#include <unistd.h>
/*
- * Reads all or part of a compressed WIM resource.
+ * Compressed resources
*
- * Returns zero on success, nonzero on failure.
+ * A compressed resource in a WIM consists of a number of consecutive LZX or
+ * XPRESS-compressed chunks, each of which decompresses to 32768 bytes of data,
+ * except possibly the last, which always decompresses to any remaining bytes.
+ * In addition, immediately before the chunks, a table (the "chunk table")
+ * provides the offset, in bytes relative to the end of the chunk table, of the
+ * start of each compressed chunk, except for the first chunk which is omitted
+ * as it always has an offset of 0. Therefore, a compressed resource with N
+ * chunks will have a chunk table with N - 1 entries.
+ *
+ * Additional information:
+ *
+ * - Entries in the chunk table are 4 bytes each, except if the uncompressed
+ * size of the resource is greater than 4 GiB, in which case the entries in
+ * the chunk table are 8 bytes each. In either case, the entries are unsigned
+ * little-endian integers.
+ *
+ * - The chunk table is included in the compressed size of the resource provided
+ * in the corresponding entry in the WIM's stream lookup table.
+ *
+ * - The compressed size of a chunk is never greater than the uncompressed size.
+ * From the compressor's point of view, chunks that would have compressed to a
+ * size greater than or equal to their original size are in fact stored
+ * uncompressed. From the decompresser's point of view, chunks with
+ * compressed size equal to their uncompressed size are in fact uncompressed.
+ *
+ * Furthermore, wimlib supports its own "pipable" WIM format, and for this the
+ * structure of compressed resources was modified to allow piped reading and
+ * writing. To make sequential writing possible, the chunk table is placed
+ * after the chunks rather than before the chunks, and to make sequential
+ * reading possible, each chunk is prefixed with a 4-byte header giving its
+ * compressed size as a 32-bit, unsigned, little-endian integer (less than or
+ * equal to 32768). Otherwise the details are the same.
+ */
+
+typedef int (*decompress_func_t)(const void *, unsigned, void *, unsigned);
+
+static decompress_func_t
+get_decompress_func(int ctype)
+{
+ if (ctype == WIMLIB_COMPRESSION_TYPE_LZX)
+ return wimlib_lzx_decompress;
+ else
+ return wimlib_xpress_decompress;
+}
+
+/*
+ * read_compressed_resource()-
+ *
+ * Read data from a compressed resource being read from a seekable WIM file.
+ * The resource may be either pipable or non-pipable.
+ *
+ * @flags may be:
+ *
+ * 0:
+ * Just do a normal read, decompressing the data if necessary.
+ *
+ * WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS:
+ * Read the raw contents of the compressed chunks of the compressed
+ * resource. For pipable resources, this does *not* include the chunk
+ * headers. If a callback function is being used, it will be called once
+ * for each compressed chunk. For non-pipable resources, this mode
+ * excludes the chunk table. For pipable resources, this mode excludes the
+ * stream and chunk headers.
*/
static int
-read_compressed_resource(int in_fd,
- u64 resource_compressed_size,
- u64 resource_uncompressed_size,
- u64 resource_offset,
- int resource_ctype,
- u64 len,
- u64 offset,
- consume_data_callback_t cb,
- void *ctx_or_buf)
+read_compressed_resource(const struct wim_lookup_table_entry *lte,
+ u64 size, consume_data_callback_t cb,
+ void *ctx_or_buf, int flags, u64 offset)
{
int ret;
- /* Trivial case */
- if (len == 0)
- return 0;
+ /* Currently, reading raw compressed chunks is only guaranteed to work
+ * correctly when the full resource is requested. Furthermore, in such
+ * cases the requested size is specified as the compressed size, but
+ * here we change it to an uncompressed size to avoid confusing the rest
+ * of this function. */
+ if (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS) {
+ wimlib_assert(offset == 0);
+ wimlib_assert(size == lte->resource_entry.size);
+ size = wim_resource_size(lte);
+ }
- int (*decompress)(const void *, unsigned, void *, unsigned);
- /* Set the appropriate decompress function. */
- if (resource_ctype == WIMLIB_COMPRESSION_TYPE_LZX)
- decompress = wimlib_lzx_decompress;
- else
- decompress = wimlib_xpress_decompress;
-
- /* The structure of a compressed resource consists of a table of chunk
- * offsets followed by the chunks themselves. Each chunk consists of
- * compressed data, and there is one chunk for each WIM_CHUNK_SIZE =
- * 32768 bytes of the uncompressed file, with the last chunk having any
- * remaining bytes.
- *
- * The chunk offsets are measured relative to the end of the chunk
- * table. The first chunk is omitted from the table in the WIM file
- * because its offset is implicitly given by the fact that it directly
- * follows the chunk table and therefore must have an offset of 0.
- */
+ wimlib_assert(offset + size <= wim_resource_size(lte));
- /* Calculate how many chunks the resource consists of in its entirety.
- * */
- u64 num_chunks = (resource_uncompressed_size + WIM_CHUNK_SIZE - 1) /
- WIM_CHUNK_SIZE;
- /* As mentioned, the first chunk has no entry in the chunk table. */
- u64 num_chunk_entries = num_chunks - 1;
+ /* Handle the trivial case. */
+ if (size == 0)
+ return 0;
+ /* Get the appropriate decompression function. */
+ decompress_func_t decompress =
+ get_decompress_func(wim_resource_compression_type(lte));
- /* The index of the chunk that the read starts at. */
- u64 start_chunk = offset / WIM_CHUNK_SIZE;
- /* The byte offset at which the read starts, within the start chunk. */
- u64 start_chunk_offset = offset % WIM_CHUNK_SIZE;
+ /* Get the file descriptor for the WIM. */
+ struct filedes *in_fd = <e->wim->in_fd;
- /* The index of the chunk that contains the last byte of the read. */
- u64 end_chunk = (offset + len - 1) / WIM_CHUNK_SIZE;
- /* The byte offset of the last byte of the read, within the end chunk */
- u64 end_chunk_offset = (offset + len - 1) % WIM_CHUNK_SIZE;
+ /* Calculate the number of chunks the resource is divided into. */
+ u64 num_chunks = wim_resource_chunks(lte);
- /* Number of chunks that are actually needed to read the requested part
- * of the file. */
- u64 num_needed_chunks = end_chunk - start_chunk + 1;
+ /* Calculate the number of entries in the chunk table; it's one less
+ * than the number of chunks, since the first chunk has no entry. */
+ u64 num_chunk_entries = num_chunks - 1;
- /* If the end chunk is not the last chunk, an extra chunk entry is
- * needed because we need to know the offset of the chunk after the last
- * chunk read to figure out the size of the last read chunk. */
+ /* Calculate the 0-based index of the chunk at which the read starts.
