Linux 4.3
[linux/fpc-iii.git] / fs / cifs / misc.c
blob8442b8b8e0be145e7f68055e0025f1909442d156
1 /*
2 * fs/cifs/misc.c
4 * Copyright (C) International Business Machines Corp., 2002,2008
5 * Author(s): Steve French (sfrench@us.ibm.com)
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.
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.
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
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 #ifdef CONFIG_CIFS_SMB2
33 #include "smb2pdu.h"
34 #endif
36 extern mempool_t *cifs_sm_req_poolp;
37 extern mempool_t *cifs_req_poolp;
39 /* The xid serves as a useful identifier for each incoming vfs request,
40 in a similar way to the mid which is useful to track each sent smb,
41 and CurrentXid can also provide a running counter (although it
42 will eventually wrap past zero) of the total vfs operations handled
43 since the cifs fs was mounted */
45 unsigned int
46 _get_xid(void)
48 unsigned int xid;
50 spin_lock(&GlobalMid_Lock);
51 GlobalTotalActiveXid++;
53 /* keep high water mark for number of simultaneous ops in filesystem */
54 if (GlobalTotalActiveXid > GlobalMaxActiveXid)
55 GlobalMaxActiveXid = GlobalTotalActiveXid;
56 if (GlobalTotalActiveXid > 65000)
57 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
58 xid = GlobalCurrentXid++;
59 spin_unlock(&GlobalMid_Lock);
60 return xid;
63 void
64 _free_xid(unsigned int xid)
66 spin_lock(&GlobalMid_Lock);
67 /* if (GlobalTotalActiveXid == 0)
68 BUG(); */
69 GlobalTotalActiveXid--;
70 spin_unlock(&GlobalMid_Lock);
73 struct cifs_ses *
74 sesInfoAlloc(void)
76 struct cifs_ses *ret_buf;
78 ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
79 if (ret_buf) {
80 atomic_inc(&sesInfoAllocCount);
81 ret_buf->status = CifsNew;
82 ++ret_buf->ses_count;
83 INIT_LIST_HEAD(&ret_buf->smb_ses_list);
84 INIT_LIST_HEAD(&ret_buf->tcon_list);
85 mutex_init(&ret_buf->session_mutex);
87 return ret_buf;
90 void
91 sesInfoFree(struct cifs_ses *buf_to_free)
93 if (buf_to_free == NULL) {
94 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
95 return;
98 atomic_dec(&sesInfoAllocCount);
99 kfree(buf_to_free->serverOS);
100 kfree(buf_to_free->serverDomain);
101 kfree(buf_to_free->serverNOS);
102 if (buf_to_free->password) {
103 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
104 kfree(buf_to_free->password);
106 kfree(buf_to_free->user_name);
107 kfree(buf_to_free->domainName);
108 kfree(buf_to_free->auth_key.response);
109 kfree(buf_to_free);
112 struct cifs_tcon *
113 tconInfoAlloc(void)
115 struct cifs_tcon *ret_buf;
116 ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
117 if (ret_buf) {
118 atomic_inc(&tconInfoAllocCount);
119 ret_buf->tidStatus = CifsNew;
120 ++ret_buf->tc_count;
121 INIT_LIST_HEAD(&ret_buf->openFileList);
122 INIT_LIST_HEAD(&ret_buf->tcon_list);
123 #ifdef CONFIG_CIFS_STATS
124 spin_lock_init(&ret_buf->stat_lock);
125 #endif
127 return ret_buf;
130 void
131 tconInfoFree(struct cifs_tcon *buf_to_free)
133 if (buf_to_free == NULL) {
134 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
135 return;
137 atomic_dec(&tconInfoAllocCount);
138 kfree(buf_to_free->nativeFileSystem);
139 if (buf_to_free->password) {
140 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
141 kfree(buf_to_free->password);
143 kfree(buf_to_free);
146 struct smb_hdr *
147 cifs_buf_get(void)
149 struct smb_hdr *ret_buf = NULL;
150 size_t buf_size = sizeof(struct smb_hdr);
152 #ifdef CONFIG_CIFS_SMB2
154 * SMB2 header is bigger than CIFS one - no problems to clean some
155 * more bytes for CIFS.
157 buf_size = sizeof(struct smb2_hdr);
158 #endif
160 * We could use negotiated size instead of max_msgsize -
161 * but it may be more efficient to always alloc same size
162 * albeit slightly larger than necessary and maxbuffersize
163 * defaults to this and can not be bigger.
