fs/cifs/smb2transport.c

   1 /*
   2  *   fs/cifs/smb2transport.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002, 2011
   5  *                 Etersoft, 2012
   6  *   Author(s): Steve French (sfrench@us.ibm.com)
   7  *              Jeremy Allison (jra@samba.org) 2006
   8  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
   9  *
  10  *   This library is free software; you can redistribute it and/or modify
  11  *   it under the terms of the GNU Lesser General Public License as published
  12  *   by the Free Software Foundation; either version 2.1 of the License, or
  13  *   (at your option) any later version.
  14  *
  15  *   This library is distributed in the hope that it will be useful,
  16  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  18  *   the GNU Lesser General Public License for more details.
  19  *
  20  *   You should have received a copy of the GNU Lesser General Public License
  21  *   along with this library; if not, write to the Free Software
  22  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24
  25 #include <linux/fs.h>
  26 #include <linux/list.h>
  27 #include <linux/wait.h>
  28 #include <linux/net.h>
  29 #include <linux/delay.h>
  30 #include <linux/uaccess.h>
  31 #include <asm/processor.h>
  32 #include <linux/mempool.h>
  33 #include <linux/highmem.h>
  34 #include <crypto/aead.h>
  35 #include "smb2pdu.h"
  36 #include "cifsglob.h"
  37 #include "cifsproto.h"
  38 #include "smb2proto.h"
  39 #include "cifs_debug.h"
  40 #include "smb2status.h"
  41 #include "smb2glob.h"
  42
  43 static int
  44 smb2_crypto_shash_allocate(struct TCP_Server_Info *server)
  45 {
  46         return cifs_alloc_hash("hmac(sha256)",
  47                                &server->secmech.hmacsha256,
  48                                &server->secmech.sdeschmacsha256);
  49 }
  50
  51 static int
  52 smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
  53 {
  54         struct cifs_secmech *p = &server->secmech;
  55         int rc;
  56
  57         rc = cifs_alloc_hash("hmac(sha256)",
  58                              &p->hmacsha256,
  59                              &p->sdeschmacsha256);
  60         if (rc)
  61                 goto err;
  62
  63         rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
  64         if (rc)
  65                 goto err;
  66
  67         return 0;
  68 err:
  69         cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
  70         return rc;
  71 }
  72
  73 int
  74 smb311_crypto_shash_allocate(struct TCP_Server_Info *server)
  75 {
  76         struct cifs_secmech *p = &server->secmech;
  77         int rc = 0;
  78
  79         rc = cifs_alloc_hash("hmac(sha256)",
  80                              &p->hmacsha256,
  81                              &p->sdeschmacsha256);
  82         if (rc)
  83                 return rc;
  84
  85         rc = cifs_alloc_hash("cmac(aes)", &p->cmacaes, &p->sdesccmacaes);
  86         if (rc)
  87                 goto err;
  88
  89         rc = cifs_alloc_hash("sha512", &p->sha512, &p->sdescsha512);
  90         if (rc)
  91                 goto err;
  92
  93         return 0;
  94
  95 err:
  96         cifs_free_hash(&p->cmacaes, &p->sdesccmacaes);
  97         cifs_free_hash(&p->hmacsha256, &p->sdeschmacsha256);
  98         return rc;
  99 }
 100
 101 static struct cifs_ses *
 102 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
 103 {
 104         struct cifs_ses *ses;
 105
 106         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 107                 if (ses->Suid != ses_id)
 108                         continue;
 109                 return ses;
 110         }
 111
 112         return NULL;
 113 }
 114
 115 struct cifs_ses *
 116 smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
 117 {
 118         struct cifs_ses *ses;
 119
 120         spin_lock(&cifs_tcp_ses_lock);
 121         ses = smb2_find_smb_ses_unlocked(server, ses_id);
 122         spin_unlock(&cifs_tcp_ses_lock);
 123
 124         return ses;
 125 }
 126
 127 static struct cifs_tcon *
 128 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32  tid)
 129 {
 130         struct cifs_tcon *tcon;
 131
 132         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 133                 if (tcon->tid != tid)
 134                         continue;
 135                 ++tcon->tc_count;
 136                 return tcon;
 137         }
 138
 139         return NULL;
 140 }
 141
 142 /*
 143  * Obtain tcon corresponding to the tid in the given
 144  * cifs_ses
 145  */
 146
 147 struct cifs_tcon *
 148 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32  tid)
 149 {
 150         struct cifs_ses *ses;
 151         struct cifs_tcon *tcon;
 152
 153         spin_lock(&cifs_tcp_ses_lock);
 154         ses = smb2_find_smb_ses_unlocked(server, ses_id);
