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   1 /*
   2  * ntfs-capture.c
   3  *
   4  * Capture a WIM image from a NTFS volume.  We capture everything we can,
   5  * including security data and alternate data streams.
   6  */
   7
   8 /*
   9  * Copyright (C) 2012 Eric Biggers
  10  *
  11  * This file is part of wimlib, a library for working with WIM files.
  12  *
  13  * wimlib is free software; you can redistribute it and/or modify it under the
  14  * terms of the GNU General Public License as published by the Free
  15  * Software Foundation; either version 3 of the License, or (at your option)
  16  * any later version.
  17  *
  18  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  19  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  20  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  25  */
  26
  27
  28 #include "config.h"
  29
  30 #include <ntfs-3g/endians.h>
  31 #include <ntfs-3g/types.h>
  32
  33 #include "wimlib_internal.h"
  34
  35
  36 #include "dentry.h"
  37 #include "lookup_table.h"
  38 #include "io.h"
  39 #include <ntfs-3g/layout.h>
  40 #include <ntfs-3g/acls.h>
  41 #include <ntfs-3g/attrib.h>
  42 #include <ntfs-3g/misc.h>
  43 #include <ntfs-3g/reparse.h>
  44 #include <ntfs-3g/security.h> /* security.h before xattrs.h */
  45 #include <ntfs-3g/xattrs.h>
  46 #include <ntfs-3g/volume.h>
  47 #include <stdlib.h>
  48 #include <unistd.h>
  49 #include <errno.h>
  50
  51 /* Structure that allows searching the security descriptors by SHA1 message
  52  * digest. */
  53 struct sd_set {
  54         struct wim_security_data *sd;
  55         struct sd_node *root;
  56 };
  57
  58 /* Binary tree node of security descriptors, indexed by the @hash field. */
  59 struct sd_node {
  60         int security_id;
  61         u8 hash[SHA1_HASH_SIZE];
  62         struct sd_node *left;
  63         struct sd_node *right;
  64 };
  65
  66 static void free_sd_tree(struct sd_node *root)
  67 {
  68         if (root) {
  69                 free_sd_tree(root->left);
  70                 free_sd_tree(root->right);
  71                 FREE(root);
  72         }
  73 }
  74 /* Frees a security descriptor index set. */
  75 static void destroy_sd_set(struct sd_set *sd_set)
  76 {
  77         free_sd_tree(sd_set->root);
  78 }
  79
  80 /* Inserts a a new node into the security descriptor index tree. */
  81 static void insert_sd_node(struct sd_node *new, struct sd_node *root)
  82 {
  83         int cmp = hashes_cmp(new->hash, root->hash);
  84         if (cmp < 0) {
  85                 if (root->left)
  86                         insert_sd_node(new, root->left);
  87                 else
  88                         root->left = new;
  89         } else if (cmp > 0) {
  90                 if (root->right)
  91                         insert_sd_node(new, root->right);
  92                 else
  93                         root->right = new;
  94         } else {
  95                 wimlib_assert(0);
  96         }
  97 }
  98
  99 /* Returns the security ID of the security data having a SHA1 message digest of
 100  * @hash in the security descriptor index tree rooted at @root.
 101  *
 102  * If not found, return -1. */
 103 static int lookup_sd(const u8 hash[SHA1_HASH_SIZE], struct sd_node *root)
 104 {
 105         int cmp;
 106         if (!root)
 107                 return -1;
 108         cmp = hashes_cmp(hash, root->hash);
 109         if (cmp < 0)
 110                 return lookup_sd(hash, root->left);
 111         else if (cmp > 0)
 112                 return lookup_sd(hash, root->right);
 113         else
 114                 return root->security_id;
 115 }
 116
 117 /*
 118  * Adds a security descriptor to the indexed security descriptor set as well as
 119  * the corresponding `struct wim_security_data', and returns the new security
 120  * ID; or, if there is an existing security descriptor that is the same, return
 121  * the security ID for it.  If a new security descriptor cannot be allocated,
 122  * return -1.
