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 streams_xattr_config {
  33         const char *prefix;
  34         size_t prefix_len;
  35         bool store_stream_type;
  36 };
  37
  38 struct stream_io {
  39         char *base;
  40         char *xattr_name;
  41         void *fsp_name_ptr;
  42         files_struct *fsp;
  43         vfs_handle_struct *handle;
  44 };
  45
  46 static SMB_INO_T stream_inode(const SMB_STRUCT_STAT *sbuf, const char *sname)
  47 {
  48         MD5_CTX ctx;
  49         unsigned char hash[16];
  50         SMB_INO_T result;
  51         char *upper_sname;
  52
  53         DEBUG(10, ("stream_inode called for %lu/%lu [%s]\n",
  54                    (unsigned long)sbuf->st_ex_dev,
  55                    (unsigned long)sbuf->st_ex_ino, sname));
  56
  57         upper_sname = talloc_strdup_upper(talloc_tos(), sname);
  58         SMB_ASSERT(upper_sname != NULL);
  59
  60         MD5Init(&ctx);
  61         MD5Update(&ctx, (const unsigned char *)&(sbuf->st_ex_dev),
  62                   sizeof(sbuf->st_ex_dev));
  63         MD5Update(&ctx, (const unsigned char *)&(sbuf->st_ex_ino),
  64                   sizeof(sbuf->st_ex_ino));
  65         MD5Update(&ctx, (unsigned char *)upper_sname,
  66                   talloc_get_size(upper_sname)-1);
  67         MD5Final(hash, &ctx);
  68
  69         TALLOC_FREE(upper_sname);
  70
  71         /* Hopefully all the variation is in the lower 4 (or 8) bytes! */
  72         memcpy(&result, hash, sizeof(result));
  73
  74         DEBUG(10, ("stream_inode returns %lu\n", (unsigned long)result));
  75
  76         return result;
  77 }
  78
  79 static ssize_t get_xattr_size(connection_struct *conn,
  80                                 files_struct *fsp,
  81                                 const char *fname,
  82                                 const char *xattr_name)
  83 {
  84         NTSTATUS status;
  85         struct ea_struct ea;
  86         ssize_t result;
  87
  88         status = get_ea_value(talloc_tos(), conn, fsp, fname,
  89                               xattr_name, &ea);
  90
  91         if (!NT_STATUS_IS_OK(status)) {
  92                 return -1;
  93         }
  94
  95         result = ea.value.length-1;
  96         TALLOC_FREE(ea.value.data);
  97         return result;
  98 }
  99
 100 /**
 101  * Given a stream name, populate xattr_name with the xattr name to use for
 102  * accessing the stream.
 103  */
 104 static NTSTATUS streams_xattr_get_name(vfs_handle_struct *handle,
 105                                        TALLOC_CTX *ctx,
 106                                        const char *stream_name,
 107                                        char **xattr_name)
 108 {
 109         char *sname;
 110         char *stype;
 111         struct streams_xattr_config *config;
 112
 113         SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
 114                                 return NT_STATUS_UNSUCCESSFUL);
 115
 116         sname = talloc_strdup(ctx, stream_name + 1);
 117         if (sname == NULL) {
 118                 return NT_STATUS_NO_MEMORY;
 119         }
 120
 121         /*
 122          * With vfs_fruit option "fruit:encoding = native" we're
 123          * already converting stream names that contain illegal NTFS
 124          * characters from their on-the-wire Unicode Private Range
 125          * encoding to their native ASCII representation.
 126          *
 127          * As as result the name of xattrs storing the streams (via
 128          * vfs_streams_xattr) may contain a colon, so we have to use
 129          * strrchr_m() instead of strchr_m() for matching the stream
 130          * type suffix.
 131          *
 132          * In check_path_syntax() we've already ensured the streamname
 133          * we got from the client is valid.
