fs/cifs/connect.c

   1 /*
   2  *   fs/cifs/connect.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Lesser General Public License as published
   9  *   by the Free Software Foundation; either version 2.1 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This library is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15  *   the GNU Lesser General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Lesser General Public License
  18  *   along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21 #include <linux/fs.h>
  22 #include <linux/net.h>
  23 #include <linux/string.h>
  24 #include <linux/sched/mm.h>
  25 #include <linux/sched/signal.h>
  26 #include <linux/list.h>
  27 #include <linux/wait.h>
  28 #include <linux/slab.h>
  29 #include <linux/pagemap.h>
  30 #include <linux/ctype.h>
  31 #include <linux/utsname.h>
  32 #include <linux/mempool.h>
  33 #include <linux/delay.h>
  34 #include <linux/completion.h>
  35 #include <linux/kthread.h>
  36 #include <linux/pagevec.h>
  37 #include <linux/freezer.h>
  38 #include <linux/namei.h>
  39 #include <linux/uuid.h>
  40 #include <linux/uaccess.h>
  41 #include <asm/processor.h>
  42 #include <linux/inet.h>
  43 #include <linux/module.h>
  44 #include <keys/user-type.h>
  45 #include <net/ipv6.h>
  46 #include <linux/parser.h>
  47 #include <linux/bvec.h>
  48 #include "cifspdu.h"
  49 #include "cifsglob.h"
  50 #include "cifsproto.h"
  51 #include "cifs_unicode.h"
  52 #include "cifs_debug.h"
  53 #include "cifs_fs_sb.h"
  54 #include "ntlmssp.h"
  55 #include "nterr.h"
  56 #include "rfc1002pdu.h"
  57 #include "fscache.h"
  58 #include "smb2proto.h"
  59 #include "smbdirect.h"
  60 #include "dns_resolve.h"
  61 #ifdef CONFIG_CIFS_DFS_UPCALL
  62 #include "dfs_cache.h"
  63 #endif
  64 #include "fs_context.h"
  65 #ifdef CONFIG_CIFS_SWN_UPCALL
  66 #include "cifs_swn.h"
  67 #endif
  68
  69 extern mempool_t *cifs_req_poolp;
  70 extern bool disable_legacy_dialects;
  71
  72 /* FIXME: should these be tunable? */
  73 #define TLINK_ERROR_EXPIRE      (1 * HZ)
  74 #define TLINK_IDLE_EXPIRE       (600 * HZ)
  75
  76 /* Drop the connection to not overload the server */
  77 #define NUM_STATUS_IO_TIMEOUT   5
  78
  79 static int ip_connect(struct TCP_Server_Info *server);
  80 static int generic_ip_connect(struct TCP_Server_Info *server);
  81 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
  82 static void cifs_prune_tlinks(struct work_struct *work);
  83
  84 /*
  85  * Resolve hostname and set ip addr in tcp ses. Useful for hostnames that may
  86  * get their ip addresses changed at some point.
  87  *
  88  * This should be called with server->srv_mutex held.
  89  */
  90 #ifdef CONFIG_CIFS_DFS_UPCALL
  91 static int reconn_set_ipaddr_from_hostname(struct TCP_Server_Info *server)
  92 {
  93         int rc;
  94         int len;
  95         char *unc, *ipaddr = NULL;
  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);
 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                 return rc;
 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         return !rc ? -1 : 0;
 125 }
 126
 127 /* These functions must be called with server->srv_mutex held */
 128 static void reconn_set_next_dfs_target(struct TCP_Server_Info *server,
 129                                        struct cifs_sb_info *cifs_sb,
 130                                        struct dfs_cache_tgt_list *tgt_list,
 131                                        struct dfs_cache_tgt_iterator **tgt_it)
 132 {
 133         const char *name;
 134         int rc;
 135
 136         if (!cifs_sb || !cifs_sb->origin_fullpath)
 137                 return;
 138
 139         if (!*tgt_it) {
 140                 *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
 141         } else {
 142                 *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it);
 143                 if (!*tgt_it)
 144                         *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
 145         }
 146
 147         cifs_dbg(FYI, "%s: UNC: %s\n", __func__, cifs_sb->origin_fullpath);
 148
 149         name = dfs_cache_get_tgt_name(*tgt_it);
 150
 151         kfree(server->hostname);
 152
 153         server->hostname = extract_hostname(name);
 154         if (IS_ERR(server->hostname)) {
 155                 cifs_dbg(FYI,
 156                          "%s: failed to extract hostname from target: %ld\n",
 157                          __func__, PTR_ERR(server->hostname));
 158                 return;
 159         }
 160
 161         rc = reconn_set_ipaddr_from_hostname(server);
 162         if (rc) {
 163                 cifs_dbg(FYI, "%s: failed to resolve hostname: %d\n",
 164                          __func__, rc);
 165         }
 166 }
 167
 168 static inline int reconn_setup_dfs_targets(struct cifs_sb_info *cifs_sb,
 169                                            struct dfs_cache_tgt_list *tl)
 170 {
 171         if (!cifs_sb->origin_fullpath)
 172                 return -EOPNOTSUPP;
 173         return dfs_cache_noreq_find(cifs_sb->origin_fullpath + 1, NULL, tl);
 174 }
 175 #endif
 176
 177 /*
 178  * cifs tcp session reconnection
 179  *
 180  * mark tcp session as reconnecting so temporarily locked
 181  * mark all smb sessions as reconnecting for tcp session
 182  * reconnect tcp session
 183  * wake up waiters on reconnection? - (not needed currently)
 184  */
 185 int
 186 cifs_reconnect(struct TCP_Server_Info *server)
 187 {
 188         int rc = 0;
 189         struct list_head *tmp, *tmp2;
 190         struct cifs_ses *ses;
 191         struct cifs_tcon *tcon;
 192         struct mid_q_entry *mid_entry;
 193         struct list_head retry_list;
 194 #ifdef CONFIG_CIFS_DFS_UPCALL
 195         struct super_block *sb = NULL;
 196         struct cifs_sb_info *cifs_sb = NULL;
 197         struct dfs_cache_tgt_list tgt_list = {0};
 198         struct dfs_cache_tgt_iterator *tgt_it = NULL;
 199 #endif
 200
 201         spin_lock(&GlobalMid_Lock);
 202         server->nr_targets = 1;
 203 #ifdef CONFIG_CIFS_DFS_UPCALL
 204         spin_unlock(&GlobalMid_Lock);
 205         sb = cifs_get_tcp_super(server);
 206         if (IS_ERR(sb)) {
 207                 rc = PTR_ERR(sb);
 208                 cifs_dbg(FYI, "%s: will not do DFS failover: rc = %d\n",
 209                          __func__, rc);
 210                 sb = NULL;
 211         } else {
 212                 cifs_sb = CIFS_SB(sb);
 213                 rc = reconn_setup_dfs_targets(cifs_sb, &tgt_list);
 214                 if (rc) {
 215                         cifs_sb = NULL;
 216                         if (rc != -EOPNOTSUPP) {
 217                                 cifs_server_dbg(VFS, "%s: no target servers for DFS failover\n",
 218                                                 __func__);
 219                         }
 220                 } else {
 221                         server->nr_targets = dfs_cache_get_nr_tgts(&tgt_list);
 222                 }
 223         }
 224         cifs_dbg(FYI, "%s: will retry %d target(s)\n", __func__,
 225                  server->nr_targets);
 226         spin_lock(&GlobalMid_Lock);
 227 #endif
 228         if (server->tcpStatus == CifsExiting) {
 229                 /* the demux thread will exit normally
 230                 next time through the loop */
 231                 spin_unlock(&GlobalMid_Lock);
 232 #ifdef CONFIG_CIFS_DFS_UPCALL
 233                 dfs_cache_free_tgts(&tgt_list);
 234                 cifs_put_tcp_super(sb);
 235 #endif
 236                 wake_up(&server->response_q);
 237                 return rc;
 238         } else
 239                 server->tcpStatus = CifsNeedReconnect;
 240         spin_unlock(&GlobalMid_Lock);
 241         server->maxBuf = 0;
 242         server->max_read = 0;
 243
 244         cifs_dbg(FYI, "Mark tcp session as need reconnect\n");
 245         trace_smb3_reconnect(server->CurrentMid, server->conn_id, server->hostname);
 246
 247         /* before reconnecting the tcp session, mark the smb session (uid)
 248                 and the tid bad so they are not used until reconnected */
 249         cifs_dbg(FYI, "%s: marking sessions and tcons for reconnect\n",
 250                  __func__);
 251         spin_lock(&cifs_tcp_ses_lock);
 252         list_for_each(tmp, &server->smb_ses_list) {
 253                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 254                 ses->need_reconnect = true;
 255                 list_for_each(tmp2, &ses->tcon_list) {
 256                         tcon = list_entry(tmp2, struct cifs_tcon, tcon_list);
 257                         tcon->need_reconnect = true;
 258                 }
 259                 if (ses->tcon_ipc)
 260                         ses->tcon_ipc->need_reconnect = true;
 261         }
 262         spin_unlock(&cifs_tcp_ses_lock);
 263
 264         /* do not want to be sending data on a socket we are freeing */
 265         cifs_dbg(FYI, "%s: tearing down socket\n", __func__);
 266         mutex_lock(&server->srv_mutex);
 267         if (server->ssocket) {
 268                 cifs_dbg(FYI, "State: 0x%x Flags: 0x%lx\n",
 269                          server->ssocket->state, server->ssocket->flags);
 270                 kernel_sock_shutdown(server->ssocket, SHUT_WR);
 271                 cifs_dbg(FYI, "Post shutdown state: 0x%x Flags: 0x%lx\n",
 272                          server->ssocket->state, server->ssocket->flags);
 273                 sock_release(server->ssocket);
 274                 server->ssocket = NULL;
 275         }
 276         server->sequence_number = 0;
 277         server->session_estab = false;
 278         kfree(server->session_key.response);
 279         server->session_key.response = NULL;
 280         server->session_key.len = 0;
 281         server->lstrp = jiffies;
 282
 283         /* mark submitted MIDs for retry and issue callback */
 284         INIT_LIST_HEAD(&retry_list);
 285         cifs_dbg(FYI, "%s: moving mids to private list\n", __func__);
 286         spin_lock(&GlobalMid_Lock);
 287         list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 288                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 289                 kref_get(&mid_entry->refcount);
 290                 if (mid_entry->mid_state == MID_REQUEST_SUBMITTED)
 291                         mid_entry->mid_state = MID_RETRY_NEEDED;
 292                 list_move(&mid_entry->qhead, &retry_list);
 293                 mid_entry->mid_flags |= MID_DELETED;
 294         }
 295         spin_unlock(&GlobalMid_Lock);
 296         mutex_unlock(&server->srv_mutex);
 297
 298         cifs_dbg(FYI, "%s: issuing mid callbacks\n", __func__);
 299         list_for_each_safe(tmp, tmp2, &retry_list) {
 300                 mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 301                 list_del_init(&mid_entry->qhead);
 302                 mid_entry->callback(mid_entry);
 303                 cifs_mid_q_entry_release(mid_entry);
 304         }
 305
 306         if (cifs_rdma_enabled(server)) {
 307                 mutex_lock(&server->srv_mutex);
 308                 smbd_destroy(server);
 309                 mutex_unlock(&server->srv_mutex);
 310         }
 311
 312         do {
 313                 try_to_freeze();
 314
 315                 mutex_lock(&server->srv_mutex);
 316
 317 #ifdef CONFIG_CIFS_SWN_UPCALL
 318                 if (server->use_swn_dstaddr) {
 319                         server->dstaddr = server->swn_dstaddr;
 320                 } else {
 321 #endif
 322
 323 #ifdef CONFIG_CIFS_DFS_UPCALL
 324                         /*
 325                          * Set up next DFS target server (if any) for reconnect. If DFS
 326                          * feature is disabled, then we will retry last server we
 327                          * connected to before.
 328                          */
 329                         reconn_set_next_dfs_target(server, cifs_sb, &tgt_list, &tgt_it);
 330 #endif
 331
 332 #ifdef CONFIG_CIFS_SWN_UPCALL
 333                 }
 334 #endif
 335
 336                 if (cifs_rdma_enabled(server))
 337                         rc = smbd_reconnect(server);
 338                 else
 339                         rc = generic_ip_connect(server);
 340                 if (rc) {
 341                         cifs_dbg(FYI, "reconnect error %d\n", rc);
 342                         mutex_unlock(&server->srv_mutex);
 343                         msleep(3000);
 344                 } else {
 345                         atomic_inc(&tcpSesReconnectCount);
 346                         set_credits(server, 1);
 347                         spin_lock(&GlobalMid_Lock);
 348                         if (server->tcpStatus != CifsExiting)
 349                                 server->tcpStatus = CifsNeedNegotiate;
 350                         spin_unlock(&GlobalMid_Lock);
 351 #ifdef CONFIG_CIFS_SWN_UPCALL
 352                         server->use_swn_dstaddr = false;
 353 #endif
 354                         mutex_unlock(&server->srv_mutex);
 355                 }
 356         } while (server->tcpStatus == CifsNeedReconnect);
 357
 358 #ifdef CONFIG_CIFS_DFS_UPCALL
 359         if (tgt_it) {
 360                 rc = dfs_cache_noreq_update_tgthint(cifs_sb->origin_fullpath + 1,
 361                                                     tgt_it);
 362                 if (rc) {
 363                         cifs_server_dbg(VFS, "%s: failed to update DFS target hint: rc = %d\n",
 364                                  __func__, rc);
 365                 }
 366                 rc = dfs_cache_update_vol(cifs_sb->origin_fullpath, server);
 367                 if (rc) {
 368                         cifs_server_dbg(VFS, "%s: failed to update vol info in DFS cache: rc = %d\n",
 369                                  __func__, rc);
 370                 }
 371                 dfs_cache_free_tgts(&tgt_list);
 372
 373         }
 374
 375         cifs_put_tcp_super(sb);
 376 #endif
 377         if (server->tcpStatus == CifsNeedNegotiate)
 378                 mod_delayed_work(cifsiod_wq, &server->echo, 0);
 379
 380         wake_up(&server->response_q);
 381         return rc;
 382 }
 383
 384 static void
 385 cifs_echo_request(struct work_struct *work)
 386 {
 387         int rc;
 388         struct TCP_Server_Info *server = container_of(work,
 389                                         struct TCP_Server_Info, echo.work);
 390         unsigned long echo_interval;
 391
 392         /*
 393          * If we need to renegotiate, set echo interval to zero to
 394          * immediately call echo service where we can renegotiate.
 395          */
 396         if (server->tcpStatus == CifsNeedNegotiate)
 397                 echo_interval = 0;
 398         else
 399                 echo_interval = server->echo_interval;
 400
 401         /*
 402          * We cannot send an echo if it is disabled.
 403          * Also, no need to ping if we got a response recently.
 404          */
 405
 406         if (server->tcpStatus == CifsNeedReconnect ||
 407             server->tcpStatus == CifsExiting ||
 408             server->tcpStatus == CifsNew ||
 409             (server->ops->can_echo && !server->ops->can_echo(server)) ||
 410             time_before(jiffies, server->lstrp + echo_interval - HZ))
 411                 goto requeue_echo;
 412
 413         rc = server->ops->echo ? server->ops->echo(server) : -ENOSYS;
 414         if (rc)
 415                 cifs_dbg(FYI, "Unable to send echo request to server: %s\n",
 416                          server->hostname);
 417
 418 #ifdef CONFIG_CIFS_SWN_UPCALL
 419         /* Check witness registrations */
 420         cifs_swn_check();
 421 #endif
 422
 423 requeue_echo:
 424         queue_delayed_work(cifsiod_wq, &server->echo, server->echo_interval);
 425 }
 426
 427 static bool
 428 allocate_buffers(struct TCP_Server_Info *server)
 429 {
 430         if (!server->bigbuf) {
 431                 server->bigbuf = (char *)cifs_buf_get();
 432                 if (!server->bigbuf) {
 433                         cifs_server_dbg(VFS, "No memory for large SMB response\n");
 434                         msleep(3000);
 435                         /* retry will check if exiting */
 436                         return false;
 437                 }
 438         } else if (server->large_buf) {
 439                 /* we are reusing a dirty large buf, clear its start */
 440                 memset(server->bigbuf, 0, HEADER_SIZE(server));
 441         }
 442
 443         if (!server->smallbuf) {
 444                 server->smallbuf = (char *)cifs_small_buf_get();
 445                 if (!server->smallbuf) {
 446                         cifs_server_dbg(VFS, "No memory for SMB response\n");
 447                         msleep(1000);
 448                         /* retry will check if exiting */
 449                         return false;
 450                 }
 451                 /* beginning of smb buffer is cleared in our buf_get */
 452         } else {
 453                 /* if existing small buf clear beginning */
 454                 memset(server->smallbuf, 0, HEADER_SIZE(server));
 455         }
 456
 457         return true;
 458 }
 459
 460 static bool
 461 server_unresponsive(struct TCP_Server_Info *server)
 462 {
 463         /*
 464          * We need to wait 3 echo intervals to make sure we handle such
 465          * situations right:
 466          * 1s  client sends a normal SMB request
 467          * 2s  client gets a response
 468          * 30s echo workqueue job pops, and decides we got a response recently
 469          *     and don't need to send another
 470          * ...
 471          * 65s kernel_recvmsg times out, and we see that we haven't gotten
 472          *     a response in >60s.
 473          */
 474         if ((server->tcpStatus == CifsGood ||
 475             server->tcpStatus == CifsNeedNegotiate) &&
 476             time_after(jiffies, server->lstrp + 3 * server->echo_interval)) {
 477                 cifs_server_dbg(VFS, "has not responded in %lu seconds. Reconnecting...\n",
 478                          (3 * server->echo_interval) / HZ);
 479                 cifs_reconnect(server);
 480                 return true;
 481         }
 482
 483         return false;
 484 }
 485
 486 static inline bool
 487 zero_credits(struct TCP_Server_Info *server)
 488 {
 489         int val;
 490
 491         spin_lock(&server->req_lock);
 492         val = server->credits + server->echo_credits + server->oplock_credits;
 493         if (server->in_flight == 0 && val == 0) {
 494                 spin_unlock(&server->req_lock);
 495                 return true;
 496         }
 497         spin_unlock(&server->req_lock);
 498         return false;
 499 }
 500
 501 static int
 502 cifs_readv_from_socket(struct TCP_Server_Info *server, struct msghdr *smb_msg)
 503 {
 504         int length = 0;
 505         int total_read;
 506
 507         smb_msg->msg_control = NULL;
 508         smb_msg->msg_controllen = 0;
 509
 510         for (total_read = 0; msg_data_left(smb_msg); total_read += length) {
 511                 try_to_freeze();
 512
 513                 /* reconnect if no credits and no requests in flight */
 514                 if (zero_credits(server)) {
 515                         cifs_reconnect(server);
 516                         return -ECONNABORTED;
 517                 }
 518
 519                 if (server_unresponsive(server))
 520                         return -ECONNABORTED;
 521                 if (cifs_rdma_enabled(server) && server->smbd_conn)
 522                         length = smbd_recv(server->smbd_conn, smb_msg);
 523                 else
 524                         length = sock_recvmsg(server->ssocket, smb_msg, 0);
 525
 526                 if (server->tcpStatus == CifsExiting)
 527                         return -ESHUTDOWN;
 528
 529                 if (server->tcpStatus == CifsNeedReconnect) {
 530                         cifs_reconnect(server);
 531                         return -ECONNABORTED;
 532                 }
 533
 534                 if (length == -ERESTARTSYS ||
 535                     length == -EAGAIN ||
 536                     length == -EINTR) {
 537                         /*
 538                          * Minimum sleep to prevent looping, allowing socket
 539                          * to clear and app threads to set tcpStatus
 540                          * CifsNeedReconnect if server hung.
