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         server->hostname = NULL;
1588
1589         task = xchg(&server->tsk, NULL);
1590         if (task)
1591                 send_sig(SIGKILL, task, 1);
1592 }
1593
1594 struct TCP_Server_Info *
1595 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1596                      struct TCP_Server_Info *primary_server)
1597 {
1598         struct TCP_Server_Info *tcp_ses = NULL;
1599         int rc;
1600
1601         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1602
1603         /* see if we already have a matching tcp_ses */
1604         tcp_ses = cifs_find_tcp_session(ctx);
1605         if (tcp_ses)
1606                 return tcp_ses;
1607
1608         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1609         if (!tcp_ses) {
1610                 rc = -ENOMEM;
1611                 goto out_err;
1612         }
1613
1614         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1615         if (!tcp_ses->hostname) {
1616                 rc = -ENOMEM;
1617                 goto out_err;
1618         }
1619
1620         if (ctx->nosharesock)
1621                 tcp_ses->nosharesock = true;
1622
1623         tcp_ses->ops = ctx->ops;
1624         tcp_ses->vals = ctx->vals;
1625         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1626
1627         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1628         tcp_ses->noblockcnt = ctx->rootfs;
1629         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1630         tcp_ses->noautotune = ctx->noautotune;
1631         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1632         tcp_ses->rdma = ctx->rdma;
1633         tcp_ses->in_flight = 0;
1634         tcp_ses->max_in_flight = 0;
1635         tcp_ses->credits = 1;
1636         if (primary_server) {
1637                 spin_lock(&cifs_tcp_ses_lock);
1638                 ++primary_server->srv_count;
1639                 spin_unlock(&cifs_tcp_ses_lock);
1640                 tcp_ses->primary_server = primary_server;
1641         }
1642         init_waitqueue_head(&tcp_ses->response_q);
1643         init_waitqueue_head(&tcp_ses->request_q);
1644         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1645         mutex_init(&tcp_ses->_srv_mutex);
1646         memcpy(tcp_ses->workstation_RFC1001_name,
1647                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1648         memcpy(tcp_ses->server_RFC1001_name,
1649                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1650         tcp_ses->session_estab = false;
1651         tcp_ses->sequence_number = 0;
1652         tcp_ses->reconnect_instance = 1;
1653         tcp_ses->lstrp = jiffies;
1654         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1655         spin_lock_init(&tcp_ses->req_lock);
1656         spin_lock_init(&tcp_ses->srv_lock);
1657         spin_lock_init(&tcp_ses->mid_lock);
1658         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1659         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1660         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1661         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1662         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1663         mutex_init(&tcp_ses->reconnect_mutex);
1664 #ifdef CONFIG_CIFS_DFS_UPCALL
1665         mutex_init(&tcp_ses->refpath_lock);
1666 #endif
1667         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1668                sizeof(tcp_ses->srcaddr));
1669         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1670                 sizeof(tcp_ses->dstaddr));
1671         if (ctx->use_client_guid)
1672                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1673                        SMB2_CLIENT_GUID_SIZE);
1674         else
1675                 generate_random_uuid(tcp_ses->client_guid);
1676         /*
1677          * at this point we are the only ones with the pointer
1678          * to the struct since the kernel thread not created yet
1679          * no need to spinlock this init of tcpStatus or srv_count
1680          */
1681         tcp_ses->tcpStatus = CifsNew;
1682         ++tcp_ses->srv_count;
1683
1684         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1685                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1686                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1687         else
1688                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1689         if (tcp_ses->rdma) {
1690 #ifndef CONFIG_CIFS_SMB_DIRECT
1691                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1692                 rc = -ENOENT;
1693                 goto out_err_crypto_release;
1694 #endif
1695                 tcp_ses->smbd_conn = smbd_get_connection(
1696                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1697                 if (tcp_ses->smbd_conn) {
1698                         cifs_dbg(VFS, "RDMA transport established\n");
1699                         rc = 0;
1700                         goto smbd_connected;
1701                 } else {
1702                         rc = -ENOENT;
1703                         goto out_err_crypto_release;
1704                 }
1705         }
1706         rc = ip_connect(tcp_ses);
1707         if (rc < 0) {
1708                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1709                 goto out_err_crypto_release;
1710         }
1711 smbd_connected:
1712         /*
1713          * since we're in a cifs function already, we know that
1714          * this will succeed. No need for try_module_get().
1715          */
1716         __module_get(THIS_MODULE);
1717         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1718                                   tcp_ses, "cifsd");
1719         if (IS_ERR(tcp_ses->tsk)) {
1720                 rc = PTR_ERR(tcp_ses->tsk);
1721                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1722                 module_put(THIS_MODULE);
1723                 goto out_err_crypto_release;
1724         }
1725         tcp_ses->min_offload = ctx->min_offload;
1726         /*
1727          * at this point we are the only ones with the pointer
1728          * to the struct since the kernel thread not created yet
1729          * no need to spinlock this update of tcpStatus
1730          */
1731         spin_lock(&tcp_ses->srv_lock);
1732         tcp_ses->tcpStatus = CifsNeedNegotiate;
1733         spin_unlock(&tcp_ses->srv_lock);
1734
1735         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1736                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1737         else
1738                 tcp_ses->max_credits = ctx->max_credits;
1739
1740         tcp_ses->nr_targets = 1;
1741         tcp_ses->ignore_signature = ctx->ignore_signature;
1742         /* thread spawned, put it on the list */
1743         spin_lock(&cifs_tcp_ses_lock);
1744         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1745         spin_unlock(&cifs_tcp_ses_lock);
1746
1747         /* queue echo request delayed work */
1748         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1749
1750         /* queue dns resolution delayed work */
1751         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1752                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1753
1754         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1755
1756         return tcp_ses;
1757
1758 out_err_crypto_release:
1759         cifs_crypto_secmech_release(tcp_ses);
1760
1761         put_net(cifs_net_ns(tcp_ses));
1762
1763 out_err:
1764         if (tcp_ses) {
1765                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1766                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1767                 kfree(tcp_ses->hostname);
1768                 if (tcp_ses->ssocket)
1769                         sock_release(tcp_ses->ssocket);
1770                 kfree(tcp_ses);
1771         }
1772         return ERR_PTR(rc);
1773 }
1774
1775 /* this function must be called with ses_lock held */
1776 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1777 {
1778         if (ctx->sectype != Unspecified &&
1779             ctx->sectype != ses->sectype)
1780                 return 0;
1781
1782         /*
1783          * If an existing session is limited to less channels than
1784          * requested, it should not be reused
1785          */
1786         spin_lock(&ses->chan_lock);
1787         if (ses->chan_max < ctx->max_channels) {
1788                 spin_unlock(&ses->chan_lock);
1789                 return 0;
1790         }
1791         spin_unlock(&ses->chan_lock);
1792
1793         switch (ses->sectype) {
1794         case Kerberos:
1795                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1796                         return 0;
1797                 break;
1798         default:
1799                 /* NULL username means anonymous session */
1800                 if (ses->user_name == NULL) {
1801                         if (!ctx->nullauth)
1802                                 return 0;
1803                         break;
1804                 }
1805
1806                 /* anything else takes username/password */
1807                 if (strncmp(ses->user_name,
1808                             ctx->username ? ctx->username : "",
1809                             CIFS_MAX_USERNAME_LEN))
1810                         return 0;
1811                 if ((ctx->username && strlen(ctx->username) != 0) &&
1812                     ses->password != NULL &&
1813                     strncmp(ses->password,
1814                             ctx->password ? ctx->password : "",
1815                             CIFS_MAX_PASSWORD_LEN))
1816                         return 0;
1817         }
1818         return 1;
1819 }
1820
1821 /**
1822  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1823  * @ses: smb session to issue the request on
1824  * @ctx: the superblock configuration context to use for building the
1825  *       new tree connection for the IPC (interprocess communication RPC)
1826  *
1827  * A new IPC connection is made and stored in the session
1828  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1829  */
1830 static int
1831 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1832 {
1833         int rc = 0, xid;
1834         struct cifs_tcon *tcon;
1835         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1836         bool seal = false;
1837         struct TCP_Server_Info *server = ses->server;
1838
1839         /*
1840          * If the mount request that resulted in the creation of the
1841          * session requires encryption, force IPC to be encrypted too.
1842          */
1843         if (ctx->seal) {
1844                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1845                         seal = true;
1846                 else {
1847                         cifs_server_dbg(VFS,
1848                                  "IPC: server doesn't support encryption\n");
1849                         return -EOPNOTSUPP;
1850                 }
1851         }
1852
1853         tcon = tconInfoAlloc();
1854         if (tcon == NULL)
1855                 return -ENOMEM;
1856
1857         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1858
1859         xid = get_xid();
1860         tcon->ses = ses;
1861         tcon->ipc = true;
1862         tcon->seal = seal;
1863         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1864         free_xid(xid);
1865
1866         if (rc) {
1867                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1868                 tconInfoFree(tcon);
1869                 goto out;
1870         }
1871
1872         cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1873
1874         ses->tcon_ipc = tcon;
1875 out:
1876         return rc;
1877 }
1878
1879 /**
1880  * cifs_free_ipc - helper to release the session IPC tcon
1881  * @ses: smb session to unmount the IPC from
1882  *
1883  * Needs to be called everytime a session is destroyed.
1884  *
1885  * On session close, the IPC is closed and the server must release all tcons of the session.
1886  * No need to send a tree disconnect here.
