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 | |
f6b72b62 DM |
54 | int flags; |
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 | |
62fa8a84 DM |
65 | short error; |
66 | short obsolete; | |
67 | unsigned short header_len; /* more space at head required */ | |
68 | unsigned short trailer_len; /* space to reserve at tail */ | |
c7066f70 | 69 | #ifdef CONFIG_IP_ROUTE_CLASSID |
f1dd9c37 | 70 | __u32 tclassid; |
5635c10d ED |
71 | #else |
72 | __u32 __pad2; | |
f1dd9c37 ZY |
73 | #endif |
74 | ||
5635c10d ED |
75 | /* |
76 | * Align __refcnt to a 64 bytes alignment | |
77 | * (L1_CACHE_SIZE would be too much) | |
78 | */ | |
79 | #ifdef CONFIG_64BIT | |
f6b72b62 | 80 | long __pad_to_align_refcnt[2]; |
5635c10d | 81 | #endif |
f1dd9c37 ZY |
82 | /* |
83 | * __refcnt wants to be on a different cache line from | |
84 | * input/output/ops or performance tanks badly | |
85 | */ | |
1e19e02c ED |
86 | atomic_t __refcnt; /* client references */ |
87 | int __use; | |
f1dd9c37 | 88 | unsigned long lastuse; |
1e19e02c | 89 | union { |
fc766e4c ED |
90 | struct dst_entry *next; |
91 | struct rtable __rcu *rt_next; | |
92 | struct rt6_info *rt6_next; | |
93 | struct dn_route __rcu *dn_next; | |
1e19e02c | 94 | }; |
1da177e4 LT |
95 | }; |
96 | ||
27217455 | 97 | static inline struct neighbour *dst_get_neighbour_noref(struct dst_entry *dst) |
69cce1d1 | 98 | { |
f2c31e32 ED |
99 | return rcu_dereference(dst->_neighbour); |
100 | } | |
101 | ||
27217455 | 102 | static inline struct neighbour *dst_get_neighbour_noref_raw(struct dst_entry *dst) |
f2c31e32 ED |
103 | { |
104 | return rcu_dereference_raw(dst->_neighbour); | |
69cce1d1 DM |
105 | } |
106 | ||
107 | static inline void dst_set_neighbour(struct dst_entry *dst, struct neighbour *neigh) | |
108 | { | |
f2c31e32 | 109 | rcu_assign_pointer(dst->_neighbour, neigh); |
69cce1d1 DM |
110 | } |
111 | ||
62fa8a84 | 112 | extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old); |
725d1e1b | 113 | extern const u32 dst_default_metrics[RTAX_MAX]; |
62fa8a84 DM |
114 | |
115 | #define DST_METRICS_READ_ONLY 0x1UL | |
116 | #define __DST_METRICS_PTR(Y) \ | |
117 | ((u32 *)((Y) & ~DST_METRICS_READ_ONLY)) | |
118 | #define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics) | |
119 | ||
120 | static inline bool dst_metrics_read_only(const struct dst_entry *dst) | |
121 | { | |
122 | return dst->_metrics & DST_METRICS_READ_ONLY; | |
123 | } | |
124 | ||
125 | extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old); | |
126 | ||
127 | static inline void dst_destroy_metrics_generic(struct dst_entry *dst) | |
128 | { | |
129 | unsigned long val = dst->_metrics; | |
130 | if (!(val & DST_METRICS_READ_ONLY)) | |
131 | __dst_destroy_metrics_generic(dst, val); | |
132 | } | |
133 | ||
134 | static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst) | |
135 | { | |
136 | unsigned long p = dst->_metrics; | |
137 | ||
1f37070d SH |
138 | BUG_ON(!p); |
139 | ||
62fa8a84 DM |
140 | if (p & DST_METRICS_READ_ONLY) |
141 | return dst->ops->cow_metrics(dst, p); | |
142 | return __DST_METRICS_PTR(p); | |
143 | } | |
144 | ||
145 | /* This may only be invoked before the entry has reached global | |
146 | * visibility. | |
147 | */ | |
148 | static inline void dst_init_metrics(struct dst_entry *dst, | |
149 | const u32 *src_metrics, | |
150 | bool read_only) | |
151 | { | |
152 | dst->_metrics = ((unsigned long) src_metrics) | | |
153 | (read_only ? DST_METRICS_READ_ONLY : 0); | |
154 | } | |
155 | ||
156 | static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src) | |
