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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 "cifspdu.h"
26#include "cifsglob.h"
27#include "cifsproto.h"
28#include "cifs_debug.h"
29#include "smberr.h"
30#include "nterr.h"
31#include "cifs_unicode.h"
32
33extern mempool_t *cifs_sm_req_poolp;
34extern mempool_t *cifs_req_poolp;
35
36/* The xid serves as a useful identifier for each incoming vfs request,
37 in a similar way to the mid which is useful to track each sent smb,
38 and CurrentXid can also provide a running counter (although it
39 will eventually wrap past zero) of the total vfs operations handled
40 since the cifs fs was mounted */
41
42unsigned int
43_GetXid(void)
44{
45 unsigned int xid;
46
47 spin_lock(&GlobalMid_Lock);
48 GlobalTotalActiveXid++;
49
50 /* keep high water mark for number of simultaneous ops in filesystem */
51 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
52 GlobalMaxActiveXid = GlobalTotalActiveXid;
53 if (GlobalTotalActiveXid > 65000)
54 cFYI(1, "warning: more than 65000 requests active");
55 xid = GlobalCurrentXid++;
56 spin_unlock(&GlobalMid_Lock);
57 return xid;
58}
59
60void
61_FreeXid(unsigned int xid)
62{
63 spin_lock(&GlobalMid_Lock);
64 /* if (GlobalTotalActiveXid == 0)
65 BUG(); */
66 GlobalTotalActiveXid--;
67 spin_unlock(&GlobalMid_Lock);
68}
69
70struct cifs_ses *
71sesInfoAlloc(void)
72{
73 struct cifs_ses *ret_buf;
74
75 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
76 if (ret_buf) {
77 atomic_inc(&sesInfoAllocCount);
78 ret_buf->status = CifsNew;
79 ++ret_buf->ses_count;
80 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
81 INIT_LIST_HEAD(&ret_buf->tcon_list);
82 mutex_init(&ret_buf->session_mutex);
83 }
84 return ret_buf;
85}
86
87void
88sesInfoFree(struct cifs_ses *buf_to_free)
89{
90 if (buf_to_free == NULL) {
91 cFYI(1, "Null buffer passed to sesInfoFree");
92 return;
93 }
94
95 atomic_dec(&sesInfoAllocCount);
96 kfree(buf_to_free->serverOS);
97 kfree(buf_to_free->serverDomain);
98 kfree(buf_to_free->serverNOS);
99 if (buf_to_free->password) {
100 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
101 kfree(buf_to_free->password);
102 }
103 kfree(buf_to_free->user_name);
104 kfree(buf_to_free->domainName);
105 kfree(buf_to_free);
106}
107
108struct cifs_tcon *
109tconInfoAlloc(void)
110{
111 struct cifs_tcon *ret_buf;
112 ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
113 if (ret_buf) {
114 atomic_inc(&tconInfoAllocCount);
115 ret_buf->tidStatus = CifsNew;
116 ++ret_buf->tc_count;
117 INIT_LIST_HEAD(&ret_buf->openFileList);
118 INIT_LIST_HEAD(&ret_buf->tcon_list);
119#ifdef CONFIG_CIFS_STATS
120 spin_lock_init(&ret_buf->stat_lock);
121#endif
122 }
123 return ret_buf;
124}
125
126void
127tconInfoFree(struct cifs_tcon *buf_to_free)
128{
129 if (buf_to_free == NULL) {
130 cFYI(1, "Null buffer passed to tconInfoFree");
131 return;
132 }
133 atomic_dec(&tconInfoAllocCount);
134 kfree(buf_to_free->nativeFileSystem);
135 if (buf_to_free->password) {
136 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
137 kfree(buf_to_free->password);
138 }
139 kfree(buf_to_free);
140}
141
142struct smb_hdr *
143cifs_buf_get(void)
144{
145 struct smb_hdr *ret_buf = NULL;
146
147/* We could use negotiated size instead of max_msgsize -
148 but it may be more efficient to always alloc same size
149 albeit slightly larger than necessary and maxbuffersize
150 defaults to this and can not be bigger */
151 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
152
153 /* clear the first few header bytes */
154 /* for most paths, more is cleared in header_assemble */
155 if (ret_buf) {
156 memset(ret_buf, 0, sizeof(struct smb_hdr) + 3);
157 atomic_inc(&bufAllocCount);
158#ifdef CONFIG_CIFS_STATS2
159 atomic_inc(&totBufAllocCount);
160#endif /* CONFIG_CIFS_STATS2 */
161 }
162
163 return ret_buf;
164}
165
166void
167cifs_buf_release(void *buf_to_free)
168{
169 if (buf_to_free == NULL) {
170 /* cFYI(1, "Null buffer passed to cifs_buf_release");*/
171 return;
172 }
173 mempool_free(buf_to_free, cifs_req_poolp);
174
175 atomic_dec(&bufAllocCount);
176 return;
177}
178
179struct smb_hdr *
180cifs_small_buf_get(void)
181{
182 struct smb_hdr *ret_buf = NULL;
183
184/* We could use negotiated size instead of max_msgsize -
185 but it may be more efficient to always alloc same size
186 albeit slightly larger than necessary and maxbuffersize
187 defaults to this and can not be bigger */
188 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
189 if (ret_buf) {
190 /* No need to clear memory here, cleared in header assemble */
191 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
192 atomic_inc(&smBufAllocCount);
193#ifdef CONFIG_CIFS_STATS2
194 atomic_inc(&totSmBufAllocCount);
195#endif /* CONFIG_CIFS_STATS2 */
196
197 }
198 return ret_buf;
199}
200
201void
202cifs_small_buf_release(void *buf_to_free)
203{
204
205 if (buf_to_free == NULL) {
206 cFYI(1, "Null buffer passed to cifs_small_buf_release");
207 return;
208 }
209 mempool_free(buf_to_free, cifs_sm_req_poolp);
210
211 atomic_dec(&smBufAllocCount);
212 return;
213}
214
215/*
216 Find a free multiplex id (SMB mid). Otherwise there could be
217 mid collisions which might cause problems, demultiplexing the
218 wrong response to this request. Multiplex ids could collide if
219 one of a series requests takes much longer than the others, or
220 if a very large number of long lived requests (byte range
221 locks or FindNotify requests) are pending. No more than
222 64K-1 requests can be outstanding at one time. If no
223 mids are available, return zero. A future optimization
224 could make the combination of mids and uid the key we use
225 to demultiplex on (rather than mid alone).
