--- /dev/null
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/socket.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <net/fou.h>
+#include <net/ip.h>
+#include <net/ip6_tunnel.h>
+#include <net/ip6_checksum.h>
+#include <net/protocol.h>
+#include <net/udp.h>
+#include <net/udp_tunnel.h>
+
+static void fou6_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ struct flowi6 *fl6, u8 *protocol, __be16 sport)
+{
+ struct udphdr *uh;
+
+ skb_push(skb, sizeof(struct udphdr));
+ skb_reset_transport_header(skb);
+
+ uh = udp_hdr(skb);
+
+ uh->dest = e->dport;
+ uh->source = sport;
+ uh->len = htons(skb->len);
+ udp6_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM6), skb,
+ &fl6->saddr, &fl6->daddr, skb->len);
+
+ *protocol = IPPROTO_UDP;
+}
+
+int fou6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ u8 *protocol, struct flowi6 *fl6)
+{
+ __be16 sport;
+ int err;
+ int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ?
+ SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+
+ err = __fou_build_header(skb, e, protocol, &sport, type);
+ if (err)
+ return err;
+
+ fou6_build_udp(skb, e, fl6, protocol, sport);
+
+ return 0;
+}
+EXPORT_SYMBOL(fou6_build_header);
+
+int gue6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
+ u8 *protocol, struct flowi6 *fl6)
+{
+ __be16 sport;
+ int err;
+ int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ?
+ SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
+
+ err = __gue_build_header(skb, e, protocol, &sport, type);
+ if (err)
+ return err;
+
+ fou6_build_udp(skb, e, fl6, protocol, sport);
+
+ return 0;
+}
+EXPORT_SYMBOL(gue6_build_header);
+
+#ifdef CONFIG_NET_FOU_IP_TUNNELS
+
+static const struct ip6_tnl_encap_ops fou_ip6tun_ops = {
+ .encap_hlen = fou_encap_hlen,
+ .build_header = fou6_build_header,
+};
+
+static const struct ip6_tnl_encap_ops gue_ip6tun_ops = {
+ .encap_hlen = gue_encap_hlen,
+ .build_header = gue6_build_header,
+};
+
+static int ip6_tnl_encap_add_fou_ops(void)
+{
+ int ret;
+
+ ret = ip6_tnl_encap_add_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
+ if (ret < 0) {
+ pr_err("can't add fou6 ops\n");
+ return ret;
+ }
+
+ ret = ip6_tnl_encap_add_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE);
+ if (ret < 0) {
+ pr_err("can't add gue6 ops\n");
+ ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void ip6_tnl_encap_del_fou_ops(void)
+{
+ ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
+ ip6_tnl_encap_del_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE);
+}
+
+#else
+
+static int ip6_tnl_encap_add_fou_ops(void)
+{
+ return 0;
+}
+
+static void ip6_tnl_encap_del_fou_ops(void)
+{
+}
+
+#endif
+
+static int __init fou6_init(void)
+{
+ int ret;
+
+ ret = ip6_tnl_encap_add_fou_ops();
+
+ return ret;
+}
+
+static void __exit fou6_fini(void)
+{
+ ip6_tnl_encap_del_fou_ops();
+}
+
+module_init(fou6_init);
+module_exit(fou6_fini);
+MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
+MODULE_LICENSE("GPL");