/* * resource.c * * Read uncompressed and compressed metadata and file resources. */ /* * Copyright (C) 2010 Carl Thijssen * Copyright (C) 2012 Eric Biggers * * This file is part of wimlib, a library for working with WIM files. * * wimlib is free software; you can redistribute it and/or modify it under the * terms of the GNU Lesser General Public License as published by the Free * Software Foundation; either version 2.1 of the License, or (at your option) * any later version. * * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more * details. * * You should have received a copy of the GNU Lesser General Public License * along with wimlib; if not, see http://www.gnu.org/licenses/. */ #include "wimlib_internal.h" #include "lookup_table.h" #include "io.h" #include "lzx.h" #include "xpress.h" #include "sha1.h" #include "dentry.h" #include "config.h" #include #include /* * Reads all or part of a compressed resource into an in-memory buffer. * * @fp: The FILE* for the WIM file. * @resource_compressed_size: The compressed size of the resource. * @resource_uncompressed_size: The uncompressed size of the resource. * @resource_offset: The offset of the start of the resource from * the start of the stream @fp. * @resource_ctype: The compression type of the resource. * @len: The number of bytes of uncompressed data to read from * the resource. * @offset: The offset of the bytes to read within the uncompressed * resource. * @contents_len: An array into which the uncompressed data is written. * It must be at least @len bytes long. * * Returns zero on success, nonzero on failure. */ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, u64 resource_uncompressed_size, u64 resource_offset, int resource_ctype, u64 len, u64 offset, u8 contents_ret[]) { DEBUG2("comp size = %"PRIu64", uncomp size = %"PRIu64", " "res offset = %"PRIu64"", resource_compressed_size, resource_uncompressed_size, resource_offset); DEBUG2("resource_ctype = %s, len = %"PRIu64", offset = %"PRIu64"", wimlib_get_compression_type_string(resource_ctype), len, offset); /* Trivial case */ if (len == 0) return 0; int (*decompress)(const void *, uint, void *, uint); /* Set the appropriate decompress function. */ if (resource_ctype == WIM_COMPRESSION_TYPE_LZX) decompress = lzx_decompress; else decompress = 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. */ /* Calculate how many chunks the resource conists 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; /* 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; /* 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; /* Number of chunks that are actually needed to read the requested part * of the file. */ u64 num_needed_chunks = end_chunk - start_chunk + 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. */ if (end_chunk != num_chunks - 1) num_needed_chunks++; /* Declare the chunk table. It will only contain offsets for the chunks * that are actually needed for this read. */ u64 chunk_offsets[num_needed_chunks]; /* Set the implicit offset of the first chunk if it is included in the * needed chunks. * * Note: M$'s documentation includes a picture that shows the first * chunk starting right after the chunk entry table, labeled as offset * 0x10. However, in the actual file format, the offset is measured * from the end of the chunk entry table, so the first chunk has an * offset of 0. */ if (start_chunk == 0) chunk_offsets[0] = 0; /* According to M$'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; /* Size of the full chunk table in the WIM file. */ u64 chunk_table_size = chunk_entry_size * num_chunk_entries; /* 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. */ 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). */ 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; if (fseeko(fp, file_offset_of_needed_chunk_entries, SEEK_SET) != 0) { ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read " "chunk table of compressed resource", file_offset_of_needed_chunk_entries); return WIMLIB_ERR_READ; } /* Number of bytes we need to read from the chunk table. */ size_t size = num_needed_chunk_entries * chunk_entry_size; u8 chunk_tab_buf[size]; if (fread(chunk_tab_buf, 1, size, fp) != size) goto err; /* 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) { u32 *entries = (u32*)chunk_tab_buf; while (num_needed_chunk_entries--) *chunk_tab_p++ = to_le32(*entries++); } else { u64 *entries = (u64*)chunk_tab_buf; while (num_needed_chunk_entries--) *chunk_tab_p++ = to_le64(*entries++); } /* Done with the chunk table now. We must now seek to the first chunk * that is needed for the read. */ u64 file_offset_of_first_needed_chunk = resource_offset + chunk_table_size + chunk_offsets[0]; if (fseeko(fp, file_offset_of_first_needed_chunk, SEEK_SET) != 0) { ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read " "first chunk of compressed resource", file_offset_of_first_needed_chunk); return WIMLIB_ERR_READ; } /* Pointer to current position in the output buffer for uncompressed * data. */ u8 *out_p = (u8*)contents_ret; /* 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. */ u8 compressed_buf[WIM_CHUNK_SIZE - 1]; /* Decompress all the chunks. */ for (u64 i = start_chunk; i <= end_chunk; i++) { DEBUG2("Chunk %"PRIu64" (start %"PRIu64", end %"PRIu64").", i, start_chunk, end_chunk); /* Calculate the sizes of the compressed chunk and of the * uncompressed chunk. */ uint compressed_chunk_size, 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. */ 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 - chunk_table_size - chunk_offsets[i - start_chunk]; 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) uncompressed_chunk_size = WIM_CHUNK_SIZE; } DEBUG2("compressed_chunk_size = %u, " "uncompressed_chunk_size = %u", compressed_chunk_size, uncompressed_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; u64 partial_chunk_size = end_offset + 1 - start_offset; bool is_partial_chunk = (partial_chunk_size != uncompressed_chunk_size); DEBUG2("start_offset = %u, end_offset = %u", start_offset, end_offset); DEBUG2("partial_chunk_size = %u", partial_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) { /* Probably an uncompressed chunk */ if (start_offset != 0) { if (fseeko(fp, start_offset, SEEK_CUR) != 0) { ERROR_WITH_ERRNO("Uncompressed partial " "chunk fseek() error"); return WIMLIB_ERR_READ; } } if (fread(out_p, 1, partial_chunk_size, fp) != partial_chunk_size) goto err; } else { /* Compressed chunk */ int ret; /* Read the compressed data into compressed_buf. */ if (fread(compressed_buf, 1, compressed_chunk_size, fp) != compressed_chunk_size) goto err; /* For partial chunks we must buffer the uncompressed * data because we don't need all of it. */ if (is_partial_chunk) { u8 uncompressed_buf[uncompressed_chunk_size]; ret = decompress(compressed_buf, compressed_chunk_size, uncompressed_buf, uncompressed_chunk_size); if (ret != 0) return WIMLIB_ERR_DECOMPRESSION; memcpy(out_p, uncompressed_buf + start_offset, partial_chunk_size); } else { ret = decompress(compressed_buf, compressed_chunk_size, out_p, uncompressed_chunk_size); if (ret != 0) return WIMLIB_ERR_DECOMPRESSION; } } /* Advance the pointer into the uncompressed output data by the * number of uncompressed bytes that were written. */ out_p += partial_chunk_size; } return 0; err: if (feof(fp)) ERROR("Unexpected EOF in compressed file resource"); else ERROR_WITH_ERRNO("Error reading compressed file resource"); return WIMLIB_ERR_READ; } /* * Reads uncompressed data from an open file stream. */ int read_uncompressed_resource(FILE *fp, u64 offset, u64 len, u8 