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
61 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark);
62 if (IS_ERR(dst))
63 return -EHOSTUNREACH;
64
65 dev = ip6_dst_idev(dst)->dev;
66 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6);
67 dst_release(dst);
68 return 0;
69 }
70
xfrm6_fill_dst(struct xfrm_dst * xdst,struct net_device * dev,const struct flowi * fl)71 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
72 const struct flowi *fl)
73 {
74 struct rt6_info *rt = (struct rt6_info *)xdst->route;
75
76 xdst->u.dst.dev = dev;
77 dev_hold(dev);
78
79 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
80 if (!xdst->u.rt6.rt6i_idev) {
81 dev_put(dev);
82 return -ENODEV;
83 }
84
85 /* Sheit... I remember I did this right. Apparently,
86 * it was magically lost, so this code needs audit */
87 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
88 RTF_LOCAL);
89 xdst->route_cookie = rt6_get_cookie(rt);
90 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
91 xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
92 xdst->u.rt6.rt6i_src = rt->rt6i_src;
93 INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached);
94 rt6_uncached_list_add(&xdst->u.rt6);
95 atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache);
96
97 return 0;
98 }
99
xfrm6_update_pmtu(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb,u32 mtu,bool confirm_neigh)100 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
101 struct sk_buff *skb, u32 mtu,
102 bool confirm_neigh)
103 {
104 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
105 struct dst_entry *path = xdst->route;
106
107 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
108 }
109
xfrm6_redirect(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb)110 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
111 struct sk_buff *skb)
112 {
113 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
114 struct dst_entry *path = xdst->route;
115
116 path->ops->redirect(path, sk, skb);
117 }
118
xfrm6_dst_destroy(struct dst_entry * dst)119 static void xfrm6_dst_destroy(struct dst_entry *dst)
120 {
121 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
122
123 if (likely(xdst->u.rt6.rt6i_idev))
124 in6_dev_put(xdst->u.rt6.rt6i_idev);
125 dst_destroy_metrics_generic(dst);
126 if (xdst->u.rt6.rt6i_uncached_list)
127 rt6_uncached_list_del(&xdst->u.rt6);
128 xfrm_dst_destroy(xdst);
129 }
130
xfrm6_dst_ifdown(struct dst_entry * dst,struct net_device * dev,int unregister)131 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
132 int unregister)
133 {
134 struct xfrm_dst *xdst;
135
136 if (!unregister)
137 return;
138
139 xdst = (struct xfrm_dst *)dst;
140 if (xdst->u.rt6.rt6i_idev->dev == dev) {
141 struct inet6_dev *loopback_idev =
142 in6_dev_get(dev_net(dev)->loopback_dev);
143
144 do {
145 in6_dev_put(xdst->u.rt6.rt6i_idev);
146 xdst->u.rt6.rt6i_idev = loopback_idev;
147 in6_dev_hold(loopback_idev);
148 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst);
149 } while (xdst->u.dst.xfrm);
150
151 __in6_dev_put(loopback_idev);
152 }
153
154 xfrm_dst_ifdown(dst, dev);
155 }
156
157 static struct dst_ops xfrm6_dst_ops_template = {
158 .family = AF_INET6,
159 .update_pmtu = xfrm6_update_pmtu,
160 .redirect = xfrm6_redirect,
161 .cow_metrics = dst_cow_metrics_generic,
162 .destroy = xfrm6_dst_destroy,
163 .ifdown = xfrm6_dst_ifdown,
164 .local_out = __ip6_local_out,
165 .gc_thresh = 32768,
166 };
167
168 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
169 .dst_ops = &xfrm6_dst_ops_template,
170 .dst_lookup = xfrm6_dst_lookup,
171 .get_saddr = xfrm6_get_saddr,
172 .fill_dst = xfrm6_fill_dst,
173 .blackhole_route = ip6_blackhole_route,
174 };
175
xfrm6_policy_init(void)176 static int __init xfrm6_policy_init(void)
177 {
178 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6);
179 }
180
xfrm6_policy_fini(void)181 static void xfrm6_policy_fini(void)
182 {
183 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
184 }
185
186 #ifdef CONFIG_SYSCTL
187 static struct ctl_table xfrm6_policy_table[] = {
188 {
189 .procname = "xfrm6_gc_thresh",
190 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
191 .maxlen = sizeof(int),
192 .mode = 0644,
193 .proc_handler = proc_dointvec,
194 },
195 { }
196 };
197
xfrm6_net_sysctl_init(struct net * net)198 static int __net_init xfrm6_net_sysctl_init(struct net *net)
199 {
200 struct ctl_table *table;
201 struct ctl_table_header *hdr;
202
203 table = xfrm6_policy_table;
204 if (!net_eq(net, &init_net)) {
205 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
206 if (!table)
207 goto err_alloc;
208
209 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
210 }
211
212 hdr = register_net_sysctl(net, "net/ipv6", table);
213 if (!hdr)
214 goto err_reg;
215
216 net->ipv6.sysctl.xfrm6_hdr = hdr;
217 return 0;
218
219 err_reg:
220 if (!net_eq(net, &init_net))
221 kfree(table);
222 err_alloc:
223 return -ENOMEM;
224 }
225
xfrm6_net_sysctl_exit(struct net * net)226 static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
227 {
228 struct ctl_table *table;
229
230 if (!net->ipv6.sysctl.xfrm6_hdr)
231 return;
232
233 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
234 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
235 if (!net_eq(net, &init_net))
236 kfree(table);
237 }
238 #else /* CONFIG_SYSCTL */
xfrm6_net_sysctl_init(struct net * net)239 static inline int xfrm6_net_sysctl_init(struct net *net)
240 {
241 return 0;
242 }
243
xfrm6_net_sysctl_exit(struct net * net)244 static inline void xfrm6_net_sysctl_exit(struct net *net)
245 {
246 }
247 #endif
248
xfrm6_net_init(struct net * net)249 static int __net_init xfrm6_net_init(struct net *net)
250 {
251 int ret;
252
253 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
254 sizeof(xfrm6_dst_ops_template));
255 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops);
256 if (ret)
257 return ret;
258
259 ret = xfrm6_net_sysctl_init(net);
260 if (ret)
261 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
262
263 return ret;
264 }
265
xfrm6_net_exit(struct net * net)266 static void __net_exit xfrm6_net_exit(struct net *net)
267 {
268 xfrm6_net_sysctl_exit(net);
269 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
270 }
271
272 static struct pernet_operations xfrm6_net_ops = {
273 .init = xfrm6_net_init,
274 .exit = xfrm6_net_exit,
275 };
276
xfrm6_init(void)277 int __init xfrm6_init(void)
278 {
279 int ret;
280
281 ret = xfrm6_policy_init();
282 if (ret)
283 goto out;
284 ret = xfrm6_state_init();
285 if (ret)
286 goto out_policy;
287
288 ret = xfrm6_protocol_init();
289 if (ret)
290 goto out_state;
291
292 register_pernet_subsys(&xfrm6_net_ops);
293 out:
294 return ret;
295 out_state:
296 xfrm6_state_fini();
297 out_policy:
298 xfrm6_policy_fini();
299 goto out;
300 }
301
xfrm6_fini(void)302 void xfrm6_fini(void)
303 {
304 unregister_pernet_subsys(&xfrm6_net_ops);
305 xfrm6_protocol_fini();
306 xfrm6_policy_fini();
307 xfrm6_state_fini();
308 }
309