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[CIFS] cifs: Rename cERROR and cFYI to cifs_dbg
[linux-2.6.git] / fs / cifs / smb2misc.c
blob10383d8c015b12c4aa7bd936972e58bca97a648b
1 /*
2 * fs/cifs/smb2misc.c
3 *
4 * Copyright (C) International Business Machines Corp., 2002,2011
5 * Etersoft, 2012
6 * Author(s): Steve French (sfrench@us.ibm.com)
7 * Pavel Shilovsky (pshilovsky@samba.org) 2012
8 *
9 * This library is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU Lesser General Public License as published
11 * by the Free Software Foundation; either version 2.1 of the License, or
12 * (at your option) any later version.
13 *
14 * This library is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
17 * the GNU Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public License
20 * along with this library; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23 #include <linux/ctype.h>
24 #include "smb2pdu.h"
25 #include "cifsglob.h"
26 #include "cifsproto.h"
27 #include "smb2proto.h"
28 #include "cifs_debug.h"
29 #include "cifs_unicode.h"
30 #include "smb2status.h"
31
32 static int
33 check_smb2_hdr(struct smb2_hdr *hdr, __u64 mid)
34 {
35 /*
36 * Make sure that this really is an SMB, that it is a response,
37 * and that the message ids match.
38 */
39 if ((*(__le32 *)hdr->ProtocolId == SMB2_PROTO_NUMBER) &&
40 (mid == hdr->MessageId)) {
41 if (hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
42 return 0;
43 else {
44 /* only one valid case where server sends us request */
45 if (hdr->Command == SMB2_OPLOCK_BREAK)
46 return 0;
47 else
48 cifs_dbg(VFS, "Received Request not response\n");
49 }
50 } else { /* bad signature or mid */
51 if (*(__le32 *)hdr->ProtocolId != SMB2_PROTO_NUMBER)
52 cifs_dbg(VFS, "Bad protocol string signature header %x\n",
53 *(unsigned int *) hdr->ProtocolId);
54 if (mid != hdr->MessageId)
55 cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
56 mid, hdr->MessageId);
57 }
58 cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", hdr->MessageId);
59 return 1;
60 }
61
62 /*
63 * The following table defines the expected "StructureSize" of SMB2 responses
64 * in order by SMB2 command. This is similar to "wct" in SMB/CIFS responses.
65 *
66 * Note that commands are defined in smb2pdu.h in le16 but the array below is
67 * indexed by command in host byte order
68 */
69 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
70 /* SMB2_NEGOTIATE */ __constant_cpu_to_le16(65),
71 /* SMB2_SESSION_SETUP */ __constant_cpu_to_le16(9),
72 /* SMB2_LOGOFF */ __constant_cpu_to_le16(4),
73 /* SMB2_TREE_CONNECT */ __constant_cpu_to_le16(16),
74 /* SMB2_TREE_DISCONNECT */ __constant_cpu_to_le16(4),
75 /* SMB2_CREATE */ __constant_cpu_to_le16(89),
76 /* SMB2_CLOSE */ __constant_cpu_to_le16(60),
77 /* SMB2_FLUSH */ __constant_cpu_to_le16(4),
78 /* SMB2_READ */ __constant_cpu_to_le16(17),
79 /* SMB2_WRITE */ __constant_cpu_to_le16(17),
80 /* SMB2_LOCK */ __constant_cpu_to_le16(4),
81 /* SMB2_IOCTL */ __constant_cpu_to_le16(49),
82 /* BB CHECK this ... not listed in documentation */
83 /* SMB2_CANCEL */ __constant_cpu_to_le16(0),
84 /* SMB2_ECHO */ __constant_cpu_to_le16(4),
85 /* SMB2_QUERY_DIRECTORY */ __constant_cpu_to_le16(9),
86 /* SMB2_CHANGE_NOTIFY */ __constant_cpu_to_le16(9),
87 /* SMB2_QUERY_INFO */ __constant_cpu_to_le16(9),
88 /* SMB2_SET_INFO */ __constant_cpu_to_le16(2),
89 /* BB FIXME can also be 44 for lease break */
90 /* SMB2_OPLOCK_BREAK */ __constant_cpu_to_le16(24)
91 };
92
93 int
94 smb2_check_message(char *buf, unsigned int length)
95 {
96 struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
97 struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
