xref: /linux/fs/smb/client/smb2misc.c (revision a90e8608eb0ed93d31ac0feb055f77ce59512542)
1 // SPDX-License-Identifier: LGPL-2.1
2 /*
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  */
10 #include <linux/ctype.h>
11 #include "cifsglob.h"
12 #include "cifsproto.h"
13 #include "smb2proto.h"
14 #include "cifs_debug.h"
15 #include "cifs_unicode.h"
16 #include "smb2status.h"
17 #include "smb2glob.h"
18 #include "nterr.h"
19 #include "cached_dir.h"
20 
21 static int
22 check_smb2_hdr(struct smb2_hdr *shdr, __u64 mid)
23 {
24 	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
25 
26 	/*
27 	 * Make sure that this really is an SMB, that it is a response,
28 	 * and that the message ids match.
29 	 */
30 	if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
31 	    (mid == wire_mid)) {
32 		if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
33 			return 0;
34 		else {
35 			/* only one valid case where server sends us request */
36 			if (shdr->Command == SMB2_OPLOCK_BREAK)
37 				return 0;
38 			else
39 				cifs_dbg(VFS, "Received Request not response\n");
40 		}
41 	} else { /* bad signature or mid */
42 		if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
43 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
44 				 le32_to_cpu(shdr->ProtocolId));
45 		if (mid != wire_mid)
46 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
47 				 mid, wire_mid);
48 	}
49 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
50 	return 1;
51 }
52 
53 /*
54  *  The following table defines the expected "StructureSize" of SMB2 responses
55  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
56  *
57  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
58  *  indexed by command in host byte order
59  */
60 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
61 	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
62 	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
63 	/* SMB2_LOGOFF */ cpu_to_le16(4),
64 	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
65 	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
66 	/* SMB2_CREATE */ cpu_to_le16(89),
67 	/* SMB2_CLOSE */ cpu_to_le16(60),
68 	/* SMB2_FLUSH */ cpu_to_le16(4),
69 	/* SMB2_READ */ cpu_to_le16(17),
70 	/* SMB2_WRITE */ cpu_to_le16(17),
71 	/* SMB2_LOCK */ cpu_to_le16(4),
72 	/* SMB2_IOCTL */ cpu_to_le16(49),
73 	/* BB CHECK this ... not listed in documentation */
74 	/* SMB2_CANCEL */ cpu_to_le16(0),
75 	/* SMB2_ECHO */ cpu_to_le16(4),
76 	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
77 	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
78 	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
79 	/* SMB2_SET_INFO */ cpu_to_le16(2),
80 	/* BB FIXME can also be 44 for lease break */
81 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
82 };
83 
84 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_hdr) + sizeof(struct smb2_negotiate_rsp))
85 
86 static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len,
87 			      __u32 non_ctxlen)
88 {
89 	__u16 neg_count;
90 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
91 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
92 
93 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
94 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
95 	if ((neg_count == 0) ||
96 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
97 		return 0;
98 
99 	/*
100 	 * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
101 	 * which security mechanisms the server supports) make sure that
102 	 * the negotiate contexts start after it
103 	 */
104 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
105 	/*
106 	 * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
107 	 * and the latter is 1 byte bigger than the fix-sized area of the
108 	 * NEGOTIATE response
109 	 */
110 	if (nc_offset + 1 < non_ctxlen) {
111 		pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
112 		return 0;
113 	} else if (nc_offset + 1 == non_ctxlen) {
114 		cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
115 		size_of_pad_before_neg_ctxts = 0;
116 	} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
117 		/* has padding, but no SPNEGO blob */
118 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
119 	else
120 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
121 
122 	/* Verify that at least minimal negotiate contexts fit within frame */
123 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
124 		pr_warn_once("negotiate context goes beyond end\n");
125 		return 0;
126 	}
127 
