fs/smb/client/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 MAX_STATUS_IO_TIMEOUT   5
  64
  65 static int ip_connect(struct TCP_Server_Info *server);
  66 static int generic_ip_connect(struct TCP_Server_Info *server);
  67 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  68 static void cifs_prune_tlinks(struct work_struct *work);
  69
  70 /*
  71  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  72  * get their ip addresses changed at some point.
  73  *
  74  * This should be called with server->srv_mutex held.
  75  */
  76 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  77 {
  78         int rc;
  79         int len;
  80         char *unc;
  81         struct sockaddr_storage ss;
  82
  83         if (!server->hostname)
  84                 return -EINVAL;
  85
  86         /* if server hostname isn't populated, there's nothing to do here */
  87         if (server->hostname[0] == '\0')
  88                 return 0;
  89
  90         len = strlen(server->hostname) + 3;
  91
  92         unc = kmalloc(len, GFP_KERNEL);
  93         if (!unc) {
  94                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
  95                 return -ENOMEM;
  96         }
  97         scnprintf(unc, len, "\\\\%s", server->hostname);
  98
  99         spin_lock(&server->srv_lock);
 100         ss = server->dstaddr;
 101         spin_unlock(&server->srv_lock);
 102
 103         rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, NULL);
 104         kfree(unc);
 105
 106         if (rc < 0) {
 107                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 108                          __func__, server->hostname, rc);
 109         } else {
 110                 spin_lock(&server->srv_lock);
 111                 memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 112                 spin_unlock(&server->srv_lock);
 113                 rc = 0;
 114         }
 115
 116         return rc;
 117 }
 118
 119 static void smb2_query_server_interfaces(struct work_struct *work)
 120 {
 121         int rc;
 122         struct cifs_tcon *tcon = container_of(work,
 123                                         struct cifs_tcon,
 124                                         query_interfaces.work);
 125
 126         /*
 127          * query server network interfaces, in case they change
 128          */
 129         rc = SMB3_request_interfaces(0, tcon, false);
 130         if (rc) {
 131                 cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 132                                 __func__, rc);
 133         }
 134
 135         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 136                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
 137 }
 138
 139 /*
 140  * Update the tcpStatus for the server.
 141  * This is used to signal the cifsd thread to call cifs_reconnect
 142  * ONLY cifsd thread should call cifs_reconnect. For any other
 143  * thread, use this function
 144  *
 145  * @server: the tcp ses for which reconnect is needed
 146  * @all_channels: if this needs to be done for all channels
 147  */
 148 void
 149 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 150                                 bool all_channels)
 151 {
 152         struct TCP_Server_Info *pserver;
 153         struct cifs_ses *ses;
 154         int i;
 155
 156         /* If server is a channel, select the primary channel */
 157         pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
 158
 159         spin_lock(&pserver->srv_lock);
 160         if (!all_channels) {
 161                 pserver->tcpStatus = CifsNeedReconnect;
 162                 spin_unlock(&pserver->srv_lock);
 163                 return;
 164         }
 165         spin_unlock(&pserver->srv_lock);
 166
 167         spin_lock(&cifs_tcp_ses_lock);
 168         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 169                 spin_lock(&ses->chan_lock);
 170                 for (i = 0; i < ses->chan_count; i++) {
 171                         spin_lock(&ses->chans[i].server->srv_lock);
 172                         ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 173                         spin_unlock(&ses->chans[i].server->srv_lock);
 174                 }
 175                 spin_unlock(&ses->chan_lock);
 176         }
 177         spin_unlock(&cifs_tcp_ses_lock);
 178 }
 179
 180 /*
 181  * Mark all sessions and tcons for reconnect.
 182  * IMPORTANT: make sure that this gets called only from
 183  * cifsd thread. For any other thread, use
 184  * cifs_signal_cifsd_for_reconnect
 185  *
 186  * @server: the tcp ses for which reconnect is needed
 187  * @server needs to be previously set to CifsNeedReconnect.
 188  * @mark_smb_session: whether even sessions need to be marked
 189  */
 190 void
 191 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 192                                       bool mark_smb_session)
 193 {
 194         struct TCP_Server_Info *pserver;
 195         struct cifs_ses *ses, *nses;
 196         struct cifs_tcon *tcon;
 197
 198         /*
 199          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 200          * are not used until reconnected.
 201          */
 202         cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 203
 204         /* If server is a channel, select the primary channel */
 205         pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
 206
 207
 208         spin_lock(&cifs_tcp_ses_lock);
 209         list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 210                 /* check if iface is still active */
 211                 if (!cifs_chan_is_iface_active(ses, server))
 212                         cifs_chan_update_iface(ses, server);
 213
 214                 spin_lock(&ses->chan_lock);
 215                 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server)) {
 216                         spin_unlock(&ses->chan_lock);
 217                         continue;
 218                 }
 219
 220                 if (mark_smb_session)
 221                         CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 222                 else
 223                         cifs_chan_set_need_reconnect(ses, server);
 224
 225                 cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
 226                          __func__, ses->chans_need_reconnect);
 227
 228                 /* If all channels need reconnect, then tcon needs reconnect */
 229                 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses)) {
 230                         spin_unlock(&ses->chan_lock);
 231                         continue;
 232                 }
 233                 spin_unlock(&ses->chan_lock);
 234
 235                 spin_lock(&ses->ses_lock);
 236                 ses->ses_status = SES_NEED_RECON;
 237                 spin_unlock(&ses->ses_lock);
 238
 239                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 240                         tcon->need_reconnect = true;
 241                         spin_lock(&tcon->tc_lock);
 242                         tcon->status = TID_NEED_RECON;
 243                         spin_unlock(&tcon->tc_lock);
 244                 }
 245                 if (ses->tcon_ipc) {
 246                         ses->tcon_ipc->need_reconnect = true;
 247                         spin_lock(&ses->tcon_ipc->tc_lock);
 248                         ses->tcon_ipc->status = TID_NEED_RECON;
 249                         spin_unlock(&ses->tcon_ipc->tc_lock);
 250                 }
 251         }
 252         spin_unlock(&cifs_tcp_ses_lock);
 253 }
 254
 255 static void
 256 cifs_abort_connection(struct TCP_Server_Info *server)
 257 {
 258         struct mid_q_entry *mid, *nmid;
 259         struct list_head retry_list;
 260
 261         server->maxBuf = 0;
 262         server->max_read = 0;
 263
 264         /* do not want to be sending data on a socket we are freeing */
 265         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 266         cifs_server_lock(server);
 267         if (server->ssocket) {
 268                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 269                          server->ssocket->flags);
 270                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 271                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 272                          server->ssocket->flags);
 273                 sock_release(server->ssocket);
 274                 server->ssocket = NULL;
 275         }
 276         server->sequence_number = 0;
 277         server->session_estab = false;
 278         kfree_sensitive(server->session_key.response);
 279         server->session_key.response = NULL;
 280         server->session_key.len = 0;
 281         server->lstrp = jiffies;
 282
 283         /* mark submitted MIDs for retry and issue callback */
 284         INIT_LIST_HEAD(&retry_list);
 285         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 286         spin_lock(&server->mid_lock);
 287         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 288                 kref_get(&mid->refcount);
 289                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 290                         mid->mid_state = MID_RETRY_NEEDED;
 291                 list_move(&mid->qhead, &retry_list);
 292                 mid->mid_flags |= MID_DELETED;
 293         }
 294         spin_unlock(&server->mid_lock);
 295         cifs_server_unlock(server);
 296
 297         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 298         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 299                 list_del_init(&mid->qhead);
 300                 mid->callback(mid);
 301                 release_mid(mid);
 302         }
 303
 304         if (cifs_rdma_enabled(server)) {
 305                 cifs_server_lock(server);
 306                 smbd_destroy(server);
 307                 cifs_server_unlock(server);
 308         }
 309 }
 310
 311 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 312 {
 313         spin_lock(&server->srv_lock);
 314         server->nr_targets = num_targets;
 315         if (server->tcpStatus == CifsExiting) {
 316                 /* the demux thread will exit normally next time through the loop */
 317                 spin_unlock(&server->srv_lock);
 318                 wake_up(&server->response_q);
 319                 return false;
 320         }
 321
 322         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 323         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 324                              server->hostname);
 325         server->tcpStatus = CifsNeedReconnect;
 326
 327         spin_unlock(&server->srv_lock);
 328         return true;
 329 }
 330
 331 /*
 332  * cifs tcp session reconnection
 333  *
 334  * mark tcp session as reconnecting so temporarily locked
 335  * mark all smb sessions as reconnecting for tcp session
 336  * reconnect tcp session
 337  * wake up waiters on reconnection? - (not needed currently)
 338  *
 339  * if mark_smb_session is passed as true, unconditionally mark
 340  * the smb session (and tcon) for reconnect as well. This value
 341  * doesn't really matter for non-multichannel scenario.
 342  *
 343  */
 344 static int __cifs_reconnect(struct TCP_Server_Info *server,
 345                             bool mark_smb_session)
 346 {
 347         int rc = 0;
 348
 349         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 350                 return 0;
 351
 352         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 353
 354         cifs_abort_connection(server);
 355
 356         do {
 357                 try_to_freeze();
 358                 cifs_server_lock(server);
 359
 360                 if (!cifs_swn_set_server_dstaddr(server)) {
 361                         /* resolve the hostname again to make sure that IP address is up-to-date */
 362                         rc = reconn_set_ipaddr_from_hostname(server);
 363                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 364                 }
 365
 366                 if (cifs_rdma_enabled(server))
 367                         rc = smbd_reconnect(server);
 368                 else
 369                         rc = generic_ip_connect(server);
 370                 if (rc) {
 371                         cifs_server_unlock(server);
 372                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 373                         msleep(3000);
 374                 } else {
 375                         atomic_inc(&tcpSesReconnectCount);
 376                         set_credits(server, 1);
 377                         spin_lock(&server->srv_lock);
 378                         if (server->tcpStatus != CifsExiting)
 379                                 server->tcpStatus = CifsNeedNegotiate;
 380                         spin_unlock(&server->srv_lock);
 381                         cifs_swn_reset_server_dstaddr(server);
 382                         cifs_server_unlock(server);
 383                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 384                 }
 385         } while (server->tcpStatus == CifsNeedReconnect);
 386
 387         spin_lock(&server->srv_lock);
 388         if (server->tcpStatus == CifsNeedNegotiate)
 389                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 390         spin_unlock(&server->srv_lock);
 391
 392         wake_up(&server->response_q);
 393         return rc;
 394 }
 395
 396 #ifdef CONFIG_CIFS_DFS_UPCALL
 397 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 398 {
 399         int rc;
 400         char *hostname;
 401
 402         if (!cifs_swn_set_server_dstaddr(server)) {
 403                 if (server->hostname != target) {
 404                         hostname = extract_hostname(target);
 405                         if (!IS_ERR(hostname)) {
 406                                 spin_lock(&server->srv_lock);
 407                                 kfree(server->hostname);
 408                                 server->hostname = hostname;
 409                                 spin_unlock(&server->srv_lock);
 410                         } else {
 411                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 412                                          __func__, PTR_ERR(hostname));
 413                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 414                                          server->hostname);
 415                         }
 416                 }
 417                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 418                 rc = reconn_set_ipaddr_from_hostname(server);
 419                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 420         }
 421         /* Reconnect the socket */
 422         if (cifs_rdma_enabled(server))
 423                 rc = smbd_reconnect(server);
 424         else
 425                 rc = generic_ip_connect(server);
 426
 427         return rc;
 428 }
 429
 430 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 431                                      struct dfs_cache_tgt_iterator **target_hint)
 432 {
 433         int rc;
 434         struct dfs_cache_tgt_iterator *tit;
 435
 436         *target_hint = NULL;
 437
 438         /* If dfs target list is empty, then reconnect to last server */
 439         tit = dfs_cache_get_tgt_iterator(tl);
 440         if (!tit)
 441                 return __reconnect_target_unlocked(server, server->hostname);
 442
 443         /* Otherwise, try every dfs target in @tl */
 444         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 445                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 446                 if (!rc) {
 447                         *target_hint = tit;
 448                         break;
 449                 }
 450         }
 451         return rc;
 452 }
 453
 454 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 455 {
 456         struct dfs_cache_tgt_iterator *target_hint = NULL;
 457         DFS_CACHE_TGT_LIST(tl);
 458         int num_targets = 0;
 459         int rc = 0;
 460
 461         /*
 462          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 463          *
 464          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 465          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 466          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 467          * refreshing the referral, so, in this case, default it to 1.
 468          */
 469         mutex_lock(&server->refpath_lock);
 470         if (!dfs_cache_noreq_find(server->leaf_fullpath + 1, NULL, &tl))
 471                 num_targets = dfs_cache_get_nr_tgts(&tl);
 472         mutex_unlock(&server->refpath_lock);
 473         if (!num_targets)
 474                 num_targets = 1;
 475
 476         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 477                 return 0;
 478
 479         /*
 480          * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 481          * different server or share during failover.  It could be improved by adding some logic to
 482          * only do that in case it connects to a different server or share, though.
 483          */
 484         cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 485
 486         cifs_abort_connection(server);
 487
 488         do {
 489                 try_to_freeze();
 490                 cifs_server_lock(server);
 491
 492                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 493                 if (rc) {
 494                         /* Failed to reconnect socket */
 495                         cifs_server_unlock(server);
 496                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 497                         msleep(3000);
 498                         continue;
 499                 }
 500                 /*
 501                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 502                  * process waiting for reconnect will know it needs to re-establish session and tcon
 503                  * through the reconnected target server.
 504                  */
 505                 atomic_inc(&tcpSesReconnectCount);
 506                 set_credits(server, 1);
 507                 spin_lock(&server->srv_lock);
 508                 if (server->tcpStatus != CifsExiting)
 509                         server->tcpStatus = CifsNeedNegotiate;
 510                 spin_unlock(&server->srv_lock);
 511                 cifs_swn_reset_server_dstaddr(server);
 512                 cifs_server_unlock(server);
 513                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 514         } while (server->tcpStatus == CifsNeedReconnect);
 515
 516         mutex_lock(&server->refpath_lock);
 517         dfs_cache_noreq_update_tgthint(server->leaf_fullpath + 1, target_hint);
 518         mutex_unlock(&server->refpath_lock);
 519         dfs_cache_free_tgts(&tl);
 520
 521         /* Need to set up echo worker again once connection has been established */
 522         spin_lock(&server->srv_lock);
 523         if (server->tcpStatus == CifsNeedNegotiate)
 524                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 525         spin_unlock(&server->srv_lock);
 526
 527         wake_up(&server->response_q);
 528         return rc;
 529 }
 530
 531 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 532 {
 533         mutex_lock(&server->refpath_lock);
 534         if (!server->leaf_fullpath) {
 535                 mutex_unlock(&server->refpath_lock);
 536                 return __cifs_reconnect(server, mark_smb_session);
 537         }
 538         mutex_unlock(&server->refpath_lock);
 539
 540         return reconnect_dfs_server(server);
 541 }
 542 #else
 543 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 544 {
 545         return __cifs_reconnect(server, mark_smb_session);
 546 }
 547 #endif
 548
 549 static void
 550 cifs_echo_request(struct work_struct *work)
 551 {
 552         int rc;
 553         struct TCP_Server_Info *server = container_of(work,
 554                                         struct TCP_Server_Info, echo.work);
 555
 556         /*
 557          * We cannot send an echo if it is disabled.
 558          * Also, no need to ping if we got a response recently.
