xref: /linux/fs/smb/client/smb2misc.c (revision b4694f269e66dfcd66991446375285723b6957bd)
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 /*
89  * Minimum received PDU size for commands whose response carries a
90  * variable-length data area.  A non-zero entry marks the command as
91  * having one, and gives the length smb2_check_message() requires
92  * before smb2_get_data_area_len() reads the offset and length fields
93  * out of the fixed response struct.
94  */
95 static const size_t smb2_min_pdu_len[NUMBER_OF_SMB2_COMMANDS] = {
96 	/* SMB2_NEGOTIATE */       sizeof(struct smb2_negotiate_rsp),
97 	/* SMB2_SESSION_SETUP */   sizeof(struct smb2_sess_setup_rsp),
98 	/* SMB2_LOGOFF */          0,
99 	/* SMB2_TREE_CONNECT */    0,
100 	/* SMB2_TREE_DISCONNECT */ 0,
101 	/* SMB2_CREATE */          sizeof(struct smb2_create_rsp),
102 	/* SMB2_CLOSE */           0,
103 	/* SMB2_FLUSH */           0,
104 	/* SMB2_READ */            sizeof(struct smb2_read_rsp),
105 	/* SMB2_WRITE */           0,
106 	/* SMB2_LOCK */            0,
107 	/* SMB2_IOCTL */           sizeof(struct smb2_ioctl_rsp),
108 	/* SMB2_CANCEL */          0,
109 	/* SMB2_ECHO */            0,
110 	/* SMB2_QUERY_DIRECTORY */ sizeof(struct smb2_query_directory_rsp),
111 	/* SMB2_CHANGE_NOTIFY */   sizeof(struct smb2_change_notify_rsp),
112 	/* SMB2_QUERY_INFO */      sizeof(struct smb2_query_info_rsp),
113 	/* SMB2_SET_INFO */        0,
114 	/* SMB2_OPLOCK_BREAK */    0,
115 };
116 
117 #define smb2_has_data_area(cmd) (smb2_min_pdu_len[cmd] != 0)
118 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_hdr) + sizeof(struct smb2_negotiate_rsp))
119 
120 static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len,
121 			      __u32 non_ctxlen)
122 {
123 	__u16 neg_count;
124 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
125 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
126 
127 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
128 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
129 	if ((neg_count == 0) ||
130 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
131 		return 0;
132 
133 	/*
134 	 * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
135 	 * which security mechanisms the server supports) make sure that
136 	 * the negotiate contexts start after it
137 	 */
138 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
139 	/*
140 	 * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
141 	 * and the latter is 1 byte bigger than the fix-sized area of the
142 	 * NEGOTIATE response
143 	 */
144 	if (nc_offset + 1 < non_ctxlen) {
145 		pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
146 		return 0;
147 	} else if (nc_offset + 1 == non_ctxlen) {
148 		cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
149 		size_of_pad_before_neg_ctxts = 0;
150 	} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
151 		/* has padding, but no SPNEGO blob */
152 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
153 	else
154 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
155 
156 	/* Verify that at least minimal negotiate contexts fit within frame */
157 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
158 		pr_warn_once("negotiate context goes beyond end\n");
159 		return 0;
160 	}
161 
162 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
163 		len - nc_offset, size_of_pad_before_neg_ctxts);
164 
165 	/* length of negcontexts including pad from end of sec blob to them */
166 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
167 }
168 
169 int
170 smb2_check_message(char *buf, unsigned int pdu_len, unsigned int len,
171 		   struct TCP_Server_Info *server)
172 {
173 	struct TCP_Server_Info *pserver;
174 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
175 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
176 	int hdr_size = sizeof(struct smb2_hdr);
177 	int pdu_size = sizeof(struct smb2_pdu);
178 	int command;
179 	__u32 calc_len; /* calculated length */
180 	__u64 mid;
181 	bool have_data;
182 	bool data_area_overlap;
183 
184 	/* If server is a channel, select the primary channel */
185 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
186 
187 	/*
