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
149 return ret_buf;
150 }
151
152 void
tconInfoFree(struct cifs_tcon * tcon,enum smb3_tcon_ref_trace trace)153 tconInfoFree(struct cifs_tcon *tcon, enum smb3_tcon_ref_trace trace)
154 {
155 if (tcon == NULL) {
156 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
157 return;
158 }
159 trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count, trace);
160 free_cached_dirs(tcon->cfids);
161 atomic_dec(&tconInfoAllocCount);
162 kfree(tcon->nativeFileSystem);
163 kfree_sensitive(tcon->password);
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 /*
324 * Windows NT server returns error resposne (e.g. STATUS_DELETE_PENDING
325 * or STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile or any other)
326 * for some TRANS2 requests without the RESPONSE flag set in header.
327 */
328 if (smb->Command == SMB_COM_TRANSACTION2 && smb->Status.CifsError != 0)
329 return 0;
330
331 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
332 get_mid(smb));
333 return 1;
334 }
335
336 int
checkSMB(char * buf,unsigned int total_read,struct TCP_Server_Info * server)337 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
338 {
339 struct smb_hdr *smb = (struct smb_hdr *)buf;
340 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
341 __u32 clc_len; /* calculated length */
342 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
343 total_read, rfclen);
344
345 /* is this frame too small to even get to a BCC? */
346 if (total_read < 2 + sizeof(struct smb_hdr)) {
347 if ((total_read >= sizeof(struct smb_hdr) - 1)
348 && (smb->Status.CifsError != 0)) {
349 /* it's an error return */
350 smb->WordCount = 0;
351 /* some error cases do not return wct and bcc */
352 return 0;
353 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
354 (smb->WordCount == 0)) {
355 char *tmp = (char *)smb;
356 /* Need to work around a bug in two servers here */
357 /* First, check if the part of bcc they sent was zero */
358 if (tmp[sizeof(struct smb_hdr)] == 0) {
359 /* some servers return only half of bcc
360 * on simple responses (wct, bcc both zero)
361 * in particular have seen this on
362 * ulogoffX and FindClose. This leaves
363 * one byte of bcc potentially unitialized
364 */
365 /* zero rest of bcc */
366 tmp[sizeof(struct smb_hdr)+1] = 0;
367 return 0;
368 }
369 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
370 } else {
371 cifs_dbg(VFS, "Length less than smb header size\n");
372 }
373 return -EIO;
374 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
375 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
376 __func__, smb->WordCount);
377 return -EIO;
378 }
379
380 /* otherwise, there is enough to get to the BCC */
381 if (check_smb_hdr(smb))
382 return -EIO;
383 clc_len = smbCalcSize(smb);
384
385 if (4 + rfclen != total_read) {
386 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
387 rfclen);
388 return -EIO;
389 }
390
391 if (4 + rfclen != clc_len) {
392 __u16 mid = get_mid(smb);
393 /* check if bcc wrapped around for large read responses */
394 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
395 /* check if lengths match mod 64K */
396 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
397 return 0; /* bcc wrapped */
398 }
399 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
400 clc_len, 4 + rfclen, mid);
401
402 if (4 + rfclen < clc_len) {
403 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
404 rfclen, mid);
405 return -EIO;
406 } else if (rfclen > clc_len + 512) {
407 /*
408 * Some servers (Windows XP in particular) send more
409 * data than the lengths in the SMB packet would
410 * indicate on certain calls (byte range locks and
411 * trans2 find first calls in particular). While the
412 * client can handle such a frame by ignoring the
413 * trailing data, we choose limit the amount of extra
414 * data to 512 bytes.
