xref: /linux/fs/smb/client/smb2misc.c (revision d62b8d236fab503c6fec1d3e9a38bea71feaca20)
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 int
23 check_smb2_hdr(struct smb2_hdr *shdr, __u64 mid)
24 {
25 	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
26 
27 	/*
28 	 * Make sure that this really is an SMB, that it is a response,
29 	 * and that the message ids match.
30 	 */
31 	if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
32 	    (mid == wire_mid)) {
33 		if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
34 			return 0;
35 		else {
36 			/* only one valid case where server sends us request */
37 			if (shdr->Command == SMB2_OPLOCK_BREAK)
38 				return 0;
39 			else
40 				cifs_dbg(VFS, "Received Request not response\n");
41 		}
42 	} else { /* bad signature or mid */
43 		if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
44 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
45 				 le32_to_cpu(shdr->ProtocolId));
46 		if (mid != wire_mid)
47 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
48 				 mid, wire_mid);
49 	}
50 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
51 	return 1;
52 }
53 
54 /*
55  *  The following table defines the expected "StructureSize" of SMB2 responses
56  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
57  *
58  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
59  *  indexed by command in host byte order
60  */
61 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
62 	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
63 	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
64 	/* SMB2_LOGOFF */ cpu_to_le16(4),
65 	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
66 	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
67 	/* SMB2_CREATE */ cpu_to_le16(89),
68 	/* SMB2_CLOSE */ cpu_to_le16(60),
69 	/* SMB2_FLUSH */ cpu_to_le16(4),
70 	/* SMB2_READ */ cpu_to_le16(17),
71 	/* SMB2_WRITE */ cpu_to_le16(17),
72 	/* SMB2_LOCK */ cpu_to_le16(4),
73 	/* SMB2_IOCTL */ cpu_to_le16(49),
74 	/* BB CHECK this ... not listed in documentation */
75 	/* SMB2_CANCEL */ cpu_to_le16(0),
76 	/* SMB2_ECHO */ cpu_to_le16(4),
77 	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
78 	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
79 	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
80 	/* SMB2_SET_INFO */ cpu_to_le16(2),
81 	/* BB FIXME can also be 44 for lease break */
82 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
83 };
84 
85 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_hdr) + sizeof(struct smb2_negotiate_rsp))
86 
87 static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len,
88 			      __u32 non_ctxlen)
89 {
90 	__u16 neg_count;
91 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
92 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
93 
94 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
95 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
96 	if ((neg_count == 0) ||
97 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
98 		return 0;
99 
100 	/*
101 	 * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
102 	 * which security mechanisms the server supports) make sure that
103 	 * the negotiate contexts start after it
104 	 */
105 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
106 	/*
107 	 * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
108 	 * and the latter is 1 byte bigger than the fix-sized area of the
109 	 * NEGOTIATE response
110 	 */
111 	if (nc_offset + 1 < non_ctxlen) {
112 		pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
113 		return 0;
114 	} else if (nc_offset + 1 == non_ctxlen) {
115 		cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
116 		size_of_pad_before_neg_ctxts = 0;
117 	} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
118 		/* has padding, but no SPNEGO blob */
119 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
120 	else
121 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
122 
123 	/* Verify that at least minimal negotiate contexts fit within frame */
124 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
125 		pr_warn_once("negotiate context goes beyond end\n");
126 		return 0;
127 	}
128 
129 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
130 		len - nc_offset, size_of_pad_before_neg_ctxts);
131 
132 	/* length of negcontexts including pad from end of sec blob to them */
133 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
134 }
135 
136 int
137 smb2_check_message(char *buf, unsigned int pdu_len, unsigned int len,
138 		   struct TCP_Server_Info *server)
139 {
140 	struct TCP_Server_Info *pserver;
141 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
142 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
143 	int hdr_size = sizeof(struct smb2_hdr);
144 	int pdu_size = sizeof(struct smb2_pdu);
145 	int command;
146 	__u32 calc_len; /* calculated length */
147 	__u64 mid;
148 
149 	/* If server is a channel, select the primary channel */
150 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
151 
152 	/*
153 	 * Add function to do table lookup of StructureSize by command
154 	 * ie Validate the wct via smb2_struct_sizes table above
155 	 */
156 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