contents_ret[]) { if (fseeko(fp, offset, SEEK_SET) != 0) { ERROR("Failed to seek to byte %"PRIu64" of input file " "to read uncompressed resource (len = %"PRIu64")", offset, len); return WIMLIB_ERR_READ; } if (fread(contents_ret, 1, len, fp) != len) { if (feof(fp)) { ERROR("Unexpected EOF in uncompressed file resource"); } else { ERROR("Failed to read %"PRIu64" bytes from " "uncompressed resource at offset %"PRIu64, len, offset); } return WIMLIB_ERR_READ; } return 0; } /* * Reads a WIM resource. * * @fp: The FILE* for the WIM file. * @resource_size: The compressed size of the resource. * @resource_original_size: The uncompressed size of the resource. * @resource_offset: The offset of the resource in the stream @fp. * @resource_ctype: The compression type of the resource. * (WIM_COMPRESSION_TYPE_*) * @len: How many bytes of the resource should be read. * @offset: The offset within the resource at which the read * will occur. * * To read the whole file resource, specify offset = * 0 and len = resource_original_size, or call * read_full_resource(). * * @contents_ret: An array, that must have length at least @len, * into which the uncompressed contents of * the file resource starting at @offset and * continuing for @len bytes will be written. * * @return: Zero on success, nonzero on failure. Failure may be due to * being unable to read the data from the WIM file at the * specified length and offset, or it may be due to the * compressed data (if the data is compressed) being * invalid. */ int read_resource(FILE *fp, u64 resource_size, u64 resource_original_size, u64 resource_offset, int resource_ctype, u64 len, u64 offset, void *contents_ret) { if (resource_ctype == WIM_COMPRESSION_TYPE_NONE) { if (resource_size != resource_original_size) { ERROR("Resource with original size %"PRIu64" bytes is " "marked as uncompressed, but its actual size is " "%"PRIu64" bytes", resource_size); return WIMLIB_ERR_INVALID_RESOURCE_SIZE; } return read_uncompressed_resource(fp, resource_offset + offset, len, contents_ret); } else { return read_compressed_resource(fp, resource_size, resource_original_size, resource_offset, resource_ctype, len, offset, contents_ret); } } /* * Extracts the first @size bytes file resource specified by @entry to the open * file @fd. Returns nonzero on error. * * XXX * This function is somewhat redundant with uncompress_resource(). The * main difference is that this function writes to a file descriptor using * low-level calls to write() rather than to a FILE* with fwrite(); also this * function allows only up to @size bytes to be extracted. */ int extract_resource_to_fd(WIMStruct *w, const struct resource_entry *entry, int fd, u64 size) { u64 num_chunks; u64 n; u8 buf[min(size, WIM_CHUNK_SIZE)]; int res_ctype; u64 offset; u64 i; int ret; errno = 0; num_chunks = (size + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE; n = WIM_CHUNK_SIZE; res_ctype = wim_resource_compression_type(w, entry); offset = 0; for (i = 0; i < num_chunks; i++) { if (i == num_chunks - 1) { n = size % WIM_CHUNK_SIZE; if (n == 0) { n = WIM_CHUNK_SIZE; } } ret = read_resource(w->fp, entry->size, entry->original_size, entry->offset, res_ctype, n, offset, buf); if (ret != 0) return ret; if (full_write(fd, buf, n) != n) return WIMLIB_ERR_WRITE; offset += n; } return ret; } /* * 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. * * 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). */ int copy_resource(struct lookup_table_entry *lte, void *w) { if ((lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) && !