415 */
416 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
417 rfclen, mid);
418 return -EIO;
419 }
420 }
421 return 0;
422 }
423
424 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)425 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
426 {
427 struct smb_hdr *buf = (struct smb_hdr *)buffer;
428 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
429 struct TCP_Server_Info *pserver;
430 struct cifs_ses *ses;
431 struct cifs_tcon *tcon;
432 struct cifsInodeInfo *pCifsInode;
433 struct cifsFileInfo *netfile;
434
435 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
436 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
437 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
438 struct smb_com_transaction_change_notify_rsp *pSMBr =
439 (struct smb_com_transaction_change_notify_rsp *)buf;
440 struct file_notify_information *pnotify;
441 __u32 data_offset = 0;
442 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
443
444 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
445 data_offset = le32_to_cpu(pSMBr->DataOffset);
446
447 if (data_offset >
448 len - sizeof(struct file_notify_information)) {
449 cifs_dbg(FYI, "Invalid data_offset %u\n",
450 data_offset);
451 return true;
452 }
453 pnotify = (struct file_notify_information *)
454 ((char *)&pSMBr->hdr.Protocol + data_offset);
455 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
456 pnotify->FileName, pnotify->Action);
457 /* cifs_dump_mem("Rcvd notify Data: ",buf,
458 sizeof(struct smb_hdr)+60); */
459 return true;
460 }
461 if (pSMBr->hdr.Status.CifsError) {
462 cifs_dbg(FYI, "notify err 0x%x\n",
463 pSMBr->hdr.Status.CifsError);
464 return true;
465 }
466 return false;
467 }
468 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
469 return false;
470 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
471 /* no sense logging error on invalid handle on oplock
472 break - harmless race between close request and oplock
473 break response is expected from time to time writing out
474 large dirty files cached on the client */
475 if ((NT_STATUS_INVALID_HANDLE) ==
476 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
477 cifs_dbg(FYI, "Invalid handle on oplock break\n");
478 return true;
479 } else if (ERRbadfid ==
480 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
481 return true;
482 } else {
483 return false; /* on valid oplock brk we get "request" */
484 }
485 }
486 if (pSMB->hdr.WordCount != 8)
487 return false;
488
489 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
490 pSMB->LockType, pSMB->OplockLevel);
491 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
492 return false;
493
494 /* If server is a channel, select the primary channel */
495 pserver = SERVER_IS_CHAN(srv) ? srv->primary_server : srv;
496
497 /* look up tcon based on tid & uid */
498 spin_lock(&cifs_tcp_ses_lock);
499 list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
500 if (cifs_ses_exiting(ses))
501 continue;
502 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
503 if (tcon->tid != buf->Tid)
504 continue;
505
506 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
507 spin_lock(&tcon->open_file_lock);
508 list_for_each_entry(netfile, &tcon->openFileList, tlist) {
509 if (pSMB->Fid != netfile->fid.netfid)
510 continue;
511
512 cifs_dbg(FYI, "file id match, oplock break\n");
513 pCifsInode = CIFS_I(d_inode(netfile->dentry));
514
515 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
516 &pCifsInode->flags);
517
518 netfile->oplock_epoch = 0;
519 netfile->oplock_level = pSMB->OplockLevel;
520 netfile->oplock_break_cancelled = false;
521 cifs_queue_oplock_break(netfile);
522
523 spin_unlock(&tcon->open_file_lock);
524 spin_unlock(&cifs_tcp_ses_lock);
525 return true;
526 }
527 spin_unlock(&tcon->open_file_lock);
528 spin_unlock(&cifs_tcp_ses_lock);
529 cifs_dbg(FYI, "No matching file for oplock break\n");
530 return true;
531 }
532 }
533 spin_unlock(&cifs_tcp_ses_lock);
534 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
535 return true;
536 }
537
538 void
dump_smb(void * buf,int smb_buf_length)539 dump_smb(void *buf, int smb_buf_length)
540 {
541 if (traceSMB == 0)
542 return;
543
544 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
545 smb_buf_length, true);
546 }
547
548 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)549 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
550 {
551 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
552 struct cifs_tcon *tcon = NULL;
553
554 if (cifs_sb->master_tlink)
555 tcon = cifs_sb_master_tcon(cifs_sb);
556
557 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
558 cifs_sb->mnt_cifs_serverino_autodisabled = true;
559 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
560 tcon ? tcon->tree_name : "new server");
561 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
562 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
563
564 }
565 }
566
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)567 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
568 {
569 oplock &= 0xF;
570
571 if (oplock == OPLOCK_EXCLUSIVE) {
572 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
573 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
574 &cinode->netfs.inode);
575 } else if (oplock == OPLOCK_READ) {
576 cinode->oplock = CIFS_CACHE_READ_FLG;
577 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
578 &cinode->netfs.inode);
579 } else
580 cinode->oplock = 0;
581 }
582
583 /*
584 * We wait for oplock breaks to be processed before we attempt to perform
585 * writes.
