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 ([email protected])
   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         }
 296
 297         if (!list_entry_is_head(iface, &ses->iface_list, iface_head)) {
 298                 rc = 1;
 299                 iface = NULL;
 300                 cifs_dbg(FYI, "unable to find a suitable iface\n");
 301         }
 302
 303         /* now drop the ref to the current iface */
 304         if (old_iface && iface) {
 305                 cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",
 306                          &old_iface->sockaddr,
 307                          &iface->sockaddr);
 308                 kref_put(&old_iface->refcount, release_iface);
 309         } else if (old_iface) {
 310                 cifs_dbg(FYI, "releasing ref to iface: %pIS\n",
 311                          &old_iface->sockaddr);
 312                 kref_put(&old_iface->refcount, release_iface);
 313         } else {
 314                 WARN_ON(!iface);
 315                 cifs_dbg(FYI, "adding new iface: %pIS\n", &iface->sockaddr);
 316         }
 317         spin_unlock(&ses->iface_lock);
 318
 319         spin_lock(&ses->chan_lock);
 320         chan_index = cifs_ses_get_chan_index(ses, server);
 321         ses->chans[chan_index].iface = iface;
 322
 323         /* No iface is found. if secondary chan, drop connection */
 324         if (!iface && CIFS_SERVER_IS_CHAN(server))
 325                 ses->chans[chan_index].server = NULL;
 326
 327         spin_unlock(&ses->chan_lock);
 328
 329         if (!iface && CIFS_SERVER_IS_CHAN(server))
 330                 cifs_put_tcp_session(server, false);
 331
 332         return rc;
 333 }
 334
 335 /*
 336  * If server is a channel of ses, return the corresponding enclosing
 337  * cifs_chan otherwise return NULL.
 338  */
 339 struct cifs_chan *
 340 cifs_ses_find_chan(struct cifs_ses *ses, struct TCP_Server_Info *server)
 341 {
 342         int i;
 343
 344         spin_lock(&ses->chan_lock);
 345         for (i = 0; i < ses->chan_count; i++) {
 346                 if (ses->chans[i].server == server) {
 347                         spin_unlock(&ses->chan_lock);
 348                         return &ses->chans[i];
 349                 }
 350         }
 351         spin_unlock(&ses->chan_lock);
 352         return NULL;
 353 }
 354
 355 static int
 356 cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 357                      struct cifs_server_iface *iface)
 358 {
 359         struct TCP_Server_Info *chan_server;
 360         struct cifs_chan *chan;
 361         struct smb3_fs_context ctx = {NULL};
 362         static const char unc_fmt[] = "\\%s\\foo";
 363         char unc[sizeof(unc_fmt)+SERVER_NAME_LEN_WITH_NULL] = {0};
 364         struct sockaddr_in *ipv4 = (struct sockaddr_in *)&iface->sockaddr;
 365         struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&iface->sockaddr;
 366         int rc;
 367         unsigned int xid = get_xid();
 368
 369         if (iface->sockaddr.ss_family == AF_INET)
 370                 cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI4)\n",
 371                          ses, iface->speed, iface->rdma_capable ? "yes" : "no",
 372                          &ipv4->sin_addr);
 373         else
 374                 cifs_dbg(FYI, "adding channel to ses %p (speed:%zu bps rdma:%s ip:%pI6)\n",
 375                          ses, iface->speed, iface->rdma_capable ? "yes" : "no",
 376                          &ipv6->sin6_addr);
 377
 378         /*
 379          * Setup a ctx with mostly the same info as the existing
 380          * session and overwrite it with the requested iface data.
 381          *
 382          * We need to setup at least the fields used for negprot and
 383          * sesssetup.
 384          *
 385          * We only need the ctx here, so we can reuse memory from
 386          * the session and server without caring about memory
 387          * management.
 388          */
 389
 390         /* Always make new connection for now (TODO?) */
 391         ctx.nosharesock = true;
 392
 393         /* Auth */
 394         ctx.domainauto = ses->domainAuto;
 395         ctx.domainname = ses->domainName;
 396
 397         /* no hostname for extra channels */
 398         ctx.server_hostname = "";
 399
 400         ctx.username = ses->user_name;
 401         ctx.password = ses->password;
 402         ctx.sectype = ses->sectype;
 403         ctx.sign = ses->sign;
 404
 405         /* UNC and paths */
 406         /* XXX: Use ses->server->hostname? */
 407         sprintf(unc, unc_fmt, ses->ip_addr);
 408         ctx.UNC = unc;
 409         ctx.prepath = "";
 410
 411         /* Reuse same version as master connection */
 412         ctx.vals = ses->server->vals;
 413         ctx.ops = ses->server->ops;
 414
 415         ctx.noblocksnd = ses->server->noblocksnd;
 416         ctx.noautotune = ses->server->noautotune;
 417         ctx.sockopt_tcp_nodelay = ses->server->tcp_nodelay;
 418         ctx.echo_interval = ses->server->echo_interval / HZ;
 419         ctx.max_credits = ses->server->max_credits;
 420
 421         /*
 422          * This will be used for encoding/decoding user/domain/pw
 423          * during sess setup auth.
