+++ /dev/null
-/* Shared library add-on to iptables for the TTL target
- * (C) 2000 by Harald Welte <laforge@gnumonks.org>
- *
- * $Id$
- *
- * This program is distributed under the terms of GNU GPL
- */
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
-#include <getopt.h>
-#include <iptables.h>
-
-#include <linux/netfilter_ipv4/ip_tables.h>
-#include <linux/netfilter_ipv4/ipt_TTL.h>
-
-#define IPT_TTL_USED 1
-
-static void TTL_help(void)
-{
- printf(
-"TTL target options\n"
-" --ttl-set value Set TTL to <value 0-255>\n"
-" --ttl-dec value Decrement TTL by <value 1-255>\n"
-" --ttl-inc value Increment TTL by <value 1-255>\n");
-}
-
-static int TTL_parse(int c, char **argv, int invert, unsigned int *flags,
- const void *entry, struct xt_entry_target **target)
-{
- struct ipt_TTL_info *info = (struct ipt_TTL_info *) (*target)->data;
- unsigned int value;
-
- if (*flags & IPT_TTL_USED) {
- exit_error(PARAMETER_PROBLEM,
- "Can't specify TTL option twice");
- }
-
- if (!optarg)
- exit_error(PARAMETER_PROBLEM,
- "TTL: You must specify a value");
-
- if (check_inverse(optarg, &invert, NULL, 0))
- exit_error(PARAMETER_PROBLEM,
- "TTL: unexpected `!'");
-
- if (string_to_number(optarg, 0, 255, &value) == -1)
- exit_error(PARAMETER_PROBLEM,
- "TTL: Expected value between 0 and 255");
-
- switch (c) {
-
- case '1':
- info->mode = IPT_TTL_SET;
- break;
-
- case '2':
- if (value == 0) {
- exit_error(PARAMETER_PROBLEM,
- "TTL: decreasing by 0?");
- }
-
- info->mode = IPT_TTL_DEC;
- break;
-
- case '3':
- if (value == 0) {
- exit_error(PARAMETER_PROBLEM,
- "TTL: increasing by 0?");
- }
-
- info->mode = IPT_TTL_INC;
- break;
-
- default:
- return 0;
-
- }
-
- info->ttl = value;
- *flags |= IPT_TTL_USED;
-
- return 1;
-}
-
-static void TTL_check(unsigned int flags)
-{
- if (!(flags & IPT_TTL_USED))
- exit_error(PARAMETER_PROBLEM,
- "TTL: You must specify an action");
-}
-
-static void TTL_save(const void *ip, const struct xt_entry_target *target)
-{
- const struct ipt_TTL_info *info =
- (struct ipt_TTL_info *) target->data;
-
- switch (info->mode) {
- case IPT_TTL_SET:
- printf("--ttl-set ");
- break;
- case IPT_TTL_DEC:
- printf("--ttl-dec ");
- break;
-
- case IPT_TTL_INC:
- printf("--ttl-inc ");
- break;
- }
- printf("%u ", info->ttl);
-}
-
-static void TTL_print(const void *ip, const struct xt_entry_target *target,
- int numeric)
-{
- const struct ipt_TTL_info *info =
- (struct ipt_TTL_info *) target->data;
-
- printf("TTL ");
- switch (info->mode) {
- case IPT_TTL_SET:
- printf("set to ");
- break;
- case IPT_TTL_DEC:
- printf("decrement by ");
- break;
- case IPT_TTL_INC:
- printf("increment by ");
- break;
- }
- printf("%u ", info->ttl);
-}
-
-static const struct option TTL_opts[] = {
- { "ttl-set", 1, NULL, '1' },
- { "ttl-dec", 1, NULL, '2' },
- { "ttl-inc", 1, NULL, '3' },
- { .name = NULL }
-};
-
-static struct xtables_target ttl_tg_reg = {
- .name = "TTL",
- .version = XTABLES_VERSION,
- .family = PF_INET,
- .size = XT_ALIGN(sizeof(struct ipt_TTL_info)),
- .userspacesize = XT_ALIGN(sizeof(struct ipt_TTL_info)),
- .help = TTL_help,
- .parse = TTL_parse,
- .final_check = TTL_check,
- .print = TTL_print,
- .save = TTL_save,
- .extra_opts = TTL_opts,
-};
-
-void _init(void)
-{
- xtables_register_target(&ttl_tg_reg);
-}