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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 Xu66cdb3c2007-11-13 21:37:28 -080011#include <linux/err.h>
12#include <linux/kernel.h>
Herbert Xuaabc9762005-05-03 16:27:10 -070013#include <linux/inetdevice.h>
Herbert Xu45ff5a32007-11-13 21:35:32 -080014#include <net/dst.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <net/xfrm.h>
16#include <net/ip.h>
17
18static struct dst_ops xfrm4_dst_ops;
19static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
20
Alexey Dobriyanc5b3cf42008-11-25 17:51:25 -080021static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
22 xfrm_address_t *saddr,
Herbert Xu66cdb3c2007-11-13 21:37:28 -080023 xfrm_address_t *daddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070024{
Herbert Xu66cdb3c2007-11-13 21:37:28 -080025 struct flowi fl = {
Patrick McHardya1e59ab2006-09-19 12:57:34 -070026 .nl_u = {
27 .ip4_u = {
Herbert Xu66cdb3c2007-11-13 21:37:28 -080028 .tos = tos,
Patrick McHardya1e59ab2006-09-19 12:57:34 -070029 .daddr = daddr->a4,
30 },
31 },
32 };
Herbert Xu66cdb3c2007-11-13 21:37:28 -080033 struct dst_entry *dst;
34 struct rtable *rt;
35 int err;
Patrick McHardya1e59ab2006-09-19 12:57:34 -070036
Herbert Xu66cdb3c2007-11-13 21:37:28 -080037 if (saddr)
38 fl.fl4_src = saddr->a4;
39
Alexey Dobriyanc5b3cf42008-11-25 17:51:25 -080040 err = __ip_route_output_key(net, &rt, &fl);
Herbert Xu66cdb3c2007-11-13 21:37:28 -080041 dst = &rt->u.dst;
42 if (err)
43 dst = ERR_PTR(err);
44 return dst;
45}
46
Alexey Dobriyanfbda33b2008-11-25 17:56:49 -080047static int xfrm4_get_saddr(struct net *net,
48 xfrm_address_t *saddr, xfrm_address_t *daddr)
Herbert Xu66cdb3c2007-11-13 21:37:28 -080049{
50 struct dst_entry *dst;
51 struct rtable *rt;
52
Alexey Dobriyanfbda33b2008-11-25 17:56:49 -080053 dst = xfrm4_dst_lookup(net, 0, NULL, daddr);
Herbert Xu66cdb3c2007-11-13 21:37:28 -080054 if (IS_ERR(dst))
55 return -EHOSTUNREACH;
56
57 rt = (struct rtable *)dst;
58 saddr->a4 = rt->rt_src;
59 dst_release(dst);
60 return 0;
Patrick McHardya1e59ab2006-09-19 12:57:34 -070061}
62
Linus Torvalds1da177e2005-04-16 15:20:36 -070063static struct dst_entry *
64__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
65{
66 struct dst_entry *dst;
67
68 read_lock_bh(&policy->lock);
69 for (dst = policy->bundles; dst; dst = dst->next) {
Jianjun Kong5a5f3a82008-11-03 00:24:34 -080070 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/
72 xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090073 xdst->u.rt.fl.fl4_src == fl->fl4_src &&
74 xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
Venkat Yekkirala5b368e62006-10-05 15:42:18 -050075 xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 dst_clone(dst);
77 break;
78 }
79 }
80 read_unlock_bh(&policy->lock);
81 return dst;
82}
83
Herbert Xu25ee3282007-12-11 09:32:34 -080084static int xfrm4_get_tos(struct flowi *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -070085{
Herbert Xu25ee3282007-12-11 09:32:34 -080086 return fl->fl4_tos;
87}
Linus Torvalds1da177e2005-04-16 15:20:36 -070088
Masahide NAKAMURAa1b05142007-12-20 20:41:12 -080089static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
90 int nfheader_len)
91{
92 return 0;
93}
94
Herbert Xu25ee3282007-12-11 09:32:34 -080095static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
96{
97 struct rtable *rt = (struct rtable *)xdst->route;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
Herbert Xu25ee3282007-12-11 09:32:34 -080099 xdst->u.rt.fl = rt->fl;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Herbert Xu25ee3282007-12-11 09:32:34 -0800101 xdst->u.dst.dev = dev;
102 dev_hold(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Herbert Xu25ee3282007-12-11 09:32:34 -0800104 xdst->u.rt.idev = in_dev_get(dev);
105 if (!xdst->u.rt.idev)
106 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
Herbert Xu25ee3282007-12-11 09:32:34 -0800108 xdst->u.rt.peer = rt->peer;
109 if (rt->peer)
110 atomic_inc(&rt->peer->refcnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111
Herbert Xu25ee3282007-12-11 09:32:34 -0800112 /* Sheit... I remember I did this right. Apparently,
113 * it was magically lost, so this code needs audit */
114 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
115 RTCF_LOCAL);
116 xdst->u.rt.rt_type = rt->rt_type;
117 xdst->u.rt.rt_src = rt->rt_src;
118 xdst->u.rt.rt_dst = rt->rt_dst;
119 xdst->u.rt.rt_gateway = rt->rt_gateway;
120 xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
Miika Komu43372262007-02-06 14:27:32 -0800121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123}
124
125static void
Herbert Xud5422ef2007-12-12 10:44:16 -0800126_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700128 struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700129 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131 memset(fl, 0, sizeof(struct flowi));
132 if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
133 switch (iph->protocol) {
134 case IPPROTO_UDP:
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800135 case IPPROTO_UDPLITE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 case IPPROTO_TCP:
137 case IPPROTO_SCTP:
Patrick McHardy9e999992005-12-19 14:03:46 -0800138 case IPPROTO_DCCP:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
