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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 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 */
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * net/dst.h Protocol independent destination cache definitions.
4 *
5 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6 *
7 */
8
9#ifndef _NET_DST_H
10#define _NET_DST_H
11
12#include <net/dst_ops.h>
13#include <linux/netdevice.h>
14#include <linux/rtnetlink.h>
15#include <linux/rcupdate.h>
16#include <linux/bug.h>
17#include <linux/jiffies.h>
18#include <linux/refcount.h>
19#include <net/neighbour.h>
20#include <asm/processor.h>
21
22struct sk_buff;
23
24struct dst_entry {
25 struct net_device *dev;
26 struct dst_ops *ops;
27 unsigned long _metrics;
28 unsigned long expires;
29#ifdef CONFIG_XFRM
30 struct xfrm_state *xfrm;
31#else
32 void *__pad1;
33#endif
34 int (*input)(struct sk_buff *);
35 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
36
37 unsigned short flags;
38#define DST_NOXFRM 0x0002
39#define DST_NOPOLICY 0x0004
40#define DST_NOCOUNT 0x0008
41#define DST_FAKE_RTABLE 0x0010
42#define DST_XFRM_TUNNEL 0x0020
43#define DST_XFRM_QUEUE 0x0040
44#define DST_METADATA 0x0080
45
46 /* A non-zero value of dst->obsolete forces by-hand validation
47 * of the route entry. Positive values are set by the generic
48 * dst layer to indicate that the entry has been forcefully
49 * destroyed.
50 *
51 * Negative values are used by the implementation layer code to
52 * force invocation of the dst_ops->check() method.
53 */
54 short obsolete;
55#define DST_OBSOLETE_NONE 0
56#define DST_OBSOLETE_DEAD 2
57#define DST_OBSOLETE_FORCE_CHK -1
58#define DST_OBSOLETE_KILL -2
59 unsigned short header_len; /* more space at head required */
60 unsigned short trailer_len; /* space to reserve at tail */
61
62 /*
63 * __refcnt wants to be on a different cache line from
64 * input/output/ops or performance tanks badly
65 */
66#ifdef CONFIG_64BIT
67 atomic_t __refcnt; /* 64-bit offset 64 */
68#endif
69 int __use;
70 unsigned long lastuse;
71 struct lwtunnel_state *lwtstate;
72 struct rcu_head rcu_head;
73 short error;
74 short __pad;
75 __u32 tclassid;
76#ifndef CONFIG_64BIT
77 atomic_t __refcnt; /* 32-bit offset 64 */
78#endif
79};
80
81struct dst_metrics {
82 u32 metrics[RTAX_MAX];
83 refcount_t refcnt;
84} __aligned(4); /* Low pointer bits contain DST_METRICS_FLAGS */
85extern const struct dst_metrics dst_default_metrics;
86
87u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
88
89#define DST_METRICS_READ_ONLY 0x1UL
90#define DST_METRICS_REFCOUNTED 0x2UL
91#define DST_METRICS_FLAGS 0x3UL
92#define __DST_METRICS_PTR(Y) \
93 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
94#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
95
96static inline bool dst_metrics_read_only(const struct dst_entry *dst)
97{
98 return dst->_metrics & DST_METRICS_READ_ONLY;
99}
100
101void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
102
103static 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
110static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
111{
112 unsigned long p = dst->_metrics;
113
114 BUG_ON(!p);
115
116 if (p & DST_METRICS_READ_ONLY)
117 return dst->ops->cow_metrics(dst, p);
118 return __DST_METRICS_PTR(p);
119}
120
121/* This may only be invoked before the entry has reached global
122 * visibility.
