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 }
357
358 /* otherwise, there is enough to get to the BCC */
359 if (check_smb_hdr(smb))
360 return -EIO;
361 clc_len = smbCalcSize(smb, server);
362
363 if (4 + rfclen != total_read) {
364 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
365 rfclen);
366 return -EIO;
367 }
368
369 if (4 + rfclen != clc_len) {
370 __u16 mid = get_mid(smb);
371 /* check if bcc wrapped around for large read responses */
372 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
373 /* check if lengths match mod 64K */
374 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
375 return 0; /* bcc wrapped */
376 }
377 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
378 clc_len, 4 + rfclen, mid);
379
380 if (4 + rfclen < clc_len) {
381 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
382 rfclen, mid);
383 return -EIO;
384 } else if (rfclen > clc_len + 512) {
385 /*
386 * Some servers (Windows XP in particular) send more
387 * data than the lengths in the SMB packet would
388 * indicate on certain calls (byte range locks and
389 * trans2 find first calls in particular). While the
390 * client can handle such a frame by ignoring the
391 * trailing data, we choose limit the amount of extra
392 * data to 512 bytes.
393 */
394 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
395 rfclen, mid);
396 return -EIO;
397 }
398 }
399 return 0;
400 }
401
402 bool
is_valid_oplock_break(char * buffer,struct TCP_Server_Info * srv)403 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
404 {
405 struct smb_hdr *buf = (struct smb_hdr *)buffer;
406 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
407 struct list_head *tmp, *tmp1, *tmp2;
408 struct cifs_ses *ses;
409 struct cifs_tcon *tcon;
410 struct cifsInodeInfo *pCifsInode;
411 struct cifsFileInfo *netfile;
412
413 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
414 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
415 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
416 struct smb_com_transaction_change_notify_rsp *pSMBr =
417 (struct smb_com_transaction_change_notify_rsp *)buf;
418 struct file_notify_information *pnotify;
419 __u32 data_offset = 0;
420 size_t len = srv->total_read - sizeof(pSMBr->hdr.smb_buf_length);
421
422 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
423 data_offset = le32_to_cpu(pSMBr->DataOffset);
424
425 if (data_offset >
426 len - sizeof(struct file_notify_information)) {
427 cifs_dbg(FYI, "Invalid data_offset %u\n",
428 data_offset);
429 return true;
430 }
431 pnotify = (struct file_notify_information *)
432 ((char *)&pSMBr->hdr.Protocol + data_offset);
433 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
434 pnotify->FileName, pnotify->Action);
435 /* cifs_dump_mem("Rcvd notify Data: ",buf,
436 sizeof(struct smb_hdr)+60); */
437 return true;
438 }
439 if (pSMBr->hdr.Status.CifsError) {
440 cifs_dbg(FYI, "notify err 0x%x\n",
441 pSMBr->hdr.Status.CifsError);
442 return true;
443 }
444 return false;
445 }
446 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
447 return false;
448 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
449 /* no sense logging error on invalid handle on oplock
450 break - harmless race between close request and oplock
451 break response is expected from time to time writing out
452 large dirty files cached on the client */
453 if ((NT_STATUS_INVALID_HANDLE) ==
454 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
455 cifs_dbg(FYI, "Invalid handle on oplock break\n");
456 return true;
457 } else if (ERRbadfid ==
458 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
459 return true;
460 } else {
461 return false; /* on valid oplock brk we get "request" */
462 }
463 }
464 if (pSMB->hdr.WordCount != 8)
465 return false;
466
467 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
468 pSMB->LockType, pSMB->OplockLevel);
469 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
470 return false;
471
472 /* look up tcon based on tid & uid */
473 spin_lock(&cifs_tcp_ses_lock);
474 list_for_each(tmp, &srv->smb_ses_list) {
475 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
476 list_for_each(tmp1, &ses->tcon_list) {
477 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
478 if (tcon->tid != buf->Tid)
479 continue;
480
481 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
482 spin_lock(&tcon->open_file_lock);
