X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Fresource.c;h=001ea02431daf72f36d1ddedad32a8a5d50a24de;hb=84aa21bf2722d14eff30fac2ec4904ed2ed6de52;hp=c7eedab0ad61663b30ea7f2045c6553945a90be0;hpb=50ae56edcc3938f5183ddfc8910de2df5774eaf6;p=wimlib diff --git a/src/resource.c b/src/resource.c index c7eedab0..001ea024 100644 --- a/src/resource.c +++ b/src/resource.c @@ -22,351 +22,410 @@ * wimlib; if not, see http://www.gnu.org/licenses/. */ -#include "wimlib_internal.h" -#include "dentry.h" -#include "lookup_table.h" -#include "buffer_io.h" -#include "sha1.h" +#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__ -# include "win32.h" +/* for read_win32_file_prefix(), read_win32_encrypted_file_prefix() */ +# include "wimlib/win32.h" #endif -#include -#include -#include -#include -#include +#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 -/* Write @n bytes from @buf to the file descriptor @fd, retrying on internupt - * and on short writes. +/* + * Compressed resources * - * Returns short count and set errno on failure. */ -static ssize_t -full_write(int fd, const void *buf, size_t n) -{ - const void *p = buf; - ssize_t ret; - ssize_t total = 0; - - while (total != n) { - ret = write(fd, p, n); - if (ret < 0) { - if (errno == EINTR) - continue; - else - break; - } - total += ret; - p += ret; - } - return total; -} - -/* Read @n bytes from the file descriptor @fd to the buffer @buf, retrying on - * internupt and on short reads. + * A compressed resource in a WIM consists of a number of consecutive LZX or + * XPRESS-compressed chunks, each of which decompresses to 32768 bytes of data, + * except possibly the last, which always decompresses to any remaining bytes. + * In addition, immediately before the chunks, a table (the "chunk table") + * provides the offset, in bytes relative to the end of the chunk table, of the + * start of each compressed chunk, except for the first chunk which is omitted + * as it always has an offset of 0. Therefore, a compressed resource with N + * chunks will have a chunk table with N - 1 entries. + * + * Additional information: * - * Returns short count and set errno on failure. */ -static size_t -full_read(int fd, void *buf, size_t n) + * - Entries in the chunk table are 4 bytes each, except if the uncompressed + * size of the resource is greater than 4 GiB, in which case the entries in + * the chunk table are 8 bytes each. In either case, the entries are unsigned + * little-endian integers. + * + * - The chunk table is included in the compressed size of the resource provided + * in the corresponding entry in the WIM's stream lookup table. + * + * - The compressed size of a chunk is never greater than the uncompressed size. + * From the compressor's point of view, chunks that would have compressed to a + * size greater than or equal to their original size are in fact stored + * uncompressed. From the decompresser's point of view, chunks with + * compressed size equal to their uncompressed size are in fact uncompressed. + * + * Furthermore, wimlib supports its own "pipable" WIM format, and for this the + * structure of compressed resources was modified to allow piped reading and + * writing. To make sequential writing possible, the chunk table is placed + * after the chunks rather than before the chunks, and to make sequential + * reading possible, each chunk is prefixed with a 4-byte header giving its + * compressed size as a 32-bit, unsigned, little-endian integer (less than or + * equal to 32768). Otherwise the details are the same. + */ + +typedef int (*decompress_func_t)(const void *, unsigned, void *, unsigned); + +static decompress_func_t +get_decompress_func(int ctype) { - size_t bytes_remaining = n; - while (bytes_remaining) { - ssize_t bytes_read = read(fd, buf, bytes_remaining); - if (bytes_read < 0) { - if (errno == EINTR) - continue; - break; - } - bytes_remaining -= bytes_read; - buf += bytes_read; - } - return n - bytes_remaining; + if (ctype == WIMLIB_COMPRESSION_TYPE_LZX) + return wimlib_lzx_decompress; + else + return wimlib_xpress_decompress; } /* - * Reads all or part of a compressed WIM resource. + * 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: * - * Returns zero on success, nonzero on failure. + * 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(FILE *fp, - u64 resource_compressed_size, - u64 resource_uncompressed_size, - u64 resource_offset, - int resource_ctype, - u64 len, - u64 offset, - consume_data_callback_t cb, - void *ctx_or_buf) +read_compressed_resource(const struct wim_lookup_table_entry *lte, + u64 size, consume_data_callback_t cb, + void *ctx_or_buf, int flags, u64 offset) { int ret; - /* Trivial case */ - if (len == 0) + /* 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); + } + + wimlib_assert(offset + size <= wim_resource_size(lte)); + + /* Handle the trivial case. */ + if (size == 0) return 0; - int (*decompress)(const void *, unsigned, void *, unsigned); - /* Set the appropriate decompress