188 	 * Add function to do table lookup of StructureSize by command
189 	 * ie Validate the wct via smb2_struct_sizes table above
190 	 */
191 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
192 		struct smb2_transform_hdr *thdr =
193 			(struct smb2_transform_hdr *)buf;
194 		struct cifs_ses *ses = NULL;
195 		struct cifs_ses *iter;
196 
197 		/* decrypt frame now that it is completely read in */
198 		spin_lock(&cifs_tcp_ses_lock);
199 		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
200 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
201 				ses = iter;
202 				break;
203 			}
204 		}
205 		spin_unlock(&cifs_tcp_ses_lock);
206 		if (!ses) {
207 			cifs_dbg(VFS, "no decryption - session id not found\n");
208 			return 1;
209 		}
210 	}
211 
212 	mid = le64_to_cpu(shdr->MessageId);
213 	if (check_smb2_hdr(shdr, mid))
214 		return 1;
215 
216 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
217 		cifs_dbg(VFS, "Invalid structure size %u\n",
218 			 le16_to_cpu(shdr->StructureSize));
219 		return 1;
220 	}
221 
222 	command = le16_to_cpu(shdr->Command);
223 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
224 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
225 		return 1;
226 	}
227 
228 	if (len < pdu_size) {
229 		if ((len >= hdr_size)
230 		    && (shdr->Status != 0)) {
231 			pdu->StructureSize2 = 0;
232 			/*
233 			 * As with SMB/CIFS, on some error cases servers may
234 			 * not return wct properly
235 			 */
236 			return 0;
237 		} else {
238 			cifs_dbg(VFS, "Length less than SMB header size\n");
239 		}
240 		return 1;
241 	}
242 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
243 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
244 			 mid);
245 		return 1;
246 	}
247 
248 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
249 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
250 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
251 			/* error packets have 9 byte structure size */
252 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
253 				 le16_to_cpu(pdu->StructureSize2), command);
254 			return 1;
255 		} else if (command == SMB2_OPLOCK_BREAK_HE
256 			   && (shdr->Status == 0)
257 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
258 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
259 			/* special case for SMB2.1 lease break message */
260 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
261 				 le16_to_cpu(pdu->StructureSize2));
262 			return 1;
263 		}
264 	}
265 
266 	if ((shdr->Status == STATUS_SUCCESS ||
267 	     shdr->Status == STATUS_MORE_PROCESSING_REQUIRED ||
268 	     pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE) &&
269 	    smb2_has_data_area(command) &&
270 	    len < smb2_min_pdu_len[command]) {
271 		cifs_server_dbg(VFS, "SMB2 command %d response too short: %u < %zu\n",
272 				command, len, smb2_min_pdu_len[command]);
273 		return 1;
274 	}
275 
276 	have_data = false;
277 	data_area_overlap = false;
278 	calc_len = __smb2_calc_size(buf, &have_data, &data_area_overlap);
279 
280 	/* Reject responses whose data area overlaps the fixed area. */
281 	if (data_area_overlap)
282 		return 1;
283 
284 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
285 	 * be 0, and not a real miscalculation */
286 	if (command == SMB2_IOCTL_HE && calc_len == 0)
287 		return 0;
288 
289 	if (command == SMB2_NEGOTIATE_HE)
290 		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
291 
292 	if (len != calc_len) {
293 		/* create failed on symlink */
294 		if (command == SMB2_CREATE_HE &&
295 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK &&
296 		    len > calc_len)
297 			return 0;
298 		/* Windows 7 server returns 24 bytes more */
299 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
300 			return 0;
301 		/*
302 		 * Server can return one byte more due to implied bcc[0].
303 		 * Allow it only when there is no data area; if data_length > 0
304 		 * the +1 gap indicates an overreported data length rather than
305 		 * the bcc[0] omission.
306 		 */
307 		if (calc_len == len + 1 && !have_data)
308 			return 0;
309 
310 		/*
311 		 * Some windows servers (win2016) will pad also the final
312 		 * PDU in a compound to 8 bytes.
