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(struct smb2_hdr *smb2hdr, struct TCP_Server_Info *server)
 119 {
 120         struct cifs_ses *ses;
 121
 122         spin_lock(&cifs_tcp_ses_lock);
 123         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 124                 if (ses->Suid != smb2hdr->SessionId)
 125                         continue;
 126                 spin_unlock(&cifs_tcp_ses_lock);
 127                 return ses;
 128         }
 129         spin_unlock(&cifs_tcp_ses_lock);
 130
 131         return NULL;
 132 }
 133
 134
 135 int
 136 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 137 {
 138         int i, rc;
 139         unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
 140         unsigned char *sigptr = smb2_signature;
 141         struct kvec *iov = rqst->rq_iov;
 142         int n_vec = rqst->rq_nvec;
 143         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 144         struct cifs_ses *ses;
 145
 146         ses = smb2_find_smb_ses(smb2_pdu, server);
 147         if (!ses) {
 148                 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 149                 return 0;
 150         }
 151
 152         memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
 153         memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 154
 155         rc = smb2_crypto_shash_allocate(server);
 156         if (rc) {
 157                 cifs_dbg(VFS, "%s: shah256 alloc failed\n", __func__);
 158                 return rc;
 159         }
 160
 161         rc = crypto_shash_setkey(server->secmech.hmacsha256,
 162                 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 163         if (rc) {
 164                 cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
 165                 return rc;
 166         }
 167
 168         rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
 169         if (rc) {
 170                 cifs_dbg(VFS, "%s: Could not init sha256", __func__);
 171                 return rc;
 172         }
 173
 174         for (i = 0; i < n_vec; i++) {
 175                 if (iov[i].iov_len == 0)
 176                         continue;
 177                 if (iov[i].iov_base == NULL) {
 178                         cifs_dbg(VFS, "null iovec entry\n");
 179                         return -EIO;
 180                 }
 181                 /*
 182                  * The first entry includes a length field (which does not get
 183                  * signed that occupies the first 4 bytes before the header).
 184                  */
 185                 if (i == 0) {
 186                         if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
 187                                 break; /* nothing to sign or corrupt header */
 188                         rc =
 189                         crypto_shash_update(
 190                                 &server->secmech.sdeschmacsha256->shash,
 191                                 iov[i].iov_base + 4, iov[i].iov_len - 4);
 192                 } else {
 193                         rc =
 194                         crypto_shash_update(
 195                                 &server->secmech.sdeschmacsha256->shash,
 196                                 iov[i].iov_base, iov[i].iov_len);
 197                 }
 198                 if (rc) {
 199                         cifs_dbg(VFS, "%s: Could not update with payload\n",
 200                                  __func__);
 201                         return rc;
 202                 }
 203         }
 204
 205         /* now hash over the rq_pages array */
 206         for (i = 0; i < rqst->rq_npages; i++) {
 207                 struct kvec p_iov;
 208
 209                 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
 210                 crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 211                                         p_iov.iov_base, p_iov.iov_len);
 212                 kunmap(rqst->rq_pages[i]);
 213         }
 214
 215         rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
 216                                 sigptr);
 217         if (rc)
 218                 cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
 219
 220         memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 221
 222         return rc;
 223 }
 224
 225 static int generate_key(struct cifs_ses *ses, struct kvec label,
 226                         struct kvec context, __u8 *key, unsigned int key_size)
 227 {
 228         unsigned char zero = 0x0;
 229         __u8 i[4] = {0, 0, 0, 1};
 230         __u8 L[4] = {0, 0, 0, 128};
 231         int rc = 0;
 232         unsigned char prfhash[SMB2_HMACSHA256_SIZE];
 233         unsigned char *hashptr = prfhash;
 234
 235         memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
 236         memset(key, 0x0, key_size);
 237
 238         rc = smb3_crypto_shash_allocate(ses->server);
 239         if (rc) {
 240                 cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
 241                 goto smb3signkey_ret;
 242         }
 243
 244         rc = crypto_shash_setkey(ses->server->secmech.hmacsha256,
 245                 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 246         if (rc) {
 247                 cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
 248                 goto smb3signkey_ret;
 249         }
 250
 251         rc = crypto_shash_init(&ses->server->secmech.sdeschmacsha256->shash);
 252         if (rc) {
 253                 cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
 254                 goto smb3signkey_ret;
 255         }
 256
 257         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 258                                 i, 4);
 259         if (rc) {
 260                 cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
 261                 goto smb3signkey_ret;
 262         }
 263
 264         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 265                                 label.iov_base, label.iov_len);
 266         if (rc) {
 267                 cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
 268                 goto smb3signkey_ret;
 269         }
 270
