1 /*
2 * fs/cifs/misc.c
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
6 *
7 * This library is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU Lesser General Public License as published
9 * by the Free Software Foundation; either version 2.1 of the License, or
10 * (at your option) any later version.
11 *
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
15 * the GNU Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #include <linux/slab.h>
23 #include <linux/ctype.h>
24 #include <linux/mempool.h>
25 #include <linux/vmalloc.h>
26 #include "cifspdu.h"
27 #include "cifsglob.h"
28 #include "cifsproto.h"
29 #include "cifs_debug.h"
30 #include "smberr.h"
31 #include "nterr.h"
32 #include "cifs_unicode.h"
33 #include "smb2pdu.h"
34 #include "cifsfs.h"
35 #ifdef CONFIG_CIFS_DFS_UPCALL
36 #include "dns_resolve.h"
37 #endif
38
39 extern mempool_t *cifs_sm_req_poolp;
40 extern mempool_t *cifs_req_poolp;
41
42 /* The xid serves as a useful identifier for each incoming vfs request,
43 in a similar way to the mid which is useful to track each sent smb,
44 and CurrentXid can also provide a running counter (although it
45 will eventually wrap past zero) of the total vfs operations handled
46 since the cifs fs was mounted */
47
48 unsigned int
_get_xid(void)49 _get_xid(void)
50 {
51 unsigned int xid;
52
53 spin_lock(&GlobalMid_Lock);
54 GlobalTotalActiveXid++;
55
56 /* keep high water mark for number of simultaneous ops in filesystem */
57 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
58 GlobalMaxActiveXid = GlobalTotalActiveXid;
59 if (GlobalTotalActiveXid > 65000)
60 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
61 xid = GlobalCurrentXid++;
62 spin_unlock(&GlobalMid_Lock);
63 return xid;
64 }
65
66 void
_free_xid(unsigned int xid)67 _free_xid(unsigned int xid)
68 {
69 spin_lock(&GlobalMid_Lock);
70 /* if (GlobalTotalActiveXid == 0)
71 BUG(); */
72 GlobalTotalActiveXid--;
73 spin_unlock(&GlobalMid_Lock);
74 }
75
76 struct cifs_ses *
sesInfoAlloc(void)77 sesInfoAlloc(void)
78 {
79 struct cifs_ses *ret_buf;
80
81 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
82 if (ret_buf) {
83 atomic_inc(&sesInfoAllocCount);
84 ret_buf->status = CifsNew;
85 ++ret_buf->ses_count;
86 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
87 INIT_LIST_HEAD(&ret_buf->tcon_list);
88 mutex_init(&ret_buf->session_mutex);
89 spin_lock_init(&ret_buf->iface_lock);
90 }
91 return ret_buf;
92 }
93
94 void
sesInfoFree(struct cifs_ses * buf_to_free)95 sesInfoFree(struct cifs_ses *buf_to_free)
96 {
97 if (buf_to_free == NULL) {
98 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
99 return;
100 }
101
102 atomic_dec(&sesInfoAllocCount);
103 kfree(buf_to_free->serverOS);
104 kfree(buf_to_free->serverDomain);
105 kfree(buf_to_free->serverNOS);
106 kfree_sensitive(buf_to_free->password);
107 kfree(buf_to_free->user_name);
108 kfree(buf_to_free->domainName);
109 kfree_sensitive(buf_to_free->auth_key.response);
110 kfree(buf_to_free->iface_list);
111 kfree_sensitive(buf_to_free);
112 }
113
114 struct cifs_tcon *
tconInfoAlloc(void)115 tconInfoAlloc(void)
116 {
117 struct cifs_tcon *ret_buf;
118
119 ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
120 if (!ret_buf)
121 return NULL;
122 ret_buf->crfid.fid = kzalloc(sizeof(*ret_buf->crfid.fid), GFP_KERNEL);
123 if (!ret_buf->crfid.fid) {
124 kfree(ret_buf);
125 return NULL;
126 }
127
128 atomic_inc(&tconInfoAllocCount);
129 ret_buf->tidStatus = CifsNew;
130 ++ret_buf->tc_count;
131 INIT_LIST_HEAD(&ret_buf->openFileList);
132 INIT_LIST_HEAD(&ret_buf->tcon_list);
133 spin_lock_init(&ret_buf->open_file_lock);
134 mutex_init(&ret_buf->crfid.fid_mutex);
135 spin_lock_init(&ret_buf->stat_lock);
136 atomic_set(&ret_buf->num_local_opens, 0);
137 atomic_set(&ret_buf->num_remote_opens, 0);
138
139 return ret_buf;
140 }
141
142 void
tconInfoFree(struct cifs_tcon * buf_to_free)143 tconInfoFree(struct cifs_tcon *buf_to_free)
144 {
145 if (buf_to_free == NULL) {
146 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
147 return;
148 }
149 atomic_dec(&tconInfoAllocCount);
150 kfree(buf_to_free->nativeFileSystem);
151 kfree_sensitive(buf_to_free->password);
152 kfree(buf_to_free->crfid.fid);
153 #ifdef CONFIG_CIFS_DFS_UPCALL
154 kfree(buf_to_free->dfs_path);
155 #endif
156 kfree(buf_to_free);
157 }
158
159 struct smb_hdr *
cifs_buf_get(void)160 cifs_buf_get(void)
161 {
162 struct smb_hdr *ret_buf = NULL;
163 /*
164 * SMB2 header is bigger than CIFS one - no problems to clean some
165 * more bytes for CIFS.
