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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 netdevice_tracker dev_tracker;
81};
82
83struct dst_metrics {
84 u32 metrics[RTAX_MAX];
85 refcount_t refcnt;
86} __aligned(4); /* Low pointer bits contain DST_METRICS_FLAGS */
87extern const struct dst_metrics dst_default_metrics;
88
89u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
90
91#define DST_METRICS_READ_ONLY 0x1UL
92#define DST_METRICS_REFCOUNTED 0x2UL
93#define DST_METRICS_FLAGS 0x3UL
94#define __DST_METRICS_PTR(Y) \
95 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
96#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
97
98static inline bool dst_metrics_read_only(const struct dst_entry *dst)
99{
100 return dst->_metrics & DST_METRICS_READ_ONLY;
101}
102
103void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
104
105static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
106{
107 unsigned long val = dst->_metrics;
108 if (!(val & DST_METRICS_READ_ONLY))
109 __dst_destroy_metrics_generic(dst, val);
110}
111
112static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
113{
114 unsigned long p = dst->_metrics;
115
116 BUG_ON(!p);
117
118 if (p & DST_METRICS_READ_ONLY)
119 return dst->ops->cow_metrics(dst, p);
120 return __DST_METRICS_PTR(p);
121}
122
123/* This may only be invoked before the entry has reached global
124 * visibility.
125 */
126static inline void dst_init_metrics(struct dst_entry *dst,
127 const u32 *src_metrics,
128 bool read_only)
129{
130 dst->_metrics = ((unsigned long) src_metrics) |
131 (read_only ? DST_METRICS_READ_ONLY : 0);
132}
133
134static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
135{
136 u32 *dst_metrics = dst_metrics_write_ptr(dest);
137
138 if (dst_metrics) {
139 u32 *src_metrics = DST_METRICS_PTR(src);
140
141 memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
142 }
143}
144
145static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
146{
147 return DST_METRICS_PTR(dst);
148}
149
150static inline u32
151dst_metric_raw(const struct dst_entry *dst, const int metric)
152{
153 u32 *p = DST_METRICS_PTR(dst);
154
155 return p[metric-1];
156}
157
158static inline u32
159dst_metric(const struct dst_entry *dst, const int metric)
160{
161 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
162 metric == RTAX_ADVMSS ||
163 metric == RTAX_MTU);
164 return dst_metric_raw(dst, metric);
165}
166
167static inline u32
168dst_metric_advmss(const struct dst_entry *dst)
169{
170 u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
171
172 if (!advmss)
173 advmss = dst->ops->default_advmss(dst);
174
175 return advmss;
176}
177
178static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
179{
180 u32 *p = dst_metrics_write_ptr(dst);
181
182 if (p)
183 p[metric-1] = val;
184}
185
186/* Kernel-internal feature bits that are unallocated in user space. */
187#define DST_FEATURE_ECN_CA (1U << 31)
188
189#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
190#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)
191
192static inline u32
193dst_feature(const struct dst_entry *dst, u32 feature)
194{
195 return dst_metric(dst, RTAX_FEATURES) & feature;
196}
197
198INDIRECT_CALLABLE_DECLARE(unsigned int ip6_mtu(const struct dst_entry *));
199INDIRECT_CALLABLE_DECLARE(unsigned int ipv4_mtu(const struct dst_entry *));
200static inline u32 dst_mtu(const struct dst_entry *dst)
201{
202 return INDIRECT_CALL_INET(dst->ops->mtu, ip6_mtu, ipv4_mtu, dst);
203}
204
205/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
206static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
207{
208 return msecs_to_jiffies(dst_metric(dst, metric));
209}
210
211static inline u32
212dst_allfrag(const struct dst_entry *dst)
213{
214 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
215 return ret;
216}
217
218static inline int
219dst_metric_locked(const struct dst_entry *dst, int metric)
220{
221 return dst_metric(dst, RTAX_LOCK) & (1 << metric);
222}
223
224static inline void dst_hold(struct dst_entry *dst)
225{
226 /*
227 * If your kernel compilation stops here, please check
228 * the placement of __refcnt in struct dst_entry
229 */
230 BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
231 WARN_ON(atomic_inc_not_zero(&dst->__refcnt) == 0);
232}
233
234static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
235{
236 if (unlikely(time != dst->lastuse)) {
237 dst->__use++;
238 dst->lastuse = time;
239 }
240}
241
242static inline struct dst_entry *dst_clone(struct dst_entry *dst)
243{
244 if (dst)
245 dst_hold(dst);
246 return dst;
247}
248
249void dst_release(struct dst_entry *dst);
250
251void dst_release_immediate(struct dst_entry *dst);
252
253static inline void refdst_drop(unsigned long refdst)
254{
255 if (!(refdst & SKB_DST_NOREF))
256 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
257}
258
259/**
260 * skb_dst_drop - drops skb dst
261 * @skb: buffer
262 *
263 * Drops dst reference count if a reference was taken.
