1 /*
2 * xfrm6_policy.c: based on xfrm4_policy.c
3 *
4 * Authors:
5 * Mitsuru KANDA @USAGI
6 * Kazunori MIYAZAWA @USAGI
7 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
8 * IPv6 support
9 * YOSHIFUJI Hideaki
10 * Split up af-specific portion
11 *
12 */
13
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/netdevice.h>
17 #include <net/addrconf.h>
18 #include <net/dst.h>
19 #include <net/xfrm.h>
20 #include <net/ip.h>
21 #include <net/ipv6.h>
22 #include <net/ip6_route.h>
23 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
24 #include <net/mip6.h>
25 #endif
26
27 static struct xfrm_policy_afinfo xfrm6_policy_afinfo;
28
xfrm6_dst_lookup(struct net * net,int tos,const xfrm_address_t * saddr,const xfrm_address_t * daddr)29 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos,
30 const xfrm_address_t *saddr,
31 const xfrm_address_t *daddr)
32 {
33 struct flowi6 fl6;
34 struct dst_entry *dst;
35 int err;
36
37 memset(&fl6, 0, sizeof(fl6));
38 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
39 if (saddr)
40 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));
41
42 dst = ip6_route_output(net, NULL, &fl6);
43
44 err = dst->error;
45 if (dst->error) {
46 dst_release(dst);
47 dst = ERR_PTR(err);
48 }
49
50 return dst;
51 }
52
xfrm6_get_saddr(struct net * net,xfrm_address_t * saddr,xfrm_address_t * daddr)53 static int xfrm6_get_saddr(struct net *net,
54 xfrm_address_t *saddr, xfrm_address_t *daddr)
55 {
56 struct dst_entry *dst;
57 struct net_device *dev;
58
59 dst = xfrm6_dst_lookup(net, 0, NULL, daddr);
60 if (IS_ERR(dst))
61 return -EHOSTUNREACH;
62
63 dev = ip6_dst_idev(dst)->dev;
64 ipv6_dev_get_saddr(dev_net(dev), dev,
65 (struct in6_addr *)&daddr->a6, 0,
66 (struct in6_addr *)&saddr->a6);
67 dst_release(dst);
68 return 0;
69 }
70
xfrm6_get_tos(const struct flowi * fl)71 static int xfrm6_get_tos(const struct flowi *fl)
72 {
73 return 0;
74 }
75
xfrm6_init_path(struct xfrm_dst * path,struct dst_entry * dst,int nfheader_len)76 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst,
77 int nfheader_len)
78 {
79 if (dst->ops->family == AF_INET6) {
80 struct rt6_info *rt = (struct rt6_info*)dst;
81 if (rt->rt6i_node)
82 path->path_cookie = rt->rt6i_node->fn_sernum;
83 }
84
85 path->u.rt6.rt6i_nfheader_len = nfheader_len;
86
87 return 0;
88 }
89
xfrm6_fill_dst(struct xfrm_dst * xdst,struct net_device * dev,const struct flowi * fl)90 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
91 const struct flowi *fl)
92 {
93 struct rt6_info *rt = (struct rt6_info*)xdst->route;
94
95 xdst->u.dst.dev = dev;
96 dev_hold(dev);
97
98 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
99 if (!xdst->u.rt6.rt6i_idev) {
100 dev_put(dev);
101 return -ENODEV;
102 }
103
104 xdst->u.rt6.rt6i_peer = rt->rt6i_peer;
105 if (rt->rt6i_peer)
106 atomic_inc(&rt->rt6i_peer->refcnt);
107
108 /* Sheit... I remember I did this right. Apparently,
109 * it was magically lost, so this code needs audit */
110 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
111 RTF_LOCAL);
112 xdst->u.rt6.rt6i_metric = rt->rt6i_metric;
113 xdst->u.rt6.rt6i_node = rt->rt6i_node;
114 if (rt->rt6i_node)
115 xdst->route_cookie = rt->rt6i_node->fn_sernum;
116 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
117 xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
118 xdst->u.rt6.rt6i_src = rt->rt6i_src;
119
120 return 0;
121 }
122
123 static inline void