166 */
167 size_t buf_size = sizeof(struct smb2_sync_hdr);
168
169 /*
170 * We could use negotiated size instead of max_msgsize -
171 * but it may be more efficient to always alloc same size
172 * albeit slightly larger than necessary and maxbuffersize
173 * defaults to this and can not be bigger.
174 */
175 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
176
177 /* clear the first few header bytes */
178 /* for most paths, more is cleared in header_assemble */
179 memset(ret_buf, 0, buf_size + 3);
180 atomic_inc(&bufAllocCount);
181 #ifdef CONFIG_CIFS_STATS2
182 atomic_inc(&totBufAllocCount);
183 #endif /* CONFIG_CIFS_STATS2 */
184
185 return ret_buf;
186 }
187
188 void
cifs_buf_release(void * buf_to_free)189 cifs_buf_release(void *buf_to_free)
190 {
191 if (buf_to_free == NULL) {
192 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
193 return;
194 }
195 mempool_free(buf_to_free, cifs_req_poolp);
196
197 atomic_dec(&bufAllocCount);
198 return;
199 }
200
201 struct smb_hdr *
cifs_small_buf_get(void)202 cifs_small_buf_get(void)
203 {
204 struct smb_hdr *ret_buf = NULL;
205
206 /* We could use negotiated size instead of max_msgsize -
207 but it may be more efficient to always alloc same size
208 albeit slightly larger than necessary and maxbuffersize
209 defaults to this and can not be bigger */
210 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
211 /* No need to clear memory here, cleared in header assemble */
212 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
213 atomic_inc(&smBufAllocCount);
214 #ifdef CONFIG_CIFS_STATS2
215 atomic_inc(&totSmBufAllocCount);
216 #endif /* CONFIG_CIFS_STATS2 */
217
218 return ret_buf;
219 }
220
221 void
cifs_small_buf_release(void * buf_to_free)222 cifs_small_buf_release(void *buf_to_free)
223 {
224
225 if (buf_to_free == NULL) {
226 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
227 return;
228 }
229 mempool_free(buf_to_free, cifs_sm_req_poolp);
230
231 atomic_dec(&smBufAllocCount);
232 return;
233 }
234
235 void
free_rsp_buf(int resp_buftype,void * rsp)236 free_rsp_buf(int resp_buftype, void *rsp)
237 {
238 if (resp_buftype == CIFS_SMALL_BUFFER)
239 cifs_small_buf_release(rsp);
240 else if (resp_buftype == CIFS_LARGE_BUFFER)
241 cifs_buf_release(rsp);
242 }
243
244 /* NB: MID can not be set if treeCon not passed in, in that
245 case it is responsbility of caller to set the mid */
246 void
header_assemble(struct smb_hdr * buffer,char smb_command,const struct cifs_tcon * treeCon,int word_count)247 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
248 const struct cifs_tcon *treeCon, int word_count
249 /* length of fixed section (word count) in two byte units */)
250 {
251 char *temp = (char *) buffer;
252
253 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
254
255 buffer->smb_buf_length = cpu_to_be32(
256 (2 * word_count) + sizeof(struct smb_hdr) -
257 4 /* RFC 1001 length field does not count */ +
258 2 /* for bcc field itself */) ;
259
260 buffer->Protocol[0] = 0xFF;
261 buffer->Protocol[1] = 'S';
262 buffer->Protocol[2] = 'M';
263 buffer->Protocol[3] = 'B';
264 buffer->Command = smb_command;
265 buffer->Flags = 0x00; /* case sensitive */
266 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
267 buffer->Pid = cpu_to_le16((__u16)current->tgid);
268 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
269 if (treeCon) {
270 buffer->Tid = treeCon->tid;
271 if (treeCon->ses) {
272 if (treeCon->ses->capabilities & CAP_UNICODE)
273 buffer->Flags2 |= SMBFLG2_UNICODE;
274 if (treeCon->ses->capabilities & CAP_STATUS32)
275 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
276
277 /* Uid is not converted */
278 buffer->Uid = treeCon->ses->Suid;
279 buffer->Mid = get_next_mid(treeCon->ses->server);
280 }
281 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
282 buffer->Flags2 |= SMBFLG2_DFS;
283 if (treeCon->nocase)
