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(const struct xfrm_dst_lookup_params *params)
27{
28 struct flowi6 fl6;
29 struct dst_entry *dst;
30 int err;
31
32 memset(s: &fl6, c: 0, n: sizeof(fl6));
33 fl6.flowi6_l3mdev = l3mdev_master_ifindex_by_index(net: params->net,
34 ifindex: params->oif);
35 fl6.flowi6_mark = params->mark;
36 memcpy(to: &fl6.daddr, from: params->daddr, len: sizeof(fl6.daddr));
37 if (params->saddr)
38 memcpy(to: &fl6.saddr, from: params->saddr, len: sizeof(fl6.saddr));
39
40 fl6.flowi4_proto = params->ipproto;
41 fl6.uli = params->uli;
42
43 dst = ip6_route_output(net: params->net, NULL, fl6: &fl6);
44
45 err = dst->error;
46 if (dst->error) {
47 dst_release(dst);
48 dst = ERR_PTR(error: err);
49 }
50
51 return dst;
52}
53
54static int xfrm6_get_saddr(xfrm_address_t *saddr,
55 const struct xfrm_dst_lookup_params *params)
56{
57 struct dst_entry *dst;
58 struct net_device *dev;
59 struct inet6_dev *idev;
60
61 dst = xfrm6_dst_lookup(params);
62 if (IS_ERR(ptr: 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(net: dev_net(dev), dev, daddr: &params->daddr->in6, srcprefs: 0,
72 saddr: &saddr->in6);
73 dst_release(dst);
74 return 0;
75}
76
77static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
78 const struct flowi *fl)
79{
80 struct rt6_info *rt = dst_rt6_info(xdst->route);
81
82 xdst->u.dst.dev = dev;
83 netdev_hold(dev, tracker: &xdst->u.dst.dev_tracker, GFP_ATOMIC);
84
85 xdst->u.rt6.rt6i_idev = in6_dev_get(dev);
86 if (!xdst->u.rt6.rt6i_idev) {
87 netdev_put(dev, tracker: &xdst->u.dst.dev_tracker);
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 rt6_uncached_list_add(rt: &xdst->u.rt6);
100
101 return 0;
102}
103
104static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk,
105 struct sk_buff *skb, u32 mtu,
106 bool confirm_neigh)
107{
108 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
109 struct dst_entry *path = xdst->route;
110
111 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
112}
113
114static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk,
115 struct sk_buff *skb)
116{
117 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
118 struct dst_entry *path = xdst->route;
119
120 path->ops->redirect(path, sk, skb);
121}
122
123static void xfrm6_dst_destroy(struct dst_entry *dst)
124{
125 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
126
127 dst_destroy_metrics_generic(dst);
128 rt6_uncached_list_del(rt: &xdst->u.rt6);
129 if (likely(xdst->u.rt6.rt6i_idev))
130 in6_dev_put(idev: xdst->u.rt6.rt6i_idev);
131 xfrm_dst_destroy(xdst);
132}
133
134static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev)
135{
136 struct xfrm_dst *xdst;
137
138 xdst = (struct xfrm_dst *)dst;
139 if (xdst->u.rt6.rt6i_idev->dev == dev) {
140 struct inet6_dev *loopback_idev =
141 in6_dev_get(dev: dev_net(dev)->loopback_dev);
142
143 do {
144 in6_dev_put(idev: xdst->u.rt6.rt6i_idev);
145 xdst->u.rt6.rt6i_idev = loopback_idev;
146 in6_dev_hold(idev: loopback_idev);
147 xdst = (struct xfrm_dst *)xfrm_dst_child(dst: &xdst->u.dst);
148 } while (xdst->u.dst.xfrm);
149
150 __in6_dev_put(idev: loopback_idev);
151 }
152
153 xfrm_dst_ifdown(dst, dev);
154}
155
156static struct dst_ops xfrm6_dst_ops_template = {
157 .family = AF_INET6,
158 .update_pmtu = xfrm6_update_pmtu,
159 .redirect = xfrm6_redirect,
160 .cow_metrics = dst_cow_metrics_generic,
161 .destroy = xfrm6_dst_destroy,
162 .ifdown = xfrm6_dst_ifdown,
163 .local_out = __ip6_local_out,
164 .gc_thresh = 32768,
165};
166
167static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = {
168 .dst_ops = &xfrm6_dst_ops_template,
169 .dst_lookup = xfrm6_dst_lookup,
170 .get_saddr = xfrm6_get_saddr,
171 .fill_dst = xfrm6_fill_dst,
172 .blackhole_route = ip6_blackhole_route,
173};
174
175static int __init xfrm6_policy_init(void)
176{
177 return xfrm_policy_register_afinfo(afinfo: &xfrm6_policy_afinfo, AF_INET6);
178}
179
180static void xfrm6_policy_fini(void)
181{
182 xfrm_policy_unregister_afinfo(afinfo: &xfrm6_policy_afinfo);
183}
184
185#ifdef CONFIG_SYSCTL
186static struct ctl_table xfrm6_policy_table[] = {
187 {
188 .procname = "xfrm6_gc_thresh",
189 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh,
190 .maxlen = sizeof(int),
191 .mode = 0644,
192 .proc_handler = proc_dointvec,
193 },
194};
195
196static 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(net1: net, net2: &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, path: "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
218err_reg:
219 if (!net_eq(net1: net, net2: &init_net))
220 kfree(objp: table);
221err_alloc:
222 return -ENOMEM;
223}
224
225static void __net_exit xfrm6_net_sysctl_exit(struct net *net)
226{
227 const 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(header: net->ipv6.sysctl.xfrm6_hdr);
234 if (!net_eq(net1: net, net2: &init_net))
235 kfree(objp: table);
236}
237#else /* CONFIG_SYSCTL */
238static inline int xfrm6_net_sysctl_init(struct net *net)
239{
240 return 0;
241}
242
243static inline void xfrm6_net_sysctl_exit(struct net *net)
244{
245}
246#endif
247
248static int __net_init xfrm6_net_init(struct net *net)
249{
250 int ret;
251
252 memcpy(to: &net->xfrm.xfrm6_dst_ops, from: &xfrm6_dst_ops_template,
253 len: sizeof(xfrm6_dst_ops_template));
254 ret = dst_entries_init(dst: &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(dst: &net->xfrm.xfrm6_dst_ops);
261
262 return ret;
263}
264
265static void __net_exit xfrm6_net_exit(struct net *net)
266{
267 xfrm6_net_sysctl_exit(net);
268 dst_entries_destroy(dst: &net->xfrm.xfrm6_dst_ops);
269}
270
271static struct pernet_operations xfrm6_net_ops = {
272 .init = xfrm6_net_init,
273 .exit = xfrm6_net_exit,
274};
275
276int __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
295 ret = xfrm_nat_keepalive_init(AF_INET6);
296 if (ret)
297 goto out_nat_keepalive;
298out:
299 return ret;
300out_nat_keepalive:
301 unregister_pernet_subsys(&xfrm6_net_ops);
302out_protocol:
303 xfrm6_protocol_fini();
304out_state:
305 xfrm6_state_fini();
306out_policy:
307 xfrm6_policy_fini();
308 goto out;
309}
310
311void xfrm6_fini(void)
312{
313 xfrm_nat_keepalive_fini(AF_INET6);
314 unregister_pernet_subsys(&xfrm6_net_ops);
315 xfrm6_protocol_fini();
316 xfrm6_policy_fini();
317 xfrm6_state_fini();
318}
319