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> | |
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; |
1da177e4 LT |
40 | struct neighbour *neighbour; |
41 | struct hh_cache *hh; | |
def8b4fa | 42 | #ifdef CONFIG_XFRM |
1da177e4 | 43 | struct xfrm_state *xfrm; |
5635c10d ED |
44 | #else |
45 | void *__pad1; | |
def8b4fa | 46 | #endif |
1da177e4 LT |
47 | int (*input)(struct sk_buff*); |
48 | int (*output)(struct sk_buff*); | |
49 | ||
62fa8a84 DM |
50 | short error; |
51 | short obsolete; | |
52 | unsigned short header_len; /* more space at head required */ | |
53 | unsigned short trailer_len; /* space to reserve at tail */ | |
c7066f70 | 54 | #ifdef CONFIG_IP_ROUTE_CLASSID |
f1dd9c37 | 55 | __u32 tclassid; |
5635c10d ED |
56 | #else |
57 | __u32 __pad2; | |
f1dd9c37 ZY |
58 | #endif |
59 | ||
5635c10d ED |
60 | /* |
61 | * Align __refcnt to a 64 bytes alignment | |
62 | * (L1_CACHE_SIZE would be too much) | |
63 | */ | |
64 | #ifdef CONFIG_64BIT | |
5635c10d ED |
65 | long __pad_to_align_refcnt[1]; |
66 | #endif | |
f1dd9c37 ZY |
67 | /* |
68 | * __refcnt wants to be on a different cache line from | |
69 | * input/output/ops or performance tanks badly | |
70 | */ | |
1e19e02c ED |
71 | atomic_t __refcnt; /* client references */ |
72 | int __use; | |
f1dd9c37 | 73 | unsigned long lastuse; |
62fa8a84 DM |
74 | int flags; |
75 | #define DST_HOST 0x0001 | |
76 | #define DST_NOXFRM 0x0002 | |
77 | #define DST_NOPOLICY 0x0004 | |
78 | #define DST_NOHASH 0x0008 | |
79 | #define DST_NOCACHE 0x0010 | |
1e19e02c | 80 | union { |
fc766e4c ED |
81 | struct dst_entry *next; |
82 | struct rtable __rcu *rt_next; | |
83 | struct rt6_info *rt6_next; | |
84 | struct dn_route __rcu *dn_next; | |
1e19e02c | 85 | }; |
1da177e4 LT |
86 | }; |
87 | ||
62fa8a84 | 88 | extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old); |
725d1e1b | 89 | extern const u32 dst_default_metrics[RTAX_MAX]; |
62fa8a84 DM |
90 | |
91 | #define DST_METRICS_READ_ONLY 0x1UL | |
92 | #define __DST_METRICS_PTR(Y) \ | |
93 | ((u32 *)((Y) & ~DST_METRICS_READ_ONLY)) | |
94 | #define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics) | |
95 | ||
96 | static inline bool dst_metrics_read_only(const struct dst_entry *dst) | |
97 | { | |
98 | return dst->_metrics & DST_METRICS_READ_ONLY; | |
99 | } | |
100 | ||
101 | extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old); | |
102 | ||
103 | static inline void dst_destroy_metrics_generic(struct dst_entry *dst) | |
104 | { | |
105 | unsigned long val = dst->_metrics; | |
106 | if (!(val & DST_METRICS_READ_ONLY)) | |
107 | __dst_destroy_metrics_generic(dst, val); | |
108 | } | |
109 | ||
110 | static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst) | |
111 | { | |
112 | unsigned long p = dst->_metrics; | |
113 | ||
114 | if (p & DST_METRICS_READ_ONLY) | |
115 | return dst->ops->cow_metrics(dst, p); | |
116 | return __DST_METRICS_PTR(p); | |
117 | } | |
118 | ||
119 | /* This may only be invoked before the entry has reached global | |
120 | * visibility. | |
121 | */ | |
122 | static inline void dst_init_metrics(struct dst_entry *dst, | |
123 | const u32 *src_metrics, | |
124 | bool read_only) | |
125 | { | |
126 | dst->_metrics = ((unsigned long) src_metrics) | | |
127 | (read_only ? DST_METRICS_READ_ONLY : 0); | |
128 | } | |
129 | ||
130 | static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src) | |
