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                         ses->tcon_ipc->status = TID_NEED_RECON;
 285                 }
 286
 287 next_session:
 288                 spin_unlock(&ses->chan_lock);
 289         }
 290         spin_unlock(&cifs_tcp_ses_lock);
 291 }
 292
 293 static void
 294 cifs_abort_connection(struct TCP_Server_Info *server)
 295 {
 296         struct mid_q_entry *mid, *nmid;
 297         struct list_head retry_list;
 298
 299         server->maxBuf = 0;
 300         server->max_read = 0;
 301
 302         /* do not want to be sending data on a socket we are freeing */
 303         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 304         cifs_server_lock(server);
 305         if (server->ssocket) {
 306                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 307                          server->ssocket->flags);
 308                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 309                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 310                          server->ssocket->flags);
 311                 sock_release(server->ssocket);
 312                 server->ssocket = NULL;
 313         }
 314         server->sequence_number = 0;
 315         server->session_estab = false;
 316         kfree_sensitive(server->session_key.response);
 317         server->session_key.response = NULL;
 318         server->session_key.len = 0;
 319         server->lstrp = jiffies;
 320
 321         /* mark submitted MIDs for retry and issue callback */
 322         INIT_LIST_HEAD(&retry_list);
 323         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 324         spin_lock(&server->mid_lock);
 325         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 326                 kref_get(&mid->refcount);
 327                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 328                         mid->mid_state = MID_RETRY_NEEDED;
 329                 list_move(&mid->qhead, &retry_list);
 330                 mid->mid_flags |= MID_DELETED;
 331         }
 332         spin_unlock(&server->mid_lock);
 333         cifs_server_unlock(server);
 334
 335         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 336         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 337                 list_del_init(&mid->qhead);
 338                 mid->callback(mid);
 339                 release_mid(mid);
 340         }
 341
 342         if (cifs_rdma_enabled(server)) {
 343                 cifs_server_lock(server);
 344                 smbd_destroy(server);
 345                 cifs_server_unlock(server);
 346         }
 347 }
 348
 349 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 350 {
 351         spin_lock(&server->srv_lock);
 352         server->nr_targets = num_targets;
 353         if (server->tcpStatus == CifsExiting) {
 354                 /* the demux thread will exit normally next time through the loop */
 355                 spin_unlock(&server->srv_lock);
 356                 wake_up(&server->response_q);
 357                 return false;
 358         }
 359
 360         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 361         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 362                              server->hostname);
 363         server->tcpStatus = CifsNeedReconnect;
 364
 365         spin_unlock(&server->srv_lock);
 366         return true;
 367 }
 368
 369 /*
 370  * cifs tcp session reconnection
 371  *
 372  * mark tcp session as reconnecting so temporarily locked
 373  * mark all smb sessions as reconnecting for tcp session
 374  * reconnect tcp session
 375  * wake up waiters on reconnection? - (not needed currently)
 376  *
 377  * if mark_smb_session is passed as true, unconditionally mark
 378  * the smb session (and tcon) for reconnect as well. This value
 379  * doesn't really matter for non-multichannel scenario.
 380  *
 381  */
 382 static int __cifs_reconnect(struct TCP_Server_Info *server,
 383                             bool mark_smb_session)
 384 {
 385         int rc = 0;
 386
 387         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 388                 return 0;
 389
 390         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 391
 392         cifs_abort_connection(server);
 393
 394         do {
 395                 try_to_freeze();
 396                 cifs_server_lock(server);
 397
 398                 if (!cifs_swn_set_server_dstaddr(server)) {
 399                         /* resolve the hostname again to make sure that IP address is up-to-date */
 400                         rc = reconn_set_ipaddr_from_hostname(server);
 401                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 402                 }
 403
 404                 if (cifs_rdma_enabled(server))
 405                         rc = smbd_reconnect(server);
 406                 else
 407                         rc = generic_ip_connect(server);
 408                 if (rc) {
 409                         cifs_server_unlock(server);
 410                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 411                         msleep(3000);
 412                 } else {
 413                         atomic_inc(&tcpSesReconnectCount);
 414                         set_credits(server, 1);
 415                         spin_lock(&server->srv_lock);
 416                         if (server->tcpStatus != CifsExiting)
 417                                 server->tcpStatus = CifsNeedNegotiate;
 418                         spin_unlock(&server->srv_lock);
 419                         cifs_swn_reset_server_dstaddr(server);
 420                         cifs_server_unlock(server);
 421                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 422                 }
 423         } while (server->tcpStatus == CifsNeedReconnect);
 424
 425         spin_lock(&server->srv_lock);
 426         if (server->tcpStatus == CifsNeedNegotiate)
 427                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 428         spin_unlock(&server->srv_lock);
 429
 430         wake_up(&server->response_q);
 431         return rc;
 432 }
 433
 434 #ifdef CONFIG_CIFS_DFS_UPCALL
 435 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 436 {
 437         int rc;
 438         char *hostname;
 439
 440         if (!cifs_swn_set_server_dstaddr(server)) {
 441                 if (server->hostname != target) {
 442                         hostname = extract_hostname(target);
 443                         if (!IS_ERR(hostname)) {
 444                                 kfree(server->hostname);
 445                                 server->hostname = hostname;
 446                         } else {
 447                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 448                                          __func__, PTR_ERR(hostname));
 449                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 450                                          server->hostname);
 451                         }
 452                 }
 453                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 454                 rc = reconn_set_ipaddr_from_hostname(server);
 455                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 456         }
 457         /* Reconnect the socket */
 458         if (cifs_rdma_enabled(server))
 459                 rc = smbd_reconnect(server);
 460         else
 461                 rc = generic_ip_connect(server);
 462
 463         return rc;
 464 }
 465
 466 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 467                                      struct dfs_cache_tgt_iterator **target_hint)
 468 {
 469         int rc;
 470         struct dfs_cache_tgt_iterator *tit;
 471
 472         *target_hint = NULL;
 473
 474         /* If dfs target list is empty, then reconnect to last server */
 475         tit = dfs_cache_get_tgt_iterator(tl);
 476         if (!tit)
 477                 return __reconnect_target_unlocked(server, server->hostname);
 478
 479         /* Otherwise, try every dfs target in @tl */
 480         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 481                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 482                 if (!rc) {
 483                         *target_hint = tit;
 484                         break;
 485                 }
 486         }
 487         return rc;
 488 }
 489
 490 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 491 {
 492         int rc = 0;
 493         const char *refpath = server->current_fullpath + 1;
 494         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 495         struct dfs_cache_tgt_iterator *target_hint = NULL;
 496         int num_targets = 0;
 497
 498         /*
 499          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 500          *
 501          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 502          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 503          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 504          * refreshing the referral, so, in this case, default it to 1.
 505          */
 506         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 507                 num_targets = dfs_cache_get_nr_tgts(&tl);
 508         if (!num_targets)
 509                 num_targets = 1;
 510
 511         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 512                 return 0;
 513
 514         /*
 515          * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 516          * different server or share during failover.  It could be improved by adding some logic to
 517          * only do that in case it connects to a different server or share, though.
 518          */
 519         cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 520
 521         cifs_abort_connection(server);
 522
 523         do {
 524                 try_to_freeze();
 525                 cifs_server_lock(server);
 526
 527                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 528                 if (rc) {
 529                         /* Failed to reconnect socket */
 530                         cifs_server_unlock(server);
 531                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 532                         msleep(3000);
 533                         continue;
 534                 }
 535                 /*
 536                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 537                  * process waiting for reconnect will know it needs to re-establish session and tcon
 538                  * through the reconnected target server.
 539                  */
 540                 atomic_inc(&tcpSesReconnectCount);
 541                 set_credits(server, 1);
 542                 spin_lock(&server->srv_lock);
 543                 if (server->tcpStatus != CifsExiting)
 544                         server->tcpStatus = CifsNeedNegotiate;
 545                 spin_unlock(&server->srv_lock);
 546                 cifs_swn_reset_server_dstaddr(server);
 547                 cifs_server_unlock(server);
 548                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 549         } while (server->tcpStatus == CifsNeedReconnect);
 550
 551         if (target_hint)
 552                 dfs_cache_noreq_update_tgthint(refpath, target_hint);
 553
 554         dfs_cache_free_tgts(&tl);
 555
 556         /* Need to set up echo worker again once connection has been established */
 557         spin_lock(&server->srv_lock);
 558         if (server->tcpStatus == CifsNeedNegotiate)
 559                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 560         spin_unlock(&server->srv_lock);
 561
 562         wake_up(&server->response_q);
 563         return rc;
 564 }
 565
 566 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 567 {
 568         /* If tcp session is not an dfs connection, then reconnect to last target server */
 569         spin_lock(&server->srv_lock);
 570         if (!server->is_dfs_conn) {
 571                 spin_unlock(&server->srv_lock);
 572                 return __cifs_reconnect(server, mark_smb_session);
 573         }
 574         spin_unlock(&server->srv_lock);
 575
 576         mutex_lock(&server->refpath_lock);
 577         if (!server->origin_fullpath || !server->leaf_fullpath) {
 578                 mutex_unlock(&server->refpath_lock);
 579                 return __cifs_reconnect(server, mark_smb_session);
 580         }
 581         mutex_unlock(&server->refpath_lock);
 582
 583         return reconnect_dfs_server(server);
 584 }
 585 #else
 586 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 587 {
 588         return __cifs_reconnect(server, mark_smb_session);
 589 }
 590 #endif
 591
 592 static void
 593 cifs_echo_request(struct work_struct *work)
 594 {
 595         int rc;
 596         struct TCP_Server_Info *server = container_of(work,
 597                                         struct TCP_Server_Info, echo.work);
 598
 599         /*
 600          * We cannot send an echo if it is disabled.
 601          * Also, no need to ping if we got a response recently.
 602          */
 603
 604         if (server->tcpStatus == CifsNeedReconnect ||
 605             server->tcpStatus == CifsExiting ||
 606             server->tcpStatus == CifsNew ||
 607             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 608             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 609                 goto requeue_echo;
 610
 611         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 612         if (rc)
 613                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 614                          server->hostname);
 615
 616         /* Check witness registrations */
 617         cifs_swn_check();
 618
 619 requeue_echo:
 620         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 621 }
 622
 623 static bool
 624 allocate_buffers(struct TCP_Server_Info *server)
 625 {
 626         if (!server->bigbuf) {
 627                 server->bigbuf = (char *)cifs_buf_get();
 628                 if (!server->bigbuf) {
 629                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 630                         msleep(3000);
 631                         /* retry will check if exiting */
 632                         return false;
 633                 }
 634         } else if (server->large_buf) {
 635                 /* we are reusing a dirty large buf, clear its start */
 636                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 637         }
 638
 639         if (!server->smallbuf) {
 640                 server->smallbuf = (char *)cifs_small_buf_get();
 641                 if (!server->smallbuf) {
 642                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 643                         msleep(1000);
 644                         /* retry will check if exiting */
 645                         return false;
 646                 }
 647                 /* beginning of smb buffer is cleared in our buf_get */
 648         } else {
 649                 /* if existing small buf clear beginning */
 650                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 651         }
 652
 653         return true;
 654 }
 655
 656 static bool
 657 server_unresponsive(struct TCP_Server_Info *server)
 658 {
 659         /*
 660          * We need to wait 3 echo intervals to make sure we handle such
 661          * situations right:
 662          * 1s  client sends a normal SMB request
 663          * 2s  client gets a response
 664          * 30s echo workqueue job pops, and decides we got a response recently
 665          *     and don't need to send another
 666          * ...
 667          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 668          *     a response in >60s.
 669          */
 670         spin_lock(&server->srv_lock);
 671         if ((server->tcpStatus == CifsGood ||
 672             server->tcpStatus == CifsNeedNegotiate) &&
 673             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 674             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 675                 spin_unlock(&server->srv_lock);
 676                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 677                          (3 * server->echo_interval) / HZ);
 678                 cifs_reconnect(server, false);
 679                 return true;
 680         }
 681         spin_unlock(&server->srv_lock);
 682
 683         return false;
 684 }
 685
 686 static inline bool
 687 zero_credits(struct TCP_Server_Info *server)
 688 {
 689         int val;
 690
 691         spin_lock(&server->req_lock);
 692         val = server->credits + server->echo_credits + server->oplock_credits;
 693         if (server->in_flight == 0 && val == 0) {
 694                 spin_unlock(&server->req_lock);
 695                 return true;
 696         }
 697         spin_unlock(&server->req_lock);
 698         return false;
 699 }
 700
 701 static int
 702 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 703 {
 704         int length = 0;
 705         int total_read;
 706
 707         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 708                 try_to_freeze();
 709
 710                 /* reconnect if no credits and no requests in flight */
 711                 if (zero_credits(server)) {
 712                         cifs_reconnect(server, false);
 713                         return -ECONNABORTED;
 714                 }
 715
 716                 if (server_unresponsive(server))
 717                         return -ECONNABORTED;
 718                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 719                         length = smbd_recv(server->smbd_conn, smb_msg);
 720                 else
 721                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 722
 723                 spin_lock(&server->srv_lock);
 724                 if (server->tcpStatus == CifsExiting) {
 725                         spin_unlock(&server->srv_lock);
 726                         return -ESHUTDOWN;
 727                 }
 728
 729                 if (server->tcpStatus == CifsNeedReconnect) {
 730                         spin_unlock(&server->srv_lock);
 731                         cifs_reconnect(server, false);
 732                         return -ECONNABORTED;
 733                 }
 734                 spin_unlock(&server->srv_lock);
 735
 736                 if (length == -ERESTARTSYS ||
 737                     length == -EAGAIN ||
 738                     length == -EINTR) {
 739                         /*
 740                          * Minimum sleep to prevent looping, allowing socket
 741                          * to clear and app threads to set tcpStatus
 742                          * CifsNeedReconnect if server hung.
 743                          */
 744                         usleep_range(1000, 2000);
 745                         length = 0;
 746                         continue;
 747                 }
 748
 749                 if (length <= 0) {
 750                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 751                         cifs_reconnect(server, false);
 752                         return -ECONNABORTED;
 753                 }
 754         }
 755         return total_read;
 756 }
 757
 758 int
 759 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 760                       unsigned int to_read)
 761 {
 762         struct msghdr smb_msg = {};
 763         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 764         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 765
 766         return cifs_readv_from_socket(server, &smb_msg);
 767 }
 768
 769 ssize_t
 770 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 771 {
 772         struct msghdr smb_msg = {};
 773
 774         /*
 775          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 776          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 777          *  so little to initialize in struct msghdr
 778          */
 779         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 780
 781         return cifs_readv_from_socket(server, &smb_msg);
 782 }
 783
 784 int
 785 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 786         unsigned int page_offset, unsigned int to_read)
 787 {
 788         struct msghdr smb_msg = {};
 789         struct bio_vec bv = {
 790                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 791         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 792         return cifs_readv_from_socket(server, &smb_msg);
 793 }
 794
 795 static bool
 796 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 797 {
 798         /*
 799          * The first byte big endian of the length field,
 800          * is actually not part of the length but the type
 801          * with the most common, zero, as regular data.
 802          */
 803         switch (type) {
 804         case RFC1002_SESSION_MESSAGE:
 805                 /* Regular SMB response */
 806                 return true;
 807         case RFC1002_SESSION_KEEP_ALIVE:
 808                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 809                 break;
 810         case RFC1002_POSITIVE_SESSION_RESPONSE:
 811                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 812                 break;
 813         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 814                 /*
 815                  * We get this from Windows 98 instead of an error on
 816                  * SMB negprot response.
 817                  */
 818                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 819                 /* give server a second to clean up */
 820                 msleep(1000);
 821                 /*
 822                  * Always try 445 first on reconnect since we get NACK
 823                  * on some if we ever connected to port 139 (the NACK
 824                  * is since we do not begin with RFC1001 session
 825                  * initialize frame).
 826                  */
 827                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 828                 cifs_reconnect(server, true);
 829                 break;
 830         default:
 831                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 832                 cifs_reconnect(server, true);
 833         }
 834
 835         return false;
 836 }
 837
 838 void
 839 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 840 {
 841 #ifdef CONFIG_CIFS_STATS2
 842         mid->when_received = jiffies;
 843 #endif
 844         spin_lock(&mid->server->mid_lock);
 845         if (!malformed)
 846                 mid->mid_state = MID_RESPONSE_RECEIVED;
 847         else
 848                 mid->mid_state = MID_RESPONSE_MALFORMED;
 849         /*
 850          * Trying to handle/dequeue a mid after the send_recv()
 851          * function has finished processing it is a bug.
