/*
 * (C) 2005-2007 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 <libnetfilter_conntrack/libnetfilter_conntrack_udp.h>

#include "conntrack.h"

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

#define UDP_NUMBER_OF_OPT       9

static const char *udp_optflags[UDP_NUMBER_OF_OPT] = {
"sport", "dport", "reply-port-src", "reply-port-dst", "mask-port-src",
"mask-port-dst", "tuple-port-src", "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 udp_commands_v_options[NUMBER_OF_CMD][UDP_NUMBER_OF_OPT] =
/* Well, it's better than "Re: Galeano vs Vargas Llosa" */
{
		/* 1 2 3 4 5 6 7 8 */
/*CT_LIST*/	  {2,2,2,2,0,0,0,0},
/*CT_CREATE*/     {1,1,1,1,0,0,0,0},
/*CT_UPDATE*/     {1,1,1,1,0,0,0,0},
/*CT_DELETE*/     {1,1,1,1,0,0,0,0},
/*CT_GET*/        {1,1,1,1,0,0,0,0},
/*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*/    {1,1,1,1,1,1,1,1},
/*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) {
		case '1':
			if (!optarg)
				break;

			nfct_set_attr_u16(ct, 
					  ATTR_ORIG_PORT_SRC, 
					  htons(atoi(optarg)));

			*flags |= UDP_ORIG_SPORT;
			break;
		case '2':
			if (!optarg)
				break;

			nfct_set_attr_u16(ct, 
					  ATTR_ORIG_PORT_DST, 
					  htons(atoi(optarg)));

			*flags |= UDP_ORIG_DPORT;
			break;
		case '3':
			if (!optarg)
				break;

			nfct_set_attr_u16(ct, 
					  ATTR_REPL_PORT_SRC, 
					  htons(atoi(optarg)));

			*flags |= UDP_REPL_SPORT;
			break;
		case '4':
			if (!optarg)
				break;

			nfct_set_attr_u16(ct, 
					  ATTR_REPL_PORT_DST, 
					  htons(atoi(optarg)));

			*flags |= UDP_REPL_DPORT;
			break;
		case '5':
			if (!optarg)
				break;

			nfct_set_attr_u16(mask,
					  ATTR_ORIG_PORT_SRC,
					  htons(atoi(optarg)));

			*flags |= UDP_MASK_SPORT;
			break;
		case '6':
			if (!optarg)
				break;

			nfct_set_attr_u16(mask, 
					  ATTR_ORIG_PORT_DST, 
					  htons(atoi(optarg)));

			*flags |= UDP_MASK_DPORT;
			break;
		case '7':
			if (!optarg)
				break;

			nfct_set_attr_u16(exptuple, 
					  ATTR_ORIG_PORT_SRC, 
					  htons(atoi(optarg)));

			*flags |= UDP_EXPTUPLE_SPORT;
			break;
		case '8':
			if (!optarg)
				break;

			nfct_set_attr_u16(exptuple, 
					  ATTR_ORIG_PORT_DST, 
					  htons(atoi(optarg)));

			*flags |= UDP_EXPTUPLE_DPORT;
			break;
	}
	return 1;
}

static void final_check(unsigned int flags,
		        unsigned int cmd,
		        struct nf_conntrack *ct)
{
	if ((flags & (UDP_ORIG_SPORT|UDP_ORIG_DPORT)) 
	    && !(flags & (UDP_REPL_SPORT|UDP_REPL_DPORT))) {
	    	nfct_set_attr_u16(ct,
				  ATTR_REPL_PORT_SRC, 
				  nfct_get_attr_u16(ct, ATTR_ORIG_PORT_DST));
		nfct_set_attr_u16(ct,
				  ATTR_REPL_PORT_DST,
				  nfct_get_attr_u16(ct, ATTR_ORIG_PORT_SRC));
		flags |= UDP_REPL_SPORT;
		flags |= UDP_REPL_DPORT;
	} else if (!(flags & (UDP_ORIG_SPORT|UDP_ORIG_DPORT))
	            && (flags & (UDP_REPL_SPORT|UDP_REPL_DPORT))) {
	    	nfct_set_attr_u16(ct,
				  ATTR_ORIG_PORT_SRC, 
				  nfct_get_attr_u16(ct, ATTR_REPL_PORT_DST));
		nfct_set_attr_u16(ct,
				  ATTR_ORIG_PORT_DST,
				  nfct_get_attr_u16(ct, ATTR_REPL_PORT_SRC));
		flags |= UDP_ORIG_SPORT;
		flags |= UDP_ORIG_DPORT;
	}

	generic_opt_check(flags, 
			  UDP_NUMBER_OF_OPT,
			  udp_commands_v_options[cmd],
			  udp_optflags);
}

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

void register_udp(void)
{
	register_proto(&udp);
}