/* SPDX-License-Identifier: GPL-2.0 */#ifndef _NET_IP6_TUNNEL_H#define _NET_IP6_TUNNEL_H #include <linux/ipv6.h>#include <linux/netdevice.h>#include <linux/if_tunnel.h>#include <linux/ip6_tunnel.h>#include <net/ip_tunnels.h>#include <net/dst_cache.h> #define IP6TUNNEL_ERR_TIMEO (30*HZ) /* capable of sending packets */#define IP6_TNL_F_CAP_XMIT 0x10000/* capable of receiving packets */#define IP6_TNL_F_CAP_RCV 0x20000/* determine capability on a per-packet basis */#define IP6_TNL_F_CAP_PER_PACKET 0x40000 struct __ip6_tnl_parm {	char name[IFNAMSIZ];	/* name of tunnel device */	int link;		/* ifindex of underlying L2 interface */	__u8 proto;		/* tunnel protocol */	__u8 encap_limit;	/* encapsulation limit for tunnel */	__u8 hop_limit;		/* hop limit for tunnel */	bool collect_md;	__be32 flowinfo;	/* traffic class and flowlabel for tunnel */	__u32 flags;		/* tunnel flags */	struct in6_addr laddr;	/* local tunnel end-point address */	struct in6_addr raddr;	/* remote tunnel end-point address */ 	IP_TUNNEL_DECLARE_FLAGS(i_flags);	IP_TUNNEL_DECLARE_FLAGS(o_flags);	__be32			i_key;	__be32			o_key; 	__u32			fwmark;	__u32			index;	/* ERSPAN type II index */	__u8			erspan_ver;	/* ERSPAN version */	__u8			dir;	/* direction */	__u16			hwid;	/* hwid */}; /* IPv6 tunnel */struct ip6_tnl {	struct ip6_tnl __rcu *next;	/* next tunnel in list */	struct net_device *dev;	/* virtual device associated with tunnel */	netdevice_tracker dev_tracker;	struct net *net;	/* netns for packet i/o */	struct __ip6_tnl_parm parms;	/* tunnel configuration parameters */	struct flowi fl;	/* flowi template for xmit */	struct dst_cache dst_cache;	/* cached dst */	struct gro_cells gro_cells; 	int err_count;	unsigned long err_time; 	/* These fields used only by GRE */	__u32 i_seqno;	/* The last seen seqno	*/	atomic_t o_seqno;	/* The last output seqno */	int hlen;       /* tun_hlen + encap_hlen */	int tun_hlen;	/* Precalculated header length */	int encap_hlen; /* Encap header length (FOU,GUE) */	struct ip_tunnel_encap encap;	int mlink;}; struct ip6_tnl_encap_ops {	size_t (*encap_hlen)(struct ip_tunnel_encap *e);	int (*build_header)(struct sk_buff *skb, struct ip_tunnel_encap *e,			    u8 *protocol, struct flowi6 *fl6);	int (*err_handler)(struct sk_buff *skb, struct inet6_skb_parm *opt,			   u8 type, u8 code, int offset, __be32 info);}; #ifdef CONFIG_INET extern const struct ip6_tnl_encap_ops __rcu *		ip6tun_encaps[MAX_IPTUN_ENCAP_OPS]; int ip6_tnl_encap_add_ops(const struct ip6_tnl_encap_ops *ops,			  unsigned int num);int ip6_tnl_encap_del_ops(const struct ip6_tnl_encap_ops *ops,			  unsigned int num);int ip6_tnl_encap_setup(struct ip6_tnl *t,			struct ip_tunnel_encap *ipencap); static inline int ip6_encap_hlen(struct ip_tunnel_encap *e){	const struct ip6_tnl_encap_ops *ops;	int hlen = -EINVAL; 	if (e->type == TUNNEL_ENCAP_NONE)		return 0; 	if (e->type >= MAX_IPTUN_ENCAP_OPS)		return -EINVAL; 	rcu_read_lock();	ops = rcu_dereference(ip6tun_encaps[e->type]);	if (likely(ops && ops->encap_hlen))		hlen = ops->encap_hlen(e);	rcu_read_unlock(); 	return hlen;} static inline int ip6_tnl_encap(struct sk_buff *skb, struct ip6_tnl *t,				u8 *protocol, struct flowi6 *fl6){	const struct ip6_tnl_encap_ops *ops;	int ret = -EINVAL; 	if (t->encap.type == TUNNEL_ENCAP_NONE)		return 0; 	if (t->encap.type >= MAX_IPTUN_ENCAP_OPS)		return -EINVAL; 	rcu_read_lock();	ops = rcu_dereference(ip6tun_encaps[t->encap.type]);	if (likely(ops && ops->build_header))		ret = ops->build_header(skb, &t->encap, protocol, fl6);	rcu_read_unlock(); 	return ret;} /* Tunnel encapsulation limit destination sub-option */ struct ipv6_tlv_tnl_enc_lim {	__u8 type;		/* type-code for option         */	__u8 length;		/* option length                */	__u8 encap_limit;	/* tunnel encapsulation limit   */} __packed; int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,		const struct in6_addr *raddr);int ip6_tnl_rcv(struct ip6_tnl *tunnel, struct sk_buff *skb,		const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst,		bool log_ecn_error);int ip6_tnl_xmit_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,		     const struct in6_addr *raddr);int ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev, __u8 dsfield,		 struct flowi6 *fl6, int encap_limit, __u32 *pmtu, __u8 proto);__u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw);__u32 ip6_tnl_get_cap(struct ip6_tnl *t, const struct in6_addr *laddr,			     const struct in6_addr *raddr);struct net *ip6_tnl_get_link_net(const struct net_device *dev);int ip6_tnl_get_iflink(const struct net_device *dev);int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu); static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,				  struct net_device *dev, u16 ip6cb_flags){	int pkt_len, err; 	if (unlikely(dev_recursion_level() > IP_TUNNEL_RECURSION_LIMIT)) {		if (dev) {			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",					     dev->name);			DEV_STATS_INC(dev, tx_errors);		}		kfree_skb_reason(skb, SKB_DROP_REASON_RECURSION_LIMIT);		return;	} 	dev_xmit_recursion_inc(); 	memset(skb->cb, 0, sizeof(struct inet6_skb_parm));	IP6CB(skb)->flags = ip6cb_flags;	pkt_len = skb->len - skb_inner_network_offset(skb);	err = ip6_local_out(skb_dst_dev_net(skb), sk, skb); 	if (dev) {		if (unlikely(net_xmit_eval(err)))			pkt_len = -1;		iptunnel_xmit_stats(dev, pkt_len);	} 	dev_xmit_recursion_dec();}#endif#endif