summaryrefslogtreecommitdiffstats
path: root/fs/cifs/smb2pdu.c
blob: 62b3f17d061363657374bacfab7dc7abff21a5a6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
/*
 *   fs/cifs/smb2pdu.c
 *
 *   Copyright (C) International Business Machines  Corp., 2009, 2011
 *                 Etersoft, 2012
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *              Pavel Shilovsky (pshilovsky@samba.org) 2012
 *
 *   Contains the routines for constructing the SMB2 PDUs themselves
 *
 *   This library is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published
 *   by the Free Software Foundation; either version 2.1 of the License, or
 *   (at your option) any later version.
 *
 *   This library is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

 /* SMB2 PDU handling routines here - except for leftovers (eg session setup) */
 /* Note that there are handle based routines which must be		      */
 /* treated slightly differently for reconnection purposes since we never     */
 /* want to reuse a stale file handle and only the caller knows the file info */

#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/vfs.h>
#include <linux/uaccess.h>
#include <linux/xattr.h>
#include "smb2pdu.h"
#include "cifsglob.h"
#include "cifsacl.h"
#include "cifsproto.h"
#include "smb2proto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "ntlmssp.h"
#include "smb2status.h"

/*
 *  The following table defines the expected "StructureSize" of SMB2 requests
 *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS requests.
 *
 *  Note that commands are defined in smb2pdu.h in le16 but the array below is
 *  indexed by command in host byte order.
 */
static const int smb2_req_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
	/* SMB2_NEGOTIATE */ 36,
	/* SMB2_SESSION_SETUP */ 25,
	/* SMB2_LOGOFF */ 4,
	/* SMB2_TREE_CONNECT */	9,
	/* SMB2_TREE_DISCONNECT */ 4,
	/* SMB2_CREATE */ 57,
	/* SMB2_CLOSE */ 24,
	/* SMB2_FLUSH */ 24,
	/* SMB2_READ */	49,
	/* SMB2_WRITE */ 49,
	/* SMB2_LOCK */	48,
	/* SMB2_IOCTL */ 57,
	/* SMB2_CANCEL */ 4,
	/* SMB2_ECHO */ 4,
	/* SMB2_QUERY_DIRECTORY */ 33,
	/* SMB2_CHANGE_NOTIFY */ 32,
	/* SMB2_QUERY_INFO */ 41,
	/* SMB2_SET_INFO */ 33,
	/* SMB2_OPLOCK_BREAK */ 24 /* BB this is 36 for LEASE_BREAK variant */
};


static void
smb2_hdr_assemble(struct smb2_hdr *hdr, __le16 smb2_cmd /* command */ ,
		  const struct cifs_tcon *tcon)
{
	struct smb2_pdu *pdu = (struct smb2_pdu *)hdr;
	char *temp = (char *)hdr;
	/* lookup word count ie StructureSize from table */
	__u16 parmsize = smb2_req_struct_sizes[le16_to_cpu(smb2_cmd)];

	/*
	 * smaller than SMALL_BUFFER_SIZE but bigger than fixed area of
	 * largest operations (Create)
	 */
	memset(temp, 0, 256);

	/* Note this is only network field converted to big endian */
	hdr->smb2_buf_length = cpu_to_be32(parmsize + sizeof(struct smb2_hdr)
			- 4 /*  RFC 1001 length field itself not counted */);

	hdr->ProtocolId[0] = 0xFE;
	hdr->ProtocolId[1] = 'S';
	hdr->ProtocolId[2] = 'M';
	hdr->ProtocolId[3] = 'B';
	hdr->StructureSize = cpu_to_le16(64);
	hdr->Command = smb2_cmd;
	hdr->CreditRequest = cpu_to_le16(2); /* BB make this dynamic */
	hdr->ProcessId = cpu_to_le32((__u16)current->tgid);

	if (!tcon)
		goto out;

	hdr->TreeId = tcon->tid;
	/* Uid is not converted */
	if (tcon->ses)
		hdr->SessionId = tcon->ses->Suid;
	/* BB check following DFS flags BB */
	/* BB do we have to add check for SHI1005_FLAGS_DFS_ROOT too? */
	if (tcon->share_flags & SHI1005_FLAGS_DFS)
		hdr->Flags |= SMB2_FLAGS_DFS_OPERATIONS;
	/* BB how does SMB2 do case sensitive? */
	/* if (tcon->nocase)
		hdr->Flags |= SMBFLG_CASELESS; */
	/* if (tcon->ses && tcon->ses->server &&
	    (tcon->ses->server->sec_mode & SECMODE_SIGN_REQUIRED))
		hdr->Flags |= SMB2_FLAGS_SIGNED; */
out:
	pdu->StructureSize2 = cpu_to_le16(parmsize);
	return;
}

static int
smb2_reconnect(__le16 smb2_command, struct cifs_tcon *tcon)
{
	int rc = 0;
	struct nls_table *nls_codepage;
	struct cifs_ses *ses;
	struct TCP_Server_Info *server;

