fs/cifs/connect.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/net.h>
  10 #include <linux/string.h>
  11 #include <linux/sched/mm.h>
  12 #include <linux/sched/signal.h>
  13 #include <linux/list.h>
  14 #include <linux/wait.h>
  15 #include <linux/slab.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/ctype.h>
  18 #include <linux/utsname.h>
  19 #include <linux/mempool.h>
  20 #include <linux/delay.h>
  21 #include <linux/completion.h>
  22 #include <linux/kthread.h>
  23 #include <linux/pagevec.h>
  24 #include <linux/freezer.h>
  25 #include <linux/namei.h>
  26 #include <linux/uuid.h>
  27 #include <linux/uaccess.h>
  28 #include <asm/processor.h>
  29 #include <linux/inet.h>
  30 #include <linux/module.h>
  31 #include <keys/user-type.h>
  32 #include <net/ipv6.h>
  33 #include <linux/parser.h>
  34 #include <linux/bvec.h>
  35 #include "cifspdu.h"
  36 #include "cifsglob.h"
  37 #include "cifsproto.h"
  38 #include "cifs_unicode.h"
  39 #include "cifs_debug.h"
  40 #include "cifs_fs_sb.h"
  41 #include "ntlmssp.h"
  42 #include "nterr.h"
  43 #include "rfc1002pdu.h"
  44 #include "fscache.h"
  45 #include "smb2proto.h"
  46 #include "smbdirect.h"
  47 #include "dns_resolve.h"
  48 #ifdef CONFIG_CIFS_DFS_UPCALL
  49 #include "dfs.h"
  50 #include "dfs_cache.h"
  51 #endif
  52 #include "fs_context.h"
  53 #include "cifs_swn.h"
  54
  55 extern mempool_t *cifs_req_poolp;
  56 extern bool disable_legacy_dialects;
  57
  58 /* FIXME: should these be tunable? */
  59 #define TLINK_ERROR_EXPIRE      (1 * HZ)
  60 #define TLINK_IDLE_EXPIRE       (600 * HZ)
  61
  62 /* Drop the connection to not overload the server */
  63 #define NUM_STATUS_IO_TIMEOUT   5
  64
  65 static int ip_connect(struct TCP_Server_Info *server);
  66 static int generic_ip_connect(struct TCP_Server_Info *server);
  67 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  68 static void cifs_prune_tlinks(struct work_struct *work);
  69
  70 /*
  71  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  72  * get their ip addresses changed at some point.
  73  *
  74  * This should be called with server->srv_mutex held.
  75  */
  76 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  77 {
  78         int rc;
  79         int len;
  80         char *unc;
  81         struct sockaddr_storage ss;
  82         time64_t expiry, now;
  83         unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  84
  85         if (!server->hostname)
  86                 return -EINVAL;
  87
  88         /* if server hostname isn't populated, there's nothing to do here */
  89         if (server->hostname[0] == '\0')
  90                 return 0;
  91
  92         len = strlen(server->hostname) + 3;
  93
  94         unc = kmalloc(len, GFP_KERNEL);
  95         if (!unc) {
  96                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
  97                 return -ENOMEM;
  98         }
  99         scnprintf(unc, len, "\\\\%s", server->hostname);
 100
 101         spin_lock(&server->srv_lock);
 102         ss = server->dstaddr;
 103         spin_unlock(&server->srv_lock);
 104
 105         rc = dns_resolve_server_name_to_ip(unc, (struct sockaddr *)&ss, &expiry);
 106         kfree(unc);
 107
 108         if (rc < 0) {
 109                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 110                          __func__, server->hostname, rc);
 111                 goto requeue_resolve;
 112         }
 113
 114         spin_lock(&server->srv_lock);
 115         memcpy(&server->dstaddr, &ss, sizeof(server->dstaddr));
 116         spin_unlock(&server->srv_lock);
 117
 118         now = ktime_get_real_seconds();
 119         if (expiry && expiry > now)
 120                 /* To make sure we don't use the cached entry, retry 1s */
 121                 ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 122
 123 requeue_resolve:
 124         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 125                  __func__, ttl);
 126         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 127
 128         return rc;
 129 }
 130
 131 static void smb2_query_server_interfaces(struct work_struct *work)
 132 {
 133         int rc;
 134         struct cifs_tcon *tcon = container_of(work,
 135                                         struct cifs_tcon,
 136                                         query_interfaces.work);
 137
 138         /*
 139          * query server network interfaces, in case they change
 140          */
 141         rc = SMB3_request_interfaces(0, tcon, false);
 142         if (rc) {
 143                 cifs_dbg(FYI, "%s: failed to query server interfaces: %d\n",
 144                                 __func__, rc);
 145         }
 146
 147         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
 148                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
 149 }
 150
 151 static void cifs_resolve_server(struct work_struct *work)
 152 {
 153         int rc;
 154         struct TCP_Server_Info *server = container_of(work,
 155                                         struct TCP_Server_Info, resolve.work);
 156
 157         cifs_server_lock(server);
 158
 159         /*
 160          * Resolve the hostname again to make sure that IP address is up-to-date.
 161          */
 162         rc = reconn_set_ipaddr_from_hostname(server);
 163         if (rc) {
 164                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 165                                 __func__, rc);
 166         }
 167
 168         cifs_server_unlock(server);
 169 }
 170
 171 /*
 172  * Update the tcpStatus for the server.
 173  * This is used to signal the cifsd thread to call cifs_reconnect
 174  * ONLY cifsd thread should call cifs_reconnect. For any other
 175  * thread, use this function
 176  *
 177  * @server: the tcp ses for which reconnect is needed
 178  * @all_channels: if this needs to be done for all channels
 179  */
 180 void
 181 cifs_signal_cifsd_for_reconnect(struct TCP_Server_Info *server,
 182                                 bool all_channels)
 183 {
 184         struct TCP_Server_Info *pserver;
 185         struct cifs_ses *ses;
 186         int i;
 187
 188         /* If server is a channel, select the primary channel */
 189         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 190
 191         spin_lock(&pserver->srv_lock);
 192         if (!all_channels) {
 193                 pserver->tcpStatus = CifsNeedReconnect;
 194                 spin_unlock(&pserver->srv_lock);
 195                 return;
 196         }
 197         spin_unlock(&pserver->srv_lock);
 198
 199         spin_lock(&cifs_tcp_ses_lock);
 200         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 201                 spin_lock(&ses->chan_lock);
 202                 for (i = 0; i < ses->chan_count; i++) {
 203                         spin_lock(&ses->chans[i].server->srv_lock);
 204                         ses->chans[i].server->tcpStatus = CifsNeedReconnect;
 205                         spin_unlock(&ses->chans[i].server->srv_lock);
 206                 }
 207                 spin_unlock(&ses->chan_lock);
 208         }
 209         spin_unlock(&cifs_tcp_ses_lock);
 210 }
 211
 212 /*
 213  * Mark all sessions and tcons for reconnect.
 214  * IMPORTANT: make sure that this gets called only from
 215  * cifsd thread. For any other thread, use
 216  * cifs_signal_cifsd_for_reconnect
 217  *
 218  * @server: the tcp ses for which reconnect is needed
 219  * @server needs to be previously set to CifsNeedReconnect.
 220  * @mark_smb_session: whether even sessions need to be marked
 221  */
 222 void
 223 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 224                                       bool mark_smb_session)
 225 {
 226         struct TCP_Server_Info *pserver;
 227         struct cifs_ses *ses, *nses;
 228         struct cifs_tcon *tcon;
 229
 230         /*
 231          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 232          * are not used until reconnected.
 233          */
 234         cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 235
 236         /* If server is a channel, select the primary channel */
 237         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 238
 239
 240         spin_lock(&cifs_tcp_ses_lock);
 241         list_for_each_entry_safe(ses, nses, &pserver->smb_ses_list, smb_ses_list) {
 242                 /* check if iface is still active */
 243                 if (!cifs_chan_is_iface_active(ses, server))
 244                         cifs_chan_update_iface(ses, server);
 245
 246                 spin_lock(&ses->chan_lock);
 247                 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
 248                         goto next_session;
 249
 250                 if (mark_smb_session)
 251                         CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 252                 else
 253                         cifs_chan_set_need_reconnect(ses, server);
 254
 255                 /* If all channels need reconnect, then tcon needs reconnect */
 256                 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
 257                         goto next_session;
 258
 259                 ses->ses_status = SES_NEED_RECON;
 260
 261                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 262                         tcon->need_reconnect = true;
 263                         tcon->status = TID_NEED_RECON;
 264                 }
 265                 if (ses->tcon_ipc) {
 266                         ses->tcon_ipc->need_reconnect = true;
 267                         ses->tcon_ipc->status = TID_NEED_RECON;
 268                 }
 269
 270 next_session:
 271                 spin_unlock(&ses->chan_lock);
 272         }
 273         spin_unlock(&cifs_tcp_ses_lock);
 274 }
 275
 276 static void
 277 cifs_abort_connection(struct TCP_Server_Info *server)
 278 {
 279         struct mid_q_entry *mid, *nmid;
 280         struct list_head retry_list;
 281
 282         server->maxBuf = 0;
 283         server->max_read = 0;
 284
 285         /* do not want to be sending data on a socket we are freeing */
 286         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 287         cifs_server_lock(server);
 288         if (server->ssocket) {
 289                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 290                          server->ssocket->flags);
 291                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 292                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 293                          server->ssocket->flags);
 294                 sock_release(server->ssocket);
 295                 server->ssocket = NULL;
 296         }
 297         server->sequence_number = 0;
 298         server->session_estab = false;
 299         kfree_sensitive(server->session_key.response);
 300         server->session_key.response = NULL;
 301         server->session_key.len = 0;
 302         server->lstrp = jiffies;
 303
 304         /* mark submitted MIDs for retry and issue callback */
 305         INIT_LIST_HEAD(&retry_list);
 306         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 307         spin_lock(&server->mid_lock);
 308         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 309                 kref_get(&mid->refcount);
 310                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 311                         mid->mid_state = MID_RETRY_NEEDED;
 312                 list_move(&mid->qhead, &retry_list);
 313                 mid->mid_flags |= MID_DELETED;
 314         }
 315         spin_unlock(&server->mid_lock);
 316         cifs_server_unlock(server);
 317
 318         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 319         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 320                 list_del_init(&mid->qhead);
 321                 mid->callback(mid);
 322                 release_mid(mid);
 323         }
 324
 325         if (cifs_rdma_enabled(server)) {
 326                 cifs_server_lock(server);
 327                 smbd_destroy(server);
 328                 cifs_server_unlock(server);
 329         }
 330 }
 331
 332 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 333 {
 334         spin_lock(&server->srv_lock);
 335         server->nr_targets = num_targets;
 336         if (server->tcpStatus == CifsExiting) {
 337                 /* the demux thread will exit normally next time through the loop */
 338                 spin_unlock(&server->srv_lock);
 339                 wake_up(&server->response_q);
 340                 return false;
 341         }
 342
 343         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 344         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 345                              server->hostname);
 346         server->tcpStatus = CifsNeedReconnect;
 347
 348         spin_unlock(&server->srv_lock);
 349         return true;
 350 }
 351
 352 /*
 353  * cifs tcp session reconnection
 354  *
 355  * mark tcp session as reconnecting so temporarily locked
 356  * mark all smb sessions as reconnecting for tcp session
 357  * reconnect tcp session
 358  * wake up waiters on reconnection? - (not needed currently)
 359  *
 360  * if mark_smb_session is passed as true, unconditionally mark
 361  * the smb session (and tcon) for reconnect as well. This value
 362  * doesn't really matter for non-multichannel scenario.
 363  *
 364  */
 365 static int __cifs_reconnect(struct TCP_Server_Info *server,
 366                             bool mark_smb_session)
 367 {
 368         int rc = 0;
 369
 370         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 371                 return 0;
 372
 373         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 374
 375         cifs_abort_connection(server);
 376
 377         do {
 378                 try_to_freeze();
 379                 cifs_server_lock(server);
 380
 381                 if (!cifs_swn_set_server_dstaddr(server)) {
 382                         /* resolve the hostname again to make sure that IP address is up-to-date */
 383                         rc = reconn_set_ipaddr_from_hostname(server);
 384                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 385                 }
 386
 387                 if (cifs_rdma_enabled(server))
 388                         rc = smbd_reconnect(server);
 389                 else
 390                         rc = generic_ip_connect(server);
 391                 if (rc) {
 392                         cifs_server_unlock(server);
 393                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 394                         msleep(3000);
 395                 } else {
 396                         atomic_inc(&tcpSesReconnectCount);
 397                         set_credits(server, 1);
 398                         spin_lock(&server->srv_lock);
 399                         if (server->tcpStatus != CifsExiting)
 400                                 server->tcpStatus = CifsNeedNegotiate;
 401                         spin_unlock(&server->srv_lock);
 402                         cifs_swn_reset_server_dstaddr(server);
 403                         cifs_server_unlock(server);
 404                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 405                 }
 406         } while (server->tcpStatus == CifsNeedReconnect);
 407
 408         spin_lock(&server->srv_lock);
 409         if (server->tcpStatus == CifsNeedNegotiate)
 410                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 411         spin_unlock(&server->srv_lock);
 412
 413         wake_up(&server->response_q);
 414         return rc;
 415 }
 416
 417 #ifdef CONFIG_CIFS_DFS_UPCALL
 418 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 419 {
 420         int rc;
 421         char *hostname;
 422
 423         if (!cifs_swn_set_server_dstaddr(server)) {
 424                 if (server->hostname != target) {
 425                         hostname = extract_hostname(target);
 426                         if (!IS_ERR(hostname)) {
 427                                 kfree(server->hostname);
 428                                 server->hostname = hostname;
 429                         } else {
 430                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 431                                          __func__, PTR_ERR(hostname));
 432                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 433                                          server->hostname);
 434                         }
 435                 }
 436                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 437                 rc = reconn_set_ipaddr_from_hostname(server);
 438                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 439         }
 440         /* Reconnect the socket */
 441         if (cifs_rdma_enabled(server))
 442                 rc = smbd_reconnect(server);
 443         else
 444                 rc = generic_ip_connect(server);
 445
 446         return rc;
 447 }
 448
 449 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 450                                      struct dfs_cache_tgt_iterator **target_hint)
 451 {
 452         int rc;
 453         struct dfs_cache_tgt_iterator *tit;
 454
 455         *target_hint = NULL;
 456
 457         /* If dfs target list is empty, then reconnect to last server */
 458         tit = dfs_cache_get_tgt_iterator(tl);
 459         if (!tit)
 460                 return __reconnect_target_unlocked(server, server->hostname);
 461
 462         /* Otherwise, try every dfs target in @tl */
 463         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 464                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 465                 if (!rc) {
 466                         *target_hint = tit;
 467                         break;
 468                 }
 469         }
 470         return rc;
 471 }
 472
 473 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 474 {
 475         int rc = 0;
 476         const char *refpath = server->current_fullpath + 1;
 477         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 478         struct dfs_cache_tgt_iterator *target_hint = NULL;
 479         int num_targets = 0;
 480
 481         /*
 482          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 483          *
 484          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 485          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 486          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 487          * refreshing the referral, so, in this case, default it to 1.
 488          */
 489         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 490                 num_targets = dfs_cache_get_nr_tgts(&tl);
 491         if (!num_targets)
 492                 num_targets = 1;
 493
 494         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 495                 return 0;
 496
 497         /*
 498          * Unconditionally mark all sessions & tcons for reconnect as we might be connecting to a
 499          * different server or share during failover.  It could be improved by adding some logic to
 500          * only do that in case it connects to a different server or share, though.
 501          */
 502         cifs_mark_tcp_ses_conns_for_reconnect(server, true);
 503
 504         cifs_abort_connection(server);
 505
 506         do {
 507                 try_to_freeze();
 508                 cifs_server_lock(server);
 509
 510                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 511                 if (rc) {
 512                         /* Failed to reconnect socket */
 513                         cifs_server_unlock(server);
 514                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 515                         msleep(3000);
 516                         continue;
 517                 }
 518                 /*
 519                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 520                  * process waiting for reconnect will know it needs to re-establish session and tcon
 521                  * through the reconnected target server.
