source3/modules/vfs_streams_xattr.c

   1 /*
   2  * Store streams in xattrs
   3  *
   4  * Copyright (C) Volker Lendecke, 2008
   5  *
   6  * Partly based on James Peach's Darwin module, which is
   7  *
   8  * Copyright (C) James Peach 2006-2007
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 3 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24 #include "includes.h"
  25 #include "smbd/smbd.h"
  26 #include "system/filesys.h"
  27 #include "../lib/crypto/md5.h"
  28
  29 #undef DBGC_CLASS
  30 #define DBGC_CLASS DBGC_VFS
  31
  32 struct stream_io {
  33         char *base;
  34         char *xattr_name;
  35         void *fsp_name_ptr;
  36         files_struct *fsp;
  37         vfs_handle_struct *handle;
  38 };
  39
  40 static SMB_INO_T stream_inode(const SMB_STRUCT_STAT *sbuf, const char *sname)
  41 {
  42         MD5_CTX ctx;
  43         unsigned char hash[16];
  44         SMB_INO_T result;
  45         char *upper_sname;
  46
  47         DEBUG(10, ("stream_inode called for %lu/%lu [%s]\n",
  48                    (unsigned long)sbuf->st_ex_dev,
  49                    (unsigned long)sbuf->st_ex_ino, sname));
  50
  51         upper_sname = talloc_strdup_upper(talloc_tos(), sname);
  52         SMB_ASSERT(upper_sname != NULL);
  53
  54         MD5Init(&ctx);
  55         MD5Update(&ctx, (const unsigned char *)&(sbuf->st_ex_dev),
  56                   sizeof(sbuf->st_ex_dev));
  57         MD5Update(&ctx, (const unsigned char *)&(sbuf->st_ex_ino),
  58                   sizeof(sbuf->st_ex_ino));
  59         MD5Update(&ctx, (unsigned char *)upper_sname,
  60                   talloc_get_size(upper_sname)-1);
  61         MD5Final(hash, &ctx);
  62
  63         TALLOC_FREE(upper_sname);
  64
  65         /* Hopefully all the variation is in the lower 4 (or 8) bytes! */
  66         memcpy(&result, hash, sizeof(result));
  67
  68         DEBUG(10, ("stream_inode returns %lu\n", (unsigned long)result));
  69
  70         return result;
  71 }
  72
  73 static ssize_t get_xattr_size(connection_struct *conn,
  74                                 files_struct *fsp,
  75                                 const char *fname,
  76                                 const char *xattr_name)
  77 {
  78         NTSTATUS status;
  79         struct ea_struct ea;
  80         ssize_t result;
  81
  82         status = get_ea_value(talloc_tos(), conn, fsp, fname,
  83                               xattr_name, &ea);
  84
  85         if (!NT_STATUS_IS_OK(status)) {
  86                 return -1;
  87         }
  88
  89         result = ea.value.length-1;
  90         TALLOC_FREE(ea.value.data);
  91         return result;
  92 }
  93
  94 /**
  95  * Given a stream name, populate xattr_name with the xattr name to use for
  96  * accessing the stream.
  97  */
  98 static NTSTATUS streams_xattr_get_name(TALLOC_CTX *ctx,
  99                                        const char *stream_name,
 100                                        char **xattr_name)
 101 {
 102         char *stype;
 103
 104         stype = strchr_m(stream_name + 1, ':');
 105
 106         *xattr_name = talloc_asprintf(ctx, "%s%s",
 107                                       SAMBA_XATTR_DOSSTREAM_PREFIX,
 108                                       stream_name + 1);
 109         if (*xattr_name == NULL) {
 110                 return NT_STATUS_NO_MEMORY;
 111         }
 112
 113         if (stype == NULL) {
 114                 /* Append an explicit stream type if one wasn't specified. */
 115                 *xattr_name = talloc_asprintf(ctx, "%s:$DATA",
 116                                                *xattr_name);
 117                 if (*xattr_name == NULL) {
 118                         return NT_STATUS_NO_MEMORY;
 119                 }
 120         } else {
 121                 /* Normalize the stream type to upercase. */
 122                 if (!strupper_m(strrchr_m(*xattr_name, ':') + 1)) {
 123                         return NT_STATUS_INVALID_PARAMETER;
 124                 }
 125         }
 126
 127         DEBUG(10, ("xattr_name: %s, stream_name: %s\n", *xattr_name,
 128                    stream_name));
 129
 130         return NT_STATUS_OK;
 131 }
 132
 133 static bool streams_xattr_recheck(struct stream_io *sio)
 134 {
 135         NTSTATUS status;
 136         char *xattr_name = NULL;
 137
 138         if (sio->fsp->fsp_name == sio->fsp_name_ptr) {
 139                 return true;
 140         }
 141
 142         if (sio->fsp->fsp_name->stream_name == NULL) {
 143                 /* how can this happen */
 144                 errno = EINVAL;
 145                 return false;
 146         }
 147
 148         status = streams_xattr_get_name(talloc_tos(),
 149                                         sio->fsp->fsp_name->stream_name,
 150                                         &xattr_name);
 151         if (!NT_STATUS_IS_OK(status)) {
 152                 return false;
 153         }
 154
 155         TALLOC_FREE(sio->xattr_name);
 156         TALLOC_FREE(sio->base);
 157         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 158                                         xattr_name);
 159         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 160                                   sio->fsp->fsp_name->base_name);
 161         sio->fsp_name_ptr = sio->fsp->fsp_name;
 162
 163         TALLOC_FREE(xattr_name);
 164
 165         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 166                 return false;
 167         }
 168
 169         return true;
 170 }
 171
 172 /**
 173  * Helper to stat/lstat the base file of an smb_fname.