264 */
265static inline void skb_dst_drop(struct sk_buff *skb)
266{
267 if (skb->_skb_refdst) {
268 refdst_drop(skb->_skb_refdst);
269 skb->_skb_refdst = 0UL;
270 }
271}
272
273static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
274{
275 nskb->slow_gro |= !!refdst;
276 nskb->_skb_refdst = refdst;
277 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
278 dst_clone(skb_dst(nskb));
279}
280
281static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
282{
283 __skb_dst_copy(nskb, oskb->_skb_refdst);
284}
285
286/**
287 * dst_hold_safe - Take a reference on a dst if possible
288 * @dst: pointer to dst entry
289 *
290 * This helper returns false if it could not safely
291 * take a reference on a dst.
292 */
293static inline bool dst_hold_safe(struct dst_entry *dst)
294{
295 return atomic_inc_not_zero(&dst->__refcnt);
296}
297
298/**
299 * skb_dst_force - makes sure skb dst is refcounted
300 * @skb: buffer
301 *
302 * If dst is not yet refcounted and not destroyed, grab a ref on it.
303 * Returns true if dst is refcounted.
304 */
305static inline bool skb_dst_force(struct sk_buff *skb)
306{
307 if (skb_dst_is_noref(skb)) {
308 struct dst_entry *dst = skb_dst(skb);
309
310 WARN_ON(!rcu_read_lock_held());
311 if (!dst_hold_safe(dst))
312 dst = NULL;
313
314 skb->_skb_refdst = (unsigned long)dst;
315 skb->slow_gro |= !!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 DEV_STATS_INC(dev, rx_packets);
360 DEV_STATS_ADD(dev, rx_bytes, skb->len);
361 __skb_tunnel_rx(skb, dev, net);
362}
363
364static inline u32 dst_tclassid(const struct sk_buff *skb)
365{
366#ifdef CONFIG_IP_ROUTE_CLASSID
367 const struct dst_entry *dst;
368
369 dst = skb_dst(skb);
370 if (dst)
371 return dst->tclassid;
372#endif
373 return 0;
374}
375
376int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
377static inline int dst_discard(struct sk_buff *skb)
378{
379 return dst_discard_out(&init_net, skb->sk, skb);
380}
381void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
382 int initial_obsolete, unsigned short flags);
383void dst_init(struct dst_entry *dst, struct dst_ops *ops,
384 struct net_device *dev, int initial_ref, int initial_obsolete,
385 unsigned short flags);
386struct dst_entry *dst_destroy(struct dst_entry *dst);
387void dst_dev_put(struct dst_entry *dst);
388
389static inline void dst_confirm(struct dst_entry *dst)
390{
391}
392
393static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
394{
395 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
396 return IS_ERR(n) ? NULL : n;
397}
398
399static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
400 struct sk_buff *skb)
401{
402 struct neighbour *n;
403
404 if (WARN_ON_ONCE(!dst->ops->neigh_lookup))
405 return NULL;
406
407 n = dst->ops->neigh_lookup(dst, skb, NULL);
408
409 return IS_ERR(n) ? NULL : n;
410}
411
412static inline void dst_confirm_neigh(const struct dst_entry *dst,
413 const void *daddr)
414{
415 if (dst->ops->confirm_neigh)
416 dst->ops->confirm_neigh(dst, daddr);
417}
418
419static inline void dst_link_failure(struct sk_buff *skb)
420{
421 struct dst_entry *dst = skb_dst(skb);
422 if (dst && dst->ops && dst->ops->link_failure)
423 dst->ops->link_failure(skb);
424}
425
426static inline void dst_set_expires(struct dst_entry *dst, int timeout)
427{
428 unsigned long expires = jiffies + timeout;
429
430 if (expires == 0)
431 expires = 1;
432
433 if (dst->expires == 0 || time_before(expires, dst->expires))
434 dst->expires = expires;
435}
436
437INDIRECT_CALLABLE_DECLARE(int ip6_output(struct net *, struct sock *,
438 struct sk_buff *));
439INDIRECT_CALLABLE_DECLARE(int ip_output(struct net *, struct sock *,
440 struct sk_buff *));
441/* Output packet to network from transport. */
442static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
443{
444 return INDIRECT_CALL_INET(skb_dst(skb)->output,
445 ip6_output, ip_output,
446 net, sk, skb);
447}
448
449INDIRECT_CALLABLE_DECLARE(int ip6_input(struct sk_buff *));
450INDIRECT_CALLABLE_DECLARE(int ip_local_deliver(struct sk_buff *));
451/* Input packet from network to transport. */
452static inline int dst_input(struct sk_buff *skb)
453{
454 return INDIRECT_CALL_INET(skb_dst(skb)->input,
455 ip6_input, ip_local_deliver, skb);
456}
457
458INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
459 u32));
460INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
461 u32));
462static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
463{
