smb2misc.c

  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
 22static int
 23check_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 */
 61static 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
 87static __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
136int
137smb2_check_message(char *buf, unsigned int pdu_len, unsigned int len,
138		   struct TCP_Server_Info *server)
139{
140	struct TCP_Server_Info *pserver;
141	struct smb2_hdr *shdr = (struct smb2_hdr *)buf;
142	struct smb2_pdu *pdu = (struct smb2_pdu *)shdr;
143	int hdr_size = sizeof(struct smb2_hdr);
144	int pdu_size = sizeof(struct smb2_pdu);
145	int command;
146	__u32 calc_len; /* calculated length */
147	__u64 mid;
148
149	/* If server is a channel, select the primary channel */
150	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
151
152	/*
153	 * Add function to do table lookup of StructureSize by command
154	 * ie Validate the wct via smb2_struct_sizes table above
155	 */
156	if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
157		struct smb2_transform_hdr *thdr =
158			(struct smb2_transform_hdr *)buf;
159		struct cifs_ses *ses = NULL;
160		struct cifs_ses *iter;
161
162		/* decrypt frame now that it is completely read in */
163		spin_lock(&cifs_tcp_ses_lock);
164		list_for_each_entry(iter, &pserver->smb_ses_list, smb_ses_list) {
165			if (iter->Suid == le64_to_cpu(thdr->SessionId)) {
166				ses = iter;
167				break;
168			}
169		}
170		spin_unlock(&cifs_tcp_ses_lock);
171		if (!ses) {
172			cifs_dbg(VFS, "no decryption - session id not found\n");
173			return 1;
174		}
175	}
176
177	mid = le64_to_cpu(shdr->MessageId);
178	if (check_smb2_hdr(shdr, mid))
179		return 1;
180
181	if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
182		cifs_dbg(VFS, "Invalid structure size %u\n",
183			 le16_to_cpu(shdr->StructureSize));
184		return 1;
185	}
186
187	command = le16_to_cpu(shdr->Command);
188	if (command >= NUMBER_OF_SMB2_COMMANDS) {
189		cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
190		return 1;
191	}
192
193	if (len < pdu_size) {
194		if ((len >= hdr_size)
195		    && (shdr->Status != 0)) {
196			pdu->StructureSize2 = 0;
197			/*
198			 * As with SMB/CIFS, on some error cases servers may
199			 * not return wct properly
200			 */
201			return 0;
202		} else {
203			cifs_dbg(VFS, "Length less than SMB header size\n");
204		}
205		return 1;
206	}
207	if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
208		cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
209			 mid);
210		return 1;
211	}
212
213	if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
214		if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
215		    pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2_LE)) {
216			/* error packets have 9 byte structure size */
217			cifs_dbg(VFS, "Invalid response size %u for command %d\n",
218				 le16_to_cpu(pdu->StructureSize2), command);
219			return 1;
220		} else if (command == SMB2_OPLOCK_BREAK_HE
221			   && (shdr->Status == 0)
222			   && (le16_to_cpu(pdu->StructureSize2) != 44)
223			   && (le16_to_cpu(pdu->StructureSize2) != 36)) {
224			/* special case for SMB2.1 lease break message */
225			cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
226				 le16_to_cpu(pdu->StructureSize2));
227			return 1;
228		}
229	}
230
231	calc_len = smb2_calc_size(buf);
232
233	/* For SMB2_IOCTL, OutputOffset and OutputLength are optional, so might
234	 * be 0, and not a real miscalculation */
235	if (command == SMB2_IOCTL_HE && calc_len == 0)
236		return 0;
237
238	if (command == SMB2_NEGOTIATE_HE)
239		calc_len += get_neg_ctxt_len(shdr, len, calc_len);
240
241	if (len != calc_len) {
242		/* create failed on symlink */
243		if (command == SMB2_CREATE_HE &&
244		    shdr->Status == STATUS_STOPPED_ON_SYMLINK)
245			return 0;
246		/* Windows 7 server returns 24 bytes more */
247		if (calc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
248			return 0;
249		/* server can return one byte more due to implied bcc[0] */
250		if (calc_len == len + 1)
251			return 0;
252
253		/*
254		 * Some windows servers (win2016) will pad also the final
255		 * PDU in a compound to 8 bytes.
