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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
11#include <net/dst_ops.h>
12#include <linux/netdevice.h>
13#include <linux/rtnetlink.h>
14#include <linux/rcupdate.h>
15#include <linux/bug.h>
16#include <linux/jiffies.h>
17#include <net/neighbour.h>
18#include <asm/processor.h>
19
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
31struct sk_buff;
32
33struct dst_entry {
34 struct rcu_head rcu_head;
35 struct dst_entry *child;
36 struct net_device *dev;
37 struct dst_ops *ops;
38 unsigned long _metrics;
39 unsigned long expires;
40 struct dst_entry *path;
41 struct dst_entry *from;
42#ifdef CONFIG_XFRM
43 struct xfrm_state *xfrm;
44#else
45 void *__pad1;
46#endif
47 int (*input)(struct sk_buff *);
48 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
49
50 unsigned short flags;
51#define DST_HOST 0x0001
52#define DST_NOXFRM 0x0002
53#define DST_NOPOLICY 0x0004
54#define DST_NOHASH 0x0008
55#define DST_NOCACHE 0x0010
56#define DST_NOCOUNT 0x0020
57#define DST_FAKE_RTABLE 0x0040
58#define DST_XFRM_TUNNEL 0x0080
59#define DST_XFRM_QUEUE 0x0100
60#define DST_METADATA 0x0200
61
62 unsigned short pending_confirm;
63
64 short error;
65
66 /* A non-zero value of dst->obsolete forces by-hand validation
67 * of the route entry. Positive values are set by the generic
68 * dst layer to indicate that the entry has been forcefully
69 * destroyed.
70 *
71 * Negative values are used by the implementation layer code to
72 * force invocation of the dst_ops->check() method.
73 */
74 short obsolete;
75#define DST_OBSOLETE_NONE 0
76#define DST_OBSOLETE_DEAD 2
77#define DST_OBSOLETE_FORCE_CHK -1
78#define DST_OBSOLETE_KILL -2
79 unsigned short header_len; /* more space at head required */
80 unsigned short trailer_len; /* space to reserve at tail */
81#ifdef CONFIG_IP_ROUTE_CLASSID
82 __u32 tclassid;
83#else
84 __u32 __pad2;
85#endif
86
87#ifdef CONFIG_64BIT
88 struct lwtunnel_state *lwtstate;
89 /*
90 * Align __refcnt to a 64 bytes alignment
91 * (L1_CACHE_SIZE would be too much)
92 */
93 long __pad_to_align_refcnt[1];
94#endif
95 /*
96 * __refcnt wants to be on a different cache line from
97 * input/output/ops or performance tanks badly
98 */
99 atomic_t __refcnt; /* client references */
100 int __use;
101 unsigned long lastuse;
102#ifndef CONFIG_64BIT
103 struct lwtunnel_state *lwtstate;
104#endif
105 union {
106 struct dst_entry *next;
107 struct rtable __rcu *rt_next;
108 struct rt6_info *rt6_next;
109 struct dn_route __rcu *dn_next;
110 };
111};
112
113u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
114extern const u32 dst_default_metrics[];
115
116#define DST_METRICS_READ_ONLY 0x1UL
117#define DST_METRICS_FLAGS 0x3UL
118#define __DST_METRICS_PTR(Y) \
119 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
120#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
121
122static inline bool dst_metrics_read_only(const struct dst_entry *dst)
123{
124 return dst->_metrics & DST_METRICS_READ_ONLY;
125}
126
127void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
128
129static 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
136static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
137{
138 unsigned long p = dst->_metrics;
139
140 BUG_ON(!p);
141
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 */
150static 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
158static 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
169static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
170{
171 return DST_METRICS_PTR(dst);
172}
173
174static inline u32
175dst_metric_raw(const struct dst_entry *dst, const int metric)
176{
177 u32 *p = DST_METRICS_PTR(dst);
178
179 return p[metric-1];
180}
181
182static inline u32
183dst_metric(const struct dst_entry *dst, const int metric)
184{
185 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
186 metric == RTAX_ADVMSS ||
187 metric == RTAX_MTU);
188 return dst_metric_raw(dst, metric);
189}
190
191static inline u32
192dst_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
202static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
203{
204 u32 *p = dst_metrics_write_ptr(dst);
205
206 if (p)
207 p[metric-1] = val;
