_tcon *ret_buf;
119
120 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
121 if (!ret_buf)
122 return NULL;
123
124 if (dir_leases_enabled == true) {
125 ret_buf->cfids = init_cached_dirs();
126 if (!ret_buf->cfids) {
127 kfree(ret_buf);
128 return NULL;
129 }
130 }
131 /* else ret_buf->cfids is already set to NULL above */
132
133 atomic_inc(&tconInfoAllocCount);
134 ret_buf->status = TID_NEW;
135 ++ret_buf->tc_count;
136 spin_lock_init(&ret_buf->tc_lock);
137 INIT_LIST_HEAD(&ret_buf->openFileList);
138 INIT_LIST_HEAD(&ret_buf->tcon_list);
139 spin_lock_init(&ret_buf->open_file_lock);
140 spin_lock_init(&ret_buf->stat_lock);
141 atomic_set(&ret_buf->num_local_opens, 0);
142 atomic_set(&ret_buf->num_remote_opens, 0);
143 #ifdef CONFIG_CIFS_DFS_UPCALL
144 INIT_LIST_HEAD(&ret_buf->dfs_ses_list);
145 #endif
146
147 return ret_buf;
148 }
149
150 void
tconInfoFree(struct cifs_tcon * tcon)151 tconInfoFree(struct cifs_tcon *tcon)
152 {
153 if (tcon == NULL) {
154 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
155 return;
156 }
157 free_cached_dirs(tcon->cfids);
158 atomic_dec(&tconInfoAllocCount);
159 kfree(tcon->nativeFileSystem);
160 kfree_sensitive(tcon->password);
161 #ifdef CONFIG_CIFS_DFS_UPCALL
162 dfs_put_root_smb_sessions(&tcon->dfs_ses_list);
163 #endif
164 kfree(tcon->origin_fullpath);
165 kfree(tcon);
166 }
167
168 struct smb_hdr *
cifs_buf_get(void)169 cifs_buf_get(void)
170 {
171 struct smb_hdr *ret_buf = NULL;
172 /*
173 * SMB2 header is bigger than CIFS one - no problems to clean some
174 * more bytes for CIFS.
175 */
176 size_t buf_size = sizeof(struct smb2_hdr);
177
178 /*
179 * We could use negotiated size instead of max_msgsize -
180 * but it may be more efficient to always alloc same size
181 * albeit slightly larger than necessary and maxbuffersize
182 * defaults to this and can not be bigger.
183 */
184 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
185
186 /* clear the first few header bytes */
187 /* for most paths, more is cleared in header_assemble */
188 memset(ret_buf, 0, buf_size + 3);
189 atomic_inc(&buf_alloc_count);
190 #ifdef CONFIG_CIFS_STATS2
191 atomic_inc(&total_buf_alloc_count);
192 #endif /* CONFIG_CIFS_STATS2 */
193
194 return ret_buf;
195 }
196
197 void
cifs_buf_release(void * buf_to_free)198 cifs_buf_release(void *buf_to_free)
199 {
200 if (buf_to_free == NULL) {
201 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
202 return;
203 }
204 mempool_free(buf_to_free, cifs_req_poolp);
205
206 atomic_dec(&buf_alloc_count);
207 return;
208 }
209
210 struct smb_hdr *
cifs_small_buf_get(void)211 cifs_small_buf_get(void)
212 {
213 struct smb_hdr *ret_buf = NULL;
214
215 /* We could use negotiated size instead of max_msgsize -
216 but it may be more efficient to always alloc same size
217 albeit slightly larger than necessary and maxbuffersize
218 defaults to this and can not be bigger */
219 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
220 /* No need to clear memory here, cleared in header assemble */
221 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
222 atomic_inc(&small_buf_alloc_count);
223 #ifdef CONFIG_CIFS_STATS2
224 atomic_inc(&total_small_buf_alloc_count);
225 #endif /* CONFIG_CIFS_STATS2 */
226
227 return ret_buf;
228 }
229
230 void
cifs_small_buf_release(void * buf_to_free)231 cifs_small_buf_release(void *buf_to_free)
232 {
233
234 if (buf_to_free == NULL) {
235 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
236 return;
237 }
238 mempool_free(buf_to_free, cifs_sm_req_poolp);
239
240 atomic_dec(&small_buf_alloc_count);
241 return;
242 }
243
244 void
free_rsp_buf(int resp_buftype,void * rsp)245 free_rsp_buf(int resp_buftype, void *rsp)
246 {
247 if (resp_buftype == CIFS_SMALL_BUFFER)
248 cifs_small_buf_release(rsp);
249 else if (resp_buftype == CIFS_LARGE_BUFFER)
250 cifs_buf_release(rsp);
251 }
252
253 /* NB: MID can not be set if treeCon not passed in, in that
254 case it is responsbility of caller to set the mid */
255 void
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)256 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
257 const struct cifs_tcon *treeCon, int word_count
258 /* length of fixed section (word count) in two byte units */)
259 {
260 char *temp = (char *) buffer;
261
262 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
263
264 buffer->smb_buf_length = cpu_to_be32(
265 (2 * word_count) + sizeof(struct smb_hdr) -
266 4 /* RFC 1001 length field does not count */ +
267 2 /* for bcc field itself */) ;
268
269 buffer->Protocol[0] = 0xFF;
270 buffer->Protocol[1] = 'S';
271 buffer->Protocol[2] = 'M';
272 buffer->Protocol[3] = 'B';
