4 * Read uncompressed and compressed metadata and file resources.
8 * Copyright (C) 2012 Eric Biggers
10 * This file is part of wimlib, a library for working with WIM files.
12 * wimlib is free software; you can redistribute it and/or modify it under the
13 * terms of the GNU General Public License as published by the Free Software
14 * Foundation; either version 3 of the License, or (at your option) any later
17 * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
18 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
19 * A PARTICULAR PURPOSE. See the GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License along with
22 * wimlib; if not, see http://www.gnu.org/licenses/.
33 #include <ntfs-3g/attrib.h>
34 #include <ntfs-3g/inode.h>
35 #include <ntfs-3g/dir.h>
38 #include "wimlib_internal.h"
39 #include "lookup_table.h"
52 * Reads all or part of a compressed resource into an in-memory buffer.
54 * @fp: The FILE* for the WIM file.
55 * @resource_compressed_size: The compressed size of the resource.
56 * @resource_uncompressed_size: The uncompressed size of the resource.
57 * @resource_offset: The offset of the start of the resource from
58 * the start of the stream @fp.
59 * @resource_ctype: The compression type of the resource.
60 * @len: The number of bytes of uncompressed data to read from
62 * @offset: The offset of the bytes to read within the uncompressed
64 * @contents_len: An array into which the uncompressed data is written.
65 * It must be at least @len bytes long.
67 * Returns zero on success, nonzero on failure.
69 static int read_compressed_resource(FILE *fp, u64 resource_compressed_size,
70 u64 resource_uncompressed_size,
71 u64 resource_offset, int resource_ctype,
72 u64 len, u64 offset, u8 contents_ret[])
75 DEBUG2("comp size = %"PRIu64", uncomp size = %"PRIu64", "
76 "res offset = %"PRIu64"",
77 resource_compressed_size,
78 resource_uncompressed_size,
80 DEBUG2("resource_ctype = %s, len = %"PRIu64", offset = %"PRIu64"",
81 wimlib_get_compression_type_string(resource_ctype), len, offset);
86 int (*decompress)(const void *, uint, void *, uint);
87 /* Set the appropriate decompress function. */
88 if (resource_ctype == WIM_COMPRESSION_TYPE_LZX)
89 decompress = lzx_decompress;
91 decompress = xpress_decompress;
93 /* The structure of a compressed resource consists of a table of chunk
94 * offsets followed by the chunks themselves. Each chunk consists of
95 * compressed data, and there is one chunk for each WIM_CHUNK_SIZE =
96 * 32768 bytes of the uncompressed file, with the last chunk having any
99 * The chunk offsets are measured relative to the end of the chunk
100 * table. The first chunk is omitted from the table in the WIM file
101 * because its offset is implicitly given by the fact that it directly
102 * follows the chunk table and therefore must have an offset of 0.
105 /* Calculate how many chunks the resource conists of in its entirety. */
106 u64 num_chunks = (resource_uncompressed_size + WIM_CHUNK_SIZE - 1) /
108 /* As mentioned, the first chunk has no entry in the chunk table. */
109 u64 num_chunk_entries = num_chunks - 1;
112 /* The index of the chunk that the read starts at. */
113 u64 start_chunk = offset / WIM_CHUNK_SIZE;
114 /* The byte offset at which the read starts, within the start chunk. */
115 u64 start_chunk_offset = offset % WIM_CHUNK_SIZE;
117 /* The index of the chunk that contains the last byte of the read. */
118 u64 end_chunk = (offset + len - 1) / WIM_CHUNK_SIZE;
119 /* The byte offset of the last byte of the read, within the end chunk */
120 u64 end_chunk_offset = (offset + len - 1) % WIM_CHUNK_SIZE;
122 /* Number of chunks that are actually needed to read the requested part
124 u64 num_needed_chunks = end_chunk - start_chunk + 1;
126 /* If the end chunk is not the last chunk, an extra chunk entry is
127 * needed because we need to know the offset of the chunk after the last
128 * chunk read to figure out the size of the last read chunk. */
129 if (end_chunk != num_chunks - 1)
132 /* Declare the chunk table. It will only contain offsets for the chunks
133 * that are actually needed for this read. */
134 u64 chunk_offsets[num_needed_chunks];
136 /* Set the implicit offset of the first chunk if it is included in the
139 * Note: M$'s documentation includes a picture that shows the first
140 * chunk starting right after the chunk entry table, labeled as offset
141 * 0x10. However, in the actual file format, the offset is measured
142 * from the end of the chunk entry table, so the first chunk has an
144 if (start_chunk == 0)
145 chunk_offsets[0] = 0;
147 /* According to M$'s documentation, if the uncompressed size of
148 * the file is greater than 4 GB, the chunk entries are 8-byte
149 * integers. Otherwise, they are 4-byte integers. */
150 u64 chunk_entry_size = (resource_uncompressed_size >= (u64)1 << 32) ?
153 /* Size of the full chunk table in the WIM file. */
154 u64 chunk_table_size = chunk_entry_size * num_chunk_entries;
156 /* Read the needed chunk offsets from the table in the WIM file. */
158 /* Index, in the WIM file, of the first needed entry in the
160 u64 start_table_idx = (start_chunk == 0) ? 0 : start_chunk - 1;
162 /* Number of entries we need to actually read from the chunk
163 * table (excludes the implicit first chunk). */
164 u64 num_needed_chunk_entries = (start_chunk == 0) ?
