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         }
 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                 kref_put(&old_iface->refcount, release_iface);
 306                 cifs_dbg(FYI, "replacing iface: %pIS with %pIS\n",
 307                          &old_iface->sockaddr,
 308                          &iface->sockaddr);
 309         } else if (old_iface) {
 310                 kref_put(&old_iface->refcount, release_iface);
 311                 cifs_dbg(FYI, "releasing ref to iface: %pIS\n",
 312                          &old_iface->sockaddr);
 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         return rc;
 500 }
 501
 502 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
 503 static __u32 cifs_ssetup_hdr(struct cifs_ses *ses,
 504                              struct TCP_Server_Info *server,
 505                              SESSION_SETUP_ANDX *pSMB)
 506 {
 507         __u32 capabilities = 0;
 508
 509         /* init fields common to all four types of SessSetup */
 510         /* Note that offsets for first seven fields in req struct are same  */
 511         /*      in CIFS Specs so does not matter which of 3 forms of struct */
 512         /*      that we use in next few lines                               */
 513         /* Note that header is initialized to zero in header_assemble */
 514         pSMB->req.AndXCommand = 0xFF;
 515         pSMB->req.MaxBufferSize = cpu_to_le16(min_t(u32,
 516                                         CIFSMaxBufSize + MAX_CIFS_HDR_SIZE - 4,
 517                                         USHRT_MAX));
 518         pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq);
 519         pSMB->req.VcNumber = cpu_to_le16(1);
 520
 521         /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */
 522
 523         /* BB verify whether signing required on neg or just on auth frame
 524            (and NTLM case) */
 525
 526         capabilities = CAP_LARGE_FILES | CAP_NT_SMBS | CAP_LEVEL_II_OPLOCKS |
 527                         CAP_LARGE_WRITE_X | CAP_LARGE_READ_X;
 528
 529         if (server->sign)
 530                 pSMB->req.hdr.Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
 531
 532         if (ses->capabilities & CAP_UNICODE) {
 533                 pSMB->req.hdr.Flags2 |= SMBFLG2_UNICODE;
 534                 capabilities |= CAP_UNICODE;
 535         }
 536         if (ses->capabilities & CAP_STATUS32) {
 537                 pSMB->req.hdr.Flags2 |= SMBFLG2_ERR_STATUS;
 538                 capabilities |= CAP_STATUS32;
 539         }
 540         if (ses->capabilities & CAP_DFS) {
 541                 pSMB->req.hdr.Flags2 |= SMBFLG2_DFS;
 542                 capabilities |= CAP_DFS;
 543         }
 544         if (ses->capabilities & CAP_UNIX)
 545                 capabilities |= CAP_UNIX;
 546
 547         return capabilities;
 548 }
 549
 550 static void
 551 unicode_oslm_strings(char **pbcc_area, const struct nls_table *nls_cp)
 552 {
 553         char *bcc_ptr = *pbcc_area;
 554         int bytes_ret = 0;
 555
 556         /* Copy OS version */
 557         bytes_ret = cifs_strtoUTF16((__le16 *)bcc_ptr, "Linux version ", 32,
 558                                     nls_cp);
 559         bcc_ptr += 2 * bytes_ret;
 560         bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, init_utsname()->release,
 561                                     32, nls_cp);
 562         bcc_ptr += 2 * bytes_ret;
 563         bcc_ptr += 2; /* trailing null */
 564
 565         bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, CIFS_NETWORK_OPSYS,
 566                                     32, nls_cp);
 567         bcc_ptr += 2 * bytes_ret;
 568         bcc_ptr += 2; /* trailing null */
 569
 570         *pbcc_area = bcc_ptr;
 571 }
 572
 573 static void unicode_domain_string(char **pbcc_area, struct cifs_ses *ses,
 574                                    const struct nls_table *nls_cp)
 575 {
 576         char *bcc_ptr = *pbcc_area;
 577         int bytes_ret = 0;
 578
 579         /* copy domain */
 580         if (ses->domainName == NULL) {
 581                 /* Sending null domain better than using a bogus domain name (as
 582                 we did briefly in 2.6.18) since server will use its default */
 583                 *bcc_ptr = 0;
 584                 *(bcc_ptr+1) = 0;
 585                 bytes_ret = 0;
 586         } else
 587                 bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->domainName,
 588                                             CIFS_MAX_DOMAINNAME_LEN, nls_cp);
 589         bcc_ptr += 2 * bytes_ret;
 590         bcc_ptr += 2;  /* account for null terminator */
 591
 592         *pbcc_area = bcc_ptr;
 593 }
 594
 595 static void unicode_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
 596                                    const struct nls_table *nls_cp)
 597 {
 598         char *bcc_ptr = *pbcc_area;
 599         int bytes_ret = 0;
 600
 601         /* BB FIXME add check that strings total less
 602         than 335 or will need to send them as arrays */
 603
 604         /* unicode strings, must be word aligned before the call */
 605 /*      if ((long) bcc_ptr % 2) {
 606                 *bcc_ptr = 0;
 607                 bcc_ptr++;
 608         } */
 609         /* copy user */
 610         if (ses->user_name == NULL) {
 611                 /* null user mount */
 612                 *bcc_ptr = 0;
 613                 *(bcc_ptr+1) = 0;
 614         } else {
 615                 bytes_ret = cifs_strtoUTF16((__le16 *) bcc_ptr, ses->user_name,
 616                                             CIFS_MAX_USERNAME_LEN, nls_cp);
 617         }
 618         bcc_ptr += 2 * bytes_ret;
 619         bcc_ptr += 2; /* account for null termination */
 620
 621         unicode_domain_string(&bcc_ptr, ses, nls_cp);
 622         unicode_oslm_strings(&bcc_ptr, nls_cp);
 623
 624         *pbcc_area = bcc_ptr;
 625 }
 626
 627 static void ascii_ssetup_strings(char **pbcc_area, struct cifs_ses *ses,
 628                                  const struct nls_table *nls_cp)
 629 {
 630         char *bcc_ptr = *pbcc_area;
 631         int len;
 632
 633         /* copy user */
 634         /* BB what about null user mounts - check that we do this BB */
 635         /* copy user */
 636         if (ses->user_name != NULL) {
 637                 len = strscpy(bcc_ptr, ses->user_name, CIFS_MAX_USERNAME_LEN);
 638                 if (WARN_ON_ONCE(len < 0))
 639                         len = CIFS_MAX_USERNAME_LEN - 1;
 640                 bcc_ptr += len;
 641         }
