xref: /linux/fs/smb/client/smb2misc.c (revision fafb66e5903c2bcfc7b7e259042a8282f18a6faa)
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 <crypto/sha2.h>
11 #include <linux/ctype.h>
12 #include "cifsglob.h"
13 #include "cifsproto.h"
14 #include "smb2proto.h"
15 #include "cifs_debug.h"
16 #include "cifs_unicode.h"
17 #include "../common/smb2status.h"
18 #include "smb2glob.h"
19 #include "nterr.h"
20 #include "cached_dir.h"
21 
22 static unsigned int __smb2_calc_size(void *buf, bool *have_data,
23 				     bool *data_area_overlap);
24 
25 static int
26 check_smb2_hdr(struct smb2_hdr *shdr, __u64 mid)
27 {
28 	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
29 
30 	/*
31 	 * Make sure that this really is an SMB, that it is a response,
32 	 * and that the message ids match.
33 	 */
34 	if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
35 	    (mid == wire_mid)) {
36 		if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
37 			return 0;
38 		else {
39 			/* only one valid case where server sends us request */
40 			if (shdr->Command == SMB2_OPLOCK_BREAK)
41 				return 0;
42 			else
43 				cifs_dbg(VFS, "Received Request not response\n");
44 		}
45 	} else { /* bad signature or mid */
46 		if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
47 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
48 				 le32_to_cpu(shdr->ProtocolId));
49 		if (mid != wire_mid)
50 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
51 				 mid, wire_mid);
52 	}
53 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
54 	return 1;
55 }
56 
57 /*
58  *  The following table defines the expected "StructureSize" of SMB2 responses
59  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
60  *
61  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
62  *  indexed by command in host byte order
63  */
64 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
65 	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
66 	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
67 	/* SMB2_LOGOFF */ cpu_to_le16(4),
68 	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
69 	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
70 	/* SMB2_CREATE */ cpu_to_le16(89),
71 	/* SMB2_CLOSE */ cpu_to_le16(60),
72 	/* SMB2_FLUSH */ cpu_to_le16(4),
73 	/* SMB2_READ */ cpu_to_le16(17),
74 	/* SMB2_WRITE */ cpu_to_le16(17),
75 	/* SMB2_LOCK */ cpu_to_le16(4),
76 	/* SMB2_IOCTL */ cpu_to_le16(49),
77 	/* BB CHECK this ... not listed in documentation */
78 	/* SMB2_CANCEL */ cpu_to_le16(0),
79 	/* SMB2_ECHO */ cpu_to_le16(4),
80 	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
81 	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
82 	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
83 	/* SMB2_SET_INFO */ cpu_to_le16(2),
84 	/* BB FIXME can also be 44 for lease break */
85 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
86 };
87 
88 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_hdr) + sizeof(struct smb2_negotiate_rsp))
89 
90 static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len,
91 			      __u32 non_ctxlen)
92 {
93 	__u16 neg_count;
94 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
95 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
96 
97 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
98 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
99 	if ((neg_count == 0) ||
100 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
101 		return 0;
102 
103 	/*
104 	 * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
105 	 * which security mechanisms the server supports) make sure that
106 	 * the negotiate contexts start after it
107 	 */
108 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
109 	/*
110 	 * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
111 	 * and the latter is 1 byte bigger than the fix-sized area of the
112 	 * NEGOTIATE response
113 	 */
114 	if (nc_offset + 1 < non_ctxlen) {
115 		pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
116 		return 0;
117 	} else if (nc_offset + 1 == non_ctxlen) {
118 		cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
119 		size_of_pad_before_neg_ctxts = 0;
120 	} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
121 		/* has padding, but no SPNEGO blob */
122 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
123 	else
124 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
125 
126 	/* Verify that at least minimal negotiate contexts fit within frame */
127 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
128 		pr_warn_once("negotiate context goes beyond end\n");
129 		return 0;
130 	}
131 
132 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
133 		len - nc_offset, size_of_pad_before_neg_ctxts);
134 
135 	/* length of negcontexts including pad from end of sec blob to them */
136 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
