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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 #ifdef WITH_NTFS_3G
  31 #include <ntfs-3g/endians.h>
  32 #include <ntfs-3g/types.h>
  33 #endif
  34
  35 #include "wimlib_internal.h"
  36
  37
  38 #ifdef WITH_NTFS_3G
  39 #include "dentry.h"
  40 #include "lookup_table.h"
  41 #include "io.h"
  42 #include <ntfs-3g/layout.h>
  43 #include <ntfs-3g/acls.h>
  44 #include <ntfs-3g/attrib.h>
  45 #include <ntfs-3g/misc.h>
  46 #include <ntfs-3g/reparse.h>
  47 #include <ntfs-3g/security.h> /* security.h before xattrs.h */
  48 #include <ntfs-3g/xattrs.h>
  49 #include <ntfs-3g/volume.h>
  50 #include <stdlib.h>
  51 #include <unistd.h>
  52 #include <errno.h>
  53
  54 /* Structure that allows searching the security descriptors by SHA1 message
  55  * digest. */
  56 struct sd_set {
  57         struct wim_security_data *sd;
  58         struct sd_node *root;
  59 };
  60
  61 /* Binary tree node of security descriptors, indexed by the @hash field. */
  62 struct sd_node {
  63         int security_id;
  64         u8 hash[SHA1_HASH_SIZE];
  65         struct sd_node *left;
  66         struct sd_node *right;
  67 };
  68
  69 static void free_sd_tree(struct sd_node *root)
  70 {
  71         if (root) {
  72                 free_sd_tree(root->left);
  73                 free_sd_tree(root->right);
  74                 FREE(root);
  75         }
  76 }
  77 /* Frees a security descriptor index set. */
  78 static void destroy_sd_set(struct sd_set *sd_set)
  79 {
  80         free_sd_tree(sd_set->root);
  81 }
  82
  83 /* Inserts a a new node into the security descriptor index tree. */
  84 static void insert_sd_node(struct sd_node *new, struct sd_node *root)
  85 {
  86         int cmp = hashes_cmp(new->hash, root->hash);
  87         if (cmp < 0) {
  88                 if (root->left)
  89                         insert_sd_node(new, root->left);
  90                 else
  91                         root->left = new;
  92         } else if (cmp > 0) {
  93                 if (root->right)
  94                         insert_sd_node(new, root->right);
  95                 else
  96                         root->right = new;
  97         } else {
  98                 wimlib_assert(0);
  99         }
 100 }
 101
 102 /* Returns the security ID of the security data having a SHA1 message digest of
 103  * @hash in the security descriptor index tree rooted at @root.
 104  *
 105  * If not found, return -1. */
 106 static int lookup_sd(const u8 hash[SHA1_HASH_SIZE], struct sd_node *root)
 107 {
 108         int cmp;
 109         if (!root)
 110                 return -1;
 111         cmp = hashes_cmp(hash, root->hash);
 112         if (cmp < 0)
 113                 return lookup_sd(hash, root->left);
 114         else if (cmp > 0)
 115                 return lookup_sd(hash, root->right);
 116         else
 117                 return root->security_id;
 118 }
 119
 120 /*
 121  * Adds a security descriptor to the indexed security descriptor set as well as
 122  * the corresponding `struct wim_security_data', and returns the new security
 123  * ID; or, if there is an existing security descriptor that is the same, return
 124  * the security ID for it.  If a new security descriptor cannot be allocated,
 125  * return -1.
