fs/cifs/smb2misc.c

   1 // SPDX-License-Identifier: LGPL-2.1
   2 /*
   3  *   fs/cifs/smb2misc.c
   4  *
   5  *   Copyright (C) International Business Machines  Corp., 2002,2011
   6  *                 Etersoft, 2012
   7  *   Author(s): Steve French (sfrench@us.ibm.com)
   8  *              Pavel Shilovsky (pshilovsky@samba.org) 2012
   9  *
  10  */
  11 #include <linux/ctype.h>
  12 #include "smb2pdu.h"
  13 #include "cifsglob.h"
  14 #include "cifsproto.h"
  15 #include "smb2proto.h"
  16 #include "cifs_debug.h"
  17 #include "cifs_unicode.h"
  18 #include "smb2status.h"
  19 #include "smb2glob.h"
  20 #include "nterr.h"
  21
  22 static int
  23 check_smb2_hdr(struct smb2_sync_hdr *shdr, __u64 mid)
  24 {
  25         __u64 wire_mid = le64_to_cpu(shdr->MessageId);
  26
  27         /*
  28          * Make sure that this really is an SMB, that it is a response,
  29          * and that the message ids match.
  30          */
  31         if ((shdr->ProtocolId == SMB2_PROTO_NUMBER) &&
  32             (mid == wire_mid)) {
  33                 if (shdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
  34                         return 0;
  35                 else {
  36                         /* only one valid case where server sends us request */
  37                         if (shdr->Command == SMB2_OPLOCK_BREAK)
  38                                 return 0;
  39                         else
  40                                 cifs_dbg(VFS, "Received Request not response\n");
  41                 }
  42         } else { /* bad signature or mid */
  43                 if (shdr->ProtocolId != SMB2_PROTO_NUMBER)
  44                         cifs_dbg(VFS, "Bad protocol string signature header %x\n",
  45                                  le32_to_cpu(shdr->ProtocolId));
  46                 if (mid != wire_mid)
  47                         cifs_dbg(VFS, "Mids do not match: %llu and %llu\n",
  48                                  mid, wire_mid);
  49         }
  50         cifs_dbg(VFS, "Bad SMB detected. The Mid=%llu\n", wire_mid);
  51         return 1;
  52 }
  53
  54 /*
  55  *  The following table defines the expected "StructureSize" of SMB2 responses
  56  *  in order by SMB2 command.  This is similar to "wct" in SMB/CIFS responses.
  57  *
  58  *  Note that commands are defined in smb2pdu.h in le16 but the array below is
  59  *  indexed by command in host byte order
  60  */
  61 static const __le16 smb2_rsp_struct_sizes[NUMBER_OF_SMB2_COMMANDS] = {
  62         /* SMB2_NEGOTIATE */ cpu_to_le16(65),
  63         /* SMB2_SESSION_SETUP */ cpu_to_le16(9),
  64         /* SMB2_LOGOFF */ cpu_to_le16(4),
  65         /* SMB2_TREE_CONNECT */ cpu_to_le16(16),
  66         /* SMB2_TREE_DISCONNECT */ cpu_to_le16(4),
  67         /* SMB2_CREATE */ cpu_to_le16(89),
  68         /* SMB2_CLOSE */ cpu_to_le16(60),
  69         /* SMB2_FLUSH */ cpu_to_le16(4),
  70         /* SMB2_READ */ cpu_to_le16(17),
  71         /* SMB2_WRITE */ cpu_to_le16(17),
  72         /* SMB2_LOCK */ cpu_to_le16(4),
  73         /* SMB2_IOCTL */ cpu_to_le16(49),
  74         /* BB CHECK this ... not listed in documentation */
  75         /* SMB2_CANCEL */ cpu_to_le16(0),
  76         /* SMB2_ECHO */ cpu_to_le16(4),
  77         /* SMB2_QUERY_DIRECTORY */ cpu_to_le16(9),
  78         /* SMB2_CHANGE_NOTIFY */ cpu_to_le16(9),
  79         /* SMB2_QUERY_INFO */ cpu_to_le16(9),
  80         /* SMB2_SET_INFO */ cpu_to_le16(2),
  81         /* BB FIXME can also be 44 for lease break */
  82         /* SMB2_OPLOCK_BREAK */ cpu_to_le16(24)
  83 };
  84
  85 #define SMB311_NEGPROT_BASE_SIZE (sizeof(struct smb2_sync_hdr) + sizeof(struct smb2_negotiate_rsp))
  86
  87 static __u32 get_neg_ctxt_len(struct smb2_sync_hdr *hdr, __u32 len,
  88                               __u32 non_ctxlen)
  89 {
  90         __u16 neg_count;
  91         __u32 nc_offset, size_of_pad_before_neg_ctxts;
  92         struct smb2_negotiate_rsp *pneg_rsp = (struct smb2_negotiate_rsp *)hdr;
  93
  94         /* Negotiate contexts are only valid for latest dialect SMB3.11 */
  95         neg_count = le16_to_cpu(pneg_rsp->NegotiateContextCount);
  96         if ((neg_count == 0) ||
  97            (pneg_rsp->DialectRevision != cpu_to_le16(SMB311_PROT_ID)))
  98                 return 0;
  99
 100         /*
 101          * if SPNEGO blob present (ie the RFC2478 GSS info which indicates
 102          * which security mechanisms the server supports) make sure that
 103          * the negotiate contexts start after it
 104          */
 105         nc_offset = le32_to_cpu(pneg_rsp->NegotiateContextOffset);
 106         /*
 107          * non_ctxlen is at least shdr->StructureSize + pdu->StructureSize2
