fs/cifs/sess.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   SMB/CIFS session setup handling routines
   5  *
   6  *   Copyright (c) International Business Machines  Corp., 2006, 2009
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *
   9  */
  10
  11 #include "cifspdu.h"
  12 #include "cifsglob.h"
  13 #include "cifsproto.h"
  14 #include "cifs_unicode.h"
  15 #include "cifs_debug.h"
  16 #include "ntlmssp.h"
  17 #include "nterr.h"
  18 #include <linux/utsname.h>
  19 #include <linux/slab.h>
  20 #include <linux/version.h>
  21 #include "cifsfs.h"
  22 #include "cifs_spnego.h"
  23 #include "smb2proto.h"
  24 #include "fs_context.h"
  25
  26 static int
  27 cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
  28                      struct cifs_server_iface *iface);
  29
  30 bool
  31 is_server_using_iface(struct TCP_Server_Info *server,
  32                       struct cifs_server_iface *iface)
  33 {
  34         struct sockaddr_in *i4 = (struct sockaddr_in *)&iface->sockaddr;
  35         struct sockaddr_in6 *i6 = (struct sockaddr_in6 *)&iface->sockaddr;
  36         struct sockaddr_in *s4 = (struct sockaddr_in *)&server->dstaddr;
  37         struct sockaddr_in6 *s6 = (struct sockaddr_in6 *)&server->dstaddr;
  38
  39         if (server->dstaddr.ss_family != iface->sockaddr.ss_family)
  40                 return false;
  41         if (server->dstaddr.ss_family == AF_INET) {
  42                 if (s4->sin_addr.s_addr != i4->sin_addr.s_addr)
  43                         return false;
  44         } else if (server->dstaddr.ss_family == AF_INET6) {
  45                 if (memcmp(&s6->sin6_addr, &i6->sin6_addr,
  46                            sizeof(i6->sin6_addr)) != 0)
  47                         return false;
  48         } else {
  49                 /* unknown family.. */
  50                 return false;
  51         }
  52         return true;
  53 }
  54
  55 bool is_ses_using_iface(struct cifs_ses *ses, struct cifs_server_iface *iface)
  56 {
  57         int i;
  58
  59         spin_lock(&ses->chan_lock);
  60         for (i = 0; i < ses->chan_count; i++) {
  61                 if (ses->chans[i].iface == iface) {
  62                         spin_unlock(&ses->chan_lock);
  63                         return true;
  64                 }
  65         }
  66         spin_unlock(&ses->chan_lock);
  67         return false;
  68 }
  69
  70 /* channel helper functions. assumed that chan_lock is held by caller. */
  71
  72 unsigned int
  73 cifs_ses_get_chan_index(struct cifs_ses *ses,
  74                         struct TCP_Server_Info *server)
  75 {
  76         unsigned int i;
  77
  78         for (i = 0; i < ses->chan_count; i++) {
  79                 if (ses->chans[i].server == server)
  80                         return i;
  81         }
  82
  83         /* If we didn't find the channel, it is likely a bug */
  84         if (server)
  85                 cifs_dbg(VFS, "unable to get chan index for server: 0x%llx",
  86                          server->conn_id);
  87         WARN_ON(1);
  88         return 0;
  89 }
  90
  91 void
  92 cifs_chan_set_in_reconnect(struct cifs_ses *ses,
  93                              struct TCP_Server_Info *server)
  94 {
  95         unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
  96
  97         ses->chans[chan_index].in_reconnect = true;
  98 }
  99
 100 void
 101 cifs_chan_clear_in_reconnect(struct cifs_ses *ses,
 102                              struct TCP_Server_Info *server)
 103 {
 104         unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
 105
 106         ses->chans[chan_index].in_reconnect = false;
 107 }
 108
 109 bool
 110 cifs_chan_in_reconnect(struct cifs_ses *ses,
 111                           struct TCP_Server_Info *server)
 112 {
 113         unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
 114
 115         return CIFS_CHAN_IN_RECONNECT(ses, chan_index);
 116 }
 117
 118 void
 119 cifs_chan_set_need_reconnect(struct cifs_ses *ses,
 120                              struct TCP_Server_Info *server)
 121 {
 122         unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
 123
 124         set_bit(chan_index, &ses->chans_need_reconnect);
 125         cifs_dbg(FYI, "Set reconnect bitmask for chan %u; now 0x%lx\n",
 126                  chan_index, ses->chans_need_reconnect);
 127 }
 128
 129 void
 130 cifs_chan_clear_need_reconnect(struct cifs_ses *ses,
 131                                struct TCP_Server_Info *server)
 132 {
 133         unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
 134
 135         clear_bit(chan_index, &ses->chans_need_reconnect);
 136         cifs_dbg(FYI, "Cleared reconnect bitmask for chan %u; now 0x%lx\n",
 137                  chan_index, ses->chans_need_reconnect);
 138 }
 139
 140 bool
 141 cifs_chan_needs_reconnect(struct cifs_ses *ses,
 142                           struct TCP_Server_Info *server)
 143 {
 144         unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
 145
 146         return CIFS_CHAN_NEEDS_RECONNECT(ses, chan_index);
 147 }
 148
 149 bool
 150 cifs_chan_is_iface_active(struct cifs_ses *ses,
 151                           struct TCP_Server_Info *server)
 152 {
 153         unsigned int chan_index = cifs_ses_get_chan_index(ses, server);
 154
 155         return ses->chans[chan_index].iface &&
 156                 ses->chans[chan_index].iface->is_active;
 157 }
 158
 159 /* returns number of channels added */
 160 int cifs_try_adding_channels(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses)
 161 {
 162         int old_chan_count, new_chan_count;
 163         int left;
 164         int rc = 0;
 165         int tries = 0;
 166         struct cifs_server_iface *iface = NULL, *niface = NULL;
 167
 168         spin_lock(&ses->chan_lock);
 169
 170         new_chan_count = old_chan_count = ses->chan_count;
 171         left = ses->chan_max - ses->chan_count;
 172
 173         if (left <= 0) {
 174                 spin_unlock(&ses->chan_lock);
 175                 cifs_dbg(FYI,
 176                          "ses already at max_channels (%zu), nothing to open\n",
 177                          ses->chan_max);
 178                 return 0;
 179         }
 180
 181         if (ses->server->dialect < SMB30_PROT_ID) {
 182                 spin_unlock(&ses->chan_lock);
 183                 cifs_dbg(VFS, "multichannel is not supported on this protocol version, use 3.0 or above\n");
 184                 return 0;
 185         }
 186
 187         if (!(ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
 188                 ses->chan_max = 1;
 189                 spin_unlock(&ses->chan_lock);
 190                 cifs_dbg(VFS, "server %s does not support multichannel\n", ses->server->hostname);
 191                 return 0;
 192         }
 193         spin_unlock(&ses->chan_lock);
 194
 195         /*
 196          * Keep connecting to same, fastest, iface for all channels as
 197          * long as its RSS. Try next fastest one if not RSS or channel
 198          * creation fails.
 199          */
 200         spin_lock(&ses->iface_lock);
 201         iface = list_first_entry(&ses->iface_list, struct cifs_server_iface,
 202                                  iface_head);
 203         spin_unlock(&ses->iface_lock);
 204
 205         while (left > 0) {
 206
 207                 tries++;
 208                 if (tries > 3*ses->chan_max) {
 209                         cifs_dbg(FYI, "too many channel open attempts (%d channels left to open)\n",
 210                                  left);
 211                         break;
 212                 }
 213
 214                 spin_lock(&ses->iface_lock);
 215                 if (!ses->iface_count) {
 216                         spin_unlock(&ses->iface_lock);
 217                         break;
 218                 }
 219
 220                 list_for_each_entry_safe_from(iface, niface, &ses->iface_list,
 221                                     iface_head) {
 222                         /* skip ifaces that are unusable */
 223                         if (!iface->is_active ||
 224                             (is_ses_using_iface(ses, iface) &&
 225                              !iface->rss_capable)) {
 226                                 continue;
 227                         }
 228
 229                         /* take ref before unlock */
 230                         kref_get(&iface->refcount);
 231
 232                         spin_unlock(&ses->iface_lock);
 233                         rc = cifs_ses_add_channel(cifs_sb, ses, iface);
 234                         spin_lock(&ses->iface_lock);
 235
 236                         if (rc) {
 237                                 cifs_dbg(VFS, "failed to open extra channel on iface:%pIS rc=%d\n",
 238                                          &iface->sockaddr,
 239                                          rc);
 240                                 kref_put(&iface->refcount, release_iface);
 241                                 continue;
 242                         }
 243
 244                         cifs_dbg(FYI, "successfully opened new channel on iface:%pIS\n",
 245                                  &iface->sockaddr);
 246                         break;
 247                 }
 248                 spin_unlock(&ses->iface_lock);
 249
 250                 left--;
 251                 new_chan_count++;
 252         }
 253
 254         return new_chan_count - old_chan_count;
 255 }
 256
 257 /*
 258  * update the iface for the channel if necessary.
