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Commit | Line | Data |
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e905a9ed | 1 | /* |
1da177e4 LT |
2 | * xfrm4_policy.c |
3 | * | |
4 | * Changes: | |
5 | * Kazunori MIYAZAWA @USAGI | |
6 | * YOSHIFUJI Hideaki @USAGI | |
7 | * Split up af-specific portion | |
e905a9ed | 8 | * |
1da177e4 LT |
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 && | |
e905a9ed YH |
53 | xdst->u.rt.fl.fl4_src == fl->fl4_src && |
54 | xdst->u.rt.fl.fl4_tos == fl->fl4_tos && | |
5b368e61 | 55 | xfrm_bundle_ok(policy, 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; | |
1da177e4 LT |
75 | struct flowi fl_tunnel = { |
76 | .nl_u = { | |
77 | .ip4_u = { | |
43372262 MK |
78 | .saddr = fl->fl4_src, |
79 | .daddr = fl->fl4_dst, | |
4da3089f | 80 | .tos = fl->fl4_tos |
1da177e4 LT |
81 | } |
82 | } | |
83 | }; | |
84 | int i; | |
85 | int err; | |
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(&xfrm4_dst_ops); | |
94 | struct xfrm_dst *xdst; | |
1da177e4 LT |
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; | |
9d4a706d | 112 | xdst->genid = xfrm[i]->genid; |
1da177e4 LT |
113 | |
114 | dst1->next = dst_prev; | |
115 | dst_prev = dst1; | |
43372262 | 116 | |
1da177e4 LT |
117 | header_len += xfrm[i]->props.header_len; |
118 | trailer_len += xfrm[i]->props.trailer_len; | |
119 | ||
43372262 MK |
120 | if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL) { |
121 | unsigned short encap_family = xfrm[i]->props.family; | |
132adf54 | 122 | switch (encap_family) { |
43372262 MK |
123 | case AF_INET: |
124 | fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4; | |
125 | fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4; | |
126 | break; | |
127 | #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) | |
128 | case AF_INET6: | |
129 | ipv6_addr_copy(&fl_tunnel.fl6_dst, (struct in6_addr*)&xfrm[i]->id.daddr.a6); | |
130 | ipv6_addr_copy(&fl_tunnel.fl6_src, (struct in6_addr*)&xfrm[i]->props.saddr.a6); | |
131 | break; | |
132 | #endif | |
133 | default: | |
134 | BUG_ON(1); | |
135 | } | |
1da177e4 | 136 | err = xfrm_dst_lookup((struct xfrm_dst **)&rt, |
43372262 | 137 | &fl_tunnel, encap_family); |
1da177e4 LT |
138 | if (err) |
139 | goto error; | |
140 | } else | |
141 | dst_hold(&rt->u.dst); | |
142 | } | |
143 | ||
144 | dst_prev->child = &rt->u.dst; | |
145 | dst->path = &rt->u.dst; | |
146 | ||
147 | *dst_p = dst; | |
148 | dst = dst_prev; | |
149 | ||
150 | dst_prev = *dst_p; | |
151 | i = 0; | |
152 | for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) { | |
153 | struct xfrm_dst *x = (struct xfrm_dst*)dst_prev; | |
43372262 | 154 | struct xfrm_state_afinfo *afinfo; |
1da177e4 LT |
155 | x->u.rt.fl = *fl; |
156 | ||
157 | dst_prev->xfrm = xfrm[i++]; | |
158 | dst_prev->dev = rt->u.dst.dev; | |
159 | if (rt->u.dst.dev) | |
160 | dev_hold(rt->u.dst.dev); | |
161 | dst_prev->obsolete = -1; | |
162 | dst_prev->flags |= DST_HOST; | |
163 | dst_prev->lastuse = jiffies; | |
164 | dst_prev->header_len = header_len; | |
1b5c2299 | 165 | dst_prev->nfheader_len = 0; |
1da177e4 LT |
166 | dst_prev->trailer_len = trailer_len; |
167 | memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics)); | |
168 | ||
169 | /* Copy neighbout for reachability confirmation */ | |