 108          * and the latter is 1 byte bigger than the fix-sized area of the
 109          * NEGOTIATE response
 110          */
 111         if (nc_offset + 1 < non_ctxlen) {
 112                 pr_warn_once("Invalid negotiate context offset %d\n", nc_offset);
 113                 return 0;
 114         } else if (nc_offset + 1 == non_ctxlen) {
 115                 cifs_dbg(FYI, "no SPNEGO security blob in negprot rsp\n");
 116                 size_of_pad_before_neg_ctxts = 0;
 117         } else if (non_ctxlen == SMB311_NEGPROT_BASE_SIZE)
 118                 /* has padding, but no SPNEGO blob */
 119                 size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen + 1;
 120         else
 121                 size_of_pad_before_neg_ctxts = nc_offset - non_ctxlen;
 122
 123         /* Verify that at least minimal negotiate contexts fit within frame */
 124         if (len < nc_offset + (neg_count * sizeof(struct smb2_neg_context))) {
 125                 pr_warn_once("negotiate context goes beyond end\n");
 126                 return 0;
 127         }
 128
 129         cifs_dbg(FYI, "length of negcontexts %d pad %d\n",
 130                 len - nc_offset, size_of_pad_before_neg_ctxts);
 131
 132         /* length of negcontexts including pad from end of sec blob to them */
 133         return (len - nc_offset) + size_of_pad_before_neg_ctxts;
 134 }
 135
 136 int
 137 smb2_check_message(char *buf, unsigned int len, struct TCP_Server_Info *srvr)
 138 {
 139         struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;
 140         struct smb2_sync_pdu *pdu = (struct smb2_sync_pdu *)shdr;
 141         __u64 mid;
 142         __u32 clc_len;  /* calculated length */
 143         int command;
 144         int pdu_size = sizeof(struct smb2_sync_pdu);
 145         int hdr_size = sizeof(struct smb2_sync_hdr);
 146
 147         /*
 148          * Add function to do table lookup of StructureSize by command
 149          * ie Validate the wct via smb2_struct_sizes table above
 150          */
 151         if (shdr->ProtocolId == SMB2_TRANSFORM_PROTO_NUM) {
 152                 struct smb2_transform_hdr *thdr =
 153                         (struct smb2_transform_hdr *)buf;
 154                 struct cifs_ses *ses = NULL;
 155
 156                 /* decrypt frame now that it is completely read in */
 157                 spin_lock(&cifs_tcp_ses_lock);
 158                 list_for_each_entry(ses, &srvr->smb_ses_list, smb_ses_list) {
 159                         if (ses->Suid == thdr->SessionId)
 160                                 break;
 161                 }
 162                 spin_unlock(&cifs_tcp_ses_lock);
 163                 if (list_entry_is_head(ses, &srvr->smb_ses_list,
 164                                        smb_ses_list)) {
 165                         cifs_dbg(VFS, "no decryption - session id not found\n");
 166                         return 1;
 167                 }
 168         }
 169
 170         mid = le64_to_cpu(shdr->MessageId);
 171         if (len < pdu_size) {
 172                 if ((len >= hdr_size)
 173                     && (shdr->Status != 0)) {
 174                         pdu->StructureSize2 = 0;
 175                         /*
 176                          * As with SMB/CIFS, on some error cases servers may
 177                          * not return wct properly
 178                          */
 179                         return 0;
 180                 } else {
 181                         cifs_dbg(VFS, "Length less than SMB header size\n");
 182                 }
 183                 return 1;
 184         }
 185         if (len > CIFSMaxBufSize + MAX_SMB2_HDR_SIZE) {
 186                 cifs_dbg(VFS, "SMB length greater than maximum, mid=%llu\n",
 187                          mid);
 188                 return 1;
 189         }
 190
 191         if (check_smb2_hdr(shdr, mid))
 192                 return 1;
 193
 194         if (shdr->StructureSize != SMB2_HEADER_STRUCTURE_SIZE) {
 195                 cifs_dbg(VFS, "Invalid structure size %u\n",
 196                          le16_to_cpu(shdr->StructureSize));
 197                 return 1;
 198         }
 199
 200         command = le16_to_cpu(shdr->Command);
 201         if (command >= NUMBER_OF_SMB2_COMMANDS) {
 202                 cifs_dbg(VFS, "Invalid SMB2 command %d\n", command);
 203                 return 1;
 204         }
 205
 206         if (smb2_rsp_struct_sizes[command] != pdu->StructureSize2) {
 207                 if (command != SMB2_OPLOCK_BREAK_HE && (shdr->Status == 0 ||
 208                     pdu->StructureSize2 != SMB2_ERROR_STRUCTURE_SIZE2)) {
 209                         /* error packets have 9 byte structure size */