128 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
129 		len - nc_offset, size_of_pad_before_neg_ctxts);
130 
131 	/* length of negcontexts including pad from end of sec blob to them */
132 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
133 }
134 
135 int
136 smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
137 {
138 	struct TCP_Server_Info *pserver;
139 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
140 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
141 	int hdr_size = sizeof(struct smb2_hdr);
142 	int pdu_size = sizeof(struct smb2_pdu);
143 	int command;
144 	__u32 calc_len; /* calculated length */
145 	__u64 mid;
146 
147 	/* If server is a channel, select the primary channel */
148 	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
149 
150 	/*
151 	 * Add function to do table lookup of StructureSize by command
152 	 * ie Validate the wct via smb2_struct_sizes table above
153 	 */
154 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
155 		struct smb2_transform_hdr *thdr =
156 			(struct smb2_transform_hdr *)buf;
157 		struct cifs_ses *ses = NULL;
158 		struct cifs_ses *iter;
159 
160 		/* decrypt frame now that it is completely read in */
161 		spin_lock(&cifs_tcp_ses_lock);
162 		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
163 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
164 				ses = iter;
165 				break;
166 			}
167 		}
168 		spin_unlock(&cifs_tcp_ses_lock);
169 		if (!ses) {
170 			cifs_dbg(VFS, "no decryption - session id not found\n");
171 			return 1;
172 		}
173 	}
174 
175 	mid = le64_to_cpu(shdr->MessageId);
176 	if (len < pdu_size) {
177 		if ((len >= hdr_size)
178 		    && (shdr->Status != 0)) {
179 			pdu->StructureSize2 = 0;
180 			/*
181 			 * As with SMB/CIFS, on some error cases servers may
182 			 * not return wct properly
183 			 */
184 			return 0;
185 		} else {
186 			cifs_dbg(VFS, "Length less than SMB header size\n");
187 		}
188 		return 1;
189 	}
190 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
191 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
192 			 mid);
193 		return 1;
194 	}
195 
196 	if (check_smb2_hdr(shdr, mid))
197 		return 1;
198 
199 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
200 		cifs_dbg(VFS, "Invalid structure size %u\n",
201 			 le16_to_cpu(shdr->StructureSize));
202 		return 1;
203 	}
204 
205 	command = le16_to_cpu(shdr->Command);
206 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
207 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
208 		return 1;
209 	}
210 
211 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
212 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
213 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
214 			/* error packets have 9 byte structure size */
215 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
216 				 le16_to_cpu(pdu->StructureSize2), command);
217 			return 1;
218 		} else if (command == SMB2_OPLOCK_BREAK_HE
219 			   && (shdr->Status == 0)
220 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
221 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
222 			/* special case for SMB2.1 lease break message */
223 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
224 				 le16_to_cpu(pdu->StructureSize2));
225 			return 1;
226 		}
227 	}
228 
229 	calc_len = smb2_calc_size(buf);
230 
231 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
232 	 * be 0, and not a real miscalculation */
233 	if (command == SMB2_IOCTL_HE && calc_len == 0)
234 		return 0;
235 
236 	if (command == SMB2_NEGOTIATE_HE)
237 		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
238 
239 	if (len != calc_len) {
240 		/* create failed on symlink */
241 		if (command == SMB2_CREATE_HE &&
242 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK)
243 			return 0;
244 		/* Windows 7 server returns 24 bytes more */
245 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
246 			return 0;
247 		/* server can return one byte more due to implied bcc[0] */
248 		if (calc_len == len + 1)
249 			return 0;
250 
251 		/*
252 		 * Some windows servers (win2016) will pad also the final
253 		 * PDU in a compound to 8 bytes.
254 		 */
255 		if (ALIGN(calc_len, 8) == len)
256 			return 0;
257 
258 		/*
259 		 * MacOS server pads after SMB2.1 write response with 3 bytes
260 		 * of junk. Other servers match RFC1001 len to actual
261 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
262 		 * Some windows servers also pad up to 8 bytes when compounding.
