fs/cifs/connect.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/net.h>
  10 #include <linux/string.h>
  11 #include <linux/sched/mm.h>
  12 #include <linux/sched/signal.h>
  13 #include <linux/list.h>
  14 #include <linux/wait.h>
  15 #include <linux/slab.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/ctype.h>
  18 #include <linux/utsname.h>
  19 #include <linux/mempool.h>
  20 #include <linux/delay.h>
  21 #include <linux/completion.h>
  22 #include <linux/kthread.h>
  23 #include <linux/pagevec.h>
  24 #include <linux/freezer.h>
  25 #include <linux/namei.h>
  26 #include <linux/uuid.h>
  27 #include <linux/uaccess.h>
  28 #include <asm/processor.h>
  29 #include <linux/inet.h>
  30 #include <linux/module.h>
  31 #include <keys/user-type.h>
  32 #include <net/ipv6.h>
  33 #include <linux/parser.h>
  34 #include <linux/bvec.h>
  35 #include "cifspdu.h"
  36 #include "cifsglob.h"
  37 #include "cifsproto.h"
  38 #include "cifs_unicode.h"
  39 #include "cifs_debug.h"
  40 #include "cifs_fs_sb.h"
  41 #include "ntlmssp.h"
  42 #include "nterr.h"
  43 #include "rfc1002pdu.h"
  44 #include "fscache.h"
  45 #include "smb2proto.h"
  46 #include "smbdirect.h"
  47 #include "dns_resolve.h"
  48 #ifdef CONFIG_CIFS_DFS_UPCALL
  49 #include "dfs_cache.h"
  50 #endif
  51 #include "fs_context.h"
  52 #include "cifs_swn.h"
  53
  54 extern mempool_t *cifs_req_poolp;
  55 extern bool disable_legacy_dialects;
  56
  57 /* FIXME: should these be tunable? */
  58 #define TLINK_ERROR_EXPIRE      (1 * HZ)
  59 #define TLINK_IDLE_EXPIRE       (600 * HZ)
  60
  61 /* Drop the connection to not overload the server */
  62 #define NUM_STATUS_IO_TIMEOUT   5
  63
  64 struct mount_ctx {
  65         struct cifs_sb_info *cifs_sb;
  66         struct smb3_fs_context *fs_ctx;
  67         unsigned int xid;
  68         struct TCP_Server_Info *server;
  69         struct cifs_ses *ses;
  70         struct cifs_tcon *tcon;
  71 #ifdef CONFIG_CIFS_DFS_UPCALL
  72         struct cifs_ses *root_ses;
  73         uuid_t mount_id;
  74         char *origin_fullpath, *leaf_fullpath;
  75 #endif
  76 };
  77
  78 static int ip_connect(struct TCP_Server_Info *server);
  79 static int generic_ip_connect(struct TCP_Server_Info *server);
  80 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  81 static void cifs_prune_tlinks(struct work_struct *work);
  82
  83 /*
  84  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  85  * get their ip addresses changed at some point.
  86  *
  87  * This should be called with server->srv_mutex held.
  88  */
  89 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  90 {
  91         int rc;
  92         int len;
  93         char *unc, *ipaddr = NULL;
  94         time64_t expiry, now;
  95         unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  96
  97         if (!server->hostname)
  98                 return -EINVAL;
  99
 100         len = strlen(server->hostname) + 3;
 101
 102         unc = kmalloc(len, GFP_KERNEL);
 103         if (!unc) {
 104                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
 105                 return -ENOMEM;
 106         }
 107         scnprintf(unc, len, "\\\\%s", server->hostname);
 108
 109         rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
 110         kfree(unc);
 111
 112         if (rc < 0) {
 113                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 114                          __func__, server->hostname, rc);
 115                 goto requeue_resolve;
 116         }
 117
 118         spin_lock(&cifs_tcp_ses_lock);
 119         rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 120                                   strlen(ipaddr));
 121         spin_unlock(&cifs_tcp_ses_lock);
 122         kfree(ipaddr);
 123
 124         /* rc == 1 means success here */
 125         if (rc) {
 126                 now = ktime_get_real_seconds();
 127                 if (expiry && expiry > now)
 128                         /*
 129                          * To make sure we don't use the cached entry, retry 1s
 130                          * after expiry.
 131                          */
 132                         ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 133         }
 134         rc = !rc ? -1 : 0;
 135
 136 requeue_resolve:
 137         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 138                  __func__, ttl);
 139         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 140
 141         return rc;
 142 }
 143
 144
 145 static void cifs_resolve_server(struct work_struct *work)
 146 {
 147         int rc;
 148         struct TCP_Server_Info *server = container_of(work,
 149                                         struct TCP_Server_Info, resolve.work);
 150
 151         mutex_lock(&server->srv_mutex);
 152
 153         /*
 154          * Resolve the hostname again to make sure that IP address is up-to-date.
 155          */
 156         rc = reconn_set_ipaddr_from_hostname(server);
 157         if (rc) {
 158                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 159                                 __func__, rc);
 160         }
 161
 162         mutex_unlock(&server->srv_mutex);
 163 }
 164
 165 /**
 166  * Mark all sessions and tcons for reconnect.
 167  *
 168  * @server needs to be previously set to CifsNeedReconnect.
 169  */
 170 static void cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server)
 171 {
 172         struct list_head *tmp, *tmp2;
 173         struct cifs_ses *ses;
 174         struct cifs_tcon *tcon;
 175         struct mid_q_entry *mid_entry;
 176         struct list_head retry_list;
 177
 178         server->maxBuf = 0;
 179         server->max_read = 0;
 180
 181         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 182         trace_smb3_reconnect(server->CurrentMid, server->conn_id, server->hostname);
 183         /*
 184          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 185          * are not used until reconnected.
 186          */
 187         cifs_dbg(FYI, "%s: marking sessions and tcons for reconnect\n", __func__);
 188         spin_lock(&cifs_tcp_ses_lock);
 189         list_for_each(tmp, &server->smb_ses_list) {
 190                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 191                 ses->need_reconnect = true;
 192                 list_for_each(tmp2, &ses->tcon_list) {
 193                         tcon = list_entry(tmp2, struct cifs_tcon, tcon_list);
 194                         tcon->need_reconnect = true;
 195                 }
 196                 if (ses->tcon_ipc)
 197                         ses->tcon_ipc->need_reconnect = true;
 198         }
 199         spin_unlock(&cifs_tcp_ses_lock);
 200
 201         /* do not want to be sending data on a socket we are freeing */
 202         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 203         mutex_lock(&server->srv_mutex);
 204         if (server->ssocket) {
 205                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 206                          server->ssocket->flags);
 207                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 208                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 209                          server->ssocket->flags);
 210                 sock_release(server->ssocket);
 211                 server->ssocket = NULL;
 212         }
 213         server->sequence_number = 0;
 214         server->session_estab = false;
 215         kfree(server->session_key.response);
 216         server->session_key.response = NULL;
 217         server->session_key.len = 0;
 218         server->lstrp = jiffies;
 219
 220         /* mark submitted MIDs for retry and issue callback */
 221         INIT_LIST_HEAD(&retry_list);
 222         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 223         spin_lock(&GlobalMid_Lock);
 224         list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 225                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 226                 kref_get(&mid_entry->refcount);
 227                 if (mid_entry->mid_state == MID_REQUEST_SUBMITTED)
 228                         mid_entry->mid_state = MID_RETRY_NEEDED;
 229                 list_move(&mid_entry->qhead, &retry_list);
 230                 mid_entry->mid_flags |= MID_DELETED;
 231         }
 232         spin_unlock(&GlobalMid_Lock);
 233         mutex_unlock(&server->srv_mutex);
 234
 235         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 236         list_for_each_safe(tmp, tmp2, &retry_list) {
 237                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 238                 list_del_init(&mid_entry->qhead);
 239                 mid_entry->callback(mid_entry);
 240                 cifs_mid_q_entry_release(mid_entry);
 241         }
 242
 243         if (cifs_rdma_enabled(server)) {
 244                 mutex_lock(&server->srv_mutex);
 245                 smbd_destroy(server);
 246                 mutex_unlock(&server->srv_mutex);
 247         }
 248 }
 249
 250 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 251 {
 252         spin_lock(&GlobalMid_Lock);
 253         server->nr_targets = num_targets;
 254         if (server->tcpStatus == CifsExiting) {
 255                 /* the demux thread will exit normally next time through the loop */
 256                 spin_unlock(&GlobalMid_Lock);
 257                 wake_up(&server->response_q);
 258                 return false;
 259         }
 260         server->tcpStatus = CifsNeedReconnect;
 261         spin_unlock(&GlobalMid_Lock);
 262         return true;
 263 }
 264
 265 /*
 266  * cifs tcp session reconnection
 267  *
 268  * mark tcp session as reconnecting so temporarily locked
 269  * mark all smb sessions as reconnecting for tcp session
 270  * reconnect tcp session
 271  * wake up waiters on reconnection? - (not needed currently)
 272  */
 273 static int __cifs_reconnect(struct TCP_Server_Info *server)
 274 {
 275         int rc = 0;
 276
 277         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 278                 return 0;
 279
 280         cifs_mark_tcp_ses_conns_for_reconnect(server);
 281
 282         do {
 283                 try_to_freeze();
 284                 mutex_lock(&server->srv_mutex);
 285
 286                 if (!cifs_swn_set_server_dstaddr(server)) {
 287                         /* resolve the hostname again to make sure that IP address is up-to-date */
 288                         rc = reconn_set_ipaddr_from_hostname(server);
 289                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 290                 }
 291
 292                 if (cifs_rdma_enabled(server))
 293                         rc = smbd_reconnect(server);
 294                 else
 295                         rc = generic_ip_connect(server);
 296                 if (rc) {
 297                         mutex_unlock(&server->srv_mutex);
 298                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 299                         msleep(3000);
 300                 } else {
 301                         atomic_inc(&tcpSesReconnectCount);
 302                         set_credits(server, 1);
 303                         spin_lock(&GlobalMid_Lock);
 304                         if (server->tcpStatus != CifsExiting)
 305                                 server->tcpStatus = CifsNeedNegotiate;
 306                         spin_unlock(&GlobalMid_Lock);
 307                         cifs_swn_reset_server_dstaddr(server);
 308                         mutex_unlock(&server->srv_mutex);
 309                 }
 310         } while (server->tcpStatus == CifsNeedReconnect);
 311
 312         if (server->tcpStatus == CifsNeedNegotiate)
 313                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 314
 315         wake_up(&server->response_q);
 316         return rc;
 317 }
 318
 319 #ifdef CONFIG_CIFS_DFS_UPCALL
 320 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 321 {
 322         int rc;
 323         char *hostname;
 324
 325         if (!cifs_swn_set_server_dstaddr(server)) {
 326                 if (server->hostname != target) {
 327                         hostname = extract_hostname(target);
 328                         if (!IS_ERR(hostname)) {
 329                                 kfree(server->hostname);
 330                                 server->hostname = hostname;
 331                         } else {
 332                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 333                                          __func__, PTR_ERR(hostname));
 334                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 335                                          server->hostname);
 336                         }
 337                 }
 338                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 339                 rc = reconn_set_ipaddr_from_hostname(server);
 340                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 341         }
 342         /* Reconnect the socket */
 343         if (cifs_rdma_enabled(server))
 344                 rc = smbd_reconnect(server);
 345         else
 346                 rc = generic_ip_connect(server);
 347
 348         return rc;
 349 }
 350
 351 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 352                                      struct dfs_cache_tgt_iterator **target_hint)
 353 {
 354         int rc;
 355         struct dfs_cache_tgt_iterator *tit;
 356
 357         *target_hint = NULL;
 358
 359         /* If dfs target list is empty, then reconnect to last server */
 360         tit = dfs_cache_get_tgt_iterator(tl);
 361         if (!tit)
 362                 return __reconnect_target_unlocked(server, server->hostname);
 363
 364         /* Otherwise, try every dfs target in @tl */
 365         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 366                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 367                 if (!rc) {
 368                         *target_hint = tit;
 369                         break;
 370                 }
 371         }
 372         return rc;
 373 }
 374
 375 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 376 {
 377         int rc = 0;
 378         const char *refpath = server->current_fullpath + 1;
 379         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 380         struct dfs_cache_tgt_iterator *target_hint = NULL;
 381         int num_targets = 0;
 382
 383         /*
 384          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 385          *
 386          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 387          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 388          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 389          * refreshing the referral, so, in this case, default it to 1.
 390          */
 391         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 392                 num_targets = dfs_cache_get_nr_tgts(&tl);
 393         if (!num_targets)
 394                 num_targets = 1;
 395
 396         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 397                 return 0;
 398
 399         cifs_mark_tcp_ses_conns_for_reconnect(server);
 400
 401         do {
 402                 try_to_freeze();
 403                 mutex_lock(&server->srv_mutex);
 404
 405                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 406                 if (rc) {
 407                         /* Failed to reconnect socket */
 408                         mutex_unlock(&server->srv_mutex);
 409                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 410                         msleep(3000);
 411                         continue;
 412                 }
 413                 /*
 414                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 415                  * process waiting for reconnect will know it needs to re-establish session and tcon
 416                  * through the reconnected target server.
 417                  */
 418                 atomic_inc(&tcpSesReconnectCount);
 419                 set_credits(server, 1);
 420                 spin_lock(&GlobalMid_Lock);
 421                 if (server->tcpStatus != CifsExiting)
 422                         server->tcpStatus = CifsNeedNegotiate;
 423                 spin_unlock(&GlobalMid_Lock);
 424                 cifs_swn_reset_server_dstaddr(server);
 425                 mutex_unlock(&server->srv_mutex);
 426         } while (server->tcpStatus == CifsNeedReconnect);
 427
 428         if (target_hint)
 429                 dfs_cache_noreq_update_tgthint(refpath, target_hint);
 430
 431         dfs_cache_free_tgts(&tl);
 432
 433         /* Need to set up echo worker again once connection has been established */
 434         if (server->tcpStatus == CifsNeedNegotiate)
 435                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 436
 437         wake_up(&server->response_q);
 438         return rc;
 439 }
 440
 441 int cifs_reconnect(struct TCP_Server_Info *server)
 442 {
 443         /* If tcp session is not an dfs connection, then reconnect to last target server */
 444         spin_lock(&cifs_tcp_ses_lock);
 445         if (!server->is_dfs_conn || !server->origin_fullpath || !server->leaf_fullpath) {
 446                 spin_unlock(&cifs_tcp_ses_lock);
 447                 return __cifs_reconnect(server);
 448         }
 449         spin_unlock(&cifs_tcp_ses_lock);
 450
 451         return reconnect_dfs_server(server);
 452 }
 453 #else
 454 int cifs_reconnect(struct TCP_Server_Info *server)
 455 {
 456         return __cifs_reconnect(server);
 457 }
 458 #endif
 459
 460 static void
 461 cifs_echo_request(struct work_struct *work)
 462 {
 463         int rc;
 464         struct TCP_Server_Info *server = container_of(work,
 465                                         struct TCP_Server_Info, echo.work);
 466
 467         /*
 468          * We cannot send an echo if it is disabled.
 469          * Also, no need to ping if we got a response recently.
 470          */
 471
 472         if (server->tcpStatus == CifsNeedReconnect ||
 473             server->tcpStatus == CifsExiting ||
 474             server->tcpStatus == CifsNew ||
 475             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 476             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 477                 goto requeue_echo;
 478
 479         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 480         if (rc)
 481                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 482                          server->hostname);
 483
 484         /* Check witness registrations */
 485         cifs_swn_check();
 486
 487 requeue_echo:
 488         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 489 }
 490
 491 static bool
 492 allocate_buffers(struct TCP_Server_Info *server)
 493 {
 494         if (!server->bigbuf) {
 495                 server->bigbuf = (char *)cifs_buf_get();
 496                 if (!server->bigbuf) {
 497                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 498                         msleep(3000);
 499                         /* retry will check if exiting */
 500                         return false;
 501                 }
 502         } else if (server->large_buf) {
 503                 /* we are reusing a dirty large buf, clear its start */
 504                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 505         }
 506
 507         if (!server->smallbuf) {
 508                 server->smallbuf = (char *)cifs_small_buf_get();
 509                 if (!server->smallbuf) {
 510                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 511                         msleep(1000);
 512                         /* retry will check if exiting */
 513                         return false;
 514                 }
 515                 /* beginning of smb buffer is cleared in our buf_get */
 516         } else {
 517                 /* if existing small buf clear beginning */
 518                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 519         }
 520
 521         return true;
 522 }
 523
 524 static bool
 525 server_unresponsive(struct TCP_Server_Info *server)
 526 {
 527         /*
 528          * We need to wait 3 echo intervals to make sure we handle such
 529          * situations right:
 530          * 1s  client sends a normal SMB request
 531          * 2s  client gets a response
 532          * 30s echo workqueue job pops, and decides we got a response recently
 533          *     and don't need to send another
 534          * ...
