summaryrefslogtreecommitdiff
path: root/fs/cifs/misc.c
blob: 3a00c0d0cead9d6836f4e449f679a6909f14a89e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
/*
 *   fs/cifs/misc.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002,2008
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/mempool.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
#include "smberr.h"
#include "nterr.h"
#include "cifs_unicode.h"
#ifdef CONFIG_CIFS_SMB2
#include "smb2pdu.h"
#endif

extern mempool_t *cifs_sm_req_poolp;
extern mempool_t *cifs_req_poolp;

/* The xid serves as a useful identifier for each incoming vfs request,
   in a similar way to the mid which is useful to track each sent smb,
   and CurrentXid can also provide a running counter (although it
   will eventually wrap past zero) of the total vfs operations handled
   since the cifs fs was mounted */

unsigned int
_get_xid(void)
{
	unsigned int xid;

	spin_lock(&GlobalMid_Lock);
	GlobalTotalActiveXid++;

	/* keep high water mark for number of simultaneous ops in filesystem */
	if (GlobalTotalActiveXid > GlobalMaxActiveXid)
		GlobalMaxActiveXid = GlobalTotalActiveXid;
	if (GlobalTotalActiveXid > 65000)
		cFYI(1, "warning: more than 65000 requests active");
	xid = GlobalCurrentXid++;
	spin_unlock(&GlobalMid_Lock);
	return xid;
}

void
_free_xid(unsigned int xid)
{
	spin_lock(&GlobalMid_Lock);
	/* if (GlobalTotalActiveXid == 0)
		BUG(); */
	GlobalTotalActiveXid--;
	spin_unlock(&GlobalMid_Lock);
}

struct cifs_ses *
sesInfoAlloc(void)
{
	struct cifs_ses *ret_buf;

	ret_buf = kzalloc(sizeof(struct cifs_ses), GFP_KERNEL);
	if (ret_buf) {
		atomic_inc(&sesInfoAllocCount);
		ret_buf->status = CifsNew;
		++ret_buf->ses_count;
		INIT_LIST_HEAD(&ret_buf->smb_ses_list);
		INIT_LIST_HEAD(&ret_buf->tcon_list);
		mutex_init(&ret_buf->session_mutex);
	}
	return ret_buf;
}

void
sesInfoFree(struct cifs_ses *buf_to_free)
{
	if (buf_to_free == NULL) {
		cFYI(1, "Null buffer passed to sesInfoFree");
		return;
	}

	atomic_dec(&sesInfoAllocCount);
	kfree(buf_to_free->serverOS);
	kfree(buf_to_free->serverDomain);
	kfree(buf_to_free->serverNOS);
	if (buf_to_free->password) {
		memset(buf_to_free->password, 0, strlen(buf_to_free->password));
		kfree(buf_to_free->password);
	}
	kfree(buf_to_free->user_name);
	kfree(buf_to_free->domainName);
	kfree(buf_to_free);
}

struct cifs_tcon *
tconInfoAlloc(void)
{
	struct cifs_tcon *ret_buf;
	ret_buf = kzalloc(sizeof(struct cifs_tcon), GFP_KERNEL);
	if (ret_buf) {
		atomic_inc(&tconInfoAllocCount);
		ret_buf->tidStatus = CifsNew;
		++ret_buf->tc_count;
		INIT_LIST_HEAD(&ret_buf->openFileList);
		INIT_LIST_HEAD(&ret_buf->tcon_list);
#ifdef CONFIG_CIFS_STATS
		spin_lock_init(&ret_buf->stat_lock);
#endif
	}
	return ret_buf;
}

void
tconInfoFree(struct cifs_tcon *buf_to_free)
{
	if (buf_to_free == NULL) {
		cFYI(1, "Null buffer passed to tconInfoFree");
		return;
	}
	atomic_dec(&tconInfoAllocCount);
	kfree(buf_to_free->nativeFileSystem);
	if (buf_to_free->password) {
		memset(buf_to_free->password, 0, strlen(buf_to_free->password));
		kfree(buf_to_free->password);
	}
	kfree(buf_to_free);
}

struct smb_hdr *
cifs_buf_get(void)
{
	struct smb_hdr *ret_buf = NULL;
	size_t buf_size = sizeof(struct smb_hdr);