226 In addition to the above check, the cifs demultiplex
227 code already used the command code as a secondary
228 check of the frame and if signing is negotiated the
229 response would be discarded if the mid were the same
230 but the signature was wrong. Since the mid is not put in the
231 pending queue until later (when it is about to be dispatched)
232 we do have to limit the number of outstanding requests
233 to somewhat less than 64K-1 although it is hard to imagine
234 so many threads being in the vfs at one time.
235*/
236__u16 GetNextMid(struct TCP_Server_Info *server)
237{
238 __u16 mid = 0;
239 __u16 last_mid;
240 bool collision;
241
242 spin_lock(&GlobalMid_Lock);
243 last_mid = server->CurrentMid; /* we do not want to loop forever */
244 server->CurrentMid++;
245 /* This nested loop looks more expensive than it is.
246 In practice the list of pending requests is short,
247 fewer than 50, and the mids are likely to be unique
248 on the first pass through the loop unless some request
249 takes longer than the 64 thousand requests before it
250 (and it would also have to have been a request that
251 did not time out) */
252 while (server->CurrentMid != last_mid) {
253 struct mid_q_entry *mid_entry;
254 unsigned int num_mids;
255
256 collision = false;
257 if (server->CurrentMid == 0)
258 server->CurrentMid++;
259
260 num_mids = 0;
261 list_for_each_entry(mid_entry, &server->pending_mid_q, qhead) {
262 ++num_mids;
263 if (mid_entry->mid == server->CurrentMid &&
264 mid_entry->midState == MID_REQUEST_SUBMITTED) {
265 /* This mid is in use, try a different one */
266 collision = true;
267 break;
268 }
269 }
270
271 /*
272 * if we have more than 32k mids in the list, then something
273 * is very wrong. Possibly a local user is trying to DoS the
274 * box by issuing long-running calls and SIGKILL'ing them. If
275 * we get to 2^16 mids then we're in big trouble as this
276 * function could loop forever.
277 *
278 * Go ahead and assign out the mid in this situation, but force
279 * an eventual reconnect to clean out the pending_mid_q.
280 */
281 if (num_mids > 32768)
282 server->tcpStatus = CifsNeedReconnect;
283
284 if (!collision) {
285 mid = server->CurrentMid;
286 break;
287 }
288 server->CurrentMid++;
289 }
290 spin_unlock(&GlobalMid_Lock);
291 return mid;
292}
293
294/* NB: MID can not be set if treeCon not passed in, in that
295 case it is responsbility of caller to set the mid */
296void
297header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
298 const struct cifs_tcon *treeCon, int word_count
299 /* length of fixed section (word count) in two byte units */)
300{
301 struct list_head *temp_item;
302 struct cifs_ses *ses;
303 char *temp = (char *) buffer;
304
305 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
306
307 buffer->smb_buf_length = cpu_to_be32(
308 (2 * word_count) + sizeof(struct smb_hdr) -
309 4 /* RFC 1001 length field does not count */ +
310 2 /* for bcc field itself */) ;
311
312 buffer->Protocol[0] = 0xFF;
313 buffer->Protocol[1] = 'S';
314 buffer->Protocol[2] = 'M';
315 buffer->Protocol[3] = 'B';
316 buffer->Command = smb_command;
317 buffer->Flags = 0x00; /* case sensitive */
318 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
319 buffer->Pid = cpu_to_le16((__u16)current->tgid);
320 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
321 if (treeCon) {
322 buffer->Tid = treeCon->tid;
323 if (treeCon->ses) {
324 if (treeCon->ses->capabilities & CAP_UNICODE)
325 buffer->Flags2 |= SMBFLG2_UNICODE;
326 if (treeCon->ses->capabilities & CAP_STATUS32)
327 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
328
329 /* Uid is not converted */
330 buffer->Uid = treeCon->ses->Suid;
331 buffer->Mid = GetNextMid(treeCon->ses->server);
332 if (multiuser_mount != 0) {
333 /* For the multiuser case, there are few obvious technically */
334 /* possible mechanisms to match the local linux user (uid) */
335 /* to a valid remote smb user (smb_uid): */
336 /* 1) Query Winbind (or other local pam/nss daemon */
337 /* for userid/password/logon_domain or credential */
338 /* 2) Query Winbind for uid to sid to username mapping */
339 /* and see if we have a matching password for existing*/
340 /* session for that user perhas getting password by */
341 /* adding a new pam_cifs module that stores passwords */
342 /* so that the cifs vfs can get at that for all logged*/
343 /* on users */
344 /* 3) (Which is the mechanism we have chosen) */
345 /* Search through sessions to the same server for a */
346 /* a match on the uid that was passed in on mount */
347 /* with the current processes uid (or euid?) and use */
348 /* that smb uid. If no existing smb session for */
349 /* that uid found, use the default smb session ie */
