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         time64_t expiry, now;
  83         unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  84
  85         if (!server->hostname)
  86                 return -EINVAL;
  87
  88         /* if server hostname isn't populated, there's nothing to do here */
  89         if (server->hostname[0] == '\0')
  90                 return 0;
  91
  92         len = strlen(server->hostname) + 3;
  93
  94         unc = kmalloc(len, GFP_KERNEL);
  95         if (!unc) {
  96                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
  97                 return -ENOMEM;
  98         }
  99         scnprintf(unc, len, "\\\\%s", server->hostname);
 100
 101         spin_lock(&server->srv_lock);
 102         ss = server->dstaddr;
 103         spin_unlock(&server->srv_lock);
 104
 105         rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, &expiry);
 106         kfree(unc);
 107
 108         if (rc < 0) {
 109                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 110                          __func__, server->hostname, rc);
 111                 goto requeue_resolve;
 112         }
 113
 114         spin_lock(&server->srv_lock);
 115         memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 116         spin_unlock(&server->srv_lock);
 117
 118         now = ktime_get_real_seconds();
 119         if (expiry && expiry > now)
 120                 /* To make sure we don't use the cached entry, retry 1s */
 121                 ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 122
 123 requeue_resolve:
 124         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 125                  __func__, ttl);
 126         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 127
 128         return rc;
 129 }
 130
 131 static void smb2_query_server_interfaces(struct work_struct *work)
 132 {
 133         int rc;
 134         struct cifs_tcon *tcon = container_of(work,
 135                                         struct cifs_tcon,
 136                                         query_interfaces.work);
 137
 138         /*
 139          * query server network interfaces, in case they change
 140          */
 141         rc = SMB3_request_interfaces(0, tcon, false);
 142         if (rc) {
 143                 cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 144                                 __func__, rc);
 145         }
 146
 147         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 148                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
 149 }
 150
 151 static void cifs_resolve_server(struct work_struct *work)
 152 {
 153         int rc;
 154         struct TCP_Server_Info *server = container_of(work,
 155                                         struct TCP_Server_Info, resolve.work);
 156
 157         cifs_server_lock(server);
 158
 159         /*
 160          * Resolve the hostname again to make sure that IP address is up-to-date.
 161          */
 162         rc = reconn_set_ipaddr_from_hostname(server);
 163         if (rc) {
 164                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 165                                 __func__, rc);
 166         }
 167
 168         cifs_server_unlock(server);
 169 }
 170
 171 /*
 172  * Update the tcpStatus for the server.
 173  * This is used to signal the cifsd thread to call cifs_reconnect
 174  * ONLY cifsd thread should call cifs_reconnect. For any other
 175  * thread, use this function
 176  *
 177  * @server: the tcp ses for which reconnect is needed
 178  * @all_channels: if this needs to be done for all channels
 179  */
 180 void
 181 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 182                                 bool all_channels)
 183 {
 184         struct TCP_Server_Info *pserver;
 185         struct cifs_ses *ses;
 186         int i;
 187
 188         /* If server is a channel, select the primary channel */
 189         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 190
 191         spin_lock(&pserver->srv_lock);
 192         if (!all_channels) {
 193                 pserver->tcpStatus = CifsNeedReconnect;
 194                 spin_unlock(&pserver->srv_lock);
 195                 return;
 196         }
 197         spin_unlock(&pserver->srv_lock);
 198
 199         spin_lock(&cifs_tcp_ses_lock);
 200         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 201                 spin_lock(&ses->chan_lock);
 202                 for (i = 0; i < ses->chan_count; i++) {
 203                         spin_lock(&ses->chans[i].server->srv_lock);
 204                         ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 205                         spin_unlock(&ses->chans[i].server->srv_lock);
 206                 }
 207                 spin_unlock(&ses->chan_lock);
 208         }
 209         spin_unlock(&cifs_tcp_ses_lock);
 210 }
 211
 212 /*
 213  * Mark all sessions and tcons for reconnect.
 214  * IMPORTANT: make sure that this gets called only from
 215  * cifsd thread. For any other thread, use
 216  * cifs_signal_cifsd_for_reconnect
 217  *
 218  * @server: the tcp ses for which reconnect is needed
 219  * @server needs to be previously set to CifsNeedReconnect.
 220  * @mark_smb_session: whether even sessions need to be marked
 221  */
 222 void
 223 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 224                                       bool mark_smb_session)
 225 {
 226         struct TCP_Server_Info *pserver;
 227         struct cifs_ses *ses, *nses;
 228         struct cifs_tcon *tcon;
 229
 230         /*
 231          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 232          * are not used until reconnected.
 233          */
 234         cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 235
 236         /* If server is a channel, select the primary channel */
 237         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 238
 239
 240         spin_lock(&cifs_tcp_ses_lock);
 241         list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 242                 /* check if iface is still active */
 243                 if (!cifs_chan_is_iface_active(ses, server))
 244                         cifs_chan_update_iface(ses, server);
 245
 246                 spin_lock(&ses->chan_lock);
 247                 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
 248                         goto next_session;
 249
 250                 if (mark_smb_session)
 251                         CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 252                 else
 253                         cifs_chan_set_need_reconnect(ses, server);
 254
 255                 /* If all channels need reconnect, then tcon needs reconnect */
 256                 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
 257                         goto next_session;
 258
 259                 ses->ses_status = SES_NEED_RECON;
 260
 261                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 262                         tcon->need_reconnect = true;
 263                         tcon->status = TID_NEED_RECON;
 264                 }
 265                 if (ses->tcon_ipc)
 266                         ses->tcon_ipc->need_reconnect = true;
 267
 268 next_session:
 269                 spin_unlock(&ses->chan_lock);
 270         }
 271         spin_unlock(&cifs_tcp_ses_lock);
 272 }
 273
 274 static void
 275 cifs_abort_connection(struct TCP_Server_Info *server)
 276 {
 277         struct mid_q_entry *mid, *nmid;
 278         struct list_head retry_list;
 279
 280         server->maxBuf = 0;
 281         server->max_read = 0;
 282
 283         /* do not want to be sending data on a socket we are freeing */
 284         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 285         cifs_server_lock(server);
 286         if (server->ssocket) {
 287                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 288                          server->ssocket->flags);
 289                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 290                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 291                          server->ssocket->flags);
 292                 sock_release(server->ssocket);
 293                 server->ssocket = NULL;
 294         }
 295         server->sequence_number = 0;
 296         server->session_estab = false;
 297         kfree_sensitive(server->session_key.response);
 298         server->session_key.response = NULL;
 299         server->session_key.len = 0;
 300         server->lstrp = jiffies;
 301
 302         /* mark submitted MIDs for retry and issue callback */
 303         INIT_LIST_HEAD(&retry_list);
 304         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 305         spin_lock(&server->mid_lock);
 306         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 307                 kref_get(&mid->refcount);
 308                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 309                         mid->mid_state = MID_RETRY_NEEDED;
 310                 list_move(&mid->qhead, &retry_list);
 311                 mid->mid_flags |= MID_DELETED;
 312         }
 313         spin_unlock(&server->mid_lock);
 314         cifs_server_unlock(server);
 315
 316         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 317         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 318                 list_del_init(&mid->qhead);
 319                 mid->callback(mid);
 320                 release_mid(mid);
 321         }
 322
 323         if (cifs_rdma_enabled(server)) {
 324                 cifs_server_lock(server);
 325                 smbd_destroy(server);
 326                 cifs_server_unlock(server);
 327         }
 328 }
 329
 330 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 331 {
 332         spin_lock(&server->srv_lock);
 333         server->nr_targets = num_targets;
 334         if (server->tcpStatus == CifsExiting) {
 335                 /* the demux thread will exit normally next time through the loop */
 336                 spin_unlock(&server->srv_lock);
 337                 wake_up(&server->response_q);
 338                 return false;
 339         }
 340
 341         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 342         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 343                              server->hostname);
 344         server->tcpStatus = CifsNeedReconnect;
 345
 346         spin_unlock(&server->srv_lock);
 347         return true;
 348 }
 349
 350 /*
 351  * cifs tcp session reconnection
 352  *
 353  * mark tcp session as reconnecting so temporarily locked
 354  * mark all smb sessions as reconnecting for tcp session
 355  * reconnect tcp session
 356  * wake up waiters on reconnection? - (not needed currently)
 357  *
 358  * if mark_smb_session is passed as true, unconditionally mark
 359  * the smb session (and tcon) for reconnect as well. This value
 360  * doesn't really matter for non-multichannel scenario.
 361  *
 362  */
 363 static int __cifs_reconnect(struct TCP_Server_Info *server,
 364                             bool mark_smb_session)
 365 {
 366         int rc = 0;
 367
 368         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 369                 return 0;
 370
 371         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 372
 373         cifs_abort_connection(server);
 374
 375         do {
 376                 try_to_freeze();
 377                 cifs_server_lock(server);
 378
 379                 if (!cifs_swn_set_server_dstaddr(server)) {
 380                         /* resolve the hostname again to make sure that IP address is up-to-date */
 381                         rc = reconn_set_ipaddr_from_hostname(server);
 382                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 383                 }
 384
 385                 if (cifs_rdma_enabled(server))
 386                         rc = smbd_reconnect(server);
 387                 else
 388                         rc = generic_ip_connect(server);
 389                 if (rc) {
 390                         cifs_server_unlock(server);
 391                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 392                         msleep(3000);
 393                 } else {
 394                         atomic_inc(&tcpSesReconnectCount);
 395                         set_credits(server, 1);
 396                         spin_lock(&server->srv_lock);
 397                         if (server->tcpStatus != CifsExiting)
 398                                 server->tcpStatus = CifsNeedNegotiate;
 399                         spin_unlock(&server->srv_lock);
 400                         cifs_swn_reset_server_dstaddr(server);
 401                         cifs_server_unlock(server);
 402                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 403                 }
 404         } while (server->tcpStatus == CifsNeedReconnect);
 405
 406         spin_lock(&server->srv_lock);
 407         if (server->tcpStatus == CifsNeedNegotiate)
 408                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 409         spin_unlock(&server->srv_lock);
 410
 411         wake_up(&server->response_q);
 412         return rc;
 413 }
 414
 415 #ifdef CONFIG_CIFS_DFS_UPCALL
 416 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 417 {
 418         int rc;
 419         char *hostname;
 420
 421         if (!cifs_swn_set_server_dstaddr(server)) {
 422                 if (server->hostname != target) {
 423                         hostname = extract_hostname(target);
 424                         if (!IS_ERR(hostname)) {
 425                                 kfree(server->hostname);
 426                                 server->hostname = hostname;
 427                         } else {
 428                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 429                                          __func__, PTR_ERR(hostname));
 430                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 431                                          server->hostname);
 432                         }
 433                 }
 434                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 435                 rc = reconn_set_ipaddr_from_hostname(server);
 436                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 437         }
 438         /* Reconnect the socket */
 439         if (cifs_rdma_enabled(server))
 440                 rc = smbd_reconnect(server);
 441         else
 442                 rc = generic_ip_connect(server);
 443
 444         return rc;
 445 }
 446
 447 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 448                                      struct dfs_cache_tgt_iterator **target_hint)
 449 {
 450         int rc;
 451         struct dfs_cache_tgt_iterator *tit;
 452
 453         *target_hint = NULL;
 454
 455         /* If dfs target list is empty, then reconnect to last server */
 456         tit = dfs_cache_get_tgt_iterator(tl);
 457         if (!tit)
 458                 return __reconnect_target_unlocked(server, server->hostname);
 459
 460         /* Otherwise, try every dfs target in @tl */
 461         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 462                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 463                 if (!rc) {
 464                         *target_hint = tit;
 465                         break;
 466                 }
 467         }
 468         return rc;
 469 }
 470
 471 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 472 {
 473         int rc = 0;
 474         const char *refpath = server->current_fullpath + 1;
 475         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 476         struct dfs_cache_tgt_iterator *target_hint = NULL;
 477         int num_targets = 0;
 478
 479         /*
 480          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 481          *
 482          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 483          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 484          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 485          * refreshing the referral, so, in this case, default it to 1.
 486          */
 487         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 488                 num_targets = dfs_cache_get_nr_tgts(&tl);
 489         if (!num_targets)
 490                 num_targets = 1;
 491
 492         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 493                 return 0;
 494
 495         /*
 496          * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 497          * different server or share during failover.  It could be improved by adding some logic to
 498          * only do that in case it connects to a different server or share, though.
 499          */
 500         cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 501
 502         cifs_abort_connection(server);
 503
 504         do {
 505                 try_to_freeze();
 506                 cifs_server_lock(server);
 507
 508                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 509                 if (rc) {
 510                         /* Failed to reconnect socket */
 511                         cifs_server_unlock(server);
 512                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 513                         msleep(3000);
 514                         continue;
 515                 }
 516                 /*
 517                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 518                  * process waiting for reconnect will know it needs to re-establish session and tcon
 519                  * through the reconnected target server.
 520                  */
 521                 atomic_inc(&tcpSesReconnectCount);
 522                 set_credits(server, 1);
 523                 spin_lock(&server->srv_lock);
 524                 if (server->tcpStatus != CifsExiting)
 525                         server->tcpStatus = CifsNeedNegotiate;
 526                 spin_unlock(&server->srv_lock);
 527                 cifs_swn_reset_server_dstaddr(server);
 528                 cifs_server_unlock(server);
 529                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 530         } while (server->tcpStatus == CifsNeedReconnect);
 531
 532         if (target_hint)
 533                 dfs_cache_noreq_update_tgthint(refpath, target_hint);
 534
 535         dfs_cache_free_tgts(&tl);
 536
 537         /* Need to set up echo worker again once connection has been established */
 538         spin_lock(&server->srv_lock);
 539         if (server->tcpStatus == CifsNeedNegotiate)
 540                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 541         spin_unlock(&server->srv_lock);
 542
 543         wake_up(&server->response_q);
 544         return rc;
 545 }
 546
 547 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 548 {
 549         mutex_lock(&server->refpath_lock);
 550         if (!server->leaf_fullpath) {
 551                 mutex_unlock(&server->refpath_lock);
 552                 return __cifs_reconnect(server, mark_smb_session);
 553         }
 554         mutex_unlock(&server->refpath_lock);
 555
 556         return reconnect_dfs_server(server);
 557 }
 558 #else
 559 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 560 {
 561         return __cifs_reconnect(server, mark_smb_session);
 562 }
 563 #endif
 564
 565 static void
 566 cifs_echo_request(struct work_struct *work)
 567 {
 568         int rc;
 569         struct TCP_Server_Info *server = container_of(work,
 570                                         struct TCP_Server_Info, echo.work);
 571
 572         /*
 573          * We cannot send an echo if it is disabled.
 574          * Also, no need to ping if we got a response recently.
 575          */
 576
 577         if (server->tcpStatus == CifsNeedReconnect ||
 578             server->tcpStatus == CifsExiting ||
 579             server->tcpStatus == CifsNew ||
 580             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 581             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 582                 goto requeue_echo;
 583
 584         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 585         if (rc)
 586                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 587                          server->hostname);
 588
 589         /* Check witness registrations */
 590         cifs_swn_check();
 591
 592 requeue_echo:
 593         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 594 }
 595
 596 static bool
 597 allocate_buffers(struct TCP_Server_Info *server)
 598 {
 599         if (!server->bigbuf) {
 600                 server->bigbuf = (char *)cifs_buf_get();
 601                 if (!server->bigbuf) {
 602                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 603                         msleep(3000);
 604                         /* retry will check if exiting */
 605                         return false;
 606                 }
 607         } else if (server->large_buf) {
 608                 /* we are reusing a dirty large buf, clear its start */
 609                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 610         }
 611
 612         if (!server->smallbuf) {
 613                 server->smallbuf = (char *)cifs_small_buf_get();
 614                 if (!server->smallbuf) {
 615                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 616                         msleep(1000);
 617                         /* retry will check if exiting */
 618                         return false;
 619                 }
 620                 /* beginning of smb buffer is cleared in our buf_get */
 621         } else {
 622                 /* if existing small buf clear beginning */
 623                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 624         }
 625
 626         return true;
 627 }
 628
 629 static bool
 630 server_unresponsive(struct TCP_Server_Info *server)
 631 {
 632         /*
 633          * We need to wait 3 echo intervals to make sure we handle such
 634          * situations right:
 635          * 1s  client sends a normal SMB request
 636          * 2s  client gets a response
 637          * 30s echo workqueue job pops, and decides we got a response recently
 638          *     and don't need to send another
 639          * ...
