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 *stype;
 110         struct streams_xattr_config *config;
 111
 112         SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
 113                                 return NT_STATUS_UNSUCCESSFUL);
 114
 115         stype = strchr_m(stream_name + 1, ':');
 116
 117         *xattr_name = talloc_asprintf(ctx, "%s%s",
 118                                       config->prefix,
 119                                       stream_name + 1);
 120         if (*xattr_name == NULL) {
 121                 return NT_STATUS_NO_MEMORY;
 122         }
 123
 124         if (stype != NULL) {
 125                 /* Normalize the stream type to upercase. */
 126                 if (!strupper_m(strrchr_m(*xattr_name, ':') + 1)) {
 127                         return NT_STATUS_INVALID_PARAMETER;
 128                 }
 129         } else if (config->store_stream_type) {
 130                 /*
 131                  * Append an explicit stream type if one wasn't
 132                  * specified.
 133                  */
 134                 *xattr_name = talloc_asprintf(ctx, "%s%s",
 135                                               *xattr_name, ":$DATA");
 136                 if (*xattr_name == NULL) {
 137                         return NT_STATUS_NO_MEMORY;
 138                 }
 139         }
 140
 141         DEBUG(10, ("xattr_name: %s, stream_name: %s\n", *xattr_name,
 142                    stream_name));
 143
 144         return NT_STATUS_OK;
 145 }
 146
 147 static bool streams_xattr_recheck(struct stream_io *sio)
 148 {
 149         NTSTATUS status;
 150         char *xattr_name = NULL;
 151
 152         if (sio->fsp->fsp_name == sio->fsp_name_ptr) {
 153                 return true;
 154         }
 155
 156         if (sio->fsp->fsp_name->stream_name == NULL) {
 157                 /* how can this happen */
 158                 errno = EINVAL;
 159                 return false;
 160         }
 161
 162         status = streams_xattr_get_name(sio->handle, talloc_tos(),
 163                                         sio->fsp->fsp_name->stream_name,
 164                                         &xattr_name);
 165         if (!NT_STATUS_IS_OK(status)) {
 166                 return false;
 167         }
 168
 169         TALLOC_FREE(sio->xattr_name);
 170         TALLOC_FREE(sio->base);
 171         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 172                                         xattr_name);
 173         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(sio->handle, sio->fsp),
 174                                   sio->fsp->fsp_name->base_name);
 175         sio->fsp_name_ptr = sio->fsp->fsp_name;
 176
 177         TALLOC_FREE(xattr_name);
 178
 179         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 180                 return false;
 181         }
 182
 183         return true;
 184 }
 185
 186 /**
 187  * Helper to stat/lstat the base file of an smb_fname.
 188  */
 189 static int streams_xattr_stat_base(vfs_handle_struct *handle,
 190                                    struct smb_filename *smb_fname,
 191                                    bool follow_links)
 192 {
 193         char *tmp_stream_name;
 194         int result;
 195
 196         tmp_stream_name = smb_fname->stream_name;
 197         smb_fname->stream_name = NULL;
 198         if (follow_links) {
 199                 result = SMB_VFS_NEXT_STAT(handle, smb_fname);
 200         } else {
 201                 result = SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 202         }
 203         smb_fname->stream_name = tmp_stream_name;
 204         return result;
 205 }
 206
 207 static int streams_xattr_fstat(vfs_handle_struct *handle, files_struct *fsp,
 208                                SMB_STRUCT_STAT *sbuf)
 209 {
 210         struct smb_filename *smb_fname_base = NULL;
 211         int ret = -1;
 212         struct stream_io *io = (struct stream_io *)
 213                 VFS_FETCH_FSP_EXTENSION(handle, fsp);
 214
 215         DEBUG(10, ("streams_xattr_fstat called for %d\n", fsp->fh->fd));
 216
 217         if (io == NULL || fsp->base_fsp == NULL) {
 218                 return SMB_VFS_NEXT_FSTAT(handle, fsp, sbuf);
 219         }
 220
 221         if (!streams_xattr_recheck(io)) {
 222                 return -1;
 223         }
 224
 225         /* Create an smb_filename with stream_name == NULL. */
 226         smb_fname_base = synthetic_smb_fname(talloc_tos(), io->base,
