xref: /openbmc/linux/fs/smb/client/smb2misc.c (revision 07e76ea1)
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 <linux/ctype.h>
11 #include "cifsglob.h"
12 #include "cifsproto.h"
13 #include "smb2proto.h"
14 #include "cifs_debug.h"
15 #include "cifs_unicode.h"
16 #include "smb2status.h"
17 #include "smb2glob.h"
18 #include "nterr.h"
19 #include "cached_dir.h"
20 
21 static int
check_smb2_hdr(struct smb2_hdr * shdr,__u64 mid)22 check_smb2_hdr(struct smb2_hdr *shdr, __u64 mid)
23 {
24 	__u64 wire_mid = le64_to_cpu(shdr->MessageId);
25 
26 	/*
27 	 * Make sure that this really is an SMB, that it is a response,
28 	 * and that the message ids match.
29 	 */
30 	if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
31 	    (mid == wire_mid)) {
32 		if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
33 			return 0;
34 		else {
35 			/* only one valid case where server sends us request */
36 			if (shdr->Command == SMB2_OPLOCK_BREAK)
37 				return 0;
38 			else
39 				cifs_dbg(VFS, "Received Request not response\n");
40 		}
41 	} else { /* bad signature or mid */
42 		if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
43 			cifs_dbg(VFS, "Bad protocol string signature header %x\n",
44 				 le32_to_cpu(shdr->ProtocolId));
45 		if (mid != wire_mid)
46 			cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
47 				 mid, wire_mid);
48 	}
49 	cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
50 	return 1;
51 }
52 
53 /*
54  *  The following table defines the expected "StructureSize" of SMB2 responses
55  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
56  *
57  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
58  *  indexed by command in host byte order
59  */
60 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
61 	/* SMB2_NEGOTIATE */ cpu_to_le16(65),
62 	/* SMB2_SESSION_SETUP */ cpu_to_le16(9),
63 	/* SMB2_LOGOFF */ cpu_to_le16(4),
64 	/* SMB2_TREE_CONNECT */ cpu_to_le16(16),
65 	/* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
66 	/* SMB2_CREATE */ cpu_to_le16(89),
67 	/* SMB2_CLOSE */ cpu_to_le16(60),
68 	/* SMB2_FLUSH */ cpu_to_le16(4),
69 	/* SMB2_READ */ cpu_to_le16(17),
70 	/* SMB2_WRITE */ cpu_to_le16(17),
71 	/* SMB2_LOCK */ cpu_to_le16(4),
72 	/* SMB2_IOCTL */ cpu_to_le16(49),
73 	/* BB CHECK this ... not listed in documentation */
74 	/* SMB2_CANCEL */ cpu_to_le16(0),
75 	/* SMB2_ECHO */ cpu_to_le16(4),
76 	/* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
77 	/* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
78 	/* SMB2_QUERY_INFO */ cpu_to_le16(9),
79 	/* SMB2_SET_INFO */ cpu_to_le16(2),
80 	/* BB FIXME can also be 44 for lease break */
81 	/* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
82 };
83 
84 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_hdr) + sizeof(struct smb2_negotiate_rsp))
85 
get_neg_ctxt_len(struct smb2_hdr * hdr,__u32 len,__u32 non_ctxlen)86 static __u32 get_neg_ctxt_len(struct smb2_hdr *hdr, __u32 len,
87 			      __u32 non_ctxlen)
88 {
89 	__u16 neg_count;
90 	__u32 nc_offset, size_of_pad_before_neg_ctxts;
91 	struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
92 
93 	/* Negotiate contexts are only valid for latest dialect SMB3.11 */
94 	neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
95 	if ((neg_count == 0) ||
96 	   (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
97 		return 0;
98 
99 	/*
100 	 * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
101 	 * which security mechanisms the server supports) make sure that
102 	 * the negotiate contexts start after it
103 	 */
104 	nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
105 	/*
106 	 * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
107 	 * and the latter is 1 byte bigger than the fix-sized area of the
108 	 * NEGOTIATE response
109 	 */
110 	if (nc_offset + 1 < non_ctxlen) {
111 		pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
112 		return 0;
113 	} else if (nc_offset + 1 == non_ctxlen) {
114 		cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
115 		size_of_pad_before_neg_ctxts = 0;
116 	} else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE + 1)
117 		/* has padding, but no SPNEGO blob */
118 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
119 	else
120 		size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
121 
122 	/* Verify that at least minimal negotiate contexts fit within frame */
