Commit | Line | Data |
---|---|---|
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> | |
187f1882 | 15 | #include <linux/bug.h> |
1da177e4 LT |
16 | #include <linux/jiffies.h> |
17 | #include <net/neighbour.h> | |
18 | #include <asm/processor.h> | |
19 | ||
1da177e4 LT |
20 | #define DST_GC_MIN (HZ/10) |
21 | #define DST_GC_INC (HZ/2) | |
22 | #define DST_GC_MAX (120*HZ) | |
23 | ||
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. | |
29 | */ | |
30 | ||
31 | struct sk_buff; | |
32 | ||
fd2c3ef7 | 33 | struct dst_entry { |
1e19e02c | 34 | struct rcu_head rcu_head; |
1da177e4 LT |
35 | struct dst_entry *child; |
36 | struct net_device *dev; | |
62fa8a84 DM |
37 | struct dst_ops *ops; |
38 | unsigned long _metrics; | |
1716a961 G |
39 | union { |
40 | unsigned long expires; | |
41 | /* point to where the dst_entry copied from */ | |
42 | struct dst_entry *from; | |
43 | }; | |
f1dd9c37 | 44 | struct dst_entry *path; |
f2c31e32 | 45 | struct neighbour __rcu *_neighbour; |
def8b4fa | 46 | #ifdef CONFIG_XFRM |
1da177e4 | 47 | struct xfrm_state *xfrm; |
5635c10d ED |
48 | #else |
49 | void *__pad1; | |
def8b4fa | 50 | #endif |
7f95e188 EZ |
51 | int (*input)(struct sk_buff *); |
52 | int (*output)(struct sk_buff *); | |
1da177e4 | 53 | |
5110effe | 54 | unsigned short flags; |
f6b72b62 DM |
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 | |
e688a604 | 61 | #define DST_NOPEER 0x0040 |
a881e963 | 62 | #define DST_FAKE_RTABLE 0x0080 |
0c183379 | 63 | #define DST_XFRM_TUNNEL 0x0100 |
f6b72b62 | 64 | |
5110effe DM |
65 | unsigned short pending_confirm; |
66 | ||
62fa8a84 DM |
67 | short error; |
68 | short obsolete; | |
69 | unsigned short header_len; /* more space at head required */ | |
70 | unsigned short trailer_len; /* space to reserve at tail */ | |
c7066f70 | 71 | #ifdef CONFIG_IP_ROUTE_CLASSID |
f1dd9c37 | 72 | __u32 tclassid; |
5635c10d ED |
73 | #else |
74 | __u32 __pad2; | |
f1dd9c37 ZY |
75 | #endif |
76 | ||
5635c10d ED |
77 | /* |
78 | * Align __refcnt to a 64 bytes alignment | |
79 | * (L1_CACHE_SIZE would be too much) | |
80 | */ | |
81 | #ifdef CONFIG_64BIT | |
f6b72b62 | 82 | long __pad_to_align_refcnt[2]; |
5635c10d | 83 | #endif |
f1dd9c37 ZY |
84 | /* |
85 | * __refcnt wants to be on a different cache line from | |
86 | * input/output/ops or performance tanks badly | |
87 | */ | |
1e19e02c ED |
88 | atomic_t __refcnt; /* client references */ |
89 | int __use; | |
f1dd9c37 | 90 | unsigned long lastuse; |
1e19e02c | 91 | union { |
fc766e4c ED |
92 | struct dst_entry *next; |
93 | struct rtable __rcu *rt_next; | |
94 | struct rt6_info *rt6_next; | |
95 | struct dn_route __rcu *dn_next; | |
1e19e02c | 96 | }; |
1da177e4 LT |
97 | }; |
98 | ||
27217455 | 99 | static inline struct neighbour *dst_get_neighbour_noref(struct dst_entry *dst) |
69cce1d1 | 100 | { |
f2c31e32 ED |
101 | return rcu_dereference(dst->_neighbour); |
102 | } | |
103 | ||
27217455 | 104 | static inline struct neighbour *dst_get_neighbour_noref_raw(struct dst_entry *dst) |
f2c31e32 ED |
105 | { |
106 | return rcu_dereference_raw(dst->_neighbour); | |
69cce1d1 DM |
107 | } |
108 | ||
109 | static inline void dst_set_neighbour(struct dst_entry *dst, struct neighbour *neigh) | |
