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 struct mount_ctx {
  65         struct cifs_sb_info *cifs_sb;
  66         struct smb3_fs_context *fs_ctx;
  67         unsigned int xid;
  68         struct TCP_Server_Info *server;
  69         struct cifs_ses *ses;
  70         struct cifs_tcon *tcon;
  71 #ifdef CONFIG_CIFS_DFS_UPCALL
  72         struct cifs_ses *root_ses;
  73         uuid_t mount_id;
  74         char *origin_fullpath, *leaf_fullpath;
  75 #endif
  76 };
  77
  78 static int ip_connect(struct TCP_Server_Info *server);
  79 static int generic_ip_connect(struct TCP_Server_Info *server);
  80 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  81 static void cifs_prune_tlinks(struct work_struct *work);
  82
  83 /*
  84  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  85  * get their ip addresses changed at some point.
  86  *
  87  * This should be called with server->srv_mutex held.
  88  */
  89 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  90 {
  91         int rc;
  92         int len;
  93         char *unc, *ipaddr = NULL;
  94         time64_t expiry, now;
  95         unsigned long ttl = SMB_DNS_RESOLVE_INTERVAL_DEFAULT;
  96
  97         if (!server->hostname)
  98                 return -EINVAL;
  99
 100         len = strlen(server->hostname) + 3;
 101
 102         unc = kmalloc(len, GFP_KERNEL);
 103         if (!unc) {
 104                 cifs_dbg(FYI, "%s: failed to create UNC path\n", __func__);
 105                 return -ENOMEM;
 106         }
 107         scnprintf(unc, len, "\\\\%s", server->hostname);
 108
 109         rc = dns_resolve_server_name_to_ip(unc, &ipaddr, &expiry);
 110         kfree(unc);
 111
 112         if (rc < 0) {
 113                 cifs_dbg(FYI, "%s: failed to resolve server part of %s to IP: %d\n",
 114                          __func__, server->hostname, rc);
 115                 goto requeue_resolve;
 116         }
 117
 118         spin_lock(&cifs_tcp_ses_lock);
 119         rc = cifs_convert_address((struct sockaddr *)&server->dstaddr, ipaddr,
 120                                   strlen(ipaddr));
 121         spin_unlock(&cifs_tcp_ses_lock);
 122         kfree(ipaddr);
 123
 124         /* rc == 1 means success here */
 125         if (rc) {
 126                 now = ktime_get_real_seconds();
 127                 if (expiry && expiry > now)
 128                         /*
 129                          * To make sure we don't use the cached entry, retry 1s
 130                          * after expiry.
 131                          */
 132                         ttl = max_t(unsigned long, expiry - now, SMB_DNS_RESOLVE_INTERVAL_MIN) + 1;
 133         }
 134         rc = !rc ? -1 : 0;
 135
 136 requeue_resolve:
 137         cifs_dbg(FYI, "%s: next dns resolution scheduled for %lu seconds in the future\n",
 138                  __func__, ttl);
 139         mod_delayed_work(cifsiod_wq, &server->resolve, (ttl * HZ));
 140
 141         return rc;
 142 }
 143
 144
 145 static void cifs_resolve_server(struct work_struct *work)
 146 {
 147         int rc;
 148         struct TCP_Server_Info *server = container_of(work,
 149                                         struct TCP_Server_Info, resolve.work);
 150
 151         mutex_lock(&server->srv_mutex);
 152
 153         /*
 154          * Resolve the hostname again to make sure that IP address is up-to-date.
 155          */
 156         rc = reconn_set_ipaddr_from_hostname(server);
 157         if (rc) {
 158                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 159                                 __func__, rc);
 160         }
 161
 162         mutex_unlock(&server->srv_mutex);
 163 }
 164
 165 /*
 166  * Mark all sessions and tcons for reconnect.
 167  *
 168  * @server needs to be previously set to CifsNeedReconnect.
 169  *
 170  */
 171 void
 172 cifs_mark_tcp_ses_conns_for_reconnect(struct TCP_Server_Info *server,
 173                                       bool mark_smb_session)
 174 {
 175         struct TCP_Server_Info *pserver;
 176         struct cifs_ses *ses;
 177         struct cifs_tcon *tcon;
 178
 179         /*
 180          * before reconnecting the tcp session, mark the smb session (uid) and the tid bad so they
 181          * are not used until reconnected.
 182          */
 183         cifs_dbg(FYI, "%s: marking necessary sessions and tcons for reconnect\n", __func__);
 184
 185         /* If server is a channel, select the primary channel */
 186         pserver = CIFS_SERVER_IS_CHAN(server) ? server->primary_server : server;
 187
 188
 189         spin_lock(&cifs_tcp_ses_lock);
 190         list_for_each_entry(ses, &pserver->smb_ses_list, smb_ses_list) {
 191                 spin_lock(&ses->chan_lock);
 192                 if (!mark_smb_session && cifs_chan_needs_reconnect(ses, server))
 193                         goto next_session;
 194
 195                 if (mark_smb_session)
 196                         CIFS_SET_ALL_CHANS_NEED_RECONNECT(ses);
 197                 else
 198                         cifs_chan_set_need_reconnect(ses, server);
 199
 200                 /* If all channels need reconnect, then tcon needs reconnect */
 201                 if (!mark_smb_session && !CIFS_ALL_CHANS_NEED_RECONNECT(ses))
 202                         goto next_session;
 203
 204                 ses->status = CifsNeedReconnect;
 205
 206                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 207                         tcon->need_reconnect = true;
 208                         tcon->tidStatus = CifsNeedReconnect;
 209                 }
 210                 if (ses->tcon_ipc)
 211                         ses->tcon_ipc->need_reconnect = true;
 212
 213 next_session:
 214                 spin_unlock(&ses->chan_lock);
 215         }
 216         spin_unlock(&cifs_tcp_ses_lock);
 217 }
 218
 219 static void
 220 cifs_abort_connection(struct TCP_Server_Info *server)
 221 {
 222         struct mid_q_entry *mid, *nmid;
 223         struct list_head retry_list;
 224
 225         server->maxBuf = 0;
 226         server->max_read = 0;
 227
 228         /* do not want to be sending data on a socket we are freeing */
 229         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 230         mutex_lock(&server->srv_mutex);
 231         if (server->ssocket) {
 232                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 233                          server->ssocket->flags);
 234                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 235                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n", server->ssocket->state,
 236                          server->ssocket->flags);
 237                 sock_release(server->ssocket);
 238                 server->ssocket = NULL;
 239         }
 240         server->sequence_number = 0;
 241         server->session_estab = false;
 242         kfree(server->session_key.response);
 243         server->session_key.response = NULL;
 244         server->session_key.len = 0;
 245         server->lstrp = jiffies;
 246
 247         /* mark submitted MIDs for retry and issue callback */
 248         INIT_LIST_HEAD(&retry_list);
 249         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 250         spin_lock(&GlobalMid_Lock);
 251         list_for_each_entry_safe(mid, nmid, &server->pending_mid_q, qhead) {
 252                 kref_get(&mid->refcount);
 253                 if (mid->mid_state == MID_REQUEST_SUBMITTED)
 254                         mid->mid_state = MID_RETRY_NEEDED;
 255                 list_move(&mid->qhead, &retry_list);
 256                 mid->mid_flags |= MID_DELETED;
 257         }
 258         spin_unlock(&GlobalMid_Lock);
 259         mutex_unlock(&server->srv_mutex);
 260
 261         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 262         list_for_each_entry_safe(mid, nmid, &retry_list, qhead) {
 263                 list_del_init(&mid->qhead);
 264                 mid->callback(mid);
 265                 cifs_mid_q_entry_release(mid);
 266         }
 267
 268         if (cifs_rdma_enabled(server)) {
 269                 mutex_lock(&server->srv_mutex);
 270                 smbd_destroy(server);
 271                 mutex_unlock(&server->srv_mutex);
 272         }
 273 }
 274
 275 static bool cifs_tcp_ses_needs_reconnect(struct TCP_Server_Info *server, int num_targets)
 276 {
 277         spin_lock(&cifs_tcp_ses_lock);
 278         server->nr_targets = num_targets;
 279         if (server->tcpStatus == CifsExiting) {
 280                 /* the demux thread will exit normally next time through the loop */
 281                 spin_unlock(&cifs_tcp_ses_lock);
 282                 wake_up(&server->response_q);
 283                 return false;
 284         }
 285
 286         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 287         trace_smb3_reconnect(server->CurrentMid, server->conn_id,
 288                              server->hostname);
 289         server->tcpStatus = CifsNeedReconnect;
 290
 291         spin_unlock(&cifs_tcp_ses_lock);
 292         return true;
 293 }
 294
 295 /*
 296  * cifs tcp session reconnection
 297  *
 298  * mark tcp session as reconnecting so temporarily locked
 299  * mark all smb sessions as reconnecting for tcp session
 300  * reconnect tcp session
 301  * wake up waiters on reconnection? - (not needed currently)
 302  *
 303  * if mark_smb_session is passed as true, unconditionally mark
 304  * the smb session (and tcon) for reconnect as well. This value
 305  * doesn't really matter for non-multichannel scenario.
 306  *
 307  */
 308 static int __cifs_reconnect(struct TCP_Server_Info *server,
 309                             bool mark_smb_session)
 310 {
 311         int rc = 0;
 312
 313         if (!cifs_tcp_ses_needs_reconnect(server, 1))
 314                 return 0;
 315
 316         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 317
 318         cifs_abort_connection(server);
 319
 320         do {
 321                 try_to_freeze();
 322                 mutex_lock(&server->srv_mutex);
 323
 324                 if (!cifs_swn_set_server_dstaddr(server)) {
 325                         /* resolve the hostname again to make sure that IP address is up-to-date */
 326                         rc = reconn_set_ipaddr_from_hostname(server);
 327                         cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 328                 }
 329
 330                 if (cifs_rdma_enabled(server))
 331                         rc = smbd_reconnect(server);
 332                 else
 333                         rc = generic_ip_connect(server);
 334                 if (rc) {
 335                         mutex_unlock(&server->srv_mutex);
 336                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 337                         msleep(3000);
 338                 } else {
 339                         atomic_inc(&tcpSesReconnectCount);
 340                         set_credits(server, 1);
 341                         spin_lock(&cifs_tcp_ses_lock);
 342                         if (server->tcpStatus != CifsExiting)
 343                                 server->tcpStatus = CifsNeedNegotiate;
 344                         spin_unlock(&cifs_tcp_ses_lock);
 345                         cifs_swn_reset_server_dstaddr(server);
 346                         mutex_unlock(&server->srv_mutex);
 347                         mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 348                 }
 349         } while (server->tcpStatus == CifsNeedReconnect);
 350
 351         spin_lock(&cifs_tcp_ses_lock);
 352         if (server->tcpStatus == CifsNeedNegotiate)
 353                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 354         spin_unlock(&cifs_tcp_ses_lock);
 355
 356         wake_up(&server->response_q);
 357         return rc;
 358 }
 359
 360 #ifdef CONFIG_CIFS_DFS_UPCALL
 361 static int __reconnect_target_unlocked(struct TCP_Server_Info *server, const char *target)
 362 {
 363         int rc;
 364         char *hostname;
 365
 366         if (!cifs_swn_set_server_dstaddr(server)) {
 367                 if (server->hostname != target) {
 368                         hostname = extract_hostname(target);
 369                         if (!IS_ERR(hostname)) {
 370                                 kfree(server->hostname);
 371                                 server->hostname = hostname;
 372                         } else {
 373                                 cifs_dbg(FYI, "%s: couldn't extract hostname or address from dfs target: %ld\n",
 374                                          __func__, PTR_ERR(hostname));
 375                                 cifs_dbg(FYI, "%s: default to last target server: %s\n", __func__,
 376                                          server->hostname);
 377                         }
 378                 }
 379                 /* resolve the hostname again to make sure that IP address is up-to-date. */
 380                 rc = reconn_set_ipaddr_from_hostname(server);
 381                 cifs_dbg(FYI, "%s: reconn_set_ipaddr_from_hostname: rc=%d\n", __func__, rc);
 382         }
 383         /* Reconnect the socket */
 384         if (cifs_rdma_enabled(server))
 385                 rc = smbd_reconnect(server);
 386         else
 387                 rc = generic_ip_connect(server);
 388
 389         return rc;
 390 }
 391
 392 static int reconnect_target_unlocked(struct TCP_Server_Info *server, struct dfs_cache_tgt_list *tl,
 393                                      struct dfs_cache_tgt_iterator **target_hint)
 394 {
 395         int rc;
 396         struct dfs_cache_tgt_iterator *tit;
 397
 398         *target_hint = NULL;
 399
 400         /* If dfs target list is empty, then reconnect to last server */
 401         tit = dfs_cache_get_tgt_iterator(tl);
 402         if (!tit)
 403                 return __reconnect_target_unlocked(server, server->hostname);
 404
 405         /* Otherwise, try every dfs target in @tl */
 406         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
 407                 rc = __reconnect_target_unlocked(server, dfs_cache_get_tgt_name(tit));
 408                 if (!rc) {
 409                         *target_hint = tit;
 410                         break;
 411                 }
 412         }
 413         return rc;
 414 }
 415
 416 static int
 417 reconnect_dfs_server(struct TCP_Server_Info *server,
 418                      bool mark_smb_session)
 419 {
 420         int rc = 0;
 421         const char *refpath = server->current_fullpath + 1;
 422         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
 423         struct dfs_cache_tgt_iterator *target_hint = NULL;
 424         int num_targets = 0;
 425
 426         /*
 427          * Determine the number of dfs targets the referral path in @cifs_sb resolves to.
 428          *
 429          * smb2_reconnect() needs to know how long it should wait based upon the number of dfs
 430          * targets (server->nr_targets).  It's also possible that the cached referral was cleared
 431          * through /proc/fs/cifs/dfscache or the target list is empty due to server settings after
 432          * refreshing the referral, so, in this case, default it to 1.
 433          */
 434         if (!dfs_cache_noreq_find(refpath, NULL, &tl))
 435                 num_targets = dfs_cache_get_nr_tgts(&tl);
 436         if (!num_targets)
 437                 num_targets = 1;
 438
 439         if (!cifs_tcp_ses_needs_reconnect(server, num_targets))
 440                 return 0;
 441
 442         cifs_mark_tcp_ses_conns_for_reconnect(server, mark_smb_session);
 443
 444         cifs_abort_connection(server);
 445
 446         do {
 447                 try_to_freeze();
 448                 mutex_lock(&server->srv_mutex);
 449
 450                 rc = reconnect_target_unlocked(server, &tl, &target_hint);
 451                 if (rc) {
 452                         /* Failed to reconnect socket */
 453                         mutex_unlock(&server->srv_mutex);
 454                         cifs_dbg(FYI, "%s: reconnect error %d\n", __func__, rc);
 455                         msleep(3000);
 456                         continue;
 457                 }
 458                 /*
 459                  * Socket was created.  Update tcp session status to CifsNeedNegotiate so that a
 460                  * process waiting for reconnect will know it needs to re-establish session and tcon
 461                  * through the reconnected target server.
 462                  */
 463                 atomic_inc(&tcpSesReconnectCount);
 464                 set_credits(server, 1);
 465                 spin_lock(&cifs_tcp_ses_lock);
 466                 if (server->tcpStatus != CifsExiting)
 467                         server->tcpStatus = CifsNeedNegotiate;
 468                 spin_unlock(&cifs_tcp_ses_lock);
 469                 cifs_swn_reset_server_dstaddr(server);
 470                 mutex_unlock(&server->srv_mutex);
 471                 mod_delayed_work(cifsiod_wq, &server->reconnect, 0);
 472         } while (server->tcpStatus == CifsNeedReconnect);
 473
 474         if (target_hint)
 475                 dfs_cache_noreq_update_tgthint(refpath, target_hint);
 476
 477         dfs_cache_free_tgts(&tl);
 478
 479         /* Need to set up echo worker again once connection has been established */
 480         spin_lock(&cifs_tcp_ses_lock);
 481         if (server->tcpStatus == CifsNeedNegotiate)
 482                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 483
 484         spin_unlock(&cifs_tcp_ses_lock);
 485
 486         wake_up(&server->response_q);
 487         return rc;
 488 }
 489
 490 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 491 {
 492         /* If tcp session is not an dfs connection, then reconnect to last target server */
 493         spin_lock(&cifs_tcp_ses_lock);
 494         if (!server->is_dfs_conn || !server->origin_fullpath || !server->leaf_fullpath) {
 495                 spin_unlock(&cifs_tcp_ses_lock);
 496                 return __cifs_reconnect(server, mark_smb_session);
 497         }
 498         spin_unlock(&cifs_tcp_ses_lock);
 499
 500         return reconnect_dfs_server(server, mark_smb_session);
 501 }
 502 #else
 503 int cifs_reconnect(struct TCP_Server_Info *server, bool mark_smb_session)
 504 {
 505         return __cifs_reconnect(server, mark_smb_session);
 506 }
 507 #endif
 508
 509 static void
 510 cifs_echo_request(struct work_struct *work)
 511 {
 512         int rc;
 513         struct TCP_Server_Info *server = container_of(work,
 514                                         struct TCP_Server_Info, echo.work);
 515
 516         /*
 517          * We cannot send an echo if it is disabled.
 518          * Also, no need to ping if we got a response recently.
 519          */
 520
 521         if (server->tcpStatus == CifsNeedReconnect ||
 522             server->tcpStatus == CifsExiting ||
 523             server->tcpStatus == CifsNew ||
 524             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 525             time_before(jiffies, server->lstrp + server->echo_interval - HZ))
 526                 goto requeue_echo;
 527
 528         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 529         if (rc)
 530                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 531                          server->hostname);
 532
 533         /* Check witness registrations */
 534         cifs_swn_check();
 535
 536 requeue_echo:
 537         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 538 }
 539
 540 static bool
 541 allocate_buffers(struct TCP_Server_Info *server)
 542 {
 543         if (!server->bigbuf) {
 544                 server->bigbuf = (char *)cifs_buf_get();
 545                 if (!server->bigbuf) {
 546                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 547                         msleep(3000);
 548                         /* retry will check if exiting */
 549                         return false;
 550                 }
 551         } else if (server->large_buf) {
 552                 /* we are reusing a dirty large buf, clear its start */
 553                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 554         }
 555
 556         if (!server->smallbuf) {
 557                 server->smallbuf = (char *)cifs_small_buf_get();
 558                 if (!server->smallbuf) {
 559                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 560                         msleep(1000);
 561                         /* retry will check if exiting */
 562                         return false;
 563                 }
 564                 /* beginning of smb buffer is cleared in our buf_get */
 565         } else {
 566                 /* if existing small buf clear beginning */
 567                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 568         }
 569
 570         return true;
 571 }
 572
 573 static bool
 574 server_unresponsive(struct TCP_Server_Info *server)
 575 {
 576         /*
 577          * We need to wait 3 echo intervals to make sure we handle such
 578          * situations right:
 579          * 1s  client sends a normal SMB request
 580          * 2s  client gets a response
 581          * 30s echo workqueue job pops, and decides we got a response recently
 582          *     and don't need to send another
 583          * ...