((WIMStruct*)w)->write_metadata) { return 0; } FILE *in_fp = ((WIMStruct*)w)->fp; FILE *out_fp = ((WIMStruct*)w)->out_fp; int ret; u64 size = lte->resource_entry.size; u64 offset = lte->resource_entry.offset; off_t new_offset = ftello(out_fp); if (new_offset == -1) return WIMLIB_ERR_WRITE; ret = copy_between_files(in_fp, offset, out_fp, size); if (ret != 0) return ret; memcpy(<e->output_resource_entry, <e->resource_entry, sizeof(struct resource_entry)); lte->output_resource_entry.offset = new_offset; lte->out_refcnt = lte->refcnt; lte->part_number = ((WIMStruct*)w)->hdr.part_number; 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. */ const u8 *get_resource_entry(const u8 *p, struct resource_entry *entry) { u64 size; u8 flags; p = get_u56(p, &size); p = get_u8(p, &flags); entry->size = size; entry->flags = flags; p = get_u64(p, &entry->offset); p = get_u64(p, &entry->original_size); return p; } /* Copies the struct resource_entry @entry to the memory pointed to by @p in the * on-disk format. A pointer to the byte after the memory written at @p is * returned. */ u8 *put_resource_entry(u8 *p, const struct resource_entry *entry) { p = put_u56(p, entry->size); p = put_u8(p, entry->flags); p = put_u64(p, entry->offset); p = put_u64(p, entry->original_size); return p; } /* Given the compression type for the WIM file as a whole as the flags field of * a resource entry, returns the compression type for that resource entry. */ int resource_compression_type(int wim_ctype, int reshdr_flags) { if (wim_ctype != WIM_COMPRESSION_TYPE_NONE && (reshdr_flags & WIM_RESHDR_FLAG_COMPRESSED)) return wim_ctype; else return WIM_COMPRESSION_TYPE_NONE; } /* * Copies bytes between two file streams. * * Copies @len bytes from @in_fp to @out_fp, at the current position in @out_fp, * and at an offset of @in_offset in @in_fp. */ int copy_between_files(FILE *in_fp, off_t in_offset, FILE *out_fp, size_t len) { u8 buf[BUFFER_SIZE]; size_t n; if (fseeko(in_fp, in_offset, SEEK_SET) != 0) { ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of " "input file", in_offset); return WIMLIB_ERR_READ; } /* To reduce memory usage and improve speed, read and write BUFFER_SIZE * bytes at a time. */ while (len != 0) { n = min(len, BUFFER_SIZE); if (fread(buf, 1, n, in_fp) != n) { if (feof(in_fp)) { ERROR("Unexpected EOF when copying data " "between files"); } else { ERROR_WITH_ERRNO("Error copying data between " "files"); } return WIMLIB_ERR_READ; } if (fwrite(buf, 1, n, out_fp) != n) { ERROR_WITH_ERRNO("Error copying data between files"); return WIMLIB_ERR_WRITE; } len -= n; } return 0; } /* * Uncompresses a WIM file resource and writes it uncompressed to a file stream. * * @in_fp: The file stream that contains the file resource. * @size: The size of the resource in the input file. * @original_size: The original (uncompressed) size of the resource. * @offset: The offset of the start of the resource in @in. * @input_ctype: The compression type of the resource in @in. * @out_fp: The file stream to write the file resource to. */ static int uncompress_resource(FILE *in_fp, u64 size, u64 original_size, off_t offset, int input_ctype, FILE *out_fp) { int ret; u8 buf[WIM_CHUNK_SIZE]; /* Determine how many compressed chunks the file is divided into. */ u64 num_chunks; u64 i; u64 uncompressed_offset; u64 uncompressed_chunk_size; num_chunks = (original_size + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE; for (i = 0; i < num_chunks; i++) { uncompressed_offset = i * WIM_CHUNK_SIZE; uncompressed_chunk_size = min(WIM_CHUNK_SIZE, original_size - uncompressed_offset); ret = read_resource(in_fp, size, original_size, offset, input_ctype, uncompressed_chunk_size, uncompressed_offset, buf); if (ret != 0) return ret; if (fwrite(buf, 1, uncompressed_chunk_size, out_fp) != uncompressed_chunk_size) { ERROR_WITH_ERRNO("Failed to write file resource"); return WIMLIB_ERR_WRITE; } } return 0; } /* * Transfers a file resource between two files, writing it compressed. The file * resource in the