273 buffer->Command = smb_command;
274 buffer->Flags = 0x00; /* case sensitive */
275 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
276 buffer->Pid = cpu_to_le16((__u16)current->tgid);
277 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
278 if (treeCon) {
279 buffer->Tid = treeCon->tid;
280 if (treeCon->ses) {
281 if (treeCon->ses->capabilities & CAP_UNICODE)
282 buffer->Flags2 |= SMBFLG2_UNICODE;
283 if (treeCon->ses->capabilities & CAP_STATUS32)
284 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
285
286 /* Uid is not converted */
287 buffer->Uid = treeCon->ses->Suid;
288 if (treeCon->ses->server)
289 buffer->Mid = get_next_mid(treeCon->ses->server);
290 }
291 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
292 buffer->Flags2 |= SMBFLG2_DFS;
293 if (treeCon->nocase)
294 buffer->Flags |= SMBFLG_CASELESS;
295 if ((treeCon->ses) && (treeCon->ses->server))
296 if (treeCon->ses->server->sign)
297 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
298 }
299
300 /* endian conversion of flags is now done just before sending */
301 buffer->WordCount = (char) word_count;
302 return;
303 }
304
305 static int
check_smb_hdr(struct smb_hdr * smb)306 check_smb_hdr(struct smb_hdr *smb)
307 {
308 /* does it have the right SMB "signature" ? */
309 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
310 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
311 *(unsigned int *)smb->Protocol);
312 return 1;
313 }
314
315 /* if it's a response then accept */
316 if (smb->Flags & SMBFLG_RESPONSE)
317 return 0;
318
319 /* only one valid case where server sends us request */
320 if (smb->Command == SMB_COM_LOCKING_ANDX)
321 return 0;
322
323 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
324 get_mid(smb));
325 return 1;
326 }
327
328 int
checkSMB(char * buf,unsigned int total_read,struct TCP_Server_Info * server)329 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
330 {
331 struct smb_hdr *smb = (struct smb_hdr *)buf;
332 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
333 __u32 clc_len; /* calculated length */
334 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
335 total_read, rfclen);
336
337 /* is this frame too small to even get to a BCC? */
338 if (total_read < 2 + sizeof(struct smb_hdr)) {
339 if ((total_read >= sizeof(struct smb_hdr) - 1)
340 && (smb->Status.CifsError != 0)) {
341 /* it's an error return */
342 smb->WordCount = 0;
343 /* some error cases do not return wct and bcc */
344 return 0;
345 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
346 (smb->WordCount == 0)) {
347 char *tmp = (char *)smb;
348 /* Need to work around a bug in two servers here */
349 /* First, check if the part of bcc they sent was zero */
350 if (tmp[sizeof(struct smb_hdr)] == 0) {
351 /* some servers return only half of bcc
352 * on simple responses (wct, bcc both zero)
353 * in particular have seen this on
354 * ulogoffX and FindClose. This leaves
355 * one byte of bcc potentially unitialized
356 */
357 /* zero rest of bcc */
358 tmp[sizeof(struct smb_hdr)+1] = 0;
359 return 0;
360 }
361 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
362 } else {
363 cifs_dbg(VFS, "Length less than smb header size\n");
364 }
365 return -EIO;
366 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
367 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
368 __func__, smb->WordCount);
369 return -EIO;
370 }
371
372 /* otherwise, there is enough to get to the BCC */
373 if (check_smb_hdr(smb))
374 return -EIO;
375 clc_len = smbCalcSize(smb);
376
377 if (4 + rfclen != total_read) {
378 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
379 rfclen);
380 return -EIO;
381 }
382
383 if (4 + rfclen != clc_len) {
384 __u16 mid = get_mid(smb);
385 /* check if bcc wrapped around for large read responses */
386 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
387 /* check if lengths match mod 64K */
388 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
389 return 0; /* bcc wrapped */
390 }
391 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
392 clc_len, 4 + rfclen, mid);
393
394 if (4 + rfclen < clc_len) {
395 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
396 rfclen, mid);
397 return -EIO;
398 } else if (rfclen > clc_len + 512) {
399 /*
400 * Some servers (Windows XP in particular) send more
401 * data than the lengths in the SMB packet would
402 * indicate on certain calls (byte range locks and
403 * trans2 find first calls in particular). While the
404 * client can handle such a frame by ignoring the
405 * trailing data, we choose limit the amount of extra
406 * data to 512 bytes.
