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