 584          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 585          *     a response in >60s.
 586          */
 587         spin_lock(&cifs_tcp_ses_lock);
 588         if ((server->tcpStatus == CifsGood ||
 589             server->tcpStatus == CifsNeedNegotiate) &&
 590             (!server->ops->can_echo || server->ops->can_echo(server)) &&
 591             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 592                 spin_unlock(&cifs_tcp_ses_lock);
 593                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 594                          (3 * server->echo_interval) / HZ);
 595                 cifs_reconnect(server, false);
 596                 return true;
 597         }
 598         spin_unlock(&cifs_tcp_ses_lock);
 599
 600         return false;
 601 }
 602
 603 static inline bool
 604 zero_credits(struct TCP_Server_Info *server)
 605 {
 606         int val;
 607
 608         spin_lock(&server->req_lock);
 609         val = server->credits + server->echo_credits + server->oplock_credits;
 610         if (server->in_flight == 0 && val == 0) {
 611                 spin_unlock(&server->req_lock);
 612                 return true;
 613         }
 614         spin_unlock(&server->req_lock);
 615         return false;
 616 }
 617
 618 static int
 619 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 620 {
 621         int length = 0;
 622         int total_read;
 623
 624         smb_msg->msg_control = NULL;
 625         smb_msg->msg_controllen = 0;
 626
 627         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 628                 try_to_freeze();
 629
 630                 /* reconnect if no credits and no requests in flight */
 631                 if (zero_credits(server)) {
 632                         cifs_reconnect(server, false);
 633                         return -ECONNABORTED;
 634                 }
 635
 636                 if (server_unresponsive(server))
 637                         return -ECONNABORTED;
 638                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 639                         length = smbd_recv(server->smbd_conn, smb_msg);
 640                 else
 641                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 642
 643                 spin_lock(&cifs_tcp_ses_lock);
 644                 if (server->tcpStatus == CifsExiting) {
 645                         spin_unlock(&cifs_tcp_ses_lock);
 646                         return -ESHUTDOWN;
 647                 }
 648
 649                 if (server->tcpStatus == CifsNeedReconnect) {
 650                         spin_unlock(&cifs_tcp_ses_lock);
 651                         cifs_reconnect(server, false);
 652                         return -ECONNABORTED;
 653                 }
 654                 spin_unlock(&cifs_tcp_ses_lock);
 655
 656                 if (length == -ERESTARTSYS ||
 657                     length == -EAGAIN ||
 658                     length == -EINTR) {
 659                         /*
 660                          * Minimum sleep to prevent looping, allowing socket
 661                          * to clear and app threads to set tcpStatus
 662                          * CifsNeedReconnect if server hung.
 663                          */
 664                         usleep_range(1000, 2000);
 665                         length = 0;
 666                         continue;
 667                 }
 668
 669                 if (length <= 0) {
 670                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 671                         cifs_reconnect(server, false);
 672                         return -ECONNABORTED;
 673                 }
 674         }
 675         return total_read;
 676 }
 677
 678 int
 679 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 680                       unsigned int to_read)
 681 {
 682         struct msghdr smb_msg;
 683         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 684         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 685
 686         return cifs_readv_from_socket(server, &smb_msg);
 687 }
 688
 689 ssize_t
 690 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 691 {
 692         struct msghdr smb_msg;
 693
 694         /*
 695          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 696          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 697          *  so little to initialize in struct msghdr
 698          */
 699         smb_msg.msg_name = NULL;
 700         smb_msg.msg_namelen = 0;
 701         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 702
 703         return cifs_readv_from_socket(server, &smb_msg);
 704 }
 705
 706 int
 707 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 708         unsigned int page_offset, unsigned int to_read)
 709 {
 710         struct msghdr smb_msg;
 711         struct bio_vec bv = {
 712                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 713         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 714         return cifs_readv_from_socket(server, &smb_msg);
 715 }
 716
 717 static bool
 718 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 719 {
 720         /*
 721          * The first byte big endian of the length field,
 722          * is actually not part of the length but the type
 723          * with the most common, zero, as regular data.
 724          */
 725         switch (type) {
 726         case RFC1002_SESSION_MESSAGE:
 727                 /* Regular SMB response */
 728                 return true;
 729         case RFC1002_SESSION_KEEP_ALIVE:
 730                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 731                 break;
 732         case RFC1002_POSITIVE_SESSION_RESPONSE:
 733                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 734                 break;
 735         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 736                 /*
 737                  * We get this from Windows 98 instead of an error on
 738                  * SMB negprot response.
 739                  */
 740                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 741                 /* give server a second to clean up */
 742                 msleep(1000);
 743                 /*
 744                  * Always try 445 first on reconnect since we get NACK
 745                  * on some if we ever connected to port 139 (the NACK
 746                  * is since we do not begin with RFC1001 session
 747                  * initialize frame).
 748                  */
 749                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 750                 cifs_reconnect(server, true);
 751                 break;
 752         default:
 753                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 754                 cifs_reconnect(server, true);
 755         }
 756
 757         return false;
 758 }
 759
 760 void
 761 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 762 {
 763 #ifdef CONFIG_CIFS_STATS2
 764         mid->when_received = jiffies;
 765 #endif
 766         spin_lock(&GlobalMid_Lock);
 767         if (!malformed)
 768                 mid->mid_state = MID_RESPONSE_RECEIVED;
 769         else
 770                 mid->mid_state = MID_RESPONSE_MALFORMED;
 771         /*
 772          * Trying to handle/dequeue a mid after the send_recv()
 773          * function has finished processing it is a bug.
 774          */
 775         if (mid->mid_flags & MID_DELETED) {
 776                 spin_unlock(&GlobalMid_Lock);
 777                 pr_warn_once("trying to dequeue a deleted mid\n");
 778         } else {
 779                 list_del_init(&mid->qhead);
 780                 mid->mid_flags |= MID_DELETED;
 781                 spin_unlock(&GlobalMid_Lock);
 782         }
 783 }
 784
 785 static unsigned int
 786 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 787 {
 788         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 789
 790         /*
 791          * SMB1 does not use credits.
 792          */
 793         if (server->vals->header_preamble_size)
 794                 return 0;
 795
 796         return le16_to_cpu(shdr->CreditRequest);
 797 }
 798
 799 static void
 800 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 801            char *buf, int malformed)
 802 {
 803         if (server->ops->check_trans2 &&
 804             server->ops->check_trans2(mid, server, buf, malformed))
 805                 return;
 806         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 807         mid->resp_buf = buf;
 808         mid->large_buf = server->large_buf;
 809         /* Was previous buf put in mpx struct for multi-rsp? */
 810         if (!mid->multiRsp) {
 811                 /* smb buffer will be freed by user thread */
 812                 if (server->large_buf)
 813                         server->bigbuf = NULL;
 814                 else
 815                         server->smallbuf = NULL;
 816         }
 817         dequeue_mid(mid, malformed);
 818 }
 819
 820 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 821 {
 822         int length;
 823
 824         /* take it off the list, if it's not already */
 825         spin_lock(&cifs_tcp_ses_lock);
 826         list_del_init(&server->tcp_ses_list);
 827         spin_unlock(&cifs_tcp_ses_lock);
 828
 829         cancel_delayed_work_sync(&server->echo);
 830         cancel_delayed_work_sync(&server->resolve);
 831
 832         spin_lock(&cifs_tcp_ses_lock);
 833         server->tcpStatus = CifsExiting;
 834         spin_unlock(&cifs_tcp_ses_lock);
 835         wake_up_all(&server->response_q);
 836
 837         /* check if we have blocked requests that need to free */
 838         spin_lock(&server->req_lock);
 839         if (server->credits <= 0)
 840                 server->credits = 1;
 841         spin_unlock(&server->req_lock);
 842         /*
 843          * Although there should not be any requests blocked on this queue it
 844          * can not hurt to be paranoid and try to wake up requests that may
 845          * haven been blocked when more than 50 at time were on the wire to the
 846          * same server - they now will see the session is in exit state and get
 847          * out of SendReceive.
 848          */
 849         wake_up_all(&server->request_q);
 850         /* give those requests time to exit */
 851         msleep(125);
 852         if (cifs_rdma_enabled(server))
 853                 smbd_destroy(server);
 854         if (server->ssocket) {
 855                 sock_release(server->ssocket);
 856                 server->ssocket = NULL;
 857         }
 858
 859         if (!list_empty(&server->pending_mid_q)) {
 860                 struct list_head dispose_list;
 861                 struct mid_q_entry *mid_entry;
 862                 struct list_head *tmp, *tmp2;
 863
 864                 INIT_LIST_HEAD(&dispose_list);
 865                 spin_lock(&GlobalMid_Lock);
 866                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 867                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 868                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 869                         kref_get(&mid_entry->refcount);
 870                         mid_entry->mid_state = MID_SHUTDOWN;
 871                         list_move(&mid_entry->qhead, &dispose_list);
 872                         mid_entry->mid_flags |= MID_DELETED;
 873                 }
 874                 spin_unlock(&GlobalMid_Lock);
 875
 876                 /* now walk dispose list and issue callbacks */
 877                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 878                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 879                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 880                         list_del_init(&mid_entry->qhead);
 881                         mid_entry->callback(mid_entry);
 882                         cifs_mid_q_entry_release(mid_entry);
 883                 }
 884                 /* 1/8th of sec is more than enough time for them to exit */
 885                 msleep(125);
 886         }
 887
 888         if (!list_empty(&server->pending_mid_q)) {
 889                 /*
 890                  * mpx threads have not exited yet give them at least the smb
 891                  * send timeout time for long ops.
 892                  *
 893                  * Due to delays on oplock break requests, we need to wait at
 894                  * least 45 seconds before giving up on a request getting a
 895                  * response and going ahead and killing cifsd.
 896                  */
 897                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 898                 msleep(46000);
 899                 /*
 900                  * If threads still have not exited they are probably never
 901                  * coming home not much else we can do but free the memory.
 902                  */
 903         }
 904
 905 #ifdef CONFIG_CIFS_DFS_UPCALL
 906         kfree(server->origin_fullpath);
 907         kfree(server->leaf_fullpath);
 908 #endif
 909         kfree(server);
 910
 911         length = atomic_dec_return(&tcpSesAllocCount);
 912         if (length > 0)
 913                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 914 }
 915
 916 static int
 917 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 918 {
 919         int length;
 920         char *buf = server->smallbuf;
 921         unsigned int pdu_length = server->pdu_size;
 922
 923         /* make sure this will fit in a large buffer */
 924         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
 925                 server->vals->header_preamble_size) {
 926                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 927                 cifs_reconnect(server, true);
 928                 return -ECONNABORTED;
 929         }
 930
 931         /* switch to large buffer if too big for a small one */
 932         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
 933                 server->large_buf = true;
 934                 memcpy(server->bigbuf, buf, server->total_read);
 935                 buf = server->bigbuf;
 936         }
 937
 938         /* now read the rest */
 939         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
 940                                        pdu_length - HEADER_SIZE(server) + 1
 941                                        + server->vals->header_preamble_size);
 942
 943         if (length < 0)
 944                 return length;
 945         server->total_read += length;
 946
 947         dump_smb(buf, server->total_read);
 948
 949         return cifs_handle_standard(server, mid);
 950 }
 951
 952 int
 953 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 954 {
 955         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
 956         int length;
 957
 958         /*
 959          * We know that we received enough to get to the MID as we
 960          * checked the pdu_length earlier. Now check to see
 961          * if the rest of the header is OK. We borrow the length
 962          * var for the rest of the loop to avoid a new stack var.
 963          *
 964          * 48 bytes is enough to display the header and a little bit
 965          * into the payload for debugging purposes.
 966          */
 967         length = server->ops->check_message(buf, server->total_read, server);
 968         if (length != 0)
 969                 cifs_dump_mem("Bad SMB: ", buf,
 970                         min_t(unsigned int, server->total_read, 48));
 971
 972         if (server->ops->is_session_expired &&
 973             server->ops->is_session_expired(buf)) {
 974                 cifs_reconnect(server, true);
 975                 return -1;
 976         }
 977
 978         if (server->ops->is_status_pending &&
 979             server->ops->is_status_pending(buf, server))
 980                 return -1;
 981
 982         if (!mid)
 983                 return length;
 984
 985         handle_mid(mid, server, buf, length);
 986         return 0;
 987 }
 988
 989 static void
 990 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 991 {
 992         struct smb2_hdr *shdr = (struct smb2_hdr *)buffer;
 993         int scredits, in_flight;
 994
 995         /*
 996          * SMB1 does not use credits.
 997          */
 998         if (server->vals->header_preamble_size)
 999                 return;
1000
1001         if (shdr->CreditRequest) {
1002                 spin_lock(&server->req_lock);
1003                 server->credits += le16_to_cpu(shdr->CreditRequest);
1004                 scredits = server->credits;
1005                 in_flight = server->in_flight;
1006                 spin_unlock(&server->req_lock);
1007                 wake_up(&server->request_q);
1008
1009                 trace_smb3_add_credits(server->CurrentMid,
1010                                 server->conn_id, server->hostname, scredits,
1011                                 le16_to_cpu(shdr->CreditRequest), in_flight);
1012                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
1013                                 __func__, le16_to_cpu(shdr->CreditRequest),
1014                                 scredits);
1015         }
1016 }
1017
1018
1019 static int
1020 cifs_demultiplex_thread(void *p)
1021 {
1022         int i, num_mids, length;
1023         struct TCP_Server_Info *server = p;
1024         unsigned int pdu_length;
1025         unsigned int next_offset;
1026         char *buf = NULL;
1027         struct task_struct *task_to_wake = NULL;
1028         struct mid_q_entry *mids[MAX_COMPOUND];
1029         char *bufs[MAX_COMPOUND];
1030         unsigned int noreclaim_flag, num_io_timeout = 0;
1031
1032         noreclaim_flag = memalloc_noreclaim_save();
1033         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
1034
1035         length = atomic_inc_return(&tcpSesAllocCount);
1036         if (length > 1)
1037                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
1038
1039         set_freezable();
1040         allow_kernel_signal(SIGKILL);
1041         while (server->tcpStatus != CifsExiting) {
1042                 if (try_to_freeze())
1043                         continue;
1044
1045                 if (!allocate_buffers(server))
1046                         continue;
1047
1048                 server->large_buf = false;
1049                 buf = server->smallbuf;
1050                 pdu_length = 4; /* enough to get RFC1001 header */
1051
1052                 length = cifs_read_from_socket(server, buf, pdu_length);
1053                 if (length < 0)
1054                         continue;
1055
1056                 if (server->vals->header_preamble_size == 0)
1057                         server->total_read = 0;
1058                 else
1059                         server->total_read = length;
1060
1061                 /*
1062                  * The right amount was read from socket - 4 bytes,
1063                  * so we can now interpret the length field.
1064                  */
1065                 pdu_length = get_rfc1002_length(buf);
1066
1067                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
1068                 if (!is_smb_response(server, buf[0]))
1069                         continue;
1070 next_pdu:
1071                 server->pdu_size = pdu_length;
1072
1073                 /* make sure we have enough to get to the MID */
1074                 if (server->pdu_size < HEADER_SIZE(server) - 1 -
1075                     server->vals->header_preamble_size) {
1076                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
1077                                  server->pdu_size);
1078                         cifs_reconnect(server, true);
1079                         continue;
1080                 }
1081
1082                 /* read down to the MID */
1083                 length = cifs_read_from_socket(server,
1084                              buf + server->vals->header_preamble_size,
1085                              HEADER_SIZE(server) - 1
1086                              - server->vals->header_preamble_size);
1087                 if (length < 0)
1088                         continue;
1089                 server->total_read += length;
1090
1091                 if (server->ops->next_header) {
1092                         next_offset = server->ops->next_header(buf);
1093                         if (next_offset)
1094                                 server->pdu_size = next_offset;
1095                 }
1096
1097                 memset(mids, 0, sizeof(mids));
1098                 memset(bufs, 0, sizeof(bufs));
1099                 num_mids = 0;
1100
1101                 if (server->ops->is_transform_hdr &&
1102                     server->ops->receive_transform &&
1103                     server->ops->is_transform_hdr(buf)) {
1104                         length = server->ops->receive_transform(server,
1105                                                                 mids,
1106                                                                 bufs,
1107                                                                 &num_mids);
1108                 } else {
1109                         mids[0] = server->ops->find_mid(server, buf);
1110                         bufs[0] = buf;
1111                         num_mids = 1;
1112
1113                         if (!mids[0] || !mids[0]->receive)
1114                                 length = standard_receive3(server, mids[0]);
1115                         else
1116                                 length = mids[0]->receive(server, mids[0]);
1117                 }
1118
1119                 if (length < 0) {
1120                         for (i = 0; i < num_mids; i++)
1121                                 if (mids[i])
1122                                         cifs_mid_q_entry_release(mids[i]);
1123                         continue;
1124                 }
1125
1126                 if (server->ops->is_status_io_timeout &&
1127                     server->ops->is_status_io_timeout(buf)) {
1128                         num_io_timeout++;
1129                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1130                                 cifs_reconnect(server, false);
1131                                 num_io_timeout = 0;
1132                                 continue;
1133                         }
1134                 }
1135
1136                 server->lstrp = jiffies;
1137
1138                 for (i = 0; i < num_mids; i++) {
1139                         if (mids[i] != NULL) {
1140                                 mids[i]->resp_buf_size = server->pdu_size;
1141
1142                                 if (bufs[i] && server->ops->is_network_name_deleted)
1143                                         server->ops->is_network_name_deleted(bufs[i],
1144                                                                         server);
1145
1146                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1147                                         mids[i]->callback(mids[i]);
1148
1149                                 cifs_mid_q_entry_release(mids[i]);
1150                         } else if (server->ops->is_oplock_break &&
1151                                    server->ops->is_oplock_break(bufs[i],
1152                                                                 server)) {
1153                                 smb2_add_credits_from_hdr(bufs[i], server);
1154                                 cifs_dbg(FYI, "Received oplock break\n");
1155                         } else {
1156                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1157                                                 atomic_read(&midCount));
1158                                 cifs_dump_mem("Received Data is: ", bufs[i],
1159                                               HEADER_SIZE(server));
1160                                 smb2_add_credits_from_hdr(bufs[i], server);
1161 #ifdef CONFIG_CIFS_DEBUG2
1162                                 if (server->ops->dump_detail)
1163                                         server->ops->dump_detail(bufs[i],
1164                                                                  server);
1165                                 cifs_dump_mids(server);
1166 #endif /* CIFS_DEBUG2 */
1167                         }
1168                 }
1169
1170                 if (pdu_length > server->pdu_size) {
1171                         if (!allocate_buffers(server))
1172                                 continue;
1173                         pdu_length -= server->pdu_size;
1174                         server->total_read = 0;
1175                         server->large_buf = false;
1176                         buf = server->smallbuf;
1177                         goto next_pdu;
1178                 }
1179         } /* end while !EXITING */
1180
1181         /* buffer usually freed in free_mid - need to free it here on exit */
1182         cifs_buf_release(server->bigbuf);
1183         if (server->smallbuf) /* no sense logging a debug message if NULL */
1184                 cifs_small_buf_release(server->smallbuf);
1185
1186         task_to_wake = xchg(&server->tsk, NULL);
1187         clean_demultiplex_info(server);
1188
1189         /* if server->tsk was NULL then wait for a signal before exiting */
1190         if (!task_to_wake) {
1191                 set_current_state(TASK_INTERRUPTIBLE);
1192                 while (!signal_pending(current)) {
1193                         schedule();
1194                         set_current_state(TASK_INTERRUPTIBLE);
1195                 }
1196                 set_current_state(TASK_RUNNING);
1197         }
1198
1199         memalloc_noreclaim_restore(noreclaim_flag);
1200         module_put_and_kthread_exit(0);
1201 }
1202
1203 /*
1204  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1205  * if srcaddr is specified and matches the IP address of the rhs argument
1206  */
1207 bool
1208 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1209 {
1210         switch (srcaddr->sa_family) {
1211         case AF_UNSPEC:
1212                 return (rhs->sa_family == AF_UNSPEC);
1213         case AF_INET: {
1214                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1215                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1216                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1217         }
1218         case AF_INET6: {
1219                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1220                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1221                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1222         }
1223         default:
1224                 WARN_ON(1);
1225                 return false; /* don't expect to be here */
1226         }
1227 }
1228
1229 /*
1230  * If no port is specified in addr structure, we try to match with 445 port
1231  * and if it fails - with 139 ports. It should be called only if address
1232  * families of server and addr are equal.
