X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=src%2Fresource.c;h=d3380caf66a7380fa9d9b7b5344539b9663f6d51;hb=720db87557918105b17b51b03f264ddb9b89d2b9;hp=600bf5ba1321bb772f4d788ccfe33aad456c661b;hpb=885632f08c75c1d7bb5d25436231c78f6ad7e0c0;p=wimlib diff --git a/src/resource.c b/src/resource.c index 600bf5ba..d3380caf 100644 --- a/src/resource.c +++ b/src/resource.c @@ -1,44 +1,64 @@ /* * resource.c * - * Read uncompressed and compressed metadata and file resources. - * - * Copyright (C) 2010 Carl Thijssen - * Copyright (C) 2012 Eric Biggers + * Read uncompressed and compressed metadata and file resources from a WIM file. + */ + +/* + * Copyright (C) 2012, 2013 Eric Biggers * - * wimlib - Library for working with WIM files + * This file is part of wimlib, a library for working with WIM files. * - * This library is free software; you can redistribute it and/or modify it under - * the terms of the GNU Lesser General Public License as published by the Free - * Software Foundation; either version 2.1 of the License, or (at your option) any - * later version. + * wimlib is free software; you can redistribute it and/or modify it under the + * 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. * - * This library 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. + * 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 General Public License for more details. * - * You should have received a copy of the GNU Lesser General Public License along - * with this library; if not, write to the Free Software Foundation, Inc., 59 - * Temple Place, Suite 330, Boston, MA 02111-1307 USA + * 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 "io.h" +#include "dentry.h" +#include "lookup_table.h" +#include "buffer_io.h" #include "lzx.h" #include "xpress.h" -#include "dentry.h" -#include +#include "sha1.h" + +#ifdef __WIN32__ +# include "win32.h" +#endif + #include +#include +#include +#include + +#ifdef WITH_NTFS_3G +# include +# include +# include +# include +#endif + +#if defined(__WIN32__) && !defined(INVALID_HANDLE_VALUE) +# define INVALID_HANDLE_VALUE ((HANDLE)(-1)) +#endif -/* +/* * Reads all or part of a compressed resource into an in-memory buffer. * * @fp: The FILE* for the WIM file. - * @resource_compressed_size: The compressed size of the resource. + * @resource_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. + * @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 @@ -48,28 +68,27 @@ * * Returns zero on success, nonzero on failure. */ -static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, - u64 resource_uncompressed_size, - u64 resource_offset, int resource_ctype, - u64 len, u64 offset, u8 contents_ret[]) +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, void *contents_ret) { - DEBUG2("comp size = %"PRIu64", " - "uncomp size = %"PRIu64", " - "res offset = %"PRIu64"\n", - resource_compressed_size, - resource_uncompressed_size, - resource_offset); - DEBUG2("resource_ctype = %s, len = %"PRIu64", offset = %"PRIu64"\n", - wimlib_get_compression_type_string(resource_ctype), - len, offset); + DEBUG2("comp size = %"PRIu64", uncomp size = %"PRIu64", " + "res offset = %"PRIu64"", + resource_compressed_size, + resource_uncompressed_size, + resource_offset); + DEBUG2("resource_ctype = %"TS", len = %"PRIu64", offset = %"PRIu64"", + wimlib_get_compression_type_string(resource_ctype), len, offset); /* Trivial case */ if (len == 0) return 0; - int (*decompress)(const void *, uint, void *, uint); + int (*decompress)(const void *, unsigned, void *, unsigned); /* Set the appropriate decompress function. */ - if (resource_ctype == WIM_COMPRESSION_TYPE_LZX) + if (resource_ctype == WIMLIB_COMPRESSION_TYPE_LZX) decompress = lzx_decompress; else decompress = xpress_decompress; @@ -83,7 +102,7 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, * 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. + * follows the chunk table and therefore must have an offset of 0. */ /* Calculate how many chunks the resource conists of in its entirety. */ @@ -131,7 +150,7 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, /* 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) ? + u64 chunk_entry_size = (resource_uncompressed_size >= (u64)1 << 32) ? 