[NETFILTER]: nf_nat: add UDP-Lite support
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/ipv4/netfilter/nf_nat_proto_udplite.c b/net/ipv4/netfilter/nf_nat_proto_udplite.c
new file mode 100644
index 0000000..b29346d
--- /dev/null
+++ b/net/ipv4/netfilter/nf_nat_proto_udplite.c
@@ -0,0 +1,99 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2008 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.
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+
+#include <linux/netfilter.h>
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_protocol.h>
+
+static u_int16_t udplite_port_rover;
+
+static int
+udplite_unique_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct)
+{
+ return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
+ &udplite_port_rover);
+}
+
+static int
+udplite_manip_pkt(struct sk_buff *skb,
+ unsigned int iphdroff,
+ const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype)
+{
+ const struct iphdr *iph = (struct iphdr *)(skb->data + iphdroff);
+ struct udphdr *hdr;
+ unsigned int hdroff = iphdroff + iph->ihl*4;
+ __be32 oldip, newip;
+ __be16 *portptr, newport;
+
+ if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
+ return 0;
+
+ iph = (struct iphdr *)(skb->data + iphdroff);
+ hdr = (struct udphdr *)(skb->data + hdroff);
+
+ if (maniptype == IP_NAT_MANIP_SRC) {
+ /* Get rid of src ip and src pt */
+ oldip = iph->saddr;
+ newip = tuple->src.u3.ip;
+ newport = tuple->src.u.udp.port;
+ portptr = &hdr->source;
+ } else {
+ /* Get rid of dst ip and dst pt */
+ oldip = iph->daddr;
+ newip = tuple->dst.u3.ip;
+ newport = tuple->dst.u.udp.port;
+ portptr = &hdr->dest;
+ }
+
+ inet_proto_csum_replace4(&hdr->check, skb, oldip, newip, 1);
+ inet_proto_csum_replace2(&hdr->check, skb, *portptr, newport, 0);
+ if (!hdr->check)
+ hdr->check = CSUM_MANGLED_0;
+
+ *portptr = newport;
+ return 1;
+}
+
+static const struct nf_nat_protocol nf_nat_protocol_udplite = {
+ .protonum = IPPROTO_UDPLITE,
+ .me = THIS_MODULE,
+ .manip_pkt = udplite_manip_pkt,
+ .in_range = nf_nat_proto_in_range,
+ .unique_tuple = udplite_unique_tuple,
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+ .range_to_nlattr = nf_nat_proto_range_to_nlattr,
+ .nlattr_to_range = nf_nat_proto_nlattr_to_range,
+#endif
+};
+
+static int __init nf_nat_proto_udplite_init(void)
+{
+ return nf_nat_protocol_register(&nf_nat_protocol_udplite);
+}
+
+static void __exit nf_nat_proto_udplite_fini(void)
+{
+ nf_nat_protocol_unregister(&nf_nat_protocol_udplite);
+}
+
+module_init(nf_nat_proto_udplite_init);
+module_exit(nf_nat_proto_udplite_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("UDP-Lite NAT protocol helper");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");