 535          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 536          *     a response in >60s.
 537          */
 538         if ((server->tcpStatus == CifsGood ||
 539             server->tcpStatus == CifsNeedNegotiate) &&
 540             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 541             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 542                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 543                          (3 * server->echo_interval) / HZ);
 544                 cifs_reconnect(server);
 545                 return true;
 546         }
 547
 548         return false;
 549 }
 550
 551 static inline bool
 552 zero_credits(struct TCP_Server_Info *server)
 553 {
 554         int val;
 555
 556         spin_lock(&server->req_lock);
 557         val = server->credits + server->echo_credits + server->oplock_credits;
 558         if (server->in_flight == 0 && val == 0) {
 559                 spin_unlock(&server->req_lock);
 560                 return true;
 561         }
 562         spin_unlock(&server->req_lock);
 563         return false;
 564 }
 565
 566 static int
 567 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 568 {
 569         int length = 0;
 570         int total_read;
 571
 572         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 573                 try_to_freeze();
 574
 575                 /* reconnect if no credits and no requests in flight */
 576                 if (zero_credits(server)) {
 577                         cifs_reconnect(server);
 578                         return -ECONNABORTED;
 579                 }
 580
 581                 if (server_unresponsive(server))
 582                         return -ECONNABORTED;
 583                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 584                         length = smbd_recv(server->smbd_conn, smb_msg);
 585                 else
 586                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 587
 588                 if (server->tcpStatus == CifsExiting)
 589                         return -ESHUTDOWN;
 590
 591                 if (server->tcpStatus == CifsNeedReconnect) {
 592                         cifs_reconnect(server);
 593                         return -ECONNABORTED;
 594                 }
 595
 596                 if (length == -ERESTARTSYS ||
 597                     length == -EAGAIN ||
 598                     length == -EINTR) {
 599                         /*
 600                          * Minimum sleep to prevent looping, allowing socket
 601                          * to clear and app threads to set tcpStatus
 602                          * CifsNeedReconnect if server hung.
 603                          */
 604                         usleep_range(1000, 2000);
 605                         length = 0;
 606                         continue;
 607                 }
 608
 609                 if (length <= 0) {
 610                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 611                         cifs_reconnect(server);
 612                         return -ECONNABORTED;
 613                 }
 614         }
 615         return total_read;
 616 }
 617
 618 int
 619 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 620                       unsigned int to_read)
 621 {
 622         struct msghdr smb_msg = {};
 623         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 624         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 625
 626         return cifs_readv_from_socket(server, &smb_msg);
 627 }
 628
 629 ssize_t
 630 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 631 {
 632         struct msghdr smb_msg = {};
 633
 634         /*
 635          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 636          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 637          *  so little to initialize in struct msghdr
 638          */
 639         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 640
 641         return cifs_readv_from_socket(server, &smb_msg);
 642 }
 643
 644 int
 645 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 646         unsigned int page_offset, unsigned int to_read)
 647 {
 648         struct msghdr smb_msg = {};
 649         struct bio_vec bv = {
 650                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 651         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 652         return cifs_readv_from_socket(server, &smb_msg);
 653 }
 654
 655 static bool
 656 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 657 {
 658         /*
 659          * The first byte big endian of the length field,
 660          * is actually not part of the length but the type
 661          * with the most common, zero, as regular data.
 662          */
 663         switch (type) {
 664         case RFC1002_SESSION_MESSAGE:
 665                 /* Regular SMB response */
 666                 return true;
 667         case RFC1002_SESSION_KEEP_ALIVE:
 668                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 669                 break;
 670         case RFC1002_POSITIVE_SESSION_RESPONSE:
 671                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 672                 break;
 673         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 674                 /*
 675                  * We get this from Windows 98 instead of an error on
 676                  * SMB negprot response.
 677                  */
 678                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 679                 /* give server a second to clean up */
 680                 msleep(1000);
 681                 /*
 682                  * Always try 445 first on reconnect since we get NACK
 683                  * on some if we ever connected to port 139 (the NACK
 684                  * is since we do not begin with RFC1001 session
 685                  * initialize frame).
 686                  */
 687                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 688                 cifs_reconnect(server);
 689                 break;
 690         default:
 691                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 692                 cifs_reconnect(server);
 693         }
 694
 695         return false;
 696 }
 697
 698 void
 699 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 700 {
 701 #ifdef CONFIG_CIFS_STATS2
 702         mid->when_received = jiffies;
 703 #endif
 704         spin_lock(&GlobalMid_Lock);
 705         if (!malformed)
 706                 mid->mid_state = MID_RESPONSE_RECEIVED;
 707         else
 708                 mid->mid_state = MID_RESPONSE_MALFORMED;
 709         /*
 710          * Trying to handle/dequeue a mid after the send_recv()
 711          * function has finished processing it is a bug.
 712          */
 713         if (mid->mid_flags & MID_DELETED)
 714                 pr_warn_once("trying to dequeue a deleted mid\n");
 715         else {
 716                 list_del_init(&mid->qhead);
 717                 mid->mid_flags |= MID_DELETED;
 718         }
 719         spin_unlock(&GlobalMid_Lock);
 720 }
 721
 722 static unsigned int
 723 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 724 {
 725         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 726
 727         /*
 728          * SMB1 does not use credits.
 729          */
 730         if (server->vals->header_preamble_size)
 731                 return 0;
 732
 733         return le16_to_cpu(shdr->CreditRequest);
 734 }
 735
 736 static void
 737 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 738            char *buf, int malformed)
 739 {
 740         if (server->ops->check_trans2 &&
 741             server->ops->check_trans2(mid, server, buf, malformed))
 742                 return;
 743         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 744         mid->resp_buf = buf;
 745         mid->large_buf = server->large_buf;
 746         /* Was previous buf put in mpx struct for multi-rsp? */
 747         if (!mid->multiRsp) {
 748                 /* smb buffer will be freed by user thread */
 749                 if (server->large_buf)
 750                         server->bigbuf = NULL;
 751                 else
 752                         server->smallbuf = NULL;
 753         }
 754         dequeue_mid(mid, malformed);
 755 }
 756
 757 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 758 {
 759         int length;
 760
 761         /* take it off the list, if it's not already */
 762         spin_lock(&cifs_tcp_ses_lock);
 763         list_del_init(&server->tcp_ses_list);
 764         spin_unlock(&cifs_tcp_ses_lock);
 765
 766         cancel_delayed_work_sync(&server->echo);
 767         cancel_delayed_work_sync(&server->resolve);
 768
 769         spin_lock(&GlobalMid_Lock);
 770         server->tcpStatus = CifsExiting;
 771         spin_unlock(&GlobalMid_Lock);
 772         wake_up_all(&server->response_q);
 773
 774         /* check if we have blocked requests that need to free */
 775         spin_lock(&server->req_lock);
 776         if (server->credits <= 0)
 777                 server->credits = 1;
 778         spin_unlock(&server->req_lock);
 779         /*
 780          * Although there should not be any requests blocked on this queue it
 781          * can not hurt to be paranoid and try to wake up requests that may
 782          * haven been blocked when more than 50 at time were on the wire to the
 783          * same server - they now will see the session is in exit state and get
 784          * out of SendReceive.
 785          */
 786         wake_up_all(&server->request_q);
 787         /* give those requests time to exit */
 788         msleep(125);
 789         if (cifs_rdma_enabled(server))
 790                 smbd_destroy(server);
 791         if (server->ssocket) {
 792                 sock_release(server->ssocket);
 793                 server->ssocket = NULL;
 794         }
 795
 796         if (!list_empty(&server->pending_mid_q)) {
 797                 struct list_head dispose_list;
 798                 struct mid_q_entry *mid_entry;
 799                 struct list_head *tmp, *tmp2;
 800
 801                 INIT_LIST_HEAD(&dispose_list);
 802                 spin_lock(&GlobalMid_Lock);
 803                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 804                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 805                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 806                         kref_get(&mid_entry->refcount);
 807                         mid_entry->mid_state = MID_SHUTDOWN;
 808                         list_move(&mid_entry->qhead, &dispose_list);
 809                         mid_entry->mid_flags |= MID_DELETED;
 810                 }
 811                 spin_unlock(&GlobalMid_Lock);
 812
 813                 /* now walk dispose list and issue callbacks */
 814                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 815                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 816                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 817                         list_del_init(&mid_entry->qhead);
 818                         mid_entry->callback(mid_entry);
 819                         cifs_mid_q_entry_release(mid_entry);
 820                 }
 821                 /* 1/8th of sec is more than enough time for them to exit */
 822                 msleep(125);
 823         }
 824
 825         if (!list_empty(&server->pending_mid_q)) {
 826                 /*
 827                  * mpx threads have not exited yet give them at least the smb
 828                  * send timeout time for long ops.
 829                  *
 830                  * Due to delays on oplock break requests, we need to wait at
 831                  * least 45 seconds before giving up on a request getting a
 832                  * response and going ahead and killing cifsd.
 833                  */
 834                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 835                 msleep(46000);
 836                 /*
 837                  * If threads still have not exited they are probably never
 838                  * coming home not much else we can do but free the memory.
 839                  */
 840         }
 841
 842 #ifdef CONFIG_CIFS_DFS_UPCALL
 843         kfree(server->origin_fullpath);
 844         kfree(server->leaf_fullpath);
 845 #endif
 846         kfree(server);
 847
 848         length = atomic_dec_return(&tcpSesAllocCount);
 849         if (length > 0)
 850                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 851 }
 852
 853 static int
 854 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 855 {
 856         int length;
 857         char *buf = server->smallbuf;
 858         unsigned int pdu_length = server->pdu_size;
 859
 860         /* make sure this will fit in a large buffer */
 861         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
 862                 server->vals->header_preamble_size) {
 863                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 864                 cifs_reconnect(server);
 865                 return -ECONNABORTED;
 866         }
 867
 868         /* switch to large buffer if too big for a small one */
 869         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
 870                 server->large_buf = true;
 871                 memcpy(server->bigbuf, buf, server->total_read);
 872                 buf = server->bigbuf;
 873         }
 874
 875         /* now read the rest */
 876         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
 877                                        pdu_length - HEADER_SIZE(server) + 1
 878                                        + server->vals->header_preamble_size);
 879
 880         if (length < 0)
 881                 return length;
 882         server->total_read += length;
 883
 884         dump_smb(buf, server->total_read);
 885
 886         return cifs_handle_standard(server, mid);
 887 }
 888
 889 int
 890 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 891 {
 892         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
 893         int length;
 894
 895         /*
 896          * We know that we received enough to get to the MID as we
 897          * checked the pdu_length earlier. Now check to see
 898          * if the rest of the header is OK. We borrow the length
 899          * var for the rest of the loop to avoid a new stack var.
 900          *
 901          * 48 bytes is enough to display the header and a little bit
 902          * into the payload for debugging purposes.
 903          */
 904         length = server->ops->check_message(buf, server->total_read, server);
 905         if (length != 0)
 906                 cifs_dump_mem("Bad SMB: ", buf,
 907                         min_t(unsigned int, server->total_read, 48));
 908
 909         if (server->ops->is_session_expired &&
 910             server->ops->is_session_expired(buf)) {
 911                 cifs_reconnect(server);
 912                 return -1;
 913         }
 914
 915         if (server->ops->is_status_pending &&
 916             server->ops->is_status_pending(buf, server))
 917                 return -1;
 918
 919         if (!mid)
 920                 return length;
 921
 922         handle_mid(mid, server, buf, length);
 923         return 0;
 924 }
 925
 926 static void
 927 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 928 {
 929         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 930         int scredits, in_flight;
 931
 932         /*
 933          * SMB1 does not use credits.
 934          */
 935         if (server->vals->header_preamble_size)
 936                 return;
 937
 938         if (shdr->CreditRequest) {
 939                 spin_lock(&server->req_lock);
 940                 server->credits += le16_to_cpu(shdr->CreditRequest);
 941                 scredits = server->credits;
 942                 in_flight = server->in_flight;
 943                 spin_unlock(&server->req_lock);
 944                 wake_up(&server->request_q);
 945
 946                 trace_smb3_add_credits(server->CurrentMid,
 947                                 server->conn_id, server->hostname, scredits,
 948                                 le16_to_cpu(shdr->CreditRequest), in_flight);
 949                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
 950                                 __func__, le16_to_cpu(shdr->CreditRequest),
 951                                 scredits);
 952         }
 953 }
 954
 955
 956 static int
 957 cifs_demultiplex_thread(void *p)
 958 {
 959         int i, num_mids, length;
 960         struct TCP_Server_Info *server = p;
 961         unsigned int pdu_length;
 962         unsigned int next_offset;
 963         char *buf = NULL;
 964         struct task_struct *task_to_wake = NULL;
 965         struct mid_q_entry *mids[MAX_COMPOUND];
 966         char *bufs[MAX_COMPOUND];
 967         unsigned int noreclaim_flag, num_io_timeout = 0;
 968
 969         noreclaim_flag = memalloc_noreclaim_save();
 970         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
 971
 972         length = atomic_inc_return(&tcpSesAllocCount);
 973         if (length > 1)
 974                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 975
 976         set_freezable();
 977         allow_kernel_signal(SIGKILL);
 978         while (server->tcpStatus != CifsExiting) {
 979                 if (try_to_freeze())
 980                         continue;
 981
 982                 if (!allocate_buffers(server))
 983                         continue;
 984
 985                 server->large_buf = false;
 986                 buf = server->smallbuf;
 987                 pdu_length = 4; /* enough to get RFC1001 header */
 988
 989                 length = cifs_read_from_socket(server, buf, pdu_length);
 990                 if (length < 0)
 991                         continue;
 992
 993                 if (server->vals->header_preamble_size == 0)
 994                         server->total_read = 0;
 995                 else
 996                         server->total_read = length;
 997
 998                 /*
 999                  * The right amount was read from socket - 4 bytes,
1000                  * so we can now interpret the length field.
