Merge branch 'upstream' into max-sect
[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 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 }