X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;ds=inline;f=src%2Fresource.c;h=a7a831980b562e3915721ff62044d08e1da4ecb5;hb=3f9b53a4a214a254bb27ed30994faf2a0fd12375;hp=600bf5ba1321bb772f4d788ccfe33aad456c661b;hpb=885632f08c75c1d7bb5d25436231c78f6ad7e0c0;p=wimlib diff --git a/src/resource.c b/src/resource.c index 600bf5ba..a7a83198 100644 --- a/src/resource.c +++ b/src/resource.c @@ -1,78 +1,121 @@ /* * 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 "lzx.h" -#include "xpress.h" #include "dentry.h" -#include +#include "lookup_table.h" +#include "buffer_io.h" +#include "sha1.h" + +#ifdef __WIN32__ +# include "win32.h" +#endif + #include +#include +#include +#include +#include + +#ifdef HAVE_ALLOCA_H +# include +#endif + +/* 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; +} -/* - * Reads all or part of a compressed resource into an in-memory buffer. +/* Read @n bytes from the file descriptor @fd to the buffer @buf, retrying on + * internupt and on short reads. * - * @fp: The FILE* for the WIM file. - * @resource_compressed_size: The compressed size of the resource. - * @resource_uncompressed_size: The uncompressed size of the resource. - * @resource_offset: The offset of the start of the resource from - * the start of the stream @fp. - * @resource_ctype: The compression type of the resource. - * @len: The number of bytes of uncompressed data to read from - * the resource. - * @offset: The offset of the bytes to read within the uncompressed - * resource. - * @contents_len: An array into which the uncompressed data is written. - * It must be at least @len bytes long. + * Returns short count and set errno on failure. */ +static size_t +full_read(int fd, void *buf, size_t n) +{ + 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; +} + +/* + * Reads all or part of a compressed WIM resource. * * 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, + consume_data_callback_t cb, + void *ctx_or_buf) { + int 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); /* 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) - decompress = lzx_decompress; + if (resource_ctype == WIMLIB_COMPRESSION_TYPE_LZX) + decompress = wimlib_lzx_decompress; else - decompress = xpress_decompress; + 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 @@ -83,10 +126,11 @@ 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. */ + /* 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. */ @@ -113,9 +157,22 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, 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]; + /* Allocate the chunk table. It will only contain offsets for the + * chunks that are actually needed for this read. */ + u64 *chunk_offsets; + bool chunk_offsets_malloced; + if (num_needed_chunks < 1000) { + chunk_offsets = alloca(num_needed_chunks * sizeof(u64)); + chunk_offsets_malloced = false; + } else { + chunk_offsets = malloc(num_needed_chunks * sizeof(u64)); + if (!chunk_offsets) { + ERROR("Failed to allocate chunk table " + "with %"PRIu64" entries", num_needed_chunks); + return WIMLIB_ERR_NOMEM; + } + chunk_offsets_malloced = true; + } /* Set the implicit offset of the first chunk if it is included in the * needed chunks. @@ -131,7 +188,7 @@ 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. */ @@ -145,27 +202,24 @@ 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); - return WIMLIB_ERR_READ; - } + 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; - u8 chunk_tab_buf[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; if (fread(chunk_tab_buf, 1, size, fp) != size) - goto err; + goto read_error; /* Now fill in chunk_offsets from the entries we have read in * chunk_tab_buf. */ @@ -177,29 +231,29 @@ 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); - return WIMLIB_ERR_READ; - } + if (fseeko(fp, file_offset_of_first_needed_chunk, SEEK_SET)) + goto read_error; /* Pointer to current position in the output buffer for uncompressed - * data. */ - u8 *out_p = (u8*)contents_ret; + * data. Alternatively, if using a callback function, we repeatedly + * fill a temporary buffer to feed data into the callback function. */ + 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 @@ -207,24 +261,21 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, * 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]; - + void *compressed_buf = alloca(WIM_CHUNK_SIZE - 1); /* 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); - /* 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 +283,15 @@ 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 @@ -249,10 +300,6 @@ 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); - - /* Figure out how much of this chunk we actually need to read */ u64 start_offset; if (i == start_chunk) @@ -265,207 +312,115 @@ static int read_compressed_resource(FILE *fp, u64 resource_compressed_size, 