fs/cifs/connect.c

   1 /*
   2  *   fs/cifs/connect.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Lesser General Public License as published
   9  *   by the Free Software Foundation; either version 2.1 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This library is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15  *   the GNU Lesser General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Lesser General Public License
  18  *   along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21 #include <linux/fs.h>
  22 #include <linux/net.h>
  23 #include <linux/string.h>
  24 #include <linux/sched/mm.h>
  25 #include <linux/sched/signal.h>
  26 #include <linux/list.h>
  27 #include <linux/wait.h>
  28 #include <linux/slab.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/ctype.h>
  31 #include <linux/utsname.h>
  32 #include <linux/mempool.h>
  33 #include <linux/delay.h>
  34 #include <linux/completion.h>
  35 #include <linux/kthread.h>
  36 #include <linux/pagevec.h>
  37 #include <linux/freezer.h>
  38 #include <linux/namei.h>
  39 #include <linux/uuid.h>
  40 #include <linux/uaccess.h>
  41 #include <asm/processor.h>
  42 #include <linux/inet.h>
  43 #include <linux/module.h>
  44 #include <keys/user-type.h>
  45 #include <net/ipv6.h>
  46 #include <linux/parser.h>
  47 #include <linux/bvec.h>
  48 #include "cifspdu.h"
  49 #include "cifsglob.h"
  50 #include "cifsproto.h"
  51 #include "cifs_unicode.h"
  52 #include "cifs_debug.h"
  53 #include "cifs_fs_sb.h"
  54 #include "ntlmssp.h"
  55 #include "nterr.h"
  56 #include "rfc1002pdu.h"
  57 #include "fscache.h"
  58 #include "smb2proto.h"
  59 #include "smbdirect.h"
  60 #include "dns_resolve.h"
  61 #ifdef CONFIG_CIFS_DFS_UPCALL
  62 #include "dfs_cache.h"
  63 #endif
  64 #include "fs_context.h"
  65 #include "cifs_swn.h"
  66
  67 extern mempool_t *cifs_req_poolp;
  68 extern bool disable_legacy_dialects;
  69
  70 /* FIXME: should these be tunable? */
  71 #define TLINK_ERROR_EXPIRE      (1 * HZ)
  72 #define TLINK_IDLE_EXPIRE       (600 * HZ)
  73
  74 /* Drop the connection to not overload the server */
  75 #define NUM_STATUS_IO_TIMEOUT   5
  76
  77 static int ip_connect(struct TCP_Server_Info *server);
  78 static int generic_ip_connect(struct TCP_Server_Info *server);
  79 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  80 static void cifs_prune_tlinks(struct work_struct *work);
  81
  82 /*
  83  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  84  * get their ip addresses changed at some point.
  85  *
  86  * This should be called with server->srv_mutex held.
  87  */
  88 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  89 {
  90         int rc;
  91         int len;
  92         char *unc, *ipaddr = NULL;
  93
  94         if (!server->hostname)
  95                 return -EINVAL;
  96
  97         len = strlen(server->hostname) + 3;
  98
  99         unc = kmalloc(len, GFP_KERNEL);
 100         if (!unc) {
 101                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
 102                 return -ENOMEM;
 103         }
 104         scnprintf(unc, len, "\\\\%s", server->hostname);
 105
 106         rc = dns_resolve_server_name_to_ip(unc, &ipaddr);
 107         kfree(unc);
 108
 109         if (rc < 0) {
 110                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 111                          __func__, server->hostname, rc);
 112                 return rc;
 113         }
 114
 115         spin_lock(&cifs_tcp_ses_lock);
 116         rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 117                                   strlen(ipaddr));
 118         spin_unlock(&cifs_tcp_ses_lock);
 119         kfree(ipaddr);
 120
 121         return !rc ? -1 : 0;
 122 }
 123
 124 #ifdef CONFIG_CIFS_DFS_UPCALL
 125 /* These functions must be called with server->srv_mutex held */
 126 static void reconn_set_next_dfs_target(struct TCP_Server_Info *server,
 127                                        struct cifs_sb_info *cifs_sb,
 128                                        struct dfs_cache_tgt_list *tgt_list,
 129                                        struct dfs_cache_tgt_iterator **tgt_it)
 130 {
 131         const char *name;
 132         int rc;
 133
 134         if (!cifs_sb || !cifs_sb->origin_fullpath)
 135                 return;
 136
 137         if (!*tgt_it) {
 138                 *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
 139         } else {
 140                 *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it);
 141                 if (!*tgt_it)
 142                         *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
 143         }
 144
 145         cifs_dbg(FYI, "%s: UNC: %s\n", __func__, cifs_sb->origin_fullpath);
 146
 147         name = dfs_cache_get_tgt_name(*tgt_it);
 148
 149         kfree(server->hostname);
 150
 151         server->hostname = extract_hostname(name);
 152         if (IS_ERR(server->hostname)) {
 153                 cifs_dbg(FYI,
 154                          "%s: failed to extract hostname from target: %ld\n",
 155                          __func__, PTR_ERR(server->hostname));
 156                 return;
 157         }
 158
 159         rc = reconn_set_ipaddr_from_hostname(server);
 160         if (rc) {
 161                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 162                          __func__, rc);
 163         }
 164 }
 165
 166 static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
 167                                            struct dfs_cache_tgt_list *tl)
 168 {
 169         if (!cifs_sb->origin_fullpath)
 170                 return -EOPNOTSUPP;
 171         return dfs_cache_noreq_find(cifs_sb->origin_fullpath + 1, NULL, tl);
 172 }
 173 #endif
 174
 175 /*
 176  * cifs tcp session reconnection
 177  *
 178  * mark tcp session as reconnecting so temporarily locked
 179  * mark all smb sessions as reconnecting for tcp session
 180  * reconnect tcp session
 181  * wake up waiters on reconnection? - (not needed currently)
 182  */
 183 int
 184 cifs_reconnect(struct TCP_Server_Info *server)
 185 {
 186         int rc = 0;
 187         struct list_head *tmp, *tmp2;
 188         struct cifs_ses *ses;
 189         struct cifs_tcon *tcon;
 190         struct mid_q_entry *mid_entry;
 191         struct list_head retry_list;
 192 #ifdef CONFIG_CIFS_DFS_UPCALL
 193         struct super_block *sb = NULL;
 194         struct cifs_sb_info *cifs_sb = NULL;
 195         struct dfs_cache_tgt_list tgt_list = {0};
 196         struct dfs_cache_tgt_iterator *tgt_it = NULL;
 197 #endif
 198
 199         spin_lock(&GlobalMid_Lock);
 200         server->nr_targets = 1;
 201 #ifdef CONFIG_CIFS_DFS_UPCALL
 202         spin_unlock(&GlobalMid_Lock);
 203         sb = cifs_get_tcp_super(server);
 204         if (IS_ERR(sb)) {
 205                 rc = PTR_ERR(sb);
 206                 cifs_dbg(FYI, "%s: will not do DFS failover: rc = %d\n",
 207                          __func__, rc);
 208                 sb = NULL;
 209         } else {
 210                 cifs_sb = CIFS_SB(sb);
 211                 rc = reconn_setup_dfs_targets(cifs_sb, &tgt_list);
 212                 if (rc) {
 213                         cifs_sb = NULL;
 214                         if (rc != -EOPNOTSUPP) {
 215                                 cifs_server_dbg(VFS, "%s: no target servers for DFS failover\n",
 216                                                 __func__);
 217                         }
 218                 } else {
 219                         server->nr_targets = dfs_cache_get_nr_tgts(&tgt_list);
 220                 }
 221         }
 222         cifs_dbg(FYI, "%s: will retry %d target(s)\n", __func__,
 223                  server->nr_targets);
 224         spin_lock(&GlobalMid_Lock);
 225 #endif
 226         if (server->tcpStatus == CifsExiting) {
 227                 /* the demux thread will exit normally
 228                 next time through the loop */
 229                 spin_unlock(&GlobalMid_Lock);
 230 #ifdef CONFIG_CIFS_DFS_UPCALL
 231                 dfs_cache_free_tgts(&tgt_list);
 232                 cifs_put_tcp_super(sb);
 233 #endif
 234                 wake_up(&server->response_q);
 235                 return rc;
 236         } else
 237                 server->tcpStatus = CifsNeedReconnect;
 238         spin_unlock(&GlobalMid_Lock);
 239         server->maxBuf = 0;
 240         server->max_read = 0;
 241
 242         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 243         trace_smb3_reconnect(server->CurrentMid, server->conn_id, server->hostname);
 244
 245         /* before reconnecting the tcp session, mark the smb session (uid)
 246                 and the tid bad so they are not used until reconnected */
 247         cifs_dbg(FYI, "%s: marking sessions and tcons for reconnect\n",
 248                  __func__);
 249         spin_lock(&cifs_tcp_ses_lock);
 250         list_for_each(tmp, &server->smb_ses_list) {
 251                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 252                 ses->need_reconnect = true;
 253                 list_for_each(tmp2, &ses->tcon_list) {
 254                         tcon = list_entry(tmp2, struct cifs_tcon, tcon_list);
 255                         tcon->need_reconnect = true;
 256                 }
 257                 if (ses->tcon_ipc)
 258                         ses->tcon_ipc->need_reconnect = true;
 259         }
 260         spin_unlock(&cifs_tcp_ses_lock);
 261
 262         /* do not want to be sending data on a socket we are freeing */
 263         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 264         mutex_lock(&server->srv_mutex);
 265         if (server->ssocket) {
 266                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n",
 267                          server->ssocket->state, server->ssocket->flags);
 268                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 269                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n",
 270                          server->ssocket->state, server->ssocket->flags);
 271                 sock_release(server->ssocket);
 272                 server->ssocket = NULL;
 273         }
 274         server->sequence_number = 0;
 275         server->session_estab = false;
 276         kfree(server->session_key.response);
 277         server->session_key.response = NULL;
 278         server->session_key.len = 0;
 279         server->lstrp = jiffies;
 280
 281         /* mark submitted MIDs for retry and issue callback */
 282         INIT_LIST_HEAD(&retry_list);
 283         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 284         spin_lock(&GlobalMid_Lock);
 285         list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 286                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 287                 kref_get(&mid_entry->refcount);
 288                 if (mid_entry->mid_state == MID_REQUEST_SUBMITTED)
 289                         mid_entry->mid_state = MID_RETRY_NEEDED;
 290                 list_move(&mid_entry->qhead, &retry_list);
 291                 mid_entry->mid_flags |= MID_DELETED;
 292         }
 293         spin_unlock(&GlobalMid_Lock);
 294         mutex_unlock(&server->srv_mutex);
 295
 296         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 297         list_for_each_safe(tmp, tmp2, &retry_list) {
 298                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 299                 list_del_init(&mid_entry->qhead);
 300                 mid_entry->callback(mid_entry);
 301                 cifs_mid_q_entry_release(mid_entry);
 302         }
 303
 304         if (cifs_rdma_enabled(server)) {
 305                 mutex_lock(&server->srv_mutex);
 306                 smbd_destroy(server);
 307                 mutex_unlock(&server->srv_mutex);
 308         }
 309
 310         do {
 311                 try_to_freeze();
 312
 313                 mutex_lock(&server->srv_mutex);
 314
 315
 316                 if (!cifs_swn_set_server_dstaddr(server)) {
 317 #ifdef CONFIG_CIFS_DFS_UPCALL
 318                 if (cifs_sb && cifs_sb->origin_fullpath)
 319                         /*
 320                          * Set up next DFS target server (if any) for reconnect. If DFS
 321                          * feature is disabled, then we will retry last server we
 322                          * connected to before.
 323                          */
 324                         reconn_set_next_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);
 325                 else {
 326 #endif
 327                         /*
 328                          * Resolve the hostname again to make sure that IP address is up-to-date.
 329                          */
 330                         rc = reconn_set_ipaddr_from_hostname(server);
 331                         if (rc) {
 332                                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 333                                                 __func__, rc);
 334                         }
 335
 336 #ifdef CONFIG_CIFS_DFS_UPCALL
 337                 }
 338 #endif
 339
 340
 341                 }
 342
 343                 if (cifs_rdma_enabled(server))
 344                         rc = smbd_reconnect(server);
 345                 else
 346                         rc = generic_ip_connect(server);
 347                 if (rc) {
 348                         cifs_dbg(FYI, "reconnect error %d\n", rc);
 349                         mutex_unlock(&server->srv_mutex);
 350                         msleep(3000);
 351                 } else {
 352                         atomic_inc(&tcpSesReconnectCount);
 353                         set_credits(server, 1);
 354                         spin_lock(&GlobalMid_Lock);
 355                         if (server->tcpStatus != CifsExiting)
 356                                 server->tcpStatus = CifsNeedNegotiate;
 357                         spin_unlock(&GlobalMid_Lock);
 358                         cifs_swn_reset_server_dstaddr(server);
 359                         mutex_unlock(&server->srv_mutex);
 360                 }
 361         } while (server->tcpStatus == CifsNeedReconnect);
 362
 363 #ifdef CONFIG_CIFS_DFS_UPCALL
 364         if (tgt_it) {
 365                 rc = dfs_cache_noreq_update_tgthint(cifs_sb->origin_fullpath + 1,
 366                                                     tgt_it);
 367                 if (rc) {
 368                         cifs_server_dbg(VFS, "%s: failed to update DFS target hint: rc = %d\n",
 369                                  __func__, rc);
 370                 }
 371                 rc = dfs_cache_update_vol(cifs_sb->origin_fullpath, server);
 372                 if (rc) {
 373                         cifs_server_dbg(VFS, "%s: failed to update vol info in DFS cache: rc = %d\n",
 374                                  __func__, rc);
 375                 }
 376                 dfs_cache_free_tgts(&tgt_list);
 377
 378         }
 379
 380         cifs_put_tcp_super(sb);
 381 #endif
 382         if (server->tcpStatus == CifsNeedNegotiate)
 383                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 384
 385         wake_up(&server->response_q);
 386         return rc;
 387 }
 388
 389 static void
 390 cifs_echo_request(struct work_struct *work)
 391 {
 392         int rc;
 393         struct TCP_Server_Info *server = container_of(work,
 394                                         struct TCP_Server_Info, echo.work);
 395         unsigned long echo_interval;
 396
 397         /*
 398          * If we need to renegotiate, set echo interval to zero to
 399          * immediately call echo service where we can renegotiate.
 400          */
 401         if (server->tcpStatus == CifsNeedNegotiate)
 402                 echo_interval = 0;
 403         else
 404                 echo_interval = server->echo_interval;
 405
 406         /*
 407          * We cannot send an echo if it is disabled.
 408          * Also, no need to ping if we got a response recently.
 409          */
 410
 411         if (server->tcpStatus == CifsNeedReconnect ||
 412             server->tcpStatus == CifsExiting ||
 413             server->tcpStatus == CifsNew ||
 414             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 415             time_before(jiffies, server->lstrp + echo_interval - HZ))
 416                 goto requeue_echo;
 417
 418         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 419         if (rc)
 420                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 421                          server->hostname);
 422
 423         /* Check witness registrations */
 424         cifs_swn_check();
 425
 426 requeue_echo:
 427         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 428 }
 429
 430 static bool
 431 allocate_buffers(struct TCP_Server_Info *server)
 432 {
 433         if (!server->bigbuf) {
 434                 server->bigbuf = (char *)cifs_buf_get();
 435                 if (!server->bigbuf) {
 436                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 437                         msleep(3000);
 438                         /* retry will check if exiting */
 439                         return false;
 440                 }
 441         } else if (server->large_buf) {
 442                 /* we are reusing a dirty large buf, clear its start */
 443                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 444         }
 445
 446         if (!server->smallbuf) {
 447                 server->smallbuf = (char *)cifs_small_buf_get();
 448                 if (!server->smallbuf) {
 449                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 450                         msleep(1000);
 451                         /* retry will check if exiting */
 452                         return false;
 453                 }
 454                 /* beginning of smb buffer is cleared in our buf_get */
 455         } else {
 456                 /* if existing small buf clear beginning */
 457                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 458         }
 459
 460         return true;
 461 }
 462
 463 static bool
 464 server_unresponsive(struct TCP_Server_Info *server)
 465 {
 466         /*
 467          * We need to wait 3 echo intervals to make sure we handle such
 468          * situations right:
 469          * 1s  client sends a normal SMB request
 470          * 2s  client gets a response
 471          * 30s echo workqueue job pops, and decides we got a response recently
 472          *     and don't need to send another
 473          * ...
 474          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 475          *     a response in >60s.