 210                         cifs_dbg(VFS, "Invalid response size %u for command %d\n",
 211                                  le16_to_cpu(pdu->StructureSize2), command);
 212                         return 1;
 213                 } else if (command == SMB2_OPLOCK_BREAK_HE
 214                            && (shdr->Status == 0)
 215                            && (le16_to_cpu(pdu->StructureSize2) != 44)
 216                            && (le16_to_cpu(pdu->StructureSize2) != 36)) {
 217                         /* special case for SMB2.1 lease break message */
 218                         cifs_dbg(VFS, "Invalid response size %d for oplock break\n",
 219                                  le16_to_cpu(pdu->StructureSize2));
 220                         return 1;
 221                 }
 222         }
 223
 224         clc_len = smb2_calc_size(buf, srvr);
 225
 226         if (shdr->Command == SMB2_NEGOTIATE)
 227                 clc_len += get_neg_ctxt_len(shdr, len, clc_len);
 228
 229         if (len != clc_len) {
 230                 cifs_dbg(FYI, "Calculated size %u length %u mismatch mid %llu\n",
 231                          clc_len, len, mid);
 232                 /* create failed on symlink */
 233                 if (command == SMB2_CREATE_HE &&
 234                     shdr->Status == STATUS_STOPPED_ON_SYMLINK)
 235                         return 0;
 236                 /* Windows 7 server returns 24 bytes more */
 237                 if (clc_len + 24 == len && command == SMB2_OPLOCK_BREAK_HE)
 238                         return 0;
 239                 /* server can return one byte more due to implied bcc[0] */
 240                 if (clc_len == len + 1)
 241                         return 0;
 242
 243                 /*
 244                  * Some windows servers (win2016) will pad also the final
 245                  * PDU in a compound to 8 bytes.
 246                  */
 247                 if (((clc_len + 7) & ~7) == len)
 248                         return 0;
 249
 250                 /*
 251                  * MacOS server pads after SMB2.1 write response with 3 bytes
 252                  * of junk. Other servers match RFC1001 len to actual
 253                  * SMB2/SMB3 frame length (header + smb2 response specific data)
 254                  * Some windows servers also pad up to 8 bytes when compounding.
 255                  */
 256                 if (clc_len < len)
 257                         return 0;
 258
 259                 pr_warn_once(
 260                         "srv rsp too short, len %d not %d. cmd:%d mid:%llu\n",
 261                         len, clc_len, command, mid);
 262
 263                 return 1;
 264         }
 265         return 0;
 266 }
 267
 268 /*
 269  * The size of the variable area depends on the offset and length fields
 270  * located in different fields for various SMB2 responses. SMB2 responses
 271  * with no variable length info, show an offset of zero for the offset field.
 272  */
 273 static const bool has_smb2_data_area[NUMBER_OF_SMB2_COMMANDS] = {
 274         /* SMB2_NEGOTIATE */ true,
 275         /* SMB2_SESSION_SETUP */ true,
 276         /* SMB2_LOGOFF */ false,
 277         /* SMB2_TREE_CONNECT */ false,
 278         /* SMB2_TREE_DISCONNECT */ false,
 279         /* SMB2_CREATE */ true,
 280         /* SMB2_CLOSE */ false,
 281         /* SMB2_FLUSH */ false,
 282         /* SMB2_READ */ true,
 283         /* SMB2_WRITE */ false,
 284         /* SMB2_LOCK */ false,
 285         /* SMB2_IOCTL */ true,
 286         /* SMB2_CANCEL */ false, /* BB CHECK this not listed in documentation */
 287         /* SMB2_ECHO */ false,
 288         /* SMB2_QUERY_DIRECTORY */ true,
 289         /* SMB2_CHANGE_NOTIFY */ true,
 290         /* SMB2_QUERY_INFO */ true,
 291         /* SMB2_SET_INFO */ false,
 292         /* SMB2_OPLOCK_BREAK */ false
 293 };
 294
 295 /*
 296  * Returns the pointer to the beginning of the data area. Length of the data
 297  * area and the offset to it (from the beginning of the smb are also returned.
 298  */
 299 char *
 300 smb2_get_data_area_len(int *off, int *len, struct smb2_sync_hdr *shdr)
 301 {
 302         *off = 0;
 303         *len = 0;
 304
 305         /* error responses do not have data area */
 306         if (shdr->Status && shdr->Status != STATUS_MORE_PROCESSING_REQUIRED &&
 307             (((struct smb2_err_rsp *)shdr)->StructureSize) ==
 308                                                 SMB2_ERROR_STRUCTURE_SIZE2)
 309                 return NULL;
 310
 311         /*
 312          * Following commands have data areas so we have to get the location
 313          * of the data buffer offset and data buffer length for the particular
 314          * command.