 640          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 641          *     a response in >60s.
 642          */
 643         spin_lock(&server->srv_lock);
 644         if ((server->tcpStatus == CifsGood ||
 645             server->tcpStatus == CifsNeedNegotiate) &&
 646             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 647             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 648                 spin_unlock(&server->srv_lock);
 649                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 650                          (3 * server->echo_interval) / HZ);
 651                 cifs_reconnect(server, false);
 652                 return true;
 653         }
 654         spin_unlock(&server->srv_lock);
 655
 656         return false;
 657 }
 658
 659 static inline bool
 660 zero_credits(struct TCP_Server_Info *server)
 661 {
 662         int val;
 663
 664         spin_lock(&server->req_lock);
 665         val = server->credits + server->echo_credits + server->oplock_credits;
 666         if (server->in_flight == 0 && val == 0) {
 667                 spin_unlock(&server->req_lock);
 668                 return true;
 669         }
 670         spin_unlock(&server->req_lock);
 671         return false;
 672 }
 673
 674 static int
 675 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 676 {
 677         int length = 0;
 678         int total_read;
 679
 680         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 681                 try_to_freeze();
 682
 683                 /* reconnect if no credits and no requests in flight */
 684                 if (zero_credits(server)) {
 685                         cifs_reconnect(server, false);
 686                         return -ECONNABORTED;
 687                 }
 688
 689                 if (server_unresponsive(server))
 690                         return -ECONNABORTED;
 691                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 692                         length = smbd_recv(server->smbd_conn, smb_msg);
 693                 else
 694                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 695
 696                 spin_lock(&server->srv_lock);
 697                 if (server->tcpStatus == CifsExiting) {
 698                         spin_unlock(&server->srv_lock);
 699                         return -ESHUTDOWN;
 700                 }
 701
 702                 if (server->tcpStatus == CifsNeedReconnect) {
 703                         spin_unlock(&server->srv_lock);
 704                         cifs_reconnect(server, false);
 705                         return -ECONNABORTED;
 706                 }
 707                 spin_unlock(&server->srv_lock);
 708
 709                 if (length == -ERESTARTSYS ||
 710                     length == -EAGAIN ||
 711                     length == -EINTR) {
 712                         /*
 713                          * Minimum sleep to prevent looping, allowing socket
 714                          * to clear and app threads to set tcpStatus
 715                          * CifsNeedReconnect if server hung.
 716                          */
 717                         usleep_range(1000, 2000);
 718                         length = 0;
 719                         continue;
 720                 }
 721
 722                 if (length <= 0) {
 723                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 724                         cifs_reconnect(server, false);
 725                         return -ECONNABORTED;
 726                 }
 727         }
 728         return total_read;
 729 }
 730
 731 int
 732 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 733                       unsigned int to_read)
 734 {
 735         struct msghdr smb_msg = {};
 736         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 737         iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
 738
 739         return cifs_readv_from_socket(server, &smb_msg);
 740 }
 741
 742 ssize_t
 743 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 744 {
 745         struct msghdr smb_msg = {};
 746
 747         /*
 748          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 749          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 750          *  so little to initialize in struct msghdr
 751          */
 752         iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
 753
 754         return cifs_readv_from_socket(server, &smb_msg);
 755 }
 756
 757 int
 758 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 759         unsigned int page_offset, unsigned int to_read)
 760 {
 761         struct msghdr smb_msg = {};
 762         struct bio_vec bv = {
 763                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 764         iov_iter_bvec(&smb_msg.msg_iter, ITER_DEST, &bv, 1, to_read);
 765         return cifs_readv_from_socket(server, &smb_msg);
 766 }
 767
 768 static bool
 769 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 770 {
 771         /*
 772          * The first byte big endian of the length field,
 773          * is actually not part of the length but the type
 774          * with the most common, zero, as regular data.
 775          */
 776         switch (type) {
 777         case RFC1002_SESSION_MESSAGE:
 778                 /* Regular SMB response */
 779                 return true;
 780         case RFC1002_SESSION_KEEP_ALIVE:
 781                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 782                 break;
 783         case RFC1002_POSITIVE_SESSION_RESPONSE:
 784                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 785                 break;
 786         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 787                 /*
 788                  * We get this from Windows 98 instead of an error on
 789                  * SMB negprot response.
 790                  */
 791                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 792                 /* give server a second to clean up */
 793                 msleep(1000);
 794                 /*
 795                  * Always try 445 first on reconnect since we get NACK
 796                  * on some if we ever connected to port 139 (the NACK
 797                  * is since we do not begin with RFC1001 session
 798                  * initialize frame).
 799                  */
 800                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 801                 cifs_reconnect(server, true);
 802                 break;
 803         default:
 804                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 805                 cifs_reconnect(server, true);
 806         }
 807
 808         return false;
 809 }
 810
 811 void
 812 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 813 {
 814 #ifdef CONFIG_CIFS_STATS2
 815         mid->when_received = jiffies;
 816 #endif
 817         spin_lock(&mid->server->mid_lock);
 818         if (!malformed)
 819                 mid->mid_state = MID_RESPONSE_RECEIVED;
 820         else
 821                 mid->mid_state = MID_RESPONSE_MALFORMED;
 822         /*
 823          * Trying to handle/dequeue a mid after the send_recv()
 824          * function has finished processing it is a bug.
 825          */
 826         if (mid->mid_flags & MID_DELETED) {
 827                 spin_unlock(&mid->server->mid_lock);
 828                 pr_warn_once("trying to dequeue a deleted mid\n");
 829         } else {
 830                 list_del_init(&mid->qhead);
 831                 mid->mid_flags |= MID_DELETED;
 832                 spin_unlock(&mid->server->mid_lock);
 833         }
 834 }
 835
 836 static unsigned int
 837 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 838 {
 839         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 840
 841         /*
 842          * SMB1 does not use credits.
 843          */
 844         if (is_smb1(server))
 845                 return 0;
 846
 847         return le16_to_cpu(shdr->CreditRequest);
 848 }
 849
 850 static void
 851 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 852            char *buf, int malformed)
 853 {
 854         if (server->ops->check_trans2 &&
 855             server->ops->check_trans2(mid, server, buf, malformed))
 856                 return;
 857         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 858         mid->resp_buf = buf;
 859         mid->large_buf = server->large_buf;
 860         /* Was previous buf put in mpx struct for multi-rsp? */
 861         if (!mid->multiRsp) {
 862                 /* smb buffer will be freed by user thread */
 863                 if (server->large_buf)
 864                         server->bigbuf = NULL;
 865                 else
 866                         server->smallbuf = NULL;
 867         }
 868         dequeue_mid(mid, malformed);
 869 }
 870
 871 int
 872 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 873 {
 874         bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 875         bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 876         bool mnt_sign_enabled;
 877
 878         /*
 879          * Is signing required by mnt options? If not then check
 880          * global_secflags to see if it is there.
 881          */
 882         if (!mnt_sign_required)
 883                 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 884                                                 CIFSSEC_MUST_SIGN);
 885
 886         /*
 887          * If signing is required then it's automatically enabled too,
 888          * otherwise, check to see if the secflags allow it.
 889          */
 890         mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 891                                 (global_secflags & CIFSSEC_MAY_SIGN);
 892
 893         /* If server requires signing, does client allow it? */
 894         if (srv_sign_required) {
 895                 if (!mnt_sign_enabled) {
 896                         cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 897                         return -EOPNOTSUPP;
 898                 }
 899                 server->sign = true;
 900         }
 901
 902         /* If client requires signing, does server allow it? */
 903         if (mnt_sign_required) {
 904                 if (!srv_sign_enabled) {
 905                         cifs_dbg(VFS, "Server does not support signing!\n");
 906                         return -EOPNOTSUPP;
 907                 }
 908                 server->sign = true;
 909         }
 910
 911         if (cifs_rdma_enabled(server) && server->sign)
 912                 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 913
 914         return 0;
 915 }
 916
 917
 918 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 919 {
 920         int length;
 921
 922         /* take it off the list, if it's not already */
 923         spin_lock(&server->srv_lock);
 924         list_del_init(&server->tcp_ses_list);
 925         spin_unlock(&server->srv_lock);
 926
 927         cancel_delayed_work_sync(&server->echo);
 928         cancel_delayed_work_sync(&server->resolve);
 929
 930         spin_lock(&server->srv_lock);
 931         server->tcpStatus = CifsExiting;
 932         spin_unlock(&server->srv_lock);
 933         wake_up_all(&server->response_q);
 934
 935         /* check if we have blocked requests that need to free */
 936         spin_lock(&server->req_lock);
 937         if (server->credits <= 0)
 938                 server->credits = 1;
 939         spin_unlock(&server->req_lock);
 940         /*
 941          * Although there should not be any requests blocked on this queue it
 942          * can not hurt to be paranoid and try to wake up requests that may
 943          * haven been blocked when more than 50 at time were on the wire to the
 944          * same server - they now will see the session is in exit state and get
 945          * out of SendReceive.
 946          */
 947         wake_up_all(&server->request_q);
 948         /* give those requests time to exit */
 949         msleep(125);
 950         if (cifs_rdma_enabled(server))
 951                 smbd_destroy(server);
 952         if (server->ssocket) {
 953                 sock_release(server->ssocket);
 954                 server->ssocket = NULL;
 955         }
 956
 957         if (!list_empty(&server->pending_mid_q)) {
 958                 struct list_head dispose_list;
 959                 struct mid_q_entry *mid_entry;
 960                 struct list_head *tmp, *tmp2;
 961
 962                 INIT_LIST_HEAD(&dispose_list);
 963                 spin_lock(&server->mid_lock);
 964                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 965                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 966                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 967                         kref_get(&mid_entry->refcount);
 968                         mid_entry->mid_state = MID_SHUTDOWN;
 969                         list_move(&mid_entry->qhead, &dispose_list);
 970                         mid_entry->mid_flags |= MID_DELETED;
 971                 }
 972                 spin_unlock(&server->mid_lock);
 973
 974                 /* now walk dispose list and issue callbacks */
 975                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 976                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 977                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 978                         list_del_init(&mid_entry->qhead);
 979                         mid_entry->callback(mid_entry);
 980                         release_mid(mid_entry);
 981                 }
 982                 /* 1/8th of sec is more than enough time for them to exit */
 983                 msleep(125);
 984         }
 985
 986         if (!list_empty(&server->pending_mid_q)) {
 987                 /*
 988                  * mpx threads have not exited yet give them at least the smb
 989                  * send timeout time for long ops.
 990                  *
 991                  * Due to delays on oplock break requests, we need to wait at
 992                  * least 45 seconds before giving up on a request getting a
 993                  * response and going ahead and killing cifsd.
 994                  */
 995                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 996                 msleep(46000);
 997                 /*
 998                  * If threads still have not exited they are probably never
 999                  * coming home not much else we can do but free the memory.
1000                  */
1001         }
1002
1003 #ifdef CONFIG_CIFS_DFS_UPCALL
1004         kfree(server->origin_fullpath);
1005         kfree(server->leaf_fullpath);
1006 #endif
1007         kfree(server);
1008
1009         length = atomic_dec_return(&tcpSesAllocCount);
1010         if (length > 0)
1011                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1012 }
1013
1014 static int
1015 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1016 {
1017         int length;
1018         char *buf = server->smallbuf;
1019         unsigned int pdu_length = server->pdu_size;
1020
1021         /* make sure this will fit in a large buffer */
1022         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1023             HEADER_PREAMBLE_SIZE(server)) {
1024                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1025                 cifs_reconnect(server, true);
1026                 return -ECONNABORTED;
1027         }
1028
1029         /* switch to large buffer if too big for a small one */
1030         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1031                 server->large_buf = true;
1032                 memcpy(server->bigbuf, buf, server->total_read);
1033                 buf = server->bigbuf;
1034         }
1035
1036         /* now read the rest */
1037         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1038                                        pdu_length - MID_HEADER_SIZE(server));
1039
1040         if (length < 0)
1041                 return length;
1042         server->total_read += length;
1043
1044         dump_smb(buf, server->total_read);
1045
1046         return cifs_handle_standard(server, mid);
1047 }
1048
1049 int
1050 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1051 {
1052         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1053         int rc;
1054
1055         /*
1056          * We know that we received enough to get to the MID as we
1057          * checked the pdu_length earlier. Now check to see
1058          * if the rest of the header is OK.
1059          *
1060          * 48 bytes is enough to display the header and a little bit
1061          * into the payload for debugging purposes.
1062          */
1063         rc = server->ops->check_message(buf, server->total_read, server);
1064         if (rc)
1065                 cifs_dump_mem("Bad SMB: ", buf,
1066                         min_t(unsigned int, server->total_read, 48));
1067
1068         if (server->ops->is_session_expired &&
1069             server->ops->is_session_expired(buf)) {
1070                 cifs_reconnect(server, true);
1071                 return -1;
1072         }
1073
1074         if (server->ops->is_status_pending &&
1075             server->ops->is_status_pending(buf, server))
1076                 return -1;
1077
1078         if (!mid)
1079                 return rc;
1080
1081         handle_mid(mid, server, buf, rc);
1082         return 0;
1083 }
1084
1085 static void
1086 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1087 {
1088         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1089         int scredits, in_flight;
1090
1091         /*
1092          * SMB1 does not use credits.
1093          */
1094         if (is_smb1(server))
1095                 return;
1096
1097         if (shdr->CreditRequest) {
1098                 spin_lock(&server->req_lock);
1099                 server->credits += le16_to_cpu(shdr->CreditRequest);
1100                 scredits = server->credits;
1101                 in_flight = server->in_flight;
1102                 spin_unlock(&server->req_lock);
1103                 wake_up(&server->request_q);
1104
1105                 trace_smb3_hdr_credits(server->CurrentMid,
1106                                 server->conn_id, server->hostname, scredits,
1107                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1108                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1109                                 __func__, le16_to_cpu(shdr->CreditRequest),
1110                                 scredits);
1111         }
1112 }
1113
1114
1115 static int
1116 cifs_demultiplex_thread(void *p)
1117 {
1118         int i, num_mids, length;
1119         struct TCP_Server_Info *server = p;
1120         unsigned int pdu_length;
1121         unsigned int next_offset;
1122         char *buf = NULL;
1123         struct task_struct *task_to_wake = NULL;
1124         struct mid_q_entry *mids[MAX_COMPOUND];
1125         char *bufs[MAX_COMPOUND];
1126         unsigned int noreclaim_flag, num_io_timeout = 0;
1127
1128         noreclaim_flag = memalloc_noreclaim_save();
1129         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1130
1131         length = atomic_inc_return(&tcpSesAllocCount);
1132         if (length > 1)
1133                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1134
1135         set_freezable();
1136         allow_kernel_signal(SIGKILL);
1137         while (server->tcpStatus != CifsExiting) {
1138                 if (try_to_freeze())
1139                         continue;
1140
1141                 if (!allocate_buffers(server))
1142                         continue;
1143
1144                 server->large_buf = false;
1145                 buf = server->smallbuf;
1146                 pdu_length = 4; /* enough to get RFC1001 header */
1147
1148                 length = cifs_read_from_socket(server, buf, pdu_length);
1149                 if (length < 0)
1150                         continue;
1151
1152                 if (is_smb1(server))
1153                         server->total_read = length;
1154                 else
1155                         server->total_read = 0;
1156
1157                 /*
1158                  * The right amount was read from socket - 4 bytes,
1159                  * so we can now interpret the length field.