 259  * will return 0 when iface is updated, 1 if removed, 2 otherwise
 260  * Must be called with chan_lock held.
 261  */
 262 int
 263 cifs_chan_update_iface(struct cifs_ses *ses, struct TCP_Server_Info *server)
 264 {
 265         unsigned int chan_index;
 266         struct cifs_server_iface *iface = NULL;
 267         struct cifs_server_iface *old_iface = NULL;
 268         int rc = 0;
 269
 270         spin_lock(&ses->chan_lock);
 271         chan_index = cifs_ses_get_chan_index(ses, server);
 272         if (!chan_index) {
 273                 spin_unlock(&ses->chan_lock);
 274                 return 0;
 275         }
 276
 277         if (ses->chans[chan_index].iface) {
 278                 old_iface = ses->chans[chan_index].iface;
 279                 if (old_iface->is_active) {
 280                         spin_unlock(&ses->chan_lock);
 281                         return 1;
 282                 }
 283         }
 284         spin_unlock(&ses->chan_lock);
 285
 286         spin_lock(&ses->iface_lock);
 287         /* then look for a new one */
 288         list_for_each_entry(iface, &ses->iface_list, iface_head) {
 289                 if (!iface->is_active ||
 290                     (is_ses_using_iface(ses, iface) &&
 291                      !iface->rss_capable)) {
 292                         continue;
 293                 }
 294                 kref_get(&iface->refcount);
 295                 break;
 296         }
 297
 298         if (list_entry_is_head(iface, &ses->iface_list, iface_head)) {
 299                 rc = 1;
 300                 iface = NULL;
 301                 cifs_dbg(FYI, "unable to find a suitable iface\n");
 302         }
 303
 304         /* now drop the ref to the current iface */
 305         if (old_iface && iface) {
 306                 cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",
 307                          &old_iface->sockaddr,
 308                          &iface->sockaddr);
 309                 kref_put(&old_iface->refcount, release_iface);
 310         } else if (old_iface) {
 311                 cifs_dbg(FYI, "releasing ref to iface: %pIS\n",
 312                          &old_iface->sockaddr);
 313                 kref_put(&old_iface->refcount, release_iface);
 314         } else {
 315                 WARN_ON(!iface);
 316                 cifs_dbg(FYI, "adding new iface: %pIS\n", &iface->sockaddr);
 317         }
 318         spin_unlock(&ses->iface_lock);
 319
 320         spin_lock(&ses->chan_lock);
 321         chan_index = cifs_ses_get_chan_index(ses, server);
 322         ses->chans[chan_index].iface = iface;
 323
 324         /* No iface is found. if secondary chan, drop connection */
 325         if (!iface && CIFS_SERVER_IS_CHAN(server))
 326                 ses->chans[chan_index].server = NULL;
 327
 328         spin_unlock(&ses->chan_lock);
 329
 330         if (!iface && CIFS_SERVER_IS_CHAN(server))
 331                 cifs_put_tcp_session(server, false);
 332
 333         return rc;
 334 }
 335
 336 /*
 337  * If server is a channel of ses, return the corresponding enclosing
 338  * cifs_chan otherwise return NULL.
 339  */
 340 struct cifs_chan *
 341 cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server)
 342 {
 343         int i;
 344
 345         spin_lock(&ses->chan_lock);
 346         for (i = 0; i < ses->chan_count; i++) {
 347                 if (ses->chans[i].server == server) {
 348                         spin_unlock(&ses->chan_lock);
 349                         return &ses->chans[i];
 350                 }
 351         }
 352         spin_unlock(&ses->chan_lock);
 353         return NULL;
 354 }
 355
 356 static int
 357 cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 358                      struct cifs_server_iface *iface)
 359 {
 360         struct TCP_Server_Info *chan_server;
 361         struct cifs_chan *chan;
 362         struct smb3_fs_context ctx = {NULL};
 363         static const char unc_fmt[] = "\\%s\\foo";
 364         char unc[sizeof(unc_fmt)+SERVER_NAME_LEN_WITH_NULL] = {0};
 365         struct sockaddr_in *ipv4 = (struct sockaddr_in *)&iface->sockaddr;
 366         struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&iface->sockaddr;
 367         int rc;
 368         unsigned int xid = get_xid();
 369
 370         if (iface->sockaddr.ss_family == AF_INET)
 371                 cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI4)\n",
 372                          ses, iface->speed, iface->rdma_capable ? "yes" : "no",
 373                          &ipv4->sin_addr);
 374         else
 375                 cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI6)\n",
 376                          ses, iface->speed, iface->rdma_capable ? "yes" : "no",
 377                          &ipv6->sin6_addr);
 378
 379         /*
 380          * Setup a ctx with mostly the same info as the existing
 381          * session and overwrite it with the requested iface data.
 382          *
 383          * We need to setup at least the fields used for negprot and
 384          * sesssetup.
 385          *
 386          * We only need the ctx here, so we can reuse memory from
 387          * the session and server without caring about memory
 388          * management.
 389          */
 390
 391         /* Always make new connection for now (TODO?) */
 392         ctx.nosharesock = true;
 393
 394         /* Auth */
 395         ctx.domainauto = ses->domainAuto;
 396         ctx.domainname = ses->domainName;
 397
 398         /* no hostname for extra channels */
 399         ctx.server_hostname = "";
 400
 401         ctx.username = ses->user_name;
 402         ctx.password = ses->password;
 403         ctx.sectype = ses->sectype;
 404         ctx.sign = ses->sign;
 405
 406         /* UNC and paths */
 407         /* XXX: Use ses->server->hostname? */
 408         sprintf(unc, unc_fmt, ses->ip_addr);
 409         ctx.UNC = unc;
 410         ctx.prepath = "";
 411
 412         /* Reuse same version as master connection */
 413         ctx.vals = ses->server->vals;
 414         ctx.ops = ses->server->ops;
 415
 416         ctx.noblocksnd = ses->server->noblocksnd;
 417         ctx.noautotune = ses->server->noautotune;
 418         ctx.sockopt_tcp_nodelay = ses->server->tcp_nodelay;
 419         ctx.echo_interval = ses->server->echo_interval / HZ;
 420         ctx.max_credits = ses->server->max_credits;
 421
 422         /*
 423          * This will be used for encoding/decoding user/domain/pw
 424          * during sess setup auth.