1001                  */
1002                 pdu_length = get_rfc1002_length(buf);
1003
1004                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1005                 if (!is_smb_response(server, buf[0]))
1006                         continue;
1007 next_pdu:
1008                 server->pdu_size = pdu_length;
1009
1010                 /* make sure we have enough to get to the MID */
1011                 if (server->pdu_size < HEADER_SIZE(server) - 1 -
1012                     server->vals->header_preamble_size) {
1013                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1014                                  server->pdu_size);
1015                         cifs_reconnect(server);
1016                         continue;
1017                 }
1018
1019                 /* read down to the MID */
1020                 length = cifs_read_from_socket(server,
1021                              buf + server->vals->header_preamble_size,
1022                              HEADER_SIZE(server) - 1
1023                              - server->vals->header_preamble_size);
1024                 if (length < 0)
1025                         continue;
1026                 server->total_read += length;
1027
1028                 if (server->ops->next_header) {
1029                         next_offset = server->ops->next_header(buf);
1030                         if (next_offset)
1031                                 server->pdu_size = next_offset;
1032                 }
1033
1034                 memset(mids, 0, sizeof(mids));
1035                 memset(bufs, 0, sizeof(bufs));
1036                 num_mids = 0;
1037
1038                 if (server->ops->is_transform_hdr &&
1039                     server->ops->receive_transform &&
1040                     server->ops->is_transform_hdr(buf)) {
1041                         length = server->ops->receive_transform(server,
1042                                                                 mids,
1043                                                                 bufs,
1044                                                                 &num_mids);
1045                 } else {
1046                         mids[0] = server->ops->find_mid(server, buf);
1047                         bufs[0] = buf;
1048                         num_mids = 1;
1049
1050                         if (!mids[0] || !mids[0]->receive)
1051                                 length = standard_receive3(server, mids[0]);
1052                         else
1053                                 length = mids[0]->receive(server, mids[0]);
1054                 }
1055
1056                 if (length < 0) {
1057                         for (i = 0; i < num_mids; i++)
1058                                 if (mids[i])
1059                                         cifs_mid_q_entry_release(mids[i]);
1060                         continue;
1061                 }
1062
1063                 if (server->ops->is_status_io_timeout &&
1064                     server->ops->is_status_io_timeout(buf)) {
1065                         num_io_timeout++;
1066                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1067                                 cifs_reconnect(server);
1068                                 num_io_timeout = 0;
1069                                 continue;
1070                         }
1071                 }
1072
1073                 server->lstrp = jiffies;
1074
1075                 for (i = 0; i < num_mids; i++) {
1076                         if (mids[i] != NULL) {
1077                                 mids[i]->resp_buf_size = server->pdu_size;
1078
1079                                 if (bufs[i] && server->ops->is_network_name_deleted)
1080                                         server->ops->is_network_name_deleted(bufs[i],
1081                                                                         server);
1082
1083                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1084                                         mids[i]->callback(mids[i]);
1085
1086                                 cifs_mid_q_entry_release(mids[i]);
1087                         } else if (server->ops->is_oplock_break &&
1088                                    server->ops->is_oplock_break(bufs[i],
1089                                                                 server)) {
1090                                 smb2_add_credits_from_hdr(bufs[i], server);
1091                                 cifs_dbg(FYI, "Received oplock break\n");
1092                         } else {
1093                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1094                                                 atomic_read(&midCount));
1095                                 cifs_dump_mem("Received Data is: ", bufs[i],
1096                                               HEADER_SIZE(server));
1097                                 smb2_add_credits_from_hdr(bufs[i], server);
1098 #ifdef CONFIG_CIFS_DEBUG2
1099                                 if (server->ops->dump_detail)
1100                                         server->ops->dump_detail(bufs[i],
1101                                                                  server);
1102                                 cifs_dump_mids(server);
1103 #endif /* CIFS_DEBUG2 */
1104                         }
1105                 }
1106
1107                 if (pdu_length > server->pdu_size) {
1108                         if (!allocate_buffers(server))
1109                                 continue;
1110                         pdu_length -= server->pdu_size;
1111                         server->total_read = 0;
1112                         server->large_buf = false;
1113                         buf = server->smallbuf;
1114                         goto next_pdu;
1115                 }
1116         } /* end while !EXITING */
1117
1118         /* buffer usually freed in free_mid - need to free it here on exit */
1119         cifs_buf_release(server->bigbuf);
1120         if (server->smallbuf) /* no sense logging a debug message if NULL */
1121                 cifs_small_buf_release(server->smallbuf);
1122
1123         task_to_wake = xchg(&server->tsk, NULL);
1124         clean_demultiplex_info(server);
1125
1126         /* if server->tsk was NULL then wait for a signal before exiting */
1127         if (!task_to_wake) {
1128                 set_current_state(TASK_INTERRUPTIBLE);
1129                 while (!signal_pending(current)) {
1130                         schedule();
1131                         set_current_state(TASK_INTERRUPTIBLE);
1132                 }
1133                 set_current_state(TASK_RUNNING);
1134         }
1135
1136         memalloc_noreclaim_restore(noreclaim_flag);
1137         module_put_and_exit(0);
1138 }
1139
1140 /*
1141  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1142  * if srcaddr is specified and matches the IP address of the rhs argument
1143  */
1144 bool
1145 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1146 {
1147         switch (srcaddr->sa_family) {
1148         case AF_UNSPEC:
1149                 return (rhs->sa_family == AF_UNSPEC);
1150         case AF_INET: {
1151                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1152                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1153                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1154         }
1155         case AF_INET6: {
1156                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1157                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1158                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1159         }
1160         default:
1161                 WARN_ON(1);
1162                 return false; /* don't expect to be here */
1163         }
1164 }
1165
1166 /*
1167  * If no port is specified in addr structure, we try to match with 445 port
1168  * and if it fails - with 139 ports. It should be called only if address
1169  * families of server and addr are equal.
1170  */
1171 static bool
1172 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1173 {
1174         __be16 port, *sport;
1175
1176         /* SMBDirect manages its own ports, don't match it here */
1177         if (server->rdma)
1178                 return true;
1179
1180         switch (addr->sa_family) {
1181         case AF_INET:
1182                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1183                 port = ((struct sockaddr_in *) addr)->sin_port;
1184                 break;
1185         case AF_INET6:
1186                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1187                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1188                 break;
1189         default:
1190                 WARN_ON(1);
1191                 return false;
1192         }
1193
1194         if (!port) {
1195                 port = htons(CIFS_PORT);
1196                 if (port == *sport)
1197                         return true;
1198
1199                 port = htons(RFC1001_PORT);
1200         }
1201
1202         return port == *sport;
1203 }
1204
1205 static bool
1206 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1207               struct sockaddr *srcaddr)
1208 {
1209         switch (addr->sa_family) {
1210         case AF_INET: {
1211                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1212                 struct sockaddr_in *srv_addr4 =
1213                                         (struct sockaddr_in *)&server->dstaddr;
1214
1215                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1216                         return false;
1217                 break;
1218         }
1219         case AF_INET6: {
1220                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1221                 struct sockaddr_in6 *srv_addr6 =
1222                                         (struct sockaddr_in6 *)&server->dstaddr;
1223
1224                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1225                                      &srv_addr6->sin6_addr))
1226                         return false;
1227                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1228                         return false;
1229                 break;
1230         }
1231         default:
1232                 WARN_ON(1);
1233                 return false; /* don't expect to be here */
1234         }
1235
1236         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1237                 return false;
1238
1239         return true;
1240 }
1241
1242 static bool
1243 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1244 {
1245         /*
1246          * The select_sectype function should either return the ctx->sectype
1247          * that was specified, or "Unspecified" if that sectype was not
1248          * compatible with the given NEGOTIATE request.
1249          */
1250         if (server->ops->select_sectype(server, ctx->sectype)
1251              == Unspecified)
1252                 return false;
1253
1254         /*
1255          * Now check if signing mode is acceptable. No need to check
1256          * global_secflags at this point since if MUST_SIGN is set then
1257          * the server->sign had better be too.
1258          */
1259         if (ctx->sign && !server->sign)
1260                 return false;
1261
1262         return true;
1263 }
1264
1265 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1266 {
1267         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1268
1269         if (ctx->nosharesock)
1270                 return 0;
1271
1272         /* this server does not share socket */
1273         if (server->nosharesock)
1274                 return 0;
1275
1276         /* If multidialect negotiation see if existing sessions match one */
1277         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1278                 if (server->vals->protocol_id < SMB30_PROT_ID)
1279                         return 0;
1280         } else if (strcmp(ctx->vals->version_string,
1281                    SMBDEFAULT_VERSION_STRING) == 0) {
1282                 if (server->vals->protocol_id < SMB21_PROT_ID)
1283                         return 0;
1284         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1285                 return 0;
1286
1287         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1288                 return 0;
1289
1290         if (strcasecmp(server->hostname, ctx->server_hostname))
1291                 return 0;
1292
1293         if (!match_address(server, addr,
1294                            (struct sockaddr *)&ctx->srcaddr))
1295                 return 0;
1296
1297         if (!match_port(server, addr))
1298                 return 0;
1299
1300         if (!match_security(server, ctx))
1301                 return 0;
1302
1303         if (server->echo_interval != ctx->echo_interval * HZ)
1304                 return 0;
1305
1306         if (server->rdma != ctx->rdma)
1307                 return 0;
1308
1309         if (server->ignore_signature != ctx->ignore_signature)
1310                 return 0;
1311
1312         if (server->min_offload != ctx->min_offload)
1313                 return 0;
1314
1315         return 1;
1316 }
1317
1318 struct TCP_Server_Info *
1319 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1320 {
1321         struct TCP_Server_Info *server;
1322
1323         spin_lock(&cifs_tcp_ses_lock);
1324         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1325 #ifdef CONFIG_CIFS_DFS_UPCALL
1326                 /*
1327                  * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
1328                  * DFS connections to do failover properly, so avoid sharing them with regular
1329                  * shares or even links that may connect to same server but having completely
1330                  * different failover targets.
1331                  */
1332                 if (server->is_dfs_conn)
1333                         continue;
1334 #endif
1335                 /*
1336                  * Skip ses channels since they're only handled in lower layers
1337                  * (e.g. cifs_send_recv).
1338                  */
1339                 if (server->is_channel || !match_server(server, ctx))
1340                         continue;
1341
1342                 ++server->srv_count;
1343                 spin_unlock(&cifs_tcp_ses_lock);
1344                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1345                 return server;
1346         }
1347         spin_unlock(&cifs_tcp_ses_lock);
1348         return NULL;
1349 }
1350
1351 void
1352 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1353 {
1354         struct task_struct *task;
1355
1356         spin_lock(&cifs_tcp_ses_lock);
1357         if (--server->srv_count > 0) {
1358                 spin_unlock(&cifs_tcp_ses_lock);
1359                 return;
1360         }
1361
1362         /* srv_count can never go negative */
1363         WARN_ON(server->srv_count < 0);
1364
1365         put_net(cifs_net_ns(server));
1366
1367         list_del_init(&server->tcp_ses_list);
1368         spin_unlock(&cifs_tcp_ses_lock);
1369
1370         cancel_delayed_work_sync(&server->echo);
1371         cancel_delayed_work_sync(&server->resolve);
1372
1373         if (from_reconnect)
1374                 /*
1375                  * Avoid deadlock here: reconnect work calls
1376                  * cifs_put_tcp_session() at its end. Need to be sure
1377                  * that reconnect work does nothing with server pointer after
1378                  * that step.
1379                  */
1380                 cancel_delayed_work(&server->reconnect);
1381         else
1382                 cancel_delayed_work_sync(&server->reconnect);
1383
1384         spin_lock(&GlobalMid_Lock);
1385         server->tcpStatus = CifsExiting;
1386         spin_unlock(&GlobalMid_Lock);
1387
1388         cifs_crypto_secmech_release(server);
1389         cifs_fscache_release_client_cookie(server);
1390
1391         kfree(server->session_key.response);
1392         server->session_key.response = NULL;
1393         server->session_key.len = 0;
1394         kfree(server->hostname);
1395         server->hostname = NULL;
1396
1397         task = xchg(&server->tsk, NULL);
1398         if (task)
1399                 send_sig(SIGKILL, task, 1);
1400 }
1401
1402 struct TCP_Server_Info *
1403 cifs_get_tcp_session(struct smb3_fs_context *ctx)
1404 {
1405         struct TCP_Server_Info *tcp_ses = NULL;
1406         int rc;
1407
1408         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1409
1410         /* see if we already have a matching tcp_ses */
1411         tcp_ses = cifs_find_tcp_session(ctx);
1412         if (tcp_ses)
1413                 return tcp_ses;
1414
1415         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1416         if (!tcp_ses) {
1417                 rc = -ENOMEM;
1418                 goto out_err;
1419         }
1420
1421         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1422         if (!tcp_ses->hostname) {
1423                 rc = -ENOMEM;
1424                 goto out_err;
1425         }
1426
1427         if (ctx->nosharesock)
1428                 tcp_ses->nosharesock = true;
1429
1430         tcp_ses->ops = ctx->ops;
1431         tcp_ses->vals = ctx->vals;
1432         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1433
1434         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1435         tcp_ses->noblockcnt = ctx->rootfs;
1436         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1437         tcp_ses->noautotune = ctx->noautotune;
1438         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1439         tcp_ses->rdma = ctx->rdma;
1440         tcp_ses->in_flight = 0;
1441         tcp_ses->max_in_flight = 0;
1442         tcp_ses->credits = 1;
1443         init_waitqueue_head(&tcp_ses->response_q);
1444         init_waitqueue_head(&tcp_ses->request_q);
1445         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1446         mutex_init(&tcp_ses->srv_mutex);
1447         memcpy(tcp_ses->workstation_RFC1001_name,
1448                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1449         memcpy(tcp_ses->server_RFC1001_name,
1450                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1451         tcp_ses->session_estab = false;
1452         tcp_ses->sequence_number = 0;
1453         tcp_ses->reconnect_instance = 1;
1454         tcp_ses->lstrp = jiffies;
1455         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1456         spin_lock_init(&tcp_ses->req_lock);
1457         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1458         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1459         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1460         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1461         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1462         mutex_init(&tcp_ses->reconnect_mutex);
1463 #ifdef CONFIG_CIFS_DFS_UPCALL
1464         mutex_init(&tcp_ses->refpath_lock);
1465 #endif
1466         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1467                sizeof(tcp_ses->srcaddr));
1468         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1469                 sizeof(tcp_ses->dstaddr));
1470         if (ctx->use_client_guid)
1471                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1472                        SMB2_CLIENT_GUID_SIZE);
1473         else
1474                 generate_random_uuid(tcp_ses->client_guid);
1475         /*
1476          * at this point we are the only ones with the pointer
1477          * to the struct since the kernel thread not created yet
1478          * no need to spinlock this init of tcpStatus or srv_count
1479          */
1480         tcp_ses->tcpStatus = CifsNew;
1481         ++tcp_ses->srv_count;
1482
1483         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1484                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1485                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1486         else
1487                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1488         if (tcp_ses->rdma) {
1489 #ifndef CONFIG_CIFS_SMB_DIRECT
1490                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1491                 rc = -ENOENT;
1492                 goto out_err_crypto_release;
1493 #endif
1494                 tcp_ses->smbd_conn = smbd_get_connection(
1495                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1496                 if (tcp_ses->smbd_conn) {
1497                         cifs_dbg(VFS, "RDMA transport established\n");
1498                         rc = 0;
1499                         goto smbd_connected;
1500                 } else {
1501                         rc = -ENOENT;
1502                         goto out_err_crypto_release;
1503                 }
1504         }
1505         rc = ip_connect(tcp_ses);
1506         if (rc < 0) {
1507                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1508                 goto out_err_crypto_release;
1509         }
1510 smbd_connected:
1511         /*
1512          * since we're in a cifs function already, we know that
1513          * this will succeed. No need for try_module_get().
1514          */
1515         __module_get(THIS_MODULE);
1516         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1517                                   tcp_ses, "cifsd");
1518         if (IS_ERR(tcp_ses->tsk)) {
1519                 rc = PTR_ERR(tcp_ses->tsk);
1520                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1521                 module_put(THIS_MODULE);
1522                 goto out_err_crypto_release;
1523         }
1524         tcp_ses->min_offload = ctx->min_offload;
1525         /*
1526          * at this point we are the only ones with the pointer
1527          * to the struct since the kernel thread not created yet
1528          * no need to spinlock this update of tcpStatus
1529          */
1530         tcp_ses->tcpStatus = CifsNeedNegotiate;
1531
1532         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1533                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1534         else
1535                 tcp_ses->max_credits = ctx->max_credits;
1536
1537         tcp_ses->nr_targets = 1;
1538         tcp_ses->ignore_signature = ctx->ignore_signature;
1539         /* thread spawned, put it on the list */
1540         spin_lock(&cifs_tcp_ses_lock);
1541         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1542         spin_unlock(&cifs_tcp_ses_lock);
1543
1544         cifs_fscache_get_client_cookie(tcp_ses);
1545
1546         /* queue echo request delayed work */
1547         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1548
1549         /* queue dns resolution delayed work */
1550         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1551                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1552
1553         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1554
1555         return tcp_ses;
1556
1557 out_err_crypto_release:
1558         cifs_crypto_secmech_release(tcp_ses);
1559
1560         put_net(cifs_net_ns(tcp_ses));
1561
1562 out_err:
1563         if (tcp_ses) {
1564                 kfree(tcp_ses->hostname);
1565                 if (tcp_ses->ssocket)
1566                         sock_release(tcp_ses->ssocket);
1567                 kfree(tcp_ses);
1568         }
1569         return ERR_PTR(rc);
1570 }
1571
1572 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1573 {
1574         if (ctx->sectype != Unspecified &&
1575             ctx->sectype != ses->sectype)
1576                 return 0;
1577
1578         /*
1579          * If an existing session is limited to less channels than
1580          * requested, it should not be reused
1581          */
1582         spin_lock(&ses->chan_lock);
1583         if (ses->chan_max < ctx->max_channels) {
1584                 spin_unlock(&ses->chan_lock);
1585                 return 0;
1586         }
1587         spin_unlock(&ses->chan_lock);
1588
1589         switch (ses->sectype) {
1590         case Kerberos:
1591                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1592                         return 0;
1593                 break;
1594         default:
1595                 /* NULL username means anonymous session */
1596                 if (ses->user_name == NULL) {
1597                         if (!ctx->nullauth)
1598                                 return 0;
1599                         break;
1600                 }
1601
1602                 /* anything else takes username/password */
1603                 if (strncmp(ses->user_name,
1604                             ctx->username ? ctx->username : "",
1605                             CIFS_MAX_USERNAME_LEN))
1606                         return 0;
1607                 if ((ctx->username && strlen(ctx->username) != 0) &&
1608                     ses->password != NULL &&
1609                     strncmp(ses->password,
1610                             ctx->password ? ctx->password : "",
1611                             CIFS_MAX_PASSWORD_LEN))
1612                         return 0;
1613         }
1614         return 1;
1615 }
1616
1617 /**
1618  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1619  * @ses: smb session to issue the request on
1620  * @ctx: the superblock configuration context to use for building the
1621  *       new tree connection for the IPC (interprocess communication RPC)
1622  *
1623  * A new IPC connection is made and stored in the session
1624  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1625  */
1626 static int
1627 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1628 {
1629         int rc = 0, xid;
1630         struct cifs_tcon *tcon;
1631         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1632         bool seal = false;
1633         struct TCP_Server_Info *server = ses->server;
1634
1635         /*
1636          * If the mount request that resulted in the creation of the
1637          * session requires encryption, force IPC to be encrypted too.