165 num_needed_chunks - 1 : num_needed_chunks;
167 /* Skip over unneeded chunk table entries. */
168 u64 file_offset_of_needed_chunk_entries = resource_offset +
169 start_table_idx * chunk_entry_size;
170 if (fseeko(fp, file_offset_of_needed_chunk_entries, SEEK_SET) != 0) {
171 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
172 "chunk table of compressed resource",
173 file_offset_of_needed_chunk_entries);
174 return WIMLIB_ERR_READ;
177 /* Number of bytes we need to read from the chunk table. */
178 size_t size = num_needed_chunk_entries * chunk_entry_size;
180 u8 chunk_tab_buf[size];
182 if (fread(chunk_tab_buf, 1, size, fp) != size)
185 /* Now fill in chunk_offsets from the entries we have read in
188 u64 *chunk_tab_p = chunk_offsets;
189 if (start_chunk == 0)
192 if (chunk_entry_size == 4) {
193 u32 *entries = (u32*)chunk_tab_buf;
194 while (num_needed_chunk_entries--)
195 *chunk_tab_p++ = le32_to_cpu(*entries++);
197 u64 *entries = (u64*)chunk_tab_buf;
198 while (num_needed_chunk_entries--)
199 *chunk_tab_p++ = le64_to_cpu(*entries++);
202 /* Done with the chunk table now. We must now seek to the first chunk
203 * that is needed for the read. */
205 u64 file_offset_of_first_needed_chunk = resource_offset +
206 chunk_table_size + chunk_offsets[0];
207 if (fseeko(fp, file_offset_of_first_needed_chunk, SEEK_SET) != 0) {
208 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read "
209 "first chunk of compressed resource",
210 file_offset_of_first_needed_chunk);
211 return WIMLIB_ERR_READ;
214 /* Pointer to current position in the output buffer for uncompressed
216 u8 *out_p = (u8*)contents_ret;
218 /* Buffer for compressed data. While most compressed chunks will have a
219 * size much less than WIM_CHUNK_SIZE, WIM_CHUNK_SIZE - 1 is the maximum
220 * size in the worst-case. This assumption is valid only if chunks that
221 * happen to compress to more than the uncompressed size (i.e. a
222 * sequence of random bytes) are always stored uncompressed. But this seems
223 * to be the case in M$'s WIM files, even though it is undocumented. */
224 u8 compressed_buf[WIM_CHUNK_SIZE - 1];
227 /* Decompress all the chunks. */
228 for (u64 i = start_chunk; i <= end_chunk; i++) {
230 DEBUG2("Chunk %"PRIu64" (start %"PRIu64", end %"PRIu64").",
231 i, start_chunk, end_chunk);
233 /* Calculate the sizes of the compressed chunk and of the
234 * uncompressed chunk. */
235 uint compressed_chunk_size, uncompressed_chunk_size;
236 if (i != num_chunks - 1) {
237 /* All the chunks except the last one in the resource
238 * expand to WIM_CHUNK_SIZE uncompressed, and the amount
239 * of compressed data for the chunk is given by the
240 * difference of offsets in the chunk offset table. */
241 compressed_chunk_size = chunk_offsets[i + 1 - start_chunk] -
242 chunk_offsets[i - start_chunk];
243 uncompressed_chunk_size = WIM_CHUNK_SIZE;
245 /* The last compressed chunk consists of the remaining
246 * bytes in the file resource, and the last uncompressed
247 * chunk has size equal to however many bytes are left-
248 * that is, the remainder of the uncompressed size when
249 * divided by WIM_CHUNK_SIZE.
251 * Note that the resource_compressed_size includes the
252 * chunk table, so the size of it must be subtracted. */
253 compressed_chunk_size = resource_compressed_size -
255 chunk_offsets[i - start_chunk];
257 uncompressed_chunk_size = resource_uncompressed_size %
260 /* If the remainder is 0, the last chunk actually
261 * uncompresses to a full WIM_CHUNK_SIZE bytes. */
262 if (uncompressed_chunk_size == 0)
263 uncompressed_chunk_size = WIM_CHUNK_SIZE;
266 DEBUG2("compressed_chunk_size = %u, "
267 "uncompressed_chunk_size = %u",
268 compressed_chunk_size, uncompressed_chunk_size);
271 /* Figure out how much of this chunk we actually need to read */
273 if (i == start_chunk)
274 start_offset = start_chunk_offset;
279 end_offset = end_chunk_offset;
281 end_offset = WIM_CHUNK_SIZE - 1;
283 u64 partial_chunk_size = end_offset + 1 - start_offset;
284 bool is_partial_chunk = (partial_chunk_size !=
285 uncompressed_chunk_size);
287 DEBUG2("start_offset = %u, end_offset = %u", start_offset,
289 DEBUG2("partial_chunk_size = %u", partial_chunk_size);
291 /* This is undocumented, but chunks can be uncompressed. This
292 * appears to always be the case when the compressed chunk size
293 * is equal to the uncompressed chunk size. */
294 if (compressed_chunk_size == uncompressed_chunk_size) {
295 /* Probably an uncompressed chunk */
297 if (start_offset != 0) {
298 if (fseeko(fp, start_offset, SEEK_CUR) != 0) {
299 ERROR_WITH_ERRNO("Uncompressed partial "
300 "chunk fseek() error");
301 return WIMLIB_ERR_READ;
304 if (fread(out_p, 1, partial_chunk_size, fp) !=
308 /* Compressed chunk */
311 /* Read the compressed data into compressed_buf. */
312 if (fread(compressed_buf, 1, compressed_chunk_size,
313 fp) != compressed_chunk_size)
316 /* For partial chunks we must buffer the uncompressed
317 * data because we don't need all of it. */
318 if (is_partial_chunk) {
319 u8 uncompressed_buf[uncompressed_chunk_size];
321 ret = decompress(compressed_buf,
322 compressed_chunk_size,
324 uncompressed_chunk_size);
326 return WIMLIB_ERR_DECOMPRESSION;
327 memcpy(out_p, uncompressed_buf + start_offset,
330 ret = decompress(compressed_buf,
331 compressed_chunk_size,
333 uncompressed_chunk_size);
335 return WIMLIB_ERR_DECOMPRESSION;
339 /* Advance the pointer into the uncompressed output data by the
340 * number of uncompressed bytes that were written. */
341 out_p += partial_chunk_size;
348 ERROR("Unexpected EOF in compressed file resource");
350 ERROR_WITH_ERRNO("Error reading compressed file resource");
351 return WIMLIB_ERR_READ;
355 * Reads uncompressed data from an open file stream.
