This source file includes following definitions.
- dst_discard_out
- dst_init
- dst_alloc
- dst_destroy
- dst_destroy_rcu
- dst_dev_put
- dst_release
- dst_release_immediate
- dst_cow_metrics_generic
- __dst_destroy_metrics_generic
- dst_md_discard_out
- dst_md_discard
- __metadata_dst_init
- metadata_dst_alloc
- metadata_dst_free
- metadata_dst_alloc_percpu
- metadata_dst_free_percpu
1
2
3
4
5
6
7
8
9 #include <linux/bitops.h>
10 #include <linux/errno.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/workqueue.h>
14 #include <linux/mm.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/netdevice.h>
18 #include <linux/skbuff.h>
19 #include <linux/string.h>
20 #include <linux/types.h>
21 #include <net/net_namespace.h>
22 #include <linux/sched.h>
23 #include <linux/prefetch.h>
24 #include <net/lwtunnel.h>
25 #include <net/xfrm.h>
26
27 #include <net/dst.h>
28 #include <net/dst_metadata.h>
29
30 int dst_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
31 {
32 kfree_skb(skb);
33 return 0;
34 }
35 EXPORT_SYMBOL(dst_discard_out);
36
37 const struct dst_metrics dst_default_metrics = {
38
39
40
41
42
43 .refcnt = REFCOUNT_INIT(1),
44 };
45 EXPORT_SYMBOL(dst_default_metrics);
46
47 void dst_init(struct dst_entry *dst, struct dst_ops *ops,
48 struct net_device *dev, int initial_ref, int initial_obsolete,
49 unsigned short flags)
50 {
51 dst->dev = dev;
52 if (dev)
53 dev_hold(dev);
54 dst->ops = ops;
55 dst_init_metrics(dst, dst_default_metrics.metrics, true);
56 dst->expires = 0UL;
57 #ifdef CONFIG_XFRM
58 dst->xfrm = NULL;
59 #endif
60 dst->input = dst_discard;
61 dst->output = dst_discard_out;
62 dst->error = 0;
63 dst->obsolete = initial_obsolete;
64 dst->header_len = 0;
65 dst->trailer_len = 0;
66 #ifdef CONFIG_IP_ROUTE_CLASSID
67 dst->tclassid = 0;
68 #endif
69 dst->lwtstate = NULL;
70 atomic_set(&dst->__refcnt, initial_ref);
71 dst->__use = 0;
72 dst->lastuse = jiffies;
73 dst->flags = flags;
74 if (!(flags & DST_NOCOUNT))
75 dst_entries_add(ops, 1);
76 }
77 EXPORT_SYMBOL(dst_init);
78
79 void *dst_alloc(struct dst_ops *ops, struct net_device *dev,
80 int initial_ref, int initial_obsolete, unsigned short flags)
81 {
82 struct dst_entry *dst;
83
84 if (ops->gc && dst_entries_get_fast(ops) > ops->gc_thresh) {
85 if (ops->gc(ops)) {
86 printk_ratelimited(KERN_NOTICE "Route cache is full: "
87 "consider increasing sysctl "
88 "net.ipv[4|6].route.max_size.\n");
89 return NULL;
90 }
91 }
92
93 dst = kmem_cache_alloc(ops->kmem_cachep, GFP_ATOMIC);
94 if (!dst)
95 return NULL;
96
97 dst_init(dst, ops, dev, initial_ref, initial_obsolete, flags);
98
99 return dst;
100 }
101 EXPORT_SYMBOL(dst_alloc);
102
103 struct dst_entry *dst_destroy(struct dst_entry * dst)
104 {
105 struct dst_entry *child = NULL;
106
107 smp_rmb();
108
109 #ifdef CONFIG_XFRM
110 if (dst->xfrm) {
111 struct xfrm_dst *xdst = (struct xfrm_dst *) dst;
112
113 child = xdst->child;
114 }
115 #endif
116 if (!(dst->flags & DST_NOCOUNT))
117 dst_entries_add(dst->ops, -1);
118
119 if (dst->ops->destroy)
120 dst->ops->destroy(dst);
121 if (dst->dev)
122 dev_put(dst->dev);
123
124 lwtstate_put(dst->lwtstate);
125
126 if (dst->flags & DST_METADATA)
127 metadata_dst_free((struct metadata_dst *)dst);
128 else
129 kmem_cache_free(dst->ops->kmem_cachep, dst);
130
131 dst = child;
132 if (dst)
133 dst_release_immediate(dst);
134 return NULL;
135 }
136 EXPORT_SYMBOL(dst_destroy);
137
138 static void dst_destroy_rcu(struct rcu_head *head)
139 {
140 struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head);
141
142 dst = dst_destroy(dst);
143 }
144
145
146
147
148
149
150
151
152
153
154 void dst_dev_put(struct dst_entry *dst)
155 {
156 struct net_device *dev = dst->dev;
157
158 dst->obsolete = DST_OBSOLETE_DEAD;
159 if (dst->ops->ifdown)
160 dst->ops->ifdown(dst, dev, true);
161 dst->input = dst_discard;
162 dst->output = dst_discard_out;
163 dst->dev = blackhole_netdev;
164 dev_hold(dst->dev);
165 dev_put(dev);
166 }
167 EXPORT_SYMBOL(dst_dev_put);
168
169 void dst_release(struct dst_entry *dst)
170 {
171 if (dst) {
172 int newrefcnt;
173
174 newrefcnt = atomic_dec_return(&dst->__refcnt);
175 if (WARN_ONCE(newrefcnt < 0, "dst_release underflow"))
176 net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
