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 #include "smb2glob.h"
32 
33 static int
check_smb2_hdr(struct smb2_sync_hdr * shdr,__u64 mid)34 check_smb2_hdr(struct smb2_sync_hdr *shdr, __u64 mid)
35 {
36 	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
37 
38 	/*
39 	 * Make sure that this really is an SMB, that it is a response,
40 	 * and that the message ids match.
41 	 */
42 	if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
43 	    (mid == wire_mid)) {
44 		if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
45 			return 0;
46 		else {
47 			/* only one valid case where server sends us request */
48 			if (shdr->Command == SMB2_OPLOCK_BREAK)
49 				return 0;
50 			else
51 				cifs_dbg(VFS, "Received Request not response\n");
52 		}
53 	} else { /* bad signature or mid */
54 		if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
55 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
56 				 le32_to_cpu(shdr->ProtocolId));
57 		if (mid != wire_mid)
58 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
59 				 mid, wire_mid);
60 	}
61 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
62 	return 1;
63 }
64 
65 /*
66  *  The following table defines the expected "StructureSize" of SMB2 responses
67  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
68  *
69  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
70  *  indexed by command in host byte order
71  */
72 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
73 	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
74 	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
75 	/* SMB2_LOGOFF */ cpu_to_le16(4),
76 	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
77 	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
78 	/* SMB2_CREATE */ cpu_to_le16(89),
79 	/* SMB2_CLOSE */ cpu_to_le16(60),
80 	/* SMB2_FLUSH */ cpu_to_le16(4),
81 	/* SMB2_READ */ cpu_to_le16(17),
82 	/* SMB2_WRITE */ cpu_to_le16(17),
83 	/* SMB2_LOCK */ cpu_to_le16(4),
84 	/* SMB2_IOCTL */ cpu_to_le16(49),
85 	/* BB CHECK this ... not listed in documentation */
86 	/* SMB2_CANCEL */ cpu_to_le16(0),
87 	/* SMB2_ECHO */ cpu_to_le16(4),
88 	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
89 	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
90 	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
91 	/* SMB2_SET_INFO */ cpu_to_le16(2),
92 	/* BB FIXME can also be 44 for lease break */
93 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
94 };
95 
get_neg_ctxt_len(struct smb2_sync_hdr * hdr,__u32 len,__u32 non_ctxlen)96 static __u32 get_neg_ctxt_len(struct smb2_sync_hdr *hdr, __u32 len,
97 			      __u32 non_ctxlen)
98 {
99 	__u16 neg_count;
100 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
101 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
102 
103 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
104 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
105 	if ((neg_count == 0) ||
106 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
107 		return 0;
108 
109 	/* Make sure that negotiate contexts start after gss security blob */
110 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
111 	if (nc_offset < non_ctxlen) {
112 		printk_once(KERN_WARNING "invalid negotiate context offset\n");
113 		return 0;
114 	}
115 	size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
116 
117 	/* Verify that at least minimal negotiate contexts fit within frame */
118 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
119 		printk_once(KERN_WARNING "negotiate context goes beyond end\n");
120 		return 0;
121 	}
122 
123 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
124 		len - nc_offset, size_of_pad_before_neg_ctxts);
125 
126 	/* length of negcontexts including pad from end of sec blob to them */
127 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
128 }
129 
130 int
smb2_check_message(char * buf,unsigned int len,struct TCP_Server_Info * srvr)131 smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr)
132 {
133 	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;
134 	struct smb2_sync_pdu *pdu = (struct smb2_sync_pdu *)shdr;
135 	__u64 mid;
136 	__u32 clc_len;  /* calculated length */
137 	int command;
138 	int pdu_size = sizeof(struct smb2_sync_pdu);
139 	int hdr_size = sizeof(struct smb2_sync_hdr);
140 
141 	/*
142 	 * Add function to do table lookup of StructureSize by command