 174  */
 175 static int streams_xattr_stat_base(vfs_handle_struct *handle,
 176                                    struct smb_filename *smb_fname,
 177                                    bool follow_links)
 178 {
 179         char *tmp_stream_name;
 180         int result;
 181
 182         tmp_stream_name = smb_fname->stream_name;
 183         smb_fname->stream_name = NULL;
 184         if (follow_links) {
 185                 result = SMB_VFS_NEXT_STAT(handle, smb_fname);
 186         } else {
 187                 result = SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 188         }
 189         smb_fname->stream_name = tmp_stream_name;
 190         return result;
 191 }
 192
 193 static int streams_xattr_fstat(vfs_handle_struct *handle, files_struct *fsp,
 194                                SMB_STRUCT_STAT *sbuf)
 195 {
 196         struct smb_filename *smb_fname_base = NULL;
 197         int ret = -1;
 198         struct stream_io *io = (struct stream_io *)
 199                 VFS_FETCH_FSP_EXTENSION(handle, fsp);
 200
 201         DEBUG(10, ("streams_xattr_fstat called for %d\n", fsp->fh->fd));
 202
 203         if (io == NULL || fsp->base_fsp == NULL) {
 204                 return SMB_VFS_NEXT_FSTAT(handle, fsp, sbuf);
 205         }
 206
 207         if (!streams_xattr_recheck(io)) {
 208                 return -1;
 209         }
 210
 211         /* Create an smb_filename with stream_name == NULL. */
 212         smb_fname_base = synthetic_smb_fname(talloc_tos(), io->base,
 213                                              NULL, NULL);
 214         if (smb_fname_base == NULL) {
 215                 errno = ENOMEM;
 216                 return -1;
 217         }
 218
 219         if (lp_posix_pathnames()) {
 220                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname_base);
 221         } else {
 222                 ret = SMB_VFS_STAT(handle->conn, smb_fname_base);
 223         }
 224         *sbuf = smb_fname_base->st;
 225         TALLOC_FREE(smb_fname_base);
 226
 227         if (ret == -1) {
 228                 return -1;
 229         }
 230
 231         sbuf->st_ex_size = get_xattr_size(handle->conn, fsp->base_fsp,
 232                                         io->base, io->xattr_name);
 233         if (sbuf->st_ex_size == -1) {
 234                 return -1;
 235         }
 236
 237         DEBUG(10, ("sbuf->st_ex_size = %d\n", (int)sbuf->st_ex_size));
 238
 239         sbuf->st_ex_ino = stream_inode(sbuf, io->xattr_name);
 240         sbuf->st_ex_mode &= ~S_IFMT;
 241         sbuf->st_ex_mode |= S_IFREG;
 242         sbuf->st_ex_blocks = sbuf->st_ex_size / STAT_ST_BLOCKSIZE + 1;
 243
 244         return 0;
 245 }
 246
 247 static int streams_xattr_stat(vfs_handle_struct *handle,
 248                               struct smb_filename *smb_fname)
 249 {
 250         NTSTATUS status;
 251         int result = -1;
 252         char *xattr_name = NULL;
 253
 254         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 255                 return SMB_VFS_NEXT_STAT(handle, smb_fname);
 256         }
 257
 258         /* Note if lp_posix_paths() is true, we can never
 259          * get here as is_ntfs_stream_smb_fname() is
 260          * always false. So we never need worry about
 261          * not following links here. */
 262
 263         /* If the default stream is requested, just stat the base file. */
 264         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 265                 return streams_xattr_stat_base(handle, smb_fname, true);
 266         }
 267
 268         /* Populate the stat struct with info from the base file. */
 269         if (streams_xattr_stat_base(handle, smb_fname, true) == -1) {
 270                 return -1;
 271         }
 272
 273         /* Derive the xattr name to lookup. */
 274         status = streams_xattr_get_name(talloc_tos(), smb_fname->stream_name,
 275                                         &xattr_name);
 276         if (!NT_STATUS_IS_OK(status)) {
 277                 errno = map_errno_from_nt_status(status);
 278                 return -1;
 279         }
 280
 281         /* Augment the base file's stat information before returning. */
 282         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 283                                                   smb_fname->base_name,
 284                                                   xattr_name);
 285         if (smb_fname->st.st_ex_size == -1) {
 286                 errno = ENOENT;
 287                 result = -1;
 288                 goto fail;