+ */
+ u64 start_chunk = offset / WIM_CHUNK_SIZE;
+
+ /* Calculate the offset, within the start chunk, of the first byte of
+ * the read. */
+ u64 start_offset_in_chunk = offset % WIM_CHUNK_SIZE;
+
+ /* Calculate the index of the chunk that contains the last byte of the
+ * read. */
+ u64 end_chunk = (offset + size - 1) / WIM_CHUNK_SIZE;
+
+ /* Calculate the offset, within the end chunk, of the last byte of the
+ * read. */
+ u64 end_offset_in_chunk = (offset + size - 1) % WIM_CHUNK_SIZE;
+
+ /* Calculate the number of chunk entries are actually needed to read the
+ * requested part of the resource. Include an entry for the first chunk
+ * even though that doesn't exist in the on-disk table, but take into
+ * account that if the last chunk required for the read is not the last
+ * chunk of the resource, an extra chunk entry is needed so that the
+ * compressed size of the last chunk of the read can be determined. */
+ u64 num_alloc_chunk_entries = end_chunk - start_chunk + 1;
if (end_chunk != num_chunks - 1)
- num_needed_chunks++;
+ num_alloc_chunk_entries++;
- /* According to M$'s documentation, if the uncompressed size of
- * the file is greater than 4 GB, the chunk entries are 8-byte
- * integers. Otherwise, they are 4-byte integers. */
- u64 chunk_entry_size = (resource_uncompressed_size >
- (u64)1 << 32) ? 8 : 4;
+ /* Set the size of each chunk table entry based on the resource's
+ * uncompressed size. */
+ u64 chunk_entry_size = (wim_resource_size(lte) > ((u64)1 << 32)) ? 8 : 4;
- /* Size of the full chunk table in the WIM file. */
- u64 chunk_table_size = chunk_entry_size * num_chunk_entries;
+ /* Calculate the size, in bytes, of the full chunk table. */
+ u64 chunk_table_size = num_chunk_entries * chunk_entry_size;
- /* Allocate the chunk table. It will only contain offsets for the
- * chunks that are actually needed for this read. */
+ /* Allocate a buffer to hold a subset of the chunk table. It will only
+ * contain offsets for the chunks that are actually needed for this
+ * read. For speed, allocate the buffer on the stack unless it's too
+ * large. */
u64 *chunk_offsets;
bool chunk_offsets_malloced;
- if (num_needed_chunks < 1024) {
- chunk_offsets = alloca(num_needed_chunks * sizeof(u64));
+ if (num_alloc_chunk_entries < 1024) {
+ chunk_offsets = alloca(num_alloc_chunk_entries * sizeof(u64));
chunk_offsets_malloced = false;
} else {
- chunk_offsets = malloc(num_needed_chunks * sizeof(u64));
+ chunk_offsets = malloc(num_alloc_chunk_entries * sizeof(u64));
if (!chunk_offsets) {
ERROR("Failed to allocate chunk table "
- "with %"PRIu64" entries", num_needed_chunks);
+ "with %"PRIu64" entries", num_alloc_chunk_entries);
return WIMLIB_ERR_NOMEM;
}
chunk_offsets_malloced = true;
}
- /* Set the implicit offset of the first chunk if it is included in the
- * needed chunks.
- *
- * Note: M$'s documentation includes a picture that shows the first
- * chunk starting right after the chunk entry table, labeled as offset
- * 0x10. However, in the actual file format, the offset is measured
- * from the end of the chunk entry table, so the first chunk has an
- * offset of 0. */
+ /* Set the implicit offset of the first chunk if it's included in the
+ * needed chunks. */
if (start_chunk == 0)
chunk_offsets[0] = 0;
-
- /* Read the needed chunk offsets from the table in the WIM file. */
-
- /* Index, in the WIM file, of the first needed entry in the
- * chunk table. */
+ /* Calculate the index of the first needed entry in the chunk table. */
u64 start_table_idx = (start_chunk == 0) ? 0 : start_chunk - 1;
- /* Number of entries we need to actually read from the chunk
- * table (excludes the implicit first chunk). */
+ /* Calculate the number of entries that need to be read from the chunk
+ * table. */
u64 num_needed_chunk_entries = (start_chunk == 0) ?