 134          */
 135         stype = strrchr_m(sname, ':');
 136
 137         if (stype) {
 138                 /*
 139                  * We only support one stream type: "$DATA"
 140                  */
 141                 if (strcasecmp_m(stype, ":$DATA") != 0) {
 142                         talloc_free(sname);
 143                         return NT_STATUS_INVALID_PARAMETER;
 144                 }
 145
 146                 /* Split name and type */
 147                 stype[0] = '\0';
 148         }
 149
 150         *xattr_name = talloc_asprintf(ctx, "%s%s%s",
 151                                       config->prefix,
 152                                       sname,
 153                                       config->store_stream_type ? ":$DATA" : "");
 154         if (*xattr_name == NULL) {
 155                 talloc_free(sname);
 156                 return NT_STATUS_NO_MEMORY;
 157         }
 158
 159         DEBUG(10, ("xattr_name: %s, stream_name: %s\n", *xattr_name,
 160                    stream_name));
 161
 162         talloc_free(sname);
 163         return NT_STATUS_OK;
 164 }
 165
 166 static bool streams_xattr_recheck(struct stream_io *sio)
 167 {
 168         NTSTATUS status;
 169         char *xattr_name = NULL;
 170
 171         if (sio->fsp->fsp_name == sio->fsp_name_ptr) {
 172                 return true;
 173         }
 174
 175         if (sio->fsp->fsp_name->stream_name == NULL) {
 176                 /* how can this happen */
 177                 errno = EINVAL;
 178                 return false;
 179         }
 180
 181         status = streams_xattr_get_name(sio->handle, talloc_tos(),
 182                                         sio->fsp->fsp_name->stream_name,
 183                                         &xattr_name);
 184         if (!NT_STATUS_IS_OK(status)) {
 185                 return false;
 186         }
 187
 188         TALLOC_FREE(sio->xattr_name);
 189         TALLOC_FREE(sio->base);
 190         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 191                                         xattr_name);
 192         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 193                                   sio->fsp->fsp_name->base_name);
 194         sio->fsp_name_ptr = sio->fsp->fsp_name;
 195
 196         TALLOC_FREE(xattr_name);
 197
 198         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 199                 return false;
 200         }
 201
 202         return true;
 203 }
 204
 205 /**
 206  * Helper to stat/lstat the base file of an smb_fname.
 207  */
 208 static int streams_xattr_stat_base(vfs_handle_struct *handle,
 209                                    struct smb_filename *smb_fname,
 210                                    bool follow_links)
 211 {
 212         char *tmp_stream_name;
 213         int result;
 214
 215         tmp_stream_name = smb_fname->stream_name;
 216         smb_fname->stream_name = NULL;
 217         if (follow_links) {
 218                 result = SMB_VFS_NEXT_STAT(handle, smb_fname);
 219         } else {
 220                 result = SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 221         }
 222         smb_fname->stream_name = tmp_stream_name;
 223         return result;
 224 }
 225
 226 static int streams_xattr_fstat(vfs_handle_struct *handle, files_struct *fsp,
 227                                SMB_STRUCT_STAT *sbuf)
 228 {
 229         struct smb_filename *smb_fname_base = NULL;
 230         int ret = -1;
 231         struct stream_io *io = (struct stream_io *)
 232                 VFS_FETCH_FSP_EXTENSION(handle, fsp);
 233
 234         DEBUG(10, ("streams_xattr_fstat called for %d\n", fsp->fh->fd));
 235
 236         if (io == NULL || fsp->base_fsp == NULL) {
 237                 return SMB_VFS_NEXT_FSTAT(handle, fsp, sbuf);
 238         }
 239
 240         if (!streams_xattr_recheck(io)) {
 241                 return -1;
 242         }
 243
 244         /* Create an smb_filename with stream_name == NULL. */
 245         smb_fname_base = synthetic_smb_fname(talloc_tos(), io->base,
 246                                              NULL, NULL);
 247         if (smb_fname_base == NULL) {
 248                 errno = ENOMEM;
 249                 return -1;
 250         }
 251
 252         if (lp_posix_pathnames()) {
 253                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname_base);
 254         } else {
 255                 ret = SMB_VFS_STAT(handle->conn, smb_fname_base);
 256         }
 257         *sbuf = smb_fname_base->st;
 258         TALLOC_FREE(smb_fname_base);
 259
 260         if (ret == -1) {
 261                 return -1;
 262         }
 263
 264         sbuf->st_ex_size = get_xattr_size(handle->conn, fsp->base_fsp,
 265                                         io->base, io->xattr_name);
 266         if (sbuf->st_ex_size == -1) {
 267                 return -1;
 268         }
 269
 270         DEBUG(10, ("sbuf->st_ex_size = %d\n", (int)sbuf->st_ex_size));
 271
 272         sbuf->st_ex_ino = stream_inode(sbuf, io->xattr_name);
 273         sbuf->st_ex_mode &= ~S_IFMT;
 274         sbuf->st_ex_mode |= S_IFREG;
 275         sbuf->st_ex_blocks = sbuf->st_ex_size / STAT_ST_BLOCKSIZE + 1;
 276
 277         return 0;
 278 }
 279
 280 static int streams_xattr_stat(vfs_handle_struct *handle,
 281                               struct smb_filename *smb_fname)
 282 {
 283         NTSTATUS status;
 284         int result = -1;
 285         char *xattr_name = NULL;
 286
 287         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 288                 return SMB_VFS_NEXT_STAT(handle, smb_fname);
 289         }
 290
 291         /* Note if lp_posix_paths() is true, we can never
 292          * get here as is_ntfs_stream_smb_fname() is
 293          * always false. So we never need worry about
 294          * not following links here. */
 295
 296         /* If the default stream is requested, just stat the base file. */
 297         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 298                 return streams_xattr_stat_base(handle, smb_fname, true);
