Merge git://www.linux-watchdog.org/linux-watchdog
[platform/adaptation/renesas_rcar/renesas_kernel.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                 cifs_dbg(FYI, "warning: more than 65000 requests active\n");
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                 cifs_dbg(FYI, "Null buffer passed to sesInfoFree\n");
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                 cifs_dbg(FYI, "Null buffer passed to tconInfoFree\n");
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                 /* cifs_dbg(FYI, "Null buffer passed to cifs_buf_release\n");*/
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                 cifs_dbg(FYI, "Null buffer passed to cifs_small_buf_release\n");
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->sign)
271                                 buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
272         }
273
274 /*  endian conversion of flags is now done just before sending */
275         buffer->WordCount = (char) word_count;
276         return;
277 }
278
279 static int
280 check_smb_hdr(struct smb_hdr *smb, __u16 mid)
281 {
282         /* does it have the right SMB "signature" ? */
283         if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
284                 cifs_dbg(VFS, "Bad protocol string signature header 0x%x\n",
285                          *(unsigned int *)smb->Protocol);
286                 return 1;
287         }
288
289         /* Make sure that message ids match */
290         if (mid != smb->Mid) {
291                 cifs_dbg(VFS, "Mids do not match. received=%u expected=%u\n",
292                          smb->Mid, mid);
293                 return 1;
294         }
295
296         /* if it's a response then accept */
297         if (smb->Flags & SMBFLG_RESPONSE)
298                 return 0;
299
300         /* only one valid case where server sends us request */
301         if (smb->Command == SMB_COM_LOCKING_ANDX)
302                 return 0;
303
304         cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", smb->Mid);
305         return 1;
306 }
307
308 int
309 checkSMB(char *buf, unsigned int total_read)
310 {
311         struct smb_hdr *smb = (struct smb_hdr *)buf;
312         __u16 mid = smb->Mid;
313         __u32 rfclen = be32_to_cpu(smb->smb_buf_length);
314         __u32 clc_len;  /* calculated length */
315         cifs_dbg(FYI, "checkSMB Length: 0x%x, smb_buf_length: 0x%x\n",
316                  total_read, rfclen);
317
318         /* is this frame too small to even get to a BCC? */
319         if (total_read < 2 + sizeof(struct smb_hdr)) {
320                 if ((total_read >= sizeof(struct smb_hdr) - 1)
321                             && (smb->Status.CifsError != 0)) {
322                         /* it's an error return */
323                         smb->WordCount = 0;
324                         /* some error cases do not return wct and bcc */
325                         return 0;
326                 } else if ((total_read == sizeof(struct smb_hdr) + 1) &&
327                                 (smb->WordCount == 0)) {
328                         char *tmp = (char *)smb;
329                         /* Need to work around a bug in two servers here */
330                         /* First, check if the part of bcc they sent was zero */
331                         if (tmp[sizeof(struct smb_hdr)] == 0) {
332                                 /* some servers return only half of bcc
333                                  * on simple responses (wct, bcc both zero)
334                                  * in particular have seen this on
335                                  * ulogoffX and FindClose. This leaves
336                                  * one byte of bcc potentially unitialized
337                                  */
338                                 /* zero rest of bcc */
339                                 tmp[sizeof(struct smb_hdr)+1] = 0;
340                                 return 0;
341                         }
342                         cifs_dbg(VFS, "rcvd invalid byte count (bcc)\n");
343                 } else {
344                         cifs_dbg(VFS, "Length less than smb header size\n");
345                 }
346                 return -EIO;
347         }
348
349         /* otherwise, there is enough to get to the BCC */
350         if (check_smb_hdr(smb, mid))
351                 return -EIO;
352         clc_len = smbCalcSize(smb);
353
354         if (4 + rfclen != total_read) {
355                 cifs_dbg(VFS, "Length read does not match RFC1001 length %d\n",
356                          rfclen);
357                 return -EIO;
358         }
359
360         if (4 + rfclen != clc_len) {
361                 /* check if bcc wrapped around for large read responses */
362                 if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
363                         /* check if lengths match mod 64K */
364                         if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
365                                 return 0; /* bcc wrapped */
366                 }
367                 cifs_dbg(FYI, "Calculated size %u vs length %u mismatch for mid=%u\n",
368                          clc_len, 4 + rfclen, smb->Mid);
369
370                 if (4 + rfclen < clc_len) {
371                         cifs_dbg(VFS, "RFC1001 size %u smaller than SMB for mid=%u\n",
372                                  rfclen, smb->Mid);
373                         return -EIO;
374                 } else if (rfclen > clc_len + 512) {
375                         /*
376                          * Some servers (Windows XP in particular) send more
377                          * data than the lengths in the SMB packet would
378                          * indicate on certain calls (byte range locks and
379                          * trans2 find first calls in particular). While the
380                          * client can handle such a frame by ignoring the
381                          * trailing data, we choose limit the amount of extra
382                          * data to 512 bytes.