 522                  */
 523                 atomic_inc(&tcpSesReconnectCount);
 524                 set_credits(server, 1);
 525                 spin_lock(&server->srv_lock);
 526                 if (server->tcpStatus != CifsExiting)
 527                         server->tcpStatus = CifsNeedNegotiate;
 528                 spin_unlock(&server->srv_lock);
 529                 cifs_swn_reset_server_dstaddr(server);
 530                 cifs_server_unlock(server);
 531                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 532         } while (server->tcpStatus == CifsNeedReconnect);
 533
 534         dfs_cache_noreq_update_tgthint(refpath, target_hint);
 535         dfs_cache_free_tgts(&tl);
 536
 537         /* Need to set up echo worker again once connection has been established */
 538         spin_lock(&server->srv_lock);
 539         if (server->tcpStatus == CifsNeedNegotiate)
 540                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 541         spin_unlock(&server->srv_lock);
 542
 543         wake_up(&server->response_q);
 544         return rc;
 545 }
 546
 547 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 548 {
 549         mutex_lock(&server->refpath_lock);
 550         if (!server->leaf_fullpath) {
 551                 mutex_unlock(&server->refpath_lock);
 552                 return __cifs_reconnect(server, mark_smb_session);
 553         }
 554         mutex_unlock(&server->refpath_lock);
 555
 556         return reconnect_dfs_server(server);
 557 }
 558 #else
 559 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 560 {
 561         return __cifs_reconnect(server, mark_smb_session);
 562 }
 563 #endif
 564
 565 static void
 566 cifs_echo_request(struct work_struct *work)
 567 {
 568         int rc;
 569         struct TCP_Server_Info *server = container_of(work,
 570                                         struct TCP_Server_Info, echo.work);
 571
 572         /*
 573          * We cannot send an echo if it is disabled.
 574          * Also, no need to ping if we got a response recently.
 575          */
 576
 577         if (server->tcpStatus == CifsNeedReconnect ||
 578             server->tcpStatus == CifsExiting ||
 579             server->tcpStatus == CifsNew ||
 580             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 581             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 582                 goto requeue_echo;
 583
 584         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 585         if (rc)
 586                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 587                          server->hostname);
 588
 589         /* Check witness registrations */
 590         cifs_swn_check();
 591
 592 requeue_echo:
 593         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 594 }
 595
 596 static bool
 597 allocate_buffers(struct TCP_Server_Info *server)
 598 {
 599         if (!server->bigbuf) {
 600                 server->bigbuf = (char *)cifs_buf_get();
 601                 if (!server->bigbuf) {
 602                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 603                         msleep(3000);
 604                         /* retry will check if exiting */
 605                         return false;
 606                 }
 607         } else if (server->large_buf) {
 608                 /* we are reusing a dirty large buf, clear its start */
 609                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 610         }
 611
 612         if (!server->smallbuf) {
 613                 server->smallbuf = (char *)cifs_small_buf_get();
 614                 if (!server->smallbuf) {
 615                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 616                         msleep(1000);
 617                         /* retry will check if exiting */
 618                         return false;
 619                 }
 620                 /* beginning of smb buffer is cleared in our buf_get */
 621         } else {
 622                 /* if existing small buf clear beginning */
 623                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 624         }
 625
 626         return true;
 627 }
 628
 629 static bool
 630 server_unresponsive(struct TCP_Server_Info *server)
 631 {
 632         /*
 633          * We need to wait 3 echo intervals to make sure we handle such
 634          * situations right:
 635          * 1s  client sends a normal SMB request
 636          * 2s  client gets a response
 637          * 30s echo workqueue job pops, and decides we got a response recently
 638          *     and don't need to send another
 639          * ...
 640          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 641          *     a response in >60s.
 642          */
 643         spin_lock(&server->srv_lock);
 644         if ((server->tcpStatus == CifsGood ||
 645             server->tcpStatus == CifsNeedNegotiate) &&
 646             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 647             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 648                 spin_unlock(&server->srv_lock);
 649                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 650                          (3 * server->echo_interval) / HZ);
 651                 cifs_reconnect(server, false);
 652                 return true;
 653         }
 654         spin_unlock(&server->srv_lock);
 655
 656         return false;
 657 }
 658
 659 static inline bool
 660 zero_credits(struct TCP_Server_Info *server)
 661 {
 662         int val;
 663
 664         spin_lock(&server->req_lock);
 665         val = server->credits + server->echo_credits + server->oplock_credits;
 666         if (server->in_flight == 0 && val == 0) {
 667                 spin_unlock(&server->req_lock);
 668                 return true;
 669         }
 670         spin_unlock(&server->req_lock);
 671         return false;
 672 }
 673
 674 static int
 675 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 676 {
 677         int length = 0;
 678         int total_read;
 679
 680         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 681                 try_to_freeze();
 682
 683                 /* reconnect if no credits and no requests in flight */
 684                 if (zero_credits(server)) {
 685                         cifs_reconnect(server, false);
 686                         return -ECONNABORTED;
 687                 }
 688
 689                 if (server_unresponsive(server))
 690                         return -ECONNABORTED;
 691                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 692                         length = smbd_recv(server->smbd_conn, smb_msg);
 693                 else
 694                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 695
 696                 spin_lock(&server->srv_lock);
 697                 if (server->tcpStatus == CifsExiting) {
 698                         spin_unlock(&server->srv_lock);
 699                         return -ESHUTDOWN;
 700                 }
 701
 702                 if (server->tcpStatus == CifsNeedReconnect) {
 703                         spin_unlock(&server->srv_lock);
 704                         cifs_reconnect(server, false);
 705                         return -ECONNABORTED;
 706                 }
 707                 spin_unlock(&server->srv_lock);
 708
 709                 if (length == -ERESTARTSYS ||
 710                     length == -EAGAIN ||
 711                     length == -EINTR) {
 712                         /*
 713                          * Minimum sleep to prevent looping, allowing socket
 714                          * to clear and app threads to set tcpStatus
 715                          * CifsNeedReconnect if server hung.
 716                          */
 717                         usleep_range(1000, 2000);
 718                         length = 0;
 719                         continue;
 720                 }
 721
 722                 if (length <= 0) {
 723                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 724                         cifs_reconnect(server, false);
 725                         return -ECONNABORTED;
 726                 }
 727         }
 728         return total_read;
 729 }
 730
 731 int
 732 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 733                       unsigned int to_read)
 734 {
 735         struct msghdr smb_msg = {};
 736         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 737         iov_iter_kvec(&smb_msg.msg_iter, ITER_DEST, &iov, 1, to_read);
 738
 739         return cifs_readv_from_socket(server, &smb_msg);
 740 }
 741
 742 ssize_t
 743 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 744 {
 745         struct msghdr smb_msg = {};
 746
 747         /*
 748          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 749          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 750          *  so little to initialize in struct msghdr
 751          */
 752         iov_iter_discard(&smb_msg.msg_iter, ITER_DEST, to_read);
 753
 754         return cifs_readv_from_socket(server, &smb_msg);
 755 }
 756
 757 int
 758 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 759         unsigned int page_offset, unsigned int to_read)
 760 {
 761         struct msghdr smb_msg = {};
 762         struct bio_vec bv = {
 763                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 764         iov_iter_bvec(&smb_msg.msg_iter, ITER_DEST, &bv, 1, to_read);
 765         return cifs_readv_from_socket(server, &smb_msg);
 766 }
 767
 768 static bool
 769 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 770 {
 771         /*
 772          * The first byte big endian of the length field,
 773          * is actually not part of the length but the type
 774          * with the most common, zero, as regular data.
 775          */
 776         switch (type) {
 777         case RFC1002_SESSION_MESSAGE:
 778                 /* Regular SMB response */
 779                 return true;
 780         case RFC1002_SESSION_KEEP_ALIVE:
 781                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 782                 break;
 783         case RFC1002_POSITIVE_SESSION_RESPONSE:
 784                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 785                 break;
 786         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 787                 /*
 788                  * We get this from Windows 98 instead of an error on
 789                  * SMB negprot response.
 790                  */
 791                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 792                 /* give server a second to clean up */
 793                 msleep(1000);
 794                 /*
 795                  * Always try 445 first on reconnect since we get NACK
 796                  * on some if we ever connected to port 139 (the NACK
 797                  * is since we do not begin with RFC1001 session
 798                  * initialize frame).
 799                  */
 800                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 801                 cifs_reconnect(server, true);
 802                 break;
 803         default:
 804                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 805                 cifs_reconnect(server, true);
 806         }
 807
 808         return false;
 809 }
 810
 811 void
 812 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 813 {
 814 #ifdef CONFIG_CIFS_STATS2
 815         mid->when_received = jiffies;
 816 #endif
 817         spin_lock(&mid->server->mid_lock);
 818         if (!malformed)
 819                 mid->mid_state = MID_RESPONSE_RECEIVED;
 820         else
 821                 mid->mid_state = MID_RESPONSE_MALFORMED;
 822         /*
 823          * Trying to handle/dequeue a mid after the send_recv()
 824          * function has finished processing it is a bug.
 825          */
 826         if (mid->mid_flags & MID_DELETED) {
 827                 spin_unlock(&mid->server->mid_lock);
 828                 pr_warn_once("trying to dequeue a deleted mid\n");
 829         } else {
 830                 list_del_init(&mid->qhead);
 831                 mid->mid_flags |= MID_DELETED;
 832                 spin_unlock(&mid->server->mid_lock);
 833         }
 834 }
 835
 836 static unsigned int
 837 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 838 {
 839         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 840
 841         /*
 842          * SMB1 does not use credits.
 843          */
 844         if (is_smb1(server))
 845                 return 0;
 846
 847         return le16_to_cpu(shdr->CreditRequest);
 848 }
 849
 850 static void
 851 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 852            char *buf, int malformed)
 853 {
 854         if (server->ops->check_trans2 &&
 855             server->ops->check_trans2(mid, server, buf, malformed))
 856                 return;
 857         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 858         mid->resp_buf = buf;
 859         mid->large_buf = server->large_buf;
 860         /* Was previous buf put in mpx struct for multi-rsp? */
 861         if (!mid->multiRsp) {
 862                 /* smb buffer will be freed by user thread */
 863                 if (server->large_buf)
 864                         server->bigbuf = NULL;
 865                 else
 866                         server->smallbuf = NULL;
 867         }
 868         dequeue_mid(mid, malformed);
 869 }
 870
 871 int
 872 cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
 873 {
 874         bool srv_sign_required = server->sec_mode & server->vals->signing_required;
 875         bool srv_sign_enabled = server->sec_mode & server->vals->signing_enabled;
 876         bool mnt_sign_enabled;
 877
 878         /*
 879          * Is signing required by mnt options? If not then check
 880          * global_secflags to see if it is there.
 881          */
 882         if (!mnt_sign_required)
 883                 mnt_sign_required = ((global_secflags & CIFSSEC_MUST_SIGN) ==
 884                                                 CIFSSEC_MUST_SIGN);
 885
 886         /*
 887          * If signing is required then it's automatically enabled too,
 888          * otherwise, check to see if the secflags allow it.
 889          */
 890         mnt_sign_enabled = mnt_sign_required ? mnt_sign_required :
 891                                 (global_secflags & CIFSSEC_MAY_SIGN);
 892
 893         /* If server requires signing, does client allow it? */
 894         if (srv_sign_required) {
 895                 if (!mnt_sign_enabled) {
 896                         cifs_dbg(VFS, "Server requires signing, but it's disabled in SecurityFlags!\n");
 897                         return -EOPNOTSUPP;
 898                 }
 899                 server->sign = true;
 900         }
 901
 902         /* If client requires signing, does server allow it? */
 903         if (mnt_sign_required) {
 904                 if (!srv_sign_enabled) {
 905                         cifs_dbg(VFS, "Server does not support signing!\n");
 906                         return -EOPNOTSUPP;
 907                 }
 908                 server->sign = true;
 909         }
 910
 911         if (cifs_rdma_enabled(server) && server->sign)
 912                 cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled\n");
 913
 914         return 0;
 915 }
 916
 917
 918 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 919 {
 920         int length;
 921
 922         /* take it off the list, if it's not already */
 923         spin_lock(&server->srv_lock);
 924         list_del_init(&server->tcp_ses_list);
 925         spin_unlock(&server->srv_lock);
 926
 927         cancel_delayed_work_sync(&server->echo);
 928         cancel_delayed_work_sync(&server->resolve);
 929
 930         spin_lock(&server->srv_lock);
 931         server->tcpStatus = CifsExiting;
 932         spin_unlock(&server->srv_lock);
 933         wake_up_all(&server->response_q);
 934
 935         /* check if we have blocked requests that need to free */
 936         spin_lock(&server->req_lock);
 937         if (server->credits <= 0)
 938                 server->credits = 1;
 939         spin_unlock(&server->req_lock);
 940         /*
 941          * Although there should not be any requests blocked on this queue it
 942          * can not hurt to be paranoid and try to wake up requests that may
 943          * haven been blocked when more than 50 at time were on the wire to the
 944          * same server - they now will see the session is in exit state and get
 945          * out of SendReceive.
 946          */
 947         wake_up_all(&server->request_q);
 948         /* give those requests time to exit */
 949         msleep(125);
 950         if (cifs_rdma_enabled(server))
 951                 smbd_destroy(server);
 952         if (server->ssocket) {
 953                 sock_release(server->ssocket);
 954                 server->ssocket = NULL;
 955         }
 956
 957         if (!list_empty(&server->pending_mid_q)) {
 958                 struct list_head dispose_list;
 959                 struct mid_q_entry *mid_entry;
 960                 struct list_head *tmp, *tmp2;
 961
 962                 INIT_LIST_HEAD(&dispose_list);
 963                 spin_lock(&server->mid_lock);
 964                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 965                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 966                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 967                         kref_get(&mid_entry->refcount);
 968                         mid_entry->mid_state = MID_SHUTDOWN;
 969                         list_move(&mid_entry->qhead, &dispose_list);
 970                         mid_entry->mid_flags |= MID_DELETED;
 971                 }
 972                 spin_unlock(&server->mid_lock);
 973
 974                 /* now walk dispose list and issue callbacks */
 975                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 976                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 977                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 978                         list_del_init(&mid_entry->qhead);
 979                         mid_entry->callback(mid_entry);
 980                         release_mid(mid_entry);
 981                 }
 982                 /* 1/8th of sec is more than enough time for them to exit */
 983                 msleep(125);
 984         }
 985
 986         if (!list_empty(&server->pending_mid_q)) {
 987                 /*
 988                  * mpx threads have not exited yet give them at least the smb
 989                  * send timeout time for long ops.
 990                  *
 991                  * Due to delays on oplock break requests, we need to wait at
 992                  * least 45 seconds before giving up on a request getting a
 993                  * response and going ahead and killing cifsd.
 994                  */
 995                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 996                 msleep(46000);
 997                 /*
 998                  * If threads still have not exited they are probably never
 999                  * coming home not much else we can do but free the memory.
1000                  */
1001         }
1002
1003 #ifdef CONFIG_CIFS_DFS_UPCALL
1004         kfree(server->origin_fullpath);
1005         kfree(server->leaf_fullpath);
1006 #endif
1007         kfree(server);
1008
1009         length = atomic_dec_return(&tcpSesAllocCount);
1010         if (length > 0)
1011                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1012 }
1013
1014 static int
1015 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1016 {
1017         int length;
1018         char *buf = server->smallbuf;
1019         unsigned int pdu_length = server->pdu_size;
1020
1021         /* make sure this will fit in a large buffer */
1022         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
1023             HEADER_PREAMBLE_SIZE(server)) {
1024                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
1025                 cifs_reconnect(server, true);
1026                 return -ECONNABORTED;
1027         }
1028
1029         /* switch to large buffer if too big for a small one */
1030         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
1031                 server->large_buf = true;
1032                 memcpy(server->bigbuf, buf, server->total_read);
1033                 buf = server->bigbuf;
1034         }
1035
1036         /* now read the rest */
1037         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
1038                                        pdu_length - MID_HEADER_SIZE(server));
1039
1040         if (length < 0)
1041                 return length;
1042         server->total_read += length;
1043
1044         dump_smb(buf, server->total_read);
1045
1046         return cifs_handle_standard(server, mid);
1047 }
1048
1049 int
1050 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
1051 {
1052         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
1053         int rc;
1054
1055         /*
1056          * We know that we received enough to get to the MID as we
1057          * checked the pdu_length earlier. Now check to see
1058          * if the rest of the header is OK.
