Initial import

1 files changed, 83 insertions, 0 deletions

diff --git a/net/ipv4/netfilter/nf_nat_proto_icmp.c b/net/ipv4/netfilter/nf_nat_proto_icmp.c
new file mode 100644
index 000000000..4557b4ab8
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_icmp.c
@@ -0,0 +1,83 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/export.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_l4proto.h>
+
+static bool
+icmp_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
+icmp_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 u_int16_t id;
+	unsigned int range_size;
+	unsigned int i;
+
+	range_size = ntohs(range->max_proto.icmp.id) -
+		     ntohs(range->min_proto.icmp.id) + 1;
+	/* If no range specified... */
+	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;
+	}
+	return;
+}
+
+static bool
+icmp_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 icmphdr *hdr;
+
+	if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+		return false;
+
+	hdr = (struct icmphdr *)(skb->data + hdroff);
+	inet_proto_csum_replace2(&hdr->checksum, skb,
+				 hdr->un.echo.id, tuple->src.u.icmp.id, 0);
+	hdr->un.echo.id = tuple->src.u.icmp.id;
+	return true;
+}
+
+const struct nf_nat_l4proto nf_nat_l4proto_icmp = {
+	.l4proto		= IPPROTO_ICMP,
+	.manip_pkt		= icmp_manip_pkt,
+	.in_range		= icmp_in_range,
+	.unique_tuple		= icmp_unique_tuple,
+#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
+	.nlattr_to_range	= nf_nat_l4proto_nlattr_to_range,
+#endif
+};