 155         if (!ses) {
 156                 spin_unlock(&cifs_tcp_ses_lock);
 157                 return NULL;
 158         }
 159         tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
 160         spin_unlock(&cifs_tcp_ses_lock);
 161
 162         return tcon;
 163 }
 164
 165 int
 166 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 167 {
 168         int rc;
 169         unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
 170         unsigned char *sigptr = smb2_signature;
 171         struct kvec *iov = rqst->rq_iov;
 172         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
 173         struct cifs_ses *ses;
 174         struct shash_desc *shash;
 175         struct smb_rqst drqst;
 176
 177         ses = smb2_find_smb_ses(server, shdr->SessionId);
 178         if (!ses) {
 179                 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 180                 return 0;
 181         }
 182
 183         memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
 184         memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 185
 186         rc = smb2_crypto_shash_allocate(server);
 187         if (rc) {
 188                 cifs_dbg(VFS, "%s: sha256 alloc failed\n", __func__);
 189                 return rc;
 190         }
 191
 192         rc = crypto_shash_setkey(server->secmech.hmacsha256,
 193                                  ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 194         if (rc) {
 195                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 196                 return rc;
 197         }
 198
 199         shash = &server->secmech.sdeschmacsha256->shash;
 200         rc = crypto_shash_init(shash);
 201         if (rc) {
 202                 cifs_dbg(VFS, "%s: Could not init sha256", __func__);
 203                 return rc;
 204         }
 205
 206         /*
 207          * For SMB2+, __cifs_calc_signature() expects to sign only the actual
 208          * data, that is, iov[0] should not contain a rfc1002 length.
 209          *
 210          * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
 211          * __cifs_calc_signature().
 212          */
 213         drqst = *rqst;
 214         if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
 215                 rc = crypto_shash_update(shash, iov[0].iov_base,
 216                                          iov[0].iov_len);
 217                 if (rc) {
 218                         cifs_dbg(VFS, "%s: Could not update with payload\n",
 219                                  __func__);
 220                         return rc;
 221                 }
 222                 drqst.rq_iov++;
 223                 drqst.rq_nvec--;
 224         }
 225
 226         rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
 227         if (!rc)
 228                 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 229
 230         return rc;
 231 }
 232
 233 static int generate_key(struct cifs_ses *ses, struct kvec label,
 234                         struct kvec context, __u8 *key, unsigned int key_size)
 235 {
 236         unsigned char zero = 0x0;
 237         __u8 i[4] = {0, 0, 0, 1};
 238         __u8 L[4] = {0, 0, 0, 128};
 239         int rc = 0;
 240         unsigned char prfhash[SMB2_HMACSHA256_SIZE];
 241         unsigned char *hashptr = prfhash;
 242
 243         memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
 244         memset(key, 0x0, key_size);
 245
 246         rc = smb3_crypto_shash_allocate(ses->server);
 247         if (rc) {
 248                 cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
 249                 goto smb3signkey_ret;
 250         }
 251
 252         rc = crypto_shash_setkey(ses->server->secmech.hmacsha256,
 253                 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 254         if (rc) {
 255                 cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
 256                 goto smb3signkey_ret;
 257         }
 258
 259         rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash);
 260         if (rc) {
 261                 cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
 262                 goto smb3signkey_ret;
 263         }
 264
 265         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 266                                 i, 4);
 267         if (rc) {
 268                 cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
 269                 goto smb3signkey_ret;
 270         }
 271
 272         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 273                                 label.iov_base, label.iov_len);
 274         if (rc) {
 275                 cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
 276                 goto smb3signkey_ret;
 277         }
 278
