extensions/libipt_dccp.c - maze/iptables - Git at Google

 /* Shared library add-on to iptables for DCCP matching
  *
  * (C) 2005 by Harald Welte <laforge@netfilter.org>
  *
  * This program is distributed under the terms of GNU GPL v2, 1991
  *
  */
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <getopt.h>
 #include <netdb.h>
 #include <ctype.h>

 #include <iptables.h>
 #include <linux/dccp.h>
 #include <linux/netfilter_ipv4/ip_tables.h>
 #include <linux/netfilter_ipv4/ipt_dccp.h>

 #if 0
 #define DEBUGP(format, first...) printf(format, ##first)
 #define static
 #else
 #define DEBUGP(format, fist...)
 #endif

 /* Initialize the match. */
 static void
 init(struct ipt_entry_match *m,
      unsigned int *nfcache)
 {
 	struct ipt_dccp_info *einfo = (struct ipt_dccp_info *)m->data;

 	memset(einfo, 0, sizeof(struct ipt_dccp_info));
 }

 static void help(void)
 {
 	printf(
 "DCCP match v%s options\n"
 " --source-port [!] port[:port]                          match source port(s)\n"
 " --sport ...\n"
 " --destination-port [!] port[:port]                     match destination port(s)\n"
 " --dport ...\n"
 ,
 	IPTABLES_VERSION);
 }

 static struct option opts[] = {
 	{ .name = "source-port", .has_arg = 1, .flag = 0, .val = '1' },
 	{ .name = "sport", .has_arg = 1, .flag = 0, .val = '1' },
 	{ .name = "destination-port", .has_arg = 1, .flag = 0, .val = '2' },
 	{ .name = "dport", .has_arg = 1, .flag = 0, .val = '2' },
 	{ .name = "dccp-types", .has_arg = 1, .flag = 0, .val = '3' },
 	{ .name = "dccp-option", .has_arg = 1, .flag = 0, .val = '4' },
 	{ .name = 0 }
 };

 static int
 service_to_port(const char *name)
 {
 	struct servent *service;

 	if ((service = getservbyname(name, "dccp")) != NULL)
 		return ntohs((unsigned short) service->s_port);

 	return -1;
 }

 static u_int16_t
 parse_dccp_port(const char *port)
 {
 	unsigned int portnum;

 	DEBUGP("%s\n", port);
 	if (string_to_number(port, 0, 65535, &portnum) != -1 ||
 	    (portnum = service_to_port(port)) != -1)
 		return (u_int16_t)portnum;

 	exit_error(PARAMETER_PROBLEM,
 		   "invalid DCCP port/service `%s' specified", port);
 }

 static void
 parse_dccp_ports(const char *portstring,
 		 u_int16_t *ports)
 {
 	char *buffer;
 	char *cp;

 	buffer = strdup(portstring);
 	DEBUGP("%s\n", portstring);
 	if ((cp = strchr(buffer, ':')) == NULL) {
 		ports[0] = ports[1] = parse_dccp_port(buffer);
 	}
 	else {
 		*cp = '\0';
 		cp++;

 		ports[0] = buffer[0] ? parse_dccp_port(buffer) : 0;
 		ports[1] = cp[0] ? parse_dccp_port(cp) : 0xFFFF;

 		if (ports[0] > ports[1])
 			exit_error(PARAMETER_PROBLEM,
 				   "invalid portrange (min > max)");
 	}
 	free(buffer);
 }

 static char *dccp_pkt_types[] = {
 	[DCCP_PKT_REQUEST] 	= "REQUEST",
 	[DCCP_PKT_RESPONSE]	= "RESPONSE",
 	[DCCP_PKT_DATA]		= "DATA",
 	[DCCP_PKT_ACK]		= "ACK",
 	[DCCP_PKT_DATAACK]	= "DATAACK",
 	[DCCP_PKT_CLOSEREQ]	= "CLOSEREQ",
 	[DCCP_PKT_CLOSE]	= "CLOSE",
 	[DCCP_PKT_RESET]	= "RESET",
 	[DCCP_PKT_SYNC]		= "SYNC",
 	[DCCP_PKT_SYNCACK]	= "SYNCACK",
 	[DCCP_PKT_INVALID]	= "INVALID",
 };