 123  */
 124 static int sd_set_add_sd(struct sd_set *sd_set, const char descriptor[],
 125                          size_t size)
 126 {
 127         u8 hash[SHA1_HASH_SIZE];
 128         int security_id;
 129         struct sd_node *new;
 130         u8 **descriptors;
 131         u64 *sizes;
 132         u8 *descr_copy;
 133         struct wim_security_data *sd;
 134
 135         sha1_buffer((const u8*)descriptor, size, hash);
 136
 137         security_id = lookup_sd(hash, sd_set->root);
 138         if (security_id >= 0)
 139                 return security_id;
 140
 141         new = MALLOC(sizeof(*new));
 142         if (!new)
 143                 goto out;
 144         descr_copy = MALLOC(size);
 145         if (!descr_copy)
 146                 goto out_free_node;
 147
 148         sd = sd_set->sd;
 149
 150         memcpy(descr_copy, descriptor, size);
 151         new->security_id = sd->num_entries;
 152         new->left = NULL;
 153         new->right = NULL;
 154         copy_hash(new->hash, hash);
 155
 156
 157         descriptors = REALLOC(sd->descriptors,
 158                               (sd->num_entries + 1) * sizeof(sd->descriptors[0]));
 159         if (!descriptors)
 160                 goto out_free_descr;
 161         sd->descriptors = descriptors;
 162         sizes = REALLOC(sd->sizes,
 163                         (sd->num_entries + 1) * sizeof(sd->sizes[0]));
 164         if (!sizes)
 165                 goto out_free_descr;
 166         sd->sizes = sizes;
 167         sd->descriptors[sd->num_entries] = descr_copy;
 168         sd->sizes[sd->num_entries] = size;
 169         sd->num_entries++;
 170         DEBUG("There are now %d security descriptors", sd->num_entries);
 171         sd->total_length += size + sizeof(sd->sizes[0]);
 172
 173         if (sd_set->root)
 174                 insert_sd_node(new, sd_set->root);
 175         else
 176                 sd_set->root = new;
 177         return new->security_id;
 178 out_free_descr:
 179         FREE(descr_copy);
 180 out_free_node:
 181         FREE(new);
 182 out:
 183         return -1;
 184 }
 185
 186 static inline ntfschar *attr_record_name(ATTR_RECORD *ar)
 187 {
 188         return (ntfschar*)((u8*)ar + le16_to_cpu(ar->name_offset));
 189 }
 190
 191 /* Calculates the SHA1 message digest of a NTFS attribute.
 192  *
 193  * @ni:  The NTFS inode containing the attribute.
 194  * @ar:  The ATTR_RECORD describing the attribute.
 195  * @md:  If successful, the returned SHA1 message digest.
 196  * @reparse_tag_ret:    Optional pointer into which the first 4 bytes of the
 197  *                              attribute will be written (to get the reparse
 198  *                              point ID)
 199  *
 200  * Return 0 on success or nonzero on error.
 201  */
 202 static int ntfs_attr_sha1sum(ntfs_inode *ni, ATTR_RECORD *ar,
 203                              u8 md[SHA1_HASH_SIZE],
 204                              bool is_reparse_point,
 205                              u32 *reparse_tag_ret)
 206 {
 207         s64 pos = 0;
 208         s64 bytes_remaining;
 209         char buf[BUFFER_SIZE];
 210         ntfs_attr *na;
 211         SHA_CTX ctx;
 212
 213         na = ntfs_attr_open(ni, ar->type, attr_record_name(ar),
 214                             ar->name_length);
 215         if (!na) {
 216                 ERROR_WITH_ERRNO("Failed to open NTFS attribute");
 217                 return WIMLIB_ERR_NTFS_3G;
 218         }
 219
 220         bytes_remaining = na->data_size;
 221
 222         if (is_reparse_point) {
 223                 if (ntfs_attr_pread(na, 0, 8, buf) != 8)
 224                         goto out_error;
 225                 *reparse_tag_ret = le32_to_cpu(*(u32*)buf);
 226                 pos = 8;
 227                 bytes_remaining -= 8;
 228         }
 229
 230         sha1_init(&ctx);
 231         while (bytes_remaining) {
 232                 s64 to_read = min(bytes_remaining, sizeof(buf));
 233                 if (ntfs_attr_pread(na, pos, to_read, buf) != to_read)
 234                         goto out_error;
 235                 sha1_update(&ctx, buf, to_read);
 236                 pos += to_read;
 237                 bytes_remaining -= to_read;
 238         }
