net: Abstract away all dst_entry metrics accesses.
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / net / dst.h
CommitLineData
1da177e4
LT
1/*
2 * net/dst.h Protocol independent destination cache definitions.
3 *
4 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
5 *
6 */
7
8#ifndef _NET_DST_H
9#define _NET_DST_H
10
86393e52 11#include <net/dst_ops.h>
14c85021 12#include <linux/netdevice.h>
1da177e4
LT
13#include <linux/rtnetlink.h>
14#include <linux/rcupdate.h>
15#include <linux/jiffies.h>
16#include <net/neighbour.h>
17#include <asm/processor.h>
18
19/*
20 * 0 - no debugging messages
21 * 1 - rare events and bugs (default)
22 * 2 - trace mode.
23 */
24#define RT_CACHE_DEBUG 0
25
26#define DST_GC_MIN (HZ/10)
27#define DST_GC_INC (HZ/2)
28#define DST_GC_MAX (120*HZ)
29
30/* Each dst_entry has reference count and sits in some parent list(s).
31 * When it is removed from parent list, it is "freed" (dst_free).
32 * After this it enters dead state (dst->obsolete > 0) and if its refcnt
33 * is zero, it can be destroyed immediately, otherwise it is added
34 * to gc list and garbage collector periodically checks the refcnt.
35 */
36
37struct sk_buff;
38
fd2c3ef7 39struct dst_entry {
1e19e02c 40 struct rcu_head rcu_head;
1da177e4
LT
41 struct dst_entry *child;
42 struct net_device *dev;
c4d54110
HX
43 short error;
44 short obsolete;
1da177e4 45 int flags;
c7d4426a
ED
46#define DST_HOST 0x0001
47#define DST_NOXFRM 0x0002
48#define DST_NOPOLICY 0x0004
49#define DST_NOHASH 0x0008
50#define DST_NOCACHE 0x0010
1da177e4
LT
51 unsigned long expires;
52
53 unsigned short header_len; /* more space at head required */
54 unsigned short trailer_len; /* space to reserve at tail */
55
69a73829 56 unsigned int rate_tokens;
f1dd9c37 57 unsigned long rate_last; /* rate limiting for ICMP */
69a73829 58
f1dd9c37 59 struct dst_entry *path;
1da177e4 60
1da177e4
LT
61 struct neighbour *neighbour;
62 struct hh_cache *hh;
def8b4fa 63#ifdef CONFIG_XFRM
1da177e4 64 struct xfrm_state *xfrm;
5635c10d
ED
65#else
66 void *__pad1;
def8b4fa 67#endif
1da177e4
LT
68 int (*input)(struct sk_buff*);
69 int (*output)(struct sk_buff*);
70
1da177e4 71 struct dst_ops *ops;
f1dd9c37 72
defb3519 73 u32 _metrics[RTAX_MAX];
f1dd9c37
ZY
74
75#ifdef CONFIG_NET_CLS_ROUTE
76 __u32 tclassid;
5635c10d
ED
77#else
78 __u32 __pad2;
f1dd9c37
ZY
79#endif
80
5635c10d
ED
81
82 /*
83 * Align __refcnt to a 64 bytes alignment
84 * (L1_CACHE_SIZE would be too much)
85 */
86#ifdef CONFIG_64BIT
5635c10d
ED
87 long __pad_to_align_refcnt[1];
88#endif
f1dd9c37
ZY
89 /*
90 * __refcnt wants to be on a different cache line from
91 * input/output/ops or performance tanks badly
92 */
1e19e02c
ED
93 atomic_t __refcnt; /* client references */
94 int __use;
f1dd9c37 95 unsigned long lastuse;
1e19e02c 96 union {
fc766e4c
ED
97 struct dst_entry *next;
98 struct rtable __rcu *rt_next;
99 struct rt6_info *rt6_next;
100 struct dn_route __rcu *dn_next;
1e19e02c 101 };
1da177e4
LT
102};
103
1da177e4
LT
104#ifdef __KERNEL__
105
106static inline u32
107dst_metric(const struct dst_entry *dst, int metric)
108{
defb3519
DM
109 return dst->_metrics[metric-1];
110}
111
112static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
113{
114 dst->_metrics[metric-1] = val;
115}
116
117static inline void dst_import_metrics(struct dst_entry *dst, const u32 *src_metrics)
118{
119 memcpy(dst->_metrics, src_metrics, RTAX_MAX * sizeof(u32));
120}
121
122static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
123{
124 dst_import_metrics(dest, src->_metrics);
125}
126
127static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
128{
129 return dst->_metrics;
1da177e4
LT
130}
131
0c3adfb8
GBY
132static inline u32
