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
26static 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, ifindex: 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: &fl6);
43
44 err = dst->error;
45 if (dst->error) {
46 dst_release(dst);
47 dst = ERR_PTR(error: err);
48 }
49
50 return dst;
51}
52
53static 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
60 dst = xfrm6_dst_lookup(net, tos: 0, oif, NULL, daddr, mark);
61 if (IS_ERR(ptr: dst))
62 return -EHOSTUNREACH;
63
64 dev = ip6_dst_idev(dst)->dev;
65 ipv6_dev_get_saddr(net: dev_net(dev), dev, daddr: &daddr->in6, srcprefs: 0, saddr: &saddr->in6);
66 dst_release(dst);
67 return 0;
68}
69
70static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
71 const struct flowi *fl)
72{
73 struct rt6_info *rt = (struct rt6_info *)xdst->route;
74
75 xdst->u.dst.dev = dev;
76 netdev_hold(dev, tracker: &xdst->u.dst.dev_tracker, GFP_ATOMIC);
77
78 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
79 if (!xdst->u.rt6.rt6i_idev) {
80 netdev_put(dev, tracker: &xdst->u.dst.dev_tracker);
81 return -ENODEV;
82 }
83
84 /* Sheit... I remember I did this right. Apparently,
85 * it was magically lost, so this code needs audit */
86 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST |
87 RTF_LOCAL);
88 xdst->route_cookie = rt6_get_cookie(rt);
89 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway;
90 xdst->u.rt6.rt6i_dst = rt->rt6i_dst;
91 xdst->u.rt6.rt6i_src = rt->rt6i_src;
92 rt6_uncached_list_add(rt: &xdst->u.rt6);
93
94 return 0;
95}
96
97static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
98 struct sk_buff *skb, u32 mtu,
99 bool confirm_neigh)
100{
101 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
102 struct dst_entry *path = xdst->route;
103
104 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
105}
106
107static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
108 struct sk_buff *skb)
109{
110 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
111 struct dst_entry *path = xdst->route;
112
113 path->ops->redirect(path, sk, skb);
114}
115
116static void xfrm6_dst_destroy(struct dst_entry *dst)
117{
118 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
119
120 dst_destroy_metrics_generic(dst);
121 rt6_uncached_list_del(rt: &xdst->u.rt6);
122 if (likely(xdst->u.rt6.rt6i_idev))
123 in6_dev_put(idev: xdst->u.rt6.rt6i_idev);
124 xfrm_dst_destroy(xdst);
125}
126
127static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
128{
129 struct xfrm_dst *xdst;
130
131 xdst = (struct xfrm_dst *)dst;
132 if (xdst->u.rt6.rt6i_idev->dev == dev) {
133 struct inet6_dev *loopback_idev =
134 in6_dev_get(dev: dev_net(dev)->loopback_dev);
135
136 do {
137 in6_dev_put(idev: xdst->u.rt6.rt6i_idev);
138 xdst->u.rt6.rt6i_idev = loopback_idev;
139 in6_dev_hold(idev: loopback_idev);
140 xdst = (struct xfrm_dst *)xfrm_dst_child(dst: &xdst->u.dst);
141 } while (xdst->u.dst.xfrm);
142
143 __in6_dev_put(idev: loopback_idev);
144 }
145
146 xfrm_dst_ifdown(dst, dev);
147}
148
149static struct dst_ops xfrm6_dst_ops_template = {
150 .family = AF_INET6,
151 .update_pmtu = xfrm6_update_pmtu,
152 .redirect = xfrm6_redirect,
153 .cow_metrics = dst_cow_metrics_generic,
154 .destroy = xfrm6_dst_destroy,
155 .ifdown = xfrm6_dst_ifdown,
156 .local_out = __ip6_local_out,
157 .gc_thresh = 32768,
158};
159
160static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
