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Diffstat (limited to 'Build/source/libs/zziplib/zziplib-0.13.60/zzip/fseeko.c')
-rw-r--r-- | Build/source/libs/zziplib/zziplib-0.13.60/zzip/fseeko.c | 685 |
1 files changed, 685 insertions, 0 deletions
diff --git a/Build/source/libs/zziplib/zziplib-0.13.60/zzip/fseeko.c b/Build/source/libs/zziplib/zziplib-0.13.60/zzip/fseeko.c new file mode 100644 index 00000000000..d99067a0b4f --- /dev/null +++ b/Build/source/libs/zziplib/zziplib-0.13.60/zzip/fseeko.c @@ -0,0 +1,685 @@ + +/* + * NOTE: this is part of libzzipfseeko (i.e. it is not libzzip). + * ================== + * + * These routines are fully independent from the traditional zzip + * implementation. They assume a readonly seekable stdio handle + * representing a complete zip file. The functions show how to + * parse the structure, find files and return a decoded bytestream. + * + * These routines are a bit simple and really here for documenting + * the way to access a zip file. The complexity of zip access comes + * from staggered reading of bytes and reposition of a filepointer in + * a big archive with lots of files and long compressed datastreams. + * Plus varaints of drop-in stdio replacements, obfuscation routines, + * auto fileextensions, drop-in dirent replacements, and so on... + * + * btw, we can _not_ use fgetpos/fsetpos since an fpos_t has no asserted + * relation to a linear seek value as specified in zip info headers. In + * general it is not a problem if your system has no fseeko/ftello pair + * since we can fallback to fseek/ftell which limits the zip disk size + * to 2MiBs but the zip-storable seek values are 32bit limited anyway. + * + * Author: + * Guido Draheim <guidod@gmx.de> + * + * Copyright (c) 2003,2004 Guido Draheim + * All rights reserved, + * use under the restrictions of the + * Lesser GNU General Public License + * or alternatively the restrictions + * of the Mozilla Public License 1.1 + */ + +#define _LARGEFILE_SOURCE 1 +#define _ZZIP_ENTRY_STRUCT 1 + +#include <zzip/fseeko.h> + +#include <zzip/fetch.h> +#include <zzip/__mmap.h> +#include <zzip/__fnmatch.h> + +#include <assert.h> +#include <stdlib.h> +#include <sys/stat.h> + +#if defined ZZIP_HAVE_STRING_H +#include <string.h> +#elif defined ZZIP_HAVE_STRINGS_H +#include <strings.h> +#endif + +#if defined ZZIP_HAVE_STDINT_H +#include <stdint.h> +#endif + +#if __STDC_VERSION__+0 > 199900L +#define ___ +#define ____ +#else +#define ___ { +#define ____ } +#endif + +#ifndef ZZIP_HAVE_FSEEKO +#define fseeko fseek +#define ftello ftell +#endif + +/* note that the struct zzip_entry inherits the zzip_disk_entry values + * and usually carries a copy of its values (in disk format!). To make the + * following code more readable, we use a shorthand notation for the + * upcast needed in C (not needed in C++) as "disk_(entry)". + */ +#ifdef __zzip_entry_extends_zzip_disk_entry +#define disk_(_entry_) _entry_ +#else +#define disk_(_entry_) (& (_entry_)->head) +#endif + +/* we try to round all seeks to the pagesize - since we do not use + * the sys/mmap interface we have to guess a good value here: */ +#define PAGESIZE 8192 + +/* ====================================================================== */ + +/* helper functions */ + +/** => zzip_entry_data_offset + * This functions read the correspoding struct zzip_file_header from + * the zip disk of the given "entry". The returned off_t points to the + * end of the file_header where the current fseek pointer has stopped. + * This is used to immediatly parse out any filename/extras block following + * the