 static u_int16_t
 parse_dccp_types(const char *typestring)
 {
 	u_int16_t typemask = 0;
 	char *ptr, *buffer;

 	buffer = strdup(typestring);

 	for (ptr = strtok(buffer, ","); ptr; ptr = strtok(NULL, ",")) {
 		unsigned int i;
 		for (i = 0; i < sizeof(dccp_pkt_types)/sizeof(char *); i++) {
 			if (!strcasecmp(dccp_pkt_types[i], ptr)) {
 				typemask |= (1 << i);
 				break;
 			}
 		}
 		if (i == sizeof(dccp_pkt_types)/sizeof(char *))
 			exit_error(PARAMETER_PROBLEM,
 				   "Unknown DCCP type `%s'", ptr);
 	}

 	free(buffer);
 	return typemask;
 }

 static u_int8_t parse_dccp_option(char *optstring)
 {
 	unsigned int ret;

 	if (string_to_number(optstring, 1, 255, &ret) == -1)
 		exit_error(PARAMETER_PROBLEM, "Bad DCCP option `%s'",
 			   optstring);

 	return (u_int8_t)ret;
 }

 static int
 parse(int c, char **argv, int invert, unsigned int *flags,
       const struct ipt_entry *entry,
       unsigned int *nfcache,
       struct ipt_entry_match **match)
 {
 	struct ipt_dccp_info *einfo
 		= (struct ipt_dccp_info *)(*match)->data;

 	switch (c) {
 	case '1':
 		if (*flags & IPT_DCCP_SRC_PORTS)
 			exit_error(PARAMETER_PROBLEM,
 			           "Only one `--source-port' allowed");
 		einfo->flags |= IPT_DCCP_SRC_PORTS;
 		check_inverse(optarg, &invert, &optind, 0);
 		parse_dccp_ports(argv[optind-1], einfo->spts);
 		if (invert)
 			einfo->invflags |= IPT_DCCP_SRC_PORTS;
 		*flags |= IPT_DCCP_SRC_PORTS;
 		break;

 	case '2':
 		if (*flags & IPT_DCCP_DEST_PORTS)
 			exit_error(PARAMETER_PROBLEM,
 				   "Only one `--destination-port' allowed");
 		einfo->flags |= IPT_DCCP_DEST_PORTS;
 		check_inverse(optarg, &invert, &optind, 0);
 		parse_dccp_ports(argv[optind-1], einfo->dpts);
 		if (invert)
 			einfo->invflags |= IPT_DCCP_DEST_PORTS;
 		*flags |= IPT_DCCP_DEST_PORTS;
 		break;

 	case '3':
 		if (*flags & IPT_DCCP_TYPE)
 			exit_error(PARAMETER_PROBLEM,
 				   "Only one `--dccp-types' allowed");
 		einfo->flags |= IPT_DCCP_TYPE;
 		check_inverse(optarg, &invert, &optind, 0);
 		einfo->typemask = parse_dccp_types(argv[optind-1]);
 		if (invert)
 			einfo->invflags |= IPT_DCCP_TYPE;
 		*flags |= IPT_DCCP_TYPE;
 		break;

 	case '4':
 		if (*flags & IPT_DCCP_OPTION)
 			exit_error(PARAMETER_PROBLEM,
 				   "Only one `--dccp-option' allowed");
 		einfo->flags |= IPT_DCCP_OPTION;
 		check_inverse(optarg, &invert, &optind, 0);
 		einfo->option = parse_dccp_option(argv[optind-1]);
 		if (invert)
 			einfo->invflags |= IPT_DCCP_OPTION;
 		*flags |= IPT_DCCP_OPTION;
 		break;
 	default:
 		return 0;
 	}
 	return 1;
 }

 static void
 final_check(unsigned int flags)
 {
 }

 static char *
 port_to_service(int port)
 {
 	struct servent *service;

 	if ((service = getservbyport(htons(port), "dccp")))
 		return service->s_name;

 	return NULL;
 }

 static void
 print_port(u_int16_t port, int numeric)
 {
 	char *service;

 	if (numeric || (service = port_to_service(port)) == NULL)
 		printf("%u", port);
 	else
 		printf("%s", service);
 }

