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         /* if server hostname isn't populated, there's nothing to do here */
 101         if (server->hostname[0] == '\0')
 102                 return 0;
 103
 104         len = strlen(server->hostname) + 3;
 105
 106         unc = kmalloc(len, GFP_KERNEL);
 107         if (!unc) {
 108                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
 109                 return -ENOMEM;
 110         }
 111         scnprintf(unc, len, "\\\\%s", server->hostname);
 112
 113         rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
 114         kfree(unc);
 115
 116         if (rc < 0) {
 117                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 118                          __func__, server->hostname, rc);
 119                 goto requeue_resolve;
 120         }
 121
 122         spin_lock(&server->srv_lock);
 123         rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 124                                   strlen(ipaddr));
 125         spin_unlock(&server->srv_lock);
 126         kfree(ipaddr);
 127
 128         /* rc == 1 means success here */
 129         if (rc) {
 130                 now = ktime_get_real_seconds();
 131                 if (expiry && expiry > now)
 132                         /*
 133                          * To make sure we don't use the cached entry, retry 1s
 134                          * after expiry.
 135                          */
 136                         ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 137         }
 138         rc = !rc ? -1 : 0;
 139
 140 requeue_resolve:
 141         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 142                  __func__, ttl);
 143         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 144
 145         return rc;
 146 }
 147
 148 static void smb2_query_server_interfaces(struct work_struct *work)
 149 {
 150         int rc;
 151         struct cifs_tcon *tcon = container_of(work,
 152                                         struct cifs_tcon,
 153                                         query_interfaces.work);
 154
 155         /*
 156          * query server network interfaces, in case they change
 157          */
 158         rc = SMB3_request_interfaces(0, tcon, false);
 159         if (rc) {
 160                 cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 161                                 __func__, rc);
 162         }
 163
 164         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 165                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
 166 }
 167
 168 static void cifs_resolve_server(struct work_struct *work)
 169 {
 170         int rc;
 171         struct TCP_Server_Info *server = container_of(work,
 172                                         struct TCP_Server_Info, resolve.work);
 173
 174         cifs_server_lock(server);
 175
 176         /*
 177          * Resolve the hostname again to make sure that IP address is up-to-date.
 178          */
 179         rc = reconn_set_ipaddr_from_hostname(server);
 180         if (rc) {
 181                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 182                                 __func__, rc);
 183         }
 184
 185         cifs_server_unlock(server);
 186 }
 187
 188 /*
 189  * Update the tcpStatus for the server.
 190  * This is used to signal the cifsd thread to call cifs_reconnect
 191  * ONLY cifsd thread should call cifs_reconnect. For any other
 192  * thread, use this function
 193  *
 194  * @server: the tcp ses for which reconnect is needed
 195  * @all_channels: if this needs to be done for all channels
 196  */
 197 void
 198 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 199                                 bool all_channels)
 200 {
 201         struct TCP_Server_Info *pserver;
 202         struct cifs_ses *ses;
 203         int i;
 204
 205         /* If server is a channel, select the primary channel */
 206         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 207
 208         spin_lock(&pserver->srv_lock);
 209         if (!all_channels) {
 210                 pserver->tcpStatus = CifsNeedReconnect;
 211                 spin_unlock(&pserver->srv_lock);
 212                 return;
 213         }
 214         spin_unlock(&pserver->srv_lock);
 215
 216         spin_lock(&cifs_tcp_ses_lock);
 217         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 218                 spin_lock(&ses->chan_lock);
 219                 for (i = 0; i < ses->chan_count; i++) {
 220                         spin_lock(&ses->chans[i].server->srv_lock);
 221                         ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 222                         spin_unlock(&ses->chans[i].server->srv_lock);
 223                 }
 224                 spin_unlock(&ses->chan_lock);
 225         }
 226         spin_unlock(&cifs_tcp_ses_lock);
 227 }
 228
 229 /*
 230  * Mark all sessions and tcons for reconnect.
 231  * IMPORTANT: make sure that this gets called only from
 232  * cifsd thread. For any other thread, use
 233  * cifs_signal_cifsd_for_reconnect
 234  *
 235  * @server: the tcp ses for which reconnect is needed
 236  * @server needs to be previously set to CifsNeedReconnect.
 237  * @mark_smb_session: whether even sessions need to be marked
 238  */
 239 void
 240 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 241                                       bool mark_smb_session)
 242 {
 243         struct TCP_Server_Info *pserver;
 244         struct cifs_ses *ses, *nses;
 245         struct cifs_tcon *tcon;
 246
 247         /*
 248          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 249          * are not used until reconnected.
 250          */
 251         cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 252
 253         /* If server is a channel, select the primary channel */
 254         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 255
 256
 257         spin_lock(&cifs_tcp_ses_lock);
 258         list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 259                 /* check if iface is still active */
 260                 if (!cifs_chan_is_iface_active(ses, server))
 261                         cifs_chan_update_iface(ses, server);
 262
 263                 spin_lock(&ses->chan_lock);
 264                 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
 265                         goto next_session;
 266
 267                 if (mark_smb_session)
 268                         CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 269                 else
 270                         cifs_chan_set_need_reconnect(ses, server);
 271
 272                 /* If all channels need reconnect, then tcon needs reconnect */
 273                 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
 274                         goto next_session;
 275
 276                 ses->ses_status = SES_NEED_RECON;
 277
 278                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 279                         tcon->need_reconnect = true;
 280                         tcon->status = TID_NEED_RECON;
 281                 }
 282                 if (ses->tcon_ipc)
 283                         ses->tcon_ipc->need_reconnect = true;
 284
 285 next_session:
 286                 spin_unlock(&ses->chan_lock);
 287         }
 288         spin_unlock(&cifs_tcp_ses_lock);
 289 }
 290
 291 static void
 292 cifs_abort_connection(struct TCP_Server_Info *server)
 293 {
 294         struct mid_q_entry *mid, *nmid;
 295         struct list_head retry_list;
 296
 297         server->maxBuf = 0;
 298         server->max_read = 0;
 299
 300         /* do not want to be sending data on a socket we are freeing */
 301         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 302         cifs_server_lock(server);
 303         if (server->ssocket) {
 304                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 305                          server->ssocket->flags);
 306                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 307                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 308                          server->ssocket->flags);
 309                 sock_release(server->ssocket);
 310                 server->ssocket = NULL;
 311         }
 312         server->sequence_number = 0;
 313         server->session_estab = false;
 314         kfree_sensitive(server->session_key.response);
 315         server->session_key.response = NULL;
 316         server->session_key.len = 0;
 317         server->lstrp = jiffies;
 318
 319         /* mark submitted MIDs for retry and issue callback */
 320         INIT_LIST_HEAD(&retry_list);
 321         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 322         spin_lock(&server->mid_lock);
 323         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 324                 kref_get(&mid->refcount);
 325                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 326                         mid->mid_state = MID_RETRY_NEEDED;
 327                 list_move(&mid->qhead, &retry_list);
 328                 mid->mid_flags |= MID_DELETED;
 329         }
 330         spin_unlock(&server->mid_lock);
 331         cifs_server_unlock(server);
 332
 333         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 334         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 335                 list_del_init(&mid->qhead);
 336                 mid->callback(mid);
 337                 release_mid(mid);
 338         }
 339
 340         if (cifs_rdma_enabled(server)) {
 341                 cifs_server_lock(server);
 342                 smbd_destroy(server);
 343                 cifs_server_unlock(server);
 344         }
 345 }
 346
 347 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 348 {
 349         spin_lock(&server->srv_lock);
 350         server->nr_targets = num_targets;
 351         if (server->tcpStatus == CifsExiting) {
 352                 /* the demux thread will exit normally next time through the loop */
 353                 spin_unlock(&server->srv_lock);
 354                 wake_up(&server->response_q);
 355                 return false;
 356         }
 357
 358         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 359         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 360                              server->hostname);
 361         server->tcpStatus = CifsNeedReconnect;
 362
 363         spin_unlock(&server->srv_lock);
 364         return true;
 365 }
 366
 367 /*
 368  * cifs tcp session reconnection
 369  *
 370  * mark tcp session as reconnecting so temporarily locked
 371  * mark all smb sessions as reconnecting for tcp session
 372  * reconnect tcp session
 373  * wake up waiters on reconnection? - (not needed currently)
 374  *
 375  * if mark_smb_session is passed as true, unconditionally mark
 376  * the smb session (and tcon) for reconnect as well. This value
 377  * doesn't really matter for non-multichannel scenario.
 378  *
 379  */
 380 static int __cifs_reconnect(struct TCP_Server_Info *server,
 381                             bool mark_smb_session)
 382 {
 383         int rc = 0;
 384
 385         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 386                 return 0;
 387
 388         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 389
 390         cifs_abort_connection(server);
 391
 392         do {
 393                 try_to_freeze();
 394                 cifs_server_lock(server);
 395
 396                 if (!cifs_swn_set_server_dstaddr(server)) {
 397                         /* resolve the hostname again to make sure that IP address is up-to-date */
 398                         rc = reconn_set_ipaddr_from_hostname(server);
 399                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 400                 }
 401
 402                 if (cifs_rdma_enabled(server))
 403                         rc = smbd_reconnect(server);
 404                 else
 405                         rc = generic_ip_connect(server);
 406                 if (rc) {
 407                         cifs_server_unlock(server);
 408                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 409                         msleep(3000);
 410                 } else {
 411                         atomic_inc(&tcpSesReconnectCount);
 412                         set_credits(server, 1);
 413                         spin_lock(&server->srv_lock);
 414                         if (server->tcpStatus != CifsExiting)
 415                                 server->tcpStatus = CifsNeedNegotiate;
 416                         spin_unlock(&server->srv_lock);
 417                         cifs_swn_reset_server_dstaddr(server);
 418                         cifs_server_unlock(server);
 419                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 420                 }
 421         } while (server->tcpStatus == CifsNeedReconnect);
 422
 423         spin_lock(&server->srv_lock);
 424         if (server->tcpStatus == CifsNeedNegotiate)
 425                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 426         spin_unlock(&server->srv_lock);
 427
 428         wake_up(&server->response_q);
 429         return rc;
 430 }
 431
 432 #ifdef CONFIG_CIFS_DFS_UPCALL
 433 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 434 {
 435         int rc;
 436         char *hostname;
 437
 438         if (!cifs_swn_set_server_dstaddr(server)) {
 439                 if (server->hostname != target) {
 440                         hostname = extract_hostname(target);
 441                         if (!IS_ERR(hostname)) {
 442                                 kfree(server->hostname);
 443                                 server->hostname = hostname;
 444                         } else {
 445                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 446                                          __func__, PTR_ERR(hostname));
 447                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 448                                          server->hostname);
 449                         }
 450                 }
 451                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 452                 rc = reconn_set_ipaddr_from_hostname(server);
 453                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 454         }
 455         /* Reconnect the socket */
 456         if (cifs_rdma_enabled(server))
 457                 rc = smbd_reconnect(server);
 458         else
 459                 rc = generic_ip_connect(server);
 460
 461         return rc;
 462 }
 463
 464 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 465                                      struct dfs_cache_tgt_iterator **target_hint)
 466 {
 467         int rc;
 468         struct dfs_cache_tgt_iterator *tit;
 469
 470         *target_hint = NULL;
 471
 472         /* If dfs target list is empty, then reconnect to last server */
 473         tit = dfs_cache_get_tgt_iterator(tl);
 474         if (!tit)
 475                 return __reconnect_target_unlocked(server, server->hostname);
 476
 477         /* Otherwise, try every dfs target in @tl */
 478         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 479                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 480                 if (!rc) {
 481                         *target_hint = tit;
 482                         break;
 483                 }
 484         }
 485         return rc;
 486 }
 487
 488 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 489 {
 490         int rc = 0;
 491         const char *refpath = server->current_fullpath + 1;
 492         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 493         struct dfs_cache_tgt_iterator *target_hint = NULL;
 494         int num_targets = 0;
 495
 496         /*
 497          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 498          *
 499          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 500          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 501          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 502          * refreshing the referral, so, in this case, default it to 1.
 503          */
 504         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 505                 num_targets = dfs_cache_get_nr_tgts(&tl);
 506         if (!num_targets)
 507                 num_targets = 1;
 508
 509         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 510                 return 0;
 511
 512         /*
 513          * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 514          * different server or share during failover.  It could be improved by adding some logic to
 515          * only do that in case it connects to a different server or share, though.
 516          */
 517         cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 518
 519         cifs_abort_connection(server);
 520
 521         do {
 522                 try_to_freeze();
 523                 cifs_server_lock(server);
 524
 525                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 526                 if (rc) {
 527                         /* Failed to reconnect socket */
 528                         cifs_server_unlock(server);
 529                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 530                         msleep(3000);
 531                         continue;
 532                 }
 533                 /*
 534                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 535                  * process waiting for reconnect will know it needs to re-establish session and tcon
 536                  * through the reconnected target server.
 537                  */
 538                 atomic_inc(&tcpSesReconnectCount);
 539                 set_credits(server, 1);
 540                 spin_lock(&server->srv_lock);
 541                 if (server->tcpStatus != CifsExiting)
 542                         server->tcpStatus = CifsNeedNegotiate;
 543                 spin_unlock(&server->srv_lock);
 544                 cifs_swn_reset_server_dstaddr(server);
 545                 cifs_server_unlock(server);
 546                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 547         } while (server->tcpStatus == CifsNeedReconnect);
 548
 549         if (target_hint)
 550                 dfs_cache_noreq_update_tgthint(refpath, target_hint);
 551
 552         dfs_cache_free_tgts(&tl);
 553
 554         /* Need to set up echo worker again once connection has been established */
 555         spin_lock(&server->srv_lock);
 556         if (server->tcpStatus == CifsNeedNegotiate)
 557                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 558         spin_unlock(&server->srv_lock);
 559
 560         wake_up(&server->response_q);
 561         return rc;
 562 }
 563
 564 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 565 {
 566         /* If tcp session is not an dfs connection, then reconnect to last target server */
 567         spin_lock(&server->srv_lock);
 568         if (!server->is_dfs_conn) {
 569                 spin_unlock(&server->srv_lock);
 570                 return __cifs_reconnect(server, mark_smb_session);
 571         }
 572         spin_unlock(&server->srv_lock);
 573
 574         mutex_lock(&server->refpath_lock);
 575         if (!server->origin_fullpath || !server->leaf_fullpath) {
 576                 mutex_unlock(&server->refpath_lock);
 577                 return __cifs_reconnect(server, mark_smb_session);
 578         }
 579         mutex_unlock(&server->refpath_lock);
 580
 581         return reconnect_dfs_server(server);
 582 }
 583 #else
 584 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 585 {
 586         return __cifs_reconnect(server, mark_smb_session);
 587 }
 588 #endif
 589
 590 static void
 591 cifs_echo_request(struct work_struct *work)
 592 {
 593         int rc;
 594         struct TCP_Server_Info *server = container_of(work,
 595                                         struct TCP_Server_Info, echo.work);
 596
 597         /*
 598          * We cannot send an echo if it is disabled.
 599          * Also, no need to ping if we got a response recently.
 600          */
 601
 602         if (server->tcpStatus == CifsNeedReconnect ||
 603             server->tcpStatus == CifsExiting ||
 604             server->tcpStatus == CifsNew ||
 605             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 606             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 607                 goto requeue_echo;
 608
 609         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 610         if (rc)
 611                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 612                          server->hostname);
 613
 614         /* Check witness registrations */
 615         cifs_swn_check();
 616
 617 requeue_echo:
 618         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 619 }
 620
 621 static bool
 622 allocate_buffers(struct TCP_Server_Info *server)
 623 {
 624         if (!server->bigbuf) {
 625                 server->bigbuf = (char *)cifs_buf_get();
 626                 if (!server->bigbuf) {
 627                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 628                         msleep(3000);
 629                         /* retry will check if exiting */
 630                         return false;
 631                 }
 632         } else if (server->large_buf) {
 633                 /* we are reusing a dirty large buf, clear its start */
 634                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 635         }
 636
 637         if (!server->smallbuf) {
 638                 server->smallbuf = (char *)cifs_small_buf_get();
 639                 if (!server->smallbuf) {
 640                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 641                         msleep(1000);
 642                         /* retry will check if exiting */
 643                         return false;
 644                 }
 645                 /* beginning of smb buffer is cleared in our buf_get */
 646         } else {
 647                 /* if existing small buf clear beginning */
 648                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 649         }
 650
 651         return true;
 652 }
 653
 654 static bool
 655 server_unresponsive(struct TCP_Server_Info *server)
 656 {
 657         /*
 658          * We need to wait 3 echo intervals to make sure we handle such
 659          * situations right:
 660          * 1s  client sends a normal SMB request
 661          * 2s  client gets a response
 662          * 30s echo workqueue job pops, and decides we got a response recently
 663          *     and don't need to send another
 664          * ...
 665          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 666          *     a response in >60s.