1638          */
1639         if (ctx->seal) {
1640                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1641                         seal = true;
1642                 else {
1643                         cifs_server_dbg(VFS,
1644                                  "IPC: server doesn't support encryption\n");
1645                         return -EOPNOTSUPP;
1646                 }
1647         }
1648
1649         tcon = tconInfoAlloc();
1650         if (tcon == NULL)
1651                 return -ENOMEM;
1652
1653         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1654
1655         xid = get_xid();
1656         tcon->ses = ses;
1657         tcon->ipc = true;
1658         tcon->seal = seal;
1659         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1660         free_xid(xid);
1661
1662         if (rc) {
1663                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1664                 tconInfoFree(tcon);
1665                 goto out;
1666         }
1667
1668         cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid);
1669
1670         ses->tcon_ipc = tcon;
1671 out:
1672         return rc;
1673 }
1674
1675 /**
1676  * cifs_free_ipc - helper to release the session IPC tcon
1677  * @ses: smb session to unmount the IPC from
1678  *
1679  * Needs to be called everytime a session is destroyed.
1680  *
1681  * On session close, the IPC is closed and the server must release all tcons of the session.
1682  * No need to send a tree disconnect here.
1683  *
1684  * Besides, it will make the server to not close durable and resilient files on session close, as
1685  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1686  */
1687 static int
1688 cifs_free_ipc(struct cifs_ses *ses)
1689 {
1690         struct cifs_tcon *tcon = ses->tcon_ipc;
1691
1692         if (tcon == NULL)
1693                 return 0;
1694
1695         tconInfoFree(tcon);
1696         ses->tcon_ipc = NULL;
1697         return 0;
1698 }
1699
1700 static struct cifs_ses *
1701 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1702 {
1703         struct cifs_ses *ses;
1704
1705         spin_lock(&cifs_tcp_ses_lock);
1706         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1707                 if (ses->status == CifsExiting)
1708                         continue;
1709                 if (!match_session(ses, ctx))
1710                         continue;
1711                 ++ses->ses_count;
1712                 spin_unlock(&cifs_tcp_ses_lock);
1713                 return ses;
1714         }
1715         spin_unlock(&cifs_tcp_ses_lock);
1716         return NULL;
1717 }
1718
1719 void cifs_put_smb_ses(struct cifs_ses *ses)
1720 {
1721         unsigned int rc, xid;
1722         unsigned int chan_count;
1723         struct TCP_Server_Info *server = ses->server;
1724         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1725
1726         spin_lock(&cifs_tcp_ses_lock);
1727         if (ses->status == CifsExiting) {
1728                 spin_unlock(&cifs_tcp_ses_lock);
1729                 return;
1730         }
1731
1732         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1733         cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE");
1734
1735         if (--ses->ses_count > 0) {
1736                 spin_unlock(&cifs_tcp_ses_lock);
1737                 return;
1738         }
1739         spin_unlock(&cifs_tcp_ses_lock);
1740
1741         /* ses_count can never go negative */
1742         WARN_ON(ses->ses_count < 0);
1743
1744         spin_lock(&GlobalMid_Lock);
1745         if (ses->status == CifsGood)
1746                 ses->status = CifsExiting;
1747         spin_unlock(&GlobalMid_Lock);
1748
1749         cifs_free_ipc(ses);
1750
1751         if (ses->status == CifsExiting && server->ops->logoff) {
1752                 xid = get_xid();
1753                 rc = server->ops->logoff(xid, ses);
1754                 if (rc)
1755                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1756                                 __func__, rc);
1757                 _free_xid(xid);
1758         }
1759
1760         spin_lock(&cifs_tcp_ses_lock);
1761         list_del_init(&ses->smb_ses_list);
1762         spin_unlock(&cifs_tcp_ses_lock);
1763
1764         spin_lock(&ses->chan_lock);
1765         chan_count = ses->chan_count;
1766         spin_unlock(&ses->chan_lock);
1767
1768         /* close any extra channels */
1769         if (chan_count > 1) {
1770                 int i;
1771
1772                 for (i = 1; i < chan_count; i++) {
1773                         /*
1774                          * note: for now, we're okay accessing ses->chans
1775                          * without chan_lock. But when chans can go away, we'll
1776                          * need to introduce ref counting to make sure that chan
1777                          * is not freed from under us.
1778                          */
1779                         cifs_put_tcp_session(ses->chans[i].server, 0);
1780                         ses->chans[i].server = NULL;
1781                 }
1782         }
1783
1784         sesInfoFree(ses);
1785         cifs_put_tcp_session(server, 0);
1786 }
1787
1788 #ifdef CONFIG_KEYS
1789
1790 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1791 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1792
1793 /* Populate username and pw fields from keyring if possible */
1794 static int
1795 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1796 {
1797         int rc = 0;
1798         int is_domain = 0;
1799         const char *delim, *payload;
1800         char *desc;
1801         ssize_t len;
1802         struct key *key;
1803         struct TCP_Server_Info *server = ses->server;
1804         struct sockaddr_in *sa;
1805         struct sockaddr_in6 *sa6;
1806         const struct user_key_payload *upayload;
1807
1808         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1809         if (!desc)
1810                 return -ENOMEM;
1811
1812         /* try to find an address key first */
1813         switch (server->dstaddr.ss_family) {
1814         case AF_INET:
1815                 sa = (struct sockaddr_in *)&server->dstaddr;
1816                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1817                 break;
1818         case AF_INET6:
1819                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1820                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1821                 break;
1822         default:
1823                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1824                          server->dstaddr.ss_family);
1825                 rc = -EINVAL;
1826                 goto out_err;
1827         }
1828
1829         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1830         key = request_key(&key_type_logon, desc, "");
1831         if (IS_ERR(key)) {
1832                 if (!ses->domainName) {
1833                         cifs_dbg(FYI, "domainName is NULL\n");
1834                         rc = PTR_ERR(key);
1835                         goto out_err;
1836                 }
1837
1838                 /* didn't work, try to find a domain key */
1839                 sprintf(desc, "cifs:d:%s", ses->domainName);
1840                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1841                 key = request_key(&key_type_logon, desc, "");
1842                 if (IS_ERR(key)) {
1843                         rc = PTR_ERR(key);
1844                         goto out_err;
1845                 }
1846                 is_domain = 1;
1847         }
1848
1849         down_read(&key->sem);
1850         upayload = user_key_payload_locked(key);
1851         if (IS_ERR_OR_NULL(upayload)) {
1852                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1853                 goto out_key_put;
1854         }
1855
1856         /* find first : in payload */
1857         payload = upayload->data;
1858         delim = strnchr(payload, upayload->datalen, ':');
1859         cifs_dbg(FYI, "payload=%s\n", payload);
1860         if (!delim) {
1861                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1862                          upayload->datalen);
1863                 rc = -EINVAL;
1864                 goto out_key_put;
1865         }
1866
1867         len = delim - payload;
1868         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1869                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1870                          len);
1871                 rc = -EINVAL;
1872                 goto out_key_put;
1873         }
1874
1875         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1876         if (!ctx->username) {
1877                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1878                          len);
1879                 rc = -ENOMEM;
1880                 goto out_key_put;
1881         }
1882         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
1883
1884         len = key->datalen - (len + 1);
1885         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
1886                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
1887                 rc = -EINVAL;
1888                 kfree(ctx->username);
1889                 ctx->username = NULL;
1890                 goto out_key_put;
1891         }
1892
1893         ++delim;
1894         ctx->password = kstrndup(delim, len, GFP_KERNEL);
1895         if (!ctx->password) {
1896                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
1897                          len);
1898                 rc = -ENOMEM;
1899                 kfree(ctx->username);
1900                 ctx->username = NULL;
1901                 goto out_key_put;
1902         }
1903
1904         /*
1905          * If we have a domain key then we must set the domainName in the
1906          * for the request.
1907          */
1908         if (is_domain && ses->domainName) {
1909                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
1910                 if (!ctx->domainname) {
1911                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
1912                                  len);
1913                         rc = -ENOMEM;
1914                         kfree(ctx->username);
1915                         ctx->username = NULL;
1916                         kfree_sensitive(ctx->password);
1917                         ctx->password = NULL;
1918                         goto out_key_put;
1919                 }
1920         }
1921
1922 out_key_put:
1923         up_read(&key->sem);
1924         key_put(key);
1925 out_err:
1926         kfree(desc);
1927         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
1928         return rc;
1929 }
1930 #else /* ! CONFIG_KEYS */
1931 static inline int
1932 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
1933                    struct cifs_ses *ses __attribute__((unused)))
1934 {
1935         return -ENOSYS;
1936 }
1937 #endif /* CONFIG_KEYS */
1938
1939 /**
1940  * cifs_get_smb_ses - get a session matching @ctx data from @server
1941  * @server: server to setup the session to
1942  * @ctx: superblock configuration context to use to setup the session
1943  *
1944  * This function assumes it is being called from cifs_mount() where we
1945  * already got a server reference (server refcount +1). See
1946  * cifs_get_tcon() for refcount explanations.
1947  */
1948 struct cifs_ses *
1949 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1950 {
1951         int rc = 0;
1952         unsigned int xid;
1953         struct cifs_ses *ses;
1954         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
1955         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
1956
1957         xid = get_xid();
1958
1959         ses = cifs_find_smb_ses(server, ctx);
1960         if (ses) {
1961                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
1962                          ses->status);
1963
1964                 mutex_lock(&ses->session_mutex);
1965                 rc = cifs_negotiate_protocol(xid, ses);
1966                 if (rc) {
1967                         mutex_unlock(&ses->session_mutex);
1968                         /* problem -- put our ses reference */
1969                         cifs_put_smb_ses(ses);
1970                         free_xid(xid);
1971                         return ERR_PTR(rc);
1972                 }
1973                 if (ses->need_reconnect) {
1974                         cifs_dbg(FYI, "Session needs reconnect\n");
1975                         rc = cifs_setup_session(xid, ses,
1976                                                 ctx->local_nls);
1977                         if (rc) {
1978                                 mutex_unlock(&ses->session_mutex);
1979                                 /* problem -- put our reference */
1980                                 cifs_put_smb_ses(ses);
1981                                 free_xid(xid);
1982                                 return ERR_PTR(rc);
1983                         }
1984                 }
1985                 mutex_unlock(&ses->session_mutex);
1986
1987                 /* existing SMB ses has a server reference already */
1988                 cifs_put_tcp_session(server, 0);
1989                 free_xid(xid);
1990                 return ses;
1991         }
1992
1993         rc = -ENOMEM;
1994
1995         cifs_dbg(FYI, "Existing smb sess not found\n");
1996         ses = sesInfoAlloc();
1997         if (ses == NULL)
1998                 goto get_ses_fail;
1999
2000         /* new SMB session uses our server ref */
2001         ses->server = server;
2002         if (server->dstaddr.ss_family == AF_INET6)
2003                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2004         else
2005                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2006
2007         if (ctx->username) {
2008                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2009                 if (!ses->user_name)
2010                         goto get_ses_fail;
2011         }
2012
2013         /* ctx->password freed at unmount */
2014         if (ctx->password) {
2015                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2016                 if (!ses->password)
2017                         goto get_ses_fail;
2018         }
2019         if (ctx->domainname) {
2020                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2021                 if (!ses->domainName)
2022                         goto get_ses_fail;
2023         }
2024         if (ctx->domainauto)
2025                 ses->domainAuto = ctx->domainauto;
2026         ses->cred_uid = ctx->cred_uid;
2027         ses->linux_uid = ctx->linux_uid;
2028
2029         ses->sectype = ctx->sectype;
2030         ses->sign = ctx->sign;
2031         mutex_lock(&ses->session_mutex);
2032
2033         /* add server as first channel */
2034         spin_lock(&ses->chan_lock);
2035         ses->chans[0].server = server;
2036         ses->chan_count = 1;
2037         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2038         spin_unlock(&ses->chan_lock);
2039
2040         rc = cifs_negotiate_protocol(xid, ses);
2041         if (!rc)
2042                 rc = cifs_setup_session(xid, ses, ctx->local_nls);
2043
2044         /* each channel uses a different signing key */
2045         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2046                sizeof(ses->smb3signingkey));
2047
2048         mutex_unlock(&ses->session_mutex);
2049         if (rc)
2050                 goto get_ses_fail;
2051
2052         /* success, put it on the list and add it as first channel */
2053         spin_lock(&cifs_tcp_ses_lock);
2054         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2055         spin_unlock(&cifs_tcp_ses_lock);
2056
2057         free_xid(xid);
2058
2059         cifs_setup_ipc(ses, ctx);
2060
2061         return ses;
2062
2063 get_ses_fail:
2064         sesInfoFree(ses);
2065         free_xid(xid);
2066         return ERR_PTR(rc);
2067 }
2068
2069 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2070 {
2071         if (tcon->tidStatus == CifsExiting)
2072                 return 0;
2073         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
2074                 return 0;
2075         if (tcon->seal != ctx->seal)
2076                 return 0;
2077         if (tcon->snapshot_time != ctx->snapshot_time)
2078                 return 0;
2079         if (tcon->handle_timeout != ctx->handle_timeout)
2080                 return 0;
2081         if (tcon->no_lease != ctx->no_lease)
2082                 return 0;
2083         if (tcon->nodelete != ctx->nodelete)
2084                 return 0;
2085         return 1;
2086 }
2087
2088 static struct cifs_tcon *
2089 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2090 {
2091         struct list_head *tmp;
2092         struct cifs_tcon *tcon;
2093
2094         spin_lock(&cifs_tcp_ses_lock);
2095         list_for_each(tmp, &ses->tcon_list) {
2096                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
2097
2098                 if (!match_tcon(tcon, ctx))
2099                         continue;
2100                 ++tcon->tc_count;
2101                 spin_unlock(&cifs_tcp_ses_lock);
2102                 return tcon;
2103         }
2104         spin_unlock(&cifs_tcp_ses_lock);
2105         return NULL;
2106 }
2107
2108 void
2109 cifs_put_tcon(struct cifs_tcon *tcon)
2110 {
2111         unsigned int xid;
2112         struct cifs_ses *ses;
2113
2114         /*
2115          * IPC tcon share the lifetime of their session and are
2116          * destroyed in the session put function
2117          */
2118         if (tcon == NULL || tcon->ipc)
2119                 return;
2120
2121         ses = tcon->ses;
2122         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2123         spin_lock(&cifs_tcp_ses_lock);
2124         if (--tcon->tc_count > 0) {
2125                 spin_unlock(&cifs_tcp_ses_lock);
2126                 return;
2127         }
2128
2129         /* tc_count can never go negative */
2130         WARN_ON(tcon->tc_count < 0);
2131
2132         if (tcon->use_witness) {
2133                 int rc;
2134
2135                 rc = cifs_swn_unregister(tcon);
2136                 if (rc < 0) {
2137                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2138                                         __func__, rc);
2139                 }
2140         }
2141
2142         list_del_init(&tcon->tcon_list);
2143         spin_unlock(&cifs_tcp_ses_lock);
2144
2145         xid = get_xid();
2146         if (ses->server->ops->tree_disconnect)
2147                 ses->server->ops->tree_disconnect(xid, tcon);
2148         _free_xid(xid);
2149
2150         cifs_fscache_release_super_cookie(tcon);
2151         tconInfoFree(tcon);
2152         cifs_put_smb_ses(ses);
2153 }
2154
2155 /**
2156  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2157  * @ses: smb session to issue the request on
2158  * @ctx: the superblock configuration context to use for building the
2159  *
2160  * - tcon refcount is the number of mount points using the tcon.