1887  *
1888  * Besides, it will make the server to not close durable and resilient files on session close, as
1889  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1890  */
1891 static int
1892 cifs_free_ipc(struct cifs_ses *ses)
1893 {
1894         struct cifs_tcon *tcon = ses->tcon_ipc;
1895
1896         if (tcon == NULL)
1897                 return 0;
1898
1899         tconInfoFree(tcon);
1900         ses->tcon_ipc = NULL;
1901         return 0;
1902 }
1903
1904 static struct cifs_ses *
1905 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1906 {
1907         struct cifs_ses *ses;
1908
1909         spin_lock(&cifs_tcp_ses_lock);
1910         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1911                 spin_lock(&ses->ses_lock);
1912                 if (ses->ses_status == SES_EXITING) {
1913                         spin_unlock(&ses->ses_lock);
1914                         continue;
1915                 }
1916                 if (!match_session(ses, ctx)) {
1917                         spin_unlock(&ses->ses_lock);
1918                         continue;
1919                 }
1920                 spin_unlock(&ses->ses_lock);
1921
1922                 ++ses->ses_count;
1923                 spin_unlock(&cifs_tcp_ses_lock);
1924                 return ses;
1925         }
1926         spin_unlock(&cifs_tcp_ses_lock);
1927         return NULL;
1928 }
1929
1930 void cifs_put_smb_ses(struct cifs_ses *ses)
1931 {
1932         unsigned int rc, xid;
1933         unsigned int chan_count;
1934         struct TCP_Server_Info *server = ses->server;
1935
1936         spin_lock(&ses->ses_lock);
1937         if (ses->ses_status == SES_EXITING) {
1938                 spin_unlock(&ses->ses_lock);
1939                 return;
1940         }
1941         spin_unlock(&ses->ses_lock);
1942
1943         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1944         cifs_dbg(FYI,
1945                  "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1946
1947         spin_lock(&cifs_tcp_ses_lock);
1948         if (--ses->ses_count > 0) {
1949                 spin_unlock(&cifs_tcp_ses_lock);
1950                 return;
1951         }
1952         spin_unlock(&cifs_tcp_ses_lock);
1953
1954         /* ses_count can never go negative */
1955         WARN_ON(ses->ses_count < 0);
1956
1957         if (ses->ses_status == SES_GOOD)
1958                 ses->ses_status = SES_EXITING;
1959
1960         cifs_free_ipc(ses);
1961
1962         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1963                 xid = get_xid();
1964                 rc = server->ops->logoff(xid, ses);
1965                 if (rc)
1966                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1967                                 __func__, rc);
1968                 _free_xid(xid);
1969         }
1970
1971         spin_lock(&cifs_tcp_ses_lock);
1972         list_del_init(&ses->smb_ses_list);
1973         spin_unlock(&cifs_tcp_ses_lock);
1974
1975         chan_count = ses->chan_count;
1976
1977         /* close any extra channels */
1978         if (chan_count > 1) {
1979                 int i;
1980
1981                 for (i = 1; i < chan_count; i++) {
1982                         if (ses->chans[i].iface) {
1983                                 kref_put(&ses->chans[i].iface->refcount, release_iface);
1984                                 ses->chans[i].iface = NULL;
1985                         }
1986                         cifs_put_tcp_session(ses->chans[i].server, 0);
1987                         ses->chans[i].server = NULL;
1988                 }
1989         }
1990
1991         sesInfoFree(ses);
1992         cifs_put_tcp_session(server, 0);
1993 }
1994
1995 #ifdef CONFIG_KEYS
1996
1997 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1998 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1999
2000 /* Populate username and pw fields from keyring if possible */
2001 static int
2002 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2003 {
2004         int rc = 0;
2005         int is_domain = 0;
2006         const char *delim, *payload;
2007         char *desc;
2008         ssize_t len;
2009         struct key *key;
2010         struct TCP_Server_Info *server = ses->server;
2011         struct sockaddr_in *sa;
2012         struct sockaddr_in6 *sa6;
2013         const struct user_key_payload *upayload;
2014
2015         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2016         if (!desc)
2017                 return -ENOMEM;
2018
2019         /* try to find an address key first */
2020         switch (server->dstaddr.ss_family) {
2021         case AF_INET:
2022                 sa = (struct sockaddr_in *)&server->dstaddr;
2023                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2024                 break;
2025         case AF_INET6:
2026                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2027                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2028                 break;
2029         default:
2030                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2031                          server->dstaddr.ss_family);
2032                 rc = -EINVAL;
2033                 goto out_err;
2034         }
2035
2036         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2037         key = request_key(&key_type_logon, desc, "");
2038         if (IS_ERR(key)) {
2039                 if (!ses->domainName) {
2040                         cifs_dbg(FYI, "domainName is NULL\n");
2041                         rc = PTR_ERR(key);
2042                         goto out_err;
2043                 }
2044
2045                 /* didn't work, try to find a domain key */
2046                 sprintf(desc, "cifs:d:%s", ses->domainName);
2047                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2048                 key = request_key(&key_type_logon, desc, "");
2049                 if (IS_ERR(key)) {
2050                         rc = PTR_ERR(key);
2051                         goto out_err;
2052                 }
2053                 is_domain = 1;
2054         }
2055
2056         down_read(&key->sem);
2057         upayload = user_key_payload_locked(key);
2058         if (IS_ERR_OR_NULL(upayload)) {
2059                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2060                 goto out_key_put;
2061         }
2062
2063         /* find first : in payload */
2064         payload = upayload->data;
2065         delim = strnchr(payload, upayload->datalen, ':');
2066         cifs_dbg(FYI, "payload=%s\n", payload);
2067         if (!delim) {
2068                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2069                          upayload->datalen);
2070                 rc = -EINVAL;
2071                 goto out_key_put;
2072         }
2073
2074         len = delim - payload;
2075         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2076                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2077                          len);
2078                 rc = -EINVAL;
2079                 goto out_key_put;
2080         }
2081
2082         ctx->username = kstrndup(payload, len, GFP_KERNEL);
2083         if (!ctx->username) {
2084                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2085                          len);
2086                 rc = -ENOMEM;
2087                 goto out_key_put;
2088         }
2089         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2090
2091         len = key->datalen - (len + 1);
2092         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2093                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2094                 rc = -EINVAL;
2095                 kfree(ctx->username);
2096                 ctx->username = NULL;
2097                 goto out_key_put;
2098         }
2099
2100         ++delim;
2101         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2102         if (!ctx->password) {
2103                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2104                          len);
2105                 rc = -ENOMEM;
2106                 kfree(ctx->username);
2107                 ctx->username = NULL;
2108                 goto out_key_put;
2109         }
2110
2111         /*
2112          * If we have a domain key then we must set the domainName in the
2113          * for the request.
2114          */
2115         if (is_domain && ses->domainName) {
2116                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2117                 if (!ctx->domainname) {
2118                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2119                                  len);
2120                         rc = -ENOMEM;
2121                         kfree(ctx->username);
2122                         ctx->username = NULL;
2123                         kfree_sensitive(ctx->password);
2124                         ctx->password = NULL;
2125                         goto out_key_put;
2126                 }
2127         }
2128
2129         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2130
2131 out_key_put:
2132         up_read(&key->sem);
2133         key_put(key);
2134 out_err:
2135         kfree(desc);
2136         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2137         return rc;
2138 }
2139 #else /* ! CONFIG_KEYS */
2140 static inline int
2141 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2142                    struct cifs_ses *ses __attribute__((unused)))
2143 {
2144         return -ENOSYS;
2145 }
2146 #endif /* CONFIG_KEYS */
2147
2148 /**
2149  * cifs_get_smb_ses - get a session matching @ctx data from @server
2150  * @server: server to setup the session to
2151  * @ctx: superblock configuration context to use to setup the session
2152  *
2153  * This function assumes it is being called from cifs_mount() where we
2154  * already got a server reference (server refcount +1). See
2155  * cifs_get_tcon() for refcount explanations.
2156  */
2157 struct cifs_ses *
2158 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2159 {
2160         int rc = 0;
2161         unsigned int xid;
2162         struct cifs_ses *ses;
2163         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2164         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2165
2166         xid = get_xid();
2167
2168         ses = cifs_find_smb_ses(server, ctx);
2169         if (ses) {
2170                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2171                          ses->ses_status);
2172
2173                 spin_lock(&ses->chan_lock);
2174                 if (cifs_chan_needs_reconnect(ses, server)) {
2175                         spin_unlock(&ses->chan_lock);
2176                         cifs_dbg(FYI, "Session needs reconnect\n");
2177
2178                         mutex_lock(&ses->session_mutex);
2179                         rc = cifs_negotiate_protocol(xid, ses, server);
2180                         if (rc) {
2181                                 mutex_unlock(&ses->session_mutex);
2182                                 /* problem -- put our ses reference */
2183                                 cifs_put_smb_ses(ses);
2184                                 free_xid(xid);
2185                                 return ERR_PTR(rc);
2186                         }
2187
2188                         rc = cifs_setup_session(xid, ses, server,
2189                                                 ctx->local_nls);
2190                         if (rc) {
2191                                 mutex_unlock(&ses->session_mutex);
2192                                 /* problem -- put our reference */
2193                                 cifs_put_smb_ses(ses);
2194                                 free_xid(xid);
2195                                 return ERR_PTR(rc);
2196                         }
2197                         mutex_unlock(&ses->session_mutex);
2198
2199                         spin_lock(&ses->chan_lock);
2200                 }
2201                 spin_unlock(&ses->chan_lock);
2202
2203                 /* existing SMB ses has a server reference already */
2204                 cifs_put_tcp_session(server, 0);
2205                 free_xid(xid);
2206                 return ses;
2207         }
2208
2209         rc = -ENOMEM;
2210
2211         cifs_dbg(FYI, "Existing smb sess not found\n");
2212         ses = sesInfoAlloc();
2213         if (ses == NULL)
2214                 goto get_ses_fail;
2215
2216         /* new SMB session uses our server ref */
2217         ses->server = server;
2218         if (server->dstaddr.ss_family == AF_INET6)
2219                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2220         else
2221                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2222
2223         if (ctx->username) {
2224                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2225                 if (!ses->user_name)
2226                         goto get_ses_fail;
2227         }
2228
2229         /* ctx->password freed at unmount */
2230         if (ctx->password) {
2231                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2232                 if (!ses->password)
2233                         goto get_ses_fail;
2234         }
2235         if (ctx->domainname) {
2236                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2237                 if (!ses->domainName)
2238                         goto get_ses_fail;
2239         }
2240
2241         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2242
2243         if (ctx->domainauto)
2244                 ses->domainAuto = ctx->domainauto;
2245         ses->cred_uid = ctx->cred_uid;
2246         ses->linux_uid = ctx->linux_uid;
2247
2248         ses->sectype = ctx->sectype;
2249         ses->sign = ctx->sign;
2250
2251         /* add server as first channel */
2252         spin_lock(&ses->chan_lock);
2253         ses->chans[0].server = server;
2254         ses->chan_count = 1;
2255         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2256         ses->chans_need_reconnect = 1;
2257         spin_unlock(&ses->chan_lock);
2258
2259         mutex_lock(&ses->session_mutex);
2260         rc = cifs_negotiate_protocol(xid, ses, server);
2261         if (!rc)
2262                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2263         mutex_unlock(&ses->session_mutex);
2264
2265         /* each channel uses a different signing key */
2266         spin_lock(&ses->chan_lock);
2267         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2268                sizeof(ses->smb3signingkey));
2269         spin_unlock(&ses->chan_lock);
2270
2271         if (rc)
2272                 goto get_ses_fail;
2273
2274         /*
2275          * success, put it on the list and add it as first channel
2276          * note: the session becomes active soon after this. So you'll
2277          * need to lock before changing something in the session.
2278          */
2279         spin_lock(&cifs_tcp_ses_lock);
2280         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2281         spin_unlock(&cifs_tcp_ses_lock);
2282
2283         free_xid(xid);
2284
2285         cifs_setup_ipc(ses, ctx);
2286
2287         return ses;
2288
2289 get_ses_fail:
2290         sesInfoFree(ses);
2291         free_xid(xid);
2292         return ERR_PTR(rc);
2293 }
2294
2295 /* this function must be called with tc_lock held */
2296 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2297 {
2298         if (tcon->status == TID_EXITING)
2299                 return 0;
2300         if (strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2301                 return 0;
2302         if (tcon->seal != ctx->seal)
2303                 return 0;
2304         if (tcon->snapshot_time != ctx->snapshot_time)
2305                 return 0;
2306         if (tcon->handle_timeout != ctx->handle_timeout)
2307                 return 0;
2308         if (tcon->no_lease != ctx->no_lease)
2309                 return 0;
2310         if (tcon->nodelete != ctx->nodelete)
2311                 return 0;
2312         return 1;
2313 }
2314
2315 static struct cifs_tcon *
2316 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2317 {
2318         struct cifs_tcon *tcon;
2319
2320         spin_lock(&cifs_tcp_ses_lock);
2321         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2322                 spin_lock(&tcon->tc_lock);
2323                 if (!match_tcon(tcon, ctx)) {
2324                         spin_unlock(&tcon->tc_lock);
2325                         continue;
2326                 }
2327                 ++tcon->tc_count;
2328                 spin_unlock(&tcon->tc_lock);
2329                 spin_unlock(&cifs_tcp_ses_lock);
2330                 return tcon;
2331         }
2332         spin_unlock(&cifs_tcp_ses_lock);
2333         return NULL;
2334 }
2335
2336 void
2337 cifs_put_tcon(struct cifs_tcon *tcon)
2338 {
2339         unsigned int xid;
2340         struct cifs_ses *ses;
2341
2342         /*
2343          * IPC tcon share the lifetime of their session and are
2344          * destroyed in the session put function
2345          */
2346         if (tcon == NULL || tcon->ipc)
2347                 return;
2348
2349         ses = tcon->ses;
2350         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2351         spin_lock(&cifs_tcp_ses_lock);
2352         spin_lock(&tcon->tc_lock);
2353         if (--tcon->tc_count > 0) {
2354                 spin_unlock(&tcon->tc_lock);
2355                 spin_unlock(&cifs_tcp_ses_lock);
2356                 return;
2357         }
2358
2359         /* tc_count can never go negative */
2360         WARN_ON(tcon->tc_count < 0);
2361
2362         list_del_init(&tcon->tcon_list);
2363         spin_unlock(&tcon->tc_lock);
2364         spin_unlock(&cifs_tcp_ses_lock);
2365
2366         /* cancel polling of interfaces */
2367         cancel_delayed_work_sync(&tcon->query_interfaces);
2368
2369         if (tcon->use_witness) {
2370                 int rc;
2371
2372                 rc = cifs_swn_unregister(tcon);
2373                 if (rc < 0) {
2374                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2375                                         __func__, rc);
2376                 }
2377         }
2378
2379         xid = get_xid();
2380         if (ses->server->ops->tree_disconnect)
2381                 ses->server->ops->tree_disconnect(xid, tcon);
2382         _free_xid(xid);
2383
2384         cifs_fscache_release_super_cookie(tcon);
2385         tconInfoFree(tcon);
2386         cifs_put_smb_ses(ses);
2387 }
2388
2389 /**
2390  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2391  * @ses: smb session to issue the request on
2392  * @ctx: the superblock configuration context to use for building the
2393  *
2394  * - tcon refcount is the number of mount points using the tcon.
