xref: /linux/fs/smb/client/smb2misc.c (revision df34ecc52526480a1a4bb78bc75bfb009c6076a4)
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 
24 static int
25 check_smb2_hdr(struct smb2_hdr *shdr, __u64 mid)
26 {
27 	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
28 
29 	/*
30 	 * Make sure that this really is an SMB, that it is a response,
31 	 * and that the message ids match.
32 	 */
33 	if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
34 	    (mid == wire_mid)) {
35 		if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
36 			return 0;
37 		else {
38 			/* only one valid case where server sends us request */
39 			if (shdr->Command == SMB2_OPLOCK_BREAK)
40 				return 0;
41 			else
42 				cifs_dbg(VFS, "Received Request not response\n");
43 		}
44 	} else { /* bad signature or mid */
45 		if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
46 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
47 				 le32_to_cpu(shdr->ProtocolId));
48 		if (mid != wire_mid)
49 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
50 				 mid, wire_mid);
51 	}
52 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
53 	return 1;
54 }
55 
56 /*
57  *  The following table defines the expected "StructureSize" of SMB2 responses
58  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
59  *
60  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
61  *  indexed by command in host byte order
62  */
63 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
64 	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
65 	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
66 	/* SMB2_LOGOFF */ cpu_to_le16(4),
67 	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
68 	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
69 	/* SMB2_CREATE */ cpu_to_le16(89),
70 	/* SMB2_CLOSE */ cpu_to_le16(60),
71 	/* SMB2_FLUSH */ cpu_to_le16(4),
72 	/* SMB2_READ */ cpu_to_le16(17),
73 	/* SMB2_WRITE */ cpu_to_le16(17),
74 	/* SMB2_LOCK */ cpu_to_le16(4),
75 	/* SMB2_IOCTL */ cpu_to_le16(49),
76 	/* BB CHECK this ... not listed in documentation */
77 	/* SMB2_CANCEL */ cpu_to_le16(0),
78 	/* SMB2_ECHO */ cpu_to_le16(4),
79 	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
80 	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
81 	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
82 	/* SMB2_SET_INFO */ cpu_to_le16(2),
83 	/* BB FIXME can also be 44 for lease break */
84 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
85 };
86 
87 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_hdr) + sizeof(struct smb2_negotiate_rsp))
88 
89 static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len,
90 			      __u32 non_ctxlen)
91 {
92 	__u16 neg_count;
93 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
94 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
95 
96 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
97 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
98 	if ((neg_count == 0) ||
99 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
100 		return 0;
101 
102 	/*
103 	 * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
104 	 * which security mechanisms the server supports) make sure that
105 	 * the negotiate contexts start after it
106 	 */
107 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
108 	/*
109 	 * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
110 	 * and the latter is 1 byte bigger than the fix-sized area of the
111 	 * NEGOTIATE response
112 	 */
113 	if (nc_offset + 1 < non_ctxlen) {
114 		pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
115 		return 0;
116 	} else if (nc_offset + 1 == non_ctxlen) {
117 		cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
118 		size_of_pad_before_neg_ctxts = 0;
119 	} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
120 		/* has padding, but no SPNEGO blob */
121 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
122 	else
123 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
124 
125 	/* Verify that at least minimal negotiate contexts fit within frame */
126 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
127 		pr_warn_once("negotiate context goes beyond end\n");
128 		return 0;
129 	}
130 
131 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
132 		len - nc_offset, size_of_pad_before_neg_ctxts);
133 
134 	/* length of negcontexts including pad from end of sec blob to them */
135 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
136 }
137 
138 int
139 smb2_check_message(char *buf, unsigned int pdu_len, unsigned int len,
140 		   struct TCP_Server_Info *server)
141 {
142 	struct TCP_Server_Info *pserver;
143 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
144 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
145 	int hdr_size = sizeof(struct smb2_hdr);
146 	int pdu_size = sizeof(struct smb2_pdu);
147 	int command;
148 	__u32 calc_len; /* calculated length */
149 	__u64 mid;