function. */ - if (resource_ctype == WIMLIB_COMPRESSION_TYPE_LZX) - decompress = wimlib_lzx_decompress; - else - decompress = wimlib_xpress_decompress; - - /* The structure of a compressed resource consists of a table of chunk - * offsets followed by the chunks themselves. Each chunk consists of - * compressed data, and there is one chunk for each WIM_CHUNK_SIZE = - * 32768 bytes of the uncompressed file, with the last chunk having any - * remaining bytes. - * - * The chunk offsets are measured relative to the end of the chunk - * table. The first chunk is omitted from the table in the WIM file - * because its offset is implicitly given by the fact that it directly - * follows the chunk table and therefore must have an offset of 0. - */ + /* Get the appropriate decompression function. */ + decompress_func_t decompress = + get_decompress_func(wim_resource_compression_type(lte)); - /* Calculate how many chunks the resource consists of in its entirety. - * */ - u64 num_chunks = (resource_uncompressed_size + WIM_CHUNK_SIZE - 1) / - WIM_CHUNK_SIZE; - /* As mentioned, the first chunk has no entry in the chunk table. */ - u64 num_chunk_entries = num_chunks - 1; + /* Get the file descriptor for the WIM. */ + struct filedes *in_fd = <e->wim->in_fd; + + /* Calculate the number of chunks the resource is divided into. */ + u64 num_chunks = wim_resource_chunks(lte); + /* 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; - /* The index of the chunk that the read starts at. */ + /* Calculate the 0-based index of the chunk at which the read starts. + */ 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; + /* 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++; - /* Number of chunks that are actually needed to read the requested part - * of the file. */ - u64 num_needed_chunks = end_chunk - start_chunk + 1; + /* 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; - /* 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++; + /* Calculate the size, in bytes, of the full chunk table. */ + u64 chunk_table_size = num_chunk_entries * chunk_entry_size; - /* Allocate the chunk table. It will only contain offsets for the - * chunks that are actually needed for this read. */ + /* Allocate a buffer to hold a subset of the chunk table. It will only + * contain offsets for the chunks that are actually needed for this + * read. For speed, allocate the buffer on the stack unless it's too + * large. */ u64 *chunk_offsets; bool chunk_offsets_malloced; - if (num_needed_chunks < 1000) { - chunk_offsets = alloca(num_needed_chunks * sizeof(u64)); + if (num_alloc_chunk_entries < 1024) { + chunk_offsets = alloca(num_alloc_chunk_entries * sizeof(u64)); chunk_offsets_malloced = false; } else { - chunk_offsets = malloc(num_needed_chunks * sizeof(u64)); + chunk_offsets = malloc(num_alloc_chunk_entries * sizeof(u64)); if (!chunk_offsets) { ERROR("Failed to allocate chunk table " - "with %"PRIu64" entries", num_needed_chunks); + "with %"PRIu64" entries", num_alloc_chunk_entries); return WIMLIB_ERR_NOMEM; } chunk_offsets_malloced = true; } - /* Set the implicit offset of the first chunk if it is included in the - * needed chunks. - * - * Note: M$'s documentation includes a picture that shows the first - * chunk starting right after the chunk entry table, labeled as offset - * 0x10. However, in the actual file format, the offset is measured - * from the end of the chunk entry table, so the first chunk has an - * offset of 0. */ + /* Set the implicit offset of the first chunk if it's included in the + * needed chunks. */ if (start_chunk == 0) chunk_offsets[0] = 0; - /* According to M$'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. */ + /* Calculate the index of the first needed entry in the chunk table. */ u64 start_table_idx = (start_chunk == 0) ? 0 : start_chunk - 1; - /* Number of entries we need to actually read from the chunk - * table (excludes the implicit first chunk). */ + /* Calculate the number of entries that need to be read from the chunk + * table. */ u64 num_needed_chunk_entries = (start_chunk == 0) ? - num_needed_chunks - 1 : num_needed_chunks; - - /* Skip over unneeded chunk table entries. */ - u64 file_offset_of_needed_chunk_entries = resource_offset + - start_table_idx * chunk_entry_size; - if (fseeko(fp, file_offset_of_needed_chunk_entries, SEEK_SET)) - goto read_error; - - /* Number of bytes we need to read from the chunk table. */ - size_t size = num_needed_chunk_entries * chunk_entry_size; - - /* Read the raw data into the end of the chunk_offsets array to - * avoid allocating another array. */ - void *chunk_tab_buf = (void*)&chunk_offsets[num_needed_chunks] - size; + num_alloc_chunk_entries - 1 : num_alloc_chunk_entries; + + /* Calculate the number of bytes of data that need to be read from the + * chunk table. */ + size_t chunk_table_needed_size = + num_needed_chunk_entries * chunk_entry_size; + if ((u64)chunk_table_needed_size != + num_needed_chunk_entries * chunk_entry_size) + { + ERROR("Compressed