 289         }
 290
 291         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 292         smb_fname->st.st_ex_mode &= ~S_IFMT;
 293         smb_fname->st.st_ex_mode |= S_IFREG;
 294         smb_fname->st.st_ex_blocks =
 295             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 296
 297         result = 0;
 298  fail:
 299         TALLOC_FREE(xattr_name);
 300         return result;
 301 }
 302
 303 static int streams_xattr_lstat(vfs_handle_struct *handle,
 304                                struct smb_filename *smb_fname)
 305 {
 306         NTSTATUS status;
 307         int result = -1;
 308         char *xattr_name = NULL;
 309
 310         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 311                 return SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 312         }
 313
 314         /* If the default stream is requested, just stat the base file. */
 315         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 316                 return streams_xattr_stat_base(handle, smb_fname, false);
 317         }
 318
 319         /* Populate the stat struct with info from the base file. */
 320         if (streams_xattr_stat_base(handle, smb_fname, false) == -1) {
 321                 return -1;
 322         }
 323
 324         /* Derive the xattr name to lookup. */
 325         status = streams_xattr_get_name(talloc_tos(), smb_fname->stream_name,
 326                                         &xattr_name);
 327         if (!NT_STATUS_IS_OK(status)) {
 328                 errno = map_errno_from_nt_status(status);
 329                 return -1;
 330         }
 331
 332         /* Augment the base file's stat information before returning. */
 333         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 334                                                   smb_fname->base_name,
 335                                                   xattr_name);
 336         if (smb_fname->st.st_ex_size == -1) {
 337                 errno = ENOENT;
 338                 result = -1;
 339                 goto fail;
 340         }
 341
 342         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 343         smb_fname->st.st_ex_mode &= ~S_IFMT;
 344         smb_fname->st.st_ex_mode |= S_IFREG;
 345         smb_fname->st.st_ex_blocks =
 346             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 347
 348         result = 0;
 349
 350  fail:
 351         TALLOC_FREE(xattr_name);
 352         return result;
 353 }
 354
 355 static int streams_xattr_open(vfs_handle_struct *handle,
 356                               struct smb_filename *smb_fname,
 357                               files_struct *fsp, int flags, mode_t mode)
 358 {
 359         NTSTATUS status;
 360         struct smb_filename *smb_fname_base = NULL;
 361         struct stream_io *sio;
 362         struct ea_struct ea;
 363         char *xattr_name = NULL;
 364         int baseflags;
 365         int hostfd = -1;
 366
 367         DEBUG(10, ("streams_xattr_open called for %s with flags 0x%x\n",
 368                    smb_fname_str_dbg(smb_fname), flags));
 369
 370         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 371                 return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 372         }
 373
 374         /* If the default stream is requested, just open the base file. */
 375         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 376                 char *tmp_stream_name;
 377                 int ret;
 378
 379                 tmp_stream_name = smb_fname->stream_name;
 380                 smb_fname->stream_name = NULL;
 381
 382                 ret = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 383
 384                 smb_fname->stream_name = tmp_stream_name;
 385
 386                 return ret;
 387         }
 388
 389         status = streams_xattr_get_name(talloc_tos(), smb_fname->stream_name,
 390                                         &xattr_name);
 391         if (!NT_STATUS_IS_OK(status)) {
 392                 errno = map_errno_from_nt_status(status);
 393                 goto fail;
 394         }
 395
 396         /* Create an smb_filename with stream_name == NULL. */
 397         smb_fname_base = synthetic_smb_fname(
 398                 talloc_tos(), smb_fname->base_name, NULL, NULL);
 399         if (smb_fname_base == NULL) {
 400                 errno = ENOMEM;
 401                 goto fail;
 402         }
 403
 404         /*
 405          * We use baseflags to turn off nasty side-effects when opening the
 406          * underlying file.