 667          */
 668         spin_lock(&server->srv_lock);
 669         if ((server->tcpStatus == CifsGood ||
 670             server->tcpStatus == CifsNeedNegotiate) &&
 671             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 672             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 673                 spin_unlock(&server->srv_lock);
 674                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 675                          (3 * server->echo_interval) / HZ);
 676                 cifs_reconnect(server, false);
 677                 return true;
 678         }
 679         spin_unlock(&server->srv_lock);
 680
 681         return false;
 682 }
 683
 684 static inline bool
 685 zero_credits(struct TCP_Server_Info *server)
 686 {
 687         int val;
 688
 689         spin_lock(&server->req_lock);
 690         val = server->credits + server->echo_credits + server->oplock_credits;
 691         if (server->in_flight == 0 && val == 0) {
 692                 spin_unlock(&server->req_lock);
 693                 return true;
 694         }
 695         spin_unlock(&server->req_lock);
 696         return false;
 697 }
 698
 699 static int
 700 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 701 {
 702         int length = 0;
 703         int total_read;
 704
 705         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 706                 try_to_freeze();
 707
 708                 /* reconnect if no credits and no requests in flight */
 709                 if (zero_credits(server)) {
 710                         cifs_reconnect(server, false);
 711                         return -ECONNABORTED;
 712                 }
 713
 714                 if (server_unresponsive(server))
 715                         return -ECONNABORTED;
 716                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 717                         length = smbd_recv(server->smbd_conn, smb_msg);
 718                 else
 719                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 720
 721                 spin_lock(&server->srv_lock);
 722                 if (server->tcpStatus == CifsExiting) {
 723                         spin_unlock(&server->srv_lock);
 724                         return -ESHUTDOWN;
 725                 }
 726
 727                 if (server->tcpStatus == CifsNeedReconnect) {
 728                         spin_unlock(&server->srv_lock);
 729                         cifs_reconnect(server, false);
 730                         return -ECONNABORTED;
 731                 }
 732                 spin_unlock(&server->srv_lock);
 733
 734                 if (length == -ERESTARTSYS ||
 735                     length == -EAGAIN ||
 736                     length == -EINTR) {
 737                         /*
 738                          * Minimum sleep to prevent looping, allowing socket
 739                          * to clear and app threads to set tcpStatus
 740                          * CifsNeedReconnect if server hung.
 741                          */
 742                         usleep_range(1000, 2000);
 743                         length = 0;
 744                         continue;
 745                 }
 746
 747                 if (length <= 0) {
 748                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 749                         cifs_reconnect(server, false);
 750                         return -ECONNABORTED;
 751                 }
 752         }
 753         return total_read;
 754 }
 755
 756 int
 757 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 758                       unsigned int to_read)
 759 {
 760         struct msghdr smb_msg = {};
 761         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 762         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 763
 764         return cifs_readv_from_socket(server, &smb_msg);
 765 }
 766
 767 ssize_t
 768 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 769 {
 770         struct msghdr smb_msg = {};
 771
 772         /*
 773          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 774          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 775          *  so little to initialize in struct msghdr
 776          */
 777         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 778
 779         return cifs_readv_from_socket(server, &smb_msg);
 780 }
 781
 782 int
 783 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 784         unsigned int page_offset, unsigned int to_read)
 785 {
 786         struct msghdr smb_msg = {};
 787         struct bio_vec bv = {
 788                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 789         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 790         return cifs_readv_from_socket(server, &smb_msg);
 791 }
 792
 793 static bool
 794 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 795 {
 796         /*
 797          * The first byte big endian of the length field,
 798          * is actually not part of the length but the type
 799          * with the most common, zero, as regular data.
 800          */
 801         switch (type) {
 802         case RFC1002_SESSION_MESSAGE:
 803                 /* Regular SMB response */
 804                 return true;
 805         case RFC1002_SESSION_KEEP_ALIVE:
 806                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 807                 break;
 808         case RFC1002_POSITIVE_SESSION_RESPONSE:
 809                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 810                 break;
 811         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 812                 /*
 813                  * We get this from Windows 98 instead of an error on
 814                  * SMB negprot response.
 815                  */
 816                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 817                 /* give server a second to clean up */
 818                 msleep(1000);
 819                 /*
 820                  * Always try 445 first on reconnect since we get NACK
 821                  * on some if we ever connected to port 139 (the NACK
 822                  * is since we do not begin with RFC1001 session
 823                  * initialize frame).
 824                  */
 825                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 826                 cifs_reconnect(server, true);
 827                 break;
 828         default:
 829                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 830                 cifs_reconnect(server, true);
 831         }
 832
 833         return false;
 834 }
 835
 836 void
 837 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 838 {
 839 #ifdef CONFIG_CIFS_STATS2
 840         mid->when_received = jiffies;
 841 #endif
 842         spin_lock(&mid->server->mid_lock);
 843         if (!malformed)
 844                 mid->mid_state = MID_RESPONSE_RECEIVED;
 845         else
 846                 mid->mid_state = MID_RESPONSE_MALFORMED;
 847         /*
 848          * Trying to handle/dequeue a mid after the send_recv()
 849          * function has finished processing it is a bug.
 850          */
 851         if (mid->mid_flags & MID_DELETED) {
 852                 spin_unlock(&mid->server->mid_lock);
 853                 pr_warn_once("trying to dequeue a deleted mid\n");
 854         } else {
 855                 list_del_init(&mid->qhead);
 856                 mid->mid_flags |= MID_DELETED;
 857                 spin_unlock(&mid->server->mid_lock);
 858         }
 859 }
 860
 861 static unsigned int
 862 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 863 {
 864         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 865
 866         /*
 867          * SMB1 does not use credits.
 868          */
 869         if (is_smb1(server))
 870                 return 0;
 871
 872         return le16_to_cpu(shdr->CreditRequest);
 873 }
 874
 875 static void
 876 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 877            char *buf, int malformed)
 878 {
 879         if (server->ops->check_trans2 &&
 880             server->ops->check_trans2(mid, server, buf, malformed))
 881                 return;
 882         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 883         mid->resp_buf = buf;
 884         mid->large_buf = server->large_buf;
 885         /* Was previous buf put in mpx struct for multi-rsp? */
 886         if (!mid->multiRsp) {
 887                 /* smb buffer will be freed by user thread */
 888                 if (server->large_buf)
 889                         server->bigbuf = NULL;
 890                 else
 891                         server->smallbuf = NULL;
 892         }
 893         dequeue_mid(mid, malformed);
 894 }
 895
 896 int
 897 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 898 {
 899         bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 900         bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 901         bool mnt_sign_enabled;
 902
 903         /*
 904          * Is signing required by mnt options? If not then check
 905          * global_secflags to see if it is there.
 906          */
 907         if (!mnt_sign_required)
 908                 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 909                                                 CIFSSEC_MUST_SIGN);
 910
 911         /*
 912          * If signing is required then it's automatically enabled too,
 913          * otherwise, check to see if the secflags allow it.
 914          */
 915         mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 916                                 (global_secflags & CIFSSEC_MAY_SIGN);
 917
 918         /* If server requires signing, does client allow it? */
 919         if (srv_sign_required) {
 920                 if (!mnt_sign_enabled) {
 921                         cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 922                         return -EOPNOTSUPP;
 923                 }
 924                 server->sign = true;
 925         }
 926
 927         /* If client requires signing, does server allow it? */
 928         if (mnt_sign_required) {
 929                 if (!srv_sign_enabled) {
 930                         cifs_dbg(VFS, "Server does not support signing!\n");
 931                         return -EOPNOTSUPP;
 932                 }
 933                 server->sign = true;
 934         }
 935
 936         if (cifs_rdma_enabled(server) && server->sign)
 937                 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 938
 939         return 0;
 940 }
 941
 942
 943 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 944 {
 945         int length;
 946
 947         /* take it off the list, if it's not already */
 948         spin_lock(&server->srv_lock);
 949         list_del_init(&server->tcp_ses_list);
 950         spin_unlock(&server->srv_lock);
 951
 952         cancel_delayed_work_sync(&server->echo);
 953         cancel_delayed_work_sync(&server->resolve);
 954
 955         spin_lock(&server->srv_lock);
 956         server->tcpStatus = CifsExiting;
 957         spin_unlock(&server->srv_lock);
 958         wake_up_all(&server->response_q);
 959
 960         /* check if we have blocked requests that need to free */
 961         spin_lock(&server->req_lock);
 962         if (server->credits <= 0)
 963                 server->credits = 1;
 964         spin_unlock(&server->req_lock);
 965         /*
 966          * Although there should not be any requests blocked on this queue it
 967          * can not hurt to be paranoid and try to wake up requests that may
 968          * haven been blocked when more than 50 at time were on the wire to the
 969          * same server - they now will see the session is in exit state and get
 970          * out of SendReceive.
 971          */
 972         wake_up_all(&server->request_q);
 973         /* give those requests time to exit */
 974         msleep(125);
 975         if (cifs_rdma_enabled(server))
 976                 smbd_destroy(server);
 977         if (server->ssocket) {
 978                 sock_release(server->ssocket);
 979                 server->ssocket = NULL;
 980         }
 981
 982         if (!list_empty(&server->pending_mid_q)) {
 983                 struct list_head dispose_list;
 984                 struct mid_q_entry *mid_entry;
 985                 struct list_head *tmp, *tmp2;
 986
 987                 INIT_LIST_HEAD(&dispose_list);
 988                 spin_lock(&server->mid_lock);
 989                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 990                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 991                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 992                         kref_get(&mid_entry->refcount);
 993                         mid_entry->mid_state = MID_SHUTDOWN;
 994                         list_move(&mid_entry->qhead, &dispose_list);
 995                         mid_entry->mid_flags |= MID_DELETED;
 996                 }
 997                 spin_unlock(&server->mid_lock);
 998
 999                 /* now walk dispose list and issue callbacks */
1000                 list_for_each_safe(tmp, tmp2, &dispose_list) {
1001                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1002                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
1003                         list_del_init(&mid_entry->qhead);
1004                         mid_entry->callback(mid_entry);
1005                         release_mid(mid_entry);
1006                 }
1007                 /* 1/8th of sec is more than enough time for them to exit */
1008                 msleep(125);
1009         }
1010
1011         if (!list_empty(&server->pending_mid_q)) {
1012                 /*
1013                  * mpx threads have not exited yet give them at least the smb
1014                  * send timeout time for long ops.
1015                  *
1016                  * Due to delays on oplock break requests, we need to wait at
1017                  * least 45 seconds before giving up on a request getting a
1018                  * response and going ahead and killing cifsd.
1019                  */
1020                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
1021                 msleep(46000);
1022                 /*
1023                  * If threads still have not exited they are probably never
1024                  * coming home not much else we can do but free the memory.
1025                  */
1026         }
1027
1028 #ifdef CONFIG_CIFS_DFS_UPCALL
1029         kfree(server->origin_fullpath);
1030         kfree(server->leaf_fullpath);
1031 #endif
1032         kfree(server);
1033
1034         length = atomic_dec_return(&tcpSesAllocCount);
1035         if (length > 0)
1036                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1037 }
1038
1039 static int
1040 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1041 {
1042         int length;
1043         char *buf = server->smallbuf;
1044         unsigned int pdu_length = server->pdu_size;
1045
1046         /* make sure this will fit in a large buffer */
1047         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1048             HEADER_PREAMBLE_SIZE(server)) {
1049                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1050                 cifs_reconnect(server, true);
1051                 return -ECONNABORTED;
1052         }
1053
1054         /* switch to large buffer if too big for a small one */
1055         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1056                 server->large_buf = true;
1057                 memcpy(server->bigbuf, buf, server->total_read);
1058                 buf = server->bigbuf;
1059         }
1060
1061         /* now read the rest */
1062         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1063                                        pdu_length - MID_HEADER_SIZE(server));
1064
1065         if (length < 0)
1066                 return length;
1067         server->total_read += length;
1068
1069         dump_smb(buf, server->total_read);
1070
1071         return cifs_handle_standard(server, mid);
1072 }
1073
1074 int
1075 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1076 {
1077         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1078         int rc;
1079
1080         /*
1081          * We know that we received enough to get to the MID as we
1082          * checked the pdu_length earlier. Now check to see
1083          * if the rest of the header is OK.
1084          *
1085          * 48 bytes is enough to display the header and a little bit
1086          * into the payload for debugging purposes.
1087          */
1088         rc = server->ops->check_message(buf, server->total_read, server);
1089         if (rc)
1090                 cifs_dump_mem("Bad SMB: ", buf,
1091                         min_t(unsigned int, server->total_read, 48));
1092
1093         if (server->ops->is_session_expired &&
1094             server->ops->is_session_expired(buf)) {
1095                 cifs_reconnect(server, true);
1096                 return -1;
1097         }
1098
1099         if (server->ops->is_status_pending &&
1100             server->ops->is_status_pending(buf, server))
1101                 return -1;
1102
1103         if (!mid)
1104                 return rc;
1105
1106         handle_mid(mid, server, buf, rc);
1107         return 0;
1108 }
1109
1110 static void
1111 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1112 {
1113         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1114         int scredits, in_flight;
1115
1116         /*
1117          * SMB1 does not use credits.
1118          */
1119         if (is_smb1(server))
1120                 return;
1121
1122         if (shdr->CreditRequest) {
1123                 spin_lock(&server->req_lock);
1124                 server->credits += le16_to_cpu(shdr->CreditRequest);
1125                 scredits = server->credits;
1126                 in_flight = server->in_flight;
1127                 spin_unlock(&server->req_lock);
1128                 wake_up(&server->request_q);
1129
1130                 trace_smb3_hdr_credits(server->CurrentMid,
1131                                 server->conn_id, server->hostname, scredits,
1132                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1133                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1134                                 __func__, le16_to_cpu(shdr->CreditRequest),
1135                                 scredits);
1136         }
1137 }
1138
1139
1140 static int
1141 cifs_demultiplex_thread(void *p)
1142 {
1143         int i, num_mids, length;
1144         struct TCP_Server_Info *server = p;
1145         unsigned int pdu_length;
1146         unsigned int next_offset;
1147         char *buf = NULL;
1148         struct task_struct *task_to_wake = NULL;
1149         struct mid_q_entry *mids[MAX_COMPOUND];
1150         char *bufs[MAX_COMPOUND];
1151         unsigned int noreclaim_flag, num_io_timeout = 0;
1152
1153         noreclaim_flag = memalloc_noreclaim_save();
1154         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1155
1156         length = atomic_inc_return(&tcpSesAllocCount);
1157         if (length > 1)
1158                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1159
1160         set_freezable();
1161         allow_kernel_signal(SIGKILL);
1162         while (server->tcpStatus != CifsExiting) {
1163                 if (try_to_freeze())
1164                         continue;
1165
1166                 if (!allocate_buffers(server))
1167                         continue;
1168
1169                 server->large_buf = false;
1170                 buf = server->smallbuf;
1171                 pdu_length = 4; /* enough to get RFC1001 header */
1172
1173                 length = cifs_read_from_socket(server, buf, pdu_length);
1174                 if (length < 0)
1175                         continue;
1176
1177                 if (is_smb1(server))
1178                         server->total_read = length;
1179                 else
1180                         server->total_read = 0;
1181
1182                 /*
1183                  * The right amount was read from socket - 4 bytes,
1184                  * so we can now interpret the length field.