read request too large to fit into memory!"); + ret = WIMLIB_ERR_NOMEM; + goto out_free_chunk_offsets; + } - if (fread(chunk_tab_buf, 1, size, fp) != size) + /* Calculate the byte offset, in the WIM file, of the first chunk table + * entry to read. Take into account that if the WIM file is in the + * special "pipable" format, then the chunk table is at the end of the + * resource, not the beginning. */ + u64 file_offset_of_needed_chunk_entries = + lte->resource_entry.offset + (start_table_idx * + chunk_entry_size); + if (lte->is_pipable) + file_offset_of_needed_chunk_entries += lte->resource_entry.size - + chunk_table_size; + + /* Read the needed chunk table entries into the end of the chunk_offsets + * buffer. */ + void *chunk_tab_data = (u8*)&chunk_offsets[num_alloc_chunk_entries] - + chunk_table_needed_size; + ret = full_pread(in_fd, chunk_tab_data, chunk_table_needed_size, + file_offset_of_needed_chunk_entries); + if (ret) goto read_error; /* Now fill in chunk_offsets from the entries we have read in - * chunk_tab_buf. */ - - u64 *chunk_tab_p = chunk_offsets; - if (start_chunk == 0) - chunk_tab_p++; - - if (chunk_entry_size == 4) { - u32 *entries = (u32*)chunk_tab_buf; - while (num_needed_chunk_entries--) - *chunk_tab_p++ = le32_to_cpu(*entries++); - } else { - u64 *entries = (u64*)chunk_tab_buf; - while (num_needed_chunk_entries--) - *chunk_tab_p++ = le64_to_cpu(*entries++); + * chunk_tab_data. Careful: chunk_offsets aliases chunk_tab_data, which + * breaks C's aliasing rules when we read 32-bit integers and store + * 64-bit integers. But since the operations are safe as long as the + * compiler doesn't mess with their order, we use the gcc may_alias + * extension to tell the compiler that loads from the 32-bit integers + * may alias stores to the 64-bit integers. */ + { + typedef le64 __attribute__((may_alias)) aliased_le64_t; + typedef le32 __attribute__((may_alias)) aliased_le32_t; + u64 *chunk_offsets_p = chunk_offsets; + u64 i; + + if (start_chunk == 0) + chunk_offsets_p++; + + if (chunk_entry_size == 4) { + aliased_le32_t *raw_entries = (aliased_le32_t*)chunk_tab_data; + for (i = 0; i < num_needed_chunk_entries; i++) + chunk_offsets_p[i] = le32_to_cpu(raw_entries[i]); + } else { + aliased_le64_t *raw_entries = (aliased_le64_t*)chunk_tab_data; + for (i = 0; i < num_needed_chunk_entries; i++) + chunk_offsets_p[i] = le64_to_cpu(raw_entries[i]); + } } - /* Done 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)) - goto read_error; + /* Calculate file offset of the first chunk that needs to be read. N.B. + * if the resource is pipable, the entries in the chunk table do *not* + * include the chunk headers. */ + u64 cur_read_offset = lte->resource_entry.offset + chunk_offsets[0]; + if (!lte->is_pipable) + cur_read_offset += chunk_table_size; + else + cur_read_offset += start_chunk * + sizeof(struct pwm_chunk_hdr); - /* Pointer to current position in the output buffer for uncompressed - * data. Alternatively, if using a callback function, we repeatedly - * fill a temporary buffer to feed data into the callback function. */ + /* If using a callback function, allocate a temporary buffer that will + * be used to pass data to it. If writing directly to a buffer instead, + * arrange to write data directly into it. */ u8 *out_p; if (cb) out_p = alloca(WIM_CHUNK_SIZE); else out_p = ctx_or_buf; - /* Buffer for compressed data. While most compressed chunks will have a - * size much less than WIM_CHUNK_SIZE, WIM_CHUNK_SIZE - 1 is the maximum - * size in the worst-case. This assumption is valid only if chunks that - * happen to compress to more than the uncompressed size (i.e. a - * sequence of random bytes) are always stored uncompressed. But this seems - * to be the case in M$'s WIM files, even though it is undocumented. */ - void *compressed_buf = alloca(WIM_CHUNK_SIZE - 1); - - /* Decompress all the chunks. */ + /* Unless the raw compressed data was requested, allocate a temporary + * buffer for reading compressed chunks, each of which can be at most + * WIM_CHUNK_SIZE - 1 bytes. This excludes compressed chunks that are a + * full WIM_CHUNK_SIZE bytes, which are handled separately. */ + void *compressed_buf; + if (!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS)) + compressed_buf = alloca(WIM_CHUNK_SIZE - 1); + + /* Read, and possibly decompress, each needed chunk, either writing the + * data directly into the @ctx_or_buf buffer or passing it to the @cb + * callback function. */ for (u64 i = start_chunk; i <= end_chunk; i++) { + /* If the resource is pipable, skip the chunk header. */ + if (lte->is_pipable) + cur_read_offset += sizeof(struct pwm_chunk_hdr); + /* Calculate the sizes of the compressed chunk and of the - * uncompressed chunk. */ + * uncompressed chunk. */ unsigned compressed_chunk_size; unsigned uncompressed_chunk_size; if (i != num_chunks - 1) { - /* All the chunks except the last one in the resource - * expand to WIM_CHUNK_SIZE uncompressed, and