263 		 */
264 		if (calc_len < len)
265 			return 0;
266 
267 		/* Only log a message if len was really miscalculated */
268 		if (unlikely(cifsFYI))
269 			cifs_dbg(FYI, "Server response too short: calculated "
270 				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
271 				 calc_len, len, command, mid);
272 		else
273 			pr_warn("Server response too short: calculated length "
274 				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
275 				calc_len, len, command, mid);
276 
277 		return 1;
278 	}
279 	return 0;
280 }
281 
282 /*
283  * The size of the variable area depends on the offset and length fields
284  * located in different fields for various SMB2 responses. SMB2 responses
285  * with no variable length info, show an offset of zero for the offset field.
286  */
287 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
288 	/* SMB2_NEGOTIATE */ true,
289 	/* SMB2_SESSION_SETUP */ true,
290 	/* SMB2_LOGOFF */ false,
291 	/* SMB2_TREE_CONNECT */	false,
292 	/* SMB2_TREE_DISCONNECT */ false,
293 	/* SMB2_CREATE */ true,
294 	/* SMB2_CLOSE */ false,
295 	/* SMB2_FLUSH */ false,
296 	/* SMB2_READ */	true,
297 	/* SMB2_WRITE */ false,
298 	/* SMB2_LOCK */	false,
299 	/* SMB2_IOCTL */ true,
300 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
301 	/* SMB2_ECHO */ false,
302 	/* SMB2_QUERY_DIRECTORY */ true,
303 	/* SMB2_CHANGE_NOTIFY */ true,
304 	/* SMB2_QUERY_INFO */ true,
305 	/* SMB2_SET_INFO */ false,
306 	/* SMB2_OPLOCK_BREAK */ false
307 };
308 
309 /*
310  * Returns the pointer to the beginning of the data area. Length of the data
311  * area and the offset to it (from the beginning of the smb are also returned.
312  */
313 char *
314 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
315 {
316 	*off = 0;
317 	*len = 0;
318 
319 	/* error responses do not have data area */
320 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
321 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
322 						SMB2_ERROR_STRUCTURE_SIZE2_LE)
323 		return NULL;
324 
325 	/*
326 	 * Following commands have data areas so we have to get the location
327 	 * of the data buffer offset and data buffer length for the particular
328 	 * command.
329 	 */
330 	switch (shdr->Command) {
331 	case SMB2_NEGOTIATE:
332 		*off = le16_to_cpu(
333 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
334 		*len = le16_to_cpu(
335 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
336 		break;
337 	case SMB2_SESSION_SETUP:
338 		*off = le16_to_cpu(
339 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
340 		*len = le16_to_cpu(
341 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
342 		break;
343 	case SMB2_CREATE:
344 		*off = le32_to_cpu(
345 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
346 		*len = le32_to_cpu(
347 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
348 		break;
349 	case SMB2_QUERY_INFO:
350 		*off = le16_to_cpu(
351 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
352 		*len = le32_to_cpu(
353 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
354 		break;
355 	case SMB2_READ:
356 		/* TODO: is this a bug ? */
357 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
358 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
359 		break;
360 	case SMB2_QUERY_DIRECTORY:
361 		*off = le16_to_cpu(
362 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
363 		*len = le32_to_cpu(
364 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
365 		break;
366 	case SMB2_IOCTL:
367 		*off = le32_to_cpu(
368 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
369 		*len = le32_to_cpu(
370 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
371 		break;
372 	case SMB2_CHANGE_NOTIFY:
373 		*off = le16_to_cpu(
374 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
375 		*len = le32_to_cpu(
376 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
377 		break;
378 	default:
379 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
380 		break;
381 	}
382 
383 	/*
384 	 * Invalid length or offset probably means data area is invalid, but
385 	 * we have little choice but to ignore the data area in this case.
386 	 */
387 	if (*off > 4096) {
388 		cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
389 		*len = 0;
390 		*off = 0;
391 	} else if (*off < 0) {
392 		cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
393 			 *off);
394 		*off = 0;
395 		*len = 0;
396 	} else if (*len < 0) {
397 		cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
398 			 *len);
399 		*len = 0;
400 	} else if (*len > 128 * 1024) {
401 		cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
402 		*len = 0;
403 	}
404 
405 	/* return pointer to beginning of data area, ie offset from SMB start */
406 	if ((*off != 0) && (*len != 0))
407 		return (char *)shdr + *off;
408 	else
409 		return NULL;
410 }
411 
412 /*
413  * Calculate the size of the SMB message based on the fixed header
414  * portion, the number of word parameters and the data portion of the message.
