fix "disabling echoes and oplocks" on SMB2 mounts
[linux-3.10.git] / fs / cifs / misc.c
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 #ifdef CONFIG_CIFS_SMB2
33 #include "smb2pdu.h"
34 #endif
35
36 extern mempool_t *cifs_sm_req_poolp;
37 extern mempool_t *cifs_req_poolp;
38
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 */
44
45 unsigned int
46 _get_xid(void)
47 {
48         unsigned int xid;
49
50         spin_lock(&GlobalMid_Lock);
51         GlobalTotalActiveXid++;
52
53         /* keep high water mark for number of simultaneous ops in filesystem */
54         if (GlobalTotalActiveXid > GlobalMaxActiveXid)
55                 GlobalMaxActiveXid = GlobalTotalActiveXid;
56         if (GlobalTotalActiveXid > 65000)
57                 cFYI(1, "warning: more than 65000 requests active");
58         xid = GlobalCurrentXid++;
59         spin_unlock(&GlobalMid_Lock);
60         return xid;
61 }
62
63 void
64 _free_xid(unsigned int xid)
65 {
66         spin_lock(&GlobalMid_Lock);
67         /* if (GlobalTotalActiveXid == 0)
68                 BUG(); */
69         GlobalTotalActiveXid--;
70         spin_unlock(&GlobalMid_Lock);
71 }
72
73 struct cifs_ses *
74 sesInfoAlloc(void)
75 {
76         struct cifs_ses *ret_buf;
77
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);
86         }
87         return ret_buf;
88 }
89
90 void
91 sesInfoFree(struct cifs_ses *buf_to_free)
92 {
93         if (buf_to_free == NULL) {
94                 cFYI(1, "Null buffer passed to sesInfoFree");
95                 return;
96         }
97
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);
105         }
106         kfree(buf_to_free->user_name);
107         kfree(buf_to_free->domainName);
108         kfree(buf_to_free);
109 }
110
111 struct cifs_tcon *
112 tconInfoAlloc(void)
113 {
114         struct cifs_tcon *ret_buf;
115         ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
116         if (ret_buf) {
117                 atomic_inc(&tconInfoAllocCount);
118                 ret_buf->tidStatus = CifsNew;
119                 ++ret_buf->tc_count;
120                 INIT_LIST_HEAD(&ret_buf->openFileList);
121                 INIT_LIST_HEAD(&ret_buf->tcon_list);
122 #ifdef CONFIG_CIFS_STATS
123                 spin_lock_init(&ret_buf->stat_lock);
124 #endif
125         }
126         return ret_buf;
127 }
128
129 void
130 tconInfoFree(struct cifs_tcon *buf_to_free)
131 {
132         if (buf_to_free == NULL) {
133                 cFYI(1, "Null buffer passed to tconInfoFree");
134                 return;
135         }
136         atomic_dec(&tconInfoAllocCount);
137         kfree(buf_to_free->nativeFileSystem);
138         if (buf_to_free->password) {
139                 memset(buf_to_free->password, 0, strlen(buf_to_free->password));
140                 kfree(buf_to_free->password);
141         }
142         kfree(buf_to_free);
143 }
144
145 struct smb_hdr *
146 cifs_buf_get(void)
147 {
148         struct smb_hdr *ret_buf = NULL;
149         size_t buf_size = sizeof(struct smb_hdr);
150
151 #ifdef CONFIG_CIFS_SMB2
152         /*
153          * SMB2 header is bigger than CIFS one - no problems to clean some
154          * more bytes for CIFS.
155          */
156         buf_size = sizeof(struct smb2_hdr);
157 #endif
158         /*
159          * We could use negotiated size instead of max_msgsize -
160          * but it may be more efficient to always alloc same size
161          * albeit slightly larger than necessary and maxbuffersize
162          * defaults to this and can not be bigger.
