X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fmetadata_resource.c;h=e632198940f332928b2e543b78e55e7fd8aa6d77;hp=2f7dfeb6e729ce0ae3dd4c0f7a59ca05f9f96e49;hb=b072e7cbca1ccb874e22aa94e3efae37ce211939;hpb=ac6edfd02c612da68a1b9a1b32ae64c95a87fbb1 diff --git a/src/metadata_resource.c b/src/metadata_resource.c index 2f7dfeb6..e6321989 100644 --- a/src/metadata_resource.c +++ b/src/metadata_resource.c @@ -20,9 +20,17 @@ * wimlib; if not, see http://www.gnu.org/licenses/. */ -#include "wimlib_internal.h" -#include "dentry.h" -#include "lookup_table.h" +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "wimlib/dentry.h" +#include "wimlib/error.h" +#include "wimlib/file_io.h" +#include "wimlib/lookup_table.h" +#include "wimlib/metadata.h" +#include "wimlib/resource.h" +#include "wimlib/security.h" /* * Reads a metadata resource for an image in the WIM file. The metadata @@ -33,25 +41,34 @@ * 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. * - * @w: Pointer to the WIMStruct for the WIM file. + * @wim: + * Pointer to the WIMStruct for the WIM file. * - * @imd: Pointer to the image metadata structure for the image whose - * metadata resource we are reading. 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. + * @imd: + * Pointer to the image metadata structure for the image whose metadata + * resource we are reading. 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. * - * Returns: Zero on success, nonzero on failure. + * Return values: + * WIMLIB_ERR_SUCCESS (0) + * WIMLIB_ERR_INVALID_METADATA_RESOURCE + * WIMLIB_ERR_NOMEM + * WIMLIB_ERR_READ + * WIMLIB_ERR_UNEXPECTED_END_OF_FILE + * WIMLIB_ERR_DECOMPRESSION */ int -read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) +read_metadata_resource(WIMStruct *wim, struct wim_image_metadata *imd) { - u8 *buf; - u32 dentry_offset; + void *buf; int ret; - struct wim_dentry *dentry; + struct wim_dentry *root; const struct wim_lookup_table_entry *metadata_lte; u64 metadata_len; + u8 hash[SHA1_HASH_SIZE]; + struct wim_security_data *security_data; + struct wim_inode *inode; metadata_lte = imd->metadata_lte; metadata_len = wim_resource_size(metadata_lte); @@ -65,116 +82,115 @@ read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) /* 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. */ + * entry. */ 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; + return WIMLIB_ERR_INVALID_METADATA_RESOURCE; } /* Read the metadata resource into memory. (It may be compressed.) */ - ret = read_full_resource_into_buf(metadata_lte, buf); + ret = read_full_resource_into_alloc_buf(metadata_lte, &buf); if (ret) - goto out_free_buf; + return ret; + + if (!metadata_lte->dont_check_metadata_hash) { + sha1_buffer(buf, metadata_len, hash); + if (!hashes_equal(metadata_lte->hash, hash)) { + ERROR("Metadata resource is corrupted " + "(invalid SHA-1 message digest)!"); + ret = WIMLIB_ERR_INVALID_METADATA_RESOURCE; + 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); + ret = read_wim_security_data(buf, metadata_len, &security_data); if (ret) 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 wim_dentry)); - if (!dentry) { - ERROR("Failed to allocate %zu bytes for root dentry", - sizeof(struct wim_dentry)); + root = MALLOC(sizeof(struct wim_dentry)); + if (!root) { ret = WIMLIB_ERR_NOMEM; goto out_free_security_data; } - ret = read_dentry(buf, metadata_len, dentry_offset, dentry); + /* The root directory entry starts after security data, aligned on an + * 8-byte boundary within the metadata resource. Since + * security_data->total_length was already rounded up to an 8-byte + * boundary, its value can be used as the offset of the root directory + * entry. */ + ret = read_dentry(buf, metadata_len, + security_data->total_length, root); + + if (ret == 0 && root->length == 0) { + WARNING("Metadata resource begins with end-of-directory entry " + "(treating as empty image)"); + FREE(root); + root = NULL; + goto out_success; + } - /* This is the root dentry, so set its parent to itself. */ - dentry->parent = dentry; + if (ret) { + FREE(root); + goto out_free_security_data; + } - if (ret == 0 && dentry->length == 0) { - ERROR("Metadata resource cannot begin with end-of-directory entry!"); - ret = WIMLIB_ERR_INVALID_DENTRY; + if (dentry_has_long_name(root) || dentry_has_short_name(root)) { + WARNING("The root directory has a nonempty name (removing it)"); + FREE(root->file_name); + FREE(root->short_name); + root->file_name = NULL; + root->short_name = NULL; + root->file_name_nbytes = 0; + root->short_name_nbytes = 0; } - if (ret != 0) { - FREE(dentry); + if (!dentry_is_directory(root)) { + ERROR("Root of the WIM image must be a directory!"); + FREE(root); + ret = WIMLIB_ERR_INVALID_METADATA_RESOURCE; goto out_free_security_data; } - inode_add_dentry(dentry, dentry->d_inode); + /* This is the root dentry, so set its parent to itself. */ + root->parent = root; + + inode_add_dentry(root, root->d_inode); /* Now read the entire directory entry tree into memory. */ DEBUG("Reading dentry tree"); - ret = read_dentry_tree(buf, metadata_len, dentry); + ret = read_dentry_tree(buf, metadata_len, root); if (ret) goto out_free_dentry_tree; /* Build