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 "smb2pdu.h"
  35 #include "cifsglob.h"
  36 #include "cifsproto.h"
  37 #include "smb2proto.h"
  38 #include "cifs_debug.h"
  39 #include "smb2status.h"
  40 #include "smb2glob.h"
  41
  42 static int
  43 smb2_crypto_shash_allocate(struct TCP_Server_Info *server)
  44 {
  45         int rc;
  46         unsigned int size;
  47
  48         if (server->secmech.sdeschmacsha256 != NULL)
  49                 return 0; /* already allocated */
  50
  51         server->secmech.hmacsha256 = crypto_alloc_shash("hmac(sha256)", 0, 0);
  52         if (IS_ERR(server->secmech.hmacsha256)) {
  53                 cifs_dbg(VFS, "could not allocate crypto hmacsha256\n");
  54                 rc = PTR_ERR(server->secmech.hmacsha256);
  55                 server->secmech.hmacsha256 = NULL;
  56                 return rc;
  57         }
  58
  59         size = sizeof(struct shash_desc) +
  60                         crypto_shash_descsize(server->secmech.hmacsha256);
  61         server->secmech.sdeschmacsha256 = kmalloc(size, GFP_KERNEL);
  62         if (!server->secmech.sdeschmacsha256) {
  63                 crypto_free_shash(server->secmech.hmacsha256);
  64                 server->secmech.hmacsha256 = NULL;
  65                 return -ENOMEM;
  66         }
  67         server->secmech.sdeschmacsha256->shash.tfm = server->secmech.hmacsha256;
  68         server->secmech.sdeschmacsha256->shash.flags = 0x0;
  69
  70         return 0;
  71 }
  72
  73 static int
  74 smb3_crypto_shash_allocate(struct TCP_Server_Info *server)
  75 {
  76         unsigned int size;
  77         int rc;
  78
  79         if (server->secmech.sdesccmacaes != NULL)
  80                 return 0;  /* already allocated */
  81
  82         rc = smb2_crypto_shash_allocate(server);
  83         if (rc)
  84                 return rc;
  85
  86         server->secmech.cmacaes = crypto_alloc_shash("cmac(aes)", 0, 0);
  87         if (IS_ERR(server->secmech.cmacaes)) {
  88                 cifs_dbg(VFS, "could not allocate crypto cmac-aes");
  89                 kfree(server->secmech.sdeschmacsha256);
  90                 server->secmech.sdeschmacsha256 = NULL;
  91                 crypto_free_shash(server->secmech.hmacsha256);
  92                 server->secmech.hmacsha256 = NULL;
  93                 rc = PTR_ERR(server->secmech.cmacaes);
  94                 server->secmech.cmacaes = NULL;
  95                 return rc;
  96         }
  97
  98         size = sizeof(struct shash_desc) +
  99                         crypto_shash_descsize(server->secmech.cmacaes);
 100         server->secmech.sdesccmacaes = kmalloc(size, GFP_KERNEL);
 101         if (!server->secmech.sdesccmacaes) {
 102                 cifs_dbg(VFS, "%s: Can't alloc cmacaes\n", __func__);
 103                 kfree(server->secmech.sdeschmacsha256);
 104                 server->secmech.sdeschmacsha256 = NULL;
 105                 crypto_free_shash(server->secmech.hmacsha256);
 106                 crypto_free_shash(server->secmech.cmacaes);
 107                 server->secmech.hmacsha256 = NULL;
 108                 server->secmech.cmacaes = NULL;
 109                 return -ENOMEM;
 110         }
 111         server->secmech.sdesccmacaes->shash.tfm = server->secmech.cmacaes;
 112         server->secmech.sdesccmacaes->shash.flags = 0x0;
 113
 114         return 0;
 115 }
 116
 117 static struct cifs_ses *
 118 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
 119 {
 120         struct cifs_ses *ses;
 121
 122         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 123                 if (ses->Suid != ses_id)
 124                         continue;
 125                 return ses;
 126         }
 127
 128         return NULL;
 129 }
 130
 131 struct cifs_ses *
 132 smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
 133 {
 134         struct cifs_ses *ses;
 135
 136         spin_lock(&cifs_tcp_ses_lock);
 137         ses = smb2_find_smb_ses_unlocked(server, ses_id);
 138         spin_unlock(&cifs_tcp_ses_lock);
 139
 140         return ses;
 141 }
 142
 143 static struct cifs_tcon *
 144 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32  tid)
 145 {
 146         struct cifs_tcon *tcon;
 147
 148         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 149                 if (tcon->tid != tid)
 150                         continue;
 151                 ++tcon->tc_count;
 152                 return tcon;
 153         }
 154
 155         return NULL;
 156 }
 157
 158 /*
 159  * Obtain tcon corresponding to the tid in the given
 160  * cifs_ses
 161  */
 162
 163 struct cifs_tcon *