157 		struct smb2_transform_hdr *thdr =
158 			(struct smb2_transform_hdr *)buf;
159 		struct cifs_ses *ses = NULL;
160 		struct cifs_ses *iter;
161 
162 		/* decrypt frame now that it is completely read in */
163 		spin_lock(&cifs_tcp_ses_lock);
164 		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
165 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
166 				ses = iter;
167 				break;
168 			}
169 		}
170 		spin_unlock(&cifs_tcp_ses_lock);
171 		if (!ses) {
172 			cifs_dbg(VFS, "no decryption - session id not found\n");
173 			return 1;
174 		}
175 	}
176 
177 	mid = le64_to_cpu(shdr->MessageId);
178 	if (check_smb2_hdr(shdr, mid))
179 		return 1;
180 
181 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
182 		cifs_dbg(VFS, "Invalid structure size %u\n",
183 			 le16_to_cpu(shdr->StructureSize));
184 		return 1;
185 	}
186 
187 	command = le16_to_cpu(shdr->Command);
188 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
189 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
190 		return 1;
191 	}
192 
193 	if (len < pdu_size) {
194 		if ((len >= hdr_size)
195 		    && (shdr->Status != 0)) {
196 			pdu->StructureSize2 = 0;
197 			/*
198 			 * As with SMB/CIFS, on some error cases servers may
199 			 * not return wct properly
200 			 */
201 			return 0;
202 		} else {
203 			cifs_dbg(VFS, "Length less than SMB header size\n");
204 		}
205 		return 1;
206 	}
207 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
208 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
209 			 mid);
210 		return 1;
211 	}
212 
213 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
214 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
215 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
216 			/* error packets have 9 byte structure size */
217 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
218 				 le16_to_cpu(pdu->StructureSize2), command);
219 			return 1;
220 		} else if (command == SMB2_OPLOCK_BREAK_HE
221 			   && (shdr->Status == 0)
222 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
223 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
224 			/* special case for SMB2.1 lease break message */
225 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
226 				 le16_to_cpu(pdu->StructureSize2));
227 			return 1;
228 		}
229 	}
230 
231 	calc_len = smb2_calc_size(buf);
232 
233 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
234 	 * be 0, and not a real miscalculation */
235 	if (command == SMB2_IOCTL_HE && calc_len == 0)
236 		return 0;
237 
238 	if (command == SMB2_NEGOTIATE_HE)
239 		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
240 
241 	if (len != calc_len) {
242 		/* create failed on symlink */
243 		if (command == SMB2_CREATE_HE &&
244 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK &&
245 		    len > calc_len)
246 			return 0;
247 		/* Windows 7 server returns 24 bytes more */
248 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
249 			return 0;
250 		/* server can return one byte more due to implied bcc[0] */
251 		if (calc_len == len + 1)
252 			return 0;
253 
254 		/*
255 		 * Some windows servers (win2016) will pad also the final
256 		 * PDU in a compound to 8 bytes.
257 		 */
258 		if (ALIGN(calc_len, 8) == len)
259 			return 0;
260 
261 		/*
262 		 * MacOS server pads after SMB2.1 write response with 3 bytes
263 		 * of junk. Other servers match RFC1001 len to actual
264 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
265 		 * Some windows servers also pad up to 8 bytes when compounding.
266 		 */
267 		if (calc_len < len)
268 			return 0;
269 
270 		/* Only log a message if len was really miscalculated */
271 		if (unlikely(cifsFYI))
272 			cifs_dbg(FYI, "Server response too short: calculated "
273 				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
274 				 calc_len, len, command, mid);
275 		else
276 			pr_warn("Server response too short: calculated length "
277 				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
278 				calc_len, len, command, mid);
279 
280 		return 1;
281 	}
282 	return 0;
283 }
284 
285 /*
286  * The size of the variable area depends on the offset and length fields
287  * located in different fields for various SMB2 responses. SMB2 responses
288  * with no variable length info, show an offset of zero for the offset field.
289  */
290 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
291 	/* SMB2_NEGOTIATE */ true,
292 	/* SMB2_SESSION_SETUP */ true,
293 	/* SMB2_LOGOFF */ false,
294 	/* SMB2_TREE_CONNECT */	false,
295 	/* SMB2_TREE_DISCONNECT */ false,
296 	/* SMB2_CREATE */ true,
297 	/* SMB2_CLOSE */ false,
298 	/* SMB2_FLUSH */ false,
299 	/* SMB2_READ */	true,
300 	/* SMB2_WRITE */ false,
301 	/* SMB2_LOCK */	false,
302 	/* SMB2_IOCTL */ true,
303 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
304 	/* SMB2_ECHO */ false,
305 	/* SMB2_QUERY_DIRECTORY */ true,
306 	/* SMB2_CHANGE_NOTIFY */ true,
307 	/* SMB2_QUERY_INFO */ true,
308 	/* SMB2_SET_INFO */ false,
309 	/* SMB2_OPLOCK_BREAK */ false
310 };
311 
312 /*
313  * Returns the pointer to the beginning of the data area. Length of the data
314  * area and the offset to it (from the beginning of the smb are also returned.