483 list_for_each(tmp2, &tcon->openFileList) {
484 netfile = list_entry(tmp2, struct cifsFileInfo,
485 tlist);
486 if (pSMB->Fid != netfile->fid.netfid)
487 continue;
488
489 cifs_dbg(FYI, "file id match, oplock break\n");
490 pCifsInode = CIFS_I(d_inode(netfile->dentry));
491
492 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
493 &pCifsInode->flags);
494
495 netfile->oplock_epoch = 0;
496 netfile->oplock_level = pSMB->OplockLevel;
497 netfile->oplock_break_cancelled = false;
498 cifs_queue_oplock_break(netfile);
499
500 spin_unlock(&tcon->open_file_lock);
501 spin_unlock(&cifs_tcp_ses_lock);
502 return true;
503 }
504 spin_unlock(&tcon->open_file_lock);
505 spin_unlock(&cifs_tcp_ses_lock);
506 cifs_dbg(FYI, "No matching file for oplock break\n");
507 return true;
508 }
509 }
510 spin_unlock(&cifs_tcp_ses_lock);
511 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
512 return true;
513 }
514
515 void
dump_smb(void * buf,int smb_buf_length)516 dump_smb(void *buf, int smb_buf_length)
517 {
518 if (traceSMB == 0)
519 return;
520
521 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
522 smb_buf_length, true);
523 }
524
525 void
cifs_autodisable_serverino(struct cifs_sb_info * cifs_sb)526 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
527 {
528 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
529 struct cifs_tcon *tcon = NULL;
530
531 if (cifs_sb->master_tlink)
532 tcon = cifs_sb_master_tcon(cifs_sb);
533
534 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
535 cifs_sb->mnt_cifs_serverino_autodisabled = true;
536 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s\n",
537 tcon ? tcon->treeName : "new server");
538 cifs_dbg(VFS, "The server doesn't seem to support them properly or the files might be on different servers (DFS)\n");
539 cifs_dbg(VFS, "Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n");
540
541 }
542 }
543
cifs_set_oplock_level(struct cifsInodeInfo * cinode,__u32 oplock)544 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
545 {
546 oplock &= 0xF;
547
548 if (oplock == OPLOCK_EXCLUSIVE) {
549 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
550 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
551 &cinode->vfs_inode);
552 } else if (oplock == OPLOCK_READ) {
553 cinode->oplock = CIFS_CACHE_READ_FLG;
554 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
555 &cinode->vfs_inode);
556 } else
557 cinode->oplock = 0;
558 }
559
560 /*
561 * We wait for oplock breaks to be processed before we attempt to perform
562 * writes.
563 */
cifs_get_writer(struct cifsInodeInfo * cinode)564 int cifs_get_writer(struct cifsInodeInfo *cinode)
565 {
566 int rc;
567
568 start:
569 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
570 TASK_KILLABLE);
571 if (rc)
572 return rc;
573
574 spin_lock(&cinode->writers_lock);
575 if (!cinode->writers)
576 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
577 cinode->writers++;
578 /* Check to see if we have started servicing an oplock break */
579 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
580 cinode->writers--;
581 if (cinode->writers == 0) {
582 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
583 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
584 }
585 spin_unlock(&cinode->writers_lock);
586 goto start;
587 }
588 spin_unlock(&cinode->writers_lock);
589 return 0;
590 }
591
cifs_put_writer(struct cifsInodeInfo * cinode)592 void cifs_put_writer(struct cifsInodeInfo *cinode)
593 {
594 spin_lock(&cinode->writers_lock);
595 cinode->writers--;
596 if (cinode->writers == 0) {
597 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
598 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
599 }
600 spin_unlock(&cinode->writers_lock);
601 }
602
603 /**
604 * cifs_queue_oplock_break - queue the oplock break handler for cfile
605 *
606 * This function is called from the demultiplex thread when it
607 * receives an oplock break for @cfile.
608 *
609 * Assumes the tcon->open_file_lock is held.
610 * Assumes cfile->file_info_lock is NOT held.
611 */
cifs_queue_oplock_break(struct cifsFileInfo * cfile)612 void cifs_queue_oplock_break(struct cifsFileInfo *cfile)
613 {
614 /*
615 * Bump the handle refcount now while we hold the
616 * open_file_lock to enforce the validity of it for the oplock
617 * break handler. The matching put is done at the end of the
618 * handler.
