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.h"
  50 #include "dfs_cache.h"
  51 #endif
  52 #include "fs_context.h"
  53 #include "cifs_swn.h"
  54
  55 extern mempool_t *cifs_req_poolp;
  56 extern bool disable_legacy_dialects;
  57
  58 /* FIXME: should these be tunable? */
  59 #define TLINK_ERROR_EXPIRE      (1 * HZ)
  60 #define TLINK_IDLE_EXPIRE       (600 * HZ)
  61
  62 /* Drop the connection to not overload the server */
  63 #define NUM_STATUS_IO_TIMEOUT   5
  64
  65 static int ip_connect(struct TCP_Server_Info *server);
  66 static int generic_ip_connect(struct TCP_Server_Info *server);
  67 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  68 static void cifs_prune_tlinks(struct work_struct *work);
  69
  70 /*
  71  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  72  * get their ip addresses changed at some point.
  73  *
  74  * This should be called with server->srv_mutex held.
  75  */
  76 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  77 {
  78         int rc;
  79         int len;
  80         char *unc;
  81         struct sockaddr_storage ss;
  82
  83         if (!server->hostname)
  84                 return -EINVAL;
  85
  86         /* if server hostname isn't populated, there's nothing to do here */
  87         if (server->hostname[0] == '\0')
  88                 return 0;
  89
  90         len = strlen(server->hostname) + 3;
  91
  92         unc = kmalloc(len, GFP_KERNEL);
  93         if (!unc) {
  94                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
  95                 return -ENOMEM;
  96         }
  97         scnprintf(unc, len, "\\\\%s", server->hostname);
  98
  99         spin_lock(&server->srv_lock);
 100         ss = server->dstaddr;
 101         spin_unlock(&server->srv_lock);
 102
 103         rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);
 104         kfree(unc);
 105
 106         if (rc < 0) {
 107                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 108                          __func__, server->hostname, rc);
 109         } else {
 110                 spin_lock(&server->srv_lock);
 111                 memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 112                 spin_unlock(&server->srv_lock);
 113                 rc = 0;
 114         }
 115
 116         return rc;
 117 }
 118
 119 static void smb2_query_server_interfaces(struct work_struct *work)
 120 {
 121         int rc;
 122         struct cifs_tcon *tcon = container_of(work,
 123                                         struct cifs_tcon,
 124                                         query_interfaces.work);
 125
 126         /*
 127          * query server network interfaces, in case they change
 128          */
 129         rc = SMB3_request_interfaces(0, tcon, false);
 130         if (rc) {
 131                 cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 132                                 __func__, rc);
 133         }
 134
 135         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 136                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
 137 }
 138
 139 /*
 140  * Update the tcpStatus for the server.
 141  * This is used to signal the cifsd thread to call cifs_reconnect
 142  * ONLY cifsd thread should call cifs_reconnect. For any other
 143  * thread, use this function
 144  *
 145  * @server: the tcp ses for which reconnect is needed
 146  * @all_channels: if this needs to be done for all channels
 147  */
 148 void
 149 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 150                                 bool all_channels)
 151 {
 152         struct TCP_Server_Info *pserver;
 153         struct cifs_ses *ses;
 154         int i;
 155
 156         /* If server is a channel, select the primary channel */
 157         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 158
 159         spin_lock(&pserver->srv_lock);
 160         if (!all_channels) {
 161                 pserver->tcpStatus = CifsNeedReconnect;
 162                 spin_unlock(&pserver->srv_lock);
 163                 return;
 164         }
 165         spin_unlock(&pserver->srv_lock);
 166
 167         spin_lock(&cifs_tcp_ses_lock);
 168         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 169                 spin_lock(&ses->chan_lock);
 170                 for (i = 0; i < ses->chan_count; i++) {
 171                         spin_lock(&ses->chans[i].server->srv_lock);
 172                         ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 173                         spin_unlock(&ses->chans[i].server->srv_lock);
 174                 }
 175                 spin_unlock(&ses->chan_lock);
 176         }
 177         spin_unlock(&cifs_tcp_ses_lock);
 178 }
 179
 180 /*
 181  * Mark all sessions and tcons for reconnect.
 182  * IMPORTANT: make sure that this gets called only from
 183  * cifsd thread. For any other thread, use
 184  * cifs_signal_cifsd_for_reconnect
 185  *
 186  * @server: the tcp ses for which reconnect is needed
 187  * @server needs to be previously set to CifsNeedReconnect.
 188  * @mark_smb_session: whether even sessions need to be marked
 189  */
 190 void
 191 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 192                                       bool mark_smb_session)
 193 {
 194         struct TCP_Server_Info *pserver;
 195         struct cifs_ses *ses, *nses;
 196         struct cifs_tcon *tcon;
 197
 198         /*
 199          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 200          * are not used until reconnected.
 201          */
 202         cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 203
 204         /* If server is a channel, select the primary channel */
 205         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 206
 207
 208         spin_lock(&cifs_tcp_ses_lock);
 209         list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 210                 /* check if iface is still active */
 211                 if (!cifs_chan_is_iface_active(ses, server))
 212                         cifs_chan_update_iface(ses, server);
 213
 214                 spin_lock(&ses->chan_lock);
 215                 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
 216                         spin_unlock(&ses->chan_lock);
 217                         continue;
 218                 }
 219
 220                 if (mark_smb_session)
 221                         CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 222                 else
 223                         cifs_chan_set_need_reconnect(ses, server);
 224
 225                 cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
 226                          __func__, ses->chans_need_reconnect);
 227
 228                 /* If all channels need reconnect, then tcon needs reconnect */
 229                 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
 230                         spin_unlock(&ses->chan_lock);
 231                         continue;
 232                 }
 233                 spin_unlock(&ses->chan_lock);
 234
 235                 spin_lock(&ses->ses_lock);
 236                 ses->ses_status = SES_NEED_RECON;
 237                 spin_unlock(&ses->ses_lock);
 238
 239                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 240                         tcon->need_reconnect = true;
 241                         spin_lock(&tcon->tc_lock);
 242                         tcon->status = TID_NEED_RECON;
 243                         spin_unlock(&tcon->tc_lock);
 244                 }
 245                 if (ses->tcon_ipc) {
 246                         ses->tcon_ipc->need_reconnect = true;
 247                         spin_lock(&ses->tcon_ipc->tc_lock);
 248                         ses->tcon_ipc->status = TID_NEED_RECON;
 249                         spin_unlock(&ses->tcon_ipc->tc_lock);
 250                 }
 251         }
 252         spin_unlock(&cifs_tcp_ses_lock);
 253 }
 254
 255 static void
 256 cifs_abort_connection(struct TCP_Server_Info *server)
 257 {
 258         struct mid_q_entry *mid, *nmid;
 259         struct list_head retry_list;
 260
 261         server->maxBuf = 0;
 262         server->max_read = 0;
 263
 264         /* do not want to be sending data on a socket we are freeing */
 265         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 266         cifs_server_lock(server);
 267         if (server->ssocket) {
 268                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 269                          server->ssocket->flags);
 270                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 271                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 272                          server->ssocket->flags);
 273                 sock_release(server->ssocket);
 274                 server->ssocket = NULL;
 275         }
 276         server->sequence_number = 0;
 277         server->session_estab = false;
 278         kfree_sensitive(server->session_key.response);
 279         server->session_key.response = NULL;
 280         server->session_key.len = 0;
 281         server->lstrp = jiffies;
 282
 283         /* mark submitted MIDs for retry and issue callback */
 284         INIT_LIST_HEAD(&retry_list);
 285         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 286         spin_lock(&server->mid_lock);
 287         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 288                 kref_get(&mid->refcount);
 289                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 290                         mid->mid_state = MID_RETRY_NEEDED;
 291                 list_move(&mid->qhead, &retry_list);
 292                 mid->mid_flags |= MID_DELETED;
 293         }
 294         spin_unlock(&server->mid_lock);
 295         cifs_server_unlock(server);
 296
 297         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 298         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 299                 list_del_init(&mid->qhead);
 300                 mid->callback(mid);
 301                 release_mid(mid);
 302         }
 303
 304         if (cifs_rdma_enabled(server)) {
 305                 cifs_server_lock(server);
 306                 smbd_destroy(server);
 307                 cifs_server_unlock(server);
 308         }
 309 }
 310
 311 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 312 {
 313         spin_lock(&server->srv_lock);
 314         server->nr_targets = num_targets;
 315         if (server->tcpStatus == CifsExiting) {
 316                 /* the demux thread will exit normally next time through the loop */
 317                 spin_unlock(&server->srv_lock);
 318                 wake_up(&server->response_q);
 319                 return false;
 320         }
 321
 322         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 323         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 324                              server->hostname);
 325         server->tcpStatus = CifsNeedReconnect;
 326
 327         spin_unlock(&server->srv_lock);
 328         return true;
 329 }
 330
 331 /*
 332  * cifs tcp session reconnection
 333  *
 334  * mark tcp session as reconnecting so temporarily locked
 335  * mark all smb sessions as reconnecting for tcp session
 336  * reconnect tcp session
 337  * wake up waiters on reconnection? - (not needed currently)
 338  *
 339  * if mark_smb_session is passed as true, unconditionally mark
 340  * the smb session (and tcon) for reconnect as well. This value
 341  * doesn't really matter for non-multichannel scenario.
 342  *
 343  */
 344 static int __cifs_reconnect(struct TCP_Server_Info *server,
 345                             bool mark_smb_session)
 346 {
 347         int rc = 0;
 348
 349         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 350                 return 0;
 351
 352         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 353
 354         cifs_abort_connection(server);
 355
 356         do {
 357                 try_to_freeze();
 358                 cifs_server_lock(server);
 359
 360                 if (!cifs_swn_set_server_dstaddr(server)) {
 361                         /* resolve the hostname again to make sure that IP address is up-to-date */
 362                         rc = reconn_set_ipaddr_from_hostname(server);
 363                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 364                 }
 365
 366                 if (cifs_rdma_enabled(server))
 367                         rc = smbd_reconnect(server);
 368                 else
 369                         rc = generic_ip_connect(server);
 370                 if (rc) {
 371                         cifs_server_unlock(server);
 372                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 373                         msleep(3000);
 374                 } else {
 375                         atomic_inc(&tcpSesReconnectCount);
 376                         set_credits(server, 1);
 377                         spin_lock(&server->srv_lock);
 378                         if (server->tcpStatus != CifsExiting)
 379                                 server->tcpStatus = CifsNeedNegotiate;
 380                         spin_unlock(&server->srv_lock);
 381                         cifs_swn_reset_server_dstaddr(server);
 382                         cifs_server_unlock(server);
 383                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 384                 }
 385         } while (server->tcpStatus == CifsNeedReconnect);
 386
 387         spin_lock(&server->srv_lock);
 388         if (server->tcpStatus == CifsNeedNegotiate)
 389                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 390         spin_unlock(&server->srv_lock);
 391
 392         wake_up(&server->response_q);
 393         return rc;
 394 }
 395
 396 #ifdef CONFIG_CIFS_DFS_UPCALL
 397 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 398 {
 399         int rc;
 400         char *hostname;
 401
 402         if (!cifs_swn_set_server_dstaddr(server)) {
 403                 if (server->hostname != target) {
 404                         hostname = extract_hostname(target);
 405                         if (!IS_ERR(hostname)) {
 406                                 spin_lock(&server->srv_lock);
 407                                 kfree(server->hostname);
 408                                 server->hostname = hostname;
 409                                 spin_unlock(&server->srv_lock);
 410                         } else {
 411                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 412                                          __func__, PTR_ERR(hostname));
 413                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 414                                          server->hostname);
 415                         }
 416                 }
 417                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 418                 rc = reconn_set_ipaddr_from_hostname(server);
 419                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 420         }
 421         /* Reconnect the socket */
 422         if (cifs_rdma_enabled(server))
 423                 rc = smbd_reconnect(server);
 424         else
 425                 rc = generic_ip_connect(server);
 426
 427         return rc;
 428 }
 429
 430 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 431                                      struct dfs_cache_tgt_iterator **target_hint)
 432 {
 433         int rc;
 434         struct dfs_cache_tgt_iterator *tit;
 435
 436         *target_hint = NULL;
 437
 438         /* If dfs target list is empty, then reconnect to last server */
 439         tit = dfs_cache_get_tgt_iterator(tl);
 440         if (!tit)
 441                 return __reconnect_target_unlocked(server, server->hostname);
 442
 443         /* Otherwise, try every dfs target in @tl */
 444         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 445                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 446                 if (!rc) {
 447                         *target_hint = tit;
 448                         break;
 449                 }
 450         }
 451         return rc;
 452 }
 453
 454 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 455 {
 456         int rc = 0;
 457         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 458         struct dfs_cache_tgt_iterator *target_hint = NULL;
 459         int num_targets = 0;
 460
 461         /*
 462          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 463          *
 464          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 465          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 466          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 467          * refreshing the referral, so, in this case, default it to 1.
 468          */
 469         mutex_lock(&server->refpath_lock);
 470         if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
 471                 num_targets = dfs_cache_get_nr_tgts(&tl);
 472         mutex_unlock(&server->refpath_lock);
 473         if (!num_targets)
 474                 num_targets = 1;
 475
 476         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 477                 return 0;
 478
 479         /*
 480          * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 481          * different server or share during failover.  It could be improved by adding some logic to
 482          * only do that in case it connects to a different server or share, though.
 483          */
 484         cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 485
 486         cifs_abort_connection(server);
 487
 488         do {
 489                 try_to_freeze();
 490                 cifs_server_lock(server);
 491
 492                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 493                 if (rc) {
 494                         /* Failed to reconnect socket */
 495                         cifs_server_unlock(server);
 496                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 497                         msleep(3000);
 498                         continue;
 499                 }
 500                 /*
 501                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 502                  * process waiting for reconnect will know it needs to re-establish session and tcon
 503                  * through the reconnected target server.
 504                  */
 505                 atomic_inc(&tcpSesReconnectCount);
 506                 set_credits(server, 1);
 507                 spin_lock(&server->srv_lock);
 508                 if (server->tcpStatus != CifsExiting)
 509                         server->tcpStatus = CifsNeedNegotiate;
 510                 spin_unlock(&server->srv_lock);
 511                 cifs_swn_reset_server_dstaddr(server);
 512                 cifs_server_unlock(server);
 513                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 514         } while (server->tcpStatus == CifsNeedReconnect);
 515
 516         mutex_lock(&server->refpath_lock);
 517         dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
 518         mutex_unlock(&server->refpath_lock);
 519         dfs_cache_free_tgts(&tl);
 520
 521         /* Need to set up echo worker again once connection has been established */
 522         spin_lock(&server->srv_lock);
 523         if (server->tcpStatus == CifsNeedNegotiate)
 524                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 525         spin_unlock(&server->srv_lock);
 526
 527         wake_up(&server->response_q);
 528         return rc;
 529 }
 530
 531 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 532 {
 533         mutex_lock(&server->refpath_lock);
 534         if (!server->leaf_fullpath) {
 535                 mutex_unlock(&server->refpath_lock);
 536                 return __cifs_reconnect(server, mark_smb_session);
 537         }
 538         mutex_unlock(&server->refpath_lock);
 539
 540         return reconnect_dfs_server(server);
 541 }
 542 #else
 543 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 544 {
 545         return __cifs_reconnect(server, mark_smb_session);
 546 }
 547 #endif
 548
 549 static void
 550 cifs_echo_request(struct work_struct *work)
 551 {
 552         int rc;
 553         struct TCP_Server_Info *server = container_of(work,
 554                                         struct TCP_Server_Info, echo.work);
 555
 556         /*
 557          * We cannot send an echo if it is disabled.
 558          * Also, no need to ping if we got a response recently.