131 | { | |
132 | u32 *dst_metrics = dst_metrics_write_ptr(dest); | |
133 | ||
134 | if (dst_metrics) { | |
135 | u32 *src_metrics = DST_METRICS_PTR(src); | |
136 | ||
137 | memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32)); | |
138 | } | |
139 | } | |
140 | ||
141 | static inline u32 *dst_metrics_ptr(struct dst_entry *dst) | |
142 | { | |
143 | return DST_METRICS_PTR(dst); | |
144 | } | |
145 | ||
1da177e4 | 146 | static inline u32 |
5170ae82 | 147 | dst_metric_raw(const struct dst_entry *dst, const int metric) |
1da177e4 | 148 | { |
62fa8a84 DM |
149 | u32 *p = DST_METRICS_PTR(dst); |
150 | ||
151 | return p[metric-1]; | |
defb3519 DM |
152 | } |
153 | ||
5170ae82 DM |
154 | static inline u32 |
155 | dst_metric(const struct dst_entry *dst, const int metric) | |
156 | { | |
0dbaee3b | 157 | WARN_ON_ONCE(metric == RTAX_HOPLIMIT || |
d33e4553 DM |
158 | metric == RTAX_ADVMSS || |
159 | metric == RTAX_MTU); | |
5170ae82 DM |
160 | return dst_metric_raw(dst, metric); |
161 | } | |
162 | ||
0dbaee3b DM |
163 | static inline u32 |
164 | dst_metric_advmss(const struct dst_entry *dst) | |
165 | { | |
166 | u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS); | |
167 | ||
168 | if (!advmss) | |
169 | advmss = dst->ops->default_advmss(dst); | |
170 | ||
171 | return advmss; | |
172 | } | |
173 | ||
defb3519 DM |
174 | static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val) |
175 | { | |
62fa8a84 | 176 | u32 *p = dst_metrics_write_ptr(dst); |
defb3519 | 177 | |
62fa8a84 DM |
178 | if (p) |
179 | p[metric-1] = val; | |
1da177e4 LT |
180 | } |
181 | ||
0c3adfb8 GBY |
182 | static inline u32 |
183 | dst_feature(const struct dst_entry *dst, u32 feature) | |
184 | { | |
bb5b7c11 | 185 | return dst_metric(dst, RTAX_FEATURES) & feature; |
0c3adfb8 GBY |
186 | } |
187 | ||
1da177e4 LT |
188 | static inline u32 dst_mtu(const struct dst_entry *dst) |
189 | { | |
d33e4553 DM |
190 | u32 mtu = dst_metric_raw(dst, RTAX_MTU); |
191 | ||
192 | if (!mtu) | |
193 | mtu = dst->ops->default_mtu(dst); | |
194 | ||
1da177e4 LT |
195 | return mtu; |
196 | } | |
197 | ||
c1e20f7c SH |
198 | /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */ |
199 | static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric) | |
200 | { | |
201 | return msecs_to_jiffies(dst_metric(dst, metric)); | |
202 | } | |
203 | ||
204 | static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric, | |
205 | unsigned long rtt) | |
206 | { | |
defb3519 | 207 | dst_metric_set(dst, metric, jiffies_to_msecs(rtt)); |
c1e20f7c SH |
208 | } |
209 | ||
1da177e4 LT |
210 | static inline u32 |
211 | dst_allfrag(const struct dst_entry *dst) | |
212 | { | |
0c3adfb8 | 213 | int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG); |
1da177e4 LT |
214 | return ret; |
215 | } | |
216 | ||
217 | static inline int | |
d33e4553 | 218 | dst_metric_locked(const struct dst_entry *dst, int metric) |
1da177e4 LT |
219 | { |
220 | return dst_metric(dst, RTAX_LOCK) & (1<<metric); | |
221 | } | |
222 | ||
223 | static inline void dst_hold(struct dst_entry * dst) | |
224 | { | |
5635c10d ED |
225 | /* |
226 | * If your kernel compilation stops here, please check | |
227 | * __pad_to_align_refcnt declaration in struct dst_entry | |
228 | */ | |
229 | BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); | |
1da177e4 LT |
230 | atomic_inc(&dst->__refcnt); |
231 | } | |
