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14#include <linux/err.h>
15#include <linux/kernel.h>
16#include <linux/netdevice.h>
17#include <net/addrconf.h>
18#include <net/dst.h>
19#include <net/xfrm.h>
20#include <net/ip.h>
21#include <net/ipv6.h>
22#include <net/ip6_route.h>
23#include <net/l3mdev.h>
24#if IS_ENABLED(CONFIG_IPV6_MIP6)
25#include <net/mip6.h>
26#endif
27
28static struct xfrm_policy_afinfo xfrm6_policy_afinfo;
29
30static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif,
31 const xfrm_address_t *saddr,
32 const xfrm_address_t *daddr)
33{
34 struct flowi6 fl6;
35 struct dst_entry *dst;
36 int err;
37
38 memset(&fl6, 0, sizeof(fl6));
39 fl6.flowi6_oif = oif;
40 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
41 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
42 if (saddr)
43 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));
44
45 dst = ip6_route_output(net, NULL, &fl6);
46
47 err = dst->error;
48 if (dst->error) {
49 dst_release(dst);
50 dst = ERR_PTR(err);
51 }
52
53 return dst;
54}
55
56static int xfrm6_get_saddr(struct net *net, int oif,
57 xfrm_address_t *saddr, xfrm_address_t *daddr)
58{
59 struct dst_entry *dst;
60 struct net_device *dev;
61
62 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr);
63 if (IS_ERR(dst))
64 return -EHOSTUNREACH;
65
66 dev = ip6_dst_idev(dst)->dev;
67 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
68 dst_release(dst);
69 return 0;
70}
71
72static int xfrm6_get_tos(const struct flowi *fl)
73{
74 return 0;
75}
76
77static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
78 int nfheader_len)
79{
80 if (dst->ops->family == AF_INET6) {
81 struct rt6_info *rt = (struct rt6_info *)dst;
82 path->path_cookie = rt6_get_cookie(rt);
83 }
84
85 path->u.rt6.rt6i_nfheader_len = nfheader_len;
86
87 return 0;
88}
89
90static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
91 const struct flowi *fl)
92{
93 struct rt6_info *rt = (struct rt6_info *)xdst->route;
94
95 xdst->u.dst.dev = dev;
96 dev_hold(dev);
97
98 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
99 if (!xdst->u.rt6.rt6i_idev) {
100 dev_put(dev);
101 return -ENODEV;
102 }
103
104
105
106 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
107 RTF_LOCAL);
108 xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
109 xdst->u.rt6.rt6i_node = rt->rt6i_node;
110 xdst->route_cookie = rt6_get_cookie(rt);
111 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
112 xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
113 xdst->u.rt6.rt6i_src = rt->rt6i_src;
114
115 return 0;
116}
117
118static inline void
119_decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
120{
121 struct flowi6 *fl6 = &fl->u.ip6;
122 int onlyproto = 0;
123 const struct ipv6hdr *hdr = ipv6_hdr(skb);
124 u16 offset = sizeof(*hdr);
125 struct ipv6_opt_hdr *exthdr;
126 const unsigned char *nh = skb_network_header(skb);
127 u16 nhoff = IP6CB(skb)->nhoff;
128 int oif = 0;
129 u8 nexthdr;
130
131 if (!nhoff)
132 nhoff = offsetof(struct ipv6hdr, nexthdr);
133
134 nexthdr = nh[nhoff];
135
136 if (skb_dst(skb))
137 oif = l3mdev_fib_oif(skb_dst(skb)->dev);
138
139 memset(fl6, 0, sizeof(struct flowi6));
140 fl6->flowi6_mark = skb->mark;
141 fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
142
143 fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
144 fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
145
146 while (nh + offset + 1 < skb->data ||
147 pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
148 nh = skb_network_header(skb);