315  */
316 char *
317 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
318 {
319 	const int max_off = 4096;
320 	const int max_len = 128 * 1024;
321 
322 	*off = 0;
323 	*len = 0;
324 
325 	/* error responses do not have data area */
326 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
327 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
328 						SMB2_ERROR_STRUCTURE_SIZE2_LE)
329 		return NULL;
330 
331 	/*
332 	 * Following commands have data areas so we have to get the location
333 	 * of the data buffer offset and data buffer length for the particular
334 	 * command.
335 	 */
336 	switch (shdr->Command) {
337 	case SMB2_NEGOTIATE:
338 		*off = le16_to_cpu(
339 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
340 		*len = le16_to_cpu(
341 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
342 		break;
343 	case SMB2_SESSION_SETUP:
344 		*off = le16_to_cpu(
345 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
346 		*len = le16_to_cpu(
347 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
348 		break;
349 	case SMB2_CREATE:
350 		*off = le32_to_cpu(
351 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
352 		*len = le32_to_cpu(
353 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
354 		break;
355 	case SMB2_QUERY_INFO:
356 		*off = le16_to_cpu(
357 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
358 		*len = le32_to_cpu(
359 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
360 		break;
361 	case SMB2_READ:
362 		/* TODO: is this a bug ? */
363 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
364 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
365 		break;
366 	case SMB2_QUERY_DIRECTORY:
367 		*off = le16_to_cpu(
368 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
369 		*len = le32_to_cpu(
370 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
371 		break;
372 	case SMB2_IOCTL:
373 		*off = le32_to_cpu(
374 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
375 		*len = le32_to_cpu(
376 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
377 		break;
378 	case SMB2_CHANGE_NOTIFY:
379 		*off = le16_to_cpu(
380 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
381 		*len = le32_to_cpu(
382 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
383 		break;
384 	default:
385 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
386 		break;
387 	}
388 
389 	/*
390 	 * Invalid length or offset probably means data area is invalid, but
391 	 * we have little choice but to ignore the data area in this case.
392 	 */
393 	if (unlikely(*off < 0 || *off > max_off ||
394 		     *len < 0 || *len > max_len)) {
395 		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
396 			 __func__, *off, *len);
397 		*off = 0;
398 		*len = 0;
399 	} else if (*off == 0) {
400 		*len = 0;
401 	}
402 
403 	/* return pointer to beginning of data area, ie offset from SMB start */
404 	if (*off > 0 && *len > 0)
405 		return (char *)shdr + *off;
406 	return NULL;
407 }
408 
409 /*
410  * Calculate the size of the SMB message based on the fixed header
411  * portion, the number of word parameters and the data portion of the message.
412  */
413 unsigned int
414 smb2_calc_size(void *buf)
415 {
416 	struct smb2_pdu *pdu = buf;
417 	struct smb2_hdr *shdr = &pdu->hdr;
418 	int offset; /* the offset from the beginning of SMB to data area */
419 	int data_length; /* the length of the variable length data area */
420 	/* Structure Size has already been checked to make sure it is 64 */
421 	int len = le16_to_cpu(shdr->StructureSize);
422 
423 	/*
424 	 * StructureSize2, ie length of fixed parameter area has already
425 	 * been checked to make sure it is the correct length.
426 	 */
427 	len += le16_to_cpu(pdu->StructureSize2);
428 
429 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
430 		goto calc_size_exit;
431 
432 	smb2_get_data_area_len(&offset, &data_length, shdr);
433 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
434 
435 	if (data_length > 0) {
436 		/*
437 		 * Check to make sure that data area begins after fixed area,
438 		 * Note that last byte of the fixed area is part of data area
439 		 * for some commands, typically those with odd StructureSize,
440 		 * so we must add one to the calculation.