 852          */
 853         if (mid->mid_flags & MID_DELETED) {
 854                 spin_unlock(&mid->server->mid_lock);
 855                 pr_warn_once("trying to dequeue a deleted mid\n");
 856         } else {
 857                 list_del_init(&mid->qhead);
 858                 mid->mid_flags |= MID_DELETED;
 859                 spin_unlock(&mid->server->mid_lock);
 860         }
 861 }
 862
 863 static unsigned int
 864 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 865 {
 866         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 867
 868         /*
 869          * SMB1 does not use credits.
 870          */
 871         if (is_smb1(server))
 872                 return 0;
 873
 874         return le16_to_cpu(shdr->CreditRequest);
 875 }
 876
 877 static void
 878 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 879            char *buf, int malformed)
 880 {
 881         if (server->ops->check_trans2 &&
 882             server->ops->check_trans2(mid, server, buf, malformed))
 883                 return;
 884         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 885         mid->resp_buf = buf;
 886         mid->large_buf = server->large_buf;
 887         /* Was previous buf put in mpx struct for multi-rsp? */
 888         if (!mid->multiRsp) {
 889                 /* smb buffer will be freed by user thread */
 890                 if (server->large_buf)
 891                         server->bigbuf = NULL;
 892                 else
 893                         server->smallbuf = NULL;
 894         }
 895         dequeue_mid(mid, malformed);
 896 }
 897
 898 int
 899 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 900 {
 901         bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 902         bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 903         bool mnt_sign_enabled;
 904
 905         /*
 906          * Is signing required by mnt options? If not then check
 907          * global_secflags to see if it is there.
 908          */
 909         if (!mnt_sign_required)
 910                 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 911                                                 CIFSSEC_MUST_SIGN);
 912
 913         /*
 914          * If signing is required then it's automatically enabled too,
 915          * otherwise, check to see if the secflags allow it.
 916          */
 917         mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 918                                 (global_secflags & CIFSSEC_MAY_SIGN);
 919
 920         /* If server requires signing, does client allow it? */
 921         if (srv_sign_required) {
 922                 if (!mnt_sign_enabled) {
 923                         cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 924                         return -EOPNOTSUPP;
 925                 }
 926                 server->sign = true;
 927         }
 928
 929         /* If client requires signing, does server allow it? */
 930         if (mnt_sign_required) {
 931                 if (!srv_sign_enabled) {
 932                         cifs_dbg(VFS, "Server does not support signing!\n");
 933                         return -EOPNOTSUPP;
 934                 }
 935                 server->sign = true;
 936         }
 937
 938         if (cifs_rdma_enabled(server) && server->sign)
 939                 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 940
 941         return 0;
 942 }
 943
 944
 945 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 946 {
 947         int length;
 948
 949         /* take it off the list, if it's not already */
 950         spin_lock(&server->srv_lock);
 951         list_del_init(&server->tcp_ses_list);
 952         spin_unlock(&server->srv_lock);
 953
 954         cancel_delayed_work_sync(&server->echo);
 955         cancel_delayed_work_sync(&server->resolve);
 956
 957         spin_lock(&server->srv_lock);
 958         server->tcpStatus = CifsExiting;
 959         spin_unlock(&server->srv_lock);
 960         wake_up_all(&server->response_q);
 961
 962         /* check if we have blocked requests that need to free */
 963         spin_lock(&server->req_lock);
 964         if (server->credits <= 0)
 965                 server->credits = 1;
 966         spin_unlock(&server->req_lock);
 967         /*
 968          * Although there should not be any requests blocked on this queue it
 969          * can not hurt to be paranoid and try to wake up requests that may
 970          * haven been blocked when more than 50 at time were on the wire to the
 971          * same server - they now will see the session is in exit state and get
 972          * out of SendReceive.
 973          */
 974         wake_up_all(&server->request_q);
 975         /* give those requests time to exit */
 976         msleep(125);
 977         if (cifs_rdma_enabled(server))
 978                 smbd_destroy(server);
 979         if (server->ssocket) {
 980                 sock_release(server->ssocket);
 981                 server->ssocket = NULL;
 982         }
 983
 984         if (!list_empty(&server->pending_mid_q)) {
 985                 struct list_head dispose_list;
 986                 struct mid_q_entry *mid_entry;
 987                 struct list_head *tmp, *tmp2;
 988
 989                 INIT_LIST_HEAD(&dispose_list);
 990                 spin_lock(&server->mid_lock);
 991                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 992                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 993                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 994                         kref_get(&mid_entry->refcount);
 995                         mid_entry->mid_state = MID_SHUTDOWN;
 996                         list_move(&mid_entry->qhead, &dispose_list);
 997                         mid_entry->mid_flags |= MID_DELETED;
 998                 }
 999                 spin_unlock(&server->mid_lock);
1000
1001                 /* now walk dispose list and issue callbacks */
1002                 list_for_each_safe(tmp, tmp2, &dispose_list) {
1003                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
1004                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
1005                         list_del_init(&mid_entry->qhead);
1006                         mid_entry->callback(mid_entry);
1007                         release_mid(mid_entry);
1008                 }
1009                 /* 1/8th of sec is more than enough time for them to exit */
1010                 msleep(125);
1011         }
1012
1013         if (!list_empty(&server->pending_mid_q)) {
1014                 /*
1015                  * mpx threads have not exited yet give them at least the smb
1016                  * send timeout time for long ops.
1017                  *
1018                  * Due to delays on oplock break requests, we need to wait at
1019                  * least 45 seconds before giving up on a request getting a
1020                  * response and going ahead and killing cifsd.
1021                  */
1022                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
1023                 msleep(46000);
1024                 /*
1025                  * If threads still have not exited they are probably never
1026                  * coming home not much else we can do but free the memory.
1027                  */
1028         }
1029
1030 #ifdef CONFIG_CIFS_DFS_UPCALL
1031         kfree(server->origin_fullpath);
1032         kfree(server->leaf_fullpath);
1033 #endif
1034         kfree(server);
1035
1036         length = atomic_dec_return(&tcpSesAllocCount);
1037         if (length > 0)
1038                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1039 }
1040
1041 static int
1042 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1043 {
1044         int length;
1045         char *buf = server->smallbuf;
1046         unsigned int pdu_length = server->pdu_size;
1047
1048         /* make sure this will fit in a large buffer */
1049         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1050             HEADER_PREAMBLE_SIZE(server)) {
1051                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1052                 cifs_reconnect(server, true);
1053                 return -ECONNABORTED;
1054         }
1055
1056         /* switch to large buffer if too big for a small one */
1057         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1058                 server->large_buf = true;
1059                 memcpy(server->bigbuf, buf, server->total_read);
1060                 buf = server->bigbuf;
1061         }
1062
1063         /* now read the rest */
1064         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1065                                        pdu_length - MID_HEADER_SIZE(server));
1066
1067         if (length < 0)
1068                 return length;
1069         server->total_read += length;
1070
1071         dump_smb(buf, server->total_read);
1072
1073         return cifs_handle_standard(server, mid);
1074 }
1075
1076 int
1077 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1078 {
1079         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1080         int rc;
1081
1082         /*
1083          * We know that we received enough to get to the MID as we
1084          * checked the pdu_length earlier. Now check to see
1085          * if the rest of the header is OK.
1086          *
1087          * 48 bytes is enough to display the header and a little bit
1088          * into the payload for debugging purposes.
1089          */
1090         rc = server->ops->check_message(buf, server->total_read, server);
1091         if (rc)
1092                 cifs_dump_mem("Bad SMB: ", buf,
1093                         min_t(unsigned int, server->total_read, 48));
1094
1095         if (server->ops->is_session_expired &&
1096             server->ops->is_session_expired(buf)) {
1097                 cifs_reconnect(server, true);
1098                 return -1;
1099         }
1100
1101         if (server->ops->is_status_pending &&
1102             server->ops->is_status_pending(buf, server))
1103                 return -1;
1104
1105         if (!mid)
1106                 return rc;
1107
1108         handle_mid(mid, server, buf, rc);
1109         return 0;
1110 }
1111
1112 static void
1113 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1114 {
1115         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1116         int scredits, in_flight;
1117
1118         /*
1119          * SMB1 does not use credits.
1120          */
1121         if (is_smb1(server))
1122                 return;
1123
1124         if (shdr->CreditRequest) {
1125                 spin_lock(&server->req_lock);
1126                 server->credits += le16_to_cpu(shdr->CreditRequest);
1127                 scredits = server->credits;
1128                 in_flight = server->in_flight;
1129                 spin_unlock(&server->req_lock);
1130                 wake_up(&server->request_q);
1131
1132                 trace_smb3_hdr_credits(server->CurrentMid,
1133                                 server->conn_id, server->hostname, scredits,
1134                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1135                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1136                                 __func__, le16_to_cpu(shdr->CreditRequest),
1137                                 scredits);
1138         }
1139 }
1140
1141
1142 static int
1143 cifs_demultiplex_thread(void *p)
1144 {
1145         int i, num_mids, length;
1146         struct TCP_Server_Info *server = p;
1147         unsigned int pdu_length;
1148         unsigned int next_offset;
1149         char *buf = NULL;
1150         struct task_struct *task_to_wake = NULL;
1151         struct mid_q_entry *mids[MAX_COMPOUND];
1152         char *bufs[MAX_COMPOUND];
1153         unsigned int noreclaim_flag, num_io_timeout = 0;
1154
1155         noreclaim_flag = memalloc_noreclaim_save();
1156         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1157
1158         length = atomic_inc_return(&tcpSesAllocCount);
1159         if (length > 1)
1160                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1161
1162         set_freezable();
1163         allow_kernel_signal(SIGKILL);
1164         while (server->tcpStatus != CifsExiting) {
1165                 if (try_to_freeze())
1166                         continue;
1167
1168                 if (!allocate_buffers(server))
1169                         continue;
1170
1171                 server->large_buf = false;
1172                 buf = server->smallbuf;
1173                 pdu_length = 4; /* enough to get RFC1001 header */
1174
1175                 length = cifs_read_from_socket(server, buf, pdu_length);
1176                 if (length < 0)
1177                         continue;
1178
1179                 if (is_smb1(server))
1180                         server->total_read = length;
1181                 else
1182                         server->total_read = 0;
1183
1184                 /*
1185                  * The right amount was read from socket - 4 bytes,
1186                  * so we can now interpret the length field.
1187                  */
1188                 pdu_length = get_rfc1002_length(buf);
1189
1190                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1191                 if (!is_smb_response(server, buf[0]))
1192                         continue;
1193 next_pdu:
1194                 server->pdu_size = pdu_length;
1195
1196                 /* make sure we have enough to get to the MID */
1197                 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1198                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1199                                  server->pdu_size);
1200                         cifs_reconnect(server, true);
1201                         continue;
1202                 }
1203
1204                 /* read down to the MID */
1205                 length = cifs_read_from_socket(server,
1206                              buf + HEADER_PREAMBLE_SIZE(server),
1207                              MID_HEADER_SIZE(server));
1208                 if (length < 0)
1209                         continue;
1210                 server->total_read += length;
1211
1212                 if (server->ops->next_header) {
1213                         next_offset = server->ops->next_header(buf);
1214                         if (next_offset)
1215                                 server->pdu_size = next_offset;
1216                 }
1217
1218                 memset(mids, 0, sizeof(mids));
1219                 memset(bufs, 0, sizeof(bufs));
1220                 num_mids = 0;
1221
1222                 if (server->ops->is_transform_hdr &&
1223                     server->ops->receive_transform &&
1224                     server->ops->is_transform_hdr(buf)) {
1225                         length = server->ops->receive_transform(server,
1226                                                                 mids,
1227                                                                 bufs,
1228                                                                 &num_mids);
1229                 } else {
1230                         mids[0] = server->ops->find_mid(server, buf);
1231                         bufs[0] = buf;
1232                         num_mids = 1;
1233
1234                         if (!mids[0] || !mids[0]->receive)
1235                                 length = standard_receive3(server, mids[0]);
1236                         else
1237                                 length = mids[0]->receive(server, mids[0]);
1238                 }
1239
1240                 if (length < 0) {
1241                         for (i = 0; i < num_mids; i++)
1242                                 if (mids[i])
1243                                         release_mid(mids[i]);
1244                         continue;
1245                 }
1246
1247                 if (server->ops->is_status_io_timeout &&
1248                     server->ops->is_status_io_timeout(buf)) {
1249                         num_io_timeout++;
1250                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1251                                 cifs_reconnect(server, false);
1252                                 num_io_timeout = 0;
1253                                 continue;
1254                         }
1255                 }
1256
1257                 server->lstrp = jiffies;
1258
1259                 for (i = 0; i < num_mids; i++) {
1260                         if (mids[i] != NULL) {
1261                                 mids[i]->resp_buf_size = server->pdu_size;
1262
1263                                 if (bufs[i] && server->ops->is_network_name_deleted)
1264                                         server->ops->is_network_name_deleted(bufs[i],
1265                                                                         server);
1266
1267                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1268                                         mids[i]->callback(mids[i]);
1269
1270                                 release_mid(mids[i]);
1271                         } else if (server->ops->is_oplock_break &&
1272                                    server->ops->is_oplock_break(bufs[i],
1273                                                                 server)) {
1274                                 smb2_add_credits_from_hdr(bufs[i], server);
1275                                 cifs_dbg(FYI, "Received oplock break\n");
1276                         } else {
1277                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1278                                                 atomic_read(&mid_count));
1279                                 cifs_dump_mem("Received Data is: ", bufs[i],
1280                                               HEADER_SIZE(server));
1281                                 smb2_add_credits_from_hdr(bufs[i], server);
1282 #ifdef CONFIG_CIFS_DEBUG2
1283                                 if (server->ops->dump_detail)
1284                                         server->ops->dump_detail(bufs[i],
1285                                                                  server);
1286                                 cifs_dump_mids(server);
1287 #endif /* CIFS_DEBUG2 */
1288                         }
1289                 }
1290
1291                 if (pdu_length > server->pdu_size) {
1292                         if (!allocate_buffers(server))
1293                                 continue;
1294                         pdu_length -= server->pdu_size;
1295                         server->total_read = 0;
1296                         server->large_buf = false;
1297                         buf = server->smallbuf;
1298                         goto next_pdu;
1299                 }
1300         } /* end while !EXITING */
1301
1302         /* buffer usually freed in free_mid - need to free it here on exit */
1303         cifs_buf_release(server->bigbuf);
1304         if (server->smallbuf) /* no sense logging a debug message if NULL */
1305                 cifs_small_buf_release(server->smallbuf);
1306
1307         task_to_wake = xchg(&server->tsk, NULL);
1308         clean_demultiplex_info(server);
1309
1310         /* if server->tsk was NULL then wait for a signal before exiting */
1311         if (!task_to_wake) {
1312                 set_current_state(TASK_INTERRUPTIBLE);
1313                 while (!signal_pending(current)) {
1314                         schedule();
1315                         set_current_state(TASK_INTERRUPTIBLE);
1316                 }
1317                 set_current_state(TASK_RUNNING);
1318         }
1319
1320         memalloc_noreclaim_restore(noreclaim_flag);
1321         module_put_and_kthread_exit(0);
1322 }
1323
1324 /*
1325  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1326  * if srcaddr is specified and matches the IP address of the rhs argument
1327  */
1328 bool
1329 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1330 {
1331         switch (srcaddr->sa_family) {
1332         case AF_UNSPEC:
1333                 return (rhs->sa_family == AF_UNSPEC);
1334         case AF_INET: {
1335                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1336                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1337                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1338         }
1339         case AF_INET6: {
1340                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1341                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1342                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1343         }
1344         default:
1345                 WARN_ON(1);
1346                 return false; /* don't expect to be here */
1347         }
1348 }
1349
1350 /*
1351  * If no port is specified in addr structure, we try to match with 445 port
1352  * and if it fails - with 139 ports. It should be called only if address
1353  * families of server and addr are equal.
1354  */
1355 static bool
1356 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1357 {
1358         __be16 port, *sport;
1359
1360         /* SMBDirect manages its own ports, don't match it here */
1361         if (server->rdma)
1362                 return true;
1363
1364         switch (addr->sa_family) {
1365         case AF_INET:
1366                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1367                 port = ((struct sockaddr_in *) addr)->sin_port;
1368                 break;
1369         case AF_INET6:
1370                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1371                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1372                 break;
1373         default:
1374                 WARN_ON(1);
1375                 return false;
1376         }
1377
1378         if (!port) {
1379                 port = htons(CIFS_PORT);
1380                 if (port == *sport)
1381                         return true;
1382
1383                 port = htons(RFC1001_PORT);
1384         }
1385
1386         return port == *sport;
1387 }
1388
1389 static bool
1390 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1391               struct sockaddr *srcaddr)
1392 {
1393         switch (addr->sa_family) {
1394         case AF_INET: {
1395                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1396                 struct sockaddr_in *srv_addr4 =
1397                                         (struct sockaddr_in *)&server->dstaddr;
1398
1399                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1400                         return false;
1401                 break;
1402         }
1403         case AF_INET6: {
1404                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1405                 struct sockaddr_in6 *srv_addr6 =
1406                                         (struct sockaddr_in6 *)&server->dstaddr;
1407
1408                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1409                                      &srv_addr6->sin6_addr))
1410                         return false;
1411                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1412                         return false;
1413                 break;
1414         }
1415         default:
1416                 WARN_ON(1);
1417                 return false; /* don't expect to be here */
1418         }
1419
1420         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1421                 return false;
1422
1423         return true;
1424 }
1425
1426 static bool
1427 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1428 {
1429         /*
1430          * The select_sectype function should either return the ctx->sectype
1431          * that was specified, or "Unspecified" if that sectype was not
1432          * compatible with the given NEGOTIATE request.