1160                  */
1161                 pdu_length = get_rfc1002_length(buf);
1162
1163                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1164                 if (!is_smb_response(server, buf[0]))
1165                         continue;
1166 next_pdu:
1167                 server->pdu_size = pdu_length;
1168
1169                 /* make sure we have enough to get to the MID */
1170                 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1171                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1172                                  server->pdu_size);
1173                         cifs_reconnect(server, true);
1174                         continue;
1175                 }
1176
1177                 /* read down to the MID */
1178                 length = cifs_read_from_socket(server,
1179                              buf + HEADER_PREAMBLE_SIZE(server),
1180                              MID_HEADER_SIZE(server));
1181                 if (length < 0)
1182                         continue;
1183                 server->total_read += length;
1184
1185                 if (server->ops->next_header) {
1186                         next_offset = server->ops->next_header(buf);
1187                         if (next_offset)
1188                                 server->pdu_size = next_offset;
1189                 }
1190
1191                 memset(mids, 0, sizeof(mids));
1192                 memset(bufs, 0, sizeof(bufs));
1193                 num_mids = 0;
1194
1195                 if (server->ops->is_transform_hdr &&
1196                     server->ops->receive_transform &&
1197                     server->ops->is_transform_hdr(buf)) {
1198                         length = server->ops->receive_transform(server,
1199                                                                 mids,
1200                                                                 bufs,
1201                                                                 &num_mids);
1202                 } else {
1203                         mids[0] = server->ops->find_mid(server, buf);
1204                         bufs[0] = buf;
1205                         num_mids = 1;
1206
1207                         if (!mids[0] || !mids[0]->receive)
1208                                 length = standard_receive3(server, mids[0]);
1209                         else
1210                                 length = mids[0]->receive(server, mids[0]);
1211                 }
1212
1213                 if (length < 0) {
1214                         for (i = 0; i < num_mids; i++)
1215                                 if (mids[i])
1216                                         release_mid(mids[i]);
1217                         continue;
1218                 }
1219
1220                 if (server->ops->is_status_io_timeout &&
1221                     server->ops->is_status_io_timeout(buf)) {
1222                         num_io_timeout++;
1223                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1224                                 cifs_reconnect(server, false);
1225                                 num_io_timeout = 0;
1226                                 continue;
1227                         }
1228                 }
1229
1230                 server->lstrp = jiffies;
1231
1232                 for (i = 0; i < num_mids; i++) {
1233                         if (mids[i] != NULL) {
1234                                 mids[i]->resp_buf_size = server->pdu_size;
1235
1236                                 if (bufs[i] && server->ops->is_network_name_deleted)
1237                                         server->ops->is_network_name_deleted(bufs[i],
1238                                                                         server);
1239
1240                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1241                                         mids[i]->callback(mids[i]);
1242
1243                                 release_mid(mids[i]);
1244                         } else if (server->ops->is_oplock_break &&
1245                                    server->ops->is_oplock_break(bufs[i],
1246                                                                 server)) {
1247                                 smb2_add_credits_from_hdr(bufs[i], server);
1248                                 cifs_dbg(FYI, "Received oplock break\n");
1249                         } else {
1250                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1251                                                 atomic_read(&mid_count));
1252                                 cifs_dump_mem("Received Data is: ", bufs[i],
1253                                               HEADER_SIZE(server));
1254                                 smb2_add_credits_from_hdr(bufs[i], server);
1255 #ifdef CONFIG_CIFS_DEBUG2
1256                                 if (server->ops->dump_detail)
1257                                         server->ops->dump_detail(bufs[i],
1258                                                                  server);
1259                                 cifs_dump_mids(server);
1260 #endif /* CIFS_DEBUG2 */
1261                         }
1262                 }
1263
1264                 if (pdu_length > server->pdu_size) {
1265                         if (!allocate_buffers(server))
1266                                 continue;
1267                         pdu_length -= server->pdu_size;
1268                         server->total_read = 0;
1269                         server->large_buf = false;
1270                         buf = server->smallbuf;
1271                         goto next_pdu;
1272                 }
1273         } /* end while !EXITING */
1274
1275         /* buffer usually freed in free_mid - need to free it here on exit */
1276         cifs_buf_release(server->bigbuf);
1277         if (server->smallbuf) /* no sense logging a debug message if NULL */
1278                 cifs_small_buf_release(server->smallbuf);
1279
1280         task_to_wake = xchg(&server->tsk, NULL);
1281         clean_demultiplex_info(server);
1282
1283         /* if server->tsk was NULL then wait for a signal before exiting */
1284         if (!task_to_wake) {
1285                 set_current_state(TASK_INTERRUPTIBLE);
1286                 while (!signal_pending(current)) {
1287                         schedule();
1288                         set_current_state(TASK_INTERRUPTIBLE);
1289                 }
1290                 set_current_state(TASK_RUNNING);
1291         }
1292
1293         memalloc_noreclaim_restore(noreclaim_flag);
1294         module_put_and_kthread_exit(0);
1295 }
1296
1297 /*
1298  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1299  * if srcaddr is specified and matches the IP address of the rhs argument
1300  */
1301 bool
1302 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1303 {
1304         switch (srcaddr->sa_family) {
1305         case AF_UNSPEC:
1306                 return (rhs->sa_family == AF_UNSPEC);
1307         case AF_INET: {
1308                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1309                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1310                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1311         }
1312         case AF_INET6: {
1313                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1314                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1315                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1316         }
1317         default:
1318                 WARN_ON(1);
1319                 return false; /* don't expect to be here */
1320         }
1321 }
1322
1323 /*
1324  * If no port is specified in addr structure, we try to match with 445 port
1325  * and if it fails - with 139 ports. It should be called only if address
1326  * families of server and addr are equal.
1327  */
1328 static bool
1329 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1330 {
1331         __be16 port, *sport;
1332
1333         /* SMBDirect manages its own ports, don't match it here */
1334         if (server->rdma)
1335                 return true;
1336
1337         switch (addr->sa_family) {
1338         case AF_INET:
1339                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1340                 port = ((struct sockaddr_in *) addr)->sin_port;
1341                 break;
1342         case AF_INET6:
1343                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1344                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1345                 break;
1346         default:
1347                 WARN_ON(1);
1348                 return false;
1349         }
1350
1351         if (!port) {
1352                 port = htons(CIFS_PORT);
1353                 if (port == *sport)
1354                         return true;
1355
1356                 port = htons(RFC1001_PORT);
1357         }
1358
1359         return port == *sport;
1360 }
1361
1362 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1363 {
1364         switch (addr->sa_family) {
1365         case AF_INET: {
1366                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1367                 struct sockaddr_in *srv_addr4 =
1368                                         (struct sockaddr_in *)&server->dstaddr;
1369
1370                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1371                         return false;
1372                 break;
1373         }
1374         case AF_INET6: {
1375                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1376                 struct sockaddr_in6 *srv_addr6 =
1377                                         (struct sockaddr_in6 *)&server->dstaddr;
1378
1379                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1380                                      &srv_addr6->sin6_addr))
1381                         return false;
1382                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1383                         return false;
1384                 break;
1385         }
1386         default:
1387                 WARN_ON(1);
1388                 return false; /* don't expect to be here */
1389         }
1390
1391         return true;
1392 }
1393
1394 static bool
1395 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1396 {
1397         /*
1398          * The select_sectype function should either return the ctx->sectype
1399          * that was specified, or "Unspecified" if that sectype was not
1400          * compatible with the given NEGOTIATE request.
1401          */
1402         if (server->ops->select_sectype(server, ctx->sectype)
1403              == Unspecified)
1404                 return false;
1405
1406         /*
1407          * Now check if signing mode is acceptable. No need to check
1408          * global_secflags at this point since if MUST_SIGN is set then
1409          * the server->sign had better be too.
1410          */
1411         if (ctx->sign && !server->sign)
1412                 return false;
1413
1414         return true;
1415 }
1416
1417 /* this function must be called with srv_lock held */
1418 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx,
1419                         bool dfs_super_cmp)
1420 {
1421         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1422
1423         if (ctx->nosharesock)
1424                 return 0;
1425
1426         /* this server does not share socket */
1427         if (server->nosharesock)
1428                 return 0;
1429
1430         /* If multidialect negotiation see if existing sessions match one */
1431         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1432                 if (server->vals->protocol_id < SMB30_PROT_ID)
1433                         return 0;
1434         } else if (strcmp(ctx->vals->version_string,
1435                    SMBDEFAULT_VERSION_STRING) == 0) {
1436                 if (server->vals->protocol_id < SMB21_PROT_ID)
1437                         return 0;
1438         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1439                 return 0;
1440
1441         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1442                 return 0;
1443
1444         if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1445                                (struct sockaddr *)&server->srcaddr))
1446                 return 0;
1447         /*
1448          * When matching DFS superblocks, we only check for original source pathname as the
1449          * currently connected target might be different than the one parsed earlier in i.e.
1450          * mount.cifs(8).
1451          */
1452         if (dfs_super_cmp) {
1453                 if (!ctx->source || !server->origin_fullpath ||
1454                     strcasecmp(server->origin_fullpath, ctx->source))
1455                         return 0;
1456         } else {
1457                 /* Skip addr, hostname and port matching for DFS connections */
1458                 if (server->leaf_fullpath) {
1459                         if (!ctx->leaf_fullpath ||
1460                             strcasecmp(server->leaf_fullpath, ctx->leaf_fullpath))
1461                                 return 0;
1462                 } else if (strcasecmp(server->hostname, ctx->server_hostname) ||
1463                            !match_server_address(server, addr) ||
1464                            !match_port(server, addr)) {
1465                         return 0;
1466                 }
1467         }
1468
1469         if (!match_security(server, ctx))
1470                 return 0;
1471
1472         if (server->echo_interval != ctx->echo_interval * HZ)
1473                 return 0;
1474
1475         if (server->rdma != ctx->rdma)
1476                 return 0;
1477
1478         if (server->ignore_signature != ctx->ignore_signature)
1479                 return 0;
1480
1481         if (server->min_offload != ctx->min_offload)
1482                 return 0;
1483
1484         return 1;
1485 }
1486
1487 struct TCP_Server_Info *
1488 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1489 {
1490         struct TCP_Server_Info *server;
1491
1492         spin_lock(&cifs_tcp_ses_lock);
1493         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1494                 spin_lock(&server->srv_lock);
1495                 /*
1496                  * Skip ses channels since they're only handled in lower layers
1497                  * (e.g. cifs_send_recv).
1498                  */
1499                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx, false)) {
1500                         spin_unlock(&server->srv_lock);
1501                         continue;
1502                 }
1503                 spin_unlock(&server->srv_lock);
1504
1505                 ++server->srv_count;
1506                 spin_unlock(&cifs_tcp_ses_lock);
1507                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1508                 return server;
1509         }
1510         spin_unlock(&cifs_tcp_ses_lock);
1511         return NULL;
1512 }
1513
1514 void
1515 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1516 {
1517         struct task_struct *task;
1518
1519         spin_lock(&cifs_tcp_ses_lock);
1520         if (--server->srv_count > 0) {
1521                 spin_unlock(&cifs_tcp_ses_lock);
1522                 return;
1523         }
1524
1525         /* srv_count can never go negative */
1526         WARN_ON(server->srv_count < 0);
1527
1528         put_net(cifs_net_ns(server));
1529
1530         list_del_init(&server->tcp_ses_list);
1531         spin_unlock(&cifs_tcp_ses_lock);
1532
1533         /* For secondary channels, we pick up ref-count on the primary server */
1534         if (CIFS_SERVER_IS_CHAN(server))
1535                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1536
1537         cancel_delayed_work_sync(&server->echo);
1538         cancel_delayed_work_sync(&server->resolve);
1539
1540         if (from_reconnect)
1541                 /*
1542                  * Avoid deadlock here: reconnect work calls
1543                  * cifs_put_tcp_session() at its end. Need to be sure
1544                  * that reconnect work does nothing with server pointer after
1545                  * that step.
1546                  */
1547                 cancel_delayed_work(&server->reconnect);
1548         else
1549                 cancel_delayed_work_sync(&server->reconnect);
1550
1551         spin_lock(&server->srv_lock);
1552         server->tcpStatus = CifsExiting;
1553         spin_unlock(&server->srv_lock);
1554
1555         cifs_crypto_secmech_release(server);
1556
1557         kfree_sensitive(server->session_key.response);
1558         server->session_key.response = NULL;
1559         server->session_key.len = 0;
1560         kfree(server->hostname);
1561         server->hostname = NULL;
1562
1563         task = xchg(&server->tsk, NULL);
1564         if (task)
1565                 send_sig(SIGKILL, task, 1);
1566 }
1567
1568 struct TCP_Server_Info *
1569 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1570                      struct TCP_Server_Info *primary_server)
1571 {
1572         struct TCP_Server_Info *tcp_ses = NULL;
1573         int rc;
1574
1575         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1576
1577         /* see if we already have a matching tcp_ses */
1578         tcp_ses = cifs_find_tcp_session(ctx);
1579         if (tcp_ses)
1580                 return tcp_ses;
1581
1582         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1583         if (!tcp_ses) {
1584                 rc = -ENOMEM;
1585                 goto out_err;
1586         }
1587
1588         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1589         if (!tcp_ses->hostname) {
1590                 rc = -ENOMEM;
1591                 goto out_err;
1592         }
1593
1594         if (ctx->leaf_fullpath) {
1595                 tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1596                 if (!tcp_ses->leaf_fullpath) {
1597                         rc = -ENOMEM;
1598                         goto out_err;
1599                 }
1600                 tcp_ses->current_fullpath = tcp_ses->leaf_fullpath;
1601         }
1602
1603         if (ctx->nosharesock)
1604                 tcp_ses->nosharesock = true;
1605
1606         tcp_ses->ops = ctx->ops;
1607         tcp_ses->vals = ctx->vals;
1608         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1609
1610         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1611         tcp_ses->noblockcnt = ctx->rootfs;
1612         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1613         tcp_ses->noautotune = ctx->noautotune;
1614         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1615         tcp_ses->rdma = ctx->rdma;
1616         tcp_ses->in_flight = 0;
1617         tcp_ses->max_in_flight = 0;
1618         tcp_ses->credits = 1;
1619         if (primary_server) {
1620                 spin_lock(&cifs_tcp_ses_lock);
1621                 ++primary_server->srv_count;
1622                 spin_unlock(&cifs_tcp_ses_lock);
1623                 tcp_ses->primary_server = primary_server;
1624         }
1625         init_waitqueue_head(&tcp_ses->response_q);
1626         init_waitqueue_head(&tcp_ses->request_q);
1627         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1628         mutex_init(&tcp_ses->_srv_mutex);
1629         memcpy(tcp_ses->workstation_RFC1001_name,
1630                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1631         memcpy(tcp_ses->server_RFC1001_name,
1632                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1633         tcp_ses->session_estab = false;
1634         tcp_ses->sequence_number = 0;
1635         tcp_ses->reconnect_instance = 1;
1636         tcp_ses->lstrp = jiffies;
1637         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1638         spin_lock_init(&tcp_ses->req_lock);
1639         spin_lock_init(&tcp_ses->srv_lock);
1640         spin_lock_init(&tcp_ses->mid_lock);
1641         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1642         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1643         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1644         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1645         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1646         mutex_init(&tcp_ses->reconnect_mutex);
1647 #ifdef CONFIG_CIFS_DFS_UPCALL
1648         mutex_init(&tcp_ses->refpath_lock);
1649 #endif
1650         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1651                sizeof(tcp_ses->srcaddr));
1652         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1653                 sizeof(tcp_ses->dstaddr));
1654         if (ctx->use_client_guid)
1655                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1656                        SMB2_CLIENT_GUID_SIZE);
1657         else
1658                 generate_random_uuid(tcp_ses->client_guid);
1659         /*
1660          * at this point we are the only ones with the pointer
1661          * to the struct since the kernel thread not created yet
1662          * no need to spinlock this init of tcpStatus or srv_count
1663          */
1664         tcp_ses->tcpStatus = CifsNew;
1665         ++tcp_ses->srv_count;
1666
1667         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1668                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1669                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1670         else
1671                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1672         if (tcp_ses->rdma) {
1673 #ifndef CONFIG_CIFS_SMB_DIRECT
1674                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1675                 rc = -ENOENT;
1676                 goto out_err_crypto_release;
1677 #endif
1678                 tcp_ses->smbd_conn = smbd_get_connection(
1679                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1680                 if (tcp_ses->smbd_conn) {
1681                         cifs_dbg(VFS, "RDMA transport established\n");
1682                         rc = 0;
1683                         goto smbd_connected;
1684                 } else {
1685                         rc = -ENOENT;
1686                         goto out_err_crypto_release;
1687                 }
1688         }
1689         rc = ip_connect(tcp_ses);
1690         if (rc < 0) {
1691                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1692                 goto out_err_crypto_release;
1693         }
1694 smbd_connected:
1695         /*
1696          * since we're in a cifs function already, we know that
1697          * this will succeed. No need for try_module_get().
