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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 unsigned long expires;
40 struct dst_entry *path;
41 struct dst_entry *from;
42#ifdef CONFIG_XFRM
43 struct xfrm_state *xfrm;
44#else
45 void *__pad1;
46#endif
47 int (*input)(struct sk_buff *);
48 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
49
50 unsigned short flags;
51#define DST_HOST 0x0001
52#define DST_NOXFRM 0x0002
53#define DST_NOPOLICY 0x0004
54#define DST_NOHASH 0x0008
55#define DST_NOCACHE 0x0010
56#define DST_NOCOUNT 0x0020
57#define DST_FAKE_RTABLE 0x0040
58#define DST_XFRM_TUNNEL 0x0080
59#define DST_XFRM_QUEUE 0x0100
60#define DST_METADATA 0x0200
61
62 unsigned short pending_confirm;
63
64 short error;
65
66 /* A non-zero value of dst->obsolete forces by-hand validation
67 * of the route entry. Positive values are set by the generic
68 * dst layer to indicate that the entry has been forcefully
69 * destroyed.
70 *
71 * Negative values are used by the implementation layer code to
72 * force invocation of the dst_ops->check() method.
73 */
74 short obsolete;
75#define DST_OBSOLETE_NONE 0
76#define DST_OBSOLETE_DEAD 2
77#define DST_OBSOLETE_FORCE_CHK -1
78#define DST_OBSOLETE_KILL -2
79 unsigned short header_len; /* more space at head required */
80 unsigned short trailer_len; /* space to reserve at tail */
81#ifdef CONFIG_IP_ROUTE_CLASSID
82 __u32 tclassid;
83#else
84 __u32 __pad2;
85#endif
86
87#ifdef CONFIG_64BIT
88 struct lwtunnel_state *lwtstate;
89 /*
90 * Align __refcnt to a 64 bytes alignment
91 * (L1_CACHE_SIZE would be too much)
92 */
93 long __pad_to_align_refcnt[1];
94#endif
95 /*
96 * __refcnt wants to be on a different cache line from
97 * input/output/ops or performance tanks badly
98 */
99 atomic_t __refcnt; /* client references */
100 int __use;
101 unsigned long lastuse;
102#ifndef CONFIG_64BIT
103 struct lwtunnel_state *lwtstate;
104#endif
105 union {
106 struct dst_entry *next;
107 struct rtable __rcu *rt_next;
108 struct rt6_info *rt6_next;
109 struct dn_route __rcu *dn_next;
110 };
111};
112
113u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
114extern const u32 dst_default_metrics[];
115
116#define DST_METRICS_READ_ONLY 0x1UL
117#define DST_METRICS_FLAGS 0x3UL
118#define __DST_METRICS_PTR(Y) \
119 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
120#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
121
122static inline bool dst_metrics_read_only(const struct dst_entry *dst)
123{
124 return dst->_metrics & DST_METRICS_READ_ONLY;
125}
126
127void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
128
129static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
130{
131 unsigned long val = dst->_metrics;
132 if (!(val & DST_METRICS_READ_ONLY))
133 __dst_destroy_metrics_generic(dst, val);
134}
135
136static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
137{
138 unsigned long p = dst->_metrics;
139
140 BUG_ON(!p);
141
142 if (p & DST_METRICS_READ_ONLY)
143 return dst->ops->cow_metrics(dst, p);
144 return __DST_METRICS_PTR(p);
145}
146
147/* This may only be invoked before the entry has reached global
148 * visibility.