619 */
620 cifsFileInfo_get(cfile);
621
622 queue_work(cifsoplockd_wq, &cfile->oplock_break);
623 }
624
cifs_done_oplock_break(struct cifsInodeInfo * cinode)625 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
626 {
627 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
628 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
629 }
630
631 bool
backup_cred(struct cifs_sb_info * cifs_sb)632 backup_cred(struct cifs_sb_info *cifs_sb)
633 {
634 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
635 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
636 return true;
637 }
638 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
639 if (in_group_p(cifs_sb->mnt_backupgid))
640 return true;
641 }
642
643 return false;
644 }
645
646 void
cifs_del_pending_open(struct cifs_pending_open * open)647 cifs_del_pending_open(struct cifs_pending_open *open)
648 {
649 spin_lock(&tlink_tcon(open->tlink)->open_file_lock);
650 list_del(&open->olist);
651 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
652 }
653
654 void
cifs_add_pending_open_locked(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)655 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
656 struct cifs_pending_open *open)
657 {
658 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
659 open->oplock = CIFS_OPLOCK_NO_CHANGE;
660 open->tlink = tlink;
661 fid->pending_open = open;
662 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
663 }
664
665 void
cifs_add_pending_open(struct cifs_fid * fid,struct tcon_link * tlink,struct cifs_pending_open * open)666 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
667 struct cifs_pending_open *open)
668 {
669 spin_lock(&tlink_tcon(tlink)->open_file_lock);
670 cifs_add_pending_open_locked(fid, tlink, open);
671 spin_unlock(&tlink_tcon(open->tlink)->open_file_lock);
672 }
673
674 /* parses DFS refferal V3 structure
675 * caller is responsible for freeing target_nodes
676 * returns:
677 * - on success - 0
678 * - on failure - errno
679 */
680 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)681 parse_dfs_referrals(struct get_dfs_referral_rsp *rsp, u32 rsp_size,
682 unsigned int *num_of_nodes,
683 struct dfs_info3_param **target_nodes,
684 const struct nls_table *nls_codepage, int remap,
685 const char *searchName, bool is_unicode)
686 {
687 int i, rc = 0;
688 char *data_end;
689 struct dfs_referral_level_3 *ref;
690
691 *num_of_nodes = le16_to_cpu(rsp->NumberOfReferrals);
692
693 if (*num_of_nodes < 1) {
694 cifs_dbg(VFS, "num_referrals: must be at least > 0, but we get num_referrals = %d\n",
695 *num_of_nodes);
696 rc = -EINVAL;
697 goto parse_DFS_referrals_exit;
698 }
699
700 ref = (struct dfs_referral_level_3 *) &(rsp->referrals);
701 if (ref->VersionNumber != cpu_to_le16(3)) {
702 cifs_dbg(VFS, "Referrals of V%d version are not supported, should be V3\n",
703 le16_to_cpu(ref->VersionNumber));
704 rc = -EINVAL;
705 goto parse_DFS_referrals_exit;
706 }
707
708 /* get the upper boundary of the resp buffer */
709 data_end = (char *)rsp + rsp_size;
710
711 cifs_dbg(FYI, "num_referrals: %d dfs flags: 0x%x ...\n",
712 *num_of_nodes, le32_to_cpu(rsp->DFSFlags));
713
714 *target_nodes = kcalloc(*num_of_nodes, sizeof(struct dfs_info3_param),
715 GFP_KERNEL);
