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Commit | Line | Data |
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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 | ||
37 | struct sk_buff; | |
38 | ||
fd2c3ef7 | 39 | struct 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 | ||
106 | static inline u32 | |
107 | dst_metric(const struct dst_entry *dst, int metric) | |
108 | { | |
defb3519 DM |
109 | return dst->_metrics[metric-1]; |
110 | } | |
111 | ||
112 | static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) | |
113 | { | |
114 | dst->_metrics[metric-1] = val; | |
115 | } | |
116 | ||
117 | static 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 | ||
122 | static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src) | |
123 | { | |
124 | dst_import_metrics(dest, src->_metrics); | |
125 | } | |
126 | ||
127 | static inline u32 *dst_metrics_ptr(struct dst_entry *dst) | |
128 | { | |
129 | return dst->_metrics; | |
1da177e4 LT |
130 | } |
131 | ||
0c3adfb8 GBY |
132 | static inline u32 |
133 | dst_feature(const struct dst_entry *dst, u32 feature) | |
134 | { | |
bb5b7c11 | 135 | return dst_metric(dst, RTAX_FEATURES) & feature; |
0c3adfb8 GBY |
136 | } |
137 | ||
1da177e4 LT |
138 | static 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 */ |
149 | static 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 | ||
154 | static 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 |
160 | static inline u32 |
161 | dst_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 | ||
169 | static inline int | |
170 | dst_metric_locked(struct dst_entry *dst, int metric) | |
171 | { | |
172 | return dst_metric(dst, RTAX_LOCK) & (1<<metric); | |
173 | } | |
174 | ||
175 | static 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 |
185 | static 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 |
192 | static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) |
193 | { | |
194 | dst->__use++; | |
195 | dst->lastuse = time; | |
196 | } | |
197 | ||
1da177e4 LT |
198 | static inline |
199 | struct dst_entry * dst_clone(struct dst_entry * dst) | |
200 | { | |
201 | if (dst) | |
202 | atomic_inc(&dst->__refcnt); | |
203 | return dst; | |
204 | } | |
205 | ||
8d330868 | 206 | extern void dst_release(struct dst_entry *dst); |
7fee226a ED |
207 | |
208 | static 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 |
220 | static 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 | ||
228 | static 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 | */ | |
241 | static 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 | */ | |
259 | static 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 | */ |
277 | static 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 | 289 | static 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 | 297 | extern int dst_discard(struct sk_buff *skb); |
1da177e4 LT |
298 | extern void * dst_alloc(struct dst_ops * ops); |
299 | extern void __dst_free(struct dst_entry * dst); | |
300 | extern struct dst_entry *dst_destroy(struct dst_entry * dst); | |
301 | ||
302 | static 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 | ||
314 | static 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 | ||
320 | static inline void dst_confirm(struct dst_entry *dst) | |
321 | { | |
322 | if (dst) | |
323 | neigh_confirm(dst->neighbour); | |
324 | } | |
325 | ||
1da177e4 LT |
326 | static 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 | ||
333 | static 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. */ | |
345 | static 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. */ | |
351 | static inline int dst_input(struct sk_buff *skb) | |
352 | { | |
adf30907 | 353 | return skb_dst(skb)->input(skb); |
1da177e4 LT |
354 | } |
355 | ||
356 | static 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 | ||
363 | extern void dst_init(void); | |
364 | ||
815f4e57 HX |
365 | /* Flags for xfrm_lookup flags argument. */ |
366 | enum { | |
367 | XFRM_LOOKUP_WAIT = 1 << 0, | |
8b7817f3 | 368 | XFRM_LOOKUP_ICMP = 1 << 1, |
815f4e57 HX |
369 | }; |
370 | ||
1da177e4 LT |
371 | struct flowi; |
372 | #ifndef CONFIG_XFRM | |
52479b62 AD |
373 | static 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 |
378 | static 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 |
384 | extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
385 | struct flowi *fl, struct sock *sk, int flags); | |
386 | extern 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 */ |