 425          */
 426         ctx.local_nls = cifs_sb->local_nls;
 427
 428         /* Use RDMA if possible */
 429         ctx.rdma = iface->rdma_capable;
 430         memcpy(&ctx.dstaddr, &iface->sockaddr, sizeof(struct sockaddr_storage));
 431
 432         /* reuse master con client guid */
 433         memcpy(&ctx.client_guid, ses->server->client_guid,
 434                SMB2_CLIENT_GUID_SIZE);
 435         ctx.use_client_guid = true;
 436
 437         chan_server = cifs_get_tcp_session(&ctx, ses->server);
 438
 439         spin_lock(&ses->chan_lock);
 440         chan = &ses->chans[ses->chan_count];
 441         chan->server = chan_server;
 442         if (IS_ERR(chan->server)) {
 443                 rc = PTR_ERR(chan->server);
 444                 chan->server = NULL;
 445                 spin_unlock(&ses->chan_lock);
 446                 goto out;
 447         }
 448         chan->iface = iface;
 449         ses->chan_count++;
 450         atomic_set(&ses->chan_seq, 0);
 451
 452         /* Mark this channel as needing connect/setup */
 453         cifs_chan_set_need_reconnect(ses, chan->server);
 454
 455         spin_unlock(&ses->chan_lock);
 456
 457         mutex_lock(&ses->session_mutex);
 458         /*
 459          * We need to allocate the server crypto now as we will need
 460          * to sign packets before we generate the channel signing key
 461          * (we sign with the session key)
 462          */
 463         rc = smb311_crypto_shash_allocate(chan->server);
 464         if (rc) {
 465                 cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
 466                 mutex_unlock(&ses->session_mutex);
 467                 goto out;
 468         }
 469
 470         rc = cifs_negotiate_protocol(xid, ses, chan->server);
 471         if (!rc)
 472                 rc = cifs_setup_session(xid, ses, chan->server, cifs_sb->local_nls);
 473
 474         mutex_unlock(&ses->session_mutex);
 475
 476 out:
 477         if (rc && chan->server) {
 478                 /*
 479                  * we should avoid race with these delayed works before we
 480                  * remove this channel
 481                  */
 482                 cancel_delayed_work_sync(&chan->server->echo);
 483                 cancel_delayed_work_sync(&chan->server->reconnect);
 484
 485                 spin_lock(&ses->chan_lock);
 486                 /* we rely on all bits beyond chan_count to be clear */
 487                 cifs_chan_clear_need_reconnect(ses, chan->server);
 488                 ses->chan_count--;
 489                 /*
 490                  * chan_count should never reach 0 as at least the primary
 491                  * channel is always allocated
 492                  */
 493                 WARN_ON(ses->chan_count < 1);
 494                 spin_unlock(&ses->chan_lock);
 495
 496                 cifs_put_tcp_session(chan->server, 0);
 497         }
 498
 499         free_xid(xid);
 500         return rc;
 501 }
 502
 503 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 504 static __u32 cifs_ssetup_hdr(struct cifs_ses *ses,
 505                              struct TCP_Server_Info *server,
 506                              SESSION_SETUP_ANDX *pSMB)
 507 {
 508         __u32 capabilities = 0;
 509
 510         /* init fields common to all four types of SessSetup */
 511         /* Note that offsets for first seven fields in req struct are same  */
 512         /*      in CIFS Specs so does not matter which of 3 forms of struct */
 513         /*      that we use in next few lines                               */
 514         /* Note that header is initialized to zero in header_assemble */
 515         pSMB->req.AndXCommand = 0xFF;
 516         pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
 517                                         CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
 518                                         USHRT_MAX));
 519         pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq);
 520         pSMB->req.VcNumber = cpu_to_le16(1);
 521
 522         /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */
 523
 524         /* BB verify whether signing required on neg or just on auth frame
 525            (and NTLM case) */
 526
 527         capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
 528                         CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;
 529
 530         if (server->sign)
 531                 pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 532
 533         if (ses->capabilities & CAP_UNICODE) {
 534                 pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
 535                 capabilities |= CAP_UNICODE;
 536         }
 537         if (ses->capabilities & CAP_STATUS32) {
 538                 pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
 539                 capabilities |= CAP_STATUS32;
 540         }
 541         if (ses->capabilities & CAP_DFS) {
 542                 pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
 543                 capabilities |= CAP_DFS;
 544         }
 545         if (ses->capabilities & CAP_UNIX)
 546                 capabilities |= CAP_UNIX;
 547
 548         return capabilities;
 549 }
 550
 551 static void
 552 unicode_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
 553 {
 554         char *bcc_ptr = *pbcc_area;
 555         int bytes_ret = 0;
 556
 557         /* Copy OS version */
 558         bytes_ret = cifs_strtoUTF16((__le16 *)bcc_ptr, "Linux version ", 32,
 559                                     nls_cp);
 560         bcc_ptr += 2 * bytes_ret;
 561         bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, init_utsname()->release,
 562                                     32, nls_cp);
 563         bcc_ptr += 2 * bytes_ret;
 564         bcc_ptr += 2; /* trailing null */
 565
 566         bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
 567                                     32, nls_cp);
 568         bcc_ptr += 2 * bytes_ret;
 569         bcc_ptr += 2; /* trailing null */
 570
 571         *pbcc_area = bcc_ptr;
 572 }
 573
 574 static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
 575                                    const struct nls_table *nls_cp)
 576 {
 577         char *bcc_ptr = *pbcc_area;
 578         int bytes_ret = 0;
 579
 580         /* copy domain */
 581         if (ses->domainName == NULL) {
 582                 /* Sending null domain better than using a bogus domain name (as
 583                 we did briefly in 2.6.18) since server will use its default */
 584                 *bcc_ptr = 0;
 585                 *(bcc_ptr+1) = 0;
 586                 bytes_ret = 0;
 587         } else
 588                 bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,
 589                                             CIFS_MAX_DOMAINNAME_LEN, nls_cp);
 590         bcc_ptr += 2 * bytes_ret;
 591         bcc_ptr += 2;  /* account for null terminator */
 592
 593         *pbcc_area = bcc_ptr;
 594 }
 595
 596 static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
 597                                    const struct nls_table *nls_cp)
 598 {
 599         char *bcc_ptr = *pbcc_area;
 600         int bytes_ret = 0;
 601
 602         /* BB FIXME add check that strings total less
 603         than 335 or will need to send them as arrays */
 604
 605         /* copy user */
 606         if (ses->user_name == NULL) {
 607                 /* null user mount */
 608                 *bcc_ptr = 0;
 609                 *(bcc_ptr+1) = 0;
 610         } else {
 611                 bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->user_name,
 612                                             CIFS_MAX_USERNAME_LEN, nls_cp);
 613         }
 614         bcc_ptr += 2 * bytes_ret;
 615         bcc_ptr += 2; /* account for null termination */
 616
 617         unicode_domain_string(&bcc_ptr, ses, nls_cp);
 618         unicode_oslm_strings(&bcc_ptr, nls_cp);
 619
 620         *pbcc_area = bcc_ptr;
 621 }
 622
 623 static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
 624                                  const struct nls_table *nls_cp)
 625 {
 626         char *bcc_ptr = *pbcc_area;
 627         int len;
 628
 629         /* copy user */
 630         /* BB what about null user mounts - check that we do this BB */
 631         /* copy user */
 632         if (ses->user_name != NULL) {
 633                 len = strscpy(bcc_ptr, ses->user_name, CIFS_MAX_USERNAME_LEN);
 634                 if (WARN_ON_ONCE(len < 0))
 635                         len = CIFS_MAX_USERNAME_LEN - 1;
 636                 bcc_ptr += len;
 637         }
 638         /* else null user mount */
 639         *bcc_ptr = 0;
 640         bcc_ptr++; /* account for null termination */
 641
 642         /* copy domain */
 643         if (ses->domainName != NULL) {
 644                 len = strscpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
 645                 if (WARN_ON_ONCE(len < 0))
 646                         len = CIFS_MAX_DOMAINNAME_LEN - 1;
 647                 bcc_ptr += len;
 648         } /* else we will send a null domain name
 649              so the server will default to its own domain */
 650         *bcc_ptr = 0;
 651         bcc_ptr++;
 652
 653         /* BB check for overflow here */
 654
 655         strcpy(bcc_ptr, "Linux version ");
