fs/cifs/connect.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/net.h>
  10 #include <linux/string.h>
  11 #include <linux/sched/mm.h>
  12 #include <linux/sched/signal.h>
  13 #include <linux/list.h>
  14 #include <linux/wait.h>
  15 #include <linux/slab.h>
  16 #include <linux/pagemap.h>
  17 #include <linux/ctype.h>
  18 #include <linux/utsname.h>
  19 #include <linux/mempool.h>
  20 #include <linux/delay.h>
  21 #include <linux/completion.h>
  22 #include <linux/kthread.h>
  23 #include <linux/pagevec.h>
  24 #include <linux/freezer.h>
  25 #include <linux/namei.h>
  26 #include <linux/uuid.h>
  27 #include <linux/uaccess.h>
  28 #include <asm/processor.h>
  29 #include <linux/inet.h>
  30 #include <linux/module.h>
  31 #include <keys/user-type.h>
  32 #include <net/ipv6.h>
  33 #include <linux/parser.h>
  34 #include <linux/bvec.h>
  35 #include "cifspdu.h"
  36 #include "cifsglob.h"
  37 #include "cifsproto.h"
  38 #include "cifs_unicode.h"
  39 #include "cifs_debug.h"
  40 #include "cifs_fs_sb.h"
  41 #include "ntlmssp.h"
  42 #include "nterr.h"
  43 #include "rfc1002pdu.h"
  44 #include "fscache.h"
  45 #include "smb2proto.h"
  46 #include "smbdirect.h"
  47 #include "dns_resolve.h"
  48 #ifdef CONFIG_CIFS_DFS_UPCALL
  49 #include "dfs_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 static int ip_connect(struct TCP_Server_Info *server);
  65 static int generic_ip_connect(struct TCP_Server_Info *server);
  66 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  67 static void cifs_prune_tlinks(struct work_struct *work);
  68
  69 /*
  70  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  71  * get their ip addresses changed at some point.
  72  *
  73  * This should be called with server->srv_mutex held.
  74  */
  75 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  76 {
  77         int rc;
  78         int len;
  79         char *unc, *ipaddr = NULL;
  80         time64_t expiry, now;
  81         unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  82
  83         if (!server->hostname)
  84                 return -EINVAL;
  85
  86         len = strlen(server->hostname) + 3;
  87
  88         unc = kmalloc(len, GFP_KERNEL);
  89         if (!unc) {
  90                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
  91                 return -ENOMEM;
  92         }
  93         scnprintf(unc, len, "\\\\%s", server->hostname);
  94
  95         rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
  96         kfree(unc);
  97
  98         if (rc < 0) {
  99                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 100                          __func__, server->hostname, rc);
 101                 goto requeue_resolve;
 102         }
 103
 104         spin_lock(&cifs_tcp_ses_lock);
 105         rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 106                                   strlen(ipaddr));
 107         spin_unlock(&cifs_tcp_ses_lock);
 108         kfree(ipaddr);
 109
 110         /* rc == 1 means success here */
 111         if (rc) {
 112                 now = ktime_get_real_seconds();
 113                 if (expiry && expiry > now)
 114                         /*
 115                          * To make sure we don't use the cached entry, retry 1s
 116                          * after expiry.
 117                          */
 118                         ttl = (expiry - now + 1);
 119         }
 120         rc = !rc ? -1 : 0;
 121
 122 requeue_resolve:
 123         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 124                  __func__, ttl);
 125         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 126
 127         return rc;
 128 }
 129
 130
 131 static void cifs_resolve_server(struct work_struct *work)
 132 {
 133         int rc;
 134         struct TCP_Server_Info *server = container_of(work,
 135                                         struct TCP_Server_Info, resolve.work);
 136
 137         mutex_lock(&server->srv_mutex);
 138
 139         /*
 140          * Resolve the hostname again to make sure that IP address is up-to-date.
 141          */
 142         rc = reconn_set_ipaddr_from_hostname(server);
 143         if (rc) {
 144                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 145                                 __func__, rc);
 146         }
 147
 148         mutex_unlock(&server->srv_mutex);
 149 }
 150
 151 #ifdef CONFIG_CIFS_DFS_UPCALL
 152 /* These functions must be called with server->srv_mutex held */
 153 static void reconn_set_next_dfs_target(struct TCP_Server_Info *server,
 154                                        struct cifs_sb_info *cifs_sb,
 155                                        struct dfs_cache_tgt_list *tgt_list,
 156                                        struct dfs_cache_tgt_iterator **tgt_it)
 157 {
 158         const char *name;
 159         int rc;
 160
 161         if (!cifs_sb || !cifs_sb->origin_fullpath)
 162                 return;
 163
 164         if (!*tgt_it) {
 165                 *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
 166         } else {
 167                 *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it);
 168                 if (!*tgt_it)
 169                         *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
 170         }
 171
 172         cifs_dbg(FYI, "%s: UNC: %s\n", __func__, cifs_sb->origin_fullpath);
 173
 174         name = dfs_cache_get_tgt_name(*tgt_it);
 175
 176         kfree(server->hostname);
 177
 178         server->hostname = extract_hostname(name);
 179         if (IS_ERR(server->hostname)) {
 180                 cifs_dbg(FYI,
 181                          "%s: failed to extract hostname from target: %ld\n",
 182                          __func__, PTR_ERR(server->hostname));
 183                 return;
 184         }
 185
 186         rc = reconn_set_ipaddr_from_hostname(server);
 187         if (rc) {
 188                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 189                          __func__, rc);
 190         }
 191 }
 192
 193 static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
 194                                            struct dfs_cache_tgt_list *tl)
 195 {
 196         if (!cifs_sb->origin_fullpath)
 197                 return -EOPNOTSUPP;
 198         return dfs_cache_noreq_find(cifs_sb->origin_fullpath + 1, NULL, tl);
 199 }
 200 #endif
 201
 202 /*
 203  * cifs tcp session reconnection
 204  *
 205  * mark tcp session as reconnecting so temporarily locked
 206  * mark all smb sessions as reconnecting for tcp session
 207  * reconnect tcp session
 208  * wake up waiters on reconnection? - (not needed currently)
 209  */
 210 int
 211 cifs_reconnect(struct TCP_Server_Info *server)
 212 {
 213         int rc = 0;
 214         struct list_head *tmp, *tmp2;
 215         struct cifs_ses *ses;
 216         struct cifs_tcon *tcon;
 217         struct mid_q_entry *mid_entry;
 218         struct list_head retry_list;
 219 #ifdef CONFIG_CIFS_DFS_UPCALL
 220         struct super_block *sb = NULL;
 221         struct cifs_sb_info *cifs_sb = NULL;
 222         struct dfs_cache_tgt_list tgt_list = DFS_CACHE_TGT_LIST_INIT(tgt_list);
 223         struct dfs_cache_tgt_iterator *tgt_it = NULL;
 224 #endif
 225
 226         spin_lock(&GlobalMid_Lock);
 227         server->nr_targets = 1;
 228 #ifdef CONFIG_CIFS_DFS_UPCALL
 229         spin_unlock(&GlobalMid_Lock);
 230         sb = cifs_get_tcp_super(server);
 231         if (IS_ERR(sb)) {
 232                 rc = PTR_ERR(sb);
 233                 cifs_dbg(FYI, "%s: will not do DFS failover: rc = %d\n",
 234                          __func__, rc);
 235                 sb = NULL;
 236         } else {
 237                 cifs_sb = CIFS_SB(sb);
 238                 rc = reconn_setup_dfs_targets(cifs_sb, &tgt_list);
 239                 if (rc) {
 240                         cifs_sb = NULL;
 241                         if (rc != -EOPNOTSUPP) {
 242                                 cifs_server_dbg(VFS, "%s: no target servers for DFS failover\n",
 243                                                 __func__);
 244                         }
 245                 } else {
 246                         server->nr_targets = dfs_cache_get_nr_tgts(&tgt_list);
 247                 }
 248         }
 249         cifs_dbg(FYI, "%s: will retry %d target(s)\n", __func__,
 250                  server->nr_targets);
 251         spin_lock(&GlobalMid_Lock);
 252 #endif
 253         if (server->tcpStatus == CifsExiting) {
 254                 /* the demux thread will exit normally
 255                 next time through the loop */
 256                 spin_unlock(&GlobalMid_Lock);
 257 #ifdef CONFIG_CIFS_DFS_UPCALL
 258                 dfs_cache_free_tgts(&tgt_list);
 259                 cifs_put_tcp_super(sb);
 260 #endif
 261                 wake_up(&server->response_q);
 262                 return rc;
 263         } else
 264                 server->tcpStatus = CifsNeedReconnect;
 265         spin_unlock(&GlobalMid_Lock);
 266         server->maxBuf = 0;
 267         server->max_read = 0;
 268
 269         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 270         trace_smb3_reconnect(server->CurrentMid, server->conn_id, server->hostname);
 271
 272         /* before reconnecting the tcp session, mark the smb session (uid)
 273                 and the tid bad so they are not used until reconnected */
 274         cifs_dbg(FYI, "%s: marking sessions and tcons for reconnect\n",
 275                  __func__);
 276         spin_lock(&cifs_tcp_ses_lock);
 277         list_for_each(tmp, &server->smb_ses_list) {
 278                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 279                 ses->need_reconnect = true;
 280                 list_for_each(tmp2, &ses->tcon_list) {
 281                         tcon = list_entry(tmp2, struct cifs_tcon, tcon_list);
 282                         tcon->need_reconnect = true;
 283                 }
 284                 if (ses->tcon_ipc)
 285                         ses->tcon_ipc->need_reconnect = true;
 286         }
 287         spin_unlock(&cifs_tcp_ses_lock);
 288
 289         /* do not want to be sending data on a socket we are freeing */
 290         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 291         mutex_lock(&server->srv_mutex);
 292         if (server->ssocket) {
 293                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n",
 294                          server->ssocket->state, server->ssocket->flags);
 295                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 296                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n",
 297                          server->ssocket->state, server->ssocket->flags);
 298                 sock_release(server->ssocket);
 299                 server->ssocket = NULL;
 300         }
 301         server->sequence_number = 0;
 302         server->session_estab = false;
 303         kfree(server->session_key.response);
 304         server->session_key.response = NULL;
 305         server->session_key.len = 0;
 306         server->lstrp = jiffies;
 307
 308         /* mark submitted MIDs for retry and issue callback */
 309         INIT_LIST_HEAD(&retry_list);
 310         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 311         spin_lock(&GlobalMid_Lock);
 312         list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 313                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 314                 kref_get(&mid_entry->refcount);
 315                 if (mid_entry->mid_state == MID_REQUEST_SUBMITTED)
 316                         mid_entry->mid_state = MID_RETRY_NEEDED;
 317                 list_move(&mid_entry->qhead, &retry_list);
 318                 mid_entry->mid_flags |= MID_DELETED;
 319         }
 320         spin_unlock(&GlobalMid_Lock);
 321         mutex_unlock(&server->srv_mutex);
 322
 323         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 324         list_for_each_safe(tmp, tmp2, &retry_list) {
 325                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 326                 list_del_init(&mid_entry->qhead);
 327                 mid_entry->callback(mid_entry);
 328                 cifs_mid_q_entry_release(mid_entry);
 329         }
 330
 331         if (cifs_rdma_enabled(server)) {
 332                 mutex_lock(&server->srv_mutex);
 333                 smbd_destroy(server);
 334                 mutex_unlock(&server->srv_mutex);
 335         }
 336
 337         do {
 338                 try_to_freeze();
 339
 340                 mutex_lock(&server->srv_mutex);
 341
 342
 343                 if (!cifs_swn_set_server_dstaddr(server)) {
 344 #ifdef CONFIG_CIFS_DFS_UPCALL
 345                 if (cifs_sb && cifs_sb->origin_fullpath)
 346                         /*
 347                          * Set up next DFS target server (if any) for reconnect. If DFS
 348                          * feature is disabled, then we will retry last server we
 349                          * connected to before.
 350                          */
 351                         reconn_set_next_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);
 352                 else {
 353 #endif
 354                         /*
 355                          * Resolve the hostname again to make sure that IP address is up-to-date.
 356                          */
 357                         rc = reconn_set_ipaddr_from_hostname(server);
 358                         if (rc) {
 359                                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 360                                                 __func__, rc);
 361                         }
 362
 363 #ifdef CONFIG_CIFS_DFS_UPCALL
 364                 }
 365 #endif
 366
 367
 368                 }
 369
 370                 if (cifs_rdma_enabled(server))
 371                         rc = smbd_reconnect(server);
 372                 else
 373                         rc = generic_ip_connect(server);
 374                 if (rc) {
 375                         cifs_dbg(FYI, "reconnect error %d\n", rc);
 376                         mutex_unlock(&server->srv_mutex);
 377                         msleep(3000);
 378                 } else {
 379                         atomic_inc(&tcpSesReconnectCount);
 380                         set_credits(server, 1);
 381                         spin_lock(&GlobalMid_Lock);
 382                         if (server->tcpStatus != CifsExiting)
 383                                 server->tcpStatus = CifsNeedNegotiate;
 384                         spin_unlock(&GlobalMid_Lock);
 385                         cifs_swn_reset_server_dstaddr(server);
 386                         mutex_unlock(&server->srv_mutex);
 387                 }
 388         } while (server->tcpStatus == CifsNeedReconnect);
 389
 390 #ifdef CONFIG_CIFS_DFS_UPCALL
 391         if (tgt_it) {
 392                 rc = dfs_cache_noreq_update_tgthint(cifs_sb->origin_fullpath + 1,
 393                                                     tgt_it);
 394                 if (rc) {
 395                         cifs_server_dbg(VFS, "%s: failed to update DFS target hint: rc = %d\n",
 396                                  __func__, rc);
 397                 }
 398                 dfs_cache_free_tgts(&tgt_list);
 399         }
 400
 401         cifs_put_tcp_super(sb);
 402 #endif
 403         if (server->tcpStatus == CifsNeedNegotiate)
 404                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 405
 406         wake_up(&server->response_q);
 407         return rc;
 408 }
 409
 410 static void
 411 cifs_echo_request(struct work_struct *work)
 412 {
 413         int rc;
 414         struct TCP_Server_Info *server = container_of(work,
 415                                         struct TCP_Server_Info, echo.work);
 416
 417         /*
 418          * We cannot send an echo if it is disabled.
 419          * Also, no need to ping if we got a response recently.
 420          */
 421
 422         if (server->tcpStatus == CifsNeedReconnect ||
 423             server->tcpStatus == CifsExiting ||
 424             server->tcpStatus == CifsNew ||
 425             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 426             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 427                 goto requeue_echo;
 428
 429         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 430         if (rc)
 431                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 432                          server->hostname);
 433
 434         /* Check witness registrations */
 435         cifs_swn_check();
 436
 437 requeue_echo:
 438         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 439 }
 440
 441 static bool
 442 allocate_buffers(struct TCP_Server_Info *server)
 443 {
 444         if (!server->bigbuf) {
 445                 server->bigbuf = (char *)cifs_buf_get();
 446                 if (!server->bigbuf) {
 447                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 448                         msleep(3000);
 449                         /* retry will check if exiting */
 450                         return false;
 451                 }
 452         } else if (server->large_buf) {
 453                 /* we are reusing a dirty large buf, clear its start */
 454                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 455         }
 456
 457         if (!server->smallbuf) {
 458                 server->smallbuf = (char *)cifs_small_buf_get();
 459                 if (!server->smallbuf) {
 460                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 461                         msleep(1000);
 462                         /* retry will check if exiting */
 463                         return false;
 464                 }
 465                 /* beginning of smb buffer is cleared in our buf_get */
 466         } else {
 467                 /* if existing small buf clear beginning */
 468                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 469         }
 470
 471         return true;
 472 }
 473
 474 static bool
 475 server_unresponsive(struct TCP_Server_Info *server)
 476 {
 477         /*
 478          * We need to wait 3 echo intervals to make sure we handle such
 479          * situations right:
 480          * 1s  client sends a normal SMB request
 481          * 2s  client gets a response
 482          * 30s echo workqueue job pops, and decides we got a response recently
 483          *     and don't need to send another
 484          * ...
 485          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 486          *     a response in >60s.