 559          */
 560
 561         if (server->tcpStatus == CifsNeedReconnect ||
 562             server->tcpStatus == CifsExiting ||
 563             server->tcpStatus == CifsNew ||
 564             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 565             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 566                 goto requeue_echo;
 567
 568         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 569         cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc);
 570
 571         /* Check witness registrations */
 572         cifs_swn_check();
 573
 574 requeue_echo:
 575         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 576 }
 577
 578 static bool
 579 allocate_buffers(struct TCP_Server_Info *server)
 580 {
 581         if (!server->bigbuf) {
 582                 server->bigbuf = (char *)cifs_buf_get();
 583                 if (!server->bigbuf) {
 584                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 585                         msleep(3000);
 586                         /* retry will check if exiting */
 587                         return false;
 588                 }
 589         } else if (server->large_buf) {
 590                 /* we are reusing a dirty large buf, clear its start */
 591                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 592         }
 593
 594         if (!server->smallbuf) {
 595                 server->smallbuf = (char *)cifs_small_buf_get();
 596                 if (!server->smallbuf) {
 597                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 598                         msleep(1000);
 599                         /* retry will check if exiting */
 600                         return false;
 601                 }
 602                 /* beginning of smb buffer is cleared in our buf_get */
 603         } else {
 604                 /* if existing small buf clear beginning */
 605                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 606         }
 607
 608         return true;
 609 }
 610
 611 static bool
 612 server_unresponsive(struct TCP_Server_Info *server)
 613 {
 614         /*
 615          * We need to wait 3 echo intervals to make sure we handle such
 616          * situations right:
 617          * 1s  client sends a normal SMB request
 618          * 2s  client gets a response
 619          * 30s echo workqueue job pops, and decides we got a response recently
 620          *     and don't need to send another
 621          * ...
 622          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 623          *     a response in >60s.
 624          */
 625         spin_lock(&server->srv_lock);
 626         if ((server->tcpStatus == CifsGood ||
 627             server->tcpStatus == CifsNeedNegotiate) &&
 628             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 629             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 630                 spin_unlock(&server->srv_lock);
 631                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 632                          (3 * server->echo_interval) / HZ);
 633                 cifs_reconnect(server, false);
 634                 return true;
 635         }
 636         spin_unlock(&server->srv_lock);
 637
 638         return false;
 639 }
 640
 641 static inline bool
 642 zero_credits(struct TCP_Server_Info *server)
 643 {
 644         int val;
 645
 646         spin_lock(&server->req_lock);
 647         val = server->credits + server->echo_credits + server->oplock_credits;
 648         if (server->in_flight == 0 && val == 0) {
 649                 spin_unlock(&server->req_lock);
 650                 return true;
 651         }
 652         spin_unlock(&server->req_lock);
 653         return false;
 654 }
 655
 656 static int
 657 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 658 {
 659         int length = 0;
 660         int total_read;
 661
 662         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 663                 try_to_freeze();
 664
 665                 /* reconnect if no credits and no requests in flight */
 666                 if (zero_credits(server)) {
 667                         cifs_reconnect(server, false);
 668                         return -ECONNABORTED;
 669                 }
 670
 671                 if (server_unresponsive(server))
 672                         return -ECONNABORTED;
 673                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 674                         length = smbd_recv(server->smbd_conn, smb_msg);
 675                 else
 676                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 677
 678                 spin_lock(&server->srv_lock);
 679                 if (server->tcpStatus == CifsExiting) {
 680                         spin_unlock(&server->srv_lock);
 681                         return -ESHUTDOWN;
 682                 }
 683
 684                 if (server->tcpStatus == CifsNeedReconnect) {
 685                         spin_unlock(&server->srv_lock);
 686                         cifs_reconnect(server, false);
 687                         return -ECONNABORTED;
 688                 }
 689                 spin_unlock(&server->srv_lock);
 690
 691                 if (length == -ERESTARTSYS ||
 692                     length == -EAGAIN ||
 693                     length == -EINTR) {
 694                         /*
 695                          * Minimum sleep to prevent looping, allowing socket
 696                          * to clear and app threads to set tcpStatus
 697                          * CifsNeedReconnect if server hung.
 698                          */
 699                         usleep_range(1000, 2000);
 700                         length = 0;
 701                         continue;
 702                 }
 703
 704                 if (length <= 0) {
 705                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 706                         cifs_reconnect(server, false);
 707                         return -ECONNABORTED;
 708                 }
 709         }
 710         return total_read;
 711 }
 712
 713 int
 714 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 715                       unsigned int to_read)
 716 {
 717         struct msghdr smb_msg = {};
 718         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 719         iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
 720
 721         return cifs_readv_from_socket(server, &smb_msg);
 722 }
 723
 724 ssize_t
 725 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 726 {
 727         struct msghdr smb_msg = {};
 728
 729         /*
 730          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 731          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 732          *  so little to initialize in struct msghdr
 733          */
 734         iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
 735
 736         return cifs_readv_from_socket(server, &smb_msg);
 737 }
 738
 739 int
 740 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 741         unsigned int page_offset, unsigned int to_read)
 742 {
 743         struct msghdr smb_msg = {};
 744         struct bio_vec bv;
 745
 746         bvec_set_page(&bv, page, to_read, page_offset);
 747         iov_iter_bvec(&smb_msg.msg_iter, ITER_DEST, &bv, 1, to_read);
 748         return cifs_readv_from_socket(server, &smb_msg);
 749 }
 750
 751 int
 752 cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
 753                            unsigned int to_read)
 754 {
 755         struct msghdr smb_msg = { .msg_iter = *iter };
 756         int ret;
 757
 758         iov_iter_truncate(&smb_msg.msg_iter, to_read);
 759         ret = cifs_readv_from_socket(server, &smb_msg);
 760         if (ret > 0)
 761                 iov_iter_advance(iter, ret);
 762         return ret;
 763 }
 764
 765 static bool
 766 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 767 {
 768         /*
 769          * The first byte big endian of the length field,
 770          * is actually not part of the length but the type
 771          * with the most common, zero, as regular data.
 772          */
 773         switch (type) {
 774         case RFC1002_SESSION_MESSAGE:
 775                 /* Regular SMB response */
 776                 return true;
 777         case RFC1002_SESSION_KEEP_ALIVE:
 778                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 779                 break;
 780         case RFC1002_POSITIVE_SESSION_RESPONSE:
 781                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 782                 break;
 783         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 784                 /*
 785                  * We get this from Windows 98 instead of an error on
 786                  * SMB negprot response.
 787                  */
 788                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 789                 /* give server a second to clean up */
 790                 msleep(1000);
 791                 /*
 792                  * Always try 445 first on reconnect since we get NACK
 793                  * on some if we ever connected to port 139 (the NACK
 794                  * is since we do not begin with RFC1001 session
 795                  * initialize frame).
 796                  */
 797                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 798                 cifs_reconnect(server, true);
 799                 break;
 800         default:
 801                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 802                 cifs_reconnect(server, true);
 803         }
 804
 805         return false;
 806 }
 807
 808 void
 809 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 810 {
 811 #ifdef CONFIG_CIFS_STATS2
 812         mid->when_received = jiffies;
 813 #endif
 814         spin_lock(&mid->server->mid_lock);
 815         if (!malformed)
 816                 mid->mid_state = MID_RESPONSE_RECEIVED;
 817         else
 818                 mid->mid_state = MID_RESPONSE_MALFORMED;
 819         /*
 820          * Trying to handle/dequeue a mid after the send_recv()
 821          * function has finished processing it is a bug.
 822          */
 823         if (mid->mid_flags & MID_DELETED) {
 824                 spin_unlock(&mid->server->mid_lock);
 825                 pr_warn_once("trying to dequeue a deleted mid\n");
 826         } else {
 827                 list_del_init(&mid->qhead);
 828                 mid->mid_flags |= MID_DELETED;
 829                 spin_unlock(&mid->server->mid_lock);
 830         }
 831 }
 832
 833 static unsigned int
 834 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 835 {
 836         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 837
 838         /*
 839          * SMB1 does not use credits.
 840          */
 841         if (is_smb1(server))
 842                 return 0;
 843
 844         return le16_to_cpu(shdr->CreditRequest);
 845 }
 846
 847 static void
 848 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 849            char *buf, int malformed)
 850 {
 851         if (server->ops->check_trans2 &&
 852             server->ops->check_trans2(mid, server, buf, malformed))
 853                 return;
 854         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 855         mid->resp_buf = buf;
 856         mid->large_buf = server->large_buf;
 857         /* Was previous buf put in mpx struct for multi-rsp? */
 858         if (!mid->multiRsp) {
 859                 /* smb buffer will be freed by user thread */
 860                 if (server->large_buf)
 861                         server->bigbuf = NULL;
 862                 else
 863                         server->smallbuf = NULL;
 864         }
 865         dequeue_mid(mid, malformed);
 866 }
 867
 868 int
 869 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 870 {
 871         bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 872         bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 873         bool mnt_sign_enabled;
 874
 875         /*
 876          * Is signing required by mnt options? If not then check
 877          * global_secflags to see if it is there.
 878          */
 879         if (!mnt_sign_required)
 880                 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 881                                                 CIFSSEC_MUST_SIGN);
 882
 883         /*
 884          * If signing is required then it's automatically enabled too,
 885          * otherwise, check to see if the secflags allow it.
 886          */
 887         mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 888                                 (global_secflags & CIFSSEC_MAY_SIGN);
 889
 890         /* If server requires signing, does client allow it? */
 891         if (srv_sign_required) {
 892                 if (!mnt_sign_enabled) {
 893                         cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 894                         return -EOPNOTSUPP;
 895                 }
 896                 server->sign = true;
 897         }
 898
 899         /* If client requires signing, does server allow it? */
 900         if (mnt_sign_required) {
 901                 if (!srv_sign_enabled) {
 902                         cifs_dbg(VFS, "Server does not support signing!\n");
 903                         return -EOPNOTSUPP;
 904                 }
 905                 server->sign = true;
 906         }
 907
 908         if (cifs_rdma_enabled(server) && server->sign)
 909                 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 910
 911         return 0;
 912 }
 913
 914
 915 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 916 {
 917         int length;
 918
 919         /* take it off the list, if it's not already */
 920         spin_lock(&server->srv_lock);
 921         list_del_init(&server->tcp_ses_list);
 922         spin_unlock(&server->srv_lock);
 923
 924         cancel_delayed_work_sync(&server->echo);
 925
 926         spin_lock(&server->srv_lock);
 927         server->tcpStatus = CifsExiting;
 928         spin_unlock(&server->srv_lock);
 929         wake_up_all(&server->response_q);
 930
 931         /* check if we have blocked requests that need to free */
 932         spin_lock(&server->req_lock);
 933         if (server->credits <= 0)
 934                 server->credits = 1;
 935         spin_unlock(&server->req_lock);
 936         /*
 937          * Although there should not be any requests blocked on this queue it
 938          * can not hurt to be paranoid and try to wake up requests that may
 939          * haven been blocked when more than 50 at time were on the wire to the
 940          * same server - they now will see the session is in exit state and get
 941          * out of SendReceive.
 942          */
 943         wake_up_all(&server->request_q);
 944         /* give those requests time to exit */
 945         msleep(125);
 946         if (cifs_rdma_enabled(server))
 947                 smbd_destroy(server);
 948         if (server->ssocket) {
 949                 sock_release(server->ssocket);
 950                 server->ssocket = NULL;
 951         }
 952
 953         if (!list_empty(&server->pending_mid_q)) {
 954                 struct list_head dispose_list;
 955                 struct mid_q_entry *mid_entry;
 956                 struct list_head *tmp, *tmp2;
 957
 958                 INIT_LIST_HEAD(&dispose_list);
 959                 spin_lock(&server->mid_lock);
 960                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 961                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 962                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 963                         kref_get(&mid_entry->refcount);
 964                         mid_entry->mid_state = MID_SHUTDOWN;
 965                         list_move(&mid_entry->qhead, &dispose_list);
 966                         mid_entry->mid_flags |= MID_DELETED;
 967                 }
 968                 spin_unlock(&server->mid_lock);
 969
 970                 /* now walk dispose list and issue callbacks */
 971                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 972                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 973                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 974                         list_del_init(&mid_entry->qhead);
 975                         mid_entry->callback(mid_entry);
 976                         release_mid(mid_entry);
 977                 }
 978                 /* 1/8th of sec is more than enough time for them to exit */
 979                 msleep(125);
 980         }
 981
 982         if (!list_empty(&server->pending_mid_q)) {
 983                 /*
 984                  * mpx threads have not exited yet give them at least the smb
 985                  * send timeout time for long ops.
 986                  *
 987                  * Due to delays on oplock break requests, we need to wait at
 988                  * least 45 seconds before giving up on a request getting a
 989                  * response and going ahead and killing cifsd.
 990                  */
 991                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 992                 msleep(46000);
 993                 /*
 994                  * If threads still have not exited they are probably never
 995                  * coming home not much else we can do but free the memory.
 996                  */
 997         }
 998
 999         kfree(server->origin_fullpath);
1000         kfree(server->leaf_fullpath);
1001         kfree(server);
1002
1003         length = atomic_dec_return(&tcpSesAllocCount);
1004         if (length > 0)
1005                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1006 }
1007
1008 static int
1009 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1010 {
1011         int length;
1012         char *buf = server->smallbuf;
1013         unsigned int pdu_length = server->pdu_size;
1014
1015         /* make sure this will fit in a large buffer */
1016         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1017             HEADER_PREAMBLE_SIZE(server)) {
1018                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1019                 cifs_reconnect(server, true);
1020                 return -ECONNABORTED;
1021         }
1022
1023         /* switch to large buffer if too big for a small one */
1024         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1025                 server->large_buf = true;
1026                 memcpy(server->bigbuf, buf, server->total_read);
1027                 buf = server->bigbuf;
1028         }
1029
1030         /* now read the rest */
1031         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1032                                        pdu_length - MID_HEADER_SIZE(server));
1033
1034         if (length < 0)
1035                 return length;
1036         server->total_read += length;
1037
1038         dump_smb(buf, server->total_read);
1039
1040         return cifs_handle_standard(server, mid);
1041 }
1042
1043 int
1044 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1045 {
1046         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1047         int rc;
1048
1049         /*
1050          * We know that we received enough to get to the MID as we
1051          * checked the pdu_length earlier. Now check to see
1052          * if the rest of the header is OK.
1053          *
1054          * 48 bytes is enough to display the header and a little bit
1055          * into the payload for debugging purposes.
1056          */
1057         rc = server->ops->check_message(buf, server->total_read, server);
1058         if (rc)
1059                 cifs_dump_mem("Bad SMB: ", buf,
1060                         min_t(unsigned int, server->total_read, 48));
1061
1062         if (server->ops->is_session_expired &&
1063             server->ops->is_session_expired(buf)) {
1064                 cifs_reconnect(server, true);
1065                 return -1;
1066         }
1067
1068         if (server->ops->is_status_pending &&
1069             server->ops->is_status_pending(buf, server))
1070                 return -1;
1071
1072         if (!mid)
1073                 return rc;
1074
1075         handle_mid(mid, server, buf, rc);
1076         return 0;
1077 }
1078
1079 static void
1080 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1081 {
1082         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1083         int scredits, in_flight;
1084
1085         /*
1086          * SMB1 does not use credits.
