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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; | |
62fa8a84 DM |
43 | struct dst_ops *ops; |
44 | unsigned long _metrics; | |
1da177e4 | 45 | unsigned long expires; |
f1dd9c37 | 46 | struct dst_entry *path; |
1da177e4 LT |
47 | struct neighbour *neighbour; |
48 | struct hh_cache *hh; | |
def8b4fa | 49 | #ifdef CONFIG_XFRM |
1da177e4 | 50 | struct xfrm_state *xfrm; |
5635c10d ED |
51 | #else |
52 | void *__pad1; | |
def8b4fa | 53 | #endif |
1da177e4 LT |
54 | int (*input)(struct sk_buff*); |
55 | int (*output)(struct sk_buff*); | |
56 | ||
62fa8a84 DM |
57 | short error; |
58 | short obsolete; | |
59 | unsigned short header_len; /* more space at head required */ | |
60 | unsigned short trailer_len; /* space to reserve at tail */ | |
c7066f70 | 61 | #ifdef CONFIG_IP_ROUTE_CLASSID |
f1dd9c37 | 62 | __u32 tclassid; |
5635c10d ED |
63 | #else |
64 | __u32 __pad2; | |
f1dd9c37 ZY |
65 | #endif |
66 | ||
5635c10d ED |
67 | /* |
68 | * Align __refcnt to a 64 bytes alignment | |
69 | * (L1_CACHE_SIZE would be too much) | |
70 | */ | |
71 | #ifdef CONFIG_64BIT | |
5635c10d ED |
72 | long __pad_to_align_refcnt[1]; |
73 | #endif | |
f1dd9c37 ZY |
74 | /* |
75 | * __refcnt wants to be on a different cache line from | |
76 | * input/output/ops or performance tanks badly | |
77 | */ | |
1e19e02c ED |
78 | atomic_t __refcnt; /* client references */ |
79 | int __use; | |
f1dd9c37 | 80 | unsigned long lastuse; |
62fa8a84 DM |
81 | int flags; |
82 | #define DST_HOST 0x0001 | |
83 | #define DST_NOXFRM 0x0002 | |
84 | #define DST_NOPOLICY 0x0004 | |
85 | #define DST_NOHASH 0x0008 | |
86 | #define DST_NOCACHE 0x0010 | |
1e19e02c | 87 | union { |
fc766e4c ED |
88 | struct dst_entry *next; |
89 | struct rtable __rcu *rt_next; | |
90 | struct rt6_info *rt6_next; | |
91 | struct dn_route __rcu *dn_next; | |
1e19e02c | 92 | }; |
1da177e4 LT |
93 | }; |
94 | ||
1da177e4 LT |
95 | #ifdef __KERNEL__ |
96 | ||
62fa8a84 | 97 | extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old); |
725d1e1b | 98 | extern const u32 dst_default_metrics[RTAX_MAX]; |
62fa8a84 DM |
99 | |
100 | #define DST_METRICS_READ_ONLY 0x1UL | |
101 | #define __DST_METRICS_PTR(Y) \ | |
102 | ((u32 *)((Y) & ~DST_METRICS_READ_ONLY)) | |
103 | #define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics) | |
104 | ||
105 | static inline bool dst_metrics_read_only(const struct dst_entry *dst) | |
106 | { | |
107 | return dst->_metrics & DST_METRICS_READ_ONLY; | |
108 | } | |
109 | ||
110 | extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old); | |
111 | ||
112 | static inline void dst_destroy_metrics_generic(struct dst_entry *dst) | |
113 | { | |
114 | unsigned long val = dst->_metrics; | |
115 | if (!(val & DST_METRICS_READ_ONLY)) | |
116 | __dst_destroy_metrics_generic(dst, val); | |
117 | } | |
118 | ||
119 | static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst) | |
120 | { | |
121 | unsigned long p = dst->_metrics; | |
122 | ||
123 | if (p & DST_METRICS_READ_ONLY) | |
124 | return dst->ops->cow_metrics(dst, p); | |
125 | return __DST_METRICS_PTR(p); | |
126 | } | |
127 | ||
128 | /* This may only be invoked before the entry has reached global | |
129 | * visibility. | |
130 | */ | |
131 | static inline void dst_init_metrics(struct dst_entry *dst, | |
132 | const u32 *src_metrics, | |
133 | bool read_only) | |
134 | { | |
135 | dst->_metrics = ((unsigned long) src_metrics) | | |
136 | (read_only ? DST_METRICS_READ_ONLY : 0); | |
