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[net-next-2.6.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);
d8d1f30b 40 dst = &rt->dst;
66cdb3ca
HX
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
25ee3286 62static int xfrm4_get_tos(struct flowi *fl)
1da177e4 63{
94e22389 64 return IPTOS_RT_MASK & fl->fl4_tos; /* Strip ECN bits */
25ee3286 65}
1da177e4 66
a1b05140
MN
67static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
68 int nfheader_len)
69{
70 return 0;
71}
72
87c1e12b
HX
73static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
74 struct flowi *fl)
25ee3286
HX
75{
76 struct rtable *rt = (struct rtable *)xdst->route;
1da177e4 77
87c1e12b 78 xdst->u.rt.fl = *fl;
1da177e4 79
25ee3286
HX
80 xdst->u.dst.dev = dev;
81 dev_hold(dev);
43372262 82
25ee3286
HX
83 xdst->u.rt.idev = in_dev_get(dev);
84 if (!xdst->u.rt.idev)
85 return -ENODEV;
1da177e4 86
25ee3286
HX
87 xdst->u.rt.peer = rt->peer;
88 if (rt->peer)
89 atomic_inc(&rt->peer->refcnt);
66cdb3ca 90
25ee3286
HX
91 /* Sheit... I remember I did this right. Apparently,
92 * it was magically lost, so this code needs audit */
93 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
94 RTCF_LOCAL);
95 xdst->u.rt.rt_type = rt->rt_type;
96 xdst->u.rt.rt_src = rt->rt_src;
97 xdst->u.rt.rt_dst = rt->rt_dst;
98 xdst->u.rt.rt_gateway = rt->rt_gateway;
99 xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
1da177e4 100
1da177e4 101 return 0;
1da177e4
LT
102}
103
104static void
d5422efe 105_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
1da177e4 106{
eddc9ec5 107 struct iphdr *iph = ip_hdr(skb);
d56f90a7 108 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
1da177e4
LT
109
110 memset(fl, 0, sizeof(struct flowi));
44b451f1
PK
111 fl->mark = skb->mark;
112
1da177e4
LT
113 if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
114 switch (iph->protocol) {
115 case IPPROTO_UDP:
ba4e58ec 116 case IPPROTO_UDPLITE:
1da177e4
LT
117 case IPPROTO_TCP:
118 case IPPROTO_SCTP:
9e999993 119 case IPPROTO_DCCP:
c615c9f3
WY
120 if (xprth + 4 < skb->data ||
121 pskb_may_pull(skb, xprth + 4 - skb->data)) {
8c689a6e 122 __be16 *ports = (__be16 *)xprth;
1da177e4 123
d5422efe
HX
124 fl->fl_ip_sport = ports[!!reverse];
125 fl->fl_ip_dport = ports[!reverse];
1da177e4
LT
126 }
127 break;
128
129 case IPPROTO_ICMP:
130 if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
131 u8 *icmp = xprth;
132
133 fl->fl_icmp_type = icmp[0];
134 fl->fl_icmp_code = icmp[1];
135 }
136 break;
137
138 case IPPROTO_ESP:
139 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
4324a174 140 __be32 *ehdr = (__be32 *)xprth;
1da177e4
LT
141
142 fl->fl_ipsec_spi = ehdr[0];
143 }
144 break;
145
146 case IPPROTO_AH:
147 if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
4324a174 148 __be32 *ah_hdr = (__be32*)xprth;
1da177e4
LT
149
150 fl->fl_ipsec_spi = ah_hdr[1];
151 }
152 break;
153
154 case IPPROTO_COMP:
155 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
4324a174 156 __be16 *ipcomp_hdr = (__be16 *)xprth;
1da177e4 157
4195f814 158 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
1da177e4
LT
159 }
160 break;
161 default:
162 fl->fl_ipsec_spi = 0;
163 break;
3ff50b79 164 }
1da177e4
LT
165 }
166 fl->proto = iph->protocol;
d5422efe
HX
167 fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
168 fl->fl4_src = reverse ? iph->daddr : iph->saddr;
4da3089f 169 fl->fl4_tos = iph->tos;
1da177e4
LT
170}
171
569d3645 172static inline int xfrm4_garbage_collect(struct dst_ops *ops)
1da177e4 173{
d7c7544c
AD
174 struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops);
175
176 xfrm4_policy_afinfo.garbage_collect(net);
177 return (atomic_read(&ops->entries) > ops->gc_thresh * 2);
1da177e4
LT
178}
179
