summaryrefslogtreecommitdiff
path: root/fs/cifs/sess.c
blob: e8c5dc9f338670bec2859fc51d10337d13a0fbb7 (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
/*
 *   fs/cifs/sess.c
 *
 *   SMB/CIFS session setup handling routines
 *
 *   Copyright (c) International Business Machines  Corp., 2006, 2009
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *
 *   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
 */

#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "ntlmssp.h"
#include "nterr.h"
#include <linux/utsname.h>
#include <linux/slab.h>
#include "cifs_spnego.h"

/*
 * Checks if this is the first smb session to be reconnected after
 * the socket has been reestablished (so we know whether to use vc 0).
 * Called while holding the cifs_tcp_ses_lock, so do not block
 */
static bool is_first_ses_reconnect(struct cifs_ses *ses)
{
	struct list_head *tmp;
	struct cifs_ses *tmp_ses;

	list_for_each(tmp, &ses->server->smb_ses_list) {
		tmp_ses = list_entry(tmp, struct cifs_ses,
				     smb_ses_list);
		if (tmp_ses->need_reconnect == false)
			return false;
	}
	/* could not find a session that was already connected,
	   this must be the first one we are reconnecting */
	return true;
}

/*
 *	vc number 0 is treated specially by some servers, and should be the
 *      first one we request.  After that we can use vcnumbers up to maxvcs,
 *	one for each smb session (some Windows versions set maxvcs incorrectly
 *	so maxvc=1 can be ignored).  If we have too many vcs, we can reuse
 *	any vc but zero (some servers reset the connection on vcnum zero)
 *
 */
static __le16 get_next_vcnum(struct cifs_ses *ses)
{
	__u16 vcnum = 0;
	struct list_head *tmp;
	struct cifs_ses *tmp_ses;
	__u16 max_vcs = ses->server->max_vcs;
	__u16 i;
	int free_vc_found = 0;

	/* Quoting the MS-SMB specification: "Windows-based SMB servers set this
	field to one but do not enforce this limit, which allows an SMB client
	to establish more virtual circuits than allowed by this value ... but
	other server implementations can enforce this limit." */
	if (max_vcs < 2)
		max_vcs = 0xFFFF;

	spin_lock(&cifs_tcp_ses_lock);
	if ((ses->need_reconnect) && is_first_ses_reconnect(ses))
			goto get_vc_num_exit;  /* vcnum will be zero */
	for (i = ses->server->srv_count - 1; i < max_vcs; i++) {
		if (i == 0) /* this is the only connection, use vc 0 */
			break;

		free_vc_found = 1;

		list_for_each(tmp, &ses->server->smb_ses_list) {
			tmp_ses = list_entry(tmp, struct cifs_ses,
					     smb_ses_list);
			if (tmp_ses->vcnum == i) {
				free_vc_found = 0;
				break; /* found duplicate, try next vcnum */
			}
		}
		if (free_vc_found)
			break; /* we found a vcnumber that will work - use it */
	}

	if (i == 0)
		vcnum = 0; /* for most common case, ie if one smb session, use
			      vc zero.  Also for case when no free vcnum, zero
			      is safest to send (some clients only send zero) */
	else if (free_vc_found == 0)
		vcnum = 1;  /* we can not reuse vc=0 safely, since some servers
				reset all uids on that, but 1 is ok. */
	else
		vcnum = i;
	ses->vcnum = vcnum;
get_vc_num_exit:
	spin_unlock(&cifs_tcp_ses_lock);

	return cpu_to_le16(vcnum);
}

static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, SESSION_SETUP_ANDX *pSMB)
{
	__u32 capabilities = 0;

	/* init fields common to all four types of SessSetup */
	/* Note that offsets for first seven fields in req struct are same  */
	/*	in CIFS Specs so does not matter which of 3 forms of struct */
	/*	that we use in next few lines                               */
	/* Note that header is initialized to zero in header_assemble */
	pSMB->req.AndXCommand = 0xFF;
	pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
					CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
					USHRT_MAX));
	pSMB->req.MaxMpxCount = cpu_to_le16(ses->server->maxReq);
	pSMB->req.VcNumber = get_next_vcnum(ses);