1233  */
1234 static bool
1235 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1236 {
1237         __be16 port, *sport;
1238
1239         /* SMBDirect manages its own ports, don't match it here */
1240         if (server->rdma)
1241                 return true;
1242
1243         switch (addr->sa_family) {
1244         case AF_INET:
1245                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1246                 port = ((struct sockaddr_in *) addr)->sin_port;
1247                 break;
1248         case AF_INET6:
1249                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1250                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1251                 break;
1252         default:
1253                 WARN_ON(1);
1254                 return false;
1255         }
1256
1257         if (!port) {
1258                 port = htons(CIFS_PORT);
1259                 if (port == *sport)
1260                         return true;
1261
1262                 port = htons(RFC1001_PORT);
1263         }
1264
1265         return port == *sport;
1266 }
1267
1268 static bool
1269 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1270               struct sockaddr *srcaddr)
1271 {
1272         switch (addr->sa_family) {
1273         case AF_INET: {
1274                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1275                 struct sockaddr_in *srv_addr4 =
1276                                         (struct sockaddr_in *)&server->dstaddr;
1277
1278                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1279                         return false;
1280                 break;
1281         }
1282         case AF_INET6: {
1283                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1284                 struct sockaddr_in6 *srv_addr6 =
1285                                         (struct sockaddr_in6 *)&server->dstaddr;
1286
1287                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1288                                      &srv_addr6->sin6_addr))
1289                         return false;
1290                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1291                         return false;
1292                 break;
1293         }
1294         default:
1295                 WARN_ON(1);
1296                 return false; /* don't expect to be here */
1297         }
1298
1299         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1300                 return false;
1301
1302         return true;
1303 }
1304
1305 static bool
1306 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1307 {
1308         /*
1309          * The select_sectype function should either return the ctx->sectype
1310          * that was specified, or "Unspecified" if that sectype was not
1311          * compatible with the given NEGOTIATE request.
1312          */
1313         if (server->ops->select_sectype(server, ctx->sectype)
1314              == Unspecified)
1315                 return false;
1316
1317         /*
1318          * Now check if signing mode is acceptable. No need to check
1319          * global_secflags at this point since if MUST_SIGN is set then
1320          * the server->sign had better be too.
1321          */
1322         if (ctx->sign && !server->sign)
1323                 return false;
1324
1325         return true;
1326 }
1327
1328 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1329 {
1330         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1331
1332         if (ctx->nosharesock)
1333                 return 0;
1334
1335         /* this server does not share socket */
1336         if (server->nosharesock)
1337                 return 0;
1338
1339         /* If multidialect negotiation see if existing sessions match one */
1340         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1341                 if (server->vals->protocol_id < SMB30_PROT_ID)
1342                         return 0;
1343         } else if (strcmp(ctx->vals->version_string,
1344                    SMBDEFAULT_VERSION_STRING) == 0) {
1345                 if (server->vals->protocol_id < SMB21_PROT_ID)
1346                         return 0;
1347         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1348                 return 0;
1349
1350         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1351                 return 0;
1352
1353         if (strcasecmp(server->hostname, ctx->server_hostname))
1354                 return 0;
1355
1356         if (!match_address(server, addr,
1357                            (struct sockaddr *)&ctx->srcaddr))
1358                 return 0;
1359
1360         if (!match_port(server, addr))
1361                 return 0;
1362
1363         if (!match_security(server, ctx))
1364                 return 0;
1365
1366         if (server->echo_interval != ctx->echo_interval * HZ)
1367                 return 0;
1368
1369         if (server->rdma != ctx->rdma)
1370                 return 0;
1371
1372         if (server->ignore_signature != ctx->ignore_signature)
1373                 return 0;
1374
1375         if (server->min_offload != ctx->min_offload)
1376                 return 0;
1377
1378         return 1;
1379 }
1380
1381 struct TCP_Server_Info *
1382 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1383 {
1384         struct TCP_Server_Info *server;
1385
1386         spin_lock(&cifs_tcp_ses_lock);
1387         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1388 #ifdef CONFIG_CIFS_DFS_UPCALL
1389                 /*
1390                  * DFS failover implementation in cifs_reconnect() requires unique tcp sessions for
1391                  * DFS connections to do failover properly, so avoid sharing them with regular
1392                  * shares or even links that may connect to same server but having completely
1393                  * different failover targets.
1394                  */
1395                 if (server->is_dfs_conn)
1396                         continue;
1397 #endif
1398                 /*
1399                  * Skip ses channels since they're only handled in lower layers
1400                  * (e.g. cifs_send_recv).
1401                  */
1402                 if (CIFS_SERVER_IS_CHAN(server) || !match_server(server, ctx))
1403                         continue;
1404
1405                 ++server->srv_count;
1406                 spin_unlock(&cifs_tcp_ses_lock);
1407                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1408                 return server;
1409         }
1410         spin_unlock(&cifs_tcp_ses_lock);
1411         return NULL;
1412 }
1413
1414 void
1415 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1416 {
1417         struct task_struct *task;
1418
1419         spin_lock(&cifs_tcp_ses_lock);
1420         if (--server->srv_count > 0) {
1421                 spin_unlock(&cifs_tcp_ses_lock);
1422                 return;
1423         }
1424
1425         /* srv_count can never go negative */
1426         WARN_ON(server->srv_count < 0);
1427
1428         put_net(cifs_net_ns(server));
1429
1430         list_del_init(&server->tcp_ses_list);
1431         spin_unlock(&cifs_tcp_ses_lock);
1432
1433         /* For secondary channels, we pick up ref-count on the primary server */
1434         if (CIFS_SERVER_IS_CHAN(server))
1435                 cifs_put_tcp_session(server->primary_server, from_reconnect);
1436
1437         cancel_delayed_work_sync(&server->echo);
1438         cancel_delayed_work_sync(&server->resolve);
1439
1440         if (from_reconnect)
1441                 /*
1442                  * Avoid deadlock here: reconnect work calls
1443                  * cifs_put_tcp_session() at its end. Need to be sure
1444                  * that reconnect work does nothing with server pointer after
1445                  * that step.
1446                  */
1447                 cancel_delayed_work(&server->reconnect);
1448         else
1449                 cancel_delayed_work_sync(&server->reconnect);
1450
1451         spin_lock(&cifs_tcp_ses_lock);
1452         server->tcpStatus = CifsExiting;
1453         spin_unlock(&cifs_tcp_ses_lock);
1454
1455         cifs_crypto_secmech_release(server);
1456
1457         kfree(server->session_key.response);
1458         server->session_key.response = NULL;
1459         server->session_key.len = 0;
1460         kfree(server->hostname);
1461
1462         task = xchg(&server->tsk, NULL);
1463         if (task)
1464                 send_sig(SIGKILL, task, 1);
1465 }
1466
1467 struct TCP_Server_Info *
1468 cifs_get_tcp_session(struct smb3_fs_context *ctx,
1469                      struct TCP_Server_Info *primary_server)
1470 {
1471         struct TCP_Server_Info *tcp_ses = NULL;
1472         int rc;
1473
1474         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1475
1476         /* see if we already have a matching tcp_ses */
1477         tcp_ses = cifs_find_tcp_session(ctx);
1478         if (tcp_ses)
1479                 return tcp_ses;
1480
1481         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1482         if (!tcp_ses) {
1483                 rc = -ENOMEM;
1484                 goto out_err;
1485         }
1486
1487         tcp_ses->hostname = kstrdup(ctx->server_hostname, GFP_KERNEL);
1488         if (!tcp_ses->hostname) {
1489                 rc = -ENOMEM;
1490                 goto out_err;
1491         }
1492
1493         if (ctx->nosharesock)
1494                 tcp_ses->nosharesock = true;
1495
1496         tcp_ses->ops = ctx->ops;
1497         tcp_ses->vals = ctx->vals;
1498         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1499
1500         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1501         tcp_ses->noblockcnt = ctx->rootfs;
1502         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1503         tcp_ses->noautotune = ctx->noautotune;
1504         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1505         tcp_ses->rdma = ctx->rdma;
1506         tcp_ses->in_flight = 0;
1507         tcp_ses->max_in_flight = 0;
1508         tcp_ses->credits = 1;
1509         if (primary_server) {
1510                 spin_lock(&cifs_tcp_ses_lock);
1511                 ++primary_server->srv_count;
1512                 tcp_ses->primary_server = primary_server;
1513                 spin_unlock(&cifs_tcp_ses_lock);
1514         }
1515         init_waitqueue_head(&tcp_ses->response_q);
1516         init_waitqueue_head(&tcp_ses->request_q);
1517         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1518         mutex_init(&tcp_ses->srv_mutex);
1519         memcpy(tcp_ses->workstation_RFC1001_name,
1520                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1521         memcpy(tcp_ses->server_RFC1001_name,
1522                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1523         tcp_ses->session_estab = false;
1524         tcp_ses->sequence_number = 0;
1525         tcp_ses->reconnect_instance = 1;
1526         tcp_ses->lstrp = jiffies;
1527         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1528         spin_lock_init(&tcp_ses->req_lock);
1529         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1530         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1531         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1532         INIT_DELAYED_WORK(&tcp_ses->resolve, cifs_resolve_server);
1533         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1534         mutex_init(&tcp_ses->reconnect_mutex);
1535 #ifdef CONFIG_CIFS_DFS_UPCALL
1536         mutex_init(&tcp_ses->refpath_lock);
1537 #endif
1538         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1539                sizeof(tcp_ses->srcaddr));
1540         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1541                 sizeof(tcp_ses->dstaddr));
1542         if (ctx->use_client_guid)
1543                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1544                        SMB2_CLIENT_GUID_SIZE);
1545         else
1546                 generate_random_uuid(tcp_ses->client_guid);
1547         /*
1548          * at this point we are the only ones with the pointer
1549          * to the struct since the kernel thread not created yet
1550          * no need to spinlock this init of tcpStatus or srv_count
1551          */
1552         tcp_ses->tcpStatus = CifsNew;
1553         ++tcp_ses->srv_count;
1554
1555         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1556                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1557                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1558         else
1559                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1560         if (tcp_ses->rdma) {
1561 #ifndef CONFIG_CIFS_SMB_DIRECT
1562                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1563                 rc = -ENOENT;
1564                 goto out_err_crypto_release;
1565 #endif
1566                 tcp_ses->smbd_conn = smbd_get_connection(
1567                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1568                 if (tcp_ses->smbd_conn) {
1569                         cifs_dbg(VFS, "RDMA transport established\n");
1570                         rc = 0;
1571                         goto smbd_connected;
1572                 } else {
1573                         rc = -ENOENT;
1574                         goto out_err_crypto_release;
1575                 }
1576         }
1577         rc = ip_connect(tcp_ses);
1578         if (rc < 0) {
1579                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1580                 goto out_err_crypto_release;
1581         }
1582 smbd_connected:
1583         /*
1584          * since we're in a cifs function already, we know that
1585          * this will succeed. No need for try_module_get().
1586          */
1587         __module_get(THIS_MODULE);
1588         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1589                                   tcp_ses, "cifsd");
1590         if (IS_ERR(tcp_ses->tsk)) {
1591                 rc = PTR_ERR(tcp_ses->tsk);
1592                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1593                 module_put(THIS_MODULE);
1594                 goto out_err_crypto_release;
1595         }
1596         tcp_ses->min_offload = ctx->min_offload;
1597         /*
1598          * at this point we are the only ones with the pointer
1599          * to the struct since the kernel thread not created yet
1600          * no need to spinlock this update of tcpStatus
1601          */
1602         spin_lock(&cifs_tcp_ses_lock);
1603         tcp_ses->tcpStatus = CifsNeedNegotiate;
1604         spin_unlock(&cifs_tcp_ses_lock);
1605
1606         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1607                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1608         else
1609                 tcp_ses->max_credits = ctx->max_credits;
1610
1611         tcp_ses->nr_targets = 1;
1612         tcp_ses->ignore_signature = ctx->ignore_signature;
1613         /* thread spawned, put it on the list */
1614         spin_lock(&cifs_tcp_ses_lock);
1615         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1616         spin_unlock(&cifs_tcp_ses_lock);
1617
1618         /* queue echo request delayed work */
1619         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1620
1621         /* queue dns resolution delayed work */
1622         cifs_dbg(FYI, "%s: next dns resolution scheduled for %d seconds in the future\n",
1623                  __func__, SMB_DNS_RESOLVE_INTERVAL_DEFAULT);
1624
1625         queue_delayed_work(cifsiod_wq, &tcp_ses->resolve, (SMB_DNS_RESOLVE_INTERVAL_DEFAULT * HZ));
1626
1627         return tcp_ses;
1628
1629 out_err_crypto_release:
1630         cifs_crypto_secmech_release(tcp_ses);
1631
1632         put_net(cifs_net_ns(tcp_ses));
1633
1634 out_err:
1635         if (tcp_ses) {
1636                 if (CIFS_SERVER_IS_CHAN(tcp_ses))
1637                         cifs_put_tcp_session(tcp_ses->primary_server, false);
1638                 kfree(tcp_ses->hostname);
1639                 if (tcp_ses->ssocket)
1640                         sock_release(tcp_ses->ssocket);
1641                 kfree(tcp_ses);
1642         }
1643         return ERR_PTR(rc);
1644 }
1645
1646 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1647 {
1648         if (ctx->sectype != Unspecified &&
1649             ctx->sectype != ses->sectype)
1650                 return 0;
1651
1652         /*
1653          * If an existing session is limited to less channels than
1654          * requested, it should not be reused
1655          */
1656         spin_lock(&ses->chan_lock);
1657         if (ses->chan_max < ctx->max_channels) {
1658                 spin_unlock(&ses->chan_lock);
1659                 return 0;
1660         }
1661         spin_unlock(&ses->chan_lock);
1662
1663         switch (ses->sectype) {
1664         case Kerberos:
1665                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1666                         return 0;
1667                 break;
1668         default:
1669                 /* NULL username means anonymous session */
1670                 if (ses->user_name == NULL) {
1671                         if (!ctx->nullauth)
1672                                 return 0;
1673                         break;
1674                 }
1675
1676                 /* anything else takes username/password */
1677                 if (strncmp(ses->user_name,
1678                             ctx->username ? ctx->username : "",
1679                             CIFS_MAX_USERNAME_LEN))
1680                         return 0;
1681                 if ((ctx->username && strlen(ctx->username) != 0) &&
1682                     ses->password != NULL &&
1683                     strncmp(ses->password,
1684                             ctx->password ? ctx->password : "",
1685                             CIFS_MAX_PASSWORD_LEN))
1686                         return 0;
1687         }
1688         return 1;
1689 }
1690
1691 /**
1692  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1693  * @ses: smb session to issue the request on
1694  * @ctx: the superblock configuration context to use for building the
1695  *       new tree connection for the IPC (interprocess communication RPC)
1696  *
1697  * A new IPC connection is made and stored in the session
1698  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1699  */
1700 static int
1701 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1702 {
1703         int rc = 0, xid;
1704         struct cifs_tcon *tcon;
1705         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1706         bool seal = false;
1707         struct TCP_Server_Info *server = ses->server;
1708
1709         /*
1710          * If the mount request that resulted in the creation of the
1711          * session requires encryption, force IPC to be encrypted too.