150 	bool have_data;
151 
152 	/* If server is a channel, select the primary channel */
153 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
154 
155 	/*
156 	 * Add function to do table lookup of StructureSize by command
157 	 * ie Validate the wct via smb2_struct_sizes table above
158 	 */
159 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
160 		struct smb2_transform_hdr *thdr =
161 			(struct smb2_transform_hdr *)buf;
162 		struct cifs_ses *ses = NULL;
163 		struct cifs_ses *iter;
164 
165 		/* decrypt frame now that it is completely read in */
166 		spin_lock(&cifs_tcp_ses_lock);
167 		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
168 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
169 				ses = iter;
170 				break;
171 			}
172 		}
173 		spin_unlock(&cifs_tcp_ses_lock);
174 		if (!ses) {
175 			cifs_dbg(VFS, "no decryption - session id not found\n");
176 			return 1;
177 		}
178 	}
179 
180 	mid = le64_to_cpu(shdr->MessageId);
181 	if (check_smb2_hdr(shdr, mid))
182 		return 1;
183 
184 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
185 		cifs_dbg(VFS, "Invalid structure size %u\n",
186 			 le16_to_cpu(shdr->StructureSize));
187 		return 1;
188 	}
189 
190 	command = le16_to_cpu(shdr->Command);
191 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
192 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
193 		return 1;
194 	}
195 
196 	if (len < pdu_size) {
197 		if ((len >= hdr_size)
198 		    && (shdr->Status != 0)) {
199 			pdu->StructureSize2 = 0;
200 			/*
201 			 * As with SMB/CIFS, on some error cases servers may
202 			 * not return wct properly
203 			 */
204 			return 0;
205 		} else {
206 			cifs_dbg(VFS, "Length less than SMB header size\n");
207 		}
208 		return 1;
209 	}
210 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
211 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
212 			 mid);
213 		return 1;
214 	}
215 
216 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
217 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
218 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
219 			/* error packets have 9 byte structure size */
220 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
221 				 le16_to_cpu(pdu->StructureSize2), command);
222 			return 1;
223 		} else if (command == SMB2_OPLOCK_BREAK_HE
224 			   && (shdr->Status == 0)
225 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
226 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
227 			/* special case for SMB2.1 lease break message */
228 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
229 				 le16_to_cpu(pdu->StructureSize2));
230 			return 1;
231 		}
232 	}
233 
234 	have_data = false;
235 	calc_len = __smb2_calc_size(buf, &have_data);
236 
237 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
238 	 * be 0, and not a real miscalculation */
239 	if (command == SMB2_IOCTL_HE && calc_len == 0)
240 		return 0;
241 
242 	if (command == SMB2_NEGOTIATE_HE)
243 		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
244 
245 	if (len != calc_len) {
246 		/* create failed on symlink */
247 		if (command == SMB2_CREATE_HE &&
248 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK &&
249 		    len > calc_len)
250 			return 0;
251 		/* Windows 7 server returns 24 bytes more */
252 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
253 			return 0;
254 		/*
255 		 * Server can return one byte more due to implied bcc[0].
256 		 * Allow it only when there is no data area; if data_length > 0
257 		 * the +1 gap indicates an overreported data length rather than
258 		 * the bcc[0] omission.
259 		 */
260 		if (calc_len == len + 1 && !have_data)
261 			return 0;
262 
263 		/*
264 		 * Some windows servers (win2016) will pad also the final
265 		 * PDU in a compound to 8 bytes.
266 		 */
267 		if (ALIGN(calc_len, 8) == len)
268 			return 0;
269 
270 		/*
271 		 * MacOS server pads after SMB2.1 write response with 3 bytes
272 		 * of junk. Other servers match RFC1001 len to actual
273 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
274 		 * Some windows servers also pad up to 8 bytes when compounding.
275 		 */
276 		if (calc_len < len)
277 			return 0;
278 
279 		/* Only log a message if len was really miscalculated */
280 		if (unlikely(cifsFYI))
281 			cifs_dbg(FYI, "Server response too short: calculated "
282 				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
283 				 calc_len, len, command, mid);
284 		else
285 			pr_warn("Server response too short: calculated length "
286 				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
287 				calc_len, len, command, mid);
288 
289 		return 1;
290 	}
291 	return 0;
292 }
293 
294 /*
295  * The size of the variable area depends on the offset and length fields
296  * located in different fields for various SMB2 responses. SMB2 responses
297  * with no variable length info, show an offset of zero for the offset field.
