xref: /linux/fs/smb/client/smb2misc.c (revision 4ccb3a800028759b2ba39857cb180589575d7445)
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
check_smb2_hdr(struct smb2_hdr * shdr,__u64 mid)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 
get_neg_ctxt_len(struct smb2_hdr * hdr,__u32 len,__u32 non_ctxlen)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
smb2_check_message(char * buf,unsigned int len,struct TCP_Server_Info * server)137 smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
138 {
139 	struct TCP_Server_Info *pserver;
140 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
141 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
142 	int hdr_size = sizeof(struct smb2_hdr);
143 	int pdu_size = sizeof(struct smb2_pdu);
144 	int command;
145 	__u32 calc_len; /* calculated length */
146 	__u64 mid;
147 
148 	/* If server is a channel, select the primary channel */
149 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
150 
151 	/*
152 	 * Add function to do table lookup of StructureSize by command
153 	 * ie Validate the wct via smb2_struct_sizes table above
154 	 */
155 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
156 		struct smb2_transform_hdr *thdr =
157 			(struct smb2_transform_hdr *)buf;
158 		struct cifs_ses *ses = NULL;
159 		struct cifs_ses *iter;
160 
161 		/* decrypt frame now that it is completely read in */
162 		spin_lock(&cifs_tcp_ses_lock);
163 		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
164 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
165 				ses = iter;
166 				break;
167 			}
168 		}
169 		spin_unlock(&cifs_tcp_ses_lock);
170 		if (!ses) {
171 			cifs_dbg(VFS, "no decryption - session id not found\n");
172 			return 1;
173 		}
174 	}
175 
176 	mid = le64_to_cpu(shdr->MessageId);
177 	if (check_smb2_hdr(shdr, mid))
178 		return 1;
179 
180 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
181 		cifs_dbg(VFS, "Invalid structure size %u\n",
182 			 le16_to_cpu(shdr->StructureSize));
183 		return 1;
184 	}
185 
186 	command = le16_to_cpu(shdr->Command);
187 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
188 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
189 		return 1;
190 	}
191 
192 	if (len < pdu_size) {
193 		if ((len >= hdr_size)
194 		    && (shdr->Status != 0)) {
195 			pdu->StructureSize2 = 0;
196 			/*
197 			 * As with SMB/CIFS, on some error cases servers may
198 			 * not return wct properly
199 			 */
200 			return 0;
201 		} else {
202 			cifs_dbg(VFS, "Length less than SMB header size\n");
203 		}
204 		return 1;
205 	}
206 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
207 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
208 			 mid);
209 		return 1;
210 	}
211 
212 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
213 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
214 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
215 			/* error packets have 9 byte structure size */
216 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
217 				 le16_to_cpu(pdu->StructureSize2), command);
218 			return 1;
219 		} else if (command == SMB2_OPLOCK_BREAK_HE
220 			   && (shdr->Status == 0)
221 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
222 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
223 			/* special case for SMB2.1 lease break message */
224 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
225 				 le16_to_cpu(pdu->StructureSize2));
226 			return 1;
227 		}
228 	}
229 
230 	calc_len = smb2_calc_size(buf);
231 
232 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
233 	 * be 0, and not a real miscalculation */
234 	if (command == SMB2_IOCTL_HE && calc_len == 0)
235 		return 0;
236 
237 	if (command == SMB2_NEGOTIATE_HE)
238 		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
239 
240 	if (len != calc_len) {
241 		/* create failed on symlink */
242 		if (command == SMB2_CREATE_HE &&
243 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK)
244 			return 0;
245 		/* Windows 7 server returns 24 bytes more */
246 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
247 			return 0;
248 		/* server can return one byte more due to implied bcc[0] */
249 		if (calc_len == len + 1)
250 			return 0;
251 
252 		/*
253 		 * Some windows servers (win2016) will pad also the final
254 		 * PDU in a compound to 8 bytes.
255 		 */
256 		if (ALIGN(calc_len, 8) == len)
257 			return 0;
258 
259 		/*
260 		 * MacOS server pads after SMB2.1 write response with 3 bytes
261 		 * of junk. Other servers match RFC1001 len to actual
262 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
263 		 * Some windows servers also pad up to 8 bytes when compounding.
