fs/cifs/smb2misc.c

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