	/*
	 * SMB2s NegProt, SessSetup, Logoff do not have tcon yet so
	 * check for tcp and smb session status done differently
	 * for those three - in the calling routine.
	 */
	if (tcon == NULL)
		return rc;

	if (smb2_command == SMB2_TREE_CONNECT)
		return rc;

	if (tcon->tidStatus == CifsExiting) {
		/*
		 * only tree disconnect, open, and write,
		 * (and ulogoff which does not have tcon)
		 * are allowed as we start force umount.
		 */
		if ((smb2_command != SMB2_WRITE) &&
		   (smb2_command != SMB2_CREATE) &&
		   (smb2_command != SMB2_TREE_DISCONNECT)) {
			cFYI(1, "can not send cmd %d while umounting",
				smb2_command);
			return -ENODEV;
		}
	}
	if ((!tcon->ses) || (tcon->ses->status == CifsExiting) ||
	    (!tcon->ses->server))
		return -EIO;

	ses = tcon->ses;
	server = ses->server;

	/*
	 * Give demultiplex thread up to 10 seconds to reconnect, should be
	 * greater than cifs socket timeout which is 7 seconds
	 */
	while (server->tcpStatus == CifsNeedReconnect) {
		/*
		 * Return to caller for TREE_DISCONNECT and LOGOFF and CLOSE
		 * here since they are implicitly done when session drops.
		 */
		switch (smb2_command) {
		/*
		 * BB Should we keep oplock break and add flush to exceptions?
		 */
		case SMB2_TREE_DISCONNECT:
		case SMB2_CANCEL:
		case SMB2_CLOSE:
		case SMB2_OPLOCK_BREAK:
			return -EAGAIN;
		}

		wait_event_interruptible_timeout(server->response_q,
			(server->tcpStatus != CifsNeedReconnect), 10 * HZ);

		/* are we still trying to reconnect? */
		if (server->tcpStatus != CifsNeedReconnect)
			break;

		/*
		 * on "soft" mounts we wait once. Hard mounts keep
		 * retrying until process is killed or server comes
		 * back on-line
		 */
		if (!tcon->retry) {
			cFYI(1, "gave up waiting on reconnect in smb_init");
			return -EHOSTDOWN;
		}
	}

	if (!tcon->ses->need_reconnect && !tcon->need_reconnect)
		return rc;

	nls_codepage = load_nls_default();

	/*
	 * need to prevent multiple threads trying to simultaneously reconnect
	 * the same SMB session
	 */
	mutex_lock(&tcon->ses->session_mutex);
	rc = cifs_negotiate_protocol(0, tcon->ses);
	if (!rc && tcon->ses->need_reconnect)
		rc = cifs_setup_session(0, tcon->ses, nls_codepage);

	if (rc || !tcon->need_reconnect) {
		mutex_unlock(&tcon->ses->session_mutex);
		goto out;
	}

	cifs_mark_open_files_invalid(tcon);
	rc = SMB2_tcon(0, tcon->ses, tcon->treeName, tcon, nls_codepage);
	mutex_unlock(&tcon->ses->session_mutex);
	cFYI(1, "reconnect tcon rc = %d", rc);
	if (rc)
		goto out;
	atomic_inc(&tconInfoReconnectCount);
	/*
	 * BB FIXME add code to check if wsize needs update due to negotiated
	 * smb buffer size shrinking.
	 */
out:
	/*
	 * Check if handle based operation so we know whether we can continue
	 * or not without returning to caller to reset file handle.
	 */
	/*
	 * BB Is flush done by server on drop of tcp session? Should we special
	 * case it and skip above?
	 */
	switch (smb2_command) {
	case SMB2_FLUSH:
	case SMB2_READ:
	case SMB2_WRITE:
	case SMB2_LOCK:
	case SMB2_IOCTL:
	case SMB2_QUERY_DIRECTORY:
	case SMB2_CHANGE_NOTIFY:
	case SMB2_QUERY_INFO:
	case SMB2_SET_INFO:
		return -EAGAIN;
	}
	unload_nls(nls_codepage);
	return rc;
}

/*
 * Allocate and return pointer to an SMB request hdr, and set basic
 * SMB information in the SMB header. If the return code is zero, this
 * function must have filled in request_buf pointer.
 */
static int
small_smb2_init(__le16 smb2_command, struct cifs_tcon *tcon,
		void **request_buf)
{
	int rc = 0;

	rc = smb2_reconnect(smb2_command, tcon);
	if (rc)
		return rc;

	/* BB eventually switch this to SMB2 specific small buf size */
	*request_buf = cifs_small_buf_get();
	if (*request_buf == NULL) {
		/* BB should we add a retry in here if not a writepage? */
		return -ENOMEM;
	}

	smb2_hdr_assemble((struct smb2_hdr *) *request_buf, smb2_command, tcon);

	if (tcon != NULL) {
#ifdef CONFIG_CIFS_STATS2
		uint16_t com_code = le16_to_cpu(smb2_command);
		cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_sent[com_code]);
#endif
		cifs_stats_inc(&tcon->num_smbs_sent);
	}

	return rc;
}

static void
free_rsp_buf(int resp_buftype, void *rsp)
{
	if (resp_buftype == CIFS_SMALL_BUFFER)
		cifs_small_buf_release(rsp);
	else if (resp_buftype == CIFS_LARGE_BUFFER)
		cifs_buf_release(rsp);
}