350 /* the smb session for the volume mounted which is */
351 /* the same as would be used if the multiuser mount */
352 /* flag were disabled. */
353
354 /* BB Add support for establishing new tCon and SMB Session */
355 /* with userid/password pairs found on the smb session */
356 /* for other target tcp/ip addresses BB */
357 if (current_fsuid() != treeCon->ses->linux_uid) {
358 cFYI(1, "Multiuser mode and UID "
359 "did not match tcon uid");
360 spin_lock(&cifs_tcp_ses_lock);
361 list_for_each(temp_item, &treeCon->ses->server->smb_ses_list) {
362 ses = list_entry(temp_item, struct cifs_ses, smb_ses_list);
363 if (ses->linux_uid == current_fsuid()) {
364 if (ses->server == treeCon->ses->server) {
365 cFYI(1, "found matching uid substitute right smb_uid");
366 buffer->Uid = ses->Suid;
367 break;
368 } else {
369 /* BB eventually call cifs_setup_session here */
370 cFYI(1, "local UID found but no smb sess with this server exists");
371 }
372 }
373 }
374 spin_unlock(&cifs_tcp_ses_lock);
375 }
376 }
377 }
378 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
379 buffer->Flags2 |= SMBFLG2_DFS;
380 if (treeCon->nocase)
381 buffer->Flags |= SMBFLG_CASELESS;
382 if ((treeCon->ses) && (treeCon->ses->server))
383 if (treeCon->ses->server->sec_mode &
384 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
385 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
386 }
387
388/* endian conversion of flags is now done just before sending */
389 buffer->WordCount = (char) word_count;
390 return;
391}
392
393static int
394check_smb_hdr(struct smb_hdr *smb, __u16 mid)
395{
396 /* does it have the right SMB "signature" ? */
397 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
398 cERROR(1, "Bad protocol string signature header 0x%x",
399 *(unsigned int *)smb->Protocol);
400 return 1;
401 }
402
403 /* Make sure that message ids match */
404 if (mid != smb->Mid) {
405 cERROR(1, "Mids do not match. received=%u expected=%u",
406 smb->Mid, mid);
407 return 1;
408 }
409
410 /* if it's a response then accept */
411 if (smb->Flags & SMBFLG_RESPONSE)
412 return 0;
413
414 /* only one valid case where server sends us request */
415 if (smb->Command == SMB_COM_LOCKING_ANDX)
416 return 0;
417
418 cERROR(1, "Server sent request, not response. mid=%u", smb->Mid);
419 return 1;
420}
421
422int
423checkSMB(struct smb_hdr *smb, __u16 mid, unsigned int length)
424{
425 __u32 len = be32_to_cpu(smb->smb_buf_length);
426 __u32 clc_len; /* calculated length */
427 cFYI(0, "checkSMB Length: 0x%x, smb_buf_length: 0x%x", length, len);
428
429 if (length < 2 + sizeof(struct smb_hdr)) {
430 if ((length >= sizeof(struct smb_hdr) - 1)
431 && (smb->Status.CifsError != 0)) {
432 smb->WordCount = 0;
433 /* some error cases do not return wct and bcc */
434 return 0;
435 } else if ((length == sizeof(struct smb_hdr) + 1) &&
436 (smb->WordCount == 0)) {
437 char *tmp = (char *)smb;
438 /* Need to work around a bug in two servers here */
439 /* First, check if the part of bcc they sent was zero */
440 if (tmp[sizeof(struct smb_hdr)] == 0) {
441 /* some servers return only half of bcc
442 * on simple responses (wct, bcc both zero)
443 * in particular have seen this on
444 * ulogoffX and FindClose. This leaves
445 * one byte of bcc potentially unitialized
446 */
447 /* zero rest of bcc */
448 tmp[sizeof(struct smb_hdr)+1] = 0;
449 return 0;
450 }
451 cERROR(1, "rcvd invalid byte count (bcc)");
452 } else {
453 cERROR(1, "Length less than smb header size");
454 }
455 return 1;
456 }
457 if (len > CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4) {
458 cERROR(1, "smb length greater than MaxBufSize, mid=%d",
459 smb->Mid);
460 return 1;
461 }
462
463 if (check_smb_hdr(smb, mid))
464 return 1;
465 clc_len = smbCalcSize(smb);
466
467 if (4 + len != length) {
468 cERROR(1, "Length read does not match RFC1001 length %d",
469 len);
470 return 1;
471 }
472
473 if (4 + len != clc_len) {
474 /* check if bcc wrapped around for large read responses */
475 if ((len > 64 * 1024) && (len > clc_len)) {
476 /* check if lengths match mod 64K */
477 if (((4 + len) & 0xFFFF) == (clc_len & 0xFFFF))
478 return 0; /* bcc wrapped */
479 }
480 cFYI(1, "Calculated size %u vs length %u mismatch for mid=%u",
481 clc_len, 4 + len, smb->Mid);
482
483 if (4 + len < clc_len) {
484 cERROR(1, "RFC1001 size %u smaller than SMB for mid=%u",
485 len, smb->Mid);
486 return 1;
487 } else if (len > clc_len + 512) {
488 /*
489 * Some servers (Windows XP in particular) send more
490 * data than the lengths in the SMB packet would
491 * indicate on certain calls (byte range locks and
492 * trans2 find first calls in particular). While the
493 * client can handle such a frame by ignoring the
494 * trailing data, we choose limit the amount of extra
495 * data to 512 bytes.