 541                          */
 542                         usleep_range(1000, 2000);
 543                         length = 0;
 544                         continue;
 545                 }
 546
 547                 if (length <= 0) {
 548                         cifs_dbg(FYI, "Received no data or error: %d\n", length);
 549                         cifs_reconnect(server);
 550                         return -ECONNABORTED;
 551                 }
 552         }
 553         return total_read;
 554 }
 555
 556 int
 557 cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
 558                       unsigned int to_read)
 559 {
 560         struct msghdr smb_msg;
 561         struct kvec iov = {.iov_base = buf, .iov_len = to_read};
 562         iov_iter_kvec(&smb_msg.msg_iter, READ, &iov, 1, to_read);
 563
 564         return cifs_readv_from_socket(server, &smb_msg);
 565 }
 566
 567 ssize_t
 568 cifs_discard_from_socket(struct TCP_Server_Info *server, size_t to_read)
 569 {
 570         struct msghdr smb_msg;
 571
 572         /*
 573          *  iov_iter_discard already sets smb_msg.type and count and iov_offset
 574          *  and cifs_readv_from_socket sets msg_control and msg_controllen
 575          *  so little to initialize in struct msghdr
 576          */
 577         smb_msg.msg_name = NULL;
 578         smb_msg.msg_namelen = 0;
 579         iov_iter_discard(&smb_msg.msg_iter, READ, to_read);
 580
 581         return cifs_readv_from_socket(server, &smb_msg);
 582 }
 583
 584 int
 585 cifs_read_page_from_socket(struct TCP_Server_Info *server, struct page *page,
 586         unsigned int page_offset, unsigned int to_read)
 587 {
 588         struct msghdr smb_msg;
 589         struct bio_vec bv = {
 590                 .bv_page = page, .bv_len = to_read, .bv_offset = page_offset};
 591         iov_iter_bvec(&smb_msg.msg_iter, READ, &bv, 1, to_read);
 592         return cifs_readv_from_socket(server, &smb_msg);
 593 }
 594
 595 static bool
 596 is_smb_response(struct TCP_Server_Info *server, unsigned char type)
 597 {
 598         /*
 599          * The first byte big endian of the length field,
 600          * is actually not part of the length but the type
 601          * with the most common, zero, as regular data.
 602          */
 603         switch (type) {
 604         case RFC1002_SESSION_MESSAGE:
 605                 /* Regular SMB response */
 606                 return true;
 607         case RFC1002_SESSION_KEEP_ALIVE:
 608                 cifs_dbg(FYI, "RFC 1002 session keep alive\n");
 609                 break;
 610         case RFC1002_POSITIVE_SESSION_RESPONSE:
 611                 cifs_dbg(FYI, "RFC 1002 positive session response\n");
 612                 break;
 613         case RFC1002_NEGATIVE_SESSION_RESPONSE:
 614                 /*
 615                  * We get this from Windows 98 instead of an error on
 616                  * SMB negprot response.
 617                  */
 618                 cifs_dbg(FYI, "RFC 1002 negative session response\n");
 619                 /* give server a second to clean up */
 620                 msleep(1000);
 621                 /*
 622                  * Always try 445 first on reconnect since we get NACK
 623                  * on some if we ever connected to port 139 (the NACK
 624                  * is since we do not begin with RFC1001 session
 625                  * initialize frame).
 626                  */
 627                 cifs_set_port((struct sockaddr *)&server->dstaddr, CIFS_PORT);
 628                 cifs_reconnect(server);
 629                 break;
 630         default:
 631                 cifs_server_dbg(VFS, "RFC 1002 unknown response type 0x%x\n", type);
 632                 cifs_reconnect(server);
 633         }
 634
 635         return false;
 636 }
 637
 638 void
 639 dequeue_mid(struct mid_q_entry *mid, bool malformed)
 640 {
 641 #ifdef CONFIG_CIFS_STATS2
 642         mid->when_received = jiffies;
 643 #endif
 644         spin_lock(&GlobalMid_Lock);
 645         if (!malformed)
 646                 mid->mid_state = MID_RESPONSE_RECEIVED;
 647         else
 648                 mid->mid_state = MID_RESPONSE_MALFORMED;
 649         /*
 650          * Trying to handle/dequeue a mid after the send_recv()
 651          * function has finished processing it is a bug.
 652          */
 653         if (mid->mid_flags & MID_DELETED)
 654                 pr_warn_once("trying to dequeue a deleted mid\n");
 655         else {
 656                 list_del_init(&mid->qhead);
 657                 mid->mid_flags |= MID_DELETED;
 658         }
 659         spin_unlock(&GlobalMid_Lock);
 660 }
 661
 662 static unsigned int
 663 smb2_get_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 664 {
 665         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 666
 667         /*
 668          * SMB1 does not use credits.
 669          */
 670         if (server->vals->header_preamble_size)
 671                 return 0;
 672
 673         return le16_to_cpu(shdr->CreditRequest);
 674 }
 675
 676 static void
 677 handle_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server,
 678            char *buf, int malformed)
 679 {
 680         if (server->ops->check_trans2 &&
 681             server->ops->check_trans2(mid, server, buf, malformed))
 682                 return;
 683         mid->credits_received = smb2_get_credits_from_hdr(buf, server);
 684         mid->resp_buf = buf;
 685         mid->large_buf = server->large_buf;
 686         /* Was previous buf put in mpx struct for multi-rsp? */
 687         if (!mid->multiRsp) {
 688                 /* smb buffer will be freed by user thread */
 689                 if (server->large_buf)
 690                         server->bigbuf = NULL;
 691                 else
 692                         server->smallbuf = NULL;
 693         }
 694         dequeue_mid(mid, malformed);
 695 }
 696
 697 static void clean_demultiplex_info(struct TCP_Server_Info *server)
 698 {
 699         int length;
 700
 701         /* take it off the list, if it's not already */
 702         spin_lock(&cifs_tcp_ses_lock);
 703         list_del_init(&server->tcp_ses_list);
 704         spin_unlock(&cifs_tcp_ses_lock);
 705
 706         cancel_delayed_work_sync(&server->echo);
 707
 708         spin_lock(&GlobalMid_Lock);
 709         server->tcpStatus = CifsExiting;
 710         spin_unlock(&GlobalMid_Lock);
 711         wake_up_all(&server->response_q);
 712
 713         /* check if we have blocked requests that need to free */
 714         spin_lock(&server->req_lock);
 715         if (server->credits <= 0)
 716                 server->credits = 1;
 717         spin_unlock(&server->req_lock);
 718         /*
 719          * Although there should not be any requests blocked on this queue it
 720          * can not hurt to be paranoid and try to wake up requests that may
 721          * haven been blocked when more than 50 at time were on the wire to the
 722          * same server - they now will see the session is in exit state and get
 723          * out of SendReceive.
 724          */
 725         wake_up_all(&server->request_q);
 726         /* give those requests time to exit */
 727         msleep(125);
 728         if (cifs_rdma_enabled(server))
 729                 smbd_destroy(server);
 730         if (server->ssocket) {
 731                 sock_release(server->ssocket);
 732                 server->ssocket = NULL;
 733         }
 734
 735         if (!list_empty(&server->pending_mid_q)) {
 736                 struct list_head dispose_list;
 737                 struct mid_q_entry *mid_entry;
 738                 struct list_head *tmp, *tmp2;
 739
 740                 INIT_LIST_HEAD(&dispose_list);
 741                 spin_lock(&GlobalMid_Lock);
 742                 list_for_each_safe(tmp, tmp2, &server->pending_mid_q) {
 743                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 744                         cifs_dbg(FYI, "Clearing mid %llu\n", mid_entry->mid);
 745                         kref_get(&mid_entry->refcount);
 746                         mid_entry->mid_state = MID_SHUTDOWN;
 747                         list_move(&mid_entry->qhead, &dispose_list);
 748                         mid_entry->mid_flags |= MID_DELETED;
 749                 }
 750                 spin_unlock(&GlobalMid_Lock);
 751
 752                 /* now walk dispose list and issue callbacks */
 753                 list_for_each_safe(tmp, tmp2, &dispose_list) {
 754                         mid_entry = list_entry(tmp, struct mid_q_entry, qhead);
 755                         cifs_dbg(FYI, "Callback mid %llu\n", mid_entry->mid);
 756                         list_del_init(&mid_entry->qhead);
 757                         mid_entry->callback(mid_entry);
 758                         cifs_mid_q_entry_release(mid_entry);
 759                 }
 760                 /* 1/8th of sec is more than enough time for them to exit */
 761                 msleep(125);
 762         }
 763
 764         if (!list_empty(&server->pending_mid_q)) {
 765                 /*
 766                  * mpx threads have not exited yet give them at least the smb
 767                  * send timeout time for long ops.
 768                  *
 769                  * Due to delays on oplock break requests, we need to wait at
 770                  * least 45 seconds before giving up on a request getting a
 771                  * response and going ahead and killing cifsd.
 772                  */
 773                 cifs_dbg(FYI, "Wait for exit from demultiplex thread\n");
 774                 msleep(46000);
 775                 /*
 776                  * If threads still have not exited they are probably never
 777                  * coming home not much else we can do but free the memory.
 778                  */
 779         }
 780
 781         kfree(server->hostname);
 782         kfree(server);
 783
 784         length = atomic_dec_return(&tcpSesAllocCount);
 785         if (length > 0)
 786                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 787 }
 788
 789 static int
 790 standard_receive3(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 791 {
 792         int length;
 793         char *buf = server->smallbuf;
 794         unsigned int pdu_length = server->pdu_size;
 795
 796         /* make sure this will fit in a large buffer */
 797         if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server) -
 798                 server->vals->header_preamble_size) {
 799                 cifs_server_dbg(VFS, "SMB response too long (%u bytes)\n", pdu_length);
 800                 cifs_reconnect(server);
 801                 return -ECONNABORTED;
 802         }
 803
 804         /* switch to large buffer if too big for a small one */
 805         if (pdu_length > MAX_CIFS_SMALL_BUFFER_SIZE - 4) {
 806                 server->large_buf = true;
 807                 memcpy(server->bigbuf, buf, server->total_read);
 808                 buf = server->bigbuf;
 809         }
 810
 811         /* now read the rest */
 812         length = cifs_read_from_socket(server, buf + HEADER_SIZE(server) - 1,
 813                                        pdu_length - HEADER_SIZE(server) + 1
 814                                        + server->vals->header_preamble_size);
 815
 816         if (length < 0)
 817                 return length;
 818         server->total_read += length;
 819
 820         dump_smb(buf, server->total_read);
 821
 822         return cifs_handle_standard(server, mid);
 823 }
 824
 825 int
 826 cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 827 {
 828         char *buf = server->large_buf ? server->bigbuf : server->smallbuf;
 829         int length;
 830
 831         /*
 832          * We know that we received enough to get to the MID as we
 833          * checked the pdu_length earlier. Now check to see
 834          * if the rest of the header is OK. We borrow the length
 835          * var for the rest of the loop to avoid a new stack var.
 836          *
 837          * 48 bytes is enough to display the header and a little bit
 838          * into the payload for debugging purposes.
 839          */
 840         length = server->ops->check_message(buf, server->total_read, server);
 841         if (length != 0)
 842                 cifs_dump_mem("Bad SMB: ", buf,
 843                         min_t(unsigned int, server->total_read, 48));
 844
 845         if (server->ops->is_session_expired &&
 846             server->ops->is_session_expired(buf)) {
 847                 cifs_reconnect(server);
 848                 return -1;
 849         }
 850
 851         if (server->ops->is_status_pending &&
 852             server->ops->is_status_pending(buf, server))
 853                 return -1;
 854
 855         if (!mid)
 856                 return length;
 857
 858         handle_mid(mid, server, buf, length);
 859         return 0;
 860 }
 861
 862 static void
 863 smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
 864 {
 865         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
 866         int scredits, in_flight;
 867
 868         /*
 869          * SMB1 does not use credits.
 870          */
 871         if (server->vals->header_preamble_size)
 872                 return;
 873
 874         if (shdr->CreditRequest) {
 875                 spin_lock(&server->req_lock);
 876                 server->credits += le16_to_cpu(shdr->CreditRequest);
 877                 scredits = server->credits;
 878                 in_flight = server->in_flight;
 879                 spin_unlock(&server->req_lock);
 880                 wake_up(&server->request_q);
 881
 882                 trace_smb3_add_credits(server->CurrentMid,
 883                                 server->conn_id, server->hostname, scredits,
 884                                 le16_to_cpu(shdr->CreditRequest), in_flight);
 885                 cifs_server_dbg(FYI, "%s: added %u credits total=%d\n",
 886                                 __func__, le16_to_cpu(shdr->CreditRequest),
 887                                 scredits);
 888         }
 889 }
 890
 891
 892 static int
 893 cifs_demultiplex_thread(void *p)
 894 {
 895         int i, num_mids, length;
 896         struct TCP_Server_Info *server = p;
 897         unsigned int pdu_length;
 898         unsigned int next_offset;
 899         char *buf = NULL;
 900         struct task_struct *task_to_wake = NULL;
 901         struct mid_q_entry *mids[MAX_COMPOUND];
 902         char *bufs[MAX_COMPOUND];
 903         unsigned int noreclaim_flag, num_io_timeout = 0;
 904
 905         noreclaim_flag = memalloc_noreclaim_save();
 906         cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
 907
 908         length = atomic_inc_return(&tcpSesAllocCount);
 909         if (length > 1)
 910                 mempool_resize(cifs_req_poolp, length + cifs_min_rcv);
 911
 912         set_freezable();
 913         allow_kernel_signal(SIGKILL);
 914         while (server->tcpStatus != CifsExiting) {
 915                 if (try_to_freeze())
 916                         continue;
 917
 918                 if (!allocate_buffers(server))
 919                         continue;
 920
 921                 server->large_buf = false;
 922                 buf = server->smallbuf;
 923                 pdu_length = 4; /* enough to get RFC1001 header */
 924
 925                 length = cifs_read_from_socket(server, buf, pdu_length);
 926                 if (length < 0)
 927                         continue;
 928
 929                 if (server->vals->header_preamble_size == 0)
 930                         server->total_read = 0;
 931                 else
 932                         server->total_read = length;
 933
 934                 /*
 935                  * The right amount was read from socket - 4 bytes,
 936                  * so we can now interpret the length field.
 937                  */
 938                 pdu_length = get_rfc1002_length(buf);
 939
 940                 cifs_dbg(FYI, "RFC1002 header 0x%x\n", pdu_length);
 941                 if (!is_smb_response(server, buf[0]))
 942                         continue;
 943 next_pdu:
 944                 server->pdu_size = pdu_length;
 945
 946                 /* make sure we have enough to get to the MID */
 947                 if (server->pdu_size < HEADER_SIZE(server) - 1 -
 948                     server->vals->header_preamble_size) {
 949                         cifs_server_dbg(VFS, "SMB response too short (%u bytes)\n",
 950                                  server->pdu_size);
 951                         cifs_reconnect(server);
 952                         continue;
 953                 }
 954
 955                 /* read down to the MID */
 956                 length = cifs_read_from_socket(server,
 957                              buf + server->vals->header_preamble_size,
 958                              HEADER_SIZE(server) - 1
 959                              - server->vals->header_preamble_size);
 960                 if (length < 0)
 961                         continue;
 962                 server->total_read += length;
 963
 964                 if (server->ops->next_header) {
 965                         next_offset = server->ops->next_header(buf);
 966                         if (next_offset)
 967                                 server->pdu_size = next_offset;
 968                 }
 969
 970                 memset(mids, 0, sizeof(mids));
 971                 memset(bufs, 0, sizeof(bufs));
 972                 num_mids = 0;
 973
 974                 if (server->ops->is_transform_hdr &&
 975                     server->ops->receive_transform &&
 976                     server->ops->is_transform_hdr(buf)) {
 977                         length = server->ops->receive_transform(server,
 978                                                                 mids,
 979                                                                 bufs,
 980                                                                 &num_mids);
 981                 } else {
 982                         mids[0] = server->ops->find_mid(server, buf);
 983                         bufs[0] = buf;
 984                         num_mids = 1;
 985
 986                         if (!mids[0] || !mids[0]->receive)
 987                                 length = standard_receive3(server, mids[0]);
 988                         else
 989                                 length = mids[0]->receive(server, mids[0]);
 990                 }
 991
 992                 if (length < 0) {
 993                         for (i = 0; i < num_mids; i++)
 994                                 if (mids[i])
 995                                         cifs_mid_q_entry_release(mids[i]);
 996                         continue;
 997                 }
 998
 999                 if (server->ops->is_status_io_timeout &&
1000                     server->ops->is_status_io_timeout(buf)) {
1001                         num_io_timeout++;
1002                         if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
1003                                 cifs_reconnect(server);
1004                                 num_io_timeout = 0;
1005                                 continue;
1006                         }
1007                 }
1008
1009                 server->lstrp = jiffies;
1010
1011                 for (i = 0; i < num_mids; i++) {
1012                         if (mids[i] != NULL) {
1013                                 mids[i]->resp_buf_size = server->pdu_size;
1014
1015                                 if (bufs[i] && server->ops->is_network_name_deleted)
1016                                         server->ops->is_network_name_deleted(bufs[i],
1017                                                                         server);
1018
1019                                 if (!mids[i]->multiRsp || mids[i]->multiEnd)
1020                                         mids[i]->callback(mids[i]);
1021
1022                                 cifs_mid_q_entry_release(mids[i]);
1023                         } else if (server->ops->is_oplock_break &&
1024                                    server->ops->is_oplock_break(bufs[i],
1025                                                                 server)) {
1026                                 smb2_add_credits_from_hdr(bufs[i], server);
1027                                 cifs_dbg(FYI, "Received oplock break\n");
1028                         } else {
1029                                 cifs_server_dbg(VFS, "No task to wake, unknown frame received! NumMids %d\n",
1030                                                 atomic_read(&midCount));
1031                                 cifs_dump_mem("Received Data is: ", bufs[i],
1032                                               HEADER_SIZE(server));
1033                                 smb2_add_credits_from_hdr(bufs[i], server);
1034 #ifdef CONFIG_CIFS_DEBUG2
1035                                 if (server->ops->dump_detail)
1036                                         server->ops->dump_detail(bufs[i],
1037                                                                  server);
1038                                 cifs_dump_mids(server);
1039 #endif /* CIFS_DEBUG2 */
1040                         }
1041                 }
1042
1043                 if (pdu_length > server->pdu_size) {
1044                         if (!allocate_buffers(server))
1045                                 continue;
1046                         pdu_length -= server->pdu_size;
1047                         server->total_read = 0;
1048                         server->large_buf = false;
1049                         buf = server->smallbuf;
1050                         goto next_pdu;
1051                 }
1052         } /* end while !EXITING */
1053
1054         /* buffer usually freed in free_mid - need to free it here on exit */
1055         cifs_buf_release(server->bigbuf);
1056         if (server->smallbuf) /* no sense logging a debug message if NULL */
1057                 cifs_small_buf_release(server->smallbuf);
1058
1059         task_to_wake = xchg(&server->tsk, NULL);
1060         clean_demultiplex_info(server);
1061
1062         /* if server->tsk was NULL then wait for a signal before exiting */
1063         if (!task_to_wake) {
1064                 set_current_state(TASK_INTERRUPTIBLE);
1065                 while (!signal_pending(current)) {
1066                         schedule();
1067                         set_current_state(TASK_INTERRUPTIBLE);
1068                 }
1069                 set_current_state(TASK_RUNNING);
1070         }
1071
1072         memalloc_noreclaim_restore(noreclaim_flag);
1073         module_put_and_exit(0);
1074 }
1075
1076 /**
1077  * Returns true if srcaddr isn't specified and rhs isn't specified, or
1078  * if srcaddr is specified and matches the IP address of the rhs argument
1079  */
1080 bool
1081 cifs_match_ipaddr(struct sockaddr *srcaddr, struct sockaddr *rhs)
1082 {
1083         switch (srcaddr->sa_family) {
1084         case AF_UNSPEC:
1085                 return (rhs->sa_family == AF_UNSPEC);
1086         case AF_INET: {
1087                 struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
1088                 struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
1089                 return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
1090         }
1091         case AF_INET6: {
1092                 struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
1093                 struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
1094                 return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
1095         }
1096         default:
1097                 WARN_ON(1);
1098                 return false; /* don't expect to be here */
1099         }
1100 }
1101
1102 /*
1103  * If no port is specified in addr structure, we try to match with 445 port
1104  * and if it fails - with 139 ports. It should be called only if address
1105  * families of server and addr are equal.