264 		 */
265 		if (calc_len < len)
266 			return 0;
267 
268 		/* Only log a message if len was really miscalculated */
269 		if (unlikely(cifsFYI))
270 			cifs_dbg(FYI, "Server response too short: calculated "
271 				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
272 				 calc_len, len, command, mid);
273 		else
274 			pr_warn("Server response too short: calculated length "
275 				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
276 				calc_len, len, command, mid);
277 
278 		return 1;
279 	}
280 	return 0;
281 }
282 
283 /*
284  * The size of the variable area depends on the offset and length fields
285  * located in different fields for various SMB2 responses. SMB2 responses
286  * with no variable length info, show an offset of zero for the offset field.
287  */
288 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
289 	/* SMB2_NEGOTIATE */ true,
290 	/* SMB2_SESSION_SETUP */ true,
291 	/* SMB2_LOGOFF */ false,
292 	/* SMB2_TREE_CONNECT */	false,
293 	/* SMB2_TREE_DISCONNECT */ false,
294 	/* SMB2_CREATE */ true,
295 	/* SMB2_CLOSE */ false,
296 	/* SMB2_FLUSH */ false,
297 	/* SMB2_READ */	true,
298 	/* SMB2_WRITE */ false,
299 	/* SMB2_LOCK */	false,
300 	/* SMB2_IOCTL */ true,
301 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
302 	/* SMB2_ECHO */ false,
303 	/* SMB2_QUERY_DIRECTORY */ true,
304 	/* SMB2_CHANGE_NOTIFY */ true,
305 	/* SMB2_QUERY_INFO */ true,
306 	/* SMB2_SET_INFO */ false,
307 	/* SMB2_OPLOCK_BREAK */ false
308 };
309 
310 /*
311  * Returns the pointer to the beginning of the data area. Length of the data
312  * area and the offset to it (from the beginning of the smb are also returned.
313  */
314 char *
smb2_get_data_area_len(int * off,int * len,struct smb2_hdr * shdr)315 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
316 {
317 	const int max_off = 4096;
318 	const int max_len = 128 * 1024;
319 
320 	*off = 0;
321 	*len = 0;
322 
323 	/* error responses do not have data area */
324 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
325 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
326 						SMB2_ERROR_STRUCTURE_SIZE2_LE)
327 		return NULL;
328 
329 	/*
330 	 * Following commands have data areas so we have to get the location
331 	 * of the data buffer offset and data buffer length for the particular
332 	 * command.
333 	 */
334 	switch (shdr->Command) {
335 	case SMB2_NEGOTIATE:
336 		*off = le16_to_cpu(
337 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
338 		*len = le16_to_cpu(
339 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
340 		break;
341 	case SMB2_SESSION_SETUP:
342 		*off = le16_to_cpu(
343 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
344 		*len = le16_to_cpu(
345 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
346 		break;
347 	case SMB2_CREATE:
348 		*off = le32_to_cpu(
349 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
350 		*len = le32_to_cpu(
351 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
352 		break;
353 	case SMB2_QUERY_INFO:
354 		*off = le16_to_cpu(
355 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
356 		*len = le32_to_cpu(
357 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
358 		break;
359 	case SMB2_READ:
360 		/* TODO: is this a bug ? */
361 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
362 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
363 		break;
364 	case SMB2_QUERY_DIRECTORY:
365 		*off = le16_to_cpu(
366 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
367 		*len = le32_to_cpu(
368 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
369 		break;
370 	case SMB2_IOCTL:
371 		*off = le32_to_cpu(
372 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
373 		*len = le32_to_cpu(
374 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
375 		break;
376 	case SMB2_CHANGE_NOTIFY:
377 		*off = le16_to_cpu(
378 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
379 		*len = le32_to_cpu(
380 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
381 		break;
382 	default:
383 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
384 		break;
385 	}
386 
387 	/*
388 	 * Invalid length or offset probably means data area is invalid, but
389 	 * we have little choice but to ignore the data area in this case.
390 	 */
391 	if (unlikely(*off < 0 || *off > max_off ||
392 		     *len < 0 || *len > max_len)) {
393 		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
394 			 __func__, *off, *len);
395 		*off = 0;
396 		*len = 0;
397 	} else if (*off == 0) {
398 		*len = 0;
399 	}
400 
401 	/* return pointer to beginning of data area, ie offset from SMB start */
402 	if (*off > 0 && *len > 0)
403 		return (char *)shdr + *off;
404 	return NULL;
405 }
406 
407 /*
408  * Calculate the size of the SMB message based on the fixed header
409  * portion, the number of word parameters and the data portion of the message.
