summaryrefslogtreecommitdiff
path: root/fs/cifs/smb2transport.c
blob: 8806f3f76c1d6c25c88bf98ba66aadd332d73b09 (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
/*
 *   fs/cifs/smb2transport.c
 *
 *   Copyright (C) International Business Machines  Corp., 2002, 2011
 *                 Etersoft, 2012
 *   Author(s): Steve French (sfrench@us.ibm.com)
 *              Jeremy Allison (jra@samba.org) 2006
 *              Pavel Shilovsky (pshilovsky@samba.org) 2012
 *
 *   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 <linux/fs.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/net.h>
#include <linux/delay.h>
#include <linux/uaccess.h>
#include <asm/processor.h>
#include <linux/mempool.h>
#include <linux/highmem.h>
#include <crypto/aead.h>
#include "smb2pdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "smb2proto.h"
#include "cifs_debug.h"
#include "smb2status.h"
#include "smb2glob.h"

static int
smb2_crypto_shash_allocate(struct TCP_Server_Info *server)
{
	return cifs_alloc_hash("hmac(sha256)",
			       &server->secmech.hmacsha256,
			       &server->secmech.sdeschmacsha256);
}

static int
smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
{
	struct cifs_secmech *p = &server->secmech;
	int rc;

	rc = cifs_alloc_hash("hmac(sha256)",
			     &p->hmacsha256,
			     &p->sdeschmacsha256);
	if (rc)
		goto err;

	rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
	if (rc)
		goto err;

	return 0;
err:
	cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
	return rc;
}

#ifdef CONFIG_CIFS_SMB311
int
smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
{
	struct cifs_secmech *p = &server->secmech;
	int rc = 0;

	rc = cifs_alloc_hash("hmac(sha256)",
			     &p->hmacsha256,
			     &p->sdeschmacsha256);
	if (rc)
		return rc;

	rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
	if (rc)
		goto err;

	rc = cifs_alloc_hash("sha512", &p->sha512, &p->sdescsha512);
	if (rc)
		goto err;

	return 0;

err:
	cifs_free_hash(&p->cmacaes, &p->sdesccmacaes);
	cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
	return rc;
}
#endif

static struct cifs_ses *
smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
{
	struct cifs_ses *ses;

	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
		if (ses->Suid != ses_id)
			continue;
		return ses;
	}

	return NULL;
}

struct cifs_ses *
smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
{
	struct cifs_ses *ses;

	spin_lock(&cifs_tcp_ses_lock);
	ses = smb2_find_smb_ses_unlocked(server, ses_id);
	spin_unlock(&cifs_tcp_ses_lock);

	return ses;
}

static struct cifs_tcon *
smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32  tid)
{
	struct cifs_tcon *tcon;

	list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
		if (tcon->tid != tid)
			continue;
		++tcon->tc_count;
		return tcon;
	}

	return NULL;
}

/*
 * Obtain tcon corresponding to the tid in the given
 * cifs_ses
 */

struct cifs_tcon *
smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32  tid)
{
	struct cifs_ses *ses;
	struct cifs_tcon *tcon;

	spin_lock(&cifs_tcp_ses_lock);
	ses = smb2_find_smb_ses_unlocked(server, ses_id);
	if (!ses) {
		spin_unlock(&cifs_tcp_ses_lock);
		return NULL;
	}
	tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
	spin_unlock(&cifs_tcp_ses_lock);

	return tcon;
}

int
smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
{
	int rc;
	unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
	unsigned char *sigptr = smb2_signature;
	struct kvec *iov = rqst->rq_iov;
	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
	struct cifs_ses *ses;

	ses = smb2_find_smb_ses(server, shdr->SessionId);
	if (!ses) {
		cifs_dbg(VFS, "%s: Could not find session\n", __func__);
		return 0;
	}

	memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
	memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);

	rc = smb2_crypto_shash_allocate(server);
	if (rc) {
		cifs_dbg(VFS, "%s: shah256 alloc failed\n", __func__);
		return rc;
	}

	rc = crypto_shash_setkey(server->secmech.hmacsha256,
		ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
		return rc;
	}

	rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init sha256", __func__);
		return rc;
	}

	rc = __cifs_calc_signature(rqst, server, sigptr,
		&server->secmech.sdeschmacsha256->shash);

	if (!rc)
		memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);

	return rc;
}

static int generate_key(struct cifs_ses *ses, struct kvec label,
			struct kvec context, __u8 *key, unsigned int key_size)
{
	unsigned char zero = 0x0;
	__u8 i[4] = {0, 0, 0, 1};
	__u8 L[4] = {0, 0, 0, 128};
	int rc = 0;
	unsigned char prfhash[SMB2_HMACSHA256_SIZE];
	unsigned char *hashptr = prfhash;

	memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
	memset(key, 0x0, key_size);

	rc = smb3_crypto_shash_allocate(ses->server);
	if (rc) {
		cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_setkey(ses->server->secmech.hmacsha256,
		ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
				i, 4);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
				label.iov_base, label.iov_len);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
				&zero, 1);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
				context.iov_base, context.iov_len);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
				L, 4);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
		goto smb3signkey_ret;
	}

	rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash,
				hashptr);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
		goto smb3signkey_ret;
	}

	memcpy(key, hashptr, key_size);

smb3signkey_ret:
	return rc;
}

struct derivation {
	struct kvec label;
	struct kvec context;
};

struct derivation_triplet {
	struct derivation signing;
	struct derivation encryption;
	struct derivation decryption;
};

static int
generate_smb3signingkey(struct cifs_ses *ses,
			const struct derivation_triplet *ptriplet)
{
	int rc;

	rc = generate_key(ses, ptriplet->signing.label,
			  ptriplet->signing.context, ses->smb3signingkey,
			  SMB3_SIGN_KEY_SIZE);
	if (rc)
		return rc;

	rc = generate_key(ses, ptriplet->encryption.label,
			  ptriplet->encryption.context, ses->smb3encryptionkey,
			  SMB3_SIGN_KEY_SIZE);
	if (rc)
		return rc;

	rc = generate_key(ses, ptriplet->decryption.label,
			  ptriplet->decryption.context,
			  ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);

	if (rc)
		return rc;

#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
	cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
	/*
	 * The session id is opaque in terms of endianness, so we can't
	 * print it as a long long. we dump it as we got it on the wire
	 */
	cifs_dbg(VFS, "Session Id    %*ph\n", (int)sizeof(ses->Suid),
			&ses->Suid);
	cifs_dbg(VFS, "Session Key   %*ph\n",
		 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
	cifs_dbg(VFS, "Signing Key   %*ph\n",
		 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
	cifs_dbg(VFS, "ServerIn Key  %*ph\n",
		 SMB3_SIGN_KEY_SIZE, ses->smb3encryptionkey);
	cifs_dbg(VFS, "ServerOut Key %*ph\n",
		 SMB3_SIGN_KEY_SIZE, ses->smb3decryptionkey);
#endif
	return rc;
}

int
generate_smb30signingkey(struct cifs_ses *ses)

{
	struct derivation_triplet triplet;
	struct derivation *d;

	d = &triplet.signing;
	d->label.iov_base = "SMB2AESCMAC";
	d->label.iov_len = 12;
	d->context.iov_base = "SmbSign";
	d->context.iov_len = 8;

	d = &triplet.encryption;
	d->label.iov_base = "SMB2AESCCM";
	d->label.iov_len = 11;
	d->context.iov_base = "ServerIn ";
	d->context.iov_len = 10;

	d = &triplet.decryption;
	d->label.iov_base = "SMB2AESCCM";
	d->label.iov_len = 11;
	d->context.iov_base = "ServerOut";
	d->context.iov_len = 10;

	return generate_smb3signingkey(ses, &triplet);
}

#ifdef CONFIG_CIFS_SMB311
int
generate_smb311signingkey(struct cifs_ses *ses)

