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/* Shared library add-on to iptables to add ULOG support.
*
* (C) 2000 by Harald Welte <laforge@sunbeam.franken.de>
*
* This software is released under the terms of GNU GPL
*
* libipt_ULOG.c,v 1.3 2000/07/31 11:51:50 laforge Exp
*/
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
#include <getopt.h>
#include <iptables.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_ULOG.h>
#define ULOG_DEFAULT_NLGROUP 1
void print_groups(unsigned int gmask)
{
int b;
unsigned int test;
for (b = 31; b >= 0; b--) {
test = (1 << b);
if (gmask & test)
printf("%d ", b + 1);
}
}
/* Function which prints out usage message. */
static void help(void)
{
printf("ULOG v%s options:\n"
" --ulog-nlgroup nlgroup NETLINK grouo used for logging\n"
" --ulog-cprange size Bytes of each packet to be passed\n"
" --ulog-prefix prefix Prefix log messages with this prefix.\n\n",
NETFILTER_VERSION);
}
static struct option opts[] = {
{"ulog-nlgroup", 1, 0, '!'},
{"ulog-prefix", 1, 0, '#'},
{"ulog-cprange", 1, 0, 'A'},
{0}
};
/* Initialize the target. */
static void init(struct ipt_entry_target *t, unsigned int *nfcache)
{
struct ipt_ulog_info *loginfo = (struct ipt_ulog_info *) t->data;
loginfo->nl_group = ULOG_DEFAULT_NLGROUP;
/* Can't cache this */
*nfcache |= NFC_UNKNOWN;
}
#define IPT_LOG_OPT_NLGROUP 0x01
#define IPT_LOG_OPT_PREFIX 0x02
#define IPT_LOG_OPT_CPRANGE 0x04
/* Function which parses command options; returns true if it
ate an option */
static int parse(int c, char **argv, int invert, unsigned int *flags,
const struct ipt_entry *entry,
struct ipt_entry_target **target)
{
struct ipt_ulog_info *loginfo =
(struct ipt_ulog_info *) (*target)->data;
int group_d;
switch (c) {
case '!':
if (*flags & IPT_LOG_OPT_NLGROUP)
exit_error(PARAMETER_PROBLEM,
"Can't specify --ulog-nlgroup twice");
if (check_inverse(optarg, &invert))
exit_error(PARAMETER_PROBLEM,
"Unexpected `!' after --ulog-nlgroup");
group_d = atoi(optarg);
if (group_d > 32 || group_d < 1)
exit_error(PARAMETER_PROBLEM,
"--ulog-nlgroup has to be between 1 and 32");
loginfo->nl_group = (1 << (group_d - 1));
*flags |= IPT_LOG_OPT_NLGROUP;
break;
case '#':
if (*flags & IPT_LOG_OPT_PREFIX)
exit_error(PARAMETER_PROBLEM,
"Can't specify --ulog-prefix twice");
if (check_inverse(optarg, &invert))
exit_error(PARAMETER_PROBLEM,
"Unexpected `!' after --ulog-prefix");
if (strlen(optarg) > sizeof(loginfo->prefix) - 1)
exit_error(PARAMETER_PROBLEM,
"Maximum prefix length %u for --ulog-prefix",
sizeof(loginfo->prefix) - 1);
strcpy(loginfo->prefix, optarg);
*flags |= IPT_LOG_OPT_PREFIX;
break;
case 'A':
if (*flags & IPT_LOG_OPT_CPRANGE)
exit_error(PARAMETER_PROBLEM,
"Can't specify --ulog-cprange twice");
if (atoi(optarg) < 0)
exit_error(PARAMETER_PROBLEM,
"Negative copy range?");
loginfo->copy_range = atoi(optarg);
*flags |= IPT_LOG_OPT_CPRANGE;
break;
}
return 1;
}
/* Final check; nothing. */
static void final_check(unsigned int flags)
{
}
/* Saves the union ipt_targinfo in parsable form to stdout. */
static void save(const struct ipt_ip *ip,
const struct ipt_entry_target *target)
{
const struct ipt_ulog_info *loginfo
= (const struct ipt_ulog_info *) target->data;
if (strcmp(loginfo->prefix, "") != 0)
printf("--ulog-prefix %s ", loginfo->prefix);
if (loginfo->nl_group != ULOG_DEFAULT_NLGROUP) {
printf("--ulog-nlgroup ");
print_groups(loginfo->nl_group);
printf("\n");
}
if (loginfo->copy_range)
printf("--ulog-cprange %d", loginfo->copy_range);
}
/* Prints out the targinfo. */
static void
print(const struct ipt_ip *ip,
const struct ipt_entry_target *target, int numeric)
{
const struct ipt_ulog_info *loginfo
= (const struct ipt_ulog_info *) target->data;
printf("ULOG ");
printf("copy_range %d nlgroup ", loginfo->copy_range);
print_groups(loginfo->nl_group);
if (strcmp(loginfo->prefix, "") != 0)
printf("prefix `%s' ", loginfo->prefix);
}
struct iptables_target ulog = { NULL,
"ULOG",
NETFILTER_VERSION,
IPT_ALIGN(sizeof(struct ipt_ulog_info)),
IPT_ALIGN(sizeof(struct ipt_ulog_info)),
&help,
&init,
&parse,
&final_check,
&print,
&save,
opts
};
void _init(void)
{
register_target(&ulog);
}
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