 279         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 280                                 &zero, 1);
 281         if (rc) {
 282                 cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
 283                 goto smb3signkey_ret;
 284         }
 285
 286         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 287                                 context.iov_base, context.iov_len);
 288         if (rc) {
 289                 cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
 290                 goto smb3signkey_ret;
 291         }
 292
 293         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 294                                 L, 4);
 295         if (rc) {
 296                 cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
 297                 goto smb3signkey_ret;
 298         }
 299
 300         rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash,
 301                                 hashptr);
 302         if (rc) {
 303                 cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
 304                 goto smb3signkey_ret;
 305         }
 306
 307         memcpy(key, hashptr, key_size);
 308
 309 smb3signkey_ret:
 310         return rc;
 311 }
 312
 313 struct derivation {
 314         struct kvec label;
 315         struct kvec context;
 316 };
 317
 318 struct derivation_triplet {
 319         struct derivation signing;
 320         struct derivation encryption;
 321         struct derivation decryption;
 322 };
 323
 324 static int
 325 generate_smb3signingkey(struct cifs_ses *ses,
 326                         const struct derivation_triplet *ptriplet)
 327 {
 328         int rc;
 329
 330         rc = generate_key(ses, ptriplet->signing.label,
 331                           ptriplet->signing.context, ses->smb3signingkey,
 332                           SMB3_SIGN_KEY_SIZE);
 333         if (rc)
 334                 return rc;
 335
 336         rc = generate_key(ses, ptriplet->encryption.label,
 337                           ptriplet->encryption.context, ses->smb3encryptionkey,
 338                           SMB3_SIGN_KEY_SIZE);
 339         if (rc)
 340                 return rc;
 341
 342         rc = generate_key(ses, ptriplet->decryption.label,
 343                           ptriplet->decryption.context,
 344                           ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
 345
 346         if (rc)
 347                 return rc;
 348
 349 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
 350         cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
 351         /*
 352          * The session id is opaque in terms of endianness, so we can't
 353          * print it as a long long. we dump it as we got it on the wire
 354          */
 355         cifs_dbg(VFS, "Session Id    %*ph\n", (int)sizeof(ses->Suid),
 356                         &ses->Suid);
 357         cifs_dbg(VFS, "Session Key   %*ph\n",
 358                  SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
 359         cifs_dbg(VFS, "Signing Key   %*ph\n",
 360                  SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
 361         cifs_dbg(VFS, "ServerIn Key  %*ph\n",
 362                  SMB3_SIGN_KEY_SIZE, ses->smb3encryptionkey);
 363         cifs_dbg(VFS, "ServerOut Key %*ph\n",
 364                  SMB3_SIGN_KEY_SIZE, ses->smb3decryptionkey);
 365 #endif
 366         return rc;
 367 }
 368
 369 int
 370 generate_smb30signingkey(struct cifs_ses *ses)
 371
 372 {
 373         struct derivation_triplet triplet;
 374         struct derivation *d;
 375
 376         d = &triplet.signing;
 377         d->label.iov_base = "SMB2AESCMAC";
 378         d->label.iov_len = 12;
 379         d->context.iov_base = "SmbSign";
 380         d->context.iov_len = 8;
 381
 382         d = &triplet.encryption;
 383         d->label.iov_base = "SMB2AESCCM";
 384         d->label.iov_len = 11;
 385         d->context.iov_base = "ServerIn ";
 386         d->context.iov_len = 10;
 387
 388         d = &triplet.decryption;
 389         d->label.iov_base = "SMB2AESCCM";
 390         d->label.iov_len = 11;
 391         d->context.iov_base = "ServerOut";
 392         d->context.iov_len = 10;
 393
 394         return generate_smb3signingkey(ses, &triplet);
 395 }
 396
 397 int
 398 generate_smb311signingkey(struct cifs_ses *ses)
 399
 400 {
 401         struct derivation_triplet triplet;
 402         struct derivation *d;
 403
 404         d = &triplet.signing;
 405         d->label.iov_base = "SMBSigningKey";
 406         d->label.iov_len = 14;
 407         d->context.iov_base = ses->preauth_sha_hash;
 408         d->context.iov_len = 64;
 409
 410         d = &triplet.encryption;
 411         d->label.iov_base = "SMBC2SCipherKey";
 412         d->label.iov_len = 16;