 656         bcc_ptr += strlen("Linux version ");
 657         strcpy(bcc_ptr, init_utsname()->release);
 658         bcc_ptr += strlen(init_utsname()->release) + 1;
 659
 660         strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
 661         bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;
 662
 663         *pbcc_area = bcc_ptr;
 664 }
 665
 666 static void
 667 decode_unicode_ssetup(char **pbcc_area, int bleft, struct cifs_ses *ses,
 668                       const struct nls_table *nls_cp)
 669 {
 670         int len;
 671         char *data = *pbcc_area;
 672
 673         cifs_dbg(FYI, "bleft %d\n", bleft);
 674
 675         kfree(ses->serverOS);
 676         ses->serverOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 677         cifs_dbg(FYI, "serverOS=%s\n", ses->serverOS);
 678         len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
 679         data += len;
 680         bleft -= len;
 681         if (bleft <= 0)
 682                 return;
 683
 684         kfree(ses->serverNOS);
 685         ses->serverNOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 686         cifs_dbg(FYI, "serverNOS=%s\n", ses->serverNOS);
 687         len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
 688         data += len;
 689         bleft -= len;
 690         if (bleft <= 0)
 691                 return;
 692
 693         kfree(ses->serverDomain);
 694         ses->serverDomain = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 695         cifs_dbg(FYI, "serverDomain=%s\n", ses->serverDomain);
 696
 697         return;
 698 }
 699
 700 static void decode_ascii_ssetup(char **pbcc_area, __u16 bleft,
 701                                 struct cifs_ses *ses,
 702                                 const struct nls_table *nls_cp)
 703 {
 704         int len;
 705         char *bcc_ptr = *pbcc_area;
 706
 707         cifs_dbg(FYI, "decode sessetup ascii. bleft %d\n", bleft);
 708
 709         len = strnlen(bcc_ptr, bleft);
 710         if (len >= bleft)
 711                 return;
 712
 713         kfree(ses->serverOS);
 714
 715         ses->serverOS = kmalloc(len + 1, GFP_KERNEL);
 716         if (ses->serverOS) {
 717                 memcpy(ses->serverOS, bcc_ptr, len);
 718                 ses->serverOS[len] = 0;
 719                 if (strncmp(ses->serverOS, "OS/2", 4) == 0)
 720                         cifs_dbg(FYI, "OS/2 server\n");
 721         }
 722
 723         bcc_ptr += len + 1;
 724         bleft -= len + 1;
 725
 726         len = strnlen(bcc_ptr, bleft);
 727         if (len >= bleft)
 728                 return;
 729
 730         kfree(ses->serverNOS);
 731
 732         ses->serverNOS = kmalloc(len + 1, GFP_KERNEL);
 733         if (ses->serverNOS) {
 734                 memcpy(ses->serverNOS, bcc_ptr, len);
 735                 ses->serverNOS[len] = 0;
 736         }
 737
 738         bcc_ptr += len + 1;
 739         bleft -= len + 1;
 740
 741         len = strnlen(bcc_ptr, bleft);
 742         if (len > bleft)
 743                 return;
 744
 745         /* No domain field in LANMAN case. Domain is
 746            returned by old servers in the SMB negprot response */
 747         /* BB For newer servers which do not support Unicode,
 748            but thus do return domain here we could add parsing
 749            for it later, but it is not very important */
 750         cifs_dbg(FYI, "ascii: bytes left %d\n", bleft);
 751 }
 752 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 753
 754 int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
 755                                     struct cifs_ses *ses)
 756 {
 757         unsigned int tioffset; /* challenge message target info area */
 758         unsigned int tilen; /* challenge message target info area length  */
 759         CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
 760         __u32 server_flags;
 761
 762         if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
 763                 cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len);
 764                 return -EINVAL;
 765         }
 766
 767         if (memcmp(pblob->Signature, "NTLMSSP", 8)) {
 768                 cifs_dbg(VFS, "blob signature incorrect %s\n",
 769                          pblob->Signature);
 770                 return -EINVAL;
 771         }
 772         if (pblob->MessageType != NtLmChallenge) {
 773                 cifs_dbg(VFS, "Incorrect message type %d\n",
 774                          pblob->MessageType);
 775                 return -EINVAL;
 776         }
 777
 778         server_flags = le32_to_cpu(pblob->NegotiateFlags);
 779         cifs_dbg(FYI, "%s: negotiate=0x%08x challenge=0x%08x\n", __func__,
 780                  ses->ntlmssp->client_flags, server_flags);
 781
 782         if ((ses->ntlmssp->client_flags & (NTLMSSP_NEGOTIATE_SEAL | NTLMSSP_NEGOTIATE_SIGN)) &&
 783             (!(server_flags & NTLMSSP_NEGOTIATE_56) && !(server_flags & NTLMSSP_NEGOTIATE_128))) {
 784                 cifs_dbg(VFS, "%s: requested signing/encryption but server did not return either 56-bit or 128-bit session key size\n",
 785                          __func__);
 786                 return -EINVAL;
 787         }
 788         if (!(server_flags & NTLMSSP_NEGOTIATE_NTLM) && !(server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC)) {
 789                 cifs_dbg(VFS, "%s: server does not seem to support either NTLMv1 or NTLMv2\n", __func__);
 790                 return -EINVAL;
 791         }
 792         if (ses->server->sign && !(server_flags & NTLMSSP_NEGOTIATE_SIGN)) {
 793                 cifs_dbg(VFS, "%s: forced packet signing but server does not seem to support it\n",
 794                          __func__);
 795                 return -EOPNOTSUPP;
 796         }
 797         if ((ses->ntlmssp->client_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
 798             !(server_flags & NTLMSSP_NEGOTIATE_KEY_XCH))
 799                 pr_warn_once("%s: authentication has been weakened as server does not support key exchange\n",
 800                              __func__);
 801
 802         ses->ntlmssp->server_flags = server_flags;
 803
 804         memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
 805         /* In particular we can examine sign flags */
 806         /* BB spec says that if AvId field of MsvAvTimestamp is populated then
 807                 we must set the MIC field of the AUTHENTICATE_MESSAGE */
 808
 809         tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
 810         tilen = le16_to_cpu(pblob->TargetInfoArray.Length);
 811         if (tioffset > blob_len || tioffset + tilen > blob_len) {
 812                 cifs_dbg(VFS, "tioffset + tilen too high %u + %u\n",
 813                          tioffset, tilen);
 814                 return -EINVAL;
 815         }
 816         if (tilen) {
 817                 kfree_sensitive(ses->auth_key.response);
 818                 ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
 819                                                  GFP_KERNEL);
 820                 if (!ses->auth_key.response) {
 821                         cifs_dbg(VFS, "Challenge target info alloc failure\n");
 822                         return -ENOMEM;
 823                 }
 824                 ses->auth_key.len = tilen;
 825         }
 826
 827         return 0;
 828 }
 829
 830 static int size_of_ntlmssp_blob(struct cifs_ses *ses, int base_size)
 831 {
 832         int sz = base_size + ses->auth_key.len
 833                 - CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
 834
 835         if (ses->domainName)
 836                 sz += sizeof(__le16) * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
 837         else
 838                 sz += sizeof(__le16);
 839
 840         if (ses->user_name)
 841                 sz += sizeof(__le16) * strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);
 842         else
 843                 sz += sizeof(__le16);
 844
 845         if (ses->workstation_name[0])
 846                 sz += sizeof(__le16) * strnlen(ses->workstation_name,
 847                                                ntlmssp_workstation_name_size(ses));
 848         else
 849                 sz += sizeof(__le16);
 850
 851         return sz;
 852 }
 853
 854 static inline void cifs_security_buffer_from_str(SECURITY_BUFFER *pbuf,
 855                                                  char *str_value,
 856                                                  int str_length,
 857                                                  unsigned char *pstart,
 858                                                  unsigned char **pcur,
 859                                                  const struct nls_table *nls_cp)
 860 {
 861         unsigned char *tmp = pstart;
 862         int len;
 863
 864         if (!pbuf)
 865                 return;
 866
 867         if (!pcur)
 868                 pcur = &tmp;
 869
 870         if (!str_value) {
 871                 pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
 872                 pbuf->Length = 0;
 873                 pbuf->MaximumLength = 0;
 874                 *pcur += sizeof(__le16);
 875         } else {
 876                 len = cifs_strtoUTF16((__le16 *)*pcur,
 877                                       str_value,
 878                                       str_length,