- num_needed_chunks - 1 : num_needed_chunks;
-
- /* Skip over unneeded chunk table entries. */
- u64 file_offset_of_needed_chunk_entries = resource_offset +
- start_table_idx * chunk_entry_size;
-
- /* Allocate a buffer into which to read the raw chunk entries. */
- void *chunk_tab_buf;
- bool chunk_tab_buf_malloced = false;
-
- /* Number of bytes we need to read from the chunk table. */
- size_t size = num_needed_chunk_entries * chunk_entry_size;
- if ((u64)size != num_needed_chunk_entries * chunk_entry_size) {
+ num_alloc_chunk_entries - 1 : num_alloc_chunk_entries;
+
+ /* Calculate the number of bytes of data that need to be read from the
+ * chunk table. */
+ size_t chunk_table_needed_size =
+ num_needed_chunk_entries * chunk_entry_size;
+ if ((u64)chunk_table_needed_size !=
+ num_needed_chunk_entries * chunk_entry_size)
+ {
ERROR("Compressed read request too large to fit into memory!");
ret = WIMLIB_ERR_NOMEM;
- goto out;
- }
-
- if (size < 4096) {
- chunk_tab_buf = alloca(size);
- } else {
- chunk_tab_buf = malloc(size);
- if (!chunk_tab_buf) {
- ERROR("Failed to allocate chunk table buffer of "
- "size %zu bytes", size);
- ret = WIMLIB_ERR_NOMEM;
- goto out;
- }
- chunk_tab_buf_malloced = true;
+ goto out_free_chunk_offsets;
}
- if (full_pread(in_fd, chunk_tab_buf, size,
- file_offset_of_needed_chunk_entries) != size)
+ /* Calculate the byte offset, in the WIM file, of the first chunk table
+ * entry to read. Take into account that if the WIM file is in the
+ * special "pipable" format, then the chunk table is at the end of the
+ * resource, not the beginning. */
+ u64 file_offset_of_needed_chunk_entries =
+ lte->resource_entry.offset + (start_table_idx *
+ chunk_entry_size);
+ if (lte->is_pipable)
+ file_offset_of_needed_chunk_entries += lte->resource_entry.size -
+ chunk_table_size;
+
+ /* Read the needed chunk table entries into the end of the chunk_offsets
+ * buffer. */
+ void *chunk_tab_data = (u8*)&chunk_offsets[num_alloc_chunk_entries] -
+ chunk_table_needed_size;
+ ret = full_pread(in_fd, chunk_tab_data, chunk_table_needed_size,
+ file_offset_of_needed_chunk_entries);
+ if (ret)
goto read_error;
/* Now fill in chunk_offsets from the entries we have read in
- * chunk_tab_buf. */
-
- u64 *chunk_tab_p = chunk_offsets;
- if (start_chunk == 0)
- chunk_tab_p++;
-
- if (chunk_entry_size == 4) {
- le32 *entries = (le32*)chunk_tab_buf;
- while (num_needed_chunk_entries--)
- *chunk_tab_p++ = le32_to_cpu(*entries++);
- } else {
- le64 *entries = (le64*)chunk_tab_buf;
- while (num_needed_chunk_entries--)
- *chunk_tab_p++ = le64_to_cpu(*entries++);
+ * chunk_tab_data. Careful: chunk_offsets aliases chunk_tab_data, which
+ * breaks C's aliasing rules when we read 32-bit integers and store
+ * 64-bit integers. But since the operations are safe as long as the
+ * compiler doesn't mess with their order, we use the gcc may_alias
+ * extension to tell the compiler that loads from the 32-bit integers
+ * may alias stores to the 64-bit integers. */
+ {
+ typedef le64 __attribute__((may_alias)) aliased_le64_t;
+ typedef le32 __attribute__((may_alias)) aliased_le32_t;
+ u64 *chunk_offsets_p = chunk_offsets;
+ u64 i;
+
+ if (start_chunk == 0)
+ chunk_offsets_p++;
+
+ if (chunk_entry_size == 4) {
+ aliased_le32_t *raw_entries = (aliased_le32_t*)chunk_tab_data;
+ for (i = 0; i < num_needed_chunk_entries; i++)
+ chunk_offsets_p[i] = le32_to_cpu(raw_entries[i]);
+ } else {
+ aliased_le64_t *raw_entries = (aliased_le64_t*)chunk_tab_data;
+ for (i = 0; i < num_needed_chunk_entries; i++)
+ chunk_offsets_p[i] = le64_to_cpu(raw_entries[i]);
+ }
}
- /* Done reading the chunk table now. Now calculate the file offset for
- * the first byte of compressed data we need to read. */
-
- u64 cur_read_offset = resource_offset + chunk_table_size + chunk_offsets[0];
+ /* Calculate file offset of the first chunk that needs to be read. N.B.
+ * if the resource is pipable, the entries in the chunk table do *not*
+ * include the chunk headers. */
+ u64 cur_read_offset = lte->resource_entry.offset + chunk_offsets[0];
+ if (!lte->is_pipable)
+ cur_read_offset += chunk_table_size;
+ else
+ cur_read_offset += start_chunk *
+ sizeof(struct pwm_chunk_hdr);
- /* Pointer to current position in the output buffer for uncompressed
- * data. Alternatively, if using a callback function, we repeatedly
- * fill a temporary buffer to feed data into the callback function. */
+ /* If using a callback function, allocate a temporary buffer that will
+ * be used to pass data to it. If writing directly to a buffer instead,
+ * arrange to write data directly into it. */
u8 *out_p;
if (cb)
out_p = alloca(WIM_CHUNK_SIZE);
else
out_p = ctx_or_buf;
- /* Buffer for compressed data. While most compressed chunks will have a
- * size much less than WIM_CHUNK_SIZE, WIM_CHUNK_SIZE - 1 is the maximum
- * size in the worst-case. This assumption is valid only if chunks that
- * happen to compress to more than the uncompressed size (i.e. a
- * sequence of random bytes) are always stored uncompressed. But this seems
- * to be the case in M$'s WIM files, even though it is undocumented. */
- void *compressed_buf = alloca(WIM_CHUNK_SIZE - 1);
-
- /* Decompress all the chunks. */
+ /* Unless the raw compressed data was requested, allocate a temporary
+ * buffer for reading compressed chunks, each of which can be at most
+ * WIM_CHUNK_SIZE - 1 bytes. This excludes compressed chunks that are a
+ * full WIM_CHUNK_SIZE bytes, which are handled separately. */
+ void *compressed_buf;
+ if (!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS))
+ compressed_buf = alloca(WIM_CHUNK_SIZE - 1);
+
+ /* Read, and possibly decompress, each needed chunk, either writing the
+ * data directly into the @ctx_or_buf buffer or passing it to the @cb
+ * callback function. */
for (u64 i = start_chunk; i <= end_chunk; i++) {
+ /* If the resource is pipable, skip the chunk header. */
+ if (lte->is_pipable)
+ cur_read_offset += sizeof(struct pwm_chunk_hdr);
+
/* Calculate the sizes of the compressed chunk and of the
- * uncompressed chunk. */
+ * uncompressed chunk. */
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
- * of compressed data for the chunk is given by the
- * difference of offsets in the chunk offset table. */
+ /* Not the last chunk. Compressed size is given by
+ * difference of chunk table entries; uncompressed size
+ * is always 32768 bytes. */
compressed_chunk_size = chunk_offsets[i + 1 - start_chunk] -
chunk_offsets[i - start_chunk];
uncompressed_chunk_size = WIM_CHUNK_SIZE;
} else {
- /* The last compressed chunk consists of the remaining
- * bytes in the file resource, and the last uncompressed
- * chunk has size equal to however many bytes are left-
- * that is, the remainder of the uncompressed size when
- * divided by WIM_CHUNK_SIZE.