1185                  */
1186                 pdu_length = get_rfc1002_length(buf);
1187
1188                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1189                 if (!is_smb_response(server, buf[0]))
1190                         continue;
1191 next_pdu:
1192                 server->pdu_size = pdu_length;
1193
1194                 /* make sure we have enough to get to the MID */
1195                 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1196                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1197                                  server->pdu_size);
1198                         cifs_reconnect(server, true);
1199                         continue;
1200                 }
1201
1202                 /* read down to the MID */
1203                 length = cifs_read_from_socket(server,
1204                              buf + HEADER_PREAMBLE_SIZE(server),
1205                              MID_HEADER_SIZE(server));
1206                 if (length < 0)
1207                         continue;
1208                 server->total_read += length;
1209
1210                 if (server->ops->next_header) {
1211                         next_offset = server->ops->next_header(buf);
1212                         if (next_offset)
1213                                 server->pdu_size = next_offset;
1214                 }
1215
1216                 memset(mids, 0, sizeof(mids));
1217                 memset(bufs, 0, sizeof(bufs));
1218                 num_mids = 0;
1219
1220                 if (server->ops->is_transform_hdr &&
1221                     server->ops->receive_transform &&
1222                     server->ops->is_transform_hdr(buf)) {
1223                         length = server->ops->receive_transform(server,
1224                                                                 mids,
1225                                                                 bufs,
1226                                                                 &num_mids);
1227                 } else {
1228                         mids[0] = server->ops->find_mid(server, buf);
1229                         bufs[0] = buf;
1230                         num_mids = 1;
1231
1232                         if (!mids[0] || !mids[0]->receive)
1233                                 length = standard_receive3(server, mids[0]);
1234                         else
1235                                 length = mids[0]->receive(server, mids[0]);
1236                 }
1237
1238                 if (length < 0) {
1239                         for (i = 0; i < num_mids; i++)
1240                                 if (mids[i])
1241                                         release_mid(mids[i]);
1242                         continue;
1243                 }
1244
1245                 if (server->ops->is_status_io_timeout &&
1246                     server->ops->is_status_io_timeout(buf)) {
1247                         num_io_timeout++;
1248                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1249                                 cifs_reconnect(server, false);
1250                                 num_io_timeout = 0;
1251                                 continue;
1252                         }
1253                 }
1254
1255                 server->lstrp = jiffies;
1256
1257                 for (i = 0; i < num_mids; i++) {
1258                         if (mids[i] != NULL) {
1259                                 mids[i]->resp_buf_size = server->pdu_size;
1260
1261                                 if (bufs[i] && server->ops->is_network_name_deleted)
1262                                         server->ops->is_network_name_deleted(bufs[i],
1263                                                                         server);
1264
1265                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1266                                         mids[i]->callback(mids[i]);
1267
1268                                 release_mid(mids[i]);
1269                         } else if (server->ops->is_oplock_break &&
1270                                    server->ops->is_oplock_break(bufs[i],
1271                                                                 server)) {
1272                                 smb2_add_credits_from_hdr(bufs[i], server);
1273                                 cifs_dbg(FYI, "Received oplock break\n");
1274                         } else {
1275                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1276                                                 atomic_read(&mid_count));
1277                                 cifs_dump_mem("Received Data is: ", bufs[i],
1278                                               HEADER_SIZE(server));
1279                                 smb2_add_credits_from_hdr(bufs[i], server);
1280 #ifdef CONFIG_CIFS_DEBUG2
1281                                 if (server->ops->dump_detail)
1282                                         server->ops->dump_detail(bufs[i],
1283                                                                  server);
1284                                 cifs_dump_mids(server);
1285 #endif /* CIFS_DEBUG2 */
1286                         }
1287                 }
1288
1289                 if (pdu_length > server->pdu_size) {
1290                         if (!allocate_buffers(server))
1291                                 continue;
1292                         pdu_length -= server->pdu_size;
1293                         server->total_read = 0;
1294                         server->large_buf = false;
1295                         buf = server->smallbuf;
1296                         goto next_pdu;
1297                 }
1298         } /* end while !EXITING */
1299
1300         /* buffer usually freed in free_mid - need to free it here on exit */
1301         cifs_buf_release(server->bigbuf);
1302         if (server->smallbuf) /* no sense logging a debug message if NULL */
1303                 cifs_small_buf_release(server->smallbuf);
1304
1305         task_to_wake = xchg(&server->tsk, NULL);
1306         clean_demultiplex_info(server);
1307
1308         /* if server->tsk was NULL then wait for a signal before exiting */
1309         if (!task_to_wake) {
1310                 set_current_state(TASK_INTERRUPTIBLE);
1311                 while (!signal_pending(current)) {
1312                         schedule();
1313                         set_current_state(TASK_INTERRUPTIBLE);
1314                 }
1315                 set_current_state(TASK_RUNNING);
1316         }
1317
1318         memalloc_noreclaim_restore(noreclaim_flag);
1319         module_put_and_kthread_exit(0);
1320 }
1321
1322 /*
1323  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1324  * if srcaddr is specified and matches the IP address of the rhs argument
1325  */
1326 bool
1327 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1328 {
1329         switch (srcaddr->sa_family) {
1330         case AF_UNSPEC:
1331                 return (rhs->sa_family == AF_UNSPEC);
1332         case AF_INET: {
1333                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1334                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1335                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1336         }
1337         case AF_INET6: {
1338                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1339                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1340                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1341         }
1342         default:
1343                 WARN_ON(1);
1344                 return false; /* don't expect to be here */
1345         }
1346 }
1347
1348 /*
1349  * If no port is specified in addr structure, we try to match with 445 port
1350  * and if it fails - with 139 ports. It should be called only if address
1351  * families of server and addr are equal.
1352  */
1353 static bool
1354 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1355 {
1356         __be16 port, *sport;
1357
1358         /* SMBDirect manages its own ports, don't match it here */
1359         if (server->rdma)
1360                 return true;
1361
1362         switch (addr->sa_family) {
1363         case AF_INET:
1364                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1365                 port = ((struct sockaddr_in *) addr)->sin_port;
1366                 break;
1367         case AF_INET6:
1368                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1369                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1370                 break;
1371         default:
1372                 WARN_ON(1);
1373                 return false;
1374         }
1375
1376         if (!port) {
1377                 port = htons(CIFS_PORT);
1378                 if (port == *sport)
1379                         return true;
1380
1381                 port = htons(RFC1001_PORT);
1382         }
1383
1384         return port == *sport;
1385 }
1386
1387 static bool
1388 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1389               struct sockaddr *srcaddr)
1390 {
1391         switch (addr->sa_family) {
1392         case AF_INET: {
1393                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1394                 struct sockaddr_in *srv_addr4 =
1395                                         (struct sockaddr_in *)&server->dstaddr;
1396
1397                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1398                         return false;
1399                 break;
1400         }
1401         case AF_INET6: {
1402                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1403                 struct sockaddr_in6 *srv_addr6 =
1404                                         (struct sockaddr_in6 *)&server->dstaddr;
1405
1406                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1407                                      &srv_addr6->sin6_addr))
1408                         return false;
1409                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1410                         return false;
1411                 break;
1412         }
1413         default:
1414                 WARN_ON(1);
1415                 return false; /* don't expect to be here */
1416         }
1417
1418         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1419                 return false;
1420
1421         return true;
1422 }
1423
1424 static bool
1425 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1426 {
1427         /*
1428          * The select_sectype function should either return the ctx->sectype
1429          * that was specified, or "Unspecified" if that sectype was not
1430          * compatible with the given NEGOTIATE request.
1431          */
1432         if (server->ops->select_sectype(server, ctx->sectype)
1433              == Unspecified)
1434                 return false;
1435
1436         /*
1437          * Now check if signing mode is acceptable. No need to check
1438          * global_secflags at this point since if MUST_SIGN is set then
1439          * the server->sign had better be too.
1440          */
1441         if (ctx->sign && !server->sign)
1442                 return false;
1443
1444         return true;
1445 }
1446
1447 /* this function must be called with srv_lock held */
1448 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1449 {
1450         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1451
1452         if (ctx->nosharesock)
1453                 return 0;
1454
1455         /* this server does not share socket */
1456         if (server->nosharesock)
1457                 return 0;
1458
1459         /* If multidialect negotiation see if existing sessions match one */
1460         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1461                 if (server->vals->protocol_id < SMB30_PROT_ID)
1462                         return 0;
1463         } else if (strcmp(ctx->vals->version_string,
1464                    SMBDEFAULT_VERSION_STRING) == 0) {
1465                 if (server->vals->protocol_id < SMB21_PROT_ID)
1466                         return 0;
1467         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1468                 return 0;
1469
1470         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1471                 return 0;
1472
1473         if (strcasecmp(server->hostname, ctx->server_hostname))
1474                 return 0;
1475
1476         if (!match_address(server, addr,
1477                            (struct sockaddr *)&ctx->srcaddr))
1478                 return 0;
1479
1480         if (!match_port(server, addr))
1481                 return 0;
1482
1483         if (!match_security(server, ctx))
1484                 return 0;
1485
1486         if (server->echo_interval != ctx->echo_interval * HZ)
1487                 return 0;
1488
1489         if (server->rdma != ctx->rdma)
1490                 return 0;
1491
1492         if (server->ignore_signature != ctx->ignore_signature)
1493                 return 0;
1494
1495         if (server->min_offload != ctx->min_offload)
1496                 return 0;
1497
1498         return 1;
1499 }
1500
1501 struct TCP_Server_Info *
1502 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1503 {
1504         struct TCP_Server_Info *server;
1505
1506         spin_lock(&cifs_tcp_ses_lock);
1507         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1508                 spin_lock(&server->srv_lock);
1509 #ifdef CONFIG_CIFS_DFS_UPCALL
1510                 /*
1511                  * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
1512                  * DFS connections to do failover properly, so avoid sharing them with regular
1513                  * shares or even links that may connect to same server but having completely
1514                  * different failover targets.
1515                  */
1516                 if (server->is_dfs_conn) {
1517                         spin_unlock(&server->srv_lock);
1518                         continue;
1519                 }
1520 #endif
1521                 /*
1522                  * Skip ses channels since they're only handled in lower layers
1523                  * (e.g. cifs_send_recv).
1524                  */
1525                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx)) {
1526                         spin_unlock(&server->srv_lock);
1527                         continue;
1528                 }
1529                 spin_unlock(&server->srv_lock);
1530
1531                 ++server->srv_count;
1532                 spin_unlock(&cifs_tcp_ses_lock);
1533                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1534                 return server;
1535         }
1536         spin_unlock(&cifs_tcp_ses_lock);
1537         return NULL;
1538 }
1539
1540 void
1541 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1542 {
1543         struct task_struct *task;
1544
1545         spin_lock(&cifs_tcp_ses_lock);
1546         if (--server->srv_count > 0) {
1547                 spin_unlock(&cifs_tcp_ses_lock);
1548                 return;
1549         }
1550
1551         /* srv_count can never go negative */
1552         WARN_ON(server->srv_count < 0);
1553
1554         put_net(cifs_net_ns(server));
1555
1556         list_del_init(&server->tcp_ses_list);
1557         spin_unlock(&cifs_tcp_ses_lock);
1558
1559         /* For secondary channels, we pick up ref-count on the primary server */
1560         if (CIFS_SERVER_IS_CHAN(server))
1561                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1562
1563         cancel_delayed_work_sync(&server->echo);
1564         cancel_delayed_work_sync(&server->resolve);
1565
1566         if (from_reconnect)
1567                 /*
1568                  * Avoid deadlock here: reconnect work calls
1569                  * cifs_put_tcp_session() at its end. Need to be sure
1570                  * that reconnect work does nothing with server pointer after
1571                  * that step.
1572                  */
1573                 cancel_delayed_work(&server->reconnect);
1574         else
1575                 cancel_delayed_work_sync(&server->reconnect);
1576
1577         spin_lock(&server->srv_lock);
1578         server->tcpStatus = CifsExiting;
1579         spin_unlock(&server->srv_lock);
1580
1581         cifs_crypto_secmech_release(server);
1582
1583         kfree_sensitive(server->session_key.response);
1584         server->session_key.response = NULL;
1585         server->session_key.len = 0;
1586         kfree(server->hostname);
1587
1588         task = xchg(&server->tsk, NULL);
1589         if (task)
1590                 send_sig(SIGKILL, task, 1);
1591 }
1592
1593 struct TCP_Server_Info *
1594 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1595                      struct TCP_Server_Info *primary_server)
1596 {
1597         struct TCP_Server_Info *tcp_ses = NULL;
1598         int rc;
1599
1600         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1601
1602         /* see if we already have a matching tcp_ses */
1603         tcp_ses = cifs_find_tcp_session(ctx);
1604         if (tcp_ses)
1605                 return tcp_ses;
1606
1607         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1608         if (!tcp_ses) {
1609                 rc = -ENOMEM;
1610                 goto out_err;
1611         }
1612
1613         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1614         if (!tcp_ses->hostname) {
1615                 rc = -ENOMEM;
1616                 goto out_err;
1617         }
1618
1619         if (ctx->nosharesock)
1620                 tcp_ses->nosharesock = true;
1621
1622         tcp_ses->ops = ctx->ops;
1623         tcp_ses->vals = ctx->vals;
1624         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1625
1626         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1627         tcp_ses->noblockcnt = ctx->rootfs;
1628         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1629         tcp_ses->noautotune = ctx->noautotune;
1630         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1631         tcp_ses->rdma = ctx->rdma;
1632         tcp_ses->in_flight = 0;
1633         tcp_ses->max_in_flight = 0;
1634         tcp_ses->credits = 1;
1635         if (primary_server) {
1636                 spin_lock(&cifs_tcp_ses_lock);
1637                 ++primary_server->srv_count;
1638                 spin_unlock(&cifs_tcp_ses_lock);
1639                 tcp_ses->primary_server = primary_server;
1640         }
1641         init_waitqueue_head(&tcp_ses->response_q);
1642         init_waitqueue_head(&tcp_ses->request_q);
1643         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1644         mutex_init(&tcp_ses->_srv_mutex);
1645         memcpy(tcp_ses->workstation_RFC1001_name,
1646                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1647         memcpy(tcp_ses->server_RFC1001_name,
1648                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1649         tcp_ses->session_estab = false;
1650         tcp_ses->sequence_number = 0;
1651         tcp_ses->reconnect_instance = 1;
1652         tcp_ses->lstrp = jiffies;
1653         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1654         spin_lock_init(&tcp_ses->req_lock);
1655         spin_lock_init(&tcp_ses->srv_lock);
1656         spin_lock_init(&tcp_ses->mid_lock);
1657         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1658         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1659         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1660         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1661         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1662         mutex_init(&tcp_ses->reconnect_mutex);
1663 #ifdef CONFIG_CIFS_DFS_UPCALL
1664         mutex_init(&tcp_ses->refpath_lock);
1665 #endif
1666         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1667                sizeof(tcp_ses->srcaddr));
1668         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1669                 sizeof(tcp_ses->dstaddr));
1670         if (ctx->use_client_guid)
1671                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1672                        SMB2_CLIENT_GUID_SIZE);
1673         else
1674                 generate_random_uuid(tcp_ses->client_guid);
1675         /*
1676          * at this point we are the only ones with the pointer
1677          * to the struct since the kernel thread not created yet
1678          * no need to spinlock this init of tcpStatus or srv_count
1679          */
1680         tcp_ses->tcpStatus = CifsNew;
1681         ++tcp_ses->srv_count;
1682
1683         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1684                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1685                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1686         else
1687                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1688         if (tcp_ses->rdma) {
1689 #ifndef CONFIG_CIFS_SMB_DIRECT
1690                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1691                 rc = -ENOENT;
1692                 goto out_err_crypto_release;
1693 #endif
1694                 tcp_ses->smbd_conn = smbd_get_connection(
1695                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1696                 if (tcp_ses->smbd_conn) {
1697                         cifs_dbg(VFS, "RDMA transport established\n");
1698                         rc = 0;
1699                         goto smbd_connected;
1700                 } else {
1701                         rc = -ENOENT;
1702                         goto out_err_crypto_release;
1703                 }
1704         }
1705         rc = ip_connect(tcp_ses);
1706         if (rc < 0) {
1707                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1708                 goto out_err_crypto_release;
1709         }
1710 smbd_connected:
1711         /*
1712          * since we're in a cifs function already, we know that
1713          * this will succeed. No need for try_module_get().
1714          */
1715         __module_get(THIS_MODULE);
1716         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1717                                   tcp_ses, "cifsd");
1718         if (IS_ERR(tcp_ses->tsk)) {
1719                 rc = PTR_ERR(tcp_ses->tsk);
1720                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1721                 module_put(THIS_MODULE);
1722                 goto out_err_crypto_release;
1723         }
1724         tcp_ses->min_offload = ctx->min_offload;
1725         /*
1726          * at this point we are the only ones with the pointer
1727          * to the struct since the kernel thread not created yet
1728          * no need to spinlock this update of tcpStatus
1729          */
1730         spin_lock(&tcp_ses->srv_lock);
1731         tcp_ses->tcpStatus = CifsNeedNegotiate;
1732         spin_unlock(&tcp_ses->srv_lock);
1733
1734         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1735                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1736         else
1737                 tcp_ses->max_credits = ctx->max_credits;
1738
1739         tcp_ses->nr_targets = 1;
1740         tcp_ses->ignore_signature = ctx->ignore_signature;
1741         /* thread spawned, put it on the list */
1742         spin_lock(&cifs_tcp_ses_lock);
1743         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1744         spin_unlock(&cifs_tcp_ses_lock);
1745
1746         /* queue echo request delayed work */
1747         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1748
1749         /* queue dns resolution delayed work */
1750         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1751                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1752
1753         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1754
1755         return tcp_ses;
1756
1757 out_err_crypto_release:
1758         cifs_crypto_secmech_release(tcp_ses);
1759
1760         put_net(cifs_net_ns(tcp_ses));
1761
1762 out_err:
1763         if (tcp_ses) {
1764                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1765                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1766                 kfree(tcp_ses->hostname);
1767                 if (tcp_ses->ssocket)
1768                         sock_release(tcp_ses->ssocket);
1769                 kfree(tcp_ses);
1770         }
1771         return ERR_PTR(rc);
1772 }
1773
1774 /* this function must be called with ses_lock held */
1775 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1776 {
1777         if (ctx->sectype != Unspecified &&
1778             ctx->sectype != ses->sectype)
1779                 return 0;
1780
1781         /*
1782          * If an existing session is limited to less channels than
1783          * requested, it should not be reused
1784          */
1785         spin_lock(&ses->chan_lock);
1786         if (ses->chan_max < ctx->max_channels) {
1787                 spin_unlock(&ses->chan_lock);
1788                 return 0;
1789         }
1790         spin_unlock(&ses->chan_lock);
1791
1792         switch (ses->sectype) {
1793         case Kerberos:
1794                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1795                         return 0;
1796                 break;
1797         default:
1798                 /* NULL username means anonymous session */
1799                 if (ses->user_name == NULL) {
1800                         if (!ctx->nullauth)
1801                                 return 0;
1802                         break;
1803                 }
1804
1805                 /* anything else takes username/password */
1806                 if (strncmp(ses->user_name,
1807                             ctx->username ? ctx->username : "",
1808                             CIFS_MAX_USERNAME_LEN))
1809                         return 0;
1810                 if ((ctx->username && strlen(ctx->username) != 0) &&
1811                     ses->password != NULL &&
1812                     strncmp(ses->password,
1813                             ctx->password ? ctx->password : "",
1814                             CIFS_MAX_PASSWORD_LEN))
1815                         return 0;
1816         }
1817         return 1;
1818 }
1819
1820 /**
1821  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1822  * @ses: smb session to issue the request on
1823  * @ctx: the superblock configuration context to use for building the
1824  *       new tree connection for the IPC (interprocess communication RPC)
1825  *
1826  * A new IPC connection is made and stored in the session
1827  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1828  */
1829 static int
1830 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1831 {
1832         int rc = 0, xid;
1833         struct cifs_tcon *tcon;
1834         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1835         bool seal = false;
1836         struct TCP_Server_Info *server = ses->server;
1837
1838         /*
1839          * If the mount request that resulted in the creation of the
1840          * session requires encryption, force IPC to be encrypted too.
