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