1106  */
1107 static bool
1108 match_port(struct TCP_Server_Info *server, struct sockaddr *addr)
1109 {
1110         __be16 port, *sport;
1111
1112         /* SMBDirect manages its own ports, don't match it here */
1113         if (server->rdma)
1114                 return true;
1115
1116         switch (addr->sa_family) {
1117         case AF_INET:
1118                 sport = &((struct sockaddr_in *) &server->dstaddr)->sin_port;
1119                 port = ((struct sockaddr_in *) addr)->sin_port;
1120                 break;
1121         case AF_INET6:
1122                 sport = &((struct sockaddr_in6 *) &server->dstaddr)->sin6_port;
1123                 port = ((struct sockaddr_in6 *) addr)->sin6_port;
1124                 break;
1125         default:
1126                 WARN_ON(1);
1127                 return false;
1128         }
1129
1130         if (!port) {
1131                 port = htons(CIFS_PORT);
1132                 if (port == *sport)
1133                         return true;
1134
1135                 port = htons(RFC1001_PORT);
1136         }
1137
1138         return port == *sport;
1139 }
1140
1141 static bool
1142 match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
1143               struct sockaddr *srcaddr)
1144 {
1145         switch (addr->sa_family) {
1146         case AF_INET: {
1147                 struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
1148                 struct sockaddr_in *srv_addr4 =
1149                                         (struct sockaddr_in *)&server->dstaddr;
1150
1151                 if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
1152                         return false;
1153                 break;
1154         }
1155         case AF_INET6: {
1156                 struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
1157                 struct sockaddr_in6 *srv_addr6 =
1158                                         (struct sockaddr_in6 *)&server->dstaddr;
1159
1160                 if (!ipv6_addr_equal(&addr6->sin6_addr,
1161                                      &srv_addr6->sin6_addr))
1162                         return false;
1163                 if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
1164                         return false;
1165                 break;
1166         }
1167         default:
1168                 WARN_ON(1);
1169                 return false; /* don't expect to be here */
1170         }
1171
1172         if (!cifs_match_ipaddr(srcaddr, (struct sockaddr *)&server->srcaddr))
1173                 return false;
1174
1175         return true;
1176 }
1177
1178 static bool
1179 match_security(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1180 {
1181         /*
1182          * The select_sectype function should either return the ctx->sectype
1183          * that was specified, or "Unspecified" if that sectype was not
1184          * compatible with the given NEGOTIATE request.
1185          */
1186         if (server->ops->select_sectype(server, ctx->sectype)
1187              == Unspecified)
1188                 return false;
1189
1190         /*
1191          * Now check if signing mode is acceptable. No need to check
1192          * global_secflags at this point since if MUST_SIGN is set then
1193          * the server->sign had better be too.
1194          */
1195         if (ctx->sign && !server->sign)
1196                 return false;
1197
1198         return true;
1199 }
1200
1201 static int match_server(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1202 {
1203         struct sockaddr *addr = (struct sockaddr *)&ctx->dstaddr;
1204
1205         if (ctx->nosharesock)
1206                 return 0;
1207
1208         /* If multidialect negotiation see if existing sessions match one */
1209         if (strcmp(ctx->vals->version_string, SMB3ANY_VERSION_STRING) == 0) {
1210                 if (server->vals->protocol_id < SMB30_PROT_ID)
1211                         return 0;
1212         } else if (strcmp(ctx->vals->version_string,
1213                    SMBDEFAULT_VERSION_STRING) == 0) {
1214                 if (server->vals->protocol_id < SMB21_PROT_ID)
1215                         return 0;
1216         } else if ((server->vals != ctx->vals) || (server->ops != ctx->ops))
1217                 return 0;
1218
1219         if (!net_eq(cifs_net_ns(server), current->nsproxy->net_ns))
1220                 return 0;
1221
1222         if (!match_address(server, addr,
1223                            (struct sockaddr *)&ctx->srcaddr))
1224                 return 0;
1225
1226         if (!match_port(server, addr))
1227                 return 0;
1228
1229         if (!match_security(server, ctx))
1230                 return 0;
1231
1232         if (server->echo_interval != ctx->echo_interval * HZ)
1233                 return 0;
1234
1235         if (server->rdma != ctx->rdma)
1236                 return 0;
1237
1238         if (server->ignore_signature != ctx->ignore_signature)
1239                 return 0;
1240
1241         if (server->min_offload != ctx->min_offload)
1242                 return 0;
1243
1244         return 1;
1245 }
1246
1247 struct TCP_Server_Info *
1248 cifs_find_tcp_session(struct smb3_fs_context *ctx)
1249 {
1250         struct TCP_Server_Info *server;
1251
1252         spin_lock(&cifs_tcp_ses_lock);
1253         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
1254                 /*
1255                  * Skip ses channels since they're only handled in lower layers
1256                  * (e.g. cifs_send_recv).
1257                  */
1258                 if (server->is_channel || !match_server(server, ctx))
1259                         continue;
1260
1261                 ++server->srv_count;
1262                 spin_unlock(&cifs_tcp_ses_lock);
1263                 cifs_dbg(FYI, "Existing tcp session with server found\n");
1264                 return server;
1265         }
1266         spin_unlock(&cifs_tcp_ses_lock);
1267         return NULL;
1268 }
1269
1270 void
1271 cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect)
1272 {
1273         struct task_struct *task;
1274
1275         spin_lock(&cifs_tcp_ses_lock);
1276         if (--server->srv_count > 0) {
1277                 spin_unlock(&cifs_tcp_ses_lock);
1278                 return;
1279         }
1280
1281         put_net(cifs_net_ns(server));
1282
1283         list_del_init(&server->tcp_ses_list);
1284         spin_unlock(&cifs_tcp_ses_lock);
1285
1286         cancel_delayed_work_sync(&server->echo);
1287
1288         if (from_reconnect)
1289                 /*
1290                  * Avoid deadlock here: reconnect work calls
1291                  * cifs_put_tcp_session() at its end. Need to be sure
1292                  * that reconnect work does nothing with server pointer after
1293                  * that step.
1294                  */
1295                 cancel_delayed_work(&server->reconnect);
1296         else
1297                 cancel_delayed_work_sync(&server->reconnect);
1298
1299         spin_lock(&GlobalMid_Lock);
1300         server->tcpStatus = CifsExiting;
1301         spin_unlock(&GlobalMid_Lock);
1302
1303         cifs_crypto_secmech_release(server);
1304         cifs_fscache_release_client_cookie(server);
1305
1306         kfree(server->session_key.response);
1307         server->session_key.response = NULL;
1308         server->session_key.len = 0;
1309
1310         task = xchg(&server->tsk, NULL);
1311         if (task)
1312                 send_sig(SIGKILL, task, 1);
1313 }
1314
1315 struct TCP_Server_Info *
1316 cifs_get_tcp_session(struct smb3_fs_context *ctx)
1317 {
1318         struct TCP_Server_Info *tcp_ses = NULL;
1319         int rc;
1320
1321         cifs_dbg(FYI, "UNC: %s\n", ctx->UNC);
1322
1323         /* see if we already have a matching tcp_ses */
1324         tcp_ses = cifs_find_tcp_session(ctx);
1325         if (tcp_ses)
1326                 return tcp_ses;
1327
1328         tcp_ses = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
1329         if (!tcp_ses) {
1330                 rc = -ENOMEM;
1331                 goto out_err;
1332         }
1333
1334         tcp_ses->ops = ctx->ops;
1335         tcp_ses->vals = ctx->vals;
1336         cifs_set_net_ns(tcp_ses, get_net(current->nsproxy->net_ns));
1337         tcp_ses->hostname = extract_hostname(ctx->UNC);
1338         if (IS_ERR(tcp_ses->hostname)) {
1339                 rc = PTR_ERR(tcp_ses->hostname);
1340                 goto out_err_crypto_release;
1341         }
1342
1343         tcp_ses->conn_id = atomic_inc_return(&tcpSesNextId);
1344         tcp_ses->noblockcnt = ctx->rootfs;
1345         tcp_ses->noblocksnd = ctx->noblocksnd || ctx->rootfs;
1346         tcp_ses->noautotune = ctx->noautotune;
1347         tcp_ses->tcp_nodelay = ctx->sockopt_tcp_nodelay;
1348         tcp_ses->rdma = ctx->rdma;
1349         tcp_ses->in_flight = 0;
1350         tcp_ses->max_in_flight = 0;
1351         tcp_ses->credits = 1;
1352         init_waitqueue_head(&tcp_ses->response_q);
1353         init_waitqueue_head(&tcp_ses->request_q);
1354         INIT_LIST_HEAD(&tcp_ses->pending_mid_q);
1355         mutex_init(&tcp_ses->srv_mutex);
1356         memcpy(tcp_ses->workstation_RFC1001_name,
1357                 ctx->source_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1358         memcpy(tcp_ses->server_RFC1001_name,
1359                 ctx->target_rfc1001_name, RFC1001_NAME_LEN_WITH_NULL);
1360         tcp_ses->session_estab = false;
1361         tcp_ses->sequence_number = 0;
1362         tcp_ses->reconnect_instance = 1;
1363         tcp_ses->lstrp = jiffies;
1364         tcp_ses->compress_algorithm = cpu_to_le16(ctx->compression);
1365         spin_lock_init(&tcp_ses->req_lock);
1366         INIT_LIST_HEAD(&tcp_ses->tcp_ses_list);
1367         INIT_LIST_HEAD(&tcp_ses->smb_ses_list);
1368         INIT_DELAYED_WORK(&tcp_ses->echo, cifs_echo_request);
1369         INIT_DELAYED_WORK(&tcp_ses->reconnect, smb2_reconnect_server);
1370         mutex_init(&tcp_ses->reconnect_mutex);
1371         memcpy(&tcp_ses->srcaddr, &ctx->srcaddr,
1372                sizeof(tcp_ses->srcaddr));
1373         memcpy(&tcp_ses->dstaddr, &ctx->dstaddr,
1374                 sizeof(tcp_ses->dstaddr));
1375         if (ctx->use_client_guid)
1376                 memcpy(tcp_ses->client_guid, ctx->client_guid,
1377                        SMB2_CLIENT_GUID_SIZE);
1378         else
1379                 generate_random_uuid(tcp_ses->client_guid);
1380         /*
1381          * at this point we are the only ones with the pointer
1382          * to the struct since the kernel thread not created yet
1383          * no need to spinlock this init of tcpStatus or srv_count
1384          */
1385         tcp_ses->tcpStatus = CifsNew;
1386         ++tcp_ses->srv_count;
1387
1388         if (ctx->echo_interval >= SMB_ECHO_INTERVAL_MIN &&
1389                 ctx->echo_interval <= SMB_ECHO_INTERVAL_MAX)
1390                 tcp_ses->echo_interval = ctx->echo_interval * HZ;
1391         else
1392                 tcp_ses->echo_interval = SMB_ECHO_INTERVAL_DEFAULT * HZ;
1393         if (tcp_ses->rdma) {
1394 #ifndef CONFIG_CIFS_SMB_DIRECT
1395                 cifs_dbg(VFS, "CONFIG_CIFS_SMB_DIRECT is not enabled\n");
1396                 rc = -ENOENT;
1397                 goto out_err_crypto_release;
1398 #endif
1399                 tcp_ses->smbd_conn = smbd_get_connection(
1400                         tcp_ses, (struct sockaddr *)&ctx->dstaddr);
1401                 if (tcp_ses->smbd_conn) {
1402                         cifs_dbg(VFS, "RDMA transport established\n");
1403                         rc = 0;
1404                         goto smbd_connected;
1405                 } else {
1406                         rc = -ENOENT;
1407                         goto out_err_crypto_release;
1408                 }
1409         }
1410         rc = ip_connect(tcp_ses);
1411         if (rc < 0) {
1412                 cifs_dbg(VFS, "Error connecting to socket. Aborting operation.\n");
1413                 goto out_err_crypto_release;
1414         }
1415 smbd_connected:
1416         /*
1417          * since we're in a cifs function already, we know that
1418          * this will succeed. No need for try_module_get().
1419          */
1420         __module_get(THIS_MODULE);
1421         tcp_ses->tsk = kthread_run(cifs_demultiplex_thread,
1422                                   tcp_ses, "cifsd");
1423         if (IS_ERR(tcp_ses->tsk)) {
1424                 rc = PTR_ERR(tcp_ses->tsk);
1425                 cifs_dbg(VFS, "error %d create cifsd thread\n", rc);
1426                 module_put(THIS_MODULE);
1427                 goto out_err_crypto_release;
1428         }
1429         tcp_ses->min_offload = ctx->min_offload;
1430         tcp_ses->tcpStatus = CifsNeedNegotiate;
1431
1432         if ((ctx->max_credits < 20) || (ctx->max_credits > 60000))
1433                 tcp_ses->max_credits = SMB2_MAX_CREDITS_AVAILABLE;
1434         else
1435                 tcp_ses->max_credits = ctx->max_credits;
1436
1437         tcp_ses->nr_targets = 1;
1438         tcp_ses->ignore_signature = ctx->ignore_signature;
1439         /* thread spawned, put it on the list */
1440         spin_lock(&cifs_tcp_ses_lock);
1441         list_add(&tcp_ses->tcp_ses_list, &cifs_tcp_ses_list);
1442         spin_unlock(&cifs_tcp_ses_lock);
1443
1444         cifs_fscache_get_client_cookie(tcp_ses);
1445
1446         /* queue echo request delayed work */
1447         queue_delayed_work(cifsiod_wq, &tcp_ses->echo, tcp_ses->echo_interval);
1448
1449         return tcp_ses;
1450
1451 out_err_crypto_release:
1452         cifs_crypto_secmech_release(tcp_ses);
1453
1454         put_net(cifs_net_ns(tcp_ses));
1455
1456 out_err:
1457         if (tcp_ses) {
1458                 if (!IS_ERR(tcp_ses->hostname))
1459                         kfree(tcp_ses->hostname);
1460                 if (tcp_ses->ssocket)
1461                         sock_release(tcp_ses->ssocket);
1462                 kfree(tcp_ses);
1463         }
1464         return ERR_PTR(rc);
1465 }
1466
1467 static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1468 {
1469         if (ctx->sectype != Unspecified &&
1470             ctx->sectype != ses->sectype)
1471                 return 0;
1472
1473         /*
1474          * If an existing session is limited to less channels than
1475          * requested, it should not be reused
1476          */
1477         if (ses->chan_max < ctx->max_channels)
1478                 return 0;
1479
1480         switch (ses->sectype) {
1481         case Kerberos:
1482                 if (!uid_eq(ctx->cred_uid, ses->cred_uid))
1483                         return 0;
1484                 break;
1485         default:
1486                 /* NULL username means anonymous session */
1487                 if (ses->user_name == NULL) {
1488                         if (!ctx->nullauth)
1489                                 return 0;
1490                         break;
1491                 }
1492
1493                 /* anything else takes username/password */
1494                 if (strncmp(ses->user_name,
1495                             ctx->username ? ctx->username : "",
1496                             CIFS_MAX_USERNAME_LEN))
1497                         return 0;
1498                 if ((ctx->username && strlen(ctx->username) != 0) &&
1499                     ses->password != NULL &&
1500                     strncmp(ses->password,
1501                             ctx->password ? ctx->password : "",
1502                             CIFS_MAX_PASSWORD_LEN))
1503                         return 0;
1504         }
1505         return 1;
1506 }
1507
1508 /**
1509  * cifs_setup_ipc - helper to setup the IPC tcon for the session
1510  *
1511  * A new IPC connection is made and stored in the session
1512  * tcon_ipc. The IPC tcon has the same lifetime as the session.
1513  */
1514 static int
1515 cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1516 {
1517         int rc = 0, xid;
1518         struct cifs_tcon *tcon;
1519         char unc[SERVER_NAME_LENGTH + sizeof("//x/IPC$")] = {0};
1520         bool seal = false;
1521         struct TCP_Server_Info *server = ses->server;
1522
1523         /*
1524          * If the mount request that resulted in the creation of the
1525          * session requires encryption, force IPC to be encrypted too.