- *
- * Note that the resource_compressed_size includes the
- * chunk table, so the size of it must be subtracted. */
- compressed_chunk_size = resource_compressed_size -
+ /* Last chunk. Compressed size is the remaining size in
+ * the compressed resource; uncompressed size is the
+ * remaining size in the uncompressed resource. */
+ compressed_chunk_size = lte->resource_entry.size -
chunk_table_size -
chunk_offsets[i - start_chunk];
+ if (lte->is_pipable)
+ compressed_chunk_size -= num_chunks *
+ sizeof(struct pwm_chunk_hdr);
- uncompressed_chunk_size = resource_uncompressed_size %
- WIM_CHUNK_SIZE;
-
- /* If the remainder is 0, the last chunk actually
- * uncompresses to a full WIM_CHUNK_SIZE bytes. */
- if (uncompressed_chunk_size == 0)
+ if (wim_resource_size(lte) % WIM_CHUNK_SIZE == 0)
uncompressed_chunk_size = WIM_CHUNK_SIZE;
+ else
+ uncompressed_chunk_size = wim_resource_size(lte) %
+ WIM_CHUNK_SIZE;
}
- /* Figure out how much of this chunk we actually need to read */
- u64 start_offset;
- if (i == start_chunk)
- start_offset = start_chunk_offset;
- else
- start_offset = 0;
- u64 end_offset;
- if (i == end_chunk)
- end_offset = end_chunk_offset;
- else
- end_offset = WIM_CHUNK_SIZE - 1;
-
- unsigned partial_chunk_size = end_offset + 1 - start_offset;
- bool is_partial_chunk = (partial_chunk_size != uncompressed_chunk_size);
-
- /* This is undocumented, but chunks can be uncompressed. This
- * appears to always be the case when the compressed chunk size
- * is equal to the uncompressed chunk size. */
- if (compressed_chunk_size == uncompressed_chunk_size) {
- /* Uncompressed chunk */
- if (full_pread(in_fd,
- cb ? out_p + start_offset : out_p,
- partial_chunk_size,
- cur_read_offset + start_offset) != partial_chunk_size)
- {
+ /* Calculate how much of this chunk needs to be read. */
+
+ unsigned partial_chunk_size;
+ u64 start_offset = 0;
+ u64 end_offset = WIM_CHUNK_SIZE - 1;
+
+ if (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS) {
+ partial_chunk_size = compressed_chunk_size;
+ } else {
+ if (i == start_chunk)
+ start_offset = start_offset_in_chunk;
+
+ if (i == end_chunk)
+ end_offset = end_offset_in_chunk;
+
+ partial_chunk_size = end_offset + 1 - start_offset;
+ }
+
+ if (compressed_chunk_size == uncompressed_chunk_size ||
+ (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS))
+ {
+ /* Chunk stored uncompressed, or reading raw chunk data. */
+ ret = full_pread(in_fd,
+ cb ? out_p + start_offset : out_p,
+ partial_chunk_size,
+ cur_read_offset + start_offset);
+ if (ret)
goto read_error;
- }
} else {
- /* Compressed chunk */
+ /* Compressed chunk and not doing raw read. */
- /* Read the compressed data into compressed_buf. */
- if (full_pread(in_fd,
- compressed_buf,
- compressed_chunk_size,
- cur_read_offset) != compressed_chunk_size)
- {
+ /* Read the compressed data into compressed_buf. */
+ ret = full_pread(in_fd,
+ compressed_buf,
+ compressed_chunk_size,
+ cur_read_offset);
+ if (ret)
goto read_error;
- }
/* For partial chunks and when writing directly to a
* buffer, we must buffer the uncompressed data because
- * we don't need all of it. */
- if (is_partial_chunk && !cb) {
+ * we don't need all of it. */
+ if (partial_chunk_size != uncompressed_chunk_size &&
+ cb == NULL)
+ {
u8 uncompressed_buf[uncompressed_chunk_size];
- ret = decompress(compressed_buf,
- compressed_chunk_size,
- uncompressed_buf,
- uncompressed_chunk_size);
+ ret = (*decompress)(compressed_buf,
+ compressed_chunk_size,
+ uncompressed_buf,
+ uncompressed_chunk_size);
if (ret) {
+ ERROR("Failed to decompress data.");
ret = WIMLIB_ERR_DECOMPRESSION;
- goto out;
+ errno = EINVAL;
+ goto out_free_chunk_offsets;
}
memcpy(out_p, uncompressed_buf + start_offset,
partial_chunk_size);
} else {
- ret = decompress(compressed_buf,
- compressed_chunk_size,
- out_p,
- uncompressed_chunk_size);
+ ret = (*decompress)(compressed_buf,
+ compressed_chunk_size,
+ out_p,
+ uncompressed_chunk_size);
if (ret) {
+ ERROR("Failed to decompress data.");
ret = WIMLIB_ERR_DECOMPRESSION;
- goto out;
+ errno = EINVAL;
+ goto out_free_chunk_offsets;
}
}
}
if (cb) {
- /* Feed the data to the callback function */
+ /* Feed the data to the callback function. */
ret = cb(out_p + start_offset,
partial_chunk_size, ctx_or_buf);
if (ret)
- goto out;
+ goto out_free_chunk_offsets;
} else {
/* No callback function provided; we are writing
* directly to a buffer. Advance the pointer into this
}
ret = 0;
-out:
+out_free_chunk_offsets:
if (chunk_offsets_malloced)
FREE(chunk_offsets);
- if (chunk_tab_buf_malloced)
- FREE(chunk_tab_buf);
return ret;
read_error:
ERROR_WITH_ERRNO("Error reading compressed file resource");
- ret = WIMLIB_ERR_READ;
- goto out;
+ goto out_free_chunk_offsets;
}
-/* Translates a WIM resource entry from the on-disk format to an in-memory