2395  * - ses refcount is the number of tcon using the session.
2396  *
2397  * 1. This function assumes it is being called from cifs_mount() where
2398  *    we already got a session reference (ses refcount +1).
2399  *
2400  * 2. Since we're in the context of adding a mount point, the end
2401  *    result should be either:
2402  *
2403  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2404  *    its session refcount incremented (1 new tcon). This +1 was
2405  *    already done in (1).
2406  *
2407  * b) an existing tcon with refcount+1 (add a mount point to it) and
2408  *    identical ses refcount (no new tcon). Because of (1) we need to
2409  *    decrement the ses refcount.
2410  */
2411 static struct cifs_tcon *
2412 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2413 {
2414         int rc, xid;
2415         struct cifs_tcon *tcon;
2416
2417         tcon = cifs_find_tcon(ses, ctx);
2418         if (tcon) {
2419                 /*
2420                  * tcon has refcount already incremented but we need to
2421                  * decrement extra ses reference gotten by caller (case b)
2422                  */
2423                 cifs_dbg(FYI, "Found match on UNC path\n");
2424                 cifs_put_smb_ses(ses);
2425                 return tcon;
2426         }
2427
2428         if (!ses->server->ops->tree_connect) {
2429                 rc = -ENOSYS;
2430                 goto out_fail;
2431         }
2432
2433         tcon = tconInfoAlloc();
2434         if (tcon == NULL) {
2435                 rc = -ENOMEM;
2436                 goto out_fail;
2437         }
2438
2439         if (ctx->snapshot_time) {
2440                 if (ses->server->vals->protocol_id == 0) {
2441                         cifs_dbg(VFS,
2442                              "Use SMB2 or later for snapshot mount option\n");
2443                         rc = -EOPNOTSUPP;
2444                         goto out_fail;
2445                 } else
2446                         tcon->snapshot_time = ctx->snapshot_time;
2447         }
2448
2449         if (ctx->handle_timeout) {
2450                 if (ses->server->vals->protocol_id == 0) {
2451                         cifs_dbg(VFS,
2452                              "Use SMB2.1 or later for handle timeout option\n");
2453                         rc = -EOPNOTSUPP;
2454                         goto out_fail;
2455                 } else
2456                         tcon->handle_timeout = ctx->handle_timeout;
2457         }
2458
2459         tcon->ses = ses;
2460         if (ctx->password) {
2461                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2462                 if (!tcon->password) {
2463                         rc = -ENOMEM;
2464                         goto out_fail;
2465                 }
2466         }
2467
2468         if (ctx->seal) {
2469                 if (ses->server->vals->protocol_id == 0) {
2470                         cifs_dbg(VFS,
2471                                  "SMB3 or later required for encryption\n");
2472                         rc = -EOPNOTSUPP;
2473                         goto out_fail;
2474                 } else if (tcon->ses->server->capabilities &
2475                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2476                         tcon->seal = true;
2477                 else {
2478                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2479                         rc = -EOPNOTSUPP;
2480                         goto out_fail;
2481                 }
2482         }
2483
2484         if (ctx->linux_ext) {
2485                 if (ses->server->posix_ext_supported) {
2486                         tcon->posix_extensions = true;
2487                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2488                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2489                     (strcmp(ses->server->vals->version_string,
2490                      SMB3ANY_VERSION_STRING) == 0) ||
2491                     (strcmp(ses->server->vals->version_string,
2492                      SMBDEFAULT_VERSION_STRING) == 0)) {
2493                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2494                         rc = -EOPNOTSUPP;
2495                         goto out_fail;
2496                 } else {
2497                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2498                                 "disabled but required for POSIX extensions\n");
2499                         rc = -EOPNOTSUPP;
2500                         goto out_fail;
2501                 }
2502         }
2503
2504         xid = get_xid();
2505         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2506                                             ctx->local_nls);
2507         free_xid(xid);
2508         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2509         if (rc)
2510                 goto out_fail;
2511
2512         tcon->use_persistent = false;
2513         /* check if SMB2 or later, CIFS does not support persistent handles */
2514         if (ctx->persistent) {
2515                 if (ses->server->vals->protocol_id == 0) {
2516                         cifs_dbg(VFS,
2517                              "SMB3 or later required for persistent handles\n");
2518                         rc = -EOPNOTSUPP;
2519                         goto out_fail;
2520                 } else if (ses->server->capabilities &
2521                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2522                         tcon->use_persistent = true;
2523                 else /* persistent handles requested but not supported */ {
2524                         cifs_dbg(VFS,
2525                                 "Persistent handles not supported on share\n");
2526                         rc = -EOPNOTSUPP;
2527                         goto out_fail;
2528                 }
2529         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2530              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2531              && (ctx->nopersistent == false)) {
2532                 cifs_dbg(FYI, "enabling persistent handles\n");
2533                 tcon->use_persistent = true;
2534         } else if (ctx->resilient) {
2535                 if (ses->server->vals->protocol_id == 0) {
2536                         cifs_dbg(VFS,
2537                              "SMB2.1 or later required for resilient handles\n");
2538                         rc = -EOPNOTSUPP;
2539                         goto out_fail;
2540                 }
2541                 tcon->use_resilient = true;
2542         }
2543
2544         tcon->use_witness = false;
2545         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2546                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2547                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2548                                 /*
2549                                  * Set witness in use flag in first place
2550                                  * to retry registration in the echo task
2551                                  */
2552                                 tcon->use_witness = true;
2553                                 /* And try to register immediately */
2554                                 rc = cifs_swn_register(tcon);
2555                                 if (rc < 0) {
2556                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2557                                         goto out_fail;
2558                                 }
2559                         } else {
2560                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2561                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2562                                 rc = -EOPNOTSUPP;
2563                                 goto out_fail;
2564                         }
2565                 } else {
2566                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2567                         rc = -EOPNOTSUPP;
2568                         goto out_fail;
2569                 }
2570         }
2571
2572         /* If the user really knows what they are doing they can override */
2573         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2574                 if (ctx->cache_ro)
2575                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2576                 else if (ctx->cache_rw)
2577                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2578         }
2579
2580         if (ctx->no_lease) {
2581                 if (ses->server->vals->protocol_id == 0) {
2582                         cifs_dbg(VFS,
2583                                 "SMB2 or later required for nolease option\n");
2584                         rc = -EOPNOTSUPP;
2585                         goto out_fail;
2586                 } else
2587                         tcon->no_lease = ctx->no_lease;
2588         }
2589
2590         /*
2591          * We can have only one retry value for a connection to a share so for
2592          * resources mounted more than once to the same server share the last
2593          * value passed in for the retry flag is used.
2594          */
2595         tcon->retry = ctx->retry;
2596         tcon->nocase = ctx->nocase;
2597         tcon->broken_sparse_sup = ctx->no_sparse;
2598         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2599                 tcon->nohandlecache = ctx->nohandlecache;
2600         else
2601                 tcon->nohandlecache = true;
2602         tcon->nodelete = ctx->nodelete;
2603         tcon->local_lease = ctx->local_lease;
2604         INIT_LIST_HEAD(&tcon->pending_opens);
2605
2606         /* schedule query interfaces poll */
2607         INIT_DELAYED_WORK(&tcon->query_interfaces,
2608                           smb2_query_server_interfaces);
2609         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2610                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
2611
2612         spin_lock(&cifs_tcp_ses_lock);
2613         list_add(&tcon->tcon_list, &ses->tcon_list);
2614         spin_unlock(&cifs_tcp_ses_lock);
2615
2616         return tcon;
2617
2618 out_fail:
2619         tconInfoFree(tcon);
2620         return ERR_PTR(rc);
2621 }
2622
2623 void
2624 cifs_put_tlink(struct tcon_link *tlink)
2625 {
2626         if (!tlink || IS_ERR(tlink))
2627                 return;
2628
2629         if (!atomic_dec_and_test(&tlink->tl_count) ||
2630             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2631                 tlink->tl_time = jiffies;
2632                 return;
2633         }
2634
2635         if (!IS_ERR(tlink_tcon(tlink)))
2636                 cifs_put_tcon(tlink_tcon(tlink));
2637         kfree(tlink);
2638         return;
2639 }
2640
2641 static int
2642 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2643 {
2644         struct cifs_sb_info *old = CIFS_SB(sb);
2645         struct cifs_sb_info *new = mnt_data->cifs_sb;
2646         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2647         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2648
2649         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2650                 return 0;
2651
2652         if (old->mnt_cifs_serverino_autodisabled)
2653                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2654
2655         if (oldflags != newflags)
2656                 return 0;
2657
2658         /*
2659          * We want to share sb only if we don't specify an r/wsize or
2660          * specified r/wsize is greater than or equal to existing one.