149 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
150
151 switch (nexthdr) {
152 case NEXTHDR_FRAGMENT:
153 onlyproto = 1;
154 case NEXTHDR_ROUTING:
155 case NEXTHDR_HOP:
156 case NEXTHDR_DEST:
157 offset += ipv6_optlen(exthdr);
158 nexthdr = exthdr->nexthdr;
159 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
160 break;
161
162 case IPPROTO_UDP:
163 case IPPROTO_UDPLITE:
164 case IPPROTO_TCP:
165 case IPPROTO_SCTP:
166 case IPPROTO_DCCP:
167 if (!onlyproto && (nh + offset + 4 < skb->data ||
168 pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
169 __be16 *ports;
170
171 nh = skb_network_header(skb);
172 ports = (__be16 *)(nh + offset);
173 fl6->fl6_sport = ports[!!reverse];
174 fl6->fl6_dport = ports[!reverse];
175 }
176 fl6->flowi6_proto = nexthdr;
177 return;
178
179 case IPPROTO_ICMPV6:
180 if (!onlyproto && (nh + offset + 2 < skb->data ||
181 pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
182 u8 *icmp;
183
184 nh = skb_network_header(skb);
185 icmp = (u8 *)(nh + offset);
186 fl6->fl6_icmp_type = icmp[0];
187 fl6->fl6_icmp_code = icmp[1];
188 }
189 fl6->flowi6_proto = nexthdr;
190 return;
191
192#if IS_ENABLED(CONFIG_IPV6_MIP6)
193 case IPPROTO_MH:
194 offset += ipv6_optlen(exthdr);
195 if (!onlyproto && (nh + offset + 3 < skb->data ||
196 pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
197 struct ip6_mh *mh;
198
199 nh = skb_network_header(skb);
200 mh = (struct ip6_mh *)(nh + offset);
201 fl6->fl6_mh_type = mh->ip6mh_type;
202 }
203 fl6->flowi6_proto = nexthdr;
204 return;
205#endif
206
207
208 case IPPROTO_AH:
209 case IPPROTO_ESP:
210 case IPPROTO_COMP:
211 default:
212 fl6->fl6_ipsec_spi = 0;
213 fl6->flowi6_proto = nexthdr;
214 return;
215 }
216 }
217}
218
219static inline int xfrm6_garbage_collect(struct dst_ops *ops)
220{
221 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);
222
223 xfrm6_policy_afinfo.garbage_collect(net);
224 return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
225}
226
227static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
228 struct sk_buff *skb, u32 mtu)
229{
230 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
231 struct dst_entry *path = xdst->route;
232
233 path->ops->update_pmtu(path, sk, skb, mtu);
234}
235
236static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
237 struct sk_buff *skb)
238{
239 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
240 struct dst_entry *path = xdst->route;
241
242 path->ops->redirect(path, sk, skb);
243}
244
245static void xfrm6_dst_destroy(struct dst_entry *dst)
246{
247 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
248
249 if (likely(xdst->u.rt6.rt6i_idev))
250 in6_dev_put(xdst->u.rt6.rt6i_idev);
251 dst_destroy_metrics_generic(dst);
252 xfrm_dst_destroy(xdst);
253}
254
255static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
256 int unregister)
257{
258 struct xfrm_dst *xdst;
259
260 if (!unregister)
261 return;
262
263 xdst = (struct xfrm_dst *)dst;
264 if (xdst->u.rt6.rt6i_idev->dev == dev) {
265 struct inet6_dev *loopback_idev =
266 in6_dev_get(dev_net(dev)->loopback_dev);
267 BUG_ON(!loopback_idev);
268
269 do {
270 in6_dev_put(xdst->u.rt6.rt6i_idev);
271 xdst->u.rt6.rt6i_idev = loopback_idev;
272 in6_dev_hold(loopback_idev);
273 xdst = (struct xfrm_dst *)xdst->u.dst.child;
274 } while (xdst->u.dst.xfrm);
275
276 __in6_dev_put(loopback_idev);
277 }
278
279 xfrm_dst_ifdown(dst, dev);
280}
281
282static struct dst_ops xfrm6_dst_ops_template = {
283 .family = AF_INET6,
284 .gc = xfrm6_garbage_collect,