 227                                              NULL, NULL);
 228         if (smb_fname_base == NULL) {
 229                 errno = ENOMEM;
 230                 return -1;
 231         }
 232
 233         if (lp_posix_pathnames()) {
 234                 ret = SMB_VFS_LSTAT(handle->conn, smb_fname_base);
 235         } else {
 236                 ret = SMB_VFS_STAT(handle->conn, smb_fname_base);
 237         }
 238         *sbuf = smb_fname_base->st;
 239         TALLOC_FREE(smb_fname_base);
 240
 241         if (ret == -1) {
 242                 return -1;
 243         }
 244
 245         sbuf->st_ex_size = get_xattr_size(handle->conn, fsp->base_fsp,
 246                                         io->base, io->xattr_name);
 247         if (sbuf->st_ex_size == -1) {
 248                 return -1;
 249         }
 250
 251         DEBUG(10, ("sbuf->st_ex_size = %d\n", (int)sbuf->st_ex_size));
 252
 253         sbuf->st_ex_ino = stream_inode(sbuf, io->xattr_name);
 254         sbuf->st_ex_mode &= ~S_IFMT;
 255         sbuf->st_ex_mode |= S_IFREG;
 256         sbuf->st_ex_blocks = sbuf->st_ex_size / STAT_ST_BLOCKSIZE + 1;
 257
 258         return 0;
 259 }
 260
 261 static int streams_xattr_stat(vfs_handle_struct *handle,
 262                               struct smb_filename *smb_fname)
 263 {
 264         NTSTATUS status;
 265         int result = -1;
 266         char *xattr_name = NULL;
 267
 268         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 269                 return SMB_VFS_NEXT_STAT(handle, smb_fname);
 270         }
 271
 272         /* Note if lp_posix_paths() is true, we can never
 273          * get here as is_ntfs_stream_smb_fname() is
 274          * always false. So we never need worry about
 275          * not following links here. */
 276
 277         /* If the default stream is requested, just stat the base file. */
 278         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 279                 return streams_xattr_stat_base(handle, smb_fname, true);
 280         }
 281
 282         /* Populate the stat struct with info from the base file. */
 283         if (streams_xattr_stat_base(handle, smb_fname, true) == -1) {
 284                 return -1;
 285         }
 286
 287         /* Derive the xattr name to lookup. */
 288         status = streams_xattr_get_name(handle, talloc_tos(),
 289                                         smb_fname->stream_name, &xattr_name);
 290         if (!NT_STATUS_IS_OK(status)) {
 291                 errno = map_errno_from_nt_status(status);
 292                 return -1;
 293         }
 294
 295         /* Augment the base file's stat information before returning. */
 296         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 297                                                   smb_fname->base_name,
 298                                                   xattr_name);
 299         if (smb_fname->st.st_ex_size == -1) {
 300                 errno = ENOENT;
 301                 result = -1;
 302                 goto fail;
 303         }
 304
 305         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 306         smb_fname->st.st_ex_mode &= ~S_IFMT;
 307         smb_fname->st.st_ex_mode |= S_IFREG;
 308         smb_fname->st.st_ex_blocks =
 309             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 310
 311         result = 0;
 312  fail:
 313         TALLOC_FREE(xattr_name);
 314         return result;
 315 }
 316
 317 static int streams_xattr_lstat(vfs_handle_struct *handle,
 318                                struct smb_filename *smb_fname)
 319 {
 320         NTSTATUS status;
 321         int result = -1;
 322         char *xattr_name = NULL;
 323
 324         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 325                 return SMB_VFS_NEXT_LSTAT(handle, smb_fname);
 326         }
 327
 328         /* If the default stream is requested, just stat the base file. */
 329         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 330                 return streams_xattr_stat_base(handle, smb_fname, false);
 331         }
 332
 333         /* Populate the stat struct with info from the base file. */
 334         if (streams_xattr_stat_base(handle, smb_fname, false) == -1) {
 335                 return -1;
 336         }
 337
 338         /* Derive the xattr name to lookup. */
 339         status = streams_xattr_get_name(handle, talloc_tos(),
 340                                         smb_fname->stream_name, &xattr_name);
 341         if (!NT_STATUS_IS_OK(status)) {
