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[IPSEC]: Only set neighbour on top xfrm dst
[linux-2.6/sactl.git] / net / ipv6 / xfrm6_policy.c
blobbc508d0a87d580736879e39cae680cb5eaca4143
1 /*
2 * xfrm6_policy.c: based on xfrm4_policy.c
3 *
4 * Authors:
5 * Mitsuru KANDA @USAGI
6 * Kazunori MIYAZAWA @USAGI
7 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8 * IPv6 support
9 * YOSHIFUJI Hideaki
10 * Split up af-specific portion
11 *
12 */
13
14 #include <linux/compiler.h>
15 #include <linux/netdevice.h>
16 #include <net/addrconf.h>
17 #include <net/xfrm.h>
18 #include <net/ip.h>
19 #include <net/ipv6.h>
20 #include <net/ip6_route.h>
21 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
22 #include <net/mip6.h>
23 #endif
24
25 static struct dst_ops xfrm6_dst_ops;
26 static struct xfrm_policy_afinfo xfrm6_policy_afinfo;
27
28 static int xfrm6_dst_lookup(struct xfrm_dst **xdst, struct flowi *fl)
29 {
30 struct dst_entry *dst = ip6_route_output(NULL, fl);
31 int err = dst->error;
32 if (!err)
33 *xdst = (struct xfrm_dst *) dst;
34 else
35 dst_release(dst);
36 return err;
37 }
38
39 static int xfrm6_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
40 {
41 struct rt6_info *rt;
42 struct flowi fl_tunnel = {
43 .nl_u = {
44 .ip6_u = {
45 .daddr = *(struct in6_addr *)&daddr->a6,
46 },
47 },
48 };
49
50 if (!xfrm6_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
51 ipv6_get_saddr(&rt->u.dst, (struct in6_addr *)&daddr->a6,
52 (struct in6_addr *)&saddr->a6);
53 dst_release(&rt->u.dst);
54 return 0;
55 }
56 return -EHOSTUNREACH;
57 }
58
59 static struct dst_entry *
60 __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
61 {
62 struct dst_entry *dst;
63
64 /* Still not clear if we should set fl->fl6_{src,dst}... */
65 read_lock_bh(&policy->lock);
66 for (dst = policy->bundles; dst; dst = dst->next) {
67 struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
68 struct in6_addr fl_dst_prefix, fl_src_prefix;
69
70 ipv6_addr_prefix(&fl_dst_prefix,
71 &fl->fl6_dst,
72 xdst->u.rt6.rt6i_dst.plen);
73 ipv6_addr_prefix(&fl_src_prefix,
74 &fl->fl6_src,
75 xdst->u.rt6.rt6i_src.plen);
76 if (ipv6_addr_equal(&xdst->u.rt6.rt6i_dst.addr, &fl_dst_prefix) &&
77 ipv6_addr_equal(&xdst->u.rt6.rt6i_src.addr, &fl_src_prefix) &&
78 xfrm_bundle_ok(policy, xdst, fl, AF_INET6,
79 (xdst->u.rt6.rt6i_dst.plen != 128 ||
80 xdst->u.rt6.rt6i_src.plen != 128))) {
81 dst_clone(dst);
82 break;
83 }
84 }
85 read_unlock_bh(&policy->lock);
86 return dst;
87 }
88
89 static inline struct in6_addr*
90 __xfrm6_bundle_addr_remote(struct xfrm_state *x, struct in6_addr *addr)
91 {
92 return (x->type->remote_addr) ?
93 (struct in6_addr*)x->type->remote_addr(x, (xfrm_address_t *)addr) :
94 (struct in6_addr*)&x->id.daddr;
95 }
96
97 static inline struct in6_addr*
98 __xfrm6_bundle_addr_local(struct xfrm_state *x, struct in6_addr *addr)
99 {
100 return (x->type->local_addr) ?
101 (struct in6_addr*)x->type->local_addr(x, (xfrm_address_t *)addr) :
102 (struct in6_addr*)&x->props.saddr;
103 }
104
105 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
106 * all the metrics... Shortly, bundle a bundle.