1059          *
1060          * 48 bytes is enough to display the header and a little bit
1061          * into the payload for debugging purposes.
1062          */
1063         rc = server->ops->check_message(buf, server->total_read, server);
1064         if (rc)
1065                 cifs_dump_mem("Bad SMB: ", buf,
1066                         min_t(unsigned int, server->total_read, 48));
1067
1068         if (server->ops->is_session_expired &&
1069             server->ops->is_session_expired(buf)) {
1070                 cifs_reconnect(server, true);
1071                 return -1;
1072         }
1073
1074         if (server->ops->is_status_pending &&
1075             server->ops->is_status_pending(buf, server))
1076                 return -1;
1077
1078         if (!mid)
1079                 return rc;
1080
1081         handle_mid(mid, server, buf, rc);
1082         return 0;
1083 }
1084
1085 static void
1086 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
1087 {
1088         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
1089         int scredits, in_flight;
1090
1091         /*
1092          * SMB1 does not use credits.
1093          */
1094         if (is_smb1(server))
1095                 return;
1096
1097         if (shdr->CreditRequest) {
1098                 spin_lock(&server->req_lock);
1099                 server->credits += le16_to_cpu(shdr->CreditRequest);
1100                 scredits = server->credits;
1101                 in_flight = server->in_flight;
1102                 spin_unlock(&server->req_lock);
1103                 wake_up(&server->request_q);
1104
1105                 trace_smb3_hdr_credits(server->CurrentMid,
1106                                 server->conn_id, server->hostname, scredits,
1107                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1108                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1109                                 __func__, le16_to_cpu(shdr->CreditRequest),
1110                                 scredits);
1111         }
1112 }
1113
1114
1115 static int
1116 cifs_demultiplex_thread(void *p)
1117 {
1118         int i, num_mids, length;
1119         struct TCP_Server_Info *server = p;
1120         unsigned int pdu_length;
1121         unsigned int next_offset;
1122         char *buf = NULL;
1123         struct task_struct *task_to_wake = NULL;
1124         struct mid_q_entry *mids[MAX_COMPOUND];
1125         char *bufs[MAX_COMPOUND];
1126         unsigned int noreclaim_flag, num_io_timeout = 0;
1127
1128         noreclaim_flag = memalloc_noreclaim_save();
1129         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1130
1131         length = atomic_inc_return(&tcpSesAllocCount);
1132         if (length > 1)
1133                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1134
1135         set_freezable();
1136         allow_kernel_signal(SIGKILL);
1137         while (server->tcpStatus != CifsExiting) {
1138                 if (try_to_freeze())
1139                         continue;
1140
1141                 if (!allocate_buffers(server))
1142                         continue;
1143
1144                 server->large_buf = false;
1145                 buf = server->smallbuf;
1146                 pdu_length = 4; /* enough to get RFC1001 header */
1147
1148                 length = cifs_read_from_socket(server, buf, pdu_length);
1149                 if (length < 0)
1150                         continue;
1151
1152                 if (is_smb1(server))
1153                         server->total_read = length;
1154                 else
1155                         server->total_read = 0;
1156
1157                 /*
1158                  * The right amount was read from socket - 4 bytes,
1159                  * so we can now interpret the length field.
1160                  */
1161                 pdu_length = get_rfc1002_length(buf);
1162
1163                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1164                 if (!is_smb_response(server, buf[0]))
1165                         continue;
1166 next_pdu:
1167                 server->pdu_size = pdu_length;
1168
1169                 /* make sure we have enough to get to the MID */
1170                 if (server->pdu_size < MID_HEADER_SIZE(server)) {
1171                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1172                                  server->pdu_size);
1173                         cifs_reconnect(server, true);
1174                         continue;
1175                 }
1176
1177                 /* read down to the MID */
1178                 length = cifs_read_from_socket(server,
1179                              buf + HEADER_PREAMBLE_SIZE(server),
1180                              MID_HEADER_SIZE(server));
1181                 if (length < 0)
1182                         continue;
1183                 server->total_read += length;
1184
1185                 if (server->ops->next_header) {
1186                         next_offset = server->ops->next_header(buf);
1187                         if (next_offset)
1188                                 server->pdu_size = next_offset;
1189                 }
1190
1191                 memset(mids, 0, sizeof(mids));
1192                 memset(bufs, 0, sizeof(bufs));
1193                 num_mids = 0;
1194
1195                 if (server->ops->is_transform_hdr &&
1196                     server->ops->receive_transform &&
1197                     server->ops->is_transform_hdr(buf)) {
1198                         length = server->ops->receive_transform(server,
1199                                                                 mids,
1200                                                                 bufs,
1201                                                                 &num_mids);
1202                 } else {
1203                         mids[0] = server->ops->find_mid(server, buf);
1204                         bufs[0] = buf;
1205                         num_mids = 1;
1206
1207                         if (!mids[0] || !mids[0]->receive)
1208                                 length = standard_receive3(server, mids[0]);
1209                         else
1210                                 length = mids[0]->receive(server, mids[0]);
1211                 }
1212
1213                 if (length < 0) {
1214                         for (i = 0; i < num_mids; i++)
1215                                 if (mids[i])
1216                                         release_mid(mids[i]);
1217                         continue;
1218                 }
1219
1220                 if (server->ops->is_status_io_timeout &&
1221                     server->ops->is_status_io_timeout(buf)) {
1222                         num_io_timeout++;
1223                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1224                                 cifs_reconnect(server, false);
1225                                 num_io_timeout = 0;
1226                                 continue;
1227                         }
1228                 }
1229
1230                 server->lstrp = jiffies;
1231
1232                 for (i = 0; i < num_mids; i++) {
1233                         if (mids[i] != NULL) {
1234                                 mids[i]->resp_buf_size = server->pdu_size;
1235
1236                                 if (bufs[i] && server->ops->is_network_name_deleted)
1237                                         server->ops->is_network_name_deleted(bufs[i],
1238                                                                         server);
1239
1240                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1241                                         mids[i]->callback(mids[i]);
1242
1243                                 release_mid(mids[i]);
1244                         } else if (server->ops->is_oplock_break &&
1245                                    server->ops->is_oplock_break(bufs[i],
1246                                                                 server)) {
1247                                 smb2_add_credits_from_hdr(bufs[i], server);
1248                                 cifs_dbg(FYI, "Received oplock break\n");
1249                         } else {
1250                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1251                                                 atomic_read(&mid_count));
1252                                 cifs_dump_mem("Received Data is: ", bufs[i],
1253                                               HEADER_SIZE(server));
1254                                 smb2_add_credits_from_hdr(bufs[i], server);
1255 #ifdef CONFIG_CIFS_DEBUG2
1256                                 if (server->ops->dump_detail)
1257                                         server->ops->dump_detail(bufs[i],
1258                                                                  server);
1259                                 cifs_dump_mids(server);
1260 #endif /* CIFS_DEBUG2 */
1261                         }
1262                 }
1263
1264                 if (pdu_length > server->pdu_size) {
1265                         if (!allocate_buffers(server))
1266                                 continue;
1267                         pdu_length -= server->pdu_size;
1268                         server->total_read = 0;
1269                         server->large_buf = false;
1270                         buf = server->smallbuf;
1271                         goto next_pdu;
1272                 }
1273         } /* end while !EXITING */
1274
1275         /* buffer usually freed in free_mid - need to free it here on exit */
1276         cifs_buf_release(server->bigbuf);
1277         if (server->smallbuf) /* no sense logging a debug message if NULL */
1278                 cifs_small_buf_release(server->smallbuf);
1279
1280         task_to_wake = xchg(&server->tsk, NULL);
1281         clean_demultiplex_info(server);
1282
1283         /* if server->tsk was NULL then wait for a signal before exiting */
1284         if (!task_to_wake) {
1285                 set_current_state(TASK_INTERRUPTIBLE);
1286                 while (!signal_pending(current)) {
1287                         schedule();
1288                         set_current_state(TASK_INTERRUPTIBLE);
1289                 }
1290                 set_current_state(TASK_RUNNING);
1291         }
1292
1293         memalloc_noreclaim_restore(noreclaim_flag);
1294         module_put_and_kthread_exit(0);
1295 }
1296
1297 /*
1298  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1299  * if srcaddr is specified and matches the IP address of the rhs argument
1300  */
1301 bool
1302 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1303 {
1304         switch (srcaddr->sa_family) {
1305         case AF_UNSPEC:
1306                 return (rhs->sa_family == AF_UNSPEC);
1307         case AF_INET: {
1308                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1309                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1310                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1311         }
1312         case AF_INET6: {
1313                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1314                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1315                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1316         }
1317         default:
1318                 WARN_ON(1);
1319                 return false; /* don't expect to be here */
1320         }
1321 }
1322
1323 /*
1324  * If no port is specified in addr structure, we try to match with 445 port
1325  * and if it fails - with 139 ports. It should be called only if address
1326  * families of server and addr are equal.
1327  */
1328 static bool
1329 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1330 {
1331         __be16 port, *sport;
1332
1333         /* SMBDirect manages its own ports, don't match it here */
1334         if (server->rdma)
1335                 return true;
1336
1337         switch (addr->sa_family) {
1338         case AF_INET:
1339                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1340                 port = ((struct sockaddr_in *) addr)->sin_port;
1341                 break;
1342         case AF_INET6:
1343                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1344                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1345                 break;
1346         default:
1347                 WARN_ON(1);
1348                 return false;
1349         }
1350
1351         if (!port) {
1352                 port = htons(CIFS_PORT);
1353                 if (port == *sport)
1354                         return true;
1355
1356                 port = htons(RFC1001_PORT);
1357         }
1358
1359         return port == *sport;
1360 }
1361
1362 static bool match_server_address(struct TCP_Server_Info *server, struct sockaddr *addr)
1363 {
1364         switch (addr->sa_family) {
1365         case AF_INET: {
1366                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1367                 struct sockaddr_in *srv_addr4 =
1368                                         (struct sockaddr_in *)&server->dstaddr;
1369
1370                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1371                         return false;
1372                 break;
1373         }
1374         case AF_INET6: {
1375                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1376                 struct sockaddr_in6 *srv_addr6 =
1377                                         (struct sockaddr_in6 *)&server->dstaddr;
1378
1379                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1380                                      &srv_addr6->sin6_addr))
1381                         return false;
1382                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1383                         return false;
1384                 break;
1385         }
1386         default:
1387                 WARN_ON(1);
1388                 return false; /* don't expect to be here */
1389         }
1390
1391         return true;
1392 }
1393
1394 static bool
1395 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1396 {
1397         /*
1398          * The select_sectype function should either return the ctx->sectype
1399          * that was specified, or "Unspecified" if that sectype was not
1400          * compatible with the given NEGOTIATE request.
1401          */
1402         if (server->ops->select_sectype(server, ctx->sectype)
1403              == Unspecified)
1404                 return false;
1405
1406         /*
1407          * Now check if signing mode is acceptable. No need to check
1408          * global_secflags at this point since if MUST_SIGN is set then
1409          * the server->sign had better be too.
1410          */
1411         if (ctx->sign && !server->sign)
1412                 return false;
1413
1414         return true;
1415 }
1416
1417 static bool dfs_src_pathname_equal(const char *s1, const char *s2)
1418 {
1419         if (strlen(s1) != strlen(s2))
1420                 return false;
1421         for (; *s1; s1++, s2++) {
1422                 if (*s1 == '/' || *s1 == '\\') {
1423                         if (*s2 != '/' && *s2 != '\\')
1424                                 return false;
1425                 } else if (tolower(*s1) != tolower(*s2))
1426                         return false;
1427         }
1428         return true;
1429 }
1430
1431 /* this function must be called with srv_lock held */
1432 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx,
1433                         bool dfs_super_cmp)
1434 {
1435         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1436
1437         if (ctx->nosharesock)
1438                 return 0;
1439
1440         /* this server does not share socket */
1441         if (server->nosharesock)
1442                 return 0;
1443
1444         /* If multidialect negotiation see if existing sessions match one */
1445         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1446                 if (server->vals->protocol_id < SMB30_PROT_ID)
1447                         return 0;
1448         } else if (strcmp(ctx->vals->version_string,
1449                    SMBDEFAULT_VERSION_STRING) == 0) {
1450                 if (server->vals->protocol_id < SMB21_PROT_ID)
1451                         return 0;
1452         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1453                 return 0;
1454
1455         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1456                 return 0;
1457
1458         if (!cifs_match_ipaddr((struct sockaddr *)&ctx->srcaddr,
1459                                (struct sockaddr *)&server->srcaddr))
1460                 return 0;
1461         /*
1462          * When matching DFS superblocks, we only check for original source pathname as the
1463          * currently connected target might be different than the one parsed earlier in i.e.
1464          * mount.cifs(8).
1465          */
1466         if (dfs_super_cmp) {
1467                 if (!ctx->source || !server->origin_fullpath ||
1468                     !dfs_src_pathname_equal(server->origin_fullpath, ctx->source))
1469                         return 0;
1470         } else {
1471                 /* Skip addr, hostname and port matching for DFS connections */
1472                 if (server->leaf_fullpath) {
1473                         if (!ctx->leaf_fullpath ||
1474                             strcasecmp(server->leaf_fullpath, ctx->leaf_fullpath))
1475                                 return 0;
1476                 } else if (strcasecmp(server->hostname, ctx->server_hostname) ||
1477                            !match_server_address(server, addr) ||
1478                            !match_port(server, addr)) {
1479                         return 0;
1480                 }
1481         }
1482
1483         if (!match_security(server, ctx))
1484                 return 0;
1485
1486         if (server->echo_interval != ctx->echo_interval * HZ)
1487                 return 0;
1488
1489         if (server->rdma != ctx->rdma)
1490                 return 0;
1491
1492         if (server->ignore_signature != ctx->ignore_signature)
1493                 return 0;
1494
1495         if (server->min_offload != ctx->min_offload)
1496                 return 0;
1497
1498         return 1;
1499 }
1500
1501 struct TCP_Server_Info *
1502 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1503 {
1504         struct TCP_Server_Info *server;
1505
1506         spin_lock(&cifs_tcp_ses_lock);
1507         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1508                 spin_lock(&server->srv_lock);
1509                 /*
1510                  * Skip ses channels since they're only handled in lower layers
1511                  * (e.g. cifs_send_recv).
1512                  */
1513                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx, false)) {
1514                         spin_unlock(&server->srv_lock);
1515                         continue;
1516                 }
1517                 spin_unlock(&server->srv_lock);
1518
1519                 ++server->srv_count;
1520                 spin_unlock(&cifs_tcp_ses_lock);
1521                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1522                 return server;
1523         }
1524         spin_unlock(&cifs_tcp_ses_lock);
1525         return NULL;
1526 }
1527
1528 void
1529 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1530 {
1531         struct task_struct *task;
1532
1533         spin_lock(&cifs_tcp_ses_lock);
1534         if (--server->srv_count > 0) {
1535                 spin_unlock(&cifs_tcp_ses_lock);
1536                 return;
1537         }
1538
1539         /* srv_count can never go negative */
1540         WARN_ON(server->srv_count < 0);
1541
1542         put_net(cifs_net_ns(server));
1543
1544         list_del_init(&server->tcp_ses_list);
1545         spin_unlock(&cifs_tcp_ses_lock);
1546
1547         /* For secondary channels, we pick up ref-count on the primary server */
1548         if (CIFS_SERVER_IS_CHAN(server))
1549                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1550
1551         cancel_delayed_work_sync(&server->echo);
1552         cancel_delayed_work_sync(&server->resolve);
1553
1554         if (from_reconnect)
1555                 /*
1556                  * Avoid deadlock here: reconnect work calls
1557                  * cifs_put_tcp_session() at its end. Need to be sure
1558                  * that reconnect work does nothing with server pointer after
1559                  * that step.
