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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 <net/dst_ops.h>
12 #include <linux/netdevice.h>
13 #include <linux/rtnetlink.h>
14 #include <linux/rcupdate.h>
15 #include <linux/bug.h>
16 #include <linux/jiffies.h>
17 #include <net/neighbour.h>
18 #include <asm/processor.h>
20 #define DST_GC_MIN (HZ/10)
21 #define DST_GC_INC (HZ/2)
22 #define DST_GC_MAX (120*HZ)
24 /* Each dst_entry has reference count and sits in some parent list(s).
25 * When it is removed from parent list, it is "freed" (dst_free).
26 * After this it enters dead state (dst->obsolete > 0) and if its refcnt
27 * is zero, it can be destroyed immediately, otherwise it is added
28 * to gc list and garbage collector periodically checks the refcnt.
34 struct rcu_head rcu_head
;
35 struct dst_entry
*child
;
36 struct net_device
*dev
;
38 unsigned long _metrics
;
40 unsigned long expires
;
41 /* point to where the dst_entry copied from */
42 struct dst_entry
*from
;
44 struct dst_entry
*path
;
45 struct neighbour __rcu
*_neighbour
;
47 struct xfrm_state
*xfrm
;
51 int (*input
)(struct sk_buff
*);
52 int (*output
)(struct sk_buff
*);
55 #define DST_HOST 0x0001
56 #define DST_NOXFRM 0x0002
57 #define DST_NOPOLICY 0x0004
58 #define DST_NOHASH 0x0008
59 #define DST_NOCACHE 0x0010
60 #define DST_NOCOUNT 0x0020
61 #define DST_NOPEER 0x0040
62 #define DST_FAKE_RTABLE 0x0080
63 #define DST_XFRM_TUNNEL 0x0100
67 unsigned short header_len
; /* more space at head required */
68 unsigned short trailer_len
; /* space to reserve at tail */
69 #ifdef CONFIG_IP_ROUTE_CLASSID
76 * Align __refcnt to a 64 bytes alignment
77 * (L1_CACHE_SIZE would be too much)
80 long __pad_to_align_refcnt
[2];
83 * __refcnt wants to be on a different cache line from
84 * input/output/ops or performance tanks badly
86 atomic_t __refcnt
; /* client references */
88 unsigned long lastuse
;
90 struct dst_entry
*next
;
91 struct rtable __rcu
*rt_next
;
92 struct rt6_info
*rt6_next
;
93 struct dn_route __rcu
*dn_next
;
97 static inline struct neighbour
*dst_get_neighbour_noref(struct dst_entry
*dst
)
99 return rcu_dereference(dst
->_neighbour
);
102 static inline struct neighbour
*dst_get_neighbour_noref_raw(struct dst_entry
*dst
)
104 return rcu_dereference_raw(dst
->_neighbour
);
107 static inline void dst_set_neighbour(struct dst_entry
*dst
, struct neighbour
*neigh
)
109 rcu_assign_pointer(dst
->_neighbour
, neigh
);
112 extern u32
*dst_cow_metrics_generic(struct dst_entry
*dst
, unsigned long old
);
113 extern const u32 dst_default_metrics
[RTAX_MAX
];
115 #define DST_METRICS_READ_ONLY 0x1UL
116 #define __DST_METRICS_PTR(Y) \
117 ((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
118 #define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
120 static inline bool dst_metrics_read_only(const struct dst_entry
*dst
)
122 return dst
->_metrics
& DST_METRICS_READ_ONLY
;
125 extern void __dst_destroy_metrics_generic(struct dst_entry
*dst
, unsigned long old
);
127 static inline void dst_destroy_metrics_generic(struct dst_entry
*dst
)
129 unsigned long val
= dst