107 */
108
109 static int
110 __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
111 struct flowi *fl, struct dst_entry **dst_p)
112 {
113 struct dst_entry *dst, *dst_prev;
114 struct rt6_info *rt0 = (struct rt6_info*)(*dst_p);
115 struct rt6_info *rt = rt0;
116 struct flowi fl_tunnel = {
117 .nl_u = {
118 .ip6_u = {
119 .saddr = fl->fl6_src,
120 .daddr = fl->fl6_dst,
121 }
122 }
123 };
124 int i;
125 int err = 0;
126 int header_len = 0;
127 int trailer_len = 0;
128
129 dst = dst_prev = NULL;
130 dst_hold(&rt->u.dst);
131
132 for (i = 0; i < nx; i++) {
133 struct dst_entry *dst1 = dst_alloc(&xfrm6_dst_ops);
134 struct xfrm_dst *xdst;
135
136 if (unlikely(dst1 == NULL)) {
137 err = -ENOBUFS;
138 dst_release(&rt->u.dst);
139 goto error;
140 }
141
142 if (!dst)
143 dst = dst1;
144 else {
145 dst_prev->child = dst1;
146 dst1->flags |= DST_NOHASH;
147 dst_clone(dst1);
148 }
149
150 xdst = (struct xfrm_dst *)dst1;
151 xdst->route = &rt->u.dst;
152 xdst->genid = xfrm[i]->genid;
153 if (rt->rt6i_node)
154 xdst->route_cookie = rt->rt6i_node->fn_sernum;
155
156 dst1->next = dst_prev;
157 dst_prev = dst1;
158
159 if (xfrm[i]->type->flags & XFRM_TYPE_NON_FRAGMENT)
160 ((struct rt6_info *)dst)->nfheader_len +=
161 xfrm[i]->props.header_len;
162 header_len += xfrm[i]->props.header_len;
163 trailer_len += xfrm[i]->props.trailer_len;
164
165 if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) {
166 unsigned short encap_family = xfrm[i]->props.family;
167 switch(encap_family) {
168 case AF_INET:
169 fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4;
170 fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4;
171 break;
172 case AF_INET6:
173 ipv6_addr_copy(&fl_tunnel.fl6_dst, __xfrm6_bundle_addr_remote(xfrm[i], &fl->fl6_dst));
174
175 ipv6_addr_copy(&fl_tunnel.fl6_src, __xfrm6_bundle_addr_local(xfrm[i], &fl->fl6_src));
176 break;
177 default:
178 BUG_ON(1);
179 }
180
181 err = xfrm_dst_lookup((struct xfrm_dst **) &rt,
182 &fl_tunnel, encap_family);
183 if (err)
184 goto error;
185 } else
186 dst_hold(&rt->u.dst);
187 }
188
189 dst_prev->child = &rt->u.dst;
190 dst->path = &rt->u.dst;
191
192 /* Copy neighbour for reachability confirmation */
193 dst->neighbour = neigh_clone(rt->u.dst.neighbour);
194
195 if (rt->rt6i_node)
196 ((struct xfrm_dst *)dst)->path_cookie = rt->rt6i_node->fn_sernum;
197
198 *dst_p = dst;
199 dst = dst_prev;
200
201 dst_prev = *dst_p;
202 i = 0;
203 for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
204 struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
205
206 dst_prev->xfrm = xfrm[i++];
207 dst_prev->dev = rt->u.dst.dev;
208 if (rt->u.dst.dev)
209 dev_hold(rt->u.dst.dev);
210 dst_prev->obsolete = -1;
211 dst_prev->flags |= DST_HOST;
212 dst_prev->lastuse = jiffies;
213 dst_prev->header_len = header_len;
214 dst_prev->trailer_len = trailer_len;
215 memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
216
217 dst_prev->input = rt->u.dst.input;
218 dst_prev->output = dst_prev->xfrm->outer_mode->afinfo->output;
219 /* Sheit... I remember I did this right. Apparently,
220 * it was magically lost, so this code needs audit */
221 x->u.rt6.rt6i_flags = rt0->rt6i_flags&(RTF_ANYCAST|RTF_LOCAL);
222 x->u.rt6.rt6i_metric = rt0->rt6i_metric;
223 x->u.rt6.rt6i_node = rt0->rt6i_node;
224 x->u.rt6.rt6i_gateway = rt0->rt6i_gateway;
225 memcpy(&x->u.rt6.rt6i_gateway, &rt0->rt6i_gateway, sizeof(x->u.rt6.rt6i_gateway));
226 x->u.rt6.rt6i_dst = rt0->rt6i_dst;
227 x->u.rt6.rt6i_src = rt0->rt6i_src;
228 x->u.rt6.rt6i_idev = rt0->rt6i_idev;
229 in6_dev_hold(rt0->rt6i_idev);
230 header_len -= x->u.dst.xfrm->props.header_len;
231 trailer_len -= x->u.dst.xfrm->props.trailer_len;
232 }
233
234 xfrm_init_pmtu(dst);
235 return 0;
236
237 error:
238 if (dst)
239 dst_free(dst);
240 return err;
241 }
242
243 static inline void
244 _decode_session6(struct sk_buff *skb, struct flowi *fl)
245 {
246 u16 offset = skb_network_header_len(skb);
247 struct ipv6hdr *hdr = ipv6_hdr(skb);
248 struct ipv6_opt_hdr *exthdr;
249 const unsigned char *nh = skb_network_header(skb);
