| /* |
| * 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 Library 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" |
| |
| file_header_t *get_header_tar(FILE *tar_stream) |
| { |
| union { |
| unsigned char raw[512]; |
| struct { |
| char name[100]; /* 0-99 */ |
| char mode[8]; /* 100-107 */ |
| char uid[8]; /* 108-115 */ |
| char gid[8]; /* 116-123 */ |
| char size[12]; /* 124-135 */ |
| char mtime[12]; /* 136-147 */ |
| char chksum[8]; /* 148-155 */ |
| char typeflag; /* 156-156 */ |
| char linkname[100]; /* 157-256 */ |
| char magic[6]; /* 257-262 */ |
| char version[2]; /* 263-264 */ |
| char uname[32]; /* 265-296 */ |
| char gname[32]; /* 297-328 */ |
| char devmajor[8]; /* 329-336 */ |
| char devminor[8]; /* 337-344 */ |
| char prefix[155]; /* 345-499 */ |
| char padding[12]; /* 500-512 */ |
| } formated; |
| } tar; |
| file_header_t *tar_entry = NULL; |
| long sum = 0; |
| long i; |
| |
| if (archive_offset % 512 != 0) { |
| seek_sub_file(tar_stream, 512 - (archive_offset % 512)); |
| } |
| |
| if (fread(tar.raw, 1, 512, tar_stream) != 512) { |
| /* Unfortunatly its common for tar files to have all sorts of |
| * trailing garbage, fail silently */ |
| // error_msg("Couldnt read header"); |
| return(NULL); |
| } |
| archive_offset += 512; |
| |
| /* Check header has valid magic, "ustar" is for the proper tar |
| * 0's are for the old tar format |
| */ |
| if (strncmp(tar.formated.magic, "ustar", 5) != 0) { |
| #ifdef CONFIG_FEATURE_TAR_OLD_FORMAT |
| if (strncmp(tar.formated.magic, "\0\0\0\0\0", 5) != 0) |
| #endif |
| return(NULL); |
| } |
| |
| /* If there is no filename its an empty header, skip it */ |
| if (tar.formated.name[0] == 0) { |
| return(NULL); |
| } |
| |
| /* Do checksum on headers */ |
| for (i = 0; i < 148 ; i++) { |
| sum += tar.raw[i]; |
| } |
| sum += ' ' * 8; |
| for (i = 156; i < 512 ; i++) { |
| sum += tar.raw[i]; |
| } |
| if (sum != strtol(tar.formated.chksum, NULL, 8)) { |
| error_msg("Invalid tar header checksum"); |
| return(NULL); |
| } |
| |
| /* convert to type'ed variables */ |
| tar_entry = xcalloc(1, sizeof(file_header_t)); |
| if (tar.formated.prefix[0] == 0) { |
| tar_entry->name = xstrdup(tar.formated.name); |
| } else { |
| tar_entry->name = concat_path_file(tar.formated.prefix, tar.formated.name); |
| } |
| |
| tar_entry->mode = strtol(tar.formated.mode, NULL, 8); |
| #ifdef CONFIG_FEATURE_TAR_OLD_FORMAT |
| switch (tar.formated.typeflag) { |
| case 0: |
| tar_entry->mode |= S_IFREG; |
| break; |
| case 1: |
| error_msg("internal hard link not handled\n"); |
| break; |
| case 2: |
| tar_entry->mode |= S_IFLNK; |
| break; |
| case 3: |
| tar_entry->mode |= S_IFCHR; |
| break; |
| case 4: |
| tar_entry->mode |= S_IFBLK; |
| break; |
| case 5: |
| tar_entry->mode |= S_IFDIR; |
| break; |
| case 6: |
| tar_entry->mode |= S_IFIFO; |
| break; |
| } |
| #endif |
| tar_entry->uid = strtol(tar.formated.uid, NULL, 8); |
| tar_entry->gid = strtol(tar.formated.gid, NULL, 8); |
| tar_entry->size = strtol(tar.formated.size, NULL, 8); |
| tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8); |
| tar_entry->link_name = strlen(tar.formated.linkname) ? |
| xstrdup(tar.formated.linkname) : NULL; |
| tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) + |
| strtol(tar.formated.devminor, NULL, 8); |
| |
| return(tar_entry); |
| } |
| |