464 if (dst->obsolete)
465 dst = INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check,
466 ipv4_dst_check, dst, cookie);
467 return dst;
468}
469
470/* Flags for xfrm_lookup flags argument. */
471enum {
472 XFRM_LOOKUP_ICMP = 1 << 0,
473 XFRM_LOOKUP_QUEUE = 1 << 1,
474 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
475};
476
477struct flowi;
478#ifndef CONFIG_XFRM
479static inline struct dst_entry *xfrm_lookup(struct net *net,
480 struct dst_entry *dst_orig,
481 const struct flowi *fl,
482 const struct sock *sk,
483 int flags)
484{
485 return dst_orig;
486}
487
488static inline struct dst_entry *
489xfrm_lookup_with_ifid(struct net *net, struct dst_entry *dst_orig,
490 const struct flowi *fl, const struct sock *sk,
491 int flags, u32 if_id)
492{
493 return dst_orig;
494}
495
496static inline struct dst_entry *xfrm_lookup_route(struct net *net,
497 struct dst_entry *dst_orig,
498 const struct flowi *fl,
499 const struct sock *sk,
500 int flags)
501{
502 return dst_orig;
503}
504
505static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
506{
507 return NULL;
508}
509
510#else
511struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
512 const struct flowi *fl, const struct sock *sk,
513 int flags);
514
515struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
516 struct dst_entry *dst_orig,
517 const struct flowi *fl,
518 const struct sock *sk, int flags,
519 u32 if_id);
520
521struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
522 const struct flowi *fl, const struct sock *sk,
523 int flags);
524
525/* skb attached with this dst needs transformation if dst->xfrm is valid */
526static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
527{
528 return dst->xfrm;
529}
530#endif
531
532static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
533{
534 struct dst_entry *dst = skb_dst(skb);
535
536 if (dst && dst->ops->update_pmtu)
537 dst->ops->update_pmtu(dst, NULL, skb, mtu, true);
538}
539
540/* update dst pmtu but not do neighbor confirm */
541static inline void skb_dst_update_pmtu_no_confirm(struct sk_buff *skb, u32 mtu)
542{
543 struct dst_entry *dst = skb_dst(skb);
544
545 if (dst && dst->ops->update_pmtu)
546 dst->ops->update_pmtu(dst, NULL, skb, mtu, false);
547}
548
549struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie);
550void dst_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
551 struct sk_buff *skb, u32 mtu, bool confirm_neigh);
552void dst_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
553 struct sk_buff *skb);
554u32 *dst_blackhole_cow_metrics(struct dst_entry *dst, unsigned long old);
555struct neighbour *dst_blackhole_neigh_lookup(const struct dst_entry *dst,
556 struct sk_buff *skb,
557 const void *daddr);
558unsigned int dst_blackhole_mtu(const struct dst_entry *dst);
559
560#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 /*
89 * Align __refcnt to a 64 bytes alignment
90 * (L1_CACHE_SIZE would be too much)
91 */
92 long __pad_to_align_refcnt[2];
93#endif
94 /*
95 * __refcnt wants to be on a different cache line from
96 * input/output/ops or performance tanks badly
97 */
98 atomic_t __refcnt; /* client references */
99 int __use;
100 unsigned long lastuse;
101 struct lwtunnel_state *lwtstate;
102 union {
103 struct dst_entry *next;
104 struct rtable __rcu *rt_next;
105 struct rt6_info *rt6_next;
106 struct dn_route __rcu *dn_next;
107 };
108};
109
110u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
111extern const u32 dst_default_metrics[];
112
113#define DST_METRICS_READ_ONLY 0x1UL
114#define DST_METRICS_FLAGS 0x3UL
115#define __DST_METRICS_PTR(Y) \
116 ((u32 *)((Y) & ~DST_METRICS_FLAGS))
117#define DST_METRICS_PTR(X) __DST_METRICS_PTR((X)->_metrics)
118
119static inline bool dst_metrics_read_only(const struct dst_entry *dst)
120{
121 return dst->_metrics & DST_METRICS_READ_ONLY;
122}
123
124void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old);
125
126static inline void dst_destroy_metrics_generic(struct dst_entry *dst)
127{
128 unsigned long val = dst->_metrics;
129 if (!(val & DST_METRICS_READ_ONLY))
130 __dst_destroy_metrics_generic(dst, val);
131}
132
133static inline u32 *dst_metrics_write_ptr(struct dst_entry *dst)
134{
135 unsigned long p = dst->_metrics;
136
137 BUG_ON(!p);
138
139 if (p & DST_METRICS_READ_ONLY)
140 return dst->ops->cow_metrics(dst, p);
141 return __DST_METRICS_PTR(p);
142}
143
144/* This may only be invoked before the entry has reached global
145 * visibility.