143 	 * ie Validate the wct via smb2_struct_sizes table above
144 	 */
145 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
146 		struct smb2_transform_hdr *thdr =
147 			(struct smb2_transform_hdr *)buf;
148 		struct cifs_ses *ses = NULL;
149 		struct list_head *tmp;
150 
151 		/* decrypt frame now that it is completely read in */
152 		spin_lock(&cifs_tcp_ses_lock);
153 		list_for_each(tmp, &srvr->smb_ses_list) {
154 			ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
155 			if (ses->Suid == thdr->SessionId)
156 				break;
157 
158 			ses = NULL;
159 		}
160 		spin_unlock(&cifs_tcp_ses_lock);
161 		if (ses == NULL) {
162 			cifs_dbg(VFS, "no decryption - session id not found\n");
163 			return 1;
164 		}
165 	}
166 
167 	mid = le64_to_cpu(shdr->MessageId);
168 	if (len < pdu_size) {
169 		if ((len >= hdr_size)
170 		    && (shdr->Status != 0)) {
171 			pdu->StructureSize2 = 0;
172 			/*
173 			 * As with SMB/CIFS, on some error cases servers may
174 			 * not return wct properly
175 			 */
176 			return 0;
177 		} else {
178 			cifs_dbg(VFS, "Length less than SMB header size\n");
179 		}
180 		return 1;
181 	}
182 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
183 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
184 			 mid);
185 		return 1;
186 	}
187 
188 	if (check_smb2_hdr(shdr, mid))
189 		return 1;
190 
191 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
192 		cifs_dbg(VFS, "Illegal structure size %u\n",
193 			 le16_to_cpu(shdr->StructureSize));
194 		return 1;
195 	}
196 
197 	command = le16_to_cpu(shdr->Command);
198 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
199 		cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
200 		return 1;
201 	}
202 
203 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
204 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
205 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
206 			/* error packets have 9 byte structure size */
207 			cifs_dbg(VFS, "Illegal response size %u for command %d\n",
208 				 le16_to_cpu(pdu->StructureSize2), command);
209 			return 1;
210 		} else if (command == SMB2_OPLOCK_BREAK_HE
211 			   && (shdr->Status == 0)
212 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
213 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
214 			/* special case for SMB2.1 lease break message */
215 			cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
216 				 le16_to_cpu(pdu->StructureSize2));
217 			return 1;
218 		}
219 	}
220 
221 	clc_len = smb2_calc_size(buf, srvr);
222 
223 	if (shdr->Command == SMB2_NEGOTIATE)
224 		clc_len += get_neg_ctxt_len(shdr, len, clc_len);
225 
226 	if (len != clc_len) {
227 		cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
228 			 clc_len, len, mid);
229 		/* create failed on symlink */
230 		if (command == SMB2_CREATE_HE &&
231 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK)
232 			return 0;
233 		/* Windows 7 server returns 24 bytes more */
234 		if (clc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
235 			return 0;
236 		/* server can return one byte more due to implied bcc[0] */
237 		if (clc_len == len + 1)
238 			return 0;
239 
240 		/*
241 		 * Some windows servers (win2016) will pad also the final
242 		 * PDU in a compound to 8 bytes.
243 		 */
244 		if (((clc_len + 7) & ~7) == len)
245 			return 0;
246 
247 		/*
248 		 * MacOS server pads after SMB2.1 write response with 3 bytes
249 		 * of junk. Other servers match RFC1001 len to actual
250 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
251 		 * Some windows servers also pad up to 8 bytes when compounding.
252 		 * If pad is longer than eight bytes, log the server behavior
253 		 * (once), since may indicate a problem but allow it and continue
254 		 * since the frame is parseable.
255 		 */
256 		if (clc_len < len) {
257 			pr_warn_once(
258 			     "srv rsp padded more than expected. Length %d not %d for cmd:%d mid:%llu\n",
259 			     len, clc_len, command, mid);
260 			return 0;
261 		}
262 		pr_warn_once(
263 			"srv rsp too short, len %d not %d. cmd:%d mid:%llu\n",
264 			len, clc_len, command, mid);
265 
266 		return 1;
267 	}
268 	return 0;
269 }
270 
271 /*
272  * The size of the variable area depends on the offset and length fields
273  * located in different fields for various SMB2 responses. SMB2 responses
274  * with no variable length info, show an offset of zero for the offset field.