284 buffer->Flags |= SMBFLG_CASELESS;
285 if ((treeCon->ses) && (treeCon->ses->server))
286 if (treeCon->ses->server->sign)
287 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
288 }
289
290 /* endian conversion of flags is now done just before sending */
291 buffer->WordCount = (char) word_count;
292 return;
293 }
294
295 static int
check_smb_hdr(struct smb_hdr * smb)296 check_smb_hdr(struct smb_hdr *smb)
297 {
298 /* does it have the right SMB "signature" ? */
299 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
300 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
301 *(unsigned int *)smb->Protocol);
302 return 1;
303 }
304
305 /* if it's a response then accept */
306 if (smb->Flags & SMBFLG_RESPONSE)
307 return 0;
308
309 /* only one valid case where server sends us request */
310 if (smb->Command == SMB_COM_LOCKING_ANDX)
311 return 0;
312
313 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
314 get_mid(smb));
315 return 1;
316 }
317
318 int
checkSMB(char * buf,unsigned int total_read,struct TCP_Server_Info * server)319 checkSMB(char *buf, unsigned int total_read, struct TCP_Server_Info *server)
320 {
321 struct smb_hdr *smb = (struct smb_hdr *)buf;
322 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
323 __u32 clc_len; /* calculated length */
324 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
325 total_read, rfclen);
326
327 /* is this frame too small to even get to a BCC? */
328 if (total_read < 2 + sizeof(struct smb_hdr)) {
329 if ((total_read >= sizeof(struct smb_hdr) - 1)
330 && (smb->Status.CifsError != 0)) {
331 /* it's an error return */
332 smb->WordCount = 0;
333 /* some error cases do not return wct and bcc */
334 return 0;
335 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
336 (smb->WordCount == 0)) {
337 char *tmp = (char *)smb;
338 /* Need to work around a bug in two servers here */
339 /* First, check if the part of bcc they sent was zero */
340 if (tmp[sizeof(struct smb_hdr)] == 0) {
341 /* some servers return only half of bcc
342 * on simple responses (wct, bcc both zero)
343 * in particular have seen this on
344 * ulogoffX and FindClose. This leaves
345 * one byte of bcc potentially unitialized
346 */
347 /* zero rest of bcc */
348 tmp[sizeof(struct smb_hdr)+1] = 0;
349 return 0;
350 }
351 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
352 } else {
353 cifs_dbg(VFS, "Length less than smb header size\n");
354 }
355 return -EIO;
356 } else if (total_read < sizeof(*smb) + 2 * smb->WordCount) {
357 cifs_dbg(VFS, "%s: can't read BCC due to invalid WordCount(%u)\n",
358 __func__, smb->WordCount);
359 return -EIO;
360 }
361
362 /* otherwise, there is enough to get to the BCC */
363 if (check_smb_hdr(smb))
364 return -EIO;
365 clc_len = smbCalcSize(smb, server);
366
367 if (4 + rfclen != total_read) {
368 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
369 rfclen);
370 return -EIO;
371 }
372
373 if (4 + rfclen != clc_len) {
374 __u16 mid = get_mid(smb);
375 /* check if bcc wrapped around for large read responses */
376 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
377 /* check if lengths match mod 64K */
378 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
379 return 0; /* bcc wrapped */
380 }
381 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
382 clc_len, 4 + rfclen, mid);
383
384 if (4 + rfclen < clc_len) {
385 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
386 rfclen, mid);
387 return -EIO;
388 } else if (rfclen > clc_len + 512) {
389 /*
390 * Some servers (Windows XP in particular) send more
391 * data than the lengths in the SMB packet would
392 * indicate on certain calls (byte range locks and
393 * trans2 find first calls in particular). While the
394 * client can handle such a frame by ignoring the
395 * trailing data, we choose limit the amount of extra
396 * data to 512 bytes.