 342                 errno = map_errno_from_nt_status(status);
 343                 return -1;
 344         }
 345
 346         /* Augment the base file's stat information before returning. */
 347         smb_fname->st.st_ex_size = get_xattr_size(handle->conn, NULL,
 348                                                   smb_fname->base_name,
 349                                                   xattr_name);
 350         if (smb_fname->st.st_ex_size == -1) {
 351                 errno = ENOENT;
 352                 result = -1;
 353                 goto fail;
 354         }
 355
 356         smb_fname->st.st_ex_ino = stream_inode(&smb_fname->st, xattr_name);
 357         smb_fname->st.st_ex_mode &= ~S_IFMT;
 358         smb_fname->st.st_ex_mode |= S_IFREG;
 359         smb_fname->st.st_ex_blocks =
 360             smb_fname->st.st_ex_size / STAT_ST_BLOCKSIZE + 1;
 361
 362         result = 0;
 363
 364  fail:
 365         TALLOC_FREE(xattr_name);
 366         return result;
 367 }
 368
 369 static int streams_xattr_open(vfs_handle_struct *handle,
 370                               struct smb_filename *smb_fname,
 371                               files_struct *fsp, int flags, mode_t mode)
 372 {
 373         NTSTATUS status;
 374         struct smb_filename *smb_fname_base = NULL;
 375         struct stream_io *sio;
 376         struct ea_struct ea;
 377         char *xattr_name = NULL;
 378         int baseflags;
 379         int hostfd = -1;
 380
 381         DEBUG(10, ("streams_xattr_open called for %s with flags 0x%x\n",
 382                    smb_fname_str_dbg(smb_fname), flags));
 383
 384         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 385                 return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 386         }
 387
 388         /* If the default stream is requested, just open the base file. */
 389         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 390                 char *tmp_stream_name;
 391                 int ret;
 392
 393                 tmp_stream_name = smb_fname->stream_name;
 394                 smb_fname->stream_name = NULL;
 395
 396                 ret = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
 397
 398                 smb_fname->stream_name = tmp_stream_name;
 399
 400                 return ret;
 401         }
 402
 403         status = streams_xattr_get_name(handle, talloc_tos(),
 404                                         smb_fname->stream_name, &xattr_name);
 405         if (!NT_STATUS_IS_OK(status)) {
 406                 errno = map_errno_from_nt_status(status);
 407                 goto fail;
 408         }
 409
 410         /* Create an smb_filename with stream_name == NULL. */
 411         smb_fname_base = synthetic_smb_fname(
 412                 talloc_tos(), smb_fname->base_name, NULL, NULL);
 413         if (smb_fname_base == NULL) {
 414                 errno = ENOMEM;
 415                 goto fail;
 416         }
 417
 418         /*
 419          * We use baseflags to turn off nasty side-effects when opening the
 420          * underlying file.
 421          */
 422         baseflags = flags;
 423         baseflags &= ~O_TRUNC;
 424         baseflags &= ~O_EXCL;
 425         baseflags &= ~O_CREAT;
 426
 427         hostfd = SMB_VFS_OPEN(handle->conn, smb_fname_base, fsp,
 428                               baseflags, mode);
 429
 430         TALLOC_FREE(smb_fname_base);
 431
 432         /* It is legit to open a stream on a directory, but the base
 433          * fd has to be read-only.
 434          */
 435         if ((hostfd == -1) && (errno == EISDIR)) {
 436                 baseflags &= ~O_ACCMODE;
 437                 baseflags |= O_RDONLY;
 438                 hostfd = SMB_VFS_OPEN(handle->conn, smb_fname, fsp, baseflags,
 439                                       mode);
 440         }
 441
 442         if (hostfd == -1) {
 443                 goto fail;
 444         }
 445
 446         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 447                               smb_fname->base_name, xattr_name, &ea);
 448
 449         DEBUG(10, ("get_ea_value returned %s\n", nt_errstr(status)));
 450
 451         if (!NT_STATUS_IS_OK(status)
 452             && !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 453                 /*
 454                  * The base file is not there. This is an error even if we got
 455                  * O_CREAT, the higher levels should have created the base
 456                  * file for us.