 487          */
 488         if ((server->tcpStatus == CifsGood ||
 489             server->tcpStatus == CifsNeedNegotiate) &&
 490             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 491             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 492                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 493                          (3 * server->echo_interval) / HZ);
 494                 cifs_reconnect(server);
 495                 return true;
 496         }
 497
 498         return false;
 499 }
 500
 501 static inline bool
 502 zero_credits(struct TCP_Server_Info *server)
 503 {
 504         int val;
 505
 506         spin_lock(&server->req_lock);
 507         val = server->credits + server->echo_credits + server->oplock_credits;
 508         if (server->in_flight == 0 && val == 0) {
 509                 spin_unlock(&server->req_lock);
 510                 return true;
 511         }
 512         spin_unlock(&server->req_lock);
 513         return false;
 514 }
 515
 516 static int
 517 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 518 {
 519         int length = 0;
 520         int total_read;
 521
 522         smb_msg->msg_control = NULL;
 523         smb_msg->msg_controllen = 0;
 524
 525         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 526                 try_to_freeze();
 527
 528                 /* reconnect if no credits and no requests in flight */
 529                 if (zero_credits(server)) {
 530                         cifs_reconnect(server);
 531                         return -ECONNABORTED;
 532                 }
 533
 534                 if (server_unresponsive(server))
 535                         return -ECONNABORTED;
 536                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 537                         length = smbd_recv(server->smbd_conn, smb_msg);
 538                 else
 539                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 540
 541                 if (server->tcpStatus == CifsExiting)
 542                         return -ESHUTDOWN;
 543
 544                 if (server->tcpStatus == CifsNeedReconnect) {
 545                         cifs_reconnect(server);
 546                         return -ECONNABORTED;
 547                 }
 548
 549                 if (length == -ERESTARTSYS ||
 550                     length == -EAGAIN ||
 551                     length == -EINTR) {
 552                         /*
 553                          * Minimum sleep to prevent looping, allowing socket
 554                          * to clear and app threads to set tcpStatus
 555                          * CifsNeedReconnect if server hung.
 556                          */
 557                         usleep_range(1000, 2000);
 558                         length = 0;
 559                         continue;
 560                 }
 561
 562                 if (length <= 0) {
 563                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 564                         cifs_reconnect(server);
 565                         return -ECONNABORTED;
 566                 }
 567         }
 568         return total_read;
 569 }
 570
 571 int
 572 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 573                       unsigned int to_read)
 574 {
 575         struct msghdr smb_msg;
 576         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 577         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 578
 579         return cifs_readv_from_socket(server, &smb_msg);
 580 }
 581
 582 ssize_t
 583 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 584 {
 585         struct msghdr smb_msg;
 586
 587         /*
 588          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 589          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 590          *  so little to initialize in struct msghdr
 591          */
 592         smb_msg.msg_name = NULL;
 593         smb_msg.msg_namelen = 0;
 594         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 595
 596         return cifs_readv_from_socket(server, &smb_msg);
 597 }
 598
 599 int
 600 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 601         unsigned int page_offset, unsigned int to_read)
 602 {
 603         struct msghdr smb_msg;
 604         struct bio_vec bv = {
 605                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 606         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 607         return cifs_readv_from_socket(server, &smb_msg);
 608 }
 609
 610 static bool
 611 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 612 {
 613         /*
 614          * The first byte big endian of the length field,
 615          * is actually not part of the length but the type
 616          * with the most common, zero, as regular data.
 617          */
 618         switch (type) {
 619         case RFC1002_SESSION_MESSAGE:
 620                 /* Regular SMB response */
 621                 return true;
 622         case RFC1002_SESSION_KEEP_ALIVE:
 623                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 624                 break;
 625         case RFC1002_POSITIVE_SESSION_RESPONSE:
 626                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 627                 break;
 628         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 629                 /*
 630                  * We get this from Windows 98 instead of an error on
 631                  * SMB negprot response.
 632                  */
 633                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 634                 /* give server a second to clean up */
 635                 msleep(1000);
 636                 /*
 637                  * Always try 445 first on reconnect since we get NACK
 638                  * on some if we ever connected to port 139 (the NACK
 639                  * is since we do not begin with RFC1001 session
 640                  * initialize frame).
 641                  */
 642                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 643                 cifs_reconnect(server);
 644                 break;
 645         default:
 646                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 647                 cifs_reconnect(server);
 648         }
 649
 650         return false;
 651 }
 652
 653 void
 654 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 655 {
 656 #ifdef CONFIG_CIFS_STATS2
 657         mid->when_received = jiffies;
 658 #endif
 659         spin_lock(&GlobalMid_Lock);
 660         if (!malformed)
 661                 mid->mid_state = MID_RESPONSE_RECEIVED;
 662         else
 663                 mid->mid_state = MID_RESPONSE_MALFORMED;
 664         /*
 665          * Trying to handle/dequeue a mid after the send_recv()
 666          * function has finished processing it is a bug.
 667          */
 668         if (mid->mid_flags & MID_DELETED)
 669                 pr_warn_once("trying to dequeue a deleted mid\n");
 670         else {
 671                 list_del_init(&mid->qhead);
 672                 mid->mid_flags |= MID_DELETED;
 673         }
 674         spin_unlock(&GlobalMid_Lock);
 675 }
 676
 677 static unsigned int
 678 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 679 {
 680         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 681
 682         /*
 683          * SMB1 does not use credits.
 684          */
 685         if (server->vals->header_preamble_size)
 686                 return 0;
 687
 688         return le16_to_cpu(shdr->CreditRequest);
 689 }
 690
 691 static void
 692 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 693            char *buf, int malformed)
 694 {
 695         if (server->ops->check_trans2 &&
 696             server->ops->check_trans2(mid, server, buf, malformed))
 697                 return;
 698         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 699         mid->resp_buf = buf;
 700         mid->large_buf = server->large_buf;
 701         /* Was previous buf put in mpx struct for multi-rsp? */
 702         if (!mid->multiRsp) {
 703                 /* smb buffer will be freed by user thread */
 704                 if (server->large_buf)
 705                         server->bigbuf = NULL;
 706                 else
 707                         server->smallbuf = NULL;
 708         }
 709         dequeue_mid(mid, malformed);
 710 }
 711
 712 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 713 {
 714         int length;
 715
 716         /* take it off the list, if it's not already */
 717         spin_lock(&cifs_tcp_ses_lock);
 718         list_del_init(&server->tcp_ses_list);
 719         spin_unlock(&cifs_tcp_ses_lock);
 720
 721         cancel_delayed_work_sync(&server->echo);
 722         cancel_delayed_work_sync(&server->resolve);
 723
 724         spin_lock(&GlobalMid_Lock);
 725         server->tcpStatus = CifsExiting;
 726         spin_unlock(&GlobalMid_Lock);
 727         wake_up_all(&server->response_q);
 728
 729         /* check if we have blocked requests that need to free */
 730         spin_lock(&server->req_lock);
 731         if (server->credits <= 0)
 732                 server->credits = 1;
 733         spin_unlock(&server->req_lock);
 734         /*
 735          * Although there should not be any requests blocked on this queue it
 736          * can not hurt to be paranoid and try to wake up requests that may
 737          * haven been blocked when more than 50 at time were on the wire to the
 738          * same server - they now will see the session is in exit state and get
 739          * out of SendReceive.
 740          */
 741         wake_up_all(&server->request_q);
 742         /* give those requests time to exit */
 743         msleep(125);
 744         if (cifs_rdma_enabled(server))
 745                 smbd_destroy(server);
 746         if (server->ssocket) {
 747                 sock_release(server->ssocket);
 748                 server->ssocket = NULL;
 749         }
 750
 751         if (!list_empty(&server->pending_mid_q)) {
 752                 struct list_head dispose_list;
 753                 struct mid_q_entry *mid_entry;
 754                 struct list_head *tmp, *tmp2;
 755
 756                 INIT_LIST_HEAD(&dispose_list);
 757                 spin_lock(&GlobalMid_Lock);
 758                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 759                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 760                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 761                         kref_get(&mid_entry->refcount);
 762                         mid_entry->mid_state = MID_SHUTDOWN;
 763                         list_move(&mid_entry->qhead, &dispose_list);
 764                         mid_entry->mid_flags |= MID_DELETED;
 765                 }
 766                 spin_unlock(&GlobalMid_Lock);
 767
 768                 /* now walk dispose list and issue callbacks */
 769                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 770                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 771                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 772                         list_del_init(&mid_entry->qhead);
 773                         mid_entry->callback(mid_entry);
 774                         cifs_mid_q_entry_release(mid_entry);
 775                 }
 776                 /* 1/8th of sec is more than enough time for them to exit */
 777                 msleep(125);
 778         }
 779
 780         if (!list_empty(&server->pending_mid_q)) {
 781                 /*
 782                  * mpx threads have not exited yet give them at least the smb
 783                  * send timeout time for long ops.
 784                  *
 785                  * Due to delays on oplock break requests, we need to wait at
 786                  * least 45 seconds before giving up on a request getting a
 787                  * response and going ahead and killing cifsd.
 788                  */
 789                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 790                 msleep(46000);
 791                 /*
 792                  * If threads still have not exited they are probably never
 793                  * coming home not much else we can do but free the memory.
 794                  */
 795         }
 796
 797         kfree(server->hostname);
 798         kfree(server);
 799
 800         length = atomic_dec_return(&tcpSesAllocCount);
 801         if (length > 0)
 802                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 803 }
 804
 805 static int
 806 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 807 {
 808         int length;
 809         char *buf = server->smallbuf;
 810         unsigned int pdu_length = server->pdu_size;
 811
 812         /* make sure this will fit in a large buffer */
 813         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
 814                 server->vals->header_preamble_size) {
 815                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 816                 cifs_reconnect(server);
 817                 return -ECONNABORTED;
 818         }
 819
 820         /* switch to large buffer if too big for a small one */
 821         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
 822                 server->large_buf = true;
 823                 memcpy(server->bigbuf, buf, server->total_read);
 824                 buf = server->bigbuf;
 825         }
 826
 827         /* now read the rest */
 828         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
 829                                        pdu_length - HEADER_SIZE(server) + 1
 830                                        + server->vals->header_preamble_size);
 831
 832         if (length < 0)
 833                 return length;
 834         server->total_read += length;
 835
 836         dump_smb(buf, server->total_read);
 837
 838         return cifs_handle_standard(server, mid);
 839 }
 840
 841 int
 842 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 843 {
 844         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
 845         int length;
 846
 847         /*
 848          * We know that we received enough to get to the MID as we
 849          * checked the pdu_length earlier. Now check to see
 850          * if the rest of the header is OK. We borrow the length
 851          * var for the rest of the loop to avoid a new stack var.
 852          *
 853          * 48 bytes is enough to display the header and a little bit
 854          * into the payload for debugging purposes.
 855          */
 856         length = server->ops->check_message(buf, server->total_read, server);
 857         if (length != 0)
 858                 cifs_dump_mem("Bad SMB: ", buf,
 859                         min_t(unsigned int, server->total_read, 48));
 860
 861         if (server->ops->is_session_expired &&
 862             server->ops->is_session_expired(buf)) {
 863                 cifs_reconnect(server);
 864                 return -1;
 865         }
 866
 867         if (server->ops->is_status_pending &&
 868             server->ops->is_status_pending(buf, server))
 869                 return -1;
 870
 871         if (!mid)
 872                 return length;
 873
 874         handle_mid(mid, server, buf, length);
 875         return 0;
 876 }
 877
 878 static void
 879 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 880 {
 881         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 882         int scredits, in_flight;
 883
 884         /*
 885          * SMB1 does not use credits.
 886          */
 887         if (server->vals->header_preamble_size)
 888                 return;
 889
 890         if (shdr->CreditRequest) {
 891                 spin_lock(&server->req_lock);
 892                 server->credits += le16_to_cpu(shdr->CreditRequest);
 893                 scredits = server->credits;
 894                 in_flight = server->in_flight;
 895                 spin_unlock(&server->req_lock);
 896                 wake_up(&server->request_q);
 897
 898                 trace_smb3_add_credits(server->CurrentMid,
 899                                 server->conn_id, server->hostname, scredits,
 900                                 le16_to_cpu(shdr->CreditRequest), in_flight);
 901                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
 902                                 __func__, le16_to_cpu(shdr->CreditRequest),
 903                                 scredits);
 904         }
 905 }
 906
 907
 908 static int
 909 cifs_demultiplex_thread(void *p)
 910 {
 911         int i, num_mids, length;
 912         struct TCP_Server_Info *server = p;
 913         unsigned int pdu_length;
 914         unsigned int next_offset;
 915         char *buf = NULL;
 916         struct task_struct *task_to_wake = NULL;
 917         struct mid_q_entry *mids[MAX_COMPOUND];
 918         char *bufs[MAX_COMPOUND];
 919         unsigned int noreclaim_flag, num_io_timeout = 0;
 920
 921         noreclaim_flag = memalloc_noreclaim_save();
 922         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
 923
 924         length = atomic_inc_return(&tcpSesAllocCount);
 925         if (length > 1)
 926                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 927
 928         set_freezable();
 929         allow_kernel_signal(SIGKILL);
 930         while (server->tcpStatus != CifsExiting) {
 931                 if (try_to_freeze())
 932                         continue;
 933
 934                 if (!allocate_buffers(server))
 935                         continue;
 936
 937                 server->large_buf = false;
 938                 buf = server->smallbuf;
 939                 pdu_length = 4; /* enough to get RFC1001 header */
 940
 941                 length = cifs_read_from_socket(server, buf, pdu_length);
 942                 if (length < 0)
 943                         continue;
 944
 945                 if (server->vals->header_preamble_size == 0)
 946                         server->total_read = 0;
 947                 else
 948                         server->total_read = length;
 949
 950                 /*
 951                  * The right amount was read from socket - 4 bytes,
 952                  * so we can now interpret the length field.
 953                  */
 954                 pdu_length = get_rfc1002_length(buf);
 955
 956                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
 957                 if (!is_smb_response(server, buf[0]))
 958                         continue;
 959 next_pdu:
 960                 server->pdu_size = pdu_length;
 961
 962                 /* make sure we have enough to get to the MID */
 963                 if (server->pdu_size < HEADER_SIZE(server) - 1 -
 964                     server->vals->header_preamble_size) {
 965                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
 966                                  server->pdu_size);
 967                         cifs_reconnect(server);
 968                         continue;
 969                 }
 970
 971                 /* read down to the MID */
 972                 length = cifs_read_from_socket(server,
 973                              buf + server->vals->header_preamble_size,
 974                              HEADER_SIZE(server) - 1
 975                              - server->vals->header_preamble_size);
 976                 if (length < 0)
 977                         continue;
 978                 server->total_read += length;
 979
 980                 if (server->ops->next_header) {
 981                         next_offset = server->ops->next_header(buf);
 982                         if (next_offset)
 983                                 server->pdu_size = next_offset;
 984                 }
 985
 986                 memset(mids, 0, sizeof(mids));
 987                 memset(bufs, 0, sizeof(bufs));
 988                 num_mids = 0;
 989
 990                 if (server->ops->is_transform_hdr &&
 991                     server->ops->receive_transform &&
 992                     server->ops->is_transform_hdr(buf)) {
 993                         length = server->ops->receive_transform(server,
 994                                                                 mids,
 995                                                                 bufs,
 996                                                                 &num_mids);
 997                 } else {
 998                         mids[0] = server->ops->find_mid(server, buf);
 999                         bufs[0] = buf;
1000                         num_mids = 1;
1001
1002                         if (!mids[0] || !mids[0]->receive)
1003                                 length = standard_receive3(server, mids[0]);
1004                         else
1005                                 length = mids[0]->receive(server, mids[0]);
1006                 }
1007
1008                 if (length < 0) {
1009                         for (i = 0; i < num_mids; i++)
1010                                 if (mids[i])
1011                                         cifs_mid_q_entry_release(mids[i]);
1012                         continue;
1013                 }
1014
1015                 if (server->ops->is_status_io_timeout &&
1016                     server->ops->is_status_io_timeout(buf)) {
1017                         num_io_timeout++;
1018                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1019                                 cifs_reconnect(server);
1020                                 num_io_timeout = 0;
1021                                 continue;
1022                         }
1023                 }
1024
1025                 server->lstrp = jiffies;
1026
1027                 for (i = 0; i < num_mids; i++) {
1028                         if (mids[i] != NULL) {
1029                                 mids[i]->resp_buf_size = server->pdu_size;
1030
1031                                 if (bufs[i] && server->ops->is_network_name_deleted)
1032                                         server->ops->is_network_name_deleted(bufs[i],
1033                                                                         server);
1034
1035                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1036                                         mids[i]->callback(mids[i]);
1037
1038                                 cifs_mid_q_entry_release(mids[i]);
1039                         } else if (server->ops->is_oplock_break &&
1040                                    server->ops->is_oplock_break(bufs[i],
1041                                                                 server)) {
1042                                 smb2_add_credits_from_hdr(bufs[i], server);
1043                                 cifs_dbg(FYI, "Received oplock break\n");
1044                         } else {
1045                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1046                                                 atomic_read(&midCount));
1047                                 cifs_dump_mem("Received Data is: ", bufs[i],
1048                                               HEADER_SIZE(server));
1049                                 smb2_add_credits_from_hdr(bufs[i], server);
1050 #ifdef CONFIG_CIFS_DEBUG2
1051                                 if (server->ops->dump_detail)
1052                                         server->ops->dump_detail(bufs[i],
1053                                                                  server);
1054                                 cifs_dump_mids(server);
1055 #endif /* CIFS_DEBUG2 */
1056                         }
1057                 }
1058
1059                 if (pdu_length > server->pdu_size) {
1060                         if (!allocate_buffers(server))
1061                                 continue;
1062                         pdu_length -= server->pdu_size;
1063                         server->total_read = 0;
1064                         server->large_buf = false;
1065                         buf = server->smallbuf;
1066                         goto next_pdu;
1067                 }
1068         } /* end while !EXITING */
1069
1070         /* buffer usually freed in free_mid - need to free it here on exit */
1071         cifs_buf_release(server->bigbuf);
1072         if (server->smallbuf) /* no sense logging a debug message if NULL */
1073                 cifs_small_buf_release(server->smallbuf);
1074
1075         task_to_wake = xchg(&server->tsk, NULL);
1076         clean_demultiplex_info(server);
1077
1078         /* if server->tsk was NULL then wait for a signal before exiting */
1079         if (!task_to_wake) {
1080                 set_current_state(TASK_INTERRUPTIBLE);
1081                 while (!signal_pending(current)) {
1082                         schedule();
1083                         set_current_state(TASK_INTERRUPTIBLE);
1084                 }
1085                 set_current_state(TASK_RUNNING);
1086         }
1087
1088         memalloc_noreclaim_restore(noreclaim_flag);
1089         module_put_and_exit(0);
1090 }
1091
1092 /*
1093  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1094  * if srcaddr is specified and matches the IP address of the rhs argument
1095  */
1096 bool
1097 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1098 {
1099         switch (srcaddr->sa_family) {
1100         case AF_UNSPEC:
1101                 return (rhs->sa_family == AF_UNSPEC);
1102         case AF_INET: {
1103                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1104                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1105                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1106         }
1107         case AF_INET6: {
1108                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1109                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1110                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1111         }
1112         default:
1113                 WARN_ON(1);
1114                 return false; /* don't expect to be here */
1115         }
1116 }
1117
1118 /*
1119  * If no port is specified in addr structure, we try to match with 445 port
1120  * and if it fails - with 139 ports. It should be called only if address
1121  * families of server and addr are equal.