 407          */
 408         baseflags = flags;
 409         baseflags &= ~O_TRUNC;
 410         baseflags &= ~O_EXCL;
 411         baseflags &= ~O_CREAT;
 412
 413         hostfd = SMB_VFS_OPEN(handle->conn, smb_fname_base, fsp,
 414                               baseflags, mode);
 415
 416         TALLOC_FREE(smb_fname_base);
 417
 418         /* It is legit to open a stream on a directory, but the base
 419          * fd has to be read-only.
 420          */
 421         if ((hostfd == -1) && (errno == EISDIR)) {
 422                 baseflags &= ~O_ACCMODE;
 423                 baseflags |= O_RDONLY;
 424                 hostfd = SMB_VFS_OPEN(handle->conn, smb_fname, fsp, baseflags,
 425                                       mode);
 426         }
 427
 428         if (hostfd == -1) {
 429                 goto fail;
 430         }
 431
 432         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 433                               smb_fname->base_name, xattr_name, &ea);
 434
 435         DEBUG(10, ("get_ea_value returned %s\n", nt_errstr(status)));
 436
 437         if (!NT_STATUS_IS_OK(status)
 438             && !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 439                 /*
 440                  * The base file is not there. This is an error even if we got
 441                  * O_CREAT, the higher levels should have created the base
 442                  * file for us.
 443                  */
 444                 DEBUG(10, ("streams_xattr_open: base file %s not around, "
 445                            "returning ENOENT\n", smb_fname->base_name));
 446                 errno = ENOENT;
 447                 goto fail;
 448         }
 449
 450         if ((!NT_STATUS_IS_OK(status) && (flags & O_CREAT)) ||
 451             (flags & O_TRUNC)) {
 452                 /*
 453                  * The attribute does not exist or needs to be truncated
 454                  */
 455
 456                 /*
 457                  * Darn, xattrs need at least 1 byte
 458                  */
 459                 char null = '\0';
 460
 461                 DEBUG(10, ("creating or truncating attribute %s on file %s\n",
 462                            xattr_name, smb_fname->base_name));
 463
 464                 if (fsp->base_fsp->fh->fd != -1) {
 465                         if (SMB_VFS_FSETXATTR(
 466                                         fsp->base_fsp, xattr_name,
 467                                         &null, sizeof(null),
 468                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 469                                 goto fail;
 470                         }
 471                 } else {
 472                         if (SMB_VFS_SETXATTR(
 473                                         handle->conn, smb_fname->base_name,
 474                                         xattr_name, &null, sizeof(null),
 475                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 476                                 goto fail;
 477                         }
 478                 }
 479         }
 480
 481         sio = (struct stream_io *)VFS_ADD_FSP_EXTENSION(handle, fsp,
 482                                                         struct stream_io,
 483                                                         NULL);
 484         if (sio == NULL) {
 485                 errno = ENOMEM;
 486                 goto fail;
 487         }
 488
 489         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 490                                         xattr_name);
 491         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 492                                   smb_fname->base_name);
 493         sio->fsp_name_ptr = fsp->fsp_name;
 494         sio->handle = handle;
 495         sio->fsp = fsp;
 496
 497         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 498                 errno = ENOMEM;
 499                 goto fail;
 500         }
 501
 502         return hostfd;
 503
 504  fail:
 505         if (hostfd >= 0) {
 506                 /*
 507                  * BUGBUGBUG -- we would need to call fd_close_posix here, but
 508                  * we don't have a full fsp yet
 509                  */
 510                 fsp->fh->fd = hostfd;
 511                 SMB_VFS_CLOSE(fsp);
 512         }
 513
 514         return -1;
 515 }
 516
 517 static int streams_xattr_unlink(vfs_handle_struct *handle,
 518                                 const struct smb_filename *smb_fname)
 519 {
 520         NTSTATUS status;
 521         int ret = -1;
 522         char *xattr_name;
 523
 524         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 525                 return SMB_VFS_NEXT_UNLINK(handle, smb_fname);
 526         }
 527
 528         /* If the default stream is requested, just open the base file. */
 529         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 530                 struct smb_filename *smb_fname_base = NULL;
 531
 532                 smb_fname_base = cp_smb_filename(talloc_tos(), smb_fname);
 533                 if (smb_fname_base == NULL) {
 534                         errno = ENOMEM;