 315          */
 316         switch (shdr->Command) {
 317         case SMB2_NEGOTIATE:
 318                 *off = le16_to_cpu(
 319                   ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferOffset);
 320                 *len = le16_to_cpu(
 321                   ((struct smb2_negotiate_rsp *)shdr)->SecurityBufferLength);
 322                 break;
 323         case SMB2_SESSION_SETUP:
 324                 *off = le16_to_cpu(
 325                   ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferOffset);
 326                 *len = le16_to_cpu(
 327                   ((struct smb2_sess_setup_rsp *)shdr)->SecurityBufferLength);
 328                 break;
 329         case SMB2_CREATE:
 330                 *off = le32_to_cpu(
 331                     ((struct smb2_create_rsp *)shdr)->CreateContextsOffset);
 332                 *len = le32_to_cpu(
 333                     ((struct smb2_create_rsp *)shdr)->CreateContextsLength);
 334                 break;
 335         case SMB2_QUERY_INFO:
 336                 *off = le16_to_cpu(
 337                     ((struct smb2_query_info_rsp *)shdr)->OutputBufferOffset);
 338                 *len = le32_to_cpu(
 339                     ((struct smb2_query_info_rsp *)shdr)->OutputBufferLength);
 340                 break;
 341         case SMB2_READ:
 342                 /* TODO: is this a bug ? */
 343                 *off = ((struct smb2_read_rsp *)shdr)->DataOffset;
 344                 *len = le32_to_cpu(((struct smb2_read_rsp *)shdr)->DataLength);
 345                 break;
 346         case SMB2_QUERY_DIRECTORY:
 347                 *off = le16_to_cpu(
 348                   ((struct smb2_query_directory_rsp *)shdr)->OutputBufferOffset);
 349                 *len = le32_to_cpu(
 350                   ((struct smb2_query_directory_rsp *)shdr)->OutputBufferLength);
 351                 break;
 352         case SMB2_IOCTL:
 353                 *off = le32_to_cpu(
 354                   ((struct smb2_ioctl_rsp *)shdr)->OutputOffset);
 355                 *len = le32_to_cpu(
 356                   ((struct smb2_ioctl_rsp *)shdr)->OutputCount);
 357                 break;
 358         case SMB2_CHANGE_NOTIFY:
 359                 *off = le16_to_cpu(
 360                   ((struct smb2_change_notify_rsp *)shdr)->OutputBufferOffset);
 361                 *len = le32_to_cpu(
 362                   ((struct smb2_change_notify_rsp *)shdr)->OutputBufferLength);
 363                 break;
 364         default:
 365                 cifs_dbg(VFS, "no length check for command %d\n", le16_to_cpu(shdr->Command));
 366                 break;
 367         }
 368
 369         /*
 370          * Invalid length or offset probably means data area is invalid, but
 371          * we have little choice but to ignore the data area in this case.
 372          */
 373         if (*off > 4096) {
 374                 cifs_dbg(VFS, "offset %d too large, data area ignored\n", *off);
 375                 *len = 0;
 376                 *off = 0;
 377         } else if (*off < 0) {
 378                 cifs_dbg(VFS, "negative offset %d to data invalid ignore data area\n",
 379                          *off);
 380                 *off = 0;
 381                 *len = 0;
 382         } else if (*len < 0) {
 383                 cifs_dbg(VFS, "negative data length %d invalid, data area ignored\n",
 384                          *len);
 385                 *len = 0;
 386         } else if (*len > 128 * 1024) {
 387                 cifs_dbg(VFS, "data area larger than 128K: %d\n", *len);
 388                 *len = 0;
 389         }
 390
 391         /* return pointer to beginning of data area, ie offset from SMB start */
 392         if ((*off != 0) && (*len != 0))
 393                 return (char *)shdr + *off;
 394         else
 395                 return NULL;
 396 }
 397
 398 /*
 399  * Calculate the size of the SMB message based on the fixed header
 400  * portion, the number of word parameters and the data portion of the message.
 401  */
 402 unsigned int
 403 smb2_calc_size(void *buf, struct TCP_Server_Info *srvr)
 404 {
 405         struct smb2_sync_pdu *pdu = (struct smb2_sync_pdu *)buf;
 406         struct smb2_sync_hdr *shdr = &pdu->sync_hdr;
 407         int offset; /* the offset from the beginning of SMB to data area */
 408         int data_length; /* the length of the variable length data area */
 409         /* Structure Size has already been checked to make sure it is 64 */
 410         int len = le16_to_cpu(shdr->StructureSize);
 411
 412         /*
 413          * StructureSize2, ie length of fixed parameter area has already
 414          * been checked to make sure it is the correct length.
 415          */
 416         len += le16_to_cpu(pdu->StructureSize2);
 417
 418         if (has_smb2_data_area[le16_to_cpu(shdr->Command)] == false)
 419                 goto calc_size_exit;
 420
 421         smb2_get_data_area_len(&offset, &data_length, shdr);
 422         cifs_dbg(FYI, "SMB2 data length %d offset %d\n", data_length, offset);
 423
 424         if (data_length > 0) {
 425                 /*
 426                  * Check to make sure that data area begins after fixed area,
 427                  * Note that last byte of the fixed area is part of data area
 428                  * for some commands, typically those with odd StructureSize,
 429                  * so we must add one to the calculation.