165 ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
167 /* clear the first few header bytes */
168 /* for most paths, more is cleared in header_assemble */
169 if (ret_buf) {
170 memset(ret_buf, 0, buf_size + 3);
171 atomic_inc(&bufAllocCount);
172 #ifdef CONFIG_CIFS_STATS2
173 atomic_inc(&totBufAllocCount);
174 #endif /* CONFIG_CIFS_STATS2 */
177 return ret_buf;
180 void
181 cifs_buf_release(void *buf_to_free)
183 if (buf_to_free == NULL) {
184 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
185 return;
187 mempool_free(buf_to_free, cifs_req_poolp);
189 atomic_dec(&bufAllocCount);
190 return;
193 struct smb_hdr *
194 cifs_small_buf_get(void)
196 struct smb_hdr *ret_buf = NULL;
198 /* We could use negotiated size instead of max_msgsize -
199 but it may be more efficient to always alloc same size
200 albeit slightly larger than necessary and maxbuffersize
201 defaults to this and can not be bigger */
202 ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
203 if (ret_buf) {
204 /* No need to clear memory here, cleared in header assemble */
205 /* memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
206 atomic_inc(&smBufAllocCount);
207 #ifdef CONFIG_CIFS_STATS2
208 atomic_inc(&totSmBufAllocCount);
209 #endif /* CONFIG_CIFS_STATS2 */
212 return ret_buf;
215 void
216 cifs_small_buf_release(void *buf_to_free)
219 if (buf_to_free == NULL) {
220 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
221 return;
223 mempool_free(buf_to_free, cifs_sm_req_poolp);
225 atomic_dec(&smBufAllocCount);
226 return;
229 void
230 free_rsp_buf(int resp_buftype, void *rsp)
232 if (resp_buftype == CIFS_SMALL_BUFFER)
233 cifs_small_buf_release(rsp);
234 else if (resp_buftype == CIFS_LARGE_BUFFER)
235 cifs_buf_release(rsp);
238 /* NB: MID can not be set if treeCon not passed in, in that
239 case it is responsbility of caller to set the mid */
240 void
241 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
242 const struct cifs_tcon *treeCon, int word_count
243 /* length of fixed section (word count) in two byte units */)
245 char *temp = (char *) buffer;
247 memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
249 buffer->smb_buf_length = cpu_to_be32(
250 (2 * word_count) + sizeof(struct smb_hdr) -
251 4 /* RFC 1001 length field does not count */ +
252 2 /* for bcc field itself */) ;
254 buffer->Protocol[0] = 0xFF;
255 buffer->Protocol[1] = 'S';
256 buffer->Protocol[2] = 'M';
257 buffer->Protocol[3] = 'B';
258 buffer->Command = smb_command;
259 buffer->Flags = 0x00; /* case sensitive */
260 buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
261 buffer->Pid = cpu_to_le16((__u16)current->tgid);
262 buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
263 if (treeCon) {
264 buffer->Tid = treeCon->tid;
265 if (treeCon->ses) {
266 if (treeCon->ses->capabilities & CAP_UNICODE)
267 buffer->Flags2 |= SMBFLG2_UNICODE;
268 if (treeCon->ses->capabilities & CAP_STATUS32)
269 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
271 /* Uid is not converted */
272 buffer->Uid = treeCon->ses->Suid;
273 buffer->Mid = get_next_mid(treeCon->ses->server);
275 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
276 buffer->Flags2 |= SMBFLG2_DFS;
277 if (treeCon->nocase)
278 buffer->Flags |= SMBFLG_CASELESS;
279 if ((treeCon->ses) && (treeCon->ses->server))
280 if (treeCon->ses->server->sign)
281 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
284 /* endian conversion of flags is now done just before sending */
285 buffer->WordCount = (char) word_count;
286 return;
289 static int
290 check_smb_hdr(struct smb_hdr *smb)
292 /* does it have the right SMB "signature" ? */
293 if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
294 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
295 *(unsigned int *)smb->Protocol);
296 return 1;
299 /* if it's a response then accept */
300 if (smb->Flags & SMBFLG_RESPONSE)
301 return 0;
303 /* only one valid case where server sends us request */
304 if (smb->Command == SMB_COM_LOCKING_ANDX)
305 return 0;
307 cifs_dbg(VFS, "Server sent request, not response. mid=%u\n",
308 get_mid(smb));
309 return 1;
313 checkSMB(char *buf, unsigned int total_read)
315 struct smb_hdr *smb = (struct smb_hdr *)buf;
316 __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
317 __u32 clc_len; /* calculated length */
318 cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
319 total_read, rfclen);
321 /* is this frame too small to even get to a BCC? */
322 if (total_read < 2 + sizeof(struct smb_hdr)) {
323 if ((total_read >= sizeof(struct smb_hdr) - 1)
324 && (smb->Status.CifsError != 0)) {
325 /* it's an error return */
326 smb->WordCount = 0;
327 /* some error cases do not return wct and bcc */
328 return 0;
329 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
330 (smb->WordCount == 0)) {
331 char *tmp = (char *)smb;
332 /* Need to work around a bug in two servers here */
