}
/*
- * Reads some data from a WIM resource.
+ * Reads some data from the resource corresponding to a WIM lookup table entry.
*
- * If %raw is true, compressed data is read literally rather than being
- * decompressed first.
+ * @lte: The WIM lookup table entry for the resource.
+ * @buf: Buffer into which to write the data.
+ * @size: Number of bytes to read.
+ * @offset: Offset at which to start reading the resource.
+ * @raw: If %true, compressed data is read literally rather than being
+ * decompressed first.
*
* Returns zero on success, nonzero on failure.
*/
-static int __read_wim_resource(const struct lookup_table_entry *lte,
- u8 buf[], size_t size, u64 offset, bool raw)
+int read_wim_resource(const struct lookup_table_entry *lte, u8 buf[],
+ size_t size, u64 offset, bool raw)
{
/* We shouldn't be allowing read over-runs in any part of the library.
* */
}
}
-/*
- * Reads some data from the resource corresponding to a WIM lookup table entry.
- *
- * @lte: The WIM lookup table entry for the resource.
- * @buf: Buffer into which to write the data.
- * @size: Number of bytes to read.
- * @offset: Offset at which to start reading the resource.
- *
- * Returns 0 on success; nonzero on failure.
- */
-int read_wim_resource(const struct lookup_table_entry *lte, u8 buf[],
- size_t size, u64 offset)
-{
- return __read_wim_resource(lte, buf, size, offset, false);
-}
-
/*
* Reads all the data from the resource corresponding to a WIM lookup table
* entry.
*/
int read_full_wim_resource(const struct lookup_table_entry *lte, u8 buf[])
{
- return __read_wim_resource(lte, buf, wim_resource_size(lte), 0, false);
+ return read_wim_resource(lte, buf, wim_resource_size(lte), 0, false);
}
+/* Chunk table that's located at the beginning of each compressed resource in
+ * the WIM. (This is not the on-disk format; the on-disk format just has an
+ * array of offsets.) */
struct chunk_table {
off_t file_offset;
u64 num_chunks;
u64 offsets[0];
};
+/*
+ * Allocates and initializes a chunk table, and reserves space for it in the
+ * output file.
+ */
static int
begin_wim_resource_chunk_tab(const struct lookup_table_entry *lte,
FILE *out_fp,
return ret;
}
+/*
+ * Compresses a chunk of a WIM resource.
+ *
+ * @chunk: Uncompressed data of the chunk.
+ * @chunk_size: Size of the uncompressed chunk in bytes.
+ * @compressed_chunk: Pointer to output buffer of size at least
+ * (@chunk_size - 1) bytes.
+ * @compressed_chunk_len_ret: Pointer to an unsigned int into which the size
+ * of the compressed chunk will be
+ * returned.
+ * @ctype: Type of compression to use. Must be WIM_COMPRESSION_TYPE_LZX
+ * or WIM_COMPRESSION_TYPE_XPRESS.
+ *
+ * Returns zero if compressed succeeded, and nonzero if the chunk could not be
+ * compressed to any smaller than @chunk_size. This function cannot fail for
+ * any other reasons.
+ */
static int compress_chunk(const u8 chunk[], unsigned chunk_size,
u8 compressed_chunk[],
unsigned *compressed_chunk_len_ret,
compressed_chunk_len_ret);
}
+/*
+ * Writes a chunk of a WIM resource to an output file.
+ *
+ * @chunk: Uncompressed data of the chunk.
+ * @chunk_size: Size of the chunk (<= WIM_CHUNK_SIZE)
+ * @out_fp: FILE * to write tho chunk to.
+ * @out_ctype: Compression type to use when writing the chunk (ignored if no
+ * chunk table provided)
+ * @chunk_tab: Pointer to chunk table being created. It is updated with the
+ * offset of the chunk we write.
+ *
+ * Returns 0 on success; nonzero on failure.
+ */
static int write_wim_resource_chunk(const u8 chunk[], unsigned chunk_size,
FILE *out_fp, int out_ctype,
struct chunk_table *chunk_tab)
const u8 *out_chunk;
unsigned out_chunk_size;
+ wimlib_assert(chunk_size <= WIM_CHUNK_SIZE);
+
if (!chunk_tab) {
out_chunk = chunk;
out_chunk_size = chunk_size;
return 0;
}
+/*
+ * Finishes a WIM chunk tale and writes it to the output file at the correct
+ * offset.
+ *
+ * The final size of the full compressed resource is returned in the
+ * @compressed_size_p.