 424          */
 425         ctx.local_nls = cifs_sb->local_nls;
 426
 427         /* Use RDMA if possible */
 428         ctx.rdma = iface->rdma_capable;
 429         memcpy(&ctx.dstaddr, &iface->sockaddr, sizeof(struct sockaddr_storage));
 430
 431         /* reuse master con client guid */
 432         memcpy(&ctx.client_guid, ses->server->client_guid,
 433                SMB2_CLIENT_GUID_SIZE);
 434         ctx.use_client_guid = true;
 435
 436         chan_server = cifs_get_tcp_session(&ctx, ses->server);
 437
 438         spin_lock(&ses->chan_lock);
 439         chan = &ses->chans[ses->chan_count];
 440         chan->server = chan_server;
 441         if (IS_ERR(chan->server)) {
 442                 rc = PTR_ERR(chan->server);
 443                 chan->server = NULL;
 444                 spin_unlock(&ses->chan_lock);
 445                 goto out;
 446         }
 447         chan->iface = iface;
 448         ses->chan_count++;
 449         atomic_set(&ses->chan_seq, 0);
 450
 451         /* Mark this channel as needing connect/setup */
 452         cifs_chan_set_need_reconnect(ses, chan->server);
 453
 454         spin_unlock(&ses->chan_lock);
 455
 456         mutex_lock(&ses->session_mutex);
 457         /*
 458          * We need to allocate the server crypto now as we will need
 459          * to sign packets before we generate the channel signing key
 460          * (we sign with the session key)
 461          */
 462         rc = smb311_crypto_shash_allocate(chan->server);
 463         if (rc) {
 464                 cifs_dbg(VFS, "%s: crypto alloc failed\n", __func__);
 465                 mutex_unlock(&ses->session_mutex);
 466                 goto out;
 467         }
 468
 469         rc = cifs_negotiate_protocol(xid, ses, chan->server);
 470         if (!rc)
 471                 rc = cifs_setup_session(xid, ses, chan->server, cifs_sb->local_nls);
 472
 473         mutex_unlock(&ses->session_mutex);
 474
 475 out:
 476         if (rc && chan->server) {
 477                 /*
 478                  * we should avoid race with these delayed works before we
 479                  * remove this channel
 480                  */
 481                 cancel_delayed_work_sync(&chan->server->echo);
 482                 cancel_delayed_work_sync(&chan->server->resolve);
 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                 ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
 818                                                  GFP_KERNEL);
 819                 if (!ses->auth_key.response) {
 820                         cifs_dbg(VFS, "Challenge target info alloc failure\n");
 821                         return -ENOMEM;
 822                 }
 823                 ses->auth_key.len = tilen;
 824         }
 825
 826         return 0;
 827 }
 828
 829 static int size_of_ntlmssp_blob(struct cifs_ses *ses, int base_size)
 830 {
 831         int sz = base_size + ses->auth_key.len
 832                 - CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
 833
 834         if (ses->domainName)
 835                 sz += sizeof(__le16) * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
 836         else
 837                 sz += sizeof(__le16);
 838
 839         if (ses->user_name)
 840                 sz += sizeof(__le16) * strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);
 841         else
 842                 sz += sizeof(__le16);
 843
 844         if (ses->workstation_name[0])
 845                 sz += sizeof(__le16) * strnlen(ses->workstation_name,
 846                                                ntlmssp_workstation_name_size(ses));
 847         else
 848                 sz += sizeof(__le16);
 849
 850         return sz;
 851 }
 852
 853 static inline void cifs_security_buffer_from_str(SECURITY_BUFFER *pbuf,
 854                                                  char *str_value,
 855                                                  int str_length,
 856                                                  unsigned char *pstart,
 857                                                  unsigned char **pcur,
 858                                                  const struct nls_table *nls_cp)
 859 {
 860         unsigned char *tmp = pstart;
 861         int len;
 862
 863         if (!pbuf)
 864                 return;
 865
 866         if (!pcur)
 867                 pcur = &tmp;
 868
 869         if (!str_value) {
 870                 pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
 871                 pbuf->Length = 0;
 872                 pbuf->MaximumLength = 0;
 873                 *pcur += sizeof(__le16);
 874         } else {
 875                 len = cifs_strtoUTF16((__le16 *)*pcur,
 876                                       str_value,
 877                                       str_length,
 878                                       nls_cp);
 879                 len *= sizeof(__le16);
 880                 pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
 881                 pbuf->Length = cpu_to_le16(len);
 882                 pbuf->MaximumLength = cpu_to_le16(len);
 883                 *pcur += len;
 884         }
 885 }
 886
 887 /* BB Move to ntlmssp.c eventually */
 888
 889 int build_ntlmssp_negotiate_blob(unsigned char **pbuffer,
 890                                  u16 *buflen,
 891                                  struct cifs_ses *ses,
 892                                  struct TCP_Server_Info *server,
 893                                  const struct nls_table *nls_cp)
 894 {
 895         int rc = 0;
 896         NEGOTIATE_MESSAGE *sec_blob;
 897         __u32 flags;
 898         unsigned char *tmp;
 899         int len;
 900
 901         len = size_of_ntlmssp_blob(ses, sizeof(NEGOTIATE_MESSAGE));
 902         *pbuffer = kmalloc(len, GFP_KERNEL);
 903         if (!*pbuffer) {
 904                 rc = -ENOMEM;
 905                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
 906                 *buflen = 0;
 907                 goto setup_ntlm_neg_ret;
 908         }
 909         sec_blob = (NEGOTIATE_MESSAGE *)*pbuffer;
 910
 911         memset(*pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
 912         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 913         sec_blob->MessageType = NtLmNegotiate;
 914
 915         /* BB is NTLMV2 session security format easier to use here? */
 916         flags = NTLMSSP_NEGOTIATE_56 |  NTLMSSP_REQUEST_TARGET |
 917                 NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 918                 NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
 919                 NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
 920                 NTLMSSP_NEGOTIATE_SIGN;
 921         if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
 922                 flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 923
 924         tmp = *pbuffer + sizeof(NEGOTIATE_MESSAGE);
 925         ses->ntlmssp->client_flags = flags;
 926         sec_blob->NegotiateFlags = cpu_to_le32(flags);
 927
 928         /* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
 929         cifs_security_buffer_from_str(&sec_blob->DomainName,
 930                                       NULL,
 931                                       CIFS_MAX_DOMAINNAME_LEN,
 932                                       *pbuffer, &tmp,
 933                                       nls_cp);
 934
 935         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
 936                                       NULL,
 937                                       CIFS_MAX_WORKSTATION_LEN,
 938                                       *pbuffer, &tmp,
 939                                       nls_cp);
 940
 941         *buflen = tmp - *pbuffer;
 942 setup_ntlm_neg_ret:
 943         return rc;
 944 }
 945
 946 /*
 947  * Build ntlmssp blob with additional fields, such as version,
 948  * supported by modern servers. For safety limit to SMB3 or later
 949  * See notes in MS-NLMP Section 2.2.2.1 e.g.