163          */
164         ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);
165
166         /* clear the first few header bytes */
167         /* for most paths, more is cleared in header_assemble */
168         if (ret_buf) {
169                 memset(ret_buf, 0, buf_size + 3);
170                 atomic_inc(&bufAllocCount);
171 #ifdef CONFIG_CIFS_STATS2
172                 atomic_inc(&totBufAllocCount);
173 #endif /* CONFIG_CIFS_STATS2 */
174         }
175
176         return ret_buf;
177 }
178
179 void
180 cifs_buf_release(void *buf_to_free)
181 {
182         if (buf_to_free == NULL) {
183                 /* cFYI(1, "Null buffer passed to cifs_buf_release");*/
184                 return;
185         }
186         mempool_free(buf_to_free, cifs_req_poolp);
187
188         atomic_dec(&bufAllocCount);
189         return;
190 }
191
192 struct smb_hdr *
193 cifs_small_buf_get(void)
194 {
195         struct smb_hdr *ret_buf = NULL;
196
197 /* We could use negotiated size instead of max_msgsize -
198    but it may be more efficient to always alloc same size
199    albeit slightly larger than necessary and maxbuffersize
200    defaults to this and can not be bigger */
201         ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
202         if (ret_buf) {
203         /* No need to clear memory here, cleared in header assemble */
204         /*      memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
205                 atomic_inc(&smBufAllocCount);
206 #ifdef CONFIG_CIFS_STATS2
207                 atomic_inc(&totSmBufAllocCount);
208 #endif /* CONFIG_CIFS_STATS2 */
209
210         }
211         return ret_buf;
212 }
213
214 void
215 cifs_small_buf_release(void *buf_to_free)
216 {
217
218         if (buf_to_free == NULL) {
219                 cFYI(1, "Null buffer passed to cifs_small_buf_release");
220                 return;
221         }
222         mempool_free(buf_to_free, cifs_sm_req_poolp);
223
224         atomic_dec(&smBufAllocCount);
225         return;
226 }
227
228 /* NB: MID can not be set if treeCon not passed in, in that
229    case it is responsbility of caller to set the mid */
230 void
231 header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
232                 const struct cifs_tcon *treeCon, int word_count
233                 /* length of fixed section (word count) in two byte units  */)
234 {
235         char *temp = (char *) buffer;
236
237         memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */
238
239         buffer->smb_buf_length = cpu_to_be32(
240             (2 * word_count) + sizeof(struct smb_hdr) -
241             4 /*  RFC 1001 length field does not count */  +
242             2 /* for bcc field itself */) ;
243
244         buffer->Protocol[0] = 0xFF;
245         buffer->Protocol[1] = 'S';
246         buffer->Protocol[2] = 'M';
247         buffer->Protocol[3] = 'B';
248         buffer->Command = smb_command;
249         buffer->Flags = 0x00;   /* case sensitive */
250         buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
251         buffer->Pid = cpu_to_le16((__u16)current->tgid);
252         buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
253         if (treeCon) {
254                 buffer->Tid = treeCon->tid;
255                 if (treeCon->ses) {
256                         if (treeCon->ses->capabilities & CAP_UNICODE)
257                                 buffer->Flags2 |= SMBFLG2_UNICODE;
258                         if (treeCon->ses->capabilities & CAP_STATUS32)
259                                 buffer->Flags2 |= SMBFLG2_ERR_STATUS;
260
261                         /* Uid is not converted */
262                         buffer->Uid = treeCon->ses->Suid;
263                         buffer->Mid = get_next_mid(treeCon->ses->server);
264                 }
265                 if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
266                         buffer->Flags2 |= SMBFLG2_DFS;
267                 if (treeCon->nocase)
268                         buffer->Flags  |= SMBFLG_CASELESS;
269                 if ((treeCon->ses) && (treeCon->ses->server))
270                         if (treeCon->ses->server->sec_mode &
271                           (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
272                                 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
273         }
274
275 /*  endian conversion of flags is now done just before sending */
276         buffer->WordCount = (char) word_count;
277         return;
278 }
279
280 static int
281 check_smb_hdr(struct smb_hdr *smb, __u16 mid)
282 {
283         /* does it have the right SMB "signature" ? */
284         if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
285                 cERROR(1, "Bad protocol string signature header 0x%x",
