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  1// SPDX-License-Identifier: LGPL-2.1
  2/*
  3 *   fs/cifs/smb2transport.c
  4 *
  5 *   Copyright (C) International Business Machines  Corp., 2002, 2011
  6 *                 Etersoft, 2012
  7 *   Author(s): Steve French (sfrench@us.ibm.com)
  8 *              Jeremy Allison (jra@samba.org) 2006
  9 *              Pavel Shilovsky (pshilovsky@samba.org) 2012
 10 *
 11 */
 12
 13#include <linux/fs.h>
 14#include <linux/list.h>
 15#include <linux/wait.h>
 16#include <linux/net.h>
 17#include <linux/delay.h>
 18#include <linux/uaccess.h>
 19#include <asm/processor.h>
 20#include <linux/mempool.h>
 21#include <linux/highmem.h>
 22#include <crypto/aead.h>
 23#include "smb2pdu.h"
 24#include "cifsglob.h"
 25#include "cifsproto.h"
 26#include "smb2proto.h"
 27#include "cifs_debug.h"
 28#include "smb2status.h"
 29#include "smb2glob.h"
 30
 31static int
 32smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
 33{
 34	struct cifs_secmech *p = &server->secmech;
 35	int rc;
 36
 37	rc = cifs_alloc_hash("hmac(sha256)",
 38			     &p->hmacsha256,
 39			     &p->sdeschmacsha256);
 40	if (rc)
 41		goto err;
 42
 43	rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
 44	if (rc)
 45		goto err;
 46
 47	return 0;
 48err:
 49	cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
 50	return rc;
 51}
 52
 53int
 54smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
 55{
 56	struct cifs_secmech *p = &server->secmech;
 57	int rc = 0;
 58
 59	rc = cifs_alloc_hash("hmac(sha256)",
 60			     &p->hmacsha256,
 61			     &p->sdeschmacsha256);
 62	if (rc)
 63		return rc;
 64
 65	rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
 66	if (rc)
 67		goto err;
 68
 69	rc = cifs_alloc_hash("sha512", &p->sha512, &p->sdescsha512);
 70	if (rc)
 71		goto err;
 72
 73	return 0;
 74
 75err:
 76	cifs_free_hash(&p->cmacaes, &p->sdesccmacaes);
 77	cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
 78	return rc;
 79}
 80
 81
 82static
 83int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
 84{
 85	struct cifs_chan *chan;
 86	struct cifs_ses *ses = NULL;
 87	struct TCP_Server_Info *it = NULL;
 88	int i;
 89	int rc = 0;
 90
 91	spin_lock(&cifs_tcp_ses_lock);
 92
 93	list_for_each_entry(it, &cifs_tcp_ses_list, tcp_ses_list) {
 94		list_for_each_entry(ses, &it->smb_ses_list, smb_ses_list) {
 95			if (ses->Suid == ses_id)
 96				goto found;
 97		}
 98	}
 99	cifs_server_dbg(VFS, "%s: Could not find session 0x%llx\n",
100			__func__, ses_id);
101	rc = -ENOENT;
102	goto out;
103
104found:
105	if (ses->binding) {
106		/*
107		 * If we are in the process of binding a new channel
108		 * to an existing session, use the master connection
109		 * session key
110		 */
111		memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
112		goto out;
113	}
114
115	/*
116	 * Otherwise, use the channel key.
