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
 102 static
 103 int smb2_get_sign_key(__u64 ses_id, struct TCP_Server_Info *server, u8 *key)
 104 {
 105         struct cifs_chan *chan;
 106         struct cifs_ses *ses = NULL;
 107         struct TCP_Server_Info *it = NULL;
 108         int i;
 109         int rc = 0;
 110
 111         spin_lock(&cifs_tcp_ses_lock);
 112
 113         list_for_each_entry(it, &cifs_tcp_ses_list, tcp_ses_list) {
 114                 list_for_each_entry(ses, &it->smb_ses_list, smb_ses_list) {
 115                         if (ses->Suid == ses_id)
 116                                 goto found;
 117                 }
 118         }
 119         cifs_server_dbg(VFS, "%s: Could not find session 0x%llx\n",
 120                         __func__, ses_id);
 121         rc = -ENOENT;
 122         goto out;
 123
 124 found:
 125         if (ses->binding) {
 126                 /*
 127                  * If we are in the process of binding a new channel
 128                  * to an existing session, use the master connection
 129                  * session key
 130                  */
 131                 memcpy(key, ses->smb3signingkey, SMB3_SIGN_KEY_SIZE);
 132                 goto out;
 133         }
 134
 135         /*
 136          * Otherwise, use the channel key.
 137          */
 138
 139         for (i = 0; i < ses->chan_count; i++) {
 140                 chan = ses->chans + i;
 141                 if (chan->server == server) {
 142                         memcpy(key, chan->signkey, SMB3_SIGN_KEY_SIZE);
 143                         goto out;
 144                 }
 145         }
 146
 147         cifs_dbg(VFS,
 148                  "%s: Could not find channel signing key for session 0x%llx\n",
 149                  __func__, ses_id);
 150         rc = -ENOENT;
 151
 152 out:
 153         spin_unlock(&cifs_tcp_ses_lock);
 154         return rc;
 155 }
 156
 157 static struct cifs_ses *
 158 smb2_find_smb_ses_unlocked(struct TCP_Server_Info *server, __u64 ses_id)
 159 {
 160         struct cifs_ses *ses;
 161
 162         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 163                 if (ses->Suid != ses_id)
 164                         continue;
 165                 return ses;
 166         }
 167
 168         return NULL;
 169 }
 170
 171 struct cifs_ses *
 172 smb2_find_smb_ses(struct TCP_Server_Info *server, __u64 ses_id)
 173 {
 174         struct cifs_ses *ses;
 175
 176         spin_lock(&cifs_tcp_ses_lock);
 177         ses = smb2_find_smb_ses_unlocked(server, ses_id);
 178         spin_unlock(&cifs_tcp_ses_lock);
 179
 180         return ses;
 181 }
 182
 183 static struct cifs_tcon *
 184 smb2_find_smb_sess_tcon_unlocked(struct cifs_ses *ses, __u32  tid)
 185 {
 186         struct cifs_tcon *tcon;
 187
 188         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 189                 if (tcon->tid != tid)
 190                         continue;
 191                 ++tcon->tc_count;
 192                 return tcon;
 193         }
 194
 195         return NULL;
 196 }
 197
 198 /*
 199  * Obtain tcon corresponding to the tid in the given
 200  * cifs_ses
 201  */
 202
 203 struct cifs_tcon *
 204 smb2_find_smb_tcon(struct TCP_Server_Info *server, __u64 ses_id, __u32  tid)
 205 {
 206         struct cifs_ses *ses;
 207         struct cifs_tcon *tcon;
 208
 209         spin_lock(&cifs_tcp_ses_lock);
 210         ses = smb2_find_smb_ses_unlocked(server, ses_id);
 211         if (!ses) {
 212                 spin_unlock(&cifs_tcp_ses_lock);
 213                 return NULL;
 214         }
 215         tcon = smb2_find_smb_sess_tcon_unlocked(ses, tid);
 216         spin_unlock(&cifs_tcp_ses_lock);
 217
 218         return tcon;
 219 }
 220
 221 int
 222 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 223 {
 224         int rc;
 225         unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
 226         unsigned char *sigptr = smb2_signature;
 227         struct kvec *iov = rqst->rq_iov;
 228         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
 229         struct cifs_ses *ses;
 230         struct shash_desc *shash;