 476          */
 477         if ((server->tcpStatus == CifsGood ||
 478             server->tcpStatus == CifsNeedNegotiate) &&
 479             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 480                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 481                          (3 * server->echo_interval) / HZ);
 482                 cifs_reconnect(server);
 483                 return true;
 484         }
 485
 486         return false;
 487 }
 488
 489 static inline bool
 490 zero_credits(struct TCP_Server_Info *server)
 491 {
 492         int val;
 493
 494         spin_lock(&server->req_lock);
 495         val = server->credits + server->echo_credits + server->oplock_credits;
 496         if (server->in_flight == 0 && val == 0) {
 497                 spin_unlock(&server->req_lock);
 498                 return true;
 499         }
 500         spin_unlock(&server->req_lock);
 501         return false;
 502 }
 503
 504 static int
 505 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 506 {
 507         int length = 0;
 508         int total_read;
 509
 510         smb_msg->msg_control = NULL;
 511         smb_msg->msg_controllen = 0;
 512
 513         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 514                 try_to_freeze();
 515
 516                 /* reconnect if no credits and no requests in flight */
 517                 if (zero_credits(server)) {
 518                         cifs_reconnect(server);
 519                         return -ECONNABORTED;
 520                 }
 521
 522                 if (server_unresponsive(server))
 523                         return -ECONNABORTED;
 524                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 525                         length = smbd_recv(server->smbd_conn, smb_msg);
 526                 else
 527                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 528
 529                 if (server->tcpStatus == CifsExiting)
 530                         return -ESHUTDOWN;
 531
 532                 if (server->tcpStatus == CifsNeedReconnect) {
 533                         cifs_reconnect(server);
 534                         return -ECONNABORTED;
 535                 }
 536
 537                 if (length == -ERESTARTSYS ||
 538                     length == -EAGAIN ||
 539                     length == -EINTR) {
 540                         /*
 541                          * Minimum sleep to prevent looping, allowing socket
 542                          * to clear and app threads to set tcpStatus
 543                          * CifsNeedReconnect if server hung.
 544                          */
 545                         usleep_range(1000, 2000);
 546                         length = 0;
 547                         continue;
 548                 }
 549
 550                 if (length <= 0) {
 551                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 552                         cifs_reconnect(server);
 553                         return -ECONNABORTED;
 554                 }
 555         }
 556         return total_read;
 557 }
 558
 559 int
 560 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 561                       unsigned int to_read)
 562 {
 563         struct msghdr smb_msg;
 564         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 565         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 566
 567         return cifs_readv_from_socket(server, &smb_msg);
 568 }
 569
 570 ssize_t
 571 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 572 {
 573         struct msghdr smb_msg;
 574
 575         /*
 576          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 577          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 578          *  so little to initialize in struct msghdr
 579          */
 580         smb_msg.msg_name = NULL;
 581         smb_msg.msg_namelen = 0;
 582         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 583
 584         return cifs_readv_from_socket(server, &smb_msg);
 585 }
 586
 587 int
 588 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 589         unsigned int page_offset, unsigned int to_read)
 590 {
 591         struct msghdr smb_msg;
 592         struct bio_vec bv = {
 593                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 594         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 595         return cifs_readv_from_socket(server, &smb_msg);
 596 }
 597
 598 static bool
 599 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 600 {
 601         /*
 602          * The first byte big endian of the length field,
 603          * is actually not part of the length but the type
 604          * with the most common, zero, as regular data.
 605          */
 606         switch (type) {
 607         case RFC1002_SESSION_MESSAGE:
 608                 /* Regular SMB response */
 609                 return true;
 610         case RFC1002_SESSION_KEEP_ALIVE:
 611                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 612                 break;
 613         case RFC1002_POSITIVE_SESSION_RESPONSE:
 614                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 615                 break;
 616         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 617                 /*
 618                  * We get this from Windows 98 instead of an error on
 619                  * SMB negprot response.
 620                  */
 621                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 622                 /* give server a second to clean up */
 623                 msleep(1000);
 624                 /*
 625                  * Always try 445 first on reconnect since we get NACK
 626                  * on some if we ever connected to port 139 (the NACK
 627                  * is since we do not begin with RFC1001 session
 628                  * initialize frame).
 629                  */
 630                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 631                 cifs_reconnect(server);
 632                 break;
 633         default:
 634                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 635                 cifs_reconnect(server);
 636         }
 637
 638         return false;
 639 }
 640
 641 void
 642 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 643 {
 644 #ifdef CONFIG_CIFS_STATS2
 645         mid->when_received = jiffies;
 646 #endif
 647         spin_lock(&GlobalMid_Lock);
 648         if (!malformed)
 649                 mid->mid_state = MID_RESPONSE_RECEIVED;
 650         else
 651                 mid->mid_state = MID_RESPONSE_MALFORMED;
 652         /*
 653          * Trying to handle/dequeue a mid after the send_recv()
 654          * function has finished processing it is a bug.
 655          */
 656         if (mid->mid_flags & MID_DELETED)
 657                 pr_warn_once("trying to dequeue a deleted mid\n");
 658         else {
 659                 list_del_init(&mid->qhead);
 660                 mid->mid_flags |= MID_DELETED;
 661         }
 662         spin_unlock(&GlobalMid_Lock);
 663 }
 664
 665 static unsigned int
 666 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 667 {
 668         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 669
 670         /*
 671          * SMB1 does not use credits.
 672          */
 673         if (server->vals->header_preamble_size)
 674                 return 0;
 675
 676         return le16_to_cpu(shdr->CreditRequest);
 677 }
 678
 679 static void
 680 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 681            char *buf, int malformed)
 682 {
 683         if (server->ops->check_trans2 &&
 684             server->ops->check_trans2(mid, server, buf, malformed))
 685                 return;
 686         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 687         mid->resp_buf = buf;
 688         mid->large_buf = server->large_buf;
 689         /* Was previous buf put in mpx struct for multi-rsp? */
 690         if (!mid->multiRsp) {
 691                 /* smb buffer will be freed by user thread */
 692                 if (server->large_buf)
 693                         server->bigbuf = NULL;
 694                 else
 695                         server->smallbuf = NULL;
 696         }
 697         dequeue_mid(mid, malformed);
 698 }
 699
 700 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 701 {
 702         int length;
 703
 704         /* take it off the list, if it's not already */
 705         spin_lock(&cifs_tcp_ses_lock);
 706         list_del_init(&server->tcp_ses_list);
 707         spin_unlock(&cifs_tcp_ses_lock);
 708
 709         cancel_delayed_work_sync(&server->echo);
 710
 711         spin_lock(&GlobalMid_Lock);
 712         server->tcpStatus = CifsExiting;
 713         spin_unlock(&GlobalMid_Lock);
 714         wake_up_all(&server->response_q);
 715
 716         /* check if we have blocked requests that need to free */
 717         spin_lock(&server->req_lock);
 718         if (server->credits <= 0)
 719                 server->credits = 1;
 720         spin_unlock(&server->req_lock);
 721         /*
 722          * Although there should not be any requests blocked on this queue it
 723          * can not hurt to be paranoid and try to wake up requests that may
 724          * haven been blocked when more than 50 at time were on the wire to the
 725          * same server - they now will see the session is in exit state and get
 726          * out of SendReceive.
 727          */
 728         wake_up_all(&server->request_q);
 729         /* give those requests time to exit */
 730         msleep(125);
 731         if (cifs_rdma_enabled(server))
 732                 smbd_destroy(server);
 733         if (server->ssocket) {
 734                 sock_release(server->ssocket);
 735                 server->ssocket = NULL;
 736         }
 737
 738         if (!list_empty(&server->pending_mid_q)) {
 739                 struct list_head dispose_list;
 740                 struct mid_q_entry *mid_entry;
 741                 struct list_head *tmp, *tmp2;
 742
 743                 INIT_LIST_HEAD(&dispose_list);
 744                 spin_lock(&GlobalMid_Lock);
 745                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 746                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 747                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 748                         kref_get(&mid_entry->refcount);
 749                         mid_entry->mid_state = MID_SHUTDOWN;
 750                         list_move(&mid_entry->qhead, &dispose_list);
 751                         mid_entry->mid_flags |= MID_DELETED;
 752                 }
 753                 spin_unlock(&GlobalMid_Lock);
 754
 755                 /* now walk dispose list and issue callbacks */
 756                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 757                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 758                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 759                         list_del_init(&mid_entry->qhead);
 760                         mid_entry->callback(mid_entry);
 761                         cifs_mid_q_entry_release(mid_entry);
 762                 }
 763                 /* 1/8th of sec is more than enough time for them to exit */
 764                 msleep(125);
 765         }
 766
 767         if (!list_empty(&server->pending_mid_q)) {
 768                 /*
 769                  * mpx threads have not exited yet give them at least the smb
 770                  * send timeout time for long ops.
 771                  *
 772                  * Due to delays on oplock break requests, we need to wait at
 773                  * least 45 seconds before giving up on a request getting a
 774                  * response and going ahead and killing cifsd.
 775                  */
 776                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 777                 msleep(46000);
 778                 /*
 779                  * If threads still have not exited they are probably never
 780                  * coming home not much else we can do but free the memory.
 781                  */
 782         }
 783
 784         kfree(server->hostname);
 785         kfree(server);
 786
 787         length = atomic_dec_return(&tcpSesAllocCount);
 788         if (length > 0)
 789                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 790 }
 791
 792 static int
 793 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 794 {
 795         int length;
 796         char *buf = server->smallbuf;
 797         unsigned int pdu_length = server->pdu_size;
 798
 799         /* make sure this will fit in a large buffer */
 800         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
 801                 server->vals->header_preamble_size) {
 802                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 803                 cifs_reconnect(server);
 804                 return -ECONNABORTED;
 805         }
 806
 807         /* switch to large buffer if too big for a small one */
 808         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
 809                 server->large_buf = true;
 810                 memcpy(server->bigbuf, buf, server->total_read);
 811                 buf = server->bigbuf;
 812         }
 813
 814         /* now read the rest */
 815         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
 816                                        pdu_length - HEADER_SIZE(server) + 1
 817                                        + server->vals->header_preamble_size);
 818
 819         if (length < 0)
 820                 return length;
 821         server->total_read += length;
 822
 823         dump_smb(buf, server->total_read);
 824
 825         return cifs_handle_standard(server, mid);
 826 }
 827
 828 int
 829 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 830 {
 831         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
 832         int length;
 833
 834         /*
 835          * We know that we received enough to get to the MID as we
 836          * checked the pdu_length earlier. Now check to see
 837          * if the rest of the header is OK. We borrow the length
 838          * var for the rest of the loop to avoid a new stack var.
 839          *
 840          * 48 bytes is enough to display the header and a little bit
 841          * into the payload for debugging purposes.
 842          */
 843         length = server->ops->check_message(buf, server->total_read, server);
 844         if (length != 0)
 845                 cifs_dump_mem("Bad SMB: ", buf,
 846                         min_t(unsigned int, server->total_read, 48));
 847
 848         if (server->ops->is_session_expired &&
 849             server->ops->is_session_expired(buf)) {
 850                 cifs_reconnect(server);
 851                 return -1;
 852         }
 853
 854         if (server->ops->is_status_pending &&
 855             server->ops->is_status_pending(buf, server))
 856                 return -1;
 857
 858         if (!mid)
 859                 return length;
 860
 861         handle_mid(mid, server, buf, length);
 862         return 0;
 863 }
 864
 865 static void
 866 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 867 {
 868         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 869         int scredits, in_flight;
 870
 871         /*
 872          * SMB1 does not use credits.
 873          */
 874         if (server->vals->header_preamble_size)
 875                 return;
 876
 877         if (shdr->CreditRequest) {
 878                 spin_lock(&server->req_lock);
 879                 server->credits += le16_to_cpu(shdr->CreditRequest);
 880                 scredits = server->credits;
 881                 in_flight = server->in_flight;
 882                 spin_unlock(&server->req_lock);
 883                 wake_up(&server->request_q);
 884
 885                 trace_smb3_add_credits(server->CurrentMid,
 886                                 server->conn_id, server->hostname, scredits,
 887                                 le16_to_cpu(shdr->CreditRequest), in_flight);
 888                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
 889                                 __func__, le16_to_cpu(shdr->CreditRequest),
 890                                 scredits);
 891         }
 892 }
 893
 894
 895 static int
 896 cifs_demultiplex_thread(void *p)
 897 {
 898         int i, num_mids, length;
 899         struct TCP_Server_Info *server = p;
 900         unsigned int pdu_length;
 901         unsigned int next_offset;
 902         char *buf = NULL;
 903         struct task_struct *task_to_wake = NULL;
 904         struct mid_q_entry *mids[MAX_COMPOUND];
 905         char *bufs[MAX_COMPOUND];
 906         unsigned int noreclaim_flag, num_io_timeout = 0;
 907
 908         noreclaim_flag = memalloc_noreclaim_save();
 909         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
 910
 911         length = atomic_inc_return(&tcpSesAllocCount);
 912         if (length > 1)
 913                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 914
 915         set_freezable();
 916         allow_kernel_signal(SIGKILL);
 917         while (server->tcpStatus != CifsExiting) {
 918                 if (try_to_freeze())
 919                         continue;
 920
 921                 if (!allocate_buffers(server))
 922                         continue;
 923
 924                 server->large_buf = false;
 925                 buf = server->smallbuf;
 926                 pdu_length = 4; /* enough to get RFC1001 header */
 927
 928                 length = cifs_read_from_socket(server, buf, pdu_length);
 929                 if (length < 0)
 930                         continue;
 931
 932                 if (server->vals->header_preamble_size == 0)
 933                         server->total_read = 0;
 934                 else
 935                         server->total_read = length;
 936
 937                 /*
 938                  * The right amount was read from socket - 4 bytes,
 939                  * so we can now interpret the length field.
 940                  */
 941                 pdu_length = get_rfc1002_length(buf);
 942
 943                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
 944                 if (!is_smb_response(server, buf[0]))
 945                         continue;
 946 next_pdu:
 947                 server->pdu_size = pdu_length;
 948
 949                 /* make sure we have enough to get to the MID */
 950                 if (server->pdu_size < HEADER_SIZE(server) - 1 -
 951                     server->vals->header_preamble_size) {
 952                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
 953                                  server->pdu_size);
 954                         cifs_reconnect(server);
 955                         continue;
 956                 }
 957
 958                 /* read down to the MID */
 959                 length = cifs_read_from_socket(server,
 960                              buf + server->vals->header_preamble_size,
 961                              HEADER_SIZE(server) - 1
 962                              - server->vals->header_preamble_size);
 963                 if (length < 0)
 964                         continue;
 965                 server->total_read += length;
 966
 967                 if (server->ops->next_header) {
 968                         next_offset = server->ops->next_header(buf);
 969                         if (next_offset)
 970                                 server->pdu_size = next_offset;
 971                 }
 972
 973                 memset(mids, 0, sizeof(mids));
 974                 memset(bufs, 0, sizeof(bufs));
 975                 num_mids = 0;
 976
 977                 if (server->ops->is_transform_hdr &&
 978                     server->ops->receive_transform &&
 979                     server->ops->is_transform_hdr(buf)) {
 980                         length = server->ops->receive_transform(server,
 981                                                                 mids,
 982                                                                 bufs,
 983                                                                 &num_mids);
 984                 } else {
 985                         mids[0] = server->ops->find_mid(server, buf);
 986                         bufs[0] = buf;
 987                         num_mids = 1;
 988
 989                         if (!mids[0] || !mids[0]->receive)
 990                                 length = standard_receive3(server, mids[0]);
 991                         else
 992                                 length = mids[0]->receive(server, mids[0]);
 993                 }
 994
 995                 if (length < 0) {
 996                         for (i = 0; i < num_mids; i++)
 997                                 if (mids[i])
 998                                         cifs_mid_q_entry_release(mids[i]);
 999                         continue;
1000                 }
1001
1002                 if (server->ops->is_status_io_timeout &&
1003                     server->ops->is_status_io_timeout(buf)) {
1004                         num_io_timeout++;
1005                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1006                                 cifs_reconnect(server);
1007                                 num_io_timeout = 0;
1008                                 continue;
1009                         }
1010                 }
1011
1012                 server->lstrp = jiffies;
1013
1014                 for (i = 0; i < num_mids; i++) {
1015                         if (mids[i] != NULL) {
1016                                 mids[i]->resp_buf_size = server->pdu_size;
1017
1018                                 if (bufs[i] && server->ops->is_network_name_deleted)
1019                                         server->ops->is_network_name_deleted(bufs[i],
1020                                                                         server);
1021
1022                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1023                                         mids[i]->callback(mids[i]);
1024
1025                                 cifs_mid_q_entry_release(mids[i]);
1026                         } else if (server->ops->is_oplock_break &&
1027                                    server->ops->is_oplock_break(bufs[i],
1028                                                                 server)) {
1029                                 smb2_add_credits_from_hdr(bufs[i], server);
1030                                 cifs_dbg(FYI, "Received oplock break\n");
1031                         } else {
1032                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1033                                                 atomic_read(&midCount));
1034                                 cifs_dump_mem("Received Data is: ", bufs[i],
1035                                               HEADER_SIZE(server));
1036                                 smb2_add_credits_from_hdr(bufs[i], server);
1037 #ifdef CONFIG_CIFS_DEBUG2
1038                                 if (server->ops->dump_detail)
1039                                         server->ops->dump_detail(bufs[i],
1040                                                                  server);
1041                                 cifs_dump_mids(server);
1042 #endif /* CIFS_DEBUG2 */
1043                         }
1044                 }
1045
1046                 if (pdu_length > server->pdu_size) {
1047                         if (!allocate_buffers(server))
1048                                 continue;
1049                         pdu_length -= server->pdu_size;
1050                         server->total_read = 0;
1051                         server->large_buf = false;
1052                         buf = server->smallbuf;
1053                         goto next_pdu;
1054                 }
1055         } /* end while !EXITING */
1056
1057         /* buffer usually freed in free_mid - need to free it here on exit */
1058         cifs_buf_release(server->bigbuf);
1059         if (server->smallbuf) /* no sense logging a debug message if NULL */
1060                 cifs_small_buf_release(server->smallbuf);
1061
1062         task_to_wake = xchg(&server->tsk, NULL);
1063         clean_demultiplex_info(server);
1064
1065         /* if server->tsk was NULL then wait for a signal before exiting */
1066         if (!task_to_wake) {
1067                 set_current_state(TASK_INTERRUPTIBLE);
1068                 while (!signal_pending(current)) {
1069                         schedule();
1070                         set_current_state(TASK_INTERRUPTIBLE);
1071                 }
1072                 set_current_state(TASK_RUNNING);
1073         }
1074
1075         memalloc_noreclaim_restore(noreclaim_flag);
1076         module_put_and_exit(0);
1077 }
1078
1079 /**
1080  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1081  * if srcaddr is specified and matches the IP address of the rhs argument
1082  */
1083 bool
1084 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1085 {
1086         switch (srcaddr->sa_family) {
1087         case AF_UNSPEC:
1088                 return (rhs->sa_family == AF_UNSPEC);
1089         case AF_INET: {
1090                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1091                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1092                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1093         }
1094         case AF_INET6: {
1095                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1096                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1097                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1098         }
1099         default:
1100                 WARN_ON(1);
1101                 return false; /* don't expect to be here */
1102         }
1103 }
1104
1105 /*
1106  * If no port is specified in addr structure, we try to match with 445 port
1107  * and if it fails - with 139 ports. It should be called only if address
1108  * families of server and addr are equal.