 271         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 272                                 &zero, 1);
 273         if (rc) {
 274                 cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
 275                 goto smb3signkey_ret;
 276         }
 277
 278         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 279                                 context.iov_base, context.iov_len);
 280         if (rc) {
 281                 cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
 282                 goto smb3signkey_ret;
 283         }
 284
 285         rc = crypto_shash_update(&ses->server->secmech.sdeschmacsha256->shash,
 286                                 L, 4);
 287         if (rc) {
 288                 cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
 289                 goto smb3signkey_ret;
 290         }
 291
 292         rc = crypto_shash_final(&ses->server->secmech.sdeschmacsha256->shash,
 293                                 hashptr);
 294         if (rc) {
 295                 cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
 296                 goto smb3signkey_ret;
 297         }
 298
 299         memcpy(key, hashptr, key_size);
 300
 301 smb3signkey_ret:
 302         return rc;
 303 }
 304
 305 struct derivation {
 306         struct kvec label;
 307         struct kvec context;
 308 };
 309
 310 struct derivation_triplet {
 311         struct derivation signing;
 312         struct derivation encryption;
 313         struct derivation decryption;
 314 };
 315
 316 static int
 317 generate_smb3signingkey(struct cifs_ses *ses,
 318                         const struct derivation_triplet *ptriplet)
 319 {
 320         int rc;
 321
 322         rc = generate_key(ses, ptriplet->signing.label,
 323                           ptriplet->signing.context, ses->smb3signingkey,
 324                           SMB3_SIGN_KEY_SIZE);
 325         if (rc)
 326                 return rc;
 327
 328         rc = generate_key(ses, ptriplet->encryption.label,
 329                           ptriplet->encryption.context, ses->smb3encryptionkey,
 330                           SMB3_SIGN_KEY_SIZE);
 331         if (rc)
 332                 return rc;
 333
 334         return generate_key(ses, ptriplet->decryption.label,
 335                             ptriplet->decryption.context,
 336                             ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE);
 337 }
 338
 339 int
 340 generate_smb30signingkey(struct cifs_ses *ses)
 341
 342 {
 343         struct derivation_triplet triplet;
 344         struct derivation *d;
 345
 346         d = &triplet.signing;
 347         d->label.iov_base = "SMB2AESCMAC";
 348         d->label.iov_len = 12;
 349         d->context.iov_base = "SmbSign";
 350         d->context.iov_len = 8;
 351
 352         d = &triplet.encryption;
 353         d->label.iov_base = "SMB2AESCCM";
 354         d->label.iov_len = 11;
 355         d->context.iov_base = "ServerIn ";
 356         d->context.iov_len = 10;
 357
 358         d = &triplet.decryption;
 359         d->label.iov_base = "SMB2AESCCM";
 360         d->label.iov_len = 11;
 361         d->context.iov_base = "ServerOut";
 362         d->context.iov_len = 10;
 363
 364         return generate_smb3signingkey(ses, &triplet);
 365 }
 366
 367 int
 368 generate_smb311signingkey(struct cifs_ses *ses)
 369
 370 {
 371         struct derivation_triplet triplet;
 372         struct derivation *d;
 373
 374         d = &triplet.signing;
 375         d->label.iov_base = "SMB2AESCMAC";
 376         d->label.iov_len = 12;
 377         d->context.iov_base = "SmbSign";
 378         d->context.iov_len = 8;
 379
 380         d = &triplet.encryption;
 381         d->label.iov_base = "SMB2AESCCM";
 382         d->label.iov_len = 11;
 383         d->context.iov_base = "ServerIn ";
 384         d->context.iov_len = 10;
 385
 386         d = &triplet.decryption;
 387         d->label.iov_base = "SMB2AESCCM";
 388         d->label.iov_len = 11;
 389         d->context.iov_base = "ServerOut";
 390         d->context.iov_len = 10;
 391
 392         return generate_smb3signingkey(ses, &triplet);
 393 }
 394
 395 int
 396 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 397 {
 398         int i;
 399         int rc = 0;
 400         unsigned char smb3_signature[SMB2_CMACAES_SIZE];
 401         unsigned char *sigptr = smb3_signature;
 402         struct kvec *iov = rqst->rq_iov;
 403         int n_vec = rqst->rq_nvec;
 404         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
 405         struct cifs_ses *ses;
 406
 407         ses = smb2_find_smb_ses(smb2_pdu, server);
 408         if (!ses) {
 409                 cifs_dbg(VFS, "%s: Could not find session\n", __func__);
 410                 return 0;
 411         }
 412
 413         memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
 414         memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 415
 416         rc = crypto_shash_setkey(server->secmech.cmacaes,
 417                 ses->smb3signingkey, SMB2_CMACAES_SIZE);
 418
 419         if (rc) {
 420                 cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
 421                 return rc;
 422         }
 423
 424         /*
 425          * we already allocate sdesccmacaes when we init smb3 signing key,
 426          * so unlike smb2 case we do not have to check here if secmech are
 427          * initialized
 428          */
 429         rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
 430         if (rc) {
 431                 cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
 432                 return rc;
 433         }
 434
 435         for (i = 0; i < n_vec; i++) {
 436                 if (iov[i].iov_len == 0)
 437                         continue;
 438                 if (iov[i].iov_base == NULL) {
 439                         cifs_dbg(VFS, "null iovec entry");
 440                         return -EIO;
 441                 }
 442                 /*
 443                  * The first entry includes a length field (which does not get
 444                  * signed that occupies the first 4 bytes before the header).