496 */
497 cERROR(1, "RFC1001 size %u more than 512 bytes larger "
498 "than SMB for mid=%u", len, smb->Mid);
499 return 1;
500 }
501 }
502 return 0;
503}
504
505bool
506is_valid_oplock_break(struct smb_hdr *buf, struct TCP_Server_Info *srv)
507{
508 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
509 struct list_head *tmp, *tmp1, *tmp2;
510 struct cifs_ses *ses;
511 struct cifs_tcon *tcon;
512 struct cifsInodeInfo *pCifsInode;
513 struct cifsFileInfo *netfile;
514
515 cFYI(1, "Checking for oplock break or dnotify response");
516 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
517 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
518 struct smb_com_transaction_change_notify_rsp *pSMBr =
519 (struct smb_com_transaction_change_notify_rsp *)buf;
520 struct file_notify_information *pnotify;
521 __u32 data_offset = 0;
522 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
523 data_offset = le32_to_cpu(pSMBr->DataOffset);
524
525 pnotify = (struct file_notify_information *)
526 ((char *)&pSMBr->hdr.Protocol + data_offset);
527 cFYI(1, "dnotify on %s Action: 0x%x",
528 pnotify->FileName, pnotify->Action);
529 /* cifs_dump_mem("Rcvd notify Data: ",buf,
530 sizeof(struct smb_hdr)+60); */
531 return true;
532 }
533 if (pSMBr->hdr.Status.CifsError) {
534 cFYI(1, "notify err 0x%d",
535 pSMBr->hdr.Status.CifsError);
536 return true;
537 }
538 return false;
539 }
540 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
541 return false;
542 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
543 /* no sense logging error on invalid handle on oplock
544 break - harmless race between close request and oplock
545 break response is expected from time to time writing out
546 large dirty files cached on the client */
547 if ((NT_STATUS_INVALID_HANDLE) ==
548 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
549 cFYI(1, "invalid handle on oplock break");
550 return true;
551 } else if (ERRbadfid ==
552 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
553 return true;
554 } else {
555 return false; /* on valid oplock brk we get "request" */
556 }
557 }
558 if (pSMB->hdr.WordCount != 8)
559 return false;
560
561 cFYI(1, "oplock type 0x%d level 0x%d",
562 pSMB->LockType, pSMB->OplockLevel);
563 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
564 return false;
565
566 /* look up tcon based on tid & uid */
567 spin_lock(&cifs_tcp_ses_lock);
568 list_for_each(tmp, &srv->smb_ses_list) {
569 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
570 list_for_each(tmp1, &ses->tcon_list) {
571 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
572 if (tcon->tid != buf->Tid)
573 continue;
574
575 cifs_stats_inc(&tcon->num_oplock_brks);
576 spin_lock(&cifs_file_list_lock);
577 list_for_each(tmp2, &tcon->openFileList) {
578 netfile = list_entry(tmp2, struct cifsFileInfo,
579 tlist);
580 if (pSMB->Fid != netfile->netfid)
581 continue;
582
583 cFYI(1, "file id match, oplock break");
584 pCifsInode = CIFS_I(netfile->dentry->d_inode);
585
586 cifs_set_oplock_level(pCifsInode,
587 pSMB->OplockLevel ? OPLOCK_READ : 0);
588 queue_work(system_nrt_wq,
589 &netfile->oplock_break);
590 netfile->oplock_break_cancelled = false;
591
592 spin_unlock(&cifs_file_list_lock);
593 spin_unlock(&cifs_tcp_ses_lock);
594 return true;
595 }
596 spin_unlock(&cifs_file_list_lock);
597 spin_unlock(&cifs_tcp_ses_lock);
598 cFYI(1, "No matching file for oplock break");
599 return true;
600 }
601 }
602 spin_unlock(&cifs_tcp_ses_lock);
603 cFYI(1, "Can not process oplock break for non-existent connection");
604 return true;
605}
606
607void
608dump_smb(struct smb_hdr *smb_buf, int smb_buf_length)
609{
610 int i, j;
611 char debug_line[17];
612 unsigned char *buffer;
613
614 if (traceSMB == 0)
615 return;
616
617 buffer = (unsigned char *) smb_buf;
618 for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
619 if (i % 8 == 0) {
620 /* have reached the beginning of line */
621 printk(KERN_DEBUG "| ");
622 j = 0;