_decode_session6(struct sk_buff * skb,struct flowi * fl,int reverse)124 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
125 {
126 struct flowi6 *fl6 = &fl->u.ip6;
127 int onlyproto = 0;
128 u16 offset = skb_network_header_len(skb);
129 const struct ipv6hdr *hdr = ipv6_hdr(skb);
130 struct ipv6_opt_hdr *exthdr;
131 const unsigned char *nh = skb_network_header(skb);
132 u8 nexthdr = nh[IP6CB(skb)->nhoff];
133
134 memset(fl6, 0, sizeof(struct flowi6));
135 fl6->flowi6_mark = skb->mark;
136
137 fl6->daddr = reverse ? hdr->saddr : hdr->daddr;
138 fl6->saddr = reverse ? hdr->daddr : hdr->saddr;
139
140 while (nh + offset + 1 < skb->data ||
141 pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
142 nh = skb_network_header(skb);
143 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
144
145 switch (nexthdr) {
146 case NEXTHDR_FRAGMENT:
147 onlyproto = 1;
148 case NEXTHDR_ROUTING:
149 case NEXTHDR_HOP:
150 case NEXTHDR_DEST:
151 offset += ipv6_optlen(exthdr);
152 nexthdr = exthdr->nexthdr;
153 exthdr = (struct ipv6_opt_hdr *)(nh + offset);
154 break;
155
156 case IPPROTO_UDP:
157 case IPPROTO_UDPLITE:
158 case IPPROTO_TCP:
159 case IPPROTO_SCTP:
160 case IPPROTO_DCCP:
161 if (!onlyproto && (nh + offset + 4 < skb->data ||
162 pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
163 __be16 *ports = (__be16 *)exthdr;
164
165 fl6->fl6_sport = ports[!!reverse];
166 fl6->fl6_dport = ports[!reverse];
167 }
168 fl6->flowi6_proto = nexthdr;
169 return;
170
171 case IPPROTO_ICMPV6:
172 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) {
173 u8 *icmp = (u8 *)exthdr;
174
175 fl6->fl6_icmp_type = icmp[0];
176 fl6->fl6_icmp_code = icmp[1];
177 }
178 fl6->flowi6_proto = nexthdr;
179 return;
180
181 #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
182 case IPPROTO_MH:
183 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) {
184 struct ip6_mh *mh;
185 mh = (struct ip6_mh *)exthdr;
186
187 fl6->fl6_mh_type = mh->ip6mh_type;
188 }
189 fl6->flowi6_proto = nexthdr;
190 return;
191 #endif
192
193 /* XXX Why are there these headers? */
194 case IPPROTO_AH:
195 case IPPROTO_ESP:
196 case IPPROTO_COMP:
197 default:
198 fl6->fl6_ipsec_spi = 0;
199 fl6->flowi6_proto = nexthdr;
200 return;
201 }
202 }
203 }
204
xfrm6_garbage_collect(struct dst_ops * ops)205 static inline int xfrm6_garbage_collect(struct dst_ops *ops)
206 {
207 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops);
208
209 xfrm6_policy_afinfo.garbage_collect(net);
210 return dst_entries_get_fast(ops) > ops->gc_thresh * 2;
211 }
212
xfrm6_update_pmtu(struct dst_entry * dst,u32 mtu)213 static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu)
214 {
215 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
216 struct dst_entry *path = xdst->route;
217
218 path->ops->update_pmtu(path, mtu);
219 }
220
xfrm6_dst_destroy(struct dst_entry * dst)221 static void xfrm6_dst_destroy(struct dst_entry *dst)
222 {
223 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
224
225 if (likely(xdst->u.rt6.rt6i_idev))
226 in6_dev_put(xdst->u.rt6.rt6i_idev);
227 dst_destroy_metrics_generic(dst);
228 if (likely(xdst->u.rt6.rt6i_peer))
229 inet_putpeer(xdst->u.rt6.rt6i_peer);
230 xfrm_dst_destroy(xdst);
231 }
232
xfrm6_dst_ifdown(struct dst_entry * dst,struct net_device * dev,int unregister)233 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
234 int unregister)
235 {
236 struct xfrm_dst *xdst;
