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 ([email protected])
   6  *
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/net.h>
  10 #include <linux/string.h>
  11 #include <linux/sched/mm.h>
  12 #include <linux/sched/signal.h>
  13 #include <linux/list.h>
  14 #include <linux/wait.h>
  15 #include <linux/slab.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/ctype.h>
  18 #include <linux/utsname.h>
  19 #include <linux/mempool.h>
  20 #include <linux/delay.h>
  21 #include <linux/completion.h>
  22 #include <linux/kthread.h>
  23 #include <linux/pagevec.h>
  24 #include <linux/freezer.h>
  25 #include <linux/namei.h>
  26 #include <linux/uuid.h>
  27 #include <linux/uaccess.h>
  28 #include <asm/processor.h>
  29 #include <linux/inet.h>
  30 #include <linux/module.h>
  31 #include <keys/user-type.h>
  32 #include <net/ipv6.h>
  33 #include <linux/parser.h>
  34 #include <linux/bvec.h>
  35 #include "cifspdu.h"
  36 #include "cifsglob.h"
  37 #include "cifsproto.h"
  38 #include "cifs_unicode.h"
  39 #include "cifs_debug.h"
  40 #include "cifs_fs_sb.h"
  41 #include "ntlmssp.h"
  42 #include "nterr.h"
  43 #include "rfc1002pdu.h"
  44 #include "fscache.h"
  45 #include "smb2proto.h"
  46 #include "smbdirect.h"
  47 #include "dns_resolve.h"
  48 #ifdef CONFIG_CIFS_DFS_UPCALL
  49 #include "dfs_cache.h"
  50 #endif
  51 #include "fs_context.h"
  52 #include "cifs_swn.h"
  53
  54 extern mempool_t *cifs_req_poolp;
  55 extern bool disable_legacy_dialects;
  56
  57 /* FIXME: should these be tunable? */
  58 #define TLINK_ERROR_EXPIRE      (1 * HZ)
  59 #define TLINK_IDLE_EXPIRE       (600 * HZ)
  60
  61 /* Drop the connection to not overload the server */
  62 #define NUM_STATUS_IO_TIMEOUT   5
  63
  64 struct mount_ctx {
  65         struct cifs_sb_info *cifs_sb;
  66         struct smb3_fs_context *fs_ctx;
  67         unsigned int xid;
  68         struct TCP_Server_Info *server;
  69         struct cifs_ses *ses;
  70         struct cifs_tcon *tcon;
  71 #ifdef CONFIG_CIFS_DFS_UPCALL
  72         struct cifs_ses *root_ses;
  73         uuid_t mount_id;
  74         char *origin_fullpath, *leaf_fullpath;
  75 #endif
  76 };
  77
  78 static int ip_connect(struct TCP_Server_Info *server);
  79 static int generic_ip_connect(struct TCP_Server_Info *server);
  80 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  81 static void cifs_prune_tlinks(struct work_struct *work);
  82
  83 /*
  84  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  85  * get their ip addresses changed at some point.
  86  *
  87  * This should be called with server->srv_mutex held.
  88  */
  89 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  90 {
  91         int rc;
  92         int len;
  93         char *unc, *ipaddr = NULL;
  94         time64_t expiry, now;
  95         unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  96
  97         if (!server->hostname)
  98                 return -EINVAL;
  99
 100         len = strlen(server->hostname) + 3;
 101
 102         unc = kmalloc(len, GFP_KERNEL);
 103         if (!unc) {
 104                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
 105                 return -ENOMEM;
 106         }
 107         scnprintf(unc, len, "\\\\%s", server->hostname);
 108
 109         rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
 110         kfree(unc);
 111
 112         if (rc < 0) {
 113                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 114                          __func__, server->hostname, rc);
 115                 goto requeue_resolve;
 116         }
 117
 118         spin_lock(&cifs_tcp_ses_lock);
 119         rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 120                                   strlen(ipaddr));
 121         spin_unlock(&cifs_tcp_ses_lock);
 122         kfree(ipaddr);
 123
 124         /* rc == 1 means success here */
 125         if (rc) {
 126                 now = ktime_get_real_seconds();
 127                 if (expiry && expiry > now)
 128                         /*
 129                          * To make sure we don't use the cached entry, retry 1s
 130                          * after expiry.
 131                          */
 132                         ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 133         }
 134         rc = !rc ? -1 : 0;
 135
 136 requeue_resolve:
 137         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 138                  __func__, ttl);
 139         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 140
 141         return rc;
 142 }
 143
 144
 145 static void cifs_resolve_server(struct work_struct *work)
 146 {
 147         int rc;
 148         struct TCP_Server_Info *server = container_of(work,
 149                                         struct TCP_Server_Info, resolve.work);
 150
 151         mutex_lock(&server->srv_mutex);
 152
 153         /*
 154          * Resolve the hostname again to make sure that IP address is up-to-date.
 155          */
 156         rc = reconn_set_ipaddr_from_hostname(server);
 157         if (rc) {
 158                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 159                                 __func__, rc);
 160         }
 161
 162         mutex_unlock(&server->srv_mutex);
 163 }
 164
 165 /**
 166  * Mark all sessions and tcons for reconnect.
 167  *
 168  * @server needs to be previously set to CifsNeedReconnect.
 169  */
 170 static void cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server)
 171 {
 172         struct cifs_ses *ses;
 173         struct cifs_tcon *tcon;
 174         struct mid_q_entry *mid, *nmid;
 175         struct list_head retry_list;
 176         struct TCP_Server_Info *pserver;
 177
 178         server->maxBuf = 0;
 179         server->max_read = 0;
 180
 181         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 182         trace_smb3_reconnect(server->CurrentMid, server->conn_id, server->hostname);
 183         /*
 184          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 185          * are not used until reconnected.
 186          */
 187         cifs_dbg(FYI, "%s: marking sessions and tcons for reconnect\n", __func__);
 188
 189         /* If server is a channel, select the primary channel */
 190         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 191
 192         spin_lock(&cifs_tcp_ses_lock);
 193         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 194                 ses->need_reconnect = true;
 195                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list)
 196                         tcon->need_reconnect = true;
 197                 if (ses->tcon_ipc)
 198                         ses->tcon_ipc->need_reconnect = true;
 199         }
 200         spin_unlock(&cifs_tcp_ses_lock);
 201
 202         /* do not want to be sending data on a socket we are freeing */
 203         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 204         mutex_lock(&server->srv_mutex);
 205         if (server->ssocket) {
 206                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 207                          server->ssocket->flags);
 208                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 209                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 210                          server->ssocket->flags);
 211                 sock_release(server->ssocket);
 212                 server->ssocket = NULL;
 213         }
 214         server->sequence_number = 0;
 215         server->session_estab = false;
 216         kfree(server->session_key.response);
 217         server->session_key.response = NULL;
 218         server->session_key.len = 0;
 219         server->lstrp = jiffies;
 220
 221         /* mark submitted MIDs for retry and issue callback */
 222         INIT_LIST_HEAD(&retry_list);
 223         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 224         spin_lock(&GlobalMid_Lock);
 225         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 226                 kref_get(&mid->refcount);
 227                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 228                         mid->mid_state = MID_RETRY_NEEDED;
 229                 list_move(&mid->qhead, &retry_list);
 230                 mid->mid_flags |= MID_DELETED;
 231         }
 232         spin_unlock(&GlobalMid_Lock);
 233         mutex_unlock(&server->srv_mutex);
 234
 235         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 236         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 237                 list_del_init(&mid->qhead);
 238                 mid->callback(mid);
 239                 cifs_mid_q_entry_release(mid);
 240         }
 241
 242         if (cifs_rdma_enabled(server)) {
 243                 mutex_lock(&server->srv_mutex);
 244                 smbd_destroy(server);
 245                 mutex_unlock(&server->srv_mutex);
 246         }
 247 }
 248
 249 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 250 {
 251         spin_lock(&GlobalMid_Lock);
 252         server->nr_targets = num_targets;
 253         if (server->tcpStatus == CifsExiting) {
 254                 /* the demux thread will exit normally next time through the loop */
 255                 spin_unlock(&GlobalMid_Lock);
 256                 wake_up(&server->response_q);
 257                 return false;
 258         }
 259         server->tcpStatus = CifsNeedReconnect;
 260         spin_unlock(&GlobalMid_Lock);
 261         return true;
 262 }
 263
 264 /*
 265  * cifs tcp session reconnection
 266  *
 267  * mark tcp session as reconnecting so temporarily locked
 268  * mark all smb sessions as reconnecting for tcp session
 269  * reconnect tcp session
 270  * wake up waiters on reconnection? - (not needed currently)
 271  */
 272 static int __cifs_reconnect(struct TCP_Server_Info *server)
 273 {
 274         int rc = 0;
 275
 276         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 277                 return 0;
 278
 279         cifs_mark_tcp_ses_conns_for_reconnect(server);
 280
 281         do {
 282                 try_to_freeze();
 283                 mutex_lock(&server->srv_mutex);
 284
 285                 if (!cifs_swn_set_server_dstaddr(server)) {
 286                         /* resolve the hostname again to make sure that IP address is up-to-date */
 287                         rc = reconn_set_ipaddr_from_hostname(server);
 288                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 289                 }
 290
 291                 if (cifs_rdma_enabled(server))
 292                         rc = smbd_reconnect(server);
 293                 else
 294                         rc = generic_ip_connect(server);
 295                 if (rc) {
 296                         mutex_unlock(&server->srv_mutex);
 297                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 298                         msleep(3000);
 299                 } else {
 300                         atomic_inc(&tcpSesReconnectCount);
 301                         set_credits(server, 1);
 302                         spin_lock(&GlobalMid_Lock);
 303                         if (server->tcpStatus != CifsExiting)
 304                                 server->tcpStatus = CifsNeedNegotiate;
 305                         spin_unlock(&GlobalMid_Lock);
 306                         cifs_swn_reset_server_dstaddr(server);
 307                         mutex_unlock(&server->srv_mutex);
 308                 }
 309         } while (server->tcpStatus == CifsNeedReconnect);
 310
 311         if (server->tcpStatus == CifsNeedNegotiate)
 312                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 313
 314         wake_up(&server->response_q);
 315         return rc;
 316 }
 317
 318 #ifdef CONFIG_CIFS_DFS_UPCALL
 319 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 320 {
 321         int rc;
 322         char *hostname;
 323
 324         if (!cifs_swn_set_server_dstaddr(server)) {
 325                 if (server->hostname != target) {
 326                         hostname = extract_hostname(target);
 327                         if (!IS_ERR(hostname)) {
 328                                 kfree(server->hostname);
 329                                 server->hostname = hostname;
 330                         } else {
 331                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 332                                          __func__, PTR_ERR(hostname));
 333                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 334                                          server->hostname);
 335                         }
 336                 }
 337                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 338                 rc = reconn_set_ipaddr_from_hostname(server);
 339                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 340         }
 341         /* Reconnect the socket */
 342         if (cifs_rdma_enabled(server))
 343                 rc = smbd_reconnect(server);
 344         else
 345                 rc = generic_ip_connect(server);
 346
 347         return rc;
 348 }
 349
 350 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 351                                      struct dfs_cache_tgt_iterator **target_hint)
 352 {
 353         int rc;
 354         struct dfs_cache_tgt_iterator *tit;
 355
 356         *target_hint = NULL;
 357
 358         /* If dfs target list is empty, then reconnect to last server */
 359         tit = dfs_cache_get_tgt_iterator(tl);
 360         if (!tit)
 361                 return __reconnect_target_unlocked(server, server->hostname);
 362
 363         /* Otherwise, try every dfs target in @tl */
 364         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 365                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 366                 if (!rc) {
 367                         *target_hint = tit;
 368                         break;
 369                 }
 370         }
 371         return rc;
 372 }
 373
 374 static int reconnect_dfs_server(struct TCP_Server_Info *server)
 375 {
 376         int rc = 0;
 377         const char *refpath = server->current_fullpath + 1;
 378         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 379         struct dfs_cache_tgt_iterator *target_hint = NULL;
 380         int num_targets = 0;
 381
 382         /*
 383          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 384          *
 385          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 386          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 387          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 388          * refreshing the referral, so, in this case, default it to 1.
 389          */
 390         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 391                 num_targets = dfs_cache_get_nr_tgts(&tl);
 392         if (!num_targets)
 393                 num_targets = 1;
 394
 395         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 396                 return 0;
 397
 398         cifs_mark_tcp_ses_conns_for_reconnect(server);
 399
 400         do {
 401                 try_to_freeze();
 402                 mutex_lock(&server->srv_mutex);
 403
 404                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 405                 if (rc) {
 406                         /* Failed to reconnect socket */
 407                         mutex_unlock(&server->srv_mutex);
 408                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 409                         msleep(3000);
 410                         continue;
 411                 }
 412                 /*
 413                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 414                  * process waiting for reconnect will know it needs to re-establish session and tcon
 415                  * through the reconnected target server.
 416                  */
 417                 atomic_inc(&tcpSesReconnectCount);
 418                 set_credits(server, 1);
 419                 spin_lock(&GlobalMid_Lock);
 420                 if (server->tcpStatus != CifsExiting)
 421                         server->tcpStatus = CifsNeedNegotiate;
 422                 spin_unlock(&GlobalMid_Lock);
 423                 cifs_swn_reset_server_dstaddr(server);
 424                 mutex_unlock(&server->srv_mutex);
 425         } while (server->tcpStatus == CifsNeedReconnect);
 426
 427         if (target_hint)
 428                 dfs_cache_noreq_update_tgthint(refpath, target_hint);
 429
 430         dfs_cache_free_tgts(&tl);
 431
 432         /* Need to set up echo worker again once connection has been established */
 433         if (server->tcpStatus == CifsNeedNegotiate)
 434                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 435
 436         wake_up(&server->response_q);
 437         return rc;
 438 }
 439
 440 int cifs_reconnect(struct TCP_Server_Info *server)
 441 {
 442         /* If tcp session is not an dfs connection, then reconnect to last target server */
 443         spin_lock(&cifs_tcp_ses_lock);
 444         if (!server->is_dfs_conn || !server->origin_fullpath || !server->leaf_fullpath) {
 445                 spin_unlock(&cifs_tcp_ses_lock);
 446                 return __cifs_reconnect(server);
 447         }
 448         spin_unlock(&cifs_tcp_ses_lock);
 449
 450         return reconnect_dfs_server(server);
 451 }
 452 #else
 453 int cifs_reconnect(struct TCP_Server_Info *server)
 454 {
 455         return __cifs_reconnect(server);
 456 }
 457 #endif
 458
 459 static void
 460 cifs_echo_request(struct work_struct *work)
 461 {
 462         int rc;
 463         struct TCP_Server_Info *server = container_of(work,
 464                                         struct TCP_Server_Info, echo.work);
 465
 466         /*
 467          * We cannot send an echo if it is disabled.
 468          * Also, no need to ping if we got a response recently.
 469          */
 470
 471         if (server->tcpStatus == CifsNeedReconnect ||
 472             server->tcpStatus == CifsExiting ||
 473             server->tcpStatus == CifsNew ||
 474             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 475             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 476                 goto requeue_echo;
 477
 478         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 479         if (rc)
 480                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 481                          server->hostname);
 482
 483         /* Check witness registrations */
 484         cifs_swn_check();
 485
 486 requeue_echo:
 487         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 488 }
 489
 490 static bool
 491 allocate_buffers(struct TCP_Server_Info *server)
 492 {
 493         if (!server->bigbuf) {
 494                 server->bigbuf = (char *)cifs_buf_get();
 495                 if (!server->bigbuf) {
 496                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 497                         msleep(3000);
 498                         /* retry will check if exiting */
 499                         return false;
 500                 }
 501         } else if (server->large_buf) {
 502                 /* we are reusing a dirty large buf, clear its start */
 503                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 504         }
 505
 506         if (!server->smallbuf) {
 507                 server->smallbuf = (char *)cifs_small_buf_get();
 508                 if (!server->smallbuf) {
 509                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 510                         msleep(1000);
 511                         /* retry will check if exiting */
 512                         return false;
 513                 }
 514                 /* beginning of smb buffer is cleared in our buf_get */
 515         } else {
 516                 /* if existing small buf clear beginning */
 517                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 518         }
 519
 520         return true;
 521 }
 522
 523 static bool
 524 server_unresponsive(struct TCP_Server_Info *server)
 525 {
 526         /*
 527          * We need to wait 3 echo intervals to make sure we handle such
 528          * situations right:
 529          * 1s  client sends a normal SMB request
 530          * 2s  client gets a response
 531          * 30s echo workqueue job pops, and decides we got a response recently
 532          *     and don't need to send another
 533          * ...