 231         struct smb_rqst drqst;
 232
 233         ses = smb2_find_smb_ses(server, shdr->SessionId);
 234         if (!ses) {
 235                 cifs_server_dbg(VFS, "%s: Could not find session\n", __func__);
 236                 return 0;
 237         }
 238
 239         memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
 240         memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 241
 242         rc = smb2_crypto_shash_allocate(server);
 243         if (rc) {
 244                 cifs_server_dbg(VFS, "%s: sha256 alloc failed\n", __func__);
 245                 return rc;
 246         }
 247
 248         rc = crypto_shash_setkey(server->secmech.hmacsha256,
 249                                  ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 250         if (rc) {
 251                 cifs_server_dbg(VFS, "%s: Could not update with response\n", __func__);
 252                 return rc;
 253         }
 254
 255         shash = &server->secmech.sdeschmacsha256->shash;
 256         rc = crypto_shash_init(shash);
 257         if (rc) {
 258                 cifs_server_dbg(VFS, "%s: Could not init sha256", __func__);
 259                 return rc;
 260         }
 261
 262         /*
 263          * For SMB2+, __cifs_calc_signature() expects to sign only the actual
 264          * data, that is, iov[0] should not contain a rfc1002 length.
 265          *
 266          * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
 267          * __cifs_calc_signature().
 268          */
 269         drqst = *rqst;
 270         if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
 271                 rc = crypto_shash_update(shash, iov[0].iov_base,
 272                                          iov[0].iov_len);
 273                 if (rc) {
 274                         cifs_server_dbg(VFS, "%s: Could not update with payload\n",
 275                                  __func__);
 276                         return rc;
 277                 }
 278                 drqst.rq_iov++;
 279                 drqst.rq_nvec--;
 280         }
 281
 282         rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
 283         if (!rc)
 284                 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 285
 286         return rc;
 287 }
 288
 289 static int generate_key(struct cifs_ses *ses, struct kvec label,
 290                         struct kvec context, __u8 *key, unsigned int key_size)
 291 {
 292         unsigned char zero = 0x0;
 293         __u8 i[4] = {0, 0, 0, 1};
 294         __u8 L[4] = {0, 0, 0, 128};
 295         int rc = 0;
 296         unsigned char prfhash[SMB2_HMACSHA256_SIZE];
 297         unsigned char *hashptr = prfhash;
 298         struct TCP_Server_Info *server = ses->server;
 299
 300         memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
 301         memset(key, 0x0, key_size);
 302
 303         rc = smb3_crypto_shash_allocate(server);
 304         if (rc) {
 305                 cifs_server_dbg(VFS, "%s: crypto alloc failed\n", __func__);
 306                 goto smb3signkey_ret;
 307         }
 308
 309         rc = crypto_shash_setkey(server->secmech.hmacsha256,
 310                 ses->auth_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
 311         if (rc) {
 312                 cifs_server_dbg(VFS, "%s: Could not set with session key\n", __func__);
 313                 goto smb3signkey_ret;
 314         }
 315
 316         rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
 317         if (rc) {
 318                 cifs_server_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
 319                 goto smb3signkey_ret;
 320         }
 321
 322         rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 323                                 i, 4);
 324         if (rc) {
 325                 cifs_server_dbg(VFS, "%s: Could not update with n\n", __func__);
 326                 goto smb3signkey_ret;
 327         }
 328
 329         rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 330                                 label.iov_base, label.iov_len);
 331         if (rc) {
 332                 cifs_server_dbg(VFS, "%s: Could not update with label\n", __func__);
