#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> #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 */	__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 */ 	__be16			i_flags;	__be16			o_flags;	__be32			i_key;	__be32			o_key;}; /* IPv6 tunnel */struct ip6_tnl {	struct ip6_tnl __rcu *next;	/* next tunnel in list */	struct net_device *dev;	/* virtual device associated with tunnel */	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_entry *dst_cache;    /* cached dst */	u32 dst_cookie; 	int err_count;	unsigned long err_time; 	/* These fields used only by GRE */	__u32 i_seqno;	/* The last seen seqno	*/	__u32 o_seqno;	/* The last output seqno */	int hlen;       /* Precalculated GRE header length */	int mlink;}; /* 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; struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t);void ip6_tnl_dst_reset(struct ip6_tnl *t);void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst);int ip6_tnl_rcv_ctl(struct ip6_tnl *t, const struct in6_addr *laddr,		const struct in6_addr *raddr);int ip6_tnl_xmit_ctl(struct ip6_tnl *t);__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); static inline void ip6tunnel_xmit(struct sk_buff *skb, struct net_device *dev){	struct net_device_stats *stats = &dev->stats;	int pkt_len, err; 	pkt_len = skb->len;	err = ip6_local_out(skb); 	if (net_xmit_eval(err) == 0) {		struct pcpu_tstats *tstats = this_cpu_ptr(dev->tstats);		u64_stats_update_begin(&tstats->syncp);		tstats->tx_bytes += pkt_len;		tstats->tx_packets++;		u64_stats_update_end(&tstats->syncp);	} else {		stats->tx_errors++;		stats->tx_aborted_errors++;	}}#endif