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(),
 246                                         io->base,
 247                                         NULL,
 248                                         NULL,
 249                                         fsp->fsp_name->flags);
 250         if (smb_fname_base == NULL) {
 251                 errno = ENOMEM;
 252                 return -1;
 253         }
 254
 255         if (smb_fname_base->flags & SMB_FILENAME_POSIX_PATH) {
 256                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname_base);
 257         } else {
 258                 ret = SMB_VFS_STAT(handle->conn, smb_fname_base);
 259         }
 260         *sbuf = smb_fname_base->st;
 261         TALLOC_FREE(smb_fname_base);
 262
 263         if (ret == -1) {
 264                 return -1;
 265         }
 266
 267         sbuf->st_ex_size = get_xattr_size(handle->conn, fsp->base_fsp,
 268                                         io->base, io->xattr_name);
 269         if (sbuf->st_ex_size == -1) {
 270                 return -1;
 271         }
 272
 273         DEBUG(10, ("sbuf->st_ex_size = %d\n", (int)sbuf->st_ex_size));
 274
 275         sbuf->st_ex_ino = stream_inode(sbuf, io->xattr_name);
 276         sbuf->st_ex_mode &= ~S_IFMT;
 277         sbuf->st_ex_mode |= S_IFREG;
 278         sbuf->st_ex_blocks = sbuf->st_ex_size / STAT_ST_BLOCKSIZE + 1;
 279
 280         return 0;
 281 }
 282
 283 static int streams_xattr_stat(vfs_handle_struct *handle,
 284                               struct smb_filename *smb_fname)
 285 {
 286         NTSTATUS status;
 287         int result = -1;
 288         char *xattr_name = NULL;
 289
 290         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 291                 return SMB_VFS_NEXT_STAT(handle, smb_fname);
 292         }
 293
 294         /* Note if lp_posix_paths() is true, we can never
 295          * get here as is_ntfs_stream_smb_fname() is
 296          * always false. So we never need worry about
 297          * not following links here. */
 298
 299         /* If the default stream is requested, just stat the base file. */
 300         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 301                 return streams_xattr_stat_base(handle, smb_fname, true);
 302         }
 303
 304         /* Populate the stat struct with info from the base file. */
 305         if (streams_xattr_stat_base(handle, smb_fname, true) == -1) {
 306                 return -1;
 307         }
 308
 309         /* Derive the xattr name to lookup. */
 310         status = streams_xattr_get_name(handle, talloc_tos(),
 311                                         smb_fname->stream_name, &xattr_name);
 312         if (!NT_STATUS_IS_OK(status)) {
 313                 errno = map_errno_from_nt_status(status);
 314                 return -1;
 315         }
 316
 317         /* Augment the base file's stat information before returning. */
 318         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 319                                                   smb_fname->base_name,
 320                                                   xattr_name);
 321         if (smb_fname->st.st_ex_size == -1) {
 322                 errno = ENOENT;
 323                 result = -1;
 324                 goto fail;
 325         }
 326
 327         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 328         smb_fname->st.st_ex_mode &= ~S_IFMT;
 329         smb_fname->st.st_ex_mode |= S_IFREG;
 330         smb_fname->st.st_ex_blocks =
 331             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 332
 333         result = 0;
 334  fail:
 335         TALLOC_FREE(xattr_name);
 336         return result;
 337 }
 338
 339 static int streams_xattr_lstat(vfs_handle_struct *handle,
 340                                struct smb_filename *smb_fname)
 341 {
 342         NTSTATUS status;
 343         int result = -1;
 344         char *xattr_name = NULL;
 345
 346         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 347                 return SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 348         }
 349
 350         /* If the default stream is requested, just stat the base file. */
 351         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 352                 return streams_xattr_stat_base(handle, smb_fname, false);
 353         }
 354
 355         /* Populate the stat struct with info from the base file. */
 356         if (streams_xattr_stat_base(handle, smb_fname, false) == -1) {
 357                 return -1;
 358         }
 359
 360         /* Derive the xattr name to lookup. */
 361         status = streams_xattr_get_name(handle, talloc_tos(),
