fs/cifs/connect.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/net.h>
  10 #include <linux/string.h>
  11 #include <linux/sched/mm.h>
  12 #include <linux/sched/signal.h>
  13 #include <linux/list.h>
  14 #include <linux/wait.h>
  15 #include <linux/slab.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/ctype.h>
  18 #include <linux/utsname.h>
  19 #include <linux/mempool.h>
  20 #include <linux/delay.h>
  21 #include <linux/completion.h>
  22 #include <linux/kthread.h>
  23 #include <linux/pagevec.h>
  24 #include <linux/freezer.h>
  25 #include <linux/namei.h>
  26 #include <linux/uuid.h>
  27 #include <linux/uaccess.h>
  28 #include <asm/processor.h>
  29 #include <linux/inet.h>
  30 #include <linux/module.h>
  31 #include <keys/user-type.h>
  32 #include <net/ipv6.h>
  33 #include <linux/parser.h>
  34 #include <linux/bvec.h>
  35 #include "cifspdu.h"
  36 #include "cifsglob.h"
  37 #include "cifsproto.h"
  38 #include "cifs_unicode.h"
  39 #include "cifs_debug.h"
  40 #include "cifs_fs_sb.h"
  41 #include "ntlmssp.h"
  42 #include "nterr.h"
  43 #include "rfc1002pdu.h"
  44 #include "fscache.h"
  45 #include "smb2proto.h"
  46 #include "smbdirect.h"
  47 #include "dns_resolve.h"
  48 #ifdef CONFIG_CIFS_DFS_UPCALL
  49 #include "dfs_cache.h"
  50 #endif
  51 #include "fs_context.h"
  52 #include "cifs_swn.h"
  53
  54 extern mempool_t *cifs_req_poolp;
  55 extern bool disable_legacy_dialects;
  56
  57 /* FIXME: should these be tunable? */
  58 #define TLINK_ERROR_EXPIRE      (1 * HZ)
  59 #define TLINK_IDLE_EXPIRE       (600 * HZ)
  60
  61 /* Drop the connection to not overload the server */
  62 #define NUM_STATUS_IO_TIMEOUT   5
  63
  64 struct mount_ctx {
  65         struct cifs_sb_info *cifs_sb;
  66         struct smb3_fs_context *fs_ctx;
  67         unsigned int xid;
  68         struct TCP_Server_Info *server;
  69         struct cifs_ses *ses;
  70         struct cifs_tcon *tcon;
  71 #ifdef CONFIG_CIFS_DFS_UPCALL
  72         struct cifs_ses *root_ses;
  73         uuid_t mount_id;
  74         char *origin_fullpath, *leaf_fullpath;
  75 #endif
  76 };
  77
  78 static int ip_connect(struct TCP_Server_Info *server);
  79 static int generic_ip_connect(struct TCP_Server_Info *server);
  80 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  81 static void cifs_prune_tlinks(struct work_struct *work);
  82
  83 /*
  84  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  85  * get their ip addresses changed at some point.
  86  *
  87  * This should be called with server->srv_mutex held.
  88  */
  89 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  90 {
  91         int rc;
  92         int len;
  93         char *unc, *ipaddr = NULL;
  94         time64_t expiry, now;
  95         unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  96
  97         if (!server->hostname)
  98                 return -EINVAL;
  99
 100         len = strlen(server->hostname) + 3;
 101
 102         unc = kmalloc(len, GFP_KERNEL);
 103         if (!unc) {
 104                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
 105                 return -ENOMEM;
 106         }
 107         scnprintf(unc, len, "\\\\%s", server->hostname);
 108
 109         rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
 110         kfree(unc);
 111
 112         if (rc < 0) {
 113                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 114                          __func__, server->hostname, rc);
 115                 goto requeue_resolve;
 116         }
 117
 118         spin_lock(&cifs_tcp_ses_lock);
 119         rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 120                                   strlen(ipaddr));
 121         spin_unlock(&cifs_tcp_ses_lock);
 122         kfree(ipaddr);
 123
 124         /* rc == 1 means success here */
 125         if (rc) {
 126                 now = ktime_get_real_seconds();
 127                 if (expiry && expiry > now)
 128                         /*
 129                          * To make sure we don't use the cached entry, retry 1s
 130                          * after expiry.
 131                          */
 132                         ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 133         }
 134         rc = !rc ? -1 : 0;
 135
 136 requeue_resolve:
 137         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 138                  __func__, ttl);
 139         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 140
 141         return rc;
 142 }
 143
 144
 145 static void cifs_resolve_server(struct work_struct *work)
 146 {
 147         int rc;
 148         struct TCP_Server_Info *server = container_of(work,
 149                                         struct TCP_Server_Info, resolve.work);
 150
 151         cifs_server_lock(server);
 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         cifs_server_unlock(server);
 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->ses_status = SES_NEED_RECON;
 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         cifs_server_lock(server);
 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         cifs_server_unlock(server);
 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                 cifs_server_lock(server);
 310                 smbd_destroy(server);
 311                 cifs_server_unlock(server);
 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                 cifs_server_lock(server);
 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                         cifs_server_unlock(server);
 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                         cifs_server_unlock(server);
 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                 cifs_server_lock(server);
 492
 493                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 494                 if (rc) {
 495                         /* Failed to reconnect socket */
 496                         cifs_server_unlock(server);
 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                 cifs_server_unlock(server);
 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=0x%x\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->ses_status == SES_EXITING)
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
1849         spin_lock(&cifs_tcp_ses_lock);
1850         if (ses->ses_status == SES_EXITING) {
1851                 spin_unlock(&cifs_tcp_ses_lock);
1852                 return;
1853         }
1854
1855         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1856         cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE");
1857
1858         if (--ses->ses_count > 0) {
1859                 spin_unlock(&cifs_tcp_ses_lock);
1860                 return;
1861         }
1862
1863         /* ses_count can never go negative */
1864         WARN_ON(ses->ses_count < 0);
1865
1866         if (ses->ses_status == SES_GOOD)
1867                 ses->ses_status = SES_EXITING;
1868         spin_unlock(&cifs_tcp_ses_lock);
1869
1870         cifs_free_ipc(ses);
1871
1872         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1873                 xid = get_xid();
1874                 rc = server->ops->logoff(xid, ses);
1875                 if (rc)
1876                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1877                                 __func__, rc);
1878                 _free_xid(xid);
1879         }
1880
1881         spin_lock(&cifs_tcp_ses_lock);
1882         list_del_init(&ses->smb_ses_list);
1883         spin_unlock(&cifs_tcp_ses_lock);
1884
1885         spin_lock(&ses->chan_lock);
1886         chan_count = ses->chan_count;
1887
1888         /* close any extra channels */
1889         if (chan_count > 1) {
1890                 int i;
1891
1892                 for (i = 1; i < chan_count; i++) {
1893                         spin_unlock(&ses->chan_lock);
1894                         cifs_put_tcp_session(ses->chans[i].server, 0);
1895                         spin_lock(&ses->chan_lock);
1896                         ses->chans[i].server = NULL;
1897                 }
1898         }
1899         spin_unlock(&ses->chan_lock);
1900
1901         sesInfoFree(ses);
1902         cifs_put_tcp_session(server, 0);
1903 }
1904
1905 #ifdef CONFIG_KEYS
1906
1907 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1908 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1909
1910 /* Populate username and pw fields from keyring if possible */
1911 static int
1912 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1913 {
1914         int rc = 0;
1915         int is_domain = 0;
1916         const char *delim, *payload;
1917         char *desc;
1918         ssize_t len;
1919         struct key *key;
1920         struct TCP_Server_Info *server = ses->server;
1921         struct sockaddr_in *sa;
1922         struct sockaddr_in6 *sa6;
1923         const struct user_key_payload *upayload;
1924
1925         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1926         if (!desc)
1927                 return -ENOMEM;
1928
1929         /* try to find an address key first */
1930         switch (server->dstaddr.ss_family) {
1931         case AF_INET:
1932                 sa = (struct sockaddr_in *)&server->dstaddr;
1933                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1934                 break;
1935         case AF_INET6:
1936                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1937                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1938                 break;
1939         default:
1940                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1941                          server->dstaddr.ss_family);
1942                 rc = -EINVAL;
1943                 goto out_err;
1944         }
1945
1946         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1947         key = request_key(&key_type_logon, desc, "");
1948         if (IS_ERR(key)) {
1949                 if (!ses->domainName) {
1950                         cifs_dbg(FYI, "domainName is NULL\n");
1951                         rc = PTR_ERR(key);
1952                         goto out_err;
1953                 }
1954
1955                 /* didn't work, try to find a domain key */
1956                 sprintf(desc, "cifs:d:%s", ses->domainName);
1957                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1958                 key = request_key(&key_type_logon, desc, "");
1959                 if (IS_ERR(key)) {
1960                         rc = PTR_ERR(key);
1961                         goto out_err;
1962                 }
1963                 is_domain = 1;
1964         }
1965
1966         down_read(&key->sem);
1967         upayload = user_key_payload_locked(key);
1968         if (IS_ERR_OR_NULL(upayload)) {
1969                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1970                 goto out_key_put;
1971         }
1972
1973         /* find first : in payload */
1974         payload = upayload->data;
1975         delim = strnchr(payload, upayload->datalen, ':');
1976         cifs_dbg(FYI, "payload=%s\n", payload);
1977         if (!delim) {
1978                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1979                          upayload->datalen);
1980                 rc = -EINVAL;
1981                 goto out_key_put;
1982         }
1983
1984         len = delim - payload;
1985         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1986                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1987                          len);
1988                 rc = -EINVAL;
1989                 goto out_key_put;
1990         }
1991
1992         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1993         if (!ctx->username) {
1994                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1995                          len);
1996                 rc = -ENOMEM;
1997                 goto out_key_put;
1998         }
1999         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2000
2001         len = key->datalen - (len + 1);
2002         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2003                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2004                 rc = -EINVAL;
2005                 kfree(ctx->username);
2006                 ctx->username = NULL;
2007                 goto out_key_put;
2008         }
2009
2010         ++delim;
2011         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2012         if (!ctx->password) {
2013                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2014                          len);
2015                 rc = -ENOMEM;
2016                 kfree(ctx->username);
2017                 ctx->username = NULL;
2018                 goto out_key_put;
2019         }
2020
2021         /*
2022          * If we have a domain key then we must set the domainName in the
2023          * for the request.
2024          */
2025         if (is_domain && ses->domainName) {
2026                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2027                 if (!ctx->domainname) {
2028                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2029                                  len);
2030                         rc = -ENOMEM;
2031                         kfree(ctx->username);
2032                         ctx->username = NULL;
2033                         kfree_sensitive(ctx->password);
2034                         ctx->password = NULL;
2035                         goto out_key_put;
2036                 }
2037         }
2038
2039         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2040
2041 out_key_put:
2042         up_read(&key->sem);
2043         key_put(key);
2044 out_err:
2045         kfree(desc);
2046         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2047         return rc;
2048 }
2049 #else /* ! CONFIG_KEYS */
2050 static inline int
2051 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2052                    struct cifs_ses *ses __attribute__((unused)))
2053 {
2054         return -ENOSYS;
2055 }
2056 #endif /* CONFIG_KEYS */
2057
2058 /**
2059  * cifs_get_smb_ses - get a session matching @ctx data from @server
2060  * @server: server to setup the session to
2061  * @ctx: superblock configuration context to use to setup the session
2062  *
2063  * This function assumes it is being called from cifs_mount() where we
2064  * already got a server reference (server refcount +1). See
2065  * cifs_get_tcon() for refcount explanations.
