fs/cifs/smb2misc.c

   1 /*
   2  *   fs/cifs/smb2misc.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2002,2011
   5  *                 Etersoft, 2012
   6  *   Author(s): Steve French (sfrench@us.ibm.com)
   7  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
   8  *
   9  *   This library is free software; you can redistribute it and/or modify
  10  *   it under the terms of the GNU Lesser General Public License as published
  11  *   by the Free Software Foundation; either version 2.1 of the License, or
  12  *   (at your option) any later version.
  13  *
  14  *   This library is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  17  *   the GNU Lesser General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU Lesser General Public License
  20  *   along with this library; if not, write to the Free Software
  21  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  22  */
  23 #include <linux/ctype.h>
  24 #include "smb2pdu.h"
  25 #include "cifsglob.h"
  26 #include "cifsproto.h"
  27 #include "smb2proto.h"
  28 #include "cifs_debug.h"
  29 #include "cifs_unicode.h"
  30 #include "smb2status.h"
  31 #include "smb2glob.h"
  32
  33 static int
  34 check_smb2_hdr(struct smb2_sync_hdr *shdr, __u64 mid)
  35 {
  36         __u64 wire_mid = le64_to_cpu(shdr->MessageId);
  37
  38         /*
  39          * Make sure that this really is an SMB, that it is a response,
  40          * and that the message ids match.
  41          */
  42         if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
  43             (mid == wire_mid)) {
  44                 if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
  45                         return 0;
  46                 else {
  47                         /* only one valid case where server sends us request */
  48                         if (shdr->Command == SMB2_OPLOCK_BREAK)
  49                                 return 0;
  50                         else
  51                                 cifs_dbg(VFS, "Received Request not response\n");
  52                 }
  53         } else { /* bad signature or mid */
  54                 if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
  55                         cifs_dbg(VFS, "Bad protocol string signature header %x\n",
  56                                  le32_to_cpu(shdr->ProtocolId));
  57                 if (mid != wire_mid)
  58                         cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
  59                                  mid, wire_mid);
  60         }
  61         cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
  62         return 1;
  63 }
  64
  65 /*
  66  *  The following table defines the expected "StructureSize" of SMB2 responses
  67  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
  68  *
  69  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
  70  *  indexed by command in host byte order
  71  */
  72 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
  73         /* SMB2_NEGOTIATE */ cpu_to_le16(65),
  74         /* SMB2_SESSION_SETUP */ cpu_to_le16(9),
  75         /* SMB2_LOGOFF */ cpu_to_le16(4),
  76         /* SMB2_TREE_CONNECT */ cpu_to_le16(16),
  77         /* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
  78         /* SMB2_CREATE */ cpu_to_le16(89),
  79         /* SMB2_CLOSE */ cpu_to_le16(60),
  80         /* SMB2_FLUSH */ cpu_to_le16(4),
  81         /* SMB2_READ */ cpu_to_le16(17),
  82         /* SMB2_WRITE */ cpu_to_le16(17),
  83         /* SMB2_LOCK */ cpu_to_le16(4),
  84         /* SMB2_IOCTL */ cpu_to_le16(49),
  85         /* BB CHECK this ... not listed in documentation */
  86         /* SMB2_CANCEL */ cpu_to_le16(0),
  87         /* SMB2_ECHO */ cpu_to_le16(4),
  88         /* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
  89         /* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
  90         /* SMB2_QUERY_INFO */ cpu_to_le16(9),
  91         /* SMB2_SET_INFO */ cpu_to_le16(2),
  92         /* BB FIXME can also be 44 for lease break */
  93         /* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
  94 };
  95
  96 int
  97 smb2_check_message(char *buf, unsigned int length, struct TCP_Server_Info *srvr)
  98 {
  99         struct smb2_pdu *pdu = (struct smb2_pdu *)buf;
 100         struct smb2_hdr *hdr = &pdu->hdr;
 101         struct smb2_sync_hdr *shdr = get_sync_hdr(buf);
 102         __u64 mid;
 103         __u32 len = get_rfc1002_length(buf);
 104         __u32 clc_len;  /* calculated length */
 105         int command;
 106
 107         /* BB disable following printk later */
 108         cifs_dbg(FYI, "%s length: 0x%x, smb_buf_length: 0x%x\n",
 109                  __func__, length, len);
 110
 111         /*
 112          * Add function to do table lookup of StructureSize by command
 113          * ie Validate the wct via smb2_struct_sizes table above
 114          */
 115
 116         if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