1109  */
1110 static bool
1111 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1112 {
1113         __be16 port, *sport;
1114
1115         /* SMBDirect manages its own ports, don't match it here */
1116         if (server->rdma)
1117                 return true;
1118
1119         switch (addr->sa_family) {
1120         case AF_INET:
1121                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1122                 port = ((struct sockaddr_in *) addr)->sin_port;
1123                 break;
1124         case AF_INET6:
1125                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1126                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1127                 break;
1128         default:
1129                 WARN_ON(1);
1130                 return false;
1131         }
1132
1133         if (!port) {
1134                 port = htons(CIFS_PORT);
1135                 if (port == *sport)
1136                         return true;
1137
1138                 port = htons(RFC1001_PORT);
1139         }
1140
1141         return port == *sport;
1142 }
1143
1144 static bool
1145 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1146               struct sockaddr *srcaddr)
1147 {
1148         switch (addr->sa_family) {
1149         case AF_INET: {
1150                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1151                 struct sockaddr_in *srv_addr4 =
1152                                         (struct sockaddr_in *)&server->dstaddr;
1153
1154                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1155                         return false;
1156                 break;
1157         }
1158         case AF_INET6: {
1159                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1160                 struct sockaddr_in6 *srv_addr6 =
1161                                         (struct sockaddr_in6 *)&server->dstaddr;
1162
1163                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1164                                      &srv_addr6->sin6_addr))
1165                         return false;
1166                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1167                         return false;
1168                 break;
1169         }
1170         default:
1171                 WARN_ON(1);
1172                 return false; /* don't expect to be here */
1173         }
1174
1175         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1176                 return false;
1177
1178         return true;
1179 }
1180
1181 static bool
1182 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1183 {
1184         /*
1185          * The select_sectype function should either return the ctx->sectype
1186          * that was specified, or "Unspecified" if that sectype was not
1187          * compatible with the given NEGOTIATE request.
1188          */
1189         if (server->ops->select_sectype(server, ctx->sectype)
1190              == Unspecified)
1191                 return false;
1192
1193         /*
1194          * Now check if signing mode is acceptable. No need to check
1195          * global_secflags at this point since if MUST_SIGN is set then
1196          * the server->sign had better be too.
1197          */
1198         if (ctx->sign && !server->sign)
1199                 return false;
1200
1201         return true;
1202 }
1203
1204 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1205 {
1206         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1207
1208         if (ctx->nosharesock)
1209                 return 0;
1210
1211         /* If multidialect negotiation see if existing sessions match one */
1212         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1213                 if (server->vals->protocol_id < SMB30_PROT_ID)
1214                         return 0;
1215         } else if (strcmp(ctx->vals->version_string,
1216                    SMBDEFAULT_VERSION_STRING) == 0) {
1217                 if (server->vals->protocol_id < SMB21_PROT_ID)
1218                         return 0;
1219         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1220                 return 0;
1221
1222         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1223                 return 0;
1224
1225         if (!match_address(server, addr,
1226                            (struct sockaddr *)&ctx->srcaddr))
1227                 return 0;
1228
1229         if (!match_port(server, addr))
1230                 return 0;
1231
1232         if (!match_security(server, ctx))
1233                 return 0;
1234
1235         if (server->echo_interval != ctx->echo_interval * HZ)
1236                 return 0;
1237
1238         if (server->rdma != ctx->rdma)
1239                 return 0;
1240
1241         if (server->ignore_signature != ctx->ignore_signature)
1242                 return 0;
1243
1244         if (server->min_offload != ctx->min_offload)
1245                 return 0;
1246
1247         return 1;
1248 }
1249
1250 struct TCP_Server_Info *
1251 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1252 {
1253         struct TCP_Server_Info *server;
1254
1255         spin_lock(&cifs_tcp_ses_lock);
1256         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1257                 /*
1258                  * Skip ses channels since they're only handled in lower layers
1259                  * (e.g. cifs_send_recv).
1260                  */
1261                 if (server->is_channel || !match_server(server, ctx))
1262                         continue;
1263
1264                 ++server->srv_count;
1265                 spin_unlock(&cifs_tcp_ses_lock);
1266                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1267                 return server;
1268         }
1269         spin_unlock(&cifs_tcp_ses_lock);
1270         return NULL;
1271 }
1272
1273 void
1274 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1275 {
1276         struct task_struct *task;
1277
1278         spin_lock(&cifs_tcp_ses_lock);
1279         if (--server->srv_count > 0) {
1280                 spin_unlock(&cifs_tcp_ses_lock);
1281                 return;
1282         }
1283
1284         put_net(cifs_net_ns(server));
1285
1286         list_del_init(&server->tcp_ses_list);
1287         spin_unlock(&cifs_tcp_ses_lock);
1288
1289         cancel_delayed_work_sync(&server->echo);
1290
1291         if (from_reconnect)
1292                 /*
1293                  * Avoid deadlock here: reconnect work calls
1294                  * cifs_put_tcp_session() at its end. Need to be sure
1295                  * that reconnect work does nothing with server pointer after
1296                  * that step.
1297                  */
1298                 cancel_delayed_work(&server->reconnect);
1299         else
1300                 cancel_delayed_work_sync(&server->reconnect);
1301
1302         spin_lock(&GlobalMid_Lock);
1303         server->tcpStatus = CifsExiting;
1304         spin_unlock(&GlobalMid_Lock);
1305
1306         cifs_crypto_secmech_release(server);
1307         cifs_fscache_release_client_cookie(server);
1308
1309         kfree(server->session_key.response);
1310         server->session_key.response = NULL;
1311         server->session_key.len = 0;
1312
1313         task = xchg(&server->tsk, NULL);
1314         if (task)
1315                 send_sig(SIGKILL, task, 1);
1316 }
1317
1318 struct TCP_Server_Info *
1319 cifs_get_tcp_session(struct smb3_fs_context *ctx)
1320 {
1321         struct TCP_Server_Info *tcp_ses = NULL;
1322         int rc;
1323
1324         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1325
1326         /* see if we already have a matching tcp_ses */
1327         tcp_ses = cifs_find_tcp_session(ctx);
1328         if (tcp_ses)
1329                 return tcp_ses;
1330
1331         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1332         if (!tcp_ses) {
1333                 rc = -ENOMEM;
1334                 goto out_err;
1335         }
1336
1337         tcp_ses->ops = ctx->ops;
1338         tcp_ses->vals = ctx->vals;
1339         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1340         tcp_ses->hostname = extract_hostname(ctx->UNC);
1341         if (IS_ERR(tcp_ses->hostname)) {
1342                 rc = PTR_ERR(tcp_ses->hostname);
1343                 goto out_err_crypto_release;
1344         }
1345
1346         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1347         tcp_ses->noblockcnt = ctx->rootfs;
1348         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1349         tcp_ses->noautotune = ctx->noautotune;
1350         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1351         tcp_ses->rdma = ctx->rdma;
1352         tcp_ses->in_flight = 0;
1353         tcp_ses->max_in_flight = 0;
1354         tcp_ses->credits = 1;
1355         init_waitqueue_head(&tcp_ses->response_q);
1356         init_waitqueue_head(&tcp_ses->request_q);
1357         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1358         mutex_init(&tcp_ses->srv_mutex);
1359         memcpy(tcp_ses->workstation_RFC1001_name,
1360                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1361         memcpy(tcp_ses->server_RFC1001_name,
1362                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1363         tcp_ses->session_estab = false;
1364         tcp_ses->sequence_number = 0;
1365         tcp_ses->reconnect_instance = 1;
1366         tcp_ses->lstrp = jiffies;
1367         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1368         spin_lock_init(&tcp_ses->req_lock);
1369         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1370         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1371         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1372         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1373         mutex_init(&tcp_ses->reconnect_mutex);
1374         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1375                sizeof(tcp_ses->srcaddr));
1376         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1377                 sizeof(tcp_ses->dstaddr));
1378         if (ctx->use_client_guid)
1379                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1380                        SMB2_CLIENT_GUID_SIZE);
1381         else
1382                 generate_random_uuid(tcp_ses->client_guid);
1383         /*
1384          * at this point we are the only ones with the pointer
1385          * to the struct since the kernel thread not created yet
1386          * no need to spinlock this init of tcpStatus or srv_count
1387          */
1388         tcp_ses->tcpStatus = CifsNew;
1389         ++tcp_ses->srv_count;
1390
1391         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1392                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1393                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1394         else
1395                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1396         if (tcp_ses->rdma) {
1397 #ifndef CONFIG_CIFS_SMB_DIRECT
1398                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1399                 rc = -ENOENT;
1400                 goto out_err_crypto_release;
1401 #endif
1402                 tcp_ses->smbd_conn = smbd_get_connection(
1403                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1404                 if (tcp_ses->smbd_conn) {
1405                         cifs_dbg(VFS, "RDMA transport established\n");
1406                         rc = 0;
1407                         goto smbd_connected;
1408                 } else {
1409                         rc = -ENOENT;
1410                         goto out_err_crypto_release;
1411                 }
1412         }
1413         rc = ip_connect(tcp_ses);
1414         if (rc < 0) {
1415                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1416                 goto out_err_crypto_release;
1417         }
1418 smbd_connected:
1419         /*
1420          * since we're in a cifs function already, we know that
1421          * this will succeed. No need for try_module_get().
1422          */
1423         __module_get(THIS_MODULE);
1424         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1425                                   tcp_ses, "cifsd");
1426         if (IS_ERR(tcp_ses->tsk)) {
1427                 rc = PTR_ERR(tcp_ses->tsk);
1428                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1429                 module_put(THIS_MODULE);
1430                 goto out_err_crypto_release;
1431         }
1432         tcp_ses->min_offload = ctx->min_offload;
1433         tcp_ses->tcpStatus = CifsNeedNegotiate;
1434
1435         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1436                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1437         else
1438                 tcp_ses->max_credits = ctx->max_credits;
1439
1440         tcp_ses->nr_targets = 1;
1441         tcp_ses->ignore_signature = ctx->ignore_signature;
1442         /* thread spawned, put it on the list */
1443         spin_lock(&cifs_tcp_ses_lock);
1444         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1445         spin_unlock(&cifs_tcp_ses_lock);
1446
1447         cifs_fscache_get_client_cookie(tcp_ses);
1448
1449         /* queue echo request delayed work */
1450         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1451
1452         return tcp_ses;
1453
1454 out_err_crypto_release:
1455         cifs_crypto_secmech_release(tcp_ses);
1456
1457         put_net(cifs_net_ns(tcp_ses));
1458
1459 out_err:
1460         if (tcp_ses) {
1461                 if (!IS_ERR(tcp_ses->hostname))
1462                         kfree(tcp_ses->hostname);
1463                 if (tcp_ses->ssocket)
1464                         sock_release(tcp_ses->ssocket);
1465                 kfree(tcp_ses);
1466         }
1467         return ERR_PTR(rc);
1468 }
1469
1470 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1471 {
1472         if (ctx->sectype != Unspecified &&
1473             ctx->sectype != ses->sectype)
1474                 return 0;
1475
1476         /*
1477          * If an existing session is limited to less channels than
1478          * requested, it should not be reused
1479          */
1480         if (ses->chan_max < ctx->max_channels)
1481                 return 0;
1482
1483         switch (ses->sectype) {
1484         case Kerberos:
1485                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1486                         return 0;
1487                 break;
1488         default:
1489                 /* NULL username means anonymous session */
1490                 if (ses->user_name == NULL) {
1491                         if (!ctx->nullauth)
1492                                 return 0;
1493                         break;
1494                 }
1495
1496                 /* anything else takes username/password */
1497                 if (strncmp(ses->user_name,
1498                             ctx->username ? ctx->username : "",
1499                             CIFS_MAX_USERNAME_LEN))
1500                         return 0;
1501                 if ((ctx->username && strlen(ctx->username) != 0) &&
1502                     ses->password != NULL &&
1503                     strncmp(ses->password,
1504                             ctx->password ? ctx->password : "",
1505                             CIFS_MAX_PASSWORD_LEN))
1506                         return 0;
1507         }
1508         return 1;
1509 }
1510
1511 /**
1512  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1513  *
1514  * A new IPC connection is made and stored in the session
1515  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1516  */
1517 static int
1518 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1519 {
1520         int rc = 0, xid;
1521         struct cifs_tcon *tcon;
1522         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1523         bool seal = false;
1524         struct TCP_Server_Info *server = ses->server;
1525
1526         /*
1527          * If the mount request that resulted in the creation of the
1528          * session requires encryption, force IPC to be encrypted too.