333 /* First, check if the part of bcc they sent was zero */
334 if (tmp[sizeof(struct smb_hdr)] == 0) {
335 /* some servers return only half of bcc
336 * on simple responses (wct, bcc both zero)
337 * in particular have seen this on
338 * ulogoffX and FindClose. This leaves
339 * one byte of bcc potentially unitialized
341 /* zero rest of bcc */
342 tmp[sizeof(struct smb_hdr)+1] = 0;
343 return 0;
345 cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
346 } else {
347 cifs_dbg(VFS, "Length less than smb header size\n");
349 return -EIO;
352 /* otherwise, there is enough to get to the BCC */
353 if (check_smb_hdr(smb))
354 return -EIO;
355 clc_len = smbCalcSize(smb);
357 if (4 + rfclen != total_read) {
358 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
359 rfclen);
360 return -EIO;
363 if (4 + rfclen != clc_len) {
364 __u16 mid = get_mid(smb);
365 /* check if bcc wrapped around for large read responses */
366 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
367 /* check if lengths match mod 64K */
368 if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
369 return 0; /* bcc wrapped */
371 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
372 clc_len, 4 + rfclen, mid);
374 if (4 + rfclen < clc_len) {
375 cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
376 rfclen, mid);
377 return -EIO;
378 } else if (rfclen > clc_len + 512) {
380 * Some servers (Windows XP in particular) send more
381 * data than the lengths in the SMB packet would
382 * indicate on certain calls (byte range locks and
383 * trans2 find first calls in particular). While the
384 * client can handle such a frame by ignoring the
385 * trailing data, we choose limit the amount of extra
386 * data to 512 bytes.
388 cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
389 rfclen, mid);
390 return -EIO;
393 return 0;
396 bool
397 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
399 struct smb_hdr *buf = (struct smb_hdr *)buffer;
400 struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
401 struct list_head *tmp, *tmp1, *tmp2;
402 struct cifs_ses *ses;
403 struct cifs_tcon *tcon;
404 struct cifsInodeInfo *pCifsInode;
405 struct cifsFileInfo *netfile;
407 cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
408 if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
409 (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
410 struct smb_com_transaction_change_notify_rsp *pSMBr =
411 (struct smb_com_transaction_change_notify_rsp *)buf;
412 struct file_notify_information *pnotify;
413 __u32 data_offset = 0;
414 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
415 data_offset = le32_to_cpu(pSMBr->DataOffset);
417 pnotify = (struct file_notify_information *)
418 ((char *)&pSMBr->hdr.Protocol + data_offset);
419 cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
420 pnotify->FileName, pnotify->Action);
421 /* cifs_dump_mem("Rcvd notify Data: ",buf,
422 sizeof(struct smb_hdr)+60); */
423 return true;
425 if (pSMBr->hdr.Status.CifsError) {
426 cifs_dbg(FYI, "notify err 0x%x\n",
427 pSMBr->hdr.Status.CifsError);
428 return true;
430 return false;
432 if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
433 return false;
434 if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
435 /* no sense logging error on invalid handle on oplock
436 break - harmless race between close request and oplock
437 break response is expected from time to time writing out
438 large dirty files cached on the client */
439 if ((NT_STATUS_INVALID_HANDLE) ==
440 le32_to_cpu(pSMB->hdr.Status.CifsError)) {
441 cifs_dbg(FYI, "invalid handle on oplock break\n");
442 return true;
443 } else if (ERRbadfid ==
444 le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
445 return true;
446 } else {
447 return false; /* on valid oplock brk we get "request" */
450 if (pSMB->hdr.WordCount != 8)
451 return false;
453 cifs_dbg(FYI, "oplock type 0x%x level 0x%x\n",
454 pSMB->LockType, pSMB->OplockLevel);
455 if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
456 return false;
458 /* look up tcon based on tid & uid */
459 spin_lock(&cifs_tcp_ses_lock);
460 list_for_each(tmp, &srv->smb_ses_list) {
461 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
462 list_for_each(tmp1, &ses->tcon_list) {
463 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
464 if (tcon->tid != buf->Tid)
465 continue;
467 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
468 spin_lock(&cifs_file_list_lock);
469 list_for_each(tmp2, &tcon->openFileList) {
470 netfile = list_entry(tmp2, struct cifsFileInfo,
471 tlist);
472 if (pSMB->Fid != netfile->fid.netfid)
473 continue;
475 cifs_dbg(FYI, "file id match, oplock break\n");
476 pCifsInode = CIFS_I(d_inode(netfile->dentry));
478 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
479 &pCifsInode->flags);
482 * Set flag if the server downgrades the oplock
483 * to L2 else clear.
