From c6e063fcb2b1ffa76df62ab902a38bf5f604d2e2 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 16 Dec 2012 13:01:25 -0600 Subject: [PATCH] metadata_resource.c --- Makefile.am | 1 + src/metadata_resource.c | 321 ++++++++++++++++++++++++++++++++++++++++ src/resource.c | 296 ------------------------------------ 3 files changed, 322 insertions(+), 296 deletions(-) create mode 100644 src/metadata_resource.c diff --git a/Makefile.am b/Makefile.am index eae0a6f7..d4a3af6a 100644 --- a/Makefile.am +++ b/Makefile.am @@ -34,6 +34,7 @@ libwim_la_SOURCES = \ src/lzx-compress.c \ src/lzx-decompress.c \ src/lzx.h \ + src/metadata_resource.c \ src/mount_image.c \ src/resource.c \ src/rbtree.c \ diff --git a/src/metadata_resource.c b/src/metadata_resource.c new file mode 100644 index 00000000..4f8be141 --- /dev/null +++ b/src/metadata_resource.c @@ -0,0 +1,321 @@ +/* + * metadata_resource.c + */ + +/* + * Copyright (C) 2012 Eric Biggers + * + * This file is part of wimlib, a library for working with WIM files. + * + * wimlib is free software; you can redistribute it and/or modify it under the + * terms of the GNU General Public License as published by the Free Software + * Foundation; either version 3 of the License, or (at your option) any later + * version. + * + * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY + * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR + * A PARTICULAR PURPOSE. See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along with + * wimlib; if not, see http://www.gnu.org/licenses/. + */ + +#include "wimlib_internal.h" +#include "dentry.h" +#include "lookup_table.h" + +/* + * 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; +} + +/* Like write_wim_resource(), but the resource is specified by a buffer of + * uncompressed data rather a lookup table entry; also writes the SHA1 hash of + * the buffer to @hash. */ +static int write_wim_resource_from_buffer(const u8 *buf, u64 buf_size, + FILE *out_fp, int out_ctype, + struct resource_entry *out_res_entry, + u8 hash[SHA1_HASH_SIZE]) +{ + /* Set up a temporary lookup table entry to provide to + * write_wim_resource(). */ + struct lookup_table_entry lte; + int ret; + lte.resource_entry.flags = 0; + lte.resource_entry.original_size = buf_size; + lte.resource_entry.size = buf_size; + lte.resource_entry.offset = 0; + lte.resource_location = RESOURCE_IN_ATTACHED_BUFFER; + lte.attached_buffer = (u8*)buf; + + zero_out_hash(lte.hash); + ret = write_wim_resource(<e, out_fp, out_ctype, out_res_entry, 0); + if (ret != 0) + return ret; + copy_hash(hash, lte.hash); + return 0; +} + +/* 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; +} diff --git a/src/resource.c b/src/resource.c index f8f48448..66360130 100644 --- a/src/resource.c +++ b/src/resource.c @@ -609,33 +609,6 @@ int read_full_wim_resource(const struct lookup_table_entry *lte, u8 buf[], return read_wim_resource(lte, buf, wim_resource_size(lte), 0, flags); } -/* Like write_wim_resource(), but the resource is specified by a buffer of - * uncompressed data rather a lookup table entry; also writes the SHA1 hash of - * the buffer to @hash. */ -static int write_wim_resource_from_buffer(const u8 *buf, u64 buf_size, - FILE *out_fp, int out_ctype, - struct resource_entry *out_res_entry, - u8 hash[SHA1_HASH_SIZE]) -{ - /* Set up a temporary lookup table entry to provide to - * write_wim_resource(). */ - struct lookup_table_entry lte; - int ret; - lte.resource_entry.flags = 0; - lte.resource_entry.original_size = buf_size; - lte.resource_entry.size = buf_size; - lte.resource_entry.offset = 0; - lte.resource_location = RESOURCE_IN_ATTACHED_BUFFER; - lte.attached_buffer = (u8*)buf; - - zero_out_hash(lte.hash); - ret = write_wim_resource(<e, out_fp, out_ctype, out_res_entry, 0); - if (ret != 0) - return ret; - copy_hash(hash, lte.hash); - return 0; -} - /* * Extracts the first @size bytes of the WIM resource specified by @lte to the * open file descriptor @fd. @@ -714,272 +687,3 @@ int copy_resource(struct lookup_table_entry *lte, void *wim) lte->part_number = w->hdr.part_number; return 0; } - -/* - * 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; -} -- 2.43.0