 362                                         smb_fname->stream_name, &xattr_name);
 363         if (!NT_STATUS_IS_OK(status)) {
 364                 errno = map_errno_from_nt_status(status);
 365                 return -1;
 366         }
 367
 368         /* Augment the base file's stat information before returning. */
 369         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 370                                                   smb_fname->base_name,
 371                                                   xattr_name);
 372         if (smb_fname->st.st_ex_size == -1) {
 373                 errno = ENOENT;
 374                 result = -1;
 375                 goto fail;
 376         }
 377
 378         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 379         smb_fname->st.st_ex_mode &= ~S_IFMT;
 380         smb_fname->st.st_ex_mode |= S_IFREG;
 381         smb_fname->st.st_ex_blocks =
 382             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 383
 384         result = 0;
 385
 386  fail:
 387         TALLOC_FREE(xattr_name);
 388         return result;
 389 }
 390
 391 static int streams_xattr_open(vfs_handle_struct *handle,
 392                               struct smb_filename *smb_fname,
 393                               files_struct *fsp, int flags, mode_t mode)
 394 {
 395         NTSTATUS status;
 396         struct smb_filename *smb_fname_base = NULL;
 397         struct stream_io *sio;
 398         struct ea_struct ea;
 399         char *xattr_name = NULL;
 400         int baseflags;
 401         int hostfd = -1;
 402
 403         DEBUG(10, ("streams_xattr_open called for %s with flags 0x%x\n",
 404                    smb_fname_str_dbg(smb_fname), flags));
 405
 406         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 407                 return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 408         }
 409
 410         /* If the default stream is requested, just open the base file. */
 411         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 412                 char *tmp_stream_name;
 413                 int ret;
 414
 415                 tmp_stream_name = smb_fname->stream_name;
 416                 smb_fname->stream_name = NULL;
 417
 418                 ret = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 419
 420                 smb_fname->stream_name = tmp_stream_name;
 421
 422                 return ret;
 423         }
 424
 425         status = streams_xattr_get_name(handle, talloc_tos(),
 426                                         smb_fname->stream_name, &xattr_name);
 427         if (!NT_STATUS_IS_OK(status)) {
 428                 errno = map_errno_from_nt_status(status);
 429                 goto fail;
 430         }
 431
 432         /* Create an smb_filename with stream_name == NULL. */
 433         smb_fname_base = synthetic_smb_fname(talloc_tos(),
 434                                 smb_fname->base_name,
 435                                 NULL,
 436                                 NULL,
 437                                 smb_fname->flags);
 438         if (smb_fname_base == NULL) {
 439                 errno = ENOMEM;
 440                 goto fail;
 441         }
 442
 443         /*
 444          * We use baseflags to turn off nasty side-effects when opening the
 445          * underlying file.
 446          */
 447         baseflags = flags;
 448         baseflags &= ~O_TRUNC;
 449         baseflags &= ~O_EXCL;
 450         baseflags &= ~O_CREAT;
 451
 452         hostfd = SMB_VFS_OPEN(handle->conn, smb_fname_base, fsp,
 453                               baseflags, mode);
 454
 455         TALLOC_FREE(smb_fname_base);
 456
 457         /* It is legit to open a stream on a directory, but the base
 458          * fd has to be read-only.
 459          */
 460         if ((hostfd == -1) && (errno == EISDIR)) {
 461                 baseflags &= ~O_ACCMODE;
 462                 baseflags |= O_RDONLY;
 463                 hostfd = SMB_VFS_OPEN(handle->conn, smb_fname, fsp, baseflags,
 464                                       mode);
 465         }
 466
 467         if (hostfd == -1) {
 468                 goto fail;
 469         }
 470
 471         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 472                               smb_fname->base_name, xattr_name, &ea);
 473
 474         DEBUG(10, ("get_ea_value returned %s\n", nt_errstr(status)));
 475
 476         if (!NT_STATUS_IS_OK(status)
 477             && !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 478                 /*
 479                  * The base file is not there. This is an error even if we got
 480                  * O_CREAT, the higher levels should have created the base
 481                  * file for us.