1526          */
1527         if (ctx->seal) {
1528                 if (server->capabilities & SMB2_GLOBAL_CAP_ENCRYPTION)
1529                         seal = true;
1530                 else {
1531                         cifs_server_dbg(VFS,
1532                                  "IPC: server doesn't support encryption\n");
1533                         return -EOPNOTSUPP;
1534                 }
1535         }
1536
1537         tcon = tconInfoAlloc();
1538         if (tcon == NULL)
1539                 return -ENOMEM;
1540
1541         scnprintf(unc, sizeof(unc), "\\\\%s\\IPC$", server->hostname);
1542
1543         xid = get_xid();
1544         tcon->ses = ses;
1545         tcon->ipc = true;
1546         tcon->seal = seal;
1547         rc = server->ops->tree_connect(xid, ses, unc, tcon, ctx->local_nls);
1548         free_xid(xid);
1549
1550         if (rc) {
1551                 cifs_server_dbg(VFS, "failed to connect to IPC (rc=%d)\n", rc);
1552                 tconInfoFree(tcon);
1553                 goto out;
1554         }
1555
1556         cifs_dbg(FYI, "IPC tcon rc = %d ipc tid = %d\n", rc, tcon->tid);
1557
1558         ses->tcon_ipc = tcon;
1559 out:
1560         return rc;
1561 }
1562
1563 /**
1564  * cifs_free_ipc - helper to release the session IPC tcon
1565  *
1566  * Needs to be called everytime a session is destroyed
1567  */
1568 static int
1569 cifs_free_ipc(struct cifs_ses *ses)
1570 {
1571         int rc = 0, xid;
1572         struct cifs_tcon *tcon = ses->tcon_ipc;
1573
1574         if (tcon == NULL)
1575                 return 0;
1576
1577         if (ses->server->ops->tree_disconnect) {
1578                 xid = get_xid();
1579                 rc = ses->server->ops->tree_disconnect(xid, tcon);
1580                 free_xid(xid);
1581         }
1582
1583         if (rc)
1584                 cifs_dbg(FYI, "failed to disconnect IPC tcon (rc=%d)\n", rc);
1585
1586         tconInfoFree(tcon);
1587         ses->tcon_ipc = NULL;
1588         return rc;
1589 }
1590
1591 static struct cifs_ses *
1592 cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1593 {
1594         struct cifs_ses *ses;
1595
1596         spin_lock(&cifs_tcp_ses_lock);
1597         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
1598                 if (ses->status == CifsExiting)
1599                         continue;
1600                 if (!match_session(ses, ctx))
1601                         continue;
1602                 ++ses->ses_count;
1603                 spin_unlock(&cifs_tcp_ses_lock);
1604                 return ses;
1605         }
1606         spin_unlock(&cifs_tcp_ses_lock);
1607         return NULL;
1608 }
1609
1610 void cifs_put_smb_ses(struct cifs_ses *ses)
1611 {
1612         unsigned int rc, xid;
1613         struct TCP_Server_Info *server = ses->server;
1614
1615         cifs_dbg(FYI, "%s: ses_count=%d\n", __func__, ses->ses_count);
1616
1617         spin_lock(&cifs_tcp_ses_lock);
1618         if (ses->status == CifsExiting) {
1619                 spin_unlock(&cifs_tcp_ses_lock);
1620                 return;
1621         }
1622         if (--ses->ses_count > 0) {
1623                 spin_unlock(&cifs_tcp_ses_lock);
1624                 return;
1625         }
1626         if (ses->status == CifsGood)
1627                 ses->status = CifsExiting;
1628         spin_unlock(&cifs_tcp_ses_lock);
1629
1630         cifs_free_ipc(ses);
1631
1632         if (ses->status == CifsExiting && server->ops->logoff) {
1633                 xid = get_xid();
1634                 rc = server->ops->logoff(xid, ses);
1635                 if (rc)
1636                         cifs_server_dbg(VFS, "%s: Session Logoff failure rc=%d\n",
1637                                 __func__, rc);
1638                 _free_xid(xid);
1639         }
1640
1641         spin_lock(&cifs_tcp_ses_lock);
1642         list_del_init(&ses->smb_ses_list);
1643         spin_unlock(&cifs_tcp_ses_lock);
1644
1645         /* close any extra channels */
1646         if (ses->chan_count > 1) {
1647                 int i;
1648
1649                 for (i = 1; i < ses->chan_count; i++)
1650                         cifs_put_tcp_session(ses->chans[i].server, 0);
1651         }
1652
1653         sesInfoFree(ses);
1654         cifs_put_tcp_session(server, 0);
1655 }
1656
1657 #ifdef CONFIG_KEYS
1658
1659 /* strlen("cifs:a:") + CIFS_MAX_DOMAINNAME_LEN + 1 */
1660 #define CIFSCREDS_DESC_SIZE (7 + CIFS_MAX_DOMAINNAME_LEN + 1)
1661
1662 /* Populate username and pw fields from keyring if possible */
1663 static int
1664 cifs_set_cifscreds(struct smb3_fs_context *ctx, struct cifs_ses *ses)
1665 {
1666         int rc = 0;
1667         int is_domain = 0;
1668         const char *delim, *payload;
1669         char *desc;
1670         ssize_t len;
1671         struct key *key;
1672         struct TCP_Server_Info *server = ses->server;
1673         struct sockaddr_in *sa;
1674         struct sockaddr_in6 *sa6;
1675         const struct user_key_payload *upayload;
1676
1677         desc = kmalloc(CIFSCREDS_DESC_SIZE, GFP_KERNEL);
1678         if (!desc)
1679                 return -ENOMEM;
1680
1681         /* try to find an address key first */
1682         switch (server->dstaddr.ss_family) {
1683         case AF_INET:
1684                 sa = (struct sockaddr_in *)&server->dstaddr;
1685                 sprintf(desc, "cifs:a:%pI4", &sa->sin_addr.s_addr);
1686                 break;
1687         case AF_INET6:
1688                 sa6 = (struct sockaddr_in6 *)&server->dstaddr;
1689                 sprintf(desc, "cifs:a:%pI6c", &sa6->sin6_addr.s6_addr);
1690                 break;
1691         default:
1692                 cifs_dbg(FYI, "Bad ss_family (%hu)\n",
1693                          server->dstaddr.ss_family);
1694                 rc = -EINVAL;
1695                 goto out_err;
1696         }
1697
1698         cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1699         key = request_key(&key_type_logon, desc, "");
1700         if (IS_ERR(key)) {
1701                 if (!ses->domainName) {
1702                         cifs_dbg(FYI, "domainName is NULL\n");
1703                         rc = PTR_ERR(key);
1704                         goto out_err;
1705                 }
1706
1707                 /* didn't work, try to find a domain key */
1708                 sprintf(desc, "cifs:d:%s", ses->domainName);
1709                 cifs_dbg(FYI, "%s: desc=%s\n", __func__, desc);
1710                 key = request_key(&key_type_logon, desc, "");
1711                 if (IS_ERR(key)) {
1712                         rc = PTR_ERR(key);
1713                         goto out_err;
1714                 }
1715                 is_domain = 1;
1716         }
1717
1718         down_read(&key->sem);
1719         upayload = user_key_payload_locked(key);
1720         if (IS_ERR_OR_NULL(upayload)) {
1721                 rc = upayload ? PTR_ERR(upayload) : -EINVAL;
1722                 goto out_key_put;
1723         }
1724
1725         /* find first : in payload */
1726         payload = upayload->data;
1727         delim = strnchr(payload, upayload->datalen, ':');
1728         cifs_dbg(FYI, "payload=%s\n", payload);
1729         if (!delim) {
1730                 cifs_dbg(FYI, "Unable to find ':' in payload (datalen=%d)\n",
1731                          upayload->datalen);
1732                 rc = -EINVAL;
1733                 goto out_key_put;
1734         }
1735
1736         len = delim - payload;
1737         if (len > CIFS_MAX_USERNAME_LEN || len <= 0) {
1738                 cifs_dbg(FYI, "Bad value from username search (len=%zd)\n",
1739                          len);
1740                 rc = -EINVAL;
1741                 goto out_key_put;
1742         }
1743
1744         ctx->username = kstrndup(payload, len, GFP_KERNEL);
1745         if (!ctx->username) {
1746                 cifs_dbg(FYI, "Unable to allocate %zd bytes for username\n",
1747                          len);
1748                 rc = -ENOMEM;
1749                 goto out_key_put;
1750         }
1751         cifs_dbg(FYI, "%s: username=%s\n", __func__, ctx->username);
1752
1753         len = key->datalen - (len + 1);
1754         if (len > CIFS_MAX_PASSWORD_LEN || len <= 0) {
1755                 cifs_dbg(FYI, "Bad len for password search (len=%zd)\n", len);
1756                 rc = -EINVAL;
1757                 kfree(ctx->username);
1758                 ctx->username = NULL;
1759                 goto out_key_put;
1760         }
1761
1762         ++delim;
1763         ctx->password = kstrndup(delim, len, GFP_KERNEL);
1764         if (!ctx->password) {
1765                 cifs_dbg(FYI, "Unable to allocate %zd bytes for password\n",
1766                          len);
1767                 rc = -ENOMEM;
1768                 kfree(ctx->username);
1769                 ctx->username = NULL;
1770                 goto out_key_put;
1771         }
1772
1773         /*
1774          * If we have a domain key then we must set the domainName in the
1775          * for the request.
1776          */
1777         if (is_domain && ses->domainName) {
1778                 ctx->domainname = kstrndup(ses->domainName,
1779                                            strlen(ses->domainName),
1780                                            GFP_KERNEL);
1781                 if (!ctx->domainname) {
1782                         cifs_dbg(FYI, "Unable to allocate %zd bytes for domain\n",
1783                                  len);
1784                         rc = -ENOMEM;
1785                         kfree(ctx->username);
1786                         ctx->username = NULL;
1787                         kfree_sensitive(ctx->password);
1788                         ctx->password = NULL;
1789                         goto out_key_put;
1790                 }
1791         }
1792
1793 out_key_put:
1794         up_read(&key->sem);
1795         key_put(key);
1796 out_err:
1797         kfree(desc);
1798         cifs_dbg(FYI, "%s: returning %d\n", __func__, rc);
1799         return rc;
1800 }
1801 #else /* ! CONFIG_KEYS */
1802 static inline int
1803 cifs_set_cifscreds(struct smb3_fs_context *ctx __attribute__((unused)),
1804                    struct cifs_ses *ses __attribute__((unused)))
1805 {
1806         return -ENOSYS;
1807 }
1808 #endif /* CONFIG_KEYS */
1809
1810 /**
1811  * cifs_get_smb_ses - get a session matching @ctx data from @server
1812  *
1813  * This function assumes it is being called from cifs_mount() where we
1814  * already got a server reference (server refcount +1). See
1815  * cifs_get_tcon() for refcount explanations.
1816  */
1817 struct cifs_ses *
1818 cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
1819 {
1820         int rc = -ENOMEM;
1821         unsigned int xid;
1822         struct cifs_ses *ses;
1823         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
1824         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
1825
1826         xid = get_xid();
1827
1828         ses = cifs_find_smb_ses(server, ctx);
1829         if (ses) {
1830                 cifs_dbg(FYI, "Existing smb sess found (status=%d)\n",
1831                          ses->status);
1832
1833                 mutex_lock(&ses->session_mutex);
1834                 rc = cifs_negotiate_protocol(xid, ses);
1835                 if (rc) {
1836                         mutex_unlock(&ses->session_mutex);
1837                         /* problem -- put our ses reference */
1838                         cifs_put_smb_ses(ses);
1839                         free_xid(xid);
1840                         return ERR_PTR(rc);
1841                 }
1842                 if (ses->need_reconnect) {
1843                         cifs_dbg(FYI, "Session needs reconnect\n");
1844                         rc = cifs_setup_session(xid, ses,
1845                                                 ctx->local_nls);
1846                         if (rc) {
1847                                 mutex_unlock(&ses->session_mutex);
1848                                 /* problem -- put our reference */
1849                                 cifs_put_smb_ses(ses);
1850                                 free_xid(xid);
1851                                 return ERR_PTR(rc);
1852                         }
1853                 }
1854                 mutex_unlock(&ses->session_mutex);
1855
1856                 /* existing SMB ses has a server reference already */
1857                 cifs_put_tcp_session(server, 0);
1858                 free_xid(xid);
1859                 return ses;
1860         }
1861
1862         cifs_dbg(FYI, "Existing smb sess not found\n");
1863         ses = sesInfoAlloc();
1864         if (ses == NULL)
1865                 goto get_ses_fail;
1866
1867         /* new SMB session uses our server ref */
1868         ses->server = server;
1869         if (server->dstaddr.ss_family == AF_INET6)
1870                 sprintf(ses->ip_addr, "%pI6", &addr6->sin6_addr);
1871         else
1872                 sprintf(ses->ip_addr, "%pI4", &addr->sin_addr);
1873
1874         if (ctx->username) {
1875                 ses->user_name = kstrdup(ctx->username, GFP_KERNEL);
1876                 if (!ses->user_name)
1877                         goto get_ses_fail;
1878         }
1879
1880         /* ctx->password freed at unmount */
1881         if (ctx->password) {
1882                 ses->password = kstrdup(ctx->password, GFP_KERNEL);
1883                 if (!ses->password)
1884                         goto get_ses_fail;
1885         }
1886         if (ctx->domainname) {
1887                 ses->domainName = kstrdup(ctx->domainname, GFP_KERNEL);
1888                 if (!ses->domainName)
1889                         goto get_ses_fail;
1890         }
1891         if (ctx->domainauto)
1892                 ses->domainAuto = ctx->domainauto;
1893         ses->cred_uid = ctx->cred_uid;
1894         ses->linux_uid = ctx->linux_uid;
1895
1896         ses->sectype = ctx->sectype;
1897         ses->sign = ctx->sign;
1898         mutex_lock(&ses->session_mutex);
1899
1900         /* add server as first channel */
1901         ses->chans[0].server = server;
1902         ses->chan_count = 1;
1903         ses->chan_max = ctx->multichannel ? ctx->max_channels:1;
1904
1905         rc = cifs_negotiate_protocol(xid, ses);
1906         if (!rc)
1907                 rc = cifs_setup_session(xid, ses, ctx->local_nls);
1908
1909         /* each channel uses a different signing key */
1910         memcpy(ses->chans[0].signkey, ses->smb3signingkey,
1911                sizeof(ses->smb3signingkey));
1912
1913         mutex_unlock(&ses->session_mutex);
1914         if (rc)
1915                 goto get_ses_fail;
1916
1917         /* success, put it on the list and add it as first channel */
1918         spin_lock(&cifs_tcp_ses_lock);
1919         list_add(&ses->smb_ses_list, &server->smb_ses_list);
1920         spin_unlock(&cifs_tcp_ses_lock);
1921
1922         free_xid(xid);
1923
1924         cifs_setup_ipc(ses, ctx);
1925
1926         return ses;
1927
1928 get_ses_fail:
1929         sesInfoFree(ses);
1930         free_xid(xid);
1931         return ERR_PTR(rc);
1932 }
1933
1934 static int match_tcon(struct cifs_tcon *tcon, struct smb3_fs_context *ctx)
1935 {
1936         if (tcon->tidStatus == CifsExiting)
1937                 return 0;
1938         if (strncmp(tcon->treeName, ctx->UNC, MAX_TREE_SIZE))
1939                 return 0;
1940         if (tcon->seal != ctx->seal)
1941                 return 0;
1942         if (tcon->snapshot_time != ctx->snapshot_time)
1943                 return 0;
1944         if (tcon->handle_timeout != ctx->handle_timeout)
1945                 return 0;
1946         if (tcon->no_lease != ctx->no_lease)
1947                 return 0;
1948         if (tcon->nodelete != ctx->nodelete)
1949                 return 0;
1950         return 1;
1951 }
1952
1953 static struct cifs_tcon *
1954 cifs_find_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
1955 {
1956         struct list_head *tmp;
1957         struct cifs_tcon *tcon;
1958
1959         spin_lock(&cifs_tcp_ses_lock);
1960         list_for_each(tmp, &ses->tcon_list) {
1961                 tcon = list_entry(tmp, struct cifs_tcon, tcon_list);
1962 #ifdef CONFIG_CIFS_DFS_UPCALL
1963                 if (tcon->dfs_path)
1964                         continue;
1965 #endif
1966                 if (!match_tcon(tcon, ctx))
1967                         continue;
1968                 ++tcon->tc_count;
1969                 spin_unlock(&cifs_tcp_ses_lock);
1970                 return tcon;
1971         }
1972         spin_unlock(&cifs_tcp_ses_lock);
1973         return NULL;
1974 }
1975
1976 void
1977 cifs_put_tcon(struct cifs_tcon *tcon)
1978 {
1979         unsigned int xid;
1980         struct cifs_ses *ses;
1981
1982         /*
1983          * IPC tcon share the lifetime of their session and are
1984          * destroyed in the session put function
1985          */
1986         if (tcon == NULL || tcon->ipc)
1987                 return;
1988
1989         ses = tcon->ses;
1990         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
1991         spin_lock(&cifs_tcp_ses_lock);
1992         if (--tcon->tc_count > 0) {
1993                 spin_unlock(&cifs_tcp_ses_lock);
1994                 return;
1995         }
1996
1997 #ifdef CONFIG_CIFS_SWN_UPCALL
1998         if (tcon->use_witness) {
1999                 int rc;
2000
2001                 rc = cifs_swn_unregister(tcon);
2002                 if (rc < 0) {
2003                         cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
2004                                         __func__, rc);
2005                 }
2006         }
2007 #endif
2008
2009         list_del_init(&tcon->tcon_list);
2010         spin_unlock(&cifs_tcp_ses_lock);
2011
2012         xid = get_xid();
2013         if (ses->server->ops->tree_disconnect)
2014                 ses->server->ops->tree_disconnect(xid, tcon);
2015         _free_xid(xid);
2016
2017         cifs_fscache_release_super_cookie(tcon);
2018         tconInfoFree(tcon);
2019         cifs_put_smb_ses(ses);
2020 }
2021
2022 /**
2023  * cifs_get_tcon - get a tcon matching @ctx data from @ses
2024  *
2025  * - tcon refcount is the number of mount points using the tcon.
2026  * - ses refcount is the number of tcon using the session.
2027  *
2028  * 1. This function assumes it is being called from cifs_mount() where
2029  *    we already got a session reference (ses refcount +1).
2030  *
2031  * 2. Since we're in the context of adding a mount point, the end
2032  *    result should be either:
2033  *
2034  * a) a new tcon already allocated with refcount=1 (1 mount point) and
2035  *    its session refcount incremented (1 new tcon). This +1 was
2036  *    already done in (1).
2037  *
2038  * b) an existing tcon with refcount+1 (add a mount point to it) and
2039  *    identical ses refcount (no new tcon). Because of (1) we need to
2040  *    decrement the ses refcount.
2041  */
2042 static struct cifs_tcon *
2043 cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
2044 {
2045         int rc, xid;
2046         struct cifs_tcon *tcon;
2047
2048         tcon = cifs_find_tcon(ses, ctx);
2049         if (tcon) {
2050                 /*
2051                  * tcon has refcount already incremented but we need to
2052                  * decrement extra ses reference gotten by caller (case b)
2053                  */
2054                 cifs_dbg(FYI, "Found match on UNC path\n");
2055                 cifs_put_smb_ses(ses);
2056                 return tcon;
2057         }
2058
2059         if (!ses->server->ops->tree_connect) {
2060                 rc = -ENOSYS;
2061                 goto out_fail;
2062         }
2063
2064         tcon = tconInfoAlloc();
2065         if (tcon == NULL) {
2066                 rc = -ENOMEM;
2067                 goto out_fail;
2068         }
2069
2070         if (ctx->snapshot_time) {
2071                 if (ses->server->vals->protocol_id == 0) {
2072                         cifs_dbg(VFS,
2073                              "Use SMB2 or later for snapshot mount option\n");
2074                         rc = -EOPNOTSUPP;
2075                         goto out_fail;
2076                 } else
2077                         tcon->snapshot_time = ctx->snapshot_time;
2078         }
2079
2080         if (ctx->handle_timeout) {
2081                 if (ses->server->vals->protocol_id == 0) {
2082                         cifs_dbg(VFS,
2083                              "Use SMB2.1 or later for handle timeout option\n");
2084                         rc = -EOPNOTSUPP;
2085                         goto out_fail;
2086                 } else
2087                         tcon->handle_timeout = ctx->handle_timeout;
2088         }
2089
2090         tcon->ses = ses;
2091         if (ctx->password) {
2092                 tcon->password = kstrdup(ctx->password, GFP_KERNEL);
2093                 if (!tcon->password) {
2094                         rc = -ENOMEM;
2095                         goto out_fail;
2096                 }
2097         }
2098
2099         if (ctx->seal) {
2100                 if (ses->server->vals->protocol_id == 0) {
2101                         cifs_dbg(VFS,
2102                                  "SMB3 or later required for encryption\n");
2103                         rc = -EOPNOTSUPP;
2104                         goto out_fail;
2105                 } else if (tcon->ses->server->capabilities &
2106                                         SMB2_GLOBAL_CAP_ENCRYPTION)
2107                         tcon->seal = true;
2108                 else {
2109                         cifs_dbg(VFS, "Encryption is not supported on share\n");
2110                         rc = -EOPNOTSUPP;
2111                         goto out_fail;
2112                 }
2113         }
2114
2115         if (ctx->linux_ext) {
2116                 if (ses->server->posix_ext_supported) {
2117                         tcon->posix_extensions = true;
2118                         pr_warn_once("SMB3.11 POSIX Extensions are experimental\n");
2119                 } else {
2120                         cifs_dbg(VFS, "Server does not support mounting with posix SMB3.11 extensions\n");
2121                         rc = -EOPNOTSUPP;
2122                         goto out_fail;
2123                 }
2124         }
2125
2126         /*
2127          * BB Do we need to wrap session_mutex around this TCon call and Unix
2128          * SetFS as we do on SessSetup and reconnect?
2129          */
2130         xid = get_xid();
2131         rc = ses->server->ops->tree_connect(xid, ses, ctx->UNC, tcon,
2132                                             ctx->local_nls);
2133         free_xid(xid);
2134         cifs_dbg(FYI, "Tcon rc = %d\n", rc);
2135         if (rc)
2136                 goto out_fail;
2137
2138         tcon->use_persistent = false;
2139         /* check if SMB2 or later, CIFS does not support persistent handles */
2140         if (ctx->persistent) {
2141                 if (ses->server->vals->protocol_id == 0) {
2142                         cifs_dbg(VFS,
2143                              "SMB3 or later required for persistent handles\n");
2144                         rc = -EOPNOTSUPP;
2145                         goto out_fail;
2146                 } else if (ses->server->capabilities &
2147                            SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2148                         tcon->use_persistent = true;
2149                 else /* persistent handles requested but not supported */ {
2150                         cifs_dbg(VFS,
2151                                 "Persistent handles not supported on share\n");
2152                         rc = -EOPNOTSUPP;
2153                         goto out_fail;
2154                 }
2155         } else if ((tcon->capabilities & SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY)
2156              && (ses->server->capabilities & SMB2_GLOBAL_CAP_PERSISTENT_HANDLES)
2157              && (ctx->nopersistent == false)) {
2158                 cifs_dbg(FYI, "enabling persistent handles\n");
2159                 tcon->use_persistent = true;
2160         } else if (ctx->resilient) {
2161                 if (ses->server->vals->protocol_id == 0) {
2162                         cifs_dbg(VFS,
2163                              "SMB2.1 or later required for resilient handles\n");
2164                         rc = -EOPNOTSUPP;
2165                         goto out_fail;
2166                 }
2167                 tcon->use_resilient = true;
2168         }
2169 #ifdef CONFIG_CIFS_SWN_UPCALL
2170         tcon->use_witness = false;
2171         if (ctx->witness) {
2172                 if (ses->server->vals->protocol_id >= SMB30_PROT_ID) {
2173                         if (tcon->capabilities & SMB2_SHARE_CAP_CLUSTER) {
2174                                 /*
2175                                  * Set witness in use flag in first place
2176                                  * to retry registration in the echo task
2177                                  */
2178                                 tcon->use_witness = true;
2179                                 /* And try to register immediately */
2180                                 rc = cifs_swn_register(tcon);
2181                                 if (rc < 0) {
2182                                         cifs_dbg(VFS, "Failed to register for witness notifications: %d\n", rc);
2183                                         goto out_fail;
2184                                 }
2185                         } else {
2186                                 /* TODO: try to extend for non-cluster uses (eg multichannel) */
2187                                 cifs_dbg(VFS, "witness requested on mount but no CLUSTER capability on share\n");
2188                                 rc = -EOPNOTSUPP;
2189                                 goto out_fail;
2190                         }
2191                 } else {
2192                         cifs_dbg(VFS, "SMB3 or later required for witness option\n");
2193                         rc = -EOPNOTSUPP;
2194                         goto out_fail;
2195                 }
2196         }
2197 #endif
2198
2199         /* If the user really knows what they are doing they can override */
2200         if (tcon->share_flags & SMB2_SHAREFLAG_NO_CACHING) {
2201                 if (ctx->cache_ro)
2202                         cifs_dbg(VFS, "cache=ro requested on mount but NO_CACHING flag set on share\n");
2203                 else if (ctx->cache_rw)
2204                         cifs_dbg(VFS, "cache=singleclient requested on mount but NO_CACHING flag set on share\n");
2205         }
2206
2207         if (ctx->no_lease) {
2208                 if (ses->server->vals->protocol_id == 0) {
2209                         cifs_dbg(VFS,
2210                                 "SMB2 or later required for nolease option\n");
2211                         rc = -EOPNOTSUPP;
2212                         goto out_fail;
2213                 } else
2214                         tcon->no_lease = ctx->no_lease;
2215         }
2216
2217         /*
2218          * We can have only one retry value for a connection to a share so for
2219          * resources mounted more than once to the same server share the last
2220          * value passed in for the retry flag is used.