1560                  */
1561                 cancel_delayed_work(&server->reconnect);
1562         else
1563                 cancel_delayed_work_sync(&server->reconnect);
1564
1565         spin_lock(&server->srv_lock);
1566         server->tcpStatus = CifsExiting;
1567         spin_unlock(&server->srv_lock);
1568
1569         cifs_crypto_secmech_release(server);
1570
1571         kfree_sensitive(server->session_key.response);
1572         server->session_key.response = NULL;
1573         server->session_key.len = 0;
1574         kfree(server->hostname);
1575         server->hostname = NULL;
1576
1577         task = xchg(&server->tsk, NULL);
1578         if (task)
1579                 send_sig(SIGKILL, task, 1);
1580 }
1581
1582 struct TCP_Server_Info *
1583 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1584                      struct TCP_Server_Info *primary_server)
1585 {
1586         struct TCP_Server_Info *tcp_ses = NULL;
1587         int rc;
1588
1589         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1590
1591         /* see if we already have a matching tcp_ses */
1592         tcp_ses = cifs_find_tcp_session(ctx);
1593         if (tcp_ses)
1594                 return tcp_ses;
1595
1596         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1597         if (!tcp_ses) {
1598                 rc = -ENOMEM;
1599                 goto out_err;
1600         }
1601
1602         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1603         if (!tcp_ses->hostname) {
1604                 rc = -ENOMEM;
1605                 goto out_err;
1606         }
1607
1608         if (ctx->leaf_fullpath) {
1609                 tcp_ses->leaf_fullpath = kstrdup(ctx->leaf_fullpath, GFP_KERNEL);
1610                 if (!tcp_ses->leaf_fullpath) {
1611                         rc = -ENOMEM;
1612                         goto out_err;
1613                 }
1614                 tcp_ses->current_fullpath = tcp_ses->leaf_fullpath;
1615         }
1616
1617         if (ctx->nosharesock)
1618                 tcp_ses->nosharesock = true;
1619
1620         tcp_ses->ops = ctx->ops;
1621         tcp_ses->vals = ctx->vals;
1622         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1623
1624         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1625         tcp_ses->noblockcnt = ctx->rootfs;
1626         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1627         tcp_ses->noautotune = ctx->noautotune;
1628         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1629         tcp_ses->rdma = ctx->rdma;
1630         tcp_ses->in_flight = 0;
1631         tcp_ses->max_in_flight = 0;
1632         tcp_ses->credits = 1;
1633         if (primary_server) {
1634                 spin_lock(&cifs_tcp_ses_lock);
1635                 ++primary_server->srv_count;
1636                 spin_unlock(&cifs_tcp_ses_lock);
1637                 tcp_ses->primary_server = primary_server;
1638         }
1639         init_waitqueue_head(&tcp_ses->response_q);
1640         init_waitqueue_head(&tcp_ses->request_q);
1641         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1642         mutex_init(&tcp_ses->_srv_mutex);
1643         memcpy(tcp_ses->workstation_RFC1001_name,
1644                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1645         memcpy(tcp_ses->server_RFC1001_name,
1646                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1647         tcp_ses->session_estab = false;
1648         tcp_ses->sequence_number = 0;
1649         tcp_ses->reconnect_instance = 1;
1650         tcp_ses->lstrp = jiffies;
1651         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1652         spin_lock_init(&tcp_ses->req_lock);
1653         spin_lock_init(&tcp_ses->srv_lock);
1654         spin_lock_init(&tcp_ses->mid_lock);
1655         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1656         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1657         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1658         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1659         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1660         mutex_init(&tcp_ses->reconnect_mutex);
1661 #ifdef CONFIG_CIFS_DFS_UPCALL
1662         mutex_init(&tcp_ses->refpath_lock);
1663 #endif
1664         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1665                sizeof(tcp_ses->srcaddr));
1666         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1667                 sizeof(tcp_ses->dstaddr));
1668         if (ctx->use_client_guid)
1669                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1670                        SMB2_CLIENT_GUID_SIZE);
1671         else
1672                 generate_random_uuid(tcp_ses->client_guid);
1673         /*
1674          * at this point we are the only ones with the pointer
1675          * to the struct since the kernel thread not created yet
1676          * no need to spinlock this init of tcpStatus or srv_count
1677          */
1678         tcp_ses->tcpStatus = CifsNew;
1679         ++tcp_ses->srv_count;
1680
1681         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1682                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1683                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1684         else
1685                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1686         if (tcp_ses->rdma) {
1687 #ifndef CONFIG_CIFS_SMB_DIRECT
1688                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1689                 rc = -ENOENT;
1690                 goto out_err_crypto_release;
1691 #endif
1692                 tcp_ses->smbd_conn = smbd_get_connection(
1693                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1694                 if (tcp_ses->smbd_conn) {
1695                         cifs_dbg(VFS, "RDMA transport established\n");
1696                         rc = 0;
1697                         goto smbd_connected;
1698                 } else {
1699                         rc = -ENOENT;
1700                         goto out_err_crypto_release;
1701                 }
1702         }
1703         rc = ip_connect(tcp_ses);
1704         if (rc < 0) {
1705                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1706                 goto out_err_crypto_release;
1707         }
1708 smbd_connected:
1709         /*
1710          * since we're in a cifs function already, we know that
1711          * this will succeed. No need for try_module_get().
1712          */
1713         __module_get(THIS_MODULE);
1714         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1715                                   tcp_ses, "cifsd");
1716         if (IS_ERR(tcp_ses->tsk)) {
1717                 rc = PTR_ERR(tcp_ses->tsk);
1718                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1719                 module_put(THIS_MODULE);
1720                 goto out_err_crypto_release;
1721         }
1722         tcp_ses->min_offload = ctx->min_offload;
1723         /*
1724          * at this point we are the only ones with the pointer
1725          * to the struct since the kernel thread not created yet
1726          * no need to spinlock this update of tcpStatus
1727          */
1728         spin_lock(&tcp_ses->srv_lock);
1729         tcp_ses->tcpStatus = CifsNeedNegotiate;
1730         spin_unlock(&tcp_ses->srv_lock);
1731
1732         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1733                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1734         else
1735                 tcp_ses->max_credits = ctx->max_credits;
1736
1737         tcp_ses->nr_targets = 1;
1738         tcp_ses->ignore_signature = ctx->ignore_signature;
1739         /* thread spawned, put it on the list */
1740         spin_lock(&cifs_tcp_ses_lock);
1741         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1742         spin_unlock(&cifs_tcp_ses_lock);
1743
1744         /* queue echo request delayed work */
1745         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1746
1747         /* queue dns resolution delayed work */
1748         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1749                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1750
1751         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1752
1753         return tcp_ses;
1754
1755 out_err_crypto_release:
1756         cifs_crypto_secmech_release(tcp_ses);
1757
1758         put_net(cifs_net_ns(tcp_ses));
1759
1760 out_err:
1761         if (tcp_ses) {
1762                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1763                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1764                 kfree(tcp_ses->hostname);
1765                 kfree(tcp_ses->leaf_fullpath);
1766                 if (tcp_ses->ssocket)
1767                         sock_release(tcp_ses->ssocket);
1768                 kfree(tcp_ses);
1769         }
1770         return ERR_PTR(rc);
1771 }
1772
1773 /* this function must be called with ses_lock held */
1774 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1775 {
1776         if (ctx->sectype != Unspecified &&
1777             ctx->sectype != ses->sectype)
1778                 return 0;
1779
1780         /*
1781          * If an existing session is limited to less channels than
1782          * requested, it should not be reused
1783          */
1784         spin_lock(&ses->chan_lock);
1785         if (ses->chan_max < ctx->max_channels) {
1786                 spin_unlock(&ses->chan_lock);
1787                 return 0;
1788         }
1789         spin_unlock(&ses->chan_lock);
1790
1791         switch (ses->sectype) {
1792         case Kerberos:
1793                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1794                         return 0;
1795                 break;
1796         default:
1797                 /* NULL username means anonymous session */
1798                 if (ses->user_name == NULL) {
1799                         if (!ctx->nullauth)
1800                                 return 0;
1801                         break;
1802                 }
1803
1804                 /* anything else takes username/password */
1805                 if (strncmp(ses->user_name,
1806                             ctx->username ? ctx->username : "",
1807                             CIFS_MAX_USERNAME_LEN))
1808                         return 0;
1809                 if ((ctx->username && strlen(ctx->username) != 0) &&
1810                     ses->password != NULL &&
1811                     strncmp(ses->password,
1812                             ctx->password ? ctx->password : "",
1813                             CIFS_MAX_PASSWORD_LEN))
1814                         return 0;
1815         }
1816         return 1;
1817 }
1818
1819 /**
1820  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1821  * @ses: smb session to issue the request on
1822  * @ctx: the superblock configuration context to use for building the
1823  *       new tree connection for the IPC (interprocess communication RPC)
1824  *
1825  * A new IPC connection is made and stored in the session
1826  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1827  */
1828 static int
1829 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1830 {
1831         int rc = 0, xid;
1832         struct cifs_tcon *tcon;
1833         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1834         bool seal = false;
1835         struct TCP_Server_Info *server = ses->server;
1836
1837         /*
1838          * If the mount request that resulted in the creation of the
1839          * session requires encryption, force IPC to be encrypted too.
1840          */
1841         if (ctx->seal) {
1842                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1843                         seal = true;
1844                 else {
1845                         cifs_server_dbg(VFS,
1846                                  "IPC: server doesn't support encryption\n");
1847                         return -EOPNOTSUPP;
1848                 }
1849         }
1850
1851         tcon = tconInfoAlloc();
1852         if (tcon == NULL)
1853                 return -ENOMEM;
1854
1855         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1856
1857         xid = get_xid();
1858         tcon->ses = ses;
1859         tcon->ipc = true;
1860         tcon->seal = seal;
1861         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1862         free_xid(xid);
1863
1864         if (rc) {
1865                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1866                 tconInfoFree(tcon);
1867                 goto out;
1868         }
1869
1870         cifs_dbg(FYI, "IPC tcon rc=%d ipc tid=0x%x\n", rc, tcon->tid);
1871
1872         spin_lock(&tcon->tc_lock);
1873         tcon->status = TID_GOOD;
1874         spin_unlock(&tcon->tc_lock);
1875         ses->tcon_ipc = tcon;
1876 out:
1877         return rc;
1878 }
1879
1880 /**
1881  * cifs_free_ipc - helper to release the session IPC tcon
1882  * @ses: smb session to unmount the IPC from
1883  *
1884  * Needs to be called everytime a session is destroyed.
1885  *
1886  * On session close, the IPC is closed and the server must release all tcons of the session.
1887  * No need to send a tree disconnect here.
1888  *
1889  * Besides, it will make the server to not close durable and resilient files on session close, as
1890  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1891  */
1892 static int
1893 cifs_free_ipc(struct cifs_ses *ses)
1894 {
1895         struct cifs_tcon *tcon = ses->tcon_ipc;
1896
1897         if (tcon == NULL)
1898                 return 0;
1899
1900         tconInfoFree(tcon);
1901         ses->tcon_ipc = NULL;
1902         return 0;
1903 }
1904
1905 static struct cifs_ses *
1906 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1907 {
1908         struct cifs_ses *ses;
1909
1910         spin_lock(&cifs_tcp_ses_lock);
1911         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1912                 spin_lock(&ses->ses_lock);
1913                 if (ses->ses_status == SES_EXITING) {
1914                         spin_unlock(&ses->ses_lock);
1915                         continue;
1916                 }
1917                 if (!match_session(ses, ctx)) {
1918                         spin_unlock(&ses->ses_lock);
1919                         continue;
1920                 }
1921                 spin_unlock(&ses->ses_lock);
1922
1923                 ++ses->ses_count;
1924                 spin_unlock(&cifs_tcp_ses_lock);
1925                 return ses;
1926         }
1927         spin_unlock(&cifs_tcp_ses_lock);
1928         return NULL;
1929 }
1930
1931 void cifs_put_smb_ses(struct cifs_ses *ses)
1932 {
1933         unsigned int rc, xid;
1934         unsigned int chan_count;
1935         struct TCP_Server_Info *server = ses->server;
1936
1937         spin_lock(&ses->ses_lock);
1938         if (ses->ses_status == SES_EXITING) {
1939                 spin_unlock(&ses->ses_lock);
1940                 return;
1941         }
1942         spin_unlock(&ses->ses_lock);
1943
1944         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1945         cifs_dbg(FYI,
1946                  "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->tree_name : "NONE");
1947
1948         spin_lock(&cifs_tcp_ses_lock);
1949         if (--ses->ses_count > 0) {
1950                 spin_unlock(&cifs_tcp_ses_lock);
1951                 return;
1952         }
1953         spin_unlock(&cifs_tcp_ses_lock);
1954
1955         /* ses_count can never go negative */
1956         WARN_ON(ses->ses_count < 0);
1957
1958         if (ses->ses_status == SES_GOOD)
1959                 ses->ses_status = SES_EXITING;
1960
1961         cifs_free_ipc(ses);
1962
1963         if (ses->ses_status == SES_EXITING && server->ops->logoff) {
1964                 xid = get_xid();
1965                 rc = server->ops->logoff(xid, ses);
1966                 if (rc)
1967                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1968                                 __func__, rc);
1969                 _free_xid(xid);
1970         }
1971
1972         spin_lock(&cifs_tcp_ses_lock);
1973         list_del_init(&ses->smb_ses_list);
1974         spin_unlock(&cifs_tcp_ses_lock);
1975
1976         chan_count = ses->chan_count;
1977
1978         /* close any extra channels */
1979         if (chan_count > 1) {
1980                 int i;
1981
1982                 for (i = 1; i < chan_count; i++) {
1983                         if (ses->chans[i].iface) {
1984                                 kref_put(&ses->chans[i].iface->refcount, release_iface);
1985                                 ses->chans[i].iface = NULL;
1986                         }
1987                         cifs_put_tcp_session(ses->chans[i].server, 0);
1988                         ses->chans[i].server = NULL;
1989                 }
1990         }
1991
1992         sesInfoFree(ses);
1993         cifs_put_tcp_session(server, 0);
1994 }
1995
1996 #ifdef CONFIG_KEYS
1997
1998 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1999 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
2000
2001 /* Populate username and pw fields from keyring if possible */
2002 static int
2003 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
2004 {
2005         int rc = 0;
2006         int is_domain = 0;
2007         const char *delim, *payload;
2008         char *desc;
2009         ssize_t len;
2010         struct key *key;
2011         struct TCP_Server_Info *server = ses->server;
2012         struct sockaddr_in *sa;
2013         struct sockaddr_in6 *sa6;
2014         const struct user_key_payload *upayload;
2015
2016         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
2017         if (!desc)
2018                 return -ENOMEM;
2019
2020         /* try to find an address key first */
2021         switch (server->dstaddr.ss_family) {
2022         case AF_INET:
2023                 sa = (struct sockaddr_in *)&server->dstaddr;
2024                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
2025                 break;
2026         case AF_INET6:
2027                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
2028                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
2029                 break;
2030         default:
2031                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
2032                          server->dstaddr.ss_family);
2033                 rc = -EINVAL;
2034                 goto out_err;
2035         }
2036
2037         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2038         key = request_key(&key_type_logon, desc, "");
2039         if (IS_ERR(key)) {
2040                 if (!ses->domainName) {
2041                         cifs_dbg(FYI, "domainName is NULL\n");
2042                         rc = PTR_ERR(key);
2043                         goto out_err;
2044                 }
2045
2046                 /* didn't work, try to find a domain key */
2047                 sprintf(desc, "cifs:d:%s", ses->domainName);
2048                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
2049                 key = request_key(&key_type_logon, desc, "");
2050                 if (IS_ERR(key)) {
2051                         rc = PTR_ERR(key);
2052                         goto out_err;
2053                 }
2054                 is_domain = 1;
2055         }
2056
2057         down_read(&key->sem);
2058         upayload = user_key_payload_locked(key);
2059         if (IS_ERR_OR_NULL(upayload)) {
2060                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
2061                 goto out_key_put;
2062         }
2063
2064         /* find first : in payload */
2065         payload = upayload->data;
2066         delim = strnchr(payload, upayload->datalen, ':');
2067         cifs_dbg(FYI, "payload=%s\n", payload);
2068         if (!delim) {
2069                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
2070                          upayload->datalen);
2071                 rc = -EINVAL;
2072                 goto out_key_put;
2073         }
2074
2075         len = delim - payload;
2076         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
2077                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
2078                          len);
2079                 rc = -EINVAL;
2080                 goto out_key_put;
2081         }
2082
2083         ctx->username = kstrndup(payload, len, GFP_KERNEL);
2084         if (!ctx->username) {
2085                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
2086                          len);
2087                 rc = -ENOMEM;
2088                 goto out_key_put;
2089         }
2090         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
2091
2092         len = key->datalen - (len + 1);
2093         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
2094                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
2095                 rc = -EINVAL;
2096                 kfree(ctx->username);
2097                 ctx->username = NULL;
2098                 goto out_key_put;
2099         }
2100
2101         ++delim;
2102         ctx->password = kstrndup(delim, len, GFP_KERNEL);
2103         if (!ctx->password) {
2104                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
2105                          len);
2106                 rc = -ENOMEM;
2107                 kfree(ctx->username);
2108                 ctx->username = NULL;
2109                 goto out_key_put;
2110         }
2111
2112         /*
2113          * If we have a domain key then we must set the domainName in the
2114          * for the request.