407 */
408 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
409 rfclen, mid);
410 return -EIO;
411 }
412 }
413 return 0;
414 }
415
416 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)417 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
418 {
419 struct smb_hdr *buf = (struct smb_hdr *)buffer;
420 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
421 struct TCP_Server_Info *pserver;
422 struct cifs_ses *ses;
423 struct cifs_tcon *tcon;
424 struct cifsInodeInfo *pCifsInode;
425 struct cifsFileInfo *netfile;
426
427 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
428 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
429 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
430 struct smb_com_transaction_change_notify_rsp *pSMBr =
431 (struct smb_com_transaction_change_notify_rsp *)buf;
432 struct file_notify_information *pnotify;
433 __u32 data_offset = 0;
434 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
435
436 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
437 data_offset = le32_to_cpu(pSMBr->DataOffset);
438
439 if (data_offset >
440 len - sizeof(struct file_notify_information)) {
441 cifs_dbg(FYI, "Invalid data_offset %u\n",
442 data_offset);
443 return true;
444 }
445 pnotify = (struct file_notify_information *)
446 ((char *)&pSMBr->hdr.Protocol + data_offset);
447 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
448 pnotify->FileName, pnotify->Action);
449 /* cifs_dump_mem("Rcvd notify Data: ",buf,
450 sizeof(struct smb_hdr)+60); */
451 return true;
452 }
453 if (pSMBr->hdr.Status.CifsError) {
454 cifs_dbg(FYI, "notify err 0x%x\n",
455 pSMBr->hdr.Status.CifsError);
456 return true;
457 }
458 return false;
459 }
460 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
461 return false;
462 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
463 /* no sense logging error on invalid handle on oplock
464 break - harmless race between close request and oplock
465 break response is expected from time to time writing out
466 large dirty files cached on the client */
467 if ((NT_STATUS_INVALID_HANDLE) ==
468 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
469 cifs_dbg(FYI, "Invalid handle on oplock break\n");
470 return true;
471 } else if (ERRbadfid ==
472 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
473 return true;
474 } else {
475 return false; /* on valid oplock brk we get "request" */
476 }
477 }
478 if (pSMB->hdr.WordCount != 8)
479 return false;
480
481 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
482 pSMB->LockType, pSMB->OplockLevel);
483 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
484 return false;
485
486 /* If server is a channel, select the primary channel */
487 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv;
488
489 /* look up tcon based on tid & uid */
490 spin_lock(&cifs_tcp_ses_lock);
491 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
492 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
493 if (tcon->tid != buf->Tid)
494 continue;
495
496 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
497 spin_lock(&tcon->open_file_lock);
498 list_for_each_entry(netfile, &tcon->openFileList, tlist) {
499 if (pSMB->Fid != netfile->fid.netfid)
500 continue;
501
502 cifs_dbg(FYI, "file id match, oplock break\n");
503 pCifsInode = CIFS_I(d_inode(netfile->dentry));
504
505 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
506 &pCifsInode->flags);
507
508 netfile->oplock_epoch = 0;
509 netfile->oplock_level = pSMB->OplockLevel;
510 netfile->oplock_break_cancelled = false;
511 cifs_queue_oplock_break(netfile);
512
513 spin_unlock(&tcon->open_file_lock);
514 spin_unlock(&cifs_tcp_ses_lock);
515 return true;
516 }
517 spin_unlock(&tcon->open_file_lock);
518 spin_unlock(&cifs_tcp_ses_lock);
519 cifs_dbg(FYI, "No matching file for oplock break\n");
520 return true;
521 }
522 }
523 spin_unlock(&cifs_tcp_ses_lock);
524 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
525 return true;
526 }
527
528 void
dump_smb(void * buf,int smb_buf_length)529 dump_smb(void *buf, int smb_buf_length)
530 {
531 if (traceSMB == 0)
532 return;
533
534 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
535 smb_buf_length, true);
536 }
537
538 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)539 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
540 {
541 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
542 struct cifs_tcon *tcon = NULL;
543
544 if (cifs_sb->master_tlink)
545 tcon = cifs_sb_master_tcon(cifs_sb);
546
547 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
548 cifs_sb->mnt_cifs_serverino_autodisabled = true;
549 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
550 tcon ? tcon->tree_name : "new server");
551 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
552 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
553
554 }
555 }
556
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)557 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
558 {
559 oplock &= 0xF;
560
561 if (oplock == OPLOCK_EXCLUSIVE) {
562 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
563 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
564 &cinode->netfs.inode);
565 } else if (oplock == OPLOCK_READ) {
566 cinode->oplock = CIFS_CACHE_READ_FLG;
567 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
568 &cinode->netfs.inode);
569 } else
570 cinode->oplock = 0;
571 }
572
573 /*
574 * We wait for oplock breaks to be processed before we attempt to perform
575 * writes.