1841          */
1842         if (ctx->seal) {
1843                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1844                         seal = true;
1845                 else {
1846                         cifs_server_dbg(VFS,
1847                                  "IPC: server doesn't support encryption\n");
1848                         return -EOPNOTSUPP;
1849                 }
1850         }
1851
1852         tcon = tconInfoAlloc();
1853         if (tcon == NULL)
1854                 return -ENOMEM;
1855
1856         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1857
1858         xid = get_xid();
1859         tcon->ses = ses;
1860         tcon->ipc = true;
1861         tcon->seal = seal;
1862         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1863         free_xid(xid);
1864
1865         if (rc) {
1866                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1867                 tconInfoFree(tcon);
1868                 goto out;
1869         }
1870
1871         cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1872
1873         ses->tcon_ipc = tcon;
1874 out:
1875         return rc;
1876 }
1877
1878 /**
1879  * cifs_free_ipc - helper to release the session IPC tcon
1880  * @ses: smb session to unmount the IPC from
1881  *
1882  * Needs to be called everytime a session is destroyed.
1883  *
1884  * On session close, the IPC is closed and the server must release all tcons of the session.
1885  * No need to send a tree disconnect here.
1886  *
1887  * Besides, it will make the server to not close durable and resilient files on session close, as
1888  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1889  */
1890 static int
1891 cifs_free_ipc(struct cifs_ses *ses)
1892 {
1893         struct cifs_tcon *tcon = ses->tcon_ipc;
1894
1895         if (tcon == NULL)
1896                 return 0;
1897
1898         tconInfoFree(tcon);
1899         ses->tcon_ipc = NULL;
1900         return 0;
1901 }
1902
1903 static struct cifs_ses *
1904 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1905 {
1906         struct cifs_ses *ses;
1907
1908         spin_lock(&cifs_tcp_ses_lock);
1909         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1910                 spin_lock(&ses->ses_lock);
1911                 if (ses->ses_status == SES_EXITING) {
1912                         spin_unlock(&ses->ses_lock);
1913                         continue;
1914                 }
1915                 if (!match_session(ses, ctx)) {
1916                         spin_unlock(&ses->ses_lock);
1917                         continue;
1918                 }
1919                 spin_unlock(&ses->ses_lock);
1920
1921                 ++ses->ses_count;
1922                 spin_unlock(&cifs_tcp_ses_lock);
1923                 return ses;
1924         }
1925         spin_unlock(&cifs_tcp_ses_lock);
1926         return NULL;
1927 }
1928
1929 void cifs_put_smb_ses(struct cifs_ses *ses)
1930 {
1931         unsigned int rc, xid;
1932         unsigned int chan_count;
1933         struct TCP_Server_Info *server = ses->server;
1934
1935         spin_lock(&ses->ses_lock);
1936         if (ses->ses_status == SES_EXITING) {
1937                 spin_unlock(&ses->ses_lock);
1938                 return;
1939         }
1940         spin_unlock(&ses->ses_lock);
1941
1942         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1943         cifs_dbg(FYI,
1944                  "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1945
1946         spin_lock(&cifs_tcp_ses_lock);
1947         if (--ses->ses_count > 0) {
1948                 spin_unlock(&cifs_tcp_ses_lock);
1949                 return;
1950         }
1951         spin_unlock(&cifs_tcp_ses_lock);
1952
1953         /* ses_count can never go negative */
1954         WARN_ON(ses->ses_count < 0);
1955
1956         if (ses->ses_status == SES_GOOD)
1957                 ses->ses_status = SES_EXITING;
1958
1959         cifs_free_ipc(ses);
1960
1961         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1962                 xid = get_xid();
1963                 rc = server->ops->logoff(xid, ses);
1964                 if (rc)
1965                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1966                                 __func__, rc);
1967                 _free_xid(xid);
1968         }
1969
1970         spin_lock(&cifs_tcp_ses_lock);
1971         list_del_init(&ses->smb_ses_list);
1972         spin_unlock(&cifs_tcp_ses_lock);
1973
1974         chan_count = ses->chan_count;
1975
1976         /* close any extra channels */
1977         if (chan_count > 1) {
1978                 int i;
1979
1980                 for (i = 1; i < chan_count; i++) {
1981                         if (ses->chans[i].iface) {
1982                                 kref_put(&ses->chans[i].iface->refcount, release_iface);
1983                                 ses->chans[i].iface = NULL;
1984                         }
1985                         cifs_put_tcp_session(ses->chans[i].server, 0);
1986                         ses->chans[i].server = NULL;
1987                 }
1988         }
1989
1990         sesInfoFree(ses);
1991         cifs_put_tcp_session(server, 0);
1992 }
1993
1994 #ifdef CONFIG_KEYS
1995
1996 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1997 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1998
1999 /* Populate username and pw fields from keyring if possible */
2000 static int
2001 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2002 {
2003         int rc = 0;
2004         int is_domain = 0;
2005         const char *delim, *payload;
2006         char *desc;
2007         ssize_t len;
2008         struct key *key;
2009         struct TCP_Server_Info *server = ses->server;
2010         struct sockaddr_in *sa;
2011         struct sockaddr_in6 *sa6;
2012         const struct user_key_payload *upayload;
2013
2014         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2015         if (!desc)
2016                 return -ENOMEM;
2017
2018         /* try to find an address key first */
2019         switch (server->dstaddr.ss_family) {
2020         case AF_INET:
2021                 sa = (struct sockaddr_in *)&server->dstaddr;
2022                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2023                 break;
2024         case AF_INET6:
2025                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2026                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2027                 break;
2028         default:
2029                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2030                          server->dstaddr.ss_family);
2031                 rc = -EINVAL;
2032                 goto out_err;
2033         }
2034
2035         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2036         key = request_key(&key_type_logon, desc, "");
2037         if (IS_ERR(key)) {
2038                 if (!ses->domainName) {
2039                         cifs_dbg(FYI, "domainName is NULL\n");
2040                         rc = PTR_ERR(key);
2041                         goto out_err;
2042                 }
2043
2044                 /* didn't work, try to find a domain key */
2045                 sprintf(desc, "cifs:d:%s", ses->domainName);
2046                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2047                 key = request_key(&key_type_logon, desc, "");
2048                 if (IS_ERR(key)) {
2049                         rc = PTR_ERR(key);
2050                         goto out_err;
2051                 }
2052                 is_domain = 1;
2053         }
2054
2055         down_read(&key->sem);
2056         upayload = user_key_payload_locked(key);
2057         if (IS_ERR_OR_NULL(upayload)) {
2058                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2059                 goto out_key_put;
2060         }
2061
2062         /* find first : in payload */
2063         payload = upayload->data;
2064         delim = strnchr(payload, upayload->datalen, ':');
2065         cifs_dbg(FYI, "payload=%s\n", payload);
2066         if (!delim) {
2067                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2068                          upayload->datalen);
2069                 rc = -EINVAL;
2070                 goto out_key_put;
2071         }
2072
2073         len = delim - payload;
2074         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2075                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2076                          len);
2077                 rc = -EINVAL;
2078                 goto out_key_put;
2079         }
2080
2081         ctx->username = kstrndup(payload, len, GFP_KERNEL);
2082         if (!ctx->username) {
2083                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2084                          len);
2085                 rc = -ENOMEM;
2086                 goto out_key_put;
2087         }
2088         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2089
2090         len = key->datalen - (len + 1);
2091         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2092                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2093                 rc = -EINVAL;
2094                 kfree(ctx->username);
2095                 ctx->username = NULL;
2096                 goto out_key_put;
2097         }
2098
2099         ++delim;
2100         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2101         if (!ctx->password) {
2102                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2103                          len);
2104                 rc = -ENOMEM;
2105                 kfree(ctx->username);
2106                 ctx->username = NULL;
2107                 goto out_key_put;
2108         }
2109
2110         /*
2111          * If we have a domain key then we must set the domainName in the
2112          * for the request.
2113          */
2114         if (is_domain && ses->domainName) {
2115                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2116                 if (!ctx->domainname) {
2117                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2118                                  len);
2119                         rc = -ENOMEM;
2120                         kfree(ctx->username);
2121                         ctx->username = NULL;
2122                         kfree_sensitive(ctx->password);
2123                         ctx->password = NULL;
2124                         goto out_key_put;
2125                 }
2126         }
2127
2128         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2129
2130 out_key_put:
2131         up_read(&key->sem);
2132         key_put(key);
2133 out_err:
2134         kfree(desc);
2135         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2136         return rc;
2137 }
2138 #else /* ! CONFIG_KEYS */
2139 static inline int
2140 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2141                    struct cifs_ses *ses __attribute__((unused)))
2142 {
2143         return -ENOSYS;
2144 }
2145 #endif /* CONFIG_KEYS */
2146
2147 /**
2148  * cifs_get_smb_ses - get a session matching @ctx data from @server
2149  * @server: server to setup the session to
2150  * @ctx: superblock configuration context to use to setup the session
2151  *
2152  * This function assumes it is being called from cifs_mount() where we
2153  * already got a server reference (server refcount +1). See
2154  * cifs_get_tcon() for refcount explanations.
2155  */
2156 struct cifs_ses *
2157 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2158 {
2159         int rc = -ENOMEM;
2160         unsigned int xid;
2161         struct cifs_ses *ses;
2162         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2163         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2164
2165         xid = get_xid();
2166
2167         ses = cifs_find_smb_ses(server, ctx);
2168         if (ses) {
2169                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2170                          ses->ses_status);
2171
2172                 spin_lock(&ses->chan_lock);
2173                 if (cifs_chan_needs_reconnect(ses, server)) {
2174                         spin_unlock(&ses->chan_lock);
2175                         cifs_dbg(FYI, "Session needs reconnect\n");
2176
2177                         mutex_lock(&ses->session_mutex);
2178                         rc = cifs_negotiate_protocol(xid, ses, server);
2179                         if (rc) {
2180                                 mutex_unlock(&ses->session_mutex);
2181                                 /* problem -- put our ses reference */
2182                                 cifs_put_smb_ses(ses);
2183                                 free_xid(xid);
2184                                 return ERR_PTR(rc);
2185                         }
2186
2187                         rc = cifs_setup_session(xid, ses, server,
2188                                                 ctx->local_nls);
2189                         if (rc) {
2190                                 mutex_unlock(&ses->session_mutex);
2191                                 /* problem -- put our reference */
2192                                 cifs_put_smb_ses(ses);
2193                                 free_xid(xid);
2194                                 return ERR_PTR(rc);
2195                         }
2196                         mutex_unlock(&ses->session_mutex);
2197
2198                         spin_lock(&ses->chan_lock);
2199                 }
2200                 spin_unlock(&ses->chan_lock);
2201
2202                 /* existing SMB ses has a server reference already */
2203                 cifs_put_tcp_session(server, 0);
2204                 free_xid(xid);
2205                 return ses;
2206         }
2207
2208         cifs_dbg(FYI, "Existing smb sess not found\n");
2209         ses = sesInfoAlloc();
2210         if (ses == NULL)
2211                 goto get_ses_fail;
2212
2213         /* new SMB session uses our server ref */
2214         ses->server = server;
2215         if (server->dstaddr.ss_family == AF_INET6)
2216                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2217         else
2218                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2219
2220         if (ctx->username) {
2221                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2222                 if (!ses->user_name)
2223                         goto get_ses_fail;
2224         }
2225
2226         /* ctx->password freed at unmount */
2227         if (ctx->password) {
2228                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2229                 if (!ses->password)
2230                         goto get_ses_fail;
2231         }
2232         if (ctx->domainname) {
2233                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2234                 if (!ses->domainName)
2235                         goto get_ses_fail;
2236         }
2237
2238         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2239
2240         if (ctx->domainauto)
2241                 ses->domainAuto = ctx->domainauto;
2242         ses->cred_uid = ctx->cred_uid;
2243         ses->linux_uid = ctx->linux_uid;
2244
2245         ses->sectype = ctx->sectype;
2246         ses->sign = ctx->sign;
2247
2248         /* add server as first channel */
2249         spin_lock(&ses->chan_lock);
2250         ses->chans[0].server = server;
2251         ses->chan_count = 1;
2252         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2253         ses->chans_need_reconnect = 1;
2254         spin_unlock(&ses->chan_lock);
2255
2256         mutex_lock(&ses->session_mutex);
2257         rc = cifs_negotiate_protocol(xid, ses, server);
2258         if (!rc)
2259                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2260         mutex_unlock(&ses->session_mutex);
2261
2262         /* each channel uses a different signing key */
2263         spin_lock(&ses->chan_lock);
2264         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2265                sizeof(ses->smb3signingkey));
2266         spin_unlock(&ses->chan_lock);
2267
2268         if (rc)
2269                 goto get_ses_fail;
2270
2271         /*
2272          * success, put it on the list and add it as first channel
2273          * note: the session becomes active soon after this. So you'll
2274          * need to lock before changing something in the session.
2275          */
2276         spin_lock(&cifs_tcp_ses_lock);
2277         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2278         spin_unlock(&cifs_tcp_ses_lock);
2279
2280         free_xid(xid);
2281
2282         cifs_setup_ipc(ses, ctx);
2283
2284         return ses;
2285
2286 get_ses_fail:
2287         sesInfoFree(ses);
2288         free_xid(xid);
2289         return ERR_PTR(rc);
2290 }
2291
2292 /* this function must be called with tc_lock held */
2293 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2294 {
2295         if (tcon->status == TID_EXITING)
2296                 return 0;
2297         if (strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2298                 return 0;
2299         if (tcon->seal != ctx->seal)
2300                 return 0;
2301         if (tcon->snapshot_time != ctx->snapshot_time)
2302                 return 0;
2303         if (tcon->handle_timeout != ctx->handle_timeout)
2304                 return 0;
2305         if (tcon->no_lease != ctx->no_lease)
2306                 return 0;
2307         if (tcon->nodelete != ctx->nodelete)
2308                 return 0;
2309         return 1;
2310 }
2311
2312 static struct cifs_tcon *
2313 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2314 {
2315         struct cifs_tcon *tcon;
2316
2317         spin_lock(&cifs_tcp_ses_lock);
2318         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2319                 spin_lock(&tcon->tc_lock);
2320                 if (!match_tcon(tcon, ctx)) {
2321                         spin_unlock(&tcon->tc_lock);
2322                         continue;
2323                 }
2324                 ++tcon->tc_count;
2325                 spin_unlock(&tcon->tc_lock);
2326                 spin_unlock(&cifs_tcp_ses_lock);
2327                 return tcon;
2328         }
2329         spin_unlock(&cifs_tcp_ses_lock);
2330         return NULL;
2331 }
2332
2333 void
2334 cifs_put_tcon(struct cifs_tcon *tcon)
2335 {
2336         unsigned int xid;
2337         struct cifs_ses *ses;
2338
2339         /*
2340          * IPC tcon share the lifetime of their session and are
2341          * destroyed in the session put function
2342          */
2343         if (tcon == NULL || tcon->ipc)
2344                 return;
2345
2346         ses = tcon->ses;
2347         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2348         spin_lock(&cifs_tcp_ses_lock);
2349         spin_lock(&tcon->tc_lock);
2350         if (--tcon->tc_count > 0) {
2351                 spin_unlock(&tcon->tc_lock);
2352                 spin_unlock(&cifs_tcp_ses_lock);
2353                 return;
2354         }
2355
2356         /* tc_count can never go negative */
2357         WARN_ON(tcon->tc_count < 0);
2358
2359         list_del_init(&tcon->tcon_list);
2360         spin_unlock(&tcon->tc_lock);
2361         spin_unlock(&cifs_tcp_ses_lock);
2362
2363         /* cancel polling of interfaces */
2364         cancel_delayed_work_sync(&tcon->query_interfaces);
2365
2366         if (tcon->use_witness) {
2367                 int rc;
2368
2369                 rc = cifs_swn_unregister(tcon);
2370                 if (rc < 0) {
2371                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2372                                         __func__, rc);
2373                 }
2374         }
2375
2376         xid = get_xid();
2377         if (ses->server->ops->tree_disconnect)
2378                 ses->server->ops->tree_disconnect(xid, tcon);
2379         _free_xid(xid);
2380
2381         cifs_fscache_release_super_cookie(tcon);
2382         tconInfoFree(tcon);
2383         cifs_put_smb_ses(ses);
2384 }
2385
2386 /**
2387  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2388  * @ses: smb session to issue the request on
2389  * @ctx: the superblock configuration context to use for building the
2390  *
2391  * - tcon refcount is the number of mount points using the tcon.
2392  * - ses refcount is the number of tcon using the session.
2393  *
2394  * 1. This function assumes it is being called from cifs_mount() where
2395  *    we already got a session reference (ses refcount +1).
2396  *
2397  * 2. Since we're in the context of adding a mount point, the end
2398  *    result should be either:
2399  *
2400  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2401  *    its session refcount incremented (1 new tcon). This +1 was
2402  *    already done in (1).