 126  */
 127 static int sd_set_add_sd(struct sd_set *sd_set, const char descriptor[],
 128                          size_t size)
 129 {
 130         u8 hash[SHA1_HASH_SIZE];
 131         int security_id;
 132         struct sd_node *new;
 133         u8 **descriptors;
 134         u64 *sizes;
 135         u8 *descr_copy;
 136         struct wim_security_data *sd;
 137
 138         sha1_buffer((const u8*)descriptor, size, hash);
 139
 140         security_id = lookup_sd(hash, sd_set->root);
 141         if (security_id >= 0)
 142                 return security_id;
 143
 144         new = MALLOC(sizeof(*new));
 145         if (!new)
 146                 goto out;
 147         descr_copy = MALLOC(size);
 148         if (!descr_copy)
 149                 goto out_free_node;
 150
 151         sd = sd_set->sd;
 152
 153         memcpy(descr_copy, descriptor, size);
 154         new->security_id = sd->num_entries;
 155         new->left = NULL;
 156         new->right = NULL;
 157         copy_hash(new->hash, hash);
 158
 159
 160         descriptors = REALLOC(sd->descriptors,
 161                               (sd->num_entries + 1) * sizeof(sd->descriptors[0]));
 162         if (!descriptors)
 163                 goto out_free_descr;
 164         sd->descriptors = descriptors;
 165         sizes = REALLOC(sd->sizes,
 166                         (sd->num_entries + 1) * sizeof(sd->sizes[0]));
 167         if (!sizes)
 168                 goto out_free_descr;
 169         sd->sizes = sizes;
 170         sd->descriptors[sd->num_entries] = descr_copy;
 171         sd->sizes[sd->num_entries] = size;
 172         sd->num_entries++;
 173         DEBUG("There are now %d security descriptors", sd->num_entries);
 174         sd->total_length += size + sizeof(sd->sizes[0]);
 175
 176         if (sd_set->root)
 177                 insert_sd_node(new, sd_set->root);
 178         else
 179                 sd_set->root = new;
 180         return new->security_id;
 181 out_free_descr:
 182         FREE(descr_copy);
 183 out_free_node:
 184         FREE(new);
 185 out:
 186         return -1;
 187 }
 188
 189 static inline ntfschar *attr_record_name(ATTR_RECORD *ar)
 190 {
 191         return (ntfschar*)((u8*)ar + le16_to_cpu(ar->name_offset));
 192 }
 193
 194 /* Calculates the SHA1 message digest of a NTFS attribute.
 195  *
 196  * @ni:  The NTFS inode containing the attribute.
 197  * @ar:  The ATTR_RECORD describing the attribute.
 198  * @md:  If successful, the returned SHA1 message digest.
 199  * @reparse_tag_ret:    Optional pointer into which the first 4 bytes of the
 200  *                              attribute will be written (to get the reparse
 201  *                              point ID)
 202  *
 203  * Return 0 on success or nonzero on error.
 204  */
 205 static int ntfs_attr_sha1sum(ntfs_inode *ni, ATTR_RECORD *ar,
 206                              u8 md[SHA1_HASH_SIZE],
 207                              bool is_reparse_point,
 208                              u32 *reparse_tag_ret)
 209 {
 210         s64 pos = 0;
 211         s64 bytes_remaining;
 212         char buf[BUFFER_SIZE];
 213         ntfs_attr *na;
 214         SHA_CTX ctx;
 215
 216         na = ntfs_attr_open(ni, ar->type, attr_record_name(ar),
 217                             ar->name_length);
 218         if (!na) {
 219                 ERROR_WITH_ERRNO("Failed to open NTFS attribute");
 220                 return WIMLIB_ERR_NTFS_3G;
 221         }
 222
 223         bytes_remaining = na->data_size;
 224
 225         if (is_reparse_point) {
 226                 if (ntfs_attr_pread(na, 0, 8, buf) != 8)
 227                         goto out_error;
 228                 *reparse_tag_ret = le32_to_cpu(*(u32*)buf);
 229                 pos = 8;
 230                 bytes_remaining -= 8;
 231         }
 232
 233         sha1_init(&ctx);
 234         while (bytes_remaining) {
 235                 s64 to_read = min(bytes_remaining, sizeof(buf));
 236                 if (ntfs_attr_pread(na, pos, to_read, buf) != to_read)
 237                         goto out_error;
 238                 sha1_update(&ctx, buf, to_read);
 239                 pos += to_read;
 240                 bytes_remaining -= to_read;
 241         }
 242         sha1_final(md, &ctx);
 243         ntfs_attr_close(na);
 244         return 0;
 245 out_error:
 246         ERROR_WITH_ERRNO("Error reading NTFS attribute");
 247         return WIMLIB_ERR_NTFS_3G;
 248 }
 249
 250 /* Load the streams from a file or reparse point in the NTFS volume into the WIM
 251  * lookup table */
 252 static int capture_ntfs_streams(struct dentry *dentry, ntfs_inode *ni,
 253                                 char path[], size_t path_len,
 254                                 struct lookup_table *lookup_table,