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\n", start_offset, - end_offset); - DEBUG2("partial_chunk_size = %u\n", partial_chunk_size); + 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) { - /* Probably an uncompressed chunk */ + /* Uncompressed chunk */ - if (start_offset != 0) { - if (fseeko(fp, start_offset, SEEK_CUR) != 0) { - ERROR("Uncompressed partial chunk " - "fseek() error: %m\n"); - return WIMLIB_ERR_READ; - } - } - if (fread(out_p, 1, partial_chunk_size, fp) != - partial_chunk_size) - goto err; + if (start_offset != 0) + if (fseeko(fp, start_offset, SEEK_CUR)) + goto read_error; + if (fread(out_p, 1, partial_chunk_size, fp) != partial_chunk_size) + goto read_error; } else { /* Compressed chunk */ - 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; + goto read_error; - /* For partial chunks we must buffer the uncompressed - * data because we don't need all of it. */ - if (is_partial_chunk) { + /* 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) { 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; + compressed_chunk_size, + uncompressed_buf, + uncompressed_chunk_size); + if (ret) { + ret = WIMLIB_ERR_DECOMPRESSION; + goto out; + } memcpy(out_p, uncompressed_buf + start_offset, - partial_chunk_size); + partial_chunk_size); } else { - DEBUG2("out_p = %p\n"); ret = decompress(compressed_buf, - compressed_chunk_size, - out_p, - uncompressed_chunk_size); - if (ret != 0) - return WIMLIB_ERR_DECOMPRESSION; + compressed_chunk_size, + out_p, + uncompressed_chunk_size); + if (ret) { + ret = WIMLIB_ERR_DECOMPRESSION; + goto out; + } } } - - /* 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; + } 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; + } } - return 0; + ret = 0; +out: + if (chunk_offsets_malloced) + FREE(chunk_offsets); + return ret; -err: +read_error: 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"); - return WIMLIB_ERR_READ; + ERROR_WITH_ERRNO("Error reading compressed file resource"); + ret = WIMLIB_ERR_READ; + goto out; } -/* +/* * 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 void * +get_resource_entry(const void *p, struct resource_entry *entry) { u64 size; u8 flags; @@ -474,15 +429,29 @@ 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) +void * +put_resource_entry(void *p, const struct resource_entry *entry) { p = put_u56(p, entry->size); p = put_u8(p, entry->flags); @@ -491,127 +460,433 @@ 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) +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; +#ifdef WITH_FUSE + 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_unlock; + } } + 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 */ + fp = w->fp; +#endif /* !WITH_FUSE */ + return fp; } -/* - * 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. - * @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. - * - * @return: True on success, false on failure. - */ -int read_metadata_resource(FILE *fp, const struct resource_entry *res_entry, - int wim_ctype, struct dentry **root_dentry_p) +static int +wim_release_fp(WIMStruct *w, FILE *fp) { - u8 *buf; - int ctype; - u32 dentry_offset; + int ret = 0; +#ifdef WITH_FUSE + 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_unlock; + } + } + + 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 */ + return ret; +} + +static 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) +{ + FILE *wim_fp; + WIMStruct *wim; int ret; - struct dentry *dentry; - DEBUG("Reading metadata resource: length = %lu, offset = %lu\n", - res_entry->original_size, res_entry->offset); + wimlib_assert(lte->resource_location == RESOURCE_IN_WIM); + wimlib_assert(offset + size <= lte->resource_entry.original_size); + + wim = lte->wim; - if (res_entry->original_size < 8) { - ERROR("Expected at least 8 bytes for the metadata " - "resource!\n"); - return WIMLIB_ERR_INVALID_RESOURCE_SIZE; + if (flags & WIMLIB_RESOURCE_FLAG_THREADSAFE_READ) { + wim_fp = wim_get_fp(wim); + if (!wim_fp) { + ret = -1; + goto out; + } + } else { + wim_fp = lte->wim->fp; } - /* Allocate memory for the uncompressed metadata resource. */ - buf = MALLOC(res_entry->original_size); + wimlib_assert(wim_fp != NULL); + + if (lte->resource_entry.flags & WIM_RESHDR_FLAG_COMPRESSED && + !(flags & WIMLIB_RESOURCE_FLAG_RAW)) + { + 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 { + offset += lte->resource_entry.offset; - if (!buf) { - ERROR("Failed to allocate %"PRIu64" bytes for uncompressed " - "metadata resource!