->_metrics
;
130 if (!(val
& DST_METRICS_READ_ONLY
))
131 __dst_destroy_metrics_generic(dst
, val
);
134 static inline u32
*dst_metrics_write_ptr(struct dst_entry
*dst
)
136 unsigned long p
= dst
->_metrics
;
140 if (p
& DST_METRICS_READ_ONLY
)
141 return dst
->ops
->cow_metrics(dst
, p
);
142 return __DST_METRICS_PTR(p
);
145 /* This may only be invoked before the entry has reached global
148 static inline void dst_init_metrics(struct dst_entry
*dst
,
149 const u32
*src_metrics
,
152 dst
->_metrics
= ((unsigned long) src_metrics
) |
153 (read_only
? DST_METRICS_READ_ONLY
: 0);
156 static inline void dst_copy_metrics(struct dst_entry
*dest
, const struct dst_entry
*src
)
158 u32
*dst_metrics
= dst_metrics_write_ptr(dest
);
161 u32
*src_metrics
= DST_METRICS_PTR(src
);
163 memcpy(dst_metrics
, src_metrics
, RTAX_MAX
* sizeof(u32
));
167 static inline u32
*dst_metrics_ptr(struct dst_entry
*dst
)
169 return DST_METRICS_PTR(dst
);
173 dst_metric_raw(const struct dst_entry
*dst
, const int metric
)
175 u32
*p
= DST_METRICS_PTR(dst
);
181 dst_metric(const struct dst_entry
*dst
, const int metric
)
183 WARN_ON_ONCE(metric
== RTAX_HOPLIMIT
||
184 metric
== RTAX_ADVMSS
||
186 return dst_metric_raw(dst
, metric
);
190 dst_metric_advmss(const struct dst_entry
*dst
)
192 u32 advmss
= dst_metric_raw(dst
, RTAX_ADVMSS
);
195 advmss
= dst
->ops
->default_advmss(dst
);
200 static inline void dst_metric_set(struct dst_entry
*dst
, int metric
, u32 val
)
202 u32
*p
= dst_metrics_write_ptr(dst
);
209 dst_feature(const struct dst_entry
*dst
, u32 feature
)
211 return dst_metric(dst
, RTAX_FEATURES
) & feature
;
214 static inline u32
dst_mtu(const struct dst_entry
*dst
)
216 return dst
->ops
->mtu(dst
);
219 /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
220 static inline unsigned long dst_metric_rtt(const struct dst_entry
*dst
, int metric
)
222 return msecs_to_jiffies(dst_metric(dst
, metric
));
225 static inline void set_dst_metric_rtt(struct dst_entry
*dst
, int metric
,
228 dst_metric_set(dst
, metric
, jiffies_to_msecs(rtt
));
232 dst_allfrag(const struct dst_entry
*dst
)
234 int ret
= dst_feature(dst
, RTAX_FEATURE_ALLFRAG
);
239 dst_metric_locked(const struct dst_entry
*dst
, int metric
)
241 return dst_metric(dst
, RTAX_LOCK
) & (1<<metric
);
244 static inline void dst_hold(struct dst_entry
* dst
)
247 * If your kernel compilation stops here, please check
248 * __pad_to_align_refcnt declaration in struct dst_entry
250 BUILD_BUG_ON(offsetof(struct dst_entry
, __refcnt
) & 63);
251 atomic_inc(&dst
->__refcnt
);
254 static inline void dst_use(struct dst_entry
*dst
, unsigned long time
)
261 static inline void dst_use_noref(struct dst_entry
*dst
, unsigned long time
)
268 struct dst_entry
* dst_clone(struct dst_entry
* dst
)
271 atomic_inc(&dst
->__refcnt
);
275 extern void dst_release(struct dst_entry
*dst
);
277 static inline void refdst_drop(unsigned long refdst
)
279 if (!(refdst
& SKB_DST_NOREF
))
280 dst_release((struct dst_entry
*)(refdst
& SKB_DST_PTRMASK
));
284 * skb_dst_drop - drops skb dst
287 * Drops dst reference count if a reference was taken.