1712          */
1713         if (ctx->seal) {
1714                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1715                         seal = true;
1716                 else {
1717                         cifs_server_dbg(VFS,
1718                                  "IPC: server doesn't support encryption\n");
1719                         return -EOPNOTSUPP;
1720                 }
1721         }
1722
1723         tcon = tconInfoAlloc();
1724         if (tcon == NULL)
1725                 return -ENOMEM;
1726
1727         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1728
1729         xid = get_xid();
1730         tcon->ses = ses;
1731         tcon->ipc = true;
1732         tcon->seal = seal;
1733         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1734         free_xid(xid);
1735
1736         if (rc) {
1737                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1738                 tconInfoFree(tcon);
1739                 goto out;
1740         }
1741
1742         cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid);
1743
1744         ses->tcon_ipc = tcon;
1745 out:
1746         return rc;
1747 }
1748
1749 /**
1750  * cifs_free_ipc - helper to release the session IPC tcon
1751  * @ses: smb session to unmount the IPC from
1752  *
1753  * Needs to be called everytime a session is destroyed.
1754  *
1755  * On session close, the IPC is closed and the server must release all tcons of the session.
1756  * No need to send a tree disconnect here.
1757  *
1758  * Besides, it will make the server to not close durable and resilient files on session close, as
1759  * specified in MS-SMB2 3.3.5.6 Receiving an SMB2 LOGOFF Request.
1760  */
1761 static int
1762 cifs_free_ipc(struct cifs_ses *ses)
1763 {
1764         struct cifs_tcon *tcon = ses->tcon_ipc;
1765
1766         if (tcon == NULL)
1767                 return 0;
1768
1769         tconInfoFree(tcon);
1770         ses->tcon_ipc = NULL;
1771         return 0;
1772 }
1773
1774 static struct cifs_ses *
1775 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1776 {
1777         struct cifs_ses *ses;
1778
1779         spin_lock(&cifs_tcp_ses_lock);
1780         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1781                 if (ses->status == CifsExiting)
1782                         continue;
1783                 if (!match_session(ses, ctx))
1784                         continue;
1785                 ++ses->ses_count;
1786                 spin_unlock(&cifs_tcp_ses_lock);
1787                 return ses;
1788         }
1789         spin_unlock(&cifs_tcp_ses_lock);
1790         return NULL;
1791 }
1792
1793 void cifs_put_smb_ses(struct cifs_ses *ses)
1794 {
1795         unsigned int rc, xid;
1796         unsigned int chan_count;
1797         struct TCP_Server_Info *server = ses->server;
1798         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1799
1800         spin_lock(&cifs_tcp_ses_lock);
1801         if (ses->status == CifsExiting) {
1802                 spin_unlock(&cifs_tcp_ses_lock);
1803                 return;
1804         }
1805
1806         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1807         cifs_dbg(FYI, "%s: ses ipc: %s\n", __func__, ses->tcon_ipc ? ses->tcon_ipc->treeName : "NONE");
1808
1809         if (--ses->ses_count > 0) {
1810                 spin_unlock(&cifs_tcp_ses_lock);
1811                 return;
1812         }
1813
1814         /* ses_count can never go negative */
1815         WARN_ON(ses->ses_count < 0);
1816
1817         if (ses->status == CifsGood)
1818                 ses->status = CifsExiting;
1819         spin_unlock(&cifs_tcp_ses_lock);
1820
1821         cifs_free_ipc(ses);
1822
1823         if (ses->status == CifsExiting && server->ops->logoff) {
1824                 xid = get_xid();
1825                 rc = server->ops->logoff(xid, ses);
1826                 if (rc)
1827                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1828                                 __func__, rc);
1829                 _free_xid(xid);
1830         }
1831
1832         spin_lock(&cifs_tcp_ses_lock);
1833         list_del_init(&ses->smb_ses_list);
1834         spin_unlock(&cifs_tcp_ses_lock);
1835
1836         spin_lock(&ses->chan_lock);
1837         chan_count = ses->chan_count;
1838
1839         /* close any extra channels */
1840         if (chan_count > 1) {
1841                 int i;
1842
1843                 for (i = 1; i < chan_count; i++) {
1844                         spin_unlock(&ses->chan_lock);
1845                         cifs_put_tcp_session(ses->chans[i].server, 0);
1846                         spin_lock(&ses->chan_lock);
1847                         ses->chans[i].server = NULL;
1848                 }
1849         }
1850         spin_unlock(&ses->chan_lock);
1851
1852         sesInfoFree(ses);
1853         cifs_put_tcp_session(server, 0);
1854 }
1855
1856 #ifdef CONFIG_KEYS
1857
1858 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1859 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1860
1861 /* Populate username and pw fields from keyring if possible */
1862 static int
1863 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1864 {
1865         int rc = 0;
1866         int is_domain = 0;
1867         const char *delim, *payload;
1868         char *desc;
1869         ssize_t len;
1870         struct key *key;
1871         struct TCP_Server_Info *server = ses->server;
1872         struct sockaddr_in *sa;
1873         struct sockaddr_in6 *sa6;
1874         const struct user_key_payload *upayload;
1875
1876         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1877         if (!desc)
1878                 return -ENOMEM;
1879
1880         /* try to find an address key first */
1881         switch (server->dstaddr.ss_family) {
1882         case AF_INET:
1883                 sa = (struct sockaddr_in *)&server->dstaddr;
1884                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1885                 break;
1886         case AF_INET6:
1887                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1888                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1889                 break;
1890         default:
1891                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1892                          server->dstaddr.ss_family);
1893                 rc = -EINVAL;
1894                 goto out_err;
1895         }
1896
1897         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1898         key = request_key(&key_type_logon, desc, "");
1899         if (IS_ERR(key)) {
1900                 if (!ses->domainName) {
1901                         cifs_dbg(FYI, "domainName is NULL\n");
1902                         rc = PTR_ERR(key);
1903                         goto out_err;
1904                 }
1905
1906                 /* didn't work, try to find a domain key */
1907                 sprintf(desc, "cifs:d:%s", ses->domainName);
1908                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1909                 key = request_key(&key_type_logon, desc, "");
1910                 if (IS_ERR(key)) {
1911                         rc = PTR_ERR(key);
1912                         goto out_err;
1913                 }
1914                 is_domain = 1;
1915         }
1916
1917         down_read(&key->sem);
1918         upayload = user_key_payload_locked(key);
1919         if (IS_ERR_OR_NULL(upayload)) {
1920                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1921                 goto out_key_put;
1922         }
1923
1924         /* find first : in payload */
1925         payload = upayload->data;
1926         delim = strnchr(payload, upayload->datalen, ':');
1927         cifs_dbg(FYI, "payload=%s\n", payload);
1928         if (!delim) {
1929                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1930                          upayload->datalen);
1931                 rc = -EINVAL;
1932                 goto out_key_put;
1933         }
1934
1935         len = delim - payload;
1936         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1937                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1938                          len);
1939                 rc = -EINVAL;
1940                 goto out_key_put;
1941         }
1942
1943         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1944         if (!ctx->username) {
1945                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1946                          len);
1947                 rc = -ENOMEM;
1948                 goto out_key_put;
1949         }
1950         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
1951
1952         len = key->datalen - (len + 1);
1953         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
1954                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
1955                 rc = -EINVAL;
1956                 kfree(ctx->username);
1957                 ctx->username = NULL;
1958                 goto out_key_put;
1959         }
1960
1961         ++delim;
1962         ctx->password = kstrndup(delim, len, GFP_KERNEL);
1963         if (!ctx->password) {
1964                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
1965                          len);
1966                 rc = -ENOMEM;
1967                 kfree(ctx->username);
1968                 ctx->username = NULL;
1969                 goto out_key_put;
1970         }
1971
1972         /*
1973          * If we have a domain key then we must set the domainName in the
1974          * for the request.
1975          */
1976         if (is_domain && ses->domainName) {
1977                 ctx->domainname = kstrdup(ses->domainName, GFP_KERNEL);
1978                 if (!ctx->domainname) {
1979                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
1980                                  len);
1981                         rc = -ENOMEM;
1982                         kfree(ctx->username);
1983                         ctx->username = NULL;
1984                         kfree_sensitive(ctx->password);
1985                         ctx->password = NULL;
1986                         goto out_key_put;
1987                 }
1988         }
1989
1990         ctx->workstation_name = kstrdup(ses->workstation_name, GFP_KERNEL);
1991         if (!ctx->workstation_name) {
1992                 cifs_dbg(FYI, "Unable to allocate memory for workstation_name\n");
1993                 rc = -ENOMEM;
1994                 kfree(ctx->username);
1995                 ctx->username = NULL;
1996                 kfree_sensitive(ctx->password);
1997                 ctx->password = NULL;
1998                 kfree(ctx->domainname);
1999                 ctx->domainname = NULL;
2000                 goto out_key_put;
2001         }
2002
2003 out_key_put:
2004         up_read(&key->sem);
2005         key_put(key);
2006 out_err:
2007         kfree(desc);
2008         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
2009         return rc;
2010 }
2011 #else /* ! CONFIG_KEYS */
2012 static inline int
2013 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
2014                    struct cifs_ses *ses __attribute__((unused)))
2015 {
2016         return -ENOSYS;
2017 }
2018 #endif /* CONFIG_KEYS */
2019
2020 /**
2021  * cifs_get_smb_ses - get a session matching @ctx data from @server
2022  * @server: server to setup the session to
2023  * @ctx: superblock configuration context to use to setup the session
2024  *
2025  * This function assumes it is being called from cifs_mount() where we
2026  * already got a server reference (server refcount +1). See
2027  * cifs_get_tcon() for refcount explanations.
2028  */
2029 struct cifs_ses *
2030 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
2031 {
2032         int rc = -ENOMEM;
2033         unsigned int xid;
2034         struct cifs_ses *ses;
2035         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2036         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2037
2038         xid = get_xid();
2039
2040         ses = cifs_find_smb_ses(server, ctx);
2041         if (ses) {
2042                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
2043                          ses->status);
2044
2045                 spin_lock(&ses->chan_lock);
2046                 if (cifs_chan_needs_reconnect(ses, server)) {
2047                         spin_unlock(&ses->chan_lock);
2048                         cifs_dbg(FYI, "Session needs reconnect\n");
2049
2050                         mutex_lock(&ses->session_mutex);
2051                         rc = cifs_negotiate_protocol(xid, ses, server);
2052                         if (rc) {
2053                                 mutex_unlock(&ses->session_mutex);
2054                                 /* problem -- put our ses reference */
2055                                 cifs_put_smb_ses(ses);
2056                                 free_xid(xid);
2057                                 return ERR_PTR(rc);
2058                         }
2059
2060                         rc = cifs_setup_session(xid, ses, server,
2061                                                 ctx->local_nls);
2062                         if (rc) {
2063                                 mutex_unlock(&ses->session_mutex);
2064                                 /* problem -- put our reference */
2065                                 cifs_put_smb_ses(ses);
2066                                 free_xid(xid);
2067                                 return ERR_PTR(rc);
2068                         }
2069                         mutex_unlock(&ses->session_mutex);
2070
2071                         spin_lock(&ses->chan_lock);
2072                 }
2073                 spin_unlock(&ses->chan_lock);
2074
2075                 /* existing SMB ses has a server reference already */
2076                 cifs_put_tcp_session(server, 0);
2077                 free_xid(xid);
2078                 return ses;
2079         }
2080
2081         cifs_dbg(FYI, "Existing smb sess not found\n");
2082         ses = sesInfoAlloc();
2083         if (ses == NULL)
2084                 goto get_ses_fail;
2085
2086         /* new SMB session uses our server ref */
2087         ses->server = server;
2088         if (server->dstaddr.ss_family == AF_INET6)
2089                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
2090         else
2091                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
2092
2093         if (ctx->username) {
2094                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
2095                 if (!ses->user_name)
2096                         goto get_ses_fail;
2097         }
2098
2099         /* ctx->password freed at unmount */
2100         if (ctx->password) {
2101                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
2102                 if (!ses->password)
2103                         goto get_ses_fail;
2104         }
2105         if (ctx->domainname) {
2106                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
2107                 if (!ses->domainName)
2108                         goto get_ses_fail;
2109         }
2110         if (ctx->workstation_name) {
2111                 ses->workstation_name = kstrdup(ctx->workstation_name,
2112                                                 GFP_KERNEL);
2113                 if (!ses->workstation_name)
2114                         goto get_ses_fail;
2115         }
2116         if (ctx->domainauto)
2117                 ses->domainAuto = ctx->domainauto;
2118         ses->cred_uid = ctx->cred_uid;
2119         ses->linux_uid = ctx->linux_uid;
2120
2121         ses->sectype = ctx->sectype;
2122         ses->sign = ctx->sign;
2123
2124         /* add server as first channel */
2125         spin_lock(&ses->chan_lock);
2126         ses->chans[0].server = server;
2127         ses->chan_count = 1;
2128         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
2129         ses->chans_need_reconnect = 1;
2130         spin_unlock(&ses->chan_lock);
2131
2132         mutex_lock(&ses->session_mutex);
2133         rc = cifs_negotiate_protocol(xid, ses, server);
2134         if (!rc)
2135                 rc = cifs_setup_session(xid, ses, server, ctx->local_nls);
2136         mutex_unlock(&ses->session_mutex);
2137
2138         /* each channel uses a different signing key */
2139         spin_lock(&ses->chan_lock);
2140         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
2141                sizeof(ses->smb3signingkey));
2142         spin_unlock(&ses->chan_lock);
2143
2144         if (rc)
2145                 goto get_ses_fail;
2146
2147         /*
2148          * success, put it on the list and add it as first channel
2149          * note: the session becomes active soon after this. So you'll
2150          * need to lock before changing something in the session.
2151          */
2152         spin_lock(&cifs_tcp_ses_lock);
2153         list_add(&ses->smb_ses_list, &server->smb_ses_list);
2154         spin_unlock(&cifs_tcp_ses_lock);
2155
2156         free_xid(xid);
2157
2158         cifs_setup_ipc(ses, ctx);
2159
2160         return ses;
2161
2162 get_ses_fail:
2163         sesInfoFree(ses);
2164         free_xid(xid);
2165         return ERR_PTR(rc);
2166 }
2167
2168 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
2169 {
2170         if (tcon->tidStatus == CifsExiting)
2171                 return 0;
2172         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
2173                 return 0;
2174         if (tcon->seal != ctx->seal)
2175                 return 0;
2176         if (tcon->snapshot_time != ctx->snapshot_time)
2177                 return 0;
2178         if (tcon->handle_timeout != ctx->handle_timeout)
2179                 return 0;
2180         if (tcon->no_lease != ctx->no_lease)
2181                 return 0;
2182         if (tcon->nodelete != ctx->nodelete)
2183                 return 0;
2184         return 1;
2185 }
2186
2187 static struct cifs_tcon *
2188 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2189 {
2190         struct list_head *tmp;
2191         struct cifs_tcon *tcon;
2192
2193         spin_lock(&cifs_tcp_ses_lock);
2194         list_for_each(tmp, &ses->tcon_list) {
2195                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
2196
2197                 if (!match_tcon(tcon, ctx))
2198                         continue;
2199                 ++tcon->tc_count;
2200                 spin_unlock(&cifs_tcp_ses_lock);
2201                 return tcon;
2202         }
2203         spin_unlock(&cifs_tcp_ses_lock);
2204         return NULL;
2205 }
2206
2207 void
2208 cifs_put_tcon(struct cifs_tcon *tcon)
2209 {
2210         unsigned int xid;
2211         struct cifs_ses *ses;
2212
2213         /*
2214          * IPC tcon share the lifetime of their session and are
2215          * destroyed in the session put function
2216          */
2217         if (tcon == NULL || tcon->ipc)
2218                 return;
2219
2220         ses = tcon->ses;
2221         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
2222         spin_lock(&cifs_tcp_ses_lock);
2223         if (--tcon->tc_count > 0) {
2224                 spin_unlock(&cifs_tcp_ses_lock);
2225                 return;
2226         }
2227
2228         /* tc_count can never go negative */
2229         WARN_ON(tcon->tc_count < 0);
2230
2231         list_del_init(&tcon->tcon_list);
2232         spin_unlock(&cifs_tcp_ses_lock);
2233
2234         if (tcon->use_witness) {
2235                 int rc;
2236
2237                 rc = cifs_swn_unregister(tcon);
2238                 if (rc < 0) {
2239                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2240                                         __func__, rc);
2241                 }
2242         }
2243
2244         xid = get_xid();
2245         if (ses->server->ops->tree_disconnect)
2246                 ses->server->ops->tree_disconnect(xid, tcon);
2247         _free_xid(xid);
2248
2249         cifs_fscache_release_super_cookie(tcon);
2250         tconInfoFree(tcon);
2251         cifs_put_smb_ses(ses);
2252 }
2253
2254 /**
2255  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2256  * @ses: smb session to issue the request on
2257  * @ctx: the superblock configuration context to use for building the
2258  *
2259  * - tcon refcount is the number of mount points using the tcon.
2260  * - ses refcount is the number of tcon using the session.
2261  *
2262  * 1. This function assumes it is being called from cifs_mount() where
2263  *    we already got a session reference (ses refcount +1).
2264  *
2265  * 2. Since we're in the context of adding a mount point, the end
2266  *    result should be either:
2267  *
2268  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2269  *    its session refcount incremented (1 new tcon). This +1 was
2270  *    already done in (1).
2271  *
2272  * b) an existing tcon with refcount+1 (add a mount point to it) and
2273  *    identical ses refcount (no new tcon). Because of (1) we need to
2274  *    decrement the ses refcount.