 559          */
 560
 561         if (server->tcpStatus == CifsNeedReconnect ||
 562             server->tcpStatus == CifsExiting ||
 563             server->tcpStatus == CifsNew ||
 564             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 565             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 566                 goto requeue_echo;
 567
 568         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 569         cifs_server_dbg(FYI, "send echo request: rc = %d\n", rc);
 570
 571         /* Check witness registrations */
 572         cifs_swn_check();
 573
 574 requeue_echo:
 575         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 576 }
 577
 578 static bool
 579 allocate_buffers(struct TCP_Server_Info *server)
 580 {
 581         if (!server->bigbuf) {
 582                 server->bigbuf = (char *)cifs_buf_get();
 583                 if (!server->bigbuf) {
 584                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 585                         msleep(3000);
 586                         /* retry will check if exiting */
 587                         return false;
 588                 }
 589         } else if (server->large_buf) {
 590                 /* we are reusing a dirty large buf, clear its start */
 591                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 592         }
 593
 594         if (!server->smallbuf) {
 595                 server->smallbuf = (char *)cifs_small_buf_get();
 596                 if (!server->smallbuf) {
 597                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 598                         msleep(1000);
 599                         /* retry will check if exiting */
 600                         return false;
 601                 }
 602                 /* beginning of smb buffer is cleared in our buf_get */
 603         } else {
 604                 /* if existing small buf clear beginning */
 605                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 606         }
 607
 608         return true;
 609 }
 610
 611 static bool
 612 server_unresponsive(struct TCP_Server_Info *server)
 613 {
 614         /*
 615          * We need to wait 3 echo intervals to make sure we handle such
 616          * situations right:
 617          * 1s  client sends a normal SMB request
 618          * 2s  client gets a response
 619          * 30s echo workqueue job pops, and decides we got a response recently
 620          *     and don't need to send another
 621          * ...
 622          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 623          *     a response in >60s.
 624          */
 625         spin_lock(&server->srv_lock);
 626         if ((server->tcpStatus == CifsGood ||
 627             server->tcpStatus == CifsNeedNegotiate) &&
 628             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 629             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 630                 spin_unlock(&server->srv_lock);
 631                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 632                          (3 * server->echo_interval) / HZ);
 633                 cifs_reconnect(server, false);
 634                 return true;
 635         }
 636         spin_unlock(&server->srv_lock);
 637
 638         return false;
 639 }
 640
 641 static inline bool
 642 zero_credits(struct TCP_Server_Info *server)
 643 {
 644         int val;
 645
 646         spin_lock(&server->req_lock);
 647         val = server->credits + server->echo_credits + server->oplock_credits;
 648         if (server->in_flight == 0 && val == 0) {
 649                 spin_unlock(&server->req_lock);
 650                 return true;
 651         }
 652         spin_unlock(&server->req_lock);
 653         return false;
 654 }
 655
 656 static int
 657 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 658 {
 659         int length = 0;
 660         int total_read;
 661
 662         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 663                 try_to_freeze();
 664
 665                 /* reconnect if no credits and no requests in flight */
 666                 if (zero_credits(server)) {
 667                         cifs_reconnect(server, false);
 668                         return -ECONNABORTED;
 669                 }
 670
 671                 if (server_unresponsive(server))
 672                         return -ECONNABORTED;
 673                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 674                         length = smbd_recv(server->smbd_conn, smb_msg);
 675                 else
 676                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 677
 678                 spin_lock(&server->srv_lock);
 679                 if (server->tcpStatus == CifsExiting) {
 680                         spin_unlock(&server->srv_lock);
 681                         return -ESHUTDOWN;
 682                 }
 683
 684                 if (server->tcpStatus == CifsNeedReconnect) {
 685                         spin_unlock(&server->srv_lock);
 686                         cifs_reconnect(server, false);
 687                         return -ECONNABORTED;
 688                 }
 689                 spin_unlock(&server->srv_lock);
 690
 691                 if (length == -ERESTARTSYS ||
 692                     length == -EAGAIN ||
 693                     length == -EINTR) {
 694                         /*
 695                          * Minimum sleep to prevent looping, allowing socket
 696                          * to clear and app threads to set tcpStatus
 697                          * CifsNeedReconnect if server hung.
 698                          */
 699                         usleep_range(1000, 2000);
 700                         length = 0;
 701                         continue;
 702                 }
 703
 704                 if (length <= 0) {
 705                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 706                         cifs_reconnect(server, false);
 707                         return -ECONNABORTED;
 708                 }
 709         }
 710         return total_read;
 711 }
 712
 713 int
 714 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 715                       unsigned int to_read)
 716 {
 717         struct msghdr smb_msg = {};
 718         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 719         iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
 720
 721         return cifs_readv_from_socket(server, &smb_msg);
 722 }
 723
 724 ssize_t
 725 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 726 {
 727         struct msghdr smb_msg = {};
 728
 729         /*
 730          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 731          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 732          *  so little to initialize in struct msghdr
 733          */
 734         iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
 735
 736         return cifs_readv_from_socket(server, &smb_msg);
 737 }
 738
 739 int
 740 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 741         unsigned int page_offset, unsigned int to_read)
 742 {
 743         struct msghdr smb_msg = {};
 744         struct bio_vec bv;
 745
 746         bvec_set_page(&bv, page, to_read, page_offset);
 747         iov_iter_bvec(&smb_msg.msg_iter, ITER_DEST, &bv, 1, to_read);
 748         return cifs_readv_from_socket(server, &smb_msg);
 749 }
 750
 751 int
 752 cifs_read_iter_from_socket(struct TCP_Server_Info *server, struct iov_iter *iter,
 753                            unsigned int to_read)
 754 {
 755         struct msghdr smb_msg = { .msg_iter = *iter };
 756         int ret;
 757
 758         iov_iter_truncate(&smb_msg.msg_iter, to_read);
 759         ret = cifs_readv_from_socket(server, &smb_msg);
 760         if (ret > 0)
 761                 iov_iter_advance(iter, ret);
 762         return ret;
 763 }
 764
 765 static bool
 766 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 767 {
 768         /*
 769          * The first byte big endian of the length field,
 770          * is actually not part of the length but the type
 771          * with the most common, zero, as regular data.
 772          */
 773         switch (type) {
 774         case RFC1002_SESSION_MESSAGE:
 775                 /* Regular SMB response */
 776                 return true;
 777         case RFC1002_SESSION_KEEP_ALIVE:
 778                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 779                 break;
 780         case RFC1002_POSITIVE_SESSION_RESPONSE:
 781                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 782                 break;
 783         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 784                 /*
 785                  * We get this from Windows 98 instead of an error on
 786                  * SMB negprot response.
 787                  */
 788                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 789                 /* give server a second to clean up */
 790                 msleep(1000);
 791                 /*
 792                  * Always try 445 first on reconnect since we get NACK
 793                  * on some if we ever connected to port 139 (the NACK
 794                  * is since we do not begin with RFC1001 session
 795                  * initialize frame).
 796                  */
 797                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 798                 cifs_reconnect(server, true);
 799                 break;
 800         default:
 801                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 802                 cifs_reconnect(server, true);
 803         }
 804
 805         return false;
 806 }
 807
 808 void
 809 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 810 {
 811 #ifdef CONFIG_CIFS_STATS2
 812         mid->when_received = jiffies;
 813 #endif
 814         spin_lock(&mid->server->mid_lock);
 815         if (!malformed)
 816                 mid->mid_state = MID_RESPONSE_RECEIVED;
 817         else
 818                 mid->mid_state = MID_RESPONSE_MALFORMED;
 819         /*
 820          * Trying to handle/dequeue a mid after the send_recv()
 821          * function has finished processing it is a bug.
 822          */
 823         if (mid->mid_flags & MID_DELETED) {
 824                 spin_unlock(&mid->server->mid_lock);
 825                 pr_warn_once("trying to dequeue a deleted mid\n");
 826         } else {
 827                 list_del_init(&mid->qhead);
 828                 mid->mid_flags |= MID_DELETED;
 829                 spin_unlock(&mid->server->mid_lock);
 830         }
 831 }
 832
 833 static unsigned int
 834 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 835 {
 836         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 837
 838         /*
 839          * SMB1 does not use credits.
 840          */
 841         if (is_smb1(server))
 842                 return 0;
 843
 844         return le16_to_cpu(shdr->CreditRequest);
 845 }
 846
 847 static void
 848 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 849            char *buf, int malformed)
 850 {
 851         if (server->ops->check_trans2 &&
 852             server->ops->check_trans2(mid, server, buf, malformed))
 853                 return;
 854         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 855         mid->resp_buf = buf;
 856         mid->large_buf = server->large_buf;
 857         /* Was previous buf put in mpx struct for multi-rsp? */
 858         if (!mid->multiRsp) {
 859                 /* smb buffer will be freed by user thread */
 860                 if (server->large_buf)
 861                         server->bigbuf = NULL;
 862                 else
 863                         server->smallbuf = NULL;
 864         }
 865         dequeue_mid(mid, malformed);
 866 }
 867
 868 int
 869 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 870 {
 871         bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 872         bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 873         bool mnt_sign_enabled;
 874
 875         /*
 876          * Is signing required by mnt options? If not then check
 877          * global_secflags to see if it is there.
 878          */
 879         if (!mnt_sign_required)
 880                 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 881                                                 CIFSSEC_MUST_SIGN);
 882
 883         /*
 884          * If signing is required then it's automatically enabled too,
 885          * otherwise, check to see if the secflags allow it.
 886          */
 887         mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 888                                 (global_secflags & CIFSSEC_MAY_SIGN);
 889
 890         /* If server requires signing, does client allow it? */
 891         if (srv_sign_required) {
 892                 if (!mnt_sign_enabled) {
 893                         cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 894                         return -EOPNOTSUPP;
 895                 }
 896                 server->sign = true;
 897         }
 898
 899         /* If client requires signing, does server allow it? */
 900         if (mnt_sign_required) {
 901                 if (!srv_sign_enabled) {
 902                         cifs_dbg(VFS, "Server does not support signing!\n");
 903                         return -EOPNOTSUPP;
 904                 }
 905                 server->sign = true;
 906         }
 907
 908         if (cifs_rdma_enabled(server) && server->sign)
 909                 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 910
 911         return 0;
 912 }
 913
 914 static noinline_for_stack void
 915 clean_demultiplex_info(struct TCP_Server_Info *server)
 916 {
 917         int length;
 918
 919         /* take it off the list, if it's not already */
 920         spin_lock(&server->srv_lock);
 921         list_del_init(&server->tcp_ses_list);
 922         spin_unlock(&server->srv_lock);
 923
 924         cancel_delayed_work_sync(&server->echo);
 925
 926         spin_lock(&server->srv_lock);
 927         server->tcpStatus = CifsExiting;
 928         spin_unlock(&server->srv_lock);
 929         wake_up_all(&server->response_q);
 930
 931         /* check if we have blocked requests that need to free */
 932         spin_lock(&server->req_lock);
 933         if (server->credits <= 0)
 934                 server->credits = 1;
 935         spin_unlock(&server->req_lock);
 936         /*
 937          * Although there should not be any requests blocked on this queue it
 938          * can not hurt to be paranoid and try to wake up requests that may
 939          * haven been blocked when more than 50 at time were on the wire to the
 940          * same server - they now will see the session is in exit state and get
 941          * out of SendReceive.
 942          */
 943         wake_up_all(&server->request_q);
 944         /* give those requests time to exit */
 945         msleep(125);
 946         if (cifs_rdma_enabled(server))
 947                 smbd_destroy(server);
 948         if (server->ssocket) {
 949                 sock_release(server->ssocket);
 950                 server->ssocket = NULL;
 951         }
 952
 953         if (!list_empty(&server->pending_mid_q)) {
 954                 struct list_head dispose_list;
 955                 struct mid_q_entry *mid_entry;
 956                 struct list_head *tmp, *tmp2;
 957
 958                 INIT_LIST_HEAD(&dispose_list);
 959                 spin_lock(&server->mid_lock);
 960                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 961                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 962                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 963                         kref_get(&mid_entry->refcount);
 964                         mid_entry->mid_state = MID_SHUTDOWN;
 965                         list_move(&mid_entry->qhead, &dispose_list);
 966                         mid_entry->mid_flags |= MID_DELETED;
 967                 }
 968                 spin_unlock(&server->mid_lock);
 969
 970                 /* now walk dispose list and issue callbacks */
 971                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 972                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 973                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 974                         list_del_init(&mid_entry->qhead);
 975                         mid_entry->callback(mid_entry);
 976                         release_mid(mid_entry);
 977                 }
 978                 /* 1/8th of sec is more than enough time for them to exit */
 979                 msleep(125);
 980         }
 981
 982         if (!list_empty(&server->pending_mid_q)) {
 983                 /*
 984                  * mpx threads have not exited yet give them at least the smb
 985                  * send timeout time for long ops.
 986                  *
 987                  * Due to delays on oplock break requests, we need to wait at
 988                  * least 45 seconds before giving up on a request getting a
 989                  * response and going ahead and killing cifsd.
 990                  */
 991                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 992                 msleep(46000);
 993                 /*
 994                  * If threads still have not exited they are probably never
 995                  * coming home not much else we can do but free the memory.
 996                  */
 997         }
 998
 999         kfree(server->leaf_fullpath);
1000         kfree(server);
1001
1002         length = atomic_dec_return(&tcpSesAllocCount);
1003         if (length > 0)
1004                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1005 }
1006
1007 static int
1008 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1009 {
1010         int length;
1011         char *buf = server->smallbuf;
1012         unsigned int pdu_length = server->pdu_size;
1013
1014         /* make sure this will fit in a large buffer */
1015         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1016             HEADER_PREAMBLE_SIZE(server)) {
1017                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1018                 cifs_reconnect(server, true);
1019                 return -ECONNABORTED;
1020         }
1021
1022         /* switch to large buffer if too big for a small one */
1023         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1024                 server->large_buf = true;
1025                 memcpy(server->bigbuf, buf, server->total_read);
1026                 buf = server->bigbuf;
1027         }
1028
1029         /* now read the rest */
1030         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1031                                        pdu_length - MID_HEADER_SIZE(server));
1032
1033         if (length < 0)
1034                 return length;
1035         server->total_read += length;
1036
1037         dump_smb(buf, server->total_read);
1038
1039         return cifs_handle_standard(server, mid);
1040 }
1041
1042 int
1043 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1044 {
1045         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1046         int rc;
1047
1048         /*
1049          * We know that we received enough to get to the MID as we
1050          * checked the pdu_length earlier. Now check to see
1051          * if the rest of the header is OK.
1052          *
1053          * 48 bytes is enough to display the header and a little bit
1054          * into the payload for debugging purposes.
1055          */
1056         rc = server->ops->check_message(buf, server->total_read, server);
1057         if (rc)
1058                 cifs_dump_mem("Bad SMB: ", buf,
1059                         min_t(unsigned int, server->total_read, 48));
1060
1061         if (server->ops->is_session_expired &&
1062             server->ops->is_session_expired(buf)) {
1063                 cifs_reconnect(server, true);
1064                 return -1;
1065         }
1066
1067         if (server->ops->is_status_pending &&
1068             server->ops->is_status_pending(buf, server))
1069                 return -1;
1070
1071         if (!mid)
1072                 return rc;
1073
1074         handle_mid(mid, server, buf, rc);
1075         return 0;
1076 }
1077
1078 static void
1079 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1080 {
1081         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1082         int scredits, in_flight;
1083
1084         /*
1085          * SMB1 does not use credits.
1086          */
1087         if (is_smb1(server))
1088                 return;
1089
1090         if (shdr->CreditRequest) {
1091                 spin_lock(&server->req_lock);
1092                 server->credits += le16_to_cpu(shdr->CreditRequest);
1093                 scredits = server->credits;
1094                 in_flight = server->in_flight;
1095                 spin_unlock(&server->req_lock);
1096                 wake_up(&server->request_q);
1097
1098                 trace_smb3_hdr_credits(server->CurrentMid,
1099                                 server->conn_id, server->hostname, scredits,
1100                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1101                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1102                                 __func__, le16_to_cpu(shdr->CreditRequest),
1103                                 scredits);
1104         }
1105 }
1106
1107
1108 static int
1109 cifs_demultiplex_thread(void *p)
1110 {
1111         int i, num_mids, length;
1112         struct TCP_Server_Info *server = p;
1113         unsigned int pdu_length;
1114         unsigned int next_offset;
1115         char *buf = NULL;
1116         struct task_struct *task_to_wake = NULL;
1117         struct mid_q_entry *mids[MAX_COMPOUND];
1118         char *bufs[MAX_COMPOUND];
1119         unsigned int noreclaim_flag, num_io_timeout = 0;
1120         bool pending_reconnect = false;
1121
1122         noreclaim_flag = memalloc_noreclaim_save();
1123         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1124
1125         length = atomic_inc_return(&tcpSesAllocCount);
1126         if (length > 1)
1127                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1128
1129         set_freezable();
1130         allow_kernel_signal(SIGKILL);
1131         while (server->tcpStatus != CifsExiting) {
1132                 if (try_to_freeze())
1133                         continue;
1134
1135                 if (!allocate_buffers(server))
1136                         continue;
1137
1138                 server->large_buf = false;
1139                 buf = server->smallbuf;
1140                 pdu_length = 4; /* enough to get RFC1001 header */
1141
1142                 length = cifs_read_from_socket(server, buf, pdu_length);
1143                 if (length < 0)
1144                         continue;
1145
1146                 if (is_smb1(server))
1147                         server->total_read = length;
1148                 else
1149                         server->total_read = 0;
1150
1151                 /*
1152                  * The right amount was read from socket - 4 bytes,
1153                  * so we can now interpret the length field.