716 if (*target_nodes == NULL) {
717 rc = -ENOMEM;
718 goto parse_DFS_referrals_exit;
719 }
720
721 /* collect necessary data from referrals */
722 for (i = 0; i < *num_of_nodes; i++) {
723 char *temp;
724 int max_len;
725 struct dfs_info3_param *node = (*target_nodes)+i;
726
727 node->flags = le32_to_cpu(rsp->DFSFlags);
728 if (is_unicode) {
729 __le16 *tmp = kmalloc(strlen(searchName)*2 + 2,
730 GFP_KERNEL);
731 if (tmp == NULL) {
732 rc = -ENOMEM;
733 goto parse_DFS_referrals_exit;
734 }
735 cifsConvertToUTF16((__le16 *) tmp, searchName,
736 PATH_MAX, nls_codepage, remap);
737 node->path_consumed = cifs_utf16_bytes(tmp,
738 le16_to_cpu(rsp->PathConsumed),
739 nls_codepage);
740 kfree(tmp);
741 } else
742 node->path_consumed = le16_to_cpu(rsp->PathConsumed);
743
744 node->server_type = le16_to_cpu(ref->ServerType);
745 node->ref_flag = le16_to_cpu(ref->ReferralEntryFlags);
746
747 /* copy DfsPath */
748 temp = (char *)ref + le16_to_cpu(ref->DfsPathOffset);
749 max_len = data_end - temp;
750 node->path_name = cifs_strndup_from_utf16(temp, max_len,
751 is_unicode, nls_codepage);
752 if (!node->path_name) {
753 rc = -ENOMEM;
754 goto parse_DFS_referrals_exit;
755 }
756
757 /* copy link target UNC */
758 temp = (char *)ref + le16_to_cpu(ref->NetworkAddressOffset);
759 max_len = data_end - temp;
760 node->node_name = cifs_strndup_from_utf16(temp, max_len,
761 is_unicode, nls_codepage);
762 if (!node->node_name) {
763 rc = -ENOMEM;
764 goto parse_DFS_referrals_exit;
765 }
766
767 node->ttl = le32_to_cpu(ref->TimeToLive);
768
769 ref++;
770 }
771
772 parse_DFS_referrals_exit:
773 if (rc) {
774 free_dfs_info_array(*target_nodes, *num_of_nodes);
775 *target_nodes = NULL;
776 *num_of_nodes = 0;
777 }
778 return rc;
779 }
780
781 struct cifs_aio_ctx *
cifs_aio_ctx_alloc(void)782 cifs_aio_ctx_alloc(void)
783 {
784 struct cifs_aio_ctx *ctx;
785
786 /*
787 * Must use kzalloc to initialize ctx->bv to NULL and ctx->direct_io
788 * to false so that we know when we have to unreference pages within
789 * cifs_aio_ctx_release()
790 */
791 ctx = kzalloc(sizeof(struct cifs_aio_ctx), GFP_KERNEL);
792 if (!ctx)
793 return NULL;
794
795 INIT_LIST_HEAD(&ctx->list);
796 mutex_init(&ctx->aio_mutex);
797 init_completion(&ctx->done);
798 kref_init(&ctx->refcount);
799 return ctx;
800 }
801
802 void
cifs_aio_ctx_release(struct kref * refcount)803 cifs_aio_ctx_release(struct kref *refcount)
804 {
805 struct cifs_aio_ctx *ctx = container_of(refcount,
806 struct cifs_aio_ctx, refcount);
807
808 cifsFileInfo_put(ctx->cfile);
809
810 /*
811 * ctx->bv is only set if setup_aio_ctx_iter() was call successfuly
812 * which means that iov_iter_get_pages() was a success and thus that
813 * we have taken reference on pages.
814 */
815 if (ctx->bv) {
816 unsigned i;
817
818 for (i = 0; i < ctx->npages; i++) {
819 if (ctx->should_dirty)
820 set_page_dirty(ctx->bv[i].bv_page);
821 put_page(ctx->bv[i].bv_page);
822 }
823 kvfree(ctx->bv);
824 }
825
826 kfree(ctx);
827 }
828
829 #define CIFS_AIO_KMALLOC_LIMIT (1024 * 1024)
830
831 int
setup_aio_ctx_iter(struct cifs_aio_ctx * ctx,struct iov_iter * iter,int rw)832 setup_aio_ctx_iter(struct cifs_aio_ctx *ctx, struct iov_iter *iter, int rw)
833 {
834 ssize_t rc;
835 unsigned int cur_npages;