 535                         return -1;
 536                 }
 537
 538                 ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_base);
 539
 540                 TALLOC_FREE(smb_fname_base);
 541                 return ret;
 542         }
 543
 544         status = streams_xattr_get_name(talloc_tos(), smb_fname->stream_name,
 545                                         &xattr_name);
 546         if (!NT_STATUS_IS_OK(status)) {
 547                 errno = map_errno_from_nt_status(status);
 548                 goto fail;
 549         }
 550
 551         ret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname->base_name, xattr_name);
 552
 553         if ((ret == -1) && (errno == ENOATTR)) {
 554                 errno = ENOENT;
 555                 goto fail;
 556         }
 557
 558         ret = 0;
 559
 560  fail:
 561         TALLOC_FREE(xattr_name);
 562         return ret;
 563 }
 564
 565 static int streams_xattr_rename(vfs_handle_struct *handle,
 566                                 const struct smb_filename *smb_fname_src,
 567                                 const struct smb_filename *smb_fname_dst)
 568 {
 569         NTSTATUS status;
 570         int ret = -1;
 571         char *src_xattr_name = NULL;
 572         char *dst_xattr_name = NULL;
 573         bool src_is_stream, dst_is_stream;
 574         ssize_t oret;
 575         ssize_t nret;
 576         struct ea_struct ea;
 577
 578         src_is_stream = is_ntfs_stream_smb_fname(smb_fname_src);
 579         dst_is_stream = is_ntfs_stream_smb_fname(smb_fname_dst);
 580
 581         if (!src_is_stream && !dst_is_stream) {
 582                 return SMB_VFS_NEXT_RENAME(handle, smb_fname_src,
 583                                            smb_fname_dst);
 584         }
 585
 586         /* For now don't allow renames from or to the default stream. */
 587         if (is_ntfs_default_stream_smb_fname(smb_fname_src) ||
 588             is_ntfs_default_stream_smb_fname(smb_fname_dst)) {
 589                 errno = ENOSYS;
 590                 goto done;
 591         }
 592
 593         /* Don't rename if the streams are identical. */
 594         if (strcasecmp_m(smb_fname_src->stream_name,
 595                        smb_fname_dst->stream_name) == 0) {
 596                 goto done;
 597         }
 598
 599         /* Get the xattr names. */
 600         status = streams_xattr_get_name(talloc_tos(),
 601                                         smb_fname_src->stream_name,
 602                                         &src_xattr_name);
 603         if (!NT_STATUS_IS_OK(status)) {
 604                 errno = map_errno_from_nt_status(status);
 605                 goto fail;
 606         }
 607         status = streams_xattr_get_name(talloc_tos(),
 608                                         smb_fname_dst->stream_name,
 609                                         &dst_xattr_name);
 610         if (!NT_STATUS_IS_OK(status)) {
 611                 errno = map_errno_from_nt_status(status);
 612                 goto fail;
 613         }
 614
 615         /* read the old stream */
 616         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 617                               smb_fname_src->base_name, src_xattr_name, &ea);
 618         if (!NT_STATUS_IS_OK(status)) {
 619                 errno = ENOENT;
 620                 goto fail;
 621         }
 622
 623         /* (over)write the new stream */
 624         nret = SMB_VFS_SETXATTR(handle->conn, smb_fname_src->base_name,
 625                                 dst_xattr_name, ea.value.data, ea.value.length,
 626                                 0);
 627         if (nret < 0) {
 628                 if (errno == ENOATTR) {
 629                         errno = ENOENT;
 630                 }
 631                 goto fail;
 632         }
 633
 634         /* remove the old stream */
 635         oret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname_src->base_name,
 636                                    src_xattr_name);
 637         if (oret < 0) {
 638                 if (errno == ENOATTR) {
 639                         errno = ENOENT;
 640                 }
 641                 goto fail;
 642         }
 643
 644  done:
 645         errno = 0;
 646         ret = 0;
 647  fail:
 648         TALLOC_FREE(src_xattr_name);
 649         TALLOC_FREE(dst_xattr_name);
 650         return ret;
 651 }
 652
 653 static NTSTATUS walk_xattr_streams(connection_struct *conn, files_struct *fsp,
 654                                    const char *fname,
 655                                    bool (*fn)(struct ea_struct *ea,
 656                                               void *private_data),
 657                                    void *private_data)
 658 {
 659         NTSTATUS status;
 660         char **names;
 661         size_t i, num_names;
 662         size_t prefix_len = strlen(SAMBA_XATTR_DOSSTREAM_PREFIX);
 663
 664         status = get_ea_names_from_file(talloc_tos(), conn, fsp, fname,
 665                                         &names, &num_names);
 666         if (!NT_STATUS_IS_OK(status)) {