1154                  */
1155                 pdu_length = get_rfc1002_length(buf);
1156
1157                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1158                 if (!is_smb_response(server, buf[0]))
1159                         continue;
1160
1161                 pending_reconnect = false;
1162 next_pdu:
1163                 server->pdu_size = pdu_length;
1164
1165                 /* make sure we have enough to get to the MID */
1166                 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1167                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1168                                  server->pdu_size);
1169                         cifs_reconnect(server, true);
1170                         continue;
1171                 }
1172
1173                 /* read down to the MID */
1174                 length = cifs_read_from_socket(server,
1175                              buf + HEADER_PREAMBLE_SIZE(server),
1176                              MID_HEADER_SIZE(server));
1177                 if (length < 0)
1178                         continue;
1179                 server->total_read += length;
1180
1181                 if (server->ops->next_header) {
1182                         next_offset = server->ops->next_header(buf);
1183                         if (next_offset)
1184                                 server->pdu_size = next_offset;
1185                 }
1186
1187                 memset(mids, 0, sizeof(mids));
1188                 memset(bufs, 0, sizeof(bufs));
1189                 num_mids = 0;
1190
1191                 if (server->ops->is_transform_hdr &&
1192                     server->ops->receive_transform &&
1193                     server->ops->is_transform_hdr(buf)) {
1194                         length = server->ops->receive_transform(server,
1195                                                                 mids,
1196                                                                 bufs,
1197                                                                 &num_mids);
1198                 } else {
1199                         mids[0] = server->ops->find_mid(server, buf);
1200                         bufs[0] = buf;
1201                         num_mids = 1;
1202
1203                         if (!mids[0] || !mids[0]->receive)
1204                                 length = standard_receive3(server, mids[0]);
1205                         else
1206                                 length = mids[0]->receive(server, mids[0]);
1207                 }
1208
1209                 if (length < 0) {
1210                         for (i = 0; i < num_mids; i++)
1211                                 if (mids[i])
1212                                         release_mid(mids[i]);
1213                         continue;
1214                 }
1215
1216                 if (server->ops->is_status_io_timeout &&
1217                     server->ops->is_status_io_timeout(buf)) {
1218                         num_io_timeout++;
1219                         if (num_io_timeout > MAX_STATUS_IO_TIMEOUT) {
1220                                 cifs_server_dbg(VFS,
1221                                                 "Number of request timeouts exceeded %d. Reconnecting",
1222                                                 MAX_STATUS_IO_TIMEOUT);
1223
1224                                 pending_reconnect = true;
1225                                 num_io_timeout = 0;
1226                         }
1227                 }
1228
1229                 server->lstrp = jiffies;
1230
1231                 for (i = 0; i < num_mids; i++) {
1232                         if (mids[i] != NULL) {
1233                                 mids[i]->resp_buf_size = server->pdu_size;
1234
1235                                 if (bufs[i] != NULL) {
1236                                         if (server->ops->is_network_name_deleted &&
1237                                             server->ops->is_network_name_deleted(bufs[i],
1238                                                                                  server)) {
1239                                                 cifs_server_dbg(FYI,
1240                                                                 "Share deleted. Reconnect needed");
1241                                         }
1242                                 }
1243
1244                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1245                                         mids[i]->callback(mids[i]);
1246
1247                                 release_mid(mids[i]);
1248                         } else if (server->ops->is_oplock_break &&
1249                                    server->ops->is_oplock_break(bufs[i],
1250                                                                 server)) {
1251                                 smb2_add_credits_from_hdr(bufs[i], server);
1252                                 cifs_dbg(FYI, "Received oplock break\n");
1253                         } else {
1254                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1255                                                 atomic_read(&mid_count));
1256                                 cifs_dump_mem("Received Data is: ", bufs[i],
1257                                               HEADER_SIZE(server));
1258                                 smb2_add_credits_from_hdr(bufs[i], server);
1259 #ifdef CONFIG_CIFS_DEBUG2
1260                                 if (server->ops->dump_detail)
1261                                         server->ops->dump_detail(bufs[i],
1262                                                                  server);
1263                                 cifs_dump_mids(server);
1264 #endif /* CIFS_DEBUG2 */
1265                         }
1266                 }
1267
1268                 if (pdu_length > server->pdu_size) {
1269                         if (!allocate_buffers(server))
1270                                 continue;
1271                         pdu_length -= server->pdu_size;
1272                         server->total_read = 0;
1273                         server->large_buf = false;
1274                         buf = server->smallbuf;
1275                         goto next_pdu;
1276                 }
1277
1278                 /* do this reconnect at the very end after processing all MIDs */
1279                 if (pending_reconnect)
1280                         cifs_reconnect(server, true);
1281
1282         } /* end while !EXITING */
1283
1284         /* buffer usually freed in free_mid - need to free it here on exit */
1285         cifs_buf_release(server->bigbuf);
1286         if (server->smallbuf) /* no sense logging a debug message if NULL */
1287                 cifs_small_buf_release(server->smallbuf);
1288
1289         task_to_wake = xchg(&server->tsk, NULL);
1290         clean_demultiplex_info(server);
1291
1292         /* if server->tsk was NULL then wait for a signal before exiting */
1293         if (!task_to_wake) {
1294                 set_current_state(TASK_INTERRUPTIBLE);
1295                 while (!signal_pending(current)) {
1296                         schedule();
1297                         set_current_state(TASK_INTERRUPTIBLE);
1298                 }
1299                 set_current_state(TASK_RUNNING);
1300         }
1301
1302         memalloc_noreclaim_restore(noreclaim_flag);
1303         module_put_and_kthread_exit(0);
1304 }
1305
1306 int
1307 cifs_ipaddr_cmp(struct sockaddr *srcaddr, struct sockaddr *rhs)
1308 {
1309         struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1310         struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1311         struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1312         struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1313
1314         switch (srcaddr->sa_family) {
1315         case AF_UNSPEC:
1316                 switch (rhs->sa_family) {
1317                 case AF_UNSPEC:
1318                         return 0;
1319                 case AF_INET:
1320                 case AF_INET6:
1321                         return 1;
1322                 default:
1323                         return -1;
1324                 }
1325         case AF_INET: {
1326                 switch (rhs->sa_family) {
1327                 case AF_UNSPEC:
1328                         return -1;
1329                 case AF_INET:
1330                         return memcmp(saddr4, vaddr4,
1331                                       sizeof(struct sockaddr_in));
1332                 case AF_INET6:
1333                         return 1;
1334                 default:
1335                         return -1;
1336                 }
1337         }
1338         case AF_INET6: {
1339                 switch (rhs->sa_family) {
1340                 case AF_UNSPEC:
1341                 case AF_INET:
1342                         return -1;
1343                 case AF_INET6:
1344                         return memcmp(saddr6,
1345                                       vaddr6,
1346                                       sizeof(struct sockaddr_in6));
1347                 default:
1348                         return -1;
1349                 }
1350         }
1351         default:
1352                 return -1; /* don't expect to be here */
1353         }
1354 }
1355
1356 /*
1357  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1358  * if srcaddr is specified and matches the IP address of the rhs argument
1359  */
1360 bool
1361 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1362 {
1363         switch (srcaddr->sa_family) {
1364         case AF_UNSPEC:
1365                 return (rhs->sa_family == AF_UNSPEC);
1366         case AF_INET: {
1367                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1368                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1369                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1370         }
1371         case AF_INET6: {
1372                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1373                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1374                 return (ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr)
1375                         && saddr6->sin6_scope_id == vaddr6->sin6_scope_id);
1376         }
1377         default:
1378                 WARN_ON(1);
1379                 return false; /* don't expect to be here */
1380         }
1381 }
1382
1383 /*
1384  * If no port is specified in addr structure, we try to match with 445 port
1385  * and if it fails - with 139 ports. It should be called only if address
1386  * families of server and addr are equal.
1387  */
1388 static bool
1389 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1390 {
1391         __be16 port, *sport;
1392
1393         /* SMBDirect manages its own ports, don't match it here */
1394         if (server->rdma)
1395                 return true;
1396
1397         switch (addr->sa_family) {
1398         case AF_INET:
1399                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1400                 port = ((struct sockaddr_in *) addr)->sin_port;
1401                 break;
1402         case AF_INET6:
1403                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1404                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1405                 break;
1406         default:
1407                 WARN_ON(1);
1408                 return false;
1409         }
1410
1411         if (!port) {
1412                 port = htons(CIFS_PORT);
1413                 if (port == *sport)
1414                         return true;
1415
1416                 port = htons(RFC1001_PORT);
1417         }
1418
1419         return port == *sport;
1420 }
1421
1422 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1423 {
1424         if (!cifs_match_ipaddr(addr, (struct sockaddr *)&server->dstaddr))
1425                 return false;
1426
1427         return true;
1428 }
1429
1430 static bool
1431 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1432 {
1433         /*
1434          * The select_sectype function should either return the ctx->sectype
1435          * that was specified, or "Unspecified" if that sectype was not
1436          * compatible with the given NEGOTIATE request.
1437          */
1438         if (server->ops->select_sectype(server, ctx->sectype)
1439              == Unspecified)
1440                 return false;
1441
1442         /*
1443          * Now check if signing mode is acceptable. No need to check
1444          * global_secflags at this point since if MUST_SIGN is set then
1445          * the server->sign had better be too.
1446          */
1447         if (ctx->sign && !server->sign)
1448                 return false;
1449
1450         return true;
1451 }
1452
1453 /* this function must be called with srv_lock held */
1454 static int match_server(struct TCP_Server_Info *server,
1455                         struct smb3_fs_context *ctx,
1456                         bool match_super)
1457 {
1458         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1459
1460         lockdep_assert_held(&server->srv_lock);
1461
1462         if (ctx->nosharesock)
1463                 return 0;
1464
1465         /* this server does not share socket */
1466         if (server->nosharesock)
1467                 return 0;
1468
1469         /* If multidialect negotiation see if existing sessions match one */
1470         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1471                 if (server->vals->protocol_id < SMB30_PROT_ID)
1472                         return 0;
1473         } else if (strcmp(ctx->vals->version_string,
1474                    SMBDEFAULT_VERSION_STRING) == 0) {
1475                 if (server->vals->protocol_id < SMB21_PROT_ID)
1476                         return 0;
1477         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1478                 return 0;
1479
1480         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1481                 return 0;
1482
1483         if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1484                                (struct sockaddr *)&server->srcaddr))
1485                 return 0;
1486         /*
1487          * When matching cifs.ko superblocks (@match_super == true), we can't
1488          * really match either @server->leaf_fullpath or @server->dstaddr
1489          * directly since this @server might belong to a completely different
1490          * server -- in case of domain-based DFS referrals or DFS links -- as
1491          * provided earlier by mount(2) through 'source' and 'ip' options.
1492          *
1493          * Otherwise, match the DFS referral in @server->leaf_fullpath or the
1494          * destination address in @server->dstaddr.
1495          *
1496          * When using 'nodfs' mount option, we avoid sharing it with DFS
1497          * connections as they might failover.
1498          */
1499         if (!match_super) {
1500                 if (!ctx->nodfs) {
1501                         if (server->leaf_fullpath) {
1502                                 if (!ctx->leaf_fullpath ||
1503                                     strcasecmp(server->leaf_fullpath,
1504                                                ctx->leaf_fullpath))
1505                                         return 0;
1506                         } else if (ctx->leaf_fullpath) {
1507                                 return 0;
1508                         }
1509                 } else if (server->leaf_fullpath) {
1510                         return 0;
1511                 }
1512         }
1513
1514         /*
1515          * Match for a regular connection (address/hostname/port) which has no
1516          * DFS referrals set.
1517          */
1518         if (!server->leaf_fullpath &&
1519             (strcasecmp(server->hostname, ctx->server_hostname) ||
1520              !match_server_address(server, addr) ||
1521              !match_port(server, addr)))
1522                 return 0;
1523
1524         if (!match_security(server, ctx))
1525                 return 0;
1526
1527         if (server->echo_interval != ctx->echo_interval * HZ)
1528                 return 0;
1529
1530         if (server->rdma != ctx->rdma)
1531                 return 0;
1532
1533         if (server->ignore_signature != ctx->ignore_signature)
1534                 return 0;
1535
1536         if (server->min_offload != ctx->min_offload)
1537                 return 0;
1538
1539         return 1;
1540 }
1541
1542 struct TCP_Server_Info *
1543 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1544 {
1545         struct TCP_Server_Info *server;
1546
1547         spin_lock(&cifs_tcp_ses_lock);
1548         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1549                 spin_lock(&server->srv_lock);
1550                 /*
1551                  * Skip ses channels since they're only handled in lower layers
1552                  * (e.g. cifs_send_recv).
1553                  */
1554                 if (SERVER_IS_CHAN(server) ||
1555                     !match_server(server, ctx, false)) {
1556                         spin_unlock(&server->srv_lock);
1557                         continue;
1558                 }
1559                 spin_unlock(&server->srv_lock);
1560
1561                 ++server->srv_count;
1562                 spin_unlock(&cifs_tcp_ses_lock);
1563                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1564                 return server;
1565         }
1566         spin_unlock(&cifs_tcp_ses_lock);
1567         return NULL;
1568 }
1569
1570 void
1571 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1572 {
1573         struct task_struct *task;
1574
1575         spin_lock(&cifs_tcp_ses_lock);
1576         if (--server->srv_count > 0) {
1577                 spin_unlock(&cifs_tcp_ses_lock);
1578                 return;
1579         }
1580
1581         /* srv_count can never go negative */
1582         WARN_ON(server->srv_count < 0);
1583
1584         put_net(cifs_net_ns(server));
1585
1586         list_del_init(&server->tcp_ses_list);
1587         spin_unlock(&cifs_tcp_ses_lock);
1588
1589         /* For secondary channels, we pick up ref-count on the primary server */
1590         if (SERVER_IS_CHAN(server))
1591                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1592
1593         cancel_delayed_work_sync(&server->echo);
1594
1595         if (from_reconnect)
1596                 /*
1597                  * Avoid deadlock here: reconnect work calls
1598                  * cifs_put_tcp_session() at its end. Need to be sure
1599                  * that reconnect work does nothing with server pointer after
1600                  * that step.