586 */
cifs_get_writer(struct cifsInodeInfo * cinode)587 int cifs_get_writer(struct cifsInodeInfo *cinode)
588 {
589 int rc;
590
591 start:
592 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
593 TASK_KILLABLE);
594 if (rc)
595 return rc;
596
597 spin_lock(&cinode->writers_lock);
598 if (!cinode->writers)
599 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
600 cinode->writers++;
601 /* Check to see if we have started servicing an oplock break */
602 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
603 cinode->writers--;
604 if (cinode->writers == 0) {
605 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
606 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
607 }
608 spin_unlock(&cinode->writers_lock);
609 goto start;
610 }
611 spin_unlock(&cinode->writers_lock);
612 return 0;
613 }
614
cifs_put_writer(struct cifsInodeInfo * cinode)615 void cifs_put_writer(struct cifsInodeInfo *cinode)
616 {
617 spin_lock(&cinode->writers_lock);
618 cinode->writers--;
619 if (cinode->writers == 0) {
620 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
621 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
622 }
623 spin_unlock(&cinode->writers_lock);
624 }
625
626 /**
627 * cifs_queue_oplock_break - queue the oplock break handler for cfile
628 * @cfile: The file to break the oplock on
629 *
630 * This function is called from the demultiplex thread when it
631 * receives an oplock break for @cfile.
632 *
633 * Assumes the tcon->open_file_lock is held.
634 * Assumes cfile->file_info_lock is NOT held.
635 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)636 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
637 {
638 /*
639 * Bump the handle refcount now while we hold the
640 * open_file_lock to enforce the validity of it for the oplock
641 * break handler. The matching put is done at the end of the
642 * handler.
643 */
644 cifsFileInfo_get(cfile);
645
646 queue_work(cifsoplockd_wq, &cfile->oplock_break);
647 }
648
cifs_done_oplock_break(struct cifsInodeInfo * cinode)649 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
650 {
651 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
652 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
653 }
654
655 bool
backup_cred(struct cifs_sb_info * cifs_sb)656 backup_cred(struct cifs_sb_info *cifs_sb)
657 {
658 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
659 if (uid_eq(cifs_sb->ctx->backupuid, current_fsuid()))
660 return true;
661 }
662 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
663 if (in_group_p(cifs_sb->ctx->backupgid))
664 return true;
665 }
666
667 return false;
668 }
669
670 void
cifs_del_pending_open(struct cifs_pending_open * open)671 cifs_del_pending_open(struct cifs_pending_open *open)
672 {
673 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
674 list_del(&open->olist);
675 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
676 }
677
678 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)679 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
680 struct cifs_pending_open *open)
681 {
682 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
683 open->oplock = CIFS_OPLOCK_NO_CHANGE;
684 open->tlink = tlink;
685 fid->pending_open = open;
686 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
687 }
688
689 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)690 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
691 struct cifs_pending_open *open)
692 {
693 spin_lock(&tlink_tcon(tlink)->open_file_lock);
694 cifs_add_pending_open_locked(fid, tlink, open);
695 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
696 }
697
698 /*
699 * Critical section which runs after acquiring deferred_lock.
700 * As there is no reference count on cifs_deferred_close, pdclose
701 * should not be used outside deferred_lock.
702 */
703 bool
cifs_is_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close ** pdclose)704 cifs_is_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close **pdclose)
705 {
706 struct cifs_deferred_close *dclose;
707
708 list_for_each_entry(dclose, &CIFS_I(d_inode(cfile->dentry))->deferred_closes, dlist) {
709 if ((dclose->netfid == cfile->fid.netfid) &&
710 (dclose->persistent_fid == cfile->fid.persistent_fid) &&
711 (dclose->volatile_fid == cfile->fid.volatile_fid)) {
712 *pdclose = dclose;
713 return true;
714 }
715 }
716 return false;
717 }
718
719 /*
720 * Critical section which runs after acquiring deferred_lock.
721 */
722 void
cifs_add_deferred_close(struct cifsFileInfo * cfile,struct cifs_deferred_close * dclose)723 cifs_add_deferred_close(struct cifsFileInfo *cfile, struct cifs_deferred_close *dclose)
724 {
725 bool is_deferred = false;
726 struct cifs_deferred_close *pdclose;
727
728 is_deferred = cifs_is_deferred_close(cfile, &pdclose);
729 if (is_deferred) {
730 kfree(dclose);
731 return;
732 }
733
734 dclose->tlink = cfile->tlink;
735 dclose->netfid = cfile->fid.netfid;
736 dclose->persistent_fid = cfile->fid.persistent_fid;
737 dclose->volatile_fid = cfile->fid.volatile_fid;
738 list_add_tail(&dclose->dlist, &CIFS_I(d_inode(cfile->dentry))->deferred_closes);
739 }
740
741 /*
742 * Critical section which runs after acquiring deferred_lock.
