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