157 | { | |
158 | u32 *dst_metrics = dst_metrics_write_ptr(dest); | |
159 | ||
160 | if (dst_metrics) { | |
161 | u32 *src_metrics = DST_METRICS_PTR(src); | |
162 | ||
163 | memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32)); | |
164 | } | |
165 | } | |
166 | ||
167 | static inline u32 *dst_metrics_ptr(struct dst_entry *dst) | |
168 | { | |
169 | return DST_METRICS_PTR(dst); | |
170 | } | |
171 | ||
1da177e4 | 172 | static inline u32 |
5170ae82 | 173 | dst_metric_raw(const struct dst_entry *dst, const int metric) |
1da177e4 | 174 | { |
62fa8a84 DM |
175 | u32 *p = DST_METRICS_PTR(dst); |
176 | ||
177 | return p[metric-1]; | |
defb3519 DM |
178 | } |
179 | ||
5170ae82 DM |
180 | static inline u32 |
181 | dst_metric(const struct dst_entry *dst, const int metric) | |
182 | { | |
0dbaee3b | 183 | WARN_ON_ONCE(metric == RTAX_HOPLIMIT || |
d33e4553 DM |
184 | metric == RTAX_ADVMSS || |
185 | metric == RTAX_MTU); | |
5170ae82 DM |
186 | return dst_metric_raw(dst, metric); |
187 | } | |
188 | ||
0dbaee3b DM |
189 | static inline u32 |
190 | dst_metric_advmss(const struct dst_entry *dst) | |
191 | { | |
192 | u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS); | |
193 | ||
194 | if (!advmss) | |
195 | advmss = dst->ops->default_advmss(dst); | |
196 | ||
197 | return advmss; | |
198 | } | |
199 | ||
defb3519 DM |
200 | static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) |
201 | { | |
62fa8a84 | 202 | u32 *p = dst_metrics_write_ptr(dst); |
defb3519 | 203 | |
62fa8a84 DM |
204 | if (p) |
205 | p[metric-1] = val; | |
1da177e4 LT |
206 | } |
207 | ||
0c3adfb8 GBY |
208 | static inline u32 |
209 | dst_feature(const struct dst_entry *dst, u32 feature) | |
210 | { | |
bb5b7c11 | 211 | return dst_metric(dst, RTAX_FEATURES) & feature; |
0c3adfb8 GBY |
212 | } |
213 | ||
1da177e4 LT |
214 | static inline u32 dst_mtu(const struct dst_entry *dst) |
215 | { | |
618f9bc7 | 216 | return dst->ops->mtu(dst); |
1da177e4 LT |
217 | } |
218 | ||
c1e20f7c SH |
219 | /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */ |
220 | static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric) | |
221 | { | |
222 | return msecs_to_jiffies(dst_metric(dst, metric)); | |
223 | } | |
224 | ||
225 | static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric, | |
226 | unsigned long rtt) | |
227 | { | |
defb3519 | 228 | dst_metric_set(dst, metric, jiffies_to_msecs(rtt)); |
c1e20f7c SH |
229 | } |
230 | ||
1da177e4 LT |
231 | static inline u32 |
232 | dst_allfrag(const struct dst_entry *dst) | |
233 | { | |
0c3adfb8 | 234 | int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG); |
1da177e4 LT |
235 | return ret; |
236 | } | |
237 | ||
238 | static inline int | |
d33e4553 | 239 | dst_metric_locked(const struct dst_entry *dst, int metric) |
1da177e4 LT |
240 | { |
241 | return dst_metric(dst, RTAX_LOCK) & (1<<metric); | |
242 | } | |
243 | ||
7f95e188 | 244 | static inline void dst_hold(struct dst_entry *dst) |
1da177e4 | 245 | { |
5635c10d ED |
246 | /* |
247 | * If your kernel compilation stops here, please check | |
248 | * __pad_to_align_refcnt declaration in struct dst_entry | |
249 | */ | |
250 | BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); | |
1da177e4 LT |
251 | atomic_inc(&dst->__refcnt); |
252 | } | |
253 | ||
03f49f34 PE |
254 | static inline void dst_use(struct dst_entry *dst, unsigned long time) |
255 | { | |
256 | dst_hold(dst); | |
257 | dst->__use++; | |
258 | dst->lastuse = time; | |
259 | } | |
260 | ||
7fee226a ED |
261 | static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) |