397 */
398 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
399 rfclen, mid);
400 return -EIO;
401 }
402 }
403 return 0;
404 }
405
406 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)407 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
408 {
409 struct smb_hdr *buf = (struct smb_hdr *)buffer;
410 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
411 struct list_head *tmp, *tmp1, *tmp2;
412 struct cifs_ses *ses;
413 struct cifs_tcon *tcon;
414 struct cifsInodeInfo *pCifsInode;
415 struct cifsFileInfo *netfile;
416
417 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
418 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
419 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
420 struct smb_com_transaction_change_notify_rsp *pSMBr =
421 (struct smb_com_transaction_change_notify_rsp *)buf;
422 struct file_notify_information *pnotify;
423 __u32 data_offset = 0;
424 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
425
426 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
427 data_offset = le32_to_cpu(pSMBr->DataOffset);
428
429 if (data_offset >
430 len - sizeof(struct file_notify_information)) {
431 cifs_dbg(FYI, "Invalid data_offset %u\n",
432 data_offset);
433 return true;
434 }
435 pnotify = (struct file_notify_information *)
436 ((char *)&pSMBr->hdr.Protocol + data_offset);
437 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
438 pnotify->FileName, pnotify->Action);
439 /* cifs_dump_mem("Rcvd notify Data: ",buf,
440 sizeof(struct smb_hdr)+60); */
441 return true;
442 }
443 if (pSMBr->hdr.Status.CifsError) {
444 cifs_dbg(FYI, "notify err 0x%x\n",
445 pSMBr->hdr.Status.CifsError);
446 return true;
447 }
448 return false;
449 }
450 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
451 return false;
452 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
453 /* no sense logging error on invalid handle on oplock
454 break - harmless race between close request and oplock
455 break response is expected from time to time writing out
456 large dirty files cached on the client */
457 if ((NT_STATUS_INVALID_HANDLE) ==
458 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
459 cifs_dbg(FYI, "Invalid handle on oplock break\n");
460 return true;
461 } else if (ERRbadfid ==
462 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
463 return true;
464 } else {
465 return false; /* on valid oplock brk we get "request" */
466 }
467 }
468 if (pSMB->hdr.WordCount != 8)
469 return false;
470
471 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
472 pSMB->LockType, pSMB->OplockLevel);
473 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
474 return false;
475
476 /* look up tcon based on tid & uid */
477 spin_lock(&cifs_tcp_ses_lock);
478 list_for_each(tmp, &srv->smb_ses_list) {
479 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
480 list_for_each(tmp1, &ses->tcon_list) {
481 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
482 if (tcon->tid != buf->Tid)
483 continue;
484
485 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
486 spin_lock(&tcon->open_file_lock);
487 list_for_each(tmp2, &tcon->openFileList) {
488 netfile = list_entry(tmp2, struct cifsFileInfo,
489 tlist);
490 if (pSMB->Fid != netfile->fid.netfid)
491 continue;
492
493 cifs_dbg(FYI, "file id match, oplock break\n");
494 pCifsInode = CIFS_I(d_inode(netfile->dentry));
495
496 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
497 &pCifsInode->flags);
498
499 netfile->oplock_epoch = 0;
500 netfile->oplock_level = pSMB->OplockLevel;
501 netfile->oplock_break_cancelled = false;
502 cifs_queue_oplock_break(netfile);
503
504 spin_unlock(&tcon->open_file_lock);
505 spin_unlock(&cifs_tcp_ses_lock);
506 return true;
507 }
508 spin_unlock(&tcon->open_file_lock);
509 spin_unlock(&cifs_tcp_ses_lock);
510 cifs_dbg(FYI, "No matching file for oplock break\n");
511 return true;
512 }
513 }
514 spin_unlock(&cifs_tcp_ses_lock);
515 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
516 return true;
517 }
518
519 void
dump_smb(void * buf,int smb_buf_length)520 dump_smb(void *buf, int smb_buf_length)
521 {
522 if (traceSMB == 0)
523 return;
524
525 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
526 smb_buf_length, true);
527 }
528
529 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)530 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
531 {
532 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
533 struct cifs_tcon *tcon = NULL;
534
535 if (cifs_sb->master_tlink)
536 tcon = cifs_sb_master_tcon(cifs_sb);
537
538 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
539 cifs_sb->mnt_cifs_serverino_autodisabled = true;
540 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
541 tcon ? tcon->treeName : "new server");
542 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
543 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
544
545 }
546 }
547
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)548 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
549 {
550 oplock &= 0xF;
551
552 if (oplock == OPLOCK_EXCLUSIVE) {
553 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
554 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
555 &cinode->vfs_inode);
556 } else if (oplock == OPLOCK_READ) {
557 cinode->oplock = CIFS_CACHE_READ_FLG;
558 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
559 &cinode->vfs_inode);
560 } else
561 cinode->oplock = 0;
562 }
563
564 /*
565 * We wait for oplock breaks to be processed before we attempt to perform
566 * writes.