- * format. */
-void
-get_resource_entry(const struct resource_entry_disk *disk_entry,
- struct resource_entry *entry)
+/* Skip over the chunk table at the end of pipable, compressed resource being
+ * read from a pipe. */
+static int
+skip_chunk_table(const struct wim_lookup_table_entry *lte,
+ struct filedes *in_fd)
{
- /* Note: disk_entry may not be 8 byte aligned--- in that case, the
- * offset and original_size members will be unaligned. (This should be
- * okay since `struct resource_entry_disk' is declared as packed.) */
-
- /* Read the size and flags into a bitfield portably... */
- entry->size = (((u64)disk_entry->size[0] << 0) |
- ((u64)disk_entry->size[1] << 8) |
- ((u64)disk_entry->size[2] << 16) |
- ((u64)disk_entry->size[3] << 24) |
- ((u64)disk_entry->size[4] << 32) |
- ((u64)disk_entry->size[5] << 40) |
- ((u64)disk_entry->size[6] << 48));
- entry->flags = disk_entry->flags;
- entry->offset = le64_to_cpu(disk_entry->offset);
- entry->original_size = le64_to_cpu(disk_entry->original_size);
+ u64 num_chunk_entries = wim_resource_chunks(lte) - 1;
+ u64 chunk_entry_size = (wim_resource_size(lte) > ((u64)1 << 32)) ? 8 : 4;
+ u64 chunk_table_size = num_chunk_entries * chunk_entry_size;
+ int ret;
- /* offset and original_size are truncated to 62 bits to avoid possible
- * overflows, when converting to a signed 64-bit integer (off_t) or when
- * adding size or original_size. This is okay since no one would ever
- * actually have a WIM bigger than 4611686018427387903 bytes... */
- if (entry->offset & 0xc000000000000000ULL) {
- WARNING("Truncating offset in resource entry");
- entry->offset &= 0x3fffffffffffffffULL;
- }
- if (entry->original_size & 0xc000000000000000ULL) {
- WARNING("Truncating original_size in resource entry");
- entry->original_size &= 0x3fffffffffffffffULL;
+ if (num_chunk_entries != 0) {
+ u8 dummy;
+ ret = full_pread(in_fd, &dummy, 1,
+ in_fd->offset + chunk_table_size - 1);
+ if (ret)
+ return ret;
}
+ return 0;
}
-/* Translates a WIM resource entry from an in-memory format into the on-disk
- * format. */
-void
-put_resource_entry(const struct resource_entry *entry,
- struct resource_entry_disk *disk_entry)
+/* Read and decompress data from a compressed, pipable resource being read from
+ * a pipe. */
+static int
+read_pipable_resource(const struct wim_lookup_table_entry *lte,
+ u64 size, consume_data_callback_t cb,
+ void *ctx_or_buf, int flags, u64 offset)
{
- /* Note: disk_entry may not be 8 byte aligned--- in that case, the
- * offset and original_size members will be unaligned. (This should be
- * okay since `struct resource_entry_disk' is declared as packed.) */
- u64 size = entry->size;
+ struct filedes *in_fd;
+ decompress_func_t decompress;
+ int ret;
+ u8 chunk[WIM_CHUNK_SIZE];
+ u8 cchunk[WIM_CHUNK_SIZE - 1];
+
+ /* Get pointers to appropriate decompression function and the input file
+ * descriptor. */
+ decompress = get_decompress_func(wim_resource_compression_type(lte));
+ in_fd = <e->wim->in_fd;
+
+ /* This function currently assumes the entire resource is being read at
+ * once and that the raw compressed data isn't being requested. This is
+ * based on the fact that this function currently only gets called
+ * during the operation of wimlib_extract_image_from_pipe(). */
+ wimlib_assert(!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW));
+ wimlib_assert(offset == 0);
+ wimlib_assert(size == wim_resource_size(lte));
+ wimlib_assert(in_fd->offset == lte->resource_entry.offset);
+
+ for (offset = 0; offset < size; offset += WIM_CHUNK_SIZE) {
+ struct pwm_chunk_hdr chunk_hdr;
+ u32 chunk_size;
+ u32 cchunk_size;
+ u8 *res_chunk;
+ u32 res_chunk_size;
+
+ /* Calculate uncompressed size of next chunk. */
+ chunk_size = min(WIM_CHUNK_SIZE, size - offset);
+
+ /* Read the compressed size of the next chunk from the chunk
+ * header. */
+ ret = full_read(in_fd, &chunk_hdr, sizeof(chunk_hdr));
+ if (ret)
+ goto read_error;
- disk_entry->size[0] = size >> 0;
- disk_entry->size[1] = size >> 8;
- disk_entry->size[2] = size >> 16;
- disk_entry->size[3] = size >> 24;
- disk_entry->size[4] = size >> 32;
- disk_entry->size[5] = size >> 40;
- disk_entry->size[6] = size >> 48;
- disk_entry->flags = entry->flags;
- disk_entry->offset = cpu_to_le64(entry->offset);
- disk_entry->original_size = cpu_to_le64(entry->original_size);
+ cchunk_size = le32_to_cpu(chunk_hdr.compressed_size);
+
+ if (cchunk_size > WIM_CHUNK_SIZE) {
+ errno = EINVAL;
+ ret = WIMLIB_ERR_INVALID_PIPABLE_WIM;
+ goto invalid;
+ }
+
+ /* Read chunk data. */
+ ret = full_read(in_fd, cchunk, cchunk_size);
+ if (ret)
+ goto read_error;
+
+ if (flags & WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY)
+ continue;
+
+ /* Decompress chunk if needed. Uncompressed size same
+ * as compressed size means the chunk is uncompressed.