123 	if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
124 		pr_warn_once("negotiate context goes beyond end\n");
125 		return 0;
126 	}
127 
128 	cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
129 		len - nc_offset, size_of_pad_before_neg_ctxts);
130 
131 	/* length of negcontexts including pad from end of sec blob to them */
132 	return (len - nc_offset) + size_of_pad_before_neg_ctxts;
133 }
134 
135 int
smb2_check_message(char * buf,unsigned int len,struct TCP_Server_Info * server)136 smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *server)
137 {
138 	struct TCP_Server_Info *pserver;
139 	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
140 	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
141 	int hdr_size = sizeof(struct smb2_hdr);
142 	int pdu_size = sizeof(struct smb2_pdu);
143 	int command;
144 	__u32 calc_len; /* calculated length */
145 	__u64 mid;
146 
147 	/* If server is a channel, select the primary channel */
148 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
149 
150 	/*
151 	 * Add function to do table lookup of StructureSize by command
152 	 * ie Validate the wct via smb2_struct_sizes table above
153 	 */
154 	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
155 		struct smb2_transform_hdr *thdr =
156 			(struct smb2_transform_hdr *)buf;
157 		struct cifs_ses *ses = NULL;
158 		struct cifs_ses *iter;
159 
160 		/* decrypt frame now that it is completely read in */
161 		spin_lock(&cifs_tcp_ses_lock);
162 		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
163 			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
164 				ses = iter;
165 				break;
166 			}
167 		}
168 		spin_unlock(&cifs_tcp_ses_lock);
169 		if (!ses) {
170 			cifs_dbg(VFS, "no decryption - session id not found\n");
171 			return 1;
172 		}
173 	}
174 
175 	mid = le64_to_cpu(shdr->MessageId);
176 	if (check_smb2_hdr(shdr, mid))
177 		return 1;
178 
179 	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
180 		cifs_dbg(VFS, "Invalid structure size %u\n",
181 			 le16_to_cpu(shdr->StructureSize));
182 		return 1;
183 	}
184 
185 	command = le16_to_cpu(shdr->Command);
186 	if (command >= NUMBER_OF_SMB2_COMMANDS) {
187 		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
188 		return 1;
189 	}
190 
191 	if (len < pdu_size) {
192 		if ((len >= hdr_size)
193 		    && (shdr->Status != 0)) {
194 			pdu->StructureSize2 = 0;
195 			/*
196 			 * As with SMB/CIFS, on some error cases servers may
197 			 * not return wct properly
198 			 */
199 			return 0;
200 		} else {
201 			cifs_dbg(VFS, "Length less than SMB header size\n");
202 		}
203 		return 1;
204 	}
205 	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
206 		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
207 			 mid);
208 		return 1;
209 	}
210 
211 	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
212 		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
213 		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
214 			/* error packets have 9 byte structure size */
215 			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
216 				 le16_to_cpu(pdu->StructureSize2), command);
217 			return 1;
218 		} else if (command == SMB2_OPLOCK_BREAK_HE
219 			   && (shdr->Status == 0)
220 			   && (le16_to_cpu(pdu->StructureSize2) != 44)
221 			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
222 			/* special case for SMB2.1 lease break message */
223 			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
224 				 le16_to_cpu(pdu->StructureSize2));
225 			return 1;
226 		}
227 	}
228 
229 	calc_len = smb2_calc_size(buf);
230 
231 	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
232 	 * be 0, and not a real miscalculation */
233 	if (command == SMB2_IOCTL_HE && calc_len == 0)
234 		return 0;
235 
236 	if (command == SMB2_NEGOTIATE_HE)
237 		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
238 
239 	if (len != calc_len) {
240 		/* create failed on symlink */
241 		if (command == SMB2_CREATE_HE &&
242 		    shdr->Status == STATUS_STOPPED_ON_SYMLINK)
243 			return 0;
244 		/* Windows 7 server returns 24 bytes more */
245 		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
246 			return 0;
247 		/* server can return one byte more due to implied bcc[0] */
248 		if (calc_len == len + 1)
249 			return 0;
250 
251 		/*
252 		 * Some windows servers (win2016) will pad also the final
253 		 * PDU in a compound to 8 bytes.