input file may be either compressed or uncompressed. * Alternatively, the input resource may be in-memory, but it must be * uncompressed. * * @in_fp: The file stream that contains the file resource. Ignored * if uncompressed_resource != NULL. * @uncompressed_resource: If this pointer is not NULL, it points to an * array of @original_size bytes that are * the uncompressed input resource. * @size: The size of the resource in the input file. * @original_size: The original (uncompressed) size of the resource. * @offset: The offset of the start of the resource in @in. Ignored * if uncompressed_resource != NULL. * @input_ctype: The compression type of the resource in @in. Ignored if * uncompressed_resource != NULL. * @out_fp: The file stream to write the file resource to. * @output_type: The compression type to use when writing the resource to * @out. * @new_size_ret: A location into which the new compressed size of the file * resource in returned. */ static int recompress_resource(FILE *in_fp, const u8 *uncompressed_resource, u64 size, u64 original_size, off_t offset, int input_ctype, FILE *out_fp, int output_ctype, u64 *new_size_ret) { int ret; int (*compress)(const void *, uint, void *, uint *); if (output_ctype == WIM_COMPRESSION_TYPE_LZX) compress = lzx_compress; else compress = xpress_compress; u8 uncompressed_buf[WIM_CHUNK_SIZE]; u8 compressed_buf[WIM_CHUNK_SIZE - 1]; /* Determine how many compressed chunks the file needs to be divided * into. */ u64 num_chunks = (original_size + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE; u64 num_chunk_entries = num_chunks - 1; /* Size of the chunk entries--- 8 bytes for files over 4GB, otherwise 4 * bytes */ uint chunk_entry_size = (original_size >= (u64)1 << 32) ? 8 : 4; /* Array in which to construct the chunk offset table. */ u64 chunk_offsets[num_chunk_entries]; /* Offset of the start of the chunk table in the output file. */ off_t chunk_tab_offset = ftello(out_fp); if (chunk_tab_offset == -1) { ERROR_WITH_ERRNO("Failed to get offset of output file"); return WIMLIB_ERR_WRITE; } /* Total size of the chunk table (as written to the file) */ u64 chunk_tab_size = chunk_entry_size * num_chunk_entries; /* Reserve space for the chunk table. */ if (fwrite(chunk_offsets, 1, chunk_tab_size, out_fp) != chunk_tab_size) { ERROR_WITH_ERRNO("Failed to write chunk offset table"); return WIMLIB_ERR_WRITE; } /* Read each chunk of the file, compress it, write it to the output * file, and update th chunk offset table. */ u64 cur_chunk_offset = 0; for (u64 i = 0; i < num_chunks; i++) { u64 uncompressed_offset = i * WIM_CHUNK_SIZE; u64 uncompressed_chunk_size = min(WIM_CHUNK_SIZE, original_size - uncompressed_offset); const u8 *uncompressed_p; if (uncompressed_resource != NULL) { uncompressed_p = uncompressed_resource + uncompressed_offset; } else { /* Read chunk i of the file into uncompressed_buf. */ ret = read_resource(in_fp, size, original_size, offset, input_ctype, uncompressed_chunk_size, uncompressed_offset, uncompressed_buf); if (ret != 0) return ret; uncompressed_p = uncompressed_buf; } if (i != 0) chunk_offsets[i - 1] = cur_chunk_offset; uint compressed_len; ret = compress(uncompressed_p, uncompressed_chunk_size, compressed_buf, &compressed_len); /* if compress() returned nonzero, the compressed chunk would * have been at least as large as the uncompressed chunk. In * this situation, the WIM format requires that the uncompressed * chunk be written instead. */ const u8 *buf_to_write; uint len_to_write; if (ret == 0) { buf_to_write = compressed_buf; len_to_write = compressed_len; } else { buf_to_write = uncompressed_p; len_to_write = uncompressed_chunk_size; } if (fwrite(buf_to_write, 1, len_to_write, out_fp) != len_to_write) { ERROR_WITH_ERRNO("Failed to write compressed " "file resource"); return WIMLIB_ERR_WRITE; } cur_chunk_offset += len_to_write; } /* The chunk offset after the last chunk, plus the size of the chunk * table, gives the total compressed size of the resource. */ *new_size_ret = cur_chunk_offset + chunk_tab_size; /* Now that all entries of the chunk table are determined, rewind the * stream to where the chunk table was, and write it back out. */ if (fseeko(out_fp, chunk_tab_offset, SEEK_SET) != 0) { ERROR_WITH_ERRNO("Failed to seek to beginning of chunk table"); return WIMLIB_ERR_READ; } if (chunk_entry_size == 8) { array_to_le64(chunk_offsets, num_chunk_entries); } else { for (u64 i = 0; i < num_chunk_entries; i++) ((u32*)chunk_offsets)[i] = to_le32(chunk_offsets[i]); } if (fwrite(chunk_offsets, 1, chunk_tab_size, out_fp) != chunk_tab_size) { ERROR_WITH_ERRNO("Failed to write chunk table"); return WIMLIB_ERR_WRITE; } if (fseeko(out_fp, 0, SEEK_END) != 0) { ERROR_WITH_ERRNO("Failed to seek to end of output file"); return WIMLIB_ERR_WRITE; } return 0; } int write_resource_from_memory(const u8 resource[], int out_ctype, u64 resource_original_size, FILE *out_fp, u64 *resource_size_ret) { if (out_ctype == WIM_COMPRESSION_TYPE_NONE) { if (fwrite(resource, 1, resource_original_size, out_fp) != resource_original_size) { ERROR_WITH_ERRNO("Failed to write resource of length " "%"PRIu64, resource_original_size); return WIMLIB_ERR_WRITE; } *resource_size_ret = resource_original_size; return 0; } else { return recompress_resource(NULL, resource, resource_original_size, resource_original_size, 0, 0, out_fp, out_ctype, resource_size_ret); } } /* * Transfers a file resource from a FILE* opened for reading to a FILE* opened * for writing, possibly changing the compression type. * * @in_fp: The FILE* that contains the file resource. * @size: The (compressed) size of the file resource. * @original_size: The uncompressed size of the file resource. * @offset: The offset of the file resource in the input file. * @input_ctype: The compression type of the file resource in the input * file. * @out_fp: The FILE* for the output file. The file resource is * written at the current position of @out. * @output_ctype: The compression type to which the file resource will be * converted. * @output_res_entry: A pointer to a resource entry that, upon successful * return of this function, will have the size, * original size, offset, and flags fields filled * in for the file resource written to the output * file. */ static int transfer_file_resource(FILE *in_fp, u64 size, u64 original_size, off_t offset, int input_ctype, FILE *out_fp, int output_ctype, struct resource_entry *output_res_entry) { int ret; /* Handle zero-length files */ if (original_size == 0) { memset(output_res_entry, 0, sizeof(*output_res_entry)); return 0; } /* Get current offset in the output file. */ off_t out_offset = ftello(out_fp); if (out_offset == -1) { ERROR_WITH_ERRNO("Failed to get output position"); return WIMLIB_ERR_WRITE; } output_res_entry->offset = (u64)out_offset; if (output_ctype == input_ctype) { /* The same compression types; simply copy the resource. */ ret = copy_between_files(in_fp, offset, out_fp, size); if (ret != 0) return ret; output_res_entry->size = size; } else { /* Different compression types. */ if (output_ctype == WIM_COMPRESSION_TYPE_NONE) { /* Uncompress a compressed file resource */ ret = uncompress_resource(in_fp, size, original_size, offset, input_ctype, out_fp); if (ret != 0) return ret; output_res_entry->size = original_size; } else { u64 new_size; /* Compress an uncompressed file resource, or compress a * compressed file resource using a different * compression type */ ret = recompress_resource(in_fp, NULL, size, original_size, offset, input_ctype, out_fp, output_ctype, &new_size); if (ret != 