2661          */
2662         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2663                 return 0;
2664
2665         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2666                 return 0;
2667
2668         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2669             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2670                 return 0;
2671
2672         if (old->ctx->file_mode != new->ctx->file_mode ||
2673             old->ctx->dir_mode != new->ctx->dir_mode)
2674                 return 0;
2675
2676         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2677                 return 0;
2678
2679         if (old->ctx->acregmax != new->ctx->acregmax)
2680                 return 0;
2681         if (old->ctx->acdirmax != new->ctx->acdirmax)
2682                 return 0;
2683         if (old->ctx->closetimeo != new->ctx->closetimeo)
2684                 return 0;
2685
2686         return 1;
2687 }
2688
2689 static int
2690 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2691 {
2692         struct cifs_sb_info *old = CIFS_SB(sb);
2693         struct cifs_sb_info *new = mnt_data->cifs_sb;
2694         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2695                 old->prepath;
2696         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2697                 new->prepath;
2698
2699         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2700                 return 1;
2701         else if (!old_set && !new_set)
2702                 return 1;
2703
2704         return 0;
2705 }
2706
2707 int
2708 cifs_match_super(struct super_block *sb, void *data)
2709 {
2710         struct cifs_mnt_data *mnt_data = data;
2711         struct smb3_fs_context *ctx;
2712         struct cifs_sb_info *cifs_sb;
2713         struct TCP_Server_Info *tcp_srv;
2714         struct cifs_ses *ses;
2715         struct cifs_tcon *tcon;
2716         struct tcon_link *tlink;
2717         int rc = 0;
2718
2719         spin_lock(&cifs_tcp_ses_lock);
2720         cifs_sb = CIFS_SB(sb);
2721         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2722         if (tlink == NULL) {
2723                 /* can not match superblock if tlink were ever null */
2724                 spin_unlock(&cifs_tcp_ses_lock);
2725                 return 0;
2726         }
2727         tcon = tlink_tcon(tlink);
2728         ses = tcon->ses;
2729         tcp_srv = ses->server;
2730
2731         ctx = mnt_data->ctx;
2732
2733         spin_lock(&tcp_srv->srv_lock);
2734         spin_lock(&ses->ses_lock);
2735         spin_lock(&tcon->tc_lock);
2736         if (!match_server(tcp_srv, ctx) ||
2737             !match_session(ses, ctx) ||
2738             !match_tcon(tcon, ctx) ||
2739             !match_prepath(sb, mnt_data)) {
2740                 rc = 0;
2741                 goto out;
2742         }
2743
2744         rc = compare_mount_options(sb, mnt_data);
2745 out:
2746         spin_unlock(&tcon->tc_lock);
2747         spin_unlock(&ses->ses_lock);
2748         spin_unlock(&tcp_srv->srv_lock);
2749
2750         spin_unlock(&cifs_tcp_ses_lock);
2751         cifs_put_tlink(tlink);
2752         return rc;
2753 }
2754
2755 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2756 static struct lock_class_key cifs_key[2];
2757 static struct lock_class_key cifs_slock_key[2];
2758
2759 static inline void
2760 cifs_reclassify_socket4(struct socket *sock)
2761 {
2762         struct sock *sk = sock->sk;
2763         BUG_ON(!sock_allow_reclassification(sk));
2764         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2765                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2766 }
2767
2768 static inline void
2769 cifs_reclassify_socket6(struct socket *sock)
2770 {
2771         struct sock *sk = sock->sk;
2772         BUG_ON(!sock_allow_reclassification(sk));
2773         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2774                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2775 }
2776 #else
2777 static inline void
2778 cifs_reclassify_socket4(struct socket *sock)
2779 {
2780 }
2781
2782 static inline void
2783 cifs_reclassify_socket6(struct socket *sock)
2784 {
2785 }
2786 #endif
2787
2788 /* See RFC1001 section 14 on representation of Netbios names */
2789 static void rfc1002mangle(char *target, char *source, unsigned int length)
2790 {
2791         unsigned int i, j;
2792
2793         for (i = 0, j = 0; i < (length); i++) {
2794                 /* mask a nibble at a time and encode */
2795                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2796                 target[j+1] = 'A' + (0x0F & source[i]);
2797                 j += 2;
2798         }
2799
2800 }
2801
2802 static int
2803 bind_socket(struct TCP_Server_Info *server)
2804 {
2805         int rc = 0;
2806         if (server->srcaddr.ss_family != AF_UNSPEC) {
2807                 /* Bind to the specified local IP address */
2808                 struct socket *socket = server->ssocket;
2809                 rc = socket->ops->bind(socket,
2810                                        (struct sockaddr *) &server->srcaddr,
2811                                        sizeof(server->srcaddr));
2812                 if (rc < 0) {
2813                         struct sockaddr_in *saddr4;
2814                         struct sockaddr_in6 *saddr6;
2815                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2816                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2817                         if (saddr6->sin6_family == AF_INET6)
2818                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2819                                          &saddr6->sin6_addr, rc);
2820                         else
2821                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2822                                          &saddr4->sin_addr.s_addr, rc);
2823                 }
2824         }
2825         return rc;
2826 }
2827
2828 static int
2829 ip_rfc1001_connect(struct TCP_Server_Info *server)
2830 {
2831         int rc = 0;
2832         /*
2833          * some servers require RFC1001 sessinit before sending
2834          * negprot - BB check reconnection in case where second
2835          * sessinit is sent but no second negprot
2836          */
2837         struct rfc1002_session_packet *ses_init_buf;
2838         unsigned int req_noscope_len;
2839         struct smb_hdr *smb_buf;
2840
2841         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2842                                GFP_KERNEL);
2843
2844         if (ses_init_buf) {
2845                 ses_init_buf->trailer.session_req.called_len = 32;
2846
2847                 if (server->server_RFC1001_name[0] != 0)
2848                         rfc1002mangle(ses_init_buf->trailer.
2849                                       session_req.called_name,
2850                                       server->server_RFC1001_name,
2851                                       RFC1001_NAME_LEN_WITH_NULL);
2852                 else
2853                         rfc1002mangle(ses_init_buf->trailer.
2854                                       session_req.called_name,
2855                                       DEFAULT_CIFS_CALLED_NAME,
2856                                       RFC1001_NAME_LEN_WITH_NULL);
2857
2858                 ses_init_buf->trailer.session_req.calling_len = 32;
2859
2860                 /*
2861                  * calling name ends in null (byte 16) from old smb
2862                  * convention.
2863                  */
2864                 if (server->workstation_RFC1001_name[0] != 0)
2865                         rfc1002mangle(ses_init_buf->trailer.
2866                                       session_req.calling_name,
2867                                       server->workstation_RFC1001_name,
2868                                       RFC1001_NAME_LEN_WITH_NULL);
2869                 else
2870                         rfc1002mangle(ses_init_buf->trailer.
2871                                       session_req.calling_name,
2872                                       "LINUX_CIFS_CLNT",
2873                                       RFC1001_NAME_LEN_WITH_NULL);
2874
2875                 ses_init_buf->trailer.session_req.scope1 = 0;
2876                 ses_init_buf->trailer.session_req.scope2 = 0;
2877                 smb_buf = (struct smb_hdr *)ses_init_buf;
2878
2879                 /* sizeof RFC1002_SESSION_REQUEST with no scopes */
2880                 req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
2881
2882                 /* == cpu_to_be32(0x81000044) */
2883                 smb_buf->smb_buf_length =
2884                         cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
2885                 rc = smb_send(server, smb_buf, 0x44);
2886                 kfree(ses_init_buf);
2887                 /*
2888                  * RFC1001 layer in at least one server
2889                  * requires very short break before negprot
2890                  * presumably because not expecting negprot
2891                  * to follow so fast.  This is a simple
2892                  * solution that works without
2893                  * complicating the code and causes no
2894                  * significant slowing down on mount
2895                  * for everyone else
2896                  */
2897                 usleep_range(1000, 2000);
2898         }
2899         /*
2900          * else the negprot may still work without this
2901          * even though malloc failed
2902          */
2903
2904         return rc;
2905 }
2906
2907 static int
2908 generic_ip_connect(struct TCP_Server_Info *server)
2909 {
2910         int rc = 0;
2911         __be16 sport;
2912         int slen, sfamily;
2913         struct socket *socket = server->ssocket;
2914         struct sockaddr *saddr;
2915
2916         saddr = (struct sockaddr *) &server->dstaddr;
2917
2918         if (server->dstaddr.ss_family == AF_INET6) {
2919                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2920
2921                 sport = ipv6->sin6_port;
2922                 slen = sizeof(struct sockaddr_in6);
2923                 sfamily = AF_INET6;
2924                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2925                                 ntohs(sport));
2926         } else {
2927                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2928
2929                 sport = ipv4->sin_port;
2930                 slen = sizeof(struct sockaddr_in);
2931                 sfamily = AF_INET;
2932                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2933                                 ntohs(sport));
2934         }
2935
2936         if (socket == NULL) {
2937                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2938                                    IPPROTO_TCP, &socket, 1);
2939                 if (rc < 0) {
2940                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2941                         server->ssocket = NULL;
2942                         return rc;
2943                 }
2944
2945                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2946                 cifs_dbg(FYI, "Socket created\n");
2947                 server->ssocket = socket;
2948                 socket->sk->sk_allocation = GFP_NOFS;
2949                 if (sfamily == AF_INET6)
2950                         cifs_reclassify_socket6(socket);
2951                 else
2952                         cifs_reclassify_socket4(socket);
2953         }
2954
2955         rc = bind_socket(server);
2956         if (rc < 0)
2957                 return rc;
2958
2959         /*
2960          * Eventually check for other socket options to change from
2961          * the default. sock_setsockopt not used because it expects
2962          * user space buffer
2963          */
2964         socket->sk->sk_rcvtimeo = 7 * HZ;
2965         socket->sk->sk_sndtimeo = 5 * HZ;
2966
2967         /* make the bufsizes depend on wsize/rsize and max requests */
2968         if (server->noautotune) {
2969                 if (socket->sk->sk_sndbuf < (200 * 1024))
2970                         socket->sk->sk_sndbuf = 200 * 1024;
2971                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2972                         socket->sk->sk_rcvbuf = 140 * 1024;
2973         }
2974
2975         if (server->tcp_nodelay)
2976                 tcp_sock_set_nodelay(socket->sk);
2977
2978         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2979                  socket->sk->sk_sndbuf,
2980                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2981
2982         rc = socket->ops->connect(socket, saddr, slen,
2983                                   server->noblockcnt ? O_NONBLOCK : 0);
2984         /*
2985          * When mounting SMB root file systems, we do not want to block in
2986          * connect. Otherwise bail out and then let cifs_reconnect() perform
2987          * reconnect failover - if possible.
2988          */
2989         if (server->noblockcnt && rc == -EINPROGRESS)
2990                 rc = 0;
2991         if (rc < 0) {
2992                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2993                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2994                 sock_release(socket);
2995                 server->ssocket = NULL;
2996                 return rc;
2997         }
2998         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2999         if (sport == htons(RFC1001_PORT))
3000                 rc = ip_rfc1001_connect(server);
3001
3002         return rc;
3003 }
3004
3005 static int
3006 ip_connect(struct TCP_Server_Info *server)
3007 {
3008         __be16 *sport;
3009         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3010         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3011
3012         if (server->dstaddr.ss_family == AF_INET6)
3013                 sport = &addr6->sin6_port;
3014         else
3015                 sport = &addr->sin_port;
3016
3017         if (*sport == 0) {
3018                 int rc;
3019
3020                 /* try with 445 port at first */
3021                 *sport = htons(CIFS_PORT);
3022
3023                 rc = generic_ip_connect(server);
3024                 if (rc >= 0)
3025                         return rc;
3026
3027                 /* if it failed, try with 139 port */
3028                 *sport = htons(RFC1001_PORT);
3029         }
3030
3031         return generic_ip_connect(server);
3032 }
3033
3034 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3035 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3036                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3037 {
3038         /*
3039          * If we are reconnecting then should we check to see if
3040          * any requested capabilities changed locally e.g. via
3041          * remount but we can not do much about it here
3042          * if they have (even if we could detect it by the following)
3043          * Perhaps we could add a backpointer to array of sb from tcon
3044          * or if we change to make all sb to same share the same
3045          * sb as NFS - then we only have one backpointer to sb.
3046          * What if we wanted to mount the server share twice once with
3047          * and once without posixacls or posix paths?