 667                 return status;
 668         }
 669
 670         for (i=0; i<num_names; i++) {
 671                 struct ea_struct ea;
 672
 673                 if (strncmp(names[i], SAMBA_XATTR_DOSSTREAM_PREFIX,
 674                             prefix_len) != 0) {
 675                         continue;
 676                 }
 677
 678                 status = get_ea_value(names, conn, fsp, fname, names[i], &ea);
 679                 if (!NT_STATUS_IS_OK(status)) {
 680                         DEBUG(10, ("Could not get ea %s for file %s: %s\n",
 681                                    names[i], fname, nt_errstr(status)));
 682                         continue;
 683                 }
 684
 685                 ea.name = talloc_asprintf(ea.value.data, ":%s",
 686                                           names[i] + prefix_len);
 687                 if (ea.name == NULL) {
 688                         DEBUG(0, ("talloc failed\n"));
 689                         continue;
 690                 }
 691
 692                 if (!fn(&ea, private_data)) {
 693                         TALLOC_FREE(ea.value.data);
 694                         return NT_STATUS_OK;
 695                 }
 696
 697                 TALLOC_FREE(ea.value.data);
 698         }
 699
 700         TALLOC_FREE(names);
 701         return NT_STATUS_OK;
 702 }
 703
 704 static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
 705                            struct stream_struct **streams,
 706                            const char *name, off_t size,
 707                            off_t alloc_size)
 708 {
 709         struct stream_struct *tmp;
 710
 711         tmp = talloc_realloc(mem_ctx, *streams, struct stream_struct,
 712                                    (*num_streams)+1);
 713         if (tmp == NULL) {
 714                 return false;
 715         }
 716
 717         tmp[*num_streams].name = talloc_strdup(tmp, name);
 718         if (tmp[*num_streams].name == NULL) {
 719                 return false;
 720         }
 721
 722         tmp[*num_streams].size = size;
 723         tmp[*num_streams].alloc_size = alloc_size;
 724
 725         *streams = tmp;
 726         *num_streams += 1;
 727         return true;
 728 }
 729
 730 struct streaminfo_state {
 731         TALLOC_CTX *mem_ctx;
 732         vfs_handle_struct *handle;
 733         unsigned int num_streams;
 734         struct stream_struct *streams;
 735         NTSTATUS status;
 736 };
 737
 738 static bool collect_one_stream(struct ea_struct *ea, void *private_data)
 739 {
 740         struct streaminfo_state *state =
 741                 (struct streaminfo_state *)private_data;
 742
 743         if (!add_one_stream(state->mem_ctx,
 744                             &state->num_streams, &state->streams,
 745                             ea->name, ea->value.length-1,
 746                             smb_roundup(state->handle->conn,
 747                                         ea->value.length-1))) {
 748                 state->status = NT_STATUS_NO_MEMORY;
 749                 return false;
 750         }
 751
 752         return true;
 753 }
 754
 755 static NTSTATUS streams_xattr_streaminfo(vfs_handle_struct *handle,
 756                                          struct files_struct *fsp,
 757                                          const char *fname,
 758                                          TALLOC_CTX *mem_ctx,
 759                                          unsigned int *pnum_streams,
 760                                          struct stream_struct **pstreams)
 761 {
 762         SMB_STRUCT_STAT sbuf;
 763         int ret;
 764         NTSTATUS status;
 765         struct streaminfo_state state;
 766
 767         if ((fsp != NULL) && (fsp->fh->fd != -1)) {
 768                 ret = SMB_VFS_FSTAT(fsp, &sbuf);
 769         }
 770         else {
 771                 struct smb_filename *smb_fname = NULL;
 772                 smb_fname = synthetic_smb_fname(talloc_tos(), fname, NULL,
 773                                                 NULL);
 774                 if (smb_fname == NULL) {
 775                         return NT_STATUS_NO_MEMORY;
 776                 }
 777                 if (lp_posix_pathnames()) {
 778                         ret = SMB_VFS_LSTAT(handle->conn, smb_fname);
 779                 } else {
 780                         ret = SMB_VFS_STAT(handle->conn, smb_fname);
 781                 }
 782                 sbuf = smb_fname->st;
 783                 TALLOC_FREE(smb_fname);
 784         }
 785
 786         if (ret == -1) {
 787                 return map_nt_error_from_unix(errno);
 788         }
 789
 790         state.streams = *pstreams;
 791         state.num_streams = *pnum_streams;
 792         state.mem_ctx = mem_ctx;
 793         state.handle = handle;
 794         state.status = NT_STATUS_OK;
 795
 796         if (S_ISLNK(sbuf.st_ex_mode)) {
 797                 /*
 798                  * Currently we do't have SMB_VFS_LLISTXATTR
 799                  * inside the VFS which means there's no way
 800                  * to cope with a symlink when lp_posix_pathnames().