2066  */
2067 struct cifs_ses *
2068 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2069 {
2070         int rc = -ENOMEM;
2071         unsigned int xid;
2072         struct cifs_ses *ses;
2073         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2074         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2075
2076         xid = get_xid();
2077
2078         ses = cifs_find_smb_ses(server, ctx);
2079         if (ses) {
2080                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2081                          ses->ses_status);
2082
2083                 spin_lock(&ses->chan_lock);
2084                 if (cifs_chan_needs_reconnect(ses, server)) {
2085                         spin_unlock(&ses->chan_lock);
2086                         cifs_dbg(FYI, "Session needs reconnect\n");
2087
2088                         mutex_lock(&ses->session_mutex);
2089                         rc = cifs_negotiate_protocol(xid, ses, server);
2090                         if (rc) {
2091                                 mutex_unlock(&ses->session_mutex);
2092                                 /* problem -- put our ses reference */
2093                                 cifs_put_smb_ses(ses);
2094                                 free_xid(xid);
2095                                 return ERR_PTR(rc);
2096                         }
2097
2098                         rc = cifs_setup_session(xid, ses, server,
2099                                                 ctx->local_nls);
2100                         if (rc) {
2101                                 mutex_unlock(&ses->session_mutex);
2102                                 /* problem -- put our reference */
2103                                 cifs_put_smb_ses(ses);
2104                                 free_xid(xid);
2105                                 return ERR_PTR(rc);
2106                         }
2107                         mutex_unlock(&ses->session_mutex);
2108
2109                         spin_lock(&ses->chan_lock);
2110                 }
2111                 spin_unlock(&ses->chan_lock);
2112
2113                 /* existing SMB ses has a server reference already */
2114                 cifs_put_tcp_session(server, 0);
2115                 free_xid(xid);
2116                 return ses;
2117         }
2118
2119         cifs_dbg(FYI, "Existing smb sess not found\n");
2120         ses = sesInfoAlloc();
2121         if (ses == NULL)
2122                 goto get_ses_fail;
2123
2124         /* new SMB session uses our server ref */
2125         ses->server = server;
2126         if (server->dstaddr.ss_family == AF_INET6)
2127                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2128         else
2129                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2130
2131         if (ctx->username) {
2132                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2133                 if (!ses->user_name)
2134                         goto get_ses_fail;
2135         }
2136
2137         /* ctx->password freed at unmount */
2138         if (ctx->password) {
2139                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2140                 if (!ses->password)
2141                         goto get_ses_fail;
2142         }
2143         if (ctx->domainname) {
2144                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2145                 if (!ses->domainName)
2146                         goto get_ses_fail;
2147         }
2148
2149         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2150
2151         if (ctx->domainauto)
2152                 ses->domainAuto = ctx->domainauto;
2153         ses->cred_uid = ctx->cred_uid;
2154         ses->linux_uid = ctx->linux_uid;
2155
2156         ses->sectype = ctx->sectype;
2157         ses->sign = ctx->sign;
2158
2159         /* add server as first channel */
2160         spin_lock(&ses->chan_lock);
2161         ses->chans[0].server = server;
2162         ses->chan_count = 1;
2163         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2164         ses->chans_need_reconnect = 1;
2165         spin_unlock(&ses->chan_lock);
2166
2167         mutex_lock(&ses->session_mutex);
2168         rc = cifs_negotiate_protocol(xid, ses, server);
2169         if (!rc)
2170                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2171         mutex_unlock(&ses->session_mutex);
2172
2173         /* each channel uses a different signing key */
2174         spin_lock(&ses->chan_lock);
2175         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2176                sizeof(ses->smb3signingkey));
2177         spin_unlock(&ses->chan_lock);
2178
2179         if (rc)
2180                 goto get_ses_fail;
2181
2182         /*
2183          * success, put it on the list and add it as first channel
2184          * note: the session becomes active soon after this. So you'll
2185          * need to lock before changing something in the session.
2186          */
2187         spin_lock(&cifs_tcp_ses_lock);
2188         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2189         spin_unlock(&cifs_tcp_ses_lock);
2190
2191         free_xid(xid);
2192
2193         cifs_setup_ipc(ses, ctx);
2194
2195         return ses;
2196
2197 get_ses_fail:
2198         sesInfoFree(ses);
2199         free_xid(xid);
2200         return ERR_PTR(rc);
2201 }
2202
2203 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2204 {
2205         if (tcon->status == TID_EXITING)
2206                 return 0;
2207         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
2208                 return 0;
2209         if (tcon->seal != ctx->seal)
2210                 return 0;
2211         if (tcon->snapshot_time != ctx->snapshot_time)
2212                 return 0;
2213         if (tcon->handle_timeout != ctx->handle_timeout)
2214                 return 0;
2215         if (tcon->no_lease != ctx->no_lease)
2216                 return 0;
2217         if (tcon->nodelete != ctx->nodelete)
2218                 return 0;
2219         return 1;
2220 }
2221
2222 static struct cifs_tcon *
2223 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2224 {
2225         struct list_head *tmp;
2226         struct cifs_tcon *tcon;
2227
2228         spin_lock(&cifs_tcp_ses_lock);
2229         list_for_each(tmp, &ses->tcon_list) {
2230                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
2231
2232                 if (!match_tcon(tcon, ctx))
2233                         continue;
2234                 ++tcon->tc_count;
2235                 spin_unlock(&cifs_tcp_ses_lock);
2236                 return tcon;
2237         }
2238         spin_unlock(&cifs_tcp_ses_lock);
2239         return NULL;
2240 }
2241
2242 void
2243 cifs_put_tcon(struct cifs_tcon *tcon)
2244 {
2245         unsigned int xid;
2246         struct cifs_ses *ses;
2247
2248         /*
2249          * IPC tcon share the lifetime of their session and are
2250          * destroyed in the session put function
2251          */
2252         if (tcon == NULL || tcon->ipc)
2253                 return;
2254
2255         ses = tcon->ses;
2256         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2257         spin_lock(&cifs_tcp_ses_lock);
2258         if (--tcon->tc_count > 0) {
2259                 spin_unlock(&cifs_tcp_ses_lock);
2260                 return;
2261         }
2262
2263         /* tc_count can never go negative */
2264         WARN_ON(tcon->tc_count < 0);
2265
2266         list_del_init(&tcon->tcon_list);
2267         spin_unlock(&cifs_tcp_ses_lock);
2268
2269         if (tcon->use_witness) {
2270                 int rc;
2271
2272                 rc = cifs_swn_unregister(tcon);
2273                 if (rc < 0) {
2274                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2275                                         __func__, rc);
2276                 }
2277         }
2278
2279         xid = get_xid();
2280         if (ses->server->ops->tree_disconnect)
2281                 ses->server->ops->tree_disconnect(xid, tcon);
2282         _free_xid(xid);
2283
2284         cifs_fscache_release_super_cookie(tcon);
2285         tconInfoFree(tcon);
2286         cifs_put_smb_ses(ses);
2287 }
2288
2289 /**
2290  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2291  * @ses: smb session to issue the request on
2292  * @ctx: the superblock configuration context to use for building the
2293  *
2294  * - tcon refcount is the number of mount points using the tcon.
2295  * - ses refcount is the number of tcon using the session.
2296  *
2297  * 1. This function assumes it is being called from cifs_mount() where
2298  *    we already got a session reference (ses refcount +1).
2299  *
2300  * 2. Since we're in the context of adding a mount point, the end
2301  *    result should be either:
2302  *
2303  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2304  *    its session refcount incremented (1 new tcon). This +1 was
2305  *    already done in (1).
2306  *
2307  * b) an existing tcon with refcount+1 (add a mount point to it) and
2308  *    identical ses refcount (no new tcon). Because of (1) we need to
2309  *    decrement the ses refcount.