 255                                 ntfs_volume **ntfs_vol_p,
 256                                 ATTR_TYPES type)
 257 {
 258         ntfs_attr_search_ctx *actx;
 259         u8 attr_hash[SHA1_HASH_SIZE];
 260         struct ntfs_location *ntfs_loc = NULL;
 261         int ret = 0;
 262         struct lookup_table_entry *lte;
 263
 264         DEBUG2("Capturing NTFS data streams from `%s'", path);
 265
 266         /* Get context to search the streams of the NTFS file. */
 267         actx = ntfs_attr_get_search_ctx(ni, NULL);
 268         if (!actx) {
 269                 ERROR_WITH_ERRNO("Cannot get NTFS attribute search "
 270                                  "context");
 271                 return WIMLIB_ERR_NTFS_3G;
 272         }
 273
 274         /* Capture each data stream or reparse data stream. */
 275         while (!ntfs_attr_lookup(type, NULL, 0,
 276                                  CASE_SENSITIVE, 0, NULL, 0, actx))
 277         {
 278                 char *stream_name_utf8;
 279                 u32 reparse_tag;
 280                 u64 data_size = ntfs_get_attribute_value_length(actx->attr);
 281                 u64 name_length = actx->attr->name_length;
 282
 283                 if (data_size == 0) {
 284                         if (errno != 0) {
 285                                 ERROR_WITH_ERRNO("Failed to get size of attribute of "
 286                                                  "`%s'", path);
 287                                 ret = WIMLIB_ERR_NTFS_3G;
 288                                 goto out_put_actx;
 289                         }
 290                         /* Empty stream.  No lookup table entry is needed. */
 291                         lte = NULL;
 292                 } else {
 293                         if (type == AT_REPARSE_POINT && data_size < 8) {
 294                                 ERROR("`%s': reparse point buffer too small",
 295                                       path);
 296                                 ret = WIMLIB_ERR_NTFS_3G;
 297                                 goto out_put_actx;
 298                         }
 299                         /* Checksum the stream. */
 300                         ret = ntfs_attr_sha1sum(ni, actx->attr, attr_hash,
 301                                                 type == AT_REPARSE_POINT, &reparse_tag);
 302                         if (ret != 0)
 303                                 goto out_put_actx;
 304
 305                         /* Make a lookup table entry for the stream, or use an existing
 306                          * one if there's already an identical stream. */
 307                         lte = __lookup_resource(lookup_table, attr_hash);
 308                         ret = WIMLIB_ERR_NOMEM;
 309                         if (lte) {
 310                                 lte->refcnt++;
 311                         } else {
 312                                 ntfs_loc = CALLOC(1, sizeof(*ntfs_loc));
 313                                 if (!ntfs_loc)
 314                                         goto out_put_actx;
 315                                 ntfs_loc->ntfs_vol_p = ntfs_vol_p;
 316                                 ntfs_loc->path_utf8 = MALLOC(path_len + 1);
 317                                 if (!ntfs_loc->path_utf8)
 318                                         goto out_free_ntfs_loc;
 319                                 memcpy(ntfs_loc->path_utf8, path, path_len + 1);
 320                                 if (name_length) {
 321                                         ntfs_loc->stream_name_utf16 = MALLOC(name_length * 2);
 322                                         if (!ntfs_loc->stream_name_utf16)
 323                                                 goto out_free_ntfs_loc;
 324                                         memcpy(ntfs_loc->stream_name_utf16,
 325                                                attr_record_name(actx->attr),
 326                                                actx->attr->name_length * 2);
 327                                         ntfs_loc->stream_name_utf16_num_chars = name_length;
 328                                 }
 329
 330                                 lte = new_lookup_table_entry();
 331                                 if (!lte)
 332                                         goto out_free_ntfs_loc;
 333                                 lte->ntfs_loc = ntfs_loc;
 334                                 lte->resource_location = RESOURCE_IN_NTFS_VOLUME;
 335                                 if (type == AT_REPARSE_POINT) {
 336                                         dentry->d_inode->reparse_tag = reparse_tag;
 337                                         ntfs_loc->is_reparse_point = true;
 338                                         lte->resource_entry.original_size = data_size - 8;