98 __u64 mid = hdr->MessageId;
99 __u32 len = get_rfc1002_length(buf);
100 __u32 clc_len; /* calculated length */
101 int command;
102
103 /* BB disable following printk later */
104 cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n",
105 __func__, length, len);
106
107 /*
108 * Add function to do table lookup of StructureSize by command
109 * ie Validate the wct via smb2_struct_sizes table above
110 */
111
112 if (length < sizeof(struct smb2_pdu)) {
113 if ((length >= sizeof(struct smb2_hdr)) && (hdr->Status != 0)) {
114 pdu->StructureSize2 = 0;
115 /*
116 * As with SMB/CIFS, on some error cases servers may
117 * not return wct properly
118 */
119 return 0;
120 } else {
121 cifs_dbg(VFS, "Length less than SMB header size\n");
122 }
123 return 1;
124 }
125 if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
126 cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
127 mid);
128 return 1;
129 }
130
131 if (check_smb2_hdr(hdr, mid))
132 return 1;
133
134 if (hdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
135 cifs_dbg(VFS, "Illegal structure size %u\n",
136 le16_to_cpu(hdr->StructureSize));
137 return 1;
138 }
139
140 command = le16_to_cpu(hdr->Command);
141 if (command >= NUMBER_OF_SMB2_COMMANDS) {
142 cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
143 return 1;
144 }
145
146 if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
147 if (command != SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0 ||
148 pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
149 /* error packets have 9 byte structure size */
150 cifs_dbg(VFS, "Illegal response size %u for command %d\n",
151 le16_to_cpu(pdu->StructureSize2), command);
152 return 1;
153 } else if (command == SMB2_OPLOCK_BREAK_HE && (hdr->Status == 0)
154 && (le16_to_cpu(pdu->StructureSize2) != 44)
155 && (le16_to_cpu(pdu->StructureSize2) != 36)) {
156 /* special case for SMB2.1 lease break message */
157 cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
158 le16_to_cpu(pdu->StructureSize2));
159 return 1;
160 }
161 }
162
163 if (4 + len != length) {
164 cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
165 length, 4 + len, mid);
166 return 1;
167 }
168
169 clc_len = smb2_calc_size(hdr);
170
171 if (4 + len != clc_len) {
172 cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
173 clc_len, 4 + len, mid);
174 /* Windows 7 server returns 24 bytes more */
175 if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
176 return 0;
177 /* server can return one byte more */
178 if (clc_len == 4 + len + 1)
179 return 0;
180 return 1;
181 }
182 return 0;
183 }
184
185 /*
186 * The size of the variable area depends on the offset and length fields
187 * located in different fields for various SMB2 responses. SMB2 responses
188 * with no variable length info, show an offset of zero for the offset field.
189 */
190 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
191 /* SMB2_NEGOTIATE */ true,
192 /* SMB2_SESSION_SETUP */ true,
193 /* SMB2_LOGOFF */ false,
194 /* SMB2_TREE_CONNECT */ false,
195 /* SMB2_TREE_DISCONNECT */ false,
196 /* SMB2_CREATE */ true,
197 /* SMB2_CLOSE */ false,
198 /* SMB2_FLUSH */ false,
199 /* SMB2_READ */ true,
200 /* SMB2_WRITE */ false,
201 /* SMB2_LOCK */ false,
202 /* SMB2_IOCTL */ true,
203 /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
204 /* SMB2_ECHO */ false,
205 /* SMB2_QUERY_DIRECTORY */ true,
206 /* SMB2_CHANGE_NOTIFY */ true,
207 /* SMB2_QUERY_INFO */ true,
208 /* SMB2_SET_INFO */ false,
209 /* SMB2_OPLOCK_BREAK */ false
210 };
211
212 /*
213 * Returns the pointer to the beginning of the data area. Length of the data
214 * area and the offset to it (from the beginning of the smb are also returned.