 117                 struct smb2_transform_hdr *thdr =
 118                         (struct smb2_transform_hdr *)buf;
 119                 struct cifs_ses *ses = NULL;
 120                 struct list_head *tmp;
 121
 122                 /* decrypt frame now that it is completely read in */
 123                 spin_lock(&cifs_tcp_ses_lock);
 124                 list_for_each(tmp, &srvr->smb_ses_list) {
 125                         ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 126                         if (ses->Suid == thdr->SessionId)
 127                                 break;
 128
 129                         ses = NULL;
 130                 }
 131                 spin_unlock(&cifs_tcp_ses_lock);
 132                 if (ses == NULL) {
 133                         cifs_dbg(VFS, "no decryption - session id not found\n");
 134                         return 1;
 135                 }
 136         }
 137
 138         mid = le64_to_cpu(shdr->MessageId);
 139         if (length < sizeof(struct smb2_pdu)) {
 140                 if ((length >= sizeof(struct smb2_hdr))
 141                     && (shdr->Status != 0)) {
 142                         pdu->StructureSize2 = 0;
 143                         /*
 144                          * As with SMB/CIFS, on some error cases servers may
 145                          * not return wct properly
 146                          */
 147                         return 0;
 148                 } else {
 149                         cifs_dbg(VFS, "Length less than SMB header size\n");
 150                 }
 151                 return 1;
 152         }
 153         if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE - 4) {
 154                 cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
 155                          mid);
 156                 return 1;
 157         }
 158
 159         if (check_smb2_hdr(shdr, mid))
 160                 return 1;
 161
 162         if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
 163                 cifs_dbg(VFS, "Illegal structure size %u\n",
 164                          le16_to_cpu(shdr->StructureSize));
 165                 return 1;
 166         }
 167
 168         command = le16_to_cpu(shdr->Command);
 169         if (command >= NUMBER_OF_SMB2_COMMANDS) {
 170                 cifs_dbg(VFS, "Illegal SMB2 command %d\n", command);
 171                 return 1;
 172         }
 173
 174         if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
 175                 if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
 176                     pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
 177                         /* error packets have 9 byte structure size */
 178                         cifs_dbg(VFS, "Illegal response size %u for command %d\n",
 179                                  le16_to_cpu(pdu->StructureSize2), command);
 180                         return 1;
 181                 } else if (command == SMB2_OPLOCK_BREAK_HE
 182                            && (shdr->Status == 0)
 183                            && (le16_to_cpu(pdu->StructureSize2) != 44)
 184                            && (le16_to_cpu(pdu->StructureSize2) != 36)) {
 185                         /* special case for SMB2.1 lease break message */
 186                         cifs_dbg(VFS, "Illegal response size %d for oplock break\n",
 187                                  le16_to_cpu(pdu->StructureSize2));
 188                         return 1;
 189                 }
 190         }
 191
 192         if (4 + len != length) {
 193                 cifs_dbg(VFS, "Total length %u RFC1002 length %u mismatch mid %llu\n",
 194                          length, 4 + len, mid);
 195                 return 1;
 196         }
 197
 198         clc_len = smb2_calc_size(hdr);
 199
 200         if (4 + len != clc_len) {
 201                 cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
 202                          clc_len, 4 + len, mid);
 203                 /* create failed on symlink */
 204                 if (command == SMB2_CREATE_HE &&
 205                     shdr->Status == STATUS_STOPPED_ON_SYMLINK)
 206                         return 0;
 207                 /* Windows 7 server returns 24 bytes more */
 208                 if (clc_len + 20 == len && command == SMB2_OPLOCK_BREAK_HE)
 209                         return 0;
 210                 /* server can return one byte more due to implied bcc[0] */
 211                 if (clc_len == 4 + len + 1)
 212                         return 0;
 213
 214                 /*
 215                  * MacOS server pads after SMB2.1 write response with 3 bytes
 216                  * of junk. Other servers match RFC1001 len to actual
 217                  * SMB2/SMB3 frame length (header + smb2 response specific data)
 218                  * Log the server error (once), but allow it and continue
 219                  * since the frame is parseable.