313 		 */
314 		if (ALIGN(calc_len, 8) == len)
315 			return 0;
316 
317 		/*
318 		 * MacOS server pads after SMB2.1 write response with 3 bytes
319 		 * of junk. Other servers match RFC1001 len to actual
320 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
321 		 * Some windows servers also pad up to 8 bytes when compounding.
322 		 */
323 		if (calc_len < len)
324 			return 0;
325 
326 		/* Only log a message if len was really miscalculated */
327 		if (unlikely(cifsFYI))
328 			cifs_dbg(FYI, "Server response too short: calculated "
329 				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
330 				 calc_len, len, command, mid);
331 		else
332 			pr_warn("Server response too short: calculated length "
333 				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
334 				calc_len, len, command, mid);
335 
336 		return 1;
337 	}
338 	return 0;
339 }
340 
341 /*
342  * Returns the pointer to the beginning of the data area. Length of the data
343  * area and the offset to it (from the beginning of the smb are also returned.
344  */
345 char *
346 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
347 {
348 	const int max_off = 4096;
349 	const int max_len = 128 * 1024;
350 
351 	*off = 0;
352 	*len = 0;
353 
354 	/* error responses do not have data area */
355 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
356 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
357 						SMB2_ERROR_STRUCTURE_SIZE2_LE)
358 		return NULL;
359 
360 	/*
361 	 * Following commands have data areas so we have to get the location
362 	 * of the data buffer offset and data buffer length for the particular
363 	 * command.
364 	 */
365 	switch (shdr->Command) {
366 	case SMB2_NEGOTIATE:
367 		*off = le16_to_cpu(
368 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
369 		*len = le16_to_cpu(
370 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
371 		break;
372 	case SMB2_SESSION_SETUP:
373 		*off = le16_to_cpu(
374 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
375 		*len = le16_to_cpu(
376 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
377 		break;
378 	case SMB2_CREATE:
379 		*off = le32_to_cpu(
380 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
381 		*len = le32_to_cpu(
382 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
383 		break;
384 	case SMB2_QUERY_INFO:
385 		*off = le16_to_cpu(
386 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
387 		*len = le32_to_cpu(
388 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
389 		break;
390 	case SMB2_READ:
391 		/* TODO: is this a bug ? */
392 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
393 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
394 		break;
395 	case SMB2_QUERY_DIRECTORY:
396 		*off = le16_to_cpu(
397 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
398 		*len = le32_to_cpu(
399 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
400 		break;
401 	case SMB2_IOCTL:
402 		*off = le32_to_cpu(
403 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
404 		*len = le32_to_cpu(
405 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
406 		break;
407 	case SMB2_CHANGE_NOTIFY:
408 		*off = le16_to_cpu(
409 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
410 		*len = le32_to_cpu(
411 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
412 		break;
413 	default:
414 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
415 		break;
416 	}
417 
418 	/*
419 	 * Invalid length or offset probably means data area is invalid, but
420 	 * we have little choice but to ignore the data area in this case.
421 	 */
422 	if (unlikely(*off < 0 || *off > max_off ||
423 		     *len < 0 || *len > max_len)) {
424 		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
425 			 __func__, *off, *len);
426 		*off = 0;
427 		*len = 0;
428 	} else if (*off == 0) {
429 		*len = 0;
430 	}
431 
432 	/* return pointer to beginning of data area, ie offset from SMB start */
433 	if (*off > 0 && *len > 0)
434 		return (char *)shdr + *off;
435 	return NULL;
436 }
437 
438 /*
439  * Calculate the size of the SMB message based on the fixed header, fixed
440  * parameter area, and variable data area.
441  *
442  * If have_data is not NULL, it is set when a non-empty data area is found.
443  * If data_area_overlap is not NULL, it is set when the data area overlaps
444  * the fixed area.
