1// SPDX-License-Identifier: GPL-2.0
2/*
3 * xfrm4_policy.c
4 *
5 * Changes:
6 * Kazunori MIYAZAWA @USAGI
7 * YOSHIFUJI Hideaki @USAGI
8 * Split up af-specific portion
9 *
10 */
11
12#include <linux/err.h>
13#include <linux/kernel.h>
14#include <linux/inetdevice.h>
15#include <net/dst.h>
16#include <net/xfrm.h>
17#include <net/flow.h>
18#include <net/ip.h>
19#include <net/l3mdev.h>
20
21static struct dst_entry *__xfrm4_dst_lookup(struct flowi4 *fl4,
22 const struct xfrm_dst_lookup_params *params)
23{
24 struct rtable *rt;
25
26 memset(s: fl4, c: 0, n: sizeof(*fl4));
27 fl4->daddr = params->daddr->a4;
28 fl4->flowi4_dscp = params->dscp;
29 fl4->flowi4_l3mdev = l3mdev_master_ifindex_by_index(net: params->net,
30 ifindex: params->oif);
31 fl4->flowi4_mark = params->mark;
32 if (params->saddr)
33 fl4->saddr = params->saddr->a4;
34 fl4->flowi4_proto = params->ipproto;
35 fl4->uli = params->uli;
36
37 rt = __ip_route_output_key(net: params->net, flp: fl4);
38 if (!IS_ERR(ptr: rt))
39 return &rt->dst;
40
41 return ERR_CAST(ptr: rt);
42}
43
44static struct dst_entry *xfrm4_dst_lookup(const struct xfrm_dst_lookup_params *params)
45{
46 struct flowi4 fl4;
47
48 return __xfrm4_dst_lookup(fl4: &fl4, params);
49}
50
51static int xfrm4_get_saddr(xfrm_address_t *saddr,
52 const struct xfrm_dst_lookup_params *params)
53{
54 struct dst_entry *dst;
55 struct flowi4 fl4;
56
57 dst = __xfrm4_dst_lookup(fl4: &fl4, params);
58 if (IS_ERR(ptr: dst))
59 return -EHOSTUNREACH;
60
61 saddr->a4 = fl4.saddr;
62 dst_release(dst);
63 return 0;
64}
65
66static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
67 const struct flowi *fl)
68{
69 struct rtable *rt = dst_rtable(xdst->route);
70 const struct flowi4 *fl4 = &fl->u.ip4;
71
72 xdst->u.rt.rt_iif = fl4->flowi4_iif;
73
74 xdst->u.dst.dev = dev;
75 netdev_hold(dev, tracker: &xdst->u.dst.dev_tracker, GFP_ATOMIC);
76
77 /* Sheit... I remember I did this right. Apparently,
78 * it was magically lost, so this code needs audit */
79 xdst->u.rt.rt_is_input = rt->rt_is_input;
80 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
81 RTCF_LOCAL);
82 xdst->u.rt.rt_type = rt->rt_type;
83 xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway;
84 xdst->u.rt.rt_gw_family = rt->rt_gw_family;
85 if (rt->rt_gw_family == AF_INET)
86 xdst->u.rt.rt_gw4 = rt->rt_gw4;
87 else if (rt->rt_gw_family == AF_INET6)
88 xdst->u.rt.rt_gw6 = rt->rt_gw6;
89 xdst->u.rt.rt_pmtu = rt->rt_pmtu;
90 xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked;
91 rt_add_uncached_list(rt: &xdst->u.rt);
92
93 return 0;
94}
95
96static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk,
97 struct sk_buff *skb, u32 mtu,
98 bool confirm_neigh)
99{
100 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
101 struct dst_entry *path = xdst->route;
102
103 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
104}
105
106static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk,
107 struct sk_buff *skb)
108{
109 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
110 struct dst_entry *path = xdst->route;
111
112 path->ops->redirect(path, sk, skb);
113}
114
115static void xfrm4_dst_destroy(struct dst_entry *dst)
116{
117 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
118
