include/net/ip6_tunnel.h

Source file repositories/reference/linux-study-clean/include/net/ip6_tunnel.h

File Facts

System
Linux kernel
Corpus path
include/net/ip6_tunnel.h
Extension
.h
Size
5552 bytes
Lines
186
Domain
Networking Core
Bucket
Sockets, Protocols, Packet Path, And Network Policy
Inferred role
Networking Core: implementation source
Status
source implementation candidate

Why This File Exists

Networking stack implementation surface: socket APIs, protocol dispatch, packet flow, routing, filtering, and network namespaces.

Dependency Surface

Detected Declarations

Annotated Snippet

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)

Annotation

Implementation Notes