 482                  */
 483                 DEBUG(10, ("streams_xattr_open: base file %s not around, "
 484                            "returning ENOENT\n", smb_fname->base_name));
 485                 errno = ENOENT;
 486                 goto fail;
 487         }
 488
 489         if ((!NT_STATUS_IS_OK(status) && (flags & O_CREAT)) ||
 490             (flags & O_TRUNC)) {
 491                 /*
 492                  * The attribute does not exist or needs to be truncated
 493                  */
 494
 495                 /*
 496                  * Darn, xattrs need at least 1 byte
 497                  */
 498                 char null = '\0';
 499
 500                 DEBUG(10, ("creating or truncating attribute %s on file %s\n",
 501                            xattr_name, smb_fname->base_name));
 502
 503                 if (fsp->base_fsp->fh->fd != -1) {
 504                         if (SMB_VFS_FSETXATTR(
 505                                         fsp->base_fsp, xattr_name,
 506                                         &null, sizeof(null),
 507                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 508                                 goto fail;
 509                         }
 510                 } else {
 511                         if (SMB_VFS_SETXATTR(
 512                                         handle->conn, smb_fname->base_name,
 513                                         xattr_name, &null, sizeof(null),
 514                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 515                                 goto fail;
 516                         }
 517                 }
 518         }
 519
 520         sio = (struct stream_io *)VFS_ADD_FSP_EXTENSION(handle, fsp,
 521                                                         struct stream_io,
 522                                                         NULL);
 523         if (sio == NULL) {
 524                 errno = ENOMEM;
 525                 goto fail;
 526         }
 527
 528         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 529                                         xattr_name);
 530         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 531                                   smb_fname->base_name);
 532         sio->fsp_name_ptr = fsp->fsp_name;
 533         sio->handle = handle;
 534         sio->fsp = fsp;
 535
 536         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 537                 errno = ENOMEM;
 538                 goto fail;
 539         }
 540
 541         return hostfd;
 542
 543  fail:
 544         if (hostfd >= 0) {
 545                 /*
 546                  * BUGBUGBUG -- we would need to call fd_close_posix here, but
 547                  * we don't have a full fsp yet
 548                  */
 549                 fsp->fh->fd = hostfd;
 550                 SMB_VFS_CLOSE(fsp);
 551         }
 552
 553         return -1;
 554 }
 555
 556 static int streams_xattr_unlink(vfs_handle_struct *handle,
 557                                 const struct smb_filename *smb_fname)
 558 {
 559         NTSTATUS status;
 560         int ret = -1;
 561         char *xattr_name = NULL;
 562
 563         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 564                 return SMB_VFS_NEXT_UNLINK(handle, smb_fname);
 565         }
 566
 567         /* If the default stream is requested, just open the base file. */
 568         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 569                 struct smb_filename *smb_fname_base = NULL;
 570
 571                 smb_fname_base = cp_smb_filename(talloc_tos(), smb_fname);
 572                 if (smb_fname_base == NULL) {
 573                         errno = ENOMEM;
 574                         return -1;
 575                 }
 576
 577                 ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_base);
 578
 579                 TALLOC_FREE(smb_fname_base);
 580                 return ret;
 581         }
 582
 583         status = streams_xattr_get_name(handle, talloc_tos(),
 584                                         smb_fname->stream_name, &xattr_name);
 585         if (!NT_STATUS_IS_OK(status)) {
 586                 errno = map_errno_from_nt_status(status);
 587                 goto fail;
 588         }
 589
 590         ret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname->base_name, xattr_name);
 591
 592         if ((ret == -1) && (errno == ENOATTR)) {
 593                 errno = ENOENT;
 594                 goto fail;
 595         }
 596
 597         ret = 0;
 598
 599  fail:
 600         TALLOC_FREE(xattr_name);
 601         return ret;
 602 }
 603
 604 static int streams_xattr_rename(vfs_handle_struct *handle,
 605                                 const struct smb_filename *smb_fname_src,