208}
209
210/* Kernel-internal feature bits that are unallocated in user space. */
211#define DST_FEATURE_ECN_CA (1 << 31)
212
213#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
214#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)
215
216static inline u32
217dst_feature(const struct dst_entry *dst, u32 feature)
218{
219 return dst_metric(dst, RTAX_FEATURES) & feature;
220}
221
222static inline u32 dst_mtu(const struct dst_entry *dst)
223{
224 return dst->ops->mtu(dst);
225}
226
227/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
228static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
229{
230 return msecs_to_jiffies(dst_metric(dst, metric));
231}
232
233static inline u32
234dst_allfrag(const struct dst_entry *dst)
235{
236 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
237 return ret;
238}
239
240static inline int
241dst_metric_locked(const struct dst_entry *dst, int metric)
242{
243 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
244}
245
246static inline void dst_hold(struct dst_entry *dst)
247{
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);
253 atomic_inc(&dst->__refcnt);
254}
255
256static 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
263static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
264{
265 dst->__use++;
266 dst->lastuse = time;
267}
268
269static inline struct dst_entry *dst_clone(struct dst_entry *dst)
270{
271 if (dst)
272 atomic_inc(&dst->__refcnt);
273 return dst;
274}
275
276void dst_release(struct dst_entry *dst);
277
278static 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 */
290static inline void skb_dst_drop(struct sk_buff *skb)
291{
292 if (skb->_skb_refdst) {
293 refdst_drop(skb->_skb_refdst);
294 skb->_skb_refdst = 0UL;
295 }
296}
297
298static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
299{
300 nskb->_skb_refdst = refdst;
301 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
302 dst_clone(skb_dst(nskb));
303}
304
305static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
306{
307 __skb_dst_copy(nskb, oskb->_skb_refdst);
308}
309
310/**
311 * skb_dst_force - makes sure skb dst is refcounted
312 * @skb: buffer
313 *
314 * If dst is not yet refcounted, let's do it
315 */
316static inline void skb_dst_force(struct sk_buff *skb)
317{
318 if (skb_dst_is_noref(skb)) {
319 WARN_ON(!rcu_read_lock_held());
320 skb->_skb_refdst &= ~SKB_DST_NOREF;
321 dst_clone(skb_dst(skb));
322 }
323}
324
325/**
326 * dst_hold_safe - Take a reference on a dst if possible
327 * @dst: pointer to dst entry
328 *
329 * This helper returns false if it could not safely
330 * take a reference on a dst.
331 */
332static inline bool dst_hold_safe(struct dst_entry *dst)
333{
334 if (dst->flags & DST_NOCACHE)
335 return atomic_inc_not_zero(&dst->__refcnt);
336 dst_hold(dst);
337 return true;
338}
339
340/**
341 * skb_dst_force_safe - makes sure skb dst is refcounted
342 * @skb: buffer
343 *
344 * If dst is not yet refcounted and not destroyed, grab a ref on it.
345 */
346static inline void skb_dst_force_safe(struct sk_buff *skb)
347{
348 if (skb_dst_is_noref(skb)) {
349 struct dst_entry *dst = skb_dst(skb);
350
351 if (!dst_hold_safe(dst))
352 dst = NULL;
353
354 skb->_skb_refdst = (unsigned long)dst;
355 }
356}
357
358
359/**
360 * __skb_tunnel_rx - prepare skb for rx reinsert
361 * @skb: buffer
362 * @dev: tunnel device
363 * @net: netns for packet i/o
364 *
365 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
366 * so make some cleanups. (no accounting done)
367 */
368static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
369 struct net *net)
370{
371 skb->dev = dev;
372
373 /*
374 * Clear hash so that we can recalulate the hash for the
375 * encapsulated packet, unless we have already determine the hash
376 * over the L4 4-tuple.
377 */
378 skb_clear_hash_if_not_l4(skb);
379 skb_set_queue_mapping(skb, 0);
380 skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
381}
382
383/**
384 * skb_tunnel_rx - prepare skb for rx reinsert
385 * @skb: buffer
386 * @dev: tunnel device
387 *
388 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
389 * so make some cleanups, and perform accounting.
390 * Note: this accounting is not SMP safe.
