1/* vi: set sw=4 ts=4: */
2/*
3 * Mini rpm2cpio implementation for busybox
4 *
5 * Copyright (C) 2001 by Laurence Anderson
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8 */
9#include "libbb.h"
10#include "unarchive.h"
11
12#define RPM_MAGIC "\355\253\356\333"
13#define RPM_HEADER_MAGIC "\216\255\350"
14
15struct rpm_lead {
16    unsigned char magic[4];
17    uint8_t major, minor;
18    uint16_t type;
19    uint16_t archnum;
20    char name[66];
21    uint16_t osnum;
22    uint16_t signature_type;
23    char reserved[16];
24};
25
26struct rpm_header {
27	char magic[3]; /* 3 byte magic: 0x8e 0xad 0xe8 */
28	uint8_t version; /* 1 byte version number */
29	uint32_t reserved; /* 4 bytes reserved */
30	uint32_t entries; /* Number of entries in header (4 bytes) */
31	uint32_t size; /* Size of store (4 bytes) */
32};
33
34static void skip_header(int rpm_fd)
35{
36	struct rpm_header header;
37
38	xread(rpm_fd, &header, sizeof(struct rpm_header));
39	if (strncmp((char *) &header.magic, RPM_HEADER_MAGIC, 3) != 0) {
40		bb_error_msg_and_die("invalid RPM header magic"); /* Invalid magic */
41	}
42	if (header.version != 1) {
43		bb_error_msg_and_die("unsupported RPM header version"); /* This program only supports v1 headers */
44	}
45	header.entries = ntohl(header.entries);
46	header.size = ntohl(header.size);
47	lseek (rpm_fd, 16 * header.entries, SEEK_CUR); /* Seek past index entries */
48	lseek (rpm_fd, header.size, SEEK_CUR); /* Seek past store */
49}
50
51/* No getopt required */
52int rpm2cpio_main(int argc, char **argv);
53int rpm2cpio_main(int argc, char **argv)
54{
55	struct rpm_lead lead;
56	int rpm_fd;
57	unsigned char magic[2];
58
59	if (argc == 1) {
60		rpm_fd = STDIN_FILENO;
61	} else {
62		rpm_fd = xopen(argv[1], O_RDONLY);
63	}
64
65	xread(rpm_fd, &lead, sizeof(struct rpm_lead));
66	if (strncmp((char *) &lead.magic, RPM_MAGIC, 4) != 0) {
67		bb_error_msg_and_die("invalid RPM magic"); /* Just check the magic, the rest is irrelevant */
68	}
69
70	/* Skip the signature header */
71	skip_header(rpm_fd);
72	lseek(rpm_fd, (8 - (lseek(rpm_fd, 0, SEEK_CUR) % 8)) % 8, SEEK_CUR);
73
74	/* Skip the main header */
75	skip_header(rpm_fd);
76
77	xread(rpm_fd, &magic, 2);
78	if ((magic[0] != 0x1f) || (magic[1] != 0x8b)) {
79		bb_error_msg_and_die("invalid gzip magic");
80	}
81
82	check_header_gzip_or_die(rpm_fd);
83	if (unpack_gz_stream(rpm_fd, STDOUT_FILENO) < 0) {
84		bb_error_msg("error inflating");
85	}
86
87	close(rpm_fd);
88
89	return 0;
90}
91