743 */
744 void
cifs_del_deferred_close(struct cifsFileInfo * cfile)745 cifs_del_deferred_close(struct cifsFileInfo *cfile)
746 {
747 bool is_deferred = false;
748 struct cifs_deferred_close *dclose;
749
750 is_deferred = cifs_is_deferred_close(cfile, &dclose);
751 if (!is_deferred)
752 return;
753 list_del(&dclose->dlist);
754 kfree(dclose);
755 }
756
757 void
cifs_close_deferred_file(struct cifsInodeInfo * cifs_inode)758 cifs_close_deferred_file(struct cifsInodeInfo *cifs_inode)
759 {
760 struct cifsFileInfo *cfile = NULL;
761 struct file_list *tmp_list, *tmp_next_list;
762 struct list_head file_head;
763
764 if (cifs_inode == NULL)
765 return;
766
767 INIT_LIST_HEAD(&file_head);
768 spin_lock(&cifs_inode->open_file_lock);
769 list_for_each_entry(cfile, &cifs_inode->openFileList, flist) {
770 if (delayed_work_pending(&cfile->deferred)) {
771 if (cancel_delayed_work(&cfile->deferred)) {
772 spin_lock(&cifs_inode->deferred_lock);
773 cifs_del_deferred_close(cfile);
774 spin_unlock(&cifs_inode->deferred_lock);
775
776 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
777 if (tmp_list == NULL)
778 break;
779 tmp_list->cfile = cfile;
780 list_add_tail(&tmp_list->list, &file_head);
781 }
782 }
783 }
784 spin_unlock(&cifs_inode->open_file_lock);
785
786 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
787 _cifsFileInfo_put(tmp_list->cfile, false, false);
788 list_del(&tmp_list->list);
789 kfree(tmp_list);
790 }
791 }
792
793 void
cifs_close_all_deferred_files(struct cifs_tcon * tcon)794 cifs_close_all_deferred_files(struct cifs_tcon *tcon)
795 {
796 struct cifsFileInfo *cfile;
797 struct file_list *tmp_list, *tmp_next_list;
798 struct list_head file_head;
799
800 INIT_LIST_HEAD(&file_head);
801 spin_lock(&tcon->open_file_lock);
802 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
803 if (delayed_work_pending(&cfile->deferred)) {
804 if (cancel_delayed_work(&cfile->deferred)) {
805 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
806 cifs_del_deferred_close(cfile);
807 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
808
809 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
810 if (tmp_list == NULL)
811 break;
812 tmp_list->cfile = cfile;
813 list_add_tail(&tmp_list->list, &file_head);
814 }
815 }
816 }
817 spin_unlock(&tcon->open_file_lock);
818
819 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
820 _cifsFileInfo_put(tmp_list->cfile, true, false);
821 list_del(&tmp_list->list);
822 kfree(tmp_list);
823 }
824 }
825 void
cifs_close_deferred_file_under_dentry(struct cifs_tcon * tcon,const char * path)826 cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
827 {
828 struct cifsFileInfo *cfile;
829 struct file_list *tmp_list, *tmp_next_list;
830 struct list_head file_head;
831 void *page;
832 const char *full_path;
833
834 INIT_LIST_HEAD(&file_head);
835 page = alloc_dentry_path();
836 spin_lock(&tcon->open_file_lock);
837 list_for_each_entry(cfile, &tcon->openFileList, tlist) {
838 full_path = build_path_from_dentry(cfile->dentry, page);
839 if (strstr(full_path, path)) {
840 if (delayed_work_pending(&cfile->deferred)) {
841 if (cancel_delayed_work(&cfile->deferred)) {
842 spin_lock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
843 cifs_del_deferred_close(cfile);
844 spin_unlock(&CIFS_I(d_inode(cfile->dentry))->deferred_lock);
845
846 tmp_list = kmalloc(sizeof(struct file_list), GFP_ATOMIC);
847 if (tmp_list == NULL)
848 break;
849 tmp_list->cfile = cfile;
850 list_add_tail(&tmp_list->list, &file_head);
851 }
852 }
853 }
854 }
855 spin_unlock(&tcon->open_file_lock);
856
857 list_for_each_entry_safe(tmp_list, tmp_next_list, &file_head, list) {
858 _cifsFileInfo_put(tmp_list->cfile, true, false);
859 list_del(&tmp_list->list);
860 kfree(tmp_list);
861 }
862 free_dentry_path(page);
863 }
864
865 /*
866 * If a dentry has been deleted, all corresponding open handles should know that
867 * so that we do not defer close them.
868 */
cifs_mark_open_handles_for_deleted_file(struct inode * inode,const char * path)869 void cifs_mark_open_handles_for_deleted_file(struct inode *inode,
870 const char *path)
871 {
872 struct cifsFileInfo *cfile;
873 void *page;
874 const char *full_path;
875 struct cifsInodeInfo *cinode = CIFS_I(inode);
876
877 page = alloc_dentry_path();
878 spin_lock(&cinode->open_file_lock);
879
880 /*
881 * note: we need to construct path from dentry and compare only if the
882 * inode has any hardlinks. When number of hardlinks is 1, we can just
883 * mark all open handles since they are going to be from the same file.