2310  */
2311 static struct cifs_tcon *
2312 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2313 {
2314         int rc, xid;
2315         struct cifs_tcon *tcon;
2316
2317         tcon = cifs_find_tcon(ses, ctx);
2318         if (tcon) {
2319                 /*
2320                  * tcon has refcount already incremented but we need to
2321                  * decrement extra ses reference gotten by caller (case b)
2322                  */
2323                 cifs_dbg(FYI, "Found match on UNC path\n");
2324                 cifs_put_smb_ses(ses);
2325                 return tcon;
2326         }
2327
2328         if (!ses->server->ops->tree_connect) {
2329                 rc = -ENOSYS;
2330                 goto out_fail;
2331         }
2332
2333         tcon = tconInfoAlloc();
2334         if (tcon == NULL) {
2335                 rc = -ENOMEM;
2336                 goto out_fail;
2337         }
2338
2339         if (ctx->snapshot_time) {
2340                 if (ses->server->vals->protocol_id == 0) {
2341                         cifs_dbg(VFS,
2342                              "Use SMB2 or later for snapshot mount option\n");
2343                         rc = -EOPNOTSUPP;
2344                         goto out_fail;
2345                 } else
2346                         tcon->snapshot_time = ctx->snapshot_time;
2347         }
2348
2349         if (ctx->handle_timeout) {
2350                 if (ses->server->vals->protocol_id == 0) {
2351                         cifs_dbg(VFS,
2352                              "Use SMB2.1 or later for handle timeout option\n");
2353                         rc = -EOPNOTSUPP;
2354                         goto out_fail;
2355                 } else
2356                         tcon->handle_timeout = ctx->handle_timeout;
2357         }
2358
2359         tcon->ses = ses;
2360         if (ctx->password) {
2361                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2362                 if (!tcon->password) {
2363                         rc = -ENOMEM;
2364                         goto out_fail;
2365                 }
2366         }
2367
2368         if (ctx->seal) {
2369                 if (ses->server->vals->protocol_id == 0) {
2370                         cifs_dbg(VFS,
2371                                  "SMB3 or later required for encryption\n");
2372                         rc = -EOPNOTSUPP;
2373                         goto out_fail;
2374                 } else if (tcon->ses->server->capabilities &
2375                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2376                         tcon->seal = true;
2377                 else {
2378                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2379                         rc = -EOPNOTSUPP;
2380                         goto out_fail;
2381                 }
2382         }
2383
2384         if (ctx->linux_ext) {
2385                 if (ses->server->posix_ext_supported) {
2386                         tcon->posix_extensions = true;
2387                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2388                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2389                     (strcmp(ses->server->vals->version_string,
2390                      SMB3ANY_VERSION_STRING) == 0) ||
2391                     (strcmp(ses->server->vals->version_string,
2392                      SMBDEFAULT_VERSION_STRING) == 0)) {
2393                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2394                         rc = -EOPNOTSUPP;
2395                         goto out_fail;
2396                 } else {
2397                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2398                                 "disabled but required for POSIX extensions\n");
2399                         rc = -EOPNOTSUPP;
2400                         goto out_fail;
2401                 }
2402         }
2403
2404         xid = get_xid();
2405         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2406                                             ctx->local_nls);
2407         free_xid(xid);
2408         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2409         if (rc)
2410                 goto out_fail;
2411
2412         tcon->use_persistent = false;
2413         /* check if SMB2 or later, CIFS does not support persistent handles */
2414         if (ctx->persistent) {
2415                 if (ses->server->vals->protocol_id == 0) {
2416                         cifs_dbg(VFS,
2417                              "SMB3 or later required for persistent handles\n");
2418                         rc = -EOPNOTSUPP;
2419                         goto out_fail;
2420                 } else if (ses->server->capabilities &
2421                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2422                         tcon->use_persistent = true;
2423                 else /* persistent handles requested but not supported */ {
2424                         cifs_dbg(VFS,
2425                                 "Persistent handles not supported on share\n");
2426                         rc = -EOPNOTSUPP;
2427                         goto out_fail;
2428                 }
2429         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2430              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2431              && (ctx->nopersistent == false)) {
2432                 cifs_dbg(FYI, "enabling persistent handles\n");
2433                 tcon->use_persistent = true;
2434         } else if (ctx->resilient) {
2435                 if (ses->server->vals->protocol_id == 0) {
2436                         cifs_dbg(VFS,
2437                              "SMB2.1 or later required for resilient handles\n");
2438                         rc = -EOPNOTSUPP;
2439                         goto out_fail;
2440                 }
2441                 tcon->use_resilient = true;
2442         }
2443
2444         tcon->use_witness = false;
2445         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2446                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2447                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2448                                 /*
2449                                  * Set witness in use flag in first place
2450                                  * to retry registration in the echo task
2451                                  */
2452                                 tcon->use_witness = true;
2453                                 /* And try to register immediately */
2454                                 rc = cifs_swn_register(tcon);
2455                                 if (rc < 0) {
2456                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2457                                         goto out_fail;
2458                                 }
2459                         } else {
2460                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2461                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2462                                 rc = -EOPNOTSUPP;
2463                                 goto out_fail;
2464                         }
2465                 } else {
2466                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2467                         rc = -EOPNOTSUPP;
2468                         goto out_fail;
2469                 }
2470         }
2471
2472         /* If the user really knows what they are doing they can override */
2473         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2474                 if (ctx->cache_ro)
2475                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2476                 else if (ctx->cache_rw)
2477                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2478         }
2479
2480         if (ctx->no_lease) {
2481                 if (ses->server->vals->protocol_id == 0) {
2482                         cifs_dbg(VFS,
2483                                 "SMB2 or later required for nolease option\n");
2484                         rc = -EOPNOTSUPP;
2485                         goto out_fail;
2486                 } else
2487                         tcon->no_lease = ctx->no_lease;
2488         }
2489
2490         /*
2491          * We can have only one retry value for a connection to a share so for
2492          * resources mounted more than once to the same server share the last
2493          * value passed in for the retry flag is used.
2494          */
2495         tcon->retry = ctx->retry;
2496         tcon->nocase = ctx->nocase;
2497         tcon->broken_sparse_sup = ctx->no_sparse;
2498         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2499                 tcon->nohandlecache = ctx->nohandlecache;
2500         else
2501                 tcon->nohandlecache = true;
2502         tcon->nodelete = ctx->nodelete;
2503         tcon->local_lease = ctx->local_lease;
2504         INIT_LIST_HEAD(&tcon->pending_opens);
2505
2506         spin_lock(&cifs_tcp_ses_lock);
2507         list_add(&tcon->tcon_list, &ses->tcon_list);
2508         spin_unlock(&cifs_tcp_ses_lock);
2509
2510         return tcon;
2511
2512 out_fail:
2513         tconInfoFree(tcon);
2514         return ERR_PTR(rc);
2515 }
2516
2517 void
2518 cifs_put_tlink(struct tcon_link *tlink)
2519 {
2520         if (!tlink || IS_ERR(tlink))
2521                 return;
2522
2523         if (!atomic_dec_and_test(&tlink->tl_count) ||
2524             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2525                 tlink->tl_time = jiffies;
2526                 return;
2527         }
2528
2529         if (!IS_ERR(tlink_tcon(tlink)))
2530                 cifs_put_tcon(tlink_tcon(tlink));
2531         kfree(tlink);
2532         return;
2533 }
2534
2535 static int
2536 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2537 {
2538         struct cifs_sb_info *old = CIFS_SB(sb);
2539         struct cifs_sb_info *new = mnt_data->cifs_sb;
2540         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2541         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2542
2543         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2544                 return 0;
2545
2546         if (old->mnt_cifs_serverino_autodisabled)
2547                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2548
2549         if (oldflags != newflags)
2550                 return 0;
2551
2552         /*
2553          * We want to share sb only if we don't specify an r/wsize or
2554          * specified r/wsize is greater than or equal to existing one.
2555          */
2556         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2557                 return 0;
2558
2559         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2560                 return 0;
2561
2562         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2563             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2564                 return 0;
2565
2566         if (old->ctx->file_mode != new->ctx->file_mode ||
2567             old->ctx->dir_mode != new->ctx->dir_mode)
2568                 return 0;
2569
2570         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2571                 return 0;
2572
2573         if (old->ctx->acregmax != new->ctx->acregmax)
2574                 return 0;
2575         if (old->ctx->acdirmax != new->ctx->acdirmax)
2576                 return 0;
2577
2578         return 1;
2579 }
2580
2581 static int
2582 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2583 {
2584         struct cifs_sb_info *old = CIFS_SB(sb);
2585         struct cifs_sb_info *new = mnt_data->cifs_sb;
2586         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2587                 old->prepath;
2588         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2589                 new->prepath;
2590
2591         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2592                 return 1;
2593         else if (!old_set && !new_set)
2594                 return 1;
2595
2596         return 0;
2597 }
2598
2599 int
2600 cifs_match_super(struct super_block *sb, void *data)
2601 {
2602         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2603         struct smb3_fs_context *ctx;
2604         struct cifs_sb_info *cifs_sb;
2605         struct TCP_Server_Info *tcp_srv;
2606         struct cifs_ses *ses;
2607         struct cifs_tcon *tcon;
2608         struct tcon_link *tlink;
2609         int rc = 0;
2610
2611         spin_lock(&cifs_tcp_ses_lock);
2612         cifs_sb = CIFS_SB(sb);
2613         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2614         if (tlink == NULL) {
2615                 /* can not match superblock if tlink were ever null */
2616                 spin_unlock(&cifs_tcp_ses_lock);
2617                 return 0;
2618         }
2619         tcon = tlink_tcon(tlink);
2620         ses = tcon->ses;
2621         tcp_srv = ses->server;
2622
2623         ctx = mnt_data->ctx;
2624
2625         if (!match_server(tcp_srv, ctx) ||
2626             !match_session(ses, ctx) ||
2627             !match_tcon(tcon, ctx) ||
2628             !match_prepath(sb, mnt_data)) {
2629                 rc = 0;
2630                 goto out;
2631         }
2632
2633         rc = compare_mount_options(sb, mnt_data);
2634 out:
2635         spin_unlock(&cifs_tcp_ses_lock);
2636         cifs_put_tlink(tlink);
2637         return rc;
2638 }
2639
2640 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2641 static struct lock_class_key cifs_key[2];
2642 static struct lock_class_key cifs_slock_key[2];
2643
2644 static inline void
2645 cifs_reclassify_socket4(struct socket *sock)
2646 {
2647         struct sock *sk = sock->sk;
2648         BUG_ON(!sock_allow_reclassification(sk));
2649         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2650                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2651 }
2652
2653 static inline void
2654 cifs_reclassify_socket6(struct socket *sock)
2655 {
2656         struct sock *sk = sock->sk;
2657         BUG_ON(!sock_allow_reclassification(sk));
2658         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2659                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2660 }
2661 #else
2662 static inline void
2663 cifs_reclassify_socket4(struct socket *sock)
2664 {
2665 }
2666
2667 static inline void
2668 cifs_reclassify_socket6(struct socket *sock)
2669 {
2670 }
2671 #endif
2672
2673 /* See RFC1001 section 14 on representation of Netbios names */
2674 static void rfc1002mangle(char *target, char *source, unsigned int length)
2675 {
2676         unsigned int i, j;
2677
2678         for (i = 0, j = 0; i < (length); i++) {
2679                 /* mask a nibble at a time and encode */
2680                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2681                 target[j+1] = 'A' + (0x0F & source[i]);
2682                 j += 2;
2683         }
2684
2685 }
2686
2687 static int
2688 bind_socket(struct TCP_Server_Info *server)
2689 {
2690         int rc = 0;
2691         if (server->srcaddr.ss_family != AF_UNSPEC) {
2692                 /* Bind to the specified local IP address */
2693                 struct socket *socket = server->ssocket;
2694                 rc = socket->ops->bind(socket,
2695                                        (struct sockaddr *) &server->srcaddr,
2696                                        sizeof(server->srcaddr));
2697                 if (rc < 0) {
2698                         struct sockaddr_in *saddr4;
2699                         struct sockaddr_in6 *saddr6;
2700                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2701                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2702                         if (saddr6->sin6_family == AF_INET6)
2703                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2704                                          &saddr6->sin6_addr, rc);
2705                         else
2706                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2707                                          &saddr4->sin_addr.s_addr, rc);
2708                 }
2709         }
2710         return rc;
2711 }
2712
2713 static int
2714 ip_rfc1001_connect(struct TCP_Server_Info *server)
2715 {
2716         int rc = 0;
2717         /*
2718          * some servers require RFC1001 sessinit before sending
2719          * negprot - BB check reconnection in case where second
2720          * sessinit is sent but no second negprot
2721          */
2722         struct rfc1002_session_packet *ses_init_buf;
2723         struct smb_hdr *smb_buf;
2724         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2725                                GFP_KERNEL);
2726         if (ses_init_buf) {
2727                 ses_init_buf->trailer.session_req.called_len = 32;
2728
2729                 if (server->server_RFC1001_name[0] != 0)
2730                         rfc1002mangle(ses_init_buf->trailer.
2731                                       session_req.called_name,
2732                                       server->server_RFC1001_name,
2733                                       RFC1001_NAME_LEN_WITH_NULL);
2734                 else
2735                         rfc1002mangle(ses_init_buf->trailer.
2736                                       session_req.called_name,
2737                                       DEFAULT_CIFS_CALLED_NAME,
2738                                       RFC1001_NAME_LEN_WITH_NULL);
2739
2740                 ses_init_buf->trailer.session_req.calling_len = 32;
2741
2742                 /*
2743                  * calling name ends in null (byte 16) from old smb
2744                  * convention.
2745                  */
2746                 if (server->workstation_RFC1001_name[0] != 0)
2747                         rfc1002mangle(ses_init_buf->trailer.