 457                  */
 458                 DEBUG(10, ("streams_xattr_open: base file %s not around, "
 459                            "returning ENOENT\n", smb_fname->base_name));
 460                 errno = ENOENT;
 461                 goto fail;
 462         }
 463
 464         if ((!NT_STATUS_IS_OK(status) && (flags & O_CREAT)) ||
 465             (flags & O_TRUNC)) {
 466                 /*
 467                  * The attribute does not exist or needs to be truncated
 468                  */
 469
 470                 /*
 471                  * Darn, xattrs need at least 1 byte
 472                  */
 473                 char null = '\0';
 474
 475                 DEBUG(10, ("creating or truncating attribute %s on file %s\n",
 476                            xattr_name, smb_fname->base_name));
 477
 478                 if (fsp->base_fsp->fh->fd != -1) {
 479                         if (SMB_VFS_FSETXATTR(
 480                                         fsp->base_fsp, xattr_name,
 481                                         &null, sizeof(null),
 482                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 483                                 goto fail;
 484                         }
 485                 } else {
 486                         if (SMB_VFS_SETXATTR(
 487                                         handle->conn, smb_fname->base_name,
 488                                         xattr_name, &null, sizeof(null),
 489                                         flags & O_EXCL ? XATTR_CREATE : 0) == -1) {
 490                                 goto fail;
 491                         }
 492                 }
 493         }
 494
 495         sio = (struct stream_io *)VFS_ADD_FSP_EXTENSION(handle, fsp,
 496                                                         struct stream_io,
 497                                                         NULL);
 498         if (sio == NULL) {
 499                 errno = ENOMEM;
 500                 goto fail;
 501         }
 502
 503         sio->xattr_name = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 504                                         xattr_name);
 505         sio->base = talloc_strdup(VFS_MEMCTX_FSP_EXTENSION(handle, fsp),
 506                                   smb_fname->base_name);
 507         sio->fsp_name_ptr = fsp->fsp_name;
 508         sio->handle = handle;
 509         sio->fsp = fsp;
 510
 511         if ((sio->xattr_name == NULL) || (sio->base == NULL)) {
 512                 errno = ENOMEM;
 513                 goto fail;
 514         }
 515
 516         return hostfd;
 517
 518  fail:
 519         if (hostfd >= 0) {
 520                 /*
 521                  * BUGBUGBUG -- we would need to call fd_close_posix here, but
 522                  * we don't have a full fsp yet
 523                  */
 524                 fsp->fh->fd = hostfd;
 525                 SMB_VFS_CLOSE(fsp);
 526         }
 527
 528         return -1;
 529 }
 530
 531 static int streams_xattr_unlink(vfs_handle_struct *handle,
 532                                 const struct smb_filename *smb_fname)
 533 {
 534         NTSTATUS status;
 535         int ret = -1;
 536         char *xattr_name;
 537
 538         if (!is_ntfs_stream_smb_fname(smb_fname)) {
 539                 return SMB_VFS_NEXT_UNLINK(handle, smb_fname);
 540         }
 541
 542         /* If the default stream is requested, just open the base file. */
 543         if (is_ntfs_default_stream_smb_fname(smb_fname)) {
 544                 struct smb_filename *smb_fname_base = NULL;
 545
 546                 smb_fname_base = cp_smb_filename(talloc_tos(), smb_fname);
 547                 if (smb_fname_base == NULL) {
 548                         errno = ENOMEM;
 549                         return -1;
 550                 }
 551
 552                 ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_base);
 553
 554                 TALLOC_FREE(smb_fname_base);
 555                 return ret;
 556         }
 557
 558         status = streams_xattr_get_name(handle, talloc_tos(),
 559                                         smb_fname->stream_name, &xattr_name);
 560         if (!NT_STATUS_IS_OK(status)) {
 561                 errno = map_errno_from_nt_status(status);
 562                 goto fail;
 563         }
 564
 565         ret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname->base_name, xattr_name);
 566
 567         if ((ret == -1) && (errno == ENOATTR)) {
 568                 errno = ENOENT;
 569                 goto fail;
 570         }
 571
 572         ret = 0;
 573
 574  fail:
 575         TALLOC_FREE(xattr_name);
 576         return ret;
 577 }
 578
 579 static int streams_xattr_rename(vfs_handle_struct *handle,
 580                                 const struct smb_filename *smb_fname_src,