2275  */
2276 static struct cifs_tcon *
2277 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2278 {
2279         int rc, xid;
2280         struct cifs_tcon *tcon;
2281
2282         tcon = cifs_find_tcon(ses, ctx);
2283         if (tcon) {
2284                 /*
2285                  * tcon has refcount already incremented but we need to
2286                  * decrement extra ses reference gotten by caller (case b)
2287                  */
2288                 cifs_dbg(FYI, "Found match on UNC path\n");
2289                 cifs_put_smb_ses(ses);
2290                 return tcon;
2291         }
2292
2293         if (!ses->server->ops->tree_connect) {
2294                 rc = -ENOSYS;
2295                 goto out_fail;
2296         }
2297
2298         tcon = tconInfoAlloc();
2299         if (tcon == NULL) {
2300                 rc = -ENOMEM;
2301                 goto out_fail;
2302         }
2303
2304         if (ctx->snapshot_time) {
2305                 if (ses->server->vals->protocol_id == 0) {
2306                         cifs_dbg(VFS,
2307                              "Use SMB2 or later for snapshot mount option\n");
2308                         rc = -EOPNOTSUPP;
2309                         goto out_fail;
2310                 } else
2311                         tcon->snapshot_time = ctx->snapshot_time;
2312         }
2313
2314         if (ctx->handle_timeout) {
2315                 if (ses->server->vals->protocol_id == 0) {
2316                         cifs_dbg(VFS,
2317                              "Use SMB2.1 or later for handle timeout option\n");
2318                         rc = -EOPNOTSUPP;
2319                         goto out_fail;
2320                 } else
2321                         tcon->handle_timeout = ctx->handle_timeout;
2322         }
2323
2324         tcon->ses = ses;
2325         if (ctx->password) {
2326                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2327                 if (!tcon->password) {
2328                         rc = -ENOMEM;
2329                         goto out_fail;
2330                 }
2331         }
2332
2333         if (ctx->seal) {
2334                 if (ses->server->vals->protocol_id == 0) {
2335                         cifs_dbg(VFS,
2336                                  "SMB3 or later required for encryption\n");
2337                         rc = -EOPNOTSUPP;
2338                         goto out_fail;
2339                 } else if (tcon->ses->server->capabilities &
2340                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2341                         tcon->seal = true;
2342                 else {
2343                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2344                         rc = -EOPNOTSUPP;
2345                         goto out_fail;
2346                 }
2347         }
2348
2349         if (ctx->linux_ext) {
2350                 if (ses->server->posix_ext_supported) {
2351                         tcon->posix_extensions = true;
2352                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2353                 } else if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
2354                     (strcmp(ses->server->vals->version_string,
2355                      SMB3ANY_VERSION_STRING) == 0) ||
2356                     (strcmp(ses->server->vals->version_string,
2357                      SMBDEFAULT_VERSION_STRING) == 0)) {
2358                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2359                         rc = -EOPNOTSUPP;
2360                         goto out_fail;
2361                 } else {
2362                         cifs_dbg(VFS, "Check vers= mount option. SMB3.11 "
2363                                 "disabled but required for POSIX extensions\n");
2364                         rc = -EOPNOTSUPP;
2365                         goto out_fail;
2366                 }
2367         }
2368
2369         xid = get_xid();
2370         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2371                                             ctx->local_nls);
2372         free_xid(xid);
2373         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2374         if (rc)
2375                 goto out_fail;
2376
2377         tcon->use_persistent = false;
2378         /* check if SMB2 or later, CIFS does not support persistent handles */
2379         if (ctx->persistent) {
2380                 if (ses->server->vals->protocol_id == 0) {
2381                         cifs_dbg(VFS,
2382                              "SMB3 or later required for persistent handles\n");
2383                         rc = -EOPNOTSUPP;
2384                         goto out_fail;
2385                 } else if (ses->server->capabilities &
2386                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2387                         tcon->use_persistent = true;
2388                 else /* persistent handles requested but not supported */ {
2389                         cifs_dbg(VFS,
2390                                 "Persistent handles not supported on share\n");
2391                         rc = -EOPNOTSUPP;
2392                         goto out_fail;
2393                 }
2394         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2395              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2396              && (ctx->nopersistent == false)) {
2397                 cifs_dbg(FYI, "enabling persistent handles\n");
2398                 tcon->use_persistent = true;
2399         } else if (ctx->resilient) {
2400                 if (ses->server->vals->protocol_id == 0) {
2401                         cifs_dbg(VFS,
2402                              "SMB2.1 or later required for resilient handles\n");
2403                         rc = -EOPNOTSUPP;
2404                         goto out_fail;
2405                 }
2406                 tcon->use_resilient = true;
2407         }
2408
2409         tcon->use_witness = false;
2410         if (IS_ENABLED(CONFIG_CIFS_SWN_UPCALL) && ctx->witness) {
2411                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2412                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2413                                 /*
2414                                  * Set witness in use flag in first place
2415                                  * to retry registration in the echo task
2416                                  */
2417                                 tcon->use_witness = true;
2418                                 /* And try to register immediately */
2419                                 rc = cifs_swn_register(tcon);
2420                                 if (rc < 0) {
2421                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2422                                         goto out_fail;
2423                                 }
2424                         } else {
2425                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2426                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2427                                 rc = -EOPNOTSUPP;
2428                                 goto out_fail;
2429                         }
2430                 } else {
2431                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2432                         rc = -EOPNOTSUPP;
2433                         goto out_fail;
2434                 }
2435         }
2436
2437         /* If the user really knows what they are doing they can override */
2438         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2439                 if (ctx->cache_ro)
2440                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2441                 else if (ctx->cache_rw)
2442                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2443         }
2444
2445         if (ctx->no_lease) {
2446                 if (ses->server->vals->protocol_id == 0) {
2447                         cifs_dbg(VFS,
2448                                 "SMB2 or later required for nolease option\n");
2449                         rc = -EOPNOTSUPP;
2450                         goto out_fail;
2451                 } else
2452                         tcon->no_lease = ctx->no_lease;
2453         }
2454
2455         /*
2456          * We can have only one retry value for a connection to a share so for
2457          * resources mounted more than once to the same server share the last
2458          * value passed in for the retry flag is used.
2459          */
2460         tcon->retry = ctx->retry;
2461         tcon->nocase = ctx->nocase;
2462         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2463                 tcon->nohandlecache = ctx->nohandlecache;
2464         else
2465                 tcon->nohandlecache = true;
2466         tcon->nodelete = ctx->nodelete;
2467         tcon->local_lease = ctx->local_lease;
2468         INIT_LIST_HEAD(&tcon->pending_opens);
2469
2470         spin_lock(&cifs_tcp_ses_lock);
2471         list_add(&tcon->tcon_list, &ses->tcon_list);
2472         spin_unlock(&cifs_tcp_ses_lock);
2473
2474         return tcon;
2475
2476 out_fail:
2477         tconInfoFree(tcon);
2478         return ERR_PTR(rc);
2479 }
2480
2481 void
2482 cifs_put_tlink(struct tcon_link *tlink)
2483 {
2484         if (!tlink || IS_ERR(tlink))
2485                 return;
2486
2487         if (!atomic_dec_and_test(&tlink->tl_count) ||
2488             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2489                 tlink->tl_time = jiffies;
2490                 return;
2491         }
2492
2493         if (!IS_ERR(tlink_tcon(tlink)))
2494                 cifs_put_tcon(tlink_tcon(tlink));
2495         kfree(tlink);
2496         return;
2497 }
2498
2499 static int
2500 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2501 {
2502         struct cifs_sb_info *old = CIFS_SB(sb);
2503         struct cifs_sb_info *new = mnt_data->cifs_sb;
2504         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2505         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2506
2507         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2508                 return 0;
2509
2510         if (old->mnt_cifs_serverino_autodisabled)
2511                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2512
2513         if (oldflags != newflags)
2514                 return 0;
2515
2516         /*
2517          * We want to share sb only if we don't specify an r/wsize or
2518          * specified r/wsize is greater than or equal to existing one.
2519          */
2520         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2521                 return 0;
2522
2523         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2524                 return 0;
2525
2526         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2527             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2528                 return 0;
2529
2530         if (old->ctx->file_mode != new->ctx->file_mode ||
2531             old->ctx->dir_mode != new->ctx->dir_mode)
2532                 return 0;
2533
2534         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2535                 return 0;
2536
2537         if (old->ctx->acregmax != new->ctx->acregmax)
2538                 return 0;
2539         if (old->ctx->acdirmax != new->ctx->acdirmax)
2540                 return 0;
2541
2542         return 1;
2543 }
2544
2545 static int
2546 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2547 {
2548         struct cifs_sb_info *old = CIFS_SB(sb);
2549         struct cifs_sb_info *new = mnt_data->cifs_sb;
2550         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2551                 old->prepath;
2552         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2553                 new->prepath;
2554
2555         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2556                 return 1;
2557         else if (!old_set && !new_set)
2558                 return 1;
2559
2560         return 0;
2561 }
2562
2563 int
2564 cifs_match_super(struct super_block *sb, void *data)
2565 {
2566         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2567         struct smb3_fs_context *ctx;
2568         struct cifs_sb_info *cifs_sb;
2569         struct TCP_Server_Info *tcp_srv;
2570         struct cifs_ses *ses;
2571         struct cifs_tcon *tcon;
2572         struct tcon_link *tlink;
2573         int rc = 0;
2574
2575         spin_lock(&cifs_tcp_ses_lock);
2576         cifs_sb = CIFS_SB(sb);
2577         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2578         if (tlink == NULL) {
2579                 /* can not match superblock if tlink were ever null */
2580                 spin_unlock(&cifs_tcp_ses_lock);
2581                 return 0;
2582         }
2583         tcon = tlink_tcon(tlink);
2584         ses = tcon->ses;
2585         tcp_srv = ses->server;
2586
2587         ctx = mnt_data->ctx;
2588
2589         if (!match_server(tcp_srv, ctx) ||
2590             !match_session(ses, ctx) ||
2591             !match_tcon(tcon, ctx) ||
2592             !match_prepath(sb, mnt_data)) {
2593                 rc = 0;
2594                 goto out;
2595         }
2596
2597         rc = compare_mount_options(sb, mnt_data);
2598 out:
2599         spin_unlock(&cifs_tcp_ses_lock);
2600         cifs_put_tlink(tlink);
2601         return rc;
2602 }
2603
2604 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2605 static struct lock_class_key cifs_key[2];
2606 static struct lock_class_key cifs_slock_key[2];
2607
2608 static inline void
2609 cifs_reclassify_socket4(struct socket *sock)
2610 {
2611         struct sock *sk = sock->sk;
2612         BUG_ON(!sock_allow_reclassification(sk));
2613         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2614                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2615 }
2616
2617 static inline void
2618 cifs_reclassify_socket6(struct socket *sock)
2619 {
2620         struct sock *sk = sock->sk;
2621         BUG_ON(!sock_allow_reclassification(sk));
2622         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2623                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2624 }
2625 #else
2626 static inline void
2627 cifs_reclassify_socket4(struct socket *sock)
2628 {
2629 }
2630
2631 static inline void
2632 cifs_reclassify_socket6(struct socket *sock)
2633 {
2634 }
2635 #endif
2636
2637 /* See RFC1001 section 14 on representation of Netbios names */
2638 static void rfc1002mangle(char *target, char *source, unsigned int length)
2639 {
2640         unsigned int i, j;
2641
2642         for (i = 0, j = 0; i < (length); i++) {
2643                 /* mask a nibble at a time and encode */
2644                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2645                 target[j+1] = 'A' + (0x0F & source[i]);
2646                 j += 2;
2647         }
2648
2649 }
2650
2651 static int
2652 bind_socket(struct TCP_Server_Info *server)
2653 {
2654         int rc = 0;
2655         if (server->srcaddr.ss_family != AF_UNSPEC) {
2656                 /* Bind to the specified local IP address */
2657                 struct socket *socket = server->ssocket;
2658                 rc = socket->ops->bind(socket,
2659                                        (struct sockaddr *) &server->srcaddr,
2660                                        sizeof(server->srcaddr));
2661                 if (rc < 0) {
2662                         struct sockaddr_in *saddr4;
2663                         struct sockaddr_in6 *saddr6;
2664                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2665                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2666                         if (saddr6->sin6_family == AF_INET6)
2667                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2668                                          &saddr6->sin6_addr, rc);
2669                         else
2670                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2671                                          &saddr4->sin_addr.s_addr, rc);
2672                 }
2673         }
2674         return rc;
2675 }
2676
2677 static int
2678 ip_rfc1001_connect(struct TCP_Server_Info *server)
2679 {
2680         int rc = 0;
2681         /*
2682          * some servers require RFC1001 sessinit before sending
2683          * negprot - BB check reconnection in case where second
2684          * sessinit is sent but no second negprot
2685          */
2686         struct rfc1002_session_packet *ses_init_buf;
2687         struct smb_hdr *smb_buf;
2688         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2689                                GFP_KERNEL);
2690         if (ses_init_buf) {
2691                 ses_init_buf->trailer.session_req.called_len = 32;
2692
2693                 if (server->server_RFC1001_name[0] != 0)
2694                         rfc1002mangle(ses_init_buf->trailer.
2695                                       session_req.called_name,
2696                                       server->server_RFC1001_name,
2697                                       RFC1001_NAME_LEN_WITH_NULL);
2698                 else
2699                         rfc1002mangle(ses_init_buf->trailer.
2700                                       session_req.called_name,
2701                                       DEFAULT_CIFS_CALLED_NAME,
2702                                       RFC1001_NAME_LEN_WITH_NULL);
2703
2704                 ses_init_buf->trailer.session_req.calling_len = 32;
2705
2706                 /*
2707                  * calling name ends in null (byte 16) from old smb
2708                  * convention.
2709                  */
2710                 if (server->workstation_RFC1001_name[0] != 0)
2711                         rfc1002mangle(ses_init_buf->trailer.
2712                                       session_req.calling_name,
2713                                       server->workstation_RFC1001_name,
2714                                       RFC1001_NAME_LEN_WITH_NULL);
2715                 else
2716                         rfc1002mangle(ses_init_buf->trailer.
2717                                       session_req.calling_name,
2718                                       "LINUX_CIFS_CLNT",
2719                                       RFC1001_NAME_LEN_WITH_NULL);
2720
2721                 ses_init_buf->trailer.session_req.scope1 = 0;
2722                 ses_init_buf->trailer.session_req.scope2 = 0;
2723                 smb_buf = (struct smb_hdr *)ses_init_buf;
2724
2725                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2726                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2727                 rc = smb_send(server, smb_buf, 0x44);
2728                 kfree(ses_init_buf);
2729                 /*
2730                  * RFC1001 layer in at least one server
2731                  * requires very short break before negprot
2732                  * presumably because not expecting negprot
2733                  * to follow so fast.  This is a simple
2734                  * solution that works without
2735                  * complicating the code and causes no
2736                  * significant slowing down on mount
2737                  * for everyone else
2738                  */
2739                 usleep_range(1000, 2000);
2740         }
2741         /*
2742          * else the negprot may still work without this
2743          * even though malloc failed
2744          */
2745
2746         return rc;
2747 }
2748
2749 static int
2750 generic_ip_connect(struct TCP_Server_Info *server)
2751 {
2752         int rc = 0;
2753         __be16 sport;
2754         int slen, sfamily;
2755         struct socket *socket = server->ssocket;
2756         struct sockaddr *saddr;
2757
2758         saddr = (struct sockaddr *) &server->dstaddr;
2759
2760         if (server->dstaddr.ss_family == AF_INET6) {
2761                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2762
2763                 sport = ipv6->sin6_port;
2764                 slen = sizeof(struct sockaddr_in6);
2765                 sfamily = AF_INET6;
2766                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2767                                 ntohs(sport));
2768         } else {
2769                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2770
2771                 sport = ipv4->sin_port;
2772                 slen = sizeof(struct sockaddr_in);
2773                 sfamily = AF_INET;
2774                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2775                                 ntohs(sport));
2776         }
2777
2778         if (socket == NULL) {
2779                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2780                                    IPPROTO_TCP, &socket, 1);
2781                 if (rc < 0) {
2782                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2783                         server->ssocket = NULL;
2784                         return rc;
2785                 }
2786
2787                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2788                 cifs_dbg(FYI, "Socket created\n");
2789                 server->ssocket = socket;
2790                 socket->sk->sk_allocation = GFP_NOFS;
2791                 if (sfamily == AF_INET6)
2792                         cifs_reclassify_socket6(socket);
2793                 else
2794                         cifs_reclassify_socket4(socket);
2795         }
2796
2797         rc = bind_socket(server);
2798         if (rc < 0)
2799                 return rc;
2800
2801         /*
2802          * Eventually check for other socket options to change from
2803          * the default. sock_setsockopt not used because it expects
2804          * user space buffer
2805          */
2806         socket->sk->sk_rcvtimeo = 7 * HZ;
2807         socket->sk->sk_sndtimeo = 5 * HZ;
2808
2809         /* make the bufsizes depend on wsize/rsize and max requests */
2810         if (server->noautotune) {
2811                 if (socket->sk->sk_sndbuf < (200 * 1024))
2812                         socket->sk->sk_sndbuf = 200 * 1024;
2813                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2814                         socket->sk->sk_rcvbuf = 140 * 1024;
2815         }
2816
2817         if (server->tcp_nodelay)
2818                 tcp_sock_set_nodelay(socket->sk);
2819
2820         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2821                  socket->sk->sk_sndbuf,
2822                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2823
2824         rc = socket->ops->connect(socket, saddr, slen,
2825                                   server->noblockcnt ? O_NONBLOCK : 0);
2826         /*
2827          * When mounting SMB root file systems, we do not want to block in
2828          * connect. Otherwise bail out and then let cifs_reconnect() perform
2829          * reconnect failover - if possible.
2830          */
2831         if (server->noblockcnt && rc == -EINPROGRESS)
2832                 rc = 0;
2833         if (rc < 0) {
2834                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2835                 trace_smb3_connect_err(server->hostname, server->conn_id, &server->dstaddr, rc);
2836                 sock_release(socket);
2837                 server->ssocket = NULL;
2838                 return rc;
2839         }
2840         trace_smb3_connect_done(server->hostname, server->conn_id, &server->dstaddr);
2841         if (sport == htons(RFC1001_PORT))
2842                 rc = ip_rfc1001_connect(server);
2843
2844         return rc;
2845 }
2846
2847 static int
2848 ip_connect(struct TCP_Server_Info *server)
2849 {
2850         __be16 *sport;
2851         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2852         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2853
2854         if (server->dstaddr.ss_family == AF_INET6)
2855                 sport = &addr6->sin6_port;
2856         else
2857                 sport = &addr->sin_port;
2858
2859         if (*sport == 0) {
2860                 int rc;
2861
2862                 /* try with 445 port at first */
2863                 *sport = htons(CIFS_PORT);
2864
2865                 rc = generic_ip_connect(server);
2866                 if (rc >= 0)
2867                         return rc;
2868
2869                 /* if it failed, try with 139 port */
2870                 *sport = htons(RFC1001_PORT);
2871         }
2872
2873         return generic_ip_connect(server);
2874 }
2875
2876 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2877                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2878 {
2879         /*
2880          * If we are reconnecting then should we check to see if
2881          * any requested capabilities changed locally e.g. via
2882          * remount but we can not do much about it here
2883          * if they have (even if we could detect it by the following)
2884          * Perhaps we could add a backpointer to array of sb from tcon
2885          * or if we change to make all sb to same share the same
2886          * sb as NFS - then we only have one backpointer to sb.
2887          * What if we wanted to mount the server share twice once with
2888          * and once without posixacls or posix paths?