 430                  */
 431                 if (offset + 1 < len) {
 432                         cifs_dbg(VFS, "data area offset %d overlaps SMB2 header %d\n",
 433                                  offset + 1, len);
 434                         data_length = 0;
 435                 } else {
 436                         len = offset + data_length;
 437                 }
 438         }
 439 calc_size_exit:
 440         cifs_dbg(FYI, "SMB2 len %d\n", len);
 441         return len;
 442 }
 443
 444 /* Note: caller must free return buffer */
 445 __le16 *
 446 cifs_convert_path_to_utf16(const char *from, struct cifs_sb_info *cifs_sb)
 447 {
 448         int len;
 449         const char *start_of_path;
 450         __le16 *to;
 451         int map_type;
 452
 453         if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SFM_CHR)
 454                 map_type = SFM_MAP_UNI_RSVD;
 455         else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR)
 456                 map_type = SFU_MAP_UNI_RSVD;
 457         else
 458                 map_type = NO_MAP_UNI_RSVD;
 459
 460         /* Windows doesn't allow paths beginning with \ */
 461         if (from[0] == '\\')
 462                 start_of_path = from + 1;
 463
 464         /* SMB311 POSIX extensions paths do not include leading slash */
 465         else if (cifs_sb_master_tlink(cifs_sb) &&
 466                  cifs_sb_master_tcon(cifs_sb)->posix_extensions &&
 467                  (from[0] == '/')) {
 468                 start_of_path = from + 1;
 469         } else
 470                 start_of_path = from;
 471
 472         to = cifs_strndup_to_utf16(start_of_path, PATH_MAX, &len,
 473                                    cifs_sb->local_nls, map_type);
 474         return to;
 475 }
 476
 477 __le32
 478 smb2_get_lease_state(struct cifsInodeInfo *cinode)
 479 {
 480         __le32 lease = 0;
 481
 482         if (CIFS_CACHE_WRITE(cinode))
 483                 lease |= SMB2_LEASE_WRITE_CACHING;
 484         if (CIFS_CACHE_HANDLE(cinode))
 485                 lease |= SMB2_LEASE_HANDLE_CACHING;
 486         if (CIFS_CACHE_READ(cinode))
 487                 lease |= SMB2_LEASE_READ_CACHING;
 488         return lease;
 489 }
 490
 491 struct smb2_lease_break_work {
 492         struct work_struct lease_break;
 493         struct tcon_link *tlink;
 494         __u8 lease_key[16];
 495         __le32 lease_state;
 496 };
 497
 498 static void
 499 cifs_ses_oplock_break(struct work_struct *work)
 500 {
 501         struct smb2_lease_break_work *lw = container_of(work,
 502                                 struct smb2_lease_break_work, lease_break);
 503         int rc = 0;
 504
 505         rc = SMB2_lease_break(0, tlink_tcon(lw->tlink), lw->lease_key,
 506                               lw->lease_state);
 507
 508         cifs_dbg(FYI, "Lease release rc %d\n", rc);
 509         cifs_put_tlink(lw->tlink);
 510         kfree(lw);
 511 }
 512
 513 static void
 514 smb2_queue_pending_open_break(struct tcon_link *tlink, __u8 *lease_key,
 515                               __le32 new_lease_state)
 516 {
 517         struct smb2_lease_break_work *lw;
 518
 519         lw = kmalloc(sizeof(struct smb2_lease_break_work), GFP_KERNEL);
 520         if (!lw) {
 521                 cifs_put_tlink(tlink);
 522                 return;
 523         }
 524
 525         INIT_WORK(&lw->lease_break, cifs_ses_oplock_break);
 526         lw->tlink = tlink;
 527         lw->lease_state = new_lease_state;
 528         memcpy(lw->lease_key, lease_key, SMB2_LEASE_KEY_SIZE);
 529         queue_work(cifsiod_wq, &lw->lease_break);
 530 }
 531
 532 static bool
 533 smb2_tcon_has_lease(struct cifs_tcon *tcon, struct smb2_lease_break *rsp)
 534 {
 535         __u8 lease_state;
 536         struct cifsFileInfo *cfile;
 537         struct cifsInodeInfo *cinode;
 538         int ack_req = le32_to_cpu(rsp->Flags &
 539                                   SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
 540
 541         lease_state = le32_to_cpu(rsp->NewLeaseState);
 542
 543         list_for_each_entry(cfile, &tcon->openFileList, tlist) {
 544                 cinode = CIFS_I(d_inode(cfile->dentry));
 545
 546                 if (memcmp(cinode->lease_key, rsp->LeaseKey,
 547                                                         SMB2_LEASE_KEY_SIZE))
 548                         continue;
 549
 550                 cifs_dbg(FYI, "found in the open list\n");
 551                 cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
 552                          lease_state);
 553
 554                 if (ack_req)
 555                         cfile->oplock_break_cancelled = false;
 556                 else
 557                         cfile->oplock_break_cancelled = true;
 558