256		 */
257		if (ALIGN(calc_len, 8) == len)
258			return 0;
259
260		/*
261		 * MacOS server pads after SMB2.1 write response with 3 bytes
262		 * of junk. Other servers match RFC1001 len to actual
263		 * SMB2/SMB3 frame length (header + smb2 response specific data)
264		 * Some windows servers also pad up to 8 bytes when compounding.
265		 */
266		if (calc_len < len)
267			return 0;
268
269		/* Only log a message if len was really miscalculated */
270		if (unlikely(cifsFYI))
271			cifs_dbg(FYI, "Server response too short: calculated "
272				 "length %u doesn't match read length %u (cmd=%d, mid=%llu)\n",
273				 calc_len, len, command, mid);
274		else
275			pr_warn("Server response too short: calculated length "
276				"%u doesn't match read length %u (cmd=%d, mid=%llu)\n",
277				calc_len, len, command, mid);
278
279		return 1;
280	}
281	return 0;
282}
283
284/*
285 * The size of the variable area depends on the offset and length fields
286 * located in different fields for various SMB2 responses. SMB2 responses
287 * with no variable length info, show an offset of zero for the offset field.
288 */
289static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
290	/* SMB2_NEGOTIATE */ true,
291	/* SMB2_SESSION_SETUP */ true,
292	/* SMB2_LOGOFF */ false,
293	/* SMB2_TREE_CONNECT */	false,
294	/* SMB2_TREE_DISCONNECT */ false,
295	/* SMB2_CREATE */ true,
296	/* SMB2_CLOSE */ false,
297	/* SMB2_FLUSH */ false,
298	/* SMB2_READ */	true,
299	/* SMB2_WRITE */ false,
300	/* SMB2_LOCK */	false,
301	/* SMB2_IOCTL */ true,
302	/* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
303	/* SMB2_ECHO */ false,
304	/* SMB2_QUERY_DIRECTORY */ true,
305	/* SMB2_CHANGE_NOTIFY */ true,
306	/* SMB2_QUERY_INFO */ true,
307	/* SMB2_SET_INFO */ false,
308	/* SMB2_OPLOCK_BREAK */ false
309};
310
311/*
312 * Returns the pointer to the beginning of the data area. Length of the data
313 * area and the offset to it (from the beginning of the smb are also returned.
314 */
315char *
316smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *shdr)
317{
318	const int max_off = 4096;
319	const int max_len = 128 * 1024;
320
321	*off = 0;
322	*len = 0;
323
324	/* error responses do not have data area */
325	if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
326	    (((struct smb2_err_rsp *)shdr)->StructureSize) ==
327						SMB2_ERROR_STRUCTURE_SIZE2_LE)
328		return NULL;
329
330	/*
331	 * Following commands have data areas so we have to get the location
332	 * of the data buffer offset and data buffer length for the particular
333	 * command.
334	 */
335	switch (shdr->Command) {
336	case SMB2_NEGOTIATE:
337		*off = le16_to_cpu(
338		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
339		*len = le16_to_cpu(
340		  ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
341		break;
342	case SMB2_SESSION_SETUP:
343		*off = le16_to_cpu(
344		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
345		*len = le16_to_cpu(
346		  ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
347		break;
348	case SMB2_CREATE:
349		*off = le32_to_cpu(
350		    ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
351		*len = le32_to_cpu(
352		    ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
353		break;
354	case SMB2_QUERY_INFO:
355		*off = le16_to_cpu(
356		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
357		*len = le32_to_cpu(
358		    ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
359		break;
360	case SMB2_READ:
361		/* TODO: is this a bug ? */
362		*off = ((struct smb2_read_rsp *)shdr)->DataOffset;
363		*len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
364		break;
365	case SMB2_QUERY_DIRECTORY:
366		*off = le16_to_cpu(
367		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
368		*len = le32_to_cpu(
369		  ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
370		break;
371	case SMB2_IOCTL:
372		*off = le32_to_cpu(
373		  ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
374		*len = le32_to_cpu(
375		  ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
376		break;
377	case SMB2_CHANGE_NOTIFY:
378		*off = le16_to_cpu(
379		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
380		*len = le32_to_cpu(
381		  ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
382		break;
383	default:
384		cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
385		break;
386	}
387
388	/*
389	 * Invalid length or offset probably means data area is invalid, but
390	 * we have little choice but to ignore the data area in this case.