123 */
124static inline void dst_init_metrics(struct dst_entry *dst,
125 const u32 *src_metrics,
126 bool read_only)
127{
128 dst->_metrics = ((unsigned long) src_metrics) |
129 (read_only ? DST_METRICS_READ_ONLY : 0);
130}
131
132static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
133{
134 u32 *dst_metrics = dst_metrics_write_ptr(dest);
135
136 if (dst_metrics) {
137 u32 *src_metrics = DST_METRICS_PTR(src);
138
139 memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
140 }
141}
142
143static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
144{
145 return DST_METRICS_PTR(dst);
146}
147
148static inline u32
149dst_metric_raw(const struct dst_entry *dst, const int metric)
150{
151 u32 *p = DST_METRICS_PTR(dst);
152
153 return p[metric-1];
154}
155
156static inline u32
157dst_metric(const struct dst_entry *dst, const int metric)
158{
159 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
160 metric == RTAX_ADVMSS ||
161 metric == RTAX_MTU);
162 return dst_metric_raw(dst, metric);
163}
164
165static inline u32
166dst_metric_advmss(const struct dst_entry *dst)
167{
168 u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
169
170 if (!advmss)
171 advmss = dst->ops->default_advmss(dst);
172
173 return advmss;
174}
175
176static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
177{
178 u32 *p = dst_metrics_write_ptr(dst);
179
180 if (p)
181 p[metric-1] = val;
182}
183
184/* Kernel-internal feature bits that are unallocated in user space. */
185#define DST_FEATURE_ECN_CA (1U << 31)
186
187#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
188#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)
189
190static inline u32
191dst_feature(const struct dst_entry *dst, u32 feature)
192{
193 return dst_metric(dst, RTAX_FEATURES) & feature;
194}
195
196static inline u32 dst_mtu(const struct dst_entry *dst)
197{
198 return dst->ops->mtu(dst);
199}
200
201/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
202static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
203{
204 return msecs_to_jiffies(dst_metric(dst, metric));
205}
206
207static inline u32
208dst_allfrag(const struct dst_entry *dst)
209{
210 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
211 return ret;
212}
213
214static inline int
215dst_metric_locked(const struct dst_entry *dst, int metric)
216{
217 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
218}
219
220static inline void dst_hold(struct dst_entry *dst)
221{
222 /*
223 * If your kernel compilation stops here, please check
224 * the placement of __refcnt in struct dst_entry
225 */
226 BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
227 WARN_ON(atomic_inc_not_zero(&dst->__refcnt) == 0);
228}
229
230static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
231{
232 if (unlikely(time != dst->lastuse)) {
233 dst->__use++;
234 dst->lastuse = time;
235 }
236}
237
238static inline void dst_hold_and_use(struct dst_entry *dst, unsigned long time)
239{
240 dst_hold(dst);
241 dst_use_noref(dst, time);
242}
243
244static inline struct dst_entry *dst_clone(struct dst_entry *dst)
245{
246 if (dst)
247 dst_hold(dst);
248 return dst;
249}
250
251void dst_release(struct dst_entry *dst);
252
253void dst_release_immediate(struct dst_entry *dst);
254
255static inline void refdst_drop(unsigned long refdst)
256{
257 if (!(refdst & SKB_DST_NOREF))
258 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
259}
260
261/**
262 * skb_dst_drop - drops skb dst
263 * @skb: buffer
264 *
265 * Drops dst reference count if a reference was taken.
266 */
267static inline void skb_dst_drop(struct sk_buff *skb)
268{
269 if (skb->_skb_refdst) {
270 refdst_drop(skb->_skb_refdst);
271 skb->_skb_refdst = 0UL;
272 }
273}
274
275static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
276{
277 nskb->_skb_refdst = refdst;
278 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
279 dst_clone(skb_dst(nskb));
280}
281
282static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
283{
284 __skb_dst_copy(nskb, oskb->_skb_refdst);
285}
286
287/**
288 * dst_hold_safe - Take a reference on a dst if possible
289 * @dst: pointer to dst entry
290 *
291 * This helper returns false if it could not safely
292 * take a reference on a dst.
293 */
294static inline bool dst_hold_safe(struct dst_entry *dst)
295{
296 return atomic_inc_not_zero(&dst->__refcnt);
297}
298
299/**
300 * skb_dst_force - makes sure skb dst is refcounted
301 * @skb: buffer
302 *
303 * If dst is not yet refcounted and not destroyed, grab a ref on it.
304 * Returns true if dst is refcounted.
305 */
306static inline bool skb_dst_force(struct sk_buff *skb)
307{
308 if (skb_dst_is_noref(skb)) {
309 struct dst_entry *dst = skb_dst(skb);
310
311 WARN_ON(!rcu_read_lock_held());
312 if (!dst_hold_safe(dst))
313 dst = NULL;
314
315 skb->_skb_refdst = (unsigned long)dst;
316 }
317
318 return skb->_skb_refdst != 0UL;
319}
320
321
322/**
323 * __skb_tunnel_rx - prepare skb for rx reinsert
324 * @skb: buffer
325 * @dev: tunnel device
326 * @net: netns for packet i/o
327 *
328 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
329 * so make some cleanups. (no accounting done)
330 */
331static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
332 struct net *net)
333{
334 skb->dev = dev;
335
336 /*
337 * Clear hash so that we can recalulate the hash for the
338 * encapsulated packet, unless we have already determine the hash
339 * over the L4 4-tuple.
340 */
341 skb_clear_hash_if_not_l4(skb);
342 skb_set_queue_mapping(skb, 0);
343 skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
344}
345
346/**
347 * skb_tunnel_rx - prepare skb for rx reinsert
348 * @skb: buffer
349 * @dev: tunnel device
350 * @net: netns for packet i/o
351 *
352 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
353 * so make some cleanups, and perform accounting.
354 * Note: this accounting is not SMP safe.
