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15#include <linux/err.h>
16#include <linux/kernel.h>
17#include <linux/netdevice.h>
18#include <net/addrconf.h>
19#include <net/dst.h>
20#include <net/xfrm.h>
21#include <net/ip.h>
22#include <net/ipv6.h>
23#include <net/ip6_route.h>
24#include <net/l3mdev.h>
25#if IS_ENABLED(CONFIG_IPV6_MIP6)
26#include <net/mip6.h>
27#endif
28
29static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif,
30 const xfrm_address_t *saddr,
31 const xfrm_address_t *daddr,
32 u32 mark)
33{
34 struct flowi6 fl6;
35 struct dst_entry *dst;
36 int err;
37
38 memset(&fl6, 0, sizeof(fl6));
39 fl6.flowi6_oif = l3mdev_master_ifindex_by_index(net, oif);
40 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
41 fl6.flowi6_mark = mark;
42 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
43 if (saddr)
44 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));
45
46 dst = ip6_route_output(net, NULL, &fl6);
47
48 err = dst->error;
49 if (dst->error) {
50 dst_release(dst);
51 dst = ERR_PTR(err);
52 }
53
54 return dst;
55}
56
57static int xfrm6_get_saddr(struct net *net, int oif,
58 xfrm_address_t *saddr, xfrm_address_t *daddr,
59 u32 mark)
60{
61 struct dst_entry *dst;
62 struct net_device *dev;
63
64 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark);
65 if (IS_ERR(dst))
66 return -EHOSTUNREACH;
67
68 dev = ip6_dst_idev(dst)->dev;
69 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
70 dst_release(dst);
71 return 0;
72}
73
74static int xfrm6_get_tos(const struct flowi *fl)
75{
76 return 0;
77}
78
79static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
80 int nfheader_len)
81{
82 if (dst->ops->family == AF_INET6) {
83 struct rt6_info *rt = (struct rt6_info *)dst;
84 path->path_cookie = rt6_get_cookie(rt);
85 }
86
87 path->u.rt6.rt6i_nfheader_len = nfheader_len;
88
89 return 0;
90}
91
92static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
93 const struct flowi *fl)
94{
95 struct rt6_info *rt = (struct rt6_info *)xdst->route;
96
97 xdst->u.dst.dev = dev;
98 dev_hold(dev);
99
100 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
101 if (!xdst->u.rt6.rt6i_idev) {
102 dev_put(dev);
103 return -ENODEV;
104 }
105
106
107
108 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
109 RTF_LOCAL);
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 INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached);
115 rt6_uncached_list_add(&xdst->u.rt6);
116 atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache);
117
118 return 0;
119}
120
121static inline void
122_decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
123{
124 struct flowi6 *fl6 = &fl->u.ip6;
125 int onlyproto = 0;
126 const struct ipv6hdr *hdr = ipv6_hdr(skb);
127 u32 offset = sizeof(*hdr);
128 struct ipv6_opt_hdr *exthdr;
129 const unsigned char *nh = skb_network_header(skb);
130 u16 nhoff = IP6CB(skb)->nhoff;
131 int oif = 0;
132 u8 nexthdr;
133
134 if (!nhoff)
135 nhoff = offsetof(struct ipv6hdr, nexthdr);
136
137 nexthdr = nh[nhoff];
138
139 if (skb_dst(skb))
140 oif = skb_dst(skb)->dev->ifindex;
141
142 memset(fl6, 0, sizeof(struct flowi6));
143 fl6->flowi6_mark = skb->mark;
144 fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
145
146 fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
147 fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
148
149 while (nh + offset + sizeof(*exthdr) < skb->data ||
150 pskb_may_pull(skb, nh + offset + sizeof(*exthdr) - skb->data)) {