1601                  */
1602                 cancel_delayed_work(&server->reconnect);
1603         else
1604                 cancel_delayed_work_sync(&server->reconnect);
1605
1606         spin_lock(&server->srv_lock);
1607         server->tcpStatus = CifsExiting;
1608         spin_unlock(&server->srv_lock);
1609
1610         cifs_crypto_secmech_release(server);
1611
1612         kfree_sensitive(server->session_key.response);
1613         server->session_key.response = NULL;
1614         server->session_key.len = 0;
1615         kfree(server->hostname);
1616         server->hostname = NULL;
1617
1618         task = xchg(&server->tsk, NULL);
1619         if (task)
1620                 send_sig(SIGKILL, task, 1);
1621 }
1622
1623 struct TCP_Server_Info *
1624 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1625                      struct TCP_Server_Info *primary_server)
1626 {
1627         struct TCP_Server_Info *tcp_ses = NULL;
1628         int rc;
1629
1630         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1631
1632         /* see if we already have a matching tcp_ses */
1633         tcp_ses = cifs_find_tcp_session(ctx);
1634         if (tcp_ses)
1635                 return tcp_ses;
1636
1637         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1638         if (!tcp_ses) {
1639                 rc = -ENOMEM;
1640                 goto out_err;
1641         }
1642
1643         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1644         if (!tcp_ses->hostname) {
1645                 rc = -ENOMEM;
1646                 goto out_err;
1647         }
1648
1649         if (ctx->leaf_fullpath) {
1650                 tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1651                 if (!tcp_ses->leaf_fullpath) {
1652                         rc = -ENOMEM;
1653                         goto out_err;
1654                 }
1655         }
1656
1657         if (ctx->nosharesock)
1658                 tcp_ses->nosharesock = true;
1659
1660         tcp_ses->ops = ctx->ops;
1661         tcp_ses->vals = ctx->vals;
1662         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1663
1664         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1665         tcp_ses->noblockcnt = ctx->rootfs;
1666         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1667         tcp_ses->noautotune = ctx->noautotune;
1668         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1669         tcp_ses->rdma = ctx->rdma;
1670         tcp_ses->in_flight = 0;
1671         tcp_ses->max_in_flight = 0;
1672         tcp_ses->credits = 1;
1673         if (primary_server) {
1674                 spin_lock(&cifs_tcp_ses_lock);
1675                 ++primary_server->srv_count;
1676                 spin_unlock(&cifs_tcp_ses_lock);
1677                 tcp_ses->primary_server = primary_server;
1678         }
1679         init_waitqueue_head(&tcp_ses->response_q);
1680         init_waitqueue_head(&tcp_ses->request_q);
1681         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1682         mutex_init(&tcp_ses->_srv_mutex);
1683         memcpy(tcp_ses->workstation_RFC1001_name,
1684                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1685         memcpy(tcp_ses->server_RFC1001_name,
1686                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1687         tcp_ses->session_estab = false;
1688         tcp_ses->sequence_number = 0;
1689         tcp_ses->channel_sequence_num = 0; /* only tracked for primary channel */
1690         tcp_ses->reconnect_instance = 1;
1691         tcp_ses->lstrp = jiffies;
1692         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1693         spin_lock_init(&tcp_ses->req_lock);
1694         spin_lock_init(&tcp_ses->srv_lock);
1695         spin_lock_init(&tcp_ses->mid_lock);
1696         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1697         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1698         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1699         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1700         mutex_init(&tcp_ses->reconnect_mutex);
1701 #ifdef CONFIG_CIFS_DFS_UPCALL
1702         mutex_init(&tcp_ses->refpath_lock);
1703 #endif
1704         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1705                sizeof(tcp_ses->srcaddr));
1706         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1707                 sizeof(tcp_ses->dstaddr));
1708         if (ctx->use_client_guid)
1709                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1710                        SMB2_CLIENT_GUID_SIZE);
1711         else
1712                 generate_random_uuid(tcp_ses->client_guid);
1713         /*
1714          * at this point we are the only ones with the pointer
1715          * to the struct since the kernel thread not created yet
1716          * no need to spinlock this init of tcpStatus or srv_count
1717          */
1718         tcp_ses->tcpStatus = CifsNew;
1719         ++tcp_ses->srv_count;
1720
1721         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1722                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1723                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1724         else
1725                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1726         if (tcp_ses->rdma) {
1727 #ifndef CONFIG_CIFS_SMB_DIRECT
1728                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1729                 rc = -ENOENT;
1730                 goto out_err_crypto_release;
1731 #endif
1732                 tcp_ses->smbd_conn = smbd_get_connection(
1733                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1734                 if (tcp_ses->smbd_conn) {
1735                         cifs_dbg(VFS, "RDMA transport established\n");
1736                         rc = 0;
1737                         goto smbd_connected;
1738                 } else {
1739                         rc = -ENOENT;
1740                         goto out_err_crypto_release;
1741                 }
1742         }
1743         rc = ip_connect(tcp_ses);
1744         if (rc < 0) {
1745                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1746                 goto out_err_crypto_release;
1747         }
1748 smbd_connected:
1749         /*
1750          * since we're in a cifs function already, we know that
1751          * this will succeed. No need for try_module_get().
1752          */
1753         __module_get(THIS_MODULE);
1754         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1755                                   tcp_ses, "cifsd");
1756         if (IS_ERR(tcp_ses->tsk)) {
1757                 rc = PTR_ERR(tcp_ses->tsk);
1758                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1759                 module_put(THIS_MODULE);
1760                 goto out_err_crypto_release;
1761         }
1762         tcp_ses->min_offload = ctx->min_offload;
1763         /*
1764          * at this point we are the only ones with the pointer
1765          * to the struct since the kernel thread not created yet
1766          * no need to spinlock this update of tcpStatus
1767          */
1768         spin_lock(&tcp_ses->srv_lock);
1769         tcp_ses->tcpStatus = CifsNeedNegotiate;
1770         spin_unlock(&tcp_ses->srv_lock);
1771
1772         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1773                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1774         else
1775                 tcp_ses->max_credits = ctx->max_credits;
1776
1777         tcp_ses->nr_targets = 1;
1778         tcp_ses->ignore_signature = ctx->ignore_signature;
1779         /* thread spawned, put it on the list */
1780         spin_lock(&cifs_tcp_ses_lock);
1781         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1782         spin_unlock(&cifs_tcp_ses_lock);
1783
1784         /* queue echo request delayed work */
1785         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1786
1787         return tcp_ses;
1788
1789 out_err_crypto_release:
1790         cifs_crypto_secmech_release(tcp_ses);
1791
1792         put_net(cifs_net_ns(tcp_ses));
1793
1794 out_err:
1795         if (tcp_ses) {
1796                 if (SERVER_IS_CHAN(tcp_ses))
1797                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1798                 kfree(tcp_ses->hostname);
1799                 kfree(tcp_ses->leaf_fullpath);
1800                 if (tcp_ses->ssocket)
1801                         sock_release(tcp_ses->ssocket);
1802                 kfree(tcp_ses);
1803         }
1804         return ERR_PTR(rc);
1805 }
1806
1807 /* this function must be called with ses_lock and chan_lock held */
1808 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1809 {
1810         if (ctx->sectype != Unspecified &&
1811             ctx->sectype != ses->sectype)
1812                 return 0;
1813
1814         /*
1815          * If an existing session is limited to less channels than
1816          * requested, it should not be reused
1817          */
1818         if (ses->chan_max < ctx->max_channels)
1819                 return 0;
1820
1821         switch (ses->sectype) {
1822         case Kerberos:
1823                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1824                         return 0;
1825                 break;
1826         default:
1827                 /* NULL username means anonymous session */
1828                 if (ses->user_name == NULL) {
1829                         if (!ctx->nullauth)
1830                                 return 0;
1831                         break;
1832                 }
1833
1834                 /* anything else takes username/password */
1835                 if (strncmp(ses->user_name,
1836                             ctx->username ? ctx->username : "",
1837                             CIFS_MAX_USERNAME_LEN))
1838                         return 0;
1839                 if ((ctx->username && strlen(ctx->username) != 0) &&
1840                     ses->password != NULL &&
1841                     strncmp(ses->password,
1842                             ctx->password ? ctx->password : "",
1843                             CIFS_MAX_PASSWORD_LEN))
1844                         return 0;
1845         }
1846
1847         if (strcmp(ctx->local_nls->charset, ses->local_nls->charset))
1848                 return 0;
1849
1850         return 1;
1851 }
1852
1853 /**
1854  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1855  * @ses: smb session to issue the request on
1856  * @ctx: the superblock configuration context to use for building the
1857  *       new tree connection for the IPC (interprocess communication RPC)
1858  *
1859  * A new IPC connection is made and stored in the session
1860  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1861  */
1862 static int
1863 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1864 {
1865         int rc = 0, xid;
1866         struct cifs_tcon *tcon;
1867         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1868         bool seal = false;
1869         struct TCP_Server_Info *server = ses->server;
1870
1871         /*
1872          * If the mount request that resulted in the creation of the
1873          * session requires encryption, force IPC to be encrypted too.
1874          */
1875         if (ctx->seal) {
1876                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1877                         seal = true;
1878                 else {
1879                         cifs_server_dbg(VFS,
1880                                  "IPC: server doesn't support encryption\n");
1881                         return -EOPNOTSUPP;
1882                 }
1883         }
1884
1885         /* no need to setup directory caching on IPC share, so pass in false */
1886         tcon = tcon_info_alloc(false);
1887         if (tcon == NULL)
1888                 return -ENOMEM;
1889
1890         spin_lock(&server->srv_lock);
1891         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1892         spin_unlock(&server->srv_lock);
1893
1894         xid = get_xid();
1895         tcon->ses = ses;
1896         tcon->ipc = true;
1897         tcon->seal = seal;
1898         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1899         free_xid(xid);
1900
1901         if (rc) {
1902                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1903                 tconInfoFree(tcon);
1904                 goto out;
1905         }
1906
1907         cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1908
1909         spin_lock(&tcon->tc_lock);
1910         tcon->status = TID_GOOD;
1911         spin_unlock(&tcon->tc_lock);
1912         ses->tcon_ipc = tcon;
1913 out:
1914         return rc;
1915 }
1916
1917 /**
1918  * cifs_free_ipc - helper to release the session IPC tcon
1919  * @ses: smb session to unmount the IPC from
1920  *
1921  * Needs to be called everytime a session is destroyed.
1922  *
1923  * On session close, the IPC is closed and the server must release all tcons of the session.
1924  * No need to send a tree disconnect here.
1925  *
1926  * Besides, it will make the server to not close durable and resilient files on session close, as
1927  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1928  */
1929 static int
1930 cifs_free_ipc(struct cifs_ses *ses)
1931 {
1932         struct cifs_tcon *tcon = ses->tcon_ipc;
1933
1934         if (tcon == NULL)
1935                 return 0;
1936
1937         tconInfoFree(tcon);
1938         ses->tcon_ipc = NULL;
1939         return 0;
1940 }
1941
1942 static struct cifs_ses *
1943 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1944 {
1945         struct cifs_ses *ses, *ret = NULL;
1946
1947         spin_lock(&cifs_tcp_ses_lock);
1948         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1949                 spin_lock(&ses->ses_lock);
1950                 if (ses->ses_status == SES_EXITING) {
1951                         spin_unlock(&ses->ses_lock);
1952                         continue;
1953                 }
1954                 spin_lock(&ses->chan_lock);
1955                 if (match_session(ses, ctx)) {
1956                         spin_unlock(&ses->chan_lock);
1957                         spin_unlock(&ses->ses_lock);
1958                         ret = ses;
1959                         break;
1960                 }
1961                 spin_unlock(&ses->chan_lock);
1962                 spin_unlock(&ses->ses_lock);
1963         }
1964         if (ret)
1965                 cifs_smb_ses_inc_refcount(ret);
1966         spin_unlock(&cifs_tcp_ses_lock);
1967         return ret;
1968 }
1969
1970 void __cifs_put_smb_ses(struct cifs_ses *ses)
1971 {
1972         unsigned int rc, xid;
1973         unsigned int chan_count;
1974         struct TCP_Server_Info *server = ses->server;
1975
1976         spin_lock(&ses->ses_lock);
1977         if (ses->ses_status == SES_EXITING) {
1978                 spin_unlock(&ses->ses_lock);
1979                 return;
1980         }
1981         spin_unlock(&ses->ses_lock);
1982
1983         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1984         cifs_dbg(FYI,
1985                  "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1986
1987         spin_lock(&cifs_tcp_ses_lock);
1988         if (--ses->ses_count > 0) {
1989                 spin_unlock(&cifs_tcp_ses_lock);
1990                 return;
1991         }
1992         spin_lock(&ses->ses_lock);
1993         if (ses->ses_status == SES_GOOD)
1994                 ses->ses_status = SES_EXITING;
1995         spin_unlock(&ses->ses_lock);
1996         spin_unlock(&cifs_tcp_ses_lock);
1997
1998         /* ses_count can never go negative */
1999         WARN_ON(ses->ses_count < 0);
2000
2001         spin_lock(&ses->ses_lock);
2002         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
2003                 spin_unlock(&ses->ses_lock);
2004                 cifs_free_ipc(ses);
2005                 xid = get_xid();
2006                 rc = server->ops->logoff(xid, ses);
2007                 if (rc)
2008                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
2009                                 __func__, rc);
2010                 _free_xid(xid);
2011         } else {
2012                 spin_unlock(&ses->ses_lock);
2013                 cifs_free_ipc(ses);
2014         }
2015
2016         spin_lock(&cifs_tcp_ses_lock);
2017         list_del_init(&ses->smb_ses_list);
2018         spin_unlock(&cifs_tcp_ses_lock);
2019
2020         chan_count = ses->chan_count;
2021
2022         /* close any extra channels */
2023         if (chan_count > 1) {
2024                 int i;
2025
2026                 for (i = 1; i < chan_count; i++) {
2027                         if (ses->chans[i].iface) {
2028                                 kref_put(&ses->chans[i].iface->refcount, release_iface);
2029                                 ses->chans[i].iface = NULL;
2030                         }
2031                         cifs_put_tcp_session(ses->chans[i].server, 0);
2032                         ses->chans[i].server = NULL;
2033                 }
2034         }
2035
2036         sesInfoFree(ses);
2037         cifs_put_tcp_session(server, 0);
2038 }
2039
2040 #ifdef CONFIG_KEYS
2041
2042 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
2043 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2044
2045 /* Populate username and pw fields from keyring if possible */
2046 static int
2047 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2048 {
2049         int rc = 0;
2050         int is_domain = 0;
2051         const char *delim, *payload;
2052         char *desc;
2053         ssize_t len;
2054         struct key *key;
2055         struct TCP_Server_Info *server = ses->server;
2056         struct sockaddr_in *sa;
2057         struct sockaddr_in6 *sa6;
2058         const struct user_key_payload *upayload;
2059
2060         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2061         if (!desc)
2062                 return -ENOMEM;
2063
2064         /* try to find an address key first */
2065         switch (server->dstaddr.ss_family) {
2066         case AF_INET:
2067                 sa = (struct sockaddr_in *)&server->dstaddr;
2068                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2069                 break;
2070         case AF_INET6:
2071                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2072                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2073                 break;
2074         default:
2075                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2076                          server->dstaddr.ss_family);
2077                 rc = -EINVAL;
2078                 goto out_err;
2079         }
2080
2081         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2082         key = request_key(&key_type_logon, desc, "");
2083         if (IS_ERR(key)) {
2084                 if (!ses->domainName) {
2085                         cifs_dbg(FYI, "domainName is NULL\n");
2086                         rc = PTR_ERR(key);
2087                         goto out_err;
2088                 }
2089
2090                 /* didn't work, try to find a domain key */
2091                 sprintf(desc, "cifs:d:%s", ses->domainName);
2092                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2093                 key = request_key(&key_type_logon, desc, "");
2094                 if (IS_ERR(key)) {
2095                         rc = PTR_ERR(key);
2096                         goto out_err;
2097                 }
2098                 is_domain = 1;
2099         }
2100
2101         down_read(&key->sem);
2102         upayload = user_key_payload_locked(key);
2103         if (IS_ERR_OR_NULL(upayload)) {
2104                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2105                 goto out_key_put;
2106         }
2107
2108         /* find first : in payload */
2109         payload = upayload->data;
2110         delim = strnchr(payload, upayload->datalen, ':');
2111         cifs_dbg(FYI, "payload=%s\n", payload);
2112         if (!delim) {
2113                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2114                          upayload->datalen);
2115                 rc = -EINVAL;
2116                 goto out_key_put;
2117         }
2118
2119         len = delim - payload;
2120         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2121                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2122                          len);
2123                 rc = -EINVAL;
2124                 goto out_key_put;
2125         }
2126
2127         ctx->username = kstrndup(payload, len, GFP_KERNEL);
2128         if (!ctx->username) {
2129                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2130                          len);
2131                 rc = -ENOMEM;
2132                 goto out_key_put;
2133         }
2134         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2135
2136         len = key->datalen - (len + 1);
2137         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2138                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2139                 rc = -EINVAL;
2140                 kfree(ctx->username);
2141                 ctx->username = NULL;
2142                 goto out_key_put;
2143         }
2144
2145         ++delim;
2146         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2147         if (!ctx->password) {
2148                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2149                          len);
2150                 rc = -ENOMEM;
2151                 kfree(ctx->username);
2152                 ctx->username = NULL;
2153                 goto out_key_put;
2154         }
2155
2156         /*
2157          * If we have a domain key then we must set the domainName in the
2158          * for the request.