254 		 */
255 		if (ALIGN(calc_len, 8) == len)
256 			return 0;
257 
258 		/*
259 		 * MacOS server pads after SMB2.1 write response with 3 bytes
260 		 * of junk. Other servers match RFC1001 len to actual
261 		 * SMB2/SMB3 frame length (header + smb2 response specific data)
262 		 * Some windows servers also pad up to 8 bytes when compounding.
263 		 */
264 		if (calc_len < len)
265 			return 0;
266 
267 		/* Only log a message if len was really miscalculated */
268 		if (unlikely(cifsFYI))
269 			cifs_dbg(FYI, "Server response too short: calculated "
270 				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
271 				 calc_len, len, command, mid);
272 		else
273 			pr_warn("Server response too short: calculated length "
274 				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
275 				calc_len, len, command, mid);
276 
277 		return 1;
278 	}
279 	return 0;
280 }
281 
282 /*
283  * The size of the variable area depends on the offset and length fields
284  * located in different fields for various SMB2 responses. SMB2 responses
285  * with no variable length info, show an offset of zero for the offset field.
286  */
287 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
288 	/* SMB2_NEGOTIATE */ true,
289 	/* SMB2_SESSION_SETUP */ true,
290 	/* SMB2_LOGOFF */ false,
291 	/* SMB2_TREE_CONNECT */	false,
292 	/* SMB2_TREE_DISCONNECT */ false,
293 	/* SMB2_CREATE */ true,
294 	/* SMB2_CLOSE */ false,
295 	/* SMB2_FLUSH */ false,
296 	/* SMB2_READ */	true,
297 	/* SMB2_WRITE */ false,
298 	/* SMB2_LOCK */	false,
299 	/* SMB2_IOCTL */ true,
300 	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
301 	/* SMB2_ECHO */ false,
302 	/* SMB2_QUERY_DIRECTORY */ true,
303 	/* SMB2_CHANGE_NOTIFY */ true,
304 	/* SMB2_QUERY_INFO */ true,
305 	/* SMB2_SET_INFO */ false,
306 	/* SMB2_OPLOCK_BREAK */ false
307 };
308 
309 /*
310  * Returns the pointer to the beginning of the data area. Length of the data
311  * area and the offset to it (from the beginning of the smb are also returned.
312  */
313 char *
smb2_get_data_area_len(int * off,int * len,struct smb2_hdr * shdr)314 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
315 {
316 	const int max_off = 4096;
317 	const int max_len = 128 * 1024;
318 
319 	*off = 0;
320 	*len = 0;
321 
322 	/* error responses do not have data area */
323 	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
324 	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
325 						SMB2_ERROR_STRUCTURE_SIZE2_LE)
326 		return NULL;
327 
328 	/*
329 	 * Following commands have data areas so we have to get the location
330 	 * of the data buffer offset and data buffer length for the particular
331 	 * command.