137 }
138 
139 int
140 smb2_check_message(char *buf, unsigned int pdu_len, unsigned int len,
141 		   struct TCP_Server_Info *server)
142 {
143 	struct TCP_Server_Info *pserver;
144 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
145 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
146 	int hdr_size = sizeof(struct smb2_hdr);
147 	int pdu_size = sizeof(struct smb2_pdu);
148 	int command;
149 	__u32 calc_len; /* calculated length */
150 	__u64 mid;
151 	bool have_data;
152 	bool data_area_overlap;
153 
154 	/* If server is a channel, select the primary channel */
155 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
156 
157 	/*
158 	 * Add function to do table lookup of StructureSize by command
159 	 * ie Validate the wct via smb2_struct_sizes table above
160 	 */
161 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
162 		struct smb2_transform_hdr *thdr =
163 			(struct smb2_transform_hdr *)buf;
164 		struct cifs_ses *ses = NULL;
165 		struct cifs_ses *iter;
166 
167 		/* decrypt frame now that it is completely read in */
168 		spin_lock(&cifs_tcp_ses_lock);
169 		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
170 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
171 				ses = iter;
172 				break;
173 			}
174 		}
175 		spin_unlock(&cifs_tcp_ses_lock);
176 		if (!ses) {
177 			cifs_dbg(VFS, "no decryption - session id not found\n");
178 			return 1;
179 		}
180 	}
181 
182 	mid = le64_to_cpu(shdr->MessageId);
183 	if (check_smb2_hdr(shdr, mid))
184 		return 1;
185 
186 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
187 		cifs_dbg(VFS, "Invalid structure size %u\n",
188 			 le16_to_cpu(shdr->StructureSize));
189 		return 1;
190 	}
191 
192 	command = le16_to_cpu(shdr->Command);
193 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
194 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
195 		return 1;
196 	}
197 
198 	if (len < pdu_size) {
199 		if ((len >= hdr_size)
200 		    && (shdr->Status != 0)) {
201 			pdu->StructureSize2 = 0;
202 			/*
203 			 * As with SMB/CIFS, on some error cases servers may
204 			 * not return wct properly
205 			 */
206 			return 0;
207 		} else {
208 			cifs_dbg(VFS, "Length less than SMB header size\n");
209 		}
210 		return 1;
211 	}
212 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
213 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
214 			 mid);
215 		return 1;
216 	}
217 
218 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
219 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
220 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
221 			/* error packets have 9 byte structure size */
222 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
223 				 le16_to_cpu(pdu->StructureSize2), command);
224 			return 1;
225 		} else if (command == SMB2_OPLOCK_BREAK_HE
226 			   && (shdr->Status == 0)
227 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
228 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
229 			/* special case for SMB2.1 lease break message */
230 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
231 				 le16_to_cpu(pdu->StructureSize2));
232 			return 1;
233 		}
234 	}
235 
236 	have_data = false;
237 	data_area_overlap = false;
238 	calc_len = __smb2_calc_size(buf, &have_data, &data_area_overlap);
239 
240 	/* Reject responses whose data area overlaps the fixed area. */
241 	if (data_area_overlap)
242 		return 1;
243 
244 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
245 	 * be 0, and not a real miscalculation */
246 	if (command == SMB2_IOCTL_HE && calc_len == 0)
247 		return 0;
248 
249 	if (command == SMB2_NEGOTIATE_HE)
250 		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
251 
252 	if (len != calc_len) {
253 		/* create failed on symlink */
254 		if (command == SMB2_CREATE_HE &&
255 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK &&
256 		    len > calc_len)
257 			return 0;
258 		/* Windows 7 server returns 24 bytes more */
259 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
260 			return 0;
261 		/*
262 		 * Server can return one byte more due to implied bcc[0].
263 		 * Allow it only when there is no data area; if data_length > 0
264 		 * the +1 gap indicates an overreported data length rather than
265 		 * the bcc[0] omission.
266 		 */
267 		if (calc_len == len + 1 && !have_data)
268 			return 0;
269 
270 		/*
271 		 * Some windows servers (win2016) will pad also the final
272 		 * PDU in a compound to 8 bytes.
273 		 */
274 		if (ALIGN(calc_len, 8) == len)
275 			return 0;
276 
277 		/*
278 		 * MacOS server pads after SMB2.1 write response with 3 bytes
279 		 * of junk. Other servers match RFC1001 len to actual
280 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
281 		 * Some windows servers also pad up to 8 bytes when compounding.