 606                                 const struct smb_filename *smb_fname_dst)
 607 {
 608         NTSTATUS status;
 609         int ret = -1;
 610         char *src_xattr_name = NULL;
 611         char *dst_xattr_name = NULL;
 612         bool src_is_stream, dst_is_stream;
 613         ssize_t oret;
 614         ssize_t nret;
 615         struct ea_struct ea;
 616
 617         src_is_stream = is_ntfs_stream_smb_fname(smb_fname_src);
 618         dst_is_stream = is_ntfs_stream_smb_fname(smb_fname_dst);
 619
 620         if (!src_is_stream && !dst_is_stream) {
 621                 return SMB_VFS_NEXT_RENAME(handle, smb_fname_src,
 622                                            smb_fname_dst);
 623         }
 624
 625         /* For now don't allow renames from or to the default stream. */
 626         if (is_ntfs_default_stream_smb_fname(smb_fname_src) ||
 627             is_ntfs_default_stream_smb_fname(smb_fname_dst)) {
 628                 errno = ENOSYS;
 629                 goto done;
 630         }
 631
 632         /* Don't rename if the streams are identical. */
 633         if (strcasecmp_m(smb_fname_src->stream_name,
 634                        smb_fname_dst->stream_name) == 0) {
 635                 goto done;
 636         }
 637
 638         /* Get the xattr names. */
 639         status = streams_xattr_get_name(handle, talloc_tos(),
 640                                         smb_fname_src->stream_name,
 641                                         &src_xattr_name);
 642         if (!NT_STATUS_IS_OK(status)) {
 643                 errno = map_errno_from_nt_status(status);
 644                 goto fail;
 645         }
 646         status = streams_xattr_get_name(handle, talloc_tos(),
 647                                         smb_fname_dst->stream_name,
 648                                         &dst_xattr_name);
 649         if (!NT_STATUS_IS_OK(status)) {
 650                 errno = map_errno_from_nt_status(status);
 651                 goto fail;
 652         }
 653
 654         /* read the old stream */
 655         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 656                               smb_fname_src->base_name, src_xattr_name, &ea);
 657         if (!NT_STATUS_IS_OK(status)) {
 658                 errno = ENOENT;
 659                 goto fail;
 660         }
 661
 662         /* (over)write the new stream */
 663         nret = SMB_VFS_SETXATTR(handle->conn, smb_fname_src->base_name,
 664                                 dst_xattr_name, ea.value.data, ea.value.length,
 665                                 0);
 666         if (nret < 0) {
 667                 if (errno == ENOATTR) {
 668                         errno = ENOENT;
 669                 }
 670                 goto fail;
 671         }
 672
 673         /* remove the old stream */
 674         oret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname_src->base_name,
 675                                    src_xattr_name);
 676         if (oret < 0) {
 677                 if (errno == ENOATTR) {
 678                         errno = ENOENT;
 679                 }
 680                 goto fail;
 681         }
 682
 683  done:
 684         errno = 0;
 685         ret = 0;
 686  fail:
 687         TALLOC_FREE(src_xattr_name);
 688         TALLOC_FREE(dst_xattr_name);
 689         return ret;
 690 }
 691
 692 static NTSTATUS walk_xattr_streams(vfs_handle_struct *handle,
 693                                 files_struct *fsp,
 694                                 const struct smb_filename *smb_fname,
 695                                 bool (*fn)(struct ea_struct *ea,
 696                                         void *private_data),
 697                                 void *private_data)
 698 {
 699         NTSTATUS status;
 700         char **names;
 701         size_t i, num_names;
 702         struct streams_xattr_config *config;
 703
 704         SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
 705                                 return NT_STATUS_UNSUCCESSFUL);
 706
 707         status = get_ea_names_from_file(talloc_tos(),
 708                                 handle->conn,
 709                                 fsp,
 710                                 smb_fname,
 711                                 &names,
 712                                 &num_names);
 713         if (!NT_STATUS_IS_OK(status)) {
 714                 return status;
 715         }
 716
 717         for (i=0; i<num_names; i++) {
 718                 struct ea_struct ea;
 719
 720                 /*
 721                  * We want to check with samba_private_attr_name()
 722                  * whether the xattr name is a private one,
 723                  * unfortunately it flags xattrs that begin with the
 724                  * default streams prefix as private.