1122  */
1123 static bool
1124 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1125 {
1126         __be16 port, *sport;
1127
1128         /* SMBDirect manages its own ports, don't match it here */
1129         if (server->rdma)
1130                 return true;
1131
1132         switch (addr->sa_family) {
1133         case AF_INET:
1134                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1135                 port = ((struct sockaddr_in *) addr)->sin_port;
1136                 break;
1137         case AF_INET6:
1138                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1139                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1140                 break;
1141         default:
1142                 WARN_ON(1);
1143                 return false;
1144         }
1145
1146         if (!port) {
1147                 port = htons(CIFS_PORT);
1148                 if (port == *sport)
1149                         return true;
1150
1151                 port = htons(RFC1001_PORT);
1152         }
1153
1154         return port == *sport;
1155 }
1156
1157 static bool
1158 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1159               struct sockaddr *srcaddr)
1160 {
1161         switch (addr->sa_family) {
1162         case AF_INET: {
1163                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1164                 struct sockaddr_in *srv_addr4 =
1165                                         (struct sockaddr_in *)&server->dstaddr;
1166
1167                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1168                         return false;
1169                 break;
1170         }
1171         case AF_INET6: {
1172                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1173                 struct sockaddr_in6 *srv_addr6 =
1174                                         (struct sockaddr_in6 *)&server->dstaddr;
1175
1176                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1177                                      &srv_addr6->sin6_addr))
1178                         return false;
1179                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1180                         return false;
1181                 break;
1182         }
1183         default:
1184                 WARN_ON(1);
1185                 return false; /* don't expect to be here */
1186         }
1187
1188         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1189                 return false;
1190
1191         return true;
1192 }
1193
1194 static bool
1195 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1196 {
1197         /*
1198          * The select_sectype function should either return the ctx->sectype
1199          * that was specified, or "Unspecified" if that sectype was not
1200          * compatible with the given NEGOTIATE request.
1201          */
1202         if (server->ops->select_sectype(server, ctx->sectype)
1203              == Unspecified)
1204                 return false;
1205
1206         /*
1207          * Now check if signing mode is acceptable. No need to check
1208          * global_secflags at this point since if MUST_SIGN is set then
1209          * the server->sign had better be too.
1210          */
1211         if (ctx->sign && !server->sign)
1212                 return false;
1213
1214         return true;
1215 }
1216
1217 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1218 {
1219         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1220
1221         if (ctx->nosharesock)
1222                 return 0;
1223
1224         /* If multidialect negotiation see if existing sessions match one */
1225         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1226                 if (server->vals->protocol_id < SMB30_PROT_ID)
1227                         return 0;
1228         } else if (strcmp(ctx->vals->version_string,
1229                    SMBDEFAULT_VERSION_STRING) == 0) {
1230                 if (server->vals->protocol_id < SMB21_PROT_ID)
1231                         return 0;
1232         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1233                 return 0;
1234
1235         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1236                 return 0;
1237
1238         if (!match_address(server, addr,
1239                            (struct sockaddr *)&ctx->srcaddr))
1240                 return 0;
1241
1242         if (!match_port(server, addr))
1243                 return 0;
1244
1245         if (!match_security(server, ctx))
1246                 return 0;
1247
1248         if (server->echo_interval != ctx->echo_interval * HZ)
1249                 return 0;
1250
1251         if (server->rdma != ctx->rdma)
1252                 return 0;
1253
1254         if (server->ignore_signature != ctx->ignore_signature)
1255                 return 0;
1256
1257         if (server->min_offload != ctx->min_offload)
1258                 return 0;
1259
1260         return 1;
1261 }
1262
1263 struct TCP_Server_Info *
1264 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1265 {
1266         struct TCP_Server_Info *server;
1267
1268         spin_lock(&cifs_tcp_ses_lock);
1269         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1270 #ifdef CONFIG_CIFS_DFS_UPCALL
1271                 /*
1272                  * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
1273                  * DFS connections to do failover properly, so avoid sharing them with regular
1274                  * shares or even links that may connect to same server but having completely
1275                  * different failover targets.
1276                  */
1277                 if (server->is_dfs_conn)
1278                         continue;
1279 #endif
1280                 /*
1281                  * Skip ses channels since they're only handled in lower layers
1282                  * (e.g. cifs_send_recv).
1283                  */
1284                 if (server->is_channel || !match_server(server, ctx))
1285                         continue;
1286
1287                 ++server->srv_count;
1288                 spin_unlock(&cifs_tcp_ses_lock);
1289                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1290                 return server;
1291         }
1292         spin_unlock(&cifs_tcp_ses_lock);
1293         return NULL;
1294 }
1295
1296 void
1297 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1298 {
1299         struct task_struct *task;
1300
1301         spin_lock(&cifs_tcp_ses_lock);
1302         if (--server->srv_count > 0) {
1303                 spin_unlock(&cifs_tcp_ses_lock);
1304                 return;
1305         }
1306
1307         /* srv_count can never go negative */
1308         WARN_ON(server->srv_count < 0);
1309
1310         put_net(cifs_net_ns(server));
1311
1312         list_del_init(&server->tcp_ses_list);
1313         spin_unlock(&cifs_tcp_ses_lock);
1314
1315         cancel_delayed_work_sync(&server->echo);
1316         cancel_delayed_work_sync(&server->resolve);
1317
1318         if (from_reconnect)
1319                 /*
1320                  * Avoid deadlock here: reconnect work calls
1321                  * cifs_put_tcp_session() at its end. Need to be sure
1322                  * that reconnect work does nothing with server pointer after
1323                  * that step.
1324                  */
1325                 cancel_delayed_work(&server->reconnect);
1326         else
1327                 cancel_delayed_work_sync(&server->reconnect);
1328
1329         spin_lock(&GlobalMid_Lock);
1330         server->tcpStatus = CifsExiting;
1331         spin_unlock(&GlobalMid_Lock);
1332
1333         cifs_crypto_secmech_release(server);
1334         cifs_fscache_release_client_cookie(server);
1335
1336         kfree(server->session_key.response);
1337         server->session_key.response = NULL;
1338         server->session_key.len = 0;
1339
1340         task = xchg(&server->tsk, NULL);
1341         if (task)
1342                 send_sig(SIGKILL, task, 1);
1343 }
1344
1345 struct TCP_Server_Info *
1346 cifs_get_tcp_session(struct smb3_fs_context *ctx)
1347 {
1348         struct TCP_Server_Info *tcp_ses = NULL;
1349         int rc;
1350
1351         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1352
1353         /* see if we already have a matching tcp_ses */
1354         tcp_ses = cifs_find_tcp_session(ctx);
1355         if (tcp_ses)
1356                 return tcp_ses;
1357
1358         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1359         if (!tcp_ses) {
1360                 rc = -ENOMEM;
1361                 goto out_err;
1362         }
1363
1364         tcp_ses->ops = ctx->ops;
1365         tcp_ses->vals = ctx->vals;
1366         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1367         tcp_ses->hostname = extract_hostname(ctx->UNC);
1368         if (IS_ERR(tcp_ses->hostname)) {
1369                 rc = PTR_ERR(tcp_ses->hostname);
1370                 goto out_err_crypto_release;
1371         }
1372
1373         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1374         tcp_ses->noblockcnt = ctx->rootfs;
1375         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1376         tcp_ses->noautotune = ctx->noautotune;
1377         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1378         tcp_ses->rdma = ctx->rdma;
1379         tcp_ses->in_flight = 0;
1380         tcp_ses->max_in_flight = 0;
1381         tcp_ses->credits = 1;
1382         init_waitqueue_head(&tcp_ses->response_q);
1383         init_waitqueue_head(&tcp_ses->request_q);
1384         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1385         mutex_init(&tcp_ses->srv_mutex);
1386         memcpy(tcp_ses->workstation_RFC1001_name,
1387                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1388         memcpy(tcp_ses->server_RFC1001_name,
1389                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1390         tcp_ses->session_estab = false;
1391         tcp_ses->sequence_number = 0;
1392         tcp_ses->reconnect_instance = 1;
1393         tcp_ses->lstrp = jiffies;
1394         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1395         spin_lock_init(&tcp_ses->req_lock);
1396         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1397         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1398         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1399         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1400         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1401         mutex_init(&tcp_ses->reconnect_mutex);
1402         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1403                sizeof(tcp_ses->srcaddr));
1404         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1405                 sizeof(tcp_ses->dstaddr));
1406         if (ctx->use_client_guid)
1407                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1408                        SMB2_CLIENT_GUID_SIZE);
1409         else
1410                 generate_random_uuid(tcp_ses->client_guid);
1411         /*
1412          * at this point we are the only ones with the pointer
1413          * to the struct since the kernel thread not created yet
1414          * no need to spinlock this init of tcpStatus or srv_count
1415          */
1416         tcp_ses->tcpStatus = CifsNew;
1417         ++tcp_ses->srv_count;
1418
1419         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1420                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1421                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1422         else
1423                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1424         if (tcp_ses->rdma) {
1425 #ifndef CONFIG_CIFS_SMB_DIRECT
1426                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1427                 rc = -ENOENT;
1428                 goto out_err_crypto_release;
1429 #endif
1430                 tcp_ses->smbd_conn = smbd_get_connection(
1431                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1432                 if (tcp_ses->smbd_conn) {
1433                         cifs_dbg(VFS, "RDMA transport established\n");
1434                         rc = 0;
1435                         goto smbd_connected;
1436                 } else {
1437                         rc = -ENOENT;
1438                         goto out_err_crypto_release;
1439                 }
1440         }
1441         rc = ip_connect(tcp_ses);
1442         if (rc < 0) {
1443                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1444                 goto out_err_crypto_release;
1445         }
1446 smbd_connected:
1447         /*
1448          * since we're in a cifs function already, we know that
1449          * this will succeed. No need for try_module_get().
1450          */
1451         __module_get(THIS_MODULE);
1452         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1453                                   tcp_ses, "cifsd");
1454         if (IS_ERR(tcp_ses->tsk)) {
1455                 rc = PTR_ERR(tcp_ses->tsk);
1456                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1457                 module_put(THIS_MODULE);
1458                 goto out_err_crypto_release;
1459         }
1460         tcp_ses->min_offload = ctx->min_offload;
1461         /*
1462          * at this point we are the only ones with the pointer
1463          * to the struct since the kernel thread not created yet
1464          * no need to spinlock this update of tcpStatus
1465          */
1466         tcp_ses->tcpStatus = CifsNeedNegotiate;
1467
1468         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1469                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1470         else
1471                 tcp_ses->max_credits = ctx->max_credits;
1472
1473         tcp_ses->nr_targets = 1;
1474         tcp_ses->ignore_signature = ctx->ignore_signature;
1475         /* thread spawned, put it on the list */
1476         spin_lock(&cifs_tcp_ses_lock);
1477         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1478         spin_unlock(&cifs_tcp_ses_lock);
1479
1480         cifs_fscache_get_client_cookie(tcp_ses);
1481
1482         /* queue echo request delayed work */
1483         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1484
1485         /* queue dns resolution delayed work */
1486         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1487                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1488
1489         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1490
1491         return tcp_ses;
1492
1493 out_err_crypto_release:
1494         cifs_crypto_secmech_release(tcp_ses);
1495
1496         put_net(cifs_net_ns(tcp_ses));
1497
1498 out_err:
1499         if (tcp_ses) {
1500                 if (!IS_ERR(tcp_ses->hostname))
1501                         kfree(tcp_ses->hostname);
1502                 if (tcp_ses->ssocket)
1503                         sock_release(tcp_ses->ssocket);
1504                 kfree(tcp_ses);
1505         }
1506         return ERR_PTR(rc);
1507 }
1508
1509 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1510 {
1511         if (ctx->sectype != Unspecified &&
1512             ctx->sectype != ses->sectype)
1513                 return 0;
1514
1515         /*
1516          * If an existing session is limited to less channels than
1517          * requested, it should not be reused
1518          */
1519         if (ses->chan_max < ctx->max_channels)
1520                 return 0;
1521
1522         switch (ses->sectype) {
1523         case Kerberos:
1524                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1525                         return 0;
1526                 break;
1527         default:
1528                 /* NULL username means anonymous session */
1529                 if (ses->user_name == NULL) {
1530                         if (!ctx->nullauth)
1531                                 return 0;
1532                         break;
1533                 }
1534
1535                 /* anything else takes username/password */
1536                 if (strncmp(ses->user_name,
1537                             ctx->username ? ctx->username : "",
1538                             CIFS_MAX_USERNAME_LEN))
1539                         return 0;
1540                 if ((ctx->username && strlen(ctx->username) != 0) &&
1541                     ses->password != NULL &&
1542                     strncmp(ses->password,
1543                             ctx->password ? ctx->password : "",
1544                             CIFS_MAX_PASSWORD_LEN))
1545                         return 0;
1546         }
1547         return 1;
1548 }
1549
1550 /**
1551  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1552  * @ses: smb session to issue the request on
1553  * @ctx: the superblock configuration context to use for building the
1554  *       new tree connection for the IPC (interprocess communication RPC)
1555  *
1556  * A new IPC connection is made and stored in the session
1557  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1558  */
1559 static int
1560 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1561 {
1562         int rc = 0, xid;
1563         struct cifs_tcon *tcon;
1564         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1565         bool seal = false;
1566         struct TCP_Server_Info *server = ses->server;
1567
1568         /*
1569          * If the mount request that resulted in the creation of the
1570          * session requires encryption, force IPC to be encrypted too.
1571          */
1572         if (ctx->seal) {
1573                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1574                         seal = true;
1575                 else {
1576                         cifs_server_dbg(VFS,
1577                                  "IPC: server doesn't support encryption\n");
1578                         return -EOPNOTSUPP;
1579                 }
1580         }
1581
1582         tcon = tconInfoAlloc();
1583         if (tcon == NULL)
1584                 return -ENOMEM;
1585
1586         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1587
1588         xid = get_xid();
1589         tcon->ses = ses;
1590         tcon->ipc = true;
1591         tcon->seal = seal;
1592         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1593         free_xid(xid);
1594
1595         if (rc) {
1596                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1597                 tconInfoFree(tcon);
1598                 goto out;
1599         }
1600
1601         cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid);
1602
1603         ses->tcon_ipc = tcon;
1604 out:
1605         return rc;
1606 }
1607
1608 /**
1609  * cifs_free_ipc - helper to release the session IPC tcon
1610  * @ses: smb session to unmount the IPC from
1611  *
1612  * Needs to be called everytime a session is destroyed.