282 		 */
283 		if (calc_len < len)
284 			return 0;
285 
286 		/* Only log a message if len was really miscalculated */
287 		if (unlikely(cifsFYI))
288 			cifs_dbg(FYI, "Server response too short: calculated "
289 				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
290 				 calc_len, len, command, mid);
291 		else
292 			pr_warn("Server response too short: calculated length "
293 				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
294 				calc_len, len, command, mid);
295 
296 		return 1;
297 	}
298 	return 0;
299 }
300 
301 /*
302  * The size of the variable area depends on the offset and length fields
303  * located in different fields for various SMB2 responses. SMB2 responses
304  * with no variable length info, show an offset of zero for the offset field.
305  */
306 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
307 	/* SMB2_NEGOTIATE */ true,
308 	/* SMB2_SESSION_SETUP */ true,
309 	/* SMB2_LOGOFF */ false,
310 	/* SMB2_TREE_CONNECT */	false,
311 	/* SMB2_TREE_DISCONNECT */ false,
312 	/* SMB2_CREATE */ true,
313 	/* SMB2_CLOSE */ false,
314 	/* SMB2_FLUSH */ false,
315 	/* SMB2_READ */	true,
316 	/* SMB2_WRITE */ false,
317 	/* SMB2_LOCK */	false,
318 	/* SMB2_IOCTL */ true,
319 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
320 	/* SMB2_ECHO */ false,
321 	/* SMB2_QUERY_DIRECTORY */ true,
322 	/* SMB2_CHANGE_NOTIFY */ true,
323 	/* SMB2_QUERY_INFO */ true,
324 	/* SMB2_SET_INFO */ false,
325 	/* SMB2_OPLOCK_BREAK */ false
326 };
327 
328 /*
329  * Returns the pointer to the beginning of the data area. Length of the data
330  * area and the offset to it (from the beginning of the smb are also returned.
331  */
332 char *
333 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
334 {
335 	const int max_off = 4096;
336 	const int max_len = 128 * 1024;
337 
338 	*off = 0;
339 	*len = 0;
340 
341 	/* error responses do not have data area */
342 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
343 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
344 						SMB2_ERROR_STRUCTURE_SIZE2_LE)
345 		return NULL;
346 
347 	/*
348 	 * Following commands have data areas so we have to get the location
349 	 * of the data buffer offset and data buffer length for the particular
350 	 * command.
351 	 */
352 	switch (shdr->Command) {
353 	case SMB2_NEGOTIATE:
354 		*off = le16_to_cpu(
355 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
356 		*len = le16_to_cpu(
357 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
358 		break;
359 	case SMB2_SESSION_SETUP:
360 		*off = le16_to_cpu(
361 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
362 		*len = le16_to_cpu(
363 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
364 		break;
365 	case SMB2_CREATE:
366 		*off = le32_to_cpu(
367 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
368 		*len = le32_to_cpu(
369 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
370 		break;
371 	case SMB2_QUERY_INFO:
372 		*off = le16_to_cpu(
373 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
374 		*len = le32_to_cpu(
375 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
376 		break;
377 	case SMB2_READ:
378 		/* TODO: is this a bug ? */
379 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
380 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
381 		break;
382 	case SMB2_QUERY_DIRECTORY:
383 		*off = le16_to_cpu(
384 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
385 		*len = le32_to_cpu(
386 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
387 		break;
388 	case SMB2_IOCTL:
389 		*off = le32_to_cpu(
390 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
391 		*len = le32_to_cpu(
392 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
393 		break;
394 	case SMB2_CHANGE_NOTIFY:
395 		*off = le16_to_cpu(
396 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
397 		*len = le32_to_cpu(
398 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
399 		break;
400 	default:
401 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
402 		break;
403 	}
404 
405 	/*
406 	 * Invalid length or offset probably means data area is invalid, but
407 	 * we have little choice but to ignore the data area in this case.
