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 | |
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, ifindex: oif); |
32 | fl4->flowi4_mark = mark; |
33 | if (saddr) |
34 | fl4->saddr = saddr->a4; |
35 | |
36 | rt = __ip_route_output_key(net, flp: fl4); |
37 | if (!IS_ERR(ptr: rt)) |
38 | return &rt->dst; |
39 | |
40 | return ERR_CAST(ptr: rt); |
41 | } |
42 | |
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: &fl4, tos, oif, saddr, daddr, mark); |
51 | } |
52 | |
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: &fl4, tos: 0, oif, NULL, daddr, mark); |
61 | if (IS_ERR(ptr: dst)) |
62 | return -EHOSTUNREACH; |
63 | |
64 | saddr->a4 = fl4.saddr; |
65 | dst_release(dst); |
66 | return 0; |
67 | } |
68 | |
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, tracker: &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(rt: &xdst->u.rt); |
95 | |
96 | return 0; |
97 | } |
98 | |
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 | |
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 | |
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(rt: &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 | |
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(net1: net, net2: &init_net)) { |
165 | table = kmemdup(p: table, size: 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, path: "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(net1: net, net2: &init_net)) |
182 | kfree(objp: table); |
183 | err_alloc: |
184 | return -ENOMEM; |
185 | } |
186 | |
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(header: net->ipv4.xfrm4_hdr); |
196 | if (!net_eq(net1: net, net2: &init_net)) |
197 | kfree(objp: table); |
198 | } |
199 | #else /* CONFIG_SYSCTL */ |
200 | static inline int xfrm4_net_sysctl_init(struct net *net) |
201 | { |
202 | return 0; |
203 | } |
204 | |
205 | static inline void xfrm4_net_sysctl_exit(struct net *net) |
206 | { |
207 | } |
208 | #endif |
209 | |
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(dst: &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(dst: &net->xfrm.xfrm4_dst_ops); |
223 | |
224 | return ret; |
225 | } |
226 | |
227 | static void __net_exit xfrm4_net_exit(struct net *net) |
228 | { |
229 | xfrm4_net_sysctl_exit(net); |
230 | dst_entries_destroy(dst: &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 | |
238 | static void __init xfrm4_policy_init(void) |
239 | { |
240 | xfrm_policy_register_afinfo(afinfo: &xfrm4_policy_afinfo, AF_INET); |
241 | } |
242 | |
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 | |