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_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
xfrm6_get_saddr(struct net * net,int oif,xfrm_address_t * saddr,xfrm_address_t * daddr,u32 mark)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
xfrm6_fill_dst(struct xfrm_dst * xdst,struct net_device * dev,const struct flowi * fl)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 = (struct 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
xfrm6_update_pmtu(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb,u32 mtu,bool confirm_neigh)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
xfrm6_redirect(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb)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
xfrm6_dst_destroy(struct dst_entry * dst)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
xfrm6_dst_ifdown(struct dst_entry * dst,struct net_device * dev)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
xfrm6_policy_init(void)174 static int __init xfrm6_policy_init(void)
175 {
176 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6);
177 }
178
xfrm6_policy_fini(void)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
xfrm6_net_sysctl_init(struct net * net)196 static int __net_init xfrm6_net_sysctl_init(struct net *net)
197 {
198 struct ctl_table *table;
199 struct ctl_table_header *hdr;
200
201 table = xfrm6_policy_table;
202 if (!net_eq(net, &init_net)) {
203 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL);
204 if (!table)
205 goto err_alloc;
206
207 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
208 }
209
210 hdr = register_net_sysctl_sz(net, "net/ipv6", table,
211 ARRAY_SIZE(xfrm6_policy_table));
212 if (!hdr)
213 goto err_reg;
214
215 net->ipv6.sysctl.xfrm6_hdr = hdr;
216 return 0;
217
218 err_reg:
219 if (!net_eq(net, &init_net))
220 kfree(table);
221 err_alloc:
222 return -ENOMEM;
223 }
224
xfrm6_net_sysctl_exit(struct net * net)225 static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
226 {
227 struct ctl_table *table;
228
229 if (!net->ipv6.sysctl.xfrm6_hdr)
230 return;
231
232 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
233 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr);
234 if (!net_eq(net, &init_net))
235 kfree(table);
236 }
237 #else /* CONFIG_SYSCTL */
xfrm6_net_sysctl_init(struct net * net)238 static inline int xfrm6_net_sysctl_init(struct net *net)
239 {
240 return 0;
241 }
242
xfrm6_net_sysctl_exit(struct net * net)243 static inline void xfrm6_net_sysctl_exit(struct net *net)
244 {
245 }
246 #endif
247
xfrm6_net_init(struct net * net)248 static int __net_init xfrm6_net_init(struct net *net)
249 {
250 int ret;
251
252 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
253 sizeof(xfrm6_dst_ops_template));
254 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops);
255 if (ret)
256 return ret;
257
258 ret = xfrm6_net_sysctl_init(net);
259 if (ret)
260 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
261
262 return ret;
263 }
264
xfrm6_net_exit(struct net * net)265 static void __net_exit xfrm6_net_exit(struct net *net)
266 {
267 xfrm6_net_sysctl_exit(net);
268 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops);
269 }
270
271 static struct pernet_operations xfrm6_net_ops = {
272 .init = xfrm6_net_init,
273 .exit = xfrm6_net_exit,
274 };
275
xfrm6_init(void)276 int __init xfrm6_init(void)
277 {
278 int ret;
279
280 ret = xfrm6_policy_init();
281 if (ret)
282 goto out;
283 ret = xfrm6_state_init();
284 if (ret)
285 goto out_policy;
286
287 ret = xfrm6_protocol_init();
288 if (ret)
289 goto out_state;
290
291 ret = register_pernet_subsys(&xfrm6_net_ops);
292 if (ret)
293 goto out_protocol;
294 out:
295 return ret;
296 out_protocol:
297 xfrm6_protocol_fini();
298 out_state:
299 xfrm6_state_fini();
300 out_policy:
301 xfrm6_policy_fini();
302 goto out;
303 }
304
xfrm6_fini(void)305 void xfrm6_fini(void)
306 {
307 unregister_pernet_subsys(&xfrm6_net_ops);
308 xfrm6_protocol_fini();
309 xfrm6_policy_fini();
310 xfrm6_state_fini();
311 }
312