 299         }
 300
 301         /* Populate the stat struct with info from the base file. */
 302         if (streams_xattr_stat_base(handle, smb_fname, true) == -1) {
 303                 return -1;
 304         }
 305
 306         /* Derive the xattr name to lookup. */
 307         status = streams_xattr_get_name(handle, talloc_tos(),
 308                                         smb_fname->stream_name, &xattr_name);
 309         if (!NT_STATUS_IS_OK(status)) {
 310                 errno = map_errno_from_nt_status(status);
 311                 return -1;
 312         }
 313
 314         /* Augment the base file's stat information before returning. */
 315         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 316                                                   smb_fname->base_name,
 317                                                   xattr_name);
 318         if (smb_fname->st.st_ex_size == -1) {
 319                 errno = ENOENT;
 320                 result = -1;
 321                 goto fail;
 322         }
 323
 324         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 325         smb_fname->st.st_ex_mode &= ~S_IFMT;
 326         smb_fname->st.st_ex_mode |= S_IFREG;
 327         smb_fname->st.st_ex_blocks =
 328             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 329
 330         result = 0;
 331  fail:
 332         TALLOC_FREE(xattr_name);
 333         return result;
 334 }
 335
 336 static int streams_xattr_lstat(vfs_handle_struct *handle,
 337                                struct smb_filename *smb_fname)
 338 {
 339         NTSTATUS status;
 340         int result = -1;
 341         char *xattr_name = NULL;
 342
 343         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 344                 return SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 345         }
 346
 347         /* If the default stream is requested, just stat the base file. */
 348         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 349                 return streams_xattr_stat_base(handle, smb_fname, false);
 350         }
 351
 352         /* Populate the stat struct with info from the base file. */
 353         if (streams_xattr_stat_base(handle, smb_fname, false) == -1) {
 354                 return -1;
 355         }
 356
 357         /* Derive the xattr name to lookup. */
 358         status = streams_xattr_get_name(handle, talloc_tos(),
 359                                         smb_fname->stream_name, &xattr_name);
 360         if (!NT_STATUS_IS_OK(status)) {
 361                 errno = map_errno_from_nt_status(status);
 362                 return -1;
 363         }
 364
 365         /* Augment the base file's stat information before returning. */
 366         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 367                                                   smb_fname->base_name,
 368                                                   xattr_name);
 369         if (smb_fname->st.st_ex_size == -1) {
 370                 errno = ENOENT;
 371                 result = -1;
 372                 goto fail;
 373         }
 374
 375         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 376         smb_fname->st.st_ex_mode &= ~S_IFMT;
 377         smb_fname->st.st_ex_mode |= S_IFREG;
 378         smb_fname->st.st_ex_blocks =
 379             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 380
 381         result = 0;
 382
 383  fail:
 384         TALLOC_FREE(xattr_name);
 385         return result;
 386 }
 387
 388 static int streams_xattr_open(vfs_handle_struct *handle,
 389                               struct smb_filename *smb_fname,
 390                               files_struct *fsp, int flags, mode_t mode)
 391 {
 392         NTSTATUS status;
 393         struct smb_filename *smb_fname_base = NULL;
 394         struct stream_io *sio;
 395         struct ea_struct ea;
 396         char *xattr_name = NULL;
 397         int baseflags;
 398         int hostfd = -1;
 399
 400         DEBUG(10, ("streams_xattr_open called for %s with flags 0x%x\n",
 401                    smb_fname_str_dbg(smb_fname), flags));
 402
 403         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 404                 return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 405         }
 406
 407         /* If the default stream is requested, just open the base file. */
 408         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 409                 char *tmp_stream_name;
 410                 int ret;
 411
 412                 tmp_stream_name = smb_fname->stream_name;
 413                 smb_fname->stream_name = NULL;
 414
 415                 ret = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 416
 417                 smb_fname->stream_name = tmp_stream_name;
 418
 419                 return ret;
 420         }
 421
 422         status = streams_xattr_get_name(handle, talloc_tos(),
 423                                         smb_fname->stream_name, &xattr_name);
 424         if (!NT_STATUS_IS_OK(status)) {
 425                 errno = map_errno_from_nt_status(status);
 426                 goto fail;
 427         }
 428
 429         /* Create an smb_filename with stream_name == NULL. */
 430         smb_fname_base = synthetic_smb_fname(
 431                 talloc_tos(), smb_fname->base_name, NULL, NULL);
 432         if (smb_fname_base == NULL) {
 433                 errno = ENOMEM;
 434                 goto fail;
 435         }
 436
 437         /*
 438          * We use baseflags to turn off nasty side-effects when opening the
 439          * underlying file.
 440          */
 441         baseflags = flags;
 442         baseflags &= ~O_TRUNC;
 443         baseflags &= ~O_EXCL;
 444         baseflags &= ~O_CREAT;
 445
 446         hostfd = SMB_VFS_OPEN(handle->conn, smb_fname_base, fsp,
 447                               baseflags, mode);
 448
 449         TALLOC_FREE(smb_fname_base);
 450
 451         /* It is legit to open a stream on a directory, but the base
 452          * fd has to be read-only.