 725                  *
 726                  * By only calling samba_private_attr_name() in case
 727                  * the xattr does NOT begin with the default prefix,
 728                  * we know that if it returns 'true' it definitely one
 729                  * of our internal xattr like "user.DOSATTRIB".
 730                  */
 731                 if (strncasecmp_m(names[i], SAMBA_XATTR_DOSSTREAM_PREFIX,
 732                                   strlen(SAMBA_XATTR_DOSSTREAM_PREFIX)) != 0) {
 733                         if (samba_private_attr_name(names[i])) {
 734                                 continue;
 735                         }
 736                 }
 737
 738                 if (strncmp(names[i], config->prefix,
 739                             config->prefix_len) != 0) {
 740                         continue;
 741                 }
 742
 743                 status = get_ea_value(names,
 744                                         handle->conn,
 745                                         fsp,
 746                                         smb_fname->base_name,
 747                                         names[i],
 748                                         &ea);
 749                 if (!NT_STATUS_IS_OK(status)) {
 750                         DEBUG(10, ("Could not get ea %s for file %s: %s\n",
 751                                 names[i],
 752                                 smb_fname->base_name,
 753                                 nt_errstr(status)));
 754                         continue;
 755                 }
 756
 757                 ea.name = talloc_asprintf(
 758                         ea.value.data, ":%s%s",
 759                         names[i] + config->prefix_len,
 760                         config->store_stream_type ? "" : ":$DATA");
 761                 if (ea.name == NULL) {
 762                         DEBUG(0, ("talloc failed\n"));
 763                         continue;
 764                 }
 765
 766                 if (!fn(&ea, private_data)) {
 767                         TALLOC_FREE(ea.value.data);
 768                         return NT_STATUS_OK;
 769                 }
 770
 771                 TALLOC_FREE(ea.value.data);
 772         }
 773
 774         TALLOC_FREE(names);
 775         return NT_STATUS_OK;
 776 }
 777
 778 static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
 779                            struct stream_struct **streams,
 780                            const char *name, off_t size,
 781                            off_t alloc_size)
 782 {
 783         struct stream_struct *tmp;
 784
 785         tmp = talloc_realloc(mem_ctx, *streams, struct stream_struct,
 786                                    (*num_streams)+1);
 787         if (tmp == NULL) {
 788                 return false;
 789         }
 790
 791         tmp[*num_streams].name = talloc_strdup(tmp, name);
 792         if (tmp[*num_streams].name == NULL) {
 793                 return false;
 794         }
 795
 796         tmp[*num_streams].size = size;
 797         tmp[*num_streams].alloc_size = alloc_size;
 798
 799         *streams = tmp;
 800         *num_streams += 1;
 801         return true;
 802 }
 803
 804 struct streaminfo_state {
 805         TALLOC_CTX *mem_ctx;
 806         vfs_handle_struct *handle;
 807         unsigned int num_streams;
 808         struct stream_struct *streams;
 809         NTSTATUS status;
 810 };
 811
 812 static bool collect_one_stream(struct ea_struct *ea, void *private_data)
 813 {
 814         struct streaminfo_state *state =
 815                 (struct streaminfo_state *)private_data;
 816
 817         if (!add_one_stream(state->mem_ctx,
 818                             &state->num_streams, &state->streams,
 819                             ea->name, ea->value.length-1,
 820                             smb_roundup(state->handle->conn,
 821                                         ea->value.length-1))) {
 822                 state->status = NT_STATUS_NO_MEMORY;
 823                 return false;
 824         }
 825
 826         return true;
 827 }
 828
 829 static NTSTATUS streams_xattr_streaminfo(vfs_handle_struct *handle,
 830                                          struct files_struct *fsp,