the amount - * of compressed data for the chunk is given by the - * difference of offsets in the chunk offset table. */ + /* Not the last chunk. Compressed size is given by + * difference of chunk table entries; uncompressed size + * is always 32768 bytes. */ compressed_chunk_size = chunk_offsets[i + 1 - start_chunk] - chunk_offsets[i - start_chunk]; uncompressed_chunk_size = WIM_CHUNK_SIZE; } else { - /* The last compressed chunk consists of the remaining - * bytes in the file resource, and the last uncompressed - * chunk has size equal to however many bytes are left- - * that is, the remainder of the uncompressed size when - * divided by WIM_CHUNK_SIZE. - * - * Note that the resource_compressed_size includes the - * chunk table, so the size of it must be subtracted. */ - compressed_chunk_size = resource_compressed_size - + /* Last chunk. Compressed size is the remaining size in + * the compressed resource; uncompressed size is the + * remaining size in the uncompressed resource. */ + compressed_chunk_size = lte->resource_entry.size - chunk_table_size - chunk_offsets[i - start_chunk]; + if (lte->is_pipable) + compressed_chunk_size -= num_chunks * + sizeof(struct pwm_chunk_hdr); - uncompressed_chunk_size = resource_uncompressed_size % - WIM_CHUNK_SIZE; - - /* If the remainder is 0, the last chunk actually - * uncompresses to a full WIM_CHUNK_SIZE bytes. */ - if (uncompressed_chunk_size == 0) + if (wim_resource_size(lte) % WIM_CHUNK_SIZE == 0) uncompressed_chunk_size = WIM_CHUNK_SIZE; + else + uncompressed_chunk_size = wim_resource_size(lte) % + WIM_CHUNK_SIZE; } - /* Figure out how much of this chunk we actually need to read */ - u64 start_offset; - if (i == start_chunk) - start_offset = start_chunk_offset; - else - start_offset = 0; - u64 end_offset; - if (i == end_chunk) - end_offset = end_chunk_offset; - else - end_offset = WIM_CHUNK_SIZE - 1; - - unsigned partial_chunk_size = end_offset + 1 - start_offset; - bool is_partial_chunk = (partial_chunk_size != uncompressed_chunk_size); - - /* This is undocumented, but chunks can be uncompressed. This - * appears to always be the case when the compressed chunk size - * is equal to the uncompressed chunk size. */ - if (compressed_chunk_size == uncompressed_chunk_size) { - /* Uncompressed chunk */ - if (start_offset != 0) - if (fseeko(fp, start_offset, SEEK_CUR)) - goto read_error; - if (fread(cb ? out_p + start_offset : out_p, - 1, partial_chunk_size, fp) != partial_chunk_size) + /* Calculate how much of this chunk needs to be read. */ + + unsigned partial_chunk_size; + u64 start_offset = 0; + u64 end_offset = WIM_CHUNK_SIZE - 1; + + if (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS) { + partial_chunk_size = compressed_chunk_size; + } else { + if (i == start_chunk) + start_offset = start_offset_in_chunk; + + if (i == end_chunk) + end_offset = end_offset_in_chunk; + + partial_chunk_size = end_offset + 1 - start_offset; + } + + if (compressed_chunk_size == uncompressed_chunk_size || + (flags & WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS)) + { + /* Chunk stored uncompressed, or reading raw chunk data. */ + ret = full_pread(in_fd, + cb ? out_p + start_offset : out_p, + partial_chunk_size, + cur_read_offset + start_offset); + if (ret) goto read_error; } else { - /* Compressed chunk */ + /* Compressed chunk and not doing raw read. */ - /* Read the compressed data into compressed_buf. */ - if (fread(compressed_buf, 1, compressed_chunk_size, - fp) != compressed_chunk_size) + /* Read the compressed data into compressed_buf. */ + ret = full_pread(in_fd, + compressed_buf, + compressed_chunk_size, + cur_read_offset); + if (ret) goto read_error; /* For partial chunks and when writing directly to a * buffer, we must buffer the uncompressed data because - * we don't need all of it. */ - if (is_partial_chunk && !cb) { + * we don't need all of it. */ + if (partial_chunk_size != uncompressed_chunk_size && + cb == NULL) + { u8 uncompressed_buf[uncompressed_chunk_size]; - ret = decompress(compressed_buf, - compressed_chunk_size, - uncompressed_buf, - uncompressed_chunk_size); + ret = (*decompress)(compressed_buf, + compressed_chunk_size, + uncompressed_buf, + uncompressed_chunk_size); if (ret) { + ERROR("Failed to decompress data."); ret = WIMLIB_ERR_DECOMPRESSION; - goto out; + errno = EINVAL; + goto out_free_chunk_offsets; } memcpy(out_p, uncompressed_buf + start_offset, partial_chunk_size); } else { - ret = decompress(compressed_buf, - compressed_chunk_size, - out_p, - uncompressed_chunk_size); + ret = (*decompress)(compressed_buf, + compressed_chunk_size, + out_p, + uncompressed_chunk_size); if (ret) { + ERROR("Failed to decompress data."); ret = WIMLIB_ERR_DECOMPRESSION; - goto out; + errno = EINVAL; + goto out_free_chunk_offsets; } } } if (cb) { - /* Feed the data to the callback function */ + /* Feed the data to the callback function. */ ret = cb(out_p + start_offset, partial_chunk_size, ctx_or_buf); if (ret) - goto out; + goto