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 ([email protected])
   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  * Update the tcpStatus for the server.
 167  * This is used to signal the cifsd thread to call cifs_reconnect
 168  * ONLY cifsd thread should call cifs_reconnect. For any other
 169  * thread, use this function
 170  *
 171  * @server: the tcp ses for which reconnect is needed
 172  * @all_channels: if this needs to be done for all channels
 173  */
 174 void
 175 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 176                                 bool all_channels)
 177 {
 178         struct TCP_Server_Info *pserver;
 179         struct cifs_ses *ses;
 180         int i;
 181
 182         /* If server is a channel, select the primary channel */
 183         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 184
 185         spin_lock(&cifs_tcp_ses_lock);
 186         if (!all_channels) {
 187                 pserver->tcpStatus = CifsNeedReconnect;
 188                 spin_unlock(&cifs_tcp_ses_lock);
 189                 return;
 190         }
 191
 192         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 193                 spin_lock(&ses->chan_lock);
 194                 for (i = 0; i < ses->chan_count; i++)
 195                         ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 196                 spin_unlock(&ses->chan_lock);
 197         }
 198         spin_unlock(&cifs_tcp_ses_lock);
 199 }
 200
 201 /*
 202  * Mark all sessions and tcons for reconnect.
 203  * IMPORTANT: make sure that this gets called only from
 204  * cifsd thread. For any other thread, use
 205  * cifs_signal_cifsd_for_reconnect
 206  *
 207  * @server: the tcp ses for which reconnect is needed
 208  * @server needs to be previously set to CifsNeedReconnect.
 209  * @mark_smb_session: whether even sessions need to be marked
 210  */
 211 void
 212 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 213                                       bool mark_smb_session)
 214 {
 215         struct TCP_Server_Info *pserver;
 216         struct cifs_ses *ses;
 217         struct cifs_tcon *tcon;
 218
 219         /*
 220          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 221          * are not used until reconnected.
 222          */
 223         cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 224
 225         /* If server is a channel, select the primary channel */
 226         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 227
 228
 229         spin_lock(&cifs_tcp_ses_lock);
 230         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 231                 spin_lock(&ses->chan_lock);
 232                 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
 233                         goto next_session;
 234
 235                 if (mark_smb_session)
 236                         CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 237                 else
 238                         cifs_chan_set_need_reconnect(ses, server);
 239
 240                 /* If all channels need reconnect, then tcon needs reconnect */
 241                 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
 242                         goto next_session;
 243
 244                 ses->status = CifsNeedReconnect;
 245
 246                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 247                         tcon->need_reconnect = true;
 248                         tcon->status = TID_NEED_RECON;
 249                 }
 250                 if (ses->tcon_ipc)
 251                         ses->tcon_ipc->need_reconnect = true;
 252
 253 next_session:
 254                 spin_unlock(&ses->chan_lock);
 255         }
 256         spin_unlock(&cifs_tcp_ses_lock);
 257 }
 258
 259 static void
 260 cifs_abort_connection(struct TCP_Server_Info *server)
 261 {
 262         struct mid_q_entry *mid, *nmid;
 263         struct list_head retry_list;
 264
 265         server->maxBuf = 0;
 266         server->max_read = 0;
 267
 268         /* do not want to be sending data on a socket we are freeing */
 269         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 270         mutex_lock(&server->srv_mutex);
 271         if (server->ssocket) {
 272                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 273                          server->ssocket->flags);
 274                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 275                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 276                          server->ssocket->flags);
 277                 sock_release(server->ssocket);
 278                 server->ssocket = NULL;
 279         }
 280         server->sequence_number = 0;
 281         server->session_estab = false;
 282         kfree(server->session_key.response);
 283         server->session_key.response = NULL;
 284         server->session_key.len = 0;
 285         server->lstrp = jiffies;
 286
 287         /* mark submitted MIDs for retry and issue callback */
 288         INIT_LIST_HEAD(&retry_list);
 289         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 290         spin_lock(&GlobalMid_Lock);
 291         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 292                 kref_get(&mid->refcount);
 293                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 294                         mid->mid_state = MID_RETRY_NEEDED;
 295                 list_move(&mid->qhead, &retry_list);
 296                 mid->mid_flags |= MID_DELETED;
 297         }
 298         spin_unlock(&GlobalMid_Lock);
 299         mutex_unlock(&server->srv_mutex);
 300
 301         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 302         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 303                 list_del_init(&mid->qhead);
 304                 mid->callback(mid);
 305                 cifs_mid_q_entry_release(mid);
 306         }
 307
 308         if (cifs_rdma_enabled(server)) {
 309                 mutex_lock(&server->srv_mutex);
 310                 smbd_destroy(server);
 311                 mutex_unlock(&server->srv_mutex);
 312         }
 313 }
 314
 315 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 316 {
 317         spin_lock(&cifs_tcp_ses_lock);
 318         server->nr_targets = num_targets;
 319         if (server->tcpStatus == CifsExiting) {
 320                 /* the demux thread will exit normally next time through the loop */
 321                 spin_unlock(&cifs_tcp_ses_lock);
 322                 wake_up(&server->response_q);
 323                 return false;
 324         }
 325
 326         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 327         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 328                              server->hostname);
 329         server->tcpStatus = CifsNeedReconnect;
 330
 331         spin_unlock(&cifs_tcp_ses_lock);
 332         return true;
 333 }
 334
 335 /*
 336  * cifs tcp session reconnection
 337  *
 338  * mark tcp session as reconnecting so temporarily locked
 339  * mark all smb sessions as reconnecting for tcp session
 340  * reconnect tcp session
 341  * wake up waiters on reconnection? - (not needed currently)
 342  *
 343  * if mark_smb_session is passed as true, unconditionally mark
 344  * the smb session (and tcon) for reconnect as well. This value
 345  * doesn't really matter for non-multichannel scenario.
 346  *
 347  */
 348 static int __cifs_reconnect(struct TCP_Server_Info *server,
 349                             bool mark_smb_session)
 350 {
 351         int rc = 0;
 352
 353         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 354                 return 0;
 355
 356         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 357
 358         cifs_abort_connection(server);
 359
 360         do {
 361                 try_to_freeze();
 362                 mutex_lock(&server->srv_mutex);
 363
 364                 if (!cifs_swn_set_server_dstaddr(server)) {
 365                         /* resolve the hostname again to make sure that IP address is up-to-date */
 366                         rc = reconn_set_ipaddr_from_hostname(server);
 367                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 368                 }
 369
 370                 if (cifs_rdma_enabled(server))
 371                         rc = smbd_reconnect(server);
 372                 else
 373                         rc = generic_ip_connect(server);
 374                 if (rc) {
 375                         mutex_unlock(&server->srv_mutex);
 376                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 377                         msleep(3000);
 378                 } else {
 379                         atomic_inc(&tcpSesReconnectCount);
 380                         set_credits(server, 1);
 381                         spin_lock(&cifs_tcp_ses_lock);
 382                         if (server->tcpStatus != CifsExiting)
 383                                 server->tcpStatus = CifsNeedNegotiate;
 384                         spin_unlock(&cifs_tcp_ses_lock);
 385                         cifs_swn_reset_server_dstaddr(server);
 386                         mutex_unlock(&server->srv_mutex);
 387                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 388                 }
 389         } while (server->tcpStatus == CifsNeedReconnect);
 390
 391         spin_lock(&cifs_tcp_ses_lock);
 392         if (server->tcpStatus == CifsNeedNegotiate)
 393                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 394         spin_unlock(&cifs_tcp_ses_lock);
 395
 396         wake_up(&server->response_q);
 397         return rc;
 398 }
 399
 400 #ifdef CONFIG_CIFS_DFS_UPCALL
 401 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 402 {
 403         int rc;
 404         char *hostname;
 405
 406         if (!cifs_swn_set_server_dstaddr(server)) {
 407                 if (server->hostname != target) {
 408                         hostname = extract_hostname(target);
 409                         if (!IS_ERR(hostname)) {
 410                                 kfree(server->hostname);
 411                                 server->hostname = hostname;
 412                         } else {
 413                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 414                                          __func__, PTR_ERR(hostname));
 415                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 416                                          server->hostname);
 417                         }
 418                 }
 419                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 420                 rc = reconn_set_ipaddr_from_hostname(server);
 421                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 422         }
 423         /* Reconnect the socket */
 424         if (cifs_rdma_enabled(server))
 425                 rc = smbd_reconnect(server);
 426         else
 427                 rc = generic_ip_connect(server);
 428
 429         return rc;
 430 }
 431
 432 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 433                                      struct dfs_cache_tgt_iterator **target_hint)
 434 {
 435         int rc;
 436         struct dfs_cache_tgt_iterator *tit;
 437
 438         *target_hint = NULL;
 439
 440         /* If dfs target list is empty, then reconnect to last server */
 441         tit = dfs_cache_get_tgt_iterator(tl);
 442         if (!tit)
 443                 return __reconnect_target_unlocked(server, server->hostname);
 444
 445         /* Otherwise, try every dfs target in @tl */
 446         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 447                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 448                 if (!rc) {
 449                         *target_hint = tit;
 450                         break;
 451                 }
 452         }
 453         return rc;
 454 }
 455
 456 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 457 {
 458         int rc = 0;
 459         const char *refpath = server->current_fullpath + 1;
 460         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 461         struct dfs_cache_tgt_iterator *target_hint = NULL;
 462         int num_targets = 0;
 463
 464         /*
 465          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 466          *
 467          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 468          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 469          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 470          * refreshing the referral, so, in this case, default it to 1.
 471          */
 472         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 473                 num_targets = dfs_cache_get_nr_tgts(&tl);
 474         if (!num_targets)
 475                 num_targets = 1;
 476
 477         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 478                 return 0;
 479
 480         /*
 481          * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 482          * different server or share during failover.  It could be improved by adding some logic to
 483          * only do that in case it connects to a different server or share, though.
 484          */
 485         cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 486
 487         cifs_abort_connection(server);
 488
 489         do {
 490                 try_to_freeze();
 491                 mutex_lock(&server->srv_mutex);
 492
 493                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 494                 if (rc) {
 495                         /* Failed to reconnect socket */
 496                         mutex_unlock(&server->srv_mutex);
 497                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 498                         msleep(3000);
 499                         continue;
 500                 }
 501                 /*
 502                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 503                  * process waiting for reconnect will know it needs to re-establish session and tcon
 504                  * through the reconnected target server.
 505                  */
 506                 atomic_inc(&tcpSesReconnectCount);
 507                 set_credits(server, 1);
 508                 spin_lock(&cifs_tcp_ses_lock);
 509                 if (server->tcpStatus != CifsExiting)
 510                         server->tcpStatus = CifsNeedNegotiate;
 511                 spin_unlock(&cifs_tcp_ses_lock);
 512                 cifs_swn_reset_server_dstaddr(server);
 513                 mutex_unlock(&server->srv_mutex);
 514                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 515         } while (server->tcpStatus == CifsNeedReconnect);
 516
 517         if (target_hint)
 518                 dfs_cache_noreq_update_tgthint(refpath, target_hint);
 519
 520         dfs_cache_free_tgts(&tl);
 521
 522         /* Need to set up echo worker again once connection has been established */
 523         spin_lock(&cifs_tcp_ses_lock);
 524         if (server->tcpStatus == CifsNeedNegotiate)
 525                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 526
 527         spin_unlock(&cifs_tcp_ses_lock);
 528
 529         wake_up(&server->response_q);
 530         return rc;
 531 }
 532
 533 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 534 {
 535         /* If tcp session is not an dfs connection, then reconnect to last target server */
 536         spin_lock(&cifs_tcp_ses_lock);
 537         if (!server->is_dfs_conn) {
 538                 spin_unlock(&cifs_tcp_ses_lock);
 539                 return __cifs_reconnect(server, mark_smb_session);
 540         }
 541         spin_unlock(&cifs_tcp_ses_lock);
 542
 543         mutex_lock(&server->refpath_lock);
 544         if (!server->origin_fullpath || !server->leaf_fullpath) {
 545                 mutex_unlock(&server->refpath_lock);
 546                 return __cifs_reconnect(server, mark_smb_session);
 547         }
 548         mutex_unlock(&server->refpath_lock);
 549
 550         return reconnect_dfs_server(server);
 551 }
 552 #else
 553 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 554 {
 555         return __cifs_reconnect(server, mark_smb_session);
 556 }
 557 #endif
 558
 559 static void
 560 cifs_echo_request(struct work_struct *work)
 561 {
 562         int rc;
 563         struct TCP_Server_Info *server = container_of(work,
 564                                         struct TCP_Server_Info, echo.work);
 565
 566         /*
 567          * We cannot send an echo if it is disabled.
 568          * Also, no need to ping if we got a response recently.
 569          */
 570
 571         if (server->tcpStatus == CifsNeedReconnect ||
 572             server->tcpStatus == CifsExiting ||
 573             server->tcpStatus == CifsNew ||
 574             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 575             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 576                 goto requeue_echo;
 577
 578         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 579         if (rc)
 580                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 581                          server->hostname);
 582
 583         /* Check witness registrations */
 584         cifs_swn_check();
 585
 586 requeue_echo:
 587         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 588 }
 589
 590 static bool
 591 allocate_buffers(struct TCP_Server_Info *server)
 592 {
 593         if (!server->bigbuf) {
 594                 server->bigbuf = (char *)cifs_buf_get();
 595                 if (!server->bigbuf) {
 596                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 597                         msleep(3000);
 598                         /* retry will check if exiting */
 599                         return false;
 600                 }
 601         } else if (server->large_buf) {
 602                 /* we are reusing a dirty large buf, clear its start */
 603                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 604         }
 605
 606         if (!server->smallbuf) {
 607                 server->smallbuf = (char *)cifs_small_buf_get();
 608                 if (!server->smallbuf) {
 609                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 610                         msleep(1000);
 611                         /* retry will check if exiting */
 612                         return false;
 613                 }
 614                 /* beginning of smb buffer is cleared in our buf_get */
 615         } else {
 616                 /* if existing small buf clear beginning */
 617                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 618         }
 619
 620         return true;
 621 }
 622
 623 static bool
 624 server_unresponsive(struct TCP_Server_Info *server)
 625 {
 626         /*
 627          * We need to wait 3 echo intervals to make sure we handle such
 628          * situations right:
 629          * 1s  client sends a normal SMB request
 630          * 2s  client gets a response
 631          * 30s echo workqueue job pops, and decides we got a response recently
 632          *     and don't need to send another
 633          * ...
 634          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 635          *     a response in >60s.
 636          */
 637         spin_lock(&cifs_tcp_ses_lock);
 638         if ((server->tcpStatus == CifsGood ||
 639             server->tcpStatus == CifsNeedNegotiate) &&
 640             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 641             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 642                 spin_unlock(&cifs_tcp_ses_lock);
 643                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 644                          (3 * server->echo_interval) / HZ);
 645                 cifs_reconnect(server, false);
 646                 return true;
 647         }
 648         spin_unlock(&cifs_tcp_ses_lock);
 649
 650         return false;
 651 }
 652
 653 static inline bool
 654 zero_credits(struct TCP_Server_Info *server)
 655 {
 656         int val;
 657
 658         spin_lock(&server->req_lock);
 659         val = server->credits + server->echo_credits + server->oplock_credits;
 660         if (server->in_flight == 0 && val == 0) {
 661                 spin_unlock(&server->req_lock);
 662                 return true;
 663         }
 664         spin_unlock(&server->req_lock);
 665         return false;
 666 }
 667
 668 static int
 669 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 670 {
 671         int length = 0;
 672         int total_read;
 673
 674         smb_msg->msg_control = NULL;
 675         smb_msg->msg_controllen = 0;
 676
 677         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 678                 try_to_freeze();
 679
 680                 /* reconnect if no credits and no requests in flight */
 681                 if (zero_credits(server)) {
 682                         cifs_reconnect(server, false);
 683                         return -ECONNABORTED;
 684                 }
 685
 686                 if (server_unresponsive(server))
 687                         return -ECONNABORTED;
 688                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 689                         length = smbd_recv(server->smbd_conn, smb_msg);
 690                 else
 691                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 692
 693                 spin_lock(&cifs_tcp_ses_lock);
 694                 if (server->tcpStatus == CifsExiting) {
 695                         spin_unlock(&cifs_tcp_ses_lock);
 696                         return -ESHUTDOWN;
 697                 }
 698
 699                 if (server->tcpStatus == CifsNeedReconnect) {
 700                         spin_unlock(&cifs_tcp_ses_lock);
 701                         cifs_reconnect(server, false);
 702                         return -ECONNABORTED;
 703                 }
 704                 spin_unlock(&cifs_tcp_ses_lock);
 705
 706                 if (length == -ERESTARTSYS ||
 707                     length == -EAGAIN ||
 708                     length == -EINTR) {
 709                         /*
 710                          * Minimum sleep to prevent looping, allowing socket
 711                          * to clear and app threads to set tcpStatus
 712                          * CifsNeedReconnect if server hung.