383                          */
384                         cifs_dbg(VFS, "RFC1001 size %u more than 512 bytes larger than SMB for mid=%u\n",
385                                  rfclen, smb->Mid);
386                         return -EIO;
387                 }
388         }
389         return 0;
390 }
391
392 bool
393 is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
394 {
395         struct smb_hdr *buf = (struct smb_hdr *)buffer;
396         struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
397         struct list_head *tmp, *tmp1, *tmp2;
398         struct cifs_ses *ses;
399         struct cifs_tcon *tcon;
400         struct cifsInodeInfo *pCifsInode;
401         struct cifsFileInfo *netfile;
402
403         cifs_dbg(FYI, "Checking for oplock break or dnotify response\n");
404         if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
405            (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
406                 struct smb_com_transaction_change_notify_rsp *pSMBr =
407                         (struct smb_com_transaction_change_notify_rsp *)buf;
408                 struct file_notify_information *pnotify;
409                 __u32 data_offset = 0;
410                 if (get_bcc(buf) > sizeof(struct file_notify_information)) {
411                         data_offset = le32_to_cpu(pSMBr->DataOffset);
412
413                         pnotify = (struct file_notify_information *)
414                                 ((char *)&pSMBr->hdr.Protocol + data_offset);
415                         cifs_dbg(FYI, "dnotify on %s Action: 0x%x\n",
416                                  pnotify->FileName, pnotify->Action);
417                         /*   cifs_dump_mem("Rcvd notify Data: ",buf,
418                                 sizeof(struct smb_hdr)+60); */
419                         return true;
420                 }
421                 if (pSMBr->hdr.Status.CifsError) {
422                         cifs_dbg(FYI, "notify err 0x%d\n",
423                                  pSMBr->hdr.Status.CifsError);
424                         return true;
425                 }
426                 return false;
427         }
428         if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
429                 return false;
430         if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
431                 /* no sense logging error on invalid handle on oplock
432                    break - harmless race between close request and oplock
433                    break response is expected from time to time writing out
434                    large dirty files cached on the client */
435                 if ((NT_STATUS_INVALID_HANDLE) ==
436                    le32_to_cpu(pSMB->hdr.Status.CifsError)) {
437                         cifs_dbg(FYI, "invalid handle on oplock break\n");
438                         return true;
439                 } else if (ERRbadfid ==
440                    le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
441                         return true;
442                 } else {
443                         return false; /* on valid oplock brk we get "request" */
444                 }
445         }
446         if (pSMB->hdr.WordCount != 8)
447                 return false;
448
449         cifs_dbg(FYI, "oplock type 0x%d level 0x%d\n",
450                  pSMB->LockType, pSMB->OplockLevel);
451         if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
452                 return false;
453
454         /* look up tcon based on tid & uid */
455         spin_lock(&cifs_tcp_ses_lock);
456         list_for_each(tmp, &srv->smb_ses_list) {
457                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
458                 list_for_each(tmp1, &ses->tcon_list) {
459                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
460                         if (tcon->tid != buf->Tid)
461                                 continue;
462
463                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
464                         spin_lock(&cifs_file_list_lock);
465                         list_for_each(tmp2, &tcon->openFileList) {
466                                 netfile = list_entry(tmp2, struct cifsFileInfo,
467                                                      tlist);
468                                 if (pSMB->Fid != netfile->fid.netfid)
469                                         continue;
470
471                                 cifs_dbg(FYI, "file id match, oplock break\n");
472                                 pCifsInode = CIFS_I(netfile->dentry->d_inode);
473
474                                 cifs_set_oplock_level(pCifsInode,
475                                         pSMB->OplockLevel ? OPLOCK_READ : 0);
