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11#include <linux/err.h>
12#include <linux/kernel.h>
13#include <linux/inetdevice.h>
14#include <net/dst.h>
15#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
21static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
22 xfrm_address_t *saddr,
23 xfrm_address_t *daddr)
24{
25 struct flowi fl = {
26 .nl_u = {
27 .ip4_u = {
28 .tos = tos,
29 .daddr = daddr->a4,
30 },
31 },
32 };
33 struct dst_entry *dst;
34 struct rtable *rt;
35 int err;
36
37 if (saddr)
38 fl.fl4_src = saddr->a4;
39
40 err = __ip_route_output_key(net, &rt, &fl);
41 dst = &rt->u.dst;
42 if (err)
43 dst = ERR_PTR(err);
44 return dst;
45}
46
47static int xfrm4_get_saddr(struct net *net,
48 xfrm_address_t *saddr, xfrm_address_t *daddr)
49{
50 struct dst_entry *dst;
51 struct rtable *rt;
52
53 dst = xfrm4_dst_lookup(net, 0, NULL, daddr);
54 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;
61}
62
63static 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) {
70 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
71 if (xdst->u.rt.fl.oif == fl->oif &&
72 xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
73 xdst->u.rt.fl.fl4_src == fl->fl4_src &&
74 xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
75 xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
76 dst_clone(dst);
77 break;
78 }
79 }
80 read_unlock_bh(&policy->lock);
81 return dst;
82}
83
84static int xfrm4_get_tos(struct flowi *fl)
85{
86 return fl->fl4_tos;
87}
88
89static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
90 int nfheader_len)
91{
92 return 0;
93}
94
95static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
96{
97 struct rtable *rt = (struct rtable *)xdst->route;
98
99 xdst->u.rt.fl = rt->fl;
100
101 xdst->u.dst.dev = dev;
102 dev_hold(dev);
103
104 xdst->u.rt.idev = in_dev_get(dev);
105 if (!xdst->u.rt.idev)
106 return -ENODEV;
107
108 xdst->u.rt.peer = rt->peer;
109 if (rt->peer)
110 atomic_inc(&rt->peer->refcnt);
111
112
113
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;
121
122 return 0;
123}
124
125static void
126_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
127{
128 struct iphdr *iph = ip_hdr(skb);
129 u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
130
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:
135 case IPPROTO_UDPLITE:
136 case IPPROTO_TCP:
137 case IPPROTO_SCTP:
138 case IPPROTO_DCCP:
139 if (xprth + 4 < skb->data ||
140 pskb_may_pull(skb, xprth + 4 - skb->data)) {
141 __be16 *ports = (__be16 *)xprth;
142
143 fl->fl_ip_sport = ports[!!reverse];
144 fl->fl_ip_dport = ports[!reverse];
145 }
146 break;
147
148 case IPPROTO_ICMP:
149 if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
150 u8 *icmp = xprth;
151
152 fl->fl_icmp_type = icmp[0];
153 fl->fl_icmp_code = icmp[1];
154 }
155 break;
156
157 case IPPROTO_ESP:
158 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
159 __be32 *ehdr = (__be32 *)xprth;
160
161 fl->fl_ipsec_spi = ehdr[0];
162 }
163 break;
164
165 case IPPROTO_AH:
166 if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
167 __be32 *ah_hdr = (__be32*)xprth;
168
169 fl->fl_ipsec_spi = ah_hdr[1];
170 }
171 break;
172
173 case IPPROTO_COMP:
174 if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
175 __be16 *ipcomp_hdr = (__be16 *)xprth;
176
177 fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
178 }
179 break;
180 default:
181 fl->fl_ipsec_spi = 0;
182 break;
183 }
184 }
185 fl->proto = iph->protocol;
186 fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
187 fl->fl4_src = reverse ? iph->daddr : iph->saddr;
188 fl->fl4_tos = iph->tos;
189}
190
191static inline int xfrm4_garbage_collect(struct dst_ops *ops)
192{
193 xfrm4_policy_afinfo.garbage_collect(&init_net);
194 return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
195}
196
197static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
198{
199 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
200 struct dst_entry *path = xdst->route;
201
202 path->ops->update_pmtu(path, mtu);
203}
204
205static void xfrm4_dst_destroy(struct dst_entry *dst)
206{
207 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
208
209 if (likely(xdst->u.rt.idev))
210 in_dev_put(xdst->u.rt.idev);
211 if (likely(xdst->u.rt.peer))
212 inet_putpeer(xdst->u.rt.peer);
213 xfrm_dst_destroy(xdst);
214}
215
216static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
217 int unregister)
218{
219 struct xfrm_dst *xdst;
220
221 if (!unregister)
222 return;
223
224 xdst = (struct xfrm_dst *)dst;
225 if (xdst->u.rt.idev->dev == dev) {
226 struct in_device *loopback_idev =
227 in_dev_get(dev_net(dev)->loopback_dev);
228 BUG_ON(!loopback_idev);
229
230 do {
231 in_dev_put(xdst->u.rt.idev);
232 xdst->u.rt.idev = loopback_idev;
233 in_dev_hold(loopback_idev);
234 xdst = (struct xfrm_dst *)xdst->u.dst.child;
235 } while (xdst->u.dst.xfrm);
236
237 __in_dev_put(loopback_idev);
238 }
239
240 xfrm_dst_ifdown(dst, dev);
241}
242
243static struct dst_ops xfrm4_dst_ops = {
244 .family = AF_INET,
245 .protocol = cpu_to_be16(ETH_P_IP),
246 .gc = xfrm4_garbage_collect,
247 .update_pmtu = xfrm4_update_pmtu,
248 .destroy = xfrm4_dst_destroy,
249 .ifdown = xfrm4_dst_ifdown,
250 .local_out = __ip_local_out,
251 .gc_thresh = 1024,
252 .entries = ATOMIC_INIT(0),
253};
254
255static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
256 .family = AF_INET,
257 .dst_ops = &xfrm4_dst_ops,
258 .dst_lookup = xfrm4_dst_lookup,
259 .get_saddr = xfrm4_get_saddr,
260 .find_bundle = __xfrm4_find_bundle,
261 .decode_session = _decode_session4,
262 .get_tos = xfrm4_get_tos,
263 .init_path = xfrm4_init_path,
264 .fill_dst = xfrm4_fill_dst,
265};
266
267#ifdef CONFIG_SYSCTL
268static struct ctl_table xfrm4_policy_table[] = {
269 {
270 .ctl_name = CTL_UNNUMBERED,
271 .procname = "xfrm4_gc_thresh",
272 .data = &xfrm4_dst_ops.gc_thresh,
273 .maxlen = sizeof(int),
274 .mode = 0644,
275 .proc_handler = proc_dointvec,
276 },
277 { }
278};
279
280static struct ctl_table_header *sysctl_hdr;
281#endif
282
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{
290#ifdef CONFIG_SYSCTL
291 if (sysctl_hdr)
292 unregister_net_sysctl_table(sysctl_hdr);
293#endif
294 xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
295}
296
297void __init xfrm4_init(int rt_max_size)
298{
299 xfrm4_state_init();
300 xfrm4_policy_init();
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311 xfrm4_dst_ops.gc_thresh = rt_max_size/2;
312#ifdef CONFIG_SYSCTL
313 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
314 xfrm4_policy_table);
315#endif
316}
317
318