 879                                       nls_cp);
 880                 len *= sizeof(__le16);
 881                 pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
 882                 pbuf->Length = cpu_to_le16(len);
 883                 pbuf->MaximumLength = cpu_to_le16(len);
 884                 *pcur += len;
 885         }
 886 }
 887
 888 /* BB Move to ntlmssp.c eventually */
 889
 890 int build_ntlmssp_negotiate_blob(unsigned char **pbuffer,
 891                                  u16 *buflen,
 892                                  struct cifs_ses *ses,
 893                                  struct TCP_Server_Info *server,
 894                                  const struct nls_table *nls_cp)
 895 {
 896         int rc = 0;
 897         NEGOTIATE_MESSAGE *sec_blob;
 898         __u32 flags;
 899         unsigned char *tmp;
 900         int len;
 901
 902         len = size_of_ntlmssp_blob(ses, sizeof(NEGOTIATE_MESSAGE));
 903         *pbuffer = kmalloc(len, GFP_KERNEL);
 904         if (!*pbuffer) {
 905                 rc = -ENOMEM;
 906                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
 907                 *buflen = 0;
 908                 goto setup_ntlm_neg_ret;
 909         }
 910         sec_blob = (NEGOTIATE_MESSAGE *)*pbuffer;
 911
 912         memset(*pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
 913         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 914         sec_blob->MessageType = NtLmNegotiate;
 915
 916         /* BB is NTLMV2 session security format easier to use here? */
 917         flags = NTLMSSP_NEGOTIATE_56 |  NTLMSSP_REQUEST_TARGET |
 918                 NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 919                 NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
 920                 NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
 921                 NTLMSSP_NEGOTIATE_SIGN;
 922         if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
 923                 flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 924
 925         tmp = *pbuffer + sizeof(NEGOTIATE_MESSAGE);
 926         ses->ntlmssp->client_flags = flags;
 927         sec_blob->NegotiateFlags = cpu_to_le32(flags);
 928
 929         /* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
 930         cifs_security_buffer_from_str(&sec_blob->DomainName,
 931                                       NULL,
 932                                       CIFS_MAX_DOMAINNAME_LEN,
 933                                       *pbuffer, &tmp,
 934                                       nls_cp);
 935
 936         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
 937                                       NULL,
 938                                       CIFS_MAX_WORKSTATION_LEN,
 939                                       *pbuffer, &tmp,
 940                                       nls_cp);
 941
 942         *buflen = tmp - *pbuffer;
 943 setup_ntlm_neg_ret:
 944         return rc;
 945 }
 946
 947 /*
 948  * Build ntlmssp blob with additional fields, such as version,
 949  * supported by modern servers. For safety limit to SMB3 or later
 950  * See notes in MS-NLMP Section 2.2.2.1 e.g.
 951  */
 952 int build_ntlmssp_smb3_negotiate_blob(unsigned char **pbuffer,
 953                                  u16 *buflen,
 954                                  struct cifs_ses *ses,
 955                                  struct TCP_Server_Info *server,
 956                                  const struct nls_table *nls_cp)
 957 {
 958         int rc = 0;
 959         struct negotiate_message *sec_blob;
 960         __u32 flags;
 961         unsigned char *tmp;
 962         int len;
 963
 964         len = size_of_ntlmssp_blob(ses, sizeof(struct negotiate_message));
 965         *pbuffer = kmalloc(len, GFP_KERNEL);
 966         if (!*pbuffer) {
 967                 rc = -ENOMEM;
 968                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
 969                 *buflen = 0;
 970                 goto setup_ntlm_smb3_neg_ret;
 971         }
 972         sec_blob = (struct negotiate_message *)*pbuffer;
 973
 974         memset(*pbuffer, 0, sizeof(struct negotiate_message));
 975         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 976         sec_blob->MessageType = NtLmNegotiate;
 977
 978         /* BB is NTLMV2 session security format easier to use here? */
 979         flags = NTLMSSP_NEGOTIATE_56 |  NTLMSSP_REQUEST_TARGET |
 980                 NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 981                 NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
 982                 NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
 983                 NTLMSSP_NEGOTIATE_SIGN | NTLMSSP_NEGOTIATE_VERSION;
 984         if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
 985                 flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 986
 987         sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
 988         sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
 989         sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
 990         sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
 991
 992         tmp = *pbuffer + sizeof(struct negotiate_message);
 993         ses->ntlmssp->client_flags = flags;
 994         sec_blob->NegotiateFlags = cpu_to_le32(flags);
 995
 996         /* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
 997         cifs_security_buffer_from_str(&sec_blob->DomainName,
 998                                       NULL,
 999                                       CIFS_MAX_DOMAINNAME_LEN,
1000                                       *pbuffer, &tmp,
1001                                       nls_cp);
1002
1003         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1004                                       NULL,
1005                                       CIFS_MAX_WORKSTATION_LEN,
1006                                       *pbuffer, &tmp,
1007                                       nls_cp);
1008
1009         *buflen = tmp - *pbuffer;
1010 setup_ntlm_smb3_neg_ret:
1011         return rc;
1012 }
1013
1014
1015 int build_ntlmssp_auth_blob(unsigned char **pbuffer,
1016                                         u16 *buflen,
1017                                    struct cifs_ses *ses,
1018                                    struct TCP_Server_Info *server,
1019                                    const struct nls_table *nls_cp)
1020 {
1021         int rc;
1022         AUTHENTICATE_MESSAGE *sec_blob;
1023         __u32 flags;
1024         unsigned char *tmp;
1025         int len;
1026
1027         rc = setup_ntlmv2_rsp(ses, nls_cp);
1028         if (rc) {
1029                 cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
1030                 *buflen = 0;
1031                 goto setup_ntlmv2_ret;
1032         }
1033
1034         len = size_of_ntlmssp_blob(ses, sizeof(AUTHENTICATE_MESSAGE));
1035         *pbuffer = kmalloc(len, GFP_KERNEL);
1036         if (!*pbuffer) {
1037                 rc = -ENOMEM;
1038                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1039                 *buflen = 0;
1040                 goto setup_ntlmv2_ret;
1041         }
1042         sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
1043
1044         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1045         sec_blob->MessageType = NtLmAuthenticate;
1046
1047         flags = ses->ntlmssp->server_flags | NTLMSSP_REQUEST_TARGET |
1048                 NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED;
1049
1050         tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
1051         sec_blob->NegotiateFlags = cpu_to_le32(flags);
1052
1053         sec_blob->LmChallengeResponse.BufferOffset =
1054                                 cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
1055         sec_blob->LmChallengeResponse.Length = 0;
1056         sec_blob->LmChallengeResponse.MaximumLength = 0;
1057
1058         sec_blob->NtChallengeResponse.BufferOffset =
1059                                 cpu_to_le32(tmp - *pbuffer);
1060         if (ses->user_name != NULL) {
1061                 memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1062                                 ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1063                 tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1064
1065                 sec_blob->NtChallengeResponse.Length =
1066                                 cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1067                 sec_blob->NtChallengeResponse.MaximumLength =
1068                                 cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1069         } else {
1070                 /*
1071                  * don't send an NT Response for anonymous access
1072                  */
1073                 sec_blob->NtChallengeResponse.Length = 0;
1074                 sec_blob->NtChallengeResponse.MaximumLength = 0;
1075         }
1076
1077         cifs_security_buffer_from_str(&sec_blob->DomainName,
1078                                       ses->domainName,
1079                                       CIFS_MAX_DOMAINNAME_LEN,
1080                                       *pbuffer, &tmp,
1081                                       nls_cp);
1082
1083         cifs_security_buffer_from_str(&sec_blob->UserName,
1084                                       ses->user_name,
