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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/jiffies.h>
16#include <net/neighbour.h>
17#include <asm/processor.h>
18
19#define DST_GC_MIN (HZ/10)
20#define DST_GC_INC (HZ/2)
21#define DST_GC_MAX (120*HZ)
22
23/* Each dst_entry has reference count and sits in some parent list(s).
24 * When it is removed from parent list, it is "freed" (dst_free).
25 * After this it enters dead state (dst->obsolete > 0) and if its refcnt
26 * is zero, it can be destroyed immediately, otherwise it is added
27 * to gc list and garbage collector periodically checks the refcnt.
28 */
29
30struct sk_buff;
31
32struct dst_entry {
33 struct rcu_head rcu_head;
34 struct dst_entry *child;
35 struct net_device *dev;
36 struct dst_ops *ops;
37 unsigned long _metrics;
38 unsigned long expires;
39 struct dst_entry *path;
40 struct neighbour __rcu *_neighbour;
41#ifdef CONFIG_XFRM
42 struct xfrm_state *xfrm;
43#else
44 void *__pad1;
45#endif
46 int (*input)(struct sk_buff*);
47 int (*output)(struct sk_buff*);
48
49 int flags;
50#define DST_HOST 0x0001
51#define DST_NOXFRM 0x0002
52#define DST_NOPOLICY 0x0004
53#define DST_NOHASH 0x0008
54#define DST_NOCACHE 0x0010
55#define DST_NOCOUNT 0x0020
56
57 short error;
58 short obsolete;
59 unsigned short header_len; /* more space at head required */
60 unsigned short trailer_len; /* space to reserve at tail */
61#ifdef CONFIG_IP_ROUTE_CLASSID
62 __u32 tclassid;
63#else
64 __u32 __pad2;
65#endif
66
67 /*
68 * Align __refcnt to a 64 bytes alignment
69 * (L1_CACHE_SIZE would be too much)
70 */
71#ifdef CONFIG_64BIT
72 long __pad_to_align_refcnt[2];
73#endif
74 /*
75 * __refcnt wants to be on a different cache line from
76 * input/output/ops or performance tanks badly
77 */
78 atomic_t __refcnt; /* client references */
79 int __use;
80 unsigned long lastuse;
81 union {
82 struct dst_entry *next;
83 struct rtable __rcu *rt_next;
84 struct rt6_info *rt6_next;
85 struct dn_route __rcu *dn_next;
86 };
87};
88
89static inline struct neighbour *dst_get_neighbour(struct dst_entry *dst)
90{
91 return rcu_dereference(dst->_neighbour);
92}
93
94static inline struct neighbour *dst_get_neighbour_raw(struct dst_entry *dst)
95{
96 return rcu_dereference_raw(dst->_neighbour);
97}
98
99static inline void dst_set_neighbour(struct dst_entry *dst, struct neighbour *neigh)
100{
101 rcu_assign_pointer(dst->_neighbour, neigh);
102}
103
104extern u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old);
105extern const u32 dst_default_metrics[RTAX_MAX];
106
107#define DST_METRICS_READ_ONLY 0x1UL
108#define __DST_METRICS_PTR(Y) \
109 ((u32 *)((Y) & ~DST_METRICS_READ_ONLY))
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
117extern void __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
200static inline u32
201dst_feature(const struct dst_entry *dst, u32 feature)
202{
203 return dst_metric(dst, RTAX_FEATURES) & feature;
204}
205
206static inline u32 dst_mtu(const struct dst_entry *dst)
207{
208 u32 mtu = dst_metric_raw(dst, RTAX_MTU);
209
210 if (!mtu)
211 mtu = dst->ops->default_mtu(dst);
212
213 return mtu;
214}
215
216/* RTT metrics are stored in milliseconds for user ABI, but used as jiffies */
