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 #include "lib/util/tevent_unix.h"
  29
  30 #undef DBGC_CLASS
  31 #define DBGC_CLASS DBGC_VFS
  32
  33 struct streams_xattr_config {
  34         const char *prefix;
  35         size_t prefix_len;
  36         bool store_stream_type;
  37 };
  38
  39 struct stream_io {
  40         char *base;
  41         char *xattr_name;
  42         void *fsp_name_ptr;
  43         files_struct *fsp;
  44         vfs_handle_struct *handle;
  45 };
  46
  47 static SMB_INO_T stream_inode(const SMB_STRUCT_STAT *sbuf, const char *sname)
  48 {
  49         MD5_CTX ctx;
  50         unsigned char hash[16];
  51         SMB_INO_T result;
  52         char *upper_sname;
  53
  54         DEBUG(10, ("stream_inode called for %lu/%lu [%s]\n",
  55                    (unsigned long)sbuf->st_ex_dev,
  56                    (unsigned long)sbuf->st_ex_ino, sname));
  57
  58         upper_sname = talloc_strdup_upper(talloc_tos(), sname);
  59         SMB_ASSERT(upper_sname != NULL);
  60
  61         MD5Init(&ctx);
  62         MD5Update(&ctx, (const unsigned char *)&(sbuf->st_ex_dev),
  63                   sizeof(sbuf->st_ex_dev));
  64         MD5Update(&ctx, (const unsigned char *)&(sbuf->st_ex_ino),
  65                   sizeof(sbuf->st_ex_ino));
  66         MD5Update(&ctx, (unsigned char *)upper_sname,
  67                   talloc_get_size(upper_sname)-1);
  68         MD5Final(hash, &ctx);
  69
  70         TALLOC_FREE(upper_sname);
  71
  72         /* Hopefully all the variation is in the lower 4 (or 8) bytes! */
  73         memcpy(&result, hash, sizeof(result));
  74
  75         DEBUG(10, ("stream_inode returns %lu\n", (unsigned long)result));
  76
  77         return result;
  78 }
  79
  80 static ssize_t get_xattr_size(connection_struct *conn,
  81                                 files_struct *fsp,
  82                                 const char *fname,
  83                                 const char *xattr_name)
  84 {
  85         NTSTATUS status;
  86         struct ea_struct ea;
  87         ssize_t result;
  88
  89         status = get_ea_value(talloc_tos(), conn, fsp, fname,
  90                               xattr_name, &ea);
  91
  92         if (!NT_STATUS_IS_OK(status)) {
  93                 return -1;
  94         }
  95
  96         result = ea.value.length-1;
  97         TALLOC_FREE(ea.value.data);
  98         return result;
  99 }
 100
 101 /**
 102  * Given a stream name, populate xattr_name with the xattr name to use for
 103  * accessing the stream.
 104  */
 105 static NTSTATUS streams_xattr_get_name(vfs_handle_struct *handle,
 106                                        TALLOC_CTX *ctx,
 107                                        const char *stream_name,
 108                                        char **xattr_name)
 109 {
 110         char *sname;
 111         char *stype;
 112         struct streams_xattr_config *config;
 113
 114         SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
 115                                 return NT_STATUS_UNSUCCESSFUL);
 116
 117         sname = talloc_strdup(ctx, stream_name + 1);
 118         if (sname == NULL) {
 119                 return NT_STATUS_NO_MEMORY;
 120         }
 121
 122         /*
 123          * With vfs_fruit option "fruit:encoding = native" we're
 124          * already converting stream names that contain illegal NTFS
 125          * characters from their on-the-wire Unicode Private Range
 126          * encoding to their native ASCII representation.
 127          *
 128          * As as result the name of xattrs storing the streams (via
 129          * vfs_streams_xattr) may contain a colon, so we have to use
 130          * strrchr_m() instead of strchr_m() for matching the stream
 131          * type suffix.
 132          *
 133          * In check_path_syntax() we've already ensured the streamname
 134          * we got from the client is valid.
 135          */
 136         stype = strrchr_m(sname, ':');
 137
 138         if (stype) {
 139                 /*
 140                  * We only support one stream type: "$DATA"
 141                  */
 142                 if (strcasecmp_m(stype, ":$DATA") != 0) {
 143                         talloc_free(sname);
 144                         return NT_STATUS_INVALID_PARAMETER;
 145                 }
 146
 147                 /* Split name and type */
 148                 stype[0] = '\0';
 149         }
 150
 151         *xattr_name = talloc_asprintf(ctx, "%s%s%s",
 152                                       config->prefix,
 153                                       sname,
 154                                       config->store_stream_type ? ":$DATA" : "");
 155         if (*xattr_name == NULL) {
 156                 talloc_free(sname);
 157                 return NT_STATUS_NO_MEMORY;
 158         }
 159
 160         DEBUG(10, ("xattr_name: %s, stream_name: %s\n", *xattr_name,
 161                    stream_name));
 162
 163         talloc_free(sname);
 164         return NT_STATUS_OK;
 165 }
 166
 167 static bool streams_xattr_recheck(struct stream_io *sio)
 168 {
 169         NTSTATUS status;
 170         char *xattr_name = NULL;
 171
 172         if (sio->fsp->fsp_name == sio->fsp_name_ptr) {
 173                 return true;
 174         }
 175
 176         if (sio->fsp->fsp_name->stream_name == NULL) {
 177                 /* how can this happen */
 178                 errno = EINVAL;
 179                 return false;
 180         }
 181
 182         status = streams_xattr_get_name(sio->handle, talloc_tos(),
 183                                         sio->fsp->fsp_name->stream_name,
 184                                         &xattr_name);
 185         if (!NT_STATUS_IS_OK(status)) {
 186                 return false;
 187         }
 188
 189         TALLOC_FREE(sio->xattr_name);
 190         TALLOC_FREE(sio->base);
 191         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 192                                         xattr_name);
 193         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 194                                   sio->fsp->fsp_name->base_name);
 195         sio->fsp_name_ptr = sio->fsp->fsp_name;
 196
 197         TALLOC_FREE(xattr_name);
 198
 199         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 200                 return false;
 201         }
 202
 203         return true;
 204 }
 205
 206 /**
 207  * Helper to stat/lstat the base file of an smb_fname.