275  */
276 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
277 	/* SMB2_NEGOTIATE */ true,
278 	/* SMB2_SESSION_SETUP */ true,
279 	/* SMB2_LOGOFF */ false,
280 	/* SMB2_TREE_CONNECT */	false,
281 	/* SMB2_TREE_DISCONNECT */ false,
282 	/* SMB2_CREATE */ true,
283 	/* SMB2_CLOSE */ false,
284 	/* SMB2_FLUSH */ false,
285 	/* SMB2_READ */	true,
286 	/* SMB2_WRITE */ false,
287 	/* SMB2_LOCK */	false,
288 	/* SMB2_IOCTL */ true,
289 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
290 	/* SMB2_ECHO */ false,
291 	/* SMB2_QUERY_DIRECTORY */ true,
292 	/* SMB2_CHANGE_NOTIFY */ true,
293 	/* SMB2_QUERY_INFO */ true,
294 	/* SMB2_SET_INFO */ false,
295 	/* SMB2_OPLOCK_BREAK */ false
296 };
297 
298 /*
299  * Returns the pointer to the beginning of the data area. Length of the data
300  * area and the offset to it (from the beginning of the smb are also returned.
301  */
302 char *
smb2_get_data_area_len(int * off,int * len,struct smb2_sync_hdr * shdr)303 smb2_get_data_area_len(int *off, int *len, struct smb2_sync_hdr *shdr)
304 {
305 	*off = 0;
306 	*len = 0;
307 
308 	/* error responses do not have data area */
309 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
310 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
311 						SMB2_ERROR_STRUCTURE_SIZE2)
312 		return NULL;
313 
314 	/*
315 	 * Following commands have data areas so we have to get the location
316 	 * of the data buffer offset and data buffer length for the particular
317 	 * command.
318 	 */
319 	switch (shdr->Command) {
320 	case SMB2_NEGOTIATE:
321 		*off = le16_to_cpu(
322 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
323 		*len = le16_to_cpu(
324 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
325 		break;
326 	case SMB2_SESSION_SETUP:
327 		*off = le16_to_cpu(
328 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
329 		*len = le16_to_cpu(
330 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
331 		break;
332 	case SMB2_CREATE:
333 		*off = le32_to_cpu(
334 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
335 		*len = le32_to_cpu(
336 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
337 		break;
338 	case SMB2_QUERY_INFO:
339 		*off = le16_to_cpu(
340 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
341 		*len = le32_to_cpu(
342 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
343 		break;
344 	case SMB2_READ:
345 		/* TODO: is this a bug ? */
346 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
347 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
348 		break;
349 	case SMB2_QUERY_DIRECTORY:
350 		*off = le16_to_cpu(
351 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
352 		*len = le32_to_cpu(
353 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
354 		break;
355 	case SMB2_IOCTL:
356 		*off = le32_to_cpu(
357 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
358 		*len = le32_to_cpu(
359 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
360 		break;
361 	case SMB2_CHANGE_NOTIFY:
362 	default:
363 		/* BB FIXME for unimplemented cases above */
364 		cifs_dbg(VFS, "no length check for command\n");
365 		break;
366 	}
367 
368 	/*
369 	 * Invalid length or offset probably means data area is invalid, but
370 	 * we have little choice but to ignore the data area in this case.
371 	 */
372 	if (*off > 4096) {
373 		cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
374 		*len = 0;
375 		*off = 0;
376 	} else if (*off < 0) {
377 		cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
378 			 *off);
379 		*off = 0;
380 		*len = 0;
381 	} else if (*len < 0) {
382 		cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
383 			 *len);
384 		*len = 0;
385 	} else if (*len > 128 * 1024) {
386 		cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
387 		*len = 0;
388 	}
389 
390 	/* return pointer to beginning of data area, ie offset from SMB start */
391 	if ((*off != 0) && (*len != 0))
392 		return (char *)shdr + *off;
393 	else
394 		return NULL;
395 }
396 
397 /*
398  * Calculate the size of the SMB message based on the fixed header
399  * portion, the number of word parameters and the data portion of the message.
400  */
401 unsigned int
smb2_calc_size(void * buf,struct TCP_Server_Info * srvr)402 smb2_calc_size(void *buf, struct TCP_Server_Info *srvr)
403 {
404 	struct smb2_sync_pdu *pdu = (struct smb2_sync_pdu *)buf;
405 	struct smb2_sync_hdr *shdr = &pdu->sync_hdr;
406 	int offset; /* the offset from the beginning of SMB to data area */
407 	int data_length; /* the length of the variable length data area */
408 	/* Structure Size has already been checked to make sure it is 64 */
409 	int len = le16_to_cpu(shdr->StructureSize);
410 
411 	/*
412 	 * StructureSize2, ie length of fixed parameter area has already
413 	 * been checked to make sure it is the correct length.