2161  * - ses refcount is the number of tcon using the session.
2162  *
2163  * 1. This function assumes it is being called from cifs_mount() where
2164  *    we already got a session reference (ses refcount +1).
2165  *
2166  * 2. Since we're in the context of adding a mount point, the end
2167  *    result should be either:
2168  *
2169  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2170  *    its session refcount incremented (1 new tcon). This +1 was
2171  *    already done in (1).
2172  *
2173  * b) an existing tcon with refcount+1 (add a mount point to it) and
2174  *    identical ses refcount (no new tcon). Because of (1) we need to
2175  *    decrement the ses refcount.
2176  */
2177 static struct cifs_tcon *
2178 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2179 {
2180         int rc, xid;
2181         struct cifs_tcon *tcon;
2182
2183         tcon = cifs_find_tcon(ses, ctx);
2184         if (tcon) {
2185                 /*
2186                  * tcon has refcount already incremented but we need to
2187                  * decrement extra ses reference gotten by caller (case b)
2188                  */
2189                 cifs_dbg(FYI, "Found match on UNC path\n");
2190                 cifs_put_smb_ses(ses);
2191                 return tcon;
2192         }
2193
2194         if (!ses->server->ops->tree_connect) {
2195                 rc = -ENOSYS;
2196                 goto out_fail;
2197         }
2198
2199         tcon = tconInfoAlloc();
2200         if (tcon == NULL) {
2201                 rc = -ENOMEM;
2202                 goto out_fail;
2203         }
2204
2205         if (ctx->snapshot_time) {
2206                 if (ses->server->vals->protocol_id == 0) {
2207                         cifs_dbg(VFS,
2208                              "Use SMB2 or later for snapshot mount option\n");
2209                         rc = -EOPNOTSUPP;
2210                         goto out_fail;
2211                 } else
2212                         tcon->snapshot_time = ctx->snapshot_time;
2213         }
2214
2215         if (ctx->handle_timeout) {
2216                 if (ses->server->vals->protocol_id == 0) {
2217                         cifs_dbg(VFS,
2218                              "Use SMB2.1 or later for handle timeout option\n");
2219                         rc = -EOPNOTSUPP;
2220                         goto out_fail;
2221                 } else
2222                         tcon->handle_timeout = ctx->handle_timeout;
2223         }
2224
2225         tcon->ses = ses;
2226         if (ctx->password) {
2227                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2228                 if (!tcon->password) {
2229                         rc = -ENOMEM;
2230                         goto out_fail;
2231                 }
2232         }
2233
2234         if (ctx->seal) {
2235                 if (ses->server->vals->protocol_id == 0) {
2236                         cifs_dbg(VFS,
2237                                  "SMB3 or later required for encryption\n");
2238                         rc = -EOPNOTSUPP;
2239                         goto out_fail;
2240                 } else if (tcon->ses->server->capabilities &
2241                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2242                         tcon->seal = true;
2243                 else {
2244                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2245                         rc = -EOPNOTSUPP;
2246                         goto out_fail;
2247                 }
2248         }
2249
2250         if (ctx->linux_ext) {
2251                 if (ses->server->posix_ext_supported) {
2252                         tcon->posix_extensions = true;
2253                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2254                 } else {
2255                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2256                         rc = -EOPNOTSUPP;
2257                         goto out_fail;
2258                 }
2259         }
2260
2261         /*
2262          * BB Do we need to wrap session_mutex around this TCon call and Unix
2263          * SetFS as we do on SessSetup and reconnect?
2264          */
2265         xid = get_xid();
2266         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2267                                             ctx->local_nls);
2268         free_xid(xid);
2269         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2270         if (rc)
2271                 goto out_fail;
2272
2273         tcon->use_persistent = false;
2274         /* check if SMB2 or later, CIFS does not support persistent handles */
2275         if (ctx->persistent) {
2276                 if (ses->server->vals->protocol_id == 0) {
2277                         cifs_dbg(VFS,
2278                              "SMB3 or later required for persistent handles\n");
2279                         rc = -EOPNOTSUPP;
2280                         goto out_fail;
2281                 } else if (ses->server->capabilities &
2282                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2283                         tcon->use_persistent = true;
2284                 else /* persistent handles requested but not supported */ {
2285                         cifs_dbg(VFS,
2286                                 "Persistent handles not supported on share\n");
2287                         rc = -EOPNOTSUPP;
2288                         goto out_fail;
2289                 }
2290         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2291              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2292              && (ctx->nopersistent == false)) {
2293                 cifs_dbg(FYI, "enabling persistent handles\n");
2294                 tcon->use_persistent = true;
2295         } else if (ctx->resilient) {
2296                 if (ses->server->vals->protocol_id == 0) {
2297                         cifs_dbg(VFS,
2298                              "SMB2.1 or later required for resilient handles\n");
2299                         rc = -EOPNOTSUPP;
2300                         goto out_fail;
2301                 }
2302                 tcon->use_resilient = true;
2303         }
2304
2305         tcon->use_witness = false;
2306         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2307                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2308                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2309                                 /*
2310                                  * Set witness in use flag in first place
2311                                  * to retry registration in the echo task
2312                                  */
2313                                 tcon->use_witness = true;
2314                                 /* And try to register immediately */
2315                                 rc = cifs_swn_register(tcon);
2316                                 if (rc < 0) {
2317                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2318                                         goto out_fail;
2319                                 }
2320                         } else {
2321                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2322                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2323                                 rc = -EOPNOTSUPP;
2324                                 goto out_fail;
2325                         }
2326                 } else {
2327                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2328                         rc = -EOPNOTSUPP;
2329                         goto out_fail;
2330                 }
2331         }
2332
2333         /* If the user really knows what they are doing they can override */
2334         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2335                 if (ctx->cache_ro)
2336                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2337                 else if (ctx->cache_rw)
2338                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2339         }
2340
2341         if (ctx->no_lease) {
2342                 if (ses->server->vals->protocol_id == 0) {
2343                         cifs_dbg(VFS,
2344                                 "SMB2 or later required for nolease option\n");
2345                         rc = -EOPNOTSUPP;
2346                         goto out_fail;
2347                 } else
2348                         tcon->no_lease = ctx->no_lease;
2349         }
2350
2351         /*
2352          * We can have only one retry value for a connection to a share so for
2353          * resources mounted more than once to the same server share the last
2354          * value passed in for the retry flag is used.
2355          */
2356         tcon->retry = ctx->retry;
2357         tcon->nocase = ctx->nocase;
2358         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2359                 tcon->nohandlecache = ctx->nohandlecache;
2360         else
2361                 tcon->nohandlecache = true;
2362         tcon->nodelete = ctx->nodelete;
2363         tcon->local_lease = ctx->local_lease;
2364         INIT_LIST_HEAD(&tcon->pending_opens);
2365
2366         spin_lock(&cifs_tcp_ses_lock);
2367         list_add(&tcon->tcon_list, &ses->tcon_list);
2368         spin_unlock(&cifs_tcp_ses_lock);
2369
2370         cifs_fscache_get_super_cookie(tcon);
2371
2372         return tcon;
2373
2374 out_fail:
2375         tconInfoFree(tcon);
2376         return ERR_PTR(rc);
2377 }
2378
2379 void
2380 cifs_put_tlink(struct tcon_link *tlink)
2381 {
2382         if (!tlink || IS_ERR(tlink))
2383                 return;
2384
2385         if (!atomic_dec_and_test(&tlink->tl_count) ||
2386             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2387                 tlink->tl_time = jiffies;
2388                 return;
2389         }
2390
2391         if (!IS_ERR(tlink_tcon(tlink)))
2392                 cifs_put_tcon(tlink_tcon(tlink));
2393         kfree(tlink);
2394         return;
2395 }
2396
2397 static int
2398 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2399 {
2400         struct cifs_sb_info *old = CIFS_SB(sb);
2401         struct cifs_sb_info *new = mnt_data->cifs_sb;
2402         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2403         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2404
2405         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2406                 return 0;
2407
2408         if (old->mnt_cifs_serverino_autodisabled)
2409                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2410
2411         if (oldflags != newflags)
2412                 return 0;
2413
2414         /*
2415          * We want to share sb only if we don't specify an r/wsize or
2416          * specified r/wsize is greater than or equal to existing one.
2417          */
2418         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2419                 return 0;
2420
2421         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2422                 return 0;
2423
2424         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2425             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2426                 return 0;
2427
2428         if (old->ctx->file_mode != new->ctx->file_mode ||
2429             old->ctx->dir_mode != new->ctx->dir_mode)
2430                 return 0;
2431
2432         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2433                 return 0;
2434
2435         if (old->ctx->acregmax != new->ctx->acregmax)
2436                 return 0;
2437         if (old->ctx->acdirmax != new->ctx->acdirmax)
2438                 return 0;
2439         if (old->ctx->closetimeo != new->ctx->closetimeo)
2440                 return 0;
2441
2442         return 1;
2443 }
2444
2445 static int
2446 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2447 {
2448         struct cifs_sb_info *old = CIFS_SB(sb);
2449         struct cifs_sb_info *new = mnt_data->cifs_sb;
2450         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2451                 old->prepath;
2452         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2453                 new->prepath;
2454
2455         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2456                 return 1;
2457         else if (!old_set && !new_set)
2458                 return 1;
2459
2460         return 0;
2461 }
2462
2463 int
2464 cifs_match_super(struct super_block *sb, void *data)
2465 {
2466         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2467         struct smb3_fs_context *ctx;
2468         struct cifs_sb_info *cifs_sb;
2469         struct TCP_Server_Info *tcp_srv;
2470         struct cifs_ses *ses;
2471         struct cifs_tcon *tcon;
2472         struct tcon_link *tlink;
2473         int rc = 0;
2474
2475         spin_lock(&cifs_tcp_ses_lock);
2476         cifs_sb = CIFS_SB(sb);
2477
2478         /* We do not want to use a superblock that has been shutdown */
2479         if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
2480                 spin_unlock(&cifs_tcp_ses_lock);
2481                 return 0;
2482         }
2483
2484         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2485         if (tlink == NULL) {
2486                 /* can not match superblock if tlink were ever null */
2487                 spin_unlock(&cifs_tcp_ses_lock);
2488                 return 0;
2489         }
2490         tcon = tlink_tcon(tlink);
2491         ses = tcon->ses;
2492         tcp_srv = ses->server;
2493
2494         ctx = mnt_data->ctx;
2495
2496         if (!match_server(tcp_srv, ctx) ||
2497             !match_session(ses, ctx) ||
2498             !match_tcon(tcon, ctx) ||
2499             !match_prepath(sb, mnt_data)) {
2500                 rc = 0;
2501                 goto out;
2502         }
2503
2504         rc = compare_mount_options(sb, mnt_data);
2505 out:
2506         spin_unlock(&cifs_tcp_ses_lock);
2507         cifs_put_tlink(tlink);
2508         return rc;
2509 }
2510
2511 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2512 static struct lock_class_key cifs_key[2];
2513 static struct lock_class_key cifs_slock_key[2];
2514
2515 static inline void
2516 cifs_reclassify_socket4(struct socket *sock)
2517 {
2518         struct sock *sk = sock->sk;
2519         BUG_ON(!sock_allow_reclassification(sk));
2520         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2521                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2522 }
2523
2524 static inline void
2525 cifs_reclassify_socket6(struct socket *sock)
2526 {
2527         struct sock *sk = sock->sk;
2528         BUG_ON(!sock_allow_reclassification(sk));
2529         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2530                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2531 }
2532 #else
2533 static inline void
2534 cifs_reclassify_socket4(struct socket *sock)
2535 {
2536 }
2537
2538 static inline void
2539 cifs_reclassify_socket6(struct socket *sock)
2540 {
2541 }
2542 #endif
2543
2544 /* See RFC1001 section 14 on representation of Netbios names */
2545 static void rfc1002mangle(char *target, char *source, unsigned int length)
2546 {
2547         unsigned int i, j;
2548
2549         for (i = 0, j = 0; i < (length); i++) {
2550                 /* mask a nibble at a time and encode */
2551                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2552                 target[j+1] = 'A' + (0x0F & source[i]);
2553                 j += 2;
2554         }
2555
2556 }
2557
2558 static int
2559 bind_socket(struct TCP_Server_Info *server)
2560 {
2561         int rc = 0;
2562         if (server->srcaddr.ss_family != AF_UNSPEC) {
2563                 /* Bind to the specified local IP address */
2564                 struct socket *socket = server->ssocket;
2565                 rc = socket->ops->bind(socket,
2566                                        (struct sockaddr *) &server->srcaddr,
2567                                        sizeof(server->srcaddr));
2568                 if (rc < 0) {
2569                         struct sockaddr_in *saddr4;
2570                         struct sockaddr_in6 *saddr6;
2571                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2572                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2573                         if (saddr6->sin6_family == AF_INET6)
2574                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2575                                          &saddr6->sin6_addr, rc);
2576                         else
2577                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2578                                          &saddr4->sin_addr.s_addr, rc);
2579                 }
2580         }
2581         return rc;
2582 }
2583
2584 static int
2585 ip_rfc1001_connect(struct TCP_Server_Info *server)
2586 {
2587         int rc = 0;
2588         /*
2589          * some servers require RFC1001 sessinit before sending
2590          * negprot - BB check reconnection in case where second
2591          * sessinit is sent but no second negprot
2592          */
2593         struct rfc1002_session_packet *ses_init_buf;
2594         struct smb_hdr *smb_buf;
2595         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2596                                GFP_KERNEL);
2597         if (ses_init_buf) {
2598                 ses_init_buf->trailer.session_req.called_len = 32;
2599
2600                 if (server->server_RFC1001_name[0] != 0)
2601                         rfc1002mangle(ses_init_buf->trailer.
2602                                       session_req.called_name,
2603                                       server->server_RFC1001_name,
2604                                       RFC1001_NAME_LEN_WITH_NULL);
2605                 else
2606                         rfc1002mangle(ses_init_buf->trailer.
2607                                       session_req.called_name,
2608                                       DEFAULT_CIFS_CALLED_NAME,
2609                                       RFC1001_NAME_LEN_WITH_NULL);
2610
2611                 ses_init_buf->trailer.session_req.calling_len = 32;
2612
2613                 /*
2614                  * calling name ends in null (byte 16) from old smb
2615                  * convention.
2616                  */
2617                 if (server->workstation_RFC1001_name[0] != 0)
2618                         rfc1002mangle(ses_init_buf->trailer.
2619                                       session_req.calling_name,
2620                                       server->workstation_RFC1001_name,
2621                                       RFC1001_NAME_LEN_WITH_NULL);
2622                 else
2623                         rfc1002mangle(ses_init_buf->trailer.
