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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
65 unsigned short header_len
; /* more space at head required */
66 unsigned short trailer_len
; /* space to reserve at tail */
67 #ifdef CONFIG_IP_ROUTE_CLASSID
74 * Align __refcnt to a 64 bytes alignment
75 * (L1_CACHE_SIZE would be too much)
78 long __pad_to_align_refcnt
[2];
81 * __refcnt wants to be on a different cache line from
82 * input/output/ops or performance tanks badly
84 atomic_t __refcnt
; /* client references */
86 unsigned long lastuse
;
88 struct dst_entry
*next
;
89 struct rtable __rcu
*rt_next
;
90 struct rt6_info
*rt6_next
;
91 struct dn_route __rcu
*dn_next
;
95 static inline struct neighbour
*dst_get_neighbour_noref(struct dst_entry
*dst
)
97 return rcu_dereference(dst
->_neighbour
);
100 static inline struct neighbour
*dst_get_neighbour_noref_raw(struct dst_entry
*dst
)
102 return rcu_dereference_raw(dst
->_neighbour
);
105 static inline void dst_set_neighbour(struct dst_entry
*dst
, struct neighbour
*neigh
)
107 rcu_assign_pointer(dst
->_neighbour
, neigh
);
110 extern u32
*dst_cow_metrics_generic(struct dst_entry
*dst
, unsigned long old
);
111 extern const u32 dst_default_metrics
[RTAX_MAX
];
113 #define DST_METRICS_READ_ONLY 0x1UL
114 #define __DST_METRICS_PTR(Y) \
115 ((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
116 #define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
118 static inline bool dst_metrics_read_only(const struct dst_entry
*dst
)
120 return dst
->_metrics
& DST_METRICS_READ_ONLY
;
123 extern void __dst_destroy_metrics_generic(struct dst_entry
*dst
, unsigned long old
);
125 static inline void dst_destroy_metrics_generic(struct dst_entry
*dst
)
127 unsigned long val
= dst
->_metrics
;
128 if (!(val
& DST_METRICS_READ_ONLY
))
129 __dst_destroy_metrics_generic(dst
, val
);
132 static inline u32
*dst_metrics_write_ptr(struct dst_entry
*dst
)
134 unsigned long p
= dst
->_metrics
;
138 if (p
& DST_METRICS_READ_ONLY
)
139 return dst
->ops
->cow_metrics(dst
, p
);
140 return __DST_METRICS_PTR(p
);
143 /* This may only be invoked before the entry has reached global
146 static inline void dst_init_metrics(struct dst_entry
*dst
,
147 const u32
*src_metrics
,
150 dst
->_metrics
= ((unsigned long) src_metrics
) |
151 (read_only
? DST_METRICS_READ_ONLY
: 0);
154 static inline void dst_copy_metrics(struct dst_entry
*dest
, const struct dst_entry
*src
)
156 u32
*dst_metrics
= dst_metrics_write_ptr(dest
);
159 u32
*src_metrics
= DST_METRICS_PTR(src
);
161 memcpy(dst_metrics
, src_metrics
, RTAX_MAX
* sizeof(u32
));
165 static inline u32
*dst_metrics_ptr(struct dst_entry
*dst
)
167 return DST_METRICS_PTR(dst
);
171 dst_metric_raw(const struct dst_entry
*dst
, const int metric
)
173 u32
*p
= DST_METRICS_PTR(dst
);
179 dst_metric(const struct dst_entry
*dst
, const int metric
)
181 WARN_ON_ONCE(metric
== RTAX_HOPLIMIT
||
182 metric
== RTAX_ADVMSS
||
184 return dst_metric_raw(dst
, metric
);
188 dst_metric_advmss(const struct dst_entry
*dst
)
190 u32 advmss
= dst_metric_raw(dst
, RTAX_ADVMSS
);
193 advmss
= dst
->ops
->default_advmss(dst
);
198 static inline void dst_metric_set(struct dst_entry
*dst
, int metric
, u32 val
)
200 u32
*p
= dst_metrics_write_ptr(dst
);
207 dst_feature(const struct dst_entry
*dst
, u32 feature
)
209 return dst_metric(dst
, RTAX_FEATURES
) & feature
;
212 static inline u32
dst_mtu(const struct dst_entry
*dst
)
214 return dst
->ops
->mtu(dst
);
217 /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
218 static inline unsigned long dst_metric_rtt(const struct dst_entry
*dst
, int metric
)
220 return msecs_to_jiffies(dst_metric(dst
, metric
));
223 static inline void set_dst_metric_rtt(struct dst_entry
*dst
, int metric
,
226 dst_metric_set(dst
, metric
, jiffies_to_msecs(rtt
));
230 dst_allfrag(const struct dst_entry
*dst
)
232 int ret
= dst_feature(dst
, RTAX_FEATURE_ALLFRAG
);
237 dst_metric_locked(const struct dst_entry
*dst
, int metric
)
239 return dst_metric(dst
, RTAX_LOCK
) & (1<<metric
);
242 static inline void dst_hold(struct dst_entry
* dst
)
245 * If your kernel compilation stops here, please check
246 * __pad_to_align_refcnt declaration in struct dst_entry
248 BUILD_BUG_ON(offsetof(struct dst_entry
, __refcnt
) & 63);
249 atomic_inc(&dst
->__refcnt
);
252 static inline void dst_use(struct dst_entry
*dst
, unsigned long time
)
259 static inline void dst_use_noref(struct dst_entry
*dst
, unsigned long time
)
266 struct dst_entry
* dst_clone(struct dst_entry
* dst
)
269 atomic_inc(&dst
->__refcnt
);
273 extern void dst_release(struct dst_entry
*dst
);
275 static inline void refdst_drop(unsigned long refdst
)
277 if (!(refdst
& SKB_DST_NOREF
))
278 dst_release((struct dst_entry
*)(refdst
& SKB_DST_PTRMASK
));
282 * skb_dst_drop - drops skb dst
285 * Drops dst reference count if a reference was taken.
