busybox/archival/rpm2cpio.c

/* vi: set sw=4 ts=4: */
/*
 * Mini rpm2cpio implementation for busybox
 *
 * Copyright (C) 2001 by Laurence Anderson
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//config:config RPM2CPIO
//config:	bool "rpm2cpio (20 kb)"
//config:	default y
//config:	help
//config:	Converts a RPM file into a CPIO archive.

//applet:IF_RPM2CPIO(APPLET(rpm2cpio, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_RPM2CPIO) += rpm2cpio.o

//usage:#define rpm2cpio_trivial_usage
//usage:       "package.rpm"
//usage:#define rpm2cpio_full_usage "\n\n"
//usage:       "Output a cpio archive of the rpm file"

#include "libbb.h"
#include "bb_archive.h"
#include "rpm.h"

enum { rpm_fd = STDIN_FILENO };

static unsigned skip_header(void)
{
	struct rpm_header header;
	unsigned len;

	xread(rpm_fd, &header, sizeof(header));
//	if (strncmp((char *) &header.magic, RPM_HEADER_MAGIC_STR, 3) != 0) {
//		bb_error_msg_and_die("invalid RPM header magic");
//	}
//	if (header.version != 1) {
//		bb_error_msg_and_die("unsupported RPM header version");
//	}
	if (header.magic_and_ver != htonl(RPM_HEADER_MAGICnVER)) {
		bb_error_msg_and_die("invalid RPM header magic or unsupported version");
		// ": %x != %x", header.magic_and_ver, htonl(RPM_HEADER_MAGICnVER));
	}

	/* Seek past index entries, and past store */
	len = 16 * ntohl(header.entries) + ntohl(header.size);
	seek_by_jump(rpm_fd, len);

	return sizeof(header) + len;
}

/* No getopt required */
int rpm2cpio_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
{
	struct rpm_lead lead;
	unsigned pos;

	if (argv[1]) {
		xmove_fd(xopen(argv[1], O_RDONLY), rpm_fd);
	}
	xread(rpm_fd, &lead, sizeof(lead));

	/* Just check the magic, the rest is irrelevant */
	if (lead.magic != htonl(RPM_LEAD_MAGIC)) {
		bb_error_msg_and_die("invalid RPM magic");
	}

	/* Skip the signature header, align to 8 bytes */
	pos = skip_header();
	seek_by_jump(rpm_fd, (-(int)pos) & 7);

	/* Skip the main header */
	skip_header();

	//if (SEAMLESS_COMPRESSION)
	//	/* We need to know whether child (gzip/bzip/etc) exits abnormally */
	//	signal(SIGCHLD, check_errors_in_children);

	/* This works, but doesn't report uncompress errors (they happen in child) */
	setup_unzip_on_fd(rpm_fd, /*fail_if_not_compressed:*/ 1);
	if (bb_copyfd_eof(rpm_fd, STDOUT_FILENO) < 0)
		bb_error_msg_and_die("error unpacking");

	if (ENABLE_FEATURE_CLEAN_UP) {
		close(rpm_fd);
	}

	if (SEAMLESS_COMPRESSION) {
		check_errors_in_children(0);
		return bb_got_signal;
	}
	return EXIT_SUCCESS;
}