1698          */
1699         __module_get(THIS_MODULE);
1700         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1701                                   tcp_ses, "cifsd");
1702         if (IS_ERR(tcp_ses->tsk)) {
1703                 rc = PTR_ERR(tcp_ses->tsk);
1704                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1705                 module_put(THIS_MODULE);
1706                 goto out_err_crypto_release;
1707         }
1708         tcp_ses->min_offload = ctx->min_offload;
1709         /*
1710          * at this point we are the only ones with the pointer
1711          * to the struct since the kernel thread not created yet
1712          * no need to spinlock this update of tcpStatus
1713          */
1714         spin_lock(&tcp_ses->srv_lock);
1715         tcp_ses->tcpStatus = CifsNeedNegotiate;
1716         spin_unlock(&tcp_ses->srv_lock);
1717
1718         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1719                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1720         else
1721                 tcp_ses->max_credits = ctx->max_credits;
1722
1723         tcp_ses->nr_targets = 1;
1724         tcp_ses->ignore_signature = ctx->ignore_signature;
1725         /* thread spawned, put it on the list */
1726         spin_lock(&cifs_tcp_ses_lock);
1727         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1728         spin_unlock(&cifs_tcp_ses_lock);
1729
1730         /* queue echo request delayed work */
1731         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1732
1733         /* queue dns resolution delayed work */
1734         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1735                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1736
1737         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1738
1739         return tcp_ses;
1740
1741 out_err_crypto_release:
1742         cifs_crypto_secmech_release(tcp_ses);
1743
1744         put_net(cifs_net_ns(tcp_ses));
1745
1746 out_err:
1747         if (tcp_ses) {
1748                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1749                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1750                 kfree(tcp_ses->hostname);
1751                 kfree(tcp_ses->leaf_fullpath);
1752                 if (tcp_ses->ssocket)
1753                         sock_release(tcp_ses->ssocket);
1754                 kfree(tcp_ses);
1755         }
1756         return ERR_PTR(rc);
1757 }
1758
1759 /* this function must be called with ses_lock held */
1760 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1761 {
1762         if (ctx->sectype != Unspecified &&
1763             ctx->sectype != ses->sectype)
1764                 return 0;
1765
1766         /*
1767          * If an existing session is limited to less channels than
1768          * requested, it should not be reused
1769          */
1770         spin_lock(&ses->chan_lock);
1771         if (ses->chan_max < ctx->max_channels) {
1772                 spin_unlock(&ses->chan_lock);
1773                 return 0;
1774         }
1775         spin_unlock(&ses->chan_lock);
1776
1777         switch (ses->sectype) {
1778         case Kerberos:
1779                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1780                         return 0;
1781                 break;
1782         default:
1783                 /* NULL username means anonymous session */
1784                 if (ses->user_name == NULL) {
1785                         if (!ctx->nullauth)
1786                                 return 0;
1787                         break;
1788                 }
1789
1790                 /* anything else takes username/password */
1791                 if (strncmp(ses->user_name,
1792                             ctx->username ? ctx->username : "",
1793                             CIFS_MAX_USERNAME_LEN))
1794                         return 0;
1795                 if ((ctx->username && strlen(ctx->username) != 0) &&
1796                     ses->password != NULL &&
1797                     strncmp(ses->password,
1798                             ctx->password ? ctx->password : "",
1799                             CIFS_MAX_PASSWORD_LEN))
1800                         return 0;
1801         }
1802         return 1;
1803 }
1804
1805 /**
1806  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1807  * @ses: smb session to issue the request on
1808  * @ctx: the superblock configuration context to use for building the
1809  *       new tree connection for the IPC (interprocess communication RPC)
1810  *
1811  * A new IPC connection is made and stored in the session
1812  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1813  */
1814 static int
1815 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1816 {
1817         int rc = 0, xid;
1818         struct cifs_tcon *tcon;
1819         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1820         bool seal = false;
1821         struct TCP_Server_Info *server = ses->server;
1822
1823         /*
1824          * If the mount request that resulted in the creation of the
1825          * session requires encryption, force IPC to be encrypted too.
1826          */
1827         if (ctx->seal) {
1828                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1829                         seal = true;
1830                 else {
1831                         cifs_server_dbg(VFS,
1832                                  "IPC: server doesn't support encryption\n");
1833                         return -EOPNOTSUPP;
1834                 }
1835         }
1836
1837         tcon = tconInfoAlloc();
1838         if (tcon == NULL)
1839                 return -ENOMEM;
1840
1841         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1842
1843         xid = get_xid();
1844         tcon->ses = ses;
1845         tcon->ipc = true;
1846         tcon->seal = seal;
1847         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1848         free_xid(xid);
1849
1850         if (rc) {
1851                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1852                 tconInfoFree(tcon);
1853                 goto out;
1854         }
1855
1856         cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1857
1858         spin_lock(&tcon->tc_lock);
1859         tcon->status = TID_GOOD;
1860         spin_unlock(&tcon->tc_lock);
1861         ses->tcon_ipc = tcon;
1862 out:
1863         return rc;
1864 }
1865
1866 /**
1867  * cifs_free_ipc - helper to release the session IPC tcon
1868  * @ses: smb session to unmount the IPC from
1869  *
1870  * Needs to be called everytime a session is destroyed.
1871  *
1872  * On session close, the IPC is closed and the server must release all tcons of the session.
1873  * No need to send a tree disconnect here.
1874  *
1875  * Besides, it will make the server to not close durable and resilient files on session close, as
1876  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1877  */
1878 static int
1879 cifs_free_ipc(struct cifs_ses *ses)
1880 {
1881         struct cifs_tcon *tcon = ses->tcon_ipc;
1882
1883         if (tcon == NULL)
1884                 return 0;
1885
1886         tconInfoFree(tcon);
1887         ses->tcon_ipc = NULL;
1888         return 0;
1889 }
1890
1891 static struct cifs_ses *
1892 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1893 {
1894         struct cifs_ses *ses;
1895
1896         spin_lock(&cifs_tcp_ses_lock);
1897         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1898                 spin_lock(&ses->ses_lock);
1899                 if (ses->ses_status == SES_EXITING) {
1900                         spin_unlock(&ses->ses_lock);
1901                         continue;
1902                 }
1903                 if (!match_session(ses, ctx)) {
1904                         spin_unlock(&ses->ses_lock);
1905                         continue;
1906                 }
1907                 spin_unlock(&ses->ses_lock);
1908
1909                 ++ses->ses_count;
1910                 spin_unlock(&cifs_tcp_ses_lock);
1911                 return ses;
1912         }
1913         spin_unlock(&cifs_tcp_ses_lock);
1914         return NULL;
1915 }
1916
1917 void cifs_put_smb_ses(struct cifs_ses *ses)
1918 {
1919         unsigned int rc, xid;
1920         unsigned int chan_count;
1921         struct TCP_Server_Info *server = ses->server;
1922
1923         spin_lock(&ses->ses_lock);
1924         if (ses->ses_status == SES_EXITING) {
1925                 spin_unlock(&ses->ses_lock);
1926                 return;
1927         }
1928         spin_unlock(&ses->ses_lock);
1929
1930         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1931         cifs_dbg(FYI,
1932                  "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1933
1934         spin_lock(&cifs_tcp_ses_lock);
1935         if (--ses->ses_count > 0) {
1936                 spin_unlock(&cifs_tcp_ses_lock);
1937                 return;
1938         }
1939         spin_unlock(&cifs_tcp_ses_lock);
1940
1941         /* ses_count can never go negative */
1942         WARN_ON(ses->ses_count < 0);
1943
1944         if (ses->ses_status == SES_GOOD)
1945                 ses->ses_status = SES_EXITING;
1946
1947         cifs_free_ipc(ses);
1948
1949         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1950                 xid = get_xid();
1951                 rc = server->ops->logoff(xid, ses);
1952                 if (rc)
1953                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1954                                 __func__, rc);
1955                 _free_xid(xid);
1956         }
1957
1958         spin_lock(&cifs_tcp_ses_lock);
1959         list_del_init(&ses->smb_ses_list);
1960         spin_unlock(&cifs_tcp_ses_lock);
1961
1962         chan_count = ses->chan_count;
1963
1964         /* close any extra channels */
1965         if (chan_count > 1) {
1966                 int i;
1967
1968                 for (i = 1; i < chan_count; i++) {
1969                         if (ses->chans[i].iface) {
1970                                 kref_put(&ses->chans[i].iface->refcount, release_iface);
1971                                 ses->chans[i].iface = NULL;
1972                         }
1973                         cifs_put_tcp_session(ses->chans[i].server, 0);
1974                         ses->chans[i].server = NULL;
1975                 }
1976         }
1977
1978         sesInfoFree(ses);
1979         cifs_put_tcp_session(server, 0);
1980 }
1981
1982 #ifdef CONFIG_KEYS
1983
1984 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1985 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1986
1987 /* Populate username and pw fields from keyring if possible */
1988 static int
1989 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1990 {
1991         int rc = 0;
1992         int is_domain = 0;
1993         const char *delim, *payload;
1994         char *desc;
1995         ssize_t len;
1996         struct key *key;
1997         struct TCP_Server_Info *server = ses->server;
1998         struct sockaddr_in *sa;
1999         struct sockaddr_in6 *sa6;
2000         const struct user_key_payload *upayload;
2001
2002         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2003         if (!desc)
2004                 return -ENOMEM;
2005
2006         /* try to find an address key first */
2007         switch (server->dstaddr.ss_family) {
2008         case AF_INET:
2009                 sa = (struct sockaddr_in *)&server->dstaddr;
2010                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2011                 break;
2012         case AF_INET6:
2013                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2014                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2015                 break;
2016         default:
2017                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2018                          server->dstaddr.ss_family);
2019                 rc = -EINVAL;
2020                 goto out_err;
2021         }
2022
2023         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2024         key = request_key(&key_type_logon, desc, "");
2025         if (IS_ERR(key)) {
2026                 if (!ses->domainName) {
2027                         cifs_dbg(FYI, "domainName is NULL\n");
2028                         rc = PTR_ERR(key);
2029                         goto out_err;
2030                 }
2031
2032                 /* didn't work, try to find a domain key */
2033                 sprintf(desc, "cifs:d:%s", ses->domainName);
2034                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2035                 key = request_key(&key_type_logon, desc, "");
2036                 if (IS_ERR(key)) {
2037                         rc = PTR_ERR(key);
2038                         goto out_err;
2039                 }
2040                 is_domain = 1;
2041         }
2042
2043         down_read(&key->sem);
2044         upayload = user_key_payload_locked(key);
2045         if (IS_ERR_OR_NULL(upayload)) {
2046                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2047                 goto out_key_put;
2048         }
2049
2050         /* find first : in payload */
2051         payload = upayload->data;
2052         delim = strnchr(payload, upayload->datalen, ':');
2053         cifs_dbg(FYI, "payload=%s\n", payload);
2054         if (!delim) {
2055                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2056                          upayload->datalen);
2057                 rc = -EINVAL;
2058                 goto out_key_put;
2059         }
2060
2061         len = delim - payload;
2062         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2063                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2064                          len);
2065                 rc = -EINVAL;
2066                 goto out_key_put;
2067         }
2068
2069         ctx->username = kstrndup(payload, len, GFP_KERNEL);
2070         if (!ctx->username) {
2071                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2072                          len);
2073                 rc = -ENOMEM;
2074                 goto out_key_put;
2075         }
2076         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2077
2078         len = key->datalen - (len + 1);
2079         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2080                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2081                 rc = -EINVAL;
2082                 kfree(ctx->username);
2083                 ctx->username = NULL;
2084                 goto out_key_put;
2085         }
2086
2087         ++delim;
2088         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2089         if (!ctx->password) {
2090                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2091                          len);
2092                 rc = -ENOMEM;
2093                 kfree(ctx->username);
2094                 ctx->username = NULL;
2095                 goto out_key_put;
2096         }
2097
2098         /*
2099          * If we have a domain key then we must set the domainName in the
2100          * for the request.
2101          */
2102         if (is_domain && ses->domainName) {
2103                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2104                 if (!ctx->domainname) {
2105                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2106                                  len);
2107                         rc = -ENOMEM;
2108                         kfree(ctx->username);
2109                         ctx->username = NULL;
2110                         kfree_sensitive(ctx->password);
2111                         ctx->password = NULL;
2112                         goto out_key_put;
2113                 }
2114         }
2115
2116         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2117
2118 out_key_put:
2119         up_read(&key->sem);
2120         key_put(key);
2121 out_err:
2122         kfree(desc);
2123         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2124         return rc;
2125 }
2126 #else /* ! CONFIG_KEYS */
2127 static inline int
2128 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2129                    struct cifs_ses *ses __attribute__((unused)))
2130 {
2131         return -ENOSYS;
2132 }
2133 #endif /* CONFIG_KEYS */
2134
2135 /**
2136  * cifs_get_smb_ses - get a session matching @ctx data from @server
2137  * @server: server to setup the session to
2138  * @ctx: superblock configuration context to use to setup the session
2139  *
2140  * This function assumes it is being called from cifs_mount() where we
2141  * already got a server reference (server refcount +1). See
2142  * cifs_get_tcon() for refcount explanations.
2143  */
2144 struct cifs_ses *
2145 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2146 {
2147         int rc = -ENOMEM;
2148         unsigned int xid;
2149         struct cifs_ses *ses;
2150         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2151         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2152
2153         xid = get_xid();
2154
2155         ses = cifs_find_smb_ses(server, ctx);
2156         if (ses) {
2157                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2158                          ses->ses_status);
2159
2160                 spin_lock(&ses->chan_lock);
2161                 if (cifs_chan_needs_reconnect(ses, server)) {
2162                         spin_unlock(&ses->chan_lock);
2163                         cifs_dbg(FYI, "Session needs reconnect\n");
2164
2165                         mutex_lock(&ses->session_mutex);
2166                         rc = cifs_negotiate_protocol(xid, ses, server);
2167                         if (rc) {
2168                                 mutex_unlock(&ses->session_mutex);
2169                                 /* problem -- put our ses reference */
2170                                 cifs_put_smb_ses(ses);
2171                                 free_xid(xid);
2172                                 return ERR_PTR(rc);
2173                         }
2174
2175                         rc = cifs_setup_session(xid, ses, server,
2176                                                 ctx->local_nls);
2177                         if (rc) {
2178                                 mutex_unlock(&ses->session_mutex);
2179                                 /* problem -- put our reference */
2180                                 cifs_put_smb_ses(ses);
2181                                 free_xid(xid);
2182                                 return ERR_PTR(rc);
2183                         }
2184                         mutex_unlock(&ses->session_mutex);
2185
2186                         spin_lock(&ses->chan_lock);
2187                 }
2188                 spin_unlock(&ses->chan_lock);
2189
2190                 /* existing SMB ses has a server reference already */
2191                 cifs_put_tcp_session(server, 0);
2192                 free_xid(xid);
2193                 return ses;
2194         }
2195
2196         cifs_dbg(FYI, "Existing smb sess not found\n");
2197         ses = sesInfoAlloc();
2198         if (ses == NULL)
2199                 goto get_ses_fail;
2200
2201         /* new SMB session uses our server ref */
2202         ses->server = server;
2203         if (server->dstaddr.ss_family == AF_INET6)
2204                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2205         else
2206                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2207
2208         if (ctx->username) {
2209                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2210                 if (!ses->user_name)
2211                         goto get_ses_fail;
2212         }
2213
2214         /* ctx->password freed at unmount */
2215         if (ctx->password) {
2216                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2217                 if (!ses->password)
2218                         goto get_ses_fail;
2219         }
2220         if (ctx->domainname) {
2221                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2222                 if (!ses->domainName)
2223                         goto get_ses_fail;
2224         }
2225
2226         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2227
2228         if (ctx->domainauto)
2229                 ses->domainAuto = ctx->domainauto;
2230         ses->cred_uid = ctx->cred_uid;
2231         ses->linux_uid = ctx->linux_uid;
2232
2233         ses->sectype = ctx->sectype;
2234         ses->sign = ctx->sign;
2235
2236         /* add server as first channel */
2237         spin_lock(&ses->chan_lock);
2238         ses->chans[0].server = server;
2239         ses->chan_count = 1;
2240         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2241         ses->chans_need_reconnect = 1;
2242         spin_unlock(&ses->chan_lock);
2243
2244         mutex_lock(&ses->session_mutex);
2245         rc = cifs_negotiate_protocol(xid, ses, server);
2246         if (!rc)
2247                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2248         mutex_unlock(&ses->session_mutex);
2249
2250         /* each channel uses a different signing key */
2251         spin_lock(&ses->chan_lock);
2252         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2253                sizeof(ses->smb3signingkey));
2254         spin_unlock(&ses->chan_lock);
2255
2256         if (rc)
2257                 goto get_ses_fail;
2258
2259         /*
2260          * success, put it on the list and add it as first channel
2261          * note: the session becomes active soon after this. So you'll
2262          * need to lock before changing something in the session.