445  */
446 static unsigned int
447 __smb2_calc_size(void *buf, bool *have_data, bool *data_area_overlap)
448 {
449 	struct smb2_pdu *pdu = buf;
450 	struct smb2_hdr *shdr = &pdu->hdr;
451 	int offset; /* the offset from the beginning of SMB to data area */
452 	int data_length = 0; /* the length of the variable length data area */
453 	/* Structure Size has already been checked to make sure it is 64 */
454 	int len = le16_to_cpu(shdr->StructureSize);
455 
456 	if (have_data)
457 		*have_data = false;
458 	if (data_area_overlap)
459 		*data_area_overlap = false;
460 
461 	/*
462 	 * StructureSize2, ie length of fixed parameter area has already
463 	 * been checked to make sure it is the correct length.
464 	 */
465 	len += le16_to_cpu(pdu->StructureSize2);
466 
467 	if (!smb2_has_data_area(le16_to_cpu(shdr->Command)))
468 		goto calc_size_exit;
469 
470 	smb2_get_data_area_len(&offset, &data_length, shdr);
471 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
472 
473 	if (data_length > 0) {
474 		/*
475 		 * Check to make sure that data area begins after fixed area,
476 		 * Note that last byte of the fixed area is part of data area
477 		 * for some commands, typically those with odd StructureSize,
478 		 * so we must add one to the calculation.
479 		 */
480 		if (offset + 1 < len) {
481 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
482 				 offset + 1, len);
483 			if (data_area_overlap)
484 				*data_area_overlap = true;
485 			data_length = 0;
486 			goto calc_size_exit;
487 		} else {
488 			len = offset + data_length;
489 		}
490 	}
491 calc_size_exit:
492 	cifs_dbg(FYI, "SMB2 len %d\n", len);
493 	if (have_data)
494 		*have_data = (data_length > 0);
495 	return len;
496 }
497 
498 unsigned int
499 smb2_calc_size(void *buf)
500 {
501 	return __smb2_calc_size(buf, NULL, NULL);
502 }
503 
504 /* Note: caller must free return buffer */
505 __le16 *
506 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
507 {
508 	const char *start_of_path;
509 	int len;
510 
511 	/* Windows doesn't allow paths beginning with \ */
512 	if (from[0] == '\\')
513 		start_of_path = from + 1;
514 
515 	/* SMB311 POSIX extensions paths do not include leading slash */
516 	else if (cifs_sb_master_tlink(cifs_sb) &&
517 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
518 		 (from[0] == '/')) {
519 		start_of_path = from + 1;
520 	} else
521 		start_of_path = from;
522 
523 	return cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
524 				     cifs_sb->local_nls, cifs_remap(cifs_sb));
525 }
526 
527 __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode, unsigned int oplock)
528 {
529 	unsigned int sbflags = cifs_sb_flags(CIFS_SB(cinode));
530 	__le32 lease = 0;
531 
532 	if ((oplock & CIFS_CACHE_WRITE_FLG) || (sbflags & CIFS_MOUNT_RW_CACHE))
533 		lease |= SMB2_LEASE_WRITE_CACHING_LE;
534 	if (oplock & CIFS_CACHE_HANDLE_FLG)
535 		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
536 	if ((oplock & CIFS_CACHE_READ_FLG) || (sbflags & CIFS_MOUNT_RO_CACHE))
537 		lease |= SMB2_LEASE_READ_CACHING_LE;
538 	return lease;
539 }
540 
541 struct smb2_lease_break_work {
542 	struct work_struct lease_break;
543 	struct tcon_link *tlink;
544 	__u8 lease_key[16];
545 	__le32 lease_state;
546 };
547 
548 static void
549 cifs_ses_oplock_break(struct work_struct *work)
550 {
551 	struct smb2_lease_break_work *lw = container_of(work,
552 				struct smb2_lease_break_work, lease_break);
553 	int rc = 0;
554 
555 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
556 			      lw->lease_state);
557 
558 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
559 	cifs_put_tlink(lw->tlink);
560 	kfree(lw);
561 }
562 
563 static void
564 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
565 			      __le32 new_lease_state)
566 {
567 	struct smb2_lease_break_work *lw;
568 
569 	lw = kmalloc_obj(struct smb2_lease_break_work);
570 	if (!lw) {
571 		cifs_put_tlink(tlink);
572 		return;
573 	}
574 
575 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