415  */
416 unsigned int
417 smb2_calc_size(void *buf)
418 {
419 	struct smb2_pdu *pdu = buf;
420 	struct smb2_hdr *shdr = &pdu->hdr;
421 	int offset; /* the offset from the beginning of SMB to data area */
422 	int data_length; /* the length of the variable length data area */
423 	/* Structure Size has already been checked to make sure it is 64 */
424 	int len = le16_to_cpu(shdr->StructureSize);
425 
426 	/*
427 	 * StructureSize2, ie length of fixed parameter area has already
428 	 * been checked to make sure it is the correct length.
429 	 */
430 	len += le16_to_cpu(pdu->StructureSize2);
431 
432 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
433 		goto calc_size_exit;
434 
435 	smb2_get_data_area_len(&offset, &data_length, shdr);
436 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
437 
438 	if (data_length > 0) {
439 		/*
440 		 * Check to make sure that data area begins after fixed area,
441 		 * Note that last byte of the fixed area is part of data area
442 		 * for some commands, typically those with odd StructureSize,
443 		 * so we must add one to the calculation.
444 		 */
445 		if (offset + 1 < len) {
446 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
447 				 offset + 1, len);
448 			data_length = 0;
449 		} else {
450 			len = offset + data_length;
451 		}
452 	}
453 calc_size_exit:
454 	cifs_dbg(FYI, "SMB2 len %d\n", len);
455 	return len;
456 }
457 
458 /* Note: caller must free return buffer */
459 __le16 *
460 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
461 {
462 	int len;
463 	const char *start_of_path;
464 	__le16 *to;
465 	int map_type;
466 
467 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
468 		map_type = SFM_MAP_UNI_RSVD;
469 	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
470 		map_type = SFU_MAP_UNI_RSVD;
471 	else
472 		map_type = NO_MAP_UNI_RSVD;
473 
474 	/* Windows doesn't allow paths beginning with \ */
475 	if (from[0] == '\\')
476 		start_of_path = from + 1;
477 
478 	/* SMB311 POSIX extensions paths do not include leading slash */
479 	else if (cifs_sb_master_tlink(cifs_sb) &&
480 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
481 		 (from[0] == '/')) {
482 		start_of_path = from + 1;
483 	} else
484 		start_of_path = from;
485 
486 	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
487 				   cifs_sb->local_nls, map_type);
488 	return to;
489 }
490 
491 __le32
492 smb2_get_lease_state(struct cifsInodeInfo *cinode)
493 {
494 	__le32 lease = 0;
495 
496 	if (CIFS_CACHE_WRITE(cinode))
497 		lease |= SMB2_LEASE_WRITE_CACHING_LE;
498 	if (CIFS_CACHE_HANDLE(cinode))
499 		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
500 	if (CIFS_CACHE_READ(cinode))
501 		lease |= SMB2_LEASE_READ_CACHING_LE;
502 	return lease;
503 }
504 
505 struct smb2_lease_break_work {
506 	struct work_struct lease_break;
507 	struct tcon_link *tlink;
508 	__u8 lease_key[16];
509 	__le32 lease_state;
510 };
511 
512 static void
513 cifs_ses_oplock_break(struct work_struct *work)
514 {
515 	struct smb2_lease_break_work *lw = container_of(work,
516 				struct smb2_lease_break_work, lease_break);
517 	int rc = 0;
518 
519 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
520 			      lw->lease_state);
521 
522 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
523 	cifs_put_tlink(lw->tlink);
524 	kfree(lw);
525 }
526 
527 static void
528 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
529 			      __le32 new_lease_state)
530 {
531 	struct smb2_lease_break_work *lw;
532 
533 	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
534 	if (!lw) {
535 		cifs_put_tlink(tlink);
536 		return;
537 	}
538 
539 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
540 	lw->tlink = tlink;