 559                 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK, &cinode->flags);
 560
 561                 cfile->oplock_epoch = le16_to_cpu(rsp->Epoch);
 562                 cfile->oplock_level = lease_state;
 563
 564                 cifs_queue_oplock_break(cfile);
 565                 return true;
 566         }
 567
 568         return false;
 569 }
 570
 571 static struct cifs_pending_open *
 572 smb2_tcon_find_pending_open_lease(struct cifs_tcon *tcon,
 573                                   struct smb2_lease_break *rsp)
 574 {
 575         __u8 lease_state = le32_to_cpu(rsp->NewLeaseState);
 576         int ack_req = le32_to_cpu(rsp->Flags &
 577                                   SMB2_NOTIFY_BREAK_LEASE_FLAG_ACK_REQUIRED);
 578         struct cifs_pending_open *open;
 579         struct cifs_pending_open *found = NULL;
 580
 581         list_for_each_entry(open, &tcon->pending_opens, olist) {
 582                 if (memcmp(open->lease_key, rsp->LeaseKey,
 583                            SMB2_LEASE_KEY_SIZE))
 584                         continue;
 585
 586                 if (!found && ack_req) {
 587                         found = open;
 588                 }
 589
 590                 cifs_dbg(FYI, "found in the pending open list\n");
 591                 cifs_dbg(FYI, "lease key match, lease break 0x%x\n",
 592                          lease_state);
 593
 594                 open->oplock = lease_state;
 595         }
 596
 597         return found;
 598 }
 599
 600 static bool
 601 smb2_is_valid_lease_break(char *buffer)
 602 {
 603         struct smb2_lease_break *rsp = (struct smb2_lease_break *)buffer;
 604         struct TCP_Server_Info *server;
 605         struct cifs_ses *ses;
 606         struct cifs_tcon *tcon;
 607         struct cifs_pending_open *open;
 608
 609         cifs_dbg(FYI, "Checking for lease break\n");
 610
 611         /* look up tcon based on tid & uid */
 612         spin_lock(&cifs_tcp_ses_lock);
 613         list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
 614                 list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 615                         list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 616                                 spin_lock(&tcon->open_file_lock);
 617                                 cifs_stats_inc(
 618                                     &tcon->stats.cifs_stats.num_oplock_brks);
 619                                 if (smb2_tcon_has_lease(tcon, rsp)) {
 620                                         spin_unlock(&tcon->open_file_lock);
 621                                         spin_unlock(&cifs_tcp_ses_lock);
 622                                         return true;
 623                                 }
 624                                 open = smb2_tcon_find_pending_open_lease(tcon,
 625                                                                          rsp);
 626                                 if (open) {
 627                                         __u8 lease_key[SMB2_LEASE_KEY_SIZE];
 628                                         struct tcon_link *tlink;
 629
 630                                         tlink = cifs_get_tlink(open->tlink);
 631                                         memcpy(lease_key, open->lease_key,
 632                                                SMB2_LEASE_KEY_SIZE);
 633                                         spin_unlock(&tcon->open_file_lock);
 634                                         spin_unlock(&cifs_tcp_ses_lock);
 635                                         smb2_queue_pending_open_break(tlink,
 636                                                                       lease_key,
 637                                                                       rsp->NewLeaseState);
 638                                         return true;
 639                                 }
 640                                 spin_unlock(&tcon->open_file_lock);
 641
 642                                 if (tcon->crfid.is_valid &&
 643                                     !memcmp(rsp->LeaseKey,
 644                                             tcon->crfid.fid->lease_key,
 645                                             SMB2_LEASE_KEY_SIZE)) {
 646                                         tcon->crfid.time = 0;
 647                                         INIT_WORK(&tcon->crfid.lease_break,
 648                                                   smb2_cached_lease_break);
 649                                         queue_work(cifsiod_wq,
 650                                                    &tcon->crfid.lease_break);
 651                                         spin_unlock(&cifs_tcp_ses_lock);
 652                                         return true;
 653                                 }
 654                         }
