busybox/archival/libunarchive/get_header_ar.c
Glenn L McGrath 91e464632b Fix bug when handling debian packages.
If we read the contents of compressed files within the ar archive,
e.g. control.tar.gz, then file position gets all out of whack, so
it has to be reset before reading thenext header.
2003-07-31 01:53:50 +00:00

125 lines
4.2 KiB
C

/*
* 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 <unistd.h>
#include "unarchive.h"
#include "libbb.h"
extern char get_header_ar(archive_handle_t *archive_handle)
{
file_header_t *typed = archive_handle->file_header;
union {
char raw[60];
struct {
char name[16];
char date[12];
char uid[6];
char gid[6];
char mode[8];
char size[10];
char magic[2];
} formated;
} ar;
#ifdef CONFIG_FEATURE_AR_LONG_FILENAMES
static char *ar_long_names;
static unsigned int ar_long_name_size;
#endif
/* dont use bb_xread as we want to handle the error ourself */
if (read(archive_handle->src_fd, ar.raw, 60) != 60) {
/* End Of File */
return(EXIT_FAILURE);
}
/* Some ar entries have a trailing '\n' after the previous data entry */
if (ar.raw[0] == '\n') {
/* fix up the header, we started reading 1 byte too early */
memmove(ar.raw, &ar.raw[1], 59);
ar.raw[59] = bb_xread_char(archive_handle->src_fd);
archive_handle->offset++;
}
archive_handle->offset += 60;
/* align the headers based on the header magic */
if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
bb_error_msg_and_die("Invalid ar header");
}
typed->mode = strtol(ar.formated.mode, NULL, 8);
typed->mtime = atoi(ar.formated.date);
typed->uid = atoi(ar.formated.uid);
typed->gid = atoi(ar.formated.gid);
typed->size = atoi(ar.formated.size);
/* long filenames have '/' as the first character */
if (ar.formated.name[0] == '/') {
#ifdef CONFIG_FEATURE_AR_LONG_FILENAMES
if (ar.formated.name[1] == '/') {
/* If the second char is a '/' then this entries data section
* stores long filename for multiple entries, they are stored
* in static variable long_names for use in future entries */
ar_long_name_size = typed->size;
ar_long_names = xmalloc(ar_long_name_size);
bb_xread_all(archive_handle->src_fd, ar_long_names, ar_long_name_size);
archive_handle->offset += ar_long_name_size;
/* This ar entries data section only contained filenames for other records
* they are stored in the static ar_long_names for future reference */
return (get_header_ar(archive_handle)); /* Return next header */
} else if (ar.formated.name[1] == ' ') {
/* This is the index of symbols in the file for compilers */
data_skip(archive_handle);
return (get_header_ar(archive_handle)); /* Return next header */
} else {
/* The number after the '/' indicates the offset in the ar data section
(saved in variable long_name) that conatains the real filename */
const unsigned int long_offset = atoi(&ar.formated.name[1]);
if (long_offset >= ar_long_name_size) {
bb_error_msg_and_die("Cant resolve long filename");
}
typed->name = bb_xstrdup(ar_long_names + long_offset);
}
#else
bb_error_msg_and_die("long filenames not supported");
#endif
} else {
/* short filenames */
typed->name = bb_xstrndup(ar.formated.name, 16);
}
typed->name[strcspn(typed->name, " /")] = '\0';
if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
archive_handle->action_header(typed);
if (archive_handle->sub_archive) {
while (archive_handle->action_data_subarchive(archive_handle->sub_archive) == EXIT_SUCCESS);
} else {
archive_handle->action_data(archive_handle);
}
} else {
data_skip(archive_handle);
}
archive_handle->offset += typed->size;
/* Set the file pointer to the correct spot, we may have been reading a compressed file */
lseek(archive_handle->src_fd, archive_handle->offset, SEEK_SET);
return(EXIT_SUCCESS);
}