117	 */
118
119	for (i = 0; i < ses->chan_count; i++) {
120		chan = ses->chans + i;
121		if (chan->server == server) {
122			memcpy(key, chan->signkey, SMB3_SIGN_KEY_SIZE);
123			goto out;
124		}
125	}
126
127	cifs_dbg(VFS,
128		 "%s: Could not find channel signing key for session 0x%llx\n",
129		 __func__, ses_id);
130	rc = -ENOENT;
131
132out:
133	spin_unlock(&cifs_tcp_ses_lock);
134	return rc;
135}
136
137static struct cifs_ses *
138smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
139{
140	struct cifs_ses *ses;
141
142	list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
143		if (ses->Suid != ses_id)
144			continue;
145		++ses->ses_count;
146		return ses;
147	}
148
149	return NULL;
150}
151
152struct cifs_ses *
153smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
154{
155	struct cifs_ses *ses;
156
157	spin_lock(&cifs_tcp_ses_lock);
158	ses = smb2_find_smb_ses_unlocked(server, ses_id);
159	spin_unlock(&cifs_tcp_ses_lock);
160
161	return ses;
162}
163
164static struct cifs_tcon *
165smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32  tid)
166{
167	struct cifs_tcon *tcon;
168
169	list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
170		if (tcon->tid != tid)
171			continue;
172		++tcon->tc_count;
173		return tcon;
174	}
175
176	return NULL;
177}
178
179/*
180 * Obtain tcon corresponding to the tid in the given
181 * cifs_ses
182 */
183
184struct cifs_tcon *
185smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32  tid)
186{
187	struct cifs_ses *ses;
188	struct cifs_tcon *tcon;
189
190	spin_lock(&cifs_tcp_ses_lock);
191	ses = smb2_find_smb_ses_unlocked(server, ses_id);
192	if (!ses) {
193		spin_unlock(&cifs_tcp_ses_lock);
194		return NULL;
195	}
196	tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
197	if (!tcon) {
198		cifs_put_smb_ses(ses);
199		spin_unlock(&cifs_tcp_ses_lock);
200		return NULL;
201	}
202	spin_unlock(&cifs_tcp_ses_lock);
203	/* tcon already has a ref to ses, so we don't need ses anymore */
204	cifs_put_smb_ses(ses);
205
206	return tcon;
207}
208
209int
210smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
211			bool allocate_crypto)
212{
213	int rc;
214	unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
215	unsigned char *sigptr = smb2_signature;
216	struct kvec *iov = rqst->rq_iov;
217	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
218	struct cifs_ses *ses;
219	struct shash_desc *shash;
220	struct crypto_shash *hash;
221	struct sdesc *sdesc = NULL;
222	struct smb_rqst drqst;
223
224	ses = smb2_find_smb_ses(server, shdr->SessionId);
225	if (!ses) {
226		cifs_server_dbg(VFS, "%s: Could not find session\n", __func__);
227		return 0;
228	}
229
230	memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
231	memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
232
233	if (allocate_crypto) {
234		rc = cifs_alloc_hash("hmac(sha256)", &hash, &sdesc);
235		if (rc) {
236			cifs_server_dbg(VFS,
237					"%s: sha256 alloc failed\n", __func__);
238			goto out;
239		}
240		shash = &sdesc->shash;
241	} else {
242		hash = server->secmech.hmacsha256;
243		shash = &server->secmech.sdeschmacsha256->shash;
244	}
245
246	rc = crypto_shash_setkey(hash, ses->auth_key.response,
247			SMB2_NTLMV2_SESSKEY_SIZE);
248	if (rc) {
249		cifs_server_dbg(VFS,
250				"%s: Could not update with response\n",
251				__func__);
252		goto out;
253	}
254
255	rc = crypto_shash_init(shash);
256	if (rc) {
257		cifs_server_dbg(VFS, "%s: Could not init sha256", __func__);
258		goto out;
259	}
260
261	/*
262	 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
263	 * data, that is, iov[0] should not contain a rfc1002 length.
264	 *
265	 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
266	 * __cifs_calc_signature().
267	 */
268	drqst = *rqst;
269	if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
270		rc = crypto_shash_update(shash, iov[0].iov_base,
271					 iov[0].iov_len);
272		if (rc) {
273			cifs_server_dbg(VFS,
274					"%s: Could not update with payload\n",
275					__func__);
276			goto out;
277		}
278		drqst.rq_iov++;
279		drqst.rq_nvec--;
280	}
281
282	rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
283	if (!rc)
284		memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
285
286out:
287	if (allocate_crypto)
288		cifs_free_hash(&hash, &sdesc);
289	if (ses)
290		cifs_put_smb_ses(ses);
291	return rc;