332 	 */
333 	switch (shdr->Command) {
334 	case SMB2_NEGOTIATE:
335 		*off = le16_to_cpu(
336 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
337 		*len = le16_to_cpu(
338 		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
339 		break;
340 	case SMB2_SESSION_SETUP:
341 		*off = le16_to_cpu(
342 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
343 		*len = le16_to_cpu(
344 		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
345 		break;
346 	case SMB2_CREATE:
347 		*off = le32_to_cpu(
348 		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
349 		*len = le32_to_cpu(
350 		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
351 		break;
352 	case SMB2_QUERY_INFO:
353 		*off = le16_to_cpu(
354 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
355 		*len = le32_to_cpu(
356 		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
357 		break;
358 	case SMB2_READ:
359 		/* TODO: is this a bug ? */
360 		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
361 		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
362 		break;
363 	case SMB2_QUERY_DIRECTORY:
364 		*off = le16_to_cpu(
365 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
366 		*len = le32_to_cpu(
367 		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
368 		break;
369 	case SMB2_IOCTL:
370 		*off = le32_to_cpu(
371 		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
372 		*len = le32_to_cpu(
373 		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
374 		break;
375 	case SMB2_CHANGE_NOTIFY:
376 		*off = le16_to_cpu(
377 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
378 		*len = le32_to_cpu(
379 		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
380 		break;
381 	default:
382 		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
383 		break;
384 	}
385 
386 	/*
387 	 * Invalid length or offset probably means data area is invalid, but
388 	 * we have little choice but to ignore the data area in this case.
389 	 */
390 	if (unlikely(*off < 0 || *off > max_off ||
391 		     *len < 0 || *len > max_len)) {
392 		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
393 			 __func__, *off, *len);
394 		*off = 0;
395 		*len = 0;
396 	} else if (*off == 0) {
397 		*len = 0;
398 	}
399 
400 	/* return pointer to beginning of data area, ie offset from SMB start */
401 	if (*off > 0 && *len > 0)
402 		return (char *)shdr + *off;
403 	return NULL;
404 }
405 
406 /*
407  * Calculate the size of the SMB message based on the fixed header
408  * portion, the number of word parameters and the data portion of the message.
409  */
410 unsigned int
smb2_calc_size(void * buf)411 smb2_calc_size(void *buf)
412 {
413 	struct smb2_pdu *pdu = buf;
414 	struct smb2_hdr *shdr = &pdu->hdr;
415 	int offset; /* the offset from the beginning of SMB to data area */
416 	int data_length; /* the length of the variable length data area */
417 	/* Structure Size has already been checked to make sure it is 64 */
418 	int len = le16_to_cpu(shdr->StructureSize);
419 
420 	/*
421 	 * StructureSize2, ie length of fixed parameter area has already
422 	 * been checked to make sure it is the correct length.
423 	 */
424 	len += le16_to_cpu(pdu->StructureSize2);
425 
426 	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
427 		goto calc_size_exit;
428 
429 	smb2_get_data_area_len(&offset, &data_length, shdr);
430 	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
431 
432 	if (data_length > 0) {
433 		/*
434 		 * Check to make sure that data area begins after fixed area,
435 		 * Note that last byte of the fixed area is part of data area
436 		 * for some commands, typically those with odd StructureSize,
437 		 * so we must add one to the calculation.