286                         *(unsigned int *)smb->Protocol);
287                 return 1;
288         }
289
290         /* Make sure that message ids match */
291         if (mid != smb->Mid) {
292                 cERROR(1, "Mids do not match. received=%u expected=%u",
293                         smb->Mid, mid);
294                 return 1;
295         }
296
297         /* if it's a response then accept */
298         if (smb->Flags & SMBFLG_RESPONSE)
299                 return 0;
300
301         /* only one valid case where server sends us request */
302         if (smb->Command == SMB_COM_LOCKING_ANDX)
303                 return 0;
304
305         cERROR(1, "Server sent request, not response. mid=%u", smb->Mid);
306         return 1;
307 }
308
309 int
310 checkSMB(char *buf, unsigned int total_read)
311 {
312         struct smb_hdr *smb = (struct smb_hdr *)buf;
313         __u16 mid = smb->Mid;
314         __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
315         __u32 clc_len;  /* calculated length */
316         cFYI(0, "checkSMB Length: 0x%x, smb_buf_length: 0x%x",
317                 total_read, rfclen);
318
319         /* is this frame too small to even get to a BCC? */
320         if (total_read < 2 + sizeof(struct smb_hdr)) {
321                 if ((total_read >= sizeof(struct smb_hdr) - 1)
322                             && (smb->Status.CifsError != 0)) {
323                         /* it's an error return */
324                         smb->WordCount = 0;
325                         /* some error cases do not return wct and bcc */
326                         return 0;
327                 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
328                                 (smb->WordCount == 0)) {
329                         char *tmp = (char *)smb;
330                         /* Need to work around a bug in two servers here */
331                         /* First, check if the part of bcc they sent was zero */
332                         if (tmp[sizeof(struct smb_hdr)] == 0) {
333                                 /* some servers return only half of bcc
334                                  * on simple responses (wct, bcc both zero)
335                                  * in particular have seen this on
336                                  * ulogoffX and FindClose. This leaves
337                                  * one byte of bcc potentially unitialized
338                                  */
339                                 /* zero rest of bcc */
340                                 tmp[sizeof(struct smb_hdr)+1] = 0;
341                                 return 0;
342                         }
343                         cERROR(1, "rcvd invalid byte count (bcc)");
344                 } else {
345                         cERROR(1, "Length less than smb header size");
346                 }
347                 return -EIO;
348         }
349
350         /* otherwise, there is enough to get to the BCC */
351         if (check_smb_hdr(smb, mid))
352                 return -EIO;
353         clc_len = smbCalcSize(smb);
354
355         if (4 + rfclen != total_read) {
356                 cERROR(1, "Length read does not match RFC1001 length %d",
357                                 rfclen);
358                 return -EIO;
359         }
360
361         if (4 + rfclen != clc_len) {
362                 /* check if bcc wrapped around for large read responses */
363                 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
364                         /* check if lengths match mod 64K */
365                         if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
366                                 return 0; /* bcc wrapped */
367                 }
368                 cFYI(1, "Calculated size %u vs length %u mismatch for mid=%u",
369                                 clc_len, 4 + rfclen, smb->Mid);
370
371                 if (4 + rfclen < clc_len) {
372                         cERROR(1, "RFC1001 size %u smaller than SMB for mid=%u",
373                                         rfclen, smb->Mid);
374                         return -EIO;
375                 } else if (rfclen > clc_len + 512) {
376                         /*
377                          * Some servers (Windows XP in particular) send more
378                          * data than the lengths in the SMB packet would
379                          * indicate on certain calls (byte range locks and
380                          * trans2 find first calls in particular). While the
381                          * client can handle such a frame by ignoring the
382                          * trailing data, we choose limit the amount of extra
383                          * data to 512 bytes.