8 : 4; /* Size of the full chunk table in the WIM file. */ @@ -145,17 +164,16 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_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) ? + 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 + + 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("Failed to seek to byte %"PRIu64" " - "to read chunk table of compressed " - "resource: %m\n", - file_offset_of_needed_chunk_entries); + 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; } @@ -177,29 +195,28 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, if (chunk_entry_size == 4) { u32 *entries = (u32*)chunk_tab_buf; while (num_needed_chunk_entries--) - *chunk_tab_p++ = to_le32(*entries++); + *chunk_tab_p++ = le32_to_cpu(*entries++); } else { u64 *entries = (u64*)chunk_tab_buf; while (num_needed_chunk_entries--) - *chunk_tab_p++ = to_le64(*entries++); + *chunk_tab_p++ = le64_to_cpu(*entries++); } /* Done with the chunk table now. We must now seek to the first chunk * that is needed for the read. */ - u64 file_offset_of_first_needed_chunk = resource_offset + + 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("Failed to seek to byte %"PRIu64" " - "to read first chunk of compressed " - "resource: %m\n", - file_offset_of_first_needed_chunk); + ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" to read " + "first chunk of compressed resource", + file_offset_of_first_needed_chunk); return WIMLIB_ERR_READ; } /* Pointer to current position in the output buffer for uncompressed * data. */ - u8 *out_p = (u8*)contents_ret; + u8 *out_p = 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 @@ -213,18 +230,19 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, /* Decompress all the chunks. */ for (u64 i = start_chunk; i <= end_chunk; i++) { - DEBUG2("Chunk %"PRIu64" (start %"PRIu64", end %"PRIu64")\n", - i, start_chunk, end_chunk); + DEBUG2("Chunk %"PRIu64" (start %"PRIu64", end %"PRIu64").", + i, start_chunk, end_chunk); /* Calculate the sizes of the compressed chunk and of the * uncompressed chunk. */ - uint compressed_chunk_size, uncompressed_chunk_size; + 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] - + compressed_chunk_size = chunk_offsets[i + 1 - start_chunk] - chunk_offsets[i - start_chunk]; uncompressed_chunk_size = WIM_CHUNK_SIZE; } else { @@ -232,15 +250,15 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, * 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. + * 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 - + compressed_chunk_size = resource_compressed_size - chunk_table_size - chunk_offsets[i - start_chunk]; - uncompressed_chunk_size = resource_uncompressed_size % + uncompressed_chunk_size = resource_uncompressed_size % WIM_CHUNK_SIZE; /* If the remainder is 0, the last chunk actually @@ -249,8 +267,9 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, uncompressed_chunk_size = WIM_CHUNK_SIZE; } - DEBUG2("compressed_chunk_size = %u, uncompressed_chunk_size = %u\n", - compressed_chunk_size, uncompressed_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 */ @@ -266,12 +285,12 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, end_offset = WIM_CHUNK_SIZE - 1; u64 partial_chunk_size = end_offset + 1 - start_offset; - bool is_partial_chunk = (partial_chunk_size != + bool is_partial_chunk = (partial_chunk_size != uncompressed_chunk_size); - DEBUG2("start_offset = %u, end_offset = %u\n", start_offset, - end_offset); - DEBUG2("partial_chunk_size = %u\n", partial_chunk_size); + DEBUG2("start_offset = %"PRIu64", end_offset = %"PRIu64"", + start_offset, end_offset); + DEBUG2("partial_chunk_size = %"PRIu64"", partial_chunk_size); /* This is undocumented, but chunks can be