567 */
cifs_get_writer(struct cifsInodeInfo * cinode)568 int cifs_get_writer(struct cifsInodeInfo *cinode)
569 {
570 int rc;
571
572 start:
573 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
574 TASK_KILLABLE);
575 if (rc)
576 return rc;
577
578 spin_lock(&cinode->writers_lock);
579 if (!cinode->writers)
580 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
581 cinode->writers++;
582 /* Check to see if we have started servicing an oplock break */
583 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
584 cinode->writers--;
585 if (cinode->writers == 0) {
586 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
587 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
588 }
589 spin_unlock(&cinode->writers_lock);
590 goto start;
591 }
592 spin_unlock(&cinode->writers_lock);
593 return 0;
594 }
595
cifs_put_writer(struct cifsInodeInfo * cinode)596 void cifs_put_writer(struct cifsInodeInfo *cinode)
597 {
598 spin_lock(&cinode->writers_lock);
599 cinode->writers--;
600 if (cinode->writers == 0) {
601 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
602 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
603 }
604 spin_unlock(&cinode->writers_lock);
605 }
606
607 /**
608 * cifs_queue_oplock_break - queue the oplock break handler for cfile
609 *
610 * This function is called from the demultiplex thread when it
611 * receives an oplock break for @cfile.
612 *
613 * Assumes the tcon->open_file_lock is held.
614 * Assumes cfile->file_info_lock is NOT held.
615 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)616 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
617 {
618 /*
619 * Bump the handle refcount now while we hold the
620 * open_file_lock to enforce the validity of it for the oplock
621 * break handler. The matching put is done at the end of the
622 * handler.
623 */
624 cifsFileInfo_get(cfile);
625
626 queue_work(cifsoplockd_wq, &cfile->oplock_break);
627 }
628
cifs_done_oplock_break(struct cifsInodeInfo * cinode)629 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
630 {
631 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
632 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
633 }
634
635 bool
backup_cred(struct cifs_sb_info * cifs_sb)636 backup_cred(struct cifs_sb_info *cifs_sb)
637 {
638 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
639 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
640 return true;
641 }
642 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
643 if (in_group_p(cifs_sb->mnt_backupgid))
644 return true;
645 }
646
647 return false;
648 }
649
650 void
cifs_del_pending_open(struct cifs_pending_open * open)651 cifs_del_pending_open(struct cifs_pending_open *open)
652 {
653 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
654 list_del(&open->olist);
655 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
656 }
657
658 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)659 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
660 struct cifs_pending_open *open)
661 {
662 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
663 open->oplock = CIFS_OPLOCK_NO_CHANGE;
664 open->tlink = tlink;
665 fid->pending_open = open;
666 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
667 }
668
669 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)670 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
671 struct cifs_pending_open *open)
672 {
673 spin_lock(&tlink_tcon(tlink)->open_file_lock);
674 cifs_add_pending_open_locked(fid, tlink, open);
675 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
676 }
677
678 /* parses DFS refferal V3 structure
679 * caller is responsible for freeing target_nodes
680 * returns:
681 * - on success - 0
682 * - on failure - errno
683 */
684 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)685 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
686 unsigned int *num_of_nodes,
687 struct dfs_info3_param **target_nodes,
688 const struct nls_table *nls_codepage, int remap,
689 const char *searchName, bool is_unicode)
690 {
691 int i, rc = 0;
692 char *data_end;
693 struct dfs_referral_level_3 *ref;
694
695 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
696
697 if (*num_of_nodes < 1) {
698 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
699 *num_of_nodes);
700 rc = -EINVAL;
701 goto parse_DFS_referrals_exit;
702 }
703
704 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
705 if (ref->VersionNumber != cpu_to_le16(3)) {
706 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
707 le16_to_cpu(ref->VersionNumber));
708 rc = -EINVAL;
709 goto parse_DFS_referrals_exit;
710 }
711
712 /* get the upper boundary of the resp buffer */
713 data_end = (char *)rsp + rsp_size;
714
715 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
716 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
717
718 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
719 GFP_KERNEL);
720 if (*target_nodes == NULL) {
721 rc = -ENOMEM;
722 goto parse_DFS_referrals_exit;
723 }
724
725 /* collect necessary data from referrals */
726 for (i = 0; i < *num_of_nodes; i++) {
727 char *temp;
728 int max_len;
729 struct dfs_info3_param *node = (*target_nodes)+i;
730
731 node->flags = le32_to_cpu(rsp->DFSFlags);