 239         sha1_final(md, &ctx);
 240         ntfs_attr_close(na);
 241         return 0;
 242 out_error:
 243         ERROR_WITH_ERRNO("Error reading NTFS attribute");
 244         return WIMLIB_ERR_NTFS_3G;
 245 }
 246
 247 /* Load the streams from a file or reparse point in the NTFS volume into the WIM
 248  * lookup table */
 249 static int capture_ntfs_streams(struct dentry *dentry, ntfs_inode *ni,
 250                                 char path[], size_t path_len,
 251                                 struct lookup_table *lookup_table,
 252                                 ntfs_volume **ntfs_vol_p,
 253                                 ATTR_TYPES type)
 254 {
 255         ntfs_attr_search_ctx *actx;
 256         u8 attr_hash[SHA1_HASH_SIZE];
 257         struct ntfs_location *ntfs_loc = NULL;
 258         int ret = 0;
 259         struct lookup_table_entry *lte;
 260
 261         DEBUG2("Capturing NTFS data streams from `%s'", path);
 262
 263         /* Get context to search the streams of the NTFS file. */
 264         actx = ntfs_attr_get_search_ctx(ni, NULL);
 265         if (!actx) {
 266                 ERROR_WITH_ERRNO("Cannot get NTFS attribute search "
 267                                  "context");
 268                 return WIMLIB_ERR_NTFS_3G;
 269         }
 270
 271         /* Capture each data stream or reparse data stream. */
 272         while (!ntfs_attr_lookup(type, NULL, 0,
 273                                  CASE_SENSITIVE, 0, NULL, 0, actx))
 274         {
 275                 char *stream_name_utf8;
 276                 u32 reparse_tag;
 277                 u64 data_size = ntfs_get_attribute_value_length(actx->attr);
 278                 u64 name_length = actx->attr->name_length;
 279
 280                 if (data_size == 0) {
 281                         if (errno != 0) {
 282                                 ERROR_WITH_ERRNO("Failed to get size of attribute of "
 283                                                  "`%s'", path);
 284                                 ret = WIMLIB_ERR_NTFS_3G;
 285                                 goto out_put_actx;
 286                         }
 287                         /* Empty stream.  No lookup table entry is needed. */
 288                         lte = NULL;
 289                 } else {
 290                         if (type == AT_REPARSE_POINT && data_size < 8) {
 291                                 ERROR("`%s': reparse point buffer too small",
 292                                       path);
 293                                 ret = WIMLIB_ERR_NTFS_3G;
 294                                 goto out_put_actx;
 295                         }
 296                         /* Checksum the stream. */
 297                         ret = ntfs_attr_sha1sum(ni, actx->attr, attr_hash,
 298                                                 type == AT_REPARSE_POINT, &reparse_tag);
 299                         if (ret != 0)
 300                                 goto out_put_actx;
 301
 302                         /* Make a lookup table entry for the stream, or use an existing
 303                          * one if there's already an identical stream. */
 304                         lte = __lookup_resource(lookup_table, attr_hash);
 305                         ret = WIMLIB_ERR_NOMEM;
 306                         if (lte) {
 307                                 lte->refcnt++;
 308                         } else {
 309                                 ntfs_loc = CALLOC(1, sizeof(*ntfs_loc));
 310                                 if (!ntfs_loc)
 311                                         goto out_put_actx;
 312                                 ntfs_loc->ntfs_vol_p = ntfs_vol_p;
 313                                 ntfs_loc->path_utf8 = MALLOC(path_len + 1);
 314                                 if (!ntfs_loc->path_utf8)
 315                                         goto out_free_ntfs_loc;
 316                                 memcpy(ntfs_loc->path_utf8, path, path_len + 1);
 317                                 if (name_length) {
 318                                         ntfs_loc->stream_name_utf16 = MALLOC(name_length * 2);
 319                                         if (!ntfs_loc->stream_name_utf16)
