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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 | ||
1da177e4 LT |
19 | #define DST_GC_MIN (HZ/10) |
20 | #define DST_GC_INC (HZ/2) | |
21 | #define DST_GC_MAX (120*HZ) | |
22 | ||
23 | /* Each dst_entry has reference count and sits in some parent list(s). | |
24 | * When it is removed from parent list, it is "freed" (dst_free). | |
25 | * After this it enters dead state (dst->obsolete > 0) and if its refcnt | |
26 | * is zero, it can be destroyed immediately, otherwise it is added | |
27 | * to gc list and garbage collector periodically checks the refcnt. | |
28 | */ | |
29 | ||
30 | struct sk_buff; | |
31 | ||
fd2c3ef7 | 32 | struct dst_entry { |
1e19e02c | 33 | struct rcu_head rcu_head; |
1da177e4 LT |
34 | struct dst_entry *child; |
35 | struct net_device *dev; | |
62fa8a84 DM |
36 | struct dst_ops *ops; |
37 | unsigned long _metrics; | |
1da177e4 | 38 | unsigned long expires; |
f1dd9c37 | 39 | struct dst_entry *path; |
f2c31e32 | 40 | struct neighbour __rcu *_neighbour; |
def8b4fa | 41 | #ifdef CONFIG_XFRM |
1da177e4 | 42 | struct xfrm_state *xfrm; |
5635c10d ED |
43 | #else |
44 | void *__pad1; | |
def8b4fa | 45 | #endif |
1da177e4 LT |
46 | int (*input)(struct sk_buff*); |
47 | int (*output)(struct sk_buff*); | |
48 | ||
f6b72b62 DM |
49 | int flags; |
50 | #define DST_HOST 0x0001 | |
51 | #define DST_NOXFRM 0x0002 | |
52 | #define DST_NOPOLICY 0x0004 | |
53 | #define DST_NOHASH 0x0008 | |
54 | #define DST_NOCACHE 0x0010 | |
55 | #define DST_NOCOUNT 0x0020 | |
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 | |
f6b72b62 | 72 | long __pad_to_align_refcnt[2]; |
5635c10d | 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; |
1e19e02c | 81 | union { |
fc766e4c ED |
82 | struct dst_entry *next; |
83 | struct rtable __rcu *rt_next; | |
84 | struct rt6_info *rt6_next; | |
85 | struct dn_route __rcu *dn_next; | |
1e19e02c | 86 | }; |
1da177e4 LT |
87 | }; |
88 | ||
69cce1d1 DM |
89 | static inline struct neighbour *dst_get_neighbour(struct dst_entry *dst) |
90 | { | |
f2c31e32 ED |
91 | return rcu_dereference(dst->_neighbour); |
92 | } | |
93 | ||
94 | static inline struct neighbour *dst_get_neighbour_raw(struct dst_entry *dst) | |
95 | { | |
96 | return rcu_dereference_raw(dst->_neighbour); | |
69cce1d1 DM |
97 | } |
98 | ||
99 | static inline void dst_set_neighbour(struct dst_entry *dst, struct neighbour *neigh) | |
100 | { | |
f2c31e32 | 101 | rcu_assign_pointer(dst->_neighbour, neigh); |
69cce1d1 DM |
102 | } |
103 | ||
62fa8a84 | 104 | extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old); |
725d1e1b | 105 | extern const u32 dst_default_metrics[RTAX_MAX]; |
62fa8a84 DM |
106 | |
107 | #define DST_METRICS_READ_ONLY 0x1UL | |
108 | #define __DST_METRICS_PTR(Y) \ | |
109 | ((u32 *)((Y) & ~DST_METRICS_READ_ONLY)) | |
110 | #define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics) | |
111 | ||
112 | static inline bool dst_metrics_read_only(const struct dst_entry *dst) | |
113 | { | |
114 | return dst->_metrics & DST_METRICS_READ_ONLY; | |
115 | } | |
116 | ||
117 | extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old); | |
118 | ||
119 | static inline void dst_destroy_metrics_generic(struct dst_entry *dst) | |
120 | { | |
121 | unsigned long val = dst->_metrics; | |
122 | if (!(val & DST_METRICS_READ_ONLY)) | |
123 | __dst_destroy_metrics_generic(dst, val); | |
124 | } | |
125 | ||
126 | static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst) | |
127 | { | |
128 | unsigned long p = dst->_metrics; | |
129 | ||
1f37070d SH |
130 | BUG_ON(!p); |
131 | ||
62fa8a84 DM |
132 | if (p & DST_METRICS_READ_ONLY) |
133 | return dst->ops->cow_metrics(dst, p); | |
134 | return __DST_METRICS_PTR(p); | |