732 if (is_unicode) {
733 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
734 GFP_KERNEL);
735 if (tmp == NULL) {
736 rc = -ENOMEM;
737 goto parse_DFS_referrals_exit;
738 }
739 cifsConvertToUTF16((__le16 *) tmp, searchName,
740 PATH_MAX, nls_codepage, remap);
741 node->path_consumed = cifs_utf16_bytes(tmp,
742 le16_to_cpu(rsp->PathConsumed),
743 nls_codepage);
744 kfree(tmp);
745 } else
746 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
747
748 node->server_type = le16_to_cpu(ref->ServerType);
749 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
750
751 /* copy DfsPath */
752 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
753 max_len = data_end - temp;
754 node->path_name = cifs_strndup_from_utf16(temp, max_len,
755 is_unicode, nls_codepage);
756 if (!node->path_name) {
757 rc = -ENOMEM;
758 goto parse_DFS_referrals_exit;
759 }
760
761 /* copy link target UNC */
762 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
763 max_len = data_end - temp;
764 node->node_name = cifs_strndup_from_utf16(temp, max_len,
765 is_unicode, nls_codepage);
766 if (!node->node_name) {
767 rc = -ENOMEM;
768 goto parse_DFS_referrals_exit;
769 }
770
771 node->ttl = le32_to_cpu(ref->TimeToLive);
772
773 ref++;
774 }
775
776 parse_DFS_referrals_exit:
777 if (rc) {
778 free_dfs_info_array(*target_nodes, *num_of_nodes);
779 *target_nodes = NULL;
780 *num_of_nodes = 0;
781 }
782 return rc;
783 }
784
785 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)786 cifs_aio_ctx_alloc(void)
787 {
788 struct cifs_aio_ctx *ctx;
789
790 /*
791 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
792 * to false so that we know when we have to unreference pages within
793 * cifs_aio_ctx_release()
794 */
795 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
796 if (!ctx)
797 return NULL;
798
799 INIT_LIST_HEAD(&ctx->list);
800 mutex_init(&ctx->aio_mutex);
801 init_completion(&ctx->done);
802 kref_init(&ctx->refcount);
803 return ctx;
804 }
805
806 void
cifs_aio_ctx_release(struct kref * refcount)807 cifs_aio_ctx_release(struct kref *refcount)
808 {
809 struct cifs_aio_ctx *ctx = container_of(refcount,
810 struct cifs_aio_ctx, refcount);
811
812 cifsFileInfo_put(ctx->cfile);
813
814 /*
815 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
816 * which means that iov_iter_get_pages() was a success and thus that
817 * we have taken reference on pages.
818 */
819 if (ctx->bv) {
820 unsigned i;
821
822 for (i = 0; i < ctx->npages; i++) {
823 if (ctx->should_dirty)
824 set_page_dirty(ctx->bv[i].bv_page);
825 put_page(ctx->bv[i].bv_page);
826 }
827 kvfree(ctx->bv);
828 }
829
830 kfree(ctx);
831 }
832
833 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
834
835 int
setup_aio_ctx_iter(struct cifs_aio_ctx * ctx,struct iov_iter * iter,int rw)836 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
837 {
838 ssize_t rc;
839 unsigned int cur_npages;
840 unsigned int npages = 0;
841 unsigned int i;
842 size_t len;
843 size_t count = iov_iter_count(iter);
844 unsigned int saved_len;
845 size_t start;
846 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
847 struct page **pages = NULL;
848 struct bio_vec *bv = NULL;
849
850 if (iov_iter_is_kvec(iter)) {
851 memcpy(&ctx->iter, iter, sizeof(*iter));
852 ctx->len = count;
853 iov_iter_advance(iter, count);
854 return 0;
855 }
856
857 if (array_size(max_pages, sizeof(*bv)) <= CIFS_AIO_KMALLOC_LIMIT)
858 bv = kmalloc_array(max_pages, sizeof(*bv), GFP_KERNEL);
859
860 if (!bv) {
861 bv = vmalloc(array_size(max_pages, sizeof(*bv)));
862 if (!bv)
863 return -ENOMEM;
864 }
865
866 if (array_size(max_pages, sizeof(*pages)) <= CIFS_AIO_KMALLOC_LIMIT)
867 pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
868
869 if (!pages) {
870 pages = vmalloc(array_size(max_pages, sizeof(*pages)));
871 if (!pages) {
872 kvfree(bv);
873 return -ENOMEM;
874 }
875 }
876
877 saved_len = count;
878
879 while (count && npages < max_pages) {
880 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
881 if (rc < 0) {
882 cifs_dbg(VFS, "Couldn't get user pages (rc=%zd)\n", rc);
883 break;
884 }
885
886 if (rc > count) {
887 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
888 count);
889 break;
890 }
891
892 iov_iter_advance(iter, rc);
893 count -= rc;
894 rc += start;
895 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
896
897 if (npages + cur_npages > max_pages) {
898 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
899 npages + cur_npages, max_pages);
900 break;
901 }
902
903 for (i = 0; i < cur_npages; i++) {
904 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
905 bv[npages + i].bv_page = pages[i];
906 bv[npages + i].bv_offset = start;
907 bv[npages + i].bv_len = len - start;
908 rc -= len;
909 start = 0;
910 }
911
912 npages += cur_npages;
913 }
914
915 kvfree(pages);
916 ctx->bv = bv;
917 ctx->len = saved_len - count;
918 ctx->npages = npages;
919 iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
920 return 0;
921 }
922
923 /**
924 * cifs_alloc_hash - allocate hash and hash context together
925 *
926 * The caller has to make sure @sdesc is initialized to either NULL or
927 * a valid context. Both can be freed via cifs_free_hash().
