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 HX |
11 | #include <asm/bug.h> |
12 | #include <linux/compiler.h> | |
1da177e4 | 13 | #include <linux/config.h> |
aabc9761 | 14 | #include <linux/inetdevice.h> |
1da177e4 LT |
15 | #include <net/xfrm.h> |
16 | #include <net/ip.h> | |
17 | ||
18 | static struct dst_ops xfrm4_dst_ops; | |
19 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo; | |
20 | ||
21 | static struct xfrm_type_map xfrm4_type_map = { .lock = RW_LOCK_UNLOCKED }; | |
22 | ||
23 | static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl) | |
24 | { | |
25 | return __ip_route_output_key((struct rtable**)dst, fl); | |
26 | } | |
27 | ||
28 | static struct dst_entry * | |
29 | __xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy) | |
30 | { | |
31 | struct dst_entry *dst; | |
32 | ||
33 | read_lock_bh(&policy->lock); | |
34 | for (dst = policy->bundles; dst; dst = dst->next) { | |
35 | struct xfrm_dst *xdst = (struct xfrm_dst*)dst; | |
36 | if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/ | |
37 | xdst->u.rt.fl.fl4_dst == fl->fl4_dst && | |
38 | xdst->u.rt.fl.fl4_src == fl->fl4_src && | |
39 | xfrm_bundle_ok(xdst, fl, AF_INET)) { | |
40 | dst_clone(dst); | |
41 | break; | |
42 | } | |
43 | } | |
44 | read_unlock_bh(&policy->lock); | |
45 | return dst; | |
46 | } | |
47 | ||
48 | /* Allocate chain of dst_entry's, attach known xfrm's, calculate | |
49 | * all the metrics... Shortly, bundle a bundle. | |
50 | */ | |
51 | ||
52 | static int | |
53 | __xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx, | |
54 | struct flowi *fl, struct dst_entry **dst_p) | |
55 | { | |
56 | struct dst_entry *dst, *dst_prev; | |
57 | struct rtable *rt0 = (struct rtable*)(*dst_p); | |
58 | struct rtable *rt = rt0; | |
59 | u32 remote = fl->fl4_dst; | |
60 | u32 local = fl->fl4_src; | |
61 | struct flowi fl_tunnel = { | |
62 | .nl_u = { | |
63 | .ip4_u = { | |
64 | .saddr = local, | |
65 | .daddr = remote | |
66 | } | |
67 | } | |
68 | }; | |
69 | int i; | |
70 | int err; | |
71 | int header_len = 0; | |
72 | int trailer_len = 0; | |
73 | ||
74 | dst = dst_prev = NULL; | |
75 | dst_hold(&rt->u.dst); | |
76 | ||
77 | for (i = 0; i < nx; i++) { | |
78 | struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops); | |
79 | struct xfrm_dst *xdst; | |
80 | int tunnel = 0; | |
81 | ||
82 | if (unlikely(dst1 == NULL)) { | |
83 | err = -ENOBUFS; | |
84 | dst_release(&rt->u.dst); | |
85 | goto error; | |
86 | } | |
87 | ||
88 | if (!dst) | |
89 | dst = dst1; | |
90 | else { | |
91 | dst_prev->child = dst1; | |
92 | dst1->flags |= DST_NOHASH; | |
93 | dst_clone(dst1); | |
94 | } | |
95 | ||
96 | xdst = (struct xfrm_dst *)dst1; | |
97 | xdst->route = &rt->u.dst; | |
98 | ||
99 | dst1->next = dst_prev; | |
100 | dst_prev = dst1; | |
101 | if (xfrm[i]->props.mode) { | |
102 | remote = xfrm[i]->id.daddr.a4; | |
103 | local = xfrm[i]->props.saddr.a4; | |
104 | tunnel = 1; | |
105 | } | |
106 | header_len += xfrm[i]->props.header_len; | |
107 | trailer_len += xfrm[i]->props.trailer_len; | |
108 | ||
109 | if (tunnel) { | |
110 | fl_tunnel.fl4_src = local; | |
111 | fl_tunnel.fl4_dst = remote; | |
112 | err = xfrm_dst_lookup((struct xfrm_dst **)&rt, | |
113 | &fl_tunnel, AF_INET); | |
114 | if (err) | |
115 | goto error; | |
116 | } else | |
