X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Fresource.c;h=bb3dda97aca9099ae35727bc64905c961fd9ca62;hb=bf146b03ed91788ebc56ecf97a7a1e13d780d961;hp=03754e08d41877e06f82c8213ebdb45800678456;hpb=815ad485b8ce48db48a3137d73e511f6c9af868c;p=wimlib diff --git a/src/resource.c b/src/resource.c index 03754e08..bb3dda97 100644 --- a/src/resource.c +++ b/src/resource.c @@ -1,1221 +1,1080 @@ /* * resource.c * - * Read uncompressed and compressed metadata and file resources. + * Read uncompressed and compressed metadata and file resources from a WIM file. */ /* - * Copyright (C) 2010 Carl Thijssen - * Copyright (C) 2012 Eric Biggers + * Copyright (C) 2012, 2013 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. + * terms of the GNU General Public License as published by the Free Software + * Foundation; either version 3 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. + * A PARTICULAR PURPOSE. See the GNU 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/. + * You should have received a copy of the GNU 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 +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "wimlib.h" +#include "wimlib/dentry.h" +#include "wimlib/endianness.h" +#include "wimlib/error.h" +#include "wimlib/file_io.h" +#include "wimlib/lookup_table.h" +#include "wimlib/resource.h" +#include "wimlib/sha1.h" + +#ifdef __WIN32__ +/* for read_win32_file_prefix(), read_win32_encrypted_file_prefix() */ +# include "wimlib/win32.h" +#endif + +#ifdef WITH_NTFS_3G +/* for read_ntfs_file_prefix() */ +# include "wimlib/ntfs_3g.h" +#endif + +#ifdef HAVE_ALLOCA_H +# include +#endif #include +#include +#include +#include +#include - -/* - * Reads all or part of a compressed resource into an in-memory buffer. +/* + * Compressed resources + * + * 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. * - * @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. + * Additional information: * - * Returns zero on success, nonzero on failure. + * - 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. */ -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; +typedef int (*decompress_func_t)(const void *, unsigned, void *, unsigned); - int (*decompress)(const void *, uint, void *, uint); - /* Set the appropriate decompress function. */ - if (resource_ctype == WIM_COMPRESSION_TYPE_LZX) - decompress = lzx_decompress; +static decompress_func_t +get_decompress_func(int ctype) +{ + if (ctype == WIMLIB_COMPRESSION_TYPE_LZX) + return wimlib_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; + 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(const struct wim_lookup_table_entry *lte, + u64 size, consume_data_callback_t cb, + void *ctx_or_buf, int flags, u64 offset) +{ + int ret; - /* 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; + /* 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); + } - /* 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; + wimlib_assert(offset + size <= wim_resource_size(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; + /* Handle the trivial case. */ + if (size == 0) + return 0; - /* 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$'s documentation includes a picture that shows the first - * chunk starting right after the chunk entry table, labeled as offset - * 0x10. However, in the actual file format, the offset is measured - * from the end of the chunk entry table, so the first chunk has an - * offset of 0. */ - if (start_chunk == 0) - chunk_offsets[0] = 0; + /* Get the appropriate decompression function. */ + decompress_func_t decompress = + get_decompress_func(wim_resource_compression_type(lte)); - /* According to M$'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; + /* Get the file descriptor for the WIM. */ + struct filedes *in_fd = <e->wim->in_fd; - /* Size of the full chunk table in the WIM file. */ - u64 chunk_table_size = chunk_entry_size * num_chunk_entries; + /* Calculate the number of chunks the resource is divided into. */ + u64 num_chunks = wim_resource_chunks(lte); - /* Read the needed chunk offsets from the table in the WIM file. */ + /* 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; - /* 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; + /* Calculate the 0-based index of the chunk at which the read starts. + */ + u64 start_chunk = offset / WIM_CHUNK_SIZE; - /* 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; + /* 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_alloc_chunk_entries++; + + /* 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; + + /* Calculate the size, in bytes, of the full chunk table. */ + u64 chunk_table_size = num_chunk_entries * chunk_entry_size; + + /* 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_alloc_chunk_entries < 1024) { + chunk_offsets = alloca(num_alloc_chunk_entries * sizeof(u64)); + chunk_offsets_malloced = false; + } else { + chunk_offsets = malloc(num_alloc_chunk_entries * sizeof(u64)); + if (!chunk_offsets) { + ERROR("Failed to allocate chunk table " + "with %"PRIu64" entries", num_alloc_chunk_entries); + return WIMLIB_ERR_NOMEM; + } + chunk_offsets_malloced = true; } - /* 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; + /* Set the implicit offset of the first chunk if it's included in the + * needed chunks. */ 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++); - } + chunk_offsets[0] = 0; - /* Done with the chunk table now. We must now seek to the first chunk - * that is needed for the read. */ + /* Calculate the index of the first needed entry in the chunk table. */ + u64 start_table_idx = (start_chunk == 0) ? 0 : start_chunk - 1; - 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; + /* Calculate the number of entries that need to be read from the chunk + * table. */ + u64 num_needed_chunk_entries = (start_chunk == 0) ? + 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_free_chunk_offsets; } - /* 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]; + /* 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_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]); + } + } - /* Decompress all the chunks. */ + /* 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); + + /* 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; + + /* 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++) { - DEBUG2("Chunk %"PRIu64" (start %"PRIu64", end %"PRIu64").", - i, start_chunk, end_chunk); + /* 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. */ - uint compressed_chunk_size, uncompressed_chunk_size; + * 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. */ - compressed_chunk_size = chunk_offsets[i + 1 - start_chunk] - + /* 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; } - 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; + /* 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 { - /* Compressed chunk */ - int ret; + if (i == start_chunk) + start_offset = start_offset_in_chunk; - /* Read the compressed data into compressed_buf. */ - if (fread(compressed_buf, 1, compressed_chunk_size, - fp) != compressed_chunk_size) - goto err; + if (i == end_chunk) + end_offset = end_offset_in_chunk; - /* For partial chunks we must buffer the uncompressed - * data because we don't need all of it. */ - if (is_partial_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 and not doing raw read. */ + + /* 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 (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); - if (ret != 0) - return WIMLIB_ERR_DECOMPRESSION; + ret = (*decompress)(compressed_buf, + compressed_chunk_size, + uncompressed_buf, + uncompressed_chunk_size); + if (ret) { + ERROR("Failed to decompress data."); + ret = WIMLIB_ERR_DECOMPRESSION; + errno = EINVAL; + goto out_free_chunk_offsets; + } memcpy(out_p, uncompressed_buf + start_offset, - partial_chunk_size); + partial_chunk_size); } else { - ret = decompress(compressed_buf, - compressed_chunk_size, - out_p, - uncompressed_chunk_size); - if (ret != 0) - return WIMLIB_ERR_DECOMPRESSION; + ret = (*decompress)(compressed_buf, + compressed_chunk_size, + out_p, + uncompressed_chunk_size); + if (ret) { + ERROR("Failed to decompress data."); + ret = WIMLIB_ERR_DECOMPRESSION; + errno = EINVAL; + goto out_free_chunk_offsets; + } } } - - /* Advance the pointer into the uncompressed output data by the - * number of uncompressed bytes that were written. */ - out_p += partial_chunk_size; + if (cb) { + /* Feed the data to the callback function. */ + ret = cb(out_p + start_offset, + partial_chunk_size, ctx_or_buf); + if (ret) + goto out_free_chunk_offsets; + } else { + /* No callback function provided; we are writing + * directly to a buffer. Advance the pointer into this + * buffer by the number of uncompressed bytes that were + * written. */ + out_p += partial_chunk_size; + } + cur_read_offset += compressed_chunk_size; } - return 0; + ret = 0; +out_free_chunk_offsets: + if (chunk_offsets_malloced) + FREE(chunk_offsets); + return ret; -err: - if (feof(fp)) - ERROR("Unexpected EOF in compressed file resource"); - else - ERROR_WITH_ERRNO("Error reading compressed file resource"); - return WIMLIB_ERR_READ; +read_error: + ERROR_WITH_ERRNO("Error reading compressed file resource"); + goto out_free_chunk_offsets; } -/* - * Reads uncompressed data from an open file stream. - */ -int read_uncompressed_resource(FILE *fp, u64 offset, u64 len, - u8 contents_ret[]) +/* 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) { - 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; + 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; + + 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; } - -/* - * 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) +/* 