384                          */
385                         cERROR(1, "RFC1001 size %u more than 512 bytes larger "
386                                   "than SMB for mid=%u", rfclen, smb->Mid);
387                         return -EIO;
388                 }
389         }
390         return 0;
391 }
392
393 bool
394 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
395 {
396         struct smb_hdr *buf = (struct smb_hdr *)buffer;
397         struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
398         struct list_head *tmp, *tmp1, *tmp2;
399         struct cifs_ses *ses;
400         struct cifs_tcon *tcon;
401         struct cifsInodeInfo *pCifsInode;
402         struct cifsFileInfo *netfile;
403
404         cFYI(1, "Checking for oplock break or dnotify response");
405         if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
406            (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
407                 struct smb_com_transaction_change_notify_rsp *pSMBr =
408                         (struct smb_com_transaction_change_notify_rsp *)buf;
409                 struct file_notify_information *pnotify;
410                 __u32 data_offset = 0;
411                 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
412                         data_offset = le32_to_cpu(pSMBr->DataOffset);
413
414                         pnotify = (struct file_notify_information *)
415                                 ((char *)&pSMBr->hdr.Protocol + data_offset);
416                         cFYI(1, "dnotify on %s Action: 0x%x",
417                                  pnotify->FileName, pnotify->Action);
418                         /*   cifs_dump_mem("Rcvd notify Data: ",buf,
419                                 sizeof(struct smb_hdr)+60); */
420                         return true;
421                 }
422                 if (pSMBr->hdr.Status.CifsError) {
423                         cFYI(1, "notify err 0x%d",
424                                 pSMBr->hdr.Status.CifsError);
425                         return true;
426                 }
427                 return false;
428         }
429         if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
430                 return false;
431         if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
432                 /* no sense logging error on invalid handle on oplock
433                    break - harmless race between close request and oplock
434                    break response is expected from time to time writing out
435                    large dirty files cached on the client */
436                 if ((NT_STATUS_INVALID_HANDLE) ==
437                    le32_to_cpu(pSMB->hdr.Status.CifsError)) {
438                         cFYI(1, "invalid handle on oplock break");
439                         return true;
440                 } else if (ERRbadfid ==
441                    le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
442                         return true;
443                 } else {
444                         return false; /* on valid oplock brk we get "request" */
445                 }
446         }
447         if (pSMB->hdr.WordCount != 8)
448                 return false;
449
450         cFYI(1, "oplock type 0x%d level 0x%d",
451                  pSMB->LockType, pSMB->OplockLevel);
452         if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
453                 return false;
454
455         /* look up tcon based on tid & uid */
456         spin_lock(&cifs_tcp_ses_lock);
457         list_for_each(tmp, &srv->smb_ses_list) {
458                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
459                 list_for_each(tmp1, &ses->tcon_list) {
460                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
461                         if (tcon->tid != buf->Tid)
462                                 continue;
463
464                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
465                         spin_lock(&cifs_file_list_lock);
466                         list_for_each(tmp2, &tcon->openFileList) {
467                                 netfile = list_entry(tmp2, struct cifsFileInfo,
468                                                      tlist);
469                                 if (pSMB->Fid != netfile->fid.netfid)
470                                         continue;
471
472                                 cFYI(1, "file id match, oplock break");
473                                 pCifsInode = CIFS_I(netfile->dentry->d_inode);
474
475                                 cifs_set_oplock_level(pCifsInode,
476                                         pSMB->OplockLevel ? OPLOCK_READ : 0);
477                                 queue_work(cifsiod_wq,
478                                            &netfile->oplock_break);
479                                 netfile->oplock_break_cancelled = false;
