diff options
Diffstat (limited to 'archival/libunarchive/get_header_zip.c')
| -rw-r--r-- | archival/libunarchive/get_header_zip.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/archival/libunarchive/get_header_zip.c b/archival/libunarchive/get_header_zip.c new file mode 100644 index 000000000..84f2a54f2 --- /dev/null +++ b/archival/libunarchive/get_header_zip.c @@ -0,0 +1,110 @@ +/* vi: set sw=4 ts=4: */ +/* + * get_header_zip for busybox + * + * Copyright (C) 2001 by Laurence Anderson + * + * This program 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 2 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "unarchive.h" +#include "libbb.h" + +#define ZIP_FILEHEADER_MAGIC 0x04034b50 +#define ZIP_CDS_MAGIC 0x02014b50 +#define ZIP_CDS_END_MAGIC 0x06054b50 +#define ZIP_DD_MAGIC 0x8074b50 + +file_header_t *get_header_zip(FILE *zip_stream) +{ + struct { + short version __attribute__ ((packed)); + short flags __attribute__ ((packed)); + short method __attribute__ ((packed)); + short modtime __attribute__ ((packed)); + short moddate __attribute__ ((packed)); + int crc32 __attribute__ ((packed)); + int cmpsize __attribute__ ((packed)); + int ucmpsize __attribute__ ((packed)); + short filename_len __attribute__ ((packed)); + short extra_len __attribute__ ((packed)); + } zip_header; + file_header_t *zip_entry = NULL; + int magic; + static int dd_ahead = 0; // If this is true, the we didn't know how long the last extraced file was + + fread (&magic, 4, 1, zip_stream); + archive_offset += 4; + + if (feof(zip_stream)) return(NULL); +checkmagic: + switch (magic) { + case ZIP_FILEHEADER_MAGIC: + zip_entry = xcalloc(1, sizeof(file_header_t)); + fread (&zip_header, sizeof(zip_header), 1, zip_stream); + archive_offset += sizeof(zip_header); + if (!(zip_header.method == 8 || zip_header.method == 0)) { printf("Unsupported compression method %d\n", zip_header.method); return(NULL); } + zip_entry->name = calloc(zip_header.filename_len + 1, sizeof(char)); + fread (zip_entry->name, sizeof(char), zip_header.filename_len, zip_stream); + archive_offset += zip_header.filename_len; + seek_sub_file(zip_stream, zip_header.extra_len); + zip_entry->size = zip_header.cmpsize; + if (zip_header.method == 8) zip_entry->extract_func = &inflate; + zip_entry->mode = S_IFREG | 0777; + // Time/Date? + if (*(zip_entry->name + strlen(zip_entry->name) - 1) == '/') { // Files that end in a / are directories + zip_entry->mode ^= S_IFREG; + zip_entry->mode |= S_IFDIR; + *(zip_entry->name + strlen(zip_entry->name) - 1) = '\0'; // Remove trailing / so unarchive doesn't get confused + } + //printf("cmpsize: %d, ucmpsize: %d, method: %d\n", zip_header.cmpsize, zip_header.ucmpsize, zip_header.method); + if (zip_header.flags & 0x8) { // crc32, and sizes are in the data description _after_ the file + if (zip_header.cmpsize == 0) dd_ahead = 1; // As we don't know how long this file it is difficult to skip! but it is compressed, so normally its ok + if (zip_header.ucmpsize != 0) dd_ahead = 2; // Humm... we would otherwise skip this twice - not good! + } + break; + case ZIP_CDS_MAGIC: /* FALLTHRU */ + case ZIP_CDS_END_MAGIC: + return(NULL); + break; + case ZIP_DD_MAGIC: { + int cmpsize; + seek_sub_file(zip_stream, 4); // Skip crc32 + fread(&cmpsize, 4, 1, zip_stream); + archive_offset += 4; + if (dd_ahead == 1) archive_offset += cmpsize; + seek_sub_file(zip_stream, 4); // Skip uncompressed size + dd_ahead = 0; + return (get_header_zip(zip_stream)); + break; } + default: + if (!dd_ahead) error_msg("Invalid magic (%#x): Trying to skip junk", magic); + dd_ahead = 0; + while (!feof(zip_stream)) { + int tmpmagic; + tmpmagic = fgetc(zip_stream); + archive_offset++; + magic = ((magic >> 8) & 0x00ffffff) | ((tmpmagic << 24) & 0xff000000); + if (magic == ZIP_FILEHEADER_MAGIC || magic == ZIP_CDS_MAGIC || magic == ZIP_CDS_END_MAGIC) goto checkmagic; + } + error_msg("End of archive reached: Bad archive"); + return(NULL); + } + //if (archive_offset != ftell(zip_stream)) printf("Archive offset out of sync (%d,%d)\n", (int) archive_offset, (int) ftell(zip_stream)); + return(zip_entry); +} |