576 */
cifs_get_writer(struct cifsInodeInfo * cinode)577 int cifs_get_writer(struct cifsInodeInfo *cinode)
578 {
579 int rc;
580
581 start:
582 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
583 TASK_KILLABLE);
584 if (rc)
585 return rc;
586
587 spin_lock(&cinode->writers_lock);
588 if (!cinode->writers)
589 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
590 cinode->writers++;
591 /* Check to see if we have started servicing an oplock break */
592 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
593 cinode->writers--;
594 if (cinode->writers == 0) {
595 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
596 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
597 }
598 spin_unlock(&cinode->writers_lock);
599 goto start;
600 }
601 spin_unlock(&cinode->writers_lock);
602 return 0;
603 }
604
cifs_put_writer(struct cifsInodeInfo * cinode)605 void cifs_put_writer(struct cifsInodeInfo *cinode)
606 {
607 spin_lock(&cinode->writers_lock);
608 cinode->writers--;
609 if (cinode->writers == 0) {
610 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
611 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
612 }
613 spin_unlock(&cinode->writers_lock);
614 }
615
616 /**
617 * cifs_queue_oplock_break - queue the oplock break handler for cfile
618 * @cfile: The file to break the oplock on
619 *
620 * This function is called from the demultiplex thread when it
621 * receives an oplock break for @cfile.
622 *
623 * Assumes the tcon->open_file_lock is held.
624 * Assumes cfile->file_info_lock is NOT held.
625 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)626 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
627 {
628 /*
629 * Bump the handle refcount now while we hold the
630 * open_file_lock to enforce the validity of it for the oplock
631 * break handler. The matching put is done at the end of the
632 * handler.
633 */
634 cifsFileInfo_get(cfile);
635
636 queue_work(cifsoplockd_wq, &cfile->oplock_break);
637 }
638
cifs_done_oplock_break(struct cifsInodeInfo * cinode)639 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
640 {
641 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
642 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
643 }
644
645 bool
backup_cred(struct cifs_sb_info * cifs_sb)646 backup_cred(struct cifs_sb_info *cifs_sb)
647 {
648 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
649 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
650 return true;
651 }
652 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
653 if (in_group_p(cifs_sb->ctx->backupgid))
654 return true;
655 }
656
657 return false;
658 }
659
660 void
cifs_del_pending_open(struct cifs_pending_open * open)661 cifs_del_pending_open(struct cifs_pending_open *open)
662 {
663 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
664 list_del(&open->olist);
665 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
666 }
667
668 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)669 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
670 struct cifs_pending_open *open)
671 {
672 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
673 open->oplock = CIFS_OPLOCK_NO_CHANGE;
674 open->tlink = tlink;
675 fid->pending_open = open;
676 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
677 }
678
679 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)680 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
681 struct cifs_pending_open *open)
682 {
683 spin_lock(&tlink_tcon(tlink)->open_file_lock);
684 cifs_add_pending_open_locked(fid, tlink, open);
685 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
686 }
687
688 /*
689 * Critical section which runs after acquiring deferred_lock.
690 * As there is no reference count on cifs_deferred_close, pdclose
691 * should not be used outside deferred_lock.
692 */
693 bool
cifs_is_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close ** pdclose)694 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
695 {
696 struct cifs_deferred_close *dclose;
697
698 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
699 if ((dclose->netfid == cfile->fid.netfid) &&
700 (dclose->persistent_fid == cfile->fid.persistent_fid) &&
701 (dclose->volatile_fid == cfile->fid.volatile_fid)) {
702 *pdclose = dclose;
703 return true;
704 }
705 }
706 return false;
707 }
708
709 /*
710 * Critical section which runs after acquiring deferred_lock.
711 */
712 void
cifs_add_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close * dclose)713 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
714 {
715 bool is_deferred = false;
716 struct cifs_deferred_close *pdclose;
717
718 is_deferred = cifs_is_deferred_close(cfile, &pdclose);
719 if (is_deferred) {
720 kfree(dclose);
721 return;
722 }
723
724 dclose->tlink = cfile->tlink;
725 dclose->netfid = cfile->fid.netfid;
726 dclose->persistent_fid = cfile->fid.persistent_fid;
727 dclose->volatile_fid = cfile->fid.volatile_fid;
728 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
729 }
730
731 /*
732 * Critical section which runs after acquiring deferred_lock.