1087          */
1088         if (is_smb1(server))
1089                 return;
1090
1091         if (shdr->CreditRequest) {
1092                 spin_lock(&server->req_lock);
1093                 server->credits += le16_to_cpu(shdr->CreditRequest);
1094                 scredits = server->credits;
1095                 in_flight = server->in_flight;
1096                 spin_unlock(&server->req_lock);
1097                 wake_up(&server->request_q);
1098
1099                 trace_smb3_hdr_credits(server->CurrentMid,
1100                                 server->conn_id, server->hostname, scredits,
1101                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1102                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1103                                 __func__, le16_to_cpu(shdr->CreditRequest),
1104                                 scredits);
1105         }
1106 }
1107
1108
1109 static int
1110 cifs_demultiplex_thread(void *p)
1111 {
1112         int i, num_mids, length;
1113         struct TCP_Server_Info *server = p;
1114         unsigned int pdu_length;
1115         unsigned int next_offset;
1116         char *buf = NULL;
1117         struct task_struct *task_to_wake = NULL;
1118         struct mid_q_entry *mids[MAX_COMPOUND];
1119         char *bufs[MAX_COMPOUND];
1120         unsigned int noreclaim_flag, num_io_timeout = 0;
1121
1122         noreclaim_flag = memalloc_noreclaim_save();
1123         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1124
1125         length = atomic_inc_return(&tcpSesAllocCount);
1126         if (length > 1)
1127                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1128
1129         set_freezable();
1130         allow_kernel_signal(SIGKILL);
1131         while (server->tcpStatus != CifsExiting) {
1132                 if (try_to_freeze())
1133                         continue;
1134
1135                 if (!allocate_buffers(server))
1136                         continue;
1137
1138                 server->large_buf = false;
1139                 buf = server->smallbuf;
1140                 pdu_length = 4; /* enough to get RFC1001 header */
1141
1142                 length = cifs_read_from_socket(server, buf, pdu_length);
1143                 if (length < 0)
1144                         continue;
1145
1146                 if (is_smb1(server))
1147                         server->total_read = length;
1148                 else
1149                         server->total_read = 0;
1150
1151                 /*
1152                  * The right amount was read from socket - 4 bytes,
1153                  * so we can now interpret the length field.
1154                  */
1155                 pdu_length = get_rfc1002_length(buf);
1156
1157                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1158                 if (!is_smb_response(server, buf[0]))
1159                         continue;
1160 next_pdu:
1161                 server->pdu_size = pdu_length;
1162
1163                 /* make sure we have enough to get to the MID */
1164                 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1165                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1166                                  server->pdu_size);
1167                         cifs_reconnect(server, true);
1168                         continue;
1169                 }
1170
1171                 /* read down to the MID */
1172                 length = cifs_read_from_socket(server,
1173                              buf + HEADER_PREAMBLE_SIZE(server),
1174                              MID_HEADER_SIZE(server));
1175                 if (length < 0)
1176                         continue;
1177                 server->total_read += length;
1178
1179                 if (server->ops->next_header) {
1180                         next_offset = server->ops->next_header(buf);
1181                         if (next_offset)
1182                                 server->pdu_size = next_offset;
1183                 }
1184
1185                 memset(mids, 0, sizeof(mids));
1186                 memset(bufs, 0, sizeof(bufs));
1187                 num_mids = 0;
1188
1189                 if (server->ops->is_transform_hdr &&
1190                     server->ops->receive_transform &&
1191                     server->ops->is_transform_hdr(buf)) {
1192                         length = server->ops->receive_transform(server,
1193                                                                 mids,
1194                                                                 bufs,
1195                                                                 &num_mids);
1196                 } else {
1197                         mids[0] = server->ops->find_mid(server, buf);
1198                         bufs[0] = buf;
1199                         num_mids = 1;
1200
1201                         if (!mids[0] || !mids[0]->receive)
1202                                 length = standard_receive3(server, mids[0]);
1203                         else
1204                                 length = mids[0]->receive(server, mids[0]);
1205                 }
1206
1207                 if (length < 0) {
1208                         for (i = 0; i < num_mids; i++)
1209                                 if (mids[i])
1210                                         release_mid(mids[i]);
1211                         continue;
1212                 }
1213
1214                 if (server->ops->is_status_io_timeout &&
1215                     server->ops->is_status_io_timeout(buf)) {
1216                         num_io_timeout++;
1217                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1218                                 cifs_reconnect(server, false);
1219                                 num_io_timeout = 0;
1220                                 continue;
1221                         }
1222                 }
1223
1224                 server->lstrp = jiffies;
1225
1226                 for (i = 0; i < num_mids; i++) {
1227                         if (mids[i] != NULL) {
1228                                 mids[i]->resp_buf_size = server->pdu_size;
1229
1230                                 if (bufs[i] && server->ops->is_network_name_deleted)
1231                                         server->ops->is_network_name_deleted(bufs[i],
1232                                                                         server);
1233
1234                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1235                                         mids[i]->callback(mids[i]);
1236
1237                                 release_mid(mids[i]);
1238                         } else if (server->ops->is_oplock_break &&
1239                                    server->ops->is_oplock_break(bufs[i],
1240                                                                 server)) {
1241                                 smb2_add_credits_from_hdr(bufs[i], server);
1242                                 cifs_dbg(FYI, "Received oplock break\n");
1243                         } else {
1244                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1245                                                 atomic_read(&mid_count));
1246                                 cifs_dump_mem("Received Data is: ", bufs[i],
1247                                               HEADER_SIZE(server));
1248                                 smb2_add_credits_from_hdr(bufs[i], server);
1249 #ifdef CONFIG_CIFS_DEBUG2
1250                                 if (server->ops->dump_detail)
1251                                         server->ops->dump_detail(bufs[i],
1252                                                                  server);
1253                                 cifs_dump_mids(server);
1254 #endif /* CIFS_DEBUG2 */
1255                         }
1256                 }
1257
1258                 if (pdu_length > server->pdu_size) {
1259                         if (!allocate_buffers(server))
1260                                 continue;
1261                         pdu_length -= server->pdu_size;
1262                         server->total_read = 0;
1263                         server->large_buf = false;
1264                         buf = server->smallbuf;
1265                         goto next_pdu;
1266                 }
1267         } /* end while !EXITING */
1268
1269         /* buffer usually freed in free_mid - need to free it here on exit */
1270         cifs_buf_release(server->bigbuf);
1271         if (server->smallbuf) /* no sense logging a debug message if NULL */
1272                 cifs_small_buf_release(server->smallbuf);
1273
1274         task_to_wake = xchg(&server->tsk, NULL);
1275         clean_demultiplex_info(server);
1276
1277         /* if server->tsk was NULL then wait for a signal before exiting */
1278         if (!task_to_wake) {
1279                 set_current_state(TASK_INTERRUPTIBLE);
1280                 while (!signal_pending(current)) {
1281                         schedule();
1282                         set_current_state(TASK_INTERRUPTIBLE);
1283                 }
1284                 set_current_state(TASK_RUNNING);
1285         }
1286
1287         memalloc_noreclaim_restore(noreclaim_flag);
1288         module_put_and_kthread_exit(0);
1289 }
1290
1291 /*
1292  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1293  * if srcaddr is specified and matches the IP address of the rhs argument
1294  */
1295 bool
1296 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1297 {
1298         switch (srcaddr->sa_family) {
1299         case AF_UNSPEC:
1300                 return (rhs->sa_family == AF_UNSPEC);
1301         case AF_INET: {
1302                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1303                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1304                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1305         }
1306         case AF_INET6: {
1307                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1308                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1309                 return (ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr)
1310                         && saddr6->sin6_scope_id == vaddr6->sin6_scope_id);
1311         }
1312         default:
1313                 WARN_ON(1);
1314                 return false; /* don't expect to be here */
1315         }
1316 }
1317
1318 /*
1319  * If no port is specified in addr structure, we try to match with 445 port
1320  * and if it fails - with 139 ports. It should be called only if address
1321  * families of server and addr are equal.
1322  */
1323 static bool
1324 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1325 {
1326         __be16 port, *sport;
1327
1328         /* SMBDirect manages its own ports, don't match it here */
1329         if (server->rdma)
1330                 return true;
1331
1332         switch (addr->sa_family) {
1333         case AF_INET:
1334                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1335                 port = ((struct sockaddr_in *) addr)->sin_port;
1336                 break;
1337         case AF_INET6:
1338                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1339                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1340                 break;
1341         default:
1342                 WARN_ON(1);
1343                 return false;
1344         }
1345
1346         if (!port) {
1347                 port = htons(CIFS_PORT);
1348                 if (port == *sport)
1349                         return true;
1350
1351                 port = htons(RFC1001_PORT);
1352         }
1353
1354         return port == *sport;
1355 }
1356
1357 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1358 {
1359         if (!cifs_match_ipaddr(addr, (struct sockaddr *)&server->dstaddr))
1360                 return false;
1361
1362         return true;
1363 }
1364
1365 static bool
1366 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1367 {
1368         /*
1369          * The select_sectype function should either return the ctx->sectype
1370          * that was specified, or "Unspecified" if that sectype was not
1371          * compatible with the given NEGOTIATE request.
1372          */
1373         if (server->ops->select_sectype(server, ctx->sectype)
1374              == Unspecified)
1375                 return false;
1376
1377         /*
1378          * Now check if signing mode is acceptable. No need to check
1379          * global_secflags at this point since if MUST_SIGN is set then
1380          * the server->sign had better be too.
1381          */
1382         if (ctx->sign && !server->sign)
1383                 return false;
1384
1385         return true;
1386 }
1387
1388 /* this function must be called with srv_lock held */
1389 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1390 {
1391         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1392
1393         lockdep_assert_held(&server->srv_lock);
1394
1395         if (ctx->nosharesock)
1396                 return 0;
1397
1398         /* this server does not share socket */
1399         if (server->nosharesock)
1400                 return 0;
1401
1402         /* If multidialect negotiation see if existing sessions match one */
1403         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1404                 if (server->vals->protocol_id < SMB30_PROT_ID)
1405                         return 0;
1406         } else if (strcmp(ctx->vals->version_string,
1407                    SMBDEFAULT_VERSION_STRING) == 0) {
1408                 if (server->vals->protocol_id < SMB21_PROT_ID)
1409                         return 0;
1410         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1411                 return 0;
1412
1413         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1414                 return 0;
1415
1416         if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1417                                (struct sockaddr *)&server->srcaddr))
1418                 return 0;
1419         /*
1420          * - Match for an DFS tcon (@server->origin_fullpath).
1421          * - Match for an DFS root server connection (@server->leaf_fullpath).
1422          * - If none of the above and @ctx->leaf_fullpath is set, then
1423          *   it is a new DFS connection.
1424          * - If 'nodfs' mount option was passed, then match only connections
1425          *   that have no DFS referrals set
1426          *   (e.g. can't failover to other targets).
1427          */
1428         if (!ctx->nodfs) {
1429                 if (ctx->source && server->origin_fullpath) {
1430                         if (!dfs_src_pathname_equal(ctx->source,
1431                                                     server->origin_fullpath))
1432                                 return 0;
1433                 } else if (server->leaf_fullpath) {
1434                         if (!ctx->leaf_fullpath ||
1435                             strcasecmp(server->leaf_fullpath,
1436                                        ctx->leaf_fullpath))
1437                                 return 0;
1438                 } else if (ctx->leaf_fullpath) {
1439                         return 0;
1440                 }
1441         } else if (server->origin_fullpath || server->leaf_fullpath) {
1442                 return 0;
1443         }
1444
1445         /*
1446          * Match for a regular connection (address/hostname/port) which has no
1447          * DFS referrals set.
1448          */
1449         if (!server->origin_fullpath && !server->leaf_fullpath &&
1450             (strcasecmp(server->hostname, ctx->server_hostname) ||
1451              !match_server_address(server, addr) ||
1452              !match_port(server, addr)))
1453                 return 0;
1454
1455         if (!match_security(server, ctx))
1456                 return 0;
1457
1458         if (server->echo_interval != ctx->echo_interval * HZ)
1459                 return 0;
1460
1461         if (server->rdma != ctx->rdma)
1462                 return 0;
1463
1464         if (server->ignore_signature != ctx->ignore_signature)
1465                 return 0;
1466
1467         if (server->min_offload != ctx->min_offload)
1468                 return 0;
1469
1470         return 1;
1471 }
1472
1473 struct TCP_Server_Info *
1474 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1475 {
1476         struct TCP_Server_Info *server;
1477
1478         spin_lock(&cifs_tcp_ses_lock);
1479         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1480                 spin_lock(&server->srv_lock);
1481                 /*
1482                  * Skip ses channels since they're only handled in lower layers
1483                  * (e.g. cifs_send_recv).
1484                  */
1485                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx)) {
1486                         spin_unlock(&server->srv_lock);
1487                         continue;
1488                 }
1489                 spin_unlock(&server->srv_lock);
1490
1491                 ++server->srv_count;
1492                 spin_unlock(&cifs_tcp_ses_lock);
1493                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1494                 return server;
1495         }
1496         spin_unlock(&cifs_tcp_ses_lock);
1497         return NULL;
1498 }
1499
1500 void
1501 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1502 {
1503         struct task_struct *task;
1504
1505         spin_lock(&cifs_tcp_ses_lock);
1506         if (--server->srv_count > 0) {
1507                 spin_unlock(&cifs_tcp_ses_lock);
1508                 return;
1509         }
1510
1511         /* srv_count can never go negative */
1512         WARN_ON(server->srv_count < 0);
1513
1514         put_net(cifs_net_ns(server));
1515
1516         list_del_init(&server->tcp_ses_list);
1517         spin_unlock(&cifs_tcp_ses_lock);
1518
1519         /* For secondary channels, we pick up ref-count on the primary server */
1520         if (CIFS_SERVER_IS_CHAN(server))
1521                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1522
1523         cancel_delayed_work_sync(&server->echo);
1524
1525         if (from_reconnect)
1526                 /*
1527                  * Avoid deadlock here: reconnect work calls
1528                  * cifs_put_tcp_session() at its end. Need to be sure
1529                  * that reconnect work does nothing with server pointer after
1530                  * that step.