355 */
356static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
357 struct net *net)
358{
359 /* TODO : stats should be SMP safe */
360 dev->stats.rx_packets++;
361 dev->stats.rx_bytes += skb->len;
362 __skb_tunnel_rx(skb, dev, net);
363}
364
365static inline u32 dst_tclassid(const struct sk_buff *skb)
366{
367#ifdef CONFIG_IP_ROUTE_CLASSID
368 const struct dst_entry *dst;
369
370 dst = skb_dst(skb);
371 if (dst)
372 return dst->tclassid;
373#endif
374 return 0;
375}
376
377int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
378static inline int dst_discard(struct sk_buff *skb)
379{
380 return dst_discard_out(&init_net, skb->sk, skb);
381}
382void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
383 int initial_obsolete, unsigned short flags);
384void dst_init(struct dst_entry *dst, struct dst_ops *ops,
385 struct net_device *dev, int initial_ref, int initial_obsolete,
386 unsigned short flags);
387struct dst_entry *dst_destroy(struct dst_entry *dst);
388void dst_dev_put(struct dst_entry *dst);
389
390static inline void dst_confirm(struct dst_entry *dst)
391{
392}
393
394static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
395{
396 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
397 return IS_ERR(n) ? NULL : n;
398}
399
400static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
401 struct sk_buff *skb)
402{
403 struct neighbour *n = NULL;
404
405 /* The packets from tunnel devices (eg bareudp) may have only
406 * metadata in the dst pointer of skb. Hence a pointer check of
407 * neigh_lookup is needed.
408 */
409 if (dst->ops->neigh_lookup)
410 n = dst->ops->neigh_lookup(dst, skb, NULL);
411
412 return IS_ERR(n) ? NULL : n;
413}
414
415static inline void dst_confirm_neigh(const struct dst_entry *dst,
416 const void *daddr)
417{
418 if (dst->ops->confirm_neigh)
419 dst->ops->confirm_neigh(dst, daddr);
420}
421
422static inline void dst_link_failure(struct sk_buff *skb)
423{
424 struct dst_entry *dst = skb_dst(skb);
425 if (dst && dst->ops && dst->ops->link_failure)
426 dst->ops->link_failure(skb);
427}
428
429static inline void dst_set_expires(struct dst_entry *dst, int timeout)
430{
431 unsigned long expires = jiffies + timeout;
432
433 if (expires == 0)
434 expires = 1;
435
436 if (dst->expires == 0 || time_before(expires, dst->expires))
437 dst->expires = expires;
438}
439
440/* Output packet to network from transport. */
441static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
442{
443 return skb_dst(skb)->output(net, sk, skb);
444}
445
446/* Input packet from network to transport. */
447static inline int dst_input(struct sk_buff *skb)
448{
449 return skb_dst(skb)->input(skb);
450}
451
452static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
453{
454 if (dst->obsolete)
455 dst = dst->ops->check(dst, cookie);
456 return dst;
457}
458
459/* Flags for xfrm_lookup flags argument. */
460enum {
461 XFRM_LOOKUP_ICMP = 1 << 0,
462 XFRM_LOOKUP_QUEUE = 1 << 1,
463 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
464};
465
466struct flowi;
467#ifndef CONFIG_XFRM
468static inline struct dst_entry *xfrm_lookup(struct net *net,
469 struct dst_entry *dst_orig,
470 const struct flowi *fl,
471 const struct sock *sk,
472 int flags)
473{
474 return dst_orig;
475}
476
477static inline struct dst_entry *
478xfrm_lookup_with_ifid(struct net *net, struct dst_entry *dst_orig,
479 const struct flowi *fl, const struct sock *sk,
480 int flags, u32 if_id)
481{
482 return dst_orig;
483}
484
485static inline struct dst_entry *xfrm_lookup_route(struct net *net,
486 struct dst_entry *dst_orig,
487 const struct flowi *fl,
488 const struct sock *sk,
489 int flags)
490{
491 return dst_orig;
492}
493
494static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
495{
496 return NULL;
497}
498
499#else
500struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
501 const struct flowi *fl, const struct sock *sk,
502 int flags);
503
504struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
505 struct dst_entry *dst_orig,
506 const struct flowi *fl,
507 const struct sock *sk, int flags,
508 u32 if_id);
509
510struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
511 const struct flowi *fl, const struct sock *sk,
512 int flags);
513
514/* skb attached with this dst needs transformation if dst->xfrm is valid */
515static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
516{
517 return dst->xfrm;
518}
519#endif
520
521static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
522{
523 struct dst_entry *dst = skb_dst(skb);
524
525 if (dst && dst->ops->update_pmtu)
526 dst->ops->update_pmtu(dst, NULL, skb, mtu, true);
527}
528
529/* update dst pmtu but not do neighbor confirm */
530static inline void skb_dst_update_pmtu_no_confirm(struct sk_buff *skb, u32 mtu)
531{
532 struct dst_entry *dst = skb_dst(skb);
533
534 if (dst && dst->ops->update_pmtu)
535 dst->ops->update_pmtu(dst, NULL, skb, mtu, false);
536}
537
538#endif /* _NET_DST_H */