 339                                         lte->resource_entry.size = data_size - 8;
 340                                 } else {
 341                                         ntfs_loc->is_reparse_point = false;
 342                                         lte->resource_entry.original_size = data_size;
 343                                         lte->resource_entry.size = data_size;
 344                                 }
 345                                 ntfs_loc = NULL;
 346                                 DEBUG("Add resource for `%s' (size = %zu)",
 347                                       dentry->file_name_utf8,
 348                                       lte->resource_entry.original_size);
 349                                 copy_hash(lte->hash, attr_hash);
 350                                 lookup_table_insert(lookup_table, lte);
 351                         }
 352                 }
 353                 if (name_length == 0) {
 354                         /* Unnamed data stream.  Put the reference to it in the
 355                          * dentry's inode. */
 356                         if (dentry->d_inode->lte) {
 357                                 ERROR("Found two un-named data streams for "
 358                                       "`%s'", path);
 359                                 ret = WIMLIB_ERR_NTFS_3G;
 360                                 goto out_free_lte;
 361                         }
 362                         dentry->d_inode->lte = lte;
 363                 } else {
 364                         /* Named data stream.  Put the reference to it in the
 365                          * alternate data stream entries */
 366                         struct ads_entry *new_ads_entry;
 367                         size_t stream_name_utf8_len;
 368                         stream_name_utf8 = utf16_to_utf8((const char*)attr_record_name(actx->attr),
 369                                                          name_length * 2,
 370                                                          &stream_name_utf8_len);
 371                         if (!stream_name_utf8)
 372                                 goto out_free_lte;
 373                         new_ads_entry = inode_add_ads(dentry->d_inode, stream_name_utf8);
 374                         FREE(stream_name_utf8);
 375                         if (!new_ads_entry)
 376                                 goto out_free_lte;
 377
 378                         wimlib_assert(new_ads_entry->stream_name_len == name_length * 2);
 379
 380                         new_ads_entry->lte = lte;
 381                 }
 382         }
 383         ret = 0;
 384         goto out_put_actx;
 385 out_free_lte:
 386         free_lookup_table_entry(lte);
 387 out_free_ntfs_loc:
 388         if (ntfs_loc) {
 389                 FREE(ntfs_loc->path_utf8);
 390                 FREE(ntfs_loc->stream_name_utf16);
 391                 FREE(ntfs_loc);
 392         }
 393 out_put_actx:
 394         ntfs_attr_put_search_ctx(actx);
 395         if (ret == 0)
 396                 DEBUG2("Successfully captured NTFS streams from `%s'", path);
 397         else
 398                 ERROR("Failed to capture NTFS streams from `%s", path);
 399         return ret;
 400 }
 401
 402 struct readdir_ctx {
 403         struct dentry       *parent;
 404         ntfs_inode          *dir_ni;
 405         char                *path;
 406         size_t               path_len;
 407         struct lookup_table *lookup_table;
 408         struct sd_set       *sd_set;
 409         const struct capture_config *config;
 410         ntfs_volume        **ntfs_vol_p;
 411         int                  flags;
 412 };
 413
 414 static int
 415 build_dentry_tree_ntfs_recursive(struct dentry **root_p, ntfs_inode *dir_ni,
 416                                  ntfs_inode *ni, char path[], size_t path_len,
 417                                  int name_type,
 418                                  struct lookup_table *lookup_table,
 419                                  struct sd_set *sd_set,
 420                                  const struct capture_config *config,
 421                                  ntfs_volume **ntfs_vol_p,
 422                                  int flags);
 423
 424 static int wim_ntfs_capture_filldir(void *dirent, const ntfschar *name,
 425                                     const int name_len, const int name_type,
 426                                     const s64 pos, const MFT_REF mref,
 427                                     const unsigned dt_type)
 428 {
 429         struct readdir_ctx *ctx;
 430         size_t utf8_name_len;
 431         char *utf8_name;
 432         struct dentry *child = NULL;
 433         int ret;
 434         size_t path_len;
 435