1531                  */
1532                 cancel_delayed_work(&server->reconnect);
1533         else
1534                 cancel_delayed_work_sync(&server->reconnect);
1535
1536         spin_lock(&server->srv_lock);
1537         server->tcpStatus = CifsExiting;
1538         spin_unlock(&server->srv_lock);
1539
1540         cifs_crypto_secmech_release(server);
1541
1542         kfree_sensitive(server->session_key.response);
1543         server->session_key.response = NULL;
1544         server->session_key.len = 0;
1545         kfree(server->hostname);
1546         server->hostname = NULL;
1547
1548         task = xchg(&server->tsk, NULL);
1549         if (task)
1550                 send_sig(SIGKILL, task, 1);
1551 }
1552
1553 struct TCP_Server_Info *
1554 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1555                      struct TCP_Server_Info *primary_server)
1556 {
1557         struct TCP_Server_Info *tcp_ses = NULL;
1558         int rc;
1559
1560         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1561
1562         /* see if we already have a matching tcp_ses */
1563         tcp_ses = cifs_find_tcp_session(ctx);
1564         if (tcp_ses)
1565                 return tcp_ses;
1566
1567         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1568         if (!tcp_ses) {
1569                 rc = -ENOMEM;
1570                 goto out_err;
1571         }
1572
1573         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1574         if (!tcp_ses->hostname) {
1575                 rc = -ENOMEM;
1576                 goto out_err;
1577         }
1578
1579         if (ctx->leaf_fullpath) {
1580                 tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1581                 if (!tcp_ses->leaf_fullpath) {
1582                         rc = -ENOMEM;
1583                         goto out_err;
1584                 }
1585         }
1586
1587         if (ctx->nosharesock)
1588                 tcp_ses->nosharesock = true;
1589
1590         tcp_ses->ops = ctx->ops;
1591         tcp_ses->vals = ctx->vals;
1592         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1593
1594         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1595         tcp_ses->noblockcnt = ctx->rootfs;
1596         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1597         tcp_ses->noautotune = ctx->noautotune;
1598         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1599         tcp_ses->rdma = ctx->rdma;
1600         tcp_ses->in_flight = 0;
1601         tcp_ses->max_in_flight = 0;
1602         tcp_ses->credits = 1;
1603         if (primary_server) {
1604                 spin_lock(&cifs_tcp_ses_lock);
1605                 ++primary_server->srv_count;
1606                 spin_unlock(&cifs_tcp_ses_lock);
1607                 tcp_ses->primary_server = primary_server;
1608         }
1609         init_waitqueue_head(&tcp_ses->response_q);
1610         init_waitqueue_head(&tcp_ses->request_q);
1611         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1612         mutex_init(&tcp_ses->_srv_mutex);
1613         memcpy(tcp_ses->workstation_RFC1001_name,
1614                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1615         memcpy(tcp_ses->server_RFC1001_name,
1616                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1617         tcp_ses->session_estab = false;
1618         tcp_ses->sequence_number = 0;
1619         tcp_ses->reconnect_instance = 1;
1620         tcp_ses->lstrp = jiffies;
1621         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1622         spin_lock_init(&tcp_ses->req_lock);
1623         spin_lock_init(&tcp_ses->srv_lock);
1624         spin_lock_init(&tcp_ses->mid_lock);
1625         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1626         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1627         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1628         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1629         mutex_init(&tcp_ses->reconnect_mutex);
1630 #ifdef CONFIG_CIFS_DFS_UPCALL
1631         mutex_init(&tcp_ses->refpath_lock);
1632 #endif
1633         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1634                sizeof(tcp_ses->srcaddr));
1635         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1636                 sizeof(tcp_ses->dstaddr));
1637         if (ctx->use_client_guid)
1638                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1639                        SMB2_CLIENT_GUID_SIZE);
1640         else
1641                 generate_random_uuid(tcp_ses->client_guid);
1642         /*
1643          * at this point we are the only ones with the pointer
1644          * to the struct since the kernel thread not created yet
1645          * no need to spinlock this init of tcpStatus or srv_count
1646          */
1647         tcp_ses->tcpStatus = CifsNew;
1648         ++tcp_ses->srv_count;
1649
1650         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1651                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1652                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1653         else
1654                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1655         if (tcp_ses->rdma) {
1656 #ifndef CONFIG_CIFS_SMB_DIRECT
1657                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1658                 rc = -ENOENT;
1659                 goto out_err_crypto_release;
1660 #endif
1661                 tcp_ses->smbd_conn = smbd_get_connection(
1662                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1663                 if (tcp_ses->smbd_conn) {
1664                         cifs_dbg(VFS, "RDMA transport established\n");
1665                         rc = 0;
1666                         goto smbd_connected;
1667                 } else {
1668                         rc = -ENOENT;
1669                         goto out_err_crypto_release;
1670                 }
1671         }
1672         rc = ip_connect(tcp_ses);
1673         if (rc < 0) {
1674                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1675                 goto out_err_crypto_release;
1676         }
1677 smbd_connected:
1678         /*
1679          * since we're in a cifs function already, we know that
1680          * this will succeed. No need for try_module_get().
1681          */
1682         __module_get(THIS_MODULE);
1683         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1684                                   tcp_ses, "cifsd");
1685         if (IS_ERR(tcp_ses->tsk)) {
1686                 rc = PTR_ERR(tcp_ses->tsk);
1687                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1688                 module_put(THIS_MODULE);
1689                 goto out_err_crypto_release;
1690         }
1691         tcp_ses->min_offload = ctx->min_offload;
1692         /*
1693          * at this point we are the only ones with the pointer
1694          * to the struct since the kernel thread not created yet
1695          * no need to spinlock this update of tcpStatus
1696          */
1697         spin_lock(&tcp_ses->srv_lock);
1698         tcp_ses->tcpStatus = CifsNeedNegotiate;
1699         spin_unlock(&tcp_ses->srv_lock);
1700
1701         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1702                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1703         else
1704                 tcp_ses->max_credits = ctx->max_credits;
1705
1706         tcp_ses->nr_targets = 1;
1707         tcp_ses->ignore_signature = ctx->ignore_signature;
1708         /* thread spawned, put it on the list */
1709         spin_lock(&cifs_tcp_ses_lock);
1710         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1711         spin_unlock(&cifs_tcp_ses_lock);
1712
1713         /* queue echo request delayed work */
1714         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1715
1716         return tcp_ses;
1717
1718 out_err_crypto_release:
1719         cifs_crypto_secmech_release(tcp_ses);
1720
1721         put_net(cifs_net_ns(tcp_ses));
1722
1723 out_err:
1724         if (tcp_ses) {
1725                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1726                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1727                 kfree(tcp_ses->hostname);
1728                 kfree(tcp_ses->leaf_fullpath);
1729                 if (tcp_ses->ssocket)
1730                         sock_release(tcp_ses->ssocket);
1731                 kfree(tcp_ses);
1732         }
1733         return ERR_PTR(rc);
1734 }
1735
1736 /* this function must be called with ses_lock and chan_lock held */
1737 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1738 {
1739         if (ctx->sectype != Unspecified &&
1740             ctx->sectype != ses->sectype)
1741                 return 0;
1742
1743         /*
1744          * If an existing session is limited to less channels than
1745          * requested, it should not be reused
1746          */
1747         if (ses->chan_max < ctx->max_channels)
1748                 return 0;
1749
1750         switch (ses->sectype) {
1751         case Kerberos:
1752                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1753                         return 0;
1754                 break;
1755         default:
1756                 /* NULL username means anonymous session */
1757                 if (ses->user_name == NULL) {
1758                         if (!ctx->nullauth)
1759                                 return 0;
1760                         break;
1761                 }
1762
1763                 /* anything else takes username/password */
1764                 if (strncmp(ses->user_name,
1765                             ctx->username ? ctx->username : "",
1766                             CIFS_MAX_USERNAME_LEN))
1767                         return 0;
1768                 if ((ctx->username && strlen(ctx->username) != 0) &&
1769                     ses->password != NULL &&
1770                     strncmp(ses->password,
1771                             ctx->password ? ctx->password : "",
1772                             CIFS_MAX_PASSWORD_LEN))
1773                         return 0;
1774         }
1775         return 1;
1776 }
1777
1778 /**
1779  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1780  * @ses: smb session to issue the request on
1781  * @ctx: the superblock configuration context to use for building the
1782  *       new tree connection for the IPC (interprocess communication RPC)
1783  *
1784  * A new IPC connection is made and stored in the session
1785  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1786  */
1787 static int
1788 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1789 {
1790         int rc = 0, xid;
1791         struct cifs_tcon *tcon;
1792         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1793         bool seal = false;
1794         struct TCP_Server_Info *server = ses->server;
1795
1796         /*
1797          * If the mount request that resulted in the creation of the
1798          * session requires encryption, force IPC to be encrypted too.
1799          */
1800         if (ctx->seal) {
1801                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1802                         seal = true;
1803                 else {
1804                         cifs_server_dbg(VFS,
1805                                  "IPC: server doesn't support encryption\n");
1806                         return -EOPNOTSUPP;
1807                 }
1808         }
1809
1810         tcon = tconInfoAlloc();
1811         if (tcon == NULL)
1812                 return -ENOMEM;
1813
1814         spin_lock(&server->srv_lock);
1815         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1816         spin_unlock(&server->srv_lock);
1817
1818         xid = get_xid();
1819         tcon->ses = ses;
1820         tcon->ipc = true;
1821         tcon->seal = seal;
1822         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1823         free_xid(xid);
1824
1825         if (rc) {
1826                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1827                 tconInfoFree(tcon);
1828                 goto out;
1829         }
1830
1831         cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1832
1833         spin_lock(&tcon->tc_lock);
1834         tcon->status = TID_GOOD;
1835         spin_unlock(&tcon->tc_lock);
1836         ses->tcon_ipc = tcon;
1837 out:
1838         return rc;
1839 }
1840
1841 /**
1842  * cifs_free_ipc - helper to release the session IPC tcon
1843  * @ses: smb session to unmount the IPC from
1844  *
1845  * Needs to be called everytime a session is destroyed.
1846  *
1847  * On session close, the IPC is closed and the server must release all tcons of the session.
1848  * No need to send a tree disconnect here.
1849  *
1850  * Besides, it will make the server to not close durable and resilient files on session close, as
1851  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1852  */
1853 static int
1854 cifs_free_ipc(struct cifs_ses *ses)
1855 {
1856         struct cifs_tcon *tcon = ses->tcon_ipc;
1857
1858         if (tcon == NULL)
1859                 return 0;
1860
1861         tconInfoFree(tcon);
1862         ses->tcon_ipc = NULL;
1863         return 0;
1864 }
1865
1866 static struct cifs_ses *
1867 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1868 {
1869         struct cifs_ses *ses, *ret = NULL;
1870
1871         spin_lock(&cifs_tcp_ses_lock);
1872         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1873                 spin_lock(&ses->ses_lock);
1874                 if (ses->ses_status == SES_EXITING) {
1875                         spin_unlock(&ses->ses_lock);
1876                         continue;
1877                 }
1878                 spin_lock(&ses->chan_lock);
1879                 if (match_session(ses, ctx)) {
1880                         spin_unlock(&ses->chan_lock);
1881                         spin_unlock(&ses->ses_lock);
1882                         ret = ses;
1883                         break;
1884                 }
1885                 spin_unlock(&ses->chan_lock);
1886                 spin_unlock(&ses->ses_lock);
1887         }
1888         if (ret)
1889                 cifs_smb_ses_inc_refcount(ret);
1890         spin_unlock(&cifs_tcp_ses_lock);
1891         return ret;
1892 }
1893
1894 void __cifs_put_smb_ses(struct cifs_ses *ses)
1895 {
1896         unsigned int rc, xid;
1897         unsigned int chan_count;
1898         struct TCP_Server_Info *server = ses->server;
1899
1900         spin_lock(&ses->ses_lock);
1901         if (ses->ses_status == SES_EXITING) {
1902                 spin_unlock(&ses->ses_lock);
1903                 return;
1904         }
1905         spin_unlock(&ses->ses_lock);
1906
1907         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1908         cifs_dbg(FYI,
1909                  "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1910
1911         spin_lock(&cifs_tcp_ses_lock);
1912         if (--ses->ses_count > 0) {
1913                 spin_unlock(&cifs_tcp_ses_lock);
1914                 return;
1915         }
1916         spin_unlock(&cifs_tcp_ses_lock);
1917
1918         /* ses_count can never go negative */
1919         WARN_ON(ses->ses_count < 0);
1920
1921         spin_lock(&ses->ses_lock);
1922         if (ses->ses_status == SES_GOOD)
1923                 ses->ses_status = SES_EXITING;
1924
1925         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1926                 spin_unlock(&ses->ses_lock);
1927                 cifs_free_ipc(ses);
1928                 xid = get_xid();
1929                 rc = server->ops->logoff(xid, ses);
1930                 if (rc)
1931                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1932                                 __func__, rc);
1933                 _free_xid(xid);
1934         } else {
1935                 spin_unlock(&ses->ses_lock);
1936                 cifs_free_ipc(ses);
1937         }
1938
1939         spin_lock(&cifs_tcp_ses_lock);
1940         list_del_init(&ses->smb_ses_list);
1941         spin_unlock(&cifs_tcp_ses_lock);
1942
1943         chan_count = ses->chan_count;
1944
1945         /* close any extra channels */
1946         if (chan_count > 1) {
1947                 int i;
1948
1949                 for (i = 1; i < chan_count; i++) {
1950                         if (ses->chans[i].iface) {
1951                                 kref_put(&ses->chans[i].iface->refcount, release_iface);
1952                                 ses->chans[i].iface = NULL;
1953                         }
1954                         cifs_put_tcp_session(ses->chans[i].server, 0);
1955                         ses->chans[i].server = NULL;
1956                 }
1957         }
1958
1959         sesInfoFree(ses);
1960         cifs_put_tcp_session(server, 0);
1961 }
1962
1963 #ifdef CONFIG_KEYS
1964
1965 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1966 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1967
1968 /* Populate username and pw fields from keyring if possible */
1969 static int
1970 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1971 {
1972         int rc = 0;
1973         int is_domain = 0;
1974         const char *delim, *payload;
1975         char *desc;
1976         ssize_t len;
1977         struct key *key;
1978         struct TCP_Server_Info *server = ses->server;
1979         struct sockaddr_in *sa;
1980         struct sockaddr_in6 *sa6;
1981         const struct user_key_payload *upayload;
1982
1983         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1984         if (!desc)
1985                 return -ENOMEM;
1986
1987         /* try to find an address key first */
1988         switch (server->dstaddr.ss_family) {
1989         case AF_INET:
1990                 sa = (struct sockaddr_in *)&server->dstaddr;
1991                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1992                 break;
1993         case AF_INET6:
1994                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1995                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1996                 break;
1997         default:
1998                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1999                          server->dstaddr.ss_family);
2000                 rc = -EINVAL;
2001                 goto out_err;
2002         }
2003
2004         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2005         key = request_key(&key_type_logon, desc, "");
2006         if (IS_ERR(key)) {
2007                 if (!ses->domainName) {
2008                         cifs_dbg(FYI, "domainName is NULL\n");
2009                         rc = PTR_ERR(key);
2010                         goto out_err;
2011                 }
2012
2013                 /* didn't work, try to find a domain key */
2014                 sprintf(desc, "cifs:d:%s", ses->domainName);
2015                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2016                 key = request_key(&key_type_logon, desc, "");
2017                 if (IS_ERR(key)) {
2018                         rc = PTR_ERR(key);
2019                         goto out_err;
2020                 }
2021                 is_domain = 1;
2022         }
2023
2024         down_read(&key->sem);
2025         upayload = user_key_payload_locked(key);
2026         if (IS_ERR_OR_NULL(upayload)) {
2027                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2028                 goto out_key_put;
2029         }
2030
2031         /* find first : in payload */
2032         payload = upayload->data;
2033         delim = strnchr(payload, upayload->datalen, ':');
2034         cifs_dbg(FYI, "payload=%s\n", payload);
2035         if (!delim) {
2036                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2037                          upayload->datalen);
2038                 rc = -EINVAL;
2039                 goto out_key_put;
2040         }
2041
2042         len = delim - payload;
2043         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2044                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2045                          len);
2046                 rc = -EINVAL;
2047                 goto out_key_put;
2048         }
2049
2050         ctx->username = kstrndup(payload, len, GFP_KERNEL);
2051         if (!ctx->username) {
2052                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2053                          len);
2054                 rc = -ENOMEM;
2055                 goto out_key_put;
2056         }
2057         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2058
2059         len = key->datalen - (len + 1);
2060         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2061                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2062                 rc = -EINVAL;
2063                 kfree(ctx->username);
2064                 ctx->username = NULL;
2065                 goto out_key_put;
2066         }
2067
2068         ++delim;
2069         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2070         if (!ctx->password) {
2071                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2072                          len);
2073                 rc = -ENOMEM;
2074                 kfree(ctx->username);
2075                 ctx->username = NULL;
2076                 goto out_key_put;
2077         }
2078
2079         /*
2080          * If we have a domain key then we must set the domainName in the
2081          * for the request.
2082          */
2083         if (is_domain && ses->domainName) {
2084                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2085                 if (!ctx->domainname) {
2086                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2087                                  len);
2088                         rc = -ENOMEM;
2089                         kfree(ctx->username);
2090                         ctx->username = NULL;
2091                         kfree_sensitive(ctx->password);
2092                         ctx->password = NULL;
2093                         goto out_key_put;
2094                 }
2095         }
2096
2097         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2098
2099 out_key_put:
2100         up_read(&key->sem);
2101         key_put(key);
2102 out_err:
2103         kfree(desc);
2104         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2105         return rc;
2106 }
2107 #else /* ! CONFIG_KEYS */
2108 static inline int
2109 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2110                    struct cifs_ses *ses __attribute__((unused)))
2111 {
2112         return -ENOSYS;
2113 }
2114 #endif /* CONFIG_KEYS */
2115
2116 /**
2117  * cifs_get_smb_ses - get a session matching @ctx data from @server
2118  * @server: server to setup the session to
2119  * @ctx: superblock configuration context to use to setup the session
2120  *
2121  * This function assumes it is being called from cifs_mount() where we
2122  * already got a server reference (server refcount +1). See
2123  * cifs_get_tcon() for refcount explanations.