2221          */
2222         tcon->retry = ctx->retry;
2223         tcon->nocase = ctx->nocase;
2224         if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
2225                 tcon->nohandlecache = ctx->nohandlecache;
2226         else
2227                 tcon->nohandlecache = true;
2228         tcon->nodelete = ctx->nodelete;
2229         tcon->local_lease = ctx->local_lease;
2230         INIT_LIST_HEAD(&tcon->pending_opens);
2231
2232         spin_lock(&cifs_tcp_ses_lock);
2233         list_add(&tcon->tcon_list, &ses->tcon_list);
2234         spin_unlock(&cifs_tcp_ses_lock);
2235
2236         cifs_fscache_get_super_cookie(tcon);
2237
2238         return tcon;
2239
2240 out_fail:
2241         tconInfoFree(tcon);
2242         return ERR_PTR(rc);
2243 }
2244
2245 void
2246 cifs_put_tlink(struct tcon_link *tlink)
2247 {
2248         if (!tlink || IS_ERR(tlink))
2249                 return;
2250
2251         if (!atomic_dec_and_test(&tlink->tl_count) ||
2252             test_bit(TCON_LINK_IN_TREE, &tlink->tl_flags)) {
2253                 tlink->tl_time = jiffies;
2254                 return;
2255         }
2256
2257         if (!IS_ERR(tlink_tcon(tlink)))
2258                 cifs_put_tcon(tlink_tcon(tlink));
2259         kfree(tlink);
2260         return;
2261 }
2262
2263 static int
2264 compare_mount_options(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2265 {
2266         struct cifs_sb_info *old = CIFS_SB(sb);
2267         struct cifs_sb_info *new = mnt_data->cifs_sb;
2268         unsigned int oldflags = old->mnt_cifs_flags & CIFS_MOUNT_MASK;
2269         unsigned int newflags = new->mnt_cifs_flags & CIFS_MOUNT_MASK;
2270
2271         if ((sb->s_flags & CIFS_MS_MASK) != (mnt_data->flags & CIFS_MS_MASK))
2272                 return 0;
2273
2274         if (old->mnt_cifs_serverino_autodisabled)
2275                 newflags &= ~CIFS_MOUNT_SERVER_INUM;
2276
2277         if (oldflags != newflags)
2278                 return 0;
2279
2280         /*
2281          * We want to share sb only if we don't specify an r/wsize or
2282          * specified r/wsize is greater than or equal to existing one.
2283          */
2284         if (new->ctx->wsize && new->ctx->wsize < old->ctx->wsize)
2285                 return 0;
2286
2287         if (new->ctx->rsize && new->ctx->rsize < old->ctx->rsize)
2288                 return 0;
2289
2290         if (!uid_eq(old->ctx->linux_uid, new->ctx->linux_uid) ||
2291             !gid_eq(old->ctx->linux_gid, new->ctx->linux_gid))
2292                 return 0;
2293
2294         if (old->ctx->file_mode != new->ctx->file_mode ||
2295             old->ctx->dir_mode != new->ctx->dir_mode)
2296                 return 0;
2297
2298         if (strcmp(old->local_nls->charset, new->local_nls->charset))
2299                 return 0;
2300
2301         if (old->ctx->acregmax != new->ctx->acregmax)
2302                 return 0;
2303         if (old->ctx->acdirmax != new->ctx->acdirmax)
2304                 return 0;
2305
2306         return 1;
2307 }
2308
2309 static int
2310 match_prepath(struct super_block *sb, struct cifs_mnt_data *mnt_data)
2311 {
2312         struct cifs_sb_info *old = CIFS_SB(sb);
2313         struct cifs_sb_info *new = mnt_data->cifs_sb;
2314         bool old_set = (old->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2315                 old->prepath;
2316         bool new_set = (new->mnt_cifs_flags & CIFS_MOUNT_USE_PREFIX_PATH) &&
2317                 new->prepath;
2318
2319         if (old_set && new_set && !strcmp(new->prepath, old->prepath))
2320                 return 1;
2321         else if (!old_set && !new_set)
2322                 return 1;
2323
2324         return 0;
2325 }
2326
2327 int
2328 cifs_match_super(struct super_block *sb, void *data)
2329 {
2330         struct cifs_mnt_data *mnt_data = (struct cifs_mnt_data *)data;
2331         struct smb3_fs_context *ctx;
2332         struct cifs_sb_info *cifs_sb;
2333         struct TCP_Server_Info *tcp_srv;
2334         struct cifs_ses *ses;
2335         struct cifs_tcon *tcon;
2336         struct tcon_link *tlink;
2337         int rc = 0;
2338
2339         spin_lock(&cifs_tcp_ses_lock);
2340         cifs_sb = CIFS_SB(sb);
2341         tlink = cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
2342         if (IS_ERR(tlink)) {
2343                 spin_unlock(&cifs_tcp_ses_lock);
2344                 return rc;
2345         }
2346         tcon = tlink_tcon(tlink);
2347         ses = tcon->ses;
2348         tcp_srv = ses->server;
2349
2350         ctx = mnt_data->ctx;
2351
2352         if (!match_server(tcp_srv, ctx) ||
2353             !match_session(ses, ctx) ||
2354             !match_tcon(tcon, ctx) ||
2355             !match_prepath(sb, mnt_data)) {
2356                 rc = 0;
2357                 goto out;
2358         }
2359
2360         rc = compare_mount_options(sb, mnt_data);
2361 out:
2362         spin_unlock(&cifs_tcp_ses_lock);
2363         cifs_put_tlink(tlink);
2364         return rc;
2365 }
2366
2367 #ifdef CONFIG_DEBUG_LOCK_ALLOC
2368 static struct lock_class_key cifs_key[2];
2369 static struct lock_class_key cifs_slock_key[2];
2370
2371 static inline void
2372 cifs_reclassify_socket4(struct socket *sock)
2373 {
2374         struct sock *sk = sock->sk;
2375         BUG_ON(!sock_allow_reclassification(sk));
2376         sock_lock_init_class_and_name(sk, "slock-AF_INET-CIFS",
2377                 &cifs_slock_key[0], "sk_lock-AF_INET-CIFS", &cifs_key[0]);
2378 }
2379
2380 static inline void
2381 cifs_reclassify_socket6(struct socket *sock)
2382 {
2383         struct sock *sk = sock->sk;
2384         BUG_ON(!sock_allow_reclassification(sk));
2385         sock_lock_init_class_and_name(sk, "slock-AF_INET6-CIFS",
2386                 &cifs_slock_key[1], "sk_lock-AF_INET6-CIFS", &cifs_key[1]);
2387 }
2388 #else
2389 static inline void
2390 cifs_reclassify_socket4(struct socket *sock)
2391 {
2392 }
2393
2394 static inline void
2395 cifs_reclassify_socket6(struct socket *sock)
2396 {
2397 }
2398 #endif
2399
2400 /* See RFC1001 section 14 on representation of Netbios names */
2401 static void rfc1002mangle(char *target, char *source, unsigned int length)
2402 {
2403         unsigned int i, j;
2404
2405         for (i = 0, j = 0; i < (length); i++) {
2406                 /* mask a nibble at a time and encode */
2407                 target[j] = 'A' + (0x0F & (source[i] >> 4));
2408                 target[j+1] = 'A' + (0x0F & source[i]);
2409                 j += 2;
2410         }
2411
2412 }
2413
2414 static int
2415 bind_socket(struct TCP_Server_Info *server)
2416 {
2417         int rc = 0;
2418         if (server->srcaddr.ss_family != AF_UNSPEC) {
2419                 /* Bind to the specified local IP address */
2420                 struct socket *socket = server->ssocket;
2421                 rc = socket->ops->bind(socket,
2422                                        (struct sockaddr *) &server->srcaddr,
2423                                        sizeof(server->srcaddr));
2424                 if (rc < 0) {
2425                         struct sockaddr_in *saddr4;
2426                         struct sockaddr_in6 *saddr6;
2427                         saddr4 = (struct sockaddr_in *)&server->srcaddr;
2428                         saddr6 = (struct sockaddr_in6 *)&server->srcaddr;
2429                         if (saddr6->sin6_family == AF_INET6)
2430                                 cifs_server_dbg(VFS, "Failed to bind to: %pI6c, error: %d\n",
2431                                          &saddr6->sin6_addr, rc);
2432                         else
2433                                 cifs_server_dbg(VFS, "Failed to bind to: %pI4, error: %d\n",
2434                                          &saddr4->sin_addr.s_addr, rc);
2435                 }
2436         }
2437         return rc;
2438 }
2439
2440 static int
2441 ip_rfc1001_connect(struct TCP_Server_Info *server)
2442 {
2443         int rc = 0;
2444         /*
2445          * some servers require RFC1001 sessinit before sending
2446          * negprot - BB check reconnection in case where second
2447          * sessinit is sent but no second negprot
2448          */
2449         struct rfc1002_session_packet *ses_init_buf;
2450         struct smb_hdr *smb_buf;
2451         ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
2452                                GFP_KERNEL);
2453         if (ses_init_buf) {
2454                 ses_init_buf->trailer.session_req.called_len = 32;
2455
2456                 if (server->server_RFC1001_name[0] != 0)
2457                         rfc1002mangle(ses_init_buf->trailer.
2458                                       session_req.called_name,
2459                                       server->server_RFC1001_name,
2460                                       RFC1001_NAME_LEN_WITH_NULL);
2461                 else
2462                         rfc1002mangle(ses_init_buf->trailer.
2463                                       session_req.called_name,
2464                                       DEFAULT_CIFS_CALLED_NAME,
2465                                       RFC1001_NAME_LEN_WITH_NULL);
2466
2467                 ses_init_buf->trailer.session_req.calling_len = 32;
2468
2469                 /*
2470                  * calling name ends in null (byte 16) from old smb
2471                  * convention.
2472                  */
2473                 if (server->workstation_RFC1001_name[0] != 0)
2474                         rfc1002mangle(ses_init_buf->trailer.
2475                                       session_req.calling_name,
2476                                       server->workstation_RFC1001_name,
2477                                       RFC1001_NAME_LEN_WITH_NULL);
2478                 else
2479                         rfc1002mangle(ses_init_buf->trailer.
2480                                       session_req.calling_name,
2481                                       "LINUX_CIFS_CLNT",
2482                                       RFC1001_NAME_LEN_WITH_NULL);
2483
2484                 ses_init_buf->trailer.session_req.scope1 = 0;
2485                 ses_init_buf->trailer.session_req.scope2 = 0;
2486                 smb_buf = (struct smb_hdr *)ses_init_buf;
2487
2488                 /* sizeof RFC1002_SESSION_REQUEST with no scope */
2489                 smb_buf->smb_buf_length = cpu_to_be32(0x81000044);
2490                 rc = smb_send(server, smb_buf, 0x44);
2491                 kfree(ses_init_buf);
2492                 /*
2493                  * RFC1001 layer in at least one server
2494                  * requires very short break before negprot
2495                  * presumably because not expecting negprot
2496                  * to follow so fast.  This is a simple
2497                  * solution that works without
2498                  * complicating the code and causes no
2499                  * significant slowing down on mount
2500                  * for everyone else
2501                  */
2502                 usleep_range(1000, 2000);
2503         }
2504         /*
2505          * else the negprot may still work without this
2506          * even though malloc failed
2507          */
2508
2509         return rc;
2510 }
2511
2512 static int
2513 generic_ip_connect(struct TCP_Server_Info *server)
2514 {
2515         int rc = 0;
2516         __be16 sport;
2517         int slen, sfamily;
2518         struct socket *socket = server->ssocket;
2519         struct sockaddr *saddr;
2520
2521         saddr = (struct sockaddr *) &server->dstaddr;
2522
2523         if (server->dstaddr.ss_family == AF_INET6) {
2524                 struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&server->dstaddr;
2525
2526                 sport = ipv6->sin6_port;
2527                 slen = sizeof(struct sockaddr_in6);
2528                 sfamily = AF_INET6;
2529                 cifs_dbg(FYI, "%s: connecting to [%pI6]:%d\n", __func__, &ipv6->sin6_addr,
2530                                 ntohs(sport));
2531         } else {
2532                 struct sockaddr_in *ipv4 = (struct sockaddr_in *)&server->dstaddr;
2533
2534                 sport = ipv4->sin_port;
2535                 slen = sizeof(struct sockaddr_in);
2536                 sfamily = AF_INET;
2537                 cifs_dbg(FYI, "%s: connecting to %pI4:%d\n", __func__, &ipv4->sin_addr,
2538                                 ntohs(sport));
2539         }
2540
2541         if (socket == NULL) {
2542                 rc = __sock_create(cifs_net_ns(server), sfamily, SOCK_STREAM,
2543                                    IPPROTO_TCP, &socket, 1);
2544                 if (rc < 0) {
2545                         cifs_server_dbg(VFS, "Error %d creating socket\n", rc);
2546                         server->ssocket = NULL;
2547                         return rc;
2548                 }
2549
2550                 /* BB other socket options to set KEEPALIVE, NODELAY? */
2551                 cifs_dbg(FYI, "Socket created\n");
2552                 server->ssocket = socket;
2553                 socket->sk->sk_allocation = GFP_NOFS;
2554                 if (sfamily == AF_INET6)
2555                         cifs_reclassify_socket6(socket);
2556                 else
2557                         cifs_reclassify_socket4(socket);
2558         }
2559
2560         rc = bind_socket(server);
2561         if (rc < 0)
2562                 return rc;
2563
2564         /*
2565          * Eventually check for other socket options to change from
2566          * the default. sock_setsockopt not used because it expects
2567          * user space buffer
2568          */
2569         socket->sk->sk_rcvtimeo = 7 * HZ;
2570         socket->sk->sk_sndtimeo = 5 * HZ;
2571
2572         /* make the bufsizes depend on wsize/rsize and max requests */
2573         if (server->noautotune) {
2574                 if (socket->sk->sk_sndbuf < (200 * 1024))
2575                         socket->sk->sk_sndbuf = 200 * 1024;
2576                 if (socket->sk->sk_rcvbuf < (140 * 1024))
2577                         socket->sk->sk_rcvbuf = 140 * 1024;
2578         }
2579
2580         if (server->tcp_nodelay)
2581                 tcp_sock_set_nodelay(socket->sk);
2582
2583         cifs_dbg(FYI, "sndbuf %d rcvbuf %d rcvtimeo 0x%lx\n",
2584                  socket->sk->sk_sndbuf,
2585                  socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
2586
2587         rc = socket->ops->connect(socket, saddr, slen,
2588                                   server->noblockcnt ? O_NONBLOCK : 0);
2589         /*
2590          * When mounting SMB root file systems, we do not want to block in
2591          * connect. Otherwise bail out and then let cifs_reconnect() perform
2592          * reconnect failover - if possible.
2593          */
2594         if (server->noblockcnt && rc == -EINPROGRESS)
2595                 rc = 0;
2596         if (rc < 0) {
2597                 cifs_dbg(FYI, "Error %d connecting to server\n", rc);
2598                 sock_release(socket);
2599                 server->ssocket = NULL;
2600                 return rc;
2601         }
2602
2603         if (sport == htons(RFC1001_PORT))
2604                 rc = ip_rfc1001_connect(server);
2605
2606         return rc;
2607 }
2608
2609 static int
2610 ip_connect(struct TCP_Server_Info *server)
2611 {
2612         __be16 *sport;
2613         struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)&server->dstaddr;
2614         struct sockaddr_in *addr = (struct sockaddr_in *)&server->dstaddr;
2615
2616         if (server->dstaddr.ss_family == AF_INET6)
2617                 sport = &addr6->sin6_port;
2618         else
2619                 sport = &addr->sin_port;
2620
2621         if (*sport == 0) {
2622                 int rc;
2623
2624                 /* try with 445 port at first */
2625                 *sport = htons(CIFS_PORT);
2626
2627                 rc = generic_ip_connect(server);
2628                 if (rc >= 0)
2629                         return rc;
2630
2631                 /* if it failed, try with 139 port */
2632                 *sport = htons(RFC1001_PORT);
2633         }
2634
2635         return generic_ip_connect(server);
2636 }
2637
2638 void reset_cifs_unix_caps(unsigned int xid, struct cifs_tcon *tcon,
2639                           struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
2640 {
2641         /*
2642          * If we are reconnecting then should we check to see if
2643          * any requested capabilities changed locally e.g. via
2644          * remount but we can not do much about it here
2645          * if they have (even if we could detect it by the following)
2646          * Perhaps we could add a backpointer to array of sb from tcon
2647          * or if we change to make all sb to same share the same
2648          * sb as NFS - then we only have one backpointer to sb.
2649          * What if we wanted to mount the server share twice once with
2650          * and once without posixacls or posix paths?