391	 */
392	if (unlikely(*off < 0 || *off > max_off ||
393		     *len < 0 || *len > max_len)) {
394		cifs_dbg(VFS, "%s: invalid data area (off=%d len=%d)\n",
395			 __func__, *off, *len);
396		*off = 0;
397		*len = 0;
398	} else if (*off == 0) {
399		*len = 0;
400	}
401
402	/* return pointer to beginning of data area, ie offset from SMB start */
403	if (*off > 0 && *len > 0)
404		return (char *)shdr + *off;
405	return NULL;
406}
407
408/*
409 * Calculate the size of the SMB message based on the fixed header
410 * portion, the number of word parameters and the data portion of the message.
411 */
412unsigned int
413smb2_calc_size(void *buf)
414{
415	struct smb2_pdu *pdu = buf;
416	struct smb2_hdr *shdr = &pdu->hdr;
417	int offset; /* the offset from the beginning of SMB to data area */
418	int data_length; /* the length of the variable length data area */
419	/* Structure Size has already been checked to make sure it is 64 */
420	int len = le16_to_cpu(shdr->StructureSize);
421
422	/*
423	 * StructureSize2, ie length of fixed parameter area has already
424	 * been checked to make sure it is the correct length.
425	 */
426	len += le16_to_cpu(pdu->StructureSize2);
427
428	if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
429		goto calc_size_exit;
430
431	smb2_get_data_area_len(&offset, &data_length, shdr);
432	cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
433
434	if (data_length > 0) {
435		/*
436		 * Check to make sure that data area begins after fixed area,
437		 * Note that last byte of the fixed area is part of data area
438		 * for some commands, typically those with odd StructureSize,
439		 * so we must add one to the calculation.
440		 */
441		if (offset + 1 < len) {
442			cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
443				 offset + 1, len);
444			data_length = 0;
445		} else {
446			len = offset + data_length;
447		}
448	}
449calc_size_exit:
450	cifs_dbg(FYI, "SMB2 len %d\n", len);
451	return len;
452}
453
454/* Note: caller must free return buffer */
455__le16 *
456cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
457{
458	int len;
459	const char *start_of_path;
460	__le16 *to;
461	int map_type;
462
463	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
464		map_type = SFM_MAP_UNI_RSVD;
465	else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
466		map_type = SFU_MAP_UNI_RSVD;
467	else
468		map_type = NO_MAP_UNI_RSVD;
469
470	/* Windows doesn't allow paths beginning with \ */
471	if (from[0] == '\\')
472		start_of_path = from + 1;
473
474	/* SMB311 POSIX extensions paths do not include leading slash */
475	else if (cifs_sb_master_tlink(cifs_sb) &&
476		 cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
477		 (from[0] == '/')) {
478		start_of_path = from + 1;
479	} else
480		start_of_path = from;
481
482	to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
483				   cifs_sb->local_nls, map_type);
484	return to;
485}
486
487__le32
488smb2_get_lease_state(struct cifsInodeInfo *cinode)
489{
490	__le32 lease = 0;
491
492	if (CIFS_CACHE_WRITE(cinode))
493		lease |= SMB2_LEASE_WRITE_CACHING_LE;
494	if (CIFS_CACHE_HANDLE(cinode))
495		lease |= SMB2_LEASE_HANDLE_CACHING_LE;
496	if (CIFS_CACHE_READ(cinode))
497		lease |= SMB2_LEASE_READ_CACHING_LE;
498	return lease;
499}
500
501struct smb2_lease_break_work {
502	struct work_struct lease_break;
503	struct tcon_link *tlink;
504	__u8 lease_key[16];
505	__le32 lease_state;
506};
507
508static void
509cifs_ses_oplock_break(struct work_struct *work)
510{
511	struct smb2_lease_break_work *lw = container_of(work,
512				struct smb2_lease_break_work, lease_break);
513	int rc = 0;
514
515	rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
516			      lw->lease_state);
517
518	cifs_dbg(FYI, "Lease release rc %d\n", rc);
519	cifs_put_tlink(lw->tlink);
520	kfree(lw);
521}
522
523static void
524smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
525			      __le32 new_lease_state)
526{
527	struct smb2_lease_break_work *lw;
528
529	lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
530	if (!lw) {
531		cifs_put_tlink(tlink);
532		return;
533	}