 950  */
 951 int build_ntlmssp_smb3_negotiate_blob(unsigned char **pbuffer,
 952                                  u16 *buflen,
 953                                  struct cifs_ses *ses,
 954                                  struct TCP_Server_Info *server,
 955                                  const struct nls_table *nls_cp)
 956 {
 957         int rc = 0;
 958         struct negotiate_message *sec_blob;
 959         __u32 flags;
 960         unsigned char *tmp;
 961         int len;
 962
 963         len = size_of_ntlmssp_blob(ses, sizeof(struct negotiate_message));
 964         *pbuffer = kmalloc(len, GFP_KERNEL);
 965         if (!*pbuffer) {
 966                 rc = -ENOMEM;
 967                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
 968                 *buflen = 0;
 969                 goto setup_ntlm_smb3_neg_ret;
 970         }
 971         sec_blob = (struct negotiate_message *)*pbuffer;
 972
 973         memset(*pbuffer, 0, sizeof(struct negotiate_message));
 974         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 975         sec_blob->MessageType = NtLmNegotiate;
 976
 977         /* BB is NTLMV2 session security format easier to use here? */
 978         flags = NTLMSSP_NEGOTIATE_56 |  NTLMSSP_REQUEST_TARGET |
 979                 NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 980                 NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
 981                 NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
 982                 NTLMSSP_NEGOTIATE_SIGN | NTLMSSP_NEGOTIATE_VERSION;
 983         if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
 984                 flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 985
 986         sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
 987         sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
 988         sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
 989         sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
 990
 991         tmp = *pbuffer + sizeof(struct negotiate_message);
 992         ses->ntlmssp->client_flags = flags;
 993         sec_blob->NegotiateFlags = cpu_to_le32(flags);
 994
 995         /* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
 996         cifs_security_buffer_from_str(&sec_blob->DomainName,
 997                                       NULL,
 998                                       CIFS_MAX_DOMAINNAME_LEN,
 999                                       *pbuffer, &tmp,
1000                                       nls_cp);
1001
1002         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1003                                       NULL,
1004                                       CIFS_MAX_WORKSTATION_LEN,
1005                                       *pbuffer, &tmp,
1006                                       nls_cp);
1007
1008         *buflen = tmp - *pbuffer;
1009 setup_ntlm_smb3_neg_ret:
1010         return rc;
1011 }
1012
1013
1014 int build_ntlmssp_auth_blob(unsigned char **pbuffer,
1015                                         u16 *buflen,
1016                                    struct cifs_ses *ses,
1017                                    struct TCP_Server_Info *server,
1018                                    const struct nls_table *nls_cp)
1019 {
1020         int rc;
1021         AUTHENTICATE_MESSAGE *sec_blob;
1022         __u32 flags;
1023         unsigned char *tmp;
1024         int len;
1025
1026         rc = setup_ntlmv2_rsp(ses, nls_cp);
1027         if (rc) {
1028                 cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
1029                 *buflen = 0;
1030                 goto setup_ntlmv2_ret;
1031         }
1032
1033         len = size_of_ntlmssp_blob(ses, sizeof(AUTHENTICATE_MESSAGE));
1034         *pbuffer = kmalloc(len, GFP_KERNEL);
1035         if (!*pbuffer) {
1036                 rc = -ENOMEM;
1037                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1038                 *buflen = 0;
1039                 goto setup_ntlmv2_ret;
1040         }
1041         sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
1042
1043         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1044         sec_blob->MessageType = NtLmAuthenticate;
1045
1046         flags = ses->ntlmssp->server_flags | NTLMSSP_REQUEST_TARGET |
1047                 NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED;
1048
1049         tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
1050         sec_blob->NegotiateFlags = cpu_to_le32(flags);
1051
1052         sec_blob->LmChallengeResponse.BufferOffset =
1053                                 cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
1054         sec_blob->LmChallengeResponse.Length = 0;
1055         sec_blob->LmChallengeResponse.MaximumLength = 0;
1056
1057         sec_blob->NtChallengeResponse.BufferOffset =
1058                                 cpu_to_le32(tmp - *pbuffer);
1059         if (ses->user_name != NULL) {
1060                 memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1061                                 ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1062                 tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1063
1064                 sec_blob->NtChallengeResponse.Length =
1065                                 cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1066                 sec_blob->NtChallengeResponse.MaximumLength =
1067                                 cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1068         } else {
1069                 /*
1070                  * don't send an NT Response for anonymous access
1071                  */
1072                 sec_blob->NtChallengeResponse.Length = 0;