 220                  */
 221                 if (clc_len < 4 /* RFC1001 header size */ + len) {
 222                         printk_once(KERN_WARNING
 223                                 "SMB2 server sent bad RFC1001 len %d not %d\n",
 224                                 len, clc_len - 4);
 225                         return 0;
 226                 }
 227
 228                 return 1;
 229         }
 230         return 0;
 231 }
 232
 233 /*
 234  * The size of the variable area depends on the offset and length fields
 235  * located in different fields for various SMB2 responses. SMB2 responses
 236  * with no variable length info, show an offset of zero for the offset field.
 237  */
 238 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
 239         /* SMB2_NEGOTIATE */ true,
 240         /* SMB2_SESSION_SETUP */ true,
 241         /* SMB2_LOGOFF */ false,
 242         /* SMB2_TREE_CONNECT */ false,
 243         /* SMB2_TREE_DISCONNECT */ false,
 244         /* SMB2_CREATE */ true,
 245         /* SMB2_CLOSE */ false,
 246         /* SMB2_FLUSH */ false,
 247         /* SMB2_READ */ true,
 248         /* SMB2_WRITE */ false,
 249         /* SMB2_LOCK */ false,
 250         /* SMB2_IOCTL */ true,
 251         /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
 252         /* SMB2_ECHO */ false,
 253         /* SMB2_QUERY_DIRECTORY */ true,
 254         /* SMB2_CHANGE_NOTIFY */ true,
 255         /* SMB2_QUERY_INFO */ true,
 256         /* SMB2_SET_INFO */ false,
 257         /* SMB2_OPLOCK_BREAK */ false
 258 };
 259
 260 /*
 261  * Returns the pointer to the beginning of the data area. Length of the data
 262  * area and the offset to it (from the beginning of the smb are also returned.
 263  */
 264 char *
 265 smb2_get_data_area_len(int *off, int *len, struct smb2_hdr *hdr)
 266 {
 267         struct smb2_sync_hdr *shdr = get_sync_hdr(hdr);
 268         *off = 0;
 269         *len = 0;
 270
 271         /* error responses do not have data area */
 272         if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
 273             (((struct smb2_err_rsp *)hdr)->StructureSize) ==
 274                                                 SMB2_ERROR_STRUCTURE_SIZE2)
 275                 return NULL;
 276
 277         /*
 278          * Following commands have data areas so we have to get the location
 279          * of the data buffer offset and data buffer length for the particular
 280          * command.