2115          */
2116         if (is_domain && ses->domainName) {
2117                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
2118                 if (!ctx->domainname) {
2119                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
2120                                  len);
2121                         rc = -ENOMEM;
2122                         kfree(ctx->username);
2123                         ctx->username = NULL;
2124                         kfree_sensitive(ctx->password);
2125                         ctx->password = NULL;
2126                         goto out_key_put;
2127                 }
2128         }
2129
2130         strscpy(ctx->workstation_name, ses->workstation_name, sizeof(ctx->workstation_name));
2131
2132 out_key_put:
2133         up_read(&key->sem);
2134         key_put(key);
2135 out_err:
2136         kfree(desc);
2137         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2138         return rc;
2139 }
2140 #else /* ! CONFIG_KEYS */
2141 static inline int
2142 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2143                    struct cifs_ses *ses __attribute__((unused)))
2144 {
2145         return -ENOSYS;
2146 }
2147 #endif /* CONFIG_KEYS */
2148
2149 /**
2150  * cifs_get_smb_ses - get a session matching @ctx data from @server
2151  * @server: server to setup the session to
2152  * @ctx: superblock configuration context to use to setup the session
2153  *
2154  * This function assumes it is being called from cifs_mount() where we
2155  * already got a server reference (server refcount +1). See
2156  * cifs_get_tcon() for refcount explanations.
2157  */
2158 struct cifs_ses *
2159 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2160 {
2161         int rc = 0;
2162         unsigned int xid;
2163         struct cifs_ses *ses;
2164         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2165         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2166
2167         xid = get_xid();
2168
2169         ses = cifs_find_smb_ses(server, ctx);
2170         if (ses) {
2171                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2172                          ses->ses_status);
2173
2174                 spin_lock(&ses->chan_lock);
2175                 if (cifs_chan_needs_reconnect(ses, server)) {
2176                         spin_unlock(&ses->chan_lock);
2177                         cifs_dbg(FYI, "Session needs reconnect\n");
2178
2179                         mutex_lock(&ses->session_mutex);
2180                         rc = cifs_negotiate_protocol(xid, ses, server);
2181                         if (rc) {
2182                                 mutex_unlock(&ses->session_mutex);
2183                                 /* problem -- put our ses reference */
2184                                 cifs_put_smb_ses(ses);
2185                                 free_xid(xid);
2186                                 return ERR_PTR(rc);
2187                         }
2188
2189                         rc = cifs_setup_session(xid, ses, server,
2190                                                 ctx->local_nls);
2191                         if (rc) {
2192                                 mutex_unlock(&ses->session_mutex);
2193                                 /* problem -- put our reference */
2194                                 cifs_put_smb_ses(ses);
2195                                 free_xid(xid);
2196                                 return ERR_PTR(rc);
2197                         }
2198                         mutex_unlock(&ses->session_mutex);
2199
2200                         spin_lock(&ses->chan_lock);
2201                 }
2202                 spin_unlock(&ses->chan_lock);
2203
2204                 /* existing SMB ses has a server reference already */
2205                 cifs_put_tcp_session(server, 0);
2206                 free_xid(xid);
2207                 return ses;
2208         }
2209
2210         rc = -ENOMEM;
2211
2212         cifs_dbg(FYI, "Existing smb sess not found\n");
2213         ses = sesInfoAlloc();
2214         if (ses == NULL)
2215                 goto get_ses_fail;
2216
2217         /* new SMB session uses our server ref */
2218         ses->server = server;
2219         if (server->dstaddr.ss_family == AF_INET6)
2220                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2221         else
2222                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2223
2224         if (ctx->username) {
2225                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2226                 if (!ses->user_name)
2227                         goto get_ses_fail;
2228         }
2229
2230         /* ctx->password freed at unmount */
2231         if (ctx->password) {
2232                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2233                 if (!ses->password)
2234                         goto get_ses_fail;
2235         }
2236         if (ctx->domainname) {
2237                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2238                 if (!ses->domainName)
2239                         goto get_ses_fail;
2240         }
2241
2242         strscpy(ses->workstation_name, ctx->workstation_name, sizeof(ses->workstation_name));
2243
2244         if (ctx->domainauto)
2245                 ses->domainAuto = ctx->domainauto;
2246         ses->cred_uid = ctx->cred_uid;
2247         ses->linux_uid = ctx->linux_uid;
2248
2249         ses->sectype = ctx->sectype;
2250         ses->sign = ctx->sign;
2251
2252         /* add server as first channel */
2253         spin_lock(&ses->chan_lock);
2254         ses->chans[0].server = server;
2255         ses->chan_count = 1;
2256         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2257         ses->chans_need_reconnect = 1;
2258         spin_unlock(&ses->chan_lock);
2259
2260         mutex_lock(&ses->session_mutex);
2261         rc = cifs_negotiate_protocol(xid, ses, server);
2262         if (!rc)
2263                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2264         mutex_unlock(&ses->session_mutex);
2265
2266         /* each channel uses a different signing key */
2267         spin_lock(&ses->chan_lock);
2268         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2269                sizeof(ses->smb3signingkey));
2270         spin_unlock(&ses->chan_lock);
2271
2272         if (rc)
2273                 goto get_ses_fail;
2274
2275         /*
2276          * success, put it on the list and add it as first channel
2277          * note: the session becomes active soon after this. So you'll
2278          * need to lock before changing something in the session.
2279          */
2280         spin_lock(&cifs_tcp_ses_lock);
2281         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2282         spin_unlock(&cifs_tcp_ses_lock);
2283
2284         cifs_setup_ipc(ses, ctx);
2285
2286         free_xid(xid);
2287
2288         return ses;
2289
2290 get_ses_fail:
2291         sesInfoFree(ses);
2292         free_xid(xid);
2293         return ERR_PTR(rc);
2294 }
2295
2296 /* this function must be called with tc_lock held */
2297 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx, bool dfs_super_cmp)
2298 {
2299         if (tcon->status == TID_EXITING)
2300                 return 0;
2301         /* Skip UNC validation when matching DFS superblocks */
2302         if (!dfs_super_cmp && strncmp(tcon->tree_name, ctx->UNC, MAX_TREE_SIZE))
2303                 return 0;
2304         if (tcon->seal != ctx->seal)
2305                 return 0;
2306         if (tcon->snapshot_time != ctx->snapshot_time)
2307                 return 0;
2308         if (tcon->handle_timeout != ctx->handle_timeout)
2309                 return 0;
2310         if (tcon->no_lease != ctx->no_lease)
2311                 return 0;
2312         if (tcon->nodelete != ctx->nodelete)
2313                 return 0;
2314         return 1;
2315 }
2316
2317 static struct cifs_tcon *
2318 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2319 {
2320         struct cifs_tcon *tcon;
2321
2322         spin_lock(&cifs_tcp_ses_lock);
2323         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
2324                 spin_lock(&tcon->tc_lock);
2325                 if (!match_tcon(tcon, ctx, false)) {
2326                         spin_unlock(&tcon->tc_lock);
2327                         continue;
2328                 }
2329                 ++tcon->tc_count;
2330                 spin_unlock(&tcon->tc_lock);
2331                 spin_unlock(&cifs_tcp_ses_lock);
2332                 return tcon;
2333         }
2334         spin_unlock(&cifs_tcp_ses_lock);
2335         return NULL;
2336 }
2337
2338 void
2339 cifs_put_tcon(struct cifs_tcon *tcon)
2340 {
2341         unsigned int xid;
2342         struct cifs_ses *ses;
2343
2344         /*
2345          * IPC tcon share the lifetime of their session and are
2346          * destroyed in the session put function
2347          */
2348         if (tcon == NULL || tcon->ipc)
2349                 return;
2350
2351         ses = tcon->ses;
2352         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2353         spin_lock(&cifs_tcp_ses_lock);
2354         spin_lock(&tcon->tc_lock);
2355         if (--tcon->tc_count > 0) {
2356                 spin_unlock(&tcon->tc_lock);
2357                 spin_unlock(&cifs_tcp_ses_lock);
2358                 return;
2359         }
2360
2361         /* tc_count can never go negative */
2362         WARN_ON(tcon->tc_count < 0);
2363
2364         list_del_init(&tcon->tcon_list);
2365         spin_unlock(&tcon->tc_lock);
2366         spin_unlock(&cifs_tcp_ses_lock);
2367
2368         /* cancel polling of interfaces */
2369         cancel_delayed_work_sync(&tcon->query_interfaces);
2370
2371         if (tcon->use_witness) {
2372                 int rc;
2373
2374                 rc = cifs_swn_unregister(tcon);
2375                 if (rc < 0) {
2376                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2377                                         __func__, rc);
2378                 }
2379         }
2380
2381         xid = get_xid();
2382         if (ses->server->ops->tree_disconnect)
2383                 ses->server->ops->tree_disconnect(xid, tcon);
2384         _free_xid(xid);
2385
2386         cifs_fscache_release_super_cookie(tcon);
2387         tconInfoFree(tcon);
2388         cifs_put_smb_ses(ses);
2389 }
2390
2391 /**
2392  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2393  * @ses: smb session to issue the request on
2394  * @ctx: the superblock configuration context to use for building the
2395  *
2396  * - tcon refcount is the number of mount points using the tcon.
2397  * - ses refcount is the number of tcon using the session.
2398  *
2399  * 1. This function assumes it is being called from cifs_mount() where
2400  *    we already got a session reference (ses refcount +1).
2401  *
2402  * 2. Since we're in the context of adding a mount point, the end
2403  *    result should be either:
2404  *
2405  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2406  *    its session refcount incremented (1 new tcon). This +1 was
2407  *    already done in (1).
2408  *
2409  * b) an existing tcon with refcount+1 (add a mount point to it) and
2410  *    identical ses refcount (no new tcon). Because of (1) we need to
2411  *    decrement the ses refcount.
2412  */
2413 static struct cifs_tcon *
2414 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2415 {
2416         int rc, xid;
2417         struct cifs_tcon *tcon;
2418
2419         tcon = cifs_find_tcon(ses, ctx);
2420         if (tcon) {
2421                 /*
2422                  * tcon has refcount already incremented but we need to
2423                  * decrement extra ses reference gotten by caller (case b)
2424                  */
2425                 cifs_dbg(FYI, "Found match on UNC path\n");
2426                 cifs_put_smb_ses(ses);
2427                 return tcon;
2428         }
2429
2430         if (!ses->server->ops->tree_connect) {
2431                 rc = -ENOSYS;
2432                 goto out_fail;
2433         }
2434
2435         tcon = tconInfoAlloc();
2436         if (tcon == NULL) {
2437                 rc = -ENOMEM;
2438                 goto out_fail;
2439         }
2440
2441         if (ctx->snapshot_time) {
2442                 if (ses->server->vals->protocol_id == 0) {
2443                         cifs_dbg(VFS,
2444                              "Use SMB2 or later for snapshot mount option\n");
2445                         rc = -EOPNOTSUPP;
2446                         goto out_fail;
2447                 } else
2448                         tcon->snapshot_time = ctx->snapshot_time;
2449         }
2450
2451         if (ctx->handle_timeout) {
2452                 if (ses->server->vals->protocol_id == 0) {
2453                         cifs_dbg(VFS,
2454                              "Use SMB2.1 or later for handle timeout option\n");
2455                         rc = -EOPNOTSUPP;
2456                         goto out_fail;
2457                 } else
2458                         tcon->handle_timeout = ctx->handle_timeout;
2459         }
2460
2461         tcon->ses = ses;
2462         if (ctx->password) {
2463                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2464                 if (!tcon->password) {
2465                         rc = -ENOMEM;
2466                         goto out_fail;
2467                 }
2468         }
2469
2470         if (ctx->seal) {
2471                 if (ses->server->vals->protocol_id == 0) {
2472                         cifs_dbg(VFS,
2473                                  "SMB3 or later required for encryption\n");
2474                         rc = -EOPNOTSUPP;
2475                         goto out_fail;
2476                 } else if (tcon->ses->server->capabilities &
2477                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2478                         tcon->seal = true;
2479                 else {
2480                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2481                         rc = -EOPNOTSUPP;
2482                         goto out_fail;
2483                 }
2484         }
2485
2486         if (ctx->linux_ext) {
2487                 if (ses->server->posix_ext_supported) {
2488                         tcon->posix_extensions = true;
2489                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2490                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2491                     (strcmp(ses->server->vals->version_string,
2492                      SMB3ANY_VERSION_STRING) == 0) ||
2493                     (strcmp(ses->server->vals->version_string,
2494                      SMBDEFAULT_VERSION_STRING) == 0)) {
2495                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2496                         rc = -EOPNOTSUPP;
2497                         goto out_fail;
2498                 } else {
2499                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2500                                 "disabled but required for POSIX extensions\n");
2501                         rc = -EOPNOTSUPP;
2502                         goto out_fail;
2503                 }
2504         }
2505
2506         xid = get_xid();
2507         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2508                                             ctx->local_nls);
2509         free_xid(xid);
2510         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2511         if (rc)
2512                 goto out_fail;
2513
2514         tcon->use_persistent = false;
2515         /* check if SMB2 or later, CIFS does not support persistent handles */
2516         if (ctx->persistent) {
2517                 if (ses->server->vals->protocol_id == 0) {
2518                         cifs_dbg(VFS,
2519                              "SMB3 or later required for persistent handles\n");
2520                         rc = -EOPNOTSUPP;
2521                         goto out_fail;
2522                 } else if (ses->server->capabilities &
2523                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2524                         tcon->use_persistent = true;
2525                 else /* persistent handles requested but not supported */ {
2526                         cifs_dbg(VFS,
2527                                 "Persistent handles not supported on share\n");
2528                         rc = -EOPNOTSUPP;
2529                         goto out_fail;
2530                 }
2531         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2532              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2533              && (ctx->nopersistent == false)) {
2534                 cifs_dbg(FYI, "enabling persistent handles\n");
2535                 tcon->use_persistent = true;
2536         } else if (ctx->resilient) {
2537                 if (ses->server->vals->protocol_id == 0) {
2538                         cifs_dbg(VFS,
2539                              "SMB2.1 or later required for resilient handles\n");
2540                         rc = -EOPNOTSUPP;
2541                         goto out_fail;
2542                 }
2543                 tcon->use_resilient = true;
2544         }
2545
2546         tcon->use_witness = false;
2547         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2548                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2549                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2550                                 /*
2551                                  * Set witness in use flag in first place
2552                                  * to retry registration in the echo task
2553                                  */
2554                                 tcon->use_witness = true;
2555                                 /* And try to register immediately */
2556                                 rc = cifs_swn_register(tcon);
2557                                 if (rc < 0) {
2558                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2559                                         goto out_fail;
2560                                 }
2561                         } else {
2562                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2563                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2564                                 rc = -EOPNOTSUPP;
2565                                 goto out_fail;
2566                         }
2567                 } else {
2568                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2569                         rc = -EOPNOTSUPP;
2570                         goto out_fail;
2571                 }
2572         }
2573
2574         /* If the user really knows what they are doing they can override */
2575         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2576                 if (ctx->cache_ro)
2577                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2578                 else if (ctx->cache_rw)
2579                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2580         }
2581
2582         if (ctx->no_lease) {
2583                 if (ses->server->vals->protocol_id == 0) {
2584                         cifs_dbg(VFS,
2585                                 "SMB2 or later required for nolease option\n");
2586                         rc = -EOPNOTSUPP;
2587                         goto out_fail;
2588                 } else
2589                         tcon->no_lease = ctx->no_lease;
2590         }
2591
2592         /*
2593          * We can have only one retry value for a connection to a share so for
2594          * resources mounted more than once to the same server share the last
2595          * value passed in for the retry flag is used.