576 	lw->tlink = tlink;
577 	lw->lease_state = new_lease_state;
578 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
579 	queue_work(cifsiod_wq, &lw->lease_break);
580 }
581 
582 static bool
583 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
584 {
585 	__u8 lease_state;
586 	struct cifsFileInfo *cfile;
587 	struct cifsInodeInfo *cinode;
588 	int ack_req = le32_to_cpu(rsp->Flags &
589 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
590 
591 	lease_state = le32_to_cpu(rsp->NewLeaseState);
592 
593 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
594 		cinode = CIFS_I(d_inode(cfile->dentry));
595 
596 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
597 							SMB2_LEASE_KEY_SIZE))
598 			continue;
599 
600 		cifs_dbg(FYI, "found in the open list\n");
601 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
602 			 lease_state);
603 
604 		if (ack_req)
605 			cfile->oplock_break_cancelled = false;
606 		else
607 			cfile->oplock_break_cancelled = true;
608 
609 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
610 
611 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
612 		cfile->oplock_level = lease_state;
613 
614 		cifs_queue_oplock_break(cfile);
615 		return true;
616 	}
617 
618 	return false;
619 }
620 
621 static struct cifs_pending_open *
622 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
623 				  struct smb2_lease_break *rsp)
624 {
625 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
626 	int ack_req = le32_to_cpu(rsp->Flags &
627 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
628 	struct cifs_pending_open *open;
629 	struct cifs_pending_open *found = NULL;
630 
631 	list_for_each_entry(open, &tcon->pending_opens, olist) {
632 		if (memcmp(open->lease_key, rsp->LeaseKey,
633 			   SMB2_LEASE_KEY_SIZE))
634 			continue;
635 
636 		if (!found && ack_req) {
637 			found = open;
638 		}
639 
640 		cifs_dbg(FYI, "found in the pending open list\n");
641 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
642 			 lease_state);
643 
644 		open->oplock = lease_state;
645 	}
646 
647 	return found;
648 }
649 
650 static bool
651 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
652 {
653 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
654 	struct TCP_Server_Info *pserver;
655 	struct cifs_ses *ses;
656 	struct cifs_tcon *tcon;
657 	struct cifs_pending_open *open;
658 
659 	/* Trace receipt of lease break request from server */
660 	trace_smb3_lease_break_enter(le32_to_cpu(rsp->CurrentLeaseState),
661 		le32_to_cpu(rsp->Flags),
662 		le16_to_cpu(rsp->Epoch),
663 		le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
664 		le64_to_cpu(rsp->hdr.SessionId),
665 		*((u64 *)rsp->LeaseKey),
666 		*((u64 *)&rsp->LeaseKey[8]));
667 
668 	cifs_dbg(FYI, "Checking for lease break\n");
669 
670 	/* If server is a channel, select the primary channel */
671 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
672 
673 	/* look up tcon based on tid & uid */
674 	spin_lock(&cifs_tcp_ses_lock);
675 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
676 		if (cifs_ses_exiting(ses))
677 			continue;
678 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
679 			spin_lock(&tcon->open_file_lock);
680 			cifs_stats_inc(
681 				       &tcon->stats.cifs_stats.num_oplock_brks);
682 			if (smb2_tcon_has_lease(tcon, rsp)) {
683 				spin_unlock(&tcon->open_file_lock);
684 				spin_unlock(&cifs_tcp_ses_lock);
685 				return true;
686 			}
687 			open = smb2_tcon_find_pending_open_lease(tcon,
688 								 rsp);
689 			if (open) {
690 				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
691 				struct tcon_link *tlink;
692 
693 				tlink = cifs_get_tlink(open->tlink);
694 				memcpy(lease_key, open->lease_key,
695 				       SMB2_LEASE_KEY_SIZE);
696 				spin_unlock(&tcon->open_file_lock);
697 				spin_unlock(&cifs_tcp_ses_lock);
698 				smb2_queue_pending_open_break(tlink,
699 							      lease_key,
700 							      rsp->NewLeaseState);
701 				return true;
702 			}
703 			spin_unlock(&tcon->open_file_lock);