 436         if (name_type == FILE_NAME_DOS)
 437                 return 0;
 438
 439         ret = -1;
 440
 441         utf8_name = utf16_to_utf8((const char*)name, name_len * 2,
 442                                   &utf8_name_len);
 443         if (!utf8_name)
 444                 goto out;
 445
 446         if (utf8_name[0] == '.' &&
 447              (utf8_name[1] == '\0' ||
 448               (utf8_name[1] == '.' && utf8_name[2] == '\0'))) {
 449                 ret = 0;
 450                 goto out_free_utf8_name;
 451         }
 452
 453         ctx = dirent;
 454
 455         ntfs_inode *ni = ntfs_inode_open(ctx->dir_ni->vol, mref);
 456         if (!ni) {
 457                 ERROR_WITH_ERRNO("Failed to open NTFS inode");
 458                 goto out_free_utf8_name;
 459         }
 460         path_len = ctx->path_len;
 461         if (path_len != 1)
 462                 ctx->path[path_len++] = '/';
 463         memcpy(ctx->path + path_len, utf8_name, utf8_name_len + 1);
 464         path_len += utf8_name_len;
 465         ret = build_dentry_tree_ntfs_recursive(&child, ctx->dir_ni,
 466                                                ni, ctx->path, path_len, name_type,
 467                                                ctx->lookup_table, ctx->sd_set,
 468                                                ctx->config, ctx->ntfs_vol_p,
 469                                                ctx->flags);
 470
 471         if (child)
 472                 dentry_add_child(ctx->parent, child);
 473
 474         ntfs_inode_close(ni);
 475 out_free_utf8_name:
 476         FREE(utf8_name);
 477 out:
 478         return ret;
 479 }
 480
 481 static int change_dentry_short_name(struct dentry *dentry,
 482                                     const char short_name_utf8[],
 483                                     int short_name_utf8_len)
 484 {
 485         size_t short_name_utf16_len;
 486         char *short_name_utf16;
 487         short_name_utf16 = utf8_to_utf16(short_name_utf8, short_name_utf8_len,
 488                                          &short_name_utf16_len);
 489         if (!short_name_utf16) {
 490                 ERROR_WITH_ERRNO("Failed to convert short name to UTF-16");
 491                 return WIMLIB_ERR_NOMEM;
 492         }
 493         dentry->short_name = short_name_utf16;
 494         dentry->short_name_len = short_name_utf16_len;
 495         return 0;
 496 }
 497
 498 /* Recursively build a WIM dentry tree corresponding to a NTFS volume.
 499  * At the same time, update the WIM lookup table with lookup table entries for
 500  * the NTFS streams, and build an array of security descriptors.
 501  */
 502 static int build_dentry_tree_ntfs_recursive(struct dentry **root_p,
 503                                             ntfs_inode *dir_ni,
 504                                             ntfs_inode *ni,
 505                                             char path[],
 506                                             size_t path_len,
 507                                             int name_type,
 508                                             struct lookup_table *lookup_table,
 509                                             struct sd_set *sd_set,
 510                                             const struct capture_config *config,
 511                                             ntfs_volume **ntfs_vol_p,
 512                                             int flags)
 513 {
 514         u32 attributes;
 515         int mrec_flags;
 516         int ret;
 517         char dos_name_utf8[64];
 518         struct dentry *root;
 519
 520         mrec_flags = ni->mrec->flags;
 521         struct SECURITY_CONTEXT ctx;
 522         memset(&ctx, 0, sizeof(ctx));
 523         ctx.vol = ni->vol;
 524         ret = ntfs_xattr_system_getxattr(&ctx, XATTR_NTFS_ATTRIB,
 525                                          ni, dir_ni, (char *)&attributes,
 526                                          sizeof(u32));
 527         if (ret != 4) {
 528                 ERROR_WITH_ERRNO("Failed to get NTFS attributes from `%s'",
 529                                  path);
 530                 return WIMLIB_ERR_NTFS_3G;
 531         }
 532
 533         if (exclude_path(path, config, false)) {
 534                 if (flags & WIMLIB_ADD_IMAGE_FLAG_VERBOSE) {
 535                         const char *file_type;
 536                         if (attributes & MFT_RECORD_IS_DIRECTORY)
 537                                 file_type = "directory";
 538                         else
 539                                 file_type = "file";
 540                         printf("Excluding %s `%s' from capture\n",
 541                                file_type, path);
 542                 }
 543                 *root_p = NULL;
 544                 return 0;
