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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
check_smb2_hdr(struct smb2_hdr * hdr,__u64 mid)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
smb2_check_message(char * buf,unsigned int length)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 		/* create failed on symlink */
175 		if (command == SMB2_CREATE_HE &&
176 		    hdr->Status == STATUS_STOPPED_ON_SYMLINK)
177 			return 0;
178 		/* Windows 7 server returns 24 bytes more */
179 		if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
180 			return 0;
181 		/* server can return one byte more due to implied bcc[0] */
182 		if (clc_len == 4 + len + 1)
183 			return 0;
184 
185 		/*
186 		 * MacOS server pads after SMB2.1 write response with 3 bytes
187 		 * of junk. Other servers match RFC1001 len to actual
188 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
189 		 * Log the server error (once), but allow it and continue
190 		 * since the frame is parseable.
191 		 */
192 		if (clc_len < 4 /* RFC1001 header size */ + len) {
193 			printk_once(KERN_WARNING
194 				"SMB2 server sent bad RFC1001 len %d not %d\n",
195 				len, clc_len - 4);
196 			return 0;
197 		}
198 
199 		return 1;
200 	}
201 	return 0;
202 }
203 
204 /*
205  * The size of the variable area depends on the offset and length fields
206  * located in different fields for various SMB2 responses. SMB2 responses
207  * with no variable length info, show an offset of zero for the offset field.
208  */
209 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
210 	/* SMB2_NEGOTIATE */ true,
211 	/* SMB2_SESSION_SETUP */ true,
212 	/* SMB2_LOGOFF */ false,
213 	/* SMB2_TREE_CONNECT */	false,
214 	/* SMB2_TREE_DISCONNECT */ false,
215 	/* SMB2_CREATE */ true,
216 	/* SMB2_CLOSE */ false,
217 	/* SMB2_FLUSH */ false,
218 	/* SMB2_READ */	true,
219 	/* SMB2_WRITE */ false,
220 	/* SMB2_LOCK */	false,
221 	/* SMB2_IOCTL */ true,
222 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
223 	/* SMB2_ECHO */ false,
224 	/* SMB2_QUERY_DIRECTORY */ true,
225 	/* SMB2_CHANGE_NOTIFY */ true,
226 	/* SMB2_QUERY_INFO */ true,
227 	/* SMB2_SET_INFO */ false,
228 	/* SMB2_OPLOCK_BREAK */ false
229 };
230 
231 /*
232  * Returns the pointer to the beginning of the data area. Length of the data
233  * area and the offset to it (from the beginning of the smb are also returned.
234  */
235 char *
smb2_get_data_area_len(int * off,int * len,struct smb2_hdr * hdr)236 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
237 {
238 	*off = 0;
239 	*len = 0;
240 
241 	/* error responses do not have data area */
242 	if (hdr->Status && hdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
243 	    (((struct smb2_err_rsp *)hdr)->StructureSize) ==
244 						SMB2_ERROR_STRUCTURE_SIZE2)
245 		return NULL;
246 
247 	/*
248 	 * Following commands have data areas so we have to get the location
249 	 * of the data buffer offset and data buffer length for the particular
250 	 * command.
251 	 */
252 	switch (hdr->Command) {
253 	case SMB2_NEGOTIATE:
254 		*off = le16_to_cpu(
255 		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
256 		*len = le16_to_cpu(
257 		    ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
258 		break;
259 	case SMB2_SESSION_SETUP:
260 		*off = le16_to_cpu(
261 		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
262 		*len = le16_to_cpu(
263 		    ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
264 		break;
265 	case SMB2_CREATE:
266 		*off = le32_to_cpu(
267 		    ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
268 		*len = le32_to_cpu(
269 		    ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
270 		break;
271 	case SMB2_QUERY_INFO:
272 		*off = le16_to_cpu(
273 		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
274 		*len = le32_to_cpu(
275 		    ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
276 		break;
277 	case SMB2_READ:
278 		*off = ((struct smb2_read_rsp *)hdr)->DataOffset;
279 		*len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
280 		break;
281 	case SMB2_QUERY_DIRECTORY:
282 		*off = le16_to_cpu(
283 		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
284 		*len = le32_to_cpu(
285 		  ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
286 		break;
287 	case SMB2_IOCTL:
288 		*off = le32_to_cpu(
289 		  ((struct smb2_ioctl_rsp *)hdr)->OutputOffset);
290 		*len = le32_to_cpu(((struct smb2_ioctl_rsp *)hdr)->OutputCount);
291 		break;
292 	case SMB2_CHANGE_NOTIFY:
293 	default:
294 		/* BB FIXME for unimplemented cases above */
295 		cifs_dbg(VFS, "no length check for command\n");
296 		break;
297 	}
298 
299 	/*
300 	 * Invalid length or offset probably means data area is invalid, but
301 	 * we have little choice but to ignore the data area in this case.
