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