 164 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32 tid)
 165 {
 166         struct cifs_ses *ses;
 167         struct cifs_tcon *tcon;
 168
 169         spin_lock(&cifs_tcp_ses_lock);
 170         ses = smb2_find_smb_ses_unlocked(server, ses_id);
 171         if (!ses) {
 172                 spin_unlock(&cifs_tcp_ses_lock);
 173                 return NULL;
 174         }
 175         tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
 176         spin_unlock(&cifs_tcp_ses_lock);
 177
 178         return tcon;
 179 }
 180
 181 int
 182 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 183 {
 184         int i, rc;
 185         unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
 186         unsigned char *sigptr = smb2_signature;
 187         struct kvec *iov = rqst->rq_iov;
 188         int n_vec = rqst->rq_nvec;
 189         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 190         struct cifs_ses *ses;
 191
 192         ses = smb2_find_smb_ses(server, smb2_pdu->SessionId);
 193         if (!ses) {
 194                 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 195                 return 0;
 196         }
 197
 198         memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
 199         memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 200
 201         rc = smb2_crypto_shash_allocate(server);
 202         if (rc) {
 203                 cifs_dbg(VFS, "%s: shah256 alloc failed\n", __func__);
 204                 return rc;
 205         }
 206
 207         rc = crypto_shash_setkey(server->secmech.hmacsha256,
 208                 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 209         if (rc) {
 210                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 211                 return rc;
 212         }
 213
 214         rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
 215         if (rc) {
 216                 cifs_dbg(VFS, "%s: Could not init sha256", __func__);
 217                 return rc;
 218         }
 219
 220         for (i = 0; i < n_vec; i++) {
 221                 if (iov[i].iov_len == 0)
 222                         continue;
 223                 if (iov[i].iov_base == NULL) {
 224                         cifs_dbg(VFS, "null iovec entry\n");
 225                         return -EIO;
 226                 }
 227                 /*
 228                  * The first entry includes a length field (which does not get
 229                  * signed that occupies the first 4 bytes before the header).
 230                  */
 231                 if (i == 0) {
 232                         if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
 233                                 break; /* nothing to sign or corrupt header */
 234                         rc =
 235                         crypto_shash_update(
 236                                 &server->secmech.sdeschmacsha256->shash,
 237                                 iov[i].iov_base + 4, iov[i].iov_len - 4);
 238                 } else {
 239                         rc =
 240                         crypto_shash_update(
 241                                 &server->secmech.sdeschmacsha256->shash,
 242                                 iov[i].iov_base, iov[i].iov_len);
 243                 }
 244                 if (rc) {
 245                         cifs_dbg(VFS, "%s: Could not update with payload\n",
 246                                  __func__);
 247                         return rc;
 248                 }
 249         }
 250
 251         /* now hash over the rq_pages array */
 252         for (i = 0; i < rqst->rq_npages; i++) {
 253                 struct kvec p_iov;
 254
 255                 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
 256                 crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 257                                         p_iov.iov_base, p_iov.iov_len);
 258                 kunmap(rqst->rq_pages[i]);
 259         }
 260
 261         rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
 262                                 sigptr);
 263         if (rc)
 264                 cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
 265
 266         memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 267
 268         return rc;
 269 }
 270
 271 int
 272 generate_smb3signingkey(struct cifs_ses *ses)
 273 {
 274         unsigned char zero = 0x0;
 275         __u8 i[4] = {0, 0, 0, 1};
 276         __u8 L[4] = {0, 0, 0, 128};
 277         int rc = 0;
 278         unsigned char prfhash[SMB2_HMACSHA256_SIZE];
 279         unsigned char *hashptr = prfhash;
 280
 281         memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