1073                 sec_blob->NtChallengeResponse.MaximumLength = 0;
1074         }
1075
1076         cifs_security_buffer_from_str(&sec_blob->DomainName,
1077                                       ses->domainName,
1078                                       CIFS_MAX_DOMAINNAME_LEN,
1079                                       *pbuffer, &tmp,
1080                                       nls_cp);
1081
1082         cifs_security_buffer_from_str(&sec_blob->UserName,
1083                                       ses->user_name,
1084                                       CIFS_MAX_USERNAME_LEN,
1085                                       *pbuffer, &tmp,
1086                                       nls_cp);
1087
1088         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1089                                       ses->workstation_name,
1090                                       ntlmssp_workstation_name_size(ses),
1091                                       *pbuffer, &tmp,
1092                                       nls_cp);
1093
1094         if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
1095             (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) &&
1096             !calc_seckey(ses)) {
1097                 memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
1098                 sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1099                 sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
1100                 sec_blob->SessionKey.MaximumLength =
1101                                 cpu_to_le16(CIFS_CPHTXT_SIZE);
1102                 tmp += CIFS_CPHTXT_SIZE;
1103         } else {
1104                 sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1105                 sec_blob->SessionKey.Length = 0;
1106                 sec_blob->SessionKey.MaximumLength = 0;
1107         }
1108
1109         *buflen = tmp - *pbuffer;
1110 setup_ntlmv2_ret:
1111         return rc;
1112 }
1113
1114 enum securityEnum
1115 cifs_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
1116 {
1117         switch (server->negflavor) {
1118         case CIFS_NEGFLAVOR_EXTENDED:
1119                 switch (requested) {
1120                 case Kerberos:
1121                 case RawNTLMSSP:
1122                         return requested;
1123                 case Unspecified:
1124                         if (server->sec_ntlmssp &&
1125                             (global_secflags & CIFSSEC_MAY_NTLMSSP))
1126                                 return RawNTLMSSP;
1127                         if ((server->sec_kerberos || server->sec_mskerberos) &&
1128                             (global_secflags & CIFSSEC_MAY_KRB5))
1129                                 return Kerberos;
1130                         fallthrough;
1131                 default:
1132                         return Unspecified;
1133                 }
1134         case CIFS_NEGFLAVOR_UNENCAP:
1135                 switch (requested) {
1136                 case NTLMv2:
1137                         return requested;
1138                 case Unspecified:
1139                         if (global_secflags & CIFSSEC_MAY_NTLMV2)
1140                                 return NTLMv2;
1141                         break;
1142                 default:
1143                         break;
1144                 }
1145                 fallthrough;
1146         default:
1147                 return Unspecified;
1148         }
1149 }
1150
1151 struct sess_data {
1152         unsigned int xid;
1153         struct cifs_ses *ses;
1154         struct TCP_Server_Info *server;
1155         struct nls_table *nls_cp;
1156         void (*func)(struct sess_data *);
1157         int result;
1158
1159         /* we will send the SMB in three pieces:
1160          * a fixed length beginning part, an optional
1161          * SPNEGO blob (which can be zero length), and a
1162          * last part which will include the strings
1163          * and rest of bcc area. This allows us to avoid
1164          * a large buffer 17K allocation
1165          */
1166         int buf0_type;
1167         struct kvec iov[3];
1168 };
1169
1170 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
1171 static int
1172 sess_alloc_buffer(struct sess_data *sess_data, int wct)
1173 {
1174         int rc;
1175         struct cifs_ses *ses = sess_data->ses;
1176         struct smb_hdr *smb_buf;
1177
1178         rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
1179                                   (void **)&smb_buf);
1180
1181         if (rc)
1182                 return rc;
1183
1184         sess_data->iov[0].iov_base = (char *)smb_buf;
1185         sess_data->iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
1186         /*
1187          * This variable will be used to clear the buffer
1188          * allocated above in case of any error in the calling function.
1189          */
1190         sess_data->buf0_type = CIFS_SMALL_BUFFER;
1191
1192         /* 2000 big enough to fit max user, domain, NOS name etc. */
1193         sess_data->iov[2].iov_base = kmalloc(2000, GFP_KERNEL);
1194         if (!sess_data->iov[2].iov_base) {
1195                 rc = -ENOMEM;
1196                 goto out_free_smb_buf;
1197         }
1198
1199         return 0;
1200
1201 out_free_smb_buf:
1202         cifs_small_buf_release(smb_buf);
1203         sess_data->iov[0].iov_base = NULL;
1204         sess_data->iov[0].iov_len = 0;
1205         sess_data->buf0_type = CIFS_NO_BUFFER;
1206         return rc;
1207 }
1208
1209 static void
1210 sess_free_buffer(struct sess_data *sess_data)
1211 {
1212         struct kvec *iov = sess_data->iov;
1213
1214         /*
1215          * Zero the session data before freeing, as it might contain sensitive info (keys, etc).