215 */
216 char *
217 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
218 {
219 *off = 0;
220 *len = 0;
221
222 /* error responses do not have data area */
223 if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
224 (((struct smb2_err_rsp *)hdr)->StructureSize) ==
225 SMB2_ERROR_STRUCTURE_SIZE2)
226 return NULL;
227
228 /*
229 * Following commands have data areas so we have to get the location
230 * of the data buffer offset and data buffer length for the particular
231 * command.
232 */
233 switch (hdr->Command) {
234 case SMB2_NEGOTIATE:
235 *off = le16_to_cpu(
236 ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
237 *len = le16_to_cpu(
238 ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
239 break;
240 case SMB2_SESSION_SETUP:
241 *off = le16_to_cpu(
242 ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
243 *len = le16_to_cpu(
244 ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
245 break;
246 case SMB2_CREATE:
247 *off = le32_to_cpu(
248 ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
249 *len = le32_to_cpu(
250 ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
251 break;
252 case SMB2_QUERY_INFO:
253 *off = le16_to_cpu(
254 ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
255 *len = le32_to_cpu(
256 ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
257 break;
258 case SMB2_READ:
259 *off = ((struct smb2_read_rsp *)hdr)->DataOffset;
260 *len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
261 break;
262 case SMB2_QUERY_DIRECTORY:
263 *off = le16_to_cpu(
264 ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
265 *len = le32_to_cpu(
266 ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
267 break;
268 case SMB2_IOCTL:
269 case SMB2_CHANGE_NOTIFY:
270 default:
271 /* BB FIXME for unimplemented cases above */
272 cifs_dbg(VFS, "no length check for command\n");
273 break;
274 }
275
276 /*
277 * Invalid length or offset probably means data area is invalid, but
278 * we have little choice but to ignore the data area in this case.
279 */
280 if (*off > 4096) {
281 cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
282 *len = 0;
283 *off = 0;
284 } else if (*off < 0) {
285 cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
286 *off);
287 *off = 0;
288 *len = 0;
289 } else if (*len < 0) {
290 cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
291 *len);
292 *len = 0;
293 } else if (*len > 128 * 1024) {
294 cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
295 *len = 0;
296 }
297
298 /* return pointer to beginning of data area, ie offset from SMB start */
299 if ((*off != 0) && (*len != 0))
300 return hdr->ProtocolId + *off;
301 else
302 return NULL;
303 }
304
305 /*
306 * Calculate the size of the SMB message based on the fixed header
307 * portion, the number of word parameters and the data portion of the message.
308 */
309 unsigned int
310 smb2_calc_size(void *buf)
311 {
312 struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
313 struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
314 int offset; /* the offset from the beginning of SMB to data area */
315 int data_length; /* the length of the variable length data area */
316 /* Structure Size has already been checked to make sure it is 64 */
317 int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);
318
319 /*
320 * StructureSize2, ie length of fixed parameter area has already
321 * been checked to make sure it is the correct length.
322 */
323 len += le16_to_cpu(pdu->StructureSize2);
324
325 if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
326 goto calc_size_exit;
327
328 smb2_get_data_area_len(&offset, &data_length, hdr);
329 cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
330
331 if (data_length > 0) {
332 /*
333 * Check to make sure that data area begins after fixed area,
334 * Note that last byte of the fixed area is part of data area
335 * for some commands, typically those with odd StructureSize,
336 * so we must add one to the calculation (and 4 to account for
337 * the size of the RFC1001 hdr.