{
	struct derivation_triplet triplet;
	struct derivation *d;

	d = &triplet.signing;
	d->label.iov_base = "SMBSigningKey";
	d->label.iov_len = 14;
	d->context.iov_base = ses->preauth_sha_hash;
	d->context.iov_len = 64;

	d = &triplet.encryption;
	d->label.iov_base = "SMBC2SCipherKey";
	d->label.iov_len = 16;
	d->context.iov_base = ses->preauth_sha_hash;
	d->context.iov_len = 64;

	d = &triplet.decryption;
	d->label.iov_base = "SMBS2CCipherKey";
	d->label.iov_len = 16;
	d->context.iov_base = ses->preauth_sha_hash;
	d->context.iov_len = 64;

	return generate_smb3signingkey(ses, &triplet);
}
#endif /* 311 */

int
smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
{
	int rc = 0;
	unsigned char smb3_signature[SMB2_CMACAES_SIZE];
	unsigned char *sigptr = smb3_signature;
	struct kvec *iov = rqst->rq_iov;
	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[1].iov_base;
	struct cifs_ses *ses;

	ses = smb2_find_smb_ses(server, shdr->SessionId);
	if (!ses) {
		cifs_dbg(VFS, "%s: Could not find session\n", __func__);
		return 0;
	}

	memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
	memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);

	rc = crypto_shash_setkey(server->secmech.cmacaes,
		ses->smb3signingkey, SMB2_CMACAES_SIZE);

	if (rc) {
		cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
		return rc;
	}

	/*
	 * we already allocate sdesccmacaes when we init smb3 signing key,
	 * so unlike smb2 case we do not have to check here if secmech are
	 * initialized
	 */
	rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
	if (rc) {
		cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
		return rc;
	}

	rc = __cifs_calc_signature(rqst, server, sigptr,
				   &server->secmech.sdesccmacaes->shash);

	if (!rc)
		memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);

	return rc;
}

/* must be called with server->srv_mutex held */
static int
smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
{
	int rc = 0;
	struct smb2_sync_hdr *shdr =
			(struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;

	if (!(shdr->Flags & SMB2_FLAGS_SIGNED) ||
	    server->tcpStatus == CifsNeedNegotiate)
		return rc;

	if (!server->session_estab) {
		strncpy(shdr->Signature, "BSRSPYL", 8);
		return rc;
	}

	rc = server->ops->calc_signature(rqst, server);

	return rc;
}

int
smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
{
	unsigned int rc;
	char server_response_sig[16];
	struct smb2_sync_hdr *shdr =
			(struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;

	if ((shdr->Command == SMB2_NEGOTIATE) ||
	    (shdr->Command == SMB2_SESSION_SETUP) ||
	    (shdr->Command == SMB2_OPLOCK_BREAK) ||
	    (!server->session_estab))
		return 0;

	/*
	 * BB what if signatures are supposed to be on for session but
	 * server does not send one? BB
	 */

	/* Do not need to verify session setups with signature "BSRSPYL " */
	if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
		cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
			 shdr->Command);

	/*
	 * Save off the origiginal signature so we can modify the smb and check
	 * our calculated signature against what the server sent.
	 */
	memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);

	memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);

	mutex_lock(&server->srv_mutex);
	rc = server->ops->calc_signature(rqst, server);
	mutex_unlock(&server->srv_mutex);

	if (rc)
		return rc;

	if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE))
		return -EACCES;
	else
		return 0;
}

/*
 * Set message id for the request. Should be called after wait_for_free_request
 * and when srv_mutex is held.
 */
static inline void
smb2_seq_num_into_buf(struct TCP_Server_Info *server,
		      struct smb2_sync_hdr *shdr)
{
	unsigned int i, num = le16_to_cpu(shdr->CreditCharge);

	shdr->MessageId = get_next_mid64(server);
	/* skip message numbers according to CreditCharge field */
	for (i = 1; i < num; i++)
		get_next_mid(server);
}

static struct mid_q_entry *
smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
		     struct TCP_Server_Info *server)
{
	struct mid_q_entry *temp;

	if (server == NULL) {
		cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
		return NULL;
	}

	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
	memset(temp, 0, sizeof(struct mid_q_entry));
	temp->mid = le64_to_cpu(shdr->MessageId);
	temp->pid = current->pid;
	temp->command = shdr->Command; /* Always LE */
	temp->when_alloc = jiffies;
	temp->server = server;

	/*
	 * The default is for the mid to be synchronous, so the
	 * default callback just wakes up the current task.
	 */
	temp->callback = cifs_wake_up_task;
	temp->callback_data = current;

	atomic_inc(&midCount);
	temp->mid_state = MID_REQUEST_ALLOCATED;
	return temp;
}

static int
smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_sync_hdr *shdr,
		   struct mid_q_entry **mid)
{
	if (ses->server->tcpStatus == CifsExiting)
		return -ENOENT;

	if (ses->server->tcpStatus == CifsNeedReconnect) {
		cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
		return -EAGAIN;
	}

	if (ses->status == CifsNew) {
		if ((shdr->Command != SMB2_SESSION_SETUP) &&
		    (shdr->Command != SMB2_NEGOTIATE))
			return -EAGAIN;
		/* else ok - we are setting up session */
	}

	if (ses->status == CifsExiting) {
		if (shdr->Command != SMB2_LOGOFF)
			return -EAGAIN;
		/* else ok - we are shutting down the session */
	}

	*mid = smb2_mid_entry_alloc(shdr, ses->server);
	if (*mid == NULL)
		return -ENOMEM;
	spin_lock(&GlobalMid_Lock);
	list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
	spin_unlock(&GlobalMid_Lock);
	return 0;
}

int
smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
		   bool log_error)
{
	unsigned int len = mid->resp_buf_size;
	struct kvec iov[2];
	struct smb_rqst rqst = { .rq_iov = iov,
				 .rq_nvec = 2 };

	iov[0].iov_base = (char *)mid->resp_buf;
	iov[0].iov_len = 4;
	iov[1].iov_base = (char *)mid->resp_buf + 4;
	iov[1].iov_len = len;

	dump_smb(mid->resp_buf, min_t(u32, 80, len));
	/* convert the length into a more usable form */
	if (len > 24 && server->sign && !mid->decrypted) {
		int rc;

		rc = smb2_verify_signature(&rqst, server);
		if (rc)
			cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
				 rc);
	}

	return map_smb2_to_linux_error(mid->resp_buf, log_error);
}

struct mid_q_entry *
smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
{
	int rc;
	struct smb2_sync_hdr *shdr =
			(struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
	struct mid_q_entry *mid;

	smb2_seq_num_into_buf(ses->server, shdr);

	rc = smb2_get_mid_entry(ses, shdr, &mid);
	if (rc)
		return ERR_PTR(rc);
	rc = smb2_sign_rqst(rqst, ses->server);
	if (rc) {
		cifs_delete_mid(mid);
		return ERR_PTR(rc);
	}
	return mid;
}

struct mid_q_entry *
smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
{
	int rc;
	struct smb2_sync_hdr *shdr =
			(struct smb2_sync_hdr *)rqst->rq_iov[1].iov_base;
	struct mid_q_entry *mid;

	smb2_seq_num_into_buf(server, shdr);

	mid = smb2_mid_entry_alloc(shdr, server);
	if (mid == NULL)
		return ERR_PTR(-ENOMEM);

	rc = smb2_sign_rqst(rqst, server);
	if (rc) {
		DeleteMidQEntry(mid);
		return ERR_PTR(rc);
	}

	return mid;
}

int
smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
{
	struct crypto_aead *tfm;

	if (!server->secmech.ccmaesencrypt) {
		tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
		if (IS_ERR(tfm)) {
			cifs_dbg(VFS, "%s: Failed to alloc encrypt aead\n",
				 __func__);
			return PTR_ERR(tfm);
		}
		server->secmech.ccmaesencrypt = tfm;
	}

	if (!server->secmech.ccmaesdecrypt) {
		tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
		if (IS_ERR(tfm)) {
			crypto_free_aead(server->secmech.ccmaesencrypt);
			server->secmech.ccmaesencrypt = NULL;
			cifs_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
				 __func__);
			return PTR_ERR(tfm);
		}
		server->secmech.ccmaesdecrypt = tfm;
	}

	return 0;
}