217static inline unsigned long dst_metric_rtt(const struct dst_entry *dst, int metric)
218{
219 return msecs_to_jiffies(dst_metric(dst, metric));
220}
221
222static inline void set_dst_metric_rtt(struct dst_entry *dst, int metric,
223 unsigned long rtt)
224{
225 dst_metric_set(dst, metric, jiffies_to_msecs(rtt));
226}
227
228static inline u32
229dst_allfrag(const struct dst_entry *dst)
230{
231 int ret = dst_feature(dst, RTAX_FEATURE_ALLFRAG);
232 return ret;
233}
234
235static inline int
236dst_metric_locked(const struct dst_entry *dst, int metric)
237{
238 return dst_metric(dst, RTAX_LOCK) & (1<<metric);
239}
240
241static inline void dst_hold(struct dst_entry * dst)
242{
243 /*
244 * If your kernel compilation stops here, please check
245 * __pad_to_align_refcnt declaration in struct dst_entry
246 */
247 BUILD_BUG_ON(offsetof(struct dst_entry, __refcnt) & 63);
248 atomic_inc(&dst->__refcnt);
249}
250
251static inline void dst_use(struct dst_entry *dst, unsigned long time)
252{
253 dst_hold(dst);
254 dst->__use++;
255 dst->lastuse = time;
256}
257
258static inline void dst_use_noref(struct dst_entry *dst, unsigned long time)
259{
260 dst->__use++;
261 dst->lastuse = time;
262}
263
264static inline
265struct dst_entry * dst_clone(struct dst_entry * dst)
266{
267 if (dst)
268 atomic_inc(&dst->__refcnt);
269 return dst;
270}
271
272extern void dst_release(struct dst_entry *dst);
273
274static inline void refdst_drop(unsigned long refdst)
275{
276 if (!(refdst & SKB_DST_NOREF))
277 dst_release((struct dst_entry *)(refdst & SKB_DST_PTRMASK));
278}
279
280/**
281 * skb_dst_drop - drops skb dst
282 * @skb: buffer
283 *
284 * Drops dst reference count if a reference was taken.
285 */
286static inline void skb_dst_drop(struct sk_buff *skb)
287{
288 if (skb->_skb_refdst) {
289 refdst_drop(skb->_skb_refdst);
290 skb->_skb_refdst = 0UL;
291 }
292}
293
294static inline void skb_dst_copy(struct sk_buff *nskb, const struct sk_buff *oskb)
295{
296 nskb->_skb_refdst = oskb->_skb_refdst;
297 if (!(nskb->_skb_refdst & SKB_DST_NOREF))
298 dst_clone(skb_dst(nskb));
299}
300
301/**
302 * skb_dst_force - makes sure skb dst is refcounted
303 * @skb: buffer
304 *
305 * If dst is not yet refcounted, let's do it
306 */
307static inline void skb_dst_force(struct sk_buff *skb)
308{
309 if (skb_dst_is_noref(skb)) {
310 WARN_ON(!rcu_read_lock_held());
311 skb->_skb_refdst &= ~SKB_DST_NOREF;
312 dst_clone(skb_dst(skb));
313 }
314}
315
316
317/**
318 * __skb_tunnel_rx - prepare skb for rx reinsert
319 * @skb: buffer
320 * @dev: tunnel device
321 *
322 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
323 * so make some cleanups. (no accounting done)
324 */
325static inline void __skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
326{
327 skb->dev = dev;
328 skb->rxhash = 0;
329 skb_set_queue_mapping(skb, 0);
330 skb_dst_drop(skb);
331 nf_reset(skb);
332}
333
334/**
335 * skb_tunnel_rx - prepare skb for rx reinsert
336 * @skb: buffer
337 * @dev: tunnel device
338 *
339 * After decapsulation, packet is going to re-enter (netif_rx()) our stack,
340 * so make some cleanups, and perform accounting.
341 * Note: this accounting is not SMP safe.