 545         }
 546
 547         if (flags & WIMLIB_ADD_IMAGE_FLAG_VERBOSE)
 548                 printf("Scanning `%s'\n", path);
 549
 550         root = new_dentry_with_timeless_inode(path_basename(path));
 551         if (!root)
 552                 return WIMLIB_ERR_NOMEM;
 553         *root_p = root;
 554
 555         if (dir_ni && (name_type == FILE_NAME_WIN32_AND_DOS
 556                        || name_type == FILE_NAME_WIN32))
 557         {
 558                 ret = ntfs_get_ntfs_dos_name(ni, dir_ni, dos_name_utf8,
 559                                              sizeof(dos_name_utf8));
 560                 if (ret > 0) {
 561                         DEBUG("Changing short name of `%s'", path);
 562                         ret = change_dentry_short_name(root, dos_name_utf8,
 563                                                        ret);
 564                         if (ret != 0)
 565                                 return ret;
 566                 } else {
 567                 #ifdef ENODATA
 568                         if (errno != ENODATA) {
 569                                 ERROR_WITH_ERRNO("Error getting DOS name "
 570                                                  "of `%s'", path);
 571                                 return WIMLIB_ERR_NTFS_3G;
 572                         }
 573                 #endif
 574                 }
 575         }
 576
 577         root->d_inode->creation_time    = le64_to_cpu(ni->creation_time);
 578         root->d_inode->last_write_time  = le64_to_cpu(ni->last_data_change_time);
 579         root->d_inode->last_access_time = le64_to_cpu(ni->last_access_time);
 580         root->d_inode->attributes       = le32_to_cpu(attributes);
 581         root->d_inode->ino              = ni->mft_no;
 582         root->d_inode->resolved         = true;
 583
 584         if (attributes & FILE_ATTR_REPARSE_POINT) {
 585                 /* Junction point, symbolic link, or other reparse point */
 586                 ret = capture_ntfs_streams(root, ni, path, path_len,
 587                                            lookup_table, ntfs_vol_p,
 588                                            AT_REPARSE_POINT);
 589         } else if (mrec_flags & MFT_RECORD_IS_DIRECTORY) {
 590
 591                 /* Normal directory */
 592                 s64 pos = 0;
 593                 struct readdir_ctx ctx = {
 594                         .parent       = root,
 595                         .dir_ni       = ni,
 596                         .path         = path,
 597                         .path_len     = path_len,
 598                         .lookup_table = lookup_table,
 599                         .sd_set       = sd_set,
 600                         .config       = config,
 601                         .ntfs_vol_p   = ntfs_vol_p,
 602                         .flags        = flags,
 603                 };
 604                 ret = ntfs_readdir(ni, &pos, &ctx, wim_ntfs_capture_filldir);
 605                 if (ret != 0) {
 606                         ERROR_WITH_ERRNO("ntfs_readdir()");
 607                         ret = WIMLIB_ERR_NTFS_3G;
 608                 }
 609         } else {
 610                 /* Normal file */
 611                 ret = capture_ntfs_streams(root, ni, path, path_len,
 612                                            lookup_table, ntfs_vol_p,
 613                                            AT_DATA);
 614         }
 615         if (ret != 0)
 616                 return ret;
 617
 618         char _sd[1];
 619         char *sd = _sd;
 620         errno = 0;
 621         ret = ntfs_xattr_system_getxattr(&ctx, XATTR_NTFS_ACL,
 622                                          ni, dir_ni, sd,
 623                                          sizeof(sd));
 624         if (ret > sizeof(sd)) {
 625                 sd = alloca(ret);
 626                 ret = ntfs_xattr_system_getxattr(&ctx, XATTR_NTFS_ACL,
 627                                                  ni, dir_ni, sd, ret);
 628         }
 629         if (ret > 0) {
 630                 root->d_inode->security_id = sd_set_add_sd(sd_set, sd, ret);
 631                 if (root->d_inode->security_id == -1) {
 632                         ERROR("Out of memory");
 633                         return WIMLIB_ERR_NOMEM;
 634                 }
 635                 DEBUG("Added security ID = %u for `%s'",
 636                       root->d_inode->security_id, path);
 637                 ret = 0;
 638         } else if (ret < 0) {
 639                 ERROR_WITH_ERRNO("Failed to get security information from "
 640                                  "`%s'", path);
 641                 ret = WIMLIB_ERR_NTFS_3G;
 642         } else {
 643                 root->d_inode->security_id = -1;
 644                 DEBUG("No security ID for `%s'", path);