 655                 }
 656         }
 657         spin_unlock(&cifs_tcp_ses_lock);
 658         cifs_dbg(FYI, "Can not process lease break - no lease matched\n");
 659         return false;
 660 }
 661
 662 bool
 663 smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 664 {
 665         struct smb2_oplock_break *rsp = (struct smb2_oplock_break *)buffer;
 666         struct cifs_ses *ses;
 667         struct cifs_tcon *tcon;
 668         struct cifsInodeInfo *cinode;
 669         struct cifsFileInfo *cfile;
 670
 671         cifs_dbg(FYI, "Checking for oplock break\n");
 672
 673         if (rsp->sync_hdr.Command != SMB2_OPLOCK_BREAK)
 674                 return false;
 675
 676         if (rsp->StructureSize !=
 677                                 smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 678                 if (le16_to_cpu(rsp->StructureSize) == 44)
 679                         return smb2_is_valid_lease_break(buffer);
 680                 else
 681                         return false;
 682         }
 683
 684         cifs_dbg(FYI, "oplock level 0x%x\n", rsp->OplockLevel);
 685
 686         /* look up tcon based on tid & uid */
 687         spin_lock(&cifs_tcp_ses_lock);
 688         list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
 689                 list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
 690
 691                         spin_lock(&tcon->open_file_lock);
 692                         list_for_each_entry(cfile, &tcon->openFileList, tlist) {
 693                                 if (rsp->PersistentFid !=
 694                                     cfile->fid.persistent_fid ||
 695                                     rsp->VolatileFid !=
 696                                     cfile->fid.volatile_fid)
 697                                         continue;
 698
 699                                 cifs_dbg(FYI, "file id match, oplock break\n");
 700                                 cifs_stats_inc(
 701                                     &tcon->stats.cifs_stats.num_oplock_brks);
 702                                 cinode = CIFS_I(d_inode(cfile->dentry));
 703                                 spin_lock(&cfile->file_info_lock);
 704                                 if (!CIFS_CACHE_WRITE(cinode) &&
 705                                     rsp->OplockLevel == SMB2_OPLOCK_LEVEL_NONE)
 706                                         cfile->oplock_break_cancelled = true;
 707                                 else
 708                                         cfile->oplock_break_cancelled = false;
 709
 710                                 set_bit(CIFS_INODE_PENDING_OPLOCK_BREAK,
 711                                         &cinode->flags);
 712
 713                                 cfile->oplock_epoch = 0;
 714                                 cfile->oplock_level = rsp->OplockLevel;
 715
 716                                 spin_unlock(&cfile->file_info_lock);
 717
 718                                 cifs_queue_oplock_break(cfile);
 719
 720                                 spin_unlock(&tcon->open_file_lock);
 721                                 spin_unlock(&cifs_tcp_ses_lock);
 722                                 return true;
 723                         }
 724                         spin_unlock(&tcon->open_file_lock);
 725                 }
 726         }
 727         spin_unlock(&cifs_tcp_ses_lock);
 728         cifs_dbg(FYI, "No file id matched, oplock break ignored\n");
 729         return true;
 730 }
 731
 732 void
 733 smb2_cancelled_close_fid(struct work_struct *work)
 734 {
 735         struct close_cancelled_open *cancelled = container_of(work,
 736                                         struct close_cancelled_open, work);
 737         struct cifs_tcon *tcon = cancelled->tcon;
 738         int rc;
 739
 740         if (cancelled->mid)
 741                 cifs_tcon_dbg(VFS, "Close unmatched open for MID:%llu\n",
 742                               cancelled->mid);
 743         else
 744                 cifs_tcon_dbg(VFS, "Close interrupted close\n");
 745
 746         rc = SMB2_close(0, tcon, cancelled->fid.persistent_fid,
 747                         cancelled->fid.volatile_fid);
 748         if (rc)
 749                 cifs_tcon_dbg(VFS, "Close cancelled mid failed rc:%d\n", rc);
 750
 751         cifs_put_tcon(tcon);
 752         kfree(cancelled);
 753 }
 754
 755 /*
 756  * Caller should already has an extra reference to @tcon
 757  * This function is used to queue work to close a handle to prevent leaks
 758  * on the server.
 759  * We handle two cases. If an open was interrupted after we sent the
 760  * SMB2_CREATE to the server but before we processed the reply, and second
 761  * if a close was interrupted before we sent the SMB2_CLOSE to the server.