file_header. The return value is null on error. + */ +static zzip_off_t +zzip_entry_fread_file_header(ZZIP_ENTRY * entry, + struct zzip_file_header *file_header) +{ + if (! entry || ! file_header) + return 0; + ___ zzip_off_t offset = zzip_disk_entry_fileoffset(disk_(entry)); + if (0 > offset || offset >= entry->disksize) + return 0; + + if (fseeko(entry->diskfile, offset, SEEK_SET) == -1) return 0; + return (fread(file_header, sizeof(*file_header), 1, entry->diskfile) + ? offset + sizeof(*file_header) : 0); + ____; +} + +/** helper functions for (fseeko) zip access api + * + * This functions returns the seekval offset of the data portion of the + * file referenced by the given zzip_entry. It requires an intermediate + * check of the file_header structure (i.e. it reads it from disk). After + * this call, the contained diskfile readposition is already set to the + * data_offset returned here. On error -1 is returned. + */ +zzip_off_t +zzip_entry_data_offset(ZZIP_ENTRY * entry) +{ + struct zzip_file_header file_header; + if (! entry) + return -1; + ___ zzip_off_t offset = zzip_entry_fread_file_header(entry, &file_header); + if (! offset) + return -1; + offset += zzip_file_header_sizeof_tails(&file_header); + if (fseeko(entry->diskfile, offset, SEEK_SET) == -1) + return -1; + return offset; + ____; +} + +/** => zzip_entry_data_offset + * This function is a big helper despite its little name: in a zip file the + * encoded filenames are usually NOT zero-terminated but for common usage + * with libc we need it that way. Secondly, the filename SHOULD be present + * in the zip central directory but if not then we fallback to the filename + * given in the file_header of each compressed data portion. + */ +zzip__new__ char * +zzip_entry_strdup_name(ZZIP_ENTRY * entry) +{ + if (! entry) + return 0; + + ___ zzip_size_t len; + if ((len = zzip_disk_entry_namlen(disk_(entry)))) + { + char *name = malloc(len + 1); + if (! name) + return 0; + memcpy(name, entry->tail, len); + name[len] = '\0'; + return name; + } + ___ auto struct zzip_file_header header; + if (zzip_entry_fread_file_header(entry, &header) + && (len = zzip_file_header_namlen(&header))) + { + char *name = malloc(len + 1); + if (! name) { + return 0; + } else { + zzip_size_t n = fread(name, 1, len, entry->diskfile); + if (n != len) { + free (name); + return 0; + } + name[n] = '\0'; + return name; + } + } + return 0; + ____; + ____; +} + +static int +prescan_entry(ZZIP_ENTRY * entry) +{ + assert(entry); + ___ zzip_off_t tailsize = zzip_disk_entry_sizeof_tails(disk_(entry)); + if (tailsize + 1 > entry->tailalloc) + { + char *newtail = realloc(entry->tail, tailsize + 1); + if (! newtail) + return ENOMEM; + entry->tail = newtail; + entry->tailalloc = tailsize + 1; + } +# ifdef SIZE_MAX /* from stdint.h */ + if (tailsize > (zzip_off_t)(SIZE_MAX)) { return EFBIG; } +# endif + ___ zzip_size_t readsize = fread(entry->tail, 1, tailsize, entry->diskfile); + /* name + comment + extras */ + if ((zzip_off_t)readsize != tailsize) { + return errno; + } else { + return 0; + } ____; ____; +} + +static void +prescan_clear(ZZIP_ENTRY * entry) +{ + assert(entry); + if (entry->tail) + free(entry->tail); + entry->tail = 0; + entry->tailalloc = 0; +} + +/* ====================================================================== */ + +/** => zzip_entry_findfile + * + * This function is the first call of all the zip access functions here. + * It contains the code to find the first entry of the zip central directory. + * Here we require the stdio handle to represent a real zip file where the + * disk_trailer is _last_ in the file area, so that its position would be at + * a fixed offset from the end of the file area if not for the comment field + * allowed to be of variable length (which needs us to do a little search + * for the disk_tailer). However, in this simple implementation we disregard + * any disk_trailer info telling about multidisk archives, so we just return + * a pointer to the first entry in the zip central directory of that file. + * + * For an actual means, we are going to search backwards from the end + * of the mmaped block looking for the PK-magic signature of a + * disk_trailer. If we see one then we check the rootseek value to + * find the first disk_entry of the root central directory. If we find + * the correct PK-magic signature of a disk_entry over there then we + * assume we are done and we are going to return a pointer to that label. + * + * The return value is a pointer to the first zzip_disk_entry being checked + * to be within the bounds of the file area specified by the arguments. If + * no disk_trailer was found then null is returned, and likewise we only + * accept a disk_trailer with a seekvalue that points to a disk_entry and + * both parts have valid PK-magic parts. Beyond some sanity check we try to + * catch a common brokeness with zip archives that still allows us to find + * the start of the zip central directory. + */ +zzip__new__ ZZIP_ENTRY * +zzip_entry_findfirst(FILE * disk) +{ + if (! disk) + return 0; + if (fseeko(disk, 0, SEEK_END) == -1) + return 0; + ___ zzip_off_t disksize = ftello(disk); + if (disksize < (zzip_off_t) sizeof(struct zzip_disk_trailer)) + return 0; + /* we read out chunks of 8 KiB in the hope to match disk granularity */ + ___ zzip_off_t pagesize = PAGESIZE; /* getpagesize() */ + ___ ZZIP_ENTRY *entry = malloc(sizeof(*entry)); + if (! entry) + return 0; + ___ unsigned char *buffer = malloc(pagesize); + if (! buffer) + goto nomem; + + assert(pagesize / 2 > (zzip_off_t) sizeof(struct zzip_disk_trailer)); + /* at each step, we will fread a pagesize block which overlaps with the + * previous read by means of pagesize/2 step at the end of the while(1) */ + ___ zzip_off_t mapoffs = disksize & ~(pagesize - 1); + ___ zzip_off_t mapsize = disksize - mapoffs; + if (mapoffs && mapsize < pagesize / 2) + { + mapoffs -= pagesize / 2; + mapsize += pagesize / 2; + } + assert(mapsize < 3*8192); + while (1) + { + if (fseeko(disk, mapoffs, SEEK_SET) == -1) + goto error; + if (fread(buffer, 1, mapsize, disk) != (zzip_size_t)mapsize) + goto error; + ___ unsigned char *p = + buffer + mapsize - sizeof(struct zzip_disk_trailer); + for (; p >= buffer; p--) + { + zzip_off_t root; /* (struct zzip_disk_entry*) */ + if (zzip_disk_trailer_check_magic(p)) + { + root = zzip_disk_trailer_rootseek((struct zzip_disk_trailer *) + p); + if (root > disksize - (long) sizeof(struct zzip_disk_trailer)) + { + /* first disk_entry is after the disk_trailer? can't be! */ + struct zzip_disk_trailer *trailer = + (struct zzip_disk_trailer *) p; + zzip_off_t rootsize = zzip_disk_trailer_rootsize(trailer); + if (rootsize > mapoffs) + continue; + /* a common brokeness that can be fixed: we just assume the + * central directory was written directly before : */ + root = mapoffs - rootsize; + } + } else if (zzip_disk64_trailer_check_magic(p)) + { + struct zzip_disk64_trailer *trailer = + (struct zzip_disk64_trailer *) p; + if (sizeof(zzip_off_t) < 8) + return 0; + root = zzip_disk64_trailer_rootseek(trailer); + } else + continue; + + assert(0 <= root && root < mapsize); + if (fseeko(disk, root, SEEK_SET) == -1) + goto