out_free_chunk_offsets; } else { /* No callback function provided; we are writing * directly to a buffer. Advance the pointer into this @@ -374,249 +433,296 @@ read_compressed_resource(FILE *fp, * written. */ out_p += partial_chunk_size; } + cur_read_offset += compressed_chunk_size; } ret = 0; -out: +out_free_chunk_offsets: if (chunk_offsets_malloced) FREE(chunk_offsets); return ret; read_error: - if (feof(fp)) - ERROR("Unexpected EOF in compressed file resource"); - else - ERROR_WITH_ERRNO("Error reading compressed file resource"); - ret = WIMLIB_ERR_READ; - goto out; + 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, void *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 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 void * -get_resource_entry(const void *p, struct resource_entry *entry) +/* Read and decompress data from a compressed, pipable resource being read from + * a pipe. */ +static int +read_pipable_resource(const struct wim_lookup_table_entry *lte, + u64 size, consume_data_callback_t cb, + void *ctx_or_buf, int flags, u64 offset) { - u64 size; - u8 flags; + 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; - p = get_u56(p, &size); - p = get_u8(p, &flags); - entry->size = size; - entry->flags = flags; + cchunk_size = le32_to_cpu(chunk_hdr.compressed_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... */ - p = get_u64(p, &entry->offset); - if (entry->offset & 0xc000000000000000ULL) { - WARNING("Truncating offset in resource entry"); - entry->offset &= 0x3fffffffffffffffULL; - } - p = get_u64(p, &entry->original_size); - if (entry->original_size & 0xc000000000000000ULL) { - WARNING("Truncating original_size in resource entry"); - entry->original_size &= 0x3fffffffffffffffULL; - } - return p; -} + if (cchunk_size > WIM_CHUNK_SIZE) { + errno = EINVAL; + ret = WIMLIB_ERR_INVALID_PIPABLE_WIM; + goto invalid; + } -/* 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. */ -void * -put_resource_entry(void *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; -} + /* Read chunk data. */ + ret = full_read(in_fd, cchunk, cchunk_size); + if (ret) + goto read_error; -static FILE * -wim_get_fp(WIMStruct *w) -{ - FILE *fp; -#if defined(WITH_FUSE) || defined(ENABLE_MULTITHREADED_COMPRESSION) - pthread_mutex_lock(&w->fp_tab_mutex); + if (flags & WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY) + continue; - wimlib_assert(w->filename != NULL); + /* 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; + } - for (size_t i = 0; i < w->num_allocated_fps; i++) { - if (w->fp_tab[i]) { - fp = w->fp_tab[i]; - w->fp_tab[i] = NULL; - goto out_unlock; + /* 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); } } - DEBUG("Opening extra file descriptor to `%"TS"'", w->filename); - fp = tfopen(w->filename, T("rb")); - if (!fp) - ERROR_WITH_ERRNO("Failed to open `%"TS"'", w->filename); -out_unlock: - pthread_mutex_unlock(&w->fp_tab_mutex); -#else /* WITH_FUSE || ENABLE_MULTITHREADED_COMPRESSION */ - fp = w->fp; -#endif /* !WITH_FUSE && !ENABLE_MULTITHREADED_COMPRESSION */ - return fp; -} - -static int -wim_release_fp(WIMStruct *w, FILE *fp) -{ - int ret = 0; -#if defined(WITH_FUSE) || defined(ENABLE_MULTITHREADED_COMPRESSION) - FILE **fp_tab; - pthread_mutex_lock(&w->fp_tab_mutex); + ret = skip_chunk_table(lte, in_fd); + if (ret) + goto read_error; + return 0; - for (size_t i = 0; i < w->num_allocated_fps; i++) { - if (w->fp_tab[i] == NULL) { - w->fp_tab[i] = fp; - goto out_unlock; - } - } +read_error: + ERROR_WITH_ERRNO("Error reading compressed file resource"); + return ret; - fp_tab = REALLOC(w->fp_tab, sizeof(FILE*) * (w->num_allocated_fps + 4)); - if (!fp_tab) { - ret = WIMLIB_ERR_NOMEM; - fclose(fp); - goto out_unlock; - } - w->fp_tab = fp_tab; - memset(&w->fp_tab[w->num_allocated_fps], 0, 4 * sizeof(FILE*)); - w->fp_tab[w->num_allocated_fps] = fp; - w->num_allocated_fps += 4; -out_unlock: - pthread_mutex_unlock(&w->fp_tab_mutex); -#endif /* WITH_FUSE || ENABLE_MULTITHREADED_COMPRESSION */ +invalid: + ERROR("Compressed file resource is invalid"); return ret; } -static int +/* + * read_partial_wim_resource()- + * + * Read a range of data from a uncompressed or compressed resource in a WIM + * file. Data is written into a buffer or fed into a callback function, as + * documented in read_resource_prefix(). + * + * @flags can be: + * + * 0: + * Just do a normal read, decompressing the data if necessary. @size and + * @offset are interpreted relative to the uncompressed contents of the + * stream. + * + * WIMLIB_READ_RESOURCE_FLAG_RAW_FULL: + * Only valid when the resource is compressed: Read the raw contents of + * the compressed resource. If the resource is non-pipable, this includes + * the chunk table as well as the compressed chunks. If the resource is + * pipable, this includes the compressed chunks--- including the chunk + * headers--- and the chunk table. The stream header is still *not* + * included. + * + * In this mode, @offset is relative to the beginning