232 | ||
03f49f34 PE |
233 | static inline void dst_use(struct dst_entry *dst, unsigned long time) |
234 | { | |
235 | dst_hold(dst); | |
236 | dst->__use++; | |
237 | dst->lastuse = time; | |
238 | } | |
239 | ||
7fee226a ED |
240 | static inline void dst_use_noref(struct dst_entry *dst, unsigned long time) |
241 | { | |
242 | dst->__use++; | |
243 | dst->lastuse = time; | |
244 | } | |
245 | ||
1da177e4 LT |
246 | static inline |
247 | struct dst_entry * dst_clone(struct dst_entry * dst) | |
248 | { | |
249 | if (dst) | |
250 | atomic_inc(&dst->__refcnt); | |
251 | return dst; | |
252 | } | |
253 | ||
8d330868 | 254 | extern void dst_release(struct dst_entry *dst); |
7fee226a ED |
255 | |
256 | static inline void refdst_drop(unsigned long refdst) | |
257 | { | |
258 | if (!(refdst & SKB_DST_NOREF)) | |
259 | dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK)); | |
260 | } | |
261 | ||
262 | /** | |
263 | * skb_dst_drop - drops skb dst | |
264 | * @skb: buffer | |
265 | * | |
266 | * Drops dst reference count if a reference was taken. | |
267 | */ | |
adf30907 ED |
268 | static inline void skb_dst_drop(struct sk_buff *skb) |
269 | { | |
7fee226a ED |
270 | if (skb->_skb_refdst) { |
271 | refdst_drop(skb->_skb_refdst); | |
272 | skb->_skb_refdst = 0UL; | |
273 | } | |
274 | } | |
275 | ||
276 | static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb) | |
277 | { | |
278 | nskb->_skb_refdst = oskb->_skb_refdst; | |
279 | if (!(nskb->_skb_refdst & SKB_DST_NOREF)) | |
280 | dst_clone(skb_dst(nskb)); | |
281 | } | |
282 | ||
283 | /** | |
284 | * skb_dst_force - makes sure skb dst is refcounted | |
285 | * @skb: buffer | |
286 | * | |
287 | * If dst is not yet refcounted, let's do it | |
288 | */ | |
289 | static inline void skb_dst_force(struct sk_buff *skb) | |
290 | { | |
291 | if (skb_dst_is_noref(skb)) { | |
292 | WARN_ON(!rcu_read_lock_held()); | |
293 | skb->_skb_refdst &= ~SKB_DST_NOREF; | |
294 | dst_clone(skb_dst(skb)); | |
295 | } | |
adf30907 | 296 | } |
1da177e4 | 297 | |
d19d56dd | 298 | |
290b895e ED |
299 | /** |
300 | * __skb_tunnel_rx - prepare skb for rx reinsert | |
301 | * @skb: buffer | |
302 | * @dev: tunnel device | |
303 | * | |
304 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
305 | * so make some cleanups. (no accounting done) | |
306 | */ | |
307 | static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
308 | { | |
309 | skb->dev = dev; | |
310 | skb->rxhash = 0; | |
311 | skb_set_queue_mapping(skb, 0); | |
312 | skb_dst_drop(skb); | |
313 | nf_reset(skb); | |
314 | } | |
315 | ||
d19d56dd ED |
316 | /** |
317 | * skb_tunnel_rx - prepare skb for rx reinsert | |
318 | * @skb: buffer | |
319 | * @dev: tunnel device | |
320 | * | |
321 | * After decapsulation, packet is going to re-enter (netif_rx()) our stack, | |
322 | * so make some cleanups, and perform accounting. | |
290b895e | 323 | * Note: this accounting is not SMP safe. |
d19d56dd ED |
324 | */ |
325 | static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev) | |
326 | { | |
d19d56dd ED |
327 | /* TODO : stats should be SMP safe */ |
328 | dev->stats.rx_packets++; | |
329 | dev->stats.rx_bytes += skb->len; | |
290b895e | 330 | __skb_tunnel_rx(skb, dev); |
d19d56dd ED |
331 | } |
332 | ||
1da177e4 LT |
333 | /* Children define the path of the packet through the |
334 | * Linux networking. Thus, destinations are stackable. | |
