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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#if IS_ENABLED(CONFIG_IPV6_MIP6)
24#include <net/mip6.h>
25#endif
26
27static struct xfrm_policy_afinfo xfrm6_policy_afinfo;
28
29static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos,
30 const xfrm_address_t *saddr,
31 const xfrm_address_t *daddr)
32{
33 struct flowi6 fl6;
34 struct dst_entry *dst;
35 int err;
36
37 memset(&fl6, 0, sizeof(fl6));
38 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
39 if (saddr)
40 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));
41
42 dst = ip6_route_output(net, NULL, &fl6);
43
44 err = dst->error;
45 if (dst->error) {
46 dst_release(dst);
47 dst = ERR_PTR(err);
48 }
49
50 return dst;
51}
52
53static int xfrm6_get_saddr(struct net *net,
54 xfrm_address_t *saddr, xfrm_address_t *daddr)
55{
56 struct dst_entry *dst;
57 struct net_device *dev;
58
59 dst = xfrm6_dst_lookup(net, 0, NULL, daddr);
60 if (IS_ERR(dst))
61 return -EHOSTUNREACH;
62
63 dev = ip6_dst_idev(dst)->dev;
64 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
65 dst_release(dst);
66 return 0;
67}
68
69static int xfrm6_get_tos(const struct flowi *fl)
70{
71 return 0;
72}
73
74static void xfrm6_init_dst(struct net *net, struct xfrm_dst *xdst)
75{
76 struct rt6_info *rt = (struct rt6_info *)xdst;
77
78 rt6_init_peer(rt, net->ipv6.peers);
79}
80
81static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
82 int nfheader_len)
83{
84 if (dst->ops->family == AF_INET6) {
85 struct rt6_info *rt = (struct rt6_info *)dst;
86 if (rt->rt6i_node)
87 path->path_cookie = rt->rt6i_node->fn_sernum;
88 }
89
90 path->u.rt6.rt6i_nfheader_len = nfheader_len;
91
92 return 0;
93}
94
95static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
96 const struct flowi *fl)
97{
98 struct rt6_info *rt = (struct rt6_info *)xdst->route;
99
100 xdst->u.dst.dev = dev;
101 dev_hold(dev);
102
103 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
104 if (!xdst->u.rt6.rt6i_idev) {
105 dev_put(dev);
106 return -ENODEV;
107 }
108
109 rt6_transfer_peer(&xdst->u.rt6, rt);
110
111
112
113 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
114 RTF_LOCAL);
115 xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
116 xdst->u.rt6.rt6i_node = rt->rt6i_node;
117 if (rt->rt6i_node)
118 xdst->route_cookie = rt->rt6i_node->fn_sernum;
119 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
120 xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
121 xdst->u.rt6.rt6i_src = rt->rt6i_src;
122
123 return 0;
124}
125
126static inline void
127_decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
128{
129 struct flowi6 *fl6 = &fl->u.ip6;
130 int onlyproto = 0;
131 const struct ipv6hdr *hdr = ipv6_hdr(skb);
132 u16 offset = sizeof(*hdr);
133 struct ipv6_opt_hdr *exthdr;
134 const unsigned char *nh = skb_network_header(skb);
135 u16 nhoff = IP6CB(skb)->nhoff;
136 int oif = 0;
137 u8 nexthdr;
138
139 if (!nhoff)
140 nhoff = offsetof(struct ipv6hdr, nexthdr);
141
142 nexthdr = nh[nhoff];
143
144 if (skb_dst(skb))
145 oif = skb_dst(skb)->dev->ifindex;
146
147 memset(fl6, 0, sizeof(struct flowi6));
148 fl6->flowi6_mark = skb->mark;
149 fl6->flowi6_oif = reverse ? skb->skb_iif : oif;
150
151 fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
152 fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
