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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 <linux/rcuref.h>
20#include <net/neighbour.h>
21#include <asm/processor.h>
22#include <linux/indirect_call_wrapper.h>
23
24struct sk_buff;
25
26struct dst_entry {
27 struct net_device *dev;
28 struct dst_ops *ops;
29 unsigned long _metrics;
30 unsigned long expires;
31#ifdef CONFIG_XFRM
32 struct xfrm_state *xfrm;
33#else
34 void *__pad1;
35#endif
36 int (*input)(struct sk_buff *);
37 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
38
39 unsigned short flags;
40#define DST_NOXFRM 0x0002
41#define DST_NOPOLICY 0x0004
42#define DST_NOCOUNT 0x0008
43#define DST_FAKE_RTABLE 0x0010
44#define DST_XFRM_TUNNEL 0x0020
45#define DST_XFRM_QUEUE 0x0040
46#define DST_METADATA 0x0080
47
48 /* A non-zero value of dst->obsolete forces by-hand validation
49 * of the route entry. Positive values are set by the generic
50 * dst layer to indicate that the entry has been forcefully
51 * destroyed.
52 *
53 * Negative values are used by the implementation layer code to
54 * force invocation of the dst_ops->check() method.
55 */
56 short obsolete;
57#define DST_OBSOLETE_NONE 0
58#define DST_OBSOLETE_DEAD 2
59#define DST_OBSOLETE_FORCE_CHK -1
60#define DST_OBSOLETE_KILL -2
61 unsigned short header_len; /* more space at head required */
62 unsigned short trailer_len; /* space to reserve at tail */
63
64 /*
65 * __rcuref wants to be on a different cache line from
66 * input/output/ops or performance tanks badly
67 */
68#ifdef CONFIG_64BIT
69 rcuref_t __rcuref; /* 64-bit offset 64 */
70#endif
71 int __use;
72 unsigned long lastuse;
73 struct rcu_head rcu_head;
74 short error;
75 short __pad;
76 __u32 tclassid;
77#ifndef CONFIG_64BIT
78 struct lwtunnel_state *lwtstate;
79 rcuref_t __rcuref; /* 32-bit offset 64 */
80#endif
81 netdevice_tracker dev_tracker;
82
83 /*
84 * Used by rtable and rt6_info. Moves lwtstate into the next cache
85 * line on 64bit so that lwtstate does not cause false sharing with
86 * __rcuref under contention of __rcuref. This also puts the
87 * frequently accessed members of rtable and rt6_info out of the
88 * __rcuref cache line.
89 */
90 struct list_head rt_uncached;
91 struct uncached_list *rt_uncached_list;
92#ifdef CONFIG_64BIT
93 struct lwtunnel_state *lwtstate;
94#endif
95};
96
97struct dst_metrics {
98 u32 metrics[RTAX_MAX];
99 refcount_t refcnt;
100} __aligned(4); /* Low pointer bits contain DST_METRICS_FLAGS */
101extern const struct dst_metrics dst_default_metrics;
102
103u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
104
105#define DST_METRICS_READ_ONLY 0x1UL
106#define DST_METRICS_REFCOUNTED 0x2UL
107#define DST_METRICS_FLAGS 0x3UL
108#define __DST_METRICS_PTR(Y) \
109 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
110#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
111
112static inline bool dst_metrics_read_only(const struct dst_entry *dst)
113{
114 return dst->_metrics & DST_METRICS_READ_ONLY;
115}
116
117void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
118
119static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
120{
121 unsigned long val = dst->_metrics;
122 if (!(val & DST_METRICS_READ_ONLY))
123 __dst_destroy_metrics_generic(dst, val);
124}
125
126static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
127{
128 unsigned long p = dst->_metrics;
129
130 BUG_ON(!p);
131
132 if (p & DST_METRICS_READ_ONLY)
133 return dst->ops->cow_metrics(dst, p);
134 return __DST_METRICS_PTR(p);
135}
136
137/* This may only be invoked before the entry has reached global
138 * visibility.