438 		 */
439 		if (offset + 1 < len) {
440 			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
441 				 offset + 1, len);
442 			data_length = 0;
443 		} else {
444 			len = offset + data_length;
445 		}
446 	}
447 calc_size_exit:
448 	cifs_dbg(FYI, "SMB2 len %d\n", len);
449 	return len;
450 }
451 
452 /* Note: caller must free return buffer */
453 __le16 *
cifs_convert_path_to_utf16(const char * from,struct cifs_sb_info * cifs_sb)454 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
455 {
456 	int len;
457 	const char *start_of_path;
458 	__le16 *to;
459 	int map_type;
460 
461 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
462 		map_type = SFM_MAP_UNI_RSVD;
463 	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
464 		map_type = SFU_MAP_UNI_RSVD;
465 	else
466 		map_type = NO_MAP_UNI_RSVD;
467 
468 	/* Windows doesn't allow paths beginning with \ */
469 	if (from[0] == '\\')
470 		start_of_path = from + 1;
471 
472 	/* SMB311 POSIX extensions paths do not include leading slash */
473 	else if (cifs_sb_master_tlink(cifs_sb) &&
474 		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
475 		 (from[0] == '/')) {
476 		start_of_path = from + 1;
477 	} else
478 		start_of_path = from;
479 
480 	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
481 				   cifs_sb->local_nls, map_type);
482 	return to;
483 }
484 
485 __le32
smb2_get_lease_state(struct cifsInodeInfo * cinode)486 smb2_get_lease_state(struct cifsInodeInfo *cinode)
487 {
488 	__le32 lease = 0;
489 
490 	if (CIFS_CACHE_WRITE(cinode))
491 		lease |= SMB2_LEASE_WRITE_CACHING_LE;
492 	if (CIFS_CACHE_HANDLE(cinode))
493 		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
494 	if (CIFS_CACHE_READ(cinode))
495 		lease |= SMB2_LEASE_READ_CACHING_LE;
496 	return lease;
497 }
498 
499 struct smb2_lease_break_work {
500 	struct work_struct lease_break;
501 	struct tcon_link *tlink;
502 	__u8 lease_key[16];
503 	__le32 lease_state;
504 };
505 
506 static void
cifs_ses_oplock_break(struct work_struct * work)507 cifs_ses_oplock_break(struct work_struct *work)
508 {
509 	struct smb2_lease_break_work *lw = container_of(work,
510 				struct smb2_lease_break_work, lease_break);
511 	int rc = 0;
512 
513 	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
514 			      lw->lease_state);
515 
516 	cifs_dbg(FYI, "Lease release rc %d\n", rc);
517 	cifs_put_tlink(lw->tlink);
518 	kfree(lw);
519 }
520 
521 static void
smb2_queue_pending_open_break(struct tcon_link * tlink,__u8 * lease_key,__le32 new_lease_state)522 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
523 			      __le32 new_lease_state)
524 {
525 	struct smb2_lease_break_work *lw;
526 
527 	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
528 	if (!lw) {
529 		cifs_put_tlink(tlink);
530 		return;
531 	}
532 
533 	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
534 	lw->tlink = tlink;
535 	lw->lease_state = new_lease_state;
536 	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
537 	queue_work(cifsiod_wq, &lw->lease_break);
538 }
539 
540 static bool
smb2_tcon_has_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)541 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
542 {
543 	__u8 lease_state;
544 	struct cifsFileInfo *cfile;
545 	struct cifsInodeInfo *cinode;
546 	int ack_req = le32_to_cpu(rsp->Flags &
547 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
548 
549 	lease_state = le32_to_cpu(rsp->NewLeaseState);
550 
551 	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
552 		cinode = CIFS_I(d_inode(cfile->dentry));
553 
554 		if (memcmp(cinode->lease_key, rsp->LeaseKey,
555 							SMB2_LEASE_KEY_SIZE))
556 			continue;
557 
558 		cifs_dbg(FYI, "found in the open list\n");
559 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
560 			 lease_state);
561 
562 		if (ack_req)
563 			cfile->oplock_break_cancelled = false;
564 		else
565 			cfile->oplock_break_cancelled = true;
566 
567 		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
568 
569 		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