 333                 goto smb3signkey_ret;
 334         }
 335
 336         rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 337                                 &zero, 1);
 338         if (rc) {
 339                 cifs_server_dbg(VFS, "%s: Could not update with zero\n", __func__);
 340                 goto smb3signkey_ret;
 341         }
 342
 343         rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 344                                 context.iov_base, context.iov_len);
 345         if (rc) {
 346                 cifs_server_dbg(VFS, "%s: Could not update with context\n", __func__);
 347                 goto smb3signkey_ret;
 348         }
 349
 350         rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
 351                                 L, 4);
 352         if (rc) {
 353                 cifs_server_dbg(VFS, "%s: Could not update with L\n", __func__);
 354                 goto smb3signkey_ret;
 355         }
 356
 357         rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
 358                                 hashptr);
 359         if (rc) {
 360                 cifs_server_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
 361                 goto smb3signkey_ret;
 362         }
 363
 364         memcpy(key, hashptr, key_size);
 365
 366 smb3signkey_ret:
 367         return rc;
 368 }
 369
 370 struct derivation {
 371         struct kvec label;
 372         struct kvec context;
 373 };
 374
 375 struct derivation_triplet {
 376         struct derivation signing;
 377         struct derivation encryption;
 378         struct derivation decryption;
 379 };
 380
 381 static int
 382 generate_smb3signingkey(struct cifs_ses *ses,
 383                         const struct derivation_triplet *ptriplet)
 384 {
 385         int rc;
 386
 387         /*
 388          * All channels use the same encryption/decryption keys but
 389          * they have their own signing key.
 390          *
 391          * When we generate the keys, check if it is for a new channel
 392          * (binding) in which case we only need to generate a signing
 393          * key and store it in the channel as to not overwrite the
 394          * master connection signing key stored in the session
 395          */
 396
 397         if (ses->binding) {
 398                 rc = generate_key(ses, ptriplet->signing.label,
 399                                   ptriplet->signing.context,
 400                                   cifs_ses_binding_channel(ses)->signkey,
 401                                   SMB3_SIGN_KEY_SIZE);
 402                 if (rc)
 403                         return rc;
 404         } else {
 405                 rc = generate_key(ses, ptriplet->signing.label,
 406                                   ptriplet->signing.context,
 407                                   ses->smb3signingkey,
 408                                   SMB3_SIGN_KEY_SIZE);
 409                 if (rc)
 410                         return rc;
 411
 412                 memcpy(ses->chans[0].signkey, ses->smb3signingkey,
 413                        SMB3_SIGN_KEY_SIZE);
 414
 415                 rc = generate_key(ses, ptriplet->encryption.label,
 416                                   ptriplet->encryption.context,
 417                                   ses->smb3encryptionkey,
 418                                   SMB3_SIGN_KEY_SIZE);
 419                 rc = generate_key(ses, ptriplet->decryption.label,
 420                                   ptriplet->decryption.context,
 421                                   ses->smb3decryptionkey,
 422                                   SMB3_SIGN_KEY_SIZE);
 423                 if (rc)
 424                         return rc;
 425         }
 426
 427         if (rc)
 428                 return rc;
 429
 430 #ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS
 431         cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__);
 432         /*
 433          * The session id is opaque in terms of endianness, so we can't
 434          * print it as a long long. we dump it as we got it on the wire
 435          */
 436         cifs_dbg(VFS, "Session Id    %*ph\n", (int)sizeof(ses->Suid),