2124  */
2125 struct cifs_ses *
2126 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2127 {
2128         int rc = 0;
2129         unsigned int xid;
2130         struct cifs_ses *ses;
2131         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2132         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2133
2134         xid = get_xid();
2135
2136         ses = cifs_find_smb_ses(server, ctx);
2137         if (ses) {
2138                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2139                          ses->ses_status);
2140
2141                 spin_lock(&ses->chan_lock);
2142                 if (cifs_chan_needs_reconnect(ses, server)) {
2143                         spin_unlock(&ses->chan_lock);
2144                         cifs_dbg(FYI, "Session needs reconnect\n");
2145
2146                         mutex_lock(&ses->session_mutex);
2147                         rc = cifs_negotiate_protocol(xid, ses, server);
2148                         if (rc) {
2149                                 mutex_unlock(&ses->session_mutex);
2150                                 /* problem -- put our ses reference */
2151                                 cifs_put_smb_ses(ses);
2152                                 free_xid(xid);
2153                                 return ERR_PTR(rc);
2154                         }
2155
2156                         rc = cifs_setup_session(xid, ses, server,
2157                                                 ctx->local_nls);
2158                         if (rc) {
2159                                 mutex_unlock(&ses->session_mutex);
2160                                 /* problem -- put our reference */
2161                                 cifs_put_smb_ses(ses);
2162                                 free_xid(xid);
2163                                 return ERR_PTR(rc);
2164                         }
2165                         mutex_unlock(&ses->session_mutex);
2166
2167                         spin_lock(&ses->chan_lock);
2168                 }
2169                 spin_unlock(&ses->chan_lock);
2170
2171                 /* existing SMB ses has a server reference already */
2172                 cifs_put_tcp_session(server, 0);
2173                 free_xid(xid);
2174                 return ses;
2175         }
2176
2177         rc = -ENOMEM;
2178
2179         cifs_dbg(FYI, "Existing smb sess not found\n");
2180         ses = sesInfoAlloc();
2181         if (ses == NULL)
2182                 goto get_ses_fail;
2183
2184         /* new SMB session uses our server ref */
2185         ses->server = server;
2186         if (server->dstaddr.ss_family == AF_INET6)
2187                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2188         else
2189                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2190
2191         if (ctx->username) {
2192                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2193                 if (!ses->user_name)
2194                         goto get_ses_fail;
2195         }
2196
2197         /* ctx->password freed at unmount */
2198         if (ctx->password) {
2199                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2200                 if (!ses->password)
2201                         goto get_ses_fail;
2202         }
2203         if (ctx->domainname) {
2204                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2205                 if (!ses->domainName)
2206                         goto get_ses_fail;
2207         }
2208
2209         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2210
2211         if (ctx->domainauto)
2212                 ses->domainAuto = ctx->domainauto;
2213         ses->cred_uid = ctx->cred_uid;
2214         ses->linux_uid = ctx->linux_uid;
2215
2216         ses->sectype = ctx->sectype;
2217         ses->sign = ctx->sign;
2218
2219         /* add server as first channel */
2220         spin_lock(&ses->chan_lock);
2221         ses->chans[0].server = server;
2222         ses->chan_count = 1;
2223         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2224         ses->chans_need_reconnect = 1;
2225         spin_unlock(&ses->chan_lock);
2226
2227         mutex_lock(&ses->session_mutex);
2228         rc = cifs_negotiate_protocol(xid, ses, server);
2229         if (!rc)
2230                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2231         mutex_unlock(&ses->session_mutex);
2232
2233         /* each channel uses a different signing key */
2234         spin_lock(&ses->chan_lock);
2235         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2236                sizeof(ses->smb3signingkey));
2237         spin_unlock(&ses->chan_lock);
2238
2239         if (rc)
2240                 goto get_ses_fail;
2241
2242         /*
2243          * success, put it on the list and add it as first channel
2244          * note: the session becomes active soon after this. So you'll
2245          * need to lock before changing something in the session.
2246          */
2247         spin_lock(&cifs_tcp_ses_lock);
2248         ses->dfs_root_ses = ctx->dfs_root_ses;
2249         if (ses->dfs_root_ses)
2250                 ses->dfs_root_ses->ses_count++;
2251         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2252         spin_unlock(&cifs_tcp_ses_lock);
2253
2254         cifs_setup_ipc(ses, ctx);
2255
2256         free_xid(xid);
2257
2258         return ses;
2259
2260 get_ses_fail:
2261         sesInfoFree(ses);
2262         free_xid(xid);
2263         return ERR_PTR(rc);
2264 }
2265
2266 /* this function must be called with tc_lock held */
2267 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2268 {
2269         struct TCP_Server_Info *server = tcon->ses->server;
2270
2271         if (tcon->status == TID_EXITING)
2272                 return 0;
2273         /* Skip UNC validation when matching DFS connections or superblocks */
2274         if (!server->origin_fullpath && !server->leaf_fullpath &&
2275             strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2276                 return 0;
2277         if (tcon->seal != ctx->seal)
2278                 return 0;
2279         if (tcon->snapshot_time != ctx->snapshot_time)
2280                 return 0;
2281         if (tcon->handle_timeout != ctx->handle_timeout)
2282                 return 0;
2283         if (tcon->no_lease != ctx->no_lease)
2284                 return 0;
2285         if (tcon->nodelete != ctx->nodelete)
2286                 return 0;
2287         return 1;
2288 }
2289
2290 static struct cifs_tcon *
2291 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2292 {
2293         struct cifs_tcon *tcon;
2294
2295         spin_lock(&cifs_tcp_ses_lock);
2296         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2297                 spin_lock(&tcon->tc_lock);
2298                 if (!match_tcon(tcon, ctx)) {
2299                         spin_unlock(&tcon->tc_lock);
2300                         continue;
2301                 }
2302                 ++tcon->tc_count;
2303                 spin_unlock(&tcon->tc_lock);
2304                 spin_unlock(&cifs_tcp_ses_lock);
2305                 return tcon;
2306         }
2307         spin_unlock(&cifs_tcp_ses_lock);
2308         return NULL;
2309 }
2310
2311 void
2312 cifs_put_tcon(struct cifs_tcon *tcon)
2313 {
2314         unsigned int xid;
2315         struct cifs_ses *ses;
2316
2317         /*
2318          * IPC tcon share the lifetime of their session and are
2319          * destroyed in the session put function
2320          */
2321         if (tcon == NULL || tcon->ipc)
2322                 return;
2323
2324         ses = tcon->ses;
2325         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2326         spin_lock(&cifs_tcp_ses_lock);
2327         spin_lock(&tcon->tc_lock);
2328         if (--tcon->tc_count > 0) {
2329                 spin_unlock(&tcon->tc_lock);
2330                 spin_unlock(&cifs_tcp_ses_lock);
2331                 return;
2332         }
2333
2334         /* tc_count can never go negative */
2335         WARN_ON(tcon->tc_count < 0);
2336
2337         list_del_init(&tcon->tcon_list);
2338         tcon->status = TID_EXITING;
2339         spin_unlock(&tcon->tc_lock);
2340         spin_unlock(&cifs_tcp_ses_lock);
2341
2342         /* cancel polling of interfaces */
2343         cancel_delayed_work_sync(&tcon->query_interfaces);
2344 #ifdef CONFIG_CIFS_DFS_UPCALL
2345         cancel_delayed_work_sync(&tcon->dfs_cache_work);
2346 #endif
2347
2348         if (tcon->use_witness) {
2349                 int rc;
2350
2351                 rc = cifs_swn_unregister(tcon);
2352                 if (rc < 0) {
2353                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2354                                         __func__, rc);
2355                 }
2356         }
2357
2358         xid = get_xid();
2359         if (ses->server->ops->tree_disconnect)
2360                 ses->server->ops->tree_disconnect(xid, tcon);
2361         _free_xid(xid);
2362
2363         cifs_fscache_release_super_cookie(tcon);
2364         tconInfoFree(tcon);
2365         cifs_put_smb_ses(ses);
2366 }
2367
2368 /**
2369  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2370  * @ses: smb session to issue the request on
2371  * @ctx: the superblock configuration context to use for building the
2372  *
2373  * - tcon refcount is the number of mount points using the tcon.
2374  * - ses refcount is the number of tcon using the session.
2375  *
2376  * 1. This function assumes it is being called from cifs_mount() where
2377  *    we already got a session reference (ses refcount +1).
2378  *
2379  * 2. Since we're in the context of adding a mount point, the end
2380  *    result should be either:
2381  *
2382  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2383  *    its session refcount incremented (1 new tcon). This +1 was
2384  *    already done in (1).
2385  *
2386  * b) an existing tcon with refcount+1 (add a mount point to it) and
2387  *    identical ses refcount (no new tcon). Because of (1) we need to
2388  *    decrement the ses refcount.
2389  */
2390 static struct cifs_tcon *
2391 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2392 {
2393         int rc, xid;
2394         struct cifs_tcon *tcon;
2395
2396         tcon = cifs_find_tcon(ses, ctx);
2397         if (tcon) {
2398                 /*
2399                  * tcon has refcount already incremented but we need to
2400                  * decrement extra ses reference gotten by caller (case b)
2401                  */
2402                 cifs_dbg(FYI, "Found match on UNC path\n");
2403                 cifs_put_smb_ses(ses);
2404                 return tcon;
2405         }
2406
2407         if (!ses->server->ops->tree_connect) {
2408                 rc = -ENOSYS;
2409                 goto out_fail;
2410         }
2411
2412         tcon = tconInfoAlloc();
2413         if (tcon == NULL) {
2414                 rc = -ENOMEM;
2415                 goto out_fail;
2416         }
2417
2418         if (ctx->snapshot_time) {
2419                 if (ses->server->vals->protocol_id == 0) {
2420                         cifs_dbg(VFS,
2421                              "Use SMB2 or later for snapshot mount option\n");
2422                         rc = -EOPNOTSUPP;
2423                         goto out_fail;
2424                 } else
2425                         tcon->snapshot_time = ctx->snapshot_time;
2426         }
2427
2428         if (ctx->handle_timeout) {
2429                 if (ses->server->vals->protocol_id == 0) {
2430                         cifs_dbg(VFS,
2431                              "Use SMB2.1 or later for handle timeout option\n");
2432                         rc = -EOPNOTSUPP;
2433                         goto out_fail;
2434                 } else
2435                         tcon->handle_timeout = ctx->handle_timeout;
2436         }
2437
2438         tcon->ses = ses;
2439         if (ctx->password) {
2440                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2441                 if (!tcon->password) {
2442                         rc = -ENOMEM;
2443                         goto out_fail;
2444                 }
2445         }
2446
2447         if (ctx->seal) {
2448                 if (ses->server->vals->protocol_id == 0) {
2449                         cifs_dbg(VFS,
2450                                  "SMB3 or later required for encryption\n");
2451                         rc = -EOPNOTSUPP;
2452                         goto out_fail;
2453                 } else if (tcon->ses->server->capabilities &
2454                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2455                         tcon->seal = true;
2456                 else {
2457                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2458                         rc = -EOPNOTSUPP;
2459                         goto out_fail;
2460                 }
2461         }
2462
2463         if (ctx->linux_ext) {
2464                 if (ses->server->posix_ext_supported) {
2465                         tcon->posix_extensions = true;
2466                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2467                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2468                     (strcmp(ses->server->vals->version_string,
2469                      SMB3ANY_VERSION_STRING) == 0) ||
2470                     (strcmp(ses->server->vals->version_string,
2471                      SMBDEFAULT_VERSION_STRING) == 0)) {
2472                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2473                         rc = -EOPNOTSUPP;
2474                         goto out_fail;
2475                 } else {
2476                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2477                                 "disabled but required for POSIX extensions\n");
2478                         rc = -EOPNOTSUPP;
2479                         goto out_fail;
2480                 }
2481         }
2482
2483         xid = get_xid();
2484         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2485                                             ctx->local_nls);
2486         free_xid(xid);
2487         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2488         if (rc)
2489                 goto out_fail;
2490
2491         tcon->use_persistent = false;
2492         /* check if SMB2 or later, CIFS does not support persistent handles */
2493         if (ctx->persistent) {
2494                 if (ses->server->vals->protocol_id == 0) {
2495                         cifs_dbg(VFS,
2496                              "SMB3 or later required for persistent handles\n");
2497                         rc = -EOPNOTSUPP;
2498                         goto out_fail;
2499                 } else if (ses->server->capabilities &
2500                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2501                         tcon->use_persistent = true;
2502                 else /* persistent handles requested but not supported */ {
2503                         cifs_dbg(VFS,
2504                                 "Persistent handles not supported on share\n");
2505                         rc = -EOPNOTSUPP;
2506                         goto out_fail;
2507                 }
2508         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2509              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2510              && (ctx->nopersistent == false)) {
2511                 cifs_dbg(FYI, "enabling persistent handles\n");
2512                 tcon->use_persistent = true;
2513         } else if (ctx->resilient) {
2514                 if (ses->server->vals->protocol_id == 0) {
2515                         cifs_dbg(VFS,
2516                              "SMB2.1 or later required for resilient handles\n");
2517                         rc = -EOPNOTSUPP;
2518                         goto out_fail;
2519                 }
2520                 tcon->use_resilient = true;
2521         }
2522
2523         tcon->use_witness = false;
2524         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2525                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2526                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2527                                 /*
2528                                  * Set witness in use flag in first place
2529                                  * to retry registration in the echo task
2530                                  */
2531                                 tcon->use_witness = true;
2532                                 /* And try to register immediately */
2533                                 rc = cifs_swn_register(tcon);
2534                                 if (rc < 0) {
2535                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2536                                         goto out_fail;
2537                                 }
2538                         } else {
2539                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2540                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2541                                 rc = -EOPNOTSUPP;
2542                                 goto out_fail;
2543                         }
2544                 } else {
2545                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2546                         rc = -EOPNOTSUPP;
2547                         goto out_fail;
2548                 }
2549         }
2550
2551         /* If the user really knows what they are doing they can override */
2552         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2553                 if (ctx->cache_ro)
2554                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2555                 else if (ctx->cache_rw)
2556                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2557         }
2558
2559         if (ctx->no_lease) {
2560                 if (ses->server->vals->protocol_id == 0) {
2561                         cifs_dbg(VFS,
2562                                 "SMB2 or later required for nolease option\n");
2563                         rc = -EOPNOTSUPP;
2564                         goto out_fail;
2565                 } else
2566                         tcon->no_lease = ctx->no_lease;
2567         }
2568
2569         /*
2570          * We can have only one retry value for a connection to a share so for
2571          * resources mounted more than once to the same server share the last
2572          * value passed in for the retry flag is used.