1216          * Note that iov[1] is already freed by caller.
1217          */
1218         if (sess_data->buf0_type != CIFS_NO_BUFFER && iov[0].iov_base)
1219                 memzero_explicit(iov[0].iov_base, iov[0].iov_len);
1220
1221         free_rsp_buf(sess_data->buf0_type, iov[0].iov_base);
1222         sess_data->buf0_type = CIFS_NO_BUFFER;
1223         kfree_sensitive(iov[2].iov_base);
1224 }
1225
1226 static int
1227 sess_establish_session(struct sess_data *sess_data)
1228 {
1229         struct cifs_ses *ses = sess_data->ses;
1230         struct TCP_Server_Info *server = sess_data->server;
1231
1232         cifs_server_lock(server);
1233         if (!server->session_estab) {
1234                 if (server->sign) {
1235                         server->session_key.response =
1236                                 kmemdup(ses->auth_key.response,
1237                                 ses->auth_key.len, GFP_KERNEL);
1238                         if (!server->session_key.response) {
1239                                 cifs_server_unlock(server);
1240                                 return -ENOMEM;
1241                         }
1242                         server->session_key.len =
1243                                                 ses->auth_key.len;
1244                 }
1245                 server->sequence_number = 0x2;
1246                 server->session_estab = true;
1247         }
1248         cifs_server_unlock(server);
1249
1250         cifs_dbg(FYI, "CIFS session established successfully\n");
1251         return 0;
1252 }
1253
1254 static int
1255 sess_sendreceive(struct sess_data *sess_data)
1256 {
1257         int rc;
1258         struct smb_hdr *smb_buf = (struct smb_hdr *) sess_data->iov[0].iov_base;
1259         __u16 count;
1260         struct kvec rsp_iov = { NULL, 0 };
1261
1262         count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
1263         be32_add_cpu(&smb_buf->smb_buf_length, count);
1264         put_bcc(count, smb_buf);
1265
1266         rc = SendReceive2(sess_data->xid, sess_data->ses,
1267                           sess_data->iov, 3 /* num_iovecs */,
1268                           &sess_data->buf0_type,
1269                           CIFS_LOG_ERROR, &rsp_iov);
1270         cifs_small_buf_release(sess_data->iov[0].iov_base);
1271         memcpy(&sess_data->iov[0], &rsp_iov, sizeof(struct kvec));
1272
1273         return rc;
1274 }
1275
1276 static void
1277 sess_auth_ntlmv2(struct sess_data *sess_data)
1278 {
1279         int rc = 0;
1280         struct smb_hdr *smb_buf;
1281         SESSION_SETUP_ANDX *pSMB;
1282         char *bcc_ptr;
1283         struct cifs_ses *ses = sess_data->ses;
1284         struct TCP_Server_Info *server = sess_data->server;
1285         __u32 capabilities;
1286         __u16 bytes_remaining;
1287
1288         /* old style NTLM sessionsetup */
1289         /* wct = 13 */
1290         rc = sess_alloc_buffer(sess_data, 13);
1291         if (rc)
1292                 goto out;
1293
1294         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1295         bcc_ptr = sess_data->iov[2].iov_base;
1296         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1297
1298         pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
1299
1300         /* LM2 password would be here if we supported it */
1301         pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
1302
1303         if (ses->user_name != NULL) {
1304                 /* calculate nlmv2 response and session key */
1305                 rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
1306                 if (rc) {
1307                         cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n", rc);
1308                         goto out;
1309                 }
1310
1311                 memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1312                                 ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1313                 bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1314
1315                 /* set case sensitive password length after tilen may get
1316                  * assigned, tilen is 0 otherwise.