#define SMB2_NUM_PROT 1

#define SMB2_PROT   0
#define SMB21_PROT  1
#define BAD_PROT 0xFFFF

#define SMB2_PROT_ID  0x0202
#define SMB21_PROT_ID 0x0210
#define BAD_PROT_ID   0xFFFF

static struct {
	int index;
	__le16 name;
} smb2protocols[] = {
	{SMB2_PROT,  cpu_to_le16(SMB2_PROT_ID)},
	{SMB21_PROT, cpu_to_le16(SMB21_PROT_ID)},
	{BAD_PROT,   cpu_to_le16(BAD_PROT_ID)}
};

/*
 *
 *	SMB2 Worker functions follow:
 *
 *	The general structure of the worker functions is:
 *	1) Call smb2_init (assembles SMB2 header)
 *	2) Initialize SMB2 command specific fields in fixed length area of SMB
 *	3) Call smb_sendrcv2 (sends request on socket and waits for response)
 *	4) Decode SMB2 command specific fields in the fixed length area
 *	5) Decode variable length data area (if any for this SMB2 command type)
 *	6) Call free smb buffer
 *	7) return
 *
 */

int
SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
{
	struct smb2_negotiate_req *req;
	struct smb2_negotiate_rsp *rsp;
	struct kvec iov[1];
	int rc = 0;
	int resp_buftype;
	struct TCP_Server_Info *server;
	unsigned int sec_flags;
	u16 i;
	u16 temp = 0;
	int blob_offset, blob_length;
	char *security_blob;
	int flags = CIFS_NEG_OP;

	cFYI(1, "Negotiate protocol");

	if (ses->server)
		server = ses->server;
	else {
		rc = -EIO;
		return rc;
	}

	rc = small_smb2_init(SMB2_NEGOTIATE, NULL, (void **) &req);
	if (rc)
		return rc;

	/* if any of auth flags (ie not sign or seal) are overriden use them */
	if (ses->overrideSecFlg & (~(CIFSSEC_MUST_SIGN | CIFSSEC_MUST_SEAL)))
		sec_flags = ses->overrideSecFlg;  /* BB FIXME fix sign flags?*/
	else /* if override flags set only sign/seal OR them with global auth */
		sec_flags = global_secflags | ses->overrideSecFlg;

	cFYI(1, "sec_flags 0x%x", sec_flags);

	req->hdr.SessionId = 0;

	for (i = 0; i < SMB2_NUM_PROT; i++)
		req->Dialects[i] = smb2protocols[i].name;

	req->DialectCount = cpu_to_le16(i);
	inc_rfc1001_len(req, i * 2);

	/* only one of SMB2 signing flags may be set in SMB2 request */
	if ((sec_flags & CIFSSEC_MUST_SIGN) == CIFSSEC_MUST_SIGN)
		temp = SMB2_NEGOTIATE_SIGNING_REQUIRED;
	else if (sec_flags & CIFSSEC_MAY_SIGN) /* MAY_SIGN is a single flag */
		temp = SMB2_NEGOTIATE_SIGNING_ENABLED;

	req->SecurityMode = cpu_to_le16(temp);

	req->Capabilities = cpu_to_le32(SMB2_GLOBAL_CAP_DFS);

	iov[0].iov_base = (char *)req;
	/* 4 for rfc1002 length field */
	iov[0].iov_len = get_rfc1002_length(req) + 4;

	rc = SendReceive2(xid, ses, iov, 1, &resp_buftype, flags);

	rsp = (struct smb2_negotiate_rsp *)iov[0].iov_base;
	/*
	 * No tcon so can't do
	 * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
	 */
	if (rc != 0)
		goto neg_exit;

	if (rsp == NULL) {
		rc = -EIO;
		goto neg_exit;
	}

	cFYI(1, "mode 0x%x", rsp->SecurityMode);

	if (rsp->DialectRevision == smb2protocols[SMB21_PROT].name)
		cFYI(1, "negotiated smb2.1 dialect");
	else if (rsp->DialectRevision == smb2protocols[SMB2_PROT].name)
		cFYI(1, "negotiated smb2 dialect");
	else {
		cERROR(1, "Illegal dialect returned by server %d",
			   le16_to_cpu(rsp->DialectRevision));
		rc = -EIO;
		goto neg_exit;
	}
	server->dialect = le16_to_cpu(rsp->DialectRevision);