137 | } | |
138 | ||
139 | static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src) | |
140 | { | |
141 | u32 *dst_metrics = dst_metrics_write_ptr(dest); | |
142 | ||
143 | if (dst_metrics) { | |
144 | u32 *src_metrics = DST_METRICS_PTR(src); | |
145 | ||
146 | memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32)); | |
147 | } | |
148 | } | |
149 | ||
150 | static inline u32 *dst_metrics_ptr(struct dst_entry *dst) | |
151 | { | |
152 | return DST_METRICS_PTR(dst); | |
153 | } | |
154 | ||
1da177e4 | 155 | static inline u32 |
5170ae82 | 156 | dst_metric_raw(const struct dst_entry *dst, const int metric) |
1da177e4 | 157 | { |
62fa8a84 DM |
158 | u32 *p = DST_METRICS_PTR(dst); |
159 | ||
160 | return p[metric-1]; | |
defb3519 DM |
161 | } |
162 | ||
5170ae82 DM |
163 | static inline u32 |
164 | dst_metric(const struct dst_entry *dst, const int metric) | |
165 | { | |
0dbaee3b | 166 | WARN_ON_ONCE(metric == RTAX_HOPLIMIT || |
d33e4553 DM |
167 | metric == RTAX_ADVMSS || |
168 | metric == RTAX_MTU); | |
5170ae82 DM |
169 | return dst_metric_raw(dst, metric); |
170 | } | |
171 | ||
0dbaee3b DM |
172 | static inline u32 |
173 | dst_metric_advmss(const struct dst_entry *dst) | |
174 | { | |
175 | u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS); | |
176 | ||
177 | if (!advmss) | |
178 | advmss = dst->ops->default_advmss(dst); | |
179 | ||
180 | return advmss; | |
181 | } | |
182 | ||
defb3519 DM |
183 | static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) |
184 | { | |
62fa8a84 | 185 | u32 *p = dst_metrics_write_ptr(dst); |
defb3519 | 186 | |
62fa8a84 DM |
187 | if (p) |
188 | p[metric-1] = val; | |
1da177e4 LT |
189 | } |
190 | ||
0c3adfb8 GBY |
191 | static inline u32 |
192 | dst_feature(const struct dst_entry *dst, u32 feature) | |
193 | { | |
bb5b7c11 | 194 | return dst_metric(dst, RTAX_FEATURES) & feature; |
0c3adfb8 GBY |
195 | } |
196 | ||
1da177e4 LT |
197 | static inline u32 dst_mtu(const struct dst_entry *dst) |
198 | { | |
d33e4553 DM |
199 | u32 mtu = dst_metric_raw(dst, RTAX_MTU); |
200 | ||
201 | if (!mtu) | |
202 | mtu = dst->ops->default_mtu(dst); | |
203 | ||
1da177e4 LT |
204 | return mtu; |
205 | } | |
206 | ||
c1e20f7c SH |
207 | /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */ |
208 | static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric) | |
209 | { | |
210 | return msecs_to_jiffies(dst_metric(dst, metric)); | |
211 | } | |
212 | ||
213 | static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric, | |
214 | unsigned long rtt) | |
215 | { | |
defb3519 | 216 | dst_metric_set(dst, metric, jiffies_to_msecs(rtt)); |
c1e20f7c SH |
217 | } |
218 | ||
1da177e4 LT |
219 | static inline u32 |
220 | dst_allfrag(const struct dst_entry *dst) | |
221 | { | |
0c3adfb8 | 222 | int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG); |
1da177e4 LT |
223 | return ret; |
224 | } | |
225 | ||
226 | static inline int | |
d33e4553 | 227 | dst_metric_locked(const struct dst_entry *dst, int metric) |
1da177e4 LT |
228 | { |
229 | return dst_metric(dst, RTAX_LOCK) & (1<<metric); | |
230 | } | |
231 | ||
232 | static inline void dst_hold(struct dst_entry * dst) | |
233 | { | |
5635c10d ED |
234 | /* |
235 | * If your kernel compilation stops here, please check | |
236 | * __pad_to_align_refcnt declaration in struct dst_entry | |
237 | */ | |
238 | BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); | |
1da177e4 LT |
239 | atomic_inc(&dst->__refcnt); |
240 | } | |
241 | ||
03f49f34 PE |
