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YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * xfrm4_policy.c
3 *
4 * Changes:
5 * Kazunori MIYAZAWA @USAGI
6 * YOSHIFUJI Hideaki @USAGI
7 * Split up af-specific portion
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +09008 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07009 */
10
Herbert Xuaabc9762005-05-03 16:27:10 -070011#include <linux/compiler.h>
Herbert Xuaabc9762005-05-03 16:27:10 -070012#include <linux/inetdevice.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <net/xfrm.h>
14#include <net/ip.h>
15
16static struct dst_ops xfrm4_dst_ops;
17static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
18
Linus Torvalds1da177e2005-04-16 15:20:36 -070019static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
20{
21 return __ip_route_output_key((struct rtable**)dst, fl);
22}
23
Patrick McHardya1e59ab2006-09-19 12:57:34 -070024static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070043static 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 &&
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090053 xdst->u.rt.fl.fl4_src == fl->fl4_src &&
54 xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
Venkat Yekkirala5b368e62006-10-05 15:42:18 -050055 xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 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
68static 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 struct flowi fl_tunnel = {
76 .nl_u = {
77 .ip4_u = {
Miika Komu43372262007-02-06 14:27:32 -080078 .saddr = fl->fl4_src,
79 .daddr = fl->fl4_dst,
Herbert Xu4da30892006-02-23 16:19:26 -080080 .tos = fl->fl4_tos
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 }
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
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;
David S. Miller9d4a7062006-08-24 03:18:09 -0700112 xdst->genid = xfrm[i]->genid;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113
114 dst1->next = dst_prev;
115 dst_prev = dst1;
Miika Komu43372262007-02-06 14:27:32 -0800116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 header_len += xfrm[i]->props.header_len;
118 trailer_len += xfrm[i]->props.trailer_len;
119
Miika Komu43372262007-02-06 14:27:32 -0800120 if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL) {
121 unsigned short encap_family = xfrm[i]->props.family;
Stephen Hemminger132adf52007-03-08 20:44:43 -0800122 switch (encap_family) {
Miika Komu43372262007-02-06 14:27:32 -0800123 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 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
Miika Komu43372262007-02-06 14:27:32 -0800137 &fl_tunnel, encap_family);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 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;
Miika Komu43372262007-02-06 14:27:32 -0800154 struct xfrm_state_afinfo *afinfo;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 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;
Masahide NAKAMURA1b5c2292006-08-23 18:11:50 -0700165 dst_prev->nfheader_len = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 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;
Miika Komu43372262007-02-06 14:27:32 -0800172 /* 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;
David S. Millerf2f21022007-02-06 14:32:42 -0800178 err = -EAFNOSUPPORT;
Miika Komu43372262007-02-06 14:27:32 -0800179 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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 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;
Herbert Xuaabc9762005-05-03 16:27:10 -0700194 x->u.rt.idev = rt0->idev;
195 in_dev_hold(rt0->idev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 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
203error:
204 if (dst)
205 dst_free(dst);
206 return err;
207}
208
209static void
210_decode_session4(struct sk_buff *skb, struct flowi *fl)
211{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700212 struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700213 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
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:
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800219 case IPPROTO_UDPLITE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 case IPPROTO_TCP:
221 case IPPROTO_SCTP:
Patrick McHardy9e999992005-12-19 14:03:46 -0800222 case IPPROTO_DCCP:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
Al Viro8c689a62006-11-08 00:20:21 -0800224 __be16 *ports = (__be16 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225
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)) {
Al Viro4324a172006-09-27 18:49:07 -0700242 __be32 *ehdr = (__be32 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
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)) {
Al Viro4324a172006-09-27 18:49:07 -0700250 __be32 *ah_hdr = (__be32*)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
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)) {
Al Viro4324a172006-09-27 18:49:07 -0700258 __be16 *ipcomp_hdr = (__be16 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259
Alexey Dobriyan4195f812006-05-22 16:53:22 -0700260 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 }
262 break;
263 default:
264 fl->fl_ipsec_spi = 0;
265 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700266 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 }
268 fl->proto = iph->protocol;
269 fl->fl4_dst = iph->daddr;
270 fl->fl4_src = iph->saddr;
Herbert Xu4da30892006-02-23 16:19:26 -0800271 fl->fl4_tos = iph->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272}
273
274static inline int xfrm4_garbage_collect(void)
275{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 xfrm4_policy_afinfo.garbage_collect();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277 return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
278}
279
280static 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
Herbert Xuaabc9762005-05-03 16:27:10 -0700288static 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);
Bernhard Walleaef88112007-02-26 12:10:32 -0800294 if (dst->xfrm && dst->xfrm->props.family == AF_INET && likely(xdst->u.rt.peer))
David S. Miller26db1672006-12-06 23:45:15 -0800295 inet_putpeer(xdst->u.rt.peer);
Herbert Xuaabc9762005-05-03 16:27:10 -0700296 xfrm_dst_destroy(xdst);
297}
298
299static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325static 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,
Herbert Xuaabc9762005-05-03 16:27:10 -0700330 .destroy = xfrm4_dst_destroy,
331 .ifdown = xfrm4_dst_ifdown,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 .gc_thresh = 1024,
333 .entry_size = sizeof(struct xfrm_dst),
334};
335
336static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
337 .family = AF_INET,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338 .dst_ops = &xfrm4_dst_ops,
339 .dst_lookup = xfrm4_dst_lookup,
Patrick McHardya1e59ab2006-09-19 12:57:34 -0700340 .get_saddr = xfrm4_get_saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341 .find_bundle = __xfrm4_find_bundle,
342 .bundle_create = __xfrm4_bundle_create,
343 .decode_session = _decode_session4,
344};
345
346static void __init xfrm4_policy_init(void)
347{
348 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
349}
350
351static void __exit xfrm4_policy_fini(void)
352{
353 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
354}
355
356void __init xfrm4_init(void)
357{
358 xfrm4_state_init();
359 xfrm4_policy_init();
360}
361