357 int read_uncompressed_resource(FILE *fp, u64 offset, u64 len,
360 if (fseeko(fp, offset, SEEK_SET) != 0) {
361 ERROR("Failed to seek to byte %"PRIu64" of input file "
362 "to read uncompressed resource (len = %"PRIu64")",
364 return WIMLIB_ERR_READ;
366 if (fread(contents_ret, 1, len, fp) != len) {
368 ERROR("Unexpected EOF in uncompressed file resource");
370 ERROR("Failed to read %"PRIu64" bytes from "
371 "uncompressed resource at offset %"PRIu64,
374 return WIMLIB_ERR_READ;
382 /* Reads the contents of a struct resource_entry, as represented in the on-disk
383 * format, from the memory pointed to by @p, and fills in the fields of @entry.
384 * A pointer to the byte after the memory read at @p is returned. */
385 const u8 *get_resource_entry(const u8 *p, struct resource_entry *entry)
390 p = get_u56(p, &size);
391 p = get_u8(p, &flags);
393 entry->flags = flags;
395 /* offset and original_size are truncated to 62 bits to avoid possible
396 * overflows, when converting to a signed 64-bit integer (off_t) or when
397 * adding size or original_size. This is okay since no one would ever
398 * actually have a WIM bigger than 4611686018427387903 bytes... */
399 p = get_u64(p, &entry->offset);
400 if (entry->offset & 0xc000000000000000ULL) {
401 WARNING("Truncating offset in resource entry");
402 entry->offset &= 0x3fffffffffffffffULL;
404 p = get_u64(p, &entry->original_size);
405 if (entry->original_size & 0xc000000000000000ULL) {
406 WARNING("Truncating original_size in resource entry");
407 entry->original_size &= 0x3fffffffffffffffULL;
412 /* Copies the struct resource_entry @entry to the memory pointed to by @p in the
413 * on-disk format. A pointer to the byte after the memory written at @p is
415 u8 *put_resource_entry(u8 *p, const struct resource_entry *entry)
417 p = put_u56(p, entry->size);
418 p = put_u8(p, entry->flags);
419 p = put_u64(p, entry->offset);
420 p = put_u64(p, entry->original_size);
425 * Reads some data from the resource corresponding to a WIM lookup table entry.
427 * @lte: The WIM lookup table entry for the resource.
428 * @buf: Buffer into which to write the data.
429 * @size: Number of bytes to read.
430 * @offset: Offset at which to start reading the resource.
431 * @raw: If %true, compressed data is read literally rather than being
432 * decompressed first.
434 * Returns zero on success, nonzero on failure.
436 int read_wim_resource(const struct lookup_table_entry *lte, u8 buf[],
437 size_t size, u64 offset, bool raw)
443 /* We shouldn't be allowing read over-runs in any part of the library.
446 wimlib_assert(offset + size <= lte->resource_entry.size);
448 wimlib_assert(offset + size <= lte->resource_entry.original_size);
450 switch (lte->resource_location) {
451 case RESOURCE_IN_WIM:
452 /* The resource is in a WIM file, and its WIMStruct is given by
453 * the lte->wim member. The resource may be either compressed
454 * or uncompressed. */
455 wimlib_assert(lte->wim != NULL);
456 wimlib_assert(lte->wim->fp != NULL);
457 ctype = wim_resource_compression_type(lte);
459 wimlib_assert(ctype != WIM_COMPRESSION_TYPE_NONE ||
460 (lte->resource_entry.original_size ==
461 lte->resource_entry.size));
463 if (raw || ctype == WIM_COMPRESSION_TYPE_NONE)
464 ret = read_uncompressed_resource(lte->wim->fp,
465 lte->resource_entry.offset + offset,
468 ret = read_compressed_resource(lte->wim->fp,
469 lte->resource_entry.size,
470 lte->resource_entry.original_size,
471 lte->resource_entry.offset,
472 ctype, size, offset, buf);
474 case RESOURCE_IN_STAGING_FILE:
475 case RESOURCE_IN_FILE_ON_DISK:
476 /* The resource is in some file on the external filesystem and
477 * needs to be read uncompressed */
478 wimlib_assert(lte->file_on_disk);
479 wimlib_assert(<e->file_on_disk == <e->staging_file_name);
480 /* Use existing file pointer if available; otherwise open one
482 if (lte->file_on_disk_fp) {
483 fp = lte->file_on_disk_fp;
485 fp = fopen(lte->file_on_disk, "rb");
487 ERROR_WITH_ERRNO("Failed to open the file "
488 "`%s'", lte->file_on_disk);
489 ret = WIMLIB_ERR_OPEN;
493 ret = read_uncompressed_resource(fp, offset, size, buf);
494 if (fp != lte->file_on_disk_fp)
497 case RESOURCE_IN_ATTACHED_BUFFER:
498 /* The resource is directly attached uncompressed in an
499 * in-memory buffer. */
500 wimlib_assert(lte->attached_buffer != NULL);
501 memcpy(buf, lte->attached_buffer + offset, size);
504 case RESOURCE_IN_NTFS_VOLUME:
505 wimlib_assert(lte->ntfs_loc != NULL);
506 wimlib_assert(lte->attr != NULL);
508 if (lte->ntfs_loc->is_reparse_point)
510 if (ntfs_attr_pread(lte->attr, offset, size, buf) != size) {
511 ERROR_WITH_ERRNO("Error reading NTFS attribute "
513 lte->ntfs_loc->path_utf8);
514 ret = WIMLIB_ERR_NTFS_3G;
528 * Reads all the data from the resource corresponding to a WIM lookup table
531 * @lte: The WIM lookup table entry for the resource.