135 | } | |
136 | ||
137 | /* This may only be invoked before the entry has reached global | |
138 | * visibility. | |
139 | */ | |
140 | static inline void dst_init_metrics(struct dst_entry *dst, | |
141 | const u32 *src_metrics, | |
142 | bool read_only) | |
143 | { | |
144 | dst->_metrics = ((unsigned long) src_metrics) | | |
145 | (read_only ? DST_METRICS_READ_ONLY : 0); | |
146 | } | |
147 | ||
148 | static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src) | |
149 | { | |
150 | u32 *dst_metrics = dst_metrics_write_ptr(dest); | |
151 | ||
152 | if (dst_metrics) { | |
153 | u32 *src_metrics = DST_METRICS_PTR(src); | |
154 | ||
155 | memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32)); | |
156 | } | |
157 | } | |
158 | ||
159 | static inline u32 *dst_metrics_ptr(struct dst_entry *dst) | |
160 | { | |
161 | return DST_METRICS_PTR(dst); | |
162 | } | |
163 | ||
1da177e4 | 164 | static inline u32 |
5170ae82 | 165 | dst_metric_raw(const struct dst_entry *dst, const int metric) |
1da177e4 | 166 | { |
62fa8a84 DM |
167 | u32 *p = DST_METRICS_PTR(dst); |
168 | ||
169 | return p[metric-1]; | |
defb3519 DM |
170 | } |
171 | ||
5170ae82 DM |
172 | static inline u32 |
173 | dst_metric(const struct dst_entry *dst, const int metric) | |
174 | { | |
0dbaee3b | 175 | WARN_ON_ONCE(metric == RTAX_HOPLIMIT || |
d33e4553 DM |
176 | metric == RTAX_ADVMSS || |
177 | metric == RTAX_MTU); | |
5170ae82 DM |
178 | return dst_metric_raw(dst, metric); |
179 | } | |
180 | ||
0dbaee3b DM |
181 | static inline u32 |
182 | dst_metric_advmss(const struct dst_entry *dst) | |
183 | { | |
184 | u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS); | |
185 | ||
186 | if (!advmss) | |
187 | advmss = dst->ops->default_advmss(dst); | |
188 | ||
189 | return advmss; | |
190 | } | |
191 | ||
defb3519 DM |
192 | static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) |
193 | { | |
62fa8a84 | 194 | u32 *p = dst_metrics_write_ptr(dst); |
defb3519 | 195 | |
62fa8a84 DM |
196 | if (p) |
197 | p[metric-1] = val; | |
1da177e4 LT |
198 | } |
199 | ||
0c3adfb8 GBY |
200 | static inline u32 |
201 | dst_feature(const struct dst_entry *dst, u32 feature) | |
202 | { | |
bb5b7c11 | 203 | return dst_metric(dst, RTAX_FEATURES) & feature; |
0c3adfb8 GBY |
204 | } |
205 | ||
1da177e4 LT |
206 | static inline u32 dst_mtu(const struct dst_entry *dst) |
207 | { | |
d33e4553 DM |
208 | u32 mtu = dst_metric_raw(dst, RTAX_MTU); |
209 | ||
210 | if (!mtu) | |
ebb762f2 | 211 | mtu = dst->ops->mtu(dst); |
d33e4553 | 212 | |
1da177e4 LT |
213 | return mtu; |
214 | } | |
215 | ||
c1e20f7c SH |
216 | /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */ |
217 | static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric) | |
218 | { | |
219 | return msecs_to_jiffies(dst_metric(dst, metric)); | |
220 | } | |
221 | ||
222 | static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric, | |
223 | unsigned long rtt) | |
224 | { | |
defb3519 | 225 | dst_metric_set(dst, metric, jiffies_to_msecs(rtt)); |
c1e20f7c SH |
226 | } |
227 | ||
1da177e4 LT |
228 | static inline u32 |
229 | dst_allfrag(const struct dst_entry *dst) | |
230 | { | |
0c3adfb8 | 231 | int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG); |
1da177e4 LT |
232 | return ret; |
233 | } | |
234 | ||
235 | static inline int | |
d33e4553 | 236 | dst_metric_locked(const struct dst_entry *dst, int metric) |
1da177e4 LT |
237 | { |
238 | return dst_metric(dst, RTAX_LOCK) & (1<<metric); | |
239 | } | |
240 | ||
241 | static inline void dst_hold(struct dst_entry * dst) | |
242 | { | |
5635c10d ED |
243 | /* |
244 | * If your kernel compilation stops here, please check | |
245 | * __pad_to_align_refcnt declaration in struct dst_entry | |
246 | */ | |