\n", - res_entry->original_size); - return WIMLIB_ERR_NOMEM; + 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) { + /* 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) + goto read_error; + ret = cb(buf, bytes_read, ctx_or_buf); + if (ret) + goto out_release_fp; + size -= bytes_read; + } + } else { + /* Send data directly to a buffer */ + if (fread(ctx_or_buf, 1, size, wim_fp) != size) + goto read_error; + } + ret = 0; + } + goto out_release_fp; +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) + ret |= wim_release_fp(wim, wim_fp); +out: + if (ret) { + if (errno == 0) + errno = EIO; + } + 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; +int +read_partial_wim_resource_into_buf(const struct wim_lookup_table_entry *lte, + size_t size, u64 offset, void *buf, + bool threadsafe) +{ + return read_partial_wim_resource(lte, size, NULL, buf, + threadsafe ? WIMLIB_RESOURCE_FLAG_THREADSAFE_READ : 0, + offset); +} - DEBUG("Finished reading metadata resource into memory.\n"); +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) +{ + return read_partial_wim_resource(lte, size, cb, ctx_or_buf, flags, 0); +} -#if 0 - /* Read the security data into a WIMSecurityData structure. */ - if (!read_security_data(buf, res_entry->original_size, sd)) - goto err1; -#endif - 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; +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) +{ + const tchar *filename = lte->file_on_disk; + int ret; + int fd; + size_t bytes_read; + + fd = open(filename, O_RDONLY); + if (fd < 0) { + ERROR_WITH_ERRNO("Can't open \"%"TS"\"", filename); + return WIMLIB_ERR_OPEN; + } + 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) + goto read_error; + ret = cb(buf, bytes_read, ctx_or_buf); + if (ret) + goto out_close; + size -= bytes_read; + } + } else { + /* Send data directly to a buffer */ + bytes_read = full_read(fd, ctx_or_buf, size); + if (bytes_read != size) + 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); + return ret; +} - /* 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; - - /* This is the root dentry, so set its pointers correctly. */ - dentry->parent = dentry; - dentry->next = dentry; - dentry->prev = dentry; - - /* Now read the entire directory entry tree. */ - ret = read_dentry_tree(buf, res_entry->original_size, dentry); - if (ret != 0) - goto err2; - - /* Calculate the full paths in the dentry tree. */ - ret = for_dentry_in_tree(dentry, calculate_dentry_full_path, NULL); - if (ret != 0) - goto err2; - - *root_dentry_p = dentry; - FREE(buf); +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; + + 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; +} + +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 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). + * + * 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. + */ +int +read_resource_prefix(const struct wim_lookup_table_entry *lte, + u64 size, consume_data_callback_t cb, void *ctx_or_buf, + int flags) +{ + static const read_resource_prefix_handler_t handlers[] = { + [RESOURCE_IN_WIM] = read_wim_resource_prefix, + [RESOURCE_IN_FILE_ON_DISK] = read_file_on_disk_prefix, + [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] = read_win32_file_prefix, + [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 +read_full_resource_into_buf(const struct wim_lookup_table_entry *lte, + void *buf, bool thread_safe) +{ + return read_resource_prefix(lte, + wim_resource_size(lte), + NULL, buf, + thread_safe ? WIMLIB_RESOURCE_FLAG_THREADSAFE_READ : 0); +} + +struct extract_ctx { + SHA_CTX sha_ctx; + consume_data_callback_t extract_chunk; + void *extract_chunk_arg; +}; + +static int +extract_chunk_sha1_wrapper(const void *chunk, size_t chunk_size, + void *_ctx) +{ + struct extract_ctx *ctx = _ctx; + + sha1_update(&ctx->sha_ctx, chunk, chunk_size); + return ctx->extract_chunk(chunk, chunk_size, ctx->extract_chunk_arg); +} + +/* 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) +{ + int ret; + 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)) { + #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!"); + ret = WIMLIB_ERR_INVALID_RESOURCE_HASH; + #endif + } + } + } else { + /* Don't do SHA1 */ + ret = read_resource_prefix(lte, size, extract_chunk, + extract_chunk_arg, 0); + } return ret; -err2: - free_dentry_tree(dentry, NULL, false); -err1: - FREE(buf); +} + +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) { + ERROR_WITH_ERRNO("Error writing to file descriptor"); + return WIMLIB_ERR_WRITE; + } else { + return 0; + } +} + +int +extract_wim_resource_to_fd(const struct wim_lookup_table_entry *lte, + int fd, u64 size) +{ + return extract_wim_resource(lte, size, extract_wim_chunk_to_fd, &fd); +} + + +static int +sha1_chunk(const void *buf, size_t len, void *ctx) +{ + sha1_update(ctx, buf, len); + return 0; +} + +/* Calculate the SHA1 message digest of a stream. */ +int +sha1_resource(struct wim_lookup_table_entry *lte) +{ + int ret; + SHA_CTX sha_ctx; + + 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; } +/* + * 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; + 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; + } + return ret; +}