836 unsigned int npages = 0;
837 unsigned int i;
838 size_t len;
839 size_t count = iov_iter_count(iter);
840 unsigned int saved_len;
841 size_t start;
842 unsigned int max_pages = iov_iter_npages(iter, INT_MAX);
843 struct page **pages = NULL;
844 struct bio_vec *bv = NULL;
845
846 if (iov_iter_is_kvec(iter)) {
847 memcpy(&ctx->iter, iter, sizeof(*iter));
848 ctx->len = count;
849 iov_iter_advance(iter, count);
850 return 0;
851 }
852
853 if (array_size(max_pages, sizeof(*bv)) <= CIFS_AIO_KMALLOC_LIMIT)
854 bv = kmalloc_array(max_pages, sizeof(*bv), GFP_KERNEL);
855
856 if (!bv) {
857 bv = vmalloc(array_size(max_pages, sizeof(*bv)));
858 if (!bv)
859 return -ENOMEM;
860 }
861
862 if (array_size(max_pages, sizeof(*pages)) <= CIFS_AIO_KMALLOC_LIMIT)
863 pages = kmalloc_array(max_pages, sizeof(*pages), GFP_KERNEL);
864
865 if (!pages) {
866 pages = vmalloc(array_size(max_pages, sizeof(*pages)));
867 if (!pages) {
868 kvfree(bv);
869 return -ENOMEM;
870 }
871 }
872
873 saved_len = count;
874
875 while (count && npages < max_pages) {
876 rc = iov_iter_get_pages(iter, pages, count, max_pages, &start);
877 if (rc < 0) {
878 cifs_dbg(VFS, "Couldn't get user pages (rc=%zd)\n", rc);
879 break;
880 }
881
882 if (rc > count) {
883 cifs_dbg(VFS, "get pages rc=%zd more than %zu\n", rc,
884 count);
885 break;
886 }
887
888 iov_iter_advance(iter, rc);
889 count -= rc;
890 rc += start;
891 cur_npages = DIV_ROUND_UP(rc, PAGE_SIZE);
892
893 if (npages + cur_npages > max_pages) {
894 cifs_dbg(VFS, "out of vec array capacity (%u vs %u)\n",
895 npages + cur_npages, max_pages);
896 break;
897 }
898
899 for (i = 0; i < cur_npages; i++) {
900 len = rc > PAGE_SIZE ? PAGE_SIZE : rc;
901 bv[npages + i].bv_page = pages[i];
902 bv[npages + i].bv_offset = start;
903 bv[npages + i].bv_len = len - start;
904 rc -= len;
905 start = 0;
906 }
907
908 npages += cur_npages;
909 }
910
911 kvfree(pages);
912 ctx->bv = bv;
913 ctx->len = saved_len - count;
914 ctx->npages = npages;
915 iov_iter_bvec(&ctx->iter, rw, ctx->bv, npages, ctx->len);
916 return 0;
917 }
918
919 /**
920 * cifs_alloc_hash - allocate hash and hash context together
921 *
922 * The caller has to make sure @sdesc is initialized to either NULL or
923 * a valid context. Both can be freed via cifs_free_hash().
924 */
925 int
cifs_alloc_hash(const char * name,struct crypto_shash ** shash,struct sdesc ** sdesc)926 cifs_alloc_hash(const char *name,
927 struct crypto_shash **shash, struct sdesc **sdesc)
928 {
929 int rc = 0;
930 size_t size;
931
932 if (*sdesc != NULL)
933 return 0;
934
935 *shash = crypto_alloc_shash(name, 0, 0);
936 if (IS_ERR(*shash)) {
937 cifs_dbg(VFS, "Could not allocate crypto %s\n", name);
938 rc = PTR_ERR(*shash);
939 *shash = NULL;
940 *sdesc = NULL;
941 return rc;
942 }
943
944 size = sizeof(struct shash_desc) + crypto_shash_descsize(*shash);
945 *sdesc = kmalloc(size, GFP_KERNEL);
946 if (*sdesc == NULL) {
947 cifs_dbg(VFS, "no memory left to allocate crypto %s\n", name);
948 crypto_free_shash(*shash);
949 *shash = NULL;
950 return -ENOMEM;
951 }
952
953 (*sdesc)->shash.tfm = *shash;
954 return 0;
955 }
956
957 /**
958 * cifs_free_hash - free hash and hash context together
959 *
960 * Freeing a NULL hash or context is safe.
