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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#include <linux/indirect_call_wrapper.h>
22
23struct sk_buff;
24
25struct dst_entry {
26 struct net_device *dev;
27 struct dst_ops *ops;
28 unsigned long _metrics;
29 unsigned long expires;
30#ifdef CONFIG_XFRM
31 struct xfrm_state *xfrm;
32#else
33 void *__pad1;
34#endif
35 int (*input)(struct sk_buff *);
36 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
37
38 unsigned short flags;
39#define DST_NOXFRM 0x0002
40#define DST_NOPOLICY 0x0004
41#define DST_NOCOUNT 0x0008
42#define DST_FAKE_RTABLE 0x0010
43#define DST_XFRM_TUNNEL 0x0020
44#define DST_XFRM_QUEUE 0x0040
45#define DST_METADATA 0x0080
46
47 /* A non-zero value of dst->obsolete forces by-hand validation
48 * of the route entry. Positive values are set by the generic
49 * dst layer to indicate that the entry has been forcefully
50 * destroyed.
51 *
52 * Negative values are used by the implementation layer code to
53 * force invocation of the dst_ops->check() method.
54 */
55 short obsolete;
56#define DST_OBSOLETE_NONE 0
57#define DST_OBSOLETE_DEAD 2
58#define DST_OBSOLETE_FORCE_CHK -1
59#define DST_OBSOLETE_KILL -2
60 unsigned short header_len; /* more space at head required */
61 unsigned short trailer_len; /* space to reserve at tail */
62
63 /*
64 * __refcnt wants to be on a different cache line from
65 * input/output/ops or performance tanks badly
66 */
67#ifdef CONFIG_64BIT
68 atomic_t __refcnt; /* 64-bit offset 64 */
69#endif
70 int __use;
71 unsigned long lastuse;
72 struct lwtunnel_state *lwtstate;
73 struct rcu_head rcu_head;
74 short error;
75 short __pad;
76 __u32 tclassid;
77#ifndef CONFIG_64BIT
78 atomic_t __refcnt; /* 32-bit offset 64 */
79#endif
80};
81
82struct dst_metrics {
83 u32 metrics[RTAX_MAX];
84 refcount_t refcnt;
85} __aligned(4); /* Low pointer bits contain DST_METRICS_FLAGS */
86extern const struct dst_metrics dst_default_metrics;
87
88u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
89
90#define DST_METRICS_READ_ONLY 0x1UL
91#define DST_METRICS_REFCOUNTED 0x2UL
92#define DST_METRICS_FLAGS 0x3UL
93#define __DST_METRICS_PTR(Y) \
94 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
95#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
96
97static inline bool dst_metrics_read_only(const struct dst_entry *dst)
98{
99 return dst->_metrics & DST_METRICS_READ_ONLY;
100}
101
102void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
103
104static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
105{
106 unsigned long val = dst->_metrics;
107 if (!(val & DST_METRICS_READ_ONLY))
108 __dst_destroy_metrics_generic(dst, val);
109}
110
111static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
112{
113 unsigned long p = dst->_metrics;
114
115 BUG_ON(!p);
116
117 if (p & DST_METRICS_READ_ONLY)
118 return dst->ops->cow_metrics(dst, p);
119 return __DST_METRICS_PTR(p);
120}
121
122/* This may only be invoked before the entry has reached global
123 * visibility.