	/* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */

	/* BB verify whether signing required on neg or just on auth frame
	   (and NTLM case) */

	capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
			CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;

	if (ses->server->sec_mode &
	    (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED))
		pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;

	if (ses->capabilities & CAP_UNICODE) {
		pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
		capabilities |= CAP_UNICODE;
	}
	if (ses->capabilities & CAP_STATUS32) {
		pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
		capabilities |= CAP_STATUS32;
	}
	if (ses->capabilities & CAP_DFS) {
		pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
		capabilities |= CAP_DFS;
	}
	if (ses->capabilities & CAP_UNIX)
		capabilities |= CAP_UNIX;

	return capabilities;
}

static void
unicode_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
{
	char *bcc_ptr = *pbcc_area;
	int bytes_ret = 0;

	/* Copy OS version */
	bytes_ret = cifs_strtoUTF16((__le16 *)bcc_ptr, "Linux version ", 32,
				    nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, init_utsname()->release,
				    32, nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2; /* trailing null */

	bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
				    32, nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2; /* trailing null */

	*pbcc_area = bcc_ptr;
}

static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
				   const struct nls_table *nls_cp)
{
	char *bcc_ptr = *pbcc_area;
	int bytes_ret = 0;

	/* copy domain */
	if (ses->domainName == NULL) {
		/* Sending null domain better than using a bogus domain name (as
		we did briefly in 2.6.18) since server will use its default */
		*bcc_ptr = 0;
		*(bcc_ptr+1) = 0;
		bytes_ret = 0;
	} else
		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,
					    256, nls_cp);
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2;  /* account for null terminator */

	*pbcc_area = bcc_ptr;
}


static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
				   const struct nls_table *nls_cp)
{
	char *bcc_ptr = *pbcc_area;
	int bytes_ret = 0;

	/* BB FIXME add check that strings total less
	than 335 or will need to send them as arrays */

	/* unicode strings, must be word aligned before the call */
/*	if ((long) bcc_ptr % 2)	{
		*bcc_ptr = 0;
		bcc_ptr++;
	} */
	/* copy user */
	if (ses->user_name == NULL) {
		/* null user mount */
		*bcc_ptr = 0;
		*(bcc_ptr+1) = 0;
	} else {
		bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->user_name,
					    MAX_USERNAME_SIZE, nls_cp);
	}
	bcc_ptr += 2 * bytes_ret;
	bcc_ptr += 2; /* account for null termination */

	unicode_domain_string(&bcc_ptr, ses, nls_cp);
	unicode_oslm_strings(&bcc_ptr, nls_cp);

	*pbcc_area = bcc_ptr;
}

static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
				 const struct nls_table *nls_cp)
{
	char *bcc_ptr = *pbcc_area;

	/* copy user */
	/* BB what about null user mounts - check that we do this BB */
	/* copy user */
	if (ses->user_name != NULL) {
		strncpy(bcc_ptr, ses->user_name, MAX_USERNAME_SIZE);
		bcc_ptr += strnlen(ses->user_name, MAX_USERNAME_SIZE);
	}
	/* else null user mount */
	*bcc_ptr = 0;
	bcc_ptr++; /* account for null termination */

	/* copy domain */
	if (ses->domainName != NULL) {
		strncpy(bcc_ptr, ses->domainName, 256);
		bcc_ptr += strnlen(ses->domainName, 256);
	} /* else we will send a null domain name
	     so the server will default to its own domain */
	*bcc_ptr = 0;
	bcc_ptr++;

	/* BB check for overflow here */

	strcpy(bcc_ptr, "Linux version ");
	bcc_ptr += strlen("Linux version ");
	strcpy(bcc_ptr, init_utsname()->release);
	bcc_ptr += strlen(init_utsname()->release) + 1;

	strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
	bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;

	*pbcc_area = bcc_ptr;
}

static void
decode_unicode_ssetup(char **pbcc_area, int bleft, struct cifs_ses *ses,
		      const struct nls_table *nls_cp)
{
	int len;
	char *data = *pbcc_area;

	cifs_dbg(FYI, "bleft %d\n", bleft);

	kfree(ses->serverOS);
	ses->serverOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
	cifs_dbg(FYI, "serverOS=%s\n", ses->serverOS);
	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
	data += len;
	bleft -= len;
	if (bleft <= 0)
		return;

	kfree(ses->serverNOS);
	ses->serverNOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
	cifs_dbg(FYI, "serverNOS=%s\n", ses->serverNOS);
	len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
	data += len;
	bleft -= len;
	if (bleft <= 0)
		return;