2403  *
2404  * b) an existing tcon with refcount+1 (add a mount point to it) and
2405  *    identical ses refcount (no new tcon). Because of (1) we need to
2406  *    decrement the ses refcount.
2407  */
2408 static struct cifs_tcon *
2409 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2410 {
2411         int rc, xid;
2412         struct cifs_tcon *tcon;
2413
2414         tcon = cifs_find_tcon(ses, ctx);
2415         if (tcon) {
2416                 /*
2417                  * tcon has refcount already incremented but we need to
2418                  * decrement extra ses reference gotten by caller (case b)
2419                  */
2420                 cifs_dbg(FYI, "Found match on UNC path\n");
2421                 cifs_put_smb_ses(ses);
2422                 return tcon;
2423         }
2424
2425         if (!ses->server->ops->tree_connect) {
2426                 rc = -ENOSYS;
2427                 goto out_fail;
2428         }
2429
2430         tcon = tconInfoAlloc();
2431         if (tcon == NULL) {
2432                 rc = -ENOMEM;
2433                 goto out_fail;
2434         }
2435
2436         if (ctx->snapshot_time) {
2437                 if (ses->server->vals->protocol_id == 0) {
2438                         cifs_dbg(VFS,
2439                              "Use SMB2 or later for snapshot mount option\n");
2440                         rc = -EOPNOTSUPP;
2441                         goto out_fail;
2442                 } else
2443                         tcon->snapshot_time = ctx->snapshot_time;
2444         }
2445
2446         if (ctx->handle_timeout) {
2447                 if (ses->server->vals->protocol_id == 0) {
2448                         cifs_dbg(VFS,
2449                              "Use SMB2.1 or later for handle timeout option\n");
2450                         rc = -EOPNOTSUPP;
2451                         goto out_fail;
2452                 } else
2453                         tcon->handle_timeout = ctx->handle_timeout;
2454         }
2455
2456         tcon->ses = ses;
2457         if (ctx->password) {
2458                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2459                 if (!tcon->password) {
2460                         rc = -ENOMEM;
2461                         goto out_fail;
2462                 }
2463         }
2464
2465         if (ctx->seal) {
2466                 if (ses->server->vals->protocol_id == 0) {
2467                         cifs_dbg(VFS,
2468                                  "SMB3 or later required for encryption\n");
2469                         rc = -EOPNOTSUPP;
2470                         goto out_fail;
2471                 } else if (tcon->ses->server->capabilities &
2472                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2473                         tcon->seal = true;
2474                 else {
2475                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2476                         rc = -EOPNOTSUPP;
2477                         goto out_fail;
2478                 }
2479         }
2480
2481         if (ctx->linux_ext) {
2482                 if (ses->server->posix_ext_supported) {
2483                         tcon->posix_extensions = true;
2484                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2485                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2486                     (strcmp(ses->server->vals->version_string,
2487                      SMB3ANY_VERSION_STRING) == 0) ||
2488                     (strcmp(ses->server->vals->version_string,
2489                      SMBDEFAULT_VERSION_STRING) == 0)) {
2490                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2491                         rc = -EOPNOTSUPP;
2492                         goto out_fail;
2493                 } else {
2494                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2495                                 "disabled but required for POSIX extensions\n");
2496                         rc = -EOPNOTSUPP;
2497                         goto out_fail;
2498                 }
2499         }
2500
2501         xid = get_xid();
2502         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2503                                             ctx->local_nls);
2504         free_xid(xid);
2505         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2506         if (rc)
2507                 goto out_fail;
2508
2509         tcon->use_persistent = false;
2510         /* check if SMB2 or later, CIFS does not support persistent handles */
2511         if (ctx->persistent) {
2512                 if (ses->server->vals->protocol_id == 0) {
2513                         cifs_dbg(VFS,
2514                              "SMB3 or later required for persistent handles\n");
2515                         rc = -EOPNOTSUPP;
2516                         goto out_fail;
2517                 } else if (ses->server->capabilities &
2518                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2519                         tcon->use_persistent = true;
2520                 else /* persistent handles requested but not supported */ {
2521                         cifs_dbg(VFS,
2522                                 "Persistent handles not supported on share\n");
2523                         rc = -EOPNOTSUPP;
2524                         goto out_fail;
2525                 }
2526         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2527              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2528              && (ctx->nopersistent == false)) {
2529                 cifs_dbg(FYI, "enabling persistent handles\n");
2530                 tcon->use_persistent = true;
2531         } else if (ctx->resilient) {
2532                 if (ses->server->vals->protocol_id == 0) {
2533                         cifs_dbg(VFS,
2534                              "SMB2.1 or later required for resilient handles\n");
2535                         rc = -EOPNOTSUPP;
2536                         goto out_fail;
2537                 }
2538                 tcon->use_resilient = true;
2539         }
2540
2541         tcon->use_witness = false;
2542         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2543                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2544                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2545                                 /*
2546                                  * Set witness in use flag in first place
2547                                  * to retry registration in the echo task
2548                                  */
2549                                 tcon->use_witness = true;
2550                                 /* And try to register immediately */
2551                                 rc = cifs_swn_register(tcon);
2552                                 if (rc < 0) {
2553                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2554                                         goto out_fail;
2555                                 }
2556                         } else {
2557                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2558                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2559                                 rc = -EOPNOTSUPP;
2560                                 goto out_fail;
2561                         }
2562                 } else {
2563                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2564                         rc = -EOPNOTSUPP;
2565                         goto out_fail;
2566                 }
2567         }
2568
2569         /* If the user really knows what they are doing they can override */
2570         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2571                 if (ctx->cache_ro)
2572                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2573                 else if (ctx->cache_rw)
2574                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2575         }
2576
2577         if (ctx->no_lease) {
2578                 if (ses->server->vals->protocol_id == 0) {
2579                         cifs_dbg(VFS,
2580                                 "SMB2 or later required for nolease option\n");
2581                         rc = -EOPNOTSUPP;
2582                         goto out_fail;
2583                 } else
2584                         tcon->no_lease = ctx->no_lease;
2585         }
2586
2587         /*
2588          * We can have only one retry value for a connection to a share so for
2589          * resources mounted more than once to the same server share the last
2590          * value passed in for the retry flag is used.
2591          */
2592         tcon->retry = ctx->retry;
2593         tcon->nocase = ctx->nocase;
2594         tcon->broken_sparse_sup = ctx->no_sparse;
2595         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2596                 tcon->nohandlecache = ctx->nohandlecache;
2597         else
2598                 tcon->nohandlecache = true;
2599         tcon->nodelete = ctx->nodelete;
2600         tcon->local_lease = ctx->local_lease;
2601         INIT_LIST_HEAD(&tcon->pending_opens);
2602
2603         /* schedule query interfaces poll */
2604         INIT_DELAYED_WORK(&tcon->query_interfaces,
2605                           smb2_query_server_interfaces);
2606         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2607                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
2608
2609         spin_lock(&cifs_tcp_ses_lock);
2610         list_add(&tcon->tcon_list, &ses->tcon_list);
2611         spin_unlock(&cifs_tcp_ses_lock);
2612
2613         return tcon;
2614
2615 out_fail:
2616         tconInfoFree(tcon);
2617         return ERR_PTR(rc);
2618 }
2619
2620 void
2621 cifs_put_tlink(struct tcon_link *tlink)
2622 {
2623         if (!tlink || IS_ERR(tlink))
2624                 return;
2625
2626         if (!atomic_dec_and_test(&tlink->tl_count) ||
2627             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2628                 tlink->tl_time = jiffies;
2629                 return;
2630         }
2631
2632         if (!IS_ERR(tlink_tcon(tlink)))
2633                 cifs_put_tcon(tlink_tcon(tlink));
2634         kfree(tlink);
2635         return;
2636 }
2637
2638 static int
2639 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2640 {
2641         struct cifs_sb_info *old = CIFS_SB(sb);
2642         struct cifs_sb_info *new = mnt_data->cifs_sb;
2643         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2644         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2645
2646         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2647                 return 0;
2648
2649         if (old->mnt_cifs_serverino_autodisabled)
2650                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2651
2652         if (oldflags != newflags)
2653                 return 0;
2654
2655         /*
2656          * We want to share sb only if we don't specify an r/wsize or
2657          * specified r/wsize is greater than or equal to existing one.
2658          */
2659         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2660                 return 0;
2661
2662         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2663                 return 0;
2664
2665         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2666             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2667                 return 0;
2668
2669         if (old->ctx->file_mode != new->ctx->file_mode ||
2670             old->ctx->dir_mode != new->ctx->dir_mode)
2671                 return 0;
2672
2673         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2674                 return 0;
2675
2676         if (old->ctx->acregmax != new->ctx->acregmax)
2677                 return 0;
2678         if (old->ctx->acdirmax != new->ctx->acdirmax)
2679                 return 0;
2680         if (old->ctx->closetimeo != new->ctx->closetimeo)
2681                 return 0;
2682
2683         return 1;
2684 }
2685
2686 static int
2687 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2688 {
2689         struct cifs_sb_info *old = CIFS_SB(sb);
2690         struct cifs_sb_info *new = mnt_data->cifs_sb;
2691         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2692                 old->prepath;
2693         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2694                 new->prepath;
2695
2696         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2697                 return 1;
2698         else if (!old_set && !new_set)
2699                 return 1;
2700
2701         return 0;
2702 }
2703
2704 int
2705 cifs_match_super(struct super_block *sb, void *data)
2706 {
2707         struct cifs_mnt_data *mnt_data = data;
2708         struct smb3_fs_context *ctx;
2709         struct cifs_sb_info *cifs_sb;
2710         struct TCP_Server_Info *tcp_srv;
2711         struct cifs_ses *ses;
2712         struct cifs_tcon *tcon;
2713         struct tcon_link *tlink;
2714         int rc = 0;
2715
2716         spin_lock(&cifs_tcp_ses_lock);
2717         cifs_sb = CIFS_SB(sb);
2718         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2719         if (tlink == NULL) {
2720                 /* can not match superblock if tlink were ever null */
2721                 spin_unlock(&cifs_tcp_ses_lock);
2722                 return 0;
2723         }
2724         tcon = tlink_tcon(tlink);
2725         ses = tcon->ses;
2726         tcp_srv = ses->server;
2727
2728         ctx = mnt_data->ctx;
2729
2730         spin_lock(&tcp_srv->srv_lock);
2731         spin_lock(&ses->ses_lock);
2732         spin_lock(&tcon->tc_lock);
2733         if (!match_server(tcp_srv, ctx) ||
2734             !match_session(ses, ctx) ||
2735             !match_tcon(tcon, ctx) ||
2736             !match_prepath(sb, mnt_data)) {
2737                 rc = 0;
2738                 goto out;
2739         }
2740
2741         rc = compare_mount_options(sb, mnt_data);
2742 out:
2743         spin_unlock(&tcon->tc_lock);
2744         spin_unlock(&ses->ses_lock);
2745         spin_unlock(&tcp_srv->srv_lock);
2746
2747         spin_unlock(&cifs_tcp_ses_lock);
2748         cifs_put_tlink(tlink);
2749         return rc;
2750 }
2751
2752 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2753 static struct lock_class_key cifs_key[2];
2754 static struct lock_class_key cifs_slock_key[2];
2755
2756 static inline void
2757 cifs_reclassify_socket4(struct socket *sock)
2758 {
2759         struct sock *sk = sock->sk;
2760         BUG_ON(!sock_allow_reclassification(sk));
2761         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2762                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2763 }
2764
2765 static inline void
2766 cifs_reclassify_socket6(struct socket *sock)
2767 {
2768         struct sock *sk = sock->sk;
2769         BUG_ON(!sock_allow_reclassification(sk));
2770         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2771                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2772 }
2773 #else
2774 static inline void
2775 cifs_reclassify_socket4(struct socket *sock)
2776 {
2777 }
2778
2779 static inline void
2780 cifs_reclassify_socket6(struct socket *sock)
2781 {
2782 }
2783 #endif
2784
2785 /* See RFC1001 section 14 on representation of Netbios names */
2786 static void rfc1002mangle(char *target, char *source, unsigned int length)
2787 {
2788         unsigned int i, j;
2789
2790         for (i = 0, j = 0; i < (length); i++) {
2791                 /* mask a nibble at a time and encode */
2792                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2793                 target[j+1] = 'A' + (0x0F & source[i]);
2794                 j += 2;
2795         }
2796
2797 }
2798
2799 static int
2800 bind_socket(struct TCP_Server_Info *server)
2801 {
2802         int rc = 0;
2803         if (server->srcaddr.ss_family != AF_UNSPEC) {
2804                 /* Bind to the specified local IP address */
2805                 struct socket *socket = server->ssocket;
2806                 rc = socket->ops->bind(socket,
2807                                        (struct sockaddr *) &server->srcaddr,
2808                                        sizeof(server->srcaddr));
2809                 if (rc < 0) {
2810                         struct sockaddr_in *saddr4;
2811                         struct sockaddr_in6 *saddr6;
2812                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2813                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2814                         if (saddr6->sin6_family == AF_INET6)
2815                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2816                                          &saddr6->sin6_addr, rc);
2817                         else
2818                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2819                                          &saddr4->sin_addr.s_addr, rc);
2820                 }
2821         }
2822         return rc;
2823 }
2824
2825 static int
2826 ip_rfc1001_connect(struct TCP_Server_Info *server)
2827 {
2828         int rc = 0;
2829         /*
2830          * some servers require RFC1001 sessinit before sending
2831          * negprot - BB check reconnection in case where second
2832          * sessinit is sent but no second negprot
2833          */
2834         struct rfc1002_session_packet *ses_init_buf;
2835         unsigned int req_noscope_len;
2836         struct smb_hdr *smb_buf;
2837
2838         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2839                                GFP_KERNEL);
2840
2841         if (ses_init_buf) {
2842                 ses_init_buf->trailer.session_req.called_len = 32;
2843
2844                 if (server->server_RFC1001_name[0] != 0)
2845                         rfc1002mangle(ses_init_buf->trailer.
2846                                       session_req.called_name,
2847                                       server->server_RFC1001_name,
2848                                       RFC1001_NAME_LEN_WITH_NULL);
2849                 else
2850                         rfc1002mangle(ses_init_buf->trailer.
2851                                       session_req.called_name,
2852                                       DEFAULT_CIFS_CALLED_NAME,
2853                                       RFC1001_NAME_LEN_WITH_NULL);
2854
2855                 ses_init_buf->trailer.session_req.calling_len = 32;
2856
2857                 /*
2858                  * calling name ends in null (byte 16) from old smb
2859                  * convention.
2860                  */
2861                 if (server->workstation_RFC1001_name[0] != 0)
2862                         rfc1002mangle(ses_init_buf->trailer.
2863                                       session_req.calling_name,
2864                                       server->workstation_RFC1001_name,
2865                                       RFC1001_NAME_LEN_WITH_NULL);
2866                 else
2867                         rfc1002mangle(ses_init_buf->trailer.
2868                                       session_req.calling_name,
2869                                       "LINUX_CIFS_CLNT",
2870                                       RFC1001_NAME_LEN_WITH_NULL);
2871
2872                 ses_init_buf->trailer.session_req.scope1 = 0;
2873                 ses_init_buf->trailer.session_req.scope2 = 0;
2874                 smb_buf = (struct smb_hdr *)ses_init_buf;
2875
2876                 /* sizeof RFC1002_SESSION_REQUEST with no scopes */
2877                 req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
2878
2879                 /* == cpu_to_be32(0x81000044) */
2880                 smb_buf->smb_buf_length =
2881                         cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
2882                 rc = smb_send(server, smb_buf, 0x44);
2883                 kfree(ses_init_buf);
2884                 /*
2885                  * RFC1001 layer in at least one server
2886                  * requires very short break before negprot
2887                  * presumably because not expecting negprot
2888                  * to follow so fast.  This is a simple
2889                  * solution that works without
2890                  * complicating the code and causes no
2891                  * significant slowing down on mount
2892                  * for everyone else
2893                  */
2894                 usleep_range(1000, 2000);
2895         }
2896         /*
2897          * else the negprot may still work without this
2898          * even though malloc failed
2899          */
2900
2901         return rc;
2902 }
2903
2904 static int
2905 generic_ip_connect(struct TCP_Server_Info *server)
2906 {
2907         int rc = 0;
2908         __be16 sport;
2909         int slen, sfamily;
2910         struct socket *socket = server->ssocket;
2911         struct sockaddr *saddr;
2912
2913         saddr = (struct sockaddr *) &server->dstaddr;
2914
2915         if (server->dstaddr.ss_family == AF_INET6) {
2916                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2917
2918                 sport = ipv6->sin6_port;
2919                 slen = sizeof(struct sockaddr_in6);
2920                 sfamily = AF_INET6;
2921                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2922                                 ntohs(sport));
2923         } else {
2924                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2925
2926                 sport = ipv4->sin_port;
2927                 slen = sizeof(struct sockaddr_in);
2928                 sfamily = AF_INET;
2929                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2930                                 ntohs(sport));
2931         }
2932
2933         if (socket == NULL) {
2934                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2935                                    IPPROTO_TCP, &socket, 1);
2936                 if (rc < 0) {
2937                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2938                         server->ssocket = NULL;
2939                         return rc;
2940                 }
2941
2942                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2943                 cifs_dbg(FYI, "Socket created\n");
2944                 server->ssocket = socket;
2945                 socket->sk->sk_allocation = GFP_NOFS;
2946                 if (sfamily == AF_INET6)
2947                         cifs_reclassify_socket6(socket);
2948                 else
2949                         cifs_reclassify_socket4(socket);
2950         }
2951
2952         rc = bind_socket(server);
2953         if (rc < 0)
2954                 return rc;
2955
2956         /*
2957          * Eventually check for other socket options to change from
2958          * the default. sock_setsockopt not used because it expects
2959          * user space buffer
2960          */
2961         socket->sk->sk_rcvtimeo = 7 * HZ;
2962         socket->sk->sk_sndtimeo = 5 * HZ;
2963
2964         /* make the bufsizes depend on wsize/rsize and max requests */
2965         if (server->noautotune) {
2966                 if (socket->sk->sk_sndbuf < (200 * 1024))
2967                         socket->sk->sk_sndbuf = 200 * 1024;
2968                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2969                         socket->sk->sk_rcvbuf = 140 * 1024;
2970         }
2971
2972         if (server->tcp_nodelay)
2973                 tcp_sock_set_nodelay(socket->sk);
2974
2975         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2976                  socket->sk->sk_sndbuf,
2977                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2978
2979         rc = socket->ops->connect(socket, saddr, slen,
2980                                   server->noblockcnt ? O_NONBLOCK : 0);
2981         /*
2982          * When mounting SMB root file systems, we do not want to block in
2983          * connect. Otherwise bail out and then let cifs_reconnect() perform
2984          * reconnect failover - if possible.
