From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?=
 <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 net/ipv6/netfilter/nf_nat_proto_icmpv6.c | 90 ++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 net/ipv6/netfilter/nf_nat_proto_icmpv6.c

(limited to 'net/ipv6/netfilter/nf_nat_proto_icmpv6.c')

diff --git a/net/ipv6/netfilter/nf_nat_proto_icmpv6.c b/net/ipv6/netfilter/nf_nat_proto_icmpv6.c
new file mode 100644
index 000000000..2205e8eee
--- /dev/null
+++ b/net/ipv6/netfilter/nf_nat_proto_icmpv6.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2011 Patrick Mchardy <kaber@trash.net>
+ *
+ * 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.
+ *
+ * Based on Rusty Russell's IPv4 ICMP NAT code. Development of IPv6
+ * NAT funded by Astaro.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/icmpv6.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+#include <net/netfilter/nf_nat_l4proto.h>
+
+static bool
+icmpv6_in_range(const struct nf_conntrack_tuple *tuple,
+		enum nf_nat_manip_type maniptype,
+		const union nf_conntrack_man_proto *min,
+		const union nf_conntrack_man_proto *max)
+{
+	return ntohs(tuple->src.u.icmp.id) >= ntohs(min->icmp.id) &&
+	       ntohs(tuple->src.u.icmp.id) <= ntohs(max->icmp.id);
+}
+
+static void
+icmpv6_unique_tuple(const struct nf_nat_l3proto *l3proto,
+		    struct nf_conntrack_tuple *tuple,
+		    const struct nf_nat_range *range,
+		    enum nf_nat_manip_type maniptype,
+		    const struct nf_conn *ct)
+{
+	static u16 id;
+	unsigned int range_size;
+	unsigned int i;
+
+	range_size = ntohs(range->max_proto.icmp.id) -
+		     ntohs(range->min_proto.icmp.id) + 1;
+
+	if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED))
+		range_size = 0xffff;
+
+	for (i = 0; ; ++id) {
+		tuple->src.u.icmp.id = htons(ntohs(range->min_proto.icmp.id) +
+					     (id % range_size));
+		if (++i == range_size || !nf_nat_used_tuple(tuple, ct))
+			return;
+	}
+}
+
+static bool
+icmpv6_manip_pkt(struct sk_buff *skb,
+		 const struct nf_nat_l3proto *l3proto,
+		 unsigned int iphdroff, unsigned int hdroff,
+		 const struct nf_conntrack_tuple *tuple,
+		 enum nf_nat_manip_type maniptype)
+{
+	struct icmp6hdr *hdr;
+
+	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+		return false;
+
+	hdr = (struct icmp6hdr *)(skb->data + hdroff);
+	l3proto->csum_update(skb, iphdroff, &hdr->icmp6_cksum,
+			     tuple, maniptype);
+	if (hdr->icmp6_type == ICMPV6_ECHO_REQUEST ||
+	    hdr->icmp6_type == ICMPV6_ECHO_REPLY) {
+		inet_proto_csum_replace2(&hdr->icmp6_cksum, skb,
+					 hdr->icmp6_identifier,
+					 tuple->src.u.icmp.id, 0);
+		hdr->icmp6_identifier = tuple->src.u.icmp.id;
+	}
+	return true;
+}
+
+const struct nf_nat_l4proto nf_nat_l4proto_icmpv6 = {
+	.l4proto		= IPPROTO_ICMPV6,
+	.manip_pkt		= icmpv6_manip_pkt,
+	.in_range		= icmpv6_in_range,
+	.unique_tuple		= icmpv6_unique_tuple,
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+	.nlattr_to_range	= nf_nat_l4proto_nlattr_to_range,
+#endif
+};
-- 
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