110 | { | |
f2c31e32 | 111 | rcu_assign_pointer(dst->_neighbour, neigh); |
69cce1d1 DM |
112 | } |
113 | ||
62fa8a84 | 114 | extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old); |
725d1e1b | 115 | extern const u32 dst_default_metrics[RTAX_MAX]; |
62fa8a84 DM |
116 | |
117 | #define DST_METRICS_READ_ONLY 0x1UL | |
118 | #define __DST_METRICS_PTR(Y) \ | |
119 | ((u32 *)((Y) & ~DST_METRICS_READ_ONLY)) | |
120 | #define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics) | |
121 | ||
122 | static inline bool dst_metrics_read_only(const struct dst_entry *dst) | |
123 | { | |
124 | return dst->_metrics & DST_METRICS_READ_ONLY; | |
125 | } | |
126 | ||
127 | extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old); | |
128 | ||
129 | static inline void dst_destroy_metrics_generic(struct dst_entry *dst) | |
130 | { | |
131 | unsigned long val = dst->_metrics; | |
132 | if (!(val & DST_METRICS_READ_ONLY)) | |
133 | __dst_destroy_metrics_generic(dst, val); | |
134 | } | |
135 | ||
136 | static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst) | |
137 | { | |
138 | unsigned long p = dst->_metrics; | |
139 | ||
1f37070d SH |
140 | BUG_ON(!p); |
141 | ||
62fa8a84 DM |
142 | if (p & DST_METRICS_READ_ONLY) |
143 | return dst->ops->cow_metrics(dst, p); | |
144 | return __DST_METRICS_PTR(p); | |
145 | } | |
146 | ||
147 | /* This may only be invoked before the entry has reached global | |
148 | * visibility. | |
149 | */ | |
150 | static inline void dst_init_metrics(struct dst_entry *dst, | |
151 | const u32 *src_metrics, | |
152 | bool read_only) | |
153 | { | |
154 | dst->_metrics = ((unsigned long) src_metrics) | | |
155 | (read_only ? DST_METRICS_READ_ONLY : 0); | |
156 | } | |
157 | ||
158 | static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src) | |
159 | { | |
160 | u32 *dst_metrics = dst_metrics_write_ptr(dest); | |
161 | ||
162 | if (dst_metrics) { | |
163 | u32 *src_metrics = DST_METRICS_PTR(src); | |
164 | ||
165 | memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32)); | |
166 | } | |
167 | } | |
168 | ||
169 | static inline u32 *dst_metrics_ptr(struct dst_entry *dst) | |
170 | { | |
171 | return DST_METRICS_PTR(dst); | |
172 | } | |
173 | ||
1da177e4 | 174 | static inline u32 |
5170ae82 | 175 | dst_metric_raw(const struct dst_entry *dst, const int metric) |
1da177e4 | 176 | { |
62fa8a84 DM |
177 | u32 *p = DST_METRICS_PTR(dst); |
178 | ||
179 | return p[metric-1]; | |
defb3519 DM |
180 | } |
181 | ||
5170ae82 DM |
182 | static inline u32 |
183 | dst_metric(const struct dst_entry *dst, const int metric) | |
184 | { | |
0dbaee3b | 185 | WARN_ON_ONCE(metric == RTAX_HOPLIMIT || |
d33e4553 DM |
186 | metric == RTAX_ADVMSS || |
187 | metric == RTAX_MTU); | |
5170ae82 DM |
188 | return dst_metric_raw(dst, metric); |
189 | } | |
190 | ||
0dbaee3b DM |
191 | static inline u32 |
192 | dst_metric_advmss(const struct dst_entry *dst) | |
193 | { | |
194 | u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS); | |
195 | ||
196 | if (!advmss) | |
197 | advmss = dst->ops->default_advmss(dst); | |
198 | ||
199 | return advmss; | |
200 | } | |
201 | ||
defb3519 DM |
202 | static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) |