2985          */
2986         if (server->noblockcnt && rc == -EINPROGRESS)
2987                 rc = 0;
2988         if (rc < 0) {
2989                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2990                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2991                 sock_release(socket);
2992                 server->ssocket = NULL;
2993                 return rc;
2994         }
2995         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2996         if (sport == htons(RFC1001_PORT))
2997                 rc = ip_rfc1001_connect(server);
2998
2999         return rc;
3000 }
3001
3002 static int
3003 ip_connect(struct TCP_Server_Info *server)
3004 {
3005         __be16 *sport;
3006         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3007         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3008
3009         if (server->dstaddr.ss_family == AF_INET6)
3010                 sport = &addr6->sin6_port;
3011         else
3012                 sport = &addr->sin_port;
3013
3014         if (*sport == 0) {
3015                 int rc;
3016
3017                 /* try with 445 port at first */
3018                 *sport = htons(CIFS_PORT);
3019
3020                 rc = generic_ip_connect(server);
3021                 if (rc >= 0)
3022                         return rc;
3023
3024                 /* if it failed, try with 139 port */
3025                 *sport = htons(RFC1001_PORT);
3026         }
3027
3028         return generic_ip_connect(server);
3029 }
3030
3031 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3032 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3033                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3034 {
3035         /*
3036          * If we are reconnecting then should we check to see if
3037          * any requested capabilities changed locally e.g. via
3038          * remount but we can not do much about it here
3039          * if they have (even if we could detect it by the following)
3040          * Perhaps we could add a backpointer to array of sb from tcon
3041          * or if we change to make all sb to same share the same
3042          * sb as NFS - then we only have one backpointer to sb.
3043          * What if we wanted to mount the server share twice once with
3044          * and once without posixacls or posix paths?
3045          */
3046         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3047
3048         if (ctx && ctx->no_linux_ext) {
3049                 tcon->fsUnixInfo.Capability = 0;
3050                 tcon->unix_ext = 0; /* Unix Extensions disabled */
3051                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3052                 return;
3053         } else if (ctx)
3054                 tcon->unix_ext = 1; /* Unix Extensions supported */
3055
3056         if (!tcon->unix_ext) {
3057                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3058                 return;
3059         }
3060
3061         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3062                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3063                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3064                 /*
3065                  * check for reconnect case in which we do not
3066                  * want to change the mount behavior if we can avoid it
3067                  */
3068                 if (ctx == NULL) {
3069                         /*
3070                          * turn off POSIX ACL and PATHNAMES if not set
3071                          * originally at mount time
3072                          */
3073                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3074                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3075                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3076                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3077                                         cifs_dbg(VFS, "POSIXPATH support change\n");
3078                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3079                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3080                                 cifs_dbg(VFS, "possible reconnect error\n");
3081                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
3082                         }
3083                 }
3084
3085                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3086                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
3087
3088                 cap &= CIFS_UNIX_CAP_MASK;
3089                 if (ctx && ctx->no_psx_acl)
3090                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3091                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3092                         cifs_dbg(FYI, "negotiated posix acl support\n");
3093                         if (cifs_sb)
3094                                 cifs_sb->mnt_cifs_flags |=
3095                                         CIFS_MOUNT_POSIXACL;
3096                 }
3097
3098                 if (ctx && ctx->posix_paths == 0)
3099                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3100                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3101                         cifs_dbg(FYI, "negotiate posix pathnames\n");
3102                         if (cifs_sb)
3103                                 cifs_sb->mnt_cifs_flags |=
3104                                         CIFS_MOUNT_POSIX_PATHS;
3105                 }
3106
3107                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3108 #ifdef CONFIG_CIFS_DEBUG2
3109                 if (cap & CIFS_UNIX_FCNTL_CAP)
3110                         cifs_dbg(FYI, "FCNTL cap\n");
3111                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3112                         cifs_dbg(FYI, "EXTATTR cap\n");
3113                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3114                         cifs_dbg(FYI, "POSIX path cap\n");
3115                 if (cap & CIFS_UNIX_XATTR_CAP)
3116                         cifs_dbg(FYI, "XATTR cap\n");
3117                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3118                         cifs_dbg(FYI, "POSIX ACL cap\n");
3119                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3120                         cifs_dbg(FYI, "very large read cap\n");
3121                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3122                         cifs_dbg(FYI, "very large write cap\n");
3123                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3124                         cifs_dbg(FYI, "transport encryption cap\n");
3125                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3126                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3127 #endif /* CIFS_DEBUG2 */
3128                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3129                         if (ctx == NULL)
3130                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3131                         else
3132                                 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");
3133
3134                 }
3135         }
3136 }
3137 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3138
3139 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3140 {
3141         struct smb3_fs_context *ctx = cifs_sb->ctx;
3142
3143         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3144
3145         spin_lock_init(&cifs_sb->tlink_tree_lock);
3146         cifs_sb->tlink_tree = RB_ROOT;
3147
3148         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3149                  ctx->file_mode, ctx->dir_mode);
3150
3151         /* this is needed for ASCII cp to Unicode converts */
3152         if (ctx->iocharset == NULL) {
3153                 /* load_nls_default cannot return null */
3154                 cifs_sb->local_nls = load_nls_default();
3155         } else {
3156                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3157                 if (cifs_sb->local_nls == NULL) {
3158                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3159                                  ctx->iocharset);
3160                         return -ELIBACC;
3161                 }
3162         }
3163         ctx->local_nls = cifs_sb->local_nls;
3164
3165         smb3_update_mnt_flags(cifs_sb);
3166
3167         if (ctx->direct_io)
3168                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3169         if (ctx->cache_ro) {
3170                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3171                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3172         } else if (ctx->cache_rw) {
3173                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3174                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3175                                             CIFS_MOUNT_RW_CACHE);
3176         }
3177
3178         if ((ctx->cifs_acl) && (ctx->dynperm))
3179                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3180
3181         if (ctx->prepath) {
3182                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3183                 if (cifs_sb->prepath == NULL)
3184                         return -ENOMEM;
3185                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3186         }
3187
3188         return 0;
3189 }
3190
3191 /* Release all succeed connections */
3192 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
3193 {
3194         int rc = 0;
3195
3196         if (mnt_ctx->tcon)
3197                 cifs_put_tcon(mnt_ctx->tcon);
3198         else if (mnt_ctx->ses)
3199                 cifs_put_smb_ses(mnt_ctx->ses);
3200         else if (mnt_ctx->server)
3201                 cifs_put_tcp_session(mnt_ctx->server, 0);
3202         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3203         free_xid(mnt_ctx->xid);
3204 }
3205
3206 /* Get connections for tcp, ses and tcon */
3207 static int mount_get_conns(struct mount_ctx *mnt_ctx)
3208 {
3209         int rc = 0;
3210         struct TCP_Server_Info *server = NULL;
3211         struct cifs_ses *ses = NULL;
3212         struct cifs_tcon *tcon = NULL;
3213         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3214         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3215         unsigned int xid;
3216
3217         xid = get_xid();
3218
3219         /* get a reference to a tcp session */
3220         server = cifs_get_tcp_session(ctx, NULL);
3221         if (IS_ERR(server)) {
3222                 rc = PTR_ERR(server);
3223                 server = NULL;
3224                 goto out;
3225         }
3226
3227         /* get a reference to a SMB session */
3228         ses = cifs_get_smb_ses(server, ctx);
3229         if (IS_ERR(ses)) {
3230                 rc = PTR_ERR(ses);
3231                 ses = NULL;
3232                 goto out;
3233         }
3234
3235         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3236                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3237                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3238                 rc = -EOPNOTSUPP;
3239                 goto out;
3240         }
3241
3242         /* search for existing tcon to this server share */
3243         tcon = cifs_get_tcon(ses, ctx);
3244         if (IS_ERR(tcon)) {
3245                 rc = PTR_ERR(tcon);
3246                 tcon = NULL;
3247                 goto out;
3248         }
3249
3250         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3251         if (tcon->posix_extensions)
3252                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3253
3254 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3255         /* tell server which Unix caps we support */
3256         if (cap_unix(tcon->ses)) {
3257                 /*
3258                  * reset of caps checks mount to see if unix extensions disabled
3259                  * for just this mount.
3260                  */
3261                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3262                 spin_lock(&tcon->ses->server->srv_lock);
3263                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3264                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3265                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3266                         spin_unlock(&tcon->ses->server->srv_lock);
3267                         rc = -EACCES;
3268                         goto out;
3269                 }
3270                 spin_unlock(&tcon->ses->server->srv_lock);
3271         } else
3272 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3273                 tcon->unix_ext = 0; /* server does not support them */
3274
3275         /* do not care if a following call succeed - informational */
3276         if (!tcon->pipe && server->ops->qfs_tcon) {
3277                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3278                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3279                         if (tcon->fsDevInfo.DeviceCharacteristics &
3280                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3281                                 cifs_dbg(VFS, "mounted to read only share\n");
3282                         else if ((cifs_sb->mnt_cifs_flags &
3283                                   CIFS_MOUNT_RW_CACHE) == 0)
3284                                 cifs_dbg(VFS, "read only mount of RW share\n");
3285                         /* no need to log a RW mount of a typical RW share */
3286                 }
3287         }
3288
3289         /*
3290          * Clamp the rsize/wsize mount arguments if they are too big for the server
3291          * and set the rsize/wsize to the negotiated values if not passed in by
3292          * the user on mount
3293          */
3294         if ((cifs_sb->ctx->wsize == 0) ||
3295             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3296                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3297         if ((cifs_sb->ctx->rsize == 0) ||
3298             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3299                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3300
3301         /*
3302          * The cookie is initialized from volume info returned above.
3303          * Inside cifs_fscache_get_super_cookie it checks
3304          * that we do not get super cookie twice.
3305          */
3306         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3307                 cifs_fscache_get_super_cookie(tcon);
3308
3309 out:
3310         mnt_ctx->server = server;
3311         mnt_ctx->ses = ses;
3312         mnt_ctx->tcon = tcon;
3313         mnt_ctx->xid = xid;
3314
3315         return rc;
3316 }
3317
3318 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3319                              struct cifs_tcon *tcon)
3320 {
3321         struct tcon_link *tlink;
3322
3323         /* hang the tcon off of the superblock */
3324         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3325         if (tlink == NULL)
3326                 return -ENOMEM;
3327
3328         tlink->tl_uid = ses->linux_uid;
3329         tlink->tl_tcon = tcon;
3330         tlink->tl_time = jiffies;
3331         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3332         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3333
3334         cifs_sb->master_tlink = tlink;
3335         spin_lock(&cifs_sb->tlink_tree_lock);
3336         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3337         spin_unlock(&cifs_sb->tlink_tree_lock);
3338
3339         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3340                                 TLINK_IDLE_EXPIRE);
3341         return 0;
3342 }
3343
3344 #ifdef CONFIG_CIFS_DFS_UPCALL
3345 /* Get unique dfs connections */
3346 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3347 {
3348         int rc;
3349
3350         mnt_ctx->fs_ctx->nosharesock = true;
3351         rc = mount_get_conns(mnt_ctx);
3352         if (mnt_ctx->server) {
3353                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3354                 spin_lock(&mnt_ctx->server->srv_lock);
3355                 mnt_ctx->server->is_dfs_conn = true;
3356                 spin_unlock(&mnt_ctx->server->srv_lock);
3357         }
3358         return rc;
3359 }
3360
3361 /*
3362  * cifs_build_path_to_root returns full path to root when we do not have an
3363  * existing connection (tcon)
3364  */
3365 static char *
3366 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3367                        const struct cifs_sb_info *cifs_sb, bool useppath)
3368 {
3369         char *full_path, *pos;
3370         unsigned int pplen = useppath && ctx->prepath ?
3371                 strlen(ctx->prepath) + 1 : 0;
3372         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3373
3374         if (unc_len > MAX_TREE_SIZE)
3375                 return ERR_PTR(-EINVAL);
3376
3377         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3378         if (full_path == NULL)
3379                 return ERR_PTR(-ENOMEM);
3380
3381         memcpy(full_path, ctx->UNC, unc_len);
3382         pos = full_path + unc_len;
3383
3384         if (pplen) {
3385                 *pos = CIFS_DIR_SEP(cifs_sb);
3386                 memcpy(pos + 1, ctx->prepath, pplen);
3387                 pos += pplen;
3388         }
3389
3390         *pos = '\0'; /* add trailing null */
3391         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3392         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3393         return full_path;
3394 }
3395
3396 /*
3397  * expand_dfs_referral - Update cifs_sb from dfs referral path
3398  *
3399  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3400  * submount.  Otherwise it will be left untouched.
3401  */
3402 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3403                                struct dfs_info3_param *referral)
3404 {
3405         int rc;
3406         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3407         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3408         char *fake_devname = NULL, *mdata = NULL;
3409
3410         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3411                                            &fake_devname);
3412         if (IS_ERR(mdata)) {
3413                 rc = PTR_ERR(mdata);
3414                 mdata = NULL;
3415         } else {
3416                 /*
3417                  * We can not clear out the whole structure since we no longer have an explicit
3418                  * function to parse a mount-string. Instead we need to clear out the individual
3419                  * fields that are no longer valid.
3420                  */
3421                 kfree(ctx->prepath);
3422                 ctx->prepath = NULL;
3423                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3424         }
3425         kfree(fake_devname);
3426         kfree(cifs_sb->ctx->mount_options);
3427         cifs_sb->ctx->mount_options = mdata;
3428
3429         return rc;
3430 }
3431 #endif
3432
3433 /* TODO: all callers to this are broken. We are not parsing mount_options here
3434  * we should pass a clone of the original context?
3435  */
3436 int
3437 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3438 {
3439         int rc;
3440
3441         if (devname) {
3442                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3443                 rc = smb3_parse_devname(devname, ctx);
3444                 if (rc) {
3445                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3446                         return rc;
3447                 }
3448         }
3449
3450         if (mntopts) {
3451                 char *ip;
3452
3453                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3454                 if (rc) {
3455                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3456                         return rc;
3457                 }
3458
3459                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3460                 kfree(ip);
3461                 if (!rc) {
3462                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3463                         return -EINVAL;
3464                 }
3465         }
3466
3467         if (ctx->nullauth) {
3468                 cifs_dbg(FYI, "Anonymous login\n");
3469                 kfree(ctx->username);
3470                 ctx->username = NULL;
3471         } else if (ctx->username) {
3472                 /* BB fixme parse for domain name here */
3473                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3474         } else {
3475                 cifs_dbg(VFS, "No username specified\n");
3476         /* In userspace mount helper we can get user name from alternate
3477            locations such as env variables and files on disk */
3478                 return -EINVAL;
3479         }
3480
3481         return 0;
3482 }
3483
3484 static int
3485 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3486                                         unsigned int xid,
3487                                         struct cifs_tcon *tcon,
3488                                         struct cifs_sb_info *cifs_sb,
3489                                         char *full_path,
3490                                         int added_treename)
3491 {
3492         int rc;
3493         char *s;
3494         char sep, tmp;
3495         int skip = added_treename ? 1 : 0;
3496
3497         sep = CIFS_DIR_SEP(cifs_sb);
3498         s = full_path;
3499
3500         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3501         while (rc == 0) {
3502                 /* skip separators */
3503                 while (*s == sep)
3504                         s++;
3505                 if (!*s)
3506                         break;
3507                 /* next separator */
3508                 while (*s && *s != sep)
3509                         s++;
3510                 /*
3511                  * if the treename is added, we then have to skip the first
3512                  * part within the separators
3513                  */
3514                 if (skip) {
3515                         skip = 0;
3516                         continue;
3517                 }
3518                 /*
3519                  * temporarily null-terminate the path at the end of
3520                  * the current component
3521                  */
3522                 tmp = *s;
3523                 *s = 0;
3524                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3525                                                      full_path);
3526                 *s = tmp;
3527         }
3528         return rc;
3529 }
3530
3531 /*
3532  * Check if path is remote (i.e. a DFS share).
3533  *
3534  * Return -EREMOTE if it is, otherwise 0 or -errno.
