Merge branch 'for-linus' of git://gitorious.org/linux-omap-dss2/linux
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / xfrm4_policy.c
CommitLineData
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
66cdb3ca
HX
11#include <linux/err.h>
12#include <linux/kernel.h>
aabc9761 13#include <linux/inetdevice.h>
45ff5a3f 14#include <net/dst.h>
1da177e4
LT
15#include <net/xfrm.h>
16#include <net/ip.h>
17
1da177e4
LT
18static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
19
c5b3cf46
AD
20static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
21 xfrm_address_t *saddr,
66cdb3ca 22 xfrm_address_t *daddr)
1da177e4 23{
66cdb3ca 24 struct flowi fl = {
a1e59abf
PM
25 .nl_u = {
26 .ip4_u = {
66cdb3ca 27 .tos = tos,
a1e59abf
PM
28 .daddr = daddr->a4,
29 },
30 },
31 };
66cdb3ca
HX
32 struct dst_entry *dst;
33 struct rtable *rt;
34 int err;
a1e59abf 35
66cdb3ca
HX
36 if (saddr)
37 fl.fl4_src = saddr->a4;
38
c5b3cf46 39 err = __ip_route_output_key(net, &rt, &fl);
66cdb3ca
HX
40 dst = &rt->u.dst;
41 if (err)
42 dst = ERR_PTR(err);
43 return dst;
44}
45
fbda33b2
AD
46static int xfrm4_get_saddr(struct net *net,
47 xfrm_address_t *saddr, xfrm_address_t *daddr)
66cdb3ca
HX
48{
49 struct dst_entry *dst;
50 struct rtable *rt;
51
fbda33b2 52 dst = xfrm4_dst_lookup(net, 0, NULL, daddr);
66cdb3ca
HX
53 if (IS_ERR(dst))
54 return -EHOSTUNREACH;
55
56 rt = (struct rtable *)dst;
57 saddr->a4 = rt->rt_src;
58 dst_release(dst);
59 return 0;
a1e59abf
PM
60}
61
1da177e4
LT
62static struct dst_entry *
63__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
64{
65 struct dst_entry *dst;
66
67 read_lock_bh(&policy->lock);
68 for (dst = policy->bundles; dst; dst = dst->next) {
5a5f3a8d 69 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
1da177e4
LT
70 if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/
71 xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
e905a9ed
YH
72 xdst->u.rt.fl.fl4_src == fl->fl4_src &&
73 xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
5b368e61 74 xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
1da177e4
LT
75 dst_clone(dst);
76 break;
77 }
78 }
79 read_unlock_bh(&policy->lock);
80 return dst;
81}
82
25ee3286 83static int xfrm4_get_tos(struct flowi *fl)
1da177e4 84{
25ee3286
HX
85 return fl->fl4_tos;
86}
1da177e4 87
a1b05140
MN
88static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
89 int nfheader_len)
90{
91 return 0;
92}
93
25ee3286
HX
94static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
95{
96 struct rtable *rt = (struct rtable *)xdst->route;
1da177e4 97
25ee3286 98 xdst->u.rt.fl = rt->fl;
1da177e4 99
25ee3286
HX
100 xdst->u.dst.dev = dev;
101 dev_hold(dev);
43372262 102
25ee3286
HX
103 xdst->u.rt.idev = in_dev_get(dev);
104 if (!xdst->u.rt.idev)
105 return -ENODEV;
1da177e4 106
25ee3286
HX
107 xdst->u.rt.peer = rt->peer;
108 if (rt->peer)
109 atomic_inc(&rt->peer->refcnt);
66cdb3ca 110
25ee3286
HX
111 /* Sheit... I remember I did this right. Apparently,
112 * it was magically lost, so this code needs audit */
113 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
114 RTCF_LOCAL);
115 xdst->u.rt.rt_type = rt->rt_type;
116 xdst->u.rt.rt_src = rt->rt_src;
117 xdst->u.rt.rt_dst = rt->rt_dst;
118 xdst->u.rt.rt_gateway = rt->rt_gateway;
119 xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
1da177e4 120
1da177e4 121 return 0;
1da177e4
LT
122}
123
124static void
d5422efe 125_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
1da177e4 126{
eddc9ec5 127 struct iphdr *iph = ip_hdr(skb);
d56f90a7 128 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
1da177e4
LT
129
130 memset(fl, 0, sizeof(struct flowi));
131 if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
132 switch (iph->protocol) {
133 case IPPROTO_UDP:
ba4e58ec 134 case IPPROTO_UDPLITE:
1da177e4
LT
135 case IPPROTO_TCP:
136 case IPPROTO_SCTP:
9e999993 137 case IPPROTO_DCCP:
c615c9f3
WY
138 if (xprth + 4 < skb->data ||
139 pskb_may_pull(skb, xprth + 4 - skb->data)) {
8c689a6e 140 __be16 *ports = (__be16 *)xprth;
1da177e4 141
d5422efe
HX
142 fl->fl_ip_sport = ports[!!reverse];
143 fl->fl_ip_dport = ports[!reverse];
1da177e4
LT
144 }
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)) {
4324a174 158 __be32 *ehdr = (__be32 *)xprth;
1da177e4
LT
159
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)) {
4324a174 166 __be32 *ah_hdr = (__be32*)xprth;
1da177e4
LT
167
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)) {
4324a174 174 __be16 *ipcomp_hdr = (__be16 *)xprth;
1da177e4 175