 208  */
 209 static int streams_xattr_stat_base(vfs_handle_struct *handle,
 210                                    struct smb_filename *smb_fname,
 211                                    bool follow_links)
 212 {
 213         char *tmp_stream_name;
 214         int result;
 215
 216         tmp_stream_name = smb_fname->stream_name;
 217         smb_fname->stream_name = NULL;
 218         if (follow_links) {
 219                 result = SMB_VFS_NEXT_STAT(handle, smb_fname);
 220         } else {
 221                 result = SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 222         }
 223         smb_fname->stream_name = tmp_stream_name;
 224         return result;
 225 }
 226
 227 static int streams_xattr_fstat(vfs_handle_struct *handle, files_struct *fsp,
 228                                SMB_STRUCT_STAT *sbuf)
 229 {
 230         struct smb_filename *smb_fname_base = NULL;
 231         int ret = -1;
 232         struct stream_io *io = (struct stream_io *)
 233                 VFS_FETCH_FSP_EXTENSION(handle, fsp);
 234
 235         DEBUG(10, ("streams_xattr_fstat called for %d\n", fsp->fh->fd));
 236
 237         if (io == NULL || fsp->base_fsp == NULL) {
 238                 return SMB_VFS_NEXT_FSTAT(handle, fsp, sbuf);
 239         }
 240
 241         if (!streams_xattr_recheck(io)) {
 242                 return -1;
 243         }
 244
 245         /* Create an smb_filename with stream_name == NULL. */
 246         smb_fname_base = synthetic_smb_fname(talloc_tos(),
 247                                         io->base,
 248                                         NULL,
 249                                         NULL,
 250                                         fsp->fsp_name->flags);
 251         if (smb_fname_base == NULL) {
 252                 errno = ENOMEM;
 253                 return -1;
 254         }
 255
 256         if (smb_fname_base->flags & SMB_FILENAME_POSIX_PATH) {
 257                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname_base);
 258         } else {
 259                 ret = SMB_VFS_STAT(handle->conn, smb_fname_base);
 260         }
 261         *sbuf = smb_fname_base->st;
 262         TALLOC_FREE(smb_fname_base);
 263
 264         if (ret == -1) {
 265                 return -1;
 266         }
 267
 268         sbuf->st_ex_size = get_xattr_size(handle->conn, fsp,
 269                                         io->base, io->xattr_name);
 270         if (sbuf->st_ex_size == -1) {
 271                 return -1;
 272         }
 273
 274         DEBUG(10, ("sbuf->st_ex_size = %d\n", (int)sbuf->st_ex_size));
 275
 276         sbuf->st_ex_ino = stream_inode(sbuf, io->xattr_name);
 277         sbuf->st_ex_mode &= ~S_IFMT;
 278         sbuf->st_ex_mode |= S_IFREG;
 279         sbuf->st_ex_blocks = sbuf->st_ex_size / STAT_ST_BLOCKSIZE + 1;
 280
 281         return 0;
 282 }
 283
 284 static int streams_xattr_stat(vfs_handle_struct *handle,
 285                               struct smb_filename *smb_fname)
 286 {
 287         NTSTATUS status;
 288         int result = -1;
 289         char *xattr_name = NULL;
 290
 291         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 292                 return SMB_VFS_NEXT_STAT(handle, smb_fname);
 293         }
 294
 295         /* Note if lp_posix_paths() is true, we can never
 296          * get here as is_ntfs_stream_smb_fname() is
 297          * always false. So we never need worry about
 298          * not following links here. */
 299
 300         /* If the default stream is requested, just stat the base file. */
 301         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 302                 return streams_xattr_stat_base(handle, smb_fname, true);
 303         }
 304
 305         /* Populate the stat struct with info from the base file. */
 306         if (streams_xattr_stat_base(handle, smb_fname, true) == -1) {
 307                 return -1;
 308         }
 309
 310         /* Derive the xattr name to lookup. */
 311         status = streams_xattr_get_name(handle, talloc_tos(),
 312                                         smb_fname->stream_name, &xattr_name);
 313         if (!NT_STATUS_IS_OK(status)) {
 314                 errno = map_errno_from_nt_status(status);
 315                 return -1;
 316         }
 317
 318         /* Augment the base file's stat information before returning. */
 319         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 320                                                   smb_fname->base_name,
 321                                                   xattr_name);
 322         if (smb_fname->st.st_ex_size == -1) {
 323                 errno = ENOENT;
 324                 result = -1;
 325                 goto fail;
 326         }
 327
 328         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 329         smb_fname->st.st_ex_mode &= ~S_IFMT;
 330         smb_fname->st.st_ex_mode |= S_IFREG;
 331         smb_fname->st.st_ex_blocks =
 332             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 333
 334         result = 0;
 335  fail:
 336         TALLOC_FREE(xattr_name);
 337         return result;
 338 }
 339
 340 static int streams_xattr_lstat(vfs_handle_struct *handle,
 341                                struct smb_filename *smb_fname)
 342 {
 343         NTSTATUS status;
 344         int result = -1;
 345         char *xattr_name = NULL;
 346
 347         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 348                 return SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 349         }
 350
 351         /* If the default stream is requested, just stat the base file. */
 352         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 353                 return streams_xattr_stat_base(handle, smb_fname, false);
 354         }
 355
 356         /* Populate the stat struct with info from the base file. */
 357         if (streams_xattr_stat_base(handle, smb_fname, false) == -1) {
 358                 return -1;
 359         }
 360
 361         /* Derive the xattr name to lookup. */
 362         status = streams_xattr_get_name(handle, talloc_tos(),
 363                                         smb_fname->stream_name, &xattr_name);
 364         if (!NT_STATUS_IS_OK(status)) {