 581                                 const struct smb_filename *smb_fname_dst)
 582 {
 583         NTSTATUS status;
 584         int ret = -1;
 585         char *src_xattr_name = NULL;
 586         char *dst_xattr_name = NULL;
 587         bool src_is_stream, dst_is_stream;
 588         ssize_t oret;
 589         ssize_t nret;
 590         struct ea_struct ea;
 591
 592         src_is_stream = is_ntfs_stream_smb_fname(smb_fname_src);
 593         dst_is_stream = is_ntfs_stream_smb_fname(smb_fname_dst);
 594
 595         if (!src_is_stream && !dst_is_stream) {
 596                 return SMB_VFS_NEXT_RENAME(handle, smb_fname_src,
 597                                            smb_fname_dst);
 598         }
 599
 600         /* For now don't allow renames from or to the default stream. */
 601         if (is_ntfs_default_stream_smb_fname(smb_fname_src) ||
 602             is_ntfs_default_stream_smb_fname(smb_fname_dst)) {
 603                 errno = ENOSYS;
 604                 goto done;
 605         }
 606
 607         /* Don't rename if the streams are identical. */
 608         if (strcasecmp_m(smb_fname_src->stream_name,
 609                        smb_fname_dst->stream_name) == 0) {
 610                 goto done;
 611         }
 612
 613         /* Get the xattr names. */
 614         status = streams_xattr_get_name(handle, talloc_tos(),
 615                                         smb_fname_src->stream_name,
 616                                         &src_xattr_name);
 617         if (!NT_STATUS_IS_OK(status)) {
 618                 errno = map_errno_from_nt_status(status);
 619                 goto fail;
 620         }
 621         status = streams_xattr_get_name(handle, talloc_tos(),
 622                                         smb_fname_dst->stream_name,
 623                                         &dst_xattr_name);
 624         if (!NT_STATUS_IS_OK(status)) {
 625                 errno = map_errno_from_nt_status(status);
 626                 goto fail;
 627         }
 628
 629         /* read the old stream */
 630         status = get_ea_value(talloc_tos(), handle->conn, NULL,
 631                               smb_fname_src->base_name, src_xattr_name, &ea);
 632         if (!NT_STATUS_IS_OK(status)) {
 633                 errno = ENOENT;
 634                 goto fail;
 635         }
 636
 637         /* (over)write the new stream */
 638         nret = SMB_VFS_SETXATTR(handle->conn, smb_fname_src->base_name,
 639                                 dst_xattr_name, ea.value.data, ea.value.length,
 640                                 0);
 641         if (nret < 0) {
 642                 if (errno == ENOATTR) {
 643                         errno = ENOENT;
 644                 }
 645                 goto fail;
 646         }
 647
 648         /* remove the old stream */
 649         oret = SMB_VFS_REMOVEXATTR(handle->conn, smb_fname_src->base_name,
 650                                    src_xattr_name);
 651         if (oret < 0) {
 652                 if (errno == ENOATTR) {
 653                         errno = ENOENT;
 654                 }
 655                 goto fail;
 656         }
 657
 658  done:
 659         errno = 0;
 660         ret = 0;
 661  fail:
 662         TALLOC_FREE(src_xattr_name);
 663         TALLOC_FREE(dst_xattr_name);
 664         return ret;
 665 }
 666
 667 static NTSTATUS walk_xattr_streams(vfs_handle_struct *handle, files_struct *fsp,
 668                                    const char *fname,
 669                                    bool (*fn)(struct ea_struct *ea,
 670                                               void *private_data),
 671                                    void *private_data)
 672 {
 673         NTSTATUS status;
 674         char **names;
 675         size_t i, num_names;
 676         struct streams_xattr_config *config;
 677
 678         SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
 679                                 return NT_STATUS_UNSUCCESSFUL);
 680
 681         status = get_ea_names_from_file(talloc_tos(), handle->conn, fsp, fname,
 682                                         &names, &num_names);
 683         if (!NT_STATUS_IS_OK(status)) {
 684                 return status;
 685         }
 686
 687         for (i=0; i<num_names; i++) {
 688                 struct ea_struct ea;
 689
 690                 if (strncmp(names[i], config->prefix,
 691                             config->prefix_len) != 0) {
 692                         continue;
 693                 }
 694                 if (samba_private_attr_name(names[i])) {
 695                         continue;
 696                 }
 697
 698                 status = get_ea_value(names, handle->conn, fsp, fname,
 699                                       names[i], &ea);
 700                 if (!NT_STATUS_IS_OK(status)) {
 701                         DEBUG(10, ("Could not get ea %s for file %s: %s\n",