 437                         &ses->Suid);
 438         cifs_dbg(VFS, "Session Key   %*ph\n",
 439                  SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response);
 440         cifs_dbg(VFS, "Signing Key   %*ph\n",
 441                  SMB3_SIGN_KEY_SIZE, ses->smb3signingkey);
 442         cifs_dbg(VFS, "ServerIn Key  %*ph\n",
 443                  SMB3_SIGN_KEY_SIZE, ses->smb3encryptionkey);
 444         cifs_dbg(VFS, "ServerOut Key %*ph\n",
 445                  SMB3_SIGN_KEY_SIZE, ses->smb3decryptionkey);
 446 #endif
 447         return rc;
 448 }
 449
 450 int
 451 generate_smb30signingkey(struct cifs_ses *ses)
 452
 453 {
 454         struct derivation_triplet triplet;
 455         struct derivation *d;
 456
 457         d = &triplet.signing;
 458         d->label.iov_base = "SMB2AESCMAC";
 459         d->label.iov_len = 12;
 460         d->context.iov_base = "SmbSign";
 461         d->context.iov_len = 8;
 462
 463         d = &triplet.encryption;
 464         d->label.iov_base = "SMB2AESCCM";
 465         d->label.iov_len = 11;
 466         d->context.iov_base = "ServerIn ";
 467         d->context.iov_len = 10;
 468
 469         d = &triplet.decryption;
 470         d->label.iov_base = "SMB2AESCCM";
 471         d->label.iov_len = 11;
 472         d->context.iov_base = "ServerOut";
 473         d->context.iov_len = 10;
 474
 475         return generate_smb3signingkey(ses, &triplet);
 476 }
 477
 478 int
 479 generate_smb311signingkey(struct cifs_ses *ses)
 480
 481 {
 482         struct derivation_triplet triplet;
 483         struct derivation *d;
 484
 485         d = &triplet.signing;
 486         d->label.iov_base = "SMBSigningKey";
 487         d->label.iov_len = 14;
 488         d->context.iov_base = ses->preauth_sha_hash;
 489         d->context.iov_len = 64;
 490
 491         d = &triplet.encryption;
 492         d->label.iov_base = "SMBC2SCipherKey";
 493         d->label.iov_len = 16;
 494         d->context.iov_base = ses->preauth_sha_hash;
 495         d->context.iov_len = 64;
 496
 497         d = &triplet.decryption;
 498         d->label.iov_base = "SMBS2CCipherKey";
 499         d->label.iov_len = 16;
 500         d->context.iov_base = ses->preauth_sha_hash;
 501         d->context.iov_len = 64;
 502
 503         return generate_smb3signingkey(ses, &triplet);
 504 }
 505
 506 int
 507 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 508 {
 509         int rc;
 510         unsigned char smb3_signature[SMB2_CMACAES_SIZE];
 511         unsigned char *sigptr = smb3_signature;
 512         struct kvec *iov = rqst->rq_iov;
 513         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)iov[0].iov_base;
 514         struct shash_desc *shash = &server->secmech.sdesccmacaes->shash;
 515         struct smb_rqst drqst;
 516         u8 key[SMB3_SIGN_KEY_SIZE];
 517
 518         rc = smb2_get_sign_key(shdr->SessionId, server, key);
 519         if (rc)
 520                 return 0;
 521
 522         memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
 523         memset(shdr->Signature, 0x0, SMB2_SIGNATURE_SIZE);
 524
 525         rc = crypto_shash_setkey(server->secmech.cmacaes,
 526                                  key, SMB2_CMACAES_SIZE);
 527         if (rc) {
 528                 cifs_server_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
 529                 return rc;
 530         }
 531
 532         /*
 533          * we already allocate sdesccmacaes when we init smb3 signing key,
 534          * so unlike smb2 case we do not have to check here if secmech are
 535          * initialized
 536          */
 537         rc = crypto_shash_init(shash);
 538         if (rc) {
 539                 cifs_server_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
 540                 return rc;
 541         }
 542
 543         /*
 544          * For SMB2+, __cifs_calc_signature() expects to sign only the actual
 545          * data, that is, iov[0] should not contain a rfc1002 length.
 546          *
 547          * Sign the rfc1002 length prior to passing the data (iov[1-N]) down to
 548          * __cifs_calc_signature().
