/*
* resource.c
*
- * Read uncompressed and compressed metadata and file resources.
+ * Read uncompressed and compressed metadata and file resources from a WIM file.
*/
/*
* wimlib; if not, see http://www.gnu.org/licenses/.
*/
-#include "config.h"
-
-#include <stdlib.h>
-#include <stdarg.h>
-
-#include "dentry.h"
-
#include "wimlib_internal.h"
+#include "dentry.h"
#include "lookup_table.h"
-#include "io.h"
+#include "buffer_io.h"
#include "lzx.h"
#include "xpress.h"
#include "sha1.h"
-#include <unistd.h>
+
#include <errno.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <unistd.h>
#ifdef WITH_NTFS_3G
#include <time.h>
#include <ntfs-3g/dir.h>
#endif
-
/*
* Reads all or part of a compressed resource into an in-memory buffer.
*
if (len == 0)
return 0;
- int (*decompress)(const void *, uint, void *, uint);
+ int (*decompress)(const void *, unsigned, void *, unsigned);
/* Set the appropriate decompress function. */
- if (resource_ctype == WIM_COMPRESSION_TYPE_LZX)
+ if (resource_ctype == WIMLIB_COMPRESSION_TYPE_LZX)
decompress = lzx_decompress;
else
decompress = xpress_decompress;
/* Calculate the sizes of the compressed chunk and of the
* uncompressed chunk. */
- uint compressed_chunk_size, uncompressed_chunk_size;
+ unsigned compressed_chunk_size;
+ unsigned uncompressed_chunk_size;
if (i != num_chunks - 1) {
/* All the chunks except the last one in the resource
* expand to WIM_CHUNK_SIZE uncompressed, and the amount
return 0;
}
-
-
-
/* Reads the contents of a struct resource_entry, as represented in the on-disk
* format, from the memory pointed to by @p, and fills in the fields of @entry.
* A pointer to the byte after the memory read at @p is returned. */
*
* Returns zero on success, nonzero on failure.
*/
-int read_wim_resource(const struct lookup_table_entry *lte, u8 buf[],
+int read_wim_resource(const struct wim_lookup_table_entry *lte, u8 buf[],
size_t size, u64 offset, int flags)
{
int ctype;
ctype = wim_resource_compression_type(lte);
- wimlib_assert(ctype != WIM_COMPRESSION_TYPE_NONE ||
+ wimlib_assert(ctype != WIMLIB_COMPRESSION_TYPE_NONE ||
(lte->resource_entry.original_size ==
lte->resource_entry.size));
if ((flags & WIMLIB_RESOURCE_FLAG_RAW)
- || ctype == WIM_COMPRESSION_TYPE_NONE)
+ || ctype == WIMLIB_COMPRESSION_TYPE_NONE)
ret = read_uncompressed_resource(fp,
lte->resource_entry.offset + offset,
size, buf);
*
* Returns 0 on success; nonzero on failure.
*/
-int read_full_wim_resource(const struct lookup_table_entry *lte, u8 buf[],
+int read_full_wim_resource(const struct wim_lookup_table_entry *lte, u8 buf[],
int flags)
{
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.
+/* Extracts the first @size bytes of a WIM resource to somewhere. In the
+ * process, the SHA1 message digest of the resource is checked if the full
+ * resource is being extracted.
*
- * Returns 0 on success; nonzero on failure.