	server->maxBuf = le32_to_cpu(rsp->MaxTransactSize);
	server->max_read = le32_to_cpu(rsp->MaxReadSize);
	server->max_write = le32_to_cpu(rsp->MaxWriteSize);
	/* BB Do we need to validate the SecurityMode? */
	server->sec_mode = le16_to_cpu(rsp->SecurityMode);
	server->capabilities = le32_to_cpu(rsp->Capabilities);
	/* Internal types */
	server->capabilities |= SMB2_NT_FIND | SMB2_LARGE_FILES;

	security_blob = smb2_get_data_area_len(&blob_offset, &blob_length,
					       &rsp->hdr);
	if (blob_length == 0) {
		cERROR(1, "missing security blob on negprot");
		rc = -EIO;
		goto neg_exit;
	}
#ifdef CONFIG_SMB2_ASN1  /* BB REMOVEME when updated asn1.c ready */
	rc = decode_neg_token_init(security_blob, blob_length,
				   &server->sec_type);
	if (rc == 1)
		rc = 0;
	else if (rc == 0) {
		rc = -EIO;
		goto neg_exit;
	}
#endif

neg_exit:
	free_rsp_buf(resp_buftype, rsp);
	return rc;
}

int
SMB2_sess_setup(const unsigned int xid, struct cifs_ses *ses,
		const struct nls_table *nls_cp)
{
	struct smb2_sess_setup_req *req;
	struct smb2_sess_setup_rsp *rsp = NULL;
	struct kvec iov[2];
	int rc = 0;
	int resp_buftype;
	__le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
	struct TCP_Server_Info *server;
	unsigned int sec_flags;
	u8 temp = 0;
	u16 blob_length = 0;
	char *security_blob;
	char *ntlmssp_blob = NULL;
	bool use_spnego = false; /* else use raw ntlmssp */

	cFYI(1, "Session Setup");

	if (ses->server)
		server = ses->server;
	else {
		rc = -EIO;
		return rc;
	}

	/*
	 * If memory allocation is successful, caller of this function
	 * frees it.
	 */
	ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
	if (!ses->ntlmssp)
		return -ENOMEM;

	ses->server->secType = RawNTLMSSP;

ssetup_ntlmssp_authenticate:
	if (phase == NtLmChallenge)
		phase = NtLmAuthenticate; /* if ntlmssp, now final phase */

	rc = small_smb2_init(SMB2_SESSION_SETUP, NULL, (void **) &req);
	if (rc)
		return rc;

	/* if any of auth flags (ie not sign or seal) are overriden use them */
	if (ses->overrideSecFlg & (~(CIFSSEC_MUST_SIGN | CIFSSEC_MUST_SEAL)))
		sec_flags = ses->overrideSecFlg;  /* BB FIXME fix sign flags?*/
	else /* if override flags set only sign/seal OR them with global auth */
		sec_flags = global_secflags | ses->overrideSecFlg;

	cFYI(1, "sec_flags 0x%x", sec_flags);

	req->hdr.SessionId = 0; /* First session, not a reauthenticate */
	req->VcNumber = 0; /* MBZ */
	/* to enable echos and oplocks */
	req->hdr.CreditRequest = cpu_to_le16(3);

	/* only one of SMB2 signing flags may be set in SMB2 request */
	if ((sec_flags & CIFSSEC_MUST_SIGN) == CIFSSEC_MUST_SIGN)
		temp = SMB2_NEGOTIATE_SIGNING_REQUIRED;
	else if (ses->server->sec_mode & SMB2_NEGOTIATE_SIGNING_REQUIRED)
		temp = SMB2_NEGOTIATE_SIGNING_REQUIRED;
	else if (sec_flags & CIFSSEC_MAY_SIGN) /* MAY_SIGN is a single flag */
		temp = SMB2_NEGOTIATE_SIGNING_ENABLED;