1613  *
1614  * On session close, the IPC is closed and the server must release all tcons of the session.
1615  * No need to send a tree disconnect here.
1616  *
1617  * Besides, it will make the server to not close durable and resilient files on session close, as
1618  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1619  */
1620 static int
1621 cifs_free_ipc(struct cifs_ses *ses)
1622 {
1623         struct cifs_tcon *tcon = ses->tcon_ipc;
1624
1625         if (tcon == NULL)
1626                 return 0;
1627
1628         tconInfoFree(tcon);
1629         ses->tcon_ipc = NULL;
1630         return 0;
1631 }
1632
1633 static struct cifs_ses *
1634 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1635 {
1636         struct cifs_ses *ses;
1637
1638         spin_lock(&cifs_tcp_ses_lock);
1639         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1640                 if (ses->status == CifsExiting)
1641                         continue;
1642                 if (!match_session(ses, ctx))
1643                         continue;
1644                 ++ses->ses_count;
1645                 spin_unlock(&cifs_tcp_ses_lock);
1646                 return ses;
1647         }
1648         spin_unlock(&cifs_tcp_ses_lock);
1649         return NULL;
1650 }
1651
1652 void cifs_put_smb_ses(struct cifs_ses *ses)
1653 {
1654         unsigned int rc, xid;
1655         struct TCP_Server_Info *server = ses->server;
1656         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1657
1658         spin_lock(&cifs_tcp_ses_lock);
1659         if (ses->status == CifsExiting) {
1660                 spin_unlock(&cifs_tcp_ses_lock);
1661                 return;
1662         }
1663
1664         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1665         cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE");
1666
1667         if (--ses->ses_count > 0) {
1668                 spin_unlock(&cifs_tcp_ses_lock);
1669                 return;
1670         }
1671         spin_unlock(&cifs_tcp_ses_lock);
1672
1673         /* ses_count can never go negative */
1674         WARN_ON(ses->ses_count < 0);
1675
1676         spin_lock(&GlobalMid_Lock);
1677         if (ses->status == CifsGood)
1678                 ses->status = CifsExiting;
1679         spin_unlock(&GlobalMid_Lock);
1680
1681         cifs_free_ipc(ses);
1682
1683         if (ses->status == CifsExiting && server->ops->logoff) {
1684                 xid = get_xid();
1685                 rc = server->ops->logoff(xid, ses);
1686                 if (rc)
1687                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1688                                 __func__, rc);
1689                 _free_xid(xid);
1690         }
1691
1692         spin_lock(&cifs_tcp_ses_lock);
1693         list_del_init(&ses->smb_ses_list);
1694         spin_unlock(&cifs_tcp_ses_lock);
1695
1696         /* close any extra channels */
1697         if (ses->chan_count > 1) {
1698                 int i;
1699
1700                 for (i = 1; i < ses->chan_count; i++)
1701                         cifs_put_tcp_session(ses->chans[i].server, 0);
1702         }
1703
1704         sesInfoFree(ses);
1705         cifs_put_tcp_session(server, 0);
1706 }
1707
1708 #ifdef CONFIG_KEYS
1709
1710 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1711 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1712
1713 /* Populate username and pw fields from keyring if possible */
1714 static int
1715 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1716 {
1717         int rc = 0;
1718         int is_domain = 0;
1719         const char *delim, *payload;
1720         char *desc;
1721         ssize_t len;
1722         struct key *key;
1723         struct TCP_Server_Info *server = ses->server;
1724         struct sockaddr_in *sa;
1725         struct sockaddr_in6 *sa6;
1726         const struct user_key_payload *upayload;
1727
1728         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1729         if (!desc)
1730                 return -ENOMEM;
1731
1732         /* try to find an address key first */
1733         switch (server->dstaddr.ss_family) {
1734         case AF_INET:
1735                 sa = (struct sockaddr_in *)&server->dstaddr;
1736                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1737                 break;
1738         case AF_INET6:
1739                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1740                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1741                 break;
1742         default:
1743                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1744                          server->dstaddr.ss_family);
1745                 rc = -EINVAL;
1746                 goto out_err;
1747         }
1748
1749         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1750         key = request_key(&key_type_logon, desc, "");
1751         if (IS_ERR(key)) {
1752                 if (!ses->domainName) {
1753                         cifs_dbg(FYI, "domainName is NULL\n");
1754                         rc = PTR_ERR(key);
1755                         goto out_err;
1756                 }
1757
1758                 /* didn't work, try to find a domain key */
1759                 sprintf(desc, "cifs:d:%s", ses->domainName);
1760                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1761                 key = request_key(&key_type_logon, desc, "");
1762                 if (IS_ERR(key)) {
1763                         rc = PTR_ERR(key);
1764                         goto out_err;
1765                 }
1766                 is_domain = 1;
1767         }
1768
1769         down_read(&key->sem);
1770         upayload = user_key_payload_locked(key);
1771         if (IS_ERR_OR_NULL(upayload)) {
1772                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1773                 goto out_key_put;
1774         }
1775
1776         /* find first : in payload */
1777         payload = upayload->data;
1778         delim = strnchr(payload, upayload->datalen, ':');
1779         cifs_dbg(FYI, "payload=%s\n", payload);
1780         if (!delim) {
1781                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1782                          upayload->datalen);
1783                 rc = -EINVAL;
1784                 goto out_key_put;
1785         }
1786
1787         len = delim - payload;
1788         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1789                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1790                          len);
1791                 rc = -EINVAL;
1792                 goto out_key_put;
1793         }
1794
1795         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1796         if (!ctx->username) {
1797                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1798                          len);
1799                 rc = -ENOMEM;
1800                 goto out_key_put;
1801         }
1802         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
1803
1804         len = key->datalen - (len + 1);
1805         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
1806                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
1807                 rc = -EINVAL;
1808                 kfree(ctx->username);
1809                 ctx->username = NULL;
1810                 goto out_key_put;
1811         }
1812
1813         ++delim;
1814         ctx->password = kstrndup(delim, len, GFP_KERNEL);
1815         if (!ctx->password) {
1816                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
1817                          len);
1818                 rc = -ENOMEM;
1819                 kfree(ctx->username);
1820                 ctx->username = NULL;
1821                 goto out_key_put;
1822         }
1823
1824         /*
1825          * If we have a domain key then we must set the domainName in the
1826          * for the request.
1827          */
1828         if (is_domain && ses->domainName) {
1829                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
1830                 if (!ctx->domainname) {
1831                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
1832                                  len);
1833                         rc = -ENOMEM;
1834                         kfree(ctx->username);
1835                         ctx->username = NULL;
1836                         kfree_sensitive(ctx->password);
1837                         ctx->password = NULL;
1838                         goto out_key_put;
1839                 }
1840         }
1841
1842 out_key_put:
1843         up_read(&key->sem);
1844         key_put(key);
1845 out_err:
1846         kfree(desc);
1847         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
1848         return rc;
1849 }
1850 #else /* ! CONFIG_KEYS */
1851 static inline int
1852 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
1853                    struct cifs_ses *ses __attribute__((unused)))
1854 {
1855         return -ENOSYS;
1856 }
1857 #endif /* CONFIG_KEYS */
1858
1859 /**
1860  * cifs_get_smb_ses - get a session matching @ctx data from @server
1861  * @server: server to setup the session to
1862  * @ctx: superblock configuration context to use to setup the session
1863  *
1864  * This function assumes it is being called from cifs_mount() where we
1865  * already got a server reference (server refcount +1). See
1866  * cifs_get_tcon() for refcount explanations.
1867  */
1868 struct cifs_ses *
1869 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1870 {
1871         int rc = -ENOMEM;
1872         unsigned int xid;
1873         struct cifs_ses *ses;
1874         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
1875         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
1876
1877         xid = get_xid();
1878
1879         ses = cifs_find_smb_ses(server, ctx);
1880         if (ses) {
1881                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
1882                          ses->status);
1883
1884                 mutex_lock(&ses->session_mutex);
1885                 rc = cifs_negotiate_protocol(xid, ses);
1886                 if (rc) {
1887                         mutex_unlock(&ses->session_mutex);
1888                         /* problem -- put our ses reference */
1889                         cifs_put_smb_ses(ses);
1890                         free_xid(xid);
1891                         return ERR_PTR(rc);
1892                 }
1893                 if (ses->need_reconnect) {
1894                         cifs_dbg(FYI, "Session needs reconnect\n");
1895                         rc = cifs_setup_session(xid, ses,
1896                                                 ctx->local_nls);
1897                         if (rc) {
1898                                 mutex_unlock(&ses->session_mutex);
1899                                 /* problem -- put our reference */
1900                                 cifs_put_smb_ses(ses);
1901                                 free_xid(xid);
1902                                 return ERR_PTR(rc);
1903                         }
1904                 }
1905                 mutex_unlock(&ses->session_mutex);
1906
1907                 /* existing SMB ses has a server reference already */
1908                 cifs_put_tcp_session(server, 0);
1909                 free_xid(xid);
1910                 return ses;
1911         }
1912
1913         cifs_dbg(FYI, "Existing smb sess not found\n");
1914         ses = sesInfoAlloc();
1915         if (ses == NULL)
1916                 goto get_ses_fail;
1917
1918         /* new SMB session uses our server ref */
1919         ses->server = server;
1920         if (server->dstaddr.ss_family == AF_INET6)
1921                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
1922         else
1923                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
1924
1925         if (ctx->username) {
1926                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
1927                 if (!ses->user_name)
1928                         goto get_ses_fail;
1929         }
1930
1931         /* ctx->password freed at unmount */
1932         if (ctx->password) {
1933                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
1934                 if (!ses->password)
1935                         goto get_ses_fail;
1936         }
1937         if (ctx->domainname) {
1938                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
1939                 if (!ses->domainName)
1940                         goto get_ses_fail;
1941         }
1942         if (ctx->domainauto)
1943                 ses->domainAuto = ctx->domainauto;
1944         ses->cred_uid = ctx->cred_uid;
1945         ses->linux_uid = ctx->linux_uid;
1946
1947         ses->sectype = ctx->sectype;
1948         ses->sign = ctx->sign;
1949         mutex_lock(&ses->session_mutex);
1950
1951         /* add server as first channel */
1952         ses->chans[0].server = server;
1953         ses->chan_count = 1;
1954         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
1955
1956         rc = cifs_negotiate_protocol(xid, ses);
1957         if (!rc)
1958                 rc = cifs_setup_session(xid, ses, ctx->local_nls);
1959
1960         /* each channel uses a different signing key */
1961         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
1962                sizeof(ses->smb3signingkey));
1963
1964         mutex_unlock(&ses->session_mutex);
1965         if (rc)
1966                 goto get_ses_fail;
1967
1968         /* success, put it on the list and add it as first channel */
1969         spin_lock(&cifs_tcp_ses_lock);
1970         list_add(&ses->smb_ses_list, &server->smb_ses_list);
1971         spin_unlock(&cifs_tcp_ses_lock);
1972
1973         free_xid(xid);
1974
1975         cifs_setup_ipc(ses, ctx);
1976
1977         return ses;
1978
1979 get_ses_fail:
1980         sesInfoFree(ses);
1981         free_xid(xid);
1982         return ERR_PTR(rc);
1983 }
1984
1985 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
1986 {
1987         if (tcon->tidStatus == CifsExiting)
1988                 return 0;
1989         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
1990                 return 0;
1991         if (tcon->seal != ctx->seal)
1992                 return 0;
1993         if (tcon->snapshot_time != ctx->snapshot_time)
1994                 return 0;
1995         if (tcon->handle_timeout != ctx->handle_timeout)
1996                 return 0;
1997         if (tcon->no_lease != ctx->no_lease)
1998                 return 0;
1999         if (tcon->nodelete != ctx->nodelete)
2000                 return 0;
2001         return 1;
2002 }
2003
2004 static struct cifs_tcon *
2005 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2006 {
2007         struct list_head *tmp;
2008         struct cifs_tcon *tcon;
2009
2010         spin_lock(&cifs_tcp_ses_lock);
2011         list_for_each(tmp, &ses->tcon_list) {
2012                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
2013
2014                 if (!match_tcon(tcon, ctx))
2015                         continue;
2016                 ++tcon->tc_count;
2017                 spin_unlock(&cifs_tcp_ses_lock);
2018                 return tcon;
2019         }
2020         spin_unlock(&cifs_tcp_ses_lock);
2021         return NULL;
2022 }
2023
2024 void
2025 cifs_put_tcon(struct cifs_tcon *tcon)
2026 {
2027         unsigned int xid;
2028         struct cifs_ses *ses;
2029
2030         /*
2031          * IPC tcon share the lifetime of their session and are
2032          * destroyed in the session put function
2033          */
2034         if (tcon == NULL || tcon->ipc)
2035                 return;
2036
2037         ses = tcon->ses;
2038         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2039         spin_lock(&cifs_tcp_ses_lock);
2040         if (--tcon->tc_count > 0) {
2041                 spin_unlock(&cifs_tcp_ses_lock);
2042                 return;
2043         }
2044
2045         /* tc_count can never go negative */
2046         WARN_ON(tcon->tc_count < 0);
2047
2048         if (tcon->use_witness) {
2049                 int rc;
2050
2051                 rc = cifs_swn_unregister(tcon);
2052                 if (rc < 0) {
2053                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2054                                         __func__, rc);
2055                 }
2056         }
2057
2058         list_del_init(&tcon->tcon_list);
2059         spin_unlock(&cifs_tcp_ses_lock);
2060
2061         xid = get_xid();
2062         if (ses->server->ops->tree_disconnect)
2063                 ses->server->ops->tree_disconnect(xid, tcon);
2064         _free_xid(xid);
2065
2066         cifs_fscache_release_super_cookie(tcon);
2067         tconInfoFree(tcon);
2068         cifs_put_smb_ses(ses);
2069 }
2070
2071 /**
2072  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2073  * @ses: smb session to issue the request on
2074  * @ctx: the superblock configuration context to use for building the
2075  *
2076  * - tcon refcount is the number of mount points using the tcon.
2077  * - ses refcount is the number of tcon using the session.
2078  *
2079  * 1. This function assumes it is being called from cifs_mount() where
2080  *    we already got a session reference (ses refcount +1).
2081  *
2082  * 2. Since we're in the context of adding a mount point, the end
2083  *    result should be either:
2084  *
2085  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2086  *    its session refcount incremented (1 new tcon). This +1 was
2087  *    already done in (1).
2088  *
2089  * b) an existing tcon with refcount+1 (add a mount point to it) and
2090  *    identical ses refcount (no new tcon). Because of (1) we need to
2091  *    decrement the ses refcount.
2092  */
2093 static struct cifs_tcon *
2094 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2095 {
2096         int rc, xid;
2097         struct cifs_tcon *tcon;
2098
2099         tcon = cifs_find_tcon(ses, ctx);
2100         if (tcon) {
2101                 /*
2102                  * tcon has refcount already incremented but we need to
2103                  * decrement extra ses reference gotten by caller (case b)
2104                  */
2105                 cifs_dbg(FYI, "Found match on UNC path\n");
2106                 cifs_put_smb_ses(ses);
2107                 return tcon;
2108         }
2109
2110         if (!ses->server->ops->tree_connect) {
2111                 rc = -ENOSYS;
2112                 goto out_fail;
2113         }
2114
2115         tcon = tconInfoAlloc();
2116         if (tcon == NULL) {
2117                 rc = -ENOMEM;
2118                 goto out_fail;
2119         }
2120
2121         if (ctx->snapshot_time) {
2122                 if (ses->server->vals->protocol_id == 0) {
2123                         cifs_dbg(VFS,
2124                              "Use SMB2 or later for snapshot mount option\n");
2125                         rc = -EOPNOTSUPP;
2126                         goto out_fail;
2127                 } else
2128                         tcon->snapshot_time = ctx->snapshot_time;
2129         }
2130
2131         if (ctx->handle_timeout) {
2132                 if (ses->server->vals->protocol_id == 0) {
2133                         cifs_dbg(VFS,
2134                              "Use SMB2.1 or later for handle timeout option\n");
2135                         rc = -EOPNOTSUPP;
2136                         goto out_fail;
2137                 } else
2138                         tcon->handle_timeout = ctx->handle_timeout;
2139         }
2140
2141         tcon->ses = ses;
2142         if (ctx->password) {
2143                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2144                 if (!tcon->password) {
2145                         rc = -ENOMEM;
2146                         goto out_fail;
2147                 }
2148         }
2149
2150         if (ctx->seal) {
2151                 if (ses->server->vals->protocol_id == 0) {
2152                         cifs_dbg(VFS,
2153                                  "SMB3 or later required for encryption\n");
2154                         rc = -EOPNOTSUPP;
2155                         goto out_fail;
2156                 } else if (tcon->ses->server->capabilities &
2157                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2158                         tcon->seal = true;
2159                 else {
2160                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2161                         rc = -EOPNOTSUPP;
2162                         goto out_fail;
2163                 }
2164         }
2165
2166         if (ctx->linux_ext) {
2167                 if (ses->server->posix_ext_supported) {
2168                         tcon->posix_extensions = true;
2169                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2170                 } else {
2171                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2172                         rc = -EOPNOTSUPP;
2173                         goto out_fail;
2174                 }
2175         }
2176
2177         /*
2178          * BB Do we need to wrap session_mutex around this TCon call and Unix
2179          * SetFS as we do on SessSetup and reconnect?
