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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 | ||
29 | static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, | |
30 | xfrm_address_t *saddr, | |
31 | xfrm_address_t *daddr) | |
32 | { | |
33 | struct flowi fl = {}; | |
34 | struct dst_entry *dst; | |
35 | int err; | |
36 | ||
37 | memcpy(&fl.fl6_dst, daddr, sizeof(fl.fl6_dst)); | |
38 | if (saddr) | |
39 | memcpy(&fl.fl6_src, saddr, sizeof(fl.fl6_src)); | |
40 | ||
41 | dst = ip6_route_output(net, NULL, &fl); | |
42 | ||
43 | err = dst->error; | |
44 | if (dst->error) { | |
45 | dst_release(dst); | |
46 | dst = ERR_PTR(err); | |
47 | } | |
48 | ||
49 | return dst; | |
50 | } | |
51 | ||
52 | static int xfrm6_get_saddr(struct net *net, | |
53 | xfrm_address_t *saddr, xfrm_address_t *daddr) | |
54 | { | |
55 | struct dst_entry *dst; | |
56 | struct net_device *dev; | |
57 | ||
58 | dst = xfrm6_dst_lookup(net, 0, NULL, daddr); | |
59 | if (IS_ERR(dst)) | |
60 | return -EHOSTUNREACH; | |
61 | ||
62 | dev = ip6_dst_idev(dst)->dev; | |
63 | ipv6_dev_get_saddr(dev_net(dev), dev, | |
64 | (struct in6_addr *)&daddr->a6, 0, | |
65 | (struct in6_addr *)&saddr->a6); | |
66 | dst_release(dst); | |
67 | return 0; | |
68 | } | |
69 | ||
70 | static int xfrm6_get_tos(struct flowi *fl) | |
71 | { | |
72 | return 0; | |
73 | } | |
74 | ||
75 | static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, | |
76 | int nfheader_len) | |
77 | { | |
78 | if (dst->ops->family == AF_INET6) { | |
79 | struct rt6_info *rt = (struct rt6_info*)dst; | |
80 | if (rt->rt6i_node) | |
81 | path->path_cookie = rt->rt6i_node->fn_sernum; | |
82 | } | |
83 | ||
84 | path->u.rt6.rt6i_nfheader_len = nfheader_len; | |
85 | ||
86 | return 0; | |
87 | } | |
88 | ||
89 | static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, | |
90 | struct flowi *fl) | |
91 | { | |
92 | struct rt6_info *rt = (struct rt6_info*)xdst->route; | |
93 | ||
94 | xdst->u.dst.dev = dev; | |
95 | dev_hold(dev); | |
96 | ||
97 | xdst->u.rt6.rt6i_idev = in6_dev_get(dev); | |
98 | if (!xdst->u.rt6.rt6i_idev) | |
99 | return -ENODEV; | |
100 | ||
101 | xdst->u.rt6.rt6i_peer = rt->rt6i_peer; | |
102 | if (rt->rt6i_peer) | |
103 | atomic_inc(&rt->rt6i_peer->refcnt); | |
104 | ||
105 | /* Sheit... I remember I did this right. Apparently, | |
106 | * it was magically lost, so this code needs audit */ | |
107 | xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | | |
108 | RTF_LOCAL); | |
109 | xdst->u.rt6.rt6i_metric = rt->rt6i_metric; | |
110 | xdst->u.rt6.rt6i_node = rt->rt6i_node; | |
111 | if (rt->rt6i_node) | |
112 | xdst->route_cookie = rt->rt6i_node->fn_sernum; | |
113 | xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; | |
114 | xdst->u.rt6.rt6i_dst = rt->rt6i_dst; | |
115 | xdst->u.rt6.rt6i_src = rt->rt6i_src; | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
120 | static inline void | |
121 | _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) | |
122 | { | |
123 | int onlyproto = 0; | |
124 | u16 offset = skb_network_header_len(skb); | |
125 | struct ipv6hdr *hdr = ipv6_hdr(skb); | |
126 | struct ipv6_opt_hdr *exthdr; | |
127 | const unsigned char *nh = skb_network_header(skb); | |
128 | u8 nexthdr = nh[IP6CB(skb)->nhoff]; | |
129 | ||
130 | memset(fl, 0, sizeof(struct flowi)); | |
131 | fl->mark = skb->mark; | |
132 | ||
133 | ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr); | |
134 | ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr); | |
135 | ||
136 | while (nh + offset + 1 < skb->data || | |