1529          */
1530         if (ctx->seal) {
1531                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1532                         seal = true;
1533                 else {
1534                         cifs_server_dbg(VFS,
1535                                  "IPC: server doesn't support encryption\n");
1536                         return -EOPNOTSUPP;
1537                 }
1538         }
1539
1540         tcon = tconInfoAlloc();
1541         if (tcon == NULL)
1542                 return -ENOMEM;
1543
1544         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1545
1546         xid = get_xid();
1547         tcon->ses = ses;
1548         tcon->ipc = true;
1549         tcon->seal = seal;
1550         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1551         free_xid(xid);
1552
1553         if (rc) {
1554                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1555                 tconInfoFree(tcon);
1556                 goto out;
1557         }
1558
1559         cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid);
1560
1561         ses->tcon_ipc = tcon;
1562 out:
1563         return rc;
1564 }
1565
1566 /**
1567  * cifs_free_ipc - helper to release the session IPC tcon
1568  *
1569  * Needs to be called everytime a session is destroyed
1570  */
1571 static int
1572 cifs_free_ipc(struct cifs_ses *ses)
1573 {
1574         int rc = 0, xid;
1575         struct cifs_tcon *tcon = ses->tcon_ipc;
1576
1577         if (tcon == NULL)
1578                 return 0;
1579
1580         if (ses->server->ops->tree_disconnect) {
1581                 xid = get_xid();
1582                 rc = ses->server->ops->tree_disconnect(xid, tcon);
1583                 free_xid(xid);
1584         }
1585
1586         if (rc)
1587                 cifs_dbg(FYI, "failed to disconnect IPC tcon (rc=%d)\n", rc);
1588
1589         tconInfoFree(tcon);
1590         ses->tcon_ipc = NULL;
1591         return rc;
1592 }
1593
1594 static struct cifs_ses *
1595 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1596 {
1597         struct cifs_ses *ses;
1598
1599         spin_lock(&cifs_tcp_ses_lock);
1600         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1601                 if (ses->status == CifsExiting)
1602                         continue;
1603                 if (!match_session(ses, ctx))
1604                         continue;
1605                 ++ses->ses_count;
1606                 spin_unlock(&cifs_tcp_ses_lock);
1607                 return ses;
1608         }
1609         spin_unlock(&cifs_tcp_ses_lock);
1610         return NULL;
1611 }
1612
1613 void cifs_put_smb_ses(struct cifs_ses *ses)
1614 {
1615         unsigned int rc, xid;
1616         struct TCP_Server_Info *server = ses->server;
1617
1618         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1619
1620         spin_lock(&cifs_tcp_ses_lock);
1621         if (ses->status == CifsExiting) {
1622                 spin_unlock(&cifs_tcp_ses_lock);
1623                 return;
1624         }
1625         if (--ses->ses_count > 0) {
1626                 spin_unlock(&cifs_tcp_ses_lock);
1627                 return;
1628         }
1629         if (ses->status == CifsGood)
1630                 ses->status = CifsExiting;
1631         spin_unlock(&cifs_tcp_ses_lock);
1632
1633         cifs_free_ipc(ses);
1634
1635         if (ses->status == CifsExiting && server->ops->logoff) {
1636                 xid = get_xid();
1637                 rc = server->ops->logoff(xid, ses);
1638                 if (rc)
1639                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1640                                 __func__, rc);
1641                 _free_xid(xid);
1642         }
1643
1644         spin_lock(&cifs_tcp_ses_lock);
1645         list_del_init(&ses->smb_ses_list);
1646         spin_unlock(&cifs_tcp_ses_lock);
1647
1648         /* close any extra channels */
1649         if (ses->chan_count > 1) {
1650                 int i;
1651
1652                 for (i = 1; i < ses->chan_count; i++)
1653                         cifs_put_tcp_session(ses->chans[i].server, 0);
1654         }
1655
1656         sesInfoFree(ses);
1657         cifs_put_tcp_session(server, 0);
1658 }
1659
1660 #ifdef CONFIG_KEYS
1661
1662 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1663 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1664
1665 /* Populate username and pw fields from keyring if possible */
1666 static int
1667 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1668 {
1669         int rc = 0;
1670         int is_domain = 0;
1671         const char *delim, *payload;
1672         char *desc;
1673         ssize_t len;
1674         struct key *key;
1675         struct TCP_Server_Info *server = ses->server;
1676         struct sockaddr_in *sa;
1677         struct sockaddr_in6 *sa6;
1678         const struct user_key_payload *upayload;
1679
1680         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1681         if (!desc)
1682                 return -ENOMEM;
1683
1684         /* try to find an address key first */
1685         switch (server->dstaddr.ss_family) {
1686         case AF_INET:
1687                 sa = (struct sockaddr_in *)&server->dstaddr;
1688                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1689                 break;
1690         case AF_INET6:
1691                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1692                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1693                 break;
1694         default:
1695                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1696                          server->dstaddr.ss_family);
1697                 rc = -EINVAL;
1698                 goto out_err;
1699         }
1700
1701         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1702         key = request_key(&key_type_logon, desc, "");
1703         if (IS_ERR(key)) {
1704                 if (!ses->domainName) {
1705                         cifs_dbg(FYI, "domainName is NULL\n");
1706                         rc = PTR_ERR(key);
1707                         goto out_err;
1708                 }
1709
1710                 /* didn't work, try to find a domain key */
1711                 sprintf(desc, "cifs:d:%s", ses->domainName);
1712                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1713                 key = request_key(&key_type_logon, desc, "");
1714                 if (IS_ERR(key)) {
1715                         rc = PTR_ERR(key);
1716                         goto out_err;
1717                 }
1718                 is_domain = 1;
1719         }
1720
1721         down_read(&key->sem);
1722         upayload = user_key_payload_locked(key);
1723         if (IS_ERR_OR_NULL(upayload)) {
1724                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1725                 goto out_key_put;
1726         }
1727
1728         /* find first : in payload */
1729         payload = upayload->data;
1730         delim = strnchr(payload, upayload->datalen, ':');
1731         cifs_dbg(FYI, "payload=%s\n", payload);
1732         if (!delim) {
1733                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1734                          upayload->datalen);
1735                 rc = -EINVAL;
1736                 goto out_key_put;
1737         }
1738
1739         len = delim - payload;
1740         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1741                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1742                          len);
1743                 rc = -EINVAL;
1744                 goto out_key_put;
1745         }
1746
1747         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1748         if (!ctx->username) {
1749                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1750                          len);
1751                 rc = -ENOMEM;
1752                 goto out_key_put;
1753         }
1754         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
1755
1756         len = key->datalen - (len + 1);
1757         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
1758                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
1759                 rc = -EINVAL;
1760                 kfree(ctx->username);
1761                 ctx->username = NULL;
1762                 goto out_key_put;
1763         }
1764
1765         ++delim;
1766         ctx->password = kstrndup(delim, len, GFP_KERNEL);
1767         if (!ctx->password) {
1768                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
1769                          len);
1770                 rc = -ENOMEM;
1771                 kfree(ctx->username);
1772                 ctx->username = NULL;
1773                 goto out_key_put;
1774         }
1775
1776         /*
1777          * If we have a domain key then we must set the domainName in the
1778          * for the request.
1779          */
1780         if (is_domain && ses->domainName) {
1781                 ctx->domainname = kstrndup(ses->domainName,
1782                                            strlen(ses->domainName),
1783                                            GFP_KERNEL);
1784                 if (!ctx->domainname) {
1785                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
1786                                  len);
1787                         rc = -ENOMEM;
1788                         kfree(ctx->username);
1789                         ctx->username = NULL;
1790                         kfree_sensitive(ctx->password);
1791                         ctx->password = NULL;
1792                         goto out_key_put;
1793                 }
1794         }
1795
1796 out_key_put:
1797         up_read(&key->sem);
1798         key_put(key);
1799 out_err:
1800         kfree(desc);
1801         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
1802         return rc;
1803 }
1804 #else /* ! CONFIG_KEYS */
1805 static inline int
1806 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
1807                    struct cifs_ses *ses __attribute__((unused)))
1808 {
1809         return -ENOSYS;
1810 }
1811 #endif /* CONFIG_KEYS */
1812
1813 /**
1814  * cifs_get_smb_ses - get a session matching @ctx data from @server
1815  *
1816  * This function assumes it is being called from cifs_mount() where we
1817  * already got a server reference (server refcount +1). See
1818  * cifs_get_tcon() for refcount explanations.
1819  */
1820 struct cifs_ses *
1821 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1822 {
1823         int rc = -ENOMEM;
1824         unsigned int xid;
1825         struct cifs_ses *ses;
1826         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
1827         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
1828
1829         xid = get_xid();
1830
1831         ses = cifs_find_smb_ses(server, ctx);
1832         if (ses) {
1833                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
1834                          ses->status);
1835
1836                 mutex_lock(&ses->session_mutex);
1837                 rc = cifs_negotiate_protocol(xid, ses);
1838                 if (rc) {
1839                         mutex_unlock(&ses->session_mutex);
1840                         /* problem -- put our ses reference */
1841                         cifs_put_smb_ses(ses);
1842                         free_xid(xid);
1843                         return ERR_PTR(rc);
1844                 }
1845                 if (ses->need_reconnect) {
1846                         cifs_dbg(FYI, "Session needs reconnect\n");
1847                         rc = cifs_setup_session(xid, ses,
1848                                                 ctx->local_nls);
1849                         if (rc) {
1850                                 mutex_unlock(&ses->session_mutex);
1851                                 /* problem -- put our reference */
1852                                 cifs_put_smb_ses(ses);
1853                                 free_xid(xid);
1854                                 return ERR_PTR(rc);
1855                         }
1856                 }
1857                 mutex_unlock(&ses->session_mutex);
1858
1859                 /* existing SMB ses has a server reference already */
1860                 cifs_put_tcp_session(server, 0);
1861                 free_xid(xid);
1862                 return ses;
1863         }
1864
1865         cifs_dbg(FYI, "Existing smb sess not found\n");
1866         ses = sesInfoAlloc();
1867         if (ses == NULL)
1868                 goto get_ses_fail;
1869
1870         /* new SMB session uses our server ref */
1871         ses->server = server;
1872         if (server->dstaddr.ss_family == AF_INET6)
1873                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
1874         else
1875                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
1876
1877         if (ctx->username) {
1878                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
1879                 if (!ses->user_name)
1880                         goto get_ses_fail;
1881         }
1882
1883         /* ctx->password freed at unmount */
1884         if (ctx->password) {
1885                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
1886                 if (!ses->password)
1887                         goto get_ses_fail;
1888         }
1889         if (ctx->domainname) {
1890                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
1891                 if (!ses->domainName)
1892                         goto get_ses_fail;
1893         }
1894         if (ctx->domainauto)
1895                 ses->domainAuto = ctx->domainauto;
1896         ses->cred_uid = ctx->cred_uid;
1897         ses->linux_uid = ctx->linux_uid;
1898
1899         ses->sectype = ctx->sectype;
1900         ses->sign = ctx->sign;
1901         mutex_lock(&ses->session_mutex);
1902
1903         /* add server as first channel */
1904         ses->chans[0].server = server;
1905         ses->chan_count = 1;
1906         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
1907
1908         rc = cifs_negotiate_protocol(xid, ses);
1909         if (!rc)
1910                 rc = cifs_setup_session(xid, ses, ctx->local_nls);
1911
1912         /* each channel uses a different signing key */
1913         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
1914                sizeof(ses->smb3signingkey));
1915
1916         mutex_unlock(&ses->session_mutex);
1917         if (rc)
1918                 goto get_ses_fail;
1919
1920         /* success, put it on the list and add it as first channel */
1921         spin_lock(&cifs_tcp_ses_lock);
1922         list_add(&ses->smb_ses_list, &server->smb_ses_list);
1923         spin_unlock(&cifs_tcp_ses_lock);
1924
1925         free_xid(xid);
1926
1927         cifs_setup_ipc(ses, ctx);
1928
1929         return ses;
1930
1931 get_ses_fail:
1932         sesInfoFree(ses);
1933         free_xid(xid);
1934         return ERR_PTR(rc);
1935 }
1936
1937 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
1938 {
1939         if (tcon->tidStatus == CifsExiting)
1940                 return 0;
1941         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
1942                 return 0;
1943         if (tcon->seal != ctx->seal)
1944                 return 0;
1945         if (tcon->snapshot_time != ctx->snapshot_time)
1946                 return 0;
1947         if (tcon->handle_timeout != ctx->handle_timeout)
1948                 return 0;
1949         if (tcon->no_lease != ctx->no_lease)
1950                 return 0;
1951         if (tcon->nodelete != ctx->nodelete)
1952                 return 0;
1953         return 1;
1954 }
1955
1956 static struct cifs_tcon *
1957 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1958 {
1959         struct list_head *tmp;
1960         struct cifs_tcon *tcon;
1961
1962         spin_lock(&cifs_tcp_ses_lock);
1963         list_for_each(tmp, &ses->tcon_list) {
1964                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
1965 #ifdef CONFIG_CIFS_DFS_UPCALL
1966                 if (tcon->dfs_path)
1967                         continue;
1968 #endif
1969                 if (!match_tcon(tcon, ctx))
1970                         continue;
1971                 ++tcon->tc_count;
1972                 spin_unlock(&cifs_tcp_ses_lock);
1973                 return tcon;
1974         }
1975         spin_unlock(&cifs_tcp_ses_lock);
1976         return NULL;
1977 }
1978
1979 void
1980 cifs_put_tcon(struct cifs_tcon *tcon)
1981 {
1982         unsigned int xid;
1983         struct cifs_ses *ses;
1984
1985         /*
1986          * IPC tcon share the lifetime of their session and are
1987          * destroyed in the session put function
1988          */
1989         if (tcon == NULL || tcon->ipc)
1990                 return;
1991
1992         ses = tcon->ses;
1993         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
1994         spin_lock(&cifs_tcp_ses_lock);
1995         if (--tcon->tc_count > 0) {
1996                 spin_unlock(&cifs_tcp_ses_lock);
1997                 return;
1998         }
1999
2000         if (tcon->use_witness) {
2001                 int rc;
2002
2003                 rc = cifs_swn_unregister(tcon);
2004                 if (rc < 0) {
2005                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2006                                         __func__, rc);
2007                 }
2008         }
2009
2010         list_del_init(&tcon->tcon_list);
2011         spin_unlock(&cifs_tcp_ses_lock);
2012
2013         xid = get_xid();
2014         if (ses->server->ops->tree_disconnect)
2015                 ses->server->ops->tree_disconnect(xid, tcon);
2016         _free_xid(xid);
2017
2018         cifs_fscache_release_super_cookie(tcon);
2019         tconInfoFree(tcon);
2020         cifs_put_smb_ses(ses);
2021 }
2022
2023 /**
2024  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2025  *
2026  * - tcon refcount is the number of mount points using the tcon.
2027  * - ses refcount is the number of tcon using the session.
2028  *
2029  * 1. This function assumes it is being called from cifs_mount() where
2030  *    we already got a session reference (ses refcount +1).
2031  *
2032  * 2. Since we're in the context of adding a mount point, the end
2033  *    result should be either:
2034  *
2035  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2036  *    its session refcount incremented (1 new tcon). This +1 was
2037  *    already done in (1).
2038  *
2039  * b) an existing tcon with refcount+1 (add a mount point to it) and
2040  *    identical ses refcount (no new tcon). Because of (1) we need to
2041  *    decrement the ses refcount.
2042  */
2043 static struct cifs_tcon *
2044 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2045 {
2046         int rc, xid;
2047         struct cifs_tcon *tcon;
2048
2049         tcon = cifs_find_tcon(ses, ctx);
2050         if (tcon) {
2051                 /*
2052                  * tcon has refcount already incremented but we need to
2053                  * decrement extra ses reference gotten by caller (case b)
2054                  */
2055                 cifs_dbg(FYI, "Found match on UNC path\n");
2056                 cifs_put_smb_ses(ses);
2057                 return tcon;
2058         }
2059
2060         if (!ses->server->ops->tree_connect) {
2061                 rc = -ENOSYS;
2062                 goto out_fail;
2063         }
2064
2065         tcon = tconInfoAlloc();
2066         if (tcon == NULL) {
2067                 rc = -ENOMEM;
2068                 goto out_fail;
2069         }
2070
2071         if (ctx->snapshot_time) {
2072                 if (ses->server->vals->protocol_id == 0) {
2073                         cifs_dbg(VFS,
2074                              "Use SMB2 or later for snapshot mount option\n");
2075                         rc = -EOPNOTSUPP;
2076                         goto out_fail;
2077                 } else
2078                         tcon->snapshot_time = ctx->snapshot_time;
2079         }
2080
2081         if (ctx->handle_timeout) {
2082                 if (ses->server->vals->protocol_id == 0) {
2083                         cifs_dbg(VFS,
2084                              "Use SMB2.1 or later for handle timeout option\n");
2085                         rc = -EOPNOTSUPP;
2086                         goto out_fail;
2087                 } else
2088                         tcon->handle_timeout = ctx->handle_timeout;
2089         }
2090
2091         tcon->ses = ses;
2092         if (ctx->password) {
2093                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2094                 if (!tcon->password) {
2095                         rc = -ENOMEM;
2096                         goto out_fail;
2097                 }
2098         }
2099
2100         if (ctx->seal) {
2101                 if (ses->server->vals->protocol_id == 0) {
2102                         cifs_dbg(VFS,
2103                                  "SMB3 or later required for encryption\n");
2104                         rc = -EOPNOTSUPP;
2105                         goto out_fail;
2106                 } else if (tcon->ses->server->capabilities &
2107                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2108                         tcon->seal = true;
2109                 else {
2110                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2111                         rc = -EOPNOTSUPP;
2112                         goto out_fail;
2113                 }
2114         }
2115
2116         if (ctx->linux_ext) {
2117                 if (ses->server->posix_ext_supported) {
2118                         tcon->posix_extensions = true;
2119                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2120                 } else {
2121                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2122                         rc = -EOPNOTSUPP;
2123                         goto out_fail;
2124                 }
2125         }
2126
2127         /*
2128          * BB Do we need to wrap session_mutex around this TCon call and Unix
2129          * SetFS as we do on SessSetup and reconnect?