 549          */
 550         drqst = *rqst;
 551         if (drqst.rq_nvec >= 2 && iov[0].iov_len == 4) {
 552                 rc = crypto_shash_update(shash, iov[0].iov_base,
 553                                          iov[0].iov_len);
 554                 if (rc) {
 555                         cifs_server_dbg(VFS, "%s: Could not update with payload\n",
 556                                  __func__);
 557                         return rc;
 558                 }
 559                 drqst.rq_iov++;
 560                 drqst.rq_nvec--;
 561         }
 562
 563         rc = __cifs_calc_signature(&drqst, server, sigptr, shash);
 564         if (!rc)
 565                 memcpy(shdr->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 566
 567         return rc;
 568 }
 569
 570 /* must be called with server->srv_mutex held */
 571 static int
 572 smb2_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 573 {
 574         int rc = 0;
 575         struct smb2_sync_hdr *shdr;
 576         struct smb2_sess_setup_req *ssr;
 577         bool is_binding;
 578         bool is_signed;
 579
 580         shdr = (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 581         ssr = (struct smb2_sess_setup_req *)shdr;
 582
 583         is_binding = shdr->Command == SMB2_SESSION_SETUP &&
 584                 (ssr->Flags & SMB2_SESSION_REQ_FLAG_BINDING);
 585         is_signed = shdr->Flags & SMB2_FLAGS_SIGNED;
 586
 587         if (!is_signed)
 588                 return 0;
 589         if (server->tcpStatus == CifsNeedNegotiate)
 590                 return 0;
 591         if (!is_binding && !server->session_estab) {
 592                 strncpy(shdr->Signature, "BSRSPYL", 8);
 593                 return 0;
 594         }
 595
 596         rc = server->ops->calc_signature(rqst, server);
 597
 598         return rc;
 599 }
 600
 601 int
 602 smb2_verify_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 603 {
 604         unsigned int rc;
 605         char server_response_sig[16];
 606         struct smb2_sync_hdr *shdr =
 607                         (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 608
 609         if ((shdr->Command == SMB2_NEGOTIATE) ||
 610             (shdr->Command == SMB2_SESSION_SETUP) ||
 611             (shdr->Command == SMB2_OPLOCK_BREAK) ||
 612             server->ignore_signature ||
 613             (!server->session_estab))
 614                 return 0;
 615
 616         /*
 617          * BB what if signatures are supposed to be on for session but
 618          * server does not send one? BB
 619          */
 620
 621         /* Do not need to verify session setups with signature "BSRSPYL " */
 622         if (memcmp(shdr->Signature, "BSRSPYL ", 8) == 0)
 623                 cifs_dbg(FYI, "dummy signature received for smb command 0x%x\n",
 624                          shdr->Command);
 625
 626         /*
 627          * Save off the origiginal signature so we can modify the smb and check
 628          * our calculated signature against what the server sent.
 629          */
 630         memcpy(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE);
 631
 632         memset(shdr->Signature, 0, SMB2_SIGNATURE_SIZE);
 633
 634         mutex_lock(&server->srv_mutex);
 635         rc = server->ops->calc_signature(rqst, server);
 636         mutex_unlock(&server->srv_mutex);
 637
 638         if (rc)
 639                 return rc;
 640
 641         if (memcmp(server_response_sig, shdr->Signature, SMB2_SIGNATURE_SIZE))
 642                 return -EACCES;
 643         else
 644                 return 0;
 645 }
 646
 647 /*
 648  * Set message id for the request. Should be called after wait_for_free_request
 649  * and when srv_mutex is held.
