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	netdevice_tracker dev_tracker;
50	struct net *net;	/* netns for packet i/o */
51	struct __ip6_tnl_parm parms;	/* tunnel configuration parameters */
52	struct flowi fl;	/* flowi template for xmit */
53	struct dst_cache dst_cache;	/* cached dst */
54	struct gro_cells gro_cells;
55
56	int err_count;
57	unsigned long err_time;
58
59	/* These fields used only by GRE */
60	__u32 i_seqno;	/* The last seen seqno	*/
61	atomic_t o_seqno;	/* The last output seqno */
62	int hlen;       /* tun_hlen + encap_hlen */
63	int tun_hlen;	/* Precalculated header length */
64	int encap_hlen; /* Encap header length (FOU,GUE) */
65	struct ip_tunnel_encap encap;
66	int mlink;
67};
68
69struct ip6_tnl_encap_ops {
70	size_t (*encap_hlen)(struct ip_tunnel_encap *e);
71	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,
72			    u8 *protocol, struct flowi6 *fl6);
73	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,
74			   u8 type, u8 code, int offset, __be32 info);
75};
76
77#ifdef CONFIG_INET
78
79extern const struct ip6_tnl_encap_ops __rcu *
80		ip6tun_encaps[MAX_IPTUN_ENCAP_OPS];
81
82int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
83			  unsigned int num);
84int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
85			  unsigned int num);
86int ip6_tnl_encap_setup(struct ip6_tnl *t,
87			struct ip_tunnel_encap *ipencap);
88
89static inline int ip6_encap_hlen(struct ip_tunnel_encap *e)
90{
91	const struct ip6_tnl_encap_ops *ops;
92	int hlen = -EINVAL;
93
94	if (e->type == TUNNEL_ENCAP_NONE)
95		return 0;
96
97	if (e->type >= MAX_IPTUN_ENCAP_OPS)
98		return -EINVAL;
99
100	rcu_read_lock();
101	ops = rcu_dereference(ip6tun_encaps[e->type]);
102	if (likely(ops && ops->encap_hlen))
103		hlen = ops->encap_hlen(e);
104	rcu_read_unlock();
105
106	return hlen;
107}
108
109static inline int ip6_tnl_encap(struct sk_buff *skb, struct ip6_tnl *t,
110				u8 *protocol, struct flowi6 *fl6)
111{
112	const struct ip6_tnl_encap_ops *ops;
113	int ret = -EINVAL;
114
115	if (t->encap.type == TUNNEL_ENCAP_NONE)
116		return 0;
117
118	if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)
119		return -EINVAL;
120
121	rcu_read_lock();
122	ops = rcu_dereference(ip6tun_encaps[t->encap.type]);
123	if (likely(ops && ops->build_header))
124		ret = ops->build_header(skb, &t->encap, protocol, fl6);
125	rcu_read_unlock();
126
127	return ret;
128}
129
130/* Tunnel encapsulation limit destination sub-option */
131
132struct ipv6_tlv_tnl_enc_lim {
133	__u8 type;		/* type-code for option         */
134	__u8 length;		/* option length                */
135	__u8 encap_limit;	/* tunnel encapsulation limit   */
136} __packed;
137
138int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
139		const struct in6_addr *raddr);
140int ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,
141		const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,
142		bool log_ecn_error);
143int ip6_tnl_xmit_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
144		     const struct in6_addr *raddr);
145int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,
146		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu, __u8 proto);
147__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw);
148__u32 ip6_tnl_get_cap(struct ip6_tnl *t, const struct in6_addr *laddr,
149			     const struct in6_addr *raddr);
150struct net *ip6_tnl_get_link_net(const struct net_device *dev);
151int ip6_tnl_get_iflink(const struct net_device *dev);
152int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu);
153
154static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
155				  struct net_device *dev)
156{
157	int pkt_len, err;
158
159	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
160	pkt_len = skb->len - skb_inner_network_offset(skb);
161	err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb);
162
163	if (dev) {
164		if (unlikely(net_xmit_eval(err)))
165			pkt_len = -1;
166		iptunnel_xmit_stats(dev, pkt_len);
167	}
168}
169#endif
170#endif
171