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 /* The xid serves as a useful identifier for each incoming vfs request,
31 in a similar way to the mid which is useful to track each sent smb,
32 and CurrentXid can also provide a running counter (although it
33 will eventually wrap past zero) of the total vfs operations handled
34 since the cifs fs was mounted */
35
36 unsigned int
_get_xid(void)37 _get_xid(void)
38 {
39 unsigned int xid;
40
41 spin_lock(&GlobalMid_Lock);
42 GlobalTotalActiveXid++;
43
44 /* keep high water mark for number of simultaneous ops in filesystem */
45 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
46 GlobalMaxActiveXid = GlobalTotalActiveXid;
47 if (GlobalTotalActiveXid > 65000)
48 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
49 xid = GlobalCurrentXid++;
50 spin_unlock(&GlobalMid_Lock);
51 return xid;
52 }
53
54 void
_free_xid(unsigned int xid)55 _free_xid(unsigned int xid)
56 {
57 spin_lock(&GlobalMid_Lock);
58 /* if (GlobalTotalActiveXid == 0)
59 BUG(); */
60 GlobalTotalActiveXid--;
61 spin_unlock(&GlobalMid_Lock);
62 }
63
64 struct cifs_ses *
sesInfoAlloc(void)65 sesInfoAlloc(void)
66 {
67 struct cifs_ses *ret_buf;
68
69 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
70 if (ret_buf) {
71 atomic_inc(&sesInfoAllocCount);
72 spin_lock_init(&ret_buf->ses_lock);
73 ret_buf->ses_status = SES_NEW;
74 ++ret_buf->ses_count;
75 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
76 INIT_LIST_HEAD(&ret_buf->tcon_list);
77 mutex_init(&ret_buf->session_mutex);
78 spin_lock_init(&ret_buf->iface_lock);
79 INIT_LIST_HEAD(&ret_buf->iface_list);
80 spin_lock_init(&ret_buf->chan_lock);
81 }
82 return ret_buf;
83 }
84
85 void
sesInfoFree(struct cifs_ses * buf_to_free)86 sesInfoFree(struct cifs_ses *buf_to_free)
87 {
88 struct cifs_server_iface *iface = NULL, *niface = NULL;
89
90 if (buf_to_free == NULL) {
91 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
92 return;
93 }
94
95 unload_nls(buf_to_free->local_nls);
96 atomic_dec(&sesInfoAllocCount);
97 kfree(buf_to_free->serverOS);
98 kfree(buf_to_free->serverDomain);
99 kfree(buf_to_free->serverNOS);
100 kfree_sensitive(buf_to_free->password);
101 kfree_sensitive(buf_to_free->password2);
102 kfree(buf_to_free->user_name);
103 kfree(buf_to_free->domainName);
104 kfree_sensitive(buf_to_free->auth_key.response);
105 spin_lock(&buf_to_free->iface_lock);
106 list_for_each_entry_safe(iface, niface, &buf_to_free->iface_list,
107 iface_head)
108 kref_put(&iface->refcount, release_iface);
109 spin_unlock(&buf_to_free->iface_lock);
110 kfree_sensitive(buf_to_free);
111 }
112
113 struct cifs_tcon *
tcon_info_alloc(bool dir_leases_enabled,enum smb3_tcon_ref_trace trace)114 tcon_info_alloc(bool dir_leases_enabled, enum smb3_tcon_ref_trace trace)
115 {
116 struct cifs_tcon *ret_buf;
117 static atomic_t tcon_debug_id;
118
119 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
120 if (!ret_buf)
121 return NULL;
122
123 if (dir_leases_enabled == true) {
124 ret_buf->cfids = init_cached_dirs();
125 if (!ret_buf->cfids) {
126 kfree(ret_buf);
127 return NULL;
128 }
129 }
130 /* else ret_buf->cfids is already set to NULL above */
131
132 atomic_inc(&tconInfoAllocCount);
133 ret_buf->status = TID_NEW;
134 ret_buf->debug_id = atomic_inc_return(&tcon_debug_id);
135 ret_buf->tc_count = 1;
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 ret_buf->stats_from_time = ktime_get_real_seconds();
144 #ifdef CONFIG_CIFS_FSCACHE
145 mutex_init(&ret_buf->fscache_lock);
146 #endif
147 trace_smb3_tcon_ref(ret_buf->debug_id, ret_buf->tc_count, trace);
148 #ifdef CONFIG_CIFS_DFS_UPCALL
149 INIT_LIST_HEAD(&ret_buf->dfs_ses_list);
150 #endif
151
152 return ret_buf;
153 }
154
155 void
tconInfoFree(struct cifs_tcon * tcon,enum smb3_tcon_ref_trace trace)156 tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
157 {
158 if (tcon == NULL) {
159 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
160 return;
161 }
162 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace);
163 free_cached_dirs(tcon->cfids);
164 atomic_dec(&tconInfoAllocCount);
165 kfree(tcon->nativeFileSystem);
166 kfree_sensitive(tcon->password);
167 kfree(tcon->origin_fullpath);
168 kfree(tcon);
169 }
170
171 struct smb_hdr *
cifs_buf_get(void)172 cifs_buf_get(void)
173 {
174 struct smb_hdr *ret_buf = NULL;
175 /*
176 * SMB2 header is bigger than CIFS one - no problems to clean some
177 * more bytes for CIFS.