2159          */
2160         if (is_domain && ses->domainName) {
2161                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2162                 if (!ctx->domainname) {
2163                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2164                                  len);
2165                         rc = -ENOMEM;
2166                         kfree(ctx->username);
2167                         ctx->username = NULL;
2168                         kfree_sensitive(ctx->password);
2169                         ctx->password = NULL;
2170                         goto out_key_put;
2171                 }
2172         }
2173
2174         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2175
2176 out_key_put:
2177         up_read(&key->sem);
2178         key_put(key);
2179 out_err:
2180         kfree(desc);
2181         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2182         return rc;
2183 }
2184 #else /* ! CONFIG_KEYS */
2185 static inline int
2186 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2187                    struct cifs_ses *ses __attribute__((unused)))
2188 {
2189         return -ENOSYS;
2190 }
2191 #endif /* CONFIG_KEYS */
2192
2193 /**
2194  * cifs_get_smb_ses - get a session matching @ctx data from @server
2195  * @server: server to setup the session to
2196  * @ctx: superblock configuration context to use to setup the session
2197  *
2198  * This function assumes it is being called from cifs_mount() where we
2199  * already got a server reference (server refcount +1). See
2200  * cifs_get_tcon() for refcount explanations.
2201  */
2202 struct cifs_ses *
2203 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2204 {
2205         int rc = 0;
2206         unsigned int xid;
2207         struct cifs_ses *ses;
2208         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2209         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2210
2211         xid = get_xid();
2212
2213         ses = cifs_find_smb_ses(server, ctx);
2214         if (ses) {
2215                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2216                          ses->ses_status);
2217
2218                 spin_lock(&ses->chan_lock);
2219                 if (cifs_chan_needs_reconnect(ses, server)) {
2220                         spin_unlock(&ses->chan_lock);
2221                         cifs_dbg(FYI, "Session needs reconnect\n");
2222
2223                         mutex_lock(&ses->session_mutex);
2224                         rc = cifs_negotiate_protocol(xid, ses, server);
2225                         if (rc) {
2226                                 mutex_unlock(&ses->session_mutex);
2227                                 /* problem -- put our ses reference */
2228                                 cifs_put_smb_ses(ses);
2229                                 free_xid(xid);
2230                                 return ERR_PTR(rc);
2231                         }
2232
2233                         rc = cifs_setup_session(xid, ses, server,
2234                                                 ctx->local_nls);
2235                         if (rc) {
2236                                 mutex_unlock(&ses->session_mutex);
2237                                 /* problem -- put our reference */
2238                                 cifs_put_smb_ses(ses);
2239                                 free_xid(xid);
2240                                 return ERR_PTR(rc);
2241                         }
2242                         mutex_unlock(&ses->session_mutex);
2243
2244                         spin_lock(&ses->chan_lock);
2245                 }
2246                 spin_unlock(&ses->chan_lock);
2247
2248                 /* existing SMB ses has a server reference already */
2249                 cifs_put_tcp_session(server, 0);
2250                 free_xid(xid);
2251                 return ses;
2252         }
2253
2254         rc = -ENOMEM;
2255
2256         cifs_dbg(FYI, "Existing smb sess not found\n");
2257         ses = sesInfoAlloc();
2258         if (ses == NULL)
2259                 goto get_ses_fail;
2260
2261         /* new SMB session uses our server ref */
2262         ses->server = server;
2263         if (server->dstaddr.ss_family == AF_INET6)
2264                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2265         else
2266                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2267
2268         if (ctx->username) {
2269                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2270                 if (!ses->user_name)
2271                         goto get_ses_fail;
2272         }
2273
2274         /* ctx->password freed at unmount */
2275         if (ctx->password) {
2276                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2277                 if (!ses->password)
2278                         goto get_ses_fail;
2279         }
2280         if (ctx->domainname) {
2281                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2282                 if (!ses->domainName)
2283                         goto get_ses_fail;
2284         }
2285
2286         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2287
2288         if (ctx->domainauto)
2289                 ses->domainAuto = ctx->domainauto;
2290         ses->cred_uid = ctx->cred_uid;
2291         ses->linux_uid = ctx->linux_uid;
2292
2293         ses->sectype = ctx->sectype;
2294         ses->sign = ctx->sign;
2295         ses->local_nls = load_nls(ctx->local_nls->charset);
2296
2297         /* add server as first channel */
2298         spin_lock(&ses->chan_lock);
2299         ses->chans[0].server = server;
2300         ses->chan_count = 1;
2301         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2302         ses->chans_need_reconnect = 1;
2303         spin_unlock(&ses->chan_lock);
2304
2305         mutex_lock(&ses->session_mutex);
2306         rc = cifs_negotiate_protocol(xid, ses, server);
2307         if (!rc)
2308                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2309         mutex_unlock(&ses->session_mutex);
2310
2311         /* each channel uses a different signing key */
2312         spin_lock(&ses->chan_lock);
2313         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2314                sizeof(ses->smb3signingkey));
2315         spin_unlock(&ses->chan_lock);
2316
2317         if (rc)
2318                 goto get_ses_fail;
2319
2320         /*
2321          * success, put it on the list and add it as first channel
2322          * note: the session becomes active soon after this. So you'll
2323          * need to lock before changing something in the session.
2324          */
2325         spin_lock(&cifs_tcp_ses_lock);
2326         ses->dfs_root_ses = ctx->dfs_root_ses;
2327         if (ses->dfs_root_ses)
2328                 ses->dfs_root_ses->ses_count++;
2329         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2330         spin_unlock(&cifs_tcp_ses_lock);
2331
2332         cifs_setup_ipc(ses, ctx);
2333
2334         free_xid(xid);
2335
2336         return ses;
2337
2338 get_ses_fail:
2339         sesInfoFree(ses);
2340         free_xid(xid);
2341         return ERR_PTR(rc);
2342 }
2343
2344 /* this function must be called with tc_lock held */
2345 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2346 {
2347         struct TCP_Server_Info *server = tcon->ses->server;
2348
2349         if (tcon->status == TID_EXITING)
2350                 return 0;
2351
2352         if (tcon->origin_fullpath) {
2353                 if (!ctx->source ||
2354                     !dfs_src_pathname_equal(ctx->source,
2355                                             tcon->origin_fullpath))
2356                         return 0;
2357         } else if (!server->leaf_fullpath &&
2358                    strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE)) {
2359                 return 0;
2360         }
2361         if (tcon->seal != ctx->seal)
2362                 return 0;
2363         if (tcon->snapshot_time != ctx->snapshot_time)
2364                 return 0;
2365         if (tcon->handle_timeout != ctx->handle_timeout)
2366                 return 0;
2367         if (tcon->no_lease != ctx->no_lease)
2368                 return 0;
2369         if (tcon->nodelete != ctx->nodelete)
2370                 return 0;
2371         return 1;
2372 }
2373
2374 static struct cifs_tcon *
2375 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2376 {
2377         struct cifs_tcon *tcon;
2378
2379         spin_lock(&cifs_tcp_ses_lock);
2380         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2381                 spin_lock(&tcon->tc_lock);
2382                 if (!match_tcon(tcon, ctx)) {
2383                         spin_unlock(&tcon->tc_lock);
2384                         continue;
2385                 }
2386                 ++tcon->tc_count;
2387                 spin_unlock(&tcon->tc_lock);
2388                 spin_unlock(&cifs_tcp_ses_lock);
2389                 return tcon;
2390         }
2391         spin_unlock(&cifs_tcp_ses_lock);
2392         return NULL;
2393 }
2394
2395 void
2396 cifs_put_tcon(struct cifs_tcon *tcon)
2397 {
2398         unsigned int xid;
2399         struct cifs_ses *ses;
2400
2401         /*
2402          * IPC tcon share the lifetime of their session and are
2403          * destroyed in the session put function
2404          */
2405         if (tcon == NULL || tcon->ipc)
2406                 return;
2407
2408         ses = tcon->ses;
2409         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2410         spin_lock(&cifs_tcp_ses_lock);
2411         spin_lock(&tcon->tc_lock);
2412         if (--tcon->tc_count > 0) {
2413                 spin_unlock(&tcon->tc_lock);
2414                 spin_unlock(&cifs_tcp_ses_lock);
2415                 return;
2416         }
2417
2418         /* tc_count can never go negative */
2419         WARN_ON(tcon->tc_count < 0);
2420
2421         list_del_init(&tcon->tcon_list);
2422         tcon->status = TID_EXITING;
2423         spin_unlock(&tcon->tc_lock);
2424         spin_unlock(&cifs_tcp_ses_lock);
2425
2426         /* cancel polling of interfaces */
2427         cancel_delayed_work_sync(&tcon->query_interfaces);
2428 #ifdef CONFIG_CIFS_DFS_UPCALL
2429         cancel_delayed_work_sync(&tcon->dfs_cache_work);
2430 #endif
2431
2432         if (tcon->use_witness) {
2433                 int rc;
2434
2435                 rc = cifs_swn_unregister(tcon);
2436                 if (rc < 0) {
2437                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2438                                         __func__, rc);
2439                 }
2440         }
2441
2442         xid = get_xid();
2443         if (ses->server->ops->tree_disconnect)
2444                 ses->server->ops->tree_disconnect(xid, tcon);
2445         _free_xid(xid);
2446
2447         cifs_fscache_release_super_cookie(tcon);
2448         tconInfoFree(tcon);
2449         cifs_put_smb_ses(ses);
2450 }
2451
2452 /**
2453  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2454  * @ses: smb session to issue the request on
2455  * @ctx: the superblock configuration context to use for building the
2456  *
2457  * - tcon refcount is the number of mount points using the tcon.
2458  * - ses refcount is the number of tcon using the session.
2459  *
2460  * 1. This function assumes it is being called from cifs_mount() where
2461  *    we already got a session reference (ses refcount +1).
2462  *
2463  * 2. Since we're in the context of adding a mount point, the end
2464  *    result should be either:
2465  *
2466  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2467  *    its session refcount incremented (1 new tcon). This +1 was
2468  *    already done in (1).
2469  *
2470  * b) an existing tcon with refcount+1 (add a mount point to it) and
2471  *    identical ses refcount (no new tcon). Because of (1) we need to
2472  *    decrement the ses refcount.
2473  */
2474 static struct cifs_tcon *
2475 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2476 {
2477         struct cifs_tcon *tcon;
2478         bool nohandlecache;
2479         int rc, xid;
2480
2481         tcon = cifs_find_tcon(ses, ctx);
2482         if (tcon) {
2483                 /*
2484                  * tcon has refcount already incremented but we need to
2485                  * decrement extra ses reference gotten by caller (case b)
2486                  */
2487                 cifs_dbg(FYI, "Found match on UNC path\n");
2488                 cifs_put_smb_ses(ses);
2489                 return tcon;
2490         }
2491
2492         if (!ses->server->ops->tree_connect) {
2493                 rc = -ENOSYS;
2494                 goto out_fail;
2495         }
2496
2497         if (ses->server->dialect >= SMB20_PROT_ID &&
2498             (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
2499                 nohandlecache = ctx->nohandlecache;
2500         else
2501                 nohandlecache = true;
2502         tcon = tcon_info_alloc(!nohandlecache);
2503         if (tcon == NULL) {
2504                 rc = -ENOMEM;
2505                 goto out_fail;
2506         }
2507         tcon->nohandlecache = nohandlecache;
2508
2509         if (ctx->snapshot_time) {
2510                 if (ses->server->vals->protocol_id == 0) {
2511                         cifs_dbg(VFS,
2512                              "Use SMB2 or later for snapshot mount option\n");
2513                         rc = -EOPNOTSUPP;
2514                         goto out_fail;
2515                 } else
2516                         tcon->snapshot_time = ctx->snapshot_time;
2517         }
2518
2519         if (ctx->handle_timeout) {
2520                 if (ses->server->vals->protocol_id == 0) {
2521                         cifs_dbg(VFS,
2522                              "Use SMB2.1 or later for handle timeout option\n");
2523                         rc = -EOPNOTSUPP;
2524                         goto out_fail;
2525                 } else
2526                         tcon->handle_timeout = ctx->handle_timeout;
2527         }
2528
2529         tcon->ses = ses;
2530         if (ctx->password) {
2531                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2532                 if (!tcon->password) {
2533                         rc = -ENOMEM;
2534                         goto out_fail;
2535                 }
2536         }
2537
2538         if (ctx->seal) {
2539                 if (ses->server->vals->protocol_id == 0) {
2540                         cifs_dbg(VFS,
2541                                  "SMB3 or later required for encryption\n");
2542                         rc = -EOPNOTSUPP;
2543                         goto out_fail;
2544                 } else if (tcon->ses->server->capabilities &
2545                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2546                         tcon->seal = true;
2547                 else {
2548                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2549                         rc = -EOPNOTSUPP;
2550                         goto out_fail;
2551                 }
2552         }
2553
2554         if (ctx->linux_ext) {
2555                 if (ses->server->posix_ext_supported) {
2556                         tcon->posix_extensions = true;
2557                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2558                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2559                     (strcmp(ses->server->vals->version_string,
2560                      SMB3ANY_VERSION_STRING) == 0) ||
2561                     (strcmp(ses->server->vals->version_string,
2562                      SMBDEFAULT_VERSION_STRING) == 0)) {
2563                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2564                         rc = -EOPNOTSUPP;
2565                         goto out_fail;
2566                 } else {
2567                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2568                                 "disabled but required for POSIX extensions\n");
2569                         rc = -EOPNOTSUPP;
2570                         goto out_fail;
2571                 }
2572         }
2573
2574         xid = get_xid();
2575         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2576                                             ctx->local_nls);
2577         free_xid(xid);
2578         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2579         if (rc)
2580                 goto out_fail;
2581
2582         tcon->use_persistent = false;
2583         /* check if SMB2 or later, CIFS does not support persistent handles */
2584         if (ctx->persistent) {
2585                 if (ses->server->vals->protocol_id == 0) {
2586                         cifs_dbg(VFS,
2587                              "SMB3 or later required for persistent handles\n");
2588                         rc = -EOPNOTSUPP;
2589                         goto out_fail;
2590                 } else if (ses->server->capabilities &
2591                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2592                         tcon->use_persistent = true;
2593                 else /* persistent handles requested but not supported */ {
2594                         cifs_dbg(VFS,
2595                                 "Persistent handles not supported on share\n");
2596                         rc = -EOPNOTSUPP;
2597                         goto out_fail;
2598                 }
2599         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2600              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2601              && (ctx->nopersistent == false)) {
2602                 cifs_dbg(FYI, "enabling persistent handles\n");
2603                 tcon->use_persistent = true;
2604         } else if (ctx->resilient) {
2605                 if (ses->server->vals->protocol_id == 0) {
2606                         cifs_dbg(VFS,
2607                              "SMB2.1 or later required for resilient handles\n");
2608                         rc = -EOPNOTSUPP;
2609                         goto out_fail;
2610                 }
2611                 tcon->use_resilient = true;
2612         }
2613
2614         tcon->use_witness = false;
2615         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2616                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2617                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2618                                 /*
2619                                  * Set witness in use flag in first place
2620                                  * to retry registration in the echo task
2621                                  */
2622                                 tcon->use_witness = true;
2623                                 /* And try to register immediately */
2624                                 rc = cifs_swn_register(tcon);
2625                                 if (rc < 0) {
2626                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2627                                         goto out_fail;
2628                                 }
2629                         } else {
2630                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2631                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2632                                 rc = -EOPNOTSUPP;
2633                                 goto out_fail;
2634                         }
2635                 } else {
2636                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2637                         rc = -EOPNOTSUPP;
2638                         goto out_fail;
2639                 }
2640         }
2641
2642         /* If the user really knows what they are doing they can override */
2643         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2644                 if (ctx->cache_ro)
2645                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2646                 else if (ctx->cache_rw)
2647                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2648         }
2649
2650         if (ctx->no_lease) {
2651                 if (ses->server->vals->protocol_id == 0) {
2652                         cifs_dbg(VFS,
2653                                 "SMB2 or later required for nolease option\n");
2654                         rc = -EOPNOTSUPP;
2655                         goto out_fail;
2656                 } else
2657                         tcon->no_lease = ctx->no_lease;
2658         }
2659
2660         /*
2661          * We can have only one retry value for a connection to a share so for
2662          * resources mounted more than once to the same server share the last
2663          * value passed in for the retry flag is used.