0) return ret; output_res_entry->size = new_size; } } output_res_entry->original_size = original_size; if (output_ctype == WIM_COMPRESSION_TYPE_NONE) output_res_entry->flags = 0; else output_res_entry->flags = WIM_RESHDR_FLAG_COMPRESSED; 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 * `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. * * @return: Zero on success, nonzero on failure. */ int read_metadata_resource(FILE *fp, int wim_ctype, struct image_metadata *imd) { u8 *buf; int ctype; u32 dentry_offset; int ret; const struct resource_entry *res_entry; struct dentry *dentry; #ifdef ENABLE_SECURITY_DATA struct wim_security_data *sd; #endif res_entry = &imd->metadata_lte->resource_entry; DEBUG("Reading metadata resource: length = %"PRIu64", " "offset = %"PRIu64"", res_entry->original_size, res_entry->offset); if (res_entry->original_size < 8) { ERROR("Expected at least 8 bytes for the metadata resource"); return WIMLIB_ERR_INVALID_RESOURCE_SIZE; } /* Allocate memory for the uncompressed metadata resource. */ buf = MALLOC(res_entry->original_size); if (!buf) { ERROR("Failed to allocate %"PRIu64" bytes for uncompressed " "metadata resource", res_entry->original_size); return WIMLIB_ERR_NOMEM; } /* Determine the compression type of the metadata resource. */ ctype = resource_compression_type(wim_ctype, res_entry->flags); /* Read the metadata resource into memory. (It may be compressed.) */ ret = read_full_resource(fp, res_entry->size, res_entry->original_size, res_entry->offset, ctype, buf); if (ret != 0) goto out_free_buf; DEBUG("Finished reading metadata resource into memory."); /* The root directory entry starts after security data, on an 8-byte * aligned address. * * The security data starts with a 4-byte integer giving its total * length. */ #ifdef ENABLE_SECURITY_DATA /* Read the security data into a wim_security_data structure. */ ret = read_security_data(buf, res_entry->original_size, &sd); if (ret != 0) goto out_free_buf; #endif 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; } get_u32(buf, &dentry_offset); if (dentry_offset == 0) dentry_offset = 8; dentry_offset = (dentry_offset + 7) & ~7; ret = read_dentry(buf, res_entry->original_size, dentry_offset, dentry); /* This is the root dentry, so set its pointers correctly. */ dentry->parent = dentry; dentry->next = dentry; dentry->prev = dentry; if (ret != 0) goto out_free_dentry_tree; /* Now read the entire directory entry tree. */ ret = read_dentry_tree(buf, res_entry->original_size, dentry); if (ret != 0) goto out_free_dentry_tree; /* Calculate the full paths in the dentry tree. */ ret = for_dentry_in_tree(dentry, calculate_dentry_full_path, NULL); if (ret != 0) goto out_free_dentry_tree; #ifdef ENABLE_SECURITY_DATA imd->security_data = sd; #endif imd->root_dentry = dentry; goto out_free_buf; out_free_security_data: #ifdef ENABLE_SECURITY_DATA free_security_data(sd); #endif out_free_dentry_tree: free_dentry_tree(dentry, NULL, false); out_free_buf: FREE(buf); return ret; } /* Write the metadata resource for the current image. */ int write_metadata_resource(WIMStruct *w) { FILE *out; u8 *buf; u8 *p; int ret; u64 subdir_offset; struct dentry *root; struct lookup_table_entry *lte; struct resource_entry *res_entry; off_t metadata_offset; u64 metadata_original_size; u64 metadata_compressed_size; int metadata_ctype; u8 hash[WIM_HASH_SIZE]; DEBUG("Writing metadata resource for image %d", w->current_image); out = w->out_fp; root = wim_root_dentry(w); metadata_ctype = wimlib_get_compression_type(w); metadata_offset = ftello(out); if (metadata_offset == -1) return WIMLIB_ERR_WRITE; #ifdef ENABLE_SECURITY_DATA struct wim_security_data *sd = wim_security_data(w); if (sd) subdir_offset = sd->total_length + root->length + 8; else #endif subdir_offset = 8 + root->length + 8; calculate_subdir_offsets(root, &subdir_offset); metadata_original_size = subdir_offset; buf = MALLOC(metadata_original_size); if (!buf) { ERROR("Failed to allocate %"PRIu64" bytes for " "metadata resource", metadata_original_size); return WIMLIB_ERR_NOMEM; } #ifdef ENABLE_SECURITY_DATA /* Write the security data. */ p = write_security_data(sd, buf); #else p = put_u32(buf, 8); /* Total length of security data. */ p = put_u32(p, 0); /* Number of security data entries. */ #endif DEBUG("Writing dentry tree."); p = write_dentry_tree(root, p); /* Like file resources, the lookup table entry for a metadata resource * uses for the hash code a SHA1 message digest of its uncompressed * contents. */ sha1_buffer(buf, metadata_original_size, hash); ret = write_resource_from_memory(buf, metadata_ctype, metadata_original_size, out, &metadata_compressed_size); FREE(buf); if (ret != 0) return ret; /* Update the lookup table entry, including the hash and output resource * entry fields, for this image's metadata resource. */ lte = wim_metadata_lookup_table_entry(w); res_entry = <e->output_resource_entry; lte->out_refcnt++; if (memcmp(hash, lte->hash, WIM_HASH_SIZE) != 0) { lookup_table_unlink(w->lookup_table, lte); memcpy(lte->hash, hash, WIM_HASH_SIZE); lookup_table_insert(w->lookup_table, lte); } res_entry->original_size = metadata_original_size; res_entry->offset = metadata_offset; res_entry->size = metadata_compressed_size; res_entry->flags = WIM_RESHDR_FLAG_METADATA; if (metadata_ctype != WIM_COMPRESSION_TYPE_NONE) res_entry->flags |= WIM_RESHDR_FLAG_COMPRESSED; return 0; } /* * Writes a file resource to the output file. * * @dentry: The dentry for the file resource. * @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. * * @return zero on success, nonzero on failure. */ int write_file_resource(struct dentry *dentry, void *wim_p) { WIMStruct *w; FILE *out_fp; FILE *in_fp; struct lookup_table_entry *lte; int in_wim_ctype; int out_wim_ctype; struct resource_entry *output_res_entry; u64 len; int ret; w = wim_p; out_fp = w->out_fp; /* Directories don't need file resources. */ if (dentry_is_directory(dentry)) return 0; /* Get the lookup entry for the file resource. */ lte = wim_lookup_resource(w, dentry); if (!lte) return 0; /* No need to write file resources twice. (This indicates file * resources that are part of a hard link set.) */ if (++lte->out_refcnt != 1) return 0; out_wim_ctype = wimlib_get_compression_type(w); output_res_entry = <e->output_resource_entry; /* do not write empty resources */ if (lte->resource_entry.original_size == 0) return 0; /* Figure out if we can read the resource from the WIM file, or * if we have to read it from the filesystem outside. */ if (lte->file_on_disk) { /* Read from disk (uncompressed) */ len = lte->resource_entry.original_size; in_fp = fopen(lte->file_on_disk, "rb"); if (!in_fp) { ERROR_WITH_ERRNO("Failed to open the file `%s'", lte->file_on_disk); return WIMLIB_ERR_OPEN; } if (w->verbose) puts(lte->file_on_disk); ret = transfer_file_resource(in_fp, len, len, 0, WIM_COMPRESSION_TYPE_NONE, out_fp, out_wim_ctype, output_res_entry); fclose(in_fp); } else { /* Read from input WIM (possibly compressed) */ /* It may be a different WIM file, in the case of * exporting images from one WIM file to another */ if (lte->other_wim_fp) { /* Different WIM file. */ in_fp = lte->other_wim_fp; in_wim_ctype = lte->other_wim_ctype; } else { /* Same WIM file. */ in_fp = w->fp; in_wim_ctype = out_wim_ctype; } int input_res_ctype = resource_compression_type( in_wim_ctype, lte->resource_entry.flags); ret = transfer_file_resource(in_fp, lte->resource_entry.size, lte->resource_entry.original_size, lte->resource_entry.offset, input_res_ctype, out_fp, out_wim_ctype, output_res_entry); } return ret; }