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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
Herbert Xu66cdb3c2007-11-13 21:37:28 -080021static struct dst_entry *xfrm4_dst_lookup(int tos, xfrm_address_t *saddr,
22 xfrm_address_t *daddr)
Linus Torvalds1da177e2005-04-16 15:20:36 -070023{
Herbert Xu66cdb3c2007-11-13 21:37:28 -080024 struct flowi fl = {
Patrick McHardya1e59ab2006-09-19 12:57:34 -070025 .nl_u = {
26 .ip4_u = {
Herbert Xu66cdb3c2007-11-13 21:37:28 -080027 .tos = tos,
Patrick McHardya1e59ab2006-09-19 12:57:34 -070028 .daddr = daddr->a4,
29 },
30 },
31 };
Herbert Xu66cdb3c2007-11-13 21:37:28 -080032 struct dst_entry *dst;
33 struct rtable *rt;
34 int err;
Patrick McHardya1e59ab2006-09-19 12:57:34 -070035
Herbert Xu66cdb3c2007-11-13 21:37:28 -080036 if (saddr)
37 fl.fl4_src = saddr->a4;
38
39 err = __ip_route_output_key(&rt, &fl);
40 dst = &rt->u.dst;
41 if (err)
42 dst = ERR_PTR(err);
43 return dst;
44}
45
46static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
47{
48 struct dst_entry *dst;
49 struct rtable *rt;
50
51 dst = xfrm4_dst_lookup(0, NULL, daddr);
52 if (IS_ERR(dst))
53 return -EHOSTUNREACH;
54
55 rt = (struct rtable *)dst;
56 saddr->a4 = rt->rt_src;
57 dst_release(dst);
58 return 0;
Patrick McHardya1e59ab2006-09-19 12:57:34 -070059}
60
Linus Torvalds1da177e2005-04-16 15:20:36 -070061static struct dst_entry *
62__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
63{
64 struct dst_entry *dst;
65
66 read_lock_bh(&policy->lock);
67 for (dst = policy->bundles; dst; dst = dst->next) {
68 struct xfrm_dst *xdst = (struct xfrm_dst*)dst;
69 if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/
70 xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
YOSHIFUJI Hideakie905a9e2007-02-09 23:24:47 +090071 xdst->u.rt.fl.fl4_src == fl->fl4_src &&
72 xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
Venkat Yekkirala5b368e62006-10-05 15:42:18 -050073 xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 dst_clone(dst);
75 break;
76 }
77 }
78 read_unlock_bh(&policy->lock);
79 return dst;
80}
81
Herbert Xu25ee3282007-12-11 09:32:34 -080082static int xfrm4_get_tos(struct flowi *fl)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
Herbert Xu25ee3282007-12-11 09:32:34 -080084 return fl->fl4_tos;
85}
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
Herbert Xu25ee3282007-12-11 09:32:34 -080087static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
88{
89 struct rtable *rt = (struct rtable *)xdst->route;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Herbert Xu25ee3282007-12-11 09:32:34 -080091 xdst->u.rt.fl = rt->fl;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
Herbert Xu25ee3282007-12-11 09:32:34 -080093 xdst->u.dst.dev = dev;
94 dev_hold(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
Herbert Xu25ee3282007-12-11 09:32:34 -080096 xdst->u.rt.idev = in_dev_get(dev);
97 if (!xdst->u.rt.idev)
98 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099
Herbert Xu25ee3282007-12-11 09:32:34 -0800100 xdst->u.rt.peer = rt->peer;
101 if (rt->peer)
102 atomic_inc(&rt->peer->refcnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
Herbert Xu25ee3282007-12-11 09:32:34 -0800104 /* Sheit... I remember I did this right. Apparently,
105 * it was magically lost, so this code needs audit */
106 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
107 RTCF_LOCAL);
108 xdst->u.rt.rt_type = rt->rt_type;
109 xdst->u.rt.rt_src = rt->rt_src;
110 xdst->u.rt.rt_dst = rt->rt_dst;
111 xdst->u.rt.rt_gateway = rt->rt_gateway;
112 xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
Miika Komu43372262007-02-06 14:27:32 -0800113
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115}
116
117static void
Herbert Xud5422ef2007-12-12 10:44:16 -0800118_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
Arnaldo Carvalho de Meloeddc9ec2007-04-20 22:47:35 -0700120 struct iphdr *iph = ip_hdr(skb);
Arnaldo Carvalho de Melod56f90a2007-04-10 20:50:43 -0700121 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
123 memset(fl, 0, sizeof(struct flowi));
124 if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
125 switch (iph->protocol) {
126 case IPPROTO_UDP:
Gerrit Renkerba4e58e2006-11-27 11:10:57 -0800127 case IPPROTO_UDPLITE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 case IPPROTO_TCP:
129 case IPPROTO_SCTP:
Patrick McHardy9e999992005-12-19 14:03:46 -0800130 case IPPROTO_DCCP:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
Al Viro8c689a62006-11-08 00:20:21 -0800132 __be16 *ports = (__be16 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133
Herbert Xud5422ef2007-12-12 10:44:16 -0800134 fl->fl_ip_sport = ports[!!reverse];