1317                  */
1318                 pSMB->req_no_secext.CaseSensitivePasswordLength =
1319                         cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1320         } else {
1321                 pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
1322         }
1323
1324         if (ses->capabilities & CAP_UNICODE) {
1325                 if (!IS_ALIGNED(sess_data->iov[0].iov_len, 2)) {
1326                         *bcc_ptr = 0;
1327                         bcc_ptr++;
1328                 }
1329                 unicode_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1330         } else {
1331                 ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1332         }
1333
1334
1335         sess_data->iov[2].iov_len = (long) bcc_ptr -
1336                         (long) sess_data->iov[2].iov_base;
1337
1338         rc = sess_sendreceive(sess_data);
1339         if (rc)
1340                 goto out;
1341
1342         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1343         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1344
1345         if (smb_buf->WordCount != 3) {
1346                 rc = -EIO;
1347                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1348                 goto out;
1349         }
1350
1351         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1352                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1353
1354         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1355         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1356
1357         bytes_remaining = get_bcc(smb_buf);
1358         bcc_ptr = pByteArea(smb_buf);
1359
1360         /* BB check if Unicode and decode strings */
1361         if (bytes_remaining == 0) {
1362                 /* no string area to decode, do nothing */
1363         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1364                 /* unicode string area must be word-aligned */
1365                 if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1366                         ++bcc_ptr;
1367                         --bytes_remaining;
1368                 }
1369                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1370                                       sess_data->nls_cp);
1371         } else {
1372                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1373                                     sess_data->nls_cp);
1374         }
1375
1376         rc = sess_establish_session(sess_data);
1377 out:
1378         sess_data->result = rc;
1379         sess_data->func = NULL;
1380         sess_free_buffer(sess_data);
1381         kfree_sensitive(ses->auth_key.response);
1382         ses->auth_key.response = NULL;
1383 }
1384
1385 #ifdef CONFIG_CIFS_UPCALL
1386 static void
1387 sess_auth_kerberos(struct sess_data *sess_data)
1388 {
1389         int rc = 0;
1390         struct smb_hdr *smb_buf;
1391         SESSION_SETUP_ANDX *pSMB;
1392         char *bcc_ptr;
1393         struct cifs_ses *ses = sess_data->ses;
1394         struct TCP_Server_Info *server = sess_data->server;
1395         __u32 capabilities;
1396         __u16 bytes_remaining;
1397         struct key *spnego_key = NULL;
1398         struct cifs_spnego_msg *msg;
1399         u16 blob_len;
1400
1401         /* extended security */
1402         /* wct = 12 */
1403         rc = sess_alloc_buffer(sess_data, 12);
1404         if (rc)
1405                 goto out;
1406
1407         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1408         bcc_ptr = sess_data->iov[2].iov_base;
1409         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1410
1411         spnego_key = cifs_get_spnego_key(ses, server);
1412         if (IS_ERR(spnego_key)) {
1413                 rc = PTR_ERR(spnego_key);
1414                 spnego_key = NULL;
1415                 goto out;
1416         }
1417
1418         msg = spnego_key->payload.data[0];
1419         /*
1420          * check version field to make sure that cifs.upcall is
1421          * sending us a response in an expected form
1422          */
1423         if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
1424                 cifs_dbg(VFS, "incorrect version of cifs.upcall (expected %d but got %d)\n",
1425                          CIFS_SPNEGO_UPCALL_VERSION, msg->version);
1426                 rc = -EKEYREJECTED;
1427                 goto out_put_spnego_key;
1428         }
1429
1430         ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
1431                                          GFP_KERNEL);
1432         if (!ses->auth_key.response) {
1433                 cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory\n",
1434                          msg->sesskey_len);
1435                 rc = -ENOMEM;
1436                 goto out_put_spnego_key;
1437         }
1438         ses->auth_key.len = msg->sesskey_len;
1439
1440         pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1441         capabilities |= CAP_EXTENDED_SECURITY;
1442         pSMB->req.Capabilities = cpu_to_le32(capabilities);
1443         sess_data->iov[1].iov_base = msg->data + msg->sesskey_len;
1444         sess_data->iov[1].iov_len = msg->secblob_len;
1445         pSMB->req.SecurityBlobLength = cpu_to_le16(sess_data->iov[1].iov_len);
1446
1447         if (ses->capabilities & CAP_UNICODE) {
1448                 /* unicode strings must be word aligned */
1449                 if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1450                         *bcc_ptr = 0;
1451                         bcc_ptr++;
1452                 }
1453                 unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1454                 unicode_domain_string(&bcc_ptr, ses, sess_data->nls_cp);
1455         } else {
1456                 /* BB: is this right? */
1457                 ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1458         }
1459
1460         sess_data->iov[2].iov_len = (long) bcc_ptr -
1461                         (long) sess_data->iov[2].iov_base;
1462
1463         rc = sess_sendreceive(sess_data);
1464         if (rc)
1465                 goto out_put_spnego_key;
1466
1467         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1468         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1469
1470         if (smb_buf->WordCount != 4) {
1471                 rc = -EIO;
1472                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1473                 goto out_put_spnego_key;
1474         }
1475
1476         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1477                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1478
1479         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1480         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1481
1482         bytes_remaining = get_bcc(smb_buf);
1483         bcc_ptr = pByteArea(smb_buf);
1484
1485         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1486         if (blob_len > bytes_remaining) {
1487                 cifs_dbg(VFS, "bad security blob length %d\n",
1488                                 blob_len);
1489                 rc = -EINVAL;
1490                 goto out_put_spnego_key;
1491         }
1492         bcc_ptr += blob_len;
1493         bytes_remaining -= blob_len;
1494
1495         /* BB check if Unicode and decode strings */
1496         if (bytes_remaining == 0) {
1497                 /* no string area to decode, do nothing */
1498         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1499                 /* unicode string area must be word-aligned */
1500                 if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1501                         ++bcc_ptr;
1502                         --bytes_remaining;
1503                 }
1504                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1505                                       sess_data->nls_cp);
1506         } else {
1507                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1508                                     sess_data->nls_cp);
1509         }
1510
1511         rc = sess_establish_session(sess_data);
1512 out_put_spnego_key:
1513         key_invalidate(spnego_key);
1514         key_put(spnego_key);
1515 out:
1516         sess_data->result = rc;
1517         sess_data->func = NULL;
1518         sess_free_buffer(sess_data);
1519         kfree_sensitive(ses->auth_key.response);
1520         ses->auth_key.response = NULL;
1521 }
1522
1523 #endif /* ! CONFIG_CIFS_UPCALL */
1524
1525 /*
1526  * The required kvec buffers have to be allocated before calling this
1527  * function.