 650  */
 651 static inline void
 652 smb2_seq_num_into_buf(struct TCP_Server_Info *server,
 653                       struct smb2_sync_hdr *shdr)
 654 {
 655         unsigned int i, num = le16_to_cpu(shdr->CreditCharge);
 656
 657         shdr->MessageId = get_next_mid64(server);
 658         /* skip message numbers according to CreditCharge field */
 659         for (i = 1; i < num; i++)
 660                 get_next_mid(server);
 661 }
 662
 663 static struct mid_q_entry *
 664 smb2_mid_entry_alloc(const struct smb2_sync_hdr *shdr,
 665                      struct TCP_Server_Info *server)
 666 {
 667         struct mid_q_entry *temp;
 668         unsigned int credits = le16_to_cpu(shdr->CreditCharge);
 669
 670         if (server == NULL) {
 671                 cifs_dbg(VFS, "Null TCP session in smb2_mid_entry_alloc\n");
 672                 return NULL;
 673         }
 674
 675         temp = mempool_alloc(cifs_mid_poolp, GFP_NOFS);
 676         memset(temp, 0, sizeof(struct mid_q_entry));
 677         kref_init(&temp->refcount);
 678         temp->mid = le64_to_cpu(shdr->MessageId);
 679         temp->credits = credits > 0 ? credits : 1;
 680         temp->pid = current->pid;
 681         temp->command = shdr->Command; /* Always LE */
 682         temp->when_alloc = jiffies;
 683         temp->server = server;
 684
 685         /*
 686          * The default is for the mid to be synchronous, so the
 687          * default callback just wakes up the current task.
 688          */
 689         get_task_struct(current);
 690         temp->creator = current;
 691         temp->callback = cifs_wake_up_task;
 692         temp->callback_data = current;
 693
 694         atomic_inc(&midCount);
 695         temp->mid_state = MID_REQUEST_ALLOCATED;
 696         trace_smb3_cmd_enter(shdr->TreeId, shdr->SessionId,
 697                 le16_to_cpu(shdr->Command), temp->mid);
 698         return temp;
 699 }
 700
 701 static int
 702 smb2_get_mid_entry(struct cifs_ses *ses, struct TCP_Server_Info *server,
 703                    struct smb2_sync_hdr *shdr, struct mid_q_entry **mid)
 704 {
 705         if (server->tcpStatus == CifsExiting)
 706                 return -ENOENT;
 707
 708         if (server->tcpStatus == CifsNeedReconnect) {
 709                 cifs_dbg(FYI, "tcp session dead - return to caller to retry\n");
 710                 return -EAGAIN;
 711         }
 712
 713         if (server->tcpStatus == CifsNeedNegotiate &&
 714            shdr->Command != SMB2_NEGOTIATE)
 715                 return -EAGAIN;
 716
 717         if (ses->status == CifsNew) {
 718                 if ((shdr->Command != SMB2_SESSION_SETUP) &&
 719                     (shdr->Command != SMB2_NEGOTIATE))
 720                         return -EAGAIN;
 721                 /* else ok - we are setting up session */
 722         }
 723
 724         if (ses->status == CifsExiting) {
 725                 if (shdr->Command != SMB2_LOGOFF)
 726                         return -EAGAIN;
 727                 /* else ok - we are shutting down the session */
 728         }
 729
 730         *mid = smb2_mid_entry_alloc(shdr, server);
 731         if (*mid == NULL)
 732                 return -ENOMEM;
 733         spin_lock(&GlobalMid_Lock);
 734         list_add_tail(&(*mid)->qhead, &server->pending_mid_q);
 735         spin_unlock(&GlobalMid_Lock);
 736
 737         return 0;
 738 }
 739
 740 int
 741 smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 742                    bool log_error)
 743 {
 744         unsigned int len = mid->resp_buf_size;
 745         struct kvec iov[1];
 746         struct smb_rqst rqst = { .rq_iov = iov,
 747                                  .rq_nvec = 1 };
 748
 749         iov[0].iov_base = (char *)mid->resp_buf;
 750         iov[0].iov_len = len;
 751
 752         dump_smb(mid->resp_buf, min_t(u32, 80, len));
 753         /* convert the length into a more usable form */