391 */
392static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
393 struct net *net)
394{
395 /* TODO : stats should be SMP safe */
396 dev->stats.rx_packets++;
397 dev->stats.rx_bytes += skb->len;
398 __skb_tunnel_rx(skb, dev, net);
399}
400
401static inline u32 dst_tclassid(const struct sk_buff *skb)
402{
403#ifdef CONFIG_IP_ROUTE_CLASSID
404 const struct dst_entry *dst;
405
406 dst = skb_dst(skb);
407 if (dst)
408 return dst->tclassid;
409#endif
410 return 0;
411}
412
413int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
414static inline int dst_discard(struct sk_buff *skb)
415{
416 return dst_discard_out(&init_net, skb->sk, skb);
417}
418void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
419 int initial_obsolete, unsigned short flags);
420void dst_init(struct dst_entry *dst, struct dst_ops *ops,
421 struct net_device *dev, int initial_ref, int initial_obsolete,
422 unsigned short flags);
423void __dst_free(struct dst_entry *dst);
424struct dst_entry *dst_destroy(struct dst_entry *dst);
425
426static inline void dst_free(struct dst_entry *dst)
427{
428 if (dst->obsolete > 0)
429 return;
430 if (!atomic_read(&dst->__refcnt)) {
431 dst = dst_destroy(dst);
432 if (!dst)
433 return;
434 }
435 __dst_free(dst);
436}
437
438static inline void dst_rcu_free(struct rcu_head *head)
439{
440 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
441 dst_free(dst);
442}
443
444static inline void dst_confirm(struct dst_entry *dst)
445{
446 dst->pending_confirm = 1;
447}
448
449static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
450 struct sk_buff *skb)
451{
452 const struct hh_cache *hh;
453
454 if (dst->pending_confirm) {
455 unsigned long now = jiffies;
456
457 dst->pending_confirm = 0;
458 /* avoid dirtying neighbour */
459 if (n->confirmed != now)
460 n->confirmed = now;
461 }
462
463 hh = &n->hh;
464 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
465 return neigh_hh_output(hh, skb);
466 else
467 return n->output(n, skb);
468}
469
470static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
471{
472 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
473 return IS_ERR(n) ? NULL : n;
474}
475
476static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
477 struct sk_buff *skb)
478{
479 struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
480 return IS_ERR(n) ? NULL : n;
481}
482
483static inline void dst_link_failure(struct sk_buff *skb)
484{
485 struct dst_entry *dst = skb_dst(skb);
486 if (dst && dst->ops && dst->ops->link_failure)
487 dst->ops->link_failure(skb);
488}
489
490static inline void dst_set_expires(struct dst_entry *dst, int timeout)
491{
492 unsigned long expires = jiffies + timeout;
493
494 if (expires == 0)
495 expires = 1;
496
497 if (dst->expires == 0 || time_before(expires, dst->expires))
498 dst->expires = expires;
499}
500
501/* Output packet to network from transport. */
502static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
503{
504 return skb_dst(skb)->output(net, sk, skb);
505}
506
507/* Input packet from network to transport. */
508static inline int dst_input(struct sk_buff *skb)
509{
510 return skb_dst(skb)->input(skb);
511}
512
513static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
514{
515 if (dst->obsolete)
516 dst = dst->ops->check(dst, cookie);
517 return dst;
518}
519
520void dst_subsys_init(void);
521
522/* Flags for xfrm_lookup flags argument. */
523enum {
524 XFRM_LOOKUP_ICMP = 1 << 0,
525 XFRM_LOOKUP_QUEUE = 1 << 1,
526 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
527};
528
529struct flowi;
530#ifndef CONFIG_XFRM
531static inline struct dst_entry *xfrm_lookup(struct net *net,
532 struct dst_entry *dst_orig,
533 const struct flowi *fl,
534 const struct sock *sk,
535 int flags)
536{
537 return dst_orig;
538}
539
540static inline struct dst_entry *xfrm_lookup_route(struct net *net,
541 struct dst_entry *dst_orig,
542 const struct flowi *fl,
543 const struct sock *sk,
544 int flags)
545{
546 return dst_orig;
547}
548
549static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
550{
551 return NULL;
552}
553
554#else
555struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
556 const struct flowi *fl, const struct sock *sk,
557 int flags);
558
559struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
560 const struct flowi *fl, const struct sock *sk,
561 int flags);
562
563/* skb attached with this dst needs transformation if dst->xfrm is valid */
564static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
565{
566 return dst->xfrm;
567}
568#endif
569
570#endif /* _NET_DST_H */
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
11#include <net/dst_ops.h>
12#include <linux/netdevice.h>
13#include <linux/rtnetlink.h>
14#include <linux/rcupdate.h>
15#include <linux/bug.h>
16#include <linux/jiffies.h>
17#include <net/neighbour.h>
18#include <asm/processor.h>
19
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
31struct sk_buff;
32
33struct dst_entry {
34 struct rcu_head rcu_head;
35 struct dst_entry *child;
36 struct net_device *dev;
37 struct dst_ops *ops;
38 unsigned long _metrics;
39 unsigned long expires;
40 struct dst_entry *path;
41 struct dst_entry *from;
42#ifdef CONFIG_XFRM
43 struct xfrm_state *xfrm;
44#else
45 void *__pad1;
46#endif
47 int (*input)(struct sk_buff *);
48 int (*output)(struct sock *sk, struct sk_buff *skb);
49
50 unsigned short flags;
51#define DST_HOST 0x0001
52#define DST_NOXFRM 0x0002
53#define DST_NOPOLICY 0x0004
54#define DST_NOHASH 0x0008
55#define DST_NOCACHE 0x0010
56#define DST_NOCOUNT 0x0020
57#define DST_FAKE_RTABLE 0x0040
58#define DST_XFRM_TUNNEL 0x0080
59#define DST_XFRM_QUEUE 0x0100
60
61 unsigned short pending_confirm;
62
63 short error;
64
65 /* A non-zero value of dst->obsolete forces by-hand validation
66 * of the route entry. Positive values are set by the generic
67 * dst layer to indicate that the entry has been forcefully
68 * destroyed.
69 *
70 * Negative values are used by the implementation layer code to
71 * force invocation of the dst_ops->check() method.
72 */
73 short obsolete;
74#define DST_OBSOLETE_NONE 0
75#define DST_OBSOLETE_DEAD 2
76#define DST_OBSOLETE_FORCE_CHK -1
77#define DST_OBSOLETE_KILL -2
78 unsigned short header_len; /* more space at head required */
79 unsigned short trailer_len; /* space to reserve at tail */
80#ifdef CONFIG_IP_ROUTE_CLASSID
81 __u32 tclassid;
82#else
83 __u32 __pad2;
84#endif
85
86 /*
87 * Align __refcnt to a 64 bytes alignment
88 * (L1_CACHE_SIZE would be too much)
89 */
90#ifdef CONFIG_64BIT
91 long __pad_to_align_refcnt[2];
92#endif
93 /*
94 * __refcnt wants to be on a different cache line from
95 * input/output/ops or performance tanks badly
96 */
97 atomic_t __refcnt; /* client references */
98 int __use;
99 unsigned long lastuse;
100 union {
101 struct dst_entry *next;
102 struct rtable __rcu *rt_next;
103 struct rt6_info *rt6_next;
104 struct dn_route __rcu *dn_next;
105 };
106};
107
108u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
109extern const u32 dst_default_metrics[];
110
111#define DST_METRICS_READ_ONLY 0x1UL
112#define DST_METRICS_FORCE_OVERWRITE 0x2UL
113#define DST_METRICS_FLAGS 0x3UL
114#define __DST_METRICS_PTR(Y) \
115 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
116#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
117
118static inline bool dst_metrics_read_only(const struct dst_entry *dst)
119{
120 return dst->_metrics & DST_METRICS_READ_ONLY;
121}
122
123static inline void dst_metrics_set_force_overwrite(struct dst_entry *dst)
124{
125 dst->_metrics |= DST_METRICS_FORCE_OVERWRITE;
126}
127
128void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
129
130static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
131{
132 unsigned long val = dst->_metrics;
133 if (!(val & DST_METRICS_READ_ONLY))
134 __dst_destroy_metrics_generic(dst, val);
135}
136
137static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
138{
139 unsigned long p = dst->_metrics;
140
141 BUG_ON(!p);
142
143 if (p & DST_METRICS_READ_ONLY)
144 return dst->ops->cow_metrics(dst, p);
145 return __DST_METRICS_PTR(p);
146}
147
148/* This may only be invoked before the entry has reached global
149 * visibility.