1433          */
1434         if (server->ops->select_sectype(server, ctx->sectype)
1435              == Unspecified)
1436                 return false;
1437
1438         /*
1439          * Now check if signing mode is acceptable. No need to check
1440          * global_secflags at this point since if MUST_SIGN is set then
1441          * the server->sign had better be too.
1442          */
1443         if (ctx->sign && !server->sign)
1444                 return false;
1445
1446         return true;
1447 }
1448
1449 /* this function must be called with srv_lock held */
1450 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1451 {
1452         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1453
1454         if (ctx->nosharesock)
1455                 return 0;
1456
1457         /* this server does not share socket */
1458         if (server->nosharesock)
1459                 return 0;
1460
1461         /* If multidialect negotiation see if existing sessions match one */
1462         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1463                 if (server->vals->protocol_id < SMB30_PROT_ID)
1464                         return 0;
1465         } else if (strcmp(ctx->vals->version_string,
1466                    SMBDEFAULT_VERSION_STRING) == 0) {
1467                 if (server->vals->protocol_id < SMB21_PROT_ID)
1468                         return 0;
1469         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1470                 return 0;
1471
1472         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1473                 return 0;
1474
1475         if (strcasecmp(server->hostname, ctx->server_hostname))
1476                 return 0;
1477
1478         if (!match_address(server, addr,
1479                            (struct sockaddr *)&ctx->srcaddr))
1480                 return 0;
1481
1482         if (!match_port(server, addr))
1483                 return 0;
1484
1485         if (!match_security(server, ctx))
1486                 return 0;
1487
1488         if (server->echo_interval != ctx->echo_interval * HZ)
1489                 return 0;
1490
1491         if (server->rdma != ctx->rdma)
1492                 return 0;
1493
1494         if (server->ignore_signature != ctx->ignore_signature)
1495                 return 0;
1496
1497         if (server->min_offload != ctx->min_offload)
1498                 return 0;
1499
1500         return 1;
1501 }
1502
1503 struct TCP_Server_Info *
1504 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1505 {
1506         struct TCP_Server_Info *server;
1507
1508         spin_lock(&cifs_tcp_ses_lock);
1509         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1510                 spin_lock(&server->srv_lock);
1511 #ifdef CONFIG_CIFS_DFS_UPCALL
1512                 /*
1513                  * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
1514                  * DFS connections to do failover properly, so avoid sharing them with regular
1515                  * shares or even links that may connect to same server but having completely
1516                  * different failover targets.
1517                  */
1518                 if (server->is_dfs_conn) {
1519                         spin_unlock(&server->srv_lock);
1520                         continue;
1521                 }
1522 #endif
1523                 /*
1524                  * Skip ses channels since they're only handled in lower layers
1525                  * (e.g. cifs_send_recv).
1526                  */
1527                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx)) {
1528                         spin_unlock(&server->srv_lock);
1529                         continue;
1530                 }
1531                 spin_unlock(&server->srv_lock);
1532
1533                 ++server->srv_count;
1534                 spin_unlock(&cifs_tcp_ses_lock);
1535                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1536                 return server;
1537         }
1538         spin_unlock(&cifs_tcp_ses_lock);
1539         return NULL;
1540 }
1541
1542 void
1543 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1544 {
1545         struct task_struct *task;
1546
1547         spin_lock(&cifs_tcp_ses_lock);
1548         if (--server->srv_count > 0) {
1549                 spin_unlock(&cifs_tcp_ses_lock);
1550                 return;
1551         }
1552
1553         /* srv_count can never go negative */
1554         WARN_ON(server->srv_count < 0);
1555
1556         put_net(cifs_net_ns(server));
1557
1558         list_del_init(&server->tcp_ses_list);
1559         spin_unlock(&cifs_tcp_ses_lock);
1560
1561         /* For secondary channels, we pick up ref-count on the primary server */
1562         if (CIFS_SERVER_IS_CHAN(server))
1563                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1564
1565         cancel_delayed_work_sync(&server->echo);
1566         cancel_delayed_work_sync(&server->resolve);
1567
1568         if (from_reconnect)
1569                 /*
1570                  * Avoid deadlock here: reconnect work calls
1571                  * cifs_put_tcp_session() at its end. Need to be sure
1572                  * that reconnect work does nothing with server pointer after
1573                  * that step.
1574                  */
1575                 cancel_delayed_work(&server->reconnect);
1576         else
1577                 cancel_delayed_work_sync(&server->reconnect);
1578
1579         spin_lock(&server->srv_lock);
1580         server->tcpStatus = CifsExiting;
1581         spin_unlock(&server->srv_lock);
1582
1583         cifs_crypto_secmech_release(server);
1584
1585         kfree_sensitive(server->session_key.response);
1586         server->session_key.response = NULL;
1587         server->session_key.len = 0;
1588         kfree(server->hostname);
1589         server->hostname = NULL;
1590
1591         task = xchg(&server->tsk, NULL);
1592         if (task)
1593                 send_sig(SIGKILL, task, 1);
1594 }
1595
1596 struct TCP_Server_Info *
1597 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1598                      struct TCP_Server_Info *primary_server)
1599 {
1600         struct TCP_Server_Info *tcp_ses = NULL;
1601         int rc;
1602
1603         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1604
1605         /* see if we already have a matching tcp_ses */
1606         tcp_ses = cifs_find_tcp_session(ctx);
1607         if (tcp_ses)
1608                 return tcp_ses;
1609
1610         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1611         if (!tcp_ses) {
1612                 rc = -ENOMEM;
1613                 goto out_err;
1614         }
1615
1616         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1617         if (!tcp_ses->hostname) {
1618                 rc = -ENOMEM;
1619                 goto out_err;
1620         }
1621
1622         if (ctx->nosharesock)
1623                 tcp_ses->nosharesock = true;
1624
1625         tcp_ses->ops = ctx->ops;
1626         tcp_ses->vals = ctx->vals;
1627         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1628
1629         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1630         tcp_ses->noblockcnt = ctx->rootfs;
1631         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1632         tcp_ses->noautotune = ctx->noautotune;
1633         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1634         tcp_ses->rdma = ctx->rdma;
1635         tcp_ses->in_flight = 0;
1636         tcp_ses->max_in_flight = 0;
1637         tcp_ses->credits = 1;
1638         if (primary_server) {
1639                 spin_lock(&cifs_tcp_ses_lock);
1640                 ++primary_server->srv_count;
1641                 spin_unlock(&cifs_tcp_ses_lock);
1642                 tcp_ses->primary_server = primary_server;
1643         }
1644         init_waitqueue_head(&tcp_ses->response_q);
1645         init_waitqueue_head(&tcp_ses->request_q);
1646         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1647         mutex_init(&tcp_ses->_srv_mutex);
1648         memcpy(tcp_ses->workstation_RFC1001_name,
1649                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1650         memcpy(tcp_ses->server_RFC1001_name,
1651                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1652         tcp_ses->session_estab = false;
1653         tcp_ses->sequence_number = 0;
1654         tcp_ses->reconnect_instance = 1;
1655         tcp_ses->lstrp = jiffies;
1656         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1657         spin_lock_init(&tcp_ses->req_lock);
1658         spin_lock_init(&tcp_ses->srv_lock);
1659         spin_lock_init(&tcp_ses->mid_lock);
1660         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1661         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1662         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1663         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1664         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1665         mutex_init(&tcp_ses->reconnect_mutex);
1666 #ifdef CONFIG_CIFS_DFS_UPCALL
1667         mutex_init(&tcp_ses->refpath_lock);
1668 #endif
1669         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1670                sizeof(tcp_ses->srcaddr));
1671         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1672                 sizeof(tcp_ses->dstaddr));
1673         if (ctx->use_client_guid)
1674                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1675                        SMB2_CLIENT_GUID_SIZE);
1676         else
1677                 generate_random_uuid(tcp_ses->client_guid);
1678         /*
1679          * at this point we are the only ones with the pointer
1680          * to the struct since the kernel thread not created yet
1681          * no need to spinlock this init of tcpStatus or srv_count
1682          */
1683         tcp_ses->tcpStatus = CifsNew;
1684         ++tcp_ses->srv_count;
1685
1686         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1687                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1688                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1689         else
1690                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1691         if (tcp_ses->rdma) {
1692 #ifndef CONFIG_CIFS_SMB_DIRECT
1693                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1694                 rc = -ENOENT;
1695                 goto out_err_crypto_release;
1696 #endif
1697                 tcp_ses->smbd_conn = smbd_get_connection(
1698                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1699                 if (tcp_ses->smbd_conn) {
1700                         cifs_dbg(VFS, "RDMA transport established\n");
1701                         rc = 0;
1702                         goto smbd_connected;
1703                 } else {
1704                         rc = -ENOENT;
1705                         goto out_err_crypto_release;
1706                 }
1707         }
1708         rc = ip_connect(tcp_ses);
1709         if (rc < 0) {
1710                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1711                 goto out_err_crypto_release;
1712         }
1713 smbd_connected:
1714         /*
1715          * since we're in a cifs function already, we know that
1716          * this will succeed. No need for try_module_get().
1717          */
1718         __module_get(THIS_MODULE);
1719         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1720                                   tcp_ses, "cifsd");
1721         if (IS_ERR(tcp_ses->tsk)) {
1722                 rc = PTR_ERR(tcp_ses->tsk);
1723                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1724                 module_put(THIS_MODULE);
1725                 goto out_err_crypto_release;
1726         }
1727         tcp_ses->min_offload = ctx->min_offload;
1728         /*
1729          * at this point we are the only ones with the pointer
1730          * to the struct since the kernel thread not created yet
1731          * no need to spinlock this update of tcpStatus
1732          */
1733         spin_lock(&tcp_ses->srv_lock);
1734         tcp_ses->tcpStatus = CifsNeedNegotiate;
1735         spin_unlock(&tcp_ses->srv_lock);
1736
1737         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1738                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1739         else
1740                 tcp_ses->max_credits = ctx->max_credits;
1741
1742         tcp_ses->nr_targets = 1;
1743         tcp_ses->ignore_signature = ctx->ignore_signature;
1744         /* thread spawned, put it on the list */
1745         spin_lock(&cifs_tcp_ses_lock);
1746         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1747         spin_unlock(&cifs_tcp_ses_lock);
1748
1749         /* queue echo request delayed work */
1750         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1751
1752         /* queue dns resolution delayed work */
1753         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1754                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1755
1756         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1757
1758         return tcp_ses;
1759
1760 out_err_crypto_release:
1761         cifs_crypto_secmech_release(tcp_ses);
1762
1763         put_net(cifs_net_ns(tcp_ses));
1764
1765 out_err:
1766         if (tcp_ses) {
1767                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1768                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1769                 kfree(tcp_ses->hostname);
1770                 if (tcp_ses->ssocket)
1771                         sock_release(tcp_ses->ssocket);
1772                 kfree(tcp_ses);
1773         }
1774         return ERR_PTR(rc);
1775 }
1776
1777 /* this function must be called with ses_lock held */
1778 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1779 {
1780         if (ctx->sectype != Unspecified &&
1781             ctx->sectype != ses->sectype)
1782                 return 0;
1783
1784         /*
1785          * If an existing session is limited to less channels than
1786          * requested, it should not be reused
1787          */
1788         spin_lock(&ses->chan_lock);
1789         if (ses->chan_max < ctx->max_channels) {
1790                 spin_unlock(&ses->chan_lock);
1791                 return 0;
1792         }
1793         spin_unlock(&ses->chan_lock);
1794
1795         switch (ses->sectype) {
1796         case Kerberos:
1797                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1798                         return 0;
1799                 break;
1800         default:
1801                 /* NULL username means anonymous session */
1802                 if (ses->user_name == NULL) {
1803                         if (!ctx->nullauth)
1804                                 return 0;
1805                         break;
1806                 }
1807
1808                 /* anything else takes username/password */
1809                 if (strncmp(ses->user_name,
1810                             ctx->username ? ctx->username : "",
1811                             CIFS_MAX_USERNAME_LEN))
1812                         return 0;
1813                 if ((ctx->username && strlen(ctx->username) != 0) &&
1814                     ses->password != NULL &&
1815                     strncmp(ses->password,
1816                             ctx->password ? ctx->password : "",
1817                             CIFS_MAX_PASSWORD_LEN))
1818                         return 0;
1819         }
1820         return 1;
1821 }
1822
1823 /**
1824  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1825  * @ses: smb session to issue the request on
1826  * @ctx: the superblock configuration context to use for building the
1827  *       new tree connection for the IPC (interprocess communication RPC)
1828  *
1829  * A new IPC connection is made and stored in the session
1830  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1831  */
1832 static int
1833 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1834 {
1835         int rc = 0, xid;
1836         struct cifs_tcon *tcon;
1837         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1838         bool seal = false;
1839         struct TCP_Server_Info *server = ses->server;
1840
1841         /*
1842          * If the mount request that resulted in the creation of the
1843          * session requires encryption, force IPC to be encrypted too.
1844          */
1845         if (ctx->seal) {
1846                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1847                         seal = true;
1848                 else {
1849                         cifs_server_dbg(VFS,
1850                                  "IPC: server doesn't support encryption\n");
1851                         return -EOPNOTSUPP;
1852                 }
1853         }
1854
1855         tcon = tconInfoAlloc();
1856         if (tcon == NULL)
1857                 return -ENOMEM;
1858
1859         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1860
1861         xid = get_xid();
1862         tcon->ses = ses;
1863         tcon->ipc = true;
1864         tcon->seal = seal;
1865         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1866         free_xid(xid);
1867
1868         if (rc) {
1869                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1870                 tconInfoFree(tcon);
1871                 goto out;
1872         }
1873
1874         cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1875
1876         spin_lock(&tcon->tc_lock);
1877         tcon->status = TID_GOOD;
1878         spin_unlock(&tcon->tc_lock);
1879         ses->tcon_ipc = tcon;
1880 out:
1881         return rc;
1882 }
1883
1884 /**
1885  * cifs_free_ipc - helper to release the session IPC tcon
1886  * @ses: smb session to unmount the IPC from
1887  *
1888  * Needs to be called everytime a session is destroyed.
1889  *
1890  * On session close, the IPC is closed and the server must release all tcons of the session.
1891  * No need to send a tree disconnect here.