338 */
339 if (offset + 4 + 1 < len) {
340 cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
341 offset + 4 + 1, len);
342 data_length = 0;
343 } else {
344 len = 4 + offset + data_length;
345 }
346 }
347 calc_size_exit:
348 cifs_dbg(FYI, "SMB2 len %d\n", len);
349 return len;
350 }
351
352 /* Note: caller must free return buffer */
353 __le16 *
354 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
355 {
356 int len;
357 const char *start_of_path;
358 __le16 *to;
359
360 /* Windows doesn't allow paths beginning with \ */
361 if (from[0] == '\\')
362 start_of_path = from + 1;
363 else
364 start_of_path = from;
365 to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
366 cifs_sb->local_nls,
367 cifs_sb->mnt_cifs_flags &
368 CIFS_MOUNT_MAP_SPECIAL_CHR);
369 return to;
370 }
371
372 __le32
373 smb2_get_lease_state(struct cifsInodeInfo *cinode)
374 {
375 if (cinode->clientCanCacheAll)
376 return SMB2_LEASE_WRITE_CACHING | SMB2_LEASE_READ_CACHING;
377 else if (cinode->clientCanCacheRead)
378 return SMB2_LEASE_READ_CACHING;
379 return 0;
380 }
381
382 __u8 smb2_map_lease_to_oplock(__le32 lease_state)
383 {
384 if (lease_state & SMB2_LEASE_WRITE_CACHING) {
385 if (lease_state & SMB2_LEASE_HANDLE_CACHING)
386 return SMB2_OPLOCK_LEVEL_BATCH;
387 else
388 return SMB2_OPLOCK_LEVEL_EXCLUSIVE;
389 } else if (lease_state & SMB2_LEASE_READ_CACHING)
390 return SMB2_OPLOCK_LEVEL_II;
391 return 0;
392 }
393
394 struct smb2_lease_break_work {
395 struct work_struct lease_break;
396 struct tcon_link *tlink;
397 __u8 lease_key[16];
398 __le32 lease_state;
399 };
400
401 static void
402 cifs_ses_oplock_break(struct work_struct *work)
403 {
404 struct smb2_lease_break_work *lw = container_of(work,
405 struct smb2_lease_break_work, lease_break);
406 int rc;
407
408 rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
409 lw->lease_state);
410 cifs_dbg(FYI, "Lease release rc %d\n", rc);
411 cifs_put_tlink(lw->tlink);
412 kfree(lw);
413 }
414
415 static bool
416 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
417 {
418 struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
419 struct list_head *tmp, *tmp1, *tmp2;
420 struct cifs_ses *ses;
421 struct cifs_tcon *tcon;
422 struct cifsInodeInfo *cinode;
423 struct cifsFileInfo *cfile;
424 struct cifs_pending_open *open;
425 struct smb2_lease_break_work *lw;
426 bool found;
427 int ack_req = le32_to_cpu(rsp->Flags &
428 SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
429
430 lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
431 if (!lw)
432 return false;
433
434 INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
435 lw->lease_state = rsp->NewLeaseState;
436
437 cifs_dbg(FYI, "Checking for lease break\n");
438
439 /* look up tcon based on tid & uid */
440 spin_lock(&cifs_tcp_ses_lock);
441 list_for_each(tmp, &server->smb_ses_list) {
442 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
443
444 spin_lock(&cifs_file_list_lock);
445 list_for_each(tmp1, &ses->tcon_list) {
446 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
447
448 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
449 list_for_each(tmp2, &tcon->openFileList) {
450 cfile = list_entry(tmp2, struct cifsFileInfo,
451 tlist);
452 cinode = CIFS_I(cfile->dentry->d_inode);
453
454 if (memcmp(cinode->lease_key, rsp->LeaseKey,
455 SMB2_LEASE_KEY_SIZE))
456 continue;
457
458 cifs_dbg(FYI, "found in the open list\n");
459 cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
460 le32_to_cpu(rsp->NewLeaseState));