1085                                       CIFS_MAX_USERNAME_LEN,
1086                                       *pbuffer, &tmp,
1087                                       nls_cp);
1088
1089         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1090                                       ses->workstation_name,
1091                                       ntlmssp_workstation_name_size(ses),
1092                                       *pbuffer, &tmp,
1093                                       nls_cp);
1094
1095         if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
1096             (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) &&
1097             !calc_seckey(ses)) {
1098                 memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
1099                 sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1100                 sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
1101                 sec_blob->SessionKey.MaximumLength =
1102                                 cpu_to_le16(CIFS_CPHTXT_SIZE);
1103                 tmp += CIFS_CPHTXT_SIZE;
1104         } else {
1105                 sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1106                 sec_blob->SessionKey.Length = 0;
1107                 sec_blob->SessionKey.MaximumLength = 0;
1108         }
1109
1110         *buflen = tmp - *pbuffer;
1111 setup_ntlmv2_ret:
1112         return rc;
1113 }
1114
1115 enum securityEnum
1116 cifs_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
1117 {
1118         switch (server->negflavor) {
1119         case CIFS_NEGFLAVOR_EXTENDED:
1120                 switch (requested) {
1121                 case Kerberos:
1122                 case RawNTLMSSP:
1123                         return requested;
1124                 case Unspecified:
1125                         if (server->sec_ntlmssp &&
1126                             (global_secflags & CIFSSEC_MAY_NTLMSSP))
1127                                 return RawNTLMSSP;
1128                         if ((server->sec_kerberos || server->sec_mskerberos) &&
1129                             (global_secflags & CIFSSEC_MAY_KRB5))
1130                                 return Kerberos;
1131                         fallthrough;
1132                 default:
1133                         return Unspecified;
1134                 }
1135         case CIFS_NEGFLAVOR_UNENCAP:
1136                 switch (requested) {
1137                 case NTLMv2:
1138                         return requested;
1139                 case Unspecified:
1140                         if (global_secflags & CIFSSEC_MAY_NTLMV2)
1141                                 return NTLMv2;
1142                         break;
1143                 default:
1144                         break;
1145                 }
1146                 fallthrough;
1147         default:
1148                 return Unspecified;
1149         }
1150 }
1151
1152 struct sess_data {
1153         unsigned int xid;
1154         struct cifs_ses *ses;
1155         struct TCP_Server_Info *server;
1156         struct nls_table *nls_cp;
1157         void (*func)(struct sess_data *);
1158         int result;
1159
1160         /* we will send the SMB in three pieces:
1161          * a fixed length beginning part, an optional
1162          * SPNEGO blob (which can be zero length), and a
1163          * last part which will include the strings
1164          * and rest of bcc area. This allows us to avoid
1165          * a large buffer 17K allocation
1166          */
1167         int buf0_type;
1168         struct kvec iov[3];
1169 };
1170
1171 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
1172 static int
1173 sess_alloc_buffer(struct sess_data *sess_data, int wct)
1174 {
1175         int rc;
1176         struct cifs_ses *ses = sess_data->ses;
1177         struct smb_hdr *smb_buf;
1178
1179         rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
1180                                   (void **)&smb_buf);
1181
1182         if (rc)
1183                 return rc;
1184
1185         sess_data->iov[0].iov_base = (char *)smb_buf;
1186         sess_data->iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
1187         /*
1188          * This variable will be used to clear the buffer
1189          * allocated above in case of any error in the calling function.
1190          */
1191         sess_data->buf0_type = CIFS_SMALL_BUFFER;
1192
1193         /* 2000 big enough to fit max user, domain, NOS name etc. */
1194         sess_data->iov[2].iov_base = kmalloc(2000, GFP_KERNEL);
1195         if (!sess_data->iov[2].iov_base) {
1196                 rc = -ENOMEM;
1197                 goto out_free_smb_buf;
1198         }
1199
1200         return 0;
1201
1202 out_free_smb_buf:
1203         cifs_small_buf_release(smb_buf);
1204         sess_data->iov[0].iov_base = NULL;
1205         sess_data->iov[0].iov_len = 0;
1206         sess_data->buf0_type = CIFS_NO_BUFFER;
1207         return rc;
1208 }
1209
1210 static void
1211 sess_free_buffer(struct sess_data *sess_data)
1212 {
1213         struct kvec *iov = sess_data->iov;
1214
1215         /*
1216          * Zero the session data before freeing, as it might contain sensitive info (keys, etc).
1217          * Note that iov[1] is already freed by caller.
1218          */
1219         if (sess_data->buf0_type != CIFS_NO_BUFFER && iov[0].iov_base)
1220                 memzero_explicit(iov[0].iov_base, iov[0].iov_len);
1221
1222         free_rsp_buf(sess_data->buf0_type, iov[0].iov_base);
1223         sess_data->buf0_type = CIFS_NO_BUFFER;
1224         kfree_sensitive(iov[2].iov_base);
1225 }
1226
1227 static int
1228 sess_establish_session(struct sess_data *sess_data)
1229 {
1230         struct cifs_ses *ses = sess_data->ses;
1231         struct TCP_Server_Info *server = sess_data->server;
1232
1233         cifs_server_lock(server);
1234         if (!server->session_estab) {
1235                 if (server->sign) {
1236                         server->session_key.response =
1237                                 kmemdup(ses->auth_key.response,
1238                                 ses->auth_key.len, GFP_KERNEL);
1239                         if (!server->session_key.response) {
1240                                 cifs_server_unlock(server);
1241                                 return -ENOMEM;
1242                         }
1243                         server->session_key.len =
1244                                                 ses->auth_key.len;
1245                 }
1246                 server->sequence_number = 0x2;
1247                 server->session_estab = true;
1248         }
1249         cifs_server_unlock(server);
1250
1251         cifs_dbg(FYI, "CIFS session established successfully\n");
1252         return 0;
1253 }
1254
1255 static int
1256 sess_sendreceive(struct sess_data *sess_data)
1257 {
1258         int rc;
1259         struct smb_hdr *smb_buf = (struct smb_hdr *) sess_data->iov[0].iov_base;
1260         __u16 count;
1261         struct kvec rsp_iov = { NULL, 0 };
1262
1263         count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
1264         be32_add_cpu(&smb_buf->smb_buf_length, count);
1265         put_bcc(count, smb_buf);
1266
1267         rc = SendReceive2(sess_data->xid, sess_data->ses,
1268                           sess_data->iov, 3 /* num_iovecs */,
1269                           &sess_data->buf0_type,
1270                           CIFS_LOG_ERROR, &rsp_iov);
1271         cifs_small_buf_release(sess_data->iov[0].iov_base);
1272         memcpy(&sess_data->iov[0], &rsp_iov, sizeof(struct kvec));
1273
1274         return rc;
1275 }
1276
1277 static void
1278 sess_auth_ntlmv2(struct sess_data *sess_data)
1279 {
1280         int rc = 0;
1281         struct smb_hdr *smb_buf;
1282         SESSION_SETUP_ANDX *pSMB;
1283         char *bcc_ptr;
1284         struct cifs_ses *ses = sess_data->ses;
1285         struct TCP_Server_Info *server = sess_data->server;
1286         __u32 capabilities;
1287         __u16 bytes_remaining;
1288
1289         /* old style NTLM sessionsetup */
1290         /* wct = 13 */
1291         rc = sess_alloc_buffer(sess_data, 13);
1292         if (rc)
1293                 goto out;
1294
1295         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1296         bcc_ptr = sess_data->iov[2].iov_base;
1297         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1298
1299         pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
1300
1301         /* LM2 password would be here if we supported it */
1302         pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
1303
1304         if (ses->user_name != NULL) {
1305                 /* calculate nlmv2 response and session key */
1306                 rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
1307                 if (rc) {
1308                         cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n", rc);
1309                         goto out;
1310                 }
1311
1312                 memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1313                                 ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1314                 bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1315
1316                 /* set case sensitive password length after tilen may get
1317                  * assigned, tilen is 0 otherwise.