170 | dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour); | |
171 | dst_prev->input = rt->u.dst.input; | |
43372262 MK |
172 | /* XXX: When IPv6 module can be unloaded, we should manage reference |
173 | * to xfrm6_output in afinfo->output. Miyazawa | |
174 | * */ | |
175 | afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family); | |
176 | if (!afinfo) { | |
177 | dst = *dst_p; | |
f2f2102d | 178 | err = -EAFNOSUPPORT; |
43372262 MK |
179 | goto error; |
180 | } | |
181 | dst_prev->output = afinfo->output; | |
182 | xfrm_state_put_afinfo(afinfo); | |
183 | if (dst_prev->xfrm->props.family == AF_INET && rt->peer) | |
1da177e4 LT |
184 | atomic_inc(&rt->peer->refcnt); |
185 | x->u.rt.peer = rt->peer; | |
186 | /* Sheit... I remember I did this right. Apparently, | |
187 | * it was magically lost, so this code needs audit */ | |
188 | x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL); | |
189 | x->u.rt.rt_type = rt->rt_type; | |
190 | x->u.rt.rt_src = rt0->rt_src; | |
191 | x->u.rt.rt_dst = rt0->rt_dst; | |
192 | x->u.rt.rt_gateway = rt->rt_gateway; | |
193 | x->u.rt.rt_spec_dst = rt0->rt_spec_dst; | |
aabc9761 HX |
194 | x->u.rt.idev = rt0->idev; |
195 | in_dev_hold(rt0->idev); | |
1da177e4 LT |
196 | header_len -= x->u.dst.xfrm->props.header_len; |
197 | trailer_len -= x->u.dst.xfrm->props.trailer_len; | |
198 | } | |
199 | ||
200 | xfrm_init_pmtu(dst); | |
201 | return 0; | |
202 | ||
203 | error: | |
204 | if (dst) | |
205 | dst_free(dst); | |
206 | return err; | |
207 | } | |
208 | ||
209 | static void | |
210 | _decode_session4(struct sk_buff *skb, struct flowi *fl) | |
211 | { | |
212 | struct iphdr *iph = skb->nh.iph; | |
d56f90a7 | 213 | u8 *xprth = skb_network_header(skb) + iph->ihl * 4; |
1da177e4 LT |
214 | |
215 | memset(fl, 0, sizeof(struct flowi)); | |
216 | if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) { | |
217 | switch (iph->protocol) { | |
218 | case IPPROTO_UDP: | |
ba4e58ec | 219 | case IPPROTO_UDPLITE: |
1da177e4 LT |
220 | case IPPROTO_TCP: |
221 | case IPPROTO_SCTP: | |
9e999993 | 222 | case IPPROTO_DCCP: |
1da177e4 | 223 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { |
8c689a6e | 224 | __be16 *ports = (__be16 *)xprth; |
1da177e4 LT |
225 | |
226 | fl->fl_ip_sport = ports[0]; | |
227 | fl->fl_ip_dport = ports[1]; | |
228 | } | |
229 | break; | |
230 | ||
231 | case IPPROTO_ICMP: | |
232 | if (pskb_may_pull(skb, xprth + 2 - skb->data)) { | |
233 | u8 *icmp = xprth; | |
234 | ||
235 | fl->fl_icmp_type = icmp[0]; | |
236 | fl->fl_icmp_code = icmp[1]; | |
237 | } | |
238 | break; | |
239 | ||
240 | case IPPROTO_ESP: | |
241 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 242 | __be32 *ehdr = (__be32 *)xprth; |
1da177e4 LT |
243 | |
244 | fl->fl_ipsec_spi = ehdr[0]; | |
245 | } | |
246 | break; | |
247 | ||
248 | case IPPROTO_AH: | |
249 | if (pskb_may_pull(skb, xprth + 8 - skb->data)) { | |
4324a174 | 250 | __be32 *ah_hdr = (__be32*)xprth; |
1da177e4 LT |
251 | |
252 | fl->fl_ipsec_spi = ah_hdr[1]; | |
253 | } | |
254 | break; | |
255 | ||
256 | case IPPROTO_COMP: | |
257 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
4324a174 | 258 | __be16 *ipcomp_hdr = (__be16 *)xprth; |
1da177e4 | 259 | |
4195f814 | 260 | fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); |