 413         d->context.iov_base = ses->preauth_sha_hash;
 414         d->context.iov_len = 64;
 415
 416         d = &triplet.decryption;
 417         d->label.iov_base = "SMBS2CCipherKey";
 418         d->label.iov_len = 16;
 419         d->context.iov_base = ses->preauth_sha_hash;
 420         d->context.iov_len = 64;
 421
 422         return generate_smb3signingkey(ses, &triplet);
 423 }
 424
 425 int
 426 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 427 {
 428         int rc;
 429         unsigned char smb3_signature[SMB2_CMACAES_SIZE];
 430         unsigned char *sigptr = smb3_signature;
 431         struct kvec *iov = rqst->rq_iov;
 432         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
 433         struct cifs_ses *ses;
 434         struct shash_desc *shash = &server->secmech.sdesccmacaes->shash;
 435         struct smb_rqst drqst;
 436
 437         ses = smb2_find_smb_ses(server, shdr->SessionId);
 438         if (!ses) {
 439                 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 440                 return 0;
 441         }
 442
 443         memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
 444         memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 445
 446         rc = crypto_shash_setkey(server->secmech.cmacaes,
 447                                  ses->smb3signingkey, SMB2_CMACAES_SIZE);
 448         if (rc) {
 449                 cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
 450                 return rc;
 451         }
 452
 453         /*
 454          * we already allocate sdesccmacaes when we init smb3 signing key,
 455          * so unlike smb2 case we do not have to check here if secmech are
 456          * initialized
 457          */
 458         rc = crypto_shash_init(shash);
 459         if (rc) {
 460                 cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
 461                 return rc;
 462         }
 463
 464         /*
 465          * For SMB2+, __cifs_calc_signature() expects to sign only the actual
 466          * data, that is, iov[0] should not contain a rfc1002 length.
 467          *
 468          * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
 469          * __cifs_calc_signature().
 470          */
 471         drqst = *rqst;
 472         if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
 473                 rc = crypto_shash_update(shash, iov[0].iov_base,
 474                                          iov[0].iov_len);
 475                 if (rc) {
 476                         cifs_dbg(VFS, "%s: Could not update with payload\n",
 477                                  __func__);
 478                         return rc;
 479                 }
 480                 drqst.rq_iov++;
 481                 drqst.rq_nvec--;
 482         }
 483
 484         rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
 485         if (!rc)
 486                 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 487
 488         return rc;
 489 }
 490
 491 /* must be called with server->srv_mutex held */
 492 static int
 493 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 494 {
 495         int rc = 0;
 496         struct smb2_sync_hdr *shdr =
 497                         (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 498
 499         if (!(shdr->Flags & SMB2_FLAGS_SIGNED) ||
 500             server->tcpStatus == CifsNeedNegotiate)
 501                 return rc;
 502
 503         if (!server->session_estab) {
 504                 strncpy(shdr->Signature, "BSRSPYL", 8);
 505                 return rc;
 506         }
 507
 508         rc = server->ops->calc_signature(rqst, server);
 509
 510         return rc;
 511 }
 512
 513 int
 514 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 515 {
 516         unsigned int rc;
 517         char server_response_sig[16];
 518         struct smb2_sync_hdr *shdr =
 519                         (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 520
 521         if ((shdr->Command == SMB2_NEGOTIATE) ||
 522             (shdr->Command == SMB2_SESSION_SETUP) ||
 523             (shdr->Command == SMB2_OPLOCK_BREAK) ||
 524             (!server->session_estab))
 525                 return 0;
 526
 527         /*
 528          * BB what if signatures are supposed to be on for session but
 529          * server does not send one? BB
 530          */
 531
 532         /* Do not need to verify session setups with signature "BSRSPYL " */
 533         if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
 534                 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 535                          shdr->Command);
 536
 537         /*
 538          * Save off the origiginal signature so we can modify the smb and check
 539          * our calculated signature against what the server sent.