 453          */
 454         if ((hostfd == -1) && (errno == EISDIR)) {
 455                 baseflags &= ~O_ACCMODE;
 456                 baseflags |= O_RDONLY;
 457                 hostfd = SMB_VFS_OPEN(handle->conn, smb_fname, fsp, baseflags,
 458                                       mode);
 459         }
 460
 461         if (hostfd == -1) {
 462                 goto fail;
 463         }
 464
 465         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 466                               smb_fname->base_name, xattr_name, &ea);
 467
 468         DEBUG(10, ("get_ea_value returned %s\n", nt_errstr(status)));
 469
 470         if (!NT_STATUS_IS_OK(status)
 471             && !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 472                 /*
 473                  * The base file is not there. This is an error even if we got
 474                  * O_CREAT, the higher levels should have created the base
 475                  * file for us.
 476                  */
 477                 DEBUG(10, ("streams_xattr_open: base file %s not around, "
 478                            "returning ENOENT\n", smb_fname->base_name));
 479                 errno = ENOENT;
 480                 goto fail;
 481         }
 482
 483         if ((!NT_STATUS_IS_OK(status) && (flags & O_CREAT)) ||
 484             (flags & O_TRUNC)) {
 485                 /*
 486                  * The attribute does not exist or needs to be truncated
 487                  */
 488
 489                 /*
 490                  * Darn, xattrs need at least 1 byte
 491                  */
 492                 char null = '\0';
 493
 494                 DEBUG(10, ("creating or truncating attribute %s on file %s\n",
 495                            xattr_name, smb_fname->base_name));
 496
 497                 if (fsp->base_fsp->fh->fd != -1) {
 498                         if (SMB_VFS_FSETXATTR(
 499                                         fsp->base_fsp, xattr_name,
 500                                         &null, sizeof(null),
 501                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 502                                 goto fail;
 503                         }
 504                 } else {
 505                         if (SMB_VFS_SETXATTR(
 506                                         handle->conn, smb_fname->base_name,
 507                                         xattr_name, &null, sizeof(null),
 508                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 509                                 goto fail;
 510                         }
 511                 }
 512         }
 513
 514         sio = (struct stream_io *)VFS_ADD_FSP_EXTENSION(handle, fsp,
 515                                                         struct stream_io,
 516                                                         NULL);
 517         if (sio == NULL) {
 518                 errno = ENOMEM;
 519                 goto fail;
 520         }
 521
 522         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 523                                         xattr_name);
 524         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 525                                   smb_fname->base_name);
 526         sio->fsp_name_ptr = fsp->fsp_name;
 527         sio->handle = handle;
 528         sio->fsp = fsp;
 529
 530         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 531                 errno = ENOMEM;
 532                 goto fail;
 533         }
 534
 535         return hostfd;
 536
 537  fail:
 538         if (hostfd >= 0) {
 539                 /*
 540                  * BUGBUGBUG -- we would need to call fd_close_posix here, but
 541                  * we don't have a full fsp yet
 542                  */
 543                 fsp->fh->fd = hostfd;
 544                 SMB_VFS_CLOSE(fsp);
 545         }
 546
 547         return -1;
 548 }
 549
 550 static int streams_xattr_unlink(vfs_handle_struct *handle,
 551                                 const struct smb_filename *smb_fname)
 552 {
 553         NTSTATUS status;
 554         int ret = -1;
 555         char *xattr_name = NULL;
 556
 557         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 558                 return SMB_VFS_NEXT_UNLINK(handle, smb_fname);
 559         }
 560
 561         /* If the default stream is requested, just open the base file. */
 562         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 563                 struct smb_filename *smb_fname_base = NULL;
 564
 565                 smb_fname_base = cp_smb_filename(talloc_tos(), smb_fname);
 566                 if (smb_fname_base == NULL) {
 567                         errno = ENOMEM;
 568                         return -1;
 569                 }
 570
 571                 ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_base);
 572
 573                 TALLOC_FREE(smb_fname_base);
 574                 return ret;
 575         }
 576
 577         status = streams_xattr_get_name(handle, talloc_tos(),
 578                                         smb_fname->stream_name, &xattr_name);
 579         if (!NT_STATUS_IS_OK(status)) {
 580                 errno = map_errno_from_nt_status(status);
 581                 goto fail;
 582         }
 583
 584         ret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname->base_name, xattr_name);
 585