 281          */
 282         switch (shdr->Command) {
 283         case SMB2_NEGOTIATE:
 284                 *off = le16_to_cpu(
 285                     ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferOffset);
 286                 *len = le16_to_cpu(
 287                     ((struct smb2_negotiate_rsp *)hdr)->SecurityBufferLength);
 288                 break;
 289         case SMB2_SESSION_SETUP:
 290                 *off = le16_to_cpu(
 291                     ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferOffset);
 292                 *len = le16_to_cpu(
 293                     ((struct smb2_sess_setup_rsp *)hdr)->SecurityBufferLength);
 294                 break;
 295         case SMB2_CREATE:
 296                 *off = le32_to_cpu(
 297                     ((struct smb2_create_rsp *)hdr)->CreateContextsOffset);
 298                 *len = le32_to_cpu(
 299                     ((struct smb2_create_rsp *)hdr)->CreateContextsLength);
 300                 break;
 301         case SMB2_QUERY_INFO:
 302                 *off = le16_to_cpu(
 303                     ((struct smb2_query_info_rsp *)hdr)->OutputBufferOffset);
 304                 *len = le32_to_cpu(
 305                     ((struct smb2_query_info_rsp *)hdr)->OutputBufferLength);
 306                 break;
 307         case SMB2_READ:
 308                 *off = ((struct smb2_read_rsp *)hdr)->DataOffset;
 309                 *len = le32_to_cpu(((struct smb2_read_rsp *)hdr)->DataLength);
 310                 break;
 311         case SMB2_QUERY_DIRECTORY:
 312                 *off = le16_to_cpu(
 313                   ((struct smb2_query_directory_rsp *)hdr)->OutputBufferOffset);
 314                 *len = le32_to_cpu(
 315                   ((struct smb2_query_directory_rsp *)hdr)->OutputBufferLength);
 316                 break;
 317         case SMB2_IOCTL:
 318                 *off = le32_to_cpu(
 319                   ((struct smb2_ioctl_rsp *)hdr)->OutputOffset);
 320                 *len = le32_to_cpu(((struct smb2_ioctl_rsp *)hdr)->OutputCount);
 321                 break;
 322         case SMB2_CHANGE_NOTIFY:
 323         default:
 324                 /* BB FIXME for unimplemented cases above */
 325                 cifs_dbg(VFS, "no length check for command\n");
 326                 break;
 327         }
 328
 329         /*
 330          * Invalid length or offset probably means data area is invalid, but
 331          * we have little choice but to ignore the data area in this case.
 332          */
 333         if (*off > 4096) {
 334                 cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
 335                 *len = 0;
 336                 *off = 0;
 337         } else if (*off < 0) {
 338                 cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
 339                          *off);
 340                 *off = 0;
 341                 *len = 0;
 342         } else if (*len < 0) {
 343                 cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
 344                          *len);
 345                 *len = 0;
 346         } else if (*len > 128 * 1024) {
 347                 cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
 348                 *len = 0;
 349         }
 350
 351         /* return pointer to beginning of data area, ie offset from SMB start */
 352         if ((*off != 0) && (*len != 0))
 353                 return (char *)shdr + *off;
 354         else
 355                 return NULL;
 356 }
 357
 358 /*
 359  * Calculate the size of the SMB message based on the fixed header
 360  * portion, the number of word parameters and the data portion of the message.
 361  */
 362 unsigned int
 363 smb2_calc_size(void *buf)
 364 {
 365         struct smb2_pdu *pdu = (struct smb2_pdu *)buf;
 366         struct smb2_hdr *hdr = &pdu->hdr;
 367         struct smb2_sync_hdr *shdr = get_sync_hdr(hdr);
 368         int offset; /* the offset from the beginning of SMB to data area */
 369         int data_length; /* the length of the variable length data area */
 370         /* Structure Size has already been checked to make sure it is 64 */
 371         int len = 4 + le16_to_cpu(shdr->StructureSize);
 372
 373         /*
 374          * StructureSize2, ie length of fixed parameter area has already
 375          * been checked to make sure it is the correct length.
 376          */
 377         len += le16_to_cpu(pdu->StructureSize2);
 378
 379         if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
 380                 goto calc_size_exit;
 381
 382         smb2_get_data_area_len(&offset, &data_length, hdr);
 383         cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
 384
 385         if (data_length > 0) {
 386                 /*
 387                  * Check to make sure that data area begins after fixed area,
 388                  * Note that last byte of the fixed area is part of data area
 389                  * for some commands, typically those with odd StructureSize,
 390                  * so we must add one to the calculation (and 4 to account for
 391                  * the size of the RFC1001 hdr.