289 static inline void skb_dst_drop(struct sk_buff
*skb
)
291 if (skb
->_skb_refdst
) {
292 refdst_drop(skb
->_skb_refdst
);
293 skb
->_skb_refdst
= 0UL;
297 static inline void skb_dst_copy(struct sk_buff
*nskb
, const struct sk_buff
*oskb
)
299 nskb
->_skb_refdst
= oskb
->_skb_refdst
;
300 if (!(nskb
->_skb_refdst
& SKB_DST_NOREF
))
301 dst_clone(skb_dst(nskb
));
305 * skb_dst_force - makes sure skb dst is refcounted
308 * If dst is not yet refcounted, let's do it
310 static inline void skb_dst_force(struct sk_buff
*skb
)
312 if (skb_dst_is_noref(skb
)) {
313 WARN_ON(!rcu_read_lock_held());
314 skb
->_skb_refdst
&= ~SKB_DST_NOREF
;
315 dst_clone(skb_dst(skb
));
321 * __skb_tunnel_rx - prepare skb for rx reinsert
323 * @dev: tunnel device
325 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
326 * so make some cleanups. (no accounting done)
328 static inline void __skb_tunnel_rx(struct sk_buff
*skb
, struct net_device
*dev
)
333 * Clear rxhash so that we can recalulate the hash for the
334 * encapsulated packet, unless we have already determine the hash
335 * over the L4 4-tuple.
339 skb_set_queue_mapping(skb
, 0);
345 * skb_tunnel_rx - prepare skb for rx reinsert
347 * @dev: tunnel device
349 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
350 * so make some cleanups, and perform accounting.
351 * Note: this accounting is not SMP safe.
353 static inline void skb_tunnel_rx(struct sk_buff
*skb
, struct net_device
*dev
)
355 /* TODO : stats should be SMP safe */
356 dev
->stats
.rx_packets
++;
357 dev
->stats
.rx_bytes
+= skb
->len
;
358 __skb_tunnel_rx(skb
, dev
);
361 /* Children define the path of the packet through the
362 * Linux networking. Thus, destinations are stackable.
365 static inline struct dst_entry
*skb_dst_pop(struct sk_buff
*skb
)
367 struct dst_entry
*child
= dst_clone(skb_dst(skb
)->child
);
373 extern int dst_discard(struct sk_buff
*skb
);
374 extern void *dst_alloc(struct dst_ops
* ops
, struct net_device
*dev
,
375 int initial_ref
, int initial_obsolete
, int flags
);
376 extern void __dst_free(struct dst_entry
* dst
);
377 extern struct dst_entry
*dst_destroy(struct dst_entry
* dst
);
379 static inline void dst_free(struct dst_entry
* dst
)
381 if (dst
->obsolete
> 1)
383 if (!atomic_read(&dst
->__refcnt
)) {
384 dst
= dst_destroy(dst
);
391 static inline void dst_rcu_free(struct rcu_head
*head
)
393 struct dst_entry
*dst
= container_of(head
, struct dst_entry
, rcu_head
);
397 static inline void dst_confirm(struct dst_entry
*dst
)
403 n
= dst_get_neighbour_noref(dst
);
409 static inline struct neighbour
*dst_neigh_lookup(const struct dst_entry
*dst
, const void *daddr
)
411 return dst
->ops
->neigh_lookup(dst
, daddr
);
414 static inline void dst_link_failure(struct sk_buff
*skb
)
416 struct dst_entry
*dst
= skb_dst(skb
);
417 if (dst
&& dst
->ops
&& dst
->ops
->link_failure
)
418 dst
->ops
->link_failure(skb
);
421 static inline void dst_set_expires(struct dst_entry
*dst
, int timeout
)
423 unsigned long expires
= jiffies
+ timeout
;
428 if (dst
->expires
== 0 || time_before(expires
, dst
->expires
))
429 dst
->expires
= expires
;
432 /* Output packet to network from transport. */
433 static inline int dst_output(struct sk_buff
*skb
)
435 return skb_dst(skb
)->output(skb
);
438 /* Input packet from network to transport. */
439 static inline int dst_input(struct sk_buff
*skb
)
441 return skb_dst(skb
)->input(skb
);
444 static inline struct dst_entry
*dst_check(struct dst_entry
*dst
, u32 cookie
)
447 dst
= dst
->ops
->check(dst
, cookie
);
451 extern void dst_init(void);
453 /* Flags for xfrm_lookup flags argument. */
455 XFRM_LOOKUP_ICMP
= 1 << 0,
460 static inline struct dst_entry
*xfrm_lookup(struct net
*net
,
461 struct dst_entry
*dst_orig
,
462 const struct flowi
*fl
, struct sock
*sk
,
468 extern struct dst_entry
*xfrm_lookup(struct net
*net
, struct dst_entry
*dst_orig
,
469 const struct flowi
*fl
, struct sock
*sk
,
473 #endif /* _NET_DST_H */