285 .update_pmtu = xfrm6_update_pmtu,
286 .redirect = xfrm6_redirect,
287 .cow_metrics = dst_cow_metrics_generic,
288 .destroy = xfrm6_dst_destroy,
289 .ifdown = xfrm6_dst_ifdown,
290 .local_out = __ip6_local_out,
291 .gc_thresh = INT_MAX,
292};
293
294static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
295 .family = AF_INET6,
296 .dst_ops = &xfrm6_dst_ops_template,
297 .dst_lookup = xfrm6_dst_lookup,
298 .get_saddr = xfrm6_get_saddr,
299 .decode_session = _decode_session6,
300 .get_tos = xfrm6_get_tos,
301 .init_path = xfrm6_init_path,
302 .fill_dst = xfrm6_fill_dst,
303 .blackhole_route = ip6_blackhole_route,
304};
305
306static int __init xfrm6_policy_init(void)
307{
308 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
309}
310
311static void xfrm6_policy_fini(void)
312{
313 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
314}
315
316#ifdef CONFIG_SYSCTL
317static struct ctl_table xfrm6_policy_table[] = {
318 {
319 .procname = "xfrm6_gc_thresh",
320 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
321 .maxlen = sizeof(int),
322 .mode = 0644,
323 .proc_handler = proc_dointvec,
324 },
325 { }
326};
327
328static int __net_init xfrm6_net_sysctl_init(struct net *net)
329{
330 struct ctl_table *table;
331 struct ctl_table_header *hdr;
332
333 table = xfrm6_policy_table;
334 if (!net_eq(net, &init_net)) {
335 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
336 if (!table)
337 goto err_alloc;
338
339 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
340 }
341
342 hdr = register_net_sysctl(net, "net/ipv6", table);
343 if (!hdr)
344 goto err_reg;
345
346 net->ipv6.sysctl.xfrm6_hdr = hdr;
347 return 0;
348
349err_reg:
350 if (!net_eq(net, &init_net))
351 kfree(table);
352err_alloc:
353 return -ENOMEM;
354}
355
356static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
357{
358 struct ctl_table *table;
359
360 if (!net->ipv6.sysctl.xfrm6_hdr)
361 return;
362
363 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
364 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
365 if (!net_eq(net, &init_net))
366 kfree(table);
367}
368#else
369static int inline xfrm6_net_sysctl_init(struct net *net)
370{
371 return 0;
372}
373
374static void inline xfrm6_net_sysctl_exit(struct net *net)
375{
376}
377#endif
378
379static int __net_init xfrm6_net_init(struct net *net)
380{
381 int ret;
382
383 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
384 sizeof(xfrm6_dst_ops_template));
385 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops);
386 if (ret)
387 return ret;
388
389 ret = xfrm6_net_sysctl_init(net);
390 if (ret)
391 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
392
393 return ret;
394}
395
396static void __net_exit xfrm6_net_exit(struct net *net)
397{
398 xfrm6_net_sysctl_exit(net);
399 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
400}
401
402static struct pernet_operations xfrm6_net_ops = {
403 .init = xfrm6_net_init,
404 .exit = xfrm6_net_exit,
405};
406
407int __init xfrm6_init(void)
408{
409 int ret;
410
411 ret = xfrm6_policy_init();
412 if (ret)
413 goto out;
414 ret = xfrm6_state_init();
415 if (ret)
416 goto out_policy;
417
418 ret = xfrm6_protocol_init();
419 if (ret)
420 goto out_state;
421
422 register_pernet_subsys(&xfrm6_net_ops);
423out:
424 return ret;
425out_state:
426 xfrm6_state_fini();
427out_policy:
428 xfrm6_policy_fini();
429 goto out;
430}
431
432void xfrm6_fini(void)
433{
434 unregister_pernet_subsys(&xfrm6_net_ops);
435 xfrm6_protocol_fini();
436 xfrm6_policy_fini();
437 xfrm6_state_fini();
438}
439
