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_track(dev, &xdst->u.dst.dev_tracker, GFP_ATOMIC); 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 bool confirm_neigh) 105 { 106 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 107 struct dst_entry *path = xdst->route; 108 109 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh); 110 } 111 112 static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, 113 struct sk_buff *skb) 114 { 115 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 116 struct dst_entry *path = xdst->route; 117 118 path->ops->redirect(path, sk, skb); 119 } 120 121 static void xfrm4_dst_destroy(struct dst_entry *dst) 122 { 123 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 124 125 dst_destroy_metrics_generic(dst); 126 if (xdst->u.rt.rt_uncached_list) 127 rt_del_uncached_list(&xdst->u.rt); 128 xfrm_dst_destroy(xdst); 129 } 130 131 static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 132 int unregister) 133 { 134 if (!unregister) 135 return; 136 137 xfrm_dst_ifdown(dst, dev); 138 } 139 140 static struct dst_ops xfrm4_dst_ops_template = { 141 .family = AF_INET, 142 .update_pmtu = xfrm4_update_pmtu, 143 .redirect = xfrm4_redirect, 144 .cow_metrics = dst_cow_metrics_generic, 145 .destroy = xfrm4_dst_destroy, 146 .ifdown = xfrm4_dst_ifdown, 147 .local_out = __ip_local_out, 148 .gc_thresh = 32768, 149 }; 150 151 static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = { 152 .dst_ops = &xfrm4_dst_ops_template, 153 .dst_lookup = xfrm4_dst_lookup, 154 .get_saddr = xfrm4_get_saddr, 155 .fill_dst = xfrm4_fill_dst, 156 .blackhole_route = ipv4_blackhole_route, 157 }; 158 159 #ifdef CONFIG_SYSCTL 160 static struct ctl_table xfrm4_policy_table[] = { 161 { 162 .procname = "xfrm4_gc_thresh", 163 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, 164 .maxlen = sizeof(int), 165 .mode = 0644, 166 .proc_handler = proc_dointvec, 167 }, 168 { } 169 }; 170 171 static __net_init int xfrm4_net_sysctl_init(struct net *net) 172 { 173 struct ctl_table *table; 174 struct ctl_table_header *hdr; 175 176 table = xfrm4_policy_table; 177 if (!net_eq(net, &init_net)) { 178 table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); 179 if (!table) 180 goto err_alloc; 181 182 table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; 183 } 184 185 hdr = register_net_sysctl(net, "net/ipv4", table); 186 if (!hdr) 187 goto err_reg; 188 189 net->ipv4.xfrm4_hdr = hdr; 190 return 0; 191 192 err_reg: 193 if (!net_eq(net, &init_net)) 194 kfree(table); 195 err_alloc: 196 return -ENOMEM; 197 } 198 199 static __net_exit void xfrm4_net_sysctl_exit(struct net *net) 200 { 201 struct ctl_table *table; 202 203 if (!net->ipv4.xfrm4_hdr) 204 return; 205 206 table = net->ipv4.xfrm4_hdr->ctl_table_arg; 207 unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); 208 if (!net_eq(net, &init_net)) 209 kfree(table); 210 } 211 #else /* CONFIG_SYSCTL */ 212 static inline int xfrm4_net_sysctl_init(struct net *net) 213 { 214 return 0; 215 } 216 217 static inline void xfrm4_net_sysctl_exit(struct net *net) 218 { 219 } 220 #endif 221 222 static int __net_init xfrm4_net_init(struct net *net) 223 { 224 int ret; 225 226 memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template, 227 sizeof(xfrm4_dst_ops_template)); 228 ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops); 229 if (ret) 230 return ret; 231 232 ret = xfrm4_net_sysctl_init(net); 233 if (ret) 234 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 235 236 return ret; 237 } 238 239 static void __net_exit xfrm4_net_exit(struct net *net) 240 { 241 xfrm4_net_sysctl_exit(net); 242 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 243 } 244 245 static struct pernet_operations __net_initdata xfrm4_net_ops = { 246 .init = xfrm4_net_init, 247 .exit = xfrm4_net_exit, 248 }; 249 250 static void __init xfrm4_policy_init(void) 251 { 252 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo, AF_INET); 253 } 254 255 void __init xfrm4_init(void) 256 { 257 xfrm4_state_init(); 258 xfrm4_policy_init(); 259 xfrm4_protocol_init(); 260 register_pernet_subsys(&xfrm4_net_ops); 261 } 262