 713                          */
 714                         usleep_range(1000, 2000);
 715                         length = 0;
 716                         continue;
 717                 }
 718
 719                 if (length <= 0) {
 720                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 721                         cifs_reconnect(server, false);
 722                         return -ECONNABORTED;
 723                 }
 724         }
 725         return total_read;
 726 }
 727
 728 int
 729 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 730                       unsigned int to_read)
 731 {
 732         struct msghdr smb_msg;
 733         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 734         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 735
 736         return cifs_readv_from_socket(server, &smb_msg);
 737 }
 738
 739 ssize_t
 740 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 741 {
 742         struct msghdr smb_msg;
 743
 744         /*
 745          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 746          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 747          *  so little to initialize in struct msghdr
 748          */
 749         smb_msg.msg_name = NULL;
 750         smb_msg.msg_namelen = 0;
 751         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 752
 753         return cifs_readv_from_socket(server, &smb_msg);
 754 }
 755
 756 int
 757 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 758         unsigned int page_offset, unsigned int to_read)
 759 {
 760         struct msghdr smb_msg;
 761         struct bio_vec bv = {
 762                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 763         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 764         return cifs_readv_from_socket(server, &smb_msg);
 765 }
 766
 767 static bool
 768 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 769 {
 770         /*
 771          * The first byte big endian of the length field,
 772          * is actually not part of the length but the type
 773          * with the most common, zero, as regular data.
 774          */
 775         switch (type) {
 776         case RFC1002_SESSION_MESSAGE:
 777                 /* Regular SMB response */
 778                 return true;
 779         case RFC1002_SESSION_KEEP_ALIVE:
 780                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 781                 break;
 782         case RFC1002_POSITIVE_SESSION_RESPONSE:
 783                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 784                 break;
 785         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 786                 /*
 787                  * We get this from Windows 98 instead of an error on
 788                  * SMB negprot response.
 789                  */
 790                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 791                 /* give server a second to clean up */
 792                 msleep(1000);
 793                 /*
 794                  * Always try 445 first on reconnect since we get NACK
 795                  * on some if we ever connected to port 139 (the NACK
 796                  * is since we do not begin with RFC1001 session
 797                  * initialize frame).
 798                  */
 799                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 800                 cifs_reconnect(server, true);
 801                 break;
 802         default:
 803                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 804                 cifs_reconnect(server, true);
 805         }
 806
 807         return false;
 808 }
 809
 810 void
 811 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 812 {
 813 #ifdef CONFIG_CIFS_STATS2
 814         mid->when_received = jiffies;
 815 #endif
 816         spin_lock(&GlobalMid_Lock);
 817         if (!malformed)
 818                 mid->mid_state = MID_RESPONSE_RECEIVED;
 819         else
 820                 mid->mid_state = MID_RESPONSE_MALFORMED;
 821         /*
 822          * Trying to handle/dequeue a mid after the send_recv()
 823          * function has finished processing it is a bug.
 824          */
 825         if (mid->mid_flags & MID_DELETED) {
 826                 spin_unlock(&GlobalMid_Lock);
 827                 pr_warn_once("trying to dequeue a deleted mid\n");
 828         } else {
 829                 list_del_init(&mid->qhead);
 830                 mid->mid_flags |= MID_DELETED;
 831                 spin_unlock(&GlobalMid_Lock);
 832         }
 833 }
 834
 835 static unsigned int
 836 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 837 {
 838         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 839
 840         /*
 841          * SMB1 does not use credits.
 842          */
 843         if (server->vals->header_preamble_size)
 844                 return 0;
 845
 846         return le16_to_cpu(shdr->CreditRequest);
 847 }
 848
 849 static void
 850 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 851            char *buf, int malformed)
 852 {
 853         if (server->ops->check_trans2 &&
 854             server->ops->check_trans2(mid, server, buf, malformed))
 855                 return;
 856         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 857         mid->resp_buf = buf;
 858         mid->large_buf = server->large_buf;
 859         /* Was previous buf put in mpx struct for multi-rsp? */
 860         if (!mid->multiRsp) {
 861                 /* smb buffer will be freed by user thread */
 862                 if (server->large_buf)
 863                         server->bigbuf = NULL;
 864                 else
 865                         server->smallbuf = NULL;
 866         }
 867         dequeue_mid(mid, malformed);
 868 }
 869
 870 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 871 {
 872         int length;
 873
 874         /* take it off the list, if it's not already */
 875         spin_lock(&cifs_tcp_ses_lock);
 876         list_del_init(&server->tcp_ses_list);
 877         spin_unlock(&cifs_tcp_ses_lock);
 878
 879         cancel_delayed_work_sync(&server->echo);
 880         cancel_delayed_work_sync(&server->resolve);
 881
 882         spin_lock(&cifs_tcp_ses_lock);
 883         server->tcpStatus = CifsExiting;
 884         spin_unlock(&cifs_tcp_ses_lock);
 885         wake_up_all(&server->response_q);
 886
 887         /* check if we have blocked requests that need to free */
 888         spin_lock(&server->req_lock);
 889         if (server->credits <= 0)
 890                 server->credits = 1;
 891         spin_unlock(&server->req_lock);
 892         /*
 893          * Although there should not be any requests blocked on this queue it
 894          * can not hurt to be paranoid and try to wake up requests that may
 895          * haven been blocked when more than 50 at time were on the wire to the
 896          * same server - they now will see the session is in exit state and get
 897          * out of SendReceive.
 898          */
 899         wake_up_all(&server->request_q);
 900         /* give those requests time to exit */
 901         msleep(125);
 902         if (cifs_rdma_enabled(server))
 903                 smbd_destroy(server);
 904         if (server->ssocket) {
 905                 sock_release(server->ssocket);
 906                 server->ssocket = NULL;
 907         }
 908
 909         if (!list_empty(&server->pending_mid_q)) {
 910                 struct list_head dispose_list;
 911                 struct mid_q_entry *mid_entry;
 912                 struct list_head *tmp, *tmp2;
 913
 914                 INIT_LIST_HEAD(&dispose_list);
 915                 spin_lock(&GlobalMid_Lock);
 916                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 917                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 918                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 919                         kref_get(&mid_entry->refcount);
 920                         mid_entry->mid_state = MID_SHUTDOWN;
 921                         list_move(&mid_entry->qhead, &dispose_list);
 922                         mid_entry->mid_flags |= MID_DELETED;
 923                 }
 924                 spin_unlock(&GlobalMid_Lock);
 925
 926                 /* now walk dispose list and issue callbacks */
 927                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 928                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 929                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 930                         list_del_init(&mid_entry->qhead);
 931                         mid_entry->callback(mid_entry);
 932                         cifs_mid_q_entry_release(mid_entry);
 933                 }
 934                 /* 1/8th of sec is more than enough time for them to exit */
 935                 msleep(125);
 936         }
 937
 938         if (!list_empty(&server->pending_mid_q)) {
 939                 /*
 940                  * mpx threads have not exited yet give them at least the smb
 941                  * send timeout time for long ops.
 942                  *
 943                  * Due to delays on oplock break requests, we need to wait at
 944                  * least 45 seconds before giving up on a request getting a
 945                  * response and going ahead and killing cifsd.
 946                  */
 947                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 948                 msleep(46000);
 949                 /*
 950                  * If threads still have not exited they are probably never
 951                  * coming home not much else we can do but free the memory.
 952                  */
 953         }
 954
 955 #ifdef CONFIG_CIFS_DFS_UPCALL
 956         kfree(server->origin_fullpath);
 957         kfree(server->leaf_fullpath);
 958 #endif
 959         kfree(server);
 960
 961         length = atomic_dec_return(&tcpSesAllocCount);
 962         if (length > 0)
 963                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 964 }
 965
 966 static int
 967 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 968 {
 969         int length;
 970         char *buf = server->smallbuf;
 971         unsigned int pdu_length = server->pdu_size;
 972
 973         /* make sure this will fit in a large buffer */
 974         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
 975                 server->vals->header_preamble_size) {
 976                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 977                 cifs_reconnect(server, true);
 978                 return -ECONNABORTED;
 979         }
 980
 981         /* switch to large buffer if too big for a small one */
 982         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
 983                 server->large_buf = true;
 984                 memcpy(server->bigbuf, buf, server->total_read);
 985                 buf = server->bigbuf;
 986         }
 987
 988         /* now read the rest */
 989         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
 990                                        pdu_length - HEADER_SIZE(server) + 1
 991                                        + server->vals->header_preamble_size);
 992
 993         if (length < 0)
 994                 return length;
 995         server->total_read += length;
 996
 997         dump_smb(buf, server->total_read);
 998
 999         return cifs_handle_standard(server, mid);
1000 }
1001
1002 int
1003 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1004 {
1005         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1006         int length;
1007
1008         /*
1009          * We know that we received enough to get to the MID as we
1010          * checked the pdu_length earlier. Now check to see
1011          * if the rest of the header is OK. We borrow the length
1012          * var for the rest of the loop to avoid a new stack var.
1013          *
1014          * 48 bytes is enough to display the header and a little bit
1015          * into the payload for debugging purposes.
1016          */
1017         length = server->ops->check_message(buf, server->total_read, server);
1018         if (length != 0)
1019                 cifs_dump_mem("Bad SMB: ", buf,
1020                         min_t(unsigned int, server->total_read, 48));
1021
1022         if (server->ops->is_session_expired &&
1023             server->ops->is_session_expired(buf)) {
1024                 cifs_reconnect(server, true);
1025                 return -1;
1026         }
1027
1028         if (server->ops->is_status_pending &&
1029             server->ops->is_status_pending(buf, server))
1030                 return -1;
1031
1032         if (!mid)
1033                 return length;
1034
1035         handle_mid(mid, server, buf, length);
1036         return 0;
1037 }
1038
1039 static void
1040 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1041 {
1042         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1043         int scredits, in_flight;
1044
1045         /*
1046          * SMB1 does not use credits.
1047          */
1048         if (server->vals->header_preamble_size)
1049                 return;
1050
1051         if (shdr->CreditRequest) {
1052                 spin_lock(&server->req_lock);
1053                 server->credits += le16_to_cpu(shdr->CreditRequest);
1054                 scredits = server->credits;
1055                 in_flight = server->in_flight;
1056                 spin_unlock(&server->req_lock);
1057                 wake_up(&server->request_q);
1058
1059                 trace_smb3_hdr_credits(server->CurrentMid,
1060                                 server->conn_id, server->hostname, scredits,
1061                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1062                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1063                                 __func__, le16_to_cpu(shdr->CreditRequest),
1064                                 scredits);
1065         }
1066 }
1067
1068
1069 static int
1070 cifs_demultiplex_thread(void *p)
1071 {
1072         int i, num_mids, length;
1073         struct TCP_Server_Info *server = p;
1074         unsigned int pdu_length;
1075         unsigned int next_offset;
1076         char *buf = NULL;
1077         struct task_struct *task_to_wake = NULL;
1078         struct mid_q_entry *mids[MAX_COMPOUND];
1079         char *bufs[MAX_COMPOUND];
1080         unsigned int noreclaim_flag, num_io_timeout = 0;
1081
1082         noreclaim_flag = memalloc_noreclaim_save();
1083         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1084
1085         length = atomic_inc_return(&tcpSesAllocCount);
1086         if (length > 1)
1087                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1088
1089         set_freezable();
1090         allow_kernel_signal(SIGKILL);
1091         while (server->tcpStatus != CifsExiting) {
1092                 if (try_to_freeze())
1093                         continue;
1094
1095                 if (!allocate_buffers(server))
1096                         continue;
1097
1098                 server->large_buf = false;
1099                 buf = server->smallbuf;
1100                 pdu_length = 4; /* enough to get RFC1001 header */
1101
1102                 length = cifs_read_from_socket(server, buf, pdu_length);
1103                 if (length < 0)
1104                         continue;
1105
1106                 if (server->vals->header_preamble_size == 0)
1107                         server->total_read = 0;
1108                 else
1109                         server->total_read = length;
1110
1111                 /*
1112                  * The right amount was read from socket - 4 bytes,
1113                  * so we can now interpret the length field.
1114                  */
1115                 pdu_length = get_rfc1002_length(buf);
1116
1117                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1118                 if (!is_smb_response(server, buf[0]))
1119                         continue;
1120 next_pdu:
1121                 server->pdu_size = pdu_length;
1122
1123                 /* make sure we have enough to get to the MID */
1124                 if (server->pdu_size < HEADER_SIZE(server) - 1 -
1125                     server->vals->header_preamble_size) {
1126                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1127                                  server->pdu_size);
1128                         cifs_reconnect(server, true);
1129                         continue;
1130                 }
1131
1132                 /* read down to the MID */
1133                 length = cifs_read_from_socket(server,
1134                              buf + server->vals->header_preamble_size,
1135                              HEADER_SIZE(server) - 1
1136                              - server->vals->header_preamble_size);
1137                 if (length < 0)
1138                         continue;
1139                 server->total_read += length;
1140
1141                 if (server->ops->next_header) {
1142                         next_offset = server->ops->next_header(buf);
1143                         if (next_offset)
1144                                 server->pdu_size = next_offset;
1145                 }
1146
1147                 memset(mids, 0, sizeof(mids));
1148                 memset(bufs, 0, sizeof(bufs));
1149                 num_mids = 0;
1150
1151                 if (server->ops->is_transform_hdr &&
1152                     server->ops->receive_transform &&
1153                     server->ops->is_transform_hdr(buf)) {
1154                         length = server->ops->receive_transform(server,
1155                                                                 mids,
1156                                                                 bufs,
1157                                                                 &num_mids);
1158                 } else {
1159                         mids[0] = server->ops->find_mid(server, buf);
1160                         bufs[0] = buf;
1161                         num_mids = 1;
1162
1163                         if (!mids[0] || !mids[0]->receive)
1164                                 length = standard_receive3(server, mids[0]);
1165                         else
1166                                 length = mids[0]->receive(server, mids[0]);
1167                 }
1168
1169                 if (length < 0) {
1170                         for (i = 0; i < num_mids; i++)
1171                                 if (mids[i])
1172                                         cifs_mid_q_entry_release(mids[i]);
1173                         continue;
1174                 }
1175
1176                 if (server->ops->is_status_io_timeout &&
1177                     server->ops->is_status_io_timeout(buf)) {
1178                         num_io_timeout++;
1179                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1180                                 cifs_reconnect(server, false);
1181                                 num_io_timeout = 0;
1182                                 continue;
1183                         }
1184                 }
1185
1186                 server->lstrp = jiffies;
1187
1188                 for (i = 0; i < num_mids; i++) {
1189                         if (mids[i] != NULL) {
1190                                 mids[i]->resp_buf_size = server->pdu_size;
1191
1192                                 if (bufs[i] && server->ops->is_network_name_deleted)
1193                                         server->ops->is_network_name_deleted(bufs[i],
1194                                                                         server);
1195
1196                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1197                                         mids[i]->callback(mids[i]);
1198
1199                                 cifs_mid_q_entry_release(mids[i]);
1200                         } else if (server->ops->is_oplock_break &&
1201                                    server->ops->is_oplock_break(bufs[i],
1202                                                                 server)) {
1203                                 smb2_add_credits_from_hdr(bufs[i], server);
1204                                 cifs_dbg(FYI, "Received oplock break\n");
1205                         } else {
1206                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1207                                                 atomic_read(&midCount));
1208                                 cifs_dump_mem("Received Data is: ", bufs[i],
1209                                               HEADER_SIZE(server));
1210                                 smb2_add_credits_from_hdr(bufs[i], server);
1211 #ifdef CONFIG_CIFS_DEBUG2
1212                                 if (server->ops->dump_detail)
1213                                         server->ops->dump_detail(bufs[i],
1214                                                                  server);
1215                                 cifs_dump_mids(server);
1216 #endif /* CIFS_DEBUG2 */
1217                         }
1218                 }
1219
1220                 if (pdu_length > server->pdu_size) {
1221                         if (!allocate_buffers(server))
1222                                 continue;
1223                         pdu_length -= server->pdu_size;
1224                         server->total_read = 0;
1225                         server->large_buf = false;
1226                         buf = server->smallbuf;
1227                         goto next_pdu;
1228                 }
1229         } /* end while !EXITING */
1230
1231         /* buffer usually freed in free_mid - need to free it here on exit */
1232         cifs_buf_release(server->bigbuf);
1233         if (server->smallbuf) /* no sense logging a debug message if NULL */
1234                 cifs_small_buf_release(server->smallbuf);
1235
1236         task_to_wake = xchg(&server->tsk, NULL);
1237         clean_demultiplex_info(server);
1238
1239         /* if server->tsk was NULL then wait for a signal before exiting */
1240         if (!task_to_wake) {
1241                 set_current_state(TASK_INTERRUPTIBLE);
1242                 while (!signal_pending(current)) {
1243                         schedule();
1244                         set_current_state(TASK_INTERRUPTIBLE);
1245                 }
1246                 set_current_state(TASK_RUNNING);
1247         }
1248
1249         memalloc_noreclaim_restore(noreclaim_flag);
1250         module_put_and_kthread_exit(0);
1251 }
1252
1253 /*
1254  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1255  * if srcaddr is specified and matches the IP address of the rhs argument
1256  */
1257 bool
1258 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1259 {
1260         switch (srcaddr->sa_family) {
1261         case AF_UNSPEC:
1262                 return (rhs->sa_family == AF_UNSPEC);
1263         case AF_INET: {
1264                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1265                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1266                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1267         }
1268         case AF_INET6: {
1269                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1270                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1271                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1272         }
1273         default:
1274                 WARN_ON(1);
1275                 return false; /* don't expect to be here */
1276         }
1277 }
1278
1279 /*
1280  * If no port is specified in addr structure, we try to match with 445 port
1281  * and if it fails - with 139 ports. It should be called only if address
1282  * families of server and addr are equal.