298  */
299 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
300 	/* SMB2_NEGOTIATE */ true,
301 	/* SMB2_SESSION_SETUP */ true,
302 	/* SMB2_LOGOFF */ false,
303 	/* SMB2_TREE_CONNECT */	false,
304 	/* SMB2_TREE_DISCONNECT */ false,
305 	/* SMB2_CREATE */ true,
306 	/* SMB2_CLOSE */ false,
307 	/* SMB2_FLUSH */ false,
308 	/* SMB2_READ */	true,
309 	/* SMB2_WRITE */ false,
310 	/* SMB2_LOCK */	false,
311 	/* SMB2_IOCTL */ true,
312 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
313 	/* SMB2_ECHO */ false,
314 	/* SMB2_QUERY_DIRECTORY */ true,
315 	/* SMB2_CHANGE_NOTIFY */ true,
316 	/* SMB2_QUERY_INFO */ true,
317 	/* SMB2_SET_INFO */ false,
318 	/* SMB2_OPLOCK_BREAK */ false
319 };
320 
321 /*
322  * Returns the pointer to the beginning of the data area. Length of the data
323  * area and the offset to it (from the beginning of the smb are also returned.
324  */
325 char *
326 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
327 {
328 	const int max_off = 4096;
329 	const int max_len = 128 * 1024;
330 
331 	*off = 0;
332 	*len = 0;
333 
334 	/* error responses do not have data area */
335 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
336 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
337 						SMB2_ERROR_STRUCTURE_SIZE2_LE)
338 		return NULL;
339 
340 	/*
341 	 * Following commands have data areas so we have to get the location
342 	 * of the data buffer offset and data buffer length for the particular
343 	 * command.
344 	 */
345 	switch (shdr->Command) {
346 	case SMB2_NEGOTIATE:
347 		*off = le16_to_cpu(
348 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
349 		*len = le16_to_cpu(
350 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
351 		break;
352 	case SMB2_SESSION_SETUP:
353 		*off = le16_to_cpu(
354 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
355 		*len = le16_to_cpu(
356 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
357 		break;
358 	case SMB2_CREATE:
359 		*off = le32_to_cpu(
360 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
361 		*len = le32_to_cpu(
362 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
363 		break;
364 	case SMB2_QUERY_INFO:
365 		*off = le16_to_cpu(
366 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
367 		*len = le32_to_cpu(
368 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
369 		break;
370 	case SMB2_READ:
371 		/* TODO: is this a bug ? */
372 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
373 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
374 		break;
375 	case SMB2_QUERY_DIRECTORY:
376 		*off = le16_to_cpu(
377 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
378 		*len = le32_to_cpu(
379 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
380 		break;
381 	case SMB2_IOCTL:
382 		*off = le32_to_cpu(
383 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
384 		*len = le32_to_cpu(
385 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
386 		break;
387 	case SMB2_CHANGE_NOTIFY:
388 		*off = le16_to_cpu(
389 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
390 		*len = le32_to_cpu(
391 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
392 		break;
393 	default:
394 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
395 		break;
396 	}
397 
398 	/*
399 	 * Invalid length or offset probably means data area is invalid, but
400 	 * we have little choice but to ignore the data area in this case.
401 	 */
402 	if (unlikely(*off < 0 || *off > max_off ||
403 		     *len < 0 || *len > max_len)) {
404 		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
405 			 __func__, *off, *len);
406 		*off = 0;
407 		*len = 0;
408 	} else if (*off == 0) {
409 		*len = 0;
410 	}
411 
412 	/* return pointer to beginning of data area, ie offset from SMB start */
413 	if (*off > 0 && *len > 0)
414 		return (char *)shdr + *off;
415 	return NULL;
416 }
417 
418 /*
419  * Calculate the size of the SMB message based on the fixed header
420  * portion, the number of word parameters and the data portion of the message.
