/*
 * (C) 2009 by Pablo Neira Ayuso <pablo@netfilter.org>
 *
 *      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; either version 2 of the License, or
 *      (at your option) any later version.
 *
 */
#include <stdio.h>
#include <getopt.h>
#include <stdlib.h>
#include <netinet/in.h> /* For htons */
#include <libnetfilter_conntrack/libnetfilter_conntrack.h>

#include "conntrack.h"

#ifndef IPPROTO_UDPLITE
#define IPPROTO_UDPLITE 136
#endif

enum {
	CT_UDPLITE_ORIG_SPORT		= (1 << 0),
	CT_UDPLITE_ORIG_DPORT		= (1 << 1),
	CT_UDPLITE_REPL_SPORT		= (1 << 2),
	CT_UDPLITE_REPL_DPORT		= (1 << 3),
	CT_UDPLITE_MASK_SPORT		= (1 << 4),
	CT_UDPLITE_MASK_DPORT		= (1 << 5),
	CT_UDPLITE_EXPTUPLE_SPORT	= (1 << 6),
	CT_UDPLITE_EXPTUPLE_DPORT	= (1 << 7)
};

#define UDP_OPT_MAX	11
static struct option opts[UDP_OPT_MAX] = {
	{ .name = "orig-port-src",	.has_arg = 1, .val = '1' },
	{ .name = "orig-port-dst",	.has_arg = 1, .val = '2' },
	{ .name = "reply-port-src",	.has_arg = 1, .val = '3' },
	{ .name = "reply-port-dst",	.has_arg = 1, .val = '4' },
	{ .name = "mask-port-src",	.has_arg = 1, .val = '5' },
	{ .name = "mask-port-dst",	.has_arg = 1, .val = '6' },
	{ .name = "tuple-port-src",	.has_arg = 1, .val = '7' },
	{ .name = "tuple-port-dst",	.has_arg = 1, .val = '8' },
	{ .name = "sport",		.has_arg = 1, .val = '1' },
	{ .name = "dport",		.has_arg = 1, .val = '2' },
	{0, 0, 0, 0}
};

static const char *udplite_optflags[UDP_OPT_MAX] = {
	[0] = "sport",
	[1] = "dport",
	[2] = "reply-port-src",
	[3] = "reply-port-dst",
	[4] = "mask-port-src",
	[5] = "mask-port-dst",
	[6] = "tuple-port-src",
	[7] = "tuple-port-dst"
};

static void help(void)
{
	fprintf(stdout, "  --orig-port-src\t\toriginal source port\n");
	fprintf(stdout, "  --orig-port-dst\t\toriginal destination port\n");
	fprintf(stdout, "  --reply-port-src\t\treply source port\n");
	fprintf(stdout, "  --reply-port-dst\t\treply destination port\n");
	fprintf(stdout, "  --mask-port-src\t\tmask source port\n");
	fprintf(stdout, "  --mask-port-dst\t\tmask destination port\n");
	fprintf(stdout, "  --tuple-port-src\t\texpectation tuple src port\n");
	fprintf(stdout, "  --tuple-port-src\t\texpectation tuple dst port\n");
}

static char udplite_commands_v_options[NUMBER_OF_CMD][UDP_OPT_MAX] =
{
		/* 1 2 3 4 5 6 7 8 */
/*CT_LIST*/	  {2,2,2,2,0,0,0,0},
/*CT_CREATE*/	  {3,3,3,3,0,0,0,0},
/*CT_UPDATE*/	  {2,2,2,2,0,0,0,0},
/*CT_DELETE*/	  {2,2,2,2,0,0,0,0},
/*CT_GET*/	  {3,3,3,3,0,0,0,0},
/*CT_FLUSH*/	  {0,0,0,0,0,0,0,0},
/*CT_EVENT*/	  {2,2,2,2,0,0,0,0},
/*CT_VERSION*/	  {0,0,0,0,0,0,0,0},
/*CT_HELP*/	  {0,0,0,0,0,0,0,0},
/*EXP_LIST*/	  {0,0,0,0,0,0,0,0},
/*EXP_CREATE*/	  {1,1,0,0,1,1,1,1},
/*EXP_DELETE*/	  {1,1,1,1,0,0,0,0},
/*EXP_GET*/	  {1,1,1,1,0,0,0,0},
/*EXP_FLUSH*/	  {0,0,0,0,0,0,0,0},
/*EXP_EVENT*/	  {0,0,0,0,0,0,0,0},
};