117 | dst_hold(&rt->u.dst); | |
118 | } | |
119 | ||
120 | dst_prev->child = &rt->u.dst; | |
121 | dst->path = &rt->u.dst; | |
122 | ||
123 | *dst_p = dst; | |
124 | dst = dst_prev; | |
125 | ||
126 | dst_prev = *dst_p; | |
127 | i = 0; | |
128 | for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) { | |
129 | struct xfrm_dst *x = (struct xfrm_dst*)dst_prev; | |
130 | x->u.rt.fl = *fl; | |
131 | ||
132 | dst_prev->xfrm = xfrm[i++]; | |
133 | dst_prev->dev = rt->u.dst.dev; | |
134 | if (rt->u.dst.dev) | |
135 | dev_hold(rt->u.dst.dev); | |
136 | dst_prev->obsolete = -1; | |
137 | dst_prev->flags |= DST_HOST; | |
138 | dst_prev->lastuse = jiffies; | |
139 | dst_prev->header_len = header_len; | |
140 | dst_prev->trailer_len = trailer_len; | |
141 | memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics)); | |
142 | ||
143 | /* Copy neighbout for reachability confirmation */ | |
144 | dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour); | |
145 | dst_prev->input = rt->u.dst.input; | |
146 | dst_prev->output = xfrm4_output; | |
147 | if (rt->peer) | |
148 | atomic_inc(&rt->peer->refcnt); | |
149 | x->u.rt.peer = rt->peer; | |
150 | /* Sheit... I remember I did this right. Apparently, | |
151 | * it was magically lost, so this code needs audit */ | |
152 | x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL); | |
153 | x->u.rt.rt_type = rt->rt_type; | |
154 | x->u.rt.rt_src = rt0->rt_src; | |
155 | x->u.rt.rt_dst = rt0->rt_dst; | |
156 | x->u.rt.rt_gateway = rt->rt_gateway; | |
157 | x->u.rt.rt_spec_dst = rt0->rt_spec_dst; | |
aabc9761 HX |
158 | x->u.rt.idev = rt0->idev; |
159 | in_dev_hold(rt0->idev); | |
1da177e4 LT |
160 | header_len -= x->u.dst.xfrm->props.header_len; |
161 | trailer_len -= x->u.dst.xfrm->props.trailer_len; | |
162 | } | |
163 | ||
164 | xfrm_init_pmtu(dst); | |
165 | return 0; | |
166 | ||
167 | error: | |
168 | if (dst) | |
169 | dst_free(dst); | |
170 | return err; | |
171 | } | |
172 | ||
173 | static void | |
174 | _decode_session4(struct sk_buff *skb, struct flowi *fl) | |
175 | { | |
176 | struct iphdr *iph = skb->nh.iph; | |
177 | u8 *xprth = skb->nh.raw + iph->ihl*4; | |
178 | ||
179 | memset(fl, 0, sizeof(struct flowi)); | |
180 | if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) { | |
181 | switch (iph->protocol) { | |
182 | case IPPROTO_UDP: | |
183 | case IPPROTO_TCP: | |
184 | case IPPROTO_SCTP: | |
185 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
186 | u16 *ports = (u16 *)xprth; | |
187 | ||
188 | fl->fl_ip_sport = ports[0]; | |
189 | fl->fl_ip_dport = ports[1]; | |
190 | } | |
191 | break; | |
192 | ||
193 | case IPPROTO_ICMP: | |
194 | if (pskb_may_pull(skb, xprth + 2 - skb->data)) { | |
195 | u8 *icmp = xprth; | |
196 | ||
197 | fl->fl_icmp_type = icmp[0]; | |
198 | fl->fl_icmp_code = icmp[1]; | |
199 | } | |
200 | break; | |
201 | ||
202 | case IPPROTO_ESP: | |
203 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
204 | u32 *ehdr = (u32 *)xprth; | |
205 | ||
206 | fl->fl_ipsec_spi = ehdr[0]; | |
207 | } | |
208 | break; | |
209 | ||
210 | case IPPROTO_AH: | |
211 | if (pskb_may_pull(skb, xprth + 8 - skb->data)) { | |
212 | u32 *ah_hdr = (u32*)xprth; | |
213 | ||
214 | fl->fl_ipsec_spi = ah_hdr[1]; | |
215 | } | |
216 | break; | |
217 | ||
218 | case IPPROTO_COMP: | |