2748                                       session_req.calling_name,
2749                                       server->workstation_RFC1001_name,
2750                                       RFC1001_NAME_LEN_WITH_NULL);
2751                 else
2752                         rfc1002mangle(ses_init_buf->trailer.
2753                                       session_req.calling_name,
2754                                       "LINUX_CIFS_CLNT",
2755                                       RFC1001_NAME_LEN_WITH_NULL);
2756
2757                 ses_init_buf->trailer.session_req.scope1 = 0;
2758                 ses_init_buf->trailer.session_req.scope2 = 0;
2759                 smb_buf = (struct smb_hdr *)ses_init_buf;
2760
2761                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2762                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2763                 rc = smb_send(server, smb_buf, 0x44);
2764                 kfree(ses_init_buf);
2765                 /*
2766                  * RFC1001 layer in at least one server
2767                  * requires very short break before negprot
2768                  * presumably because not expecting negprot
2769                  * to follow so fast.  This is a simple
2770                  * solution that works without
2771                  * complicating the code and causes no
2772                  * significant slowing down on mount
2773                  * for everyone else
2774                  */
2775                 usleep_range(1000, 2000);
2776         }
2777         /*
2778          * else the negprot may still work without this
2779          * even though malloc failed
2780          */
2781
2782         return rc;
2783 }
2784
2785 static int
2786 generic_ip_connect(struct TCP_Server_Info *server)
2787 {
2788         int rc = 0;
2789         __be16 sport;
2790         int slen, sfamily;
2791         struct socket *socket = server->ssocket;
2792         struct sockaddr *saddr;
2793
2794         saddr = (struct sockaddr *) &server->dstaddr;
2795
2796         if (server->dstaddr.ss_family == AF_INET6) {
2797                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2798
2799                 sport = ipv6->sin6_port;
2800                 slen = sizeof(struct sockaddr_in6);
2801                 sfamily = AF_INET6;
2802                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2803                                 ntohs(sport));
2804         } else {
2805                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2806
2807                 sport = ipv4->sin_port;
2808                 slen = sizeof(struct sockaddr_in);
2809                 sfamily = AF_INET;
2810                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2811                                 ntohs(sport));
2812         }
2813
2814         if (socket == NULL) {
2815                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2816                                    IPPROTO_TCP, &socket, 1);
2817                 if (rc < 0) {
2818                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2819                         server->ssocket = NULL;
2820                         return rc;
2821                 }
2822
2823                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2824                 cifs_dbg(FYI, "Socket created\n");
2825                 server->ssocket = socket;
2826                 socket->sk->sk_allocation = GFP_NOFS;
2827                 if (sfamily == AF_INET6)
2828                         cifs_reclassify_socket6(socket);
2829                 else
2830                         cifs_reclassify_socket4(socket);
2831         }
2832
2833         rc = bind_socket(server);
2834         if (rc < 0)
2835                 return rc;
2836
2837         /*
2838          * Eventually check for other socket options to change from
2839          * the default. sock_setsockopt not used because it expects
2840          * user space buffer
2841          */
2842         socket->sk->sk_rcvtimeo = 7 * HZ;
2843         socket->sk->sk_sndtimeo = 5 * HZ;
2844
2845         /* make the bufsizes depend on wsize/rsize and max requests */
2846         if (server->noautotune) {
2847                 if (socket->sk->sk_sndbuf < (200 * 1024))
2848                         socket->sk->sk_sndbuf = 200 * 1024;
2849                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2850                         socket->sk->sk_rcvbuf = 140 * 1024;
2851         }
2852
2853         if (server->tcp_nodelay)
2854                 tcp_sock_set_nodelay(socket->sk);
2855
2856         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2857                  socket->sk->sk_sndbuf,
2858                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2859
2860         rc = socket->ops->connect(socket, saddr, slen,
2861                                   server->noblockcnt ? O_NONBLOCK : 0);
2862         /*
2863          * When mounting SMB root file systems, we do not want to block in
2864          * connect. Otherwise bail out and then let cifs_reconnect() perform
2865          * reconnect failover - if possible.
2866          */
2867         if (server->noblockcnt && rc == -EINPROGRESS)
2868                 rc = 0;
2869         if (rc < 0) {
2870                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2871                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2872                 sock_release(socket);
2873                 server->ssocket = NULL;
2874                 return rc;
2875         }
2876         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2877         if (sport == htons(RFC1001_PORT))
2878                 rc = ip_rfc1001_connect(server);
2879
2880         return rc;
2881 }
2882
2883 static int
2884 ip_connect(struct TCP_Server_Info *server)
2885 {
2886         __be16 *sport;
2887         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2888         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2889
2890         if (server->dstaddr.ss_family == AF_INET6)
2891                 sport = &addr6->sin6_port;
2892         else
2893                 sport = &addr->sin_port;
2894
2895         if (*sport == 0) {
2896                 int rc;
2897
2898                 /* try with 445 port at first */
2899                 *sport = htons(CIFS_PORT);
2900
2901                 rc = generic_ip_connect(server);
2902                 if (rc >= 0)
2903                         return rc;
2904
2905                 /* if it failed, try with 139 port */
2906                 *sport = htons(RFC1001_PORT);
2907         }
2908
2909         return generic_ip_connect(server);
2910 }
2911
2912 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2913                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2914 {
2915         /*
2916          * If we are reconnecting then should we check to see if
2917          * any requested capabilities changed locally e.g. via
2918          * remount but we can not do much about it here
2919          * if they have (even if we could detect it by the following)
2920          * Perhaps we could add a backpointer to array of sb from tcon
2921          * or if we change to make all sb to same share the same
2922          * sb as NFS - then we only have one backpointer to sb.
2923          * What if we wanted to mount the server share twice once with
2924          * and once without posixacls or posix paths?
2925          */
2926         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2927
2928         if (ctx && ctx->no_linux_ext) {
2929                 tcon->fsUnixInfo.Capability = 0;
2930                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2931                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2932                 return;
2933         } else if (ctx)
2934                 tcon->unix_ext = 1; /* Unix Extensions supported */
2935
2936         if (!tcon->unix_ext) {
2937                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2938                 return;
2939         }
2940
2941         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2942                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2943                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2944                 /*
2945                  * check for reconnect case in which we do not
2946                  * want to change the mount behavior if we can avoid it
2947                  */
2948                 if (ctx == NULL) {
2949                         /*
2950                          * turn off POSIX ACL and PATHNAMES if not set
2951                          * originally at mount time
2952                          */
2953                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2954                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2955                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2956                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2957                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2958                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2959                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2960                                 cifs_dbg(VFS, "possible reconnect error\n");
2961                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2962                         }
2963                 }
2964
2965                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2966                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2967
2968                 cap &= CIFS_UNIX_CAP_MASK;
2969                 if (ctx && ctx->no_psx_acl)
2970                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2971                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2972                         cifs_dbg(FYI, "negotiated posix acl support\n");
2973                         if (cifs_sb)
2974                                 cifs_sb->mnt_cifs_flags |=
2975                                         CIFS_MOUNT_POSIXACL;
2976                 }
2977
2978                 if (ctx && ctx->posix_paths == 0)
2979                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2980                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2981                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2982                         if (cifs_sb)
2983                                 cifs_sb->mnt_cifs_flags |=
2984                                         CIFS_MOUNT_POSIX_PATHS;
2985                 }
2986
2987                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
2988 #ifdef CONFIG_CIFS_DEBUG2
2989                 if (cap & CIFS_UNIX_FCNTL_CAP)
2990                         cifs_dbg(FYI, "FCNTL cap\n");
2991                 if (cap & CIFS_UNIX_EXTATTR_CAP)
2992                         cifs_dbg(FYI, "EXTATTR cap\n");
2993                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2994                         cifs_dbg(FYI, "POSIX path cap\n");
2995                 if (cap & CIFS_UNIX_XATTR_CAP)
2996                         cifs_dbg(FYI, "XATTR cap\n");
2997                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
2998                         cifs_dbg(FYI, "POSIX ACL cap\n");
2999                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3000                         cifs_dbg(FYI, "very large read cap\n");
3001                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3002                         cifs_dbg(FYI, "very large write cap\n");
3003                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3004                         cifs_dbg(FYI, "transport encryption cap\n");
3005                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3006                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3007 #endif /* CIFS_DEBUG2 */
3008                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3009                         if (ctx == NULL)
3010                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3011                         else
3012                                 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");
3013
3014                 }
3015         }
3016 }
3017
3018 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3019 {
3020         struct smb3_fs_context *ctx = cifs_sb->ctx;
3021
3022         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3023
3024         spin_lock_init(&cifs_sb->tlink_tree_lock);
3025         cifs_sb->tlink_tree = RB_ROOT;
3026
3027         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3028                  ctx->file_mode, ctx->dir_mode);
3029
3030         /* this is needed for ASCII cp to Unicode converts */
3031         if (ctx->iocharset == NULL) {
3032                 /* load_nls_default cannot return null */
3033                 cifs_sb->local_nls = load_nls_default();
3034         } else {
3035                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3036                 if (cifs_sb->local_nls == NULL) {
3037                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3038                                  ctx->iocharset);
3039                         return -ELIBACC;
3040                 }
3041         }
3042         ctx->local_nls = cifs_sb->local_nls;
3043
3044         smb3_update_mnt_flags(cifs_sb);
3045
3046         if (ctx->direct_io)
3047                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3048         if (ctx->cache_ro) {
3049                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3050                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3051         } else if (ctx->cache_rw) {
3052                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3053                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3054                                             CIFS_MOUNT_RW_CACHE);
3055         }
3056
3057         if ((ctx->cifs_acl) && (ctx->dynperm))
3058                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3059
3060         if (ctx->prepath) {
3061                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3062                 if (cifs_sb->prepath == NULL)
3063                         return -ENOMEM;
3064                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3065         }
3066
3067         return 0;
3068 }
3069
3070 /* Release all succeed connections */
3071 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
3072 {
3073         int rc = 0;
3074
3075         if (mnt_ctx->tcon)
3076                 cifs_put_tcon(mnt_ctx->tcon);
3077         else if (mnt_ctx->ses)
3078                 cifs_put_smb_ses(mnt_ctx->ses);
3079         else if (mnt_ctx->server)
3080                 cifs_put_tcp_session(mnt_ctx->server, 0);
3081         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3082         free_xid(mnt_ctx->xid);
3083 }
3084
3085 /* Get connections for tcp, ses and tcon */
3086 static int mount_get_conns(struct mount_ctx *mnt_ctx)
3087 {
3088         int rc = 0;
3089         struct TCP_Server_Info *server = NULL;
3090         struct cifs_ses *ses = NULL;
3091         struct cifs_tcon *tcon = NULL;
3092         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3093         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3094         unsigned int xid;
3095
3096         xid = get_xid();
3097
3098         /* get a reference to a tcp session */
3099         server = cifs_get_tcp_session(ctx, NULL);
3100         if (IS_ERR(server)) {
3101                 rc = PTR_ERR(server);
3102                 server = NULL;
3103                 goto out;
3104         }
3105
3106         /* get a reference to a SMB session */
3107         ses = cifs_get_smb_ses(server, ctx);
3108         if (IS_ERR(ses)) {
3109                 rc = PTR_ERR(ses);
3110                 ses = NULL;
3111                 goto out;
3112         }
3113
3114         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3115                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3116                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3117                 rc = -EOPNOTSUPP;
3118                 goto out;
3119         }
3120
3121         /* search for existing tcon to this server share */
3122         tcon = cifs_get_tcon(ses, ctx);
3123         if (IS_ERR(tcon)) {
3124                 rc = PTR_ERR(tcon);
3125                 tcon = NULL;
3126                 goto out;
3127         }
3128
3129         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3130         if (tcon->posix_extensions)
3131                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3132
3133         /* tell server which Unix caps we support */
3134         if (cap_unix(tcon->ses)) {
3135                 /*
3136                  * reset of caps checks mount to see if unix extensions disabled
3137                  * for just this mount.