178 */
179 size_t buf_size = sizeof(struct smb2_hdr);
180
181 /*
182 * We could use negotiated size instead of max_msgsize -
183 * but it may be more efficient to always alloc same size
184 * albeit slightly larger than necessary and maxbuffersize
185 * defaults to this and can not be bigger.
186 */
187 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
188
189 /* clear the first few header bytes */
190 /* for most paths, more is cleared in header_assemble */
191 memset(ret_buf, 0, buf_size + 3);
192 atomic_inc(&buf_alloc_count);
193 #ifdef CONFIG_CIFS_STATS2
194 atomic_inc(&total_buf_alloc_count);
195 #endif /* CONFIG_CIFS_STATS2 */
196
197 return ret_buf;
198 }
199
200 void
cifs_buf_release(void * buf_to_free)201 cifs_buf_release(void *buf_to_free)
202 {
203 if (buf_to_free == NULL) {
204 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
205 return;
206 }
207 mempool_free(buf_to_free, cifs_req_poolp);
208
209 atomic_dec(&buf_alloc_count);
210 return;
211 }
212
213 struct smb_hdr *
cifs_small_buf_get(void)214 cifs_small_buf_get(void)
215 {
216 struct smb_hdr *ret_buf = NULL;
217
218 /* We could use negotiated size instead of max_msgsize -
219 but it may be more efficient to always alloc same size
220 albeit slightly larger than necessary and maxbuffersize
221 defaults to this and can not be bigger */
222 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
223 /* No need to clear memory here, cleared in header assemble */
224 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
225 atomic_inc(&small_buf_alloc_count);
226 #ifdef CONFIG_CIFS_STATS2
227 atomic_inc(&total_small_buf_alloc_count);
228 #endif /* CONFIG_CIFS_STATS2 */
229
230 return ret_buf;
231 }
232
233 void
cifs_small_buf_release(void * buf_to_free)234 cifs_small_buf_release(void *buf_to_free)
235 {
236
237 if (buf_to_free == NULL) {
238 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
239 return;
240 }
241 mempool_free(buf_to_free, cifs_sm_req_poolp);
242
243 atomic_dec(&small_buf_alloc_count);
244 return;
245 }
246
247 void
free_rsp_buf(int resp_buftype,void * rsp)248 free_rsp_buf(int resp_buftype, void *rsp)
249 {
250 if (resp_buftype == CIFS_SMALL_BUFFER)
251 cifs_small_buf_release(rsp);
252 else if (resp_buftype == CIFS_LARGE_BUFFER)
253 cifs_buf_release(rsp);
254 }
255
256 /* NB: MID can not be set if treeCon not passed in, in that
257 case it is responsibility of caller to set the mid */
258 void
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)259 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
260 const struct cifs_tcon *treeCon, int word_count
261 /* length of fixed section (word count) in two byte units */)
262 {
263 char *temp = (char *) buffer;
264
265 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
266
267 buffer->smb_buf_length = cpu_to_be32(
268 (2 * word_count) + sizeof(struct smb_hdr) -
269 4 /* RFC 1001 length field does not count */ +
270 2 /* for bcc field itself */) ;
271
272 buffer->Protocol[0] = 0xFF;
273 buffer->Protocol[1] = 'S';
274 buffer->Protocol[2] = 'M';
275 buffer->Protocol[3] = 'B';
276 buffer->Command = smb_command;
277 buffer->Flags = 0x00; /* case sensitive */
278 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
279 buffer->Pid = cpu_to_le16((__u16)current->tgid);
280 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
281 if (treeCon) {
282 buffer->Tid = treeCon->tid;
283 if (treeCon->ses) {
284 if (treeCon->ses->capabilities & CAP_UNICODE)
285 buffer->Flags2 |= SMBFLG2_UNICODE;
286 if (treeCon->ses->capabilities & CAP_STATUS32)
287 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
288
289 /* Uid is not converted */
290 buffer->Uid = treeCon->ses->Suid;
291 if (treeCon->ses->server)
292 buffer->Mid = get_next_mid(treeCon->ses->server);
293 }
294 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
295 buffer->Flags2 |= SMBFLG2_DFS;
296 if (treeCon->nocase)
297 buffer->Flags |= SMBFLG_CASELESS;
298 if ((treeCon->ses) && (treeCon->ses->server))
299 if (treeCon->ses->server->sign)
300 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
301 }
302
303 /* endian conversion of flags is now done just before sending */
304 buffer->WordCount = (char) word_count;
305 return;
306 }
307
308 static int
check_smb_hdr(struct smb_hdr * smb)309 check_smb_hdr(struct smb_hdr *smb)
310 {
311 /* does it have the right SMB "signature" ? */
312 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
313 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
314 *(unsigned int *)smb->Protocol);
315 return 1;
316 }
317
318 /* if it's a response then accept */
319 if (smb->Flags & SMBFLG_RESPONSE)
320 return 0;
321
322 /* only one valid case where server sends us request */
323 if (smb->Command == SMB_COM_LOCKING_ANDX)
324 return 0;
325
326 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
327 get_mid(smb));
328 return 1;
329 }
330
331 int
checkSMB(char * buf,unsigned int total_read,struct TCP_Server_Info * server)332 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
333 {
334 struct smb_hdr *smb = (struct smb_hdr *)buf;
335 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
336 __u32 clc_len; /* calculated length */
337 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
338 total_read, rfclen);
339
340 /* is this frame too small to even get to a BCC? */
341 if (total_read < 2 + sizeof(struct smb_hdr)) {
342 if ((total_read >= sizeof(struct smb_hdr) - 1)
343 && (smb->Status.CifsError != 0)) {
344 /* it's an error return */
345 smb->WordCount = 0;
346 /* some error cases do not return wct and bcc */
347 return 0;
348 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
349 (smb->WordCount == 0)) {
