270 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			270 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #ifndef __NET_LWTUNNEL_H
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| #define __NET_LWTUNNEL_H 1
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| 
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| #include <linux/lwtunnel.h>
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| #include <linux/netdevice.h>
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| #include <linux/skbuff.h>
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| #include <linux/types.h>
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| #include <net/route.h>
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| 
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| #define LWTUNNEL_HASH_BITS   7
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| #define LWTUNNEL_HASH_SIZE   (1 << LWTUNNEL_HASH_BITS)
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| 
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| /* lw tunnel state flags */
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| #define LWTUNNEL_STATE_OUTPUT_REDIRECT	BIT(0)
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| #define LWTUNNEL_STATE_INPUT_REDIRECT	BIT(1)
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| #define LWTUNNEL_STATE_XMIT_REDIRECT	BIT(2)
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| 
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| /* LWTUNNEL_XMIT_CONTINUE should be distinguishable from dst_output return
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|  * values (NET_XMIT_xxx and NETDEV_TX_xxx in linux/netdevice.h) for safety.
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|  */
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| enum {
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| 	LWTUNNEL_XMIT_DONE,
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| 	LWTUNNEL_XMIT_CONTINUE = 0x100,
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| };
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| 
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| 
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| struct lwtunnel_state {
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| 	__u16		type;
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| 	__u16		flags;
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| 	__u16		headroom;
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| 	atomic_t	refcnt;
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| 	int		(*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb);
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| 	int		(*orig_input)(struct sk_buff *);
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| 	struct		rcu_head rcu;
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| 	__u8            data[];
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| };
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| 
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| struct lwtunnel_encap_ops {
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| 	int (*build_state)(struct net *net, struct nlattr *encap,
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| 			   unsigned int family, const void *cfg,
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| 			   struct lwtunnel_state **ts,
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| 			   struct netlink_ext_ack *extack);
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| 	void (*destroy_state)(struct lwtunnel_state *lws);
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| 	int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
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| 	int (*input)(struct sk_buff *skb);
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| 	int (*fill_encap)(struct sk_buff *skb,
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| 			  struct lwtunnel_state *lwtstate);
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| 	int (*get_encap_size)(struct lwtunnel_state *lwtstate);
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| 	int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
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| 	int (*xmit)(struct sk_buff *skb);
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| 
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| 	struct module *owner;
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| };
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| 
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| #ifdef CONFIG_LWTUNNEL
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| 
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| DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled);
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| 
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| void lwtstate_free(struct lwtunnel_state *lws);
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| 
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| static inline struct lwtunnel_state *
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| lwtstate_get(struct lwtunnel_state *lws)
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| {
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| 	if (lws)
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| 		atomic_inc(&lws->refcnt);
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| 
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| 	return lws;
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| }
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| 
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| static inline void lwtstate_put(struct lwtunnel_state *lws)
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| {
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| 	if (!lws)
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| 		return;
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| 
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| 	if (atomic_dec_and_test(&lws->refcnt))
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| 		lwtstate_free(lws);
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| }
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| 
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| static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
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| {
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| 	if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
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| 		return true;
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| 
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| 	return false;
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| }
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| 
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| static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
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| {
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| 	if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
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| 		return true;
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| 
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| 	return false;
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| }
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| 
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| static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
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| {
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| 	if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
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| 		return true;
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| 
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| 	return false;
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| }
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| 
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| static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
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| 					     unsigned int mtu)
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| {
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| 	if ((lwtunnel_xmit_redirect(lwtstate) ||
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| 	     lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
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| 		return lwtstate->headroom;
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| 
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| 	return 0;
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| }
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| 
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| int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
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| 			   unsigned int num);
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| int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
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| 			   unsigned int num);
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| int lwtunnel_valid_encap_type(u16 encap_type,
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| 			      struct netlink_ext_ack *extack);
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| int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
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| 				   struct netlink_ext_ack *extack);
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| int lwtunnel_build_state(struct net *net, u16 encap_type,
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| 			 struct nlattr *encap,
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| 			 unsigned int family, const void *cfg,
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| 			 struct lwtunnel_state **lws,
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| 			 struct netlink_ext_ack *extack);
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| int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate,
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| 			int encap_attr, int encap_type_attr);
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| int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
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| struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
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| int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
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| int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
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| int lwtunnel_input(struct sk_buff *skb);
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| int lwtunnel_xmit(struct sk_buff *skb);
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| int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len,
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| 			  bool ingress);
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| 
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| static inline void lwtunnel_set_redirect(struct dst_entry *dst)
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| {
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| 	if (lwtunnel_output_redirect(dst->lwtstate)) {
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| 		dst->lwtstate->orig_output = dst->output;
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| 		dst->output = lwtunnel_output;
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| 	}
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| 	if (lwtunnel_input_redirect(dst->lwtstate)) {
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| 		dst->lwtstate->orig_input = dst->input;
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| 		dst->input = lwtunnel_input;
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| 	}
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| }
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| #else
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| 
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| static inline void lwtstate_free(struct lwtunnel_state *lws)
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| {
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| }
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| 
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| static inline struct lwtunnel_state *
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| lwtstate_get(struct lwtunnel_state *lws)
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| {
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| 	return lws;
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| }
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| 
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| static inline void lwtstate_put(struct lwtunnel_state *lws)
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| {
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| }
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| 
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| static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
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| {
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| 	return false;
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| }
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| 
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| static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
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| {
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| 	return false;
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| }
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| 
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| static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
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| {
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| 	return false;
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| }
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| 
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| static inline void lwtunnel_set_redirect(struct dst_entry *dst)
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| {
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| }
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| 
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| static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
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| 					     unsigned int mtu)
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| {
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| 	return 0;
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| }
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| 
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| static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
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| 					 unsigned int num)
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| {
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| 	return -EOPNOTSUPP;
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| 
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| }
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| 
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| static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
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| 					 unsigned int num)
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| {
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| 	return -EOPNOTSUPP;
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| }
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| 
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| static inline int lwtunnel_valid_encap_type(u16 encap_type,
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| 					    struct netlink_ext_ack *extack)
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| {
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| 	NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
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| 	return -EOPNOTSUPP;
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| }
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| static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
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| 						 struct netlink_ext_ack *extack)
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| {
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| 	/* return 0 since we are not walking attr looking for
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| 	 * RTA_ENCAP_TYPE attribute on nexthops.
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| 	 */
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| 	return 0;
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| }
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| 
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| static inline int lwtunnel_build_state(struct net *net, u16 encap_type,
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| 				       struct nlattr *encap,
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| 				       unsigned int family, const void *cfg,
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| 				       struct lwtunnel_state **lws,
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| 				       struct netlink_ext_ack *extack)
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| {
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| 	return -EOPNOTSUPP;
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| }
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| 
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| static inline int lwtunnel_fill_encap(struct sk_buff *skb,
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| 				      struct lwtunnel_state *lwtstate,
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| 				      int encap_attr, int encap_type_attr)
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| {
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| 	return 0;
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| }
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| 
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| static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
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| {
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| 	return 0;
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| }
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| 
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| static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
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| {
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| 	return NULL;
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| }
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| 
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| static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
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| 				     struct lwtunnel_state *b)
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| {
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| 	return 0;
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| }
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| 
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| static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
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| {
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| 	return -EOPNOTSUPP;
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| }
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| 
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| static inline int lwtunnel_input(struct sk_buff *skb)
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| {
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| 	return -EOPNOTSUPP;
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| }
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| 
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| static inline int lwtunnel_xmit(struct sk_buff *skb)
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| {
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| 	return -EOPNOTSUPP;
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| }
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| 
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| #endif /* CONFIG_LWTUNNEL */
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| 
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| #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
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| 
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| #endif /* __NET_LWTUNNEL_H */
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