1528  */
1529 static int
1530 _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)
1531 {
1532         SESSION_SETUP_ANDX *pSMB;
1533         struct cifs_ses *ses = sess_data->ses;
1534         struct TCP_Server_Info *server = sess_data->server;
1535         __u32 capabilities;
1536         char *bcc_ptr;
1537
1538         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1539
1540         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1541         if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
1542                 cifs_dbg(VFS, "NTLMSSP requires Unicode support\n");
1543                 return -ENOSYS;
1544         }
1545
1546         pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1547         capabilities |= CAP_EXTENDED_SECURITY;
1548         pSMB->req.Capabilities |= cpu_to_le32(capabilities);
1549
1550         bcc_ptr = sess_data->iov[2].iov_base;
1551         /* unicode strings must be word aligned */
1552         if (!IS_ALIGNED(sess_data->iov[0].iov_len + sess_data->iov[1].iov_len, 2)) {
1553                 *bcc_ptr = 0;
1554                 bcc_ptr++;
1555         }
1556         unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1557
1558         sess_data->iov[2].iov_len = (long) bcc_ptr -
1559                                         (long) sess_data->iov[2].iov_base;
1560
1561         return 0;
1562 }
1563
1564 static void
1565 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data);
1566
1567 static void
1568 sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data)
1569 {
1570         int rc;
1571         struct smb_hdr *smb_buf;
1572         SESSION_SETUP_ANDX *pSMB;
1573         struct cifs_ses *ses = sess_data->ses;
1574         struct TCP_Server_Info *server = sess_data->server;
1575         __u16 bytes_remaining;
1576         char *bcc_ptr;
1577         unsigned char *ntlmsspblob = NULL;
1578         u16 blob_len;
1579
1580         cifs_dbg(FYI, "rawntlmssp session setup negotiate phase\n");
1581
1582         /*
1583          * if memory allocation is successful, caller of this function
1584          * frees it.
1585          */
1586         ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
1587         if (!ses->ntlmssp) {
1588                 rc = -ENOMEM;
1589                 goto out;
1590         }
1591         ses->ntlmssp->sesskey_per_smbsess = false;
1592
1593         /* wct = 12 */
1594         rc = sess_alloc_buffer(sess_data, 12);
1595         if (rc)
1596                 goto out;
1597
1598         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1599
1600         /* Build security blob before we assemble the request */
1601         rc = build_ntlmssp_negotiate_blob(&ntlmsspblob,
1602                                      &blob_len, ses, server,
1603                                      sess_data->nls_cp);
1604         if (rc)
1605                 goto out_free_ntlmsspblob;
1606
1607         sess_data->iov[1].iov_len = blob_len;
1608         sess_data->iov[1].iov_base = ntlmsspblob;
1609         pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1610
1611         rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1612         if (rc)
1613                 goto out_free_ntlmsspblob;
1614
1615         rc = sess_sendreceive(sess_data);
1616
1617         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1618         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1619
1620         /* If true, rc here is expected and not an error */
1621         if (sess_data->buf0_type != CIFS_NO_BUFFER &&
1622             smb_buf->Status.CifsError ==
1623                         cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
1624                 rc = 0;
1625
1626         if (rc)
1627                 goto out_free_ntlmsspblob;
1628
1629         cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");
1630
1631         if (smb_buf->WordCount != 4) {
1632                 rc = -EIO;
1633                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1634                 goto out_free_ntlmsspblob;
1635         }
1636
1637         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1638         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1639
1640         bytes_remaining = get_bcc(smb_buf);
1641         bcc_ptr = pByteArea(smb_buf);
1642
1643         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1644         if (blob_len > bytes_remaining) {
1645                 cifs_dbg(VFS, "bad security blob length %d\n",
1646                                 blob_len);
1647                 rc = -EINVAL;
1648                 goto out_free_ntlmsspblob;
1649         }
1650
1651         rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
1652
1653 out_free_ntlmsspblob:
1654         kfree_sensitive(ntlmsspblob);
1655 out:
1656         sess_free_buffer(sess_data);
1657
1658         if (!rc) {
1659                 sess_data->func = sess_auth_rawntlmssp_authenticate;
1660                 return;
1661         }
1662
1663         /* Else error. Cleanup */
1664         kfree_sensitive(ses->auth_key.response);
1665         ses->auth_key.response = NULL;
1666         kfree_sensitive(ses->ntlmssp);
1667         ses->ntlmssp = NULL;
1668
1669         sess_data->func = NULL;
1670         sess_data->result = rc;
1671 }
1672
1673 static void
1674 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
1675 {
1676         int rc;
1677         struct smb_hdr *smb_buf;
1678         SESSION_SETUP_ANDX *pSMB;
1679         struct cifs_ses *ses = sess_data->ses;
1680         struct TCP_Server_Info *server = sess_data->server;
1681         __u16 bytes_remaining;
1682         char *bcc_ptr;
1683         unsigned char *ntlmsspblob = NULL;
1684         u16 blob_len;
1685
1686         cifs_dbg(FYI, "rawntlmssp session setup authenticate phase\n");
1687
1688         /* wct = 12 */
1689         rc = sess_alloc_buffer(sess_data, 12);
1690         if (rc)
1691                 goto out;
1692
1693         /* Build security blob before we assemble the request */