 static void
 print_ports(const char *name, u_int16_t min, u_int16_t max,
 	    int invert, int numeric)
 {
 	const char *inv = invert ? "!" : "";

 	if (min != 0 || max != 0xFFFF || invert) {
 		printf("%s", name);
 		if (min == max) {
 			printf(":%s", inv);
 			print_port(min, numeric);
 		} else {
 			printf("s:%s", inv);
 			print_port(min, numeric);
 			printf(":");
 			print_port(max, numeric);
 		}
 		printf(" ");
 	}
 }

 static void
 print_types(u_int16_t types, int inverted, int numeric)
 {
 	int have_type = 0;

 	if (inverted)
 		printf("! ");

 	while (types) {
 		unsigned int i;

 		for (i = 0; !(types & (1 << i)); i++);

 		if (have_type)
 			printf(",");
 		else
 			have_type = 1;

 		if (numeric)
 			printf("%u", i);
 		else
 			printf("%s", dccp_pkt_types[i]);

 		types &= ~(1 << i);
 	}
 }

 static void
 print_option(u_int8_t option, int invert, int numeric)
 {
 	if (option || invert)
 		printf("option=%s%u ", invert ? "!" : "", option);
 }

 /* Prints out the matchinfo. */
 static void
 print(const struct ipt_ip *ip,
       const struct ipt_entry_match *match,
       int numeric)
 {
 	const struct ipt_dccp_info *einfo =
 		(const struct ipt_dccp_info *)match->data;

 	printf("dccp ");

 	if (einfo->flags & IPT_DCCP_SRC_PORTS) {
 		print_ports("spt", einfo->spts[0], einfo->spts[1],
 			einfo->invflags & IPT_DCCP_SRC_PORTS,
 			numeric);
 	}

 	if (einfo->flags & IPT_DCCP_DEST_PORTS) {
 		print_ports("dpt", einfo->dpts[0], einfo->dpts[1],
 			einfo->invflags & IPT_DCCP_DEST_PORTS,
 			numeric);
 	}

 	if (einfo->flags & IPT_DCCP_TYPE) {
 		print_types(einfo->typemask,
 			   einfo->invflags & IPT_DCCP_TYPE,
 			   numeric);
 	}

 	if (einfo->flags & IPT_DCCP_OPTION) {
 		print_option(einfo->option,
 			     einfo->invflags & IPT_DCCP_OPTION, numeric);
 	}
 }

 /* Saves the union ipt_matchinfo in parsable form to stdout. */
 static void
 save(const struct ipt_ip *ip,
      const struct ipt_entry_match *match)
 {
 	const struct ipt_dccp_info *einfo =
 		(const struct ipt_dccp_info *)match->data;

 	if (einfo->flags & IPT_DCCP_SRC_PORTS) {
 		if (einfo->invflags & IPT_DCCP_SRC_PORTS)
 			printf("! ");
 		if (einfo->spts[0] != einfo->spts[1])
 			printf("--sport %u:%u ",
 			       einfo->spts[0], einfo->spts[1]);
 		else
 			printf("--sport %u ", einfo->spts[0]);
 	}

 	if (einfo->flags & IPT_DCCP_DEST_PORTS) {
 		if (einfo->invflags & IPT_DCCP_DEST_PORTS)
 			printf("! ");
 		if (einfo->dpts[0] != einfo->dpts[1])
 			printf("--dport %u:%u ",
 			       einfo->dpts[0], einfo->dpts[1]);
 		else
 			printf("--dport %u ", einfo->dpts[0]);
 	}

 	if (einfo->flags & IPT_DCCP_TYPE) {
 		printf("--dccp-type ");
 		print_types(einfo->typemask, einfo->invflags & IPT_DCCP_TYPE,0);
 	}

 	if (einfo->flags & IPT_DCCP_OPTION) {
 		printf("--dccp-option %s%u ",
 			einfo->typemask & IPT_DCCP_OPTION ? "! " : "",
 			einfo->option);
 	}
 }

 static
 struct iptables_match dccp
 = { .name          = "dccp",
     .version       = IPTABLES_VERSION,
     .size          = IPT_ALIGN(sizeof(struct ipt_dccp_info)),
     .userspacesize = IPT_ALIGN(sizeof(struct ipt_dccp_info)),
     .help          = &help,
     .init          = &init,
     .parse         = &parse,
     .final_check   = &final_check,
     .print         = &print,
     .save          = &save,
     .extra_opts    = opts
 };

 void _init(void)
 {
 	register_match(&dccp);
 }
	/* Shared library add-on to iptables for DCCP matching
	*
	* (C) 2005 by Harald Welte <laforge@netfilter.org>
	*
	* This program is distributed under the terms of GNU GPL v2, 1991
	*
	*/
	#include <stdio.h>
	#include <string.h>
	#include <stdlib.h>
	#include <getopt.h>
	#include <netdb.h>
	#include <ctype.h>

	#include <iptables.h>
	#include <linux/dccp.h>
	#include <linux/netfilter_ipv4/ip_tables.h>
	#include <linux/netfilter_ipv4/ipt_dccp.h>

	#if 0
	#define DEBUGP(format, first...) printf(format, ##first)
	#define static
	#else
	#define DEBUGP(format, fist...)
	#endif

	/* Initialize the match. */
	static void
	init(struct ipt_entry_match *m,
	unsigned int *nfcache)
	{
	struct ipt_dccp_info einfo = (struct ipt_dccp_info )m->data;

	memset(einfo, 0, sizeof(struct ipt_dccp_info));
	}

	static void help(void)
	{
	printf(
	"DCCP match v%s options\n"
	" --source-port [!] port[:port] match source port(s)\n"
	" --sport ...\n"
	" --destination-port [!] port[:port] match destination port(s)\n"
	" --dport ...\n"
	,
	IPTABLES_VERSION);
	}

	static struct option opts[] = {
	{ .name = "source-port", .has_arg = 1, .flag = 0, .val = '1' },
	{ .name = "sport", .has_arg = 1, .flag = 0, .val = '1' },
	{ .name = "destination-port", .has_arg = 1, .flag = 0, .val = '2' },
	{ .name = "dport", .has_arg = 1, .flag = 0, .val = '2' },
	{ .name = "dccp-types", .has_arg = 1, .flag = 0, .val = '3' },
	{ .name = "dccp-option", .has_arg = 1, .flag = 0, .val = '4' },
	{ .name = 0 }
	};

	static int
	service_to_port(const char *name)
	{
	struct servent *service;

	if ((service = getservbyname(name, "dccp")) != NULL)
	return ntohs((unsigned short) service->s_port);

	return -1;
	}

	static u_int16_t
	parse_dccp_port(const char *port)
	{
	unsigned int portnum;

	DEBUGP("%s\n", port);
	if (string_to_number(port, 0, 65535, &portnum) != -1 \|\|
	(portnum = service_to_port(port)) != -1)
	return (u_int16_t)portnum;

	exit_error(PARAMETER_PROBLEM,
	"invalid DCCP port/service `%s' specified", port);
	}

	static void
	parse_dccp_ports(const char *portstring,
	u_int16_t *ports)
	{
	char *buffer;
	char *cp;

	buffer = strdup(portstring);
	DEBUGP("%s\n", portstring);
	if ((cp = strchr(buffer, ':')) == NULL) {
	ports[0] = ports[1] = parse_dccp_port(buffer);
	}
	else {
	*cp = '\0';
	cp++;

	ports[0] = buffer[0] ? parse_dccp_port(buffer) : 0;
	ports[1] = cp[0] ? parse_dccp_port(cp) : 0xFFFF;

	if (ports[0] > ports[1])
	exit_error(PARAMETER_PROBLEM,
	"invalid portrange (min > max)");
	}
	free(buffer);
	}

	static char *dccp_pkt_types[] = {
	[DCCP_PKT_REQUEST] = "REQUEST",
	[DCCP_PKT_RESPONSE] = "RESPONSE",
	[DCCP_PKT_DATA] = "DATA",
	[DCCP_PKT_ACK] = "ACK",
	[DCCP_PKT_DATAACK] = "DATAACK",
	[DCCP_PKT_CLOSEREQ] = "CLOSEREQ",
	[DCCP_PKT_CLOSE] = "CLOSE",
	[DCCP_PKT_RESET] = "RESET",
	[DCCP_PKT_SYNC] = "SYNC",
	[DCCP_PKT_SYNCACK] = "SYNCACK",
	[DCCP_PKT_INVALID] = "INVALID",
	};

	static u_int16_t
	parse_dccp_types(const char *typestring)
	{
	u_int16_t typemask = 0;
	char ptr, buffer;

	buffer = strdup(typestring);

	for (ptr = strtok(buffer, ","); ptr; ptr = strtok(NULL, ",")) {
	unsigned int i;
	for (i = 0; i < sizeof(dccp_pkt_types)/sizeof(char *); i++) {
	if (!strcasecmp(dccp_pkt_types[i], ptr)) {
	typemask \|= (1 << i);
	break;
	}
	}
	if (i == sizeof(dccp_pkt_types)/sizeof(char *))
	exit_error(PARAMETER_PROBLEM,
	"Unknown DCCP type `%s'", ptr);
	}

	free(buffer);
	return typemask;
	}

	static u_int8_t parse_dccp_option(char *optstring)
	{
	unsigned int ret;

	if (string_to_number(optstring, 1, 255, &ret) == -1)
	exit_error(PARAMETER_PROBLEM, "Bad DCCP option `%s'",
	optstring);

	return (u_int8_t)ret;
	}

	static int
	parse(int c, char *argv, int invert, unsigned int flags,
	const struct ipt_entry *entry,
	unsigned int *nfcache,
	struct ipt_entry_match **match)
	{
	struct ipt_dccp_info *einfo
	= (struct ipt_dccp_info )(match)->data;

	switch (c) {
	case '1':
	if (*flags & IPT_DCCP_SRC_PORTS)
	exit_error(PARAMETER_PROBLEM,
	"Only one `--source-port' allowed");
	einfo->flags \|= IPT_DCCP_SRC_PORTS;
	check_inverse(optarg, &invert, &optind, 0);
	parse_dccp_ports(argv[optind-1], einfo->spts);
	if (invert)
	einfo->invflags \|= IPT_DCCP_SRC_PORTS;
	*flags \|= IPT_DCCP_SRC_PORTS;
	break;

	case '2':
	if (*flags & IPT_DCCP_DEST_PORTS)
	exit_error(PARAMETER_PROBLEM,
	"Only one `--destination-port' allowed");
	einfo->flags \|= IPT_DCCP_DEST_PORTS;
	check_inverse(optarg, &invert, &optind, 0);
	parse_dccp_ports(argv[optind-1], einfo->dpts);
	if (invert)
	einfo->invflags \|= IPT_DCCP_DEST_PORTS;
	*flags \|= IPT_DCCP_DEST_PORTS;
	break;

	case '3':
	if (*flags & IPT_DCCP_TYPE)
	exit_error(PARAMETER_PROBLEM,
	"Only one `--dccp-types' allowed");
	einfo->flags \|= IPT_DCCP_TYPE;
	check_inverse(optarg, &invert, &optind, 0);
	einfo->typemask = parse_dccp_types(argv[optind-1]);
	if (invert)
	einfo->invflags \|= IPT_DCCP_TYPE;
	*flags \|= IPT_DCCP_TYPE;
	break;

	case '4':
	if (*flags & IPT_DCCP_OPTION)
	exit_error(PARAMETER_PROBLEM,
	"Only one `--dccp-option' allowed");
	einfo->flags \|= IPT_DCCP_OPTION;
	check_inverse(optarg, &invert, &optind, 0);
	einfo->option = parse_dccp_option(argv[optind-1]);
	if (invert)
	einfo->invflags \|= IPT_DCCP_OPTION;
	*flags \|= IPT_DCCP_OPTION;
	break;
	default:
	return 0;
	}
	return 1;
	}

	static void
	final_check(unsigned int flags)
	{
	}

	static char *
	port_to_service(int port)
	{
	struct servent *service;

	if ((service = getservbyport(htons(port), "dccp")))
	return service->s_name;

	return NULL;
	}

	static void
	print_port(u_int16_t port, int numeric)
	{
	char *service;

	if (numeric \|\| (service = port_to_service(port)) == NULL)
	printf("%u", port);
	else
	printf("%s", service);
	}

	static void
	print_ports(const char *name, u_int16_t min, u_int16_t max,
	int invert, int numeric)
	{
	const char *inv = invert ? "!" : "";

	if (min != 0 \|\| max != 0xFFFF \|\| invert) {
	printf("%s", name);
	if (min == max) {
	printf(":%s", inv);
	print_port(min, numeric);
	} else {
	printf("s:%s", inv);
	print_port(min, numeric);
	printf(":");
	print_port(max, numeric);
	}
	printf(" ");
	}
	}

	static void
	print_types(u_int16_t types, int inverted, int numeric)
	{
	int have_type = 0;

	if (inverted)
	printf("! ");

	while (types) {
	unsigned int i;

	for (i = 0; !(types & (1 << i)); i++);

	if (have_type)
	printf(",");
	else
	have_type = 1;

	if (numeric)
	printf("%u", i);
	else
	printf("%s", dccp_pkt_types[i]);

	types &= ~(1 << i);
	}
	}

	static void
	print_option(u_int8_t option, int invert, int numeric)
	{
	if (option \|\| invert)
	printf("option=%s%u ", invert ? "!" : "", option);
	}

	/* Prints out the matchinfo. */
	static void
	print(const struct ipt_ip *ip,
	const struct ipt_entry_match *match,
	int numeric)
	{
	const struct ipt_dccp_info *einfo =
	(const struct ipt_dccp_info *)match->data;

	printf("dccp ");

	if (einfo->flags & IPT_DCCP_SRC_PORTS) {
	print_ports("spt", einfo->spts[0], einfo->spts[1],
	einfo->invflags & IPT_DCCP_SRC_PORTS,
	numeric);
	}

	if (einfo->flags & IPT_DCCP_DEST_PORTS) {
	print_ports("dpt", einfo->dpts[0], einfo->dpts[1],
	einfo->invflags & IPT_DCCP_DEST_PORTS,
	numeric);
	}

	if (einfo->flags & IPT_DCCP_TYPE) {
	print_types(einfo->typemask,
	einfo->invflags & IPT_DCCP_TYPE,
	numeric);
	}

	if (einfo->flags & IPT_DCCP_OPTION) {
	print_option(einfo->option,
	einfo->invflags & IPT_DCCP_OPTION, numeric);
	}
	}

	/* Saves the union ipt_matchinfo in parsable form to stdout. */
	static void
	save(const struct ipt_ip *ip,
	const struct ipt_entry_match *match)
	{
	const struct ipt_dccp_info *einfo =
	(const struct ipt_dccp_info *)match->data;

	if (einfo->flags & IPT_DCCP_SRC_PORTS) {
	if (einfo->invflags & IPT_DCCP_SRC_PORTS)
	printf("! ");
	if (einfo->spts[0] != einfo->spts[1])
	printf("--sport %u:%u ",
	einfo->spts[0], einfo->spts[1]);
	else
	printf("--sport %u ", einfo->spts[0]);
	}

	if (einfo->flags & IPT_DCCP_DEST_PORTS) {
	if (einfo->invflags & IPT_DCCP_DEST_PORTS)
	printf("! ");
	if (einfo->dpts[0] != einfo->dpts[1])
	printf("--dport %u:%u ",
	einfo->dpts[0], einfo->dpts[1]);
	else
	printf("--dport %u ", einfo->dpts[0]);
	}

	if (einfo->flags & IPT_DCCP_TYPE) {
	printf("--dccp-type ");
	print_types(einfo->typemask, einfo->invflags & IPT_DCCP_TYPE,0);
	}

	if (einfo->flags & IPT_DCCP_OPTION) {
	printf("--dccp-option %s%u ",
	einfo->typemask & IPT_DCCP_OPTION ? "! " : "",
	einfo->option);
	}
	}

	static
	struct iptables_match dccp
	= { .name = "dccp",
	.version = IPTABLES_VERSION,
	.size = IPT_ALIGN(sizeof(struct ipt_dccp_info)),
	.userspacesize = IPT_ALIGN(sizeof(struct ipt_dccp_info)),
	.help = &help,
	.init = &init,
	.parse = &parse,
	.final_check = &final_check,
	.print = &print,
	.save = &save,
	.extra_opts = opts
	};

	void _init(void)
	{
	register_match(&dccp);
	}