203 | { | |
62fa8a84 | 204 | u32 *p = dst_metrics_write_ptr(dst); |
defb3519 | 205 | |
62fa8a84 DM |
206 | if (p) |
207 | p[metric-1] = val; | |
1da177e4 LT |
208 | } |
209 | ||
0c3adfb8 GBY |
210 | static inline u32 |
211 | dst_feature(const struct dst_entry *dst, u32 feature) | |
212 | { | |
bb5b7c11 | 213 | return dst_metric(dst, RTAX_FEATURES) & feature; |
0c3adfb8 GBY |
214 | } |
215 | ||
1da177e4 LT |
216 | static inline u32 dst_mtu(const struct dst_entry *dst) |
217 | { | |
618f9bc7 | 218 | return dst->ops->mtu(dst); |
1da177e4 LT |
219 | } |
220 | ||
c1e20f7c SH |
221 | /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */ |
222 | static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric) | |
223 | { | |
224 | return msecs_to_jiffies(dst_metric(dst, metric)); | |
225 | } | |
226 | ||
227 | static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric, | |
228 | unsigned long rtt) | |
229 | { | |
defb3519 | 230 | dst_metric_set(dst, metric, jiffies_to_msecs(rtt)); |
c1e20f7c SH |
231 | } |
232 | ||
1da177e4 LT |
233 | static inline u32 |
234 | dst_allfrag(const struct dst_entry *dst) | |
235 | { | |
0c3adfb8 | 236 | int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG); |
1da177e4 LT |
237 | return ret; |
238 | } | |
239 | ||
240 | static inline int | |
d33e4553 | 241 | dst_metric_locked(const struct dst_entry *dst, int metric) |
1da177e4 LT |
242 | { |
243 | return dst_metric(dst, RTAX_LOCK) & (1<<metric); | |
244 | } | |
245 | ||
7f95e188 | 246 | static inline void dst_hold(struct dst_entry *dst) |
1da177e4 | 247 | { |
5635c10d ED |
248 | /* |
249 | * If your kernel compilation stops here, please check | |
250 | * __pad_to_align_refcnt declaration in struct dst_entry | |
251 | */ | |
252 | BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); | |
1da177e4 LT |
253 | atomic_inc(&dst->__refcnt); |
254 | } | |
255 | ||
03f49f34 PE |
256 | static inline void dst_use(struct dst_entry *dst, unsigned long time) |
257 | { | |
258 | dst_hold(dst); | |
259 | dst->__use++; | |
260 | dst->lastuse = time; | |
261 | } | |
262 | ||
7fee226a ED |
263 | static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) |
264 | { | |
265 | dst->__use++; | |
266 | dst->lastuse = time; | |
267 | } | |
268 | ||
7f95e188 | 269 | static inline struct dst_entry *dst_clone(struct dst_entry *dst) |
1da177e4 LT |
270 | { |
271 | if (dst) | |
272 | atomic_inc(&dst->__refcnt); | |
273 | return dst; | |
274 | } | |
275 | ||
8d330868 | 276 | extern void dst_release(struct dst_entry *dst); |
7fee226a ED |
277 | |
278 | static inline void refdst_drop(unsigned long refdst) | |
279 | { | |
280 | if (!(refdst & SKB_DST_NOREF)) | |
281 | dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK)); | |
282 | } | |
283 | ||
284 | /** | |
285 | * skb_dst_drop - drops skb dst | |
286 | * @skb: buffer | |
287 | * | |
288 | * Drops dst reference count if a reference was taken. | |
289 | */ | |
adf30907 ED |
290 | static inline void skb_dst_drop(struct sk_buff *skb) |
291 | { | |
7fee226a ED |
292 | if (skb->_skb_refdst) { |
293 | refdst_drop(skb->_skb_refdst); | |
294 | skb->_skb_refdst = 0UL; | |
295 | } | |
296 | } | |
297 | ||