 586         if ((ret == -1) && (errno == ENOATTR)) {
 587                 errno = ENOENT;
 588                 goto fail;
 589         }
 590
 591         ret = 0;
 592
 593  fail:
 594         TALLOC_FREE(xattr_name);
 595         return ret;
 596 }
 597
 598 static int streams_xattr_rename(vfs_handle_struct *handle,
 599                                 const struct smb_filename *smb_fname_src,
 600                                 const struct smb_filename *smb_fname_dst)
 601 {
 602         NTSTATUS status;
 603         int ret = -1;
 604         char *src_xattr_name = NULL;
 605         char *dst_xattr_name = NULL;
 606         bool src_is_stream, dst_is_stream;
 607         ssize_t oret;
 608         ssize_t nret;
 609         struct ea_struct ea;
 610
 611         src_is_stream = is_ntfs_stream_smb_fname(smb_fname_src);
 612         dst_is_stream = is_ntfs_stream_smb_fname(smb_fname_dst);
 613
 614         if (!src_is_stream && !dst_is_stream) {
 615                 return SMB_VFS_NEXT_RENAME(handle, smb_fname_src,
 616                                            smb_fname_dst);
 617         }
 618
 619         /* For now don't allow renames from or to the default stream. */
 620         if (is_ntfs_default_stream_smb_fname(smb_fname_src) ||
 621             is_ntfs_default_stream_smb_fname(smb_fname_dst)) {
 622                 errno = ENOSYS;
 623                 goto done;
 624         }
 625
 626         /* Don't rename if the streams are identical. */
 627         if (strcasecmp_m(smb_fname_src->stream_name,
 628                        smb_fname_dst->stream_name) == 0) {
 629                 goto done;
 630         }
 631
 632         /* Get the xattr names. */
 633         status = streams_xattr_get_name(handle, talloc_tos(),
 634                                         smb_fname_src->stream_name,
 635                                         &src_xattr_name);
 636         if (!NT_STATUS_IS_OK(status)) {
 637                 errno = map_errno_from_nt_status(status);
 638                 goto fail;
 639         }
 640         status = streams_xattr_get_name(handle, talloc_tos(),
 641                                         smb_fname_dst->stream_name,
 642                                         &dst_xattr_name);
 643         if (!NT_STATUS_IS_OK(status)) {
 644                 errno = map_errno_from_nt_status(status);
 645                 goto fail;
 646         }
 647
 648         /* read the old stream */
 649         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 650                               smb_fname_src->base_name, src_xattr_name, &ea);
 651         if (!NT_STATUS_IS_OK(status)) {
 652                 errno = ENOENT;
 653                 goto fail;
 654         }
 655
 656         /* (over)write the new stream */
 657         nret = SMB_VFS_SETXATTR(handle->conn, smb_fname_src->base_name,
 658                                 dst_xattr_name, ea.value.data, ea.value.length,
 659                                 0);
 660         if (nret < 0) {
 661                 if (errno == ENOATTR) {
 662                         errno = ENOENT;
 663                 }
 664                 goto fail;
 665         }
 666
 667         /* remove the old stream */
 668         oret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname_src->base_name,
 669                                    src_xattr_name);
 670         if (oret < 0) {
 671                 if (errno == ENOATTR) {
 672                         errno = ENOENT;
 673                 }
 674                 goto fail;
 675         }
 676
 677  done:
 678         errno = 0;
 679         ret = 0;
 680  fail:
 681         TALLOC_FREE(src_xattr_name);
 682         TALLOC_FREE(dst_xattr_name);
 683         return ret;
 684 }
 685
 686 static NTSTATUS walk_xattr_streams(vfs_handle_struct *handle, files_struct *fsp,
 687                                    const char *fname,
 688                                    bool (*fn)(struct ea_struct *ea,
 689                                               void *private_data),
 690                                    void *private_data)
 691 {
 692         NTSTATUS status;
 693         char **names;
 694         size_t i, num_names;
 695         struct streams_xattr_config *config;
 696
 697         SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
 698                                 return NT_STATUS_UNSUCCESSFUL);
 699
 700         status = get_ea_names_from_file(talloc_tos(), handle->conn, fsp, fname,
 701                                         &names, &num_names);
 702         if (!NT_STATUS_IS_OK(status)) {
 703                 return status;
 704         }
 705
 706         for (i=0; i<num_names; i++) {
 707                 struct ea_struct ea;
 708
 709                 /*
 710                  * We want to check with samba_private_attr_name()
 711                  * whether the xattr name is a private one,
 712                  * unfortunately it flags xattrs that begin with the
 713                  * default streams prefix as private.
 714                  *
 715                  * By only calling samba_private_attr_name() in case
 716                  * the xattr does NOT begin with the default prefix,
 717                  * we know that if it returns 'true' it definitely one
 718                  * of our internal xattr like "user.DOSATTRIB".