1318                  */
1319                 pSMB->req_no_secext.CaseSensitivePasswordLength =
1320                         cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1321         } else {
1322                 pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
1323         }
1324
1325         if (ses->capabilities & CAP_UNICODE) {
1326                 if (!IS_ALIGNED(sess_data->iov[0].iov_len, 2)) {
1327                         *bcc_ptr = 0;
1328                         bcc_ptr++;
1329                 }
1330                 unicode_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1331         } else {
1332                 ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1333         }
1334
1335
1336         sess_data->iov[2].iov_len = (long) bcc_ptr -
1337                         (long) sess_data->iov[2].iov_base;
1338
1339         rc = sess_sendreceive(sess_data);
1340         if (rc)
1341                 goto out;
1342
1343         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1344         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1345
1346         if (smb_buf->WordCount != 3) {
1347                 rc = -EIO;
1348                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1349                 goto out;
1350         }
1351
1352         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1353                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1354
1355         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1356         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1357
1358         bytes_remaining = get_bcc(smb_buf);
1359         bcc_ptr = pByteArea(smb_buf);
1360
1361         /* BB check if Unicode and decode strings */
1362         if (bytes_remaining == 0) {
1363                 /* no string area to decode, do nothing */
1364         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1365                 /* unicode string area must be word-aligned */
1366                 if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1367                         ++bcc_ptr;
1368                         --bytes_remaining;
1369                 }
1370                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1371                                       sess_data->nls_cp);
1372         } else {
1373                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1374                                     sess_data->nls_cp);
1375         }
1376
1377         rc = sess_establish_session(sess_data);
1378 out:
1379         sess_data->result = rc;
1380         sess_data->func = NULL;
1381         sess_free_buffer(sess_data);
1382         kfree_sensitive(ses->auth_key.response);
1383         ses->auth_key.response = NULL;
1384 }
1385
1386 #ifdef CONFIG_CIFS_UPCALL
1387 static void
1388 sess_auth_kerberos(struct sess_data *sess_data)
1389 {
1390         int rc = 0;
1391         struct smb_hdr *smb_buf;
1392         SESSION_SETUP_ANDX *pSMB;
1393         char *bcc_ptr;
1394         struct cifs_ses *ses = sess_data->ses;
1395         struct TCP_Server_Info *server = sess_data->server;
1396         __u32 capabilities;
1397         __u16 bytes_remaining;
1398         struct key *spnego_key = NULL;
1399         struct cifs_spnego_msg *msg;
1400         u16 blob_len;
1401
1402         /* extended security */
1403         /* wct = 12 */
1404         rc = sess_alloc_buffer(sess_data, 12);
1405         if (rc)
1406                 goto out;
1407
1408         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1409         bcc_ptr = sess_data->iov[2].iov_base;
1410         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1411
1412         spnego_key = cifs_get_spnego_key(ses, server);
1413         if (IS_ERR(spnego_key)) {
1414                 rc = PTR_ERR(spnego_key);
1415                 spnego_key = NULL;
1416                 goto out;
1417         }
1418
1419         msg = spnego_key->payload.data[0];
1420         /*
1421          * check version field to make sure that cifs.upcall is
1422          * sending us a response in an expected form
1423          */
1424         if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
1425                 cifs_dbg(VFS, "incorrect version of cifs.upcall (expected %d but got %d)\n",
1426                          CIFS_SPNEGO_UPCALL_VERSION, msg->version);
1427                 rc = -EKEYREJECTED;
1428                 goto out_put_spnego_key;
1429         }
1430
1431         kfree_sensitive(ses->auth_key.response);
1432         ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
1433                                          GFP_KERNEL);
1434         if (!ses->auth_key.response) {
1435                 cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory\n",
1436                          msg->sesskey_len);
1437                 rc = -ENOMEM;
1438                 goto out_put_spnego_key;
1439         }
1440         ses->auth_key.len = msg->sesskey_len;
1441
1442         pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1443         capabilities |= CAP_EXTENDED_SECURITY;
1444         pSMB->req.Capabilities = cpu_to_le32(capabilities);
1445         sess_data->iov[1].iov_base = msg->data + msg->sesskey_len;
1446         sess_data->iov[1].iov_len = msg->secblob_len;
1447         pSMB->req.SecurityBlobLength = cpu_to_le16(sess_data->iov[1].iov_len);
1448
1449         if (ses->capabilities & CAP_UNICODE) {
1450                 /* unicode strings must be word aligned */
1451                 if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1452                         *bcc_ptr = 0;
1453                         bcc_ptr++;
1454                 }
1455                 unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1456                 unicode_domain_string(&bcc_ptr, ses, sess_data->nls_cp);
1457         } else {
1458                 /* BB: is this right? */
1459                 ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1460         }
1461
1462         sess_data->iov[2].iov_len = (long) bcc_ptr -
1463                         (long) sess_data->iov[2].iov_base;
1464
1465         rc = sess_sendreceive(sess_data);
1466         if (rc)
1467                 goto out_put_spnego_key;
1468
1469         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1470         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1471
1472         if (smb_buf->WordCount != 4) {
1473                 rc = -EIO;
1474                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1475                 goto out_put_spnego_key;
1476         }
1477
1478         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1479                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1480
1481         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1482         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1483
1484         bytes_remaining = get_bcc(smb_buf);
1485         bcc_ptr = pByteArea(smb_buf);
1486
1487         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1488         if (blob_len > bytes_remaining) {
1489                 cifs_dbg(VFS, "bad security blob length %d\n",
1490                                 blob_len);
1491                 rc = -EINVAL;
1492                 goto out_put_spnego_key;
1493         }
1494         bcc_ptr += blob_len;
1495         bytes_remaining -= blob_len;
1496
1497         /* BB check if Unicode and decode strings */
1498         if (bytes_remaining == 0) {
1499                 /* no string area to decode, do nothing */
1500         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1501                 /* unicode string area must be word-aligned */
1502                 if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1503                         ++bcc_ptr;
1504                         --bytes_remaining;
1505                 }
1506                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1507                                       sess_data->nls_cp);
1508         } else {
1509                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1510                                     sess_data->nls_cp);
1511         }
1512
1513         rc = sess_establish_session(sess_data);
1514 out_put_spnego_key:
1515         key_invalidate(spnego_key);
1516         key_put(spnego_key);
1517 out:
1518         sess_data->result = rc;
1519         sess_data->func = NULL;
1520         sess_free_buffer(sess_data);
1521         kfree_sensitive(ses->auth_key.response);
1522         ses->auth_key.response = NULL;
1523 }
1524
1525 #endif /* ! CONFIG_CIFS_UPCALL */
1526
1527 /*
1528  * The required kvec buffers have to be allocated before calling this
1529  * function.
1530  */
1531 static int
1532 _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)
1533 {
1534         SESSION_SETUP_ANDX *pSMB;
1535         struct cifs_ses *ses = sess_data->ses;
1536         struct TCP_Server_Info *server = sess_data->server;
1537         __u32 capabilities;
1538         char *bcc_ptr;
1539
1540         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1541
1542         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1543         if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
1544                 cifs_dbg(VFS, "NTLMSSP requires Unicode support\n");
1545                 return -ENOSYS;
1546         }
1547
1548         pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1549         capabilities |= CAP_EXTENDED_SECURITY;
1550         pSMB->req.Capabilities |= cpu_to_le32(capabilities);
1551
1552         bcc_ptr = sess_data->iov[2].iov_base;
1553         /* unicode strings must be word aligned */
1554         if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1555                 *bcc_ptr = 0;
1556                 bcc_ptr++;
1557         }
1558         unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1559
1560         sess_data->iov[2].iov_len = (long) bcc_ptr -
1561                                         (long) sess_data->iov[2].iov_base;
1562
1563         return 0;
1564 }
1565
1566 static void
1567 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data);
1568
1569 static void
1570 sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data)
1571 {
1572         int rc;
1573         struct smb_hdr *smb_buf;
1574         SESSION_SETUP_ANDX *pSMB;
1575         struct cifs_ses *ses = sess_data->ses;
1576         struct TCP_Server_Info *server = sess_data->server;
1577         __u16 bytes_remaining;
1578         char *bcc_ptr;
1579         unsigned char *ntlmsspblob = NULL;
1580         u16 blob_len;
1581
1582         cifs_dbg(FYI, "rawntlmssp session setup negotiate phase\n");
1583
1584         /*
1585          * if memory allocation is successful, caller of this function
1586          * frees it.