 702                                    names[i], fname, nt_errstr(status)));
 703                         continue;
 704                 }
 705
 706                 ea.name = talloc_asprintf(
 707                         ea.value.data, ":%s%s",
 708                         names[i] + config->prefix_len,
 709                         config->store_stream_type ? "" : ":$DATA");
 710                 if (ea.name == NULL) {
 711                         DEBUG(0, ("talloc failed\n"));
 712                         continue;
 713                 }
 714
 715                 if (!fn(&ea, private_data)) {
 716                         TALLOC_FREE(ea.value.data);
 717                         return NT_STATUS_OK;
 718                 }
 719
 720                 TALLOC_FREE(ea.value.data);
 721         }
 722
 723         TALLOC_FREE(names);
 724         return NT_STATUS_OK;
 725 }
 726
 727 static bool add_one_stream(TALLOC_CTX *mem_ctx, unsigned int *num_streams,
 728                            struct stream_struct **streams,
 729                            const char *name, off_t size,
 730                            off_t alloc_size)
 731 {
 732         struct stream_struct *tmp;
 733
 734         tmp = talloc_realloc(mem_ctx, *streams, struct stream_struct,
 735                                    (*num_streams)+1);
 736         if (tmp == NULL) {
 737                 return false;
 738         }
 739
 740         tmp[*num_streams].name = talloc_strdup(tmp, name);
 741         if (tmp[*num_streams].name == NULL) {
 742                 return false;
 743         }
 744
 745         tmp[*num_streams].size = size;
 746         tmp[*num_streams].alloc_size = alloc_size;
 747
 748         *streams = tmp;
 749         *num_streams += 1;
 750         return true;
 751 }
 752
 753 struct streaminfo_state {
 754         TALLOC_CTX *mem_ctx;
 755         vfs_handle_struct *handle;
 756         unsigned int num_streams;
 757         struct stream_struct *streams;
 758         NTSTATUS status;
 759 };
 760
 761 static bool collect_one_stream(struct ea_struct *ea, void *private_data)
 762 {
 763         struct streaminfo_state *state =
 764                 (struct streaminfo_state *)private_data;
 765
 766         if (!add_one_stream(state->mem_ctx,
 767                             &state->num_streams, &state->streams,
 768                             ea->name, ea->value.length-1,
 769                             smb_roundup(state->handle->conn,
 770                                         ea->value.length-1))) {
 771                 state->status = NT_STATUS_NO_MEMORY;
 772                 return false;
 773         }
 774
 775         return true;
 776 }
 777
 778 static NTSTATUS streams_xattr_streaminfo(vfs_handle_struct *handle,
 779                                          struct files_struct *fsp,
 780                                          const char *fname,
 781                                          TALLOC_CTX *mem_ctx,
 782                                          unsigned int *pnum_streams,
 783                                          struct stream_struct **pstreams)
 784 {
 785         SMB_STRUCT_STAT sbuf;
 786         int ret;
 787         NTSTATUS status;
 788         struct streaminfo_state state;
 789
 790         if ((fsp != NULL) && (fsp->fh->fd != -1)) {
 791                 ret = SMB_VFS_FSTAT(fsp, &sbuf);
 792         }
 793         else {
 794                 struct smb_filename *smb_fname = NULL;
 795                 smb_fname = synthetic_smb_fname(talloc_tos(), fname, NULL,
 796                                                 NULL);
 797                 if (smb_fname == NULL) {
 798                         return NT_STATUS_NO_MEMORY;
 799                 }
 800                 if (lp_posix_pathnames()) {
 801                         ret = SMB_VFS_LSTAT(handle->conn, smb_fname);
 802                 } else {
 803                         ret = SMB_VFS_STAT(handle->conn, smb_fname);
 804                 }
 805                 sbuf = smb_fname->st;
 806                 TALLOC_FREE(smb_fname);
 807         }
 808
 809         if (ret == -1) {
 810                 return map_nt_error_from_unix(errno);
 811         }
 812
 813         state.streams = *pstreams;
 814         state.num_streams = *pnum_streams;
 815         state.mem_ctx = mem_ctx;
 816         state.handle = handle;
 817         state.status = NT_STATUS_OK;
 818
 819         if (S_ISLNK(sbuf.st_ex_mode)) {
 820                 /*
 821                  * Currently we do't have SMB_VFS_LLISTXATTR
 822                  * inside the VFS which means there's no way
 823                  * to cope with a symlink when lp_posix_pathnames().
 824                  * returns true. For now ignore links.
 825                  * FIXME - by adding SMB_VFS_LLISTXATTR. JRA.