2180          */
2181         xid = get_xid();
2182         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2183                                             ctx->local_nls);
2184         free_xid(xid);
2185         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2186         if (rc)
2187                 goto out_fail;
2188
2189         tcon->use_persistent = false;
2190         /* check if SMB2 or later, CIFS does not support persistent handles */
2191         if (ctx->persistent) {
2192                 if (ses->server->vals->protocol_id == 0) {
2193                         cifs_dbg(VFS,
2194                              "SMB3 or later required for persistent handles\n");
2195                         rc = -EOPNOTSUPP;
2196                         goto out_fail;
2197                 } else if (ses->server->capabilities &
2198                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2199                         tcon->use_persistent = true;
2200                 else /* persistent handles requested but not supported */ {
2201                         cifs_dbg(VFS,
2202                                 "Persistent handles not supported on share\n");
2203                         rc = -EOPNOTSUPP;
2204                         goto out_fail;
2205                 }
2206         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2207              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2208              && (ctx->nopersistent == false)) {
2209                 cifs_dbg(FYI, "enabling persistent handles\n");
2210                 tcon->use_persistent = true;
2211         } else if (ctx->resilient) {
2212                 if (ses->server->vals->protocol_id == 0) {
2213                         cifs_dbg(VFS,
2214                              "SMB2.1 or later required for resilient handles\n");
2215                         rc = -EOPNOTSUPP;
2216                         goto out_fail;
2217                 }
2218                 tcon->use_resilient = true;
2219         }
2220
2221         tcon->use_witness = false;
2222         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2223                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2224                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2225                                 /*
2226                                  * Set witness in use flag in first place
2227                                  * to retry registration in the echo task
2228                                  */
2229                                 tcon->use_witness = true;
2230                                 /* And try to register immediately */
2231                                 rc = cifs_swn_register(tcon);
2232                                 if (rc < 0) {
2233                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2234                                         goto out_fail;
2235                                 }
2236                         } else {
2237                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2238                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2239                                 rc = -EOPNOTSUPP;
2240                                 goto out_fail;
2241                         }
2242                 } else {
2243                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2244                         rc = -EOPNOTSUPP;
2245                         goto out_fail;
2246                 }
2247         }
2248
2249         /* If the user really knows what they are doing they can override */
2250         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2251                 if (ctx->cache_ro)
2252                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2253                 else if (ctx->cache_rw)
2254                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2255         }
2256
2257         if (ctx->no_lease) {
2258                 if (ses->server->vals->protocol_id == 0) {
2259                         cifs_dbg(VFS,
2260                                 "SMB2 or later required for nolease option\n");
2261                         rc = -EOPNOTSUPP;
2262                         goto out_fail;
2263                 } else
2264                         tcon->no_lease = ctx->no_lease;
2265         }
2266
2267         /*
2268          * We can have only one retry value for a connection to a share so for
2269          * resources mounted more than once to the same server share the last
2270          * value passed in for the retry flag is used.
2271          */
2272         tcon->retry = ctx->retry;
2273         tcon->nocase = ctx->nocase;
2274         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2275                 tcon->nohandlecache = ctx->nohandlecache;
2276         else
2277                 tcon->nohandlecache = true;
2278         tcon->nodelete = ctx->nodelete;
2279         tcon->local_lease = ctx->local_lease;
2280         INIT_LIST_HEAD(&tcon->pending_opens);
2281
2282         spin_lock(&cifs_tcp_ses_lock);
2283         list_add(&tcon->tcon_list, &ses->tcon_list);
2284         spin_unlock(&cifs_tcp_ses_lock);
2285
2286         cifs_fscache_get_super_cookie(tcon);
2287
2288         return tcon;
2289
2290 out_fail:
2291         tconInfoFree(tcon);
2292         return ERR_PTR(rc);
2293 }
2294
2295 void
2296 cifs_put_tlink(struct tcon_link *tlink)
2297 {
2298         if (!tlink || IS_ERR(tlink))
2299                 return;
2300
2301         if (!atomic_dec_and_test(&tlink->tl_count) ||
2302             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2303                 tlink->tl_time = jiffies;
2304                 return;
2305         }
2306
2307         if (!IS_ERR(tlink_tcon(tlink)))
2308                 cifs_put_tcon(tlink_tcon(tlink));
2309         kfree(tlink);
2310         return;
2311 }
2312
2313 static int
2314 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2315 {
2316         struct cifs_sb_info *old = CIFS_SB(sb);
2317         struct cifs_sb_info *new = mnt_data->cifs_sb;
2318         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2319         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2320
2321         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2322                 return 0;
2323
2324         if (old->mnt_cifs_serverino_autodisabled)
2325                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2326
2327         if (oldflags != newflags)
2328                 return 0;
2329
2330         /*
2331          * We want to share sb only if we don't specify an r/wsize or
2332          * specified r/wsize is greater than or equal to existing one.
2333          */
2334         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2335                 return 0;
2336
2337         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2338                 return 0;
2339
2340         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2341             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2342                 return 0;
2343
2344         if (old->ctx->file_mode != new->ctx->file_mode ||
2345             old->ctx->dir_mode != new->ctx->dir_mode)
2346                 return 0;
2347
2348         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2349                 return 0;
2350
2351         if (old->ctx->acregmax != new->ctx->acregmax)
2352                 return 0;
2353         if (old->ctx->acdirmax != new->ctx->acdirmax)
2354                 return 0;
2355
2356         return 1;
2357 }
2358
2359 static int
2360 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2361 {
2362         struct cifs_sb_info *old = CIFS_SB(sb);
2363         struct cifs_sb_info *new = mnt_data->cifs_sb;
2364         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2365                 old->prepath;
2366         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2367                 new->prepath;
2368
2369         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2370                 return 1;
2371         else if (!old_set && !new_set)
2372                 return 1;
2373
2374         return 0;
2375 }
2376
2377 int
2378 cifs_match_super(struct super_block *sb, void *data)
2379 {
2380         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2381         struct smb3_fs_context *ctx;
2382         struct cifs_sb_info *cifs_sb;
2383         struct TCP_Server_Info *tcp_srv;
2384         struct cifs_ses *ses;
2385         struct cifs_tcon *tcon;
2386         struct tcon_link *tlink;
2387         int rc = 0;
2388
2389         spin_lock(&cifs_tcp_ses_lock);
2390         cifs_sb = CIFS_SB(sb);
2391         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2392         if (tlink == NULL) {
2393                 /* can not match superblock if tlink were ever null */
2394                 spin_unlock(&cifs_tcp_ses_lock);
2395                 return 0;
2396         }
2397         tcon = tlink_tcon(tlink);
2398         ses = tcon->ses;
2399         tcp_srv = ses->server;
2400
2401         ctx = mnt_data->ctx;
2402
2403         if (!match_server(tcp_srv, ctx) ||
2404             !match_session(ses, ctx) ||
2405             !match_tcon(tcon, ctx) ||
2406             !match_prepath(sb, mnt_data)) {
2407                 rc = 0;
2408                 goto out;
2409         }
2410
2411         rc = compare_mount_options(sb, mnt_data);
2412 out:
2413         spin_unlock(&cifs_tcp_ses_lock);
2414         cifs_put_tlink(tlink);
2415         return rc;
2416 }
2417
2418 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2419 static struct lock_class_key cifs_key[2];
2420 static struct lock_class_key cifs_slock_key[2];
2421
2422 static inline void
2423 cifs_reclassify_socket4(struct socket *sock)
2424 {
2425         struct sock *sk = sock->sk;
2426         BUG_ON(!sock_allow_reclassification(sk));
2427         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2428                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2429 }
2430
2431 static inline void
2432 cifs_reclassify_socket6(struct socket *sock)
2433 {
2434         struct sock *sk = sock->sk;
2435         BUG_ON(!sock_allow_reclassification(sk));
2436         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2437                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2438 }
2439 #else
2440 static inline void
2441 cifs_reclassify_socket4(struct socket *sock)
2442 {
2443 }
2444
2445 static inline void
2446 cifs_reclassify_socket6(struct socket *sock)
2447 {
2448 }
2449 #endif
2450
2451 /* See RFC1001 section 14 on representation of Netbios names */
2452 static void rfc1002mangle(char *target, char *source, unsigned int length)
2453 {
2454         unsigned int i, j;
2455
2456         for (i = 0, j = 0; i < (length); i++) {
2457                 /* mask a nibble at a time and encode */
2458                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2459                 target[j+1] = 'A' + (0x0F & source[i]);
2460                 j += 2;
2461         }
2462
2463 }
2464
2465 static int
2466 bind_socket(struct TCP_Server_Info *server)
2467 {
2468         int rc = 0;
2469         if (server->srcaddr.ss_family != AF_UNSPEC) {
2470                 /* Bind to the specified local IP address */
2471                 struct socket *socket = server->ssocket;
2472                 rc = socket->ops->bind(socket,
2473                                        (struct sockaddr *) &server->srcaddr,
2474                                        sizeof(server->srcaddr));
2475                 if (rc < 0) {
2476                         struct sockaddr_in *saddr4;
2477                         struct sockaddr_in6 *saddr6;
2478                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2479                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2480                         if (saddr6->sin6_family == AF_INET6)
2481                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2482                                          &saddr6->sin6_addr, rc);
2483                         else
2484                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2485                                          &saddr4->sin_addr.s_addr, rc);
2486                 }
2487         }
2488         return rc;
2489 }
2490
2491 static int
2492 ip_rfc1001_connect(struct TCP_Server_Info *server)
2493 {
2494         int rc = 0;
2495         /*
2496          * some servers require RFC1001 sessinit before sending
2497          * negprot - BB check reconnection in case where second
2498          * sessinit is sent but no second negprot
2499          */
2500         struct rfc1002_session_packet *ses_init_buf;
2501         struct smb_hdr *smb_buf;
2502         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2503                                GFP_KERNEL);
2504         if (ses_init_buf) {
2505                 ses_init_buf->trailer.session_req.called_len = 32;
2506
2507                 if (server->server_RFC1001_name[0] != 0)
2508                         rfc1002mangle(ses_init_buf->trailer.
2509                                       session_req.called_name,
2510                                       server->server_RFC1001_name,
2511                                       RFC1001_NAME_LEN_WITH_NULL);
2512                 else
2513                         rfc1002mangle(ses_init_buf->trailer.
2514                                       session_req.called_name,
2515                                       DEFAULT_CIFS_CALLED_NAME,
2516                                       RFC1001_NAME_LEN_WITH_NULL);
2517
2518                 ses_init_buf->trailer.session_req.calling_len = 32;
2519
2520                 /*
2521                  * calling name ends in null (byte 16) from old smb
2522                  * convention.
2523                  */
2524                 if (server->workstation_RFC1001_name[0] != 0)
2525                         rfc1002mangle(ses_init_buf->trailer.
2526                                       session_req.calling_name,
2527                                       server->workstation_RFC1001_name,
2528                                       RFC1001_NAME_LEN_WITH_NULL);
2529                 else
2530                         rfc1002mangle(ses_init_buf->trailer.
2531                                       session_req.calling_name,
2532                                       "LINUX_CIFS_CLNT",
2533                                       RFC1001_NAME_LEN_WITH_NULL);
2534
2535                 ses_init_buf->trailer.session_req.scope1 = 0;
2536                 ses_init_buf->trailer.session_req.scope2 = 0;
2537                 smb_buf = (struct smb_hdr *)ses_init_buf;
2538
2539                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2540                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2541                 rc = smb_send(server, smb_buf, 0x44);
2542                 kfree(ses_init_buf);
2543                 /*
2544                  * RFC1001 layer in at least one server
2545                  * requires very short break before negprot
2546                  * presumably because not expecting negprot
2547                  * to follow so fast.  This is a simple
2548                  * solution that works without
2549                  * complicating the code and causes no
2550                  * significant slowing down on mount
2551                  * for everyone else
2552                  */
2553                 usleep_range(1000, 2000);
2554         }
2555         /*
2556          * else the negprot may still work without this
2557          * even though malloc failed
2558          */
2559
2560         return rc;
2561 }
2562
2563 static int
2564 generic_ip_connect(struct TCP_Server_Info *server)
2565 {
2566         int rc = 0;
2567         __be16 sport;
2568         int slen, sfamily;
2569         struct socket *socket = server->ssocket;
2570         struct sockaddr *saddr;
2571
2572         saddr = (struct sockaddr *) &server->dstaddr;
2573
2574         if (server->dstaddr.ss_family == AF_INET6) {
2575                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2576
2577                 sport = ipv6->sin6_port;
2578                 slen = sizeof(struct sockaddr_in6);
2579                 sfamily = AF_INET6;
2580                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2581                                 ntohs(sport));
2582         } else {
2583                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2584
2585                 sport = ipv4->sin_port;
2586                 slen = sizeof(struct sockaddr_in);
2587                 sfamily = AF_INET;
2588                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2589                                 ntohs(sport));
2590         }
2591
2592         if (socket == NULL) {
2593                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2594                                    IPPROTO_TCP, &socket, 1);
2595                 if (rc < 0) {
2596                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2597                         server->ssocket = NULL;
2598                         return rc;
2599                 }
2600
2601                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2602                 cifs_dbg(FYI, "Socket created\n");
2603                 server->ssocket = socket;
2604                 socket->sk->sk_allocation = GFP_NOFS;
2605                 if (sfamily == AF_INET6)
2606                         cifs_reclassify_socket6(socket);
2607                 else
2608                         cifs_reclassify_socket4(socket);
2609         }
2610
2611         rc = bind_socket(server);
2612         if (rc < 0)
2613                 return rc;
2614
2615         /*
2616          * Eventually check for other socket options to change from
2617          * the default. sock_setsockopt not used because it expects
2618          * user space buffer
2619          */
2620         socket->sk->sk_rcvtimeo = 7 * HZ;
2621         socket->sk->sk_sndtimeo = 5 * HZ;
2622
2623         /* make the bufsizes depend on wsize/rsize and max requests */
2624         if (server->noautotune) {
2625                 if (socket->sk->sk_sndbuf < (200 * 1024))
2626                         socket->sk->sk_sndbuf = 200 * 1024;
2627                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2628                         socket->sk->sk_rcvbuf = 140 * 1024;
2629         }
2630
2631         if (server->tcp_nodelay)
2632                 tcp_sock_set_nodelay(socket->sk);
2633
2634         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2635                  socket->sk->sk_sndbuf,
2636                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2637
2638         rc = socket->ops->connect(socket, saddr, slen,
2639                                   server->noblockcnt ? O_NONBLOCK : 0);
2640         /*
2641          * When mounting SMB root file systems, we do not want to block in
2642          * connect. Otherwise bail out and then let cifs_reconnect() perform
2643          * reconnect failover - if possible.
2644          */
2645         if (server->noblockcnt && rc == -EINPROGRESS)
2646                 rc = 0;
2647         if (rc < 0) {
2648                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2649                 sock_release(socket);
2650                 server->ssocket = NULL;
2651                 return rc;
2652         }
2653
2654         if (sport == htons(RFC1001_PORT))
2655                 rc = ip_rfc1001_connect(server);
2656
2657         return rc;
2658 }
2659
2660 static int
2661 ip_connect(struct TCP_Server_Info *server)
2662 {
2663         __be16 *sport;
2664         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2665         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2666
2667         if (server->dstaddr.ss_family == AF_INET6)
2668                 sport = &addr6->sin6_port;
2669         else
2670                 sport = &addr->sin_port;
2671
2672         if (*sport == 0) {
2673                 int rc;
2674
2675                 /* try with 445 port at first */
2676                 *sport = htons(CIFS_PORT);
2677
2678                 rc = generic_ip_connect(server);
2679                 if (rc >= 0)
2680                         return rc;
2681
2682                 /* if it failed, try with 139 port */
2683                 *sport = htons(RFC1001_PORT);
2684         }
2685
2686         return generic_ip_connect(server);
2687 }
2688
2689 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2690                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2691 {
2692         /*
2693          * If we are reconnecting then should we check to see if
2694          * any requested capabilities changed locally e.g. via
2695          * remount but we can not do much about it here
2696          * if they have (even if we could detect it by the following)
2697          * Perhaps we could add a backpointer to array of sb from tcon
2698          * or if we change to make all sb to same share the same
2699          * sb as NFS - then we only have one backpointer to sb.