3048          */
3049         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3050
3051         if (ctx && ctx->no_linux_ext) {
3052                 tcon->fsUnixInfo.Capability = 0;
3053                 tcon->unix_ext = 0; /* Unix Extensions disabled */
3054                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3055                 return;
3056         } else if (ctx)
3057                 tcon->unix_ext = 1; /* Unix Extensions supported */
3058
3059         if (!tcon->unix_ext) {
3060                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3061                 return;
3062         }
3063
3064         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3065                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3066                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3067                 /*
3068                  * check for reconnect case in which we do not
3069                  * want to change the mount behavior if we can avoid it
3070                  */
3071                 if (ctx == NULL) {
3072                         /*
3073                          * turn off POSIX ACL and PATHNAMES if not set
3074                          * originally at mount time
3075                          */
3076                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3077                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3078                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3079                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3080                                         cifs_dbg(VFS, "POSIXPATH support change\n");
3081                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3082                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3083                                 cifs_dbg(VFS, "possible reconnect error\n");
3084                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
3085                         }
3086                 }
3087
3088                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3089                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
3090
3091                 cap &= CIFS_UNIX_CAP_MASK;
3092                 if (ctx && ctx->no_psx_acl)
3093                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3094                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3095                         cifs_dbg(FYI, "negotiated posix acl support\n");
3096                         if (cifs_sb)
3097                                 cifs_sb->mnt_cifs_flags |=
3098                                         CIFS_MOUNT_POSIXACL;
3099                 }
3100
3101                 if (ctx && ctx->posix_paths == 0)
3102                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3103                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3104                         cifs_dbg(FYI, "negotiate posix pathnames\n");
3105                         if (cifs_sb)
3106                                 cifs_sb->mnt_cifs_flags |=
3107                                         CIFS_MOUNT_POSIX_PATHS;
3108                 }
3109
3110                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3111 #ifdef CONFIG_CIFS_DEBUG2
3112                 if (cap & CIFS_UNIX_FCNTL_CAP)
3113                         cifs_dbg(FYI, "FCNTL cap\n");
3114                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3115                         cifs_dbg(FYI, "EXTATTR cap\n");
3116                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3117                         cifs_dbg(FYI, "POSIX path cap\n");
3118                 if (cap & CIFS_UNIX_XATTR_CAP)
3119                         cifs_dbg(FYI, "XATTR cap\n");
3120                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3121                         cifs_dbg(FYI, "POSIX ACL cap\n");
3122                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3123                         cifs_dbg(FYI, "very large read cap\n");
3124                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3125                         cifs_dbg(FYI, "very large write cap\n");
3126                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3127                         cifs_dbg(FYI, "transport encryption cap\n");
3128                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3129                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3130 #endif /* CIFS_DEBUG2 */
3131                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3132                         if (ctx == NULL)
3133                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3134                         else
3135                                 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");
3136
3137                 }
3138         }
3139 }
3140 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3141
3142 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3143 {
3144         struct smb3_fs_context *ctx = cifs_sb->ctx;
3145
3146         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3147
3148         spin_lock_init(&cifs_sb->tlink_tree_lock);
3149         cifs_sb->tlink_tree = RB_ROOT;
3150
3151         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3152                  ctx->file_mode, ctx->dir_mode);
3153
3154         /* this is needed for ASCII cp to Unicode converts */
3155         if (ctx->iocharset == NULL) {
3156                 /* load_nls_default cannot return null */
3157                 cifs_sb->local_nls = load_nls_default();
3158         } else {
3159                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3160                 if (cifs_sb->local_nls == NULL) {
3161                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3162                                  ctx->iocharset);
3163                         return -ELIBACC;
3164                 }
3165         }
3166         ctx->local_nls = cifs_sb->local_nls;
3167
3168         smb3_update_mnt_flags(cifs_sb);
3169
3170         if (ctx->direct_io)
3171                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3172         if (ctx->cache_ro) {
3173                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3174                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3175         } else if (ctx->cache_rw) {
3176                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3177                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3178                                             CIFS_MOUNT_RW_CACHE);
3179         }
3180
3181         if ((ctx->cifs_acl) && (ctx->dynperm))
3182                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3183
3184         if (ctx->prepath) {
3185                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3186                 if (cifs_sb->prepath == NULL)
3187                         return -ENOMEM;
3188                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3189         }
3190
3191         return 0;
3192 }
3193
3194 /* Release all succeed connections */
3195 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
3196 {
3197         int rc = 0;
3198
3199         if (mnt_ctx->tcon)
3200                 cifs_put_tcon(mnt_ctx->tcon);
3201         else if (mnt_ctx->ses)
3202                 cifs_put_smb_ses(mnt_ctx->ses);
3203         else if (mnt_ctx->server)
3204                 cifs_put_tcp_session(mnt_ctx->server, 0);
3205         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3206         free_xid(mnt_ctx->xid);
3207 }
3208
3209 /* Get connections for tcp, ses and tcon */
3210 static int mount_get_conns(struct mount_ctx *mnt_ctx)
3211 {
3212         int rc = 0;
3213         struct TCP_Server_Info *server = NULL;
3214         struct cifs_ses *ses = NULL;
3215         struct cifs_tcon *tcon = NULL;
3216         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3217         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3218         unsigned int xid;
3219
3220         xid = get_xid();
3221
3222         /* get a reference to a tcp session */
3223         server = cifs_get_tcp_session(ctx, NULL);
3224         if (IS_ERR(server)) {
3225                 rc = PTR_ERR(server);
3226                 server = NULL;
3227                 goto out;
3228         }
3229
3230         /* get a reference to a SMB session */
3231         ses = cifs_get_smb_ses(server, ctx);
3232         if (IS_ERR(ses)) {
3233                 rc = PTR_ERR(ses);
3234                 ses = NULL;
3235                 goto out;
3236         }
3237
3238         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3239                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3240                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3241                 rc = -EOPNOTSUPP;
3242                 goto out;
3243         }
3244
3245         /* search for existing tcon to this server share */
3246         tcon = cifs_get_tcon(ses, ctx);
3247         if (IS_ERR(tcon)) {
3248                 rc = PTR_ERR(tcon);
3249                 tcon = NULL;
3250                 goto out;
3251         }
3252
3253         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3254         if (tcon->posix_extensions)
3255                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3256
3257 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3258         /* tell server which Unix caps we support */
3259         if (cap_unix(tcon->ses)) {
3260                 /*
3261                  * reset of caps checks mount to see if unix extensions disabled
3262                  * for just this mount.
3263                  */
3264                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3265                 spin_lock(&tcon->ses->server->srv_lock);
3266                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3267                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3268                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3269                         spin_unlock(&tcon->ses->server->srv_lock);
3270                         rc = -EACCES;
3271                         goto out;
3272                 }
3273                 spin_unlock(&tcon->ses->server->srv_lock);
3274         } else
3275 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3276                 tcon->unix_ext = 0; /* server does not support them */
3277
3278         /* do not care if a following call succeed - informational */
3279         if (!tcon->pipe && server->ops->qfs_tcon) {
3280                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3281                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3282                         if (tcon->fsDevInfo.DeviceCharacteristics &
3283                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3284                                 cifs_dbg(VFS, "mounted to read only share\n");
3285                         else if ((cifs_sb->mnt_cifs_flags &
3286                                   CIFS_MOUNT_RW_CACHE) == 0)
3287                                 cifs_dbg(VFS, "read only mount of RW share\n");
3288                         /* no need to log a RW mount of a typical RW share */
3289                 }
3290         }
3291
3292         /*
3293          * Clamp the rsize/wsize mount arguments if they are too big for the server
3294          * and set the rsize/wsize to the negotiated values if not passed in by
3295          * the user on mount
3296          */
3297         if ((cifs_sb->ctx->wsize == 0) ||
3298             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3299                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3300         if ((cifs_sb->ctx->rsize == 0) ||
3301             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3302                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3303
3304         /*
3305          * The cookie is initialized from volume info returned above.
3306          * Inside cifs_fscache_get_super_cookie it checks
3307          * that we do not get super cookie twice.
3308          */
3309         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3310                 cifs_fscache_get_super_cookie(tcon);
3311
3312 out:
3313         mnt_ctx->server = server;
3314         mnt_ctx->ses = ses;
3315         mnt_ctx->tcon = tcon;
3316         mnt_ctx->xid = xid;
3317
3318         return rc;
3319 }
3320
3321 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3322                              struct cifs_tcon *tcon)
3323 {
3324         struct tcon_link *tlink;
3325
3326         /* hang the tcon off of the superblock */
3327         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3328         if (tlink == NULL)
3329                 return -ENOMEM;
3330
3331         tlink->tl_uid = ses->linux_uid;
3332         tlink->tl_tcon = tcon;
3333         tlink->tl_time = jiffies;
3334         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3335         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3336
3337         cifs_sb->master_tlink = tlink;
3338         spin_lock(&cifs_sb->tlink_tree_lock);
3339         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3340         spin_unlock(&cifs_sb->tlink_tree_lock);
3341
3342         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3343                                 TLINK_IDLE_EXPIRE);
3344         return 0;
3345 }
3346
3347 #ifdef CONFIG_CIFS_DFS_UPCALL
3348 /* Get unique dfs connections */
3349 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3350 {
3351         int rc;
3352
3353         mnt_ctx->fs_ctx->nosharesock = true;
3354         rc = mount_get_conns(mnt_ctx);
3355         if (mnt_ctx->server) {
3356                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3357                 spin_lock(&mnt_ctx->server->srv_lock);
3358                 mnt_ctx->server->is_dfs_conn = true;
3359                 spin_unlock(&mnt_ctx->server->srv_lock);
3360         }
3361         return rc;
3362 }
3363
3364 /*
3365  * cifs_build_path_to_root returns full path to root when we do not have an
3366  * existing connection (tcon)
3367  */
3368 static char *
3369 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3370                        const struct cifs_sb_info *cifs_sb, bool useppath)
3371 {
3372         char *full_path, *pos;
3373         unsigned int pplen = useppath && ctx->prepath ?
3374                 strlen(ctx->prepath) + 1 : 0;
3375         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3376
3377         if (unc_len > MAX_TREE_SIZE)
3378                 return ERR_PTR(-EINVAL);
3379
3380         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3381         if (full_path == NULL)
3382                 return ERR_PTR(-ENOMEM);
3383
3384         memcpy(full_path, ctx->UNC, unc_len);
3385         pos = full_path + unc_len;
3386
3387         if (pplen) {
3388                 *pos = CIFS_DIR_SEP(cifs_sb);
3389                 memcpy(pos + 1, ctx->prepath, pplen);
3390                 pos += pplen;
3391         }
3392
3393         *pos = '\0'; /* add trailing null */
3394         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3395         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3396         return full_path;
3397 }
3398
3399 /*
3400  * expand_dfs_referral - Update cifs_sb from dfs referral path
3401  *
3402  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3403  * submount.  Otherwise it will be left untouched.
3404  */
3405 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3406                                struct dfs_info3_param *referral)
3407 {
3408         int rc;
3409         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3410         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3411         char *fake_devname = NULL, *mdata = NULL;
3412
3413         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3414                                            &fake_devname);
3415         if (IS_ERR(mdata)) {
3416                 rc = PTR_ERR(mdata);
3417                 mdata = NULL;
3418         } else {
3419                 /*
3420                  * We can not clear out the whole structure since we no longer have an explicit
3421                  * function to parse a mount-string. Instead we need to clear out the individual
3422                  * fields that are no longer valid.
3423                  */
3424                 kfree(ctx->prepath);
3425                 ctx->prepath = NULL;
3426                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3427         }
3428         kfree(fake_devname);
3429         kfree(cifs_sb->ctx->mount_options);
3430         cifs_sb->ctx->mount_options = mdata;
3431
3432         return rc;
3433 }
3434 #endif
3435
3436 /* TODO: all callers to this are broken. We are not parsing mount_options here
3437  * we should pass a clone of the original context?
3438  */
3439 int
3440 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3441 {
3442         int rc;
3443
3444         if (devname) {
3445                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3446                 rc = smb3_parse_devname(devname, ctx);
3447                 if (rc) {
3448                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3449                         return rc;
3450                 }
3451         }
3452
3453         if (mntopts) {
3454                 char *ip;
3455
3456                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3457                 if (rc) {
3458                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3459                         return rc;
3460                 }
3461
3462                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3463                 kfree(ip);
3464                 if (!rc) {
3465                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3466                         return -EINVAL;
3467                 }
3468         }
3469
3470         if (ctx->nullauth) {
3471                 cifs_dbg(FYI, "Anonymous login\n");
3472                 kfree(ctx->username);
3473                 ctx->username = NULL;
3474         } else if (ctx->username) {
3475                 /* BB fixme parse for domain name here */
3476                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3477         } else {
3478                 cifs_dbg(VFS, "No username specified\n");
3479         /* In userspace mount helper we can get user name from alternate
3480            locations such as env variables and files on disk */
3481                 return -EINVAL;
3482         }
3483
3484         return 0;
3485 }
3486
3487 static int
3488 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3489                                         unsigned int xid,
3490                                         struct cifs_tcon *tcon,
3491                                         struct cifs_sb_info *cifs_sb,
3492                                         char *full_path,
3493                                         int added_treename)
3494 {
3495         int rc;
3496         char *s;
3497         char sep, tmp;
3498         int skip = added_treename ? 1 : 0;
3499
3500         sep = CIFS_DIR_SEP(cifs_sb);
3501         s = full_path;
3502
3503         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3504         while (rc == 0) {
3505                 /* skip separators */
3506                 while (*s == sep)
3507                         s++;
3508                 if (!*s)
3509                         break;
3510                 /* next separator */
3511                 while (*s && *s != sep)
3512                         s++;
3513                 /*
3514                  * if the treename is added, we then have to skip the first
3515                  * part within the separators
3516                  */
3517                 if (skip) {
3518                         skip = 0;
3519                         continue;
3520                 }
3521                 /*
3522                  * temporarily null-terminate the path at the end of
3523                  * the current component
3524                  */
3525                 tmp = *s;
3526                 *s = 0;
3527                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3528                                                      full_path);
3529                 *s = tmp;
3530         }
3531         return rc;
3532 }
3533
3534 /*
3535  * Check if path is remote (i.e. a DFS share).