2664          */
2665         tcon->retry = ctx->retry;
2666         tcon->nocase = ctx->nocase;
2667         tcon->broken_sparse_sup = ctx->no_sparse;
2668         tcon->max_cached_dirs = ctx->max_cached_dirs;
2669         tcon->nodelete = ctx->nodelete;
2670         tcon->local_lease = ctx->local_lease;
2671         INIT_LIST_HEAD(&tcon->pending_opens);
2672         tcon->status = TID_GOOD;
2673
2674         INIT_DELAYED_WORK(&tcon->query_interfaces,
2675                           smb2_query_server_interfaces);
2676         if (ses->server->dialect >= SMB30_PROT_ID &&
2677             (ses->server->capabilities & SMB2_GLOBAL_CAP_MULTI_CHANNEL)) {
2678                 /* schedule query interfaces poll */
2679                 queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2680                                    (SMB_INTERFACE_POLL_INTERVAL * HZ));
2681         }
2682 #ifdef CONFIG_CIFS_DFS_UPCALL
2683         INIT_DELAYED_WORK(&tcon->dfs_cache_work, dfs_cache_refresh);
2684 #endif
2685         spin_lock(&cifs_tcp_ses_lock);
2686         list_add(&tcon->tcon_list, &ses->tcon_list);
2687         spin_unlock(&cifs_tcp_ses_lock);
2688
2689         return tcon;
2690
2691 out_fail:
2692         tconInfoFree(tcon);
2693         return ERR_PTR(rc);
2694 }
2695
2696 void
2697 cifs_put_tlink(struct tcon_link *tlink)
2698 {
2699         if (!tlink || IS_ERR(tlink))
2700                 return;
2701
2702         if (!atomic_dec_and_test(&tlink->tl_count) ||
2703             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2704                 tlink->tl_time = jiffies;
2705                 return;
2706         }
2707
2708         if (!IS_ERR(tlink_tcon(tlink)))
2709                 cifs_put_tcon(tlink_tcon(tlink));
2710         kfree(tlink);
2711         return;
2712 }
2713
2714 static int
2715 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2716 {
2717         struct cifs_sb_info *old = CIFS_SB(sb);
2718         struct cifs_sb_info *new = mnt_data->cifs_sb;
2719         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2720         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2721
2722         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2723                 return 0;
2724
2725         if (old->mnt_cifs_serverino_autodisabled)
2726                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2727
2728         if (oldflags != newflags)
2729                 return 0;
2730
2731         /*
2732          * We want to share sb only if we don't specify an r/wsize or
2733          * specified r/wsize is greater than or equal to existing one.
2734          */
2735         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2736                 return 0;
2737
2738         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2739                 return 0;
2740
2741         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2742             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2743                 return 0;
2744
2745         if (old->ctx->file_mode != new->ctx->file_mode ||
2746             old->ctx->dir_mode != new->ctx->dir_mode)
2747                 return 0;
2748
2749         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2750                 return 0;
2751
2752         if (old->ctx->acregmax != new->ctx->acregmax)
2753                 return 0;
2754         if (old->ctx->acdirmax != new->ctx->acdirmax)
2755                 return 0;
2756         if (old->ctx->closetimeo != new->ctx->closetimeo)
2757                 return 0;
2758
2759         return 1;
2760 }
2761
2762 static int match_prepath(struct super_block *sb,
2763                          struct cifs_tcon *tcon,
2764                          struct cifs_mnt_data *mnt_data)
2765 {
2766         struct smb3_fs_context *ctx = mnt_data->ctx;
2767         struct cifs_sb_info *old = CIFS_SB(sb);
2768         struct cifs_sb_info *new = mnt_data->cifs_sb;
2769         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2770                 old->prepath;
2771         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2772                 new->prepath;
2773
2774         if (tcon->origin_fullpath &&
2775             dfs_src_pathname_equal(tcon->origin_fullpath, ctx->source))
2776                 return 1;
2777
2778         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2779                 return 1;
2780         else if (!old_set && !new_set)
2781                 return 1;
2782
2783         return 0;
2784 }
2785
2786 int
2787 cifs_match_super(struct super_block *sb, void *data)
2788 {
2789         struct cifs_mnt_data *mnt_data = data;
2790         struct smb3_fs_context *ctx;
2791         struct cifs_sb_info *cifs_sb;
2792         struct TCP_Server_Info *tcp_srv;
2793         struct cifs_ses *ses;
2794         struct cifs_tcon *tcon;
2795         struct tcon_link *tlink;
2796         int rc = 0;
2797
2798         spin_lock(&cifs_tcp_ses_lock);
2799         cifs_sb = CIFS_SB(sb);
2800
2801         /* We do not want to use a superblock that has been shutdown */
2802         if (CIFS_MOUNT_SHUTDOWN & cifs_sb->mnt_cifs_flags) {
2803                 spin_unlock(&cifs_tcp_ses_lock);
2804                 return 0;
2805         }
2806
2807         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2808         if (IS_ERR_OR_NULL(tlink)) {
2809                 pr_warn_once("%s: skip super matching due to bad tlink(%p)\n",
2810                              __func__, tlink);
2811                 spin_unlock(&cifs_tcp_ses_lock);
2812                 return 0;
2813         }
2814         tcon = tlink_tcon(tlink);
2815         ses = tcon->ses;
2816         tcp_srv = ses->server;
2817
2818         ctx = mnt_data->ctx;
2819
2820         spin_lock(&tcp_srv->srv_lock);
2821         spin_lock(&ses->ses_lock);
2822         spin_lock(&ses->chan_lock);
2823         spin_lock(&tcon->tc_lock);
2824         if (!match_server(tcp_srv, ctx, true) ||
2825             !match_session(ses, ctx) ||
2826             !match_tcon(tcon, ctx) ||
2827             !match_prepath(sb, tcon, mnt_data)) {
2828                 rc = 0;
2829                 goto out;
2830         }
2831
2832         rc = compare_mount_options(sb, mnt_data);
2833 out:
2834         spin_unlock(&tcon->tc_lock);
2835         spin_unlock(&ses->chan_lock);
2836         spin_unlock(&ses->ses_lock);
2837         spin_unlock(&tcp_srv->srv_lock);
2838
2839         spin_unlock(&cifs_tcp_ses_lock);
2840         cifs_put_tlink(tlink);
2841         return rc;
2842 }
2843
2844 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2845 static struct lock_class_key cifs_key[2];
2846 static struct lock_class_key cifs_slock_key[2];
2847
2848 static inline void
2849 cifs_reclassify_socket4(struct socket *sock)
2850 {
2851         struct sock *sk = sock->sk;
2852         BUG_ON(!sock_allow_reclassification(sk));
2853         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2854                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2855 }
2856
2857 static inline void
2858 cifs_reclassify_socket6(struct socket *sock)
2859 {
2860         struct sock *sk = sock->sk;
2861         BUG_ON(!sock_allow_reclassification(sk));
2862         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2863                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2864 }
2865 #else
2866 static inline void
2867 cifs_reclassify_socket4(struct socket *sock)
2868 {
2869 }
2870
2871 static inline void
2872 cifs_reclassify_socket6(struct socket *sock)
2873 {
2874 }
2875 #endif
2876
2877 /* See RFC1001 section 14 on representation of Netbios names */
2878 static void rfc1002mangle(char *target, char *source, unsigned int length)
2879 {
2880         unsigned int i, j;
2881
2882         for (i = 0, j = 0; i < (length); i++) {
2883                 /* mask a nibble at a time and encode */
2884                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2885                 target[j+1] = 'A' + (0x0F & source[i]);
2886                 j += 2;
2887         }
2888
2889 }
2890
2891 static int
2892 bind_socket(struct TCP_Server_Info *server)
2893 {
2894         int rc = 0;
2895         if (server->srcaddr.ss_family != AF_UNSPEC) {
2896                 /* Bind to the specified local IP address */
2897                 struct socket *socket = server->ssocket;
2898                 rc = kernel_bind(socket,
2899                                  (struct sockaddr *) &server->srcaddr,
2900                                  sizeof(server->srcaddr));
2901                 if (rc < 0) {
2902                         struct sockaddr_in *saddr4;
2903                         struct sockaddr_in6 *saddr6;
2904                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2905                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2906                         if (saddr6->sin6_family == AF_INET6)
2907                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2908                                          &saddr6->sin6_addr, rc);
2909                         else
2910                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2911                                          &saddr4->sin_addr.s_addr, rc);
2912                 }
2913         }
2914         return rc;
2915 }
2916
2917 static int
2918 ip_rfc1001_connect(struct TCP_Server_Info *server)
2919 {
2920         int rc = 0;
2921         /*
2922          * some servers require RFC1001 sessinit before sending
2923          * negprot - BB check reconnection in case where second
2924          * sessinit is sent but no second negprot
2925          */
2926         struct rfc1002_session_packet req = {};
2927         struct smb_hdr *smb_buf = (struct smb_hdr *)&req;
2928         unsigned int len;
2929
2930         req.trailer.session_req.called_len = sizeof(req.trailer.session_req.called_name);
2931
2932         if (server->server_RFC1001_name[0] != 0)
2933                 rfc1002mangle(req.trailer.session_req.called_name,
2934                               server->server_RFC1001_name,
2935                               RFC1001_NAME_LEN_WITH_NULL);
2936         else
2937                 rfc1002mangle(req.trailer.session_req.called_name,
2938                               DEFAULT_CIFS_CALLED_NAME,
2939                               RFC1001_NAME_LEN_WITH_NULL);
2940
2941         req.trailer.session_req.calling_len = sizeof(req.trailer.session_req.calling_name);
2942
2943         /* calling name ends in null (byte 16) from old smb convention */
2944         if (server->workstation_RFC1001_name[0] != 0)
2945                 rfc1002mangle(req.trailer.session_req.calling_name,
2946                               server->workstation_RFC1001_name,
2947                               RFC1001_NAME_LEN_WITH_NULL);
2948         else
2949                 rfc1002mangle(req.trailer.session_req.calling_name,
2950                               "LINUX_CIFS_CLNT",
2951                               RFC1001_NAME_LEN_WITH_NULL);
2952
2953         /*
2954          * As per rfc1002, @len must be the number of bytes that follows the
2955          * length field of a rfc1002 session request payload.
2956          */
2957         len = sizeof(req) - offsetof(struct rfc1002_session_packet, trailer.session_req);
2958
2959         smb_buf->smb_buf_length = cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | len);
2960         rc = smb_send(server, smb_buf, len);
2961         /*
2962          * RFC1001 layer in at least one server requires very short break before
2963          * negprot presumably because not expecting negprot to follow so fast.
2964          * This is a simple solution that works without complicating the code
2965          * and causes no significant slowing down on mount for everyone else
2966          */
2967         usleep_range(1000, 2000);
2968
2969         return rc;
2970 }
2971
2972 static int
2973 generic_ip_connect(struct TCP_Server_Info *server)
2974 {
2975         struct sockaddr *saddr;
2976         struct socket *socket;
2977         int slen, sfamily;
2978         __be16 sport;
2979         int rc = 0;
2980
2981         saddr = (struct sockaddr *) &server->dstaddr;
2982
2983         if (server->dstaddr.ss_family == AF_INET6) {
2984                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2985
2986                 sport = ipv6->sin6_port;
2987                 slen = sizeof(struct sockaddr_in6);
2988                 sfamily = AF_INET6;
2989                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2990                                 ntohs(sport));
2991         } else {
2992                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2993
2994                 sport = ipv4->sin_port;
2995                 slen = sizeof(struct sockaddr_in);
2996                 sfamily = AF_INET;
2997                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2998                                 ntohs(sport));
2999         }
3000
3001         if (server->ssocket) {
3002                 socket = server->ssocket;
3003         } else {
3004                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
3005                                    IPPROTO_TCP, &server->ssocket, 1);
3006                 if (rc < 0) {
3007                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
3008                         return rc;
3009                 }
3010
3011                 /* BB other socket options to set KEEPALIVE, NODELAY? */
3012                 cifs_dbg(FYI, "Socket created\n");
3013                 socket = server->ssocket;
3014                 socket->sk->sk_allocation = GFP_NOFS;
3015                 socket->sk->sk_use_task_frag = false;
3016                 if (sfamily == AF_INET6)
3017                         cifs_reclassify_socket6(socket);
3018                 else
3019                         cifs_reclassify_socket4(socket);
3020         }
3021
3022         rc = bind_socket(server);
3023         if (rc < 0)
3024                 return rc;
3025
3026         /*
3027          * Eventually check for other socket options to change from
3028          * the default. sock_setsockopt not used because it expects
3029          * user space buffer
3030          */
3031         socket->sk->sk_rcvtimeo = 7 * HZ;
3032         socket->sk->sk_sndtimeo = 5 * HZ;
3033
3034         /* make the bufsizes depend on wsize/rsize and max requests */
3035         if (server->noautotune) {
3036                 if (socket->sk->sk_sndbuf < (200 * 1024))
3037                         socket->sk->sk_sndbuf = 200 * 1024;
3038                 if (socket->sk->sk_rcvbuf < (140 * 1024))
3039                         socket->sk->sk_rcvbuf = 140 * 1024;
3040         }
3041
3042         if (server->tcp_nodelay)
3043                 tcp_sock_set_nodelay(socket->sk);
3044
3045         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
3046                  socket->sk->sk_sndbuf,
3047                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
3048
3049         rc = kernel_connect(socket, saddr, slen,
3050                             server->noblockcnt ? O_NONBLOCK : 0);
3051         /*
3052          * When mounting SMB root file systems, we do not want to block in
3053          * connect. Otherwise bail out and then let cifs_reconnect() perform
3054          * reconnect failover - if possible.
3055          */
3056         if (server->noblockcnt && rc == -EINPROGRESS)
3057                 rc = 0;
3058         if (rc < 0) {
3059                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3060                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3061                 sock_release(socket);
3062                 server->ssocket = NULL;
3063                 return rc;
3064         }
3065         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3066         if (sport == htons(RFC1001_PORT))
3067                 rc = ip_rfc1001_connect(server);
3068
3069         return rc;
3070 }
3071
3072 static int
3073 ip_connect(struct TCP_Server_Info *server)
3074 {
3075         __be16 *sport;
3076         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3077         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3078
3079         if (server->dstaddr.ss_family == AF_INET6)
3080                 sport = &addr6->sin6_port;
3081         else
3082                 sport = &addr->sin_port;
3083
3084         if (*sport == 0) {
3085                 int rc;
3086
3087                 /* try with 445 port at first */
3088                 *sport = htons(CIFS_PORT);
3089
3090                 rc = generic_ip_connect(server);
3091                 if (rc >= 0)
3092                         return rc;
3093
3094                 /* if it failed, try with 139 port */
3095                 *sport = htons(RFC1001_PORT);
3096         }
3097
3098         return generic_ip_connect(server);
3099 }
3100
3101 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3102 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3103                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3104 {
3105         /*
3106          * If we are reconnecting then should we check to see if
3107          * any requested capabilities changed locally e.g. via
3108          * remount but we can not do much about it here
3109          * if they have (even if we could detect it by the following)
3110          * Perhaps we could add a backpointer to array of sb from tcon
3111          * or if we change to make all sb to same share the same
3112          * sb as NFS - then we only have one backpointer to sb.
3113          * What if we wanted to mount the server share twice once with
3114          * and once without posixacls or posix paths?