151 nh = skb_network_header(skb);
152 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
153
154 switch (nexthdr) {
155 case NEXTHDR_FRAGMENT:
156 onlyproto = 1;
157
158 case NEXTHDR_ROUTING:
159 case NEXTHDR_HOP:
160 case NEXTHDR_DEST:
161 offset += ipv6_optlen(exthdr);
162 nexthdr = exthdr->nexthdr;
163 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
164 break;
165
166 case IPPROTO_UDP:
167 case IPPROTO_UDPLITE:
168 case IPPROTO_TCP:
169 case IPPROTO_SCTP:
170 case IPPROTO_DCCP:
171 if (!onlyproto && (nh + offset + 4 < skb->data ||
172 pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
173 __be16 *ports;
174
175 nh = skb_network_header(skb);
176 ports = (__be16 *)(nh + offset);
177 fl6->fl6_sport = ports[!!reverse];
178 fl6->fl6_dport = ports[!reverse];
179 }
180 fl6->flowi6_proto = nexthdr;
181 return;
182
183 case IPPROTO_ICMPV6:
184 if (!onlyproto && (nh + offset + 2 < skb->data ||
185 pskb_may_pull(skb, nh + offset + 2 - skb->data))) {
186 u8 *icmp;
187
188 nh = skb_network_header(skb);
189 icmp = (u8 *)(nh + offset);
190 fl6->fl6_icmp_type = icmp[0];
191 fl6->fl6_icmp_code = icmp[1];
192 }
193 fl6->flowi6_proto = nexthdr;
194 return;
195
196#if IS_ENABLED(CONFIG_IPV6_MIP6)
197 case IPPROTO_MH:
198 offset += ipv6_optlen(exthdr);
199 if (!onlyproto && (nh + offset + 3 < skb->data ||
200 pskb_may_pull(skb, nh + offset + 3 - skb->data))) {
201 struct ip6_mh *mh;
202
203 nh = skb_network_header(skb);
204 mh = (struct ip6_mh *)(nh + offset);
205 fl6->fl6_mh_type = mh->ip6mh_type;
206 }
207 fl6->flowi6_proto = nexthdr;
208 return;
209#endif
210
211
212 case IPPROTO_AH:
213 case IPPROTO_ESP:
214 case IPPROTO_COMP:
215 default:
216 fl6->fl6_ipsec_spi = 0;
217 fl6->flowi6_proto = nexthdr;
218 return;
219 }
220 }
221}
222
223static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
224 struct sk_buff *skb, u32 mtu)
225{
226 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
227 struct dst_entry *path = xdst->route;
228
229 path->ops->update_pmtu(path, sk, skb, mtu);
230}
231
232static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
233 struct sk_buff *skb)
234{
235 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
236 struct dst_entry *path = xdst->route;
237
238 path->ops->redirect(path, sk, skb);
239}
240
241static void xfrm6_dst_destroy(struct dst_entry *dst)
242{
243 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
244
245 if (likely(xdst->u.rt6.rt6i_idev))
246 in6_dev_put(xdst->u.rt6.rt6i_idev);
247 dst_destroy_metrics_generic(dst);
248 if (xdst->u.rt6.rt6i_uncached_list)
249 rt6_uncached_list_del(&xdst->u.rt6);
250 xfrm_dst_destroy(xdst);
251}
252
253static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
254 int unregister)
255{
256 struct xfrm_dst *xdst;
257
258 if (!unregister)
259 return;
260
261 xdst = (struct xfrm_dst *)dst;
262 if (xdst->u.rt6.rt6i_idev->dev == dev) {
263 struct inet6_dev *loopback_idev =
264 in6_dev_get(dev_net(dev)->loopback_dev);
265 BUG_ON(!loopback_idev);
266
267 do {
268 in6_dev_put(xdst->u.rt6.rt6i_idev);
269 xdst->u.rt6.rt6i_idev = loopback_idev;
270 in6_dev_hold(loopback_idev);
271 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst);
272 } while (xdst->u.dst.xfrm);
273
274 __in6_dev_put(loopback_idev);
275 }
276
277 xfrm_dst_ifdown(dst, dev);
278}
279
280static struct dst_ops xfrm6_dst_ops_template = {
281 .family = AF_INET6,
282 .update_pmtu = xfrm6_update_pmtu,
283 .redirect = xfrm6_redirect,
