]>
git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/blob - include/net/dst.h
2 * net/dst.h Protocol independent destination cache definitions.
4 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
11 #include <linux/config.h>
12 #include <linux/rtnetlink.h>
13 #include <linux/rcupdate.h>
14 #include <linux/jiffies.h>
15 #include <net/neighbour.h>
16 #include <asm/processor.h>
19 * 0 - no debugging messages
20 * 1 - rare events and bugs (default)
23 #define RT_CACHE_DEBUG 0
25 #define DST_GC_MIN (HZ/10)
26 #define DST_GC_INC (HZ/2)
27 #define DST_GC_MAX (120*HZ)
29 /* Each dst_entry has reference count and sits in some parent list(s).
30 * When it is removed from parent list, it is "freed" (dst_free).
31 * After this it enters dead state (dst->obsolete > 0) and if its refcnt
32 * is zero, it can be destroyed immediately, otherwise it is added
33 * to gc list and garbage collector periodically checks the refcnt.
40 struct dst_entry
*next
;
41 atomic_t __refcnt
; /* client references */
43 struct dst_entry
*child
;
44 struct net_device
*dev
;
49 #define DST_NOPOLICY 4
51 #define DST_BALANCED 0x10
52 unsigned long lastuse
;
53 unsigned long expires
;
55 unsigned short header_len
; /* more space at head required */
56 unsigned short trailer_len
; /* space to reserve at tail */
58 u32 metrics
[RTAX_MAX
];
59 struct dst_entry
*path
;
61 unsigned long rate_last
; /* rate limiting for ICMP */
62 unsigned long rate_tokens
;
66 struct neighbour
*neighbour
;
68 struct xfrm_state
*xfrm
;
70 int (*input
)(struct sk_buff
*);
71 int (*output
)(struct sk_buff
*);
73 #ifdef CONFIG_NET_CLS_ROUTE
78 struct rcu_head rcu_head
;
86 unsigned short family
;
87 unsigned short protocol
;
91 struct dst_entry
* (*check
)(struct dst_entry
*, __u32 cookie
);
92 void (*destroy
)(struct dst_entry
*);
93 void (*ifdown
)(struct dst_entry
*,
94 struct net_device
*dev
, int how
);
95 struct dst_entry
* (*negative_advice
)(struct dst_entry
*);
96 void (*link_failure
)(struct sk_buff
*);
97 void (*update_pmtu
)(struct dst_entry
*dst
, u32 mtu
);
98 int (*get_mss
)(struct dst_entry
*dst
, u32 mtu
);
102 kmem_cache_t
*kmem_cachep
;
108 dst_metric(const struct dst_entry
*dst
, int metric
)
110 return dst
->metrics
[metric
-1];
113 static inline u32
dst_mtu(const struct dst_entry
*dst
)
115 u32 mtu
= dst_metric(dst
, RTAX_MTU
);
117 * Alexey put it here, so ask him about it :)
124 dst_allfrag(const struct dst_entry
*dst
)
126 int ret
= dst_metric(dst
, RTAX_FEATURES
) & RTAX_FEATURE_ALLFRAG
;
127 /* Yes, _exactly_. This is paranoia. */
133 dst_metric_locked(struct dst_entry
*dst
, int metric
)
135 return dst_metric(dst
, RTAX_LOCK
) & (1<<metric
);
138 static inline void dst_hold(struct dst_entry
* dst
)
140 atomic_inc(&dst
->__refcnt
);
144 struct dst_entry
* dst_clone(struct dst_entry
* dst
)
147 atomic_inc(&dst
->__refcnt
);
152 void dst_release(struct dst_entry
* dst
)
155 WARN_ON(atomic_read(&dst
->__refcnt
) < 1);
156 smp_mb__before_atomic_dec();
157 atomic_dec(&dst
->__refcnt
);
161 /* Children define the path of the packet through the
162 * Linux networking. Thus, destinations are stackable.
165 static inline struct dst_entry
*dst_pop(struct dst_entry
*dst
)
167 struct dst_entry
*child
= dst_clone(dst
->child
);
173 extern void * dst_alloc(struct dst_ops
* ops
);
174 extern void __dst_free(struct dst_entry
* dst
);
175 extern struct dst_entry
*dst_destroy(struct dst_entry
* dst
);
177 static inline void dst_free(struct dst_entry
* dst
)
179 if (dst
->obsolete
> 1)
181 if (!atomic_read(&dst
->__refcnt
)) {
182 dst
= dst_destroy(dst
);
189 static inline void dst_rcu_free(struct rcu_head
*head
)
191 struct dst_entry
*dst
= container_of(head
, struct dst_entry
, rcu_head
);
195 static inline void dst_confirm(struct dst_entry
*dst
)
198 neigh_confirm(dst
->neighbour
);
201 static inline void dst_negative_advice(struct dst_entry
**dst_p
)
203 struct dst_entry
* dst
= *dst_p
;
204 if (dst
&& dst
->ops
->negative_advice
)
205 *dst_p
= dst
->ops
->negative_advice(dst
);
208 static inline void dst_link_failure(struct sk_buff
*skb
)
210 struct dst_entry
* dst
= skb
->dst
;
211 if (dst
&& dst
->ops
&& dst
->ops
->link_failure
)
212 dst
->ops
->link_failure(skb
);
215 static inline void dst_set_expires(struct dst_entry
*dst
, int timeout
)
217 unsigned long expires
= jiffies
+ timeout
;
222 if (dst
->expires
== 0 || time_before(expires
, dst
->expires
))
223 dst
->expires
= expires
;
226 /* Output packet to network from transport. */
227 static inline int dst_output(struct sk_buff
*skb
)
232 err
= skb
->dst
->output(skb
);
234 if (likely(err
== 0))
236 if (unlikely(err
!= NET_XMIT_BYPASS
))
241 /* Input packet from network to transport. */
242 static inline int dst_input(struct sk_buff
*skb
)
247 err
= skb
->dst
->input(skb
);
249 if (likely(err
== 0))
251 /* Oh, Jamal... Seems, I will not forgive you this mess. :-) */
252 if (unlikely(err
!= NET_XMIT_BYPASS
))
257 static inline struct dst_entry
*dst_check(struct dst_entry
*dst
, u32 cookie
)
260 dst
= dst
->ops
->check(dst
, cookie
);
264 extern void dst_init(void);
268 static inline int xfrm_lookup(struct dst_entry
**dst_p
, struct flowi
*fl
,
269 struct sock
*sk
, int flags
)
274 extern int xfrm_lookup(struct dst_entry
**dst_p
, struct flowi
*fl
,
275 struct sock
*sk
, int flags
);
279 #endif /* _NET_DST_H */