133dst_feature(const struct dst_entry *dst, u32 feature)
134{
bb5b7c11 135 return dst_metric(dst, RTAX_FEATURES) & feature;
0c3adfb8
GBY
136}
137
1da177e4
LT
138static inline u32 dst_mtu(const struct dst_entry *dst)
139{
140 u32 mtu = dst_metric(dst, RTAX_MTU);
141 /*
142 * Alexey put it here, so ask him about it :)
143 */
144 barrier();
145 return mtu;
146}
147
c1e20f7c
SH
148/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
149static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
150{
151 return msecs_to_jiffies(dst_metric(dst, metric));
152}
153
154static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
155 unsigned long rtt)
156{
defb3519 157 dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
c1e20f7c
SH
158}
159
1da177e4
LT
160static inline u32
161dst_allfrag(const struct dst_entry *dst)
162{
0c3adfb8 163 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
1da177e4
LT
164 /* Yes, _exactly_. This is paranoia. */
165 barrier();
166 return ret;
167}
168
169static inline int
170dst_metric_locked(struct dst_entry *dst, int metric)
171{
172 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
173}
174
175static inline void dst_hold(struct dst_entry * dst)
176{
5635c10d
ED
177 /*
178 * If your kernel compilation stops here, please check
179 * __pad_to_align_refcnt declaration in struct dst_entry
180 */
181 BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
1da177e4
LT
182 atomic_inc(&dst->__refcnt);
183}
184
03f49f34
PE
185static inline void dst_use(struct dst_entry *dst, unsigned long time)
186{
187 dst_hold(dst);
188 dst->__use++;
189 dst->lastuse = time;
190}
191
7fee226a
ED
192static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
193{
194 dst->__use++;
195 dst->lastuse = time;
196}
197
1da177e4
LT
198static inline
199struct dst_entry * dst_clone(struct dst_entry * dst)
200{
201 if (dst)
202 atomic_inc(&dst->__refcnt);
203 return dst;
204}
205
8d330868 206extern void dst_release(struct dst_entry *dst);
7fee226a
ED
207
208static inline void refdst_drop(unsigned long refdst)
209{
210 if (!(refdst & SKB_DST_NOREF))
211 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
212}
213
214/**
215 * skb_dst_drop - drops skb dst
216 * @skb: buffer
217 *
218 * Drops dst reference count if a reference was taken.
219 */
adf30907
ED
220static inline void skb_dst_drop(struct sk_buff *skb)
221{
7fee226a
ED
222 if (skb->_skb_refdst) {
223 refdst_drop(skb->_skb_refdst);
224 skb->_skb_refdst = 0UL;
225 }
226}
227
228static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
229{
230 nskb->_skb_refdst = oskb->_skb_refdst;
231 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
232 dst_clone(skb_dst(nskb));
233}
234
235/**
236 * skb_dst_force - makes sure skb dst is refcounted
237 * @skb: buffer
238 *
239 * If dst is not yet refcounted, let's do it
240 */
241static inline void skb_dst_force(struct sk_buff *skb)
242{
243 if (skb_dst_is_noref(skb)) {
244 WARN_ON(!rcu_read_lock_held());
245 skb->_skb_refdst &= ~SKB_DST_NOREF;
246 dst_clone(skb_dst(skb));
247 }
adf30907 248}
1da177e4 249
d19d56dd 250
290b895e
ED
251/**
252 * __skb_tunnel_rx - prepare skb for rx reinsert
253 * @skb: buffer
254 * @dev: tunnel device
255 *
256 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
257 * so make some cleanups. (no accounting done)
258 */
259static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
260{
261 skb->dev = dev;
262 skb->rxhash = 0;
263 skb_set_queue_mapping(skb, 0);
264 skb_dst_drop(skb);
265 nf_reset(skb);
266}
267
d19d56dd
ED
268/**
269 * skb_tunnel_rx - prepare skb for rx reinsert
270 * @skb: buffer
271 * @dev: tunnel device
272 *
273 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
274 * so make some cleanups, and perform accounting.