 645         }
 646         return ret;
 647 }
 648
 649 static int build_dentry_tree_ntfs(struct dentry **root_p,
 650                                   const char *device,
 651                                   struct lookup_table *lookup_table,
 652                                   struct wim_security_data *sd,
 653                                   const struct capture_config *config,
 654                                   int flags,
 655                                   void *extra_arg)
 656 {
 657         ntfs_volume *vol;
 658         ntfs_inode *root_ni;
 659         int ret = 0;
 660         struct sd_set sd_set = {
 661                 .sd = sd,
 662                 .root = NULL,
 663         };
 664         ntfs_volume **ntfs_vol_p = extra_arg;
 665
 666         DEBUG("Mounting NTFS volume `%s' read-only", device);
 667
 668         vol = ntfs_mount(device, MS_RDONLY);
 669         if (!vol) {
 670                 ERROR_WITH_ERRNO("Failed to mount NTFS volume `%s' read-only",
 671                                  device);
 672                 return WIMLIB_ERR_NTFS_3G;
 673         }
 674         ntfs_open_secure(vol);
 675
 676         /* We don't want to capture the special NTFS files such as $Bitmap.  Not
 677          * to be confused with "hidden" or "system" files which are real files
 678          * that we do need to capture.  */
 679         NVolClearShowSysFiles(vol);
 680
 681         DEBUG("Opening root NTFS dentry");
 682         root_ni = ntfs_inode_open(vol, FILE_root);
 683         if (!root_ni) {
 684                 ERROR_WITH_ERRNO("Failed to open root inode of NTFS volume "
 685                                  "`%s'", device);
 686                 ret = WIMLIB_ERR_NTFS_3G;
 687                 goto out;
 688         }
 689
 690         /* Currently we assume that all the UTF-8 paths fit into this length and
 691          * there is no check for overflow. */
 692         char *path = MALLOC(32768);
 693         if (!path) {
 694                 ERROR("Could not allocate memory for NTFS pathname");
 695                 goto out_cleanup;
 696         }
 697
 698         path[0] = '/';
 699         path[1] = '\0';
 700         ret = build_dentry_tree_ntfs_recursive(root_p, NULL, root_ni, path, 1,
 701                                                FILE_NAME_POSIX, lookup_table,
 702                                                &sd_set, config, ntfs_vol_p,
 703                                                flags);
 704 out_cleanup:
 705         FREE(path);
 706         ntfs_inode_close(root_ni);
 707         destroy_sd_set(&sd_set);
 708
 709 out:
 710         if (ret) {
 711                 if (ntfs_umount(vol, FALSE) != 0) {
 712                         ERROR_WITH_ERRNO("Failed to unmount NTFS volume `%s'",
 713                                          device);
 714                         if (ret == 0)
 715                                 ret = WIMLIB_ERR_NTFS_3G;
 716                 }
 717         } else {
 718                 /* We need to leave the NTFS volume mounted so that we can read
 719                  * the NTFS files again when we are actually writing the WIM */
 720                 *ntfs_vol_p = vol;
 721         }
 722         return ret;
 723 }
 724
 725
 726
 727 WIMLIBAPI int wimlib_add_image_from_ntfs_volume(WIMStruct *w,
 728                                                 const char *device,
 729                                                 const char *name,
 730                                                 const char *config_str,
 731                                                 size_t config_len,
 732                                                 int flags)
 733 {
 734         if (flags & (WIMLIB_ADD_IMAGE_FLAG_DEREFERENCE)) {
 735                 ERROR("Cannot dereference files when capturing directly from NTFS");
 736                 return WIMLIB_ERR_INVALID_PARAM;
 737         }
 738         return do_add_image(w, device, name, config_str, config_len, flags,
 739                             build_dentry_tree_ntfs, &w->ntfs_vol);
 740 }
 741
 742 #else /* WITH_NTFS_3G */
 743 WIMLIBAPI int wimlib_add_image_from_ntfs_volume(WIMStruct *w,
 744                                                 const char *device,
 745                                                 const char *name,
 746                                                 const char *config_str,
 747                                                 size_t config_len,
 748                                                 int flags)
 749 {
 750         ERROR("wimlib was compiled without support for NTFS-3g, so");
 751         ERROR("we cannot capture a WIM image directly from a NTFS volume");
 752         return WIMLIB_ERR_UNSUPPORTED;
 753 }
 754 #endif /* WITH_NTFS_3G */