350 char *tmp = (char *)smb;
351 /* Need to work around a bug in two servers here */
352 /* First, check if the part of bcc they sent was zero */
353 if (tmp[sizeof(struct smb_hdr)] == 0) {
354 /* some servers return only half of bcc
355 * on simple responses (wct, bcc both zero)
356 * in particular have seen this on
357 * ulogoffX and FindClose. This leaves
358 * one byte of bcc potentially uninitialized
359 */
360 /* zero rest of bcc */
361 tmp[sizeof(struct smb_hdr)+1] = 0;
362 return 0;
363 }
364 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
365 } else {
366 cifs_dbg(VFS, "Length less than smb header size\n");
367 }
368 return -EIO;
369 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
370 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
371 __func__, smb->WordCount);
372 return -EIO;
373 }
374
375 /* otherwise, there is enough to get to the BCC */
376 if (check_smb_hdr(smb))
377 return -EIO;
378 clc_len = smbCalcSize(smb);
379
380 if (4 + rfclen != total_read) {
381 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
382 rfclen);
383 return -EIO;
384 }
385
386 if (4 + rfclen != clc_len) {
387 __u16 mid = get_mid(smb);
388 /* check if bcc wrapped around for large read responses */
389 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
390 /* check if lengths match mod 64K */
391 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
392 return 0; /* bcc wrapped */
393 }
394 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
395 clc_len, 4 + rfclen, mid);
396
397 if (4 + rfclen < clc_len) {
398 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
399 rfclen, mid);
400 return -EIO;
401 } else if (rfclen > clc_len + 512) {
402 /*
403 * Some servers (Windows XP in particular) send more
404 * data than the lengths in the SMB packet would
405 * indicate on certain calls (byte range locks and
406 * trans2 find first calls in particular). While the
407 * client can handle such a frame by ignoring the
408 * trailing data, we choose limit the amount of extra
409 * data to 512 bytes.
410 */
411 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
412 rfclen, mid);
413 return -EIO;
414 }
415 }
416 return 0;
417 }
418
419 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)420 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
421 {
422 struct smb_hdr *buf = (struct smb_hdr *)buffer;
423 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
424 struct TCP_Server_Info *pserver;
425 struct cifs_ses *ses;
426 struct cifs_tcon *tcon;
427 struct cifsInodeInfo *pCifsInode;
428 struct cifsFileInfo *netfile;
429
430 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
431 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
432 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
433 struct smb_com_transaction_change_notify_rsp *pSMBr =
434 (struct smb_com_transaction_change_notify_rsp *)buf;
435 struct file_notify_information *pnotify;
436 __u32 data_offset = 0;
437 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
438
439 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
440 data_offset = le32_to_cpu(pSMBr->DataOffset);
441
442 if (data_offset >
443 len - sizeof(struct file_notify_information)) {
444 cifs_dbg(FYI, "Invalid data_offset %u\n",
445 data_offset);
446 return true;
447 }
448 pnotify = (struct file_notify_information *)
449 ((char *)&pSMBr->hdr.Protocol + data_offset);
450 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
451 pnotify->FileName, pnotify->Action);
452 /* cifs_dump_mem("Rcvd notify Data: ",buf,
453 sizeof(struct smb_hdr)+60); */
454 return true;
455 }
456 if (pSMBr->hdr.Status.CifsError) {
457 cifs_dbg(FYI, "notify err 0x%x\n",
458 pSMBr->hdr.Status.CifsError);
459 return true;
460 }
461 return false;
462 }
463 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
464 return false;
465 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
466 /* no sense logging error on invalid handle on oplock
467 break - harmless race between close request and oplock
468 break response is expected from time to time writing out
469 large dirty files cached on the client */
470 if ((NT_STATUS_INVALID_HANDLE) ==
471 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
472 cifs_dbg(FYI, "Invalid handle on oplock break\n");
473 return true;
474 } else if (ERRbadfid ==
475 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
476 return true;
477 } else {
478 return false; /* on valid oplock brk we get "request" */
479 }
480 }
481 if (pSMB->hdr.WordCount != 8)
482 return false;
483
484 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
485 pSMB->LockType, pSMB->OplockLevel);
486 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
487 return false;
488
489 /* If server is a channel, select the primary channel */
490 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv;
491
492 /* look up tcon based on tid & uid */
493 spin_lock(&cifs_tcp_ses_lock);
494 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
495 if (cifs_ses_exiting(ses))
496 continue;
497 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
498 if (tcon->tid != buf->Tid)
499 continue;
500
501 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
502 spin_lock(&tcon->open_file_lock);
503 list_for_each_entry(netfile, &tcon->openFileList, tlist) {
504 if (pSMB->Fid != netfile->fid.netfid)
505 continue;
506
507 cifs_dbg(FYI, "file id match, oplock break\n");
508 pCifsInode = CIFS_I(d_inode(netfile->dentry));
509
510 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
511 &pCifsInode->flags);
512
513 netfile->oplock_epoch = 0;
514 netfile->oplock_level = pSMB->OplockLevel;
515 netfile->oplock_break_cancelled = false;