2700          * What if we wanted to mount the server share twice once with
2701          * and once without posixacls or posix paths?
2702          */
2703         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2704
2705         if (ctx && ctx->no_linux_ext) {
2706                 tcon->fsUnixInfo.Capability = 0;
2707                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2708                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2709                 return;
2710         } else if (ctx)
2711                 tcon->unix_ext = 1; /* Unix Extensions supported */
2712
2713         if (!tcon->unix_ext) {
2714                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2715                 return;
2716         }
2717
2718         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2719                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2720                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2721                 /*
2722                  * check for reconnect case in which we do not
2723                  * want to change the mount behavior if we can avoid it
2724                  */
2725                 if (ctx == NULL) {
2726                         /*
2727                          * turn off POSIX ACL and PATHNAMES if not set
2728                          * originally at mount time
2729                          */
2730                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2731                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2732                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2733                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2734                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2735                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2736                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2737                                 cifs_dbg(VFS, "possible reconnect error\n");
2738                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2739                         }
2740                 }
2741
2742                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2743                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2744
2745                 cap &= CIFS_UNIX_CAP_MASK;
2746                 if (ctx && ctx->no_psx_acl)
2747                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2748                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2749                         cifs_dbg(FYI, "negotiated posix acl support\n");
2750                         if (cifs_sb)
2751                                 cifs_sb->mnt_cifs_flags |=
2752                                         CIFS_MOUNT_POSIXACL;
2753                 }
2754
2755                 if (ctx && ctx->posix_paths == 0)
2756                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2757                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2758                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2759                         if (cifs_sb)
2760                                 cifs_sb->mnt_cifs_flags |=
2761                                         CIFS_MOUNT_POSIX_PATHS;
2762                 }
2763
2764                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
2765 #ifdef CONFIG_CIFS_DEBUG2
2766                 if (cap & CIFS_UNIX_FCNTL_CAP)
2767                         cifs_dbg(FYI, "FCNTL cap\n");
2768                 if (cap & CIFS_UNIX_EXTATTR_CAP)
2769                         cifs_dbg(FYI, "EXTATTR cap\n");
2770                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2771                         cifs_dbg(FYI, "POSIX path cap\n");
2772                 if (cap & CIFS_UNIX_XATTR_CAP)
2773                         cifs_dbg(FYI, "XATTR cap\n");
2774                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
2775                         cifs_dbg(FYI, "POSIX ACL cap\n");
2776                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
2777                         cifs_dbg(FYI, "very large read cap\n");
2778                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
2779                         cifs_dbg(FYI, "very large write cap\n");
2780                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
2781                         cifs_dbg(FYI, "transport encryption cap\n");
2782                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2783                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
2784 #endif /* CIFS_DEBUG2 */
2785                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
2786                         if (ctx == NULL)
2787                                 cifs_dbg(FYI, "resetting capabilities failed\n");
2788                         else
2789                                 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");
2790
2791                 }
2792         }
2793 }
2794
2795 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
2796 {
2797         struct smb3_fs_context *ctx = cifs_sb->ctx;
2798
2799         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
2800
2801         spin_lock_init(&cifs_sb->tlink_tree_lock);
2802         cifs_sb->tlink_tree = RB_ROOT;
2803
2804         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
2805                  ctx->file_mode, ctx->dir_mode);
2806
2807         /* this is needed for ASCII cp to Unicode converts */
2808         if (ctx->iocharset == NULL) {
2809                 /* load_nls_default cannot return null */
2810                 cifs_sb->local_nls = load_nls_default();
2811         } else {
2812                 cifs_sb->local_nls = load_nls(ctx->iocharset);
2813                 if (cifs_sb->local_nls == NULL) {
2814                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
2815                                  ctx->iocharset);
2816                         return -ELIBACC;
2817                 }
2818         }
2819         ctx->local_nls = cifs_sb->local_nls;
2820
2821         smb3_update_mnt_flags(cifs_sb);
2822
2823         if (ctx->direct_io)
2824                 cifs_dbg(FYI, "mounting share using direct i/o\n");
2825         if (ctx->cache_ro) {
2826                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
2827                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
2828         } else if (ctx->cache_rw) {
2829                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
2830                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
2831                                             CIFS_MOUNT_RW_CACHE);
2832         }
2833
2834         if ((ctx->cifs_acl) && (ctx->dynperm))
2835                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
2836
2837         if (ctx->prepath) {
2838                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
2839                 if (cifs_sb->prepath == NULL)
2840                         return -ENOMEM;
2841                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
2842         }
2843
2844         return 0;
2845 }
2846
2847 /* Release all succeed connections */
2848 static inline void mount_put_conns(struct cifs_sb_info *cifs_sb,
2849                                    unsigned int xid,
2850                                    struct TCP_Server_Info *server,
2851                                    struct cifs_ses *ses, struct cifs_tcon *tcon)
2852 {
2853         int rc = 0;
2854
2855         if (tcon)
2856                 cifs_put_tcon(tcon);
2857         else if (ses)
2858                 cifs_put_smb_ses(ses);
2859         else if (server)
2860                 cifs_put_tcp_session(server, 0);
2861         cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
2862         free_xid(xid);
2863 }
2864
2865 /* Get connections for tcp, ses and tcon */
2866 static int mount_get_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
2867                            unsigned int *xid,
2868                            struct TCP_Server_Info **nserver,
2869                            struct cifs_ses **nses, struct cifs_tcon **ntcon)
2870 {
2871         int rc = 0;
2872         struct TCP_Server_Info *server;
2873         struct cifs_ses *ses;
2874         struct cifs_tcon *tcon;
2875
2876         *nserver = NULL;
2877         *nses = NULL;
2878         *ntcon = NULL;
2879
2880         *xid = get_xid();
2881
2882         /* get a reference to a tcp session */
2883         server = cifs_get_tcp_session(ctx);
2884         if (IS_ERR(server)) {
2885                 rc = PTR_ERR(server);
2886                 return rc;
2887         }
2888
2889         *nserver = server;
2890
2891         /* get a reference to a SMB session */
2892         ses = cifs_get_smb_ses(server, ctx);
2893         if (IS_ERR(ses)) {
2894                 rc = PTR_ERR(ses);
2895                 return rc;
2896         }
2897
2898         *nses = ses;
2899
2900         if ((ctx->persistent == true) && (!(ses->server->capabilities &
2901                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
2902                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
2903                 return -EOPNOTSUPP;
2904         }
2905
2906         /* search for existing tcon to this server share */
2907         tcon = cifs_get_tcon(ses, ctx);
2908         if (IS_ERR(tcon)) {
2909                 rc = PTR_ERR(tcon);
2910                 return rc;
2911         }
2912
2913         *ntcon = tcon;
2914
2915         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
2916         if (tcon->posix_extensions)
2917                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
2918
2919         /* tell server which Unix caps we support */
2920         if (cap_unix(tcon->ses)) {
2921                 /*
2922                  * reset of caps checks mount to see if unix extensions disabled
2923                  * for just this mount.
2924                  */
2925                 reset_cifs_unix_caps(*xid, tcon, cifs_sb, ctx);
2926                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
2927                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
2928                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP))
2929                         return -EACCES;
2930         } else
2931                 tcon->unix_ext = 0; /* server does not support them */
2932
2933         /* do not care if a following call succeed - informational */
2934         if (!tcon->pipe && server->ops->qfs_tcon) {
2935                 server->ops->qfs_tcon(*xid, tcon, cifs_sb);
2936                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
2937                         if (tcon->fsDevInfo.DeviceCharacteristics &
2938                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
2939                                 cifs_dbg(VFS, "mounted to read only share\n");
2940                         else if ((cifs_sb->mnt_cifs_flags &
2941                                   CIFS_MOUNT_RW_CACHE) == 0)
2942                                 cifs_dbg(VFS, "read only mount of RW share\n");
2943                         /* no need to log a RW mount of a typical RW share */
2944                 }
2945         }
2946
2947         /*
2948          * Clamp the rsize/wsize mount arguments if they are too big for the server
2949          * and set the rsize/wsize to the negotiated values if not passed in by
2950          * the user on mount
2951          */
2952         if ((cifs_sb->ctx->wsize == 0) ||
2953             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
2954                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
2955         if ((cifs_sb->ctx->rsize == 0) ||
2956             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
2957                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
2958
2959         return 0;
2960 }
2961
2962 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
2963                              struct cifs_tcon *tcon)
2964 {
2965         struct tcon_link *tlink;
2966
2967         /* hang the tcon off of the superblock */
2968         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
2969         if (tlink == NULL)
2970                 return -ENOMEM;
2971
2972         tlink->tl_uid = ses->linux_uid;
2973         tlink->tl_tcon = tcon;
2974         tlink->tl_time = jiffies;
2975         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
2976         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
2977
2978         cifs_sb->master_tlink = tlink;
2979         spin_lock(&cifs_sb->tlink_tree_lock);
2980         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
2981         spin_unlock(&cifs_sb->tlink_tree_lock);
2982
2983         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
2984                                 TLINK_IDLE_EXPIRE);
2985         return 0;
2986 }
2987
2988 #ifdef CONFIG_CIFS_DFS_UPCALL
2989 static int mount_get_dfs_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
2990                                unsigned int *xid, struct TCP_Server_Info **nserver,
2991                                struct cifs_ses **nses, struct cifs_tcon **ntcon)
2992 {
2993         int rc;
2994
2995         ctx->nosharesock = true;
2996         rc = mount_get_conns(ctx, cifs_sb, xid, nserver, nses, ntcon);
2997         if (*nserver) {
2998                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
2999                 spin_lock(&cifs_tcp_ses_lock);
3000                 (*nserver)->is_dfs_conn = true;
3001                 spin_unlock(&cifs_tcp_ses_lock);
3002         }
3003         return rc;
3004 }
3005
3006 /*
3007  * cifs_build_path_to_root returns full path to root when we do not have an
3008  * existing connection (tcon)
3009  */
3010 static char *
3011 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3012                        const struct cifs_sb_info *cifs_sb, bool useppath)
3013 {
3014         char *full_path, *pos;
3015         unsigned int pplen = useppath && ctx->prepath ?
3016                 strlen(ctx->prepath) + 1 : 0;
3017         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3018
3019         if (unc_len > MAX_TREE_SIZE)
3020                 return ERR_PTR(-EINVAL);
3021
3022         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3023         if (full_path == NULL)
3024                 return ERR_PTR(-ENOMEM);
3025
3026         memcpy(full_path, ctx->UNC, unc_len);
3027         pos = full_path + unc_len;
3028
3029         if (pplen) {
3030                 *pos = CIFS_DIR_SEP(cifs_sb);
3031                 memcpy(pos + 1, ctx->prepath, pplen);
3032                 pos += pplen;
3033         }
3034
3035         *pos = '\0'; /* add trailing null */
3036         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3037         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3038         return full_path;
3039 }
3040
3041 /*
3042  * expand_dfs_referral - Perform a dfs referral query and update the cifs_sb
3043  *
3044  * If a referral is found, cifs_sb->ctx->mount_options will be (re-)allocated
3045  * to a string containing updated options for the submount.  Otherwise it
3046  * will be left untouched.
3047  *
3048  * Returns the rc from get_dfs_path to the caller, which can be used to
3049  * determine whether there were referrals.
3050  */
3051 static int
3052 expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
3053                     struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
3054                     char *ref_path)
3055 {
3056         int rc;
3057         struct dfs_info3_param referral = {0};
3058         char *full_path = NULL, *mdata = NULL;
3059
3060         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
3061                 return -EREMOTE;
3062
3063         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3064         if (IS_ERR(full_path))
3065                 return PTR_ERR(full_path);
3066
3067         rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3068                             ref_path, &referral, NULL);
3069         if (!rc) {
3070                 char *fake_devname = NULL;
3071
3072                 mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options,
3073                                                    full_path + 1, &referral,
3074                                                    &fake_devname);
3075                 free_dfs_info_param(&referral);
3076
3077                 if (IS_ERR(mdata)) {
3078                         rc = PTR_ERR(mdata);
3079                         mdata = NULL;
3080                 } else {
3081                         /*
3082                          * We can not clear out the whole structure since we
3083                          * no longer have an explicit function to parse
3084                          * a mount-string. Instead we need to clear out the
3085                          * individual fields that are no longer valid.
3086                          */
3087                         kfree(ctx->prepath);
3088                         ctx->prepath = NULL;
3089                         rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3090                 }
3091                 kfree(fake_devname);
3092                 kfree(cifs_sb->ctx->mount_options);
3093                 cifs_sb->ctx->mount_options = mdata;
3094         }
3095         kfree(full_path);
3096         return rc;
3097 }
3098
3099 static int get_next_dfs_tgt(struct dfs_cache_tgt_list *tgt_list,
3100                             struct dfs_cache_tgt_iterator **tgt_it)
3101 {
3102         if (!*tgt_it)
3103                 *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
3104         else
3105                 *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it);
3106         return !*tgt_it ? -EHOSTDOWN : 0;
3107 }
3108
3109 static int update_vol_info(const struct dfs_cache_tgt_iterator *tgt_it,
3110                            struct smb3_fs_context *fake_ctx, struct smb3_fs_context *ctx)
3111 {
3112         const char *tgt = dfs_cache_get_tgt_name(tgt_it);
3113         int len = strlen(tgt) + 2;
3114         char *new_unc;
3115
3116         new_unc = kmalloc(len, GFP_KERNEL);
3117         if (!new_unc)
3118                 return -ENOMEM;
3119         scnprintf(new_unc, len, "\\%s", tgt);
3120
3121         kfree(ctx->UNC);
3122         ctx->UNC = new_unc;
3123
3124         if (fake_ctx->prepath) {
3125                 kfree(ctx->prepath);
3126                 ctx->prepath = fake_ctx->prepath;
3127                 fake_ctx->prepath = NULL;
3128         }
3129         memcpy(&ctx->dstaddr, &fake_ctx->dstaddr, sizeof(ctx->dstaddr));
3130
3131         return 0;
3132 }
3133
3134 static int do_dfs_failover(const char *path, const char *full_path, struct cifs_sb_info *cifs_sb,
3135                            struct smb3_fs_context *ctx, struct cifs_ses *root_ses,
3136                            unsigned int *xid, struct TCP_Server_Info **server,
3137                            struct cifs_ses **ses, struct cifs_tcon **tcon)
3138 {
3139         int rc;
3140         char *npath = NULL;
3141         struct dfs_cache_tgt_list tgt_list = DFS_CACHE_TGT_LIST_INIT(tgt_list);
3142         struct dfs_cache_tgt_iterator *tgt_it = NULL;
3143         struct smb3_fs_context tmp_ctx = {NULL};
3144
3145         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
3146                 return -EOPNOTSUPP;
3147
3148         npath = dfs_cache_canonical_path(path, cifs_sb->local_nls, cifs_remap(cifs_sb));
3149         if (IS_ERR(npath))
3150                 return PTR_ERR(npath);
3151
3152         cifs_dbg(FYI, "%s: path=%s full_path=%s\n", __func__, npath, full_path);
3153
3154         rc = dfs_cache_noreq_find(npath, NULL, &tgt_list);
3155         if (rc)
3156                 goto out;
3157         /*
3158          * We use a 'tmp_ctx' here because we need pass it down to the mount_{get,put} functions to
3159          * test connection against new DFS targets.
3160          */
3161         rc = smb3_fs_context_dup(&tmp_ctx, ctx);
3162         if (rc)
3163                 goto out;
3164
3165         for (;;) {
3166                 struct dfs_info3_param ref = {0};
3167                 char *fake_devname = NULL, *mdata = NULL;
3168
3169                 /* Get next DFS target server - if any */
3170                 rc = get_next_dfs_tgt(&tgt_list, &tgt_it);
3171                 if (rc)
3172                         break;
3173
3174                 rc = dfs_cache_get_tgt_referral(npath, tgt_it, &ref);
3175                 if (rc)
3176                         break;
3177
3178                 cifs_dbg(FYI, "%s: old ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3179                          tmp_ctx.prepath);
3180
3181                 mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, &ref,
3182                                                    &fake_devname);
3183                 free_dfs_info_param(&ref);
3184
3185                 if (IS_ERR(mdata)) {
3186                         rc = PTR_ERR(mdata);
3187                         mdata = NULL;
3188                 } else
3189                         rc = cifs_setup_volume_info(&tmp_ctx, mdata, fake_devname);
3190
3191                 kfree(mdata);
3192                 kfree(fake_devname);
3193
3194                 if (rc)
3195                         break;
3196
3197                 cifs_dbg(FYI, "%s: new ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3198                          tmp_ctx.prepath);
3199
3200                 mount_put_conns(cifs_sb, *xid, *server, *ses, *tcon);
3201                 rc = mount_get_dfs_conns(&tmp_ctx, cifs_sb, xid, server, ses, tcon);
3202                 if (!rc || (*server && *ses)) {
3203                         /*
3204                          * We were able to connect to new target server. Update current context with
3205                          * new target server.