414 	 */
415 	len += le16_to_cpu(pdu->StructureSize2);
416 
417 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
418 		goto calc_size_exit;
419 
420 	smb2_get_data_area_len(&offset, &data_length, shdr);
421 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
422 
423 	if (data_length > 0) {
424 		/*
425 		 * Check to make sure that data area begins after fixed area,
426 		 * Note that last byte of the fixed area is part of data area
427 		 * for some commands, typically those with odd StructureSize,
428 		 * so we must add one to the calculation.
429 		 */
430 		if (offset + 1 < len) {
431 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
432 				 offset + 1, len);
433 			data_length = 0;
434 		} else {
435 			len = offset + data_length;
436 		}
437 	}
438 calc_size_exit:
439 	cifs_dbg(FYI, "SMB2 len %d\n", len);
440 	return len;
441 }
442 
443 /* Note: caller must free return buffer */
444 __le16 *
cifs_convert_path_to_utf16(const char * from,struct cifs_sb_info * cifs_sb)445 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
446 {
447 	int len;
448 	const char *start_of_path;
449 	__le16 *to;
450 	int map_type;
451 
452 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
453 		map_type = SFM_MAP_UNI_RSVD;
454 	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
455 		map_type = SFU_MAP_UNI_RSVD;
456 	else
457 		map_type = NO_MAP_UNI_RSVD;
458 
459 	/* Windows doesn't allow paths beginning with \ */
460 	if (from[0] == '\\')
461 		start_of_path = from + 1;
462 
463 	/* SMB311 POSIX extensions paths do not include leading slash */
464 	else if (cifs_sb_master_tlink(cifs_sb) &&
465 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
466 		 (from[0] == '/')) {
467 		start_of_path = from + 1;
468 	} else
469 		start_of_path = from;
470 
471 	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
472 				   cifs_sb->local_nls, map_type);
473 	return to;
474 }
475 
476 __le32
smb2_get_lease_state(struct cifsInodeInfo * cinode)477 smb2_get_lease_state(struct cifsInodeInfo *cinode)
478 {
479 	__le32 lease = 0;
480 
481 	if (CIFS_CACHE_WRITE(cinode))
482 		lease |= SMB2_LEASE_WRITE_CACHING;
483 	if (CIFS_CACHE_HANDLE(cinode))
484 		lease |= SMB2_LEASE_HANDLE_CACHING;
485 	if (CIFS_CACHE_READ(cinode))
486 		lease |= SMB2_LEASE_READ_CACHING;
487 	return lease;
488 }
489 
490 struct smb2_lease_break_work {
491 	struct work_struct lease_break;
492 	struct tcon_link *tlink;
493 	__u8 lease_key[16];
494 	__le32 lease_state;
495 };
496 
497 static void
cifs_ses_oplock_break(struct work_struct * work)498 cifs_ses_oplock_break(struct work_struct *work)
499 {
500 	struct smb2_lease_break_work *lw = container_of(work,
501 				struct smb2_lease_break_work, lease_break);
502 	int rc = 0;
503 
504 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
505 			      lw->lease_state);
506 
507 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
508 	cifs_put_tlink(lw->tlink);
509 	kfree(lw);
510 }
511 
512 static void
smb2_queue_pending_open_break(struct tcon_link * tlink,__u8 * lease_key,__le32 new_lease_state)513 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
514 			      __le32 new_lease_state)
515 {
516 	struct smb2_lease_break_work *lw;
517 
518 	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
519 	if (!lw) {
520 		cifs_put_tlink(tlink);
521 		return;
522 	}
523 
524 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
525 	lw->tlink = tlink;
526 	lw->lease_state = new_lease_state;
527 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
528 	queue_work(cifsiod_wq, &lw->lease_break);
529 }
530 
531 static bool