237
238 if (!unregister)
239 return;
240
241 xdst = (struct xfrm_dst *)dst;
242 if (xdst->u.rt6.rt6i_idev->dev == dev) {
243 struct inet6_dev *loopback_idev =
244 in6_dev_get(dev_net(dev)->loopback_dev);
245 BUG_ON(!loopback_idev);
246
247 do {
248 in6_dev_put(xdst->u.rt6.rt6i_idev);
249 xdst->u.rt6.rt6i_idev = loopback_idev;
250 in6_dev_hold(loopback_idev);
251 xdst = (struct xfrm_dst *)xdst->u.dst.child;
252 } while (xdst->u.dst.xfrm);
253
254 __in6_dev_put(loopback_idev);
255 }
256
257 xfrm_dst_ifdown(dst, dev);
258 }
259
260 static struct dst_ops xfrm6_dst_ops = {
261 .family = AF_INET6,
262 .protocol = cpu_to_be16(ETH_P_IPV6),
263 .gc = xfrm6_garbage_collect,
264 .update_pmtu = xfrm6_update_pmtu,
265 .cow_metrics = dst_cow_metrics_generic,
266 .destroy = xfrm6_dst_destroy,
267 .ifdown = xfrm6_dst_ifdown,
268 .local_out = __ip6_local_out,
269 .gc_thresh = 1024,
270 };
271
272 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
273 .family = AF_INET6,
274 .dst_ops = &xfrm6_dst_ops,
275 .dst_lookup = xfrm6_dst_lookup,
276 .get_saddr = xfrm6_get_saddr,
277 .decode_session = _decode_session6,
278 .get_tos = xfrm6_get_tos,
279 .init_path = xfrm6_init_path,
280 .fill_dst = xfrm6_fill_dst,
281 .blackhole_route = ip6_blackhole_route,
282 };
283
xfrm6_policy_init(void)284 static int __init xfrm6_policy_init(void)
285 {
286 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo);
287 }
288
xfrm6_policy_fini(void)289 static void xfrm6_policy_fini(void)
290 {
291 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
292 }
293
294 #ifdef CONFIG_SYSCTL
295 static struct ctl_table xfrm6_policy_table[] = {
296 {
297 .procname = "xfrm6_gc_thresh",
298 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
299 .maxlen = sizeof(int),
300 .mode = 0644,
301 .proc_handler = proc_dointvec,
302 },
303 { }
304 };
305
306 static struct ctl_table_header *sysctl_hdr;
307 #endif
308
xfrm6_init(void)309 int __init xfrm6_init(void)
310 {
311 int ret;
312 unsigned int gc_thresh;
313
314 /*
315 * We need a good default value for the xfrm6 gc threshold.
316 * In ipv4 we set it to the route hash table size * 8, which
317 * is half the size of the maximaum route cache for ipv4. It
318 * would be good to do the same thing for v6, except the table is
319 * constructed differently here. Here each table for a net namespace
320 * can have FIB_TABLE_HASHSZ entries, so lets go with the same
321 * computation that we used for ipv4 here. Also, lets keep the initial
322 * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults
323 * to that as a minimum as well
324 */
325 gc_thresh = FIB6_TABLE_HASHSZ * 8;
326 xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh;
327 dst_entries_init(&xfrm6_dst_ops);
328
329 ret = xfrm6_policy_init();
330 if (ret) {
331 dst_entries_destroy(&xfrm6_dst_ops);
332 goto out;
333 }
334 ret = xfrm6_state_init();
335 if (ret)
336 goto out_policy;
337
338 #ifdef CONFIG_SYSCTL
339 sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path,
340 xfrm6_policy_table);
341 #endif
342 out:
343 return ret;
344 out_policy:
345 xfrm6_policy_fini();
346 goto out;
347 }
348
xfrm6_fini(void)349 void xfrm6_fini(void)
350 {
351 #ifdef CONFIG_SYSCTL
352 if (sysctl_hdr)
353 unregister_net_sysctl_table(sysctl_hdr);
354 #endif
355 //xfrm6_input_fini();
356 xfrm6_policy_fini();
357 xfrm6_state_fini();
358 dst_entries_destroy(&xfrm6_dst_ops);
359 }
360