 392                  */
 393                 if (offset + 4 + 1 < len) {
 394                         cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
 395                                  offset + 4 + 1, len);
 396                         data_length = 0;
 397                 } else {
 398                         len = 4 + offset + data_length;
 399                 }
 400         }
 401 calc_size_exit:
 402         cifs_dbg(FYI, "SMB2 len %d\n", len);
 403         return len;
 404 }
 405
 406 /* Note: caller must free return buffer */
 407 __le16 *
 408 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
 409 {
 410         int len;
 411         const char *start_of_path;
 412         __le16 *to;
 413         int map_type;
 414
 415         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
 416                 map_type = SFM_MAP_UNI_RSVD;
 417         else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
 418                 map_type = SFU_MAP_UNI_RSVD;
 419         else
 420                 map_type = NO_MAP_UNI_RSVD;
 421
 422         /* Windows doesn't allow paths beginning with \ */
 423         if (from[0] == '\\')
 424                 start_of_path = from + 1;
 425         else
 426                 start_of_path = from;
 427         to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
 428                                    cifs_sb->local_nls, map_type);
 429         return to;
 430 }
 431
 432 __le32
 433 smb2_get_lease_state(struct cifsInodeInfo *cinode)
 434 {
 435         __le32 lease = 0;
 436
 437         if (CIFS_CACHE_WRITE(cinode))
 438                 lease |= SMB2_LEASE_WRITE_CACHING;
 439         if (CIFS_CACHE_HANDLE(cinode))
 440                 lease |= SMB2_LEASE_HANDLE_CACHING;
 441         if (CIFS_CACHE_READ(cinode))
 442                 lease |= SMB2_LEASE_READ_CACHING;
 443         return lease;
 444 }
 445
 446 struct smb2_lease_break_work {
 447         struct work_struct lease_break;
 448         struct tcon_link *tlink;
 449         __u8 lease_key[16];
 450         __le32 lease_state;
 451 };
 452
 453 static void
 454 cifs_ses_oplock_break(struct work_struct *work)
 455 {
 456         struct smb2_lease_break_work *lw = container_of(work,
 457                                 struct smb2_lease_break_work, lease_break);
 458         int rc;
 459
 460         rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
 461                               lw->lease_state);
 462         cifs_dbg(FYI, "Lease release rc %d\n", rc);
 463         cifs_put_tlink(lw->tlink);
 464         kfree(lw);
 465 }
 466
 467 static bool
 468 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp,
 469                     struct smb2_lease_break_work *lw)
 470 {
 471         bool found;
 472         __u8 lease_state;
 473         struct list_head *tmp;
 474         struct cifsFileInfo *cfile;
 475         struct TCP_Server_Info *server = tcon->ses->server;
 476         struct cifs_pending_open *open;
 477         struct cifsInodeInfo *cinode;
 478         int ack_req = le32_to_cpu(rsp->Flags &
 479                                   SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
 480
 481         lease_state = le32_to_cpu(rsp->NewLeaseState);
 482
 483         list_for_each(tmp, &tcon->openFileList) {
 484                 cfile = list_entry(tmp, struct cifsFileInfo, tlist);
 485                 cinode = CIFS_I(d_inode(cfile->dentry));
 486
 487                 if (memcmp(cinode->lease_key, rsp->LeaseKey,
 488                                                         SMB2_LEASE_KEY_SIZE))
 489                         continue;
 490
 491                 cifs_dbg(FYI, "found in the open list\n");
 492                 cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
 493                          le32_to_cpu(rsp->NewLeaseState));
 494
 495                 server->ops->set_oplock_level(cinode, lease_state, 0, NULL);
 496
 497                 if (ack_req)
 498                         cfile->oplock_break_cancelled = false;
 499                 else
 500                         cfile->oplock_break_cancelled = true;
 501
 502                 queue_work(cifsiod_wq, &cfile->oplock_break);
 503                 kfree(lw);
 504                 return true;
 505         }
 506
 507         found = false;
 508         list_for_each_entry(open, &tcon->pending_opens, olist) {
 509                 if (memcmp(open->lease_key, rsp->LeaseKey,
 510                            SMB2_LEASE_KEY_SIZE))
 511                         continue;
 512
 513                 if (!found && ack_req) {
 514                         found = true;
 515                         memcpy(lw->lease_key, open->lease_key,
 516                                SMB2_LEASE_KEY_SIZE);
 517                         lw->tlink = cifs_get_tlink(open->tlink);
 518                         queue_work(cifsiod_wq, &lw->lease_break);
 519                 }
 520
 521                 cifs_dbg(FYI, "found in the pending open list\n");
 522                 cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
 523                          le32_to_cpu(rsp->NewLeaseState));
 524
 525                 open->oplock = lease_state;