 282         memset(ses->smb3signingkey, 0x0, SMB3_SIGNKEY_SIZE);
 283
 284         rc = smb3_crypto_shash_allocate(ses->server);
 285         if (rc) {
 286                 cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
 287                 goto smb3signkey_ret;
 288         }
 289
 290         rc = crypto_shash_setkey(ses->server->secmech.hmacsha256,
 291                 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 292         if (rc) {
 293                 cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
 294                 goto smb3signkey_ret;
 295         }
 296
 297         rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash);
 298         if (rc) {
 299                 cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
 300                 goto smb3signkey_ret;
 301         }
 302
 303         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 304                                 i, 4);
 305         if (rc) {
 306                 cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
 307                 goto smb3signkey_ret;
 308         }
 309
 310         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 311                                 "SMB2AESCMAC", 12);
 312         if (rc) {
 313                 cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
 314                 goto smb3signkey_ret;
 315         }
 316
 317         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 318                                 &zero, 1);
 319         if (rc) {
 320                 cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
 321                 goto smb3signkey_ret;
 322         }
 323
 324         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 325                                 "SmbSign", 8);
 326         if (rc) {
 327                 cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
 328                 goto smb3signkey_ret;
 329         }
 330
 331         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 332                                 L, 4);
 333         if (rc) {
 334                 cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
 335                 goto smb3signkey_ret;
 336         }
 337
 338         rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash,
 339                                 hashptr);
 340         if (rc) {
 341                 cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
 342                 goto smb3signkey_ret;
 343         }
 344
 345         memcpy(ses->smb3signingkey, hashptr, SMB3_SIGNKEY_SIZE);
 346
 347 smb3signkey_ret:
 348         return rc;
 349 }
 350
 351 int
 352 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 353 {
 354         int i;
 355         int rc = 0;
 356         unsigned char smb3_signature[SMB2_CMACAES_SIZE];
 357         unsigned char *sigptr = smb3_signature;
 358         struct kvec *iov = rqst->rq_iov;
 359         int n_vec = rqst->rq_nvec;
 360         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 361         struct cifs_ses *ses;
 362
 363         ses = smb2_find_smb_ses(server, smb2_pdu->SessionId);
 364         if (!ses) {
 365                 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 366                 return 0;
 367         }
 368
 369         memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
 370         memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 371
 372         rc = crypto_shash_setkey(server->secmech.cmacaes,
 373                 ses->smb3signingkey, SMB2_CMACAES_SIZE);
 374
 375         if (rc) {
 376                 cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
 377                 return rc;
 378         }
 379
 380         /*
 381          * we already allocate sdesccmacaes when we init smb3 signing key,
 382          * so unlike smb2 case we do not have to check here if secmech are
 383          * initialized
 384          */
 385         rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
 386         if (rc) {
 387                 cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
 388                 return rc;
 389         }
 390
 391         for (i = 0; i < n_vec; i++) {
 392                 if (iov[i].iov_len == 0)
 393                         continue;
 394                 if (iov[i].iov_base == NULL) {
 395                         cifs_dbg(VFS, "null iovec entry");
 396                         return -EIO;
 397                 }
 398                 /*
 399                  * The first entry includes a length field (which does not get
 400                  * signed that occupies the first 4 bytes before the header).