928 */
929 int
cifs_alloc_hash(const char * name,struct crypto_shash ** shash,struct sdesc ** sdesc)930 cifs_alloc_hash(const char *name,
931 struct crypto_shash **shash, struct sdesc **sdesc)
932 {
933 int rc = 0;
934 size_t size;
935
936 if (*sdesc != NULL)
937 return 0;
938
939 *shash = crypto_alloc_shash(name, 0, 0);
940 if (IS_ERR(*shash)) {
941 cifs_dbg(VFS, "Could not allocate crypto %s\n", name);
942 rc = PTR_ERR(*shash);
943 *shash = NULL;
944 *sdesc = NULL;
945 return rc;
946 }
947
948 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
949 *sdesc = kmalloc(size, GFP_KERNEL);
950 if (*sdesc == NULL) {
951 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
952 crypto_free_shash(*shash);
953 *shash = NULL;
954 return -ENOMEM;
955 }
956
957 (*sdesc)->shash.tfm = *shash;
958 return 0;
959 }
960
961 /**
962 * cifs_free_hash - free hash and hash context together
963 *
964 * Freeing a NULL hash or context is safe.
965 */
966 void
cifs_free_hash(struct crypto_shash ** shash,struct sdesc ** sdesc)967 cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
968 {
969 kfree(*sdesc);
970 *sdesc = NULL;
971 if (*shash)
972 crypto_free_shash(*shash);
973 *shash = NULL;
974 }
975
976 /**
977 * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
978 * Input: rqst - a smb_rqst, page - a page index for rqst
979 * Output: *len - the length for this page, *offset - the offset for this page
980 */
rqst_page_get_length(const struct smb_rqst * rqst,unsigned int page,unsigned int * len,unsigned int * offset)981 void rqst_page_get_length(const struct smb_rqst *rqst, unsigned int page,
982 unsigned int *len, unsigned int *offset)
983 {
984 *len = rqst->rq_pagesz;
985 *offset = (page == 0) ? rqst->rq_offset : 0;
986
987 if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
988 *len = rqst->rq_tailsz;
989 else if (page == 0)
990 *len = rqst->rq_pagesz - rqst->rq_offset;
991 }
992
extract_unc_hostname(const char * unc,const char ** h,size_t * len)993 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
994 {
995 const char *end;
996
997 /* skip initial slashes */
998 while (*unc && (*unc == '\\' || *unc == '/'))
999 unc++;
1000
1001 end = unc;
1002
1003 while (*end && !(*end == '\\' || *end == '/'))
1004 end++;
1005
1006 *h = unc;
1007 *len = end - unc;
1008 }
1009
1010 /**
1011 * copy_path_name - copy src path to dst, possibly truncating
1012 *
1013 * returns number of bytes written (including trailing nul)
1014 */
copy_path_name(char * dst,const char * src)1015 int copy_path_name(char *dst, const char *src)
1016 {
1017 int name_len;
1018
1019 /*
1020 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1021 * will truncate and strlen(dst) will be PATH_MAX-1
1022 */
1023 name_len = strscpy(dst, src, PATH_MAX);
1024 if (WARN_ON_ONCE(name_len < 0))
1025 name_len = PATH_MAX-1;
1026
1027 /* we count the trailing nul */
1028 name_len++;
1029 return name_len;
1030 }
1031
1032 struct super_cb_data {
1033 void *data;
1034 struct super_block *sb;
1035 };
1036
tcp_super_cb(struct super_block * sb,void * arg)1037 static void tcp_super_cb(struct super_block *sb, void *arg)
1038 {
1039 struct super_cb_data *sd = arg;
1040 struct TCP_Server_Info *server = sd->data;
1041 struct cifs_sb_info *cifs_sb;
1042 struct cifs_tcon *tcon;
1043
1044 if (sd->sb)
1045 return;
1046
1047 cifs_sb = CIFS_SB(sb);
1048 tcon = cifs_sb_master_tcon(cifs_sb);
1049 if (tcon->ses->server == server)
1050 sd->sb = sb;
1051 }
1052
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)1053 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1054 void *data)
1055 {
1056 struct super_cb_data sd = {
1057 .data = data,
1058 .sb = NULL,
1059 };
1060 struct file_system_type **fs_type = (struct file_system_type *[]) {
1061 &cifs_fs_type, &smb3_fs_type, NULL,
1062 };
1063
1064 for (; *fs_type; fs_type++) {
1065 iterate_supers_type(*fs_type, f, &sd);
1066 if (sd.sb) {
1067 /*
1068 * Grab an active reference in order to prevent automounts (DFS links)
1069 * of expiring and then freeing up our cifs superblock pointer while
1070 * we're doing failover.