 534          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 535          *     a response in >60s.
 536          */
 537         if ((server->tcpStatus == CifsGood ||
 538             server->tcpStatus == CifsNeedNegotiate) &&
 539             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 540             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 541                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 542                          (3 * server->echo_interval) / HZ);
 543                 cifs_reconnect(server);
 544                 return true;
 545         }
 546
 547         return false;
 548 }
 549
 550 static inline bool
 551 zero_credits(struct TCP_Server_Info *server)
 552 {
 553         int val;
 554
 555         spin_lock(&server->req_lock);
 556         val = server->credits + server->echo_credits + server->oplock_credits;
 557         if (server->in_flight == 0 && val == 0) {
 558                 spin_unlock(&server->req_lock);
 559                 return true;
 560         }
 561         spin_unlock(&server->req_lock);
 562         return false;
 563 }
 564
 565 static int
 566 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 567 {
 568         int length = 0;
 569         int total_read;
 570
 571         smb_msg->msg_control = NULL;
 572         smb_msg->msg_controllen = 0;
 573
 574         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 575                 try_to_freeze();
 576
 577                 /* reconnect if no credits and no requests in flight */
 578                 if (zero_credits(server)) {
 579                         cifs_reconnect(server);
 580                         return -ECONNABORTED;
 581                 }
 582
 583                 if (server_unresponsive(server))
 584                         return -ECONNABORTED;
 585                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 586                         length = smbd_recv(server->smbd_conn, smb_msg);
 587                 else
 588                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 589
 590                 if (server->tcpStatus == CifsExiting)
 591                         return -ESHUTDOWN;
 592
 593                 if (server->tcpStatus == CifsNeedReconnect) {
 594                         cifs_reconnect(server);
 595                         return -ECONNABORTED;
 596                 }
 597
 598                 if (length == -ERESTARTSYS ||
 599                     length == -EAGAIN ||
 600                     length == -EINTR) {
 601                         /*
 602                          * Minimum sleep to prevent looping, allowing socket
 603                          * to clear and app threads to set tcpStatus
 604                          * CifsNeedReconnect if server hung.
 605                          */
 606                         usleep_range(1000, 2000);
 607                         length = 0;
 608                         continue;
 609                 }
 610
 611                 if (length <= 0) {
 612                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 613                         cifs_reconnect(server);
 614                         return -ECONNABORTED;
 615                 }
 616         }
 617         return total_read;
 618 }
 619
 620 int
 621 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 622                       unsigned int to_read)
 623 {
 624         struct msghdr smb_msg;
 625         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 626         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 627
 628         return cifs_readv_from_socket(server, &smb_msg);
 629 }
 630
 631 ssize_t
 632 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 633 {
 634         struct msghdr smb_msg;
 635
 636         /*
 637          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 638          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 639          *  so little to initialize in struct msghdr
 640          */
 641         smb_msg.msg_name = NULL;
 642         smb_msg.msg_namelen = 0;
 643         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 644
 645         return cifs_readv_from_socket(server, &smb_msg);
 646 }
 647
 648 int
 649 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 650         unsigned int page_offset, unsigned int to_read)
 651 {
 652         struct msghdr smb_msg;
 653         struct bio_vec bv = {
 654                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 655         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 656         return cifs_readv_from_socket(server, &smb_msg);
 657 }
 658
 659 static bool
 660 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 661 {
 662         /*
 663          * The first byte big endian of the length field,
 664          * is actually not part of the length but the type
 665          * with the most common, zero, as regular data.
 666          */
 667         switch (type) {
 668         case RFC1002_SESSION_MESSAGE:
 669                 /* Regular SMB response */
 670                 return true;
 671         case RFC1002_SESSION_KEEP_ALIVE:
 672                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 673                 break;
 674         case RFC1002_POSITIVE_SESSION_RESPONSE:
 675                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 676                 break;
 677         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 678                 /*
 679                  * We get this from Windows 98 instead of an error on
 680                  * SMB negprot response.
 681                  */
 682                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 683                 /* give server a second to clean up */
 684                 msleep(1000);
 685                 /*
 686                  * Always try 445 first on reconnect since we get NACK
 687                  * on some if we ever connected to port 139 (the NACK
 688                  * is since we do not begin with RFC1001 session
 689                  * initialize frame).
 690                  */
 691                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 692                 cifs_reconnect(server);
 693                 break;
 694         default:
 695                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 696                 cifs_reconnect(server);
 697         }
 698
 699         return false;
 700 }
 701
 702 void
 703 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 704 {
 705 #ifdef CONFIG_CIFS_STATS2
 706         mid->when_received = jiffies;
 707 #endif
 708         spin_lock(&GlobalMid_Lock);
 709         if (!malformed)
 710                 mid->mid_state = MID_RESPONSE_RECEIVED;
 711         else
 712                 mid->mid_state = MID_RESPONSE_MALFORMED;
 713         /*
 714          * Trying to handle/dequeue a mid after the send_recv()
 715          * function has finished processing it is a bug.
 716          */
 717         if (mid->mid_flags & MID_DELETED) {
 718                 spin_unlock(&GlobalMid_Lock);
 719                 pr_warn_once("trying to dequeue a deleted mid\n");
 720         } else {
 721                 list_del_init(&mid->qhead);
 722                 mid->mid_flags |= MID_DELETED;
 723                 spin_unlock(&GlobalMid_Lock);
 724         }
 725 }
 726
 727 static unsigned int
 728 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 729 {
 730         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 731
 732         /*
 733          * SMB1 does not use credits.
 734          */
 735         if (server->vals->header_preamble_size)
 736                 return 0;
 737
 738         return le16_to_cpu(shdr->CreditRequest);
 739 }
 740
 741 static void
 742 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 743            char *buf, int malformed)
 744 {
 745         if (server->ops->check_trans2 &&
 746             server->ops->check_trans2(mid, server, buf, malformed))
 747                 return;
 748         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 749         mid->resp_buf = buf;
 750         mid->large_buf = server->large_buf;
 751         /* Was previous buf put in mpx struct for multi-rsp? */
 752         if (!mid->multiRsp) {
 753                 /* smb buffer will be freed by user thread */
 754                 if (server->large_buf)
 755                         server->bigbuf = NULL;
 756                 else
 757                         server->smallbuf = NULL;
 758         }
 759         dequeue_mid(mid, malformed);
 760 }
 761
 762 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 763 {
 764         int length;
 765
 766         /* take it off the list, if it's not already */
 767         spin_lock(&cifs_tcp_ses_lock);
 768         list_del_init(&server->tcp_ses_list);
 769         spin_unlock(&cifs_tcp_ses_lock);
 770
 771         cancel_delayed_work_sync(&server->echo);
 772         cancel_delayed_work_sync(&server->resolve);
 773
 774         spin_lock(&GlobalMid_Lock);
 775         server->tcpStatus = CifsExiting;
 776         spin_unlock(&GlobalMid_Lock);
 777         wake_up_all(&server->response_q);
 778
 779         /* check if we have blocked requests that need to free */
 780         spin_lock(&server->req_lock);
 781         if (server->credits <= 0)
 782                 server->credits = 1;
 783         spin_unlock(&server->req_lock);
 784         /*
 785          * Although there should not be any requests blocked on this queue it
 786          * can not hurt to be paranoid and try to wake up requests that may
 787          * haven been blocked when more than 50 at time were on the wire to the
 788          * same server - they now will see the session is in exit state and get
 789          * out of SendReceive.
 790          */
 791         wake_up_all(&server->request_q);
 792         /* give those requests time to exit */
 793         msleep(125);
 794         if (cifs_rdma_enabled(server))
 795                 smbd_destroy(server);
 796         if (server->ssocket) {
 797                 sock_release(server->ssocket);
 798                 server->ssocket = NULL;
 799         }
 800
 801         if (!list_empty(&server->pending_mid_q)) {
 802                 struct list_head dispose_list;
 803                 struct mid_q_entry *mid_entry;
 804                 struct list_head *tmp, *tmp2;
 805
 806                 INIT_LIST_HEAD(&dispose_list);
 807                 spin_lock(&GlobalMid_Lock);
 808                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 809                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 810                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 811                         kref_get(&mid_entry->refcount);
 812                         mid_entry->mid_state = MID_SHUTDOWN;
 813                         list_move(&mid_entry->qhead, &dispose_list);
 814                         mid_entry->mid_flags |= MID_DELETED;
 815                 }
 816                 spin_unlock(&GlobalMid_Lock);
 817
 818                 /* now walk dispose list and issue callbacks */
 819                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 820                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 821                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 822                         list_del_init(&mid_entry->qhead);
 823                         mid_entry->callback(mid_entry);
 824                         cifs_mid_q_entry_release(mid_entry);
 825                 }
 826                 /* 1/8th of sec is more than enough time for them to exit */
 827                 msleep(125);
 828         }
 829
 830         if (!list_empty(&server->pending_mid_q)) {
 831                 /*
 832                  * mpx threads have not exited yet give them at least the smb
 833                  * send timeout time for long ops.
 834                  *
 835                  * Due to delays on oplock break requests, we need to wait at
 836                  * least 45 seconds before giving up on a request getting a
 837                  * response and going ahead and killing cifsd.
 838                  */
 839                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 840                 msleep(46000);
 841                 /*
 842                  * If threads still have not exited they are probably never
 843                  * coming home not much else we can do but free the memory.
 844                  */
 845         }
 846
 847 #ifdef CONFIG_CIFS_DFS_UPCALL
 848         kfree(server->origin_fullpath);
 849         kfree(server->leaf_fullpath);
 850 #endif
 851         kfree(server);
 852
 853         length = atomic_dec_return(&tcpSesAllocCount);
 854         if (length > 0)
 855                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 856 }
 857
 858 static int
 859 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 860 {
 861         int length;
 862         char *buf = server->smallbuf;
 863         unsigned int pdu_length = server->pdu_size;
 864
 865         /* make sure this will fit in a large buffer */
 866         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
 867                 server->vals->header_preamble_size) {
 868                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 869                 cifs_reconnect(server);
 870                 return -ECONNABORTED;
 871         }
 872
 873         /* switch to large buffer if too big for a small one */
 874         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
 875                 server->large_buf = true;
 876                 memcpy(server->bigbuf, buf, server->total_read);
 877                 buf = server->bigbuf;
 878         }
 879
 880         /* now read the rest */
 881         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
 882                                        pdu_length - HEADER_SIZE(server) + 1
 883                                        + server->vals->header_preamble_size);
 884
 885         if (length < 0)
 886                 return length;
 887         server->total_read += length;
 888
 889         dump_smb(buf, server->total_read);
 890
 891         return cifs_handle_standard(server, mid);
 892 }
 893
 894 int
 895 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 896 {
 897         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
 898         int length;
 899
 900         /*
 901          * We know that we received enough to get to the MID as we
 902          * checked the pdu_length earlier. Now check to see
 903          * if the rest of the header is OK. We borrow the length
 904          * var for the rest of the loop to avoid a new stack var.
 905          *
 906          * 48 bytes is enough to display the header and a little bit
 907          * into the payload for debugging purposes.
 908          */
 909         length = server->ops->check_message(buf, server->total_read, server);
 910         if (length != 0)
 911                 cifs_dump_mem("Bad SMB: ", buf,
 912                         min_t(unsigned int, server->total_read, 48));
 913
 914         if (server->ops->is_session_expired &&
 915             server->ops->is_session_expired(buf)) {
 916                 cifs_reconnect(server);
 917                 return -1;
 918         }
 919
 920         if (server->ops->is_status_pending &&
 921             server->ops->is_status_pending(buf, server))
 922                 return -1;
 923
 924         if (!mid)
 925                 return length;
 926
 927         handle_mid(mid, server, buf, length);
 928         return 0;
 929 }
 930
 931 static void
 932 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 933 {
 934         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 935         int scredits, in_flight;
 936
 937         /*
 938          * SMB1 does not use credits.
 939          */
 940         if (server->vals->header_preamble_size)
 941                 return;
 942
 943         if (shdr->CreditRequest) {
 944                 spin_lock(&server->req_lock);
 945                 server->credits += le16_to_cpu(shdr->CreditRequest);
 946                 scredits = server->credits;
 947                 in_flight = server->in_flight;
 948                 spin_unlock(&server->req_lock);
 949                 wake_up(&server->request_q);
 950
 951                 trace_smb3_add_credits(server->CurrentMid,
 952                                 server->conn_id, server->hostname, scredits,
 953                                 le16_to_cpu(shdr->CreditRequest), in_flight);
 954                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
 955                                 __func__, le16_to_cpu(shdr->CreditRequest),
 956                                 scredits);
 957         }
 958 }
 959
 960
 961 static int
 962 cifs_demultiplex_thread(void *p)
 963 {
 964         int i, num_mids, length;
 965         struct TCP_Server_Info *server = p;
 966         unsigned int pdu_length;
 967         unsigned int next_offset;
 968         char *buf = NULL;
 969         struct task_struct *task_to_wake = NULL;
 970         struct mid_q_entry *mids[MAX_COMPOUND];
 971         char *bufs[MAX_COMPOUND];
 972         unsigned int noreclaim_flag, num_io_timeout = 0;
 973
 974         noreclaim_flag = memalloc_noreclaim_save();
 975         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
 976
 977         length = atomic_inc_return(&tcpSesAllocCount);
 978         if (length > 1)
 979                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 980
 981         set_freezable();
 982         allow_kernel_signal(SIGKILL);
 983         while (server->tcpStatus != CifsExiting) {
 984                 if (try_to_freeze())
 985                         continue;
 986
 987                 if (!allocate_buffers(server))
 988                         continue;
 989
 990                 server->large_buf = false;
 991                 buf = server->smallbuf;
 992                 pdu_length = 4; /* enough to get RFC1001 header */
 993
 994                 length = cifs_read_from_socket(server, buf, pdu_length);
 995                 if (length < 0)
 996                         continue;
 997
 998                 if (server->vals->header_preamble_size == 0)
 999                         server->total_read = 0;
1000                 else
1001                         server->total_read = length;
1002
1003                 /*
1004                  * The right amount was read from socket - 4 bytes,
1005                  * so we can now interpret the length field.