uncompressed. This * appears to always be the case when the compressed chunk size @@ -281,12 +300,12 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, if (start_offset != 0) { if (fseeko(fp, start_offset, SEEK_CUR) != 0) { - ERROR("Uncompressed partial chunk " - "fseek() error: %m\n"); + ERROR_WITH_ERRNO("Uncompressed partial " + "chunk fseek() error"); return WIMLIB_ERR_READ; } } - if (fread(out_p, 1, partial_chunk_size, fp) != + if (fread(out_p, 1, partial_chunk_size, fp) != partial_chunk_size) goto err; } else { @@ -294,7 +313,7 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, int ret; /* Read the compressed data into compressed_buf. */ - if (fread(compressed_buf, 1, compressed_chunk_size, + if (fread(compressed_buf, 1, compressed_chunk_size, fp) != compressed_chunk_size) goto err; @@ -305,14 +324,13 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, ret = decompress(compressed_buf, compressed_chunk_size, - uncompressed_buf, + uncompressed_buf, uncompressed_chunk_size); if (ret != 0) return WIMLIB_ERR_DECOMPRESSION; memcpy(out_p, uncompressed_buf + start_offset, partial_chunk_size); } else { - DEBUG2("out_p = %p\n"); ret = decompress(compressed_buf, compressed_chunk_size, out_p, @@ -331,141 +349,42 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, err: if (feof(fp)) - ERROR("Unexpected EOF in compressed file resource\n"); + ERROR("Unexpected EOF in compressed file resource"); else - ERROR("Error reading compressed file resource: %m\n"); + ERROR_WITH_ERRNO("Error reading compressed file resource"); return WIMLIB_ERR_READ; } -/* +/* * Reads uncompressed data from an open file stream. */ -int read_uncompressed_resource(FILE *fp, u64 offset, u64 len, - u8 contents_ret[]) +int +read_uncompressed_resource(FILE *fp, u64 offset, u64 len, void *contents_ret) { if (fseeko(fp, offset, SEEK_SET) != 0) { ERROR("Failed to seek to byte %"PRIu64" of input file " - "to read uncompressed resource " - "(len = %"PRIu64")!\n", offset, len); + "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!\n"); + ERROR("Unexpected EOF in uncompressed file resource"); } else { ERROR("Failed to read %"PRIu64" bytes from " - "uncompressed resource at offset " - "%"PRIu64"\n", len, offset); + "uncompressed resource at offset %"PRIu64, + len, offset); } return WIMLIB_ERR_READ; } return 0; } -/* - * Reads a WIM resource. - * - * @fp: The FILE* for the WIM file. - * @resource_size: The compressed size of the resource. - * @resource_original_size: The uncompressed size of the resource. - * @resource_offset: The offset of the resource in the stream @fp. - * @resource_ctype: The compression type of the resource. - * (WIM_COMPRESSION_TYPE_*) - * @len: How many bytes of the resource should be read. - * @offset: The offset within the resource at which the read - * will occur. - * - * To read the whole file resource, specify offset = - * 0 and len = resource_original_size, or call - * read_full_resource(). - * - * @contents_ret: An array, that must have length at least @len, - * into which the uncompressed contents of - * the file resource starting at @offset and - * continuing for @len bytes will be written. - * - * @return: Zero on success, nonzero on failure. Failure may be due to - * being unable to read the data from the WIM file at the - * specified length and offset, or it may be due to the - * compressed data (if the data is compressed) being - * invalid. - */ -int read_resource(FILE *fp, u64 resource_size, u64 resource_original_size, - u64 resource_offset, int resource_ctype, u64 len, - u64 offset, void *contents_ret) -{ - if (resource_ctype == WIM_COMPRESSION_TYPE_NONE) { - if (resource_size != resource_original_size) { - ERROR("Resource with original size %"PRIu64" " - "bytes is marked as uncompressed, \n", - resource_original_size); - ERROR(" but its actual size is %"PRIu64" " - "bytes!