177 __func__, dst, newrefcnt);
178 if (!newrefcnt)
179 call_rcu(&dst->rcu_head, dst_destroy_rcu);
180 }
181 }
182 EXPORT_SYMBOL(dst_release);
183
184 void dst_release_immediate(struct dst_entry *dst)
185 {
186 if (dst) {
187 int newrefcnt;
188
189 newrefcnt = atomic_dec_return(&dst->__refcnt);
190 if (WARN_ONCE(newrefcnt < 0, "dst_release_immediate underflow"))
191 net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
192 __func__, dst, newrefcnt);
193 if (!newrefcnt)
194 dst_destroy(dst);
195 }
196 }
197 EXPORT_SYMBOL(dst_release_immediate);
198
199 u32 *dst_cow_metrics_generic(struct dst_entry *dst, unsigned long old)
200 {
201 struct dst_metrics *p = kmalloc(sizeof(*p), GFP_ATOMIC);
202
203 if (p) {
204 struct dst_metrics *old_p = (struct dst_metrics *)__DST_METRICS_PTR(old);
205 unsigned long prev, new;
206
207 refcount_set(&p->refcnt, 1);
208 memcpy(p->metrics, old_p->metrics, sizeof(p->metrics));
209
210 new = (unsigned long) p;
211 prev = cmpxchg(&dst->_metrics, old, new);
212
213 if (prev != old) {
214 kfree(p);
215 p = (struct dst_metrics *)__DST_METRICS_PTR(prev);
216 if (prev & DST_METRICS_READ_ONLY)
217 p = NULL;
218 } else if (prev & DST_METRICS_REFCOUNTED) {
219 if (refcount_dec_and_test(&old_p->refcnt))
220 kfree(old_p);
221 }
222 }
223 BUILD_BUG_ON(offsetof(struct dst_metrics, metrics) != 0);
224 return (u32 *)p;
225 }
226 EXPORT_SYMBOL(dst_cow_metrics_generic);
227
228
229 void __dst_destroy_metrics_generic(struct dst_entry *dst, unsigned long old)
230 {
231 unsigned long prev, new;
232
233 new = ((unsigned long) &dst_default_metrics) | DST_METRICS_READ_ONLY;
234 prev = cmpxchg(&dst->_metrics, old, new);
235 if (prev == old)
236 kfree(__DST_METRICS_PTR(old));
237 }
238 EXPORT_SYMBOL(__dst_destroy_metrics_generic);
239
240 static struct dst_ops md_dst_ops = {
241 .family = AF_UNSPEC,
242 };
243
244 static int dst_md_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
245 {
246 WARN_ONCE(1, "Attempting to call output on metadata dst\n");
247 kfree_skb(skb);
248 return 0;
249 }
250
251 static int dst_md_discard(struct sk_buff *skb)
252 {
253 WARN_ONCE(1, "Attempting to call input on metadata dst\n");
254 kfree_skb(skb);
255 return 0;
256 }
257
258 static void __metadata_dst_init(struct metadata_dst *md_dst,
259 enum metadata_type type, u8 optslen)
260
261 {
262 struct dst_entry *dst;
263
264 dst = &md_dst->dst;
265 dst_init(dst, &md_dst_ops, NULL, 1, DST_OBSOLETE_NONE,
266 DST_METADATA | DST_NOCOUNT);
267
268 dst->input = dst_md_discard;
269 dst->output = dst_md_discard_out;
270
271 memset(dst + 1, 0, sizeof(*md_dst) + optslen - sizeof(*dst));
272 md_dst->type = type;
273 }
274
275 struct metadata_dst *metadata_dst_alloc(u8 optslen, enum metadata_type type,
276 gfp_t flags)
277 {
278 struct metadata_dst *md_dst;
279
280 md_dst = kmalloc(sizeof(*md_dst) + optslen, flags);
281 if (!md_dst)
282 return NULL;
283
284 __metadata_dst_init(md_dst, type, optslen);
285
286 return md_dst;
287 }
288 EXPORT_SYMBOL_GPL(metadata_dst_alloc);
289
290 void metadata_dst_free(struct metadata_dst *md_dst)
291 {
292 #ifdef CONFIG_DST_CACHE
293 if (md_dst->type == METADATA_IP_TUNNEL)
294 dst_cache_destroy(&md_dst->u.tun_info.dst_cache);
295 #endif
296 kfree(md_dst);
297 }
298 EXPORT_SYMBOL_GPL(metadata_dst_free);
299
300 struct metadata_dst __percpu *
301 metadata_dst_alloc_percpu(u8 optslen, enum metadata_type type, gfp_t flags)
302 {
303 int cpu;
304 struct metadata_dst __percpu *md_dst;
305
306 md_dst = __alloc_percpu_gfp(sizeof(struct metadata_dst) + optslen,
307 __alignof__(struct metadata_dst), flags);
308 if (!md_dst)
309 return NULL;
310
311 for_each_possible_cpu(cpu)
312 __metadata_dst_init(per_cpu_ptr(md_dst, cpu), type, optslen);
313
314 return md_dst;
315 }
316 EXPORT_SYMBOL_GPL(metadata_dst_alloc_percpu);
317
318 void metadata_dst_free_percpu(struct metadata_dst __percpu *md_dst)
319 {
320 #ifdef CONFIG_DST_CACHE
321 int cpu;
322
323 for_each_possible_cpu(cpu) {
324 struct metadata_dst *one_md_dst = per_cpu_ptr(md_dst, cpu);
325
326 if (one_md_dst->type == METADATA_IP_TUNNEL)
327 dst_cache_destroy(&one_md_dst->u.tun_info.dst_cache);
328 }
329 #endif
330 free_percpu(md_dst);
331 }
332 EXPORT_SYMBOL_GPL(metadata_dst_free_percpu);