 801                  * returns true. For now ignore links.
 802                  * FIXME - by adding SMB_VFS_LLISTXATTR. JRA.
 803                  */
 804                 status = NT_STATUS_OK;
 805         } else {
 806                 status = walk_xattr_streams(handle->conn, fsp, fname,
 807                                     collect_one_stream, &state);
 808         }
 809
 810         if (!NT_STATUS_IS_OK(status)) {
 811                 TALLOC_FREE(state.streams);
 812                 return status;
 813         }
 814
 815         if (!NT_STATUS_IS_OK(state.status)) {
 816                 TALLOC_FREE(state.streams);
 817                 return state.status;
 818         }
 819
 820         *pnum_streams = state.num_streams;
 821         *pstreams = state.streams;
 822
 823         return SMB_VFS_NEXT_STREAMINFO(handle, fsp, fname, mem_ctx, pnum_streams, pstreams);
 824 }
 825
 826 static uint32_t streams_xattr_fs_capabilities(struct vfs_handle_struct *handle,
 827                         enum timestamp_set_resolution *p_ts_res)
 828 {
 829         return SMB_VFS_NEXT_FS_CAPABILITIES(handle, p_ts_res) | FILE_NAMED_STREAMS;
 830 }
 831
 832 static ssize_t streams_xattr_pwrite(vfs_handle_struct *handle,
 833                                     files_struct *fsp, const void *data,
 834                                     size_t n, off_t offset)
 835 {
 836         struct stream_io *sio =
 837                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 838         struct ea_struct ea;
 839         NTSTATUS status;
 840         int ret;
 841
 842         DEBUG(10, ("streams_xattr_pwrite called for %d bytes\n", (int)n));
 843
 844         if (sio == NULL) {
 845                 return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 846         }
 847
 848         if (!streams_xattr_recheck(sio)) {
 849                 return -1;
 850         }
 851
 852         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
 853                               sio->base, sio->xattr_name, &ea);
 854         if (!NT_STATUS_IS_OK(status)) {
 855                 return -1;
 856         }
 857
 858         if ((offset + n) > ea.value.length-1) {
 859                 uint8 *tmp;
 860
 861                 tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8,
 862                                            offset + n + 1);
 863
 864                 if (tmp == NULL) {
 865                         TALLOC_FREE(ea.value.data);
 866                         errno = ENOMEM;
 867                         return -1;
 868                 }
 869                 ea.value.data = tmp;
 870                 ea.value.length = offset + n + 1;
 871                 ea.value.data[offset+n] = 0;
 872         }
 873
 874         memcpy(ea.value.data + offset, data, n);
 875
 876         if (fsp->base_fsp->fh->fd != -1) {
 877                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
 878                                 sio->xattr_name,
 879                                 ea.value.data, ea.value.length, 0);
 880         } else {
 881                 ret = SMB_VFS_SETXATTR(fsp->conn,
 882                                        fsp->base_fsp->fsp_name->base_name,
 883                                 sio->xattr_name,
 884                                 ea.value.data, ea.value.length, 0);
 885         }
 886         TALLOC_FREE(ea.value.data);
 887
 888         if (ret == -1) {
 889                 return -1;
 890         }
 891
 892         return n;
 893 }
 894
 895 static ssize_t streams_xattr_pread(vfs_handle_struct *handle,
 896                                    files_struct *fsp, void *data,
 897                                    size_t n, off_t offset)
 898 {
 899         struct stream_io *sio =
 900                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 901         struct ea_struct ea;
 902         NTSTATUS status;
 903         size_t length, overlap;
 904
 905         DEBUG(10, ("streams_xattr_pread: offset=%d, size=%d\n",
 906                    (int)offset, (int)n));
 907
 908         if (sio == NULL) {
 909                 return SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
 910         }
 911
 912         if (!streams_xattr_recheck(sio)) {
 913                 return -1;
 914         }
 915
 916         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
 917                               sio->base, sio->xattr_name, &ea);
 918         if (!NT_STATUS_IS_OK(status)) {
 919                 return -1;
 920         }
 921
 922         length = ea.value.length-1;
 923
 924         DEBUG(10, ("streams_xattr_pread: get_ea_value returned %d bytes\n",
 925                    (int)length));