	kfree(ses->serverDomain);
	ses->serverDomain = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
	cifs_dbg(FYI, "serverDomain=%s\n", ses->serverDomain);

	return;
}

static void decode_ascii_ssetup(char **pbcc_area, __u16 bleft,
				struct cifs_ses *ses,
				const struct nls_table *nls_cp)
{
	int len;
	char *bcc_ptr = *pbcc_area;

	cifs_dbg(FYI, "decode sessetup ascii. bleft %d\n", bleft);

	len = strnlen(bcc_ptr, bleft);
	if (len >= bleft)
		return;

	kfree(ses->serverOS);

	ses->serverOS = kzalloc(len + 1, GFP_KERNEL);
	if (ses->serverOS)
		strncpy(ses->serverOS, bcc_ptr, len);
	if (strncmp(ses->serverOS, "OS/2", 4) == 0) {
		cifs_dbg(FYI, "OS/2 server\n");
			ses->flags |= CIFS_SES_OS2;
	}

	bcc_ptr += len + 1;
	bleft -= len + 1;

	len = strnlen(bcc_ptr, bleft);
	if (len >= bleft)
		return;

	kfree(ses->serverNOS);

	ses->serverNOS = kzalloc(len + 1, GFP_KERNEL);
	if (ses->serverNOS)
		strncpy(ses->serverNOS, bcc_ptr, len);

	bcc_ptr += len + 1;
	bleft -= len + 1;

	len = strnlen(bcc_ptr, bleft);
	if (len > bleft)
		return;

	/* No domain field in LANMAN case. Domain is
	   returned by old servers in the SMB negprot response */
	/* BB For newer servers which do not support Unicode,
	   but thus do return domain here we could add parsing
	   for it later, but it is not very important */
	cifs_dbg(FYI, "ascii: bytes left %d\n", bleft);
}

int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
				    struct cifs_ses *ses)
{
	unsigned int tioffset; /* challenge message target info area */
	unsigned int tilen; /* challenge message target info area length  */

	CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;

	if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
		cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len);
		return -EINVAL;
	}

	if (memcmp(pblob->Signature, "NTLMSSP", 8)) {
		cifs_dbg(VFS, "blob signature incorrect %s\n",
			 pblob->Signature);
		return -EINVAL;
	}
	if (pblob->MessageType != NtLmChallenge) {
		cifs_dbg(VFS, "Incorrect message type %d\n",
			 pblob->MessageType);
		return -EINVAL;
	}

	memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
	/* BB we could decode pblob->NegotiateFlags; some may be useful */
	/* In particular we can examine sign flags */
	/* BB spec says that if AvId field of MsvAvTimestamp is populated then
		we must set the MIC field of the AUTHENTICATE_MESSAGE */
	ses->ntlmssp->server_flags = le32_to_cpu(pblob->NegotiateFlags);
	tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
	tilen = le16_to_cpu(pblob->TargetInfoArray.Length);
	if (tioffset > blob_len || tioffset + tilen > blob_len) {
		cifs_dbg(VFS, "tioffset + tilen too high %u + %u",
			tioffset, tilen);
		return -EINVAL;
	}
	if (tilen) {
		ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
						 GFP_KERNEL);
		if (!ses->auth_key.response) {
			cifs_dbg(VFS, "Challenge target info alloc failure");
			return -ENOMEM;
		}
		ses->auth_key.len = tilen;
	}

	return 0;
}

/* BB Move to ntlmssp.c eventually */

/* We do not malloc the blob, it is passed in pbuffer, because
   it is fixed size, and small, making this approach cleaner */
void build_ntlmssp_negotiate_blob(unsigned char *pbuffer,
					 struct cifs_ses *ses)
{
	NEGOTIATE_MESSAGE *sec_blob = (NEGOTIATE_MESSAGE *)pbuffer;
	__u32 flags;

	memset(pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
	sec_blob->MessageType = NtLmNegotiate;

	/* BB is NTLMV2 session security format easier to use here? */
	flags = NTLMSSP_NEGOTIATE_56 |	NTLMSSP_REQUEST_TARGET |
		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
	if (ses->server->sec_mode &
			(SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
		flags |= NTLMSSP_NEGOTIATE_SIGN;
		if (!ses->server->session_estab)
			flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
	}

	sec_blob->NegotiateFlags = cpu_to_le32(flags);

	sec_blob->WorkstationName.BufferOffset = 0;
	sec_blob->WorkstationName.Length = 0;
	sec_blob->WorkstationName.MaximumLength = 0;