 754         if (len > 24 && server->sign && !mid->decrypted) {
 755                 int rc;
 756
 757                 rc = smb2_verify_signature(&rqst, server);
 758                 if (rc)
 759                         cifs_server_dbg(VFS, "SMB signature verification returned error = %d\n",
 760                                  rc);
 761         }
 762
 763         return map_smb2_to_linux_error(mid->resp_buf, log_error);
 764 }
 765
 766 struct mid_q_entry *
 767 smb2_setup_request(struct cifs_ses *ses, struct TCP_Server_Info *server,
 768                    struct smb_rqst *rqst)
 769 {
 770         int rc;
 771         struct smb2_sync_hdr *shdr =
 772                         (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 773         struct mid_q_entry *mid;
 774
 775         smb2_seq_num_into_buf(server, shdr);
 776
 777         rc = smb2_get_mid_entry(ses, server, shdr, &mid);
 778         if (rc) {
 779                 revert_current_mid_from_hdr(server, shdr);
 780                 return ERR_PTR(rc);
 781         }
 782
 783         rc = smb2_sign_rqst(rqst, server);
 784         if (rc) {
 785                 revert_current_mid_from_hdr(server, shdr);
 786                 cifs_delete_mid(mid);
 787                 return ERR_PTR(rc);
 788         }
 789
 790         return mid;
 791 }
 792
 793 struct mid_q_entry *
 794 smb2_setup_async_request(struct TCP_Server_Info *server, struct smb_rqst *rqst)
 795 {
 796         int rc;
 797         struct smb2_sync_hdr *shdr =
 798                         (struct smb2_sync_hdr *)rqst->rq_iov[0].iov_base;
 799         struct mid_q_entry *mid;
 800
 801         if (server->tcpStatus == CifsNeedNegotiate &&
 802            shdr->Command != SMB2_NEGOTIATE)
 803                 return ERR_PTR(-EAGAIN);
 804
 805         smb2_seq_num_into_buf(server, shdr);
 806
 807         mid = smb2_mid_entry_alloc(shdr, server);
 808         if (mid == NULL) {
 809                 revert_current_mid_from_hdr(server, shdr);
 810                 return ERR_PTR(-ENOMEM);
 811         }
 812
 813         rc = smb2_sign_rqst(rqst, server);
 814         if (rc) {
 815                 revert_current_mid_from_hdr(server, shdr);
 816                 DeleteMidQEntry(mid);
 817                 return ERR_PTR(rc);
 818         }
 819
 820         return mid;
 821 }
 822
 823 int
 824 smb3_crypto_aead_allocate(struct TCP_Server_Info *server)
 825 {
 826         struct crypto_aead *tfm;
 827
 828         if (!server->secmech.ccmaesencrypt) {
 829                 if (server->cipher_type == SMB2_ENCRYPTION_AES128_GCM)
 830                         tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
 831                 else
 832                         tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
 833                 if (IS_ERR(tfm)) {
 834                         cifs_server_dbg(VFS, "%s: Failed to alloc encrypt aead\n",
 835                                  __func__);
 836                         return PTR_ERR(tfm);
 837                 }
 838                 server->secmech.ccmaesencrypt = tfm;
 839         }
 840
 841         if (!server->secmech.ccmaesdecrypt) {
 842                 if (server->cipher_type == SMB2_ENCRYPTION_AES128_GCM)
 843                         tfm = crypto_alloc_aead("gcm(aes)", 0, 0);
 844                 else
 845                         tfm = crypto_alloc_aead("ccm(aes)", 0, 0);
 846                 if (IS_ERR(tfm)) {
 847                         crypto_free_aead(server->secmech.ccmaesencrypt);
 848                         server->secmech.ccmaesencrypt = NULL;
 849                         cifs_server_dbg(VFS, "%s: Failed to alloc decrypt aead\n",
 850                                  __func__);
 851                         return PTR_ERR(tfm);
 852                 }
 853                 server->secmech.ccmaesdecrypt = tfm;
 854         }
 855
 856         return 0;
 857 }