1283  */
1284 static bool
1285 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1286 {
1287         __be16 port, *sport;
1288
1289         /* SMBDirect manages its own ports, don't match it here */
1290         if (server->rdma)
1291                 return true;
1292
1293         switch (addr->sa_family) {
1294         case AF_INET:
1295                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1296                 port = ((struct sockaddr_in *) addr)->sin_port;
1297                 break;
1298         case AF_INET6:
1299                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1300                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1301                 break;
1302         default:
1303                 WARN_ON(1);
1304                 return false;
1305         }
1306
1307         if (!port) {
1308                 port = htons(CIFS_PORT);
1309                 if (port == *sport)
1310                         return true;
1311
1312                 port = htons(RFC1001_PORT);
1313         }
1314
1315         return port == *sport;
1316 }
1317
1318 static bool
1319 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1320               struct sockaddr *srcaddr)
1321 {
1322         switch (addr->sa_family) {
1323         case AF_INET: {
1324                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1325                 struct sockaddr_in *srv_addr4 =
1326                                         (struct sockaddr_in *)&server->dstaddr;
1327
1328                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1329                         return false;
1330                 break;
1331         }
1332         case AF_INET6: {
1333                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1334                 struct sockaddr_in6 *srv_addr6 =
1335                                         (struct sockaddr_in6 *)&server->dstaddr;
1336
1337                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1338                                      &srv_addr6->sin6_addr))
1339                         return false;
1340                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1341                         return false;
1342                 break;
1343         }
1344         default:
1345                 WARN_ON(1);
1346                 return false; /* don't expect to be here */
1347         }
1348
1349         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1350                 return false;
1351
1352         return true;
1353 }
1354
1355 static bool
1356 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1357 {
1358         /*
1359          * The select_sectype function should either return the ctx->sectype
1360          * that was specified, or "Unspecified" if that sectype was not
1361          * compatible with the given NEGOTIATE request.
1362          */
1363         if (server->ops->select_sectype(server, ctx->sectype)
1364              == Unspecified)
1365                 return false;
1366
1367         /*
1368          * Now check if signing mode is acceptable. No need to check
1369          * global_secflags at this point since if MUST_SIGN is set then
1370          * the server->sign had better be too.
1371          */
1372         if (ctx->sign && !server->sign)
1373                 return false;
1374
1375         return true;
1376 }
1377
1378 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1379 {
1380         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1381
1382         if (ctx->nosharesock)
1383                 return 0;
1384
1385         /* this server does not share socket */
1386         if (server->nosharesock)
1387                 return 0;
1388
1389         /* If multidialect negotiation see if existing sessions match one */
1390         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1391                 if (server->vals->protocol_id < SMB30_PROT_ID)
1392                         return 0;
1393         } else if (strcmp(ctx->vals->version_string,
1394                    SMBDEFAULT_VERSION_STRING) == 0) {
1395                 if (server->vals->protocol_id < SMB21_PROT_ID)
1396                         return 0;
1397         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1398                 return 0;
1399
1400         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1401                 return 0;
1402
1403         if (strcasecmp(server->hostname, ctx->server_hostname))
1404                 return 0;
1405
1406         if (!match_address(server, addr,
1407                            (struct sockaddr *)&ctx->srcaddr))
1408                 return 0;
1409
1410         if (!match_port(server, addr))
1411                 return 0;
1412
1413         if (!match_security(server, ctx))
1414                 return 0;
1415
1416         if (server->echo_interval != ctx->echo_interval * HZ)
1417                 return 0;
1418
1419         if (server->rdma != ctx->rdma)
1420                 return 0;
1421
1422         if (server->ignore_signature != ctx->ignore_signature)
1423                 return 0;
1424
1425         if (server->min_offload != ctx->min_offload)
1426                 return 0;
1427
1428         return 1;
1429 }
1430
1431 struct TCP_Server_Info *
1432 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1433 {
1434         struct TCP_Server_Info *server;
1435
1436         spin_lock(&cifs_tcp_ses_lock);
1437         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1438 #ifdef CONFIG_CIFS_DFS_UPCALL
1439                 /*
1440                  * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
1441                  * DFS connections to do failover properly, so avoid sharing them with regular
1442                  * shares or even links that may connect to same server but having completely
1443                  * different failover targets.
1444                  */
1445                 if (server->is_dfs_conn)
1446                         continue;
1447 #endif
1448                 /*
1449                  * Skip ses channels since they're only handled in lower layers
1450                  * (e.g. cifs_send_recv).
1451                  */
1452                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx))
1453                         continue;
1454
1455                 ++server->srv_count;
1456                 spin_unlock(&cifs_tcp_ses_lock);
1457                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1458                 return server;
1459         }
1460         spin_unlock(&cifs_tcp_ses_lock);
1461         return NULL;
1462 }
1463
1464 void
1465 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1466 {
1467         struct task_struct *task;
1468
1469         spin_lock(&cifs_tcp_ses_lock);
1470         if (--server->srv_count > 0) {
1471                 spin_unlock(&cifs_tcp_ses_lock);
1472                 return;
1473         }
1474
1475         /* srv_count can never go negative */
1476         WARN_ON(server->srv_count < 0);
1477
1478         put_net(cifs_net_ns(server));
1479
1480         list_del_init(&server->tcp_ses_list);
1481         spin_unlock(&cifs_tcp_ses_lock);
1482
1483         /* For secondary channels, we pick up ref-count on the primary server */
1484         if (CIFS_SERVER_IS_CHAN(server))
1485                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1486
1487         cancel_delayed_work_sync(&server->echo);
1488         cancel_delayed_work_sync(&server->resolve);
1489
1490         if (from_reconnect)
1491                 /*
1492                  * Avoid deadlock here: reconnect work calls
1493                  * cifs_put_tcp_session() at its end. Need to be sure
1494                  * that reconnect work does nothing with server pointer after
1495                  * that step.
1496                  */
1497                 cancel_delayed_work(&server->reconnect);
1498         else
1499                 cancel_delayed_work_sync(&server->reconnect);
1500
1501         spin_lock(&cifs_tcp_ses_lock);
1502         server->tcpStatus = CifsExiting;
1503         spin_unlock(&cifs_tcp_ses_lock);
1504
1505         cifs_crypto_secmech_release(server);
1506
1507         kfree(server->session_key.response);
1508         server->session_key.response = NULL;
1509         server->session_key.len = 0;
1510         kfree(server->hostname);
1511
1512         task = xchg(&server->tsk, NULL);
1513         if (task)
1514                 send_sig(SIGKILL, task, 1);
1515 }
1516
1517 struct TCP_Server_Info *
1518 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1519                      struct TCP_Server_Info *primary_server)
1520 {
1521         struct TCP_Server_Info *tcp_ses = NULL;
1522         int rc;
1523
1524         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1525
1526         /* see if we already have a matching tcp_ses */
1527         tcp_ses = cifs_find_tcp_session(ctx);
1528         if (tcp_ses)
1529                 return tcp_ses;
1530
1531         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1532         if (!tcp_ses) {
1533                 rc = -ENOMEM;
1534                 goto out_err;
1535         }
1536
1537         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1538         if (!tcp_ses->hostname) {
1539                 rc = -ENOMEM;
1540                 goto out_err;
1541         }
1542
1543         if (ctx->nosharesock)
1544                 tcp_ses->nosharesock = true;
1545
1546         tcp_ses->ops = ctx->ops;
1547         tcp_ses->vals = ctx->vals;
1548         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1549
1550         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1551         tcp_ses->noblockcnt = ctx->rootfs;
1552         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1553         tcp_ses->noautotune = ctx->noautotune;
1554         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1555         tcp_ses->rdma = ctx->rdma;
1556         tcp_ses->in_flight = 0;
1557         tcp_ses->max_in_flight = 0;
1558         tcp_ses->credits = 1;
1559         if (primary_server) {
1560                 spin_lock(&cifs_tcp_ses_lock);
1561                 ++primary_server->srv_count;
1562                 tcp_ses->primary_server = primary_server;
1563                 spin_unlock(&cifs_tcp_ses_lock);
1564         }
1565         init_waitqueue_head(&tcp_ses->response_q);
1566         init_waitqueue_head(&tcp_ses->request_q);
1567         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1568         mutex_init(&tcp_ses->srv_mutex);
1569         memcpy(tcp_ses->workstation_RFC1001_name,
1570                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1571         memcpy(tcp_ses->server_RFC1001_name,
1572                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1573         tcp_ses->session_estab = false;
1574         tcp_ses->sequence_number = 0;
1575         tcp_ses->reconnect_instance = 1;
1576         tcp_ses->lstrp = jiffies;
1577         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1578         spin_lock_init(&tcp_ses->req_lock);
1579         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1580         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1581         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1582         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1583         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1584         mutex_init(&tcp_ses->reconnect_mutex);
1585 #ifdef CONFIG_CIFS_DFS_UPCALL
1586         mutex_init(&tcp_ses->refpath_lock);
1587 #endif
1588         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1589                sizeof(tcp_ses->srcaddr));
1590         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1591                 sizeof(tcp_ses->dstaddr));
1592         if (ctx->use_client_guid)
1593                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1594                        SMB2_CLIENT_GUID_SIZE);
1595         else
1596                 generate_random_uuid(tcp_ses->client_guid);
1597         /*
1598          * at this point we are the only ones with the pointer
1599          * to the struct since the kernel thread not created yet
1600          * no need to spinlock this init of tcpStatus or srv_count
1601          */
1602         tcp_ses->tcpStatus = CifsNew;
1603         ++tcp_ses->srv_count;
1604
1605         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1606                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1607                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1608         else
1609                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1610         if (tcp_ses->rdma) {
1611 #ifndef CONFIG_CIFS_SMB_DIRECT
1612                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1613                 rc = -ENOENT;
1614                 goto out_err_crypto_release;
1615 #endif
1616                 tcp_ses->smbd_conn = smbd_get_connection(
1617                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1618                 if (tcp_ses->smbd_conn) {
1619                         cifs_dbg(VFS, "RDMA transport established\n");
1620                         rc = 0;
1621                         goto smbd_connected;
1622                 } else {
1623                         rc = -ENOENT;
1624                         goto out_err_crypto_release;
1625                 }
1626         }
1627         rc = ip_connect(tcp_ses);
1628         if (rc < 0) {
1629                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1630                 goto out_err_crypto_release;
1631         }
1632 smbd_connected:
1633         /*
1634          * since we're in a cifs function already, we know that
1635          * this will succeed. No need for try_module_get().
1636          */
1637         __module_get(THIS_MODULE);
1638         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1639                                   tcp_ses, "cifsd");
1640         if (IS_ERR(tcp_ses->tsk)) {
1641                 rc = PTR_ERR(tcp_ses->tsk);
1642                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1643                 module_put(THIS_MODULE);
1644                 goto out_err_crypto_release;
1645         }
1646         tcp_ses->min_offload = ctx->min_offload;
1647         /*
1648          * at this point we are the only ones with the pointer
1649          * to the struct since the kernel thread not created yet
1650          * no need to spinlock this update of tcpStatus
1651          */
1652         spin_lock(&cifs_tcp_ses_lock);
1653         tcp_ses->tcpStatus = CifsNeedNegotiate;
1654         spin_unlock(&cifs_tcp_ses_lock);
1655
1656         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1657                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1658         else
1659                 tcp_ses->max_credits = ctx->max_credits;
1660
1661         tcp_ses->nr_targets = 1;
1662         tcp_ses->ignore_signature = ctx->ignore_signature;
1663         /* thread spawned, put it on the list */
1664         spin_lock(&cifs_tcp_ses_lock);
1665         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1666         spin_unlock(&cifs_tcp_ses_lock);
1667
1668         /* queue echo request delayed work */
1669         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1670
1671         /* queue dns resolution delayed work */
1672         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1673                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1674
1675         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1676
1677         return tcp_ses;
1678
1679 out_err_crypto_release:
1680         cifs_crypto_secmech_release(tcp_ses);
1681
1682         put_net(cifs_net_ns(tcp_ses));
1683
1684 out_err:
1685         if (tcp_ses) {
1686                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1687                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1688                 kfree(tcp_ses->hostname);
1689                 if (tcp_ses->ssocket)
1690                         sock_release(tcp_ses->ssocket);
1691                 kfree(tcp_ses);
1692         }
1693         return ERR_PTR(rc);
1694 }
1695
1696 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1697 {
1698         if (ctx->sectype != Unspecified &&
1699             ctx->sectype != ses->sectype)
1700                 return 0;
1701
1702         /*
1703          * If an existing session is limited to less channels than
1704          * requested, it should not be reused
1705          */
1706         spin_lock(&ses->chan_lock);
1707         if (ses->chan_max < ctx->max_channels) {
1708                 spin_unlock(&ses->chan_lock);
1709                 return 0;
1710         }
1711         spin_unlock(&ses->chan_lock);
1712
1713         switch (ses->sectype) {
1714         case Kerberos:
1715                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1716                         return 0;
1717                 break;
1718         default:
1719                 /* NULL username means anonymous session */
1720                 if (ses->user_name == NULL) {
1721                         if (!ctx->nullauth)
1722                                 return 0;
1723                         break;
1724                 }
1725
1726                 /* anything else takes username/password */
1727                 if (strncmp(ses->user_name,
1728                             ctx->username ? ctx->username : "",
1729                             CIFS_MAX_USERNAME_LEN))
1730                         return 0;
1731                 if ((ctx->username && strlen(ctx->username) != 0) &&
1732                     ses->password != NULL &&
1733                     strncmp(ses->password,
1734                             ctx->password ? ctx->password : "",
1735                             CIFS_MAX_PASSWORD_LEN))
1736                         return 0;
1737         }
1738         return 1;
1739 }
1740
1741 /**
1742  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1743  * @ses: smb session to issue the request on
1744  * @ctx: the superblock configuration context to use for building the
1745  *       new tree connection for the IPC (interprocess communication RPC)
1746  *
1747  * A new IPC connection is made and stored in the session
1748  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1749  */
1750 static int
1751 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1752 {
1753         int rc = 0, xid;
1754         struct cifs_tcon *tcon;
1755         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1756         bool seal = false;
1757         struct TCP_Server_Info *server = ses->server;
1758
1759         /*
1760          * If the mount request that resulted in the creation of the
1761          * session requires encryption, force IPC to be encrypted too.
1762          */
1763         if (ctx->seal) {
1764                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1765                         seal = true;
1766                 else {
1767                         cifs_server_dbg(VFS,
1768                                  "IPC: server doesn't support encryption\n");
1769                         return -EOPNOTSUPP;
1770                 }
1771         }
1772
1773         tcon = tconInfoAlloc();
1774         if (tcon == NULL)
1775                 return -ENOMEM;
1776
1777         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1778
1779         xid = get_xid();
1780         tcon->ses = ses;
1781         tcon->ipc = true;
1782         tcon->seal = seal;
1783         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1784         free_xid(xid);
1785
1786         if (rc) {
1787                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1788                 tconInfoFree(tcon);
1789                 goto out;
1790         }
1791
1792         cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid);
1793
1794         ses->tcon_ipc = tcon;
1795 out:
1796         return rc;
1797 }
1798
1799 /**
1800  * cifs_free_ipc - helper to release the session IPC tcon
1801  * @ses: smb session to unmount the IPC from
1802  *
1803  * Needs to be called everytime a session is destroyed.
