1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * xfrm6_policy.c: based on xfrm4_policy.c
4 *
5 * Authors:
6 * Mitsuru KANDA @USAGI
7 * Kazunori MIYAZAWA @USAGI
8 * Kunihiro Ishiguro <kunihiro@ipinfusion.com>
9 * IPv6 support
10 * YOSHIFUJI Hideaki
11 * Split up af-specific portion
12 *
13 */
14
15 #include <linux/err.h>
16 #include <linux/kernel.h>
17 #include <linux/netdevice.h>
18 #include <net/addrconf.h>
19 #include <net/dst.h>
20 #include <net/xfrm.h>
21 #include <net/ip.h>
22 #include <net/ipv6.h>
23 #include <net/ip6_route.h>
24 #include <net/l3mdev.h>
25
xfrm6_dst_lookup(struct net *net, int tos, int oif, const xfrm_address_t *saddr, const xfrm_address_t *daddr, u32 mark)26 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif,
27 const xfrm_address_t *saddr,
28 const xfrm_address_t *daddr,
29 u32 mark)
30 {
31 struct flowi6 fl6;
32 struct dst_entry *dst;
33 int err;
34
35 memset(&fl6, 0, sizeof(fl6));
36 fl6.flowi6_oif = l3mdev_master_ifindex_by_index(net, oif);
37 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF;
38 fl6.flowi6_mark = mark;
39 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr));
40 if (saddr)
41 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr));
42
43 dst = ip6_route_output(net, NULL, &fl6);
44
45 err = dst->error;
46 if (dst->error) {
47 dst_release(dst);
48 dst = ERR_PTR(err);
49 }
50
51 return dst;
52 }
53
xfrm6_get_saddr(struct net *net, int oif, xfrm_address_t *saddr, xfrm_address_t *daddr, u32 mark)54 static int xfrm6_get_saddr(struct net *net, int oif,
55 xfrm_address_t *saddr, xfrm_address_t *daddr,
56 u32 mark)
57 {
58 struct dst_entry *dst;
59 struct net_device *dev;
60 struct inet6_dev *idev;
61
62 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark);
63 if (IS_ERR(dst))
64 return -EHOSTUNREACH;
65
66 idev = ip6_dst_idev(dst);
67 if (!idev) {
68 dst_release(dst);
69 return -EHOSTUNREACH;
70 }
71 dev = idev->dev;
72 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
73 dst_release(dst);
74 return 0;
75 }
76
xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, const struct flowi *fl)77 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
78 const struct flowi *fl)
79 {
80 struct rt6_info *rt = (struct rt6_info *)xdst->route;
81
82 xdst->u.dst.dev = dev;
83 dev_hold(dev);
84
85 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
86 if (!xdst->u.rt6.rt6i_idev) {
87 dev_put(dev);
88 return -ENODEV;
89 }
90
91 /* Sheit... I remember I did this right. Apparently,
92 * it was magically lost, so this code needs audit */
93 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
94 RTF_LOCAL);
95 xdst->route_cookie = rt6_get_cookie(rt);
96 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
97 xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
98 xdst->u.rt6.rt6i_src = rt->rt6i_src;
99 INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached);
100 rt6_uncached_list_add(&xdst->u.rt6);
101 atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache);
102
103 return 0;
104 }
105
xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb, u32 mtu, bool confirm_neigh)106 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
107 struct sk_buff *skb, u32 mtu,
108 bool confirm_neigh)
109 {
110 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
111 struct dst_entry *path = xdst->route;
112
113 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
114 }
115
xfrm6_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)116 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
117 struct sk_buff *skb)
118 {
119 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
120 struct dst_entry *path = xdst->route;
121
122 path->ops->redirect(path, sk, skb);
123 }
124
xfrm6_dst_destroy(struct dst_entry *dst)125 static void xfrm6_dst_destroy(struct dst_entry *dst)
126 {
127 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
128
129 dst_destroy_metrics_generic(dst);
130 if (xdst->u.rt6.rt6i_uncached_list)
131 rt6_uncached_list_del(&xdst->u.rt6);
132 if (likely(xdst->u.rt6.rt6i_idev))
133 in6_dev_put(xdst->u.rt6.rt6i_idev);
134 xfrm_dst_destroy(xdst);
135 }
136
xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int unregister)137 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
138 int unregister)
139 {
140 struct xfrm_dst *xdst;
141
142 if (!unregister)
143 return;
144
145 xdst = (struct xfrm_dst *)dst;