516 cifs_queue_oplock_break(netfile);
517
518 spin_unlock(&tcon->open_file_lock);
519 spin_unlock(&cifs_tcp_ses_lock);
520 return true;
521 }
522 spin_unlock(&tcon->open_file_lock);
523 spin_unlock(&cifs_tcp_ses_lock);
524 cifs_dbg(FYI, "No matching file for oplock break\n");
525 return true;
526 }
527 }
528 spin_unlock(&cifs_tcp_ses_lock);
529 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
530 return true;
531 }
532
533 void
dump_smb(void * buf,int smb_buf_length)534 dump_smb(void *buf, int smb_buf_length)
535 {
536 if (traceSMB == 0)
537 return;
538
539 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
540 smb_buf_length, true);
541 }
542
543 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)544 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
545 {
546 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
547 struct cifs_tcon *tcon = NULL;
548
549 if (cifs_sb->master_tlink)
550 tcon = cifs_sb_master_tcon(cifs_sb);
551
552 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
553 cifs_sb->mnt_cifs_serverino_autodisabled = true;
554 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
555 tcon ? tcon->tree_name : "new server");
556 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
557 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
558
559 }
560 }
561
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)562 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
563 {
564 oplock &= 0xF;
565
566 if (oplock == OPLOCK_EXCLUSIVE) {
567 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
568 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
569 &cinode->netfs.inode);
570 } else if (oplock == OPLOCK_READ) {
571 cinode->oplock = CIFS_CACHE_READ_FLG;
572 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
573 &cinode->netfs.inode);
574 } else
575 cinode->oplock = 0;
576 }
577
578 /*
579 * We wait for oplock breaks to be processed before we attempt to perform
580 * writes.
581 */
cifs_get_writer(struct cifsInodeInfo * cinode)582 int cifs_get_writer(struct cifsInodeInfo *cinode)
583 {
584 int rc;
585
586 start:
587 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
588 TASK_KILLABLE);
589 if (rc)
590 return rc;
591
592 spin_lock(&cinode->writers_lock);
593 if (!cinode->writers)
594 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
595 cinode->writers++;
596 /* Check to see if we have started servicing an oplock break */
597 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
598 cinode->writers--;
599 if (cinode->writers == 0) {
600 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
601 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
602 }
603 spin_unlock(&cinode->writers_lock);
604 goto start;
605 }
606 spin_unlock(&cinode->writers_lock);
607 return 0;
608 }
609
cifs_put_writer(struct cifsInodeInfo * cinode)610 void cifs_put_writer(struct cifsInodeInfo *cinode)
611 {
612 spin_lock(&cinode->writers_lock);
613 cinode->writers--;
614 if (cinode->writers == 0) {
615 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
616 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
617 }
618 spin_unlock(&cinode->writers_lock);
619 }
620
621 /**
622 * cifs_queue_oplock_break - queue the oplock break handler for cfile
623 * @cfile: The file to break the oplock on
624 *
625 * This function is called from the demultiplex thread when it
626 * receives an oplock break for @cfile.
627 *
628 * Assumes the tcon->open_file_lock is held.
629 * Assumes cfile->file_info_lock is NOT held.
630 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)631 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
632 {
633 /*
634 * Bump the handle refcount now while we hold the
635 * open_file_lock to enforce the validity of it for the oplock
636 * break handler. The matching put is done at the end of the
637 * handler.
638 */
639 cifsFileInfo_get(cfile);
640
641 queue_work(cifsoplockd_wq, &cfile->oplock_break);
642 }
643
cifs_done_oplock_break(struct cifsInodeInfo * cinode)644 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
645 {
646 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
647 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
648 }
649
650 bool
backup_cred(struct cifs_sb_info * cifs_sb)651 backup_cred(struct cifs_sb_info *cifs_sb)
652 {
653 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
654 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
655 return true;
656 }
657 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
658 if (in_group_p(cifs_sb->ctx->backupgid))
659 return true;
660 }
661
662 return false;
663 }
664
665 void
cifs_del_pending_open(struct cifs_pending_open * open)666 cifs_del_pending_open(struct cifs_pending_open *open)
667 {
668 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
669 list_del(&open->olist);
670 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
671 }
672
673 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)674 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
675 struct cifs_pending_open *open)
676 {
677 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
678 open->oplock = CIFS_OPLOCK_NO_CHANGE;
679 open->tlink = tlink;
680 fid->pending_open = open;
681 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
682 }
683
684 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)685 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
686 struct cifs_pending_open *open)
687 {
688 spin_lock(&tlink_tcon(tlink)->open_file_lock);
689 cifs_add_pending_open_locked(fid, tlink, open);
690 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
691 }
692
693 /*
694 * Critical section which runs after acquiring deferred_lock.