441 		 */
442 		if (offset + 1 < len) {
443 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
444 				 offset + 1, len);
445 			data_length = 0;
446 		} else {
447 			len = offset + data_length;
448 		}
449 	}
450 calc_size_exit:
451 	cifs_dbg(FYI, "SMB2 len %d\n", len);
452 	return len;
453 }
454 
455 /* Note: caller must free return buffer */
456 __le16 *
457 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
458 {
459 	const char *start_of_path;
460 	int len;
461 
462 	/* Windows doesn't allow paths beginning with \ */
463 	if (from[0] == '\\')
464 		start_of_path = from + 1;
465 
466 	/* SMB311 POSIX extensions paths do not include leading slash */
467 	else if (cifs_sb_master_tlink(cifs_sb) &&
468 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
469 		 (from[0] == '/')) {
470 		start_of_path = from + 1;
471 	} else
472 		start_of_path = from;
473 
474 	return cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
475 				     cifs_sb->local_nls, cifs_remap(cifs_sb));
476 }
477 
478 __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode, unsigned int oplock)
479 {
480 	unsigned int sbflags = cifs_sb_flags(CIFS_SB(cinode));
481 	__le32 lease = 0;
482 
483 	if ((oplock & CIFS_CACHE_WRITE_FLG) || (sbflags & CIFS_MOUNT_RW_CACHE))
484 		lease |= SMB2_LEASE_WRITE_CACHING_LE;
485 	if (oplock & CIFS_CACHE_HANDLE_FLG)
486 		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
487 	if ((oplock & CIFS_CACHE_READ_FLG) || (sbflags & CIFS_MOUNT_RO_CACHE))
488 		lease |= SMB2_LEASE_READ_CACHING_LE;
489 	return lease;
490 }
491 
492 struct smb2_lease_break_work {
493 	struct work_struct lease_break;
494 	struct tcon_link *tlink;
495 	__u8 lease_key[16];
496 	__le32 lease_state;
497 };
498 
499 static void
500 cifs_ses_oplock_break(struct work_struct *work)
501 {
502 	struct smb2_lease_break_work *lw = container_of(work,
503 				struct smb2_lease_break_work, lease_break);
504 	int rc = 0;
505 
506 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
507 			      lw->lease_state);
508 
509 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
510 	cifs_put_tlink(lw->tlink);
511 	kfree(lw);
512 }
513 
514 static void
515 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
516 			      __le32 new_lease_state)
517 {
518 	struct smb2_lease_break_work *lw;
519 
520 	lw = kmalloc_obj(struct smb2_lease_break_work);
521 	if (!lw) {
522 		cifs_put_tlink(tlink);
523 		return;
524 	}
525 
526 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
527 	lw->tlink = tlink;
528 	lw->lease_state = new_lease_state;
529 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
530 	queue_work(cifsiod_wq, &lw->lease_break);
531 }
532 
533 static bool
534 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
535 {
536 	__u8 lease_state;
537 	struct cifsFileInfo *cfile;
538 	struct cifsInodeInfo *cinode;
539 	int ack_req = le32_to_cpu(rsp->Flags &
540 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
541 
542 	lease_state = le32_to_cpu(rsp->NewLeaseState);
543 
544 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
545 		cinode = CIFS_I(d_inode(cfile->dentry));
546 
547 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
548 							SMB2_LEASE_KEY_SIZE))
549 			continue;
550 
551 		cifs_dbg(FYI, "found in the open list\n");
552 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
553 			 lease_state);
554 
555 		if (ack_req)
556 			cfile->oplock_break_cancelled = false;
557 		else
558 			cfile->oplock_break_cancelled = true;
559 
560 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
561 
562 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
563 		cfile->oplock_level = lease_state;
564 
565 		cifs_queue_oplock_break(cfile);
566 		return true;
567 	}
568 
569 	return false;
570 }
571 
572 static struct cifs_pending_open *
573 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
574 				  struct smb2_lease_break *rsp)
575 {
576 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
577 	int ack_req = le32_to_cpu(rsp->Flags &
578 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
579 	struct cifs_pending_open *open;
580 	struct cifs_pending_open *found = NULL;
581 
582 	list_for_each_entry(open, &tcon->pending_opens, olist) {
583 		if (memcmp(open->lease_key, rsp->LeaseKey,
584 			   SMB2_LEASE_KEY_SIZE))
585 			continue;
586 
587 		if (!found && ack_req) {
588 			found = open;
589 		}
590 
591 		cifs_dbg(FYI, "found in the pending open list\n");
592 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
593 			 lease_state);
594 
595 		open->oplock = lease_state;
596 	}
597 
598 	return found;
599 }
600 
601 static bool
602 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
603 {
604 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