4195f814 176 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
1da177e4
LT
177 }
178 break;
179 default:
180 fl->fl_ipsec_spi = 0;
181 break;
3ff50b79 182 }
1da177e4
LT
183 }
184 fl->proto = iph->protocol;
d5422efe
HX
185 fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
186 fl->fl4_src = reverse ? iph->daddr : iph->saddr;
4da3089f 187 fl->fl4_tos = iph->tos;
1da177e4
LT
188}
189
569d3645 190static inline int xfrm4_garbage_collect(struct dst_ops *ops)
1da177e4 191{
d7c7544c
AD
192 struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops);
193
194 xfrm4_policy_afinfo.garbage_collect(net);
195 return (atomic_read(&ops->entries) > ops->gc_thresh * 2);
1da177e4
LT
196}
197
198static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
199{
200 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
201 struct dst_entry *path = xdst->route;
202
203 path->ops->update_pmtu(path, mtu);
204}
205
aabc9761
HX
206static void xfrm4_dst_destroy(struct dst_entry *dst)
207{
208 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
209
210 if (likely(xdst->u.rt.idev))
211 in_dev_put(xdst->u.rt.idev);
ed3e37dd 212 if (likely(xdst->u.rt.peer))
26db1677 213 inet_putpeer(xdst->u.rt.peer);
aabc9761
HX
214 xfrm_dst_destroy(xdst);
215}
216
217static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
218 int unregister)
219{
220 struct xfrm_dst *xdst;
221
222 if (!unregister)
223 return;
224
225 xdst = (struct xfrm_dst *)dst;
226 if (xdst->u.rt.idev->dev == dev) {
5a3e55d6 227 struct in_device *loopback_idev =
c346dca1 228 in_dev_get(dev_net(dev)->loopback_dev);
aabc9761
HX
229 BUG_ON(!loopback_idev);
230
231 do {
232 in_dev_put(xdst->u.rt.idev);
233 xdst->u.rt.idev = loopback_idev;
234 in_dev_hold(loopback_idev);
235 xdst = (struct xfrm_dst *)xdst->u.dst.child;
236 } while (xdst->u.dst.xfrm);
237
238 __in_dev_put(loopback_idev);
239 }
240
241 xfrm_dst_ifdown(dst, dev);
242}
243
1da177e4
LT
244static struct dst_ops xfrm4_dst_ops = {
245 .family = AF_INET,
09640e63 246 .protocol = cpu_to_be16(ETH_P_IP),
1da177e4
LT
247 .gc = xfrm4_garbage_collect,
248 .update_pmtu = xfrm4_update_pmtu,
aabc9761
HX
249 .destroy = xfrm4_dst_destroy,
250 .ifdown = xfrm4_dst_ifdown,
862b82c6 251 .local_out = __ip_local_out,
1da177e4 252 .gc_thresh = 1024,
e2422970 253 .entries = ATOMIC_INIT(0),
1da177e4
LT
254};
255
256static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
257 .family = AF_INET,
1da177e4
LT
258 .dst_ops = &xfrm4_dst_ops,
259 .dst_lookup = xfrm4_dst_lookup,
a1e59abf 260 .get_saddr = xfrm4_get_saddr,
1da177e4 261 .find_bundle = __xfrm4_find_bundle,
1da177e4 262 .decode_session = _decode_session4,
25ee3286 263 .get_tos = xfrm4_get_tos,
a1b05140 264 .init_path = xfrm4_init_path,
25ee3286 265 .fill_dst = xfrm4_fill_dst,
1da177e4
LT
266};
267
f816700a 268#ifdef CONFIG_SYSCTL
a44a4a00
NH
269static struct ctl_table xfrm4_policy_table[] = {
270 {
a44a4a00 271 .procname = "xfrm4_gc_thresh",
d7c7544c 272 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
a44a4a00
NH
273 .maxlen = sizeof(int),
274 .mode = 0644,
275 .proc_handler = proc_dointvec,
276 },
277 { }
278};
279
280static struct ctl_table_header *sysctl_hdr;
f816700a 281#endif
a44a4a00 282
1da177e4
LT
283static void __init xfrm4_policy_init(void)
284{
285 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
286}
287
288static void __exit xfrm4_policy_fini(void)
289{
f816700a 290#ifdef CONFIG_SYSCTL
a44a4a00
NH
291 if (sysctl_hdr)
292 unregister_net_sysctl_table(sysctl_hdr);
f816700a 293#endif
1da177e4
LT
294 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
295}
296
a33bc5c1 297void __init xfrm4_init(int rt_max_size)
1da177e4 298{
a33bc5c1
NH
299 /*
300 * Select a default value for the gc_thresh based on the main route
301 * table hash size. It seems to me the worst case scenario is when
302 * we have ipsec operating in transport mode, in which we create a
303 * dst_entry per socket. The xfrm gc algorithm starts trying to remove
304 * entries at gc_thresh, and prevents new allocations as 2*gc_thresh
305 * so lets set an initial xfrm gc_thresh value at the rt_max_size/2.
306 * That will let us store an ipsec connection per route table entry,
307 * and start cleaning when were 1/2 full
308 */
309 xfrm4_dst_ops.gc_thresh = rt_max_size/2;
d7c7544c
AD
310
311 xfrm4_state_init();
312 xfrm4_policy_init();
f816700a 313#ifdef CONFIG_SYSCTL
a44a4a00
NH
314 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
315 xfrm4_policy_table);
f816700a 316#endif
1da177e4
LT
317}
318