 642         /* else null user mount */
 643         *bcc_ptr = 0;
 644         bcc_ptr++; /* account for null termination */
 645
 646         /* copy domain */
 647         if (ses->domainName != NULL) {
 648                 len = strscpy(bcc_ptr, ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
 649                 if (WARN_ON_ONCE(len < 0))
 650                         len = CIFS_MAX_DOMAINNAME_LEN - 1;
 651                 bcc_ptr += len;
 652         } /* else we will send a null domain name
 653              so the server will default to its own domain */
 654         *bcc_ptr = 0;
 655         bcc_ptr++;
 656
 657         /* BB check for overflow here */
 658
 659         strcpy(bcc_ptr, "Linux version ");
 660         bcc_ptr += strlen("Linux version ");
 661         strcpy(bcc_ptr, init_utsname()->release);
 662         bcc_ptr += strlen(init_utsname()->release) + 1;
 663
 664         strcpy(bcc_ptr, CIFS_NETWORK_OPSYS);
 665         bcc_ptr += strlen(CIFS_NETWORK_OPSYS) + 1;
 666
 667         *pbcc_area = bcc_ptr;
 668 }
 669
 670 static void
 671 decode_unicode_ssetup(char **pbcc_area, int bleft, struct cifs_ses *ses,
 672                       const struct nls_table *nls_cp)
 673 {
 674         int len;
 675         char *data = *pbcc_area;
 676
 677         cifs_dbg(FYI, "bleft %d\n", bleft);
 678
 679         kfree(ses->serverOS);
 680         ses->serverOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 681         cifs_dbg(FYI, "serverOS=%s\n", ses->serverOS);
 682         len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
 683         data += len;
 684         bleft -= len;
 685         if (bleft <= 0)
 686                 return;
 687
 688         kfree(ses->serverNOS);
 689         ses->serverNOS = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 690         cifs_dbg(FYI, "serverNOS=%s\n", ses->serverNOS);
 691         len = (UniStrnlen((wchar_t *) data, bleft / 2) * 2) + 2;
 692         data += len;
 693         bleft -= len;
 694         if (bleft <= 0)
 695                 return;
 696
 697         kfree(ses->serverDomain);
 698         ses->serverDomain = cifs_strndup_from_utf16(data, bleft, true, nls_cp);
 699         cifs_dbg(FYI, "serverDomain=%s\n", ses->serverDomain);
 700
 701         return;
 702 }
 703
 704 static void decode_ascii_ssetup(char **pbcc_area, __u16 bleft,
 705                                 struct cifs_ses *ses,
 706                                 const struct nls_table *nls_cp)
 707 {
 708         int len;
 709         char *bcc_ptr = *pbcc_area;
 710
 711         cifs_dbg(FYI, "decode sessetup ascii. bleft %d\n", bleft);
 712
 713         len = strnlen(bcc_ptr, bleft);
 714         if (len >= bleft)
 715                 return;
 716
 717         kfree(ses->serverOS);
 718
 719         ses->serverOS = kmalloc(len + 1, GFP_KERNEL);
 720         if (ses->serverOS) {
 721                 memcpy(ses->serverOS, bcc_ptr, len);
 722                 ses->serverOS[len] = 0;
 723                 if (strncmp(ses->serverOS, "OS/2", 4) == 0)
 724                         cifs_dbg(FYI, "OS/2 server\n");
 725         }
 726
 727         bcc_ptr += len + 1;
 728         bleft -= len + 1;
 729
 730         len = strnlen(bcc_ptr, bleft);
 731         if (len >= bleft)
 732                 return;
 733
 734         kfree(ses->serverNOS);
 735
 736         ses->serverNOS = kmalloc(len + 1, GFP_KERNEL);
 737         if (ses->serverNOS) {
 738                 memcpy(ses->serverNOS, bcc_ptr, len);
 739                 ses->serverNOS[len] = 0;
 740         }
 741
 742         bcc_ptr += len + 1;
 743         bleft -= len + 1;
 744
 745         len = strnlen(bcc_ptr, bleft);
 746         if (len > bleft)
 747                 return;
 748
 749         /* No domain field in LANMAN case. Domain is
 750            returned by old servers in the SMB negprot response */
 751         /* BB For newer servers which do not support Unicode,
 752            but thus do return domain here we could add parsing
 753            for it later, but it is not very important */
 754         cifs_dbg(FYI, "ascii: bytes left %d\n", bleft);
 755 }
 756 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
 757
 758 int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
 759                                     struct cifs_ses *ses)
 760 {
 761         unsigned int tioffset; /* challenge message target info area */
 762         unsigned int tilen; /* challenge message target info area length  */
 763         CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
 764         __u32 server_flags;
 765
 766         if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
 767                 cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len);
 768                 return -EINVAL;
 769         }
 770
 771         if (memcmp(pblob->Signature, "NTLMSSP", 8)) {
 772                 cifs_dbg(VFS, "blob signature incorrect %s\n",
 773                          pblob->Signature);
 774                 return -EINVAL;
 775         }
 776         if (pblob->MessageType != NtLmChallenge) {
 777                 cifs_dbg(VFS, "Incorrect message type %d\n",
 778                          pblob->MessageType);
 779                 return -EINVAL;
 780         }
 781
 782         server_flags = le32_to_cpu(pblob->NegotiateFlags);
 783         cifs_dbg(FYI, "%s: negotiate=0x%08x challenge=0x%08x\n", __func__,
 784                  ses->ntlmssp->client_flags, server_flags);
 785
 786         if ((ses->ntlmssp->client_flags & (NTLMSSP_NEGOTIATE_SEAL | NTLMSSP_NEGOTIATE_SIGN)) &&
 787             (!(server_flags & NTLMSSP_NEGOTIATE_56) && !(server_flags & NTLMSSP_NEGOTIATE_128))) {
 788                 cifs_dbg(VFS, "%s: requested signing/encryption but server did not return either 56-bit or 128-bit session key size\n",
 789                          __func__);
 790                 return -EINVAL;
 791         }
 792         if (!(server_flags & NTLMSSP_NEGOTIATE_NTLM) && !(server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC)) {
 793                 cifs_dbg(VFS, "%s: server does not seem to support either NTLMv1 or NTLMv2\n", __func__);
 794                 return -EINVAL;
 795         }
 796         if (ses->server->sign && !(server_flags & NTLMSSP_NEGOTIATE_SIGN)) {
 797                 cifs_dbg(VFS, "%s: forced packet signing but server does not seem to support it\n",
 798                          __func__);
 799                 return -EOPNOTSUPP;
 800         }
 801         if ((ses->ntlmssp->client_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