1804  *
1805  * On session close, the IPC is closed and the server must release all tcons of the session.
1806  * No need to send a tree disconnect here.
1807  *
1808  * Besides, it will make the server to not close durable and resilient files on session close, as
1809  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1810  */
1811 static int
1812 cifs_free_ipc(struct cifs_ses *ses)
1813 {
1814         struct cifs_tcon *tcon = ses->tcon_ipc;
1815
1816         if (tcon == NULL)
1817                 return 0;
1818
1819         tconInfoFree(tcon);
1820         ses->tcon_ipc = NULL;
1821         return 0;
1822 }
1823
1824 static struct cifs_ses *
1825 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1826 {
1827         struct cifs_ses *ses;
1828
1829         spin_lock(&cifs_tcp_ses_lock);
1830         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1831                 if (ses->status == CifsExiting)
1832                         continue;
1833                 if (!match_session(ses, ctx))
1834                         continue;
1835                 ++ses->ses_count;
1836                 spin_unlock(&cifs_tcp_ses_lock);
1837                 return ses;
1838         }
1839         spin_unlock(&cifs_tcp_ses_lock);
1840         return NULL;
1841 }
1842
1843 void cifs_put_smb_ses(struct cifs_ses *ses)
1844 {
1845         unsigned int rc, xid;
1846         unsigned int chan_count;
1847         struct TCP_Server_Info *server = ses->server;
1848         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1849
1850         spin_lock(&cifs_tcp_ses_lock);
1851         if (ses->status == CifsExiting) {
1852                 spin_unlock(&cifs_tcp_ses_lock);
1853                 return;
1854         }
1855
1856         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1857         cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE");
1858
1859         if (--ses->ses_count > 0) {
1860                 spin_unlock(&cifs_tcp_ses_lock);
1861                 return;
1862         }
1863
1864         /* ses_count can never go negative */
1865         WARN_ON(ses->ses_count < 0);
1866
1867         if (ses->status == CifsGood)
1868                 ses->status = CifsExiting;
1869         spin_unlock(&cifs_tcp_ses_lock);
1870
1871         cifs_free_ipc(ses);
1872
1873         if (ses->status == CifsExiting && server->ops->logoff) {
1874                 xid = get_xid();
1875                 rc = server->ops->logoff(xid, ses);
1876                 if (rc)
1877                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1878                                 __func__, rc);
1879                 _free_xid(xid);
1880         }
1881
1882         spin_lock(&cifs_tcp_ses_lock);
1883         list_del_init(&ses->smb_ses_list);
1884         spin_unlock(&cifs_tcp_ses_lock);
1885
1886         spin_lock(&ses->chan_lock);
1887         chan_count = ses->chan_count;
1888
1889         /* close any extra channels */
1890         if (chan_count > 1) {
1891                 int i;
1892
1893                 for (i = 1; i < chan_count; i++) {
1894                         spin_unlock(&ses->chan_lock);
1895                         cifs_put_tcp_session(ses->chans[i].server, 0);
1896                         spin_lock(&ses->chan_lock);
1897                         ses->chans[i].server = NULL;
1898                 }
1899         }
1900         spin_unlock(&ses->chan_lock);
1901
1902         sesInfoFree(ses);
1903         cifs_put_tcp_session(server, 0);
1904 }
1905
1906 #ifdef CONFIG_KEYS
1907
1908 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1909 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1910
1911 /* Populate username and pw fields from keyring if possible */
1912 static int
1913 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1914 {
1915         int rc = 0;
1916         int is_domain = 0;
1917         const char *delim, *payload;
1918         char *desc;
1919         ssize_t len;
1920         struct key *key;
1921         struct TCP_Server_Info *server = ses->server;
1922         struct sockaddr_in *sa;
1923         struct sockaddr_in6 *sa6;
1924         const struct user_key_payload *upayload;
1925
1926         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1927         if (!desc)
1928                 return -ENOMEM;
1929
1930         /* try to find an address key first */
1931         switch (server->dstaddr.ss_family) {
1932         case AF_INET:
1933                 sa = (struct sockaddr_in *)&server->dstaddr;
1934                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1935                 break;
1936         case AF_INET6:
1937                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1938                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1939                 break;
1940         default:
1941                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1942                          server->dstaddr.ss_family);
1943                 rc = -EINVAL;
1944                 goto out_err;
1945         }
1946
1947         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1948         key = request_key(&key_type_logon, desc, "");
1949         if (IS_ERR(key)) {
1950                 if (!ses->domainName) {
1951                         cifs_dbg(FYI, "domainName is NULL\n");
1952                         rc = PTR_ERR(key);
1953                         goto out_err;
1954                 }
1955
1956                 /* didn't work, try to find a domain key */
1957                 sprintf(desc, "cifs:d:%s", ses->domainName);
1958                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1959                 key = request_key(&key_type_logon, desc, "");
1960                 if (IS_ERR(key)) {
1961                         rc = PTR_ERR(key);
1962                         goto out_err;
1963                 }
1964                 is_domain = 1;
1965         }
1966
1967         down_read(&key->sem);
1968         upayload = user_key_payload_locked(key);
1969         if (IS_ERR_OR_NULL(upayload)) {
1970                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1971                 goto out_key_put;
1972         }
1973
1974         /* find first : in payload */
1975         payload = upayload->data;
1976         delim = strnchr(payload, upayload->datalen, ':');
1977         cifs_dbg(FYI, "payload=%s\n", payload);
1978         if (!delim) {
1979                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1980                          upayload->datalen);
1981                 rc = -EINVAL;
1982                 goto out_key_put;
1983         }
1984
1985         len = delim - payload;
1986         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1987                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1988                          len);
1989                 rc = -EINVAL;
1990                 goto out_key_put;
1991         }
1992
1993         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1994         if (!ctx->username) {
1995                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1996                          len);
1997                 rc = -ENOMEM;
1998                 goto out_key_put;
1999         }
2000         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2001
2002         len = key->datalen - (len + 1);
2003         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2004                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2005                 rc = -EINVAL;
2006                 kfree(ctx->username);
2007                 ctx->username = NULL;
2008                 goto out_key_put;
2009         }
2010
2011         ++delim;
2012         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2013         if (!ctx->password) {
2014                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2015                          len);
2016                 rc = -ENOMEM;
2017                 kfree(ctx->username);
2018                 ctx->username = NULL;
2019                 goto out_key_put;
2020         }
2021
2022         /*
2023          * If we have a domain key then we must set the domainName in the
2024          * for the request.
2025          */
2026         if (is_domain && ses->domainName) {
2027                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2028                 if (!ctx->domainname) {
2029                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2030                                  len);
2031                         rc = -ENOMEM;
2032                         kfree(ctx->username);
2033                         ctx->username = NULL;
2034                         kfree_sensitive(ctx->password);
2035                         ctx->password = NULL;
2036                         goto out_key_put;
2037                 }
2038         }
2039
2040         ctx->workstation_name = kstrdup(ses->workstation_name, GFP_KERNEL);
2041         if (!ctx->workstation_name) {
2042                 cifs_dbg(FYI, "Unable to allocate memory for workstation_name\n");
2043                 rc = -ENOMEM;
2044                 kfree(ctx->username);
2045                 ctx->username = NULL;
2046                 kfree_sensitive(ctx->password);
2047                 ctx->password = NULL;
2048                 kfree(ctx->domainname);
2049                 ctx->domainname = NULL;
2050                 goto out_key_put;
2051         }
2052
2053 out_key_put:
2054         up_read(&key->sem);
2055         key_put(key);
2056 out_err:
2057         kfree(desc);
2058         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2059         return rc;
2060 }
2061 #else /* ! CONFIG_KEYS */
2062 static inline int
2063 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2064                    struct cifs_ses *ses __attribute__((unused)))
2065 {
2066         return -ENOSYS;
2067 }
2068 #endif /* CONFIG_KEYS */
2069
2070 /**
2071  * cifs_get_smb_ses - get a session matching @ctx data from @server
2072  * @server: server to setup the session to
2073  * @ctx: superblock configuration context to use to setup the session
2074  *
2075  * This function assumes it is being called from cifs_mount() where we
2076  * already got a server reference (server refcount +1). See
2077  * cifs_get_tcon() for refcount explanations.
2078  */
2079 struct cifs_ses *
2080 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2081 {
2082         int rc = -ENOMEM;
2083         unsigned int xid;
2084         struct cifs_ses *ses;
2085         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2086         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2087
2088         xid = get_xid();
2089
2090         ses = cifs_find_smb_ses(server, ctx);
2091         if (ses) {
2092                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2093                          ses->status);
2094
2095                 spin_lock(&ses->chan_lock);
2096                 if (cifs_chan_needs_reconnect(ses, server)) {
2097                         spin_unlock(&ses->chan_lock);
2098                         cifs_dbg(FYI, "Session needs reconnect\n");
2099
2100                         mutex_lock(&ses->session_mutex);
2101                         rc = cifs_negotiate_protocol(xid, ses, server);
2102                         if (rc) {
2103                                 mutex_unlock(&ses->session_mutex);
2104                                 /* problem -- put our ses reference */
2105                                 cifs_put_smb_ses(ses);
2106                                 free_xid(xid);
2107                                 return ERR_PTR(rc);
2108                         }
2109
2110                         rc = cifs_setup_session(xid, ses, server,
2111                                                 ctx->local_nls);
2112                         if (rc) {
2113                                 mutex_unlock(&ses->session_mutex);
2114                                 /* problem -- put our reference */
2115                                 cifs_put_smb_ses(ses);
2116                                 free_xid(xid);
2117                                 return ERR_PTR(rc);
2118                         }
2119                         mutex_unlock(&ses->session_mutex);
2120
2121                         spin_lock(&ses->chan_lock);
2122                 }
2123                 spin_unlock(&ses->chan_lock);
2124
2125                 /* existing SMB ses has a server reference already */
2126                 cifs_put_tcp_session(server, 0);
2127                 free_xid(xid);
2128                 return ses;
2129         }
2130
2131         cifs_dbg(FYI, "Existing smb sess not found\n");
2132         ses = sesInfoAlloc();
2133         if (ses == NULL)
2134                 goto get_ses_fail;
2135
2136         /* new SMB session uses our server ref */
2137         ses->server = server;
2138         if (server->dstaddr.ss_family == AF_INET6)
2139                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2140         else
2141                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2142
2143         if (ctx->username) {
2144                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2145                 if (!ses->user_name)
2146                         goto get_ses_fail;
2147         }
2148
2149         /* ctx->password freed at unmount */
2150         if (ctx->password) {
2151                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2152                 if (!ses->password)
2153                         goto get_ses_fail;
2154         }
2155         if (ctx->domainname) {
2156                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2157                 if (!ses->domainName)
2158                         goto get_ses_fail;
2159         }
2160         if (ctx->workstation_name) {
2161                 ses->workstation_name = kstrdup(ctx->workstation_name,
2162                                                 GFP_KERNEL);
2163                 if (!ses->workstation_name)
2164                         goto get_ses_fail;
2165         }
2166         if (ctx->domainauto)
2167                 ses->domainAuto = ctx->domainauto;
2168         ses->cred_uid = ctx->cred_uid;
2169         ses->linux_uid = ctx->linux_uid;
2170
2171         ses->sectype = ctx->sectype;
2172         ses->sign = ctx->sign;
2173
2174         /* add server as first channel */
2175         spin_lock(&ses->chan_lock);
2176         ses->chans[0].server = server;
2177         ses->chan_count = 1;
2178         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2179         ses->chans_need_reconnect = 1;
2180         spin_unlock(&ses->chan_lock);
2181
2182         mutex_lock(&ses->session_mutex);
2183         rc = cifs_negotiate_protocol(xid, ses, server);
2184         if (!rc)
2185                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2186         mutex_unlock(&ses->session_mutex);
2187
2188         /* each channel uses a different signing key */
2189         spin_lock(&ses->chan_lock);
2190         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2191                sizeof(ses->smb3signingkey));
2192         spin_unlock(&ses->chan_lock);
2193
2194         if (rc)
2195                 goto get_ses_fail;
2196
2197         /*
2198          * success, put it on the list and add it as first channel
2199          * note: the session becomes active soon after this. So you'll
2200          * need to lock before changing something in the session.
2201          */
2202         spin_lock(&cifs_tcp_ses_lock);
2203         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2204         spin_unlock(&cifs_tcp_ses_lock);
2205
2206         free_xid(xid);
2207
2208         cifs_setup_ipc(ses, ctx);
2209
2210         return ses;
2211
2212 get_ses_fail:
2213         sesInfoFree(ses);
2214         free_xid(xid);
2215         return ERR_PTR(rc);
2216 }
2217
2218 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2219 {
2220         if (tcon->status == TID_EXITING)
2221                 return 0;
2222         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
2223                 return 0;
2224         if (tcon->seal != ctx->seal)
2225                 return 0;
2226         if (tcon->snapshot_time != ctx->snapshot_time)
2227                 return 0;
2228         if (tcon->handle_timeout != ctx->handle_timeout)
2229                 return 0;
2230         if (tcon->no_lease != ctx->no_lease)
2231                 return 0;
2232         if (tcon->nodelete != ctx->nodelete)
2233                 return 0;
2234         return 1;
2235 }
2236
2237 static struct cifs_tcon *
2238 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2239 {
2240         struct list_head *tmp;
2241         struct cifs_tcon *tcon;
2242
2243         spin_lock(&cifs_tcp_ses_lock);
2244         list_for_each(tmp, &ses->tcon_list) {
2245                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
2246
2247                 if (!match_tcon(tcon, ctx))
2248                         continue;
2249                 ++tcon->tc_count;
2250                 spin_unlock(&cifs_tcp_ses_lock);
2251                 return tcon;
2252         }
2253         spin_unlock(&cifs_tcp_ses_lock);
2254         return NULL;
2255 }
2256
2257 void
2258 cifs_put_tcon(struct cifs_tcon *tcon)
2259 {
2260         unsigned int xid;
2261         struct cifs_ses *ses;
2262
2263         /*
2264          * IPC tcon share the lifetime of their session and are
2265          * destroyed in the session put function
2266          */
2267         if (tcon == NULL || tcon->ipc)
2268                 return;
2269
2270         ses = tcon->ses;
2271         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2272         spin_lock(&cifs_tcp_ses_lock);
2273         if (--tcon->tc_count > 0) {
2274                 spin_unlock(&cifs_tcp_ses_lock);
2275                 return;
2276         }
2277
2278         /* tc_count can never go negative */
2279         WARN_ON(tcon->tc_count < 0);
2280
2281         list_del_init(&tcon->tcon_list);
2282         spin_unlock(&cifs_tcp_ses_lock);
2283
2284         if (tcon->use_witness) {
2285                 int rc;
2286
2287                 rc = cifs_swn_unregister(tcon);
2288                 if (rc < 0) {
2289                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2290                                         __func__, rc);
2291                 }
2292         }
2293
2294         xid = get_xid();
2295         if (ses->server->ops->tree_disconnect)
2296                 ses->server->ops->tree_disconnect(xid, tcon);
2297         _free_xid(xid);
2298
2299         cifs_fscache_release_super_cookie(tcon);
2300         tconInfoFree(tcon);
2301         cifs_put_smb_ses(ses);
2302 }
2303
2304 /**
2305  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2306  * @ses: smb session to issue the request on
2307  * @ctx: the superblock configuration context to use for building the
2308  *
2309  * - tcon refcount is the number of mount points using the tcon.
2310  * - ses refcount is the number of tcon using the session.
2311  *
2312  * 1. This function assumes it is being called from cifs_mount() where
2313  *    we already got a session reference (ses refcount +1).
2314  *
2315  * 2. Since we're in the context of adding a mount point, the end
2316  *    result should be either:
2317  *
2318  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2319  *    its session refcount incremented (1 new tcon). This +1 was
2320  *    already done in (1).
2321  *
2322  * b) an existing tcon with refcount+1 (add a mount point to it) and
2323  *    identical ses refcount (no new tcon). Because of (1) we need to
2324  *    decrement the ses refcount.