410  */
411 unsigned int
smb2_calc_size(void * buf)412 smb2_calc_size(void *buf)
413 {
414 	struct smb2_pdu *pdu = buf;
415 	struct smb2_hdr *shdr = &pdu->hdr;
416 	int offset; /* the offset from the beginning of SMB to data area */
417 	int data_length; /* the length of the variable length data area */
418 	/* Structure Size has already been checked to make sure it is 64 */
419 	int len = le16_to_cpu(shdr->StructureSize);
420 
421 	/*
422 	 * StructureSize2, ie length of fixed parameter area has already
423 	 * been checked to make sure it is the correct length.
424 	 */
425 	len += le16_to_cpu(pdu->StructureSize2);
426 
427 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
428 		goto calc_size_exit;
429 
430 	smb2_get_data_area_len(&offset, &data_length, shdr);
431 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
432 
433 	if (data_length > 0) {
434 		/*
435 		 * Check to make sure that data area begins after fixed area,
436 		 * Note that last byte of the fixed area is part of data area
437 		 * for some commands, typically those with odd StructureSize,
438 		 * so we must add one to the calculation.
439 		 */
440 		if (offset + 1 < len) {
441 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
442 				 offset + 1, len);
443 			data_length = 0;
444 		} else {
445 			len = offset + data_length;
446 		}
447 	}
448 calc_size_exit:
449 	cifs_dbg(FYI, "SMB2 len %d\n", len);
450 	return len;
451 }
452 
453 /* Note: caller must free return buffer */
454 __le16 *
cifs_convert_path_to_utf16(const char * from,struct cifs_sb_info * cifs_sb)455 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
456 {
457 	int len;
458 	const char *start_of_path;
459 	__le16 *to;
460 	int map_type;
461 
462 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
463 		map_type = SFM_MAP_UNI_RSVD;
464 	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
465 		map_type = SFU_MAP_UNI_RSVD;
466 	else
467 		map_type = NO_MAP_UNI_RSVD;
468 
469 	/* Windows doesn't allow paths beginning with \ */
470 	if (from[0] == '\\')
471 		start_of_path = from + 1;
472 
473 	/* SMB311 POSIX extensions paths do not include leading slash */
474 	else if (cifs_sb_master_tlink(cifs_sb) &&
475 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
476 		 (from[0] == '/')) {
477 		start_of_path = from + 1;
478 	} else
479 		start_of_path = from;
480 
481 	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
482 				   cifs_sb->local_nls, map_type);
483 	return to;
484 }
485 
486 __le32
smb2_get_lease_state(struct cifsInodeInfo * cinode)487 smb2_get_lease_state(struct cifsInodeInfo *cinode)
488 {
489 	__le32 lease = 0;
490 
491 	if (CIFS_CACHE_WRITE(cinode))
492 		lease |= SMB2_LEASE_WRITE_CACHING_LE;
493 	if (CIFS_CACHE_HANDLE(cinode))
494 		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
495 	if (CIFS_CACHE_READ(cinode))
496 		lease |= SMB2_LEASE_READ_CACHING_LE;
497 	return lease;
498 }
499 
500 struct smb2_lease_break_work {
501 	struct work_struct lease_break;
502 	struct tcon_link *tlink;
503 	__u8 lease_key[16];
504 	__le32 lease_state;
505 };
506 
507 static void
cifs_ses_oplock_break(struct work_struct * work)508 cifs_ses_oplock_break(struct work_struct *work)
509 {
510 	struct smb2_lease_break_work *lw = container_of(work,
511 				struct smb2_lease_break_work, lease_break);
512 	int rc = 0;
513 
514 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
515 			      lw->lease_state);
516 
517 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
518 	cifs_put_tlink(lw->tlink);
519 	kfree(lw);
520 }
521 
522 static void
smb2_queue_pending_open_break(struct tcon_link * tlink,__u8 * lease_key,__le32 new_lease_state)523 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
524 			      __le32 new_lease_state)
525 {
526 	struct smb2_lease_break_work *lw;
527 
528 	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
529 	if (!lw) {
530 		cifs_put_tlink(tlink);
531 		return;
532 	}
533 
534 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
535 	lw->tlink = tlink;
536 	lw->lease_state = new_lease_state;
537 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