 365                 errno = map_errno_from_nt_status(status);
 366                 return -1;
 367         }
 368
 369         /* Augment the base file's stat information before returning. */
 370         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 371                                                   smb_fname->base_name,
 372                                                   xattr_name);
 373         if (smb_fname->st.st_ex_size == -1) {
 374                 errno = ENOENT;
 375                 result = -1;
 376                 goto fail;
 377         }
 378
 379         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 380         smb_fname->st.st_ex_mode &= ~S_IFMT;
 381         smb_fname->st.st_ex_mode |= S_IFREG;
 382         smb_fname->st.st_ex_blocks =
 383             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 384
 385         result = 0;
 386
 387  fail:
 388         TALLOC_FREE(xattr_name);
 389         return result;
 390 }
 391
 392 static int streams_xattr_open(vfs_handle_struct *handle,
 393                               struct smb_filename *smb_fname,
 394                               files_struct *fsp, int flags, mode_t mode)
 395 {
 396         NTSTATUS status;
 397         struct smb_filename *smb_fname_base = NULL;
 398         struct stream_io *sio;
 399         struct ea_struct ea;
 400         char *xattr_name = NULL;
 401         int baseflags;
 402         int hostfd = -1;
 403         int ret;
 404
 405         DEBUG(10, ("streams_xattr_open called for %s with flags 0x%x\n",
 406                    smb_fname_str_dbg(smb_fname), flags));
 407
 408         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 409                 return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 410         }
 411
 412         /* If the default stream is requested, just open the base file. */
 413         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 414                 char *tmp_stream_name;
 415
 416                 tmp_stream_name = smb_fname->stream_name;
 417                 smb_fname->stream_name = NULL;
 418
 419                 ret = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 420
 421                 smb_fname->stream_name = tmp_stream_name;
 422
 423                 return ret;
 424         }
 425
 426         status = streams_xattr_get_name(handle, talloc_tos(),
 427                                         smb_fname->stream_name, &xattr_name);
 428         if (!NT_STATUS_IS_OK(status)) {
 429                 errno = map_errno_from_nt_status(status);
 430                 goto fail;
 431         }
 432
 433         /* Create an smb_filename with stream_name == NULL. */
 434         smb_fname_base = synthetic_smb_fname(talloc_tos(),
 435                                 smb_fname->base_name,
 436                                 NULL,
 437                                 NULL,
 438                                 smb_fname->flags);
 439         if (smb_fname_base == NULL) {
 440                 errno = ENOMEM;
 441                 goto fail;
 442         }
 443
 444         /*
 445          * We use baseflags to turn off nasty side-effects when opening the
 446          * underlying file.
 447          */
 448         baseflags = flags;
 449         baseflags &= ~O_TRUNC;
 450         baseflags &= ~O_EXCL;
 451         baseflags &= ~O_CREAT;
 452
 453         hostfd = SMB_VFS_NEXT_OPEN(handle, smb_fname_base, fsp,
 454                                    baseflags, mode);
 455
 456         /* It is legit to open a stream on a directory, but the base
 457          * fd has to be read-only.
 458          */
 459         if ((hostfd == -1) && (errno == EISDIR)) {
 460                 baseflags &= ~O_ACCMODE;
 461                 baseflags |= O_RDONLY;
 462                 hostfd = SMB_VFS_NEXT_OPEN(handle, smb_fname_base, fsp, baseflags,
 463                                            mode);
 464         }
 465
 466         TALLOC_FREE(smb_fname_base);
 467
 468         if (hostfd == -1) {
 469                 goto fail;
 470         }
 471
 472         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 473                               smb_fname->base_name, xattr_name, &ea);
 474
 475         DEBUG(10, ("get_ea_value returned %s\n", nt_errstr(status)));
 476
 477         if (!NT_STATUS_IS_OK(status)
 478             && !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 479                 /*
 480                  * The base file is not there. This is an error even if we got
 481                  * O_CREAT, the higher levels should have created the base
 482                  * file for us.
 483                  */
 484                 DEBUG(10, ("streams_xattr_open: base file %s not around, "
 485                            "returning ENOENT\n", smb_fname->base_name));
 486                 errno = ENOENT;
 487                 goto fail;
 488         }
 489
 490         if ((!NT_STATUS_IS_OK(status) && (flags & O_CREAT)) ||
 491             (flags & O_TRUNC)) {
 492                 /*
 493                  * The attribute does not exist or needs to be truncated
 494                  */
 495
 496                 /*
 497                  * Darn, xattrs need at least 1 byte
 498                  */
 499                 char null = '\0';
 500
 501                 DEBUG(10, ("creating or truncating attribute %s on file %s\n",
 502                            xattr_name, smb_fname->base_name));
 503
 504                 fsp->fh->fd = hostfd;
 505                 ret = SMB_VFS_FSETXATTR(fsp, xattr_name,
 506                                         &null, sizeof(null),
 507                                         flags & O_EXCL ? XATTR_CREATE : 0);
 508                 fsp->fh->fd = -1;
 509                 if (ret != 0) {
 510                         goto fail;
 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         /*
 525          * so->base needs to be a copy of fsp->fsp_name->base_name,
 526          * making it identical to streams_xattr_recheck(). If the
 527          * open is changing directories, fsp->fsp_name->base_name
 528          * will be the full path from the share root, whilst
 529          * smb_fname will be relative to the $cwd.