	req->SecurityMode = temp;
	req->Capabilities = 0;
	req->Channel = 0; /* MBZ */

	iov[0].iov_base = (char *)req;
	/* 4 for rfc1002 length field and 1 for pad */
	iov[0].iov_len = get_rfc1002_length(req) + 4 - 1;
	if (phase == NtLmNegotiate) {
		ntlmssp_blob = kmalloc(sizeof(struct _NEGOTIATE_MESSAGE),
				       GFP_KERNEL);
		if (ntlmssp_blob == NULL) {
			rc = -ENOMEM;
			goto ssetup_exit;
		}
		build_ntlmssp_negotiate_blob(ntlmssp_blob, ses);
		if (use_spnego) {
			/* blob_length = build_spnego_ntlmssp_blob(
					&security_blob,
					sizeof(struct _NEGOTIATE_MESSAGE),
					ntlmssp_blob); */
			/* BB eventually need to add this */
			cERROR(1, "spnego not supported for SMB2 yet");
			rc = -EOPNOTSUPP;
			kfree(ntlmssp_blob);
			goto ssetup_exit;
		} else {
			blob_length = sizeof(struct _NEGOTIATE_MESSAGE);
			/* with raw NTLMSSP we don't encapsulate in SPNEGO */
			security_blob = ntlmssp_blob;
		}
	} else if (phase == NtLmAuthenticate) {
		req->hdr.SessionId = ses->Suid;
		ntlmssp_blob = kzalloc(sizeof(struct _NEGOTIATE_MESSAGE) + 500,
				       GFP_KERNEL);
		if (ntlmssp_blob == NULL) {
			cERROR(1, "failed to malloc ntlmssp blob");
			rc = -ENOMEM;
			goto ssetup_exit;
		}
		rc = build_ntlmssp_auth_blob(ntlmssp_blob, &blob_length, ses,
					     nls_cp);
		if (rc) {
			cFYI(1, "build_ntlmssp_auth_blob failed %d", rc);
			goto ssetup_exit; /* BB double check error handling */
		}
		if (use_spnego) {
			/* blob_length = build_spnego_ntlmssp_blob(
							&security_blob,
							blob_length,
							ntlmssp_blob); */
			cERROR(1, "spnego not supported for SMB2 yet");
			rc = -EOPNOTSUPP;
			kfree(ntlmssp_blob);
			goto ssetup_exit;
		} else {
			security_blob = ntlmssp_blob;
		}
	} else {
		cERROR(1, "illegal ntlmssp phase");
		rc = -EIO;
		goto ssetup_exit;
	}

	/* Testing shows that buffer offset must be at location of Buffer[0] */
	req->SecurityBufferOffset =
				cpu_to_le16(sizeof(struct smb2_sess_setup_req) -
					    1 /* pad */ - 4 /* rfc1001 len */);
	req->SecurityBufferLength = cpu_to_le16(blob_length);
	iov[1].iov_base = security_blob;
	iov[1].iov_len = blob_length;

	inc_rfc1001_len(req, blob_length - 1 /* pad */);

	/* BB add code to build os and lm fields */

	rc = SendReceive2(xid, ses, iov, 2, &resp_buftype, CIFS_LOG_ERROR);

	kfree(security_blob);
	rsp = (struct smb2_sess_setup_rsp *)iov[0].iov_base;
	if (rsp->hdr.Status == STATUS_MORE_PROCESSING_REQUIRED) {
		if (phase != NtLmNegotiate) {
			cERROR(1, "Unexpected more processing error");
			goto ssetup_exit;
		}
		if (offsetof(struct smb2_sess_setup_rsp, Buffer) - 4 !=
			le16_to_cpu(rsp->SecurityBufferOffset)) {
			cERROR(1, "Invalid security buffer offset %d",
				  le16_to_cpu(rsp->SecurityBufferOffset));
			rc = -EIO;
			goto ssetup_exit;
		}

		/* NTLMSSP Negotiate sent now processing challenge (response) */
		phase = NtLmChallenge; /* process ntlmssp challenge */
		rc = 0; /* MORE_PROCESSING is not an error here but expected */
		ses->Suid = rsp->hdr.SessionId;
		rc = decode_ntlmssp_challenge(rsp->Buffer,
				le16_to_cpu(rsp->SecurityBufferLength), ses);
	}

	/*
	 * BB eventually add code for SPNEGO decoding of NtlmChallenge blob,
	 * but at least the raw NTLMSSP case works.
	 */
	/*
	 * No tcon so can't do
	 * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
	 */
	if (rc != 0)
		goto ssetup_exit;

	if (rsp == NULL) {
		rc = -EIO;
		goto ssetup_exit;
	}

	ses->session_flags = le16_to_cpu(rsp->SessionFlags);
ssetup_exit:
	free_rsp_buf(resp_buftype, rsp);

	/* if ntlmssp, and negotiate succeeded, proceed to authenticate phase */
	if ((phase == NtLmChallenge) && (rc == 0))
		goto ssetup_ntlmssp_authenticate;
	return rc;
}

int
SMB2_logoff(const unsigned int xid, struct cifs_ses *ses)
{
	struct smb2_logoff_req *req; /* response is also trivial struct */
	int rc = 0;
	struct TCP_Server_Info *server;

	cFYI(1, "disconnect session %p", ses);

	if (ses && (ses->server))
		server = ses->server;
	else
		return -EIO;

	rc = small_smb2_init(SMB2_LOGOFF, NULL, (void **) &req);
	if (rc)
		return rc;

	 /* since no tcon, smb2_init can not do this, so do here */
	req->hdr.SessionId = ses->Suid;

	rc = SendReceiveNoRsp(xid, ses, (char *) &req->hdr, 0);
	/*
	 * No tcon so can't do
	 * cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_fail[SMB2...]);
	 */
	return rc;
}

static inline void cifs_stats_fail_inc(struct cifs_tcon *tcon, uint16_t code)
{
	cifs_stats_inc(&tcon->stats.smb2_stats.smb2_com_failed[code]);
}

