Linux-2.6.12-rc2
[linux-2.6.git] / 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/config.h>
15 #include <net/xfrm.h>
16 #include <net/ip.h>
17 #include <net/ipv6.h>
18 #include <net/ip6_route.h>
19
20 static struct dst_ops xfrm6_dst_ops;
21 static struct xfrm_policy_afinfo xfrm6_policy_afinfo;
22
23 static struct xfrm_type_map xfrm6_type_map = { .lock = RW_LOCK_UNLOCKED };
24
25 static int xfrm6_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
26 {
27         int err = 0;
28         *dst = (struct xfrm_dst*)ip6_route_output(NULL, fl);
29         if (!*dst)
30                 err = -ENETUNREACH;
31         return err;
32 }
33
34 static struct dst_entry *
35 __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
36 {
37         struct dst_entry *dst;
38
39         /* Still not clear if we should set fl->fl6_{src,dst}... */
40         read_lock_bh(&policy->lock);
41         for (dst = policy->bundles; dst; dst = dst->next) {
42                 struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
43                 struct in6_addr fl_dst_prefix, fl_src_prefix;
44
45                 ipv6_addr_prefix(&fl_dst_prefix,
46                                  &fl->fl6_dst,
47                                  xdst->u.rt6.rt6i_dst.plen);
48                 ipv6_addr_prefix(&fl_src_prefix,
49                                  &fl->fl6_src,
50                                  xdst->u.rt6.rt6i_src.plen);
51                 if (ipv6_addr_equal(&xdst->u.rt6.rt6i_dst.addr, &fl_dst_prefix) &&
52                     ipv6_addr_equal(&xdst->u.rt6.rt6i_src.addr, &fl_src_prefix) &&
53                     xfrm_bundle_ok(xdst, fl, AF_INET6)) {
54                         dst_clone(dst);
55                         break;
56                 }
57         }
58         read_unlock_bh(&policy->lock);
59         return dst;
60 }
61
62 /* Allocate chain of dst_entry's, attach known xfrm's, calculate
63  * all the metrics... Shortly, bundle a bundle.
64  */
65
66 static int
67 __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
68                       struct flowi *fl, struct dst_entry **dst_p)
69 {
70         struct dst_entry *dst, *dst_prev;
71         struct rt6_info *rt0 = (struct rt6_info*)(*dst_p);
72         struct rt6_info *rt  = rt0;
73         struct in6_addr *remote = &fl->fl6_dst;
74         struct in6_addr *local  = &fl->fl6_src;
75         struct flowi fl_tunnel = {
76                 .nl_u = {
77                         .ip6_u = {
78                                 .saddr = *local,
79                                 .daddr = *remote
80                         }
81                 }
82         };
83         int i;
84         int err = 0;
85         int header_len = 0;
86         int trailer_len = 0;
87
88         dst = dst_prev = NULL;
89         dst_hold(&rt->u.dst);
90
91         for (i = 0; i < nx; i++) {
92                 struct dst_entry *dst1 = dst_alloc(&xfrm6_dst_ops);
93                 struct xfrm_dst *xdst;
94                 int tunnel = 0;
95
96                 if (unlikely(dst1 == NULL)) {
97                         err = -ENOBUFS;
98                         dst_release(&rt->u.dst);
99                         goto error;
100                 }
101
102                 if (!dst)
103                         dst = dst1;
104                 else {
105                         dst_prev->child = dst1;
106                         dst1->flags |= DST_NOHASH;
107                         dst_clone(dst1);
108                 }
109
110                 xdst = (struct xfrm_dst *)dst1;
111                 xdst->route = &rt->u.dst;
112
113                 dst1->next = dst_prev;
114                 dst_prev = dst1;
115                 if (xfrm[i]->props.mode) {
116                         remote = (struct in6_addr*)&xfrm[i]->id.daddr;
117                         local  = (struct in6_addr*)&xfrm[i]->props.saddr;
118                         tunnel = 1;
119                 }
120                 header_len += xfrm[i]->props.header_len;
121                 trailer_len += xfrm[i]->props.trailer_len;
122
123                 if (tunnel) {
124                         ipv6_addr_copy(&fl_tunnel.fl6_dst, remote);
125                         ipv6_addr_copy(&fl_tunnel.fl6_src, local);
126                         err = xfrm_dst_lookup((struct xfrm_dst **) &rt,
127                                               &fl_tunnel, AF_INET6);
128                         if (err)
129                                 goto error;
130                 } else
131                         dst_hold(&rt->u.dst);
132         }
133
134         dst_prev->child = &rt->u.dst;
135         dst->path = &rt->u.dst;
136
137         *dst_p = dst;
138         dst = dst_prev;
139
140         dst_prev = *dst_p;
141         i = 0;
142         for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
143                 struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
144
145                 dst_prev->xfrm = xfrm[i++];
146                 dst_prev->dev = rt->u.dst.dev;
147                 if (rt->u.dst.dev)
148                         dev_hold(rt->u.dst.dev);
149                 dst_prev->obsolete      = -1;
150                 dst_prev->flags        |= DST_HOST;
151                 dst_prev->lastuse       = jiffies;
152                 dst_prev->header_len    = header_len;
153                 dst_prev->trailer_len   = trailer_len;
154                 memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
155