 831                                          const struct smb_filename *smb_fname,
 832                                          TALLOC_CTX *mem_ctx,
 833                                          unsigned int *pnum_streams,
 834                                          struct stream_struct **pstreams)
 835 {
 836         SMB_STRUCT_STAT sbuf;
 837         int ret;
 838         NTSTATUS status;
 839         struct streaminfo_state state;
 840
 841         if ((fsp != NULL) && (fsp->fh->fd != -1)) {
 842                 ret = SMB_VFS_FSTAT(fsp, &sbuf);
 843         } else {
 844                 ret = vfs_stat_smb_basename(handle->conn,
 845                                 smb_fname,
 846                                 &sbuf);
 847         }
 848
 849         if (ret == -1) {
 850                 return map_nt_error_from_unix(errno);
 851         }
 852
 853         state.streams = *pstreams;
 854         state.num_streams = *pnum_streams;
 855         state.mem_ctx = mem_ctx;
 856         state.handle = handle;
 857         state.status = NT_STATUS_OK;
 858
 859         if (S_ISLNK(sbuf.st_ex_mode)) {
 860                 /*
 861                  * Currently we do't have SMB_VFS_LLISTXATTR
 862                  * inside the VFS which means there's no way
 863                  * to cope with a symlink when lp_posix_pathnames().
 864                  * returns true. For now ignore links.
 865                  * FIXME - by adding SMB_VFS_LLISTXATTR. JRA.
 866                  */
 867                 status = NT_STATUS_OK;
 868         } else {
 869                 status = walk_xattr_streams(handle, fsp, smb_fname,
 870                                     collect_one_stream, &state);
 871         }
 872
 873         if (!NT_STATUS_IS_OK(status)) {
 874                 TALLOC_FREE(state.streams);
 875                 return status;
 876         }
 877
 878         if (!NT_STATUS_IS_OK(state.status)) {
 879                 TALLOC_FREE(state.streams);
 880                 return state.status;
 881         }
 882
 883         *pnum_streams = state.num_streams;
 884         *pstreams = state.streams;
 885
 886         return SMB_VFS_NEXT_STREAMINFO(handle,
 887                         fsp,
 888                         smb_fname,
 889                         mem_ctx,
 890                         pnum_streams,
 891                         pstreams);
 892 }
 893
 894 static uint32_t streams_xattr_fs_capabilities(struct vfs_handle_struct *handle,
 895                         enum timestamp_set_resolution *p_ts_res)
 896 {
 897         return SMB_VFS_NEXT_FS_CAPABILITIES(handle, p_ts_res) | FILE_NAMED_STREAMS;
 898 }
 899
 900 static int streams_xattr_connect(vfs_handle_struct *handle,
 901                                  const char *service, const char *user)
 902 {
 903         struct streams_xattr_config *config;
 904         const char *default_prefix = SAMBA_XATTR_DOSSTREAM_PREFIX;
 905         const char *prefix;
 906         int rc;
 907
 908         rc = SMB_VFS_NEXT_CONNECT(handle, service, user);
 909         if (rc != 0) {
 910                 return rc;
 911         }
 912
 913         config = talloc_zero(handle->conn, struct streams_xattr_config);
 914         if (config == NULL) {
 915                 DEBUG(1, ("talloc_zero() failed\n"));
 916                 errno = ENOMEM;
 917                 return -1;
 918         }
 919
 920         prefix = lp_parm_const_string(SNUM(handle->conn),
 921                                       "streams_xattr", "prefix",
 922                                       default_prefix);
 923         config->prefix = talloc_strdup(config, prefix);
 924         if (config->prefix == NULL) {
 925                 DEBUG(1, ("talloc_strdup() failed\n"));
 926                 errno = ENOMEM;
 927                 return -1;
 928         }
 929         config->prefix_len = strlen(config->prefix);
 930         DEBUG(10, ("streams_xattr using stream prefix: %s\n", config->prefix));
 931
 932         config->store_stream_type = lp_parm_bool(SNUM(handle->conn),
 933                                                  "streams_xattr",
 934                                                  "store_stream_type",
 935                                                  true);