#define MAX_SHARENAME_LENGTH (255 /* server */ + 80 /* share */ + 1 /* NULL */)

int
SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, const char *tree,
	  struct cifs_tcon *tcon, const struct nls_table *cp)
{
	struct smb2_tree_connect_req *req;
	struct smb2_tree_connect_rsp *rsp = NULL;
	struct kvec iov[2];
	int rc = 0;
	int resp_buftype;
	int unc_path_len;
	struct TCP_Server_Info *server;
	__le16 *unc_path = NULL;

	cFYI(1, "TCON");

	if ((ses->server) && tree)
		server = ses->server;
	else
		return -EIO;

	if (tcon && tcon->bad_network_name)
		return -ENOENT;

	unc_path = kmalloc(MAX_SHARENAME_LENGTH * 2, GFP_KERNEL);
	if (unc_path == NULL)
		return -ENOMEM;

	unc_path_len = cifs_strtoUTF16(unc_path, tree, strlen(tree), cp) + 1;
	unc_path_len *= 2;
	if (unc_path_len < 2) {
		kfree(unc_path);
		return -EINVAL;
	}

	rc = small_smb2_init(SMB2_TREE_CONNECT, tcon, (void **) &req);
	if (rc) {
		kfree(unc_path);
		return rc;
	}

	if (tcon == NULL) {
		/* since no tcon, smb2_init can not do this, so do here */
		req->hdr.SessionId = ses->Suid;
		/* if (ses->server->sec_mode & SECMODE_SIGN_REQUIRED)
			req->hdr.Flags |= SMB2_FLAGS_SIGNED; */
	}

	iov[0].iov_base = (char *)req;
	/* 4 for rfc1002 length field and 1 for pad */
	iov[0].iov_len = get_rfc1002_length(req) + 4 - 1;

	/* Testing shows that buffer offset must be at location of Buffer[0] */
	req->PathOffset = cpu_to_le16(sizeof(struct smb2_tree_connect_req)
			- 1 /* pad */ - 4 /* do not count rfc1001 len field */);
	req->PathLength = cpu_to_le16(unc_path_len - 2);
	iov[1].iov_base = unc_path;
	iov[1].iov_len = unc_path_len;

	inc_rfc1001_len(req, unc_path_len - 1 /* pad */);

	rc = SendReceive2(xid, ses, iov, 2, &resp_buftype, 0);
	rsp = (struct smb2_tree_connect_rsp *)iov[0].iov_base;

	if (rc != 0) {
		if (tcon) {
			cifs_stats_fail_inc(tcon, SMB2_TREE_CONNECT_HE);
			tcon->need_reconnect = true;
		}
		goto tcon_error_exit;
	}

	if (rsp == NULL) {
		rc = -EIO;
		goto tcon_exit;
	}

	if (tcon == NULL) {
		ses->ipc_tid = rsp->hdr.TreeId;
		goto tcon_exit;
	}

	if (rsp->ShareType & SMB2_SHARE_TYPE_DISK)
		cFYI(1, "connection to disk share");
	else if (rsp->ShareType & SMB2_SHARE_TYPE_PIPE) {
		tcon->ipc = true;
		cFYI(1, "connection to pipe share");
	} else if (rsp->ShareType & SMB2_SHARE_TYPE_PRINT) {
		tcon->print = true;
		cFYI(1, "connection to printer");
	} else {
		cERROR(1, "unknown share type %d", rsp->ShareType);
		rc = -EOPNOTSUPP;
		goto tcon_error_exit;
	}

	tcon->share_flags = le32_to_cpu(rsp->ShareFlags);
	tcon->maximal_access = le32_to_cpu(rsp->MaximalAccess);
	tcon->tidStatus = CifsGood;
	tcon->need_reconnect = false;
	tcon->tid = rsp->hdr.TreeId;
	strncpy(tcon->treeName, tree, MAX_TREE_SIZE);

	if ((rsp->Capabilities & SMB2_SHARE_CAP_DFS) &&
	    ((tcon->share_flags & SHI1005_FLAGS_DFS) == 0))
		cERROR(1, "DFS capability contradicts DFS flag");

tcon_exit:
	free_rsp_buf(resp_buftype, rsp);
	kfree(unc_path);
	return rc;

tcon_error_exit:
	if (rsp->hdr.Status == STATUS_BAD_NETWORK_NAME) {
		cERROR(1, "BAD_NETWORK_NAME: %s", tree);
		tcon->bad_network_name = true;
	}
	goto tcon_exit;
}

int
SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon)
{
	struct smb2_tree_disconnect_req *req; /* response is trivial */
	int rc = 0;
	struct TCP_Server_Info *server;
	struct cifs_ses *ses = tcon->ses;

	cFYI(1, "Tree Disconnect");

	if (ses && (ses->server))
		server = ses->server;
	else
		return -EIO;

	if ((tcon->need_reconnect) || (tcon->ses->need_reconnect))
		return 0;

	rc = small_smb2_init(SMB2_TREE_DISCONNECT, tcon, (void **) &req);
	if (rc)
		return rc;

	rc = SendReceiveNoRsp(xid, ses, (char *)&req->hdr, 0);
	if (rc)
		cifs_stats_fail_inc(tcon, SMB2_TREE_DISCONNECT_HE);