2651          */
2652         __u64 saved_cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2653
2654         if (ctx && ctx->no_linux_ext) {
2655                 tcon->fsUnixInfo.Capability = 0;
2656                 tcon->unix_ext = 0; /* Unix Extensions disabled */
2657                 cifs_dbg(FYI, "Linux protocol extensions disabled\n");
2658                 return;
2659         } else if (ctx)
2660                 tcon->unix_ext = 1; /* Unix Extensions supported */
2661
2662         if (!tcon->unix_ext) {
2663                 cifs_dbg(FYI, "Unix extensions disabled so not set on reconnect\n");
2664                 return;
2665         }
2666
2667         if (!CIFSSMBQFSUnixInfo(xid, tcon)) {
2668                 __u64 cap = le64_to_cpu(tcon->fsUnixInfo.Capability);
2669                 cifs_dbg(FYI, "unix caps which server supports %lld\n", cap);
2670                 /*
2671                  * check for reconnect case in which we do not
2672                  * want to change the mount behavior if we can avoid it
2673                  */
2674                 if (ctx == NULL) {
2675                         /*
2676                          * turn off POSIX ACL and PATHNAMES if not set
2677                          * originally at mount time
2678                          */
2679                         if ((saved_cap & CIFS_UNIX_POSIX_ACL_CAP) == 0)
2680                                 cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2681                         if ((saved_cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2682                                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2683                                         cifs_dbg(VFS, "POSIXPATH support change\n");
2684                                 cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2685                         } else if ((cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) == 0) {
2686                                 cifs_dbg(VFS, "possible reconnect error\n");
2687                                 cifs_dbg(VFS, "server disabled POSIX path support\n");
2688                         }
2689                 }
2690
2691                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2692                         cifs_dbg(VFS, "per-share encryption not supported yet\n");
2693
2694                 cap &= CIFS_UNIX_CAP_MASK;
2695                 if (ctx && ctx->no_psx_acl)
2696                         cap &= ~CIFS_UNIX_POSIX_ACL_CAP;
2697                 else if (CIFS_UNIX_POSIX_ACL_CAP & cap) {
2698                         cifs_dbg(FYI, "negotiated posix acl support\n");
2699                         if (cifs_sb)
2700                                 cifs_sb->mnt_cifs_flags |=
2701                                         CIFS_MOUNT_POSIXACL;
2702                 }
2703
2704                 if (ctx && ctx->posix_paths == 0)
2705                         cap &= ~CIFS_UNIX_POSIX_PATHNAMES_CAP;
2706                 else if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP) {
2707                         cifs_dbg(FYI, "negotiate posix pathnames\n");
2708                         if (cifs_sb)
2709                                 cifs_sb->mnt_cifs_flags |=
2710                                         CIFS_MOUNT_POSIX_PATHS;
2711                 }
2712
2713                 cifs_dbg(FYI, "Negotiate caps 0x%x\n", (int)cap);
2714 #ifdef CONFIG_CIFS_DEBUG2
2715                 if (cap & CIFS_UNIX_FCNTL_CAP)
2716                         cifs_dbg(FYI, "FCNTL cap\n");
2717                 if (cap & CIFS_UNIX_EXTATTR_CAP)
2718                         cifs_dbg(FYI, "EXTATTR cap\n");
2719                 if (cap & CIFS_UNIX_POSIX_PATHNAMES_CAP)
2720                         cifs_dbg(FYI, "POSIX path cap\n");
2721                 if (cap & CIFS_UNIX_XATTR_CAP)
2722                         cifs_dbg(FYI, "XATTR cap\n");
2723                 if (cap & CIFS_UNIX_POSIX_ACL_CAP)
2724                         cifs_dbg(FYI, "POSIX ACL cap\n");
2725                 if (cap & CIFS_UNIX_LARGE_READ_CAP)
2726                         cifs_dbg(FYI, "very large read cap\n");
2727                 if (cap & CIFS_UNIX_LARGE_WRITE_CAP)
2728                         cifs_dbg(FYI, "very large write cap\n");
2729                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_CAP)
2730                         cifs_dbg(FYI, "transport encryption cap\n");
2731                 if (cap & CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP)
2732                         cifs_dbg(FYI, "mandatory transport encryption cap\n");
2733 #endif /* CIFS_DEBUG2 */
2734                 if (CIFSSMBSetFSUnixInfo(xid, tcon, cap)) {
2735                         if (ctx == NULL)
2736                                 cifs_dbg(FYI, "resetting capabilities failed\n");
2737                         else
2738                                 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");
2739
2740                 }
2741         }
2742 }
2743
2744 int cifs_setup_cifs_sb(struct cifs_sb_info *cifs_sb)
2745 {
2746         struct smb3_fs_context *ctx = cifs_sb->ctx;
2747
2748         INIT_DELAYED_WORK(&cifs_sb->prune_tlinks, cifs_prune_tlinks);
2749
2750         spin_lock_init(&cifs_sb->tlink_tree_lock);
2751         cifs_sb->tlink_tree = RB_ROOT;
2752
2753         cifs_dbg(FYI, "file mode: %04ho  dir mode: %04ho\n",
2754                  ctx->file_mode, ctx->dir_mode);
2755
2756         /* this is needed for ASCII cp to Unicode converts */
2757         if (ctx->iocharset == NULL) {
2758                 /* load_nls_default cannot return null */
2759                 cifs_sb->local_nls = load_nls_default();
2760         } else {
2761                 cifs_sb->local_nls = load_nls(ctx->iocharset);
2762                 if (cifs_sb->local_nls == NULL) {
2763                         cifs_dbg(VFS, "CIFS mount error: iocharset %s not found\n",
2764                                  ctx->iocharset);
2765                         return -ELIBACC;
2766                 }
2767         }
2768         ctx->local_nls = cifs_sb->local_nls;
2769
2770         smb3_update_mnt_flags(cifs_sb);
2771
2772         if (ctx->direct_io)
2773                 cifs_dbg(FYI, "mounting share using direct i/o\n");
2774         if (ctx->cache_ro) {
2775                 cifs_dbg(VFS, "mounting share with read only caching. Ensure that the share will not be modified while in use.\n");
2776                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_RO_CACHE;
2777         } else if (ctx->cache_rw) {
2778                 cifs_dbg(VFS, "mounting share in single client RW caching mode. Ensure that no other systems will be accessing the share.\n");
2779                 cifs_sb->mnt_cifs_flags |= (CIFS_MOUNT_RO_CACHE |
2780                                             CIFS_MOUNT_RW_CACHE);
2781         }
2782
2783         if ((ctx->cifs_acl) && (ctx->dynperm))
2784                 cifs_dbg(VFS, "mount option dynperm ignored if cifsacl mount option supported\n");
2785
2786         if (ctx->prepath) {
2787                 cifs_sb->prepath = kstrdup(ctx->prepath, GFP_KERNEL);
2788                 if (cifs_sb->prepath == NULL)
2789                         return -ENOMEM;
2790                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
2791         }
2792
2793         return 0;
2794 }
2795
2796 /* Release all succeed connections */
2797 static inline void mount_put_conns(struct cifs_sb_info *cifs_sb,
2798                                    unsigned int xid,
2799                                    struct TCP_Server_Info *server,
2800                                    struct cifs_ses *ses, struct cifs_tcon *tcon)
2801 {
2802         int rc = 0;
2803
2804         if (tcon)
2805                 cifs_put_tcon(tcon);
2806         else if (ses)
2807                 cifs_put_smb_ses(ses);
2808         else if (server)
2809                 cifs_put_tcp_session(server, 0);
2810         cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_POSIX_PATHS;
2811         free_xid(xid);
2812 }
2813
2814 /* Get connections for tcp, ses and tcon */
2815 static int mount_get_conns(struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
2816                            unsigned int *xid,
2817                            struct TCP_Server_Info **nserver,
2818                            struct cifs_ses **nses, struct cifs_tcon **ntcon)
2819 {
2820         int rc = 0;
2821         struct TCP_Server_Info *server;
2822         struct cifs_ses *ses;
2823         struct cifs_tcon *tcon;
2824
2825         *nserver = NULL;
2826         *nses = NULL;
2827         *ntcon = NULL;
2828
2829         *xid = get_xid();
2830
2831         /* get a reference to a tcp session */
2832         server = cifs_get_tcp_session(ctx);
2833         if (IS_ERR(server)) {
2834                 rc = PTR_ERR(server);
2835                 return rc;
2836         }
2837
2838         *nserver = server;
2839
2840         /* get a reference to a SMB session */
2841         ses = cifs_get_smb_ses(server, ctx);
2842         if (IS_ERR(ses)) {
2843                 rc = PTR_ERR(ses);
2844                 return rc;
2845         }
2846
2847         *nses = ses;
2848
2849         if ((ctx->persistent == true) && (!(ses->server->capabilities &
2850                                             SMB2_GLOBAL_CAP_PERSISTENT_HANDLES))) {
2851                 cifs_server_dbg(VFS, "persistent handles not supported by server\n");
2852                 return -EOPNOTSUPP;
2853         }
2854
2855         /* search for existing tcon to this server share */
2856         tcon = cifs_get_tcon(ses, ctx);
2857         if (IS_ERR(tcon)) {
2858                 rc = PTR_ERR(tcon);
2859                 return rc;
2860         }
2861
2862         *ntcon = tcon;
2863
2864         /* if new SMB3.11 POSIX extensions are supported do not remap / and \ */
2865         if (tcon->posix_extensions)
2866                 cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_POSIX_PATHS;
2867
2868         /* tell server which Unix caps we support */
2869         if (cap_unix(tcon->ses)) {
2870                 /*
2871                  * reset of caps checks mount to see if unix extensions disabled
2872                  * for just this mount.
2873                  */
2874                 reset_cifs_unix_caps(*xid, tcon, cifs_sb, ctx);
2875                 if ((tcon->ses->server->tcpStatus == CifsNeedReconnect) &&
2876                     (le64_to_cpu(tcon->fsUnixInfo.Capability) &
2877                      CIFS_UNIX_TRANSPORT_ENCRYPTION_MANDATORY_CAP))
2878                         return -EACCES;
2879         } else
2880                 tcon->unix_ext = 0; /* server does not support them */
2881
2882         /* do not care if a following call succeed - informational */
2883         if (!tcon->pipe && server->ops->qfs_tcon) {
2884                 server->ops->qfs_tcon(*xid, tcon, cifs_sb);
2885                 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RO_CACHE) {
2886                         if (tcon->fsDevInfo.DeviceCharacteristics &
2887                             cpu_to_le32(FILE_READ_ONLY_DEVICE))
2888                                 cifs_dbg(VFS, "mounted to read only share\n");
2889                         else if ((cifs_sb->mnt_cifs_flags &
2890                                   CIFS_MOUNT_RW_CACHE) == 0)
2891                                 cifs_dbg(VFS, "read only mount of RW share\n");
2892                         /* no need to log a RW mount of a typical RW share */
2893                 }
2894         }
2895
2896         /*
2897          * Clamp the rsize/wsize mount arguments if they are too big for the server
2898          * and set the rsize/wsize to the negotiated values if not passed in by
2899          * the user on mount
2900          */
2901         if ((cifs_sb->ctx->wsize == 0) ||
2902             (cifs_sb->ctx->wsize > server->ops->negotiate_wsize(tcon, ctx)))
2903                 cifs_sb->ctx->wsize = server->ops->negotiate_wsize(tcon, ctx);
2904         if ((cifs_sb->ctx->rsize == 0) ||
2905             (cifs_sb->ctx->rsize > server->ops->negotiate_rsize(tcon, ctx)))
2906                 cifs_sb->ctx->rsize = server->ops->negotiate_rsize(tcon, ctx);
2907
2908         return 0;
2909 }
2910
2911 static int mount_setup_tlink(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
2912                              struct cifs_tcon *tcon)
2913 {
2914         struct tcon_link *tlink;
2915
2916         /* hang the tcon off of the superblock */
2917         tlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
2918         if (tlink == NULL)
2919                 return -ENOMEM;
2920
2921         tlink->tl_uid = ses->linux_uid;
2922         tlink->tl_tcon = tcon;
2923         tlink->tl_time = jiffies;
2924         set_bit(TCON_LINK_MASTER, &tlink->tl_flags);
2925         set_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
2926
2927         cifs_sb->master_tlink = tlink;
2928         spin_lock(&cifs_sb->tlink_tree_lock);
2929         tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
2930         spin_unlock(&cifs_sb->tlink_tree_lock);
2931
2932         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
2933                                 TLINK_IDLE_EXPIRE);
2934         return 0;
2935 }
2936
2937 #ifdef CONFIG_CIFS_DFS_UPCALL
2938 /*
2939  * cifs_build_path_to_root returns full path to root when we do not have an
2940  * existing connection (tcon)
2941  */
2942 static char *
2943 build_unc_path_to_root(const struct smb3_fs_context *ctx,
2944                        const struct cifs_sb_info *cifs_sb, bool useppath)
2945 {
2946         char *full_path, *pos;
2947         unsigned int pplen = useppath && ctx->prepath ?
2948                 strlen(ctx->prepath) + 1 : 0;
2949         unsigned int unc_len = strnlen(ctx->UNC, MAX_TREE_SIZE + 1);
2950
2951         if (unc_len > MAX_TREE_SIZE)
2952                 return ERR_PTR(-EINVAL);
2953
2954         full_path = kmalloc(unc_len + pplen + 1, GFP_KERNEL);
2955         if (full_path == NULL)
2956                 return ERR_PTR(-ENOMEM);
2957
2958         memcpy(full_path, ctx->UNC, unc_len);
2959         pos = full_path + unc_len;
2960
2961         if (pplen) {
2962                 *pos = CIFS_DIR_SEP(cifs_sb);
2963                 memcpy(pos + 1, ctx->prepath, pplen);
2964                 pos += pplen;
2965         }
2966
2967         *pos = '\0'; /* add trailing null */
2968         convert_delimiter(full_path, CIFS_DIR_SEP(cifs_sb));
2969         cifs_dbg(FYI, "%s: full_path=%s\n", __func__, full_path);
2970         return full_path;
2971 }
2972
2973 /**
2974  * expand_dfs_referral - Perform a dfs referral query and update the cifs_sb
2975  *
2976  * If a referral is found, cifs_sb->ctx->mount_options will be (re-)allocated
2977  * to a string containing updated options for the submount.  Otherwise it
2978  * will be left untouched.
2979  *
2980  * Returns the rc from get_dfs_path to the caller, which can be used to
2981  * determine whether there were referrals.
2982  */
2983 static int
2984 expand_dfs_referral(const unsigned int xid, struct cifs_ses *ses,
2985                     struct smb3_fs_context *ctx, struct cifs_sb_info *cifs_sb,
2986                     char *ref_path)
2987 {
2988         int rc;
2989         struct dfs_info3_param referral = {0};
2990         char *full_path = NULL, *mdata = NULL;
2991
2992         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
2993                 return -EREMOTE;
2994
2995         full_path = build_unc_path_to_root(ctx, cifs_sb, true);
2996         if (IS_ERR(full_path))
2997                 return PTR_ERR(full_path);
2998
2999         rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
3000                             ref_path, &referral, NULL);
3001         if (!rc) {
3002                 char *fake_devname = NULL;
3003
3004                 mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options,
3005                                                    full_path + 1, &referral,
3006                                                    &fake_devname);
3007                 free_dfs_info_param(&referral);
3008
3009                 if (IS_ERR(mdata)) {
3010                         rc = PTR_ERR(mdata);
3011                         mdata = NULL;
3012                 } else {
3013                         /*
3014                          * We can not clear out the whole structure since we
3015                          * no longer have an explicit function to parse
3016                          * a mount-string. Instead we need to clear out the
3017                          * individual fields that are no longer valid.
3018                          */
3019                         kfree(ctx->prepath);
3020                         ctx->prepath = NULL;
3021                         rc = cifs_setup_volume_info(ctx, mdata, fake_devname);
3022                 }
3023                 kfree(fake_devname);
3024                 kfree(cifs_sb->ctx->mount_options);
3025                 cifs_sb->ctx->mount_options = mdata;
3026         }
3027         kfree(full_path);
3028         return rc;
3029 }
3030
3031 static inline int get_next_dfs_tgt(const char *path,
3032                                    struct dfs_cache_tgt_list *tgt_list,
3033                                    struct dfs_cache_tgt_iterator **tgt_it)
3034 {
3035         if (!*tgt_it)
3036                 *tgt_it = dfs_cache_get_tgt_iterator(tgt_list);
3037         else
3038                 *tgt_it = dfs_cache_get_next_tgt(tgt_list, *tgt_it);
3039         return !*tgt_it ? -EHOSTDOWN : 0;
3040 }
3041
3042 static int update_vol_info(const struct dfs_cache_tgt_iterator *tgt_it,
3043                            struct smb3_fs_context *fake_ctx, struct smb3_fs_context *ctx)
3044 {
3045         const char *tgt = dfs_cache_get_tgt_name(tgt_it);
3046         int len = strlen(tgt) + 2;
3047         char *new_unc;
3048
3049         new_unc = kmalloc(len, GFP_KERNEL);
3050         if (!new_unc)
3051                 return -ENOMEM;
3052         scnprintf(new_unc, len, "\\%s", tgt);
3053
3054         kfree(ctx->UNC);
3055         ctx->UNC = new_unc;
3056
3057         if (fake_ctx->prepath) {
3058                 kfree(ctx->prepath);
3059                 ctx->prepath = fake_ctx->prepath;
3060                 fake_ctx->prepath = NULL;
3061         }
3062         memcpy(&ctx->dstaddr, &fake_ctx->dstaddr, sizeof(ctx->dstaddr));
3063
3064         return 0;
3065 }
3066
3067 static int do_dfs_failover(const char *path, const char *full_path, struct cifs_sb_info *cifs_sb,
3068                            struct smb3_fs_context *ctx, struct cifs_ses *root_ses,
3069                            unsigned int *xid, struct TCP_Server_Info **server,
3070                            struct cifs_ses **ses, struct cifs_tcon **tcon)
3071 {
3072         int rc;
3073         struct dfs_cache_tgt_list tgt_list = {0};
3074         struct dfs_cache_tgt_iterator *tgt_it = NULL;
3075         struct smb3_fs_context tmp_ctx = {NULL};
3076
3077         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS)
3078                 return -EOPNOTSUPP;
3079
3080         cifs_dbg(FYI, "%s: path=%s full_path=%s\n", __func__, path, full_path);
3081
3082         rc = dfs_cache_noreq_find(path, NULL, &tgt_list);
3083         if (rc)
3084                 return rc;
3085         /*
3086          * We use a 'tmp_ctx' here because we need pass it down to the mount_{get,put} functions to
3087          * test connection against new DFS targets.
3088          */
3089         rc = smb3_fs_context_dup(&tmp_ctx, ctx);
3090         if (rc)
3091                 goto out;
3092
3093         for (;;) {
3094                 struct dfs_info3_param ref = {0};
3095                 char *fake_devname = NULL, *mdata = NULL;
3096
3097                 /* Get next DFS target server - if any */
3098                 rc = get_next_dfs_tgt(path, &tgt_list, &tgt_it);
3099                 if (rc)
3100                         break;
3101
3102                 rc = dfs_cache_get_tgt_referral(path, tgt_it, &ref);
3103                 if (rc)
3104                         break;
3105
3106                 cifs_dbg(FYI, "%s: old ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3107                          tmp_ctx.prepath);
3108
3109                 mdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options, full_path + 1, &ref,
3110                                                    &fake_devname);
3111                 free_dfs_info_param(&ref);
3112
3113                 if (IS_ERR(mdata)) {
3114                         rc = PTR_ERR(mdata);
3115                         mdata = NULL;
3116                 } else
3117                         rc = cifs_setup_volume_info(&tmp_ctx, mdata, fake_devname);
3118
3119                 kfree(mdata);
3120                 kfree(fake_devname);
3121
3122                 if (rc)
3123                         break;
3124
3125                 cifs_dbg(FYI, "%s: new ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3126                          tmp_ctx.prepath);
3127
3128                 mount_put_conns(cifs_sb, *xid, *server, *ses, *tcon);
3129                 rc = mount_get_conns(&tmp_ctx, cifs_sb, xid, server, ses, tcon);
3130                 if (!rc || (*server && *ses)) {
3131                         /*
3132                          * We were able to connect to new target server. Update current context with
3133                          * new target server.
3134                          */
3135                         rc = update_vol_info(tgt_it, &tmp_ctx, ctx);
3136                         break;
3137                 }
3138         }
3139         if (!rc) {
3140                 cifs_dbg(FYI, "%s: final ctx: UNC=%s prepath=%s\n", __func__, tmp_ctx.UNC,
3141                          tmp_ctx.prepath);
3142                 /*
3143                  * Update DFS target hint in DFS referral cache with the target server we
3144                  * successfully reconnected to.
3145                  */
3146                 rc = dfs_cache_update_tgthint(*xid, root_ses ? root_ses : *ses, cifs_sb->local_nls,
3147                                               cifs_remap(cifs_sb), path, tgt_it);
3148         }
3149
3150 out:
3151         smb3_cleanup_fs_context_contents(&tmp_ctx);
3152         dfs_cache_free_tgts(&tgt_list);
3153         return rc;
3154 }
3155 #endif
3156
3157 /* TODO: all callers to this are broken. We are not parsing mount_options here
3158  * we should pass a clone of the original context?
