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/*
* 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 <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libbb.h"
file_headers_t *get_tar_headers(FILE *tar_stream)
{
typedef struct raw_tar_header {
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 */
} raw_tar_header_t;
raw_tar_header_t raw_tar_header;
unsigned char *temp = (unsigned char *) &raw_tar_header;
file_headers_t *tar_headers_list = (file_headers_t *) calloc(1, sizeof(file_headers_t));
file_headers_t *tar_entry;
long i;
long next_header_offset = 0;
long current_offset = 0;
while (fread((char *) &raw_tar_header, 1, 512, tar_stream) == 512) {
long sum = 0;
current_offset += 512;
/* Check header has valid magic, unfortunately some tar files
* have empty (0'ed) tar entries at the end, which will
* cause this to fail, so fail silently for now
*/
if (strncmp(raw_tar_header.magic, "ustar", 5) != 0) {
// error_msg("invalid magic, [%s]\n", raw_tar_header.magic);
break;
}
/* Do checksum on headers */
for (i = 0; i < 148 ; i++) {
sum += temp[i];
}
sum += ' ' * 8;
for (i = 156; i < 512 ; i++) {
sum += temp[i];
}
if (sum != strtol(raw_tar_header.chksum, NULL, 8)) {
error_msg("Invalid tar header checksum");
break;
}
/* convert to type'ed variables */
tar_entry = xcalloc(1, sizeof(file_headers_t));
tar_entry->name = xstrdup(raw_tar_header.name);
tar_entry->offset = (off_t) current_offset;
parse_mode(raw_tar_header.mode, &tar_entry->mode);
tar_entry->uid = strtol(raw_tar_header.uid, NULL, 8);
tar_entry->gid = strtol(raw_tar_header.gid, NULL, 8);
tar_entry->size = strtol(raw_tar_header.size, NULL, 8);
tar_entry->mtime = strtol(raw_tar_header.mtime, NULL, 8);
tar_entry->link_name = xstrdup(raw_tar_header.linkname);
// tar_entry->devmajor = strtol(rawHeader->devmajor, NULL, 8);
// tar_entry->devminor = strtol(rawHeader->devminor, NULL, 8);
tar_headers_list = append_archive_list(tar_headers_list, tar_entry);
/* start of next header is at */
next_header_offset = current_offset + tar_entry->size;
if (tar_entry->size % 512 != 0) {
next_header_offset += (512 - tar_entry->size % 512);
}
/*
* Seek to start of next block, cant use fseek as unzip() does support it
*/
while (current_offset < next_header_offset) {
if (fgetc(tar_stream) == EOF) {
break;
}
current_offset++;
}
}
return(tar_headers_list);
}
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