2573          */
2574         tcon->retry = ctx->retry;
2575         tcon->nocase = ctx->nocase;
2576         tcon->broken_sparse_sup = ctx->no_sparse;
2577         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2578                 tcon->nohandlecache = ctx->nohandlecache;
2579         else
2580                 tcon->nohandlecache = true;
2581         tcon->nodelete = ctx->nodelete;
2582         tcon->local_lease = ctx->local_lease;
2583         INIT_LIST_HEAD(&tcon->pending_opens);
2584         tcon->status = TID_GOOD;
2585
2586         INIT_DELAYED_WORK(&tcon->query_interfaces,
2587                           smb2_query_server_interfaces);
2588         if (ses->server->dialect >= SMB30_PROT_ID &&
2589             (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2590                 /* schedule query interfaces poll */
2591                 queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2592                                    (SMB_INTERFACE_POLL_INTERVAL * HZ));
2593         }
2594 #ifdef CONFIG_CIFS_DFS_UPCALL
2595         INIT_DELAYED_WORK(&tcon->dfs_cache_work, dfs_cache_refresh);
2596 #endif
2597         spin_lock(&cifs_tcp_ses_lock);
2598         list_add(&tcon->tcon_list, &ses->tcon_list);
2599         spin_unlock(&cifs_tcp_ses_lock);
2600
2601         return tcon;
2602
2603 out_fail:
2604         tconInfoFree(tcon);
2605         return ERR_PTR(rc);
2606 }
2607
2608 void
2609 cifs_put_tlink(struct tcon_link *tlink)
2610 {
2611         if (!tlink || IS_ERR(tlink))
2612                 return;
2613
2614         if (!atomic_dec_and_test(&tlink->tl_count) ||
2615             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2616                 tlink->tl_time = jiffies;
2617                 return;
2618         }
2619
2620         if (!IS_ERR(tlink_tcon(tlink)))
2621                 cifs_put_tcon(tlink_tcon(tlink));
2622         kfree(tlink);
2623         return;
2624 }
2625
2626 static int
2627 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2628 {
2629         struct cifs_sb_info *old = CIFS_SB(sb);
2630         struct cifs_sb_info *new = mnt_data->cifs_sb;
2631         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2632         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2633
2634         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2635                 return 0;
2636
2637         if (old->mnt_cifs_serverino_autodisabled)
2638                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2639
2640         if (oldflags != newflags)
2641                 return 0;
2642
2643         /*
2644          * We want to share sb only if we don't specify an r/wsize or
2645          * specified r/wsize is greater than or equal to existing one.
2646          */
2647         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2648                 return 0;
2649
2650         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2651                 return 0;
2652
2653         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2654             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2655                 return 0;
2656
2657         if (old->ctx->file_mode != new->ctx->file_mode ||
2658             old->ctx->dir_mode != new->ctx->dir_mode)
2659                 return 0;
2660
2661         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2662                 return 0;
2663
2664         if (old->ctx->acregmax != new->ctx->acregmax)
2665                 return 0;
2666         if (old->ctx->acdirmax != new->ctx->acdirmax)
2667                 return 0;
2668         if (old->ctx->closetimeo != new->ctx->closetimeo)
2669                 return 0;
2670
2671         return 1;
2672 }
2673
2674 static int match_prepath(struct super_block *sb,
2675                          struct TCP_Server_Info *server,
2676                          struct cifs_mnt_data *mnt_data)
2677 {
2678         struct smb3_fs_context *ctx = mnt_data->ctx;
2679         struct cifs_sb_info *old = CIFS_SB(sb);
2680         struct cifs_sb_info *new = mnt_data->cifs_sb;
2681         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2682                 old->prepath;
2683         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2684                 new->prepath;
2685
2686         if (server->origin_fullpath &&
2687             dfs_src_pathname_equal(server->origin_fullpath, ctx->source))
2688                 return 1;
2689
2690         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2691                 return 1;
2692         else if (!old_set && !new_set)
2693                 return 1;
2694
2695         return 0;
2696 }
2697
2698 int
2699 cifs_match_super(struct super_block *sb, void *data)
2700 {
2701         struct cifs_mnt_data *mnt_data = data;
2702         struct smb3_fs_context *ctx;
2703         struct cifs_sb_info *cifs_sb;
2704         struct TCP_Server_Info *tcp_srv;
2705         struct cifs_ses *ses;
2706         struct cifs_tcon *tcon;
2707         struct tcon_link *tlink;
2708         int rc = 0;
2709
2710         spin_lock(&cifs_tcp_ses_lock);
2711         cifs_sb = CIFS_SB(sb);
2712
2713         /* We do not want to use a superblock that has been shutdown */
2714         if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
2715                 spin_unlock(&cifs_tcp_ses_lock);
2716                 return 0;
2717         }
2718
2719         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2720         if (tlink == NULL) {
2721                 /* can not match superblock if tlink were ever null */
2722                 spin_unlock(&cifs_tcp_ses_lock);
2723                 return 0;
2724         }
2725         tcon = tlink_tcon(tlink);
2726         ses = tcon->ses;
2727         tcp_srv = ses->server;
2728
2729         ctx = mnt_data->ctx;
2730
2731         spin_lock(&tcp_srv->srv_lock);
2732         spin_lock(&ses->ses_lock);
2733         spin_lock(&ses->chan_lock);
2734         spin_lock(&tcon->tc_lock);
2735         if (!match_server(tcp_srv, ctx) ||
2736             !match_session(ses, ctx) ||
2737             !match_tcon(tcon, ctx) ||
2738             !match_prepath(sb, tcp_srv, mnt_data)) {
2739                 rc = 0;
2740                 goto out;
2741         }
2742
2743         rc = compare_mount_options(sb, mnt_data);
2744 out:
2745         spin_unlock(&tcon->tc_lock);
2746         spin_unlock(&ses->chan_lock);
2747         spin_unlock(&ses->ses_lock);
2748         spin_unlock(&tcp_srv->srv_lock);
2749
2750         spin_unlock(&cifs_tcp_ses_lock);
2751         cifs_put_tlink(tlink);
2752         return rc;
2753 }
2754
2755 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2756 static struct lock_class_key cifs_key[2];
2757 static struct lock_class_key cifs_slock_key[2];
2758
2759 static inline void
2760 cifs_reclassify_socket4(struct socket *sock)
2761 {
2762         struct sock *sk = sock->sk;
2763         BUG_ON(!sock_allow_reclassification(sk));
2764         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2765                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2766 }
2767
2768 static inline void
2769 cifs_reclassify_socket6(struct socket *sock)
2770 {
2771         struct sock *sk = sock->sk;
2772         BUG_ON(!sock_allow_reclassification(sk));
2773         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2774                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2775 }
2776 #else
2777 static inline void
2778 cifs_reclassify_socket4(struct socket *sock)
2779 {
2780 }
2781
2782 static inline void
2783 cifs_reclassify_socket6(struct socket *sock)
2784 {
2785 }
2786 #endif
2787
2788 /* See RFC1001 section 14 on representation of Netbios names */
2789 static void rfc1002mangle(char *target, char *source, unsigned int length)
2790 {
2791         unsigned int i, j;
2792
2793         for (i = 0, j = 0; i < (length); i++) {
2794                 /* mask a nibble at a time and encode */
2795                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2796                 target[j+1] = 'A' + (0x0F & source[i]);
2797                 j += 2;
2798         }
2799
2800 }
2801
2802 static int
2803 bind_socket(struct TCP_Server_Info *server)
2804 {
2805         int rc = 0;
2806         if (server->srcaddr.ss_family != AF_UNSPEC) {
2807                 /* Bind to the specified local IP address */
2808                 struct socket *socket = server->ssocket;
2809                 rc = socket->ops->bind(socket,
2810                                        (struct sockaddr *) &server->srcaddr,
2811                                        sizeof(server->srcaddr));
2812                 if (rc < 0) {
2813                         struct sockaddr_in *saddr4;
2814                         struct sockaddr_in6 *saddr6;
2815                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2816                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2817                         if (saddr6->sin6_family == AF_INET6)
2818                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2819                                          &saddr6->sin6_addr, rc);
2820                         else
2821                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2822                                          &saddr4->sin_addr.s_addr, rc);
2823                 }
2824         }
2825         return rc;
2826 }
2827
2828 static int
2829 ip_rfc1001_connect(struct TCP_Server_Info *server)
2830 {
2831         int rc = 0;
2832         /*
2833          * some servers require RFC1001 sessinit before sending
2834          * negprot - BB check reconnection in case where second
2835          * sessinit is sent but no second negprot
2836          */
2837         struct rfc1002_session_packet req = {};
2838         struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
2839         unsigned int len;
2840
2841         req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
2842
2843         if (server->server_RFC1001_name[0] != 0)
2844                 rfc1002mangle(req.trailer.session_req.called_name,
2845                               server->server_RFC1001_name,
2846                               RFC1001_NAME_LEN_WITH_NULL);
2847         else
2848                 rfc1002mangle(req.trailer.session_req.called_name,
2849                               DEFAULT_CIFS_CALLED_NAME,
2850                               RFC1001_NAME_LEN_WITH_NULL);
2851
2852         req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name);
2853
2854         /* calling name ends in null (byte 16) from old smb convention */
2855         if (server->workstation_RFC1001_name[0] != 0)
2856                 rfc1002mangle(req.trailer.session_req.calling_name,
2857                               server->workstation_RFC1001_name,
2858                               RFC1001_NAME_LEN_WITH_NULL);
2859         else
2860                 rfc1002mangle(req.trailer.session_req.calling_name,
2861                               "LINUX_CIFS_CLNT",
2862                               RFC1001_NAME_LEN_WITH_NULL);
2863
2864         /*
2865          * As per rfc1002, @len must be the number of bytes that follows the
2866          * length field of a rfc1002 session request payload.
2867          */
2868         len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
2869
2870         smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
2871         rc = smb_send(server, smb_buf, len);
2872         /*
2873          * RFC1001 layer in at least one server requires very short break before
2874          * negprot presumably because not expecting negprot to follow so fast.
2875          * This is a simple solution that works without complicating the code
2876          * and causes no significant slowing down on mount for everyone else
2877          */
2878         usleep_range(1000, 2000);
2879
2880         return rc;
2881 }
2882
2883 static int
2884 generic_ip_connect(struct TCP_Server_Info *server)
2885 {
2886         int rc = 0;
2887         __be16 sport;
2888         int slen, sfamily;
2889         struct socket *socket = server->ssocket;
2890         struct sockaddr *saddr;
2891
2892         saddr = (struct sockaddr *) &server->dstaddr;
2893
2894         if (server->dstaddr.ss_family == AF_INET6) {
2895                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2896
2897                 sport = ipv6->sin6_port;
2898                 slen = sizeof(struct sockaddr_in6);
2899                 sfamily = AF_INET6;
2900                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2901                                 ntohs(sport));
2902         } else {
2903                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2904
2905                 sport = ipv4->sin_port;
2906                 slen = sizeof(struct sockaddr_in);
2907                 sfamily = AF_INET;
2908                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2909                                 ntohs(sport));
2910         }
2911
2912         if (socket == NULL) {
2913                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2914                                    IPPROTO_TCP, &socket, 1);
2915                 if (rc < 0) {
2916                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2917                         server->ssocket = NULL;
2918                         return rc;
2919                 }
2920
2921                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2922                 cifs_dbg(FYI, "Socket created\n");
2923                 server->ssocket = socket;
2924                 socket->sk->sk_allocation = GFP_NOFS;
2925                 socket->sk->sk_use_task_frag = false;
2926                 if (sfamily == AF_INET6)
2927                         cifs_reclassify_socket6(socket);
2928                 else
2929                         cifs_reclassify_socket4(socket);
2930         }
2931
2932         rc = bind_socket(server);
2933         if (rc < 0)
2934                 return rc;
2935
2936         /*
2937          * Eventually check for other socket options to change from
2938          * the default. sock_setsockopt not used because it expects
2939          * user space buffer
2940          */
2941         socket->sk->sk_rcvtimeo = 7 * HZ;
2942         socket->sk->sk_sndtimeo = 5 * HZ;
2943
2944         /* make the bufsizes depend on wsize/rsize and max requests */
2945         if (server->noautotune) {
2946                 if (socket->sk->sk_sndbuf < (200 * 1024))
2947                         socket->sk->sk_sndbuf = 200 * 1024;
2948                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2949                         socket->sk->sk_rcvbuf = 140 * 1024;
2950         }
2951
2952         if (server->tcp_nodelay)
2953                 tcp_sock_set_nodelay(socket->sk);
2954
2955         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2956                  socket->sk->sk_sndbuf,
2957                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2958
2959         rc = socket->ops->connect(socket, saddr, slen,
2960                                   server->noblockcnt ? O_NONBLOCK : 0);
2961         /*
2962          * When mounting SMB root file systems, we do not want to block in
2963          * connect. Otherwise bail out and then let cifs_reconnect() perform
2964          * reconnect failover - if possible.
2965          */
2966         if (server->noblockcnt && rc == -EINPROGRESS)
2967                 rc = 0;
2968         if (rc < 0) {
2969                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2970                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2971                 sock_release(socket);
2972                 server->ssocket = NULL;
2973                 return rc;
2974         }
2975         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2976         if (sport == htons(RFC1001_PORT))
2977                 rc = ip_rfc1001_connect(server);
2978
2979         return rc;
2980 }
2981
2982 static int
2983 ip_connect(struct TCP_Server_Info *server)
2984 {
2985         __be16 *sport;
2986         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2987         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2988
2989         if (server->dstaddr.ss_family == AF_INET6)
2990                 sport = &addr6->sin6_port;
2991         else
2992                 sport = &addr->sin_port;
2993
2994         if (*sport == 0) {
2995                 int rc;
2996
2997                 /* try with 445 port at first */
2998                 *sport = htons(CIFS_PORT);
2999
3000                 rc = generic_ip_connect(server);
3001                 if (rc >= 0)
3002                         return rc;
3003
3004                 /* if it failed, try with 139 port */
3005                 *sport = htons(RFC1001_PORT);
3006         }
3007
3008         return generic_ip_connect(server);
3009 }
3010
3011 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3012 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3013                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3014 {
3015         /*
3016          * If we are reconnecting then should we check to see if
3017          * any requested capabilities changed locally e.g. via
3018          * remount but we can not do much about it here
3019          * if they have (even if we could detect it by the following)
3020          * Perhaps we could add a backpointer to array of sb from tcon
3021          * or if we change to make all sb to same share the same
3022          * sb as NFS - then we only have one backpointer to sb.
3023          * What if we wanted to mount the server share twice once with
3024          * and once without posixacls or posix paths?