3159  */
3160 int
3161 cifs_setup_volume_info(struct smb3_fs_context *ctx, const char *mntopts, const char *devname)
3162 {
3163         int rc = 0;
3164
3165         smb3_parse_devname(devname, ctx);
3166
3167         if (mntopts) {
3168                 char *ip;
3169
3170                 cifs_dbg(FYI, "%s: mntopts=%s\n", __func__, mntopts);
3171                 rc = smb3_parse_opt(mntopts, "ip", &ip);
3172                 if (!rc && !cifs_convert_address((struct sockaddr *)&ctx->dstaddr, ip,
3173                                                  strlen(ip))) {
3174                         cifs_dbg(VFS, "%s: failed to convert ip address\n", __func__);
3175                         return -EINVAL;
3176                 }
3177         }
3178
3179         if (ctx->nullauth) {
3180                 cifs_dbg(FYI, "Anonymous login\n");
3181                 kfree(ctx->username);
3182                 ctx->username = NULL;
3183         } else if (ctx->username) {
3184                 /* BB fixme parse for domain name here */
3185                 cifs_dbg(FYI, "Username: %s\n", ctx->username);
3186         } else {
3187                 cifs_dbg(VFS, "No username specified\n");
3188         /* In userspace mount helper we can get user name from alternate
3189            locations such as env variables and files on disk */
3190                 return -EINVAL;
3191         }
3192
3193         return rc;
3194 }
3195
3196 static int
3197 cifs_are_all_path_components_accessible(struct TCP_Server_Info *server,
3198                                         unsigned int xid,
3199                                         struct cifs_tcon *tcon,
3200                                         struct cifs_sb_info *cifs_sb,
3201                                         char *full_path,
3202                                         int added_treename)
3203 {
3204         int rc;
3205         char *s;
3206         char sep, tmp;
3207         int skip = added_treename ? 1 : 0;
3208
3209         sep = CIFS_DIR_SEP(cifs_sb);
3210         s = full_path;
3211
3212         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb, "");
3213         while (rc == 0) {
3214                 /* skip separators */
3215                 while (*s == sep)
3216                         s++;
3217                 if (!*s)
3218                         break;
3219                 /* next separator */
3220                 while (*s && *s != sep)
3221                         s++;
3222                 /*
3223                  * if the treename is added, we then have to skip the first
3224                  * part within the separators
3225                  */
3226                 if (skip) {
3227                         skip = 0;
3228                         continue;
3229                 }
3230                 /*
3231                  * temporarily null-terminate the path at the end of
3232                  * the current component
3233                  */
3234                 tmp = *s;
3235                 *s = 0;
3236                 rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3237                                                      full_path);
3238                 *s = tmp;
3239         }
3240         return rc;
3241 }
3242
3243 /*
3244  * Check if path is remote (e.g. a DFS share). Return -EREMOTE if it is,
3245  * otherwise 0.
3246  */
3247 static int is_path_remote(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx,
3248                           const unsigned int xid,
3249                           struct TCP_Server_Info *server,
3250                           struct cifs_tcon *tcon)
3251 {
3252         int rc;
3253         char *full_path;
3254
3255         if (!server->ops->is_path_accessible)
3256                 return -EOPNOTSUPP;
3257
3258         /*
3259          * cifs_build_path_to_root works only when we have a valid tcon
3260          */
3261         full_path = cifs_build_path_to_root(ctx, cifs_sb, tcon,
3262                                             tcon->Flags & SMB_SHARE_IS_IN_DFS);
3263         if (full_path == NULL)
3264                 return -ENOMEM;
3265
3266         cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
3267
3268         rc = server->ops->is_path_accessible(xid, tcon, cifs_sb,
3269                                              full_path);
3270         if (rc != 0 && rc != -EREMOTE) {
3271                 kfree(full_path);
3272                 return rc;
3273         }
3274
3275         if (rc != -EREMOTE) {
3276                 rc = cifs_are_all_path_components_accessible(server, xid, tcon,
3277                         cifs_sb, full_path, tcon->Flags & SMB_SHARE_IS_IN_DFS);
3278                 if (rc != 0) {
3279                         cifs_server_dbg(VFS, "cannot query dirs between root and final path, enabling CIFS_MOUNT_USE_PREFIX_PATH\n");
3280                         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3281                         rc = 0;
3282                 }
3283         }
3284
3285         kfree(full_path);
3286         return rc;
3287 }
3288
3289 #ifdef CONFIG_CIFS_DFS_UPCALL
3290 static void set_root_ses(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
3291                          struct cifs_ses **root_ses)
3292 {
3293         if (ses) {
3294                 spin_lock(&cifs_tcp_ses_lock);
3295                 ses->ses_count++;
3296                 if (ses->tcon_ipc)
3297                         ses->tcon_ipc->remap = cifs_remap(cifs_sb);
3298                 spin_unlock(&cifs_tcp_ses_lock);
3299         }
3300         *root_ses = ses;
3301 }
3302
3303 static void put_root_ses(struct cifs_ses *ses)
3304 {
3305         if (ses)
3306                 cifs_put_smb_ses(ses);
3307 }
3308
3309 /* Set up next dfs prefix path in @dfs_path */
3310 static int next_dfs_prepath(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx,
3311                             const unsigned int xid, struct TCP_Server_Info *server,
3312                             struct cifs_tcon *tcon, char **dfs_path)
3313 {
3314         char *path, *npath;
3315         int added_treename = is_tcon_dfs(tcon);
3316         int rc;
3317
3318         path = cifs_build_path_to_root(ctx, cifs_sb, tcon, added_treename);
3319         if (!path)
3320                 return -ENOMEM;
3321
3322         rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3323         if (rc == -EREMOTE) {
3324                 struct smb3_fs_context v = {NULL};
3325                 /* if @path contains a tree name, skip it in the prefix path */
3326                 if (added_treename) {
3327                         rc = smb3_parse_devname(path, &v);
3328                         if (rc)
3329                                 goto out;
3330                         npath = build_unc_path_to_root(&v, cifs_sb, true);
3331                         smb3_cleanup_fs_context_contents(&v);
3332                 } else {
3333                         v.UNC = ctx->UNC;
3334                         v.prepath = path + 1;
3335                         npath = build_unc_path_to_root(&v, cifs_sb, true);
3336                 }
3337
3338                 if (IS_ERR(npath)) {
3339                         rc = PTR_ERR(npath);
3340                         goto out;
3341                 }
3342
3343                 kfree(*dfs_path);
3344                 *dfs_path = npath;
3345                 rc = -EREMOTE;
3346         }
3347
3348 out:
3349         kfree(path);
3350         return rc;
3351 }
3352
3353 /* Check if resolved targets can handle any DFS referrals */
3354 static int is_referral_server(const char *ref_path, struct cifs_tcon *tcon, bool *ref_server)
3355 {
3356         int rc;
3357         struct dfs_info3_param ref = {0};
3358
3359         if (is_tcon_dfs(tcon)) {
3360                 *ref_server = true;
3361         } else {
3362                 cifs_dbg(FYI, "%s: ref_path=%s\n", __func__, ref_path);
3363
3364                 rc = dfs_cache_noreq_find(ref_path, &ref, NULL);
3365                 if (rc) {
3366                         cifs_dbg(VFS, "%s: dfs_cache_noreq_find: failed (rc=%d)\n", __func__, rc);
3367                         return rc;
3368                 }
3369                 cifs_dbg(FYI, "%s: ref.flags=0x%x\n", __func__, ref.flags);
3370                 /*
3371                  * Check if all targets are capable of handling DFS referrals as per
3372                  * MS-DFSC 2.2.4 RESP_GET_DFS_REFERRAL.
3373                  */
3374                 *ref_server = !!(ref.flags & DFSREF_REFERRAL_SERVER);
3375                 free_dfs_info_param(&ref);
3376         }
3377         return 0;
3378 }
3379
3380 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3381 {
3382         int rc = 0;
3383         unsigned int xid;
3384         struct TCP_Server_Info *server = NULL;
3385         struct cifs_ses *ses = NULL, *root_ses = NULL;
3386         struct cifs_tcon *tcon = NULL;
3387         int count = 0;
3388         char *ref_path = NULL, *full_path = NULL;
3389         char *oldmnt = NULL;
3390         char *mntdata = NULL;
3391         bool ref_server = false;
3392
3393         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3394         /*
3395          * If called with 'nodfs' mount option, then skip DFS resolving.  Otherwise unconditionally
3396          * try to get an DFS referral (even cached) to determine whether it is an DFS mount.
3397          *
3398          * Skip prefix path to provide support for DFS referrals from w2k8 servers which don't seem
3399          * to respond with PATH_NOT_COVERED to requests that include the prefix.
3400          */
3401         if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) ||
3402             dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb), ctx->UNC + 1, NULL,
3403                            NULL)) {
3404                 if (rc)
3405                         goto error;
3406                 /* Check if it is fully accessible and then mount it */
3407                 rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3408                 if (!rc)
3409                         goto out;
3410                 if (rc != -EREMOTE)
3411                         goto error;
3412         }
3413         /* Save mount options */
3414         mntdata = kstrndup(cifs_sb->ctx->mount_options,
3415                            strlen(cifs_sb->ctx->mount_options), GFP_KERNEL);
3416         if (!mntdata) {
3417                 rc = -ENOMEM;
3418                 goto error;
3419         }
3420         /* Get path of DFS root */
3421         ref_path = build_unc_path_to_root(ctx, cifs_sb, false);
3422         if (IS_ERR(ref_path)) {
3423                 rc = PTR_ERR(ref_path);
3424                 ref_path = NULL;
3425                 goto error;
3426         }
3427
3428         set_root_ses(cifs_sb, ses, &root_ses);
3429         do {
3430                 /* Save full path of last DFS path we used to resolve final target server */
3431                 kfree(full_path);
3432                 full_path = build_unc_path_to_root(ctx, cifs_sb, !!count);
3433                 if (IS_ERR(full_path)) {
3434                         rc = PTR_ERR(full_path);
3435                         full_path = NULL;
3436                         break;
3437                 }
3438                 /* Chase referral */
3439                 oldmnt = cifs_sb->ctx->mount_options;
3440                 rc = expand_dfs_referral(xid, root_ses, ctx, cifs_sb, ref_path + 1);
3441                 if (rc)
3442                         break;
3443                 /* Connect to new DFS target only if we were redirected */
3444                 if (oldmnt != cifs_sb->ctx->mount_options) {
3445                         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3446                         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3447                 }
3448                 if (rc && !server && !ses) {
3449                         /* Failed to connect. Try to connect to other targets in the referral. */
3450                         rc = do_dfs_failover(ref_path + 1, full_path, cifs_sb, ctx, root_ses, &xid,
3451                                              &server, &ses, &tcon);
3452                 }
3453                 if (rc == -EACCES || rc == -EOPNOTSUPP || !server || !ses)
3454                         break;
3455                 if (!tcon)
3456                         continue;
3457
3458                 /* Make sure that requests go through new root servers */
3459                 rc = is_referral_server(ref_path + 1, tcon, &ref_server);
3460                 if (rc)
3461                         break;
3462                 if (ref_server) {
3463                         put_root_ses(root_ses);
3464                         set_root_ses(cifs_sb, ses, &root_ses);
3465                 }
3466
3467                 /* Get next dfs path and then continue chasing them if -EREMOTE */
3468                 rc = next_dfs_prepath(cifs_sb, ctx, xid, server, tcon, &ref_path);
3469                 /* Prevent recursion on broken link referrals */
3470                 if (rc == -EREMOTE && ++count > MAX_NESTED_LINKS)
3471                         rc = -ELOOP;
3472         } while (rc == -EREMOTE);
3473
3474         if (rc)
3475                 goto error;
3476         put_root_ses(root_ses);
3477         root_ses = NULL;
3478         kfree(ref_path);
3479         ref_path = NULL;
3480         /*
3481          * Store DFS full path in both superblock and tree connect structures.
3482          *
3483          * For DFS root mounts, the prefix path (cifs_sb->prepath) is preserved during reconnect so
3484          * only the root path is set in cifs_sb->origin_fullpath and tcon->dfs_path. And for DFS
3485          * links, the prefix path is included in both and may be changed during reconnect.  See
3486          * cifs_tree_connect().
3487          */
3488         cifs_sb->origin_fullpath = kstrndup(full_path, strlen(full_path), GFP_KERNEL);
3489         if (!cifs_sb->origin_fullpath) {
3490                 rc = -ENOMEM;
3491                 goto error;
3492         }
3493         spin_lock(&cifs_tcp_ses_lock);
3494         tcon->dfs_path = full_path;
3495         full_path = NULL;
3496         tcon->remap = cifs_remap(cifs_sb);
3497         spin_unlock(&cifs_tcp_ses_lock);
3498
3499         /* Add original context for DFS cache to be used when refreshing referrals */
3500         rc = dfs_cache_add_vol(mntdata, ctx, cifs_sb->origin_fullpath);
3501         if (rc)
3502                 goto error;
3503         /*
3504          * After reconnecting to a different server, unique ids won't
3505          * match anymore, so we disable serverino. This prevents
3506          * dentry revalidation to think the dentry are stale (ESTALE).
3507          */
3508         cifs_autodisable_serverino(cifs_sb);
3509         /*
3510          * Force the use of prefix path to support failover on DFS paths that
3511          * resolve to targets that have different prefix paths.
3512          */
3513         cifs_sb->mnt_cifs_flags |= CIFS_MOUNT_USE_PREFIX_PATH;
3514         kfree(cifs_sb->prepath);
3515         cifs_sb->prepath = ctx->prepath;
3516         ctx->prepath = NULL;
3517
3518 out:
3519         free_xid(xid);
3520         cifs_try_adding_channels(cifs_sb, ses);
3521         return mount_setup_tlink(cifs_sb, ses, tcon);
3522
3523 error:
3524         kfree(ref_path);
3525         kfree(full_path);
3526         kfree(mntdata);
3527         kfree(cifs_sb->origin_fullpath);
3528         put_root_ses(root_ses);
3529         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3530         return rc;
3531 }
3532 #else
3533 int cifs_mount(struct cifs_sb_info *cifs_sb, struct smb3_fs_context *ctx)
3534 {
3535         int rc = 0;
3536         unsigned int xid;
3537         struct cifs_ses *ses;
3538         struct cifs_tcon *tcon;
3539         struct TCP_Server_Info *server;
3540
3541         rc = mount_get_conns(ctx, cifs_sb, &xid, &server, &ses, &tcon);
3542         if (rc)
3543                 goto error;
3544
3545         if (tcon) {
3546                 rc = is_path_remote(cifs_sb, ctx, xid, server, tcon);
3547                 if (rc == -EREMOTE)
3548                         rc = -EOPNOTSUPP;
3549                 if (rc)
3550                         goto error;
3551         }
3552
3553         free_xid(xid);
3554
3555         return mount_setup_tlink(cifs_sb, ses, tcon);
3556
3557 error:
3558         mount_put_conns(cifs_sb, xid, server, ses, tcon);
3559         return rc;
3560 }
3561 #endif
3562
3563 /*
3564  * Issue a TREE_CONNECT request.