149 */
150static inline void dst_init_metrics(struct dst_entry *dst,
151 const u32 *src_metrics,
152 bool read_only)
153{
154 dst->_metrics = ((unsigned long) src_metrics) |
155 (read_only ? DST_METRICS_READ_ONLY : 0);
156}
157
158static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
159{
160 u32 *dst_metrics = dst_metrics_write_ptr(dest);
161
162 if (dst_metrics) {
163 u32 *src_metrics = DST_METRICS_PTR(src);
164
165 memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
166 }
167}
168
169static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
170{
171 return DST_METRICS_PTR(dst);
172}
173
174static inline u32
175dst_metric_raw(const struct dst_entry *dst, const int metric)
176{
177 u32 *p = DST_METRICS_PTR(dst);
178
179 return p[metric-1];
180}
181
182static inline u32
183dst_metric(const struct dst_entry *dst, const int metric)
184{
185 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
186 metric == RTAX_ADVMSS ||
187 metric == RTAX_MTU);
188 return dst_metric_raw(dst, metric);
189}
190
191static inline u32
192dst_metric_advmss(const struct dst_entry *dst)
193{
194 u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
195
196 if (!advmss)
197 advmss = dst->ops->default_advmss(dst);
198
199 return advmss;
200}
201
202static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
203{
204 u32 *p = dst_metrics_write_ptr(dst);
205
206 if (p)
207 p[metric-1] = val;
208}
209
210/* Kernel-internal feature bits that are unallocated in user space. */
211#define DST_FEATURE_ECN_CA (1 << 31)
212
213#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
214#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)
215
216static inline u32
217dst_feature(const struct dst_entry *dst, u32 feature)
218{
219 return dst_metric(dst, RTAX_FEATURES) & feature;
220}
221
222static inline u32 dst_mtu(const struct dst_entry *dst)
223{
224 return dst->ops->mtu(dst);
225}
226
227/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
228static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
229{
230 return msecs_to_jiffies(dst_metric(dst, metric));
231}
232
233static inline u32
234dst_allfrag(const struct dst_entry *dst)
235{
236 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
237 return ret;
238}
239
240static inline int
241dst_metric_locked(const struct dst_entry *dst, int metric)
242{
243 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
244}
245
246static inline void dst_hold(struct dst_entry *dst)
247{
248 /*
249 * If your kernel compilation stops here, please check
250 * __pad_to_align_refcnt declaration in struct dst_entry
251 */
252 BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
253 atomic_inc(&dst->__refcnt);
254}
255
256static inline void dst_use(struct dst_entry *dst, unsigned long time)
257{
258 dst_hold(dst);
259 dst->__use++;
260 dst->lastuse = time;
261}
262
263static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
264{
265 dst->__use++;
266 dst->lastuse = time;
267}
268
269static inline struct dst_entry *dst_clone(struct dst_entry *dst)
270{
271 if (dst)
272 atomic_inc(&dst->__refcnt);
273 return dst;
274}
275
276void dst_release(struct dst_entry *dst);
277
278static inline void refdst_drop(unsigned long refdst)
279{
280 if (!(refdst & SKB_DST_NOREF))
281 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
282}
283
284/**
285 * skb_dst_drop - drops skb dst
286 * @skb: buffer
287 *
288 * Drops dst reference count if a reference was taken.
289 */
290static inline void skb_dst_drop(struct sk_buff *skb)
291{
292 if (skb->_skb_refdst) {
293 refdst_drop(skb->_skb_refdst);
294 skb->_skb_refdst = 0UL;
295 }
296}
297
298static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
299{
300 nskb->_skb_refdst = refdst;
301 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
302 dst_clone(skb_dst(nskb));
303}
304
305static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
306{
307 __skb_dst_copy(nskb, oskb->_skb_refdst);
308}
309
310/**
311 * skb_dst_force - makes sure skb dst is refcounted
312 * @skb: buffer
313 *
314 * If dst is not yet refcounted, let's do it
315 */
316static inline void skb_dst_force(struct sk_buff *skb)
317{
318 if (skb_dst_is_noref(skb)) {
319 WARN_ON(!rcu_read_lock_held());
320 skb->_skb_refdst &= ~SKB_DST_NOREF;
321 dst_clone(skb_dst(skb));
322 }
323}
324
325/**
326 * dst_hold_safe - Take a reference on a dst if possible
327 * @dst: pointer to dst entry
328 *
329 * This helper returns false if it could not safely
330 * take a reference on a dst.
331 */
332static inline bool dst_hold_safe(struct dst_entry *dst)
333{
334 if (dst->flags & DST_NOCACHE)
335 return atomic_inc_not_zero(&dst->__refcnt);
336 dst_hold(dst);
337 return true;
338}
339
340/**
341 * skb_dst_force_safe - makes sure skb dst is refcounted
342 * @skb: buffer
343 *
344 * If dst is not yet refcounted and not destroyed, grab a ref on it.
345 */
346static inline void skb_dst_force_safe(struct sk_buff *skb)
347{
348 if (skb_dst_is_noref(skb)) {
349 struct dst_entry *dst = skb_dst(skb);
350
351 if (!dst_hold_safe(dst))
352 dst = NULL;
353
354 skb->_skb_refdst = (unsigned long)dst;
355 }
356}
357
358
359/**
360 * __skb_tunnel_rx - prepare skb for rx reinsert
361 * @skb: buffer
362 * @dev: tunnel device
363 * @net: netns for packet i/o
364 *
365 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
366 * so make some cleanups. (no accounting done)
367 */
368static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
369 struct net *net)
370{
371 skb->dev = dev;
372
373 /*
374 * Clear hash so that we can recalulate the hash for the
375 * encapsulated packet, unless we have already determine the hash
376 * over the L4 4-tuple.
377 */
378 skb_clear_hash_if_not_l4(skb);
379 skb_set_queue_mapping(skb, 0);
380 skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
381}
382
383/**
384 * skb_tunnel_rx - prepare skb for rx reinsert
385 * @skb: buffer
386 * @dev: tunnel device
387 *
388 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
389 * so make some cleanups, and perform accounting.