161 .dst_ops = &xfrm6_dst_ops_template,
162 .dst_lookup = xfrm6_dst_lookup,
163 .get_saddr = xfrm6_get_saddr,
164 .fill_dst = xfrm6_fill_dst,
165 .blackhole_route = ip6_blackhole_route,
166};
167
168static int __init xfrm6_policy_init(void)
169{
170 return xfrm_policy_register_afinfo(afinfo: &xfrm6_policy_afinfo, AF_INET6);
171}
172
173static void xfrm6_policy_fini(void)
174{
175 xfrm_policy_unregister_afinfo(afinfo: &xfrm6_policy_afinfo);
176}
177
178#ifdef CONFIG_SYSCTL
179static struct ctl_table xfrm6_policy_table[] = {
180 {
181 .procname = "xfrm6_gc_thresh",
182 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
183 .maxlen = sizeof(int),
184 .mode = 0644,
185 .proc_handler = proc_dointvec,
186 },
187 { }
188};
189
190static int __net_init xfrm6_net_sysctl_init(struct net *net)
191{
192 struct ctl_table *table;
193 struct ctl_table_header *hdr;
194
195 table = xfrm6_policy_table;
196 if (!net_eq(net1: net, net2: &init_net)) {
197 table = kmemdup(p: table, size: sizeof(xfrm6_policy_table), GFP_KERNEL);
198 if (!table)
199 goto err_alloc;
200
201 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh;
202 }
203
204 hdr = register_net_sysctl_sz(net, path: "net/ipv6", table,
205 ARRAY_SIZE(xfrm6_policy_table));
206 if (!hdr)
207 goto err_reg;
208
209 net->ipv6.sysctl.xfrm6_hdr = hdr;
210 return 0;
211
212err_reg:
213 if (!net_eq(net1: net, net2: &init_net))
214 kfree(objp: table);
215err_alloc:
216 return -ENOMEM;
217}
218
219static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
220{
221 struct ctl_table *table;
222
223 if (!net->ipv6.sysctl.xfrm6_hdr)
224 return;
225
226 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg;
227 unregister_net_sysctl_table(header: net->ipv6.sysctl.xfrm6_hdr);
228 if (!net_eq(net1: net, net2: &init_net))
229 kfree(objp: table);
230}
231#else /* CONFIG_SYSCTL */
232static inline int xfrm6_net_sysctl_init(struct net *net)
233{
234 return 0;
235}
236
237static inline void xfrm6_net_sysctl_exit(struct net *net)
238{
239}
240#endif
241
242static int __net_init xfrm6_net_init(struct net *net)
243{
244 int ret;
245
246 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template,
247 sizeof(xfrm6_dst_ops_template));
248 ret = dst_entries_init(dst: &net->xfrm.xfrm6_dst_ops);
249 if (ret)
250 return ret;
251
252 ret = xfrm6_net_sysctl_init(net);
253 if (ret)
254 dst_entries_destroy(dst: &net->xfrm.xfrm6_dst_ops);
255
256 return ret;
257}
258
259static void __net_exit xfrm6_net_exit(struct net *net)
260{
261 xfrm6_net_sysctl_exit(net);
262 dst_entries_destroy(dst: &net->xfrm.xfrm6_dst_ops);
263}
264
265static struct pernet_operations xfrm6_net_ops = {
266 .init = xfrm6_net_init,
267 .exit = xfrm6_net_exit,
268};
269
270int __init xfrm6_init(void)
271{
272 int ret;
273
274 ret = xfrm6_policy_init();
275 if (ret)
276 goto out;
277 ret = xfrm6_state_init();
278 if (ret)
279 goto out_policy;
280
281 ret = xfrm6_protocol_init();
282 if (ret)
283 goto out_state;
284
285 ret = register_pernet_subsys(&xfrm6_net_ops);
286 if (ret)
287 goto out_protocol;
288out:
289 return ret;
290out_protocol:
291 xfrm6_protocol_fini();
292out_state:
293 xfrm6_state_fini();
294out_policy:
295 xfrm6_policy_fini();
296 goto out;
297}
298
299void xfrm6_fini(void)
300{
301 unregister_pernet_subsys(&xfrm6_net_ops);
302 xfrm6_protocol_fini();
303 xfrm6_policy_fini();
304 xfrm6_state_fini();
305}
306

source code of linux/net/ipv6/xfrm6_policy.c