\n", - resource_size); - return WIMLIB_ERR_INVALID_RESOURCE_SIZE; - } - return read_uncompressed_resource(fp, - resource_offset + offset, - len, contents_ret); - } else { - return read_compressed_resource(fp, resource_size, - resource_original_size, resource_offset, - resource_ctype, len, offset, contents_ret); - } -} - - -/* - * Extracts the first @size bytes file resource specified by @entry to the open - * file @fd. Returns nonzero on error. - * - * XXX - * This function is somewhat redundant with uncompress_resource(). The - * main difference is that this function writes to a file descriptor using - * low-level calls to write() rather than to a FILE* with fwrite(); also this - * function allows only up to @size bytes to be extracted. - */ -int extract_resource_to_fd(WIMStruct *w, const struct resource_entry *entry, - int fd, u64 size) -{ - u64 num_chunks; - u64 n; - u8 buf[min(size, WIM_CHUNK_SIZE)]; - int res_ctype; - u64 offset; - u64 i; - int ret; - - errno = 0; - - num_chunks = (size + WIM_CHUNK_SIZE - 1) / WIM_CHUNK_SIZE; - n = WIM_CHUNK_SIZE; - res_ctype = wim_resource_compression_type(w, entry); - offset = 0; - for (i = 0; i < num_chunks; i++) { - if (i == num_chunks - 1) { - n = size % WIM_CHUNK_SIZE; - if (n == 0) { - n = WIM_CHUNK_SIZE; - } - } - - ret = read_resource(w->fp, entry->size, entry->original_size, - entry->offset, res_ctype, n, offset, buf); - if (ret != 0) - return ret; - - if (full_write(fd, buf, n) != n) - return WIMLIB_ERR_WRITE; - offset += n; - } - return ret; -} - /* 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) +const u8 * +get_resource_entry(const u8 *p, struct resource_entry *entry) { u64 size; u8 flags; @@ -474,15 +393,29 @@ const u8 *get_resource_entry(const u8 *p, struct resource_entry *entry) p = get_u8(p, &flags); entry->size = size; entry->flags = flags; + + /* 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; } /* 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) +u8 * +put_resource_entry(u8 *p, const struct resource_entry *entry) { p = put_u56(p, entry->size); p = put_u8(p, entry->flags); @@ -491,127 +424,322 @@ u8 *put_resource_entry(u8 *p, const struct resource_entry *entry) return p; } -/* Given the compression type for the WIM file as a whole as the flags field of - * a resource entry, returns the compression type for that resource entry. */ -int resource_compression_type(int wim_ctype, int reshdr_flags) +#ifdef WITH_FUSE +static FILE * +wim_get_fp(WIMStruct *w) { - if (wim_ctype == WIM_COMPRESSION_TYPE_NONE) { - return WIM_COMPRESSION_TYPE_NONE; - } else { - if (reshdr_flags & WIM_RESHDR_FLAG_COMPRESSED) - return wim_ctype; - else - return WIM_COMPRESSION_TYPE_NONE; + pthread_mutex_lock(&w->fp_tab_mutex); + FILE *fp; + + wimlib_assert(w->filename != NULL); + + 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; + } } + 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: + pthread_mutex_unlock(&w->fp_tab_mutex); + return fp; +} + +static int +wim_release_fp(WIMStruct *w, FILE *fp) +{ + int ret = 0; + FILE **fp_tab; + + pthread_mutex_lock(&w->fp_tab_mutex); + + for (size_t i = 0; i < w->num_allocated_fps; i++) { + if (w->fp_tab[i] == NULL) { + w->fp_tab[i] = fp; + goto out; + } + } + + fp_tab = REALLOC(w->fp_tab, sizeof(FILE*) * (w->num_allocated_fps + 4)); + if (!fp_tab) { + ret = WIMLIB_ERR_NOMEM; + goto out; + } + 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: + pthread_mutex_unlock(&w->fp_tab_mutex); + return ret; } +#endif /* !WITH_FUSE */ -/* - * 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. +/* + * Reads some data from the resource corresponding to a WIM lookup table entry. * - * @fp: The FILE* for the input WIM file. - * @res_entry: The resource entry for the metadata resource (a.k.a the metadata - * for the metadata) - * @wim_ctype: The compression type of the WIM file. - * @root_dentry_p: A pointer to a pointer to a struct dentry structure into which the - * root dentry is allocated and returned. + * @lte: The WIM lookup table entry for the resource. + * @buf: Buffer into which to write the