]>
git.proxmox.com Git - mirror_ubuntu-zesty-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/netdevice.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 rcu_head rcu_head
;
41 struct dst_entry
*child
;
42 struct net_device
*dev
;
48 #define DST_NOPOLICY 4
50 unsigned long expires
;
52 unsigned short header_len
; /* more space at head required */
53 unsigned short trailer_len
; /* space to reserve at tail */
55 unsigned int rate_tokens
;
56 unsigned long rate_last
; /* rate limiting for ICMP */
58 struct dst_entry
*path
;
60 struct neighbour
*neighbour
;
63 struct xfrm_state
*xfrm
;
67 int (*input
)(struct sk_buff
*);
68 int (*output
)(struct sk_buff
*);
72 u32 metrics
[RTAX_MAX
];
74 #ifdef CONFIG_NET_CLS_ROUTE
82 * Align __refcnt to a 64 bytes alignment
83 * (L1_CACHE_SIZE would be too much)
86 long __pad_to_align_refcnt
[2];
88 long __pad_to_align_refcnt
[1];
91 * __refcnt wants to be on a different cache line from
92 * input/output/ops or performance tanks badly
94 atomic_t __refcnt
; /* client references */
96 unsigned long lastuse
;
98 struct dst_entry
*next
;
99 struct rtable
*rt_next
;
100 struct rt6_info
*rt6_next
;
101 struct dn_route
*dn_next
;
108 unsigned short family
;
112 int (*gc
)(struct dst_ops
*ops
);
113 struct dst_entry
* (*check
)(struct dst_entry
*, __u32 cookie
);
114 void (*destroy
)(struct dst_entry
*);
115 void (*ifdown
)(struct dst_entry
*,
116 struct net_device
*dev
, int how
);
117 struct dst_entry
* (*negative_advice
)(struct dst_entry
*);
118 void (*link_failure
)(struct sk_buff
*);
119 void (*update_pmtu
)(struct dst_entry
*dst
, u32 mtu
);
120 int (*local_out
)(struct sk_buff
*skb
);
123 struct kmem_cache
*kmem_cachep
;
130 dst_metric(const struct dst_entry
*dst
, int metric
)
132 return dst
->metrics
[metric
-1];
135 static inline u32
dst_mtu(const struct dst_entry
*dst
)
137 u32 mtu
= dst_metric(dst
, RTAX_MTU
);
139 * Alexey put it here, so ask him about it :)
145 /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
146 static inline unsigned long dst_metric_rtt(const struct dst_entry
*dst
, int metric
)
148 return msecs_to_jiffies(dst_metric(dst
, metric
));
151 static inline void set_dst_metric_rtt(struct dst_entry
*dst
, int metric
,
154 dst
->metrics
[metric
-1] = jiffies_to_msecs(rtt
);
158 dst_allfrag(const struct dst_entry
*dst
)
160 int ret
= dst_metric(dst
, RTAX_FEATURES
) & RTAX_FEATURE_ALLFRAG
;
161 /* Yes, _exactly_. This is paranoia. */
167 dst_metric_locked(struct dst_entry
*dst
, int metric
)
169 return dst_metric(dst
, RTAX_LOCK
) & (1<<metric
);
172 static inline void dst_hold(struct dst_entry
* dst
)
175 * If your kernel compilation stops here, please check
176 * __pad_to_align_refcnt declaration in struct dst_entry
178 BUILD_BUG_ON(offsetof(struct dst_entry
, __refcnt
) & 63);
179 atomic_inc(&dst
->__refcnt
);
182 static inline void dst_use(struct dst_entry
*dst
, unsigned long time
)
190 struct dst_entry
* dst_clone(struct dst_entry
* dst
)
193 atomic_inc(&dst
->__refcnt
);
197 extern void dst_release(struct dst_entry
*dst
);
198 static inline void skb_dst_drop(struct sk_buff
*skb
)
201 dst_release(skb_dst(skb
));
205 /* Children define the path of the packet through the
206 * Linux networking. Thus, destinations are stackable.
209 static inline struct dst_entry
*dst_pop(struct dst_entry
*dst
)
211 struct dst_entry
*child
= dst_clone(dst
->child
);
217 extern int dst_discard(struct sk_buff
*skb
);
218 extern void * dst_alloc(struct dst_ops
* ops
);
219 extern void __dst_free(struct dst_entry
* dst
);
220 extern struct dst_entry
*dst_destroy(struct dst_entry
* dst
);
222 static inline void dst_free(struct dst_entry
* dst
)
224 if (dst
->obsolete
> 1)
226 if (!atomic_read(&dst
->__refcnt
)) {
227 dst
= dst_destroy(dst
);
234 static inline void dst_rcu_free(struct rcu_head
*head
)
236 struct dst_entry
*dst
= container_of(head
, struct dst_entry
, rcu_head
);
240 static inline void dst_confirm(struct dst_entry
*dst
)
243 neigh_confirm(dst
->neighbour
);
246 static inline void dst_negative_advice(struct dst_entry
**dst_p
)
248 struct dst_entry
* dst
= *dst_p
;
249 if (dst
&& dst
->ops
->negative_advice
)
250 *dst_p
= dst
->ops
->negative_advice(dst
);
253 static inline void dst_link_failure(struct sk_buff
*skb
)
255 struct dst_entry
*dst
= skb_dst(skb
);
256 if (dst
&& dst
->ops
&& dst
->ops
->link_failure
)
257 dst
->ops
->link_failure(skb
);
260 static inline void dst_set_expires(struct dst_entry
*dst
, int timeout
)
262 unsigned long expires
= jiffies
+ timeout
;
267 if (dst
->expires
== 0 || time_before(expires
, dst
->expires
))
268 dst
->expires
= expires
;
271 /* Output packet to network from transport. */
272 static inline int dst_output(struct sk_buff
*skb
)
274 return skb_dst(skb
)->output(skb
);
277 /* Input packet from network to transport. */
278 static inline int dst_input(struct sk_buff
*skb
)
280 return skb_dst(skb
)->input(skb
);
283 static inline struct dst_entry
*dst_check(struct dst_entry
*dst
, u32 cookie
)
286 dst
= dst
->ops
->check(dst
, cookie
);
290 extern void dst_init(void);
292 /* Flags for xfrm_lookup flags argument. */
294 XFRM_LOOKUP_WAIT
= 1 << 0,
295 XFRM_LOOKUP_ICMP
= 1 << 1,
300 static inline int xfrm_lookup(struct net
*net
, struct dst_entry
**dst_p
,
301 struct flowi
*fl
, struct sock
*sk
, int flags
)
305 static inline int __xfrm_lookup(struct net
*net
, struct dst_entry
**dst_p
,
306 struct flowi
*fl
, struct sock
*sk
, int flags
)
311 extern int xfrm_lookup(struct net
*net
, struct dst_entry
**dst_p
,
312 struct flowi
*fl
, struct sock
*sk
, int flags
);
313 extern int __xfrm_lookup(struct net
*net
, struct dst_entry
**dst_p
,
314 struct flowi
*fl
, struct sock
*sk
, int flags
);
318 #endif /* _NET_DST_H */