302 	 */
303 	if (*off > 4096) {
304 		cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
305 		*len = 0;
306 		*off = 0;
307 	} else if (*off < 0) {
308 		cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
309 			 *off);
310 		*off = 0;
311 		*len = 0;
312 	} else if (*len < 0) {
313 		cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
314 			 *len);
315 		*len = 0;
316 	} else if (*len > 128 * 1024) {
317 		cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
318 		*len = 0;
319 	}
320 
321 	/* return pointer to beginning of data area, ie offset from SMB start */
322 	if ((*off != 0) && (*len != 0))
323 		return hdr->ProtocolId + *off;
324 	else
325 		return NULL;
326 }
327 
328 /*
329  * Calculate the size of the SMB message based on the fixed header
330  * portion, the number of word parameters and the data portion of the message.
331  */
332 unsigned int
smb2_calc_size(void * buf)333 smb2_calc_size(void *buf)
334 {
335 	struct smb2_hdr *hdr = (struct smb2_hdr *)buf;
336 	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
337 	int offset; /* the offset from the beginning of SMB to data area */
338 	int data_length; /* the length of the variable length data area */
339 	/* Structure Size has already been checked to make sure it is 64 */
340 	int len = 4 + le16_to_cpu(pdu->hdr.StructureSize);
341 
342 	/*
343 	 * StructureSize2, ie length of fixed parameter area has already
344 	 * been checked to make sure it is the correct length.
345 	 */
346 	len += le16_to_cpu(pdu->StructureSize2);
347 
348 	if (has_smb2_data_area[le16_to_cpu(hdr->Command)] == false)
349 		goto calc_size_exit;
350 
351 	smb2_get_data_area_len(&offset, &data_length, hdr);
352 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
353 
354 	if (data_length > 0) {
355 		/*
356 		 * Check to make sure that data area begins after fixed area,
357 		 * Note that last byte of the fixed area is part of data area
358 		 * for some commands, typically those with odd StructureSize,
359 		 * so we must add one to the calculation (and 4 to account for
360 		 * the size of the RFC1001 hdr.
361 		 */
362 		if (offset + 4 + 1 < len) {
363 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
364 				 offset + 4 + 1, len);
365 			data_length = 0;
366 		} else {
367 			len = 4 + offset + data_length;
368 		}
369 	}
370 calc_size_exit:
371 	cifs_dbg(FYI, "SMB2 len %d\n", len);
372 	return len;
373 }
374 
375 /* Note: caller must free return buffer */
376 __le16 *
cifs_convert_path_to_utf16(const char * from,struct cifs_sb_info * cifs_sb)377 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
378 {
379 	int len;
380 	const char *start_of_path;
381 	__le16 *to;
382 	int map_type;
383 
384 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
385 		map_type = SFM_MAP_UNI_RSVD;
386 	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
387 		map_type = SFU_MAP_UNI_RSVD;
388 	else
389 		map_type = NO_MAP_UNI_RSVD;
390 
391 	/* Windows doesn't allow paths beginning with \ */
392 	if (from[0] == '\\')
393 		start_of_path = from + 1;
394 	else
395 		start_of_path = from;
396 	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
397 				   cifs_sb->local_nls, map_type);
398 	return to;
399 }
400 
401 __le32
smb2_get_lease_state(struct cifsInodeInfo * cinode)402 smb2_get_lease_state(struct cifsInodeInfo *cinode)
403 {
404 	__le32 lease = 0;
405 
406 	if (CIFS_CACHE_WRITE(cinode))
407 		lease |= SMB2_LEASE_WRITE_CACHING;
408 	if (CIFS_CACHE_HANDLE(cinode))
409 		lease |= SMB2_LEASE_HANDLE_CACHING;
410 	if (CIFS_CACHE_READ(cinode))
411 		lease |= SMB2_LEASE_READ_CACHING;
412 	return lease;
413 }
414 
415 struct smb2_lease_break_work {
416 	struct work_struct lease_break;
417 	struct tcon_link *tlink;
418 	__u8 lease_key[16];
419 	__le32 lease_state;
420 };
421 
422 static void
cifs_ses_oplock_break(struct work_struct * work)423 cifs_ses_oplock_break(struct work_struct *work)
424 {
425 	struct smb2_lease_break_work *lw = container_of(work,
426 				struct smb2_lease_break_work, lease_break);