570 		cfile->oplock_level = lease_state;
571 
572 		cifs_queue_oplock_break(cfile);
573 		return true;
574 	}
575 
576 	return false;
577 }
578 
579 static struct cifs_pending_open *
smb2_tcon_find_pending_open_lease(struct cifs_tcon * tcon,struct smb2_lease_break * rsp)580 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
581 				  struct smb2_lease_break *rsp)
582 {
583 	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
584 	int ack_req = le32_to_cpu(rsp->Flags &
585 				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
586 	struct cifs_pending_open *open;
587 	struct cifs_pending_open *found = NULL;
588 
589 	list_for_each_entry(open, &tcon->pending_opens, olist) {
590 		if (memcmp(open->lease_key, rsp->LeaseKey,
591 			   SMB2_LEASE_KEY_SIZE))
592 			continue;
593 
594 		if (!found && ack_req) {
595 			found = open;
596 		}
597 
598 		cifs_dbg(FYI, "found in the pending open list\n");
599 		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
600 			 lease_state);
601 
602 		open->oplock = lease_state;
603 	}
604 
605 	return found;
606 }
607 
608 static bool
smb2_is_valid_lease_break(char * buffer,struct TCP_Server_Info * server)609 smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
610 {
611 	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
612 	struct TCP_Server_Info *pserver;
613 	struct cifs_ses *ses;
614 	struct cifs_tcon *tcon;
615 	struct cifs_pending_open *open;
616 
617 	cifs_dbg(FYI, "Checking for lease break\n");
618 
619 	/* If server is a channel, select the primary channel */
620 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
621 
622 	/* look up tcon based on tid & uid */
623 	spin_lock(&cifs_tcp_ses_lock);
624 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
625 		if (cifs_ses_exiting(ses))
626 			continue;
627 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
628 			spin_lock(&tcon->open_file_lock);
629 			cifs_stats_inc(
630 				       &tcon->stats.cifs_stats.num_oplock_brks);
631 			if (smb2_tcon_has_lease(tcon, rsp)) {
632 				spin_unlock(&tcon->open_file_lock);
633 				spin_unlock(&cifs_tcp_ses_lock);
634 				return true;
635 			}
636 			open = smb2_tcon_find_pending_open_lease(tcon,
637 								 rsp);
638 			if (open) {
639 				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
640 				struct tcon_link *tlink;
641 
642 				tlink = cifs_get_tlink(open->tlink);
643 				memcpy(lease_key, open->lease_key,
644 				       SMB2_LEASE_KEY_SIZE);
645 				spin_unlock(&tcon->open_file_lock);
646 				spin_unlock(&cifs_tcp_ses_lock);
647 				smb2_queue_pending_open_break(tlink,
648 							      lease_key,
649 							      rsp->NewLeaseState);
650 				return true;
651 			}
652 			spin_unlock(&tcon->open_file_lock);
653 
654 			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
655 				spin_unlock(&cifs_tcp_ses_lock);
656 				return true;
657 			}
658 		}
659 	}
660 	spin_unlock(&cifs_tcp_ses_lock);
661 	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
662 	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
663 				   le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
664 				   le64_to_cpu(rsp->hdr.SessionId),
665 				   *((u64 *)rsp->LeaseKey),
666 				   *((u64 *)&rsp->LeaseKey[8]));
667 
668 	return false;
669 }
670 
671 bool
smb2_is_valid_oplock_break(char * buffer,struct TCP_Server_Info * server)672 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
673 {
674 	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
675 	struct TCP_Server_Info *pserver;
676 	struct cifs_ses *ses;
677 	struct cifs_tcon *tcon;
678 	struct cifsInodeInfo *cinode;
679 	struct cifsFileInfo *cfile;
680 
681 	cifs_dbg(FYI, "Checking for oplock break\n");
682 
683 	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
684 		return false;
685 
686 	if (rsp->StructureSize !=
687 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
688 		if (le16_to_cpu(rsp->StructureSize) == 44)
689 			return smb2_is_valid_lease_break(buffer, server);
690 		else
691 			return false;
692 	}
693 
694 	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
695 