733 */
734 void
cifs_del_deferred_close(struct cifsFileInfo * cfile)735 cifs_del_deferred_close(struct cifsFileInfo *cfile)
736 {
737 bool is_deferred = false;
738 struct cifs_deferred_close *dclose;
739
740 is_deferred = cifs_is_deferred_close(cfile, &dclose);
741 if (!is_deferred)
742 return;
743 list_del(&dclose->dlist);
744 kfree(dclose);
745 }
746
747 void
cifs_close_deferred_file(struct cifsInodeInfo * cifs_inode)748 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
749 {
750 struct cifsFileInfo *cfile = NULL;
751 struct file_list *tmp_list, *tmp_next_list;
752 struct list_head file_head;
753
754 if (cifs_inode == NULL)
755 return;
756
757 INIT_LIST_HEAD(&file_head);
758 spin_lock(&cifs_inode->open_file_lock);
759 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
760 if (delayed_work_pending(&cfile->deferred)) {
761 if (cancel_delayed_work(&cfile->deferred)) {
762 spin_lock(&cifs_inode->deferred_lock);
763 cifs_del_deferred_close(cfile);
764 spin_unlock(&cifs_inode->deferred_lock);
765
766 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
767 if (tmp_list == NULL)
768 break;
769 tmp_list->cfile = cfile;
770 list_add_tail(&tmp_list->list, &file_head);
771 }
772 }
773 }
774 spin_unlock(&cifs_inode->open_file_lock);
775
776 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
777 _cifsFileInfo_put(tmp_list->cfile, false, false);
778 list_del(&tmp_list->list);
779 kfree(tmp_list);
780 }
781 }
782
783 void
cifs_close_all_deferred_files(struct cifs_tcon * tcon)784 cifs_close_all_deferred_files(struct cifs_tcon *tcon)
785 {
786 struct cifsFileInfo *cfile;
787 struct file_list *tmp_list, *tmp_next_list;
788 struct list_head file_head;
789
790 INIT_LIST_HEAD(&file_head);
791 spin_lock(&tcon->open_file_lock);
792 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
793 if (delayed_work_pending(&cfile->deferred)) {
794 if (cancel_delayed_work(&cfile->deferred)) {
795 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
796 cifs_del_deferred_close(cfile);
797 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
798
799 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
800 if (tmp_list == NULL)
801 break;
802 tmp_list->cfile = cfile;
803 list_add_tail(&tmp_list->list, &file_head);
804 }
805 }
806 }
807 spin_unlock(&tcon->open_file_lock);
808
809 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
810 _cifsFileInfo_put(tmp_list->cfile, true, false);
811 list_del(&tmp_list->list);
812 kfree(tmp_list);
813 }
814 }
815 void
cifs_close_deferred_file_under_dentry(struct cifs_tcon * tcon,const char * path)816 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
817 {
818 struct cifsFileInfo *cfile;
819 struct file_list *tmp_list, *tmp_next_list;
820 struct list_head file_head;
821 void *page;
822 const char *full_path;
823
824 INIT_LIST_HEAD(&file_head);
825 page = alloc_dentry_path();
826 spin_lock(&tcon->open_file_lock);
827 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
828 full_path = build_path_from_dentry(cfile->dentry, page);
829 if (strstr(full_path, path)) {
830 if (delayed_work_pending(&cfile->deferred)) {
831 if (cancel_delayed_work(&cfile->deferred)) {
832 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
833 cifs_del_deferred_close(cfile);
834 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
835
836 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
837 if (tmp_list == NULL)
838 break;
839 tmp_list->cfile = cfile;
840 list_add_tail(&tmp_list->list, &file_head);
841 }
842 }
843 }
844 }
845 spin_unlock(&tcon->open_file_lock);
846
847 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
848 _cifsFileInfo_put(tmp_list->cfile, true, false);
849 list_del(&tmp_list->list);
850 kfree(tmp_list);
851 }
852 free_dentry_path(page);
853 }
854
855 /* parses DFS referral V3 structure
856 * caller is responsible for freeing target_nodes
857 * returns:
858 * - on success - 0
859 * - on failure - errno
860 */
861 int
parse_dfs_referrals(struct get_dfs_referral_rsp * rsp,u32 rsp_size,unsigned int * num_of_nodes,struct dfs_info3_param ** target_nodes,const struct nls_table * nls_codepage,int remap,const char * searchName,bool is_unicode)862 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
863 unsigned int *num_of_nodes,
864 struct dfs_info3_param **target_nodes,
865 const struct nls_table *nls_codepage, int remap,
866 const char *searchName, bool is_unicode)
867 {
868 int i, rc = 0;
869 char *data_end;
870 struct dfs_referral_level_3 *ref;
871
872 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
873
874 if (*num_of_nodes < 1) {
875 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
876 *num_of_nodes);
877 rc = -EINVAL;
878 goto parse_DFS_referrals_exit;
879 }
880
881 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
882 if (ref->VersionNumber != cpu_to_le16(3)) {