3536  *
3537  * Return -EREMOTE if it is, otherwise 0 or -errno.
3538  */
3539 static int is_path_remote(struct mount_ctx *mnt_ctx)
3540 {
3541         int rc;
3542         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3543         struct TCP_Server_Info *server = mnt_ctx->server;
3544         unsigned int xid = mnt_ctx->xid;
3545         struct cifs_tcon *tcon = mnt_ctx->tcon;
3546         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3547         char *full_path;
3548 #ifdef CONFIG_CIFS_DFS_UPCALL
3549         bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
3550 #endif
3551
3552         if (!server->ops->is_path_accessible)
3553                 return -EOPNOTSUPP;
3554
3555         /*
3556          * cifs_build_path_to_root works only when we have a valid tcon
3557          */
3558         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3559                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3560         if (full_path == NULL)
3561                 return -ENOMEM;
3562
3563         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3564
3565         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3566                                              full_path);
3567 #ifdef CONFIG_CIFS_DFS_UPCALL
3568         if (nodfs) {
3569                 if (rc == -EREMOTE)
3570                         rc = -EOPNOTSUPP;
3571                 goto out;
3572         }
3573
3574         /* path *might* exist with non-ASCII characters in DFS root
3575          * try again with full path (only if nodfs is not set) */
3576         if (rc == -ENOENT && is_tcon_dfs(tcon))
3577                 rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
3578                                                         full_path);
3579 #endif
3580         if (rc != 0 && rc != -EREMOTE)
3581                 goto out;
3582
3583         if (rc != -EREMOTE) {
3584                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3585                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3586                 if (rc != 0) {
3587                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3588                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3589                         rc = 0;
3590                 }
3591         }
3592
3593 out:
3594         kfree(full_path);
3595         return rc;
3596 }
3597
3598 #ifdef CONFIG_CIFS_DFS_UPCALL
3599 static void set_root_ses(struct mount_ctx *mnt_ctx)
3600 {
3601         if (mnt_ctx->ses) {
3602                 spin_lock(&cifs_tcp_ses_lock);
3603                 mnt_ctx->ses->ses_count++;
3604                 spin_unlock(&cifs_tcp_ses_lock);
3605                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3606         }
3607         mnt_ctx->root_ses = mnt_ctx->ses;
3608 }
3609
3610 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3611 {
3612         int rc;
3613         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3614         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3615
3616         *isdfs = true;
3617
3618         rc = mount_get_conns(mnt_ctx);
3619         /*
3620          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3621          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3622          *
3623          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3624          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3625          */
3626         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3627             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3628                            ctx->UNC + 1, NULL, root_tl)) {
3629                 if (rc)
3630                         return rc;
3631                 /* Check if it is fully accessible and then mount it */
3632                 rc = is_path_remote(mnt_ctx);
3633                 if (!rc)
3634                         *isdfs = false;
3635                 else if (rc != -EREMOTE)
3636                         return rc;
3637         }
3638         return 0;
3639 }
3640
3641 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3642                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3643 {
3644         int rc;
3645         struct dfs_info3_param ref = {};
3646         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3647         char *oldmnt = cifs_sb->ctx->mount_options;
3648
3649         cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
3650                  dfs_cache_get_tgt_name(tit));
3651
3652         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3653         if (rc)
3654                 goto out;
3655
3656         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3657         if (rc)
3658                 goto out;
3659
3660         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3661         if (oldmnt != cifs_sb->ctx->mount_options) {
3662                 mount_put_conns(mnt_ctx);
3663                 rc = mount_get_dfs_conns(mnt_ctx);
3664         }
3665         if (!rc) {
3666                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3667                         set_root_ses(mnt_ctx);
3668                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3669                                               cifs_remap(cifs_sb), ref_path, tit);
3670         }
3671
3672 out:
3673         free_dfs_info_param(&ref);
3674         return rc;
3675 }
3676
3677 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3678 {
3679         int rc;
3680         char *full_path;
3681         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3682         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3683         struct dfs_cache_tgt_iterator *tit;
3684
3685         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3686          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3687          * now on.
3688          */
3689         mount_put_conns(mnt_ctx);
3690         mount_get_dfs_conns(mnt_ctx);
3691         set_root_ses(mnt_ctx);
3692
3693         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3694         if (IS_ERR(full_path))
3695                 return PTR_ERR(full_path);
3696
3697         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3698                                                             cifs_remap(cifs_sb));
3699         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3700                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3701                 mnt_ctx->origin_fullpath = NULL;
3702                 goto out;
3703         }
3704
3705         /* Try all dfs root targets */
3706         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3707              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3708                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3709                 if (!rc) {
3710                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3711                         if (!mnt_ctx->leaf_fullpath)
3712                                 rc = -ENOMEM;
3713                         break;
3714                 }
3715         }
3716
3717 out:
3718         kfree(full_path);
3719         return rc;
3720 }
3721
3722 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3723 {
3724         int rc;
3725         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3726         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3727         char *full_path;
3728         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3729         struct dfs_cache_tgt_iterator *tit;
3730
3731         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3732         if (IS_ERR(full_path))
3733                 return PTR_ERR(full_path);
3734
3735         kfree(mnt_ctx->leaf_fullpath);
3736         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3737                                                           cifs_remap(cifs_sb));
3738         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3739                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3740                 mnt_ctx->leaf_fullpath = NULL;
3741                 goto out;
3742         }
3743
3744         /* Get referral from dfs link */
3745         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3746                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3747         if (rc)
3748                 goto out;
3749
3750         /* Try all dfs link targets.  If an I/O fails from currently connected DFS target with an
3751          * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
3752          * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
3753          * STATUS_PATH_NOT_COVERED."
3754          */
3755         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3756              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3757                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3758                 if (!rc) {
3759                         rc = is_path_remote(mnt_ctx);
3760                         if (!rc || rc == -EREMOTE)
3761                                 break;
3762                 }
3763         }
3764
3765 out:
3766         kfree(full_path);
3767         dfs_cache_free_tgts(&tl);
3768         return rc;
3769 }
3770
3771 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3772 {
3773         int rc;
3774         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3775         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3776         char *full_path;
3777         int num_links = 0;
3778
3779         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3780         if (IS_ERR(full_path))
3781                 return PTR_ERR(full_path);
3782
3783         kfree(mnt_ctx->origin_fullpath);
3784         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3785                                                             cifs_remap(cifs_sb));
3786         kfree(full_path);
3787
3788         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3789                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3790                 mnt_ctx->origin_fullpath = NULL;
3791                 return rc;
3792         }
3793
3794         do {
3795                 rc = __follow_dfs_link(mnt_ctx);
3796                 if (!rc || rc != -EREMOTE)
3797                         break;
3798         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3799
3800         return rc;
3801 }
3802
3803 /* Set up DFS referral paths for failover */
3804 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3805 {
3806         struct TCP_Server_Info *server = mnt_ctx->server;
3807
3808         mutex_lock(&server->refpath_lock);
3809         server->origin_fullpath = mnt_ctx->origin_fullpath;
3810         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3811         server->current_fullpath = mnt_ctx->leaf_fullpath;
3812         mutex_unlock(&server->refpath_lock);
3813         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3814 }
3815
3816 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3817 {
3818         int rc;
3819         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3820         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3821         bool isdfs;
3822
3823         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3824         if (rc)
3825                 goto error;
3826         if (!isdfs)
3827                 goto out;
3828
3829         /* proceed as DFS mount */
3830         uuid_gen(&mnt_ctx.mount_id);
3831         rc = connect_dfs_root(&mnt_ctx, &tl);
3832         dfs_cache_free_tgts(&tl);
3833
3834         if (rc)
3835                 goto error;
3836
3837         rc = is_path_remote(&mnt_ctx);
3838         if (rc)
3839                 rc = follow_dfs_link(&mnt_ctx);
3840         if (rc)
3841                 goto error;
3842
3843         setup_server_referral_paths(&mnt_ctx);
3844         /*
3845          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3846          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3847          */
3848         cifs_autodisable_serverino(cifs_sb);
3849         /*
3850          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3851          * that have different prefix paths.
3852          */
3853         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3854         kfree(cifs_sb->prepath);
3855         cifs_sb->prepath = ctx->prepath;
3856         ctx->prepath = NULL;
3857         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3858
3859 out:
3860         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3861         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3862         if (rc)
3863                 goto error;
3864
3865         free_xid(mnt_ctx.xid);
3866         return rc;
3867
3868 error:
3869         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3870         kfree(mnt_ctx.origin_fullpath);
3871         kfree(mnt_ctx.leaf_fullpath);
3872         mount_put_conns(&mnt_ctx);
3873         return rc;
3874 }
3875 #else
3876 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3877 {
3878         int rc = 0;
3879         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3880
3881         rc = mount_get_conns(&mnt_ctx);
3882         if (rc)
3883                 goto error;
3884
3885         if (mnt_ctx.tcon) {
3886                 rc = is_path_remote(&mnt_ctx);
3887                 if (rc == -EREMOTE)
3888                         rc = -EOPNOTSUPP;
3889                 if (rc)
3890                         goto error;
3891         }
3892
3893         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3894         if (rc)
3895                 goto error;
3896
3897         free_xid(mnt_ctx.xid);
3898         return rc;
3899
3900 error:
3901         mount_put_conns(&mnt_ctx);
3902         return rc;
3903 }
3904 #endif
3905
3906 /*
3907  * Issue a TREE_CONNECT request.