3565  */
3566 int
3567 CIFSTCon(const unsigned int xid, struct cifs_ses *ses,
3568          const char *tree, struct cifs_tcon *tcon,
3569          const struct nls_table *nls_codepage)
3570 {
3571         struct smb_hdr *smb_buffer;
3572         struct smb_hdr *smb_buffer_response;
3573         TCONX_REQ *pSMB;
3574         TCONX_RSP *pSMBr;
3575         unsigned char *bcc_ptr;
3576         int rc = 0;
3577         int length;
3578         __u16 bytes_left, count;
3579
3580         if (ses == NULL)
3581                 return -EIO;
3582
3583         smb_buffer = cifs_buf_get();
3584         if (smb_buffer == NULL)
3585                 return -ENOMEM;
3586
3587         smb_buffer_response = smb_buffer;
3588
3589         header_assemble(smb_buffer, SMB_COM_TREE_CONNECT_ANDX,
3590                         NULL /*no tid */ , 4 /*wct */ );
3591
3592         smb_buffer->Mid = get_next_mid(ses->server);
3593         smb_buffer->Uid = ses->Suid;
3594         pSMB = (TCONX_REQ *) smb_buffer;
3595         pSMBr = (TCONX_RSP *) smb_buffer_response;
3596
3597         pSMB->AndXCommand = 0xFF;
3598         pSMB->Flags = cpu_to_le16(TCON_EXTENDED_SECINFO);
3599         bcc_ptr = &pSMB->Password[0];
3600         if (tcon->pipe || (ses->server->sec_mode & SECMODE_USER)) {
3601                 pSMB->PasswordLength = cpu_to_le16(1);  /* minimum */
3602                 *bcc_ptr = 0; /* password is null byte */
3603                 bcc_ptr++;              /* skip password */
3604                 /* already aligned so no need to do it below */
3605         } else {
3606                 pSMB->PasswordLength = cpu_to_le16(CIFS_AUTH_RESP_SIZE);
3607                 /* BB FIXME add code to fail this if NTLMv2 or Kerberos
3608                    specified as required (when that support is added to
3609                    the vfs in the future) as only NTLM or the much
3610                    weaker LANMAN (which we do not send by default) is accepted
3611                    by Samba (not sure whether other servers allow
3612                    NTLMv2 password here) */
3613 #ifdef CONFIG_CIFS_WEAK_PW_HASH
3614                 if ((global_secflags & CIFSSEC_MAY_LANMAN) &&
3615                     (ses->sectype == LANMAN))
3616                         calc_lanman_hash(tcon->password, ses->server->cryptkey,
3617                                          ses->server->sec_mode &
3618                                             SECMODE_PW_ENCRYPT ? true : false,
3619                                          bcc_ptr);
3620                 else
3621 #endif /* CIFS_WEAK_PW_HASH */
3622                 rc = SMBNTencrypt(tcon->password, ses->server->cryptkey,
3623                                         bcc_ptr, nls_codepage);
3624                 if (rc) {
3625                         cifs_dbg(FYI, "%s Can't generate NTLM rsp. Error: %d\n",
3626                                  __func__, rc);
3627                         cifs_buf_release(smb_buffer);
3628                         return rc;
3629                 }
3630
3631                 bcc_ptr += CIFS_AUTH_RESP_SIZE;
3632                 if (ses->capabilities & CAP_UNICODE) {
3633                         /* must align unicode strings */
3634                         *bcc_ptr = 0; /* null byte password */
3635                         bcc_ptr++;
3636                 }
3637         }
3638
3639         if (ses->server->sign)
3640                 smb_buffer->Flags2 |= SMBFLG2_SECURITY_SIGNATURE;
3641
3642         if (ses->capabilities & CAP_STATUS32) {
3643                 smb_buffer->Flags2 |= SMBFLG2_ERR_STATUS;
3644         }
3645         if (ses->capabilities & CAP_DFS) {
3646                 smb_buffer->Flags2 |= SMBFLG2_DFS;
3647         }
3648         if (ses->capabilities & CAP_UNICODE) {
3649                 smb_buffer->Flags2 |= SMBFLG2_UNICODE;
3650                 length =
3651                     cifs_strtoUTF16((__le16 *) bcc_ptr, tree,
3652                         6 /* max utf8 char length in bytes */ *
3653                         (/* server len*/ + 256 /* share len */), nls_codepage);
3654                 bcc_ptr += 2 * length;  /* convert num 16 bit words to bytes */
3655                 bcc_ptr += 2;   /* skip trailing null */
3656         } else {                /* ASCII */
3657                 strcpy(bcc_ptr, tree);
3658                 bcc_ptr += strlen(tree) + 1;
3659         }
3660         strcpy(bcc_ptr, "?????");
3661         bcc_ptr += strlen("?????");
3662         bcc_ptr += 1;
3663         count = bcc_ptr - &pSMB->Password[0];
3664         be32_add_cpu(&pSMB->hdr.smb_buf_length, count);
3665         pSMB->ByteCount = cpu_to_le16(count);
3666
3667         rc = SendReceive(xid, ses, smb_buffer, smb_buffer_response, &length,
3668                          0);
3669
3670         /* above now done in SendReceive */
3671         if (rc == 0) {
3672                 bool is_unicode;
3673
3674                 tcon->tidStatus = CifsGood;
3675                 tcon->need_reconnect = false;
3676                 tcon->tid = smb_buffer_response->Tid;
3677                 bcc_ptr = pByteArea(smb_buffer_response);
3678                 bytes_left = get_bcc(smb_buffer_response);
3679                 length = strnlen(bcc_ptr, bytes_left - 2);
3680                 if (smb_buffer->Flags2 & SMBFLG2_UNICODE)
3681                         is_unicode = true;
3682                 else
3683                         is_unicode = false;
3684
3685
3686                 /* skip service field (NB: this field is always ASCII) */
3687                 if (length == 3) {
3688                         if ((bcc_ptr[0] == 'I') && (bcc_ptr[1] == 'P') &&
3689                             (bcc_ptr[2] == 'C')) {
3690                                 cifs_dbg(FYI, "IPC connection\n");
3691                                 tcon->ipc = true;
3692                                 tcon->pipe = true;
3693                         }
3694                 } else if (length == 2) {
3695                         if ((bcc_ptr[0] == 'A') && (bcc_ptr[1] == ':')) {
3696                                 /* the most common case */
3697                                 cifs_dbg(FYI, "disk share connection\n");
3698                         }
3699                 }
3700                 bcc_ptr += length + 1;
3701                 bytes_left -= (length + 1);
3702                 strlcpy(tcon->treeName, tree, sizeof(tcon->treeName));
3703
3704                 /* mostly informational -- no need to fail on error here */
3705                 kfree(tcon->nativeFileSystem);
3706                 tcon->nativeFileSystem = cifs_strndup_from_utf16(bcc_ptr,
3707                                                       bytes_left, is_unicode,
3708                                                       nls_codepage);
3709
3710                 cifs_dbg(FYI, "nativeFileSystem=%s\n", tcon->nativeFileSystem);
3711
3712                 if ((smb_buffer_response->WordCount == 3) ||
3713                          (smb_buffer_response->WordCount == 7))
3714                         /* field is in same location */
3715                         tcon->Flags = le16_to_cpu(pSMBr->OptionalSupport);
3716                 else
3717                         tcon->Flags = 0;
3718                 cifs_dbg(FYI, "Tcon flags: 0x%x\n", tcon->Flags);
3719         }
3720
3721         cifs_buf_release(smb_buffer);
3722         return rc;
3723 }
3724
3725 static void delayed_free(struct rcu_head *p)
3726 {
3727         struct cifs_sb_info *cifs_sb = container_of(p, struct cifs_sb_info, rcu);
3728
3729         unload_nls(cifs_sb->local_nls);
3730         smb3_cleanup_fs_context(cifs_sb->ctx);
3731         kfree(cifs_sb);
3732 }
3733
3734 void
3735 cifs_umount(struct cifs_sb_info *cifs_sb)
3736 {
3737         struct rb_root *root = &cifs_sb->tlink_tree;
3738         struct rb_node *node;
3739         struct tcon_link *tlink;
3740
3741         cancel_delayed_work_sync(&cifs_sb->prune_tlinks);
3742
3743         spin_lock(&cifs_sb->tlink_tree_lock);
3744         while ((node = rb_first(root))) {
3745                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3746                 cifs_get_tlink(tlink);
3747                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
3748                 rb_erase(node, root);
3749
3750                 spin_unlock(&cifs_sb->tlink_tree_lock);
3751                 cifs_put_tlink(tlink);
3752                 spin_lock(&cifs_sb->tlink_tree_lock);
3753         }
3754         spin_unlock(&cifs_sb->tlink_tree_lock);
3755
3756         kfree(cifs_sb->prepath);
3757 #ifdef CONFIG_CIFS_DFS_UPCALL
3758         dfs_cache_del_vol(cifs_sb->origin_fullpath);
3759         kfree(cifs_sb->origin_fullpath);
3760 #endif
3761         call_rcu(&cifs_sb->rcu, delayed_free);
3762 }
3763
3764 int
3765 cifs_negotiate_protocol(const unsigned int xid, struct cifs_ses *ses)
3766 {
3767         int rc = 0;
3768         struct TCP_Server_Info *server = cifs_ses_server(ses);
3769
3770         if (!server->ops->need_neg || !server->ops->negotiate)
3771                 return -ENOSYS;
3772
3773         /* only send once per connect */
3774         if (!server->ops->need_neg(server))
3775                 return 0;
3776
3777         rc = server->ops->negotiate(xid, ses);
3778         if (rc == 0) {
3779                 spin_lock(&GlobalMid_Lock);
3780                 if (server->tcpStatus == CifsNeedNegotiate)
3781                         server->tcpStatus = CifsGood;
3782                 else
3783                         rc = -EHOSTDOWN;
3784                 spin_unlock(&GlobalMid_Lock);
3785         }
3786
3787         return rc;
3788 }
3789
3790 int
3791 cifs_setup_session(const unsigned int xid, struct cifs_ses *ses,
3792                    struct nls_table *nls_info)
3793 {
3794         int rc = -ENOSYS;
3795         struct TCP_Server_Info *server = cifs_ses_server(ses);
3796
3797         if (!ses->binding) {
3798                 ses->capabilities = server->capabilities;
3799                 if (!linuxExtEnabled)
3800                         ses->capabilities &= (~server->vals->cap_unix);
3801
3802                 if (ses->auth_key.response) {
3803                         cifs_dbg(FYI, "Free previous auth_key.response = %p\n",
3804                                  ses->auth_key.response);
3805                         kfree(ses->auth_key.response);
3806                         ses->auth_key.response = NULL;
3807                         ses->auth_key.len = 0;
3808                 }
3809         }
3810
3811         cifs_dbg(FYI, "Security Mode: 0x%x Capabilities: 0x%x TimeAdjust: %d\n",
3812                  server->sec_mode, server->capabilities, server->timeAdj);
3813
3814         if (server->ops->sess_setup)
3815                 rc = server->ops->sess_setup(xid, ses, nls_info);
3816
3817         if (rc)
3818                 cifs_server_dbg(VFS, "Send error in SessSetup = %d\n", rc);
3819
3820         return rc;
3821 }
3822
3823 static int
3824 cifs_set_vol_auth(struct smb3_fs_context *ctx, struct cifs_ses *ses)
3825 {
3826         ctx->sectype = ses->sectype;
3827
3828         /* krb5 is special, since we don't need username or pw */
3829         if (ctx->sectype == Kerberos)
3830                 return 0;
3831
3832         return cifs_set_cifscreds(ctx, ses);
3833 }
3834
3835 static struct cifs_tcon *
3836 cifs_construct_tcon(struct cifs_sb_info *cifs_sb, kuid_t fsuid)
3837 {
3838         int rc;
3839         struct cifs_tcon *master_tcon = cifs_sb_master_tcon(cifs_sb);
3840         struct cifs_ses *ses;
3841         struct cifs_tcon *tcon = NULL;
3842         struct smb3_fs_context *ctx;
3843
3844         ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
3845         if (ctx == NULL)
3846                 return ERR_PTR(-ENOMEM);
3847
3848         ctx->local_nls = cifs_sb->local_nls;
3849         ctx->linux_uid = fsuid;
3850         ctx->cred_uid = fsuid;
3851         ctx->UNC = master_tcon->treeName;
3852         ctx->retry = master_tcon->retry;
3853         ctx->nocase = master_tcon->nocase;
3854         ctx->nohandlecache = master_tcon->nohandlecache;
3855         ctx->local_lease = master_tcon->local_lease;
3856         ctx->no_lease = master_tcon->no_lease;
3857         ctx->resilient = master_tcon->use_resilient;
3858         ctx->persistent = master_tcon->use_persistent;
3859         ctx->handle_timeout = master_tcon->handle_timeout;
3860         ctx->no_linux_ext = !master_tcon->unix_ext;
3861         ctx->linux_ext = master_tcon->posix_extensions;
3862         ctx->sectype = master_tcon->ses->sectype;
3863         ctx->sign = master_tcon->ses->sign;
3864         ctx->seal = master_tcon->seal;
3865 #ifdef CONFIG_CIFS_SWN_UPCALL
3866         ctx->witness = master_tcon->use_witness;
3867 #endif
3868
3869         rc = cifs_set_vol_auth(ctx, master_tcon->ses);
3870         if (rc) {
3871                 tcon = ERR_PTR(rc);
3872                 goto out;
3873         }
3874
3875         /* get a reference for the same TCP session */
3876         spin_lock(&cifs_tcp_ses_lock);
3877         ++master_tcon->ses->server->srv_count;
3878         spin_unlock(&cifs_tcp_ses_lock);
3879
3880         ses = cifs_get_smb_ses(master_tcon->ses->server, ctx);
3881         if (IS_ERR(ses)) {
3882                 tcon = (struct cifs_tcon *)ses;
3883                 cifs_put_tcp_session(master_tcon->ses->server, 0);
3884                 goto out;
3885         }
3886
3887         tcon = cifs_get_tcon(ses, ctx);
3888         if (IS_ERR(tcon)) {
3889                 cifs_put_smb_ses(ses);
3890                 goto out;
3891         }
3892
3893         if (cap_unix(ses))
3894                 reset_cifs_unix_caps(0, tcon, NULL, ctx);
3895
3896 out:
3897         kfree(ctx->username);
3898         kfree_sensitive(ctx->password);
3899         kfree(ctx);
3900
3901         return tcon;
3902 }
3903
3904 struct cifs_tcon *
3905 cifs_sb_master_tcon(struct cifs_sb_info *cifs_sb)
3906 {
3907         return tlink_tcon(cifs_sb_master_tlink(cifs_sb));
3908 }
3909
3910 /* find and return a tlink with given uid */
3911 static struct tcon_link *
3912 tlink_rb_search(struct rb_root *root, kuid_t uid)
3913 {
3914         struct rb_node *node = root->rb_node;
3915         struct tcon_link *tlink;
3916
3917         while (node) {
3918                 tlink = rb_entry(node, struct tcon_link, tl_rbnode);
3919
3920                 if (uid_gt(tlink->tl_uid, uid))
3921                         node = node->rb_left;
3922                 else if (uid_lt(tlink->tl_uid, uid))
3923                         node = node->rb_right;
3924                 else
3925                         return tlink;
3926         }
3927         return NULL;
3928 }
3929
3930 /* insert a tcon_link into the tree */
3931 static void
3932 tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink)
3933 {
3934         struct rb_node **new = &(root->rb_node), *parent = NULL;
3935         struct tcon_link *tlink;
3936
3937         while (*new) {
3938                 tlink = rb_entry(*new, struct tcon_link, tl_rbnode);
3939                 parent = *new;
3940
3941                 if (uid_gt(tlink->tl_uid, new_tlink->tl_uid))
3942                         new = &((*new)->rb_left);
3943                 else
3944                         new = &((*new)->rb_right);
3945         }
3946
3947         rb_link_node(&new_tlink->tl_rbnode, parent, new);
3948         rb_insert_color(&new_tlink->tl_rbnode, root);
3949 }
3950
3951 /*
3952  * Find or construct an appropriate tcon given a cifs_sb and the fsuid of the
3953  * current task.
3954  *
3955  * If the superblock doesn't refer to a multiuser mount, then just return
3956  * the master tcon for the mount.
3957  *
3958  * First, search the rbtree for an existing tcon for this fsuid. If one
3959  * exists, then check to see if it's pending construction. If it is then wait
3960  * for construction to complete. Once it's no longer pending, check to see if
3961  * it failed and either return an error or retry construction, depending on
3962  * the timeout.
3963  *
3964  * If one doesn't exist then insert a new tcon_link struct into the tree and
3965  * try to construct a new one.
3966  */
3967 struct tcon_link *
3968 cifs_sb_tlink(struct cifs_sb_info *cifs_sb)
3969 {
3970         int ret;
3971         kuid_t fsuid = current_fsuid();
3972         struct tcon_link *tlink, *newtlink;
3973
3974         if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MULTIUSER))
3975                 return cifs_get_tlink(cifs_sb_master_tlink(cifs_sb));
3976
3977         spin_lock(&cifs_sb->tlink_tree_lock);
3978         tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3979         if (tlink)
3980                 cifs_get_tlink(tlink);
3981         spin_unlock(&cifs_sb->tlink_tree_lock);
3982
3983         if (tlink == NULL) {
3984                 newtlink = kzalloc(sizeof(*tlink), GFP_KERNEL);
3985                 if (newtlink == NULL)
3986                         return ERR_PTR(-ENOMEM);
3987                 newtlink->tl_uid = fsuid;
3988                 newtlink->tl_tcon = ERR_PTR(-EACCES);
3989                 set_bit(TCON_LINK_PENDING, &newtlink->tl_flags);
3990                 set_bit(TCON_LINK_IN_TREE, &newtlink->tl_flags);
3991                 cifs_get_tlink(newtlink);
3992
3993                 spin_lock(&cifs_sb->tlink_tree_lock);
3994                 /* was one inserted after previous search? */
3995                 tlink = tlink_rb_search(&cifs_sb->tlink_tree, fsuid);
3996                 if (tlink) {
3997                         cifs_get_tlink(tlink);
3998                         spin_unlock(&cifs_sb->tlink_tree_lock);
3999                         kfree(newtlink);
4000                         goto wait_for_construction;
4001                 }
4002                 tlink = newtlink;
4003                 tlink_rb_insert(&cifs_sb->tlink_tree, tlink);
4004                 spin_unlock(&cifs_sb->tlink_tree_lock);
4005         } else {
4006 wait_for_construction:
4007                 ret = wait_on_bit(&tlink->tl_flags, TCON_LINK_PENDING,
4008                                   TASK_INTERRUPTIBLE);
4009                 if (ret) {
4010                         cifs_put_tlink(tlink);
4011                         return ERR_PTR(-ERESTARTSYS);
4012                 }
4013
4014                 /* if it's good, return it */
4015                 if (!IS_ERR(tlink->tl_tcon))
4016                         return tlink;
4017
4018                 /* return error if we tried this already recently */
4019                 if (time_before(jiffies, tlink->tl_time + TLINK_ERROR_EXPIRE)) {
4020                         cifs_put_tlink(tlink);
4021                         return ERR_PTR(-EACCES);
4022                 }
4023
4024                 if (test_and_set_bit(TCON_LINK_PENDING, &tlink->tl_flags))
4025                         goto wait_for_construction;
4026         }
4027
4028         tlink->tl_tcon = cifs_construct_tcon(cifs_sb, fsuid);
4029         clear_bit(TCON_LINK_PENDING, &tlink->tl_flags);
4030         wake_up_bit(&tlink->tl_flags, TCON_LINK_PENDING);
4031
4032         if (IS_ERR(tlink->tl_tcon)) {
4033                 cifs_put_tlink(tlink);
4034                 return ERR_PTR(-EACCES);
4035         }
4036
4037         return tlink;
4038 }
4039
4040 /*
4041  * periodic workqueue job that scans tcon_tree for a superblock and closes
4042  * out tcons.
4043  */
4044 static void
4045 cifs_prune_tlinks(struct work_struct *work)
4046 {
4047         struct cifs_sb_info *cifs_sb = container_of(work, struct cifs_sb_info,
4048                                                     prune_tlinks.work);
4049         struct rb_root *root = &cifs_sb->tlink_tree;
4050         struct rb_node *node;
4051         struct rb_node *tmp;
4052         struct tcon_link *tlink;
4053
4054         /*
4055          * Because we drop the spinlock in the loop in order to put the tlink
4056          * it's not guarded against removal of links from the tree. The only
4057          * places that remove entries from the tree are this function and
4058          * umounts. Because this function is non-reentrant and is canceled
4059          * before umount can proceed, this is safe.
4060          */
4061         spin_lock(&cifs_sb->tlink_tree_lock);
4062         node = rb_first(root);
4063         while (node != NULL) {
4064                 tmp = node;
4065                 node = rb_next(tmp);
4066                 tlink = rb_entry(tmp, struct tcon_link, tl_rbnode);
4067
4068                 if (test_bit(TCON_LINK_MASTER, &tlink->tl_flags) ||
4069                     atomic_read(&tlink->tl_count) != 0 ||
4070                     time_after(tlink->tl_time + TLINK_IDLE_EXPIRE, jiffies))
4071                         continue;
4072
4073                 cifs_get_tlink(tlink);
4074                 clear_bit(TCON_LINK_IN_TREE, &tlink->tl_flags);
4075                 rb_erase(tmp, root);
4076
4077                 spin_unlock(&cifs_sb->tlink_tree_lock);
4078                 cifs_put_tlink(tlink);
4079                 spin_lock(&cifs_sb->tlink_tree_lock);
4080         }
4081         spin_unlock(&cifs_sb->tlink_tree_lock);
4082
4083         queue_delayed_work(cifsiod_wq, &cifs_sb->prune_tlinks,
4084                                 TLINK_IDLE_EXPIRE);
4085 }
4086
4087 #ifdef CONFIG_CIFS_DFS_UPCALL
4088 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4089 {
4090         int rc;
4091         struct TCP_Server_Info *server = tcon->ses->server;
4092         const struct smb_version_operations *ops = server->ops;
4093         struct dfs_cache_tgt_list tl;
4094         struct dfs_cache_tgt_iterator *it = NULL;
4095         char *tree;
4096         const char *tcp_host;
4097         size_t tcp_host_len;
4098         const char *dfs_host;
4099         size_t dfs_host_len;
4100         char *share = NULL, *prefix = NULL;
4101         struct dfs_info3_param ref = {0};
4102         bool isroot;
4103
4104         tree = kzalloc(MAX_TREE_SIZE, GFP_KERNEL);
4105         if (!tree)
4106                 return -ENOMEM;
4107
4108         if (!tcon->dfs_path) {
4109                 if (tcon->ipc) {
4110                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", server->hostname);
4111                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4112                 } else {
4113                         rc = ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4114                 }
4115                 goto out;
4116         }
4117
4118         rc = dfs_cache_noreq_find(tcon->dfs_path + 1, &ref, &tl);
4119         if (rc)
4120                 goto out;
4121         isroot = ref.server_type == DFS_TYPE_ROOT;
4122         free_dfs_info_param(&ref);
4123
4124         extract_unc_hostname(server->hostname, &tcp_host, &tcp_host_len);
4125
4126         for (it = dfs_cache_get_tgt_iterator(&tl); it; it = dfs_cache_get_next_tgt(&tl, it)) {
4127                 bool target_match;
4128
4129                 kfree(share);
4130                 kfree(prefix);
4131                 share = NULL;
4132                 prefix = NULL;
4133
4134                 rc = dfs_cache_get_tgt_share(tcon->dfs_path + 1, it, &share, &prefix);
4135                 if (rc) {
4136                         cifs_dbg(VFS, "%s: failed to parse target share %d\n",
4137                                  __func__, rc);
4138                         continue;
4139                 }
4140
4141                 extract_unc_hostname(share, &dfs_host, &dfs_host_len);
4142
4143                 if (dfs_host_len != tcp_host_len
4144                     || strncasecmp(dfs_host, tcp_host, dfs_host_len) != 0) {
4145                         cifs_dbg(FYI, "%s: %.*s doesn't match %.*s\n", __func__, (int)dfs_host_len,
4146                                  dfs_host, (int)tcp_host_len, tcp_host);
4147
4148                         rc = match_target_ip(server, dfs_host, dfs_host_len, &target_match);
4149                         if (rc) {
4150                                 cifs_dbg(VFS, "%s: failed to match target ip: %d\n", __func__, rc);
4151                                 break;
4152                         }
4153
4154                         if (!target_match) {
4155                                 cifs_dbg(FYI, "%s: skipping target\n", __func__);
4156                                 continue;
4157                         }
4158                 }
4159
4160                 if (tcon->ipc) {
4161                         scnprintf(tree, MAX_TREE_SIZE, "\\\\%s\\IPC$", share);
4162                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4163                 } else {
4164                         scnprintf(tree, MAX_TREE_SIZE, "\\%s", share);
4165                         rc = ops->tree_connect(xid, tcon->ses, tree, tcon, nlsc);
4166                         /* Only handle prefix paths of DFS link targets */
4167                         if (!rc && !isroot) {
4168                                 rc = update_super_prepath(tcon, prefix);
4169                                 break;
4170                         }
4171                 }
4172                 if (rc == -EREMOTE)
4173                         break;
4174         }
4175
4176         kfree(share);
4177         kfree(prefix);
4178
4179         if (!rc) {
4180                 if (it)
4181                         rc = dfs_cache_noreq_update_tgthint(tcon->dfs_path + 1, it);
4182                 else
4183                         rc = -ENOENT;
4184         }
4185         dfs_cache_free_tgts(&tl);
4186 out:
4187         kfree(tree);
4188         return rc;
4189 }
4190 #else
4191 int cifs_tree_connect(const unsigned int xid, struct cifs_tcon *tcon, const struct nls_table *nlsc)
4192 {
4193         const struct smb_version_operations *ops = tcon->ses->server->ops;
4194
4195         return ops->tree_connect(xid, tcon->ses, tcon->treeName, tcon, nlsc);
4196 }
4197 #endif