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/ip.h>
18 #include <net/l3mdev.h>
19
__xfrm4_dst_lookup(struct net * net,struct flowi4 * fl4,int tos,int oif,const xfrm_address_t * saddr,const xfrm_address_t * daddr,u32 mark)20 static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4,
21 int tos, int oif,
22 const xfrm_address_t *saddr,
23 const xfrm_address_t *daddr,
24 u32 mark)
25 {
26 struct rtable *rt;
27
28 memset(fl4, 0, sizeof(*fl4));
29 fl4->daddr = daddr->a4;
30 fl4->flowi4_tos = tos;
31 fl4->flowi4_l3mdev = l3mdev_master_ifindex_by_index(net, oif);
32 fl4->flowi4_mark = mark;
33 if (saddr)
34 fl4->saddr = saddr->a4;
35
36 rt = __ip_route_output_key(net, fl4);
37 if (!IS_ERR(rt))
38 return &rt->dst;
39
40 return ERR_CAST(rt);
41 }
42
xfrm4_dst_lookup(struct net * net,int tos,int oif,const xfrm_address_t * saddr,const xfrm_address_t * daddr,u32 mark)43 static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos, int oif,
44 const xfrm_address_t *saddr,
45 const xfrm_address_t *daddr,
46 u32 mark)
47 {
48 struct flowi4 fl4;
49
50 return __xfrm4_dst_lookup(net, &fl4, tos, oif, saddr, daddr, mark);
51 }
52
xfrm4_get_saddr(struct net * net,int oif,xfrm_address_t * saddr,xfrm_address_t * daddr,u32 mark)53 static int xfrm4_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 flowi4 fl4;
59
60 dst = __xfrm4_dst_lookup(net, &fl4, 0, oif, NULL, daddr, mark);
61 if (IS_ERR(dst))
62 return -EHOSTUNREACH;
63
64 saddr->a4 = fl4.saddr;
65 dst_release(dst);
66 return 0;
67 }
68
xfrm4_fill_dst(struct xfrm_dst * xdst,struct net_device * dev,const struct flowi * fl)69 static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev,
70 const struct flowi *fl)
71 {
72 struct rtable *rt = (struct rtable *)xdst->route;
73 const struct flowi4 *fl4 = &fl->u.ip4;
74
75 xdst->u.rt.rt_iif = fl4->flowi4_iif;
76
77 xdst->u.dst.dev = dev;
78 netdev_hold(dev, &xdst->u.dst.dev_tracker, GFP_ATOMIC);
79
80 /* Sheit... I remember I did this right. Apparently,
81 * it was magically lost, so this code needs audit */
82 xdst->u.rt.rt_is_input = rt->rt_is_input;
83 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
84 RTCF_LOCAL);
85 xdst->u.rt.rt_type = rt->rt_type;
86 xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway;
87 xdst->u.rt.rt_gw_family = rt->rt_gw_family;
88 if (rt->rt_gw_family == AF_INET)
89 xdst->u.rt.rt_gw4 = rt->rt_gw4;
90 else if (rt->rt_gw_family == AF_INET6)
91 xdst->u.rt.rt_gw6 = rt->rt_gw6;
92 xdst->u.rt.rt_pmtu = rt->rt_pmtu;
93 xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked;
94 rt_add_uncached_list(&xdst->u.rt);
95
96 return 0;
97 }
98
xfrm4_update_pmtu(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb,u32 mtu,bool confirm_neigh)99 static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk,
100 struct sk_buff *skb, u32 mtu,
101 bool confirm_neigh)
102 {
103 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
104 struct dst_entry *path = xdst->route;
105
106 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh);
107 }
108
xfrm4_redirect(struct dst_entry * dst,struct sock * sk,struct sk_buff * skb)109 static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk,
110 struct sk_buff *skb)
111 {
112 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
113 struct dst_entry *path = xdst->route;
114
115 path->ops->redirect(path, sk, skb);
116 }
117
xfrm4_dst_destroy(struct dst_entry * dst)118 static void xfrm4_dst_destroy(struct dst_entry *dst)
119 {
120 struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