290b895e 275 * Note: this accounting is not SMP safe.
d19d56dd
ED
276 */
277static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
278{
d19d56dd
ED
279 /* TODO : stats should be SMP safe */
280 dev->stats.rx_packets++;
281 dev->stats.rx_bytes += skb->len;
290b895e 282 __skb_tunnel_rx(skb, dev);
d19d56dd
ED
283}
284
1da177e4
LT
285/* Children define the path of the packet through the
286 * Linux networking. Thus, destinations are stackable.
287 */
288
8764ab2c 289static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
1da177e4 290{
8764ab2c 291 struct dst_entry *child = skb_dst(skb)->child;
1da177e4 292
8764ab2c 293 skb_dst_drop(skb);
1da177e4
LT
294 return child;
295}
296
352e512c 297extern int dst_discard(struct sk_buff *skb);
1da177e4
LT
298extern void * dst_alloc(struct dst_ops * ops);
299extern void __dst_free(struct dst_entry * dst);
300extern struct dst_entry *dst_destroy(struct dst_entry * dst);
301
302static inline void dst_free(struct dst_entry * dst)
303{
304 if (dst->obsolete > 1)
305 return;
306 if (!atomic_read(&dst->__refcnt)) {
307 dst = dst_destroy(dst);
308 if (!dst)
309 return;
310 }
311 __dst_free(dst);
312}
313
314static inline void dst_rcu_free(struct rcu_head *head)
315{
316 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
317 dst_free(dst);
318}
319
320static inline void dst_confirm(struct dst_entry *dst)
321{
322 if (dst)
323 neigh_confirm(dst->neighbour);
324}
325
1da177e4
LT
326static inline void dst_link_failure(struct sk_buff *skb)
327{
adf30907 328 struct dst_entry *dst = skb_dst(skb);
1da177e4
LT
329 if (dst && dst->ops && dst->ops->link_failure)
330 dst->ops->link_failure(skb);
331}
332
333static inline void dst_set_expires(struct dst_entry *dst, int timeout)
334{
335 unsigned long expires = jiffies + timeout;
336
337 if (expires == 0)
338 expires = 1;
339
340 if (dst->expires == 0 || time_before(expires, dst->expires))
341 dst->expires = expires;
342}
343
344/* Output packet to network from transport. */
345static inline int dst_output(struct sk_buff *skb)
346{
adf30907 347 return skb_dst(skb)->output(skb);
1da177e4
LT
348}
349
350/* Input packet from network to transport. */
351static inline int dst_input(struct sk_buff *skb)
352{
adf30907 353 return skb_dst(skb)->input(skb);
1da177e4
LT
354}
355
356static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
357{
358 if (dst->obsolete)
359 dst = dst->ops->check(dst, cookie);
360 return dst;
361}
362
363extern void dst_init(void);
364
815f4e57
HX
365/* Flags for xfrm_lookup flags argument. */
366enum {
367 XFRM_LOOKUP_WAIT = 1 << 0,
8b7817f3 368 XFRM_LOOKUP_ICMP = 1 << 1,
815f4e57
HX
369};
370
1da177e4
LT
371struct flowi;
372#ifndef CONFIG_XFRM
52479b62
AD
373static inline int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
374 struct flowi *fl, struct sock *sk, int flags)
1da177e4
LT
375{
376 return 0;
377}
52479b62
AD
378static inline int __xfrm_lookup(struct net *net, struct dst_entry **dst_p,
379 struct flowi *fl, struct sock *sk, int flags)
14e50e57
DM
380{
381 return 0;
382}
1da177e4 383#else
52479b62
AD
384extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p,
385 struct flowi *fl, struct sock *sk, int flags);
386extern int __xfrm_lookup(struct net *net, struct dst_entry **dst_p,
387 struct flowi *fl, struct sock *sk, int flags);
1da177e4
LT
388#endif
389#endif
390
391#endif /* _NET_DST_H */