2325  */
2326 static struct cifs_tcon *
2327 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2328 {
2329         int rc, xid;
2330         struct cifs_tcon *tcon;
2331
2332         tcon = cifs_find_tcon(ses, ctx);
2333         if (tcon) {
2334                 /*
2335                  * tcon has refcount already incremented but we need to
2336                  * decrement extra ses reference gotten by caller (case b)
2337                  */
2338                 cifs_dbg(FYI, "Found match on UNC path\n");
2339                 cifs_put_smb_ses(ses);
2340                 return tcon;
2341         }
2342
2343         if (!ses->server->ops->tree_connect) {
2344                 rc = -ENOSYS;
2345                 goto out_fail;
2346         }
2347
2348         tcon = tconInfoAlloc();
2349         if (tcon == NULL) {
2350                 rc = -ENOMEM;
2351                 goto out_fail;
2352         }
2353
2354         if (ctx->snapshot_time) {
2355                 if (ses->server->vals->protocol_id == 0) {
2356                         cifs_dbg(VFS,
2357                              "Use SMB2 or later for snapshot mount option\n");
2358                         rc = -EOPNOTSUPP;
2359                         goto out_fail;
2360                 } else
2361                         tcon->snapshot_time = ctx->snapshot_time;
2362         }
2363
2364         if (ctx->handle_timeout) {
2365                 if (ses->server->vals->protocol_id == 0) {
2366                         cifs_dbg(VFS,
2367                              "Use SMB2.1 or later for handle timeout option\n");
2368                         rc = -EOPNOTSUPP;
2369                         goto out_fail;
2370                 } else
2371                         tcon->handle_timeout = ctx->handle_timeout;
2372         }
2373
2374         tcon->ses = ses;
2375         if (ctx->password) {
2376                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2377                 if (!tcon->password) {
2378                         rc = -ENOMEM;
2379                         goto out_fail;
2380                 }
2381         }
2382
2383         if (ctx->seal) {
2384                 if (ses->server->vals->protocol_id == 0) {
2385                         cifs_dbg(VFS,
2386                                  "SMB3 or later required for encryption\n");
2387                         rc = -EOPNOTSUPP;
2388                         goto out_fail;
2389                 } else if (tcon->ses->server->capabilities &
2390                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2391                         tcon->seal = true;
2392                 else {
2393                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2394                         rc = -EOPNOTSUPP;
2395                         goto out_fail;
2396                 }
2397         }
2398
2399         if (ctx->linux_ext) {
2400                 if (ses->server->posix_ext_supported) {
2401                         tcon->posix_extensions = true;
2402                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2403                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2404                     (strcmp(ses->server->vals->version_string,
2405                      SMB3ANY_VERSION_STRING) == 0) ||
2406                     (strcmp(ses->server->vals->version_string,
2407                      SMBDEFAULT_VERSION_STRING) == 0)) {
2408                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2409                         rc = -EOPNOTSUPP;
2410                         goto out_fail;
2411                 } else {
2412                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2413                                 "disabled but required for POSIX extensions\n");
2414                         rc = -EOPNOTSUPP;
2415                         goto out_fail;
2416                 }
2417         }
2418
2419         xid = get_xid();
2420         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2421                                             ctx->local_nls);
2422         free_xid(xid);
2423         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2424         if (rc)
2425                 goto out_fail;
2426
2427         tcon->use_persistent = false;
2428         /* check if SMB2 or later, CIFS does not support persistent handles */
2429         if (ctx->persistent) {
2430                 if (ses->server->vals->protocol_id == 0) {
2431                         cifs_dbg(VFS,
2432                              "SMB3 or later required for persistent handles\n");
2433                         rc = -EOPNOTSUPP;
2434                         goto out_fail;
2435                 } else if (ses->server->capabilities &
2436                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2437                         tcon->use_persistent = true;
2438                 else /* persistent handles requested but not supported */ {
2439                         cifs_dbg(VFS,
2440                                 "Persistent handles not supported on share\n");
2441                         rc = -EOPNOTSUPP;
2442                         goto out_fail;
2443                 }
2444         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2445              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2446              && (ctx->nopersistent == false)) {
2447                 cifs_dbg(FYI, "enabling persistent handles\n");
2448                 tcon->use_persistent = true;
2449         } else if (ctx->resilient) {
2450                 if (ses->server->vals->protocol_id == 0) {
2451                         cifs_dbg(VFS,
2452                              "SMB2.1 or later required for resilient handles\n");
2453                         rc = -EOPNOTSUPP;
2454                         goto out_fail;
2455                 }
2456                 tcon->use_resilient = true;
2457         }
2458
2459         tcon->use_witness = false;
2460         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2461                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2462                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2463                                 /*
2464                                  * Set witness in use flag in first place
2465                                  * to retry registration in the echo task
2466                                  */
2467                                 tcon->use_witness = true;
2468                                 /* And try to register immediately */
2469                                 rc = cifs_swn_register(tcon);
2470                                 if (rc < 0) {
2471                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2472                                         goto out_fail;
2473                                 }
2474                         } else {
2475                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2476                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2477                                 rc = -EOPNOTSUPP;
2478                                 goto out_fail;
2479                         }
2480                 } else {
2481                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2482                         rc = -EOPNOTSUPP;
2483                         goto out_fail;
2484                 }
2485         }
2486
2487         /* If the user really knows what they are doing they can override */
2488         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2489                 if (ctx->cache_ro)
2490                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2491                 else if (ctx->cache_rw)
2492                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2493         }
2494
2495         if (ctx->no_lease) {
2496                 if (ses->server->vals->protocol_id == 0) {
2497                         cifs_dbg(VFS,
2498                                 "SMB2 or later required for nolease option\n");
2499                         rc = -EOPNOTSUPP;
2500                         goto out_fail;
2501                 } else
2502                         tcon->no_lease = ctx->no_lease;
2503         }
2504
2505         /*
2506          * We can have only one retry value for a connection to a share so for
2507          * resources mounted more than once to the same server share the last
2508          * value passed in for the retry flag is used.
2509          */
2510         tcon->retry = ctx->retry;
2511         tcon->nocase = ctx->nocase;
2512         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2513                 tcon->nohandlecache = ctx->nohandlecache;
2514         else
2515                 tcon->nohandlecache = true;
2516         tcon->nodelete = ctx->nodelete;
2517         tcon->local_lease = ctx->local_lease;
2518         INIT_LIST_HEAD(&tcon->pending_opens);
2519
2520         spin_lock(&cifs_tcp_ses_lock);
2521         list_add(&tcon->tcon_list, &ses->tcon_list);
2522         spin_unlock(&cifs_tcp_ses_lock);
2523
2524         return tcon;
2525
2526 out_fail:
2527         tconInfoFree(tcon);
2528         return ERR_PTR(rc);
2529 }
2530
2531 void
2532 cifs_put_tlink(struct tcon_link *tlink)
2533 {
2534         if (!tlink || IS_ERR(tlink))
2535                 return;
2536
2537         if (!atomic_dec_and_test(&tlink->tl_count) ||
2538             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2539                 tlink->tl_time = jiffies;
2540                 return;
2541         }
2542
2543         if (!IS_ERR(tlink_tcon(tlink)))
2544                 cifs_put_tcon(tlink_tcon(tlink));
2545         kfree(tlink);
2546         return;
2547 }
2548
2549 static int
2550 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2551 {
2552         struct cifs_sb_info *old = CIFS_SB(sb);
2553         struct cifs_sb_info *new = mnt_data->cifs_sb;
2554         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2555         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2556
2557         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2558                 return 0;
2559
2560         if (old->mnt_cifs_serverino_autodisabled)
2561                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2562
2563         if (oldflags != newflags)
2564                 return 0;
2565
2566         /*
2567          * We want to share sb only if we don't specify an r/wsize or
2568          * specified r/wsize is greater than or equal to existing one.
2569          */
2570         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2571                 return 0;
2572
2573         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2574                 return 0;
2575
2576         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2577             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2578                 return 0;
2579
2580         if (old->ctx->file_mode != new->ctx->file_mode ||
2581             old->ctx->dir_mode != new->ctx->dir_mode)
2582                 return 0;
2583
2584         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2585                 return 0;
2586
2587         if (old->ctx->acregmax != new->ctx->acregmax)
2588                 return 0;
2589         if (old->ctx->acdirmax != new->ctx->acdirmax)
2590                 return 0;
2591
2592         return 1;
2593 }
2594
2595 static int
2596 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2597 {
2598         struct cifs_sb_info *old = CIFS_SB(sb);
2599         struct cifs_sb_info *new = mnt_data->cifs_sb;
2600         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2601                 old->prepath;
2602         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2603                 new->prepath;
2604
2605         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2606                 return 1;
2607         else if (!old_set && !new_set)
2608                 return 1;
2609
2610         return 0;
2611 }
2612
2613 int
2614 cifs_match_super(struct super_block *sb, void *data)
2615 {
2616         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2617         struct smb3_fs_context *ctx;
2618         struct cifs_sb_info *cifs_sb;
2619         struct TCP_Server_Info *tcp_srv;
2620         struct cifs_ses *ses;
2621         struct cifs_tcon *tcon;
2622         struct tcon_link *tlink;
2623         int rc = 0;
2624
2625         spin_lock(&cifs_tcp_ses_lock);
2626         cifs_sb = CIFS_SB(sb);
2627         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2628         if (tlink == NULL) {
2629                 /* can not match superblock if tlink were ever null */
2630                 spin_unlock(&cifs_tcp_ses_lock);
2631                 return 0;
2632         }
2633         tcon = tlink_tcon(tlink);
2634         ses = tcon->ses;
2635         tcp_srv = ses->server;
2636
2637         ctx = mnt_data->ctx;
2638
2639         if (!match_server(tcp_srv, ctx) ||
2640             !match_session(ses, ctx) ||
2641             !match_tcon(tcon, ctx) ||
2642             !match_prepath(sb, mnt_data)) {
2643                 rc = 0;
2644                 goto out;
2645         }
2646
2647         rc = compare_mount_options(sb, mnt_data);
2648 out:
2649         spin_unlock(&cifs_tcp_ses_lock);
2650         cifs_put_tlink(tlink);
2651         return rc;
2652 }
2653
2654 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2655 static struct lock_class_key cifs_key[2];
2656 static struct lock_class_key cifs_slock_key[2];
2657
2658 static inline void
2659 cifs_reclassify_socket4(struct socket *sock)
2660 {
2661         struct sock *sk = sock->sk;
2662         BUG_ON(!sock_allow_reclassification(sk));
2663         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2664                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2665 }
2666
2667 static inline void
2668 cifs_reclassify_socket6(struct socket *sock)
2669 {
2670         struct sock *sk = sock->sk;
2671         BUG_ON(!sock_allow_reclassification(sk));
2672         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2673                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2674 }
2675 #else
2676 static inline void
2677 cifs_reclassify_socket4(struct socket *sock)
2678 {
2679 }
2680
2681 static inline void
2682 cifs_reclassify_socket6(struct socket *sock)
2683 {
2684 }
2685 #endif
2686
2687 /* See RFC1001 section 14 on representation of Netbios names */
2688 static void rfc1002mangle(char *target, char *source, unsigned int length)
2689 {
2690         unsigned int i, j;
2691
2692         for (i = 0, j = 0; i < (length); i++) {
2693                 /* mask a nibble at a time and encode */
2694                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2695                 target[j+1] = 'A' + (0x0F & source[i]);
2696                 j += 2;
2697         }
2698
2699 }
2700
2701 static int
2702 bind_socket(struct TCP_Server_Info *server)
2703 {
2704         int rc = 0;
2705         if (server->srcaddr.ss_family != AF_UNSPEC) {
2706                 /* Bind to the specified local IP address */
2707                 struct socket *socket = server->ssocket;
2708                 rc = socket->ops->bind(socket,
2709                                        (struct sockaddr *) &server->srcaddr,
2710                                        sizeof(server->srcaddr));
2711                 if (rc < 0) {
2712                         struct sockaddr_in *saddr4;
2713                         struct sockaddr_in6 *saddr6;
2714                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2715                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2716                         if (saddr6->sin6_family == AF_INET6)
2717                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2718                                          &saddr6->sin6_addr, rc);
2719                         else
2720                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2721                                          &saddr4->sin_addr.s_addr, rc);
2722                 }
2723         }
2724         return rc;
2725 }
2726
2727 static int
2728 ip_rfc1001_connect(struct TCP_Server_Info *server)
2729 {
2730         int rc = 0;
2731         /*
2732          * some servers require RFC1001 sessinit before sending
2733          * negprot - BB check reconnection in case where second
2734          * sessinit is sent but no second negprot
2735          */
2736         struct rfc1002_session_packet *ses_init_buf;
2737         struct smb_hdr *smb_buf;
2738         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2739                                GFP_KERNEL);
2740         if (ses_init_buf) {
2741                 ses_init_buf->trailer.session_req.called_len = 32;
2742
2743                 if (server->server_RFC1001_name[0] != 0)
2744                         rfc1002mangle(ses_init_buf->trailer.
2745                                       session_req.called_name,
2746                                       server->server_RFC1001_name,
2747                                       RFC1001_NAME_LEN_WITH_NULL);
2748                 else
2749                         rfc1002mangle(ses_init_buf->trailer.
2750                                       session_req.called_name,
2751                                       DEFAULT_CIFS_CALLED_NAME,
2752                                       RFC1001_NAME_LEN_WITH_NULL);
2753
2754                 ses_init_buf->trailer.session_req.calling_len = 32;
2755
2756                 /*
2757                  * calling name ends in null (byte 16) from old smb
2758                  * convention.
2759                  */
2760                 if (server->workstation_RFC1001_name[0] != 0)
2761                         rfc1002mangle(ses_init_buf->trailer.
2762                                       session_req.calling_name,
2763                                       server->workstation_RFC1001_name,
2764                                       RFC1001_NAME_LEN_WITH_NULL);
2765                 else
2766                         rfc1002mangle(ses_init_buf->trailer.
2767                                       session_req.calling_name,
2768                                       "LINUX_CIFS_CLNT",
2769                                       RFC1001_NAME_LEN_WITH_NULL);
2770
2771                 ses_init_buf->trailer.session_req.scope1 = 0;
2772                 ses_init_buf->trailer.session_req.scope2 = 0;
2773                 smb_buf = (struct smb_hdr *)ses_init_buf;
2774
2775                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2776                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2777                 rc = smb_send(server, smb_buf, 0x44);
2778                 kfree(ses_init_buf);
2779                 /*
2780                  * RFC1001 layer in at least one server
2781                  * requires very short break before negprot
2782                  * presumably because not expecting negprot
2783                  * to follow so fast.  This is a simple
2784                  * solution that works without
2785                  * complicating the code and causes no
2786                  * significant slowing down on mount
2787                  * for everyone else
2788                  */
2789                 usleep_range(1000, 2000);
2790         }
2791         /*
2792          * else the negprot may still work without this
2793          * even though malloc failed
2794          */
2795
2796         return rc;
2797 }
2798
2799 static int
2800 generic_ip_connect(struct TCP_Server_Info *server)
2801 {
2802         int rc = 0;
2803         __be16 sport;
2804         int slen, sfamily;
2805         struct socket *socket = server->ssocket;
2806         struct sockaddr *saddr;
2807
2808         saddr = (struct sockaddr *) &server->dstaddr;
2809
2810         if (server->dstaddr.ss_family == AF_INET6) {
2811                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2812
2813                 sport = ipv6->sin6_port;
2814                 slen = sizeof(struct sockaddr_in6);
2815                 sfamily = AF_INET6;
2816                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2817                                 ntohs(sport));
2818         } else {
2819                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2820
2821                 sport = ipv4->sin_port;
2822                 slen = sizeof(struct sockaddr_in);
2823                 sfamily = AF_INET;
2824                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2825                                 ntohs(sport));
2826         }
2827
2828         if (socket == NULL) {
2829                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2830                                    IPPROTO_TCP, &socket, 1);
2831                 if (rc < 0) {
2832                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2833                         server->ssocket = NULL;
2834                         return rc;
2835                 }
2836
2837                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2838                 cifs_dbg(FYI, "Socket created\n");
2839                 server->ssocket = socket;
2840                 socket->sk->sk_allocation = GFP_NOFS;
2841                 if (sfamily == AF_INET6)
2842                         cifs_reclassify_socket6(socket);
2843                 else
2844                         cifs_reclassify_socket4(socket);
2845         }
2846
2847         rc = bind_socket(server);
2848         if (rc < 0)
2849                 return rc;
2850
2851         /*
2852          * Eventually check for other socket options to change from
2853          * the default. sock_setsockopt not used because it expects
2854          * user space buffer
2855          */
2856         socket->sk->sk_rcvtimeo = 7 * HZ;
2857         socket->sk->sk_sndtimeo = 5 * HZ;
2858
2859         /* make the bufsizes depend on wsize/rsize and max requests */
2860         if (server->noautotune) {
2861                 if (socket->sk->sk_sndbuf < (200 * 1024))
2862                         socket->sk->sk_sndbuf = 200 * 1024;
2863                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2864                         socket->sk->sk_rcvbuf = 140 * 1024;
2865         }
2866
2867         if (server->tcp_nodelay)
2868                 tcp_sock_set_nodelay(socket->sk);
2869
2870         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2871                  socket->sk->sk_sndbuf,
2872                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2873
2874         rc = socket->ops->connect(socket, saddr, slen,
2875                                   server->noblockcnt ? O_NONBLOCK : 0);
2876         /*
2877          * When mounting SMB root file systems, we do not want to block in
2878          * connect. Otherwise bail out and then let cifs_reconnect() perform
2879          * reconnect failover - if possible.