 530          */
 531         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 532                                   fsp->fsp_name->base_name);
 533         sio->fsp_name_ptr = fsp->fsp_name;
 534         sio->handle = handle;
 535         sio->fsp = fsp;
 536
 537         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 538                 errno = ENOMEM;
 539                 goto fail;
 540         }
 541
 542         return hostfd;
 543
 544  fail:
 545         if (hostfd >= 0) {
 546                 /*
 547                  * BUGBUGBUG -- we would need to call fd_close_posix here, but
 548                  * we don't have a full fsp yet
 549                  */
 550                 fsp->fh->fd = hostfd;
 551                 SMB_VFS_NEXT_CLOSE(handle, fsp);
 552         }
 553
 554         return -1;
 555 }
 556
 557 static int streams_xattr_unlink(vfs_handle_struct *handle,
 558                                 const struct smb_filename *smb_fname)
 559 {
 560         NTSTATUS status;
 561         int ret = -1;
 562         char *xattr_name = NULL;
 563
 564         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 565                 return SMB_VFS_NEXT_UNLINK(handle, smb_fname);
 566         }
 567
 568         /* If the default stream is requested, just open the base file. */
 569         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 570                 struct smb_filename *smb_fname_base = NULL;
 571
 572                 smb_fname_base = cp_smb_filename(talloc_tos(), smb_fname);
 573                 if (smb_fname_base == NULL) {
 574                         errno = ENOMEM;
 575                         return -1;
 576                 }
 577
 578                 ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_base);
 579
 580                 TALLOC_FREE(smb_fname_base);
 581                 return ret;
 582         }
 583
 584         status = streams_xattr_get_name(handle, talloc_tos(),
 585                                         smb_fname->stream_name, &xattr_name);
 586         if (!NT_STATUS_IS_OK(status)) {
 587                 errno = map_errno_from_nt_status(status);
 588                 goto fail;
 589         }
 590
 591         ret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname, xattr_name);
 592
 593         if ((ret == -1) && (errno == ENOATTR)) {
 594                 errno = ENOENT;
 595                 goto fail;
 596         }
 597
 598         ret = 0;
 599
 600  fail:
 601         TALLOC_FREE(xattr_name);
 602         return ret;
 603 }
 604
 605 static int streams_xattr_rename(vfs_handle_struct *handle,
 606                                 const struct smb_filename *smb_fname_src,
 607                                 const struct smb_filename *smb_fname_dst)
 608 {
 609         NTSTATUS status;
 610         int ret = -1;
 611         char *src_xattr_name = NULL;
 612         char *dst_xattr_name = NULL;
 613         bool src_is_stream, dst_is_stream;
 614         ssize_t oret;
 615         ssize_t nret;
 616         struct ea_struct ea;
 617
 618         src_is_stream = is_ntfs_stream_smb_fname(smb_fname_src);
 619         dst_is_stream = is_ntfs_stream_smb_fname(smb_fname_dst);
 620
 621         if (!src_is_stream && !dst_is_stream) {
 622                 return SMB_VFS_NEXT_RENAME(handle, smb_fname_src,
 623                                            smb_fname_dst);
 624         }
 625
 626         /* For now don't allow renames from or to the default stream. */
 627         if (is_ntfs_default_stream_smb_fname(smb_fname_src) ||
 628             is_ntfs_default_stream_smb_fname(smb_fname_dst)) {
 629                 errno = ENOSYS;
 630                 goto done;
 631         }
 632
 633         /* Don't rename if the streams are identical. */
 634         if (strcasecmp_m(smb_fname_src->stream_name,
 635                        smb_fname_dst->stream_name) == 0) {
 636                 goto done;
 637         }
 638
 639         /* Get the xattr names. */
 640         status = streams_xattr_get_name(handle, talloc_tos(),
 641                                         smb_fname_src->stream_name,
 642                                         &src_xattr_name);
 643         if (!NT_STATUS_IS_OK(status)) {
 644                 errno = map_errno_from_nt_status(status);
 645                 goto fail;
 646         }
 647         status = streams_xattr_get_name(handle, talloc_tos(),
 648                                         smb_fname_dst->stream_name,
 649                                         &dst_xattr_name);
 650         if (!NT_STATUS_IS_OK(status)) {
 651                 errno = map_errno_from_nt_status(status);
 652                 goto fail;
 653         }
 654
 655         /* read the old stream */
 656         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 657                               smb_fname_src->base_name, src_xattr_name, &ea);
 658         if (!NT_STATUS_IS_OK(status)) {
 659                 errno = ENOENT;
 660                 goto fail;
 661         }
 662
 663         /* (over)write the new stream */
 664         nret = SMB_VFS_SETXATTR(handle->conn, smb_fname_src->base_name,
 665                                 dst_xattr_name, ea.value.data, ea.value.length,
 666                                 0);
 667         if (nret < 0) {
 668                 if (errno == ENOATTR) {
 669                         errno = ENOENT;
 670                 }
 671                 goto fail;
 672         }
 673
 674         /* remove the old stream */
 675         oret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname_src,
 676                                    src_xattr_name);
 677         if (oret < 0) {
 678                 if (errno == ENOATTR) {
 679                         errno = ENOENT;
 680                 }
 681                 goto fail;
 682         }
 683
 684  done:
 685         errno = 0;
 686         ret = 0;
 687  fail:
 688         TALLOC_FREE(src_xattr_name);
 689         TALLOC_FREE(dst_xattr_name);
 690         return ret;
 691 }
 692
 693 static NTSTATUS walk_xattr_streams(vfs_handle_struct *handle,
 694                                 files_struct *fsp,
 695                                 const struct smb_filename *smb_fname,
 696                                 bool (*fn)(struct ea_struct *ea,
 697                                         void *private_data),
 698                                 void *private_data)
 699 {
 700         NTSTATUS status;
 701         char **names;
 702         size_t i, num_names;
 703         struct streams_xattr_config *config;
 704
 705         SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
 706                                 return NT_STATUS_UNSUCCESSFUL);
 707
 708         status = get_ea_names_from_file(talloc_tos(),
 709                                 handle->conn,
 710                                 fsp,
 711                                 smb_fname,
 712                                 &names,
 713                                 &num_names);
 714         if (!NT_STATUS_IS_OK(status)) {
 715                 return status;
 716         }
 717
 718         for (i=0; i<num_names; i++) {
 719                 struct ea_struct ea;
 720
 721                 /*
 722                  * We want to check with samba_private_attr_name()
 723                  * whether the xattr name is a private one,
 724                  * unfortunately it flags xattrs that begin with the
 725                  * default streams prefix as private.
