busybox/archival/rpm2cpio.c
2001-11-12 16:44:55 +00:00

91 lines
2.9 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini rpm2cpio implementation 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 "busybox.h"
#include <netinet/in.h> /* For ntohl & htonl function */
#include <string.h>
#define RPM_MAGIC "\355\253\356\333"
#define RPM_HEADER_MAGIC "\216\255\350"
struct rpm_lead {
unsigned char magic[4];
u_int8_t major, minor;
u_int16_t type;
u_int16_t archnum;
char name[66];
u_int16_t osnum;
u_int16_t signature_type;
char reserved[16];
};
struct rpm_header {
char magic[3]; /* 3 byte magic: 0x8e 0xad 0xe8 */
u_int8_t version; /* 1 byte version number */
u_int32_t reserved; /* 4 bytes reserved */
u_int32_t entries; /* Number of entries in header (4 bytes) */
u_int32_t size; /* Size of store (4 bytes) */
};
void skip_header(FILE *rpmfile)
{
struct rpm_header header;
fread(&header, sizeof(struct rpm_header), 1, rpmfile);
if (strncmp((char *) &header.magic, RPM_HEADER_MAGIC, 3) != 0) error_msg_and_die("Invalid RPM header magic"); /* Invalid magic */
if (header.version != 1) error_msg_and_die("Unsupported RPM header version"); /* This program only supports v1 headers */
header.entries = ntohl(header.entries);
header.size = ntohl(header.size);
fseek (rpmfile, 16 * header.entries, SEEK_CUR); /* Seek past index entries */
fseek (rpmfile, header.size, SEEK_CUR); /* Seek past store */
}
/* No getopt required */
extern int rpm2cpio_main(int argc, char **argv)
{
struct rpm_lead lead;
int gunzip_pid;
FILE *rpmfile, *cpiofile;
if (argc == 1) {
rpmfile = stdin;
} else {
rpmfile = xfopen(argv[1], "r");
/* set the buffer size */
setvbuf(rpmfile, NULL, _IOFBF, 0x8000);
}
fread (&lead, sizeof(struct rpm_lead), 1, rpmfile);
if (strncmp((char *) &lead.magic, RPM_MAGIC, 4) != 0) error_msg_and_die("Invalid RPM magic"); /* Just check the magic, the rest is irrelevant */
/* Skip the signature header */
skip_header(rpmfile);
fseek(rpmfile, (8 - (ftell(rpmfile) % 8)) % 8, SEEK_CUR); /* Pad to 8 byte boundary */
/* Skip the main header */
skip_header(rpmfile);
cpiofile = gz_open(rpmfile, &gunzip_pid);
copyfd(fileno(cpiofile), fileno(stdout));
gz_close(gunzip_pid);
fclose(rpmfile);
return 0;
}