883 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
884 le16_to_cpu(ref->VersionNumber));
885 rc = -EINVAL;
886 goto parse_DFS_referrals_exit;
887 }
888
889 /* get the upper boundary of the resp buffer */
890 data_end = (char *)rsp + rsp_size;
891
892 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
893 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
894
895 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
896 GFP_KERNEL);
897 if (*target_nodes == NULL) {
898 rc = -ENOMEM;
899 goto parse_DFS_referrals_exit;
900 }
901
902 /* collect necessary data from referrals */
903 for (i = 0; i < *num_of_nodes; i++) {
904 char *temp;
905 int max_len;
906 struct dfs_info3_param *node = (*target_nodes)+i;
907
908 node->flags = le32_to_cpu(rsp->DFSFlags);
909 if (is_unicode) {
910 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
911 GFP_KERNEL);
912 if (tmp == NULL) {
913 rc = -ENOMEM;
914 goto parse_DFS_referrals_exit;
915 }
916 cifsConvertToUTF16((__le16 *) tmp, searchName,
917 PATH_MAX, nls_codepage, remap);
918 node->path_consumed = cifs_utf16_bytes(tmp,
919 le16_to_cpu(rsp->PathConsumed),
920 nls_codepage);
921 kfree(tmp);
922 } else
923 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
924
925 node->server_type = le16_to_cpu(ref->ServerType);
926 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
927
928 /* copy DfsPath */
929 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
930 max_len = data_end - temp;
931 node->path_name = cifs_strndup_from_utf16(temp, max_len,
932 is_unicode, nls_codepage);
933 if (!node->path_name) {
934 rc = -ENOMEM;
935 goto parse_DFS_referrals_exit;
936 }
937
938 /* copy link target UNC */
939 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
940 max_len = data_end - temp;
941 node->node_name = cifs_strndup_from_utf16(temp, max_len,
942 is_unicode, nls_codepage);
943 if (!node->node_name) {
944 rc = -ENOMEM;
945 goto parse_DFS_referrals_exit;
946 }
947
948 node->ttl = le32_to_cpu(ref->TimeToLive);
949
950 ref++;
951 }
952
953 parse_DFS_referrals_exit:
954 if (rc) {
955 free_dfs_info_array(*target_nodes, *num_of_nodes);
956 *target_nodes = NULL;
957 *num_of_nodes = 0;
958 }
959 return rc;
960 }
961
962 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)963 cifs_aio_ctx_alloc(void)
964 {
965 struct cifs_aio_ctx *ctx;
966
967 /*
968 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
969 * to false so that we know when we have to unreference pages within
970 * cifs_aio_ctx_release()
971 */
972 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
973 if (!ctx)
974 return NULL;
975
976 INIT_LIST_HEAD(&ctx->list);
977 mutex_init(&ctx->aio_mutex);
978 init_completion(&ctx->done);
979 kref_init(&ctx->refcount);
980 return ctx;
981 }
982
983 void
cifs_aio_ctx_release(struct kref * refcount)984 cifs_aio_ctx_release(struct kref *refcount)
985 {
986 struct cifs_aio_ctx *ctx = container_of(refcount,
987 struct cifs_aio_ctx, refcount);
988
989 cifsFileInfo_put(ctx->cfile);
990
991 /*
992 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
993 * which means that iov_iter_extract_pages() was a success and thus
994 * that we may have references or pins on pages that we need to
995 * release.
996 */
997 if (ctx->bv) {
998 if (ctx->should_dirty || ctx->bv_need_unpin) {
999 unsigned int i;
1000
1001 for (i = 0; i < ctx->nr_pinned_pages; i++) {
1002 struct page *page = ctx->bv[i].bv_page;
1003
1004 if (ctx->should_dirty)
1005 set_page_dirty(page);
1006 if (ctx->bv_need_unpin)
1007 unpin_user_page(page);
1008 }
1009 }
1010 kvfree(ctx->bv);
1011 }
1012
1013 kfree(ctx);
1014 }
1015
1016 /**
1017 * cifs_alloc_hash - allocate hash and hash context together
1018 * @name: The name of the crypto hash algo
1019 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM
1020 *
1021 * The caller has to make sure @sdesc is initialized to either NULL or
1022 * a valid context. It can be freed via cifs_free_hash().
1023 */
1024 int
cifs_alloc_hash(const char * name,struct shash_desc ** sdesc)1025 cifs_alloc_hash(const char *name, struct shash_desc **sdesc)
1026 {
1027 int rc = 0;
1028 struct crypto_shash *alg = NULL;
1029
1030 if (*sdesc)
1031 return 0;
1032
1033 alg = crypto_alloc_shash(name, 0, 0);
1034 if (IS_ERR(alg)) {
1035 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name);
1036 rc = PTR_ERR(alg);
1037 *sdesc = NULL;
1038 return rc;
1039 }
1040
1041 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL);
1042 if (*sdesc == NULL) {
1043 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name);
1044 crypto_free_shash(alg);
1045 return -ENOMEM;
1046 }
1047
1048 (*sdesc)->tfm = alg;
1049 return 0;
1050 }
1051
1052 /**
1053 * cifs_free_hash - free hash and hash context together
1054 * @sdesc: Where to find the pointer to the hash TFM
1055 *
1056 * Freeing a NULL descriptor is safe.