2624                                       session_req.calling_name,
2625                                       "LINUX_CIFS_CLNT",
2626                                       RFC1001_NAME_LEN_WITH_NULL);
2627
2628                 ses_init_buf->trailer.session_req.scope1 = 0;
2629                 ses_init_buf->trailer.session_req.scope2 = 0;
2630                 smb_buf = (struct smb_hdr *)ses_init_buf;
2631
2632                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2633                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2634                 rc = smb_send(server, smb_buf, 0x44);
2635                 kfree(ses_init_buf);
2636                 /*
2637                  * RFC1001 layer in at least one server
2638                  * requires very short break before negprot
2639                  * presumably because not expecting negprot
2640                  * to follow so fast.  This is a simple
2641                  * solution that works without
2642                  * complicating the code and causes no
2643                  * significant slowing down on mount
2644                  * for everyone else
2645                  */
2646                 usleep_range(1000, 2000);
2647         }
2648         /*
2649          * else the negprot may still work without this
2650          * even though malloc failed
2651          */
2652
2653         return rc;
2654 }
2655
2656 static int
2657 generic_ip_connect(struct TCP_Server_Info *server)
2658 {
2659         int rc = 0;
2660         __be16 sport;
2661         int slen, sfamily;
2662         struct socket *socket = server->ssocket;
2663         struct sockaddr *saddr;
2664
2665         saddr = (struct sockaddr *) &server->dstaddr;
2666
2667         if (server->dstaddr.ss_family == AF_INET6) {
2668                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2669
2670                 sport = ipv6->sin6_port;
2671                 slen = sizeof(struct sockaddr_in6);
2672                 sfamily = AF_INET6;
2673                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2674                                 ntohs(sport));
2675         } else {
2676                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2677
2678                 sport = ipv4->sin_port;
2679                 slen = sizeof(struct sockaddr_in);
2680                 sfamily = AF_INET;
2681                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2682                                 ntohs(sport));
2683         }
2684
2685         if (socket == NULL) {
2686                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2687                                    IPPROTO_TCP, &socket, 1);
2688                 if (rc < 0) {
2689                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2690                         server->ssocket = NULL;
2691                         return rc;
2692                 }
2693
2694                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2695                 cifs_dbg(FYI, "Socket created\n");
2696                 server->ssocket = socket;
2697                 socket->sk->sk_allocation = GFP_NOFS;
2698                 if (sfamily == AF_INET6)
2699                         cifs_reclassify_socket6(socket);
2700                 else
2701                         cifs_reclassify_socket4(socket);
2702         }
2703
2704         rc = bind_socket(server);
2705         if (rc < 0)
2706                 return rc;
2707
2708         /*
2709          * Eventually check for other socket options to change from
2710          * the default. sock_setsockopt not used because it expects
2711          * user space buffer
2712          */
2713         socket->sk->sk_rcvtimeo = 7 * HZ;
2714         socket->sk->sk_sndtimeo = 5 * HZ;
2715
2716         /* make the bufsizes depend on wsize/rsize and max requests */
2717         if (server->noautotune) {
2718                 if (socket->sk->sk_sndbuf < (200 * 1024))
2719                         socket->sk->sk_sndbuf = 200 * 1024;
2720                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2721                         socket->sk->sk_rcvbuf = 140 * 1024;
2722         }
2723
2724         if (server->tcp_nodelay)
2725                 tcp_sock_set_nodelay(socket->sk);
2726
2727         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2728                  socket->sk->sk_sndbuf,
2729                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2730
2731         rc = socket->ops->connect(socket, saddr, slen,
2732                                   server->noblockcnt ? O_NONBLOCK : 0);
2733         /*
2734          * When mounting SMB root file systems, we do not want to block in
2735          * connect. Otherwise bail out and then let cifs_reconnect() perform
2736          * reconnect failover - if possible.
2737          */
2738         if (server->noblockcnt && rc == -EINPROGRESS)
2739                 rc = 0;
2740         if (rc < 0) {
2741                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2742                 sock_release(socket);
2743                 server->ssocket = NULL;
2744                 return rc;
2745         }
2746
2747         if (sport == htons(RFC1001_PORT))
2748                 rc = ip_rfc1001_connect(server);
2749
2750         return rc;
2751 }
2752
2753 static int
2754 ip_connect(struct TCP_Server_Info *server)
2755 {
2756         __be16 *sport;
2757         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2758         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2759
2760         if (server->dstaddr.ss_family == AF_INET6)
2761                 sport = &addr6->sin6_port;
2762         else
2763                 sport = &addr->sin_port;
2764
2765         if (*sport == 0) {
2766                 int rc;
2767
2768                 /* try with 445 port at first */
2769                 *sport = htons(CIFS_PORT);
2770
2771                 rc = generic_ip_connect(server);
2772                 if (rc >= 0)
2773                         return rc;
2774
2775                 /* if it failed, try with 139 port */
2776                 *sport = htons(RFC1001_PORT);
2777         }
2778
2779         return generic_ip_connect(server);
2780 }
2781
2782 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2783                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2784 {
2785         /*
2786          * If we are reconnecting then should we check to see if
2787          * any requested capabilities changed locally e.g. via
2788          * remount but we can not do much about it here
2789          * if they have (even if we could detect it by the following)
2790          * Perhaps we could add a backpointer to array of sb from tcon
2791          * or if we change to make all sb to same share the same
2792          * sb as NFS - then we only have one backpointer to sb.
2793          * What if we wanted to mount the server share twice once with
2794          * and once without posixacls or posix paths?
2795          */
2796         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2797
2798         if (ctx && ctx->no_linux_ext) {
2799                 tcon->fsUnixInfo.Capability = 0;
2800                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2801                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2802                 return;
2803         } else if (ctx)
2804                 tcon->unix_ext = 1; /* Unix Extensions supported */
2805
2806         if (!tcon->unix_ext) {
2807                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2808                 return;
2809         }
2810
2811         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2812                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2813                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2814                 /*
2815                  * check for reconnect case in which we do not
2816                  * want to change the mount behavior if we can avoid it
2817                  */
2818                 if (ctx == NULL) {
2819                         /*
2820                          * turn off POSIX ACL and PATHNAMES if not set
2821                          * originally at mount time
2822                          */
2823                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2824                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2825                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2826                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2827                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2828                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2829                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2830                                 cifs_dbg(VFS, "possible reconnect error\n");
2831                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2832                         }
2833                 }
2834
2835                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2836                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2837
2838                 cap &= CIFS_UNIX_CAP_MASK;
2839                 if (ctx && ctx->no_psx_acl)
2840                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2841                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2842                         cifs_dbg(FYI, "negotiated posix acl support\n");
2843                         if (cifs_sb)
2844                                 cifs_sb->mnt_cifs_flags |=
2845                                         CIFS_MOUNT_POSIXACL;
2846                 }
2847
2848                 if (ctx && ctx->posix_paths == 0)
2849                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2850                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2851                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2852                         if (cifs_sb)
2853                                 cifs_sb->mnt_cifs_flags |=
2854                                         CIFS_MOUNT_POSIX_PATHS;
2855                 }
2856
2857                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
2858 #ifdef CONFIG_CIFS_DEBUG2
2859                 if (cap & CIFS_UNIX_FCNTL_CAP)
2860                         cifs_dbg(FYI, "FCNTL cap\n");
2861                 if (cap & CIFS_UNIX_EXTATTR_CAP)
2862                         cifs_dbg(FYI, "EXTATTR cap\n");
2863                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2864                         cifs_dbg(FYI, "POSIX path cap\n");
2865                 if (cap & CIFS_UNIX_XATTR_CAP)
2866                         cifs_dbg(FYI, "XATTR cap\n");
2867                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
2868                         cifs_dbg(FYI, "POSIX ACL cap\n");
2869                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
2870                         cifs_dbg(FYI, "very large read cap\n");
2871                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
2872                         cifs_dbg(FYI, "very large write cap\n");
2873                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
2874                         cifs_dbg(FYI, "transport encryption cap\n");
2875                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2876                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
2877 #endif /* CIFS_DEBUG2 */
2878                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
2879                         if (ctx == NULL)
2880                                 cifs_dbg(FYI, "resetting capabilities failed\n");
2881                         else
2882                                 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");
2883
2884                 }
2885         }
2886 }
2887
2888 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
2889 {
2890         struct smb3_fs_context *ctx = cifs_sb->ctx;
2891
2892         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
2893
2894         spin_lock_init(&cifs_sb->tlink_tree_lock);
2895         cifs_sb->tlink_tree = RB_ROOT;
2896
2897         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
2898                  ctx->file_mode, ctx->dir_mode);
2899
2900         /* this is needed for ASCII cp to Unicode converts */
2901         if (ctx->iocharset == NULL) {
2902                 /* load_nls_default cannot return null */
2903                 cifs_sb->local_nls = load_nls_default();
2904         } else {
2905                 cifs_sb->local_nls = load_nls(ctx->iocharset);
2906                 if (cifs_sb->local_nls == NULL) {
2907                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
2908                                  ctx->iocharset);
2909                         return -ELIBACC;
2910                 }
2911         }
2912         ctx->local_nls = cifs_sb->local_nls;
2913
2914         smb3_update_mnt_flags(cifs_sb);
2915
2916         if (ctx->direct_io)
2917                 cifs_dbg(FYI, "mounting share using direct i/o\n");
2918         if (ctx->cache_ro) {
2919                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
2920                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
2921         } else if (ctx->cache_rw) {
2922                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
2923                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
2924                                             CIFS_MOUNT_RW_CACHE);
2925         }
2926
2927         if ((ctx->cifs_acl) && (ctx->dynperm))
2928                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
2929
2930         if (ctx->prepath) {
2931                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
2932                 if (cifs_sb->prepath == NULL)
2933                         return -ENOMEM;
2934                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
2935         }
2936
2937         return 0;
2938 }
2939
2940 /* Release all succeed connections */
2941 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
2942 {
2943         int rc = 0;
2944
2945         if (mnt_ctx->tcon)
2946                 cifs_put_tcon(mnt_ctx->tcon);
2947         else if (mnt_ctx->ses)
2948                 cifs_put_smb_ses(mnt_ctx->ses);
2949         else if (mnt_ctx->server)
2950                 cifs_put_tcp_session(mnt_ctx->server, 0);
2951         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
2952         free_xid(mnt_ctx->xid);
2953 }
2954
2955 /* Get connections for tcp, ses and tcon */
2956 static int mount_get_conns(struct mount_ctx *mnt_ctx)
2957 {
2958         int rc = 0;
2959         struct TCP_Server_Info *server = NULL;
2960         struct cifs_ses *ses = NULL;
2961         struct cifs_tcon *tcon = NULL;
2962         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
2963         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
2964         unsigned int xid;
2965
2966         xid = get_xid();
2967
2968         /* get a reference to a tcp session */
2969         server = cifs_get_tcp_session(ctx);
2970         if (IS_ERR(server)) {
2971                 rc = PTR_ERR(server);
2972                 server = NULL;
2973                 goto out;
2974         }
2975
2976         /* get a reference to a SMB session */
2977         ses = cifs_get_smb_ses(server, ctx);
2978         if (IS_ERR(ses)) {
2979                 rc = PTR_ERR(ses);
2980                 ses = NULL;
2981                 goto out;
2982         }
2983
2984         if ((ctx->persistent == true) && (!(ses->server->capabilities &
2985                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
2986                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
2987                 rc = -EOPNOTSUPP;
2988                 goto out;
2989         }
2990
2991         /* search for existing tcon to this server share */
2992         tcon = cifs_get_tcon(ses, ctx);
2993         if (IS_ERR(tcon)) {
2994                 rc = PTR_ERR(tcon);
2995                 tcon = NULL;
2996                 goto out;
2997         }
2998
2999         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3000         if (tcon->posix_extensions)
3001                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3002
3003         /* tell server which Unix caps we support */
3004         if (cap_unix(tcon->ses)) {
3005                 /*
3006                  * reset of caps checks mount to see if unix extensions disabled
3007                  * for just this mount.
3008                  */
3009                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3010                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3011                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3012                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3013                         rc = -EACCES;
3014                         goto out;
3015                 }
3016         } else
3017                 tcon->unix_ext = 0; /* server does not support them */
3018
3019         /* do not care if a following call succeed - informational */
3020         if (!tcon->pipe && server->ops->qfs_tcon) {
3021                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3022                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3023                         if (tcon->fsDevInfo.DeviceCharacteristics &
3024                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3025                                 cifs_dbg(VFS, "mounted to read only share\n");
3026                         else if ((cifs_sb->mnt_cifs_flags &
3027                                   CIFS_MOUNT_RW_CACHE) == 0)
3028                                 cifs_dbg(VFS, "read only mount of RW share\n");
3029                         /* no need to log a RW mount of a typical RW share */
3030                 }
3031         }
3032
3033         /*
3034          * Clamp the rsize/wsize mount arguments if they are too big for the server
3035          * and set the rsize/wsize to the negotiated values if not passed in by
3036          * the user on mount
3037          */
3038         if ((cifs_sb->ctx->wsize == 0) ||
3039             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3040                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3041         if ((cifs_sb->ctx->rsize == 0) ||
3042             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3043                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3044
3045 out:
3046         mnt_ctx->server = server;
3047         mnt_ctx->ses = ses;
3048         mnt_ctx->tcon = tcon;
3049         mnt_ctx->xid = xid;
3050
3051         return rc;
3052 }
3053
3054 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3055                              struct cifs_tcon *tcon)
3056 {
3057         struct tcon_link *tlink;
3058
3059         /* hang the tcon off of the superblock */
3060         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3061         if (tlink == NULL)
3062                 return -ENOMEM;
3063
3064         tlink->tl_uid = ses->linux_uid;
3065         tlink->tl_tcon = tcon;
3066         tlink->tl_time = jiffies;
3067         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3068         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3069
3070         cifs_sb->master_tlink = tlink;
3071         spin_lock(&cifs_sb->tlink_tree_lock);
3072         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3073         spin_unlock(&cifs_sb->tlink_tree_lock);
3074
3075         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3076                                 TLINK_IDLE_EXPIRE);
3077         return 0;
3078 }
3079
3080 #ifdef CONFIG_CIFS_DFS_UPCALL
3081 /* Get unique dfs connections */
3082 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3083 {
3084         int rc;
3085
3086         mnt_ctx->fs_ctx->nosharesock = true;
3087         rc = mount_get_conns(mnt_ctx);
3088         if (mnt_ctx->server) {
3089                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3090                 spin_lock(&cifs_tcp_ses_lock);
3091                 mnt_ctx->server->is_dfs_conn = true;
3092                 spin_unlock(&cifs_tcp_ses_lock);
3093         }
3094         return rc;
3095 }
3096
3097 /*
3098  * cifs_build_path_to_root returns full path to root when we do not have an
3099  * existing connection (tcon)
3100  */
3101 static char *
3102 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3103                        const struct cifs_sb_info *cifs_sb, bool useppath)
3104 {
3105         char *full_path, *pos;
3106         unsigned int pplen = useppath && ctx->prepath ?
3107                 strlen(ctx->prepath) + 1 : 0;
3108         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3109
3110         if (unc_len > MAX_TREE_SIZE)
3111                 return ERR_PTR(-EINVAL);
3112
3113         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3114         if (full_path == NULL)
3115                 return ERR_PTR(-ENOMEM);
3116
3117         memcpy(full_path, ctx->UNC, unc_len);
3118         pos = full_path + unc_len;
3119
3120         if (pplen) {
3121                 *pos = CIFS_DIR_SEP(cifs_sb);
3122                 memcpy(pos + 1, ctx->prepath, pplen);
3123                 pos += pplen;
3124         }
3125
3126         *pos = '\0'; /* add trailing null */
3127         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3128         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3129         return full_path;
3130 }
3131
3132 /*
3133  * expand_dfs_referral - Update cifs_sb from dfs referral path
3134  *
3135  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3136  * submount.  Otherwise it will be left untouched.
3137  */
3138 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3139                                struct dfs_info3_param *referral)
3140 {
3141         int rc;
3142         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3143         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3144         char *fake_devname = NULL, *mdata = NULL;
3145
3146         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3147                                            &fake_devname);
3148         if (IS_ERR(mdata)) {
3149                 rc = PTR_ERR(mdata);
3150                 mdata = NULL;
3151         } else {
3152                 /*
3153                  * We can not clear out the whole structure since we no longer have an explicit
3154                  * function to parse a mount-string. Instead we need to clear out the individual
3155                  * fields that are no longer valid.
3156                  */
3157                 kfree(ctx->prepath);
3158                 ctx->prepath = NULL;
3159                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3160         }
3161         kfree(fake_devname);
3162         kfree(cifs_sb->ctx->mount_options);
3163         cifs_sb->ctx->mount_options = mdata;
3164
3165         return rc;
3166 }
3167 #endif
3168
3169 /* TODO: all callers to this are broken. We are not parsing mount_options here
3170  * we should pass a clone of the original context?