2263          */
2264         spin_lock(&cifs_tcp_ses_lock);
2265         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2266         spin_unlock(&cifs_tcp_ses_lock);
2267
2268         cifs_setup_ipc(ses, ctx);
2269
2270         free_xid(xid);
2271
2272         return ses;
2273
2274 get_ses_fail:
2275         sesInfoFree(ses);
2276         free_xid(xid);
2277         return ERR_PTR(rc);
2278 }
2279
2280 /* this function must be called with tc_lock held */
2281 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx, bool dfs_super_cmp)
2282 {
2283         if (tcon->status == TID_EXITING)
2284                 return 0;
2285         /* Skip UNC validation when matching DFS superblocks */
2286         if (!dfs_super_cmp && strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2287                 return 0;
2288         if (tcon->seal != ctx->seal)
2289                 return 0;
2290         if (tcon->snapshot_time != ctx->snapshot_time)
2291                 return 0;
2292         if (tcon->handle_timeout != ctx->handle_timeout)
2293                 return 0;
2294         if (tcon->no_lease != ctx->no_lease)
2295                 return 0;
2296         if (tcon->nodelete != ctx->nodelete)
2297                 return 0;
2298         return 1;
2299 }
2300
2301 static struct cifs_tcon *
2302 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2303 {
2304         struct cifs_tcon *tcon;
2305
2306         spin_lock(&cifs_tcp_ses_lock);
2307         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2308                 spin_lock(&tcon->tc_lock);
2309                 if (!match_tcon(tcon, ctx, false)) {
2310                         spin_unlock(&tcon->tc_lock);
2311                         continue;
2312                 }
2313                 ++tcon->tc_count;
2314                 spin_unlock(&tcon->tc_lock);
2315                 spin_unlock(&cifs_tcp_ses_lock);
2316                 return tcon;
2317         }
2318         spin_unlock(&cifs_tcp_ses_lock);
2319         return NULL;
2320 }
2321
2322 void
2323 cifs_put_tcon(struct cifs_tcon *tcon)
2324 {
2325         unsigned int xid;
2326         struct cifs_ses *ses;
2327
2328         /*
2329          * IPC tcon share the lifetime of their session and are
2330          * destroyed in the session put function
2331          */
2332         if (tcon == NULL || tcon->ipc)
2333                 return;
2334
2335         ses = tcon->ses;
2336         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2337         spin_lock(&cifs_tcp_ses_lock);
2338         spin_lock(&tcon->tc_lock);
2339         if (--tcon->tc_count > 0) {
2340                 spin_unlock(&tcon->tc_lock);
2341                 spin_unlock(&cifs_tcp_ses_lock);
2342                 return;
2343         }
2344
2345         /* tc_count can never go negative */
2346         WARN_ON(tcon->tc_count < 0);
2347
2348         list_del_init(&tcon->tcon_list);
2349         spin_unlock(&tcon->tc_lock);
2350         spin_unlock(&cifs_tcp_ses_lock);
2351
2352         /* cancel polling of interfaces */
2353         cancel_delayed_work_sync(&tcon->query_interfaces);
2354
2355         if (tcon->use_witness) {
2356                 int rc;
2357
2358                 rc = cifs_swn_unregister(tcon);
2359                 if (rc < 0) {
2360                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2361                                         __func__, rc);
2362                 }
2363         }
2364
2365         xid = get_xid();
2366         if (ses->server->ops->tree_disconnect)
2367                 ses->server->ops->tree_disconnect(xid, tcon);
2368         _free_xid(xid);
2369
2370         cifs_fscache_release_super_cookie(tcon);
2371         tconInfoFree(tcon);
2372         cifs_put_smb_ses(ses);
2373 }
2374
2375 /**
2376  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2377  * @ses: smb session to issue the request on
2378  * @ctx: the superblock configuration context to use for building the
2379  *
2380  * - tcon refcount is the number of mount points using the tcon.
2381  * - ses refcount is the number of tcon using the session.
2382  *
2383  * 1. This function assumes it is being called from cifs_mount() where
2384  *    we already got a session reference (ses refcount +1).
2385  *
2386  * 2. Since we're in the context of adding a mount point, the end
2387  *    result should be either:
2388  *
2389  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2390  *    its session refcount incremented (1 new tcon). This +1 was
2391  *    already done in (1).
2392  *
2393  * b) an existing tcon with refcount+1 (add a mount point to it) and
2394  *    identical ses refcount (no new tcon). Because of (1) we need to
2395  *    decrement the ses refcount.
2396  */
2397 static struct cifs_tcon *
2398 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2399 {
2400         int rc, xid;
2401         struct cifs_tcon *tcon;
2402
2403         tcon = cifs_find_tcon(ses, ctx);
2404         if (tcon) {
2405                 /*
2406                  * tcon has refcount already incremented but we need to
2407                  * decrement extra ses reference gotten by caller (case b)
2408                  */
2409                 cifs_dbg(FYI, "Found match on UNC path\n");
2410                 cifs_put_smb_ses(ses);
2411                 return tcon;
2412         }
2413
2414         if (!ses->server->ops->tree_connect) {
2415                 rc = -ENOSYS;
2416                 goto out_fail;
2417         }
2418
2419         tcon = tconInfoAlloc();
2420         if (tcon == NULL) {
2421                 rc = -ENOMEM;
2422                 goto out_fail;
2423         }
2424
2425         if (ctx->snapshot_time) {
2426                 if (ses->server->vals->protocol_id == 0) {
2427                         cifs_dbg(VFS,
2428                              "Use SMB2 or later for snapshot mount option\n");
2429                         rc = -EOPNOTSUPP;
2430                         goto out_fail;
2431                 } else
2432                         tcon->snapshot_time = ctx->snapshot_time;
2433         }
2434
2435         if (ctx->handle_timeout) {
2436                 if (ses->server->vals->protocol_id == 0) {
2437                         cifs_dbg(VFS,
2438                              "Use SMB2.1 or later for handle timeout option\n");
2439                         rc = -EOPNOTSUPP;
2440                         goto out_fail;
2441                 } else
2442                         tcon->handle_timeout = ctx->handle_timeout;
2443         }
2444
2445         tcon->ses = ses;
2446         if (ctx->password) {
2447                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2448                 if (!tcon->password) {
2449                         rc = -ENOMEM;
2450                         goto out_fail;
2451                 }
2452         }
2453
2454         if (ctx->seal) {
2455                 if (ses->server->vals->protocol_id == 0) {
2456                         cifs_dbg(VFS,
2457                                  "SMB3 or later required for encryption\n");
2458                         rc = -EOPNOTSUPP;
2459                         goto out_fail;
2460                 } else if (tcon->ses->server->capabilities &
2461                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2462                         tcon->seal = true;
2463                 else {
2464                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2465                         rc = -EOPNOTSUPP;
2466                         goto out_fail;
2467                 }
2468         }
2469
2470         if (ctx->linux_ext) {
2471                 if (ses->server->posix_ext_supported) {
2472                         tcon->posix_extensions = true;
2473                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2474                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2475                     (strcmp(ses->server->vals->version_string,
2476                      SMB3ANY_VERSION_STRING) == 0) ||
2477                     (strcmp(ses->server->vals->version_string,
2478                      SMBDEFAULT_VERSION_STRING) == 0)) {
2479                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2480                         rc = -EOPNOTSUPP;
2481                         goto out_fail;
2482                 } else {
2483                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2484                                 "disabled but required for POSIX extensions\n");
2485                         rc = -EOPNOTSUPP;
2486                         goto out_fail;
2487                 }
2488         }
2489
2490         xid = get_xid();
2491         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2492                                             ctx->local_nls);
2493         free_xid(xid);
2494         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2495         if (rc)
2496                 goto out_fail;
2497
2498         tcon->use_persistent = false;
2499         /* check if SMB2 or later, CIFS does not support persistent handles */
2500         if (ctx->persistent) {
2501                 if (ses->server->vals->protocol_id == 0) {
2502                         cifs_dbg(VFS,
2503                              "SMB3 or later required for persistent handles\n");
2504                         rc = -EOPNOTSUPP;
2505                         goto out_fail;
2506                 } else if (ses->server->capabilities &
2507                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2508                         tcon->use_persistent = true;
2509                 else /* persistent handles requested but not supported */ {
2510                         cifs_dbg(VFS,
2511                                 "Persistent handles not supported on share\n");
2512                         rc = -EOPNOTSUPP;
2513                         goto out_fail;
2514                 }
2515         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2516              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2517              && (ctx->nopersistent == false)) {
2518                 cifs_dbg(FYI, "enabling persistent handles\n");
2519                 tcon->use_persistent = true;
2520         } else if (ctx->resilient) {
2521                 if (ses->server->vals->protocol_id == 0) {
2522                         cifs_dbg(VFS,
2523                              "SMB2.1 or later required for resilient handles\n");
2524                         rc = -EOPNOTSUPP;
2525                         goto out_fail;
2526                 }
2527                 tcon->use_resilient = true;
2528         }
2529
2530         tcon->use_witness = false;
2531         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2532                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2533                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2534                                 /*
2535                                  * Set witness in use flag in first place
2536                                  * to retry registration in the echo task
2537                                  */
2538                                 tcon->use_witness = true;
2539                                 /* And try to register immediately */
2540                                 rc = cifs_swn_register(tcon);
2541                                 if (rc < 0) {
2542                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2543                                         goto out_fail;
2544                                 }
2545                         } else {
2546                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2547                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2548                                 rc = -EOPNOTSUPP;
2549                                 goto out_fail;
2550                         }
2551                 } else {
2552                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2553                         rc = -EOPNOTSUPP;
2554                         goto out_fail;
2555                 }
2556         }
2557
2558         /* If the user really knows what they are doing they can override */
2559         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2560                 if (ctx->cache_ro)
2561                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2562                 else if (ctx->cache_rw)
2563                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2564         }
2565
2566         if (ctx->no_lease) {
2567                 if (ses->server->vals->protocol_id == 0) {
2568                         cifs_dbg(VFS,
2569                                 "SMB2 or later required for nolease option\n");
2570                         rc = -EOPNOTSUPP;
2571                         goto out_fail;
2572                 } else
2573                         tcon->no_lease = ctx->no_lease;
2574         }
2575
2576         /*
2577          * We can have only one retry value for a connection to a share so for
2578          * resources mounted more than once to the same server share the last
2579          * value passed in for the retry flag is used.
2580          */
2581         tcon->retry = ctx->retry;
2582         tcon->nocase = ctx->nocase;
2583         tcon->broken_sparse_sup = ctx->no_sparse;
2584         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2585                 tcon->nohandlecache = ctx->nohandlecache;
2586         else
2587                 tcon->nohandlecache = true;
2588         tcon->nodelete = ctx->nodelete;
2589         tcon->local_lease = ctx->local_lease;
2590         INIT_LIST_HEAD(&tcon->pending_opens);
2591         tcon->status = TID_GOOD;
2592
2593         /* schedule query interfaces poll */
2594         INIT_DELAYED_WORK(&tcon->query_interfaces,
2595                           smb2_query_server_interfaces);
2596         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2597                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
2598
2599         spin_lock(&cifs_tcp_ses_lock);
2600         list_add(&tcon->tcon_list, &ses->tcon_list);
2601         spin_unlock(&cifs_tcp_ses_lock);
2602
2603         return tcon;
2604
2605 out_fail:
2606         tconInfoFree(tcon);
2607         return ERR_PTR(rc);
2608 }
2609
2610 void
2611 cifs_put_tlink(struct tcon_link *tlink)
2612 {
2613         if (!tlink || IS_ERR(tlink))
2614                 return;
2615
2616         if (!atomic_dec_and_test(&tlink->tl_count) ||
2617             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2618                 tlink->tl_time = jiffies;
2619                 return;
2620         }
2621
2622         if (!IS_ERR(tlink_tcon(tlink)))
2623                 cifs_put_tcon(tlink_tcon(tlink));
2624         kfree(tlink);
2625         return;
2626 }
2627
2628 static int
2629 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2630 {
2631         struct cifs_sb_info *old = CIFS_SB(sb);
2632         struct cifs_sb_info *new = mnt_data->cifs_sb;
2633         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2634         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2635
2636         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2637                 return 0;
2638
2639         if (old->mnt_cifs_serverino_autodisabled)
2640                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2641
2642         if (oldflags != newflags)
2643                 return 0;
2644
2645         /*
2646          * We want to share sb only if we don't specify an r/wsize or
2647          * specified r/wsize is greater than or equal to existing one.
2648          */
2649         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2650                 return 0;
2651
2652         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2653                 return 0;
2654
2655         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2656             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2657                 return 0;
2658
2659         if (old->ctx->file_mode != new->ctx->file_mode ||
2660             old->ctx->dir_mode != new->ctx->dir_mode)
2661                 return 0;
2662
2663         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2664                 return 0;
2665
2666         if (old->ctx->acregmax != new->ctx->acregmax)
2667                 return 0;
2668         if (old->ctx->acdirmax != new->ctx->acdirmax)
2669                 return 0;
2670         if (old->ctx->closetimeo != new->ctx->closetimeo)
2671                 return 0;
2672
2673         return 1;
2674 }
2675
2676 static int
2677 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2678 {
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 (old_set && new_set && !strcmp(new->prepath, old->prepath))
2687                 return 1;
2688         else if (!old_set && !new_set)
2689                 return 1;
2690
2691         return 0;
2692 }
2693
2694 int
2695 cifs_match_super(struct super_block *sb, void *data)
2696 {
2697         struct cifs_mnt_data *mnt_data = data;
2698         struct smb3_fs_context *ctx;
2699         struct cifs_sb_info *cifs_sb;
2700         struct TCP_Server_Info *tcp_srv;
2701         struct cifs_ses *ses;
2702         struct cifs_tcon *tcon;
2703         struct tcon_link *tlink;
2704         bool dfs_super_cmp;
2705         int rc = 0;
2706
2707         spin_lock(&cifs_tcp_ses_lock);
2708         cifs_sb = CIFS_SB(sb);
2709         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2710         if (tlink == NULL) {
2711                 /* can not match superblock if tlink were ever null */
2712                 spin_unlock(&cifs_tcp_ses_lock);
2713                 return 0;
2714         }
2715         tcon = tlink_tcon(tlink);
2716         ses = tcon->ses;
2717         tcp_srv = ses->server;
2718
2719         dfs_super_cmp = IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && tcp_srv->origin_fullpath;
2720
2721         ctx = mnt_data->ctx;
2722
2723         spin_lock(&tcp_srv->srv_lock);
2724         spin_lock(&ses->ses_lock);
2725         spin_lock(&tcon->tc_lock);
2726         if (!match_server(tcp_srv, ctx, dfs_super_cmp) ||
2727             !match_session(ses, ctx) ||
2728             !match_tcon(tcon, ctx, dfs_super_cmp) ||
2729             !match_prepath(sb, mnt_data)) {
2730                 rc = 0;
2731                 goto out;
2732         }
2733
2734         rc = compare_mount_options(sb, mnt_data);
2735 out:
2736         spin_unlock(&tcon->tc_lock);
2737         spin_unlock(&ses->ses_lock);
2738         spin_unlock(&tcp_srv->srv_lock);
2739
2740         spin_unlock(&cifs_tcp_ses_lock);
2741         cifs_put_tlink(tlink);
2742         return rc;
2743 }
2744
2745 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2746 static struct lock_class_key cifs_key[2];
2747 static struct lock_class_key cifs_slock_key[2];
2748
2749 static inline void
2750 cifs_reclassify_socket4(struct socket *sock)
2751 {
2752         struct sock *sk = sock->sk;
2753         BUG_ON(!sock_allow_reclassification(sk));
2754         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2755                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2756 }
2757
2758 static inline void
2759 cifs_reclassify_socket6(struct socket *sock)
2760 {
2761         struct sock *sk = sock->sk;
2762         BUG_ON(!sock_allow_reclassification(sk));
2763         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2764                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2765 }
2766 #else
2767 static inline void
2768 cifs_reclassify_socket4(struct socket *sock)
2769 {
2770 }
2771
2772 static inline void
2773 cifs_reclassify_socket6(struct socket *sock)
2774 {
2775 }
2776 #endif
2777
2778 /* See RFC1001 section 14 on representation of Netbios names */
2779 static void rfc1002mangle(char *target, char *source, unsigned int length)
2780 {
2781         unsigned int i, j;
2782
2783         for (i = 0, j = 0; i < (length); i++) {
2784                 /* mask a nibble at a time and encode */
2785                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2786                 target[j+1] = 'A' + (0x0F & source[i]);
2787                 j += 2;
2788         }
2789
2790 }
2791
2792 static int
2793 bind_socket(struct TCP_Server_Info *server)
2794 {
2795         int rc = 0;
2796         if (server->srcaddr.ss_family != AF_UNSPEC) {
2797                 /* Bind to the specified local IP address */
2798                 struct socket *socket = server->ssocket;
2799                 rc = socket->ops->bind(socket,
2800                                        (struct sockaddr *) &server->srcaddr,
2801                                        sizeof(server->srcaddr));
2802                 if (rc < 0) {
2803                         struct sockaddr_in *saddr4;
2804                         struct sockaddr_in6 *saddr6;
2805                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2806                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2807                         if (saddr6->sin6_family == AF_INET6)
2808                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2809                                          &saddr6->sin6_addr, rc);
2810                         else
2811                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2812                                          &saddr4->sin_addr.s_addr, rc);
2813                 }
2814         }
2815         return rc;
2816 }
2817
2818 static int
2819 ip_rfc1001_connect(struct TCP_Server_Info *server)
2820 {
2821         int rc = 0;
2822         /*
2823          * some servers require RFC1001 sessinit before sending
2824          * negprot - BB check reconnection in case where second
2825          * sessinit is sent but no second negprot
2826          */
2827         struct rfc1002_session_packet *ses_init_buf;
2828         unsigned int req_noscope_len;
2829         struct smb_hdr *smb_buf;
2830
2831         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2832                                GFP_KERNEL);
2833
2834         if (ses_init_buf) {
2835                 ses_init_buf->trailer.session_req.called_len = 32;
2836
2837                 if (server->server_RFC1001_name[0] != 0)
2838                         rfc1002mangle(ses_init_buf->trailer.