	/* Domain name is sent on the Challenge not Negotiate NTLMSSP request */
	sec_blob->DomainName.BufferOffset = 0;
	sec_blob->DomainName.Length = 0;
	sec_blob->DomainName.MaximumLength = 0;
}

/* We do not malloc the blob, it is passed in pbuffer, because its
   maximum possible size is fixed and small, making this approach cleaner.
   This function returns the length of the data in the blob */
int build_ntlmssp_auth_blob(unsigned char *pbuffer,
					u16 *buflen,
				   struct cifs_ses *ses,
				   const struct nls_table *nls_cp)
{
	int rc;
	AUTHENTICATE_MESSAGE *sec_blob = (AUTHENTICATE_MESSAGE *)pbuffer;
	__u32 flags;
	unsigned char *tmp;

	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
	sec_blob->MessageType = NtLmAuthenticate;

	flags = NTLMSSP_NEGOTIATE_56 |
		NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO |
		NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
		NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC;
	if (ses->server->sec_mode &
	   (SECMODE_SIGN_REQUIRED | SECMODE_SIGN_ENABLED)) {
		flags |= NTLMSSP_NEGOTIATE_SIGN;
		if (!ses->server->session_estab)
			flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
	}

	tmp = pbuffer + sizeof(AUTHENTICATE_MESSAGE);
	sec_blob->NegotiateFlags = cpu_to_le32(flags);

	sec_blob->LmChallengeResponse.BufferOffset =
				cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
	sec_blob->LmChallengeResponse.Length = 0;
	sec_blob->LmChallengeResponse.MaximumLength = 0;

	sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
	rc = setup_ntlmv2_rsp(ses, nls_cp);
	if (rc) {
		cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
		goto setup_ntlmv2_ret;
	}
	memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
			ses->auth_key.len - CIFS_SESS_KEY_SIZE);
	tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;

	sec_blob->NtChallengeResponse.Length =
			cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
	sec_blob->NtChallengeResponse.MaximumLength =
			cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);

	if (ses->domainName == NULL) {
		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
		sec_blob->DomainName.Length = 0;
		sec_blob->DomainName.MaximumLength = 0;
		tmp += 2;
	} else {
		int len;
		len = cifs_strtoUTF16((__le16 *)tmp, ses->domainName,
				      MAX_USERNAME_SIZE, nls_cp);
		len *= 2; /* unicode is 2 bytes each */
		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
		sec_blob->DomainName.Length = cpu_to_le16(len);
		sec_blob->DomainName.MaximumLength = cpu_to_le16(len);
		tmp += len;
	}

	if (ses->user_name == NULL) {
		sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
		sec_blob->UserName.Length = 0;
		sec_blob->UserName.MaximumLength = 0;
		tmp += 2;
	} else {
		int len;
		len = cifs_strtoUTF16((__le16 *)tmp, ses->user_name,
				      MAX_USERNAME_SIZE, nls_cp);
		len *= 2; /* unicode is 2 bytes each */
		sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
		sec_blob->UserName.Length = cpu_to_le16(len);
		sec_blob->UserName.MaximumLength = cpu_to_le16(len);
		tmp += len;
	}

	sec_blob->WorkstationName.BufferOffset = cpu_to_le32(tmp - pbuffer);
	sec_blob->WorkstationName.Length = 0;
	sec_blob->WorkstationName.MaximumLength = 0;
	tmp += 2;

	if (((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) ||
		(ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC))
			&& !calc_seckey(ses)) {
		memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
		sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
		sec_blob->SessionKey.MaximumLength =
				cpu_to_le16(CIFS_CPHTXT_SIZE);
		tmp += CIFS_CPHTXT_SIZE;
	} else {
		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
		sec_blob->SessionKey.Length = 0;
		sec_blob->SessionKey.MaximumLength = 0;
	}

setup_ntlmv2_ret:
	*buflen = tmp - pbuffer;
	return rc;
}

int
CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
	       const struct nls_table *nls_cp)
{
	int rc = 0;
	int wct;
	struct smb_hdr *smb_buf;
	char *bcc_ptr;
	char *str_area;
	SESSION_SETUP_ANDX *pSMB;
	__u32 capabilities;
	__u16 count;
	int resp_buf_type;
	struct kvec iov[3];
	enum securityEnum type;
	__u16 action, bytes_remaining;
	struct key *spnego_key = NULL;
	__le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
	u16 blob_len;
	char *ntlmsspblob = NULL;

	if (ses == NULL) {
		WARN(1, "%s: ses == NULL!", __func__);
		return -EINVAL;
	}

	type = ses->server->secType;
	cifs_dbg(FYI, "sess setup type %d\n", type);
	if (type == RawNTLMSSP) {
		/* 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;
	}