3908  */
3909 int
3910 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3911          const char *tree, struct cifs_tcon *tcon,
3912          const struct nls_table *nls_codepage)
3913 {
3914         struct smb_hdr *smb_buffer;
3915         struct smb_hdr *smb_buffer_response;
3916         TCONX_REQ *pSMB;
3917         TCONX_RSP *pSMBr;
3918         unsigned char *bcc_ptr;
3919         int rc = 0;
3920         int length;
3921         __u16 bytes_left, count;
3922
3923         if (ses == NULL)
3924                 return -EIO;
3925
3926         smb_buffer = cifs_buf_get();
3927         if (smb_buffer == NULL)
3928                 return -ENOMEM;
3929
3930         smb_buffer_response = smb_buffer;
3931
3932         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3933                         NULL /*no tid */ , 4 /*wct */ );
3934
3935         smb_buffer->Mid = get_next_mid(ses->server);
3936         smb_buffer->Uid = ses->Suid;
3937         pSMB = (TCONX_REQ *) smb_buffer;
3938         pSMBr = (TCONX_RSP *) smb_buffer_response;
3939
3940         pSMB->AndXCommand = 0xFF;
3941         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3942         bcc_ptr = &pSMB->Password[0];
3943
3944         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3945         *bcc_ptr = 0; /* password is null byte */
3946         bcc_ptr++;              /* skip password */
3947         /* already aligned so no need to do it below */
3948
3949         if (ses->server->sign)
3950                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3951
3952         if (ses->capabilities & CAP_STATUS32) {
3953                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3954         }
3955         if (ses->capabilities & CAP_DFS) {
3956                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3957         }
3958         if (ses->capabilities & CAP_UNICODE) {
3959                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3960                 length =
3961                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3962                         6 /* max utf8 char length in bytes */ *
3963                         (/* server len*/ + 256 /* share len */), nls_codepage);
3964                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3965                 bcc_ptr += 2;   /* skip trailing null */
3966         } else {                /* ASCII */
3967                 strcpy(bcc_ptr, tree);
3968                 bcc_ptr += strlen(tree) + 1;
3969         }
3970         strcpy(bcc_ptr, "?????");
3971         bcc_ptr += strlen("?????");
3972         bcc_ptr += 1;
3973         count = bcc_ptr - &pSMB->Password[0];
3974         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3975         pSMB->ByteCount = cpu_to_le16(count);
3976
3977         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3978                          0);
3979
3980         /* above now done in SendReceive */
3981         if (rc == 0) {
3982                 bool is_unicode;
3983
3984                 tcon->tid = smb_buffer_response->Tid;
3985                 bcc_ptr = pByteArea(smb_buffer_response);
3986                 bytes_left = get_bcc(smb_buffer_response);
3987                 length = strnlen(bcc_ptr, bytes_left - 2);
3988                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3989                         is_unicode = true;
3990                 else
3991                         is_unicode = false;
3992
3993
3994                 /* skip service field (NB: this field is always ASCII) */
3995                 if (length == 3) {
3996                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3997                             (bcc_ptr[2] == 'C')) {
3998                                 cifs_dbg(FYI, "IPC connection\n");
3999                                 tcon->ipc = true;
4000                                 tcon->pipe = true;
4001                         }
4002                 } else if (length == 2) {
4003                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
4004                                 /* the most common case */
4005                                 cifs_dbg(FYI, "disk share connection\n");
4006                         }
4007                 }
4008                 bcc_ptr += length + 1;
4009                 bytes_left -= (length + 1);
4010                 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
4011
4012                 /* mostly informational -- no need to fail on error here */
4013                 kfree(tcon->nativeFileSystem);
4014                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
4015                                                       bytes_left, is_unicode,
4016                                                       nls_codepage);
4017
4018                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
4019
4020                 if ((smb_buffer_response->WordCount == 3) ||
4021                          (smb_buffer_response->WordCount == 7))
4022                         /* field is in same location */
4023                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
4024                 else
4025                         tcon->Flags = 0;
4026                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
4027         }
4028
4029         cifs_buf_release(smb_buffer);
4030         return rc;
4031 }
4032
4033 static void delayed_free(struct rcu_head *p)
4034 {
4035         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
4036
4037         unload_nls(cifs_sb->local_nls);
4038         smb3_cleanup_fs_context(cifs_sb->ctx);
4039         kfree(cifs_sb);
4040 }
4041
4042 void
4043 cifs_umount(struct cifs_sb_info *cifs_sb)
4044 {
4045         struct rb_root *root = &cifs_sb->tlink_tree;
4046         struct rb_node *node;
4047         struct tcon_link *tlink;
4048
4049         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
4050
4051         spin_lock(&cifs_sb->tlink_tree_lock);
4052         while ((node = rb_first(root))) {
4053                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4054                 cifs_get_tlink(tlink);
4055                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4056                 rb_erase(node, root);
4057
4058                 spin_unlock(&cifs_sb->tlink_tree_lock);
4059                 cifs_put_tlink(tlink);
4060                 spin_lock(&cifs_sb->tlink_tree_lock);
4061         }
4062         spin_unlock(&cifs_sb->tlink_tree_lock);
4063
4064         kfree(cifs_sb->prepath);
4065 #ifdef CONFIG_CIFS_DFS_UPCALL
4066         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
4067 #endif
4068         call_rcu(&cifs_sb->rcu, delayed_free);
4069 }
4070
4071 int
4072 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
4073                         struct TCP_Server_Info *server)
4074 {
4075         int rc = 0;
4076
4077         if (!server->ops->need_neg || !server->ops->negotiate)
4078                 return -ENOSYS;
4079
4080         /* only send once per connect */
4081         spin_lock(&server->srv_lock);
4082         if (!server->ops->need_neg(server) ||
4083             server->tcpStatus != CifsNeedNegotiate) {
4084                 spin_unlock(&server->srv_lock);
4085                 return 0;
4086         }
4087         server->tcpStatus = CifsInNegotiate;
4088         spin_unlock(&server->srv_lock);
4089
4090         rc = server->ops->negotiate(xid, ses, server);
4091         if (rc == 0) {
4092                 spin_lock(&server->srv_lock);
4093                 if (server->tcpStatus == CifsInNegotiate)
4094                         server->tcpStatus = CifsGood;
4095                 else
4096                         rc = -EHOSTDOWN;
4097                 spin_unlock(&server->srv_lock);
4098         } else {
4099                 spin_lock(&server->srv_lock);
4100                 if (server->tcpStatus == CifsInNegotiate)
4101                         server->tcpStatus = CifsNeedNegotiate;
4102                 spin_unlock(&server->srv_lock);
4103         }
4104
4105         return rc;
4106 }
4107
4108 int
4109 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
4110                    struct TCP_Server_Info *server,
4111                    struct nls_table *nls_info)
4112 {
4113         int rc = -ENOSYS;
4114         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
4115         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
4116         bool is_binding = false;
4117
4118         spin_lock(&ses->ses_lock);
4119         if (server->dstaddr.ss_family == AF_INET6)
4120                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
4121         else
4122                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
4123
4124         if (ses->ses_status != SES_GOOD &&
4125             ses->ses_status != SES_NEW &&
4126             ses->ses_status != SES_NEED_RECON) {
4127                 spin_unlock(&ses->ses_lock);
4128                 return 0;
4129         }
4130
4131         /* only send once per connect */
4132         spin_lock(&ses->chan_lock);
4133         if (CIFS_ALL_CHANS_GOOD(ses) ||
4134             cifs_chan_in_reconnect(ses, server)) {
4135                 spin_unlock(&ses->chan_lock);
4136                 spin_unlock(&ses->ses_lock);
4137                 return 0;
4138         }
4139         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
4140         cifs_chan_set_in_reconnect(ses, server);
4141         spin_unlock(&ses->chan_lock);
4142
4143         if (!is_binding)
4144                 ses->ses_status = SES_IN_SETUP;
4145         spin_unlock(&ses->ses_lock);
4146
4147         if (!is_binding) {
4148                 ses->capabilities = server->capabilities;
4149                 if (!linuxExtEnabled)
4150                         ses->capabilities &= (~server->vals->cap_unix);
4151
4152                 if (ses->auth_key.response) {
4153                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
4154                                  ses->auth_key.response);
4155                         kfree_sensitive(ses->auth_key.response);
4156                         ses->auth_key.response = NULL;
4157                         ses->auth_key.len = 0;
4158                 }
4159         }
4160
4161         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
4162                  server->sec_mode, server->capabilities, server->timeAdj);
4163
4164         if (server->ops->sess_setup)
4165                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
4166
4167         if (rc) {
4168                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4169                 spin_lock(&ses->ses_lock);
4170                 if (ses->ses_status == SES_IN_SETUP)
4171                         ses->ses_status = SES_NEED_RECON;
4172                 spin_lock(&ses->chan_lock);
4173                 cifs_chan_clear_in_reconnect(ses, server);
4174                 spin_unlock(&ses->chan_lock);
4175                 spin_unlock(&ses->ses_lock);
4176         } else {
4177                 spin_lock(&ses->ses_lock);
4178                 if (ses->ses_status == SES_IN_SETUP)
4179                         ses->ses_status = SES_GOOD;
4180                 spin_lock(&ses->chan_lock);
4181                 cifs_chan_clear_in_reconnect(ses, server);
4182                 cifs_chan_clear_need_reconnect(ses, server);
4183                 spin_unlock(&ses->chan_lock);
4184                 spin_unlock(&ses->ses_lock);
4185         }
4186
4187         return rc;
4188 }
4189
4190 static int
4191 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4192 {
4193         ctx->sectype = ses->sectype;
4194
4195         /* krb5 is special, since we don't need username or pw */
4196         if (ctx->sectype == Kerberos)
4197                 return 0;
4198
4199         return cifs_set_cifscreds(ctx, ses);
4200 }
4201
4202 static struct cifs_tcon *
4203 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4204 {
4205         int rc;
4206         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4207         struct cifs_ses *ses;
4208         struct cifs_tcon *tcon = NULL;
4209         struct smb3_fs_context *ctx;
4210
4211         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4212         if (ctx == NULL)
4213                 return ERR_PTR(-ENOMEM);
4214
4215         ctx->local_nls = cifs_sb->local_nls;
4216         ctx->linux_uid = fsuid;
4217         ctx->cred_uid = fsuid;
4218         ctx->UNC = master_tcon->tree_name;
4219         ctx->retry = master_tcon->retry;
4220         ctx->nocase = master_tcon->nocase;
4221         ctx->nohandlecache = master_tcon->nohandlecache;
4222         ctx->local_lease = master_tcon->local_lease;
4223         ctx->no_lease = master_tcon->no_lease;
4224         ctx->resilient = master_tcon->use_resilient;
4225         ctx->persistent = master_tcon->use_persistent;
4226         ctx->handle_timeout = master_tcon->handle_timeout;
4227         ctx->no_linux_ext = !master_tcon->unix_ext;
4228         ctx->linux_ext = master_tcon->posix_extensions;
4229         ctx->sectype = master_tcon->ses->sectype;
4230         ctx->sign = master_tcon->ses->sign;
4231         ctx->seal = master_tcon->seal;
4232         ctx->witness = master_tcon->use_witness;
4233
4234         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4235         if (rc) {
4236                 tcon = ERR_PTR(rc);
4237                 goto out;
4238         }
4239
4240         /* get a reference for the same TCP session */
4241         spin_lock(&cifs_tcp_ses_lock);
4242         ++master_tcon->ses->server->srv_count;
4243         spin_unlock(&cifs_tcp_ses_lock);
4244
4245         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4246         if (IS_ERR(ses)) {
4247                 tcon = (struct cifs_tcon *)ses;
4248                 cifs_put_tcp_session(master_tcon->ses->server, 0);
4249                 goto out;
4250         }
4251
4252         tcon = cifs_get_tcon(ses, ctx);
4253         if (IS_ERR(tcon)) {
4254                 cifs_put_smb_ses(ses);
4255                 goto out;
4256         }
4257
4258 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
4259         if (cap_unix(ses))
4260                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4261 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
4262
4263 out:
4264         kfree(ctx->username);
4265         kfree_sensitive(ctx->password);
4266         kfree(ctx);
4267
4268         return tcon;
4269 }
4270
4271 struct cifs_tcon *
4272 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4273 {
4274         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4275 }
4276
4277 /* find and return a tlink with given uid */
4278 static struct tcon_link *
4279 tlink_rb_search(struct rb_root *root, kuid_t uid)
4280 {
4281         struct rb_node *node = root->rb_node;
4282         struct tcon_link *tlink;
4283
4284         while (node) {
4285                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4286
4287                 if (uid_gt(tlink->tl_uid, uid))
4288                         node = node->rb_left;
4289                 else if (uid_lt(tlink->tl_uid, uid))
4290                         node = node->rb_right;
4291                 else
4292                         return tlink;
4293         }
4294         return NULL;
4295 }
4296
4297 /* insert a tcon_link into the tree */
4298 static void
4299 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4300 {
4301         struct rb_node **new = &(root->rb_node), *parent = NULL;
4302         struct tcon_link *tlink;
4303
4304         while (*new) {
4305                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4306                 parent = *new;
4307
4308                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4309                         new = &((*new)->rb_left);
4310                 else
4311                         new = &((*new)->rb_right);
4312         }
4313
4314         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4315         rb_insert_color(&new_tlink->tl_rbnode, root);
4316 }
4317
4318 /*
4319  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4320  * current task.
4321  *
4322  * If the superblock doesn't refer to a multiuser mount, then just return
4323  * the master tcon for the mount.
4324  *
4325  * First, search the rbtree for an existing tcon for this fsuid. If one
4326  * exists, then check to see if it's pending construction. If it is then wait
4327  * for construction to complete. Once it's no longer pending, check to see if
4328  * it failed and either return an error or retry construction, depending on
4329  * the timeout.