250 u8 nexthdr = nh[IP6CB(skb)->nhoff];
251
252 memset(fl, 0, sizeof(struct flowi));
253 ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr);
254 ipv6_addr_copy(&fl->fl6_src, &hdr->saddr);
255
256 while (pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
257 nh = skb_network_header(skb);
258 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
259
260 switch (nexthdr) {
261 case NEXTHDR_ROUTING:
262 case NEXTHDR_HOP:
263 case NEXTHDR_DEST:
264 offset += ipv6_optlen(exthdr);
265 nexthdr = exthdr->nexthdr;
266 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
267 break;
268
269 case IPPROTO_UDP:
270 case IPPROTO_UDPLITE:
271 case IPPROTO_TCP:
272 case IPPROTO_SCTP:
273 case IPPROTO_DCCP:
274 if (pskb_may_pull(skb, nh + offset + 4 - skb->data)) {
275 __be16 *ports = (__be16 *)exthdr;
276
277 fl->fl_ip_sport = ports[0];
278 fl->fl_ip_dport = ports[1];
279 }
280 fl->proto = nexthdr;
281 return;
282
283 case IPPROTO_ICMPV6:
284 if (pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
285 u8 *icmp = (u8 *)exthdr;
286
287 fl->fl_icmp_type = icmp[0];
288 fl->fl_icmp_code = icmp[1];
289 }
290 fl->proto = nexthdr;
291 return;
292
293 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
294 case IPPROTO_MH:
295 if (pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
296 struct ip6_mh *mh;
297 mh = (struct ip6_mh *)exthdr;
298
299 fl->fl_mh_type = mh->ip6mh_type;
300 }
301 fl->proto = nexthdr;
302 return;
303 #endif
304
305 /* XXX Why are there these headers? */
306 case IPPROTO_AH:
307 case IPPROTO_ESP:
308 case IPPROTO_COMP:
309 default:
310 fl->fl_ipsec_spi = 0;
311 fl->proto = nexthdr;
312 return;
313 }
314 }
315 }
316
317 static inline int xfrm6_garbage_collect(void)
318 {
319 xfrm6_policy_afinfo.garbage_collect();
320 return (atomic_read(&xfrm6_dst_ops.entries) > xfrm6_dst_ops.gc_thresh*2);
321 }
322
323 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
324 {
325 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
326 struct dst_entry *path = xdst->route;
327
328 path->ops->update_pmtu(path, mtu);
329 }
330
331 static void xfrm6_dst_destroy(struct dst_entry *dst)
332 {
333 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
334
335 if (likely(xdst->u.rt6.rt6i_idev))
336 in6_dev_put(xdst->u.rt6.rt6i_idev);
337 xfrm_dst_destroy(xdst);
338 }
339
340 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
341 int unregister)
342 {
343 struct xfrm_dst *xdst;
344
345 if (!unregister)
346 return;
347
348 xdst = (struct xfrm_dst *)dst;
349 if (xdst->u.rt6.rt6i_idev->dev == dev) {
350 struct inet6_dev *loopback_idev = in6_dev_get(init_net.loopback_dev);
351 BUG_ON(!loopback_idev);
352
353 do {
354 in6_dev_put(xdst->u.rt6.rt6i_idev);
355 xdst->u.rt6.rt6i_idev = loopback_idev;
356 in6_dev_hold(loopback_idev);
357 xdst = (struct xfrm_dst *)xdst->u.dst.child;
358 } while (xdst->u.dst.xfrm);
359
360 __in6_dev_put(loopback_idev);
361 }
362
363 xfrm_dst_ifdown(dst, dev);
364 }
365
366 static struct dst_ops xfrm6_dst_ops = {
367 .family = AF_INET6,
368 .protocol = __constant_htons(ETH_P_IPV6),
369 .gc = xfrm6_garbage_collect,
370 .update_pmtu = xfrm6_update_pmtu,
371 .destroy = xfrm6_dst_destroy,
372 .ifdown = xfrm6_dst_ifdown,
373 .gc_thresh = 1024,
374 .entry_size = sizeof(struct xfrm_dst),
375 };
376
377 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
378 .family = AF_INET6,
379 .dst_ops = &xfrm6_dst_ops,
380 .dst_lookup = xfrm6_dst_lookup,
381 .get_saddr = xfrm6_get_saddr,
382 .find_bundle = __xfrm6_find_bundle,
383 .bundle_create = __xfrm6_bundle_create,
384 .decode_session = _decode_session6,
385 };
386
387 static void __init xfrm6_policy_init(void)
388 {
389 xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
390 }
391
392 static void xfrm6_policy_fini(void)
393 {
394 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
395 }
396
397 void __init xfrm6_init(void)
398 {
399 xfrm6_policy_init();
400 xfrm6_state_init();
401 }
402
403 void xfrm6_fini(void)
404 {
405 //xfrm6_input_fini();
406 xfrm6_policy_fini();
407 xfrm6_state_fini();
408 }
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