135 fl->fl_ip_dport = ports[!reverse];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 }
137 break;
138
139 case IPPROTO_ICMP:
140 if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
141 u8 *icmp = xprth;
142
143 fl->fl_icmp_type = icmp[0];
144 fl->fl_icmp_code = icmp[1];
145 }
146 break;
147
148 case IPPROTO_ESP:
149 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
Al Viro4324a172006-09-27 18:49:07 -0700150 __be32 *ehdr = (__be32 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
152 fl->fl_ipsec_spi = ehdr[0];
153 }
154 break;
155
156 case IPPROTO_AH:
157 if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
Al Viro4324a172006-09-27 18:49:07 -0700158 __be32 *ah_hdr = (__be32*)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159
160 fl->fl_ipsec_spi = ah_hdr[1];
161 }
162 break;
163
164 case IPPROTO_COMP:
165 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
Al Viro4324a172006-09-27 18:49:07 -0700166 __be16 *ipcomp_hdr = (__be16 *)xprth;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167
Alexey Dobriyan4195f812006-05-22 16:53:22 -0700168 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 }
170 break;
171 default:
172 fl->fl_ipsec_spi = 0;
173 break;
Stephen Hemminger3ff50b72007-04-20 17:09:22 -0700174 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 }
176 fl->proto = iph->protocol;
Herbert Xud5422ef2007-12-12 10:44:16 -0800177 fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
178 fl->fl4_src = reverse ? iph->daddr : iph->saddr;
Herbert Xu4da30892006-02-23 16:19:26 -0800179 fl->fl4_tos = iph->tos;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180}
181
182static inline int xfrm4_garbage_collect(void)
183{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 xfrm4_policy_afinfo.garbage_collect();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
186}
187
188static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
189{
190 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
191 struct dst_entry *path = xdst->route;
192
193 path->ops->update_pmtu(path, mtu);
194}
195
Herbert Xuaabc9762005-05-03 16:27:10 -0700196static void xfrm4_dst_destroy(struct dst_entry *dst)
197{
198 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
199
200 if (likely(xdst->u.rt.idev))
201 in_dev_put(xdst->u.rt.idev);
Herbert Xued3e37d2007-10-17 21:34:46 -0700202 if (likely(xdst->u.rt.peer))
David S. Miller26db1672006-12-06 23:45:15 -0800203 inet_putpeer(xdst->u.rt.peer);
Herbert Xuaabc9762005-05-03 16:27:10 -0700204 xfrm_dst_destroy(xdst);
205}
206
207static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
208 int unregister)
209{
210 struct xfrm_dst *xdst;
211
212 if (!unregister)
213 return;
214
215 xdst = (struct xfrm_dst *)dst;
216 if (xdst->u.rt.idev->dev == dev) {
Denis V. Lunev5a3e55d2007-12-07 00:38:10 -0800217 struct in_device *loopback_idev =
218 in_dev_get(dev->nd_net->loopback_dev);
Herbert Xuaabc9762005-05-03 16:27:10 -0700219 BUG_ON(!loopback_idev);
220
221 do {
222 in_dev_put(xdst->u.rt.idev);
223 xdst->u.rt.idev = loopback_idev;
224 in_dev_hold(loopback_idev);
225 xdst = (struct xfrm_dst *)xdst->u.dst.child;
226 } while (xdst->u.dst.xfrm);
227
228 __in_dev_put(loopback_idev);
229 }
230
231 xfrm_dst_ifdown(dst, dev);
232}
233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234static struct dst_ops xfrm4_dst_ops = {
235 .family = AF_INET,
236 .protocol = __constant_htons(ETH_P_IP),
237 .gc = xfrm4_garbage_collect,
238 .update_pmtu = xfrm4_update_pmtu,
Herbert Xuaabc9762005-05-03 16:27:10 -0700239 .destroy = xfrm4_dst_destroy,
240 .ifdown = xfrm4_dst_ifdown,
Herbert Xu862b82c2007-11-13 21:43:11 -0800241 .local_out = __ip_local_out,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 .gc_thresh = 1024,
243 .entry_size = sizeof(struct xfrm_dst),
244};
245
246static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
247 .family = AF_INET,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 .dst_ops = &xfrm4_dst_ops,
249 .dst_lookup = xfrm4_dst_lookup,
Patrick McHardya1e59ab2006-09-19 12:57:34 -0700250 .get_saddr = xfrm4_get_saddr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 .find_bundle = __xfrm4_find_bundle,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 .decode_session = _decode_session4,
Herbert Xu25ee3282007-12-11 09:32:34 -0800253 .get_tos = xfrm4_get_tos,
254 .fill_dst = xfrm4_fill_dst,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255};
256
257static void __init xfrm4_policy_init(void)
258{
259 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
260}
261
262static void __exit xfrm4_policy_fini(void)
263{
264 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
265}
266
267void __init xfrm4_init(void)
268{
269 xfrm4_state_init();
270 xfrm4_policy_init();
271}
272