146 */
147static inline void dst_init_metrics(struct dst_entry *dst,
148 const u32 *src_metrics,
149 bool read_only)
150{
151 dst->_metrics = ((unsigned long) src_metrics) |
152 (read_only ? DST_METRICS_READ_ONLY : 0);
153}
154
155static inline void dst_copy_metrics(struct dst_entry *dest, const struct dst_entry *src)
156{
157 u32 *dst_metrics = dst_metrics_write_ptr(dest);
158
159 if (dst_metrics) {
160 u32 *src_metrics = DST_METRICS_PTR(src);
161
162 memcpy(dst_metrics, src_metrics, RTAX_MAX * sizeof(u32));
163 }
164}
165
166static inline u32 *dst_metrics_ptr(struct dst_entry *dst)
167{
168 return DST_METRICS_PTR(dst);
169}
170
171static inline u32
172dst_metric_raw(const struct dst_entry *dst, const int metric)
173{
174 u32 *p = DST_METRICS_PTR(dst);
175
176 return p[metric-1];
177}
178
179static inline u32
180dst_metric(const struct dst_entry *dst, const int metric)
181{
182 WARN_ON_ONCE(metric == RTAX_HOPLIMIT ||
183 metric == RTAX_ADVMSS ||
184 metric == RTAX_MTU);
185 return dst_metric_raw(dst, metric);
186}
187
188static inline u32
189dst_metric_advmss(const struct dst_entry *dst)
190{
191 u32 advmss = dst_metric_raw(dst, RTAX_ADVMSS);
192
193 if (!advmss)
194 advmss = dst->ops->default_advmss(dst);
195
196 return advmss;
197}
198
199static inline void dst_metric_set(struct dst_entry *dst, int metric, u32 val)
200{
201 u32 *p = dst_metrics_write_ptr(dst);
202
203 if (p)
204 p[metric-1] = val;
205}
206
207/* Kernel-internal feature bits that are unallocated in user space. */
208#define DST_FEATURE_ECN_CA (1 << 31)
209
210#define DST_FEATURE_MASK (DST_FEATURE_ECN_CA)
211#define DST_FEATURE_ECN_MASK (DST_FEATURE_ECN_CA | RTAX_FEATURE_ECN)
212
213static inline u32
214dst_feature(const struct dst_entry *dst, u32 feature)
215{
216 return dst_metric(dst, RTAX_FEATURES) & feature;
217}
218
219static inline u32 dst_mtu(const struct dst_entry *dst)
220{
221 return dst->ops->mtu(dst);
222}
223
224/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
225static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
226{
227 return msecs_to_jiffies(dst_metric(dst, metric));
228}
229
230static inline u32
231dst_allfrag(const struct dst_entry *dst)
232{
233 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
234 return ret;
235}
236
237static inline int
238dst_metric_locked(const struct dst_entry *dst, int metric)
239{
240 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
241}
242
243static inline void dst_hold(struct dst_entry *dst)
244{
245 /*
246 * If your kernel compilation stops here, please check
247 * __pad_to_align_refcnt declaration in struct dst_entry
248 */
249 BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
250 atomic_inc(&dst->__refcnt);
251}
252
253static inline void dst_use(struct dst_entry *dst, unsigned long time)
254{
255 dst_hold(dst);
256 dst->__use++;
257 dst->lastuse = time;
258}
259
260static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
261{
262 dst->__use++;
263 dst->lastuse = time;
264}
265
266static inline struct dst_entry *dst_clone(struct dst_entry *dst)
267{
268 if (dst)
269 atomic_inc(&dst->__refcnt);
270 return dst;
271}
272
273void dst_release(struct dst_entry *dst);
274
275static inline void refdst_drop(unsigned long refdst)
276{
277 if (!(refdst & SKB_DST_NOREF))
278 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
279}
280
281/**
282 * skb_dst_drop - drops skb dst
283 * @skb: buffer
284 *
285 * Drops dst reference count if a reference was taken.