476                                 queue_work(cifsiod_wq,
477                                            &netfile->oplock_break);
478                                 netfile->oplock_break_cancelled = false;
479
480                                 spin_unlock(&cifs_file_list_lock);
481                                 spin_unlock(&cifs_tcp_ses_lock);
482                                 return true;
483                         }
484                         spin_unlock(&cifs_file_list_lock);
485                         spin_unlock(&cifs_tcp_ses_lock);
486                         cifs_dbg(FYI, "No matching file for oplock break\n");
487                         return true;
488                 }
489         }
490         spin_unlock(&cifs_tcp_ses_lock);
491         cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
492         return true;
493 }
494
495 void
496 dump_smb(void *buf, int smb_buf_length)
497 {
498         int i, j;
499         char debug_line[17];
500         unsigned char *buffer = buf;
501
502         if (traceSMB == 0)
503                 return;
504
505         for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
506                 if (i % 8 == 0) {
507                         /* have reached the beginning of line */
508                         printk(KERN_DEBUG "| ");
509                         j = 0;
510                 }
511                 printk("%0#4x ", buffer[i]);
512                 debug_line[2 * j] = ' ';
513                 if (isprint(buffer[i]))
514                         debug_line[1 + (2 * j)] = buffer[i];
515                 else
516                         debug_line[1 + (2 * j)] = '_';
517
518                 if (i % 8 == 7) {
519                         /* reached end of line, time to print ascii */
520                         debug_line[16] = 0;
521                         printk(" | %s\n", debug_line);
522                 }
523         }
524         for (; j < 8; j++) {
525                 printk("     ");
526                 debug_line[2 * j] = ' ';
527                 debug_line[1 + (2 * j)] = ' ';
528         }
529         printk(" | %s\n", debug_line);
530         return;
531 }
532
533 void
534 cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
535 {
536         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
537                 cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
538                 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",
539                          cifs_sb_master_tcon(cifs_sb)->treeName);
540         }
541 }
542
543 void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
544 {
545         oplock &= 0xF;
546
547         if (oplock == OPLOCK_EXCLUSIVE) {
548                 cinode->clientCanCacheAll = true;
549                 cinode->clientCanCacheRead = true;
550                 cifs_dbg(FYI, "Exclusive Oplock granted on inode %p\n",
551                          &cinode->vfs_inode);
552         } else if (oplock == OPLOCK_READ) {
553                 cinode->clientCanCacheAll = false;
554                 cinode->clientCanCacheRead = true;
555                 cifs_dbg(FYI, "Level II Oplock granted on inode %p\n",
556                          &cinode->vfs_inode);
557         } else {
558                 cinode->clientCanCacheAll = false;
559                 cinode->clientCanCacheRead = false;
560         }
561 }
562
563 bool
564 backup_cred(struct cifs_sb_info *cifs_sb)
565 {
566         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
567                 if (uid_eq(cifs_sb->mnt_backupuid, current_fsuid()))
568                         return true;
569         }
570         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
571                 if (in_group_p(cifs_sb->mnt_backupgid))
572                         return true;
573         }
574
575         return false;
576 }
577
578 void
579 cifs_del_pending_open(struct cifs_pending_open *open)
580 {
581         spin_lock(&cifs_file_list_lock);
582         list_del(&open->olist);
583         spin_unlock(&cifs_file_list_lock);
584 }
585
586 void
587 cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
588                              struct cifs_pending_open *open)
589 {
590 #ifdef CONFIG_CIFS_SMB2
591         memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
592 #endif
593         open->oplock = CIFS_OPLOCK_NO_CHANGE;
594         open->tlink = tlink;
595         fid->pending_open = open;
596         list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
597 }
598
599 void
600 cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
601                       struct cifs_pending_open *open)
602 {
603         spin_lock(&cifs_file_list_lock);
604         cifs_add_pending_open_locked(fid, tlink, open);
605         spin_unlock(&cifs_file_list_lock);
606 }