1006                  */
1007                 pdu_length = get_rfc1002_length(buf);
1008
1009                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1010                 if (!is_smb_response(server, buf[0]))
1011                         continue;
1012 next_pdu:
1013                 server->pdu_size = pdu_length;
1014
1015                 /* make sure we have enough to get to the MID */
1016                 if (server->pdu_size < HEADER_SIZE(server) - 1 -
1017                     server->vals->header_preamble_size) {
1018                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1019                                  server->pdu_size);
1020                         cifs_reconnect(server);
1021                         continue;
1022                 }
1023
1024                 /* read down to the MID */
1025                 length = cifs_read_from_socket(server,
1026                              buf + server->vals->header_preamble_size,
1027                              HEADER_SIZE(server) - 1
1028                              - server->vals->header_preamble_size);
1029                 if (length < 0)
1030                         continue;
1031                 server->total_read += length;
1032
1033                 if (server->ops->next_header) {
1034                         next_offset = server->ops->next_header(buf);
1035                         if (next_offset)
1036                                 server->pdu_size = next_offset;
1037                 }
1038
1039                 memset(mids, 0, sizeof(mids));
1040                 memset(bufs, 0, sizeof(bufs));
1041                 num_mids = 0;
1042
1043                 if (server->ops->is_transform_hdr &&
1044                     server->ops->receive_transform &&
1045                     server->ops->is_transform_hdr(buf)) {
1046                         length = server->ops->receive_transform(server,
1047                                                                 mids,
1048                                                                 bufs,
1049                                                                 &num_mids);
1050                 } else {
1051                         mids[0] = server->ops->find_mid(server, buf);
1052                         bufs[0] = buf;
1053                         num_mids = 1;
1054
1055                         if (!mids[0] || !mids[0]->receive)
1056                                 length = standard_receive3(server, mids[0]);
1057                         else
1058                                 length = mids[0]->receive(server, mids[0]);
1059                 }
1060
1061                 if (length < 0) {
1062                         for (i = 0; i < num_mids; i++)
1063                                 if (mids[i])
1064                                         cifs_mid_q_entry_release(mids[i]);
1065                         continue;
1066                 }
1067
1068                 if (server->ops->is_status_io_timeout &&
1069                     server->ops->is_status_io_timeout(buf)) {
1070                         num_io_timeout++;
1071                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1072                                 cifs_reconnect(server);
1073                                 num_io_timeout = 0;
1074                                 continue;
1075                         }
1076                 }
1077
1078                 server->lstrp = jiffies;
1079
1080                 for (i = 0; i < num_mids; i++) {
1081                         if (mids[i] != NULL) {
1082                                 mids[i]->resp_buf_size = server->pdu_size;
1083
1084                                 if (bufs[i] && server->ops->is_network_name_deleted)
1085                                         server->ops->is_network_name_deleted(bufs[i],
1086                                                                         server);
1087
1088                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1089                                         mids[i]->callback(mids[i]);
1090
1091                                 cifs_mid_q_entry_release(mids[i]);
1092                         } else if (server->ops->is_oplock_break &&
1093                                    server->ops->is_oplock_break(bufs[i],
1094                                                                 server)) {
1095                                 smb2_add_credits_from_hdr(bufs[i], server);
1096                                 cifs_dbg(FYI, "Received oplock break\n");
1097                         } else {
1098                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1099                                                 atomic_read(&midCount));
1100                                 cifs_dump_mem("Received Data is: ", bufs[i],
1101                                               HEADER_SIZE(server));
1102                                 smb2_add_credits_from_hdr(bufs[i], server);
1103 #ifdef CONFIG_CIFS_DEBUG2
1104                                 if (server->ops->dump_detail)
1105                                         server->ops->dump_detail(bufs[i],
1106                                                                  server);
1107                                 cifs_dump_mids(server);
1108 #endif /* CIFS_DEBUG2 */
1109                         }
1110                 }
1111
1112                 if (pdu_length > server->pdu_size) {
1113                         if (!allocate_buffers(server))
1114                                 continue;
1115                         pdu_length -= server->pdu_size;
1116                         server->total_read = 0;
1117                         server->large_buf = false;
1118                         buf = server->smallbuf;
1119                         goto next_pdu;
1120                 }
1121         } /* end while !EXITING */
1122
1123         /* buffer usually freed in free_mid - need to free it here on exit */
1124         cifs_buf_release(server->bigbuf);
1125         if (server->smallbuf) /* no sense logging a debug message if NULL */
1126                 cifs_small_buf_release(server->smallbuf);
1127
1128         task_to_wake = xchg(&server->tsk, NULL);
1129         clean_demultiplex_info(server);
1130
1131         /* if server->tsk was NULL then wait for a signal before exiting */
1132         if (!task_to_wake) {
1133                 set_current_state(TASK_INTERRUPTIBLE);
1134                 while (!signal_pending(current)) {
1135                         schedule();
1136                         set_current_state(TASK_INTERRUPTIBLE);
1137                 }
1138                 set_current_state(TASK_RUNNING);
1139         }
1140
1141         memalloc_noreclaim_restore(noreclaim_flag);
1142         module_put_and_exit(0);
1143 }
1144
1145 /*
1146  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1147  * if srcaddr is specified and matches the IP address of the rhs argument
1148  */
1149 bool
1150 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1151 {
1152         switch (srcaddr->sa_family) {
1153         case AF_UNSPEC:
1154                 return (rhs->sa_family == AF_UNSPEC);
1155         case AF_INET: {
1156                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1157                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1158                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1159         }
1160         case AF_INET6: {
1161                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1162                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1163                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1164         }
1165         default:
1166                 WARN_ON(1);
1167                 return false; /* don't expect to be here */
1168         }
1169 }
1170
1171 /*
1172  * If no port is specified in addr structure, we try to match with 445 port
1173  * and if it fails - with 139 ports. It should be called only if address
1174  * families of server and addr are equal.
1175  */
1176 static bool
1177 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1178 {
1179         __be16 port, *sport;
1180
1181         /* SMBDirect manages its own ports, don't match it here */
1182         if (server->rdma)
1183                 return true;
1184
1185         switch (addr->sa_family) {
1186         case AF_INET:
1187                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1188                 port = ((struct sockaddr_in *) addr)->sin_port;
1189                 break;
1190         case AF_INET6:
1191                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1192                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1193                 break;
1194         default:
1195                 WARN_ON(1);
1196                 return false;
1197         }
1198
1199         if (!port) {
1200                 port = htons(CIFS_PORT);
1201                 if (port == *sport)
1202                         return true;
1203
1204                 port = htons(RFC1001_PORT);
1205         }
1206
1207         return port == *sport;
1208 }
1209
1210 static bool
1211 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1212               struct sockaddr *srcaddr)
1213 {
1214         switch (addr->sa_family) {
1215         case AF_INET: {
1216                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1217                 struct sockaddr_in *srv_addr4 =
1218                                         (struct sockaddr_in *)&server->dstaddr;
1219
1220                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1221                         return false;
1222                 break;
1223         }
1224         case AF_INET6: {
1225                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1226                 struct sockaddr_in6 *srv_addr6 =
1227                                         (struct sockaddr_in6 *)&server->dstaddr;
1228
1229                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1230                                      &srv_addr6->sin6_addr))
1231                         return false;
1232                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1233                         return false;
1234                 break;
1235         }
1236         default:
1237                 WARN_ON(1);
1238                 return false; /* don't expect to be here */
1239         }
1240
1241         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1242                 return false;
1243
1244         return true;
1245 }
1246
1247 static bool
1248 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1249 {
1250         /*
1251          * The select_sectype function should either return the ctx->sectype
1252          * that was specified, or "Unspecified" if that sectype was not
1253          * compatible with the given NEGOTIATE request.
1254          */
1255         if (server->ops->select_sectype(server, ctx->sectype)
1256              == Unspecified)
1257                 return false;
1258
1259         /*
1260          * Now check if signing mode is acceptable. No need to check
1261          * global_secflags at this point since if MUST_SIGN is set then
1262          * the server->sign had better be too.
1263          */
1264         if (ctx->sign && !server->sign)
1265                 return false;
1266
1267         return true;
1268 }
1269
1270 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1271 {
1272         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1273
1274         if (ctx->nosharesock)
1275                 return 0;
1276
1277         /* this server does not share socket */
1278         if (server->nosharesock)
1279                 return 0;
1280
1281         /* If multidialect negotiation see if existing sessions match one */
1282         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1283                 if (server->vals->protocol_id < SMB30_PROT_ID)
1284                         return 0;
1285         } else if (strcmp(ctx->vals->version_string,
1286                    SMBDEFAULT_VERSION_STRING) == 0) {
1287                 if (server->vals->protocol_id < SMB21_PROT_ID)
1288                         return 0;
1289         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1290                 return 0;
1291
1292         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1293                 return 0;
1294
1295         if (strcasecmp(server->hostname, ctx->server_hostname))
1296                 return 0;
1297
1298         if (!match_address(server, addr,
1299                            (struct sockaddr *)&ctx->srcaddr))
1300                 return 0;
1301
1302         if (!match_port(server, addr))
1303                 return 0;
1304
1305         if (!match_security(server, ctx))
1306                 return 0;
1307
1308         if (server->echo_interval != ctx->echo_interval * HZ)
1309                 return 0;
1310
1311         if (server->rdma != ctx->rdma)
1312                 return 0;
1313
1314         if (server->ignore_signature != ctx->ignore_signature)
1315                 return 0;
1316
1317         if (server->min_offload != ctx->min_offload)
1318                 return 0;
1319
1320         return 1;
1321 }
1322
1323 struct TCP_Server_Info *
1324 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1325 {
1326         struct TCP_Server_Info *server;
1327
1328         spin_lock(&cifs_tcp_ses_lock);
1329         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1330 #ifdef CONFIG_CIFS_DFS_UPCALL
1331                 /*
1332                  * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
1333                  * DFS connections to do failover properly, so avoid sharing them with regular
1334                  * shares or even links that may connect to same server but having completely
1335                  * different failover targets.
1336                  */
1337                 if (server->is_dfs_conn)
1338                         continue;
1339 #endif
1340                 /*
1341                  * Skip ses channels since they're only handled in lower layers
1342                  * (e.g. cifs_send_recv).
1343                  */
1344                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx))
1345                         continue;
1346
1347                 ++server->srv_count;
1348                 spin_unlock(&cifs_tcp_ses_lock);
1349                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1350                 return server;
1351         }
1352         spin_unlock(&cifs_tcp_ses_lock);
1353         return NULL;
1354 }
1355
1356 void
1357 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1358 {
1359         struct task_struct *task;
1360
1361         spin_lock(&cifs_tcp_ses_lock);
1362         if (--server->srv_count > 0) {
1363                 spin_unlock(&cifs_tcp_ses_lock);
1364                 return;
1365         }
1366
1367         /* srv_count can never go negative */
1368         WARN_ON(server->srv_count < 0);
1369
1370         put_net(cifs_net_ns(server));
1371
1372         list_del_init(&server->tcp_ses_list);
1373         spin_unlock(&cifs_tcp_ses_lock);
1374
1375         /* For secondary channels, we pick up ref-count on the primary server */
1376         if (CIFS_SERVER_IS_CHAN(server))
1377                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1378
1379         cancel_delayed_work_sync(&server->echo);
1380         cancel_delayed_work_sync(&server->resolve);
1381
1382         if (from_reconnect)
1383                 /*
1384                  * Avoid deadlock here: reconnect work calls
1385                  * cifs_put_tcp_session() at its end. Need to be sure
1386                  * that reconnect work does nothing with server pointer after
1387                  * that step.
1388                  */
1389                 cancel_delayed_work(&server->reconnect);
1390         else
1391                 cancel_delayed_work_sync(&server->reconnect);
1392
1393         spin_lock(&GlobalMid_Lock);
1394         server->tcpStatus = CifsExiting;
1395         spin_unlock(&GlobalMid_Lock);
1396
1397         cifs_crypto_secmech_release(server);
1398
1399         /* fscache server cookies are based on primary channel only */
1400         if (!CIFS_SERVER_IS_CHAN(server))
1401                 cifs_fscache_release_client_cookie(server);
1402
1403         kfree(server->session_key.response);
1404         server->session_key.response = NULL;
1405         server->session_key.len = 0;
1406         kfree(server->hostname);
1407
1408         task = xchg(&server->tsk, NULL);
1409         if (task)
1410                 send_sig(SIGKILL, task, 1);
1411 }
1412
1413 struct TCP_Server_Info *
1414 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1415                      struct TCP_Server_Info *primary_server)
1416 {
1417         struct TCP_Server_Info *tcp_ses = NULL;
1418         int rc;
1419
1420         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1421
1422         /* see if we already have a matching tcp_ses */
1423         tcp_ses = cifs_find_tcp_session(ctx);
1424         if (tcp_ses)
1425                 return tcp_ses;
1426
1427         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1428         if (!tcp_ses) {
1429                 rc = -ENOMEM;
1430                 goto out_err;
1431         }
1432
1433         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1434         if (!tcp_ses->hostname) {
1435                 rc = -ENOMEM;
1436                 goto out_err;
1437         }
1438
1439         if (ctx->nosharesock)
1440                 tcp_ses->nosharesock = true;
1441
1442         tcp_ses->ops = ctx->ops;
1443         tcp_ses->vals = ctx->vals;
1444         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1445
1446         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1447         tcp_ses->noblockcnt = ctx->rootfs;
1448         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1449         tcp_ses->noautotune = ctx->noautotune;
1450         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1451         tcp_ses->rdma = ctx->rdma;
1452         tcp_ses->in_flight = 0;
1453         tcp_ses->max_in_flight = 0;
1454         tcp_ses->credits = 1;
1455         if (primary_server) {
1456                 spin_lock(&cifs_tcp_ses_lock);
1457                 ++primary_server->srv_count;
1458                 tcp_ses->primary_server = primary_server;
1459                 spin_unlock(&cifs_tcp_ses_lock);
1460         }
1461         init_waitqueue_head(&tcp_ses->response_q);
1462         init_waitqueue_head(&tcp_ses->request_q);
1463         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1464         mutex_init(&tcp_ses->srv_mutex);
1465         memcpy(tcp_ses->workstation_RFC1001_name,
1466                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1467         memcpy(tcp_ses->server_RFC1001_name,
1468                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1469         tcp_ses->session_estab = false;
1470         tcp_ses->sequence_number = 0;
1471         tcp_ses->reconnect_instance = 1;
1472         tcp_ses->lstrp = jiffies;
1473         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1474         spin_lock_init(&tcp_ses->req_lock);
1475         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1476         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1477         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1478         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1479         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1480         mutex_init(&tcp_ses->reconnect_mutex);
1481 #ifdef CONFIG_CIFS_DFS_UPCALL
1482         mutex_init(&tcp_ses->refpath_lock);
1483 #endif
1484         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1485                sizeof(tcp_ses->srcaddr));
1486         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1487                 sizeof(tcp_ses->dstaddr));
1488         if (ctx->use_client_guid)
1489                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1490                        SMB2_CLIENT_GUID_SIZE);
1491         else
1492                 generate_random_uuid(tcp_ses->client_guid);
1493         /*
1494          * at this point we are the only ones with the pointer
1495          * to the struct since the kernel thread not created yet
1496          * no need to spinlock this init of tcpStatus or srv_count
1497          */
1498         tcp_ses->tcpStatus = CifsNew;
1499         ++tcp_ses->srv_count;
1500
1501         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1502                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1503                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1504         else
1505                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1506         if (tcp_ses->rdma) {
1507 #ifndef CONFIG_CIFS_SMB_DIRECT
1508                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1509                 rc = -ENOENT;
1510                 goto out_err_crypto_release;
1511 #endif
1512                 tcp_ses->smbd_conn = smbd_get_connection(
1513                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1514                 if (tcp_ses->smbd_conn) {
1515                         cifs_dbg(VFS, "RDMA transport established\n");
1516                         rc = 0;
1517                         goto smbd_connected;
1518                 } else {
1519                         rc = -ENOENT;
1520                         goto out_err_crypto_release;
1521                 }
1522         }
1523         rc = ip_connect(tcp_ses);
1524         if (rc < 0) {
1525                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1526                 goto out_err_crypto_release;
1527         }
1528 smbd_connected:
1529         /*
1530          * since we're in a cifs function already, we know that
1531          * this will succeed. No need for try_module_get().
