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  
21  struct __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  	IP_TUNNEL_DECLARE_FLAGS(i_flags);
34  	IP_TUNNEL_DECLARE_FLAGS(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 */
46  struct 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  
69  struct 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  
79  extern const struct ip6_tnl_encap_ops __rcu *
80  		ip6tun_encaps[MAX_IPTUN_ENCAP_OPS];
81  
82  int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,
83  			  unsigned int num);
84  int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,
85  			  unsigned int num);
86  int ip6_tnl_encap_setup(struct ip6_tnl *t,
87  			struct ip_tunnel_encap *ipencap);
88  
ip6_encap_hlen(struct ip_tunnel_encap * e)89  static 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  
ip6_tnl_encap(struct sk_buff * skb,struct ip6_tnl * t,u8 * protocol,struct flowi6 * fl6)109  static 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  
132  struct 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  
138  int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
139  		const struct in6_addr *raddr);
140  int 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);
143  int ip6_tnl_xmit_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,
144  		     const struct in6_addr *raddr);
145  int 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);
150  struct net *ip6_tnl_get_link_net(const struct net_device *dev);
151  int ip6_tnl_get_iflink(const struct net_device *dev);
152  int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu);
153  
ip6tunnel_xmit(struct sock * sk,struct sk_buff * skb,struct net_device * dev)154  static 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