+ */
+ res_chunk_size = chunk_size;
+ if (cchunk_size == chunk_size) {
+ res_chunk = cchunk;
+ } else {
+ ret = (*decompress)(cchunk, cchunk_size,
+ chunk, chunk_size);
+ if (ret) {
+ errno = EINVAL;
+ ret = WIMLIB_ERR_DECOMPRESSION;
+ goto invalid;
+ }
+ res_chunk = chunk;
+ }
+
+ /* Feed the uncompressed data into the callback function or copy
+ * it into the provided buffer. */
+ if (cb) {
+ ret = cb(res_chunk, res_chunk_size, ctx_or_buf);
+ if (ret)
+ return ret;
+ } else {
+ ctx_or_buf = mempcpy(ctx_or_buf, res_chunk,
+ res_chunk_size);
+ }
+ }
+
+ ret = skip_chunk_table(lte, in_fd);
+ if (ret)
+ goto read_error;
+ return 0;
+
+read_error:
+ ERROR_WITH_ERRNO("Error reading compressed file resource");
+ return ret;
+
+invalid:
+ ERROR("Compressed file resource is invalid");
+ return ret;
}
-static int
+/*
+ * read_partial_wim_resource()-
+ *
+ * Read a range of data from a uncompressed or compressed resource in a WIM
+ * file. Data is written into a buffer or fed into a callback function, as
+ * documented in read_resource_prefix().
+ *
+ * @flags can be:
+ *
+ * 0:
+ * Just do a normal read, decompressing the data if necessary. @size and
+ * @offset are interpreted relative to the uncompressed contents of the
+ * stream.
+ *
+ * WIMLIB_READ_RESOURCE_FLAG_RAW_FULL:
+ * Only valid when the resource is compressed: Read the raw contents of
+ * the compressed resource. If the resource is non-pipable, this includes
+ * the chunk table as well as the compressed chunks. If the resource is
+ * pipable, this includes the compressed chunks--- including the chunk
+ * headers--- and the chunk table. The stream header is still *not*
+ * included.
+ *
+ * In this mode, @offset is relative to the beginning of the raw contents
+ * of the compressed resource--- that is, the chunk table if the resource
+ * is non-pipable, or the header for the first compressed chunk if the
+ * resource is pipable. @size is the number of raw bytes to read, which
+ * must not overrun the end of the resource. For example, if @offset is 0,
+ * then @size can be at most the raw size of the compressed resource
+ * (@lte->resource_entry.size).
+ *
+ * WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS:
+ * Only valid when the resource is compressed and is not being read from a
+ * pipe: Read the raw contents of the compressed chunks of the compressed
+ * resource. For pipable resources, this does *not* include the chunk
+ * headers. If a callback function is being used, it will be called once
+ * for each compressed chunk. The chunk table is excluded. Also, for
+ * pipable resources, the stream and chunk headers are excluded. In this
+ * mode, @size must be exactly the raw size of the compressed resource
+ * (@lte->resource_entry.size) and @offset must be 0.
+ *
+ * WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY:
+ * Only valid when the resource is being read from a pipe: Skip over the
+ * requested data rather than feed it to the callback function or write it
+ * into the buffer. No decompression is done.
+ * WIMLIB_READ_RESOURCE_FLAG_RAW_* may not be combined with this flag.
+ * @offset must be 0 and @size must be the uncompressed size of the
+ * resource.
+ *
+ * Return values:
+ * WIMLIB_ERR_SUCCESS (0)
+ * WIMLIB_ERR_READ (errno set)
+ * WIMLIB_ERR_UNEXPECTED_END_OF_FILE (errno set to 0)
+ * WIMLIB_ERR_NOMEM (errno set to ENOMEM)
+ * WIMLIB_ERR_DECOMPRESSION (errno set to EINVAL)
+ * WIMLIB_ERR_INVALID_PIPABLE_WIM (errno set to EINVAL)
+ *
+ * or other error code returned by the @cb function.
+ */
+int
read_partial_wim_resource(const struct wim_lookup_table_entry *lte,
- u64 size,
- consume_data_callback_t cb,
- void *ctx_or_buf,
- int flags,
- u64 offset)
+ u64 size, consume_data_callback_t cb,
+ void *ctx_or_buf, int flags, u64 offset)
{
- WIMStruct *wim;
- int in_fd;
+ struct filedes *in_fd;
int ret;
+ /* Make sure the resource is actually located in a WIM file and is not
+ * somewhere else. */
wimlib_assert(lte->resource_location == RESOURCE_IN_WIM);
- wim = lte->wim;
- in_fd = wim->in_fd;
-
- if (lte->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED &&
- !(flags & WIMLIB_RESOURCE_FLAG_RAW))
+ /* Retrieve input file descriptor for the WIM file. */
+ in_fd = <e->wim->in_fd;
+
+ /* Don't allow raw reads (either full or chunks) of uncompressed
+ * resources. */
+ wimlib_assert(!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW) ||
+ resource_is_compressed(<e->resource_entry));
+
+ /* Don't allow seek-only reads unless reading from a pipe; also don't