704 
705 			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
706 				spin_unlock(&cifs_tcp_ses_lock);
707 				return true;
708 			}
709 		}
710 	}
711 	spin_unlock(&cifs_tcp_ses_lock);
712 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
713 	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
714 					   le32_to_cpu(rsp->Flags),
715 					   le16_to_cpu(rsp->Epoch),
716 					   le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
717 					   le64_to_cpu(rsp->hdr.SessionId),
718 					   *((u64 *)rsp->LeaseKey),
719 					   *((u64 *)&rsp->LeaseKey[8]));
720 
721 	return false;
722 }
723 
724 bool
725 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
726 {
727 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
728 	struct TCP_Server_Info *pserver;
729 	struct cifs_ses *ses;
730 	struct cifs_tcon *tcon;
731 	struct cifsInodeInfo *cinode;
732 	struct cifsFileInfo *cfile;
733 
734 	cifs_dbg(FYI, "Checking for oplock break\n");
735 
736 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
737 		return false;
738 
739 	if (rsp->StructureSize !=
740 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
741 		if (le16_to_cpu(rsp->StructureSize) == 44)
742 			return smb2_is_valid_lease_break(buffer, server);
743 		else
744 			return false;
745 	}
746 
747 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
748 
749 	/* If server is a channel, select the primary channel */
750 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
751 
752 	/* look up tcon based on tid & uid */
753 	spin_lock(&cifs_tcp_ses_lock);
754 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
755 		if (cifs_ses_exiting(ses))
756 			continue;
757 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
758 
759 			spin_lock(&tcon->open_file_lock);
760 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
761 				if (rsp->PersistentFid !=
762 				    cfile->fid.persistent_fid ||
763 				    rsp->VolatileFid !=
764 				    cfile->fid.volatile_fid)
765 					continue;
766 
767 				cifs_dbg(FYI, "file id match, oplock break\n");
768 				cifs_stats_inc(
769 				    &tcon->stats.cifs_stats.num_oplock_brks);
770 				cinode = CIFS_I(d_inode(cfile->dentry));
771 				spin_lock(&cfile->file_info_lock);
772 				if (!CIFS_CACHE_WRITE(cinode) &&
773 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
774 					cfile->oplock_break_cancelled = true;
775 				else
776 					cfile->oplock_break_cancelled = false;
777 
778 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
779 					&cinode->flags);
780 
781 				cfile->oplock_epoch = 0;
782 				cfile->oplock_level = rsp->OplockLevel;
783 
784 				spin_unlock(&cfile->file_info_lock);
785 
786 				cifs_queue_oplock_break(cfile);
787 
788 				spin_unlock(&tcon->open_file_lock);
789 				spin_unlock(&cifs_tcp_ses_lock);
790 				return true;
791 			}
792 			spin_unlock(&tcon->open_file_lock);
793 		}
794 	}
795 	spin_unlock(&cifs_tcp_ses_lock);
796 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
797 	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
798 				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
799 				  le64_to_cpu(rsp->hdr.SessionId));
800 
801 	return true;
802 }
803 
804 void
805 smb2_cancelled_close_fid(struct work_struct *work)
806 {
807 	struct close_cancelled_open *cancelled = container_of(work,
808 					struct close_cancelled_open, work);
809 	struct cifs_tcon *tcon = cancelled->tcon;
810 	int rc;
811 
812 	if (cancelled->mid)
813 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
814 			      cancelled->mid);
815 	else
816 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
817 
818 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
819 			cancelled->fid.volatile_fid);
820 	if (rc)
821 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
822 
823 	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
824 	kfree(cancelled);
825 }
826 
827 /*
828  * Caller should already has an extra reference to @tcon
829  * This function is used to queue work to close a handle to prevent leaks
830  * on the server.
