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_oif = l3mdev_master_ifindex_by_index(net, oif); 32 fl4->flowi4_mark = mark; 33 if (saddr) 34 fl4->saddr = saddr->a4; 35 36 fl4->flowi4_flags = FLOWI_FLAG_SKIP_NH_OIF; 37 38 rt = __ip_route_output_key(net, fl4); 39 if (!IS_ERR(rt)) 40 return &rt->dst; 41 42 return ERR_CAST(rt); 43 } 44 45 static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos, int oif, 46 const xfrm_address_t *saddr, 47 const xfrm_address_t *daddr, 48 u32 mark) 49 { 50 struct flowi4 fl4; 51 52 return __xfrm4_dst_lookup(net, &fl4, tos, oif, saddr, daddr, mark); 53 } 54 55 static int xfrm4_get_saddr(struct net *net, int oif, 56 xfrm_address_t *saddr, xfrm_address_t *daddr, 57 u32 mark) 58 { 59 struct dst_entry *dst; 60 struct flowi4 fl4; 61 62 dst = __xfrm4_dst_lookup(net, &fl4, 0, oif, NULL, daddr, mark); 63 if (IS_ERR(dst)) 64 return -EHOSTUNREACH; 65 66 saddr->a4 = fl4.saddr; 67 dst_release(dst); 68 return 0; 69 } 70 71 static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 72 const struct flowi *fl) 73 { 74 struct rtable *rt = (struct rtable *)xdst->route; 75 const struct flowi4 *fl4 = &fl->u.ip4; 76 77 xdst->u.rt.rt_iif = fl4->flowi4_iif; 78 79 xdst->u.dst.dev = dev; 80 dev_hold(dev); 81 82 /* Sheit... I remember I did this right. Apparently, 83 * it was magically lost, so this code needs audit */ 84 xdst->u.rt.rt_is_input = rt->rt_is_input; 85 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | 86 RTCF_LOCAL); 87 xdst->u.rt.rt_type = rt->rt_type; 88 xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway; 89 xdst->u.rt.rt_gw_family = rt->rt_gw_family; 90 if (rt->rt_gw_family == AF_INET) 91 xdst->u.rt.rt_gw4 = rt->rt_gw4; 92 else if (rt->rt_gw_family == AF_INET6) 93 xdst->u.rt.rt_gw6 = rt->rt_gw6; 94 xdst->u.rt.rt_pmtu = rt->rt_pmtu; 95 xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked; 96 INIT_LIST_HEAD(&xdst->u.rt.rt_uncached); 97 rt_add_uncached_list(&xdst->u.rt); 98 99 return 0; 100 } 101 102 static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, 103 struct sk_buff *skb, u32 mtu) 104 { 105 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 106 struct dst_entry *path = xdst->route; 107 108 path->ops->update_pmtu(path, sk, skb, mtu); 109 } 110 111 static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, 112 struct sk_buff *skb) 113 { 114 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 115 struct dst_entry *path = xdst->route; 116 117 path->ops->redirect(path, sk, skb); 118 } 119 120 static void xfrm4_dst_destroy(struct dst_entry *dst) 121 { 122 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 123 124 dst_destroy_metrics_generic(dst); 125 if (xdst->u.rt.rt_uncached_list) 126 rt_del_uncached_list(&xdst->u.rt); 127 xfrm_dst_destroy(xdst); 128 } 129 130 static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 131 int unregister) 132 { 133 if (!unregister) 134 return; 135 136 xfrm_dst_ifdown(dst, dev); 137 } 138 139 static struct dst_ops xfrm4_dst_ops_template = { 140 .family = AF_INET, 141 .update_pmtu = xfrm4_update_pmtu, 142 .redirect = xfrm4_redirect, 143 .cow_metrics = dst_cow_metrics_generic, 144 .destroy = xfrm4_dst_destroy, 145 .ifdown = xfrm4_dst_ifdown, 146 .local_out = __ip_local_out, 147 .gc_thresh = 32768, 148 }; 149 150 static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = { 151 .dst_ops = &xfrm4_dst_ops_template, 152 .dst_lookup = xfrm4_dst_lookup, 153 .get_saddr = xfrm4_get_saddr, 154 .fill_dst = xfrm4_fill_dst, 155 .blackhole_route = ipv4_blackhole_route, 156 }; 157 158 #ifdef CONFIG_SYSCTL 159 static struct ctl_table xfrm4_policy_table[] = { 160 { 161 .procname = "xfrm4_gc_thresh", 162 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, 163 .maxlen = sizeof(int), 164 .mode = 0644, 165 .proc_handler = proc_dointvec, 166 }, 167 { } 168 }; 169 170 static __net_init int xfrm4_net_sysctl_init(struct net *net) 171 { 172 struct ctl_table *table; 173 struct ctl_table_header *hdr; 174 175 table = xfrm4_policy_table; 176 if (!net_eq(net, &init_net)) { 177 table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); 178 if (!table) 179 goto err_alloc; 180 181 table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; 182 } 183 184 hdr = register_net_sysctl(net, "net/ipv4", table); 185 if (!hdr) 186 goto err_reg; 187 188 net->ipv4.xfrm4_hdr = hdr; 189 return 0; 190 191 err_reg: 192 if (!net_eq(net, &init_net)) 193 kfree(table); 194 err_alloc: 195 return -ENOMEM; 196 } 197 198 static __net_exit void xfrm4_net_sysctl_exit(struct net *net) 199 { 200 struct ctl_table *table; 201 202 if (!net->ipv4.xfrm4_hdr) 203 return; 204 205 table = net->ipv4.xfrm4_hdr->ctl_table_arg; 206 unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); 207 if (!net_eq(net, &init_net)) 208 kfree(table); 209 } 210 #else /* CONFIG_SYSCTL */ 211 static inline int xfrm4_net_sysctl_init(struct net *net) 212 { 213 return 0; 214 } 215 216 static inline void xfrm4_net_sysctl_exit(struct net *net) 217 { 218 } 219 #endif 220 221 static int __net_init xfrm4_net_init(struct net *net) 222 { 223 int ret; 224 225 memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template, 226 sizeof(xfrm4_dst_ops_template)); 227 ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops); 228 if (ret) 229 return ret; 230 231 ret = xfrm4_net_sysctl_init(net); 232 if (ret) 233 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 234 235 return ret; 236 } 237 238 static void __net_exit xfrm4_net_exit(struct net *net) 239 { 240 xfrm4_net_sysctl_exit(net); 241 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 242 } 243 244 static struct pernet_operations __net_initdata xfrm4_net_ops = { 245 .init = xfrm4_net_init, 246 .exit = xfrm4_net_exit, 247 }; 248 249 static void __init xfrm4_policy_init(void) 250 { 251 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo, AF_INET); 252 } 253 254 void __init xfrm4_init(void) 255 { 256 xfrm4_state_init(); 257 xfrm4_policy_init(); 258 xfrm4_protocol_init(); 259 register_pernet_subsys(&xfrm4_net_ops); 260 } 261