298 | static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb) | |
299 | { | |
300 | nskb->_skb_refdst = oskb->_skb_refdst; | |
301 | if (!(nskb->_skb_refdst & SKB_DST_NOREF)) | |
302 | dst_clone(skb_dst(nskb)); | |
303 | } | |
304 | ||
305 | /** | |
306 | * skb_dst_force - makes sure skb dst is refcounted | |
307 | * @skb: buffer | |
308 | * | |
309 | * If dst is not yet refcounted, let's do it | |
310 | */ | |
311 | static inline void skb_dst_force(struct sk_buff *skb) | |
312 | { | |
313 | if (skb_dst_is_noref(skb)) { | |
314 | WARN_ON(!rcu_read_lock_held()); | |
315 | skb->_skb_refdst &= ~SKB_DST_NOREF; | |
316 | dst_clone(skb_dst(skb)); | |
317 | } | |
adf30907 | 318 | } |
1da177e4 | 319 | |
d19d56dd | 320 | |
290b895e ED |
321 | /** |
322 | * __skb_tunnel_rx - prepare skb for rx reinsert | |
323 | * @skb: buffer | |
324 | * @dev: tunnel device | |
325 | * | |
326 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
327 | * so make some cleanups. (no accounting done) | |
328 | */ | |
329 | static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
330 | { | |
331 | skb->dev = dev; | |
bdeab991 TH |
332 | |
333 | /* | |
334 | * Clear rxhash so that we can recalulate the hash for the | |
335 | * encapsulated packet, unless we have already determine the hash | |
336 | * over the L4 4-tuple. | |
337 | */ | |
338 | if (!skb->l4_rxhash) | |
339 | skb->rxhash = 0; | |
290b895e ED |
340 | skb_set_queue_mapping(skb, 0); |
341 | skb_dst_drop(skb); | |
342 | nf_reset(skb); | |
343 | } | |
344 | ||
d19d56dd ED |
345 | /** |
346 | * skb_tunnel_rx - prepare skb for rx reinsert | |
347 | * @skb: buffer | |
348 | * @dev: tunnel device | |
349 | * | |
350 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
351 | * so make some cleanups, and perform accounting. | |
290b895e | 352 | * Note: this accounting is not SMP safe. |
d19d56dd ED |
353 | */ |
354 | static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
355 | { | |
d19d56dd ED |
356 | /* TODO : stats should be SMP safe */ |
357 | dev->stats.rx_packets++; | |
358 | dev->stats.rx_bytes += skb->len; | |
290b895e | 359 | __skb_tunnel_rx(skb, dev); |
d19d56dd ED |
360 | } |
361 | ||
1da177e4 LT |
362 | /* Children define the path of the packet through the |
363 | * Linux networking. Thus, destinations are stackable. | |
364 | */ | |
365 | ||
8764ab2c | 366 | static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb) |
1da177e4 | 367 | { |
e433430a | 368 | struct dst_entry *child = dst_clone(skb_dst(skb)->child); |
1da177e4 | 369 | |
8764ab2c | 370 | skb_dst_drop(skb); |
1da177e4 LT |
371 | return child; |
372 | } | |
373 | ||
352e512c | 374 | extern int dst_discard(struct sk_buff *skb); |
7f95e188 | 375 | extern void *dst_alloc(struct dst_ops *ops, struct net_device *dev, |
5110effe DM |
376 | int initial_ref, int initial_obsolete, |
377 | unsigned short flags); | |
7f95e188 EZ |
378 | extern void __dst_free(struct dst_entry *dst); |
379 | extern struct dst_entry *dst_destroy(struct dst_entry *dst); | |
1da177e4 | 380 | |
7f95e188 | 381 | static inline void dst_free(struct dst_entry *dst) |
1da177e4 LT |
382 | { |
383 | if (dst->obsolete > 1) | |
384 | return; | |
385 | if (!atomic_read(&dst->__refcnt)) { | |
386 | dst = dst_destroy(dst); | |