884 */
885 if (inode->i_nlink > 1) {
886 list_for_each_entry(cfile, &cinode->openFileList, flist) {
887 full_path = build_path_from_dentry(cfile->dentry, page);
888 if (!IS_ERR(full_path) && strcmp(full_path, path) == 0)
889 cfile->status_file_deleted = true;
890 }
891 } else {
892 list_for_each_entry(cfile, &cinode->openFileList, flist)
893 cfile->status_file_deleted = true;
894 }
895 spin_unlock(&cinode->open_file_lock);
896 free_dentry_path(page);
897 }
898
899 /* parses DFS referral V3 structure
900 * caller is responsible for freeing target_nodes
901 * returns:
902 * - on success - 0
903 * - on failure - errno
904 */
905 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)906 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
907 unsigned int *num_of_nodes,
908 struct dfs_info3_param **target_nodes,
909 const struct nls_table *nls_codepage, int remap,
910 const char *searchName, bool is_unicode)
911 {
912 int i, rc = 0;
913 char *data_end;
914 struct dfs_referral_level_3 *ref;
915
916 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
917
918 if (*num_of_nodes < 1) {
919 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
920 *num_of_nodes);
921 rc = -EINVAL;
922 goto parse_DFS_referrals_exit;
923 }
924
925 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
926 if (ref->VersionNumber != cpu_to_le16(3)) {
927 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
928 le16_to_cpu(ref->VersionNumber));
929 rc = -EINVAL;
930 goto parse_DFS_referrals_exit;
931 }
932
933 /* get the upper boundary of the resp buffer */
934 data_end = (char *)rsp + rsp_size;
935
936 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
937 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
938
939 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
940 GFP_KERNEL);
941 if (*target_nodes == NULL) {
942 rc = -ENOMEM;
943 goto parse_DFS_referrals_exit;
944 }
945
946 /* collect necessary data from referrals */
947 for (i = 0; i < *num_of_nodes; i++) {
948 char *temp;
949 int max_len;
950 struct dfs_info3_param *node = (*target_nodes)+i;
951
952 node->flags = le32_to_cpu(rsp->DFSFlags);
953 if (is_unicode) {
954 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
955 GFP_KERNEL);
956 if (tmp == NULL) {
957 rc = -ENOMEM;
958 goto parse_DFS_referrals_exit;
959 }
960 cifsConvertToUTF16((__le16 *) tmp, searchName,
961 PATH_MAX, nls_codepage, remap);
962 node->path_consumed = cifs_utf16_bytes(tmp,
963 le16_to_cpu(rsp->PathConsumed),
964 nls_codepage);
965 kfree(tmp);
966 } else
967 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
968
969 node->server_type = le16_to_cpu(ref->ServerType);
970 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
971
972 /* copy DfsPath */
973 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
974 max_len = data_end - temp;
975 node->path_name = cifs_strndup_from_utf16(temp, max_len,
976 is_unicode, nls_codepage);
977 if (!node->path_name) {
978 rc = -ENOMEM;
979 goto parse_DFS_referrals_exit;
980 }
981
982 /* copy link target UNC */
983 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
984 max_len = data_end - temp;
985 node->node_name = cifs_strndup_from_utf16(temp, max_len,
986 is_unicode, nls_codepage);
987 if (!node->node_name) {
988 rc = -ENOMEM;
989 goto parse_DFS_referrals_exit;
990 }
991
992 node->ttl = le32_to_cpu(ref->TimeToLive);
993
994 ref++;
995 }
996
997 parse_DFS_referrals_exit:
998 if (rc) {
999 free_dfs_info_array(*target_nodes, *num_of_nodes);
1000 *target_nodes = NULL;
1001 *num_of_nodes = 0;
1002 }
1003 return rc;
1004 }
1005
1006 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)1007 cifs_aio_ctx_alloc(void)
1008 {
1009 struct cifs_aio_ctx *ctx;
1010
1011 /*
1012 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
1013 * to false so that we know when we have to unreference pages within
1014 * cifs_aio_ctx_release()
1015 */
1016 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
1017 if (!ctx)
1018 return NULL;
1019
1020 INIT_LIST_HEAD(&ctx->list);
1021 mutex_init(&ctx->aio_mutex);
1022 init_completion(&ctx->done);
1023 kref_init(&ctx->refcount);
1024 return ctx;
1025 }
1026
1027 void
cifs_aio_ctx_release(struct kref * refcount)1028 cifs_aio_ctx_release(struct kref *refcount)
1029 {
1030 struct cifs_aio_ctx *ctx = container_of(refcount,
1031 struct cifs_aio_ctx, refcount);
1032
1033 cifsFileInfo_put(ctx->cfile);
1034
1035 /*
1036 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
1037 * which means that iov_iter_extract_pages() was a success and thus
1038 * that we may have references or pins on pages that we need to
1039 * release.