3115          */
3116         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3117
3118         if (ctx && ctx->no_linux_ext) {
3119                 tcon->fsUnixInfo.Capability = 0;
3120                 tcon->unix_ext = 0; /* Unix Extensions disabled */
3121                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3122                 return;
3123         } else if (ctx)
3124                 tcon->unix_ext = 1; /* Unix Extensions supported */
3125
3126         if (!tcon->unix_ext) {
3127                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3128                 return;
3129         }
3130
3131         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3132                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3133                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3134                 /*
3135                  * check for reconnect case in which we do not
3136                  * want to change the mount behavior if we can avoid it
3137                  */
3138                 if (ctx == NULL) {
3139                         /*
3140                          * turn off POSIX ACL and PATHNAMES if not set
3141                          * originally at mount time
3142                          */
3143                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3144                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3145                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3146                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3147                                         cifs_dbg(VFS, "POSIXPATH support change\n");
3148                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3149                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3150                                 cifs_dbg(VFS, "possible reconnect error\n");
3151                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
3152                         }
3153                 }
3154
3155                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3156                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
3157
3158                 cap &= CIFS_UNIX_CAP_MASK;
3159                 if (ctx && ctx->no_psx_acl)
3160                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3161                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3162                         cifs_dbg(FYI, "negotiated posix acl support\n");
3163                         if (cifs_sb)
3164                                 cifs_sb->mnt_cifs_flags |=
3165                                         CIFS_MOUNT_POSIXACL;
3166                 }
3167
3168                 if (ctx && ctx->posix_paths == 0)
3169                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3170                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3171                         cifs_dbg(FYI, "negotiate posix pathnames\n");
3172                         if (cifs_sb)
3173                                 cifs_sb->mnt_cifs_flags |=
3174                                         CIFS_MOUNT_POSIX_PATHS;
3175                 }
3176
3177                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3178 #ifdef CONFIG_CIFS_DEBUG2
3179                 if (cap & CIFS_UNIX_FCNTL_CAP)
3180                         cifs_dbg(FYI, "FCNTL cap\n");
3181                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3182                         cifs_dbg(FYI, "EXTATTR cap\n");
3183                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3184                         cifs_dbg(FYI, "POSIX path cap\n");
3185                 if (cap & CIFS_UNIX_XATTR_CAP)
3186                         cifs_dbg(FYI, "XATTR cap\n");
3187                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3188                         cifs_dbg(FYI, "POSIX ACL cap\n");
3189                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3190                         cifs_dbg(FYI, "very large read cap\n");
3191                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3192                         cifs_dbg(FYI, "very large write cap\n");
3193                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3194                         cifs_dbg(FYI, "transport encryption cap\n");
3195                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3196                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3197 #endif /* CIFS_DEBUG2 */
3198                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3199                         if (ctx == NULL)
3200                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3201                         else
3202                                 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");
3203
3204                 }
3205         }
3206 }
3207 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3208
3209 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3210 {
3211         struct smb3_fs_context *ctx = cifs_sb->ctx;
3212
3213         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3214
3215         spin_lock_init(&cifs_sb->tlink_tree_lock);
3216         cifs_sb->tlink_tree = RB_ROOT;
3217
3218         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3219                  ctx->file_mode, ctx->dir_mode);
3220
3221         /* this is needed for ASCII cp to Unicode converts */
3222         if (ctx->iocharset == NULL) {
3223                 /* load_nls_default cannot return null */
3224                 cifs_sb->local_nls = load_nls_default();
3225         } else {
3226                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3227                 if (cifs_sb->local_nls == NULL) {
3228                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3229                                  ctx->iocharset);
3230                         return -ELIBACC;
3231                 }
3232         }
3233         ctx->local_nls = cifs_sb->local_nls;
3234
3235         smb3_update_mnt_flags(cifs_sb);
3236
3237         if (ctx->direct_io)
3238                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3239         if (ctx->cache_ro) {
3240                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3241                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3242         } else if (ctx->cache_rw) {
3243                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3244                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3245                                             CIFS_MOUNT_RW_CACHE);
3246         }
3247
3248         if ((ctx->cifs_acl) && (ctx->dynperm))
3249                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3250
3251         if (ctx->prepath) {
3252                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3253                 if (cifs_sb->prepath == NULL)
3254                         return -ENOMEM;
3255                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3256         }
3257
3258         return 0;
3259 }
3260
3261 /* Release all succeed connections */
3262 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3263 {
3264         int rc = 0;
3265
3266         if (mnt_ctx->tcon)
3267                 cifs_put_tcon(mnt_ctx->tcon);
3268         else if (mnt_ctx->ses)
3269                 cifs_put_smb_ses(mnt_ctx->ses);
3270         else if (mnt_ctx->server)
3271                 cifs_put_tcp_session(mnt_ctx->server, 0);
3272         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3273         free_xid(mnt_ctx->xid);
3274 }
3275
3276 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3277 {
3278         struct TCP_Server_Info *server = NULL;
3279         struct smb3_fs_context *ctx;
3280         struct cifs_ses *ses = NULL;
3281         unsigned int xid;
3282         int rc = 0;
3283
3284         xid = get_xid();
3285
3286         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3287                 rc = -EINVAL;
3288                 goto out;
3289         }
3290         ctx = mnt_ctx->fs_ctx;
3291
3292         /* get a reference to a tcp session */
3293         server = cifs_get_tcp_session(ctx, NULL);
3294         if (IS_ERR(server)) {
3295                 rc = PTR_ERR(server);
3296                 server = NULL;
3297                 goto out;
3298         }
3299
3300         /* get a reference to a SMB session */
3301         ses = cifs_get_smb_ses(server, ctx);
3302         if (IS_ERR(ses)) {
3303                 rc = PTR_ERR(ses);
3304                 ses = NULL;
3305                 goto out;
3306         }
3307
3308         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3309                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3310                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3311                 rc = -EOPNOTSUPP;
3312         }
3313
3314 out:
3315         mnt_ctx->xid = xid;
3316         mnt_ctx->server = server;
3317         mnt_ctx->ses = ses;
3318         mnt_ctx->tcon = NULL;
3319
3320         return rc;
3321 }
3322
3323 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3324 {
3325         struct TCP_Server_Info *server;
3326         struct cifs_sb_info *cifs_sb;
3327         struct smb3_fs_context *ctx;
3328         struct cifs_tcon *tcon = NULL;
3329         int rc = 0;
3330
3331         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3332                          !mnt_ctx->cifs_sb)) {
3333                 rc = -EINVAL;
3334                 goto out;
3335         }
3336         server = mnt_ctx->server;
3337         ctx = mnt_ctx->fs_ctx;
3338         cifs_sb = mnt_ctx->cifs_sb;
3339
3340         /* search for existing tcon to this server share */
3341         tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3342         if (IS_ERR(tcon)) {
3343                 rc = PTR_ERR(tcon);
3344                 tcon = NULL;
3345                 goto out;
3346         }
3347
3348         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3349         if (tcon->posix_extensions)
3350                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3351
3352 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3353         /* tell server which Unix caps we support */
3354         if (cap_unix(tcon->ses)) {
3355                 /*
3356                  * reset of caps checks mount to see if unix extensions disabled
3357                  * for just this mount.
3358                  */
3359                 reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3360                 spin_lock(&tcon->ses->server->srv_lock);
3361                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3362                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3363                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3364                         spin_unlock(&tcon->ses->server->srv_lock);
3365                         rc = -EACCES;
3366                         goto out;
3367                 }
3368                 spin_unlock(&tcon->ses->server->srv_lock);
3369         } else
3370 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3371                 tcon->unix_ext = 0; /* server does not support them */
3372
3373         /* do not care if a following call succeed - informational */
3374         if (!tcon->pipe && server->ops->qfs_tcon) {
3375                 server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3376                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3377                         if (tcon->fsDevInfo.DeviceCharacteristics &
3378                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3379                                 cifs_dbg(VFS, "mounted to read only share\n");
3380                         else if ((cifs_sb->mnt_cifs_flags &
3381                                   CIFS_MOUNT_RW_CACHE) == 0)
3382                                 cifs_dbg(VFS, "read only mount of RW share\n");
3383                         /* no need to log a RW mount of a typical RW share */
3384                 }
3385         }
3386
3387         /*
3388          * Clamp the rsize/wsize mount arguments if they are too big for the server
3389          * and set the rsize/wsize to the negotiated values if not passed in by
3390          * the user on mount
3391          */
3392         if ((cifs_sb->ctx->wsize == 0) ||
3393             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3394                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3395         if ((cifs_sb->ctx->rsize == 0) ||
3396             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3397                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3398
3399         /*
3400          * The cookie is initialized from volume info returned above.
3401          * Inside cifs_fscache_get_super_cookie it checks
3402          * that we do not get super cookie twice.
3403          */
3404         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3405                 cifs_fscache_get_super_cookie(tcon);
3406
3407 out:
3408         mnt_ctx->tcon = tcon;
3409         return rc;
3410 }
3411
3412 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3413                              struct cifs_tcon *tcon)
3414 {
3415         struct tcon_link *tlink;
3416
3417         /* hang the tcon off of the superblock */
3418         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3419         if (tlink == NULL)
3420                 return -ENOMEM;
3421
3422         tlink->tl_uid = ses->linux_uid;
3423         tlink->tl_tcon = tcon;
3424         tlink->tl_time = jiffies;
3425         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3426         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3427
3428         cifs_sb->master_tlink = tlink;
3429         spin_lock(&cifs_sb->tlink_tree_lock);
3430         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3431         spin_unlock(&cifs_sb->tlink_tree_lock);
3432
3433         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3434                                 TLINK_IDLE_EXPIRE);
3435         return 0;
3436 }
3437
3438 static int
3439 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3440                                         unsigned int xid,
3441                                         struct cifs_tcon *tcon,
3442                                         struct cifs_sb_info *cifs_sb,
3443                                         char *full_path,
3444                                         int added_treename)
3445 {
3446         int rc;
3447         char *s;
3448         char sep, tmp;
3449         int skip = added_treename ? 1 : 0;
3450
3451         sep = CIFS_DIR_SEP(cifs_sb);
3452         s = full_path;
3453
3454         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3455         while (rc == 0) {
3456                 /* skip separators */
3457                 while (*s == sep)
3458                         s++;
3459                 if (!*s)
3460                         break;
3461                 /* next separator */
3462                 while (*s && *s != sep)
3463                         s++;
3464                 /*
3465                  * if the treename is added, we then have to skip the first
3466                  * part within the separators
3467                  */
3468                 if (skip) {
3469                         skip = 0;
3470                         continue;
3471                 }
3472                 /*
3473                  * temporarily null-terminate the path at the end of
3474                  * the current component
3475                  */
3476                 tmp = *s;
3477                 *s = 0;
3478                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3479                                                      full_path);
3480                 *s = tmp;
3481         }
3482         return rc;
3483 }
3484
3485 /*
3486  * Check if path is remote (i.e. a DFS share).
3487  *
3488  * Return -EREMOTE if it is, otherwise 0 or -errno.
3489  */
3490 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3491 {
3492         int rc;
3493         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3494         struct TCP_Server_Info *server = mnt_ctx->server;
3495         unsigned int xid = mnt_ctx->xid;
3496         struct cifs_tcon *tcon = mnt_ctx->tcon;
3497         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3498         char *full_path;
3499
3500         if (!server->ops->is_path_accessible)
3501                 return -EOPNOTSUPP;
3502
3503         /*
3504          * cifs_build_path_to_root works only when we have a valid tcon
3505          */
3506         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3507                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3508         if (full_path == NULL)
3509                 return -ENOMEM;
3510
3511         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3512
3513         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3514                                              full_path);
3515         if (rc != 0 && rc != -EREMOTE)
3516                 goto out;
3517
3518         if (rc != -EREMOTE) {
3519                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3520                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3521                 if (rc != 0) {
3522                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3523                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3524                         rc = 0;
3525                 }
3526         }
3527
3528 out:
3529         kfree(full_path);
3530         return rc;
3531 }
3532
3533 #ifdef CONFIG_CIFS_DFS_UPCALL
3534 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3535 {
3536         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3537         bool isdfs;
3538         int rc;
3539
3540         INIT_LIST_HEAD(&mnt_ctx.dfs_ses_list);
3541
3542         rc = dfs_mount_share(&mnt_ctx, &isdfs);
3543         if (rc)
3544                 goto error;
3545         if (!isdfs)
3546                 goto out;
3547
3548         /*
3549          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3550          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3551          */
3552         cifs_autodisable_serverino(cifs_sb);
3553         /*
3554          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3555          * that have different prefix paths.
3556          */
3557         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3558         kfree(cifs_sb->prepath);
3559         cifs_sb->prepath = ctx->prepath;
3560         ctx->prepath = NULL;
3561
3562 out:
3563         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3564         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3565         if (rc)
3566                 goto error;
3567
3568         free_xid(mnt_ctx.xid);
3569         return rc;
3570
3571 error:
3572         dfs_put_root_smb_sessions(&mnt_ctx.dfs_ses_list);
3573         cifs_mount_put_conns(&mnt_ctx);
3574         return rc;
3575 }
3576 #else
3577 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3578 {
3579         int rc = 0;
3580         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3581
3582         rc = cifs_mount_get_session(&mnt_ctx);
3583         if (rc)
3584                 goto error;
3585
3586         rc = cifs_mount_get_tcon(&mnt_ctx);
3587         if (rc)
3588                 goto error;
3589
3590         rc = cifs_is_path_remote(&mnt_ctx);
3591         if (rc == -EREMOTE)
3592                 rc = -EOPNOTSUPP;
3593         if (rc)
3594                 goto error;
3595
3596         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3597         if (rc)
3598                 goto error;
3599
3600         free_xid(mnt_ctx.xid);
3601         return rc;
3602
3603 error:
3604         cifs_mount_put_conns(&mnt_ctx);
3605         return rc;
3606 }
3607 #endif
3608
3609 /*
3610  * Issue a TREE_CONNECT request.