961 */
962 void
cifs_free_hash(struct crypto_shash ** shash,struct sdesc ** sdesc)963 cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
964 {
965 kfree(*sdesc);
966 *sdesc = NULL;
967 if (*shash)
968 crypto_free_shash(*shash);
969 *shash = NULL;
970 }
971
972 /**
973 * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
974 * Input: rqst - a smb_rqst, page - a page index for rqst
975 * Output: *len - the length for this page, *offset - the offset for this page
976 */
rqst_page_get_length(struct smb_rqst * rqst,unsigned int page,unsigned int * len,unsigned int * offset)977 void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
978 unsigned int *len, unsigned int *offset)
979 {
980 *len = rqst->rq_pagesz;
981 *offset = (page == 0) ? rqst->rq_offset : 0;
982
983 if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
984 *len = rqst->rq_tailsz;
985 else if (page == 0)
986 *len = rqst->rq_pagesz - rqst->rq_offset;
987 }
988
extract_unc_hostname(const char * unc,const char ** h,size_t * len)989 void extract_unc_hostname(const char *unc, const char **h, size_t *len)
990 {
991 const char *end;
992
993 /* skip initial slashes */
994 while (*unc && (*unc == '\\' || *unc == '/'))
995 unc++;
996
997 end = unc;
998
999 while (*end && !(*end == '\\' || *end == '/'))
1000 end++;
1001
1002 *h = unc;
1003 *len = end - unc;
1004 }
1005
1006 /**
1007 * copy_path_name - copy src path to dst, possibly truncating
1008 *
1009 * returns number of bytes written (including trailing nul)
1010 */
copy_path_name(char * dst,const char * src)1011 int copy_path_name(char *dst, const char *src)
1012 {
1013 int name_len;
1014
1015 /*
1016 * PATH_MAX includes nul, so if strlen(src) >= PATH_MAX it
1017 * will truncate and strlen(dst) will be PATH_MAX-1
1018 */
1019 name_len = strscpy(dst, src, PATH_MAX);
1020 if (WARN_ON_ONCE(name_len < 0))
1021 name_len = PATH_MAX-1;
1022
1023 /* we count the trailing nul */
1024 name_len++;
1025 return name_len;
1026 }
1027
1028 struct super_cb_data {
1029 void *data;
1030 struct super_block *sb;
1031 };
1032
tcp_super_cb(struct super_block * sb,void * arg)1033 static void tcp_super_cb(struct super_block *sb, void *arg)
1034 {
1035 struct super_cb_data *sd = arg;
1036 struct TCP_Server_Info *server = sd->data;
1037 struct cifs_sb_info *cifs_sb;
1038 struct cifs_tcon *tcon;
1039
1040 if (sd->sb)
1041 return;
1042
1043 cifs_sb = CIFS_SB(sb);
1044 tcon = cifs_sb_master_tcon(cifs_sb);
1045 if (tcon->ses->server == server)
1046 sd->sb = sb;
1047 }
1048
__cifs_get_super(void (* f)(struct super_block *,void *),void * data)1049 static struct super_block *__cifs_get_super(void (*f)(struct super_block *, void *),
1050 void *data)
1051 {
1052 struct super_cb_data sd = {
1053 .data = data,
1054 .sb = NULL,
1055 };
1056
1057 iterate_supers_type(&cifs_fs_type, f, &sd);
1058
1059 if (!sd.sb)
1060 return ERR_PTR(-EINVAL);
1061 /*
1062 * Grab an active reference in order to prevent automounts (DFS links)
1063 * of expiring and then freeing up our cifs superblock pointer while
1064 * we're doing failover.