 719                  */
 720                 if (strncasecmp_m(names[i], SAMBA_XATTR_DOSSTREAM_PREFIX,
 721                                   strlen(SAMBA_XATTR_DOSSTREAM_PREFIX)) != 0) {
 722                         if (samba_private_attr_name(names[i])) {
 723                                 continue;
 724                         }
 725                 }
 726
 727                 if (strncmp(names[i], config->prefix,
 728                             config->prefix_len) != 0) {
 729                         continue;
 730                 }
 731
 732                 status = get_ea_value(names, handle->conn, fsp, fname,
 733                                       names[i], &ea);
 734                 if (!NT_STATUS_IS_OK(status)) {
 735                         DEBUG(10, ("Could not get ea %s for file %s: %s\n",
 736                                    names[i], fname, nt_errstr(status)));
 737                         continue;
 738                 }
 739
 740                 ea.name = talloc_asprintf(
 741                         ea.value.data, ":%s%s",
 742                         names[i] + config->prefix_len,
 743                         config->store_stream_type ? "" : ":$DATA");
 744                 if (ea.name == NULL) {
 745                         DEBUG(0, ("talloc failed\n"));
 746                         continue;
 747                 }
 748
 749                 if (!fn(&ea, private_data)) {
 750                         TALLOC_FREE(ea.value.data);
 751                         return NT_STATUS_OK;
 752                 }
 753
 754                 TALLOC_FREE(ea.value.data);
 755         }
 756
 757         TALLOC_FREE(names);
 758         return NT_STATUS_OK;
 759 }
 760
 761 static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
 762                            struct stream_struct **streams,
 763                            const char *name, off_t size,
 764                            off_t alloc_size)
 765 {
 766         struct stream_struct *tmp;
 767
 768         tmp = talloc_realloc(mem_ctx, *streams, struct stream_struct,
 769                                    (*num_streams)+1);
 770         if (tmp == NULL) {
 771                 return false;
 772         }
 773
 774         tmp[*num_streams].name = talloc_strdup(tmp, name);
 775         if (tmp[*num_streams].name == NULL) {
 776                 return false;
 777         }
 778
 779         tmp[*num_streams].size = size;
 780         tmp[*num_streams].alloc_size = alloc_size;
 781
 782         *streams = tmp;
 783         *num_streams += 1;
 784         return true;
 785 }
 786
 787 struct streaminfo_state {
 788         TALLOC_CTX *mem_ctx;
 789         vfs_handle_struct *handle;
 790         unsigned int num_streams;
 791         struct stream_struct *streams;
 792         NTSTATUS status;
 793 };
 794
 795 static bool collect_one_stream(struct ea_struct *ea, void *private_data)
 796 {
 797         struct streaminfo_state *state =
 798                 (struct streaminfo_state *)private_data;
 799
 800         if (!add_one_stream(state->mem_ctx,
 801                             &state->num_streams, &state->streams,
 802                             ea->name, ea->value.length-1,
 803                             smb_roundup(state->handle->conn,
 804                                         ea->value.length-1))) {
 805                 state->status = NT_STATUS_NO_MEMORY;
 806                 return false;
 807         }
 808
 809         return true;
 810 }
 811
 812 static NTSTATUS streams_xattr_streaminfo(vfs_handle_struct *handle,
 813                                          struct files_struct *fsp,
 814                                          const char *fname,
 815                                          TALLOC_CTX *mem_ctx,
 816                                          unsigned int *pnum_streams,
 817                                          struct stream_struct **pstreams)
 818 {
 819         SMB_STRUCT_STAT sbuf;
 820         int ret;
 821         NTSTATUS status;
 822         struct streaminfo_state state;
 823
 824         if ((fsp != NULL) && (fsp->fh->fd != -1)) {
 825                 ret = SMB_VFS_FSTAT(fsp, &sbuf);
 826         }
 827         else {
 828                 struct smb_filename *smb_fname = NULL;
 829                 smb_fname = synthetic_smb_fname(talloc_tos(), fname, NULL,
 830                                                 NULL);
 831                 if (smb_fname == NULL) {
 832                         return NT_STATUS_NO_MEMORY;
 833                 }
 834                 if (lp_posix_pathnames()) {
 835                         ret = SMB_VFS_LSTAT(handle->conn, smb_fname);
 836                 } else {
 837                         ret = SMB_VFS_STAT(handle->conn, smb_fname);
 838                 }
 839                 sbuf = smb_fname->st;
 840                 TALLOC_FREE(smb_fname);
 841         }
 842
 843         if (ret == -1) {
 844                 return map_nt_error_from_unix(errno);
 845         }
 846
 847         state.streams = *pstreams;
 848         state.num_streams = *pnum_streams;
 849         state.mem_ctx = mem_ctx;
 850         state.handle = handle;
 851         state.status = NT_STATUS_OK;
 852
 853         if (S_ISLNK(sbuf.st_ex_mode)) {
 854                 /*
 855                  * Currently we do't have SMB_VFS_LLISTXATTR
 856                  * inside the VFS which means there's no way
 857                  * to cope with a symlink when lp_posix_pathnames().
 858                  * returns true. For now ignore links.
 859                  * FIXME - by adding SMB_VFS_LLISTXATTR. JRA.