3206                          */
3207                         rc = update_vol_info(tgt_it, &tmp_ctx, ctx);
3208                         break;
3209                 }
3210         }
3211         if (!rc) {
3212                 cifs_dbg(FYI, "%s: final ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3213                          tmp_ctx.prepath);
3214                 /*
3215                  * Update DFS target hint in DFS referral cache with the target server we
3216                  * successfully reconnected to.
3217                  */
3218                 rc = dfs_cache_update_tgthint(*xid, root_ses ? root_ses : *ses, cifs_sb->local_nls,
3219                                               cifs_remap(cifs_sb), path, tgt_it);
3220         }
3221
3222 out:
3223         kfree(npath);
3224         smb3_cleanup_fs_context_contents(&tmp_ctx);
3225         dfs_cache_free_tgts(&tgt_list);
3226         return rc;
3227 }
3228 #endif
3229
3230 /* TODO: all callers to this are broken. We are not parsing mount_options here
3231  * we should pass a clone of the original context?
3232  */
3233 int
3234 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3235 {
3236         int rc;
3237
3238         if (devname) {
3239                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3240                 rc = smb3_parse_devname(devname, ctx);
3241                 if (rc) {
3242                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3243                         return rc;
3244                 }
3245         }
3246
3247         if (mntopts) {
3248                 char *ip;
3249
3250                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3251                 if (rc) {
3252                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3253                         return rc;
3254                 }
3255
3256                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3257                 kfree(ip);
3258                 if (!rc) {
3259                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3260                         return -EINVAL;
3261                 }
3262         }
3263
3264         if (ctx->nullauth) {
3265                 cifs_dbg(FYI, "Anonymous login\n");
3266                 kfree(ctx->username);
3267                 ctx->username = NULL;
3268         } else if (ctx->username) {
3269                 /* BB fixme parse for domain name here */
3270                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3271         } else {
3272                 cifs_dbg(VFS, "No username specified\n");
3273         /* In userspace mount helper we can get user name from alternate
3274            locations such as env variables and files on disk */
3275                 return -EINVAL;
3276         }
3277
3278         return 0;
3279 }
3280
3281 static int
3282 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3283                                         unsigned int xid,
3284                                         struct cifs_tcon *tcon,
3285                                         struct cifs_sb_info *cifs_sb,
3286                                         char *full_path,
3287                                         int added_treename)
3288 {
3289         int rc;
3290         char *s;
3291         char sep, tmp;
3292         int skip = added_treename ? 1 : 0;
3293
3294         sep = CIFS_DIR_SEP(cifs_sb);
3295         s = full_path;
3296
3297         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3298         while (rc == 0) {
3299                 /* skip separators */
3300                 while (*s == sep)
3301                         s++;
3302                 if (!*s)
3303                         break;
3304                 /* next separator */
3305                 while (*s && *s != sep)
3306                         s++;
3307                 /*
3308                  * if the treename is added, we then have to skip the first
3309                  * part within the separators
3310                  */
3311                 if (skip) {
3312                         skip = 0;
3313                         continue;
3314                 }
3315                 /*
3316                  * temporarily null-terminate the path at the end of
3317                  * the current component
3318                  */
3319                 tmp = *s;
3320                 *s = 0;
3321                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3322                                                      full_path);
3323                 *s = tmp;
3324         }
3325         return rc;
3326 }
3327
3328 /*
3329  * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
3330  * otherwise 0.
3331  */
3332 static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx,
3333                           const unsigned int xid,
3334                           struct TCP_Server_Info *server,
3335                           struct cifs_tcon *tcon)
3336 {
3337         int rc;
3338         char *full_path;
3339
3340         if (!server->ops->is_path_accessible)
3341                 return -EOPNOTSUPP;
3342
3343         /*
3344          * cifs_build_path_to_root works only when we have a valid tcon
3345          */
3346         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3347                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3348         if (full_path == NULL)
3349                 return -ENOMEM;
3350
3351         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3352
3353         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3354                                              full_path);
3355         if (rc != 0 && rc != -EREMOTE) {
3356                 kfree(full_path);
3357                 return rc;
3358         }
3359
3360         if (rc != -EREMOTE) {
3361                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3362                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3363                 if (rc != 0) {
3364                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3365                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3366                         rc = 0;
3367                 }
3368         }
3369
3370         kfree(full_path);
3371         return rc;
3372 }
3373
3374 #ifdef CONFIG_CIFS_DFS_UPCALL
3375 static void set_root_ses(struct cifs_sb_info *cifs_sb, const uuid_t *mount_id, struct cifs_ses *ses,
3376                          struct cifs_ses **root_ses)
3377 {
3378         if (ses) {
3379                 spin_lock(&cifs_tcp_ses_lock);
3380                 ses->ses_count++;
3381                 spin_unlock(&cifs_tcp_ses_lock);
3382                 dfs_cache_add_refsrv_session(mount_id, ses);
3383         }
3384         *root_ses = ses;
3385 }
3386
3387 /* Set up next dfs prefix path in @dfs_path */
3388 static int next_dfs_prepath(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx,
3389                             const unsigned int xid, struct TCP_Server_Info *server,
3390                             struct cifs_tcon *tcon, char **dfs_path)
3391 {
3392         char *path, *npath;
3393         int added_treename = is_tcon_dfs(tcon);
3394         int rc;
3395
3396         path = cifs_build_path_to_root(ctx, cifs_sb, tcon, added_treename);
3397         if (!path)
3398                 return -ENOMEM;
3399
3400         rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3401         if (rc == -EREMOTE) {
3402                 struct smb3_fs_context v = {NULL};
3403                 /* if @path contains a tree name, skip it in the prefix path */
3404                 if (added_treename) {
3405                         rc = smb3_parse_devname(path, &v);
3406                         if (rc)
3407                                 goto out;
3408                         npath = build_unc_path_to_root(&v, cifs_sb, true);
3409                         smb3_cleanup_fs_context_contents(&v);
3410                 } else {
3411                         v.UNC = ctx->UNC;
3412                         v.prepath = path + 1;
3413                         npath = build_unc_path_to_root(&v, cifs_sb, true);
3414                 }
3415
3416                 if (IS_ERR(npath)) {
3417                         rc = PTR_ERR(npath);
3418                         goto out;
3419                 }
3420
3421                 kfree(*dfs_path);
3422                 *dfs_path = npath;
3423                 rc = -EREMOTE;
3424         }
3425
3426 out:
3427         kfree(path);
3428         return rc;
3429 }
3430
3431 /* Check if resolved targets can handle any DFS referrals */
3432 static int is_referral_server(const char *ref_path, struct cifs_sb_info *cifs_sb,
3433                               struct cifs_tcon *tcon, bool *ref_server)
3434 {
3435         int rc;
3436         struct dfs_info3_param ref = {0};
3437
3438         cifs_dbg(FYI, "%s: ref_path=%s\n", __func__, ref_path);
3439
3440         if (is_tcon_dfs(tcon)) {
3441                 *ref_server = true;
3442         } else {
3443                 char *npath;
3444
3445                 npath = dfs_cache_canonical_path(ref_path, cifs_sb->local_nls, cifs_remap(cifs_sb));
3446                 if (IS_ERR(npath))
3447                         return PTR_ERR(npath);
3448
3449                 rc = dfs_cache_noreq_find(npath, &ref, NULL);
3450                 kfree(npath);
3451                 if (rc) {
3452                         cifs_dbg(VFS, "%s: dfs_cache_noreq_find: failed (rc=%d)\n", __func__, rc);
3453                         return rc;
3454                 }
3455                 cifs_dbg(FYI, "%s: ref.flags=0x%x\n", __func__, ref.flags);
3456                 /*
3457                  * Check if all targets are capable of handling DFS referrals as per
3458                  * MS-DFSC 2.2.4 RESP_GET_DFS_REFERRAL.
3459                  */
3460                 *ref_server = !!(ref.flags & DFSREF_REFERRAL_SERVER);
3461                 free_dfs_info_param(&ref);
3462         }
3463         return 0;
3464 }
3465
3466 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3467 {
3468         int rc = 0;
3469         unsigned int xid;
3470         struct TCP_Server_Info *server = NULL;
3471         struct cifs_ses *ses = NULL, *root_ses = NULL;
3472         struct cifs_tcon *tcon = NULL;
3473         int count = 0;
3474         uuid_t mount_id = {0};
3475         char *ref_path = NULL, *full_path = NULL;
3476         char *oldmnt = NULL;
3477         bool ref_server = false;
3478
3479         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3480         /*
3481          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3482          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3483          *
3484          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3485          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3486          */
3487         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3488             dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), ctx->UNC + 1, NULL,
3489                            NULL)) {
3490                 if (rc)
3491                         goto error;
3492                 /* Check if it is fully accessible and then mount it */
3493                 rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3494                 if (!rc)
3495                         goto out;
3496                 if (rc != -EREMOTE)
3497                         goto error;
3498         }
3499
3500         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3501         /*
3502          * Ignore error check here because we may failover to other targets from cached a
3503          * referral.
3504          */
3505         (void)mount_get_dfs_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3506
3507         /* Get path of DFS root */
3508         ref_path = build_unc_path_to_root(ctx, cifs_sb, false);
3509         if (IS_ERR(ref_path)) {
3510                 rc = PTR_ERR(ref_path);
3511                 ref_path = NULL;
3512                 goto error;
3513         }
3514
3515         uuid_gen(&mount_id);
3516         set_root_ses(cifs_sb, &mount_id, ses, &root_ses);
3517         do {
3518                 /* Save full path of last DFS path we used to resolve final target server */
3519                 kfree(full_path);
3520                 full_path = build_unc_path_to_root(ctx, cifs_sb, !!count);
3521                 if (IS_ERR(full_path)) {
3522                         rc = PTR_ERR(full_path);
3523                         full_path = NULL;
3524                         break;
3525                 }
3526                 /* Chase referral */
3527                 oldmnt = cifs_sb->ctx->mount_options;
3528                 rc = expand_dfs_referral(xid, root_ses, ctx, cifs_sb, ref_path + 1);
3529                 if (rc)
3530                         break;
3531                 /* Connect to new DFS target only if we were redirected */
3532                 if (oldmnt != cifs_sb->ctx->mount_options) {
3533                         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3534                         rc = mount_get_dfs_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3535                 }
3536                 if (rc && !server && !ses) {
3537                         /* Failed to connect. Try to connect to other targets in the referral. */
3538                         rc = do_dfs_failover(ref_path + 1, full_path, cifs_sb, ctx, root_ses, &xid,
3539                                              &server, &ses, &tcon);
3540                 }
3541                 if (rc == -EACCES || rc == -EOPNOTSUPP || !server || !ses)
3542                         break;
3543                 if (!tcon)
3544                         continue;
3545
3546                 /* Make sure that requests go through new root servers */
3547                 rc = is_referral_server(ref_path + 1, cifs_sb, tcon, &ref_server);
3548                 if (rc)
3549                         break;
3550                 if (ref_server)
3551                         set_root_ses(cifs_sb, &mount_id, ses, &root_ses);
3552
3553                 /* Get next dfs path and then continue chasing them if -EREMOTE */
3554                 rc = next_dfs_prepath(cifs_sb, ctx, xid, server, tcon, &ref_path);
3555                 /* Prevent recursion on broken link referrals */
3556                 if (rc == -EREMOTE && ++count > MAX_NESTED_LINKS)
3557                         rc = -ELOOP;
3558         } while (rc == -EREMOTE);
3559
3560         if (rc || !tcon || !ses)
3561                 goto error;
3562
3563         kfree(ref_path);
3564         /*
3565          * Store DFS full path in both superblock and tree connect structures.
3566          *
3567          * For DFS root mounts, the prefix path (cifs_sb->prepath) is preserved during reconnect so
3568          * only the root path is set in cifs_sb->origin_fullpath and tcon->dfs_path. And for DFS
3569          * links, the prefix path is included in both and may be changed during reconnect.  See
3570          * cifs_tree_connect().
3571          */
3572         ref_path = dfs_cache_canonical_path(full_path, cifs_sb->local_nls, cifs_remap(cifs_sb));
3573         kfree(full_path);
3574         full_path = NULL;
3575
3576         if (IS_ERR(ref_path)) {
3577                 rc = PTR_ERR(ref_path);
3578                 ref_path = NULL;
3579                 goto error;
3580         }
3581         cifs_sb->origin_fullpath = ref_path;
3582
3583         ref_path = kstrdup(cifs_sb->origin_fullpath, GFP_KERNEL);
3584         if (!ref_path) {
3585                 rc = -ENOMEM;
3586                 goto error;
3587         }
3588         spin_lock(&cifs_tcp_ses_lock);
3589         tcon->dfs_path = ref_path;
3590         ref_path = NULL;
3591         spin_unlock(&cifs_tcp_ses_lock);
3592
3593         /*
3594          * After reconnecting to a different server, unique ids won't
3595          * match anymore, so we disable serverino. This prevents
3596          * dentry revalidation to think the dentry are stale (ESTALE).
3597          */
3598         cifs_autodisable_serverino(cifs_sb);
3599         /*
3600          * Force the use of prefix path to support failover on DFS paths that
3601          * resolve to targets that have different prefix paths.
3602          */
3603         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3604         kfree(cifs_sb->prepath);
3605         cifs_sb->prepath = ctx->prepath;
3606         ctx->prepath = NULL;
3607         uuid_copy(&cifs_sb->dfs_mount_id, &mount_id);
3608
3609 out:
3610         free_xid(xid);
3611         cifs_try_adding_channels(cifs_sb, ses);
3612         return mount_setup_tlink(cifs_sb, ses, tcon);
3613
3614 error:
3615         kfree(ref_path);
3616         kfree(full_path);
3617         kfree(cifs_sb->origin_fullpath);
3618         dfs_cache_put_refsrv_sessions(&mount_id);
3619         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3620         return rc;
3621 }
3622 #else
3623 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3624 {
3625         int rc = 0;
3626         unsigned int xid;
3627         struct cifs_ses *ses;
3628         struct cifs_tcon *tcon;
3629         struct TCP_Server_Info *server;
3630
3631         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3632         if (rc)
3633                 goto error;
3634
3635         if (tcon) {
3636                 rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3637                 if (rc == -EREMOTE)
3638                         rc = -EOPNOTSUPP;
3639                 if (rc)
3640                         goto error;
3641         }
3642
3643         free_xid(xid);
3644
3645         return mount_setup_tlink(cifs_sb, ses, tcon);
3646
3647 error:
3648         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3649         return rc;
3650 }
3651 #endif
3652
3653 /*
3654  * Issue a TREE_CONNECT request.
