X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fmetadata_resource.c;h=13aa5b8dec30cfdb960ed42dea5daffa28917d8d;hp=13a6a96231f9305017e19b96f2d1f97dcc5581a8;hb=694f1955dc495b72a3232bf870e9839bdeb9bff9;hpb=9e56d04309e3e6a896319225288f0c86bd36d34e diff --git a/src/metadata_resource.c b/src/metadata_resource.c index 13a6a962..13aa5b8d 100644 --- a/src/metadata_resource.c +++ b/src/metadata_resource.c @@ -20,12 +20,20 @@ * 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 the metadata metadata resource from the WIM file. The metadata + * Reads a metadata resource for an image in 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 @@ -33,36 +41,39 @@ * 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. + * @w: Pointer to the WIMStruct for the WIM file. * - * @return: Zero on success, nonzero on failure. + * @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. */ -int read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) +int +read_metadata_resource(WIMStruct *wim, struct wim_image_metadata *imd) { u8 *buf; - u32 dentry_offset; int ret; - struct wim_dentry *dentry; + struct wim_dentry *root; const struct wim_lookup_table_entry *metadata_lte; u64 metadata_len; - struct hlist_head inode_list; + u8 hash[SHA1_HASH_SIZE]; metadata_lte = imd->metadata_lte; metadata_len = wim_resource_size(metadata_lte); - DEBUG("Reading metadata resource: length = %"PRIu64", " - "offset = %"PRIu64"", metadata_len, + DEBUG("Reading metadata resource: original_size = %"PRIu64", " + "size = %"PRIu64", offset = %"PRIu64"", + metadata_lte->resource_entry.original_size, + metadata_lte->resource_entry.size, 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. */ + * entry. */ if (metadata_len < 8 + WIM_DENTRY_DISK_SIZE) { ERROR("Expected at least %u bytes for the metadata resource", 8 + WIM_DENTRY_DISK_SIZE); @@ -85,10 +96,18 @@ int read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) } /* Read the metadata resource into memory. (It may be compressed.) */ - ret = read_full_wim_resource(metadata_lte, buf, 0); - if (ret != 0) + ret = read_full_resource_into_buf(metadata_lte, buf); + if (ret) goto out_free_buf; + 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_RESOURCE_HASH; + goto out_free_buf; + } + DEBUG("Finished reading metadata resource into memory."); /* The root directory entry starts after security data, aligned on an @@ -99,129 +118,113 @@ int read_metadata_resource(WIMStruct *w, struct wim_image_metadata *imd) * 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. */ + * which takes case of rouding total_length. 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) + ret = read_wim_security_data(buf, metadata_len, &imd->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); + ret = read_dentry(buf, metadata_len, + imd->security_data->total_length, root); - /* This is the root dentry, so set its parent to itself. */ - dentry->parent = dentry; - - if (ret == 0 && dentry->length == 0) { + if (ret == 0 && root->length == 0) { ERROR("Metadata resource cannot begin with end-of-directory entry!"); ret = WIMLIB_ERR_INVALID_DENTRY; } - if (ret != 0) { - FREE(dentry); + if (ret) { + FREE(root); 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); - 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) + 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, &inode_list); - if (ret != 0) + ret = dentry_tree_fix_inodes(root, &imd->inode_list); + if (ret) goto out_free_dentry_tree; - if (!w->all_images_verified) { + if (!wim->all_images_verified) { + /* Note: verify_dentry() expects to access imd->security_data, + * so it needs to be set before here. */ 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) + for_lookup_table_entry(wim->lookup_table, lte_zero_real_refcnt, NULL); + ret = for_dentry_in_tree(root, verify_dentry, wim); + if (ret) goto out_free_dentry_tree; } DEBUG("Done reading image metadata"); - imd->root_dentry = dentry; - imd->inode_list = inode_list; - if (imd->inode_list.first) - imd->inode_list.first->pprev = &imd->inode_list.first; + imd->root_dentry = root; + INIT_LIST_HEAD(&imd->unhashed_streams); 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); + free_wim_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) +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; + 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 u8 *buf, u64 buf_size, - FILE *out_fp, int out_ctype, - struct resource_entry *out_res_entry, - u8 hash[SHA1_HASH_SIZE]) +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_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; + 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) +int +write_metadata_resource(WIMStruct *w) { u8 *buf; u8 *p; @@ -231,12 +234,26 @@ int write_metadata_resource(WIMStruct *w) struct wim_lookup_table_entry *lte; u64 metadata_original_size; 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("Writing metadata resource for image %d (offset = %"PRIu64")", - w->current_image, ftello(w->out_fp)); + w->current_image, filedes_offset(w->out_fd)); + + imd = w->image_metadata[w->current_image - 1]; + + root = imd->root_dentry; + sd = imd->security_data; - root = wim_root_dentry(w); - sd = wim_security_data(w); + if (!root) { + /* Empty image; create a dummy root. */ + ret = new_filler_directory(T(""), &root); + if (ret) + return ret; + imd->root_dentry = root; + } /* 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 @@ -264,7 +281,7 @@ int write_metadata_resource(WIMStruct *w) } /* Write the security data into the resource buffer */ - p = write_security_data(sd, buf); + p = write_wim_security_data(sd, buf); /* Write the dentry tree into the resource buffer */ p = write_dentry_tree(root, p); @@ -275,37 +292,21 @@ int write_metadata_resource(WIMStruct *w) /* Get the lookup table entry for the metadata resource so we can update * it. */ - lte = w->image_metadata[w->current_image - 1].metadata_lte; + lte = wim_get_current_image_metadata(w)->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, + w->out_fd, wimlib_get_compression_type(w), <e->output_resource_entry, lte->hash); - if (ret != 0) - goto out; + /* 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. */ - /* 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);