541 	lw->lease_state = new_lease_state;
542 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
543 	queue_work(cifsiod_wq, &lw->lease_break);
544 }
545 
546 static bool
547 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
548 {
549 	__u8 lease_state;
550 	struct cifsFileInfo *cfile;
551 	struct cifsInodeInfo *cinode;
552 	int ack_req = le32_to_cpu(rsp->Flags &
553 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
554 
555 	lease_state = le32_to_cpu(rsp->NewLeaseState);
556 
557 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
558 		cinode = CIFS_I(d_inode(cfile->dentry));
559 
560 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
561 							SMB2_LEASE_KEY_SIZE))
562 			continue;
563 
564 		cifs_dbg(FYI, "found in the open list\n");
565 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
566 			 lease_state);
567 
568 		if (ack_req)
569 			cfile->oplock_break_cancelled = false;
570 		else
571 			cfile->oplock_break_cancelled = true;
572 
573 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
574 
575 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
576 		cfile->oplock_level = lease_state;
577 
578 		cifs_queue_oplock_break(cfile);
579 		return true;
580 	}
581 
582 	return false;
583 }
584 
585 static struct cifs_pending_open *
586 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
587 				  struct smb2_lease_break *rsp)
588 {
589 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
590 	int ack_req = le32_to_cpu(rsp->Flags &
591 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
592 	struct cifs_pending_open *open;
593 	struct cifs_pending_open *found = NULL;
594 
595 	list_for_each_entry(open, &tcon->pending_opens, olist) {
596 		if (memcmp(open->lease_key, rsp->LeaseKey,
597 			   SMB2_LEASE_KEY_SIZE))
598 			continue;
599 
600 		if (!found && ack_req) {
601 			found = open;
602 		}
603 
604 		cifs_dbg(FYI, "found in the pending open list\n");
605 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
606 			 lease_state);
607 
608 		open->oplock = lease_state;
609 	}
610 
611 	return found;
612 }
613 
614 static bool
615 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
616 {
617 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
618 	struct TCP_Server_Info *pserver;
619 	struct cifs_ses *ses;
620 	struct cifs_tcon *tcon;
621 	struct cifs_pending_open *open;
622 
623 	cifs_dbg(FYI, "Checking for lease break\n");
624 
625 	/* If server is a channel, select the primary channel */
626 	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
627 
628 	/* look up tcon based on tid & uid */
629 	spin_lock(&cifs_tcp_ses_lock);
630 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
631 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
632 			spin_lock(&tcon->open_file_lock);
633 			cifs_stats_inc(
634 				       &tcon->stats.cifs_stats.num_oplock_brks);
635 			if (smb2_tcon_has_lease(tcon, rsp)) {
636 				spin_unlock(&tcon->open_file_lock);
637 				spin_unlock(&cifs_tcp_ses_lock);
638 				return true;
639 			}
640 			open = smb2_tcon_find_pending_open_lease(tcon,
641 								 rsp);
642 			if (open) {
643 				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
644 				struct tcon_link *tlink;
645 
646 				tlink = cifs_get_tlink(open->tlink);
647 				memcpy(lease_key, open->lease_key,
648 				       SMB2_LEASE_KEY_SIZE);
649 				spin_unlock(&tcon->open_file_lock);
650 				spin_unlock(&cifs_tcp_ses_lock);
651 				smb2_queue_pending_open_break(tlink,
652 							      lease_key,
653 							      rsp->NewLeaseState);
654 				return true;
655 			}
656 			spin_unlock(&tcon->open_file_lock);
657 
658 			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
659 				spin_unlock(&cifs_tcp_ses_lock);
660 				return true;
661 			}
662 		}