2130          */
2131         xid = get_xid();
2132         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2133                                             ctx->local_nls);
2134         free_xid(xid);
2135         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2136         if (rc)
2137                 goto out_fail;
2138
2139         tcon->use_persistent = false;
2140         /* check if SMB2 or later, CIFS does not support persistent handles */
2141         if (ctx->persistent) {
2142                 if (ses->server->vals->protocol_id == 0) {
2143                         cifs_dbg(VFS,
2144                              "SMB3 or later required for persistent handles\n");
2145                         rc = -EOPNOTSUPP;
2146                         goto out_fail;
2147                 } else if (ses->server->capabilities &
2148                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2149                         tcon->use_persistent = true;
2150                 else /* persistent handles requested but not supported */ {
2151                         cifs_dbg(VFS,
2152                                 "Persistent handles not supported on share\n");
2153                         rc = -EOPNOTSUPP;
2154                         goto out_fail;
2155                 }
2156         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2157              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2158              && (ctx->nopersistent == false)) {
2159                 cifs_dbg(FYI, "enabling persistent handles\n");
2160                 tcon->use_persistent = true;
2161         } else if (ctx->resilient) {
2162                 if (ses->server->vals->protocol_id == 0) {
2163                         cifs_dbg(VFS,
2164                              "SMB2.1 or later required for resilient handles\n");
2165                         rc = -EOPNOTSUPP;
2166                         goto out_fail;
2167                 }
2168                 tcon->use_resilient = true;
2169         }
2170
2171         tcon->use_witness = false;
2172         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2173                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2174                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2175                                 /*
2176                                  * Set witness in use flag in first place
2177                                  * to retry registration in the echo task
2178                                  */
2179                                 tcon->use_witness = true;
2180                                 /* And try to register immediately */
2181                                 rc = cifs_swn_register(tcon);
2182                                 if (rc < 0) {
2183                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2184                                         goto out_fail;
2185                                 }
2186                         } else {
2187                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2188                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2189                                 rc = -EOPNOTSUPP;
2190                                 goto out_fail;
2191                         }
2192                 } else {
2193                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2194                         rc = -EOPNOTSUPP;
2195                         goto out_fail;
2196                 }
2197         }
2198
2199         /* If the user really knows what they are doing they can override */
2200         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2201                 if (ctx->cache_ro)
2202                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2203                 else if (ctx->cache_rw)
2204                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2205         }
2206
2207         if (ctx->no_lease) {
2208                 if (ses->server->vals->protocol_id == 0) {
2209                         cifs_dbg(VFS,
2210                                 "SMB2 or later required for nolease option\n");
2211                         rc = -EOPNOTSUPP;
2212                         goto out_fail;
2213                 } else
2214                         tcon->no_lease = ctx->no_lease;
2215         }
2216
2217         /*
2218          * We can have only one retry value for a connection to a share so for
2219          * resources mounted more than once to the same server share the last
2220          * value passed in for the retry flag is used.
2221          */
2222         tcon->retry = ctx->retry;
2223         tcon->nocase = ctx->nocase;
2224         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2225                 tcon->nohandlecache = ctx->nohandlecache;
2226         else
2227                 tcon->nohandlecache = true;
2228         tcon->nodelete = ctx->nodelete;
2229         tcon->local_lease = ctx->local_lease;
2230         INIT_LIST_HEAD(&tcon->pending_opens);
2231
2232         spin_lock(&cifs_tcp_ses_lock);
2233         list_add(&tcon->tcon_list, &ses->tcon_list);
2234         spin_unlock(&cifs_tcp_ses_lock);
2235
2236         cifs_fscache_get_super_cookie(tcon);
2237
2238         return tcon;
2239
2240 out_fail:
2241         tconInfoFree(tcon);
2242         return ERR_PTR(rc);
2243 }
2244
2245 void
2246 cifs_put_tlink(struct tcon_link *tlink)
2247 {
2248         if (!tlink || IS_ERR(tlink))
2249                 return;
2250
2251         if (!atomic_dec_and_test(&tlink->tl_count) ||
2252             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2253                 tlink->tl_time = jiffies;
2254                 return;
2255         }
2256
2257         if (!IS_ERR(tlink_tcon(tlink)))
2258                 cifs_put_tcon(tlink_tcon(tlink));
2259         kfree(tlink);
2260         return;
2261 }
2262
2263 static int
2264 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2265 {
2266         struct cifs_sb_info *old = CIFS_SB(sb);
2267         struct cifs_sb_info *new = mnt_data->cifs_sb;
2268         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2269         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2270
2271         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2272                 return 0;
2273
2274         if (old->mnt_cifs_serverino_autodisabled)
2275                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2276
2277         if (oldflags != newflags)
2278                 return 0;
2279
2280         /*
2281          * We want to share sb only if we don't specify an r/wsize or
2282          * specified r/wsize is greater than or equal to existing one.
2283          */
2284         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2285                 return 0;
2286
2287         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2288                 return 0;
2289
2290         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2291             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2292                 return 0;
2293
2294         if (old->ctx->file_mode != new->ctx->file_mode ||
2295             old->ctx->dir_mode != new->ctx->dir_mode)
2296                 return 0;
2297
2298         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2299                 return 0;
2300
2301         if (old->ctx->acregmax != new->ctx->acregmax)
2302                 return 0;
2303         if (old->ctx->acdirmax != new->ctx->acdirmax)
2304                 return 0;
2305
2306         return 1;
2307 }
2308
2309 static int
2310 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2311 {
2312         struct cifs_sb_info *old = CIFS_SB(sb);
2313         struct cifs_sb_info *new = mnt_data->cifs_sb;
2314         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2315                 old->prepath;
2316         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2317                 new->prepath;
2318
2319         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2320                 return 1;
2321         else if (!old_set && !new_set)
2322                 return 1;
2323
2324         return 0;
2325 }
2326
2327 int
2328 cifs_match_super(struct super_block *sb, void *data)
2329 {
2330         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2331         struct smb3_fs_context *ctx;
2332         struct cifs_sb_info *cifs_sb;
2333         struct TCP_Server_Info *tcp_srv;
2334         struct cifs_ses *ses;
2335         struct cifs_tcon *tcon;
2336         struct tcon_link *tlink;
2337         int rc = 0;
2338
2339         spin_lock(&cifs_tcp_ses_lock);
2340         cifs_sb = CIFS_SB(sb);
2341         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2342         if (IS_ERR(tlink)) {
2343                 spin_unlock(&cifs_tcp_ses_lock);
2344                 return rc;
2345         }
2346         tcon = tlink_tcon(tlink);
2347         ses = tcon->ses;
2348         tcp_srv = ses->server;
2349
2350         ctx = mnt_data->ctx;
2351
2352         if (!match_server(tcp_srv, ctx) ||
2353             !match_session(ses, ctx) ||
2354             !match_tcon(tcon, ctx) ||
2355             !match_prepath(sb, mnt_data)) {
2356                 rc = 0;
2357                 goto out;
2358         }
2359
2360         rc = compare_mount_options(sb, mnt_data);
2361 out:
2362         spin_unlock(&cifs_tcp_ses_lock);
2363         cifs_put_tlink(tlink);
2364         return rc;
2365 }
2366
2367 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2368 static struct lock_class_key cifs_key[2];
2369 static struct lock_class_key cifs_slock_key[2];
2370
2371 static inline void
2372 cifs_reclassify_socket4(struct socket *sock)
2373 {
2374         struct sock *sk = sock->sk;
2375         BUG_ON(!sock_allow_reclassification(sk));
2376         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2377                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2378 }
2379
2380 static inline void
2381 cifs_reclassify_socket6(struct socket *sock)
2382 {
2383         struct sock *sk = sock->sk;
2384         BUG_ON(!sock_allow_reclassification(sk));
2385         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2386                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2387 }
2388 #else
2389 static inline void
2390 cifs_reclassify_socket4(struct socket *sock)
2391 {
2392 }
2393
2394 static inline void
2395 cifs_reclassify_socket6(struct socket *sock)
2396 {
2397 }
2398 #endif
2399
2400 /* See RFC1001 section 14 on representation of Netbios names */
2401 static void rfc1002mangle(char *target, char *source, unsigned int length)
2402 {
2403         unsigned int i, j;
2404
2405         for (i = 0, j = 0; i < (length); i++) {
2406                 /* mask a nibble at a time and encode */
2407                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2408                 target[j+1] = 'A' + (0x0F & source[i]);
2409                 j += 2;
2410         }
2411
2412 }
2413
2414 static int
2415 bind_socket(struct TCP_Server_Info *server)
2416 {
2417         int rc = 0;
2418         if (server->srcaddr.ss_family != AF_UNSPEC) {
2419                 /* Bind to the specified local IP address */
2420                 struct socket *socket = server->ssocket;
2421                 rc = socket->ops->bind(socket,
2422                                        (struct sockaddr *) &server->srcaddr,
2423                                        sizeof(server->srcaddr));
2424                 if (rc < 0) {
2425                         struct sockaddr_in *saddr4;
2426                         struct sockaddr_in6 *saddr6;
2427                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2428                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2429                         if (saddr6->sin6_family == AF_INET6)
2430                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2431                                          &saddr6->sin6_addr, rc);
2432                         else
2433                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2434                                          &saddr4->sin_addr.s_addr, rc);
2435                 }
2436         }
2437         return rc;
2438 }
2439
2440 static int
2441 ip_rfc1001_connect(struct TCP_Server_Info *server)
2442 {
2443         int rc = 0;
2444         /*
2445          * some servers require RFC1001 sessinit before sending
2446          * negprot - BB check reconnection in case where second
2447          * sessinit is sent but no second negprot
2448          */
2449         struct rfc1002_session_packet *ses_init_buf;
2450         struct smb_hdr *smb_buf;
2451         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2452                                GFP_KERNEL);
2453         if (ses_init_buf) {
2454                 ses_init_buf->trailer.session_req.called_len = 32;
2455
2456                 if (server->server_RFC1001_name[0] != 0)
2457                         rfc1002mangle(ses_init_buf->trailer.
2458                                       session_req.called_name,
2459                                       server->server_RFC1001_name,
2460                                       RFC1001_NAME_LEN_WITH_NULL);
2461                 else
2462                         rfc1002mangle(ses_init_buf->trailer.
2463                                       session_req.called_name,
2464                                       DEFAULT_CIFS_CALLED_NAME,
2465                                       RFC1001_NAME_LEN_WITH_NULL);
2466
2467                 ses_init_buf->trailer.session_req.calling_len = 32;
2468
2469                 /*
2470                  * calling name ends in null (byte 16) from old smb
2471                  * convention.
2472                  */
2473                 if (server->workstation_RFC1001_name[0] != 0)
2474                         rfc1002mangle(ses_init_buf->trailer.
2475                                       session_req.calling_name,
2476                                       server->workstation_RFC1001_name,
2477                                       RFC1001_NAME_LEN_WITH_NULL);
2478                 else
2479                         rfc1002mangle(ses_init_buf->trailer.
2480                                       session_req.calling_name,
2481                                       "LINUX_CIFS_CLNT",
2482                                       RFC1001_NAME_LEN_WITH_NULL);
2483
2484                 ses_init_buf->trailer.session_req.scope1 = 0;
2485                 ses_init_buf->trailer.session_req.scope2 = 0;
2486                 smb_buf = (struct smb_hdr *)ses_init_buf;
2487
2488                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2489                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2490                 rc = smb_send(server, smb_buf, 0x44);
2491                 kfree(ses_init_buf);
2492                 /*
2493                  * RFC1001 layer in at least one server
2494                  * requires very short break before negprot
2495                  * presumably because not expecting negprot
2496                  * to follow so fast.  This is a simple
2497                  * solution that works without
2498                  * complicating the code and causes no
2499                  * significant slowing down on mount
2500                  * for everyone else
2501                  */
2502                 usleep_range(1000, 2000);
2503         }
2504         /*
2505          * else the negprot may still work without this
2506          * even though malloc failed
2507          */
2508
2509         return rc;
2510 }
2511
2512 static int
2513 generic_ip_connect(struct TCP_Server_Info *server)
2514 {
2515         int rc = 0;
2516         __be16 sport;
2517         int slen, sfamily;
2518         struct socket *socket = server->ssocket;
2519         struct sockaddr *saddr;
2520
2521         saddr = (struct sockaddr *) &server->dstaddr;
2522
2523         if (server->dstaddr.ss_family == AF_INET6) {
2524                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2525
2526                 sport = ipv6->sin6_port;
2527                 slen = sizeof(struct sockaddr_in6);
2528                 sfamily = AF_INET6;
2529                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2530                                 ntohs(sport));
2531         } else {
2532                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2533
2534                 sport = ipv4->sin_port;
2535                 slen = sizeof(struct sockaddr_in);
2536                 sfamily = AF_INET;
2537                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2538                                 ntohs(sport));
2539         }
2540
2541         if (socket == NULL) {
2542                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2543                                    IPPROTO_TCP, &socket, 1);
2544                 if (rc < 0) {
2545                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2546                         server->ssocket = NULL;
2547                         return rc;
2548                 }
2549
2550                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2551                 cifs_dbg(FYI, "Socket created\n");
2552                 server->ssocket = socket;
2553                 socket->sk->sk_allocation = GFP_NOFS;
2554                 if (sfamily == AF_INET6)
2555                         cifs_reclassify_socket6(socket);
2556                 else
2557                         cifs_reclassify_socket4(socket);
2558         }
2559
2560         rc = bind_socket(server);
2561         if (rc < 0)
2562                 return rc;
2563
2564         /*
2565          * Eventually check for other socket options to change from
2566          * the default. sock_setsockopt not used because it expects
2567          * user space buffer
2568          */
2569         socket->sk->sk_rcvtimeo = 7 * HZ;
2570         socket->sk->sk_sndtimeo = 5 * HZ;
2571
2572         /* make the bufsizes depend on wsize/rsize and max requests */
2573         if (server->noautotune) {
2574                 if (socket->sk->sk_sndbuf < (200 * 1024))
2575                         socket->sk->sk_sndbuf = 200 * 1024;
2576                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2577                         socket->sk->sk_rcvbuf = 140 * 1024;
2578         }
2579
2580         if (server->tcp_nodelay)
2581                 tcp_sock_set_nodelay(socket->sk);
2582
2583         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2584                  socket->sk->sk_sndbuf,
2585                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2586
2587         rc = socket->ops->connect(socket, saddr, slen,
2588                                   server->noblockcnt ? O_NONBLOCK : 0);
2589         /*
2590          * When mounting SMB root file systems, we do not want to block in
2591          * connect. Otherwise bail out and then let cifs_reconnect() perform
2592          * reconnect failover - if possible.
2593          */
2594         if (server->noblockcnt && rc == -EINPROGRESS)
2595                 rc = 0;
2596         if (rc < 0) {
2597                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2598                 sock_release(socket);
2599                 server->ssocket = NULL;
2600                 return rc;
2601         }
2602
2603         if (sport == htons(RFC1001_PORT))
2604                 rc = ip_rfc1001_connect(server);
2605
2606         return rc;
2607 }
2608
2609 static int
2610 ip_connect(struct TCP_Server_Info *server)
2611 {
2612         __be16 *sport;
2613         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2614         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2615
2616         if (server->dstaddr.ss_family == AF_INET6)
2617                 sport = &addr6->sin6_port;
2618         else
2619                 sport = &addr->sin_port;
2620
2621         if (*sport == 0) {
2622                 int rc;
2623
2624                 /* try with 445 port at first */
2625                 *sport = htons(CIFS_PORT);
2626
2627                 rc = generic_ip_connect(server);
2628                 if (rc >= 0)
2629                         return rc;
2630
2631                 /* if it failed, try with 139 port */
2632                 *sport = htons(RFC1001_PORT);
2633         }
2634
2635         return generic_ip_connect(server);
2636 }
2637
2638 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2639                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2640 {
2641         /*
2642          * If we are reconnecting then should we check to see if
2643          * any requested capabilities changed locally e.g. via
2644          * remount but we can not do much about it here
2645          * if they have (even if we could detect it by the following)
2646          * Perhaps we could add a backpointer to array of sb from tcon
2647          * or if we change to make all sb to same share the same
2648          * sb as NFS - then we only have one backpointer to sb.
2649          * What if we wanted to mount the server share twice once with
2650          * and once without posixacls or posix paths?