408 	 */
409 	if (unlikely(*off < 0 || *off > max_off ||
410 		     *len < 0 || *len > max_len)) {
411 		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
412 			 __func__, *off, *len);
413 		*off = 0;
414 		*len = 0;
415 	} else if (*off == 0) {
416 		*len = 0;
417 	}
418 
419 	/* return pointer to beginning of data area, ie offset from SMB start */
420 	if (*off > 0 && *len > 0)
421 		return (char *)shdr + *off;
422 	return NULL;
423 }
424 
425 /*
426  * Calculate the size of the SMB message based on the fixed header, fixed
427  * parameter area, and variable data area.
428  *
429  * If have_data is not NULL, it is set when a non-empty data area is found.
430  * If data_area_overlap is not NULL, it is set when the data area overlaps
431  * the fixed area.
432  */
433 static unsigned int
434 __smb2_calc_size(void *buf, bool *have_data, bool *data_area_overlap)
435 {
436 	struct smb2_pdu *pdu = buf;
437 	struct smb2_hdr *shdr = &pdu->hdr;
438 	int offset; /* the offset from the beginning of SMB to data area */
439 	int data_length = 0; /* the length of the variable length data area */
440 	/* Structure Size has already been checked to make sure it is 64 */
441 	int len = le16_to_cpu(shdr->StructureSize);
442 
443 	if (have_data)
444 		*have_data = false;
445 	if (data_area_overlap)
446 		*data_area_overlap = false;
447 
448 	/*
449 	 * StructureSize2, ie length of fixed parameter area has already
450 	 * been checked to make sure it is the correct length.
451 	 */
452 	len += le16_to_cpu(pdu->StructureSize2);
453 
454 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
455 		goto calc_size_exit;
456 
457 	smb2_get_data_area_len(&offset, &data_length, shdr);
458 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
459 
460 	if (data_length > 0) {
461 		/*
462 		 * Check to make sure that data area begins after fixed area,
463 		 * Note that last byte of the fixed area is part of data area
464 		 * for some commands, typically those with odd StructureSize,
465 		 * so we must add one to the calculation.
466 		 */
467 		if (offset + 1 < len) {
468 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
469 				 offset + 1, len);
470 			if (data_area_overlap)
471 				*data_area_overlap = true;
472 			data_length = 0;
473 			goto calc_size_exit;
474 		} else {
475 			len = offset + data_length;
476 		}
477 	}
478 calc_size_exit:
479 	cifs_dbg(FYI, "SMB2 len %d\n", len);
480 	if (have_data)
481 		*have_data = (data_length > 0);
482 	return len;
483 }
484 
485 unsigned int
486 smb2_calc_size(void *buf)
487 {
488 	return __smb2_calc_size(buf, NULL, NULL);
489 }
490 
491 /* Note: caller must free return buffer */
492 __le16 *
493 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
494 {
495 	const char *start_of_path;
496 	int len;
497 
498 	/* Windows doesn't allow paths beginning with \ */
499 	if (from[0] == '\\')
500 		start_of_path = from + 1;
501 
502 	/* SMB311 POSIX extensions paths do not include leading slash */
503 	else if (cifs_sb_master_tlink(cifs_sb) &&
504 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
505 		 (from[0] == '/')) {
506 		start_of_path = from + 1;
507 	} else
508 		start_of_path = from;
509 
510 	return cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
511 				     cifs_sb->local_nls, cifs_remap(cifs_sb));
512 }
513 
514 __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode, unsigned int oplock)
515 {
516 	unsigned int sbflags = cifs_sb_flags(CIFS_SB(cinode));
517 	__le32 lease = 0;
518 
519 	if ((oplock & CIFS_CACHE_WRITE_FLG) || (sbflags & CIFS_MOUNT_RW_CACHE))
520 		lease |= SMB2_LEASE_WRITE_CACHING_LE;
521 	if (oplock & CIFS_CACHE_HANDLE_FLG)
522 		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
523 	if ((oplock & CIFS_CACHE_READ_FLG) || (sbflags & CIFS_MOUNT_RO_CACHE))
524 		lease |= SMB2_LEASE_READ_CACHING_LE;
525 	return lease;
526 }
527 
528 struct smb2_lease_break_work {
529 	struct work_struct lease_break;
530 	struct tcon_link *tlink;
531 	__u8 lease_key[16];
532 	__le32 lease_state;
533 };
534 
535 static void
536 cifs_ses_oplock_break(struct work_struct *work)
537 {
538 	struct smb2_lease_break_work *lw = container_of(work,
539 				struct smb2_lease_break_work, lease_break);
540 	int rc = 0;
541 
542 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