532 * @buf: Buffer into which to write the data. It must be at least
533 * wim_resource_size(lte) bytes long.
535 * Returns 0 on success; nonzero on failure.
537 int read_full_wim_resource(const struct lookup_table_entry *lte, u8 buf[])
539 return read_wim_resource(lte, buf, wim_resource_size(lte), 0, false);
542 /* Chunk table that's located at the beginning of each compressed resource in
543 * the WIM. (This is not the on-disk format; the on-disk format just has an
544 * array of offsets.) */
548 u64 original_resource_size;
549 u64 bytes_per_chunk_entry;
557 * Allocates and initializes a chunk table, and reserves space for it in the
561 begin_wim_resource_chunk_tab(const struct lookup_table_entry *lte,
564 struct chunk_table **chunk_tab_ret)
566 u64 size = wim_resource_size(lte);
567 u64 num_chunks = (size + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE;
568 size_t alloc_size = sizeof(struct chunk_table) + num_chunks * sizeof(u64);
569 struct chunk_table *chunk_tab = CALLOC(1, alloc_size);
573 ERROR("Failed to allocate chunk table for %"PRIu64" byte "
575 ret = WIMLIB_ERR_NOMEM;
578 chunk_tab->file_offset = file_offset;
579 chunk_tab->num_chunks = num_chunks;
580 chunk_tab->original_resource_size = size;
581 chunk_tab->bytes_per_chunk_entry = (size >= (1ULL << 32)) ? 8 : 4;
582 chunk_tab->table_disk_size = chunk_tab->bytes_per_chunk_entry *
584 chunk_tab->cur_offset = 0;
585 chunk_tab->cur_offset_p = chunk_tab->offsets;
587 if (fwrite(chunk_tab, 1, chunk_tab->table_disk_size, out_fp) !=
588 chunk_tab->table_disk_size) {
589 ERROR_WITH_ERRNO("Failed to write chunk table in compressed "
591 ret = WIMLIB_ERR_WRITE;
597 *chunk_tab_ret = chunk_tab;
602 * Compresses a chunk of a WIM resource.
604 * @chunk: Uncompressed data of the chunk.
605 * @chunk_size: Size of the uncompressed chunk in bytes.
606 * @compressed_chunk: Pointer to output buffer of size at least
607 * (@chunk_size - 1) bytes.
608 * @compressed_chunk_len_ret: Pointer to an unsigned int into which the size
609 * of the compressed chunk will be
611 * @ctype: Type of compression to use. Must be WIM_COMPRESSION_TYPE_LZX
612 * or WIM_COMPRESSION_TYPE_XPRESS.
614 * Returns zero if compressed succeeded, and nonzero if the chunk could not be
615 * compressed to any smaller than @chunk_size. This function cannot fail for
618 static int compress_chunk(const u8 chunk[], unsigned chunk_size,
619 u8 compressed_chunk[],
620 unsigned *compressed_chunk_len_ret,
623 int (*compress)(const void *, unsigned, void *, unsigned *);
625 case WIM_COMPRESSION_TYPE_LZX:
626 compress = lzx_compress;
628 case WIM_COMPRESSION_TYPE_XPRESS:
629 compress = xpress_compress;
635 return (*compress)(chunk, chunk_size, compressed_chunk,
636 compressed_chunk_len_ret);
640 * Writes a chunk of a WIM resource to an output file.
642 * @chunk: Uncompressed data of the chunk.
643 * @chunk_size: Size of the chunk (<= WIM_CHUNK_SIZE)
644 * @out_fp: FILE * to write tho chunk to.
645 * @out_ctype: Compression type to use when writing the chunk (ignored if no
646 * chunk table provided)
647 * @chunk_tab: Pointer to chunk table being created. It is updated with the
648 * offset of the chunk we write.
650 * Returns 0 on success; nonzero on failure.
652 static int write_wim_resource_chunk(const u8 chunk[], unsigned chunk_size,
653 FILE *out_fp, int out_ctype,
654 struct chunk_table *chunk_tab)
657 unsigned out_chunk_size;
659 wimlib_assert(chunk_size <= WIM_CHUNK_SIZE);
663 out_chunk_size = chunk_size;
665 u8 *compressed_chunk = alloca(chunk_size);
668 ret = compress_chunk(chunk, chunk_size, compressed_chunk,
669 &out_chunk_size, out_ctype);
671 out_chunk = compressed_chunk;
674 out_chunk_size = chunk_size;
676 *chunk_tab->cur_offset_p++ = chunk_tab->cur_offset;
677 chunk_tab->cur_offset += out_chunk_size;
680 if (fwrite(out_chunk, 1, out_chunk_size, out_fp) != out_chunk_size) {
681 ERROR_WITH_ERRNO("Failed to write WIM resource chunk");
682 return WIMLIB_ERR_WRITE;
688 * Finishes a WIM chunk tale and writes it to the output file at the correct
691 * The final size of the full compressed resource is returned in the
692 * @compressed_size_p.