1532          */
1533         __module_get(THIS_MODULE);
1534         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1535                                   tcp_ses, "cifsd");
1536         if (IS_ERR(tcp_ses->tsk)) {
1537                 rc = PTR_ERR(tcp_ses->tsk);
1538                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1539                 module_put(THIS_MODULE);
1540                 goto out_err_crypto_release;
1541         }
1542         tcp_ses->min_offload = ctx->min_offload;
1543         /*
1544          * at this point we are the only ones with the pointer
1545          * to the struct since the kernel thread not created yet
1546          * no need to spinlock this update of tcpStatus
1547          */
1548         tcp_ses->tcpStatus = CifsNeedNegotiate;
1549
1550         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1551                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1552         else
1553                 tcp_ses->max_credits = ctx->max_credits;
1554
1555         tcp_ses->nr_targets = 1;
1556         tcp_ses->ignore_signature = ctx->ignore_signature;
1557         /* thread spawned, put it on the list */
1558         spin_lock(&cifs_tcp_ses_lock);
1559         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1560         spin_unlock(&cifs_tcp_ses_lock);
1561
1562         /* fscache server cookies are based on primary channel only */
1563         if (!CIFS_SERVER_IS_CHAN(tcp_ses))
1564                 cifs_fscache_get_client_cookie(tcp_ses);
1565 #ifdef CONFIG_CIFS_FSCACHE
1566         else
1567                 tcp_ses->fscache = tcp_ses->primary_server->fscache;
1568 #endif /* CONFIG_CIFS_FSCACHE */
1569
1570         /* queue echo request delayed work */
1571         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1572
1573         /* queue dns resolution delayed work */
1574         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1575                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1576
1577         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1578
1579         return tcp_ses;
1580
1581 out_err_crypto_release:
1582         cifs_crypto_secmech_release(tcp_ses);
1583
1584         put_net(cifs_net_ns(tcp_ses));
1585
1586 out_err:
1587         if (tcp_ses) {
1588                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1589                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1590                 kfree(tcp_ses->hostname);
1591                 if (tcp_ses->ssocket)
1592                         sock_release(tcp_ses->ssocket);
1593                 kfree(tcp_ses);
1594         }
1595         return ERR_PTR(rc);
1596 }
1597
1598 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1599 {
1600         if (ctx->sectype != Unspecified &&
1601             ctx->sectype != ses->sectype)
1602                 return 0;
1603
1604         /*
1605          * If an existing session is limited to less channels than
1606          * requested, it should not be reused
1607          */
1608         spin_lock(&ses->chan_lock);
1609         if (ses->chan_max < ctx->max_channels) {
1610                 spin_unlock(&ses->chan_lock);
1611                 return 0;
1612         }
1613         spin_unlock(&ses->chan_lock);
1614
1615         switch (ses->sectype) {
1616         case Kerberos:
1617                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1618                         return 0;
1619                 break;
1620         default:
1621                 /* NULL username means anonymous session */
1622                 if (ses->user_name == NULL) {
1623                         if (!ctx->nullauth)
1624                                 return 0;
1625                         break;
1626                 }
1627
1628                 /* anything else takes username/password */
1629                 if (strncmp(ses->user_name,
1630                             ctx->username ? ctx->username : "",
1631                             CIFS_MAX_USERNAME_LEN))
1632                         return 0;
1633                 if ((ctx->username && strlen(ctx->username) != 0) &&
1634                     ses->password != NULL &&
1635                     strncmp(ses->password,
1636                             ctx->password ? ctx->password : "",
1637                             CIFS_MAX_PASSWORD_LEN))
1638                         return 0;
1639         }
1640         return 1;
1641 }
1642
1643 /**
1644  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1645  * @ses: smb session to issue the request on
1646  * @ctx: the superblock configuration context to use for building the
1647  *       new tree connection for the IPC (interprocess communication RPC)
1648  *
1649  * A new IPC connection is made and stored in the session
1650  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1651  */
1652 static int
1653 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1654 {
1655         int rc = 0, xid;
1656         struct cifs_tcon *tcon;
1657         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1658         bool seal = false;
1659         struct TCP_Server_Info *server = ses->server;
1660
1661         /*
1662          * If the mount request that resulted in the creation of the
1663          * session requires encryption, force IPC to be encrypted too.
1664          */
1665         if (ctx->seal) {
1666                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1667                         seal = true;
1668                 else {
1669                         cifs_server_dbg(VFS,
1670                                  "IPC: server doesn't support encryption\n");
1671                         return -EOPNOTSUPP;
1672                 }
1673         }
1674
1675         tcon = tconInfoAlloc();
1676         if (tcon == NULL)
1677                 return -ENOMEM;
1678
1679         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1680
1681         xid = get_xid();
1682         tcon->ses = ses;
1683         tcon->ipc = true;
1684         tcon->seal = seal;
1685         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1686         free_xid(xid);
1687
1688         if (rc) {
1689                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1690                 tconInfoFree(tcon);
1691                 goto out;
1692         }
1693
1694         cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid);
1695
1696         ses->tcon_ipc = tcon;
1697 out:
1698         return rc;
1699 }
1700
1701 /**
1702  * cifs_free_ipc - helper to release the session IPC tcon
1703  * @ses: smb session to unmount the IPC from
1704  *
1705  * Needs to be called everytime a session is destroyed.
1706  *
1707  * On session close, the IPC is closed and the server must release all tcons of the session.
1708  * No need to send a tree disconnect here.
1709  *
1710  * Besides, it will make the server to not close durable and resilient files on session close, as
1711  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1712  */
1713 static int
1714 cifs_free_ipc(struct cifs_ses *ses)
1715 {
1716         struct cifs_tcon *tcon = ses->tcon_ipc;
1717
1718         if (tcon == NULL)
1719                 return 0;
1720
1721         tconInfoFree(tcon);
1722         ses->tcon_ipc = NULL;
1723         return 0;
1724 }
1725
1726 static struct cifs_ses *
1727 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1728 {
1729         struct cifs_ses *ses;
1730
1731         spin_lock(&cifs_tcp_ses_lock);
1732         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1733                 if (ses->status == CifsExiting)
1734                         continue;
1735                 if (!match_session(ses, ctx))
1736                         continue;
1737                 ++ses->ses_count;
1738                 spin_unlock(&cifs_tcp_ses_lock);
1739                 return ses;
1740         }
1741         spin_unlock(&cifs_tcp_ses_lock);
1742         return NULL;
1743 }
1744
1745 void cifs_put_smb_ses(struct cifs_ses *ses)
1746 {
1747         unsigned int rc, xid;
1748         unsigned int chan_count;
1749         struct TCP_Server_Info *server = ses->server;
1750         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1751
1752         spin_lock(&cifs_tcp_ses_lock);
1753         if (ses->status == CifsExiting) {
1754                 spin_unlock(&cifs_tcp_ses_lock);
1755                 return;
1756         }
1757
1758         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1759         cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE");
1760
1761         if (--ses->ses_count > 0) {
1762                 spin_unlock(&cifs_tcp_ses_lock);
1763                 return;
1764         }
1765         spin_unlock(&cifs_tcp_ses_lock);
1766
1767         /* ses_count can never go negative */
1768         WARN_ON(ses->ses_count < 0);
1769
1770         spin_lock(&GlobalMid_Lock);
1771         if (ses->status == CifsGood)
1772                 ses->status = CifsExiting;
1773         spin_unlock(&GlobalMid_Lock);
1774
1775         cifs_free_ipc(ses);
1776
1777         if (ses->status == CifsExiting && server->ops->logoff) {
1778                 xid = get_xid();
1779                 rc = server->ops->logoff(xid, ses);
1780                 if (rc)
1781                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1782                                 __func__, rc);
1783                 _free_xid(xid);
1784         }
1785
1786         spin_lock(&cifs_tcp_ses_lock);
1787         list_del_init(&ses->smb_ses_list);
1788         spin_unlock(&cifs_tcp_ses_lock);
1789
1790         spin_lock(&ses->chan_lock);
1791         chan_count = ses->chan_count;
1792         spin_unlock(&ses->chan_lock);
1793
1794         /* close any extra channels */
1795         if (chan_count > 1) {
1796                 int i;
1797
1798                 for (i = 1; i < chan_count; i++) {
1799                         /*
1800                          * note: for now, we're okay accessing ses->chans
1801                          * without chan_lock. But when chans can go away, we'll
1802                          * need to introduce ref counting to make sure that chan
1803                          * is not freed from under us.
1804                          */
1805                         cifs_put_tcp_session(ses->chans[i].server, 0);
1806                         ses->chans[i].server = NULL;
1807                 }
1808         }
1809
1810         sesInfoFree(ses);
1811         cifs_put_tcp_session(server, 0);
1812 }
1813
1814 #ifdef CONFIG_KEYS
1815
1816 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1817 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1818
1819 /* Populate username and pw fields from keyring if possible */
1820 static int
1821 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1822 {
1823         int rc = 0;
1824         int is_domain = 0;
1825         const char *delim, *payload;
1826         char *desc;
1827         ssize_t len;
1828         struct key *key;
1829         struct TCP_Server_Info *server = ses->server;
1830         struct sockaddr_in *sa;
1831         struct sockaddr_in6 *sa6;
1832         const struct user_key_payload *upayload;
1833
1834         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1835         if (!desc)
1836                 return -ENOMEM;
1837
1838         /* try to find an address key first */
1839         switch (server->dstaddr.ss_family) {
1840         case AF_INET:
1841                 sa = (struct sockaddr_in *)&server->dstaddr;
1842                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1843                 break;
1844         case AF_INET6:
1845                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1846                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1847                 break;
1848         default:
1849                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1850                          server->dstaddr.ss_family);
1851                 rc = -EINVAL;
1852                 goto out_err;
1853         }
1854
1855         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1856         key = request_key(&key_type_logon, desc, "");
1857         if (IS_ERR(key)) {
1858                 if (!ses->domainName) {
1859                         cifs_dbg(FYI, "domainName is NULL\n");
1860                         rc = PTR_ERR(key);
1861                         goto out_err;
1862                 }
1863
1864                 /* didn't work, try to find a domain key */
1865                 sprintf(desc, "cifs:d:%s", ses->domainName);
1866                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1867                 key = request_key(&key_type_logon, desc, "");
1868                 if (IS_ERR(key)) {
1869                         rc = PTR_ERR(key);
1870                         goto out_err;
1871                 }
1872                 is_domain = 1;
1873         }
1874
1875         down_read(&key->sem);
1876         upayload = user_key_payload_locked(key);
1877         if (IS_ERR_OR_NULL(upayload)) {
1878                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1879                 goto out_key_put;
1880         }
1881
1882         /* find first : in payload */
1883         payload = upayload->data;
1884         delim = strnchr(payload, upayload->datalen, ':');
1885         cifs_dbg(FYI, "payload=%s\n", payload);
1886         if (!delim) {
1887                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1888                          upayload->datalen);
1889                 rc = -EINVAL;
1890                 goto out_key_put;
1891         }
1892
1893         len = delim - payload;
1894         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1895                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1896                          len);
1897                 rc = -EINVAL;
1898                 goto out_key_put;
1899         }
1900
1901         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1902         if (!ctx->username) {
1903                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1904                          len);
1905                 rc = -ENOMEM;
1906                 goto out_key_put;
1907         }
1908         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
1909
1910         len = key->datalen - (len + 1);
1911         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
1912                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
1913                 rc = -EINVAL;
1914                 kfree(ctx->username);
1915                 ctx->username = NULL;
1916                 goto out_key_put;
1917         }
1918
1919         ++delim;
1920         ctx->password = kstrndup(delim, len, GFP_KERNEL);
1921         if (!ctx->password) {
1922                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
1923                          len);
1924                 rc = -ENOMEM;
1925                 kfree(ctx->username);
1926                 ctx->username = NULL;
1927                 goto out_key_put;
1928         }
1929
1930         /*
1931          * If we have a domain key then we must set the domainName in the
1932          * for the request.
1933          */
1934         if (is_domain && ses->domainName) {
1935                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
1936                 if (!ctx->domainname) {
1937                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
1938                                  len);
1939                         rc = -ENOMEM;
1940                         kfree(ctx->username);
1941                         ctx->username = NULL;
1942                         kfree_sensitive(ctx->password);
1943                         ctx->password = NULL;
1944                         goto out_key_put;
1945                 }
1946         }
1947
1948 out_key_put:
1949         up_read(&key->sem);
1950         key_put(key);
1951 out_err:
1952         kfree(desc);
1953         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
1954         return rc;
1955 }
1956 #else /* ! CONFIG_KEYS */
1957 static inline int
1958 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
1959                    struct cifs_ses *ses __attribute__((unused)))
1960 {
1961         return -ENOSYS;
1962 }
1963 #endif /* CONFIG_KEYS */
1964
1965 /**
1966  * cifs_get_smb_ses - get a session matching @ctx data from @server
1967  * @server: server to setup the session to
1968  * @ctx: superblock configuration context to use to setup the session
1969  *
1970  * This function assumes it is being called from cifs_mount() where we
1971  * already got a server reference (server refcount +1). See
1972  * cifs_get_tcon() for refcount explanations.
1973  */
1974 struct cifs_ses *
1975 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1976 {
1977         int rc = -ENOMEM;
1978         unsigned int xid;
1979         struct cifs_ses *ses;
1980         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
1981         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
1982
1983         xid = get_xid();
1984
1985         ses = cifs_find_smb_ses(server, ctx);
1986         if (ses) {
1987                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
1988                          ses->status);
1989
1990                 mutex_lock(&ses->session_mutex);
1991                 if (ses->need_reconnect) {
1992                         cifs_dbg(FYI, "Session needs reconnect\n");
1993
1994                         rc = cifs_negotiate_protocol(xid, ses);
1995                         if (rc) {
1996                                 mutex_unlock(&ses->session_mutex);
1997                                 /* problem -- put our ses reference */
1998                                 cifs_put_smb_ses(ses);
1999                                 free_xid(xid);
2000                                 return ERR_PTR(rc);
2001                         }
2002
2003                         rc = cifs_setup_session(xid, ses,
2004                                                 ctx->local_nls);
2005                         if (rc) {
2006                                 mutex_unlock(&ses->session_mutex);
2007                                 /* problem -- put our reference */
2008                                 cifs_put_smb_ses(ses);
2009                                 free_xid(xid);
2010                                 return ERR_PTR(rc);
2011                         }
2012                 }
2013                 mutex_unlock(&ses->session_mutex);
2014
2015                 /* existing SMB ses has a server reference already */
2016                 cifs_put_tcp_session(server, 0);
2017                 free_xid(xid);
2018                 return ses;
2019         }
2020
2021         cifs_dbg(FYI, "Existing smb sess not found\n");
2022         ses = sesInfoAlloc();
2023         if (ses == NULL)
2024                 goto get_ses_fail;
2025
2026         /* new SMB session uses our server ref */
2027         ses->server = server;
2028         if (server->dstaddr.ss_family == AF_INET6)
2029                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2030         else
2031                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2032
2033         if (ctx->username) {
2034                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2035                 if (!ses->user_name)
2036                         goto get_ses_fail;
2037         }
2038
2039         /* ctx->password freed at unmount */
2040         if (ctx->password) {
2041                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2042                 if (!ses->password)
2043                         goto get_ses_fail;
2044         }
2045         if (ctx->domainname) {
2046                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2047                 if (!ses->domainName)
2048                         goto get_ses_fail;
2049         }
2050         if (ctx->workstation_name) {
2051                 ses->workstation_name = kstrdup(ctx->workstation_name,
2052                                                 GFP_KERNEL);
2053                 if (!ses->workstation_name)
2054                         goto get_ses_fail;
2055         }
2056         if (ctx->domainauto)
2057                 ses->domainAuto = ctx->domainauto;
2058         ses->cred_uid = ctx->cred_uid;
2059         ses->linux_uid = ctx->linux_uid;
2060
2061         ses->sectype = ctx->sectype;
2062         ses->sign = ctx->sign;
2063         mutex_lock(&ses->session_mutex);
2064
2065         /* add server as first channel */
2066         spin_lock(&ses->chan_lock);
2067         ses->chans[0].server = server;
2068         ses->chan_count = 1;
2069         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2070         spin_unlock(&ses->chan_lock);
2071
2072         rc = cifs_negotiate_protocol(xid, ses);
2073         if (!rc)
2074                 rc = cifs_setup_session(xid, ses, ctx->local_nls);
2075
2076         /* each channel uses a different signing key */
2077         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2078                sizeof(ses->smb3signingkey));
2079
2080         mutex_unlock(&ses->session_mutex);
2081         if (rc)
2082                 goto get_ses_fail;
2083
2084         /* success, put it on the list and add it as first channel */
2085         spin_lock(&cifs_tcp_ses_lock);
2086         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2087         spin_unlock(&cifs_tcp_ses_lock);
2088
2089         free_xid(xid);
2090
2091         cifs_setup_ipc(ses, ctx);
2092
2093         return ses;
2094
2095 get_ses_fail:
2096         sesInfoFree(ses);
2097         free_xid(xid);
2098         return ERR_PTR(rc);
2099 }
2100
2101 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2102 {
2103         if (tcon->tidStatus == CifsExiting)
2104                 return 0;
2105         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
2106                 return 0;
2107         if (tcon->seal != ctx->seal)
2108                 return 0;
2109         if (tcon->snapshot_time != ctx->snapshot_time)
2110                 return 0;
2111         if (tcon->handle_timeout != ctx->handle_timeout)
2112                 return 0;
2113         if (tcon->no_lease != ctx->no_lease)
2114                 return 0;
2115         if (tcon->nodelete != ctx->nodelete)
2116                 return 0;
2117         return 1;
2118 }
2119
2120 static struct cifs_tcon *
2121 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2122 {
2123         struct list_head *tmp;
2124         struct cifs_tcon *tcon;
2125
2126         spin_lock(&cifs_tcp_ses_lock);
2127         list_for_each(tmp, &ses->tcon_list) {
2128                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
2129
2130                 if (!match_tcon(tcon, ctx))
2131                         continue;
2132                 ++tcon->tc_count;
2133                 spin_unlock(&cifs_tcp_ses_lock);
2134                 return tcon;
2135         }
2136         spin_unlock(&cifs_tcp_ses_lock);
2137         return NULL;
2138 }
2139
2140 void
2141 cifs_put_tcon(struct cifs_tcon *tcon)
2142 {
2143         unsigned int xid;
2144         struct cifs_ses *ses;
2145
2146         /*
2147          * IPC tcon share the lifetime of their session and are
2148          * destroyed in the session put function
2149          */
2150         if (tcon == NULL || tcon->ipc)
2151                 return;
2152
2153         ses = tcon->ses;
2154         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2155         spin_lock(&cifs_tcp_ses_lock);
2156         if (--tcon->tc_count > 0) {
2157                 spin_unlock(&cifs_tcp_ses_lock);
2158                 return;
2159         }
2160
2161         /* tc_count can never go negative */
2162         WARN_ON(tcon->tc_count < 0);
2163
2164         if (tcon->use_witness) {
2165                 int rc;
2166
2167                 rc = cifs_swn_unregister(tcon);
2168                 if (rc < 0) {
2169                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2170                                         __func__, rc);
2171                 }
2172         }
2173
2174         list_del_init(&tcon->tcon_list);
2175         spin_unlock(&cifs_tcp_ses_lock);
2176
2177         xid = get_xid();
2178         if (ses->server->ops->tree_disconnect)
2179                 ses->server->ops->tree_disconnect(xid, tcon);
2180         _free_xid(xid);
2181
2182         cifs_fscache_release_super_cookie(tcon);
2183         tconInfoFree(tcon);
2184         cifs_put_smb_ses(ses);
2185 }
2186
2187 /**
2188  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2189  * @ses: smb session to issue the request on
2190  * @ctx: the superblock configuration context to use for building the
2191  *
2192  * - tcon refcount is the number of mount points using the tcon.