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) { - 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_original_size, resource_size); - return WIMLIB_ERR_INVALID_RESOURCE_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; + + 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; } - 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); - } -} + /* Read chunk data. */ + ret = full_read(in_fd, cchunk, cchunk_size); + if (ret) + goto read_error; -/* - * 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; + if (flags & WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY) + continue; - 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; + /* 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; } - 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; + /* 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; } -/* - * 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. +/* + * 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). * - * The output_resource_entry, out_refcnt, and part_number fields of @lte are - * updated. + * 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. * - * Metadata resources are not copied (they are handled elsewhere for joining and - * splitting). + * 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 copy_resource(struct lookup_table_entry *lte, void *w) +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) { - 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; + struct filedes *in_fd; 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)); + /* Make sure the resource is actually located in a WIM file and is not + * somewhere else. */ + wimlib_assert(lte->resource_location == RESOURCE_IN_WIM); + + /* 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)) + { + /* Reading raw resource contents or reading uncompressed + * resource. */ + wimlib_assert(offset + size <= lte->resource_entry.size); + offset += lte->resource_entry.offset; + 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); + ret = full_pread(in_fd, buf, bytes_to_read, + offset); + if (ret) + goto read_error; + ret = cb(buf, bytes_to_read, ctx_or_buf); + if (ret) + goto out; + size -= bytes_to_read; + offset += bytes_to_read; + } + } else { + /* Send data directly to a buffer */ + 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; - lte->output_resource_entry.offset = new_offset; - lte->out_refcnt = lte->refcnt; - lte->part_number = ((WIMStruct*)w)->hdr.part_number; - return 0; +read_error: + ERROR_WITH_ERRNO("Error reading data from WIM"); +out: + return ret; } -/* 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) +int +read_partial_wim_resource_into_buf(const struct wim_lookup_table_entry *lte, + size_t size, u64 offset, void *buf) { - 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; + return read_partial_wim_resource(lte, size, NULL, buf, 0, offset); } -/* 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) +static int +read_wim_resource_prefix(const struct wim_lookup_table_entry *lte, + u64 size, + consume_data_callback_t cb, + void *ctx_or_buf, + int flags) { - if (wim_ctype != WIM_COMPRESSION_TYPE_NONE && - (reshdr_flags & WIM_RESHDR_FLAG_COMPRESSED)) - return wim_ctype; - else - return WIM_COMPRESSION_TYPE_NONE; + return read_partial_wim_resource(lte, size, cb, ctx_or_buf, flags, 0); } - -/* - * 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) +#ifndef __WIN32__ +static int +read_file_on_disk_prefix(const struct wim_lookup_table_entry *lte, + u64 size, + consume_data_callback_t cb, + void *ctx_or_buf, + int _ignored_flags) { - u8 buf[BUFFER_SIZE]; - size_t n; + const tchar *filename = lte->file_on_disk; + int ret; + struct filedes fd; + int raw_fd; - 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; - } + DEBUG("Reading %"PRIu64" bytes from \"%"TS"\"", + size, lte->file_on_disk); - if (fwrite(buf, 1, n, out_fp) != n) { - ERROR_WITH_ERRNO("Error copying data between files"); - return WIMLIB_ERR_WRITE; + 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); + ret = full_read(&fd, buf, bytes_to_read); + if (ret) + goto read_error; + ret = cb(buf, bytes_to_read, ctx_or_buf); + if (ret) + goto out_close; + size -= bytes_to_read; } - len -= n; + } else { + /* Send data directly to a buffer */ + ret = full_read(&fd, ctx_or_buf, size); + if (ret) + goto read_error; } - return 0; -} + ret = 0; + goto out_close; +read_error: + ERROR_WITH_ERRNO("Error reading \"%"TS"\"", filename); +out_close: + filedes_close(&fd); + return ret; +} +#endif /* !