262 | { | |
263 | dst->__use++; | |
264 | dst->lastuse = time; | |
265 | } | |
266 | ||
7f95e188 | 267 | static inline struct dst_entry *dst_clone(struct dst_entry *dst) |
1da177e4 LT |
268 | { |
269 | if (dst) | |
270 | atomic_inc(&dst->__refcnt); | |
271 | return dst; | |
272 | } | |
273 | ||
8d330868 | 274 | extern void dst_release(struct dst_entry *dst); |
7fee226a ED |
275 | |
276 | static inline void refdst_drop(unsigned long refdst) | |
277 | { | |
278 | if (!(refdst & SKB_DST_NOREF)) | |
279 | dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK)); | |
280 | } | |
281 | ||
282 | /** | |
283 | * skb_dst_drop - drops skb dst | |
284 | * @skb: buffer | |
285 | * | |
286 | * Drops dst reference count if a reference was taken. | |
287 | */ | |
adf30907 ED |
288 | static inline void skb_dst_drop(struct sk_buff *skb) |
289 | { | |
7fee226a ED |
290 | if (skb->_skb_refdst) { |
291 | refdst_drop(skb->_skb_refdst); | |
292 | skb->_skb_refdst = 0UL; | |
293 | } | |
294 | } | |
295 | ||
296 | static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb) | |
297 | { | |
298 | nskb->_skb_refdst = oskb->_skb_refdst; | |
299 | if (!(nskb->_skb_refdst & SKB_DST_NOREF)) | |
300 | dst_clone(skb_dst(nskb)); | |
301 | } | |
302 | ||
303 | /** | |
304 | * skb_dst_force - makes sure skb dst is refcounted | |
305 | * @skb: buffer | |
306 | * | |
307 | * If dst is not yet refcounted, let's do it | |
308 | */ | |
309 | static inline void skb_dst_force(struct sk_buff *skb) | |
310 | { | |
311 | if (skb_dst_is_noref(skb)) { | |
312 | WARN_ON(!rcu_read_lock_held()); | |
313 | skb->_skb_refdst &= ~SKB_DST_NOREF; | |
314 | dst_clone(skb_dst(skb)); | |
315 | } | |
adf30907 | 316 | } |
1da177e4 | 317 | |
d19d56dd | 318 | |
290b895e ED |
319 | /** |
320 | * __skb_tunnel_rx - prepare skb for rx reinsert | |
321 | * @skb: buffer | |
322 | * @dev: tunnel device | |
323 | * | |
324 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
325 | * so make some cleanups. (no accounting done) | |
326 | */ | |
327 | static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
328 | { | |
329 | skb->dev = dev; | |
bdeab991 TH |
330 | |
331 | /* | |
332 | * Clear rxhash so that we can recalulate the hash for the | |
333 | * encapsulated packet, unless we have already determine the hash | |
334 | * over the L4 4-tuple. | |
335 | */ | |
336 | if (!skb->l4_rxhash) | |
337 | skb->rxhash = 0; | |
290b895e ED |
338 | skb_set_queue_mapping(skb, 0); |
339 | skb_dst_drop(skb); | |
340 | nf_reset(skb); | |
341 | } | |
342 | ||
d19d56dd ED |
343 | /** |
344 | * skb_tunnel_rx - prepare skb for rx reinsert | |
345 | * @skb: buffer | |
346 | * @dev: tunnel device | |
347 | * | |
348 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
349 | * so make some cleanups, and perform accounting. | |
290b895e | 350 | * Note: this accounting is not SMP safe. |
d19d56dd ED |
351 | */ |
352 | static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
353 | { | |
d19d56dd ED |
354 | /* TODO : stats should be SMP safe */ |
355 | dev->stats.rx_packets++; | |
356 | dev->stats.rx_bytes += skb->len; | |
290b895e | 357 | __skb_tunnel_rx(skb, dev); |
d19d56dd ED |
358 | } |
359 | ||
1da177e4 LT |
360 | /* Children define the path of the packet through the |
361 | * Linux networking. Thus, destinations are stackable. | |
362 | */ | |
363 | ||
8764ab2c | 364 | static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb) |
1da177e4 | 365 | { |
e433430a | 366 | struct dst_entry *child = dst_clone(skb_dst(skb)->child); |
1da177e4 | 367 | |