242 | static inline void dst_use(struct dst_entry *dst, unsigned long time) |
243 | { | |
244 | dst_hold(dst); | |
245 | dst->__use++; | |
246 | dst->lastuse = time; | |
247 | } | |
248 | ||
7fee226a ED |
249 | static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) |
250 | { | |
251 | dst->__use++; | |
252 | dst->lastuse = time; | |
253 | } | |
254 | ||
1da177e4 LT |
255 | static inline |
256 | struct dst_entry * dst_clone(struct dst_entry * dst) | |
257 | { | |
258 | if (dst) | |
259 | atomic_inc(&dst->__refcnt); | |
260 | return dst; | |
261 | } | |
262 | ||
8d330868 | 263 | extern void dst_release(struct dst_entry *dst); |
7fee226a ED |
264 | |
265 | static inline void refdst_drop(unsigned long refdst) | |
266 | { | |
267 | if (!(refdst & SKB_DST_NOREF)) | |
268 | dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK)); | |
269 | } | |
270 | ||
271 | /** | |
272 | * skb_dst_drop - drops skb dst | |
273 | * @skb: buffer | |
274 | * | |
275 | * Drops dst reference count if a reference was taken. | |
276 | */ | |
adf30907 ED |
277 | static inline void skb_dst_drop(struct sk_buff *skb) |
278 | { | |
7fee226a ED |
279 | if (skb->_skb_refdst) { |
280 | refdst_drop(skb->_skb_refdst); | |
281 | skb->_skb_refdst = 0UL; | |
282 | } | |
283 | } | |
284 | ||
285 | static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb) | |
286 | { | |
287 | nskb->_skb_refdst = oskb->_skb_refdst; | |
288 | if (!(nskb->_skb_refdst & SKB_DST_NOREF)) | |
289 | dst_clone(skb_dst(nskb)); | |
290 | } | |
291 | ||
292 | /** | |
293 | * skb_dst_force - makes sure skb dst is refcounted | |
294 | * @skb: buffer | |
295 | * | |
296 | * If dst is not yet refcounted, let's do it | |
297 | */ | |
298 | static inline void skb_dst_force(struct sk_buff *skb) | |
299 | { | |
300 | if (skb_dst_is_noref(skb)) { | |
301 | WARN_ON(!rcu_read_lock_held()); | |
302 | skb->_skb_refdst &= ~SKB_DST_NOREF; | |
303 | dst_clone(skb_dst(skb)); | |
304 | } | |
adf30907 | 305 | } |
1da177e4 | 306 | |
d19d56dd | 307 | |
290b895e ED |
308 | /** |
309 | * __skb_tunnel_rx - prepare skb for rx reinsert | |
310 | * @skb: buffer | |
311 | * @dev: tunnel device | |
312 | * | |
313 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
314 | * so make some cleanups. (no accounting done) | |
315 | */ | |
316 | static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
317 | { | |
318 | skb->dev = dev; | |
319 | skb->rxhash = 0; | |
320 | skb_set_queue_mapping(skb, 0); | |
321 | skb_dst_drop(skb); | |
322 | nf_reset(skb); | |
323 | } | |
324 | ||
d19d56dd ED |
325 | /** |
326 | * skb_tunnel_rx - prepare skb for rx reinsert | |
327 | * @skb: buffer | |
328 | * @dev: tunnel device | |
329 | * | |
330 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
331 | * so make some cleanups, and perform accounting. | |
290b895e | 332 | * Note: this accounting is not SMP safe. |
d19d56dd ED |
333 | */ |
334 | static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
335 | { | |
d19d56dd ED |
336 | /* TODO : stats should be SMP safe */ |
337 | dev->stats.rx_packets++; | |
338 | dev->stats.rx_bytes += skb->len; | |
290b895e | 339 | __skb_tunnel_rx(skb, dev); |
d19d56dd ED |
340 | } |
341 | ||
1da177e4 LT |
342 | /* Children define the path of the packet through the |
343 | * Linux networking. Thus, destinations are stackable. | |
344 | */ | |
345 | ||
8764ab2c | 346 | static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb) |
1da177e4 | 347 | { |
8764ab2c | 348 | struct dst_entry *child = skb_dst(skb)->child; |