219 | if (pskb_may_pull(skb, xprth + 4 - skb->data)) { | |
220 | u16 *ipcomp_hdr = (u16 *)xprth; | |
221 | ||
222 | fl->fl_ipsec_spi = ntohl(ntohs(ipcomp_hdr[1])); | |
223 | } | |
224 | break; | |
225 | default: | |
226 | fl->fl_ipsec_spi = 0; | |
227 | break; | |
228 | }; | |
229 | } | |
230 | fl->proto = iph->protocol; | |
231 | fl->fl4_dst = iph->daddr; | |
232 | fl->fl4_src = iph->saddr; | |
233 | } | |
234 | ||
235 | static inline int xfrm4_garbage_collect(void) | |
236 | { | |
237 | read_lock(&xfrm4_policy_afinfo.lock); | |
238 | xfrm4_policy_afinfo.garbage_collect(); | |
239 | read_unlock(&xfrm4_policy_afinfo.lock); | |
240 | return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2); | |
241 | } | |
242 | ||
243 | static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu) | |
244 | { | |
245 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
246 | struct dst_entry *path = xdst->route; | |
247 | ||
248 | path->ops->update_pmtu(path, mtu); | |
249 | } | |
250 | ||
aabc9761 HX |
251 | static void xfrm4_dst_destroy(struct dst_entry *dst) |
252 | { | |
253 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
254 | ||
255 | if (likely(xdst->u.rt.idev)) | |
256 | in_dev_put(xdst->u.rt.idev); | |
257 | xfrm_dst_destroy(xdst); | |
258 | } | |
259 | ||
260 | static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, | |
261 | int unregister) | |
262 | { | |
263 | struct xfrm_dst *xdst; | |
264 | ||
265 | if (!unregister) | |
266 | return; | |
267 | ||
268 | xdst = (struct xfrm_dst *)dst; | |
269 | if (xdst->u.rt.idev->dev == dev) { | |
270 | struct in_device *loopback_idev = in_dev_get(&loopback_dev); | |
271 | BUG_ON(!loopback_idev); | |
272 | ||
273 | do { | |
274 | in_dev_put(xdst->u.rt.idev); | |
275 | xdst->u.rt.idev = loopback_idev; | |
276 | in_dev_hold(loopback_idev); | |
277 | xdst = (struct xfrm_dst *)xdst->u.dst.child; | |
278 | } while (xdst->u.dst.xfrm); | |
279 | ||
280 | __in_dev_put(loopback_idev); | |
281 | } | |
282 | ||
283 | xfrm_dst_ifdown(dst, dev); | |
284 | } | |
285 | ||
1da177e4 LT |
286 | static struct dst_ops xfrm4_dst_ops = { |
287 | .family = AF_INET, | |
288 | .protocol = __constant_htons(ETH_P_IP), | |
289 | .gc = xfrm4_garbage_collect, | |
290 | .update_pmtu = xfrm4_update_pmtu, | |
aabc9761 HX |
291 | .destroy = xfrm4_dst_destroy, |
292 | .ifdown = xfrm4_dst_ifdown, | |
1da177e4 LT |
293 | .gc_thresh = 1024, |
294 | .entry_size = sizeof(struct xfrm_dst), | |
295 | }; | |
296 | ||
297 | static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { | |
298 | .family = AF_INET, | |
299 | .lock = RW_LOCK_UNLOCKED, | |
300 | .type_map = &xfrm4_type_map, | |
301 | .dst_ops = &xfrm4_dst_ops, | |
302 | .dst_lookup = xfrm4_dst_lookup, | |
303 | .find_bundle = __xfrm4_find_bundle, | |
304 | .bundle_create = __xfrm4_bundle_create, | |
305 | .decode_session = _decode_session4, | |
306 | }; | |
307 | ||
308 | static void __init xfrm4_policy_init(void) | |
309 | { | |
310 | xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); | |
311 | } | |
312 | ||
313 | static void __exit xfrm4_policy_fini(void) | |
314 | { | |
315 | xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo); | |
316 | } | |
317 | ||
318 | void __init xfrm4_init(void) | |
319 | { | |
320 | xfrm4_state_init(); | |
321 | xfrm4_policy_init(); | |
322 | } | |
323 |