150 */
151static inline void dst_init_metrics(struct dst_entry *dst,
152 const u32 *src_metrics,
153 bool read_only)
154{
155 dst->_metrics = ((unsigned long) src_metrics) |
156 (read_only ? DST_METRICS_READ_ONLY : 0);
157}
158
159static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
160{
161 u32 *dst_metrics = dst_metrics_write_ptr(dest);
162
163 if (dst_metrics) {
164 u32 *src_metrics = DST_METRICS_PTR(src);
165
166 memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
167 }
168}
169
170static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
171{
172 return DST_METRICS_PTR(dst);
173}
174
175static inline u32
176dst_metric_raw(const struct dst_entry *dst, const int metric)
177{
178 u32 *p = DST_METRICS_PTR(dst);
179
180 return p[metric-1];
181}
182
183static inline u32
184dst_metric(const struct dst_entry *dst, const int metric)
185{
186 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
187 metric == RTAX_ADVMSS ||
188 metric == RTAX_MTU);
189 return dst_metric_raw(dst, metric);
190}
191
192static inline u32
193dst_metric_advmss(const struct dst_entry *dst)
194{
195 u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
196
197 if (!advmss)
198 advmss = dst->ops->default_advmss(dst);
199
200 return advmss;
201}
202
203static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
204{
205 u32 *p = dst_metrics_write_ptr(dst);
206
207 if (p)
208 p[metric-1] = val;
209}
210
211static inline u32
212dst_feature(const struct dst_entry *dst, u32 feature)
213{
214 return dst_metric(dst, RTAX_FEATURES) & feature;
215}
216
217static inline u32 dst_mtu(const struct dst_entry *dst)
218{
219 return dst->ops->mtu(dst);
220}
221
222/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
223static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
224{
225 return msecs_to_jiffies(dst_metric(dst, metric));
226}
227
228static inline u32
229dst_allfrag(const struct dst_entry *dst)
230{
231 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
232 return ret;
233}
234
235static inline int
236dst_metric_locked(const struct dst_entry *dst, int metric)
237{
238 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
239}
240
241static inline void dst_hold(struct dst_entry *dst)
242{
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);
248 atomic_inc(&dst->__refcnt);
249}
250
251static 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
258static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
259{
260 dst->__use++;
261 dst->lastuse = time;
262}
263
264static inline struct dst_entry *dst_clone(struct dst_entry *dst)
265{
266 if (dst)
267 atomic_inc(&dst->__refcnt);
268 return dst;
269}
270
271void dst_release(struct dst_entry *dst);
272
273static inline void refdst_drop(unsigned long refdst)
274{
275 if (!(refdst & SKB_DST_NOREF))
276 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
277}
278
279/**
280 * skb_dst_drop - drops skb dst
281 * @skb: buffer
282 *
283 * Drops dst reference count if a reference was taken.
284 */
285static inline void skb_dst_drop(struct sk_buff *skb)
286{
287 if (skb->_skb_refdst) {
288 refdst_drop(skb->_skb_refdst);
289 skb->_skb_refdst = 0UL;
290 }
291}
292
293static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
294{
295 nskb->_skb_refdst = oskb->_skb_refdst;
296 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
297 dst_clone(skb_dst(nskb));
298}
299
300/**
301 * skb_dst_force - makes sure skb dst is refcounted
302 * @skb: buffer
303 *
304 * If dst is not yet refcounted, let's do it
305 */
306static inline void skb_dst_force(struct sk_buff *skb)
307{
308 if (skb_dst_is_noref(skb)) {
309 WARN_ON(!rcu_read_lock_held());
310 skb->_skb_refdst &= ~SKB_DST_NOREF;
311 dst_clone(skb_dst(skb));
312 }
313}
314
315
316/**
317 * __skb_tunnel_rx - prepare skb for rx reinsert
318 * @skb: buffer
319 * @dev: tunnel device
320 * @net: netns for packet i/o
321 *
322 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
323 * so make some cleanups. (no accounting done)
324 */
325static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
326 struct net *net)
327{
328 skb->dev = dev;
329
330 /*
331 * Clear hash so that we can recalulate the hash for the
332 * encapsulated packet, unless we have already determine the hash
333 * over the L4 4-tuple.
334 */
335 skb_clear_hash_if_not_l4(skb);
336 skb_set_queue_mapping(skb, 0);
337 skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
338}
339
340/**
341 * skb_tunnel_rx - prepare skb for rx reinsert
342 * @skb: buffer
343 * @dev: tunnel device
344 *
345 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
346 * so make some cleanups, and perform accounting.