390 * Note: this accounting is not SMP safe.
391 */
392static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
393 struct net *net)
394{
395 /* TODO : stats should be SMP safe */
396 dev->stats.rx_packets++;
397 dev->stats.rx_bytes += skb->len;
398 __skb_tunnel_rx(skb, dev, net);
399}
400
401static inline u32 dst_tclassid(const struct sk_buff *skb)
402{
403#ifdef CONFIG_IP_ROUTE_CLASSID
404 const struct dst_entry *dst;
405
406 dst = skb_dst(skb);
407 if (dst)
408 return dst->tclassid;
409#endif
410 return 0;
411}
412
413int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
414static inline int dst_discard(struct sk_buff *skb)
415{
416 return dst_discard_out(&init_net, skb->sk, skb);
417}
418void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
419 int initial_obsolete, unsigned short flags);
420void dst_init(struct dst_entry *dst, struct dst_ops *ops,
421 struct net_device *dev, int initial_ref, int initial_obsolete,
422 unsigned short flags);
423void __dst_free(struct dst_entry *dst);
424struct dst_entry *dst_destroy(struct dst_entry *dst);
425
426static inline void dst_free(struct dst_entry *dst)
427{
428 if (dst->obsolete > 0)
429 return;
430 if (!atomic_read(&dst->__refcnt)) {
431 dst = dst_destroy(dst);
432 if (!dst)
433 return;
434 }
435 __dst_free(dst);
436}
437
438static inline void dst_rcu_free(struct rcu_head *head)
439{
440 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
441 dst_free(dst);
442}
443
444static inline void dst_confirm(struct dst_entry *dst)
445{
446 dst->pending_confirm = 1;
447}
448
449static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
450 struct sk_buff *skb)
451{
452 const struct hh_cache *hh;
453
454 if (dst->pending_confirm) {
455 unsigned long now = jiffies;
456
457 dst->pending_confirm = 0;
458 /* avoid dirtying neighbour */
459 if (n->confirmed != now)
460 n->confirmed = now;
461 }
462
463 hh = &n->hh;
464 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
465 return neigh_hh_output(hh, skb);
466 else
467 return n->output(n, skb);
468}
469
470static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
471{
472 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
473 return IS_ERR(n) ? NULL : n;
474}
475
476static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
477 struct sk_buff *skb)
478{
479 struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
480 return IS_ERR(n) ? NULL : n;
481}
482
483static inline void dst_link_failure(struct sk_buff *skb)
484{
485 struct dst_entry *dst = skb_dst(skb);
486 if (dst && dst->ops && dst->ops->link_failure)
487 dst->ops->link_failure(skb);
488}
489
490static inline void dst_set_expires(struct dst_entry *dst, int timeout)
491{
492 unsigned long expires = jiffies + timeout;
493
494 if (expires == 0)
495 expires = 1;
496
497 if (dst->expires == 0 || time_before(expires, dst->expires))
498 dst->expires = expires;
499}
500
501/* Output packet to network from transport. */
502static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
503{
504 return skb_dst(skb)->output(net, sk, skb);
505}
506
507/* Input packet from network to transport. */
508static inline int dst_input(struct sk_buff *skb)
509{
510 return skb_dst(skb)->input(skb);
511}
512
513static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
514{
515 if (dst->obsolete)
516 dst = dst->ops->check(dst, cookie);
517 return dst;
518}
519
520void dst_subsys_init(void);
521
522/* Flags for xfrm_lookup flags argument. */
523enum {
524 XFRM_LOOKUP_ICMP = 1 << 0,
525 XFRM_LOOKUP_QUEUE = 1 << 1,
526 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
527};
528
529struct flowi;
530#ifndef CONFIG_XFRM
531static inline struct dst_entry *xfrm_lookup(struct net *net,
532 struct dst_entry *dst_orig,
533 const struct flowi *fl,
534 const struct sock *sk,
535 int flags)
536{
537 return dst_orig;
538}
539
540static inline struct dst_entry *xfrm_lookup_route(struct net *net,
541 struct dst_entry *dst_orig,
542 const struct flowi *fl,
543 const struct sock *sk,
544 int flags)
545{
546 return dst_orig;
547}
548
549static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
550{
551 return NULL;
552}
553
554#else
555struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
556 const struct flowi *fl, const struct sock *sk,
557 int flags);
558
559struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
560 const struct flowi *fl, const struct sock *sk,
561 int flags);
562
563/* skb attached with this dst needs transformation if dst->xfrm is valid */
564static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
565{
566 return dst->xfrm;
567}
568#endif
569
570#endif /* _NET_DST_H */