124 */
125static inline void dst_init_metrics(struct dst_entry *dst,
126 const u32 *src_metrics,
127 bool read_only)
128{
129 dst->_metrics = ((unsigned long) src_metrics) |
130 (read_only ? DST_METRICS_READ_ONLY : 0);
131}
132
133static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
134{
135 u32 *dst_metrics = dst_metrics_write_ptr(dest);
136
137 if (dst_metrics) {
138 u32 *src_metrics = DST_METRICS_PTR(src);
139
140 memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
141 }
142}
143
144static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
145{
146 return DST_METRICS_PTR(dst);
147}
148
149static inline u32
150dst_metric_raw(const struct dst_entry *dst, const int metric)
151{
152 u32 *p = DST_METRICS_PTR(dst);
153
154 return p[metric-1];
155}
156
157static inline u32
158dst_metric(const struct dst_entry *dst, const int metric)
159{
160 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
161 metric == RTAX_ADVMSS ||
162 metric == RTAX_MTU);
163 return dst_metric_raw(dst, metric);
164}
165
166static inline u32
167dst_metric_advmss(const struct dst_entry *dst)
168{
169 u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
170
171 if (!advmss)
172 advmss = dst->ops->default_advmss(dst);
173
174 return advmss;
175}
176
177static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
178{
179 u32 *p = dst_metrics_write_ptr(dst);
180
181 if (p)
182 p[metric-1] = val;
183}
184
185/* Kernel-internal feature bits that are unallocated in user space. */
186#define DST_FEATURE_ECN_CA (1U << 31)
187
188#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
189#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)
190
191static inline u32
192dst_feature(const struct dst_entry *dst, u32 feature)
193{
194 return dst_metric(dst, RTAX_FEATURES) & feature;
195}
196
197INDIRECT_CALLABLE_DECLARE(unsigned int ip6_mtu(const struct dst_entry *));
198INDIRECT_CALLABLE_DECLARE(unsigned int ipv4_mtu(const struct dst_entry *));
199static inline u32 dst_mtu(const struct dst_entry *dst)
200{
201 return INDIRECT_CALL_INET(dst->ops->mtu, ip6_mtu, ipv4_mtu, dst);
202}
203
204/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
205static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
206{
207 return msecs_to_jiffies(dst_metric(dst, metric));
208}
209
210static inline u32
211dst_allfrag(const struct dst_entry *dst)
212{
213 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
214 return ret;
215}
216
217static inline int
218dst_metric_locked(const struct dst_entry *dst, int metric)
219{
220 return dst_metric(dst, RTAX_LOCK) & (1 << metric);
221}
222
223static inline void dst_hold(struct dst_entry *dst)
224{
225 /*
226 * If your kernel compilation stops here, please check
227 * the placement of __refcnt in struct dst_entry
228 */
229 BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
230 WARN_ON(atomic_inc_not_zero(&dst->__refcnt) == 0);
231}
232
233static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
234{
235 if (unlikely(time != dst->lastuse)) {
236 dst->__use++;
237 dst->lastuse = time;
238 }
239}
240
241static inline void dst_hold_and_use(struct dst_entry *dst, unsigned long time)
242{
243 dst_hold(dst);
244 dst_use_noref(dst, time);
245}
246
247static inline struct dst_entry *dst_clone(struct dst_entry *dst)
248{
249 if (dst)
250 dst_hold(dst);
251 return dst;
252}
253
254void dst_release(struct dst_entry *dst);
255
256void dst_release_immediate(struct dst_entry *dst);
257
258static inline void refdst_drop(unsigned long refdst)
259{
260 if (!(refdst & SKB_DST_NOREF))
261 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
262}
263
264/**
265 * skb_dst_drop - drops skb dst
266 * @skb: buffer
267 *
268 * Drops dst reference count if a reference was taken.
269 */
270static inline void skb_dst_drop(struct sk_buff *skb)
271{
272 if (skb->_skb_refdst) {
273 refdst_drop(skb->_skb_refdst);
274 skb->_skb_refdst = 0UL;
275 }
276}
277
278static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
279{
280 nskb->_skb_refdst = refdst;
281 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
282 dst_clone(skb_dst(nskb));
283}
284
285static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
286{
287 __skb_dst_copy(nskb, oskb->_skb_refdst);
288}
289
290/**
291 * dst_hold_safe - Take a reference on a dst if possible
292 * @dst: pointer to dst entry
293 *
294 * This helper returns false if it could not safely
295 * take a reference on a dst.