 726                  *
 727                  * By only calling samba_private_attr_name() in case
 728                  * the xattr does NOT begin with the default prefix,
 729                  * we know that if it returns 'true' it definitely one
 730                  * of our internal xattr like "user.DOSATTRIB".
 731                  */
 732                 if (strncasecmp_m(names[i], SAMBA_XATTR_DOSSTREAM_PREFIX,
 733                                   strlen(SAMBA_XATTR_DOSSTREAM_PREFIX)) != 0) {
 734                         if (samba_private_attr_name(names[i])) {
 735                                 continue;
 736                         }
 737                 }
 738
 739                 if (strncmp(names[i], config->prefix,
 740                             config->prefix_len) != 0) {
 741                         continue;
 742                 }
 743
 744                 status = get_ea_value(names,
 745                                         handle->conn,
 746                                         fsp,
 747                                         smb_fname->base_name,
 748                                         names[i],
 749                                         &ea);
 750                 if (!NT_STATUS_IS_OK(status)) {
 751                         DEBUG(10, ("Could not get ea %s for file %s: %s\n",
 752                                 names[i],
 753                                 smb_fname->base_name,
 754                                 nt_errstr(status)));
 755                         continue;
 756                 }
 757
 758                 ea.name = talloc_asprintf(
 759                         ea.value.data, ":%s%s",
 760                         names[i] + config->prefix_len,
 761                         config->store_stream_type ? "" : ":$DATA");
 762                 if (ea.name == NULL) {
 763                         DEBUG(0, ("talloc failed\n"));
 764                         continue;
 765                 }
 766
 767                 if (!fn(&ea, private_data)) {
 768                         TALLOC_FREE(ea.value.data);
 769                         return NT_STATUS_OK;
 770                 }
 771
 772                 TALLOC_FREE(ea.value.data);
 773         }
 774
 775         TALLOC_FREE(names);
 776         return NT_STATUS_OK;
 777 }
 778
 779 static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
 780                            struct stream_struct **streams,
 781                            const char *name, off_t size,
 782                            off_t alloc_size)
 783 {
 784         struct stream_struct *tmp;
 785
 786         tmp = talloc_realloc(mem_ctx, *streams, struct stream_struct,
 787                                    (*num_streams)+1);
 788         if (tmp == NULL) {
 789                 return false;
 790         }
 791
 792         tmp[*num_streams].name = talloc_strdup(tmp, name);
 793         if (tmp[*num_streams].name == NULL) {
 794                 return false;
 795         }
 796
 797         tmp[*num_streams].size = size;
 798         tmp[*num_streams].alloc_size = alloc_size;
 799
 800         *streams = tmp;
 801         *num_streams += 1;
 802         return true;
 803 }
 804
 805 struct streaminfo_state {
 806         TALLOC_CTX *mem_ctx;
 807         vfs_handle_struct *handle;
 808         unsigned int num_streams;
 809         struct stream_struct *streams;
 810         NTSTATUS status;
 811 };
 812
 813 static bool collect_one_stream(struct ea_struct *ea, void *private_data)
 814 {
 815         struct streaminfo_state *state =
 816                 (struct streaminfo_state *)private_data;
 817
 818         if (!add_one_stream(state->mem_ctx,
 819                             &state->num_streams, &state->streams,
 820                             ea->name, ea->value.length-1,
 821                             smb_roundup(state->handle->conn,
 822                                         ea->value.length-1))) {
 823                 state->status = NT_STATUS_NO_MEMORY;
 824                 return false;
 825         }
 826
 827         return true;
 828 }
 829
 830 static NTSTATUS streams_xattr_streaminfo(vfs_handle_struct *handle,
 831                                          struct files_struct *fsp,
 832                                          const struct smb_filename *smb_fname,
 833                                          TALLOC_CTX *mem_ctx,
 834                                          unsigned int *pnum_streams,
 835                                          struct stream_struct **pstreams)
 836 {
 837         SMB_STRUCT_STAT sbuf;
 838         int ret;
 839         NTSTATUS status;
 840         struct streaminfo_state state;
 841
 842         if ((fsp != NULL) && (fsp->fh->fd != -1)) {
 843                 ret = SMB_VFS_FSTAT(fsp, &sbuf);
 844         } else {
 845                 ret = vfs_stat_smb_basename(handle->conn,
 846                                 smb_fname,
 847                                 &sbuf);
 848         }
 849
 850         if (ret == -1) {
 851                 return map_nt_error_from_unix(errno);
 852         }
 853
 854         state.streams = *pstreams;
 855         state.num_streams = *pnum_streams;
 856         state.mem_ctx = mem_ctx;
 857         state.handle = handle;
 858         state.status = NT_STATUS_OK;
 859
 860         if (S_ISLNK(sbuf.st_ex_mode)) {
 861                 /*
 862                  * Currently we do't have SMB_VFS_LLISTXATTR
 863                  * inside the VFS which means there's no way
 864                  * to cope with a symlink when lp_posix_pathnames().