 762  */
 763 static int
 764 __smb2_handle_cancelled_cmd(struct cifs_tcon *tcon, __u16 cmd, __u64 mid,
 765                             __u64 persistent_fid, __u64 volatile_fid)
 766 {
 767         struct close_cancelled_open *cancelled;
 768
 769         cancelled = kzalloc(sizeof(*cancelled), GFP_ATOMIC);
 770         if (!cancelled)
 771                 return -ENOMEM;
 772
 773         cancelled->fid.persistent_fid = persistent_fid;
 774         cancelled->fid.volatile_fid = volatile_fid;
 775         cancelled->tcon = tcon;
 776         cancelled->cmd = cmd;
 777         cancelled->mid = mid;
 778         INIT_WORK(&cancelled->work, smb2_cancelled_close_fid);
 779         WARN_ON(queue_work(cifsiod_wq, &cancelled->work) == false);
 780
 781         return 0;
 782 }
 783
 784 int
 785 smb2_handle_cancelled_close(struct cifs_tcon *tcon, __u64 persistent_fid,
 786                             __u64 volatile_fid)
 787 {
 788         int rc;
 789
 790         cifs_dbg(FYI, "%s: tc_count=%d\n", __func__, tcon->tc_count);
 791         spin_lock(&cifs_tcp_ses_lock);
 792         if (tcon->tc_count <= 0) {
 793                 struct TCP_Server_Info *server = NULL;
 794
 795                 WARN_ONCE(tcon->tc_count < 0, "tcon refcount is negative");
 796                 spin_unlock(&cifs_tcp_ses_lock);
 797
 798                 if (tcon->ses)
 799                         server = tcon->ses->server;
 800
 801                 cifs_server_dbg(FYI, "tid=%u: tcon is closing, skipping async close retry of fid %llu %llu\n",
 802                                 tcon->tid, persistent_fid, volatile_fid);
 803
 804                 return 0;
 805         }
 806         tcon->tc_count++;
 807         spin_unlock(&cifs_tcp_ses_lock);
 808
 809         rc = __smb2_handle_cancelled_cmd(tcon, SMB2_CLOSE_HE, 0,
 810                                          persistent_fid, volatile_fid);
 811         if (rc)
 812                 cifs_put_tcon(tcon);
 813
 814         return rc;
 815 }
 816
 817 int
 818 smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *server)
 819 {
 820         struct smb2_sync_hdr *sync_hdr = mid->resp_buf;
 821         struct smb2_create_rsp *rsp = mid->resp_buf;
 822         struct cifs_tcon *tcon;
 823         int rc;
 824
 825         if ((mid->optype & CIFS_CP_CREATE_CLOSE_OP) || sync_hdr->Command != SMB2_CREATE ||
 826             sync_hdr->Status != STATUS_SUCCESS)
 827                 return 0;
 828
 829         tcon = smb2_find_smb_tcon(server, sync_hdr->SessionId,
 830                                   sync_hdr->TreeId);
 831         if (!tcon)
 832                 return -ENOENT;
 833
 834         rc = __smb2_handle_cancelled_cmd(tcon,
 835                                          le16_to_cpu(sync_hdr->Command),
 836                                          le64_to_cpu(sync_hdr->MessageId),
 837                                          rsp->PersistentFileId,
 838                                          rsp->VolatileFileId);
 839         if (rc)
 840                 cifs_put_tcon(tcon);
 841
 842         return rc;
 843 }
 844
 845 /**
 846  * smb311_update_preauth_hash - update @ses hash with the packet data in @iov
 847  *
 848  * Assumes @iov does not contain the rfc1002 length and iov[0] has the
 849  * SMB2 header.
 850  *
 851  * @ses:        server session structure
 852  * @iov:        array containing the SMB request we will send to the server
 853  * @nvec:       number of array entries for the iov
 854  */
 855 int
 856 smb311_update_preauth_hash(struct cifs_ses *ses, struct kvec *iov, int nvec)
 857 {
 858         int i, rc;
 859         struct sdesc *d;
 860         struct smb2_sync_hdr *hdr;
 861         struct TCP_Server_Info *server = cifs_ses_server(ses);
 862
 863         hdr = (struct smb2_sync_hdr *)iov[0].iov_base;
 864         /* neg prot are always taken */
 865         if (hdr->Command == SMB2_NEGOTIATE)
 866                 goto ok;
 867
 868         /*
 869          * If we process a command which wasn't a negprot it means the
 870          * neg prot was already done, so the server dialect was set
 871          * and we can test it. Preauth requires 3.1.1 for now.
 872          */
 873         if (server->dialect != SMB311_PROT_ID)
 874                 return 0;
 875
 876         if (hdr->Command != SMB2_SESSION_SETUP)
 877                 return 0;
 878
 879         /* skip last sess setup response */
 880         if ((hdr->Flags & SMB2_FLAGS_SERVER_TO_REDIR)
 881             && (hdr->Status == NT_STATUS_OK
 882                 || (hdr->Status !=
 883                     cpu_to_le32(NT_STATUS_MORE_PROCESSING_REQUIRED))))
 884                 return 0;
 885
 886 ok:
 887         rc = smb311_crypto_shash_allocate(server);
 888         if (rc)
 889                 return rc;
 890
 891         d = server->secmech.sdescsha512;
 892         rc = crypto_shash_init(&d->shash);
 893         if (rc) {
 894                 cifs_dbg(VFS, "%s: Could not init sha512 shash\n", __func__);
 895                 return rc;
 896         }
 897
 898         rc = crypto_shash_update(&d->shash, ses->preauth_sha_hash,
 899                                  SMB2_PREAUTH_HASH_SIZE);
 900         if (rc) {
 901                 cifs_dbg(VFS, "%s: Could not update sha512 shash\n", __func__);
 902                 return rc;
 903         }
 904
 905         for (i = 0; i < nvec; i++) {
 906                 rc = crypto_shash_update(&d->shash,
 907                                          iov[i].iov_base, iov[i].iov_len);
 908                 if (rc) {
 909                         cifs_dbg(VFS, "%s: Could not update sha512 shash\n",
 910                                  __func__);
 911                         return rc;
 912                 }
 913         }
 914
 915         rc = crypto_shash_final(&d->shash, ses->preauth_sha_hash);
 916         if (rc) {
 917                 cifs_dbg(VFS, "%s: Could not finalize sha512 shash\n",
 918                          __func__);
 919                 return rc;
 920         }
 921
 922         return 0;
 923 }