2193  * - ses refcount is the number of tcon using the session.
2194  *
2195  * 1. This function assumes it is being called from cifs_mount() where
2196  *    we already got a session reference (ses refcount +1).
2197  *
2198  * 2. Since we're in the context of adding a mount point, the end
2199  *    result should be either:
2200  *
2201  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2202  *    its session refcount incremented (1 new tcon). This +1 was
2203  *    already done in (1).
2204  *
2205  * b) an existing tcon with refcount+1 (add a mount point to it) and
2206  *    identical ses refcount (no new tcon). Because of (1) we need to
2207  *    decrement the ses refcount.
2208  */
2209 static struct cifs_tcon *
2210 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2211 {
2212         int rc, xid;
2213         struct cifs_tcon *tcon;
2214
2215         tcon = cifs_find_tcon(ses, ctx);
2216         if (tcon) {
2217                 /*
2218                  * tcon has refcount already incremented but we need to
2219                  * decrement extra ses reference gotten by caller (case b)
2220                  */
2221                 cifs_dbg(FYI, "Found match on UNC path\n");
2222                 cifs_put_smb_ses(ses);
2223                 return tcon;
2224         }
2225
2226         if (!ses->server->ops->tree_connect) {
2227                 rc = -ENOSYS;
2228                 goto out_fail;
2229         }
2230
2231         tcon = tconInfoAlloc();
2232         if (tcon == NULL) {
2233                 rc = -ENOMEM;
2234                 goto out_fail;
2235         }
2236
2237         if (ctx->snapshot_time) {
2238                 if (ses->server->vals->protocol_id == 0) {
2239                         cifs_dbg(VFS,
2240                              "Use SMB2 or later for snapshot mount option\n");
2241                         rc = -EOPNOTSUPP;
2242                         goto out_fail;
2243                 } else
2244                         tcon->snapshot_time = ctx->snapshot_time;
2245         }
2246
2247         if (ctx->handle_timeout) {
2248                 if (ses->server->vals->protocol_id == 0) {
2249                         cifs_dbg(VFS,
2250                              "Use SMB2.1 or later for handle timeout option\n");
2251                         rc = -EOPNOTSUPP;
2252                         goto out_fail;
2253                 } else
2254                         tcon->handle_timeout = ctx->handle_timeout;
2255         }
2256
2257         tcon->ses = ses;
2258         if (ctx->password) {
2259                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2260                 if (!tcon->password) {
2261                         rc = -ENOMEM;
2262                         goto out_fail;
2263                 }
2264         }
2265
2266         if (ctx->seal) {
2267                 if (ses->server->vals->protocol_id == 0) {
2268                         cifs_dbg(VFS,
2269                                  "SMB3 or later required for encryption\n");
2270                         rc = -EOPNOTSUPP;
2271                         goto out_fail;
2272                 } else if (tcon->ses->server->capabilities &
2273                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2274                         tcon->seal = true;
2275                 else {
2276                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2277                         rc = -EOPNOTSUPP;
2278                         goto out_fail;
2279                 }
2280         }
2281
2282         if (ctx->linux_ext) {
2283                 if (ses->server->posix_ext_supported) {
2284                         tcon->posix_extensions = true;
2285                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2286                 } else {
2287                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2288                         rc = -EOPNOTSUPP;
2289                         goto out_fail;
2290                 }
2291         }
2292
2293         /*
2294          * BB Do we need to wrap session_mutex around this TCon call and Unix
2295          * SetFS as we do on SessSetup and reconnect?
2296          */
2297         xid = get_xid();
2298         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2299                                             ctx->local_nls);
2300         free_xid(xid);
2301         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2302         if (rc)
2303                 goto out_fail;
2304
2305         tcon->use_persistent = false;
2306         /* check if SMB2 or later, CIFS does not support persistent handles */
2307         if (ctx->persistent) {
2308                 if (ses->server->vals->protocol_id == 0) {
2309                         cifs_dbg(VFS,
2310                              "SMB3 or later required for persistent handles\n");
2311                         rc = -EOPNOTSUPP;
2312                         goto out_fail;
2313                 } else if (ses->server->capabilities &
2314                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2315                         tcon->use_persistent = true;
2316                 else /* persistent handles requested but not supported */ {
2317                         cifs_dbg(VFS,
2318                                 "Persistent handles not supported on share\n");
2319                         rc = -EOPNOTSUPP;
2320                         goto out_fail;
2321                 }
2322         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2323              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2324              && (ctx->nopersistent == false)) {
2325                 cifs_dbg(FYI, "enabling persistent handles\n");
2326                 tcon->use_persistent = true;
2327         } else if (ctx->resilient) {
2328                 if (ses->server->vals->protocol_id == 0) {
2329                         cifs_dbg(VFS,
2330                              "SMB2.1 or later required for resilient handles\n");
2331                         rc = -EOPNOTSUPP;
2332                         goto out_fail;
2333                 }
2334                 tcon->use_resilient = true;
2335         }
2336
2337         tcon->use_witness = false;
2338         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2339                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2340                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2341                                 /*
2342                                  * Set witness in use flag in first place
2343                                  * to retry registration in the echo task
2344                                  */
2345                                 tcon->use_witness = true;
2346                                 /* And try to register immediately */
2347                                 rc = cifs_swn_register(tcon);
2348                                 if (rc < 0) {
2349                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2350                                         goto out_fail;
2351                                 }
2352                         } else {
2353                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2354                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2355                                 rc = -EOPNOTSUPP;
2356                                 goto out_fail;
2357                         }
2358                 } else {
2359                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2360                         rc = -EOPNOTSUPP;
2361                         goto out_fail;
2362                 }
2363         }
2364
2365         /* If the user really knows what they are doing they can override */
2366         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2367                 if (ctx->cache_ro)
2368                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2369                 else if (ctx->cache_rw)
2370                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2371         }
2372
2373         if (ctx->no_lease) {
2374                 if (ses->server->vals->protocol_id == 0) {
2375                         cifs_dbg(VFS,
2376                                 "SMB2 or later required for nolease option\n");
2377                         rc = -EOPNOTSUPP;
2378                         goto out_fail;
2379                 } else
2380                         tcon->no_lease = ctx->no_lease;
2381         }
2382
2383         /*
2384          * We can have only one retry value for a connection to a share so for
2385          * resources mounted more than once to the same server share the last
2386          * value passed in for the retry flag is used.
2387          */
2388         tcon->retry = ctx->retry;
2389         tcon->nocase = ctx->nocase;
2390         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2391                 tcon->nohandlecache = ctx->nohandlecache;
2392         else
2393                 tcon->nohandlecache = true;
2394         tcon->nodelete = ctx->nodelete;
2395         tcon->local_lease = ctx->local_lease;
2396         INIT_LIST_HEAD(&tcon->pending_opens);
2397
2398         spin_lock(&cifs_tcp_ses_lock);
2399         list_add(&tcon->tcon_list, &ses->tcon_list);
2400         spin_unlock(&cifs_tcp_ses_lock);
2401
2402         return tcon;
2403
2404 out_fail:
2405         tconInfoFree(tcon);
2406         return ERR_PTR(rc);
2407 }
2408
2409 void
2410 cifs_put_tlink(struct tcon_link *tlink)
2411 {
2412         if (!tlink || IS_ERR(tlink))
2413                 return;
2414
2415         if (!atomic_dec_and_test(&tlink->tl_count) ||
2416             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2417                 tlink->tl_time = jiffies;
2418                 return;
2419         }
2420
2421         if (!IS_ERR(tlink_tcon(tlink)))
2422                 cifs_put_tcon(tlink_tcon(tlink));
2423         kfree(tlink);
2424         return;
2425 }
2426
2427 static int
2428 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2429 {
2430         struct cifs_sb_info *old = CIFS_SB(sb);
2431         struct cifs_sb_info *new = mnt_data->cifs_sb;
2432         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2433         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2434
2435         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2436                 return 0;
2437
2438         if (old->mnt_cifs_serverino_autodisabled)
2439                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2440
2441         if (oldflags != newflags)
2442                 return 0;
2443
2444         /*
2445          * We want to share sb only if we don't specify an r/wsize or
2446          * specified r/wsize is greater than or equal to existing one.
2447          */
2448         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2449                 return 0;
2450
2451         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2452                 return 0;
2453
2454         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2455             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2456                 return 0;
2457
2458         if (old->ctx->file_mode != new->ctx->file_mode ||
2459             old->ctx->dir_mode != new->ctx->dir_mode)
2460                 return 0;
2461
2462         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2463                 return 0;
2464
2465         if (old->ctx->acregmax != new->ctx->acregmax)
2466                 return 0;
2467         if (old->ctx->acdirmax != new->ctx->acdirmax)
2468                 return 0;
2469
2470         return 1;
2471 }
2472
2473 static int
2474 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2475 {
2476         struct cifs_sb_info *old = CIFS_SB(sb);
2477         struct cifs_sb_info *new = mnt_data->cifs_sb;
2478         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2479                 old->prepath;
2480         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2481                 new->prepath;
2482
2483         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2484                 return 1;
2485         else if (!old_set && !new_set)
2486                 return 1;
2487
2488         return 0;
2489 }
2490
2491 int
2492 cifs_match_super(struct super_block *sb, void *data)
2493 {
2494         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2495         struct smb3_fs_context *ctx;
2496         struct cifs_sb_info *cifs_sb;
2497         struct TCP_Server_Info *tcp_srv;
2498         struct cifs_ses *ses;
2499         struct cifs_tcon *tcon;
2500         struct tcon_link *tlink;
2501         int rc = 0;
2502
2503         spin_lock(&cifs_tcp_ses_lock);
2504         cifs_sb = CIFS_SB(sb);
2505         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2506         if (tlink == NULL) {
2507                 /* can not match superblock if tlink were ever null */
2508                 spin_unlock(&cifs_tcp_ses_lock);
2509                 return 0;
2510         }
2511         tcon = tlink_tcon(tlink);
2512         ses = tcon->ses;
2513         tcp_srv = ses->server;
2514
2515         ctx = mnt_data->ctx;
2516
2517         if (!match_server(tcp_srv, ctx) ||
2518             !match_session(ses, ctx) ||
2519             !match_tcon(tcon, ctx) ||
2520             !match_prepath(sb, mnt_data)) {
2521                 rc = 0;
2522                 goto out;
2523         }
2524
2525         rc = compare_mount_options(sb, mnt_data);
2526 out:
2527         spin_unlock(&cifs_tcp_ses_lock);
2528         cifs_put_tlink(tlink);
2529         return rc;
2530 }
2531
2532 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2533 static struct lock_class_key cifs_key[2];
2534 static struct lock_class_key cifs_slock_key[2];
2535
2536 static inline void
2537 cifs_reclassify_socket4(struct socket *sock)
2538 {
2539         struct sock *sk = sock->sk;
2540         BUG_ON(!sock_allow_reclassification(sk));
2541         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2542                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2543 }
2544
2545 static inline void
2546 cifs_reclassify_socket6(struct socket *sock)
2547 {
2548         struct sock *sk = sock->sk;
2549         BUG_ON(!sock_allow_reclassification(sk));
2550         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2551                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2552 }
2553 #else
2554 static inline void
2555 cifs_reclassify_socket4(struct socket *sock)
2556 {
2557 }
2558
2559 static inline void
2560 cifs_reclassify_socket6(struct socket *sock)
2561 {
2562 }
2563 #endif
2564
2565 /* See RFC1001 section 14 on representation of Netbios names */
2566 static void rfc1002mangle(char *target, char *source, unsigned int length)
2567 {
2568         unsigned int i, j;
2569
2570         for (i = 0, j = 0; i < (length); i++) {
2571                 /* mask a nibble at a time and encode */
2572                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2573                 target[j+1] = 'A' + (0x0F & source[i]);
2574                 j += 2;
2575         }
2576
2577 }
2578
2579 static int
2580 bind_socket(struct TCP_Server_Info *server)
2581 {
2582         int rc = 0;
2583         if (server->srcaddr.ss_family != AF_UNSPEC) {
2584                 /* Bind to the specified local IP address */
2585                 struct socket *socket = server->ssocket;
2586                 rc = socket->ops->bind(socket,
2587                                        (struct sockaddr *) &server->srcaddr,
2588                                        sizeof(server->srcaddr));
2589                 if (rc < 0) {
2590                         struct sockaddr_in *saddr4;
2591                         struct sockaddr_in6 *saddr6;
2592                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2593                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2594                         if (saddr6->sin6_family == AF_INET6)
2595                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2596                                          &saddr6->sin6_addr, rc);
2597                         else
2598                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2599                                          &saddr4->sin_addr.s_addr, rc);
2600                 }
2601         }
2602         return rc;
2603 }
2604
2605 static int
2606 ip_rfc1001_connect(struct TCP_Server_Info *server)
2607 {
2608         int rc = 0;
2609         /*
2610          * some servers require RFC1001 sessinit before sending
2611          * negprot - BB check reconnection in case where second
2612          * sessinit is sent but no second negprot
2613          */
2614         struct rfc1002_session_packet *ses_init_buf;
2615         struct smb_hdr *smb_buf;
2616         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2617                                GFP_KERNEL);
2618         if (ses_init_buf) {
2619                 ses_init_buf->trailer.session_req.called_len = 32;
2620
2621                 if (server->server_RFC1001_name[0] != 0)
2622                         rfc1002mangle(ses_init_buf->trailer.
2623                                       session_req.called_name,
2624                                       server->server_RFC1001_name,
2625                                       RFC1001_NAME_LEN_WITH_NULL);
2626                 else
2627                         rfc1002mangle(ses_init_buf->trailer.
2628                                       session_req.called_name,
2629                                       DEFAULT_CIFS_CALLED_NAME,
2630                                       RFC1001_NAME_LEN_WITH_NULL);
2631
2632                 ses_init_buf->trailer.session_req.calling_len = 32;
2633
2634                 /*
2635                  * calling name ends in null (byte 16) from old smb
2636                  * convention.
2637                  */
2638                 if (server->workstation_RFC1001_name[0] != 0)
2639                         rfc1002mangle(ses_init_buf->trailer.
2640                                       session_req.calling_name,
2641                                       server->workstation_RFC1001_name,
2642                                       RFC1001_NAME_LEN_WITH_NULL);
2643                 else
2644                         rfc1002mangle(ses_init_buf->trailer.
