/* $Id: squashfs.c,v 1.1.1.1 2009/02/21 21:25:20 khorben Exp $ */
/* Parts Copyright (c) 2007 Matthias Wenzel, matthias /at/ mazzoo /dot/ de,
 * Parts Copyright (c) 2002-2007 Phillip Lougher, phillip /at/
 * lougher.demon.co /dot/ uk
 * Parts Copyright (c) 2008 khorben of UberWall */
/* 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */



#include <time.h>
#include "plugin.h"


/* squashfs */
/* public */
/* variables */
/* magic */
static unsigned char sig1[] = "sqsh";
static unsigned char sig2[] = "hsqs";

static PluginMagic squashfs_magic[] =
{
	{ 4, 0, sig1,	sizeof(sig1)-1	},
	{ 4, 0, sig2,	sizeof(sig2)-1	},
	{ 0, 0, NULL,	0		}
};


/* functions */
static int squashfs_callback(PluginHelper * ph, int signature, FILE * fp);


/* plugin */
Plugin plugin =
{
	PT_ARCHIVE | PT_COMPRESSION,
	"SQUASHFS",
	squashfs_magic,
	squashfs_callback
};


/* private */
/* types */
typedef long long squashfs_inode_t;

#pragma pack(1)
struct squashfs_super_block
{
	unsigned int s_magic;
	unsigned int inodes;
	unsigned int bytes_used_2;
	unsigned int uid_start_2;
	unsigned int guid_start_2;
	unsigned int inode_table_start_2;
	unsigned int directory_table_start_2;
	unsigned int s_major:16;
	unsigned int s_minor:16;
	unsigned int block_size_1:16;
	unsigned int block_log:16;
	unsigned int flags:8;
	unsigned int no_uids:8;
	unsigned int no_guids:8;
	unsigned int mkfs_time /* time of filesystem creation */;
	squashfs_inode_t root_inode;
	unsigned int block_size;
	unsigned int fragments;
	unsigned int fragment_table_start_2;
	long long bytes_used;
	long long uid_start;
	long long guid_start;
	long long inode_table_start;
	long long directory_table_start;
	long long fragment_table_start;
	long long lookup_table_start;
};
#pragma pack()


/* functions */
/* squashfs_callback */
static void _callback_endian_little(struct squashfs_super_block * buf);
static void _callback_endian_big(struct squashfs_super_block * buf);
static int _callback_version(PluginHelper * ph, unsigned int major,
		unsigned int minor);
static int _callback_time(PluginHelper * ph, time_t mtime);

static int squashfs_callback(PluginHelper * ph, int signature, FILE * fp)
{
	int score = 0;
	struct squashfs_super_block buf;

	if(fread(&buf, sizeof(buf), 1, fp) != 1)
		return -1;
	if(signature == 0)
	{
		score += 100;
		ph->printf(ph, "%s", "big endian");
		_callback_endian_big(&buf);
	}
	else if(signature == 1)
	{
		score += 100;
		ph->printf(ph, "%s", "big endian");
		_callback_endian_little(&buf);
	}
	score += _callback_version(ph, buf.s_major, buf.s_minor);
	score += _callback_time(ph, buf.mkfs_time);
	ph->printf(ph, ", block size %d", buf.block_size);
	ph->printf(ph, "\n");
	return score / 3;
}

static void _callback_endian_little(struct squashfs_super_block * buf)
{
	buf->s_major = htol16(buf->s_major);
	buf->s_minor = htol16(buf->s_minor);
	buf->mkfs_time = htol32(buf->mkfs_time);
	buf->block_size = htol32(buf->block_size);
}

static void _callback_endian_big(struct squashfs_super_block * buf)
{
	buf->s_major = htob16(buf->s_major);
	buf->s_minor = htob16(buf->s_minor);
	buf->mkfs_time = htob32(buf->mkfs_time);
	buf->block_size = htob32(buf->block_size);
}

static int _callback_version(PluginHelper * ph, unsigned int major,
		unsigned int minor)
{
	ph->printf(ph, ", version %d.%d", major, minor);
	return major <= 5 ? 100 : 0;
}

static int _callback_time(PluginHelper * ph, time_t mtime)
{
	struct tm tm;
	char tmp[22] = "";

	if(mtime == 0)
		return 0;
	if(gmtime_r(&mtime, &tm) == NULL || strftime(tmp, sizeof(tmp),
				", %d/%m/%Y %H:%M:%S", &tm) == 0)
	{
		ph->printf(ph, "%s", ", unknown date");
		return 0;
	}
	ph->printf(ph, "%s", tmp);
	/* between Wed May  1 00:00:00 CEST 1996 and now */
	return mtime > 830901600 && mtime < time(NULL) ? 100 : 0;
}