2839                                       session_req.called_name,
2840                                       server->server_RFC1001_name,
2841                                       RFC1001_NAME_LEN_WITH_NULL);
2842                 else
2843                         rfc1002mangle(ses_init_buf->trailer.
2844                                       session_req.called_name,
2845                                       DEFAULT_CIFS_CALLED_NAME,
2846                                       RFC1001_NAME_LEN_WITH_NULL);
2847
2848                 ses_init_buf->trailer.session_req.calling_len = 32;
2849
2850                 /*
2851                  * calling name ends in null (byte 16) from old smb
2852                  * convention.
2853                  */
2854                 if (server->workstation_RFC1001_name[0] != 0)
2855                         rfc1002mangle(ses_init_buf->trailer.
2856                                       session_req.calling_name,
2857                                       server->workstation_RFC1001_name,
2858                                       RFC1001_NAME_LEN_WITH_NULL);
2859                 else
2860                         rfc1002mangle(ses_init_buf->trailer.
2861                                       session_req.calling_name,
2862                                       "LINUX_CIFS_CLNT",
2863                                       RFC1001_NAME_LEN_WITH_NULL);
2864
2865                 ses_init_buf->trailer.session_req.scope1 = 0;
2866                 ses_init_buf->trailer.session_req.scope2 = 0;
2867                 smb_buf = (struct smb_hdr *)ses_init_buf;
2868
2869                 /* sizeof RFC1002_SESSION_REQUEST with no scopes */
2870                 req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
2871
2872                 /* == cpu_to_be32(0x81000044) */
2873                 smb_buf->smb_buf_length =
2874                         cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
2875                 rc = smb_send(server, smb_buf, 0x44);
2876                 kfree(ses_init_buf);
2877                 /*
2878                  * RFC1001 layer in at least one server
2879                  * requires very short break before negprot
2880                  * presumably because not expecting negprot
2881                  * to follow so fast.  This is a simple
2882                  * solution that works without
2883                  * complicating the code and causes no
2884                  * significant slowing down on mount
2885                  * for everyone else
2886                  */
2887                 usleep_range(1000, 2000);
2888         }
2889         /*
2890          * else the negprot may still work without this
2891          * even though malloc failed
2892          */
2893
2894         return rc;
2895 }
2896
2897 static int
2898 generic_ip_connect(struct TCP_Server_Info *server)
2899 {
2900         int rc = 0;
2901         __be16 sport;
2902         int slen, sfamily;
2903         struct socket *socket = server->ssocket;
2904         struct sockaddr *saddr;
2905
2906         saddr = (struct sockaddr *) &server->dstaddr;
2907
2908         if (server->dstaddr.ss_family == AF_INET6) {
2909                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2910
2911                 sport = ipv6->sin6_port;
2912                 slen = sizeof(struct sockaddr_in6);
2913                 sfamily = AF_INET6;
2914                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2915                                 ntohs(sport));
2916         } else {
2917                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2918
2919                 sport = ipv4->sin_port;
2920                 slen = sizeof(struct sockaddr_in);
2921                 sfamily = AF_INET;
2922                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2923                                 ntohs(sport));
2924         }
2925
2926         if (socket == NULL) {
2927                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2928                                    IPPROTO_TCP, &socket, 1);
2929                 if (rc < 0) {
2930                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2931                         server->ssocket = NULL;
2932                         return rc;
2933                 }
2934
2935                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2936                 cifs_dbg(FYI, "Socket created\n");
2937                 server->ssocket = socket;
2938                 socket->sk->sk_allocation = GFP_NOFS;
2939                 if (sfamily == AF_INET6)
2940                         cifs_reclassify_socket6(socket);
2941                 else
2942                         cifs_reclassify_socket4(socket);
2943         }
2944
2945         rc = bind_socket(server);
2946         if (rc < 0)
2947                 return rc;
2948
2949         /*
2950          * Eventually check for other socket options to change from
2951          * the default. sock_setsockopt not used because it expects
2952          * user space buffer
2953          */
2954         socket->sk->sk_rcvtimeo = 7 * HZ;
2955         socket->sk->sk_sndtimeo = 5 * HZ;
2956
2957         /* make the bufsizes depend on wsize/rsize and max requests */
2958         if (server->noautotune) {
2959                 if (socket->sk->sk_sndbuf < (200 * 1024))
2960                         socket->sk->sk_sndbuf = 200 * 1024;
2961                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2962                         socket->sk->sk_rcvbuf = 140 * 1024;
2963         }
2964
2965         if (server->tcp_nodelay)
2966                 tcp_sock_set_nodelay(socket->sk);
2967
2968         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2969                  socket->sk->sk_sndbuf,
2970                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2971
2972         rc = socket->ops->connect(socket, saddr, slen,
2973                                   server->noblockcnt ? O_NONBLOCK : 0);
2974         /*
2975          * When mounting SMB root file systems, we do not want to block in
2976          * connect. Otherwise bail out and then let cifs_reconnect() perform
2977          * reconnect failover - if possible.
2978          */
2979         if (server->noblockcnt && rc == -EINPROGRESS)
2980                 rc = 0;
2981         if (rc < 0) {
2982                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2983                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2984                 sock_release(socket);
2985                 server->ssocket = NULL;
2986                 return rc;
2987         }
2988         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2989         if (sport == htons(RFC1001_PORT))
2990                 rc = ip_rfc1001_connect(server);
2991
2992         return rc;
2993 }
2994
2995 static int
2996 ip_connect(struct TCP_Server_Info *server)
2997 {
2998         __be16 *sport;
2999         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3000         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3001
3002         if (server->dstaddr.ss_family == AF_INET6)
3003                 sport = &addr6->sin6_port;
3004         else
3005                 sport = &addr->sin_port;
3006
3007         if (*sport == 0) {
3008                 int rc;
3009
3010                 /* try with 445 port at first */
3011                 *sport = htons(CIFS_PORT);
3012
3013                 rc = generic_ip_connect(server);
3014                 if (rc >= 0)
3015                         return rc;
3016
3017                 /* if it failed, try with 139 port */
3018                 *sport = htons(RFC1001_PORT);
3019         }
3020
3021         return generic_ip_connect(server);
3022 }
3023
3024 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3025 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3026                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3027 {
3028         /*
3029          * If we are reconnecting then should we check to see if
3030          * any requested capabilities changed locally e.g. via
3031          * remount but we can not do much about it here
3032          * if they have (even if we could detect it by the following)
3033          * Perhaps we could add a backpointer to array of sb from tcon
3034          * or if we change to make all sb to same share the same
3035          * sb as NFS - then we only have one backpointer to sb.
3036          * What if we wanted to mount the server share twice once with
3037          * and once without posixacls or posix paths?
3038          */
3039         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3040
3041         if (ctx && ctx->no_linux_ext) {
3042                 tcon->fsUnixInfo.Capability = 0;
3043                 tcon->unix_ext = 0; /* Unix Extensions disabled */
3044                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3045                 return;
3046         } else if (ctx)
3047                 tcon->unix_ext = 1; /* Unix Extensions supported */
3048
3049         if (!tcon->unix_ext) {
3050                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3051                 return;
3052         }
3053
3054         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3055                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3056                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3057                 /*
3058                  * check for reconnect case in which we do not
3059                  * want to change the mount behavior if we can avoid it
3060                  */
3061                 if (ctx == NULL) {
3062                         /*
3063                          * turn off POSIX ACL and PATHNAMES if not set
3064                          * originally at mount time
3065                          */
3066                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3067                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3068                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3069                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3070                                         cifs_dbg(VFS, "POSIXPATH support change\n");
3071                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3072                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3073                                 cifs_dbg(VFS, "possible reconnect error\n");
3074                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
3075                         }
3076                 }
3077
3078                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3079                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
3080
3081                 cap &= CIFS_UNIX_CAP_MASK;
3082                 if (ctx && ctx->no_psx_acl)
3083                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3084                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3085                         cifs_dbg(FYI, "negotiated posix acl support\n");
3086                         if (cifs_sb)
3087                                 cifs_sb->mnt_cifs_flags |=
3088                                         CIFS_MOUNT_POSIXACL;
3089                 }
3090
3091                 if (ctx && ctx->posix_paths == 0)
3092                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3093                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3094                         cifs_dbg(FYI, "negotiate posix pathnames\n");
3095                         if (cifs_sb)
3096                                 cifs_sb->mnt_cifs_flags |=
3097                                         CIFS_MOUNT_POSIX_PATHS;
3098                 }
3099
3100                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3101 #ifdef CONFIG_CIFS_DEBUG2
3102                 if (cap & CIFS_UNIX_FCNTL_CAP)
3103                         cifs_dbg(FYI, "FCNTL cap\n");
3104                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3105                         cifs_dbg(FYI, "EXTATTR cap\n");
3106                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3107                         cifs_dbg(FYI, "POSIX path cap\n");
3108                 if (cap & CIFS_UNIX_XATTR_CAP)
3109                         cifs_dbg(FYI, "XATTR cap\n");
3110                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3111                         cifs_dbg(FYI, "POSIX ACL cap\n");
3112                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3113                         cifs_dbg(FYI, "very large read cap\n");
3114                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3115                         cifs_dbg(FYI, "very large write cap\n");
3116                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3117                         cifs_dbg(FYI, "transport encryption cap\n");
3118                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3119                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3120 #endif /* CIFS_DEBUG2 */
3121                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3122                         if (ctx == NULL)
3123                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3124                         else
3125                                 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");
3126
3127                 }
3128         }
3129 }
3130 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3131
3132 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3133 {
3134         struct smb3_fs_context *ctx = cifs_sb->ctx;
3135
3136         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3137
3138         spin_lock_init(&cifs_sb->tlink_tree_lock);
3139         cifs_sb->tlink_tree = RB_ROOT;
3140
3141         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3142                  ctx->file_mode, ctx->dir_mode);
3143
3144         /* this is needed for ASCII cp to Unicode converts */
3145         if (ctx->iocharset == NULL) {
3146                 /* load_nls_default cannot return null */
3147                 cifs_sb->local_nls = load_nls_default();
3148         } else {
3149                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3150                 if (cifs_sb->local_nls == NULL) {
3151                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3152                                  ctx->iocharset);
3153                         return -ELIBACC;
3154                 }
3155         }
3156         ctx->local_nls = cifs_sb->local_nls;
3157
3158         smb3_update_mnt_flags(cifs_sb);
3159
3160         if (ctx->direct_io)
3161                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3162         if (ctx->cache_ro) {
3163                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3164                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3165         } else if (ctx->cache_rw) {
3166                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3167                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3168                                             CIFS_MOUNT_RW_CACHE);
3169         }
3170
3171         if ((ctx->cifs_acl) && (ctx->dynperm))
3172                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3173
3174         if (ctx->prepath) {
3175                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3176                 if (cifs_sb->prepath == NULL)
3177                         return -ENOMEM;
3178                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3179         }
3180
3181         return 0;
3182 }
3183
3184 /* Release all succeed connections */
3185 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3186 {
3187         int rc = 0;
3188
3189         if (mnt_ctx->tcon)
3190                 cifs_put_tcon(mnt_ctx->tcon);
3191         else if (mnt_ctx->ses)
3192                 cifs_put_smb_ses(mnt_ctx->ses);
3193         else if (mnt_ctx->server)
3194                 cifs_put_tcp_session(mnt_ctx->server, 0);
3195         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3196         free_xid(mnt_ctx->xid);
3197 }
3198
3199 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3200 {
3201         struct TCP_Server_Info *server = NULL;
3202         struct smb3_fs_context *ctx;
3203         struct cifs_ses *ses = NULL;
3204         unsigned int xid;
3205         int rc = 0;
3206
3207         xid = get_xid();
3208
3209         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3210                 rc = -EINVAL;
3211                 goto out;
3212         }
3213         ctx = mnt_ctx->fs_ctx;
3214
3215         /* get a reference to a tcp session */
3216         server = cifs_get_tcp_session(ctx, NULL);
3217         if (IS_ERR(server)) {
3218                 rc = PTR_ERR(server);
3219                 server = NULL;
3220                 goto out;
3221         }
3222
3223         /* get a reference to a SMB session */
3224         ses = cifs_get_smb_ses(server, ctx);
3225         if (IS_ERR(ses)) {
3226                 rc = PTR_ERR(ses);
3227                 ses = NULL;
3228                 goto out;
3229         }
3230
3231         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3232                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3233                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3234                 rc = -EOPNOTSUPP;
3235         }
3236
3237 out:
3238         mnt_ctx->xid = xid;
3239         mnt_ctx->server = server;
3240         mnt_ctx->ses = ses;
3241         mnt_ctx->tcon = NULL;
3242
3243         return rc;
3244 }
3245
3246 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3247 {
3248         struct TCP_Server_Info *server;
3249         struct cifs_sb_info *cifs_sb;
3250         struct smb3_fs_context *ctx;
3251         struct cifs_tcon *tcon = NULL;
3252         int rc = 0;
3253
3254         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3255                          !mnt_ctx->cifs_sb)) {
3256                 rc = -EINVAL;
3257                 goto out;
3258         }
3259         server = mnt_ctx->server;
3260         ctx = mnt_ctx->fs_ctx;
3261         cifs_sb = mnt_ctx->cifs_sb;
3262
3263         /* search for existing tcon to this server share */
3264         tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3265         if (IS_ERR(tcon)) {
3266                 rc = PTR_ERR(tcon);
3267                 tcon = NULL;
3268                 goto out;
3269         }
3270
3271         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3272         if (tcon->posix_extensions)
3273                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3274
3275 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3276         /* tell server which Unix caps we support */
3277         if (cap_unix(tcon->ses)) {
3278                 /*
3279                  * reset of caps checks mount to see if unix extensions disabled
3280                  * for just this mount.