 445                  */
 446                 if (i == 0) {
 447                         if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
 448                                 break; /* nothing to sign or corrupt header */
 449                         rc =
 450                         crypto_shash_update(
 451                                 &server->secmech.sdesccmacaes->shash,
 452                                 iov[i].iov_base + 4, iov[i].iov_len - 4);
 453                 } else {
 454                         rc =
 455                         crypto_shash_update(
 456                                 &server->secmech.sdesccmacaes->shash,
 457                                 iov[i].iov_base, iov[i].iov_len);
 458                 }
 459                 if (rc) {
 460                         cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
 461                                                         __func__);
 462                         return rc;
 463                 }
 464         }
 465
 466         /* now hash over the rq_pages array */
 467         for (i = 0; i < rqst->rq_npages; i++) {
 468                 struct kvec p_iov;
 469
 470                 cifs_rqst_page_to_kvec(rqst, i, &p_iov);
 471                 crypto_shash_update(&server->secmech.sdesccmacaes->shash,
 472                                         p_iov.iov_base, p_iov.iov_len);
 473                 kunmap(rqst->rq_pages[i]);
 474         }
 475
 476         rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
 477                                                 sigptr);
 478         if (rc)
 479                 cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);
 480
 481         memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 482
 483         return rc;
 484 }
 485
 486 /* must be called with server->srv_mutex held */
 487 static int
 488 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 489 {
 490         int rc = 0;
 491         struct smb2_hdr *smb2_pdu = rqst->rq_iov[0].iov_base;
 492
 493         if (!(smb2_pdu->Flags & SMB2_FLAGS_SIGNED) ||
 494             server->tcpStatus == CifsNeedNegotiate)
 495                 return rc;
 496
 497         if (!server->session_estab) {
 498                 strncpy(smb2_pdu->Signature, "BSRSPYL", 8);
 499                 return rc;
 500         }
 501
 502         rc = server->ops->calc_signature(rqst, server);
 503
 504         return rc;
 505 }
 506
 507 int
 508 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 509 {
 510         unsigned int rc;
 511         char server_response_sig[16];
 512         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 513
 514         if ((smb2_pdu->Command == SMB2_NEGOTIATE) ||
 515             (smb2_pdu->Command == SMB2_SESSION_SETUP) ||
 516             (smb2_pdu->Command == SMB2_OPLOCK_BREAK) ||
 517             (!server->session_estab))
 518                 return 0;
 519
 520         /*
 521          * BB what if signatures are supposed to be on for session but
 522          * server does not send one? BB
 523          */
 524
 525         /* Do not need to verify session setups with signature "BSRSPYL " */
 526         if (memcmp(smb2_pdu->Signature, "BSRSPYL ", 8) == 0)
 527                 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 528                          smb2_pdu->Command);
 529
 530         /*
 531          * Save off the origiginal signature so we can modify the smb and check
 532          * our calculated signature against what the server sent.
 533          */
 534         memcpy(server_response_sig, smb2_pdu->Signature, SMB2_SIGNATURE_SIZE);
 535
 536         memset(smb2_pdu->Signature, 0, SMB2_SIGNATURE_SIZE);
 537
 538         mutex_lock(&server->srv_mutex);
 539         rc = server->ops->calc_signature(rqst, server);
 540         mutex_unlock(&server->srv_mutex);
 541
 542         if (rc)
 543                 return rc;
 544
 545         if (memcmp(server_response_sig, smb2_pdu->Signature,
 546                    SMB2_SIGNATURE_SIZE))
 547                 return -EACCES;
 548         else
 549                 return 0;
 550 }
 551
 552 /*
 553  * Set message id for the request. Should be called after wait_for_free_request
 554  * and when srv_mutex is held.