387 | if (!dst) | |
388 | return; | |
389 | } | |
390 | __dst_free(dst); | |
391 | } | |
392 | ||
393 | static inline void dst_rcu_free(struct rcu_head *head) | |
394 | { | |
395 | struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); | |
396 | dst_free(dst); | |
397 | } | |
398 | ||
399 | static inline void dst_confirm(struct dst_entry *dst) | |
400 | { | |
5110effe DM |
401 | dst->pending_confirm = 1; |
402 | } | |
f2c31e32 | 403 | |
5110effe DM |
404 | static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n, |
405 | struct sk_buff *skb) | |
406 | { | |
407 | struct hh_cache *hh; | |
408 | ||
409 | if (unlikely(dst->pending_confirm)) { | |
410 | n->confirmed = jiffies; | |
411 | dst->pending_confirm = 0; | |
69cce1d1 | 412 | } |
5110effe DM |
413 | |
414 | hh = &n->hh; | |
415 | if ((n->nud_state & NUD_CONNECTED) && hh->hh_len) | |
416 | return neigh_hh_output(hh, skb); | |
417 | else | |
418 | return n->output(n, skb); | |
1da177e4 LT |
419 | } |
420 | ||
d3aaeb38 DM |
421 | static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr) |
422 | { | |
423 | return dst->ops->neigh_lookup(dst, daddr); | |
424 | } | |
425 | ||
1da177e4 LT |
426 | static inline void dst_link_failure(struct sk_buff *skb) |
427 | { | |
adf30907 | 428 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
429 | if (dst && dst->ops && dst->ops->link_failure) |
430 | dst->ops->link_failure(skb); | |
431 | } | |
432 | ||
433 | static inline void dst_set_expires(struct dst_entry *dst, int timeout) | |
434 | { | |
435 | unsigned long expires = jiffies + timeout; | |
436 | ||
437 | if (expires == 0) | |
438 | expires = 1; | |
439 | ||
440 | if (dst->expires == 0 || time_before(expires, dst->expires)) | |
441 | dst->expires = expires; | |
442 | } | |
443 | ||
444 | /* Output packet to network from transport. */ | |
445 | static inline int dst_output(struct sk_buff *skb) | |
446 | { | |
adf30907 | 447 | return skb_dst(skb)->output(skb); |
1da177e4 LT |
448 | } |
449 | ||
450 | /* Input packet from network to transport. */ | |
451 | static inline int dst_input(struct sk_buff *skb) | |
452 | { | |
adf30907 | 453 | return skb_dst(skb)->input(skb); |
1da177e4 LT |
454 | } |
455 | ||
456 | static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie) | |
457 | { | |
458 | if (dst->obsolete) | |
459 | dst = dst->ops->check(dst, cookie); | |
460 | return dst; | |
461 | } | |
462 | ||
463 | extern void dst_init(void); | |
464 | ||
815f4e57 HX |
465 | /* Flags for xfrm_lookup flags argument. */ |
466 | enum { | |
80c0bc9e | 467 | XFRM_LOOKUP_ICMP = 1 << 0, |
815f4e57 HX |
468 | }; |
469 | ||
1da177e4 LT |
470 | struct flowi; |
471 | #ifndef CONFIG_XFRM | |
452edd59 DM |
472 | static inline struct dst_entry *xfrm_lookup(struct net *net, |
473 | struct dst_entry *dst_orig, | |
474 | const struct flowi *fl, struct sock *sk, | |
475 | int flags) | |
1da177e4 | 476 | { |
452edd59 | 477 | return dst_orig; |
1da177e4 LT |
478 | } |
479 | #else | |
452edd59 DM |
480 | extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig, |
481 | const struct flowi *fl, struct sock *sk, | |
482 | int flags); | |
1da177e4 | 483 | #endif |
1da177e4 LT |
484 | |
485 | #endif /* _NET_DST_H */ |