421  * If have_data is non-NULL, it is set to true when a non-empty data area was
422  * found (data_length > 0), allowing callers to distinguish the implied bcc[0]
423  * case (no data area) from an overreported data length.
424  */
425 static unsigned int
426 __smb2_calc_size(void *buf, bool *have_data)
427 {
428 	struct smb2_pdu *pdu = buf;
429 	struct smb2_hdr *shdr = &pdu->hdr;
430 	int offset; /* the offset from the beginning of SMB to data area */
431 	int data_length = 0; /* the length of the variable length data area */
432 	/* Structure Size has already been checked to make sure it is 64 */
433 	int len = le16_to_cpu(shdr->StructureSize);
434 
435 	/*
436 	 * StructureSize2, ie length of fixed parameter area has already
437 	 * been checked to make sure it is the correct length.
438 	 */
439 	len += le16_to_cpu(pdu->StructureSize2);
440 
441 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
442 		goto calc_size_exit;
443 
444 	smb2_get_data_area_len(&offset, &data_length, shdr);
445 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
446 
447 	if (data_length > 0) {
448 		/*
449 		 * Check to make sure that data area begins after fixed area,
450 		 * Note that last byte of the fixed area is part of data area
451 		 * for some commands, typically those with odd StructureSize,
452 		 * so we must add one to the calculation.
453 		 */
454 		if (offset + 1 < len) {
455 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
456 				 offset + 1, len);
457 			data_length = 0;
458 		} else {
459 			len = offset + data_length;
460 		}
461 	}
462 calc_size_exit:
463 	cifs_dbg(FYI, "SMB2 len %d\n", len);
464 	if (have_data)
465 		*have_data = (data_length > 0);
466 	return len;
467 }
468 
469 unsigned int
470 smb2_calc_size(void *buf)
471 {
472 	return __smb2_calc_size(buf, NULL);
473 }
474 
475 /* Note: caller must free return buffer */
476 __le16 *
477 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
478 {
479 	const char *start_of_path;
480 	int len;
481 
482 	/* Windows doesn't allow paths beginning with \ */
483 	if (from[0] == '\\')
484 		start_of_path = from + 1;
485 
486 	/* SMB311 POSIX extensions paths do not include leading slash */
487 	else if (cifs_sb_master_tlink(cifs_sb) &&
488 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
489 		 (from[0] == '/')) {
490 		start_of_path = from + 1;
491 	} else
492 		start_of_path = from;
493 
494 	return cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
495 				     cifs_sb->local_nls, cifs_remap(cifs_sb));
496 }
497 
498 __le32 smb2_get_lease_state(struct cifsInodeInfo *cinode, unsigned int oplock)
499 {
500 	unsigned int sbflags = cifs_sb_flags(CIFS_SB(cinode));
501 	__le32 lease = 0;
502 
503 	if ((oplock & CIFS_CACHE_WRITE_FLG) || (sbflags & CIFS_MOUNT_RW_CACHE))
504 		lease |= SMB2_LEASE_WRITE_CACHING_LE;
505 	if (oplock & CIFS_CACHE_HANDLE_FLG)
506 		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
507 	if ((oplock & CIFS_CACHE_READ_FLG) || (sbflags & CIFS_MOUNT_RO_CACHE))
508 		lease |= SMB2_LEASE_READ_CACHING_LE;
509 	return lease;
510 }
511 
512 struct smb2_lease_break_work {
513 	struct work_struct lease_break;
514 	struct tcon_link *tlink;
515 	__u8 lease_key[16];
516 	__le32 lease_state;
517 };
518 
519 static void
520 cifs_ses_oplock_break(struct work_struct *work)
521 {
522 	struct smb2_lease_break_work *lw = container_of(work,
523 				struct smb2_lease_break_work, lease_break);
524 	int rc = 0;
525 
526 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
527 			      lw->lease_state);
528 
529 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
530 	cifs_put_tlink(lw->tlink);
531 	kfree(lw);
532 }
533 
534 static void
535 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
536 			      __le32 new_lease_state)
537 {
538 	struct smb2_lease_break_work *lw;
539 
540 	lw = kmalloc_obj(struct smb2_lease_break_work);
541 	if (!lw) {
542 		cifs_put_tlink(tlink);
543 		return;
544 	}
545 
546 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
547 	lw->tlink = tlink;