Al Viro8c689a62006-11-08 00:20:21 -0800140 __be16 *ports = (__be16 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141
Herbert Xud5422ef2007-12-12 10:44:16 -0800142 fl->fl_ip_sport = ports[!!reverse];
143 fl->fl_ip_dport = ports[!reverse];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 }
145 break;
146
147 case IPPROTO_ICMP:
148 if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
149 u8 *icmp = xprth;
150
151 fl->fl_icmp_type = icmp[0];
152 fl->fl_icmp_code = icmp[1];
153 }
154 break;
155
156 case IPPROTO_ESP:
157 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
Al Viro4324a172006-09-27 18:49:07 -0700158 __be32 *ehdr = (__be32 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160 fl->fl_ipsec_spi = ehdr[0];
161 }
162 break;
163
164 case IPPROTO_AH:
165 if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
Al Viro4324a172006-09-27 18:49:07 -0700166 __be32 *ah_hdr = (__be32*)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
168 fl->fl_ipsec_spi = ah_hdr[1];
169 }
170 break;
171
172 case IPPROTO_COMP:
173 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
Al Viro4324a172006-09-27 18:49:07 -0700174 __be16 *ipcomp_hdr = (__be16 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
Alexey Dobriyan4195f812006-05-22 16:53:22 -0700176 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 }
178 break;
179 default:
180 fl->fl_ipsec_spi = 0;
181 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700182 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 }
184 fl->proto = iph->protocol;
Herbert Xud5422ef2007-12-12 10:44:16 -0800185 fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
186 fl->fl4_src = reverse ? iph->daddr : iph->saddr;
Herbert Xu4da30892006-02-23 16:19:26 -0800187 fl->fl4_tos = iph->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188}
189
Daniel Lezcano569d3642008-01-18 03:56:57 -0800190static inline int xfrm4_garbage_collect(struct dst_ops *ops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191{
Alexey Dobriyanddcfd792008-11-25 17:37:23 -0800192 xfrm4_policy_afinfo.garbage_collect(&init_net);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
194}
195
196static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
197{
198 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
199 struct dst_entry *path = xdst->route;
200
201 path->ops->update_pmtu(path, mtu);
202}
203
Herbert Xuaabc9762005-05-03 16:27:10 -0700204static void xfrm4_dst_destroy(struct dst_entry *dst)
205{
206 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
207
208 if (likely(xdst->u.rt.idev))
209 in_dev_put(xdst->u.rt.idev);
Herbert Xued3e37d2007-10-17 21:34:46 -0700210 if (likely(xdst->u.rt.peer))
David S. Miller26db1672006-12-06 23:45:15 -0800211 inet_putpeer(xdst->u.rt.peer);
Herbert Xuaabc9762005-05-03 16:27:10 -0700212 xfrm_dst_destroy(xdst);
213}
214
215static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
216 int unregister)
217{
218 struct xfrm_dst *xdst;
219
220 if (!unregister)
221 return;
222
223 xdst = (struct xfrm_dst *)dst;
224 if (xdst->u.rt.idev->dev == dev) {
Denis V. Lunev5a3e55d2007-12-07 00:38:10 -0800225 struct in_device *loopback_idev =
YOSHIFUJI Hideakic346dca2008-03-25 21:47:49 +0900226 in_dev_get(dev_net(dev)->loopback_dev);
Herbert Xuaabc9762005-05-03 16:27:10 -0700227 BUG_ON(!loopback_idev);
228
229 do {
230 in_dev_put(xdst->u.rt.idev);
231 xdst->u.rt.idev = loopback_idev;
232 in_dev_hold(loopback_idev);
233 xdst = (struct xfrm_dst *)xdst->u.dst.child;
234 } while (xdst->u.dst.xfrm);
235
236 __in_dev_put(loopback_idev);
237 }
238
239 xfrm_dst_ifdown(dst, dev);
240}
241
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242static struct dst_ops xfrm4_dst_ops = {
243 .family = AF_INET,
244 .protocol = __constant_htons(ETH_P_IP),
245 .gc = xfrm4_garbage_collect,
246 .update_pmtu = xfrm4_update_pmtu,
Herbert Xuaabc9762005-05-03 16:27:10 -0700247 .destroy = xfrm4_dst_destroy,
248 .ifdown = xfrm4_dst_ifdown,
Herbert Xu862b82c2007-11-13 21:43:11 -0800249 .local_out = __ip_local_out,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 .gc_thresh = 1024,
Eric Dumazete2422972008-01-30 20:07:45 -0800251 .entries = ATOMIC_INIT(0),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252};
253
254static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
255 .family = AF_INET,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 .dst_ops = &xfrm4_dst_ops,
257 .dst_lookup = xfrm4_dst_lookup,
Patrick McHardya1e59ab2006-09-19 12:57:34 -0700258 .get_saddr = xfrm4_get_saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 .find_bundle = __xfrm4_find_bundle,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 .decode_session = _decode_session4,
Herbert Xu25ee3282007-12-11 09:32:34 -0800261 .get_tos = xfrm4_get_tos,
Masahide NAKAMURAa1b05142007-12-20 20:41:12 -0800262 .init_path = xfrm4_init_path,
Herbert Xu25ee3282007-12-11 09:32:34 -0800263 .fill_dst = xfrm4_fill_dst,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264};
265
266static void __init xfrm4_policy_init(void)
267{
268 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
269}
270
271static void __exit xfrm4_policy_fini(void)
272{
273 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
274}
275
276void __init xfrm4_init(void)
277{
278 xfrm4_state_init();
279 xfrm4_policy_init();
280}
281