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Linux v2.6.17-rc2
[linux-2.6/next.git] / net / ipv6 / xfrm6_policy.c
blob88c840f1beb678a373284799dc6f8a693fd89544
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/config.h>
16 #include <linux/netdevice.h>
17 #include <net/addrconf.h>
18 #include <net/xfrm.h>
19 #include <net/ip.h>
20 #include <net/ipv6.h>
21 #include <net/ip6_route.h>
22
23 static struct dst_ops xfrm6_dst_ops;
24 static struct xfrm_policy_afinfo xfrm6_policy_afinfo;
25
26 static struct xfrm_type_map xfrm6_type_map = { .lock = RW_LOCK_UNLOCKED };
27
28 static int xfrm6_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
29 {
30 int err = 0;
31 *dst = (struct xfrm_dst*)ip6_route_output(NULL, fl);
32 if (!*dst)
33 err = -ENETUNREACH;
34 return err;
35 }
36
37 static struct dst_entry *
38 __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
39 {
40 struct dst_entry *dst;
41
42 /* Still not clear if we should set fl->fl6_{src,dst}... */
43 read_lock_bh(&policy->lock);
44 for (dst = policy->bundles; dst; dst = dst->next) {
45 struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
46 struct in6_addr fl_dst_prefix, fl_src_prefix;
47
48 ipv6_addr_prefix(&fl_dst_prefix,
49 &fl->fl6_dst,
50 xdst->u.rt6.rt6i_dst.plen);
51 ipv6_addr_prefix(&fl_src_prefix,
52 &fl->fl6_src,
53 xdst->u.rt6.rt6i_src.plen);
54 if (ipv6_addr_equal(&xdst->u.rt6.rt6i_dst.addr, &fl_dst_prefix) &&
55 ipv6_addr_equal(&xdst->u.rt6.rt6i_src.addr, &fl_src_prefix) &&
56 xfrm_bundle_ok(xdst, fl, AF_INET6)) {
57 dst_clone(dst);
58 break;
59 }
60 }
61 read_unlock_bh(&policy->lock);
62 return dst;
63 }
64
65 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
66 * all the metrics... Shortly, bundle a bundle.
67 */
68
69 static int
70 __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
71 struct flowi *fl, struct dst_entry **dst_p)
72 {
73 struct dst_entry *dst, *dst_prev;
74 struct rt6_info *rt0 = (struct rt6_info*)(*dst_p);
75 struct rt6_info *rt = rt0;
76 struct in6_addr *remote = &fl->fl6_dst;
77 struct in6_addr *local = &fl->fl6_src;
78 struct flowi fl_tunnel = {
79 .nl_u = {
80 .ip6_u = {
81 .saddr = *local,
82 .daddr = *remote
83 }
84 }
85 };
86 int i;
87 int err = 0;
88 int header_len = 0;
89 int trailer_len = 0;
90
91 dst = dst_prev = NULL;
92 dst_hold(&rt->u.dst);
93
94 for (i = 0; i < nx; i++) {
95 struct dst_entry *dst1 = dst_alloc(&xfrm6_dst_ops);
96 struct xfrm_dst *xdst;
97 int tunnel = 0;
98
99 if (unlikely(dst1 == NULL)) {
100 err = -ENOBUFS;
101 dst_release(&rt->u.dst);
102 goto error;
103 }
104
105 if (!dst)
106 dst = dst1;
107 else {
108 dst_prev->child = dst1;
109 dst1->flags |= DST_NOHASH;
110 dst_clone(dst1);
111 }
112
113 xdst = (struct xfrm_dst *)dst1;
114 xdst->route = &rt->u.dst;
115 if (rt->rt6i_node)
116 xdst->route_cookie = rt->rt6i_node->fn_sernum;
117
118 dst1->next = dst_prev;
119 dst_prev = dst1;
120 if (xfrm[i]->props.mode) {
121 remote = (struct in6_addr*)&xfrm[i]->id.daddr;
122 local = (struct in6_addr*)&xfrm[i]->props.saddr;
123 tunnel = 1;
124 }
125 header_len += xfrm[i]->props.header_len;