2596          */
2597         tcon->retry = ctx->retry;
2598         tcon->nocase = ctx->nocase;
2599         tcon->broken_sparse_sup = ctx->no_sparse;
2600         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2601                 tcon->nohandlecache = ctx->nohandlecache;
2602         else
2603                 tcon->nohandlecache = true;
2604         tcon->nodelete = ctx->nodelete;
2605         tcon->local_lease = ctx->local_lease;
2606         INIT_LIST_HEAD(&tcon->pending_opens);
2607         tcon->status = TID_GOOD;
2608
2609         /* schedule query interfaces poll */
2610         INIT_DELAYED_WORK(&tcon->query_interfaces,
2611                           smb2_query_server_interfaces);
2612         queue_delayed_work(cifsiod_wq, &tcon->query_interfaces,
2613                            (SMB_INTERFACE_POLL_INTERVAL * HZ));
2614
2615         spin_lock(&cifs_tcp_ses_lock);
2616         list_add(&tcon->tcon_list, &ses->tcon_list);
2617         spin_unlock(&cifs_tcp_ses_lock);
2618
2619         return tcon;
2620
2621 out_fail:
2622         tconInfoFree(tcon);
2623         return ERR_PTR(rc);
2624 }
2625
2626 void
2627 cifs_put_tlink(struct tcon_link *tlink)
2628 {
2629         if (!tlink || IS_ERR(tlink))
2630                 return;
2631
2632         if (!atomic_dec_and_test(&tlink->tl_count) ||
2633             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2634                 tlink->tl_time = jiffies;
2635                 return;
2636         }
2637
2638         if (!IS_ERR(tlink_tcon(tlink)))
2639                 cifs_put_tcon(tlink_tcon(tlink));
2640         kfree(tlink);
2641         return;
2642 }
2643
2644 static int
2645 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2646 {
2647         struct cifs_sb_info *old = CIFS_SB(sb);
2648         struct cifs_sb_info *new = mnt_data->cifs_sb;
2649         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2650         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2651
2652         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2653                 return 0;
2654
2655         if (old->mnt_cifs_serverino_autodisabled)
2656                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2657
2658         if (oldflags != newflags)
2659                 return 0;
2660
2661         /*
2662          * We want to share sb only if we don't specify an r/wsize or
2663          * specified r/wsize is greater than or equal to existing one.
2664          */
2665         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2666                 return 0;
2667
2668         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2669                 return 0;
2670
2671         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2672             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2673                 return 0;
2674
2675         if (old->ctx->file_mode != new->ctx->file_mode ||
2676             old->ctx->dir_mode != new->ctx->dir_mode)
2677                 return 0;
2678
2679         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2680                 return 0;
2681
2682         if (old->ctx->acregmax != new->ctx->acregmax)
2683                 return 0;
2684         if (old->ctx->acdirmax != new->ctx->acdirmax)
2685                 return 0;
2686         if (old->ctx->closetimeo != new->ctx->closetimeo)
2687                 return 0;
2688
2689         return 1;
2690 }
2691
2692 static int
2693 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2694 {
2695         struct cifs_sb_info *old = CIFS_SB(sb);
2696         struct cifs_sb_info *new = mnt_data->cifs_sb;
2697         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2698                 old->prepath;
2699         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2700                 new->prepath;
2701
2702         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2703                 return 1;
2704         else if (!old_set && !new_set)
2705                 return 1;
2706
2707         return 0;
2708 }
2709
2710 int
2711 cifs_match_super(struct super_block *sb, void *data)
2712 {
2713         struct cifs_mnt_data *mnt_data = data;
2714         struct smb3_fs_context *ctx;
2715         struct cifs_sb_info *cifs_sb;
2716         struct TCP_Server_Info *tcp_srv;
2717         struct cifs_ses *ses;
2718         struct cifs_tcon *tcon;
2719         struct tcon_link *tlink;
2720         bool dfs_super_cmp;
2721         int rc = 0;
2722
2723         spin_lock(&cifs_tcp_ses_lock);
2724         cifs_sb = CIFS_SB(sb);
2725         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2726         if (tlink == NULL) {
2727                 /* can not match superblock if tlink were ever null */
2728                 spin_unlock(&cifs_tcp_ses_lock);
2729                 return 0;
2730         }
2731         tcon = tlink_tcon(tlink);
2732         ses = tcon->ses;
2733         tcp_srv = ses->server;
2734
2735         dfs_super_cmp = IS_ENABLED(CONFIG_CIFS_DFS_UPCALL) && tcp_srv->origin_fullpath;
2736
2737         ctx = mnt_data->ctx;
2738
2739         spin_lock(&tcp_srv->srv_lock);
2740         spin_lock(&ses->ses_lock);
2741         spin_lock(&tcon->tc_lock);
2742         if (!match_server(tcp_srv, ctx, dfs_super_cmp) ||
2743             !match_session(ses, ctx) ||
2744             !match_tcon(tcon, ctx, dfs_super_cmp) ||
2745             !match_prepath(sb, mnt_data)) {
2746                 rc = 0;
2747                 goto out;
2748         }
2749
2750         rc = compare_mount_options(sb, mnt_data);
2751 out:
2752         spin_unlock(&tcon->tc_lock);
2753         spin_unlock(&ses->ses_lock);
2754         spin_unlock(&tcp_srv->srv_lock);
2755
2756         spin_unlock(&cifs_tcp_ses_lock);
2757         cifs_put_tlink(tlink);
2758         return rc;
2759 }
2760
2761 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2762 static struct lock_class_key cifs_key[2];
2763 static struct lock_class_key cifs_slock_key[2];
2764
2765 static inline void
2766 cifs_reclassify_socket4(struct socket *sock)
2767 {
2768         struct sock *sk = sock->sk;
2769         BUG_ON(!sock_allow_reclassification(sk));
2770         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2771                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2772 }
2773
2774 static inline void
2775 cifs_reclassify_socket6(struct socket *sock)
2776 {
2777         struct sock *sk = sock->sk;
2778         BUG_ON(!sock_allow_reclassification(sk));
2779         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2780                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2781 }
2782 #else
2783 static inline void
2784 cifs_reclassify_socket4(struct socket *sock)
2785 {
2786 }
2787
2788 static inline void
2789 cifs_reclassify_socket6(struct socket *sock)
2790 {
2791 }
2792 #endif
2793
2794 /* See RFC1001 section 14 on representation of Netbios names */
2795 static void rfc1002mangle(char *target, char *source, unsigned int length)
2796 {
2797         unsigned int i, j;
2798
2799         for (i = 0, j = 0; i < (length); i++) {
2800                 /* mask a nibble at a time and encode */
2801                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2802                 target[j+1] = 'A' + (0x0F & source[i]);
2803                 j += 2;
2804         }
2805
2806 }
2807
2808 static int
2809 bind_socket(struct TCP_Server_Info *server)
2810 {
2811         int rc = 0;
2812         if (server->srcaddr.ss_family != AF_UNSPEC) {
2813                 /* Bind to the specified local IP address */
2814                 struct socket *socket = server->ssocket;
2815                 rc = socket->ops->bind(socket,
2816                                        (struct sockaddr *) &server->srcaddr,
2817                                        sizeof(server->srcaddr));
2818                 if (rc < 0) {
2819                         struct sockaddr_in *saddr4;
2820                         struct sockaddr_in6 *saddr6;
2821                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2822                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2823                         if (saddr6->sin6_family == AF_INET6)
2824                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2825                                          &saddr6->sin6_addr, rc);
2826                         else
2827                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2828                                          &saddr4->sin_addr.s_addr, rc);
2829                 }
2830         }
2831         return rc;
2832 }
2833
2834 static int
2835 ip_rfc1001_connect(struct TCP_Server_Info *server)
2836 {
2837         int rc = 0;
2838         /*
2839          * some servers require RFC1001 sessinit before sending
2840          * negprot - BB check reconnection in case where second
2841          * sessinit is sent but no second negprot
2842          */
2843         struct rfc1002_session_packet *ses_init_buf;
2844         unsigned int req_noscope_len;
2845         struct smb_hdr *smb_buf;
2846
2847         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2848                                GFP_KERNEL);
2849
2850         if (ses_init_buf) {
2851                 ses_init_buf->trailer.session_req.called_len = 32;
2852
2853                 if (server->server_RFC1001_name[0] != 0)
2854                         rfc1002mangle(ses_init_buf->trailer.
2855                                       session_req.called_name,
2856                                       server->server_RFC1001_name,
2857                                       RFC1001_NAME_LEN_WITH_NULL);
2858                 else
2859                         rfc1002mangle(ses_init_buf->trailer.
2860                                       session_req.called_name,
2861                                       DEFAULT_CIFS_CALLED_NAME,
2862                                       RFC1001_NAME_LEN_WITH_NULL);
2863
2864                 ses_init_buf->trailer.session_req.calling_len = 32;
2865
2866                 /*
2867                  * calling name ends in null (byte 16) from old smb
2868                  * convention.
2869                  */
2870                 if (server->workstation_RFC1001_name[0] != 0)
2871                         rfc1002mangle(ses_init_buf->trailer.
2872                                       session_req.calling_name,
2873                                       server->workstation_RFC1001_name,
2874                                       RFC1001_NAME_LEN_WITH_NULL);
2875                 else
2876                         rfc1002mangle(ses_init_buf->trailer.
2877                                       session_req.calling_name,
2878                                       "LINUX_CIFS_CLNT",
2879                                       RFC1001_NAME_LEN_WITH_NULL);
2880
2881                 ses_init_buf->trailer.session_req.scope1 = 0;
2882                 ses_init_buf->trailer.session_req.scope2 = 0;
2883                 smb_buf = (struct smb_hdr *)ses_init_buf;
2884
2885                 /* sizeof RFC1002_SESSION_REQUEST with no scopes */
2886                 req_noscope_len = sizeof(struct rfc1002_session_packet) - 2;
2887
2888                 /* == cpu_to_be32(0x81000044) */
2889                 smb_buf->smb_buf_length =
2890                         cpu_to_be32((RFC1002_SESSION_REQUEST << 24) | req_noscope_len);
2891                 rc = smb_send(server, smb_buf, 0x44);
2892                 kfree(ses_init_buf);
2893                 /*
2894                  * RFC1001 layer in at least one server
2895                  * requires very short break before negprot
2896                  * presumably because not expecting negprot
2897                  * to follow so fast.  This is a simple
2898                  * solution that works without
2899                  * complicating the code and causes no
2900                  * significant slowing down on mount
2901                  * for everyone else
2902                  */
2903                 usleep_range(1000, 2000);
2904         }
2905         /*
2906          * else the negprot may still work without this
2907          * even though malloc failed
2908          */
2909
2910         return rc;
2911 }
2912
2913 static int
2914 generic_ip_connect(struct TCP_Server_Info *server)
2915 {
2916         int rc = 0;
2917         __be16 sport;
2918         int slen, sfamily;
2919         struct socket *socket = server->ssocket;
2920         struct sockaddr *saddr;
2921
2922         saddr = (struct sockaddr *) &server->dstaddr;
2923
2924         if (server->dstaddr.ss_family == AF_INET6) {
2925                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2926
2927                 sport = ipv6->sin6_port;
2928                 slen = sizeof(struct sockaddr_in6);
2929                 sfamily = AF_INET6;
2930                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2931                                 ntohs(sport));
2932         } else {
2933                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2934
2935                 sport = ipv4->sin_port;
2936                 slen = sizeof(struct sockaddr_in);
2937                 sfamily = AF_INET;
2938                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2939                                 ntohs(sport));
2940         }
2941
2942         if (socket == NULL) {
2943                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2944                                    IPPROTO_TCP, &socket, 1);
2945                 if (rc < 0) {
2946                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2947                         server->ssocket = NULL;
2948                         return rc;
2949                 }
2950
2951                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2952                 cifs_dbg(FYI, "Socket created\n");
2953                 server->ssocket = socket;
2954                 socket->sk->sk_allocation = GFP_NOFS;
2955                 socket->sk->sk_use_task_frag = false;
2956                 if (sfamily == AF_INET6)
2957                         cifs_reclassify_socket6(socket);
2958                 else
2959                         cifs_reclassify_socket4(socket);
2960         }
2961
2962         rc = bind_socket(server);
2963         if (rc < 0)
2964                 return rc;
2965
2966         /*
2967          * Eventually check for other socket options to change from
2968          * the default. sock_setsockopt not used because it expects
2969          * user space buffer
2970          */
2971         socket->sk->sk_rcvtimeo = 7 * HZ;
2972         socket->sk->sk_sndtimeo = 5 * HZ;
2973
2974         /* make the bufsizes depend on wsize/rsize and max requests */
2975         if (server->noautotune) {
2976                 if (socket->sk->sk_sndbuf < (200 * 1024))
2977                         socket->sk->sk_sndbuf = 200 * 1024;
2978                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2979                         socket->sk->sk_rcvbuf = 140 * 1024;
2980         }
2981
2982         if (server->tcp_nodelay)
2983                 tcp_sock_set_nodelay(socket->sk);
2984
2985         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2986                  socket->sk->sk_sndbuf,
2987                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2988
2989         rc = socket->ops->connect(socket, saddr, slen,
2990                                   server->noblockcnt ? O_NONBLOCK : 0);
2991         /*
2992          * When mounting SMB root file systems, we do not want to block in
2993          * connect. Otherwise bail out and then let cifs_reconnect() perform
2994          * reconnect failover - if possible.
2995          */
2996         if (server->noblockcnt && rc == -EINPROGRESS)
2997                 rc = 0;
2998         if (rc < 0) {
2999                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
3000                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
3001                 sock_release(socket);
3002                 server->ssocket = NULL;
3003                 return rc;
3004         }
3005         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
3006         if (sport == htons(RFC1001_PORT))
3007                 rc = ip_rfc1001_connect(server);
3008
3009         return rc;
3010 }
3011
3012 static int
3013 ip_connect(struct TCP_Server_Info *server)
3014 {
3015         __be16 *sport;
3016         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3017         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3018
3019         if (server->dstaddr.ss_family == AF_INET6)
3020                 sport = &addr6->sin6_port;
3021         else
3022                 sport = &addr->sin_port;
3023
3024         if (*sport == 0) {
3025                 int rc;
3026
3027                 /* try with 445 port at first */
3028                 *sport = htons(CIFS_PORT);
3029
3030                 rc = generic_ip_connect(server);
3031                 if (rc >= 0)
3032                         return rc;
3033
3034                 /* if it failed, try with 139 port */
3035                 *sport = htons(RFC1001_PORT);
3036         }
3037
3038         return generic_ip_connect(server);
3039 }
3040
3041 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3042 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
3043                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3044 {
3045         /*
3046          * If we are reconnecting then should we check to see if
3047          * any requested capabilities changed locally e.g. via
3048          * remount but we can not do much about it here
3049          * if they have (even if we could detect it by the following)
3050          * Perhaps we could add a backpointer to array of sb from tcon
3051          * or if we change to make all sb to same share the same
3052          * sb as NFS - then we only have one backpointer to sb.
3053          * What if we wanted to mount the server share twice once with
3054          * and once without posixacls or posix paths?