+ */
static int
finish_wim_resource_chunk_tab(struct chunk_table *chunk_tab,
FILE *out_fp, u64 *compressed_size_p)
if (ret != 0)
goto out;
}
+
if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK
&& !lte->file_on_disk_fp)
{
+ /* The WIM resource is in an external file; open a FILE * to it
+ * so we don't have to open a temporary one on every read. */
wimlib_assert(lte->file_on_disk);
lte->file_on_disk_fp = fopen(lte->file_on_disk, "rb");
if (!lte->file_on_disk_fp) {
do {
u64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE);
- ret = __read_wim_resource(lte, buf, to_read, offset, raw);
+ ret = read_wim_resource(lte, buf, to_read, offset, raw);
if (ret != 0)
goto out_fclose;
if (!raw)
}
if (!raw) {
+ /* Verify SHA1 message digest of the resource, unless we are
+ * doing a raw write (in which case we may have never even seen
+ * the uncompressed data) */
u8 md[SHA1_HASH_SIZE];
sha1_final(md, &ctx);
if (!hashes_equal(md, lte->hash)) {
"while we were reading it.",
lte->file_on_disk);
}
- ret = WIMLIB_ERR_INTEGRITY;
+ ret = WIMLIB_ERR_INVALID_RESOURCE_HASH;
goto out_fclose;
}
}
if (out_res_entry) {
out_res_entry->size = new_compressed_size;
out_res_entry->original_size = original_size;
- out_res_entry->offset = file_offset;
- if (out_ctype == WIM_COMPRESSION_TYPE_NONE)
- out_res_entry->flags = 0;
- else
- out_res_entry->flags = WIM_RESHDR_FLAG_COMPRESSED;
- if (lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA)
- out_res_entry->flags |= WIM_RESHDR_FLAG_METADATA;
+ out_res_entry->offset = file_offset;
+ out_res_entry->flags = lte->resource_entry.flags
+ & ~WIM_RESHDR_FLAG_COMPRESSED;
+ if (out_ctype != WIM_COMPRESSION_TYPE_NONE)
+ out_res_entry->flags |= WIM_RESHDR_FLAG_COMPRESSED;
}
out_fclose:
if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK
}
/*
- * Extracts the first @size bytes of the resource specified by @lte to the open
- * file @fd. Returns nonzero on error.
+ * Extracts the first @size bytes of the WIM resource specified by @lte to the
+ * open file descriptor @fd.
+ *
+ * Returns 0 on success; nonzero on failure.
*/
int extract_wim_resource_to_fd(const struct lookup_table_entry *lte, int fd,
u64 size)
char buf[min(WIM_CHUNK_SIZE, bytes_remaining)];
u64 offset = 0;
int ret = 0;
+ u8 hash[SHA1_HASH_SIZE];
+
+ SHA_CTX ctx;
+ sha1_init(&ctx);
while (bytes_remaining) {
u64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE);
- ret = read_wim_resource(lte, buf, to_read, offset);
+ ret = read_wim_resource(lte, buf, to_read, offset, false);
if (ret != 0)
break;
+ sha1_update(&ctx, buf, to_read);
if (full_write(fd, buf, to_read) < 0) {
ERROR_WITH_ERRNO("Error extracting WIM resource");
return WIMLIB_ERR_WRITE;
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;
+ }
return 0;
}
+/*
+ * Extracts the WIM resource specified by @lte to the open file descriptor @fd.
+ *
+ * Returns 0 on success; nonzero on failure.
+ */
int extract_full_wim_resource_to_fd(const struct lookup_table_entry *lte, int fd)
{
return extract_wim_resource_to_fd(lte, fd, wim_resource_size(lte));
/*
* Copies the file resource specified by the lookup table entry @lte from the
- * input WIM, pointed to by the fp field of the WIMStruct, to the output WIM,
- * pointed to by the out_fp field of the WIMStruct.
+ * input WIM the output WIM.
*
* The output_resource_entry, out_refcnt, and part_number fields of @lte are
* updated.
* alternate data streams, to the output file.
*
* @dentry: The dentry for the file.
- * @wim_p: A pointer to the WIMStruct. The fields of interest to this
- * function are the input and output file streams and the lookup
- * table.
+ * @wim_p: A pointer to the WIMStruct containing @dentry.
*
* @return zero on success, nonzero on failure.
*/
*
* @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
- * `lookup_table_entry' 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. 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.
*/
git://wimlib.net / wimlib / blobdiff