296 */
297static inline bool dst_hold_safe(struct dst_entry *dst)
298{
299 return atomic_inc_not_zero(&dst->__refcnt);
300}
301
302/**
303 * skb_dst_force - makes sure skb dst is refcounted
304 * @skb: buffer
305 *
306 * If dst is not yet refcounted and not destroyed, grab a ref on it.
307 * Returns true if dst is refcounted.
308 */
309static inline bool skb_dst_force(struct sk_buff *skb)
310{
311 if (skb_dst_is_noref(skb)) {
312 struct dst_entry *dst = skb_dst(skb);
313
314 WARN_ON(!rcu_read_lock_held());
315 if (!dst_hold_safe(dst))
316 dst = NULL;
317
318 skb->_skb_refdst = (unsigned long)dst;
319 }
320
321 return skb->_skb_refdst != 0UL;
322}
323
324
325/**
326 * __skb_tunnel_rx - prepare skb for rx reinsert
327 * @skb: buffer
328 * @dev: tunnel device
329 * @net: netns for packet i/o
330 *
331 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
332 * so make some cleanups. (no accounting done)
333 */
334static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
335 struct net *net)
336{
337 skb->dev = dev;
338
339 /*
340 * Clear hash so that we can recalulate the hash for the
341 * encapsulated packet, unless we have already determine the hash
342 * over the L4 4-tuple.
343 */
344 skb_clear_hash_if_not_l4(skb);
345 skb_set_queue_mapping(skb, 0);
346 skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
347}
348
349/**
350 * skb_tunnel_rx - prepare skb for rx reinsert
351 * @skb: buffer
352 * @dev: tunnel device
353 * @net: netns for packet i/o
354 *
355 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
356 * so make some cleanups, and perform accounting.
357 * Note: this accounting is not SMP safe.
358 */
359static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
360 struct net *net)
361{
362 /* TODO : stats should be SMP safe */
363 dev->stats.rx_packets++;
364 dev->stats.rx_bytes += skb->len;
365 __skb_tunnel_rx(skb, dev, net);
366}
367
368static inline u32 dst_tclassid(const struct sk_buff *skb)
369{
370#ifdef CONFIG_IP_ROUTE_CLASSID
371 const struct dst_entry *dst;
372
373 dst = skb_dst(skb);
374 if (dst)
375 return dst->tclassid;
376#endif
377 return 0;
378}
379
380int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
381static inline int dst_discard(struct sk_buff *skb)
382{
383 return dst_discard_out(&init_net, skb->sk, skb);
384}
385void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
386 int initial_obsolete, unsigned short flags);
387void dst_init(struct dst_entry *dst, struct dst_ops *ops,
388 struct net_device *dev, int initial_ref, int initial_obsolete,
389 unsigned short flags);
390struct dst_entry *dst_destroy(struct dst_entry *dst);
391void dst_dev_put(struct dst_entry *dst);
392
393static inline void dst_confirm(struct dst_entry *dst)
394{
395}
396
397static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
398{
399 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
400 return IS_ERR(n) ? NULL : n;
401}
402
403static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
404 struct sk_buff *skb)
405{
406 struct neighbour *n;
407
408 if (WARN_ON_ONCE(!dst->ops->neigh_lookup))
409 return NULL;
410
411 n = dst->ops->neigh_lookup(dst, skb, NULL);
412
413 return IS_ERR(n) ? NULL : n;
414}
415
416static inline void dst_confirm_neigh(const struct dst_entry *dst,
417 const void *daddr)
418{
419 if (dst->ops->confirm_neigh)
420 dst->ops->confirm_neigh(dst, daddr);
421}
422
423static inline void dst_link_failure(struct sk_buff *skb)
424{
425 struct dst_entry *dst = skb_dst(skb);
426 if (dst && dst->ops && dst->ops->link_failure)
427 dst->ops->link_failure(skb);
428}
429
430static inline void dst_set_expires(struct dst_entry *dst, int timeout)
431{
432 unsigned long expires = jiffies + timeout;
433
434 if (expires == 0)
435 expires = 1;
436
437 if (dst->expires == 0 || time_before(expires, dst->expires))
438 dst->expires = expires;
