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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; | |
c4d54110 HX |
43 | short error; |
44 | short obsolete; | |
1da177e4 LT |
45 | int flags; |
46 | #define DST_HOST 1 | |
47 | #define DST_NOXFRM 2 | |
48 | #define DST_NOPOLICY 4 | |
49 | #define DST_NOHASH 8 | |
1da177e4 LT |
50 | unsigned long expires; |
51 | ||
52 | unsigned short header_len; /* more space at head required */ | |
53 | unsigned short trailer_len; /* space to reserve at tail */ | |
54 | ||
69a73829 | 55 | unsigned int rate_tokens; |
f1dd9c37 | 56 | unsigned long rate_last; /* rate limiting for ICMP */ |
69a73829 | 57 | |
f1dd9c37 | 58 | struct dst_entry *path; |
1da177e4 | 59 | |
1da177e4 LT |
60 | struct neighbour *neighbour; |
61 | struct hh_cache *hh; | |
def8b4fa | 62 | #ifdef CONFIG_XFRM |
1da177e4 | 63 | struct xfrm_state *xfrm; |
5635c10d ED |
64 | #else |
65 | void *__pad1; | |
def8b4fa | 66 | #endif |
1da177e4 LT |
67 | int (*input)(struct sk_buff*); |
68 | int (*output)(struct sk_buff*); | |
69 | ||
1da177e4 | 70 | struct dst_ops *ops; |
f1dd9c37 ZY |
71 | |
72 | u32 metrics[RTAX_MAX]; | |
73 | ||
74 | #ifdef CONFIG_NET_CLS_ROUTE | |
75 | __u32 tclassid; | |
5635c10d ED |
76 | #else |
77 | __u32 __pad2; | |
f1dd9c37 ZY |
78 | #endif |
79 | ||
5635c10d ED |
80 | |
81 | /* | |
82 | * Align __refcnt to a 64 bytes alignment | |
83 | * (L1_CACHE_SIZE would be too much) | |
84 | */ | |
85 | #ifdef CONFIG_64BIT | |
86 | long __pad_to_align_refcnt[2]; | |
87 | #else | |
88 | long __pad_to_align_refcnt[1]; | |
89 | #endif | |
f1dd9c37 ZY |
90 | /* |
91 | * __refcnt wants to be on a different cache line from | |
92 | * input/output/ops or performance tanks badly | |
93 | */ | |
1e19e02c ED |
94 | atomic_t __refcnt; /* client references */ |
95 | int __use; | |
f1dd9c37 | 96 | unsigned long lastuse; |
1e19e02c ED |
97 | union { |
98 | struct dst_entry *next; | |
99 | struct rtable *rt_next; | |
100 | struct rt6_info *rt6_next; | |
101 | struct dn_route *dn_next; | |
102 | }; | |
1da177e4 LT |
103 | }; |
104 | ||
1da177e4 LT |
105 | #ifdef __KERNEL__ |
106 | ||
107 | static inline u32 | |
108 | dst_metric(const struct dst_entry *dst, int metric) | |
109 | { | |
110 | return dst->metrics[metric-1]; | |
111 | } | |
112 | ||
0c3adfb8 GBY |
113 | static inline u32 |
114 | dst_feature(const struct dst_entry *dst, u32 feature) | |
115 | { | |
116 | return dst_metric(dst, RTAX_FEATURES) & feature; | |
117 | } | |
118 | ||
1da177e4 LT |
119 | static inline u32 dst_mtu(const struct dst_entry *dst) |
120 | { | |
121 | u32 mtu = dst_metric(dst, RTAX_MTU); | |
122 | /* | |
123 | * Alexey put it here, so ask him about it :) | |
124 | */ | |
125 | barrier(); | |
126 | return mtu; | |
127 | } | |
128 | ||
c1e20f7c SH |
129 | /* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */ |
130 | static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric) | |
131 | { | |
132 | return msecs_to_jiffies(dst_metric(dst, metric)); | |
133 | } | |
134 | ||
135 | static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric, | |
136 | unsigned long rtt) | |
137 | { | |
138 | dst->metrics[metric-1] = jiffies_to_msecs(rtt); | |
139 | } | |
140 | ||
1da177e4 LT |
141 | static inline u32 |
142 | dst_allfrag(const struct dst_entry *dst) | |
143 | { | |
0c3adfb8 | 144 | int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG); |
1da177e4 LT |
145 | /* Yes, _exactly_. This is paranoia. */ |
146 | barrier(); | |
147 | return ret; | |
148 | } | |
149 | ||
150 | static inline int | |
151 | dst_metric_locked(struct dst_entry *dst, int metric) | |
152 | { | |
153 | return dst_metric(dst, RTAX_LOCK) & (1<<metric); | |
154 | } | |
155 | ||
156 | static inline void dst_hold(struct dst_entry * dst) | |
157 | { | |
5635c10d ED |
158 | /* |
159 | * If your kernel compilation stops here, please check | |
160 | * __pad_to_align_refcnt declaration in struct dst_entry | |
161 | */ | |
162 | BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63); | |
1da177e4 LT |
163 | atomic_inc(&dst->__refcnt); |
164 | } | |
165 | ||
03f49f34 PE |
166 | static inline void dst_use(struct dst_entry *dst, unsigned long time) |
167 | { | |
168 | dst_hold(dst); | |
169 | dst->__use++; | |
170 | dst->lastuse = time; | |
171 | } | |
172 | ||
1da177e4 LT |
173 | static inline |
174 | struct dst_entry * dst_clone(struct dst_entry * dst) | |
175 | { | |
176 | if (dst) | |
177 | atomic_inc(&dst->__refcnt); | |
178 | return dst; | |