180static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
181{
182 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
183 struct dst_entry *path = xdst->route;
184
185 path->ops->update_pmtu(path, mtu);
186}
187
aabc9761
HX
188static void xfrm4_dst_destroy(struct dst_entry *dst)
189{
190 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
191
192 if (likely(xdst->u.rt.idev))
193 in_dev_put(xdst->u.rt.idev);
ed3e37dd 194 if (likely(xdst->u.rt.peer))
26db1677 195 inet_putpeer(xdst->u.rt.peer);
aabc9761
HX
196 xfrm_dst_destroy(xdst);
197}
198
199static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
200 int unregister)
201{
202 struct xfrm_dst *xdst;
203
204 if (!unregister)
205 return;
206
207 xdst = (struct xfrm_dst *)dst;
208 if (xdst->u.rt.idev->dev == dev) {
5a3e55d6 209 struct in_device *loopback_idev =
c346dca1 210 in_dev_get(dev_net(dev)->loopback_dev);
aabc9761
HX
211 BUG_ON(!loopback_idev);
212
213 do {
214 in_dev_put(xdst->u.rt.idev);
215 xdst->u.rt.idev = loopback_idev;
216 in_dev_hold(loopback_idev);
217 xdst = (struct xfrm_dst *)xdst->u.dst.child;
218 } while (xdst->u.dst.xfrm);
219
220 __in_dev_put(loopback_idev);
221 }
222
223 xfrm_dst_ifdown(dst, dev);
224}
225
1da177e4
LT
226static struct dst_ops xfrm4_dst_ops = {
227 .family = AF_INET,
09640e63 228 .protocol = cpu_to_be16(ETH_P_IP),
1da177e4
LT
229 .gc = xfrm4_garbage_collect,
230 .update_pmtu = xfrm4_update_pmtu,
aabc9761
HX
231 .destroy = xfrm4_dst_destroy,
232 .ifdown = xfrm4_dst_ifdown,
862b82c6 233 .local_out = __ip_local_out,
1da177e4 234 .gc_thresh = 1024,
e2422970 235 .entries = ATOMIC_INIT(0),
1da177e4
LT
236};
237
238static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
239 .family = AF_INET,
1da177e4
LT
240 .dst_ops = &xfrm4_dst_ops,
241 .dst_lookup = xfrm4_dst_lookup,
a1e59abf 242 .get_saddr = xfrm4_get_saddr,
1da177e4 243 .decode_session = _decode_session4,
25ee3286 244 .get_tos = xfrm4_get_tos,
a1b05140 245 .init_path = xfrm4_init_path,
25ee3286 246 .fill_dst = xfrm4_fill_dst,
1da177e4
LT
247};
248
f816700a 249#ifdef CONFIG_SYSCTL
a44a4a00
NH
250static struct ctl_table xfrm4_policy_table[] = {
251 {
a44a4a00 252 .procname = "xfrm4_gc_thresh",
d7c7544c 253 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
a44a4a00
NH
254 .maxlen = sizeof(int),
255 .mode = 0644,
256 .proc_handler = proc_dointvec,
257 },
258 { }
259};
260
261static struct ctl_table_header *sysctl_hdr;
f816700a 262#endif
a44a4a00 263
1da177e4
LT
264static void __init xfrm4_policy_init(void)
265{
266 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
267}
268
269static void __exit xfrm4_policy_fini(void)
270{
f816700a 271#ifdef CONFIG_SYSCTL
a44a4a00
NH
272 if (sysctl_hdr)
273 unregister_net_sysctl_table(sysctl_hdr);
f816700a 274#endif
1da177e4
LT
275 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
276}
277
a33bc5c1 278void __init xfrm4_init(int rt_max_size)
1da177e4 279{
a33bc5c1
NH
280 /*
281 * Select a default value for the gc_thresh based on the main route
282 * table hash size. It seems to me the worst case scenario is when
283 * we have ipsec operating in transport mode, in which we create a
284 * dst_entry per socket. The xfrm gc algorithm starts trying to remove
285 * entries at gc_thresh, and prevents new allocations as 2*gc_thresh
286 * so lets set an initial xfrm gc_thresh value at the rt_max_size/2.
287 * That will let us store an ipsec connection per route table entry,
288 * and start cleaning when were 1/2 full
289 */
290 xfrm4_dst_ops.gc_thresh = rt_max_size/2;
d7c7544c
AD
291
292 xfrm4_state_init();
293 xfrm4_policy_init();
f816700a 294#ifdef CONFIG_SYSCTL
a44a4a00
NH
295 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
296 xfrm4_policy_table);
f816700a 297#endif
1da177e4
LT
298}
299