 860                  */
 861                 status = NT_STATUS_OK;
 862         } else {
 863                 status = walk_xattr_streams(handle, fsp, fname,
 864                                     collect_one_stream, &state);
 865         }
 866
 867         if (!NT_STATUS_IS_OK(status)) {
 868                 TALLOC_FREE(state.streams);
 869                 return status;
 870         }
 871
 872         if (!NT_STATUS_IS_OK(state.status)) {
 873                 TALLOC_FREE(state.streams);
 874                 return state.status;
 875         }
 876
 877         *pnum_streams = state.num_streams;
 878         *pstreams = state.streams;
 879
 880         return SMB_VFS_NEXT_STREAMINFO(handle, fsp, fname, mem_ctx, pnum_streams, pstreams);
 881 }
 882
 883 static uint32_t streams_xattr_fs_capabilities(struct vfs_handle_struct *handle,
 884                         enum timestamp_set_resolution *p_ts_res)
 885 {
 886         return SMB_VFS_NEXT_FS_CAPABILITIES(handle, p_ts_res) | FILE_NAMED_STREAMS;
 887 }
 888
 889 static int streams_xattr_connect(vfs_handle_struct *handle,
 890                                  const char *service, const char *user)
 891 {
 892         struct streams_xattr_config *config;
 893         const char *default_prefix = SAMBA_XATTR_DOSSTREAM_PREFIX;
 894         const char *prefix;
 895         int rc;
 896
 897         rc = SMB_VFS_NEXT_CONNECT(handle, service, user);
 898         if (rc != 0) {
 899                 return rc;
 900         }
 901
 902         config = talloc_zero(handle->conn, struct streams_xattr_config);
 903         if (config == NULL) {
 904                 DEBUG(1, ("talloc_zero() failed\n"));
 905                 errno = ENOMEM;
 906                 return -1;
 907         }
 908
 909         prefix = lp_parm_const_string(SNUM(handle->conn),
 910                                       "streams_xattr", "prefix",
 911                                       default_prefix);
 912         config->prefix = talloc_strdup(config, prefix);
 913         if (config->prefix == NULL) {
 914                 DEBUG(1, ("talloc_strdup() failed\n"));
 915                 errno = ENOMEM;
 916                 return -1;
 917         }
 918         config->prefix_len = strlen(config->prefix);
 919         DEBUG(10, ("streams_xattr using stream prefix: %s\n", config->prefix));
 920
 921         config->store_stream_type = lp_parm_bool(SNUM(handle->conn),
 922                                                  "streams_xattr",
 923                                                  "store_stream_type",
 924                                                  true);
 925
 926         SMB_VFS_HANDLE_SET_DATA(handle, config,
 927                                 NULL, struct stream_xattr_config,
 928                                 return -1);
 929
 930         return 0;
 931 }
 932
 933 static ssize_t streams_xattr_pwrite(vfs_handle_struct *handle,
 934                                     files_struct *fsp, const void *data,
 935                                     size_t n, off_t offset)
 936 {
 937         struct stream_io *sio =
 938                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 939         struct ea_struct ea;
 940         NTSTATUS status;
 941         int ret;
 942
 943         DEBUG(10, ("streams_xattr_pwrite called for %d bytes\n", (int)n));
 944
 945         if (sio == NULL) {
 946                 return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 947         }
 948
 949         if (!streams_xattr_recheck(sio)) {
 950                 return -1;
 951         }
 952
 953         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
 954                               sio->base, sio->xattr_name, &ea);
 955         if (!NT_STATUS_IS_OK(status)) {
 956                 return -1;
 957         }
 958
 959         if ((offset + n) > ea.value.length-1) {
 960                 uint8_t *tmp;
 961
 962                 tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8_t,
 963                                            offset + n + 1);
 964
 965                 if (tmp == NULL) {
 966                         TALLOC_FREE(ea.value.data);
 967                         errno = ENOMEM;
 968                         return -1;
 969                 }
 970                 ea.value.data = tmp;
 971                 ea.value.length = offset + n + 1;
 972                 ea.value.data[offset+n] = 0;
 973         }
 974
 975         memcpy(ea.value.data + offset, data, n);
 976
 977         if (fsp->base_fsp->fh->fd != -1) {
 978                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
 979                                 sio->xattr_name,
 980                                 ea.value.data, ea.value.length, 0);
 981         } else {
 982                 ret = SMB_VFS_SETXATTR(fsp->conn,
 983                                        fsp->base_fsp->fsp_name->base_name,
 984                                 sio->xattr_name,
 985                                 ea.value.data, ea.value.length, 0);
 986         }
 987         TALLOC_FREE(ea.value.data);
 988
 989         if (ret == -1) {
 990                 return -1;
 991         }
 992
 993         return n;
 994 }
 995
 996 static ssize_t streams_xattr_pread(vfs_handle_struct *handle,
 997                                    files_struct *fsp, void *data,
 998                                    size_t n, off_t offset)
 999 {
1000         struct stream_io *sio =
1001                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1002         struct ea_struct ea;