284 .cow_metrics = dst_cow_metrics_generic,
285 .destroy = xfrm6_dst_destroy,
286 .ifdown = xfrm6_dst_ifdown,
287 .local_out = __ip6_local_out,
288 .gc_thresh = 32768,
289};
290
291static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
292 .dst_ops = &xfrm6_dst_ops_template,
293 .dst_lookup = xfrm6_dst_lookup,
294 .get_saddr = xfrm6_get_saddr,
295 .decode_session = _decode_session6,
296 .get_tos = xfrm6_get_tos,
297 .init_path = xfrm6_init_path,
298 .fill_dst = xfrm6_fill_dst,
299 .blackhole_route = ip6_blackhole_route,
300};
301
302static int __init xfrm6_policy_init(void)
303{
304 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6);
305}
306
307static void xfrm6_policy_fini(void)
308{
309 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
310}
311
312#ifdef CONFIG_SYSCTL
313static struct ctl_table xfrm6_policy_table[] = {
314 {
315 .procname = "xfrm6_gc_thresh",
316 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
317 .maxlen = sizeof(int),
318 .mode = 0644,
319 .proc_handler = proc_dointvec,
320 },
321 { }
322};
323
324static int __net_init xfrm6_net_sysctl_init(struct net *net)
325{
326 struct ctl_table *table;
327 struct ctl_table_header *hdr;
328
329 table = xfrm6_policy_table;
330 if (!net_eq(net, &init_net)) {
331 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
332 if (!table)
333 goto err_alloc;
334
335 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
336 }
337
338 hdr = register_net_sysctl(net, "net/ipv6", table);
339 if (!hdr)
340 goto err_reg;
341
342 net->ipv6.sysctl.xfrm6_hdr = hdr;
343 return 0;
344
345err_reg:
346 if (!net_eq(net, &init_net))
347 kfree(table);
348err_alloc:
349 return -ENOMEM;
350}
351
352static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
353{
354 struct ctl_table *table;
355
356 if (!net->ipv6.sysctl.xfrm6_hdr)
357 return;
358
359 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
360 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
361 if (!net_eq(net, &init_net))
362 kfree(table);
363}
364#else
365static inline int xfrm6_net_sysctl_init(struct net *net)
366{
367 return 0;
368}
369
370static inline void xfrm6_net_sysctl_exit(struct net *net)
371{
372}
373#endif
374
375static int __net_init xfrm6_net_init(struct net *net)
376{
377 int ret;
378
379 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
380 sizeof(xfrm6_dst_ops_template));
381 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops);
382 if (ret)
383 return ret;
384
385 ret = xfrm6_net_sysctl_init(net);
386 if (ret)
387 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
388
389 return ret;
390}
391
392static void __net_exit xfrm6_net_exit(struct net *net)
393{
394 xfrm6_net_sysctl_exit(net);
395 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
396}
397
398static struct pernet_operations xfrm6_net_ops = {
399 .init = xfrm6_net_init,
400 .exit = xfrm6_net_exit,
401};
402
403int __init xfrm6_init(void)
404{
405 int ret;
406
407 ret = xfrm6_policy_init();
408 if (ret)
409 goto out;
410 ret = xfrm6_state_init();
411 if (ret)
412 goto out_policy;
413
414 ret = xfrm6_protocol_init();
415 if (ret)
416 goto out_state;
417
418 register_pernet_subsys(&xfrm6_net_ops);
419out:
420 return ret;
421out_state:
422 xfrm6_state_fini();
423out_policy:
424 xfrm6_policy_fini();
425 goto out;
426}
427
428void xfrm6_fini(void)
429{
430 unregister_pernet_subsys(&xfrm6_net_ops);
431 xfrm6_protocol_fini();
432 xfrm6_policy_fini();
433 xfrm6_state_fini();
434}
435