1892  *
1893  * Besides, it will make the server to not close durable and resilient files on session close, as
1894  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1895  */
1896 static int
1897 cifs_free_ipc(struct cifs_ses *ses)
1898 {
1899         struct cifs_tcon *tcon = ses->tcon_ipc;
1900
1901         if (tcon == NULL)
1902                 return 0;
1903
1904         tconInfoFree(tcon);
1905         ses->tcon_ipc = NULL;
1906         return 0;
1907 }
1908
1909 static struct cifs_ses *
1910 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1911 {
1912         struct cifs_ses *ses;
1913
1914         spin_lock(&cifs_tcp_ses_lock);
1915         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1916                 spin_lock(&ses->ses_lock);
1917                 if (ses->ses_status == SES_EXITING) {
1918                         spin_unlock(&ses->ses_lock);
1919                         continue;
1920                 }
1921                 if (!match_session(ses, ctx)) {
1922                         spin_unlock(&ses->ses_lock);
1923                         continue;
1924                 }
1925                 spin_unlock(&ses->ses_lock);
1926
1927                 ++ses->ses_count;
1928                 spin_unlock(&cifs_tcp_ses_lock);
1929                 return ses;
1930         }
1931         spin_unlock(&cifs_tcp_ses_lock);
1932         return NULL;
1933 }
1934
1935 void cifs_put_smb_ses(struct cifs_ses *ses)
1936 {
1937         unsigned int rc, xid;
1938         unsigned int chan_count;
1939         struct TCP_Server_Info *server = ses->server;
1940
1941         spin_lock(&ses->ses_lock);
1942         if (ses->ses_status == SES_EXITING) {
1943                 spin_unlock(&ses->ses_lock);
1944                 return;
1945         }
1946         spin_unlock(&ses->ses_lock);
1947
1948         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1949         cifs_dbg(FYI,
1950                  "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1951
1952         spin_lock(&cifs_tcp_ses_lock);
1953         if (--ses->ses_count > 0) {
1954                 spin_unlock(&cifs_tcp_ses_lock);
1955                 return;
1956         }
1957         spin_unlock(&cifs_tcp_ses_lock);
1958
1959         /* ses_count can never go negative */
1960         WARN_ON(ses->ses_count < 0);
1961
1962         if (ses->ses_status == SES_GOOD)
1963                 ses->ses_status = SES_EXITING;
1964
1965         cifs_free_ipc(ses);
1966
1967         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1968                 xid = get_xid();
1969                 rc = server->ops->logoff(xid, ses);
1970                 if (rc)
1971                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1972                                 __func__, rc);
1973                 _free_xid(xid);
1974         }
1975
1976         spin_lock(&cifs_tcp_ses_lock);
1977         list_del_init(&ses->smb_ses_list);
1978         spin_unlock(&cifs_tcp_ses_lock);
1979
1980         chan_count = ses->chan_count;
1981
1982         /* close any extra channels */
1983         if (chan_count > 1) {
1984                 int i;
1985
1986                 for (i = 1; i < chan_count; i++) {
1987                         if (ses->chans[i].iface) {
1988                                 kref_put(&ses->chans[i].iface->refcount, release_iface);
1989                                 ses->chans[i].iface = NULL;
1990                         }
1991                         cifs_put_tcp_session(ses->chans[i].server, 0);
1992                         ses->chans[i].server = NULL;
1993                 }
1994         }
1995
1996         sesInfoFree(ses);
1997         cifs_put_tcp_session(server, 0);
1998 }
1999
2000 #ifdef CONFIG_KEYS
2001
2002 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
2003 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2004
2005 /* Populate username and pw fields from keyring if possible */
2006 static int
2007 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2008 {
2009         int rc = 0;
2010         int is_domain = 0;
2011         const char *delim, *payload;
2012         char *desc;
2013         ssize_t len;
2014         struct key *key;
2015         struct TCP_Server_Info *server = ses->server;
2016         struct sockaddr_in *sa;
2017         struct sockaddr_in6 *sa6;
2018         const struct user_key_payload *upayload;
2019
2020         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2021         if (!desc)
2022                 return -ENOMEM;
2023
2024         /* try to find an address key first */
2025         switch (server->dstaddr.ss_family) {
2026         case AF_INET:
2027                 sa = (struct sockaddr_in *)&server->dstaddr;
2028                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2029                 break;
2030         case AF_INET6:
2031                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2032                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2033                 break;
2034         default:
2035                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2036                          server->dstaddr.ss_family);
2037                 rc = -EINVAL;
2038                 goto out_err;
2039         }
2040
2041         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2042         key = request_key(&key_type_logon, desc, "");
2043         if (IS_ERR(key)) {
2044                 if (!ses->domainName) {
2045                         cifs_dbg(FYI, "domainName is NULL\n");
2046                         rc = PTR_ERR(key);
2047                         goto out_err;
2048                 }
2049
2050                 /* didn't work, try to find a domain key */
2051                 sprintf(desc, "cifs:d:%s", ses->domainName);
2052                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2053                 key = request_key(&key_type_logon, desc, "");
2054                 if (IS_ERR(key)) {
2055                         rc = PTR_ERR(key);
2056                         goto out_err;
2057                 }
2058                 is_domain = 1;
2059         }
2060
2061         down_read(&key->sem);
2062         upayload = user_key_payload_locked(key);
2063         if (IS_ERR_OR_NULL(upayload)) {
2064                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2065                 goto out_key_put;
2066         }
2067
2068         /* find first : in payload */
2069         payload = upayload->data;
2070         delim = strnchr(payload, upayload->datalen, ':');
2071         cifs_dbg(FYI, "payload=%s\n", payload);
2072         if (!delim) {
2073                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2074                          upayload->datalen);
2075                 rc = -EINVAL;
2076                 goto out_key_put;
2077         }
2078
2079         len = delim - payload;
2080         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2081                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2082                          len);
2083                 rc = -EINVAL;
2084                 goto out_key_put;
2085         }
2086
2087         ctx->username = kstrndup(payload, len, GFP_KERNEL);
2088         if (!ctx->username) {
2089                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2090                          len);
2091                 rc = -ENOMEM;
2092                 goto out_key_put;
2093         }
2094         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2095
2096         len = key->datalen - (len + 1);
2097         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2098                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2099                 rc = -EINVAL;
2100                 kfree(ctx->username);
2101                 ctx->username = NULL;
2102                 goto out_key_put;
2103         }
2104
2105         ++delim;
2106         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2107         if (!ctx->password) {
2108                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2109                          len);
2110                 rc = -ENOMEM;
2111                 kfree(ctx->username);
2112                 ctx->username = NULL;
2113                 goto out_key_put;
2114         }
2115
2116         /*
2117          * If we have a domain key then we must set the domainName in the
2118          * for the request.
2119          */
2120         if (is_domain && ses->domainName) {
2121                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2122                 if (!ctx->domainname) {
2123                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2124                                  len);
2125                         rc = -ENOMEM;
2126                         kfree(ctx->username);
2127                         ctx->username = NULL;
2128                         kfree_sensitive(ctx->password);
2129                         ctx->password = NULL;
2130                         goto out_key_put;
2131                 }
2132         }
2133
2134         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2135
2136 out_key_put:
2137         up_read(&key->sem);
2138         key_put(key);
2139 out_err:
2140         kfree(desc);
2141         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2142         return rc;
2143 }
2144 #else /* ! CONFIG_KEYS */
2145 static inline int
2146 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2147                    struct cifs_ses *ses __attribute__((unused)))
2148 {
2149         return -ENOSYS;
2150 }
2151 #endif /* CONFIG_KEYS */
2152
2153 /**
2154  * cifs_get_smb_ses - get a session matching @ctx data from @server
2155  * @server: server to setup the session to
2156  * @ctx: superblock configuration context to use to setup the session
2157  *
2158  * This function assumes it is being called from cifs_mount() where we
2159  * already got a server reference (server refcount +1). See
2160  * cifs_get_tcon() for refcount explanations.
2161  */
2162 struct cifs_ses *
2163 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2164 {
2165         int rc = 0;
2166         unsigned int xid;
2167         struct cifs_ses *ses;
2168         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2169         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2170
2171         xid = get_xid();
2172
2173         ses = cifs_find_smb_ses(server, ctx);
2174         if (ses) {
2175                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2176                          ses->ses_status);
2177
2178                 spin_lock(&ses->chan_lock);
2179                 if (cifs_chan_needs_reconnect(ses, server)) {
2180                         spin_unlock(&ses->chan_lock);
2181                         cifs_dbg(FYI, "Session needs reconnect\n");
2182
2183                         mutex_lock(&ses->session_mutex);
2184                         rc = cifs_negotiate_protocol(xid, ses, server);
2185                         if (rc) {
2186                                 mutex_unlock(&ses->session_mutex);
2187                                 /* problem -- put our ses reference */
2188                                 cifs_put_smb_ses(ses);
2189                                 free_xid(xid);
2190                                 return ERR_PTR(rc);
2191                         }
2192
2193                         rc = cifs_setup_session(xid, ses, server,
2194                                                 ctx->local_nls);
2195                         if (rc) {
2196                                 mutex_unlock(&ses->session_mutex);
2197                                 /* problem -- put our reference */
2198                                 cifs_put_smb_ses(ses);
2199                                 free_xid(xid);
2200                                 return ERR_PTR(rc);
2201                         }
2202                         mutex_unlock(&ses->session_mutex);
2203
2204                         spin_lock(&ses->chan_lock);
2205                 }
2206                 spin_unlock(&ses->chan_lock);
2207
2208                 /* existing SMB ses has a server reference already */
2209                 cifs_put_tcp_session(server, 0);
2210                 free_xid(xid);
2211                 return ses;
2212         }
2213
2214         rc = -ENOMEM;
2215
2216         cifs_dbg(FYI, "Existing smb sess not found\n");
2217         ses = sesInfoAlloc();
2218         if (ses == NULL)
2219                 goto get_ses_fail;
2220
2221         /* new SMB session uses our server ref */
2222         ses->server = server;
2223         if (server->dstaddr.ss_family == AF_INET6)
2224                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2225         else
2226                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2227
2228         if (ctx->username) {
2229                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2230                 if (!ses->user_name)
2231                         goto get_ses_fail;
2232         }
2233
2234         /* ctx->password freed at unmount */
2235         if (ctx->password) {
2236                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2237                 if (!ses->password)
2238                         goto get_ses_fail;
2239         }
2240         if (ctx->domainname) {
2241                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2242                 if (!ses->domainName)
2243                         goto get_ses_fail;
2244         }
2245
2246         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2247
2248         if (ctx->domainauto)
2249                 ses->domainAuto = ctx->domainauto;
2250         ses->cred_uid = ctx->cred_uid;
2251         ses->linux_uid = ctx->linux_uid;
2252
2253         ses->sectype = ctx->sectype;
2254         ses->sign = ctx->sign;
2255
2256         /* add server as first channel */
2257         spin_lock(&ses->chan_lock);
2258         ses->chans[0].server = server;
2259         ses->chan_count = 1;
2260         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2261         ses->chans_need_reconnect = 1;
2262         spin_unlock(&ses->chan_lock);
2263
2264         mutex_lock(&ses->session_mutex);
2265         rc = cifs_negotiate_protocol(xid, ses, server);
2266         if (!rc)
2267                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2268         mutex_unlock(&ses->session_mutex);
2269
2270         /* each channel uses a different signing key */
2271         spin_lock(&ses->chan_lock);
2272         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2273                sizeof(ses->smb3signingkey));
2274         spin_unlock(&ses->chan_lock);
2275
2276         if (rc)
2277                 goto get_ses_fail;
2278
2279         /*
2280          * success, put it on the list and add it as first channel
2281          * note: the session becomes active soon after this. So you'll
2282          * need to lock before changing something in the session.
2283          */
2284         spin_lock(&cifs_tcp_ses_lock);
2285         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2286         spin_unlock(&cifs_tcp_ses_lock);
2287
2288         cifs_setup_ipc(ses, ctx);
2289
2290         free_xid(xid);
2291
2292         return ses;
2293
2294 get_ses_fail:
2295         sesInfoFree(ses);
2296         free_xid(xid);
2297         return ERR_PTR(rc);
2298 }
2299
2300 /* this function must be called with tc_lock held */
2301 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2302 {
2303         if (tcon->status == TID_EXITING)
2304                 return 0;
2305         if (strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2306                 return 0;
2307         if (tcon->seal != ctx->seal)
2308                 return 0;
2309         if (tcon->snapshot_time != ctx->snapshot_time)
2310                 return 0;
2311         if (tcon->handle_timeout != ctx->handle_timeout)
2312                 return 0;
2313         if (tcon->no_lease != ctx->no_lease)
2314                 return 0;
2315         if (tcon->nodelete != ctx->nodelete)
2316                 return 0;
2317         return 1;
2318 }
2319
2320 static struct cifs_tcon *
2321 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2322 {
2323         struct cifs_tcon *tcon;
2324
2325         spin_lock(&cifs_tcp_ses_lock);
2326         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2327                 spin_lock(&tcon->tc_lock);
2328                 if (!match_tcon(tcon, ctx)) {
2329                         spin_unlock(&tcon->tc_lock);
2330                         continue;
2331                 }
2332                 ++tcon->tc_count;
2333                 spin_unlock(&tcon->tc_lock);
2334                 spin_unlock(&cifs_tcp_ses_lock);
2335                 return tcon;
2336         }
2337         spin_unlock(&cifs_tcp_ses_lock);
2338         return NULL;
2339 }
2340
2341 void
2342 cifs_put_tcon(struct cifs_tcon *tcon)
2343 {
2344         unsigned int xid;
2345         struct cifs_ses *ses;
2346
2347         /*
2348          * IPC tcon share the lifetime of their session and are
2349          * destroyed in the session put function
2350          */
2351         if (tcon == NULL || tcon->ipc)
2352                 return;
2353
2354         ses = tcon->ses;
2355         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2356         spin_lock(&cifs_tcp_ses_lock);
2357         spin_lock(&tcon->tc_lock);
2358         if (--tcon->tc_count > 0) {
2359                 spin_unlock(&tcon->tc_lock);
2360                 spin_unlock(&cifs_tcp_ses_lock);
2361                 return;
2362         }
2363
2364         /* tc_count can never go negative */
2365         WARN_ON(tcon->tc_count < 0);
2366
2367         list_del_init(&tcon->tcon_list);
2368         spin_unlock(&tcon->tc_lock);
2369         spin_unlock(&cifs_tcp_ses_lock);
2370
2371         /* cancel polling of interfaces */
2372         cancel_delayed_work_sync(&tcon->query_interfaces);
2373
2374         if (tcon->use_witness) {
2375                 int rc;
2376
2377                 rc = cifs_swn_unregister(tcon);
2378                 if (rc < 0) {
2379                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2380                                         __func__, rc);
2381                 }
2382         }
2383
2384         xid = get_xid();
2385         if (ses->server->ops->tree_disconnect)
2386                 ses->server->ops->tree_disconnect(xid, tcon);
2387         _free_xid(xid);
2388
2389         cifs_fscache_release_super_cookie(tcon);
2390         tconInfoFree(tcon);
2391         cifs_put_smb_ses(ses);
2392 }
2393
2394 /**
2395  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2396  * @ses: smb session to issue the request on
2397  * @ctx: the superblock configuration context to use for building the
2398  *
2399  * - tcon refcount is the number of mount points using the tcon.
2400  * - ses refcount is the number of tcon using the session.
2401  *
2402  * 1. This function assumes it is being called from cifs_mount() where
2403  *    we already got a session reference (ses refcount +1).
2404  *
2405  * 2. Since we're in the context of adding a mount point, the end
2406  *    result should be either:
2407  *
2408  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2409  *    its session refcount incremented (1 new tcon). This +1 was
2410  *    already done in (1).
2411  *
2412  * b) an existing tcon with refcount+1 (add a mount point to it) and
2413  *    identical ses refcount (no new tcon). Because of (1) we need to
2414  *    decrement the ses refcount.