146 if (xdst->u.rt6.rt6i_idev->dev == dev) {
147 struct inet6_dev *loopback_idev =
148 in6_dev_get(dev_net(dev)->loopback_dev);
149
150 do {
151 in6_dev_put(xdst->u.rt6.rt6i_idev);
152 xdst->u.rt6.rt6i_idev = loopback_idev;
153 in6_dev_hold(loopback_idev);
154 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst);
155 } while (xdst->u.dst.xfrm);
156
157 __in6_dev_put(loopback_idev);
158 }
159
160 xfrm_dst_ifdown(dst, dev);
161 }
162
163 static struct dst_ops xfrm6_dst_ops_template = {
164 .family = AF_INET6,
165 .update_pmtu = xfrm6_update_pmtu,
166 .redirect = xfrm6_redirect,
167 .cow_metrics = dst_cow_metrics_generic,
168 .destroy = xfrm6_dst_destroy,
169 .ifdown = xfrm6_dst_ifdown,
170 .local_out = __ip6_local_out,
171 .gc_thresh = 32768,
172 };
173
174 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
175 .dst_ops = &xfrm6_dst_ops_template,
176 .dst_lookup = xfrm6_dst_lookup,
177 .get_saddr = xfrm6_get_saddr,
178 .fill_dst = xfrm6_fill_dst,
179 .blackhole_route = ip6_blackhole_route,
180 };
181
xfrm6_policy_init(void)182 static int __init xfrm6_policy_init(void)
183 {
184 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6);
185 }
186
xfrm6_policy_fini(void)187 static void xfrm6_policy_fini(void)
188 {
189 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
190 }
191
192 #ifdef CONFIG_SYSCTL
193 static struct ctl_table xfrm6_policy_table[] = {
194 {
195 .procname = "xfrm6_gc_thresh",
196 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
197 .maxlen = sizeof(int),
198 .mode = 0644,
199 .proc_handler = proc_dointvec,
200 },
201 { }
202 };
203
xfrm6_net_sysctl_init(struct net *net)204 static int __net_init xfrm6_net_sysctl_init(struct net *net)
205 {
206 struct ctl_table *table;
207 struct ctl_table_header *hdr;
208
209 table = xfrm6_policy_table;
210 if (!net_eq(net, &init_net)) {
211 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
212 if (!table)
213 goto err_alloc;
214
215 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
216 }
217
218 hdr = register_net_sysctl(net, "net/ipv6", table);
219 if (!hdr)
220 goto err_reg;
221
222 net->ipv6.sysctl.xfrm6_hdr = hdr;
223 return 0;
224
225 err_reg:
226 if (!net_eq(net, &init_net))
227 kfree(table);
228 err_alloc:
229 return -ENOMEM;
230 }
231
xfrm6_net_sysctl_exit(struct net *net)232 static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
233 {
234 struct ctl_table *table;
235
236 if (!net->ipv6.sysctl.xfrm6_hdr)
237 return;
238
239 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
240 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
241 if (!net_eq(net, &init_net))
242 kfree(table);
243 }
244 #else /* CONFIG_SYSCTL */
xfrm6_net_sysctl_init(struct net *net)245 static inline int xfrm6_net_sysctl_init(struct net *net)
246 {
247 return 0;
248 }
249
xfrm6_net_sysctl_exit(struct net *net)250 static inline void xfrm6_net_sysctl_exit(struct net *net)
251 {
252 }
253 #endif
254
xfrm6_net_init(struct net *net)255 static int __net_init xfrm6_net_init(struct net *net)
256 {
257 int ret;
258
259 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
260 sizeof(xfrm6_dst_ops_template));
261 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops);
262 if (ret)
263 return ret;
264
265 ret = xfrm6_net_sysctl_init(net);
266 if (ret)
267 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
268
269 return ret;
270 }
271
xfrm6_net_exit(struct net *net)272 static void __net_exit xfrm6_net_exit(struct net *net)
273 {
274 xfrm6_net_sysctl_exit(net);
275 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
276 }
277
278 static struct pernet_operations xfrm6_net_ops = {
279 .init = xfrm6_net_init,
280 .exit = xfrm6_net_exit,
281 };
282
xfrm6_init(void)283 int __init xfrm6_init(void)
284 {
285 int ret;
286
287 ret = xfrm6_policy_init();
288 if (ret)
289 goto out;
290 ret = xfrm6_state_init();
291 if (ret)
292 goto out_policy;
293
294 ret = xfrm6_protocol_init();
295 if (ret)
296 goto out_state;
297
298 ret = register_pernet_subsys(&xfrm6_net_ops);
299 if (ret)
300 goto out_protocol;
301 out:
302 return ret;
303 out_protocol:
304 xfrm6_protocol_fini();
305 out_state:
306 xfrm6_state_fini();
307 out_policy:
308 xfrm6_policy_fini();
309 goto out;
310 }
311
xfrm6_fini(void)312 void xfrm6_fini(void)
313 {
314 unregister_pernet_subsys(&xfrm6_net_ops);
315 xfrm6_protocol_fini();
316 xfrm6_policy_fini();
317 xfrm6_state_fini();
318 }
319