3281                  */
3282                 reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3283                 spin_lock(&tcon->ses->server->srv_lock);
3284                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3285                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3286                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3287                         spin_unlock(&tcon->ses->server->srv_lock);
3288                         rc = -EACCES;
3289                         goto out;
3290                 }
3291                 spin_unlock(&tcon->ses->server->srv_lock);
3292         } else
3293 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3294                 tcon->unix_ext = 0; /* server does not support them */
3295
3296         /* do not care if a following call succeed - informational */
3297         if (!tcon->pipe && server->ops->qfs_tcon) {
3298                 server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3299                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3300                         if (tcon->fsDevInfo.DeviceCharacteristics &
3301                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3302                                 cifs_dbg(VFS, "mounted to read only share\n");
3303                         else if ((cifs_sb->mnt_cifs_flags &
3304                                   CIFS_MOUNT_RW_CACHE) == 0)
3305                                 cifs_dbg(VFS, "read only mount of RW share\n");
3306                         /* no need to log a RW mount of a typical RW share */
3307                 }
3308         }
3309
3310         /*
3311          * Clamp the rsize/wsize mount arguments if they are too big for the server
3312          * and set the rsize/wsize to the negotiated values if not passed in by
3313          * the user on mount
3314          */
3315         if ((cifs_sb->ctx->wsize == 0) ||
3316             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3317                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3318         if ((cifs_sb->ctx->rsize == 0) ||
3319             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3320                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3321
3322         /*
3323          * The cookie is initialized from volume info returned above.
3324          * Inside cifs_fscache_get_super_cookie it checks
3325          * that we do not get super cookie twice.
3326          */
3327         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3328                 cifs_fscache_get_super_cookie(tcon);
3329
3330 out:
3331         mnt_ctx->tcon = tcon;
3332         return rc;
3333 }
3334
3335 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3336                              struct cifs_tcon *tcon)
3337 {
3338         struct tcon_link *tlink;
3339
3340         /* hang the tcon off of the superblock */
3341         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3342         if (tlink == NULL)
3343                 return -ENOMEM;
3344
3345         tlink->tl_uid = ses->linux_uid;
3346         tlink->tl_tcon = tcon;
3347         tlink->tl_time = jiffies;
3348         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3349         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3350
3351         cifs_sb->master_tlink = tlink;
3352         spin_lock(&cifs_sb->tlink_tree_lock);
3353         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3354         spin_unlock(&cifs_sb->tlink_tree_lock);
3355
3356         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3357                                 TLINK_IDLE_EXPIRE);
3358         return 0;
3359 }
3360
3361 static int
3362 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3363                                         unsigned int xid,
3364                                         struct cifs_tcon *tcon,
3365                                         struct cifs_sb_info *cifs_sb,
3366                                         char *full_path,
3367                                         int added_treename)
3368 {
3369         int rc;
3370         char *s;
3371         char sep, tmp;
3372         int skip = added_treename ? 1 : 0;
3373
3374         sep = CIFS_DIR_SEP(cifs_sb);
3375         s = full_path;
3376
3377         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3378         while (rc == 0) {
3379                 /* skip separators */
3380                 while (*s == sep)
3381                         s++;
3382                 if (!*s)
3383                         break;
3384                 /* next separator */
3385                 while (*s && *s != sep)
3386                         s++;
3387                 /*
3388                  * if the treename is added, we then have to skip the first
3389                  * part within the separators
3390                  */
3391                 if (skip) {
3392                         skip = 0;
3393                         continue;
3394                 }
3395                 /*
3396                  * temporarily null-terminate the path at the end of
3397                  * the current component
3398                  */
3399                 tmp = *s;
3400                 *s = 0;
3401                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3402                                                      full_path);
3403                 *s = tmp;
3404         }
3405         return rc;
3406 }
3407
3408 /*
3409  * Check if path is remote (i.e. a DFS share).
3410  *
3411  * Return -EREMOTE if it is, otherwise 0 or -errno.
3412  */
3413 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3414 {
3415         int rc;
3416         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3417         struct TCP_Server_Info *server = mnt_ctx->server;
3418         unsigned int xid = mnt_ctx->xid;
3419         struct cifs_tcon *tcon = mnt_ctx->tcon;
3420         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3421         char *full_path;
3422
3423         if (!server->ops->is_path_accessible)
3424                 return -EOPNOTSUPP;
3425
3426         /*
3427          * cifs_build_path_to_root works only when we have a valid tcon
3428          */
3429         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3430                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3431         if (full_path == NULL)
3432                 return -ENOMEM;
3433
3434         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3435
3436         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3437                                              full_path);
3438         if (rc != 0 && rc != -EREMOTE)
3439                 goto out;
3440
3441         if (rc != -EREMOTE) {
3442                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3443                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3444                 if (rc != 0) {
3445                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3446                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3447                         rc = 0;
3448                 }
3449         }
3450
3451 out:
3452         kfree(full_path);
3453         return rc;
3454 }
3455
3456 #ifdef CONFIG_CIFS_DFS_UPCALL
3457 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3458 {
3459         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3460         bool isdfs;
3461         int rc;
3462
3463         uuid_gen(&mnt_ctx.mount_id);
3464         rc = dfs_mount_share(&mnt_ctx, &isdfs);
3465         if (rc)
3466                 goto error;
3467         if (!isdfs)
3468                 goto out;
3469
3470         /*
3471          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3472          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3473          */
3474         cifs_autodisable_serverino(cifs_sb);
3475         /*
3476          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3477          * that have different prefix paths.
3478          */
3479         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3480         kfree(cifs_sb->prepath);
3481         cifs_sb->prepath = ctx->prepath;
3482         ctx->prepath = NULL;
3483         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3484
3485 out:
3486         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3487         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3488         if (rc)
3489                 goto error;
3490
3491         free_xid(mnt_ctx.xid);
3492         return rc;
3493
3494 error:
3495         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3496         kfree(mnt_ctx.origin_fullpath);
3497         kfree(mnt_ctx.leaf_fullpath);
3498         cifs_mount_put_conns(&mnt_ctx);
3499         return rc;
3500 }
3501 #else
3502 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3503 {
3504         int rc = 0;
3505         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3506
3507         rc = cifs_mount_get_session(&mnt_ctx);
3508         if (rc)
3509                 goto error;
3510
3511         rc = cifs_mount_get_tcon(&mnt_ctx);
3512         if (rc)
3513                 goto error;
3514
3515         rc = cifs_is_path_remote(&mnt_ctx);
3516         if (rc == -EREMOTE)
3517                 rc = -EOPNOTSUPP;
3518         if (rc)
3519                 goto error;
3520
3521         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3522         if (rc)
3523                 goto error;
3524
3525         free_xid(mnt_ctx.xid);
3526         return rc;
3527
3528 error:
3529         cifs_mount_put_conns(&mnt_ctx);
3530         return rc;
3531 }
3532 #endif
3533
3534 /*
3535  * Issue a TREE_CONNECT request.
3536  */
3537 int
3538 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3539          const char *tree, struct cifs_tcon *tcon,
3540          const struct nls_table *nls_codepage)
3541 {
3542         struct smb_hdr *smb_buffer;
3543         struct smb_hdr *smb_buffer_response;
3544         TCONX_REQ *pSMB;
3545         TCONX_RSP *pSMBr;
3546         unsigned char *bcc_ptr;
3547         int rc = 0;
3548         int length;
3549         __u16 bytes_left, count;
3550
3551         if (ses == NULL)
3552                 return -EIO;
3553
3554         smb_buffer = cifs_buf_get();
3555         if (smb_buffer == NULL)
3556                 return -ENOMEM;
3557
3558         smb_buffer_response = smb_buffer;
3559
3560         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3561                         NULL /*no tid */ , 4 /*wct */ );
3562
3563         smb_buffer->Mid = get_next_mid(ses->server);
3564         smb_buffer->Uid = ses->Suid;
3565         pSMB = (TCONX_REQ *) smb_buffer;
3566         pSMBr = (TCONX_RSP *) smb_buffer_response;
3567
3568         pSMB->AndXCommand = 0xFF;
3569         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3570         bcc_ptr = &pSMB->Password[0];
3571
3572         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3573         *bcc_ptr = 0; /* password is null byte */
3574         bcc_ptr++;              /* skip password */
3575         /* already aligned so no need to do it below */
3576
3577         if (ses->server->sign)
3578                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3579
3580         if (ses->capabilities & CAP_STATUS32) {
3581                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3582         }
3583         if (ses->capabilities & CAP_DFS) {
3584                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3585         }
3586         if (ses->capabilities & CAP_UNICODE) {
3587                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3588                 length =
3589                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3590                         6 /* max utf8 char length in bytes */ *
3591                         (/* server len*/ + 256 /* share len */), nls_codepage);
3592                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3593                 bcc_ptr += 2;   /* skip trailing null */
3594         } else {                /* ASCII */
3595                 strcpy(bcc_ptr, tree);
3596                 bcc_ptr += strlen(tree) + 1;
3597         }
3598         strcpy(bcc_ptr, "?????");
3599         bcc_ptr += strlen("?????");
3600         bcc_ptr += 1;
3601         count = bcc_ptr - &pSMB->Password[0];
3602         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3603         pSMB->ByteCount = cpu_to_le16(count);
3604
3605         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3606                          0);
3607
3608         /* above now done in SendReceive */
3609         if (rc == 0) {
3610                 bool is_unicode;
3611
3612                 tcon->tid = smb_buffer_response->Tid;
3613                 bcc_ptr = pByteArea(smb_buffer_response);
3614                 bytes_left = get_bcc(smb_buffer_response);
3615                 length = strnlen(bcc_ptr, bytes_left - 2);
3616                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3617                         is_unicode = true;
3618                 else
3619                         is_unicode = false;
3620
3621
3622                 /* skip service field (NB: this field is always ASCII) */
3623                 if (length == 3) {
3624                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3625                             (bcc_ptr[2] == 'C')) {
3626                                 cifs_dbg(FYI, "IPC connection\n");
3627                                 tcon->ipc = true;
3628                                 tcon->pipe = true;
3629                         }
3630                 } else if (length == 2) {
3631                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3632                                 /* the most common case */
3633                                 cifs_dbg(FYI, "disk share connection\n");
3634                         }
3635                 }
3636                 bcc_ptr += length + 1;
3637                 bytes_left -= (length + 1);
3638                 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3639
3640                 /* mostly informational -- no need to fail on error here */
3641                 kfree(tcon->nativeFileSystem);
3642                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3643                                                       bytes_left, is_unicode,
3644                                                       nls_codepage);
3645
3646                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3647
3648                 if ((smb_buffer_response->WordCount == 3) ||
3649                          (smb_buffer_response->WordCount == 7))
3650                         /* field is in same location */
3651                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3652                 else
3653                         tcon->Flags = 0;
3654                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3655         }
3656
3657         cifs_buf_release(smb_buffer);
3658         return rc;
3659 }
3660
3661 static void delayed_free(struct rcu_head *p)
3662 {
3663         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3664
3665         unload_nls(cifs_sb->local_nls);
3666         smb3_cleanup_fs_context(cifs_sb->ctx);
3667         kfree(cifs_sb);
3668 }
3669
3670 void
3671 cifs_umount(struct cifs_sb_info *cifs_sb)
3672 {
3673         struct rb_root *root = &cifs_sb->tlink_tree;
3674         struct rb_node *node;
3675         struct tcon_link *tlink;
3676
3677         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3678
3679         spin_lock(&cifs_sb->tlink_tree_lock);
3680         while ((node = rb_first(root))) {
3681                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3682                 cifs_get_tlink(tlink);
3683                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3684                 rb_erase(node, root);
3685
3686                 spin_unlock(&cifs_sb->tlink_tree_lock);
3687                 cifs_put_tlink(tlink);
3688                 spin_lock(&cifs_sb->tlink_tree_lock);
3689         }
3690         spin_unlock(&cifs_sb->tlink_tree_lock);
3691
3692         kfree(cifs_sb->prepath);
3693 #ifdef CONFIG_CIFS_DFS_UPCALL
3694         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3695 #endif
3696         call_rcu(&cifs_sb->rcu, delayed_free);
3697 }
3698
3699 int
3700 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3701                         struct TCP_Server_Info *server)
3702 {
3703         int rc = 0;
3704
3705         if (!server->ops->need_neg || !server->ops->negotiate)
3706                 return -ENOSYS;
3707
3708         /* only send once per connect */
3709         spin_lock(&server->srv_lock);
3710         if (!server->ops->need_neg(server) ||
3711             server->tcpStatus != CifsNeedNegotiate) {
3712                 spin_unlock(&server->srv_lock);
3713                 return 0;
3714         }
3715         server->tcpStatus = CifsInNegotiate;
3716         spin_unlock(&server->srv_lock);
3717
3718         rc = server->ops->negotiate(xid, ses, server);
3719         if (rc == 0) {
3720                 spin_lock(&server->srv_lock);
3721                 if (server->tcpStatus == CifsInNegotiate)
3722                         server->tcpStatus = CifsGood;
3723                 else
3724                         rc = -EHOSTDOWN;
3725                 spin_unlock(&server->srv_lock);
3726         } else {
3727                 spin_lock(&server->srv_lock);
3728                 if (server->tcpStatus == CifsInNegotiate)
3729                         server->tcpStatus = CifsNeedNegotiate;
3730                 spin_unlock(&server->srv_lock);
3731         }
3732
3733         return rc;
3734 }
3735
3736 int
3737 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3738                    struct TCP_Server_Info *server,
3739                    struct nls_table *nls_info)
3740 {
3741         int rc = -ENOSYS;
3742         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3743         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3744         bool is_binding = false;
3745
3746         spin_lock(&ses->ses_lock);
3747         if (server->dstaddr.ss_family == AF_INET6)
3748                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3749         else
3750                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3751
3752         if (ses->ses_status != SES_GOOD &&
3753             ses->ses_status != SES_NEW &&
3754             ses->ses_status != SES_NEED_RECON) {
3755                 spin_unlock(&ses->ses_lock);
3756                 return 0;
3757         }
3758
3759         /* only send once per connect */
3760         spin_lock(&ses->chan_lock);
3761         if (CIFS_ALL_CHANS_GOOD(ses) ||
3762             cifs_chan_in_reconnect(ses, server)) {
3763                 spin_unlock(&ses->chan_lock);
3764                 spin_unlock(&ses->ses_lock);
3765                 return 0;
3766         }
3767         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3768         cifs_chan_set_in_reconnect(ses, server);
3769         spin_unlock(&ses->chan_lock);
3770
3771         if (!is_binding)
3772                 ses->ses_status = SES_IN_SETUP;
3773         spin_unlock(&ses->ses_lock);
3774
3775         if (!is_binding) {
3776                 ses->capabilities = server->capabilities;
3777                 if (!linuxExtEnabled)
3778                         ses->capabilities &= (~server->vals->cap_unix);
3779
3780                 if (ses->auth_key.response) {
3781                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3782                                  ses->auth_key.response);
3783                         kfree_sensitive(ses->auth_key.response);
3784                         ses->auth_key.response = NULL;
3785                         ses->auth_key.len = 0;
3786                 }
3787         }
3788
3789         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3790                  server->sec_mode, server->capabilities, server->timeAdj);
3791
3792         if (server->ops->sess_setup)
3793                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
3794
3795         if (rc) {
3796                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3797                 spin_lock(&ses->ses_lock);
3798                 if (ses->ses_status == SES_IN_SETUP)
3799                         ses->ses_status = SES_NEED_RECON;
3800                 spin_lock(&ses->chan_lock);
3801                 cifs_chan_clear_in_reconnect(ses, server);
3802                 spin_unlock(&ses->chan_lock);
3803                 spin_unlock(&ses->ses_lock);
3804         } else {
3805                 spin_lock(&ses->ses_lock);
3806                 if (ses->ses_status == SES_IN_SETUP)
3807                         ses->ses_status = SES_GOOD;
3808                 spin_lock(&ses->chan_lock);
3809                 cifs_chan_clear_in_reconnect(ses, server);
3810                 cifs_chan_clear_need_reconnect(ses, server);
3811                 spin_unlock(&ses->chan_lock);
3812                 spin_unlock(&ses->ses_lock);
3813         }
3814
3815         return rc;
3816 }
3817
3818 static int
3819 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3820 {
3821         ctx->sectype = ses->sectype;
3822
3823         /* krb5 is special, since we don't need username or pw */
3824         if (ctx->sectype == Kerberos)
3825                 return 0;
3826
3827         return cifs_set_cifscreds(ctx, ses);
3828 }
3829
3830 static struct cifs_tcon *
3831 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3832 {
3833         int rc;
3834         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3835         struct cifs_ses *ses;
3836         struct cifs_tcon *tcon = NULL;
3837         struct smb3_fs_context *ctx;
3838
3839         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3840         if (ctx == NULL)
3841                 return ERR_PTR(-ENOMEM);
3842
3843         ctx->local_nls = cifs_sb->local_nls;
3844         ctx->linux_uid = fsuid;
3845         ctx->cred_uid = fsuid;
3846         ctx->UNC = master_tcon->tree_name;
3847         ctx->retry = master_tcon->retry;
3848         ctx->nocase = master_tcon->nocase;
3849         ctx->nohandlecache = master_tcon->nohandlecache;
3850         ctx->local_lease = master_tcon->local_lease;
3851         ctx->no_lease = master_tcon->no_lease;
3852         ctx->resilient = master_tcon->use_resilient;
3853         ctx->persistent = master_tcon->use_persistent;
3854         ctx->handle_timeout = master_tcon->handle_timeout;
3855         ctx->no_linux_ext = !master_tcon->unix_ext;
3856         ctx->linux_ext = master_tcon->posix_extensions;
3857         ctx->sectype = master_tcon->ses->sectype;
3858         ctx->sign = master_tcon->ses->sign;
3859         ctx->seal = master_tcon->seal;
3860         ctx->witness = master_tcon->use_witness;
3861
3862         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3863         if (rc) {
3864                 tcon = ERR_PTR(rc);
3865                 goto out;
3866         }
3867
3868         /* get a reference for the same TCP session */
3869         spin_lock(&cifs_tcp_ses_lock);
3870         ++master_tcon->ses->server->srv_count;
3871         spin_unlock(&cifs_tcp_ses_lock);
3872
3873         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3874         if (IS_ERR(ses)) {
3875                 tcon = (struct cifs_tcon *)ses;
3876                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3877                 goto out;
3878         }
3879
3880         tcon = cifs_get_tcon(ses, ctx);
3881         if (IS_ERR(tcon)) {
3882                 cifs_put_smb_ses(ses);
3883                 goto out;
3884         }
3885
3886 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3887         if (cap_unix(ses))
3888                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3889 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3890
3891 out:
3892         kfree(ctx->username);
3893         kfree_sensitive(ctx->password);
3894         kfree(ctx);
3895
3896         return tcon;
3897 }
3898
3899 struct cifs_tcon *
3900 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3901 {
3902         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3903 }
3904
3905 /* find and return a tlink with given uid */
3906 static struct tcon_link *
3907 tlink_rb_search(struct rb_root *root, kuid_t uid)
3908 {
3909         struct rb_node *node = root->rb_node;
3910         struct tcon_link *tlink;
3911
3912         while (node) {
3913                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3914
3915                 if (uid_gt(tlink->tl_uid, uid))
3916                         node = node->rb_left;
3917                 else if (uid_lt(tlink->tl_uid, uid))
3918                         node = node->rb_right;
3919                 else
3920                         return tlink;
3921         }
3922         return NULL;
3923 }
3924
3925 /* insert a tcon_link into the tree */
3926 static void
3927 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3928 {
3929         struct rb_node **new = &(root->rb_node), *parent = NULL;
3930         struct tcon_link *tlink;
3931
3932         while (*new) {
3933                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3934                 parent = *new;
3935
3936                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3937                         new = &((*new)->rb_left);
3938                 else
3939                         new = &((*new)->rb_right);
3940         }
3941
3942         rb_link_node(&new_tlink->tl_rbnode, parent, new);
3943         rb_insert_color(&new_tlink->tl_rbnode, root);
3944 }
3945
3946 /*
3947  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3948  * current task.