2645                                       session_req.calling_name,
2646                                       "LINUX_CIFS_CLNT",
2647                                       RFC1001_NAME_LEN_WITH_NULL);
2648
2649                 ses_init_buf->trailer.session_req.scope1 = 0;
2650                 ses_init_buf->trailer.session_req.scope2 = 0;
2651                 smb_buf = (struct smb_hdr *)ses_init_buf;
2652
2653                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2654                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2655                 rc = smb_send(server, smb_buf, 0x44);
2656                 kfree(ses_init_buf);
2657                 /*
2658                  * RFC1001 layer in at least one server
2659                  * requires very short break before negprot
2660                  * presumably because not expecting negprot
2661                  * to follow so fast.  This is a simple
2662                  * solution that works without
2663                  * complicating the code and causes no
2664                  * significant slowing down on mount
2665                  * for everyone else
2666                  */
2667                 usleep_range(1000, 2000);
2668         }
2669         /*
2670          * else the negprot may still work without this
2671          * even though malloc failed
2672          */
2673
2674         return rc;
2675 }
2676
2677 static int
2678 generic_ip_connect(struct TCP_Server_Info *server)
2679 {
2680         int rc = 0;
2681         __be16 sport;
2682         int slen, sfamily;
2683         struct socket *socket = server->ssocket;
2684         struct sockaddr *saddr;
2685
2686         saddr = (struct sockaddr *) &server->dstaddr;
2687
2688         if (server->dstaddr.ss_family == AF_INET6) {
2689                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2690
2691                 sport = ipv6->sin6_port;
2692                 slen = sizeof(struct sockaddr_in6);
2693                 sfamily = AF_INET6;
2694                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2695                                 ntohs(sport));
2696         } else {
2697                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2698
2699                 sport = ipv4->sin_port;
2700                 slen = sizeof(struct sockaddr_in);
2701                 sfamily = AF_INET;
2702                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2703                                 ntohs(sport));
2704         }
2705
2706         if (socket == NULL) {
2707                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2708                                    IPPROTO_TCP, &socket, 1);
2709                 if (rc < 0) {
2710                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2711                         server->ssocket = NULL;
2712                         return rc;
2713                 }
2714
2715                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2716                 cifs_dbg(FYI, "Socket created\n");
2717                 server->ssocket = socket;
2718                 socket->sk->sk_allocation = GFP_NOFS;
2719                 if (sfamily == AF_INET6)
2720                         cifs_reclassify_socket6(socket);
2721                 else
2722                         cifs_reclassify_socket4(socket);
2723         }
2724
2725         rc = bind_socket(server);
2726         if (rc < 0)
2727                 return rc;
2728
2729         /*
2730          * Eventually check for other socket options to change from
2731          * the default. sock_setsockopt not used because it expects
2732          * user space buffer
2733          */
2734         socket->sk->sk_rcvtimeo = 7 * HZ;
2735         socket->sk->sk_sndtimeo = 5 * HZ;
2736
2737         /* make the bufsizes depend on wsize/rsize and max requests */
2738         if (server->noautotune) {
2739                 if (socket->sk->sk_sndbuf < (200 * 1024))
2740                         socket->sk->sk_sndbuf = 200 * 1024;
2741                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2742                         socket->sk->sk_rcvbuf = 140 * 1024;
2743         }
2744
2745         if (server->tcp_nodelay)
2746                 tcp_sock_set_nodelay(socket->sk);
2747
2748         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2749                  socket->sk->sk_sndbuf,
2750                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2751
2752         rc = socket->ops->connect(socket, saddr, slen,
2753                                   server->noblockcnt ? O_NONBLOCK : 0);
2754         /*
2755          * When mounting SMB root file systems, we do not want to block in
2756          * connect. Otherwise bail out and then let cifs_reconnect() perform
2757          * reconnect failover - if possible.
2758          */
2759         if (server->noblockcnt && rc == -EINPROGRESS)
2760                 rc = 0;
2761         if (rc < 0) {
2762                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2763                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2764                 sock_release(socket);
2765                 server->ssocket = NULL;
2766                 return rc;
2767         }
2768         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2769         if (sport == htons(RFC1001_PORT))
2770                 rc = ip_rfc1001_connect(server);
2771
2772         return rc;
2773 }
2774
2775 static int
2776 ip_connect(struct TCP_Server_Info *server)
2777 {
2778         __be16 *sport;
2779         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2780         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2781
2782         if (server->dstaddr.ss_family == AF_INET6)
2783                 sport = &addr6->sin6_port;
2784         else
2785                 sport = &addr->sin_port;
2786
2787         if (*sport == 0) {
2788                 int rc;
2789
2790                 /* try with 445 port at first */
2791                 *sport = htons(CIFS_PORT);
2792
2793                 rc = generic_ip_connect(server);
2794                 if (rc >= 0)
2795                         return rc;
2796
2797                 /* if it failed, try with 139 port */
2798                 *sport = htons(RFC1001_PORT);
2799         }
2800
2801         return generic_ip_connect(server);
2802 }
2803
2804 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2805                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2806 {
2807         /*
2808          * If we are reconnecting then should we check to see if
2809          * any requested capabilities changed locally e.g. via
2810          * remount but we can not do much about it here
2811          * if they have (even if we could detect it by the following)
2812          * Perhaps we could add a backpointer to array of sb from tcon
2813          * or if we change to make all sb to same share the same
2814          * sb as NFS - then we only have one backpointer to sb.
2815          * What if we wanted to mount the server share twice once with
2816          * and once without posixacls or posix paths?
2817          */
2818         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2819
2820         if (ctx && ctx->no_linux_ext) {
2821                 tcon->fsUnixInfo.Capability = 0;
2822                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2823                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2824                 return;
2825         } else if (ctx)
2826                 tcon->unix_ext = 1; /* Unix Extensions supported */
2827
2828         if (!tcon->unix_ext) {
2829                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2830                 return;
2831         }
2832
2833         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2834                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2835                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2836                 /*
2837                  * check for reconnect case in which we do not
2838                  * want to change the mount behavior if we can avoid it
2839                  */
2840                 if (ctx == NULL) {
2841                         /*
2842                          * turn off POSIX ACL and PATHNAMES if not set
2843                          * originally at mount time
2844                          */
2845                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2846                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2847                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2848                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2849                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2850                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2851                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2852                                 cifs_dbg(VFS, "possible reconnect error\n");
2853                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2854                         }
2855                 }
2856
2857                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2858                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2859
2860                 cap &= CIFS_UNIX_CAP_MASK;
2861                 if (ctx && ctx->no_psx_acl)
2862                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2863                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2864                         cifs_dbg(FYI, "negotiated posix acl support\n");
2865                         if (cifs_sb)
2866                                 cifs_sb->mnt_cifs_flags |=
2867                                         CIFS_MOUNT_POSIXACL;
2868                 }
2869
2870                 if (ctx && ctx->posix_paths == 0)
2871                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2872                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2873                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2874                         if (cifs_sb)
2875                                 cifs_sb->mnt_cifs_flags |=
2876                                         CIFS_MOUNT_POSIX_PATHS;
2877                 }
2878
2879                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
2880 #ifdef CONFIG_CIFS_DEBUG2
2881                 if (cap & CIFS_UNIX_FCNTL_CAP)
2882                         cifs_dbg(FYI, "FCNTL cap\n");
2883                 if (cap & CIFS_UNIX_EXTATTR_CAP)
2884                         cifs_dbg(FYI, "EXTATTR cap\n");
2885                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2886                         cifs_dbg(FYI, "POSIX path cap\n");
2887                 if (cap & CIFS_UNIX_XATTR_CAP)
2888                         cifs_dbg(FYI, "XATTR cap\n");
2889                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
2890                         cifs_dbg(FYI, "POSIX ACL cap\n");
2891                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
2892                         cifs_dbg(FYI, "very large read cap\n");
2893                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
2894                         cifs_dbg(FYI, "very large write cap\n");
2895                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
2896                         cifs_dbg(FYI, "transport encryption cap\n");
2897                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2898                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
2899 #endif /* CIFS_DEBUG2 */
2900                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
2901                         if (ctx == NULL)
2902                                 cifs_dbg(FYI, "resetting capabilities failed\n");
2903                         else
2904                                 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");
2905
2906                 }
2907         }
2908 }
2909
2910 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
2911 {
2912         struct smb3_fs_context *ctx = cifs_sb->ctx;
2913
2914         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
2915
2916         spin_lock_init(&cifs_sb->tlink_tree_lock);
2917         cifs_sb->tlink_tree = RB_ROOT;
2918
2919         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
2920                  ctx->file_mode, ctx->dir_mode);
2921
2922         /* this is needed for ASCII cp to Unicode converts */
2923         if (ctx->iocharset == NULL) {
2924                 /* load_nls_default cannot return null */
2925                 cifs_sb->local_nls = load_nls_default();
2926         } else {
2927                 cifs_sb->local_nls = load_nls(ctx->iocharset);
2928                 if (cifs_sb->local_nls == NULL) {
2929                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
2930                                  ctx->iocharset);
2931                         return -ELIBACC;
2932                 }
2933         }
2934         ctx->local_nls = cifs_sb->local_nls;
2935
2936         smb3_update_mnt_flags(cifs_sb);
2937
2938         if (ctx->direct_io)
2939                 cifs_dbg(FYI, "mounting share using direct i/o\n");
2940         if (ctx->cache_ro) {
2941                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
2942                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
2943         } else if (ctx->cache_rw) {
2944                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
2945                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
2946                                             CIFS_MOUNT_RW_CACHE);
2947         }
2948
2949         if ((ctx->cifs_acl) && (ctx->dynperm))
2950                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
2951
2952         if (ctx->prepath) {
2953                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
2954                 if (cifs_sb->prepath == NULL)
2955                         return -ENOMEM;
2956                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
2957         }
2958
2959         return 0;
2960 }
2961
2962 /* Release all succeed connections */
2963 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
2964 {
2965         int rc = 0;
2966
2967         if (mnt_ctx->tcon)
2968                 cifs_put_tcon(mnt_ctx->tcon);
2969         else if (mnt_ctx->ses)
2970                 cifs_put_smb_ses(mnt_ctx->ses);
2971         else if (mnt_ctx->server)
2972                 cifs_put_tcp_session(mnt_ctx->server, 0);
2973         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
2974         free_xid(mnt_ctx->xid);
2975 }
2976
2977 /* Get connections for tcp, ses and tcon */
2978 static int mount_get_conns(struct mount_ctx *mnt_ctx)
2979 {
2980         int rc = 0;
2981         struct TCP_Server_Info *server = NULL;
2982         struct cifs_ses *ses = NULL;
2983         struct cifs_tcon *tcon = NULL;
2984         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
2985         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
2986         unsigned int xid;
2987
2988         xid = get_xid();
2989
2990         /* get a reference to a tcp session */
2991         server = cifs_get_tcp_session(ctx, NULL);
2992         if (IS_ERR(server)) {
2993                 rc = PTR_ERR(server);
2994                 server = NULL;
2995                 goto out;
2996         }
2997
2998         /* get a reference to a SMB session */
2999         ses = cifs_get_smb_ses(server, ctx);
3000         if (IS_ERR(ses)) {
3001                 rc = PTR_ERR(ses);
3002                 ses = NULL;
3003                 goto out;
3004         }
3005
3006         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3007                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3008                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3009                 rc = -EOPNOTSUPP;
3010                 goto out;
3011         }
3012
3013         /* search for existing tcon to this server share */
3014         tcon = cifs_get_tcon(ses, ctx);
3015         if (IS_ERR(tcon)) {
3016                 rc = PTR_ERR(tcon);
3017                 tcon = NULL;
3018                 goto out;
3019         }
3020
3021         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3022         if (tcon->posix_extensions)
3023                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3024
3025         /* tell server which Unix caps we support */
3026         if (cap_unix(tcon->ses)) {
3027                 /*
3028                  * reset of caps checks mount to see if unix extensions disabled
3029                  * for just this mount.
3030                  */
3031                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3032                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3033                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3034                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3035                         rc = -EACCES;
3036                         goto out;
3037                 }
3038         } else
3039                 tcon->unix_ext = 0; /* server does not support them */
3040
3041         /* do not care if a following call succeed - informational */
3042         if (!tcon->pipe && server->ops->qfs_tcon) {
3043                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3044                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3045                         if (tcon->fsDevInfo.DeviceCharacteristics &
3046                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3047                                 cifs_dbg(VFS, "mounted to read only share\n");
3048                         else if ((cifs_sb->mnt_cifs_flags &
3049                                   CIFS_MOUNT_RW_CACHE) == 0)
3050                                 cifs_dbg(VFS, "read only mount of RW share\n");
3051                         /* no need to log a RW mount of a typical RW share */
3052                 }
3053         }
3054
3055         /*
3056          * Clamp the rsize/wsize mount arguments if they are too big for the server
3057          * and set the rsize/wsize to the negotiated values if not passed in by
3058          * the user on mount
3059          */
3060         if ((cifs_sb->ctx->wsize == 0) ||
3061             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3062                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3063         if ((cifs_sb->ctx->rsize == 0) ||
3064             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3065                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3066
3067         /*
3068          * The cookie is initialized from volume info returned above.
3069          * Inside cifs_fscache_get_super_cookie it checks
3070          * that we do not get super cookie twice.
3071          */
3072         cifs_fscache_get_super_cookie(tcon);
3073
3074 out:
3075         mnt_ctx->server = server;
3076         mnt_ctx->ses = ses;
3077         mnt_ctx->tcon = tcon;
3078         mnt_ctx->xid = xid;
3079
3080         return rc;
3081 }
3082
3083 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3084                              struct cifs_tcon *tcon)
3085 {
3086         struct tcon_link *tlink;
3087
3088         /* hang the tcon off of the superblock */
3089         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3090         if (tlink == NULL)
3091                 return -ENOMEM;
3092
3093         tlink->tl_uid = ses->linux_uid;
3094         tlink->tl_tcon = tcon;
3095         tlink->tl_time = jiffies;
3096         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3097         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3098
3099         cifs_sb->master_tlink = tlink;
3100         spin_lock(&cifs_sb->tlink_tree_lock);
3101         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3102         spin_unlock(&cifs_sb->tlink_tree_lock);
3103
3104         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3105                                 TLINK_IDLE_EXPIRE);
3106         return 0;
3107 }
3108
3109 #ifdef CONFIG_CIFS_DFS_UPCALL
3110 /* Get unique dfs connections */
3111 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3112 {
3113         int rc;
3114
3115         mnt_ctx->fs_ctx->nosharesock = true;
3116         rc = mount_get_conns(mnt_ctx);
3117         if (mnt_ctx->server) {
3118                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3119                 spin_lock(&cifs_tcp_ses_lock);
3120                 mnt_ctx->server->is_dfs_conn = true;
3121                 spin_unlock(&cifs_tcp_ses_lock);
3122         }
3123         return rc;
3124 }
3125
3126 /*
3127  * cifs_build_path_to_root returns full path to root when we do not have an
3128  * existing connection (tcon)
3129  */
3130 static char *
3131 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3132                        const struct cifs_sb_info *cifs_sb, bool useppath)
3133 {
3134         char *full_path, *pos;
3135         unsigned int pplen = useppath && ctx->prepath ?
3136                 strlen(ctx->prepath) + 1 : 0;
3137         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3138
3139         if (unc_len > MAX_TREE_SIZE)
3140                 return ERR_PTR(-EINVAL);
3141
3142         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3143         if (full_path == NULL)
3144                 return ERR_PTR(-ENOMEM);
3145
3146         memcpy(full_path, ctx->UNC, unc_len);
3147         pos = full_path + unc_len;
3148
3149         if (pplen) {
3150                 *pos = CIFS_DIR_SEP(cifs_sb);
3151                 memcpy(pos + 1, ctx->prepath, pplen);
3152                 pos += pplen;
3153         }
3154
3155         *pos = '\0'; /* add trailing null */
3156         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3157         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3158         return full_path;
3159 }
3160
3161 /*
3162  * expand_dfs_referral - Update cifs_sb from dfs referral path
3163  *
3164  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3165  * submount.  Otherwise it will be left untouched.