427 	int rc;
428 
429 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
430 			      lw->lease_state);
431 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
432 	cifs_put_tlink(lw->tlink);
433 	kfree(lw);
434 }
435 
436 static bool
smb2_tcon_has_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp,struct smb2_lease_break_work * lw)437 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
438 		    struct smb2_lease_break_work *lw)
439 {
440 	bool found;
441 	__u8 lease_state;
442 	struct list_head *tmp;
443 	struct cifsFileInfo *cfile;
444 	struct TCP_Server_Info *server = tcon->ses->server;
445 	struct cifs_pending_open *open;
446 	struct cifsInodeInfo *cinode;
447 	int ack_req = le32_to_cpu(rsp->Flags &
448 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
449 
450 	lease_state = le32_to_cpu(rsp->NewLeaseState);
451 
452 	list_for_each(tmp, &tcon->openFileList) {
453 		cfile = list_entry(tmp, struct cifsFileInfo, tlist);
454 		cinode = CIFS_I(cfile->dentry->d_inode);
455 
456 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
457 							SMB2_LEASE_KEY_SIZE))
458 			continue;
459 
460 		cifs_dbg(FYI, "found in the open list\n");
461 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
462 			 le32_to_cpu(rsp->NewLeaseState));
463 
464 		server->ops->set_oplock_level(cinode, lease_state, 0, NULL);
465 
466 		if (ack_req)
467 			cfile->oplock_break_cancelled = false;
468 		else
469 			cfile->oplock_break_cancelled = true;
470 
471 		queue_work(cifsiod_wq, &cfile->oplock_break);
472 		kfree(lw);
473 		return true;
474 	}
475 
476 	found = false;
477 	list_for_each_entry(open, &tcon->pending_opens, olist) {
478 		if (memcmp(open->lease_key, rsp->LeaseKey,
479 			   SMB2_LEASE_KEY_SIZE))
480 			continue;
481 
482 		if (!found && ack_req) {
483 			found = true;
484 			memcpy(lw->lease_key, open->lease_key,
485 			       SMB2_LEASE_KEY_SIZE);
486 			lw->tlink = cifs_get_tlink(open->tlink);
487 			queue_work(cifsiod_wq, &lw->lease_break);
488 		}
489 
490 		cifs_dbg(FYI, "found in the pending open list\n");
491 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
492 			 le32_to_cpu(rsp->NewLeaseState));
493 
494 		open->oplock = lease_state;
495 	}
496 	return found;
497 }
498 
499 static bool
smb2_is_valid_lease_break(char * buffer)500 smb2_is_valid_lease_break(char *buffer)
501 {
502 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
503 	struct list_head *tmp, *tmp1, *tmp2;
504 	struct TCP_Server_Info *server;
505 	struct cifs_ses *ses;
506 	struct cifs_tcon *tcon;
507 	struct smb2_lease_break_work *lw;
508 
509 	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
510 	if (!lw)
511 		return false;
512 
513 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
514 	lw->lease_state = rsp->NewLeaseState;
515 
516 	cifs_dbg(FYI, "Checking for lease break\n");
517 
518 	/* look up tcon based on tid & uid */
519 	spin_lock(&cifs_tcp_ses_lock);
520 	list_for_each(tmp, &cifs_tcp_ses_list) {
521 		server = list_entry(tmp, struct TCP_Server_Info, tcp_ses_list);
522 
523 		list_for_each(tmp1, &server->smb_ses_list) {
524 			ses = list_entry(tmp1, struct cifs_ses, smb_ses_list);
525 
526 			spin_lock(&cifs_file_list_lock);
527 			list_for_each(tmp2, &ses->tcon_list) {
528 				tcon = list_entry(tmp2, struct cifs_tcon,
529 						  tcon_list);
530 				cifs_stats_inc(
531 				    &tcon->stats.cifs_stats.num_oplock_brks);
532 				if (smb2_tcon_has_lease(tcon, rsp, lw)) {
533 					spin_unlock(&cifs_file_list_lock);
534 					spin_unlock(&cifs_tcp_ses_lock);
535 					return true;
536 				}
537 			}
538 			spin_unlock(&cifs_file_list_lock);
539 		}
540 	}
541 	spin_unlock(&cifs_tcp_ses_lock);
542 	kfree(lw);
543 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
544 	return false;
545 }
546 
547 bool
smb2_is_valid_oplock_break(char * buffer,struct TCP_Server_Info * server)548 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
549 {
550 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