smb2_tcon_has_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)532 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
533 {
534 	__u8 lease_state;
535 	struct list_head *tmp;
536 	struct cifsFileInfo *cfile;
537 	struct cifsInodeInfo *cinode;
538 	int ack_req = le32_to_cpu(rsp->Flags &
539 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
540 
541 	lease_state = le32_to_cpu(rsp->NewLeaseState);
542 
543 	list_for_each(tmp, &tcon->openFileList) {
544 		cfile = list_entry(tmp, struct cifsFileInfo, tlist);
545 		cinode = CIFS_I(d_inode(cfile->dentry));
546 
547 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
548 							SMB2_LEASE_KEY_SIZE))
549 			continue;
550 
551 		cifs_dbg(FYI, "found in the open list\n");
552 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
553 			 lease_state);
554 
555 		if (ack_req)
556 			cfile->oplock_break_cancelled = false;
557 		else
558 			cfile->oplock_break_cancelled = true;
559 
560 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
561 
562 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
563 		cfile->oplock_level = lease_state;
564 
565 		cifs_queue_oplock_break(cfile);
566 		return true;
567 	}
568 
569 	return false;
570 }
571 
572 static struct cifs_pending_open *
smb2_tcon_find_pending_open_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)573 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
574 				  struct smb2_lease_break *rsp)
575 {
576 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
577 	int ack_req = le32_to_cpu(rsp->Flags &
578 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
579 	struct cifs_pending_open *open;
580 	struct cifs_pending_open *found = NULL;
581 
582 	list_for_each_entry(open, &tcon->pending_opens, olist) {
583 		if (memcmp(open->lease_key, rsp->LeaseKey,
584 			   SMB2_LEASE_KEY_SIZE))
585 			continue;
586 
587 		if (!found && ack_req) {
588 			found = open;
589 		}
590 
591 		cifs_dbg(FYI, "found in the pending open list\n");
592 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
593 			 lease_state);
594 
595 		open->oplock = lease_state;
596 	}
597 
598 	return found;
599 }
600 
601 static bool
smb2_is_valid_lease_break(char * buffer)602 smb2_is_valid_lease_break(char *buffer)
603 {
604 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
605 	struct list_head *tmp, *tmp1, *tmp2;
606 	struct TCP_Server_Info *server;
607 	struct cifs_ses *ses;
608 	struct cifs_tcon *tcon;
609 	struct cifs_pending_open *open;
610 
611 	cifs_dbg(FYI, "Checking for lease break\n");
612 
613 	/* look up tcon based on tid & uid */
614 	spin_lock(&cifs_tcp_ses_lock);
615 	list_for_each(tmp, &cifs_tcp_ses_list) {
616 		server = list_entry(tmp, struct TCP_Server_Info, tcp_ses_list);
617 
618 		list_for_each(tmp1, &server->smb_ses_list) {
619 			ses = list_entry(tmp1, struct cifs_ses, smb_ses_list);
620 
621 			list_for_each(tmp2, &ses->tcon_list) {
622 				tcon = list_entry(tmp2, struct cifs_tcon,
623 						  tcon_list);
624 				spin_lock(&tcon->open_file_lock);
625 				cifs_stats_inc(
626 				    &tcon->stats.cifs_stats.num_oplock_brks);
627 				if (smb2_tcon_has_lease(tcon, rsp)) {
628 					spin_unlock(&tcon->open_file_lock);
629 					spin_unlock(&cifs_tcp_ses_lock);
630 					return true;
631 				}
632 				open = smb2_tcon_find_pending_open_lease(tcon,
633 									 rsp);
634 				if (open) {
635 					__u8 lease_key[SMB2_LEASE_KEY_SIZE];
636 					struct tcon_link *tlink;
637 
638 					tlink = cifs_get_tlink(open->tlink);
639 					memcpy(lease_key, open->lease_key,
640 					       SMB2_LEASE_KEY_SIZE);
641 					spin_unlock(&tcon->open_file_lock);
642 					spin_unlock(&cifs_tcp_ses_lock);
643 					smb2_queue_pending_open_break(tlink,