 802             !(server_flags & NTLMSSP_NEGOTIATE_KEY_XCH))
 803                 pr_warn_once("%s: authentication has been weakened as server does not support key exchange\n",
 804                              __func__);
 805
 806         ses->ntlmssp->server_flags = server_flags;
 807
 808         memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
 809         /* In particular we can examine sign flags */
 810         /* BB spec says that if AvId field of MsvAvTimestamp is populated then
 811                 we must set the MIC field of the AUTHENTICATE_MESSAGE */
 812
 813         tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset);
 814         tilen = le16_to_cpu(pblob->TargetInfoArray.Length);
 815         if (tioffset > blob_len || tioffset + tilen > blob_len) {
 816                 cifs_dbg(VFS, "tioffset + tilen too high %u + %u\n",
 817                          tioffset, tilen);
 818                 return -EINVAL;
 819         }
 820         if (tilen) {
 821                 ses->auth_key.response = kmemdup(bcc_ptr + tioffset, tilen,
 822                                                  GFP_KERNEL);
 823                 if (!ses->auth_key.response) {
 824                         cifs_dbg(VFS, "Challenge target info alloc failure\n");
 825                         return -ENOMEM;
 826                 }
 827                 ses->auth_key.len = tilen;
 828         }
 829
 830         return 0;
 831 }
 832
 833 static int size_of_ntlmssp_blob(struct cifs_ses *ses, int base_size)
 834 {
 835         int sz = base_size + ses->auth_key.len
 836                 - CIFS_SESS_KEY_SIZE + CIFS_CPHTXT_SIZE + 2;
 837
 838         if (ses->domainName)
 839                 sz += sizeof(__le16) * strnlen(ses->domainName, CIFS_MAX_DOMAINNAME_LEN);
 840         else
 841                 sz += sizeof(__le16);
 842
 843         if (ses->user_name)
 844                 sz += sizeof(__le16) * strnlen(ses->user_name, CIFS_MAX_USERNAME_LEN);
 845         else
 846                 sz += sizeof(__le16);
 847
 848         if (ses->workstation_name[0])
 849                 sz += sizeof(__le16) * strnlen(ses->workstation_name,
 850                                                ntlmssp_workstation_name_size(ses));
 851         else
 852                 sz += sizeof(__le16);
 853
 854         return sz;
 855 }
 856
 857 static inline void cifs_security_buffer_from_str(SECURITY_BUFFER *pbuf,
 858                                                  char *str_value,
 859                                                  int str_length,
 860                                                  unsigned char *pstart,
 861                                                  unsigned char **pcur,
 862                                                  const struct nls_table *nls_cp)
 863 {
 864         unsigned char *tmp = pstart;
 865         int len;
 866
 867         if (!pbuf)
 868                 return;
 869
 870         if (!pcur)
 871                 pcur = &tmp;
 872
 873         if (!str_value) {
 874                 pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
 875                 pbuf->Length = 0;
 876                 pbuf->MaximumLength = 0;
 877                 *pcur += sizeof(__le16);
 878         } else {
 879                 len = cifs_strtoUTF16((__le16 *)*pcur,
 880                                       str_value,
 881                                       str_length,
 882                                       nls_cp);
 883                 len *= sizeof(__le16);
 884                 pbuf->BufferOffset = cpu_to_le32(*pcur - pstart);
 885                 pbuf->Length = cpu_to_le16(len);
 886                 pbuf->MaximumLength = cpu_to_le16(len);
 887                 *pcur += len;
 888         }
 889 }
 890
 891 /* BB Move to ntlmssp.c eventually */
 892
 893 int build_ntlmssp_negotiate_blob(unsigned char **pbuffer,
 894                                  u16 *buflen,
 895                                  struct cifs_ses *ses,
 896                                  struct TCP_Server_Info *server,
 897                                  const struct nls_table *nls_cp)
 898 {
 899         int rc = 0;
 900         NEGOTIATE_MESSAGE *sec_blob;
 901         __u32 flags;
 902         unsigned char *tmp;
 903         int len;
 904
 905         len = size_of_ntlmssp_blob(ses, sizeof(NEGOTIATE_MESSAGE));
 906         *pbuffer = kmalloc(len, GFP_KERNEL);
 907         if (!*pbuffer) {
 908                 rc = -ENOMEM;
 909                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
 910                 *buflen = 0;
 911                 goto setup_ntlm_neg_ret;
 912         }
 913         sec_blob = (NEGOTIATE_MESSAGE *)*pbuffer;
 914
 915         memset(*pbuffer, 0, sizeof(NEGOTIATE_MESSAGE));
 916         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 917         sec_blob->MessageType = NtLmNegotiate;
 918
 919         /* BB is NTLMV2 session security format easier to use here? */
 920         flags = NTLMSSP_NEGOTIATE_56 |  NTLMSSP_REQUEST_TARGET |
 921                 NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 922                 NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
 923                 NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
 924                 NTLMSSP_NEGOTIATE_SIGN;
 925         if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
 926                 flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 927
 928         tmp = *pbuffer + sizeof(NEGOTIATE_MESSAGE);
 929         ses->ntlmssp->client_flags = flags;
 930         sec_blob->NegotiateFlags = cpu_to_le32(flags);
 931
 932         /* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
 933         cifs_security_buffer_from_str(&sec_blob->DomainName,
 934                                       NULL,
 935                                       CIFS_MAX_DOMAINNAME_LEN,
 936                                       *pbuffer, &tmp,
 937                                       nls_cp);
 938
 939         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
 940                                       NULL,
 941                                       CIFS_MAX_WORKSTATION_LEN,
 942                                       *pbuffer, &tmp,
 943                                       nls_cp);
 944
 945         *buflen = tmp - *pbuffer;
 946 setup_ntlm_neg_ret:
 947         return rc;
 948 }
 949
 950 /*
 951  * Build ntlmssp blob with additional fields, such as version,
 952  * supported by modern servers. For safety limit to SMB3 or later
 953  * See notes in MS-NLMP Section 2.2.2.1 e.g.