 401                  */
 402                 if (i == 0) {
 403                         if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
 404                                 break; /* nothing to sign or corrupt header */
 405                         rc =
 406                         crypto_shash_update(
 407                                 &server->secmech.sdesccmacaes->shash,
 408                                 iov[i].iov_base + 4, iov[i].iov_len - 4);
 409                 } else {
 410                         rc =
 411                         crypto_shash_update(
 412                                 &server->secmech.sdesccmacaes->shash,
 413                                 iov[i].iov_base, iov[i].iov_len);
 414                 }
 415                 if (rc) {
 416                         cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
 417                                                         __func__);
 418                         return rc;
 419                 }
 420         }
 421
 422         /* now hash over the rq_pages array */
 423         for (i = 0; i < rqst->rq_npages; i++) {
 424                 struct kvec p_iov;
 425
 426                 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
 427                 crypto_shash_update(&server->secmech.sdesccmacaes->shash,
 428                                         p_iov.iov_base, p_iov.iov_len);
 429                 kunmap(rqst->rq_pages[i]);
 430         }
 431
 432         rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
 433                                                 sigptr);
 434         if (rc)
 435                 cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);
 436
 437         memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 438
 439         return rc;
 440 }
 441
 442 /* must be called with server->srv_mutex held */
 443 static int
 444 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 445 {
 446         int rc = 0;
 447         struct smb2_hdr *smb2_pdu = rqst->rq_iov[0].iov_base;
 448
 449         if (!(smb2_pdu->Flags & SMB2_FLAGS_SIGNED) ||
 450             server->tcpStatus == CifsNeedNegotiate)
 451                 return rc;
 452
 453         if (!server->session_estab) {
 454                 strncpy(smb2_pdu->Signature, "BSRSPYL", 8);
 455                 return rc;
 456         }
 457
 458         rc = server->ops->calc_signature(rqst, server);
 459
 460         return rc;
 461 }
 462
 463 int
 464 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 465 {
 466         unsigned int rc;
 467         char server_response_sig[16];
 468         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 469
 470         if ((smb2_pdu->Command == SMB2_NEGOTIATE) ||
 471             (smb2_pdu->Command == SMB2_SESSION_SETUP) ||
 472             (smb2_pdu->Command == SMB2_OPLOCK_BREAK) ||
 473             (!server->session_estab))
 474                 return 0;
 475
 476         /*
 477          * BB what if signatures are supposed to be on for session but
 478          * server does not send one? BB
 479          */
 480
 481         /* Do not need to verify session setups with signature "BSRSPYL " */
 482         if (memcmp(smb2_pdu->Signature, "BSRSPYL ", 8) == 0)
 483                 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 484                          smb2_pdu->Command);
 485
 486         /*
 487          * Save off the origiginal signature so we can modify the smb and check
 488          * our calculated signature against what the server sent.
 489          */
 490         memcpy(server_response_sig, smb2_pdu->Signature, SMB2_SIGNATURE_SIZE);
 491
 492         memset(smb2_pdu->Signature, 0, SMB2_SIGNATURE_SIZE);
 493
 494         mutex_lock(&server->srv_mutex);
 495         rc = server->ops->calc_signature(rqst, server);
 496         mutex_unlock(&server->srv_mutex);
 497
 498         if (rc)
 499                 return rc;
 500
 501         if (memcmp(server_response_sig, smb2_pdu->Signature,
 502                    SMB2_SIGNATURE_SIZE))
 503                 return -EACCES;
 504         else
 505                 return 0;
 506 }
 507
 508 /*
 509  * Set message id for the request. Should be called after wait_for_free_request
 510  * and when srv_mutex is held.
 511  */
 512 static inline void
 513 smb2_seq_num_into_buf(struct TCP_Server_Info *server, struct smb2_hdr *hdr)
 514 {
 515         unsigned int i, num = le16_to_cpu(hdr->CreditCharge);
 516
 517         hdr->MessageId = get_next_mid64(server);
 518         /* skip message numbers according to CreditCharge field */
 519         for (i = 1; i < num; i++)
 520                 get_next_mid(server);
 521 }
 522
 523 static struct mid_q_entry *
 524 smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
 525                      struct TCP_Server_Info *server)
 526 {
 527         struct mid_q_entry *temp;
 528
 529         if (server == NULL) {
 530                 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
 531                 return NULL;
 532         }
 533
 534         temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
 535         if (temp == NULL)
 536                 return temp;
 537         else {
 538                 memset(temp, 0, sizeof(struct mid_q_entry));
 539                 temp->mid = le64_to_cpu(smb_buffer->MessageId);
 540                 temp->pid = current->pid;
 541                 temp->command = smb_buffer->Command;    /* Always LE */
 542                 temp->when_alloc = jiffies;
 543                 temp->server = server;
 544
 545                 /*
 546                  * The default is for the mid to be synchronous, so the
 547                  * default callback just wakes up the current task.