548 	lw->lease_state = new_lease_state;
549 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
550 	queue_work(cifsiod_wq, &lw->lease_break);
551 }
552 
553 static bool
554 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
555 {
556 	__u8 lease_state;
557 	struct cifsFileInfo *cfile;
558 	struct cifsInodeInfo *cinode;
559 	int ack_req = le32_to_cpu(rsp->Flags &
560 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
561 
562 	lease_state = le32_to_cpu(rsp->NewLeaseState);
563 
564 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
565 		cinode = CIFS_I(d_inode(cfile->dentry));
566 
567 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
568 							SMB2_LEASE_KEY_SIZE))
569 			continue;
570 
571 		cifs_dbg(FYI, "found in the open list\n");
572 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
573 			 lease_state);
574 
575 		if (ack_req)
576 			cfile->oplock_break_cancelled = false;
577 		else
578 			cfile->oplock_break_cancelled = true;
579 
580 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
581 
582 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
583 		cfile->oplock_level = lease_state;
584 
585 		cifs_queue_oplock_break(cfile);
586 		return true;
587 	}
588 
589 	return false;
590 }
591 
592 static struct cifs_pending_open *
593 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
594 				  struct smb2_lease_break *rsp)
595 {
596 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
597 	int ack_req = le32_to_cpu(rsp->Flags &
598 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
599 	struct cifs_pending_open *open;
600 	struct cifs_pending_open *found = NULL;
601 
602 	list_for_each_entry(open, &tcon->pending_opens, olist) {
603 		if (memcmp(open->lease_key, rsp->LeaseKey,
604 			   SMB2_LEASE_KEY_SIZE))
605 			continue;
606 
607 		if (!found && ack_req) {
608 			found = open;
609 		}
610 
611 		cifs_dbg(FYI, "found in the pending open list\n");
612 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
613 			 lease_state);
614 
615 		open->oplock = lease_state;
616 	}
617 
618 	return found;
619 }
620 
621 static bool
622 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
623 {
624 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
625 	struct TCP_Server_Info *pserver;
626 	struct cifs_ses *ses;
627 	struct cifs_tcon *tcon;
628 	struct cifs_pending_open *open;
629 
630 	/* Trace receipt of lease break request from server */
631 	trace_smb3_lease_break_enter(le32_to_cpu(rsp->CurrentLeaseState),
632 		le32_to_cpu(rsp->Flags),
633 		le16_to_cpu(rsp->Epoch),
634 		le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
635 		le64_to_cpu(rsp->hdr.SessionId),
636 		*((u64 *)rsp->LeaseKey),
637 		*((u64 *)&rsp->LeaseKey[8]));
638 
639 	cifs_dbg(FYI, "Checking for lease break\n");
640 
641 	/* If server is a channel, select the primary channel */
642 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
643 
644 	/* look up tcon based on tid & uid */
645 	spin_lock(&cifs_tcp_ses_lock);
646 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
647 		if (cifs_ses_exiting(ses))
648 			continue;
649 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
650 			spin_lock(&tcon->open_file_lock);
651 			cifs_stats_inc(
652 				       &tcon->stats.cifs_stats.num_oplock_brks);
653 			if (smb2_tcon_has_lease(tcon, rsp)) {
654 				spin_unlock(&tcon->open_file_lock);
655 				spin_unlock(&cifs_tcp_ses_lock);
656 				return true;
657 			}
658 			open = smb2_tcon_find_pending_open_lease(tcon,
659 								 rsp);
660 			if (open) {
661 				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
662 				struct tcon_link *tlink;
663 
664 				tlink = cifs_get_tlink(open->tlink);
665 				memcpy(lease_key, open->lease_key,
666 				       SMB2_LEASE_KEY_SIZE);
667 				spin_unlock(&tcon->open_file_lock);
668 				spin_unlock(&cifs_tcp_ses_lock);
669 				smb2_queue_pending_open_break(tlink,
670 							      lease_key,
671 							      rsp->NewLeaseState);
672 				return true;
673 			}
674 			spin_unlock(&tcon->open_file_lock);
675 