2415  */
2416 static struct cifs_tcon *
2417 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2418 {
2419         int rc, xid;
2420         struct cifs_tcon *tcon;
2421
2422         tcon = cifs_find_tcon(ses, ctx);
2423         if (tcon) {
2424                 /*
2425                  * tcon has refcount already incremented but we need to
2426                  * decrement extra ses reference gotten by caller (case b)
2427                  */
2428                 cifs_dbg(FYI, "Found match on UNC path\n");
2429                 cifs_put_smb_ses(ses);
2430                 return tcon;
2431         }
2432
2433         if (!ses->server->ops->tree_connect) {
2434                 rc = -ENOSYS;
2435                 goto out_fail;
2436         }
2437
2438         tcon = tconInfoAlloc();
2439         if (tcon == NULL) {
2440                 rc = -ENOMEM;
2441                 goto out_fail;
2442         }
2443
2444         if (ctx->snapshot_time) {
2445                 if (ses->server->vals->protocol_id == 0) {
2446                         cifs_dbg(VFS,
2447                              "Use SMB2 or later for snapshot mount option\n");
2448                         rc = -EOPNOTSUPP;
2449                         goto out_fail;
2450                 } else
2451                         tcon->snapshot_time = ctx->snapshot_time;
2452         }
2453
2454         if (ctx->handle_timeout) {
2455                 if (ses->server->vals->protocol_id == 0) {
2456                         cifs_dbg(VFS,
2457                              "Use SMB2.1 or later for handle timeout option\n");
2458                         rc = -EOPNOTSUPP;
2459                         goto out_fail;
2460                 } else
2461                         tcon->handle_timeout = ctx->handle_timeout;
2462         }
2463
2464         tcon->ses = ses;
2465         if (ctx->password) {
2466                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2467                 if (!tcon->password) {
2468                         rc = -ENOMEM;
2469                         goto out_fail;
2470                 }
2471         }
2472
2473         if (ctx->seal) {
2474                 if (ses->server->vals->protocol_id == 0) {
2475                         cifs_dbg(VFS,
2476                                  "SMB3 or later required for encryption\n");
2477                         rc = -EOPNOTSUPP;
2478                         goto out_fail;
2479                 } else if (tcon->ses->server->capabilities &
2480                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2481                         tcon->seal = true;
2482                 else {
2483                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2484                         rc = -EOPNOTSUPP;
2485                         goto out_fail;
2486                 }
2487         }
2488
2489         if (ctx->linux_ext) {
2490                 if (ses->server->posix_ext_supported) {
2491                         tcon->posix_extensions = true;
2492                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2493                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2494                     (strcmp(ses->server->vals->version_string,
2495                      SMB3ANY_VERSION_STRING) == 0) ||
2496                     (strcmp(ses->server->vals->version_string,
2497                      SMBDEFAULT_VERSION_STRING) == 0)) {
2498                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2499                         rc = -EOPNOTSUPP;
2500                         goto out_fail;
2501                 } else {
2502                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2503                                 "disabled but required for POSIX extensions\n");
2504                         rc = -EOPNOTSUPP;
2505                         goto out_fail;
2506                 }
2507         }
2508
2509         xid = get_xid();
2510         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2511                                             ctx->local_nls);
2512         free_xid(xid);
2513         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2514         if (rc)
2515                 goto out_fail;
2516
2517         tcon->use_persistent = false;
2518         /* check if SMB2 or later, CIFS does not support persistent handles */
2519         if (ctx->persistent) {
2520                 if (ses->server->vals->protocol_id == 0) {
2521                         cifs_dbg(VFS,
2522                              "SMB3 or later required for persistent handles\n");
2523                         rc = -EOPNOTSUPP;
2524                         goto out_fail;
2525                 } else if (ses->server->capabilities &
2526                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2527                         tcon->use_persistent = true;
2528                 else /* persistent handles requested but not supported */ {
2529                         cifs_dbg(VFS,
2530                                 "Persistent handles not supported on share\n");
2531                         rc = -EOPNOTSUPP;
2532                         goto out_fail;
2533                 }
2534         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2535              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2536              && (ctx->nopersistent == false)) {
2537                 cifs_dbg(FYI, "enabling persistent handles\n");
2538                 tcon->use_persistent = true;
2539         } else if (ctx->resilient) {
2540                 if (ses->server->vals->protocol_id == 0) {
2541                         cifs_dbg(VFS,
2542                              "SMB2.1 or later required for resilient handles\n");
2543                         rc = -EOPNOTSUPP;
2544                         goto out_fail;
2545                 }
2546                 tcon->use_resilient = true;
2547         }
2548
2549         tcon->use_witness = false;
2550         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2551                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2552                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2553                                 /*
2554                                  * Set witness in use flag in first place
2555                                  * to retry registration in the echo task
2556                                  */
2557                                 tcon->use_witness = true;
2558                                 /* And try to register immediately */
2559                                 rc = cifs_swn_register(tcon);
2560                                 if (rc < 0) {
2561                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2562                                         goto out_fail;
2563                                 }
2564                         } else {
2565                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2566                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2567                                 rc = -EOPNOTSUPP;
2568                                 goto out_fail;
2569                         }
2570                 } else {
2571                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2572                         rc = -EOPNOTSUPP;
2573                         goto out_fail;
2574                 }
2575         }
2576
2577         /* If the user really knows what they are doing they can override */
2578         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2579                 if (ctx->cache_ro)
2580                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2581                 else if (ctx->cache_rw)
2582                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2583         }
2584
2585         if (ctx->no_lease) {
2586                 if (ses->server->vals->protocol_id == 0) {
2587                         cifs_dbg(VFS,
2588                                 "SMB2 or later required for nolease option\n");
2589                         rc = -EOPNOTSUPP;
2590                         goto out_fail;
2591                 } else
2592                         tcon->no_lease = ctx->no_lease;
2593         }
2594
2595         /*
2596          * We can have only one retry value for a connection to a share so for
2597          * resources mounted more than once to the same server share the last
2598          * value passed in for the retry flag is used.
2599          */
2600         tcon->retry = ctx->retry;
2601         tcon->nocase = ctx->nocase;
2602         tcon->broken_sparse_sup = ctx->no_sparse;
2603         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2604                 tcon->nohandlecache = ctx->nohandlecache;
2605         else
2606                 tcon->nohandlecache = true;
2607         tcon->nodelete = ctx->nodelete;
2608         tcon->local_lease = ctx->local_lease;
2609         INIT_LIST_HEAD(&tcon->pending_opens);
2610         tcon->status = TID_GOOD;
2611
2612         INIT_DELAYED_WORK(&tcon->query_interfaces,
2613                           smb2_query_server_interfaces);
2614         if (ses->server->dialect >= SMB30_PROT_ID &&
2615             (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2616                 /* schedule query interfaces poll */
2617                 queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2618                                    (SMB_INTERFACE_POLL_INTERVAL * HZ));
2619         }
2620
2621         spin_lock(&cifs_tcp_ses_lock);
2622         list_add(&tcon->tcon_list, &ses->tcon_list);
2623         spin_unlock(&cifs_tcp_ses_lock);
2624
2625         return tcon;
2626
2627 out_fail:
2628         tconInfoFree(tcon);
2629         return ERR_PTR(rc);
2630 }
2631
2632 void
2633 cifs_put_tlink(struct tcon_link *tlink)
2634 {
2635         if (!tlink || IS_ERR(tlink))
2636                 return;
2637
2638         if (!atomic_dec_and_test(&tlink->tl_count) ||
2639             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2640                 tlink->tl_time = jiffies;
2641                 return;
2642         }
2643
2644         if (!IS_ERR(tlink_tcon(tlink)))
2645                 cifs_put_tcon(tlink_tcon(tlink));
2646         kfree(tlink);
2647         return;
2648 }
2649
2650 static int
2651 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2652 {
2653         struct cifs_sb_info *old = CIFS_SB(sb);
2654         struct cifs_sb_info *new = mnt_data->cifs_sb;
2655         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2656         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2657
2658         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2659                 return 0;
2660
2661         if (old->mnt_cifs_serverino_autodisabled)
2662                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2663
2664         if (oldflags != newflags)
2665                 return 0;
2666
2667         /*
2668          * We want to share sb only if we don't specify an r/wsize or
2669          * specified r/wsize is greater than or equal to existing one.
2670          */
2671         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2672                 return 0;
2673
2674         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2675                 return 0;
2676
2677         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2678             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2679                 return 0;
2680
2681         if (old->ctx->file_mode != new->ctx->file_mode ||
2682             old->ctx->dir_mode != new->ctx->dir_mode)
2683                 return 0;
2684
2685         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2686                 return 0;
2687
2688         if (old->ctx->acregmax != new->ctx->acregmax)
2689                 return 0;
2690         if (old->ctx->acdirmax != new->ctx->acdirmax)
2691                 return 0;
2692         if (old->ctx->closetimeo != new->ctx->closetimeo)
2693                 return 0;
2694
2695         return 1;
2696 }
2697
2698 static int
2699 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2700 {
2701         struct cifs_sb_info *old = CIFS_SB(sb);
2702         struct cifs_sb_info *new = mnt_data->cifs_sb;
2703         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2704                 old->prepath;
2705         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2706                 new->prepath;
2707
2708         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2709                 return 1;
2710         else if (!old_set && !new_set)
2711                 return 1;
2712
2713         return 0;
2714 }
2715
2716 int
2717 cifs_match_super(struct super_block *sb, void *data)
2718 {
2719         struct cifs_mnt_data *mnt_data = data;
2720         struct smb3_fs_context *ctx;
2721         struct cifs_sb_info *cifs_sb;
2722         struct TCP_Server_Info *tcp_srv;
2723         struct cifs_ses *ses;
2724         struct cifs_tcon *tcon;
2725         struct tcon_link *tlink;
2726         int rc = 0;
2727
2728         spin_lock(&cifs_tcp_ses_lock);
2729         cifs_sb = CIFS_SB(sb);
2730         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2731         if (tlink == NULL) {
2732                 /* can not match superblock if tlink were ever null */
2733                 spin_unlock(&cifs_tcp_ses_lock);
2734                 return 0;
2735         }
2736         tcon = tlink_tcon(tlink);
2737         ses = tcon->ses;
2738         tcp_srv = ses->server;
2739
2740         ctx = mnt_data->ctx;
2741
2742         spin_lock(&tcp_srv->srv_lock);
2743         spin_lock(&ses->ses_lock);
2744         spin_lock(&tcon->tc_lock);
2745         if (!match_server(tcp_srv, ctx) ||
2746             !match_session(ses, ctx) ||
2747             !match_tcon(tcon, ctx) ||
2748             !match_prepath(sb, mnt_data)) {
2749                 rc = 0;
2750                 goto out;
2751         }
2752
2753         rc = compare_mount_options(sb, mnt_data);
2754 out:
2755         spin_unlock(&tcon->tc_lock);
2756         spin_unlock(&ses->ses_lock);
2757         spin_unlock(&tcp_srv->srv_lock);
2758
2759         spin_unlock(&cifs_tcp_ses_lock);
2760         cifs_put_tlink(tlink);
2761         return rc;
2762 }
2763
2764 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2765 static struct lock_class_key cifs_key[2];
2766 static struct lock_class_key cifs_slock_key[2];
2767
2768 static inline void
2769 cifs_reclassify_socket4(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_INET-CIFS",
2774                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2775 }
2776
2777 static inline void
2778 cifs_reclassify_socket6(struct socket *sock)
2779 {
2780         struct sock *sk = sock->sk;
2781         BUG_ON(!sock_allow_reclassification(sk));
2782         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2783                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2784 }
2785 #else
2786 static inline void
2787 cifs_reclassify_socket4(struct socket *sock)
2788 {
2789 }
2790
2791 static inline void
2792 cifs_reclassify_socket6(struct socket *sock)
2793 {
2794 }
2795 #endif
2796
2797 /* See RFC1001 section 14 on representation of Netbios names */
2798 static void rfc1002mangle(char *target, char *source, unsigned int length)
2799 {
2800         unsigned int i, j;
2801
2802         for (i = 0, j = 0; i < (length); i++) {
2803                 /* mask a nibble at a time and encode */
2804                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2805                 target[j+1] = 'A' + (0x0F & source[i]);
2806                 j += 2;
2807         }
2808
2809 }
2810
2811 static int
2812 bind_socket(struct TCP_Server_Info *server)
2813 {
2814         int rc = 0;
2815         if (server->srcaddr.ss_family != AF_UNSPEC) {
2816                 /* Bind to the specified local IP address */
2817                 struct socket *socket = server->ssocket;
2818                 rc = socket->ops->bind(socket,
2819                                        (struct sockaddr *) &server->srcaddr,
2820                                        sizeof(server->srcaddr));
2821                 if (rc < 0) {
2822                         struct sockaddr_in *saddr4;
2823                         struct sockaddr_in6 *saddr6;
2824                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2825                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2826                         if (saddr6->sin6_family == AF_INET6)
2827                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2828                                          &saddr6->sin6_addr, rc);
2829                         else
2830                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2831                                          &saddr4->sin_addr.s_addr, rc);
2832                 }
2833         }
2834         return rc;
2835 }
2836
2837 static int
2838 ip_rfc1001_connect(struct TCP_Server_Info *server)
2839 {
2840         int rc = 0;
2841         /*
2842          * some servers require RFC1001 sessinit before sending
2843          * negprot - BB check reconnection in case where second
2844          * sessinit is sent but no second negprot
2845          */
2846         struct rfc1002_session_packet *ses_init_buf;
2847         unsigned int req_noscope_len;
2848         struct smb_hdr *smb_buf;
2849
2850         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2851                                GFP_KERNEL);
2852
2853         if (ses_init_buf) {
2854                 ses_init_buf->trailer.session_req.called_len = 32;
2855
2856                 if (server->server_RFC1001_name[0] != 0)
2857                         rfc1002mangle(ses_init_buf->trailer.
2858                                       session_req.called_name,
2859                                       server->server_RFC1001_name,
2860                                       RFC1001_NAME_LEN_WITH_NULL);
2861                 else
2862                         rfc1002mangle(ses_init_buf->trailer.
2863                                       session_req.called_name,
2864                                       DEFAULT_CIFS_CALLED_NAME,
2865                                       RFC1001_NAME_LEN_WITH_NULL);
2866
2867                 ses_init_buf->trailer.session_req.calling_len = 32;
2868
2869                 /*
2870                  * calling name ends in null (byte 16) from old smb
2871                  * convention.
2872                  */
2873                 if (server->workstation_RFC1001_name[0] != 0)
2874                         rfc1002mangle(ses_init_buf->trailer.
2875                                       session_req.calling_name,
2876                                       server->workstation_RFC1001_name,
2877                                       RFC1001_NAME_LEN_WITH_NULL);
2878                 else
2879                         rfc1002mangle(ses_init_buf->trailer.
2880                                       session_req.calling_name,
2881                                       "LINUX_CIFS_CLNT",
2882                                       RFC1001_NAME_LEN_WITH_NULL);
2883
2884                 ses_init_buf->trailer.session_req.scope1 = 0;
2885                 ses_init_buf->trailer.session_req.scope2 = 0;
2886                 smb_buf = (struct smb_hdr *)ses_init_buf;
2887
2888                 /* sizeof RFC1002_SESSION_REQUEST with no scopes */
2889                 req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
2890
2891                 /* == cpu_to_be32(0x81000044) */
2892                 smb_buf->smb_buf_length =
2893                         cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
2894                 rc = smb_send(server, smb_buf, 0x44);
2895                 kfree(ses_init_buf);
2896                 /*
2897                  * RFC1001 layer in at least one server
2898                  * requires very short break before negprot
2899                  * presumably because not expecting negprot
2900                  * to follow so fast.  This is a simple
2901                  * solution that works without
2902                  * complicating the code and causes no
2903                  * significant slowing down on mount
2904                  * for everyone else
2905                  */
2906                 usleep_range(1000, 2000);
2907         }
2908         /*
2909          * else the negprot may still work without this
2910          * even though malloc failed
2911          */
2912
2913         return rc;
2914 }
2915
2916 static int
2917 generic_ip_connect(struct TCP_Server_Info *server)
2918 {
2919         int rc = 0;
2920         __be16 sport;
2921         int slen, sfamily;
2922         struct socket *socket = server->ssocket;
2923         struct sockaddr *saddr;
2924
2925         saddr = (struct sockaddr *) &server->dstaddr;
2926
2927         if (server->dstaddr.ss_family == AF_INET6) {
2928                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2929
2930                 sport = ipv6->sin6_port;
2931                 slen = sizeof(struct sockaddr_in6);
2932                 sfamily = AF_INET6;
2933                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2934                                 ntohs(sport));
2935         } else {
2936                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2937
2938                 sport = ipv4->sin_port;
2939                 slen = sizeof(struct sockaddr_in);
2940                 sfamily = AF_INET;
2941                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2942                                 ntohs(sport));
2943         }
2944
2945         if (socket == NULL) {
2946                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2947                                    IPPROTO_TCP, &socket, 1);
2948                 if (rc < 0) {
2949                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2950                         server->ssocket = NULL;
2951                         return rc;
2952                 }
2953
2954                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2955                 cifs_dbg(FYI, "Socket created\n");
2956                 server->ssocket = socket;
2957                 socket->sk->sk_allocation = GFP_NOFS;
2958                 if (sfamily == AF_INET6)
2959                         cifs_reclassify_socket6(socket);
2960                 else
2961                         cifs_reclassify_socket4(socket);
2962         }
2963
2964         rc = bind_socket(server);
2965         if (rc < 0)
2966                 return rc;
2967
2968         /*
2969          * Eventually check for other socket options to change from
2970          * the default. sock_setsockopt not used because it expects
2971          * user space buffer
2972          */
2973         socket->sk->sk_rcvtimeo = 7 * HZ;
2974         socket->sk->sk_sndtimeo = 5 * HZ;
2975
2976         /* make the bufsizes depend on wsize/rsize and max requests */
2977         if (server->noautotune) {
2978                 if (socket->sk->sk_sndbuf < (200 * 1024))
2979                         socket->sk->sk_sndbuf = 200 * 1024;
2980                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2981                         socket->sk->sk_rcvbuf = 140 * 1024;
2982         }
2983
2984         if (server->tcp_nodelay)
2985                 tcp_sock_set_nodelay(socket->sk);
2986
2987         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2988                  socket->sk->sk_sndbuf,
2989                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2990
2991         rc = socket->ops->connect(socket, saddr, slen,
2992                                   server->noblockcnt ? O_NONBLOCK : 0);
2993         /*
2994          * When mounting SMB root file systems, we do not want to block in
2995          * connect. Otherwise bail out and then let cifs_reconnect() perform
2996          * reconnect failover - if possible.
2997          */
2998         if (server->noblockcnt && rc == -EINPROGRESS)
2999                 rc = 0;
3000         if (rc < 0) {
3001                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3002                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3003                 sock_release(socket);
3004                 server->ssocket = NULL;
3005                 return rc;
3006         }
3007         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3008         if (sport == htons(RFC1001_PORT))
3009                 rc = ip_rfc1001_connect(server);
3010
3011         return rc;
3012 }
3013
3014 static int
3015 ip_connect(struct TCP_Server_Info *server)
3016 {
3017         __be16 *sport;
3018         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3019         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3020
3021         if (server->dstaddr.ss_family == AF_INET6)
3022                 sport = &addr6->sin6_port;
3023         else
3024                 sport = &addr->sin_port;
3025
3026         if (*sport == 0) {
3027                 int rc;
3028
3029                 /* try with 445 port at first */
3030                 *sport = htons(CIFS_PORT);
3031
3032                 rc = generic_ip_connect(server);
3033                 if (rc >= 0)
3034                         return rc;
3035
3036                 /* if it failed, try with 139 port */
3037                 *sport = htons(RFC1001_PORT);
3038         }
3039
3040         return generic_ip_connect(server);
3041 }
3042
3043 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3044 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3045                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3046 {
3047         /*
3048          * If we are reconnecting then should we check to see if
3049          * any requested capabilities changed locally e.g. via
3050          * remount but we can not do much about it here
3051          * if they have (even if we could detect it by the following)
3052          * Perhaps we could add a backpointer to array of sb from tcon
3053          * or if we change to make all sb to same share the same
3054          * sb as NFS - then we only have one backpointer to sb.