3055          */
3056         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3057
3058         if (ctx && ctx->no_linux_ext) {
3059                 tcon->fsUnixInfo.Capability = 0;
3060                 tcon->unix_ext = 0; /* Unix Extensions disabled */
3061                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
3062                 return;
3063         } else if (ctx)
3064                 tcon->unix_ext = 1; /* Unix Extensions supported */
3065
3066         if (!tcon->unix_ext) {
3067                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
3068                 return;
3069         }
3070
3071         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
3072                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
3073                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
3074                 /*
3075                  * check for reconnect case in which we do not
3076                  * want to change the mount behavior if we can avoid it
3077                  */
3078                 if (ctx == NULL) {
3079                         /*
3080                          * turn off POSIX ACL and PATHNAMES if not set
3081                          * originally at mount time
3082                          */
3083                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
3084                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3085                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3086                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3087                                         cifs_dbg(VFS, "POSIXPATH support change\n");
3088                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3089                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
3090                                 cifs_dbg(VFS, "possible reconnect error\n");
3091                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
3092                         }
3093                 }
3094
3095                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3096                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
3097
3098                 cap &= CIFS_UNIX_CAP_MASK;
3099                 if (ctx && ctx->no_psx_acl)
3100                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
3101                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
3102                         cifs_dbg(FYI, "negotiated posix acl support\n");
3103                         if (cifs_sb)
3104                                 cifs_sb->mnt_cifs_flags |=
3105                                         CIFS_MOUNT_POSIXACL;
3106                 }
3107
3108                 if (ctx && ctx->posix_paths == 0)
3109                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
3110                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
3111                         cifs_dbg(FYI, "negotiate posix pathnames\n");
3112                         if (cifs_sb)
3113                                 cifs_sb->mnt_cifs_flags |=
3114                                         CIFS_MOUNT_POSIX_PATHS;
3115                 }
3116
3117                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
3118 #ifdef CONFIG_CIFS_DEBUG2
3119                 if (cap & CIFS_UNIX_FCNTL_CAP)
3120                         cifs_dbg(FYI, "FCNTL cap\n");
3121                 if (cap & CIFS_UNIX_EXTATTR_CAP)
3122                         cifs_dbg(FYI, "EXTATTR cap\n");
3123                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
3124                         cifs_dbg(FYI, "POSIX path cap\n");
3125                 if (cap & CIFS_UNIX_XATTR_CAP)
3126                         cifs_dbg(FYI, "XATTR cap\n");
3127                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
3128                         cifs_dbg(FYI, "POSIX ACL cap\n");
3129                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
3130                         cifs_dbg(FYI, "very large read cap\n");
3131                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
3132                         cifs_dbg(FYI, "very large write cap\n");
3133                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
3134                         cifs_dbg(FYI, "transport encryption cap\n");
3135                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
3136                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
3137 #endif /* CIFS_DEBUG2 */
3138                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
3139                         if (ctx == NULL)
3140                                 cifs_dbg(FYI, "resetting capabilities failed\n");
3141                         else
3142                                 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");
3143
3144                 }
3145         }
3146 }
3147 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3148
3149 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
3150 {
3151         struct smb3_fs_context *ctx = cifs_sb->ctx;
3152
3153         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
3154
3155         spin_lock_init(&cifs_sb->tlink_tree_lock);
3156         cifs_sb->tlink_tree = RB_ROOT;
3157
3158         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
3159                  ctx->file_mode, ctx->dir_mode);
3160
3161         /* this is needed for ASCII cp to Unicode converts */
3162         if (ctx->iocharset == NULL) {
3163                 /* load_nls_default cannot return null */
3164                 cifs_sb->local_nls = load_nls_default();
3165         } else {
3166                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3167                 if (cifs_sb->local_nls == NULL) {
3168                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3169                                  ctx->iocharset);
3170                         return -ELIBACC;
3171                 }
3172         }
3173         ctx->local_nls = cifs_sb->local_nls;
3174
3175         smb3_update_mnt_flags(cifs_sb);
3176
3177         if (ctx->direct_io)
3178                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3179         if (ctx->cache_ro) {
3180                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3181                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3182         } else if (ctx->cache_rw) {
3183                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3184                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3185                                             CIFS_MOUNT_RW_CACHE);
3186         }
3187
3188         if ((ctx->cifs_acl) && (ctx->dynperm))
3189                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3190
3191         if (ctx->prepath) {
3192                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3193                 if (cifs_sb->prepath == NULL)
3194                         return -ENOMEM;
3195                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3196         }
3197
3198         return 0;
3199 }
3200
3201 /* Release all succeed connections */
3202 void cifs_mount_put_conns(struct cifs_mount_ctx *mnt_ctx)
3203 {
3204         int rc = 0;
3205
3206         if (mnt_ctx->tcon)
3207                 cifs_put_tcon(mnt_ctx->tcon);
3208         else if (mnt_ctx->ses)
3209                 cifs_put_smb_ses(mnt_ctx->ses);
3210         else if (mnt_ctx->server)
3211                 cifs_put_tcp_session(mnt_ctx->server, 0);
3212         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3213         free_xid(mnt_ctx->xid);
3214 }
3215
3216 int cifs_mount_get_session(struct cifs_mount_ctx *mnt_ctx)
3217 {
3218         struct TCP_Server_Info *server = NULL;
3219         struct smb3_fs_context *ctx;
3220         struct cifs_ses *ses = NULL;
3221         unsigned int xid;
3222         int rc = 0;
3223
3224         xid = get_xid();
3225
3226         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->fs_ctx)) {
3227                 rc = -EINVAL;
3228                 goto out;
3229         }
3230         ctx = mnt_ctx->fs_ctx;
3231
3232         /* get a reference to a tcp session */
3233         server = cifs_get_tcp_session(ctx, NULL);
3234         if (IS_ERR(server)) {
3235                 rc = PTR_ERR(server);
3236                 server = NULL;
3237                 goto out;
3238         }
3239
3240         /* get a reference to a SMB session */
3241         ses = cifs_get_smb_ses(server, ctx);
3242         if (IS_ERR(ses)) {
3243                 rc = PTR_ERR(ses);
3244                 ses = NULL;
3245                 goto out;
3246         }
3247
3248         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3249                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3250                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3251                 rc = -EOPNOTSUPP;
3252         }
3253
3254 out:
3255         mnt_ctx->xid = xid;
3256         mnt_ctx->server = server;
3257         mnt_ctx->ses = ses;
3258         mnt_ctx->tcon = NULL;
3259
3260         return rc;
3261 }
3262
3263 int cifs_mount_get_tcon(struct cifs_mount_ctx *mnt_ctx)
3264 {
3265         struct TCP_Server_Info *server;
3266         struct cifs_sb_info *cifs_sb;
3267         struct smb3_fs_context *ctx;
3268         struct cifs_tcon *tcon = NULL;
3269         int rc = 0;
3270
3271         if (WARN_ON_ONCE(!mnt_ctx || !mnt_ctx->server || !mnt_ctx->ses || !mnt_ctx->fs_ctx ||
3272                          !mnt_ctx->cifs_sb)) {
3273                 rc = -EINVAL;
3274                 goto out;
3275         }
3276         server = mnt_ctx->server;
3277         ctx = mnt_ctx->fs_ctx;
3278         cifs_sb = mnt_ctx->cifs_sb;
3279
3280         /* search for existing tcon to this server share */
3281         tcon = cifs_get_tcon(mnt_ctx->ses, ctx);
3282         if (IS_ERR(tcon)) {
3283                 rc = PTR_ERR(tcon);
3284                 tcon = NULL;
3285                 goto out;
3286         }
3287
3288         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3289         if (tcon->posix_extensions)
3290                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3291
3292 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3293         /* tell server which Unix caps we support */
3294         if (cap_unix(tcon->ses)) {
3295                 /*
3296                  * reset of caps checks mount to see if unix extensions disabled
3297                  * for just this mount.
3298                  */
3299                 reset_cifs_unix_caps(mnt_ctx->xid, tcon, cifs_sb, ctx);
3300                 spin_lock(&tcon->ses->server->srv_lock);
3301                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3302                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3303                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3304                         spin_unlock(&tcon->ses->server->srv_lock);
3305                         rc = -EACCES;
3306                         goto out;
3307                 }
3308                 spin_unlock(&tcon->ses->server->srv_lock);
3309         } else
3310 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3311                 tcon->unix_ext = 0; /* server does not support them */
3312
3313         /* do not care if a following call succeed - informational */
3314         if (!tcon->pipe && server->ops->qfs_tcon) {
3315                 server->ops->qfs_tcon(mnt_ctx->xid, tcon, cifs_sb);
3316                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3317                         if (tcon->fsDevInfo.DeviceCharacteristics &
3318                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3319                                 cifs_dbg(VFS, "mounted to read only share\n");
3320                         else if ((cifs_sb->mnt_cifs_flags &
3321                                   CIFS_MOUNT_RW_CACHE) == 0)
3322                                 cifs_dbg(VFS, "read only mount of RW share\n");
3323                         /* no need to log a RW mount of a typical RW share */
3324                 }
3325         }
3326
3327         /*
3328          * Clamp the rsize/wsize mount arguments if they are too big for the server
3329          * and set the rsize/wsize to the negotiated values if not passed in by
3330          * the user on mount
3331          */
3332         if ((cifs_sb->ctx->wsize == 0) ||
3333             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3334                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3335         if ((cifs_sb->ctx->rsize == 0) ||
3336             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3337                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3338
3339         /*
3340          * The cookie is initialized from volume info returned above.
3341          * Inside cifs_fscache_get_super_cookie it checks
3342          * that we do not get super cookie twice.
3343          */
3344         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3345                 cifs_fscache_get_super_cookie(tcon);
3346
3347 out:
3348         mnt_ctx->tcon = tcon;
3349         return rc;
3350 }
3351
3352 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3353                              struct cifs_tcon *tcon)
3354 {
3355         struct tcon_link *tlink;
3356
3357         /* hang the tcon off of the superblock */
3358         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3359         if (tlink == NULL)
3360                 return -ENOMEM;
3361
3362         tlink->tl_uid = ses->linux_uid;
3363         tlink->tl_tcon = tcon;
3364         tlink->tl_time = jiffies;
3365         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3366         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3367
3368         cifs_sb->master_tlink = tlink;
3369         spin_lock(&cifs_sb->tlink_tree_lock);
3370         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3371         spin_unlock(&cifs_sb->tlink_tree_lock);
3372
3373         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3374                                 TLINK_IDLE_EXPIRE);
3375         return 0;
3376 }
3377
3378 static int
3379 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3380                                         unsigned int xid,
3381                                         struct cifs_tcon *tcon,
3382                                         struct cifs_sb_info *cifs_sb,
3383                                         char *full_path,
3384                                         int added_treename)
3385 {
3386         int rc;
3387         char *s;
3388         char sep, tmp;
3389         int skip = added_treename ? 1 : 0;
3390
3391         sep = CIFS_DIR_SEP(cifs_sb);
3392         s = full_path;
3393
3394         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3395         while (rc == 0) {
3396                 /* skip separators */
3397                 while (*s == sep)
3398                         s++;
3399                 if (!*s)
3400                         break;
3401                 /* next separator */
3402                 while (*s && *s != sep)
3403                         s++;
3404                 /*
3405                  * if the treename is added, we then have to skip the first
3406                  * part within the separators
3407                  */
3408                 if (skip) {
3409                         skip = 0;
3410                         continue;
3411                 }
3412                 /*
3413                  * temporarily null-terminate the path at the end of
3414                  * the current component
3415                  */
3416                 tmp = *s;
3417                 *s = 0;
3418                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3419                                                      full_path);
3420                 *s = tmp;
3421         }
3422         return rc;
3423 }
3424
3425 /*
3426  * Check if path is remote (i.e. a DFS share).
3427  *
3428  * Return -EREMOTE if it is, otherwise 0 or -errno.
3429  */
3430 int cifs_is_path_remote(struct cifs_mount_ctx *mnt_ctx)
3431 {
3432         int rc;
3433         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3434         struct TCP_Server_Info *server = mnt_ctx->server;
3435         unsigned int xid = mnt_ctx->xid;
3436         struct cifs_tcon *tcon = mnt_ctx->tcon;
3437         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3438         char *full_path;
3439
3440         if (!server->ops->is_path_accessible)
3441                 return -EOPNOTSUPP;
3442
3443         /*
3444          * cifs_build_path_to_root works only when we have a valid tcon
3445          */
3446         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3447                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3448         if (full_path == NULL)
3449                 return -ENOMEM;
3450
3451         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3452
3453         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3454                                              full_path);
3455         if (rc != 0 && rc != -EREMOTE)
3456                 goto out;
3457
3458         if (rc != -EREMOTE) {
3459                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3460                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3461                 if (rc != 0) {
3462                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3463                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3464                         rc = 0;
3465                 }
3466         }
3467
3468 out:
3469         kfree(full_path);
3470         return rc;
3471 }
3472
3473 #ifdef CONFIG_CIFS_DFS_UPCALL
3474 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3475 {
3476         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3477         bool isdfs;
3478         int rc;
3479
3480         uuid_gen(&mnt_ctx.mount_id);
3481         rc = dfs_mount_share(&mnt_ctx, &isdfs);
3482         if (rc)
3483                 goto error;
3484         if (!isdfs)
3485                 goto out;
3486
3487         /*
3488          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3489          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3490          */
3491         cifs_autodisable_serverino(cifs_sb);
3492         /*
3493          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3494          * that have different prefix paths.
3495          */
3496         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3497         kfree(cifs_sb->prepath);
3498         cifs_sb->prepath = ctx->prepath;
3499         ctx->prepath = NULL;
3500         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3501
3502 out:
3503         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3504         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3505         if (rc)
3506                 goto error;
3507
3508         free_xid(mnt_ctx.xid);
3509         return rc;
3510
3511 error:
3512         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3513         kfree(mnt_ctx.origin_fullpath);
3514         kfree(mnt_ctx.leaf_fullpath);
3515         cifs_mount_put_conns(&mnt_ctx);
3516         return rc;
3517 }
3518 #else
3519 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3520 {
3521         int rc = 0;
3522         struct cifs_mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3523
3524         rc = cifs_mount_get_session(&mnt_ctx);
3525         if (rc)
3526                 goto error;
3527
3528         rc = cifs_mount_get_tcon(&mnt_ctx);
3529         if (rc)
3530                 goto error;
3531
3532         rc = cifs_is_path_remote(&mnt_ctx);
3533         if (rc == -EREMOTE)
3534                 rc = -EOPNOTSUPP;
3535         if (rc)
3536                 goto error;
3537
3538         rc = mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3539         if (rc)
3540                 goto error;
3541
3542         free_xid(mnt_ctx.xid);
3543         return rc;
3544
3545 error:
3546         cifs_mount_put_conns(&mnt_ctx);
3547         return rc;
3548 }
3549 #endif
3550
3551 /*
3552  * Issue a TREE_CONNECT request.