137 | pskb_may_pull(skb, nh + offset + 1 - skb->data)) { | |
138 | nh = skb_network_header(skb); | |
139 | exthdr = (struct ipv6_opt_hdr *)(nh + offset); | |
140 | ||
141 | switch (nexthdr) { | |
142 | case NEXTHDR_FRAGMENT: | |
143 | onlyproto = 1; | |
144 | case NEXTHDR_ROUTING: | |
145 | case NEXTHDR_HOP: | |
146 | case NEXTHDR_DEST: | |
147 | offset += ipv6_optlen(exthdr); | |
148 | nexthdr = exthdr->nexthdr; | |
149 | exthdr = (struct ipv6_opt_hdr *)(nh + offset); | |
150 | break; | |
151 | ||
152 | case IPPROTO_UDP: | |
153 | case IPPROTO_UDPLITE: | |
154 | case IPPROTO_TCP: | |
155 | case IPPROTO_SCTP: | |
156 | case IPPROTO_DCCP: | |
157 | if (!onlyproto && (nh + offset + 4 < skb->data || | |
158 | pskb_may_pull(skb, nh + offset + 4 - skb->data))) { | |
159 | __be16 *ports = (__be16 *)exthdr; | |
160 | ||
161 | fl->fl_ip_sport = ports[!!reverse]; | |
162 | fl->fl_ip_dport = ports[!reverse]; | |
163 | } | |
164 | fl->proto = nexthdr; | |
165 | return; | |
166 | ||
167 | case IPPROTO_ICMPV6: | |
168 | if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { | |
169 | u8 *icmp = (u8 *)exthdr; | |
170 | ||
171 | fl->fl_icmp_type = icmp[0]; | |
172 | fl->fl_icmp_code = icmp[1]; | |
173 | } | |
174 | fl->proto = nexthdr; | |
175 | return; | |
176 | ||
177 | #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) | |
178 | case IPPROTO_MH: | |
179 | if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { | |
180 | struct ip6_mh *mh; | |
181 | mh = (struct ip6_mh *)exthdr; | |
182 | ||
183 | fl->fl_mh_type = mh->ip6mh_type; | |
184 | } | |
185 | fl->proto = nexthdr; | |
186 | return; | |
187 | #endif | |
188 | ||
189 | /* XXX Why are there these headers? */ | |
190 | case IPPROTO_AH: | |
191 | case IPPROTO_ESP: | |
192 | case IPPROTO_COMP: | |
193 | default: | |
194 | fl->fl_ipsec_spi = 0; | |
195 | fl->proto = nexthdr; | |
196 | return; | |
197 | } | |
198 | } | |
199 | } | |
200 | ||
201 | static inline int xfrm6_garbage_collect(struct dst_ops *ops) | |
202 | { | |
203 | struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); | |
204 | ||
205 | xfrm6_policy_afinfo.garbage_collect(net); | |
206 | return dst_entries_get_fast(ops) > ops->gc_thresh * 2; | |
207 | } | |
208 | ||
209 | static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) | |
210 | { | |
211 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
212 | struct dst_entry *path = xdst->route; | |
213 | ||
214 | path->ops->update_pmtu(path, mtu); | |
215 | } | |
216 | ||
217 | static void xfrm6_dst_destroy(struct dst_entry *dst) | |
218 | { | |
219 | struct xfrm_dst *xdst = (struct xfrm_dst *)dst; | |
220 | ||
221 | if (likely(xdst->u.rt6.rt6i_idev)) | |
222 | in6_dev_put(xdst->u.rt6.rt6i_idev); | |
223 | dst_destroy_metrics_generic(dst); | |
224 | if (likely(xdst->u.rt6.rt6i_peer)) | |
225 | inet_putpeer(xdst->u.rt6.rt6i_peer); | |
226 | xfrm_dst_destroy(xdst); | |
227 | } | |
228 | ||
229 | static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, | |
230 | int unregister) | |
231 | { | |
232 | struct xfrm_dst *xdst; | |
233 | ||
234 | if (!unregister) | |
235 | return; | |
236 | ||
237 | xdst = (struct xfrm_dst *)dst; | |
238 | if (xdst->u.rt6.rt6i_idev->dev == dev) { | |
239 | struct inet6_dev *loopback_idev = | |
240 | in6_dev_get(dev_net(dev)->loopback_dev); | |
241 | BUG_ON(!loopback_idev); | |
242 | ||
243 | do { | |
244 | in6_dev_put(xdst->u.rt6.rt6i_idev); | |
245 | xdst->u.rt6.rt6i_idev = loopback_idev; | |
246 | in6_dev_hold(loopback_idev); | |