121
122 dst_destroy_metrics_generic(dst);
123 rt_del_uncached_list(&xdst->u.rt);
124 xfrm_dst_destroy(xdst);
125 }
126
127 static struct dst_ops xfrm4_dst_ops_template = {
128 .family = AF_INET,
129 .update_pmtu = xfrm4_update_pmtu,
130 .redirect = xfrm4_redirect,
131 .cow_metrics = dst_cow_metrics_generic,
132 .destroy = xfrm4_dst_destroy,
133 .ifdown = xfrm_dst_ifdown,
134 .local_out = __ip_local_out,
135 .gc_thresh = 32768,
136 };
137
138 static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
139 .dst_ops = &xfrm4_dst_ops_template,
140 .dst_lookup = xfrm4_dst_lookup,
141 .get_saddr = xfrm4_get_saddr,
142 .fill_dst = xfrm4_fill_dst,
143 .blackhole_route = ipv4_blackhole_route,
144 };
145
146 #ifdef CONFIG_SYSCTL
147 static struct ctl_table xfrm4_policy_table[] = {
148 {
149 .procname = "xfrm4_gc_thresh",
150 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh,
151 .maxlen = sizeof(int),
152 .mode = 0644,
153 .proc_handler = proc_dointvec,
154 },
155 { }
156 };
157
xfrm4_net_sysctl_init(struct net * net)158 static __net_init int xfrm4_net_sysctl_init(struct net *net)
159 {
160 struct ctl_table *table;
161 struct ctl_table_header *hdr;
162
163 table = xfrm4_policy_table;
164 if (!net_eq(net, &init_net)) {
165 table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL);
166 if (!table)
167 goto err_alloc;
168
169 table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh;
170 }
171
172 hdr = register_net_sysctl_sz(net, "net/ipv4", table,
173 ARRAY_SIZE(xfrm4_policy_table));
174 if (!hdr)
175 goto err_reg;
176
177 net->ipv4.xfrm4_hdr = hdr;
178 return 0;
179
180 err_reg:
181 if (!net_eq(net, &init_net))
182 kfree(table);
183 err_alloc:
184 return -ENOMEM;
185 }
186
xfrm4_net_sysctl_exit(struct net * net)187 static __net_exit void xfrm4_net_sysctl_exit(struct net *net)
188 {
189 struct ctl_table *table;
190
191 if (!net->ipv4.xfrm4_hdr)
192 return;
193
194 table = net->ipv4.xfrm4_hdr->ctl_table_arg;
195 unregister_net_sysctl_table(net->ipv4.xfrm4_hdr);
196 if (!net_eq(net, &init_net))
197 kfree(table);
198 }
199 #else /* CONFIG_SYSCTL */
xfrm4_net_sysctl_init(struct net * net)200 static inline int xfrm4_net_sysctl_init(struct net *net)
201 {
202 return 0;
203 }
204
xfrm4_net_sysctl_exit(struct net * net)205 static inline void xfrm4_net_sysctl_exit(struct net *net)
206 {
207 }
208 #endif
209
xfrm4_net_init(struct net * net)210 static int __net_init xfrm4_net_init(struct net *net)
211 {
212 int ret;
213
214 memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template,
215 sizeof(xfrm4_dst_ops_template));
216 ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops);
217 if (ret)
218 return ret;
219
220 ret = xfrm4_net_sysctl_init(net);
221 if (ret)
222 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops);
223
224 return ret;
225 }
226
xfrm4_net_exit(struct net * net)227 static void __net_exit xfrm4_net_exit(struct net *net)
228 {
229 xfrm4_net_sysctl_exit(net);
230 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops);
231 }
232
233 static struct pernet_operations __net_initdata xfrm4_net_ops = {
234 .init = xfrm4_net_init,
235 .exit = xfrm4_net_exit,
236 };
237
xfrm4_policy_init(void)238 static void __init xfrm4_policy_init(void)
239 {
240 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo, AF_INET);
241 }
242
xfrm4_init(void)243 void __init xfrm4_init(void)
244 {
245 xfrm4_state_init();
246 xfrm4_policy_init();
247 xfrm4_protocol_init();
248 register_pernet_subsys(&xfrm4_net_ops);
249 }
250