 555  */
 556 static inline void
 557 smb2_seq_num_into_buf(struct TCP_Server_Info *server, struct smb2_hdr *hdr)
 558 {
 559         unsigned int i, num = le16_to_cpu(hdr->CreditCharge);
 560
 561         hdr->MessageId = get_next_mid64(server);
 562         /* skip message numbers according to CreditCharge field */
 563         for (i = 1; i < num; i++)
 564                 get_next_mid(server);
 565 }
 566
 567 static struct mid_q_entry *
 568 smb2_mid_entry_alloc(const struct smb2_hdr *smb_buffer,
 569                      struct TCP_Server_Info *server)
 570 {
 571         struct mid_q_entry *temp;
 572
 573         if (server == NULL) {
 574                 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
 575                 return NULL;
 576         }
 577
 578         temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
 579         if (temp == NULL)
 580                 return temp;
 581         else {
 582                 memset(temp, 0, sizeof(struct mid_q_entry));
 583                 temp->mid = le64_to_cpu(smb_buffer->MessageId);
 584                 temp->pid = current->pid;
 585                 temp->command = smb_buffer->Command;    /* Always LE */
 586                 temp->when_alloc = jiffies;
 587                 temp->server = server;
 588
 589                 /*
 590                  * The default is for the mid to be synchronous, so the
 591                  * default callback just wakes up the current task.
 592                  */
 593                 temp->callback = cifs_wake_up_task;
 594                 temp->callback_data = current;
 595         }
 596
 597         atomic_inc(&midCount);
 598         temp->mid_state = MID_REQUEST_ALLOCATED;
 599         return temp;
 600 }
 601
 602 static int
 603 smb2_get_mid_entry(struct cifs_ses *ses, struct smb2_hdr *buf,
 604                    struct mid_q_entry **mid)
 605 {
 606         if (ses->server->tcpStatus == CifsExiting)
 607                 return -ENOENT;
 608
 609         if (ses->server->tcpStatus == CifsNeedReconnect) {
 610                 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
 611                 return -EAGAIN;
 612         }
 613
 614         if (ses->status == CifsNew) {
 615                 if ((buf->Command != SMB2_SESSION_SETUP) &&
 616                     (buf->Command != SMB2_NEGOTIATE))
 617                         return -EAGAIN;
 618                 /* else ok - we are setting up session */
 619         }
 620
 621         if (ses->status == CifsExiting) {
 622                 if (buf->Command != SMB2_LOGOFF)
 623                         return -EAGAIN;
 624                 /* else ok - we are shutting down the session */
 625         }
 626
 627         *mid = smb2_mid_entry_alloc(buf, ses->server);
 628         if (*mid == NULL)
 629                 return -ENOMEM;
 630         spin_lock(&GlobalMid_Lock);
 631         list_add_tail(&(*mid)->qhead, &ses->server->pending_mid_q);
 632         spin_unlock(&GlobalMid_Lock);
 633         return 0;
 634 }
 635
 636 int
 637 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 638                    bool log_error)
 639 {
 640         unsigned int len = get_rfc1002_length(mid->resp_buf);
 641         struct kvec iov;
 642         struct smb_rqst rqst = { .rq_iov = &iov,
 643                                  .rq_nvec = 1 };
 644
 645         iov.iov_base = (char *)mid->resp_buf;
 646         iov.iov_len = get_rfc1002_length(mid->resp_buf) + 4;
 647
 648         dump_smb(mid->resp_buf, min_t(u32, 80, len));
 649         /* convert the length into a more usable form */
 650         if (len > 24 && server->sign) {
 651                 int rc;
 652
 653                 rc = smb2_verify_signature(&rqst, server);
 654                 if (rc)
 655                         cifs_dbg(VFS, "SMB signature verification returned error = %d\n",
 656                                  rc);
 657         }
 658
 659         return map_smb2_to_linux_error(mid->resp_buf, log_error);
 660 }
 661
 662 struct mid_q_entry *
 663 smb2_setup_request(struct cifs_ses *ses, struct smb_rqst *rqst)
 664 {
 665         int rc;
 666         struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 667         struct mid_q_entry *mid;
 668
 669         smb2_seq_num_into_buf(ses->server, hdr);
 670
 671         rc = smb2_get_mid_entry(ses, hdr, &mid);
 672         if (rc)
 673                 return ERR_PTR(rc);
 674         rc = smb2_sign_rqst(rqst, ses->server);
 675         if (rc) {
 676                 cifs_delete_mid(mid);
 677                 return ERR_PTR(rc);
 678         }
 679         return mid;
 680 }
 681
 682 struct mid_q_entry *
 683 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 684 {
 685         int rc;
 686         struct smb2_hdr *hdr = (struct smb2_hdr *)rqst->rq_iov[0].iov_base;
 687         struct mid_q_entry *mid;
 688
 689         smb2_seq_num_into_buf(server, hdr);
 690
 691         mid = smb2_mid_entry_alloc(hdr, server);
 692         if (mid == NULL)
 693                 return ERR_PTR(-ENOMEM);
 694
 695         rc = smb2_sign_rqst(rqst, server);
 696         if (rc) {
 697                 DeleteMidQEntry(mid);
 698                 return ERR_PTR(rc);
 699         }
 700
 701         return mid;
 702 }