3055          * What if we wanted to mount the server share twice once with
3056          * and once without posixacls or posix paths?
3057          */
3058         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3059
3060         if (ctx && ctx->no_linux_ext) {
3061                 tcon->fsUnixInfo.Capability = 0;
3062                 tcon->unix_ext = 0; /* Unix Extensions disabled */
3063                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3064                 return;
3065         } else if (ctx)
3066                 tcon->unix_ext = 1; /* Unix Extensions supported */
3067
3068         if (!tcon->unix_ext) {
3069                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3070                 return;
3071         }
3072
3073         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3074                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3075                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3076                 /*
3077                  * check for reconnect case in which we do not
3078                  * want to change the mount behavior if we can avoid it
3079                  */
3080                 if (ctx == NULL) {
3081                         /*
3082                          * turn off POSIX ACL and PATHNAMES if not set
3083                          * originally at mount time
3084                          */
3085                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3086                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3087                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3088                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3089                                         cifs_dbg(VFS, "POSIXPATH support change\n");
3090                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3091                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3092                                 cifs_dbg(VFS, "possible reconnect error\n");
3093                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
3094                         }
3095                 }
3096
3097                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3098                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
3099
3100                 cap &= CIFS_UNIX_CAP_MASK;
3101                 if (ctx && ctx->no_psx_acl)
3102                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3103                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3104                         cifs_dbg(FYI, "negotiated posix acl support\n");
3105                         if (cifs_sb)
3106                                 cifs_sb->mnt_cifs_flags |=
3107                                         CIFS_MOUNT_POSIXACL;
3108                 }
3109
3110                 if (ctx && ctx->posix_paths == 0)
3111                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3112                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3113                         cifs_dbg(FYI, "negotiate posix pathnames\n");
3114                         if (cifs_sb)
3115                                 cifs_sb->mnt_cifs_flags |=
3116                                         CIFS_MOUNT_POSIX_PATHS;
3117                 }
3118
3119                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3120 #ifdef CONFIG_CIFS_DEBUG2
3121                 if (cap & CIFS_UNIX_FCNTL_CAP)
3122                         cifs_dbg(FYI, "FCNTL cap\n");
3123                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3124                         cifs_dbg(FYI, "EXTATTR cap\n");
3125                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3126                         cifs_dbg(FYI, "POSIX path cap\n");
3127                 if (cap & CIFS_UNIX_XATTR_CAP)
3128                         cifs_dbg(FYI, "XATTR cap\n");
3129                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3130                         cifs_dbg(FYI, "POSIX ACL cap\n");
3131                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3132                         cifs_dbg(FYI, "very large read cap\n");
3133                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3134                         cifs_dbg(FYI, "very large write cap\n");
3135                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3136                         cifs_dbg(FYI, "transport encryption cap\n");
3137                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3138                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3139 #endif /* CIFS_DEBUG2 */
3140                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3141                         if (ctx == NULL)
3142                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3143                         else
3144                                 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");
3145
3146                 }
3147         }
3148 }
3149 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3150
3151 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3152 {
3153         struct smb3_fs_context *ctx = cifs_sb->ctx;
3154
3155         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3156
3157         spin_lock_init(&cifs_sb->tlink_tree_lock);
3158         cifs_sb->tlink_tree = RB_ROOT;
3159
3160         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3161                  ctx->file_mode, ctx->dir_mode);
3162
3163         /* this is needed for ASCII cp to Unicode converts */
3164         if (ctx->iocharset == NULL) {
3165                 /* load_nls_default cannot return null */
3166                 cifs_sb->local_nls = load_nls_default();
3167         } else {
3168                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3169                 if (cifs_sb->local_nls == NULL) {
3170                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3171                                  ctx->iocharset);
3172                         return -ELIBACC;
3173                 }
3174         }
3175         ctx->local_nls = cifs_sb->local_nls;
3176
3177         smb3_update_mnt_flags(cifs_sb);
3178
3179         if (ctx->direct_io)
3180                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3181         if (ctx->cache_ro) {
3182                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3183                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3184         } else if (ctx->cache_rw) {
3185                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3186                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3187                                             CIFS_MOUNT_RW_CACHE);
3188         }
3189
3190         if ((ctx->cifs_acl) && (ctx->dynperm))
3191                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3192
3193         if (ctx->prepath) {
3194                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3195                 if (cifs_sb->prepath == NULL)
3196                         return -ENOMEM;
3197                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3198         }
3199
3200         return 0;
3201 }
3202
3203 /* Release all succeed connections */
3204 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
3205 {
3206         int rc = 0;
3207
3208         if (mnt_ctx->tcon)
3209                 cifs_put_tcon(mnt_ctx->tcon);
3210         else if (mnt_ctx->ses)
3211                 cifs_put_smb_ses(mnt_ctx->ses);
3212         else if (mnt_ctx->server)
3213                 cifs_put_tcp_session(mnt_ctx->server, 0);
3214         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3215         free_xid(mnt_ctx->xid);
3216 }
3217
3218 /* Get connections for tcp, ses and tcon */
3219 static int mount_get_conns(struct mount_ctx *mnt_ctx)
3220 {
3221         int rc = 0;
3222         struct TCP_Server_Info *server = NULL;
3223         struct cifs_ses *ses = NULL;
3224         struct cifs_tcon *tcon = NULL;
3225         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3226         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3227         unsigned int xid;
3228
3229         xid = get_xid();
3230
3231         /* get a reference to a tcp session */
3232         server = cifs_get_tcp_session(ctx, NULL);
3233         if (IS_ERR(server)) {
3234                 rc = PTR_ERR(server);
3235                 server = NULL;
3236                 goto out;
3237         }
3238
3239         /* get a reference to a SMB session */
3240         ses = cifs_get_smb_ses(server, ctx);
3241         if (IS_ERR(ses)) {
3242                 rc = PTR_ERR(ses);
3243                 ses = NULL;
3244                 goto out;
3245         }
3246
3247         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3248                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3249                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3250                 rc = -EOPNOTSUPP;
3251                 goto out;
3252         }
3253
3254         /* search for existing tcon to this server share */
3255         tcon = cifs_get_tcon(ses, ctx);
3256         if (IS_ERR(tcon)) {
3257                 rc = PTR_ERR(tcon);
3258                 tcon = NULL;
3259                 goto out;
3260         }
3261
3262         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3263         if (tcon->posix_extensions)
3264                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3265
3266 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3267         /* tell server which Unix caps we support */
3268         if (cap_unix(tcon->ses)) {
3269                 /*
3270                  * reset of caps checks mount to see if unix extensions disabled
3271                  * for just this mount.
3272                  */
3273                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3274                 spin_lock(&tcon->ses->server->srv_lock);
3275                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3276                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3277                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3278                         spin_unlock(&tcon->ses->server->srv_lock);
3279                         rc = -EACCES;
3280                         goto out;
3281                 }
3282                 spin_unlock(&tcon->ses->server->srv_lock);
3283         } else
3284 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3285                 tcon->unix_ext = 0; /* server does not support them */
3286
3287         /* do not care if a following call succeed - informational */
3288         if (!tcon->pipe && server->ops->qfs_tcon) {
3289                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3290                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3291                         if (tcon->fsDevInfo.DeviceCharacteristics &
3292                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3293                                 cifs_dbg(VFS, "mounted to read only share\n");
3294                         else if ((cifs_sb->mnt_cifs_flags &
3295                                   CIFS_MOUNT_RW_CACHE) == 0)
3296                                 cifs_dbg(VFS, "read only mount of RW share\n");
3297                         /* no need to log a RW mount of a typical RW share */
3298                 }
3299         }
3300
3301         /*
3302          * Clamp the rsize/wsize mount arguments if they are too big for the server
3303          * and set the rsize/wsize to the negotiated values if not passed in by
3304          * the user on mount
3305          */
3306         if ((cifs_sb->ctx->wsize == 0) ||
3307             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3308                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3309         if ((cifs_sb->ctx->rsize == 0) ||
3310             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3311                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3312
3313         /*
3314          * The cookie is initialized from volume info returned above.
3315          * Inside cifs_fscache_get_super_cookie it checks
3316          * that we do not get super cookie twice.
3317          */
3318         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3319                 cifs_fscache_get_super_cookie(tcon);
3320
3321 out:
3322         mnt_ctx->server = server;
3323         mnt_ctx->ses = ses;
3324         mnt_ctx->tcon = tcon;
3325         mnt_ctx->xid = xid;
3326
3327         return rc;
3328 }
3329
3330 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3331                              struct cifs_tcon *tcon)
3332 {
3333         struct tcon_link *tlink;
3334
3335         /* hang the tcon off of the superblock */
3336         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3337         if (tlink == NULL)
3338                 return -ENOMEM;
3339
3340         tlink->tl_uid = ses->linux_uid;
3341         tlink->tl_tcon = tcon;
3342         tlink->tl_time = jiffies;
3343         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3344         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3345
3346         cifs_sb->master_tlink = tlink;
3347         spin_lock(&cifs_sb->tlink_tree_lock);
3348         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3349         spin_unlock(&cifs_sb->tlink_tree_lock);
3350
3351         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3352                                 TLINK_IDLE_EXPIRE);
3353         return 0;
3354 }
3355
3356 #ifdef CONFIG_CIFS_DFS_UPCALL
3357 /* Get unique dfs connections */
3358 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3359 {
3360         int rc;
3361
3362         mnt_ctx->fs_ctx->nosharesock = true;
3363         rc = mount_get_conns(mnt_ctx);
3364         if (mnt_ctx->server) {
3365                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3366                 spin_lock(&mnt_ctx->server->srv_lock);
3367                 mnt_ctx->server->is_dfs_conn = true;
3368                 spin_unlock(&mnt_ctx->server->srv_lock);
3369         }
3370         return rc;
3371 }
3372
3373 /*
3374  * cifs_build_path_to_root returns full path to root when we do not have an
3375  * existing connection (tcon)
3376  */
3377 static char *
3378 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3379                        const struct cifs_sb_info *cifs_sb, bool useppath)
3380 {
3381         char *full_path, *pos;
3382         unsigned int pplen = useppath && ctx->prepath ?
3383                 strlen(ctx->prepath) + 1 : 0;
3384         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3385
3386         if (unc_len > MAX_TREE_SIZE)
3387                 return ERR_PTR(-EINVAL);
3388
3389         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3390         if (full_path == NULL)
3391                 return ERR_PTR(-ENOMEM);
3392
3393         memcpy(full_path, ctx->UNC, unc_len);
3394         pos = full_path + unc_len;
3395
3396         if (pplen) {
3397                 *pos = CIFS_DIR_SEP(cifs_sb);
3398                 memcpy(pos + 1, ctx->prepath, pplen);
3399                 pos += pplen;
3400         }
3401
3402         *pos = '\0'; /* add trailing null */
3403         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3404         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3405         return full_path;
3406 }
3407
3408 /*
3409  * expand_dfs_referral - Update cifs_sb from dfs referral path
3410  *
3411  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3412  * submount.  Otherwise it will be left untouched.
3413  */
3414 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3415                                struct dfs_info3_param *referral)
3416 {
3417         int rc;
3418         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3419         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3420         char *fake_devname = NULL, *mdata = NULL;
3421
3422         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3423                                            &fake_devname);
3424         if (IS_ERR(mdata)) {
3425                 rc = PTR_ERR(mdata);
3426                 mdata = NULL;
3427         } else {
3428                 /*
3429                  * We can not clear out the whole structure since we no longer have an explicit
3430                  * function to parse a mount-string. Instead we need to clear out the individual
3431                  * fields that are no longer valid.
3432                  */
3433                 kfree(ctx->prepath);
3434                 ctx->prepath = NULL;
3435                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3436         }
3437         kfree(fake_devname);
3438         kfree(cifs_sb->ctx->mount_options);
3439         cifs_sb->ctx->mount_options = mdata;
3440
3441         return rc;
3442 }
3443 #endif
3444
3445 /* TODO: all callers to this are broken. We are not parsing mount_options here
3446  * we should pass a clone of the original context?
3447  */
3448 int
3449 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3450 {
3451         int rc;
3452
3453         if (devname) {
3454                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3455                 rc = smb3_parse_devname(devname, ctx);
3456                 if (rc) {
3457                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3458                         return rc;
3459                 }
3460         }
3461
3462         if (mntopts) {
3463                 char *ip;
3464
3465                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3466                 if (rc) {
3467                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3468                         return rc;
3469                 }
3470
3471                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3472                 kfree(ip);
3473                 if (!rc) {
3474                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3475                         return -EINVAL;
3476                 }
3477         }
3478
3479         if (ctx->nullauth) {
3480                 cifs_dbg(FYI, "Anonymous login\n");
3481                 kfree(ctx->username);
3482                 ctx->username = NULL;
3483         } else if (ctx->username) {
3484                 /* BB fixme parse for domain name here */
3485                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3486         } else {
3487                 cifs_dbg(VFS, "No username specified\n");
3488         /* In userspace mount helper we can get user name from alternate
3489            locations such as env variables and files on disk */
3490                 return -EINVAL;
3491         }
3492
3493         return 0;
3494 }
3495
3496 static int
3497 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3498                                         unsigned int xid,
3499                                         struct cifs_tcon *tcon,
3500                                         struct cifs_sb_info *cifs_sb,
3501                                         char *full_path,
3502                                         int added_treename)
3503 {
3504         int rc;
3505         char *s;
3506         char sep, tmp;
3507         int skip = added_treename ? 1 : 0;
3508
3509         sep = CIFS_DIR_SEP(cifs_sb);
3510         s = full_path;
3511
3512         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3513         while (rc == 0) {
3514                 /* skip separators */
3515                 while (*s == sep)
3516                         s++;
3517                 if (!*s)
3518                         break;
3519                 /* next separator */
3520                 while (*s && *s != sep)
3521                         s++;
3522                 /*
3523                  * if the treename is added, we then have to skip the first
3524                  * part within the separators
3525                  */
3526                 if (skip) {
3527                         skip = 0;
3528                         continue;
3529                 }
3530                 /*
3531                  * temporarily null-terminate the path at the end of
3532                  * the current component
3533                  */
3534                 tmp = *s;
3535                 *s = 0;
3536                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3537                                                      full_path);
3538                 *s = tmp;
3539         }
3540         return rc;
3541 }
3542
3543 /*
3544  * Check if path is remote (i.e. a DFS share).
3545  *
3546  * Return -EREMOTE if it is, otherwise 0 or -errno.