 954  */
 955 int build_ntlmssp_smb3_negotiate_blob(unsigned char **pbuffer,
 956                                  u16 *buflen,
 957                                  struct cifs_ses *ses,
 958                                  struct TCP_Server_Info *server,
 959                                  const struct nls_table *nls_cp)
 960 {
 961         int rc = 0;
 962         struct negotiate_message *sec_blob;
 963         __u32 flags;
 964         unsigned char *tmp;
 965         int len;
 966
 967         len = size_of_ntlmssp_blob(ses, sizeof(struct negotiate_message));
 968         *pbuffer = kmalloc(len, GFP_KERNEL);
 969         if (!*pbuffer) {
 970                 rc = -ENOMEM;
 971                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
 972                 *buflen = 0;
 973                 goto setup_ntlm_smb3_neg_ret;
 974         }
 975         sec_blob = (struct negotiate_message *)*pbuffer;
 976
 977         memset(*pbuffer, 0, sizeof(struct negotiate_message));
 978         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 979         sec_blob->MessageType = NtLmNegotiate;
 980
 981         /* BB is NTLMV2 session security format easier to use here? */
 982         flags = NTLMSSP_NEGOTIATE_56 |  NTLMSSP_REQUEST_TARGET |
 983                 NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE |
 984                 NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC |
 985                 NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL |
 986                 NTLMSSP_NEGOTIATE_SIGN | NTLMSSP_NEGOTIATE_VERSION;
 987         if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess)
 988                 flags |= NTLMSSP_NEGOTIATE_KEY_XCH;
 989
 990         sec_blob->Version.ProductMajorVersion = LINUX_VERSION_MAJOR;
 991         sec_blob->Version.ProductMinorVersion = LINUX_VERSION_PATCHLEVEL;
 992         sec_blob->Version.ProductBuild = cpu_to_le16(SMB3_PRODUCT_BUILD);
 993         sec_blob->Version.NTLMRevisionCurrent = NTLMSSP_REVISION_W2K3;
 994
 995         tmp = *pbuffer + sizeof(struct negotiate_message);
 996         ses->ntlmssp->client_flags = flags;
 997         sec_blob->NegotiateFlags = cpu_to_le32(flags);
 998
 999         /* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */
1000         cifs_security_buffer_from_str(&sec_blob->DomainName,
1001                                       NULL,
1002                                       CIFS_MAX_DOMAINNAME_LEN,
1003                                       *pbuffer, &tmp,
1004                                       nls_cp);
1005
1006         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1007                                       NULL,
1008                                       CIFS_MAX_WORKSTATION_LEN,
1009                                       *pbuffer, &tmp,
1010                                       nls_cp);
1011
1012         *buflen = tmp - *pbuffer;
1013 setup_ntlm_smb3_neg_ret:
1014         return rc;
1015 }
1016
1017
1018 int build_ntlmssp_auth_blob(unsigned char **pbuffer,
1019                                         u16 *buflen,
1020                                    struct cifs_ses *ses,
1021                                    struct TCP_Server_Info *server,
1022                                    const struct nls_table *nls_cp)
1023 {
1024         int rc;
1025         AUTHENTICATE_MESSAGE *sec_blob;
1026         __u32 flags;
1027         unsigned char *tmp;
1028         int len;
1029
1030         rc = setup_ntlmv2_rsp(ses, nls_cp);
1031         if (rc) {
1032                 cifs_dbg(VFS, "Error %d during NTLMSSP authentication\n", rc);
1033                 *buflen = 0;
1034                 goto setup_ntlmv2_ret;
1035         }
1036
1037         len = size_of_ntlmssp_blob(ses, sizeof(AUTHENTICATE_MESSAGE));
1038         *pbuffer = kmalloc(len, GFP_KERNEL);
1039         if (!*pbuffer) {
1040                 rc = -ENOMEM;
1041                 cifs_dbg(VFS, "Error %d during NTLMSSP allocation\n", rc);
1042                 *buflen = 0;
1043                 goto setup_ntlmv2_ret;
1044         }
1045         sec_blob = (AUTHENTICATE_MESSAGE *)*pbuffer;
1046
1047         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
1048         sec_blob->MessageType = NtLmAuthenticate;
1049
1050         flags = ses->ntlmssp->server_flags | NTLMSSP_REQUEST_TARGET |
1051                 NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED;
1052
1053         tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE);
1054         sec_blob->NegotiateFlags = cpu_to_le32(flags);
1055
1056         sec_blob->LmChallengeResponse.BufferOffset =
1057                                 cpu_to_le32(sizeof(AUTHENTICATE_MESSAGE));
1058         sec_blob->LmChallengeResponse.Length = 0;
1059         sec_blob->LmChallengeResponse.MaximumLength = 0;
1060
1061         sec_blob->NtChallengeResponse.BufferOffset =
1062                                 cpu_to_le32(tmp - *pbuffer);
1063         if (ses->user_name != NULL) {
1064                 memcpy(tmp, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1065                                 ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1066                 tmp += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1067
1068                 sec_blob->NtChallengeResponse.Length =
1069                                 cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1070                 sec_blob->NtChallengeResponse.MaximumLength =
1071                                 cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1072         } else {
1073                 /*
1074                  * don't send an NT Response for anonymous access
1075                  */
1076                 sec_blob->NtChallengeResponse.Length = 0;
1077                 sec_blob->NtChallengeResponse.MaximumLength = 0;
1078         }
1079
1080         cifs_security_buffer_from_str(&sec_blob->DomainName,
1081                                       ses->domainName,
1082                                       CIFS_MAX_DOMAINNAME_LEN,
1083                                       *pbuffer, &tmp,
1084                                       nls_cp);
1085
1086         cifs_security_buffer_from_str(&sec_blob->UserName,
1087                                       ses->user_name,
1088                                       CIFS_MAX_USERNAME_LEN,
1089                                       *pbuffer, &tmp,
1090                                       nls_cp);
1091
1092         cifs_security_buffer_from_str(&sec_blob->WorkstationName,
1093                                       ses->workstation_name,
1094                                       ntlmssp_workstation_name_size(ses),
1095                                       *pbuffer, &tmp,
1096                                       nls_cp);
1097
1098         if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
1099             (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) &&
1100             !calc_seckey(ses)) {
1101                 memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE);
1102                 sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1103                 sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
1104                 sec_blob->SessionKey.MaximumLength =
1105                                 cpu_to_le16(CIFS_CPHTXT_SIZE);
1106                 tmp += CIFS_CPHTXT_SIZE;
1107         } else {
1108                 sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer);
1109                 sec_blob->SessionKey.Length = 0;
1110                 sec_blob->SessionKey.MaximumLength = 0;
1111         }
1112
1113         *buflen = tmp - *pbuffer;