 320                                                 goto out_free_ntfs_loc;
 321                                         memcpy(ntfs_loc->stream_name_utf16,
 322                                                attr_record_name(actx->attr),
 323                                                actx->attr->name_length * 2);
 324                                         ntfs_loc->stream_name_utf16_num_chars = name_length;
 325                                 }
 326
 327                                 lte = new_lookup_table_entry();
 328                                 if (!lte)
 329                                         goto out_free_ntfs_loc;
 330                                 lte->ntfs_loc = ntfs_loc;
 331                                 lte->resource_location = RESOURCE_IN_NTFS_VOLUME;
 332                                 if (type == AT_REPARSE_POINT) {
 333                                         dentry->d_inode->reparse_tag = reparse_tag;
 334                                         ntfs_loc->is_reparse_point = true;
 335                                         lte->resource_entry.original_size = data_size - 8;
 336                                         lte->resource_entry.size = data_size - 8;
 337                                 } else {
 338                                         ntfs_loc->is_reparse_point = false;
 339                                         lte->resource_entry.original_size = data_size;
 340                                         lte->resource_entry.size = data_size;
 341                                 }
 342                                 ntfs_loc = NULL;
 343                                 DEBUG("Add resource for `%s' (size = %zu)",
 344                                       dentry->file_name_utf8,
 345                                       lte->resource_entry.original_size);
 346                                 copy_hash(lte->hash, attr_hash);
 347                                 lookup_table_insert(lookup_table, lte);
 348                         }
 349                 }
 350                 if (name_length == 0) {
 351                         /* Unnamed data stream.  Put the reference to it in the
 352                          * dentry's inode. */
 353                         if (dentry->d_inode->lte) {
 354                                 ERROR("Found two un-named data streams for "
 355                                       "`%s'", path);
 356                                 ret = WIMLIB_ERR_NTFS_3G;
 357                                 goto out_free_lte;
 358                         }
 359                         dentry->d_inode->lte = lte;
 360                 } else {
 361                         /* Named data stream.  Put the reference to it in the
 362                          * alternate data stream entries */
 363                         struct ads_entry *new_ads_entry;
 364                         size_t stream_name_utf8_len;
 365                         stream_name_utf8 = utf16_to_utf8((const char*)attr_record_name(actx->attr),
 366                                                          name_length * 2,
 367                                                          &stream_name_utf8_len);
 368                         if (!stream_name_utf8)
 369                                 goto out_free_lte;
 370                         new_ads_entry = inode_add_ads(dentry->d_inode, stream_name_utf8);
 371                         FREE(stream_name_utf8);
 372                         if (!new_ads_entry)
 373                                 goto out_free_lte;
 374
 375                         wimlib_assert(new_ads_entry->stream_name_len == name_length * 2);
 376
 377                         new_ads_entry->lte = lte;
 378                 }
 379         }
 380         ret = 0;
 381         goto out_put_actx;
 382 out_free_lte:
 383         free_lookup_table_entry(lte);
 384 out_free_ntfs_loc:
 385         if (ntfs_loc) {
 386                 FREE(ntfs_loc->path_utf8);
 387                 FREE(ntfs_loc->stream_name_utf16);
 388                 FREE(ntfs_loc);
 389         }
 390 out_put_actx:
 391         ntfs_attr_put_search_ctx(actx);
 392         if (ret == 0)
 393                 DEBUG2("Successfully captured NTFS streams from `%s'", path);
 394         else