2651          */
2652         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2653
2654         if (ctx && ctx->no_linux_ext) {
2655                 tcon->fsUnixInfo.Capability = 0;
2656                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2657                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2658                 return;
2659         } else if (ctx)
2660                 tcon->unix_ext = 1; /* Unix Extensions supported */
2661
2662         if (!tcon->unix_ext) {
2663                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2664                 return;
2665         }
2666
2667         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2668                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2669                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2670                 /*
2671                  * check for reconnect case in which we do not
2672                  * want to change the mount behavior if we can avoid it
2673                  */
2674                 if (ctx == NULL) {
2675                         /*
2676                          * turn off POSIX ACL and PATHNAMES if not set
2677                          * originally at mount time
2678                          */
2679                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2680                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2681                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2682                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2683                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2684                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2685                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2686                                 cifs_dbg(VFS, "possible reconnect error\n");
2687                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2688                         }
2689                 }
2690
2691                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2692                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2693
2694                 cap &= CIFS_UNIX_CAP_MASK;
2695                 if (ctx && ctx->no_psx_acl)
2696                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2697                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2698                         cifs_dbg(FYI, "negotiated posix acl support\n");
2699                         if (cifs_sb)
2700                                 cifs_sb->mnt_cifs_flags |=
2701                                         CIFS_MOUNT_POSIXACL;
2702                 }
2703
2704                 if (ctx && ctx->posix_paths == 0)
2705                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2706                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2707                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2708                         if (cifs_sb)
2709                                 cifs_sb->mnt_cifs_flags |=
2710                                         CIFS_MOUNT_POSIX_PATHS;
2711                 }
2712
2713                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
2714 #ifdef CONFIG_CIFS_DEBUG2
2715                 if (cap & CIFS_UNIX_FCNTL_CAP)
2716                         cifs_dbg(FYI, "FCNTL cap\n");
2717                 if (cap & CIFS_UNIX_EXTATTR_CAP)
2718                         cifs_dbg(FYI, "EXTATTR cap\n");
2719                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2720                         cifs_dbg(FYI, "POSIX path cap\n");
2721                 if (cap & CIFS_UNIX_XATTR_CAP)
2722                         cifs_dbg(FYI, "XATTR cap\n");
2723                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
2724                         cifs_dbg(FYI, "POSIX ACL cap\n");
2725                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
2726                         cifs_dbg(FYI, "very large read cap\n");
2727                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
2728                         cifs_dbg(FYI, "very large write cap\n");
2729                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
2730                         cifs_dbg(FYI, "transport encryption cap\n");
2731                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2732                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
2733 #endif /* CIFS_DEBUG2 */
2734                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
2735                         if (ctx == NULL)
2736                                 cifs_dbg(FYI, "resetting capabilities failed\n");
2737                         else
2738                                 cifs_dbg(VFS, "Negotiating Unix capabilities with the server failed. Consider mounting with the Unix Extensions disabled if problems are found by specifying the nounix mount option.\n");
2739
2740                 }
2741         }
2742 }
2743
2744 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
2745 {
2746         struct smb3_fs_context *ctx = cifs_sb->ctx;
2747
2748         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
2749
2750         spin_lock_init(&cifs_sb->tlink_tree_lock);
2751         cifs_sb->tlink_tree = RB_ROOT;
2752
2753         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
2754                  ctx->file_mode, ctx->dir_mode);
2755
2756         /* this is needed for ASCII cp to Unicode converts */
2757         if (ctx->iocharset == NULL) {
2758                 /* load_nls_default cannot return null */
2759                 cifs_sb->local_nls = load_nls_default();
2760         } else {
2761                 cifs_sb->local_nls = load_nls(ctx->iocharset);
2762                 if (cifs_sb->local_nls == NULL) {
2763                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
2764                                  ctx->iocharset);
2765                         return -ELIBACC;
2766                 }
2767         }
2768         ctx->local_nls = cifs_sb->local_nls;
2769
2770         smb3_update_mnt_flags(cifs_sb);
2771
2772         if (ctx->direct_io)
2773                 cifs_dbg(FYI, "mounting share using direct i/o\n");
2774         if (ctx->cache_ro) {
2775                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
2776                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
2777         } else if (ctx->cache_rw) {
2778                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
2779                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
2780                                             CIFS_MOUNT_RW_CACHE);
2781         }
2782
2783         if ((ctx->cifs_acl) && (ctx->dynperm))
2784                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
2785
2786         if (ctx->prepath) {
2787                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
2788                 if (cifs_sb->prepath == NULL)
2789                         return -ENOMEM;
2790                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
2791         }
2792
2793         return 0;
2794 }
2795
2796 /* Release all succeed connections */
2797 static inline void mount_put_conns(struct cifs_sb_info *cifs_sb,
2798                                    unsigned int xid,
2799                                    struct TCP_Server_Info *server,
2800                                    struct cifs_ses *ses, struct cifs_tcon *tcon)
2801 {
2802         int rc = 0;
2803
2804         if (tcon)
2805                 cifs_put_tcon(tcon);
2806         else if (ses)
2807                 cifs_put_smb_ses(ses);
2808         else if (server)
2809                 cifs_put_tcp_session(server, 0);
2810         cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
2811         free_xid(xid);
2812 }
2813
2814 /* Get connections for tcp, ses and tcon */
2815 static int mount_get_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
2816                            unsigned int *xid,
2817                            struct TCP_Server_Info **nserver,
2818                            struct cifs_ses **nses, struct cifs_tcon **ntcon)
2819 {
2820         int rc = 0;
2821         struct TCP_Server_Info *server;
2822         struct cifs_ses *ses;
2823         struct cifs_tcon *tcon;
2824
2825         *nserver = NULL;
2826         *nses = NULL;
2827         *ntcon = NULL;
2828
2829         *xid = get_xid();
2830
2831         /* get a reference to a tcp session */
2832         server = cifs_get_tcp_session(ctx);
2833         if (IS_ERR(server)) {
2834                 rc = PTR_ERR(server);
2835                 return rc;
2836         }
2837
2838         *nserver = server;
2839
2840         /* get a reference to a SMB session */
2841         ses = cifs_get_smb_ses(server, ctx);
2842         if (IS_ERR(ses)) {
2843                 rc = PTR_ERR(ses);
2844                 return rc;
2845         }
2846
2847         *nses = ses;
2848
2849         if ((ctx->persistent == true) && (!(ses->server->capabilities &
2850                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
2851                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
2852                 return -EOPNOTSUPP;
2853         }
2854
2855         /* search for existing tcon to this server share */
2856         tcon = cifs_get_tcon(ses, ctx);
2857         if (IS_ERR(tcon)) {
2858                 rc = PTR_ERR(tcon);
2859                 return rc;
2860         }
2861
2862         *ntcon = tcon;
2863
2864         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
2865         if (tcon->posix_extensions)
2866                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
2867
2868         /* tell server which Unix caps we support */
2869         if (cap_unix(tcon->ses)) {
2870                 /*
2871                  * reset of caps checks mount to see if unix extensions disabled
2872                  * for just this mount.
2873                  */
2874                 reset_cifs_unix_caps(*xid, tcon, cifs_sb, ctx);
2875                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
2876                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
2877                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP))
2878                         return -EACCES;
2879         } else
2880                 tcon->unix_ext = 0; /* server does not support them */
2881
2882         /* do not care if a following call succeed - informational */
2883         if (!tcon->pipe && server->ops->qfs_tcon) {
2884                 server->ops->qfs_tcon(*xid, tcon, cifs_sb);
2885                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
2886                         if (tcon->fsDevInfo.DeviceCharacteristics &
2887                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
2888                                 cifs_dbg(VFS, "mounted to read only share\n");
2889                         else if ((cifs_sb->mnt_cifs_flags &
2890                                   CIFS_MOUNT_RW_CACHE) == 0)
2891                                 cifs_dbg(VFS, "read only mount of RW share\n");
2892                         /* no need to log a RW mount of a typical RW share */
2893                 }
2894         }
2895
2896         /*
2897          * Clamp the rsize/wsize mount arguments if they are too big for the server
2898          * and set the rsize/wsize to the negotiated values if not passed in by
2899          * the user on mount
2900          */
2901         if ((cifs_sb->ctx->wsize == 0) ||
2902             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
2903                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
2904         if ((cifs_sb->ctx->rsize == 0) ||
2905             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
2906                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
2907
2908         return 0;
2909 }
2910
2911 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
2912                              struct cifs_tcon *tcon)
2913 {
2914         struct tcon_link *tlink;
2915
2916         /* hang the tcon off of the superblock */
2917         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
2918         if (tlink == NULL)
2919                 return -ENOMEM;
2920
2921         tlink->tl_uid = ses->linux_uid;
2922         tlink->tl_tcon = tcon;
2923         tlink->tl_time = jiffies;
2924         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
2925         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
2926
2927         cifs_sb->master_tlink = tlink;
2928         spin_lock(&cifs_sb->tlink_tree_lock);
2929         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
2930         spin_unlock(&cifs_sb->tlink_tree_lock);
2931
2932         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
2933                                 TLINK_IDLE_EXPIRE);
2934         return 0;
2935 }
2936
2937 #ifdef CONFIG_CIFS_DFS_UPCALL
2938 /*
2939  * cifs_build_path_to_root returns full path to root when we do not have an
2940  * existing connection (tcon)
2941  */
2942 static char *
2943 build_unc_path_to_root(const struct smb3_fs_context *ctx,
2944                        const struct cifs_sb_info *cifs_sb, bool useppath)
2945 {
2946         char *full_path, *pos;
2947         unsigned int pplen = useppath && ctx->prepath ?
2948                 strlen(ctx->prepath) + 1 : 0;
2949         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
2950
2951         if (unc_len > MAX_TREE_SIZE)
2952                 return ERR_PTR(-EINVAL);
2953
2954         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
2955         if (full_path == NULL)
2956                 return ERR_PTR(-ENOMEM);
2957
2958         memcpy(full_path, ctx->UNC, unc_len);
2959         pos = full_path + unc_len;
2960
2961         if (pplen) {
2962                 *pos = CIFS_DIR_SEP(cifs_sb);
2963                 memcpy(pos + 1, ctx->prepath, pplen);
2964                 pos += pplen;
2965         }
2966
2967         *pos = '\0'; /* add trailing null */
2968         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
2969         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
2970         return full_path;
2971 }
2972
2973 /**
2974  * expand_dfs_referral - Perform a dfs referral query and update the cifs_sb
2975  *
2976  * If a referral is found, cifs_sb->ctx->mount_options will be (re-)allocated
2977  * to a string containing updated options for the submount.  Otherwise it
2978  * will be left untouched.
2979  *
2980  * Returns the rc from get_dfs_path to the caller, which can be used to
2981  * determine whether there were referrals.
2982  */
2983 static int
2984 expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
2985                     struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
2986                     char *ref_path)
2987 {
2988         int rc;
2989         struct dfs_info3_param referral = {0};
2990         char *full_path = NULL, *mdata = NULL;
2991
2992         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
2993                 return -EREMOTE;
2994
2995         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
2996         if (IS_ERR(full_path))
2997                 return PTR_ERR(full_path);
2998
2999         rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3000                             ref_path, &referral, NULL);
3001         if (!rc) {
3002                 char *fake_devname = NULL;
3003
3004                 mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options,
3005                                                    full_path + 1, &referral,
3006                                                    &fake_devname);
3007                 free_dfs_info_param(&referral);
3008
3009                 if (IS_ERR(mdata)) {
3010                         rc = PTR_ERR(mdata);
3011                         mdata = NULL;
3012                 } else {
3013                         /*
3014                          * We can not clear out the whole structure since we
3015                          * no longer have an explicit function to parse
3016                          * a mount-string. Instead we need to clear out the
3017                          * individual fields that are no longer valid.
3018                          */
3019                         kfree(ctx->prepath);
3020                         ctx->prepath = NULL;
3021                         rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3022                 }
3023                 kfree(fake_devname);
3024                 kfree(cifs_sb->ctx->mount_options);
3025                 cifs_sb->ctx->mount_options = mdata;
3026         }
3027         kfree(full_path);
3028         return rc;
3029 }
3030
3031 static inline int get_next_dfs_tgt(const char *path,
3032                                    struct dfs_cache_tgt_list *tgt_list,
3033                                    struct dfs_cache_tgt_iterator **tgt_it)
3034 {
3035         if (!*tgt_it)
3036                 *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
3037         else
3038                 *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it);
3039         return !*tgt_it ? -EHOSTDOWN : 0;
3040 }
3041
3042 static int update_vol_info(const struct dfs_cache_tgt_iterator *tgt_it,
3043                            struct smb3_fs_context *fake_ctx, struct smb3_fs_context *ctx)
3044 {
3045         const char *tgt = dfs_cache_get_tgt_name(tgt_it);
3046         int len = strlen(tgt) + 2;
3047         char *new_unc;
3048
3049         new_unc = kmalloc(len, GFP_KERNEL);
3050         if (!new_unc)
3051                 return -ENOMEM;
3052         scnprintf(new_unc, len, "\\%s", tgt);
3053
3054         kfree(ctx->UNC);
3055         ctx->UNC = new_unc;
3056
3057         if (fake_ctx->prepath) {
3058                 kfree(ctx->prepath);
3059                 ctx->prepath = fake_ctx->prepath;
3060                 fake_ctx->prepath = NULL;
3061         }
3062         memcpy(&ctx->dstaddr, &fake_ctx->dstaddr, sizeof(ctx->dstaddr));
3063
3064         return 0;
3065 }
3066
3067 static int do_dfs_failover(const char *path, const char *full_path, struct cifs_sb_info *cifs_sb,
3068                            struct smb3_fs_context *ctx, struct cifs_ses *root_ses,
3069                            unsigned int *xid, struct TCP_Server_Info **server,
3070                            struct cifs_ses **ses, struct cifs_tcon **tcon)
3071 {
3072         int rc;
3073         struct dfs_cache_tgt_list tgt_list = {0};
3074         struct dfs_cache_tgt_iterator *tgt_it = NULL;
3075         struct smb3_fs_context tmp_ctx = {NULL};
3076
3077         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
3078                 return -EOPNOTSUPP;
3079
3080         cifs_dbg(FYI, "%s: path=%s full_path=%s\n", __func__, path, full_path);
3081
3082         rc = dfs_cache_noreq_find(path, NULL, &tgt_list);
3083         if (rc)
3084                 return rc;
3085         /*
3086          * We use a 'tmp_ctx' here because we need pass it down to the mount_{get,put} functions to
3087          * test connection against new DFS targets.
3088          */
3089         rc = smb3_fs_context_dup(&tmp_ctx, ctx);
3090         if (rc)
3091                 goto out;
3092
3093         for (;;) {
3094                 struct dfs_info3_param ref = {0};
3095                 char *fake_devname = NULL, *mdata = NULL;
3096
3097                 /* Get next DFS target server - if any */
3098                 rc = get_next_dfs_tgt(path, &tgt_list, &tgt_it);
3099                 if (rc)
3100                         break;
3101
3102                 rc = dfs_cache_get_tgt_referral(path, tgt_it, &ref);
3103                 if (rc)
3104                         break;
3105
3106                 cifs_dbg(FYI, "%s: old ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3107                          tmp_ctx.prepath);
3108
3109                 mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, &ref,
3110                                                    &fake_devname);
3111                 free_dfs_info_param(&ref);
3112
3113                 if (IS_ERR(mdata)) {
3114                         rc = PTR_ERR(mdata);
3115                         mdata = NULL;
3116                 } else
3117                         rc = cifs_setup_volume_info(&tmp_ctx, mdata, fake_devname);
3118
3119                 kfree(mdata);
3120                 kfree(fake_devname);
3121
3122                 if (rc)
3123                         break;
3124
3125                 cifs_dbg(FYI, "%s: new ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3126                          tmp_ctx.prepath);
3127
3128                 mount_put_conns(cifs_sb, *xid, *server, *ses, *tcon);
3129                 rc = mount_get_conns(&tmp_ctx, cifs_sb, xid, server, ses, tcon);
3130                 if (!rc || (*server && *ses)) {
3131                         /*
3132                          * We were able to connect to new target server. Update current context with
3133                          * new target server.
3134                          */
3135                         rc = update_vol_info(tgt_it, &tmp_ctx, ctx);
3136                         break;
3137                 }
3138         }
3139         if (!rc) {
3140                 cifs_dbg(FYI, "%s: final ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3141                          tmp_ctx.prepath);
3142                 /*
3143                  * Update DFS target hint in DFS referral cache with the target server we
3144                  * successfully reconnected to.
3145                  */
3146                 rc = dfs_cache_update_tgthint(*xid, root_ses ? root_ses : *ses, cifs_sb->local_nls,
3147                                               cifs_remap(cifs_sb), path, tgt_it);
3148         }
3149
3150 out:
3151         smb3_cleanup_fs_context_contents(&tmp_ctx);
3152         dfs_cache_free_tgts(&tgt_list);
3153         return rc;
3154 }
3155 #endif
3156
3157 /* TODO: all callers to this are broken. We are not parsing mount_options here
3158  * we should pass a clone of the original context?