1114 setup_ntlmv2_ret:
1115         return rc;
1116 }
1117
1118 enum securityEnum
1119 cifs_select_sectype(struct TCP_Server_Info *server, enum securityEnum requested)
1120 {
1121         switch (server->negflavor) {
1122         case CIFS_NEGFLAVOR_EXTENDED:
1123                 switch (requested) {
1124                 case Kerberos:
1125                 case RawNTLMSSP:
1126                         return requested;
1127                 case Unspecified:
1128                         if (server->sec_ntlmssp &&
1129                             (global_secflags & CIFSSEC_MAY_NTLMSSP))
1130                                 return RawNTLMSSP;
1131                         if ((server->sec_kerberos || server->sec_mskerberos) &&
1132                             (global_secflags & CIFSSEC_MAY_KRB5))
1133                                 return Kerberos;
1134                         fallthrough;
1135                 default:
1136                         return Unspecified;
1137                 }
1138         case CIFS_NEGFLAVOR_UNENCAP:
1139                 switch (requested) {
1140                 case NTLMv2:
1141                         return requested;
1142                 case Unspecified:
1143                         if (global_secflags & CIFSSEC_MAY_NTLMV2)
1144                                 return NTLMv2;
1145                         break;
1146                 default:
1147                         break;
1148                 }
1149                 fallthrough;
1150         default:
1151                 return Unspecified;
1152         }
1153 }
1154
1155 struct sess_data {
1156         unsigned int xid;
1157         struct cifs_ses *ses;
1158         struct TCP_Server_Info *server;
1159         struct nls_table *nls_cp;
1160         void (*func)(struct sess_data *);
1161         int result;
1162
1163         /* we will send the SMB in three pieces:
1164          * a fixed length beginning part, an optional
1165          * SPNEGO blob (which can be zero length), and a
1166          * last part which will include the strings
1167          * and rest of bcc area. This allows us to avoid
1168          * a large buffer 17K allocation
1169          */
1170         int buf0_type;
1171         struct kvec iov[3];
1172 };
1173
1174 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
1175 static int
1176 sess_alloc_buffer(struct sess_data *sess_data, int wct)
1177 {
1178         int rc;
1179         struct cifs_ses *ses = sess_data->ses;
1180         struct smb_hdr *smb_buf;
1181
1182         rc = small_smb_init_no_tc(SMB_COM_SESSION_SETUP_ANDX, wct, ses,
1183                                   (void **)&smb_buf);
1184
1185         if (rc)
1186                 return rc;
1187
1188         sess_data->iov[0].iov_base = (char *)smb_buf;
1189         sess_data->iov[0].iov_len = be32_to_cpu(smb_buf->smb_buf_length) + 4;
1190         /*
1191          * This variable will be used to clear the buffer
1192          * allocated above in case of any error in the calling function.
1193          */
1194         sess_data->buf0_type = CIFS_SMALL_BUFFER;
1195
1196         /* 2000 big enough to fit max user, domain, NOS name etc. */
1197         sess_data->iov[2].iov_base = kmalloc(2000, GFP_KERNEL);
1198         if (!sess_data->iov[2].iov_base) {
1199                 rc = -ENOMEM;
1200                 goto out_free_smb_buf;
1201         }
1202
1203         return 0;
1204
1205 out_free_smb_buf:
1206         cifs_small_buf_release(smb_buf);
1207         sess_data->iov[0].iov_base = NULL;
1208         sess_data->iov[0].iov_len = 0;
1209         sess_data->buf0_type = CIFS_NO_BUFFER;
1210         return rc;
1211 }
1212
1213 static void
1214 sess_free_buffer(struct sess_data *sess_data)
1215 {
1216
1217         free_rsp_buf(sess_data->buf0_type, sess_data->iov[0].iov_base);
1218         sess_data->buf0_type = CIFS_NO_BUFFER;
1219         kfree(sess_data->iov[2].iov_base);
1220 }
1221
1222 static int
1223 sess_establish_session(struct sess_data *sess_data)
1224 {
1225         struct cifs_ses *ses = sess_data->ses;
1226         struct TCP_Server_Info *server = sess_data->server;
1227
1228         cifs_server_lock(server);
1229         if (!server->session_estab) {
1230                 if (server->sign) {
1231                         server->session_key.response =
1232                                 kmemdup(ses->auth_key.response,
1233                                 ses->auth_key.len, GFP_KERNEL);
1234                         if (!server->session_key.response) {
1235                                 cifs_server_unlock(server);
1236                                 return -ENOMEM;
1237                         }
1238                         server->session_key.len =
1239                                                 ses->auth_key.len;
1240                 }
1241                 server->sequence_number = 0x2;
1242                 server->session_estab = true;
1243         }
1244         cifs_server_unlock(server);
1245
1246         cifs_dbg(FYI, "CIFS session established successfully\n");
1247         return 0;
1248 }
1249
1250 static int
1251 sess_sendreceive(struct sess_data *sess_data)
1252 {
1253         int rc;
1254         struct smb_hdr *smb_buf = (struct smb_hdr *) sess_data->iov[0].iov_base;
1255         __u16 count;
1256         struct kvec rsp_iov = { NULL, 0 };
1257
1258         count = sess_data->iov[1].iov_len + sess_data->iov[2].iov_len;
1259         be32_add_cpu(&smb_buf->smb_buf_length, count);
1260         put_bcc(count, smb_buf);
1261
1262         rc = SendReceive2(sess_data->xid, sess_data->ses,
1263                           sess_data->iov, 3 /* num_iovecs */,
1264                           &sess_data->buf0_type,
1265                           CIFS_LOG_ERROR, &rsp_iov);
1266         cifs_small_buf_release(sess_data->iov[0].iov_base);
1267         memcpy(&sess_data->iov[0], &rsp_iov, sizeof(struct kvec));
1268
1269         return rc;
1270 }
1271
1272 static void
1273 sess_auth_ntlmv2(struct sess_data *sess_data)
1274 {
1275         int rc = 0;
1276         struct smb_hdr *smb_buf;
1277         SESSION_SETUP_ANDX *pSMB;
1278         char *bcc_ptr;
1279         struct cifs_ses *ses = sess_data->ses;
1280         struct TCP_Server_Info *server = sess_data->server;
1281         __u32 capabilities;
1282         __u16 bytes_remaining;
1283
1284         /* old style NTLM sessionsetup */
1285         /* wct = 13 */
1286         rc = sess_alloc_buffer(sess_data, 13);
1287         if (rc)
1288                 goto out;
1289
1290         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1291         bcc_ptr = sess_data->iov[2].iov_base;
1292         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1293
1294         pSMB->req_no_secext.Capabilities = cpu_to_le32(capabilities);
1295
1296         /* LM2 password would be here if we supported it */
1297         pSMB->req_no_secext.CaseInsensitivePasswordLength = 0;
1298
1299         if (ses->user_name != NULL) {
1300                 /* calculate nlmv2 response and session key */
1301                 rc = setup_ntlmv2_rsp(ses, sess_data->nls_cp);
1302                 if (rc) {
1303                         cifs_dbg(VFS, "Error %d during NTLMv2 authentication\n", rc);
1304                         goto out;
1305                 }
1306
1307                 memcpy(bcc_ptr, ses->auth_key.response + CIFS_SESS_KEY_SIZE,
1308                                 ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1309                 bcc_ptr += ses->auth_key.len - CIFS_SESS_KEY_SIZE;
1310
1311                 /* set case sensitive password length after tilen may get
1312                  * assigned, tilen is 0 otherwise.