534
535	INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
536	lw->tlink = tlink;
537	lw->lease_state = new_lease_state;
538	memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
539	queue_work(cifsiod_wq, &lw->lease_break);
540}
541
542static bool
543smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
544{
545	__u8 lease_state;
546	struct cifsFileInfo *cfile;
547	struct cifsInodeInfo *cinode;
548	int ack_req = le32_to_cpu(rsp->Flags &
549				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
550
551	lease_state = le32_to_cpu(rsp->NewLeaseState);
552
553	list_for_each_entry(cfile, &tcon->openFileList, tlist) {
554		cinode = CIFS_I(d_inode(cfile->dentry));
555
556		if (memcmp(cinode->lease_key, rsp->LeaseKey,
557							SMB2_LEASE_KEY_SIZE))
558			continue;
559
560		cifs_dbg(FYI, "found in the open list\n");
561		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
562			 lease_state);
563
564		if (ack_req)
565			cfile->oplock_break_cancelled = false;
566		else
567			cfile->oplock_break_cancelled = true;
568
569		set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
570
571		cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
572		cfile->oplock_level = lease_state;
573
574		cifs_queue_oplock_break(cfile);
575		return true;
576	}
577
578	return false;
579}
580
581static struct cifs_pending_open *
582smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
583				  struct smb2_lease_break *rsp)
584{
585	__u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
586	int ack_req = le32_to_cpu(rsp->Flags &
587				  SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
588	struct cifs_pending_open *open;
589	struct cifs_pending_open *found = NULL;
590
591	list_for_each_entry(open, &tcon->pending_opens, olist) {
592		if (memcmp(open->lease_key, rsp->LeaseKey,
593			   SMB2_LEASE_KEY_SIZE))
594			continue;
595
596		if (!found && ack_req) {
597			found = open;
598		}
599
600		cifs_dbg(FYI, "found in the pending open list\n");
601		cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
602			 lease_state);
603
604		open->oplock = lease_state;
605	}
606
607	return found;
608}
609
610static bool
611smb2_is_valid_lease_break(char *buffer, struct TCP_Server_Info *server)
612{
613	struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
614	struct TCP_Server_Info *pserver;
615	struct cifs_ses *ses;
616	struct cifs_tcon *tcon;
617	struct cifs_pending_open *open;
618
619	/* Trace receipt of lease break request from server */
620	trace_smb3_lease_break_enter(le32_to_cpu(rsp->CurrentLeaseState),
621		le32_to_cpu(rsp->Flags),
622		le16_to_cpu(rsp->Epoch),
623		le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
624		le64_to_cpu(rsp->hdr.SessionId),
625		*((u64 *)rsp->LeaseKey),
626		*((u64 *)&rsp->LeaseKey[8]));
627
628	cifs_dbg(FYI, "Checking for lease break\n");
629
630	/* If server is a channel, select the primary channel */
631	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
632
633	/* look up tcon based on tid & uid */
634	spin_lock(&cifs_tcp_ses_lock);
635	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
636		if (cifs_ses_exiting(ses))
637			continue;
638		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
639			spin_lock(&tcon->open_file_lock);
640			cifs_stats_inc(
641				       &tcon->stats.cifs_stats.num_oplock_brks);
642			if (smb2_tcon_has_lease(tcon, rsp)) {
643				spin_unlock(&tcon->open_file_lock);
644				spin_unlock(&cifs_tcp_ses_lock);
645				return true;
646			}
647			open = smb2_tcon_find_pending_open_lease(tcon,
648								 rsp);
649			if (open) {
650				__u8 lease_key[SMB2_LEASE_KEY_SIZE];
651				struct tcon_link *tlink;
652
653				tlink = cifs_get_tlink(open->tlink);
654				memcpy(lease_key, open->lease_key,
655				       SMB2_LEASE_KEY_SIZE);
656				spin_unlock(&tcon->open_file_lock);
657				spin_unlock(&cifs_tcp_ses_lock);
658				smb2_queue_pending_open_break(tlink,
659							      lease_key,
660							      rsp->NewLeaseState);
661				return true;
662			}
663			spin_unlock(&tcon->open_file_lock);
664
665			if (cached_dir_lease_break(tcon, rsp->LeaseKey)) {
666				spin_unlock(&cifs_tcp_ses_lock);