2880          */
2881         if (server->noblockcnt && rc == -EINPROGRESS)
2882                 rc = 0;
2883         if (rc < 0) {
2884                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2885                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2886                 sock_release(socket);
2887                 server->ssocket = NULL;
2888                 return rc;
2889         }
2890         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2891         if (sport == htons(RFC1001_PORT))
2892                 rc = ip_rfc1001_connect(server);
2893
2894         return rc;
2895 }
2896
2897 static int
2898 ip_connect(struct TCP_Server_Info *server)
2899 {
2900         __be16 *sport;
2901         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2902         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2903
2904         if (server->dstaddr.ss_family == AF_INET6)
2905                 sport = &addr6->sin6_port;
2906         else
2907                 sport = &addr->sin_port;
2908
2909         if (*sport == 0) {
2910                 int rc;
2911
2912                 /* try with 445 port at first */
2913                 *sport = htons(CIFS_PORT);
2914
2915                 rc = generic_ip_connect(server);
2916                 if (rc >= 0)
2917                         return rc;
2918
2919                 /* if it failed, try with 139 port */
2920                 *sport = htons(RFC1001_PORT);
2921         }
2922
2923         return generic_ip_connect(server);
2924 }
2925
2926 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2927                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2928 {
2929         /*
2930          * If we are reconnecting then should we check to see if
2931          * any requested capabilities changed locally e.g. via
2932          * remount but we can not do much about it here
2933          * if they have (even if we could detect it by the following)
2934          * Perhaps we could add a backpointer to array of sb from tcon
2935          * or if we change to make all sb to same share the same
2936          * sb as NFS - then we only have one backpointer to sb.
2937          * What if we wanted to mount the server share twice once with
2938          * and once without posixacls or posix paths?
2939          */
2940         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2941
2942         if (ctx && ctx->no_linux_ext) {
2943                 tcon->fsUnixInfo.Capability = 0;
2944                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2945                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2946                 return;
2947         } else if (ctx)
2948                 tcon->unix_ext = 1; /* Unix Extensions supported */
2949
2950         if (!tcon->unix_ext) {
2951                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2952                 return;
2953         }
2954
2955         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2956                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2957                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2958                 /*
2959                  * check for reconnect case in which we do not
2960                  * want to change the mount behavior if we can avoid it
2961                  */
2962                 if (ctx == NULL) {
2963                         /*
2964                          * turn off POSIX ACL and PATHNAMES if not set
2965                          * originally at mount time
2966                          */
2967                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2968                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2969                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2970                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2971                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2972                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2973                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2974                                 cifs_dbg(VFS, "possible reconnect error\n");
2975                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2976                         }
2977                 }
2978
2979                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2980                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2981
2982                 cap &= CIFS_UNIX_CAP_MASK;
2983                 if (ctx && ctx->no_psx_acl)
2984                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2985                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2986                         cifs_dbg(FYI, "negotiated posix acl support\n");
2987                         if (cifs_sb)
2988                                 cifs_sb->mnt_cifs_flags |=
2989                                         CIFS_MOUNT_POSIXACL;
2990                 }
2991
2992                 if (ctx && ctx->posix_paths == 0)
2993                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2994                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2995                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2996                         if (cifs_sb)
2997                                 cifs_sb->mnt_cifs_flags |=
2998                                         CIFS_MOUNT_POSIX_PATHS;
2999                 }
3000
3001                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3002 #ifdef CONFIG_CIFS_DEBUG2
3003                 if (cap & CIFS_UNIX_FCNTL_CAP)
3004                         cifs_dbg(FYI, "FCNTL cap\n");
3005                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3006                         cifs_dbg(FYI, "EXTATTR cap\n");
3007                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3008                         cifs_dbg(FYI, "POSIX path cap\n");
3009                 if (cap & CIFS_UNIX_XATTR_CAP)
3010                         cifs_dbg(FYI, "XATTR cap\n");
3011                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3012                         cifs_dbg(FYI, "POSIX ACL cap\n");
3013                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3014                         cifs_dbg(FYI, "very large read cap\n");
3015                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3016                         cifs_dbg(FYI, "very large write cap\n");
3017                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3018                         cifs_dbg(FYI, "transport encryption cap\n");
3019                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3020                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3021 #endif /* CIFS_DEBUG2 */
3022                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3023                         if (ctx == NULL)
3024                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3025                         else
3026                                 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");
3027
3028                 }
3029         }
3030 }
3031
3032 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3033 {
3034         struct smb3_fs_context *ctx = cifs_sb->ctx;
3035
3036         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3037
3038         spin_lock_init(&cifs_sb->tlink_tree_lock);
3039         cifs_sb->tlink_tree = RB_ROOT;
3040
3041         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3042                  ctx->file_mode, ctx->dir_mode);
3043
3044         /* this is needed for ASCII cp to Unicode converts */
3045         if (ctx->iocharset == NULL) {
3046                 /* load_nls_default cannot return null */
3047                 cifs_sb->local_nls = load_nls_default();
3048         } else {
3049                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3050                 if (cifs_sb->local_nls == NULL) {
3051                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3052                                  ctx->iocharset);
3053                         return -ELIBACC;
3054                 }
3055         }
3056         ctx->local_nls = cifs_sb->local_nls;
3057
3058         smb3_update_mnt_flags(cifs_sb);
3059
3060         if (ctx->direct_io)
3061                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3062         if (ctx->cache_ro) {
3063                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3064                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3065         } else if (ctx->cache_rw) {
3066                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3067                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3068                                             CIFS_MOUNT_RW_CACHE);
3069         }
3070
3071         if ((ctx->cifs_acl) && (ctx->dynperm))
3072                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3073
3074         if (ctx->prepath) {
3075                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3076                 if (cifs_sb->prepath == NULL)
3077                         return -ENOMEM;
3078                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3079         }
3080
3081         return 0;
3082 }
3083
3084 /* Release all succeed connections */
3085 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
3086 {
3087         int rc = 0;
3088
3089         if (mnt_ctx->tcon)
3090                 cifs_put_tcon(mnt_ctx->tcon);
3091         else if (mnt_ctx->ses)
3092                 cifs_put_smb_ses(mnt_ctx->ses);
3093         else if (mnt_ctx->server)
3094                 cifs_put_tcp_session(mnt_ctx->server, 0);
3095         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3096         free_xid(mnt_ctx->xid);
3097 }
3098
3099 /* Get connections for tcp, ses and tcon */
3100 static int mount_get_conns(struct mount_ctx *mnt_ctx)
3101 {
3102         int rc = 0;
3103         struct TCP_Server_Info *server = NULL;
3104         struct cifs_ses *ses = NULL;
3105         struct cifs_tcon *tcon = NULL;
3106         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3107         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3108         unsigned int xid;
3109
3110         xid = get_xid();
3111
3112         /* get a reference to a tcp session */
3113         server = cifs_get_tcp_session(ctx, NULL);
3114         if (IS_ERR(server)) {
3115                 rc = PTR_ERR(server);
3116                 server = NULL;
3117                 goto out;
3118         }
3119
3120         /* get a reference to a SMB session */
3121         ses = cifs_get_smb_ses(server, ctx);
3122         if (IS_ERR(ses)) {
3123                 rc = PTR_ERR(ses);
3124                 ses = NULL;
3125                 goto out;
3126         }
3127
3128         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3129                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3130                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3131                 rc = -EOPNOTSUPP;
3132                 goto out;
3133         }
3134
3135         /* search for existing tcon to this server share */
3136         tcon = cifs_get_tcon(ses, ctx);
3137         if (IS_ERR(tcon)) {
3138                 rc = PTR_ERR(tcon);
3139                 tcon = NULL;
3140                 goto out;
3141         }
3142
3143         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3144         if (tcon->posix_extensions)
3145                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3146
3147         /* tell server which Unix caps we support */
3148         if (cap_unix(tcon->ses)) {
3149                 /*
3150                  * reset of caps checks mount to see if unix extensions disabled
3151                  * for just this mount.
3152                  */
3153                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3154                 spin_lock(&cifs_tcp_ses_lock);
3155                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3156                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3157                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3158                         spin_unlock(&cifs_tcp_ses_lock);
3159                         rc = -EACCES;
3160                         goto out;
3161                 }
3162                 spin_unlock(&cifs_tcp_ses_lock);
3163         } else
3164                 tcon->unix_ext = 0; /* server does not support them */
3165
3166         /* do not care if a following call succeed - informational */
3167         if (!tcon->pipe && server->ops->qfs_tcon) {
3168                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3169                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3170                         if (tcon->fsDevInfo.DeviceCharacteristics &
3171                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3172                                 cifs_dbg(VFS, "mounted to read only share\n");
3173                         else if ((cifs_sb->mnt_cifs_flags &
3174                                   CIFS_MOUNT_RW_CACHE) == 0)
3175                                 cifs_dbg(VFS, "read only mount of RW share\n");
3176                         /* no need to log a RW mount of a typical RW share */
3177                 }
3178         }
3179
3180         /*
3181          * Clamp the rsize/wsize mount arguments if they are too big for the server
3182          * and set the rsize/wsize to the negotiated values if not passed in by
3183          * the user on mount
3184          */
3185         if ((cifs_sb->ctx->wsize == 0) ||
3186             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3187                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3188         if ((cifs_sb->ctx->rsize == 0) ||
3189             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3190                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3191
3192         /*
3193          * The cookie is initialized from volume info returned above.
3194          * Inside cifs_fscache_get_super_cookie it checks
3195          * that we do not get super cookie twice.
3196          */
3197         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3198                 cifs_fscache_get_super_cookie(tcon);
3199
3200 out:
3201         mnt_ctx->server = server;
3202         mnt_ctx->ses = ses;
3203         mnt_ctx->tcon = tcon;
3204         mnt_ctx->xid = xid;
3205
3206         return rc;
3207 }
3208
3209 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3210                              struct cifs_tcon *tcon)
3211 {
3212         struct tcon_link *tlink;
3213
3214         /* hang the tcon off of the superblock */
3215         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3216         if (tlink == NULL)
3217                 return -ENOMEM;
3218
3219         tlink->tl_uid = ses->linux_uid;
3220         tlink->tl_tcon = tcon;
3221         tlink->tl_time = jiffies;
3222         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3223         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3224
3225         cifs_sb->master_tlink = tlink;
3226         spin_lock(&cifs_sb->tlink_tree_lock);
3227         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3228         spin_unlock(&cifs_sb->tlink_tree_lock);
3229
3230         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3231                                 TLINK_IDLE_EXPIRE);
3232         return 0;
3233 }
3234
3235 #ifdef CONFIG_CIFS_DFS_UPCALL
3236 /* Get unique dfs connections */
3237 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3238 {
3239         int rc;
3240
3241         mnt_ctx->fs_ctx->nosharesock = true;
3242         rc = mount_get_conns(mnt_ctx);
3243         if (mnt_ctx->server) {
3244                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3245                 spin_lock(&cifs_tcp_ses_lock);
3246                 mnt_ctx->server->is_dfs_conn = true;
3247                 spin_unlock(&cifs_tcp_ses_lock);
3248         }
3249         return rc;
3250 }
3251
3252 /*
3253  * cifs_build_path_to_root returns full path to root when we do not have an
3254  * existing connection (tcon)
3255  */
3256 static char *
3257 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3258                        const struct cifs_sb_info *cifs_sb, bool useppath)
3259 {
3260         char *full_path, *pos;
3261         unsigned int pplen = useppath && ctx->prepath ?
3262                 strlen(ctx->prepath) + 1 : 0;
3263         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3264
3265         if (unc_len > MAX_TREE_SIZE)
3266                 return ERR_PTR(-EINVAL);
3267
3268         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3269         if (full_path == NULL)
3270                 return ERR_PTR(-ENOMEM);
3271
3272         memcpy(full_path, ctx->UNC, unc_len);
3273         pos = full_path + unc_len;
3274
3275         if (pplen) {
3276                 *pos = CIFS_DIR_SEP(cifs_sb);
3277                 memcpy(pos + 1, ctx->prepath, pplen);
3278                 pos += pplen;
3279         }
3280
3281         *pos = '\0'; /* add trailing null */
3282         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3283         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3284         return full_path;
3285 }
3286
3287 /*
3288  * expand_dfs_referral - Update cifs_sb from dfs referral path
3289  *
3290  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3291  * submount.  Otherwise it will be left untouched.
3292  */
3293 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3294                                struct dfs_info3_param *referral)
3295 {
3296         int rc;
3297         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3298         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3299         char *fake_devname = NULL, *mdata = NULL;
3300
3301         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3302                                            &fake_devname);
3303         if (IS_ERR(mdata)) {
3304                 rc = PTR_ERR(mdata);
3305                 mdata = NULL;
3306         } else {
3307                 /*
3308                  * We can not clear out the whole structure since we no longer have an explicit
3309                  * function to parse a mount-string. Instead we need to clear out the individual
3310                  * fields that are no longer valid.
3311                  */
3312                 kfree(ctx->prepath);
3313                 ctx->prepath = NULL;
3314                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3315         }
3316         kfree(fake_devname);
3317         kfree(cifs_sb->ctx->mount_options);
3318         cifs_sb->ctx->mount_options = mdata;
3319
3320         return rc;
3321 }
3322 #endif
3323
3324 /* TODO: all callers to this are broken. We are not parsing mount_options here
3325  * we should pass a clone of the original context?
3326  */
3327 int
3328 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3329 {
3330         int rc;
3331
3332         if (devname) {
3333                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3334                 rc = smb3_parse_devname(devname, ctx);
3335                 if (rc) {
3336                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3337                         return rc;
3338                 }
3339         }
3340
3341         if (mntopts) {
3342                 char *ip;
3343
3344                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3345                 if (rc) {
3346                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3347                         return rc;
3348                 }
3349
3350                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3351                 kfree(ip);
3352                 if (!rc) {
3353                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3354                         return -EINVAL;
3355                 }
3356         }
3357
3358         if (ctx->nullauth) {
3359                 cifs_dbg(FYI, "Anonymous login\n");
3360                 kfree(ctx->username);
3361                 ctx->username = NULL;
3362         } else if (ctx->username) {
3363                 /* BB fixme parse for domain name here */
3364                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3365         } else {
3366                 cifs_dbg(VFS, "No username specified\n");
3367         /* In userspace mount helper we can get user name from alternate
3368            locations such as env variables and files on disk */
3369                 return -EINVAL;
3370         }
3371
3372         return 0;
3373 }
3374
3375 static int
3376 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3377                                         unsigned int xid,
3378                                         struct cifs_tcon *tcon,
3379                                         struct cifs_sb_info *cifs_sb,
3380                                         char *full_path,
3381                                         int added_treename)
3382 {
3383         int rc;
3384         char *s;
3385         char sep, tmp;
3386         int skip = added_treename ? 1 : 0;
3387
3388         sep = CIFS_DIR_SEP(cifs_sb);
3389         s = full_path;
3390
3391         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3392         while (rc == 0) {
3393                 /* skip separators */
3394                 while (*s == sep)
3395                         s++;
3396                 if (!*s)
3397                         break;
3398                 /* next separator */
3399                 while (*s && *s != sep)
3400                         s++;
3401                 /*
3402                  * if the treename is added, we then have to skip the first
3403                  * part within the separators
3404                  */
3405                 if (skip) {
3406                         skip = 0;
3407                         continue;
3408                 }
3409                 /*
3410                  * temporarily null-terminate the path at the end of
3411                  * the current component
3412                  */
3413                 tmp = *s;
3414                 *s = 0;
3415                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3416                                                      full_path);
3417                 *s = tmp;
3418         }
3419         return rc;
3420 }
3421
3422 /*
3423  * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
3424  * otherwise 0.