543 			      lw->lease_state);
544 
545 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
546 	cifs_put_tlink(lw->tlink);
547 	kfree(lw);
548 }
549 
550 static void
551 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
552 			      __le32 new_lease_state)
553 {
554 	struct smb2_lease_break_work *lw;
555 
556 	lw = kmalloc_obj(struct smb2_lease_break_work);
557 	if (!lw) {
558 		cifs_put_tlink(tlink);
559 		return;
560 	}
561 
562 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
563 	lw->tlink = tlink;
564 	lw->lease_state = new_lease_state;
565 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
566 	queue_work(cifsiod_wq, &lw->lease_break);
567 }
568 
569 static bool
570 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
571 {
572 	__u8 lease_state;
573 	struct cifsFileInfo *cfile;
574 	struct cifsInodeInfo *cinode;
575 	int ack_req = le32_to_cpu(rsp->Flags &
576 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
577 
578 	lease_state = le32_to_cpu(rsp->NewLeaseState);
579 
580 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
581 		cinode = CIFS_I(d_inode(cfile->dentry));
582 
583 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
584 							SMB2_LEASE_KEY_SIZE))
585 			continue;
586 
587 		cifs_dbg(FYI, "found in the open list\n");
588 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
589 			 lease_state);
590 
591 		if (ack_req)
592 			cfile->oplock_break_cancelled = false;
593 		else
594 			cfile->oplock_break_cancelled = true;
595 
596 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
597 
598 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
599 		cfile->oplock_level = lease_state;
600 
601 		cifs_queue_oplock_break(cfile);
602 		return true;
603 	}
604 
605 	return false;
606 }
607 
608 static struct cifs_pending_open *
609 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
610 				  struct smb2_lease_break *rsp)
611 {
612 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
613 	int ack_req = le32_to_cpu(rsp->Flags &
614 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
615 	struct cifs_pending_open *open;
616 	struct cifs_pending_open *found = NULL;
617 
618 	list_for_each_entry(open, &tcon->pending_opens, olist) {
619 		if (memcmp(open->lease_key, rsp->LeaseKey,
620 			   SMB2_LEASE_KEY_SIZE))
621 			continue;
622 
623 		if (!found && ack_req) {
624 			found = open;
625 		}
626 
627 		cifs_dbg(FYI, "found in the pending open list\n");
628 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
629 			 lease_state);
630 
631 		open->oplock = lease_state;
632 	}
633 
634 	return found;
635 }
636 
637 static bool
638 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
639 {
640 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
641 	struct TCP_Server_Info *pserver;
642 	struct cifs_ses *ses;
643 	struct cifs_tcon *tcon;
644 	struct cifs_pending_open *open;
645 
646 	/* Trace receipt of lease break request from server */
647 	trace_smb3_lease_break_enter(le32_to_cpu(rsp->CurrentLeaseState),
648 		le32_to_cpu(rsp->Flags),
649 		le16_to_cpu(rsp->Epoch),
650 		le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
651 		le64_to_cpu(rsp->hdr.SessionId),
652 		*((u64 *)rsp->LeaseKey),
653 		*((u64 *)&rsp->LeaseKey[8]));
654 
655 	cifs_dbg(FYI, "Checking for lease break\n");
656 
657 	/* If server is a channel, select the primary channel */
658 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
659 
660 	/* look up tcon based on tid & uid */
661 	spin_lock(&cifs_tcp_ses_lock);
662 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
663 		if (cifs_ses_exiting(ses))
664 			continue;
665 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
666 			spin_lock(&tcon->open_file_lock);
667 			cifs_stats_inc(
668 				       &tcon->stats.cifs_stats.num_oplock_brks);
669 			if (smb2_tcon_has_lease(tcon, rsp)) {
670 				spin_unlock(&tcon->open_file_lock);
671 				spin_unlock(&cifs_tcp_ses_lock);
672 				return true;
673 			}
674 			open = smb2_tcon_find_pending_open_lease(tcon,
675 								 rsp);
676 			if (open) {
677 				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
678 				struct tcon_link *tlink;
679 
680 				tlink = cifs_get_tlink(open->tlink);
681 				memcpy(lease_key, open->lease_key,
682 				       SMB2_LEASE_KEY_SIZE);