667				return true;
668			}
669		}
670	}
671	spin_unlock(&cifs_tcp_ses_lock);
672	cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
673	trace_smb3_lease_not_found(le32_to_cpu(rsp->CurrentLeaseState),
674					   le32_to_cpu(rsp->Flags),
675					   le16_to_cpu(rsp->Epoch),
676					   le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
677					   le64_to_cpu(rsp->hdr.SessionId),
678					   *((u64 *)rsp->LeaseKey),
679					   *((u64 *)&rsp->LeaseKey[8]));
680
681	return false;
682}
683
684bool
685smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
686{
687	struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
688	struct TCP_Server_Info *pserver;
689	struct cifs_ses *ses;
690	struct cifs_tcon *tcon;
691	struct cifsInodeInfo *cinode;
692	struct cifsFileInfo *cfile;
693
694	cifs_dbg(FYI, "Checking for oplock break\n");
695
696	if (rsp->hdr.Command != SMB2_OPLOCK_BREAK)
697		return false;
698
699	if (rsp->StructureSize !=
700				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
701		if (le16_to_cpu(rsp->StructureSize) == 44)
702			return smb2_is_valid_lease_break(buffer, server);
703		else
704			return false;
705	}
706
707	cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
708
709	/* If server is a channel, select the primary channel */
710	pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
711
712	/* look up tcon based on tid & uid */
713	spin_lock(&cifs_tcp_ses_lock);
714	list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
715		if (cifs_ses_exiting(ses))
716			continue;
717		list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
718
719			spin_lock(&tcon->open_file_lock);
720			list_for_each_entry(cfile, &tcon->openFileList, tlist) {
721				if (rsp->PersistentFid !=
722				    cfile->fid.persistent_fid ||
723				    rsp->VolatileFid !=
724				    cfile->fid.volatile_fid)
725					continue;
726
727				cifs_dbg(FYI, "file id match, oplock break\n");
728				cifs_stats_inc(
729				    &tcon->stats.cifs_stats.num_oplock_brks);
730				cinode = CIFS_I(d_inode(cfile->dentry));
731				spin_lock(&cfile->file_info_lock);
732				if (!CIFS_CACHE_WRITE(cinode) &&
733				    rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
734					cfile->oplock_break_cancelled = true;
735				else
736					cfile->oplock_break_cancelled = false;
737
738				set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
739					&cinode->flags);
740
741				cfile->oplock_epoch = 0;
742				cfile->oplock_level = rsp->OplockLevel;
743
744				spin_unlock(&cfile->file_info_lock);
745
746				cifs_queue_oplock_break(cfile);
747
748				spin_unlock(&tcon->open_file_lock);
749				spin_unlock(&cifs_tcp_ses_lock);
750				return true;
751			}
752			spin_unlock(&tcon->open_file_lock);
753		}
754	}
755	spin_unlock(&cifs_tcp_ses_lock);
756	cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
757	trace_smb3_oplock_not_found(0 /* no xid */, rsp->PersistentFid,
758				  le32_to_cpu(rsp->hdr.Id.SyncId.TreeId),
759				  le64_to_cpu(rsp->hdr.SessionId));
760
761	return true;
762}
763
764void
765smb2_cancelled_close_fid(struct work_struct *work)
766{
767	struct close_cancelled_open *cancelled = container_of(work,
768					struct close_cancelled_open, work);
769	struct cifs_tcon *tcon = cancelled->tcon;
770	int rc;
771
772	if (cancelled->mid)
773		cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
774			      cancelled->mid);
775	else
776		cifs_tcon_dbg(VFS, "Close interrupted close\n");
777
778	rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
779			cancelled->fid.volatile_fid);
780	if (rc)
781		cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
782
783	cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close_fid);
784	kfree(cancelled);
785}
786
787/*
788 * Caller should already has an extra reference to @tcon
789 * This function is used to queue work to close a handle to prevent leaks
790 * on the server.
791 * We handle two cases. If an open was interrupted after we sent the
792 * SMB2_CREATE to the server but before we processed the reply, and second
793 * if a close was interrupted before we sent the SMB2_CLOSE to the server.