 395                 ERROR("Failed to capture NTFS streams from `%s", path);
 396         return ret;
 397 }
 398
 399 struct readdir_ctx {
 400         struct dentry       *parent;
 401         ntfs_inode          *dir_ni;
 402         char                *path;
 403         size_t               path_len;
 404         struct lookup_table *lookup_table;
 405         struct sd_set       *sd_set;
 406         const struct capture_config *config;
 407         ntfs_volume        **ntfs_vol_p;
 408         int                  flags;
 409 };
 410
 411 static int
 412 build_dentry_tree_ntfs_recursive(struct dentry **root_p, ntfs_inode *dir_ni,
 413                                  ntfs_inode *ni, char path[], size_t path_len,
 414                                  int name_type,
 415                                  struct lookup_table *lookup_table,
 416                                  struct sd_set *sd_set,
 417                                  const struct capture_config *config,
 418                                  ntfs_volume **ntfs_vol_p,
 419                                  int flags);
 420
 421 static int wim_ntfs_capture_filldir(void *dirent, const ntfschar *name,
 422                                     const int name_len, const int name_type,
 423                                     const s64 pos, const MFT_REF mref,
 424                                     const unsigned dt_type)
 425 {
 426         struct readdir_ctx *ctx;
 427         size_t utf8_name_len;
 428         char *utf8_name;
 429         struct dentry *child = NULL;
 430         int ret;
 431         size_t path_len;
 432
 433         if (name_type == FILE_NAME_DOS)
 434                 return 0;
 435
 436         ret = -1;
 437
 438         utf8_name = utf16_to_utf8((const char*)name, name_len * 2,
 439                                   &utf8_name_len);
 440         if (!utf8_name)
 441                 goto out;
 442
 443         if (utf8_name[0] == '.' &&
 444              (utf8_name[1] == '\0' ||
 445               (utf8_name[1] == '.' && utf8_name[2] == '\0'))) {
 446                 ret = 0;
 447                 goto out_free_utf8_name;
 448         }
 449
 450         ctx = dirent;
 451
 452         ntfs_inode *ni = ntfs_inode_open(ctx->dir_ni->vol, mref);
 453         if (!ni) {
 454                 ERROR_WITH_ERRNO("Failed to open NTFS inode");
 455                 goto out_free_utf8_name;
 456         }
 457         path_len = ctx->path_len;
 458         if (path_len != 1)
 459                 ctx->path[path_len++] = '/';
 460         memcpy(ctx->path + path_len, utf8_name, utf8_name_len + 1);
 461         path_len += utf8_name_len;
 462         ret = build_dentry_tree_ntfs_recursive(&child, ctx->dir_ni,
 463                                                ni, ctx->path, path_len, name_type,
 464                                                ctx->lookup_table, ctx->sd_set,
 465                                                ctx->config, ctx->ntfs_vol_p,
 466                                                ctx->flags);
 467
 468         if (child)
 469                 dentry_add_child(ctx->parent, child);
 470
 471         ntfs_inode_close(ni);
 472 out_free_utf8_name:
 473         FREE(utf8_name);
 474 out:
 475         return ret;
 476 }
 477
 478 static int change_dentry_short_name(struct dentry *dentry,
 479                                     const char short_name_utf8[],
 480                                     int short_name_utf8_len)
 481 {
 482         size_t short_name_utf16_len;
 483         char *short_name_utf16;
 484         short_name_utf16 = utf8_to_utf16(short_name_utf8, short_name_utf8_len,
 485                                          &short_name_utf16_len);
 486         if (!short_name_utf16) {
 487                 ERROR_WITH_ERRNO("Failed to convert short name to UTF-16");
 488                 return WIMLIB_ERR_NOMEM;
 489         }
 490         dentry->short_name = short_name_utf16;
 491         dentry->short_name_len = short_name_utf16_len;
 492         return 0;
 493 }
 494
 495 /* Recursively build a WIM dentry tree corresponding to a NTFS volume.
 496  * At the same time, update the WIM lookup table with lookup table entries for
 497  * the NTFS streams, and build an array of security descriptors.