4330  *
4331  * If one doesn't exist then insert a new tcon_link struct into the tree and
4332  * try to construct a new one.
4333  */
4334 struct tcon_link *
4335 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4336 {
4337         int ret;
4338         kuid_t fsuid = current_fsuid();
4339         struct tcon_link *tlink, *newtlink;
4340
4341         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4342                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4343
4344         spin_lock(&cifs_sb->tlink_tree_lock);
4345         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4346         if (tlink)
4347                 cifs_get_tlink(tlink);
4348         spin_unlock(&cifs_sb->tlink_tree_lock);
4349
4350         if (tlink == NULL) {
4351                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4352                 if (newtlink == NULL)
4353                         return ERR_PTR(-ENOMEM);
4354                 newtlink->tl_uid = fsuid;
4355                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4356                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4357                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4358                 cifs_get_tlink(newtlink);
4359
4360                 spin_lock(&cifs_sb->tlink_tree_lock);
4361                 /* was one inserted after previous search? */
4362                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4363                 if (tlink) {
4364                         cifs_get_tlink(tlink);
4365                         spin_unlock(&cifs_sb->tlink_tree_lock);
4366                         kfree(newtlink);
4367                         goto wait_for_construction;
4368                 }
4369                 tlink = newtlink;
4370                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4371                 spin_unlock(&cifs_sb->tlink_tree_lock);
4372         } else {
4373 wait_for_construction:
4374                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4375                                   TASK_INTERRUPTIBLE);
4376                 if (ret) {
4377                         cifs_put_tlink(tlink);
4378                         return ERR_PTR(-ERESTARTSYS);
4379                 }
4380
4381                 /* if it's good, return it */
4382                 if (!IS_ERR(tlink->tl_tcon))
4383                         return tlink;
4384
4385                 /* return error if we tried this already recently */
4386                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4387                         cifs_put_tlink(tlink);
4388                         return ERR_PTR(-EACCES);
4389                 }
4390
4391                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4392                         goto wait_for_construction;
4393         }
4394
4395         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4396         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4397         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4398
4399         if (IS_ERR(tlink->tl_tcon)) {
4400                 cifs_put_tlink(tlink);
4401                 return ERR_PTR(-EACCES);
4402         }
4403
4404         return tlink;
4405 }
4406
4407 /*
4408  * periodic workqueue job that scans tcon_tree for a superblock and closes
4409  * out tcons.
4410  */
4411 static void
4412 cifs_prune_tlinks(struct work_struct *work)
4413 {
4414         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4415                                                     prune_tlinks.work);
4416         struct rb_root *root = &cifs_sb->tlink_tree;
4417         struct rb_node *node;
4418         struct rb_node *tmp;
4419         struct tcon_link *tlink;
4420
4421         /*
4422          * Because we drop the spinlock in the loop in order to put the tlink
4423          * it's not guarded against removal of links from the tree. The only
4424          * places that remove entries from the tree are this function and
4425          * umounts. Because this function is non-reentrant and is canceled
4426          * before umount can proceed, this is safe.
4427          */
4428         spin_lock(&cifs_sb->tlink_tree_lock);
4429         node = rb_first(root);
4430         while (node != NULL) {
4431                 tmp = node;
4432                 node = rb_next(tmp);
4433                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4434
4435                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4436                     atomic_read(&tlink->tl_count) != 0 ||
4437                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4438                         continue;
4439
4440                 cifs_get_tlink(tlink);
4441                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4442                 rb_erase(tmp, root);
4443
4444                 spin_unlock(&cifs_sb->tlink_tree_lock);
4445                 cifs_put_tlink(tlink);
4446                 spin_lock(&cifs_sb->tlink_tree_lock);
4447         }
4448         spin_unlock(&cifs_sb->tlink_tree_lock);
4449
4450         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4451                                 TLINK_IDLE_EXPIRE);
4452 }
4453
4454 #ifdef CONFIG_CIFS_DFS_UPCALL
4455 /* Update dfs referral path of superblock */
4456 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4457                                   const char *target)
4458 {
4459         int rc = 0;
4460         size_t len = strlen(target);
4461         char *refpath, *npath;
4462
4463         if (unlikely(len < 2 || *target != '\\'))
4464                 return -EINVAL;
4465
4466         if (target[1] == '\\') {
4467                 len += 1;
4468                 refpath = kmalloc(len, GFP_KERNEL);
4469                 if (!refpath)
4470                         return -ENOMEM;
4471
4472                 scnprintf(refpath, len, "%s", target);
4473         } else {
4474                 len += sizeof("\\");
4475                 refpath = kmalloc(len, GFP_KERNEL);
4476                 if (!refpath)
4477                         return -ENOMEM;
4478
4479                 scnprintf(refpath, len, "\\%s", target);
4480         }
4481
4482         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4483         kfree(refpath);
4484
4485         if (IS_ERR(npath)) {
4486                 rc = PTR_ERR(npath);
4487         } else {
4488                 mutex_lock(&server->refpath_lock);
4489                 kfree(server->leaf_fullpath);
4490                 server->leaf_fullpath = npath;
4491                 mutex_unlock(&server->refpath_lock);
4492                 server->current_fullpath = server->leaf_fullpath;
4493         }
4494         return rc;
4495 }
4496
4497 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4498                                        size_t tcp_host_len, char *share, bool *target_match)
4499 {
4500         int rc = 0;
4501         const char *dfs_host;
4502         size_t dfs_host_len;
4503
4504         *target_match = true;
4505         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4506
4507         /* Check if hostnames or addresses match */
4508         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4509                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4510                          dfs_host, (int)tcp_host_len, tcp_host);
4511                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4512                 if (rc)
4513                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4514         }
4515         return rc;
4516 }
4517
4518 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4519                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4520                                      struct dfs_cache_tgt_list *tl)
4521 {
4522         int rc;
4523         struct TCP_Server_Info *server = tcon->ses->server;
4524         const struct smb_version_operations *ops = server->ops;
4525         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4526         char *share = NULL, *prefix = NULL;
4527         const char *tcp_host;
4528         size_t tcp_host_len;
4529         struct dfs_cache_tgt_iterator *tit;
4530         bool target_match;
4531
4532         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4533
4534         tit = dfs_cache_get_tgt_iterator(tl);
4535         if (!tit) {
4536                 rc = -ENOENT;
4537                 goto out;
4538         }
4539
4540         /* Try to tree connect to all dfs targets */
4541         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4542                 const char *target = dfs_cache_get_tgt_name(tit);
4543                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4544
4545                 kfree(share);
4546                 kfree(prefix);
4547                 share = prefix = NULL;
4548
4549                 /* Check if share matches with tcp ses */
4550                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4551                 if (rc) {
4552                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4553                         break;
4554                 }
4555
4556                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4557                                                  &target_match);
4558                 if (rc)
4559                         break;
4560                 if (!target_match) {
4561                         rc = -EHOSTUNREACH;
4562                         continue;
4563                 }
4564
4565                 if (ipc->need_reconnect) {
4566                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4567                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4568                         if (rc)
4569                                 break;
4570                 }
4571
4572                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4573                 if (!islink) {
4574                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4575                         break;
4576                 }
4577                 /*
4578                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4579                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4580                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4581                  * newly resolved target.
4582                  */
4583                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4584                                    NULL, &ntl)) {
4585                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4586                         if (rc)
4587                                 continue;
4588                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4589                         if (!rc)
4590                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4591                 } else {
4592                         /* Target is another dfs share */
4593                         rc = update_server_fullpath(server, cifs_sb, target);
4594                         dfs_cache_free_tgts(tl);
4595
4596                         if (!rc) {
4597                                 rc = -EREMOTE;
4598                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4599                         } else
4600                                 dfs_cache_free_tgts(&ntl);
4601                 }
4602                 break;
4603         }
4604
4605 out:
4606         kfree(share);
4607         kfree(prefix);
4608
4609         return rc;
4610 }
4611
4612 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4613                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4614                                    struct dfs_cache_tgt_list *tl)
4615 {
4616         int rc;
4617         int num_links = 0;
4618         struct TCP_Server_Info *server = tcon->ses->server;
4619
4620         do {
4621                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4622                 if (!rc || rc != -EREMOTE)
4623                         break;
4624         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4625         /*
4626          * If we couldn't tree connect to any targets from last referral path, then retry from
4627          * original referral path.
4628          */
4629         if (rc && server->current_fullpath != server->origin_fullpath) {
4630                 server->current_fullpath = server->origin_fullpath;
4631                 cifs_signal_cifsd_for_reconnect(server, true);
4632         }
4633
4634         dfs_cache_free_tgts(tl);
4635         return rc;
4636 }
4637
4638 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4639 {
4640         int rc;
4641         struct TCP_Server_Info *server = tcon->ses->server;
4642         const struct smb_version_operations *ops = server->ops;
4643         struct super_block *sb = NULL;
4644         struct cifs_sb_info *cifs_sb;
4645         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4646         char *tree;
4647         struct dfs_info3_param ref = {0};
4648
4649         /* only send once per connect */
4650         spin_lock(&tcon->tc_lock);
4651         if (tcon->ses->ses_status != SES_GOOD ||
4652             (tcon->status != TID_NEW &&
4653             tcon->status != TID_NEED_TCON)) {
4654                 spin_unlock(&tcon->tc_lock);
4655                 return 0;
4656         }
4657         tcon->status = TID_IN_TCON;
4658         spin_unlock(&tcon->tc_lock);
4659
4660         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4661         if (!tree) {
4662                 rc = -ENOMEM;
4663                 goto out;
4664         }
4665
4666         if (tcon->ipc) {
4667                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4668                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4669                 goto out;
4670         }
4671
4672         sb = cifs_get_tcp_super(server);
4673         if (IS_ERR(sb)) {
4674                 rc = PTR_ERR(sb);
4675                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4676                 goto out;
4677         }
4678
4679         cifs_sb = CIFS_SB(sb);
4680
4681         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4682         if (!server->current_fullpath ||
4683             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4684                 rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls);
4685                 goto out;
4686         }
4687
4688         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4689                                      &tl);
4690         free_dfs_info_param(&ref);
4691
4692 out:
4693         kfree(tree);
4694         cifs_put_tcp_super(sb);
4695
4696         if (rc) {
4697                 spin_lock(&tcon->tc_lock);
4698                 if (tcon->status == TID_IN_TCON)
4699                         tcon->status = TID_NEED_TCON;
4700                 spin_unlock(&tcon->tc_lock);
4701         } else {
4702                 spin_lock(&tcon->tc_lock);
4703                 if (tcon->status == TID_IN_TCON)
4704                         tcon->status = TID_GOOD;
4705                 spin_unlock(&tcon->tc_lock);
4706                 tcon->need_reconnect = false;
4707         }
4708
4709         return rc;
4710 }
4711 #else
4712 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4713 {
4714         int rc;
4715         const struct smb_version_operations *ops = tcon->ses->server->ops;
4716
4717         /* only send once per connect */
4718         spin_lock(&tcon->tc_lock);
4719         if (tcon->ses->ses_status != SES_GOOD ||
4720             (tcon->status != TID_NEW &&
4721             tcon->status != TID_NEED_TCON)) {
4722                 spin_unlock(&tcon->tc_lock);
4723                 return 0;
4724         }
4725         tcon->status = TID_IN_TCON;
4726         spin_unlock(&tcon->tc_lock);
4727
4728         rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4729         if (rc) {
4730                 spin_lock(&tcon->tc_lock);
4731                 if (tcon->status == TID_IN_TCON)
4732                         tcon->status = TID_NEED_TCON;
4733                 spin_unlock(&tcon->tc_lock);
4734         } else {
4735                 spin_lock(&tcon->tc_lock);
4736                 if (tcon->status == TID_IN_TCON)
4737                         tcon->status = TID_GOOD;
4738                 tcon->need_reconnect = false;
4739                 spin_unlock(&tcon->tc_lock);
4740         }
4741
4742         return rc;
4743 }
4744 #endif