695 finish_wim_resource_chunk_tab(struct chunk_table *chunk_tab,
696 FILE *out_fp, u64 *compressed_size_p)
698 size_t bytes_written;
699 if (fseeko(out_fp, chunk_tab->file_offset, SEEK_SET) != 0) {
700 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of output "
701 "WIM file", chunk_tab->file_offset);
702 return WIMLIB_ERR_WRITE;
705 if (chunk_tab->bytes_per_chunk_entry == 8) {
706 array_cpu_to_le64(chunk_tab->offsets, chunk_tab->num_chunks);
708 for (u64 i = 0; i < chunk_tab->num_chunks; i++)
709 ((u32*)chunk_tab->offsets)[i] =
710 cpu_to_le32(chunk_tab->offsets[i]);
712 bytes_written = fwrite((u8*)chunk_tab->offsets +
713 chunk_tab->bytes_per_chunk_entry,
714 1, chunk_tab->table_disk_size, out_fp);
715 if (bytes_written != chunk_tab->table_disk_size) {
716 ERROR_WITH_ERRNO("Failed to write chunk table in compressed "
718 return WIMLIB_ERR_WRITE;
720 if (fseeko(out_fp, 0, SEEK_END) != 0) {
721 ERROR_WITH_ERRNO("Failed to seek to end of output WIM file");
722 return WIMLIB_ERR_WRITE;
724 *compressed_size_p = chunk_tab->cur_offset + chunk_tab->table_disk_size;
729 * Writes a WIM resource to a FILE * opened for writing. The resource may be
730 * written uncompressed or compressed depending on the @out_ctype parameter.
732 * If by chance the resource compresses to more than the original size (this may
733 * happen with random data or files than are pre-compressed), the resource is
734 * instead written uncompressed (and this is reflected in the @out_res_entry by
735 * removing the WIM_RESHDR_FLAG_COMPRESSED flag).
737 * @lte: The lookup table entry for the WIM resource.
738 * @out_fp: The FILE * to write the resource to.
739 * @out_ctype: The compression type of the resource to write. Note: if this is
740 * the same as the compression type of the WIM resource we
741 * need to read, we simply copy the data (i.e. we do not
742 * uncompress it, then compress it again).
743 * @out_res_entry: If non-NULL, a resource entry that is filled in with the
744 * offset, original size, compressed size, and compression flag
745 * of the output resource.
747 * Returns 0 on success; nonzero on failure.
749 static int write_wim_resource(struct lookup_table_entry *lte,
750 FILE *out_fp, int out_ctype,
751 struct resource_entry *out_res_entry)
755 u64 old_compressed_size;
756 u64 new_compressed_size;
759 struct chunk_table *chunk_tab = NULL;
763 ntfs_inode *ni = NULL;
768 /* Original size of the resource */
769 original_size = wim_resource_size(lte);
771 /* Compressed size of the resource (as it exists now) */
772 old_compressed_size = wim_resource_compressed_size(lte);
774 /* Current offset in output file */
775 file_offset = ftello(out_fp);
776 if (file_offset == -1) {
777 ERROR_WITH_ERRNO("Failed to get offset in output "
779 return WIMLIB_ERR_WRITE;
782 /* Are the compression types the same? If so, do a raw copy (copy
783 * without decompressing and recompressing the data). */
784 raw = (wim_resource_compression_type(lte) == out_ctype
785 && out_ctype != WIM_COMPRESSION_TYPE_NONE);
787 bytes_remaining = old_compressed_size;
789 bytes_remaining = original_size;
791 /* Empty resource; nothing needs to be done, so just return success. */
792 if (bytes_remaining == 0)
795 /* Buffer for reading chunks for the resource */
796 u8 buf[min(WIM_CHUNK_SIZE, bytes_remaining)];
798 /* If we are writing a compressed resource and not doing a raw copy, we
799 * need to initialize the chunk table */
800 if (out_ctype != WIM_COMPRESSION_TYPE_NONE && !raw) {
801 ret = begin_wim_resource_chunk_tab(lte, out_fp, file_offset,
807 /* If the WIM resource is in an external file, open a FILE * to it so we
808 * don't have to open a temporary one in read_wim_resource() for each
810 if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK
811 && !lte->file_on_disk_fp)
813 wimlib_assert(lte->file_on_disk);
814 lte->file_on_disk_fp = fopen(lte->file_on_disk, "rb");
815 if (!lte->file_on_disk_fp) {
816 ERROR_WITH_ERRNO("Failed to open the file `%s' for "
817 "reading", lte->file_on_disk);
818 ret = WIMLIB_ERR_OPEN;
823 else if (lte->resource_location == RESOURCE_IN_NTFS_VOLUME
826 struct ntfs_location *loc = lte->ntfs_loc;
828 ni = ntfs_pathname_to_inode(*loc->ntfs_vol_p, NULL, loc->path_utf8);
830 ERROR_WITH_ERRNO("Failed to open inode `%s' in NTFS "
831 "volume", loc->path_utf8);
832 ret = WIMLIB_ERR_NTFS_3G;
835 lte->attr = ntfs_attr_open(ni,
836 loc->is_reparse_point ? AT_REPARSE_POINT : AT_DATA,
837 (ntfschar*)loc->stream_name_utf16,
838 loc->stream_name_utf16_num_chars);
840 ERROR_WITH_ERRNO("Failed to open attribute of `%s' in "
841 "NTFS volume", loc->path_utf8);
842 ret = WIMLIB_ERR_NTFS_3G;
848 /* If we aren't doing a raw copy, we will compute the SHA1 message
849 * digest of the resource as we read it, and verify it's the same as the
850 * hash given in the lookup table entry once we've finished reading the
856 /* While there are still bytes remaining in the WIM resource, read a