hash table that maps hard link group IDs to dentry sets */ - ret = dentry_tree_fix_inodes(dentry, &imd->inode_list); + ret = dentry_tree_fix_inodes(root, &imd->inode_list); if (ret) 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); + + DEBUG("Running miscellaneous verifications on the dentry tree"); + image_for_each_inode(inode, imd) { + ret = verify_inode(inode, security_data); if (ret) goto out_free_dentry_tree; } - DEBUG("Done reading image metadata"); - - imd->root_dentry = dentry; +out_success: + imd->root_dentry = root; + imd->security_data = security_data; INIT_LIST_HEAD(&imd->unhashed_streams); + ret = 0; goto out_free_buf; out_free_dentry_tree: - free_dentry_tree(dentry, NULL); + free_dentry_tree(root, wim->lookup_table); out_free_security_data: - free_security_data(imd->security_data); - imd->security_data = NULL; + free_wim_security_data(security_data); out_free_buf: FREE(buf); return ret; @@ -186,60 +202,35 @@ 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; + sd->total_length = (total_length + 7) & ~7; } -/* 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 void *buf, size_t buf_size, - int out_fd, 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 wim_lookup_table_entry lte; - int ret; - lte.resource_location = RESOURCE_IN_ATTACHED_BUFFER; - lte.attached_buffer = (void*)buf; - lte.resource_entry.original_size = buf_size; - lte.resource_entry.flags = 0; - lte.unhashed = 1; - ret = write_wim_resource(<e, out_fd, out_ctype, out_res_entry, 0); - if (ret == 0) - copy_hash(hash, lte.hash); - return ret; -} - -/* Write the metadata resource for the current WIM image. */ -int -write_metadata_resource(WIMStruct *w) +prepare_metadata_resource(WIMStruct *wim, int image, + u8 **buf_ret, size_t *len_ret) { u8 *buf; u8 *p; int ret; u64 subdir_offset; struct wim_dentry *root; - struct wim_lookup_table_entry *lte; - u64 metadata_original_size; + u64 len; struct wim_security_data *sd; struct wim_image_metadata *imd; - wimlib_assert(w->out_fd != -1); - wimlib_assert(w->current_image != WIMLIB_NO_IMAGE); + DEBUG("Preparing metadata resource for image %d", image); - DEBUG("Writing metadata resource for image %d (offset = %"PRIu64")", - w->current_image, filedes_offset(w->out_fd)); + ret = select_wim_image(wim, image); + if (ret) + return ret; - imd = w->image_metadata[w->current_image - 1]; + imd = wim->image_metadata[image - 1]; root = imd->root_dentry; sd = imd->security_data; if (!root) { - /* Empty image; create a dummy root. */ + /* Empty image; create a dummy root. */ ret = new_filler_directory(T(""), &root); if (ret) return ret; @@ -257,49 +248,62 @@ write_metadata_resource(WIMStruct *w) subdir_offset = (((u64)sd->total_length + 7) & ~7) + dentry_correct_total_length(root) + 8; - /* Calculate the subdirectory offsets for the entire dentry tree. */ + /* 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; + /* Total length of the metadata resource (uncompressed). */ + len = subdir_offset; - /* Allocate a buffer to contain the uncompressed metadata resource */ - buf = MALLOC(metadata_original_size); + /* Allocate a buffer to contain the uncompressed metadata resource. */ + buf = MALLOC(len); if (!buf) { ERROR("Failed to allocate %"PRIu64" bytes for " - "metadata resource", metadata_original_size); + "metadata resource", len); return WIMLIB_ERR_NOMEM; } - /* Write the security data into the resource buffer */ - p = write_security_data(sd, buf); + /* Write the security data into the resource buffer. */ + p = write_wim_security_data(sd, buf); - /* Write the dentry tree into the resource buffer */ + /* 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); + * size incorrectly or wrote the data incorrectly. */ + wimlib_assert(p - buf == len); - /* Get the lookup table entry for the metadata resource so we can update - * it. */ - lte = wim_get_current_image_metadata(w)->metadata_lte; + *buf_ret = buf; + *len_ret = len; + return 0; +} + +int +write_metadata_resource(WIMStruct *wim, int image, int write_resource_flags) +{ + int ret; + u8 *buf; + size_t len; + struct wim_image_metadata *imd; + + ret = prepare_metadata_resource(wim, image, &buf, &len); + if (ret) + return ret; + + imd = wim->image_metadata[image - 1]; /* 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_fd, - wimlib_get_compression_type(w), - <e->output_resource_entry, - lte->hash); - /* Note that although the SHA1 message digest of the metadata resource - * is very likely to have changed, the corresponding lookup table entry - * is not actually located in the hash table, so it need not be - * re-inserted in the hash table. */ - - /* All the data has been written to the new WIM; no need for the buffer - * anymore */ + * compression type, in the process updating the lookup table entry for + * the metadata resource. */ + ret = write_wim_resource_from_buffer(buf, len, WIM_RESHDR_FLAG_METADATA, + &wim->out_fd, + wim->compression_type, + &imd->metadata_lte->output_resource_entry, + imd->metadata_lte->hash, + write_resource_flags); + + /* Original checksum was overridden; set a flag so it isn't used. */ + imd->metadata_lte->dont_check_metadata_hash = 1; + FREE(buf); return ret; }