 548                  */
 549                 temp->callback = cifs_wake_up_task;
 550                 temp->callback_data = current;
 551         }
 552
 553         atomic_inc(&midCount);
 554         temp->mid_state = MID_REQUEST_ALLOCATED;
 555         return temp;
 556 }
 557
 558 static int
 559 smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_hdr *buf,
 560                    struct mid_q_entry **mid)
 561 {
 562         if (ses->server->tcpStatus == CifsExiting)
 563                 return -ENOENT;
 564
 565         if (ses->server->tcpStatus == CifsNeedReconnect) {
 566                 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
 567                 return -EAGAIN;
 568         }
 569
 570         if (ses->status == CifsNew) {
 571                 if ((buf->Command != SMB2_SESSION_SETUP) &&
 572                     (buf->Command != SMB2_NEGOTIATE))
 573                         return -EAGAIN;
 574                 /* else ok - we are setting up session */
 575         }
 576
 577         if (ses->status == CifsExiting) {
 578                 if (buf->Command != SMB2_LOGOFF)
 579                         return -EAGAIN;
 580                 /* else ok - we are shutting down the session */
 581         }
 582
 583         *mid = smb2_mid_entry_alloc(buf, ses->server);
 584         if (*mid == NULL)
 585                 return -ENOMEM;
 586         spin_lock(&GlobalMid_Lock);
 587         list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
 588         spin_unlock(&GlobalMid_Lock);
 589         return 0;
 590 }
 591
 592 int
 593 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 594                    bool log_error)
 595 {
 596         unsigned int len = get_rfc1002_length(mid->resp_buf);
 597         struct kvec iov;
 598         struct smb_rqst rqst = { .rq_iov = &iov,
 599                                  .rq_nvec = 1 };
 600
 601         iov.iov_base = (char *)mid->resp_buf;
 602         iov.iov_len = get_rfc1002_length(mid->resp_buf) + 4;
 603
 604         dump_smb(mid->resp_buf, min_t(u32, 80, len));
 605         /* convert the length into a more usable form */
 606         if (len > 24 && server->sign) {
 607                 int rc;
 608
 609                 rc = smb2_verify_signature(&rqst, server);
 610                 if (rc)
 611                         cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
 612                                  rc);
 613         }
 614
 615         return map_smb2_to_linux_error(mid->resp_buf, log_error);
 616 }
 617
 618 struct mid_q_entry *
 619 smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 620 {
 621         int rc;
 622         struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 623         struct mid_q_entry *mid;
 624
 625         smb2_seq_num_into_buf(ses->server, hdr);
 626
 627         rc = smb2_get_mid_entry(ses, hdr, &mid);
 628         if (rc)
 629                 return ERR_PTR(rc);
 630         rc = smb2_sign_rqst(rqst, ses->server);
 631         if (rc) {
 632                 cifs_delete_mid(mid);
 633                 return ERR_PTR(rc);
 634         }
 635         return mid;
 636 }
 637
 638 struct mid_q_entry *
 639 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 640 {
 641         int rc;
 642         struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 643         struct mid_q_entry *mid;
 644
 645         smb2_seq_num_into_buf(server, hdr);
 646
 647         mid = smb2_mid_entry_alloc(hdr, server);
 648         if (mid == NULL)
 649                 return ERR_PTR(-ENOMEM);
 650
 651         rc = smb2_sign_rqst(rqst, server);
 652         if (rc) {
 653                 DeleteMidQEntry(mid);
 654                 return ERR_PTR(rc);
 655         }
 656
 657         return mid;
 658 }