342 */
343static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
344{
345 /* TODO : stats should be SMP safe */
346 dev->stats.rx_packets++;
347 dev->stats.rx_bytes += skb->len;
348 __skb_tunnel_rx(skb, dev);
349}
350
351/* Children define the path of the packet through the
352 * Linux networking. Thus, destinations are stackable.
353 */
354
355static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
356{
357 struct dst_entry *child = dst_clone(skb_dst(skb)->child);
358
359 skb_dst_drop(skb);
360 return child;
361}
362
363extern int dst_discard(struct sk_buff *skb);
364extern void *dst_alloc(struct dst_ops * ops, struct net_device *dev,
365 int initial_ref, int initial_obsolete, int flags);
366extern void __dst_free(struct dst_entry * dst);
367extern struct dst_entry *dst_destroy(struct dst_entry * dst);
368
369static inline void dst_free(struct dst_entry * dst)
370{
371 if (dst->obsolete > 1)
372 return;
373 if (!atomic_read(&dst->__refcnt)) {
374 dst = dst_destroy(dst);
375 if (!dst)
376 return;
377 }
378 __dst_free(dst);
379}
380
381static inline void dst_rcu_free(struct rcu_head *head)
382{
383 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
384 dst_free(dst);
385}
386
387static inline void dst_confirm(struct dst_entry *dst)
388{
389 if (dst) {
390 struct neighbour *n;
391
392 rcu_read_lock();
393 n = dst_get_neighbour(dst);
394 neigh_confirm(n);
395 rcu_read_unlock();
396 }
397}
398
399static inline struct neighbour *dst_neigh_lookup(const struct dst_entry *dst, const void *daddr)
400{
401 return dst->ops->neigh_lookup(dst, daddr);
402}
403
404static inline void dst_link_failure(struct sk_buff *skb)
405{
406 struct dst_entry *dst = skb_dst(skb);
407 if (dst && dst->ops && dst->ops->link_failure)
408 dst->ops->link_failure(skb);
409}
410
411static inline void dst_set_expires(struct dst_entry *dst, int timeout)
412{
413 unsigned long expires = jiffies + timeout;
414
415 if (expires == 0)
416 expires = 1;
417
418 if (dst->expires == 0 || time_before(expires, dst->expires))
419 dst->expires = expires;
420}
421
422/* Output packet to network from transport. */
423static inline int dst_output(struct sk_buff *skb)
424{
425 return skb_dst(skb)->output(skb);
426}
427
428/* Input packet from network to transport. */
429static inline int dst_input(struct sk_buff *skb)
430{
431 return skb_dst(skb)->input(skb);
432}
433
434static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
435{
436 if (dst->obsolete)
437 dst = dst->ops->check(dst, cookie);
438 return dst;
439}
440
441extern void dst_init(void);
442
443/* Flags for xfrm_lookup flags argument. */
444enum {
445 XFRM_LOOKUP_ICMP = 1 << 0,
446};
447
448struct flowi;
449#ifndef CONFIG_XFRM
450static inline struct dst_entry *xfrm_lookup(struct net *net,
451 struct dst_entry *dst_orig,
452 const struct flowi *fl, struct sock *sk,
453 int flags)
454{
455 return dst_orig;
456}
457#else
458extern struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
459 const struct flowi *fl, struct sock *sk,
460 int flags);
461#endif
462
463#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 <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 recalulate 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
443INDIRECT_CALLABLE_DECLARE(int ip6_output(struct net *, struct sock *,
444 struct sk_buff *));
445INDIRECT_CALLABLE_DECLARE(int ip_output(struct net *, struct sock *,
446 struct sk_buff *));
447/* Output packet to network from transport. */