119 dst_destroy_metrics_generic(dst);
120 rt_del_uncached_list(rt: &xdst->u.rt);
121 xfrm_dst_destroy(xdst);
122}
123
124static struct dst_ops xfrm4_dst_ops_template = {
125 .family = AF_INET,
126 .update_pmtu = xfrm4_update_pmtu,
127 .redirect = xfrm4_redirect,
128 .cow_metrics = dst_cow_metrics_generic,
129 .destroy = xfrm4_dst_destroy,
130 .ifdown = xfrm_dst_ifdown,
131 .local_out = __ip_local_out,
132 .gc_thresh = 32768,
133};
134
135static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
136 .dst_ops = &xfrm4_dst_ops_template,
137 .dst_lookup = xfrm4_dst_lookup,
138 .get_saddr = xfrm4_get_saddr,
139 .fill_dst = xfrm4_fill_dst,
140 .blackhole_route = ipv4_blackhole_route,
141};
142
143#ifdef CONFIG_SYSCTL
144static struct ctl_table xfrm4_policy_table[] = {
145 {
146 .procname = "xfrm4_gc_thresh",
147 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
148 .maxlen = sizeof(int),
149 .mode = 0644,
150 .proc_handler = proc_dointvec,
151 },
152};
153
154static __net_init int xfrm4_net_sysctl_init(struct net *net)
155{
156 struct ctl_table *table;
157 struct ctl_table_header *hdr;
158
159 table = xfrm4_policy_table;
160 if (!net_eq(net1: net, net2: &init_net)) {
161 table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL);
162 if (!table)
163 goto err_alloc;
164
165 table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh;
166 }
167
168 hdr = register_net_sysctl_sz(net, path: "net/ipv4", table,
169 ARRAY_SIZE(xfrm4_policy_table));
170 if (!hdr)
171 goto err_reg;
172
173 net->ipv4.xfrm4_hdr = hdr;
174 return 0;
175
176err_reg:
177 if (!net_eq(net1: net, net2: &init_net))
178 kfree(objp: table);
179err_alloc:
180 return -ENOMEM;
181}
182
183static __net_exit void xfrm4_net_sysctl_exit(struct net *net)
184{
185 const struct ctl_table *table;
186
187 if (!net->ipv4.xfrm4_hdr)
188 return;
189
190 table = net->ipv4.xfrm4_hdr->ctl_table_arg;
191 unregister_net_sysctl_table(header: net->ipv4.xfrm4_hdr);
192 if (!net_eq(net1: net, net2: &init_net))
193 kfree(objp: table);
194}
195#else /* CONFIG_SYSCTL */
196static inline int xfrm4_net_sysctl_init(struct net *net)
197{
198 return 0;
199}
200
201static inline void xfrm4_net_sysctl_exit(struct net *net)
202{
203}
204#endif
205
206static int __net_init xfrm4_net_init(struct net *net)
207{
208 int ret;
209
210 memcpy(to: &net->xfrm.xfrm4_dst_ops, from: &xfrm4_dst_ops_template,
211 len: sizeof(xfrm4_dst_ops_template));
212 ret = dst_entries_init(dst: &net->xfrm.xfrm4_dst_ops);
213 if (ret)
214 return ret;
215
216 ret = xfrm4_net_sysctl_init(net);
217 if (ret)
218 dst_entries_destroy(dst: &net->xfrm.xfrm4_dst_ops);
219
220 return ret;
221}
222
223static void __net_exit xfrm4_net_exit(struct net *net)
224{
225 xfrm4_net_sysctl_exit(net);
226 dst_entries_destroy(dst: &net->xfrm.xfrm4_dst_ops);
227}
228
229static struct pernet_operations __net_initdata xfrm4_net_ops = {
230 .init = xfrm4_net_init,
231 .exit = xfrm4_net_exit,
232};
233
234static void __init xfrm4_policy_init(void)
235{
236 xfrm_policy_register_afinfo(afinfo: &xfrm4_policy_afinfo, AF_INET);
237}
238
239void __init xfrm4_init(void)
240{
241 xfrm4_state_init();
242 xfrm4_policy_init();
243 xfrm4_protocol_init();
244 register_pernet_subsys(&xfrm4_net_ops);
245}
246