 865                  * returns true. For now ignore links.
 866                  * FIXME - by adding SMB_VFS_LLISTXATTR. JRA.
 867                  */
 868                 status = NT_STATUS_OK;
 869         } else {
 870                 status = walk_xattr_streams(handle, fsp, smb_fname,
 871                                     collect_one_stream, &state);
 872         }
 873
 874         if (!NT_STATUS_IS_OK(status)) {
 875                 TALLOC_FREE(state.streams);
 876                 return status;
 877         }
 878
 879         if (!NT_STATUS_IS_OK(state.status)) {
 880                 TALLOC_FREE(state.streams);
 881                 return state.status;
 882         }
 883
 884         *pnum_streams = state.num_streams;
 885         *pstreams = state.streams;
 886
 887         return SMB_VFS_NEXT_STREAMINFO(handle,
 888                         fsp,
 889                         smb_fname,
 890                         mem_ctx,
 891                         pnum_streams,
 892                         pstreams);
 893 }
 894
 895 static uint32_t streams_xattr_fs_capabilities(struct vfs_handle_struct *handle,
 896                         enum timestamp_set_resolution *p_ts_res)
 897 {
 898         return SMB_VFS_NEXT_FS_CAPABILITIES(handle, p_ts_res) | FILE_NAMED_STREAMS;
 899 }
 900
 901 static int streams_xattr_connect(vfs_handle_struct *handle,
 902                                  const char *service, const char *user)
 903 {
 904         struct streams_xattr_config *config;
 905         const char *default_prefix = SAMBA_XATTR_DOSSTREAM_PREFIX;
 906         const char *prefix;
 907         int rc;
 908
 909         rc = SMB_VFS_NEXT_CONNECT(handle, service, user);
 910         if (rc != 0) {
 911                 return rc;
 912         }
 913
 914         config = talloc_zero(handle->conn, struct streams_xattr_config);
 915         if (config == NULL) {
 916                 DEBUG(1, ("talloc_zero() failed\n"));
 917                 errno = ENOMEM;
 918                 return -1;
 919         }
 920
 921         prefix = lp_parm_const_string(SNUM(handle->conn),
 922                                       "streams_xattr", "prefix",
 923                                       default_prefix);
 924         config->prefix = talloc_strdup(config, prefix);
 925         if (config->prefix == NULL) {
 926                 DEBUG(1, ("talloc_strdup() failed\n"));
 927                 errno = ENOMEM;
 928                 return -1;
 929         }
 930         config->prefix_len = strlen(config->prefix);
 931         DEBUG(10, ("streams_xattr using stream prefix: %s\n", config->prefix));
 932
 933         config->store_stream_type = lp_parm_bool(SNUM(handle->conn),
 934                                                  "streams_xattr",
 935                                                  "store_stream_type",
 936                                                  true);
 937
 938         SMB_VFS_HANDLE_SET_DATA(handle, config,
 939                                 NULL, struct stream_xattr_config,
 940                                 return -1);
 941
 942         return 0;
 943 }
 944
 945 static ssize_t streams_xattr_pwrite(vfs_handle_struct *handle,
 946                                     files_struct *fsp, const void *data,
 947                                     size_t n, off_t offset)
 948 {
 949         struct stream_io *sio =
 950                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 951         struct ea_struct ea;
 952         NTSTATUS status;
 953         int ret;
 954
 955         DEBUG(10, ("streams_xattr_pwrite called for %d bytes\n", (int)n));
 956
 957         if (sio == NULL) {
 958                 return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 959         }
 960
 961         if (!streams_xattr_recheck(sio)) {
 962                 return -1;
 963         }
 964
 965         status = get_ea_value(talloc_tos(), handle->conn, fsp,
 966                               sio->base, sio->xattr_name, &ea);
 967         if (!NT_STATUS_IS_OK(status)) {
 968                 return -1;
 969         }
 970
 971         if ((offset + n) > ea.value.length-1) {
 972                 uint8_t *tmp;
 973
 974                 tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8_t,
 975                                            offset + n + 1);
 976
 977                 if (tmp == NULL) {
 978                         TALLOC_FREE(ea.value.data);
 979                         errno = ENOMEM;
 980                         return -1;
 981                 }
 982                 ea.value.data = tmp;
 983                 ea.value.length = offset + n + 1;
 984                 ea.value.data[offset+n] = 0;
 985         }
 986
 987         memcpy(ea.value.data + offset, data, n);
 988
 989         if (fsp->fh->fd != -1) {
 990                 ret = SMB_VFS_FSETXATTR(fsp,
 991                                 sio->xattr_name,
 992                                 ea.value.data, ea.value.length, 0);
 993         } else {
 994                 ret = SMB_VFS_SETXATTR(fsp->conn,
 995                                        fsp->fsp_name->base_name,
 996                                 sio->xattr_name,
 997                                 ea.value.data, ea.value.length, 0);
 998         }
 999         TALLOC_FREE(ea.value.data);
1000
1001         if (ret == -1) {
1002                 return -1;
1003         }
1004
1005         return n;
1006 }
1007
1008 static ssize_t streams_xattr_pread(vfs_handle_struct *handle,
1009                                    files_struct *fsp, void *data,
1010                                    size_t n, off_t offset)
1011 {
1012         struct stream_io *sio =
1013                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1014         struct ea_struct ea;
1015         NTSTATUS status;
1016         size_t length, overlap;