538 	queue_work(cifsiod_wq, &lw->lease_break);
539 }
540 
541 static bool
smb2_tcon_has_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)542 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
543 {
544 	__u8 lease_state;
545 	struct cifsFileInfo *cfile;
546 	struct cifsInodeInfo *cinode;
547 	int ack_req = le32_to_cpu(rsp->Flags &
548 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
549 
550 	lease_state = le32_to_cpu(rsp->NewLeaseState);
551 
552 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
553 		cinode = CIFS_I(d_inode(cfile->dentry));
554 
555 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
556 							SMB2_LEASE_KEY_SIZE))
557 			continue;
558 
559 		cifs_dbg(FYI, "found in the open list\n");
560 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
561 			 lease_state);
562 
563 		if (ack_req)
564 			cfile->oplock_break_cancelled = false;
565 		else
566 			cfile->oplock_break_cancelled = true;
567 
568 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
569 
570 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
571 		cfile->oplock_level = lease_state;
572 
573 		cifs_queue_oplock_break(cfile);
574 		return true;
575 	}
576 
577 	return false;
578 }
579 
580 static struct cifs_pending_open *
smb2_tcon_find_pending_open_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)581 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
582 				  struct smb2_lease_break *rsp)
583 {
584 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
585 	int ack_req = le32_to_cpu(rsp->Flags &
586 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
587 	struct cifs_pending_open *open;
588 	struct cifs_pending_open *found = NULL;
589 
590 	list_for_each_entry(open, &tcon->pending_opens, olist) {
591 		if (memcmp(open->lease_key, rsp->LeaseKey,
592 			   SMB2_LEASE_KEY_SIZE))
593 			continue;
594 
595 		if (!found && ack_req) {
596 			found = open;
597 		}
598 
599 		cifs_dbg(FYI, "found in the pending open list\n");
600 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
601 			 lease_state);
602 
603 		open->oplock = lease_state;
604 	}
605 
606 	return found;
607 }
608 
609 static bool
smb2_is_valid_lease_break(char * buffer,struct TCP_Server_Info * server)610 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
611 {
612 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
613 	struct TCP_Server_Info *pserver;
614 	struct cifs_ses *ses;
615 	struct cifs_tcon *tcon;
616 	struct cifs_pending_open *open;
617 
618 	/* Trace receipt of lease break request from server */
619 	trace_smb3_lease_break_enter(le32_to_cpu(rsp->CurrentLeaseState),
620 		le32_to_cpu(rsp->Flags),
621 		le16_to_cpu(rsp->Epoch),
622 		le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
623 		le64_to_cpu(rsp->hdr.SessionId),
624 		*((u64 *)rsp->LeaseKey),
625 		*((u64 *)&rsp->LeaseKey[8]));
626 
627 	cifs_dbg(FYI, "Checking for lease break\n");
628 
629 	/* If server is a channel, select the primary channel */
630 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
631 
632 	/* look up tcon based on tid & uid */
633 	spin_lock(&cifs_tcp_ses_lock);
634 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
635 		if (cifs_ses_exiting(ses))
636 			continue;
637 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
638 			spin_lock(&tcon->open_file_lock);
639 			cifs_stats_inc(
640 				       &tcon->stats.cifs_stats.num_oplock_brks);
641 			if (smb2_tcon_has_lease(tcon, rsp)) {
642 				spin_unlock(&tcon->open_file_lock);
643 				spin_unlock(&cifs_tcp_ses_lock);
644 				return true;
645 			}
646 			open = smb2_tcon_find_pending_open_lease(tcon,
647 								 rsp);
648 			if (open) {
649 				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
650 				struct tcon_link *tlink;
651 
652 				tlink = cifs_get_tlink(open->tlink);
653 				memcpy(lease_key, open->lease_key,
654 				       SMB2_LEASE_KEY_SIZE);
655 				spin_unlock(&tcon->open_file_lock);
656 				spin_unlock(&cifs_tcp_ses_lock);
657 				smb2_queue_pending_open_break(tlink,
658 							      lease_key,
659 							      rsp->NewLeaseState);
660 				return true;
661 			}
662 			spin_unlock(&tcon->open_file_lock);
663 