3138                  */
3139                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3140                 spin_lock(&cifs_tcp_ses_lock);
3141                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3142                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3143                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3144                         spin_unlock(&cifs_tcp_ses_lock);
3145                         rc = -EACCES;
3146                         goto out;
3147                 }
3148                 spin_unlock(&cifs_tcp_ses_lock);
3149         } else
3150                 tcon->unix_ext = 0; /* server does not support them */
3151
3152         /* do not care if a following call succeed - informational */
3153         if (!tcon->pipe && server->ops->qfs_tcon) {
3154                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3155                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3156                         if (tcon->fsDevInfo.DeviceCharacteristics &
3157                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3158                                 cifs_dbg(VFS, "mounted to read only share\n");
3159                         else if ((cifs_sb->mnt_cifs_flags &
3160                                   CIFS_MOUNT_RW_CACHE) == 0)
3161                                 cifs_dbg(VFS, "read only mount of RW share\n");
3162                         /* no need to log a RW mount of a typical RW share */
3163                 }
3164         }
3165
3166         /*
3167          * Clamp the rsize/wsize mount arguments if they are too big for the server
3168          * and set the rsize/wsize to the negotiated values if not passed in by
3169          * the user on mount
3170          */
3171         if ((cifs_sb->ctx->wsize == 0) ||
3172             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3173                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3174         if ((cifs_sb->ctx->rsize == 0) ||
3175             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3176                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3177
3178         /*
3179          * The cookie is initialized from volume info returned above.
3180          * Inside cifs_fscache_get_super_cookie it checks
3181          * that we do not get super cookie twice.
3182          */
3183         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3184                 cifs_fscache_get_super_cookie(tcon);
3185
3186 out:
3187         mnt_ctx->server = server;
3188         mnt_ctx->ses = ses;
3189         mnt_ctx->tcon = tcon;
3190         mnt_ctx->xid = xid;
3191
3192         return rc;
3193 }
3194
3195 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3196                              struct cifs_tcon *tcon)
3197 {
3198         struct tcon_link *tlink;
3199
3200         /* hang the tcon off of the superblock */
3201         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3202         if (tlink == NULL)
3203                 return -ENOMEM;
3204
3205         tlink->tl_uid = ses->linux_uid;
3206         tlink->tl_tcon = tcon;
3207         tlink->tl_time = jiffies;
3208         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3209         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3210
3211         cifs_sb->master_tlink = tlink;
3212         spin_lock(&cifs_sb->tlink_tree_lock);
3213         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3214         spin_unlock(&cifs_sb->tlink_tree_lock);
3215
3216         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3217                                 TLINK_IDLE_EXPIRE);
3218         return 0;
3219 }
3220
3221 #ifdef CONFIG_CIFS_DFS_UPCALL
3222 /* Get unique dfs connections */
3223 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3224 {
3225         int rc;
3226
3227         mnt_ctx->fs_ctx->nosharesock = true;
3228         rc = mount_get_conns(mnt_ctx);
3229         if (mnt_ctx->server) {
3230                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3231                 spin_lock(&cifs_tcp_ses_lock);
3232                 mnt_ctx->server->is_dfs_conn = true;
3233                 spin_unlock(&cifs_tcp_ses_lock);
3234         }
3235         return rc;
3236 }
3237
3238 /*
3239  * cifs_build_path_to_root returns full path to root when we do not have an
3240  * existing connection (tcon)
3241  */
3242 static char *
3243 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3244                        const struct cifs_sb_info *cifs_sb, bool useppath)
3245 {
3246         char *full_path, *pos;
3247         unsigned int pplen = useppath && ctx->prepath ?
3248                 strlen(ctx->prepath) + 1 : 0;
3249         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3250
3251         if (unc_len > MAX_TREE_SIZE)
3252                 return ERR_PTR(-EINVAL);
3253
3254         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3255         if (full_path == NULL)
3256                 return ERR_PTR(-ENOMEM);
3257
3258         memcpy(full_path, ctx->UNC, unc_len);
3259         pos = full_path + unc_len;
3260
3261         if (pplen) {
3262                 *pos = CIFS_DIR_SEP(cifs_sb);
3263                 memcpy(pos + 1, ctx->prepath, pplen);
3264                 pos += pplen;
3265         }
3266
3267         *pos = '\0'; /* add trailing null */
3268         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3269         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3270         return full_path;
3271 }
3272
3273 /*
3274  * expand_dfs_referral - Update cifs_sb from dfs referral path
3275  *
3276  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3277  * submount.  Otherwise it will be left untouched.
3278  */
3279 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3280                                struct dfs_info3_param *referral)
3281 {
3282         int rc;
3283         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3284         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3285         char *fake_devname = NULL, *mdata = NULL;
3286
3287         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3288                                            &fake_devname);
3289         if (IS_ERR(mdata)) {
3290                 rc = PTR_ERR(mdata);
3291                 mdata = NULL;
3292         } else {
3293                 /*
3294                  * We can not clear out the whole structure since we no longer have an explicit
3295                  * function to parse a mount-string. Instead we need to clear out the individual
3296                  * fields that are no longer valid.
3297                  */
3298                 kfree(ctx->prepath);
3299                 ctx->prepath = NULL;
3300                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3301         }
3302         kfree(fake_devname);
3303         kfree(cifs_sb->ctx->mount_options);
3304         cifs_sb->ctx->mount_options = mdata;
3305
3306         return rc;
3307 }
3308 #endif
3309
3310 /* TODO: all callers to this are broken. We are not parsing mount_options here
3311  * we should pass a clone of the original context?
3312  */
3313 int
3314 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3315 {
3316         int rc;
3317
3318         if (devname) {
3319                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3320                 rc = smb3_parse_devname(devname, ctx);
3321                 if (rc) {
3322                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3323                         return rc;
3324                 }
3325         }
3326
3327         if (mntopts) {
3328                 char *ip;
3329
3330                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3331                 if (rc) {
3332                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3333                         return rc;
3334                 }
3335
3336                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3337                 kfree(ip);
3338                 if (!rc) {
3339                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3340                         return -EINVAL;
3341                 }
3342         }
3343
3344         if (ctx->nullauth) {
3345                 cifs_dbg(FYI, "Anonymous login\n");
3346                 kfree(ctx->username);
3347                 ctx->username = NULL;
3348         } else if (ctx->username) {
3349                 /* BB fixme parse for domain name here */
3350                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3351         } else {
3352                 cifs_dbg(VFS, "No username specified\n");
3353         /* In userspace mount helper we can get user name from alternate
3354            locations such as env variables and files on disk */
3355                 return -EINVAL;
3356         }
3357
3358         return 0;
3359 }
3360
3361 static int
3362 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3363                                         unsigned int xid,
3364                                         struct cifs_tcon *tcon,
3365                                         struct cifs_sb_info *cifs_sb,
3366                                         char *full_path,
3367                                         int added_treename)
3368 {
3369         int rc;
3370         char *s;
3371         char sep, tmp;
3372         int skip = added_treename ? 1 : 0;
3373
3374         sep = CIFS_DIR_SEP(cifs_sb);
3375         s = full_path;
3376
3377         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3378         while (rc == 0) {
3379                 /* skip separators */
3380                 while (*s == sep)
3381                         s++;
3382                 if (!*s)
3383                         break;
3384                 /* next separator */
3385                 while (*s && *s != sep)
3386                         s++;
3387                 /*
3388                  * if the treename is added, we then have to skip the first
3389                  * part within the separators
3390                  */
3391                 if (skip) {
3392                         skip = 0;
3393                         continue;
3394                 }
3395                 /*
3396                  * temporarily null-terminate the path at the end of
3397                  * the current component
3398                  */
3399                 tmp = *s;
3400                 *s = 0;
3401                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3402                                                      full_path);
3403                 *s = tmp;
3404         }
3405         return rc;
3406 }
3407
3408 /*
3409  * Check if path is remote (i.e. a DFS share).
3410  *
3411  * Return -EREMOTE if it is, otherwise 0 or -errno.
3412  */
3413 static int is_path_remote(struct mount_ctx *mnt_ctx)
3414 {
3415         int rc;
3416         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3417         struct TCP_Server_Info *server = mnt_ctx->server;
3418         unsigned int xid = mnt_ctx->xid;
3419         struct cifs_tcon *tcon = mnt_ctx->tcon;
3420         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3421         char *full_path;
3422 #ifdef CONFIG_CIFS_DFS_UPCALL
3423         bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
3424 #endif
3425
3426         if (!server->ops->is_path_accessible)
3427                 return -EOPNOTSUPP;
3428
3429         /*
3430          * cifs_build_path_to_root works only when we have a valid tcon
3431          */
3432         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3433                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3434         if (full_path == NULL)
3435                 return -ENOMEM;
3436
3437         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3438
3439         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3440                                              full_path);
3441 #ifdef CONFIG_CIFS_DFS_UPCALL
3442         if (nodfs) {
3443                 if (rc == -EREMOTE)
3444                         rc = -EOPNOTSUPP;
3445                 goto out;
3446         }
3447
3448         /* path *might* exist with non-ASCII characters in DFS root
3449          * try again with full path (only if nodfs is not set) */
3450         if (rc == -ENOENT && is_tcon_dfs(tcon))
3451                 rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
3452                                                         full_path);
3453 #endif
3454         if (rc != 0 && rc != -EREMOTE)
3455                 goto out;
3456
3457         if (rc != -EREMOTE) {
3458                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3459                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3460                 if (rc != 0) {
3461                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3462                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3463                         rc = 0;
3464                 }
3465         }
3466
3467 out:
3468         kfree(full_path);
3469         return rc;
3470 }
3471
3472 #ifdef CONFIG_CIFS_DFS_UPCALL
3473 static void set_root_ses(struct mount_ctx *mnt_ctx)
3474 {
3475         if (mnt_ctx->ses) {
3476                 spin_lock(&cifs_tcp_ses_lock);
3477                 mnt_ctx->ses->ses_count++;
3478                 spin_unlock(&cifs_tcp_ses_lock);
3479                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3480         }
3481         mnt_ctx->root_ses = mnt_ctx->ses;
3482 }
3483
3484 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3485 {
3486         int rc;
3487         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3488         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3489
3490         *isdfs = true;
3491
3492         rc = mount_get_conns(mnt_ctx);
3493         /*
3494          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3495          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3496          *
3497          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3498          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3499          */
3500         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3501             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3502                            ctx->UNC + 1, NULL, root_tl)) {
3503                 if (rc)
3504                         return rc;
3505                 /* Check if it is fully accessible and then mount it */
3506                 rc = is_path_remote(mnt_ctx);
3507                 if (!rc)
3508                         *isdfs = false;
3509                 else if (rc != -EREMOTE)
3510                         return rc;
3511         }
3512         return 0;
3513 }
3514
3515 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3516                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3517 {
3518         int rc;
3519         struct dfs_info3_param ref = {};
3520         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3521         char *oldmnt = cifs_sb->ctx->mount_options;
3522
3523         cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
3524                  dfs_cache_get_tgt_name(tit));
3525
3526         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3527         if (rc)
3528                 goto out;
3529
3530         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3531         if (rc)
3532                 goto out;
3533
3534         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3535         if (oldmnt != cifs_sb->ctx->mount_options) {
3536                 mount_put_conns(mnt_ctx);
3537                 rc = mount_get_dfs_conns(mnt_ctx);
3538         }
3539         if (!rc) {
3540                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3541                         set_root_ses(mnt_ctx);
3542                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3543                                               cifs_remap(cifs_sb), ref_path, tit);
3544         }
3545
3546 out:
3547         free_dfs_info_param(&ref);
3548         return rc;
3549 }
3550
3551 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3552 {
3553         int rc;
3554         char *full_path;
3555         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3556         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3557         struct dfs_cache_tgt_iterator *tit;
3558
3559         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3560          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3561          * now on.
