1 files changed, 94 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6t_mh.c b/net/ipv6/netfilter/ip6t_mh.c
new file mode 100644
index 00000000..0c90c66b
--- /dev/null
+++ b/net/ipv6/netfilter/ip6t_mh.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C)2006 USAGI/WIDE Project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Author:
+ *	Masahide NAKAMURA @USAGI <masahide.nakamura.cz@hitachi.com>
+ *
+ * Based on net/netfilter/xt_tcpudp.c
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/types.h>
+#include <linux/module.h>
+#include <net/ip.h>
+#include <linux/ipv6.h>
+#include <net/ipv6.h>
+#include <net/mip6.h>
+
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv6/ip6t_mh.h>
+
+MODULE_DESCRIPTION("Xtables: IPv6 Mobility Header match");
+MODULE_LICENSE("GPL");
+
+/* Returns 1 if the type is matched by the range, 0 otherwise */
+static inline bool
+type_match(u_int8_t min, u_int8_t max, u_int8_t type, bool invert)
+{
+	return (type >= min && type <= max) ^ invert;
+}
+
+static bool mh_mt6(const struct sk_buff *skb, struct xt_action_param *par)
+{
+	struct ip6_mh _mh;
+	const struct ip6_mh *mh;
+	const struct ip6t_mh *mhinfo = par->matchinfo;
+
+	/* Must not be a fragment. */
+	if (par->fragoff != 0)
+		return false;
+
+	mh = skb_header_pointer(skb, par->thoff, sizeof(_mh), &_mh);
+	if (mh == NULL) {
+		/* We've been asked to examine this packet, and we
+		   can't.  Hence, no choice but to drop. */
+		pr_debug("Dropping evil MH tinygram.\n");
+		par->hotdrop = true;
+		return false;
+	}
+
+	if (mh->ip6mh_proto != IPPROTO_NONE) {
+		pr_debug("Dropping invalid MH Payload Proto: %u\n",
+			 mh->ip6mh_proto);
+		par->hotdrop = true;
+		return false;
+	}
+
+	return type_match(mhinfo->types[0], mhinfo->types[1], mh->ip6mh_type,
+			  !!(mhinfo->invflags & IP6T_MH_INV_TYPE));
+}
+
+static int mh_mt6_check(const struct xt_mtchk_param *par)
+{
+	const struct ip6t_mh *mhinfo = par->matchinfo;
+
+	/* Must specify no unknown invflags */
+	return (mhinfo->invflags & ~IP6T_MH_INV_MASK) ? -EINVAL : 0;
+}
+
+static struct xt_match mh_mt6_reg __read_mostly = {
+	.name		= "mh",
+	.family		= NFPROTO_IPV6,
+	.checkentry	= mh_mt6_check,
+	.match		= mh_mt6,
+	.matchsize	= sizeof(struct ip6t_mh),
+	.proto		= IPPROTO_MH,
+	.me		= THIS_MODULE,
+};
+
+static int __init mh_mt6_init(void)
+{
+	return xt_register_match(&mh_mt6_reg);
+}
+
+static void __exit mh_mt6_exit(void)
+{
+	xt_unregister_match(&mh_mt6_reg);
+}
+
+module_init(mh_mt6_init);
+module_exit(mh_mt6_exit);