3425  */
3426 static int is_path_remote(struct mount_ctx *mnt_ctx)
3427 {
3428         int rc;
3429         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3430         struct TCP_Server_Info *server = mnt_ctx->server;
3431         unsigned int xid = mnt_ctx->xid;
3432         struct cifs_tcon *tcon = mnt_ctx->tcon;
3433         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3434         char *full_path;
3435
3436         if (!server->ops->is_path_accessible)
3437                 return -EOPNOTSUPP;
3438
3439         /*
3440          * cifs_build_path_to_root works only when we have a valid tcon
3441          */
3442         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3443                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3444         if (full_path == NULL)
3445                 return -ENOMEM;
3446
3447         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3448
3449         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3450                                              full_path);
3451 #ifdef CONFIG_CIFS_DFS_UPCALL
3452         if (rc == -ENOENT && is_tcon_dfs(tcon))
3453                 rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
3454                                                         full_path);
3455 #endif
3456         if (rc != 0 && rc != -EREMOTE) {
3457                 kfree(full_path);
3458                 return rc;
3459         }
3460
3461         if (rc != -EREMOTE) {
3462                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3463                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3464                 if (rc != 0) {
3465                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3466                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3467                         rc = 0;
3468                 }
3469         }
3470
3471         kfree(full_path);
3472         return rc;
3473 }
3474
3475 #ifdef CONFIG_CIFS_DFS_UPCALL
3476 static void set_root_ses(struct mount_ctx *mnt_ctx)
3477 {
3478         if (mnt_ctx->ses) {
3479                 spin_lock(&cifs_tcp_ses_lock);
3480                 mnt_ctx->ses->ses_count++;
3481                 spin_unlock(&cifs_tcp_ses_lock);
3482                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3483         }
3484         mnt_ctx->root_ses = mnt_ctx->ses;
3485 }
3486
3487 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3488 {
3489         int rc;
3490         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3491         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3492
3493         *isdfs = true;
3494
3495         rc = mount_get_conns(mnt_ctx);
3496         /*
3497          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3498          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3499          *
3500          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3501          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3502          */
3503         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3504             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3505                            ctx->UNC + 1, NULL, root_tl)) {
3506                 if (rc)
3507                         return rc;
3508                 /* Check if it is fully accessible and then mount it */
3509                 rc = is_path_remote(mnt_ctx);
3510                 if (!rc)
3511                         *isdfs = false;
3512                 else if (rc != -EREMOTE)
3513                         return rc;
3514         }
3515         return 0;
3516 }
3517
3518 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3519                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3520 {
3521         int rc;
3522         struct dfs_info3_param ref = {};
3523         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3524         char *oldmnt = cifs_sb->ctx->mount_options;
3525
3526         cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
3527                  dfs_cache_get_tgt_name(tit));
3528
3529         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3530         if (rc)
3531                 goto out;
3532
3533         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3534         if (rc)
3535                 goto out;
3536
3537         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3538         if (oldmnt != cifs_sb->ctx->mount_options) {
3539                 mount_put_conns(mnt_ctx);
3540                 rc = mount_get_dfs_conns(mnt_ctx);
3541         }
3542         if (!rc) {
3543                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3544                         set_root_ses(mnt_ctx);
3545                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3546                                               cifs_remap(cifs_sb), ref_path, tit);
3547         }
3548
3549 out:
3550         free_dfs_info_param(&ref);
3551         return rc;
3552 }
3553
3554 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3555 {
3556         int rc;
3557         char *full_path;
3558         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3559         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3560         struct dfs_cache_tgt_iterator *tit;
3561
3562         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3563          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3564          * now on.
3565          */
3566         mount_put_conns(mnt_ctx);
3567         mount_get_dfs_conns(mnt_ctx);
3568         set_root_ses(mnt_ctx);
3569
3570         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3571         if (IS_ERR(full_path))
3572                 return PTR_ERR(full_path);
3573
3574         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3575                                                             cifs_remap(cifs_sb));
3576         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3577                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3578                 mnt_ctx->origin_fullpath = NULL;
3579                 goto out;
3580         }
3581
3582         /* Try all dfs root targets */
3583         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3584              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3585                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3586                 if (!rc) {
3587                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3588                         if (!mnt_ctx->leaf_fullpath)
3589                                 rc = -ENOMEM;
3590                         break;
3591                 }
3592         }
3593
3594 out:
3595         kfree(full_path);
3596         return rc;
3597 }
3598
3599 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3600 {
3601         int rc;
3602         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3603         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3604         char *full_path;
3605         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3606         struct dfs_cache_tgt_iterator *tit;
3607
3608         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3609         if (IS_ERR(full_path))
3610                 return PTR_ERR(full_path);
3611
3612         kfree(mnt_ctx->leaf_fullpath);
3613         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3614                                                           cifs_remap(cifs_sb));
3615         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3616                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3617                 mnt_ctx->leaf_fullpath = NULL;
3618                 goto out;
3619         }
3620
3621         /* Get referral from dfs link */
3622         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3623                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3624         if (rc)
3625                 goto out;
3626
3627         /* Try all dfs link targets.  If an I/O fails from currently connected DFS target with an
3628          * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
3629          * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
3630          * STATUS_PATH_NOT_COVERED."
3631          */
3632         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3633              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3634                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3635                 if (!rc) {
3636                         rc = is_path_remote(mnt_ctx);
3637                         if (!rc || rc == -EREMOTE)
3638                                 break;
3639                 }
3640         }
3641
3642 out:
3643         kfree(full_path);
3644         dfs_cache_free_tgts(&tl);
3645         return rc;
3646 }
3647
3648 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3649 {
3650         int rc;
3651         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3652         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3653         char *full_path;
3654         int num_links = 0;
3655
3656         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3657         if (IS_ERR(full_path))
3658                 return PTR_ERR(full_path);
3659
3660         kfree(mnt_ctx->origin_fullpath);
3661         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3662                                                             cifs_remap(cifs_sb));
3663         kfree(full_path);
3664
3665         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3666                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3667                 mnt_ctx->origin_fullpath = NULL;
3668                 return rc;
3669         }
3670
3671         do {
3672                 rc = __follow_dfs_link(mnt_ctx);
3673                 if (!rc || rc != -EREMOTE)
3674                         break;
3675         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3676
3677         return rc;
3678 }
3679
3680 /* Set up DFS referral paths for failover */
3681 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3682 {
3683         struct TCP_Server_Info *server = mnt_ctx->server;
3684
3685         mutex_lock(&server->refpath_lock);
3686         server->origin_fullpath = mnt_ctx->origin_fullpath;
3687         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3688         server->current_fullpath = mnt_ctx->leaf_fullpath;
3689         mutex_unlock(&server->refpath_lock);
3690         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3691 }
3692
3693 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3694 {
3695         int rc;
3696         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3697         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3698         bool isdfs;
3699
3700         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3701         if (rc)
3702                 goto error;
3703         if (!isdfs)
3704                 goto out;
3705
3706         uuid_gen(&mnt_ctx.mount_id);
3707         rc = connect_dfs_root(&mnt_ctx, &tl);
3708         dfs_cache_free_tgts(&tl);
3709
3710         if (rc)
3711                 goto error;
3712
3713         rc = is_path_remote(&mnt_ctx);
3714         if (rc)
3715                 rc = follow_dfs_link(&mnt_ctx);
3716         if (rc)
3717                 goto error;
3718
3719         setup_server_referral_paths(&mnt_ctx);
3720         /*
3721          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3722          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3723          */
3724         cifs_autodisable_serverino(cifs_sb);
3725         /*
3726          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3727          * that have different prefix paths.
3728          */
3729         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3730         kfree(cifs_sb->prepath);
3731         cifs_sb->prepath = ctx->prepath;
3732         ctx->prepath = NULL;
3733         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3734
3735 out:
3736         free_xid(mnt_ctx.xid);
3737         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3738         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3739
3740 error:
3741         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3742         kfree(mnt_ctx.origin_fullpath);
3743         kfree(mnt_ctx.leaf_fullpath);
3744         mount_put_conns(&mnt_ctx);
3745         return rc;
3746 }
3747 #else
3748 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3749 {
3750         int rc = 0;
3751         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3752
3753         rc = mount_get_conns(&mnt_ctx);
3754         if (rc)
3755                 goto error;
3756
3757         if (mnt_ctx.tcon) {
3758                 rc = is_path_remote(&mnt_ctx);
3759                 if (rc == -EREMOTE)
3760                         rc = -EOPNOTSUPP;
3761                 if (rc)
3762                         goto error;
3763         }
3764
3765         free_xid(mnt_ctx.xid);
3766         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3767
3768 error:
3769         mount_put_conns(&mnt_ctx);
3770         return rc;
3771 }
3772 #endif
3773
3774 /*
3775  * Issue a TREE_CONNECT request.
3776  */
3777 int
3778 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3779          const char *tree, struct cifs_tcon *tcon,
3780          const struct nls_table *nls_codepage)
3781 {
3782         struct smb_hdr *smb_buffer;
3783         struct smb_hdr *smb_buffer_response;
3784         TCONX_REQ *pSMB;
3785         TCONX_RSP *pSMBr;
3786         unsigned char *bcc_ptr;
3787         int rc = 0;
3788         int length;
3789         __u16 bytes_left, count;
3790
3791         if (ses == NULL)
3792                 return -EIO;
3793
3794         smb_buffer = cifs_buf_get();
3795         if (smb_buffer == NULL)
3796                 return -ENOMEM;
3797
3798         smb_buffer_response = smb_buffer;
3799
3800         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3801                         NULL /*no tid */ , 4 /*wct */ );
3802
3803         smb_buffer->Mid = get_next_mid(ses->server);
3804         smb_buffer->Uid = ses->Suid;
3805         pSMB = (TCONX_REQ *) smb_buffer;
3806         pSMBr = (TCONX_RSP *) smb_buffer_response;
3807
3808         pSMB->AndXCommand = 0xFF;
3809         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3810         bcc_ptr = &pSMB->Password[0];
3811         if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
3812                 pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3813                 *bcc_ptr = 0; /* password is null byte */
3814                 bcc_ptr++;              /* skip password */
3815                 /* already aligned so no need to do it below */
3816         }
3817
3818         if (ses->server->sign)
3819                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3820
3821         if (ses->capabilities & CAP_STATUS32) {
3822                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3823         }
3824         if (ses->capabilities & CAP_DFS) {
3825                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3826         }
3827         if (ses->capabilities & CAP_UNICODE) {
3828                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3829                 length =
3830                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3831                         6 /* max utf8 char length in bytes */ *
3832                         (/* server len*/ + 256 /* share len */), nls_codepage);
3833                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3834                 bcc_ptr += 2;   /* skip trailing null */
3835         } else {                /* ASCII */
3836                 strcpy(bcc_ptr, tree);
3837                 bcc_ptr += strlen(tree) + 1;
3838         }
3839         strcpy(bcc_ptr, "?????");
3840         bcc_ptr += strlen("?????");
3841         bcc_ptr += 1;
3842         count = bcc_ptr - &pSMB->Password[0];
3843         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3844         pSMB->ByteCount = cpu_to_le16(count);
3845
3846         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3847                          0);
3848
3849         /* above now done in SendReceive */
3850         if (rc == 0) {
3851                 bool is_unicode;
3852
3853                 tcon->tid = smb_buffer_response->Tid;
3854                 bcc_ptr = pByteArea(smb_buffer_response);
3855                 bytes_left = get_bcc(smb_buffer_response);
3856                 length = strnlen(bcc_ptr, bytes_left - 2);
3857                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3858                         is_unicode = true;
3859                 else
3860                         is_unicode = false;
3861
3862
3863                 /* skip service field (NB: this field is always ASCII) */
3864                 if (length == 3) {
3865                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3866                             (bcc_ptr[2] == 'C')) {
3867                                 cifs_dbg(FYI, "IPC connection\n");
3868                                 tcon->ipc = true;
3869                                 tcon->pipe = true;
3870                         }
3871                 } else if (length == 2) {
3872                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3873                                 /* the most common case */
3874                                 cifs_dbg(FYI, "disk share connection\n");
3875                         }
3876                 }
3877                 bcc_ptr += length + 1;
3878                 bytes_left -= (length + 1);
3879                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3880
3881                 /* mostly informational -- no need to fail on error here */
3882                 kfree(tcon->nativeFileSystem);
3883                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3884                                                       bytes_left, is_unicode,
3885                                                       nls_codepage);
3886
3887                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3888
3889                 if ((smb_buffer_response->WordCount == 3) ||
3890                          (smb_buffer_response->WordCount == 7))
3891                         /* field is in same location */
3892                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3893                 else
3894                         tcon->Flags = 0;
3895                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3896         }
3897
3898         cifs_buf_release(smb_buffer);
3899         return rc;
3900 }
3901
3902 static void delayed_free(struct rcu_head *p)
3903 {
3904         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3905
3906         unload_nls(cifs_sb->local_nls);
3907         smb3_cleanup_fs_context(cifs_sb->ctx);
3908         kfree(cifs_sb);
3909 }
3910
3911 void
3912 cifs_umount(struct cifs_sb_info *cifs_sb)
3913 {
3914         struct rb_root *root = &cifs_sb->tlink_tree;
3915         struct rb_node *node;
3916         struct tcon_link *tlink;
3917
3918         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3919
3920         spin_lock(&cifs_sb->tlink_tree_lock);
3921         while ((node = rb_first(root))) {
3922                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3923                 cifs_get_tlink(tlink);
3924                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3925                 rb_erase(node, root);
3926
3927                 spin_unlock(&cifs_sb->tlink_tree_lock);
3928                 cifs_put_tlink(tlink);
3929                 spin_lock(&cifs_sb->tlink_tree_lock);
3930         }
3931         spin_unlock(&cifs_sb->tlink_tree_lock);
3932
3933         kfree(cifs_sb->prepath);
3934 #ifdef CONFIG_CIFS_DFS_UPCALL
3935         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3936 #endif
3937         call_rcu(&cifs_sb->rcu, delayed_free);
3938 }
3939
3940 int
3941 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3942                         struct TCP_Server_Info *server)
3943 {
3944         int rc = 0;
3945
3946         if (!server->ops->need_neg || !server->ops->negotiate)
3947                 return -ENOSYS;
3948
3949         /* only send once per connect */
3950         spin_lock(&cifs_tcp_ses_lock);
3951         if (!server->ops->need_neg(server) ||
3952             server->tcpStatus != CifsNeedNegotiate) {
3953                 spin_unlock(&cifs_tcp_ses_lock);
3954                 return 0;
3955         }
3956         server->tcpStatus = CifsInNegotiate;
3957         spin_unlock(&cifs_tcp_ses_lock);
3958
3959         rc = server->ops->negotiate(xid, ses, server);
3960         if (rc == 0) {
3961                 spin_lock(&cifs_tcp_ses_lock);
3962                 if (server->tcpStatus == CifsInNegotiate)
3963                         server->tcpStatus = CifsNeedSessSetup;
3964                 else
3965                         rc = -EHOSTDOWN;
3966                 spin_unlock(&cifs_tcp_ses_lock);
3967         } else {
3968                 spin_lock(&cifs_tcp_ses_lock);
3969                 if (server->tcpStatus == CifsInNegotiate)
3970                         server->tcpStatus = CifsNeedNegotiate;
3971                 spin_unlock(&cifs_tcp_ses_lock);
3972         }
3973
3974         return rc;
3975 }
3976
3977 int
3978 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3979                    struct TCP_Server_Info *server,
3980                    struct nls_table *nls_info)
3981 {
3982         int rc = -ENOSYS;
3983         bool is_binding = false;
3984
3985         /* only send once per connect */
3986         spin_lock(&cifs_tcp_ses_lock);
3987         if ((server->tcpStatus != CifsNeedSessSetup) &&
3988             (ses->status == CifsGood)) {
3989                 spin_unlock(&cifs_tcp_ses_lock);
3990                 return 0;
3991         }
3992         server->tcpStatus = CifsInSessSetup;
3993         spin_unlock(&cifs_tcp_ses_lock);
3994
3995         spin_lock(&ses->chan_lock);
3996         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3997         spin_unlock(&ses->chan_lock);
3998
3999         if (!is_binding) {
4000                 ses->capabilities = server->capabilities;
4001                 if (!linuxExtEnabled)
4002                         ses->capabilities &= (~server->vals->cap_unix);
4003
4004                 if (ses->auth_key.response) {
4005                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
4006                                  ses->auth_key.response);
4007                         kfree(ses->auth_key.response);
4008                         ses->auth_key.response = NULL;
4009                         ses->auth_key.len = 0;
4010                 }
4011         }
4012
4013         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
4014                  server->sec_mode, server->capabilities, server->timeAdj);
4015
4016         if (server->ops->sess_setup)
4017                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
4018
4019         if (rc) {
4020                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4021                 spin_lock(&cifs_tcp_ses_lock);
4022                 if (server->tcpStatus == CifsInSessSetup)
4023                         server->tcpStatus = CifsNeedSessSetup;
4024                 spin_unlock(&cifs_tcp_ses_lock);
4025         } else {
4026                 spin_lock(&cifs_tcp_ses_lock);
4027                 if (server->tcpStatus == CifsInSessSetup)
4028                         server->tcpStatus = CifsGood;
4029                 /* Even if one channel is active, session is in good state */
4030                 ses->status = CifsGood;
4031                 spin_unlock(&cifs_tcp_ses_lock);
4032
4033                 spin_lock(&ses->chan_lock);
4034                 cifs_chan_clear_need_reconnect(ses, server);
4035                 spin_unlock(&ses->chan_lock);
4036         }
4037
4038         return rc;
4039 }
4040
4041 static int
4042 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4043 {
4044         ctx->sectype = ses->sectype;
4045
4046         /* krb5 is special, since we don't need username or pw */
4047         if (ctx->sectype == Kerberos)
4048                 return 0;
4049
4050         return cifs_set_cifscreds(ctx, ses);
4051 }
4052
4053 static struct cifs_tcon *
4054 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4055 {
4056         int rc;
4057         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4058         struct cifs_ses *ses;
4059         struct cifs_tcon *tcon = NULL;
4060         struct smb3_fs_context *ctx;
4061
4062         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4063         if (ctx == NULL)
4064                 return ERR_PTR(-ENOMEM);
4065
4066         ctx->local_nls = cifs_sb->local_nls;
4067         ctx->linux_uid = fsuid;
4068         ctx->cred_uid = fsuid;
4069         ctx->UNC = master_tcon->treeName;
4070         ctx->retry = master_tcon->retry;
4071         ctx->nocase = master_tcon->nocase;
4072         ctx->nohandlecache = master_tcon->nohandlecache;
4073         ctx->local_lease = master_tcon->local_lease;
4074         ctx->no_lease = master_tcon->no_lease;
4075         ctx->resilient = master_tcon->use_resilient;
4076         ctx->persistent = master_tcon->use_persistent;
4077         ctx->handle_timeout = master_tcon->handle_timeout;
4078         ctx->no_linux_ext = !master_tcon->unix_ext;
4079         ctx->linux_ext = master_tcon->posix_extensions;
4080         ctx->sectype = master_tcon->ses->sectype;
4081         ctx->sign = master_tcon->ses->sign;
4082         ctx->seal = master_tcon->seal;
4083         ctx->witness = master_tcon->use_witness;
4084
4085         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4086         if (rc) {
4087                 tcon = ERR_PTR(rc);
4088                 goto out;
4089         }
4090
4091         /* get a reference for the same TCP session */
4092         spin_lock(&cifs_tcp_ses_lock);
4093         ++master_tcon->ses->server->srv_count;
4094         spin_unlock(&cifs_tcp_ses_lock);
4095
4096         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4097         if (IS_ERR(ses)) {
4098                 tcon = (struct cifs_tcon *)ses;
4099                 cifs_put_tcp_session(master_tcon->ses->server, 0);
4100                 goto out;
4101         }
4102
4103         tcon = cifs_get_tcon(ses, ctx);
4104         if (IS_ERR(tcon)) {
4105                 cifs_put_smb_ses(ses);
4106                 goto out;
4107         }
4108
4109         if (cap_unix(ses))
4110                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4111
4112 out:
4113         kfree(ctx->username);
4114         kfree_sensitive(ctx->password);
4115         kfree(ctx);
4116
4117         return tcon;
4118 }
4119
4120 struct cifs_tcon *
4121 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4122 {
4123         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4124 }
4125
4126 /* find and return a tlink with given uid */
4127 static struct tcon_link *
4128 tlink_rb_search(struct rb_root *root, kuid_t uid)
4129 {
4130         struct rb_node *node = root->rb_node;
4131         struct tcon_link *tlink;
4132
4133         while (node) {
4134                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4135
4136                 if (uid_gt(tlink->tl_uid, uid))
4137                         node = node->rb_left;
4138                 else if (uid_lt(tlink->tl_uid, uid))
4139                         node = node->rb_right;
4140                 else
4141                         return tlink;
4142         }
4143         return NULL;
4144 }
4145
4146 /* insert a tcon_link into the tree */
4147 static void
4148 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4149 {
4150         struct rb_node **new = &(root->rb_node), *parent = NULL;
4151         struct tcon_link *tlink;
4152
4153         while (*new) {
4154                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4155                 parent = *new;
4156
4157                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4158                         new = &((*new)->rb_left);
4159                 else
4160                         new = &((*new)->rb_right);
4161         }
4162
4163         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4164         rb_insert_color(&new_tlink->tl_rbnode, root);
4165 }
4166
4167 /*
4168  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4169  * current task.