1017
1018         DEBUG(10, ("streams_xattr_pread: offset=%d, size=%d\n",
1019                    (int)offset, (int)n));
1020
1021         if (sio == NULL) {
1022                 return SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
1023         }
1024
1025         if (!streams_xattr_recheck(sio)) {
1026                 return -1;
1027         }
1028
1029         status = get_ea_value(talloc_tos(), handle->conn, fsp,
1030                               sio->base, sio->xattr_name, &ea);
1031         if (!NT_STATUS_IS_OK(status)) {
1032                 return -1;
1033         }
1034
1035         length = ea.value.length-1;
1036
1037         DEBUG(10, ("streams_xattr_pread: get_ea_value returned %d bytes\n",
1038                    (int)length));
1039
1040         /* Attempt to read past EOF. */
1041         if (length <= offset) {
1042                 return 0;
1043         }
1044
1045         overlap = (offset + n) > length ? (length - offset) : n;
1046         memcpy(data, ea.value.data + offset, overlap);
1047
1048         TALLOC_FREE(ea.value.data);
1049         return overlap;
1050 }
1051
1052 struct streams_xattr_pread_state {
1053         ssize_t nread;
1054         struct vfs_aio_state vfs_aio_state;
1055 };
1056
1057 static void streams_xattr_pread_done(struct tevent_req *subreq);
1058
1059 static struct tevent_req *streams_xattr_pread_send(
1060         struct vfs_handle_struct *handle,
1061         TALLOC_CTX *mem_ctx,
1062         struct tevent_context *ev,
1063         struct files_struct *fsp,
1064         void *data,
1065         size_t n, off_t offset)
1066 {
1067         struct tevent_req *req = NULL;
1068         struct tevent_req *subreq = NULL;
1069         struct streams_xattr_pread_state *state = NULL;
1070         struct stream_io *sio =
1071                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1072
1073         req = tevent_req_create(mem_ctx, &state,
1074                                 struct streams_xattr_pread_state);
1075         if (req == NULL) {
1076                 return NULL;
1077         }
1078
1079         if (sio == NULL) {
1080                 subreq = SMB_VFS_NEXT_PREAD_SEND(state, ev, handle, fsp,
1081                                                  data, n, offset);
1082                 if (tevent_req_nomem(req, subreq)) {
1083                         return tevent_req_post(req, ev);
1084                 }
1085                 tevent_req_set_callback(subreq, streams_xattr_pread_done, req);
1086                 return req;
1087         }
1088
1089         state->nread = SMB_VFS_PREAD(fsp, data, n, offset);
1090         if (state->nread != n) {
1091                 if (state->nread != -1) {
1092                         errno = EIO;
1093                 }
1094                 tevent_req_error(req, errno);
1095                 return tevent_req_post(req, ev);
1096         }
1097
1098         tevent_req_done(req);
1099         return tevent_req_post(req, ev);
1100 }
1101
1102 static void streams_xattr_pread_done(struct tevent_req *subreq)
1103 {
1104         struct tevent_req *req = tevent_req_callback_data(
1105                 subreq, struct tevent_req);
1106         struct streams_xattr_pread_state *state = tevent_req_data(
1107                 req, struct streams_xattr_pread_state);
1108
1109         state->nread = SMB_VFS_PREAD_RECV(subreq, &state->vfs_aio_state);
1110         TALLOC_FREE(subreq);
1111
1112         if (tevent_req_error(req, state->vfs_aio_state.error)) {
1113                 return;
1114         }
1115         tevent_req_done(req);
1116 }
1117
1118 static ssize_t streams_xattr_pread_recv(struct tevent_req *req,
1119                                         struct vfs_aio_state *vfs_aio_state)
1120 {
1121         struct streams_xattr_pread_state *state = tevent_req_data(
1122                 req, struct streams_xattr_pread_state);
1123
1124         if (tevent_req_is_unix_error(req, &vfs_aio_state->error)) {
1125                 return -1;
1126         }
1127
1128         *vfs_aio_state = state->vfs_aio_state;
1129         return state->nread;
1130 }
1131
1132 struct streams_xattr_pwrite_state {
1133         ssize_t nwritten;
1134         struct vfs_aio_state vfs_aio_state;
1135 };
1136
1137 static void streams_xattr_pwrite_done(struct tevent_req *subreq);
1138
1139 static struct tevent_req *streams_xattr_pwrite_send(
1140         struct vfs_handle_struct *handle,
1141         TALLOC_CTX *mem_ctx,
1142         struct tevent_context *ev,
1143         struct files_struct *fsp,
1144         const void *data,
1145         size_t n, off_t offset)
1146 {
1147         struct tevent_req *req = NULL;
1148         struct tevent_req *subreq = NULL;
1149         struct streams_xattr_pwrite_state *state = NULL;
1150         struct stream_io *sio =
1151                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1152
1153         req = tevent_req_create(mem_ctx, &state,
1154                                 struct streams_xattr_pwrite_state);
1155         if (req == NULL) {
1156                 return NULL;
1157         }
1158
1159         if (sio == NULL) {
1160                 subreq = SMB_VFS_NEXT_PWRITE_SEND(state, ev, handle, fsp,
1161                                                   data, n, offset);
1162                 if (tevent_req_nomem(req, subreq)) {
1163                         return tevent_req_post(req, ev);
1164                 }
1165                 tevent_req_set_callback(subreq, streams_xattr_pwrite_done, req);
1166                 return req;
1167         }
1168
1169         state->nwritten = SMB_VFS_PWRITE(fsp, data, n, offset);
1170         if (state->nwritten != n) {
1171                 if (state->nwritten != -1) {
1172                         errno = EIO;
1173                 }
1174                 tevent_req_error(req, errno);
