extensions/libct_proto_udp.c

/*
 * (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 "conntrack.h"

enum {
	CT_UDP_ORIG_SPORT =	(1 << 0),
	CT_UDP_ORIG_DPORT =	(1 << 1),
	CT_UDP_REPL_SPORT =	(1 << 2),
	CT_UDP_REPL_DPORT =	(1 << 3),
	CT_UDP_MASK_SPORT =	(1 << 4),
	CT_UDP_MASK_DPORT =	(1 << 5),
	CT_UDP_EXPTUPLE_SPORT =	(1 << 6),
	CT_UDP_EXPTUPLE_DPORT =	(1 << 7)
};

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*/     {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_UDP);
			*flags |= CT_UDP_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_UDP);
			*flags |= CT_UDP_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_UDP);
			*flags |= CT_UDP_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_UDP);
			*flags |= CT_UDP_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_UDP);
			*flags |= CT_UDP_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_UDP);
			*flags |= CT_UDP_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_UDP);
			*flags |= CT_UDP_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_UDP);
			*flags |= CT_UDP_EXPTUPLE_DPORT;
			break;
	}
	return 1;
}

#define UDP_VALID_FLAGS_MAX   2
static unsigned int udp_valid_flags[UDP_VALID_FLAGS_MAX] = {
       CT_UDP_ORIG_SPORT | CT_UDP_ORIG_DPORT,
       CT_UDP_REPL_SPORT | CT_UDP_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_NUMBER_OF_OPT,
				udp_commands_v_options[cmd], udp_optflags,
				udp_valid_flags, UDP_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 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);
}