3547  */
3548 static int is_path_remote(struct mount_ctx *mnt_ctx)
3549 {
3550         int rc;
3551         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3552         struct TCP_Server_Info *server = mnt_ctx->server;
3553         unsigned int xid = mnt_ctx->xid;
3554         struct cifs_tcon *tcon = mnt_ctx->tcon;
3555         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3556         char *full_path;
3557 #ifdef CONFIG_CIFS_DFS_UPCALL
3558         bool nodfs = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS;
3559 #endif
3560
3561         if (!server->ops->is_path_accessible)
3562                 return -EOPNOTSUPP;
3563
3564         /*
3565          * cifs_build_path_to_root works only when we have a valid tcon
3566          */
3567         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3568                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3569         if (full_path == NULL)
3570                 return -ENOMEM;
3571
3572         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3573
3574         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3575                                              full_path);
3576 #ifdef CONFIG_CIFS_DFS_UPCALL
3577         if (nodfs) {
3578                 if (rc == -EREMOTE)
3579                         rc = -EOPNOTSUPP;
3580                 goto out;
3581         }
3582
3583         /* path *might* exist with non-ASCII characters in DFS root
3584          * try again with full path (only if nodfs is not set) */
3585         if (rc == -ENOENT && is_tcon_dfs(tcon))
3586                 rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
3587                                                         full_path);
3588 #endif
3589         if (rc != 0 && rc != -EREMOTE)
3590                 goto out;
3591
3592         if (rc != -EREMOTE) {
3593                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3594                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3595                 if (rc != 0) {
3596                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3597                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3598                         rc = 0;
3599                 }
3600         }
3601
3602 out:
3603         kfree(full_path);
3604         return rc;
3605 }
3606
3607 #ifdef CONFIG_CIFS_DFS_UPCALL
3608 static void set_root_ses(struct mount_ctx *mnt_ctx)
3609 {
3610         if (mnt_ctx->ses) {
3611                 spin_lock(&cifs_tcp_ses_lock);
3612                 mnt_ctx->ses->ses_count++;
3613                 spin_unlock(&cifs_tcp_ses_lock);
3614                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3615         }
3616         mnt_ctx->root_ses = mnt_ctx->ses;
3617 }
3618
3619 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3620 {
3621         int rc;
3622         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3623         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3624
3625         *isdfs = true;
3626
3627         rc = mount_get_conns(mnt_ctx);
3628         /*
3629          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3630          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3631          *
3632          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3633          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3634          */
3635         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3636             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3637                            ctx->UNC + 1, NULL, root_tl)) {
3638                 if (rc)
3639                         return rc;
3640                 /* Check if it is fully accessible and then mount it */
3641                 rc = is_path_remote(mnt_ctx);
3642                 if (!rc)
3643                         *isdfs = false;
3644                 else if (rc != -EREMOTE)
3645                         return rc;
3646         }
3647         return 0;
3648 }
3649
3650 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3651                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3652 {
3653         int rc;
3654         struct dfs_info3_param ref = {};
3655         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3656         char *oldmnt = cifs_sb->ctx->mount_options;
3657
3658         cifs_dbg(FYI, "%s: full_path=%s ref_path=%s target=%s\n", __func__, full_path, ref_path,
3659                  dfs_cache_get_tgt_name(tit));
3660
3661         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3662         if (rc)
3663                 goto out;
3664
3665         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3666         if (rc)
3667                 goto out;
3668
3669         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3670         if (oldmnt != cifs_sb->ctx->mount_options) {
3671                 mount_put_conns(mnt_ctx);
3672                 rc = mount_get_dfs_conns(mnt_ctx);
3673         }
3674         if (!rc) {
3675                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3676                         set_root_ses(mnt_ctx);
3677                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3678                                               cifs_remap(cifs_sb), ref_path, tit);
3679         }
3680
3681 out:
3682         free_dfs_info_param(&ref);
3683         return rc;
3684 }
3685
3686 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3687 {
3688         int rc;
3689         char *full_path;
3690         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3691         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3692         struct dfs_cache_tgt_iterator *tit;
3693
3694         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3695          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3696          * now on.
3697          */
3698         mount_put_conns(mnt_ctx);
3699         mount_get_dfs_conns(mnt_ctx);
3700         set_root_ses(mnt_ctx);
3701
3702         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3703         if (IS_ERR(full_path))
3704                 return PTR_ERR(full_path);
3705
3706         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3707                                                             cifs_remap(cifs_sb));
3708         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3709                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3710                 mnt_ctx->origin_fullpath = NULL;
3711                 goto out;
3712         }
3713
3714         /* Try all dfs root targets */
3715         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3716              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3717                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3718                 if (!rc) {
3719                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3720                         if (!mnt_ctx->leaf_fullpath)
3721                                 rc = -ENOMEM;
3722                         break;
3723                 }
3724         }
3725
3726 out:
3727         kfree(full_path);
3728         return rc;
3729 }
3730
3731 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3732 {
3733         int rc;
3734         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3735         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3736         char *full_path;
3737         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3738         struct dfs_cache_tgt_iterator *tit;
3739
3740         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3741         if (IS_ERR(full_path))
3742                 return PTR_ERR(full_path);
3743
3744         kfree(mnt_ctx->leaf_fullpath);
3745         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3746                                                           cifs_remap(cifs_sb));
3747         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3748                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3749                 mnt_ctx->leaf_fullpath = NULL;
3750                 goto out;
3751         }
3752
3753         /* Get referral from dfs link */
3754         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3755                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3756         if (rc)
3757                 goto out;
3758
3759         /* Try all dfs link targets.  If an I/O fails from currently connected DFS target with an
3760          * error other than STATUS_PATH_NOT_COVERED (-EREMOTE), then retry it from other targets as
3761          * specified in MS-DFSC "3.1.5.2 I/O Operation to Target Fails with an Error Other Than
3762          * STATUS_PATH_NOT_COVERED."
3763          */
3764         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3765              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3766                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3767                 if (!rc) {
3768                         rc = is_path_remote(mnt_ctx);
3769                         if (!rc || rc == -EREMOTE)
3770                                 break;
3771                 }
3772         }
3773
3774 out:
3775         kfree(full_path);
3776         dfs_cache_free_tgts(&tl);
3777         return rc;
3778 }
3779
3780 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3781 {
3782         int rc;
3783         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3784         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3785         char *full_path;
3786         int num_links = 0;
3787
3788         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3789         if (IS_ERR(full_path))
3790                 return PTR_ERR(full_path);
3791
3792         kfree(mnt_ctx->origin_fullpath);
3793         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3794                                                             cifs_remap(cifs_sb));
3795         kfree(full_path);
3796
3797         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3798                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3799                 mnt_ctx->origin_fullpath = NULL;
3800                 return rc;
3801         }
3802
3803         do {
3804                 rc = __follow_dfs_link(mnt_ctx);
3805                 if (!rc || rc != -EREMOTE)
3806                         break;
3807         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3808
3809         return rc;
3810 }
3811
3812 /* Set up DFS referral paths for failover */
3813 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3814 {
3815         struct TCP_Server_Info *server = mnt_ctx->server;
3816
3817         mutex_lock(&server->refpath_lock);
3818         server->origin_fullpath = mnt_ctx->origin_fullpath;
3819         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3820         server->current_fullpath = mnt_ctx->leaf_fullpath;
3821         mutex_unlock(&server->refpath_lock);
3822         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3823 }
3824
3825 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3826 {
3827         int rc;
3828         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3829         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3830         bool isdfs;
3831
3832         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3833         if (rc)
3834                 goto error;
3835         if (!isdfs)
3836                 goto out;
3837
3838         /* proceed as DFS mount */
3839         uuid_gen(&mnt_ctx.mount_id);
3840         rc = connect_dfs_root(&mnt_ctx, &tl);
3841         dfs_cache_free_tgts(&tl);
3842
3843         if (rc)
3844                 goto error;
3845
3846         rc = is_path_remote(&mnt_ctx);
3847         if (rc)
3848                 rc = follow_dfs_link(&mnt_ctx);
3849         if (rc)
3850                 goto error;
3851
3852         setup_server_referral_paths(&mnt_ctx);
3853         /*
3854          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3855          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3856          */
3857         cifs_autodisable_serverino(cifs_sb);
3858         /*
3859          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3860          * that have different prefix paths.
3861          */
3862         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3863         kfree(cifs_sb->prepath);
3864         cifs_sb->prepath = ctx->prepath;
3865         ctx->prepath = NULL;
3866         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3867
3868 out:
3869         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3870         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3871         if (rc)
3872                 goto error;
3873
3874         free_xid(mnt_ctx.xid);
3875         return rc;
3876
3877 error:
3878         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3879         kfree(mnt_ctx.origin_fullpath);
3880         kfree(mnt_ctx.leaf_fullpath);
3881         mount_put_conns(&mnt_ctx);
3882         return rc;
3883 }
3884 #else
3885 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3886 {
3887         int rc = 0;
3888         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3889
3890         rc = mount_get_conns(&mnt_ctx);
3891         if (rc)
3892                 goto error;
3893
3894         if (mnt_ctx.tcon) {
3895                 rc = is_path_remote(&mnt_ctx);
3896                 if (rc == -EREMOTE)
3897                         rc = -EOPNOTSUPP;
3898                 if (rc)
3899                         goto error;
3900         }
3901
3902         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3903         if (rc)
3904                 goto error;
3905
3906         free_xid(mnt_ctx.xid);
3907         return rc;
3908
3909 error:
3910         mount_put_conns(&mnt_ctx);
3911         return rc;
3912 }
3913 #endif
3914
3915 /*
3916  * Issue a TREE_CONNECT request.
3917  */
3918 int
3919 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3920          const char *tree, struct cifs_tcon *tcon,
3921          const struct nls_table *nls_codepage)
3922 {
3923         struct smb_hdr *smb_buffer;
3924         struct smb_hdr *smb_buffer_response;
3925         TCONX_REQ *pSMB;
3926         TCONX_RSP *pSMBr;
3927         unsigned char *bcc_ptr;
3928         int rc = 0;
3929         int length;
3930         __u16 bytes_left, count;
3931
3932         if (ses == NULL)
3933                 return -EIO;
3934
3935         smb_buffer = cifs_buf_get();
3936         if (smb_buffer == NULL)
3937                 return -ENOMEM;
3938
3939         smb_buffer_response = smb_buffer;
3940
3941         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3942                         NULL /*no tid */ , 4 /*wct */ );
3943
3944         smb_buffer->Mid = get_next_mid(ses->server);
3945         smb_buffer->Uid = ses->Suid;
3946         pSMB = (TCONX_REQ *) smb_buffer;
3947         pSMBr = (TCONX_RSP *) smb_buffer_response;
3948
3949         pSMB->AndXCommand = 0xFF;
3950         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3951         bcc_ptr = &pSMB->Password[0];
3952
3953         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3954         *bcc_ptr = 0; /* password is null byte */
3955         bcc_ptr++;              /* skip password */
3956         /* already aligned so no need to do it below */
3957
3958         if (ses->server->sign)
3959                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3960
3961         if (ses->capabilities & CAP_STATUS32) {
3962                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3963         }
3964         if (ses->capabilities & CAP_DFS) {
3965                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3966         }
3967         if (ses->capabilities & CAP_UNICODE) {
3968                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3969                 length =
3970                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3971                         6 /* max utf8 char length in bytes */ *
3972                         (/* server len*/ + 256 /* share len */), nls_codepage);
3973                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3974                 bcc_ptr += 2;   /* skip trailing null */
3975         } else {                /* ASCII */
3976                 strcpy(bcc_ptr, tree);
3977                 bcc_ptr += strlen(tree) + 1;
3978         }
3979         strcpy(bcc_ptr, "?????");
3980         bcc_ptr += strlen("?????");
3981         bcc_ptr += 1;
3982         count = bcc_ptr - &pSMB->Password[0];
3983         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3984         pSMB->ByteCount = cpu_to_le16(count);
3985
3986         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3987                          0);
3988
3989         /* above now done in SendReceive */
3990         if (rc == 0) {
3991                 bool is_unicode;
3992
3993                 tcon->tid = smb_buffer_response->Tid;
3994                 bcc_ptr = pByteArea(smb_buffer_response);
3995                 bytes_left = get_bcc(smb_buffer_response);
3996                 length = strnlen(bcc_ptr, bytes_left - 2);
3997                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3998                         is_unicode = true;
3999                 else
4000                         is_unicode = false;
4001
4002
4003                 /* skip service field (NB: this field is always ASCII) */
4004                 if (length == 3) {
4005                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
4006                             (bcc_ptr[2] == 'C')) {
4007                                 cifs_dbg(FYI, "IPC connection\n");
4008                                 tcon->ipc = true;
4009                                 tcon->pipe = true;
4010                         }
4011                 } else if (length == 2) {
4012                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
4013                                 /* the most common case */
4014                                 cifs_dbg(FYI, "disk share connection\n");
4015                         }
4016                 }
4017                 bcc_ptr += length + 1;
4018                 bytes_left -= (length + 1);
4019                 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
4020
4021                 /* mostly informational -- no need to fail on error here */
4022                 kfree(tcon->nativeFileSystem);
4023                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
4024                                                       bytes_left, is_unicode,
4025                                                       nls_codepage);
4026
4027                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
4028
4029                 if ((smb_buffer_response->WordCount == 3) ||
4030                          (smb_buffer_response->WordCount == 7))
4031                         /* field is in same location */
4032                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
4033                 else
4034                         tcon->Flags = 0;
4035                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
4036         }
4037
4038         cifs_buf_release(smb_buffer);
4039         return rc;
4040 }
4041
4042 static void delayed_free(struct rcu_head *p)
4043 {
4044         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
4045
4046         unload_nls(cifs_sb->local_nls);
4047         smb3_cleanup_fs_context(cifs_sb->ctx);
4048         kfree(cifs_sb);
4049 }
4050
4051 void
4052 cifs_umount(struct cifs_sb_info *cifs_sb)
4053 {
4054         struct rb_root *root = &cifs_sb->tlink_tree;
4055         struct rb_node *node;
4056         struct tcon_link *tlink;
4057
4058         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
4059
4060         spin_lock(&cifs_sb->tlink_tree_lock);
4061         while ((node = rb_first(root))) {
4062                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4063                 cifs_get_tlink(tlink);
4064                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4065                 rb_erase(node, root);
4066
4067                 spin_unlock(&cifs_sb->tlink_tree_lock);
4068                 cifs_put_tlink(tlink);
4069                 spin_lock(&cifs_sb->tlink_tree_lock);
4070         }
4071         spin_unlock(&cifs_sb->tlink_tree_lock);
4072
4073         kfree(cifs_sb->prepath);
4074 #ifdef CONFIG_CIFS_DFS_UPCALL
4075         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
4076 #endif
4077         call_rcu(&cifs_sb->rcu, delayed_free);
4078 }
4079
4080 int
4081 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
4082                         struct TCP_Server_Info *server)
4083 {
4084         int rc = 0;
4085
4086         if (!server->ops->need_neg || !server->ops->negotiate)
4087                 return -ENOSYS;
4088
4089         /* only send once per connect */
4090         spin_lock(&server->srv_lock);
4091         if (!server->ops->need_neg(server) ||
4092             server->tcpStatus != CifsNeedNegotiate) {
4093                 spin_unlock(&server->srv_lock);
4094                 return 0;
4095         }
4096         server->tcpStatus = CifsInNegotiate;
4097         spin_unlock(&server->srv_lock);
4098
4099         rc = server->ops->negotiate(xid, ses, server);
4100         if (rc == 0) {
4101                 spin_lock(&server->srv_lock);
4102                 if (server->tcpStatus == CifsInNegotiate)
4103                         server->tcpStatus = CifsGood;
4104                 else
4105                         rc = -EHOSTDOWN;
4106                 spin_unlock(&server->srv_lock);
4107         } else {
4108                 spin_lock(&server->srv_lock);
4109                 if (server->tcpStatus == CifsInNegotiate)
4110                         server->tcpStatus = CifsNeedNegotiate;
4111                 spin_unlock(&server->srv_lock);
4112         }
4113
4114         return rc;
4115 }
4116
4117 int
4118 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
4119                    struct TCP_Server_Info *server,
4120                    struct nls_table *nls_info)
4121 {
4122         int rc = -ENOSYS;
4123         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
4124         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
4125         bool is_binding = false;
4126
4127         spin_lock(&ses->ses_lock);
4128         if (server->dstaddr.ss_family == AF_INET6)
4129                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
4130         else
4131                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
4132
4133         if (ses->ses_status != SES_GOOD &&
4134             ses->ses_status != SES_NEW &&
4135             ses->ses_status != SES_NEED_RECON) {
4136                 spin_unlock(&ses->ses_lock);
4137                 return 0;
4138         }
4139
4140         /* only send once per connect */
4141         spin_lock(&ses->chan_lock);
4142         if (CIFS_ALL_CHANS_GOOD(ses) ||
4143             cifs_chan_in_reconnect(ses, server)) {
4144                 spin_unlock(&ses->chan_lock);
4145                 spin_unlock(&ses->ses_lock);
4146                 return 0;
4147         }
4148         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
4149         cifs_chan_set_in_reconnect(ses, server);
4150         spin_unlock(&ses->chan_lock);
4151
4152         if (!is_binding)
4153                 ses->ses_status = SES_IN_SETUP;
4154         spin_unlock(&ses->ses_lock);
4155
4156         if (!is_binding) {
4157                 ses->capabilities = server->capabilities;
4158                 if (!linuxExtEnabled)
4159                         ses->capabilities &= (~server->vals->cap_unix);
4160
4161                 if (ses->auth_key.response) {
4162                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
4163                                  ses->auth_key.response);
4164                         kfree_sensitive(ses->auth_key.response);
4165                         ses->auth_key.response = NULL;
4166                         ses->auth_key.len = 0;
4167                 }
4168         }
4169
4170         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
4171                  server->sec_mode, server->capabilities, server->timeAdj);
4172
4173         if (server->ops->sess_setup)
4174                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
4175
4176         if (rc) {
4177                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
4178                 spin_lock(&ses->ses_lock);
4179                 if (ses->ses_status == SES_IN_SETUP)
4180                         ses->ses_status = SES_NEED_RECON;
4181                 spin_lock(&ses->chan_lock);
4182                 cifs_chan_clear_in_reconnect(ses, server);
4183                 spin_unlock(&ses->chan_lock);
4184                 spin_unlock(&ses->ses_lock);
4185         } else {
4186                 spin_lock(&ses->ses_lock);
4187                 if (ses->ses_status == SES_IN_SETUP)
4188                         ses->ses_status = SES_GOOD;
4189                 spin_lock(&ses->chan_lock);
4190                 cifs_chan_clear_in_reconnect(ses, server);
4191                 cifs_chan_clear_need_reconnect(ses, server);
4192                 spin_unlock(&ses->chan_lock);
4193                 spin_unlock(&ses->ses_lock);
4194         }
4195
4196         return rc;
4197 }
4198
4199 static int
4200 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
4201 {
4202         ctx->sectype = ses->sectype;
4203
4204         /* krb5 is special, since we don't need username or pw */
4205         if (ctx->sectype == Kerberos)
4206                 return 0;
4207
4208         return cifs_set_cifscreds(ctx, ses);
4209 }
4210
4211 static struct cifs_tcon *
4212 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
4213 {
4214         int rc;
4215         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
4216         struct cifs_ses *ses;
4217         struct cifs_tcon *tcon = NULL;
4218         struct smb3_fs_context *ctx;
4219
4220         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4221         if (ctx == NULL)
4222                 return ERR_PTR(-ENOMEM);
4223
4224         ctx->local_nls = cifs_sb->local_nls;
4225         ctx->linux_uid = fsuid;
4226         ctx->cred_uid = fsuid;
4227         ctx->UNC = master_tcon->tree_name;
4228         ctx->retry = master_tcon->retry;
4229         ctx->nocase = master_tcon->nocase;
4230         ctx->nohandlecache = master_tcon->nohandlecache;
4231         ctx->local_lease = master_tcon->local_lease;
4232         ctx->no_lease = master_tcon->no_lease;
4233         ctx->resilient = master_tcon->use_resilient;
4234         ctx->persistent = master_tcon->use_persistent;
4235         ctx->handle_timeout = master_tcon->handle_timeout;
4236         ctx->no_linux_ext = !master_tcon->unix_ext;
4237         ctx->linux_ext = master_tcon->posix_extensions;
4238         ctx->sectype = master_tcon->ses->sectype;
4239         ctx->sign = master_tcon->ses->sign;
4240         ctx->seal = master_tcon->seal;
4241         ctx->witness = master_tcon->use_witness;
4242
4243         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4244         if (rc) {
4245                 tcon = ERR_PTR(rc);
4246                 goto out;
4247         }
4248
4249         /* get a reference for the same TCP session */
4250         spin_lock(&cifs_tcp_ses_lock);
4251         ++master_tcon->ses->server->srv_count;
4252         spin_unlock(&cifs_tcp_ses_lock);
4253
4254         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4255         if (IS_ERR(ses)) {
4256                 tcon = (struct cifs_tcon *)ses;
4257                 cifs_put_tcp_session(master_tcon->ses->server, 0);
4258                 goto out;
4259         }
4260
4261         tcon = cifs_get_tcon(ses, ctx);
4262         if (IS_ERR(tcon)) {
4263                 cifs_put_smb_ses(ses);
4264                 goto out;
4265         }
4266
4267 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
4268         if (cap_unix(ses))
4269                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4270 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
4271
4272 out:
4273         kfree(ctx->username);
4274         kfree_sensitive(ctx->password);
4275         kfree(ctx);
4276
4277         return tcon;
4278 }
4279
4280 struct cifs_tcon *
4281 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4282 {
4283         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4284 }
4285
4286 /* find and return a tlink with given uid */
4287 static struct tcon_link *
4288 tlink_rb_search(struct rb_root *root, kuid_t uid)
4289 {
4290         struct rb_node *node = root->rb_node;
4291         struct tcon_link *tlink;
4292
4293         while (node) {
4294                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4295
4296                 if (uid_gt(tlink->tl_uid, uid))
4297                         node = node->rb_left;
4298                 else if (uid_lt(tlink->tl_uid, uid))
4299                         node = node->rb_right;
4300                 else
4301                         return tlink;
4302         }
4303         return NULL;
4304 }
4305
4306 /* insert a tcon_link into the tree */
4307 static void
4308 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4309 {
4310         struct rb_node **new = &(root->rb_node), *parent = NULL;
4311         struct tcon_link *tlink;
4312
4313         while (*new) {
4314                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4315                 parent = *new;
4316
4317                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4318                         new = &((*new)->rb_left);
4319                 else
4320                         new = &((*new)->rb_right);
4321         }
4322
4323         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4324         rb_insert_color(&new_tlink->tl_rbnode, root);
4325 }
4326
4327 /*
4328  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4329  * current task.