695 * As there is no reference count on cifs_deferred_close, pdclose
696 * should not be used outside deferred_lock.
697 */
698 bool
cifs_is_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close ** pdclose)699 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
700 {
701 struct cifs_deferred_close *dclose;
702
703 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
704 if ((dclose->netfid == cfile->fid.netfid) &&
705 (dclose->persistent_fid == cfile->fid.persistent_fid) &&
706 (dclose->volatile_fid == cfile->fid.volatile_fid)) {
707 *pdclose = dclose;
708 return true;
709 }
710 }
711 return false;
712 }
713
714 /*
715 * Critical section which runs after acquiring deferred_lock.
716 */
717 void
cifs_add_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close * dclose)718 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
719 {
720 bool is_deferred = false;
721 struct cifs_deferred_close *pdclose;
722
723 is_deferred = cifs_is_deferred_close(cfile, &pdclose);
724 if (is_deferred) {
725 kfree(dclose);
726 return;
727 }
728
729 dclose->tlink = cfile->tlink;
730 dclose->netfid = cfile->fid.netfid;
731 dclose->persistent_fid = cfile->fid.persistent_fid;
732 dclose->volatile_fid = cfile->fid.volatile_fid;
733 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
734 }
735
736 /*
737 * Critical section which runs after acquiring deferred_lock.
738 */
739 void
cifs_del_deferred_close(struct cifsFileInfo * cfile)740 cifs_del_deferred_close(struct cifsFileInfo *cfile)
741 {
742 bool is_deferred = false;
743 struct cifs_deferred_close *dclose;
744
745 is_deferred = cifs_is_deferred_close(cfile, &dclose);
746 if (!is_deferred)
747 return;
748 list_del(&dclose->dlist);
749 kfree(dclose);
750 }
751
752 void
cifs_close_deferred_file(struct cifsInodeInfo * cifs_inode)753 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
754 {
755 struct cifsFileInfo *cfile = NULL;
756 struct file_list *tmp_list, *tmp_next_list;
757 LIST_HEAD(file_head);
758
759 if (cifs_inode == NULL)
760 return;
761
762 spin_lock(&cifs_inode->open_file_lock);
763 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
764 if (delayed_work_pending(&cfile->deferred)) {
765 if (cancel_delayed_work(&cfile->deferred)) {
766 spin_lock(&cifs_inode->deferred_lock);
767 cifs_del_deferred_close(cfile);
768 spin_unlock(&cifs_inode->deferred_lock);
769
770 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
771 if (tmp_list == NULL)
772 break;
773 tmp_list->cfile = cfile;
774 list_add_tail(&tmp_list->list, &file_head);
775 }
776 }
777 }
778 spin_unlock(&cifs_inode->open_file_lock);
779
780 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
781 _cifsFileInfo_put(tmp_list->cfile, false, false);
782 list_del(&tmp_list->list);
783 kfree(tmp_list);
784 }
785 }
786
787 void
cifs_close_all_deferred_files(struct cifs_tcon * tcon)788 cifs_close_all_deferred_files(struct cifs_tcon *tcon)
789 {
790 struct cifsFileInfo *cfile;
791 struct file_list *tmp_list, *tmp_next_list;
792 LIST_HEAD(file_head);
793
794 spin_lock(&tcon->open_file_lock);
795 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
796 if (delayed_work_pending(&cfile->deferred)) {
797 if (cancel_delayed_work(&cfile->deferred)) {
798 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
799 cifs_del_deferred_close(cfile);
800 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
801
802 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
803 if (tmp_list == NULL)
804 break;
805 tmp_list->cfile = cfile;
806 list_add_tail(&tmp_list->list, &file_head);
807 }
808 }
809 }
810 spin_unlock(&tcon->open_file_lock);
811
812 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
813 _cifsFileInfo_put(tmp_list->cfile, true, false);
814 list_del(&tmp_list->list);
815 kfree(tmp_list);
816 }
817 }
818 void
cifs_close_deferred_file_under_dentry(struct cifs_tcon * tcon,const char * path)819 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
820 {
821 struct cifsFileInfo *cfile;
822 struct file_list *tmp_list, *tmp_next_list;
823 void *page;
824 const char *full_path;
825 LIST_HEAD(file_head);
826
827 page = alloc_dentry_path();
828 spin_lock(&tcon->open_file_lock);
829 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
830 full_path = build_path_from_dentry(cfile->dentry, page);
831 if (strstr(full_path, path)) {
832 if (delayed_work_pending(&cfile->deferred)) {
833 if (cancel_delayed_work(&cfile->deferred)) {
834 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
835 cifs_del_deferred_close(cfile);
836 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
837
838 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
839 if (tmp_list == NULL)
840 break;
841 tmp_list->cfile = cfile;
842 list_add_tail(&tmp_list->list, &file_head);
843 }
844 }
845 }
846 }
847 spin_unlock(&tcon->open_file_lock);
848
849 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
850 _cifsFileInfo_put(tmp_list->cfile, true, false);
851 list_del(&tmp_list->list);
852 kfree(tmp_list);
853 }
854 free_dentry_path(page);
855 }
856
857 /*
858 * If a dentry has been deleted, all corresponding open handles should know that
859 * so that we do not defer close them.