1003         NTSTATUS status;
1004         size_t length, overlap;
1005
1006         DEBUG(10, ("streams_xattr_pread: offset=%d, size=%d\n",
1007                    (int)offset, (int)n));
1008
1009         if (sio == NULL) {
1010                 return SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
1011         }
1012
1013         if (!streams_xattr_recheck(sio)) {
1014                 return -1;
1015         }
1016
1017         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
1018                               sio->base, sio->xattr_name, &ea);
1019         if (!NT_STATUS_IS_OK(status)) {
1020                 return -1;
1021         }
1022
1023         length = ea.value.length-1;
1024
1025         DEBUG(10, ("streams_xattr_pread: get_ea_value returned %d bytes\n",
1026                    (int)length));
1027
1028         /* Attempt to read past EOF. */
1029         if (length <= offset) {
1030                 return 0;
1031         }
1032
1033         overlap = (offset + n) > length ? (length - offset) : n;
1034         memcpy(data, ea.value.data + offset, overlap);
1035
1036         TALLOC_FREE(ea.value.data);
1037         return overlap;
1038 }
1039
1040 static int streams_xattr_ftruncate(struct vfs_handle_struct *handle,
1041                                         struct files_struct *fsp,
1042                                         off_t offset)
1043 {
1044         int ret;
1045         uint8_t *tmp;
1046         struct ea_struct ea;
1047         NTSTATUS status;
1048         struct stream_io *sio =
1049                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1050
1051         DEBUG(10, ("streams_xattr_ftruncate called for file %s offset %.0f\n",
1052                    fsp_str_dbg(fsp), (double)offset));
1053
1054         if (sio == NULL) {
1055                 return SMB_VFS_NEXT_FTRUNCATE(handle, fsp, offset);
1056         }
1057
1058         if (!streams_xattr_recheck(sio)) {
1059                 return -1;
1060         }
1061
1062         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
1063                               sio->base, sio->xattr_name, &ea);
1064         if (!NT_STATUS_IS_OK(status)) {
1065                 return -1;
1066         }
1067
1068         tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8_t,
1069                                    offset + 1);
1070
1071         if (tmp == NULL) {
1072                 TALLOC_FREE(ea.value.data);
1073                 errno = ENOMEM;
1074                 return -1;
1075         }
1076
1077         /* Did we expand ? */
1078         if (ea.value.length < offset + 1) {
1079                 memset(&tmp[ea.value.length], '\0',
1080                         offset + 1 - ea.value.length);
1081         }
1082
1083         ea.value.data = tmp;
1084         ea.value.length = offset + 1;
1085         ea.value.data[offset] = 0;
1086
1087         if (fsp->base_fsp->fh->fd != -1) {
1088                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
1089                                 sio->xattr_name,
1090                                 ea.value.data, ea.value.length, 0);
1091         } else {
1092                 ret = SMB_VFS_SETXATTR(fsp->conn,
1093                                        fsp->base_fsp->fsp_name->base_name,
1094                                 sio->xattr_name,
1095                                 ea.value.data, ea.value.length, 0);
1096         }
1097
1098         TALLOC_FREE(ea.value.data);
1099
1100         if (ret == -1) {
1101                 return -1;
1102         }
1103
1104         return 0;
1105 }
1106
1107 static int streams_xattr_fallocate(struct vfs_handle_struct *handle,
1108                                         struct files_struct *fsp,
1109                                         uint32_t mode,
1110                                         off_t offset,
1111                                         off_t len)
1112 {
1113         struct stream_io *sio =
1114                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1115
1116         DEBUG(10, ("streams_xattr_fallocate called for file %s offset %.0f"
1117                 "len = %.0f\n",
1118                 fsp_str_dbg(fsp), (double)offset, (double)len));
1119
1120         if (sio == NULL) {
1121                 return SMB_VFS_NEXT_FALLOCATE(handle, fsp, mode, offset, len);
1122         }
1123
1124         if (!streams_xattr_recheck(sio)) {
1125                 return -1;
1126         }
1127
1128         /* Let the pwrite code path handle it. */
1129         errno = ENOSYS;
1130         return -1;
1131 }
1132
1133
1134 static struct vfs_fn_pointers vfs_streams_xattr_fns = {
1135         .fs_capabilities_fn = streams_xattr_fs_capabilities,
1136         .connect_fn = streams_xattr_connect,
1137         .open_fn = streams_xattr_open,
1138         .stat_fn = streams_xattr_stat,
1139         .fstat_fn = streams_xattr_fstat,
1140         .lstat_fn = streams_xattr_lstat,
1141         .pread_fn = streams_xattr_pread,
1142         .pwrite_fn = streams_xattr_pwrite,
1143         .unlink_fn = streams_xattr_unlink,
1144         .rename_fn = streams_xattr_rename,
1145         .ftruncate_fn = streams_xattr_ftruncate,
1146         .fallocate_fn = streams_xattr_fallocate,
1147         .streaminfo_fn = streams_xattr_streaminfo,
1148 };
1149
1150 NTSTATUS vfs_streams_xattr_init(void);
1151 NTSTATUS vfs_streams_xattr_init(void)
1152 {
1153         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_xattr",
1154                                 &vfs_streams_xattr_fns);
1155 }