2889          */
2890         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2891
2892         if (ctx && ctx->no_linux_ext) {
2893                 tcon->fsUnixInfo.Capability = 0;
2894                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2895                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2896                 return;
2897         } else if (ctx)
2898                 tcon->unix_ext = 1; /* Unix Extensions supported */
2899
2900         if (!tcon->unix_ext) {
2901                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2902                 return;
2903         }
2904
2905         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2906                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2907                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2908                 /*
2909                  * check for reconnect case in which we do not
2910                  * want to change the mount behavior if we can avoid it
2911                  */
2912                 if (ctx == NULL) {
2913                         /*
2914                          * turn off POSIX ACL and PATHNAMES if not set
2915                          * originally at mount time
2916                          */
2917                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2918                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2919                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2920                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2921                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2922                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2923                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2924                                 cifs_dbg(VFS, "possible reconnect error\n");
2925                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2926                         }
2927                 }
2928
2929                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2930                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2931
2932                 cap &= CIFS_UNIX_CAP_MASK;
2933                 if (ctx && ctx->no_psx_acl)
2934                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2935                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2936                         cifs_dbg(FYI, "negotiated posix acl support\n");
2937                         if (cifs_sb)
2938                                 cifs_sb->mnt_cifs_flags |=
2939                                         CIFS_MOUNT_POSIXACL;
2940                 }
2941
2942                 if (ctx && ctx->posix_paths == 0)
2943                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2944                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2945                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2946                         if (cifs_sb)
2947                                 cifs_sb->mnt_cifs_flags |=
2948                                         CIFS_MOUNT_POSIX_PATHS;
2949                 }
2950
2951                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
2952 #ifdef CONFIG_CIFS_DEBUG2
2953                 if (cap & CIFS_UNIX_FCNTL_CAP)
2954                         cifs_dbg(FYI, "FCNTL cap\n");
2955                 if (cap & CIFS_UNIX_EXTATTR_CAP)
2956                         cifs_dbg(FYI, "EXTATTR cap\n");
2957                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2958                         cifs_dbg(FYI, "POSIX path cap\n");
2959                 if (cap & CIFS_UNIX_XATTR_CAP)
2960                         cifs_dbg(FYI, "XATTR cap\n");
2961                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
2962                         cifs_dbg(FYI, "POSIX ACL cap\n");
2963                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
2964                         cifs_dbg(FYI, "very large read cap\n");
2965                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
2966                         cifs_dbg(FYI, "very large write cap\n");
2967                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
2968                         cifs_dbg(FYI, "transport encryption cap\n");
2969                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2970                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
2971 #endif /* CIFS_DEBUG2 */
2972                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
2973                         if (ctx == NULL)
2974                                 cifs_dbg(FYI, "resetting capabilities failed\n");
2975                         else
2976                                 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");
2977
2978                 }
2979         }
2980 }
2981
2982 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
2983 {
2984         struct smb3_fs_context *ctx = cifs_sb->ctx;
2985
2986         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
2987
2988         spin_lock_init(&cifs_sb->tlink_tree_lock);
2989         cifs_sb->tlink_tree = RB_ROOT;
2990
2991         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
2992                  ctx->file_mode, ctx->dir_mode);
2993
2994         /* this is needed for ASCII cp to Unicode converts */
2995         if (ctx->iocharset == NULL) {
2996                 /* load_nls_default cannot return null */
2997                 cifs_sb->local_nls = load_nls_default();
2998         } else {
2999                 cifs_sb->local_nls = load_nls(ctx->iocharset);
3000                 if (cifs_sb->local_nls == NULL) {
3001                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
3002                                  ctx->iocharset);
3003                         return -ELIBACC;
3004                 }
3005         }
3006         ctx->local_nls = cifs_sb->local_nls;
3007
3008         smb3_update_mnt_flags(cifs_sb);
3009
3010         if (ctx->direct_io)
3011                 cifs_dbg(FYI, "mounting share using direct i/o\n");
3012         if (ctx->cache_ro) {
3013                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
3014                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
3015         } else if (ctx->cache_rw) {
3016                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
3017                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
3018                                             CIFS_MOUNT_RW_CACHE);
3019         }
3020
3021         if ((ctx->cifs_acl) && (ctx->dynperm))
3022                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
3023
3024         if (ctx->prepath) {
3025                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
3026                 if (cifs_sb->prepath == NULL)
3027                         return -ENOMEM;
3028                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3029         }
3030
3031         return 0;
3032 }
3033
3034 /* Release all succeed connections */
3035 static inline void mount_put_conns(struct mount_ctx *mnt_ctx)
3036 {
3037         int rc = 0;
3038
3039         if (mnt_ctx->tcon)
3040                 cifs_put_tcon(mnt_ctx->tcon);
3041         else if (mnt_ctx->ses)
3042                 cifs_put_smb_ses(mnt_ctx->ses);
3043         else if (mnt_ctx->server)
3044                 cifs_put_tcp_session(mnt_ctx->server, 0);
3045         mnt_ctx->cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
3046         free_xid(mnt_ctx->xid);
3047 }
3048
3049 /* Get connections for tcp, ses and tcon */
3050 static int mount_get_conns(struct mount_ctx *mnt_ctx)
3051 {
3052         int rc = 0;
3053         struct TCP_Server_Info *server = NULL;
3054         struct cifs_ses *ses = NULL;
3055         struct cifs_tcon *tcon = NULL;
3056         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3057         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3058         unsigned int xid;
3059
3060         xid = get_xid();
3061
3062         /* get a reference to a tcp session */
3063         server = cifs_get_tcp_session(ctx, NULL);
3064         if (IS_ERR(server)) {
3065                 rc = PTR_ERR(server);
3066                 server = NULL;
3067                 goto out;
3068         }
3069
3070         /* get a reference to a SMB session */
3071         ses = cifs_get_smb_ses(server, ctx);
3072         if (IS_ERR(ses)) {
3073                 rc = PTR_ERR(ses);
3074                 ses = NULL;
3075                 goto out;
3076         }
3077
3078         if ((ctx->persistent == true) && (!(ses->server->capabilities &
3079                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
3080                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
3081                 rc = -EOPNOTSUPP;
3082                 goto out;
3083         }
3084
3085         /* search for existing tcon to this server share */
3086         tcon = cifs_get_tcon(ses, ctx);
3087         if (IS_ERR(tcon)) {
3088                 rc = PTR_ERR(tcon);
3089                 tcon = NULL;
3090                 goto out;
3091         }
3092
3093         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
3094         if (tcon->posix_extensions)
3095                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
3096
3097         /* tell server which Unix caps we support */
3098         if (cap_unix(tcon->ses)) {
3099                 /*
3100                  * reset of caps checks mount to see if unix extensions disabled
3101                  * for just this mount.
3102                  */
3103                 reset_cifs_unix_caps(xid, tcon, cifs_sb, ctx);
3104                 spin_lock(&cifs_tcp_ses_lock);
3105                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
3106                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
3107                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)) {
3108                         spin_unlock(&cifs_tcp_ses_lock);
3109                         rc = -EACCES;
3110                         goto out;
3111                 }
3112                 spin_unlock(&cifs_tcp_ses_lock);
3113         } else
3114                 tcon->unix_ext = 0; /* server does not support them */
3115
3116         /* do not care if a following call succeed - informational */
3117         if (!tcon->pipe && server->ops->qfs_tcon) {
3118                 server->ops->qfs_tcon(xid, tcon, cifs_sb);
3119                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
3120                         if (tcon->fsDevInfo.DeviceCharacteristics &
3121                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
3122                                 cifs_dbg(VFS, "mounted to read only share\n");
3123                         else if ((cifs_sb->mnt_cifs_flags &
3124                                   CIFS_MOUNT_RW_CACHE) == 0)
3125                                 cifs_dbg(VFS, "read only mount of RW share\n");
3126                         /* no need to log a RW mount of a typical RW share */
3127                 }
3128         }
3129
3130         /*
3131          * Clamp the rsize/wsize mount arguments if they are too big for the server
3132          * and set the rsize/wsize to the negotiated values if not passed in by
3133          * the user on mount
3134          */
3135         if ((cifs_sb->ctx->wsize == 0) ||
3136             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
3137                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
3138         if ((cifs_sb->ctx->rsize == 0) ||
3139             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
3140                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
3141
3142         /*
3143          * The cookie is initialized from volume info returned above.
3144          * Inside cifs_fscache_get_super_cookie it checks
3145          * that we do not get super cookie twice.
3146          */
3147         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_FSCACHE)
3148                 cifs_fscache_get_super_cookie(tcon);
3149
3150 out:
3151         mnt_ctx->server = server;
3152         mnt_ctx->ses = ses;
3153         mnt_ctx->tcon = tcon;
3154         mnt_ctx->xid = xid;
3155
3156         return rc;
3157 }
3158
3159 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3160                              struct cifs_tcon *tcon)
3161 {
3162         struct tcon_link *tlink;
3163
3164         /* hang the tcon off of the superblock */
3165         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3166         if (tlink == NULL)
3167                 return -ENOMEM;
3168
3169         tlink->tl_uid = ses->linux_uid;
3170         tlink->tl_tcon = tcon;
3171         tlink->tl_time = jiffies;
3172         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
3173         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3174
3175         cifs_sb->master_tlink = tlink;
3176         spin_lock(&cifs_sb->tlink_tree_lock);
3177         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
3178         spin_unlock(&cifs_sb->tlink_tree_lock);
3179
3180         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
3181                                 TLINK_IDLE_EXPIRE);
3182         return 0;
3183 }
3184
3185 #ifdef CONFIG_CIFS_DFS_UPCALL
3186 /* Get unique dfs connections */
3187 static int mount_get_dfs_conns(struct mount_ctx *mnt_ctx)
3188 {
3189         int rc;
3190
3191         mnt_ctx->fs_ctx->nosharesock = true;
3192         rc = mount_get_conns(mnt_ctx);
3193         if (mnt_ctx->server) {
3194                 cifs_dbg(FYI, "%s: marking tcp session as a dfs connection\n", __func__);
3195                 spin_lock(&cifs_tcp_ses_lock);
3196                 mnt_ctx->server->is_dfs_conn = true;
3197                 spin_unlock(&cifs_tcp_ses_lock);
3198         }
3199         return rc;
3200 }
3201
3202 /*
3203  * cifs_build_path_to_root returns full path to root when we do not have an
3204  * existing connection (tcon)
3205  */
3206 static char *
3207 build_unc_path_to_root(const struct smb3_fs_context *ctx,
3208                        const struct cifs_sb_info *cifs_sb, bool useppath)
3209 {
3210         char *full_path, *pos;
3211         unsigned int pplen = useppath && ctx->prepath ?
3212                 strlen(ctx->prepath) + 1 : 0;
3213         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
3214
3215         if (unc_len > MAX_TREE_SIZE)
3216                 return ERR_PTR(-EINVAL);
3217
3218         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
3219         if (full_path == NULL)
3220                 return ERR_PTR(-ENOMEM);
3221
3222         memcpy(full_path, ctx->UNC, unc_len);
3223         pos = full_path + unc_len;
3224
3225         if (pplen) {
3226                 *pos = CIFS_DIR_SEP(cifs_sb);
3227                 memcpy(pos + 1, ctx->prepath, pplen);
3228                 pos += pplen;
3229         }
3230
3231         *pos = '\0'; /* add trailing null */
3232         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
3233         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
3234         return full_path;
3235 }
3236
3237 /*
3238  * expand_dfs_referral - Update cifs_sb from dfs referral path
3239  *
3240  * cifs_sb->ctx->mount_options will be (re-)allocated to a string containing updated options for the
3241  * submount.  Otherwise it will be left untouched.
3242  */
3243 static int expand_dfs_referral(struct mount_ctx *mnt_ctx, const char *full_path,
3244                                struct dfs_info3_param *referral)
3245 {
3246         int rc;
3247         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3248         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3249         char *fake_devname = NULL, *mdata = NULL;
3250
3251         mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, referral,
3252                                            &fake_devname);
3253         if (IS_ERR(mdata)) {
3254                 rc = PTR_ERR(mdata);
3255                 mdata = NULL;
3256         } else {
3257                 /*
3258                  * We can not clear out the whole structure since we no longer have an explicit
3259                  * function to parse a mount-string. Instead we need to clear out the individual
3260                  * fields that are no longer valid.
3261                  */
3262                 kfree(ctx->prepath);
3263                 ctx->prepath = NULL;
3264                 rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3265         }
3266         kfree(fake_devname);
3267         kfree(cifs_sb->ctx->mount_options);
3268         cifs_sb->ctx->mount_options = mdata;
3269
3270         return rc;
3271 }
3272 #endif
3273
3274 /* TODO: all callers to this are broken. We are not parsing mount_options here
3275  * we should pass a clone of the original context?
3276  */
3277 int
3278 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3279 {
3280         int rc;
3281
3282         if (devname) {
3283                 cifs_dbg(FYI, "%s: devname=%s\n", __func__, devname);
3284                 rc = smb3_parse_devname(devname, ctx);
3285                 if (rc) {
3286                         cifs_dbg(VFS, "%s: failed to parse %s: %d\n", __func__, devname, rc);
3287                         return rc;
3288                 }
3289         }
3290
3291         if (mntopts) {
3292                 char *ip;
3293
3294                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3295                 if (rc) {
3296                         cifs_dbg(VFS, "%s: failed to parse ip options: %d\n", __func__, rc);
3297                         return rc;
3298                 }
3299
3300                 rc = cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip, strlen(ip));
3301                 kfree(ip);
3302                 if (!rc) {
3303                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3304                         return -EINVAL;
3305                 }
3306         }
3307
3308         if (ctx->nullauth) {
3309                 cifs_dbg(FYI, "Anonymous login\n");
3310                 kfree(ctx->username);
3311                 ctx->username = NULL;
3312         } else if (ctx->username) {
3313                 /* BB fixme parse for domain name here */
3314                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3315         } else {
3316                 cifs_dbg(VFS, "No username specified\n");
3317         /* In userspace mount helper we can get user name from alternate
3318            locations such as env variables and files on disk */
3319                 return -EINVAL;
3320         }
3321
3322         return 0;
3323 }
3324
3325 static int
3326 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3327                                         unsigned int xid,
3328                                         struct cifs_tcon *tcon,
3329                                         struct cifs_sb_info *cifs_sb,
3330                                         char *full_path,
3331                                         int added_treename)
3332 {
3333         int rc;
3334         char *s;
3335         char sep, tmp;
3336         int skip = added_treename ? 1 : 0;
3337
3338         sep = CIFS_DIR_SEP(cifs_sb);
3339         s = full_path;
3340
3341         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3342         while (rc == 0) {
3343                 /* skip separators */
3344                 while (*s == sep)
3345                         s++;
3346                 if (!*s)
3347                         break;
3348                 /* next separator */
3349                 while (*s && *s != sep)
3350                         s++;
3351                 /*
3352                  * if the treename is added, we then have to skip the first
3353                  * part within the separators
3354                  */
3355                 if (skip) {
3356                         skip = 0;
3357                         continue;
3358                 }
3359                 /*
3360                  * temporarily null-terminate the path at the end of
3361                  * the current component
3362                  */
3363                 tmp = *s;
3364                 *s = 0;
3365                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3366                                                      full_path);
3367                 *s = tmp;
3368         }
3369         return rc;
3370 }
3371
3372 /*
3373  * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
3374  * otherwise 0.
3375  */
3376 static int is_path_remote(struct mount_ctx *mnt_ctx)
3377 {
3378         int rc;
3379         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3380         struct TCP_Server_Info *server = mnt_ctx->server;
3381         unsigned int xid = mnt_ctx->xid;
3382         struct cifs_tcon *tcon = mnt_ctx->tcon;
3383         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3384         char *full_path;
3385
3386         if (!server->ops->is_path_accessible)
3387                 return -EOPNOTSUPP;
3388
3389         /*
3390          * cifs_build_path_to_root works only when we have a valid tcon
3391          */
3392         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3393                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3394         if (full_path == NULL)
3395                 return -ENOMEM;
3396
3397         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3398
3399         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3400                                              full_path);
3401 #ifdef CONFIG_CIFS_DFS_UPCALL
3402         if (rc == -ENOENT && is_tcon_dfs(tcon))
3403                 rc = cifs_dfs_query_info_nonascii_quirk(xid, tcon, cifs_sb,
3404                                                         full_path);
3405 #endif
3406         if (rc != 0 && rc != -EREMOTE) {
3407                 kfree(full_path);
3408                 return rc;
3409         }
3410
3411         if (rc != -EREMOTE) {
3412                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3413                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3414                 if (rc != 0) {
3415                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3416                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3417                         rc = 0;
3418                 }
3419         }
3420
3421         kfree(full_path);
3422         return rc;
3423 }
3424
3425 #ifdef CONFIG_CIFS_DFS_UPCALL
3426 static void set_root_ses(struct mount_ctx *mnt_ctx)
3427 {
3428         if (mnt_ctx->ses) {
3429                 spin_lock(&cifs_tcp_ses_lock);
3430                 mnt_ctx->ses->ses_count++;
3431                 spin_unlock(&cifs_tcp_ses_lock);
3432                 dfs_cache_add_refsrv_session(&mnt_ctx->mount_id, mnt_ctx->ses);
3433         }
3434         mnt_ctx->root_ses = mnt_ctx->ses;
3435 }
3436
3437 static int is_dfs_mount(struct mount_ctx *mnt_ctx, bool *isdfs, struct dfs_cache_tgt_list *root_tl)
3438 {
3439         int rc;
3440         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3441         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3442
3443         *isdfs = true;
3444
3445         rc = mount_get_conns(mnt_ctx);
3446         /*
3447          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3448          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3449          *
3450          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3451          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3452          */
3453         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3454             dfs_cache_find(mnt_ctx->xid, mnt_ctx->ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3455                            ctx->UNC + 1, NULL, root_tl)) {
3456                 if (rc)
3457                         return rc;
3458                 /* Check if it is fully accessible and then mount it */
3459                 rc = is_path_remote(mnt_ctx);
3460                 if (!rc)
3461                         *isdfs = false;
3462                 else if (rc != -EREMOTE)
3463                         return rc;
3464         }
3465         return 0;
3466 }
3467
3468 static int connect_dfs_target(struct mount_ctx *mnt_ctx, const char *full_path,
3469                               const char *ref_path, struct dfs_cache_tgt_iterator *tit)
3470 {
3471         int rc;
3472         struct dfs_info3_param ref = {};
3473         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3474         char *oldmnt = cifs_sb->ctx->mount_options;
3475
3476         rc = dfs_cache_get_tgt_referral(ref_path, tit, &ref);
3477         if (rc)
3478                 goto out;
3479
3480         rc = expand_dfs_referral(mnt_ctx, full_path, &ref);
3481         if (rc)
3482                 goto out;
3483
3484         /* Connect to new target only if we were redirected (e.g. mount options changed) */
3485         if (oldmnt != cifs_sb->ctx->mount_options) {
3486                 mount_put_conns(mnt_ctx);
3487                 rc = mount_get_dfs_conns(mnt_ctx);
3488         }
3489         if (!rc) {
3490                 if (cifs_is_referral_server(mnt_ctx->tcon, &ref))
3491                         set_root_ses(mnt_ctx);
3492                 rc = dfs_cache_update_tgthint(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3493                                               cifs_remap(cifs_sb), ref_path, tit);
3494         }
3495
3496 out:
3497         free_dfs_info_param(&ref);
3498         return rc;
3499 }
3500
3501 static int connect_dfs_root(struct mount_ctx *mnt_ctx, struct dfs_cache_tgt_list *root_tl)
3502 {
3503         int rc;
3504         char *full_path;
3505         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3506         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3507         struct dfs_cache_tgt_iterator *tit;
3508
3509         /* Put initial connections as they might be shared with other mounts.  We need unique dfs
3510          * connections per mount to properly failover, so mount_get_dfs_conns() must be used from
3511          * now on.