247 | BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); | |
1da177e4 LT |
248 | atomic_inc(&dst->__refcnt); |
249 | } | |
250 | ||
03f49f34 PE |
251 | static inline void dst_use(struct dst_entry *dst, unsigned long time) |
252 | { | |
253 | dst_hold(dst); | |
254 | dst->__use++; | |
255 | dst->lastuse = time; | |
256 | } | |
257 | ||
7fee226a ED |
258 | static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) |
259 | { | |
260 | dst->__use++; | |
261 | dst->lastuse = time; | |
262 | } | |
263 | ||
1da177e4 LT |
264 | static inline |
265 | struct dst_entry * dst_clone(struct dst_entry * dst) | |
266 | { | |
267 | if (dst) | |
268 | atomic_inc(&dst->__refcnt); | |
269 | return dst; | |
270 | } | |
271 | ||
8d330868 | 272 | extern void dst_release(struct dst_entry *dst); |
7fee226a ED |
273 | |
274 | static inline void refdst_drop(unsigned long refdst) | |
275 | { | |
276 | if (!(refdst & SKB_DST_NOREF)) | |
277 | dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK)); | |
278 | } | |
279 | ||
280 | /** | |
281 | * skb_dst_drop - drops skb dst | |
282 | * @skb: buffer | |
283 | * | |
284 | * Drops dst reference count if a reference was taken. | |
285 | */ | |
adf30907 ED |
286 | static inline void skb_dst_drop(struct sk_buff *skb) |
287 | { | |
7fee226a ED |
288 | if (skb->_skb_refdst) { |
289 | refdst_drop(skb->_skb_refdst); | |
290 | skb->_skb_refdst = 0UL; | |
291 | } | |
292 | } | |
293 | ||
294 | static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb) | |
295 | { | |
296 | nskb->_skb_refdst = oskb->_skb_refdst; | |
297 | if (!(nskb->_skb_refdst & SKB_DST_NOREF)) | |
298 | dst_clone(skb_dst(nskb)); | |
299 | } | |
300 | ||
301 | /** | |
302 | * skb_dst_force - makes sure skb dst is refcounted | |
303 | * @skb: buffer | |
304 | * | |
305 | * If dst is not yet refcounted, let's do it | |
306 | */ | |
307 | static inline void skb_dst_force(struct sk_buff *skb) | |
308 | { | |
309 | if (skb_dst_is_noref(skb)) { | |
310 | WARN_ON(!rcu_read_lock_held()); | |
311 | skb->_skb_refdst &= ~SKB_DST_NOREF; | |
312 | dst_clone(skb_dst(skb)); | |
313 | } | |
adf30907 | 314 | } |
1da177e4 | 315 | |
d19d56dd | 316 | |
290b895e ED |
317 | /** |
318 | * __skb_tunnel_rx - prepare skb for rx reinsert | |
319 | * @skb: buffer | |
320 | * @dev: tunnel device | |
321 | * | |
322 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
323 | * so make some cleanups. (no accounting done) | |
324 | */ | |
325 | static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
326 | { | |
327 | skb->dev = dev; | |
bdeab991 TH |
328 | |
329 | /* | |
330 | * Clear rxhash so that we can recalulate the hash for the | |
331 | * encapsulated packet, unless we have already determine the hash | |
332 | * over the L4 4-tuple. | |
333 | */ | |
334 | if (!skb->l4_rxhash) | |
335 | skb->rxhash = 0; | |
290b895e ED |
336 | skb_set_queue_mapping(skb, 0); |
337 | skb_dst_drop(skb); | |
338 | nf_reset(skb); | |
339 | } | |
340 | ||
d19d56dd ED |
341 | /** |
342 | * skb_tunnel_rx - prepare skb for rx reinsert | |
343 | * @skb: buffer | |
344 | * @dev: tunnel device | |
345 | * | |
346 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
347 | * so make some cleanups, and perform accounting. | |
290b895e | 348 | * Note: this accounting is not SMP safe. |
d19d56dd ED |
349 | */ |
350 | static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
351 | { | |
d19d56dd ED |
352 | /* TODO : stats should be SMP safe */ |
353 | dev->stats.rx_packets++; | |
354 | dev->stats.rx_bytes += skb->len; | |
290b895e | 355 | __skb_tunnel_rx(skb, dev); |
d19d56dd ED |
356 | } |
357 | ||
1da177e4 LT |
358 | /* Children define the path of the packet through the |
359 | * Linux networking. Thus, destinations are stackable. | |