1040 */
1041 if (ctx->bv) {
1042 if (ctx->should_dirty || ctx->bv_need_unpin) {
1043 unsigned int i;
1044
1045 for (i = 0; i < ctx->nr_pinned_pages; i++) {
1046 struct page *page = ctx->bv[i].bv_page;
1047
1048 if (ctx->should_dirty)
1049 set_page_dirty(page);
1050 if (ctx->bv_need_unpin)
1051 unpin_user_page(page);
1052 }
1053 }
1054 kvfree(ctx->bv);
1055 }
1056
1057 kfree(ctx);
1058 }
1059
1060 /**
1061 * cifs_alloc_hash - allocate hash and hash context together
1062 * @name: The name of the crypto hash algo
1063 * @sdesc: SHASH descriptor where to put the pointer to the hash TFM
1064 *
1065 * The caller has to make sure @sdesc is initialized to either NULL or
1066 * a valid context. It can be freed via cifs_free_hash().
1067 */
1068 int
cifs_alloc_hash(const char * name,struct shash_desc ** sdesc)1069 cifs_alloc_hash(const char *name, struct shash_desc **sdesc)
1070 {
1071 int rc = 0;
1072 struct crypto_shash *alg = NULL;
1073
1074 if (*sdesc)
1075 return 0;
1076
1077 alg = crypto_alloc_shash(name, 0, 0);
1078 if (IS_ERR(alg)) {
1079 cifs_dbg(VFS, "Could not allocate shash TFM '%s'\n", name);
1080 rc = PTR_ERR(alg);
1081 *sdesc = NULL;
1082 return rc;
1083 }
1084
1085 *sdesc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(alg), GFP_KERNEL);
1086 if (*sdesc == NULL) {
1087 cifs_dbg(VFS, "no memory left to allocate shash TFM '%s'\n", name);
1088 crypto_free_shash(alg);
1089 return -ENOMEM;
1090 }
1091
1092 (*sdesc)->tfm = alg;
1093 return 0;
1094 }
1095
1096 /**
1097 * cifs_free_hash - free hash and hash context together
1098 * @sdesc: Where to find the pointer to the hash TFM
1099 *
1100 * Freeing a NULL descriptor is safe.
1101 */
1102 void
cifs_free_hash(struct shash_desc ** sdesc)1103 cifs_free_hash(struct shash_desc **sdesc)
1104 {
1105 if (unlikely(!sdesc) || !*sdesc)
1106 return;
1107
1108 if ((*sdesc)->tfm) {
1109 crypto_free_shash((*sdesc)->tfm);
1110 (*sdesc)->tfm = NULL;
1111 }
1112
1113 kfree_sensitive(*sdesc);
1114 *sdesc = NULL;
1115 }
1116
extract_unc_hostname(const char * unc,const char ** h,size_t * len)1117 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
1118 {
1119 const char *end;
1120
1121 /* skip initial slashes */
1122 while (*unc && (*unc == '\\' || *unc == '/'))
1123 unc++;
1124
1125 end = unc;
1126
1127 while (*end && !(*end == '\\' || *end == '/'))
1128 end++;
1129
1130 *h = unc;
1131 *len = end - unc;
1132 }
1133
1134 /**
1135 * copy_path_name - copy src path to dst, possibly truncating
1136 * @dst: The destination buffer
1137 * @src: The source name
1138 *
1139 * returns number of bytes written (including trailing nul)
1140 */
copy_path_name(char * dst,const char * src)1141 int copy_path_name(char *dst, const char *src)
1142 {
1143 int name_len;
1144
1145 /*
1146 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1147 * will truncate and strlen(dst) will be PATH_MAX-1
1148 */
1149 name_len = strscpy(dst, src, PATH_MAX);
1150 if (WARN_ON_ONCE(name_len < 0))
1151 name_len = PATH_MAX-1;
1152
1153 /* we count the trailing nul */
1154 name_len++;
1155 return name_len;
1156 }
1157
1158 struct super_cb_data {
1159 void *data;
1160 struct super_block *sb;
1161 };
1162
tcon_super_cb(struct super_block * sb,void * arg)1163 static void tcon_super_cb(struct super_block *sb, void *arg)
1164 {
1165 struct super_cb_data *sd = arg;
1166 struct cifs_sb_info *cifs_sb;
1167 struct cifs_tcon *t1 = sd->data, *t2;
1168
1169 if (sd->sb)
1170 return;
1171
1172 cifs_sb = CIFS_SB(sb);
1173 t2 = cifs_sb_master_tcon(cifs_sb);
1174
1175 spin_lock(&t2->tc_lock);