663 	}
664 	spin_unlock(&cifs_tcp_ses_lock);
665 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
666 	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
667 				   le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
668 				   le64_to_cpu(rsp->hdr.SessionId),
669 				   *((u64 *)rsp->LeaseKey),
670 				   *((u64 *)&rsp->LeaseKey[8]));
671 
672 	return false;
673 }
674 
675 bool
676 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
677 {
678 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
679 	struct TCP_Server_Info *pserver;
680 	struct cifs_ses *ses;
681 	struct cifs_tcon *tcon;
682 	struct cifsInodeInfo *cinode;
683 	struct cifsFileInfo *cfile;
684 
685 	cifs_dbg(FYI, "Checking for oplock break\n");
686 
687 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
688 		return false;
689 
690 	if (rsp->StructureSize !=
691 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
692 		if (le16_to_cpu(rsp->StructureSize) == 44)
693 			return smb2_is_valid_lease_break(buffer, server);
694 		else
695 			return false;
696 	}
697 
698 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
699 
700 	/* If server is a channel, select the primary channel */
701 	pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
702 
703 	/* look up tcon based on tid & uid */
704 	spin_lock(&cifs_tcp_ses_lock);
705 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
706 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
707 
708 			spin_lock(&tcon->open_file_lock);
709 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
710 				if (rsp->PersistentFid !=
711 				    cfile->fid.persistent_fid ||
712 				    rsp->VolatileFid !=
713 				    cfile->fid.volatile_fid)
714 					continue;
715 
716 				cifs_dbg(FYI, "file id match, oplock break\n");
717 				cifs_stats_inc(
718 				    &tcon->stats.cifs_stats.num_oplock_brks);
719 				cinode = CIFS_I(d_inode(cfile->dentry));
720 				spin_lock(&cfile->file_info_lock);
721 				if (!CIFS_CACHE_WRITE(cinode) &&
722 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
723 					cfile->oplock_break_cancelled = true;
724 				else
725 					cfile->oplock_break_cancelled = false;
726 
727 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
728 					&cinode->flags);
729 
730 				cfile->oplock_epoch = 0;
731 				cfile->oplock_level = rsp->OplockLevel;
732 
733 				spin_unlock(&cfile->file_info_lock);
734 
735 				cifs_queue_oplock_break(cfile);
736 
737 				spin_unlock(&tcon->open_file_lock);
738 				spin_unlock(&cifs_tcp_ses_lock);
739 				return true;
740 			}
741 			spin_unlock(&tcon->open_file_lock);
742 		}
743 	}
744 	spin_unlock(&cifs_tcp_ses_lock);
745 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
746 	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
747 				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
748 				  le64_to_cpu(rsp->hdr.SessionId));
749 
750 	return true;
751 }
752 
753 void
754 smb2_cancelled_close_fid(struct work_struct *work)
755 {
756 	struct close_cancelled_open *cancelled = container_of(work,
757 					struct close_cancelled_open, work);
758 	struct cifs_tcon *tcon = cancelled->tcon;
759 	int rc;
760 
761 	if (cancelled->mid)
762 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
763 			      cancelled->mid);
764 	else
765 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
766 
767 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
768 			cancelled->fid.volatile_fid);
769 	if (rc)
770 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
771 
772 	cifs_put_tcon(tcon);
773 	kfree(cancelled);
774 }
775 
776 /*
777  * Caller should already has an extra reference to @tcon
778  * This function is used to queue work to close a handle to prevent leaks
779  * on the server.