857 * chunk of the resource, update SHA1, then write that chunk using the
858 * desired compression type. */
861 u64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE);
862 ret = read_wim_resource(lte, buf, to_read, offset, raw);
866 sha1_update(&ctx, buf, to_read);
867 ret = write_wim_resource_chunk(buf, to_read, out_fp,
868 out_ctype, chunk_tab);
871 bytes_remaining -= to_read;
873 } while (bytes_remaining);
875 /* Raw copy: The new compressed size is the same as the old compressed
878 * Using WIM_COMPRESSION_TYPE_NONE: The new compressed size is the
881 * Using a different compression type: Call
882 * finish_wim_resource_chunk_tab() and it will provide the new
886 new_compressed_size = old_compressed_size;
888 if (out_ctype == WIM_COMPRESSION_TYPE_NONE)
889 new_compressed_size = original_size;
891 ret = finish_wim_resource_chunk_tab(chunk_tab, out_fp,
892 &new_compressed_size);
898 /* Verify SHA1 message digest of the resource, unless we are doing a raw
899 * write (in which case we never even saw the uncompressed data). Or,
900 * if the hash we had before is all 0's, just re-set it to be the new
903 u8 md[SHA1_HASH_SIZE];
904 sha1_final(md, &ctx);
905 if (is_zero_hash(lte->hash)) {
906 copy_hash(lte->hash, md);
907 } else if (!hashes_equal(md, lte->hash)) {
908 ERROR("WIM resource has incorrect hash!");
909 if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK) {
910 ERROR("We were reading it from `%s'; maybe it changed "
911 "while we were reading it.",
914 ret = WIMLIB_ERR_INVALID_RESOURCE_HASH;
919 if (!raw && new_compressed_size >= original_size &&
920 out_ctype != WIM_COMPRESSION_TYPE_NONE)
922 /* Oops! We compressed the resource to larger than the original
923 * size. Write the resource uncompressed instead. */
924 if (fseeko(out_fp, file_offset, SEEK_SET) != 0) {
925 ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" "
926 "of output WIM file", file_offset);
927 ret = WIMLIB_ERR_WRITE;
930 ret = write_wim_resource(lte, out_fp, WIM_COMPRESSION_TYPE_NONE,
934 if (fflush(out_fp) != 0) {
935 ERROR_WITH_ERRNO("Failed to flush output WIM file");
936 ret = WIMLIB_ERR_WRITE;
939 if (ftruncate(fileno(out_fp), file_offset + out_res_entry->size) != 0) {
940 ERROR_WITH_ERRNO("Failed to truncate output WIM file");
941 ret = WIMLIB_ERR_WRITE;
946 out_res_entry->size = new_compressed_size;
947 out_res_entry->original_size = original_size;
948 out_res_entry->offset = file_offset;
949 out_res_entry->flags = lte->resource_entry.flags
950 & ~WIM_RESHDR_FLAG_COMPRESSED;
951 if (out_ctype != WIM_COMPRESSION_TYPE_NONE)
952 out_res_entry->flags |= WIM_RESHDR_FLAG_COMPRESSED;
957 if (lte->resource_location == RESOURCE_IN_FILE_ON_DISK
958 && lte->file_on_disk_fp) {
959 fclose(lte->file_on_disk_fp);
960 lte->file_on_disk_fp = NULL;
963 else if (lte->resource_location == RESOURCE_IN_NTFS_VOLUME) {
965 ntfs_attr_close(lte->attr);
969 ntfs_inode_close(ni);
977 /* Like write_wim_resource(), but the resource is specified by a buffer of
978 * uncompressed data rather a lookup table entry; also writes the SHA1 hash of
979 * the buffer to @hash. */
980 static int write_wim_resource_from_buffer(const u8 *buf, u64 buf_size,
981 FILE *out_fp, int out_ctype,
982 struct resource_entry *out_res_entry,
983 u8 hash[SHA1_HASH_SIZE])
985 /* Set up a temporary lookup table entry to provide to
986 * write_wim_resource(). */
987 struct lookup_table_entry lte;
989 lte.resource_entry.flags = 0;
990 lte.resource_entry.original_size = buf_size;
991 lte.resource_entry.size = buf_size;
992 lte.resource_entry.offset = 0;
993 lte.resource_location = RESOURCE_IN_ATTACHED_BUFFER;
994 lte.attached_buffer = (u8*)buf;
996 zero_out_hash(lte.hash);
997 ret = write_wim_resource(<e, out_fp, out_ctype, out_res_entry);
1000 copy_hash(hash, lte.hash);
1005 * Extracts the first @size bytes of the WIM resource specified by @lte to the
1006 * open file descriptor @fd.
1008 * Returns 0 on success; nonzero on failure.
1010 int extract_wim_resource_to_fd(const struct lookup_table_entry *lte, int fd,
1013 u64 bytes_remaining = size;
1014 u8 buf[min(WIM_CHUNK_SIZE, bytes_remaining)];
1017 u8 hash[SHA1_HASH_SIZE];
1022 while (bytes_remaining) {
1023 u64 to_read = min(bytes_remaining, WIM_CHUNK_SIZE);
1024 ret = read_wim_resource(lte, buf, to_read, offset, false);
1027 sha1_update(&ctx, buf, to_read);
1028 if (full_write(fd, buf, to_read) < to_read) {
1029 ERROR_WITH_ERRNO("Error extracting WIM resource");
1030 return WIMLIB_ERR_WRITE;
1032 bytes_remaining -= to_read;
1035 sha1_final(hash, &ctx);
1036 if (!hashes_equal(hash, lte->hash)) {
1037 ERROR("Invalid checksum on a WIM resource "
1038 "(detected when extracting to external file)");
1039 ERROR("The following WIM resource is invalid:");
1040 print_lookup_table_entry(lte);
1041 return WIMLIB_ERR_INVALID_RESOURCE_HASH;
1047 * Extracts the WIM resource specified by @lte to the open file descriptor @fd.