1057 */
1058 void
cifs_free_hash(struct shash_desc ** sdesc)1059 cifs_free_hash(struct shash_desc **sdesc)
1060 {
1061 if (unlikely(!sdesc) || !*sdesc)
1062 return;
1063
1064 if ((*sdesc)->tfm) {
1065 crypto_free_shash((*sdesc)->tfm);
1066 (*sdesc)->tfm = NULL;
1067 }
1068
1069 kfree_sensitive(*sdesc);
1070 *sdesc = NULL;
1071 }
1072
extract_unc_hostname(const char * unc,const char ** h,size_t * len)1073 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
1074 {
1075 const char *end;
1076
1077 /* skip initial slashes */
1078 while (*unc && (*unc == '\\' || *unc == '/'))
1079 unc++;
1080
1081 end = unc;
1082
1083 while (*end && !(*end == '\\' || *end == '/'))
1084 end++;
1085
1086 *h = unc;
1087 *len = end - unc;
1088 }
1089
1090 /**
1091 * copy_path_name - copy src path to dst, possibly truncating
1092 * @dst: The destination buffer
1093 * @src: The source name
1094 *
1095 * returns number of bytes written (including trailing nul)
1096 */
copy_path_name(char * dst,const char * src)1097 int copy_path_name(char *dst, const char *src)
1098 {
1099 int name_len;
1100
1101 /*
1102 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1103 * will truncate and strlen(dst) will be PATH_MAX-1
1104 */
1105 name_len = strscpy(dst, src, PATH_MAX);
1106 if (WARN_ON_ONCE(name_len < 0))
1107 name_len = PATH_MAX-1;
1108
1109 /* we count the trailing nul */
1110 name_len++;
1111 return name_len;
1112 }
1113
1114 struct super_cb_data {
1115 void *data;
1116 struct super_block *sb;
1117 };
1118
tcon_super_cb(struct super_block * sb,void * arg)1119 static void tcon_super_cb(struct super_block *sb, void *arg)
1120 {
1121 struct super_cb_data *sd = arg;
1122 struct cifs_sb_info *cifs_sb;
1123 struct cifs_tcon *t1 = sd->data, *t2;
1124
1125 if (sd->sb)
1126 return;
1127
1128 cifs_sb = CIFS_SB(sb);
1129 t2 = cifs_sb_master_tcon(cifs_sb);
1130
1131 spin_lock(&t2->tc_lock);
1132 if (t1->ses == t2->ses &&
1133 t1->ses->server == t2->ses->server &&
1134 t2->origin_fullpath &&
1135 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath))
1136 sd->sb = sb;
1137 spin_unlock(&t2->tc_lock);
1138 }
1139
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)1140 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1141 void *data)
1142 {
1143 struct super_cb_data sd = {
1144 .data = data,
1145 .sb = NULL,
1146 };
1147 struct file_system_type **fs_type = (struct file_system_type *[]) {
1148 &cifs_fs_type, &smb3_fs_type, NULL,
1149 };
1150
1151 for (; *fs_type; fs_type++) {
1152 iterate_supers_type(*fs_type, f, &sd);
1153 if (sd.sb) {
1154 /*
1155 * Grab an active reference in order to prevent automounts (DFS links)
1156 * of expiring and then freeing up our cifs superblock pointer while
1157 * we're doing failover.
1158 */
1159 cifs_sb_active(sd.sb);
1160 return sd.sb;
1161 }
1162 }
1163 pr_warn_once("%s: could not find dfs superblock\n", __func__);
1164 return ERR_PTR(-EINVAL);
1165 }
1166
__cifs_put_super(struct super_block * sb)1167 static void __cifs_put_super(struct super_block *sb)
1168 {
1169 if (!IS_ERR_OR_NULL(sb))
1170 cifs_sb_deactive(sb);
1171 }
1172
cifs_get_dfs_tcon_super(struct cifs_tcon * tcon)1173 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon)
1174 {
1175 spin_lock(&tcon->tc_lock);
1176 if (!tcon->origin_fullpath) {
1177 spin_unlock(&tcon->tc_lock);
1178 return ERR_PTR(-ENOENT);
1179 }
1180 spin_unlock(&tcon->tc_lock);
1181 return __cifs_get_super(tcon_super_cb, tcon);
1182 }
1183
cifs_put_tcp_super(struct super_block * sb)1184 void cifs_put_tcp_super(struct super_block *sb)
1185 {
1186 __cifs_put_super(sb);
1187 }
1188
1189 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * share,size_t share_len,bool * result)1190 int match_target_ip(struct TCP_Server_Info *server,
1191 const char *share, size_t share_len,
1192 bool *result)
1193 {
1194 int rc;
1195 char *target;
1196 struct sockaddr_storage ss;
1197
1198 *result = false;
1199
1200 target = kzalloc(share_len + 3, GFP_KERNEL);
1201 if (!target)
1202 return -ENOMEM;
1203
1204 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1205
1206 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1207
1208 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL);
1209 kfree(target);
1210
1211 if (rc < 0)
1212 return rc;
1213
1214 spin_lock(&server->srv_lock);
1215 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
1216 spin_unlock(&server->srv_lock);
1217 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1218 return 0;
1219 }
1220
cifs_update_super_prepath(struct cifs_sb_info * cifs_sb,char * prefix)1221 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
1222 {
1223 int rc;
1224
1225 kfree(cifs_sb->prepath);
1226 cifs_sb->prepath = NULL;
1227
1228 if (prefix && *prefix) {
1229 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC);
1230 if (IS_ERR(cifs_sb->prepath)) {
1231 rc = PTR_ERR(cifs_sb->prepath);
1232 cifs_sb->prepath = NULL;
1233 return rc;
1234 }
1235 if (cifs_sb->prepath)
1236 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1237 }
1238
1239 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1240 return 0;
1241 }
1242
1243 /*
1244 * Handle weird Windows SMB server behaviour. It responds with
1245 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for
1246 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains
1247 * non-ASCII unicode symbols.