 526         }
 527         return found;
 528 }
 529
 530 static bool
 531 smb2_is_valid_lease_break(char *buffer)
 532 {
 533         struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
 534         struct list_head *tmp, *tmp1, *tmp2;
 535         struct TCP_Server_Info *server;
 536         struct cifs_ses *ses;
 537         struct cifs_tcon *tcon;
 538         struct smb2_lease_break_work *lw;
 539
 540         lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
 541         if (!lw)
 542                 return false;
 543
 544         INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
 545         lw->lease_state = rsp->NewLeaseState;
 546
 547         cifs_dbg(FYI, "Checking for lease break\n");
 548
 549         /* look up tcon based on tid & uid */
 550         spin_lock(&cifs_tcp_ses_lock);
 551         list_for_each(tmp, &cifs_tcp_ses_list) {
 552                 server = list_entry(tmp, struct TCP_Server_Info, tcp_ses_list);
 553
 554                 list_for_each(tmp1, &server->smb_ses_list) {
 555                         ses = list_entry(tmp1, struct cifs_ses, smb_ses_list);
 556
 557                         list_for_each(tmp2, &ses->tcon_list) {
 558                                 tcon = list_entry(tmp2, struct cifs_tcon,
 559                                                   tcon_list);
 560                                 spin_lock(&tcon->open_file_lock);
 561                                 cifs_stats_inc(
 562                                     &tcon->stats.cifs_stats.num_oplock_brks);
 563                                 if (smb2_tcon_has_lease(tcon, rsp, lw)) {
 564                                         spin_unlock(&tcon->open_file_lock);
 565                                         spin_unlock(&cifs_tcp_ses_lock);
 566                                         return true;
 567                                 }
 568                                 spin_unlock(&tcon->open_file_lock);
 569                         }
 570                 }
 571         }
 572         spin_unlock(&cifs_tcp_ses_lock);
 573         kfree(lw);
 574         cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
 575         return false;
 576 }
 577
 578 bool
 579 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 580 {
 581         struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
 582         struct list_head *tmp, *tmp1, *tmp2;
 583         struct cifs_ses *ses;
 584         struct cifs_tcon *tcon;
 585         struct cifsInodeInfo *cinode;
 586         struct cifsFileInfo *cfile;
 587
 588         cifs_dbg(FYI, "Checking for oplock break\n");
 589
 590         if (rsp->hdr.sync_hdr.Command != SMB2_OPLOCK_BREAK)
 591                 return false;
 592
 593         if (rsp->StructureSize !=
 594                                 smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 595                 if (le16_to_cpu(rsp->StructureSize) == 44)
 596                         return smb2_is_valid_lease_break(buffer);
 597                 else
 598                         return false;
 599         }
 600
 601         cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
 602
 603         /* look up tcon based on tid & uid */
 604         spin_lock(&cifs_tcp_ses_lock);
 605         list_for_each(tmp, &server->smb_ses_list) {
 606                 ses = list_entry(tmp, struct cifs_ses, smb_ses_list);
 607                 list_for_each(tmp1, &ses->tcon_list) {
 608                         tcon = list_entry(tmp1, struct cifs_tcon, tcon_list);
 609
 610                         cifs_stats_inc(&tcon->stats.cifs_stats.num_oplock_brks);
 611                         spin_lock(&tcon->open_file_lock);
 612                         list_for_each(tmp2, &tcon->openFileList) {
 613                                 cfile = list_entry(tmp2, struct cifsFileInfo,
 614                                                      tlist);
 615                                 if (rsp->PersistentFid !=
 616                                     cfile->fid.persistent_fid ||
 617                                     rsp->VolatileFid !=
 618                                     cfile->fid.volatile_fid)
 619                                         continue;
 620
 621                                 cifs_dbg(FYI, "file id match, oplock break\n");
 622                                 cinode = CIFS_I(d_inode(cfile->dentry));
 623                                 spin_lock(&cfile->file_info_lock);
 624                                 if (!CIFS_CACHE_WRITE(cinode) &&
 625                                     rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
 626                                         cfile->oplock_break_cancelled = true;
 627                                 else
 628                                         cfile->oplock_break_cancelled = false;
 629
 630                                 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
 631                                         &cinode->flags);
 632
 633                                 /*
 634                                  * Set flag if the server downgrades the oplock
 635                                  * to L2 else clear.
