X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fmetadata_resource.c;h=b80ee710bca6f81db4ac6b0c7bece9ef5f0bf344;hp=3e8b7283e17f3267fb5d660df3db0412e41c9150;hb=e3dc3c76cf0896eb98f455f2538999d23f95b61a;hpb=4f8059f2d0a74a9922128b162d9c9343b305999c

diff --git a/src/metadata_resource.c b/src/metadata_resource.c
index 3e8b7283..b80ee710 100644
--- a/src/metadata_resource.c
+++ b/src/metadata_resource.c
@@ -20,161 +20,115 @@
  * 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/lookup_table.h"
+#include "wimlib/metadata.h"
+#include "wimlib/resource.h"
+#include "wimlib/security.h"
+#include "wimlib/write.h"
 
 /*
- * 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
- * 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.
+ * Reads and parses a metadata resource for an image in the WIM file.
  *
- * @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;
-	int ret;
-	struct wim_dentry *dentry;
 	const struct wim_lookup_table_entry *metadata_lte;
-	u64 metadata_len;
+	void *buf;
+	int ret;
+	struct wim_security_data *sd;
+	struct wim_dentry *root;
+	struct wim_inode *inode;
 
 	metadata_lte = imd->metadata_lte;
-	metadata_len = wim_resource_size(metadata_lte);
-
-	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. */
-	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);
+	DEBUG("Reading metadata resource (size=%"PRIu64").", metadata_lte->size);
 
-	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_resource_into_buf(metadata_lte, buf);
+	/* Read the metadata resource into memory.  (It may be compressed.)  */
+	ret = read_full_stream_into_alloc_buf(metadata_lte, &buf);
 	if (ret)
-		goto out_free_buf;
-
-	DEBUG("Finished reading metadata resource into memory.");
+		return ret;
+
+	/* Checksum the metadata resource.  */
+	if (!metadata_lte->dont_check_metadata_hash) {
+		u8 hash[SHA1_HASH_SIZE];
+
+		sha1_buffer(buf, metadata_lte->size, 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;
+		}
+	}
 
-	/* 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.
+	/* Parse the metadata resource.
 	 *
-	 * 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);
+	 * Notes: 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.  */
+
+	ret = read_wim_security_data(buf, metadata_lte->size, &sd);
 	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));
-		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);
+	ret = read_dentry_tree(buf, metadata_lte->size, sd->total_length, &root);
+	if (ret)
 		goto out_free_security_data;
-	}
 
-	inode_add_dentry(dentry, dentry->d_inode);
+	/* We have everything we need from the buffer now.  */
+	FREE(buf);
+	buf = NULL;
 
-	/* Now read the entire directory entry tree into memory. */
-	DEBUG("Reading dentry tree");
-	ret = read_dentry_tree(buf, metadata_len, dentry);
-	if (ret)
-		goto out_free_dentry_tree;
+	/* Calculate and validate inodes.  */
 
-	/* 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);
+	image_for_each_inode(inode, imd) {
+		ret = verify_inode(inode, sd);
 		if (ret)
 			goto out_free_dentry_tree;
 	}
 
-	DEBUG("Done reading image metadata");
-
-	imd->root_dentry = dentry;
+	/* Success; fill in the image_metadata structure.  */
+	imd->root_dentry = root;
+	imd->security_data = sd;
 	INIT_LIST_HEAD(&imd->unhashed_streams);
-	goto out_free_buf;
+	DEBUG("Done parsing metadata resource.");
+	return 0;
+
 out_free_dentry_tree:
-	free_dentry_tree(dentry, NULL);
+	free_dentry_tree(root, NULL);
 out_free_security_data:
-	free_security_data(imd->security_data);
-	imd->security_data = NULL;
+	free_wim_security_data(sd);
 out_free_buf:
 	FREE(buf);
 	return ret;
@@ -186,55 +140,40 @@ 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(&lte, 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 = wim->image_metadata[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
@@ -245,51 +184,65 @@ write_metadata_resource(WIMStruct *w)
 	 */
 	recalculate_security_data_length(sd);
 	subdir_offset = (((u64)sd->total_length + 7) & ~7) +
-			dentry_correct_total_length(root) + 8;
+			dentry_out_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);
+
+	*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;
 
-	/* Get the lookup table entry for the metadata resource so we can update
-	 * it. */
-	lte = wim_get_current_image_metadata(w)->metadata_lte;
+	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),
-					     &lte->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->out_compression_type,
+					     wim->out_chunk_size,
+					     &imd->metadata_lte->out_reshdr,
+					     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;
 }