448static inline int dst_output(struct net *net, struct sock *sk, struct sk_buff *skb)
449{
450 return INDIRECT_CALL_INET(skb_dst(skb)->output,
451 ip6_output, ip_output,
452 net, sk, skb);
453}
454
455INDIRECT_CALLABLE_DECLARE(int ip6_input(struct sk_buff *));
456INDIRECT_CALLABLE_DECLARE(int ip_local_deliver(struct sk_buff *));
457/* Input packet from network to transport. */
458static inline int dst_input(struct sk_buff *skb)
459{
460 return INDIRECT_CALL_INET(skb_dst(skb)->input,
461 ip6_input, ip_local_deliver, skb);
462}
463
464INDIRECT_CALLABLE_DECLARE(struct dst_entry *ip6_dst_check(struct dst_entry *,
465 u32));
466INDIRECT_CALLABLE_DECLARE(struct dst_entry *ipv4_dst_check(struct dst_entry *,
467 u32));
468static inline struct dst_entry *dst_check(struct dst_entry *dst, u32 cookie)
469{
470 if (dst->obsolete)
471 dst = INDIRECT_CALL_INET(dst->ops->check, ip6_dst_check,
472 ipv4_dst_check, dst, cookie);
473 return dst;
474}
475
476/* Flags for xfrm_lookup flags argument. */
477enum {
478 XFRM_LOOKUP_ICMP = 1 << 0,
479 XFRM_LOOKUP_QUEUE = 1 << 1,
480 XFRM_LOOKUP_KEEP_DST_REF = 1 << 2,
481};
482
483struct flowi;
484#ifndef CONFIG_XFRM
485static inline struct dst_entry *xfrm_lookup(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 dst_entry *
495xfrm_lookup_with_ifid(struct net *net, struct dst_entry *dst_orig,
496 const struct flowi *fl, const struct sock *sk,
497 int flags, u32 if_id)
498{
499 return dst_orig;
500}
501
502static inline struct dst_entry *xfrm_lookup_route(struct net *net,
503 struct dst_entry *dst_orig,
504 const struct flowi *fl,
505 const struct sock *sk,
506 int flags)
507{
508 return dst_orig;
509}
510
511static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
512{
513 return NULL;
514}
515
516#else
517struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
518 const struct flowi *fl, const struct sock *sk,
519 int flags);
520
521struct dst_entry *xfrm_lookup_with_ifid(struct net *net,
522 struct dst_entry *dst_orig,
523 const struct flowi *fl,
524 const struct sock *sk, int flags,
525 u32 if_id);
526
527struct dst_entry *xfrm_lookup_route(struct net *net, struct dst_entry *dst_orig,
528 const struct flowi *fl, const struct sock *sk,
529 int flags);
530
531/* skb attached with this dst needs transformation if dst->xfrm is valid */
532static inline struct xfrm_state *dst_xfrm(const struct dst_entry *dst)
533{
534 return dst->xfrm;
535}
536#endif
537
538static inline void skb_dst_update_pmtu(struct sk_buff *skb, u32 mtu)
539{
540 struct dst_entry *dst = skb_dst(skb);
541
542 if (dst && dst->ops->update_pmtu)
543 dst->ops->update_pmtu(dst, NULL, skb, mtu, true);
544}
545
546/* update dst pmtu but not do neighbor confirm */
547static inline void skb_dst_update_pmtu_no_confirm(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, false);
553}
554
555struct dst_entry *dst_blackhole_check(struct dst_entry *dst, u32 cookie);
556void dst_blackhole_update_pmtu(struct dst_entry *dst, struct sock *sk,
557 struct sk_buff *skb, u32 mtu, bool confirm_neigh);
558void dst_blackhole_redirect(struct dst_entry *dst, struct sock *sk,
559 struct sk_buff *skb);
560u32 *dst_blackhole_cow_metrics(struct dst_entry *dst, unsigned long old);
561struct neighbour *dst_blackhole_neigh_lookup(const struct dst_entry *dst,
562 struct sk_buff *skb,
563 const void *daddr);
564unsigned int dst_blackhole_mtu(const struct dst_entry *dst);
565
566#endif /* _NET_DST_H */