hush/archival/rpm2cpio.c
Denys Vlasenko e6c483ec30 rpm2cpio: code shrink
function                                             old     new   delta
skip_header                                           94      92      -2
rpm2cpio_main                                        177     174      -3
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-5)               Total: -5 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2009-08-28 21:15:24 +02:00

111 lines
2.7 KiB
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 tarball for details.
*/
#include "libbb.h"
#include "unarchive.h"
#define RPM_MAGIC 0xedabeedb
#define RPM_MAGIC_STR "\355\253\356\333"
struct rpm_lead {
uint32_t magic;
uint8_t major, minor;
uint16_t type;
uint16_t archnum;
char name[66];
uint16_t osnum;
uint16_t signature_type;
char reserved[16];
};
#define RPM_HEADER_MAGICnVER 0x8eade801
#define RPM_HEADER_MAGIC_STR "\216\255\350"
struct rpm_header {
uint32_t magic_and_ver; /* 3 byte magic: 0x8e 0xad 0xe8; 1 byte version */
uint32_t reserved; /* 4 bytes reserved */
uint32_t entries; /* Number of entries in header (4 bytes) */
uint32_t size; /* Size of store (4 bytes) */
};
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;
unsigned char magic[2];
IF_DESKTOP(long long) int FAST_FUNC (*unpack)(int src_fd, int dst_fd);
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_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, (8 - pos) & 7);
/* Skip the main header */
skip_header();
xread(rpm_fd, &magic, 2);
unpack = unpack_gz_stream;
if (magic[0] != 0x1f || magic[1] != 0x8b) {
if (!ENABLE_FEATURE_SEAMLESS_BZ2
|| magic[0] != 'B' || magic[1] != 'Z'
) {
bb_error_msg_and_die("invalid gzip"
IF_FEATURE_SEAMLESS_BZ2("/bzip2")
" magic");
}
unpack = unpack_bz2_stream;
}
if (unpack(rpm_fd, STDOUT_FILENO) < 0) {
bb_error_msg_and_die("error unpacking");
}
if (ENABLE_FEATURE_CLEAN_UP) {
close(rpm_fd);
}
return 0;
}