1#include <linux/module.h>
  2#include <linux/errno.h>
  3#include <linux/socket.h>
  4#include <linux/skbuff.h>
  5#include <linux/ip.h>
  6#include <linux/udp.h>
  7#include <linux/types.h>
  8#include <linux/kernel.h>
  9#include <net/fou.h>
 10#include <net/ip.h>
 11#include <net/ip6_tunnel.h>
 12#include <net/ip6_checksum.h>
 13#include <net/protocol.h>
 14#include <net/udp.h>
 15#include <net/udp_tunnel.h>
 16
 17static void fou6_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
 18			   struct flowi6 *fl6, u8 *protocol, __be16 sport)
 19{
 20	struct udphdr *uh;
 21
 22	skb_push(skb, sizeof(struct udphdr));
 23	skb_reset_transport_header(skb);
 24
 25	uh = udp_hdr(skb);
 26
 27	uh->dest = e->dport;
 28	uh->source = sport;
 29	uh->len = htons(skb->len);
 30	udp6_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM6), skb,
 31		      &fl6->saddr, &fl6->daddr, skb->len);
 32
 33	*protocol = IPPROTO_UDP;
 34}
 35
 36int fou6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 37		      u8 *protocol, struct flowi6 *fl6)
 38{
 39	__be16 sport;
 40	int err;
 41	int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ?
 42		SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
 43
 44	err = __fou_build_header(skb, e, protocol, &sport, type);
 45	if (err)
 46		return err;
 47
 48	fou6_build_udp(skb, e, fl6, protocol, sport);
 49
 50	return 0;
 51}
 52EXPORT_SYMBOL(fou6_build_header);
 53
 54int gue6_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
 55		      u8 *protocol, struct flowi6 *fl6)
 56{
 57	__be16 sport;
 58	int err;
 59	int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM6 ?
 60		SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
 61
 62	err = __gue_build_header(skb, e, protocol, &sport, type);
 63	if (err)
 64		return err;
 65
 66	fou6_build_udp(skb, e, fl6, protocol, sport);
 67
 68	return 0;
 69}
 70EXPORT_SYMBOL(gue6_build_header);
 71
 72#if IS_ENABLED(CONFIG_IPV6_FOU_TUNNEL)
 73
 74static const struct ip6_tnl_encap_ops fou_ip6tun_ops = {
 75	.encap_hlen = fou_encap_hlen,
 76	.build_header = fou6_build_header,
 77};
 78
 79static const struct ip6_tnl_encap_ops gue_ip6tun_ops = {
 80	.encap_hlen = gue_encap_hlen,
 81	.build_header = gue6_build_header,
 82};
 83
 84static int ip6_tnl_encap_add_fou_ops(void)
 85{
 86	int ret;
 87
 88	ret = ip6_tnl_encap_add_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
 89	if (ret < 0) {
 90		pr_err("can't add fou6 ops\n");
 91		return ret;
 92	}
 93
 94	ret = ip6_tnl_encap_add_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE);
 95	if (ret < 0) {
 96		pr_err("can't add gue6 ops\n");
 97		ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
 98		return ret;
 99	}
100
101	return 0;
102}
103
104static void ip6_tnl_encap_del_fou_ops(void)
105{
106	ip6_tnl_encap_del_ops(&fou_ip6tun_ops, TUNNEL_ENCAP_FOU);
107	ip6_tnl_encap_del_ops(&gue_ip6tun_ops, TUNNEL_ENCAP_GUE);
108}
109
110#else
111
112static int ip6_tnl_encap_add_fou_ops(void)
113{
114	return 0;
115}
116
117static void ip6_tnl_encap_del_fou_ops(void)
118{
119}
120
121#endif
122
123static int __init fou6_init(void)
124{
125	int ret;
126
127	ret = ip6_tnl_encap_add_fou_ops();
128
129	return ret;
130}
131
132static void __exit fou6_fini(void)
133{
134	ip6_tnl_encap_del_fou_ops();
135}
136
137module_init(fou6_init);
138module_exit(fou6_fini);
139MODULE_AUTHOR("Tom Herbert <therbert@google.com>");
140MODULE_LICENSE("GPL");