126 trailer_len += xfrm[i]->props.trailer_len;
127
128 if (tunnel) {
129 ipv6_addr_copy(&fl_tunnel.fl6_dst, remote);
130 ipv6_addr_copy(&fl_tunnel.fl6_src, local);
131 err = xfrm_dst_lookup((struct xfrm_dst **) &rt,
132 &fl_tunnel, AF_INET6);
133 if (err)
134 goto error;
135 } else
136 dst_hold(&rt->u.dst);
137 }
138
139 dst_prev->child = &rt->u.dst;
140 dst->path = &rt->u.dst;
141 if (rt->rt6i_node)
142 ((struct xfrm_dst *)dst)->path_cookie = rt->rt6i_node->fn_sernum;
143
144 *dst_p = dst;
145 dst = dst_prev;
146
147 dst_prev = *dst_p;
148 i = 0;
149 for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
150 struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
151
152 dst_prev->xfrm = xfrm[i++];
153 dst_prev->dev = rt->u.dst.dev;
154 if (rt->u.dst.dev)
155 dev_hold(rt->u.dst.dev);
156 dst_prev->obsolete = -1;
157 dst_prev->flags |= DST_HOST;
158 dst_prev->lastuse = jiffies;
159 dst_prev->header_len = header_len;
160 dst_prev->trailer_len = trailer_len;
161 memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
162
163 /* Copy neighbour for reachability confirmation */
164 dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour);
165 dst_prev->input = rt->u.dst.input;
166 dst_prev->output = xfrm6_output;
167 /* Sheit... I remember I did this right. Apparently,
168 * it was magically lost, so this code needs audit */
169 x->u.rt6.rt6i_flags = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
170 x->u.rt6.rt6i_metric = rt0->rt6i_metric;
171 x->u.rt6.rt6i_node = rt0->rt6i_node;
172 x->u.rt6.rt6i_gateway = rt0->rt6i_gateway;
173 memcpy(&x->u.rt6.rt6i_gateway, &rt0->rt6i_gateway, sizeof(x->u.rt6.rt6i_gateway));
174 x->u.rt6.rt6i_dst = rt0->rt6i_dst;
175 x->u.rt6.rt6i_src = rt0->rt6i_src;
176 x->u.rt6.rt6i_idev = rt0->rt6i_idev;
177 in6_dev_hold(rt0->rt6i_idev);
178 header_len -= x->u.dst.xfrm->props.header_len;
179 trailer_len -= x->u.dst.xfrm->props.trailer_len;
180 }
181
182 xfrm_init_pmtu(dst);
183 return 0;
184
185 error:
186 if (dst)
187 dst_free(dst);
188 return err;
189 }
190
191 static inline void
192 _decode_session6(struct sk_buff *skb, struct flowi *fl)
193 {
194 u16 offset = skb->h.raw - skb->nh.raw;
195 struct ipv6hdr *hdr = skb->nh.ipv6h;
196 struct ipv6_opt_hdr *exthdr;
197 u8 nexthdr = skb->nh.raw[IP6CB(skb)->nhoff];
198
199 memset(fl, 0, sizeof(struct flowi));
200 ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr);
201 ipv6_addr_copy(&fl->fl6_src, &hdr->saddr);
202
203 while (pskb_may_pull(skb, skb->nh.raw + offset + 1 - skb->data)) {
204 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
205
206 switch (nexthdr) {
207 case NEXTHDR_ROUTING:
208 case NEXTHDR_HOP:
209 case NEXTHDR_DEST:
210 offset += ipv6_optlen(exthdr);
211 nexthdr = exthdr->nexthdr;
212 exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
213 break;
214
215 case IPPROTO_UDP:
216 case IPPROTO_TCP:
217 case IPPROTO_SCTP:
218 case IPPROTO_DCCP:
219 if (pskb_may_pull(skb, skb->nh.raw + offset + 4 - skb->data)) {
220 u16 *ports = (u16 *)exthdr;
221
222 fl->fl_ip_sport = ports[0];