3655  */
3656 int
3657 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3658          const char *tree, struct cifs_tcon *tcon,
3659          const struct nls_table *nls_codepage)
3660 {
3661         struct smb_hdr *smb_buffer;
3662         struct smb_hdr *smb_buffer_response;
3663         TCONX_REQ *pSMB;
3664         TCONX_RSP *pSMBr;
3665         unsigned char *bcc_ptr;
3666         int rc = 0;
3667         int length;
3668         __u16 bytes_left, count;
3669
3670         if (ses == NULL)
3671                 return -EIO;
3672
3673         smb_buffer = cifs_buf_get();
3674         if (smb_buffer == NULL)
3675                 return -ENOMEM;
3676
3677         smb_buffer_response = smb_buffer;
3678
3679         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3680                         NULL /*no tid */ , 4 /*wct */ );
3681
3682         smb_buffer->Mid = get_next_mid(ses->server);
3683         smb_buffer->Uid = ses->Suid;
3684         pSMB = (TCONX_REQ *) smb_buffer;
3685         pSMBr = (TCONX_RSP *) smb_buffer_response;
3686
3687         pSMB->AndXCommand = 0xFF;
3688         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3689         bcc_ptr = &pSMB->Password[0];
3690         if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
3691                 pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3692                 *bcc_ptr = 0; /* password is null byte */
3693                 bcc_ptr++;              /* skip password */
3694                 /* already aligned so no need to do it below */
3695         }
3696
3697         if (ses->server->sign)
3698                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3699
3700         if (ses->capabilities & CAP_STATUS32) {
3701                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3702         }
3703         if (ses->capabilities & CAP_DFS) {
3704                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3705         }
3706         if (ses->capabilities & CAP_UNICODE) {
3707                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3708                 length =
3709                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3710                         6 /* max utf8 char length in bytes */ *
3711                         (/* server len*/ + 256 /* share len */), nls_codepage);
3712                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3713                 bcc_ptr += 2;   /* skip trailing null */
3714         } else {                /* ASCII */
3715                 strcpy(bcc_ptr, tree);
3716                 bcc_ptr += strlen(tree) + 1;
3717         }
3718         strcpy(bcc_ptr, "?????");
3719         bcc_ptr += strlen("?????");
3720         bcc_ptr += 1;
3721         count = bcc_ptr - &pSMB->Password[0];
3722         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3723         pSMB->ByteCount = cpu_to_le16(count);
3724
3725         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3726                          0);
3727
3728         /* above now done in SendReceive */
3729         if (rc == 0) {
3730                 bool is_unicode;
3731
3732                 tcon->tidStatus = CifsGood;
3733                 tcon->need_reconnect = false;
3734                 tcon->tid = smb_buffer_response->Tid;
3735                 bcc_ptr = pByteArea(smb_buffer_response);
3736                 bytes_left = get_bcc(smb_buffer_response);
3737                 length = strnlen(bcc_ptr, bytes_left - 2);
3738                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3739                         is_unicode = true;
3740                 else
3741                         is_unicode = false;
3742
3743
3744                 /* skip service field (NB: this field is always ASCII) */
3745                 if (length == 3) {
3746                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3747                             (bcc_ptr[2] == 'C')) {
3748                                 cifs_dbg(FYI, "IPC connection\n");
3749                                 tcon->ipc = true;
3750                                 tcon->pipe = true;
3751                         }
3752                 } else if (length == 2) {
3753                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3754                                 /* the most common case */
3755                                 cifs_dbg(FYI, "disk share connection\n");
3756                         }
3757                 }
3758                 bcc_ptr += length + 1;
3759                 bytes_left -= (length + 1);
3760                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3761
3762                 /* mostly informational -- no need to fail on error here */
3763                 kfree(tcon->nativeFileSystem);
3764                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3765                                                       bytes_left, is_unicode,
3766                                                       nls_codepage);
3767
3768                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3769
3770                 if ((smb_buffer_response->WordCount == 3) ||
3771                          (smb_buffer_response->WordCount == 7))
3772                         /* field is in same location */
3773                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3774                 else
3775                         tcon->Flags = 0;
3776                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3777         }
3778
3779         cifs_buf_release(smb_buffer);
3780         return rc;
3781 }
3782
3783 static void delayed_free(struct rcu_head *p)
3784 {
3785         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3786
3787         unload_nls(cifs_sb->local_nls);
3788         smb3_cleanup_fs_context(cifs_sb->ctx);
3789         kfree(cifs_sb);
3790 }
3791
3792 void
3793 cifs_umount(struct cifs_sb_info *cifs_sb)
3794 {
3795         struct rb_root *root = &cifs_sb->tlink_tree;
3796         struct rb_node *node;
3797         struct tcon_link *tlink;
3798
3799         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3800
3801         spin_lock(&cifs_sb->tlink_tree_lock);
3802         while ((node = rb_first(root))) {
3803                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3804                 cifs_get_tlink(tlink);
3805                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3806                 rb_erase(node, root);
3807
3808                 spin_unlock(&cifs_sb->tlink_tree_lock);
3809                 cifs_put_tlink(tlink);
3810                 spin_lock(&cifs_sb->tlink_tree_lock);
3811         }
3812         spin_unlock(&cifs_sb->tlink_tree_lock);
3813
3814         kfree(cifs_sb->prepath);
3815 #ifdef CONFIG_CIFS_DFS_UPCALL
3816         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3817         kfree(cifs_sb->origin_fullpath);
3818 #endif
3819         call_rcu(&cifs_sb->rcu, delayed_free);
3820 }
3821
3822 int
3823 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses)
3824 {
3825         int rc = 0;
3826         struct TCP_Server_Info *server = cifs_ses_server(ses);
3827
3828         if (!server->ops->need_neg || !server->ops->negotiate)
3829                 return -ENOSYS;
3830
3831         /* only send once per connect */
3832         if (!server->ops->need_neg(server))
3833                 return 0;
3834
3835         rc = server->ops->negotiate(xid, ses);
3836         if (rc == 0) {
3837                 spin_lock(&GlobalMid_Lock);
3838                 if (server->tcpStatus == CifsNeedNegotiate)
3839                         server->tcpStatus = CifsGood;
3840                 else
3841                         rc = -EHOSTDOWN;
3842                 spin_unlock(&GlobalMid_Lock);
3843         }
3844
3845         return rc;
3846 }
3847
3848 int
3849 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3850                    struct nls_table *nls_info)
3851 {
3852         int rc = -ENOSYS;
3853         struct TCP_Server_Info *server = cifs_ses_server(ses);
3854
3855         if (!ses->binding) {
3856                 ses->capabilities = server->capabilities;
3857                 if (!linuxExtEnabled)
3858                         ses->capabilities &= (~server->vals->cap_unix);
3859
3860                 if (ses->auth_key.response) {
3861                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3862                                  ses->auth_key.response);
3863                         kfree(ses->auth_key.response);
3864                         ses->auth_key.response = NULL;
3865                         ses->auth_key.len = 0;
3866                 }
3867         }
3868
3869         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3870                  server->sec_mode, server->capabilities, server->timeAdj);
3871
3872         if (server->ops->sess_setup)
3873                 rc = server->ops->sess_setup(xid, ses, nls_info);
3874
3875         if (rc)
3876                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3877
3878         return rc;
3879 }
3880
3881 static int
3882 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3883 {
3884         ctx->sectype = ses->sectype;
3885
3886         /* krb5 is special, since we don't need username or pw */
3887         if (ctx->sectype == Kerberos)
3888                 return 0;
3889
3890         return cifs_set_cifscreds(ctx, ses);
3891 }
3892
3893 static struct cifs_tcon *
3894 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3895 {
3896         int rc;
3897         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3898         struct cifs_ses *ses;
3899         struct cifs_tcon *tcon = NULL;
3900         struct smb3_fs_context *ctx;
3901
3902         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3903         if (ctx == NULL)
3904                 return ERR_PTR(-ENOMEM);
3905
3906         ctx->local_nls = cifs_sb->local_nls;
3907         ctx->linux_uid = fsuid;
3908         ctx->cred_uid = fsuid;
3909         ctx->UNC = master_tcon->treeName;
3910         ctx->retry = master_tcon->retry;
3911         ctx->nocase = master_tcon->nocase;
3912         ctx->nohandlecache = master_tcon->nohandlecache;
3913         ctx->local_lease = master_tcon->local_lease;
3914         ctx->no_lease = master_tcon->no_lease;
3915         ctx->resilient = master_tcon->use_resilient;
3916         ctx->persistent = master_tcon->use_persistent;
3917         ctx->handle_timeout = master_tcon->handle_timeout;
3918         ctx->no_linux_ext = !master_tcon->unix_ext;
3919         ctx->linux_ext = master_tcon->posix_extensions;
3920         ctx->sectype = master_tcon->ses->sectype;
3921         ctx->sign = master_tcon->ses->sign;
3922         ctx->seal = master_tcon->seal;
3923         ctx->witness = master_tcon->use_witness;
3924
3925         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3926         if (rc) {
3927                 tcon = ERR_PTR(rc);
3928                 goto out;
3929         }
3930
3931         /* get a reference for the same TCP session */
3932         spin_lock(&cifs_tcp_ses_lock);
3933         ++master_tcon->ses->server->srv_count;
3934         spin_unlock(&cifs_tcp_ses_lock);
3935
3936         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3937         if (IS_ERR(ses)) {
3938                 tcon = (struct cifs_tcon *)ses;
3939                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3940                 goto out;
3941         }
3942
3943         tcon = cifs_get_tcon(ses, ctx);
3944         if (IS_ERR(tcon)) {
3945                 cifs_put_smb_ses(ses);
3946                 goto out;
3947         }
3948
3949         if (cap_unix(ses))
3950                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3951
3952 out:
3953         kfree(ctx->username);
3954         kfree_sensitive(ctx->password);
3955         kfree(ctx);
3956
3957         return tcon;
3958 }
3959
3960 struct cifs_tcon *
3961 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3962 {
3963         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3964 }
3965
3966 /* find and return a tlink with given uid */
3967 static struct tcon_link *
3968 tlink_rb_search(struct rb_root *root, kuid_t uid)
3969 {
3970         struct rb_node *node = root->rb_node;
3971         struct tcon_link *tlink;
3972
3973         while (node) {
3974                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3975
3976                 if (uid_gt(tlink->tl_uid, uid))
3977                         node = node->rb_left;
3978                 else if (uid_lt(tlink->tl_uid, uid))
3979                         node = node->rb_right;
3980                 else
3981                         return tlink;
3982         }
3983         return NULL;
3984 }
3985
3986 /* insert a tcon_link into the tree */
3987 static void
3988 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3989 {
3990         struct rb_node **new = &(root->rb_node), *parent = NULL;
3991         struct tcon_link *tlink;
3992
3993         while (*new) {
3994                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3995                 parent = *new;
3996
3997                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3998                         new = &((*new)->rb_left);
3999                 else
4000                         new = &((*new)->rb_right);
4001         }
4002
4003         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4004         rb_insert_color(&new_tlink->tl_rbnode, root);
4005 }
4006
4007 /*
4008  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4009  * current task.
4010  *
4011  * If the superblock doesn't refer to a multiuser mount, then just return
4012  * the master tcon for the mount.
4013  *
4014  * First, search the rbtree for an existing tcon for this fsuid. If one
4015  * exists, then check to see if it's pending construction. If it is then wait
4016  * for construction to complete. Once it's no longer pending, check to see if
4017  * it failed and either return an error or retry construction, depending on
4018  * the timeout.
4019  *
4020  * If one doesn't exist then insert a new tcon_link struct into the tree and
4021  * try to construct a new one.
4022  */
4023 struct tcon_link *
4024 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4025 {
4026         int ret;
4027         kuid_t fsuid = current_fsuid();
4028         struct tcon_link *tlink, *newtlink;
4029
4030         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4031                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4032
4033         spin_lock(&cifs_sb->tlink_tree_lock);
4034         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4035         if (tlink)
4036                 cifs_get_tlink(tlink);
4037         spin_unlock(&cifs_sb->tlink_tree_lock);
4038
4039         if (tlink == NULL) {
4040                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4041                 if (newtlink == NULL)
4042                         return ERR_PTR(-ENOMEM);
4043                 newtlink->tl_uid = fsuid;
4044                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4045                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4046                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4047                 cifs_get_tlink(newtlink);
4048
4049                 spin_lock(&cifs_sb->tlink_tree_lock);
4050                 /* was one inserted after previous search? */
4051                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4052                 if (tlink) {
4053                         cifs_get_tlink(tlink);
4054                         spin_unlock(&cifs_sb->tlink_tree_lock);
4055                         kfree(newtlink);
4056                         goto wait_for_construction;
4057                 }
4058                 tlink = newtlink;
4059                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4060                 spin_unlock(&cifs_sb->tlink_tree_lock);
4061         } else {
4062 wait_for_construction:
4063                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4064                                   TASK_INTERRUPTIBLE);
4065                 if (ret) {
4066                         cifs_put_tlink(tlink);
4067                         return ERR_PTR(-ERESTARTSYS);
4068                 }
4069
4070                 /* if it's good, return it */
4071                 if (!IS_ERR(tlink->tl_tcon))
4072                         return tlink;
4073
4074                 /* return error if we tried this already recently */
4075                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4076                         cifs_put_tlink(tlink);
4077                         return ERR_PTR(-EACCES);
4078                 }
4079
4080                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4081                         goto wait_for_construction;
4082         }
4083
4084         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4085         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4086         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4087
4088         if (IS_ERR(tlink->tl_tcon)) {
4089                 cifs_put_tlink(tlink);
4090                 return ERR_PTR(-EACCES);
4091         }
4092
4093         return tlink;
4094 }
4095
4096 /*
4097  * periodic workqueue job that scans tcon_tree for a superblock and closes
4098  * out tcons.
4099  */
4100 static void
4101 cifs_prune_tlinks(struct work_struct *work)
4102 {
4103         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4104                                                     prune_tlinks.work);
4105         struct rb_root *root = &cifs_sb->tlink_tree;
4106         struct rb_node *node;
4107         struct rb_node *tmp;
4108         struct tcon_link *tlink;
4109
4110         /*
4111          * Because we drop the spinlock in the loop in order to put the tlink
4112          * it's not guarded against removal of links from the tree. The only
4113          * places that remove entries from the tree are this function and
4114          * umounts. Because this function is non-reentrant and is canceled
4115          * before umount can proceed, this is safe.
4116          */
4117         spin_lock(&cifs_sb->tlink_tree_lock);
4118         node = rb_first(root);
4119         while (node != NULL) {
4120                 tmp = node;
4121                 node = rb_next(tmp);
4122                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4123
4124                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4125                     atomic_read(&tlink->tl_count) != 0 ||
4126                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4127                         continue;
4128
4129                 cifs_get_tlink(tlink);
4130                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4131                 rb_erase(tmp, root);
4132
4133                 spin_unlock(&cifs_sb->tlink_tree_lock);
4134                 cifs_put_tlink(tlink);
4135                 spin_lock(&cifs_sb->tlink_tree_lock);
4136         }
4137         spin_unlock(&cifs_sb->tlink_tree_lock);
4138
4139         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4140                                 TLINK_IDLE_EXPIRE);
4141 }
4142
4143 #ifdef CONFIG_CIFS_DFS_UPCALL
4144 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4145 {
4146         int rc;
4147         struct TCP_Server_Info *server = tcon->ses->server;
4148         const struct smb_version_operations *ops = server->ops;
4149         struct dfs_cache_tgt_list tl;
4150         struct dfs_cache_tgt_iterator *it = NULL;
4151         char *tree;
4152         const char *tcp_host;
4153         size_t tcp_host_len;
4154         const char *dfs_host;
4155         size_t dfs_host_len;
4156         char *share = NULL, *prefix = NULL;
4157         struct dfs_info3_param ref = {0};
4158         bool isroot;
4159
4160         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4161         if (!tree)
4162                 return -ENOMEM;
4163
4164         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4165         if (!tcon->dfs_path || dfs_cache_noreq_find(tcon->dfs_path + 1, &ref, &tl)) {
4166                 if (tcon->ipc) {
4167                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4168                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4169                 } else {
4170                         rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4171                 }
4172                 goto out;
4173         }
4174
4175         isroot = ref.server_type == DFS_TYPE_ROOT;
4176         free_dfs_info_param(&ref);
4177
4178         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4179
4180         for (it = dfs_cache_get_tgt_iterator(&tl); it; it = dfs_cache_get_next_tgt(&tl, it)) {
4181                 bool target_match;
4182
4183                 kfree(share);
4184                 kfree(prefix);
4185                 share = NULL;
4186                 prefix = NULL;
4187
4188                 rc = dfs_cache_get_tgt_share(tcon->dfs_path + 1, it, &share, &prefix);
4189                 if (rc) {
4190                         cifs_dbg(VFS, "%s: failed to parse target share %d\n",
4191                                  __func__, rc);
4192                         continue;
4193                 }
4194
4195                 extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4196
4197                 if (dfs_host_len != tcp_host_len
4198                     || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4199                         cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4200                                  dfs_host, (int)tcp_host_len, tcp_host);
4201
4202                         rc = match_target_ip(server, dfs_host, dfs_host_len, &target_match);
4203                         if (rc) {
4204                                 cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4205                                 break;
4206                         }
4207
4208                         if (!target_match) {
4209                                 cifs_dbg(FYI, "%s: skipping target\n", __func__);
4210                                 continue;
4211                         }
4212                 }
4213
4214                 if (tcon->ipc) {
4215                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", share);
4216                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4217                 } else {
4218                         scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4219                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4220                         /* Only handle prefix paths of DFS link targets */
4221                         if (!rc && !isroot) {
4222                                 rc = update_super_prepath(tcon, prefix);
4223                                 break;
4224                         }
4225                 }
4226                 if (rc == -EREMOTE)
4227                         break;
4228         }
4229
4230         kfree(share);
4231         kfree(prefix);
4232
4233         if (!rc) {
4234                 if (it)
4235                         rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1, it);
4236                 else
4237                         rc = -ENOENT;
4238         }
4239         dfs_cache_free_tgts(&tl);
4240 out:
4241         kfree(tree);
4242         return rc;
4243 }
4244 #else
4245 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4246 {
4247         const struct smb_version_operations *ops = tcon->ses->server->ops;
4248
4249         return ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4250 }
4251 #endif