 926
 927         /* Attempt to read past EOF. */
 928         if (length <= offset) {
 929                 return 0;
 930         }
 931
 932         overlap = (offset + n) > length ? (length - offset) : n;
 933         memcpy(data, ea.value.data + offset, overlap);
 934
 935         TALLOC_FREE(ea.value.data);
 936         return overlap;
 937 }
 938
 939 static int streams_xattr_ftruncate(struct vfs_handle_struct *handle,
 940                                         struct files_struct *fsp,
 941                                         off_t offset)
 942 {
 943         int ret;
 944         uint8 *tmp;
 945         struct ea_struct ea;
 946         NTSTATUS status;
 947         struct stream_io *sio =
 948                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 949
 950         DEBUG(10, ("streams_xattr_ftruncate called for file %s offset %.0f\n",
 951                    fsp_str_dbg(fsp), (double)offset));
 952
 953         if (sio == NULL) {
 954                 return SMB_VFS_NEXT_FTRUNCATE(handle, fsp, offset);
 955         }
 956
 957         if (!streams_xattr_recheck(sio)) {
 958                 return -1;
 959         }
 960
 961         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
 962                               sio->base, sio->xattr_name, &ea);
 963         if (!NT_STATUS_IS_OK(status)) {
 964                 return -1;
 965         }
 966
 967         tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8,
 968                                    offset + 1);
 969
 970         if (tmp == NULL) {
 971                 TALLOC_FREE(ea.value.data);
 972                 errno = ENOMEM;
 973                 return -1;
 974         }
 975
 976         /* Did we expand ? */
 977         if (ea.value.length < offset + 1) {
 978                 memset(&tmp[ea.value.length], '\0',
 979                         offset + 1 - ea.value.length);
 980         }
 981
 982         ea.value.data = tmp;
 983         ea.value.length = offset + 1;
 984         ea.value.data[offset] = 0;
 985
 986         if (fsp->base_fsp->fh->fd != -1) {
 987                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
 988                                 sio->xattr_name,
 989                                 ea.value.data, ea.value.length, 0);
 990         } else {
 991                 ret = SMB_VFS_SETXATTR(fsp->conn,
 992                                        fsp->base_fsp->fsp_name->base_name,
 993                                 sio->xattr_name,
 994                                 ea.value.data, ea.value.length, 0);
 995         }
 996
 997         TALLOC_FREE(ea.value.data);
 998
 999         if (ret == -1) {
1000                 return -1;
1001         }
1002
1003         return 0;
1004 }
1005
1006 static int streams_xattr_fallocate(struct vfs_handle_struct *handle,
1007                                         struct files_struct *fsp,
1008                                         enum vfs_fallocate_mode mode,
1009                                         off_t offset,
1010                                         off_t len)
1011 {
1012         struct stream_io *sio =
1013                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1014
1015         DEBUG(10, ("streams_xattr_fallocate called for file %s offset %.0f"
1016                 "len = %.0f\n",
1017                 fsp_str_dbg(fsp), (double)offset, (double)len));
1018
1019         if (sio == NULL) {
1020                 return SMB_VFS_NEXT_FALLOCATE(handle, fsp, mode, offset, len);
1021         }
1022
1023         if (!streams_xattr_recheck(sio)) {
1024                 return -1;
1025         }
1026
1027         /* Let the pwrite code path handle it. */
1028         errno = ENOSYS;
1029         return -1;
1030 }
1031
1032
1033 static struct vfs_fn_pointers vfs_streams_xattr_fns = {
1034         .fs_capabilities_fn = streams_xattr_fs_capabilities,
1035         .open_fn = streams_xattr_open,
1036         .stat_fn = streams_xattr_stat,
1037         .fstat_fn = streams_xattr_fstat,
1038         .lstat_fn = streams_xattr_lstat,
1039         .pread_fn = streams_xattr_pread,
1040         .pwrite_fn = streams_xattr_pwrite,
1041         .unlink_fn = streams_xattr_unlink,
1042         .rename_fn = streams_xattr_rename,
1043         .ftruncate_fn = streams_xattr_ftruncate,
1044         .fallocate_fn = streams_xattr_fallocate,
1045         .streaminfo_fn = streams_xattr_streaminfo,
1046 };
1047
1048 NTSTATUS vfs_streams_xattr_init(void);
1049 NTSTATUS vfs_streams_xattr_init(void)
1050 {
1051         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_xattr",
1052                                 &vfs_streams_xattr_fns);
1053 }