3171  */
3172 int
3173 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3174 {
3175         int rc;
3176
3177         if (devname) {
3178                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3179                 rc = smb3_parse_devname(devname, ctx);
3180                 if (rc) {
3181                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3182                         return rc;
3183                 }
3184         }
3185
3186         if (mntopts) {
3187                 char *ip;
3188
3189                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3190                 if (rc) {
3191                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3192                         return rc;
3193                 }
3194
3195                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3196                 kfree(ip);
3197                 if (!rc) {
3198                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3199                         return -EINVAL;
3200                 }
3201         }
3202
3203         if (ctx->nullauth) {
3204                 cifs_dbg(FYI, "Anonymous login\n");
3205                 kfree(ctx->username);
3206                 ctx->username = NULL;
3207         } else if (ctx->username) {
3208                 /* BB fixme parse for domain name here */
3209                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3210         } else {
3211                 cifs_dbg(VFS, "No username specified\n");
3212         /* In userspace mount helper we can get user name from alternate
3213            locations such as env variables and files on disk */
3214                 return -EINVAL;
3215         }
3216
3217         return 0;
3218 }
3219
3220 static int
3221 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3222                                         unsigned int xid,
3223                                         struct cifs_tcon *tcon,
3224                                         struct cifs_sb_info *cifs_sb,
3225                                         char *full_path,
3226                                         int added_treename)
3227 {
3228         int rc;
3229         char *s;
3230         char sep, tmp;
3231         int skip = added_treename ? 1 : 0;
3232
3233         sep = CIFS_DIR_SEP(cifs_sb);
3234         s = full_path;
3235
3236         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3237         while (rc == 0) {
3238                 /* skip separators */
3239                 while (*s == sep)
3240                         s++;
3241                 if (!*s)
3242                         break;
3243                 /* next separator */
3244                 while (*s && *s != sep)
3245                         s++;
3246                 /*
3247                  * if the treename is added, we then have to skip the first
3248                  * part within the separators
3249                  */
3250                 if (skip) {
3251                         skip = 0;
3252                         continue;
3253                 }
3254                 /*
3255                  * temporarily null-terminate the path at the end of
3256                  * the current component
3257                  */
3258                 tmp = *s;
3259                 *s = 0;
3260                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3261                                                      full_path);
3262                 *s = tmp;
3263         }
3264         return rc;
3265 }
3266
3267 /*
3268  * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
3269  * otherwise 0.
3270  */
3271 static int is_path_remote(struct mount_ctx *mnt_ctx)
3272 {
3273         int rc;
3274         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3275         struct TCP_Server_Info *server = mnt_ctx->server;
3276         unsigned int xid = mnt_ctx->xid;
3277         struct cifs_tcon *tcon = mnt_ctx->tcon;
3278         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3279         char *full_path;
3280
3281         if (!server->ops->is_path_accessible)
3282                 return -EOPNOTSUPP;
3283
3284         /*
3285          * cifs_build_path_to_root works only when we have a valid tcon
3286          */
3287         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3288                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3289         if (full_path == NULL)
3290                 return -ENOMEM;
3291
3292         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3293
3294         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3295                                              full_path);
3296         if (rc != 0 && rc != -EREMOTE) {
3297                 kfree(full_path);
3298                 return rc;
3299         }
3300
3301         if (rc != -EREMOTE) {
3302                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3303                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3304                 if (rc != 0) {
3305                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3306                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3307                         rc = 0;
3308                 }
3309         }
3310
3311         kfree(full_path);
3312         return rc;
3313 }
3314
3315 #ifdef CONFIG_CIFS_DFS_UPCALL
3316 static void set_root_ses(struct mount_ctx *mnt_ctx)
3317 {
3318         if (mnt_ctx->ses) {
3319                 spin_lock(&cifs_tcp_ses_lock);
3320                 mnt_ctx->ses->ses_count++;
3321                 spin_unlock(&cifs_tcp_ses_lock);
3322                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3323         }
3324         mnt_ctx->root_ses = mnt_ctx->ses;
3325 }
3326
3327 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3328 {
3329         int rc;
3330         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3331         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3332
3333         *isdfs = true;
3334
3335         rc = mount_get_conns(mnt_ctx);
3336         /*
3337          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3338          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3339          *
3340          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3341          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3342          */
3343         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3344             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3345                            ctx->UNC + 1, NULL, root_tl)) {
3346                 if (rc)
3347                         return rc;
3348                 /* Check if it is fully accessible and then mount it */
3349                 rc = is_path_remote(mnt_ctx);
3350                 if (!rc)
3351                         *isdfs = false;
3352                 else if (rc != -EREMOTE)
3353                         return rc;
3354         }
3355         return 0;
3356 }
3357
3358 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3359                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3360 {
3361         int rc;
3362         struct dfs_info3_param ref = {};
3363         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3364         char *oldmnt = cifs_sb->ctx->mount_options;
3365
3366         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3367         if (rc)
3368                 goto out;
3369
3370         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3371         if (rc)
3372                 goto out;
3373
3374         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3375         if (oldmnt != cifs_sb->ctx->mount_options) {
3376                 mount_put_conns(mnt_ctx);
3377                 rc = mount_get_dfs_conns(mnt_ctx);
3378         }
3379         if (!rc) {
3380                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3381                         set_root_ses(mnt_ctx);
3382                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3383                                               cifs_remap(cifs_sb), ref_path, tit);
3384         }
3385
3386 out:
3387         free_dfs_info_param(&ref);
3388         return rc;
3389 }
3390
3391 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3392 {
3393         int rc;
3394         char *full_path;
3395         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3396         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3397         struct dfs_cache_tgt_iterator *tit;
3398
3399         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3400          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3401          * now on.
3402          */
3403         mount_put_conns(mnt_ctx);
3404         mount_get_dfs_conns(mnt_ctx);
3405         set_root_ses(mnt_ctx);
3406
3407         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3408         if (IS_ERR(full_path))
3409                 return PTR_ERR(full_path);
3410
3411         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3412                                                             cifs_remap(cifs_sb));
3413         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3414                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3415                 mnt_ctx->origin_fullpath = NULL;
3416                 goto out;
3417         }
3418
3419         /* Try all dfs root targets */
3420         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3421              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3422                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3423                 if (!rc) {
3424                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3425                         if (!mnt_ctx->leaf_fullpath)
3426                                 rc = -ENOMEM;
3427                         break;
3428                 }
3429         }
3430
3431 out:
3432         kfree(full_path);
3433         return rc;
3434 }
3435
3436 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3437 {
3438         int rc;
3439         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3440         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3441         char *full_path;
3442         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3443         struct dfs_cache_tgt_iterator *tit;
3444
3445         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3446         if (IS_ERR(full_path))
3447                 return PTR_ERR(full_path);
3448
3449         kfree(mnt_ctx->leaf_fullpath);
3450         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3451                                                           cifs_remap(cifs_sb));
3452         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3453                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3454                 mnt_ctx->leaf_fullpath = NULL;
3455                 goto out;
3456         }
3457
3458         /* Get referral from dfs link */
3459         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3460                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3461         if (rc)
3462                 goto out;
3463
3464         /* Try all dfs link targets */
3465         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3466              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3467                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3468                 if (!rc) {
3469                         rc = is_path_remote(mnt_ctx);
3470                         break;
3471                 }
3472         }
3473
3474 out:
3475         kfree(full_path);
3476         dfs_cache_free_tgts(&tl);
3477         return rc;
3478 }
3479
3480 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3481 {
3482         int rc;
3483         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3484         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3485         char *full_path;
3486         int num_links = 0;
3487
3488         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3489         if (IS_ERR(full_path))
3490                 return PTR_ERR(full_path);
3491
3492         kfree(mnt_ctx->origin_fullpath);
3493         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3494                                                             cifs_remap(cifs_sb));
3495         kfree(full_path);
3496
3497         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3498                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3499                 mnt_ctx->origin_fullpath = NULL;
3500                 return rc;
3501         }
3502
3503         do {
3504                 rc = __follow_dfs_link(mnt_ctx);
3505                 if (!rc || rc != -EREMOTE)
3506                         break;
3507         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3508
3509         return rc;
3510 }
3511
3512 /* Set up DFS referral paths for failover */
3513 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3514 {
3515         struct TCP_Server_Info *server = mnt_ctx->server;
3516
3517         server->origin_fullpath = mnt_ctx->origin_fullpath;
3518         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3519         server->current_fullpath = mnt_ctx->leaf_fullpath;
3520         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3521 }
3522
3523 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3524 {
3525         int rc;
3526         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3527         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3528         bool isdfs;
3529
3530         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3531         if (rc)
3532                 goto error;
3533         if (!isdfs)
3534                 goto out;
3535
3536         uuid_gen(&mnt_ctx.mount_id);
3537         rc = connect_dfs_root(&mnt_ctx, &tl);
3538         dfs_cache_free_tgts(&tl);
3539
3540         if (rc)
3541                 goto error;
3542
3543         rc = is_path_remote(&mnt_ctx);
3544         if (rc == -EREMOTE)
3545                 rc = follow_dfs_link(&mnt_ctx);
3546         if (rc)
3547                 goto error;
3548
3549         setup_server_referral_paths(&mnt_ctx);
3550         /*
3551          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3552          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3553          */
3554         cifs_autodisable_serverino(cifs_sb);
3555         /*
3556          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3557          * that have different prefix paths.
3558          */
3559         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3560         kfree(cifs_sb->prepath);
3561         cifs_sb->prepath = ctx->prepath;
3562         ctx->prepath = NULL;
3563         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3564
3565 out:
3566         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3567         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3568         if (rc)
3569                 goto error;
3570
3571         free_xid(mnt_ctx.xid);
3572         return rc;
3573
3574 error:
3575         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3576         kfree(mnt_ctx.origin_fullpath);
3577         kfree(mnt_ctx.leaf_fullpath);
3578         mount_put_conns(&mnt_ctx);
3579         return rc;
3580 }
3581 #else
3582 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3583 {
3584         int rc = 0;
3585         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3586
3587         rc = mount_get_conns(&mnt_ctx);
3588         if (rc)
3589                 goto error;
3590
3591         if (mnt_ctx.tcon) {
3592                 rc = is_path_remote(&mnt_ctx);
3593                 if (rc == -EREMOTE)
3594                         rc = -EOPNOTSUPP;
3595                 if (rc)
3596                         goto error;
3597         }
3598
3599         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3600         if (rc)
3601                 goto error;
3602
3603         free_xid(mnt_ctx.xid);
3604         return rc;
3605
3606 error:
3607         mount_put_conns(&mnt_ctx);
3608         return rc;
3609 }
3610 #endif
3611
3612 /*
3613  * Issue a TREE_CONNECT request.
3614  */
3615 int
3616 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3617          const char *tree, struct cifs_tcon *tcon,
3618          const struct nls_table *nls_codepage)
3619 {
3620         struct smb_hdr *smb_buffer;
3621         struct smb_hdr *smb_buffer_response;
3622         TCONX_REQ *pSMB;
3623         TCONX_RSP *pSMBr;
3624         unsigned char *bcc_ptr;
3625         int rc = 0;
3626         int length;
3627         __u16 bytes_left, count;
3628
3629         if (ses == NULL)
3630                 return -EIO;
3631
3632         smb_buffer = cifs_buf_get();
3633         if (smb_buffer == NULL)
3634                 return -ENOMEM;
3635
3636         smb_buffer_response = smb_buffer;
3637
3638         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3639                         NULL /*no tid */ , 4 /*wct */ );
3640
3641         smb_buffer->Mid = get_next_mid(ses->server);
3642         smb_buffer->Uid = ses->Suid;
3643         pSMB = (TCONX_REQ *) smb_buffer;
3644         pSMBr = (TCONX_RSP *) smb_buffer_response;
3645
3646         pSMB->AndXCommand = 0xFF;
3647         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3648         bcc_ptr = &pSMB->Password[0];
3649
3650         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3651         *bcc_ptr = 0; /* password is null byte */
3652         bcc_ptr++;              /* skip password */
3653         /* already aligned so no need to do it below */
3654
3655         if (ses->server->sign)
3656                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3657
3658         if (ses->capabilities & CAP_STATUS32) {
3659                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3660         }
3661         if (ses->capabilities & CAP_DFS) {
3662                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3663         }
3664         if (ses->capabilities & CAP_UNICODE) {
3665                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3666                 length =
3667                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3668                         6 /* max utf8 char length in bytes */ *
3669                         (/* server len*/ + 256 /* share len */), nls_codepage);
3670                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3671                 bcc_ptr += 2;   /* skip trailing null */
3672         } else {                /* ASCII */
3673                 strcpy(bcc_ptr, tree);
3674                 bcc_ptr += strlen(tree) + 1;
3675         }
3676         strcpy(bcc_ptr, "?????");
3677         bcc_ptr += strlen("?????");
3678         bcc_ptr += 1;
3679         count = bcc_ptr - &pSMB->Password[0];
3680         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3681         pSMB->ByteCount = cpu_to_le16(count);
3682
3683         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3684                          0);
3685
3686         /* above now done in SendReceive */
3687         if (rc == 0) {
3688                 bool is_unicode;
3689
3690                 tcon->tidStatus = CifsGood;
3691                 tcon->need_reconnect = false;
3692                 tcon->tid = smb_buffer_response->Tid;
3693                 bcc_ptr = pByteArea(smb_buffer_response);
3694                 bytes_left = get_bcc(smb_buffer_response);
3695                 length = strnlen(bcc_ptr, bytes_left - 2);
3696                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3697                         is_unicode = true;
3698                 else
3699                         is_unicode = false;
3700
3701
3702                 /* skip service field (NB: this field is always ASCII) */
3703                 if (length == 3) {
3704                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3705                             (bcc_ptr[2] == 'C')) {
3706                                 cifs_dbg(FYI, "IPC connection\n");
3707                                 tcon->ipc = true;
3708                                 tcon->pipe = true;
3709                         }
3710                 } else if (length == 2) {
3711                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3712                                 /* the most common case */
3713                                 cifs_dbg(FYI, "disk share connection\n");
3714                         }
3715                 }
3716                 bcc_ptr += length + 1;
3717                 bytes_left -= (length + 1);
3718                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3719
3720                 /* mostly informational -- no need to fail on error here */
3721                 kfree(tcon->nativeFileSystem);
3722                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3723                                                       bytes_left, is_unicode,
3724                                                       nls_codepage);
3725
3726                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3727
3728                 if ((smb_buffer_response->WordCount == 3) ||
3729                          (smb_buffer_response->WordCount == 7))
3730                         /* field is in same location */
3731                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3732                 else
3733                         tcon->Flags = 0;
3734                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3735         }
3736
3737         cifs_buf_release(smb_buffer);
3738         return rc;
3739 }
3740
3741 static void delayed_free(struct rcu_head *p)
3742 {
3743         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3744
3745         unload_nls(cifs_sb->local_nls);
3746         smb3_cleanup_fs_context(cifs_sb->ctx);
3747         kfree(cifs_sb);
3748 }
3749
3750 void
3751 cifs_umount(struct cifs_sb_info *cifs_sb)
3752 {
3753         struct rb_root *root = &cifs_sb->tlink_tree;
3754         struct rb_node *node;
3755         struct tcon_link *tlink;
3756
3757         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3758
3759         spin_lock(&cifs_sb->tlink_tree_lock);
3760         while ((node = rb_first(root))) {
3761                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3762                 cifs_get_tlink(tlink);
3763                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3764                 rb_erase(node, root);
3765