292}
293
294static int generate_key(struct cifs_ses *ses, struct kvec label,
295			struct kvec context, __u8 *key, unsigned int key_size)
296{
297	unsigned char zero = 0x0;
298	__u8 i[4] = {0, 0, 0, 1};
299	__u8 L128[4] = {0, 0, 0, 128};
300	__u8 L256[4] = {0, 0, 1, 0};
301	int rc = 0;
302	unsigned char prfhash[SMB2_HMACSHA256_SIZE];
303	unsigned char *hashptr = prfhash;
304	struct TCP_Server_Info *server = ses->server;
305
306	memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
307	memset(key, 0x0, key_size);
308
309	rc = smb3_crypto_shash_allocate(server);
310	if (rc) {
311		cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
312		goto smb3signkey_ret;
313	}
314
315	rc = crypto_shash_setkey(server->secmech.hmacsha256,
316		ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
317	if (rc) {
318		cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__);
319		goto smb3signkey_ret;
320	}
321
322	rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
323	if (rc) {
324		cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
325		goto smb3signkey_ret;
326	}
327
328	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
329				i, 4);
330	if (rc) {
331		cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__);
332		goto smb3signkey_ret;
333	}
334
335	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
336				label.iov_base, label.iov_len);
337	if (rc) {
338		cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__);
339		goto smb3signkey_ret;
340	}
341
342	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
343				&zero, 1);
344	if (rc) {
345		cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__);
346		goto smb3signkey_ret;
347	}
348
349	rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
350				context.iov_base, context.iov_len);
351	if (rc) {
352		cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__);
353		goto smb3signkey_ret;
354	}
355
356	if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
357		(server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
358		rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
359				L256, 4);
360	} else {
361		rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
362				L128, 4);
363	}
364	if (rc) {
365		cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__);
366		goto smb3signkey_ret;
367	}
368
369	rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
370				hashptr);
371	if (rc) {
372		cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
373		goto smb3signkey_ret;
374	}
375
376	memcpy(key, hashptr, key_size);
377
378smb3signkey_ret:
379	return rc;
380}
381
382struct derivation {
383	struct kvec label;
384	struct kvec context;
385};
386
387struct derivation_triplet {
388	struct derivation signing;
389	struct derivation encryption;
390	struct derivation decryption;
391};
392
393static int
394generate_smb3signingkey(struct cifs_ses *ses,
395			const struct derivation_triplet *ptriplet)
396{
397	int rc;
398#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
399	struct TCP_Server_Info *server = ses->server;
400#endif
401
402	/*
403	 * All channels use the same encryption/decryption keys but
404	 * they have their own signing key.
405	 *
406	 * When we generate the keys, check if it is for a new channel
407	 * (binding) in which case we only need to generate a signing
408	 * key and store it in the channel as to not overwrite the
409	 * master connection signing key stored in the session
410	 */
411
412	if (ses->binding) {
413		rc = generate_key(ses, ptriplet->signing.label,
414				  ptriplet->signing.context,
415				  cifs_ses_binding_channel(ses)->signkey,
416				  SMB3_SIGN_KEY_SIZE);
417		if (rc)
418			return rc;
419	} else {
420		rc = generate_key(ses, ptriplet->signing.label,
421				  ptriplet->signing.context,
422				  ses->smb3signingkey,
423				  SMB3_SIGN_KEY_SIZE);
424		if (rc)
425			return rc;
426
427		memcpy(ses->chans[0].signkey, ses->smb3signingkey,
428		       SMB3_SIGN_KEY_SIZE);
429
430		rc = generate_key(ses, ptriplet->encryption.label,
431				  ptriplet->encryption.context,
432				  ses->smb3encryptionkey,
433				  SMB3_ENC_DEC_KEY_SIZE);
434		rc = generate_key(ses, ptriplet->decryption.label,
435				  ptriplet->decryption.context,
436				  ses->smb3decryptionkey,
437				  SMB3_ENC_DEC_KEY_SIZE);
438		if (rc)
439			return rc;
440	}
441
442	if (rc)