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

	if (type == LANMAN) {
#ifndef CONFIG_CIFS_WEAK_PW_HASH
		/* LANMAN and plaintext are less secure and off by default.
		So we make this explicitly be turned on in kconfig (in the
		build) and turned on at runtime (changed from the default)
		in proc/fs/cifs or via mount parm.  Unfortunately this is
		needed for old Win (e.g. Win95), some obscure NAS and OS/2 */
		return -EOPNOTSUPP;
#endif
		wct = 10; /* lanman 2 style sessionsetup */
	} else if ((type == NTLM) || (type == NTLMv2)) {
		/* For NTLMv2 failures eventually may need to retry NTLM */
		wct = 13; /* old style NTLM sessionsetup */
	} else /* same size: negotiate or auth, NTLMSSP or extended security */
		wct = 12;

	rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
			    (void **)&smb_buf);
	if (rc)
		return rc;

	pSMB = (SESSION_SETUP_ANDX *)smb_buf;

	capabilities = cifs_ssetup_hdr(ses, pSMB);

	/* we will send the SMB in three pieces:
	a fixed length beginning part, an optional
	SPNEGO blob (which can be zero length), and a
	last part which will include the strings
	and rest of bcc area. This allows us to avoid
	a large buffer 17K allocation */
	iov[0].iov_base = (char *)pSMB;
	iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;

	/* setting this here allows the code at the end of the function
	   to free the request buffer if there's an error */
	resp_buf_type = CIFS_SMALL_BUFFER;

	/* 2000 big enough to fit max user, domain, NOS name etc. */
	str_area = kmalloc(2000, GFP_KERNEL);
	if (str_area == NULL) {
		rc = -ENOMEM;
		goto ssetup_exit;
	}
	bcc_ptr = str_area;

	ses->flags &= ~CIFS_SES_LANMAN;

	iov[1].iov_base = NULL;
	iov[1].iov_len = 0;

	if (type == LANMAN) {
#ifdef CONFIG_CIFS_WEAK_PW_HASH
		char lnm_session_key[CIFS_AUTH_RESP_SIZE];

		pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;

		/* no capabilities flags in old lanman negotiation */

		pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);

		/* Calculate hash with password and copy into bcc_ptr.
		 * Encryption Key (stored as in cryptkey) gets used if the
		 * security mode bit in Negottiate Protocol response states
		 * to use challenge/response method (i.e. Password bit is 1).
		 */

		rc = calc_lanman_hash(ses->password, ses->server->cryptkey,
				 ses->server->sec_mode & SECMODE_PW_ENCRYPT ?
					true : false, lnm_session_key);

		ses->flags |= CIFS_SES_LANMAN;
		memcpy(bcc_ptr, (char *)lnm_session_key, CIFS_AUTH_RESP_SIZE);
		bcc_ptr += CIFS_AUTH_RESP_SIZE;

		/* can not sign if LANMAN negotiated so no need
		to calculate signing key? but what if server
		changed to do higher than lanman dialect and
		we reconnected would we ever calc signing_key? */

		cifs_dbg(FYI, "Negotiating LANMAN setting up strings\n");
		/* Unicode not allowed for LANMAN dialects */
		ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
#endif
	} else if (type == NTLM) {
		pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
		pSMB->req_no_secext.CaseInsensitivePasswordLength =
			cpu_to_le16(CIFS_AUTH_RESP_SIZE);
		pSMB->req_no_secext.CaseSensitivePasswordLength =
			cpu_to_le16(CIFS_AUTH_RESP_SIZE);

		/* calculate ntlm response and session key */
		rc = setup_ntlm_response(ses, nls_cp);
		if (rc) {
			cifs_dbg(VFS, "Error %d during NTLM authentication\n",
				 rc);
			goto ssetup_exit;
		}