179 | } | |
180 | ||
8d330868 | 181 | extern void dst_release(struct dst_entry *dst); |
adf30907 ED |
182 | static inline void skb_dst_drop(struct sk_buff *skb) |
183 | { | |
184 | if (skb->_skb_dst) | |
185 | dst_release(skb_dst(skb)); | |
186 | skb->_skb_dst = 0UL; | |
187 | } | |
1da177e4 LT |
188 | |
189 | /* Children define the path of the packet through the | |
190 | * Linux networking. Thus, destinations are stackable. | |
191 | */ | |
192 | ||
193 | static inline struct dst_entry *dst_pop(struct dst_entry *dst) | |
194 | { | |
195 | struct dst_entry *child = dst_clone(dst->child); | |
196 | ||
197 | dst_release(dst); | |
198 | return child; | |
199 | } | |
200 | ||
352e512c | 201 | extern int dst_discard(struct sk_buff *skb); |
1da177e4 LT |
202 | extern void * dst_alloc(struct dst_ops * ops); |
203 | extern void __dst_free(struct dst_entry * dst); | |
204 | extern struct dst_entry *dst_destroy(struct dst_entry * dst); | |
205 | ||
206 | static inline void dst_free(struct dst_entry * dst) | |
207 | { | |
208 | if (dst->obsolete > 1) | |
209 | return; | |
210 | if (!atomic_read(&dst->__refcnt)) { | |
211 | dst = dst_destroy(dst); | |
212 | if (!dst) | |
213 | return; | |
214 | } | |
215 | __dst_free(dst); | |
216 | } | |
217 | ||
218 | static inline void dst_rcu_free(struct rcu_head *head) | |
219 | { | |
220 | struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); | |
221 | dst_free(dst); | |
222 | } | |
223 | ||
224 | static inline void dst_confirm(struct dst_entry *dst) | |
225 | { | |
226 | if (dst) | |
227 | neigh_confirm(dst->neighbour); | |
228 | } | |
229 | ||
ea94ff3b KK |
230 | static inline void dst_negative_advice(struct dst_entry **dst_p, |
231 | struct sock *sk) | |
1da177e4 LT |
232 | { |
233 | struct dst_entry * dst = *dst_p; | |
ea94ff3b | 234 | if (dst && dst->ops->negative_advice) { |
1da177e4 | 235 | *dst_p = dst->ops->negative_advice(dst); |
ea94ff3b KK |
236 | |
237 | if (dst != *dst_p) { | |
238 | extern void sk_reset_txq(struct sock *sk); | |
239 | ||
240 | sk_reset_txq(sk); | |
241 | } | |
242 | } | |
1da177e4 LT |
243 | } |
244 | ||
245 | static inline void dst_link_failure(struct sk_buff *skb) | |
246 | { | |
adf30907 | 247 | struct dst_entry *dst = skb_dst(skb); |
1da177e4 LT |
248 | if (dst && dst->ops && dst->ops->link_failure) |
249 | dst->ops->link_failure(skb); | |
250 | } | |
251 | ||
252 | static inline void dst_set_expires(struct dst_entry *dst, int timeout) | |
253 | { | |
254 | unsigned long expires = jiffies + timeout; | |
255 | ||
256 | if (expires == 0) | |
257 | expires = 1; | |
258 | ||
259 | if (dst->expires == 0 || time_before(expires, dst->expires)) | |
260 | dst->expires = expires; | |
261 | } | |
262 | ||
263 | /* Output packet to network from transport. */ | |
264 | static inline int dst_output(struct sk_buff *skb) | |
265 | { | |
adf30907 | 266 | return skb_dst(skb)->output(skb); |
1da177e4 LT |
267 | } |
268 | ||
269 | /* Input packet from network to transport. */ | |
270 | static inline int dst_input(struct sk_buff *skb) | |
271 | { | |
adf30907 | 272 | return skb_dst(skb)->input(skb); |
1da177e4 LT |
273 | } |
274 | ||
275 | static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie) | |
276 | { | |
277 | if (dst->obsolete) | |
278 | dst = dst->ops->check(dst, cookie); | |
279 | return dst; | |
280 | } | |
281 | ||
282 | extern void dst_init(void); | |
283 | ||
815f4e57 HX |
284 | /* Flags for xfrm_lookup flags argument. */ |
285 | enum { | |
286 | XFRM_LOOKUP_WAIT = 1 << 0, | |
8b7817f3 | 287 | XFRM_LOOKUP_ICMP = 1 << 1, |
815f4e57 HX |
288 | }; |
289 | ||
1da177e4 LT |
290 | struct flowi; |
291 | #ifndef CONFIG_XFRM | |
52479b62 AD |
292 | static inline int xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
293 | struct flowi *fl, struct sock *sk, int flags) | |
1da177e4 LT |
294 | { |
295 | return 0; | |
296 | } | |
52479b62 AD |
297 | static inline int __xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
298 | struct flowi *fl, struct sock *sk, int flags) | |
14e50e57 DM |
299 | { |
300 | return 0; | |
301 | } | |
1da177e4 | 302 | #else |
52479b62 AD |
303 | extern int xfrm_lookup(struct net *net, struct dst_entry **dst_p, |
304 | struct flowi *fl, struct sock *sk, int flags); | |
305 | extern int __xfrm_lookup(struct net *net, struct dst_entry **dst_p, | |
306 | struct flowi *fl, struct sock *sk, int flags); | |
1da177e4 LT |
307 | #endif |
308 | #endif | |
309 | ||
310 | #endif /* _NET_DST_H */ |