223 fl->fl_ip_dport = ports[1];
224 }
225 fl->proto = nexthdr;
226 return;
227
228 case IPPROTO_ICMPV6:
229 if (pskb_may_pull(skb, skb->nh.raw + offset + 2 - skb->data)) {
230 u8 *icmp = (u8 *)exthdr;
231
232 fl->fl_icmp_type = icmp[0];
233 fl->fl_icmp_code = icmp[1];
234 }
235 fl->proto = nexthdr;
236 return;
237
238 /* XXX Why are there these headers? */
239 case IPPROTO_AH:
240 case IPPROTO_ESP:
241 case IPPROTO_COMP:
242 default:
243 fl->fl_ipsec_spi = 0;
244 fl->proto = nexthdr;
245 return;
246 };
247 }
248 }
249
250 static inline int xfrm6_garbage_collect(void)
251 {
252 read_lock(&xfrm6_policy_afinfo.lock);
253 xfrm6_policy_afinfo.garbage_collect();
254 read_unlock(&xfrm6_policy_afinfo.lock);
255 return (atomic_read(&xfrm6_dst_ops.entries) > xfrm6_dst_ops.gc_thresh*2);
256 }
257
258 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
259 {
260 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
261 struct dst_entry *path = xdst->route;
262
263 path->ops->update_pmtu(path, mtu);
264 }
265
266 static void xfrm6_dst_destroy(struct dst_entry *dst)
267 {
268 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
269
270 if (likely(xdst->u.rt6.rt6i_idev))
271 in6_dev_put(xdst->u.rt6.rt6i_idev);
272 xfrm_dst_destroy(xdst);
273 }
274
275 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
276 int unregister)
277 {
278 struct xfrm_dst *xdst;
279
280 if (!unregister)
281 return;
282
283 xdst = (struct xfrm_dst *)dst;
284 if (xdst->u.rt6.rt6i_idev->dev == dev) {
285 struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev);
286 BUG_ON(!loopback_idev);
287
288 do {
289 in6_dev_put(xdst->u.rt6.rt6i_idev);
290 xdst->u.rt6.rt6i_idev = loopback_idev;
291 in6_dev_hold(loopback_idev);
292 xdst = (struct xfrm_dst *)xdst->u.dst.child;
293 } while (xdst->u.dst.xfrm);
294
295 __in6_dev_put(loopback_idev);
296 }
297
298 xfrm_dst_ifdown(dst, dev);
299 }
300
301 static struct dst_ops xfrm6_dst_ops = {
302 .family = AF_INET6,
303 .protocol = __constant_htons(ETH_P_IPV6),
304 .gc = xfrm6_garbage_collect,
305 .update_pmtu = xfrm6_update_pmtu,
306 .destroy = xfrm6_dst_destroy,
307 .ifdown = xfrm6_dst_ifdown,
308 .gc_thresh = 1024,
309 .entry_size = sizeof(struct xfrm_dst),
310 };
311
312 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
313 .family = AF_INET6,
314 .lock = RW_LOCK_UNLOCKED,
315 .type_map = &xfrm6_type_map,
316 .dst_ops = &xfrm6_dst_ops,
317 .dst_lookup = xfrm6_dst_lookup,
318 .find_bundle = __xfrm6_find_bundle,
319 .bundle_create = __xfrm6_bundle_create,
320 .decode_session = _decode_session6,
321 };
322
323 static void __init xfrm6_policy_init(void)
324 {
325 xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
326 }
327
328 static void xfrm6_policy_fini(void)
329 {
330 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
331 }
332
333 void __init xfrm6_init(void)
334 {
335 xfrm6_policy_init();
336 xfrm6_state_init();
337 }
338
339 void xfrm6_fini(void)
340 {
341 //xfrm6_input_fini();
342 xfrm6_policy_fini();
343 xfrm6_state_fini();
344 }
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