3512          */
3513         mount_put_conns(mnt_ctx);
3514         mount_get_dfs_conns(mnt_ctx);
3515         set_root_ses(mnt_ctx);
3516
3517         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3518         if (IS_ERR(full_path))
3519                 return PTR_ERR(full_path);
3520
3521         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(ctx->UNC, cifs_sb->local_nls,
3522                                                             cifs_remap(cifs_sb));
3523         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3524                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3525                 mnt_ctx->origin_fullpath = NULL;
3526                 goto out;
3527         }
3528
3529         /* Try all dfs root targets */
3530         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(root_tl);
3531              tit; tit = dfs_cache_get_next_tgt(root_tl, tit)) {
3532                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->origin_fullpath + 1, tit);
3533                 if (!rc) {
3534                         mnt_ctx->leaf_fullpath = kstrdup(mnt_ctx->origin_fullpath, GFP_KERNEL);
3535                         if (!mnt_ctx->leaf_fullpath)
3536                                 rc = -ENOMEM;
3537                         break;
3538                 }
3539         }
3540
3541 out:
3542         kfree(full_path);
3543         return rc;
3544 }
3545
3546 static int __follow_dfs_link(struct mount_ctx *mnt_ctx)
3547 {
3548         int rc;
3549         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3550         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3551         char *full_path;
3552         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3553         struct dfs_cache_tgt_iterator *tit;
3554
3555         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3556         if (IS_ERR(full_path))
3557                 return PTR_ERR(full_path);
3558
3559         kfree(mnt_ctx->leaf_fullpath);
3560         mnt_ctx->leaf_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3561                                                           cifs_remap(cifs_sb));
3562         if (IS_ERR(mnt_ctx->leaf_fullpath)) {
3563                 rc = PTR_ERR(mnt_ctx->leaf_fullpath);
3564                 mnt_ctx->leaf_fullpath = NULL;
3565                 goto out;
3566         }
3567
3568         /* Get referral from dfs link */
3569         rc = dfs_cache_find(mnt_ctx->xid, mnt_ctx->root_ses, cifs_sb->local_nls,
3570                             cifs_remap(cifs_sb), mnt_ctx->leaf_fullpath + 1, NULL, &tl);
3571         if (rc)
3572                 goto out;
3573
3574         /* Try all dfs link targets */
3575         for (rc = -ENOENT, tit = dfs_cache_get_tgt_iterator(&tl);
3576              tit; tit = dfs_cache_get_next_tgt(&tl, tit)) {
3577                 rc = connect_dfs_target(mnt_ctx, full_path, mnt_ctx->leaf_fullpath + 1, tit);
3578                 if (!rc) {
3579                         rc = is_path_remote(mnt_ctx);
3580                         break;
3581                 }
3582         }
3583
3584 out:
3585         kfree(full_path);
3586         dfs_cache_free_tgts(&tl);
3587         return rc;
3588 }
3589
3590 static int follow_dfs_link(struct mount_ctx *mnt_ctx)
3591 {
3592         int rc;
3593         struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
3594         struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
3595         char *full_path;
3596         int num_links = 0;
3597
3598         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
3599         if (IS_ERR(full_path))
3600                 return PTR_ERR(full_path);
3601
3602         kfree(mnt_ctx->origin_fullpath);
3603         mnt_ctx->origin_fullpath = dfs_cache_canonical_path(full_path, cifs_sb->local_nls,
3604                                                             cifs_remap(cifs_sb));
3605         kfree(full_path);
3606
3607         if (IS_ERR(mnt_ctx->origin_fullpath)) {
3608                 rc = PTR_ERR(mnt_ctx->origin_fullpath);
3609                 mnt_ctx->origin_fullpath = NULL;
3610                 return rc;
3611         }
3612
3613         do {
3614                 rc = __follow_dfs_link(mnt_ctx);
3615                 if (!rc || rc != -EREMOTE)
3616                         break;
3617         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
3618
3619         return rc;
3620 }
3621
3622 /* Set up DFS referral paths for failover */
3623 static void setup_server_referral_paths(struct mount_ctx *mnt_ctx)
3624 {
3625         struct TCP_Server_Info *server = mnt_ctx->server;
3626
3627         server->origin_fullpath = mnt_ctx->origin_fullpath;
3628         server->leaf_fullpath = mnt_ctx->leaf_fullpath;
3629         server->current_fullpath = mnt_ctx->leaf_fullpath;
3630         mnt_ctx->origin_fullpath = mnt_ctx->leaf_fullpath = NULL;
3631 }
3632
3633 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3634 {
3635         int rc;
3636         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3637         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
3638         bool isdfs;
3639
3640         rc = is_dfs_mount(&mnt_ctx, &isdfs, &tl);
3641         if (rc)
3642                 goto error;
3643         if (!isdfs)
3644                 goto out;
3645
3646         uuid_gen(&mnt_ctx.mount_id);
3647         rc = connect_dfs_root(&mnt_ctx, &tl);
3648         dfs_cache_free_tgts(&tl);
3649
3650         if (rc)
3651                 goto error;
3652
3653         rc = is_path_remote(&mnt_ctx);
3654         if (rc == -EREMOTE)
3655                 rc = follow_dfs_link(&mnt_ctx);
3656         if (rc)
3657                 goto error;
3658
3659         setup_server_referral_paths(&mnt_ctx);
3660         /*
3661          * After reconnecting to a different server, unique ids won't match anymore, so we disable
3662          * serverino. This prevents dentry revalidation to think the dentry are stale (ESTALE).
3663          */
3664         cifs_autodisable_serverino(cifs_sb);
3665         /*
3666          * Force the use of prefix path to support failover on DFS paths that resolve to targets
3667          * that have different prefix paths.
3668          */
3669         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3670         kfree(cifs_sb->prepath);
3671         cifs_sb->prepath = ctx->prepath;
3672         ctx->prepath = NULL;
3673         uuid_copy(&cifs_sb->dfs_mount_id, &mnt_ctx.mount_id);
3674
3675 out:
3676         free_xid(mnt_ctx.xid);
3677         cifs_try_adding_channels(cifs_sb, mnt_ctx.ses);
3678         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3679
3680 error:
3681         dfs_cache_put_refsrv_sessions(&mnt_ctx.mount_id);
3682         kfree(mnt_ctx.origin_fullpath);
3683         kfree(mnt_ctx.leaf_fullpath);
3684         mount_put_conns(&mnt_ctx);
3685         return rc;
3686 }
3687 #else
3688 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3689 {
3690         int rc = 0;
3691         struct mount_ctx mnt_ctx = { .cifs_sb = cifs_sb, .fs_ctx = ctx, };
3692
3693         rc = mount_get_conns(&mnt_ctx);
3694         if (rc)
3695                 goto error;
3696
3697         if (mnt_ctx.tcon) {
3698                 rc = is_path_remote(&mnt_ctx);
3699                 if (rc == -EREMOTE)
3700                         rc = -EOPNOTSUPP;
3701                 if (rc)
3702                         goto error;
3703         }
3704
3705         free_xid(mnt_ctx.xid);
3706         return mount_setup_tlink(cifs_sb, mnt_ctx.ses, mnt_ctx.tcon);
3707
3708 error:
3709         mount_put_conns(&mnt_ctx);
3710         return rc;
3711 }
3712 #endif
3713
3714 /*
3715  * Issue a TREE_CONNECT request.
3716  */
3717 int
3718 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3719          const char *tree, struct cifs_tcon *tcon,
3720          const struct nls_table *nls_codepage)
3721 {
3722         struct smb_hdr *smb_buffer;
3723         struct smb_hdr *smb_buffer_response;
3724         TCONX_REQ *pSMB;
3725         TCONX_RSP *pSMBr;
3726         unsigned char *bcc_ptr;
3727         int rc = 0;
3728         int length;
3729         __u16 bytes_left, count;
3730
3731         if (ses == NULL)
3732                 return -EIO;
3733
3734         smb_buffer = cifs_buf_get();
3735         if (smb_buffer == NULL)
3736                 return -ENOMEM;
3737
3738         smb_buffer_response = smb_buffer;
3739
3740         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3741                         NULL /*no tid */ , 4 /*wct */ );
3742
3743         smb_buffer->Mid = get_next_mid(ses->server);
3744         smb_buffer->Uid = ses->Suid;
3745         pSMB = (TCONX_REQ *) smb_buffer;
3746         pSMBr = (TCONX_RSP *) smb_buffer_response;
3747
3748         pSMB->AndXCommand = 0xFF;
3749         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3750         bcc_ptr = &pSMB->Password[0];
3751         if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
3752                 pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3753                 *bcc_ptr = 0; /* password is null byte */
3754                 bcc_ptr++;              /* skip password */
3755                 /* already aligned so no need to do it below */
3756         }
3757
3758         if (ses->server->sign)
3759                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3760
3761         if (ses->capabilities & CAP_STATUS32) {
3762                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3763         }
3764         if (ses->capabilities & CAP_DFS) {
3765                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3766         }
3767         if (ses->capabilities & CAP_UNICODE) {
3768                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3769                 length =
3770                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3771                         6 /* max utf8 char length in bytes */ *
3772                         (/* server len*/ + 256 /* share len */), nls_codepage);
3773                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3774                 bcc_ptr += 2;   /* skip trailing null */
3775         } else {                /* ASCII */
3776                 strcpy(bcc_ptr, tree);
3777                 bcc_ptr += strlen(tree) + 1;
3778         }
3779         strcpy(bcc_ptr, "?????");
3780         bcc_ptr += strlen("?????");
3781         bcc_ptr += 1;
3782         count = bcc_ptr - &pSMB->Password[0];
3783         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3784         pSMB->ByteCount = cpu_to_le16(count);
3785
3786         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3787                          0);
3788
3789         /* above now done in SendReceive */
3790         if (rc == 0) {
3791                 bool is_unicode;
3792
3793                 tcon->tid = smb_buffer_response->Tid;
3794                 bcc_ptr = pByteArea(smb_buffer_response);
3795                 bytes_left = get_bcc(smb_buffer_response);
3796                 length = strnlen(bcc_ptr, bytes_left - 2);
3797                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3798                         is_unicode = true;
3799                 else
3800                         is_unicode = false;
3801
3802
3803                 /* skip service field (NB: this field is always ASCII) */
3804                 if (length == 3) {
3805                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3806                             (bcc_ptr[2] == 'C')) {
3807                                 cifs_dbg(FYI, "IPC connection\n");
3808                                 tcon->ipc = true;
3809                                 tcon->pipe = true;
3810                         }
3811                 } else if (length == 2) {
3812                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3813                                 /* the most common case */
3814                                 cifs_dbg(FYI, "disk share connection\n");
3815                         }
3816                 }
3817                 bcc_ptr += length + 1;
3818                 bytes_left -= (length + 1);
3819                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3820
3821                 /* mostly informational -- no need to fail on error here */
3822                 kfree(tcon->nativeFileSystem);
3823                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3824                                                       bytes_left, is_unicode,
3825                                                       nls_codepage);
3826
3827                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3828
3829                 if ((smb_buffer_response->WordCount == 3) ||
3830                          (smb_buffer_response->WordCount == 7))
3831                         /* field is in same location */
3832                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3833                 else
3834                         tcon->Flags = 0;
3835                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3836         }
3837
3838         cifs_buf_release(smb_buffer);
3839         return rc;
3840 }
3841
3842 static void delayed_free(struct rcu_head *p)
3843 {
3844         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3845
3846         unload_nls(cifs_sb->local_nls);
3847         smb3_cleanup_fs_context(cifs_sb->ctx);
3848         kfree(cifs_sb);
3849 }
3850
3851 void
3852 cifs_umount(struct cifs_sb_info *cifs_sb)
3853 {
3854         struct rb_root *root = &cifs_sb->tlink_tree;
3855         struct rb_node *node;
3856         struct tcon_link *tlink;
3857
3858         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3859
3860         spin_lock(&cifs_sb->tlink_tree_lock);
3861         while ((node = rb_first(root))) {
3862                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3863                 cifs_get_tlink(tlink);
3864                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3865                 rb_erase(node, root);
3866
3867                 spin_unlock(&cifs_sb->tlink_tree_lock);
3868                 cifs_put_tlink(tlink);
3869                 spin_lock(&cifs_sb->tlink_tree_lock);
3870         }
3871         spin_unlock(&cifs_sb->tlink_tree_lock);
3872
3873         kfree(cifs_sb->prepath);
3874 #ifdef CONFIG_CIFS_DFS_UPCALL
3875         dfs_cache_put_refsrv_sessions(&cifs_sb->dfs_mount_id);
3876 #endif
3877         call_rcu(&cifs_sb->rcu, delayed_free);
3878 }
3879
3880 int
3881 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses,
3882                         struct TCP_Server_Info *server)
3883 {
3884         int rc = 0;
3885
3886         if (!server->ops->need_neg || !server->ops->negotiate)
3887                 return -ENOSYS;
3888
3889         /* only send once per connect */
3890         spin_lock(&cifs_tcp_ses_lock);
3891         if (!server->ops->need_neg(server) ||
3892             server->tcpStatus != CifsNeedNegotiate) {
3893                 spin_unlock(&cifs_tcp_ses_lock);
3894                 return 0;
3895         }
3896         server->tcpStatus = CifsInNegotiate;
3897         spin_unlock(&cifs_tcp_ses_lock);
3898
3899         rc = server->ops->negotiate(xid, ses, server);
3900         if (rc == 0) {
3901                 spin_lock(&cifs_tcp_ses_lock);
3902                 if (server->tcpStatus == CifsInNegotiate)
3903                         server->tcpStatus = CifsNeedSessSetup;
3904                 else
3905                         rc = -EHOSTDOWN;
3906                 spin_unlock(&cifs_tcp_ses_lock);
3907         } else {
3908                 spin_lock(&cifs_tcp_ses_lock);
3909                 if (server->tcpStatus == CifsInNegotiate)
3910                         server->tcpStatus = CifsNeedNegotiate;
3911                 spin_unlock(&cifs_tcp_ses_lock);
3912         }
3913
3914         return rc;
3915 }
3916
3917 int
3918 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3919                    struct TCP_Server_Info *server,
3920                    struct nls_table *nls_info)
3921 {
3922         int rc = -ENOSYS;
3923         bool is_binding = false;
3924
3925         /* only send once per connect */
3926         spin_lock(&cifs_tcp_ses_lock);
3927         if ((server->tcpStatus != CifsNeedSessSetup) &&
3928             (ses->status == CifsGood)) {
3929                 spin_unlock(&cifs_tcp_ses_lock);
3930                 return 0;
3931         }
3932         server->tcpStatus = CifsInSessSetup;
3933         spin_unlock(&cifs_tcp_ses_lock);
3934
3935         spin_lock(&ses->chan_lock);
3936         is_binding = !CIFS_ALL_CHANS_NEED_RECONNECT(ses);
3937         spin_unlock(&ses->chan_lock);
3938
3939         if (!is_binding) {
3940                 ses->capabilities = server->capabilities;
3941                 if (!linuxExtEnabled)
3942                         ses->capabilities &= (~server->vals->cap_unix);
3943
3944                 if (ses->auth_key.response) {
3945                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3946                                  ses->auth_key.response);
3947                         kfree(ses->auth_key.response);
3948                         ses->auth_key.response = NULL;
3949                         ses->auth_key.len = 0;
3950                 }
3951         }
3952
3953         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3954                  server->sec_mode, server->capabilities, server->timeAdj);
3955
3956         if (server->ops->sess_setup)
3957                 rc = server->ops->sess_setup(xid, ses, server, nls_info);
3958
3959         if (rc) {
3960                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3961                 spin_lock(&cifs_tcp_ses_lock);
3962                 if (server->tcpStatus == CifsInSessSetup)
3963                         server->tcpStatus = CifsNeedSessSetup;
3964                 spin_unlock(&cifs_tcp_ses_lock);
3965         } else {
3966                 spin_lock(&cifs_tcp_ses_lock);
3967                 if (server->tcpStatus == CifsInSessSetup)
3968                         server->tcpStatus = CifsGood;
3969                 /* Even if one channel is active, session is in good state */
3970                 ses->status = CifsGood;
3971                 spin_unlock(&cifs_tcp_ses_lock);
3972
3973                 spin_lock(&ses->chan_lock);
3974                 cifs_chan_clear_need_reconnect(ses, server);
3975                 spin_unlock(&ses->chan_lock);
3976         }
3977
3978         return rc;
3979 }
3980
3981 static int
3982 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3983 {
3984         ctx->sectype = ses->sectype;
3985
3986         /* krb5 is special, since we don't need username or pw */
3987         if (ctx->sectype == Kerberos)
3988                 return 0;
3989
3990         return cifs_set_cifscreds(ctx, ses);
3991 }
3992
3993 static struct cifs_tcon *
3994 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3995 {
3996         int rc;
3997         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3998         struct cifs_ses *ses;
3999         struct cifs_tcon *tcon = NULL;
4000         struct smb3_fs_context *ctx;
4001
4002         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
4003         if (ctx == NULL)
4004                 return ERR_PTR(-ENOMEM);
4005
4006         ctx->local_nls = cifs_sb->local_nls;
4007         ctx->linux_uid = fsuid;
4008         ctx->cred_uid = fsuid;
4009         ctx->UNC = master_tcon->treeName;
4010         ctx->retry = master_tcon->retry;
4011         ctx->nocase = master_tcon->nocase;
4012         ctx->nohandlecache = master_tcon->nohandlecache;
4013         ctx->local_lease = master_tcon->local_lease;
4014         ctx->no_lease = master_tcon->no_lease;
4015         ctx->resilient = master_tcon->use_resilient;
4016         ctx->persistent = master_tcon->use_persistent;
4017         ctx->handle_timeout = master_tcon->handle_timeout;
4018         ctx->no_linux_ext = !master_tcon->unix_ext;
4019         ctx->linux_ext = master_tcon->posix_extensions;
4020         ctx->sectype = master_tcon->ses->sectype;
4021         ctx->sign = master_tcon->ses->sign;
4022         ctx->seal = master_tcon->seal;
4023         ctx->witness = master_tcon->use_witness;
4024
4025         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
4026         if (rc) {
4027                 tcon = ERR_PTR(rc);
4028                 goto out;
4029         }
4030
4031         /* get a reference for the same TCP session */
4032         spin_lock(&cifs_tcp_ses_lock);
4033         ++master_tcon->ses->server->srv_count;
4034         spin_unlock(&cifs_tcp_ses_lock);
4035
4036         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
4037         if (IS_ERR(ses)) {
4038                 tcon = (struct cifs_tcon *)ses;
4039                 cifs_put_tcp_session(master_tcon->ses->server, 0);
4040                 goto out;
4041         }
4042
4043         tcon = cifs_get_tcon(ses, ctx);
4044         if (IS_ERR(tcon)) {
4045                 cifs_put_smb_ses(ses);
4046                 goto out;
4047         }
4048
4049         if (cap_unix(ses))
4050                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
4051
4052 out:
4053         kfree(ctx->username);
4054         kfree_sensitive(ctx->password);
4055         kfree(ctx);
4056
4057         return tcon;
4058 }
4059
4060 struct cifs_tcon *
4061 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
4062 {
4063         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
4064 }
4065
4066 /* find and return a tlink with given uid */
4067 static struct tcon_link *
4068 tlink_rb_search(struct rb_root *root, kuid_t uid)
4069 {
4070         struct rb_node *node = root->rb_node;
4071         struct tcon_link *tlink;
4072
4073         while (node) {
4074                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
4075
4076                 if (uid_gt(tlink->tl_uid, uid))
4077                         node = node->rb_left;
4078                 else if (uid_lt(tlink->tl_uid, uid))
4079                         node = node->rb_right;
4080                 else
4081                         return tlink;
4082         }
4083         return NULL;
4084 }
4085
4086 /* insert a tcon_link into the tree */
4087 static void
4088 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
4089 {
4090         struct rb_node **new = &(root->rb_node), *parent = NULL;
4091         struct tcon_link *tlink;
4092
4093         while (*new) {
4094                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
4095                 parent = *new;
4096
4097                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
4098                         new = &((*new)->rb_left);
4099                 else
4100                         new = &((*new)->rb_right);
4101         }
4102
4103         rb_link_node(&new_tlink->tl_rbnode, parent, new);
4104         rb_insert_color(&new_tlink->tl_rbnode, root);
4105 }
4106
4107 /*
4108  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
4109  * current task.