831  * We handle two cases. If an open was interrupted after we sent the
832  * SMB2_CREATE to the server but before we processed the reply, and second
833  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
834  */
835 static int
836 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
837 			    __u64 persistent_fid, __u64 volatile_fid)
838 {
839 	struct close_cancelled_open *cancelled;
840 
841 	cancelled = kzalloc_obj(*cancelled);
842 	if (!cancelled)
843 		return -ENOMEM;
844 
845 	cancelled->fid.persistent_fid = persistent_fid;
846 	cancelled->fid.volatile_fid = volatile_fid;
847 	cancelled->tcon = tcon;
848 	cancelled->cmd = cmd;
849 	cancelled->mid = mid;
850 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
851 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
852 
853 	return 0;
854 }
855 
856 int
857 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
858 			    __u64 volatile_fid)
859 {
860 	int rc;
861 
862 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
863 	spin_lock(&tcon->tc_lock);
864 	if (tcon->tc_count <= 0) {
865 		struct TCP_Server_Info *server = NULL;
866 
867 		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
868 				    netfs_trace_tcon_ref_see_cancelled_close);
869 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
870 		spin_unlock(&tcon->tc_lock);
871 
872 		if (tcon->ses) {
873 			server = tcon->ses->server;
874 			cifs_server_dbg(FYI,
875 					"tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
876 					tcon->tid, persistent_fid, volatile_fid);
877 		}
878 
879 		return 0;
880 	}
881 	tcon->tc_count++;
882 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
883 			    netfs_trace_tcon_ref_get_cancelled_close);
884 	spin_unlock(&tcon->tc_lock);
885 
886 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
887 					 persistent_fid, volatile_fid);
888 	if (rc)
889 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
890 
891 	return rc;
892 }
893 
894 int
895 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
896 {
897 	struct smb2_hdr *hdr = mid->resp_buf;
898 	struct smb2_create_rsp *rsp = mid->resp_buf;
899 	struct cifs_tcon *tcon;
900 	int rc;
901 
902 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
903 	    hdr->Status != STATUS_SUCCESS)
904 		return 0;
905 
906 	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
907 				  le32_to_cpu(hdr->Id.SyncId.TreeId));
908 	if (!tcon)
909 		return -ENOENT;
910 
911 	rc = __smb2_handle_cancelled_cmd(tcon,
912 					 le16_to_cpu(hdr->Command),
913 					 le64_to_cpu(hdr->MessageId),
914 					 rsp->PersistentFileId,
915 					 rsp->VolatileFileId);
916 	if (rc)
917 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
918 
919 	return rc;
920 }
921 
922 /**
923  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
924  *
925  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
926  * SMB2 header.
927  *
928  * @ses:	server session structure
929  * @server:	pointer to server info
930  * @iov:	array containing the SMB request we will send to the server
931  * @nvec:	number of array entries for the iov
932  */
933 void
934 smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
935 			   struct kvec *iov, int nvec)
936 {
937 	int i;
938 	struct smb2_hdr *hdr;
939 	struct sha512_ctx sha_ctx;
940 
941 	hdr = (struct smb2_hdr *)iov[0].iov_base;
942 	/* neg prot are always taken */
943 	if (hdr->Command == SMB2_NEGOTIATE)
944 		goto ok;
945 
946 	/*
947 	 * If we process a command which wasn't a negprot it means the
948 	 * neg prot was already done, so the server dialect was set
949 	 * and we can test it. Preauth requires 3.1.1 for now.
950 	 */
951 	if (server->dialect != SMB311_PROT_ID)
952 		return;
953 
954 	if (hdr->Command != SMB2_SESSION_SETUP)
955 		return;
956 
957 	/* skip last sess setup response */
958 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
959 	    && (hdr->Status == NT_STATUS_OK
960 		|| (hdr->Status !=
961 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
962 		return;
963 
964 ok:
965 	sha512_init(&sha_ctx);
966 	sha512_update(&sha_ctx, ses->preauth_sha_hash, SMB2_PREAUTH_HASH_SIZE);
967 	for (i = 0; i < nvec; i++)
968 		sha512_update(&sha_ctx, iov[i].iov_base, iov[i].iov_len);
969 	sha512_final(&sha_ctx, ses->preauth_sha_hash);
970 }
971