1176 if (t1->ses == t2->ses &&
1177 t1->ses->server == t2->ses->server &&
1178 t2->origin_fullpath &&
1179 dfs_src_pathname_equal(t2->origin_fullpath, t1->origin_fullpath))
1180 sd->sb = sb;
1181 spin_unlock(&t2->tc_lock);
1182 }
1183
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)1184 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1185 void *data)
1186 {
1187 struct super_cb_data sd = {
1188 .data = data,
1189 .sb = NULL,
1190 };
1191 struct file_system_type **fs_type = (struct file_system_type *[]) {
1192 &cifs_fs_type, &smb3_fs_type, NULL,
1193 };
1194
1195 for (; *fs_type; fs_type++) {
1196 iterate_supers_type(*fs_type, f, &sd);
1197 if (sd.sb) {
1198 /*
1199 * Grab an active reference in order to prevent automounts (DFS links)
1200 * of expiring and then freeing up our cifs superblock pointer while
1201 * we're doing failover.
1202 */
1203 cifs_sb_active(sd.sb);
1204 return sd.sb;
1205 }
1206 }
1207 pr_warn_once("%s: could not find dfs superblock\n", __func__);
1208 return ERR_PTR(-EINVAL);
1209 }
1210
__cifs_put_super(struct super_block * sb)1211 static void __cifs_put_super(struct super_block *sb)
1212 {
1213 if (!IS_ERR_OR_NULL(sb))
1214 cifs_sb_deactive(sb);
1215 }
1216
cifs_get_dfs_tcon_super(struct cifs_tcon * tcon)1217 struct super_block *cifs_get_dfs_tcon_super(struct cifs_tcon *tcon)
1218 {
1219 spin_lock(&tcon->tc_lock);
1220 if (!tcon->origin_fullpath) {
1221 spin_unlock(&tcon->tc_lock);
1222 return ERR_PTR(-ENOENT);
1223 }
1224 spin_unlock(&tcon->tc_lock);
1225 return __cifs_get_super(tcon_super_cb, tcon);
1226 }
1227
cifs_put_tcp_super(struct super_block * sb)1228 void cifs_put_tcp_super(struct super_block *sb)
1229 {
1230 __cifs_put_super(sb);
1231 }
1232
1233 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * share,size_t share_len,bool * result)1234 int match_target_ip(struct TCP_Server_Info *server,
1235 const char *share, size_t share_len,
1236 bool *result)
1237 {
1238 int rc;
1239 char *target;
1240 struct sockaddr_storage ss;
1241
1242 *result = false;
1243
1244 target = kzalloc(share_len + 3, GFP_KERNEL);
1245 if (!target)
1246 return -ENOMEM;
1247
1248 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1249
1250 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1251
1252 rc = dns_resolve_server_name_to_ip(target, (struct sockaddr *)&ss, NULL);
1253 kfree(target);
1254
1255 if (rc < 0)
1256 return rc;
1257
1258 spin_lock(&server->srv_lock);
1259 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr, (struct sockaddr *)&ss);
1260 spin_unlock(&server->srv_lock);
1261 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1262 return 0;
1263 }
1264
cifs_update_super_prepath(struct cifs_sb_info * cifs_sb,char * prefix)1265 int cifs_update_super_prepath(struct cifs_sb_info *cifs_sb, char *prefix)
1266 {
1267 int rc;
1268
1269 kfree(cifs_sb->prepath);
1270 cifs_sb->prepath = NULL;
1271
1272 if (prefix && *prefix) {
1273 cifs_sb->prepath = cifs_sanitize_prepath(prefix, GFP_ATOMIC);
1274 if (IS_ERR(cifs_sb->prepath)) {
1275 rc = PTR_ERR(cifs_sb->prepath);
1276 cifs_sb->prepath = NULL;
1277 return rc;
1278 }
1279 if (cifs_sb->prepath)
1280 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1281 }
1282
1283 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1284 return 0;
1285 }
1286
1287 /*
1288 * Handle weird Windows SMB server behaviour. It responds with
1289 * STATUS_OBJECT_NAME_INVALID code to SMB2 QUERY_INFO request for
1290 * "\<server>\<dfsname>\<linkpath>" DFS reference, where <dfsname> contains
1291 * non-ASCII unicode symbols.