1049 * Returns 0 on success; nonzero on failure.
1051 int extract_full_wim_resource_to_fd(const struct lookup_table_entry *lte, int fd)
1053 return extract_wim_resource_to_fd(lte, fd, wim_resource_size(lte));
1057 * Copies the file resource specified by the lookup table entry @lte from the
1058 * input WIM to the output WIM that has its FILE * given by
1059 * ((WIMStruct*)wim)->out_fp.
1061 * The output_resource_entry, out_refcnt, and part_number fields of @lte are
1064 * Metadata resources are not copied (they are handled elsewhere for joining and
1067 int copy_resource(struct lookup_table_entry *lte, void *wim)
1072 if ((lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) &&
1076 ret = write_wim_resource(lte, w->out_fp,
1077 wim_resource_compression_type(lte),
1078 <e->output_resource_entry);
1081 lte->out_refcnt = lte->refcnt;
1082 lte->part_number = w->hdr.part_number;
1087 * Writes a dentry's resources, including the main file resource as well as all
1088 * alternate data streams, to the output file.
1090 * @dentry: The dentry for the file.
1091 * @wim_p: A pointer to the WIMStruct containing @dentry.
1093 * @return zero on success, nonzero on failure.
1095 int write_dentry_resources(struct dentry *dentry, void *wim_p)
1097 WIMStruct *w = wim_p;
1099 struct lookup_table_entry *lte;
1100 int ctype = wimlib_get_compression_type(w);
1102 if (w->write_flags & WIMLIB_WRITE_FLAG_VERBOSE) {
1103 wimlib_assert(dentry->full_path_utf8);
1104 printf("Writing streams for `%s'\n", dentry->full_path_utf8);
1107 for (unsigned i = 0; i <= dentry->d_inode->num_ads; i++) {
1108 lte = inode_stream_lte(dentry->d_inode, i, w->lookup_table);
1109 if (lte && ++lte->out_refcnt == 1) {
1110 ret = write_wim_resource(lte, w->out_fp, ctype,
1111 <e->output_resource_entry);
1120 * Reads the metadata metadata resource from the WIM file. The metadata
1121 * resource consists of the security data, followed by the directory entry for
1122 * the root directory, followed by all the other directory entries in the
1123 * filesystem. The subdir_offset field of each directory entry gives the start
1124 * of its child entries from the beginning of the metadata resource. An
1125 * end-of-directory is signaled by a directory entry of length '0', really of
1126 * length 8, because that's how long the 'length' field is.
1128 * @fp: The FILE* for the input WIM file.
1129 * @wim_ctype: The compression type of the WIM file.
1130 * @imd: Pointer to the image metadata structure. Its `metadata_lte'
1131 * member specifies the lookup table entry for the metadata
1132 * resource. The rest of the image metadata entry will be filled
1133 * in by this function.
1135 * @return: Zero on success, nonzero on failure.
1137 int read_metadata_resource(WIMStruct *w, struct image_metadata *imd)
1142 struct dentry *dentry;
1143 struct inode_table inode_tab;
1144 const struct lookup_table_entry *metadata_lte;
1146 u64 metadata_offset;
1147 struct hlist_head inode_list;
1149 metadata_lte = imd->metadata_lte;
1150 metadata_len = wim_resource_size(metadata_lte);
1151 metadata_offset = metadata_lte->resource_entry.offset;
1153 DEBUG("Reading metadata resource: length = %"PRIu64", "
1154 "offset = %"PRIu64"", metadata_len, metadata_offset);
1156 /* There is no way the metadata resource could possibly be less than (8
1157 * + WIM_DENTRY_DISK_SIZE) bytes, where the 8 is for security data (with
1158 * no security descriptors) and WIM_DENTRY_DISK_SIZE is for the root
1160 if (metadata_len < 8 + WIM_DENTRY_DISK_SIZE) {
1161 ERROR("Expected at least %u bytes for the metadata resource",
1162 8 + WIM_DENTRY_DISK_SIZE);
1163 return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
1166 if (sizeof(size_t) < 8 && metadata_len > 0xffffffff) {
1167 ERROR("Metadata resource is too large (%"PRIu64" bytes",
1169 return WIMLIB_ERR_INVALID_RESOURCE_SIZE;
1172 /* Allocate memory for the uncompressed metadata resource. */
1173 buf = MALLOC(metadata_len);
1176 ERROR("Failed to allocate %"PRIu64" bytes for uncompressed "
1177 "metadata resource", metadata_len);
1178 return WIMLIB_ERR_NOMEM;
1181 /* Read the metadata resource into memory. (It may be compressed.) */
1182 ret = read_full_wim_resource(metadata_lte, buf);
1186 DEBUG("Finished reading metadata resource into memory.");
1188 /* The root directory entry starts after security data, aligned on an
1189 * 8-byte boundary within the metadata resource.
1191 * The security data starts with a 4-byte integer giving its total
1192 * length, so if we round that up to an 8-byte boundary that gives us
1193 * the offset of the root dentry.