3949  *
3950  * If the superblock doesn't refer to a multiuser mount, then just return
3951  * the master tcon for the mount.
3952  *
3953  * First, search the rbtree for an existing tcon for this fsuid. If one
3954  * exists, then check to see if it's pending construction. If it is then wait
3955  * for construction to complete. Once it's no longer pending, check to see if
3956  * it failed and either return an error or retry construction, depending on
3957  * the timeout.
3958  *
3959  * If one doesn't exist then insert a new tcon_link struct into the tree and
3960  * try to construct a new one.
3961  */
3962 struct tcon_link *
3963 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3964 {
3965         int ret;
3966         kuid_t fsuid = current_fsuid();
3967         struct tcon_link *tlink, *newtlink;
3968
3969         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3970                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3971
3972         spin_lock(&cifs_sb->tlink_tree_lock);
3973         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3974         if (tlink)
3975                 cifs_get_tlink(tlink);
3976         spin_unlock(&cifs_sb->tlink_tree_lock);
3977
3978         if (tlink == NULL) {
3979                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3980                 if (newtlink == NULL)
3981                         return ERR_PTR(-ENOMEM);
3982                 newtlink->tl_uid = fsuid;
3983                 newtlink->tl_tcon = ERR_PTR(-EACCES);
3984                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
3985                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
3986                 cifs_get_tlink(newtlink);
3987
3988                 spin_lock(&cifs_sb->tlink_tree_lock);
3989                 /* was one inserted after previous search? */
3990                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3991                 if (tlink) {
3992                         cifs_get_tlink(tlink);
3993                         spin_unlock(&cifs_sb->tlink_tree_lock);
3994                         kfree(newtlink);
3995                         goto wait_for_construction;
3996                 }
3997                 tlink = newtlink;
3998                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3999                 spin_unlock(&cifs_sb->tlink_tree_lock);
4000         } else {
4001 wait_for_construction:
4002                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4003                                   TASK_INTERRUPTIBLE);
4004                 if (ret) {
4005                         cifs_put_tlink(tlink);
4006                         return ERR_PTR(-ERESTARTSYS);
4007                 }
4008
4009                 /* if it's good, return it */
4010                 if (!IS_ERR(tlink->tl_tcon))
4011                         return tlink;
4012
4013                 /* return error if we tried this already recently */
4014                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4015                         cifs_put_tlink(tlink);
4016                         return ERR_PTR(-EACCES);
4017                 }
4018
4019                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4020                         goto wait_for_construction;
4021         }
4022
4023         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4024         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4025         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4026
4027         if (IS_ERR(tlink->tl_tcon)) {
4028                 cifs_put_tlink(tlink);
4029                 return ERR_PTR(-EACCES);
4030         }
4031
4032         return tlink;
4033 }
4034
4035 /*
4036  * periodic workqueue job that scans tcon_tree for a superblock and closes
4037  * out tcons.
4038  */
4039 static void
4040 cifs_prune_tlinks(struct work_struct *work)
4041 {
4042         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4043                                                     prune_tlinks.work);
4044         struct rb_root *root = &cifs_sb->tlink_tree;
4045         struct rb_node *node;
4046         struct rb_node *tmp;
4047         struct tcon_link *tlink;
4048
4049         /*
4050          * Because we drop the spinlock in the loop in order to put the tlink
4051          * it's not guarded against removal of links from the tree. The only
4052          * places that remove entries from the tree are this function and
4053          * umounts. Because this function is non-reentrant and is canceled
4054          * before umount can proceed, this is safe.
4055          */
4056         spin_lock(&cifs_sb->tlink_tree_lock);
4057         node = rb_first(root);
4058         while (node != NULL) {
4059                 tmp = node;
4060                 node = rb_next(tmp);
4061                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4062
4063                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4064                     atomic_read(&tlink->tl_count) != 0 ||
4065                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4066                         continue;
4067
4068                 cifs_get_tlink(tlink);
4069                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4070                 rb_erase(tmp, root);
4071
4072                 spin_unlock(&cifs_sb->tlink_tree_lock);
4073                 cifs_put_tlink(tlink);
4074                 spin_lock(&cifs_sb->tlink_tree_lock);
4075         }
4076         spin_unlock(&cifs_sb->tlink_tree_lock);
4077
4078         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4079                                 TLINK_IDLE_EXPIRE);
4080 }
4081
4082 #ifdef CONFIG_CIFS_DFS_UPCALL
4083 /* Update dfs referral path of superblock */
4084 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4085                                   const char *target)
4086 {
4087         int rc = 0;
4088         size_t len = strlen(target);
4089         char *refpath, *npath;
4090
4091         if (unlikely(len < 2 || *target != '\\'))
4092                 return -EINVAL;
4093
4094         if (target[1] == '\\') {
4095                 len += 1;
4096                 refpath = kmalloc(len, GFP_KERNEL);
4097                 if (!refpath)
4098                         return -ENOMEM;
4099
4100                 scnprintf(refpath, len, "%s", target);
4101         } else {
4102                 len += sizeof("\\");
4103                 refpath = kmalloc(len, GFP_KERNEL);
4104                 if (!refpath)
4105                         return -ENOMEM;
4106
4107                 scnprintf(refpath, len, "\\%s", target);
4108         }
4109
4110         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4111         kfree(refpath);
4112
4113         if (IS_ERR(npath)) {
4114                 rc = PTR_ERR(npath);
4115         } else {
4116                 mutex_lock(&server->refpath_lock);
4117                 kfree(server->leaf_fullpath);
4118                 server->leaf_fullpath = npath;
4119                 mutex_unlock(&server->refpath_lock);
4120                 server->current_fullpath = server->leaf_fullpath;
4121         }
4122         return rc;
4123 }
4124
4125 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4126                                        size_t tcp_host_len, char *share, bool *target_match)
4127 {
4128         int rc = 0;
4129         const char *dfs_host;
4130         size_t dfs_host_len;
4131
4132         *target_match = true;
4133         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4134
4135         /* Check if hostnames or addresses match */
4136         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4137                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4138                          dfs_host, (int)tcp_host_len, tcp_host);
4139                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4140                 if (rc)
4141                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4142         }
4143         return rc;
4144 }
4145
4146 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4147                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4148                                      struct dfs_cache_tgt_list *tl)
4149 {
4150         int rc;
4151         struct TCP_Server_Info *server = tcon->ses->server;
4152         const struct smb_version_operations *ops = server->ops;
4153         struct cifs_ses *root_ses = CIFS_DFS_ROOT_SES(tcon->ses);
4154         struct cifs_tcon *ipc = root_ses->tcon_ipc;
4155         char *share = NULL, *prefix = NULL;
4156         const char *tcp_host;
4157         size_t tcp_host_len;
4158         struct dfs_cache_tgt_iterator *tit;
4159         bool target_match;
4160
4161         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4162
4163         tit = dfs_cache_get_tgt_iterator(tl);
4164         if (!tit) {
4165                 rc = -ENOENT;
4166                 goto out;
4167         }
4168
4169         /* Try to tree connect to all dfs targets */
4170         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4171                 const char *target = dfs_cache_get_tgt_name(tit);
4172                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4173
4174                 kfree(share);
4175                 kfree(prefix);
4176                 share = prefix = NULL;
4177
4178                 /* Check if share matches with tcp ses */
4179                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4180                 if (rc) {
4181                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4182                         break;
4183                 }
4184
4185                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4186                                                  &target_match);
4187                 if (rc)
4188                         break;
4189                 if (!target_match) {
4190                         rc = -EHOSTUNREACH;
4191                         continue;
4192                 }
4193
4194                 if (ipc->need_reconnect) {
4195                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4196                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4197                         if (rc)
4198                                 break;
4199                 }
4200
4201                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4202                 if (!islink) {
4203                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4204                         break;
4205                 }
4206                 /*
4207                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4208                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4209                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4210                  * newly resolved target.
4211                  */
4212                 if (dfs_cache_find(xid, root_ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4213                                    NULL, &ntl)) {
4214                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4215                         if (rc)
4216                                 continue;
4217                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4218                         if (!rc)
4219                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4220                 } else {
4221                         /* Target is another dfs share */
4222                         rc = update_server_fullpath(server, cifs_sb, target);
4223                         dfs_cache_free_tgts(tl);
4224
4225                         if (!rc) {
4226                                 rc = -EREMOTE;
4227                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4228                         } else
4229                                 dfs_cache_free_tgts(&ntl);
4230                 }
4231                 break;
4232         }
4233
4234 out:
4235         kfree(share);
4236         kfree(prefix);
4237
4238         return rc;
4239 }
4240
4241 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4242                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4243                                    struct dfs_cache_tgt_list *tl)
4244 {
4245         int rc;
4246         int num_links = 0;
4247         struct TCP_Server_Info *server = tcon->ses->server;
4248
4249         do {
4250                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4251                 if (!rc || rc != -EREMOTE)
4252                         break;
4253         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4254         /*
4255          * If we couldn't tree connect to any targets from last referral path, then retry from
4256          * original referral path.
4257          */
4258         if (rc && server->current_fullpath != server->origin_fullpath) {
4259                 server->current_fullpath = server->origin_fullpath;
4260                 cifs_signal_cifsd_for_reconnect(server, true);
4261         }
4262
4263         dfs_cache_free_tgts(tl);
4264         return rc;
4265 }
4266
4267 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4268 {
4269         int rc;
4270         struct TCP_Server_Info *server = tcon->ses->server;
4271         const struct smb_version_operations *ops = server->ops;
4272         struct super_block *sb = NULL;
4273         struct cifs_sb_info *cifs_sb;
4274         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4275         char *tree;
4276         struct dfs_info3_param ref = {0};
4277
4278         /* only send once per connect */
4279         spin_lock(&tcon->tc_lock);
4280         if (tcon->ses->ses_status != SES_GOOD ||
4281             (tcon->status != TID_NEW &&
4282             tcon->status != TID_NEED_TCON)) {
4283                 spin_unlock(&tcon->tc_lock);
4284                 return 0;
4285         }
4286         tcon->status = TID_IN_TCON;
4287         spin_unlock(&tcon->tc_lock);
4288
4289         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4290         if (!tree) {
4291                 rc = -ENOMEM;
4292                 goto out;
4293         }
4294
4295         if (tcon->ipc) {
4296                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4297                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4298                 goto out;
4299         }
4300
4301         sb = cifs_get_tcp_super(server);
4302         if (IS_ERR(sb)) {
4303                 rc = PTR_ERR(sb);
4304                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4305                 goto out;
4306         }
4307
4308         cifs_sb = CIFS_SB(sb);
4309
4310         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4311         if (!server->current_fullpath ||
4312             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4313                 rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, cifs_sb->local_nls);
4314                 goto out;
4315         }
4316
4317         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4318                                      &tl);
4319         free_dfs_info_param(&ref);
4320
4321 out:
4322         kfree(tree);
4323         cifs_put_tcp_super(sb);
4324
4325         if (rc) {
4326                 spin_lock(&tcon->tc_lock);
4327                 if (tcon->status == TID_IN_TCON)
4328                         tcon->status = TID_NEED_TCON;
4329                 spin_unlock(&tcon->tc_lock);
4330         } else {
4331                 spin_lock(&tcon->tc_lock);
4332                 if (tcon->status == TID_IN_TCON)
4333                         tcon->status = TID_GOOD;
4334                 spin_unlock(&tcon->tc_lock);
4335                 tcon->need_reconnect = false;
4336         }
4337
4338         return rc;
4339 }
4340 #else
4341 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4342 {
4343         int rc;
4344         const struct smb_version_operations *ops = tcon->ses->server->ops;
4345
4346         /* only send once per connect */
4347         spin_lock(&tcon->tc_lock);
4348         if (tcon->ses->ses_status != SES_GOOD ||
4349             (tcon->status != TID_NEW &&
4350             tcon->status != TID_NEED_TCON)) {
4351                 spin_unlock(&tcon->tc_lock);
4352                 return 0;
4353         }
4354         tcon->status = TID_IN_TCON;
4355         spin_unlock(&tcon->tc_lock);
4356
4357         rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4358         if (rc) {
4359                 spin_lock(&tcon->tc_lock);
4360                 if (tcon->status == TID_IN_TCON)
4361                         tcon->status = TID_NEED_TCON;
4362                 spin_unlock(&tcon->tc_lock);
4363         } else {
4364                 spin_lock(&tcon->tc_lock);
4365                 if (tcon->status == TID_IN_TCON)
4366                         tcon->status = TID_GOOD;
4367                 tcon->need_reconnect = false;
4368                 spin_unlock(&tcon->tc_lock);
4369         }
4370
4371         return rc;
4372 }
4373 #endif