4110  *
4111  * If the superblock doesn't refer to a multiuser mount, then just return
4112  * the master tcon for the mount.
4113  *
4114  * First, search the rbtree for an existing tcon for this fsuid. If one
4115  * exists, then check to see if it's pending construction. If it is then wait
4116  * for construction to complete. Once it's no longer pending, check to see if
4117  * it failed and either return an error or retry construction, depending on
4118  * the timeout.
4119  *
4120  * If one doesn't exist then insert a new tcon_link struct into the tree and
4121  * try to construct a new one.
4122  */
4123 struct tcon_link *
4124 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
4125 {
4126         int ret;
4127         kuid_t fsuid = current_fsuid();
4128         struct tcon_link *tlink, *newtlink;
4129
4130         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
4131                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
4132
4133         spin_lock(&cifs_sb->tlink_tree_lock);
4134         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4135         if (tlink)
4136                 cifs_get_tlink(tlink);
4137         spin_unlock(&cifs_sb->tlink_tree_lock);
4138
4139         if (tlink == NULL) {
4140                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
4141                 if (newtlink == NULL)
4142                         return ERR_PTR(-ENOMEM);
4143                 newtlink->tl_uid = fsuid;
4144                 newtlink->tl_tcon = ERR_PTR(-EACCES);
4145                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
4146                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
4147                 cifs_get_tlink(newtlink);
4148
4149                 spin_lock(&cifs_sb->tlink_tree_lock);
4150                 /* was one inserted after previous search? */
4151                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
4152                 if (tlink) {
4153                         cifs_get_tlink(tlink);
4154                         spin_unlock(&cifs_sb->tlink_tree_lock);
4155                         kfree(newtlink);
4156                         goto wait_for_construction;
4157                 }
4158                 tlink = newtlink;
4159                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4160                 spin_unlock(&cifs_sb->tlink_tree_lock);
4161         } else {
4162 wait_for_construction:
4163                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4164                                   TASK_INTERRUPTIBLE);
4165                 if (ret) {
4166                         cifs_put_tlink(tlink);
4167                         return ERR_PTR(-ERESTARTSYS);
4168                 }
4169
4170                 /* if it's good, return it */
4171                 if (!IS_ERR(tlink->tl_tcon))
4172                         return tlink;
4173
4174                 /* return error if we tried this already recently */
4175                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4176                         cifs_put_tlink(tlink);
4177                         return ERR_PTR(-EACCES);
4178                 }
4179
4180                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4181                         goto wait_for_construction;
4182         }
4183
4184         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4185         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4186         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4187
4188         if (IS_ERR(tlink->tl_tcon)) {
4189                 cifs_put_tlink(tlink);
4190                 return ERR_PTR(-EACCES);
4191         }
4192
4193         return tlink;
4194 }
4195
4196 /*
4197  * periodic workqueue job that scans tcon_tree for a superblock and closes
4198  * out tcons.
4199  */
4200 static void
4201 cifs_prune_tlinks(struct work_struct *work)
4202 {
4203         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4204                                                     prune_tlinks.work);
4205         struct rb_root *root = &cifs_sb->tlink_tree;
4206         struct rb_node *node;
4207         struct rb_node *tmp;
4208         struct tcon_link *tlink;
4209
4210         /*
4211          * Because we drop the spinlock in the loop in order to put the tlink
4212          * it's not guarded against removal of links from the tree. The only
4213          * places that remove entries from the tree are this function and
4214          * umounts. Because this function is non-reentrant and is canceled
4215          * before umount can proceed, this is safe.
4216          */
4217         spin_lock(&cifs_sb->tlink_tree_lock);
4218         node = rb_first(root);
4219         while (node != NULL) {
4220                 tmp = node;
4221                 node = rb_next(tmp);
4222                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4223
4224                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4225                     atomic_read(&tlink->tl_count) != 0 ||
4226                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4227                         continue;
4228
4229                 cifs_get_tlink(tlink);
4230                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4231                 rb_erase(tmp, root);
4232
4233                 spin_unlock(&cifs_sb->tlink_tree_lock);
4234                 cifs_put_tlink(tlink);
4235                 spin_lock(&cifs_sb->tlink_tree_lock);
4236         }
4237         spin_unlock(&cifs_sb->tlink_tree_lock);
4238
4239         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4240                                 TLINK_IDLE_EXPIRE);
4241 }
4242
4243 #ifdef CONFIG_CIFS_DFS_UPCALL
4244 /* Update dfs referral path of superblock */
4245 static int update_server_fullpath(struct TCP_Server_Info *server, struct cifs_sb_info *cifs_sb,
4246                                   const char *target)
4247 {
4248         int rc = 0;
4249         size_t len = strlen(target);
4250         char *refpath, *npath;
4251
4252         if (unlikely(len < 2 || *target != '\\'))
4253                 return -EINVAL;
4254
4255         if (target[1] == '\\') {
4256                 len += 1;
4257                 refpath = kmalloc(len, GFP_KERNEL);
4258                 if (!refpath)
4259                         return -ENOMEM;
4260
4261                 scnprintf(refpath, len, "%s", target);
4262         } else {
4263                 len += sizeof("\\");
4264                 refpath = kmalloc(len, GFP_KERNEL);
4265                 if (!refpath)
4266                         return -ENOMEM;
4267
4268                 scnprintf(refpath, len, "\\%s", target);
4269         }
4270
4271         npath = dfs_cache_canonical_path(refpath, cifs_sb->local_nls, cifs_remap(cifs_sb));
4272         kfree(refpath);
4273
4274         if (IS_ERR(npath)) {
4275                 rc = PTR_ERR(npath);
4276         } else {
4277                 mutex_lock(&server->refpath_lock);
4278                 kfree(server->leaf_fullpath);
4279                 server->leaf_fullpath = npath;
4280                 mutex_unlock(&server->refpath_lock);
4281                 server->current_fullpath = server->leaf_fullpath;
4282         }
4283         return rc;
4284 }
4285
4286 static int target_share_matches_server(struct TCP_Server_Info *server, const char *tcp_host,
4287                                        size_t tcp_host_len, char *share, bool *target_match)
4288 {
4289         int rc = 0;
4290         const char *dfs_host;
4291         size_t dfs_host_len;
4292
4293         *target_match = true;
4294         extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4295
4296         /* Check if hostnames or addresses match */
4297         if (dfs_host_len != tcp_host_len || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4298                 cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4299                          dfs_host, (int)tcp_host_len, tcp_host);
4300                 rc = match_target_ip(server, dfs_host, dfs_host_len, target_match);
4301                 if (rc)
4302                         cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4303         }
4304         return rc;
4305 }
4306
4307 static int __tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4308                                      struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4309                                      struct dfs_cache_tgt_list *tl)
4310 {
4311         int rc;
4312         struct TCP_Server_Info *server = tcon->ses->server;
4313         const struct smb_version_operations *ops = server->ops;
4314         struct cifs_tcon *ipc = tcon->ses->tcon_ipc;
4315         char *share = NULL, *prefix = NULL;
4316         const char *tcp_host;
4317         size_t tcp_host_len;
4318         struct dfs_cache_tgt_iterator *tit;
4319         bool target_match;
4320
4321         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4322
4323         tit = dfs_cache_get_tgt_iterator(tl);
4324         if (!tit) {
4325                 rc = -ENOENT;
4326                 goto out;
4327         }
4328
4329         /* Try to tree connect to all dfs targets */
4330         for (; tit; tit = dfs_cache_get_next_tgt(tl, tit)) {
4331                 const char *target = dfs_cache_get_tgt_name(tit);
4332                 struct dfs_cache_tgt_list ntl = DFS_CACHE_TGT_LIST_INIT(ntl);
4333
4334                 kfree(share);
4335                 kfree(prefix);
4336                 share = prefix = NULL;
4337
4338                 /* Check if share matches with tcp ses */
4339                 rc = dfs_cache_get_tgt_share(server->current_fullpath + 1, tit, &share, &prefix);
4340                 if (rc) {
4341                         cifs_dbg(VFS, "%s: failed to parse target share: %d\n", __func__, rc);
4342                         break;
4343                 }
4344
4345                 rc = target_share_matches_server(server, tcp_host, tcp_host_len, share,
4346                                                  &target_match);
4347                 if (rc)
4348                         break;
4349                 if (!target_match) {
4350                         rc = -EHOSTUNREACH;
4351                         continue;
4352                 }
4353
4354                 if (ipc->need_reconnect) {
4355                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4356                         rc = ops->tree_connect(xid, ipc->ses, tree, ipc, cifs_sb->local_nls);
4357                         if (rc)
4358                                 break;
4359                 }
4360
4361                 scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4362                 if (!islink) {
4363                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4364                         break;
4365                 }
4366                 /*
4367                  * If no dfs referrals were returned from link target, then just do a TREE_CONNECT
4368                  * to it.  Otherwise, cache the dfs referral and then mark current tcp ses for
4369                  * reconnect so either the demultiplex thread or the echo worker will reconnect to
4370                  * newly resolved target.
4371                  */
4372                 if (dfs_cache_find(xid, tcon->ses, cifs_sb->local_nls, cifs_remap(cifs_sb), target,
4373                                    NULL, &ntl)) {
4374                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, cifs_sb->local_nls);
4375                         if (rc)
4376                                 continue;
4377                         rc = dfs_cache_noreq_update_tgthint(server->current_fullpath + 1, tit);
4378                         if (!rc)
4379                                 rc = cifs_update_super_prepath(cifs_sb, prefix);
4380                 } else {
4381                         /* Target is another dfs share */
4382                         rc = update_server_fullpath(server, cifs_sb, target);
4383                         dfs_cache_free_tgts(tl);
4384
4385                         if (!rc) {
4386                                 rc = -EREMOTE;
4387                                 list_replace_init(&ntl.tl_list, &tl->tl_list);
4388                         } else
4389                                 dfs_cache_free_tgts(&ntl);
4390                 }
4391                 break;
4392         }
4393
4394 out:
4395         kfree(share);
4396         kfree(prefix);
4397
4398         return rc;
4399 }
4400
4401 static int tree_connect_dfs_target(const unsigned int xid, struct cifs_tcon *tcon,
4402                                    struct cifs_sb_info *cifs_sb, char *tree, bool islink,
4403                                    struct dfs_cache_tgt_list *tl)
4404 {
4405         int rc;
4406         int num_links = 0;
4407         struct TCP_Server_Info *server = tcon->ses->server;
4408
4409         do {
4410                 rc = __tree_connect_dfs_target(xid, tcon, cifs_sb, tree, islink, tl);
4411                 if (!rc || rc != -EREMOTE)
4412                         break;
4413         } while (rc = -ELOOP, ++num_links < MAX_NESTED_LINKS);
4414         /*
4415          * If we couldn't tree connect to any targets from last referral path, then retry from
4416          * original referral path.
4417          */
4418         if (rc && server->current_fullpath != server->origin_fullpath) {
4419                 server->current_fullpath = server->origin_fullpath;
4420                 cifs_reconnect(tcon->ses->server, true);
4421         }
4422
4423         dfs_cache_free_tgts(tl);
4424         return rc;
4425 }
4426
4427 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4428 {
4429         int rc;
4430         struct TCP_Server_Info *server = tcon->ses->server;
4431         const struct smb_version_operations *ops = server->ops;
4432         struct super_block *sb = NULL;
4433         struct cifs_sb_info *cifs_sb;
4434         struct dfs_cache_tgt_list tl = DFS_CACHE_TGT_LIST_INIT(tl);
4435         char *tree;
4436         struct dfs_info3_param ref = {0};
4437
4438         /* only send once per connect */
4439         spin_lock(&cifs_tcp_ses_lock);
4440         if (tcon->ses->status != CifsGood ||
4441             (tcon->tidStatus != CifsNew &&
4442             tcon->tidStatus != CifsNeedTcon)) {
4443                 spin_unlock(&cifs_tcp_ses_lock);
4444                 return 0;
4445         }
4446         tcon->tidStatus = CifsInTcon;
4447         spin_unlock(&cifs_tcp_ses_lock);
4448
4449         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4450         if (!tree) {
4451                 rc = -ENOMEM;
4452                 goto out;
4453         }
4454
4455         if (tcon->ipc) {
4456                 scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4457                 rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4458                 goto out;
4459         }
4460
4461         sb = cifs_get_tcp_super(server);
4462         if (IS_ERR(sb)) {
4463                 rc = PTR_ERR(sb);
4464                 cifs_dbg(VFS, "%s: could not find superblock: %d\n", __func__, rc);
4465                 goto out;
4466         }
4467
4468         cifs_sb = CIFS_SB(sb);
4469
4470         /* If it is not dfs or there was no cached dfs referral, then reconnect to same share */
4471         if (!server->current_fullpath ||
4472             dfs_cache_noreq_find(server->current_fullpath + 1, &ref, &tl)) {
4473                 rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, cifs_sb->local_nls);
4474                 goto out;
4475         }
4476
4477         rc = tree_connect_dfs_target(xid, tcon, cifs_sb, tree, ref.server_type == DFS_TYPE_LINK,
4478                                      &tl);
4479         free_dfs_info_param(&ref);
4480
4481 out:
4482         kfree(tree);
4483         cifs_put_tcp_super(sb);
4484
4485         if (rc) {
4486                 spin_lock(&cifs_tcp_ses_lock);
4487                 if (tcon->tidStatus == CifsInTcon)
4488                         tcon->tidStatus = CifsNeedTcon;
4489                 spin_unlock(&cifs_tcp_ses_lock);
4490         } else {
4491                 spin_lock(&cifs_tcp_ses_lock);
4492                 if (tcon->tidStatus == CifsInTcon)
4493                         tcon->tidStatus = CifsGood;
4494                 spin_unlock(&cifs_tcp_ses_lock);
4495                 tcon->need_reconnect = false;
4496         }
4497
4498         return rc;
4499 }
4500 #else
4501 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4502 {
4503         int rc;
4504         const struct smb_version_operations *ops = tcon->ses->server->ops;
4505
4506         /* only send once per connect */
4507         spin_lock(&cifs_tcp_ses_lock);
4508         if (tcon->ses->status != CifsGood ||
4509             (tcon->tidStatus != CifsNew &&
4510             tcon->tidStatus != CifsNeedTcon)) {
4511                 spin_unlock(&cifs_tcp_ses_lock);
4512                 return 0;
4513         }
4514         tcon->tidStatus = CifsInTcon;
4515         spin_unlock(&cifs_tcp_ses_lock);
4516
4517         rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4518         if (rc) {
4519                 spin_lock(&cifs_tcp_ses_lock);
4520                 if (tcon->tidStatus == CifsInTcon)
4521                         tcon->tidStatus = CifsNeedTcon;
4522                 spin_unlock(&cifs_tcp_ses_lock);
4523         } else {
4524                 spin_lock(&cifs_tcp_ses_lock);
4525                 if (tcon->tidStatus == CifsInTcon)
4526                         tcon->tidStatus = CifsGood;
4527                 spin_unlock(&cifs_tcp_ses_lock);
4528                 tcon->need_reconnect = false;
4529         }
4530
4531         return rc;
4532 }
4533 #endif