1#ifndef __NET_LWTUNNEL_H
  2#define __NET_LWTUNNEL_H 1
  3
  4#include <linux/lwtunnel.h>
  5#include <linux/netdevice.h>
  6#include <linux/skbuff.h>
  7#include <linux/types.h>
  8#include <net/route.h>
  9
 10#define LWTUNNEL_HASH_BITS   7
 11#define LWTUNNEL_HASH_SIZE   (1 << LWTUNNEL_HASH_BITS)
 12
 13/* lw tunnel state flags */
 14#define LWTUNNEL_STATE_OUTPUT_REDIRECT	BIT(0)
 15#define LWTUNNEL_STATE_INPUT_REDIRECT	BIT(1)
 16#define LWTUNNEL_STATE_XMIT_REDIRECT	BIT(2)
 17
 18enum {
 19	LWTUNNEL_XMIT_DONE,
 20	LWTUNNEL_XMIT_CONTINUE,
 21};
 22
 23
 24struct lwtunnel_state {
 25	__u16		type;
 26	__u16		flags;
 27	__u16		headroom;
 28	atomic_t	refcnt;
 29	int		(*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb);
 30	int		(*orig_input)(struct sk_buff *);
 31	struct		rcu_head rcu;
 32	__u8            data[0];
 33};
 34
 35struct lwtunnel_encap_ops {
 36	int (*build_state)(struct net_device *dev, struct nlattr *encap,
 37			   unsigned int family, const void *cfg,
 38			   struct lwtunnel_state **ts);
 39	void (*destroy_state)(struct lwtunnel_state *lws);
 40	int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
 41	int (*input)(struct sk_buff *skb);
 42	int (*fill_encap)(struct sk_buff *skb,
 43			  struct lwtunnel_state *lwtstate);
 44	int (*get_encap_size)(struct lwtunnel_state *lwtstate);
 45	int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
 46	int (*xmit)(struct sk_buff *skb);
 47
 48	struct module *owner;
 49};
 50
 51#ifdef CONFIG_LWTUNNEL
 52void lwtstate_free(struct lwtunnel_state *lws);
 53
 54static inline struct lwtunnel_state *
 55lwtstate_get(struct lwtunnel_state *lws)
 56{
 57	if (lws)
 58		atomic_inc(&lws->refcnt);
 59
 60	return lws;
 61}
 62
 63static inline void lwtstate_put(struct lwtunnel_state *lws)
 64{
 65	if (!lws)
 66		return;
 67
 68	if (atomic_dec_and_test(&lws->refcnt))
 69		lwtstate_free(lws);
 70}
 71
 72static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
 73{
 74	if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
 75		return true;
 76
 77	return false;
 78}
 79
 80static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
 81{
 82	if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
 83		return true;
 84
 85	return false;
 86}
 87
 88static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
 89{
 90	if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
 91		return true;
 92
 93	return false;
 94}
 95
 96static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
 97					     unsigned int mtu)
 98{
 99	if ((lwtunnel_xmit_redirect(lwtstate) ||
100	     lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
101		return lwtstate->headroom;
102
103	return 0;
104}
105
106int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
107			   unsigned int num);
108int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
109			   unsigned int num);
110int lwtunnel_valid_encap_type(u16 encap_type);
111int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len);
112int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
113			 struct nlattr *encap,
114			 unsigned int family, const void *cfg,
115			 struct lwtunnel_state **lws);
116int lwtunnel_fill_encap(struct sk_buff *skb,
117			struct lwtunnel_state *lwtstate);
118int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
119struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
120int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
121int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
122int lwtunnel_input(struct sk_buff *skb);
123int lwtunnel_xmit(struct sk_buff *skb);
124
125#else
126
127static inline void lwtstate_free(struct lwtunnel_state *lws)
128{
129}
130
131static inline struct lwtunnel_state *
132lwtstate_get(struct lwtunnel_state *lws)
133{
134	return lws;
135}
136
137static inline void lwtstate_put(struct lwtunnel_state *lws)
138{
139}
140
141static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
142{
143	return false;
144}
145
146static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
147{
148	return false;
149}
150
151static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
152{
153	return false;
154}
155
156static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
157					     unsigned int mtu)
158{
159	return 0;
160}
161
162static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
163					 unsigned int num)
164{
165	return -EOPNOTSUPP;
166
167}
168
169static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
170					 unsigned int num)
171{
172	return -EOPNOTSUPP;
173}
174
175static inline int lwtunnel_valid_encap_type(u16 encap_type)
176{
177	return -EOPNOTSUPP;
178}
179static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len)
180{
181	/* return 0 since we are not walking attr looking for
182	 * RTA_ENCAP_TYPE attribute on nexthops.
183	 */
184	return 0;
185}
186
187static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
188				       struct nlattr *encap,
189				       unsigned int family, const void *cfg,
190				       struct lwtunnel_state **lws)
191{
192	return -EOPNOTSUPP;
193}
194
195static inline int lwtunnel_fill_encap(struct sk_buff *skb,
196				      struct lwtunnel_state *lwtstate)
197{
198	return 0;
199}
200
201static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
202{
203	return 0;
204}
205
206static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
207{
208	return NULL;
209}
210
211static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
212				     struct lwtunnel_state *b)
213{
214	return 0;
215}
216
217static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
218{
219	return -EOPNOTSUPP;
220}
221
222static inline int lwtunnel_input(struct sk_buff *skb)
223{
224	return -EOPNOTSUPP;
225}
226
227static inline int lwtunnel_xmit(struct sk_buff *skb)
228{
229	return -EOPNOTSUPP;
230}
231
232#endif /* CONFIG_LWTUNNEL */
233
234#define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
235
236#endif /* __NET_LWTUNNEL_H */