1175                 return tevent_req_post(req, ev);
1176         }
1177
1178         tevent_req_done(req);
1179         return tevent_req_post(req, ev);
1180 }
1181
1182 static void streams_xattr_pwrite_done(struct tevent_req *subreq)
1183 {
1184         struct tevent_req *req = tevent_req_callback_data(
1185                 subreq, struct tevent_req);
1186         struct streams_xattr_pwrite_state *state = tevent_req_data(
1187                 req, struct streams_xattr_pwrite_state);
1188
1189         state->nwritten = SMB_VFS_PWRITE_RECV(subreq, &state->vfs_aio_state);
1190         TALLOC_FREE(subreq);
1191
1192         if (tevent_req_error(req, state->vfs_aio_state.error)) {
1193                 return;
1194         }
1195         tevent_req_done(req);
1196 }
1197
1198 static ssize_t streams_xattr_pwrite_recv(struct tevent_req *req,
1199                                          struct vfs_aio_state *vfs_aio_state)
1200 {
1201         struct streams_xattr_pwrite_state *state = tevent_req_data(
1202                 req, struct streams_xattr_pwrite_state);
1203
1204         if (tevent_req_is_unix_error(req, &vfs_aio_state->error)) {
1205                 return -1;
1206         }
1207
1208         *vfs_aio_state = state->vfs_aio_state;
1209         return state->nwritten;
1210 }
1211
1212 static int streams_xattr_ftruncate(struct vfs_handle_struct *handle,
1213                                         struct files_struct *fsp,
1214                                         off_t offset)
1215 {
1216         int ret;
1217         uint8_t *tmp;
1218         struct ea_struct ea;
1219         NTSTATUS status;
1220         struct stream_io *sio =
1221                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1222
1223         DEBUG(10, ("streams_xattr_ftruncate called for file %s offset %.0f\n",
1224                    fsp_str_dbg(fsp), (double)offset));
1225
1226         if (sio == NULL) {
1227                 return SMB_VFS_NEXT_FTRUNCATE(handle, fsp, offset);
1228         }
1229
1230         if (!streams_xattr_recheck(sio)) {
1231                 return -1;
1232         }
1233
1234         status = get_ea_value(talloc_tos(), handle->conn, fsp,
1235                               sio->base, sio->xattr_name, &ea);
1236         if (!NT_STATUS_IS_OK(status)) {
1237                 return -1;
1238         }
1239
1240         tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8_t,
1241                                    offset + 1);
1242
1243         if (tmp == NULL) {
1244                 TALLOC_FREE(ea.value.data);
1245                 errno = ENOMEM;
1246                 return -1;
1247         }
1248
1249         /* Did we expand ? */
1250         if (ea.value.length < offset + 1) {
1251                 memset(&tmp[ea.value.length], '\0',
1252                         offset + 1 - ea.value.length);
1253         }
1254
1255         ea.value.data = tmp;
1256         ea.value.length = offset + 1;
1257         ea.value.data[offset] = 0;
1258
1259         if (fsp->fh->fd != -1) {
1260                 ret = SMB_VFS_FSETXATTR(fsp,
1261                                 sio->xattr_name,
1262                                 ea.value.data, ea.value.length, 0);
1263         } else {
1264                 ret = SMB_VFS_SETXATTR(fsp->conn,
1265                                 fsp->fsp_name->base_name,
1266                                 sio->xattr_name,
1267                                 ea.value.data, ea.value.length, 0);
1268         }
1269
1270         TALLOC_FREE(ea.value.data);
1271
1272         if (ret == -1) {
1273                 return -1;
1274         }
1275
1276         return 0;
1277 }
1278
1279 static int streams_xattr_fallocate(struct vfs_handle_struct *handle,
1280                                         struct files_struct *fsp,
1281                                         uint32_t mode,
1282                                         off_t offset,
1283                                         off_t len)
1284 {
1285         struct stream_io *sio =
1286                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1287
1288         DEBUG(10, ("streams_xattr_fallocate called for file %s offset %.0f"
1289                 "len = %.0f\n",
1290                 fsp_str_dbg(fsp), (double)offset, (double)len));
1291
1292         if (sio == NULL) {
1293                 return SMB_VFS_NEXT_FALLOCATE(handle, fsp, mode, offset, len);
1294         }
1295
1296         if (!streams_xattr_recheck(sio)) {
1297                 return -1;
1298         }
1299
1300         /* Let the pwrite code path handle it. */
1301         errno = ENOSYS;
1302         return -1;
1303 }
1304
1305
1306 static struct vfs_fn_pointers vfs_streams_xattr_fns = {
1307         .fs_capabilities_fn = streams_xattr_fs_capabilities,
1308         .connect_fn = streams_xattr_connect,
1309         .open_fn = streams_xattr_open,
1310         .stat_fn = streams_xattr_stat,
1311         .fstat_fn = streams_xattr_fstat,
1312         .lstat_fn = streams_xattr_lstat,
1313         .pread_fn = streams_xattr_pread,
1314         .pwrite_fn = streams_xattr_pwrite,
1315         .pread_send_fn = streams_xattr_pread_send,
1316         .pread_recv_fn = streams_xattr_pread_recv,
1317         .pwrite_send_fn = streams_xattr_pwrite_send,
1318         .pwrite_recv_fn = streams_xattr_pwrite_recv,
1319         .unlink_fn = streams_xattr_unlink,
1320         .rename_fn = streams_xattr_rename,
1321         .ftruncate_fn = streams_xattr_ftruncate,
1322         .fallocate_fn = streams_xattr_fallocate,
1323         .streaminfo_fn = streams_xattr_streaminfo,
1324 };
1325
1326 NTSTATUS vfs_streams_xattr_init(TALLOC_CTX *);
1327 NTSTATUS vfs_streams_xattr_init(TALLOC_CTX *ctx)
1328 {
1329         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_xattr",
1330                                 &vfs_streams_xattr_fns);
1331 }