3562          */
3563         mount_put_conns(mnt_ctx);
3564         mount_get_dfs_conns(mnt_ctx);
3565         set_root_ses(mnt_ctx);
3566
3567         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3568         if (IS_ERR(full_path))
3569                 return PTR_ERR(full_path);
3570
3571         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3572                                                             cifs_remap(cifs_sb));
3573         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3574                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3575                 mnt_ctx->origin_fullpath = NULL;
3576                 goto out;
3577         }
3578
3579         /* Try all dfs root targets */
3580         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3581              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3582                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3583                 if (!rc) {
3584                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3585                         if (!mnt_ctx->leaf_fullpath)
3586                                 rc = -ENOMEM;
3587                         break;
3588                 }
3589         }
3590
3591 out:
3592         kfree(full_path);
3593         return rc;
3594 }
3595
3596 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3597 {
3598         int rc;
3599         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3600         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3601         char *full_path;
3602         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3603         struct dfs_cache_tgt_iterator *tit;
3604
3605         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3606         if (IS_ERR(full_path))
3607                 return PTR_ERR(full_path);
3608
3609         kfree(mnt_ctx->leaf_fullpath);
3610         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3611                                                           cifs_remap(cifs_sb));
3612         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3613                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3614                 mnt_ctx->leaf_fullpath = NULL;
3615                 goto out;
3616         }
3617
3618         /* Get referral from dfs link */
3619         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3620                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3621         if (rc)
3622                 goto out;
3623
3624         /* Try all dfs link targets.  If an I/O fails from currently connected DFS target with an
3625          * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
3626          * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
3627          * STATUS_PATH_NOT_COVERED."
3628          */
3629         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3630              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3631                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3632                 if (!rc) {
3633                         rc = is_path_remote(mnt_ctx);
3634                         if (!rc || rc == -EREMOTE)
3635                                 break;
3636                 }
3637         }
3638
3639 out:
3640         kfree(full_path);
3641         dfs_cache_free_tgts(&tl);
3642         return rc;
3643 }
3644
3645 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3646 {
3647         int rc;
3648         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3649         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3650         char *full_path;
3651         int num_links = 0;
3652
3653         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3654         if (IS_ERR(full_path))
3655                 return PTR_ERR(full_path);
3656
3657         kfree(mnt_ctx->origin_fullpath);
3658         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3659                                                             cifs_remap(cifs_sb));
3660         kfree(full_path);
3661
3662         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3663                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3664                 mnt_ctx->origin_fullpath = NULL;
3665                 return rc;
3666         }
3667
3668         do {
3669                 rc = __follow_dfs_link(mnt_ctx);
3670                 if (!rc || rc != -EREMOTE)
3671                         break;
3672         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3673
3674         return rc;
3675 }
3676
3677 /* Set up DFS referral paths for failover */
3678 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3679 {
3680         struct TCP_Server_Info *server = mnt_ctx->server;
3681
3682         mutex_lock(&server->refpath_lock);
3683         server->origin_fullpath = mnt_ctx->origin_fullpath;
3684         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3685         server->current_fullpath = mnt_ctx->leaf_fullpath;
3686         mutex_unlock(&server->refpath_lock);
3687         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3688 }
3689
3690 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3691 {
3692         int rc;
3693         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3694         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3695         bool isdfs;
3696
3697         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3698         if (rc)
3699                 goto error;
3700         if (!isdfs)
3701                 goto out;
3702
3703         /* proceed as DFS mount */
3704         uuid_gen(&mnt_ctx.mount_id);
3705         rc = connect_dfs_root(&mnt_ctx, &tl);
3706         dfs_cache_free_tgts(&tl);
3707
3708         if (rc)
3709                 goto error;
3710
3711         rc = is_path_remote(&mnt_ctx);
3712         if (rc)
3713                 rc = follow_dfs_link(&mnt_ctx);
3714         if (rc)
3715                 goto error;
3716
3717         setup_server_referral_paths(&mnt_ctx);
3718         /*
3719          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3720          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3721          */
3722         cifs_autodisable_serverino(cifs_sb);
3723         /*
3724          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3725          * that have different prefix paths.
3726          */
3727         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3728         kfree(cifs_sb->prepath);
3729         cifs_sb->prepath = ctx->prepath;
3730         ctx->prepath = NULL;
3731         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3732
3733 out:
3734         free_xid(mnt_ctx.xid);
3735         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3736         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3737
3738 error:
3739         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3740         kfree(mnt_ctx.origin_fullpath);
3741         kfree(mnt_ctx.leaf_fullpath);
3742         mount_put_conns(&mnt_ctx);
3743         return rc;
3744 }
3745 #else
3746 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3747 {
3748         int rc = 0;
3749         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3750
3751         rc = mount_get_conns(&mnt_ctx);
3752         if (rc)
3753                 goto error;
3754
3755         if (mnt_ctx.tcon) {
3756                 rc = is_path_remote(&mnt_ctx);
3757                 if (rc == -EREMOTE)
3758                         rc = -EOPNOTSUPP;
3759                 if (rc)
3760                         goto error;
3761         }
3762
3763         free_xid(mnt_ctx.xid);
3764         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3765
3766 error:
3767         mount_put_conns(&mnt_ctx);
3768         return rc;
3769 }
3770 #endif
3771
3772 /*
3773  * Issue a TREE_CONNECT request.
3774  */
3775 int
3776 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3777          const char *tree, struct cifs_tcon *tcon,
3778          const struct nls_table *nls_codepage)
3779 {
3780         struct smb_hdr *smb_buffer;
3781         struct smb_hdr *smb_buffer_response;
3782         TCONX_REQ *pSMB;
3783         TCONX_RSP *pSMBr;
3784         unsigned char *bcc_ptr;
3785         int rc = 0;
3786         int length;
3787         __u16 bytes_left, count;
3788
3789         if (ses == NULL)
3790                 return -EIO;
3791
3792         smb_buffer = cifs_buf_get();
3793         if (smb_buffer == NULL)
3794                 return -ENOMEM;
3795
3796         smb_buffer_response = smb_buffer;
3797
3798         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3799                         NULL /*no tid */ , 4 /*wct */ );
3800
3801         smb_buffer->Mid = get_next_mid(ses->server);
3802         smb_buffer->Uid = ses->Suid;
3803         pSMB = (TCONX_REQ *) smb_buffer;
3804         pSMBr = (TCONX_RSP *) smb_buffer_response;
3805
3806         pSMB->AndXCommand = 0xFF;
3807         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3808         bcc_ptr = &pSMB->Password[0];
3809         if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
3810                 pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3811                 *bcc_ptr = 0; /* password is null byte */
3812                 bcc_ptr++;              /* skip password */
3813                 /* already aligned so no need to do it below */
3814         }
3815
3816         if (ses->server->sign)
3817                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3818
3819         if (ses->capabilities & CAP_STATUS32) {
3820                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3821         }
3822         if (ses->capabilities & CAP_DFS) {
3823                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3824         }
3825         if (ses->capabilities & CAP_UNICODE) {
3826                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3827                 length =
3828                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3829                         6 /* max utf8 char length in bytes */ *
3830                         (/* server len*/ + 256 /* share len */), nls_codepage);
3831                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3832                 bcc_ptr += 2;   /* skip trailing null */
3833         } else {                /* ASCII */
3834                 strcpy(bcc_ptr, tree);
3835                 bcc_ptr += strlen(tree) + 1;
3836         }
3837         strcpy(bcc_ptr, "?????");
3838         bcc_ptr += strlen("?????");
3839         bcc_ptr += 1;
3840         count = bcc_ptr - &pSMB->Password[0];
3841         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3842         pSMB->ByteCount = cpu_to_le16(count);
3843
3844         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3845                          0);
3846
3847         /* above now done in SendReceive */
3848         if (rc == 0) {
3849                 bool is_unicode;
3850
3851                 tcon->tid = smb_buffer_response->Tid;
3852                 bcc_ptr = pByteArea(smb_buffer_response);
3853                 bytes_left = get_bcc(smb_buffer_response);
3854                 length = strnlen(bcc_ptr, bytes_left - 2);
3855                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3856                         is_unicode = true;
3857                 else
3858                         is_unicode = false;
3859
3860
3861                 /* skip service field (NB: this field is always ASCII) */
3862                 if (length == 3) {
3863                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3864                             (bcc_ptr[2] == 'C')) {
3865                                 cifs_dbg(FYI, "IPC connection\n");
3866                                 tcon->ipc = true;
3867                                 tcon->pipe = true;
3868                         }
3869                 } else if (length == 2) {
3870                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3871                                 /* the most common case */
3872                                 cifs_dbg(FYI, "disk share connection\n");