3611  */
3612 int
3613 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3614          const char *tree, struct cifs_tcon *tcon,
3615          const struct nls_table *nls_codepage)
3616 {
3617         struct smb_hdr *smb_buffer;
3618         struct smb_hdr *smb_buffer_response;
3619         TCONX_REQ *pSMB;
3620         TCONX_RSP *pSMBr;
3621         unsigned char *bcc_ptr;
3622         int rc = 0;
3623         int length;
3624         __u16 bytes_left, count;
3625
3626         if (ses == NULL)
3627                 return -EIO;
3628
3629         smb_buffer = cifs_buf_get();
3630         if (smb_buffer == NULL)
3631                 return -ENOMEM;
3632
3633         smb_buffer_response = smb_buffer;
3634
3635         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3636                         NULL /*no tid */ , 4 /*wct */ );
3637
3638         smb_buffer->Mid = get_next_mid(ses->server);
3639         smb_buffer->Uid = ses->Suid;
3640         pSMB = (TCONX_REQ *) smb_buffer;
3641         pSMBr = (TCONX_RSP *) smb_buffer_response;
3642
3643         pSMB->AndXCommand = 0xFF;
3644         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3645         bcc_ptr = &pSMB->Password[0];
3646
3647         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3648         *bcc_ptr = 0; /* password is null byte */
3649         bcc_ptr++;              /* skip password */
3650         /* already aligned so no need to do it below */
3651
3652         if (ses->server->sign)
3653                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3654
3655         if (ses->capabilities & CAP_STATUS32) {
3656                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3657         }
3658         if (ses->capabilities & CAP_DFS) {
3659                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3660         }
3661         if (ses->capabilities & CAP_UNICODE) {
3662                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3663                 length =
3664                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3665                         6 /* max utf8 char length in bytes */ *
3666                         (/* server len*/ + 256 /* share len */), nls_codepage);
3667                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3668                 bcc_ptr += 2;   /* skip trailing null */
3669         } else {                /* ASCII */
3670                 strcpy(bcc_ptr, tree);
3671                 bcc_ptr += strlen(tree) + 1;
3672         }
3673         strcpy(bcc_ptr, "?????");
3674         bcc_ptr += strlen("?????");
3675         bcc_ptr += 1;
3676         count = bcc_ptr - &pSMB->Password[0];
3677         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3678         pSMB->ByteCount = cpu_to_le16(count);
3679
3680         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3681                          0);
3682
3683         /* above now done in SendReceive */
3684         if (rc == 0) {
3685                 bool is_unicode;
3686
3687                 tcon->tid = smb_buffer_response->Tid;
3688                 bcc_ptr = pByteArea(smb_buffer_response);
3689                 bytes_left = get_bcc(smb_buffer_response);
3690                 length = strnlen(bcc_ptr, bytes_left - 2);
3691                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3692                         is_unicode = true;
3693                 else
3694                         is_unicode = false;
3695
3696
3697                 /* skip service field (NB: this field is always ASCII) */
3698                 if (length == 3) {
3699                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3700                             (bcc_ptr[2] == 'C')) {
3701                                 cifs_dbg(FYI, "IPC connection\n");
3702                                 tcon->ipc = true;
3703                                 tcon->pipe = true;
3704                         }
3705                 } else if (length == 2) {
3706                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3707                                 /* the most common case */
3708                                 cifs_dbg(FYI, "disk share connection\n");
3709                         }
3710                 }
3711                 bcc_ptr += length + 1;
3712                 bytes_left -= (length + 1);
3713                 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3714
3715                 /* mostly informational -- no need to fail on error here */
3716                 kfree(tcon->nativeFileSystem);
3717                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3718                                                       bytes_left, is_unicode,
3719                                                       nls_codepage);
3720
3721                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3722
3723                 if ((smb_buffer_response->WordCount == 3) ||
3724                          (smb_buffer_response->WordCount == 7))
3725                         /* field is in same location */
3726                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3727                 else
3728                         tcon->Flags = 0;
3729                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3730         }
3731
3732         cifs_buf_release(smb_buffer);
3733         return rc;
3734 }
3735
3736 static void delayed_free(struct rcu_head *p)
3737 {
3738         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3739
3740         unload_nls(cifs_sb->local_nls);
3741         smb3_cleanup_fs_context(cifs_sb->ctx);
3742         kfree(cifs_sb);
3743 }
3744
3745 void
3746 cifs_umount(struct cifs_sb_info *cifs_sb)
3747 {
3748         struct rb_root *root = &cifs_sb->tlink_tree;
3749         struct rb_node *node;
3750         struct tcon_link *tlink;
3751
3752         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3753
3754         spin_lock(&cifs_sb->tlink_tree_lock);
3755         while ((node = rb_first(root))) {
3756                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3757                 cifs_get_tlink(tlink);
3758                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3759                 rb_erase(node, root);
3760
3761                 spin_unlock(&cifs_sb->tlink_tree_lock);
3762                 cifs_put_tlink(tlink);
3763                 spin_lock(&cifs_sb->tlink_tree_lock);
3764         }
3765         spin_unlock(&cifs_sb->tlink_tree_lock);
3766
3767         kfree(cifs_sb->prepath);
3768         call_rcu(&cifs_sb->rcu, delayed_free);
3769 }
3770
3771 int
3772 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3773                         struct TCP_Server_Info *server)
3774 {
3775         int rc = 0;
3776
3777         if (!server->ops->need_neg || !server->ops->negotiate)
3778                 return -ENOSYS;
3779
3780         /* only send once per connect */
3781         spin_lock(&server->srv_lock);
3782         if (server->tcpStatus != CifsGood &&
3783             server->tcpStatus != CifsNew &&
3784             server->tcpStatus != CifsNeedNegotiate) {
3785                 spin_unlock(&server->srv_lock);
3786                 return -EHOSTDOWN;
3787         }
3788
3789         if (!server->ops->need_neg(server) &&
3790             server->tcpStatus == CifsGood) {
3791                 spin_unlock(&server->srv_lock);
3792                 return 0;
3793         }
3794
3795         server->tcpStatus = CifsInNegotiate;
3796         spin_unlock(&server->srv_lock);
3797
3798         rc = server->ops->negotiate(xid, ses, server);
3799         if (rc == 0) {
3800                 spin_lock(&server->srv_lock);
3801                 if (server->tcpStatus == CifsInNegotiate)
3802                         server->tcpStatus = CifsGood;
3803                 else
3804                         rc = -EHOSTDOWN;
3805                 spin_unlock(&server->srv_lock);
3806         } else {
3807                 spin_lock(&server->srv_lock);
3808                 if (server->tcpStatus == CifsInNegotiate)
3809                         server->tcpStatus = CifsNeedNegotiate;
3810                 spin_unlock(&server->srv_lock);
3811         }
3812
3813         return rc;
3814 }
3815
3816 int
3817 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3818                    struct TCP_Server_Info *server,
3819                    struct nls_table *nls_info)
3820 {
3821         int rc = -ENOSYS;
3822         struct TCP_Server_Info *pserver = SERVER_IS_CHAN(server) ? server->primary_server : server;
3823         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&pserver->dstaddr;
3824         struct sockaddr_in *addr = (struct sockaddr_in *)&pserver->dstaddr;
3825         bool is_binding = false;
3826
3827         spin_lock(&ses->ses_lock);
3828         cifs_dbg(FYI, "%s: channel connect bitmap: 0x%lx\n",
3829                  __func__, ses->chans_need_reconnect);
3830
3831         if (ses->ses_status != SES_GOOD &&
3832             ses->ses_status != SES_NEW &&
3833             ses->ses_status != SES_NEED_RECON) {
3834                 spin_unlock(&ses->ses_lock);
3835                 return -EHOSTDOWN;
3836         }
3837
3838         /* only send once per connect */
3839         spin_lock(&ses->chan_lock);
3840         if (CIFS_ALL_CHANS_GOOD(ses)) {
3841                 if (ses->ses_status == SES_NEED_RECON)
3842                         ses->ses_status = SES_GOOD;
3843                 spin_unlock(&ses->chan_lock);
3844                 spin_unlock(&ses->ses_lock);
3845                 return 0;
3846         }
3847
3848         cifs_chan_set_in_reconnect(ses, server);
3849         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3850         spin_unlock(&ses->chan_lock);
3851
3852         if (!is_binding)
3853                 ses->ses_status = SES_IN_SETUP;
3854         spin_unlock(&ses->ses_lock);
3855
3856         /* update ses ip_addr only for primary chan */
3857         if (server == pserver) {
3858                 if (server->dstaddr.ss_family == AF_INET6)
3859                         scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3860                 else
3861                         scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3862         }
3863
3864         if (!is_binding) {
3865                 ses->capabilities = server->capabilities;
3866                 if (!linuxExtEnabled)
3867                         ses->capabilities &= (~server->vals->cap_unix);
3868
3869                 if (ses->auth_key.response) {
3870                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3871                                  ses->auth_key.response);
3872                         kfree_sensitive(ses->auth_key.response);
3873                         ses->auth_key.response = NULL;
3874                         ses->auth_key.len = 0;
3875                 }
3876         }
3877
3878         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3879                  server->sec_mode, server->capabilities, server->timeAdj);
3880
3881         if (server->ops->sess_setup)
3882                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
3883
3884         if (rc) {
3885                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3886                 spin_lock(&ses->ses_lock);
3887                 if (ses->ses_status == SES_IN_SETUP)
3888                         ses->ses_status = SES_NEED_RECON;
3889                 spin_lock(&ses->chan_lock);
3890                 cifs_chan_clear_in_reconnect(ses, server);
3891                 spin_unlock(&ses->chan_lock);
3892                 spin_unlock(&ses->ses_lock);
3893         } else {
3894                 spin_lock(&ses->ses_lock);
3895                 if (ses->ses_status == SES_IN_SETUP)
3896                         ses->ses_status = SES_GOOD;
3897                 spin_lock(&ses->chan_lock);
3898                 cifs_chan_clear_in_reconnect(ses, server);
3899                 cifs_chan_clear_need_reconnect(ses, server);
3900                 spin_unlock(&ses->chan_lock);
3901                 spin_unlock(&ses->ses_lock);
3902         }
3903
3904         return rc;
3905 }
3906
3907 static int
3908 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3909 {
3910         ctx->sectype = ses->sectype;
3911
3912         /* krb5 is special, since we don't need username or pw */
3913         if (ctx->sectype == Kerberos)
3914                 return 0;
3915
3916         return cifs_set_cifscreds(ctx, ses);
3917 }
3918
3919 static struct cifs_tcon *
3920 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3921 {
3922         int rc;
3923         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3924         struct cifs_ses *ses;
3925         struct cifs_tcon *tcon = NULL;
3926         struct smb3_fs_context *ctx;
3927
3928         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3929         if (ctx == NULL)
3930                 return ERR_PTR(-ENOMEM);
3931
3932         ctx->local_nls = cifs_sb->local_nls;
3933         ctx->linux_uid = fsuid;
3934         ctx->cred_uid = fsuid;
3935         ctx->UNC = master_tcon->tree_name;
3936         ctx->retry = master_tcon->retry;
3937         ctx->nocase = master_tcon->nocase;
3938         ctx->nohandlecache = master_tcon->nohandlecache;
3939         ctx->local_lease = master_tcon->local_lease;
3940         ctx->no_lease = master_tcon->no_lease;
3941         ctx->resilient = master_tcon->use_resilient;
3942         ctx->persistent = master_tcon->use_persistent;
3943         ctx->handle_timeout = master_tcon->handle_timeout;
3944         ctx->no_linux_ext = !master_tcon->unix_ext;
3945         ctx->linux_ext = master_tcon->posix_extensions;
3946         ctx->sectype = master_tcon->ses->sectype;
3947         ctx->sign = master_tcon->ses->sign;
3948         ctx->seal = master_tcon->seal;
3949         ctx->witness = master_tcon->use_witness;
3950
3951         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3952         if (rc) {
3953                 tcon = ERR_PTR(rc);
3954                 goto out;
3955         }
3956
3957         /* get a reference for the same TCP session */
3958         spin_lock(&cifs_tcp_ses_lock);
3959         ++master_tcon->ses->server->srv_count;
3960         spin_unlock(&cifs_tcp_ses_lock);
3961
3962         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3963         if (IS_ERR(ses)) {
3964                 tcon = (struct cifs_tcon *)ses;
3965                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3966                 goto out;
3967         }
3968
3969         tcon = cifs_get_tcon(ses, ctx);
3970         if (IS_ERR(tcon)) {
3971                 cifs_put_smb_ses(ses);
3972                 goto out;
3973         }
3974
3975 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3976         if (cap_unix(ses))
3977                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3978 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3979
3980 out:
3981         kfree(ctx->username);
3982         kfree_sensitive(ctx->password);
3983         kfree(ctx);
3984
3985         return tcon;
3986 }
3987
3988 struct cifs_tcon *
3989 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3990 {
3991         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3992 }
3993
3994 /* find and return a tlink with given uid */
3995 static struct tcon_link *
3996 tlink_rb_search(struct rb_root *root, kuid_t uid)
3997 {
3998         struct rb_node *node = root->rb_node;
3999         struct tcon_link *tlink;
4000
4001         while (node) {
4002                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4003
4004                 if (uid_gt(tlink->tl_uid, uid))
4005                         node = node->rb_left;
4006                 else if (uid_lt(tlink->tl_uid, uid))
4007                         node = node->rb_right;
4008                 else
4009                         return tlink;
4010         }
4011         return NULL;
4012 }
4013
4014 /* insert a tcon_link into the tree */
4015 static void
4016 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4017 {
4018         struct rb_node **new = &(root->rb_node), *parent = NULL;
4019         struct tcon_link *tlink;
4020
4021         while (*new) {
4022                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4023                 parent = *new;
4024
4025                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4026                         new = &((*new)->rb_left);
4027                 else
4028                         new = &((*new)->rb_right);
4029         }
4030
4031         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4032         rb_insert_color(&new_tlink->tl_rbnode, root);
4033 }
4034
4035 /*
4036  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4037  * current task.
4038  *
4039  * If the superblock doesn't refer to a multiuser mount, then just return
4040  * the master tcon for the mount.
4041  *
4042  * First, search the rbtree for an existing tcon for this fsuid. If one
4043  * exists, then check to see if it's pending construction. If it is then wait
4044  * for construction to complete. Once it's no longer pending, check to see if
4045  * it failed and either return an error or retry construction, depending on
4046  * the timeout.
4047  *
4048  * If one doesn't exist then insert a new tcon_link struct into the tree and
4049  * try to construct a new one.
4050  */
4051 struct tcon_link *
4052 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4053 {
4054         int ret;
4055         kuid_t fsuid = current_fsuid();
4056         struct tcon_link *tlink, *newtlink;
4057
4058         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4059                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4060
4061         spin_lock(&cifs_sb->tlink_tree_lock);
4062         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4063         if (tlink)
4064                 cifs_get_tlink(tlink);
4065         spin_unlock(&cifs_sb->tlink_tree_lock);
4066
4067         if (tlink == NULL) {
4068                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4069                 if (newtlink == NULL)
4070                         return ERR_PTR(-ENOMEM);
4071                 newtlink->tl_uid = fsuid;
4072                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4073                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4074                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4075                 cifs_get_tlink(newtlink);
4076
4077                 spin_lock(&cifs_sb->tlink_tree_lock);
4078                 /* was one inserted after previous search? */
4079                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4080                 if (tlink) {
4081                         cifs_get_tlink(tlink);
4082                         spin_unlock(&cifs_sb->tlink_tree_lock);
4083                         kfree(newtlink);
4084                         goto wait_for_construction;
4085                 }
4086                 tlink = newtlink;
4087                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4088                 spin_unlock(&cifs_sb->tlink_tree_lock);
4089         } else {
4090 wait_for_construction:
4091                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4092                                   TASK_INTERRUPTIBLE);
4093                 if (ret) {
4094                         cifs_put_tlink(tlink);
4095                         return ERR_PTR(-ERESTARTSYS);
4096                 }
4097
4098                 /* if it's good, return it */
4099                 if (!IS_ERR(tlink->tl_tcon))
4100                         return tlink;
4101
4102                 /* return error if we tried this already recently */
4103                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4104                         cifs_put_tlink(tlink);
4105                         return ERR_PTR(-EACCES);
4106                 }
4107
4108                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4109                         goto wait_for_construction;
4110         }
4111
4112         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4113         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4114         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4115
4116         if (IS_ERR(tlink->tl_tcon)) {
4117                 cifs_put_tlink(tlink);
4118                 return ERR_PTR(-EACCES);
4119         }
4120
4121         return tlink;
4122 }
4123
4124 /*
4125  * periodic workqueue job that scans tcon_tree for a superblock and closes
4126  * out tcons.
4127  */
4128 static void
4129 cifs_prune_tlinks(struct work_struct *work)
4130 {
4131         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4132                                                     prune_tlinks.work);
4133         struct rb_root *root = &cifs_sb->tlink_tree;
4134         struct rb_node *node;
4135         struct rb_node *tmp;
4136         struct tcon_link *tlink;
4137
4138         /*
4139          * Because we drop the spinlock in the loop in order to put the tlink
4140          * it's not guarded against removal of links from the tree. The only
4141          * places that remove entries from the tree are this function and
4142          * umounts. Because this function is non-reentrant and is canceled
4143          * before umount can proceed, this is safe.
4144          */
4145         spin_lock(&cifs_sb->tlink_tree_lock);
4146         node = rb_first(root);
4147         while (node != NULL) {
4148                 tmp = node;
4149                 node = rb_next(tmp);
4150                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4151
4152                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4153                     atomic_read(&tlink->tl_count) != 0 ||
4154                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4155                         continue;
4156
4157                 cifs_get_tlink(tlink);
4158                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4159                 rb_erase(tmp, root);
4160
4161                 spin_unlock(&cifs_sb->tlink_tree_lock);
4162                 cifs_put_tlink(tlink);
4163                 spin_lock(&cifs_sb->tlink_tree_lock);
4164         }
4165         spin_unlock(&cifs_sb->tlink_tree_lock);
4166
4167         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4168                                 TLINK_IDLE_EXPIRE);
4169 }
4170
4171 #ifndef CONFIG_CIFS_DFS_UPCALL
4172 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4173 {
4174         int rc;
4175         const struct smb_version_operations *ops = tcon->ses->server->ops;
4176
4177         /* only send once per connect */
4178         spin_lock(&tcon->tc_lock);
4179         if (tcon->status == TID_GOOD) {
4180                 spin_unlock(&tcon->tc_lock);
4181                 return 0;
4182         }
4183
4184         if (tcon->status != TID_NEW &&
4185             tcon->status != TID_NEED_TCON) {
4186                 spin_unlock(&tcon->tc_lock);
4187                 return -EHOSTDOWN;
4188         }
4189
4190         tcon->status = TID_IN_TCON;
4191         spin_unlock(&tcon->tc_lock);
4192
4193         rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4194         if (rc) {
4195                 spin_lock(&tcon->tc_lock);
4196                 if (tcon->status == TID_IN_TCON)
4197                         tcon->status = TID_NEED_TCON;
4198                 spin_unlock(&tcon->tc_lock);
4199         } else {
4200                 spin_lock(&tcon->tc_lock);
4201                 if (tcon->status == TID_IN_TCON)
4202                         tcon->status = TID_GOOD;
4203                 tcon->need_reconnect = false;
4204                 spin_unlock(&tcon->tc_lock);
4205         }
4206
4207         return rc;
4208 }
4209 #endif