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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 */
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 union {
40 unsigned long expires;
41 /* point to where the dst_entry copied from */
42 struct dst_entry *from;
43 };
44 struct dst_entry *path;
45 struct neighbour __rcu *_neighbour;
46#ifdef CONFIG_XFRM
47 struct xfrm_state *xfrm;
48#else
49 void *__pad1;
50#endif
51 int (*input)(struct sk_buff*);
52 int (*output)(struct sk_buff*);
53
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
61#define DST_NOPEER 0x0040
62#define DST_FAKE_RTABLE 0x0080
63#define DST_XFRM_TUNNEL 0x0100
64
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 */
69#ifdef CONFIG_IP_ROUTE_CLASSID
70 __u32 tclassid;
71#else
72 __u32 __pad2;
73#endif
74
75 /*
76 * Align __refcnt to a 64 bytes alignment
77 * (L1_CACHE_SIZE would be too much)
78 */
79#ifdef CONFIG_64BIT
80 long __pad_to_align_refcnt[2];
81#endif
82 /*
83 * __refcnt wants to be on a different cache line from
84 * input/output/ops or performance tanks badly
85 */
86 atomic_t __refcnt; /* client references */
87 int __use;
88 unsigned long lastuse;
89 union {
90 struct dst_entry *next;
91 struct rtable __rcu *rt_next;
92 struct rt6_info *rt6_next;
93 struct dn_route __rcu *dn_next;
94 };
95};
96
97static inline struct neighbour *dst_get_neighbour_noref(struct dst_entry *dst)
98{
99 return rcu_dereference(dst->_neighbour);
100}
101
102static inline struct neighbour *dst_get_neighbour_noref_raw(struct dst_entry *dst)
103{
104 return rcu_dereference_raw(dst->_neighbour);
105}
106
107static inline void dst_set_neighbour(struct dst_entry *dst, struct neighbour *neigh)
108{
109 rcu_assign_pointer(dst->_neighbour, neigh);
110}
111
112extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
113extern const u32 dst_default_metrics[RTAX_MAX];
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
120static inline bool dst_metrics_read_only(const struct dst_entry *dst)
121{
122 return dst->_metrics & DST_METRICS_READ_ONLY;
123}
124
125extern void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
126
127static 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
134static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
135{
136 unsigned long p = dst->_metrics;
137
138 BUG_ON(!p);
139
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 */
148static 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
156static 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
167static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
168{
169 return DST_METRICS_PTR(dst);
170}
171
172static inline u32
173dst_metric_raw(const struct dst_entry *dst, const int metric)
174{
175 u32 *p = DST_METRICS_PTR(dst);
176
177 return p[metric-1];
178}
179
180static inline u32
181dst_metric(const struct dst_entry *dst, const int metric)
182{
183 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
184 metric == RTAX_ADVMSS ||
185 metric == RTAX_MTU);
186 return dst_metric_raw(dst, metric);
187}
188
189static inline u32
190dst_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
200static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
201{
202 u32 *p = dst_metrics_write_ptr(dst);
203
204 if (p)
205 p[metric-1] = val;
206}
207
208static inline u32
209dst_feature(const struct dst_entry *dst, u32 feature)
210{
211 return dst_metric(dst, RTAX_FEATURES) & feature;
212}
213
214static inline u32 dst_mtu(const struct dst_entry *dst)
215{
216 return dst->ops->mtu(dst);
217}
218
219/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
220static 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
225static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
226 unsigned long rtt)
227{
228 dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
229}
230
231static inline u32
232dst_allfrag(const struct dst_entry *dst)
233{
234 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
235 return ret;
236}
237
238static inline int
239dst_metric_locked(const struct dst_entry *dst, int metric)
240{
241 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
242}
243
244static inline void dst_hold(struct dst_entry * dst)
245{
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);
251 atomic_inc(&dst->__refcnt);
252}
253
254static 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
261static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
262{
263 dst->__use++;
264 dst->lastuse = time;
265}
266
267static inline
268struct dst_entry * dst_clone(struct dst_entry * dst)
269{
270 if (dst)
271 atomic_inc(&dst->__refcnt);
272 return dst;
273}
274
275extern void dst_release(struct dst_entry *dst);
276
277static inline void refdst_drop(unsigned long refdst)
278{
279 if (!(refdst & SKB_DST_NOREF))
280 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
281}
282
283/**
284 * skb_dst_drop - drops skb dst
285 * @skb: buffer
286 *
287 * Drops dst reference count if a reference was taken.