153
154 while (nh + offset + 1 < skb->data ||
155 pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
156 nh = skb_network_header(skb);
157 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
158
159 switch (nexthdr) {
160 case NEXTHDR_FRAGMENT:
161 onlyproto = 1;
162 case NEXTHDR_ROUTING:
163 case NEXTHDR_HOP:
164 case NEXTHDR_DEST:
165 offset += ipv6_optlen(exthdr);
166 nexthdr = exthdr->nexthdr;
167 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
168 break;
169
170 case IPPROTO_UDP:
171 case IPPROTO_UDPLITE:
172 case IPPROTO_TCP:
173 case IPPROTO_SCTP:
174 case IPPROTO_DCCP:
175 if (!onlyproto && (nh + offset + 4 < skb->data ||
176 pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
177 __be16 *ports;
178
179 nh = skb_network_header(skb);
180 ports = (__be16 *)(nh + offset);
181 fl6->fl6_sport = ports[!!reverse];
182 fl6->fl6_dport = ports[!reverse];
183 }
184 fl6->flowi6_proto = nexthdr;
185 return;
186
187 case IPPROTO_ICMPV6:
188 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
189 u8 *icmp;
190
191 nh = skb_network_header(skb);
192 icmp = (u8 *)(nh + offset);
193 fl6->fl6_icmp_type = icmp[0];
194 fl6->fl6_icmp_code = icmp[1];
195 }
196 fl6->flowi6_proto = nexthdr;
197 return;
198
199#if IS_ENABLED(CONFIG_IPV6_MIP6)
200 case IPPROTO_MH:
201 offset += ipv6_optlen(exthdr);
202 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
203 struct ip6_mh *mh;
204
205 nh = skb_network_header(skb);
206 mh = (struct ip6_mh *)(nh + offset);
207 fl6->fl6_mh_type = mh->ip6mh_type;
208 }
209 fl6->flowi6_proto = nexthdr;
210 return;
211#endif
212
213
214 case IPPROTO_AH:
215 case IPPROTO_ESP:
216 case IPPROTO_COMP:
217 default:
218 fl6->fl6_ipsec_spi = 0;
219 fl6->flowi6_proto = nexthdr;
220 return;
221 }
222 }
223}
224
225static inline int xfrm6_garbage_collect(struct dst_ops *ops)
226{
227 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);
228
229 xfrm6_policy_afinfo.garbage_collect(net);
230 return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
231}
232
233static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
234 struct sk_buff *skb, u32 mtu)
235{
236 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
237 struct dst_entry *path = xdst->route;
238
239 path->ops->update_pmtu(path, sk, skb, mtu);
240}
241
242static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
243 struct sk_buff *skb)
244{
245 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
246 struct dst_entry *path = xdst->route;
247
248 path->ops->redirect(path, sk, skb);
249}
250
251static void xfrm6_dst_destroy(struct dst_entry *dst)
252{
253 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
254
255 if (likely(xdst->u.rt6.rt6i_idev))
256 in6_dev_put(xdst->u.rt6.rt6i_idev);
257 dst_destroy_metrics_generic(dst);
258 if (rt6_has_peer(&xdst->u.rt6)) {
259 struct inet_peer *peer = rt6_peer_ptr(&xdst->u.rt6);
260 inet_putpeer(peer);
261 }
262 xfrm_dst_destroy(xdst);
263}
264
265static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
266 int unregister)
267{
268 struct xfrm_dst *xdst;
269
270 if (!unregister)
271 return;
272
273 xdst = (struct xfrm_dst *)dst;
274 if (xdst->u.rt6.rt6i_idev->dev == dev) {
275 struct inet6_dev *loopback_idev =
276 in6_dev_get(dev_net(dev)->loopback_dev);
277 BUG_ON(!loopback_idev);
278
279 do {
280 in6_dev_put(xdst->u.rt6.rt6i_idev);