1065 */
1066 cifs_sb_active(sd.sb);
1067 return sd.sb;
1068 }
1069
__cifs_put_super(struct super_block * sb)1070 static void __cifs_put_super(struct super_block *sb)
1071 {
1072 if (!IS_ERR_OR_NULL(sb))
1073 cifs_sb_deactive(sb);
1074 }
1075
cifs_get_tcp_super(struct TCP_Server_Info * server)1076 struct super_block *cifs_get_tcp_super(struct TCP_Server_Info *server)
1077 {
1078 return __cifs_get_super(tcp_super_cb, server);
1079 }
1080
cifs_put_tcp_super(struct super_block * sb)1081 void cifs_put_tcp_super(struct super_block *sb)
1082 {
1083 __cifs_put_super(sb);
1084 }
1085
1086 #ifdef CONFIG_CIFS_DFS_UPCALL
match_target_ip(struct TCP_Server_Info * server,const char * share,size_t share_len,bool * result)1087 int match_target_ip(struct TCP_Server_Info *server,
1088 const char *share, size_t share_len,
1089 bool *result)
1090 {
1091 int rc;
1092 char *target, *tip = NULL;
1093 struct sockaddr tipaddr;
1094
1095 *result = false;
1096
1097 target = kzalloc(share_len + 3, GFP_KERNEL);
1098 if (!target) {
1099 rc = -ENOMEM;
1100 goto out;
1101 }
1102
1103 scnprintf(target, share_len + 3, "\\\\%.*s", (int)share_len, share);
1104
1105 cifs_dbg(FYI, "%s: target name: %s\n", __func__, target + 2);
1106
1107 rc = dns_resolve_server_name_to_ip(target, &tip);
1108 if (rc < 0)
1109 goto out;
1110
1111 cifs_dbg(FYI, "%s: target ip: %s\n", __func__, tip);
1112
1113 if (!cifs_convert_address(&tipaddr, tip, strlen(tip))) {
1114 cifs_dbg(VFS, "%s: failed to convert target ip address\n",
1115 __func__);
1116 rc = -EINVAL;
1117 goto out;
1118 }
1119
1120 *result = cifs_match_ipaddr((struct sockaddr *)&server->dstaddr,
1121 &tipaddr);
1122 cifs_dbg(FYI, "%s: ip addresses match: %u\n", __func__, *result);
1123 rc = 0;
1124
1125 out:
1126 kfree(target);
1127 kfree(tip);
1128
1129 return rc;
1130 }
1131
tcon_super_cb(struct super_block * sb,void * arg)1132 static void tcon_super_cb(struct super_block *sb, void *arg)
1133 {
1134 struct super_cb_data *sd = arg;
1135 struct cifs_tcon *tcon = sd->data;
1136 struct cifs_sb_info *cifs_sb;
1137
1138 if (sd->sb)
1139 return;
1140
1141 cifs_sb = CIFS_SB(sb);
1142 if (tcon->dfs_path && cifs_sb->origin_fullpath &&
1143 !strcasecmp(tcon->dfs_path, cifs_sb->origin_fullpath))
1144 sd->sb = sb;
1145 }
1146
cifs_get_tcon_super(struct cifs_tcon * tcon)1147 static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon)
1148 {
1149 return __cifs_get_super(tcon_super_cb, tcon);
1150 }
1151
cifs_put_tcon_super(struct super_block * sb)1152 static inline void cifs_put_tcon_super(struct super_block *sb)
1153 {
1154 __cifs_put_super(sb);
1155 }
1156 #else
cifs_get_tcon_super(struct cifs_tcon * tcon)1157 static inline struct super_block *cifs_get_tcon_super(struct cifs_tcon *tcon)
1158 {
1159 return ERR_PTR(-EOPNOTSUPP);
1160 }
1161
cifs_put_tcon_super(struct super_block * sb)1162 static inline void cifs_put_tcon_super(struct super_block *sb)
1163 {
1164 }
1165 #endif
1166
update_super_prepath(struct cifs_tcon * tcon,char * prefix)1167 int update_super_prepath(struct cifs_tcon *tcon, char *prefix)
1168 {
1169 struct super_block *sb;
1170 struct cifs_sb_info *cifs_sb;
1171 int rc = 0;
1172
1173 sb = cifs_get_tcon_super(tcon);
1174 if (IS_ERR(sb))
1175 return PTR_ERR(sb);
1176
1177 cifs_sb = CIFS_SB(sb);
1178
1179 kfree(cifs_sb->prepath);
1180
1181 if (prefix && *prefix) {
1182 cifs_sb->prepath = kstrndup(prefix, strlen(prefix), GFP_ATOMIC);
1183 if (!cifs_sb->prepath) {
1184 rc = -ENOMEM;
1185 goto out;
1186 }
1187
1188 convert_delimiter(cifs_sb->prepath, CIFS_DIR_SEP(cifs_sb));
1189 } else
1190 cifs_sb->prepath = NULL;
1191
1192 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
1193
1194 out:
1195 cifs_put_tcon_super(sb);
1196 return rc;
1197 }
1198