4170  *
4171  * If the superblock doesn't refer to a multiuser mount, then just return
4172  * the master tcon for the mount.
4173  *
4174  * First, search the rbtree for an existing tcon for this fsuid. If one
4175  * exists, then check to see if it's pending construction. If it is then wait
4176  * for construction to complete. Once it's no longer pending, check to see if
4177  * it failed and either return an error or retry construction, depending on
4178  * the timeout.
4179  *
4180  * If one doesn't exist then insert a new tcon_link struct into the tree and
4181  * try to construct a new one.
4182  */
4183 struct tcon_link *
4184 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4185 {
4186         int ret;
4187         kuid_t fsuid = current_fsuid();
4188         struct tcon_link *tlink, *newtlink;
4189
4190         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4191                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4192
4193         spin_lock(&cifs_sb->tlink_tree_lock);
4194         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4195         if (tlink)
4196                 cifs_get_tlink(tlink);
4197         spin_unlock(&cifs_sb->tlink_tree_lock);
4198
4199         if (tlink == NULL) {
4200                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4201                 if (newtlink == NULL)
4202                         return ERR_PTR(-ENOMEM);
4203                 newtlink->tl_uid = fsuid;
4204                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4205                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4206                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4207                 cifs_get_tlink(newtlink);
4208
4209                 spin_lock(&cifs_sb->tlink_tree_lock);
4210                 /* was one inserted after previous search? */
4211                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4212                 if (tlink) {
4213                         cifs_get_tlink(tlink);
4214                         spin_unlock(&cifs_sb->tlink_tree_lock);
4215                         kfree(newtlink);
4216                         goto wait_for_construction;
4217                 }
4218                 tlink = newtlink;
4219                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4220                 spin_unlock(&cifs_sb->tlink_tree_lock);
4221         } else {
4222 wait_for_construction:
4223                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4224                                   TASK_INTERRUPTIBLE);
4225                 if (ret) {
4226                         cifs_put_tlink(tlink);
4227                         return ERR_PTR(-ERESTARTSYS);
4228                 }
4229
4230                 /* if it's good, return it */
4231                 if (!IS_ERR(tlink->tl_tcon))
4232                         return tlink;
4233
4234                 /* return error if we tried this already recently */
4235                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4236                         cifs_put_tlink(tlink);
4237                         return ERR_PTR(-EACCES);
4238                 }
4239
4240                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4241                         goto wait_for_construction;
4242         }
4243
4244         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4245         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4246         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4247
4248         if (IS_ERR(tlink->tl_tcon)) {
4249                 cifs_put_tlink(tlink);
4250                 return ERR_PTR(-EACCES);
4251         }
4252
4253         return tlink;
4254 }
4255
4256 /*
4257  * periodic workqueue job that scans tcon_tree for a superblock and closes
4258  * out tcons.
4259  */
4260 static void
4261 cifs_prune_tlinks(struct work_struct *work)
4262 {
4263         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4264                                                     prune_tlinks.work);
4265         struct rb_root *root = &cifs_sb->tlink_tree;
4266         struct rb_node *node;
4267         struct rb_node *tmp;
4268         struct tcon_link *tlink;
4269
4270         /*
4271          * Because we drop the spinlock in the loop in order to put the tlink
4272          * it's not guarded against removal of links from the tree. The only
4273          * places that remove entries from the tree are this function and
4274          * umounts. Because this function is non-reentrant and is canceled
4275          * before umount can proceed, this is safe.
4276          */
4277         spin_lock(&cifs_sb->tlink_tree_lock);
4278         node = rb_first(root);
4279         while (node != NULL) {
4280                 tmp = node;
4281                 node = rb_next(tmp);
4282                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4283
4284                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4285                     atomic_read(&tlink->tl_count) != 0 ||
4286                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4287                         continue;
4288
4289                 cifs_get_tlink(tlink);
4290                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4291                 rb_erase(tmp, root);
4292
4293                 spin_unlock(&cifs_sb->tlink_tree_lock);
4294                 cifs_put_tlink(tlink);
4295                 spin_lock(&cifs_sb->tlink_tree_lock);
4296         }
4297         spin_unlock(&cifs_sb->tlink_tree_lock);
4298
4299         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4300                                 TLINK_IDLE_EXPIRE);
4301 }
4302
4303 #ifdef CONFIG_CIFS_DFS_UPCALL
4304 /* Update dfs referral path of superblock */
4305 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4306                                   const char *target)
4307 {
4308         int rc = 0;
4309         size_t len = strlen(target);
4310         char *refpath, *npath;
4311
4312         if (unlikely(len < 2 || *target != '\\'))
4313                 return -EINVAL;
4314
4315         if (target[1] == '\\') {
4316                 len += 1;
4317                 refpath = kmalloc(len, GFP_KERNEL);
4318                 if (!refpath)
4319                         return -ENOMEM;
4320
4321                 scnprintf(refpath, len, "%s", target);
4322         } else {
4323                 len += sizeof("\\");
4324                 refpath = kmalloc(len, GFP_KERNEL);
4325                 if (!refpath)
4326                         return -ENOMEM;
4327
4328                 scnprintf(refpath, len, "\\%s", target);
4329         }
4330
4331         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4332         kfree(refpath);
4333
4334         if (IS_ERR(npath)) {
4335                 rc = PTR_ERR(npath);
4336         } else {
4337                 mutex_lock(&server->refpath_lock);
4338                 kfree(server->leaf_fullpath);
4339                 server->leaf_fullpath = npath;
4340                 mutex_unlock(&server->refpath_lock);
4341                 server->current_fullpath = server->leaf_fullpath;
4342         }
4343         return rc;
4344 }
4345
4346 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4347                                        size_t tcp_host_len, char *share, bool *target_match)
4348 {
4349         int rc = 0;
4350         const char *dfs_host;
4351         size_t dfs_host_len;
4352
4353         *target_match = true;
4354         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4355
4356         /* Check if hostnames or addresses match */
4357         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4358                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4359                          dfs_host, (int)tcp_host_len, tcp_host);
4360                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4361                 if (rc)
4362                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4363         }
4364         return rc;
4365 }
4366
4367 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4368                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4369                                      struct dfs_cache_tgt_list *tl)
4370 {
4371         int rc;
4372         struct TCP_Server_Info *server = tcon->ses->server;
4373         const struct smb_version_operations *ops = server->ops;
4374         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4375         char *share = NULL, *prefix = NULL;
4376         const char *tcp_host;
4377         size_t tcp_host_len;
4378         struct dfs_cache_tgt_iterator *tit;
4379         bool target_match;
4380
4381         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4382
4383         tit = dfs_cache_get_tgt_iterator(tl);
4384         if (!tit) {
4385                 rc = -ENOENT;
4386                 goto out;
4387         }
4388
4389         /* Try to tree connect to all dfs targets */
4390         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4391                 const char *target = dfs_cache_get_tgt_name(tit);
4392                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4393
4394                 kfree(share);
4395                 kfree(prefix);
4396                 share = prefix = NULL;
4397
4398                 /* Check if share matches with tcp ses */
4399                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4400                 if (rc) {
4401                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4402                         break;
4403                 }
4404
4405                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4406                                                  &target_match);
4407                 if (rc)
4408                         break;
4409                 if (!target_match) {
4410                         rc = -EHOSTUNREACH;
4411                         continue;
4412                 }
4413
4414                 if (ipc->need_reconnect) {
4415                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4416                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4417                         if (rc)
4418                                 break;
4419                 }
4420
4421                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4422                 if (!islink) {
4423                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4424                         break;
4425                 }
4426                 /*
4427                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4428                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4429                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4430                  * newly resolved target.
4431                  */
4432                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4433                                    NULL, &ntl)) {
4434                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4435                         if (rc)
4436                                 continue;
4437                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4438                         if (!rc)
4439                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4440                 } else {
4441                         /* Target is another dfs share */
4442                         rc = update_server_fullpath(server, cifs_sb, target);
4443                         dfs_cache_free_tgts(tl);
4444
4445                         if (!rc) {
4446                                 rc = -EREMOTE;
4447                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4448                         } else
4449                                 dfs_cache_free_tgts(&ntl);
4450                 }
4451                 break;
4452         }
4453
4454 out:
4455         kfree(share);
4456         kfree(prefix);
4457
4458         return rc;
4459 }
4460
4461 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4462                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4463                                    struct dfs_cache_tgt_list *tl)
4464 {
4465         int rc;
4466         int num_links = 0;
4467         struct TCP_Server_Info *server = tcon->ses->server;
4468
4469         do {
4470                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4471                 if (!rc || rc != -EREMOTE)
4472                         break;
4473         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4474         /*
4475          * If we couldn't tree connect to any targets from last referral path, then retry from
4476          * original referral path.
4477          */
4478         if (rc && server->current_fullpath != server->origin_fullpath) {
4479                 server->current_fullpath = server->origin_fullpath;
4480                 cifs_signal_cifsd_for_reconnect(server, true);
4481         }
4482
4483         dfs_cache_free_tgts(tl);
4484         return rc;
4485 }
4486
4487 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4488 {
4489         int rc;
4490         struct TCP_Server_Info *server = tcon->ses->server;
4491         const struct smb_version_operations *ops = server->ops;
4492         struct super_block *sb = NULL;
4493         struct cifs_sb_info *cifs_sb;
4494         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4495         char *tree;
4496         struct dfs_info3_param ref = {0};
4497
4498         /* only send once per connect */
4499         spin_lock(&cifs_tcp_ses_lock);
4500         if (tcon->ses->status != CifsGood ||
4501             (tcon->status != TID_NEW &&
4502             tcon->status != TID_NEED_TCON)) {
4503                 spin_unlock(&cifs_tcp_ses_lock);
4504                 return 0;
4505         }
4506         tcon->status = TID_IN_TCON;
4507         spin_unlock(&cifs_tcp_ses_lock);
4508
4509         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4510         if (!tree) {
4511                 rc = -ENOMEM;
4512                 goto out;
4513         }
4514
4515         if (tcon->ipc) {
4516                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4517                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4518                 goto out;
4519         }
4520
4521         sb = cifs_get_tcp_super(server);
4522         if (IS_ERR(sb)) {
4523                 rc = PTR_ERR(sb);
4524                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4525                 goto out;
4526         }
4527
4528         cifs_sb = CIFS_SB(sb);
4529
4530         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4531         if (!server->current_fullpath ||
4532             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4533                 rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls);
4534                 goto out;
4535         }
4536
4537         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4538                                      &tl);
4539         free_dfs_info_param(&ref);
4540
4541 out:
4542         kfree(tree);
4543         cifs_put_tcp_super(sb);
4544
4545         if (rc) {
4546                 spin_lock(&cifs_tcp_ses_lock);
4547                 if (tcon->status == TID_IN_TCON)
4548                         tcon->status = TID_NEED_TCON;
4549                 spin_unlock(&cifs_tcp_ses_lock);
4550         } else {
4551                 spin_lock(&cifs_tcp_ses_lock);
4552                 if (tcon->status == TID_IN_TCON)
4553                         tcon->status = TID_GOOD;
4554                 spin_unlock(&cifs_tcp_ses_lock);
4555                 tcon->need_reconnect = false;
4556         }
4557
4558         return rc;
4559 }
4560 #else
4561 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4562 {
4563         int rc;
4564         const struct smb_version_operations *ops = tcon->ses->server->ops;
4565
4566         /* only send once per connect */
4567         spin_lock(&cifs_tcp_ses_lock);
4568         if (tcon->ses->status != CifsGood ||
4569             (tcon->status != TID_NEW &&
4570             tcon->status != TID_NEED_TCON)) {
4571                 spin_unlock(&cifs_tcp_ses_lock);
4572                 return 0;
4573         }
4574         tcon->status = TID_IN_TCON;
4575         spin_unlock(&cifs_tcp_ses_lock);
4576
4577         rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4578         if (rc) {
4579                 spin_lock(&cifs_tcp_ses_lock);
4580                 if (tcon->status == TID_IN_TCON)
4581                         tcon->status = TID_NEED_TCON;
4582                 spin_unlock(&cifs_tcp_ses_lock);
4583         } else {
4584                 spin_lock(&cifs_tcp_ses_lock);
4585                 if (tcon->status == TID_IN_TCON)
4586                         tcon->status = TID_GOOD;
4587                 spin_unlock(&cifs_tcp_ses_lock);
4588                 tcon->need_reconnect = false;
4589         }
4590
4591         return rc;
4592 }
4593 #endif