3025          */
3026         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3027
3028         if (ctx && ctx->no_linux_ext) {
3029                 tcon->fsUnixInfo.Capability = 0;
3030                 tcon->unix_ext = 0; /* Unix Extensions disabled */
3031                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3032                 return;
3033         } else if (ctx)
3034                 tcon->unix_ext = 1; /* Unix Extensions supported */
3035
3036         if (!tcon->unix_ext) {
3037                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3038                 return;
3039         }
3040
3041         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3042                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3043                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3044                 /*
3045                  * check for reconnect case in which we do not
3046                  * want to change the mount behavior if we can avoid it
3047                  */
3048                 if (ctx == NULL) {
3049                         /*
3050                          * turn off POSIX ACL and PATHNAMES if not set
3051                          * originally at mount time
3052                          */
3053                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3054                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3055                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3056                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3057                                         cifs_dbg(VFS, "POSIXPATH support change\n");
3058                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3059                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3060                                 cifs_dbg(VFS, "possible reconnect error\n");
3061                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
3062                         }
3063                 }
3064
3065                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3066                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
3067
3068                 cap &= CIFS_UNIX_CAP_MASK;
3069                 if (ctx && ctx->no_psx_acl)
3070                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3071                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3072                         cifs_dbg(FYI, "negotiated posix acl support\n");
3073                         if (cifs_sb)
3074                                 cifs_sb->mnt_cifs_flags |=
3075                                         CIFS_MOUNT_POSIXACL;
3076                 }
3077
3078                 if (ctx && ctx->posix_paths == 0)
3079                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3080                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3081                         cifs_dbg(FYI, "negotiate posix pathnames\n");
3082                         if (cifs_sb)
3083                                 cifs_sb->mnt_cifs_flags |=
3084                                         CIFS_MOUNT_POSIX_PATHS;
3085                 }
3086
3087                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3088 #ifdef CONFIG_CIFS_DEBUG2
3089                 if (cap & CIFS_UNIX_FCNTL_CAP)
3090                         cifs_dbg(FYI, "FCNTL cap\n");
3091                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3092                         cifs_dbg(FYI, "EXTATTR cap\n");
3093                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3094                         cifs_dbg(FYI, "POSIX path cap\n");
3095                 if (cap & CIFS_UNIX_XATTR_CAP)
3096                         cifs_dbg(FYI, "XATTR cap\n");
3097                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3098                         cifs_dbg(FYI, "POSIX ACL cap\n");
3099                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3100                         cifs_dbg(FYI, "very large read cap\n");
3101                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3102                         cifs_dbg(FYI, "very large write cap\n");
3103                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3104                         cifs_dbg(FYI, "transport encryption cap\n");
3105                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3106                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3107 #endif /* CIFS_DEBUG2 */
3108                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3109                         if (ctx == NULL)
3110                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3111                         else
3112                                 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");
3113
3114                 }
3115         }
3116 }
3117 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3118
3119 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3120 {
3121         struct smb3_fs_context *ctx = cifs_sb->ctx;
3122
3123         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3124
3125         spin_lock_init(&cifs_sb->tlink_tree_lock);
3126         cifs_sb->tlink_tree = RB_ROOT;
3127
3128         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3129                  ctx->file_mode, ctx->dir_mode);
3130
3131         /* this is needed for ASCII cp to Unicode converts */
3132         if (ctx->iocharset == NULL) {
3133                 /* load_nls_default cannot return null */
3134                 cifs_sb->local_nls = load_nls_default();
3135         } else {
3136                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3137                 if (cifs_sb->local_nls == NULL) {
3138                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3139                                  ctx->iocharset);
3140                         return -ELIBACC;
3141                 }
3142         }
3143         ctx->local_nls = cifs_sb->local_nls;
3144
3145         smb3_update_mnt_flags(cifs_sb);
3146
3147         if (ctx->direct_io)
3148                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3149         if (ctx->cache_ro) {
3150                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3151                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3152         } else if (ctx->cache_rw) {
3153                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3154                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3155                                             CIFS_MOUNT_RW_CACHE);
3156         }
3157
3158         if ((ctx->cifs_acl) && (ctx->dynperm))
3159                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3160
3161         if (ctx->prepath) {
3162                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3163                 if (cifs_sb->prepath == NULL)
3164                         return -ENOMEM;
3165                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3166         }
3167
3168         return 0;
3169 }
3170
3171 /* Release all succeed connections */
3172 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3173 {
3174         int rc = 0;
3175
3176         if (mnt_ctx->tcon)
3177                 cifs_put_tcon(mnt_ctx->tcon);
3178         else if (mnt_ctx->ses)
3179                 cifs_put_smb_ses(mnt_ctx->ses);
3180         else if (mnt_ctx->server)
3181                 cifs_put_tcp_session(mnt_ctx->server, 0);
3182         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3183         free_xid(mnt_ctx->xid);
3184 }
3185
3186 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3187 {
3188         struct TCP_Server_Info *server = NULL;
3189         struct smb3_fs_context *ctx;
3190         struct cifs_ses *ses = NULL;
3191         unsigned int xid;
3192         int rc = 0;
3193
3194         xid = get_xid();
3195
3196         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3197                 rc = -EINVAL;
3198                 goto out;
3199         }
3200         ctx = mnt_ctx->fs_ctx;
3201
3202         /* get a reference to a tcp session */
3203         server = cifs_get_tcp_session(ctx, NULL);
3204         if (IS_ERR(server)) {
3205                 rc = PTR_ERR(server);
3206                 server = NULL;
3207                 goto out;
3208         }
3209
3210         /* get a reference to a SMB session */
3211         ses = cifs_get_smb_ses(server, ctx);
3212         if (IS_ERR(ses)) {
3213                 rc = PTR_ERR(ses);
3214                 ses = NULL;
3215                 goto out;
3216         }
3217
3218         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3219                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3220                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3221                 rc = -EOPNOTSUPP;
3222         }
3223
3224 out:
3225         mnt_ctx->xid = xid;
3226         mnt_ctx->server = server;
3227         mnt_ctx->ses = ses;
3228         mnt_ctx->tcon = NULL;
3229
3230         return rc;
3231 }
3232
3233 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3234 {
3235         struct TCP_Server_Info *server;
3236         struct cifs_sb_info *cifs_sb;
3237         struct smb3_fs_context *ctx;
3238         struct cifs_tcon *tcon = NULL;
3239         int rc = 0;
3240
3241         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3242                          !mnt_ctx->cifs_sb)) {
3243                 rc = -EINVAL;
3244                 goto out;
3245         }
3246         server = mnt_ctx->server;
3247         ctx = mnt_ctx->fs_ctx;
3248         cifs_sb = mnt_ctx->cifs_sb;
3249
3250         /* search for existing tcon to this server share */
3251         tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3252         if (IS_ERR(tcon)) {
3253                 rc = PTR_ERR(tcon);
3254                 tcon = NULL;
3255                 goto out;
3256         }
3257
3258         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3259         if (tcon->posix_extensions)
3260                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3261
3262 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3263         /* tell server which Unix caps we support */
3264         if (cap_unix(tcon->ses)) {
3265                 /*
3266                  * reset of caps checks mount to see if unix extensions disabled
3267                  * for just this mount.
3268                  */
3269                 reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3270                 spin_lock(&tcon->ses->server->srv_lock);
3271                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3272                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3273                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3274                         spin_unlock(&tcon->ses->server->srv_lock);
3275                         rc = -EACCES;
3276                         goto out;
3277                 }
3278                 spin_unlock(&tcon->ses->server->srv_lock);
3279         } else
3280 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3281                 tcon->unix_ext = 0; /* server does not support them */
3282
3283         /* do not care if a following call succeed - informational */
3284         if (!tcon->pipe && server->ops->qfs_tcon) {
3285                 server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3286                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3287                         if (tcon->fsDevInfo.DeviceCharacteristics &
3288                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3289                                 cifs_dbg(VFS, "mounted to read only share\n");
3290                         else if ((cifs_sb->mnt_cifs_flags &
3291                                   CIFS_MOUNT_RW_CACHE) == 0)
3292                                 cifs_dbg(VFS, "read only mount of RW share\n");
3293                         /* no need to log a RW mount of a typical RW share */
3294                 }
3295         }
3296
3297         /*
3298          * Clamp the rsize/wsize mount arguments if they are too big for the server
3299          * and set the rsize/wsize to the negotiated values if not passed in by
3300          * the user on mount
3301          */
3302         if ((cifs_sb->ctx->wsize == 0) ||
3303             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3304                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3305         if ((cifs_sb->ctx->rsize == 0) ||
3306             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3307                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3308
3309         /*
3310          * The cookie is initialized from volume info returned above.
3311          * Inside cifs_fscache_get_super_cookie it checks
3312          * that we do not get super cookie twice.
3313          */
3314         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3315                 cifs_fscache_get_super_cookie(tcon);
3316
3317 out:
3318         mnt_ctx->tcon = tcon;
3319         return rc;
3320 }
3321
3322 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3323                              struct cifs_tcon *tcon)
3324 {
3325         struct tcon_link *tlink;
3326
3327         /* hang the tcon off of the superblock */
3328         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3329         if (tlink == NULL)
3330                 return -ENOMEM;
3331
3332         tlink->tl_uid = ses->linux_uid;
3333         tlink->tl_tcon = tcon;
3334         tlink->tl_time = jiffies;
3335         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3336         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3337
3338         cifs_sb->master_tlink = tlink;
3339         spin_lock(&cifs_sb->tlink_tree_lock);
3340         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3341         spin_unlock(&cifs_sb->tlink_tree_lock);
3342
3343         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3344                                 TLINK_IDLE_EXPIRE);
3345         return 0;
3346 }
3347
3348 static int
3349 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3350                                         unsigned int xid,
3351                                         struct cifs_tcon *tcon,
3352                                         struct cifs_sb_info *cifs_sb,
3353                                         char *full_path,
3354                                         int added_treename)
3355 {
3356         int rc;
3357         char *s;
3358         char sep, tmp;
3359         int skip = added_treename ? 1 : 0;
3360
3361         sep = CIFS_DIR_SEP(cifs_sb);
3362         s = full_path;
3363
3364         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3365         while (rc == 0) {
3366                 /* skip separators */
3367                 while (*s == sep)
3368                         s++;
3369                 if (!*s)
3370                         break;
3371                 /* next separator */
3372                 while (*s && *s != sep)
3373                         s++;
3374                 /*
3375                  * if the treename is added, we then have to skip the first
3376                  * part within the separators
3377                  */
3378                 if (skip) {
3379                         skip = 0;
3380                         continue;
3381                 }
3382                 /*
3383                  * temporarily null-terminate the path at the end of
3384                  * the current component
3385                  */
3386                 tmp = *s;
3387                 *s = 0;
3388                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3389                                                      full_path);
3390                 *s = tmp;
3391         }
3392         return rc;
3393 }
3394
3395 /*
3396  * Check if path is remote (i.e. a DFS share).
3397  *
3398  * Return -EREMOTE if it is, otherwise 0 or -errno.
3399  */
3400 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3401 {
3402         int rc;
3403         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3404         struct TCP_Server_Info *server = mnt_ctx->server;
3405         unsigned int xid = mnt_ctx->xid;
3406         struct cifs_tcon *tcon = mnt_ctx->tcon;
3407         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3408         char *full_path;
3409
3410         if (!server->ops->is_path_accessible)
3411                 return -EOPNOTSUPP;
3412
3413         /*
3414          * cifs_build_path_to_root works only when we have a valid tcon
3415          */
3416         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3417                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3418         if (full_path == NULL)
3419                 return -ENOMEM;
3420
3421         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3422
3423         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3424                                              full_path);
3425         if (rc != 0 && rc != -EREMOTE)
3426                 goto out;
3427
3428         if (rc != -EREMOTE) {
3429                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3430                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3431                 if (rc != 0) {
3432                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3433                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3434                         rc = 0;
3435                 }
3436         }
3437
3438 out:
3439         kfree(full_path);
3440         return rc;
3441 }
3442
3443 #ifdef CONFIG_CIFS_DFS_UPCALL
3444 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3445 {
3446         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3447         bool isdfs;
3448         int rc;
3449
3450         INIT_LIST_HEAD(&mnt_ctx.dfs_ses_list);
3451
3452         rc = dfs_mount_share(&mnt_ctx, &isdfs);
3453         if (rc)
3454                 goto error;
3455         if (!isdfs)
3456                 goto out;
3457
3458         /*
3459          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3460          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3461          */
3462         cifs_autodisable_serverino(cifs_sb);
3463         /*
3464          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3465          * that have different prefix paths.
3466          */
3467         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3468         kfree(cifs_sb->prepath);
3469         cifs_sb->prepath = ctx->prepath;
3470         ctx->prepath = NULL;
3471
3472 out:
3473         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3474         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3475         if (rc)
3476                 goto error;
3477
3478         free_xid(mnt_ctx.xid);
3479         return rc;
3480
3481 error:
3482         dfs_put_root_smb_sessions(&mnt_ctx.dfs_ses_list);
3483         cifs_mount_put_conns(&mnt_ctx);
3484         return rc;
3485 }
3486 #else
3487 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3488 {
3489         int rc = 0;
3490         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3491
3492         rc = cifs_mount_get_session(&mnt_ctx);
3493         if (rc)
3494                 goto error;
3495
3496         rc = cifs_mount_get_tcon(&mnt_ctx);
3497         if (rc)
3498                 goto error;
3499
3500         rc = cifs_is_path_remote(&mnt_ctx);
3501         if (rc == -EREMOTE)
3502                 rc = -EOPNOTSUPP;
3503         if (rc)
3504                 goto error;
3505
3506         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3507         if (rc)
3508                 goto error;
3509
3510         free_xid(mnt_ctx.xid);
3511         return rc;
3512
3513 error:
3514         cifs_mount_put_conns(&mnt_ctx);
3515         return rc;
3516 }
3517 #endif
3518
3519 /*
3520  * Issue a TREE_CONNECT request.
