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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.
*
* NOTE: This is used by deb_extract to avoid calling the whole tar applet.
* Its functionality should be merged with tar to avoid duplication
*/
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libbb.h"
extern int untar(FILE *src_tar_file, const int untar_function, const char *argument)
{
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;
long i;
long next_header_offset = 0;
long uncompressed_count = 0;
size_t size;
mode_t mode;
while (fread((char *) &raw_tar_header, 1, 512, src_tar_file) == 512) {
long sum = 0;
char *dir = NULL;
if (ferror(src_tar_file) || feof(src_tar_file)) {
perror_msg("untar: ");
break;
}
uncompressed_count += 512;
/* Check header has valid magic */
if (strncmp(raw_tar_header.magic, "ustar", 5) != 0) {
/*
* FIXME, Need HELP with this
*
* This has to fail silently or it incorrectly reports errors when called from
* deb_extract.
* The problem is deb_extract decompresses the .gz file in a child process and
* untar reads from the child proccess. The child process finishes and exits,
* but fread reads 0's from the src_tar_file even though the child
* closed its handle.
*/
// error_msg("Invalid tar 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 */
size = strtol(raw_tar_header.size, NULL, 8);
parse_mode(raw_tar_header.mode, &mode);
/* start of next header is at */
next_header_offset = uncompressed_count + size;
if (size % 512 != 0) {
next_header_offset += (512 - size % 512);
}
if (untar_function & (extract_contents | extract_verbose_extract)) {
printf("%s\n", raw_tar_header.name);
}
/* extract files */
if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) {
dir = xmalloc(strlen(raw_tar_header.name) + strlen(argument) + 2);
sprintf(dir, "%s/%s", argument, raw_tar_header.name);
create_path(dir, 0777);
}
switch (raw_tar_header.typeflag ) {
case '0':
case '\0':
/* If the name ends in a '/' then assume it is
* supposed to be a directory, and fall through
*/
if (raw_tar_header.name[strlen(raw_tar_header.name)-1] != '/') {
if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) {
FILE *dst_file = wfopen(dir, "w");
copy_file_chunk(src_tar_file, dst_file, (unsigned long long) size);
uncompressed_count += size;
fclose(dst_file);
}
else if (untar_function & extract_info) {
if (strstr(raw_tar_header.name, argument) != NULL) {
copy_file_chunk(src_tar_file, stdout, (unsigned long long) size);
uncompressed_count += size;
}
}
else if (untar_function & extract_field) {
if (strstr(raw_tar_header.name, "./control") != NULL) {
char *line;
while ((line = get_line_from_file(src_tar_file)) != NULL) {
uncompressed_count += strlen(line);
if (argument == NULL) {
printf("%s",line);
}
else if (strncmp(line, argument, strlen(argument)) == 0) {
char *file_ptr;
file_ptr = strstr(line, ": ");
printf("%s", file_ptr + 2);
}
}
}
}
break;
}
case '5':
if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) {
if (create_path(dir, mode) != TRUE) {
free(dir);
perror_msg("%s: Cannot mkdir", raw_tar_header.name);
return(EXIT_FAILURE);
}
}
break;
case '1':
if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) {
if (link(raw_tar_header.linkname, raw_tar_header.name) < 0) {
free(dir);
perror_msg("%s: Cannot create hard link to '%s'", raw_tar_header.name, raw_tar_header.linkname);
return(EXIT_FAILURE);
}
}
break;
case '2':
if (untar_function & (extract_extract | extract_verbose_extract | extract_control)) {
if (symlink(raw_tar_header.linkname, raw_tar_header.name) < 0) {
free(dir);
perror_msg("%s: Cannot create symlink to '%s'", raw_tar_header.name, raw_tar_header.linkname);
return(EXIT_FAILURE);
}
}
break;
case '3':
case '4':
case '6':
// if (tarExtractSpecial( &header, extractFlag, tostdoutFlag)==FALSE)
// errorFlag=TRUE;
// break;
default:
error_msg("Unknown file type '%c' in tar file", raw_tar_header.typeflag);
free(dir);
return(EXIT_FAILURE);
}
/*
* Seek to start of next block, cant use fseek as unzip() does support it
*/
while (uncompressed_count < next_header_offset) {
if (fgetc(src_tar_file) == EOF) {
break;
}
uncompressed_count++;
}
// free(dir);
}
return(EXIT_SUCCESS);
}
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