156                 /* Copy neighbour for reachability confirmation */
157                 dst_prev->neighbour     = neigh_clone(rt->u.dst.neighbour);
158                 dst_prev->input         = rt->u.dst.input;
159                 dst_prev->output        = xfrm6_output;
160                 /* Sheit... I remember I did this right. Apparently,
161                  * it was magically lost, so this code needs audit */
162                 x->u.rt6.rt6i_flags    = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
163                 x->u.rt6.rt6i_metric   = rt0->rt6i_metric;
164                 x->u.rt6.rt6i_node     = rt0->rt6i_node;
165                 x->u.rt6.rt6i_gateway  = rt0->rt6i_gateway;
166                 memcpy(&x->u.rt6.rt6i_gateway, &rt0->rt6i_gateway, sizeof(x->u.rt6.rt6i_gateway)); 
167                 x->u.rt6.rt6i_dst      = rt0->rt6i_dst;
168                 x->u.rt6.rt6i_src      = rt0->rt6i_src; 
169                 header_len -= x->u.dst.xfrm->props.header_len;
170                 trailer_len -= x->u.dst.xfrm->props.trailer_len;
171         }
172
173         xfrm_init_pmtu(dst);
174         return 0;
175
176 error:
177         if (dst)
178                 dst_free(dst);
179         return err;
180 }
181
182 static inline void
183 _decode_session6(struct sk_buff *skb, struct flowi *fl)
184 {
185         u16 offset = sizeof(struct ipv6hdr);
186         struct ipv6hdr *hdr = skb->nh.ipv6h;
187         struct ipv6_opt_hdr *exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
188         u8 nexthdr = skb->nh.ipv6h->nexthdr;
189
190         memset(fl, 0, sizeof(struct flowi));
191         ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr);
192         ipv6_addr_copy(&fl->fl6_src, &hdr->saddr);
193
194         while (pskb_may_pull(skb, skb->nh.raw + offset + 1 - skb->data)) {
195                 switch (nexthdr) {
196                 case NEXTHDR_ROUTING:
197                 case NEXTHDR_HOP:
198                 case NEXTHDR_DEST:
199                         offset += ipv6_optlen(exthdr);
200                         nexthdr = exthdr->nexthdr;
201                         exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
202                         break;
203
204                 case IPPROTO_UDP:
205                 case IPPROTO_TCP:
206                 case IPPROTO_SCTP:
207                         if (pskb_may_pull(skb, skb->nh.raw + offset + 4 - skb->data)) {
208                                 u16 *ports = (u16 *)exthdr;
209
210                                 fl->fl_ip_sport = ports[0];
211                                 fl->fl_ip_dport = ports[1];
212                         }
213                         fl->proto = nexthdr;
214                         return;
215
216                 case IPPROTO_ICMPV6:
217                         if (pskb_may_pull(skb, skb->nh.raw + offset + 2 - skb->data)) {
218                                 u8 *icmp = (u8 *)exthdr;
219
220                                 fl->fl_icmp_type = icmp[0];
221                                 fl->fl_icmp_code = icmp[1];
222                         }
223                         fl->proto = nexthdr;
224                         return;
225
226                 /* XXX Why are there these headers? */
227                 case IPPROTO_AH:
228                 case IPPROTO_ESP:
229                 case IPPROTO_COMP:
230                 default:
231                         fl->fl_ipsec_spi = 0;
232                         fl->proto = nexthdr;
233                         return;
234                 };
235         }
236 }
237
238 static inline int xfrm6_garbage_collect(void)
239 {
240         read_lock(&xfrm6_policy_afinfo.lock);
241         xfrm6_policy_afinfo.garbage_collect();
242         read_unlock(&xfrm6_policy_afinfo.lock);
243         return (atomic_read(&xfrm6_dst_ops.entries) > xfrm6_dst_ops.gc_thresh*2);
244 }
245
246 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
247 {
248         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
249         struct dst_entry *path = xdst->route;
250
251         path->ops->update_pmtu(path, mtu);
252 }
253
254 static struct dst_ops xfrm6_dst_ops = {
255         .family =               AF_INET6,
256         .protocol =             __constant_htons(ETH_P_IPV6),
257         .gc =                   xfrm6_garbage_collect,
258         .update_pmtu =          xfrm6_update_pmtu,
259         .gc_thresh =            1024,
260         .entry_size =           sizeof(struct xfrm_dst),
261 };
262
263 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
264         .family =               AF_INET6,
265         .lock =                 RW_LOCK_UNLOCKED,
266         .type_map =             &xfrm6_type_map,
267         .dst_ops =              &xfrm6_dst_ops,
268         .dst_lookup =           xfrm6_dst_lookup,
269         .find_bundle =          __xfrm6_find_bundle,
270         .bundle_create =        __xfrm6_bundle_create,
271         .decode_session =       _decode_session6,
272 };
273
274 static void __init xfrm6_policy_init(void)
275 {
276         xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
277 }
278
279 static void xfrm6_policy_fini(void)
280 {
281         xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
282 }
283
284 void __init xfrm6_init(void)
285 {
286         xfrm6_policy_init();
287         xfrm6_state_init();
288 }
289
290 void xfrm6_fini(void)
291 {
292         //xfrm6_input_fini();
293         xfrm6_policy_fini();
294         xfrm6_state_fini();
295 }