3166  */
3167 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3168                                struct dfs_info3_param *referral)
3169 {
3170         int rc;
3171         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3172         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3173         char *fake_devname = NULL, *mdata = NULL;
3174
3175         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3176                                            &fake_devname);
3177         if (IS_ERR(mdata)) {
3178                 rc = PTR_ERR(mdata);
3179                 mdata = NULL;
3180         } else {
3181                 /*
3182                  * We can not clear out the whole structure since we no longer have an explicit
3183                  * function to parse a mount-string. Instead we need to clear out the individual
3184                  * fields that are no longer valid.
3185                  */
3186                 kfree(ctx->prepath);
3187                 ctx->prepath = NULL;
3188                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3189         }
3190         kfree(fake_devname);
3191         kfree(cifs_sb->ctx->mount_options);
3192         cifs_sb->ctx->mount_options = mdata;
3193
3194         return rc;
3195 }
3196 #endif
3197
3198 /* TODO: all callers to this are broken. We are not parsing mount_options here
3199  * we should pass a clone of the original context?
3200  */
3201 int
3202 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3203 {
3204         int rc;
3205
3206         if (devname) {
3207                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3208                 rc = smb3_parse_devname(devname, ctx);
3209                 if (rc) {
3210                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3211                         return rc;
3212                 }
3213         }
3214
3215         if (mntopts) {
3216                 char *ip;
3217
3218                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3219                 if (rc) {
3220                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3221                         return rc;
3222                 }
3223
3224                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3225                 kfree(ip);
3226                 if (!rc) {
3227                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3228                         return -EINVAL;
3229                 }
3230         }
3231
3232         if (ctx->nullauth) {
3233                 cifs_dbg(FYI, "Anonymous login\n");
3234                 kfree(ctx->username);
3235                 ctx->username = NULL;
3236         } else if (ctx->username) {
3237                 /* BB fixme parse for domain name here */
3238                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3239         } else {
3240                 cifs_dbg(VFS, "No username specified\n");
3241         /* In userspace mount helper we can get user name from alternate
3242            locations such as env variables and files on disk */
3243                 return -EINVAL;
3244         }
3245
3246         return 0;
3247 }
3248
3249 static int
3250 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3251                                         unsigned int xid,
3252                                         struct cifs_tcon *tcon,
3253                                         struct cifs_sb_info *cifs_sb,
3254                                         char *full_path,
3255                                         int added_treename)
3256 {
3257         int rc;
3258         char *s;
3259         char sep, tmp;
3260         int skip = added_treename ? 1 : 0;
3261
3262         sep = CIFS_DIR_SEP(cifs_sb);
3263         s = full_path;
3264
3265         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3266         while (rc == 0) {
3267                 /* skip separators */
3268                 while (*s == sep)
3269                         s++;
3270                 if (!*s)
3271                         break;
3272                 /* next separator */
3273                 while (*s && *s != sep)
3274                         s++;
3275                 /*
3276                  * if the treename is added, we then have to skip the first
3277                  * part within the separators
3278                  */
3279                 if (skip) {
3280                         skip = 0;
3281                         continue;
3282                 }
3283                 /*
3284                  * temporarily null-terminate the path at the end of
3285                  * the current component
3286                  */
3287                 tmp = *s;
3288                 *s = 0;
3289                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3290                                                      full_path);
3291                 *s = tmp;
3292         }
3293         return rc;
3294 }
3295
3296 /*
3297  * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
3298  * otherwise 0.
3299  */
3300 static int is_path_remote(struct mount_ctx *mnt_ctx)
3301 {
3302         int rc;
3303         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3304         struct TCP_Server_Info *server = mnt_ctx->server;
3305         unsigned int xid = mnt_ctx->xid;
3306         struct cifs_tcon *tcon = mnt_ctx->tcon;
3307         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3308         char *full_path;
3309
3310         if (!server->ops->is_path_accessible)
3311                 return -EOPNOTSUPP;
3312
3313         /*
3314          * cifs_build_path_to_root works only when we have a valid tcon
3315          */
3316         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3317                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3318         if (full_path == NULL)
3319                 return -ENOMEM;
3320
3321         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3322
3323         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3324                                              full_path);
3325         if (rc != 0 && rc != -EREMOTE) {
3326                 kfree(full_path);
3327                 return rc;
3328         }
3329
3330         if (rc != -EREMOTE) {
3331                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3332                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3333                 if (rc != 0) {
3334                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3335                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3336                         rc = 0;
3337                 }
3338         }
3339
3340         kfree(full_path);
3341         return rc;
3342 }
3343
3344 #ifdef CONFIG_CIFS_DFS_UPCALL
3345 static void set_root_ses(struct mount_ctx *mnt_ctx)
3346 {
3347         if (mnt_ctx->ses) {
3348                 spin_lock(&cifs_tcp_ses_lock);
3349                 mnt_ctx->ses->ses_count++;
3350                 spin_unlock(&cifs_tcp_ses_lock);
3351                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3352         }
3353         mnt_ctx->root_ses = mnt_ctx->ses;
3354 }
3355
3356 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3357 {
3358         int rc;
3359         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3360         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3361
3362         *isdfs = true;
3363
3364         rc = mount_get_conns(mnt_ctx);
3365         /*
3366          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3367          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3368          *
3369          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3370          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3371          */
3372         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3373             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3374                            ctx->UNC + 1, NULL, root_tl)) {
3375                 if (rc)
3376                         return rc;
3377                 /* Check if it is fully accessible and then mount it */
3378                 rc = is_path_remote(mnt_ctx);
3379                 if (!rc)
3380                         *isdfs = false;
3381                 else if (rc != -EREMOTE)
3382                         return rc;
3383         }
3384         return 0;
3385 }
3386
3387 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3388                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3389 {
3390         int rc;
3391         struct dfs_info3_param ref = {};
3392         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3393         char *oldmnt = cifs_sb->ctx->mount_options;
3394
3395         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3396         if (rc)
3397                 goto out;
3398
3399         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3400         if (rc)
3401                 goto out;
3402
3403         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3404         if (oldmnt != cifs_sb->ctx->mount_options) {
3405                 mount_put_conns(mnt_ctx);
3406                 rc = mount_get_dfs_conns(mnt_ctx);
3407         }
3408         if (!rc) {
3409                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3410                         set_root_ses(mnt_ctx);
3411                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3412                                               cifs_remap(cifs_sb), ref_path, tit);
3413         }
3414
3415 out:
3416         free_dfs_info_param(&ref);
3417         return rc;
3418 }
3419
3420 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3421 {
3422         int rc;
3423         char *full_path;
3424         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3425         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3426         struct dfs_cache_tgt_iterator *tit;
3427
3428         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3429          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3430          * now on.
3431          */
3432         mount_put_conns(mnt_ctx);
3433         mount_get_dfs_conns(mnt_ctx);
3434         set_root_ses(mnt_ctx);
3435
3436         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3437         if (IS_ERR(full_path))
3438                 return PTR_ERR(full_path);
3439
3440         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3441                                                             cifs_remap(cifs_sb));
3442         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3443                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3444                 mnt_ctx->origin_fullpath = NULL;
3445                 goto out;
3446         }
3447
3448         /* Try all dfs root targets */
3449         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3450              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3451                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3452                 if (!rc) {
3453                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3454                         if (!mnt_ctx->leaf_fullpath)
3455                                 rc = -ENOMEM;
3456                         break;
3457                 }
3458         }
3459
3460 out:
3461         kfree(full_path);
3462         return rc;
3463 }
3464
3465 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3466 {
3467         int rc;
3468         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3469         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3470         char *full_path;
3471         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3472         struct dfs_cache_tgt_iterator *tit;
3473
3474         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3475         if (IS_ERR(full_path))
3476                 return PTR_ERR(full_path);
3477
3478         kfree(mnt_ctx->leaf_fullpath);
3479         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3480                                                           cifs_remap(cifs_sb));
3481         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3482                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3483                 mnt_ctx->leaf_fullpath = NULL;
3484                 goto out;
3485         }
3486
3487         /* Get referral from dfs link */
3488         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3489                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3490         if (rc)
3491                 goto out;
3492
3493         /* Try all dfs link targets */
3494         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3495              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3496                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3497                 if (!rc) {
3498                         rc = is_path_remote(mnt_ctx);
3499                         break;
3500                 }
3501         }
3502
3503 out:
3504         kfree(full_path);
3505         dfs_cache_free_tgts(&tl);
3506         return rc;
3507 }
3508
3509 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3510 {
3511         int rc;
3512         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3513         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3514         char *full_path;
3515         int num_links = 0;
3516
3517         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3518         if (IS_ERR(full_path))
3519                 return PTR_ERR(full_path);
3520
3521         kfree(mnt_ctx->origin_fullpath);
3522         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3523                                                             cifs_remap(cifs_sb));
3524         kfree(full_path);
3525
3526         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3527                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3528                 mnt_ctx->origin_fullpath = NULL;
3529                 return rc;
3530         }
3531
3532         do {
3533                 rc = __follow_dfs_link(mnt_ctx);
3534                 if (!rc || rc != -EREMOTE)
3535                         break;
3536         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3537
3538         return rc;
3539 }
3540
3541 /* Set up DFS referral paths for failover */
3542 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3543 {
3544         struct TCP_Server_Info *server = mnt_ctx->server;
3545
3546         server->origin_fullpath = mnt_ctx->origin_fullpath;
3547         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3548         server->current_fullpath = mnt_ctx->leaf_fullpath;
3549         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3550 }
3551
3552 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3553 {
3554         int rc;
3555         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3556         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3557         bool isdfs;
3558
3559         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3560         if (rc)
3561                 goto error;
3562         if (!isdfs)
3563                 goto out;
3564
3565         uuid_gen(&mnt_ctx.mount_id);
3566         rc = connect_dfs_root(&mnt_ctx, &tl);
3567         dfs_cache_free_tgts(&tl);
3568
3569         if (rc)
3570                 goto error;
3571
3572         rc = is_path_remote(&mnt_ctx);
3573         if (rc == -EREMOTE)
3574                 rc = follow_dfs_link(&mnt_ctx);
3575         if (rc)
3576                 goto error;
3577
3578         setup_server_referral_paths(&mnt_ctx);
3579         /*
3580          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3581          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3582          */
3583         cifs_autodisable_serverino(cifs_sb);
3584         /*
3585          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3586          * that have different prefix paths.
3587          */
3588         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3589         kfree(cifs_sb->prepath);
3590         cifs_sb->prepath = ctx->prepath;
3591         ctx->prepath = NULL;
3592         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3593
3594 out:
3595         free_xid(mnt_ctx.xid);
3596         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3597         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3598
3599 error:
3600         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3601         kfree(mnt_ctx.origin_fullpath);
3602         kfree(mnt_ctx.leaf_fullpath);
3603         mount_put_conns(&mnt_ctx);
3604         return rc;
3605 }
3606 #else
3607 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3608 {
3609         int rc = 0;
3610         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3611
3612         rc = mount_get_conns(&mnt_ctx);
3613         if (rc)
3614                 goto error;
3615
3616         if (mnt_ctx.tcon) {
3617                 rc = is_path_remote(&mnt_ctx);
3618                 if (rc == -EREMOTE)
3619                         rc = -EOPNOTSUPP;
3620                 if (rc)
3621                         goto error;
3622         }
3623
3624         free_xid(mnt_ctx.xid);
3625         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3626
3627 error:
3628         mount_put_conns(&mnt_ctx);
3629         return rc;
3630 }
3631 #endif
3632
3633 /*
3634  * Issue a TREE_CONNECT request.
3635  */
3636 int
3637 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3638          const char *tree, struct cifs_tcon *tcon,
3639          const struct nls_table *nls_codepage)
3640 {
3641         struct smb_hdr *smb_buffer;
3642         struct smb_hdr *smb_buffer_response;
3643         TCONX_REQ *pSMB;
3644         TCONX_RSP *pSMBr;
3645         unsigned char *bcc_ptr;
3646         int rc = 0;
3647         int length;
3648         __u16 bytes_left, count;
3649
3650         if (ses == NULL)
3651                 return -EIO;
3652
3653         smb_buffer = cifs_buf_get();
3654         if (smb_buffer == NULL)
3655                 return -ENOMEM;
3656
3657         smb_buffer_response = smb_buffer;
3658
3659         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3660                         NULL /*no tid */ , 4 /*wct */ );
3661
3662         smb_buffer->Mid = get_next_mid(ses->server);
3663         smb_buffer->Uid = ses->Suid;
3664         pSMB = (TCONX_REQ *) smb_buffer;
3665         pSMBr = (TCONX_RSP *) smb_buffer_response;
3666
3667         pSMB->AndXCommand = 0xFF;
3668         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3669         bcc_ptr = &pSMB->Password[0];
3670         if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
3671                 pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3672                 *bcc_ptr = 0; /* password is null byte */
3673                 bcc_ptr++;              /* skip password */
3674                 /* already aligned so no need to do it below */
3675         }
3676
3677         if (ses->server->sign)
3678                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3679
3680         if (ses->capabilities & CAP_STATUS32) {
3681                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3682         }
3683         if (ses->capabilities & CAP_DFS) {
3684                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3685         }
3686         if (ses->capabilities & CAP_UNICODE) {
3687                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3688                 length =
3689                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3690                         6 /* max utf8 char length in bytes */ *
3691                         (/* server len*/ + 256 /* share len */), nls_codepage);
3692                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3693                 bcc_ptr += 2;   /* skip trailing null */
3694         } else {                /* ASCII */
3695                 strcpy(bcc_ptr, tree);
3696                 bcc_ptr += strlen(tree) + 1;
3697         }
3698         strcpy(bcc_ptr, "?????");
3699         bcc_ptr += strlen("?????");
3700         bcc_ptr += 1;
3701         count = bcc_ptr - &pSMB->Password[0];
3702         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3703         pSMB->ByteCount = cpu_to_le16(count);
3704
3705         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3706                          0);
3707
3708         /* above now done in SendReceive */
3709         if (rc == 0) {
3710                 bool is_unicode;
3711
3712                 tcon->tidStatus = CifsGood;
3713                 tcon->need_reconnect = false;
3714                 tcon->tid = smb_buffer_response->Tid;
3715                 bcc_ptr = pByteArea(smb_buffer_response);
3716                 bytes_left = get_bcc(smb_buffer_response);
3717                 length = strnlen(bcc_ptr, bytes_left - 2);
3718                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3719                         is_unicode = true;
3720                 else
3721                         is_unicode = false;
3722
3723
3724                 /* skip service field (NB: this field is always ASCII) */
3725                 if (length == 3) {
3726                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3727                             (bcc_ptr[2] == 'C')) {
3728                                 cifs_dbg(FYI, "IPC connection\n");
3729                                 tcon->ipc = true;
3730                                 tcon->pipe = true;
3731                         }
3732                 } else if (length == 2) {
3733                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3734                                 /* the most common case */
3735                                 cifs_dbg(FYI, "disk share connection\n");
3736                         }
3737                 }
3738                 bcc_ptr += length + 1;
3739                 bytes_left -= (length + 1);
3740                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3741
3742                 /* mostly informational -- no need to fail on error here */
3743                 kfree(tcon->nativeFileSystem);
3744                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3745                                                       bytes_left, is_unicode,
3746                                                       nls_codepage);
3747
3748                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3749
3750                 if ((smb_buffer_response->WordCount == 3) ||
3751                          (smb_buffer_response->WordCount == 7))
3752                         /* field is in same location */
3753                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3754                 else
3755                         tcon->Flags = 0;
3756                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3757         }
3758