1313                  */
1314                 pSMB->req_no_secext.CaseSensitivePasswordLength =
1315                         cpu_to_le16(ses->auth_key.len - CIFS_SESS_KEY_SIZE);
1316         } else {
1317                 pSMB->req_no_secext.CaseSensitivePasswordLength = 0;
1318         }
1319
1320         if (ses->capabilities & CAP_UNICODE) {
1321                 if (sess_data->iov[0].iov_len % 2) {
1322                         *bcc_ptr = 0;
1323                         bcc_ptr++;
1324                 }
1325                 unicode_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1326         } else {
1327                 ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1328         }
1329
1330
1331         sess_data->iov[2].iov_len = (long) bcc_ptr -
1332                         (long) sess_data->iov[2].iov_base;
1333
1334         rc = sess_sendreceive(sess_data);
1335         if (rc)
1336                 goto out;
1337
1338         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1339         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1340
1341         if (smb_buf->WordCount != 3) {
1342                 rc = -EIO;
1343                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1344                 goto out;
1345         }
1346
1347         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1348                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1349
1350         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1351         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1352
1353         bytes_remaining = get_bcc(smb_buf);
1354         bcc_ptr = pByteArea(smb_buf);
1355
1356         /* BB check if Unicode and decode strings */
1357         if (bytes_remaining == 0) {
1358                 /* no string area to decode, do nothing */
1359         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1360                 /* unicode string area must be word-aligned */
1361                 if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
1362                         ++bcc_ptr;
1363                         --bytes_remaining;
1364                 }
1365                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1366                                       sess_data->nls_cp);
1367         } else {
1368                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1369                                     sess_data->nls_cp);
1370         }
1371
1372         rc = sess_establish_session(sess_data);
1373 out:
1374         sess_data->result = rc;
1375         sess_data->func = NULL;
1376         sess_free_buffer(sess_data);
1377         kfree(ses->auth_key.response);
1378         ses->auth_key.response = NULL;
1379 }
1380
1381 #ifdef CONFIG_CIFS_UPCALL
1382 static void
1383 sess_auth_kerberos(struct sess_data *sess_data)
1384 {
1385         int rc = 0;
1386         struct smb_hdr *smb_buf;
1387         SESSION_SETUP_ANDX *pSMB;
1388         char *bcc_ptr;
1389         struct cifs_ses *ses = sess_data->ses;
1390         struct TCP_Server_Info *server = sess_data->server;
1391         __u32 capabilities;
1392         __u16 bytes_remaining;
1393         struct key *spnego_key = NULL;
1394         struct cifs_spnego_msg *msg;
1395         u16 blob_len;
1396
1397         /* extended security */
1398         /* wct = 12 */
1399         rc = sess_alloc_buffer(sess_data, 12);
1400         if (rc)
1401                 goto out;
1402
1403         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1404         bcc_ptr = sess_data->iov[2].iov_base;
1405         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1406
1407         spnego_key = cifs_get_spnego_key(ses, server);
1408         if (IS_ERR(spnego_key)) {
1409                 rc = PTR_ERR(spnego_key);
1410                 spnego_key = NULL;
1411                 goto out;
1412         }
1413
1414         msg = spnego_key->payload.data[0];
1415         /*
1416          * check version field to make sure that cifs.upcall is
1417          * sending us a response in an expected form
1418          */
1419         if (msg->version != CIFS_SPNEGO_UPCALL_VERSION) {
1420                 cifs_dbg(VFS, "incorrect version of cifs.upcall (expected %d but got %d)\n",
1421                          CIFS_SPNEGO_UPCALL_VERSION, msg->version);
1422                 rc = -EKEYREJECTED;
1423                 goto out_put_spnego_key;
1424         }
1425
1426         ses->auth_key.response = kmemdup(msg->data, msg->sesskey_len,
1427                                          GFP_KERNEL);
1428         if (!ses->auth_key.response) {
1429                 cifs_dbg(VFS, "Kerberos can't allocate (%u bytes) memory\n",
1430                          msg->sesskey_len);
1431                 rc = -ENOMEM;
1432                 goto out_put_spnego_key;
1433         }
1434         ses->auth_key.len = msg->sesskey_len;
1435
1436         pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1437         capabilities |= CAP_EXTENDED_SECURITY;
1438         pSMB->req.Capabilities = cpu_to_le32(capabilities);
1439         sess_data->iov[1].iov_base = msg->data + msg->sesskey_len;
1440         sess_data->iov[1].iov_len = msg->secblob_len;
1441         pSMB->req.SecurityBlobLength = cpu_to_le16(sess_data->iov[1].iov_len);
1442
1443         if (ses->capabilities & CAP_UNICODE) {
1444                 /* unicode strings must be word aligned */
1445                 if ((sess_data->iov[0].iov_len
1446                         + sess_data->iov[1].iov_len) % 2) {
1447                         *bcc_ptr = 0;
1448                         bcc_ptr++;
1449                 }
1450                 unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1451                 unicode_domain_string(&bcc_ptr, ses, sess_data->nls_cp);
1452         } else {
1453                 /* BB: is this right? */
1454                 ascii_ssetup_strings(&bcc_ptr, ses, sess_data->nls_cp);
1455         }
1456
1457         sess_data->iov[2].iov_len = (long) bcc_ptr -
1458                         (long) sess_data->iov[2].iov_base;
1459
1460         rc = sess_sendreceive(sess_data);
1461         if (rc)
1462                 goto out_put_spnego_key;
1463
1464         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1465         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1466
1467         if (smb_buf->WordCount != 4) {
1468                 rc = -EIO;
1469                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1470                 goto out_put_spnego_key;
1471         }
1472
1473         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1474                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1475
1476         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1477         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1478
1479         bytes_remaining = get_bcc(smb_buf);
1480         bcc_ptr = pByteArea(smb_buf);
1481
1482         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1483         if (blob_len > bytes_remaining) {
1484                 cifs_dbg(VFS, "bad security blob length %d\n",
1485                                 blob_len);
1486                 rc = -EINVAL;
1487                 goto out_put_spnego_key;
1488         }
1489         bcc_ptr += blob_len;
1490         bytes_remaining -= blob_len;
1491
1492         /* BB check if Unicode and decode strings */
1493         if (bytes_remaining == 0) {
1494                 /* no string area to decode, do nothing */
1495         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1496                 /* unicode string area must be word-aligned */
1497                 if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
1498                         ++bcc_ptr;
1499                         --bytes_remaining;
1500                 }
1501                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1502                                       sess_data->nls_cp);
1503         } else {
1504                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1505                                     sess_data->nls_cp);
1506         }
1507
1508         rc = sess_establish_session(sess_data);
1509 out_put_spnego_key:
1510         key_invalidate(spnego_key);
1511         key_put(spnego_key);
1512 out:
1513         sess_data->result = rc;
1514         sess_data->func = NULL;
1515         sess_free_buffer(sess_data);
1516         kfree(ses->auth_key.response);
1517         ses->auth_key.response = NULL;
1518 }
1519
1520 #endif /* ! CONFIG_CIFS_UPCALL */
1521
1522 /*
1523  * The required kvec buffers have to be allocated before calling this
1524  * function.