data. + * @size: Number of bytes to read. + * @offset: Offset at which to start reading the resource. * - * @return: True on success, false on failure. + * Returns zero on success, nonzero on failure. */ -int read_metadata_resource(FILE *fp, const struct resource_entry *res_entry, - int wim_ctype, struct dentry **root_dentry_p) +int +read_wim_resource(const struct wim_lookup_table_entry *lte, void *buf, + size_t size, u64 offset, int flags) { - u8 *buf; int ctype; - u32 dentry_offset; - int ret; - struct dentry *dentry; + int ret = 0; + FILE *fp; - DEBUG("Reading metadata resource: length = %lu, offset = %lu\n", - res_entry->original_size, res_entry->offset); + /* We shouldn't be allowing read over-runs in any part of the library. + * */ + if (flags & WIMLIB_RESOURCE_FLAG_RAW) + wimlib_assert(offset + size <= lte->resource_entry.size); + else + wimlib_assert(offset + size <= lte->resource_entry.original_size); + + switch (lte->resource_location) { + case RESOURCE_IN_WIM: + /* The resource is in a WIM file, and its WIMStruct is given by + * the lte->wim member. The resource may be either compressed + * or uncompressed. */ + wimlib_assert(lte->wim != NULL); + + #ifdef WITH_FUSE + if (flags & WIMLIB_RESOURCE_FLAG_MULTITHREADED) { + fp = wim_get_fp(lte->wim); + if (!fp) + return WIMLIB_ERR_OPEN; + } else + #endif + { + wimlib_assert(!(flags & WIMLIB_RESOURCE_FLAG_MULTITHREADED)); + wimlib_assert(lte->wim->fp != NULL); + fp = lte->wim->fp; + } - if (res_entry->original_size < 8) { - ERROR("Expected at least 8 bytes for the metadata " - "resource!\n"); - return WIMLIB_ERR_INVALID_RESOURCE_SIZE; - } + ctype = wim_resource_compression_type(lte); - /* Allocate memory for the uncompressed metadata resource. */ - buf = MALLOC(res_entry->original_size); + wimlib_assert(ctype != WIMLIB_COMPRESSION_TYPE_NONE || + (lte->resource_entry.original_size == + lte->resource_entry.size)); - if (!buf) { - ERROR("Failed to allocate %"PRIu64" bytes for uncompressed " - "metadata resource!\n", - res_entry->original_size); - return WIMLIB_ERR_NOMEM; + if ((flags & WIMLIB_RESOURCE_FLAG_RAW) + || ctype == WIMLIB_COMPRESSION_TYPE_NONE) + ret = read_uncompressed_resource(fp, + lte->resource_entry.offset + offset, + size, buf); + else + ret = read_compressed_resource(fp, + lte->resource_entry.size, + lte->resource_entry.original_size, + lte->resource_entry.offset, + ctype, size, offset, buf); + #ifdef WITH_FUSE + if (flags & WIMLIB_RESOURCE_FLAG_MULTITHREADED) { + int ret2 = wim_release_fp(lte->wim, fp); + if (ret == 0) + ret = ret2; + } + #endif + break; + case RESOURCE_IN_STAGING_FILE: + case RESOURCE_IN_FILE_ON_DISK: + /* The resource is in some file on the external filesystem and + * needs to be read uncompressed */ + wimlib_assert(lte->file_on_disk != NULL); + BUILD_BUG_ON(<e->file_on_disk != <e->staging_file_name); + /* Use existing file pointer if available; otherwise open one + * temporarily */ + if (lte->file_on_disk_fp) { + fp = lte->file_on_disk_fp; + } else { + fp = tfopen(lte->file_on_disk, T("rb")); + if (!fp) { + ERROR_WITH_ERRNO("Failed to open the file " + "`%"TS"'", lte->file_on_disk); + ret = WIMLIB_ERR_OPEN; + break; + } + } + ret = read_uncompressed_resource(fp, offset, size, buf); + if (fp != lte->file_on_disk_fp) + fclose(fp); + break; +#ifdef __WIN32__ + case RESOURCE_WIN32: + wimlib_assert(lte->win32_file_on_disk_fp != INVALID_HANDLE_VALUE); + ret = win32_read_file(lte->file_on_disk, + lte->win32_file_on_disk_fp, offset, + size, buf); + break; +#endif + case RESOURCE_IN_ATTACHED_BUFFER: + /* The resource is directly attached uncompressed in an + * in-memory buffer. */ + wimlib_assert(lte->attached_buffer != NULL); + memcpy(buf, lte->attached_buffer + offset, size); + break; +#ifdef WITH_NTFS_3G + case RESOURCE_IN_NTFS_VOLUME: + wimlib_assert(lte->ntfs_loc != NULL); + wimlib_assert(lte->attr != NULL); + if (lte->ntfs_loc->is_reparse_point) + offset += 8; + if (ntfs_attr_pread(lte->attr, offset, size, buf) != size) { + ERROR_WITH_ERRNO("Error reading NTFS attribute " + "at `%"TS"'", + lte->ntfs_loc->path); + ret = WIMLIB_ERR_NTFS_3G; + } + break; +#endif + default: + wimlib_assert(0); + ret = -1; + break; } + return ret; +} - /* 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 err1; - - DEBUG("Finished reading metadata resource into memory.