1195 * Here we read the security data into a wim_security_data structure,
1196 * and if successful, go ahead and calculate the offset in the metadata
1197 * resource of the root dentry. */
1199 wimlib_assert(imd->security_data == NULL);
1200 ret = read_security_data(buf, metadata_len, &imd->security_data);
1204 dentry_offset = (imd->security_data->total_length + 7) & ~7;
1206 if (dentry_offset == 0) {
1207 ERROR("Integer overflow while reading metadata resource");
1208 ret = WIMLIB_ERR_INVALID_SECURITY_DATA;
1209 goto out_free_security_data;
1212 /* Allocate memory for the root dentry and read it into memory */
1213 dentry = MALLOC(sizeof(struct dentry));
1215 ERROR("Failed to allocate %zu bytes for root dentry",
1216 sizeof(struct dentry));
1217 ret = WIMLIB_ERR_NOMEM;
1218 goto out_free_security_data;
1221 ret = read_dentry(buf, metadata_len, dentry_offset, dentry);
1223 /* This is the root dentry, so set its parent to itself. */
1224 dentry->parent = dentry;
1227 goto out_free_dentry_tree;
1228 inode_add_dentry(dentry, dentry->d_inode);
1230 /* Now read the entire directory entry tree into memory. */
1231 DEBUG("Reading dentry tree");
1232 ret = read_dentry_tree(buf, metadata_len, dentry);
1234 goto out_free_dentry_tree;
1236 /* Calculate the full paths in the dentry tree. */
1237 DEBUG("Calculating dentry full paths");
1238 ret = for_dentry_in_tree(dentry, calculate_dentry_full_path, NULL);
1240 goto out_free_dentry_tree;
1242 /* Build hash table that maps hard link group IDs to dentry sets */
1243 DEBUG("Building link group table");
1244 ret = init_inode_table(&inode_tab, 9001);
1246 goto out_free_dentry_tree;
1248 for_dentry_in_tree(dentry, inode_table_insert, &inode_tab);
1250 DEBUG("Fixing inconsistencies in the hard link groups");
1251 ret = fix_inodes(&inode_tab, &inode_list);
1252 destroy_inode_table(&inode_tab);
1254 goto out_free_dentry_tree;
1256 DEBUG("Running miscellaneous verifications on the dentry tree");
1257 for_lookup_table_entry(w->lookup_table, lte_zero_real_refcnt, NULL);
1258 ret = for_dentry_in_tree(dentry, verify_dentry, w);
1260 goto out_free_dentry_tree;
1262 DEBUG("Done reading image metadata");
1264 imd->root_dentry = dentry;
1265 imd->inode_list = inode_list;
1267 out_free_dentry_tree:
1268 free_dentry_tree(dentry, NULL);
1269 out_free_security_data:
1270 free_security_data(imd->security_data);
1271 imd->security_data = NULL;
1277 /* Write the metadata resource for the current WIM image. */
1278 int write_metadata_resource(WIMStruct *w)
1284 struct dentry *root;
1285 struct lookup_table_entry *lte;
1286 u64 metadata_original_size;
1287 const struct wim_security_data *sd;
1289 DEBUG("Writing metadata resource for image %d", w->current_image);
1291 root = wim_root_dentry(w);
1292 sd = wim_security_data(w);
1294 /* We do not allow the security data pointer to be NULL, although it may
1295 * point to an empty security data with no entries. */
1296 wimlib_assert(root != NULL);
1297 wimlib_assert(sd != NULL);
1299 /* Offset of first child of the root dentry. It's equal to:
1300 * - The total length of the security data, rounded to the next 8-byte
1302 * - plus the total length of the root dentry,
1303 * - plus 8 bytes for an end-of-directory entry following the root
1304 * dentry (shouldn't really be needed, but just in case...)
1306 subdir_offset = ((sd->total_length + 7) & ~7) +
1307 dentry_correct_total_length(root) + 8;
1309 /* Calculate the subdirectory offsets for the entire dentry tree. */
1310 calculate_subdir_offsets(root, &subdir_offset);
1312 /* Total length of the metadata resource (uncompressed) */
1313 metadata_original_size = subdir_offset;
1315 /* Allocate a buffer to contain the uncompressed metadata resource */
1316 buf = MALLOC(metadata_original_size);
1318 ERROR("Failed to allocate %"PRIu64" bytes for "
1319 "metadata resource", metadata_original_size);
1320 return WIMLIB_ERR_NOMEM;
1323 /* Write the security data into the resource buffer */
1324 p = write_security_data(sd, buf);
1326 /* Write the dentry tree into the resource buffer */
1327 p = write_dentry_tree(root, p);
1329 /* We MUST have exactly filled the buffer; otherwise we calculated its
1330 * size incorrectly or wrote the data incorrectly. */
1331 wimlib_assert(p - buf == metadata_original_size);
1333 /* Get the lookup table entry for the metadata resource so we can update
1335 lte = wim_metadata_lookup_table_entry(w);
1337 wimlib_assert(lte != NULL);
1339 /* Write the metadata resource to the output WIM using the proper
1340 * compression type. The lookup table entry for the metadata resource
1342 ret = write_wim_resource_from_buffer(buf, metadata_original_size,
1344 wimlib_get_compression_type(w),
1345 <e->output_resource_entry,
1350 /* It's very likely the SHA1 message digest of the metadata resource
1351 * changed, so re-insert the lookup table entry into the lookup table.
1353 * We do not check for other lookup table entries having the same SHA1
1354 * message digest. It's possible for 2 absolutely identical images to
1355 * be added, therefore causing 2 identical metadata resources to be in
1356 * the WIM. However, in this case, it's expected for 2 separate lookup
1357 * table entries to be created, even though this doesn't make a whole
1358 * lot of sense since they will share the same SHA1 message digest.
1360 lookup_table_unlink(w->lookup_table, lte);
1361 lookup_table_insert(w->lookup_table, lte);
1363 wimlib_assert(lte->out_refcnt == 0);
1364 lte->out_refcnt = 1;
1366 /* Make sure that the resource entry is written marked with the metadata
1368 lte->output_resource_entry.flags |= WIM_RESHDR_FLAG_METADATA;
1370 /* All the data has been written to the new WIM; no need for the buffer