 498  */
 499 static int build_dentry_tree_ntfs_recursive(struct dentry **root_p,
 500                                             ntfs_inode *dir_ni,
 501                                             ntfs_inode *ni,
 502                                             char path[],
 503                                             size_t path_len,
 504                                             int name_type,
 505                                             struct lookup_table *lookup_table,
 506                                             struct sd_set *sd_set,
 507                                             const struct capture_config *config,
 508                                             ntfs_volume **ntfs_vol_p,
 509                                             int flags)
 510 {
 511         u32 attributes;
 512         int mrec_flags;
 513         int ret;
 514         char dos_name_utf8[64];
 515         struct dentry *root;
 516
 517         mrec_flags = ni->mrec->flags;
 518         struct SECURITY_CONTEXT ctx;
 519         memset(&ctx, 0, sizeof(ctx));
 520         ctx.vol = ni->vol;
 521         ret = ntfs_xattr_system_getxattr(&ctx, XATTR_NTFS_ATTRIB,
 522                                          ni, dir_ni, (char *)&attributes,
 523                                          sizeof(u32));
 524         if (ret != 4) {
 525                 ERROR_WITH_ERRNO("Failed to get NTFS attributes from `%s'",
 526                                  path);
 527                 return WIMLIB_ERR_NTFS_3G;
 528         }
 529
 530         if (exclude_path(path, config, false)) {
 531                 if (flags & WIMLIB_ADD_IMAGE_FLAG_VERBOSE) {
 532                         const char *file_type;
 533                         if (attributes & MFT_RECORD_IS_DIRECTORY)
 534                                 file_type = "directory";
 535                         else
 536                                 file_type = "file";
 537                         printf("Excluding %s `%s' from capture\n",
 538                                file_type, path);
 539                 }
 540                 *root_p = NULL;
 541                 return 0;
 542         }
 543
 544         if (flags & WIMLIB_ADD_IMAGE_FLAG_VERBOSE)
 545                 printf("Scanning `%s'\n", path);
 546
 547         root = new_dentry_with_timeless_inode(path_basename(path));
 548         if (!root)
 549                 return WIMLIB_ERR_NOMEM;
 550         *root_p = root;
 551
 552         if (dir_ni && (name_type == FILE_NAME_WIN32_AND_DOS
 553                        || name_type == FILE_NAME_WIN32))
 554         {
 555                 ret = ntfs_get_ntfs_dos_name(ni, dir_ni, dos_name_utf8,
 556                                              sizeof(dos_name_utf8));
 557                 if (ret > 0) {
 558                         DEBUG("Changing short name of `%s'", path);
 559                         ret = change_dentry_short_name(root, dos_name_utf8,
 560                                                        ret);
 561                         if (ret != 0)
 562                                 return ret;
 563                 } else {
 564                 #ifdef ENODATA
 565                         if (errno != ENODATA) {
 566                                 ERROR_WITH_ERRNO("Error getting DOS name "
 567                                                  "of `%s'", path);
 568                                 return WIMLIB_ERR_NTFS_3G;
 569                         }
 570                 #endif
 571                 }
 572         }
 573
 574         root->d_inode->creation_time    = le64_to_cpu(ni->creation_time);
 575         root->d_inode->last_write_time  = le64_to_cpu(ni->last_data_change_time);
 576         root->d_inode->last_access_time = le64_to_cpu(ni->last_access_time);
 577         root->d_inode->attributes       = le32_to_cpu(attributes);
 578         root->d_inode->ino              = ni->mft_no;
 579         root->d_inode->resolved         = true;
 580
 581         if (attributes & FILE_ATTR_REPARSE_POINT) {
 582                 /* Junction point, symbolic link, or other reparse point */
 583                 ret = capture_ntfs_streams(root, ni, path, path_len,
 584                                            lookup_table, ntfs_vol_p,
 585                                            AT_REPARSE_POINT);
 586         } else if (mrec_flags & MFT_RECORD_IS_DIRECTORY) {
 587
 588                 /* Normal directory */
 589                 s64 pos = 0;
 590                 struct readdir_ctx ctx = {
 591                         .parent       = root,
 592                         .dir_ni       = ni,
 593                         .path         = path,
 594                         .path_len     = path_len,
 595                         .lookup_table = lookup_table,
 596                         .sd_set       = sd_set,
 597                         .config       = config,
 598                         .ntfs_vol_p   = ntfs_vol_p,
 599                         .flags        = flags,
 600                 };
 601                 ret = ntfs_readdir(ni, &pos, &ctx, wim_ntfs_capture_filldir);