1694         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1695         smb_buf = (struct smb_hdr *)pSMB;
1696         rc = build_ntlmssp_auth_blob(&ntlmsspblob,
1697                                         &blob_len, ses, server,
1698                                         sess_data->nls_cp);
1699         if (rc)
1700                 goto out_free_ntlmsspblob;
1701         sess_data->iov[1].iov_len = blob_len;
1702         sess_data->iov[1].iov_base = ntlmsspblob;
1703         pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1704         /*
1705          * Make sure that we tell the server that we are using
1706          * the uid that it just gave us back on the response
1707          * (challenge)
1708          */
1709         smb_buf->Uid = ses->Suid;
1710
1711         rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1712         if (rc)
1713                 goto out_free_ntlmsspblob;
1714
1715         rc = sess_sendreceive(sess_data);
1716         if (rc)
1717                 goto out_free_ntlmsspblob;
1718
1719         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1720         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1721         if (smb_buf->WordCount != 4) {
1722                 rc = -EIO;
1723                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1724                 goto out_free_ntlmsspblob;
1725         }
1726
1727         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1728                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1729
1730         if (ses->Suid != smb_buf->Uid) {
1731                 ses->Suid = smb_buf->Uid;
1732                 cifs_dbg(FYI, "UID changed! new UID = %llu\n", ses->Suid);
1733         }
1734
1735         bytes_remaining = get_bcc(smb_buf);
1736         bcc_ptr = pByteArea(smb_buf);
1737         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1738         if (blob_len > bytes_remaining) {
1739                 cifs_dbg(VFS, "bad security blob length %d\n",
1740                                 blob_len);
1741                 rc = -EINVAL;
1742                 goto out_free_ntlmsspblob;
1743         }
1744         bcc_ptr += blob_len;
1745         bytes_remaining -= blob_len;
1746
1747
1748         /* BB check if Unicode and decode strings */
1749         if (bytes_remaining == 0) {
1750                 /* no string area to decode, do nothing */
1751         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1752                 /* unicode string area must be word-aligned */
1753                 if (!IS_ALIGNED((unsigned long)bcc_ptr - (unsigned long)smb_buf, 2)) {
1754                         ++bcc_ptr;
1755                         --bytes_remaining;
1756                 }
1757                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1758                                       sess_data->nls_cp);
1759         } else {
1760                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1761                                     sess_data->nls_cp);
1762         }
1763
1764 out_free_ntlmsspblob:
1765         kfree_sensitive(ntlmsspblob);
1766 out:
1767         sess_free_buffer(sess_data);
1768
1769         if (!rc)
1770                 rc = sess_establish_session(sess_data);
1771
1772         /* Cleanup */
1773         kfree_sensitive(ses->auth_key.response);
1774         ses->auth_key.response = NULL;
1775         kfree_sensitive(ses->ntlmssp);
1776         ses->ntlmssp = NULL;
1777
1778         sess_data->func = NULL;
1779         sess_data->result = rc;
1780 }
1781
1782 static int select_sec(struct sess_data *sess_data)
1783 {
1784         int type;
1785         struct cifs_ses *ses = sess_data->ses;
1786         struct TCP_Server_Info *server = sess_data->server;
1787
1788         type = cifs_select_sectype(server, ses->sectype);
1789         cifs_dbg(FYI, "sess setup type %d\n", type);
1790         if (type == Unspecified) {
1791                 cifs_dbg(VFS, "Unable to select appropriate authentication method!\n");
1792                 return -EINVAL;
1793         }
1794
1795         switch (type) {
1796         case NTLMv2:
1797                 sess_data->func = sess_auth_ntlmv2;
1798                 break;
1799         case Kerberos:
1800 #ifdef CONFIG_CIFS_UPCALL
1801                 sess_data->func = sess_auth_kerberos;
1802                 break;
1803 #else
1804                 cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
1805                 return -ENOSYS;
1806 #endif /* CONFIG_CIFS_UPCALL */
1807         case RawNTLMSSP:
1808                 sess_data->func = sess_auth_rawntlmssp_negotiate;
1809                 break;
1810         default:
1811                 cifs_dbg(VFS, "secType %d not supported!\n", type);
1812                 return -ENOSYS;
1813         }
1814
1815         return 0;
1816 }
1817
1818 int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
1819                    struct TCP_Server_Info *server,
1820                    const struct nls_table *nls_cp)
1821 {
1822         int rc = 0;
1823         struct sess_data *sess_data;
1824
1825         if (ses == NULL) {
1826                 WARN(1, "%s: ses == NULL!", __func__);
1827                 return -EINVAL;
1828         }
1829
1830         sess_data = kzalloc(sizeof(struct sess_data), GFP_KERNEL);
1831         if (!sess_data)
1832                 return -ENOMEM;
1833
1834         sess_data->xid = xid;
1835         sess_data->ses = ses;
1836         sess_data->server = server;
1837         sess_data->buf0_type = CIFS_NO_BUFFER;
1838         sess_data->nls_cp = (struct nls_table *) nls_cp;
1839
1840         rc = select_sec(sess_data);
1841         if (rc)
1842                 goto out;
1843
1844         while (sess_data->func)
1845                 sess_data->func(sess_data);
1846
1847         /* Store result before we free sess_data */
1848         rc = sess_data->result;
1849
1850 out:
1851         kfree_sensitive(sess_data);
1852         return rc;
1853 }
1854 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */