blob: e5782a85d049ca91a411fc3dbf827a442bdd674c [file] [log] [blame]
/* 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 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_port(buffer, "dccp");
}
else {
*cp = '\0';
cp++;
ports[0] = buffer[0] ? parse_port(buffer, "dccp") : 0;
ports[1] = cp[0] ? parse_port(cp, "dccp") : 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);
}