696 	/* If server is a channel, select the primary channel */
697 	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
698 
699 	/* look up tcon based on tid & uid */
700 	spin_lock(&cifs_tcp_ses_lock);
701 	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
702 		if (cifs_ses_exiting(ses))
703 			continue;
704 		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
705 
706 			spin_lock(&tcon->open_file_lock);
707 			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
708 				if (rsp->PersistentFid !=
709 				    cfile->fid.persistent_fid ||
710 				    rsp->VolatileFid !=
711 				    cfile->fid.volatile_fid)
712 					continue;
713 
714 				cifs_dbg(FYI, "file id match, oplock break\n");
715 				cifs_stats_inc(
716 				    &tcon->stats.cifs_stats.num_oplock_brks);
717 				cinode = CIFS_I(d_inode(cfile->dentry));
718 				spin_lock(&cfile->file_info_lock);
719 				if (!CIFS_CACHE_WRITE(cinode) &&
720 				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
721 					cfile->oplock_break_cancelled = true;
722 				else
723 					cfile->oplock_break_cancelled = false;
724 
725 				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
726 					&cinode->flags);
727 
728 				cfile->oplock_epoch = 0;
729 				cfile->oplock_level = rsp->OplockLevel;
730 
731 				spin_unlock(&cfile->file_info_lock);
732 
733 				cifs_queue_oplock_break(cfile);
734 
735 				spin_unlock(&tcon->open_file_lock);
736 				spin_unlock(&cifs_tcp_ses_lock);
737 				return true;
738 			}
739 			spin_unlock(&tcon->open_file_lock);
740 		}
741 	}
742 	spin_unlock(&cifs_tcp_ses_lock);
743 	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
744 	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
745 				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
746 				  le64_to_cpu(rsp->hdr.SessionId));
747 
748 	return true;
749 }
750 
751 void
smb2_cancelled_close_fid(struct work_struct * work)752 smb2_cancelled_close_fid(struct work_struct *work)
753 {
754 	struct close_cancelled_open *cancelled = container_of(work,
755 					struct close_cancelled_open, work);
756 	struct cifs_tcon *tcon = cancelled->tcon;
757 	int rc;
758 
759 	if (cancelled->mid)
760 		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
761 			      cancelled->mid);
762 	else
763 		cifs_tcon_dbg(VFS, "Close interrupted close\n");
764 
765 	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
766 			cancelled->fid.volatile_fid);
767 	if (rc)
768 		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
769 
770 	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
771 	kfree(cancelled);
772 }
773 
774 /*
775  * Caller should already has an extra reference to @tcon
776  * This function is used to queue work to close a handle to prevent leaks
777  * on the server.
778  * We handle two cases. If an open was interrupted after we sent the
779  * SMB2_CREATE to the server but before we processed the reply, and second
780  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
781  */
782 static int
__smb2_handle_cancelled_cmd(struct cifs_tcon * tcon,__u16 cmd,__u64 mid,__u64 persistent_fid,__u64 volatile_fid)783 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
784 			    __u64 persistent_fid, __u64 volatile_fid)
785 {
786 	struct close_cancelled_open *cancelled;
787 
788 	cancelled = kzalloc(sizeof(*cancelled), GFP_KERNEL);
789 	if (!cancelled)
790 		return -ENOMEM;
791 
792 	cancelled->fid.persistent_fid = persistent_fid;
793 	cancelled->fid.volatile_fid = volatile_fid;
794 	cancelled->tcon = tcon;
795 	cancelled->cmd = cmd;
796 	cancelled->mid = mid;
797 	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
798 	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
799 
800 	return 0;
801 }
802 
803 int
smb2_handle_cancelled_close(struct cifs_tcon * tcon,__u64 persistent_fid,__u64 volatile_fid)804 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
805 			    __u64 volatile_fid)
806 {
807 	int rc;
808 
809 	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
810 	spin_lock(&cifs_tcp_ses_lock);
811 	if (tcon->tc_count <= 0) {