286 */
287static inline void skb_dst_drop(struct sk_buff *skb)
288{
289 if (skb->_skb_refdst) {
290 refdst_drop(skb->_skb_refdst);
291 skb->_skb_refdst = 0UL;
292 }
293}
294
295static inline void __skb_dst_copy(struct sk_buff *nskb, unsigned long refdst)
296{
297 nskb->_skb_refdst = refdst;
298 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
299 dst_clone(skb_dst(nskb));
300}
301
302static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
303{
304 __skb_dst_copy(nskb, oskb->_skb_refdst);
305}
306
307/**
308 * skb_dst_force - makes sure skb dst is refcounted
309 * @skb: buffer
310 *
311 * If dst is not yet refcounted, let's do it
312 */
313static inline void skb_dst_force(struct sk_buff *skb)
314{
315 if (skb_dst_is_noref(skb)) {
316 WARN_ON(!rcu_read_lock_held());
317 skb->_skb_refdst &= ~SKB_DST_NOREF;
318 dst_clone(skb_dst(skb));
319 }
320}
321
322/**
323 * dst_hold_safe - Take a reference on a dst if possible
324 * @dst: pointer to dst entry
325 *
326 * This helper returns false if it could not safely
327 * take a reference on a dst.
328 */
329static inline bool dst_hold_safe(struct dst_entry *dst)
330{
331 if (dst->flags & DST_NOCACHE)
332 return atomic_inc_not_zero(&dst->__refcnt);
333 dst_hold(dst);
334 return true;
335}
336
337/**
338 * skb_dst_force_safe - makes sure skb dst is refcounted
339 * @skb: buffer
340 *
341 * If dst is not yet refcounted and not destroyed, grab a ref on it.
342 */
343static inline void skb_dst_force_safe(struct sk_buff *skb)
344{
345 if (skb_dst_is_noref(skb)) {
346 struct dst_entry *dst = skb_dst(skb);
347
348 if (!dst_hold_safe(dst))
349 dst = NULL;
350
351 skb->_skb_refdst = (unsigned long)dst;
352 }
353}
354
355
356/**
357 * __skb_tunnel_rx - prepare skb for rx reinsert
358 * @skb: buffer
359 * @dev: tunnel device
360 * @net: netns for packet i/o
361 *
362 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
363 * so make some cleanups. (no accounting done)
364 */
365static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
366 struct net *net)
367{
368 skb->dev = dev;
369
370 /*
371 * Clear hash so that we can recalulate the hash for the
372 * encapsulated packet, unless we have already determine the hash
373 * over the L4 4-tuple.
374 */
375 skb_clear_hash_if_not_l4(skb);
376 skb_set_queue_mapping(skb, 0);
377 skb_scrub_packet(skb, !net_eq(net, dev_net(dev)));
378}
379
380/**
381 * skb_tunnel_rx - prepare skb for rx reinsert
382 * @skb: buffer
383 * @dev: tunnel device
384 *
385 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
386 * so make some cleanups, and perform accounting.
387 * Note: this accounting is not SMP safe.