1da177e4 LT |
261 | } |
262 | break; | |
263 | default: | |
264 | fl->fl_ipsec_spi = 0; | |
265 | break; | |
266 | }; | |
267 | } | |
268 | fl->proto = iph->protocol; | |
269 | fl->fl4_dst = iph->daddr; | |
270 | fl->fl4_src = iph->saddr; | |
4da3089f | 271 | fl->fl4_tos = iph->tos; |
1da177e4 LT |
272 | } |
273 | ||
274 | static inline int xfrm4_garbage_collect(void) | |
275 | { | |
1da177e4 | 276 | xfrm4_policy_afinfo.garbage_collect(); |
1da177e4 LT |
277 | return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2); |
278 | } | |
279 | ||
280 | static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu) | |
281 | { | |
282 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
283 | struct dst_entry *path = xdst->route; | |
284 | ||
285 | path->ops->update_pmtu(path, mtu); | |
286 | } | |
287 | ||
aabc9761 HX |
288 | static void xfrm4_dst_destroy(struct dst_entry *dst) |
289 | { | |
290 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
291 | ||
292 | if (likely(xdst->u.rt.idev)) | |
293 | in_dev_put(xdst->u.rt.idev); | |
aef8811a | 294 | if (dst->xfrm && dst->xfrm->props.family == AF_INET && likely(xdst->u.rt.peer)) |
26db1677 | 295 | inet_putpeer(xdst->u.rt.peer); |
aabc9761 HX |
296 | xfrm_dst_destroy(xdst); |
297 | } | |
298 | ||
299 | static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, | |
300 | int unregister) | |
301 | { | |
302 | struct xfrm_dst *xdst; | |
303 | ||
304 | if (!unregister) | |
305 | return; | |
306 | ||
307 | xdst = (struct xfrm_dst *)dst; | |
308 | if (xdst->u.rt.idev->dev == dev) { | |
309 | struct in_device *loopback_idev = in_dev_get(&loopback_dev); | |
310 | BUG_ON(!loopback_idev); | |
311 | ||
312 | do { | |
313 | in_dev_put(xdst->u.rt.idev); | |
314 | xdst->u.rt.idev = loopback_idev; | |
315 | in_dev_hold(loopback_idev); | |
316 | xdst = (struct xfrm_dst *)xdst->u.dst.child; | |
317 | } while (xdst->u.dst.xfrm); | |
318 | ||
319 | __in_dev_put(loopback_idev); | |
320 | } | |
321 | ||
322 | xfrm_dst_ifdown(dst, dev); | |
323 | } | |
324 | ||
1da177e4 LT |
325 | static struct dst_ops xfrm4_dst_ops = { |
326 | .family = AF_INET, | |
327 | .protocol = __constant_htons(ETH_P_IP), | |
328 | .gc = xfrm4_garbage_collect, | |
329 | .update_pmtu = xfrm4_update_pmtu, | |
aabc9761 HX |
330 | .destroy = xfrm4_dst_destroy, |
331 | .ifdown = xfrm4_dst_ifdown, | |
1da177e4 LT |
332 | .gc_thresh = 1024, |
333 | .entry_size = sizeof(struct xfrm_dst), | |
334 | }; | |
335 | ||
336 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { | |
337 | .family = AF_INET, | |
1da177e4 LT |
338 | .dst_ops = &xfrm4_dst_ops, |
339 | .dst_lookup = xfrm4_dst_lookup, | |
a1e59abf | 340 | .get_saddr = xfrm4_get_saddr, |
1da177e4 LT |
341 | .find_bundle = __xfrm4_find_bundle, |
342 | .bundle_create = __xfrm4_bundle_create, | |
343 | .decode_session = _decode_session4, | |
344 | }; | |
345 | ||
346 | static void __init xfrm4_policy_init(void) | |
347 | { | |
348 | xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); | |
349 | } | |
350 | ||
351 | static void __exit xfrm4_policy_fini(void) | |
352 | { | |
353 | xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo); | |
354 | } | |
355 | ||
356 | void __init xfrm4_init(void) | |
357 | { | |
358 | xfrm4_state_init(); | |
359 | xfrm4_policy_init(); | |
360 | } | |
361 |