#ifdef CONFIG_CIFS_SMB2
	/*
	 * SMB2 header is bigger than CIFS one - no problems to clean some
	 * more bytes for CIFS.
	 */
	buf_size = sizeof(struct smb2_hdr);
#endif
	/*
	 * We could use negotiated size instead of max_msgsize -
	 * but it may be more efficient to always alloc same size
	 * albeit slightly larger than necessary and maxbuffersize
	 * defaults to this and can not be bigger.
	 */
	ret_buf = mempool_alloc(cifs_req_poolp, GFP_NOFS);

	/* clear the first few header bytes */
	/* for most paths, more is cleared in header_assemble */
	if (ret_buf) {
		memset(ret_buf, 0, buf_size + 3);
		atomic_inc(&bufAllocCount);
#ifdef CONFIG_CIFS_STATS2
		atomic_inc(&totBufAllocCount);
#endif /* CONFIG_CIFS_STATS2 */
	}

	return ret_buf;
}

void
cifs_buf_release(void *buf_to_free)
{
	if (buf_to_free == NULL) {
		/* cFYI(1, "Null buffer passed to cifs_buf_release");*/
		return;
	}
	mempool_free(buf_to_free, cifs_req_poolp);

	atomic_dec(&bufAllocCount);
	return;
}

struct smb_hdr *
cifs_small_buf_get(void)
{
	struct smb_hdr *ret_buf = NULL;

/* We could use negotiated size instead of max_msgsize -
   but it may be more efficient to always alloc same size
   albeit slightly larger than necessary and maxbuffersize
   defaults to this and can not be bigger */
	ret_buf = mempool_alloc(cifs_sm_req_poolp, GFP_NOFS);
	if (ret_buf) {
	/* No need to clear memory here, cleared in header assemble */
	/*	memset(ret_buf, 0, sizeof(struct smb_hdr) + 27);*/
		atomic_inc(&smBufAllocCount);
#ifdef CONFIG_CIFS_STATS2
		atomic_inc(&totSmBufAllocCount);
#endif /* CONFIG_CIFS_STATS2 */

	}
	return ret_buf;
}

void
cifs_small_buf_release(void *buf_to_free)
{

	if (buf_to_free == NULL) {
		cFYI(1, "Null buffer passed to cifs_small_buf_release");
		return;
	}
	mempool_free(buf_to_free, cifs_sm_req_poolp);

	atomic_dec(&smBufAllocCount);
	return;
}

/* NB: MID can not be set if treeCon not passed in, in that
   case it is responsbility of caller to set the mid */
void
header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
		const struct cifs_tcon *treeCon, int word_count
		/* length of fixed section (word count) in two byte units  */)
{
	char *temp = (char *) buffer;

	memset(temp, 0, 256); /* bigger than MAX_CIFS_HDR_SIZE */

	buffer->smb_buf_length = cpu_to_be32(
	    (2 * word_count) + sizeof(struct smb_hdr) -
	    4 /*  RFC 1001 length field does not count */  +
	    2 /* for bcc field itself */) ;

	buffer->Protocol[0] = 0xFF;
	buffer->Protocol[1] = 'S';
	buffer->Protocol[2] = 'M';
	buffer->Protocol[3] = 'B';
	buffer->Command = smb_command;
	buffer->Flags = 0x00;	/* case sensitive */
	buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
	buffer->Pid = cpu_to_le16((__u16)current->tgid);
	buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
	if (treeCon) {
		buffer->Tid = treeCon->tid;
		if (treeCon->ses) {
			if (treeCon->ses->capabilities & CAP_UNICODE)
				buffer->Flags2 |= SMBFLG2_UNICODE;
			if (treeCon->ses->capabilities & CAP_STATUS32)
				buffer->Flags2 |= SMBFLG2_ERR_STATUS;