3873                         }
3874                 }
3875                 bcc_ptr += length + 1;
3876                 bytes_left -= (length + 1);
3877                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3878
3879                 /* mostly informational -- no need to fail on error here */
3880                 kfree(tcon->nativeFileSystem);
3881                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3882                                                       bytes_left, is_unicode,
3883                                                       nls_codepage);
3884
3885                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3886
3887                 if ((smb_buffer_response->WordCount == 3) ||
3888                          (smb_buffer_response->WordCount == 7))
3889                         /* field is in same location */
3890                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3891                 else
3892                         tcon->Flags = 0;
3893                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3894         }
3895
3896         cifs_buf_release(smb_buffer);
3897         return rc;
3898 }
3899
3900 static void delayed_free(struct rcu_head *p)
3901 {
3902         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3903
3904         unload_nls(cifs_sb->local_nls);
3905         smb3_cleanup_fs_context(cifs_sb->ctx);
3906         kfree(cifs_sb);
3907 }
3908
3909 void
3910 cifs_umount(struct cifs_sb_info *cifs_sb)
3911 {
3912         struct rb_root *root = &cifs_sb->tlink_tree;
3913         struct rb_node *node;
3914         struct tcon_link *tlink;
3915
3916         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3917
3918         spin_lock(&cifs_sb->tlink_tree_lock);
3919         while ((node = rb_first(root))) {
3920                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3921                 cifs_get_tlink(tlink);
3922                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3923                 rb_erase(node, root);
3924
3925                 spin_unlock(&cifs_sb->tlink_tree_lock);
3926                 cifs_put_tlink(tlink);
3927                 spin_lock(&cifs_sb->tlink_tree_lock);
3928         }
3929         spin_unlock(&cifs_sb->tlink_tree_lock);
3930
3931         kfree(cifs_sb->prepath);
3932 #ifdef CONFIG_CIFS_DFS_UPCALL
3933         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3934 #endif
3935         call_rcu(&cifs_sb->rcu, delayed_free);
3936 }
3937
3938 int
3939 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3940                         struct TCP_Server_Info *server)
3941 {
3942         int rc = 0;
3943
3944         if (!server->ops->need_neg || !server->ops->negotiate)
3945                 return -ENOSYS;
3946
3947         /* only send once per connect */
3948         spin_lock(&cifs_tcp_ses_lock);
3949         if (!server->ops->need_neg(server) ||
3950             server->tcpStatus != CifsNeedNegotiate) {
3951                 spin_unlock(&cifs_tcp_ses_lock);
3952                 return 0;
3953         }
3954         server->tcpStatus = CifsInNegotiate;
3955         spin_unlock(&cifs_tcp_ses_lock);
3956
3957         rc = server->ops->negotiate(xid, ses, server);
3958         if (rc == 0) {
3959                 spin_lock(&cifs_tcp_ses_lock);
3960                 if (server->tcpStatus == CifsInNegotiate)
3961                         server->tcpStatus = CifsGood;
3962                 else
3963                         rc = -EHOSTDOWN;
3964                 spin_unlock(&cifs_tcp_ses_lock);
3965         } else {
3966                 spin_lock(&cifs_tcp_ses_lock);
3967                 if (server->tcpStatus == CifsInNegotiate)
3968                         server->tcpStatus = CifsNeedNegotiate;
3969                 spin_unlock(&cifs_tcp_ses_lock);
3970         }
3971
3972         return rc;
3973 }
3974
3975 int
3976 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3977                    struct TCP_Server_Info *server,
3978                    struct nls_table *nls_info)
3979 {
3980         int rc = -ENOSYS;
3981         bool is_binding = false;
3982
3983
3984         spin_lock(&cifs_tcp_ses_lock);
3985         if (ses->ses_status != SES_GOOD &&
3986             ses->ses_status != SES_NEW &&
3987             ses->ses_status != SES_NEED_RECON) {
3988                 spin_unlock(&cifs_tcp_ses_lock);
3989                 return 0;
3990         }
3991
3992         /* only send once per connect */
3993         spin_lock(&ses->chan_lock);
3994         if (CIFS_ALL_CHANS_GOOD(ses) ||
3995             cifs_chan_in_reconnect(ses, server)) {
3996                 spin_unlock(&ses->chan_lock);
3997                 spin_unlock(&cifs_tcp_ses_lock);
3998                 return 0;
3999         }
4000         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
4001         cifs_chan_set_in_reconnect(ses, server);
4002         spin_unlock(&ses->chan_lock);
4003
4004         if (!is_binding)
4005                 ses->ses_status = SES_IN_SETUP;
4006         spin_unlock(&cifs_tcp_ses_lock);
4007
4008         if (!is_binding) {
4009                 ses->capabilities = server->capabilities;
4010                 if (!linuxExtEnabled)
4011                         ses->capabilities &= (~server->vals->cap_unix);
4012
4013                 if (ses->auth_key.response) {
4014                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
4015                                  ses->auth_key.response);
4016                         kfree(ses->auth_key.response);
4017                         ses->auth_key.response = NULL;
4018                         ses->auth_key.len = 0;
4019                 }
4020         }
4021
4022         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
4023                  server->sec_mode, server->capabilities, server->timeAdj);
4024
4025         if (server->ops->sess_setup)
4026                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
4027
4028         if (rc) {
4029                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4030                 spin_lock(&cifs_tcp_ses_lock);
4031                 if (ses->ses_status == SES_IN_SETUP)
4032                         ses->ses_status = SES_NEED_RECON;
4033                 spin_lock(&ses->chan_lock);
4034                 cifs_chan_clear_in_reconnect(ses, server);
4035                 spin_unlock(&ses->chan_lock);
4036                 spin_unlock(&cifs_tcp_ses_lock);
4037         } else {
4038                 spin_lock(&cifs_tcp_ses_lock);
4039                 if (ses->ses_status == SES_IN_SETUP)
4040                         ses->ses_status = SES_GOOD;
4041                 spin_lock(&ses->chan_lock);
4042                 cifs_chan_clear_in_reconnect(ses, server);
4043                 cifs_chan_clear_need_reconnect(ses, server);
4044                 spin_unlock(&ses->chan_lock);
4045                 spin_unlock(&cifs_tcp_ses_lock);
4046         }
4047
4048         return rc;
4049 }
4050
4051 static int
4052 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4053 {
4054         ctx->sectype = ses->sectype;
4055
4056         /* krb5 is special, since we don't need username or pw */
4057         if (ctx->sectype == Kerberos)
4058                 return 0;
4059
4060         return cifs_set_cifscreds(ctx, ses);
4061 }
4062
4063 static struct cifs_tcon *
4064 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4065 {
4066         int rc;
4067         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4068         struct cifs_ses *ses;
4069         struct cifs_tcon *tcon = NULL;
4070         struct smb3_fs_context *ctx;
4071
4072         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4073         if (ctx == NULL)
4074                 return ERR_PTR(-ENOMEM);
4075
4076         ctx->local_nls = cifs_sb->local_nls;
4077         ctx->linux_uid = fsuid;
4078         ctx->cred_uid = fsuid;
4079         ctx->UNC = master_tcon->treeName;
4080         ctx->retry = master_tcon->retry;
4081         ctx->nocase = master_tcon->nocase;
4082         ctx->nohandlecache = master_tcon->nohandlecache;
4083         ctx->local_lease = master_tcon->local_lease;
4084         ctx->no_lease = master_tcon->no_lease;
4085         ctx->resilient = master_tcon->use_resilient;
4086         ctx->persistent = master_tcon->use_persistent;
4087         ctx->handle_timeout = master_tcon->handle_timeout;
4088         ctx->no_linux_ext = !master_tcon->unix_ext;
4089         ctx->linux_ext = master_tcon->posix_extensions;
4090         ctx->sectype = master_tcon->ses->sectype;
4091         ctx->sign = master_tcon->ses->sign;
4092         ctx->seal = master_tcon->seal;
4093         ctx->witness = master_tcon->use_witness;
4094
4095         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4096         if (rc) {
4097                 tcon = ERR_PTR(rc);
4098                 goto out;
4099         }
4100
4101         /* get a reference for the same TCP session */
4102         spin_lock(&cifs_tcp_ses_lock);
4103         ++master_tcon->ses->server->srv_count;
4104         spin_unlock(&cifs_tcp_ses_lock);
4105
4106         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4107         if (IS_ERR(ses)) {
4108                 tcon = (struct cifs_tcon *)ses;
4109                 cifs_put_tcp_session(master_tcon->ses->server, 0);
4110                 goto out;
4111         }
4112
4113         tcon = cifs_get_tcon(ses, ctx);
4114         if (IS_ERR(tcon)) {
4115                 cifs_put_smb_ses(ses);
4116                 goto out;
4117         }
4118
4119         if (cap_unix(ses))
4120                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4121
4122 out:
4123         kfree(ctx->username);
4124         kfree_sensitive(ctx->password);
4125         kfree(ctx);
4126
4127         return tcon;
4128 }
4129
4130 struct cifs_tcon *
4131 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4132 {
4133         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4134 }
4135
4136 /* find and return a tlink with given uid */
4137 static struct tcon_link *
4138 tlink_rb_search(struct rb_root *root, kuid_t uid)
4139 {
4140         struct rb_node *node = root->rb_node;
4141         struct tcon_link *tlink;
4142
4143         while (node) {
4144                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4145
4146                 if (uid_gt(tlink->tl_uid, uid))
4147                         node = node->rb_left;
4148                 else if (uid_lt(tlink->tl_uid, uid))
4149                         node = node->rb_right;
4150                 else
4151                         return tlink;
4152         }
4153         return NULL;
4154 }
4155
4156 /* insert a tcon_link into the tree */
4157 static void
4158 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4159 {
4160         struct rb_node **new = &(root->rb_node), *parent = NULL;
4161         struct tcon_link *tlink;
4162
4163         while (*new) {
4164                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4165                 parent = *new;
4166
4167                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4168                         new = &((*new)->rb_left);
4169                 else
4170                         new = &((*new)->rb_right);
4171         }
4172
4173         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4174         rb_insert_color(&new_tlink->tl_rbnode, root);
4175 }
4176
4177 /*
4178  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4179  * current task.
4180  *
4181  * If the superblock doesn't refer to a multiuser mount, then just return
4182  * the master tcon for the mount.
4183  *
4184  * First, search the rbtree for an existing tcon for this fsuid. If one
4185  * exists, then check to see if it's pending construction. If it is then wait
4186  * for construction to complete. Once it's no longer pending, check to see if
4187  * it failed and either return an error or retry construction, depending on
4188  * the timeout.
4189  *
4190  * If one doesn't exist then insert a new tcon_link struct into the tree and
4191  * try to construct a new one.