3759         cifs_buf_release(smb_buffer);
3760         return rc;
3761 }
3762
3763 static void delayed_free(struct rcu_head *p)
3764 {
3765         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3766
3767         unload_nls(cifs_sb->local_nls);
3768         smb3_cleanup_fs_context(cifs_sb->ctx);
3769         kfree(cifs_sb);
3770 }
3771
3772 void
3773 cifs_umount(struct cifs_sb_info *cifs_sb)
3774 {
3775         struct rb_root *root = &cifs_sb->tlink_tree;
3776         struct rb_node *node;
3777         struct tcon_link *tlink;
3778
3779         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3780
3781         spin_lock(&cifs_sb->tlink_tree_lock);
3782         while ((node = rb_first(root))) {
3783                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3784                 cifs_get_tlink(tlink);
3785                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3786                 rb_erase(node, root);
3787
3788                 spin_unlock(&cifs_sb->tlink_tree_lock);
3789                 cifs_put_tlink(tlink);
3790                 spin_lock(&cifs_sb->tlink_tree_lock);
3791         }
3792         spin_unlock(&cifs_sb->tlink_tree_lock);
3793
3794         kfree(cifs_sb->prepath);
3795 #ifdef CONFIG_CIFS_DFS_UPCALL
3796         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3797 #endif
3798         call_rcu(&cifs_sb->rcu, delayed_free);
3799 }
3800
3801 int
3802 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses)
3803 {
3804         int rc = 0;
3805         struct TCP_Server_Info *server = cifs_ses_server(ses);
3806
3807         if (!server->ops->need_neg || !server->ops->negotiate)
3808                 return -ENOSYS;
3809
3810         /* only send once per connect */
3811         if (!server->ops->need_neg(server))
3812                 return 0;
3813
3814         rc = server->ops->negotiate(xid, ses);
3815         if (rc == 0) {
3816                 spin_lock(&GlobalMid_Lock);
3817                 if (server->tcpStatus == CifsNeedNegotiate)
3818                         server->tcpStatus = CifsGood;
3819                 else
3820                         rc = -EHOSTDOWN;
3821                 spin_unlock(&GlobalMid_Lock);
3822         }
3823
3824         return rc;
3825 }
3826
3827 int
3828 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3829                    struct nls_table *nls_info)
3830 {
3831         int rc = -ENOSYS;
3832         struct TCP_Server_Info *server = cifs_ses_server(ses);
3833
3834         if (!ses->binding) {
3835                 ses->capabilities = server->capabilities;
3836                 if (!linuxExtEnabled)
3837                         ses->capabilities &= (~server->vals->cap_unix);
3838
3839                 if (ses->auth_key.response) {
3840                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3841                                  ses->auth_key.response);
3842                         kfree(ses->auth_key.response);
3843                         ses->auth_key.response = NULL;
3844                         ses->auth_key.len = 0;
3845                 }
3846         }
3847
3848         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3849                  server->sec_mode, server->capabilities, server->timeAdj);
3850
3851         if (server->ops->sess_setup)
3852                 rc = server->ops->sess_setup(xid, ses, nls_info);
3853
3854         if (rc)
3855                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3856
3857         return rc;
3858 }
3859
3860 static int
3861 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3862 {
3863         ctx->sectype = ses->sectype;
3864
3865         /* krb5 is special, since we don't need username or pw */
3866         if (ctx->sectype == Kerberos)
3867                 return 0;
3868
3869         return cifs_set_cifscreds(ctx, ses);
3870 }
3871
3872 static struct cifs_tcon *
3873 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3874 {
3875         int rc;
3876         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3877         struct cifs_ses *ses;
3878         struct cifs_tcon *tcon = NULL;
3879         struct smb3_fs_context *ctx;
3880
3881         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3882         if (ctx == NULL)
3883                 return ERR_PTR(-ENOMEM);
3884
3885         ctx->local_nls = cifs_sb->local_nls;
3886         ctx->linux_uid = fsuid;
3887         ctx->cred_uid = fsuid;
3888         ctx->UNC = master_tcon->treeName;
3889         ctx->retry = master_tcon->retry;
3890         ctx->nocase = master_tcon->nocase;
3891         ctx->nohandlecache = master_tcon->nohandlecache;
3892         ctx->local_lease = master_tcon->local_lease;
3893         ctx->no_lease = master_tcon->no_lease;
3894         ctx->resilient = master_tcon->use_resilient;
3895         ctx->persistent = master_tcon->use_persistent;
3896         ctx->handle_timeout = master_tcon->handle_timeout;
3897         ctx->no_linux_ext = !master_tcon->unix_ext;
3898         ctx->linux_ext = master_tcon->posix_extensions;
3899         ctx->sectype = master_tcon->ses->sectype;
3900         ctx->sign = master_tcon->ses->sign;
3901         ctx->seal = master_tcon->seal;
3902         ctx->witness = master_tcon->use_witness;
3903
3904         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3905         if (rc) {
3906                 tcon = ERR_PTR(rc);
3907                 goto out;
3908         }
3909
3910         /* get a reference for the same TCP session */
3911         spin_lock(&cifs_tcp_ses_lock);
3912         ++master_tcon->ses->server->srv_count;
3913         spin_unlock(&cifs_tcp_ses_lock);
3914
3915         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3916         if (IS_ERR(ses)) {
3917                 tcon = (struct cifs_tcon *)ses;
3918                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3919                 goto out;
3920         }
3921
3922         tcon = cifs_get_tcon(ses, ctx);
3923         if (IS_ERR(tcon)) {
3924                 cifs_put_smb_ses(ses);
3925                 goto out;
3926         }
3927
3928         if (cap_unix(ses))
3929                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3930
3931 out:
3932         kfree(ctx->username);
3933         kfree_sensitive(ctx->password);
3934         kfree(ctx);
3935
3936         return tcon;
3937 }
3938
3939 struct cifs_tcon *
3940 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3941 {
3942         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3943 }
3944
3945 /* find and return a tlink with given uid */
3946 static struct tcon_link *
3947 tlink_rb_search(struct rb_root *root, kuid_t uid)
3948 {
3949         struct rb_node *node = root->rb_node;
3950         struct tcon_link *tlink;
3951
3952         while (node) {
3953                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3954
3955                 if (uid_gt(tlink->tl_uid, uid))
3956                         node = node->rb_left;
3957                 else if (uid_lt(tlink->tl_uid, uid))
3958                         node = node->rb_right;
3959                 else
3960                         return tlink;
3961         }
3962         return NULL;
3963 }
3964
3965 /* insert a tcon_link into the tree */
3966 static void
3967 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3968 {
3969         struct rb_node **new = &(root->rb_node), *parent = NULL;
3970         struct tcon_link *tlink;
3971
3972         while (*new) {
3973                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3974                 parent = *new;
3975
3976                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3977                         new = &((*new)->rb_left);
3978                 else
3979                         new = &((*new)->rb_right);
3980         }
3981
3982         rb_link_node(&new_tlink->tl_rbnode, parent, new);
3983         rb_insert_color(&new_tlink->tl_rbnode, root);
3984 }
3985
3986 /*
3987  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3988  * current task.
3989  *
3990  * If the superblock doesn't refer to a multiuser mount, then just return
3991  * the master tcon for the mount.
3992  *
3993  * First, search the rbtree for an existing tcon for this fsuid. If one
3994  * exists, then check to see if it's pending construction. If it is then wait
3995  * for construction to complete. Once it's no longer pending, check to see if
3996  * it failed and either return an error or retry construction, depending on
3997  * the timeout.
3998  *
3999  * If one doesn't exist then insert a new tcon_link struct into the tree and
4000  * try to construct a new one.
4001  */
4002 struct tcon_link *
4003 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4004 {
4005         int ret;
4006         kuid_t fsuid = current_fsuid();
4007         struct tcon_link *tlink, *newtlink;
4008
4009         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4010                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4011
4012         spin_lock(&cifs_sb->tlink_tree_lock);
4013         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4014         if (tlink)
4015                 cifs_get_tlink(tlink);
4016         spin_unlock(&cifs_sb->tlink_tree_lock);
4017
4018         if (tlink == NULL) {
4019                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4020                 if (newtlink == NULL)
4021                         return ERR_PTR(-ENOMEM);
4022                 newtlink->tl_uid = fsuid;
4023                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4024                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4025                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4026                 cifs_get_tlink(newtlink);
4027
4028                 spin_lock(&cifs_sb->tlink_tree_lock);
4029                 /* was one inserted after previous search? */
4030                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4031                 if (tlink) {
4032                         cifs_get_tlink(tlink);
4033                         spin_unlock(&cifs_sb->tlink_tree_lock);
4034                         kfree(newtlink);
4035                         goto wait_for_construction;
4036                 }
4037                 tlink = newtlink;
4038                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4039                 spin_unlock(&cifs_sb->tlink_tree_lock);
4040         } else {
4041 wait_for_construction:
4042                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4043                                   TASK_INTERRUPTIBLE);
4044                 if (ret) {
4045                         cifs_put_tlink(tlink);
4046                         return ERR_PTR(-ERESTARTSYS);
4047                 }
4048
4049                 /* if it's good, return it */
4050                 if (!IS_ERR(tlink->tl_tcon))
4051                         return tlink;
4052
4053                 /* return error if we tried this already recently */
4054                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4055                         cifs_put_tlink(tlink);
4056                         return ERR_PTR(-EACCES);
4057                 }
4058
4059                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4060                         goto wait_for_construction;
4061         }
4062
4063         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4064         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4065         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4066
4067         if (IS_ERR(tlink->tl_tcon)) {
4068                 cifs_put_tlink(tlink);
4069                 return ERR_PTR(-EACCES);
4070         }
4071
4072         return tlink;
4073 }
4074
4075 /*
4076  * periodic workqueue job that scans tcon_tree for a superblock and closes
4077  * out tcons.
4078  */
4079 static void
4080 cifs_prune_tlinks(struct work_struct *work)
4081 {
4082         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4083                                                     prune_tlinks.work);
4084         struct rb_root *root = &cifs_sb->tlink_tree;
4085         struct rb_node *node;
4086         struct rb_node *tmp;
4087         struct tcon_link *tlink;
4088
4089         /*
4090          * Because we drop the spinlock in the loop in order to put the tlink
4091          * it's not guarded against removal of links from the tree. The only
4092          * places that remove entries from the tree are this function and
4093          * umounts. Because this function is non-reentrant and is canceled
4094          * before umount can proceed, this is safe.
4095          */
4096         spin_lock(&cifs_sb->tlink_tree_lock);
4097         node = rb_first(root);
4098         while (node != NULL) {
4099                 tmp = node;
4100                 node = rb_next(tmp);
4101                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4102
4103                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4104                     atomic_read(&tlink->tl_count) != 0 ||
4105                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4106                         continue;
4107
4108                 cifs_get_tlink(tlink);
4109                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4110                 rb_erase(tmp, root);
4111
4112                 spin_unlock(&cifs_sb->tlink_tree_lock);
4113                 cifs_put_tlink(tlink);
4114                 spin_lock(&cifs_sb->tlink_tree_lock);
4115         }
4116         spin_unlock(&cifs_sb->tlink_tree_lock);
4117
4118         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4119                                 TLINK_IDLE_EXPIRE);
4120 }
4121
4122 #ifdef CONFIG_CIFS_DFS_UPCALL
4123 /* Update dfs referral path of superblock */
4124 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4125                                   const char *target)
4126 {
4127         int rc = 0;
4128         size_t len = strlen(target);
4129         char *refpath, *npath;
4130
4131         if (unlikely(len < 2 || *target != '\\'))
4132                 return -EINVAL;
4133
4134         if (target[1] == '\\') {
4135                 len += 1;
4136                 refpath = kmalloc(len, GFP_KERNEL);
4137                 if (!refpath)
4138                         return -ENOMEM;
4139
4140                 scnprintf(refpath, len, "%s", target);
4141         } else {
4142                 len += sizeof("\\");
4143                 refpath = kmalloc(len, GFP_KERNEL);
4144                 if (!refpath)
4145                         return -ENOMEM;
4146
4147                 scnprintf(refpath, len, "\\%s", target);
4148         }
4149
4150         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4151         kfree(refpath);
4152
4153         if (IS_ERR(npath)) {
4154                 rc = PTR_ERR(npath);
4155         } else {
4156                 mutex_lock(&server->refpath_lock);
4157                 kfree(server->leaf_fullpath);
4158                 server->leaf_fullpath = npath;
4159                 mutex_unlock(&server->refpath_lock);
4160                 server->current_fullpath = server->leaf_fullpath;
4161         }
4162         return rc;
4163 }
4164
4165 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4166                                        size_t tcp_host_len, char *share, bool *target_match)
4167 {
4168         int rc = 0;
4169         const char *dfs_host;
4170         size_t dfs_host_len;
4171
4172         *target_match = true;
4173         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4174
4175         /* Check if hostnames or addresses match */
4176         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4177                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4178                          dfs_host, (int)tcp_host_len, tcp_host);
4179                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4180                 if (rc)
4181                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4182         }
4183         return rc;
4184 }
4185
4186 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4187                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4188                                      struct dfs_cache_tgt_list *tl)
4189 {
4190         int rc;
4191         struct TCP_Server_Info *server = tcon->ses->server;
4192         const struct smb_version_operations *ops = server->ops;
4193         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4194         char *share = NULL, *prefix = NULL;
4195         const char *tcp_host;
4196         size_t tcp_host_len;
4197         struct dfs_cache_tgt_iterator *tit;
4198         bool target_match;
4199
4200         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4201
4202         tit = dfs_cache_get_tgt_iterator(tl);
4203         if (!tit) {
4204                 rc = -ENOENT;
4205                 goto out;
4206         }
4207
4208         /* Try to tree connect to all dfs targets */
4209         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4210                 const char *target = dfs_cache_get_tgt_name(tit);
4211                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4212
4213                 kfree(share);
4214                 kfree(prefix);
4215                 share = prefix = NULL;
4216
4217                 /* Check if share matches with tcp ses */
4218                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4219                 if (rc) {
4220                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4221                         break;
4222                 }
4223
4224                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4225                                                  &target_match);
4226                 if (rc)
4227                         break;
4228                 if (!target_match) {
4229                         rc = -EHOSTUNREACH;
4230                         continue;
4231                 }
4232
4233                 if (ipc->need_reconnect) {
4234                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4235                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4236                         if (rc)
4237                                 break;
4238                 }
4239
4240                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4241                 if (!islink) {
4242                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4243                         break;
4244                 }
4245                 /*
4246                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4247                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4248                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4249                  * newly resolved target.
4250                  */
4251                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4252                                    NULL, &ntl)) {
4253                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4254                         if (rc)
4255                                 continue;
4256                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4257                         if (!rc)
4258                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4259                 } else {
4260                         /* Target is another dfs share */
4261                         rc = update_server_fullpath(server, cifs_sb, target);
4262                         dfs_cache_free_tgts(tl);
4263
4264                         if (!rc) {
4265                                 rc = -EREMOTE;
4266                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4267                         } else
4268                                 dfs_cache_free_tgts(&ntl);
4269                 }
4270                 break;
4271         }
4272
4273 out:
4274         kfree(share);
4275         kfree(prefix);
4276
4277         return rc;
4278 }
4279
4280 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4281                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4282                                    struct dfs_cache_tgt_list *tl)
4283 {
4284         int rc;
4285         int num_links = 0;
4286         struct TCP_Server_Info *server = tcon->ses->server;
4287
4288         do {
4289                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4290                 if (!rc || rc != -EREMOTE)
4291                         break;
4292         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4293         /*
4294          * If we couldn't tree connect to any targets from last referral path, then retry from
4295          * original referral path.
4296          */
4297         if (rc && server->current_fullpath != server->origin_fullpath) {
4298                 server->current_fullpath = server->origin_fullpath;
4299                 cifs_ses_mark_for_reconnect(tcon->ses);
4300         }
4301
4302         dfs_cache_free_tgts(tl);
4303         return rc;
4304 }
4305
4306 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4307 {
4308         int rc;
4309         struct TCP_Server_Info *server = tcon->ses->server;
4310         const struct smb_version_operations *ops = server->ops;
4311         struct super_block *sb = NULL;
4312         struct cifs_sb_info *cifs_sb;
4313         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4314         char *tree;
4315         struct dfs_info3_param ref = {0};
4316
4317         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4318         if (!tree)
4319                 return -ENOMEM;
4320
4321         if (tcon->ipc) {
4322                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4323                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4324                 goto out;
4325         }
4326
4327         sb = cifs_get_tcp_super(server);
4328         if (IS_ERR(sb)) {
4329                 rc = PTR_ERR(sb);
4330                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4331                 goto out;
4332         }
4333
4334         cifs_sb = CIFS_SB(sb);
4335
4336         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4337         if (!server->current_fullpath ||
4338             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4339                 rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls);
4340                 goto out;
4341         }
4342
4343         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4344                                      &tl);
4345         free_dfs_info_param(&ref);
4346
4347 out:
4348         kfree(tree);
4349         cifs_put_tcp_super(sb);
4350
4351         return rc;
4352 }
4353 #else
4354 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4355 {
4356         const struct smb_version_operations *ops = tcon->ses->server->ops;
4357
4358         return ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4359 }
4360 #endif