 936
 937         SMB_VFS_HANDLE_SET_DATA(handle, config,
 938                                 NULL, struct stream_xattr_config,
 939                                 return -1);
 940
 941         return 0;
 942 }
 943
 944 static ssize_t streams_xattr_pwrite(vfs_handle_struct *handle,
 945                                     files_struct *fsp, const void *data,
 946                                     size_t n, off_t offset)
 947 {
 948         struct stream_io *sio =
 949                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 950         struct ea_struct ea;
 951         NTSTATUS status;
 952         int ret;
 953
 954         DEBUG(10, ("streams_xattr_pwrite called for %d bytes\n", (int)n));
 955
 956         if (sio == NULL) {
 957                 return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 958         }
 959
 960         if (!streams_xattr_recheck(sio)) {
 961                 return -1;
 962         }
 963
 964         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
 965                               sio->base, sio->xattr_name, &ea);
 966         if (!NT_STATUS_IS_OK(status)) {
 967                 return -1;
 968         }
 969
 970         if ((offset + n) > ea.value.length-1) {
 971                 uint8_t *tmp;
 972
 973                 tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8_t,
 974                                            offset + n + 1);
 975
 976                 if (tmp == NULL) {
 977                         TALLOC_FREE(ea.value.data);
 978                         errno = ENOMEM;
 979                         return -1;
 980                 }
 981                 ea.value.data = tmp;
 982                 ea.value.length = offset + n + 1;
 983                 ea.value.data[offset+n] = 0;
 984         }
 985
 986         memcpy(ea.value.data + offset, data, n);
 987
 988         if (fsp->base_fsp->fh->fd != -1) {
 989                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
 990                                 sio->xattr_name,
 991                                 ea.value.data, ea.value.length, 0);
 992         } else {
 993                 ret = SMB_VFS_SETXATTR(fsp->conn,
 994                                        fsp->base_fsp->fsp_name->base_name,
 995                                 sio->xattr_name,
 996                                 ea.value.data, ea.value.length, 0);
 997         }
 998         TALLOC_FREE(ea.value.data);
 999
1000         if (ret == -1) {
1001                 return -1;
1002         }
1003
1004         return n;
1005 }
1006
1007 static ssize_t streams_xattr_pread(vfs_handle_struct *handle,
1008                                    files_struct *fsp, void *data,
1009                                    size_t n, off_t offset)
1010 {
1011         struct stream_io *sio =
1012                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1013         struct ea_struct ea;
1014         NTSTATUS status;
1015         size_t length, overlap;
1016
1017         DEBUG(10, ("streams_xattr_pread: offset=%d, size=%d\n",
1018                    (int)offset, (int)n));
1019
1020         if (sio == NULL) {
1021                 return SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
1022         }
1023
1024         if (!streams_xattr_recheck(sio)) {
1025                 return -1;
1026         }
1027
1028         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
1029                               sio->base, sio->xattr_name, &ea);
1030         if (!NT_STATUS_IS_OK(status)) {
1031                 return -1;
1032         }
1033
1034         length = ea.value.length-1;
1035
1036         DEBUG(10, ("streams_xattr_pread: get_ea_value returned %d bytes\n",
1037                    (int)length));
1038
1039         /* Attempt to read past EOF. */
1040         if (length <= offset) {
1041                 return 0;
1042         }
1043
1044         overlap = (offset + n) > length ? (length - offset) : n;
1045         memcpy(data, ea.value.data + offset, overlap);
1046
1047         TALLOC_FREE(ea.value.data);
1048         return overlap;
1049 }
1050
1051 static int streams_xattr_ftruncate(struct vfs_handle_struct *handle,
1052                                         struct files_struct *fsp,