480
481                                 spin_unlock(&cifs_file_list_lock);
482                                 spin_unlock(&cifs_tcp_ses_lock);
483                                 return true;
484                         }
485                         spin_unlock(&cifs_file_list_lock);
486                         spin_unlock(&cifs_tcp_ses_lock);
487                         cFYI(1, "No matching file for oplock break");
488                         return true;
489                 }
490         }
491         spin_unlock(&cifs_tcp_ses_lock);
492         cFYI(1, "Can not process oplock break for non-existent connection");
493         return true;
494 }
495
496 void
497 dump_smb(void *buf, int smb_buf_length)
498 {
499         int i, j;
500         char debug_line[17];
501         unsigned char *buffer = buf;
502
503         if (traceSMB == 0)
504                 return;
505
506         for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
507                 if (i % 8 == 0) {
508                         /* have reached the beginning of line */
509                         printk(KERN_DEBUG "| ");
510                         j = 0;
511                 }
512                 printk("%0#4x ", buffer[i]);
513                 debug_line[2 * j] = ' ';
514                 if (isprint(buffer[i]))
515                         debug_line[1 + (2 * j)] = buffer[i];
516                 else
517                         debug_line[1 + (2 * j)] = '_';
518
519                 if (i % 8 == 7) {
520                         /* reached end of line, time to print ascii */
521                         debug_line[16] = 0;
522                         printk(" | %s\n", debug_line);
523                 }
524         }
525         for (; j < 8; j++) {
526                 printk("     ");
527                 debug_line[2 * j] = ' ';
528                 debug_line[1 + (2 * j)] = ' ';
529         }
530         printk(" | %s\n", debug_line);
531         return;
532 }
533
534 void
535 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
536 {
537         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
538                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
539                 cERROR(1, "Autodisabling the use of server inode numbers on "
540                            "%s. This server doesn't seem to support them "
541                            "properly. Hardlinks will not be recognized on this "
542                            "mount. Consider mounting with the \"noserverino\" "
543                            "option to silence this message.",
544                            cifs_sb_master_tcon(cifs_sb)->treeName);
545         }
546 }
547
548 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
549 {
550         oplock &= 0xF;
551
552         if (oplock == OPLOCK_EXCLUSIVE) {
553                 cinode->clientCanCacheAll = true;
554                 cinode->clientCanCacheRead = true;
555                 cFYI(1, "Exclusive Oplock granted on inode %p",
556                      &cinode->vfs_inode);
557         } else if (oplock == OPLOCK_READ) {
558                 cinode->clientCanCacheAll = false;
559                 cinode->clientCanCacheRead = true;
560                 cFYI(1, "Level II Oplock granted on inode %p",
561                     &cinode->vfs_inode);
562         } else {
563                 cinode->clientCanCacheAll = false;
564                 cinode->clientCanCacheRead = false;
565         }
566 }
567
568 bool
569 backup_cred(struct cifs_sb_info *cifs_sb)
570 {
571         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
572                 if (cifs_sb->mnt_backupuid == current_fsuid())
573                         return true;
574         }
575         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
576                 if (in_group_p(cifs_sb->mnt_backupgid))
577                         return true;
578         }
579
580         return false;
581 }
582
583 void
584 cifs_del_pending_open(struct cifs_pending_open *open)
585 {
586         spin_lock(&cifs_file_list_lock);
587         list_del(&open->olist);
588         spin_unlock(&cifs_file_list_lock);
589 }
590
591 void
592 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
593                              struct cifs_pending_open *open)
594 {
595 #ifdef CONFIG_CIFS_SMB2
596         memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
597 #endif
598         open->oplock = CIFS_OPLOCK_NO_CHANGE;
599         open->tlink = tlink;
600         fid->pending_open = open;
601         list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
602 }
603
604 void
605 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
606                       struct cifs_pending_open *open)
607 {
608         spin_lock(&cifs_file_list_lock);
609         cifs_add_pending_open_locked(fid, tlink, open);
610         spin_unlock(&cifs_file_list_lock);
611 }