static int parse_options(char c,
			 struct nf_conntrack *ct,
			 struct nf_conntrack *exptuple,
			 struct nf_conntrack *mask,
			 unsigned int *flags)
{
	switch(c) {
	uint16_t port;
	case '1':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(ct, ATTR_ORIG_PORT_SRC, port);
		nfct_set_attr_u8(ct, ATTR_ORIG_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_ORIG_SPORT;
		break;
	case '2':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(ct, ATTR_ORIG_PORT_DST, port);
		nfct_set_attr_u8(ct, ATTR_ORIG_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_ORIG_DPORT;
		break;
	case '3':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(ct, ATTR_REPL_PORT_SRC, port);
		nfct_set_attr_u8(ct, ATTR_REPL_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_REPL_SPORT;
		break;
	case '4':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(ct, ATTR_REPL_PORT_DST, port);
		nfct_set_attr_u8(ct, ATTR_REPL_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_REPL_DPORT;
		break;
	case '5':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(mask, ATTR_ORIG_PORT_SRC, port);
		nfct_set_attr_u8(mask, ATTR_ORIG_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_MASK_SPORT;
		break;
	case '6':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(mask, ATTR_ORIG_PORT_DST, port);
		nfct_set_attr_u8(mask, ATTR_ORIG_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_MASK_DPORT;
		break;
	case '7':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(exptuple, ATTR_ORIG_PORT_SRC, port);
		nfct_set_attr_u8(exptuple, ATTR_ORIG_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_EXPTUPLE_SPORT;
		break;
	case '8':
		port = htons(atoi(optarg));
		nfct_set_attr_u16(exptuple, ATTR_ORIG_PORT_DST, port);
		nfct_set_attr_u8(exptuple, ATTR_ORIG_L4PROTO, IPPROTO_UDPLITE);
		*flags |= CT_UDPLITE_EXPTUPLE_DPORT;
		break;
	}
	return 1;
}

#define UDPLITE_VALID_FLAGS_MAX   2
static unsigned int udplite_valid_flags[UDPLITE_VALID_FLAGS_MAX] = {
       CT_UDPLITE_ORIG_SPORT | CT_UDPLITE_ORIG_DPORT,
       CT_UDPLITE_REPL_SPORT | CT_UDPLITE_REPL_DPORT,
};

static void
final_check(unsigned int flags, unsigned int cmd, struct nf_conntrack *ct)
{
	int ret, partial;

	ret = generic_opt_check(flags, UDP_OPT_MAX,
				udplite_commands_v_options[cmd],
				udplite_optflags,
				udplite_valid_flags, UDPLITE_VALID_FLAGS_MAX,
				&partial);
	if (!ret) {
		switch(partial) {
		case -1:
		case 0:
			exit_error(PARAMETER_PROBLEM, "you have to specify "
						      "`--sport' and "
						      "`--dport'");
			break;
		case 1:
			exit_error(PARAMETER_PROBLEM, "you have to specify "
						      "`--reply-src-port' and "
						      "`--reply-dst-port'");
			break;
		}
	}
}

static struct ctproto_handler udplite = {
	.name 			= "udplite",
	.protonum		= IPPROTO_UDPLITE,
	.parse_opts		= parse_options,
	.final_check		= final_check,
	.help			= help,
	.opts			= opts,
	.version		= VERSION,
};

void register_udplite(void)
{
	register_proto(&udplite);
}