335 | */ | |
336 | ||
8764ab2c | 337 | static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb) |
1da177e4 | 338 | { |
e433430a | 339 | struct dst_entry *child = dst_clone(skb_dst(skb)->child); |
1da177e4 | 340 | |
8764ab2c | 341 | skb_dst_drop(skb); |
1da177e4 LT |
342 | return child; |
343 | } | |
344 | ||
352e512c | 345 | extern int dst_discard(struct sk_buff *skb); |
5c1e6aa3 DM |
346 | extern void *dst_alloc(struct dst_ops * ops, struct net_device *dev, |
347 | int initial_ref, int initial_obsolete, int flags); | |
1da177e4 LT |
348 | extern void __dst_free(struct dst_entry * dst); |
349 | extern struct dst_entry *dst_destroy(struct dst_entry * dst); | |
350 | ||
351 | static inline void dst_free(struct dst_entry * dst) | |
352 | { | |
353 | if (dst->obsolete > 1) | |
354 | return; | |
355 | if (!atomic_read(&dst->__refcnt)) { | |
356 | dst = dst_destroy(dst); | |
357 | if (!dst) | |
358 | return; | |
359 | } | |
360 | __dst_free(dst); | |
361 | } | |
362 | ||
363 | static inline void dst_rcu_free(struct rcu_head *head) | |
364 | { | |
365 | struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); | |
366 | dst_free(dst); | |
367 | } | |
368 | ||
369 | static inline void dst_confirm(struct dst_entry *dst) | |
370 | { | |
371 | if (dst) | |
372 | neigh_confirm(dst->neighbour); | |
373 | } | |
374 | ||
1da177e4 LT |
375 | static inline void dst_link_failure(struct sk_buff *skb) |
376 | { | |
adf30907 | 377 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
378 | if (dst && dst->ops && dst->ops->link_failure) |
379 | dst->ops->link_failure(skb); | |
380 | } | |
381 | ||
382 | static inline void dst_set_expires(struct dst_entry *dst, int timeout) | |
383 | { | |
384 | unsigned long expires = jiffies + timeout; | |
385 | ||
386 | if (expires == 0) | |
387 | expires = 1; | |
388 | ||
389 | if (dst->expires == 0 || time_before(expires, dst->expires)) | |
390 | dst->expires = expires; | |
391 | } | |
392 | ||
393 | /* Output packet to network from transport. */ | |
394 | static inline int dst_output(struct sk_buff *skb) | |
395 | { | |
adf30907 | 396 | return skb_dst(skb)->output(skb); |
1da177e4 LT |
397 | } |
398 | ||
399 | /* Input packet from network to transport. */ | |
400 | static inline int dst_input(struct sk_buff *skb) | |
401 | { | |
adf30907 | 402 | return skb_dst(skb)->input(skb); |
1da177e4 LT |
403 | } |
404 | ||
405 | static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie) | |
406 | { | |
407 | if (dst->obsolete) | |
408 | dst = dst->ops->check(dst, cookie); | |
409 | return dst; | |
410 | } | |
411 | ||
412 | extern void dst_init(void); | |
413 | ||
815f4e57 HX |
414 | /* Flags for xfrm_lookup flags argument. */ |
415 | enum { | |
80c0bc9e | 416 | XFRM_LOOKUP_ICMP = 1 << 0, |
815f4e57 HX |
417 | }; |
418 | ||
1da177e4 LT |
419 | struct flowi; |
420 | #ifndef CONFIG_XFRM | |
452edd59 DM |
421 | static inline struct dst_entry *xfrm_lookup(struct net *net, |
422 | struct dst_entry *dst_orig, | |
423 | const struct flowi *fl, struct sock *sk, | |
424 | int flags) | |
1da177e4 | 425 | { |
452edd59 | 426 | return dst_orig; |
1da177e4 LT |
427 | } |
428 | #else | |
452edd59 DM |
429 | extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig, |
430 | const struct flowi *fl, struct sock *sk, | |
431 | int flags); | |
1da177e4 | 432 | #endif |
1da177e4 LT |
433 | |
434 | #endif /* _NET_DST_H */ |