664 			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
665 				spin_unlock(&cifs_tcp_ses_lock);
666 				return true;
667 			}
668 		}
669 	}
670 	spin_unlock(&cifs_tcp_ses_lock);
671 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
672 	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
673 					   le32_to_cpu(rsp->Flags),
674 					   le16_to_cpu(rsp->Epoch),
675 					   le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
676 					   le64_to_cpu(rsp->hdr.SessionId),
677 					   *((u64 *)rsp->LeaseKey),
678 					   *((u64 *)&rsp->LeaseKey[8]));
679 
680 	return false;
681 }
682 
683 bool
smb2_is_valid_oplock_break(char * buffer,struct TCP_Server_Info * server)684 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
685 {
686 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
687 	struct TCP_Server_Info *pserver;
688 	struct cifs_ses *ses;
689 	struct cifs_tcon *tcon;
690 	struct cifsInodeInfo *cinode;
691 	struct cifsFileInfo *cfile;
692 
693 	cifs_dbg(FYI, "Checking for oplock break\n");
694 
695 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
696 		return false;
697 
698 	if (rsp->StructureSize !=
699 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
700 		if (le16_to_cpu(rsp->StructureSize) == 44)
701 			return smb2_is_valid_lease_break(buffer, server);
702 		else
703 			return false;
704 	}
705 
706 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
707 
708 	/* If server is a channel, select the primary channel */
709 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
710 
711 	/* look up tcon based on tid & uid */
712 	spin_lock(&cifs_tcp_ses_lock);
713 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
714 		if (cifs_ses_exiting(ses))
715 			continue;
716 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
717 
718 			spin_lock(&tcon->open_file_lock);
719 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
720 				if (rsp->PersistentFid !=
721 				    cfile->fid.persistent_fid ||
722 				    rsp->VolatileFid !=
723 				    cfile->fid.volatile_fid)
724 					continue;
725 
726 				cifs_dbg(FYI, "file id match, oplock break\n");
727 				cifs_stats_inc(
728 				    &tcon->stats.cifs_stats.num_oplock_brks);
729 				cinode = CIFS_I(d_inode(cfile->dentry));
730 				spin_lock(&cfile->file_info_lock);
731 				if (!CIFS_CACHE_WRITE(cinode) &&
732 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
733 					cfile->oplock_break_cancelled = true;
734 				else
735 					cfile->oplock_break_cancelled = false;
736 
737 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
738 					&cinode->flags);
739 
740 				cfile->oplock_epoch = 0;
741 				cfile->oplock_level = rsp->OplockLevel;
742 
743 				spin_unlock(&cfile->file_info_lock);
744 
745 				cifs_queue_oplock_break(cfile);
746 
747 				spin_unlock(&tcon->open_file_lock);
748 				spin_unlock(&cifs_tcp_ses_lock);
749 				return true;
750 			}
751 			spin_unlock(&tcon->open_file_lock);
752 		}
753 	}
754 	spin_unlock(&cifs_tcp_ses_lock);
755 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
756 	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
757 				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
758 				  le64_to_cpu(rsp->hdr.SessionId));
759 
760 	return true;
761 }
762 
763 void
smb2_cancelled_close_fid(struct work_struct * work)764 smb2_cancelled_close_fid(struct work_struct *work)
765 {
766 	struct close_cancelled_open *cancelled = container_of(work,
767 					struct close_cancelled_open, work);
768 	struct cifs_tcon *tcon = cancelled->tcon;
769 	int rc;
770 
771 	if (cancelled->mid)
772 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
773 			      cancelled->mid);
774 	else
775 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
776 
777 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
778 			cancelled->fid.volatile_fid);
779 	if (rc)
780 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
781 
782 	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
783 	kfree(cancelled);
784 }
785 
786 /*
787  * Caller should already has an extra reference to @tcon
788  * This function is used to queue work to close a handle to prevent leaks
789  * on the server.