		/* copy ntlm response */
		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
				CIFS_AUTH_RESP_SIZE);
		bcc_ptr += CIFS_AUTH_RESP_SIZE;
		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
				CIFS_AUTH_RESP_SIZE);
		bcc_ptr += CIFS_AUTH_RESP_SIZE;

		if (ses->capabilities & CAP_UNICODE) {
			/* unicode strings must be word aligned */
			if (iov[0].iov_len % 2) {
				*bcc_ptr = 0;
				bcc_ptr++;
			}
			unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
		} else
			ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
	} else if (type == NTLMv2) {
		pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);

		/* LM2 password would be here if we supported it */
		pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;

		/* calculate nlmv2 response and session key */
		rc = setup_ntlmv2_rsp(ses, nls_cp);
		if (rc) {
			cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n",
				 rc);
			goto ssetup_exit;
		}
		memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
				ses->auth_key.len - CIFS_SESS_KEY_SIZE);
		bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;

		/* set case sensitive password length after tilen may get
		 * assigned, tilen is 0 otherwise.
		 */
		pSMB->req_no_secext.CaseSensitivePasswordLength =
			cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);

		if (ses->capabilities & CAP_UNICODE) {
			if (iov[0].iov_len % 2) {
				*bcc_ptr = 0;
				bcc_ptr++;
			}
			unicode_ssetup_strings(&bcc_ptr, ses, nls_cp);
		} else
			ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
	} else if (type == Kerberos) {
#ifdef CONFIG_CIFS_UPCALL
		struct cifs_spnego_msg *msg;

		spnego_key = cifs_get_spnego_key(ses);
		if (IS_ERR(spnego_key)) {
			rc = PTR_ERR(spnego_key);
			spnego_key = NULL;
			goto ssetup_exit;
		}

		msg = spnego_key->payload.data;
		/* check version field to make sure that cifs.upcall is
		   sending us a response in an expected form */
		if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
			cifs_dbg(VFS, "incorrect version of cifs.upcall "
				   "expected %d but got %d)",
				   CIFS_SPNEGO_UPCALL_VERSION, msg->version);
			rc = -EKEYREJECTED;
			goto ssetup_exit;
		}

		ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
						 GFP_KERNEL);
		if (!ses->auth_key.response) {
			cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory",
					msg->sesskey_len);
			rc = -ENOMEM;
			goto ssetup_exit;
		}
		ses->auth_key.len = msg->sesskey_len;

		pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
		capabilities |= CAP_EXTENDED_SECURITY;
		pSMB->req.Capabilities = cpu_to_le32(capabilities);
		iov[1].iov_base = msg->data + msg->sesskey_len;
		iov[1].iov_len = msg->secblob_len;
		pSMB->req.SecurityBlobLength = cpu_to_le16(iov[1].iov_len);

		if (ses->capabilities & CAP_UNICODE) {
			/* unicode strings must be word aligned */
			if ((iov[0].iov_len + iov[1].iov_len) % 2) {
				*bcc_ptr = 0;
				bcc_ptr++;
			}
			unicode_oslm_strings(&bcc_ptr, nls_cp);
			unicode_domain_string(&bcc_ptr, ses, nls_cp);
		} else
		/* BB: is this right? */
			ascii_ssetup_strings(&bcc_ptr, ses, nls_cp);
#else /* ! CONFIG_CIFS_UPCALL */
		cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
		rc = -ENOSYS;
		goto ssetup_exit;
#endif /* CONFIG_CIFS_UPCALL */
	} else if (type == RawNTLMSSP) {
		if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
			cifs_dbg(VFS, "NTLMSSP requires Unicode support\n");
			rc = -ENOSYS;
			goto ssetup_exit;
		}

		cifs_dbg(FYI, "ntlmssp session setup phase %d\n", phase);
		pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
		capabilities |= CAP_EXTENDED_SECURITY;
		pSMB->req.Capabilities |= cpu_to_le32(capabilities);
		switch(phase) {
		case NtLmNegotiate:
			build_ntlmssp_negotiate_blob(
				pSMB->req.SecurityBlob, ses);
			iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
			iov[1].iov_base = pSMB->req.SecurityBlob;
			pSMB->req.SecurityBlobLength =
				cpu_to_le16(sizeof(NEGOTIATE_MESSAGE));
			break;
		case NtLmAuthenticate:
			/*
			 * 5 is an empirical value, large enough to hold
			 * authenticate message plus max 10 of av paris,
			 * domain, user, workstation names, flags, etc.
			 */
			ntlmsspblob = kzalloc(
				5*sizeof(struct _AUTHENTICATE_MESSAGE),
				GFP_KERNEL);
			if (!ntlmsspblob) {
				rc = -ENOMEM;
				goto ssetup_exit;
			}