1da177e4 | 349 | |
8764ab2c | 350 | skb_dst_drop(skb); |
1da177e4 LT |
351 | return child; |
352 | } | |
353 | ||
352e512c | 354 | extern int dst_discard(struct sk_buff *skb); |
3c7bd1a1 | 355 | extern void *dst_alloc(struct dst_ops * ops, int initial_ref); |
1da177e4 LT |
356 | extern void __dst_free(struct dst_entry * dst); |
357 | extern struct dst_entry *dst_destroy(struct dst_entry * dst); | |
358 | ||
359 | static inline void dst_free(struct dst_entry * dst) | |
360 | { | |
361 | if (dst->obsolete > 1) | |
362 | return; | |
363 | if (!atomic_read(&dst->__refcnt)) { | |
364 | dst = dst_destroy(dst); | |
365 | if (!dst) | |
366 | return; | |
367 | } | |
368 | __dst_free(dst); | |
369 | } | |
370 | ||
371 | static inline void dst_rcu_free(struct rcu_head *head) | |
372 | { | |
373 | struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); | |
374 | dst_free(dst); | |
375 | } | |
376 | ||
377 | static inline void dst_confirm(struct dst_entry *dst) | |
378 | { | |
379 | if (dst) | |
380 | neigh_confirm(dst->neighbour); | |
381 | } | |
382 | ||
1da177e4 LT |
383 | static inline void dst_link_failure(struct sk_buff *skb) |
384 | { | |
adf30907 | 385 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
386 | if (dst && dst->ops && dst->ops->link_failure) |
387 | dst->ops->link_failure(skb); | |
388 | } | |
389 | ||
390 | static inline void dst_set_expires(struct dst_entry *dst, int timeout) | |
391 | { | |
392 | unsigned long expires = jiffies + timeout; | |
393 | ||
394 | if (expires == 0) | |
395 | expires = 1; | |
396 | ||
397 | if (dst->expires == 0 || time_before(expires, dst->expires)) | |
398 | dst->expires = expires; | |
399 | } | |
400 | ||
401 | /* Output packet to network from transport. */ | |
402 | static inline int dst_output(struct sk_buff *skb) | |
403 | { | |
adf30907 | 404 | return skb_dst(skb)->output(skb); |
1da177e4 LT |
405 | } |
406 | ||
407 | /* Input packet from network to transport. */ | |
408 | static inline int dst_input(struct sk_buff *skb) | |
409 | { | |
adf30907 | 410 | return skb_dst(skb)->input(skb); |
1da177e4 LT |
411 | } |
412 | ||
413 | static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie) | |
414 | { | |
415 | if (dst->obsolete) | |
416 | dst = dst->ops->check(dst, cookie); | |
417 | return dst; | |
418 | } | |
419 | ||
420 | extern void dst_init(void); | |
421 | ||
815f4e57 HX |
422 | /* Flags for xfrm_lookup flags argument. */ |
423 | enum { | |
424 | XFRM_LOOKUP_WAIT = 1 << 0, | |
8b7817f3 | 425 | XFRM_LOOKUP_ICMP = 1 << 1, |
815f4e57 HX |
426 | }; |
427 | ||
1da177e4 LT |
428 | struct flowi; |
429 | #ifndef CONFIG_XFRM | |
52479b62 | 430 | static inline int xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
dee9f4bc DM |
431 | const struct flowi *fl, struct sock *sk, |
432 | int flags) | |
1da177e4 LT |
433 | { |
434 | return 0; | |
435 | } | |
52479b62 | 436 | static inline int __xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
dee9f4bc DM |
437 | const struct flowi *fl, struct sock *sk, |
438 | int flags) | |
14e50e57 DM |
439 | { |
440 | return 0; | |
441 | } | |
1da177e4 | 442 | #else |
52479b62 | 443 | extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
dee9f4bc | 444 | const struct flowi *fl, struct sock *sk, int flags); |
52479b62 | 445 | extern int __xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
dee9f4bc | 446 | const struct flowi *fl, struct sock *sk, int flags); |
1da177e4 LT |
447 | #endif |
448 | #endif | |
449 | ||
450 | #endif /* _NET_DST_H */ |