 636                                  */
 637                                 if (rsp->OplockLevel)
 638                                         set_bit(
 639                                            CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
 640                                            &cinode->flags);
 641                                 else
 642                                         clear_bit(
 643                                            CIFS_INODE_DOWNGRADE_OPLOCK_TO_L2,
 644                                            &cinode->flags);
 645                                 spin_unlock(&cfile->file_info_lock);
 646                                 queue_work(cifsiod_wq, &cfile->oplock_break);
 647
 648                                 spin_unlock(&tcon->open_file_lock);
 649                                 spin_unlock(&cifs_tcp_ses_lock);
 650                                 return true;
 651                         }
 652                         spin_unlock(&tcon->open_file_lock);
 653                         spin_unlock(&cifs_tcp_ses_lock);
 654                         cifs_dbg(FYI, "No matching file for oplock break\n");
 655                         return true;
 656                 }
 657         }
 658         spin_unlock(&cifs_tcp_ses_lock);
 659         cifs_dbg(FYI, "Can not process oplock break for non-existent connection\n");
 660         return false;
 661 }
 662
 663 void
 664 smb2_cancelled_close_fid(struct work_struct *work)
 665 {
 666         struct close_cancelled_open *cancelled = container_of(work,
 667                                         struct close_cancelled_open, work);
 668
 669         cifs_dbg(VFS, "Close unmatched open\n");
 670
 671         SMB2_close(0, cancelled->tcon, cancelled->fid.persistent_fid,
 672                    cancelled->fid.volatile_fid);
 673         cifs_put_tcon(cancelled->tcon);
 674         kfree(cancelled);
 675 }
 676
 677 int
 678 smb2_handle_cancelled_mid(char *buffer, struct TCP_Server_Info *server)
 679 {
 680         struct smb2_sync_hdr *sync_hdr = get_sync_hdr(buffer);
 681         struct smb2_create_rsp *rsp = (struct smb2_create_rsp *)buffer;
 682         struct cifs_tcon *tcon;
 683         struct close_cancelled_open *cancelled;
 684
 685         if (sync_hdr->Command != SMB2_CREATE ||
 686             sync_hdr->Status != STATUS_SUCCESS)
 687                 return 0;
 688
 689         cancelled = kzalloc(sizeof(*cancelled), GFP_KERNEL);
 690         if (!cancelled)
 691                 return -ENOMEM;
 692
 693         tcon = smb2_find_smb_tcon(server, sync_hdr->SessionId,
 694                                   sync_hdr->TreeId);
 695         if (!tcon) {
 696                 kfree(cancelled);
 697                 return -ENOENT;
 698         }
 699
 700         cancelled->fid.persistent_fid = rsp->PersistentFileId;
 701         cancelled->fid.volatile_fid = rsp->VolatileFileId;
 702         cancelled->tcon = tcon;
 703         INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
 704         queue_work(cifsiod_wq, &cancelled->work);
 705
 706         return 0;
 707 }