780  * We handle two cases. If an open was interrupted after we sent the
781  * SMB2_CREATE to the server but before we processed the reply, and second
782  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
783  */
784 static int
785 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
786 			    __u64 persistent_fid, __u64 volatile_fid)
787 {
788 	struct close_cancelled_open *cancelled;
789 
790 	cancelled = kzalloc(sizeof(*cancelled), GFP_ATOMIC);
791 	if (!cancelled)
792 		return -ENOMEM;
793 
794 	cancelled->fid.persistent_fid = persistent_fid;
795 	cancelled->fid.volatile_fid = volatile_fid;
796 	cancelled->tcon = tcon;
797 	cancelled->cmd = cmd;
798 	cancelled->mid = mid;
799 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
800 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
801 
802 	return 0;
803 }
804 
805 int
806 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
807 			    __u64 volatile_fid)
808 {
809 	int rc;
810 
811 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
812 	spin_lock(&cifs_tcp_ses_lock);
813 	if (tcon->tc_count <= 0) {
814 		struct TCP_Server_Info *server = NULL;
815 
816 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
817 		spin_unlock(&cifs_tcp_ses_lock);
818 
819 		if (tcon->ses)
820 			server = tcon->ses->server;
821 
822 		cifs_server_dbg(FYI, "tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
823 				tcon->tid, persistent_fid, volatile_fid);
824 
825 		return 0;
826 	}
827 	tcon->tc_count++;
828 	spin_unlock(&cifs_tcp_ses_lock);
829 
830 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
831 					 persistent_fid, volatile_fid);
832 	if (rc)
833 		cifs_put_tcon(tcon);
834 
835 	return rc;
836 }
837 
838 int
839 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
840 {
841 	struct smb2_hdr *hdr = mid->resp_buf;
842 	struct smb2_create_rsp *rsp = mid->resp_buf;
843 	struct cifs_tcon *tcon;
844 	int rc;
845 
846 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
847 	    hdr->Status != STATUS_SUCCESS)
848 		return 0;
849 
850 	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
851 				  le32_to_cpu(hdr->Id.SyncId.TreeId));
852 	if (!tcon)
853 		return -ENOENT;
854 
855 	rc = __smb2_handle_cancelled_cmd(tcon,
856 					 le16_to_cpu(hdr->Command),
857 					 le64_to_cpu(hdr->MessageId),
858 					 rsp->PersistentFileId,
859 					 rsp->VolatileFileId);
860 	if (rc)
861 		cifs_put_tcon(tcon);
862 
863 	return rc;
864 }
865 
866 /**
867  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
868  *
869  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
870  * SMB2 header.
871  *
872  * @ses:	server session structure
873  * @server:	pointer to server info
874  * @iov:	array containing the SMB request we will send to the server
875  * @nvec:	number of array entries for the iov
876  */
877 int
878 smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
879 			   struct kvec *iov, int nvec)
880 {
881 	int i, rc;
882 	struct smb2_hdr *hdr;
883 	struct shash_desc *sha512 = NULL;
884 
885 	hdr = (struct smb2_hdr *)iov[0].iov_base;
886 	/* neg prot are always taken */
887 	if (hdr->Command == SMB2_NEGOTIATE)
888 		goto ok;
889 
890 	/*
891 	 * If we process a command which wasn't a negprot it means the
892 	 * neg prot was already done, so the server dialect was set
893 	 * and we can test it. Preauth requires 3.1.1 for now.
894 	 */
895 	if (server->dialect != SMB311_PROT_ID)
896 		return 0;
897 
898 	if (hdr->Command != SMB2_SESSION_SETUP)
899 		return 0;
900 
901 	/* skip last sess setup response */
902 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
903 	    && (hdr->Status == NT_STATUS_OK
904 		|| (hdr->Status !=
905 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
906 		return 0;
907 
908 ok:
909 	rc = smb311_crypto_shash_allocate(server);
910 	if (rc)
911 		return rc;
912 
913 	sha512 = server->secmech.sha512;
914 	rc = crypto_shash_init(sha512);
915 	if (rc) {
916 		cifs_dbg(VFS, "%s: Could not init sha512 shash\n", __func__);
917 		return rc;
918 	}
919 
920 	rc = crypto_shash_update(sha512, ses->preauth_sha_hash,
921 				 SMB2_PREAUTH_HASH_SIZE);
922 	if (rc) {
923 		cifs_dbg(VFS, "%s: Could not update sha512 shash\n", __func__);
924 		return rc;
925 	}
926 
927 	for (i = 0; i < nvec; i++) {
928 		rc = crypto_shash_update(sha512, iov[i].iov_base, iov[i].iov_len);
929 		if (rc) {
930 			cifs_dbg(VFS, "%s: Could not update sha512 shash\n",
931 				 __func__);
932 			return rc;
933 		}
934 	}
935 
936 	rc = crypto_shash_final(sha512, ses->preauth_sha_hash);
937 	if (rc) {
938 		cifs_dbg(VFS, "%s: Could not finalize sha512 shash\n",
939 			 __func__);
940 		return rc;
941 	}
942 
943 	return 0;
944 }
945