644 								      lease_key,
645 								      rsp->NewLeaseState);
646 					return true;
647 				}
648 				spin_unlock(&tcon->open_file_lock);
649 
650 				if (tcon->crfid.is_valid &&
651 				    !memcmp(rsp->LeaseKey,
652 					    tcon->crfid.fid->lease_key,
653 					    SMB2_LEASE_KEY_SIZE)) {
654 					INIT_WORK(&tcon->crfid.lease_break,
655 						  smb2_cached_lease_break);
656 					queue_work(cifsiod_wq,
657 						   &tcon->crfid.lease_break);
658 					spin_unlock(&cifs_tcp_ses_lock);
659 					return true;
660 				}
661 			}
662 		}
663 	}
664 	spin_unlock(&cifs_tcp_ses_lock);
665 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
666 	return false;
667 }
668 
669 bool
smb2_is_valid_oplock_break(char * buffer,struct TCP_Server_Info * server)670 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
671 {
672 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
673 	struct list_head *tmp, *tmp1, *tmp2;
674 	struct cifs_ses *ses;
675 	struct cifs_tcon *tcon;
676 	struct cifsInodeInfo *cinode;
677 	struct cifsFileInfo *cfile;
678 
679 	cifs_dbg(FYI, "Checking for oplock break\n");
680 
681 	if (rsp->sync_hdr.Command != SMB2_OPLOCK_BREAK)
682 		return false;
683 
684 	if (rsp->StructureSize !=
685 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
686 		if (le16_to_cpu(rsp->StructureSize) == 44)
687 			return smb2_is_valid_lease_break(buffer);
688 		else
689 			return false;
690 	}
691 
692 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
693 
694 	/* look up tcon based on tid & uid */
695 	spin_lock(&cifs_tcp_ses_lock);
696 	list_for_each(tmp, &server->smb_ses_list) {
697 		ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
698 
699 		list_for_each(tmp1, &ses->tcon_list) {
700 			tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
701 
702 			spin_lock(&tcon->open_file_lock);
703 			list_for_each(tmp2, &tcon->openFileList) {
704 				cfile = list_entry(tmp2, struct cifsFileInfo,
705 						     tlist);
706 				if (rsp->PersistentFid !=
707 				    cfile->fid.persistent_fid ||
708 				    rsp->VolatileFid !=
709 				    cfile->fid.volatile_fid)
710 					continue;
711 
712 				cifs_dbg(FYI, "file id match, oplock break\n");
713 				cifs_stats_inc(
714 				    &tcon->stats.cifs_stats.num_oplock_brks);
715 				cinode = CIFS_I(d_inode(cfile->dentry));
716 				spin_lock(&cfile->file_info_lock);
717 				if (!CIFS_CACHE_WRITE(cinode) &&
718 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
719 					cfile->oplock_break_cancelled = true;
720 				else
721 					cfile->oplock_break_cancelled = false;
722 
723 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
724 					&cinode->flags);
725 
726 				cfile->oplock_epoch = 0;
727 				cfile->oplock_level = rsp->OplockLevel;
728 
729 				spin_unlock(&cfile->file_info_lock);
730 
731 				cifs_queue_oplock_break(cfile);
732 
733 				spin_unlock(&tcon->open_file_lock);
734 				spin_unlock(&cifs_tcp_ses_lock);
735 				return true;
736 			}
737 			spin_unlock(&tcon->open_file_lock);
738 		}
739 	}
740 	spin_unlock(&cifs_tcp_ses_lock);
741 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
742 	return true;
743 }
744 
745 void
smb2_cancelled_close_fid(struct work_struct * work)746 smb2_cancelled_close_fid(struct work_struct *work)
747 {
748 	struct close_cancelled_open *cancelled = container_of(work,
749 					struct close_cancelled_open, work);
750 
751 	cifs_dbg(VFS, "Close unmatched open\n");
752 
753 	SMB2_close(0, cancelled->tcon, cancelled->fid.persistent_fid,
754 		   cancelled->fid.volatile_fid);
755 	cifs_put_tcon(cancelled->tcon);
756 	kfree(cancelled);
757 }
758 
759 /* Caller should already has an extra reference to @tcon */