 540          */
 541         memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
 542
 543         memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
 544
 545         mutex_lock(&server->srv_mutex);
 546         rc = server->ops->calc_signature(rqst, server);
 547         mutex_unlock(&server->srv_mutex);
 548
 549         if (rc)
 550                 return rc;
 551
 552         if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE))
 553                 return -EACCES;
 554         else
 555                 return 0;
 556 }
 557
 558 /*
 559  * Set message id for the request. Should be called after wait_for_free_request
 560  * and when srv_mutex is held.
 561  */
 562 static inline void
 563 smb2_seq_num_into_buf(struct TCP_Server_Info *server,
 564                       struct smb2_sync_hdr *shdr)
 565 {
 566         unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
 567
 568         shdr->MessageId = get_next_mid64(server);
 569         /* skip message numbers according to CreditCharge field */
 570         for (i = 1; i < num; i++)
 571                 get_next_mid(server);
 572 }
 573
 574 static struct mid_q_entry *
 575 smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
 576                      struct TCP_Server_Info *server)
 577 {
 578         struct mid_q_entry *temp;
 579         unsigned int credits = le16_to_cpu(shdr->CreditCharge);
 580
 581         if (server == NULL) {
 582                 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
 583                 return NULL;
 584         }
 585
 586         temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
 587         memset(temp, 0, sizeof(struct mid_q_entry));
 588         kref_init(&temp->refcount);
 589         temp->mid = le64_to_cpu(shdr->MessageId);
 590         temp->credits = credits > 0 ? credits : 1;
 591         temp->pid = current->pid;
 592         temp->command = shdr->Command; /* Always LE */
 593         temp->when_alloc = jiffies;
 594         temp->server = server;
 595
 596         /*
 597          * The default is for the mid to be synchronous, so the
 598          * default callback just wakes up the current task.
 599          */
 600         temp->callback = cifs_wake_up_task;
 601         temp->callback_data = current;
 602
 603         atomic_inc(&midCount);
 604         temp->mid_state = MID_REQUEST_ALLOCATED;
 605         trace_smb3_cmd_enter(shdr->TreeId, shdr->SessionId,
 606                 le16_to_cpu(shdr->Command), temp->mid);
 607         return temp;
 608 }
 609
 610 static int
 611 smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_sync_hdr *shdr,
 612                    struct mid_q_entry **mid)
 613 {
 614         if (ses->server->tcpStatus == CifsExiting)
 615                 return -ENOENT;
 616
 617         if (ses->server->tcpStatus == CifsNeedReconnect) {
 618                 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
 619                 return -EAGAIN;
 620         }
 621
 622         if (ses->server->tcpStatus == CifsNeedNegotiate &&
 623            shdr->Command != SMB2_NEGOTIATE)
 624                 return -EAGAIN;
 625
 626         if (ses->status == CifsNew) {
 627                 if ((shdr->Command != SMB2_SESSION_SETUP) &&
 628                     (shdr->Command != SMB2_NEGOTIATE))
 629                         return -EAGAIN;
 630                 /* else ok - we are setting up session */
 631         }
 632
 633         if (ses->status == CifsExiting) {
 634                 if (shdr->Command != SMB2_LOGOFF)
 635                         return -EAGAIN;
 636                 /* else ok - we are shutting down the session */
 637         }
 638
 639         *mid = smb2_mid_entry_alloc(shdr, ses->server);
 640         if (*mid == NULL)
 641                 return -ENOMEM;
 642         spin_lock(&GlobalMid_Lock);
 643         list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
 644         spin_unlock(&GlobalMid_Lock);
 645
 646         return 0;