1587          */
1588         ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
1589         if (!ses->ntlmssp) {
1590                 rc = -ENOMEM;
1591                 goto out;
1592         }
1593         ses->ntlmssp->sesskey_per_smbsess = false;
1594
1595         /* wct = 12 */
1596         rc = sess_alloc_buffer(sess_data, 12);
1597         if (rc)
1598                 goto out;
1599
1600         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1601
1602         /* Build security blob before we assemble the request */
1603         rc = build_ntlmssp_negotiate_blob(&ntlmsspblob,
1604                                      &blob_len, ses, server,
1605                                      sess_data->nls_cp);
1606         if (rc)
1607                 goto out_free_ntlmsspblob;
1608
1609         sess_data->iov[1].iov_len = blob_len;
1610         sess_data->iov[1].iov_base = ntlmsspblob;
1611         pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1612
1613         rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1614         if (rc)
1615                 goto out_free_ntlmsspblob;
1616
1617         rc = sess_sendreceive(sess_data);
1618
1619         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1620         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1621
1622         /* If true, rc here is expected and not an error */
1623         if (sess_data->buf0_type != CIFS_NO_BUFFER &&
1624             smb_buf->Status.CifsError ==
1625                         cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
1626                 rc = 0;
1627
1628         if (rc)
1629                 goto out_free_ntlmsspblob;
1630
1631         cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");
1632
1633         if (smb_buf->WordCount != 4) {
1634                 rc = -EIO;
1635                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1636                 goto out_free_ntlmsspblob;
1637         }
1638
1639         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1640         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1641
1642         bytes_remaining = get_bcc(smb_buf);
1643         bcc_ptr = pByteArea(smb_buf);
1644
1645         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1646         if (blob_len > bytes_remaining) {
1647                 cifs_dbg(VFS, "bad security blob length %d\n",
1648                                 blob_len);
1649                 rc = -EINVAL;
1650                 goto out_free_ntlmsspblob;
1651         }
1652
1653         rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
1654
1655 out_free_ntlmsspblob:
1656         kfree_sensitive(ntlmsspblob);
1657 out:
1658         sess_free_buffer(sess_data);
1659
1660         if (!rc) {
1661                 sess_data->func = sess_auth_rawntlmssp_authenticate;
1662                 return;
1663         }
1664
1665         /* Else error. Cleanup */
1666         kfree_sensitive(ses->auth_key.response);
1667         ses->auth_key.response = NULL;
1668         kfree_sensitive(ses->ntlmssp);
1669         ses->ntlmssp = NULL;
1670
1671         sess_data->func = NULL;
1672         sess_data->result = rc;
1673 }
1674
1675 static void
1676 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
1677 {
1678         int rc;
1679         struct smb_hdr *smb_buf;
1680         SESSION_SETUP_ANDX *pSMB;
1681         struct cifs_ses *ses = sess_data->ses;
1682         struct TCP_Server_Info *server = sess_data->server;
1683         __u16 bytes_remaining;
1684         char *bcc_ptr;
1685         unsigned char *ntlmsspblob = NULL;
1686         u16 blob_len;
1687
1688         cifs_dbg(FYI, "rawntlmssp session setup authenticate phase\n");
1689
1690         /* wct = 12 */
1691         rc = sess_alloc_buffer(sess_data, 12);
1692         if (rc)
1693                 goto out;
1694
1695         /* Build security blob before we assemble the request */
1696         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1697         smb_buf = (struct smb_hdr *)pSMB;
1698         rc = build_ntlmssp_auth_blob(&ntlmsspblob,
1699                                         &blob_len, ses, server,
1700                                         sess_data->nls_cp);
1701         if (rc)
1702                 goto out_free_ntlmsspblob;
1703         sess_data->iov[1].iov_len = blob_len;
1704         sess_data->iov[1].iov_base = ntlmsspblob;
1705         pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1706         /*
1707          * Make sure that we tell the server that we are using
1708          * the uid that it just gave us back on the response
1709          * (challenge)
1710          */
1711         smb_buf->Uid = ses->Suid;
1712
1713         rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1714         if (rc)
1715                 goto out_free_ntlmsspblob;
1716
1717         rc = sess_sendreceive(sess_data);
1718         if (rc)
1719                 goto out_free_ntlmsspblob;
1720
1721         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1722         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1723         if (smb_buf->WordCount != 4) {
1724                 rc = -EIO;
1725                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1726                 goto out_free_ntlmsspblob;
1727         }
1728
1729         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1730                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1731
1732         if (ses->Suid != smb_buf->Uid) {
1733                 ses->Suid = smb_buf->Uid;
1734                 cifs_dbg(FYI, "UID changed! new UID = %llu\n", ses->Suid);
1735         }
1736
1737         bytes_remaining = get_bcc(smb_buf);
1738         bcc_ptr = pByteArea(smb_buf);
1739         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1740         if (blob_len > bytes_remaining) {
1741                 cifs_dbg(VFS, "bad security blob length %d\n",
1742                                 blob_len);
1743                 rc = -EINVAL;
1744                 goto out_free_ntlmsspblob;
1745         }
1746         bcc_ptr += blob_len;
1747         bytes_remaining -= blob_len;
1748
1749
1750         /* BB check if Unicode and decode strings */
1751         if (bytes_remaining == 0) {
1752                 /* no string area to decode, do nothing */
1753         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1754                 /* unicode string area must be word-aligned */
1755                 if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1756                         ++bcc_ptr;
1757                         --bytes_remaining;
1758                 }
1759                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1760                                       sess_data->nls_cp);
1761         } else {
1762                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1763                                     sess_data->nls_cp);
1764         }
1765
1766 out_free_ntlmsspblob:
1767         kfree_sensitive(ntlmsspblob);
1768 out:
1769         sess_free_buffer(sess_data);
1770
1771         if (!rc)
1772                 rc = sess_establish_session(sess_data);
1773
1774         /* Cleanup */
1775         kfree_sensitive(ses->auth_key.response);
1776         ses->auth_key.response = NULL;
1777         kfree_sensitive(ses->ntlmssp);
1778         ses->ntlmssp = NULL;
1779
1780         sess_data->func = NULL;
1781         sess_data->result = rc;
1782 }
1783
1784 static int select_sec(struct sess_data *sess_data)
1785 {
1786         int type;
1787         struct cifs_ses *ses = sess_data->ses;
1788         struct TCP_Server_Info *server = sess_data->server;
1789
1790         type = cifs_select_sectype(server, ses->sectype);
1791         cifs_dbg(FYI, "sess setup type %d\n", type);
1792         if (type == Unspecified) {
1793                 cifs_dbg(VFS, "Unable to select appropriate authentication method!\n");
1794                 return -EINVAL;
1795         }
1796
1797         switch (type) {
1798         case NTLMv2:
1799                 sess_data->func = sess_auth_ntlmv2;
1800                 break;
1801         case Kerberos:
1802 #ifdef CONFIG_CIFS_UPCALL
1803                 sess_data->func = sess_auth_kerberos;
1804                 break;
1805 #else
1806                 cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
1807                 return -ENOSYS;
1808 #endif /* CONFIG_CIFS_UPCALL */
1809         case RawNTLMSSP:
1810                 sess_data->func = sess_auth_rawntlmssp_negotiate;
1811                 break;
1812         default:
1813                 cifs_dbg(VFS, "secType %d not supported!\n", type);
1814                 return -ENOSYS;
1815         }
1816
1817         return 0;
1818 }
1819
1820 int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
1821                    struct TCP_Server_Info *server,
1822                    const struct nls_table *nls_cp)
1823 {
1824         int rc = 0;
1825         struct sess_data *sess_data;
1826
1827         if (ses == NULL) {
1828                 WARN(1, "%s: ses == NULL!", __func__);
1829                 return -EINVAL;
1830         }
1831
1832         sess_data = kzalloc(sizeof(struct sess_data), GFP_KERNEL);
1833         if (!sess_data)
1834                 return -ENOMEM;
1835
1836         sess_data->xid = xid;
1837         sess_data->ses = ses;
1838         sess_data->server = server;
1839         sess_data->buf0_type = CIFS_NO_BUFFER;
1840         sess_data->nls_cp = (struct nls_table *) nls_cp;
1841
1842         rc = select_sec(sess_data);
1843         if (rc)
1844                 goto out;
1845
1846         while (sess_data->func)
1847                 sess_data->func(sess_data);
1848
1849         /* Store result before we free sess_data */
1850         rc = sess_data->result;
1851
1852 out:
1853         kfree_sensitive(sess_data);
1854         return rc;
1855 }
1856 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */