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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * xfrm4_policy.c | |
3 | * | |
4 | * Changes: | |
5 | * Kazunori MIYAZAWA @USAGI | |
6 | * YOSHIFUJI Hideaki @USAGI | |
7 | * Split up af-specific portion | |
8 | * | |
9 | */ | |
10 | ||
aabc9761 | 11 | #include <linux/compiler.h> |
aabc9761 | 12 | #include <linux/inetdevice.h> |
1da177e4 LT |
13 | #include <net/xfrm.h> |
14 | #include <net/ip.h> | |
15 | ||
16 | static struct dst_ops xfrm4_dst_ops; | |
17 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo; | |
18 | ||
1da177e4 LT |
19 | static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl) |
20 | { | |
21 | return __ip_route_output_key((struct rtable**)dst, fl); | |
22 | } | |
23 | ||
a1e59abf PM |
24 | static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr) |
25 | { | |
26 | struct rtable *rt; | |
27 | struct flowi fl_tunnel = { | |
28 | .nl_u = { | |
29 | .ip4_u = { | |
30 | .daddr = daddr->a4, | |
31 | }, | |
32 | }, | |
33 | }; | |
34 | ||
35 | if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) { | |
36 | saddr->a4 = rt->rt_src; | |
37 | dst_release(&rt->u.dst); | |
38 | return 0; | |
39 | } | |
40 | return -EHOSTUNREACH; | |
41 | } | |
42 | ||
1da177e4 LT |
43 | static struct dst_entry * |
44 | __xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy) | |
45 | { | |
46 | struct dst_entry *dst; | |
47 | ||
48 | read_lock_bh(&policy->lock); | |
49 | for (dst = policy->bundles; dst; dst = dst->next) { | |
50 | struct xfrm_dst *xdst = (struct xfrm_dst*)dst; | |
51 | if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/ | |
52 | xdst->u.rt.fl.fl4_dst == fl->fl4_dst && | |
53 | xdst->u.rt.fl.fl4_src == fl->fl4_src && | |
4da3089f | 54 | xdst->u.rt.fl.fl4_tos == fl->fl4_tos && |
e53820de | 55 | xfrm_bundle_ok(xdst, fl, AF_INET, 0)) { |
1da177e4 LT |
56 | dst_clone(dst); |
57 | break; | |
58 | } | |
59 | } | |
60 | read_unlock_bh(&policy->lock); | |
61 | return dst; | |
62 | } | |
63 | ||
64 | /* Allocate chain of dst_entry's, attach known xfrm's, calculate | |
65 | * all the metrics... Shortly, bundle a bundle. | |
66 | */ | |
67 | ||
68 | static int | |
69 | __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx, | |
70 | struct flowi *fl, struct dst_entry **dst_p) | |
71 | { | |
72 | struct dst_entry *dst, *dst_prev; | |
73 | struct rtable *rt0 = (struct rtable*)(*dst_p); | |
74 | struct rtable *rt = rt0; | |
75 | u32 remote = fl->fl4_dst; | |
76 | u32 local = fl->fl4_src; | |
77 | struct flowi fl_tunnel = { | |
78 | .nl_u = { | |
79 | .ip4_u = { | |
80 | .saddr = local, | |
4da3089f HX |
81 | .daddr = remote, |
82 | .tos = fl->fl4_tos | |
1da177e4 LT |
83 | } |
84 | } | |
85 | }; | |
86 | int i; | |
87 | int err; | |
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(&xfrm4_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; | |
9d4a706d | 115 | xdst->genid = xfrm[i]->genid; |
1da177e4 LT |
116 | |
117 | dst1->next = dst_prev; | |
118 | dst_prev = dst1; | |
7e49e6de | 119 | if (xfrm[i]->props.mode != XFRM_MODE_TRANSPORT) { |
1da177e4 LT |
120 | remote = xfrm[i]->id.daddr.a4; |
121 | local = xfrm[i]->props.saddr.a4; | |
122 | tunnel = 1; | |
123 | } | |
124 | header_len += xfrm[i]->props.header_len; | |
125 | trailer_len += xfrm[i]->props.trailer_len; | |
126 | ||
127 | if (tunnel) { | |
128 | fl_tunnel.fl4_src = local; | |