+ * allow combining SEEK_ONLY with either RAW flag. */
+ wimlib_assert(!(flags & WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY) ||
+ (!filedes_is_seekable(in_fd) &&
+ !(flags & WIMLIB_READ_RESOURCE_FLAG_RAW)));
+
+ DEBUG("Reading WIM resource: %"PRIu64" @ +%"PRIu64" "
+ "from %"PRIu64" @ +%"PRIu64" (readflags 0x%08x, resflags 0x%02x%s)",
+ size, offset,
+ lte->resource_entry.original_size, lte->resource_entry.offset,
+ flags, lte->resource_entry.flags,
+ (lte->is_pipable ? ", pipable" : ""));
+
+ if ((flags & WIMLIB_READ_RESOURCE_FLAG_RAW_FULL) ||
+ !resource_is_compressed(<e->resource_entry))
{
- ret = read_compressed_resource(in_fd,
- lte->resource_entry.size,
- lte->resource_entry.original_size,
- lte->resource_entry.offset,
- wimlib_get_compression_type(wim),
- size,
- offset,
- cb,
- ctx_or_buf);
- } else {
+ /* Reading raw resource contents or reading uncompressed
+ * resource. */
+ wimlib_assert(offset + size <= lte->resource_entry.size);
offset += lte->resource_entry.offset;
- if (cb) {
+ if (flags & WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY) {
+ if (lte->resource_entry.size != 0) {
+ u8 dummy;
+ ret = full_pread(in_fd, &dummy, 1,
+ offset + lte->resource_entry.size - 1);
+ if (ret)
+ goto read_error;
+ }
+ } else if (cb) {
/* Send data to callback function */
u8 buf[min(WIM_CHUNK_SIZE, size)];
while (size) {
- size_t bytes_to_read = min(WIM_CHUNK_SIZE, size);
- size_t bytes_read = full_pread(in_fd, buf,
- bytes_to_read, offset);
- if (bytes_read != bytes_to_read)
+ size_t bytes_to_read = min(WIM_CHUNK_SIZE,
+ size);
+ ret = full_pread(in_fd, buf, bytes_to_read,
+ offset);
+ if (ret)
goto read_error;
- ret = cb(buf, bytes_read, ctx_or_buf);
+ ret = cb(buf, bytes_to_read, ctx_or_buf);
if (ret)
goto out;
- size -= bytes_read;
- offset += bytes_read;
+ size -= bytes_to_read;
+ offset += bytes_to_read;
}
} else {
/* Send data directly to a buffer */
- if (full_pread(in_fd, ctx_or_buf, size, offset) != size)
+ ret = full_pread(in_fd, ctx_or_buf, size, offset);
+ if (ret)
goto read_error;
}
ret = 0;
+ } else if (lte->is_pipable && !filedes_is_seekable(in_fd)) {
+ /* Reading compressed, pipable resource from pipe. */
+ ret = read_pipable_resource(lte, size, cb,
+ ctx_or_buf, flags, offset);
+ } else {
+ /* Reading compressed, possibly pipable resource from seekable
+ * file. */
+ ret = read_compressed_resource(lte, size, cb,
+ ctx_or_buf, flags, offset);
}
goto out;
+
read_error:
ERROR_WITH_ERRNO("Error reading data from WIM");
- ret = WIMLIB_ERR_READ;
out:
- if (ret) {
- if (errno == 0)
- errno = EIO;
- }
return ret;
}
{
const tchar *filename = lte->file_on_disk;
int ret;
- int fd;
- size_t bytes_read;
+ struct filedes fd;
+ int raw_fd;
+
+ DEBUG("Reading %"PRIu64" bytes from \"%"TS"\"",
+ size, lte->file_on_disk);
- fd = open(filename, O_RDONLY);
- if (fd < 0) {
+ raw_fd = open(filename, O_RDONLY);
+ if (raw_fd < 0) {
ERROR_WITH_ERRNO("Can't open \"%"TS"\"", filename);
return WIMLIB_ERR_OPEN;
}
+ filedes_init(&fd, raw_fd);
if (cb) {
/* Send data to callback function */
u8 buf[min(WIM_CHUNK_SIZE, size)];
size_t bytes_to_read;
while (size) {
bytes_to_read = min(WIM_CHUNK_SIZE, size);
- bytes_read = full_read(fd, buf, bytes_to_read);
- if (bytes_read != bytes_to_read)
+ ret = full_read(&fd, buf, bytes_to_read);
+ if (ret)
goto read_error;
- ret = cb(buf, bytes_read, ctx_or_buf);
+ ret = cb(buf, bytes_to_read, ctx_or_buf);
if (ret)
goto out_close;
- size -= bytes_read;
+ size -= bytes_to_read;
}
} else {
/* Send data directly to a buffer */
- bytes_read = full_read(fd, ctx_or_buf, size);
- if (bytes_read != size)
+ ret = full_read(&fd, ctx_or_buf, size);
+ if (ret)
goto read_error;
}
ret = 0;
goto out_close;
+
read_error:
ERROR_WITH_ERRNO("Error reading \"%"TS"\"", filename);
- ret = WIMLIB_ERR_READ;
out_close:
- close(fd);
+ filedes_close(&fd);
return ret;
}
#endif /* !__WIN32__ */
int flags);
/*
+ * read_resource_prefix()-
+ *
* Read the first @size bytes from a generic "resource", which may be located in
* the WIM (compressed or uncompressed), in an external file, or directly in an
* in-memory buffer.
* When using a callback function, it is called with chunks up to 32768 bytes in
* size until the resource is exhausted.
*
- * If the resource is located in a WIM file, @flags can be:
- * * WIMLIB_RESOURCE_FLAG_RAW if the raw compressed data is to be supplied
- * instead of the uncompressed data.
- * Otherwise, the @flags are ignored.
+ * If the resource is located in a WIM file, @flags can be set as documented in
+ * read_partial_wim_resource(). Otherwise @flags are ignored.