			/* Uid is not converted */
			buffer->Uid = treeCon->ses->Suid;
			buffer->Mid = get_next_mid(treeCon->ses->server);
		}
		if (treeCon->Flags & SMB_SHARE_IS_IN_DFS)
			buffer->Flags2 |= SMBFLG2_DFS;
		if (treeCon->nocase)
			buffer->Flags  |= SMBFLG_CASELESS;
		if ((treeCon->ses) && (treeCon->ses->server))
			if (treeCon->ses->server->sec_mode &
			  (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
				buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
	}

/*  endian conversion of flags is now done just before sending */
	buffer->WordCount = (char) word_count;
	return;
}

static int
check_smb_hdr(struct smb_hdr *smb, __u16 mid)
{
	/* does it have the right SMB "signature" ? */
	if (*(__le32 *) smb->Protocol != cpu_to_le32(0x424d53ff)) {
		cERROR(1, "Bad protocol string signature header 0x%x",
			*(unsigned int *)smb->Protocol);
		return 1;
	}

	/* Make sure that message ids match */
	if (mid != smb->Mid) {
		cERROR(1, "Mids do not match. received=%u expected=%u",
			smb->Mid, mid);
		return 1;
	}

	/* if it's a response then accept */
	if (smb->Flags & SMBFLG_RESPONSE)
		return 0;

	/* only one valid case where server sends us request */
	if (smb->Command == SMB_COM_LOCKING_ANDX)
		return 0;

	cERROR(1, "Server sent request, not response. mid=%u", smb->Mid);
	return 1;
}

int
checkSMB(char *buf, unsigned int total_read)
{
	struct smb_hdr *smb = (struct smb_hdr *)buf;
	__u16 mid = smb->Mid;
	__u32 rfclen = be32_to_cpu(smb->smb_buf_length);
	__u32 clc_len;  /* calculated length */
	cFYI(0, "checkSMB Length: 0x%x, smb_buf_length: 0x%x",
		total_read, rfclen);

	/* is this frame too small to even get to a BCC? */
	if (total_read < 2 + sizeof(struct smb_hdr)) {
		if ((total_read >= sizeof(struct smb_hdr) - 1)
			    && (smb->Status.CifsError != 0)) {
			/* it's an error return */
			smb->WordCount = 0;
			/* some error cases do not return wct and bcc */
			return 0;
		} else if ((total_read == sizeof(struct smb_hdr) + 1) &&
				(smb->WordCount == 0)) {
			char *tmp = (char *)smb;
			/* Need to work around a bug in two servers here */
			/* First, check if the part of bcc they sent was zero */
			if (tmp[sizeof(struct smb_hdr)] == 0) {
				/* some servers return only half of bcc
				 * on simple responses (wct, bcc both zero)
				 * in particular have seen this on
				 * ulogoffX and FindClose. This leaves
				 * one byte of bcc potentially unitialized
				 */
				/* zero rest of bcc */
				tmp[sizeof(struct smb_hdr)+1] = 0;
				return 0;
			}
			cERROR(1, "rcvd invalid byte count (bcc)");
		} else {
			cERROR(1, "Length less than smb header size");
		}
		return -EIO;
	}

	/* otherwise, there is enough to get to the BCC */
	if (check_smb_hdr(smb, mid))
		return -EIO;
	clc_len = smbCalcSize(smb);

	if (4 + rfclen != total_read) {
		cERROR(1, "Length read does not match RFC1001 length %d",
				rfclen);
		return -EIO;
	}

	if (4 + rfclen != clc_len) {
		/* check if bcc wrapped around for large read responses */
		if ((rfclen > 64 * 1024) && (rfclen > clc_len)) {
			/* check if lengths match mod 64K */
			if (((4 + rfclen) & 0xFFFF) == (clc_len & 0xFFFF))
				return 0; /* bcc wrapped */
		}
		cFYI(1, "Calculated size %u vs length %u mismatch for mid=%u",
				clc_len, 4 + rfclen, smb->Mid);