- */
-int extract_wim_resource_to_fd(const struct lookup_table_entry *lte, int fd,
- u64 size)
+ * @extract_chunk is a function that is called to extract each chunk of the
+ * resource. */
+int extract_wim_resource(const struct wim_lookup_table_entry *lte,
+ u64 size,
+ extract_chunk_func_t extract_chunk,
+ void *extract_chunk_arg)
{
u64 bytes_remaining = size;
u8 buf[min(WIM_CHUNK_SIZE, bytes_remaining)];
u64 offset = 0;
int ret = 0;
u8 hash[SHA1_HASH_SIZE];
-
+ bool check_hash = (size == wim_resource_size(lte));
SHA_CTX ctx;
- sha1_init(&ctx);
+
+ if (check_hash)
+ sha1_init(&ctx);
while (bytes_remaining) {
- u64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE);
+ u64 to_read = min(bytes_remaining, sizeof(buf));
ret = read_wim_resource(lte, buf, to_read, offset, 0);
if (ret != 0)
- break;
- sha1_update(&ctx, buf, to_read);
- if (full_write(fd, buf, to_read) < to_read) {
+ return ret;
+ if (check_hash)
+ sha1_update(&ctx, buf, to_read);
+ ret = extract_chunk(buf, to_read, offset, extract_chunk_arg);
+ if (ret != 0) {
ERROR_WITH_ERRNO("Error extracting WIM resource");
- return WIMLIB_ERR_WRITE;
+ return ret;
}
bytes_remaining -= to_read;
offset += to_read;
}
- sha1_final(hash, &ctx);
- if (!hashes_equal(hash, lte->hash)) {
- ERROR("Invalid checksum on a WIM resource "
- "(detected when extracting to external file)");
- ERROR("The following WIM resource is invalid:");
- print_lookup_table_entry(lte);
- return WIMLIB_ERR_INVALID_RESOURCE_HASH;
+ if (check_hash) {
+ sha1_final(hash, &ctx);
+ if (!hashes_equal(hash, lte->hash)) {
+ #ifdef ENABLE_ERROR_MESSAGES
+ ERROR("Invalid checksum on the following WIM resource:");
+ print_lookup_table_entry(lte, stderr);
+ #endif
+ return WIMLIB_ERR_INVALID_RESOURCE_HASH;
+ }
}
return 0;
}
-/*
- * Extracts the WIM resource specified by @lte to the open file descriptor @fd.
+/* Write @n bytes from @buf to the file descriptor @fd, retrying on internupt
+ * and on short writes.
*
- * Returns 0 on success; nonzero on failure.
- */
-int extract_full_wim_resource_to_fd(const struct lookup_table_entry *lte, int fd)
+ * Returns short count and set errno on failure. */
+static ssize_t full_write(int fd, const void *buf, size_t n)
+{
+ const char *p = buf;
+ ssize_t ret;
+ ssize_t total = 0;
+
+ while (total != n) {
+ ret = write(fd, p, n);
+ if (ret < 0) {
+ if (errno == EINTR)
+ continue;
+ else
+ break;
+ }
+ total += ret;
+ p += ret;
+ }
+ return total;
+}
+
+int extract_wim_chunk_to_fd(const u8 *buf, size_t len, u64 offset, void *arg)
{
- return extract_wim_resource_to_fd(lte, fd, wim_resource_size(lte));
+ int fd = *(int*)arg;
+ ssize_t ret = full_write(fd, buf, len);
+ if (ret < len) {
+ ERROR_WITH_ERRNO("Error writing to file descriptor");
+ return WIMLIB_ERR_WRITE;
+ } else {
+ return 0;
+ }
}
/*
* The output_resource_entry, out_refcnt, and part_number fields of @lte are
* updated.
*
- * Metadata resources are not copied (they are handled elsewhere for joining and
- * splitting).
+ * (This function is confusing and should be refactored somehow.)
*/
-int copy_resource(struct lookup_table_entry *lte, void *wim)
+int copy_resource(struct wim_lookup_table_entry *lte, void *wim)
{
WIMStruct *w = wim;
int ret;
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;
- u64 metadata_offset;
- struct hlist_head inode_list;
-
- metadata_lte = imd->metadata_lte;
- metadata_len = wim_resource_size(metadata_lte);
- metadata_offset = metadata_lte->resource_entry.offset;
-
- DEBUG("Reading metadata resource: length = %"PRIu64", "
- "offset = %"PRIu64"", metadata_len, metadata_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);
-
-
- if (dentry->length == 0) {
- ERROR("Metadata resource cannot begin with end-of-directory entry!");
- ret = WIMLIB_ERR_INVALID_DENTRY;
- }
-
- if (ret != 0)
- goto out_free_dentry_tree;
-
- /* This is the root dentry, so set its parent to itself. */
- dentry->parent = dentry;
-
- 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;
-
- 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;
-}
-
-/* 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;
- const struct wim_security_data *sd;
-
- DEBUG("Writing metadata resource for image %d", w->current_image);
-
- 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...)
- */
- 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 = wim_metadata_lookup_table_entry(w);
-
- /* 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