461
462 smb2_set_oplock_level(cinode,
463 smb2_map_lease_to_oplock(rsp->NewLeaseState));
464
465 if (ack_req)
466 cfile->oplock_break_cancelled = false;
467 else
468 cfile->oplock_break_cancelled = true;
469
470 queue_work(cifsiod_wq, &cfile->oplock_break);
471
472 spin_unlock(&cifs_file_list_lock);
473 spin_unlock(&cifs_tcp_ses_lock);
474 return true;
475 }
476
477 found = false;
478 list_for_each_entry(open, &tcon->pending_opens, olist) {
479 if (memcmp(open->lease_key, rsp->LeaseKey,
480 SMB2_LEASE_KEY_SIZE))
481 continue;
482
483 if (!found && ack_req) {
484 found = true;
485 memcpy(lw->lease_key, open->lease_key,
486 SMB2_LEASE_KEY_SIZE);
487 lw->tlink = cifs_get_tlink(open->tlink);
488 queue_work(cifsiod_wq,
489 &lw->lease_break);
490 }
491
492 cifs_dbg(FYI, "found in the pending open list\n");
493 cifs_dbg(FYI, "lease key match, lease break 0x%d\n",
494 le32_to_cpu(rsp->NewLeaseState));
495
496 open->oplock =
497 smb2_map_lease_to_oplock(rsp->NewLeaseState);
498 }
499 if (found) {
500 spin_unlock(&cifs_file_list_lock);
501 spin_unlock(&cifs_tcp_ses_lock);
502 return true;
503 }
504 }
505 spin_unlock(&cifs_file_list_lock);
506 }
507 spin_unlock(&cifs_tcp_ses_lock);
508 kfree(lw);
509 cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
510 return false;
511 }
512
513 bool
514 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
515 {
516 struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
517 struct list_head *tmp, *tmp1, *tmp2;
518 struct cifs_ses *ses;
519 struct cifs_tcon *tcon;
520 struct cifsInodeInfo *cinode;
521 struct cifsFileInfo *cfile;
522
523 cifs_dbg(FYI, "Checking for oplock break\n");
524
525 if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
526 return false;
527
528 if (rsp->StructureSize !=
529 smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
530 if (le16_to_cpu(rsp->StructureSize) == 44)
531 return smb2_is_valid_lease_break(buffer, server);
532 else
533 return false;
534 }
535
536 cifs_dbg(FYI, "oplock level 0x%d\n", rsp->OplockLevel);
537
538 /* look up tcon based on tid & uid */
539 spin_lock(&cifs_tcp_ses_lock);
540 list_for_each(tmp, &server->smb_ses_list) {
541 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
542 list_for_each(tmp1, &ses->tcon_list) {
543 tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
544
545 cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
546 spin_lock(&cifs_file_list_lock);
547 list_for_each(tmp2, &tcon->openFileList) {
548 cfile = list_entry(tmp2, struct cifsFileInfo,
549 tlist);
550 if (rsp->PersistentFid !=
551 cfile->fid.persistent_fid ||
552 rsp->VolatileFid !=
553 cfile->fid.volatile_fid)
554 continue;
555
556 cifs_dbg(FYI, "file id match, oplock break\n");
557 cinode = CIFS_I(cfile->dentry->d_inode);
558
559 if (!cinode->clientCanCacheAll &&
560 rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
561 cfile->oplock_break_cancelled = true;
562 else
563 cfile->oplock_break_cancelled = false;
564
565 smb2_set_oplock_level(cinode,
566 rsp->OplockLevel ? SMB2_OPLOCK_LEVEL_II : 0);
567
568 queue_work(cifsiod_wq, &cfile->oplock_break);
569
570 spin_unlock(&cifs_file_list_lock);
571 spin_unlock(&cifs_tcp_ses_lock);
572 return true;
573 }
574 spin_unlock(&cifs_file_list_lock);
575 spin_unlock(&cifs_tcp_ses_lock);
576 cifs_dbg(FYI, "No matching file for oplock break\n");
577 return true;
578 }
579 }
580 spin_unlock(&cifs_tcp_ses_lock);
581 cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
582 return false;
583 }
Linus' kernel tree