139 */
140static inline void dst_init_metrics(struct dst_entry *dst,
141 const u32 *src_metrics,
142 bool read_only)
143{
144 dst->_metrics = ((unsigned long) src_metrics) |
145 (read_only ? DST_METRICS_READ_ONLY : 0);
146}
147
148static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
149{
150 u32 *dst_metrics = dst_metrics_write_ptr(dest);
151
152 if (dst_metrics) {
153 u32 *src_metrics = DST_METRICS_PTR(src);
154
155 memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
156 }
157}
158
159static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
160{
161 return DST_METRICS_PTR(dst);
162}
163
164static inline u32
165dst_metric_raw(const struct dst_entry *dst, const int metric)
166{
167 u32 *p = DST_METRICS_PTR(dst);
168
169 return p[metric-1];
170}
171
172static inline u32
173dst_metric(const struct dst_entry *dst, const int metric)
174{
175 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
176 metric == RTAX_ADVMSS ||
177 metric == RTAX_MTU);
178 return dst_metric_raw(dst, metric);
179}
180
181static inline u32
182dst_metric_advmss(const struct dst_entry *dst)
183{
184 u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
185
186 if (!advmss)
187 advmss = dst->ops->default_advmss(dst);
188
189 return advmss;
190}
191
192static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
193{
194 u32 *p = dst_metrics_write_ptr(dst);
195
196 if (p)
197 p[metric-1] = val;
198}
199
200/* Kernel-internal feature bits that are unallocated in user space. */
201#define DST_FEATURE_ECN_CA (1U << 31)
202
203#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
204#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)
205
206static inline u32
207dst_feature(const struct dst_entry *dst, u32 feature)
208{
209 return dst_metric(dst, RTAX_FEATURES) & feature;
210}
211
212INDIRECT_CALLABLE_DECLARE(unsigned int ip6_mtu(const struct dst_entry *));
213INDIRECT_CALLABLE_DECLARE(unsigned int ipv4_mtu(const struct dst_entry *));
214static inline u32 dst_mtu(const struct dst_entry *dst)
215{
216 return INDIRECT_CALL_INET(dst->ops->mtu, ip6_mtu, ipv4_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 int
226dst_metric_locked(const struct dst_entry *dst, int metric)
227{
228 return dst_metric(dst, RTAX_LOCK) & (1 << metric);
229}
230
231static inline void dst_hold(struct dst_entry *dst)
232{
233 /*
234 * If your kernel compilation stops here, please check
235 * the placement of __rcuref in struct dst_entry
236 */
237 BUILD_BUG_ON(offsetof(struct dst_entry, __rcuref) & 63);
238 WARN_ON(!rcuref_get(&dst->__rcuref));
239}
240
241static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
242{
243 if (unlikely(time != dst->lastuse)) {
244 dst->__use++;
245 dst->lastuse = time;
246 }
247}
248
249static inline struct dst_entry *dst_clone(struct dst_entry *dst)
250{
251 if (dst)
252 dst_hold(dst);
253 return dst;
254}
255
256void dst_release(struct dst_entry *dst);
257
258void dst_release_immediate(struct dst_entry *dst);
259
260static inline void refdst_drop(unsigned long refdst)
261{
262 if (!(refdst & SKB_DST_NOREF))
263 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
264}
265
266/**
267 * skb_dst_drop - drops skb dst
268 * @skb: buffer
269 *
270 * Drops dst reference count if a reference was taken.
271 */
272static inline void skb_dst_drop(struct sk_buff *skb)
273{
274 if (skb->_skb_refdst) {
275 refdst_drop(skb->_skb_refdst);
276 skb->_skb_refdst = 0UL;
277 }
278}
279
280static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
281{
282 nskb->slow_gro |= !!refdst;
283 nskb->_skb_refdst = refdst;
284 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
285 dst_clone(skb_dst(nskb));
286}
287
288static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
289{
290 __skb_dst_copy(nskb, oskb->_skb_refdst);
291}
292
293/**
294 * dst_hold_safe - Take a reference on a dst if possible
295 * @dst: pointer to dst entry
296 *
297 * This helper returns false if it could not safely
298 * take a reference on a dst.