676 			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
677 				spin_unlock(&cifs_tcp_ses_lock);
678 				return true;
679 			}
680 		}
681 	}
682 	spin_unlock(&cifs_tcp_ses_lock);
683 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
684 	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
685 					   le32_to_cpu(rsp->Flags),
686 					   le16_to_cpu(rsp->Epoch),
687 					   le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
688 					   le64_to_cpu(rsp->hdr.SessionId),
689 					   *((u64 *)rsp->LeaseKey),
690 					   *((u64 *)&rsp->LeaseKey[8]));
691 
692 	return false;
693 }
694 
695 bool
696 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
697 {
698 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
699 	struct TCP_Server_Info *pserver;
700 	struct cifs_ses *ses;
701 	struct cifs_tcon *tcon;
702 	struct cifsInodeInfo *cinode;
703 	struct cifsFileInfo *cfile;
704 
705 	cifs_dbg(FYI, "Checking for oplock break\n");
706 
707 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
708 		return false;
709 
710 	if (rsp->StructureSize !=
711 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
712 		if (le16_to_cpu(rsp->StructureSize) == 44)
713 			return smb2_is_valid_lease_break(buffer, server);
714 		else
715 			return false;
716 	}
717 
718 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
719 
720 	/* If server is a channel, select the primary channel */
721 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
722 
723 	/* look up tcon based on tid & uid */
724 	spin_lock(&cifs_tcp_ses_lock);
725 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
726 		if (cifs_ses_exiting(ses))
727 			continue;
728 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
729 
730 			spin_lock(&tcon->open_file_lock);
731 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
732 				if (rsp->PersistentFid !=
733 				    cfile->fid.persistent_fid ||
734 				    rsp->VolatileFid !=
735 				    cfile->fid.volatile_fid)
736 					continue;
737 
738 				cifs_dbg(FYI, "file id match, oplock break\n");
739 				cifs_stats_inc(
740 				    &tcon->stats.cifs_stats.num_oplock_brks);
741 				cinode = CIFS_I(d_inode(cfile->dentry));
742 				spin_lock(&cfile->file_info_lock);
743 				if (!CIFS_CACHE_WRITE(cinode) &&
744 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
745 					cfile->oplock_break_cancelled = true;
746 				else
747 					cfile->oplock_break_cancelled = false;
748 
749 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
750 					&cinode->flags);
751 
752 				cfile->oplock_epoch = 0;
753 				cfile->oplock_level = rsp->OplockLevel;
754 
755 				spin_unlock(&cfile->file_info_lock);
756 
757 				cifs_queue_oplock_break(cfile);
758 
759 				spin_unlock(&tcon->open_file_lock);
760 				spin_unlock(&cifs_tcp_ses_lock);
761 				return true;
762 			}
763 			spin_unlock(&tcon->open_file_lock);
764 		}
765 	}
766 	spin_unlock(&cifs_tcp_ses_lock);
767 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
768 	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
769 				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
770 				  le64_to_cpu(rsp->hdr.SessionId));
771 
772 	return true;
773 }
774 
775 void
776 smb2_cancelled_close_fid(struct work_struct *work)
777 {
778 	struct close_cancelled_open *cancelled = container_of(work,
779 					struct close_cancelled_open, work);
780 	struct cifs_tcon *tcon = cancelled->tcon;
781 	int rc;
782 
783 	if (cancelled->mid)
784 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
785 			      cancelled->mid);
786 	else
787 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
788 
789 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
790 			cancelled->fid.volatile_fid);
791 	if (rc)
792 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
793 
794 	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
795 	kfree(cancelled);
796 }
797 
798 /*
799  * Caller should already has an extra reference to @tcon
800  * This function is used to queue work to close a handle to prevent leaks
801  * on the server.