4192  */
4193 struct tcon_link *
4194 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4195 {
4196         int ret;
4197         kuid_t fsuid = current_fsuid();
4198         struct tcon_link *tlink, *newtlink;
4199
4200         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4201                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4202
4203         spin_lock(&cifs_sb->tlink_tree_lock);
4204         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4205         if (tlink)
4206                 cifs_get_tlink(tlink);
4207         spin_unlock(&cifs_sb->tlink_tree_lock);
4208
4209         if (tlink == NULL) {
4210                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4211                 if (newtlink == NULL)
4212                         return ERR_PTR(-ENOMEM);
4213                 newtlink->tl_uid = fsuid;
4214                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4215                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4216                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4217                 cifs_get_tlink(newtlink);
4218
4219                 spin_lock(&cifs_sb->tlink_tree_lock);
4220                 /* was one inserted after previous search? */
4221                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4222                 if (tlink) {
4223                         cifs_get_tlink(tlink);
4224                         spin_unlock(&cifs_sb->tlink_tree_lock);
4225                         kfree(newtlink);
4226                         goto wait_for_construction;
4227                 }
4228                 tlink = newtlink;
4229                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4230                 spin_unlock(&cifs_sb->tlink_tree_lock);
4231         } else {
4232 wait_for_construction:
4233                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4234                                   TASK_INTERRUPTIBLE);
4235                 if (ret) {
4236                         cifs_put_tlink(tlink);
4237                         return ERR_PTR(-ERESTARTSYS);
4238                 }
4239
4240                 /* if it's good, return it */
4241                 if (!IS_ERR(tlink->tl_tcon))
4242                         return tlink;
4243
4244                 /* return error if we tried this already recently */
4245                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4246                         cifs_put_tlink(tlink);
4247                         return ERR_PTR(-EACCES);
4248                 }
4249
4250                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4251                         goto wait_for_construction;
4252         }
4253
4254         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4255         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4256         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4257
4258         if (IS_ERR(tlink->tl_tcon)) {
4259                 cifs_put_tlink(tlink);
4260                 return ERR_PTR(-EACCES);
4261         }
4262
4263         return tlink;
4264 }
4265
4266 /*
4267  * periodic workqueue job that scans tcon_tree for a superblock and closes
4268  * out tcons.
4269  */
4270 static void
4271 cifs_prune_tlinks(struct work_struct *work)
4272 {
4273         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4274                                                     prune_tlinks.work);
4275         struct rb_root *root = &cifs_sb->tlink_tree;
4276         struct rb_node *node;
4277         struct rb_node *tmp;
4278         struct tcon_link *tlink;
4279
4280         /*
4281          * Because we drop the spinlock in the loop in order to put the tlink
4282          * it's not guarded against removal of links from the tree. The only
4283          * places that remove entries from the tree are this function and
4284          * umounts. Because this function is non-reentrant and is canceled
4285          * before umount can proceed, this is safe.
4286          */
4287         spin_lock(&cifs_sb->tlink_tree_lock);
4288         node = rb_first(root);
4289         while (node != NULL) {
4290                 tmp = node;
4291                 node = rb_next(tmp);
4292                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4293
4294                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4295                     atomic_read(&tlink->tl_count) != 0 ||
4296                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4297                         continue;
4298
4299                 cifs_get_tlink(tlink);
4300                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4301                 rb_erase(tmp, root);
4302
4303                 spin_unlock(&cifs_sb->tlink_tree_lock);
4304                 cifs_put_tlink(tlink);
4305                 spin_lock(&cifs_sb->tlink_tree_lock);
4306         }
4307         spin_unlock(&cifs_sb->tlink_tree_lock);
4308
4309         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4310                                 TLINK_IDLE_EXPIRE);
4311 }
4312
4313 #ifdef CONFIG_CIFS_DFS_UPCALL
4314 /* Update dfs referral path of superblock */
4315 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4316                                   const char *target)
4317 {
4318         int rc = 0;
4319         size_t len = strlen(target);
4320         char *refpath, *npath;
4321
4322         if (unlikely(len < 2 || *target != '\\'))
4323                 return -EINVAL;
4324
4325         if (target[1] == '\\') {
4326                 len += 1;
4327                 refpath = kmalloc(len, GFP_KERNEL);
4328                 if (!refpath)
4329                         return -ENOMEM;
4330
4331                 scnprintf(refpath, len, "%s", target);
4332         } else {
4333                 len += sizeof("\\");
4334                 refpath = kmalloc(len, GFP_KERNEL);
4335                 if (!refpath)
4336                         return -ENOMEM;
4337
4338                 scnprintf(refpath, len, "\\%s", target);
4339         }
4340
4341         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4342         kfree(refpath);
4343
4344         if (IS_ERR(npath)) {
4345                 rc = PTR_ERR(npath);
4346         } else {
4347                 mutex_lock(&server->refpath_lock);
4348                 kfree(server->leaf_fullpath);
4349                 server->leaf_fullpath = npath;
4350                 mutex_unlock(&server->refpath_lock);
4351                 server->current_fullpath = server->leaf_fullpath;
4352         }
4353         return rc;
4354 }
4355
4356 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4357                                        size_t tcp_host_len, char *share, bool *target_match)
4358 {
4359         int rc = 0;
4360         const char *dfs_host;
4361         size_t dfs_host_len;
4362
4363         *target_match = true;
4364         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4365
4366         /* Check if hostnames or addresses match */
4367         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4368                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4369                          dfs_host, (int)tcp_host_len, tcp_host);
4370                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4371                 if (rc)
4372                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4373         }
4374         return rc;
4375 }
4376
4377 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4378                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4379                                      struct dfs_cache_tgt_list *tl)
4380 {
4381         int rc;
4382         struct TCP_Server_Info *server = tcon->ses->server;
4383         const struct smb_version_operations *ops = server->ops;
4384         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4385         char *share = NULL, *prefix = NULL;
4386         const char *tcp_host;
4387         size_t tcp_host_len;
4388         struct dfs_cache_tgt_iterator *tit;
4389         bool target_match;
4390
4391         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4392
4393         tit = dfs_cache_get_tgt_iterator(tl);
4394         if (!tit) {
4395                 rc = -ENOENT;
4396                 goto out;
4397         }
4398
4399         /* Try to tree connect to all dfs targets */
4400         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4401                 const char *target = dfs_cache_get_tgt_name(tit);
4402                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4403
4404                 kfree(share);
4405                 kfree(prefix);
4406                 share = prefix = NULL;
4407
4408                 /* Check if share matches with tcp ses */
4409                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4410                 if (rc) {
4411                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4412                         break;
4413                 }
4414
4415                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4416                                                  &target_match);
4417                 if (rc)
4418                         break;
4419                 if (!target_match) {
4420                         rc = -EHOSTUNREACH;
4421                         continue;
4422                 }
4423
4424                 if (ipc->need_reconnect) {
4425                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4426                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4427                         if (rc)
4428                                 break;
4429                 }
4430
4431                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4432                 if (!islink) {
4433                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4434                         break;
4435                 }
4436                 /*
4437                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4438                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4439                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4440                  * newly resolved target.
4441                  */
4442                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4443                                    NULL, &ntl)) {
4444                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4445                         if (rc)
4446                                 continue;
4447                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4448                         if (!rc)
4449                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4450                 } else {
4451                         /* Target is another dfs share */
4452                         rc = update_server_fullpath(server, cifs_sb, target);
4453                         dfs_cache_free_tgts(tl);
4454
4455                         if (!rc) {
4456                                 rc = -EREMOTE;
4457                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4458                         } else
4459                                 dfs_cache_free_tgts(&ntl);
4460                 }
4461                 break;
4462         }
4463
4464 out:
4465         kfree(share);
4466         kfree(prefix);
4467
4468         return rc;
4469 }
4470
4471 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4472                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4473                                    struct dfs_cache_tgt_list *tl)
4474 {
4475         int rc;
4476         int num_links = 0;
4477         struct TCP_Server_Info *server = tcon->ses->server;
4478
4479         do {
4480                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4481                 if (!rc || rc != -EREMOTE)
4482                         break;
4483         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4484         /*
4485          * If we couldn't tree connect to any targets from last referral path, then retry from
4486          * original referral path.
4487          */
4488         if (rc && server->current_fullpath != server->origin_fullpath) {
4489                 server->current_fullpath = server->origin_fullpath;
4490                 cifs_signal_cifsd_for_reconnect(server, true);
4491         }
4492
4493         dfs_cache_free_tgts(tl);
4494         return rc;
4495 }
4496
4497 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4498 {
4499         int rc;
4500         struct TCP_Server_Info *server = tcon->ses->server;
4501         const struct smb_version_operations *ops = server->ops;
4502         struct super_block *sb = NULL;
4503         struct cifs_sb_info *cifs_sb;
4504         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4505         char *tree;
4506         struct dfs_info3_param ref = {0};
4507
4508         /* only send once per connect */
4509         spin_lock(&cifs_tcp_ses_lock);
4510         if (tcon->ses->ses_status != SES_GOOD ||
4511             (tcon->status != TID_NEW &&
4512             tcon->status != TID_NEED_TCON)) {
4513                 spin_unlock(&cifs_tcp_ses_lock);
4514                 return 0;
4515         }
4516         tcon->status = TID_IN_TCON;
4517         spin_unlock(&cifs_tcp_ses_lock);
4518
4519         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4520         if (!tree) {
4521                 rc = -ENOMEM;
4522                 goto out;
4523         }
4524
4525         if (tcon->ipc) {
4526                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4527                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4528                 goto out;
4529         }
4530
4531         sb = cifs_get_tcp_super(server);
4532         if (IS_ERR(sb)) {
4533                 rc = PTR_ERR(sb);
4534                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4535                 goto out;
4536         }
4537
4538         cifs_sb = CIFS_SB(sb);
4539
4540         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4541         if (!server->current_fullpath ||
4542             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4543                 rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls);
4544                 goto out;
4545         }
4546
4547         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4548                                      &tl);
4549         free_dfs_info_param(&ref);
4550
4551 out:
4552         kfree(tree);
4553         cifs_put_tcp_super(sb);
4554
4555         if (rc) {
4556                 spin_lock(&cifs_tcp_ses_lock);
4557                 if (tcon->status == TID_IN_TCON)
4558                         tcon->status = TID_NEED_TCON;
4559                 spin_unlock(&cifs_tcp_ses_lock);
4560         } else {
4561                 spin_lock(&cifs_tcp_ses_lock);
4562                 if (tcon->status == TID_IN_TCON)
4563                         tcon->status = TID_GOOD;
4564                 spin_unlock(&cifs_tcp_ses_lock);
4565                 tcon->need_reconnect = false;
4566         }
4567
4568         return rc;
4569 }
4570 #else
4571 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4572 {
4573         int rc;
4574         const struct smb_version_operations *ops = tcon->ses->server->ops;
4575
4576         /* only send once per connect */
4577         spin_lock(&cifs_tcp_ses_lock);
4578         if (tcon->ses->ses_status != SES_GOOD ||
4579             (tcon->status != TID_NEW &&
4580             tcon->status != TID_NEED_TCON)) {
4581                 spin_unlock(&cifs_tcp_ses_lock);
4582                 return 0;
4583         }
4584         tcon->status = TID_IN_TCON;
4585         spin_unlock(&cifs_tcp_ses_lock);
4586
4587         rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4588         if (rc) {
4589                 spin_lock(&cifs_tcp_ses_lock);
4590                 if (tcon->status == TID_IN_TCON)
4591                         tcon->status = TID_NEED_TCON;
4592                 spin_unlock(&cifs_tcp_ses_lock);
4593         } else {
4594                 spin_lock(&cifs_tcp_ses_lock);
4595                 if (tcon->status == TID_IN_TCON)
4596                         tcon->status = TID_GOOD;
4597                 spin_unlock(&cifs_tcp_ses_lock);
4598                 tcon->need_reconnect = false;
4599         }
4600
4601         return rc;
4602 }
4603 #endif