3553  */
3554 int
3555 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3556          const char *tree, struct cifs_tcon *tcon,
3557          const struct nls_table *nls_codepage)
3558 {
3559         struct smb_hdr *smb_buffer;
3560         struct smb_hdr *smb_buffer_response;
3561         TCONX_REQ *pSMB;
3562         TCONX_RSP *pSMBr;
3563         unsigned char *bcc_ptr;
3564         int rc = 0;
3565         int length;
3566         __u16 bytes_left, count;
3567
3568         if (ses == NULL)
3569                 return -EIO;
3570
3571         smb_buffer = cifs_buf_get();
3572         if (smb_buffer == NULL)
3573                 return -ENOMEM;
3574
3575         smb_buffer_response = smb_buffer;
3576
3577         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3578                         NULL /*no tid */ , 4 /*wct */ );
3579
3580         smb_buffer->Mid = get_next_mid(ses->server);
3581         smb_buffer->Uid = ses->Suid;
3582         pSMB = (TCONX_REQ *) smb_buffer;
3583         pSMBr = (TCONX_RSP *) smb_buffer_response;
3584
3585         pSMB->AndXCommand = 0xFF;
3586         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3587         bcc_ptr = &pSMB->Password[0];
3588
3589         pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3590         *bcc_ptr = 0; /* password is null byte */
3591         bcc_ptr++;              /* skip password */
3592         /* already aligned so no need to do it below */
3593
3594         if (ses->server->sign)
3595                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3596
3597         if (ses->capabilities & CAP_STATUS32) {
3598                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3599         }
3600         if (ses->capabilities & CAP_DFS) {
3601                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3602         }
3603         if (ses->capabilities & CAP_UNICODE) {
3604                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3605                 length =
3606                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3607                         6 /* max utf8 char length in bytes */ *
3608                         (/* server len*/ + 256 /* share len */), nls_codepage);
3609                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3610                 bcc_ptr += 2;   /* skip trailing null */
3611         } else {                /* ASCII */
3612                 strcpy(bcc_ptr, tree);
3613                 bcc_ptr += strlen(tree) + 1;
3614         }
3615         strcpy(bcc_ptr, "?????");
3616         bcc_ptr += strlen("?????");
3617         bcc_ptr += 1;
3618         count = bcc_ptr - &pSMB->Password[0];
3619         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3620         pSMB->ByteCount = cpu_to_le16(count);
3621
3622         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3623                          0);
3624
3625         /* above now done in SendReceive */
3626         if (rc == 0) {
3627                 bool is_unicode;
3628
3629                 tcon->tid = smb_buffer_response->Tid;
3630                 bcc_ptr = pByteArea(smb_buffer_response);
3631                 bytes_left = get_bcc(smb_buffer_response);
3632                 length = strnlen(bcc_ptr, bytes_left - 2);
3633                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3634                         is_unicode = true;
3635                 else
3636                         is_unicode = false;
3637
3638
3639                 /* skip service field (NB: this field is always ASCII) */
3640                 if (length == 3) {
3641                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3642                             (bcc_ptr[2] == 'C')) {
3643                                 cifs_dbg(FYI, "IPC connection\n");
3644                                 tcon->ipc = true;
3645                                 tcon->pipe = true;
3646                         }
3647                 } else if (length == 2) {
3648                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3649                                 /* the most common case */
3650                                 cifs_dbg(FYI, "disk share connection\n");
3651                         }
3652                 }
3653                 bcc_ptr += length + 1;
3654                 bytes_left -= (length + 1);
3655                 strscpy(tcon->tree_name, tree, sizeof(tcon->tree_name));
3656
3657                 /* mostly informational -- no need to fail on error here */
3658                 kfree(tcon->nativeFileSystem);
3659                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3660                                                       bytes_left, is_unicode,
3661                                                       nls_codepage);
3662
3663                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3664
3665                 if ((smb_buffer_response->WordCount == 3) ||
3666                          (smb_buffer_response->WordCount == 7))
3667                         /* field is in same location */
3668                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3669                 else
3670                         tcon->Flags = 0;
3671                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3672         }
3673
3674         cifs_buf_release(smb_buffer);
3675         return rc;
3676 }
3677
3678 static void delayed_free(struct rcu_head *p)
3679 {
3680         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3681
3682         unload_nls(cifs_sb->local_nls);
3683         smb3_cleanup_fs_context(cifs_sb->ctx);
3684         kfree(cifs_sb);
3685 }
3686
3687 void
3688 cifs_umount(struct cifs_sb_info *cifs_sb)
3689 {
3690         struct rb_root *root = &cifs_sb->tlink_tree;
3691         struct rb_node *node;
3692         struct tcon_link *tlink;
3693
3694         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3695
3696         spin_lock(&cifs_sb->tlink_tree_lock);
3697         while ((node = rb_first(root))) {
3698                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3699                 cifs_get_tlink(tlink);
3700                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3701                 rb_erase(node, root);
3702
3703                 spin_unlock(&cifs_sb->tlink_tree_lock);
3704                 cifs_put_tlink(tlink);
3705                 spin_lock(&cifs_sb->tlink_tree_lock);
3706         }
3707         spin_unlock(&cifs_sb->tlink_tree_lock);
3708
3709         kfree(cifs_sb->prepath);
3710 #ifdef CONFIG_CIFS_DFS_UPCALL
3711         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3712 #endif
3713         call_rcu(&cifs_sb->rcu, delayed_free);
3714 }
3715
3716 int
3717 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3718                         struct TCP_Server_Info *server)
3719 {
3720         int rc = 0;
3721
3722         if (!server->ops->need_neg || !server->ops->negotiate)
3723                 return -ENOSYS;
3724
3725         /* only send once per connect */
3726         spin_lock(&server->srv_lock);
3727         if (!server->ops->need_neg(server) ||
3728             server->tcpStatus != CifsNeedNegotiate) {
3729                 spin_unlock(&server->srv_lock);
3730                 return 0;
3731         }
3732         server->tcpStatus = CifsInNegotiate;
3733         spin_unlock(&server->srv_lock);
3734
3735         rc = server->ops->negotiate(xid, ses, server);
3736         if (rc == 0) {
3737                 spin_lock(&server->srv_lock);
3738                 if (server->tcpStatus == CifsInNegotiate)
3739                         server->tcpStatus = CifsGood;
3740                 else
3741                         rc = -EHOSTDOWN;
3742                 spin_unlock(&server->srv_lock);
3743         } else {
3744                 spin_lock(&server->srv_lock);
3745                 if (server->tcpStatus == CifsInNegotiate)
3746                         server->tcpStatus = CifsNeedNegotiate;
3747                 spin_unlock(&server->srv_lock);
3748         }
3749
3750         return rc;
3751 }
3752
3753 int
3754 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3755                    struct TCP_Server_Info *server,
3756                    struct nls_table *nls_info)
3757 {
3758         int rc = -ENOSYS;
3759         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
3760         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
3761         bool is_binding = false;
3762
3763         spin_lock(&ses->ses_lock);
3764         if (server->dstaddr.ss_family == AF_INET6)
3765                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI6", &addr6->sin6_addr);
3766         else
3767                 scnprintf(ses->ip_addr, sizeof(ses->ip_addr), "%pI4", &addr->sin_addr);
3768
3769         if (ses->ses_status != SES_GOOD &&
3770             ses->ses_status != SES_NEW &&
3771             ses->ses_status != SES_NEED_RECON) {
3772                 spin_unlock(&ses->ses_lock);
3773                 return 0;
3774         }
3775
3776         /* only send once per connect */
3777         spin_lock(&ses->chan_lock);
3778         if (CIFS_ALL_CHANS_GOOD(ses) ||
3779             cifs_chan_in_reconnect(ses, server)) {
3780                 spin_unlock(&ses->chan_lock);
3781                 spin_unlock(&ses->ses_lock);
3782                 return 0;
3783         }
3784         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3785         cifs_chan_set_in_reconnect(ses, server);
3786         spin_unlock(&ses->chan_lock);
3787
3788         if (!is_binding)
3789                 ses->ses_status = SES_IN_SETUP;
3790         spin_unlock(&ses->ses_lock);
3791
3792         if (!is_binding) {
3793                 ses->capabilities = server->capabilities;
3794                 if (!linuxExtEnabled)
3795                         ses->capabilities &= (~server->vals->cap_unix);
3796
3797                 if (ses->auth_key.response) {
3798                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3799                                  ses->auth_key.response);
3800                         kfree_sensitive(ses->auth_key.response);
3801                         ses->auth_key.response = NULL;
3802                         ses->auth_key.len = 0;
3803                 }
3804         }
3805
3806         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3807                  server->sec_mode, server->capabilities, server->timeAdj);
3808
3809         if (server->ops->sess_setup)
3810                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
3811
3812         if (rc) {
3813                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3814                 spin_lock(&ses->ses_lock);
3815                 if (ses->ses_status == SES_IN_SETUP)
3816                         ses->ses_status = SES_NEED_RECON;
3817                 spin_lock(&ses->chan_lock);
3818                 cifs_chan_clear_in_reconnect(ses, server);
3819                 spin_unlock(&ses->chan_lock);
3820                 spin_unlock(&ses->ses_lock);
3821         } else {
3822                 spin_lock(&ses->ses_lock);
3823                 if (ses->ses_status == SES_IN_SETUP)
3824                         ses->ses_status = SES_GOOD;
3825                 spin_lock(&ses->chan_lock);
3826                 cifs_chan_clear_in_reconnect(ses, server);
3827                 cifs_chan_clear_need_reconnect(ses, server);
3828                 spin_unlock(&ses->chan_lock);
3829                 spin_unlock(&ses->ses_lock);
3830         }
3831
3832         return rc;
3833 }
3834
3835 static int
3836 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3837 {
3838         ctx->sectype = ses->sectype;
3839
3840         /* krb5 is special, since we don't need username or pw */
3841         if (ctx->sectype == Kerberos)
3842                 return 0;
3843
3844         return cifs_set_cifscreds(ctx, ses);
3845 }
3846
3847 static struct cifs_tcon *
3848 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3849 {
3850         int rc;
3851         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3852         struct cifs_ses *ses;
3853         struct cifs_tcon *tcon = NULL;
3854         struct smb3_fs_context *ctx;
3855
3856         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3857         if (ctx == NULL)
3858                 return ERR_PTR(-ENOMEM);
3859
3860         ctx->local_nls = cifs_sb->local_nls;
3861         ctx->linux_uid = fsuid;
3862         ctx->cred_uid = fsuid;
3863         ctx->UNC = master_tcon->tree_name;
3864         ctx->retry = master_tcon->retry;
3865         ctx->nocase = master_tcon->nocase;
3866         ctx->nohandlecache = master_tcon->nohandlecache;
3867         ctx->local_lease = master_tcon->local_lease;
3868         ctx->no_lease = master_tcon->no_lease;
3869         ctx->resilient = master_tcon->use_resilient;
3870         ctx->persistent = master_tcon->use_persistent;
3871         ctx->handle_timeout = master_tcon->handle_timeout;
3872         ctx->no_linux_ext = !master_tcon->unix_ext;
3873         ctx->linux_ext = master_tcon->posix_extensions;
3874         ctx->sectype = master_tcon->ses->sectype;
3875         ctx->sign = master_tcon->ses->sign;
3876         ctx->seal = master_tcon->seal;
3877         ctx->witness = master_tcon->use_witness;
3878
3879         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3880         if (rc) {
3881                 tcon = ERR_PTR(rc);
3882                 goto out;
3883         }
3884
3885         /* get a reference for the same TCP session */
3886         spin_lock(&cifs_tcp_ses_lock);
3887         ++master_tcon->ses->server->srv_count;
3888         spin_unlock(&cifs_tcp_ses_lock);
3889
3890         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3891         if (IS_ERR(ses)) {
3892                 tcon = (struct cifs_tcon *)ses;
3893                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3894                 goto out;
3895         }
3896
3897         tcon = cifs_get_tcon(ses, ctx);
3898         if (IS_ERR(tcon)) {
3899                 cifs_put_smb_ses(ses);
3900                 goto out;
3901         }
3902
3903 #ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
3904         if (cap_unix(ses))
3905                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3906 #endif /* CONFIG_CIFS_ALLOW_INSECURE_LEGACY */
3907
3908 out:
3909         kfree(ctx->username);
3910         kfree_sensitive(ctx->password);
3911         kfree(ctx);
3912
3913         return tcon;
3914 }
3915
3916 struct cifs_tcon *
3917 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3918 {
3919         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3920 }
3921
3922 /* find and return a tlink with given uid */
3923 static struct tcon_link *
3924 tlink_rb_search(struct rb_root *root, kuid_t uid)
3925 {
3926         struct rb_node *node = root->rb_node;
3927         struct tcon_link *tlink;
3928
3929         while (node) {
3930                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3931
3932                 if (uid_gt(tlink->tl_uid, uid))
3933                         node = node->rb_left;
3934                 else if (uid_lt(tlink->tl_uid, uid))
3935                         node = node->rb_right;
3936                 else
3937                         return tlink;
3938         }
3939         return NULL;
3940 }
3941
3942 /* insert a tcon_link into the tree */
3943 static void
3944 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3945 {
3946         struct rb_node **new = &(root->rb_node), *parent = NULL;
3947         struct tcon_link *tlink;
3948
3949         while (*new) {
3950                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3951                 parent = *new;
3952
3953                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3954                         new = &((*new)->rb_left);
3955                 else
3956                         new = &((*new)->rb_right);
3957         }
3958
3959         rb_link_node(&new_tlink->tl_rbnode, parent, new);
3960         rb_insert_color(&new_tlink->tl_rbnode, root);
3961 }
3962
3963 /*
3964  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3965  * current task.
3966  *
3967  * If the superblock doesn't refer to a multiuser mount, then just return
3968  * the master tcon for the mount.
3969  *
3970  * First, search the rbtree for an existing tcon for this fsuid. If one
3971  * exists, then check to see if it's pending construction. If it is then wait
3972  * for construction to complete. Once it's no longer pending, check to see if
3973  * it failed and either return an error or retry construction, depending on
3974  * the timeout.
3975  *
3976  * If one doesn't exist then insert a new tcon_link struct into the tree and
3977  * try to construct a new one.
3978  */
3979 struct tcon_link *
3980 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3981 {
3982         int ret;
3983         kuid_t fsuid = current_fsuid();
3984         struct tcon_link *tlink, *newtlink;
3985
3986         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3987                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3988
3989         spin_lock(&cifs_sb->tlink_tree_lock);
3990         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3991         if (tlink)
3992                 cifs_get_tlink(tlink);
3993         spin_unlock(&cifs_sb->tlink_tree_lock);
3994
3995         if (tlink == NULL) {
3996                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3997                 if (newtlink == NULL)
3998                         return ERR_PTR(-ENOMEM);
3999                 newtlink->tl_uid = fsuid;
4000                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4001                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4002                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4003                 cifs_get_tlink(newtlink);
4004
4005                 spin_lock(&cifs_sb->tlink_tree_lock);
4006                 /* was one inserted after previous search? */
4007                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4008                 if (tlink) {
4009                         cifs_get_tlink(tlink);
4010                         spin_unlock(&cifs_sb->tlink_tree_lock);
4011                         kfree(newtlink);
4012                         goto wait_for_construction;
4013                 }
4014                 tlink = newtlink;
4015                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4016                 spin_unlock(&cifs_sb->tlink_tree_lock);
4017         } else {
4018 wait_for_construction:
4019                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4020                                   TASK_INTERRUPTIBLE);
4021                 if (ret) {
4022                         cifs_put_tlink(tlink);
4023                         return ERR_PTR(-ERESTARTSYS);
4024                 }
4025
4026                 /* if it's good, return it */
4027                 if (!IS_ERR(tlink->tl_tcon))
4028                         return tlink;
4029
4030                 /* return error if we tried this already recently */
4031                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4032                         cifs_put_tlink(tlink);
4033                         return ERR_PTR(-EACCES);
4034                 }
4035
4036                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4037                         goto wait_for_construction;
4038         }
4039
4040         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4041         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4042         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4043
4044         if (IS_ERR(tlink->tl_tcon)) {
4045                 cifs_put_tlink(tlink);
4046                 return ERR_PTR(-EACCES);
4047         }
4048
4049         return tlink;
4050 }
4051
4052 /*
4053  * periodic workqueue job that scans tcon_tree for a superblock and closes
4054  * out tcons.
4055  */
4056 static void
4057 cifs_prune_tlinks(struct work_struct *work)
4058 {
4059         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4060                                                     prune_tlinks.work);
4061         struct rb_root *root = &cifs_sb->tlink_tree;
4062         struct rb_node *node;
4063         struct rb_node *tmp;
4064         struct tcon_link *tlink;
4065
4066         /*
4067          * Because we drop the spinlock in the loop in order to put the tlink
4068          * it's not guarded against removal of links from the tree. The only
4069          * places that remove entries from the tree are this function and
4070          * umounts. Because this function is non-reentrant and is canceled
4071          * before umount can proceed, this is safe.
4072          */
4073         spin_lock(&cifs_sb->tlink_tree_lock);
4074         node = rb_first(root);
4075         while (node != NULL) {
4076                 tmp = node;
4077                 node = rb_next(tmp);
4078                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4079
4080                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4081                     atomic_read(&tlink->tl_count) != 0 ||
4082                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4083                         continue;
4084
4085                 cifs_get_tlink(tlink);
4086                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4087                 rb_erase(tmp, root);
4088
4089                 spin_unlock(&cifs_sb->tlink_tree_lock);
4090                 cifs_put_tlink(tlink);
4091                 spin_lock(&cifs_sb->tlink_tree_lock);
4092         }
4093         spin_unlock(&cifs_sb->tlink_tree_lock);
4094
4095         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4096                                 TLINK_IDLE_EXPIRE);
4097 }
4098
4099 #ifndef CONFIG_CIFS_DFS_UPCALL
4100 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4101 {
4102         int rc;
4103         const struct smb_version_operations *ops = tcon->ses->server->ops;
4104
4105         /* only send once per connect */
4106         spin_lock(&tcon->tc_lock);
4107         if (tcon->ses->ses_status != SES_GOOD ||
4108             (tcon->status != TID_NEW &&
4109             tcon->status != TID_NEED_TCON)) {
4110                 spin_unlock(&tcon->tc_lock);
4111                 return 0;
4112         }
4113         tcon->status = TID_IN_TCON;
4114         spin_unlock(&tcon->tc_lock);
4115
4116         rc = ops->tree_connect(xid, tcon->ses, tcon->tree_name, tcon, nlsc);
4117         if (rc) {
4118                 spin_lock(&tcon->tc_lock);
4119                 if (tcon->status == TID_IN_TCON)
4120                         tcon->status = TID_NEED_TCON;
4121                 spin_unlock(&tcon->tc_lock);
4122         } else {
4123                 spin_lock(&tcon->tc_lock);
4124                 if (tcon->status == TID_IN_TCON)
4125                         tcon->status = TID_GOOD;
4126                 tcon->need_reconnect = false;
4127                 spin_unlock(&tcon->tc_lock);
4128         }
4129
4130         return rc;
4131 }
4132 #endif