error; + if (fread(disk_(entry), 1, sizeof(*disk_(entry)), disk) + != sizeof(*disk_(entry))) goto error; + if (zzip_disk_entry_check_magic(entry)) + { + free(buffer); + entry->headseek = root; + entry->diskfile = disk; + entry->disksize = disksize; + if (prescan_entry(entry)) + goto nomem; + return entry; + } + } + ____; + if (! mapoffs) + break; + assert(mapsize >= pagesize / 2); + mapoffs -= pagesize / 2; /* mapsize += pagesize/2; */ + mapsize = pagesize; /* if (mapsize > pagesize) ... */ + if (disksize - mapoffs > 64 * 1024) + break; + } + error: + free(buffer); + nomem: + free(entry); + ____; + ____; + ____; + ____; + ____; + ____; + return 0; +} + +/** => zzip_entry_findfile + * + * This function takes an existing "entry" in the central root directory + * (e.g. from zzip_entry_findfirst) and moves it to point to the next entry. + * On error it returns 0, otherwise the old entry. If no further match is + * found then null is returned and the entry already free()d. If you want + * to stop searching for matches before that case then please call + * => zzip_entry_free on the cursor struct ZZIP_ENTRY. + */ +zzip__new__ ZZIP_ENTRY * +zzip_entry_findnext(ZZIP_ENTRY * _zzip_restrict entry) +{ + if (! entry) + return entry; + if (! zzip_disk_entry_check_magic(entry)) + goto err; + ___ zzip_off_t seek = + entry->headseek + zzip_disk_entry_sizeto_end(disk_(entry)); + if (seek + (zzip_off_t) sizeof(*disk_(entry)) > entry->disksize) + goto err; + + if (fseeko(entry->diskfile, seek, SEEK_SET) == -1) + goto err; + if (fread(disk_(entry), 1, sizeof(*disk_(entry)), entry->diskfile) + != sizeof(*disk_(entry))) goto err; + entry->headseek = seek; + if (! zzip_disk_entry_check_magic(entry)) + goto err; + if (prescan_entry(entry)) + goto err; + return entry; + err: + zzip_entry_free(entry); + return 0; + ____; +} + +/** => zzip_entry_findfile + * this function releases the malloc()ed areas needed for zzip_entry, the + * pointer is invalid afterwards. This function has #define synonyms of + * zzip_entry_findlast(), zzip_entry_findlastfile(), zzip_entry_findlastmatch() + */ +int +zzip_entry_free(ZZIP_ENTRY * entry) +{ + if (! entry) + return 0; + prescan_clear(entry); + free(entry); + return 1; +} + +/** search for files in the (fseeko) zip central directory + * + * This function is given a filename as an additional argument, to find the + * disk_entry matching a given filename. The compare-function is usually + * strcmp or strcasecmp or perhaps strcoll, if null then strcmp is used. + * - use null as argument for "old"-entry when searching the first + * matching entry, otherwise the last returned value if you look for other + * entries with a special "compare" function (if null then a doubled search + * is rather useless with this variant of _findfile). If no further entry is + * found then null is returned and any "old"-entry gets already free()d. + */ +zzip__new__ ZZIP_ENTRY * +zzip_entry_findfile(FILE * disk, char *filename, + ZZIP_ENTRY * _zzip_restrict entry, zzip_strcmp_fn_t compare) +{ + if (! filename || ! disk) + return 0; + if (! entry) + entry = zzip_entry_findfirst(disk); + else + entry = zzip_entry_findnext(entry); + + if (! compare) + compare = (zzip_strcmp_fn_t) (strcmp); + + for (; entry; entry = zzip_entry_findnext(entry)) + { + /* filenames within zip files are often not null-terminated! */ + char *realname = zzip_entry_strdup_name(entry); + if (! realname) + continue; + if (! compare(filename, realname)) + { + free(realname); + return entry; + } else + { + free(realname); + continue; + } + } + return 0; +} + +/** => zzip_entry_findfile + * + * This function uses a compare-function with an additional argument + * and it is called just like fnmatch(3) from POSIX.2 AD:1993), i.e. + * the argument filespec first and the ziplocal filename second with + * the integer-flags put in as third to the indirect call. If the + * platform has fnmatch available then null-compare will use that one + * and otherwise we fall back to mere strcmp, so if you need fnmatch + * searching then please provide an implementation somewhere else. + * - use null as argument for "after"-entry when searching the first + * matching entry, or the last disk_entry return-value to find the + * next entry matching the given filespec. If no further entry is + * found then null is returned and any "old"-entry gets already free()d. + */ +zzip__new__ ZZIP_ENTRY * +zzip_entry_findmatch(FILE * disk, char *filespec, + ZZIP_ENTRY * _zzip_restrict entry, + zzip_fnmatch_fn_t compare, int flags) +{ + if (! filespec || ! disk) + return 0; + if (! entry) + entry = zzip_entry_findfirst(disk); + else + entry = zzip_entry_findnext(entry); + + if (! compare) + compare = (zzip_fnmatch_fn_t) _zzip_fnmatch; + + for (; entry; entry = zzip_entry_findnext(entry)) + { + /* filenames within zip files are often not null-terminated! */ + char *realname = zzip_entry_strdup_name(entry); + if (! realname) + continue; + if (! compare(filespec, realname, flags)) + { + free(realname); + return entry; + } else + { + free(realname); + continue; + } + } + return 0; +} + +/* ====================================================================== */ + +/** + * typedef struct zzip_disk_file ZZIP_ENTRY_FILE; + */ +struct zzip_entry_file /* : zzip_file_header */ +{ + struct zzip_file_header header; /* fopen detected header */ + ZZIP_ENTRY *entry; /* fopen entry */ + zzip_off_t data; /* for stored blocks */ + zzip_size_t avail; /* memorized for checks on EOF */ + zzip_size_t compressed; /* compressed flag and datasize */ + zzip_size_t dataoff; /* offset from data start */ + z_stream zlib; /* for inflated blocks */ + unsigned char buffer[PAGESIZE]; /* work buffer for inflate algorithm */ +}; + +/** open a file within a zip disk for reading + * + * This function does take an "entry" argument and copies it (or just takes + * it over as owner) to a new ZZIP_ENTRY_FILE handle structure. That + * structure contains also a zlib buffer for decoding. This function does + * seek to the file_header of the given "entry" and validates it for the + * data buffer following it. We do also prefetch some data from the data + * buffer thereby trying to match the disk pagesize for faster access later. + * The => zzip_entry_fread will then read in chunks of pagesizes which is + * the size of the internal readahead buffer. If an error occurs then null + * is returned. + */ +zzip__new__ ZZIP_ENTRY_FILE * +zzip_entry_fopen(ZZIP_ENTRY * entry, int takeover) +{ + if (! entry) + return 0; + if (! takeover) + { + ZZIP_ENTRY *found = malloc(sizeof(*entry)); + if (! found) + return 0; + memcpy(found, entry, sizeof(*entry)); /* prescan_copy */ + found->tail = malloc(found->tailalloc); + if (! found->tail) + { free (found); return 0; } + memcpy(found->tail, entry->tail, entry->tailalloc); + entry = found; + } + ___ ZZIP_ENTRY_FILE *file = malloc(sizeof(*file)); + if (! file) + goto fail1; + file->entry = entry; + if (! zzip_entry_fread_file_header(entry, &file->header)) + goto fail2; + file->avail = zzip_file_header_usize(&file->header); + file->data = zzip_entry_data_offset(entry); + file->dataoff = 0; + + if (! file->avail || zzip_file_header_data_stored(&file->header)) + { file->compressed = 0; return file; } + + file->compressed = zzip_file_header_csize(&file->header); + file->zlib.opaque = 0; + file->zlib.zalloc = Z_NULL; + file->zlib.zfree = Z_NULL; + + ___ zzip_off_t seek = file->data; + seek += sizeof(file->buffer); + seek -= seek & (sizeof(file->buffer) - 1); + assert(file->data < seek); /* pre-read to next PAGESIZE boundary... */ + if (fseeko(file->entry->diskfile, file->data + file->dataoff, SEEK_SET) == -1) + goto fail2; + file->zlib.next_in = file->buffer; + file->zlib.avail_in = fread(file->buffer, 1, seek - file->data, + file->entry->diskfile); + file->dataoff += file->zlib.avail_in; + ____; + + if (! zzip_file_header_data_deflated(&file->header) + || inflateInit2(&file->zlib, -MAX_WBITS) != Z_OK) + goto fail2; + + return file; + fail2: + free(file); + fail1: + zzip_entry_free(entry); + return 0; + ____; +} + +/** => zzip_entry_fopen + * + * This function opens a file found by name, so it does a search into + * the zip central directory with => zzip_entry_findfile and whatever + * is found first is given to => zzip_entry_fopen + */ +zzip__new__ ZZIP_ENTRY_FILE * +zzip_entry_ffile(FILE * disk, char *filename) +{ + ZZIP_ENTRY *entry = zzip_entry_findfile(disk, filename, 0, 0); + if (! entry) + return 0; + return zzip_entry_fopen(entry, 1); +} + + +/** => zzip_entry_fopen + * + * This function reads more bytes into the output buffer specified as + * arguments. The return value is null on eof or error, the stdio-like + * interface can not distinguish between these so you need to check + * with => zzip_entry_feof for the difference. + */ +zzip_size_t +zzip_entry_fread(void *ptr, zzip_size_t sized, zzip_size_t nmemb, + ZZIP_ENTRY_FILE * file) +{ + if (! file) + return 0; + ___ zzip_size_t size = sized * nmemb; + if (! file->compressed) + { + if (size > file->avail) + size = file->avail; + if (fread(ptr, 1, size, file->entry->diskfile) != size) return 0; + file->dataoff += size; + file->avail -= size; + return size; + } + + file->zlib.avail_out = size; + file->zlib.next_out = ptr; + ___ zzip_size_t total_old = file->zlib.total_out; + while (1) + { + if (! file->zlib.avail_in) + { + size = file->compressed - file->dataoff; + if (size > sizeof(file->buffer)) + size = sizeof(file->buffer); + /* fseek (file->data + file->dataoff, file->entry->diskfile); */ + file->zlib.avail_in = fread(file->buffer, 1, size, + file->entry->diskfile); + file->zlib.next_in = file->buffer; + file->dataoff += file->zlib.avail_in; + } + if (! file->zlib.avail_in) + return 0; + + ___ int err = inflate(&file->zlib, Z_NO_FLUSH); + if (err == Z_STREAM_END) + file->avail = 0; + else if (err == Z_OK) + file->avail -= file->zlib.total_out - total_old; + else + return 0; + ____; + if (file->zlib.avail_out && ! file->zlib.avail_in) + continue; + return file->zlib.total_out - total_old; + } + ____; + ____; +} + +/** => zzip_entry_fopen + * This function releases any zlib decoder info needed for decompression + * and dumps the ZZIP_ENTRY_FILE struct then. + */ +int +zzip_entry_fclose(ZZIP_ENTRY_FILE * file) +{ + if (! file) + return 0; + if (file->compressed) + inflateEnd(&file->zlib); + zzip_entry_free(file->entry); + free(file); + return 0; +} + +/** => zzip_entry_fopen + * + * This function allows to distinguish an error from an eof condition. + * Actually, if we found an error but we did already reach eof then we + * just keep on saying that it was an eof, so the app can just continue. + */ +int +zzip_entry_feof(ZZIP_ENTRY_FILE * file) +{ + return ! file || ! file->avail; +} |