802  * We handle two cases. If an open was interrupted after we sent the
803  * SMB2_CREATE to the server but before we processed the reply, and second
804  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
805  */
806 static int
807 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
808 			    __u64 persistent_fid, __u64 volatile_fid)
809 {
810 	struct close_cancelled_open *cancelled;
811 
812 	cancelled = kzalloc_obj(*cancelled);
813 	if (!cancelled)
814 		return -ENOMEM;
815 
816 	cancelled->fid.persistent_fid = persistent_fid;
817 	cancelled->fid.volatile_fid = volatile_fid;
818 	cancelled->tcon = tcon;
819 	cancelled->cmd = cmd;
820 	cancelled->mid = mid;
821 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
822 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
823 
824 	return 0;
825 }
826 
827 int
828 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
829 			    __u64 volatile_fid)
830 {
831 	int rc;
832 
833 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
834 	spin_lock(&tcon->tc_lock);
835 	if (tcon->tc_count <= 0) {
836 		struct TCP_Server_Info *server = NULL;
837 
838 		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
839 				    netfs_trace_tcon_ref_see_cancelled_close);
840 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
841 		spin_unlock(&tcon->tc_lock);
842 
843 		if (tcon->ses) {
844 			server = tcon->ses->server;
845 			cifs_server_dbg(FYI,
846 					"tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
847 					tcon->tid, persistent_fid, volatile_fid);
848 		}
849 
850 		return 0;
851 	}
852 	tcon->tc_count++;
853 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
854 			    netfs_trace_tcon_ref_get_cancelled_close);
855 	spin_unlock(&tcon->tc_lock);
856 
857 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
858 					 persistent_fid, volatile_fid);
859 	if (rc)
860 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
861 
862 	return rc;
863 }
864 
865 int
866 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
867 {
868 	struct smb2_hdr *hdr = mid->resp_buf;
869 	struct smb2_create_rsp *rsp = mid->resp_buf;
870 	struct cifs_tcon *tcon;
871 	int rc;
872 
873 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
874 	    hdr->Status != STATUS_SUCCESS)
875 		return 0;
876 
877 	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
878 				  le32_to_cpu(hdr->Id.SyncId.TreeId));
879 	if (!tcon)
880 		return -ENOENT;
881 
882 	rc = __smb2_handle_cancelled_cmd(tcon,
883 					 le16_to_cpu(hdr->Command),
884 					 le64_to_cpu(hdr->MessageId),
885 					 rsp->PersistentFileId,
886 					 rsp->VolatileFileId);
887 	if (rc)
888 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
889 
890 	return rc;
891 }
892 
893 /**
894  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
895  *
896  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
897  * SMB2 header.
898  *
899  * @ses:	server session structure
900  * @server:	pointer to server info
901  * @iov:	array containing the SMB request we will send to the server
902  * @nvec:	number of array entries for the iov
903  */
904 void
905 smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
906 			   struct kvec *iov, int nvec)
907 {
908 	int i;
909 	struct smb2_hdr *hdr;
910 	struct sha512_ctx sha_ctx;
911 
912 	hdr = (struct smb2_hdr *)iov[0].iov_base;
913 	/* neg prot are always taken */
914 	if (hdr->Command == SMB2_NEGOTIATE)
915 		goto ok;
916 
917 	/*
918 	 * If we process a command which wasn't a negprot it means the
919 	 * neg prot was already done, so the server dialect was set
920 	 * and we can test it. Preauth requires 3.1.1 for now.
921 	 */
922 	if (server->dialect != SMB311_PROT_ID)
923 		return;
924 
925 	if (hdr->Command != SMB2_SESSION_SETUP)
926 		return;
927 
928 	/* skip last sess setup response */
929 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
930 	    && (hdr->Status == NT_STATUS_OK
931 		|| (hdr->Status !=
932 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
933 		return;
934 
935 ok:
936 	sha512_init(&sha_ctx);
937 	sha512_update(&sha_ctx, ses->preauth_sha_hash, SMB2_PREAUTH_HASH_SIZE);
938 	for (i = 0; i < nvec; i++)
939 		sha512_update(&sha_ctx, iov[i].iov_base, iov[i].iov_len);
940 	sha512_final(&sha_ctx, ses->preauth_sha_hash);
941 }
942