 647 }
 648
 649 int
 650 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 651                    bool log_error)
 652 {
 653         unsigned int len = mid->resp_buf_size;
 654         struct kvec iov[1];
 655         struct smb_rqst rqst = { .rq_iov = iov,
 656                                  .rq_nvec = 1 };
 657
 658         iov[0].iov_base = (char *)mid->resp_buf;
 659         iov[0].iov_len = len;
 660
 661         dump_smb(mid->resp_buf, min_t(u32, 80, len));
 662         /* convert the length into a more usable form */
 663         if (len > 24 && server->sign && !mid->decrypted) {
 664                 int rc;
 665
 666                 rc = smb2_verify_signature(&rqst, server);
 667                 if (rc)
 668                         cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
 669                                  rc);
 670         }
 671
 672         return map_smb2_to_linux_error(mid->resp_buf, log_error);
 673 }
 674
 675 struct mid_q_entry *
 676 smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 677 {
 678         int rc;
 679         struct smb2_sync_hdr *shdr =
 680                         (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 681         struct mid_q_entry *mid;
 682
 683         smb2_seq_num_into_buf(ses->server, shdr);
 684
 685         rc = smb2_get_mid_entry(ses, shdr, &mid);
 686         if (rc) {
 687                 revert_current_mid_from_hdr(ses->server, shdr);
 688                 return ERR_PTR(rc);
 689         }
 690
 691         rc = smb2_sign_rqst(rqst, ses->server);
 692         if (rc) {
 693                 revert_current_mid_from_hdr(ses->server, shdr);
 694                 cifs_delete_mid(mid);
 695                 return ERR_PTR(rc);
 696         }
 697
 698         return mid;
 699 }
 700
 701 struct mid_q_entry *
 702 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 703 {
 704         int rc;
 705         struct smb2_sync_hdr *shdr =
 706                         (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 707         struct mid_q_entry *mid;
 708
 709         if (server->tcpStatus == CifsNeedNegotiate &&
 710            shdr->Command != SMB2_NEGOTIATE)
 711                 return ERR_PTR(-EAGAIN);
 712
 713         smb2_seq_num_into_buf(server, shdr);
 714
 715         mid = smb2_mid_entry_alloc(shdr, server);
 716         if (mid == NULL) {
 717                 revert_current_mid_from_hdr(server, shdr);
 718                 return ERR_PTR(-ENOMEM);
 719         }
 720
 721         rc = smb2_sign_rqst(rqst, server);
 722         if (rc) {
 723                 revert_current_mid_from_hdr(server, shdr);
 724                 DeleteMidQEntry(mid);
 725                 return ERR_PTR(rc);
 726         }
 727
 728         return mid;
 729 }
 730
 731 int
 732 smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
 733 {
 734         struct crypto_aead *tfm;
 735
 736         if (!server->secmech.ccmaesencrypt) {
 737                 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
 738                 if (IS_ERR(tfm)) {
 739                         cifs_dbg(VFS, "%s: Failed to alloc encrypt aead\n",
 740                                  __func__);
 741                         return PTR_ERR(tfm);
 742                 }
 743                 server->secmech.ccmaesencrypt = tfm;
 744         }
 745
 746         if (!server->secmech.ccmaesdecrypt) {
 747                 tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
 748                 if (IS_ERR(tfm)) {
 749                         crypto_free_aead(server->secmech.ccmaesencrypt);
 750                         server->secmech.ccmaesencrypt = NULL;
 751                         cifs_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
 752                                  __func__);
 753                         return PTR_ERR(tfm);
 754                 }
 755                 server->secmech.ccmaesdecrypt = tfm;
 756         }
 757
 758         return 0;
 759 }