of the raw contents + * of the compressed resource--- that is, the chunk table if the resource + * is non-pipable, or the header for the first compressed chunk if the + * resource is pipable. @size is the number of raw bytes to read, which + * must not overrun the end of the resource. For example, if @offset is 0, + * then @size can be at most the raw size of the compressed resource + * (@lte->resource_entry.size). + * + * WIMLIB_READ_RESOURCE_FLAG_RAW_CHUNKS: + * Only valid when the resource is compressed and is not being read from a + * pipe: Read the raw contents of the compressed chunks of the compressed + * resource. For pipable resources, this does *not* include the chunk + * headers. If a callback function is being used, it will be called once + * for each compressed chunk. The chunk table is excluded. Also, for + * pipable resources, the stream and chunk headers are excluded. In this + * mode, @size must be exactly the raw size of the compressed resource + * (@lte->resource_entry.size) and @offset must be 0. + * + * WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY: + * Only valid when the resource is being read from a pipe: Skip over the + * requested data rather than feed it to the callback function or write it + * into the buffer. No decompression is done. + * WIMLIB_READ_RESOURCE_FLAG_RAW_* may not be combined with this flag. + * @offset must be 0 and @size must be the uncompressed size of the + * resource. + * + * Return values: + * WIMLIB_ERR_SUCCESS (0) + * WIMLIB_ERR_READ (errno set) + * WIMLIB_ERR_UNEXPECTED_END_OF_FILE (errno set to 0) + * WIMLIB_ERR_NOMEM (errno set to ENOMEM) + * WIMLIB_ERR_DECOMPRESSION (errno set to EINVAL) + * WIMLIB_ERR_INVALID_PIPABLE_WIM (errno set to EINVAL) + * + * or other error code returned by the @cb function. + */ +int read_partial_wim_resource(const struct wim_lookup_table_entry *lte, - u64 size, - consume_data_callback_t cb, - void *ctx_or_buf, - int flags, - u64 offset) + u64 size, consume_data_callback_t cb, + void *ctx_or_buf, int flags, u64 offset) { - FILE *wim_fp; - WIMStruct *wim; + struct filedes *in_fd; int ret; + /* Make sure the resource is actually located in a WIM file and is not + * somewhere else. */ wimlib_assert(lte->resource_location == RESOURCE_IN_WIM); - wim = lte->wim; - if (flags & WIMLIB_RESOURCE_FLAG_THREADSAFE_READ) { - wim_fp = wim_get_fp(wim); - if (!wim_fp) { - ret = WIMLIB_ERR_READ; - goto out; - } - } else { - wim_fp = lte->wim->fp; - } - - if (lte->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED && - !(flags & WIMLIB_RESOURCE_FLAG_RAW)) + /* Retrieve input file descriptor for the WIM file. */ + in_fd = <e->wim->in_fd; + + /* Don't allow raw reads (either full or chunks) of uncompressed + * resources. */ + wimlib_assert(!(flags & WIMLIB_READ_RESOURCE_FLAG_RAW) || + resource_is_compressed(<e->resource_entry)); + + /* Don't allow seek-only reads unless reading from a pipe; also don't + * allow combining SEEK_ONLY with either RAW flag. */ + wimlib_assert(!(flags & WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY) || + (!filedes_is_seekable(in_fd) && + !(flags & WIMLIB_READ_RESOURCE_FLAG_RAW))); + + DEBUG("Reading WIM resource: %"PRIu64" @ +%"PRIu64" " + "from %"PRIu64" @ +%"PRIu64" (readflags 0x%08x, resflags 0x%02x%s)", + size, offset, + lte->resource_entry.original_size, lte->resource_entry.offset, + flags, lte->resource_entry.flags, + (lte->is_pipable ? ", pipable" : "")); + + if ((flags & WIMLIB_READ_RESOURCE_FLAG_RAW_FULL) || + !resource_is_compressed(<e->resource_entry)) { - ret = read_compressed_resource(wim_fp, - lte->resource_entry.size, - lte->resource_entry.original_size, - lte->resource_entry.offset, - wimlib_get_compression_type(wim), - size, - offset, - cb, - ctx_or_buf); - } else { + /* Reading raw resource contents or reading uncompressed + * resource. */ + wimlib_assert(offset + size <= lte->resource_entry.size); offset += lte->resource_entry.offset; - - if (fseeko(wim_fp, offset, SEEK_SET)) { - ERROR_WITH_ERRNO("Failed to seek to offset %"PRIu64 - " in WIM", offset); - ret = WIMLIB_ERR_READ; - goto out_release_fp; - } - if (cb) { + if (flags & WIMLIB_READ_RESOURCE_FLAG_SEEK_ONLY) { + if (lte->resource_entry.size != 0) { + u8 dummy; + ret = full_pread(in_fd, &dummy, 1, + offset + lte->resource_entry.size - 1); + if (ret) + goto read_error; + } + } else if (cb) { /* Send data to callback function */ u8 buf[min(WIM_CHUNK_SIZE, size)]; while (size) { - size_t bytes_to_read = min(WIM_CHUNK_SIZE, size); - size_t bytes_read = fread(buf, 1, bytes_to_read, wim_fp); - - if (bytes_read != bytes_to_read) + size_t bytes_to_read = min(WIM_CHUNK_SIZE, + size); + ret = full_pread(in_fd, buf, bytes_to_read, + offset); + if (ret) goto read_error; - ret = cb(buf, bytes_read, ctx_or_buf); + ret = cb(buf, bytes_to_read, ctx_or_buf); if (ret) - goto out_release_fp; - size -= bytes_read; + goto out; + size -= bytes_to_read; + offset += bytes_to_read; } } else { /* Send data directly to a