	return rc;
}

int
SMB2_open(const unsigned int xid, struct cifs_tcon *tcon, __le16 *path,
	  u64 *persistent_fid, u64 *volatile_fid, __u32 desired_access,
	  __u32 create_disposition, __u32 file_attributes, __u32 create_options)
{
	struct smb2_create_req *req;
	struct smb2_create_rsp *rsp;
	struct TCP_Server_Info *server;
	struct cifs_ses *ses = tcon->ses;
	struct kvec iov[2];
	int resp_buftype;
	int uni_path_len;
	int rc = 0;
	int num_iovecs = 2;

	cFYI(1, "create/open");

	if (ses && (ses->server))
		server = ses->server;
	else
		return -EIO;

	rc = small_smb2_init(SMB2_CREATE, tcon, (void **) &req);
	if (rc)
		return rc;

	if (enable_oplocks)
		req->RequestedOplockLevel = SMB2_OPLOCK_LEVEL_BATCH;
	else
		req->RequestedOplockLevel = SMB2_OPLOCK_LEVEL_NONE;
	req->ImpersonationLevel = IL_IMPERSONATION;
	req->DesiredAccess = cpu_to_le32(desired_access);
	/* File attributes ignored on open (used in create though) */
	req->FileAttributes = cpu_to_le32(file_attributes);
	req->ShareAccess = FILE_SHARE_ALL_LE;
	req->CreateDisposition = cpu_to_le32(create_disposition);
	req->CreateOptions = cpu_to_le32(create_options);
	uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2;
	req->NameOffset = cpu_to_le16(sizeof(struct smb2_create_req)
			- 1 /* pad */ - 4 /* do not count rfc1001 len field */);

	iov[0].iov_base = (char *)req;
	/* 4 for rfc1002 length field */
	iov[0].iov_len = get_rfc1002_length(req) + 4;

	/* MUST set path len (NameLength) to 0 opening root of share */
	if (uni_path_len >= 4) {
		req->NameLength = cpu_to_le16(uni_path_len - 2);
		/* -1 since last byte is buf[0] which is sent below (path) */
		iov[0].iov_len--;
		iov[1].iov_len = uni_path_len;
		iov[1].iov_base = path;
		/*
		 * -1 since last byte is buf[0] which was counted in
		 * smb2_buf_len.
		 */
		inc_rfc1001_len(req, uni_path_len - 1);
	} else {
		num_iovecs = 1;
		req->NameLength = 0;
	}

	rc = SendReceive2(xid, ses, iov, num_iovecs, &resp_buftype, 0);
	rsp = (struct smb2_create_rsp *)iov[0].iov_base;

	if (rc != 0) {
		cifs_stats_fail_inc(tcon, SMB2_CREATE_HE);
		goto creat_exit;
	}

	if (rsp == NULL) {
		rc = -EIO;
		goto creat_exit;
	}
	*persistent_fid = rsp->PersistentFileId;
	*volatile_fid = rsp->VolatileFileId;
creat_exit:
	free_rsp_buf(resp_buftype, rsp);
	return rc;
}

int
SMB2_close(const unsigned int xid, struct cifs_tcon *tcon,
	   u64 persistent_fid, u64 volatile_fid)
{
	struct smb2_close_req *req;
	struct smb2_close_rsp *rsp;
	struct TCP_Server_Info *server;
	struct cifs_ses *ses = tcon->ses;
	struct kvec iov[1];
	int resp_buftype;
	int rc = 0;

	cFYI(1, "Close");

	if (ses && (ses->server))
		server = ses->server;
	else
		return -EIO;

	rc = small_smb2_init(SMB2_CLOSE, tcon, (void **) &req);
	if (rc)
		return rc;

	req->PersistentFileId = persistent_fid;
	req->VolatileFileId = volatile_fid;

	iov[0].iov_base = (char *)req;
	/* 4 for rfc1002 length field */
	iov[0].iov_len = get_rfc1002_length(req) + 4;

	rc = SendReceive2(xid, ses, iov, 1, &resp_buftype, 0);
	rsp = (struct smb2_close_rsp *)iov[0].iov_base;

	if (rc != 0) {
		if (tcon)
			cifs_stats_fail_inc(tcon, SMB2_CLOSE_HE);
		goto close_exit;
	}

	if (rsp == NULL) {
		rc = -EIO;
		goto close_exit;
	}

	/* BB FIXME - decode close response, update inode for caching */

close_exit:
	free_rsp_buf(resp_buftype, rsp);
	return rc;
}

static int
validate_buf(unsigned int offset, unsigned int buffer_length,
	     struct smb2_hdr *hdr, unsigned int min_buf_size)

{
	unsigned int smb_len = be32_to_cpu(hdr->smb2_buf_length);
	char *end_of_smb = smb_len + 4 /* RFC1001 length field */ + (char *)hdr;
	char *begin_of_buf = 4 /* RFC1001 len field */ + offset + (char *)hdr;
	char *end_of_buf = begin_of_buf + buffer_length;


	if (buffer_length < min_buf_size) {
		cERROR(1, "buffer length %d smaller than minimum size %d",
			   buffer_length, min_buf_size);
		return -EINVAL;
	}