347 * Note: this accounting is not SMP safe.
348 */
349static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
350 struct net *net)
351{
352 /* TODO : stats should be SMP safe */
353 dev->stats.rx_packets++;
354 dev->stats.rx_bytes += skb->len;
355 __skb_tunnel_rx(skb, dev, net);
356}
357
358/* Children define the path of the packet through the
359 * Linux networking. Thus, destinations are stackable.
360 */
361
362static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
363{
364 struct dst_entry *child = dst_clone(skb_dst(skb)->child);
365
366 skb_dst_drop(skb);
367 return child;
368}
369
370int dst_discard_sk(struct sock *sk, struct sk_buff *skb);
371static inline int dst_discard(struct sk_buff *skb)
372{
373 return dst_discard_sk(skb->sk, skb);
374}
375void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
376 int initial_obsolete, unsigned short flags);
377void __dst_free(struct dst_entry *dst);
378struct dst_entry *dst_destroy(struct dst_entry *dst);
379
380static inline void dst_free(struct dst_entry *dst)
381{
382 if (dst->obsolete > 0)
383 return;
384 if (!atomic_read(&dst->__refcnt)) {
385 dst = dst_destroy(dst);
386 if (!dst)
387 return;
388 }
389 __dst_free(dst);
390}
391
392static inline void dst_rcu_free(struct rcu_head *head)
393{
394 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
395 dst_free(dst);
396}
397
398static inline void dst_confirm(struct dst_entry *dst)
399{
400 dst->pending_confirm = 1;
401}
402
403static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
404 struct sk_buff *skb)
405{
406 const struct hh_cache *hh;
407
408 if (dst->pending_confirm) {
409 unsigned long now = jiffies;
410
411 dst->pending_confirm = 0;
412 /* avoid dirtying neighbour */
413 if (n->confirmed != now)
414 n->confirmed = now;
415 }
416
417 hh = &n->hh;
418 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
419 return neigh_hh_output(hh, skb);
420 else
421 return n->output(n, skb);
422}
423
424static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
425{
426 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
427 return IS_ERR(n) ? NULL : n;
428}
429
430static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
431 struct sk_buff *skb)
432{
433 struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
434 return IS_ERR(n) ? NULL : n;
435}
436
437static inline void dst_link_failure(struct sk_buff *skb)
438{
439 struct dst_entry *dst = skb_dst(skb);
440 if (dst && dst->ops && dst->ops->link_failure)
441 dst->ops->link_failure(skb);
442}
443
444static inline void dst_set_expires(struct dst_entry *dst, int timeout)
445{
446 unsigned long expires = jiffies + timeout;
447
448 if (expires == 0)
449 expires = 1;
450
451 if (dst->expires == 0 || time_before(expires, dst->expires))
452 dst->expires = expires;
453}
454
455/* Output packet to network from transport. */
456static inline int dst_output_sk(struct sock *sk, struct sk_buff *skb)
457{
458 return skb_dst(skb)->output(sk, skb);
459}
460static inline int dst_output(struct sk_buff *skb)
461{
462 return dst_output_sk(skb->sk, skb);
463}
464
465/* Input packet from network to transport. */
466static inline int dst_input(struct sk_buff *skb)
467{
468 return skb_dst(skb)->input(skb);
469}
470
471static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
472{
473 if (dst->obsolete)
474 dst = dst->ops->check(dst, cookie);
475 return dst;
476}
477
478void dst_init(void);
479
480/* Flags for xfrm_lookup flags argument. */
481enum {
482 XFRM_LOOKUP_ICMP = 1 << 0,
483};
484
485struct flowi;
486#ifndef CONFIG_XFRM
487static inline struct dst_entry *xfrm_lookup(struct net *net,
488 struct dst_entry *dst_orig,
489 const struct flowi *fl, struct sock *sk,
490 int flags)
491{
492 return dst_orig;
493}
494
495static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
496{
497 return NULL;
498}
499
500#else
501struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
502 const struct flowi *fl, struct sock *sk,
503 int flags);
504
505/* skb attached with this dst needs transformation if dst->xfrm is valid */
506static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
507{
508 return dst->xfrm;
509}
510#endif
511
512#endif /* _NET_DST_H */