860 */
cifs_mark_open_handles_for_deleted_file(struct inode * inode,const char * path)861 void cifs_mark_open_handles_for_deleted_file(struct inode *inode,
862 const char *path)
863 {
864 struct cifsFileInfo *cfile;
865 void *page;
866 const char *full_path;
867 struct cifsInodeInfo *cinode = CIFS_I(inode);
868
869 page = alloc_dentry_path();
870 spin_lock(&cinode->open_file_lock);
871
872 /*
873 * note: we need to construct path from dentry and compare only if the
874 * inode has any hardlinks. When number of hardlinks is 1, we can just
875 * mark all open handles since they are going to be from the same file.
876 */
877 if (inode->i_nlink > 1) {
878 list_for_each_entry(cfile, &cinode->openFileList, flist) {
879 full_path = build_path_from_dentry(cfile->dentry, page);
880 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0)
881 cfile->status_file_deleted = true;
882 }
883 } else {
884 list_for_each_entry(cfile, &cinode->openFileList, flist)
885 cfile->status_file_deleted = true;
886 }
887 spin_unlock(&cinode->open_file_lock);
888 free_dentry_path(page);
889 }
890
891 /* parses DFS referral V3 structure
892 * caller is responsible for freeing target_nodes
893 * returns:
894 * - on success - 0
895 * - on failure - errno
896 */
897 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)898 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
899 unsigned int *num_of_nodes,
900 struct dfs_info3_param **target_nodes,
901 const struct nls_table *nls_codepage, int remap,
902 const char *searchName, bool is_unicode)
903 {
904 int i, rc = 0;
905 char *data_end;
906 struct dfs_referral_level_3 *ref;
907
908 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
909
910 if (*num_of_nodes < 1) {
911 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
912 *num_of_nodes);
913 rc = -EINVAL;
914 goto parse_DFS_referrals_exit;
915 }
916
917 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
918 if (ref->VersionNumber != cpu_to_le16(3)) {
919 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
920 le16_to_cpu(ref->VersionNumber));
921 rc = -EINVAL;
922 goto parse_DFS_referrals_exit;
923 }
924
925 /* get the upper boundary of the resp buffer */
926 data_end = (char *)rsp + rsp_size;
927
928 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
929 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
930
931 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
932 GFP_KERNEL);
933 if (*target_nodes == NULL) {
934 rc = -ENOMEM;
935 goto parse_DFS_referrals_exit;
936 }
937
938 /* collect necessary data from referrals */
939 for (i = 0; i < *num_of_nodes; i++) {
940 char *temp;
941 int max_len;
942 struct dfs_info3_param *node = (*target_nodes)+i;
943
944 node->flags = le32_to_cpu(rsp->DFSFlags);
945 if (is_unicode) {
946 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
947 GFP_KERNEL);
948 if (tmp == NULL) {
949 rc = -ENOMEM;
950 goto parse_DFS_referrals_exit;
951 }
952 cifsConvertToUTF16((__le16 *) tmp, searchName,
953 PATH_MAX, nls_codepage, remap);
954 node->path_consumed = cifs_utf16_bytes(tmp,
955 le16_to_cpu(rsp->PathConsumed),
956 nls_codepage);
957 kfree(tmp);
958 } else
959 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
960
961 node->server_type = le16_to_cpu(ref->ServerType);
962 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
963
964 /* copy DfsPath */
965 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
966 max_len = data_end - temp;
967 node->path_name = cifs_strndup_from_utf16(temp, max_len,
968 is_unicode, nls_codepage);
969 if (!node->path_name) {
970 rc = -ENOMEM;
971 goto parse_DFS_referrals_exit;
972 }
973
974 /* copy link target UNC */
975 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
976 max_len = data_end - temp;
977 node->node_name = cifs_strndup_from_utf16(temp, max_len,
978 is_unicode, nls_codepage);
979 if (!node->node_name) {
980 rc = -ENOMEM;
981 goto parse_DFS_referrals_exit;
982 }
983
984 node->ttl = le32_to_cpu(ref->TimeToLive);
985
986 ref++;
987 }
988
989 parse_DFS_referrals_exit:
990 if (rc) {
991 free_dfs_info_array(*target_nodes, *num_of_nodes);
992 *target_nodes = NULL;
993 *num_of_nodes = 0;
994 }
995 return rc;
996 }
997
998 /**
999 * cifs_alloc_hash - allocate hash and hash context together
1000 * @name: The name of the crypto hash algo
1001 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM
1002 *
1003 * The caller has to make sure @sdesc is initialized to either NULL or
1004 * a valid context. It can be freed via cifs_free_hash().
1005 */
1006 int
cifs_alloc_hash(const char * name,struct shash_desc ** sdesc)1007 cifs_alloc_hash(const char *name, struct shash_desc **sdesc)
1008 {
1009 int rc = 0;
1010 struct crypto_shash *alg = NULL;
1011
1012 if (*sdesc)
1013 return 0;
1014
1015 alg = crypto_alloc_shash(name, 0, 0);
1016 if (IS_ERR(alg)) {
1017 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name);
1018 rc = PTR_ERR(alg);
1019 *sdesc = NULL;
1020 return rc;
1021 }
1022
1023 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL);
1024 if (*sdesc == NULL) {
1025 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name);
1026 crypto_free_shash(alg);
1027 return -ENOMEM;
1028 }
1029
1030 (*sdesc)->tfm = alg;
1031 return 0;
1032 }
1033
1034 /**
1035 * cifs_free_hash - free hash and hash context together
1036 * @sdesc: Where to find the pointer to the hash TFM
1037 *
1038 * Freeing a NULL descriptor is safe.