1053                                         off_t offset)
1054 {
1055         int ret;
1056         uint8_t *tmp;
1057         struct ea_struct ea;
1058         NTSTATUS status;
1059         struct stream_io *sio =
1060                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1061
1062         DEBUG(10, ("streams_xattr_ftruncate called for file %s offset %.0f\n",
1063                    fsp_str_dbg(fsp), (double)offset));
1064
1065         if (sio == NULL) {
1066                 return SMB_VFS_NEXT_FTRUNCATE(handle, fsp, offset);
1067         }
1068
1069         if (!streams_xattr_recheck(sio)) {
1070                 return -1;
1071         }
1072
1073         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
1074                               sio->base, sio->xattr_name, &ea);
1075         if (!NT_STATUS_IS_OK(status)) {
1076                 return -1;
1077         }
1078
1079         tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8_t,
1080                                    offset + 1);
1081
1082         if (tmp == NULL) {
1083                 TALLOC_FREE(ea.value.data);
1084                 errno = ENOMEM;
1085                 return -1;
1086         }
1087
1088         /* Did we expand ? */
1089         if (ea.value.length < offset + 1) {
1090                 memset(&tmp[ea.value.length], '\0',
1091                         offset + 1 - ea.value.length);
1092         }
1093
1094         ea.value.data = tmp;
1095         ea.value.length = offset + 1;
1096         ea.value.data[offset] = 0;
1097
1098         if (fsp->base_fsp->fh->fd != -1) {
1099                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
1100                                 sio->xattr_name,
1101                                 ea.value.data, ea.value.length, 0);
1102         } else {
1103                 ret = SMB_VFS_SETXATTR(fsp->conn,
1104                                        fsp->base_fsp->fsp_name->base_name,
1105                                 sio->xattr_name,
1106                                 ea.value.data, ea.value.length, 0);
1107         }
1108
1109         TALLOC_FREE(ea.value.data);
1110
1111         if (ret == -1) {
1112                 return -1;
1113         }
1114
1115         return 0;
1116 }
1117
1118 static int streams_xattr_fallocate(struct vfs_handle_struct *handle,
1119                                         struct files_struct *fsp,
1120                                         uint32_t mode,
1121                                         off_t offset,
1122                                         off_t len)
1123 {
1124         struct stream_io *sio =
1125                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1126
1127         DEBUG(10, ("streams_xattr_fallocate called for file %s offset %.0f"
1128                 "len = %.0f\n",
1129                 fsp_str_dbg(fsp), (double)offset, (double)len));
1130
1131         if (sio == NULL) {
1132                 return SMB_VFS_NEXT_FALLOCATE(handle, fsp, mode, offset, len);
1133         }
1134
1135         if (!streams_xattr_recheck(sio)) {
1136                 return -1;
1137         }
1138
1139         /* Let the pwrite code path handle it. */
1140         errno = ENOSYS;
1141         return -1;
1142 }
1143
1144
1145 static struct vfs_fn_pointers vfs_streams_xattr_fns = {
1146         .fs_capabilities_fn = streams_xattr_fs_capabilities,
1147         .connect_fn = streams_xattr_connect,
1148         .open_fn = streams_xattr_open,
1149         .stat_fn = streams_xattr_stat,
1150         .fstat_fn = streams_xattr_fstat,
1151         .lstat_fn = streams_xattr_lstat,
1152         .pread_fn = streams_xattr_pread,
1153         .pwrite_fn = streams_xattr_pwrite,
1154         .unlink_fn = streams_xattr_unlink,
1155         .rename_fn = streams_xattr_rename,
1156         .ftruncate_fn = streams_xattr_ftruncate,
1157         .fallocate_fn = streams_xattr_fallocate,
1158         .streaminfo_fn = streams_xattr_streaminfo,
1159 };
1160
1161 NTSTATUS vfs_streams_xattr_init(void);
1162 NTSTATUS vfs_streams_xattr_init(void)
1163 {
1164         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_xattr",
1165                                 &vfs_streams_xattr_fns);
1166 }