1071 */
1072 cifs_sb_active(sd.sb);
1073 return sd.sb;
1074 }
1075 }
1076 return ERR_PTR(-EINVAL);
1077 }
1078
__cifs_put_super(struct super_block * sb)1079 static void __cifs_put_super(struct super_block *sb)
1080 {
1081 if (!IS_ERR_OR_NULL(sb))
1082 cifs_sb_deactive(sb);
1083 }
1084
cifs_get_tcp_super(struct TCP_Server_Info * server)1085 struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server)
1086 {
1087 return __cifs_get_super(tcp_super_cb, server);
1088 }
1089
cifs_put_tcp_super(struct super_block * sb)1090 void cifs_put_tcp_super(struct super_block *sb)
1091 {
1092 __cifs_put_super(sb);
1093 }
1094
1095 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * share,size_t share_len,bool * result)1096 int match_target_ip(struct TCP_Server_Info *server,
1097 const char *share, size_t share_len,
1098 bool *result)
1099 {
1100 int rc;
1101 char *target, *tip = NULL;
1102 struct sockaddr tipaddr;
1103
1104 *result = false;
1105
1106 target = kzalloc(share_len + 3, GFP_KERNEL);
1107 if (!target) {
1108 rc = -ENOMEM;
1109 goto out;
1110 }
1111
1112 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1113
1114 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1115
1116 rc = dns_resolve_server_name_to_ip(target, &tip);
1117 if (rc < 0)
1118 goto out;
1119
1120 cifs_dbg(FYI, "%s: target ip: %s\n", __func__, tip);
1121
1122 if (!cifs_convert_address(&tipaddr, tip, strlen(tip))) {
1123 cifs_dbg(VFS, "%s: failed to convert target ip address\n",
1124 __func__);
1125 rc = -EINVAL;
1126 goto out;
1127 }
1128
1129 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr,
1130 &tipaddr);
1131 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1132 rc = 0;
1133
1134 out:
1135 kfree(target);
1136 kfree(tip);
1137
1138 return rc;
1139 }
1140
tcon_super_cb(struct super_block * sb,void * arg)1141 static void tcon_super_cb(struct super_block *sb, void *arg)
1142 {
1143 struct super_cb_data *sd = arg;
1144 struct cifs_tcon *tcon = sd->data;
1145 struct cifs_sb_info *cifs_sb;
1146
1147 if (sd->sb)
1148 return;
1149
1150 cifs_sb = CIFS_SB(sb);
1151 if (tcon->dfs_path && cifs_sb->origin_fullpath &&
1152 !strcasecmp(tcon->dfs_path, cifs_sb->origin_fullpath))
1153 sd->sb = sb;
1154 }
1155
cifs_get_tcon_super(struct cifs_tcon * tcon)1156 static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon)
1157 {
1158 return __cifs_get_super(tcon_super_cb, tcon);
1159 }
1160
cifs_put_tcon_super(struct super_block * sb)1161 static inline void cifs_put_tcon_super(struct super_block *sb)
1162 {
1163 __cifs_put_super(sb);
1164 }
1165 #else
cifs_get_tcon_super(struct cifs_tcon * tcon)1166 static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon)
1167 {
1168 return ERR_PTR(-EOPNOTSUPP);
1169 }
1170
cifs_put_tcon_super(struct super_block * sb)1171 static inline void cifs_put_tcon_super(struct super_block *sb)
1172 {
1173 }
1174 #endif
1175
update_super_prepath(struct cifs_tcon * tcon,char * prefix)1176 int update_super_prepath(struct cifs_tcon *tcon, char *prefix)
1177 {
1178 struct super_block *sb;
1179 struct cifs_sb_info *cifs_sb;
1180 int rc = 0;
1181
1182 sb = cifs_get_tcon_super(tcon);
1183 if (IS_ERR(sb))
1184 return PTR_ERR(sb);
1185
1186 cifs_sb = CIFS_SB(sb);
1187
1188 kfree(cifs_sb->prepath);
1189
1190 if (prefix && *prefix) {
1191 cifs_sb->prepath = kstrndup(prefix, strlen(prefix), GFP_ATOMIC);
1192 if (!cifs_sb->prepath) {
1193 rc = -ENOMEM;
1194 goto out;
1195 }
1196
1197 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1198 } else
1199 cifs_sb->prepath = NULL;
1200
1201 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1202
1203 out:
1204 cifs_put_tcon_super(sb);
1205 return rc;
1206 }
1207