129 | fl_tunnel.fl4_dst = remote; | |
130 | err = xfrm_dst_lookup((struct xfrm_dst **)&rt, | |
131 | &fl_tunnel, AF_INET); | |
132 | if (err) | |
133 | goto error; | |
134 | } else | |
135 | dst_hold(&rt->u.dst); | |
136 | } | |
137 | ||
138 | dst_prev->child = &rt->u.dst; | |
139 | dst->path = &rt->u.dst; | |
140 | ||
141 | *dst_p = dst; | |
142 | dst = dst_prev; | |
143 | ||
144 | dst_prev = *dst_p; | |
145 | i = 0; | |
146 | for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) { | |
147 | struct xfrm_dst *x = (struct xfrm_dst*)dst_prev; | |
148 | x->u.rt.fl = *fl; | |
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; | |
1b5c2299 | 158 | dst_prev->nfheader_len = 0; |
1da177e4 LT |
159 | dst_prev->trailer_len = trailer_len; |
160 | memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics)); | |
161 | ||
162 | /* Copy neighbout for reachability confirmation */ | |
163 | dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour); | |
164 | dst_prev->input = rt->u.dst.input; | |
165 | dst_prev->output = xfrm4_output; | |
166 | if (rt->peer) | |
167 | atomic_inc(&rt->peer->refcnt); | |
168 | x->u.rt.peer = rt->peer; | |
169 | /* Sheit... I remember I did this right. Apparently, | |
170 | * it was magically lost, so this code needs audit */ | |
171 | x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL); | |
172 | x->u.rt.rt_type = rt->rt_type; | |
173 | x->u.rt.rt_src = rt0->rt_src; | |
174 | x->u.rt.rt_dst = rt0->rt_dst; | |
175 | x->u.rt.rt_gateway = rt->rt_gateway; | |
176 | x->u.rt.rt_spec_dst = rt0->rt_spec_dst; | |
aabc9761 HX |
177 | x->u.rt.idev = rt0->idev; |
178 | in_dev_hold(rt0->idev); | |
1da177e4 LT |
179 | header_len -= x->u.dst.xfrm->props.header_len; |
180 | trailer_len -= x->u.dst.xfrm->props.trailer_len; | |
181 | } | |
182 | ||
183 | xfrm_init_pmtu(dst); | |
184 | return 0; | |
185 | ||
186 | error: | |
187 | if (dst) | |
188 | dst_free(dst); | |
189 | return err; | |
190 | } | |
191 | ||
192 | static void | |
193 | _decode_session4(struct sk_buff *skb, struct flowi *fl) | |
194 | { | |
195 | struct iphdr *iph = skb->nh.iph; | |
196 | u8 *xprth = skb->nh.raw + iph->ihl*4; | |
197 | ||
198 | memset(fl, 0, sizeof(struct flowi)); | |
199 | if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) { | |
200 | switch (iph->protocol) { | |
201 | case IPPROTO_UDP: | |
202 | case IPPROTO_TCP: | |
203 | case IPPROTO_SCTP: | |
9e999993 | 204 | case IPPROTO_DCCP: |
1da177e4 LT |
205 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { |
206 | u16 *ports = (u16 *)xprth; | |
207 | ||
208 | fl->fl_ip_sport = ports[0]; | |
209 | fl->fl_ip_dport = ports[1]; | |
210 | } | |
211 | break; | |
212 | ||
213 | case IPPROTO_ICMP: | |
214 | if (pskb_may_pull(skb, xprth + 2 - skb->data)) { | |
215 | u8 *icmp = xprth; | |
216 | ||
217 | fl->fl_icmp_type = icmp[0]; | |
218 | fl->fl_icmp_code = icmp[1]; | |
219 | } | |
220 | break; | |
221 | ||
222 | case IPPROTO_ESP: | |
223 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 224 | __be32 *ehdr = (__be32 *)xprth; |
1da177e4 LT |
225 | |
226 | fl->fl_ipsec_spi = ehdr[0]; | |
227 | } | |
228 | break; | |
229 | ||
230 | case IPPROTO_AH: | |
231 | if (pskb_may_pull(skb, xprth + 8 - skb->data)) { | |
4324a174 | 232 | __be32 *ah_hdr = (__be32*)xprth; |
1da177e4 LT |
233 | |
234 | fl->fl_ipsec_spi = ah_hdr[1]; | |
235 | } | |
236 | break; | |