3159  */
3160 int
3161 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3162 {
3163         int rc = 0;
3164
3165         smb3_parse_devname(devname, ctx);
3166
3167         if (mntopts) {
3168                 char *ip;
3169
3170                 cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
3171                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3172                 if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
3173                                                  strlen(ip))) {
3174                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3175                         return -EINVAL;
3176                 }
3177         }
3178
3179         if (ctx->nullauth) {
3180                 cifs_dbg(FYI, "Anonymous login\n");
3181                 kfree(ctx->username);
3182                 ctx->username = NULL;
3183         } else if (ctx->username) {
3184                 /* BB fixme parse for domain name here */
3185                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3186         } else {
3187                 cifs_dbg(VFS, "No username specified\n");
3188         /* In userspace mount helper we can get user name from alternate
3189            locations such as env variables and files on disk */
3190                 return -EINVAL;
3191         }
3192
3193         return rc;
3194 }
3195
3196 static int
3197 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3198                                         unsigned int xid,
3199                                         struct cifs_tcon *tcon,
3200                                         struct cifs_sb_info *cifs_sb,
3201                                         char *full_path,
3202                                         int added_treename)
3203 {
3204         int rc;
3205         char *s;
3206         char sep, tmp;
3207         int skip = added_treename ? 1 : 0;
3208
3209         sep = CIFS_DIR_SEP(cifs_sb);
3210         s = full_path;
3211
3212         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3213         while (rc == 0) {
3214                 /* skip separators */
3215                 while (*s == sep)
3216                         s++;
3217                 if (!*s)
3218                         break;
3219                 /* next separator */
3220                 while (*s && *s != sep)
3221                         s++;
3222                 /*
3223                  * if the treename is added, we then have to skip the first
3224                  * part within the separators
3225                  */
3226                 if (skip) {
3227                         skip = 0;
3228                         continue;
3229                 }
3230                 /*
3231                  * temporarily null-terminate the path at the end of
3232                  * the current component
3233                  */
3234                 tmp = *s;
3235                 *s = 0;
3236                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3237                                                      full_path);
3238                 *s = tmp;
3239         }
3240         return rc;
3241 }
3242
3243 /*
3244  * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
3245  * otherwise 0.
3246  */
3247 static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx,
3248                           const unsigned int xid,
3249                           struct TCP_Server_Info *server,
3250                           struct cifs_tcon *tcon)
3251 {
3252         int rc;
3253         char *full_path;
3254
3255         if (!server->ops->is_path_accessible)
3256                 return -EOPNOTSUPP;
3257
3258         /*
3259          * cifs_build_path_to_root works only when we have a valid tcon
3260          */
3261         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3262                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3263         if (full_path == NULL)
3264                 return -ENOMEM;
3265
3266         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3267
3268         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3269                                              full_path);
3270         if (rc != 0 && rc != -EREMOTE) {
3271                 kfree(full_path);
3272                 return rc;
3273         }
3274
3275         if (rc != -EREMOTE) {
3276                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3277                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3278                 if (rc != 0) {
3279                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3280                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3281                         rc = 0;
3282                 }
3283         }
3284
3285         kfree(full_path);
3286         return rc;
3287 }
3288
3289 #ifdef CONFIG_CIFS_DFS_UPCALL
3290 static void set_root_ses(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3291                          struct cifs_ses **root_ses)
3292 {
3293         if (ses) {
3294                 spin_lock(&cifs_tcp_ses_lock);
3295                 ses->ses_count++;
3296                 if (ses->tcon_ipc)
3297                         ses->tcon_ipc->remap = cifs_remap(cifs_sb);
3298                 spin_unlock(&cifs_tcp_ses_lock);
3299         }
3300         *root_ses = ses;
3301 }
3302
3303 static void put_root_ses(struct cifs_ses *ses)
3304 {
3305         if (ses)
3306                 cifs_put_smb_ses(ses);
3307 }
3308
3309 /* Set up next dfs prefix path in @dfs_path */
3310 static int next_dfs_prepath(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx,
3311                             const unsigned int xid, struct TCP_Server_Info *server,
3312                             struct cifs_tcon *tcon, char **dfs_path)
3313 {
3314         char *path, *npath;
3315         int added_treename = is_tcon_dfs(tcon);
3316         int rc;
3317
3318         path = cifs_build_path_to_root(ctx, cifs_sb, tcon, added_treename);
3319         if (!path)
3320                 return -ENOMEM;
3321
3322         rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3323         if (rc == -EREMOTE) {
3324                 struct smb3_fs_context v = {NULL};
3325                 /* if @path contains a tree name, skip it in the prefix path */
3326                 if (added_treename) {
3327                         rc = smb3_parse_devname(path, &v);
3328                         if (rc)
3329                                 goto out;
3330                         npath = build_unc_path_to_root(&v, cifs_sb, true);
3331                         smb3_cleanup_fs_context_contents(&v);
3332                 } else {
3333                         v.UNC = ctx->UNC;
3334                         v.prepath = path + 1;
3335                         npath = build_unc_path_to_root(&v, cifs_sb, true);
3336                 }
3337
3338                 if (IS_ERR(npath)) {
3339                         rc = PTR_ERR(npath);
3340                         goto out;
3341                 }
3342
3343                 kfree(*dfs_path);
3344                 *dfs_path = npath;
3345                 rc = -EREMOTE;
3346         }
3347
3348 out:
3349         kfree(path);
3350         return rc;
3351 }
3352
3353 /* Check if resolved targets can handle any DFS referrals */
3354 static int is_referral_server(const char *ref_path, struct cifs_tcon *tcon, bool *ref_server)
3355 {
3356         int rc;
3357         struct dfs_info3_param ref = {0};
3358
3359         if (is_tcon_dfs(tcon)) {
3360                 *ref_server = true;
3361         } else {
3362                 cifs_dbg(FYI, "%s: ref_path=%s\n", __func__, ref_path);
3363
3364                 rc = dfs_cache_noreq_find(ref_path, &ref, NULL);
3365                 if (rc) {
3366                         cifs_dbg(VFS, "%s: dfs_cache_noreq_find: failed (rc=%d)\n", __func__, rc);
3367                         return rc;
3368                 }
3369                 cifs_dbg(FYI, "%s: ref.flags=0x%x\n", __func__, ref.flags);
3370                 /*
3371                  * Check if all targets are capable of handling DFS referrals as per
3372                  * MS-DFSC 2.2.4 RESP_GET_DFS_REFERRAL.
3373                  */
3374                 *ref_server = !!(ref.flags & DFSREF_REFERRAL_SERVER);
3375                 free_dfs_info_param(&ref);
3376         }
3377         return 0;
3378 }
3379
3380 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3381 {
3382         int rc = 0;
3383         unsigned int xid;
3384         struct TCP_Server_Info *server = NULL;
3385         struct cifs_ses *ses = NULL, *root_ses = NULL;
3386         struct cifs_tcon *tcon = NULL;
3387         int count = 0;
3388         char *ref_path = NULL, *full_path = NULL;
3389         char *oldmnt = NULL;
3390         char *mntdata = NULL;
3391         bool ref_server = false;
3392
3393         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3394         /*
3395          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3396          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3397          *
3398          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3399          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3400          */
3401         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3402             dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), ctx->UNC + 1, NULL,
3403                            NULL)) {
3404                 if (rc)
3405                         goto error;
3406                 /* Check if it is fully accessible and then mount it */
3407                 rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3408                 if (!rc)
3409                         goto out;
3410                 if (rc != -EREMOTE)
3411                         goto error;
3412         }
3413         /* Save mount options */
3414         mntdata = kstrndup(cifs_sb->ctx->mount_options,
3415                            strlen(cifs_sb->ctx->mount_options), GFP_KERNEL);
3416         if (!mntdata) {
3417                 rc = -ENOMEM;
3418                 goto error;
3419         }
3420         /* Get path of DFS root */
3421         ref_path = build_unc_path_to_root(ctx, cifs_sb, false);
3422         if (IS_ERR(ref_path)) {
3423                 rc = PTR_ERR(ref_path);
3424                 ref_path = NULL;
3425                 goto error;
3426         }
3427
3428         set_root_ses(cifs_sb, ses, &root_ses);
3429         do {
3430                 /* Save full path of last DFS path we used to resolve final target server */
3431                 kfree(full_path);
3432                 full_path = build_unc_path_to_root(ctx, cifs_sb, !!count);
3433                 if (IS_ERR(full_path)) {
3434                         rc = PTR_ERR(full_path);
3435                         full_path = NULL;
3436                         break;
3437                 }
3438                 /* Chase referral */
3439                 oldmnt = cifs_sb->ctx->mount_options;
3440                 rc = expand_dfs_referral(xid, root_ses, ctx, cifs_sb, ref_path + 1);
3441                 if (rc)
3442                         break;
3443                 /* Connect to new DFS target only if we were redirected */
3444                 if (oldmnt != cifs_sb->ctx->mount_options) {
3445                         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3446                         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3447                 }
3448                 if (rc && !server && !ses) {
3449                         /* Failed to connect. Try to connect to other targets in the referral. */
3450                         rc = do_dfs_failover(ref_path + 1, full_path, cifs_sb, ctx, root_ses, &xid,
3451                                              &server, &ses, &tcon);
3452                 }
3453                 if (rc == -EACCES || rc == -EOPNOTSUPP || !server || !ses)
3454                         break;
3455                 if (!tcon)
3456                         continue;
3457
3458                 /* Make sure that requests go through new root servers */
3459                 rc = is_referral_server(ref_path + 1, tcon, &ref_server);
3460                 if (rc)
3461                         break;
3462                 if (ref_server) {
3463                         put_root_ses(root_ses);
3464                         set_root_ses(cifs_sb, ses, &root_ses);
3465                 }
3466
3467                 /* Get next dfs path and then continue chasing them if -EREMOTE */
3468                 rc = next_dfs_prepath(cifs_sb, ctx, xid, server, tcon, &ref_path);
3469                 /* Prevent recursion on broken link referrals */
3470                 if (rc == -EREMOTE && ++count > MAX_NESTED_LINKS)
3471                         rc = -ELOOP;
3472         } while (rc == -EREMOTE);
3473
3474         if (rc)
3475                 goto error;
3476         put_root_ses(root_ses);
3477         root_ses = NULL;
3478         kfree(ref_path);
3479         ref_path = NULL;
3480         /*
3481          * Store DFS full path in both superblock and tree connect structures.
3482          *
3483          * For DFS root mounts, the prefix path (cifs_sb->prepath) is preserved during reconnect so
3484          * only the root path is set in cifs_sb->origin_fullpath and tcon->dfs_path. And for DFS
3485          * links, the prefix path is included in both and may be changed during reconnect.  See
3486          * cifs_tree_connect().
3487          */
3488         cifs_sb->origin_fullpath = kstrndup(full_path, strlen(full_path), GFP_KERNEL);
3489         if (!cifs_sb->origin_fullpath) {
3490                 rc = -ENOMEM;
3491                 goto error;
3492         }
3493         spin_lock(&cifs_tcp_ses_lock);
3494         tcon->dfs_path = full_path;
3495         full_path = NULL;
3496         tcon->remap = cifs_remap(cifs_sb);
3497         spin_unlock(&cifs_tcp_ses_lock);
3498
3499         /* Add original context for DFS cache to be used when refreshing referrals */
3500         rc = dfs_cache_add_vol(mntdata, ctx, cifs_sb->origin_fullpath);
3501         if (rc)
3502                 goto error;
3503         /*
3504          * After reconnecting to a different server, unique ids won't
3505          * match anymore, so we disable serverino. This prevents
3506          * dentry revalidation to think the dentry are stale (ESTALE).
3507          */
3508         cifs_autodisable_serverino(cifs_sb);
3509         /*
3510          * Force the use of prefix path to support failover on DFS paths that
3511          * resolve to targets that have different prefix paths.
3512          */
3513         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3514         kfree(cifs_sb->prepath);
3515         cifs_sb->prepath = ctx->prepath;
3516         ctx->prepath = NULL;
3517
3518 out:
3519         free_xid(xid);
3520         cifs_try_adding_channels(cifs_sb, ses);
3521         return mount_setup_tlink(cifs_sb, ses, tcon);
3522
3523 error:
3524         kfree(ref_path);
3525         kfree(full_path);
3526         kfree(mntdata);
3527         kfree(cifs_sb->origin_fullpath);
3528         put_root_ses(root_ses);
3529         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3530         return rc;
3531 }
3532 #else
3533 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3534 {
3535         int rc = 0;
3536         unsigned int xid;
3537         struct cifs_ses *ses;
3538         struct cifs_tcon *tcon;
3539         struct TCP_Server_Info *server;
3540
3541         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3542         if (rc)
3543                 goto error;
3544
3545         if (tcon) {
3546                 rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3547                 if (rc == -EREMOTE)
3548                         rc = -EOPNOTSUPP;
3549                 if (rc)
3550                         goto error;
3551         }
3552
3553         free_xid(xid);
3554
3555         return mount_setup_tlink(cifs_sb, ses, tcon);
3556
3557 error:
3558         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3559         return rc;
3560 }
3561 #endif
3562
3563 /*
3564  * Issue a TREE_CONNECT request.