623 }
624 printk("%0#4x ", buffer[i]);
625 debug_line[2 * j] = ' ';
626 if (isprint(buffer[i]))
627 debug_line[1 + (2 * j)] = buffer[i];
628 else
629 debug_line[1 + (2 * j)] = '_';
630
631 if (i % 8 == 7) {
632 /* reached end of line, time to print ascii */
633 debug_line[16] = 0;
634 printk(" | %s\n", debug_line);
635 }
636 }
637 for (; j < 8; j++) {
638 printk(" ");
639 debug_line[2 * j] = ' ';
640 debug_line[1 + (2 * j)] = ' ';
641 }
642 printk(" | %s\n", debug_line);
643 return;
644}
645
646void
647cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
648{
649 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
650 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
651 cERROR(1, "Autodisabling the use of server inode numbers on "
652 "%s. This server doesn't seem to support them "
653 "properly. Hardlinks will not be recognized on this "
654 "mount. Consider mounting with the \"noserverino\" "
655 "option to silence this message.",
656 cifs_sb_master_tcon(cifs_sb)->treeName);
657 }
658}
659
660void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
661{
662 oplock &= 0xF;
663
664 if (oplock == OPLOCK_EXCLUSIVE) {
665 cinode->clientCanCacheAll = true;
666 cinode->clientCanCacheRead = true;
667 cFYI(1, "Exclusive Oplock granted on inode %p",
668 &cinode->vfs_inode);
669 } else if (oplock == OPLOCK_READ) {
670 cinode->clientCanCacheAll = false;
671 cinode->clientCanCacheRead = true;
672 cFYI(1, "Level II Oplock granted on inode %p",
673 &cinode->vfs_inode);
674 } else {
675 cinode->clientCanCacheAll = false;
676 cinode->clientCanCacheRead = false;
677 }
678}
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 "cifspdu.h"
26#include "cifsglob.h"
27#include "cifsproto.h"
28#include "cifs_debug.h"
29#include "smberr.h"
30#include "nterr.h"
31#include "cifs_unicode.h"
32
33extern mempool_t *cifs_sm_req_poolp;
34extern mempool_t *cifs_req_poolp;
35
36/* The xid serves as a useful identifier for each incoming vfs request,
37 in a similar way to the mid which is useful to track each sent smb,
38 and CurrentXid can also provide a running counter (although it
39 will eventually wrap past zero) of the total vfs operations handled
40 since the cifs fs was mounted */
41
42unsigned int
43_GetXid(void)
44{
45 unsigned int xid;
46
47 spin_lock(&GlobalMid_Lock);
48 GlobalTotalActiveXid++;
49
50 /* keep high water mark for number of simultaneous ops in filesystem */
51 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
52 GlobalMaxActiveXid = GlobalTotalActiveXid;
53 if (GlobalTotalActiveXid > 65000)
54 cFYI(1, "warning: more than 65000 requests active");
55 xid = GlobalCurrentXid++;
56 spin_unlock(&GlobalMid_Lock);
57 return xid;
58}
59
60void
61_FreeXid(unsigned int xid)
62{
63 spin_lock(&GlobalMid_Lock);
64 /* if (GlobalTotalActiveXid == 0)
65 BUG(); */
66 GlobalTotalActiveXid--;
67 spin_unlock(&GlobalMid_Lock);
68}
69
70struct cifs_ses *
71sesInfoAlloc(void)
72{
73 struct cifs_ses *ret_buf;
74
75 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
76 if (ret_buf) {
77 atomic_inc(&sesInfoAllocCount);
78 ret_buf->status = CifsNew;
79 ++ret_buf->ses_count;
80 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
81 INIT_LIST_HEAD(&ret_buf->tcon_list);
82 mutex_init(&ret_buf->session_mutex);
83 }
84 return ret_buf;
85}
86
87void
88sesInfoFree(struct cifs_ses *buf_to_free)
89{
90 if (buf_to_free == NULL) {
91 cFYI(1, "Null buffer passed to sesInfoFree");
92 return;
93 }
94
95 atomic_dec(&sesInfoAllocCount);
96 kfree(buf_to_free->serverOS);
97 kfree(buf_to_free->serverDomain);
98 kfree(buf_to_free->serverNOS);
99 if (buf_to_free->password) {
100 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
101 kfree(buf_to_free->password);
102 }
103 kfree(buf_to_free->user_name);
104 kfree(buf_to_free->domainName);
105 kfree(buf_to_free);
106}
107
108struct cifs_tcon *
109tconInfoAlloc(void)
110{
111 struct cifs_tcon *ret_buf;
112 ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
113 if (ret_buf) {
114 atomic_inc(&tconInfoAllocCount);
115 ret_buf->tidStatus = CifsNew;
116 ++ret_buf->tc_count;
117 INIT_LIST_HEAD(&ret_buf->openFileList);
118 INIT_LIST_HEAD(&ret_buf->tcon_list);
119#ifdef CONFIG_CIFS_STATS
120 spin_lock_init(&ret_buf->stat_lock);
121#endif
122 }
123 return ret_buf;
124}
125
126void
127tconInfoFree(struct cifs_tcon *buf_to_free)
128{
129 if (buf_to_free == NULL) {
130 cFYI(1, "Null buffer passed to tconInfoFree");
131 return;
132 }
133 atomic_dec(&tconInfoAllocCount);
134 kfree(buf_to_free->nativeFileSystem);
135 if (buf_to_free->password) {
136 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
137 kfree(buf_to_free->password);
138 }
139 kfree(buf_to_free);
140}
141
142struct smb_hdr *
143cifs_buf_get(void)
144{
145 struct smb_hdr *ret_buf = NULL;
146
147/* We could use negotiated size instead of max_msgsize -
148 but it may be more efficient to always alloc same size
149 albeit slightly larger than necessary and maxbuffersize
150 defaults to this and can not be bigger */
151 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
152
153 /* clear the first few header bytes */
154 /* for most paths, more is cleared in header_assemble */
155 if (ret_buf) {
156 memset(ret_buf, 0, sizeof(struct smb_hdr) + 3);
157 atomic_inc(&bufAllocCount);
158#ifdef CONFIG_CIFS_STATS2
159 atomic_inc(&totBufAllocCount);
160#endif /* CONFIG_CIFS_STATS2 */
161 }
162
163 return ret_buf;
164}
165
166void
167cifs_buf_release(void *buf_to_free)
168{
169 if (buf_to_free == NULL) {
170 /* cFYI(1, "Null buffer passed to cifs_buf_release");*/
171 return;
172 }
173 mempool_free(buf_to_free, cifs_req_poolp);
174
175 atomic_dec(&bufAllocCount);
176 return;
177}
178
179struct smb_hdr *
180cifs_small_buf_get(void)
181{
182 struct smb_hdr *ret_buf = NULL;
183
184/* We could use negotiated size instead of max_msgsize -
185 but it may be more efficient to always alloc same size
186 albeit slightly larger than necessary and maxbuffersize
187 defaults to this and can not be bigger */
188 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
189 if (ret_buf) {
190 /* No need to clear memory here, cleared in header assemble */
191 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
192 atomic_inc(&smBufAllocCount);
193#ifdef CONFIG_CIFS_STATS2
194 atomic_inc(&totSmBufAllocCount);
195#endif /* CONFIG_CIFS_STATS2 */
196
197 }
198 return ret_buf;
199}
200
201void
202cifs_small_buf_release(void *buf_to_free)
203{
204
205 if (buf_to_free == NULL) {
206 cFYI(1, "Null buffer passed to cifs_small_buf_release");
207 return;
208 }
209 mempool_free(buf_to_free, cifs_sm_req_poolp);
210
211 atomic_dec(&smBufAllocCount);
212 return;
213}
214
215/* NB: MID can not be set if treeCon not passed in, in that
216 case it is responsbility of caller to set the mid */
217void
218header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
219 const struct cifs_tcon *treeCon, int word_count
220 /* length of fixed section (word count) in two byte units */)
221{
222 char *temp = (char *) buffer;
223
224 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
225
226 buffer->smb_buf_length = cpu_to_be32(
227 (2 * word_count) + sizeof(struct smb_hdr) -
228 4 /* RFC 1001 length field does not count */ +
229 2 /* for bcc field itself */) ;
230
231 buffer->Protocol[0] = 0xFF;
232 buffer->Protocol[1] = 'S';
233 buffer->Protocol[2] = 'M';
234 buffer->Protocol[3] = 'B';
235 buffer->Command = smb_command;
236 buffer->Flags = 0x00; /* case sensitive */
237 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
238 buffer->Pid = cpu_to_le16((__u16)current->tgid);
239 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
240 if (treeCon) {
241 buffer->Tid = treeCon->tid;
242 if (treeCon->ses) {
243 if (treeCon->ses->capabilities & CAP_UNICODE)
244 buffer->Flags2 |= SMBFLG2_UNICODE;
245 if (treeCon->ses->capabilities & CAP_STATUS32)
246 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
247
248 /* Uid is not converted */
249 buffer->Uid = treeCon->ses->Suid;
250 buffer->Mid = get_next_mid(treeCon->ses->server);
251 }
252 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
253 buffer->Flags2 |= SMBFLG2_DFS;
254 if (treeCon->nocase)
255 buffer->Flags |= SMBFLG_CASELESS;
256 if ((treeCon->ses) && (treeCon->ses->server))
257 if (treeCon->ses->server->sec_mode &
258 (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
259 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
260 }
261
262/* endian conversion of flags is now done just before sending */
263 buffer->WordCount = (char) word_count;
264 return;
265}
266
267static int
268check_smb_hdr(struct smb_hdr *smb, __u16 mid)
269{
270 /* does it have the right SMB "signature" ? */
271 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
272 cERROR(1, "Bad protocol string signature header 0x%x",
273 *(unsigned int *)smb->Protocol);
274 return 1;
275 }
276
277 /* Make sure that message ids match */
278 if (mid != smb->Mid) {
279 cERROR(1, "Mids do not match. received=%u expected=%u",
280 smb->Mid, mid);
281 return 1;
282 }
283
284 /* if it's a response then accept */
285 if (smb->Flags & SMBFLG_RESPONSE)
286 return 0;
287
288 /* only one valid case where server sends us request */
289 if (smb->Command == SMB_COM_LOCKING_ANDX)
290 return 0;
291
292 cERROR(1, "Server sent request, not response. mid=%u", smb->Mid);
293 return 1;
294}
295
296int
297checkSMB(char *buf, unsigned int total_read)
298{
299 struct smb_hdr *smb = (struct smb_hdr *)buf;
300 __u16 mid = smb->Mid;
301 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
302 __u32 clc_len; /* calculated length */
303 cFYI(0, "checkSMB Length: 0x%x, smb_buf_length: 0x%x",
304 total_read, rfclen);
305
306 /* is this frame too small to even get to a BCC? */
307 if (total_read < 2 + sizeof(struct smb_hdr)) {
308 if ((total_read >= sizeof(struct smb_hdr) - 1)
309 && (smb->Status.CifsError != 0)) {
310 /* it's an error return */
311 smb->WordCount = 0;
312 /* some error cases do not return wct and bcc */
313 return 0;
314 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
315 (smb->WordCount == 0)) {
316 char *tmp = (char *)smb;
317 /* Need to work around a bug in two servers here */
318 /* First, check if the part of bcc they sent was zero */
319 if (tmp[sizeof(struct smb_hdr)] == 0) {
320 /* some servers return only half of bcc
321 * on simple responses (wct, bcc both zero)
322 * in particular have seen this on
323 * ulogoffX and FindClose. This leaves
324 * one byte of bcc potentially unitialized
325 */
326 /* zero rest of bcc */
327 tmp[sizeof(struct smb_hdr)+1] = 0;
328 return 0;
329 }
330 cERROR(1, "rcvd invalid byte count (bcc)");
331 } else {
332 cERROR(1, "Length less than smb header size");
333 }
334 return -EIO;
335 }
336
337 /* otherwise, there is enough to get to the BCC */
338 if (check_smb_hdr(smb, mid))
339 return -EIO;
340 clc_len = smbCalcSize(smb);
341
342 if (4 + rfclen != total_read) {
343 cERROR(1, "Length read does not match RFC1001 length %d",
344 rfclen);
345 return -EIO;
346 }
347
348 if (4 + rfclen != clc_len) {
349 /* check if bcc wrapped around for large read responses */
350 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
351 /* check if lengths match mod 64K */
352 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
353 return 0; /* bcc wrapped */
354 }
355 cFYI(1, "Calculated size %u vs length %u mismatch for mid=%u",
356 clc_len, 4 + rfclen, smb->Mid);
357
358 if (4 + rfclen < clc_len) {
359 cERROR(1, "RFC1001 size %u smaller than SMB for mid=%u",
360 rfclen, smb->Mid);
361 return -EIO;
362 } else if (rfclen > clc_len + 512) {
363 /*
364 * Some servers (Windows XP in particular) send more
365 * data than the lengths in the SMB packet would
366 * indicate on certain calls (byte range locks and
367 * trans2 find first calls in particular). While the
368 * client can handle such a frame by ignoring the
369 * trailing data, we choose limit the amount of extra
370 * data to 512 bytes.