4330  *
4331  * If the superblock doesn't refer to a multiuser mount, then just return
4332  * the master tcon for the mount.
4333  *
4334  * First, search the rbtree for an existing tcon for this fsuid. If one
4335  * exists, then check to see if it's pending construction. If it is then wait
4336  * for construction to complete. Once it's no longer pending, check to see if
4337  * it failed and either return an error or retry construction, depending on
4338  * the timeout.
4339  *
4340  * If one doesn't exist then insert a new tcon_link struct into the tree and
4341  * try to construct a new one.
4342  */
4343 struct tcon_link *
4344 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4345 {
4346         int ret;
4347         kuid_t fsuid = current_fsuid();
4348         struct tcon_link *tlink, *newtlink;
4349
4350         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4351                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4352
4353         spin_lock(&cifs_sb->tlink_tree_lock);
4354         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4355         if (tlink)
4356                 cifs_get_tlink(tlink);
4357         spin_unlock(&cifs_sb->tlink_tree_lock);
4358
4359         if (tlink == NULL) {
4360                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4361                 if (newtlink == NULL)
4362                         return ERR_PTR(-ENOMEM);
4363                 newtlink->tl_uid = fsuid;
4364                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4365                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4366                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4367                 cifs_get_tlink(newtlink);
4368
4369                 spin_lock(&cifs_sb->tlink_tree_lock);
4370                 /* was one inserted after previous search? */
4371                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4372                 if (tlink) {
4373                         cifs_get_tlink(tlink);
4374                         spin_unlock(&cifs_sb->tlink_tree_lock);
4375                         kfree(newtlink);
4376                         goto wait_for_construction;
4377                 }
4378                 tlink = newtlink;
4379                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4380                 spin_unlock(&cifs_sb->tlink_tree_lock);
4381         } else {
4382 wait_for_construction:
4383                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4384                                   TASK_INTERRUPTIBLE);
4385                 if (ret) {
4386                         cifs_put_tlink(tlink);
4387                         return ERR_PTR(-ERESTARTSYS);
4388                 }
4389
4390                 /* if it's good, return it */
4391                 if (!IS_ERR(tlink->tl_tcon))
4392                         return tlink;
4393
4394                 /* return error if we tried this already recently */
4395                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4396                         cifs_put_tlink(tlink);
4397                         return ERR_PTR(-EACCES);
4398                 }
4399
4400                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4401                         goto wait_for_construction;
4402         }
4403
4404         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4405         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4406         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4407
4408         if (IS_ERR(tlink->tl_tcon)) {
4409                 cifs_put_tlink(tlink);
4410                 return ERR_PTR(-EACCES);
4411         }
4412
4413         return tlink;
4414 }
4415
4416 /*
4417  * periodic workqueue job that scans tcon_tree for a superblock and closes
4418  * out tcons.
4419  */
4420 static void
4421 cifs_prune_tlinks(struct work_struct *work)
4422 {
4423         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4424                                                     prune_tlinks.work);
4425         struct rb_root *root = &cifs_sb->tlink_tree;
4426         struct rb_node *node;
4427         struct rb_node *tmp;
4428         struct tcon_link *tlink;
4429
4430         /*
4431          * Because we drop the spinlock in the loop in order to put the tlink
4432          * it's not guarded against removal of links from the tree. The only
4433          * places that remove entries from the tree are this function and
4434          * umounts. Because this function is non-reentrant and is canceled
4435          * before umount can proceed, this is safe.
4436          */
4437         spin_lock(&cifs_sb->tlink_tree_lock);
4438         node = rb_first(root);
4439         while (node != NULL) {
4440                 tmp = node;
4441                 node = rb_next(tmp);
4442                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4443
4444                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4445                     atomic_read(&tlink->tl_count) != 0 ||
4446                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4447                         continue;
4448
4449                 cifs_get_tlink(tlink);
4450                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4451                 rb_erase(tmp, root);
4452
4453                 spin_unlock(&cifs_sb->tlink_tree_lock);
4454                 cifs_put_tlink(tlink);
4455                 spin_lock(&cifs_sb->tlink_tree_lock);
4456         }
4457         spin_unlock(&cifs_sb->tlink_tree_lock);
4458
4459         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4460                                 TLINK_IDLE_EXPIRE);
4461 }
4462
4463 #ifdef CONFIG_CIFS_DFS_UPCALL
4464 /* Update dfs referral path of superblock */
4465 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4466                                   const char *target)
4467 {
4468         int rc = 0;
4469         size_t len = strlen(target);
4470         char *refpath, *npath;
4471
4472         if (unlikely(len < 2 || *target != '\\'))
4473                 return -EINVAL;
4474
4475         if (target[1] == '\\') {
4476                 len += 1;
4477                 refpath = kmalloc(len, GFP_KERNEL);
4478                 if (!refpath)
4479                         return -ENOMEM;
4480
4481                 scnprintf(refpath, len, "%s", target);
4482         } else {
4483                 len += sizeof("\\");
4484                 refpath = kmalloc(len, GFP_KERNEL);
4485                 if (!refpath)
4486                         return -ENOMEM;
4487
4488                 scnprintf(refpath, len, "\\%s", target);
4489         }
4490
4491         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4492         kfree(refpath);
4493
4494         if (IS_ERR(npath)) {
4495                 rc = PTR_ERR(npath);
4496         } else {
4497                 mutex_lock(&server->refpath_lock);
4498                 kfree(server->leaf_fullpath);
4499                 server->leaf_fullpath = npath;
4500                 mutex_unlock(&server->refpath_lock);
4501                 server->current_fullpath = server->leaf_fullpath;
4502         }
4503         return rc;
4504 }
4505
4506 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4507                                        size_t tcp_host_len, char *share, bool *target_match)
4508 {
4509         int rc = 0;
4510         const char *dfs_host;
4511         size_t dfs_host_len;
4512
4513         *target_match = true;
4514         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4515
4516         /* Check if hostnames or addresses match */
4517         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4518                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4519                          dfs_host, (int)tcp_host_len, tcp_host);
4520                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4521                 if (rc)
4522                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4523         }
4524         return rc;
4525 }
4526
4527 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4528                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4529                                      struct dfs_cache_tgt_list *tl)
4530 {
4531         int rc;
4532         struct TCP_Server_Info *server = tcon->ses->server;
4533         const struct smb_version_operations *ops = server->ops;
4534         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4535         char *share = NULL, *prefix = NULL;
4536         const char *tcp_host;
4537         size_t tcp_host_len;
4538         struct dfs_cache_tgt_iterator *tit;
4539         bool target_match;
4540
4541         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4542
4543         tit = dfs_cache_get_tgt_iterator(tl);
4544         if (!tit) {
4545                 rc = -ENOENT;
4546                 goto out;
4547         }
4548
4549         /* Try to tree connect to all dfs targets */
4550         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4551                 const char *target = dfs_cache_get_tgt_name(tit);
4552                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4553
4554                 kfree(share);
4555                 kfree(prefix);
4556                 share = prefix = NULL;
4557
4558                 /* Check if share matches with tcp ses */
4559                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4560                 if (rc) {
4561                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4562                         break;
4563                 }
4564
4565                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4566                                                  &target_match);
4567                 if (rc)
4568                         break;
4569                 if (!target_match) {
4570                         rc = -EHOSTUNREACH;
4571                         continue;
4572                 }
4573
4574                 if (ipc->need_reconnect) {
4575                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4576                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4577                         if (rc)
4578                                 break;
4579                 }
4580
4581                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4582                 if (!islink) {
4583                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4584                         break;
4585                 }
4586                 /*
4587                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4588                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4589                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4590                  * newly resolved target.
4591                  */
4592                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4593                                    NULL, &ntl)) {
4594                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4595                         if (rc)
4596                                 continue;
4597                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4598                         if (!rc)
4599                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4600                 } else {
4601                         /* Target is another dfs share */
4602                         rc = update_server_fullpath(server, cifs_sb, target);
4603                         dfs_cache_free_tgts(tl);
4604
4605                         if (!rc) {
4606                                 rc = -EREMOTE;
4607                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4608                         } else
4609                                 dfs_cache_free_tgts(&ntl);
4610                 }
4611                 break;
4612         }
4613
4614 out:
4615         kfree(share);
4616         kfree(prefix);
4617
4618         return rc;
4619 }
4620
4621 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4622                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4623                                    struct dfs_cache_tgt_list *tl)
4624 {
4625         int rc;
4626         int num_links = 0;
4627         struct TCP_Server_Info *server = tcon->ses->server;
4628
4629         do {
4630                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4631                 if (!rc || rc != -EREMOTE)
4632                         break;
4633         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4634         /*
4635          * If we couldn't tree connect to any targets from last referral path, then retry from
4636          * original referral path.
4637          */
4638         if (rc && server->current_fullpath != server->origin_fullpath) {
4639                 server->current_fullpath = server->origin_fullpath;
4640                 cifs_signal_cifsd_for_reconnect(server, true);
4641         }
4642
4643         dfs_cache_free_tgts(tl);
4644         return rc;
4645 }
4646
4647 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4648 {
4649         int rc;
4650         struct TCP_Server_Info *server = tcon->ses->server;
4651         const struct smb_version_operations *ops = server->ops;
4652         struct super_block *sb = NULL;
4653         struct cifs_sb_info *cifs_sb;
4654         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4655         char *tree;
4656         struct dfs_info3_param ref = {0};
4657
4658         /* only send once per connect */
4659         spin_lock(&tcon->tc_lock);
4660         if (tcon->ses->ses_status != SES_GOOD ||
4661             (tcon->status != TID_NEW &&
4662             tcon->status != TID_NEED_TCON)) {
4663                 spin_unlock(&tcon->tc_lock);
4664                 return 0;
4665         }
4666         tcon->status = TID_IN_TCON;
4667         spin_unlock(&tcon->tc_lock);
4668
4669         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4670         if (!tree) {
4671                 rc = -ENOMEM;
4672                 goto out;
4673         }
4674
4675         if (tcon->ipc) {
4676                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4677                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4678                 goto out;
4679         }
4680
4681         sb = cifs_get_tcp_super(server);
4682         if (IS_ERR(sb)) {
4683                 rc = PTR_ERR(sb);
4684                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4685                 goto out;
4686         }
4687
4688         cifs_sb = CIFS_SB(sb);
4689
4690         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4691         if (!server->current_fullpath ||
4692             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4693                 rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls);
4694                 goto out;
4695         }
4696
4697         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4698                                      &tl);
4699         free_dfs_info_param(&ref);
4700
4701 out:
4702         kfree(tree);
4703         cifs_put_tcp_super(sb);
4704
4705         if (rc) {
4706                 spin_lock(&tcon->tc_lock);
4707                 if (tcon->status == TID_IN_TCON)
4708                         tcon->status = TID_NEED_TCON;
4709                 spin_unlock(&tcon->tc_lock);
4710         } else {
4711                 spin_lock(&tcon->tc_lock);
4712                 if (tcon->status == TID_IN_TCON)
4713                         tcon->status = TID_GOOD;
4714                 spin_unlock(&tcon->tc_lock);
4715                 tcon->need_reconnect = false;
4716         }
4717
4718         return rc;
4719 }
4720 #else
4721 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4722 {
4723         int rc;
4724         const struct smb_version_operations *ops = tcon->ses->server->ops;
4725
4726         /* only send once per connect */
4727         spin_lock(&tcon->tc_lock);
4728         if (tcon->ses->ses_status != SES_GOOD ||
4729             (tcon->status != TID_NEW &&
4730             tcon->status != TID_NEED_TCON)) {
4731                 spin_unlock(&tcon->tc_lock);
4732                 return 0;
4733         }
4734         tcon->status = TID_IN_TCON;
4735         spin_unlock(&tcon->tc_lock);
4736
4737         rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4738         if (rc) {
4739                 spin_lock(&tcon->tc_lock);
4740                 if (tcon->status == TID_IN_TCON)
4741                         tcon->status = TID_NEED_TCON;
4742                 spin_unlock(&tcon->tc_lock);
4743         } else {
4744                 spin_lock(&tcon->tc_lock);
4745                 if (tcon->status == TID_IN_TCON)
4746                         tcon->status = TID_GOOD;
4747                 tcon->need_reconnect = false;
4748                 spin_unlock(&tcon->tc_lock);
4749         }
4750
4751         return rc;
4752 }
4753 #endif