299 */
300static inline bool dst_hold_safe(struct dst_entry *dst)
301{
302 return rcuref_get(&dst->__rcuref);
303}
304
305/**
306 * skb_dst_force - makes sure skb dst is refcounted
307 * @skb: buffer
308 *
309 * If dst is not yet refcounted and not destroyed, grab a ref on it.
310 * Returns true if dst is refcounted.
311 */
312static inline bool skb_dst_force(struct sk_buff *skb)
313{
314 if (skb_dst_is_noref(skb)) {
315 struct dst_entry *dst = skb_dst(skb);
316
317 WARN_ON(!rcu_read_lock_held());
318 if (!dst_hold_safe(dst))
319 dst = NULL;
320
321 skb->_skb_refdst = (unsigned long)dst;
322 skb->slow_gro |= !!dst;
323 }
324
325 return skb->_skb_refdst != 0UL;
326}
327
328
329/**
330 * __skb_tunnel_rx - prepare skb for rx reinsert
331 * @skb: buffer
332 * @dev: tunnel device
333 * @net: netns for packet i/o
334 *
335 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
336 * so make some cleanups. (no accounting done)
337 */
338static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
339 struct net *net)
340{
341 skb->dev = dev;
342
343 /*
344 * Clear hash so that we can recalculate the hash for the
345 * encapsulated packet, unless we have already determine the hash
346 * over the L4 4-tuple.
347 */
348 skb_clear_hash_if_not_l4(skb);
349 skb_set_queue_mapping(skb, 0);
350 skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
351}
352
353/**
354 * skb_tunnel_rx - prepare skb for rx reinsert
355 * @skb: buffer
356 * @dev: tunnel device
357 * @net: netns for packet i/o
358 *
359 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
360 * so make some cleanups, and perform accounting.
361 * Note: this accounting is not SMP safe.
362 */
363static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
364 struct net *net)
365{
366 DEV_STATS_INC(dev, rx_packets);
367 DEV_STATS_ADD(dev, rx_bytes, skb->len);
368 __skb_tunnel_rx(skb, dev, net);
369}
370
371static inline u32 dst_tclassid(const struct sk_buff *skb)
372{
373#ifdef CONFIG_IP_ROUTE_CLASSID
374 const struct dst_entry *dst;
375
376 dst = skb_dst(skb);
377 if (dst)
378 return dst->tclassid;
379#endif
380 return 0;
381}
382
383int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
384static inline int dst_discard(struct sk_buff *skb)
385{
386 return dst_discard_out(&init_net, skb->sk, skb);
387}
388void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
389 int initial_obsolete, unsigned short flags);
390void dst_init(struct dst_entry *dst, struct dst_ops *ops,
391 struct net_device *dev, int initial_obsolete,
392 unsigned short flags);
393void dst_dev_put(struct dst_entry *dst);
394
395static inline void dst_confirm(struct dst_entry *dst)
396{
397}
398
399static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
400{
401 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
402 return IS_ERR(n) ? NULL : n;
403}
404
405static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
406 struct sk_buff *skb)
407{
408 struct neighbour *n;
409
410 if (WARN_ON_ONCE(!dst->ops->neigh_lookup))
411 return NULL;
412
413 n = dst->ops->neigh_lookup(dst, skb, NULL);
414
415 return IS_ERR(n) ? NULL : n;
416}
417
418static inline void dst_confirm_neigh(const struct dst_entry *dst,
419 const void *daddr)
420{
421 if (dst->ops->confirm_neigh)
422 dst->ops->confirm_neigh(dst, daddr);
423}
424
425static inline void dst_link_failure(struct sk_buff *skb)
426{
427 struct dst_entry *dst = skb_dst(skb);
428 if (dst && dst->ops && dst->ops->link_failure)
429 dst->ops->link_failure(skb);
430}
431
432static inline void dst_set_expires(struct dst_entry *dst, int timeout)
433{
434 unsigned long expires = jiffies + timeout;
435
436 if (expires == 0)
437 expires = 1;
438
439 if (dst->expires == 0 || time_before(expires, dst->expires))
440 dst->expires = expires;
441}
442
443static inline unsigned int dst_dev_overhead(struct dst_entry *dst,
444 struct sk_buff *skb)
445{
446 if (likely(dst))