237 | ||
238 | case IPPROTO_COMP: | |
239 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 240 | __be16 *ipcomp_hdr = (__be16 *)xprth; |
1da177e4 | 241 | |
4195f814 | 242 | fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); |
1da177e4 LT |
243 | } |
244 | break; | |
245 | default: | |
246 | fl->fl_ipsec_spi = 0; | |
247 | break; | |
248 | }; | |
249 | } | |
250 | fl->proto = iph->protocol; | |
251 | fl->fl4_dst = iph->daddr; | |
252 | fl->fl4_src = iph->saddr; | |
4da3089f | 253 | fl->fl4_tos = iph->tos; |
1da177e4 LT |
254 | } |
255 | ||
256 | static inline int xfrm4_garbage_collect(void) | |
257 | { | |
1da177e4 | 258 | xfrm4_policy_afinfo.garbage_collect(); |
1da177e4 LT |
259 | return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2); |
260 | } | |
261 | ||
262 | static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu) | |
263 | { | |
264 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
265 | struct dst_entry *path = xdst->route; | |
266 | ||
267 | path->ops->update_pmtu(path, mtu); | |
268 | } | |
269 | ||
aabc9761 HX |
270 | static void xfrm4_dst_destroy(struct dst_entry *dst) |
271 | { | |
272 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
273 | ||
274 | if (likely(xdst->u.rt.idev)) | |
275 | in_dev_put(xdst->u.rt.idev); | |
276 | xfrm_dst_destroy(xdst); | |
277 | } | |
278 | ||
279 | static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, | |
280 | int unregister) | |
281 | { | |
282 | struct xfrm_dst *xdst; | |
283 | ||
284 | if (!unregister) | |
285 | return; | |
286 | ||
287 | xdst = (struct xfrm_dst *)dst; | |
288 | if (xdst->u.rt.idev->dev == dev) { | |
289 | struct in_device *loopback_idev = in_dev_get(&loopback_dev); | |
290 | BUG_ON(!loopback_idev); | |
291 | ||
292 | do { | |
293 | in_dev_put(xdst->u.rt.idev); | |
294 | xdst->u.rt.idev = loopback_idev; | |
295 | in_dev_hold(loopback_idev); | |
296 | xdst = (struct xfrm_dst *)xdst->u.dst.child; | |
297 | } while (xdst->u.dst.xfrm); | |
298 | ||
299 | __in_dev_put(loopback_idev); | |
300 | } | |
301 | ||
302 | xfrm_dst_ifdown(dst, dev); | |
303 | } | |
304 | ||
1da177e4 LT |
305 | static struct dst_ops xfrm4_dst_ops = { |
306 | .family = AF_INET, | |
307 | .protocol = __constant_htons(ETH_P_IP), | |
308 | .gc = xfrm4_garbage_collect, | |
309 | .update_pmtu = xfrm4_update_pmtu, | |
aabc9761 HX |
310 | .destroy = xfrm4_dst_destroy, |
311 | .ifdown = xfrm4_dst_ifdown, | |
1da177e4 LT |
312 | .gc_thresh = 1024, |
313 | .entry_size = sizeof(struct xfrm_dst), | |
314 | }; | |
315 | ||
316 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { | |
317 | .family = AF_INET, | |
1da177e4 LT |
318 | .dst_ops = &xfrm4_dst_ops, |
319 | .dst_lookup = xfrm4_dst_lookup, | |
a1e59abf | 320 | .get_saddr = xfrm4_get_saddr, |
1da177e4 LT |
321 | .find_bundle = __xfrm4_find_bundle, |
322 | .bundle_create = __xfrm4_bundle_create, | |
323 | .decode_session = _decode_session4, | |
324 | }; | |
325 | ||
326 | static void __init xfrm4_policy_init(void) | |
327 | { | |
328 | xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); | |
329 | } | |
330 | ||
331 | static void __exit xfrm4_policy_fini(void) | |
332 | { | |
333 | xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo); | |
334 | } | |
335 | ||
336 | void __init xfrm4_init(void) | |
337 | { | |
338 | xfrm4_state_init(); | |
339 | xfrm4_policy_init(); | |
340 | } | |
341 |