1525  */
1526 static int
1527 _sess_auth_rawntlmssp_assemble_req(struct sess_data *sess_data)
1528 {
1529         SESSION_SETUP_ANDX *pSMB;
1530         struct cifs_ses *ses = sess_data->ses;
1531         struct TCP_Server_Info *server = sess_data->server;
1532         __u32 capabilities;
1533         char *bcc_ptr;
1534
1535         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1536
1537         capabilities = cifs_ssetup_hdr(ses, server, pSMB);
1538         if ((pSMB->req.hdr.Flags2 & SMBFLG2_UNICODE) == 0) {
1539                 cifs_dbg(VFS, "NTLMSSP requires Unicode support\n");
1540                 return -ENOSYS;
1541         }
1542
1543         pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
1544         capabilities |= CAP_EXTENDED_SECURITY;
1545         pSMB->req.Capabilities |= cpu_to_le32(capabilities);
1546
1547         bcc_ptr = sess_data->iov[2].iov_base;
1548         /* unicode strings must be word aligned */
1549         if ((sess_data->iov[0].iov_len + sess_data->iov[1].iov_len) % 2) {
1550                 *bcc_ptr = 0;
1551                 bcc_ptr++;
1552         }
1553         unicode_oslm_strings(&bcc_ptr, sess_data->nls_cp);
1554
1555         sess_data->iov[2].iov_len = (long) bcc_ptr -
1556                                         (long) sess_data->iov[2].iov_base;
1557
1558         return 0;
1559 }
1560
1561 static void
1562 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data);
1563
1564 static void
1565 sess_auth_rawntlmssp_negotiate(struct sess_data *sess_data)
1566 {
1567         int rc;
1568         struct smb_hdr *smb_buf;
1569         SESSION_SETUP_ANDX *pSMB;
1570         struct cifs_ses *ses = sess_data->ses;
1571         struct TCP_Server_Info *server = sess_data->server;
1572         __u16 bytes_remaining;
1573         char *bcc_ptr;
1574         unsigned char *ntlmsspblob = NULL;
1575         u16 blob_len;
1576
1577         cifs_dbg(FYI, "rawntlmssp session setup negotiate phase\n");
1578
1579         /*
1580          * if memory allocation is successful, caller of this function
1581          * frees it.
1582          */
1583         ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
1584         if (!ses->ntlmssp) {
1585                 rc = -ENOMEM;
1586                 goto out;
1587         }
1588         ses->ntlmssp->sesskey_per_smbsess = false;
1589
1590         /* wct = 12 */
1591         rc = sess_alloc_buffer(sess_data, 12);
1592         if (rc)
1593                 goto out;
1594
1595         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1596
1597         /* Build security blob before we assemble the request */
1598         rc = build_ntlmssp_negotiate_blob(&ntlmsspblob,
1599                                      &blob_len, ses, server,
1600                                      sess_data->nls_cp);
1601         if (rc)
1602                 goto out_free_ntlmsspblob;
1603
1604         sess_data->iov[1].iov_len = blob_len;
1605         sess_data->iov[1].iov_base = ntlmsspblob;
1606         pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1607
1608         rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1609         if (rc)
1610                 goto out_free_ntlmsspblob;
1611
1612         rc = sess_sendreceive(sess_data);
1613
1614         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1615         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1616
1617         /* If true, rc here is expected and not an error */
1618         if (sess_data->buf0_type != CIFS_NO_BUFFER &&
1619             smb_buf->Status.CifsError ==
1620                         cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))
1621                 rc = 0;
1622
1623         if (rc)
1624                 goto out_free_ntlmsspblob;
1625
1626         cifs_dbg(FYI, "rawntlmssp session setup challenge phase\n");
1627
1628         if (smb_buf->WordCount != 4) {
1629                 rc = -EIO;
1630                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1631                 goto out_free_ntlmsspblob;
1632         }
1633
1634         ses->Suid = smb_buf->Uid;   /* UID left in wire format (le) */
1635         cifs_dbg(FYI, "UID = %llu\n", ses->Suid);
1636
1637         bytes_remaining = get_bcc(smb_buf);
1638         bcc_ptr = pByteArea(smb_buf);
1639
1640         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1641         if (blob_len > bytes_remaining) {
1642                 cifs_dbg(VFS, "bad security blob length %d\n",
1643                                 blob_len);
1644                 rc = -EINVAL;
1645                 goto out_free_ntlmsspblob;
1646         }
1647
1648         rc = decode_ntlmssp_challenge(bcc_ptr, blob_len, ses);
1649
1650 out_free_ntlmsspblob:
1651         kfree(ntlmsspblob);
1652 out:
1653         sess_free_buffer(sess_data);
1654
1655         if (!rc) {
1656                 sess_data->func = sess_auth_rawntlmssp_authenticate;
1657                 return;
1658         }
1659
1660         /* Else error. Cleanup */
1661         kfree(ses->auth_key.response);
1662         ses->auth_key.response = NULL;
1663         kfree(ses->ntlmssp);
1664         ses->ntlmssp = NULL;
1665
1666         sess_data->func = NULL;
1667         sess_data->result = rc;
1668 }
1669
1670 static void
1671 sess_auth_rawntlmssp_authenticate(struct sess_data *sess_data)
1672 {
1673         int rc;
1674         struct smb_hdr *smb_buf;
1675         SESSION_SETUP_ANDX *pSMB;
1676         struct cifs_ses *ses = sess_data->ses;
1677         struct TCP_Server_Info *server = sess_data->server;
1678         __u16 bytes_remaining;
1679         char *bcc_ptr;
1680         unsigned char *ntlmsspblob = NULL;
1681         u16 blob_len;
1682
1683         cifs_dbg(FYI, "rawntlmssp session setup authenticate phase\n");
1684
1685         /* wct = 12 */
1686         rc = sess_alloc_buffer(sess_data, 12);
1687         if (rc)
1688                 goto out;
1689
1690         /* Build security blob before we assemble the request */