443		return rc;
444
445#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
446	cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
447	/*
448	 * The session id is opaque in terms of endianness, so we can't
449	 * print it as a long long. we dump it as we got it on the wire
450	 */
451	cifs_dbg(VFS, "Session Id    %*ph\n", (int)sizeof(ses->Suid),
452			&ses->Suid);
453	cifs_dbg(VFS, "Cipher type   %d\n", server->cipher_type);
454	cifs_dbg(VFS, "Session Key   %*ph\n",
455		 SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
456	cifs_dbg(VFS, "Signing Key   %*ph\n",
457		 SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
458	if ((server->cipher_type == SMB2_ENCRYPTION_AES256_CCM) ||
459		(server->cipher_type == SMB2_ENCRYPTION_AES256_GCM)) {
460		cifs_dbg(VFS, "ServerIn Key  %*ph\n",
461				SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3encryptionkey);
462		cifs_dbg(VFS, "ServerOut Key %*ph\n",
463				SMB3_GCM256_CRYPTKEY_SIZE, ses->smb3decryptionkey);
464	} else {
465		cifs_dbg(VFS, "ServerIn Key  %*ph\n",
466				SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3encryptionkey);
467		cifs_dbg(VFS, "ServerOut Key %*ph\n",
468				SMB3_GCM128_CRYPTKEY_SIZE, ses->smb3decryptionkey);
469	}
470#endif
471	return rc;
472}
473
474int
475generate_smb30signingkey(struct cifs_ses *ses)
476
477{
478	struct derivation_triplet triplet;
479	struct derivation *d;
480
481	d = &triplet.signing;
482	d->label.iov_base = "SMB2AESCMAC";
483	d->label.iov_len = 12;
484	d->context.iov_base = "SmbSign";
485	d->context.iov_len = 8;
486
487	d = &triplet.encryption;
488	d->label.iov_base = "SMB2AESCCM";
489	d->label.iov_len = 11;
490	d->context.iov_base = "ServerIn ";
491	d->context.iov_len = 10;
492
493	d = &triplet.decryption;
494	d->label.iov_base = "SMB2AESCCM";
495	d->label.iov_len = 11;
496	d->context.iov_base = "ServerOut";
497	d->context.iov_len = 10;
498
499	return generate_smb3signingkey(ses, &triplet);
500}
501
502int
503generate_smb311signingkey(struct cifs_ses *ses)
504
505{
506	struct derivation_triplet triplet;
507	struct derivation *d;
508
509	d = &triplet.signing;
510	d->label.iov_base = "SMBSigningKey";
511	d->label.iov_len = 14;
512	d->context.iov_base = ses->preauth_sha_hash;
513	d->context.iov_len = 64;
514
515	d = &triplet.encryption;
516	d->label.iov_base = "SMBC2SCipherKey";
517	d->label.iov_len = 16;
518	d->context.iov_base = ses->preauth_sha_hash;
519	d->context.iov_len = 64;
520
521	d = &triplet.decryption;
522	d->label.iov_base = "SMBS2CCipherKey";
523	d->label.iov_len = 16;
524	d->context.iov_base = ses->preauth_sha_hash;
525	d->context.iov_len = 64;
526
527	return generate_smb3signingkey(ses, &triplet);
528}
529
530int
531smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server,
532			bool allocate_crypto)
533{
534	int rc;
535	unsigned char smb3_signature[SMB2_CMACAES_SIZE];
536	unsigned char *sigptr = smb3_signature;
537	struct kvec *iov = rqst->rq_iov;
538	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
539	struct shash_desc *shash;
540	struct crypto_shash *hash;
541	struct sdesc *sdesc = NULL;
542	struct smb_rqst drqst;
543	u8 key[SMB3_SIGN_KEY_SIZE];
544
545	rc = smb2_get_sign_key(shdr->SessionId, server, key);
546	if (rc)
547		return 0;
548
549	if (allocate_crypto) {
550		rc = cifs_alloc_hash("cmac(aes)", &hash, &sdesc);
551		if (rc)
552			return rc;
553
554		shash = &sdesc->shash;
555	} else {
556		hash = server->secmech.cmacaes;
557		shash = &server->secmech.sdesccmacaes->shash;
558	}
559
560	memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
561	memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
562
563	rc = crypto_shash_setkey(hash, key, SMB2_CMACAES_SIZE);
564	if (rc) {
565		cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
566		goto out;
567	}
568
569	/*
570	 * we already allocate sdesccmacaes when we init smb3 signing key,
571	 * so unlike smb2 case we do not have to check here if secmech are
572	 * initialized
573	 */
574	rc = crypto_shash_init(shash);
575	if (rc) {
576		cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
577		goto out;
578	}
579
580	/*
581	 * For SMB2+, __cifs_calc_signature() expects to sign only the actual
582	 * data, that is, iov[0] should not contain a rfc1002 length.
583	 *
584	 * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
585	 * __cifs_calc_signature().
586	 */
587	drqst = *rqst;
588	if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
589		rc = crypto_shash_update(shash, iov[0].iov_base,
590					 iov[0].iov_len);
591		if (rc) {
592			cifs_server_dbg(VFS, "%s: Could not update with payload\n",
593				 __func__);
594			goto out;
595		}
596		drqst.rq_iov++;
597		drqst.rq_nvec--;
598	}
599
600	rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
601	if (!rc)
602		memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
603
604out:
605	if (allocate_crypto)
606		cifs_free_hash(&hash, &sdesc);
607	return rc;
608}
609
610/* must be called with server->srv_mutex held */
611static int
612smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
613{
614	int rc = 0;
615	struct smb2_sync_hdr *shdr;
616	struct smb2_sess_setup_req *ssr;
617	bool is_binding;
618	bool is_signed;
619
620	shdr = (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
621	ssr = (struct smb2_sess_setup_req *)shdr;
622
623	is_binding = shdr->Command == SMB2_SESSION_SETUP &&
624		(ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING);
625	is_signed = shdr->Flags & SMB2_FLAGS_SIGNED;
626
627	if (!is_signed)
628		return 0;
629	if (server->tcpStatus == CifsNeedNegotiate)
630		return 0;
631	if (!is_binding && !server->session_estab) {
632		strncpy(shdr->Signature, "BSRSPYL", 8);
633		return 0;
634	}
635
636	rc = server->ops->calc_signature(rqst, server, false);
637
638	return rc;
639}
640
641int
642smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
643{
644	unsigned int rc;
645	char server_response_sig[SMB2_SIGNATURE_SIZE];
646	struct smb2_sync_hdr *shdr =
647			(struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
648
649	if ((shdr->Command == SMB2_NEGOTIATE) ||
650	    (shdr->Command == SMB2_SESSION_SETUP) ||
651	    (shdr->Command == SMB2_OPLOCK_BREAK) ||
652	    server->ignore_signature ||
653	    (!server->session_estab))
654		return 0;
655
656	/*
657	 * BB what if signatures are supposed to be on for session but
658	 * server does not send one? BB
659	 */
660
661	/* Do not need to verify session setups with signature "BSRSPYL " */
662	if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
663		cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
664			 shdr->Command);
665
666	/*
667	 * Save off the origiginal signature so we can modify the smb and check
668	 * our calculated signature against what the server sent.
669	 */
670	memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
671
672	memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
673
674	rc = server->ops->calc_signature(rqst, server, true);
675
676	if (rc)
677		return rc;
678
679	if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE)) {
680		cifs_dbg(VFS, "sign fail cmd 0x%x message id 0x%llx\n",
681			shdr->Command, shdr->MessageId);
682		return -EACCES;
683	} else
684		return 0;
685}
686
687/*
688 * Set message id for the request. Should be called after wait_for_free_request
689 * and when srv_mutex is held.
690 */
691static inline void
692smb2_seq_num_into_buf(struct TCP_Server_Info *server,
693		      struct smb2_sync_hdr *shdr)
694{
695	unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
696
697	shdr->MessageId = get_next_mid64(server);
698	/* skip message numbers according to CreditCharge field */
699	for (i = 1; i < num; i++)
700		get_next_mid(server);
701}
702
703static struct mid_q_entry *
704smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
705		     struct TCP_Server_Info *server)
706{
707	struct mid_q_entry *temp;
708	unsigned int credits = le16_to_cpu(shdr->CreditCharge);
709
710	if (server == NULL) {
711		cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
712		return NULL;
713	}
714
715	temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
716	memset(temp, 0, sizeof(struct mid_q_entry));
717	kref_init(&temp->refcount);
718	temp->mid = le64_to_cpu(shdr->MessageId);
719	temp->credits = credits > 0 ? credits : 1;
720	temp->pid = current->pid;
721	temp->command = shdr->Command; /* Always LE */
722	temp->when_alloc = jiffies;
723	temp->server = server;
724
725	/*
726	 * The default is for the mid to be synchronous, so the
727	 * default callback just wakes up the current task.
728	 */
729	get_task_struct(current);
730	temp->creator = current;
731	temp->callback = cifs_wake_up_task;
732	temp->callback_data = current;
733
734	atomic_inc(&midCount);
735	temp->mid_state = MID_REQUEST_ALLOCATED;
736	trace_smb3_cmd_enter(shdr->TreeId, shdr->SessionId,
737		le16_to_cpu(shdr->Command), temp->mid);
738	return temp;
739}
740
741static int
742smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
743		   struct smb2_sync_hdr *shdr, struct mid_q_entry **mid)
744{
745	if (server->tcpStatus == CifsExiting)
746		return -ENOENT;
747
748	if (server->tcpStatus == CifsNeedReconnect) {
749		cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
750		return -EAGAIN;
751	}
752
753	if (server->tcpStatus == CifsNeedNegotiate &&
754	   shdr->Command != SMB2_NEGOTIATE)
755		return -EAGAIN;
756
757	if (ses->status == CifsNew) {
758		if ((shdr->Command != SMB2_SESSION_SETUP) &&
759		    (shdr->Command != SMB2_NEGOTIATE))
760			return -EAGAIN;
761		/* else ok - we are setting up session */
762	}
763
764	if (ses->status == CifsExiting) {
765		if (shdr->Command != SMB2_LOGOFF)
766			return -EAGAIN;
767		/* else ok - we are shutting down the session */
768	}
769
770	*mid = smb2_mid_entry_alloc(shdr, server);
771	if (*mid == NULL)
772		return -ENOMEM;
773	spin_lock(&GlobalMid_Lock);
774	list_add_tail(&(*mid)->qhead, &server->pending_mid_q);
775	spin_unlock(&GlobalMid_Lock);
776
777	return 0;
778}
779
780int
781smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
782		   bool log_error)
783{
784	unsigned int len = mid->resp_buf_size;
785	struct kvec iov[1];
786	struct smb_rqst rqst = { .rq_iov = iov,
787				 .rq_nvec = 1 };
788
789	iov[0].iov_base = (char *)mid->resp_buf;
790	iov[0].iov_len = len;
791
792	dump_smb(mid->resp_buf, min_t(u32, 80, len));
793	/* convert the length into a more usable form */
794	if (len > 24 && server->sign && !mid->decrypted) {
795		int rc;
796
797		rc = smb2_verify_signature(&rqst, server);
798		if (rc)
799			cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
800				 rc);
801	}
802
803	return map_smb2_to_linux_error(mid->resp_buf, log_error);
804}
805
806struct mid_q_entry *
807smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server,
808		   struct smb_rqst *rqst)
809{
810	int rc;
811	struct smb2_sync_hdr *shdr =
812			(struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
813	struct mid_q_entry *mid;
814
815	smb2_seq_num_into_buf(server, shdr);
816
817	rc = smb2_get_mid_entry(ses, server, shdr, &mid);
818	if (rc) {
819		revert_current_mid_from_hdr(server, shdr);
820		return ERR_PTR(rc);
821	}
822
823	rc = smb2_sign_rqst(rqst, server);
824	if (rc) {
825		revert_current_mid_from_hdr(server, shdr);
826		cifs_delete_mid(mid);
827		return ERR_PTR(rc);
828	}
829
830	return mid;
831}
832
833struct mid_q_entry *
834smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
835{
836	int rc;
837	struct smb2_sync_hdr *shdr =
838			(struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
839	struct mid_q_entry *mid;
840
841	if (server->tcpStatus == CifsNeedNegotiate &&
842	   shdr->Command != SMB2_NEGOTIATE)
843		return ERR_PTR(-EAGAIN);
844
845	smb2_seq_num_into_buf(server, shdr);
846
847	mid = smb2_mid_entry_alloc(shdr, server);
848	if (mid == NULL) {
849		revert_current_mid_from_hdr(server, shdr);
850		return ERR_PTR(-ENOMEM);
851	}
852
853	rc = smb2_sign_rqst(rqst, server);
854	if (rc) {
855		revert_current_mid_from_hdr(server, shdr);
856		DeleteMidQEntry(mid);
857		return ERR_PTR(rc);
858	}
859
860	return mid;
861}
862
863int
864smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
865{
866	struct crypto_aead *tfm;
867
868	if (!server->secmech.ccmaesencrypt) {
869		if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
870		    (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
871			tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
872		else
873			tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
874		if (IS_ERR(tfm)) {
875			cifs_server_dbg(VFS, "%s: Failed alloc encrypt aead\n",
876				 __func__);
877			return PTR_ERR(tfm);
878		}
879		server->secmech.ccmaesencrypt = tfm;
880	}
881
882	if (!server->secmech.ccmaesdecrypt) {
883		if ((server->cipher_type == SMB2_ENCRYPTION_AES128_GCM) ||
884		    (server->cipher_type == SMB2_ENCRYPTION_AES256_GCM))
885			tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
886		else
887			tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
888		if (IS_ERR(tfm)) {
889			crypto_free_aead(server->secmech.ccmaesencrypt);
890			server->secmech.ccmaesencrypt = NULL;
891			cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
892				 __func__);
893			return PTR_ERR(tfm);
894		}
895		server->secmech.ccmaesdecrypt = tfm;
896	}
897
898	return 0;
899}