683 				spin_unlock(&tcon->open_file_lock);
684 				spin_unlock(&cifs_tcp_ses_lock);
685 				smb2_queue_pending_open_break(tlink,
686 							      lease_key,
687 							      rsp->NewLeaseState);
688 				return true;
689 			}
690 			spin_unlock(&tcon->open_file_lock);
691 
692 			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
693 				spin_unlock(&cifs_tcp_ses_lock);
694 				return true;
695 			}
696 		}
697 	}
698 	spin_unlock(&cifs_tcp_ses_lock);
699 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
700 	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
701 					   le32_to_cpu(rsp->Flags),
702 					   le16_to_cpu(rsp->Epoch),
703 					   le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
704 					   le64_to_cpu(rsp->hdr.SessionId),
705 					   *((u64 *)rsp->LeaseKey),
706 					   *((u64 *)&rsp->LeaseKey[8]));
707 
708 	return false;
709 }
710 
711 bool
712 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
713 {
714 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
715 	struct TCP_Server_Info *pserver;
716 	struct cifs_ses *ses;
717 	struct cifs_tcon *tcon;
718 	struct cifsInodeInfo *cinode;
719 	struct cifsFileInfo *cfile;
720 
721 	cifs_dbg(FYI, "Checking for oplock break\n");
722 
723 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
724 		return false;
725 
726 	if (rsp->StructureSize !=
727 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
728 		if (le16_to_cpu(rsp->StructureSize) == 44)
729 			return smb2_is_valid_lease_break(buffer, server);
730 		else
731 			return false;
732 	}
733 
734 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
735 
736 	/* If server is a channel, select the primary channel */
737 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
738 
739 	/* look up tcon based on tid & uid */
740 	spin_lock(&cifs_tcp_ses_lock);
741 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
742 		if (cifs_ses_exiting(ses))
743 			continue;
744 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
745 
746 			spin_lock(&tcon->open_file_lock);
747 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
748 				if (rsp->PersistentFid !=
749 				    cfile->fid.persistent_fid ||
750 				    rsp->VolatileFid !=
751 				    cfile->fid.volatile_fid)
752 					continue;
753 
754 				cifs_dbg(FYI, "file id match, oplock break\n");
755 				cifs_stats_inc(
756 				    &tcon->stats.cifs_stats.num_oplock_brks);
757 				cinode = CIFS_I(d_inode(cfile->dentry));
758 				spin_lock(&cfile->file_info_lock);
759 				if (!CIFS_CACHE_WRITE(cinode) &&
760 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
761 					cfile->oplock_break_cancelled = true;
762 				else
763 					cfile->oplock_break_cancelled = false;
764 
765 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
766 					&cinode->flags);
767 
768 				cfile->oplock_epoch = 0;
769 				cfile->oplock_level = rsp->OplockLevel;
770 
771 				spin_unlock(&cfile->file_info_lock);
772 
773 				cifs_queue_oplock_break(cfile);
774 
775 				spin_unlock(&tcon->open_file_lock);
776 				spin_unlock(&cifs_tcp_ses_lock);
777 				return true;
778 			}
779 			spin_unlock(&tcon->open_file_lock);
780 		}
781 	}
782 	spin_unlock(&cifs_tcp_ses_lock);
783 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
784 	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
785 				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
786 				  le64_to_cpu(rsp->hdr.SessionId));
787 
788 	return true;
789 }
790 
791 void
792 smb2_cancelled_close_fid(struct work_struct *work)
793 {
794 	struct close_cancelled_open *cancelled = container_of(work,
795 					struct close_cancelled_open, work);
796 	struct cifs_tcon *tcon = cancelled->tcon;
797 	int rc;
798 
799 	if (cancelled->mid)
800 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
801 			      cancelled->mid);
802 	else
803 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
804 
805 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
806 			cancelled->fid.volatile_fid);
807 	if (rc)
808 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
809 
810 	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
811 	kfree(cancelled);
812 }
813 
814 /*
815  * Caller should already has an extra reference to @tcon
816  * This function is used to queue work to close a handle to prevent leaks
817  * on the server.