812 		struct TCP_Server_Info *server = NULL;
813 
814 		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
815 				    netfs_trace_tcon_ref_see_cancelled_close);
816 		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
817 		spin_unlock(&cifs_tcp_ses_lock);
818 
819 		if (tcon->ses)
820 			server = tcon->ses->server;
821 
822 		cifs_server_dbg(FYI, "tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
823 				tcon->tid, persistent_fid, volatile_fid);
824 
825 		return 0;
826 	}
827 	tcon->tc_count++;
828 	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
829 			    netfs_trace_tcon_ref_get_cancelled_close);
830 	spin_unlock(&cifs_tcp_ses_lock);
831 
832 	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
833 					 persistent_fid, volatile_fid);
834 	if (rc)
835 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
836 
837 	return rc;
838 }
839 
840 int
smb2_handle_cancelled_mid(struct mid_q_entry * mid,struct TCP_Server_Info * server)841 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
842 {
843 	struct smb2_hdr *hdr = mid->resp_buf;
844 	struct smb2_create_rsp *rsp = mid->resp_buf;
845 	struct cifs_tcon *tcon;
846 	int rc;
847 
848 	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
849 	    hdr->Status != STATUS_SUCCESS)
850 		return 0;
851 
852 	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
853 				  le32_to_cpu(hdr->Id.SyncId.TreeId));
854 	if (!tcon)
855 		return -ENOENT;
856 
857 	rc = __smb2_handle_cancelled_cmd(tcon,
858 					 le16_to_cpu(hdr->Command),
859 					 le64_to_cpu(hdr->MessageId),
860 					 rsp->PersistentFileId,
861 					 rsp->VolatileFileId);
862 	if (rc)
863 		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
864 
865 	return rc;
866 }
867 
868 /**
869  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
870  *
871  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
872  * SMB2 header.
873  *
874  * @ses:	server session structure
875  * @server:	pointer to server info
876  * @iov:	array containing the SMB request we will send to the server
877  * @nvec:	number of array entries for the iov
878  */
879 int
smb311_update_preauth_hash(struct cifs_ses * ses,struct TCP_Server_Info * server,struct kvec * iov,int nvec)880 smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
881 			   struct kvec *iov, int nvec)
882 {
883 	int i, rc;
884 	struct smb2_hdr *hdr;
885 	struct shash_desc *sha512 = NULL;
886 
887 	hdr = (struct smb2_hdr *)iov[0].iov_base;
888 	/* neg prot are always taken */
889 	if (hdr->Command == SMB2_NEGOTIATE)
890 		goto ok;
891 
892 	/*
893 	 * If we process a command which wasn't a negprot it means the
894 	 * neg prot was already done, so the server dialect was set
895 	 * and we can test it. Preauth requires 3.1.1 for now.
896 	 */
897 	if (server->dialect != SMB311_PROT_ID)
898 		return 0;
899 
900 	if (hdr->Command != SMB2_SESSION_SETUP)
901 		return 0;
902 
903 	/* skip last sess setup response */
904 	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
905 	    && (hdr->Status == NT_STATUS_OK
906 		|| (hdr->Status !=
907 		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
908 		return 0;
909 
910 ok:
911 	rc = smb311_crypto_shash_allocate(server);
912 	if (rc)
913 		return rc;
914 
915 	sha512 = server->secmech.sha512;
916 	rc = crypto_shash_init(sha512);
917 	if (rc) {
918 		cifs_dbg(VFS, "%s: Could not init sha512 shash\n", __func__);
919 		return rc;
920 	}
921 
922 	rc = crypto_shash_update(sha512, ses->preauth_sha_hash,
923 				 SMB2_PREAUTH_HASH_SIZE);
924 	if (rc) {
925 		cifs_dbg(VFS, "%s: Could not update sha512 shash\n", __func__);
926 		return rc;
927 	}
928 
929 	for (i = 0; i < nvec; i++) {
930 		rc = crypto_shash_update(sha512, iov[i].iov_base, iov[i].iov_len);
931 		if (rc) {
932 			cifs_dbg(VFS, "%s: Could not update sha512 shash\n",
933 				 __func__);
934 			return rc;
935 		}
936 	}
937 
938 	rc = crypto_shash_final(sha512, ses->preauth_sha_hash);
939 	if (rc) {
940 		cifs_dbg(VFS, "%s: Could not finalize sha512 shash\n",
941 			 __func__);
942 		return rc;
943 	}
944 
945 	return 0;
946 }
947