 826                  */
 827                 status = NT_STATUS_OK;
 828         } else {
 829                 status = walk_xattr_streams(handle, fsp, fname,
 830                                     collect_one_stream, &state);
 831         }
 832
 833         if (!NT_STATUS_IS_OK(status)) {
 834                 TALLOC_FREE(state.streams);
 835                 return status;
 836         }
 837
 838         if (!NT_STATUS_IS_OK(state.status)) {
 839                 TALLOC_FREE(state.streams);
 840                 return state.status;
 841         }
 842
 843         *pnum_streams = state.num_streams;
 844         *pstreams = state.streams;
 845
 846         return SMB_VFS_NEXT_STREAMINFO(handle, fsp, fname, mem_ctx, pnum_streams, pstreams);
 847 }
 848
 849 static uint32_t streams_xattr_fs_capabilities(struct vfs_handle_struct *handle,
 850                         enum timestamp_set_resolution *p_ts_res)
 851 {
 852         return SMB_VFS_NEXT_FS_CAPABILITIES(handle, p_ts_res) | FILE_NAMED_STREAMS;
 853 }
 854
 855 static int streams_xattr_connect(vfs_handle_struct *handle,
 856                                  const char *service, const char *user)
 857 {
 858         struct streams_xattr_config *config;
 859         const char *default_prefix = SAMBA_XATTR_DOSSTREAM_PREFIX;
 860         const char *prefix;
 861
 862         config = talloc_zero(handle->conn, struct streams_xattr_config);
 863         if (config == NULL) {
 864                 DEBUG(1, ("talloc_zero() failed\n"));
 865                 errno = ENOMEM;
 866                 return -1;
 867         }
 868
 869         prefix = lp_parm_const_string(SNUM(handle->conn),
 870                                       "streams_xattr", "prefix",
 871                                       default_prefix);
 872         config->prefix = talloc_strdup(config, prefix);
 873         if (config->prefix == NULL) {
 874                 DEBUG(1, ("talloc_strdup() failed\n"));
 875                 errno = ENOMEM;
 876                 return -1;
 877         }
 878         config->prefix_len = strlen(config->prefix);
 879         DEBUG(10, ("streams_xattr using stream prefix: %s\n", config->prefix));
 880
 881         config->store_stream_type = lp_parm_bool(SNUM(handle->conn),
 882                                                  "streams_xattr",
 883                                                  "store_stream_type",
 884                                                  true);
 885
 886         SMB_VFS_HANDLE_SET_DATA(handle, config,
 887                                 NULL, struct stream_xattr_config,
 888                                 return -1);
 889
 890         return 0;
 891 }
 892
 893 static ssize_t streams_xattr_pwrite(vfs_handle_struct *handle,
 894                                     files_struct *fsp, const void *data,
 895                                     size_t n, off_t offset)
 896 {
 897         struct stream_io *sio =
 898                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 899         struct ea_struct ea;
 900         NTSTATUS status;
 901         int ret;
 902
 903         DEBUG(10, ("streams_xattr_pwrite called for %d bytes\n", (int)n));
 904
 905         if (sio == NULL) {
 906                 return SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset);
 907         }
 908
 909         if (!streams_xattr_recheck(sio)) {
 910                 return -1;
 911         }
 912
 913         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
 914                               sio->base, sio->xattr_name, &ea);
 915         if (!NT_STATUS_IS_OK(status)) {
 916                 return -1;
 917         }
 918
 919         if ((offset + n) > ea.value.length-1) {
 920                 uint8 *tmp;
 921
 922                 tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8,
 923                                            offset + n + 1);
 924
 925                 if (tmp == NULL) {
 926                         TALLOC_FREE(ea.value.data);
 927                         errno = ENOMEM;
 928                         return -1;
 929                 }
 930                 ea.value.data = tmp;
 931                 ea.value.length = offset + n + 1;
 932                 ea.value.data[offset+n] = 0;
 933         }
 934
 935         memcpy(ea.value.data + offset, data, n);
 936
 937         if (fsp->base_fsp->fh->fd != -1) {
 938                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
 939                                 sio->xattr_name,
 940                                 ea.value.data, ea.value.length, 0);
 941         } else {
 942                 ret = SMB_VFS_SETXATTR(fsp->conn,
 943                                        fsp->base_fsp->fsp_name->base_name,
 944                                 sio->xattr_name,
 945                                 ea.value.data, ea.value.length, 0);
 946         }
 947         TALLOC_FREE(ea.value.data);
 948
 949         if (ret == -1) {
 950                 return -1;
 951         }
 952
 953         return n;
 954 }
 955
 956 static ssize_t streams_xattr_pread(vfs_handle_struct *handle,
 957                                    files_struct *fsp, void *data,
 958                                    size_t n, off_t offset)
 959 {
 960         struct stream_io *sio =
 961                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
 962         struct ea_struct ea;
 963         NTSTATUS status;
 964         size_t length, overlap;
 965