3521  */
3522 int
3523 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3524          const char *tree, struct cifs_tcon *tcon,
3525          const struct nls_table *nls_codepage)
3526 {
3527         struct smb_hdr *smb_buffer;
3528         struct smb_hdr *smb_buffer_response;
3529         TCONX_REQ *pSMB;
3530         TCONX_RSP *pSMBr;
3531         unsigned char *bcc_ptr;
3532         int rc = 0;
3533         int length;
3534         __u16 bytes_left, count;
3535
3536         if (ses == NULL)
3537                 return -EIO;
3538
3539         smb_buffer = cifs_buf_get();
3540         if (smb_buffer == NULL)
3541                 return -ENOMEM;
3542
3543         smb_buffer_response = smb_buffer;
3544
3545         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3546                         NULL /*no tid */ , 4 /*wct */ );
3547
3548         smb_buffer->Mid = get_next_mid(ses->server);
3549         smb_buffer->Uid = ses->Suid;
3550         pSMB = (TCONX_REQ *) smb_buffer;
3551         pSMBr = (TCONX_RSP *) smb_buffer_response;
3552
3553         pSMB->AndXCommand = 0xFF;
3554         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3555         bcc_ptr = &pSMB->Password[0];
3556
3557         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3558         *bcc_ptr = 0; /* password is null byte */
3559         bcc_ptr++;              /* skip password */
3560         /* already aligned so no need to do it below */
3561
3562         if (ses->server->sign)
3563                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3564
3565         if (ses->capabilities & CAP_STATUS32) {
3566                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3567         }
3568         if (ses->capabilities & CAP_DFS) {
3569                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3570         }
3571         if (ses->capabilities & CAP_UNICODE) {
3572                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3573                 length =
3574                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3575                         6 /* max utf8 char length in bytes */ *
3576                         (/* server len*/ + 256 /* share len */), nls_codepage);
3577                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3578                 bcc_ptr += 2;   /* skip trailing null */
3579         } else {                /* ASCII */
3580                 strcpy(bcc_ptr, tree);
3581                 bcc_ptr += strlen(tree) + 1;
3582         }
3583         strcpy(bcc_ptr, "?????");
3584         bcc_ptr += strlen("?????");
3585         bcc_ptr += 1;
3586         count = bcc_ptr - &pSMB->Password[0];
3587         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3588         pSMB->ByteCount = cpu_to_le16(count);
3589
3590         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3591                          0);
3592
3593         /* above now done in SendReceive */
3594         if (rc == 0) {
3595                 bool is_unicode;
3596
3597                 tcon->tid = smb_buffer_response->Tid;
3598                 bcc_ptr = pByteArea(smb_buffer_response);
3599                 bytes_left = get_bcc(smb_buffer_response);
3600                 length = strnlen(bcc_ptr, bytes_left - 2);
3601                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3602                         is_unicode = true;
3603                 else
3604                         is_unicode = false;
3605
3606
3607                 /* skip service field (NB: this field is always ASCII) */
3608                 if (length == 3) {
3609                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3610                             (bcc_ptr[2] == 'C')) {
3611                                 cifs_dbg(FYI, "IPC connection\n");
3612                                 tcon->ipc = true;
3613                                 tcon->pipe = true;
3614                         }
3615                 } else if (length == 2) {
3616                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3617                                 /* the most common case */
3618                                 cifs_dbg(FYI, "disk share connection\n");
3619                         }
3620                 }
3621                 bcc_ptr += length + 1;
3622                 bytes_left -= (length + 1);
3623                 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3624
3625                 /* mostly informational -- no need to fail on error here */
3626                 kfree(tcon->nativeFileSystem);
3627                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3628                                                       bytes_left, is_unicode,
3629                                                       nls_codepage);
3630
3631                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3632
3633                 if ((smb_buffer_response->WordCount == 3) ||
3634                          (smb_buffer_response->WordCount == 7))
3635                         /* field is in same location */
3636                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3637                 else
3638                         tcon->Flags = 0;
3639                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3640         }
3641
3642         cifs_buf_release(smb_buffer);
3643         return rc;
3644 }
3645
3646 static void delayed_free(struct rcu_head *p)
3647 {
3648         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3649
3650         unload_nls(cifs_sb->local_nls);
3651         smb3_cleanup_fs_context(cifs_sb->ctx);
3652         kfree(cifs_sb);
3653 }
3654
3655 void
3656 cifs_umount(struct cifs_sb_info *cifs_sb)
3657 {
3658         struct rb_root *root = &cifs_sb->tlink_tree;
3659         struct rb_node *node;
3660         struct tcon_link *tlink;
3661
3662         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3663
3664         spin_lock(&cifs_sb->tlink_tree_lock);
3665         while ((node = rb_first(root))) {
3666                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3667                 cifs_get_tlink(tlink);
3668                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3669                 rb_erase(node, root);
3670
3671                 spin_unlock(&cifs_sb->tlink_tree_lock);
3672                 cifs_put_tlink(tlink);
3673                 spin_lock(&cifs_sb->tlink_tree_lock);
3674         }
3675         spin_unlock(&cifs_sb->tlink_tree_lock);
3676
3677         kfree(cifs_sb->prepath);
3678         call_rcu(&cifs_sb->rcu, delayed_free);
3679 }
3680
3681 int
3682 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3683                         struct TCP_Server_Info *server)
3684 {
3685         int rc = 0;
3686
3687         if (!server->ops->need_neg || !server->ops->negotiate)
3688                 return -ENOSYS;
3689
3690         /* only send once per connect */
3691         spin_lock(&server->srv_lock);
3692         if (server->tcpStatus != CifsGood &&
3693             server->tcpStatus != CifsNew &&
3694             server->tcpStatus != CifsNeedNegotiate) {
3695                 spin_unlock(&server->srv_lock);
3696                 return -EHOSTDOWN;
3697         }
3698
3699         if (!server->ops->need_neg(server) &&
3700             server->tcpStatus == CifsGood) {
3701                 spin_unlock(&server->srv_lock);
3702                 return 0;
3703         }
3704
3705         server->tcpStatus = CifsInNegotiate;
3706         spin_unlock(&server->srv_lock);
3707
3708         rc = server->ops->negotiate(xid, ses, server);
3709         if (rc == 0) {
3710                 spin_lock(&server->srv_lock);
3711                 if (server->tcpStatus == CifsInNegotiate)
3712                         server->tcpStatus = CifsGood;
3713                 else
3714                         rc = -EHOSTDOWN;
3715                 spin_unlock(&server->srv_lock);
3716         } else {
3717                 spin_lock(&server->srv_lock);
3718                 if (server->tcpStatus == CifsInNegotiate)
3719                         server->tcpStatus = CifsNeedNegotiate;
3720                 spin_unlock(&server->srv_lock);
3721         }
3722
3723         return rc;
3724 }
3725
3726 int
3727 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3728                    struct TCP_Server_Info *server,
3729                    struct nls_table *nls_info)
3730 {
3731         int rc = -ENOSYS;
3732         struct TCP_Server_Info *pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
3733         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
3734         struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
3735         bool is_binding = false;
3736
3737         spin_lock(&ses->ses_lock);
3738         cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
3739                  __func__, ses->chans_need_reconnect);
3740
3741         if (ses->ses_status != SES_GOOD &&
3742             ses->ses_status != SES_NEW &&
3743             ses->ses_status != SES_NEED_RECON) {
3744                 spin_unlock(&ses->ses_lock);
3745                 return -EHOSTDOWN;
3746         }
3747
3748         /* only send once per connect */
3749         spin_lock(&ses->chan_lock);
3750         if (CIFS_ALL_CHANS_GOOD(ses)) {
3751                 if (ses->ses_status == SES_NEED_RECON)
3752                         ses->ses_status = SES_GOOD;
3753                 spin_unlock(&ses->chan_lock);
3754                 spin_unlock(&ses->ses_lock);
3755                 return 0;
3756         }
3757
3758         cifs_chan_set_in_reconnect(ses, server);
3759         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3760         spin_unlock(&ses->chan_lock);
3761
3762         if (!is_binding)
3763                 ses->ses_status = SES_IN_SETUP;
3764         spin_unlock(&ses->ses_lock);
3765
3766         /* update ses ip_addr only for primary chan */
3767         if (server == pserver) {
3768                 if (server->dstaddr.ss_family == AF_INET6)
3769                         scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3770                 else
3771                         scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3772         }
3773
3774         if (!is_binding) {
3775                 ses->capabilities = server->capabilities;
3776                 if (!linuxExtEnabled)
3777                         ses->capabilities &= (~server->vals->cap_unix);
3778
3779                 if (ses->auth_key.response) {
3780                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3781                                  ses->auth_key.response);
3782                         kfree_sensitive(ses->auth_key.response);
3783                         ses->auth_key.response = NULL;
3784                         ses->auth_key.len = 0;
3785                 }
3786         }
3787
3788         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3789                  server->sec_mode, server->capabilities, server->timeAdj);
3790
3791         if (server->ops->sess_setup)
3792                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
3793
3794         if (rc) {
3795                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3796                 spin_lock(&ses->ses_lock);
3797                 if (ses->ses_status == SES_IN_SETUP)
3798                         ses->ses_status = SES_NEED_RECON;
3799                 spin_lock(&ses->chan_lock);
3800                 cifs_chan_clear_in_reconnect(ses, server);
3801                 spin_unlock(&ses->chan_lock);
3802                 spin_unlock(&ses->ses_lock);
3803         } else {
3804                 spin_lock(&ses->ses_lock);
3805                 if (ses->ses_status == SES_IN_SETUP)
3806                         ses->ses_status = SES_GOOD;
3807                 spin_lock(&ses->chan_lock);
3808                 cifs_chan_clear_in_reconnect(ses, server);
3809                 cifs_chan_clear_need_reconnect(ses, server);
3810                 spin_unlock(&ses->chan_lock);
3811                 spin_unlock(&ses->ses_lock);
3812         }
3813
3814         return rc;
3815 }
3816
3817 static int
3818 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3819 {
3820         ctx->sectype = ses->sectype;
3821
3822         /* krb5 is special, since we don't need username or pw */
3823         if (ctx->sectype == Kerberos)
3824                 return 0;
3825
3826         return cifs_set_cifscreds(ctx, ses);
3827 }
3828
3829 static struct cifs_tcon *
3830 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3831 {
3832         int rc;
3833         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3834         struct cifs_ses *ses;
3835         struct cifs_tcon *tcon = NULL;
3836         struct smb3_fs_context *ctx;
3837
3838         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3839         if (ctx == NULL)
3840                 return ERR_PTR(-ENOMEM);
3841
3842         ctx->local_nls = cifs_sb->local_nls;
3843         ctx->linux_uid = fsuid;
3844         ctx->cred_uid = fsuid;
3845         ctx->UNC = master_tcon->tree_name;
3846         ctx->retry = master_tcon->retry;
3847         ctx->nocase = master_tcon->nocase;
3848         ctx->nohandlecache = master_tcon->nohandlecache;
3849         ctx->local_lease = master_tcon->local_lease;
3850         ctx->no_lease = master_tcon->no_lease;
3851         ctx->resilient = master_tcon->use_resilient;
3852         ctx->persistent = master_tcon->use_persistent;
3853         ctx->handle_timeout = master_tcon->handle_timeout;
3854         ctx->no_linux_ext = !master_tcon->unix_ext;
3855         ctx->linux_ext = master_tcon->posix_extensions;
3856         ctx->sectype = master_tcon->ses->sectype;
3857         ctx->sign = master_tcon->ses->sign;
3858         ctx->seal = master_tcon->seal;
3859         ctx->witness = master_tcon->use_witness;
3860
3861         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3862         if (rc) {
3863                 tcon = ERR_PTR(rc);
3864                 goto out;
3865         }
3866
3867         /* get a reference for the same TCP session */
3868         spin_lock(&cifs_tcp_ses_lock);
3869         ++master_tcon->ses->server->srv_count;
3870         spin_unlock(&cifs_tcp_ses_lock);
3871
3872         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3873         if (IS_ERR(ses)) {
3874                 tcon = (struct cifs_tcon *)ses;
3875                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3876                 goto out;
3877         }
3878
3879         tcon = cifs_get_tcon(ses, ctx);
3880         if (IS_ERR(tcon)) {
3881                 cifs_put_smb_ses(ses);
3882                 goto out;
3883         }
3884
3885 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3886         if (cap_unix(ses))
3887                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3888 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3889
3890 out:
3891         kfree(ctx->username);
3892         kfree_sensitive(ctx->password);
3893         kfree(ctx);
3894
3895         return tcon;
3896 }
3897
3898 struct cifs_tcon *
3899 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3900 {
3901         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3902 }
3903
3904 /* find and return a tlink with given uid */
3905 static struct tcon_link *
3906 tlink_rb_search(struct rb_root *root, kuid_t uid)
3907 {
3908         struct rb_node *node = root->rb_node;
3909         struct tcon_link *tlink;
3910
3911         while (node) {
3912                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3913
3914                 if (uid_gt(tlink->tl_uid, uid))
3915                         node = node->rb_left;
3916                 else if (uid_lt(tlink->tl_uid, uid))
3917                         node = node->rb_right;
3918                 else
3919                         return tlink;
3920         }
3921         return NULL;
3922 }
3923
3924 /* insert a tcon_link into the tree */
3925 static void
3926 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3927 {
3928         struct rb_node **new = &(root->rb_node), *parent = NULL;
3929         struct tcon_link *tlink;
3930
3931         while (*new) {
3932                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3933                 parent = *new;
3934
3935                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3936                         new = &((*new)->rb_left);
3937                 else
3938                         new = &((*new)->rb_right);
3939         }
3940
3941         rb_link_node(&new_tlink->tl_rbnode, parent, new);
3942         rb_insert_color(&new_tlink->tl_rbnode, root);
3943 }
3944
3945 /*
3946  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3947  * current task.
3948  *
3949  * If the superblock doesn't refer to a multiuser mount, then just return
3950  * the master tcon for the mount.
3951  *
3952  * First, search the rbtree for an existing tcon for this fsuid. If one
3953  * exists, then check to see if it's pending construction. If it is then wait
3954  * for construction to complete. Once it's no longer pending, check to see if
3955  * it failed and either return an error or retry construction, depending on
3956  * the timeout.
3957  *
3958  * If one doesn't exist then insert a new tcon_link struct into the tree and
3959  * try to construct a new one.
3960  */
3961 struct tcon_link *
3962 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3963 {
3964         int ret;
3965         kuid_t fsuid = current_fsuid();
3966         struct tcon_link *tlink, *newtlink;
3967
3968         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3969                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3970
3971         spin_lock(&cifs_sb->tlink_tree_lock);
3972         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3973         if (tlink)
3974                 cifs_get_tlink(tlink);
3975         spin_unlock(&cifs_sb->tlink_tree_lock);
3976
3977         if (tlink == NULL) {
3978                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3979                 if (newtlink == NULL)
3980                         return ERR_PTR(-ENOMEM);
3981                 newtlink->tl_uid = fsuid;
3982                 newtlink->tl_tcon = ERR_PTR(-EACCES);
3983                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
3984                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
3985                 cifs_get_tlink(newtlink);
3986
3987                 spin_lock(&cifs_sb->tlink_tree_lock);
3988                 /* was one inserted after previous search? */
3989                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3990                 if (tlink) {
3991                         cifs_get_tlink(tlink);
3992                         spin_unlock(&cifs_sb->tlink_tree_lock);
3993                         kfree(newtlink);
3994                         goto wait_for_construction;
3995                 }
3996                 tlink = newtlink;
3997                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3998                 spin_unlock(&cifs_sb->tlink_tree_lock);
3999         } else {
4000 wait_for_construction:
4001                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4002                                   TASK_INTERRUPTIBLE);
4003                 if (ret) {
4004                         cifs_put_tlink(tlink);
4005                         return ERR_PTR(-ERESTARTSYS);
4006                 }
4007
4008                 /* if it's good, return it */
4009                 if (!IS_ERR(tlink->tl_tcon))
4010                         return tlink;
4011
4012                 /* return error if we tried this already recently */
4013                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4014                         cifs_put_tlink(tlink);
4015                         return ERR_PTR(-EACCES);
4016                 }
4017
4018                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4019                         goto wait_for_construction;
4020         }
4021
4022         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4023         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4024         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4025
4026         if (IS_ERR(tlink->tl_tcon)) {
4027                 cifs_put_tlink(tlink);
4028                 return ERR_PTR(-EACCES);
4029         }
4030
4031         return tlink;
4032 }
4033
4034 /*
4035  * periodic workqueue job that scans tcon_tree for a superblock and closes
4036  * out tcons.
4037  */
4038 static void
4039 cifs_prune_tlinks(struct work_struct *work)
4040 {
4041         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4042                                                     prune_tlinks.work);
4043         struct rb_root *root = &cifs_sb->tlink_tree;
4044         struct rb_node *node;
4045         struct rb_node *tmp;
4046         struct tcon_link *tlink;
4047
4048         /*
4049          * Because we drop the spinlock in the loop in order to put the tlink
4050          * it's not guarded against removal of links from the tree. The only
4051          * places that remove entries from the tree are this function and
4052          * umounts. Because this function is non-reentrant and is canceled
4053          * before umount can proceed, this is safe.
4054          */
4055         spin_lock(&cifs_sb->tlink_tree_lock);
4056         node = rb_first(root);
4057         while (node != NULL) {
4058                 tmp = node;
4059                 node = rb_next(tmp);
4060                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4061
4062                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4063                     atomic_read(&tlink->tl_count) != 0 ||
4064                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4065                         continue;
4066
4067                 cifs_get_tlink(tlink);
4068                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4069                 rb_erase(tmp, root);
4070
4071                 spin_unlock(&cifs_sb->tlink_tree_lock);
4072                 cifs_put_tlink(tlink);
4073                 spin_lock(&cifs_sb->tlink_tree_lock);
4074         }
4075         spin_unlock(&cifs_sb->tlink_tree_lock);
4076
4077         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4078                                 TLINK_IDLE_EXPIRE);
4079 }
4080
4081 #ifndef CONFIG_CIFS_DFS_UPCALL
4082 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4083 {
4084         int rc;
4085         const struct smb_version_operations *ops = tcon->ses->server->ops;
4086
4087         /* only send once per connect */
4088         spin_lock(&tcon->tc_lock);
4089         if (tcon->status != TID_NEW &&
4090             tcon->status != TID_NEED_TCON) {
4091                 spin_unlock(&tcon->tc_lock);
4092                 return -EHOSTDOWN;
4093         }
4094
4095         if (tcon->status == TID_GOOD) {
4096                 spin_unlock(&tcon->tc_lock);
4097                 return 0;
4098         }
4099         tcon->status = TID_IN_TCON;
4100         spin_unlock(&tcon->tc_lock);
4101
4102         rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4103         if (rc) {
4104                 spin_lock(&tcon->tc_lock);
4105                 if (tcon->status == TID_IN_TCON)
4106                         tcon->status = TID_NEED_TCON;
4107                 spin_unlock(&tcon->tc_lock);
4108         } else {
4109                 spin_lock(&tcon->tc_lock);
4110                 if (tcon->status == TID_IN_TCON)
4111                         tcon->status = TID_GOOD;
4112                 tcon->need_reconnect = false;
4113                 spin_unlock(&tcon->tc_lock);
4114         }
4115
4116         return rc;
4117 }
4118 #endif