			rc = build_ntlmssp_auth_blob(ntlmsspblob,
						&blob_len, ses, nls_cp);
			if (rc)
				goto ssetup_exit;
			iov[1].iov_len = blob_len;
			iov[1].iov_base = ntlmsspblob;
			pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
			/*
			 * Make sure that we tell the server that we are using
			 * the uid that it just gave us back on the response
			 * (challenge)
			 */
			smb_buf->Uid = ses->Suid;
			break;
		default:
			cifs_dbg(VFS, "invalid phase %d\n", phase);
			rc = -ENOSYS;
			goto ssetup_exit;
		}
		/* unicode strings must be word aligned */
		if ((iov[0].iov_len + iov[1].iov_len) % 2) {
			*bcc_ptr = 0;
			bcc_ptr++;
		}
		unicode_oslm_strings(&bcc_ptr, nls_cp);
	} else {
		cifs_dbg(VFS, "secType %d not supported!\n", type);
		rc = -ENOSYS;
		goto ssetup_exit;
	}

	iov[2].iov_base = str_area;
	iov[2].iov_len = (long) bcc_ptr - (long) str_area;

	count = iov[1].iov_len + iov[2].iov_len;
	smb_buf->smb_buf_length =
		cpu_to_be32(be32_to_cpu(smb_buf->smb_buf_length) + count);

	put_bcc(count, smb_buf);

	rc = SendReceive2(xid, ses, iov, 3 /* num_iovecs */, &resp_buf_type,
			  CIFS_LOG_ERROR);
	/* SMB request buf freed in SendReceive2 */

	pSMB = (SESSION_SETUP_ANDX *)iov[0].iov_base;
	smb_buf = (struct smb_hdr *)iov[0].iov_base;

	if ((type == RawNTLMSSP) && (resp_buf_type != CIFS_NO_BUFFER) &&
	    (smb_buf->Status.CifsError ==
			cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))) {
		if (phase != NtLmNegotiate) {
			cifs_dbg(VFS, "Unexpected more processing error\n");
			goto ssetup_exit;
		}
		/* NTLMSSP Negotiate sent now processing challenge (response) */
		phase = NtLmChallenge; /* process ntlmssp challenge */
		rc = 0; /* MORE_PROC rc is not an error here, but expected */
	}
	if (rc)
		goto ssetup_exit;

	if ((smb_buf->WordCount != 3) && (smb_buf->WordCount != 4)) {
		rc = -EIO;
		cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
		goto ssetup_exit;
	}
	action = le16_to_cpu(pSMB->resp.Action);
	if (action & GUEST_LOGIN)
		cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
	ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
	cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
	/* response can have either 3 or 4 word count - Samba sends 3 */
	/* and lanman response is 3 */
	bytes_remaining = get_bcc(smb_buf);
	bcc_ptr = pByteArea(smb_buf);

	if (smb_buf->WordCount == 4) {
		blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
		if (blob_len > bytes_remaining) {
			cifs_dbg(VFS, "bad security blob length %d\n",
				 blob_len);
			rc = -EINVAL;
			goto ssetup_exit;
		}
		if (phase == NtLmChallenge) {
			rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
			/* now goto beginning for ntlmssp authenticate phase */
			if (rc)
				goto ssetup_exit;
		}
		bcc_ptr += blob_len;
		bytes_remaining -= blob_len;
	}

	/* BB check if Unicode and decode strings */
	if (bytes_remaining == 0) {
		/* no string area to decode, do nothing */
	} else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
		/* unicode string area must be word-aligned */
		if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
			++bcc_ptr;
			--bytes_remaining;
		}
		decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses, nls_cp);
	} else {
		decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses, nls_cp);
	}

ssetup_exit:
	if (spnego_key) {
		key_invalidate(spnego_key);
		key_put(spnego_key);
	}
	kfree(str_area);
	kfree(ntlmsspblob);
	ntlmsspblob = NULL;
	if (resp_buf_type == CIFS_SMALL_BUFFER) {
		cifs_dbg(FYI, "ssetup freeing small buf %p\n", iov[0].iov_base);
		cifs_small_buf_release(iov[0].iov_base);
	} else if (resp_buf_type == CIFS_LARGE_BUFFER)
		cifs_buf_release(iov[0].iov_base);

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

	return rc;
}