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
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_l3mdev = l3mdev_master_ifindex_by_index(net, oif);
37 fl6.flowi6_mark = mark;
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
53 static int xfrm6_get_saddr(struct net *net, int oif,
54 xfrm_address_t *saddr, xfrm_address_t *daddr,
55 u32 mark)
56 {
57 struct dst_entry *dst;
58 struct net_device *dev;
59 struct inet6_dev *idev;
60
61 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark);
62 if (IS_ERR(dst))
63 return -EHOSTUNREACH;
64
65 idev = ip6_dst_idev(dst);
66 if (!idev) {
67 dst_release(dst);
68 return -EHOSTUNREACH;
69 }
70 dev = idev->dev;
71 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
72 dst_release(dst);
73 return 0;
74 }
75
76 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
77 const struct flowi *fl)
78 {
79 struct rt6_info *rt = dst_rt6_info(xdst->route);
80
81 xdst->u.dst.dev = dev;
82 netdev_hold(dev, &xdst->u.dst.dev_tracker, GFP_ATOMIC);
83
84 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
85 if (!xdst->u.rt6.rt6i_idev) {
86 netdev_put(dev, &xdst->u.dst.dev_tracker);
87 return -ENODEV;
88 }
89
90 /* Sheit... I remember I did this right. Apparently,
91 * it was magically lost, so this code needs audit */
92 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
93 RTF_LOCAL);
94 xdst->route_cookie = rt6_get_cookie(rt);
95 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
96 xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
97 xdst->u.rt6.rt6i_src = rt->rt6i_src;
98 rt6_uncached_list_add(&xdst->u.rt6);
99
100 return 0;
101 }
102
103 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
104 struct sk_buff *skb, u32 mtu,
105 bool confirm_neigh)
106 {
107 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
108 struct dst_entry *path = xdst->route;
109
110 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
111 }
112
113 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
114 struct sk_buff *skb)
115 {
116 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
117 struct dst_entry *path = xdst->route;
118
119 path->ops->redirect(path, sk, skb);
120 }
121
122 static void xfrm6_dst_destroy(struct dst_entry *dst)
123 {
124 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
125
126 dst_destroy_metrics_generic(dst);
127 rt6_uncached_list_del(&xdst->u.rt6);
128 if (likely(xdst->u.rt6.rt6i_idev))
129 in6_dev_put(xdst->u.rt6.rt6i_idev);
130 xfrm_dst_destroy(xdst);
131 }
132
133 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
134 {
135 struct xfrm_dst *xdst;
136
137 xdst = (struct xfrm_dst *)dst;
138 if (xdst->u.rt6.rt6i_idev->dev == dev) {
139 struct inet6_dev *loopback_idev =
140 in6_dev_get(dev_net(dev)->loopback_dev);
141
142 do {
143 in6_dev_put(xdst->u.rt6.rt6i_idev);
144 xdst->u.rt6.rt6i_idev = loopback_idev;
145 in6_dev_hold(loopback_idev);
146 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst);
147 } while (xdst->u.dst.xfrm);
148
149 __in6_dev_put(loopback_idev);
150 }
151
152 xfrm_dst_ifdown(dst, dev);
153 }
154
155 static struct dst_ops xfrm6_dst_ops_template = {
156 .family = AF_INET6,
157 .update_pmtu = xfrm6_update_pmtu,
158 .redirect = xfrm6_redirect,
159 .cow_metrics = dst_cow_metrics_generic,
160 .destroy = xfrm6_dst_destroy,
161 .ifdown = xfrm6_dst_ifdown,
162 .local_out = __ip6_local_out,
163 .gc_thresh = 32768,
164 };
165
166 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
167 .dst_ops = &xfrm6_dst_ops_template,
168 .dst_lookup = xfrm6_dst_lookup,
169 .get_saddr = xfrm6_get_saddr,
170 .fill_dst = xfrm6_fill_dst,
171 .blackhole_route = ip6_blackhole_route,
172 };
173
174 static int __init xfrm6_policy_init(void)
175 {
176 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6);
177 }
178
179 static void xfrm6_policy_fini(void)
180 {
181 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
182 }
183
184 #ifdef CONFIG_SYSCTL
185 static struct ctl_table xfrm6_policy_table[] = {
186 {
187 .procname = "xfrm6_gc_thresh",
188 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
189 .maxlen = sizeof(int),
190 .mode = 0644,
191 .proc_handler = proc_dointvec,
192 },
193 };
194
195 static int __net_init xfrm6_net_sysctl_init(struct net *net)
196 {
197 struct ctl_table *table;
198 struct ctl_table_header *hdr;
199
200 table = xfrm6_policy_table;
201 if (!net_eq(net, &init_net)) {
202 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
203 if (!table)
204 goto err_alloc;
205
206 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
207 }
208
209 hdr = register_net_sysctl_sz(net, "net/ipv6", table,
210 ARRAY_SIZE(xfrm6_policy_table));
211 if (!hdr)
212 goto err_reg;
213
214 net->ipv6.sysctl.xfrm6_hdr = hdr;
215 return 0;
216
217 err_reg:
218 if (!net_eq(net, &init_net))
219 kfree(table);
220 err_alloc:
221 return -ENOMEM;
222 }
223
224 static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
225 {
226 const struct ctl_table *table;
227
228 if (!net->ipv6.sysctl.xfrm6_hdr)
229 return;
230
231 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
232 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
233 if (!net_eq(net, &init_net))
234 kfree(table);
235 }
236 #else /* CONFIG_SYSCTL */
237 static inline int xfrm6_net_sysctl_init(struct net *net)
238 {
239 return 0;
240 }
241
242 static inline void xfrm6_net_sysctl_exit(struct net *net)
243 {
244 }
245 #endif
246
247 static int __net_init xfrm6_net_init(struct net *net)
248 {
249 int ret;
250
251 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
252 sizeof(xfrm6_dst_ops_template));
253 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops);
254 if (ret)
255 return ret;
256
257 ret = xfrm6_net_sysctl_init(net);
258 if (ret)
259 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
260
261 return ret;
262 }
263
264 static void __net_exit xfrm6_net_exit(struct net *net)
265 {
266 xfrm6_net_sysctl_exit(net);
267 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
268 }
269
270 static struct pernet_operations xfrm6_net_ops = {
271 .init = xfrm6_net_init,
272 .exit = xfrm6_net_exit,
273 };
274
275 int __init xfrm6_init(void)
276 {
277 int ret;
278
279 ret = xfrm6_policy_init();
280 if (ret)
281 goto out;
282 ret = xfrm6_state_init();
283 if (ret)
284 goto out_policy;
285
286 ret = xfrm6_protocol_init();
287 if (ret)
288 goto out_state;
289
290 ret = register_pernet_subsys(&xfrm6_net_ops);
291 if (ret)
292 goto out_protocol;
293
294 ret = xfrm_nat_keepalive_init(AF_INET6);
295 if (ret)
296 goto out_nat_keepalive;
297 out:
298 return ret;
299 out_nat_keepalive:
300 unregister_pernet_subsys(&xfrm6_net_ops);
301 out_protocol:
302 xfrm6_protocol_fini();
303 out_state:
304 xfrm6_state_fini();
305 out_policy:
306 xfrm6_policy_fini();
307 goto out;
308 }
309
310 void xfrm6_fini(void)
311 {
312 xfrm_nat_keepalive_fini(AF_INET6);
313 unregister_pernet_subsys(&xfrm6_net_ops);
314 xfrm6_protocol_fini();
315 xfrm6_policy_fini();
316 xfrm6_state_fini();
317 }
318
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