 966         DEBUG(10, ("streams_xattr_pread: offset=%d, size=%d\n",
 967                    (int)offset, (int)n));
 968
 969         if (sio == NULL) {
 970                 return SMB_VFS_NEXT_PREAD(handle, fsp, data, n, offset);
 971         }
 972
 973         if (!streams_xattr_recheck(sio)) {
 974                 return -1;
 975         }
 976
 977         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
 978                               sio->base, sio->xattr_name, &ea);
 979         if (!NT_STATUS_IS_OK(status)) {
 980                 return -1;
 981         }
 982
 983         length = ea.value.length-1;
 984
 985         DEBUG(10, ("streams_xattr_pread: get_ea_value returned %d bytes\n",
 986                    (int)length));
 987
 988         /* Attempt to read past EOF. */
 989         if (length <= offset) {
 990                 return 0;
 991         }
 992
 993         overlap = (offset + n) > length ? (length - offset) : n;
 994         memcpy(data, ea.value.data + offset, overlap);
 995
 996         TALLOC_FREE(ea.value.data);
 997         return overlap;
 998 }
 999
1000 static int streams_xattr_ftruncate(struct vfs_handle_struct *handle,
1001                                         struct files_struct *fsp,
1002                                         off_t offset)
1003 {
1004         int ret;
1005         uint8 *tmp;
1006         struct ea_struct ea;
1007         NTSTATUS status;
1008         struct stream_io *sio =
1009                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1010
1011         DEBUG(10, ("streams_xattr_ftruncate called for file %s offset %.0f\n",
1012                    fsp_str_dbg(fsp), (double)offset));
1013
1014         if (sio == NULL) {
1015                 return SMB_VFS_NEXT_FTRUNCATE(handle, fsp, offset);
1016         }
1017
1018         if (!streams_xattr_recheck(sio)) {
1019                 return -1;
1020         }
1021
1022         status = get_ea_value(talloc_tos(), handle->conn, fsp->base_fsp,
1023                               sio->base, sio->xattr_name, &ea);
1024         if (!NT_STATUS_IS_OK(status)) {
1025                 return -1;
1026         }
1027
1028         tmp = talloc_realloc(talloc_tos(), ea.value.data, uint8,
1029                                    offset + 1);
1030
1031         if (tmp == NULL) {
1032                 TALLOC_FREE(ea.value.data);
1033                 errno = ENOMEM;
1034                 return -1;
1035         }
1036
1037         /* Did we expand ? */
1038         if (ea.value.length < offset + 1) {
1039                 memset(&tmp[ea.value.length], '\0',
1040                         offset + 1 - ea.value.length);
1041         }
1042
1043         ea.value.data = tmp;
1044         ea.value.length = offset + 1;
1045         ea.value.data[offset] = 0;
1046
1047         if (fsp->base_fsp->fh->fd != -1) {
1048                 ret = SMB_VFS_FSETXATTR(fsp->base_fsp,
1049                                 sio->xattr_name,
1050                                 ea.value.data, ea.value.length, 0);
1051         } else {
1052                 ret = SMB_VFS_SETXATTR(fsp->conn,
1053                                        fsp->base_fsp->fsp_name->base_name,
1054                                 sio->xattr_name,
1055                                 ea.value.data, ea.value.length, 0);
1056         }
1057
1058         TALLOC_FREE(ea.value.data);
1059
1060         if (ret == -1) {
1061                 return -1;
1062         }
1063
1064         return 0;
1065 }
1066
1067 static int streams_xattr_fallocate(struct vfs_handle_struct *handle,
1068                                         struct files_struct *fsp,
1069                                         enum vfs_fallocate_mode mode,
1070                                         off_t offset,
1071                                         off_t len)
1072 {
1073         struct stream_io *sio =
1074                 (struct stream_io *)VFS_FETCH_FSP_EXTENSION(handle, fsp);
1075
1076         DEBUG(10, ("streams_xattr_fallocate called for file %s offset %.0f"
1077                 "len = %.0f\n",
1078                 fsp_str_dbg(fsp), (double)offset, (double)len));
1079
1080         if (sio == NULL) {
1081                 return SMB_VFS_NEXT_FALLOCATE(handle, fsp, mode, offset, len);
1082         }
1083
1084         if (!streams_xattr_recheck(sio)) {
1085                 return errno;
1086         }
1087
1088         /* Let the pwrite code path handle it. */
1089         return ENOSYS;
1090 }
1091
1092
1093 static struct vfs_fn_pointers vfs_streams_xattr_fns = {
1094         .fs_capabilities_fn = streams_xattr_fs_capabilities,
1095         .connect_fn = streams_xattr_connect,
1096         .open_fn = streams_xattr_open,
1097         .stat_fn = streams_xattr_stat,
1098         .fstat_fn = streams_xattr_fstat,
1099         .lstat_fn = streams_xattr_lstat,
1100         .pread_fn = streams_xattr_pread,
1101         .pwrite_fn = streams_xattr_pwrite,
1102         .unlink_fn = streams_xattr_unlink,
1103         .rename_fn = streams_xattr_rename,
1104         .ftruncate_fn = streams_xattr_ftruncate,
1105         .fallocate_fn = streams_xattr_fallocate,
1106         .streaminfo_fn = streams_xattr_streaminfo,
1107 };
1108
1109 NTSTATUS vfs_streams_xattr_init(void);
1110 NTSTATUS vfs_streams_xattr_init(void)
1111 {
1112         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "streams_xattr",
1113                                 &vfs_streams_xattr_fns);
1114 }