-
-/*
- * Reads the metadata metadata resource from the WIM file. The metadata
- * resource consists of the security data, followed by the directory entry for
- * the root directory, followed by all the other directory entries in the
- * filesystem. The subdir_offset field of each directory entry gives the start
- * of its child entries from the beginning of the metadata resource. An
- * end-of-directory is signaled by a directory entry of length '0', really of
- * length 8, because that's how long the 'length' field is.
- *
- * @fp: The FILE* for the input WIM file.
- * @wim_ctype: The compression type of the WIM file.
- * @imd: Pointer to the image metadata structure. Its `metadata_lte'
- * member specifies the lookup table entry for the metadata
- * resource. The rest of the image metadata entry will be filled
- * in by this function.
- *
- * @return: Zero on success, nonzero on failure.
- */
-int read_metadata_resource(WIMStruct *w, struct image_metadata *imd)
-{
- u8 *buf;
- u32 dentry_offset;
- int ret;
- struct dentry *dentry;
- struct inode_table inode_tab;
- const struct lookup_table_entry *metadata_lte;
- u64 metadata_len;
- struct hlist_head inode_list;
-
- metadata_lte = imd->metadata_lte;
- metadata_len = wim_resource_size(metadata_lte);
-
- DEBUG("Reading metadata resource: length = %"PRIu64", "
- "offset = %"PRIu64"", metadata_len,
- metadata_lte->resource_entry.offset);
-
- /* There is no way the metadata resource could possibly be less than (8
- * + WIM_DENTRY_DISK_SIZE) bytes, where the 8 is for security data (with
- * no security descriptors) and WIM_DENTRY_DISK_SIZE is for the root
- * dentry. */
- if (metadata_len < 8 + WIM_DENTRY_DISK_SIZE) {
- ERROR("Expected at least %u bytes for the metadata resource",
- 8 + WIM_DENTRY_DISK_SIZE);
- return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
- }
-
- if (sizeof(size_t) < 8 && metadata_len > 0xffffffff) {
- ERROR("Metadata resource is too large (%"PRIu64" bytes",
- metadata_len);
- return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
- }
-
- /* Allocate memory for the uncompressed metadata resource. */
- buf = MALLOC(metadata_len);
-
- if (!buf) {
- ERROR("Failed to allocate %"PRIu64" bytes for uncompressed "
- "metadata resource", metadata_len);
- return WIMLIB_ERR_NOMEM;
- }
-
- /* Read the metadata resource into memory. (It may be compressed.) */
- ret = read_full_wim_resource(metadata_lte, buf, 0);
- if (ret != 0)
- goto out_free_buf;
-
- DEBUG("Finished reading metadata resource into memory.");
-
- /* The root directory entry starts after security data, aligned on an
- * 8-byte boundary within the metadata resource.
- *
- * The security data starts with a 4-byte integer giving its total
- * length, so if we round that up to an 8-byte boundary that gives us
- * the offset of the root dentry.
- *
- * Here we read the security data into a wim_security_data structure,
- * and if successful, go ahead and calculate the offset in the metadata
- * resource of the root dentry. */
-
- wimlib_assert(imd->security_data == NULL);
- ret = read_security_data(buf, metadata_len, &imd->security_data);
- if (ret != 0)
- goto out_free_buf;
-
- dentry_offset = (imd->security_data->total_length + 7) & ~7;
-
- if (dentry_offset == 0) {
- ERROR("Integer overflow while reading metadata resource");
- ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
- goto out_free_security_data;
- }
-
- DEBUG("Reading root dentry");
-
- /* Allocate memory for the root dentry and read it into memory */
- dentry = MALLOC(sizeof(struct dentry));
- if (!dentry) {
- ERROR("Failed to allocate %zu bytes for root dentry",
- sizeof(struct dentry));
- ret = WIMLIB_ERR_NOMEM;
- goto out_free_security_data;
- }
-
- ret = read_dentry(buf, metadata_len, dentry_offset, dentry);
-
- /* This is the root dentry, so set its parent to itself. */
- dentry->parent = dentry;
-
- if (ret == 0 && dentry->length == 0) {
- ERROR("Metadata resource cannot begin with end-of-directory entry!");
- ret = WIMLIB_ERR_INVALID_DENTRY;
- }
-
- if (ret != 0) {
- FREE(dentry);
- goto out_free_security_data;
- }
-
- inode_add_dentry(dentry, dentry->d_inode);
-
- /* Now read the entire directory entry tree into memory. */
- DEBUG("Reading dentry tree");
- ret = read_dentry_tree(buf, metadata_len, dentry);
- if (ret != 0)
- goto out_free_dentry_tree;
-
- /* Calculate the full paths in the dentry tree. */
- DEBUG("Calculating dentry full paths");
- ret = for_dentry_in_tree(dentry, calculate_dentry_full_path, NULL);
- if (ret != 0)
- goto out_free_dentry_tree;
-