3535  */
3536 static int is_path_remote(struct mount_ctx *mnt_ctx)
3537 {
3538         int rc;
3539         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3540         struct TCP_Server_Info *server = mnt_ctx->server;
3541         unsigned int xid = mnt_ctx->xid;
3542         struct cifs_tcon *tcon = mnt_ctx->tcon;
3543         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3544         char *full_path;
3545 #ifdef CONFIG_CIFS_DFS_UPCALL
3546         bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
3547 #endif
3548
3549         if (!server->ops->is_path_accessible)
3550                 return -EOPNOTSUPP;
3551
3552         /*
3553          * cifs_build_path_to_root works only when we have a valid tcon
3554          */
3555         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3556                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3557         if (full_path == NULL)
3558                 return -ENOMEM;
3559
3560         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3561
3562         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3563                                              full_path);
3564 #ifdef CONFIG_CIFS_DFS_UPCALL
3565         if (nodfs) {
3566                 if (rc == -EREMOTE)
3567                         rc = -EOPNOTSUPP;
3568                 goto out;
3569         }
3570
3571         /* path *might* exist with non-ASCII characters in DFS root
3572          * try again with full path (only if nodfs is not set) */
3573         if (rc == -ENOENT && is_tcon_dfs(tcon))
3574                 rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
3575                                                         full_path);
3576 #endif
3577         if (rc != 0 && rc != -EREMOTE)
3578                 goto out;
3579
3580         if (rc != -EREMOTE) {
3581                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3582                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3583                 if (rc != 0) {
3584                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3585                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3586                         rc = 0;
3587                 }
3588         }
3589
3590 out:
3591         kfree(full_path);
3592         return rc;
3593 }
3594
3595 #ifdef CONFIG_CIFS_DFS_UPCALL
3596 static void set_root_ses(struct mount_ctx *mnt_ctx)
3597 {
3598         if (mnt_ctx->ses) {
3599                 spin_lock(&cifs_tcp_ses_lock);
3600                 mnt_ctx->ses->ses_count++;
3601                 spin_unlock(&cifs_tcp_ses_lock);
3602                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3603         }
3604         mnt_ctx->root_ses = mnt_ctx->ses;
3605 }
3606
3607 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3608 {
3609         int rc;
3610         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3611         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3612
3613         *isdfs = true;
3614
3615         rc = mount_get_conns(mnt_ctx);
3616         /*
3617          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3618          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3619          *
3620          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3621          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3622          */
3623         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3624             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3625                            ctx->UNC + 1, NULL, root_tl)) {
3626                 if (rc)
3627                         return rc;
3628                 /* Check if it is fully accessible and then mount it */
3629                 rc = is_path_remote(mnt_ctx);
3630                 if (!rc)
3631                         *isdfs = false;
3632                 else if (rc != -EREMOTE)
3633                         return rc;
3634         }
3635         return 0;
3636 }
3637
3638 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3639                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3640 {
3641         int rc;
3642         struct dfs_info3_param ref = {};
3643         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3644         char *oldmnt = cifs_sb->ctx->mount_options;
3645
3646         cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
3647                  dfs_cache_get_tgt_name(tit));
3648
3649         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3650         if (rc)
3651                 goto out;
3652
3653         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3654         if (rc)
3655                 goto out;
3656
3657         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3658         if (oldmnt != cifs_sb->ctx->mount_options) {
3659                 mount_put_conns(mnt_ctx);
3660                 rc = mount_get_dfs_conns(mnt_ctx);
3661         }
3662         if (!rc) {
3663                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3664                         set_root_ses(mnt_ctx);
3665                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3666                                               cifs_remap(cifs_sb), ref_path, tit);
3667         }
3668
3669 out:
3670         free_dfs_info_param(&ref);
3671         return rc;
3672 }
3673
3674 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3675 {
3676         int rc;
3677         char *full_path;
3678         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3679         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3680         struct dfs_cache_tgt_iterator *tit;
3681
3682         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3683          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3684          * now on.
3685          */
3686         mount_put_conns(mnt_ctx);
3687         mount_get_dfs_conns(mnt_ctx);
3688         set_root_ses(mnt_ctx);
3689
3690         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3691         if (IS_ERR(full_path))
3692                 return PTR_ERR(full_path);
3693
3694         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3695                                                             cifs_remap(cifs_sb));
3696         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3697                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3698                 mnt_ctx->origin_fullpath = NULL;
3699                 goto out;
3700         }
3701
3702         /* Try all dfs root targets */
3703         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3704              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3705                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3706                 if (!rc) {
3707                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3708                         if (!mnt_ctx->leaf_fullpath)
3709                                 rc = -ENOMEM;
3710                         break;
3711                 }
3712         }
3713
3714 out:
3715         kfree(full_path);
3716         return rc;
3717 }
3718
3719 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3720 {
3721         int rc;
3722         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3723         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3724         char *full_path;
3725         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3726         struct dfs_cache_tgt_iterator *tit;
3727
3728         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3729         if (IS_ERR(full_path))
3730                 return PTR_ERR(full_path);
3731
3732         kfree(mnt_ctx->leaf_fullpath);
3733         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3734                                                           cifs_remap(cifs_sb));
3735         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3736                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3737                 mnt_ctx->leaf_fullpath = NULL;
3738                 goto out;
3739         }
3740
3741         /* Get referral from dfs link */
3742         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3743                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3744         if (rc)
3745                 goto out;
3746
3747         /* Try all dfs link targets.  If an I/O fails from currently connected DFS target with an
3748          * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
3749          * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
3750          * STATUS_PATH_NOT_COVERED."
3751          */
3752         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3753              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3754                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3755                 if (!rc) {
3756                         rc = is_path_remote(mnt_ctx);
3757                         if (!rc || rc == -EREMOTE)
3758                                 break;
3759                 }
3760         }
3761
3762 out:
3763         kfree(full_path);
3764         dfs_cache_free_tgts(&tl);
3765         return rc;
3766 }
3767
3768 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3769 {
3770         int rc;
3771         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3772         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3773         char *full_path;
3774         int num_links = 0;
3775
3776         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3777         if (IS_ERR(full_path))
3778                 return PTR_ERR(full_path);
3779
3780         kfree(mnt_ctx->origin_fullpath);
3781         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3782                                                             cifs_remap(cifs_sb));
3783         kfree(full_path);
3784
3785         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3786                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3787                 mnt_ctx->origin_fullpath = NULL;
3788                 return rc;
3789         }
3790
3791         do {
3792                 rc = __follow_dfs_link(mnt_ctx);
3793                 if (!rc || rc != -EREMOTE)
3794                         break;
3795         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3796
3797         return rc;
3798 }
3799
3800 /* Set up DFS referral paths for failover */
3801 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3802 {
3803         struct TCP_Server_Info *server = mnt_ctx->server;
3804
3805         mutex_lock(&server->refpath_lock);
3806         server->origin_fullpath = mnt_ctx->origin_fullpath;
3807         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3808         server->current_fullpath = mnt_ctx->leaf_fullpath;
3809         mutex_unlock(&server->refpath_lock);
3810         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3811 }
3812
3813 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3814 {
3815         int rc;
3816         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3817         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3818         bool isdfs;
3819
3820         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3821         if (rc)
3822                 goto error;
3823         if (!isdfs)
3824                 goto out;
3825
3826         /* proceed as DFS mount */
3827         uuid_gen(&mnt_ctx.mount_id);
3828         rc = connect_dfs_root(&mnt_ctx, &tl);
3829         dfs_cache_free_tgts(&tl);
3830
3831         if (rc)
3832                 goto error;
3833
3834         rc = is_path_remote(&mnt_ctx);
3835         if (rc)
3836                 rc = follow_dfs_link(&mnt_ctx);
3837         if (rc)
3838                 goto error;
3839
3840         setup_server_referral_paths(&mnt_ctx);
3841         /*
3842          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3843          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3844          */
3845         cifs_autodisable_serverino(cifs_sb);
3846         /*
3847          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3848          * that have different prefix paths.
3849          */
3850         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3851         kfree(cifs_sb->prepath);
3852         cifs_sb->prepath = ctx->prepath;
3853         ctx->prepath = NULL;
3854         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3855
3856 out:
3857         free_xid(mnt_ctx.xid);
3858         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3859         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3860
3861 error:
3862         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3863         kfree(mnt_ctx.origin_fullpath);
3864         kfree(mnt_ctx.leaf_fullpath);
3865         mount_put_conns(&mnt_ctx);
3866         return rc;
3867 }
3868 #else
3869 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3870 {
3871         int rc = 0;
3872         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3873
3874         rc = mount_get_conns(&mnt_ctx);
3875         if (rc)
3876                 goto error;
3877
3878         if (mnt_ctx.tcon) {
3879                 rc = is_path_remote(&mnt_ctx);
3880                 if (rc == -EREMOTE)
3881                         rc = -EOPNOTSUPP;
3882                 if (rc)
3883                         goto error;
3884         }
3885
3886         free_xid(mnt_ctx.xid);
3887         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3888
3889 error:
3890         mount_put_conns(&mnt_ctx);
3891         return rc;
3892 }
3893 #endif
3894
3895 /*
3896  * Issue a TREE_CONNECT request.
3897  */
3898 int
3899 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3900          const char *tree, struct cifs_tcon *tcon,
3901          const struct nls_table *nls_codepage)
3902 {
3903         struct smb_hdr *smb_buffer;
3904         struct smb_hdr *smb_buffer_response;
3905         TCONX_REQ *pSMB;
3906         TCONX_RSP *pSMBr;
3907         unsigned char *bcc_ptr;
3908         int rc = 0;
3909         int length;
3910         __u16 bytes_left, count;
3911
3912         if (ses == NULL)
3913                 return -EIO;
3914
3915         smb_buffer = cifs_buf_get();
3916         if (smb_buffer == NULL)
3917                 return -ENOMEM;
3918
3919         smb_buffer_response = smb_buffer;
3920
3921         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3922                         NULL /*no tid */ , 4 /*wct */ );
3923
3924         smb_buffer->Mid = get_next_mid(ses->server);
3925         smb_buffer->Uid = ses->Suid;
3926         pSMB = (TCONX_REQ *) smb_buffer;
3927         pSMBr = (TCONX_RSP *) smb_buffer_response;
3928
3929         pSMB->AndXCommand = 0xFF;
3930         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3931         bcc_ptr = &pSMB->Password[0];
3932
3933         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3934         *bcc_ptr = 0; /* password is null byte */
3935         bcc_ptr++;              /* skip password */
3936         /* already aligned so no need to do it below */
3937
3938         if (ses->server->sign)
3939                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3940
3941         if (ses->capabilities & CAP_STATUS32) {
3942                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3943         }
3944         if (ses->capabilities & CAP_DFS) {
3945                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3946         }
3947         if (ses->capabilities & CAP_UNICODE) {
3948                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3949                 length =
3950                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3951                         6 /* max utf8 char length in bytes */ *
3952                         (/* server len*/ + 256 /* share len */), nls_codepage);
3953                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3954                 bcc_ptr += 2;   /* skip trailing null */
3955         } else {                /* ASCII */
3956                 strcpy(bcc_ptr, tree);
3957                 bcc_ptr += strlen(tree) + 1;
3958         }
3959         strcpy(bcc_ptr, "?????");
3960         bcc_ptr += strlen("?????");
3961         bcc_ptr += 1;
3962         count = bcc_ptr - &pSMB->Password[0];
3963         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3964         pSMB->ByteCount = cpu_to_le16(count);
3965
3966         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3967                          0);
3968
3969         /* above now done in SendReceive */
3970         if (rc == 0) {
3971                 bool is_unicode;
3972
3973                 tcon->tid = smb_buffer_response->Tid;
3974                 bcc_ptr = pByteArea(smb_buffer_response);
3975                 bytes_left = get_bcc(smb_buffer_response);
3976                 length = strnlen(bcc_ptr, bytes_left - 2);
3977                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3978                         is_unicode = true;
3979                 else
3980                         is_unicode = false;
3981
3982
3983                 /* skip service field (NB: this field is always ASCII) */
3984                 if (length == 3) {
3985                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3986                             (bcc_ptr[2] == 'C')) {
3987                                 cifs_dbg(FYI, "IPC connection\n");
3988                                 tcon->ipc = true;
3989                                 tcon->pipe = true;
3990                         }
3991                 } else if (length == 2) {
3992                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3993                                 /* the most common case */
3994                                 cifs_dbg(FYI, "disk share connection\n");
3995                         }
3996                 }
3997                 bcc_ptr += length + 1;
3998                 bytes_left -= (length + 1);
3999                 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
4000
4001                 /* mostly informational -- no need to fail on error here */
4002                 kfree(tcon->nativeFileSystem);
4003                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
4004                                                       bytes_left, is_unicode,
4005                                                       nls_codepage);
4006
4007                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
4008
4009                 if ((smb_buffer_response->WordCount == 3) ||
4010                          (smb_buffer_response->WordCount == 7))
4011                         /* field is in same location */
4012                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
4013                 else
4014                         tcon->Flags = 0;
4015                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
4016         }
4017
4018         cifs_buf_release(smb_buffer);
4019         return rc;
4020 }
4021
4022 static void delayed_free(struct rcu_head *p)
4023 {
4024         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
4025
4026         unload_nls(cifs_sb->local_nls);
4027         smb3_cleanup_fs_context(cifs_sb->ctx);
4028         kfree(cifs_sb);
4029 }
4030
4031 void
4032 cifs_umount(struct cifs_sb_info *cifs_sb)
4033 {
4034         struct rb_root *root = &cifs_sb->tlink_tree;
4035         struct rb_node *node;
4036         struct tcon_link *tlink;
4037
4038         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
4039
4040         spin_lock(&cifs_sb->tlink_tree_lock);
4041         while ((node = rb_first(root))) {
4042                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4043                 cifs_get_tlink(tlink);
4044                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4045                 rb_erase(node, root);
4046
4047                 spin_unlock(&cifs_sb->tlink_tree_lock);
4048                 cifs_put_tlink(tlink);
4049                 spin_lock(&cifs_sb->tlink_tree_lock);
4050         }
4051         spin_unlock(&cifs_sb->tlink_tree_lock);
4052
4053         kfree(cifs_sb->prepath);
4054 #ifdef CONFIG_CIFS_DFS_UPCALL
4055         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
4056 #endif
4057         call_rcu(&cifs_sb->rcu, delayed_free);
4058 }
4059
4060 int
4061 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
4062                         struct TCP_Server_Info *server)
4063 {
4064         int rc = 0;
4065
4066         if (!server->ops->need_neg || !server->ops->negotiate)
4067                 return -ENOSYS;
4068
4069         /* only send once per connect */
4070         spin_lock(&server->srv_lock);
4071         if (!server->ops->need_neg(server) ||
4072             server->tcpStatus != CifsNeedNegotiate) {
4073                 spin_unlock(&server->srv_lock);
4074                 return 0;
4075         }
4076         server->tcpStatus = CifsInNegotiate;
4077         spin_unlock(&server->srv_lock);
4078
4079         rc = server->ops->negotiate(xid, ses, server);
4080         if (rc == 0) {
4081                 spin_lock(&server->srv_lock);
4082                 if (server->tcpStatus == CifsInNegotiate)
4083                         server->tcpStatus = CifsGood;
4084                 else
4085                         rc = -EHOSTDOWN;
4086                 spin_unlock(&server->srv_lock);
4087         } else {
4088                 spin_lock(&server->srv_lock);
4089                 if (server->tcpStatus == CifsInNegotiate)
4090                         server->tcpStatus = CifsNeedNegotiate;
4091                 spin_unlock(&server->srv_lock);
4092         }
4093
4094         return rc;
4095 }
4096
4097 int
4098 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
4099                    struct TCP_Server_Info *server,
4100                    struct nls_table *nls_info)
4101 {
4102         int rc = -ENOSYS;
4103         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
4104         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
4105         bool is_binding = false;
4106
4107         spin_lock(&ses->ses_lock);
4108         if (server->dstaddr.ss_family == AF_INET6)
4109                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
4110         else
4111                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
4112
4113         if (ses->ses_status != SES_GOOD &&
4114             ses->ses_status != SES_NEW &&
4115             ses->ses_status != SES_NEED_RECON) {
4116                 spin_unlock(&ses->ses_lock);
4117                 return 0;
4118         }
4119
4120         /* only send once per connect */
4121         spin_lock(&ses->chan_lock);
4122         if (CIFS_ALL_CHANS_GOOD(ses) ||
4123             cifs_chan_in_reconnect(ses, server)) {
4124                 spin_unlock(&ses->chan_lock);
4125                 spin_unlock(&ses->ses_lock);
4126                 return 0;
4127         }
4128         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
4129         cifs_chan_set_in_reconnect(ses, server);
4130         spin_unlock(&ses->chan_lock);
4131
4132         if (!is_binding)
4133                 ses->ses_status = SES_IN_SETUP;
4134         spin_unlock(&ses->ses_lock);
4135
4136         if (!is_binding) {
4137                 ses->capabilities = server->capabilities;
4138                 if (!linuxExtEnabled)
4139                         ses->capabilities &= (~server->vals->cap_unix);
4140
4141                 if (ses->auth_key.response) {
4142                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
4143                                  ses->auth_key.response);
4144                         kfree_sensitive(ses->auth_key.response);
4145                         ses->auth_key.response = NULL;
4146                         ses->auth_key.len = 0;
4147                 }
4148         }
4149
4150         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
4151                  server->sec_mode, server->capabilities, server->timeAdj);
4152
4153         if (server->ops->sess_setup)
4154                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
4155
4156         if (rc) {
4157                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4158                 spin_lock(&ses->ses_lock);
4159                 if (ses->ses_status == SES_IN_SETUP)
4160                         ses->ses_status = SES_NEED_RECON;
4161                 spin_lock(&ses->chan_lock);
4162                 cifs_chan_clear_in_reconnect(ses, server);
4163                 spin_unlock(&ses->chan_lock);
4164                 spin_unlock(&ses->ses_lock);
4165         } else {
4166                 spin_lock(&ses->ses_lock);
4167                 if (ses->ses_status == SES_IN_SETUP)
4168                         ses->ses_status = SES_GOOD;
4169                 spin_lock(&ses->chan_lock);
4170                 cifs_chan_clear_in_reconnect(ses, server);
4171                 cifs_chan_clear_need_reconnect(ses, server);
4172                 spin_unlock(&ses->chan_lock);
4173                 spin_unlock(&ses->ses_lock);
4174         }
4175
4176         return rc;
4177 }
4178
4179 static int
4180 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4181 {
4182         ctx->sectype = ses->sectype;
4183
4184         /* krb5 is special, since we don't need username or pw */
4185         if (ctx->sectype == Kerberos)
4186                 return 0;
4187
4188         return cifs_set_cifscreds(ctx, ses);
4189 }
4190
4191 static struct cifs_tcon *
4192 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4193 {
4194         int rc;
4195         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4196         struct cifs_ses *ses;
4197         struct cifs_tcon *tcon = NULL;
4198         struct smb3_fs_context *ctx;
4199
4200         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4201         if (ctx == NULL)
4202                 return ERR_PTR(-ENOMEM);
4203
4204         ctx->local_nls = cifs_sb->local_nls;
4205         ctx->linux_uid = fsuid;
4206         ctx->cred_uid = fsuid;
4207         ctx->UNC = master_tcon->tree_name;
4208         ctx->retry = master_tcon->retry;
4209         ctx->nocase = master_tcon->nocase;
4210         ctx->nohandlecache = master_tcon->nohandlecache;
4211         ctx->local_lease = master_tcon->local_lease;
4212         ctx->no_lease = master_tcon->no_lease;
4213         ctx->resilient = master_tcon->use_resilient;
4214         ctx->persistent = master_tcon->use_persistent;
4215         ctx->handle_timeout = master_tcon->handle_timeout;
4216         ctx->no_linux_ext = !master_tcon->unix_ext;
4217         ctx->linux_ext = master_tcon->posix_extensions;
4218         ctx->sectype = master_tcon->ses->sectype;
4219         ctx->sign = master_tcon->ses->sign;
4220         ctx->seal = master_tcon->seal;
4221         ctx->witness = master_tcon->use_witness;
4222
4223         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4224         if (rc) {
4225                 tcon = ERR_PTR(rc);
4226                 goto out;
4227         }
4228
4229         /* get a reference for the same TCP session */
4230         spin_lock(&cifs_tcp_ses_lock);
4231         ++master_tcon->ses->server->srv_count;
4232         spin_unlock(&cifs_tcp_ses_lock);
4233
4234         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4235         if (IS_ERR(ses)) {
4236                 tcon = (struct cifs_tcon *)ses;
4237                 cifs_put_tcp_session(master_tcon->ses->server, 0);
4238                 goto out;
4239         }
4240
4241         tcon = cifs_get_tcon(ses, ctx);
4242         if (IS_ERR(tcon)) {
4243                 cifs_put_smb_ses(ses);
4244                 goto out;
4245         }
4246
4247 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
4248         if (cap_unix(ses))
4249                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4250 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
4251
4252 out:
4253         kfree(ctx->username);
4254         kfree_sensitive(ctx->password);
4255         kfree(ctx);
4256
4257         return tcon;
4258 }
4259
4260 struct cifs_tcon *
4261 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4262 {
4263         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4264 }
4265
4266 /* find and return a tlink with given uid */
4267 static struct tcon_link *
4268 tlink_rb_search(struct rb_root *root, kuid_t uid)
4269 {
4270         struct rb_node *node = root->rb_node;
4271         struct tcon_link *tlink;
4272
4273         while (node) {
4274                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4275
4276                 if (uid_gt(tlink->tl_uid, uid))
4277                         node = node->rb_left;
4278                 else if (uid_lt(tlink->tl_uid, uid))
4279                         node = node->rb_right;
4280                 else
4281                         return tlink;
4282         }
4283         return NULL;
4284 }
4285
4286 /* insert a tcon_link into the tree */
4287 static void
4288 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4289 {
4290         struct rb_node **new = &(root->rb_node), *parent = NULL;
4291         struct tcon_link *tlink;
4292
4293         while (*new) {
4294                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4295                 parent = *new;
4296
4297                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4298                         new = &((*new)->rb_left);
4299                 else
4300                         new = &((*new)->rb_right);
4301         }
4302
4303         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4304         rb_insert_color(&new_tlink->tl_rbnode, root);
4305 }
4306
4307 /*
4308  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4309  * current task.