485 if (pSMB->OplockLevel)
486 set_bit(
487 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
488 &pCifsInode->flags);
489 else
490 clear_bit(
491 CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
492 &pCifsInode->flags);
494 queue_work(cifsiod_wq,
495 &netfile->oplock_break);
496 netfile->oplock_break_cancelled = false;
498 spin_unlock(&cifs_file_list_lock);
499 spin_unlock(&cifs_tcp_ses_lock);
500 return true;
502 spin_unlock(&cifs_file_list_lock);
503 spin_unlock(&cifs_tcp_ses_lock);
504 cifs_dbg(FYI, "No matching file for oplock break\n");
505 return true;
508 spin_unlock(&cifs_tcp_ses_lock);
509 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
510 return true;
513 void
514 dump_smb(void *buf, int smb_buf_length)
516 if (traceSMB == 0)
517 return;
519 print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_NONE, 8, 2, buf,
520 smb_buf_length, true);
523 void
524 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
526 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
527 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
528 cifs_dbg(VFS, "Autodisabling the use of server inode numbers on %s. This server doesn't seem to support them properly. Hardlinks will not be recognized on this mount. Consider mounting with the \"noserverino\" option to silence this message.\n",
529 cifs_sb_master_tcon(cifs_sb)->treeName);
533 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
535 oplock &= 0xF;
537 if (oplock == OPLOCK_EXCLUSIVE) {
538 cinode->oplock = CIFS_CACHE_WRITE_FLG | CIFS_CACHE_READ_FLG;
539 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
540 &cinode->vfs_inode);
541 } else if (oplock == OPLOCK_READ) {
542 cinode->oplock = CIFS_CACHE_READ_FLG;
543 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
544 &cinode->vfs_inode);
545 } else
546 cinode->oplock = 0;
550 * We wait for oplock breaks to be processed before we attempt to perform
551 * writes.
553 int cifs_get_writer(struct cifsInodeInfo *cinode)
555 int rc;
557 start:
558 rc = wait_on_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK,
559 TASK_KILLABLE);
560 if (rc)
561 return rc;
563 spin_lock(&cinode->writers_lock);
564 if (!cinode->writers)
565 set_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
566 cinode->writers++;
567 /* Check to see if we have started servicing an oplock break */
568 if (test_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags)) {
569 cinode->writers--;
570 if (cinode->writers == 0) {
571 clear_bit(CIFS_INODE_PENDING_WRITERS, &cinode->flags);
572 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_WRITERS);
574 spin_unlock(&cinode->writers_lock);
575 goto start;
577 spin_unlock(&cinode->writers_lock);
578 return 0;
581 void cifs_put_writer(struct cifsInodeInfo *cinode)
583 spin_lock(&cinode->writers_lock);
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);
589 spin_unlock(&cinode->writers_lock);
592 void cifs_done_oplock_break(struct cifsInodeInfo *cinode)
594 clear_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
595 wake_up_bit(&cinode->flags, CIFS_INODE_PENDING_OPLOCK_BREAK);
598 bool
599 backup_cred(struct cifs_sb_info *cifs_sb)
601 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
602 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
603 return true;
605 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
606 if (in_group_p(cifs_sb->mnt_backupgid))
607 return true;
610 return false;
613 void
614 cifs_del_pending_open(struct cifs_pending_open *open)
616 spin_lock(&cifs_file_list_lock);
617 list_del(&open->olist);
618 spin_unlock(&cifs_file_list_lock);
621 void
622 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
623 struct cifs_pending_open *open)
625 #ifdef CONFIG_CIFS_SMB2
626 memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
627 #endif
628 open->oplock = CIFS_OPLOCK_NO_CHANGE;
629 open->tlink = tlink;
630 fid->pending_open = open;
631 list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
634 void
635 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
636 struct cifs_pending_open *open)
638 spin_lock(&cifs_file_list_lock);
639 cifs_add_pending_open_locked(fid, tlink, open);
640 spin_unlock(&cifs_file_list_lock);