 602                 if (ret != 0) {
 603                         ERROR_WITH_ERRNO("ntfs_readdir()");
 604                         ret = WIMLIB_ERR_NTFS_3G;
 605                 }
 606         } else {
 607                 /* Normal file */
 608                 ret = capture_ntfs_streams(root, ni, path, path_len,
 609                                            lookup_table, ntfs_vol_p,
 610                                            AT_DATA);
 611         }
 612         if (ret != 0)
 613                 return ret;
 614
 615         char _sd[1];
 616         char *sd = _sd;
 617         errno = 0;
 618         ret = ntfs_xattr_system_getxattr(&ctx, XATTR_NTFS_ACL,
 619                                          ni, dir_ni, sd,
 620                                          sizeof(sd));
 621         if (ret > sizeof(sd)) {
 622                 sd = alloca(ret);
 623                 ret = ntfs_xattr_system_getxattr(&ctx, XATTR_NTFS_ACL,
 624                                                  ni, dir_ni, sd, ret);
 625         }
 626         if (ret > 0) {
 627                 root->d_inode->security_id = sd_set_add_sd(sd_set, sd, ret);
 628                 if (root->d_inode->security_id == -1) {
 629                         ERROR("Out of memory");
 630                         return WIMLIB_ERR_NOMEM;
 631                 }
 632                 DEBUG("Added security ID = %u for `%s'",
 633                       root->d_inode->security_id, path);
 634                 ret = 0;
 635         } else if (ret < 0) {
 636                 ERROR_WITH_ERRNO("Failed to get security information from "
 637                                  "`%s'", path);
 638                 ret = WIMLIB_ERR_NTFS_3G;
 639         } else {
 640                 root->d_inode->security_id = -1;
 641                 DEBUG("No security ID for `%s'", path);
 642         }
 643         return ret;
 644 }
 645
 646 int build_dentry_tree_ntfs(struct dentry **root_p,
 647                            const char *device,
 648                            struct lookup_table *lookup_table,
 649                            struct wim_security_data *sd,
 650                            const struct capture_config *config,
 651                            int flags,
 652                            void *extra_arg)
 653 {
 654         ntfs_volume *vol;
 655         ntfs_inode *root_ni;
 656         int ret = 0;
 657         struct sd_set sd_set = {
 658                 .sd = sd,
 659                 .root = NULL,
 660         };
 661         ntfs_volume **ntfs_vol_p = extra_arg;
 662
 663         DEBUG("Mounting NTFS volume `%s' read-only", device);
 664
 665         vol = ntfs_mount(device, MS_RDONLY);
 666         if (!vol) {
 667                 ERROR_WITH_ERRNO("Failed to mount NTFS volume `%s' read-only",
 668                                  device);
 669                 return WIMLIB_ERR_NTFS_3G;
 670         }
 671         ntfs_open_secure(vol);
 672
 673         /* We don't want to capture the special NTFS files such as $Bitmap.  Not
 674          * to be confused with "hidden" or "system" files which are real files
 675          * that we do need to capture.  */
 676         NVolClearShowSysFiles(vol);
 677
 678         DEBUG("Opening root NTFS dentry");
 679         root_ni = ntfs_inode_open(vol, FILE_root);
 680         if (!root_ni) {
 681                 ERROR_WITH_ERRNO("Failed to open root inode of NTFS volume "
 682                                  "`%s'", device);
 683                 ret = WIMLIB_ERR_NTFS_3G;
 684                 goto out;
 685         }
 686
 687         /* Currently we assume that all the UTF-8 paths fit into this length and
 688          * there is no check for overflow. */
 689         char *path = MALLOC(32768);
 690         if (!path) {
 691                 ERROR("Could not allocate memory for NTFS pathname");
 692                 goto out_cleanup;
 693         }
 694
 695         path[0] = '/';
 696         path[1] = '\0';
 697         ret = build_dentry_tree_ntfs_recursive(root_p, NULL, root_ni, path, 1,
 698                                                FILE_NAME_POSIX, lookup_table,
 699                                                &sd_set, config, ntfs_vol_p,
 700                                                flags);
 701 out_cleanup:
 702         FREE(path);
 703         ntfs_inode_close(root_ni);
 704         destroy_sd_set(&sd_set);
 705
 706 out:
 707         if (ret) {
 708                 if (ntfs_umount(vol, FALSE) != 0) {
 709                         ERROR_WITH_ERRNO("Failed to unmount NTFS volume `%s'",
 710                                          device);
 711                         if (ret == 0)
 712                                 ret = WIMLIB_ERR_NTFS_3G;
 713                 }
 714         } else {
 715                 /* We need to leave the NTFS volume mounted so that we can read
 716                  * the NTFS files again when we are actually writing the WIM */
 717                 *ntfs_vol_p = vol;
 718         }
 719         return ret;
 720 }