794 */
795static int
796__smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
797			    __u64 persistent_fid, __u64 volatile_fid)
798{
799	struct close_cancelled_open *cancelled;
800
801	cancelled = kzalloc(sizeof(*cancelled), GFP_KERNEL);
802	if (!cancelled)
803		return -ENOMEM;
804
805	cancelled->fid.persistent_fid = persistent_fid;
806	cancelled->fid.volatile_fid = volatile_fid;
807	cancelled->tcon = tcon;
808	cancelled->cmd = cmd;
809	cancelled->mid = mid;
810	INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
811	WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
812
813	return 0;
814}
815
816int
817smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
818			    __u64 volatile_fid)
819{
820	int rc;
821
822	cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
823	spin_lock(&tcon->tc_lock);
824	if (tcon->tc_count <= 0) {
825		struct TCP_Server_Info *server = NULL;
826
827		trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
828				    netfs_trace_tcon_ref_see_cancelled_close);
829		WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
830		spin_unlock(&tcon->tc_lock);
831
832		if (tcon->ses) {
833			server = tcon->ses->server;
834			cifs_server_dbg(FYI,
835					"tid=0x%x: tcon is closing, skipping async close retry of fid %llu %llu\n",
836					tcon->tid, persistent_fid, volatile_fid);
837		}
838
839		return 0;
840	}
841	tcon->tc_count++;
842	trace_smb3_tcon_ref(tcon->debug_id, tcon->tc_count,
843			    netfs_trace_tcon_ref_get_cancelled_close);
844	spin_unlock(&tcon->tc_lock);
845
846	rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
847					 persistent_fid, volatile_fid);
848	if (rc)
849		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_close);
850
851	return rc;
852}
853
854int
855smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
856{
857	struct smb2_hdr *hdr = mid->resp_buf;
858	struct smb2_create_rsp *rsp = mid->resp_buf;
859	struct cifs_tcon *tcon;
860	int rc;
861
862	if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || hdr->Command != SMB2_CREATE ||
863	    hdr->Status != STATUS_SUCCESS)
864		return 0;
865
866	tcon = smb2_find_smb_tcon(server, le64_to_cpu(hdr->SessionId),
867				  le32_to_cpu(hdr->Id.SyncId.TreeId));
868	if (!tcon)
869		return -ENOENT;
870
871	rc = __smb2_handle_cancelled_cmd(tcon,
872					 le16_to_cpu(hdr->Command),
873					 le64_to_cpu(hdr->MessageId),
874					 rsp->PersistentFileId,
875					 rsp->VolatileFileId);
876	if (rc)
877		cifs_put_tcon(tcon, netfs_trace_tcon_ref_put_cancelled_mid);
878
879	return rc;
880}
881
882/**
883 * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
884 *
885 * Assumes @iov does not contain the rfc1002 length and iov[0] has the
886 * SMB2 header.
887 *
888 * @ses:	server session structure
889 * @server:	pointer to server info
890 * @iov:	array containing the SMB request we will send to the server
891 * @nvec:	number of array entries for the iov
892 */
893void
894smb311_update_preauth_hash(struct cifs_ses *ses, struct TCP_Server_Info *server,
895			   struct kvec *iov, int nvec)
896{
897	int i;
898	struct smb2_hdr *hdr;
899	struct sha512_ctx sha_ctx;
900
901	hdr = (struct smb2_hdr *)iov[0].iov_base;
902	/* neg prot are always taken */
903	if (hdr->Command == SMB2_NEGOTIATE)
904		goto ok;
905
906	/*
907	 * If we process a command which wasn't a negprot it means the
908	 * neg prot was already done, so the server dialect was set
909	 * and we can test it. Preauth requires 3.1.1 for now.
910	 */
911	if (server->dialect != SMB311_PROT_ID)
912		return;
913
914	if (hdr->Command != SMB2_SESSION_SETUP)
915		return;
916
917	/* skip last sess setup response */
918	if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
919	    && (hdr->Status == NT_STATUS_OK
920		|| (hdr->Status !=
921		    cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
922		return;
923
924ok:
925	sha512_init(&sha_ctx);
926	sha512_update(&sha_ctx, ses->preauth_sha_hash, SMB2_PREAUTH_HASH_SIZE);
927	for (i = 0; i < nvec; i++)
928		sha512_update(&sha_ctx, iov[i].iov_base, iov[i].iov_len);
929	sha512_final(&sha_ctx, ses->preauth_sha_hash);
930}