1691         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1692         smb_buf = (struct smb_hdr *)pSMB;
1693         rc = build_ntlmssp_auth_blob(&ntlmsspblob,
1694                                         &blob_len, ses, server,
1695                                         sess_data->nls_cp);
1696         if (rc)
1697                 goto out_free_ntlmsspblob;
1698         sess_data->iov[1].iov_len = blob_len;
1699         sess_data->iov[1].iov_base = ntlmsspblob;
1700         pSMB->req.SecurityBlobLength = cpu_to_le16(blob_len);
1701         /*
1702          * Make sure that we tell the server that we are using
1703          * the uid that it just gave us back on the response
1704          * (challenge)
1705          */
1706         smb_buf->Uid = ses->Suid;
1707
1708         rc = _sess_auth_rawntlmssp_assemble_req(sess_data);
1709         if (rc)
1710                 goto out_free_ntlmsspblob;
1711
1712         rc = sess_sendreceive(sess_data);
1713         if (rc)
1714                 goto out_free_ntlmsspblob;
1715
1716         pSMB = (SESSION_SETUP_ANDX *)sess_data->iov[0].iov_base;
1717         smb_buf = (struct smb_hdr *)sess_data->iov[0].iov_base;
1718         if (smb_buf->WordCount != 4) {
1719                 rc = -EIO;
1720                 cifs_dbg(VFS, "bad word count %d\n", smb_buf->WordCount);
1721                 goto out_free_ntlmsspblob;
1722         }
1723
1724         if (le16_to_cpu(pSMB->resp.Action) & GUEST_LOGIN)
1725                 cifs_dbg(FYI, "Guest login\n"); /* BB mark SesInfo struct? */
1726
1727         if (ses->Suid != smb_buf->Uid) {
1728                 ses->Suid = smb_buf->Uid;
1729                 cifs_dbg(FYI, "UID changed! new UID = %llu\n", ses->Suid);
1730         }
1731
1732         bytes_remaining = get_bcc(smb_buf);
1733         bcc_ptr = pByteArea(smb_buf);
1734         blob_len = le16_to_cpu(pSMB->resp.SecurityBlobLength);
1735         if (blob_len > bytes_remaining) {
1736                 cifs_dbg(VFS, "bad security blob length %d\n",
1737                                 blob_len);
1738                 rc = -EINVAL;
1739                 goto out_free_ntlmsspblob;
1740         }
1741         bcc_ptr += blob_len;
1742         bytes_remaining -= blob_len;
1743
1744
1745         /* BB check if Unicode and decode strings */
1746         if (bytes_remaining == 0) {
1747                 /* no string area to decode, do nothing */
1748         } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) {
1749                 /* unicode string area must be word-aligned */
1750                 if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) {
1751                         ++bcc_ptr;
1752                         --bytes_remaining;
1753                 }
1754                 decode_unicode_ssetup(&bcc_ptr, bytes_remaining, ses,
1755                                       sess_data->nls_cp);
1756         } else {
1757                 decode_ascii_ssetup(&bcc_ptr, bytes_remaining, ses,
1758                                     sess_data->nls_cp);
1759         }
1760
1761 out_free_ntlmsspblob:
1762         kfree(ntlmsspblob);
1763 out:
1764         sess_free_buffer(sess_data);
1765
1766         if (!rc)
1767                 rc = sess_establish_session(sess_data);
1768
1769         /* Cleanup */
1770         kfree(ses->auth_key.response);
1771         ses->auth_key.response = NULL;
1772         kfree(ses->ntlmssp);
1773         ses->ntlmssp = NULL;
1774
1775         sess_data->func = NULL;
1776         sess_data->result = rc;
1777 }
1778
1779 static int select_sec(struct sess_data *sess_data)
1780 {
1781         int type;
1782         struct cifs_ses *ses = sess_data->ses;
1783         struct TCP_Server_Info *server = sess_data->server;
1784
1785         type = cifs_select_sectype(server, ses->sectype);
1786         cifs_dbg(FYI, "sess setup type %d\n", type);
1787         if (type == Unspecified) {
1788                 cifs_dbg(VFS, "Unable to select appropriate authentication method!\n");
1789                 return -EINVAL;
1790         }
1791
1792         switch (type) {
1793         case NTLMv2:
1794                 sess_data->func = sess_auth_ntlmv2;
1795                 break;
1796         case Kerberos:
1797 #ifdef CONFIG_CIFS_UPCALL
1798                 sess_data->func = sess_auth_kerberos;
1799                 break;
1800 #else
1801                 cifs_dbg(VFS, "Kerberos negotiated but upcall support disabled!\n");
1802                 return -ENOSYS;
1803 #endif /* CONFIG_CIFS_UPCALL */
1804         case RawNTLMSSP:
1805                 sess_data->func = sess_auth_rawntlmssp_negotiate;
1806                 break;
1807         default:
1808                 cifs_dbg(VFS, "secType %d not supported!\n", type);
1809                 return -ENOSYS;
1810         }
1811
1812         return 0;
1813 }
1814
1815 int CIFS_SessSetup(const unsigned int xid, struct cifs_ses *ses,
1816                    struct TCP_Server_Info *server,
1817                    const struct nls_table *nls_cp)
1818 {
1819         int rc = 0;
1820         struct sess_data *sess_data;
1821
1822         if (ses == NULL) {
1823                 WARN(1, "%s: ses == NULL!", __func__);
1824                 return -EINVAL;
1825         }
1826
1827         sess_data = kzalloc(sizeof(struct sess_data), GFP_KERNEL);
1828         if (!sess_data)
1829                 return -ENOMEM;
1830
1831         sess_data->xid = xid;
1832         sess_data->ses = ses;
1833         sess_data->server = server;
1834         sess_data->buf0_type = CIFS_NO_BUFFER;
1835         sess_data->nls_cp = (struct nls_table *) nls_cp;
1836
1837         rc = select_sec(sess_data);
1838         if (rc)
1839                 goto out;
1840
1841         while (sess_data->func)
1842                 sess_data->func(sess_data);
1843
1844         /* Store result before we free sess_data */
1845         rc = sess_data->result;
1846
1847 out:
1848         kfree(sess_data);
1849         return rc;
1850 }
1851 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */