cramfs.c

在Linux2.6内核下的udev文件系统的源码

/*
 * volume_id - reads filesystem label and uuid
 *
 * Copyright (C) 2004 Kay Sievers <[e-mail]>
 *
 *	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 version 2 of the License.
 */

#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>

#include "libvolume_id.h"
#include "util.h"

struct cramfs_super {
	uint8_t		magic[4];
	uint32_t	size;
	uint32_t	flags;
	uint32_t	future;
	uint8_t		signature[16];
	struct cramfs_info {
		uint32_t	crc;
		uint32_t	edition;
		uint32_t	blocks;
		uint32_t	files;
	} PACKED info;
	uint8_t		name[16];
} PACKED;

int volume_id_probe_cramfs(struct volume_id *id, uint64_t off, uint64_t size)
{
	struct cramfs_super *cs;

	info("probing at offset 0x%llx", (unsigned long long) off);

	cs = (struct cramfs_super *) volume_id_get_buffer(id, off, 0x200);
	if (cs == NULL)
		return -1;

	if (memcmp(cs->magic, "\x45\x3d\xcd\x28", 4) == 0 || memcmp(cs->magic, "\x28\xcd\x3d\x45", 4) == 0) {
		volume_id_set_label_raw(id, cs->name, 16);
		volume_id_set_label_string(id, cs->name, 16);

		volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
		id->type = "cramfs";
		return 0;
	}

	return -1;
}