439}
440
441INDIRECT_CALLABLE_DECLARE(int ip6_output(struct net *, struct sock *,
442 struct sk_buff *));
443INDIRECT_CALLABLE_DECLARE(int ip_output(struct net *, struct sock *,
444 struct sk_buff *));
445/* Output packet to network from transport. */
446static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
447{
448 return INDIRECT_CALL_INET(skb_dst(skb)->output,
449 ip6_output, ip_output,
450 net, sk, skb);
451}
452
453INDIRECT_CALLABLE_DECLARE(int ip6_input(struct sk_buff *));
454INDIRECT_CALLABLE_DECLARE(int ip_local_deliver(struct sk_buff *));
455/* Input packet from network to transport. */
456static inline int dst_input(struct sk_buff *skb)
457{
458 return INDIRECT_CALL_INET(skb_dst(skb)->input,
459 ip6_input, ip_local_deliver, skb);
460}
461
462INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
463 u32));
464INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
465 u32));
466static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
467{
468 if (dst->obsolete)
469 dst = INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check,
470 ipv4_dst_check, dst, cookie);
471 return dst;
472}
473
474/* Flags for xfrm_lookup flags argument. */
475enum {
476 XFRM_LOOKUP_ICMP = 1 << 0,
477 XFRM_LOOKUP_QUEUE = 1 << 1,
478 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
479};
480
481struct flowi;
482#ifndef CONFIG_XFRM
483static inline struct dst_entry *xfrm_lookup(struct net *net,
484 struct dst_entry *dst_orig,
485 const struct flowi *fl,
486 const struct sock *sk,
487 int flags)
488{
489 return dst_orig;
490}
491
492static inline struct dst_entry *
493xfrm_lookup_with_ifid(struct net *net, struct dst_entry *dst_orig,
494 const struct flowi *fl, const struct sock *sk,
495 int flags, u32 if_id)
496{
497 return dst_orig;
498}
499
500static inline struct dst_entry *xfrm_lookup_route(struct net *net,
501 struct dst_entry *dst_orig,
502 const struct flowi *fl,
503 const struct sock *sk,
504 int flags)
505{
506 return dst_orig;
507}
508
509static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
510{
511 return NULL;
512}
513
514#else
515struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
516 const struct flowi *fl, const struct sock *sk,
517 int flags);
518
519struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
520 struct dst_entry *dst_orig,
521 const struct flowi *fl,
522 const struct sock *sk, int flags,
523 u32 if_id);
524
525struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
526 const struct flowi *fl, const struct sock *sk,
527 int flags);
528
529/* skb attached with this dst needs transformation if dst->xfrm is valid */
530static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
531{
532 return dst->xfrm;
533}
534#endif
535
536static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
537{
538 struct dst_entry *dst = skb_dst(skb);
539
540 if (dst && dst->ops->update_pmtu)
541 dst->ops->update_pmtu(dst, NULL, skb, mtu, true);
542}
543
544/* update dst pmtu but not do neighbor confirm */
545static inline void skb_dst_update_pmtu_no_confirm(struct sk_buff *skb, u32 mtu)
546{
547 struct dst_entry *dst = skb_dst(skb);
548
549 if (dst && dst->ops->update_pmtu)
550 dst->ops->update_pmtu(dst, NULL, skb, mtu, false);
551}
552
553struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie);
554void dst_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
555 struct sk_buff *skb, u32 mtu, bool confirm_neigh);
556void dst_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
557 struct sk_buff *skb);
558u32 *dst_blackhole_cow_metrics(struct dst_entry *dst, unsigned long old);
559struct neighbour *dst_blackhole_neigh_lookup(const struct dst_entry *dst,
560 struct sk_buff *skb,
561 const void *daddr);
562unsigned int dst_blackhole_mtu(const struct dst_entry *dst);
563
564#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 */