551 	struct list_head *tmp, *tmp1, *tmp2;
552 	struct cifs_ses *ses;
553 	struct cifs_tcon *tcon;
554 	struct cifsInodeInfo *cinode;
555 	struct cifsFileInfo *cfile;
556 
557 	cifs_dbg(FYI, "Checking for oplock break\n");
558 
559 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
560 		return false;
561 
562 	if (rsp->StructureSize !=
563 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
564 		if (le16_to_cpu(rsp->StructureSize) == 44)
565 			return smb2_is_valid_lease_break(buffer);
566 		else
567 			return false;
568 	}
569 
570 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
571 
572 	/* look up tcon based on tid & uid */
573 	spin_lock(&cifs_tcp_ses_lock);
574 	list_for_each(tmp, &server->smb_ses_list) {
575 		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
576 		list_for_each(tmp1, &ses->tcon_list) {
577 			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
578 
579 			cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
580 			spin_lock(&cifs_file_list_lock);
581 			list_for_each(tmp2, &tcon->openFileList) {
582 				cfile = list_entry(tmp2, struct cifsFileInfo,
583 						     tlist);
584 				if (rsp->PersistentFid !=
585 				    cfile->fid.persistent_fid ||
586 				    rsp->VolatileFid !=
587 				    cfile->fid.volatile_fid)
588 					continue;
589 
590 				cifs_dbg(FYI, "file id match, oplock break\n");
591 				cinode = CIFS_I(cfile->dentry->d_inode);
592 
593 				if (!CIFS_CACHE_WRITE(cinode) &&
594 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
595 					cfile->oplock_break_cancelled = true;
596 				else
597 					cfile->oplock_break_cancelled = false;
598 
599 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
600 					&cinode->flags);
601 
602 				/*
603 				 * Set flag if the server downgrades the oplock
604 				 * to L2 else clear.
605 				 */
606 				if (rsp->OplockLevel)
607 					set_bit(
608 					   CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
609 					   &cinode->flags);
610 				else
611 					clear_bit(
612 					   CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
613 					   &cinode->flags);
614 
615 				queue_work(cifsiod_wq, &cfile->oplock_break);
616 
617 				spin_unlock(&cifs_file_list_lock);
618 				spin_unlock(&cifs_tcp_ses_lock);
619 				return true;
620 			}
621 			spin_unlock(&cifs_file_list_lock);
622 			spin_unlock(&cifs_tcp_ses_lock);
623 			cifs_dbg(FYI, "No matching file for oplock break\n");
624 			return true;
625 		}
626 	}
627 	spin_unlock(&cifs_tcp_ses_lock);
628 	cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
629 	return false;
630 }
631 
632 void
smb2_cancelled_close_fid(struct work_struct * work)633 smb2_cancelled_close_fid(struct work_struct *work)
634 {
635 	struct close_cancelled_open *cancelled = container_of(work,
636 					struct close_cancelled_open, work);
637 
638 	cifs_dbg(VFS, "Close unmatched open\n");
639 
640 	SMB2_close(0, cancelled->tcon, cancelled->fid.persistent_fid,
641 		   cancelled->fid.volatile_fid);
642 	cifs_put_tcon(cancelled->tcon);
643 	kfree(cancelled);
644 }
645 
646 int
smb2_handle_cancelled_mid(char * buffer,struct TCP_Server_Info * server)647 smb2_handle_cancelled_mid(char *buffer, struct TCP_Server_Info *server)
648 {
649 	struct smb2_hdr *hdr = (struct smb2_hdr *)buffer;
650 	struct smb2_create_rsp *rsp = (struct smb2_create_rsp *)buffer;
651 	struct cifs_tcon *tcon;
652 	struct close_cancelled_open *cancelled;
653 
654 	if (hdr->Command != SMB2_CREATE || hdr->Status != STATUS_SUCCESS)
655 		return 0;
656 
657 	cancelled = kzalloc(sizeof(*cancelled), GFP_KERNEL);
658 	if (!cancelled)
659 		return -ENOMEM;
660 
661 	tcon = smb2_find_smb_tcon(server, hdr->SessionId, hdr->TreeId);
662 	if (!tcon) {
663 		kfree(cancelled);
664 		return -ENOENT;
665 	}
666 
667 	cancelled->fid.persistent_fid = rsp->PersistentFileId;
668 	cancelled->fid.volatile_fid = rsp->VolatileFileId;
669 	cancelled->tcon = tcon;
670 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
671 	queue_work(cifsiod_wq, &cancelled->work);
672 
673 	return 0;
674 }
675