		if (4 + rfclen < clc_len) {
			cERROR(1, "RFC1001 size %u smaller than SMB for mid=%u",
					rfclen, smb->Mid);
			return -EIO;
		} else if (rfclen > clc_len + 512) {
			/*
			 * Some servers (Windows XP in particular) send more
			 * data than the lengths in the SMB packet would
			 * indicate on certain calls (byte range locks and
			 * trans2 find first calls in particular). While the
			 * client can handle such a frame by ignoring the
			 * trailing data, we choose limit the amount of extra
			 * data to 512 bytes.
			 */
			cERROR(1, "RFC1001 size %u more than 512 bytes larger "
				  "than SMB for mid=%u", rfclen, smb->Mid);
			return -EIO;
		}
	}
	return 0;
}

bool
is_valid_oplock_break(char *buffer, struct TCP_Server_Info *srv)
{
	struct smb_hdr *buf = (struct smb_hdr *)buffer;
	struct smb_com_lock_req *pSMB = (struct smb_com_lock_req *)buf;
	struct list_head *tmp, *tmp1, *tmp2;
	struct cifs_ses *ses;
	struct cifs_tcon *tcon;
	struct cifsInodeInfo *pCifsInode;
	struct cifsFileInfo *netfile;

	cFYI(1, "Checking for oplock break or dnotify response");
	if ((pSMB->hdr.Command == SMB_COM_NT_TRANSACT) &&
	   (pSMB->hdr.Flags & SMBFLG_RESPONSE)) {
		struct smb_com_transaction_change_notify_rsp *pSMBr =
			(struct smb_com_transaction_change_notify_rsp *)buf;
		struct file_notify_information *pnotify;
		__u32 data_offset = 0;
		if (get_bcc(buf) > sizeof(struct file_notify_information)) {
			data_offset = le32_to_cpu(pSMBr->DataOffset);

			pnotify = (struct file_notify_information *)
				((char *)&pSMBr->hdr.Protocol + data_offset);
			cFYI(1, "dnotify on %s Action: 0x%x",
				 pnotify->FileName, pnotify->Action);
			/*   cifs_dump_mem("Rcvd notify Data: ",buf,
				sizeof(struct smb_hdr)+60); */
			return true;
		}
		if (pSMBr->hdr.Status.CifsError) {
			cFYI(1, "notify err 0x%d",
				pSMBr->hdr.Status.CifsError);
			return true;
		}
		return false;
	}
	if (pSMB->hdr.Command != SMB_COM_LOCKING_ANDX)
		return false;
	if (pSMB->hdr.Flags & SMBFLG_RESPONSE) {
		/* no sense logging error on invalid handle on oplock
		   break - harmless race between close request and oplock
		   break response is expected from time to time writing out
		   large dirty files cached on the client */
		if ((NT_STATUS_INVALID_HANDLE) ==
		   le32_to_cpu(pSMB->hdr.Status.CifsError)) {
			cFYI(1, "invalid handle on oplock break");
			return true;
		} else if (ERRbadfid ==
		   le16_to_cpu(pSMB->hdr.Status.DosError.Error)) {
			return true;
		} else {
			return false; /* on valid oplock brk we get "request" */
		}
	}
	if (pSMB->hdr.WordCount != 8)
		return false;

	cFYI(1, "oplock type 0x%d level 0x%d",
		 pSMB->LockType, pSMB->OplockLevel);
	if (!(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE))
		return false;

	/* look up tcon based on tid & uid */
	spin_lock(&cifs_tcp_ses_lock);
	list_for_each(tmp, &srv->smb_ses_list) {
		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
		list_for_each(tmp1, &ses->tcon_list) {
			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
			if (tcon->tid != buf->Tid)
				continue;