605 	struct TCP_Server_Info *pserver;
606 	struct cifs_ses *ses;
607 	struct cifs_tcon *tcon;
608 	struct cifs_pending_open *open;
609 
610 	/* Trace receipt of lease break request from server */
611 	trace_smb3_lease_break_enter(le32_to_cpu(rsp->CurrentLeaseState),
612 		le32_to_cpu(rsp->Flags),
613 		le16_to_cpu(rsp->Epoch),
614 		le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
615 		le64_to_cpu(rsp->hdr.SessionId),
616 		*((u64 *)rsp->LeaseKey),
617 		*((u64 *)&rsp->LeaseKey[8]));
618 
619 	cifs_dbg(FYI, "Checking for lease break\n");
620 
621 	/* If server is a channel, select the primary channel */
622 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
623 
624 	/* look up tcon based on tid & uid */
625 	spin_lock(&cifs_tcp_ses_lock);
626 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
627 		if (cifs_ses_exiting(ses))
628 			continue;
629 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
630 			spin_lock(&tcon->open_file_lock);
631 			cifs_stats_inc(
632 				       &tcon->stats.cifs_stats.num_oplock_brks);
633 			if (smb2_tcon_has_lease(tcon, rsp)) {
634 				spin_unlock(&tcon->open_file_lock);
635 				spin_unlock(&cifs_tcp_ses_lock);
636 				return true;
637 			}
638 			open = smb2_tcon_find_pending_open_lease(tcon,
639 								 rsp);
640 			if (open) {
641 				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
642 				struct tcon_link *tlink;
643 
644 				tlink = cifs_get_tlink(open->tlink);
645 				memcpy(lease_key, open->lease_key,
646 				       SMB2_LEASE_KEY_SIZE);
647 				spin_unlock(&tcon->open_file_lock);
648 				spin_unlock(&cifs_tcp_ses_lock);
649 				smb2_queue_pending_open_break(tlink,
650 							      lease_key,
651 							      rsp->NewLeaseState);
652 				return true;
653 			}
654 			spin_unlock(&tcon->open_file_lock);
655 
656 			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
657 				spin_unlock(&cifs_tcp_ses_lock);
658 				return true;
659 			}
660 		}
661 	}
662 	spin_unlock(&cifs_tcp_ses_lock);
663 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
664 	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
665 					   le32_to_cpu(rsp->Flags),
666 					   le16_to_cpu(rsp->Epoch),
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 = 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 		if (cifs_ses_exiting(ses))
707 			continue;
708 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
709 
710 			spin_lock(&tcon->open_file_lock);
711 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
712 				if (rsp->PersistentFid !=
713 				    cfile->fid.persistent_fid ||
714 				    rsp->VolatileFid !=
715 				    cfile->fid.volatile_fid)
716 					continue;
717 
718 				cifs_dbg(FYI, "file id match, oplock break\n");
719 				cifs_stats_inc(
720 				    &tcon->stats.cifs_stats.num_oplock_brks);
721 				cinode = CIFS_I(d_inode(cfile->dentry));
722 				spin_lock(&cfile->file_info_lock);
723 				if (!CIFS_CACHE_WRITE(cinode) &&
724 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
725 					cfile->oplock_break_cancelled = true;
726 				else
727 					cfile->oplock_break_cancelled = false;
728 
729 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
730 					&cinode->flags);
731 
732 				cfile->oplock_epoch = 0;
733 				cfile->oplock_level = rsp->OplockLevel;
734 
735 				spin_unlock(&cfile->file_info_lock);
736 
737 				cifs_queue_oplock_break(cfile);
738 
739 				spin_unlock(&tcon->open_file_lock);
740 				spin_unlock(&cifs_tcp_ses_lock);
741 				return true;
742 			}
743 			spin_unlock(&tcon->open_file_lock);
744 		}
745 	}
746 	spin_unlock(&cifs_tcp_ses_lock);
747 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
748 	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
749 				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
750 				  le64_to_cpu(rsp->hdr.SessionId));
751 
752 	return true;
753 }
754 
755 void
756 smb2_cancelled_close_fid(struct work_struct *work)
757 {
758 	struct close_cancelled_open *cancelled = container_of(work,
759 					struct close_cancelled_open, work);
760 	struct cifs_tcon *tcon = cancelled->tcon;
761 	int rc;
762 
763 	if (cancelled->mid)
764 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
765 			      cancelled->mid);
766 	else
767 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
768 
769 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
770 			cancelled->fid.volatile_fid);
771 	if (rc)
772 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
773 
774 	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
775 	kfree(cancelled);
776 }
777 
778 /*
779  * Caller should already has an extra reference to @tcon
780  * This function is used to queue work to close a handle to prevent leaks
781  * on the server.