buffer */ - if (fread(ctx_or_buf, 1, size, wim_fp) != size) + ret = full_pread(in_fd, ctx_or_buf, size, offset); + if (ret) goto read_error; } ret = 0; + } else if (lte->is_pipable && !filedes_is_seekable(in_fd)) { + /* Reading compressed, pipable resource from pipe. */ + ret = read_pipable_resource(lte, size, cb, + ctx_or_buf, flags, offset); + } else { + /* Reading compressed, possibly pipable resource from seekable + * file. */ + ret = read_compressed_resource(lte, size, cb, + ctx_or_buf, flags, offset); } - goto out_release_fp; + goto out; + read_error: - if (ferror(wim_fp)) - ERROR_WITH_ERRNO("Error reading data from WIM"); - else - ERROR("Unexpected EOF in WIM!"); - ret = WIMLIB_ERR_READ; -out_release_fp: - if (flags & WIMLIB_RESOURCE_FLAG_THREADSAFE_READ) { - int ret2 = wim_release_fp(wim, wim_fp); - if (ret == 0) - ret = ret2; - } + ERROR_WITH_ERRNO("Error reading data from WIM"); out: - if (ret) { - if (errno == 0) - errno = EIO; - } return ret; } int read_partial_wim_resource_into_buf(const struct wim_lookup_table_entry *lte, - size_t size, u64 offset, void *buf, - bool threadsafe) + size_t size, u64 offset, void *buf) { - return read_partial_wim_resource(lte, size, NULL, buf, - threadsafe ? WIMLIB_RESOURCE_FLAG_THREADSAFE_READ : 0, - offset); + return read_partial_wim_resource(lte, size, NULL, buf, 0, offset); } static int @@ -640,41 +746,45 @@ read_file_on_disk_prefix(const struct wim_lookup_table_entry *lte, { const tchar *filename = lte->file_on_disk; int ret; - int fd; - size_t bytes_read; + struct filedes fd; + int raw_fd; + + DEBUG("Reading %"PRIu64" bytes from \"%"TS"\"", + size, lte->file_on_disk); - fd = open(filename, O_RDONLY); - if (fd < 0) { + raw_fd = open(filename, O_RDONLY); + if (raw_fd < 0) { ERROR_WITH_ERRNO("Can't open \"%"TS"\"", filename); return WIMLIB_ERR_OPEN; } + filedes_init(&fd, raw_fd); if (cb) { /* Send data to callback function */ u8 buf[min(WIM_CHUNK_SIZE, size)]; size_t bytes_to_read; while (size) { bytes_to_read = min(WIM_CHUNK_SIZE, size); - bytes_read = full_read(fd, buf, bytes_to_read); - if (bytes_read != bytes_to_read) + ret = full_read(&fd, buf, bytes_to_read); + if (ret) goto read_error; - ret = cb(buf, bytes_read, ctx_or_buf); + ret = cb(buf, bytes_to_read, ctx_or_buf); if (ret) goto out_close; - size -= bytes_read; + size -= bytes_to_read; } } else { /* Send data directly to a buffer */ - bytes_read = full_read(fd, ctx_or_buf, size); - if (bytes_read != size) + ret = full_read(&fd, ctx_or_buf, size); + if (ret) goto read_error; } ret = 0; goto out_close; + read_error: ERROR_WITH_ERRNO("Error reading \"%"TS"\"", filename); - ret = WIMLIB_ERR_READ; out_close: - close(fd); + filedes_close(&fd); return ret; } #endif /* !__WIN32__ */ @@ -709,6 +819,8 @@ typedef int (*read_resource_prefix_handler_t)(const struct wim_lookup_table_entr 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. @@ -720,12 +832,8 @@ typedef int (*read_resource_prefix_handler_t)(const struct wim_lookup_table_entr * When using a callback function, it is called with chunks up to 32768 bytes in * size until the resource is exhausted. * - * If the resource is located in a WIM file, @flags can be: - * * WIMLIB_RESOURCE_FLAG_THREADSAFE_READ if it must be safe to access the resource - * concurrently by multiple threads. - * * WIMLIB_RESOURCE_FLAG_RAW if the raw compressed data is to be supplied - * instead of the uncompressed data. - * Otherwise, the @flags are ignored. + * If the resource is located in a WIM file, @flags can be set as documented in + * read_partial_wim_resource(). Otherwise @flags are ignored. */ int read_resource_prefix(const struct wim_lookup_table_entry *lte, @@ -734,7 +842,9 @@ read_resource_prefix(const struct wim_lookup_table_entry *lte, { static const read_resource_prefix_handler_t handlers[] = { [RESOURCE_IN_WIM] = read_wim_resource_prefix, - #ifndef __WIN32__ + #ifdef __WIN32__ + [RESOURCE_IN_FILE_ON_DISK] = read_win32_file_prefix, + #else [RESOURCE_IN_FILE_ON_DISK] = read_file_on_disk_prefix, #endif [RESOURCE_IN_ATTACHED_BUFFER] = read_buffer_prefix, @@ -745,7 +855,6 @@ read_resource_prefix(const struct wim_lookup_table_entry *lte, [RESOURCE_IN_NTFS_VOLUME] = read_ntfs_file_prefix, #endif #ifdef __WIN32__ - [RESOURCE_WIN32] = read_win32_file_prefix, [RESOURCE_WIN32_ENCRYPTED] = read_win32_encrypted_file_prefix, #endif }; @@ -756,12 +865,59 @@ read_resource_prefix(const struct wim_lookup_table_entry *lte, int read_full_resource_into_buf(const struct wim_lookup_table_entry *lte, - void *buf, bool thread_safe) + void *buf) +{ + return read_resource_prefix(lte, wim_resource_size(lte), NULL, buf, 0); +} + +int +read_full_resource_into_alloc_buf(const struct wim_lookup_table_entry *lte, + void **buf_ret) { - return read_resource_prefix(lte, - wim_resource_size(lte), - NULL, buf, - thread_safe ? WIMLIB_RESOURCE_FLAG_THREADSAFE_READ : 0); + int ret; + void *buf; + + if ((size_t)lte->resource_entry.original_size != + lte->resource_entry.original_size) + { + ERROR("Can't