3565  */
3566 int
3567 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3568          const char *tree, struct cifs_tcon *tcon,
3569          const struct nls_table *nls_codepage)
3570 {
3571         struct smb_hdr *smb_buffer;
3572         struct smb_hdr *smb_buffer_response;
3573         TCONX_REQ *pSMB;
3574         TCONX_RSP *pSMBr;
3575         unsigned char *bcc_ptr;
3576         int rc = 0;
3577         int length;
3578         __u16 bytes_left, count;
3579
3580         if (ses == NULL)
3581                 return -EIO;
3582
3583         smb_buffer = cifs_buf_get();
3584         if (smb_buffer == NULL)
3585                 return -ENOMEM;
3586
3587         smb_buffer_response = smb_buffer;
3588
3589         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3590                         NULL /*no tid */ , 4 /*wct */ );
3591
3592         smb_buffer->Mid = get_next_mid(ses->server);
3593         smb_buffer->Uid = ses->Suid;
3594         pSMB = (TCONX_REQ *) smb_buffer;
3595         pSMBr = (TCONX_RSP *) smb_buffer_response;
3596
3597         pSMB->AndXCommand = 0xFF;
3598         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3599         bcc_ptr = &pSMB->Password[0];
3600         if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
3601                 pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3602                 *bcc_ptr = 0; /* password is null byte */
3603                 bcc_ptr++;              /* skip password */
3604                 /* already aligned so no need to do it below */
3605         } else {
3606                 pSMB->PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);
3607                 /* BB FIXME add code to fail this if NTLMv2 or Kerberos
3608                    specified as required (when that support is added to
3609                    the vfs in the future) as only NTLM or the much
3610                    weaker LANMAN (which we do not send by default) is accepted
3611                    by Samba (not sure whether other servers allow
3612                    NTLMv2 password here) */
3613 #ifdef CONFIG_CIFS_WEAK_PW_HASH
3614                 if ((global_secflags & CIFSSEC_MAY_LANMAN) &&
3615                     (ses->sectype == LANMAN))
3616                         calc_lanman_hash(tcon->password, ses->server->cryptkey,
3617                                          ses->server->sec_mode &
3618                                             SECMODE_PW_ENCRYPT ? true : false,
3619                                          bcc_ptr);
3620                 else
3621 #endif /* CIFS_WEAK_PW_HASH */
3622                 rc = SMBNTencrypt(tcon->password, ses->server->cryptkey,
3623                                         bcc_ptr, nls_codepage);
3624                 if (rc) {
3625                         cifs_dbg(FYI, "%s Can't generate NTLM rsp. Error: %d\n",
3626                                  __func__, rc);
3627                         cifs_buf_release(smb_buffer);
3628                         return rc;
3629                 }
3630
3631                 bcc_ptr += CIFS_AUTH_RESP_SIZE;
3632                 if (ses->capabilities & CAP_UNICODE) {
3633                         /* must align unicode strings */
3634                         *bcc_ptr = 0; /* null byte password */
3635                         bcc_ptr++;
3636                 }
3637         }
3638
3639         if (ses->server->sign)
3640                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3641
3642         if (ses->capabilities & CAP_STATUS32) {
3643                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3644         }
3645         if (ses->capabilities & CAP_DFS) {
3646                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3647         }
3648         if (ses->capabilities & CAP_UNICODE) {
3649                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3650                 length =
3651                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3652                         6 /* max utf8 char length in bytes */ *
3653                         (/* server len*/ + 256 /* share len */), nls_codepage);
3654                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3655                 bcc_ptr += 2;   /* skip trailing null */
3656         } else {                /* ASCII */
3657                 strcpy(bcc_ptr, tree);
3658                 bcc_ptr += strlen(tree) + 1;
3659         }
3660         strcpy(bcc_ptr, "?????");
3661         bcc_ptr += strlen("?????");
3662         bcc_ptr += 1;
3663         count = bcc_ptr - &pSMB->Password[0];
3664         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3665         pSMB->ByteCount = cpu_to_le16(count);
3666
3667         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3668                          0);
3669
3670         /* above now done in SendReceive */
3671         if (rc == 0) {
3672                 bool is_unicode;
3673
3674                 tcon->tidStatus = CifsGood;
3675                 tcon->need_reconnect = false;
3676                 tcon->tid = smb_buffer_response->Tid;
3677                 bcc_ptr = pByteArea(smb_buffer_response);
3678                 bytes_left = get_bcc(smb_buffer_response);
3679                 length = strnlen(bcc_ptr, bytes_left - 2);
3680                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3681                         is_unicode = true;
3682                 else
3683                         is_unicode = false;
3684
3685
3686                 /* skip service field (NB: this field is always ASCII) */
3687                 if (length == 3) {
3688                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3689                             (bcc_ptr[2] == 'C')) {
3690                                 cifs_dbg(FYI, "IPC connection\n");
3691                                 tcon->ipc = true;
3692                                 tcon->pipe = true;
3693                         }
3694                 } else if (length == 2) {
3695                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3696                                 /* the most common case */
3697                                 cifs_dbg(FYI, "disk share connection\n");
3698                         }
3699                 }
3700                 bcc_ptr += length + 1;
3701                 bytes_left -= (length + 1);
3702                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3703
3704                 /* mostly informational -- no need to fail on error here */
3705                 kfree(tcon->nativeFileSystem);
3706                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3707                                                       bytes_left, is_unicode,
3708                                                       nls_codepage);
3709
3710                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3711
3712                 if ((smb_buffer_response->WordCount == 3) ||
3713                          (smb_buffer_response->WordCount == 7))
3714                         /* field is in same location */
3715                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3716                 else
3717                         tcon->Flags = 0;
3718                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3719         }
3720
3721         cifs_buf_release(smb_buffer);
3722         return rc;
3723 }
3724
3725 static void delayed_free(struct rcu_head *p)
3726 {
3727         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3728
3729         unload_nls(cifs_sb->local_nls);
3730         smb3_cleanup_fs_context(cifs_sb->ctx);
3731         kfree(cifs_sb);
3732 }
3733
3734 void
3735 cifs_umount(struct cifs_sb_info *cifs_sb)
3736 {
3737         struct rb_root *root = &cifs_sb->tlink_tree;
3738         struct rb_node *node;
3739         struct tcon_link *tlink;
3740
3741         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3742
3743         spin_lock(&cifs_sb->tlink_tree_lock);
3744         while ((node = rb_first(root))) {
3745                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3746                 cifs_get_tlink(tlink);
3747                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3748                 rb_erase(node, root);
3749
3750                 spin_unlock(&cifs_sb->tlink_tree_lock);
3751                 cifs_put_tlink(tlink);
3752                 spin_lock(&cifs_sb->tlink_tree_lock);
3753         }
3754         spin_unlock(&cifs_sb->tlink_tree_lock);
3755
3756         kfree(cifs_sb->prepath);
3757 #ifdef CONFIG_CIFS_DFS_UPCALL
3758         dfs_cache_del_vol(cifs_sb->origin_fullpath);
3759         kfree(cifs_sb->origin_fullpath);
3760 #endif
3761         call_rcu(&cifs_sb->rcu, delayed_free);
3762 }
3763
3764 int
3765 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses)
3766 {
3767         int rc = 0;
3768         struct TCP_Server_Info *server = cifs_ses_server(ses);
3769
3770         if (!server->ops->need_neg || !server->ops->negotiate)
3771                 return -ENOSYS;
3772
3773         /* only send once per connect */
3774         if (!server->ops->need_neg(server))
3775                 return 0;
3776
3777         rc = server->ops->negotiate(xid, ses);
3778         if (rc == 0) {
3779                 spin_lock(&GlobalMid_Lock);
3780                 if (server->tcpStatus == CifsNeedNegotiate)
3781                         server->tcpStatus = CifsGood;
3782                 else
3783                         rc = -EHOSTDOWN;
3784                 spin_unlock(&GlobalMid_Lock);
3785         }
3786
3787         return rc;
3788 }
3789
3790 int
3791 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3792                    struct nls_table *nls_info)
3793 {
3794         int rc = -ENOSYS;
3795         struct TCP_Server_Info *server = cifs_ses_server(ses);
3796
3797         if (!ses->binding) {
3798                 ses->capabilities = server->capabilities;
3799                 if (!linuxExtEnabled)
3800                         ses->capabilities &= (~server->vals->cap_unix);
3801
3802                 if (ses->auth_key.response) {
3803                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3804                                  ses->auth_key.response);
3805                         kfree(ses->auth_key.response);
3806                         ses->auth_key.response = NULL;
3807                         ses->auth_key.len = 0;
3808                 }
3809         }
3810
3811         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3812                  server->sec_mode, server->capabilities, server->timeAdj);
3813
3814         if (server->ops->sess_setup)
3815                 rc = server->ops->sess_setup(xid, ses, nls_info);
3816
3817         if (rc)
3818                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3819
3820         return rc;
3821 }
3822
3823 static int
3824 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3825 {
3826         ctx->sectype = ses->sectype;
3827
3828         /* krb5 is special, since we don't need username or pw */
3829         if (ctx->sectype == Kerberos)
3830                 return 0;
3831
3832         return cifs_set_cifscreds(ctx, ses);
3833 }
3834
3835 static struct cifs_tcon *
3836 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3837 {
3838         int rc;
3839         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3840         struct cifs_ses *ses;
3841         struct cifs_tcon *tcon = NULL;
3842         struct smb3_fs_context *ctx;
3843
3844         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3845         if (ctx == NULL)
3846                 return ERR_PTR(-ENOMEM);
3847
3848         ctx->local_nls = cifs_sb->local_nls;
3849         ctx->linux_uid = fsuid;
3850         ctx->cred_uid = fsuid;
3851         ctx->UNC = master_tcon->treeName;
3852         ctx->retry = master_tcon->retry;
3853         ctx->nocase = master_tcon->nocase;
3854         ctx->nohandlecache = master_tcon->nohandlecache;
3855         ctx->local_lease = master_tcon->local_lease;
3856         ctx->no_lease = master_tcon->no_lease;
3857         ctx->resilient = master_tcon->use_resilient;
3858         ctx->persistent = master_tcon->use_persistent;
3859         ctx->handle_timeout = master_tcon->handle_timeout;
3860         ctx->no_linux_ext = !master_tcon->unix_ext;
3861         ctx->linux_ext = master_tcon->posix_extensions;
3862         ctx->sectype = master_tcon->ses->sectype;
3863         ctx->sign = master_tcon->ses->sign;
3864         ctx->seal = master_tcon->seal;
3865         ctx->witness = master_tcon->use_witness;
3866
3867         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3868         if (rc) {
3869                 tcon = ERR_PTR(rc);
3870                 goto out;
3871         }
3872
3873         /* get a reference for the same TCP session */
3874         spin_lock(&cifs_tcp_ses_lock);
3875         ++master_tcon->ses->server->srv_count;
3876         spin_unlock(&cifs_tcp_ses_lock);
3877
3878         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3879         if (IS_ERR(ses)) {
3880                 tcon = (struct cifs_tcon *)ses;
3881                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3882                 goto out;
3883         }
3884
3885         tcon = cifs_get_tcon(ses, ctx);
3886         if (IS_ERR(tcon)) {
3887                 cifs_put_smb_ses(ses);
3888                 goto out;
3889         }
3890
3891         if (cap_unix(ses))
3892                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3893
3894 out:
3895         kfree(ctx->username);
3896         kfree_sensitive(ctx->password);
3897         kfree(ctx);
3898
3899         return tcon;
3900 }
3901
3902 struct cifs_tcon *
3903 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3904 {
3905         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3906 }
3907
3908 /* find and return a tlink with given uid */
3909 static struct tcon_link *
3910 tlink_rb_search(struct rb_root *root, kuid_t uid)
3911 {
3912         struct rb_node *node = root->rb_node;
3913         struct tcon_link *tlink;
3914
3915         while (node) {
3916                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3917
3918                 if (uid_gt(tlink->tl_uid, uid))
3919                         node = node->rb_left;
3920                 else if (uid_lt(tlink->tl_uid, uid))
3921                         node = node->rb_right;
3922                 else
3923                         return tlink;
3924         }
3925         return NULL;
3926 }
3927
3928 /* insert a tcon_link into the tree */
3929 static void
3930 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3931 {
3932         struct rb_node **new = &(root->rb_node), *parent = NULL;
3933         struct tcon_link *tlink;
3934
3935         while (*new) {
3936                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3937                 parent = *new;
3938
3939                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3940                         new = &((*new)->rb_left);
3941                 else
3942                         new = &((*new)->rb_right);
3943         }
3944
3945         rb_link_node(&new_tlink->tl_rbnode, parent, new);
3946         rb_insert_color(&new_tlink->tl_rbnode, root);
3947 }
3948
3949 /*
3950  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3951  * current task.
3952  *
3953  * If the superblock doesn't refer to a multiuser mount, then just return
3954  * the master tcon for the mount.
3955  *
3956  * First, search the rbtree for an existing tcon for this fsuid. If one
3957  * exists, then check to see if it's pending construction. If it is then wait
3958  * for construction to complete. Once it's no longer pending, check to see if
3959  * it failed and either return an error or retry construction, depending on
3960  * the timeout.
3961  *
3962  * If one doesn't exist then insert a new tcon_link struct into the tree and
3963  * try to construct a new one.
3964  */
3965 struct tcon_link *
3966 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3967 {
3968         int ret;
3969         kuid_t fsuid = current_fsuid();
3970         struct tcon_link *tlink, *newtlink;
3971
3972         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3973                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3974
3975         spin_lock(&cifs_sb->tlink_tree_lock);
3976         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3977         if (tlink)
3978                 cifs_get_tlink(tlink);
3979         spin_unlock(&cifs_sb->tlink_tree_lock);
3980
3981         if (tlink == NULL) {
3982                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3983                 if (newtlink == NULL)
3984                         return ERR_PTR(-ENOMEM);
3985                 newtlink->tl_uid = fsuid;
3986                 newtlink->tl_tcon = ERR_PTR(-EACCES);
3987                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
3988                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
3989                 cifs_get_tlink(newtlink);
3990
3991                 spin_lock(&cifs_sb->tlink_tree_lock);
3992                 /* was one inserted after previous search? */
3993                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3994                 if (tlink) {
3995                         cifs_get_tlink(tlink);
3996                         spin_unlock(&cifs_sb->tlink_tree_lock);
3997                         kfree(newtlink);
3998                         goto wait_for_construction;
3999                 }
4000                 tlink = newtlink;
4001                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4002                 spin_unlock(&cifs_sb->tlink_tree_lock);
4003         } else {
4004 wait_for_construction:
4005                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4006                                   TASK_INTERRUPTIBLE);
4007                 if (ret) {
4008                         cifs_put_tlink(tlink);
4009                         return ERR_PTR(-ERESTARTSYS);
4010                 }
4011
4012                 /* if it's good, return it */
4013                 if (!IS_ERR(tlink->tl_tcon))
4014                         return tlink;
4015
4016                 /* return error if we tried this already recently */
4017                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4018                         cifs_put_tlink(tlink);
4019                         return ERR_PTR(-EACCES);
4020                 }
4021
4022                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4023                         goto wait_for_construction;
4024         }
4025
4026         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4027         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4028         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4029
4030         if (IS_ERR(tlink->tl_tcon)) {
4031                 cifs_put_tlink(tlink);
4032                 return ERR_PTR(-EACCES);
4033         }
4034
4035         return tlink;
4036 }
4037
4038 /*
4039  * periodic workqueue job that scans tcon_tree for a superblock and closes
4040  * out tcons.
4041  */
4042 static void
4043 cifs_prune_tlinks(struct work_struct *work)
4044 {
4045         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4046                                                     prune_tlinks.work);
4047         struct rb_root *root = &cifs_sb->tlink_tree;
4048         struct rb_node *node;
4049         struct rb_node *tmp;
4050         struct tcon_link *tlink;
4051
4052         /*
4053          * Because we drop the spinlock in the loop in order to put the tlink
4054          * it's not guarded against removal of links from the tree. The only
4055          * places that remove entries from the tree are this function and
4056          * umounts. Because this function is non-reentrant and is canceled
4057          * before umount can proceed, this is safe.
4058          */
4059         spin_lock(&cifs_sb->tlink_tree_lock);
4060         node = rb_first(root);
4061         while (node != NULL) {
4062                 tmp = node;
4063                 node = rb_next(tmp);
4064                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4065
4066                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4067                     atomic_read(&tlink->tl_count) != 0 ||
4068                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4069                         continue;
4070
4071                 cifs_get_tlink(tlink);
4072                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4073                 rb_erase(tmp, root);
4074
4075                 spin_unlock(&cifs_sb->tlink_tree_lock);
4076                 cifs_put_tlink(tlink);
4077                 spin_lock(&cifs_sb->tlink_tree_lock);
4078         }
4079         spin_unlock(&cifs_sb->tlink_tree_lock);
4080
4081         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4082                                 TLINK_IDLE_EXPIRE);
4083 }
4084
4085 #ifdef CONFIG_CIFS_DFS_UPCALL
4086 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4087 {
4088         int rc;
4089         struct TCP_Server_Info *server = tcon->ses->server;
4090         const struct smb_version_operations *ops = server->ops;
4091         struct dfs_cache_tgt_list tl;
4092         struct dfs_cache_tgt_iterator *it = NULL;
4093         char *tree;
4094         const char *tcp_host;
4095         size_t tcp_host_len;
4096         const char *dfs_host;
4097         size_t dfs_host_len;
4098         char *share = NULL, *prefix = NULL;
4099         struct dfs_info3_param ref = {0};
4100         bool isroot;
4101
4102         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4103         if (!tree)
4104                 return -ENOMEM;
4105
4106         if (!tcon->dfs_path) {
4107                 if (tcon->ipc) {
4108                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4109                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4110                 } else {
4111                         rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4112                 }
4113                 goto out;
4114         }
4115
4116         rc = dfs_cache_noreq_find(tcon->dfs_path + 1, &ref, &tl);
4117         if (rc)
4118                 goto out;
4119         isroot = ref.server_type == DFS_TYPE_ROOT;
4120         free_dfs_info_param(&ref);
4121
4122         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4123
4124         for (it = dfs_cache_get_tgt_iterator(&tl); it; it = dfs_cache_get_next_tgt(&tl, it)) {
4125                 bool target_match;
4126
4127                 kfree(share);
4128                 kfree(prefix);
4129                 share = NULL;
4130                 prefix = NULL;
4131
4132                 rc = dfs_cache_get_tgt_share(tcon->dfs_path + 1, it, &share, &prefix);
4133                 if (rc) {
4134                         cifs_dbg(VFS, "%s: failed to parse target share %d\n",
4135                                  __func__, rc);
4136                         continue;
4137                 }
4138
4139                 extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4140
4141                 if (dfs_host_len != tcp_host_len
4142                     || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4143                         cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4144                                  dfs_host, (int)tcp_host_len, tcp_host);
4145
4146                         rc = match_target_ip(server, dfs_host, dfs_host_len, &target_match);
4147                         if (rc) {
4148                                 cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4149                                 break;
4150                         }
4151
4152                         if (!target_match) {
4153                                 cifs_dbg(FYI, "%s: skipping target\n", __func__);
4154                                 continue;
4155                         }
4156                 }
4157
4158                 if (tcon->ipc) {
4159                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", share);
4160                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4161                 } else {
4162                         scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4163                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4164                         /* Only handle prefix paths of DFS link targets */
4165                         if (!rc && !isroot) {
4166                                 rc = update_super_prepath(tcon, prefix);
4167                                 break;
4168                         }
4169                 }
4170                 if (rc == -EREMOTE)
4171                         break;
4172         }
4173
4174         kfree(share);
4175         kfree(prefix);
4176
4177         if (!rc) {
4178                 if (it)
4179                         rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1, it);
4180                 else
4181                         rc = -ENOENT;
4182         }
4183         dfs_cache_free_tgts(&tl);
4184 out:
4185         kfree(tree);
4186         return rc;
4187 }
4188 #else
4189 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4190 {
4191         const struct smb_version_operations *ops = tcon->ses->server->ops;
4192
4193         return ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4194 }
4195 #endif