360 | */ | |
361 | ||
8764ab2c | 362 | static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb) |
1da177e4 | 363 | { |
e433430a | 364 | struct dst_entry *child = dst_clone(skb_dst(skb)->child); |
1da177e4 | 365 | |
8764ab2c | 366 | skb_dst_drop(skb); |
1da177e4 LT |
367 | return child; |
368 | } | |
369 | ||
352e512c | 370 | extern int dst_discard(struct sk_buff *skb); |
5c1e6aa3 DM |
371 | extern void *dst_alloc(struct dst_ops * ops, struct net_device *dev, |
372 | int initial_ref, int initial_obsolete, int flags); | |
1da177e4 LT |
373 | extern void __dst_free(struct dst_entry * dst); |
374 | extern struct dst_entry *dst_destroy(struct dst_entry * dst); | |
375 | ||
376 | static inline void dst_free(struct dst_entry * dst) | |
377 | { | |
378 | if (dst->obsolete > 1) | |
379 | return; | |
380 | if (!atomic_read(&dst->__refcnt)) { | |
381 | dst = dst_destroy(dst); | |
382 | if (!dst) | |
383 | return; | |
384 | } | |
385 | __dst_free(dst); | |
386 | } | |
387 | ||
388 | static inline void dst_rcu_free(struct rcu_head *head) | |
389 | { | |
390 | struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); | |
391 | dst_free(dst); | |
392 | } | |
393 | ||
394 | static inline void dst_confirm(struct dst_entry *dst) | |
395 | { | |
69cce1d1 | 396 | if (dst) { |
f2c31e32 ED |
397 | struct neighbour *n; |
398 | ||
399 | rcu_read_lock(); | |
400 | n = dst_get_neighbour(dst); | |
69cce1d1 | 401 | neigh_confirm(n); |
f2c31e32 | 402 | rcu_read_unlock(); |
69cce1d1 | 403 | } |
1da177e4 LT |
404 | } |
405 | ||
d3aaeb38 DM |
406 | static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr) |
407 | { | |
408 | return dst->ops->neigh_lookup(dst, daddr); | |
409 | } | |
410 | ||
1da177e4 LT |
411 | static inline void dst_link_failure(struct sk_buff *skb) |
412 | { | |
adf30907 | 413 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
414 | if (dst && dst->ops && dst->ops->link_failure) |
415 | dst->ops->link_failure(skb); | |
416 | } | |
417 | ||
418 | static inline void dst_set_expires(struct dst_entry *dst, int timeout) | |
419 | { | |
420 | unsigned long expires = jiffies + timeout; | |
421 | ||
422 | if (expires == 0) | |
423 | expires = 1; | |
424 | ||
425 | if (dst->expires == 0 || time_before(expires, dst->expires)) | |
426 | dst->expires = expires; | |
427 | } | |
428 | ||
429 | /* Output packet to network from transport. */ | |
430 | static inline int dst_output(struct sk_buff *skb) | |
431 | { | |
adf30907 | 432 | return skb_dst(skb)->output(skb); |
1da177e4 LT |
433 | } |
434 | ||
435 | /* Input packet from network to transport. */ | |
436 | static inline int dst_input(struct sk_buff *skb) | |
437 | { | |
adf30907 | 438 | return skb_dst(skb)->input(skb); |
1da177e4 LT |
439 | } |
440 | ||
441 | static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie) | |
442 | { | |
443 | if (dst->obsolete) | |
444 | dst = dst->ops->check(dst, cookie); | |
445 | return dst; | |
446 | } | |
447 | ||
448 | extern void dst_init(void); | |
449 | ||
815f4e57 HX |
450 | /* Flags for xfrm_lookup flags argument. */ |
451 | enum { | |
80c0bc9e | 452 | XFRM_LOOKUP_ICMP = 1 << 0, |
815f4e57 HX |
453 | }; |
454 | ||
1da177e4 LT |
455 | struct flowi; |
456 | #ifndef CONFIG_XFRM | |
452edd59 DM |
457 | static inline struct dst_entry *xfrm_lookup(struct net *net, |
458 | struct dst_entry *dst_orig, | |
459 | const struct flowi *fl, struct sock *sk, | |
460 | int flags) | |
1da177e4 | 461 | { |
452edd59 | 462 | return dst_orig; |
1da177e4 LT |
463 | } |
464 | #else | |
452edd59 DM |
465 | extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig, |
466 | const struct flowi *fl, struct sock *sk, | |
467 | int flags); | |
1da177e4 | 468 | #endif |
1da177e4 LT |
469 | |
470 | #endif /* _NET_DST_H */ |