			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
			spin_lock(&cifs_file_list_lock);
			list_for_each(tmp2, &tcon->openFileList) {
				netfile = list_entry(tmp2, struct cifsFileInfo,
						     tlist);
				if (pSMB->Fid != netfile->fid.netfid)
					continue;

				cFYI(1, "file id match, oplock break");
				pCifsInode = CIFS_I(netfile->dentry->d_inode);

				cifs_set_oplock_level(pCifsInode,
					pSMB->OplockLevel ? OPLOCK_READ : 0);
				queue_work(cifsiod_wq,
					   &netfile->oplock_break);
				netfile->oplock_break_cancelled = false;

				spin_unlock(&cifs_file_list_lock);
				spin_unlock(&cifs_tcp_ses_lock);
				return true;
			}
			spin_unlock(&cifs_file_list_lock);
			spin_unlock(&cifs_tcp_ses_lock);
			cFYI(1, "No matching file for oplock break");
			return true;
		}
	}
	spin_unlock(&cifs_tcp_ses_lock);
	cFYI(1, "Can not process oplock break for non-existent connection");
	return true;
}

void
dump_smb(void *buf, int smb_buf_length)
{
	int i, j;
	char debug_line[17];
	unsigned char *buffer = buf;

	if (traceSMB == 0)
		return;

	for (i = 0, j = 0; i < smb_buf_length; i++, j++) {
		if (i % 8 == 0) {
			/* have reached the beginning of line */
			printk(KERN_DEBUG "| ");
			j = 0;
		}
		printk("%0#4x ", buffer[i]);
		debug_line[2 * j] = ' ';
		if (isprint(buffer[i]))
			debug_line[1 + (2 * j)] = buffer[i];
		else
			debug_line[1 + (2 * j)] = '_';

		if (i % 8 == 7) {
			/* reached end of line, time to print ascii */
			debug_line[16] = 0;
			printk(" | %s\n", debug_line);
		}
	}
	for (; j < 8; j++) {
		printk("     ");
		debug_line[2 * j] = ' ';
		debug_line[1 + (2 * j)] = ' ';
	}
	printk(" | %s\n", debug_line);
	return;
}

void
cifs_autodisable_serverino(struct cifs_sb_info *cifs_sb)
{
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
		cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
		cERROR(1, "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.",
			   cifs_sb_master_tcon(cifs_sb)->treeName);
	}
}

void cifs_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock)
{
	oplock &= 0xF;

	if (oplock == OPLOCK_EXCLUSIVE) {
		cinode->clientCanCacheAll = true;
		cinode->clientCanCacheRead = true;
		cFYI(1, "Exclusive Oplock granted on inode %p",
		     &cinode->vfs_inode);
	} else if (oplock == OPLOCK_READ) {
		cinode->clientCanCacheAll = false;
		cinode->clientCanCacheRead = true;
		cFYI(1, "Level II Oplock granted on inode %p",
		    &cinode->vfs_inode);
	} else {
		cinode->clientCanCacheAll = false;
		cinode->clientCanCacheRead = false;
	}
}

bool
backup_cred(struct cifs_sb_info *cifs_sb)
{
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID) {
		if (cifs_sb->mnt_backupuid == current_fsuid())
			return true;
	}
	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID) {
		if (in_group_p(cifs_sb->mnt_backupgid))
			return true;
	}

	return false;
}

void
cifs_del_pending_open(struct cifs_pending_open *open)
{
	spin_lock(&cifs_file_list_lock);
	list_del(&open->olist);
	spin_unlock(&cifs_file_list_lock);
}

void
cifs_add_pending_open_locked(struct cifs_fid *fid, struct tcon_link *tlink,
			     struct cifs_pending_open *open)
{
#ifdef CONFIG_CIFS_SMB2
	memcpy(open->lease_key, fid->lease_key, SMB2_LEASE_KEY_SIZE);
#endif
	open->oplock = CIFS_OPLOCK_NO_CHANGE;
	open->tlink = tlink;
	fid->pending_open = open;
	list_add_tail(&open->olist, &tlink_tcon(tlink)->pending_opens);
}

void
cifs_add_pending_open(struct cifs_fid *fid, struct tcon_link *tlink,
		      struct cifs_pending_open *open)
{
	spin_lock(&cifs_file_list_lock);
	cifs_add_pending_open_locked(fid, tlink, open);
	spin_unlock(&cifs_file_list_lock);
}