790  * We handle two cases. If an open was interrupted after we sent the
791  * SMB2_CREATE to the server but before we processed the reply, and second
792  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
793  */
794 static int
__smb2_handle_cancelled_cmd(struct cifs_tcon * tcon,__u16 cmd,__u64 mid,__u64 persistent_fid,__u64 volatile_fid)795 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
796 			    __u64 persistent_fid, __u64 volatile_fid)
797 {
798 	struct close_cancelled_open *cancelled;
799 
800 	cancelled = kzalloc(sizeof(*cancelled), GFP_KERNEL);
801 	if (!cancelled)
802 		return -ENOMEM;
803 
804 	cancelled->fid.persistent_fid = persistent_fid;
805 	cancelled->fid.volatile_fid = volatile_fid;
806 	cancelled->tcon = tcon;
807 	cancelled->cmd = cmd;
808 	cancelled->mid = mid;
809 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
810 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
811 
812 	return 0;
813 }
814 
815 int
smb2_handle_cancelled_close(struct cifs_tcon * tcon,__u64 persistent_fid,__u64 volatile_fid)816 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
817 			    __u64 volatile_fid)
818 {
819 	int rc;
820 
821 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
822 	spin_lock(&cifs_tcp_ses_lock);
823 	if (tcon->tc_count <= 0) {
824 		struct TCP_Server_Info *server = NULL;
825 
826 		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
827 				    netfs_trace_tcon_ref_see_cancelled_close);
828 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
829 		spin_unlock(&cifs_tcp_ses_lock);
830 
831 		if (tcon->ses) {
832 			server = tcon->ses->server;
833 			cifs_server_dbg(FYI,
834 					"tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
835 					tcon->tid, persistent_fid, volatile_fid);
836 		}
837 
838 		return 0;
839 	}
840 	tcon->tc_count++;
841 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
842 			    netfs_trace_tcon_ref_get_cancelled_close);
843 	spin_unlock(&cifs_tcp_ses_lock);
844 
845 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
846 					 persistent_fid, volatile_fid);
847 	if (rc)
848 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
849 
850 	return rc;
851 }
852 
853 int
smb2_handle_cancelled_mid(struct mid_q_entry * mid,struct TCP_Server_Info * server)854 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
855 {
856 	struct smb2_hdr *hdr = mid->resp_buf;
857 	struct smb2_create_rsp *rsp = mid->resp_buf;
858 	struct cifs_tcon *tcon;
859 	int rc;
860 
861 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
862 	    hdr->Status != STATUS_SUCCESS)
863 		return 0;
864 
865 	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
866 				  le32_to_cpu(hdr->Id.SyncId.TreeId));
867 	if (!tcon)
868 		return -ENOENT;
869 
870 	rc = __smb2_handle_cancelled_cmd(tcon,
871 					 le16_to_cpu(hdr->Command),
872 					 le64_to_cpu(hdr->MessageId),
873 					 rsp->PersistentFileId,
874 					 rsp->VolatileFileId);
875 	if (rc)
876 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
877 
878 	return rc;
879 }
880 
881 /**
882  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
883  *
884  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
885  * SMB2 header.
886  *
887  * @ses:	server session structure
888  * @server:	pointer to server info
889  * @iov:	array containing the SMB request we will send to the server
890  * @nvec:	number of array entries for the iov
891  */
892 void
smb311_update_preauth_hash(struct cifs_ses * ses,struct TCP_Server_Info * server,struct kvec * iov,int nvec)893 smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
894 			   struct kvec *iov, int nvec)
895 {
896 	int i;
897 	struct smb2_hdr *hdr;
898 	struct sha512_ctx sha_ctx;
899 
900 	hdr = (struct smb2_hdr *)iov[0].iov_base;
901 	/* neg prot are always taken */
902 	if (hdr->Command == SMB2_NEGOTIATE)
903 		goto ok;
904 
905 	/*
906 	 * If we process a command which wasn't a negprot it means the
907 	 * neg prot was already done, so the server dialect was set
908 	 * and we can test it. Preauth requires 3.1.1 for now.
909 	 */
910 	if (server->dialect != SMB311_PROT_ID)
911 		return;
912 
913 	if (hdr->Command != SMB2_SESSION_SETUP)
914 		return;
915 
916 	/* skip last sess setup response */
917 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
918 	    && (hdr->Status == NT_STATUS_OK
919 		|| (hdr->Status !=
920 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
921 		return;
922 
923 ok:
924 	sha512_init(&sha_ctx);
925 	sha512_update(&sha_ctx, ses->preauth_sha_hash, SMB2_PREAUTH_HASH_SIZE);
926 	for (i = 0; i < nvec; i++)
927 		sha512_update(&sha_ctx, iov[i].iov_base, iov[i].iov_len);
928 	sha512_final(&sha_ctx, ses->preauth_sha_hash);
929 }
930