1039 */
1040 void
cifs_free_hash(struct shash_desc ** sdesc)1041 cifs_free_hash(struct shash_desc **sdesc)
1042 {
1043 if (unlikely(!sdesc) || !*sdesc)
1044 return;
1045
1046 if ((*sdesc)->tfm) {
1047 crypto_free_shash((*sdesc)->tfm);
1048 (*sdesc)->tfm = NULL;
1049 }
1050
1051 kfree_sensitive(*sdesc);
1052 *sdesc = NULL;
1053 }
1054
extract_unc_hostname(const char * unc,const char ** h,size_t * len)1055 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
1056 {
1057 const char *end;
1058
1059 /* skip initial slashes */
1060 while (*unc && (*unc == '\\' || *unc == '/'))
1061 unc++;
1062
1063 end = unc;
1064
1065 while (*end && !(*end == '\\' || *end == '/'))
1066 end++;
1067
1068 *h = unc;
1069 *len = end - unc;
1070 }
1071
1072 /**
1073 * copy_path_name - copy src path to dst, possibly truncating
1074 * @dst: The destination buffer
1075 * @src: The source name
1076 *
1077 * returns number of bytes written (including trailing nul)
1078 */
copy_path_name(char * dst,const char * src)1079 int copy_path_name(char *dst, const char *src)
1080 {
1081 int name_len;
1082
1083 /*
1084 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1085 * will truncate and strlen(dst) will be PATH_MAX-1
1086 */
1087 name_len = strscpy(dst, src, PATH_MAX);
1088 if (WARN_ON_ONCE(name_len < 0))
1089 name_len = PATH_MAX-1;
1090
1091 /* we count the trailing nul */
1092 name_len++;
1093 return name_len;
1094 }
1095
1096 struct super_cb_data {
1097 void *data;
1098 struct super_block *sb;
1099 };
1100
tcon_super_cb(struct super_block * sb,void * arg)1101 static void tcon_super_cb(struct super_block *sb, void *arg)
1102 {
1103 struct super_cb_data *sd = arg;
1104 struct cifs_sb_info *cifs_sb;
1105 struct cifs_tcon *t1 = sd->data, *t2;
1106
1107 if (sd->sb)
1108 return;
1109
1110 cifs_sb = CIFS_SB(sb);
1111 t2 = cifs_sb_master_tcon(cifs_sb);
1112
1113 spin_lock(&t2->tc_lock);
1114 if ((t1->ses == t2->ses ||
1115 t1->ses->dfs_root_ses == t2->ses->dfs_root_ses) &&
1116 t1->ses->server == t2->ses->server &&
1117 t2->origin_fullpath &&
1118 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath))
1119 sd->sb = sb;
1120 spin_unlock(&t2->tc_lock);
1121 }
1122
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)1123 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1124 void *data)
1125 {
1126 struct super_cb_data sd = {
1127 .data = data,
1128 .sb = NULL,
1129 };
1130 struct file_system_type **fs_type = (struct file_system_type *[]) {
1131 &cifs_fs_type, &smb3_fs_type, NULL,
1132 };
1133
1134 for (; *fs_type; fs_type++) {
1135 iterate_supers_type(*fs_type, f, &sd);
1136 if (sd.sb) {
1137 /*
1138 * Grab an active reference in order to prevent automounts (DFS links)
1139 * of expiring and then freeing up our cifs superblock pointer while
1140 * we're doing failover.
1141 */
1142 cifs_sb_active(sd.sb);
1143 return sd.sb;
1144 }
1145 }
1146 pr_warn_once("%s: could not find dfs superblock\n", __func__);
1147 return ERR_PTR(-EINVAL);
1148 }
1149
__cifs_put_super(struct super_block * sb)1150 static void __cifs_put_super(struct super_block *sb)
1151 {
1152 if (!IS_ERR_OR_NULL(sb))
1153 cifs_sb_deactive(sb);
1154 }
1155
cifs_get_dfs_tcon_super(struct cifs_tcon * tcon)1156 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon)
1157 {
1158 spin_lock(&tcon->tc_lock);
1159 if (!tcon->origin_fullpath) {
1160 spin_unlock(&tcon->tc_lock);
1161 return ERR_PTR(-ENOENT);
1162 }
1163 spin_unlock(&tcon->tc_lock);
1164 return __cifs_get_super(tcon_super_cb, tcon);
1165 }
1166
cifs_put_tcp_super(struct super_block * sb)1167 void cifs_put_tcp_super(struct super_block *sb)
1168 {
1169 __cifs_put_super(sb);
1170 }
1171
1172 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * share,size_t share_len,bool * result)1173 int match_target_ip(struct TCP_Server_Info *server,
1174 const char *share, size_t share_len,
1175 bool *result)
1176 {
1177 int rc;
1178 char *target;
1179 struct sockaddr_storage ss;
1180
1181 *result = false;
1182
1183 target = kzalloc(share_len + 3, GFP_KERNEL);
1184 if (!target)
1185 return -ENOMEM;
1186
1187 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1188
1189 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1190
1191 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL);
1192 kfree(target);
1193
1194 if (rc < 0)
1195 return rc;
1196
1197 spin_lock(&server->srv_lock);
1198 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
1199 spin_unlock(&server->srv_lock);
1200 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1201 return 0;
1202 }
1203
cifs_update_super_prepath(struct cifs_sb_info * cifs_sb,char * prefix)1204 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
1205 {
1206 int rc;
1207
1208 kfree(cifs_sb->prepath);
1209 cifs_sb->prepath = NULL;
1210
1211 if (prefix && *prefix) {
1212 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC);
1213 if (IS_ERR(cifs_sb->prepath)) {
1214 rc = PTR_ERR(cifs_sb->prepath);
1215 cifs_sb->prepath = NULL;
1216 return rc;
1217 }
1218 if (cifs_sb->prepath)
1219 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1220 }
1221
1222 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1223 return 0;
1224 }
1225
1226 /*
1227 * Handle weird Windows SMB server behaviour. It responds with
1228 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for
1229 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains
1230 * non-ASCII unicode symbols.
