hush/archival/rpm2cpio.c
Denys Vlasenko 26b6ccf340 *: simplify checks for gz/bz2/xz magic
function                                             old     new   delta
send_tree                                            360     355      -5
rpm2cpio_main                                        249     220     -29
setup_unzip_on_fd                                    150     118     -32
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-66)             Total: -66 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-06-02 14:14:48 +02:00

116 lines
2.9 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"
#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 0
/* This works, but doesn't report uncompress errors (they happen in child) */
setup_unzip_on_fd(rpm_fd /*fail_if_not_detected: 1*/);
if (bb_copyfd_eof(rpm_fd, STDOUT_FILENO) < 0)
bb_error_msg_and_die("error unpacking");
#else
/* BLOAT */
{
union {
uint8_t b[4];
uint16_t b16[2];
uint32_t b32[1];
} magic;
IF_DESKTOP(long long) int FAST_FUNC (*unpack)(int src_fd, int dst_fd);
xread(rpm_fd, magic.b16, sizeof(magic.b16));
if (magic.b16[0] == GZIP_MAGIC) {
unpack = unpack_gz_stream;
} else
if (ENABLE_FEATURE_SEAMLESS_BZ2
&& magic.b16[0] == BZIP2_MAGIC
) {
unpack = unpack_bz2_stream;
} else
if (ENABLE_FEATURE_SEAMLESS_XZ
&& magic.b16[0] == XZ_MAGIC1
) {
/* .xz signature: 0xfd, '7', 'z', 'X', 'Z', 0x00 */
/* More info at: http://tukaani.org/xz/xz-file-format.txt */
xread(rpm_fd, magic.b32, sizeof(magic.b32));
if (magic.b32[0] != XZ_MAGIC2)
goto no_magic;
/* unpack_xz_stream wants fd at position 0 */
xlseek(rpm_fd, -6, SEEK_CUR);
unpack = unpack_xz_stream;
} else {
no_magic:
bb_error_msg_and_die("no gzip"
IF_FEATURE_SEAMLESS_BZ2("/bzip2")
IF_FEATURE_SEAMLESS_XZ("/xz")
" magic");
}
if (unpack(rpm_fd, STDOUT_FILENO) < 0)
bb_error_msg_and_die("error unpacking");
}
#endif
if (ENABLE_FEATURE_CLEAN_UP) {
close(rpm_fd);
}
return 0;
}