read %"PRIu64" byte resource into " + "memory", lte->resource_entry.original_size); + return WIMLIB_ERR_NOMEM; + } + + buf = MALLOC(lte->resource_entry.original_size); + if (!buf) + return WIMLIB_ERR_NOMEM; + + ret = read_full_resource_into_buf(lte, buf); + if (ret) { + FREE(buf); + return ret; + } + + *buf_ret = buf; + return 0; +} + +int +res_entry_to_data(const struct resource_entry *res_entry, + WIMStruct *wim, void **buf_ret) +{ + int ret; + struct wim_lookup_table_entry *lte; + + lte = new_lookup_table_entry(); + if (!lte) + return WIMLIB_ERR_NOMEM; + + copy_resource_entry(<e->resource_entry, res_entry); + lte->unhashed = 1; + lte->part_number = wim->hdr.part_number; + lte_init_wim(lte, wim); + + ret = read_full_resource_into_alloc_buf(lte, buf_ret); + free_lookup_table_entry(lte); + return ret; } struct extract_ctx { @@ -806,13 +962,13 @@ extract_wim_resource(const struct wim_lookup_table_entry *lte, u8 hash[SHA1_HASH_SIZE]; sha1_final(hash, &ctx.sha_ctx); if (!hashes_equal(hash, lte->hash)) { - #ifdef ENABLE_ERROR_MESSAGES - ERROR_WITH_ERRNO("Invalid SHA1 message digest " - "on the following WIM resource:"); - print_lookup_table_entry(lte, stderr); - if (lte->resource_location == RESOURCE_IN_WIM) - ERROR("The WIM file appears to be corrupt!"); - #endif + if (wimlib_print_errors) { + ERROR("Invalid SHA1 message digest " + "on the following WIM resource:"); + print_lookup_table_entry(lte, stderr); + if (lte->resource_location == RESOURCE_IN_WIM) + ERROR("The WIM file appears to be corrupt!"); + } ret = WIMLIB_ERR_INVALID_RESOURCE_HASH; } } @@ -827,21 +983,18 @@ extract_wim_resource(const struct wim_lookup_table_entry *lte, static int extract_wim_chunk_to_fd(const void *buf, size_t len, void *_fd_p) { - int fd = *(int*)_fd_p; - ssize_t ret = full_write(fd, buf, len); - if (ret < len) { + struct filedes *fd = _fd_p; + int ret = full_write(fd, buf, len); + if (ret) ERROR_WITH_ERRNO("Error writing to file descriptor"); - return WIMLIB_ERR_WRITE; - } else { - return 0; - } + return ret; } int extract_wim_resource_to_fd(const struct wim_lookup_table_entry *lte, - int fd, u64 size) + struct filedes *fd, u64 size) { - return extract_wim_resource(lte, size, extract_wim_chunk_to_fd, &fd); + return extract_wim_resource(lte, size, extract_wim_chunk_to_fd, fd); } @@ -867,28 +1020,61 @@ sha1_resource(struct wim_lookup_table_entry *lte) return ret; } -/* - * Copies the file resource specified by the lookup table entry @lte from the - * input WIM to the output WIM that has its FILE * given by - * ((WIMStruct*)wim)->out_fp. - * - * The output_resource_entry, out_refcnt, and part_number fields of @lte are - * updated. - * - * (This function is confusing and should be refactored somehow.) - */ -int -copy_resource(struct wim_lookup_table_entry *lte, void *wim) +/* Translates a WIM resource entry from the on-disk format to an in-memory + * format. */ +void +get_resource_entry(const struct resource_entry_disk *disk_entry, + struct resource_entry *entry) { - WIMStruct *w = wim; - int ret; + /* Note: disk_entry may not be 8 byte aligned--- in that case, the + * offset and original_size members will be unaligned. (This should be + * okay since `struct resource_entry_disk' is declared as packed.) */ + + /* 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); - ret = write_wim_resource(lte, w->out_fp, - wim_resource_compression_type(lte), - <e->output_resource_entry, 0); - if (ret == 0) { - lte->out_refcnt = lte->refcnt; - lte->part_number = w->hdr.part_number; + /* offset and original_size are truncated to 62 bits to avoid possible + * overflows, when converting to a signed 64-bit integer (off_t) or when + * adding size or original_size. This is okay since no one would ever + * actually have a WIM bigger than 4611686018427387903 bytes... */ + if (entry->offset & 0xc000000000000000ULL) { + WARNING("Truncating offset in resource entry"); + entry->offset &= 0x3fffffffffffffffULL; } - return ret; + if (entry->original_size & 0xc000000000000000ULL) { + WARNING("Truncating original_size in resource entry"); + entry->original_size &= 0x3fffffffffffffffULL; + } +} + +/* Translates a WIM resource entry from an in-memory format into the on-disk + * format. */ +void +put_resource_entry(const struct resource_entry *entry, + struct resource_entry_disk *disk_entry) +{ + /* Note: disk_entry may not be 8 byte aligned--- in that case, the + * offset and original_size members will be unaligned. (This should be + * okay since `struct resource_entry_disk' is declared as packed.) */ + u64 size = entry->size; + + disk_entry->size[0] = size >> 0; + disk_entry->size[1] = size >> 8; + disk_entry->size[2] = size >> 16; + disk_entry->size[3] = size >> 24; + disk_entry->size[4] = size >> 32; + disk_entry->size[5] = size >> 40; + disk_entry->size[6] = size >> 48; + disk_entry->flags = entry->flags; + disk_entry->offset = cpu_to_le64(entry->offset); + disk_entry->original_size = cpu_to_le64(entry->original_size); }