Commit | Line | Data |
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1da177e4 LT |
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 | } |