371 */
372 cERROR(1, "RFC1001 size %u more than 512 bytes larger "
373 "than SMB for mid=%u", rfclen, smb->Mid);
374 return -EIO;
375 }
376 }
377 return 0;
378}
379
380bool
381is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
382{
383 struct smb_hdr *buf = (struct smb_hdr *)buffer;
384 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
385 struct list_head *tmp, *tmp1, *tmp2;
386 struct cifs_ses *ses;
387 struct cifs_tcon *tcon;
388 struct cifsInodeInfo *pCifsInode;
389 struct cifsFileInfo *netfile;
390
391 cFYI(1, "Checking for oplock break or dnotify response");
392 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
393 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
394 struct smb_com_transaction_change_notify_rsp *pSMBr =
395 (struct smb_com_transaction_change_notify_rsp *)buf;
396 struct file_notify_information *pnotify;
397 __u32 data_offset = 0;
398 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
399 data_offset = le32_to_cpu(pSMBr->DataOffset);
400
401 pnotify = (struct file_notify_information *)
402 ((char *)&pSMBr->hdr.Protocol + data_offset);
403 cFYI(1, "dnotify on %s Action: 0x%x",
404 pnotify->FileName, pnotify->Action);
405 /* cifs_dump_mem("Rcvd notify Data: ",buf,
406 sizeof(struct smb_hdr)+60); */
407 return true;
408 }
409 if (pSMBr->hdr.Status.CifsError) {
410 cFYI(1, "notify err 0x%d",
411 pSMBr->hdr.Status.CifsError);
412 return true;
413 }
414 return false;
415 }
416 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
417 return false;
418 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
419 /* no sense logging error on invalid handle on oplock
420 break - harmless race between close request and oplock
421 break response is expected from time to time writing out
422 large dirty files cached on the client */
423 if ((NT_STATUS_INVALID_HANDLE) ==
424 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
425 cFYI(1, "invalid handle on oplock break");
426 return true;
427 } else if (ERRbadfid ==
428 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
429 return true;
430 } else {
431 return false; /* on valid oplock brk we get "request" */
432 }
433 }
434 if (pSMB->hdr.WordCount != 8)
435 return false;
436
437 cFYI(1, "oplock type 0x%d level 0x%d",
438 pSMB->LockType, pSMB->OplockLevel);
439 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
440 return false;
441
442 /* look up tcon based on tid & uid */
443 spin_lock(&cifs_tcp_ses_lock);
444 list_for_each(tmp, &srv->smb_ses_list) {
445 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
446 list_for_each(tmp1, &ses->tcon_list) {
447 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
448 if (tcon->tid != buf->Tid)
449 continue;
450
451 cifs_stats_inc(&tcon->num_oplock_brks);
452 spin_lock(&cifs_file_list_lock);
453 list_for_each(tmp2, &tcon->openFileList) {
454 netfile = list_entry(tmp2, struct cifsFileInfo,
455 tlist);
456 if (pSMB->Fid != netfile->netfid)
457 continue;
458
459 cFYI(1, "file id match, oplock break");
460 pCifsInode = CIFS_I(netfile->dentry->d_inode);
461
462 cifs_set_oplock_level(pCifsInode,
463 pSMB->OplockLevel ? OPLOCK_READ : 0);
464 queue_work(cifsiod_wq,
465 &netfile->oplock_break);
466 netfile->oplock_break_cancelled = false;
467
468 spin_unlock(&cifs_file_list_lock);
469 spin_unlock(&cifs_tcp_ses_lock);
470 return true;
471 }
472 spin_unlock(&cifs_file_list_lock);
473 spin_unlock(&cifs_tcp_ses_lock);
474 cFYI(1, "No matching file for oplock break");
475 return true;
476 }
477 }
478 spin_unlock(&cifs_tcp_ses_lock);
479 cFYI(1, "Can not process oplock break for non-existent connection");
480 return true;
481}
482
483void
484dump_smb(void *buf, int smb_buf_length)
485{
486 int i, j;
487 char debug_line[17];
488 unsigned char *buffer = buf;
489
490 if (traceSMB == 0)
491 return;
492
493 for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
494 if (i % 8 == 0) {
495 /* have reached the beginning of line */
496 printk(KERN_DEBUG "| ");
497 j = 0;
498 }
499 printk("%0#4x ", buffer[i]);
500 debug_line[2 * j] = ' ';
501 if (isprint(buffer[i]))
502 debug_line[1 + (2 * j)] = buffer[i];
503 else
504 debug_line[1 + (2 * j)] = '_';
505
506 if (i % 8 == 7) {
507 /* reached end of line, time to print ascii */
508 debug_line[16] = 0;
509 printk(" | %s\n", debug_line);
510 }
511 }
512 for (; j < 8; j++) {
513 printk(" ");
514 debug_line[2 * j] = ' ';
515 debug_line[1 + (2 * j)] = ' ';
516 }
517 printk(" | %s\n", debug_line);
518 return;
519}
520
521void
522cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
523{
524 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
525 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
526 cERROR(1, "Autodisabling the use of server inode numbers on "
527 "%s. This server doesn't seem to support them "
528 "properly. Hardlinks will not be recognized on this "
529 "mount. Consider mounting with the \"noserverino\" "
530 "option to silence this message.",
531 cifs_sb_master_tcon(cifs_sb)->treeName);
532 }
533}
534
535void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
536{
537 oplock &= 0xF;
538
539 if (oplock == OPLOCK_EXCLUSIVE) {
540 cinode->clientCanCacheAll = true;
541 cinode->clientCanCacheRead = true;
542 cFYI(1, "Exclusive Oplock granted on inode %p",
543 &cinode->vfs_inode);
544 } else if (oplock == OPLOCK_READ) {
545 cinode->clientCanCacheAll = false;
546 cinode->clientCanCacheRead = true;
547 cFYI(1, "Level II Oplock granted on inode %p",
548 &cinode->vfs_inode);
549 } else {
550 cinode->clientCanCacheAll = false;
551 cinode->clientCanCacheRead = false;
552 }
553}
554
555bool
556backup_cred(struct cifs_sb_info *cifs_sb)
557{
558 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
559 if (cifs_sb->mnt_backupuid == current_fsuid())
560 return true;
561 }
562 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
563 if (in_group_p(cifs_sb->mnt_backupgid))
564 return true;
565 }
566
567 return false;
568}