1 files changed, 108 insertions, 0 deletions
diff --git a/extensions/libct_proto_icmp.c b/extensions/libct_proto_icmp.c
new file mode 100644
index 0000000..e7cb04d
--- /dev/null
+++ b/extensions/libct_proto_icmp.c
@@ -0,0 +1,108 @@
+/*
+ * (C) 2005 by Pablo Neira Ayuso <pablo@eurodev.net>
+ *	       Harald Welte <laforge@netfilter.org>
+ *
+ *      This program is free software; you can redistribute it and/or modify
+ *      it under the terms of the GNU General Public License as published by
+ *      the Free Software Foundation; either version 2 of the License, or
+ *      (at your option) any later version.
+ *
+ */
+#include <stdio.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <netinet/in.h> /* For htons */
+#include <netinet/ip_icmp.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack.h>
+#include <libnetfilter_conntrack/libnetfilter_conntrack_icmp.h>
+#include "conntrack.h"
+
+static struct option opts[] = {
+	{"icmp-type", 1, 0, '1'},
+	{"icmp-code", 1, 0, '2'},
+	{"icmp-id", 1, 0, '3'},
+	{0, 0, 0, 0}
+};
+
+static void help()
+{
+	fprintf(stdout, "--icmp-type            icmp type\n");
+	fprintf(stdout, "--icmp-code            icmp code\n");
+	fprintf(stdout, "--icmp-id              icmp id\n");
+}
+
+/* Add 1; spaces filled with 0. */
+static u_int8_t invmap[]
+	= { [ICMP_ECHO] = ICMP_ECHOREPLY + 1,
+	    [ICMP_ECHOREPLY] = ICMP_ECHO + 1,
+	    [ICMP_TIMESTAMP] = ICMP_TIMESTAMPREPLY + 1,
+	    [ICMP_TIMESTAMPREPLY] = ICMP_TIMESTAMP + 1,
+	    [ICMP_INFO_REQUEST] = ICMP_INFO_REPLY + 1,
+	    [ICMP_INFO_REPLY] = ICMP_INFO_REQUEST + 1,
+	    [ICMP_ADDRESS] = ICMP_ADDRESSREPLY + 1,
+	    [ICMP_ADDRESSREPLY] = ICMP_ADDRESS + 1};
+
+static int parse(char c, char *argv[], 
+		 struct nfct_tuple *orig,
+		 struct nfct_tuple *reply,
+		 struct nfct_tuple *exptuple,
+		 struct nfct_tuple *mask,
+		 union nfct_protoinfo *proto,
+		 unsigned int *flags)
+{
+	switch(c) {
+		case '1':
+			if (optarg) {
+				orig->l4dst.icmp.type = atoi(optarg);
+				reply->l4dst.icmp.type =
+					invmap[orig->l4dst.icmp.type] - 1;
+				*flags |= ICMP_TYPE;
+			}
+			break;
+		case '2':
+			if (optarg) {
+				orig->l4dst.icmp.code = atoi(optarg);
+				reply->l4dst.icmp.code = 0;
+				*flags |= ICMP_CODE;
+			}
+			break;
+		case '3':
+			if (optarg) {
+				orig->l4src.icmp.id = htons(atoi(optarg));
+				reply->l4dst.icmp.id = 0;
+				*flags |= ICMP_ID;
+			}
+			break;
+	}
+	return 1;
+}
+
+static int final_check(unsigned int flags,
+		       unsigned int command,
+		       struct nfct_tuple *orig,
+		       struct nfct_tuple *reply)
+{
+	if (!(flags & ICMP_TYPE))
+		return 0;
+	else if (!(flags & ICMP_CODE))
+		return 0;
+
+	return 1;
+}
+
+static struct ctproto_handler icmp = {
+	.name 		= "icmp",
+	.protonum	= IPPROTO_ICMP,
+	.parse_opts	= parse,
+	.final_check	= final_check,
+	.help		= help,
+	.opts		= opts,
+	.version	= VERSION,
+};
+
+static void __attribute__ ((constructor)) init(void);
+
+static void init(void)
+{
+	register_proto(&icmp);
+}