247 | xdst = (struct xfrm_dst *)xdst->u.dst.child; | |
248 | } while (xdst->u.dst.xfrm); | |
249 | ||
250 | __in6_dev_put(loopback_idev); | |
251 | } | |
252 | ||
253 | xfrm_dst_ifdown(dst, dev); | |
254 | } | |
255 | ||
256 | static struct dst_ops xfrm6_dst_ops = { | |
257 | .family = AF_INET6, | |
258 | .protocol = cpu_to_be16(ETH_P_IPV6), | |
259 | .gc = xfrm6_garbage_collect, | |
260 | .update_pmtu = xfrm6_update_pmtu, | |
261 | .cow_metrics = dst_cow_metrics_generic, | |
262 | .destroy = xfrm6_dst_destroy, | |
263 | .ifdown = xfrm6_dst_ifdown, | |
264 | .local_out = __ip6_local_out, | |
265 | .gc_thresh = 1024, | |
266 | }; | |
267 | ||
268 | static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { | |
269 | .family = AF_INET6, | |
270 | .dst_ops = &xfrm6_dst_ops, | |
271 | .dst_lookup = xfrm6_dst_lookup, | |
272 | .get_saddr = xfrm6_get_saddr, | |
273 | .decode_session = _decode_session6, | |
274 | .get_tos = xfrm6_get_tos, | |
275 | .init_path = xfrm6_init_path, | |
276 | .fill_dst = xfrm6_fill_dst, | |
277 | }; | |
278 | ||
279 | static int __init xfrm6_policy_init(void) | |
280 | { | |
281 | return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); | |
282 | } | |
283 | ||
284 | static void xfrm6_policy_fini(void) | |
285 | { | |
286 | xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); | |
287 | } | |
288 | ||
289 | #ifdef CONFIG_SYSCTL | |
290 | static struct ctl_table xfrm6_policy_table[] = { | |
291 | { | |
292 | .procname = "xfrm6_gc_thresh", | |
293 | .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, | |
294 | .maxlen = sizeof(int), | |
295 | .mode = 0644, | |
296 | .proc_handler = proc_dointvec, | |
297 | }, | |
298 | { } | |
299 | }; | |
300 | ||
301 | static struct ctl_table_header *sysctl_hdr; | |
302 | #endif | |
303 | ||
304 | int __init xfrm6_init(void) | |
305 | { | |
306 | int ret; | |
307 | unsigned int gc_thresh; | |
308 | ||
309 | /* | |
310 | * We need a good default value for the xfrm6 gc threshold. | |
311 | * In ipv4 we set it to the route hash table size * 8, which | |
312 | * is half the size of the maximaum route cache for ipv4. It | |
313 | * would be good to do the same thing for v6, except the table is | |
314 | * constructed differently here. Here each table for a net namespace | |
315 | * can have FIB_TABLE_HASHSZ entries, so lets go with the same | |
316 | * computation that we used for ipv4 here. Also, lets keep the initial | |
317 | * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults | |
318 | * to that as a minimum as well | |
319 | */ | |
320 | gc_thresh = FIB6_TABLE_HASHSZ * 8; | |
321 | xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh; | |
322 | dst_entries_init(&xfrm6_dst_ops); | |
323 | ||
324 | ret = xfrm6_policy_init(); | |
325 | if (ret) { | |
326 | dst_entries_destroy(&xfrm6_dst_ops); | |
327 | goto out; | |
328 | } | |
329 | ret = xfrm6_state_init(); | |
330 | if (ret) | |
331 | goto out_policy; | |
332 | ||
333 | #ifdef CONFIG_SYSCTL | |
334 | sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path, | |
335 | xfrm6_policy_table); | |
336 | #endif | |
337 | out: | |
338 | return ret; | |
339 | out_policy: | |
340 | xfrm6_policy_fini(); | |
341 | goto out; | |
342 | } | |
343 | ||
344 | void xfrm6_fini(void) | |
345 | { | |
346 | #ifdef CONFIG_SYSCTL | |
347 | if (sysctl_hdr) | |
348 | unregister_net_sysctl_table(sysctl_hdr); | |
349 | #endif | |
350 | //xfrm6_input_fini(); | |
351 | xfrm6_policy_fini(); | |
352 | xfrm6_state_fini(); | |
353 | dst_entries_destroy(&xfrm6_dst_ops); | |
354 | } |