3766                 spin_unlock(&cifs_sb->tlink_tree_lock);
3767                 cifs_put_tlink(tlink);
3768                 spin_lock(&cifs_sb->tlink_tree_lock);
3769         }
3770         spin_unlock(&cifs_sb->tlink_tree_lock);
3771
3772         kfree(cifs_sb->prepath);
3773 #ifdef CONFIG_CIFS_DFS_UPCALL
3774         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3775 #endif
3776         call_rcu(&cifs_sb->rcu, delayed_free);
3777 }
3778
3779 int
3780 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses)
3781 {
3782         int rc = 0;
3783         struct TCP_Server_Info *server = cifs_ses_server(ses);
3784
3785         if (!server->ops->need_neg || !server->ops->negotiate)
3786                 return -ENOSYS;
3787
3788         /* only send once per connect */
3789         if (!server->ops->need_neg(server))
3790                 return 0;
3791
3792         rc = server->ops->negotiate(xid, ses);
3793         if (rc == 0) {
3794                 spin_lock(&GlobalMid_Lock);
3795                 if (server->tcpStatus == CifsNeedNegotiate)
3796                         server->tcpStatus = CifsGood;
3797                 else
3798                         rc = -EHOSTDOWN;
3799                 spin_unlock(&GlobalMid_Lock);
3800         }
3801
3802         return rc;
3803 }
3804
3805 int
3806 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3807                    struct nls_table *nls_info)
3808 {
3809         int rc = -ENOSYS;
3810         struct TCP_Server_Info *server = cifs_ses_server(ses);
3811
3812         if (!ses->binding) {
3813                 ses->capabilities = server->capabilities;
3814                 if (!linuxExtEnabled)
3815                         ses->capabilities &= (~server->vals->cap_unix);
3816
3817                 if (ses->auth_key.response) {
3818                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3819                                  ses->auth_key.response);
3820                         kfree(ses->auth_key.response);
3821                         ses->auth_key.response = NULL;
3822                         ses->auth_key.len = 0;
3823                 }
3824         }
3825
3826         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3827                  server->sec_mode, server->capabilities, server->timeAdj);
3828
3829         if (server->ops->sess_setup)
3830                 rc = server->ops->sess_setup(xid, ses, nls_info);
3831
3832         if (rc)
3833                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3834
3835         return rc;
3836 }
3837
3838 static int
3839 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3840 {
3841         ctx->sectype = ses->sectype;
3842
3843         /* krb5 is special, since we don't need username or pw */
3844         if (ctx->sectype == Kerberos)
3845                 return 0;
3846
3847         return cifs_set_cifscreds(ctx, ses);
3848 }
3849
3850 static struct cifs_tcon *
3851 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3852 {
3853         int rc;
3854         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3855         struct cifs_ses *ses;
3856         struct cifs_tcon *tcon = NULL;
3857         struct smb3_fs_context *ctx;
3858
3859         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3860         if (ctx == NULL)
3861                 return ERR_PTR(-ENOMEM);
3862
3863         ctx->local_nls = cifs_sb->local_nls;
3864         ctx->linux_uid = fsuid;
3865         ctx->cred_uid = fsuid;
3866         ctx->UNC = master_tcon->treeName;
3867         ctx->retry = master_tcon->retry;
3868         ctx->nocase = master_tcon->nocase;
3869         ctx->nohandlecache = master_tcon->nohandlecache;
3870         ctx->local_lease = master_tcon->local_lease;
3871         ctx->no_lease = master_tcon->no_lease;
3872         ctx->resilient = master_tcon->use_resilient;
3873         ctx->persistent = master_tcon->use_persistent;
3874         ctx->handle_timeout = master_tcon->handle_timeout;
3875         ctx->no_linux_ext = !master_tcon->unix_ext;
3876         ctx->linux_ext = master_tcon->posix_extensions;
3877         ctx->sectype = master_tcon->ses->sectype;
3878         ctx->sign = master_tcon->ses->sign;
3879         ctx->seal = master_tcon->seal;
3880         ctx->witness = master_tcon->use_witness;
3881
3882         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3883         if (rc) {
3884                 tcon = ERR_PTR(rc);
3885                 goto out;
3886         }
3887
3888         /* get a reference for the same TCP session */
3889         spin_lock(&cifs_tcp_ses_lock);
3890         ++master_tcon->ses->server->srv_count;
3891         spin_unlock(&cifs_tcp_ses_lock);
3892
3893         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3894         if (IS_ERR(ses)) {
3895                 tcon = (struct cifs_tcon *)ses;
3896                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3897                 goto out;
3898         }
3899
3900         tcon = cifs_get_tcon(ses, ctx);
3901         if (IS_ERR(tcon)) {
3902                 cifs_put_smb_ses(ses);
3903                 goto out;
3904         }
3905
3906         if (cap_unix(ses))
3907                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3908
3909 out:
3910         kfree(ctx->username);
3911         kfree_sensitive(ctx->password);
3912         kfree(ctx);
3913
3914         return tcon;
3915 }
3916
3917 struct cifs_tcon *
3918 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3919 {
3920         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3921 }
3922
3923 /* find and return a tlink with given uid */
3924 static struct tcon_link *
3925 tlink_rb_search(struct rb_root *root, kuid_t uid)
3926 {
3927         struct rb_node *node = root->rb_node;
3928         struct tcon_link *tlink;
3929
3930         while (node) {
3931                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3932
3933                 if (uid_gt(tlink->tl_uid, uid))
3934                         node = node->rb_left;
3935                 else if (uid_lt(tlink->tl_uid, uid))
3936                         node = node->rb_right;
3937                 else
3938                         return tlink;
3939         }
3940         return NULL;
3941 }
3942
3943 /* insert a tcon_link into the tree */
3944 static void
3945 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3946 {
3947         struct rb_node **new = &(root->rb_node), *parent = NULL;
3948         struct tcon_link *tlink;
3949
3950         while (*new) {
3951                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3952                 parent = *new;
3953
3954                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3955                         new = &((*new)->rb_left);
3956                 else
3957                         new = &((*new)->rb_right);
3958         }
3959
3960         rb_link_node(&new_tlink->tl_rbnode, parent, new);
3961         rb_insert_color(&new_tlink->tl_rbnode, root);
3962 }
3963
3964 /*
3965  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3966  * current task.
3967  *
3968  * If the superblock doesn't refer to a multiuser mount, then just return
3969  * the master tcon for the mount.
3970  *
3971  * First, search the rbtree for an existing tcon for this fsuid. If one
3972  * exists, then check to see if it's pending construction. If it is then wait
3973  * for construction to complete. Once it's no longer pending, check to see if
3974  * it failed and either return an error or retry construction, depending on
3975  * the timeout.
3976  *
3977  * If one doesn't exist then insert a new tcon_link struct into the tree and
3978  * try to construct a new one.
3979  */
3980 struct tcon_link *
3981 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3982 {
3983         int ret;
3984         kuid_t fsuid = current_fsuid();
3985         struct tcon_link *tlink, *newtlink;
3986
3987         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3988                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3989
3990         spin_lock(&cifs_sb->tlink_tree_lock);
3991         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3992         if (tlink)
3993                 cifs_get_tlink(tlink);
3994         spin_unlock(&cifs_sb->tlink_tree_lock);
3995
3996         if (tlink == NULL) {
3997                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3998                 if (newtlink == NULL)
3999                         return ERR_PTR(-ENOMEM);
4000                 newtlink->tl_uid = fsuid;
4001                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4002                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4003                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4004                 cifs_get_tlink(newtlink);
4005
4006                 spin_lock(&cifs_sb->tlink_tree_lock);
4007                 /* was one inserted after previous search? */
4008                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4009                 if (tlink) {
4010                         cifs_get_tlink(tlink);
4011                         spin_unlock(&cifs_sb->tlink_tree_lock);
4012                         kfree(newtlink);
4013                         goto wait_for_construction;
4014                 }
4015                 tlink = newtlink;
4016                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4017                 spin_unlock(&cifs_sb->tlink_tree_lock);
4018         } else {
4019 wait_for_construction:
4020                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4021                                   TASK_INTERRUPTIBLE);
4022                 if (ret) {
4023                         cifs_put_tlink(tlink);
4024                         return ERR_PTR(-ERESTARTSYS);
4025                 }
4026
4027                 /* if it's good, return it */
4028                 if (!IS_ERR(tlink->tl_tcon))
4029                         return tlink;
4030
4031                 /* return error if we tried this already recently */
4032                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4033                         cifs_put_tlink(tlink);
4034                         return ERR_PTR(-EACCES);
4035                 }
4036
4037                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4038                         goto wait_for_construction;
4039         }
4040
4041         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4042         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4043         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4044
4045         if (IS_ERR(tlink->tl_tcon)) {
4046                 cifs_put_tlink(tlink);
4047                 return ERR_PTR(-EACCES);
4048         }
4049
4050         return tlink;
4051 }
4052
4053 /*
4054  * periodic workqueue job that scans tcon_tree for a superblock and closes
4055  * out tcons.
4056  */
4057 static void
4058 cifs_prune_tlinks(struct work_struct *work)
4059 {
4060         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4061                                                     prune_tlinks.work);
4062         struct rb_root *root = &cifs_sb->tlink_tree;
4063         struct rb_node *node;
4064         struct rb_node *tmp;
4065         struct tcon_link *tlink;
4066
4067         /*
4068          * Because we drop the spinlock in the loop in order to put the tlink
4069          * it's not guarded against removal of links from the tree. The only
4070          * places that remove entries from the tree are this function and
4071          * umounts. Because this function is non-reentrant and is canceled
4072          * before umount can proceed, this is safe.
4073          */
4074         spin_lock(&cifs_sb->tlink_tree_lock);
4075         node = rb_first(root);
4076         while (node != NULL) {
4077                 tmp = node;
4078                 node = rb_next(tmp);
4079                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4080
4081                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4082                     atomic_read(&tlink->tl_count) != 0 ||
4083                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4084                         continue;
4085
4086                 cifs_get_tlink(tlink);
4087                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4088                 rb_erase(tmp, root);
4089
4090                 spin_unlock(&cifs_sb->tlink_tree_lock);
4091                 cifs_put_tlink(tlink);
4092                 spin_lock(&cifs_sb->tlink_tree_lock);
4093         }
4094         spin_unlock(&cifs_sb->tlink_tree_lock);
4095
4096         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4097                                 TLINK_IDLE_EXPIRE);
4098 }
4099
4100 #ifdef CONFIG_CIFS_DFS_UPCALL
4101 static void mark_tcon_tcp_ses_for_reconnect(struct cifs_tcon *tcon)
4102 {
4103         int i;
4104
4105         for (i = 0; i < tcon->ses->chan_count; i++) {
4106                 spin_lock(&GlobalMid_Lock);
4107                 if (tcon->ses->chans[i].server->tcpStatus != CifsExiting)
4108                         tcon->ses->chans[i].server->tcpStatus = CifsNeedReconnect;
4109                 spin_unlock(&GlobalMid_Lock);
4110         }
4111 }
4112
4113 /* Update dfs referral path of superblock */
4114 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4115                                   const char *target)
4116 {
4117         int rc = 0;
4118         size_t len = strlen(target);
4119         char *refpath, *npath;
4120
4121         if (unlikely(len < 2 || *target != '\\'))
4122                 return -EINVAL;
4123
4124         if (target[1] == '\\') {
4125                 len += 1;
4126                 refpath = kmalloc(len, GFP_KERNEL);
4127                 if (!refpath)
4128                         return -ENOMEM;
4129
4130                 scnprintf(refpath, len, "%s", target);
4131         } else {
4132                 len += sizeof("\\");
4133                 refpath = kmalloc(len, GFP_KERNEL);
4134                 if (!refpath)
4135                         return -ENOMEM;
4136
4137                 scnprintf(refpath, len, "\\%s", target);
4138         }
4139
4140         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4141         kfree(refpath);
4142
4143         if (IS_ERR(npath)) {
4144                 rc = PTR_ERR(npath);
4145         } else {
4146                 mutex_lock(&server->refpath_lock);
4147                 kfree(server->leaf_fullpath);
4148                 server->leaf_fullpath = npath;
4149                 mutex_unlock(&server->refpath_lock);
4150                 server->current_fullpath = server->leaf_fullpath;
4151         }
4152         return rc;
4153 }
4154
4155 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4156                                        size_t tcp_host_len, char *share, bool *target_match)
4157 {
4158         int rc = 0;
4159         const char *dfs_host;
4160         size_t dfs_host_len;
4161
4162         *target_match = true;
4163         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4164
4165         /* Check if hostnames or addresses match */
4166         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4167                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4168                          dfs_host, (int)tcp_host_len, tcp_host);
4169                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4170                 if (rc)
4171                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4172         }
4173         return rc;
4174 }
4175
4176 int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4177                               struct cifs_sb_info *cifs_sb, char *tree,
4178                               struct dfs_cache_tgt_list *tl, struct dfs_info3_param *ref)
4179 {
4180         int rc;
4181         struct TCP_Server_Info *server = tcon->ses->server;
4182         const struct smb_version_operations *ops = server->ops;
4183         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4184         bool islink;
4185         char *share = NULL, *prefix = NULL;
4186         const char *tcp_host;
4187         size_t tcp_host_len;
4188         struct dfs_cache_tgt_iterator *tit;
4189         bool target_match;
4190
4191         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4192
4193         islink = ref->server_type == DFS_TYPE_LINK;
4194         free_dfs_info_param(ref);
4195
4196         tit = dfs_cache_get_tgt_iterator(tl);
4197         if (!tit) {
4198                 rc = -ENOENT;
4199                 goto out;
4200         }
4201
4202         /* Try to tree connect to all dfs targets */
4203         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4204                 const char *target = dfs_cache_get_tgt_name(tit);
4205                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4206
4207                 kfree(share);
4208                 kfree(prefix);
4209
4210                 /* Check if share matches with tcp ses */
4211                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4212                 if (rc) {
4213                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4214                         break;
4215                 }
4216
4217                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4218                                                  &target_match);
4219                 if (rc)
4220                         break;
4221                 if (!target_match) {
4222                         rc = -EHOSTUNREACH;
4223                         continue;
4224                 }
4225
4226                 if (ipc->need_reconnect) {
4227                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4228                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4229                         if (rc)
4230                                 break;
4231                 }
4232
4233                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4234                 if (!islink) {
4235                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4236                         break;
4237                 }
4238                 /*
4239                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4240                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4241                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4242                  * newly resolved target.
4243                  */
4244                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4245                                    ref, &ntl)) {
4246                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4247                         if (rc)
4248                                 continue;
4249                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4250                         if (!rc)
4251                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4252                         break;
4253                 }
4254                 /* Target is another dfs share */
4255                 rc = update_server_fullpath(server, cifs_sb, target);
4256                 dfs_cache_free_tgts(tl);
4257
4258                 if (!rc) {
4259                         rc = -EREMOTE;
4260                         list_replace_init(&ntl.tl_list, &tl->tl_list);
4261                 } else {
4262                         dfs_cache_free_tgts(&ntl);
4263                         free_dfs_info_param(ref);
4264                 }
4265                 break;
4266         }
4267
4268 out:
4269         kfree(share);
4270         kfree(prefix);
4271
4272         return rc;
4273 }
4274
4275 int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4276                             struct cifs_sb_info *cifs_sb, char *tree,
4277                             struct dfs_cache_tgt_list *tl, struct dfs_info3_param *ref)
4278 {
4279         int rc;
4280         int num_links = 0;
4281         struct TCP_Server_Info *server = tcon->ses->server;
4282
4283         do {
4284                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, tl, ref);
4285                 if (!rc || rc != -EREMOTE)
4286                         break;
4287         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4288         /*
4289          * If we couldn't tree connect to any targets from last referral path, then retry from
4290          * original referral path.
4291          */
4292         if (rc && server->current_fullpath != server->origin_fullpath) {
4293                 server->current_fullpath = server->origin_fullpath;
4294                 mark_tcon_tcp_ses_for_reconnect(tcon);
4295         }
4296
4297         dfs_cache_free_tgts(tl);
4298         return rc;
4299 }
4300
4301 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4302 {
4303         int rc;
4304         struct TCP_Server_Info *server = tcon->ses->server;
4305         const struct smb_version_operations *ops = server->ops;
4306         struct super_block *sb = NULL;
4307         struct cifs_sb_info *cifs_sb;
4308         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4309         char *tree;
4310         struct dfs_info3_param ref = {0};
4311
4312         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4313         if (!tree)
4314                 return -ENOMEM;
4315
4316         if (tcon->ipc) {
4317                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4318                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4319                 goto out;
4320         }
4321
4322         sb = cifs_get_tcp_super(server);
4323         if (IS_ERR(sb)) {
4324                 rc = PTR_ERR(sb);
4325                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4326                 goto out;
4327         }
4328
4329         cifs_sb = CIFS_SB(sb);
4330
4331         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4332         if (!server->current_fullpath ||
4333             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4334                 rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls);
4335                 goto out;
4336         }
4337
4338         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, &tl, &ref);
4339
4340 out:
4341         kfree(tree);
4342         cifs_put_tcp_super(sb);
4343
4344         return rc;
4345 }
4346 #else
4347 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4348 {
4349         const struct smb_version_operations *ops = tcon->ses->server->ops;
4350
4351         return ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4352 }
4353 #endif