From 60fa37542ef0b06051937bf908c6da1ebcb93016 Mon Sep 17 00:00:00 2001
From: rusty <rusty>
Date: Wed, 4 Oct 2000 15:27:07 +0000
Subject: Harald Welte's ttl stuff. This patch adds two new modules to the
 netfilter CVS patch-o-matic system:

A TTL match and a TTL target for setting/incrementing/decrementing the TTL.
---
 extensions/libipt_ttl.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 extensions/libipt_ttl.c

(limited to 'extensions/libipt_ttl.c')

diff --git a/extensions/libipt_ttl.c b/extensions/libipt_ttl.c
new file mode 100644
index 0000000..1acd7cf
--- /dev/null
+++ b/extensions/libipt_ttl.c
@@ -0,0 +1,111 @@
+/* Shared library add-on to iptables to add TTL matching support 
+ * (C) 2000 by Harald Welte <laforge@gnumonks.org>
+ *
+ * Version: 1.3
+ *
+ * This program is released under the terms of GNU GPL */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <getopt.h>
+#include <iptables.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_ttl.h>
+
+static void help(void) 
+{
+	printf(
+"TTL match v%s options:\n"
+"  --ttl value		Match time to live value\n", NETFILTER_VERSION);
+}
+
+static void init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+	/* caching not yet implemented */
+}
+
+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_ttl_info *info = (struct ipt_ttl_info *) (*match)->data;
+	u_int8_t value;
+
+	switch (c) {
+		case '1':
+			if (check_inverse(optarg, &invert))
+				optind++;
+			value = atoi(argv[optind-1]);
+
+			/* is 0 allowed? */
+			info->ttl = value;
+			if (invert)
+				info->invert = 1;
+			break;
+		default:
+			return 0;
+
+	}
+
+	return 1;
+}
+
+static void final_check(unsigned int flags)
+{
+	if (!flags) 
+		exit_error(PARAMETER_PROBLEM,
+			"TTL match: You must specify `--ttl'");
+}
+
+static void print(const struct ipt_ip *ip, 
+		const struct ipt_entry_match *match,
+		int numeric)
+{
+	const struct ipt_ttl_info *info = 
+		(struct ipt_ttl_info *) match->data;
+
+	printf("TTL match ");
+	if (info->invert)
+		printf("!");
+	printf("%u ", info->ttl);
+}
+
+static void save(const struct ipt_ip *ip, 
+		const struct ipt_entry_match *match)
+{
+	const struct ipt_ttl_info *info =
+		(struct ipt_ttl_info *) match->data;
+
+	printf("--ttl ");
+	if (info->invert)
+		printf("!");
+	printf("%u ", info->ttl);
+}
+
+static struct option opts[] = {
+	{ "ttl", 0, '1' },
+	{ 0 }
+};
+
+struct iptables_match ttl = {
+	NULL,
+	"ttl",
+	NETFILTER_VERSION,
+	IPT_ALIGN(sizeof(struct ipt_ttl_info)),
+	IPT_ALIGN(sizeof(struct ipt_ttl_info)),
+	&help,
+	&init,
+	&parse,
+	&final_check,
+	&print,
+	&save,
+	opts
+};
+
+
+void _init(void) 
+{
+	register_match(&ttl);
+}
-- 
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