1231 */
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)1232 int cifs_inval_name_dfs_link_error(const unsigned int xid,
1233 struct cifs_tcon *tcon,
1234 struct cifs_sb_info *cifs_sb,
1235 const char *full_path,
1236 bool *islink)
1237 {
1238 struct TCP_Server_Info *server = tcon->ses->server;
1239 struct cifs_ses *ses = tcon->ses;
1240 size_t len;
1241 char *path;
1242 char *ref_path;
1243
1244 *islink = false;
1245
1246 /*
1247 * Fast path - skip check when @full_path doesn't have a prefix path to
1248 * look up or tcon is not DFS.
1249 */
1250 if (strlen(full_path) < 2 || !cifs_sb ||
1251 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
1252 !is_tcon_dfs(tcon))
1253 return 0;
1254
1255 spin_lock(&server->srv_lock);
1256 if (!server->leaf_fullpath) {
1257 spin_unlock(&server->srv_lock);
1258 return 0;
1259 }
1260 spin_unlock(&server->srv_lock);
1261
1262 /*
1263 * Slow path - tcon is DFS and @full_path has prefix path, so attempt
1264 * to get a referral to figure out whether it is an DFS link.
1265 */
1266 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1;
1267 path = kmalloc(len, GFP_KERNEL);
1268 if (!path)
1269 return -ENOMEM;
1270
1271 scnprintf(path, len, "%s%s", tcon->tree_name, full_path);
1272 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls,
1273 cifs_remap(cifs_sb));
1274 kfree(path);
1275
1276 if (IS_ERR(ref_path)) {
1277 if (PTR_ERR(ref_path) != -EINVAL)
1278 return PTR_ERR(ref_path);
1279 } else {
1280 struct dfs_info3_param *refs = NULL;
1281 int num_refs = 0;
1282
1283 /*
1284 * XXX: we are not using dfs_cache_find() here because we might
1285 * end up filling all the DFS cache and thus potentially
1286 * removing cached DFS targets that the client would eventually
1287 * need during failover.
1288 */
1289 ses = CIFS_DFS_ROOT_SES(ses);
1290 if (ses->server->ops->get_dfs_refer &&
1291 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs,
1292 &num_refs, cifs_sb->local_nls,
1293 cifs_remap(cifs_sb)))
1294 *islink = refs[0].server_type == DFS_TYPE_LINK;
1295 free_dfs_info_array(refs, num_refs);
1296 kfree(ref_path);
1297 }
1298 return 0;
1299 }
1300 #endif
1301
cifs_wait_for_server_reconnect(struct TCP_Server_Info * server,bool retry)1302 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry)
1303 {
1304 int timeout = 10;
1305 int rc;
1306
1307 spin_lock(&server->srv_lock);
1308 if (server->tcpStatus != CifsNeedReconnect) {
1309 spin_unlock(&server->srv_lock);
1310 return 0;
1311 }
1312 timeout *= server->nr_targets;
1313 spin_unlock(&server->srv_lock);
1314
1315 /*
1316 * Give demultiplex thread up to 10 seconds to each target available for
1317 * reconnect -- should be greater than cifs socket timeout which is 7
1318 * seconds.
1319 *
1320 * On "soft" mounts we wait once. Hard mounts keep retrying until
1321 * process is killed or server comes back on-line.
1322 */
1323 do {
1324 rc = wait_event_interruptible_timeout(server->response_q,
1325 (server->tcpStatus != CifsNeedReconnect),
1326 timeout * HZ);
1327 if (rc < 0) {
1328 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n",
1329 __func__);
1330 return -ERESTARTSYS;
1331 }
1332
1333 /* are we still trying to reconnect? */
1334 spin_lock(&server->srv_lock);
1335 if (server->tcpStatus != CifsNeedReconnect) {
1336 spin_unlock(&server->srv_lock);
1337 return 0;
1338 }
1339 spin_unlock(&server->srv_lock);
1340 } while (retry);
1341
1342 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__);
1343 return -EHOSTDOWN;
1344 }
1345