447 return LL_RESERVED_SPACE(dst->dev);
448
449 return skb->mac_len;
450}
451
452INDIRECT_CALLABLE_DECLARE(int ip6_output(struct net *, struct sock *,
453 struct sk_buff *));
454INDIRECT_CALLABLE_DECLARE(int ip_output(struct net *, struct sock *,
455 struct sk_buff *));
456/* Output packet to network from transport. */
457static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
458{
459 return INDIRECT_CALL_INET(skb_dst(skb)->output,
460 ip6_output, ip_output,
461 net, sk, skb);
462}
463
464INDIRECT_CALLABLE_DECLARE(int ip6_input(struct sk_buff *));
465INDIRECT_CALLABLE_DECLARE(int ip_local_deliver(struct sk_buff *));
466/* Input packet from network to transport. */
467static inline int dst_input(struct sk_buff *skb)
468{
469 return INDIRECT_CALL_INET(skb_dst(skb)->input,
470 ip6_input, ip_local_deliver, skb);
471}
472
473INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
474 u32));
475INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
476 u32));
477static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
478{
479 if (dst->obsolete)
480 dst = INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check,
481 ipv4_dst_check, dst, cookie);
482 return dst;
483}
484
485/* Flags for xfrm_lookup flags argument. */
486enum {
487 XFRM_LOOKUP_ICMP = 1 << 0,
488 XFRM_LOOKUP_QUEUE = 1 << 1,
489 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
490};
491
492struct flowi;
493#ifndef CONFIG_XFRM
494static inline struct dst_entry *xfrm_lookup(struct net *net,
495 struct dst_entry *dst_orig,
496 const struct flowi *fl,
497 const struct sock *sk,
498 int flags)
499{
500 return dst_orig;
501}
502
503static inline struct dst_entry *
504xfrm_lookup_with_ifid(struct net *net, struct dst_entry *dst_orig,
505 const struct flowi *fl, const struct sock *sk,
506 int flags, u32 if_id)
507{
508 return dst_orig;
509}
510
511static inline struct dst_entry *xfrm_lookup_route(struct net *net,
512 struct dst_entry *dst_orig,
513 const struct flowi *fl,
514 const struct sock *sk,
515 int flags)
516{
517 return dst_orig;
518}
519
520static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
521{
522 return NULL;
523}
524
525#else
526struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
527 const struct flowi *fl, const struct sock *sk,
528 int flags);
529
530struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
531 struct dst_entry *dst_orig,
532 const struct flowi *fl,
533 const struct sock *sk, int flags,
534 u32 if_id);
535
536struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
537 const struct flowi *fl, const struct sock *sk,
538 int flags);
539
540/* skb attached with this dst needs transformation if dst->xfrm is valid */
541static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
542{
543 return dst->xfrm;
544}
545#endif
546
547static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
548{
549 struct dst_entry *dst = skb_dst(skb);
550
551 if (dst && dst->ops->update_pmtu)
552 dst->ops->update_pmtu(dst, NULL, skb, mtu, true);
553}
554
555/* update dst pmtu but not do neighbor confirm */
556static inline void skb_dst_update_pmtu_no_confirm(struct sk_buff *skb, u32 mtu)
557{
558 struct dst_entry *dst = skb_dst(skb);
559
560 if (dst && dst->ops->update_pmtu)
561 dst->ops->update_pmtu(dst, NULL, skb, mtu, false);
562}
563
564struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie);
565void dst_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
566 struct sk_buff *skb, u32 mtu, bool confirm_neigh);
567void dst_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
568 struct sk_buff *skb);
569u32 *dst_blackhole_cow_metrics(struct dst_entry *dst, unsigned long old);
570struct neighbour *dst_blackhole_neigh_lookup(const struct dst_entry *dst,
571 struct sk_buff *skb,
572 const void *daddr);
573unsigned int dst_blackhole_mtu(const struct dst_entry *dst);
574
575#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 */