*/
int
read_resource_prefix(const struct wim_lookup_table_entry *lte,
{
static const read_resource_prefix_handler_t handlers[] = {
[RESOURCE_IN_WIM] = read_wim_resource_prefix,
- #ifndef __WIN32__
+ #ifdef __WIN32__
+ [RESOURCE_IN_FILE_ON_DISK] = read_win32_file_prefix,
+ #else
[RESOURCE_IN_FILE_ON_DISK] = read_file_on_disk_prefix,
#endif
[RESOURCE_IN_ATTACHED_BUFFER] = read_buffer_prefix,
[RESOURCE_IN_NTFS_VOLUME] = read_ntfs_file_prefix,
#endif
#ifdef __WIN32__
- [RESOURCE_WIN32] = read_win32_file_prefix,
[RESOURCE_WIN32_ENCRYPTED] = read_win32_encrypted_file_prefix,
#endif
};
return read_resource_prefix(lte, wim_resource_size(lte), NULL, buf, 0);
}
+int
+read_full_resource_into_alloc_buf(const struct wim_lookup_table_entry *lte,
+ void **buf_ret)
+{
+ int ret;
+ void *buf;
+
+ if ((size_t)lte->resource_entry.original_size !=
+ lte->resource_entry.original_size)
+ {
+ ERROR("Can't read %"PRIu64" byte resource into "
+ "memory", lte->resource_entry.original_size);
+ return WIMLIB_ERR_NOMEM;
+ }
+
+ buf = MALLOC(lte->resource_entry.original_size);
+ if (!buf)
+ return WIMLIB_ERR_NOMEM;
+
+ ret = read_full_resource_into_buf(lte, buf);
+ if (ret) {
+ FREE(buf);
+ return ret;
+ }
+
+ *buf_ret = buf;
+ return 0;
+}
+
+int
+res_entry_to_data(const struct resource_entry *res_entry,
+ WIMStruct *wim, void **buf_ret)
+{
+ int ret;
+ struct wim_lookup_table_entry *lte;
+
+ lte = new_lookup_table_entry();
+ if (!lte)
+ return WIMLIB_ERR_NOMEM;
+
+ copy_resource_entry(<e->resource_entry, res_entry);
+ lte->unhashed = 1;
+ lte->part_number = wim->hdr.part_number;
+ lte_init_wim(lte, wim);
+
+ ret = read_full_resource_into_alloc_buf(lte, buf_ret);
+ free_lookup_table_entry(lte);
+ return ret;
+}
+
struct extract_ctx {
SHA_CTX sha_ctx;
consume_data_callback_t extract_chunk;
u8 hash[SHA1_HASH_SIZE];
sha1_final(hash, &ctx.sha_ctx);
if (!hashes_equal(hash, lte->hash)) {
- #ifdef ENABLE_ERROR_MESSAGES
- ERROR("Invalid SHA1 message digest "
- "on the following WIM resource:");
- print_lookup_table_entry(lte, stderr);
- if (lte->resource_location == RESOURCE_IN_WIM)
- ERROR("The WIM file appears to be corrupt!");
- #endif
+ if (wimlib_print_errors) {
+ ERROR("Invalid SHA1 message digest "
+ "on the following WIM resource:");
+ print_lookup_table_entry(lte, stderr);
+ if (lte->resource_location == RESOURCE_IN_WIM)
+ ERROR("The WIM file appears to be corrupt!");
+ }
ret = WIMLIB_ERR_INVALID_RESOURCE_HASH;
}
}
static int
extract_wim_chunk_to_fd(const void *buf, size_t len, void *_fd_p)
{
- int fd = *(int*)_fd_p;
- ssize_t ret = full_write(fd, buf, len);
- if (ret < len) {
+ struct filedes *fd = _fd_p;
+ int ret = full_write(fd, buf, len);
+ if (ret)
ERROR_WITH_ERRNO("Error writing to file descriptor");
- return WIMLIB_ERR_WRITE;
- } else {
- return 0;
- }
+ return ret;
}
int
extract_wim_resource_to_fd(const struct wim_lookup_table_entry *lte,
- int fd, u64 size)
+ struct filedes *fd, u64 size)
{
- return extract_wim_resource(lte, size, extract_wim_chunk_to_fd, &fd);
+ return extract_wim_resource(lte, size, extract_wim_chunk_to_fd, fd);
}
return ret;
}
-/*
- * Copies the file resource specified by the lookup table entry @lte from the
- * input WIM to the output WIM that has its FILE * given by
- * ((WIMStruct*)wim)->out_fp.
- *
- * The output_resource_entry, out_refcnt, and part_number fields of @lte are
- * updated.
- *
- * (This function is confusing and should be refactored somehow.)
- */
-int
-copy_resource(struct wim_lookup_table_entry *lte, void *wim)
+/* Translates a WIM resource entry from the on-disk format to an in-memory
+ * format. */
+void
+get_resource_entry(const struct resource_entry_disk *disk_entry,
+ struct resource_entry *entry)
{
- WIMStruct *w = wim;
- int ret;
+ /* Note: disk_entry may not be 8 byte aligned--- in that case, the
+ * offset and original_size members will be unaligned. (This should be
+ * okay since `struct resource_entry_disk' is declared as packed.) */
- ret = write_wim_resource(lte, w->out_fd,
- wim_resource_compression_type(lte),
- <e->output_resource_entry, 0);
- if (ret == 0) {
- lte->out_refcnt = lte->refcnt;
- lte->part_number = w->hdr.part_number;
+ /* Read the size and flags into a bitfield portably... */
+ entry->size = (((u64)disk_entry->size[0] << 0) |
+ ((u64)disk_entry->size[1] << 8) |
+ ((u64)disk_entry->size[2] << 16) |
+ ((u64)disk_entry->size[3] << 24) |
+ ((u64)disk_entry->size[4] << 32) |
+ ((u64)disk_entry->size[5] << 40) |
+ ((u64)disk_entry->size[6] << 48));
+ entry->flags = disk_entry->flags;
+ entry->offset = le64_to_cpu(disk_entry->offset);
+ entry->original_size = le64_to_cpu(disk_entry->original_size);
+
+ /* offset and original_size are truncated to 62 bits to avoid possible
+ * overflows, when converting to a signed 64-bit integer (off_t) or when
+ * adding size or original_size. This is okay since no one would ever
+ * actually have a WIM bigger than 4611686018427387903 bytes... */
+ if (entry->offset & 0xc000000000000000ULL) {
+ WARNING("Truncating offset in resource entry");
+ entry->offset &= 0x3fffffffffffffffULL;
}
- return ret;
+ if (entry->original_size & 0xc000000000000000ULL) {
+ WARNING("Truncating original_size in resource entry");
+ entry->original_size &= 0x3fffffffffffffffULL;
+ }
+}
+
+/* Translates a WIM resource entry from an in-memory format into the on-disk
+ * format. */
+void
+put_resource_entry(const struct resource_entry *entry,
+ struct resource_entry_disk *disk_entry)
+{
+ /* Note: disk_entry may not be 8 byte aligned--- in that case, the
+ * offset and original_size members will be unaligned. (This should be
+ * okay since `struct resource_entry_disk' is declared as packed.) */
+ u64 size = entry->size;
+
+ disk_entry->size[0] = size >> 0;
+ disk_entry->size[1] = size >> 8;
+ disk_entry->size[2] = size >> 16;
+ disk_entry->size[3] = size >> 24;
+ disk_entry->size[4] = size >> 32;
+ disk_entry->size[5] = size >> 40;
+ disk_entry->size[6] = size >> 48;
+ disk_entry->flags = entry->flags;
+ disk_entry->offset = cpu_to_le64(entry->offset);
+ disk_entry->original_size = cpu_to_le64(entry->original_size);
}
git://wimlib.net / wimlib / blobdiff