818  * We handle two cases. If an open was interrupted after we sent the
819  * SMB2_CREATE to the server but before we processed the reply, and second
820  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
821  */
822 static int
823 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
824 			    __u64 persistent_fid, __u64 volatile_fid)
825 {
826 	struct close_cancelled_open *cancelled;
827 
828 	cancelled = kzalloc_obj(*cancelled);
829 	if (!cancelled)
830 		return -ENOMEM;
831 
832 	cancelled->fid.persistent_fid = persistent_fid;
833 	cancelled->fid.volatile_fid = volatile_fid;
834 	cancelled->tcon = tcon;
835 	cancelled->cmd = cmd;
836 	cancelled->mid = mid;
837 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
838 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
839 
840 	return 0;
841 }
842 
843 int
844 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
845 			    __u64 volatile_fid)
846 {
847 	int rc;
848 
849 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
850 	spin_lock(&tcon->tc_lock);
851 	if (tcon->tc_count <= 0) {
852 		struct TCP_Server_Info *server = NULL;
853 
854 		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
855 				    netfs_trace_tcon_ref_see_cancelled_close);
856 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
857 		spin_unlock(&tcon->tc_lock);
858 
859 		if (tcon->ses) {
860 			server = tcon->ses->server;
861 			cifs_server_dbg(FYI,
862 					"tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
863 					tcon->tid, persistent_fid, volatile_fid);
864 		}
865 
866 		return 0;
867 	}
868 	tcon->tc_count++;
869 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
870 			    netfs_trace_tcon_ref_get_cancelled_close);
871 	spin_unlock(&tcon->tc_lock);
872 
873 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
874 					 persistent_fid, volatile_fid);
875 	if (rc)
876 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
877 
878 	return rc;
879 }
880 
881 int
882 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
883 {
884 	struct smb2_hdr *hdr = mid->resp_buf;
885 	struct smb2_create_rsp *rsp = mid->resp_buf;
886 	struct cifs_tcon *tcon;
887 	int rc;
888 
889 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
890 	    hdr->Status != STATUS_SUCCESS)
891 		return 0;
892 
893 	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
894 				  le32_to_cpu(hdr->Id.SyncId.TreeId));
895 	if (!tcon)
896 		return -ENOENT;
897 
898 	rc = __smb2_handle_cancelled_cmd(tcon,
899 					 le16_to_cpu(hdr->Command),
900 					 le64_to_cpu(hdr->MessageId),
901 					 rsp->PersistentFileId,
902 					 rsp->VolatileFileId);
903 	if (rc)
904 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
905 
906 	return rc;
907 }
908 
909 /**
910  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
911  *
912  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
913  * SMB2 header.
914  *
915  * @ses:	server session structure
916  * @server:	pointer to server info
917  * @iov:	array containing the SMB request we will send to the server
918  * @nvec:	number of array entries for the iov
919  */
920 void
921 smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
922 			   struct kvec *iov, int nvec)
923 {
924 	int i;
925 	struct smb2_hdr *hdr;
926 	struct sha512_ctx sha_ctx;
927 
928 	hdr = (struct smb2_hdr *)iov[0].iov_base;
929 	/* neg prot are always taken */
930 	if (hdr->Command == SMB2_NEGOTIATE)
931 		goto ok;
932 
933 	/*
934 	 * If we process a command which wasn't a negprot it means the
935 	 * neg prot was already done, so the server dialect was set
936 	 * and we can test it. Preauth requires 3.1.1 for now.
937 	 */
938 	if (server->dialect != SMB311_PROT_ID)
939 		return;
940 
941 	if (hdr->Command != SMB2_SESSION_SETUP)
942 		return;
943 
944 	/* skip last sess setup response */
945 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
946 	    && (hdr->Status == NT_STATUS_OK
947 		|| (hdr->Status !=
948 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
949 		return;
950 
951 ok:
952 	sha512_init(&sha_ctx);
953 	sha512_update(&sha_ctx, ses->preauth_sha_hash, SMB2_PREAUTH_HASH_SIZE);
954 	for (i = 0; i < nvec; i++)
955 		sha512_update(&sha_ctx, iov[i].iov_base, iov[i].iov_len);
956 	sha512_final(&sha_ctx, ses->preauth_sha_hash);
957 }
958