	/* check if beyond RFC1001 maximum length */
	if ((smb_len > 0x7FFFFF) || (buffer_length > 0x7FFFFF)) {
		cERROR(1, "buffer length %d or smb length %d too large",
			   buffer_length, smb_len);
		return -EINVAL;
	}

	if ((begin_of_buf > end_of_smb) || (end_of_buf > end_of_smb)) {
		cERROR(1, "illegal server response, bad offset to data");
		return -EINVAL;
	}

	return 0;
}

/*
 * If SMB buffer fields are valid, copy into temporary buffer to hold result.
 * Caller must free buffer.
 */
static int
validate_and_copy_buf(unsigned int offset, unsigned int buffer_length,
		      struct smb2_hdr *hdr, unsigned int minbufsize,
		      char *data)

{
	char *begin_of_buf = 4 /* RFC1001 len field */ + offset + (char *)hdr;
	int rc;

	if (!data)
		return -EINVAL;

	rc = validate_buf(offset, buffer_length, hdr, minbufsize);
	if (rc)
		return rc;

	memcpy(data, begin_of_buf, buffer_length);

	return 0;
}

int
SMB2_query_info(const unsigned int xid, struct cifs_tcon *tcon,
		u64 persistent_fid, u64 volatile_fid,
		struct smb2_file_all_info *data)
{
	struct smb2_query_info_req *req;
	struct smb2_query_info_rsp *rsp = NULL;
	struct kvec iov[2];
	int rc = 0;
	int resp_buftype;
	struct TCP_Server_Info *server;
	struct cifs_ses *ses = tcon->ses;

	cFYI(1, "Query Info");

	if (ses && (ses->server))
		server = ses->server;
	else
		return -EIO;

	rc = small_smb2_init(SMB2_QUERY_INFO, tcon, (void **) &req);
	if (rc)
		return rc;

	req->InfoType = SMB2_O_INFO_FILE;
	req->FileInfoClass = FILE_ALL_INFORMATION;
	req->PersistentFileId = persistent_fid;
	req->VolatileFileId = volatile_fid;
	/* 4 for rfc1002 length field and 1 for Buffer */
	req->InputBufferOffset =
		cpu_to_le16(sizeof(struct smb2_query_info_req) - 1 - 4);
	req->OutputBufferLength =
		cpu_to_le32(sizeof(struct smb2_file_all_info) + MAX_NAME * 2);

	iov[0].iov_base = (char *)req;
	/* 4 for rfc1002 length field */
	iov[0].iov_len = get_rfc1002_length(req) + 4;

	rc = SendReceive2(xid, ses, iov, 1, &resp_buftype, 0);
	if (rc) {
		cifs_stats_fail_inc(tcon, SMB2_QUERY_INFO_HE);
		goto qinf_exit;
	}

	rsp = (struct smb2_query_info_rsp *)iov[0].iov_base;

	rc = validate_and_copy_buf(le16_to_cpu(rsp->OutputBufferOffset),
				   le32_to_cpu(rsp->OutputBufferLength),
				   &rsp->hdr, sizeof(struct smb2_file_all_info),
				   (char *)data);

qinf_exit:
	free_rsp_buf(resp_buftype, rsp);
	return rc;
}

/*
 * This is a no-op for now. We're not really interested in the reply, but
 * rather in the fact that the server sent one and that server->lstrp
 * gets updated.
 *
 * FIXME: maybe we should consider checking that the reply matches request?
 */
static void
smb2_echo_callback(struct mid_q_entry *mid)
{
	struct TCP_Server_Info *server = mid->callback_data;
	struct smb2_echo_rsp *smb2 = (struct smb2_echo_rsp *)mid->resp_buf;
	unsigned int credits_received = 1;

	if (mid->mid_state == MID_RESPONSE_RECEIVED)
		credits_received = le16_to_cpu(smb2->hdr.CreditRequest);

	DeleteMidQEntry(mid);
	add_credits(server, credits_received, CIFS_ECHO_OP);
}

int
SMB2_echo(struct TCP_Server_Info *server)
{
	struct smb2_echo_req *req;
	int rc = 0;
	struct kvec iov;

	cFYI(1, "In echo request");

	rc = small_smb2_init(SMB2_ECHO, NULL, (void **)&req);
	if (rc)
		return rc;

	req->hdr.CreditRequest = cpu_to_le16(1);

	iov.iov_base = (char *)req;
	/* 4 for rfc1002 length field */
	iov.iov_len = get_rfc1002_length(req) + 4;

	rc = cifs_call_async(server, &iov, 1, NULL, smb2_echo_callback, server,
			     CIFS_ECHO_OP);
	if (rc)
		cFYI(1, "Echo request failed: %d", rc);

	cifs_small_buf_release(req);
	return rc;
}