- /* Build hash table that maps hard link group IDs to dentry sets */
- DEBUG("Building link group table");
- ret = init_inode_table(&inode_tab, 9001);
- if (ret != 0)
- goto out_free_dentry_tree;
-
- for_dentry_in_tree(dentry, inode_table_insert, &inode_tab);
-
- DEBUG("Fixing inconsistencies in the hard link groups");
- ret = fix_inodes(&inode_tab, &inode_list);
- destroy_inode_table(&inode_tab);
- if (ret != 0)
- goto out_free_dentry_tree;
-
- if (!w->all_images_verified) {
- DEBUG("Running miscellaneous verifications on the dentry tree");
- for_lookup_table_entry(w->lookup_table, lte_zero_real_refcnt, NULL);
- ret = for_dentry_in_tree(dentry, verify_dentry, w);
- if (ret != 0)
- goto out_free_dentry_tree;
- }
-
- DEBUG("Done reading image metadata");
-
- imd->root_dentry = dentry;
- imd->inode_list = inode_list;
- goto out_free_buf;
-out_free_dentry_tree:
- free_dentry_tree(dentry, NULL);
-out_free_security_data:
- free_security_data(imd->security_data);
- imd->security_data = NULL;
-out_free_buf:
- FREE(buf);
- return ret;
-}
-
-static void recalculate_security_data_length(struct wim_security_data *sd)
-{
- u32 total_length = sizeof(u64) * sd->num_entries + 2 * sizeof(u32);
- for (u32 i = 0; i < sd->num_entries; i++)
- total_length += sd->sizes[i];
- sd->total_length = total_length;
-}
-
-/* Write the metadata resource for the current WIM image. */
-int write_metadata_resource(WIMStruct *w)
-{
- u8 *buf;
- u8 *p;
- int ret;
- u64 subdir_offset;
- struct dentry *root;
- struct lookup_table_entry *lte;
- u64 metadata_original_size;
- struct wim_security_data *sd;
-
- DEBUG("Writing metadata resource for image %d (offset = %"PRIu64")",
- w->current_image, ftello(w->out_fp));
-
- root = wim_root_dentry(w);
- sd = wim_security_data(w);
-
- /* Offset of first child of the root dentry. It's equal to:
- * - The total length of the security data, rounded to the next 8-byte
- * boundary,
- * - plus the total length of the root dentry,
- * - plus 8 bytes for an end-of-directory entry following the root
- * dentry (shouldn't really be needed, but just in case...)
- */
- recalculate_security_data_length(sd);
- subdir_offset = (((u64)sd->total_length + 7) & ~7) +
- dentry_correct_total_length(root) + 8;
-
- /* Calculate the subdirectory offsets for the entire dentry tree. */
- calculate_subdir_offsets(root, &subdir_offset);
-
- /* Total length of the metadata resource (uncompressed) */
- metadata_original_size = subdir_offset;
-
- /* Allocate a buffer to contain the uncompressed metadata resource */
- buf = MALLOC(metadata_original_size);
- if (!buf) {
- ERROR("Failed to allocate %"PRIu64" bytes for "
- "metadata resource", metadata_original_size);
- return WIMLIB_ERR_NOMEM;
- }
-
- /* Write the security data into the resource buffer */
- p = write_security_data(sd, buf);
-
- /* Write the dentry tree into the resource buffer */
- p = write_dentry_tree(root, p);
-
- /* We MUST have exactly filled the buffer; otherwise we calculated its
- * size incorrectly or wrote the data incorrectly. */
- wimlib_assert(p - buf == metadata_original_size);
-
- /* Get the lookup table entry for the metadata resource so we can update
- * it. */
- lte = w->image_metadata[w->current_image - 1].metadata_lte;
-
- /* Write the metadata resource to the output WIM using the proper
- * compression type. The lookup table entry for the metadata resource
- * is updated. */
- ret = write_wim_resource_from_buffer(buf, metadata_original_size,
- w->out_fp,
- wimlib_get_compression_type(w),
- <e->output_resource_entry,
- lte->hash);
- if (ret != 0)
- goto out;
-
- /* It's very likely the SHA1 message digest of the metadata resource
- * changed, so re-insert the lookup table entry into the lookup table.
- *
- * We do not check for other lookup table entries having the same SHA1
- * message digest. It's possible for 2 absolutely identical images to
- * be added, therefore causing 2 identical metadata resources to be in
- * the WIM. However, in this case, it's expected for 2 separate lookup
- * table entries to be created, even though this doesn't make a whole
- * lot of sense since they will share the same SHA1 message digest.
- * */
- lookup_table_unlink(w->lookup_table, lte);
- lookup_table_insert(w->lookup_table, lte);
- lte->out_refcnt = 1;
-
- /* Make sure that the lookup table entry for this metadata resource is
- * marked with the metadata flag. */
- lte->output_resource_entry.flags |= WIM_RESHDR_FLAG_METADATA;
-out:
- /* All the data has been written to the new WIM; no need for the buffer
- * anymore */
- FREE(buf);
- return ret;
-}
git://wimlib.net / wimlib / blobdiff