__WIN32__ */ -/* - * 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) +static int +read_buffer_prefix(const struct wim_lookup_table_entry *lte, + u64 size, consume_data_callback_t cb, + void *ctx_or_buf, int _ignored_flags) { + const void *inbuf = lte->attached_buffer; 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; + if (cb) { + while (size) { + size_t chunk_size = min(WIM_CHUNK_SIZE, size); + ret = cb(inbuf, chunk_size, ctx_or_buf); + if (ret) + return ret; + size -= chunk_size; + inbuf += chunk_size; } + } else { + memcpy(ctx_or_buf, inbuf, size); } 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. +typedef int (*read_resource_prefix_handler_t)(const struct wim_lookup_table_entry *lte, + u64 size, + consume_data_callback_t cb, + void *ctx_or_buf, + 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. + * + * Feed the data either to a callback function (cb != NULL, passing it + * ctx_or_buf), or write it directly into a buffer (cb == NULL, ctx_or_buf + * specifies the buffer, which must have room for @size bytes). * - * @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. + * 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 set as documented in + * read_partial_wim_resource(). Otherwise @flags are ignored. */ -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 +read_resource_prefix(const struct wim_lookup_table_entry *lte, + u64 size, consume_data_callback_t cb, void *ctx_or_buf, + int flags) { - 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; + static const read_resource_prefix_handler_t handlers[] = { + [RESOURCE_IN_WIM] = read_wim_resource_prefix, + #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, + #ifdef WITH_FUSE + [RESOURCE_IN_STAGING_FILE] = read_file_on_disk_prefix, + #endif + #ifdef WITH_NTFS_3G + [RESOURCE_IN_NTFS_VOLUME] = read_ntfs_file_prefix, + #endif + #ifdef __WIN32__ + [RESOURCE_WIN32_ENCRYPTED] = read_win32_encrypted_file_prefix, + #endif + }; + wimlib_assert(lte->resource_location < ARRAY_LEN(handlers) + && handlers[lte->resource_location] != NULL); + return handlers[lte->resource_location](lte, size, cb, ctx_or_buf, flags); } -int write_resource_from_memory(const u8 resource[], int out_ctype, - u64 resource_original_size, FILE *out_fp, - u64 *resource_size_ret) +int +read_full_resource_into_buf(const struct wim_lookup_table_entry *lte, + void *buf) { - 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); - } + return read_resource_prefix(lte, wim_resource_size(lte), NULL, buf, 0); } - -/* - * 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 +read_full_resource_into_alloc_buf(const struct wim_lookup_table_entry *lte, + void **buf_ret) { int ret; + void *buf; - /* 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; + 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; } - 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; - } + 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; } - 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; + *buf_ret = buf; 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) +int +res_entry_to_data(const struct resource_entry *res_entry, + WIMStruct *wim, void **buf_ret) { - u8 *buf; - int ctype; - u32 dentry_offset; int ret; - const struct resource_entry *res_entry; - struct dentry *dentry; - struct wim_security_data *sd; + struct wim_lookup_table_entry *lte; - res_entry = &imd->metadata_lte->resource_entry; + lte = new_lookup_table_entry(); + if (!lte) + return WIMLIB_ERR_NOMEM; - DEBUG("Reading metadata resource: length = %"PRIu64", " - "offset = %"PRIu64"", - res_entry->original_size, res_entry->offset); + copy_resource_entry(<e->resource_entry, res_entry); + lte->unhashed = 1; + lte->part_number = wim->hdr.part_number; + lte_init_wim(lte, wim); - 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); + ret = read_full_resource_into_alloc_buf(lte, buf_ret); + free_lookup_table_entry(lte); + return ret; +} - if (!buf) { - ERROR("Failed to allocate %"PRIu64" bytes for uncompressed " - "metadata resource", res_entry->original_size); - return WIMLIB_ERR_NOMEM; - } +struct extract_ctx { + SHA_CTX sha_ctx; + consume_data_callback_t extract_chunk; + void *extract_chunk_arg; +}; - /* 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. */ - - /* 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; - - 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; - } +static int +extract_chunk_sha1_wrapper(const void *chunk, size_t chunk_size, + void *_ctx) +{ + struct extract_ctx *ctx = _ctx; - 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; - - imd->security_data = sd; - imd->root_dentry = dentry; - goto out_free_buf; -out_free_security_data: - free_security_data(sd); -out_free_dentry_tree: - free_dentry_tree(dentry, NULL, false); -out_free_buf: - FREE(buf); - return ret; + sha1_update(&ctx->sha_ctx, chunk, chunk_size); + return ctx->extract_chunk(chunk, chunk_size, ctx->extract_chunk_arg); } -/* Write the metadata resource for the current image. */ -int write_metadata_resource(WIMStruct *w) +/* Extracts the first @size bytes of a WIM resource to somewhere. In the + * process, the SHA1 message digest of the resource is checked if the full + * resource is being