1292 */
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)1293 int cifs_inval_name_dfs_link_error(const unsigned int xid,
1294 struct cifs_tcon *tcon,
1295 struct cifs_sb_info *cifs_sb,
1296 const char *full_path,
1297 bool *islink)
1298 {
1299 struct TCP_Server_Info *server = tcon->ses->server;
1300 struct cifs_ses *ses = tcon->ses;
1301 size_t len;
1302 char *path;
1303 char *ref_path;
1304
1305 *islink = false;
1306
1307 /*
1308 * Fast path - skip check when @full_path doesn't have a prefix path to
1309 * look up or tcon is not DFS.
1310 */
1311 if (strlen(full_path) < 2 || !cifs_sb ||
1312 (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
1313 !is_tcon_dfs(tcon))
1314 return 0;
1315
1316 spin_lock(&server->srv_lock);
1317 if (!server->leaf_fullpath) {
1318 spin_unlock(&server->srv_lock);
1319 return 0;
1320 }
1321 spin_unlock(&server->srv_lock);
1322
1323 /*
1324 * Slow path - tcon is DFS and @full_path has prefix path, so attempt
1325 * to get a referral to figure out whether it is an DFS link.
1326 */
1327 len = strnlen(tcon->tree_name, MAX_TREE_SIZE + 1) + strlen(full_path) + 1;
1328 path = kmalloc(len, GFP_KERNEL);
1329 if (!path)
1330 return -ENOMEM;
1331
1332 scnprintf(path, len, "%s%s", tcon->tree_name, full_path);
1333 ref_path = dfs_cache_canonical_path(path + 1, cifs_sb->local_nls,
1334 cifs_remap(cifs_sb));
1335 kfree(path);
1336
1337 if (IS_ERR(ref_path)) {
1338 if (PTR_ERR(ref_path) != -EINVAL)
1339 return PTR_ERR(ref_path);
1340 } else {
1341 struct dfs_info3_param *refs = NULL;
1342 int num_refs = 0;
1343
1344 /*
1345 * XXX: we are not using dfs_cache_find() here because we might
1346 * end up filling all the DFS cache and thus potentially
1347 * removing cached DFS targets that the client would eventually
1348 * need during failover.
1349 */
1350 ses = CIFS_DFS_ROOT_SES(ses);
1351 if (ses->server->ops->get_dfs_refer &&
1352 !ses->server->ops->get_dfs_refer(xid, ses, ref_path, &refs,
1353 &num_refs, cifs_sb->local_nls,
1354 cifs_remap(cifs_sb)))
1355 *islink = refs[0].server_type == DFS_TYPE_LINK;
1356 free_dfs_info_array(refs, num_refs);
1357 kfree(ref_path);
1358 }
1359 return 0;
1360 }
1361 #endif
1362
cifs_wait_for_server_reconnect(struct TCP_Server_Info * server,bool retry)1363 int cifs_wait_for_server_reconnect(struct TCP_Server_Info *server, bool retry)
1364 {
1365 int timeout = 10;
1366 int rc;
1367
1368 spin_lock(&server->srv_lock);
1369 if (server->tcpStatus != CifsNeedReconnect) {
1370 spin_unlock(&server->srv_lock);
1371 return 0;
1372 }
1373 timeout *= server->nr_targets;
1374 spin_unlock(&server->srv_lock);
1375
1376 /*
1377 * Give demultiplex thread up to 10 seconds to each target available for
1378 * reconnect -- should be greater than cifs socket timeout which is 7
1379 * seconds.
1380 *
1381 * On "soft" mounts we wait once. Hard mounts keep retrying until
1382 * process is killed or server comes back on-line.
1383 */
1384 do {
1385 rc = wait_event_interruptible_timeout(server->response_q,
1386 (server->tcpStatus != CifsNeedReconnect),
1387 timeout * HZ);
1388 if (rc < 0) {
1389 cifs_dbg(FYI, "%s: aborting reconnect due to received signal\n",
1390 __func__);
1391 return -ERESTARTSYS;
1392 }
1393
1394 /* are we still trying to reconnect? */
1395 spin_lock(&server->srv_lock);
1396 if (server->tcpStatus != CifsNeedReconnect) {
1397 spin_unlock(&server->srv_lock);
1398 return 0;
1399 }
1400 spin_unlock(&server->srv_lock);
1401 } while (retry);
1402
1403 cifs_dbg(FYI, "%s: gave up waiting on reconnect\n", __func__);
1404 return -EHOSTDOWN;
1405 }
1406