\n"); +/* + * Reads all the data from the resource corresponding to a WIM lookup table + * entry. + * + * @lte: The WIM lookup table entry for the resource. + * @buf: Buffer into which to write the data. It must be at least + * wim_resource_size(lte) bytes long. + * + * Returns 0 on success; nonzero on failure. + */ +int +read_full_wim_resource(const struct wim_lookup_table_entry *lte, + void *buf, int flags) +{ + return read_wim_resource(lte, buf, wim_resource_size(lte), 0, flags); +} -#if 0 - /* Read the security data into a WIMSecurityData structure. */ - if (!read_security_data(buf, res_entry->original_size, sd)) - goto err1; -#endif +/* 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, + extract_chunk_func_t extract_chunk, + void *extract_chunk_arg) +{ + u64 bytes_remaining = size; + u8 buf[min(WIM_CHUNK_SIZE, bytes_remaining)]; + u64 offset = 0; + int ret = 0; + u8 hash[SHA1_HASH_SIZE]; + bool check_hash = (size == wim_resource_size(lte)); + SHA_CTX ctx; + + if (check_hash) + sha1_init(&ctx); + + while (bytes_remaining) { + u64 to_read = min(bytes_remaining, sizeof(buf)); + ret = read_wim_resource(lte, buf, to_read, offset, 0); + if (ret != 0) + return ret; + if (check_hash) + sha1_update(&ctx, buf, to_read); + ret = extract_chunk(buf, to_read, offset, extract_chunk_arg); + if (ret != 0) { + ERROR_WITH_ERRNO("Error extracting WIM resource"); + return ret; + } + bytes_remaining -= to_read; + offset += to_read; + } + if (check_hash) { + sha1_final(hash, &ctx); + if (!hashes_equal(hash, lte->hash)) { + #ifdef ENABLE_ERROR_MESSAGES + ERROR("Invalid checksum on the following WIM resource:"); + print_lookup_table_entry(lte, stderr); + #endif + return WIMLIB_ERR_INVALID_RESOURCE_HASH; + } + } + return 0; +} - dentry = MALLOC(sizeof(struct dentry)); - if (!dentry) { - ERROR("Failed to allocate %zu bytes for root dentry!\n", - sizeof(struct dentry)); - ret = WIMLIB_ERR_NOMEM; - goto err1; +/* Write @n bytes from @buf to the file descriptor @fd, retrying on internupt + * and on short writes. + * + * 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 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. */ - get_u32(buf, &dentry_offset); - dentry_offset += (8 - dentry_offset % 8) % 8; - - ret = read_dentry(buf, res_entry->original_size, dentry_offset, dentry); - if (ret != 0) - goto err1; +int +extract_wim_chunk_to_fd(const void *buf, size_t len, u64 offset, void *arg) +{ + int fd = *(int*)arg; + ssize_t ret = full_write(fd, buf, len); + if (ret < len) { + ERROR_WITH_ERRNO("Error writing to file descriptor"); + return WIMLIB_ERR_WRITE; + } else { + return 0; + } +} - /* This is the root dentry, so set its pointers correctly. */ - dentry->parent = dentry; - dentry->next = dentry; - dentry->prev = dentry; +/* + * 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) +{ + WIMStruct *w = wim; + int ret; - /* Now read the entire directory entry tree. */ - ret = read_dentry_tree(buf, res_entry->original_size, dentry); - if (ret != 0) - goto err2; + if ((lte->resource_entry.flags & WIM_RESHDR_FLAG_METADATA) && + !w->write_metadata) + return 0; - /* Calculate the full paths in the dentry tree. */ - ret = for_dentry_in_tree(dentry, calculate_dentry_full_path, NULL); + ret = write_wim_resource(lte, w->out_fp, + wim_resource_compression_type(lte), + <e->output_resource_entry, 0); if (ret != 0) - goto err2; - - *root_dentry_p = dentry; - FREE(buf); - return ret; -err2: - free_dentry_tree(dentry, NULL, false); -err1: - FREE(buf); - return ret; + return ret; + lte->out_refcnt = lte->refcnt; + lte->part_number = w->hdr.part_number; + return 0; } - -