extracted. + * + * @extract_chunk is a function that is called to extract each chunk of the + * resource. */ +int +extract_wim_resource(const struct wim_lookup_table_entry *lte, + u64 size, + consume_data_callback_t extract_chunk, + void *extract_chunk_arg) { - 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; - - struct wim_security_data *sd = wim_security_data(w); - if (sd) - subdir_offset = sd->total_length + root->length + 8; - else - 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; + if (size == wim_resource_size(lte)) { + /* Do SHA1 */ + struct extract_ctx ctx; + ctx.extract_chunk = extract_chunk; + ctx.extract_chunk_arg = extract_chunk_arg; + sha1_init(&ctx.sha_ctx); + ret = read_resource_prefix(lte, size, + extract_chunk_sha1_wrapper, + &ctx, 0); + if (ret == 0) { + u8 hash[SHA1_HASH_SIZE]; + sha1_final(hash, &ctx.sha_ctx); + if (!hashes_equal(hash, lte->hash)) { + 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; + } + } + } else { + /* Don't do SHA1 */ + ret = read_resource_prefix(lte, size, extract_chunk, + extract_chunk_arg, 0); } + return ret; +} - p = write_security_data(sd, buf); - - DEBUG("Writing dentry tree."); - p = write_dentry_tree(root, p); +static int +extract_wim_chunk_to_fd(const void *buf, size_t len, void *_fd_p) +{ + struct filedes *fd = _fd_p; + int ret = full_write(fd, buf, len); + if (ret) + ERROR_WITH_ERRNO("Error writing to file descriptor"); + return ret; +} - /* 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); +int +extract_wim_resource_to_fd(const struct wim_lookup_table_entry *lte, + struct filedes *fd, u64 size) +{ + return extract_wim_resource(lte, size, extract_wim_chunk_to_fd, fd); +} - 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; +static int +sha1_chunk(const void *buf, size_t len, void *ctx) +{ + sha1_update(ctx, buf, len); return 0; } -static int write_file_resource(WIMStruct *w, const u8 hash[]) +/* Calculate the SHA1 message digest of a stream. */ +int +sha1_resource(struct wim_lookup_table_entry *lte) { - /* Get the lookup entry for the file resource. */ - struct lookup_table_entry *lte; - - lte = lookup_resource(w->lookup_table, hash); - 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; - - /* do not write empty resources */ - if (lte->resource_entry.original_size == 0) - return 0; - - int out_wim_ctype = wimlib_get_compression_type(w); - struct resource_entry *output_res_entry = <e->output_resource_entry; - u64 len; - FILE *in_fp; - FILE *out_fp = w->out_fp; - int ret = 0; - - /* Figure out if we can read the resource from the WIM file, or - * if we have to read it from the filesystem outside, or if it's a - * symbolic link with the data already in memory pointed to by a field - * of the lookup table entry. */ - if (lte->is_symlink) { - off_t offset = ftello(w->out_fp); - u64 new_size; - - if (offset == -1) { - ERROR_WITH_ERRNO("Could not get position in output " - "file"); - return WIMLIB_ERR_WRITE; - } - - wimlib_assert(lte->symlink_buf); - - len = lte->resource_entry.original_size; - - recompress_resource(in_fp, lte->symlink_buf, len, len, 0, - 0, out_fp, out_wim_ctype, &new_size); - output_res_entry->size = new_size; - output_res_entry->original_size = len; - output_res_entry->offset = offset; - output_res_entry->flags = (out_wim_ctype == WIM_COMPRESSION_TYPE_NONE) - ? 0 : WIM_RESHDR_FLAG_COMPRESSED; - } else 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; - } - - 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 { - int in_wim_ctype; - - /* Read from input WIM (possibly compressed) */ + int ret; + SHA_CTX sha_ctx; - /* 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); - } + sha1_init(&sha_ctx); + ret = read_resource_prefix(lte, wim_resource_size(lte), + sha1_chunk, &sha_ctx, 0); + if (ret == 0) + sha1_final(lte->hash, &sha_ctx); return ret; } -/* - * Writes a dentry's resources 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, and the alternate data streams. - * - * @return zero on success, nonzero on failure. - */ -int write_dentry_resources(struct dentry *dentry, void *wim_p) +/* 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_p; - int ret; - - /* Directories don't need file resources. */ - if (dentry_is_directory(dentry)) - return 0; - - ret = write_file_resource(w, dentry->hash); - if (ret != 0) - return ret; - for (u16 i = 0; i < dentry->num_ads; i++) { - ret = write_file_resource(w, dentry->ads_entries[i].hash); - if (ret != 0) - return 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.) */ + + /* 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; + } + if (entry->original_size & 0xc000000000000000ULL) { + WARNING("Truncating original_size in resource entry"); + entry->original_size &= 0x3fffffffffffffffULL; } - 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) +{ + /* 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); +}