782  * We handle two cases. If an open was interrupted after we sent the
783  * SMB2_CREATE to the server but before we processed the reply, and second
784  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
785  */
786 static int
787 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
788 			    __u64 persistent_fid, __u64 volatile_fid)
789 {
790 	struct close_cancelled_open *cancelled;
791 
792 	cancelled = kzalloc_obj(*cancelled);
793 	if (!cancelled)
794 		return -ENOMEM;
795 
796 	cancelled->fid.persistent_fid = persistent_fid;
797 	cancelled->fid.volatile_fid = volatile_fid;
798 	cancelled->tcon = tcon;
799 	cancelled->cmd = cmd;
800 	cancelled->mid = mid;
801 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
802 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
803 
804 	return 0;
805 }
806 
807 int
808 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
809 			    __u64 volatile_fid)
810 {
811 	int rc;
812 
813 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
814 	spin_lock(&tcon->tc_lock);
815 	if (tcon->tc_count <= 0) {
816 		struct TCP_Server_Info *server = NULL;
817 
818 		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
819 				    netfs_trace_tcon_ref_see_cancelled_close);
820 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
821 		spin_unlock(&tcon->tc_lock);
822 
823 		if (tcon->ses) {
824 			server = tcon->ses->server;
825 			cifs_server_dbg(FYI,
826 					"tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
827 					tcon->tid, persistent_fid, volatile_fid);
828 		}
829 
830 		return 0;
831 	}
832 	tcon->tc_count++;
833 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
834 			    netfs_trace_tcon_ref_get_cancelled_close);
835 	spin_unlock(&tcon->tc_lock);
836 
837 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
838 					 persistent_fid, volatile_fid);
839 	if (rc)
840 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
841 
842 	return rc;
843 }
844 
845 int
846 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
847 {
848 	struct smb2_hdr *hdr = mid->resp_buf;
849 	struct smb2_create_rsp *rsp = mid->resp_buf;
850 	struct cifs_tcon *tcon;
851 	int rc;
852 
853 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
854 	    hdr->Status != STATUS_SUCCESS)
855 		return 0;
856 
857 	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
858 				  le32_to_cpu(hdr->Id.SyncId.TreeId));
859 	if (!tcon)
860 		return -ENOENT;
861 
862 	rc = __smb2_handle_cancelled_cmd(tcon,
863 					 le16_to_cpu(hdr->Command),
864 					 le64_to_cpu(hdr->MessageId),
865 					 rsp->PersistentFileId,
866 					 rsp->VolatileFileId);
867 	if (rc)
868 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
869 
870 	return rc;
871 }
872 
873 /**
874  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
875  *
876  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
877  * SMB2 header.
878  *
879  * @ses:	server session structure
880  * @server:	pointer to server info
881  * @iov:	array containing the SMB request we will send to the server
882  * @nvec:	number of array entries for the iov
883  */
884 void
885 smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
886 			   struct kvec *iov, int nvec)
887 {
888 	int i;
889 	struct smb2_hdr *hdr;
890 	struct sha512_ctx sha_ctx;
891 
892 	hdr = (struct smb2_hdr *)iov[0].iov_base;
893 	/* neg prot are always taken */
894 	if (hdr->Command == SMB2_NEGOTIATE)
895 		goto ok;
896 
897 	/*
898 	 * If we process a command which wasn't a negprot it means the
899 	 * neg prot was already done, so the server dialect was set
900 	 * and we can test it. Preauth requires 3.1.1 for now.
901 	 */
902 	if (server->dialect != SMB311_PROT_ID)
903 		return;
904 
905 	if (hdr->Command != SMB2_SESSION_SETUP)
906 		return;
907 
908 	/* skip last sess setup response */
909 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
910 	    && (hdr->Status == NT_STATUS_OK
911 		|| (hdr->Status !=
912 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
913 		return;
914 
915 ok:
916 	sha512_init(&sha_ctx);
917 	sha512_update(&sha_ctx, ses->preauth_sha_hash, SMB2_PREAUTH_HASH_SIZE);
918 	for (i = 0; i < nvec; i++)
919 		sha512_update(&sha_ctx, iov[i].iov_base, iov[i].iov_len);
920 	sha512_final(&sha_ctx, ses->preauth_sha_hash);
921 }
922