1248 */
cifs_inval_name_dfs_link_error(const unsigned int xid,struct cifs_tcon * tcon,struct cifs_sb_info * cifs_sb,const char * full_path,bool * islink)1249 int cifs_inval_name_dfs_link_error(const unsigned int xid,
1250 struct cifs_tcon *tcon,
1251 struct cifs_sb_info *cifs_sb,
1252 const char *full_path,
1253 bool *islink)
1254 {
1255 struct cifs_ses *ses = tcon->ses;
1256 size_t len;
1257 char *path;
1258 char *ref_path;
1259
1260 *islink = false;
1261
1262 /*
1263 * Fast path - skip check when @full_path doesn't have a prefix path to
1264 * look up or tcon is not DFS.
1265 */
1266 if (strlen(full_path) < 2 || !cifs_sb ||
1267 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
1268 !is_tcon_dfs(tcon))
1269 return 0;
1270
1271 spin_lock(&tcon->tc_lock);
1272 if (!tcon->origin_fullpath) {
1273 spin_unlock(&tcon->tc_lock);
1274 return 0;
1275 }
1276 spin_unlock(&tcon->tc_lock);
1277
1278 /*
1279 * Slow path - tcon is DFS and @full_path has prefix path, so attempt
1280 * to get a referral to figure out whether it is an DFS link.
1281 */
1282 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1;
1283 path = kmalloc(len, GFP_KERNEL);
1284 if (!path)
1285 return -ENOMEM;
1286
1287 scnprintf(path, len, "%s%s", tcon->tree_name, full_path);
1288 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls,
1289 cifs_remap(cifs_sb));
1290 kfree(path);
1291
1292 if (IS_ERR(ref_path)) {
1293 if (PTR_ERR(ref_path) != -EINVAL)
1294 return PTR_ERR(ref_path);
1295 } else {
1296 struct dfs_info3_param *refs = NULL;
1297 int num_refs = 0;
1298
1299 /*
1300 * XXX: we are not using dfs_cache_find() here because we might
1301 * end up filling all the DFS cache and thus potentially
1302 * removing cached DFS targets that the client would eventually
1303 * need during failover.
1304 */
1305 ses = CIFS_DFS_ROOT_SES(ses);
1306 if (ses->server->ops->get_dfs_refer &&
1307 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs,
1308 &num_refs, cifs_sb->local_nls,
1309 cifs_remap(cifs_sb)))
1310 *islink = refs[0].server_type == DFS_TYPE_LINK;
1311 free_dfs_info_array(refs, num_refs);
1312 kfree(ref_path);
1313 }
1314 return 0;
1315 }
1316 #endif
1317
cifs_wait_for_server_reconnect(struct TCP_Server_Info * server,bool retry)1318 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry)
1319 {
1320 int timeout = 10;
1321 int rc;
1322
1323 spin_lock(&server->srv_lock);
1324 if (server->tcpStatus != CifsNeedReconnect) {
1325 spin_unlock(&server->srv_lock);
1326 return 0;
1327 }
1328 timeout *= server->nr_targets;
1329 spin_unlock(&server->srv_lock);
1330
1331 /*
1332 * Give demultiplex thread up to 10 seconds to each target available for
1333 * reconnect -- should be greater than cifs socket timeout which is 7
1334 * seconds.
1335 *
1336 * On "soft" mounts we wait once. Hard mounts keep retrying until
1337 * process is killed or server comes back on-line.
1338 */
1339 do {
1340 rc = wait_event_interruptible_timeout(server->response_q,
1341 (server->tcpStatus != CifsNeedReconnect),
1342 timeout * HZ);
1343 if (rc < 0) {
1344 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n",
1345 __func__);
1346 return -ERESTARTSYS;
1347 }
1348
1349 /* are we still trying to reconnect? */
1350 spin_lock(&server->srv_lock);
1351 if (server->tcpStatus != CifsNeedReconnect) {
1352 spin_unlock(&server->srv_lock);
1353 return 0;
1354 }
1355 spin_unlock(&server->srv_lock);
1356 } while (retry);
1357
1358 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__);
1359 return -EHOSTDOWN;
1360 }
1361