287 static inline void skb_dst_drop(struct sk_buff
*skb
)
289 if (skb
->_skb_refdst
) {
290 refdst_drop(skb
->_skb_refdst
);
291 skb
->_skb_refdst
= 0UL;
295 static inline void skb_dst_copy(struct sk_buff
*nskb
, const struct sk_buff
*oskb
)
297 nskb
->_skb_refdst
= oskb
->_skb_refdst
;
298 if (!(nskb
->_skb_refdst
& SKB_DST_NOREF
))
299 dst_clone(skb_dst(nskb
));
303 * skb_dst_force - makes sure skb dst is refcounted
306 * If dst is not yet refcounted, let's do it
308 static inline void skb_dst_force(struct sk_buff
*skb
)
310 if (skb_dst_is_noref(skb
)) {
311 WARN_ON(!rcu_read_lock_held());
312 skb
->_skb_refdst
&= ~SKB_DST_NOREF
;
313 dst_clone(skb_dst(skb
));
319 * __skb_tunnel_rx - prepare skb for rx reinsert
321 * @dev: tunnel device
323 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
324 * so make some cleanups. (no accounting done)
326 static inline void __skb_tunnel_rx(struct sk_buff
*skb
, struct net_device
*dev
)
331 * Clear rxhash so that we can recalulate the hash for the
332 * encapsulated packet, unless we have already determine the hash
333 * over the L4 4-tuple.
337 skb_set_queue_mapping(skb
, 0);
343 * skb_tunnel_rx - prepare skb for rx reinsert
345 * @dev: tunnel device
347 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
348 * so make some cleanups, and perform accounting.
349 * Note: this accounting is not SMP safe.
351 static inline void skb_tunnel_rx(struct sk_buff
*skb
, struct net_device
*dev
)
353 /* TODO : stats should be SMP safe */
354 dev
->stats
.rx_packets
++;
355 dev
->stats
.rx_bytes
+= skb
->len
;
356 __skb_tunnel_rx(skb
, dev
);
359 /* Children define the path of the packet through the
360 * Linux networking. Thus, destinations are stackable.
363 static inline struct dst_entry
*skb_dst_pop(struct sk_buff
*skb
)
365 struct dst_entry
*child
= dst_clone(skb_dst(skb
)->child
);
371 extern int dst_discard(struct sk_buff
*skb
);
372 extern void *dst_alloc(struct dst_ops
* ops
, struct net_device
*dev
,
373 int initial_ref
, int initial_obsolete
, int flags
);
374 extern void __dst_free(struct dst_entry
* dst
);
375 extern struct dst_entry
*dst_destroy(struct dst_entry
* dst
);
377 static inline void dst_free(struct dst_entry
* dst
)
379 if (dst
->obsolete
> 1)
381 if (!atomic_read(&dst
->__refcnt
)) {
382 dst
= dst_destroy(dst
);
389 static inline void dst_rcu_free(struct rcu_head
*head
)
391 struct dst_entry
*dst
= container_of(head
, struct dst_entry
, rcu_head
);
395 static inline void dst_confirm(struct dst_entry
*dst
)
401 n
= dst_get_neighbour_noref(dst
);
407 static inline struct neighbour
*dst_neigh_lookup(const struct dst_entry
*dst
, const void *daddr
)
409 return dst
->ops
->neigh_lookup(dst
, daddr
);
412 static inline void dst_link_failure(struct sk_buff
*skb
)
414 struct dst_entry
*dst
= skb_dst(skb
);
415 if (dst
&& dst
->ops
&& dst
->ops
->link_failure
)
416 dst
->ops
->link_failure(skb
);
419 static inline void dst_set_expires(struct dst_entry
*dst
, int timeout
)
421 unsigned long expires
= jiffies
+ timeout
;
426 if (dst
->expires
== 0 || time_before(expires
, dst
->expires
))
427 dst
->expires
= expires
;
430 /* Output packet to network from transport. */
431 static inline int dst_output(struct sk_buff
*skb
)
433 return skb_dst(skb
)->output(skb
);
436 /* Input packet from network to transport. */
437 static inline int dst_input(struct sk_buff
*skb
)
439 return skb_dst(skb
)->input(skb
);
442 static inline struct dst_entry
*dst_check(struct dst_entry
*dst
, u32 cookie
)
445 dst
= dst
->ops
->check(dst
, cookie
);
449 extern void dst_init(void);
451 /* Flags for xfrm_lookup flags argument. */
453 XFRM_LOOKUP_ICMP
= 1 << 0,
458 static inline struct dst_entry
*xfrm_lookup(struct net
*net
,
459 struct dst_entry
*dst_orig
,
460 const struct flowi
*fl
, struct sock
*sk
,
466 extern struct dst_entry
*xfrm_lookup(struct net
*net
, struct dst_entry
*dst_orig
,
467 const struct flowi
*fl
, struct sock
*sk
,
471 #endif /* _NET_DST_H */