760 static int
__smb2_handle_cancelled_close(struct cifs_tcon * tcon,__u64 persistent_fid,__u64 volatile_fid)761 __smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
762 			      __u64 volatile_fid)
763 {
764 	struct close_cancelled_open *cancelled;
765 
766 	cancelled = kzalloc(sizeof(*cancelled), GFP_ATOMIC);
767 	if (!cancelled)
768 		return -ENOMEM;
769 
770 	cancelled->fid.persistent_fid = persistent_fid;
771 	cancelled->fid.volatile_fid = volatile_fid;
772 	cancelled->tcon = tcon;
773 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
774 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
775 
776 	return 0;
777 }
778 
779 int
smb2_handle_cancelled_close(struct cifs_tcon * tcon,__u64 persistent_fid,__u64 volatile_fid)780 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
781 			    __u64 volatile_fid)
782 {
783 	int rc;
784 
785 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
786 	spin_lock(&cifs_tcp_ses_lock);
787 	tcon->tc_count++;
788 	spin_unlock(&cifs_tcp_ses_lock);
789 
790 	rc = __smb2_handle_cancelled_close(tcon, persistent_fid, volatile_fid);
791 	if (rc)
792 		cifs_put_tcon(tcon);
793 
794 	return rc;
795 }
796 
797 int
smb2_handle_cancelled_mid(char * buffer,struct TCP_Server_Info * server)798 smb2_handle_cancelled_mid(char *buffer, struct TCP_Server_Info *server)
799 {
800 	struct smb2_sync_hdr *sync_hdr = (struct smb2_sync_hdr *)buffer;
801 	struct smb2_create_rsp *rsp = (struct smb2_create_rsp *)buffer;
802 	struct cifs_tcon *tcon;
803 	int rc;
804 
805 	if (sync_hdr->Command != SMB2_CREATE ||
806 	    sync_hdr->Status != STATUS_SUCCESS)
807 		return 0;
808 
809 	tcon = smb2_find_smb_tcon(server, sync_hdr->SessionId,
810 				  sync_hdr->TreeId);
811 	if (!tcon)
812 		return -ENOENT;
813 
814 	rc = __smb2_handle_cancelled_close(tcon, rsp->PersistentFileId,
815 					   rsp->VolatileFileId);
816 	if (rc)
817 		cifs_put_tcon(tcon);
818 
819 	return rc;
820 }
821 
822 /**
823  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
824  *
825  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
826  * SMB2 header.
827  */
828 int
smb311_update_preauth_hash(struct cifs_ses * ses,struct kvec * iov,int nvec)829 smb311_update_preauth_hash(struct cifs_ses *ses, struct kvec *iov, int nvec)
830 {
831 	int i, rc;
832 	struct sdesc *d;
833 	struct smb2_sync_hdr *hdr;
834 
835 	if (ses->server->tcpStatus == CifsGood) {
836 		/* skip non smb311 connections */
837 		if (ses->server->dialect != SMB311_PROT_ID)
838 			return 0;
839 
840 		/* skip last sess setup response */
841 		hdr = (struct smb2_sync_hdr *)iov[0].iov_base;
842 		if (hdr->Flags & SMB2_FLAGS_SIGNED)
843 			return 0;
844 	}
845 
846 	rc = smb311_crypto_shash_allocate(ses->server);
847 	if (rc)
848 		return rc;
849 
850 	d = ses->server->secmech.sdescsha512;
851 	rc = crypto_shash_init(&d->shash);
852 	if (rc) {
853 		cifs_dbg(VFS, "%s: could not init sha512 shash\n", __func__);
854 		return rc;
855 	}
856 
857 	rc = crypto_shash_update(&d->shash, ses->preauth_sha_hash,
858 				 SMB2_PREAUTH_HASH_SIZE);
859 	if (rc) {
860 		cifs_dbg(VFS, "%s: could not update sha512 shash\n", __func__);
861 		return rc;
862 	}
863 
864 	for (i = 0; i < nvec; i++) {
865 		rc = crypto_shash_update(&d->shash,
866 					 iov[i].iov_base, iov[i].iov_len);
867 		if (rc) {
868 			cifs_dbg(VFS, "%s: could not update sha512 shash\n",
869 				 __func__);
870 			return rc;
871 		}
872 	}
873 
874 	rc = crypto_shash_final(&d->shash, ses->preauth_sha_hash);
875 	if (rc) {
876 		cifs_dbg(VFS, "%s: could not finalize sha512 shash\n",
877 			 __func__);
878 		return rc;
879 	}
880 
881 	return 0;
882 }
883