281 xdst->u.rt6.rt6i_idev = loopback_idev;
282 in6_dev_hold(loopback_idev);
283 xdst = (struct xfrm_dst *)xdst->u.dst.child;
284 } while (xdst->u.dst.xfrm);
285
286 __in6_dev_put(loopback_idev);
287 }
288
289 xfrm_dst_ifdown(dst, dev);
290}
291
292static struct dst_ops xfrm6_dst_ops = {
293 .family = AF_INET6,
294 .gc = xfrm6_garbage_collect,
295 .update_pmtu = xfrm6_update_pmtu,
296 .redirect = xfrm6_redirect,
297 .cow_metrics = dst_cow_metrics_generic,
298 .destroy = xfrm6_dst_destroy,
299 .ifdown = xfrm6_dst_ifdown,
300 .local_out = __ip6_local_out,
301 .gc_thresh = 32768,
302};
303
304static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
305 .family = AF_INET6,
306 .dst_ops = &xfrm6_dst_ops,
307 .dst_lookup = xfrm6_dst_lookup,
308 .get_saddr = xfrm6_get_saddr,
309 .decode_session = _decode_session6,
310 .get_tos = xfrm6_get_tos,
311 .init_dst = xfrm6_init_dst,
312 .init_path = xfrm6_init_path,
313 .fill_dst = xfrm6_fill_dst,
314 .blackhole_route = ip6_blackhole_route,
315};
316
317static int __init xfrm6_policy_init(void)
318{
319 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
320}
321
322static void xfrm6_policy_fini(void)
323{
324 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
325}
326
327#ifdef CONFIG_SYSCTL
328static struct ctl_table xfrm6_policy_table[] = {
329 {
330 .procname = "xfrm6_gc_thresh",
331 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
332 .maxlen = sizeof(int),
333 .mode = 0644,
334 .proc_handler = proc_dointvec,
335 },
336 { }
337};
338
339static int __net_init xfrm6_net_init(struct net *net)
340{
341 struct ctl_table *table;
342 struct ctl_table_header *hdr;
343
344 table = xfrm6_policy_table;
345 if (!net_eq(net, &init_net)) {
346 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
347 if (!table)
348 goto err_alloc;
349
350 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
351 }
352
353 hdr = register_net_sysctl(net, "net/ipv6", table);
354 if (!hdr)
355 goto err_reg;
356
357 net->ipv6.sysctl.xfrm6_hdr = hdr;
358 return 0;
359
360err_reg:
361 if (!net_eq(net, &init_net))
362 kfree(table);
363err_alloc:
364 return -ENOMEM;
365}
366
367static void __net_exit xfrm6_net_exit(struct net *net)
368{
369 struct ctl_table *table;
370
371 if (!net->ipv6.sysctl.xfrm6_hdr)
372 return;
373
374 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
375 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
376 if (!net_eq(net, &init_net))
377 kfree(table);
378}
379
380static struct pernet_operations xfrm6_net_ops = {
381 .init = xfrm6_net_init,
382 .exit = xfrm6_net_exit,
383};
384#endif
385
386int __init xfrm6_init(void)
387{
388 int ret;
389
390 dst_entries_init(&xfrm6_dst_ops);
391
392 ret = xfrm6_policy_init();
393 if (ret) {
394 dst_entries_destroy(&xfrm6_dst_ops);
395 goto out;
396 }
397 ret = xfrm6_state_init();
398 if (ret)
399 goto out_policy;
400
401 ret = xfrm6_protocol_init();
402 if (ret)
403 goto out_state;
404
405#ifdef CONFIG_SYSCTL
406 register_pernet_subsys(&xfrm6_net_ops);
407#endif
408out:
409 return ret;
410out_state:
411 xfrm6_state_fini();
412out_policy:
413 xfrm6_policy_fini();
414 goto out;
415}
416
417void xfrm6_fini(void)
418{
419#ifdef CONFIG_SYSCTL
420 unregister_pernet_subsys(&xfrm6_net_ops);
421#endif
422 xfrm6_protocol_fini();
423 xfrm6_policy_fini();
424 xfrm6_state_fini();
425 dst_entries_destroy(&xfrm6_dst_ops);
426}
427