4310  *
4311  * If the superblock doesn't refer to a multiuser mount, then just return
4312  * the master tcon for the mount.
4313  *
4314  * First, search the rbtree for an existing tcon for this fsuid. If one
4315  * exists, then check to see if it's pending construction. If it is then wait
4316  * for construction to complete. Once it's no longer pending, check to see if
4317  * it failed and either return an error or retry construction, depending on
4318  * the timeout.
4319  *
4320  * If one doesn't exist then insert a new tcon_link struct into the tree and
4321  * try to construct a new one.
4322  */
4323 struct tcon_link *
4324 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4325 {
4326         int ret;
4327         kuid_t fsuid = current_fsuid();
4328         struct tcon_link *tlink, *newtlink;
4329
4330         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4331                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4332
4333         spin_lock(&cifs_sb->tlink_tree_lock);
4334         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4335         if (tlink)
4336                 cifs_get_tlink(tlink);
4337         spin_unlock(&cifs_sb->tlink_tree_lock);
4338
4339         if (tlink == NULL) {
4340                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4341                 if (newtlink == NULL)
4342                         return ERR_PTR(-ENOMEM);
4343                 newtlink->tl_uid = fsuid;
4344                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4345                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4346                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4347                 cifs_get_tlink(newtlink);
4348
4349                 spin_lock(&cifs_sb->tlink_tree_lock);
4350                 /* was one inserted after previous search? */
4351                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4352                 if (tlink) {
4353                         cifs_get_tlink(tlink);
4354                         spin_unlock(&cifs_sb->tlink_tree_lock);
4355                         kfree(newtlink);
4356                         goto wait_for_construction;
4357                 }
4358                 tlink = newtlink;
4359                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4360                 spin_unlock(&cifs_sb->tlink_tree_lock);
4361         } else {
4362 wait_for_construction:
4363                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4364                                   TASK_INTERRUPTIBLE);
4365                 if (ret) {
4366                         cifs_put_tlink(tlink);
4367                         return ERR_PTR(-ERESTARTSYS);
4368                 }
4369
4370                 /* if it's good, return it */
4371                 if (!IS_ERR(tlink->tl_tcon))
4372                         return tlink;
4373
4374                 /* return error if we tried this already recently */
4375                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4376                         cifs_put_tlink(tlink);
4377                         return ERR_PTR(-EACCES);
4378                 }
4379
4380                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4381                         goto wait_for_construction;
4382         }
4383
4384         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4385         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4386         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4387
4388         if (IS_ERR(tlink->tl_tcon)) {
4389                 cifs_put_tlink(tlink);
4390                 return ERR_PTR(-EACCES);
4391         }
4392
4393         return tlink;
4394 }
4395
4396 /*
4397  * periodic workqueue job that scans tcon_tree for a superblock and closes
4398  * out tcons.
4399  */
4400 static void
4401 cifs_prune_tlinks(struct work_struct *work)
4402 {
4403         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4404                                                     prune_tlinks.work);
4405         struct rb_root *root = &cifs_sb->tlink_tree;
4406         struct rb_node *node;
4407         struct rb_node *tmp;
4408         struct tcon_link *tlink;
4409
4410         /*
4411          * Because we drop the spinlock in the loop in order to put the tlink
4412          * it's not guarded against removal of links from the tree. The only
4413          * places that remove entries from the tree are this function and
4414          * umounts. Because this function is non-reentrant and is canceled
4415          * before umount can proceed, this is safe.
4416          */
4417         spin_lock(&cifs_sb->tlink_tree_lock);
4418         node = rb_first(root);
4419         while (node != NULL) {
4420                 tmp = node;
4421                 node = rb_next(tmp);
4422                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4423
4424                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4425                     atomic_read(&tlink->tl_count) != 0 ||
4426                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4427                         continue;
4428
4429                 cifs_get_tlink(tlink);
4430                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4431                 rb_erase(tmp, root);
4432
4433                 spin_unlock(&cifs_sb->tlink_tree_lock);
4434                 cifs_put_tlink(tlink);
4435                 spin_lock(&cifs_sb->tlink_tree_lock);
4436         }
4437         spin_unlock(&cifs_sb->tlink_tree_lock);
4438
4439         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4440                                 TLINK_IDLE_EXPIRE);
4441 }
4442
4443 #ifdef CONFIG_CIFS_DFS_UPCALL
4444 /* Update dfs referral path of superblock */
4445 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4446                                   const char *target)
4447 {
4448         int rc = 0;
4449         size_t len = strlen(target);
4450         char *refpath, *npath;
4451
4452         if (unlikely(len < 2 || *target != '\\'))
4453                 return -EINVAL;
4454
4455         if (target[1] == '\\') {
4456                 len += 1;
4457                 refpath = kmalloc(len, GFP_KERNEL);
4458                 if (!refpath)
4459                         return -ENOMEM;
4460
4461                 scnprintf(refpath, len, "%s", target);
4462         } else {
4463                 len += sizeof("\\");
4464                 refpath = kmalloc(len, GFP_KERNEL);
4465                 if (!refpath)
4466                         return -ENOMEM;
4467
4468                 scnprintf(refpath, len, "\\%s", target);
4469         }
4470
4471         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4472         kfree(refpath);
4473
4474         if (IS_ERR(npath)) {
4475                 rc = PTR_ERR(npath);
4476         } else {
4477                 mutex_lock(&server->refpath_lock);
4478                 kfree(server->leaf_fullpath);
4479                 server->leaf_fullpath = npath;
4480                 mutex_unlock(&server->refpath_lock);
4481                 server->current_fullpath = server->leaf_fullpath;
4482         }
4483         return rc;
4484 }
4485
4486 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4487                                        size_t tcp_host_len, char *share, bool *target_match)
4488 {
4489         int rc = 0;
4490         const char *dfs_host;
4491         size_t dfs_host_len;
4492
4493         *target_match = true;
4494         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4495
4496         /* Check if hostnames or addresses match */
4497         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4498                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4499                          dfs_host, (int)tcp_host_len, tcp_host);
4500                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4501                 if (rc)
4502                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4503         }
4504         return rc;
4505 }
4506
4507 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4508                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4509                                      struct dfs_cache_tgt_list *tl)
4510 {
4511         int rc;
4512         struct TCP_Server_Info *server = tcon->ses->server;
4513         const struct smb_version_operations *ops = server->ops;
4514         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4515         char *share = NULL, *prefix = NULL;
4516         const char *tcp_host;
4517         size_t tcp_host_len;
4518         struct dfs_cache_tgt_iterator *tit;
4519         bool target_match;
4520
4521         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4522
4523         tit = dfs_cache_get_tgt_iterator(tl);
4524         if (!tit) {
4525                 rc = -ENOENT;
4526                 goto out;
4527         }
4528
4529         /* Try to tree connect to all dfs targets */
4530         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4531                 const char *target = dfs_cache_get_tgt_name(tit);
4532                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4533
4534                 kfree(share);
4535                 kfree(prefix);
4536                 share = prefix = NULL;
4537
4538                 /* Check if share matches with tcp ses */
4539                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4540                 if (rc) {
4541                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4542                         break;
4543                 }
4544
4545                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4546                                                  &target_match);
4547                 if (rc)
4548                         break;
4549                 if (!target_match) {
4550                         rc = -EHOSTUNREACH;
4551                         continue;
4552                 }
4553
4554                 if (ipc->need_reconnect) {
4555                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4556                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4557                         if (rc)
4558                                 break;
4559                 }
4560
4561                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4562                 if (!islink) {
4563                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4564                         break;
4565                 }
4566                 /*
4567                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4568                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4569                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4570                  * newly resolved target.
4571                  */
4572                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4573                                    NULL, &ntl)) {
4574                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4575                         if (rc)
4576                                 continue;
4577                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4578                         if (!rc)
4579                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4580                 } else {
4581                         /* Target is another dfs share */
4582                         rc = update_server_fullpath(server, cifs_sb, target);
4583                         dfs_cache_free_tgts(tl);
4584
4585                         if (!rc) {
4586                                 rc = -EREMOTE;
4587                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4588                         } else
4589                                 dfs_cache_free_tgts(&ntl);
4590                 }
4591                 break;
4592         }
4593
4594 out:
4595         kfree(share);
4596         kfree(prefix);
4597
4598         return rc;
4599 }
4600
4601 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4602                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4603                                    struct dfs_cache_tgt_list *tl)
4604 {
4605         int rc;
4606         int num_links = 0;
4607         struct TCP_Server_Info *server = tcon->ses->server;
4608
4609         do {
4610                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4611                 if (!rc || rc != -EREMOTE)
4612                         break;
4613         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4614         /*
4615          * If we couldn't tree connect to any targets from last referral path, then retry from
4616          * original referral path.
4617          */
4618         if (rc && server->current_fullpath != server->origin_fullpath) {
4619                 server->current_fullpath = server->origin_fullpath;
4620                 cifs_signal_cifsd_for_reconnect(server, true);
4621         }
4622
4623         dfs_cache_free_tgts(tl);
4624         return rc;
4625 }
4626
4627 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4628 {
4629         int rc;
4630         struct TCP_Server_Info *server = tcon->ses->server;
4631         const struct smb_version_operations *ops = server->ops;
4632         struct super_block *sb = NULL;
4633         struct cifs_sb_info *cifs_sb;
4634         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4635         char *tree;
4636         struct dfs_info3_param ref = {0};
4637
4638         /* only send once per connect */
4639         spin_lock(&tcon->tc_lock);
4640         if (tcon->ses->ses_status != SES_GOOD ||
4641             (tcon->status != TID_NEW &&
4642             tcon->status != TID_NEED_TCON)) {
4643                 spin_unlock(&tcon->tc_lock);
4644                 return 0;
4645         }
4646         tcon->status = TID_IN_TCON;
4647         spin_unlock(&tcon->tc_lock);
4648
4649         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4650         if (!tree) {
4651                 rc = -ENOMEM;
4652                 goto out;
4653         }
4654
4655         if (tcon->ipc) {
4656                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4657                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4658                 goto out;
4659         }
4660
4661         sb = cifs_get_tcp_super(server);
4662         if (IS_ERR(sb)) {
4663                 rc = PTR_ERR(sb);
4664                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4665                 goto out;
4666         }
4667
4668         cifs_sb = CIFS_SB(sb);
4669
4670         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4671         if (!server->current_fullpath ||
4672             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4673                 rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls);
4674                 goto out;
4675         }
4676
4677         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4678                                      &tl);
4679         free_dfs_info_param(&ref);
4680
4681 out:
4682         kfree(tree);
4683         cifs_put_tcp_super(sb);
4684
4685         if (rc) {
4686                 spin_lock(&tcon->tc_lock);
4687                 if (tcon->status == TID_IN_TCON)
4688                         tcon->status = TID_NEED_TCON;
4689                 spin_unlock(&tcon->tc_lock);
4690         } else {
4691                 spin_lock(&tcon->tc_lock);
4692                 if (tcon->status == TID_IN_TCON)
4693                         tcon->status = TID_GOOD;
4694                 spin_unlock(&tcon->tc_lock);
4695                 tcon->need_reconnect = false;
4696         }
4697
4698         return rc;
4699 }
4700 #else
4701 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4702 {
4703         int rc;
4704         const struct smb_version_operations *ops = tcon->ses->server->ops;
4705
4706         /* only send once per connect */
4707         spin_lock(&tcon->tc_lock);
4708         if (tcon->ses->ses_status != SES_GOOD ||
4709             (tcon->status != TID_NEW &&
4710             tcon->status != TID_NEED_TCON)) {
4711                 spin_unlock(&tcon->tc_lock);
4712                 return 0;
4713         }
4714         tcon->status = TID_IN_TCON;
4715         spin_unlock(&tcon->tc_lock);
4716
4717         rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4718         if (rc) {
4719                 spin_lock(&tcon->tc_lock);
4720                 if (tcon->status == TID_IN_TCON)
4721                         tcon->status = TID_NEED_TCON;
4722                 spin_unlock(&tcon->tc_lock);
4723         } else {
4724                 spin_lock(&tcon->tc_lock);
4725                 if (tcon->status == TID_IN_TCON)
4726                         tcon->status = TID_GOOD;
4727                 tcon->need_reconnect = false;
4728                 spin_unlock(&tcon->tc_lock);
4729         }
4730
4731         return rc;
4732 }
4733 #endif