8764ab2c | 368 | skb_dst_drop(skb); |
1da177e4 LT |
369 | return child; |
370 | } | |
371 | ||
352e512c | 372 | extern int dst_discard(struct sk_buff *skb); |
7f95e188 | 373 | extern void *dst_alloc(struct dst_ops *ops, struct net_device *dev, |
5c1e6aa3 | 374 | int initial_ref, int initial_obsolete, int flags); |
7f95e188 EZ |
375 | extern void __dst_free(struct dst_entry *dst); |
376 | extern struct dst_entry *dst_destroy(struct dst_entry *dst); | |
1da177e4 | 377 | |
7f95e188 | 378 | static inline void dst_free(struct dst_entry *dst) |
1da177e4 LT |
379 | { |
380 | if (dst->obsolete > 1) | |
381 | return; | |
382 | if (!atomic_read(&dst->__refcnt)) { | |
383 | dst = dst_destroy(dst); | |
384 | if (!dst) | |
385 | return; | |
386 | } | |
387 | __dst_free(dst); | |
388 | } | |
389 | ||
390 | static inline void dst_rcu_free(struct rcu_head *head) | |
391 | { | |
392 | struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); | |
393 | dst_free(dst); | |
394 | } | |
395 | ||
396 | static inline void dst_confirm(struct dst_entry *dst) | |
397 | { | |
69cce1d1 | 398 | if (dst) { |
f2c31e32 ED |
399 | struct neighbour *n; |
400 | ||
401 | rcu_read_lock(); | |
27217455 | 402 | n = dst_get_neighbour_noref(dst); |
69cce1d1 | 403 | neigh_confirm(n); |
f2c31e32 | 404 | rcu_read_unlock(); |
69cce1d1 | 405 | } |
1da177e4 LT |
406 | } |
407 | ||
d3aaeb38 DM |
408 | static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr) |
409 | { | |
410 | return dst->ops->neigh_lookup(dst, daddr); | |
411 | } | |
412 | ||
1da177e4 LT |
413 | static inline void dst_link_failure(struct sk_buff *skb) |
414 | { | |
adf30907 | 415 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
416 | if (dst && dst->ops && dst->ops->link_failure) |
417 | dst->ops->link_failure(skb); | |
418 | } | |
419 | ||
420 | static inline void dst_set_expires(struct dst_entry *dst, int timeout) | |
421 | { | |
422 | unsigned long expires = jiffies + timeout; | |
423 | ||
424 | if (expires == 0) | |
425 | expires = 1; | |
426 | ||
427 | if (dst->expires == 0 || time_before(expires, dst->expires)) | |
428 | dst->expires = expires; | |
429 | } | |
430 | ||
431 | /* Output packet to network from transport. */ | |
432 | static inline int dst_output(struct sk_buff *skb) | |
433 | { | |
adf30907 | 434 | return skb_dst(skb)->output(skb); |
1da177e4 LT |
435 | } |
436 | ||
437 | /* Input packet from network to transport. */ | |
438 | static inline int dst_input(struct sk_buff *skb) | |
439 | { | |
adf30907 | 440 | return skb_dst(skb)->input(skb); |
1da177e4 LT |
441 | } |
442 | ||
443 | static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie) | |
444 | { | |
445 | if (dst->obsolete) | |
446 | dst = dst->ops->check(dst, cookie); | |
447 | return dst; | |
448 | } | |
449 | ||
450 | extern void dst_init(void); | |
451 | ||
815f4e57 HX |
452 | /* Flags for xfrm_lookup flags argument. */ |
453 | enum { | |
80c0bc9e | 454 | XFRM_LOOKUP_ICMP = 1 << 0, |
815f4e57 HX |
455 | }; |
456 | ||
1da177e4 LT |
457 | struct flowi; |
458 | #ifndef CONFIG_XFRM | |
452edd59 DM |
459 | static inline struct dst_entry *xfrm_lookup(struct net *net, |
460 | struct dst_entry *dst_orig, | |
461 | const struct flowi *fl, struct sock *sk, | |
462 | int flags) | |
1da177e4 | 463 | { |
452edd59 | 464 | return dst_orig; |
1da177e4 LT |
465 | } |
466 | #else | |
452edd59 DM |
467 | extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig, |
468 | const struct flowi *fl, struct sock *sk, | |
469 | int flags); | |
1da177e4 | 470 | #endif |
1da177e4 LT |
471 | |
472 | #endif /* _NET_DST_H */ |