288 */
289static inline void skb_dst_drop(struct sk_buff *skb)
290{
291 if (skb->_skb_refdst) {
292 refdst_drop(skb->_skb_refdst);
293 skb->_skb_refdst = 0UL;
294 }
295}
296
297static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
298{
299 nskb->_skb_refdst = oskb->_skb_refdst;
300 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
301 dst_clone(skb_dst(nskb));
302}
303
304/**
305 * skb_dst_force - makes sure skb dst is refcounted
306 * @skb: buffer
307 *
308 * If dst is not yet refcounted, let's do it
309 */
310static inline void skb_dst_force(struct sk_buff *skb)
311{
312 if (skb_dst_is_noref(skb)) {
313 WARN_ON(!rcu_read_lock_held());
314 skb->_skb_refdst &= ~SKB_DST_NOREF;
315 dst_clone(skb_dst(skb));
316 }
317}
318
319
320/**
321 * __skb_tunnel_rx - prepare skb for rx reinsert
322 * @skb: buffer
323 * @dev: tunnel device
324 *
325 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
326 * so make some cleanups. (no accounting done)
327 */
328static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
329{
330 skb->dev = dev;
331
332 /*
333 * Clear rxhash so that we can recalulate the hash for the
334 * encapsulated packet, unless we have already determine the hash
335 * over the L4 4-tuple.
336 */
337 if (!skb->l4_rxhash)
338 skb->rxhash = 0;
339 skb_set_queue_mapping(skb, 0);
340 skb_dst_drop(skb);
341 nf_reset(skb);
342}
343
344/**
345 * skb_tunnel_rx - prepare skb for rx reinsert
346 * @skb: buffer
347 * @dev: tunnel device
348 *
349 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
350 * so make some cleanups, and perform accounting.
351 * Note: this accounting is not SMP safe.
352 */
353static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
354{
355 /* TODO : stats should be SMP safe */
356 dev->stats.rx_packets++;
357 dev->stats.rx_bytes += skb->len;
358 __skb_tunnel_rx(skb, dev);
359}
360
361/* Children define the path of the packet through the
362 * Linux networking. Thus, destinations are stackable.
363 */
364
365static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
366{
367 struct dst_entry *child = dst_clone(skb_dst(skb)->child);
368
369 skb_dst_drop(skb);
370 return child;
371}
372
373extern int dst_discard(struct sk_buff *skb);
374extern void *dst_alloc(struct dst_ops * ops, struct net_device *dev,
375 int initial_ref, int initial_obsolete, int flags);
376extern void __dst_free(struct dst_entry * dst);
377extern struct dst_entry *dst_destroy(struct dst_entry * dst);
378
379static inline void dst_free(struct dst_entry * dst)
380{
381 if (dst->obsolete > 1)
382 return;
383 if (!atomic_read(&dst->__refcnt)) {
384 dst = dst_destroy(dst);
385 if (!dst)
386 return;
387 }
388 __dst_free(dst);
389}
390
391static inline void dst_rcu_free(struct rcu_head *head)
392{
393 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
394 dst_free(dst);
395}
396
397static inline void dst_confirm(struct dst_entry *dst)
398{
399 if (dst) {
400 struct neighbour *n;
401
402 rcu_read_lock();
403 n = dst_get_neighbour_noref(dst);
404 neigh_confirm(n);
405 rcu_read_unlock();
406 }
407}
408
409static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
410{
411 return dst->ops->neigh_lookup(dst, daddr);
412}
413
414static inline void dst_link_failure(struct sk_buff *skb)
415{
416 struct dst_entry *dst = skb_dst(skb);
417 if (dst && dst->ops && dst->ops->link_failure)
418 dst->ops->link_failure(skb);
419}
420
421static inline void dst_set_expires(struct dst_entry *dst, int timeout)
422{
423 unsigned long expires = jiffies + timeout;
424
425 if (expires == 0)
426 expires = 1;
427
428 if (dst->expires == 0 || time_before(expires, dst->expires))
429 dst->expires = expires;
430}
431
432/* Output packet to network from transport. */
433static inline int dst_output(struct sk_buff *skb)
434{
435 return skb_dst(skb)->output(skb);
436}
437
438/* Input packet from network to transport. */
439static inline int dst_input(struct sk_buff *skb)
440{
441 return skb_dst(skb)->input(skb);
442}
443
444static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
445{
446 if (dst->obsolete)
447 dst = dst->ops->check(dst, cookie);
448 return dst;
449}
450
451extern void dst_init(void);
452
453/* Flags for xfrm_lookup flags argument. */
454enum {
455 XFRM_LOOKUP_ICMP = 1 << 0,
456};
457
458struct flowi;
459#ifndef CONFIG_XFRM
460static inline struct dst_entry *xfrm_lookup(struct net *net,
461 struct dst_entry *dst_orig,
462 const struct flowi *fl, struct sock *sk,
463 int flags)
464{
465 return dst_orig;
466}
467#else
468extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
469 const struct flowi *fl, struct sock *sk,
470 int flags);
471#endif
472
473#endif /* _NET_DST_H */