388 */
389static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev,
390 struct net *net)
391{
392 /* TODO : stats should be SMP safe */
393 dev->stats.rx_packets++;
394 dev->stats.rx_bytes += skb->len;
395 __skb_tunnel_rx(skb, dev, net);
396}
397
398static inline u32 dst_tclassid(const struct sk_buff *skb)
399{
400#ifdef CONFIG_IP_ROUTE_CLASSID
401 const struct dst_entry *dst;
402
403 dst = skb_dst(skb);
404 if (dst)
405 return dst->tclassid;
406#endif
407 return 0;
408}
409
410int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
411static inline int dst_discard(struct sk_buff *skb)
412{
413 return dst_discard_out(&init_net, skb->sk, skb);
414}
415void *dst_alloc(struct dst_ops *ops, struct net_device *dev, int initial_ref,
416 int initial_obsolete, unsigned short flags);
417void dst_init(struct dst_entry *dst, struct dst_ops *ops,
418 struct net_device *dev, int initial_ref, int initial_obsolete,
419 unsigned short flags);
420void __dst_free(struct dst_entry *dst);
421struct dst_entry *dst_destroy(struct dst_entry *dst);
422
423static inline void dst_free(struct dst_entry *dst)
424{
425 if (dst->obsolete > 0)
426 return;
427 if (!atomic_read(&dst->__refcnt)) {
428 dst = dst_destroy(dst);
429 if (!dst)
430 return;
431 }
432 __dst_free(dst);
433}
434
435static inline void dst_rcu_free(struct rcu_head *head)
436{
437 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
438 dst_free(dst);
439}
440
441static inline void dst_confirm(struct dst_entry *dst)
442{
443 dst->pending_confirm = 1;
444}
445
446static inline int dst_neigh_output(struct dst_entry *dst, struct neighbour *n,
447 struct sk_buff *skb)
448{
449 const struct hh_cache *hh;
450
451 if (dst->pending_confirm) {
452 unsigned long now = jiffies;
453
454 dst->pending_confirm = 0;
455 /* avoid dirtying neighbour */
456 if (n->confirmed != now)
457 n->confirmed = now;
458 }
459
460 hh = &n->hh;
461 if ((n->nud_state & NUD_CONNECTED) && hh->hh_len)
462 return neigh_hh_output(hh, skb);
463 else
464 return n->output(n, skb);
465}
466
467static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
468{
469 struct neighbour *n = dst->ops->neigh_lookup(dst, NULL, daddr);
470 return IS_ERR(n) ? NULL : n;
471}
472
473static inline struct neighbour *dst_neigh_lookup_skb(const struct dst_entry *dst,
474 struct sk_buff *skb)
475{
476 struct neighbour *n = dst->ops->neigh_lookup(dst, skb, NULL);
477 return IS_ERR(n) ? NULL : n;
478}
479
480static inline void dst_link_failure(struct sk_buff *skb)
481{
482 struct dst_entry *dst = skb_dst(skb);
483 if (dst && dst->ops && dst->ops->link_failure)
484 dst->ops->link_failure(skb);
485}
486
487static inline void dst_set_expires(struct dst_entry *dst, int timeout)
488{
489 unsigned long expires = jiffies + timeout;
490
491 if (expires == 0)
492 expires = 1;
493
494 if (dst->expires == 0 || time_before(expires, dst->expires))
495 dst->expires = expires;
496}
497
498/* Output packet to network from transport. */
499static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
500{
501 return skb_dst(skb)->output(net, sk, skb);
502}
503
504/* Input packet from network to transport. */
505static inline int dst_input(struct sk_buff *skb)
506{
507 return skb_dst(skb)->input(skb);
508}
509
510static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
511{
512 if (dst->obsolete)
513 dst = dst->ops->check(dst, cookie);
514 return dst;
515}
516
517void dst_subsys_init(void);
518
519/* Flags for xfrm_lookup flags argument. */
520enum {
521 XFRM_LOOKUP_ICMP = 1 << 0,
522 XFRM_LOOKUP_QUEUE = 1 << 1,
523 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
524};
525
526struct flowi;
527#ifndef CONFIG_XFRM
528static inline struct dst_entry *xfrm_lookup(struct net *net,
529 struct dst_entry *dst_orig,
530 const struct flowi *fl,
531 const struct sock *sk,
532 int flags)
533{
534 return dst_orig;
535}
536
537static inline struct dst_entry *xfrm_lookup_route(struct net *net,
538 struct dst_entry *dst_orig,
539 const struct flowi *fl,
540 const struct sock *sk,
541 int flags)
542{
543 return dst_orig;
544}
545
546static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
547{
548 return NULL;
549}
550
551#else
552struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
553 const struct flowi *fl, const struct sock *sk,
554 int flags);
555
556struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
557 const struct flowi *fl, const struct sock *sk,
558 int flags);
559
560/* skb attached with this dst needs transformation if dst->xfrm is valid */
561static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
562{
563 return dst->xfrm;
564}
565#endif
566
567#endif /* _NET_DST_H */