1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _NET_IP6_TUNNEL_H
3#define _NET_IP6_TUNNEL_H
4
5#include <linux/ipv6.h>
6#include <linux/netdevice.h>
7#include <linux/if_tunnel.h>
8#include <linux/ip6_tunnel.h>
9#include <net/ip_tunnels.h>
10#include <net/dst_cache.h>
11
12#define IP6TUNNEL_ERR_TIMEO (30*HZ)
13
14/* capable of sending packets */
15#define IP6_TNL_F_CAP_XMIT 0x10000
16/* capable of receiving packets */
17#define IP6_TNL_F_CAP_RCV 0x20000
18/* determine capability on a per-packet basis */
19#define IP6_TNL_F_CAP_PER_PACKET 0x40000
20
21struct __ip6_tnl_parm {
22	char name[IFNAMSIZ];	/* name of tunnel device */
23	int link;		/* ifindex of underlying L2 interface */
24	__u8 proto;		/* tunnel protocol */
25	__u8 encap_limit;	/* encapsulation limit for tunnel */
26	__u8 hop_limit;		/* hop limit for tunnel */
27	bool collect_md;
28	__be32 flowinfo;	/* traffic class and flowlabel for tunnel */
29	__u32 flags;		/* tunnel flags */
30	struct in6_addr laddr;	/* local tunnel end-point address */
31	struct in6_addr raddr;	/* remote tunnel end-point address */
32
33	__be16			i_flags;
34	__be16			o_flags;
35	__be32			i_key;
36	__be32			o_key;
37
38	__u32			fwmark;
39	__u32			index;	/* ERSPAN type II index */
40	__u8			erspan_ver;	/* ERSPAN version */
41	__u8			dir;	/* direction */
42	__u16			hwid;	/* hwid */
43};
44
45/* IPv6 tunnel */
46struct ip6_tnl {
47	struct ip6_tnl __rcu *next;	/* next tunnel in list */
48	struct net_device *dev;	/* virtual device associated with tunnel */
49	struct net *net;	/* netns for packet i/o */
50	struct __ip6_tnl_parm parms;	/* tunnel configuration parameters */
51	struct flowi fl;	/* flowi template for xmit */
52	struct dst_cache dst_cache;	/* cached dst */
53	struct gro_cells gro_cells;
54
55	int err_count;
56	unsigned long err_time;
57
58	/* These fields used only by GRE */
59	__u32 i_seqno;	/* The last seen seqno	*/
60	atomic_t o_seqno;	/* The last output seqno */
61	int hlen;       /* tun_hlen + encap_hlen */
62	int tun_hlen;	/* Precalculated header length */
63	int encap_hlen; /* Encap header length (FOU,GUE) */
64	struct ip_tunnel_encap encap;
65	int mlink;
66};
67
68struct ip6_tnl_encap_ops {
69	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
70	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
71			    u8 *protocol, struct flowi6 *fl6);
72	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
73			   u8 type, u8 code, int offset, __be32 info);
74};
75
76#ifdef CONFIG_INET
77
78extern const struct ip6_tnl_encap_ops __rcu *
79		ip6tun_encaps[MAX_IPTUN_ENCAP_OPS];
80
81int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
82			  unsigned int num);
83int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
84			  unsigned int num);
85int ip6_tnl_encap_setup(struct ip6_tnl *t,
86			struct ip_tunnel_encap *ipencap);
87
88static inline int ip6_encap_hlen(struct ip_tunnel_encap *e)
89{
90	const struct ip6_tnl_encap_ops *ops;
91	int hlen = -EINVAL;
92
93	if (e->type == TUNNEL_ENCAP_NONE)
94		return 0;
95
96	if (e->type >= MAX_IPTUN_ENCAP_OPS)
97		return -EINVAL;
98
99	rcu_read_lock();
100	ops = rcu_dereference(ip6tun_encaps[e->type]);
101	if (likely(ops && ops->encap_hlen))
102		hlen = ops->encap_hlen(e);
103	rcu_read_unlock();
104
105	return hlen;
106}
107
108static inline int ip6_tnl_encap(struct sk_buff *skb, struct ip6_tnl *t,
109				u8 *protocol, struct flowi6 *fl6)
110{
111	const struct ip6_tnl_encap_ops *ops;
112	int ret = -EINVAL;
113
114	if (t->encap.type == TUNNEL_ENCAP_NONE)
115		return 0;
116
117	if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
118		return -EINVAL;
119
120	rcu_read_lock();
121	ops = rcu_dereference(ip6tun_encaps[t->encap.type]);
122	if (likely(ops && ops->build_header))
123		ret = ops->build_header(skb, &t->encap, protocol, fl6);
124	rcu_read_unlock();
125
126	return ret;
127}
128
129/* Tunnel encapsulation limit destination sub-option */
130
131struct ipv6_tlv_tnl_enc_lim {
132	__u8 type;		/* type-code for option         */
133	__u8 length;		/* option length                */
134	__u8 encap_limit;	/* tunnel encapsulation limit   */
135} __packed;
136
137int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
138		const struct in6_addr *raddr);
139int ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
140		const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
141		bool log_ecn_error);
142int ip6_tnl_xmit_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
143		     const struct in6_addr *raddr);
144int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
145		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu, __u8 proto);
146__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw);
147__u32 ip6_tnl_get_cap(struct ip6_tnl *t, const struct in6_addr *laddr,
148			     const struct in6_addr *raddr);
149struct net *ip6_tnl_get_link_net(const struct net_device *dev);
150int ip6_tnl_get_iflink(const struct net_device *dev);
151int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu);
152
153static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
154				  struct net_device *dev)
155{
156	int pkt_len, err;
157
158	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
159	pkt_len = skb->len - skb_inner_network_offset(skb);
160	err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb);
161
162	if (dev) {
163		if (unlikely(net_xmit_eval(err)))
164			pkt_len = -1;
165		iptunnel_xmit_stats(dev, pkt_len);
166	}
167}
168#endif
169#endif
170