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, 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 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 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 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 dev_hold_track(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 INIT_LIST_HEAD(&xdst->u.rt.rt_uncached); 95 rt_add_uncached_list(&xdst->u.rt); 96 97 return 0; 98 } 99 100 static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, 101 struct sk_buff *skb, u32 mtu, 102 bool confirm_neigh) 103 { 104 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 105 struct dst_entry *path = xdst->route; 106 107 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh); 108 } 109 110 static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, 111 struct sk_buff *skb) 112 { 113 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 114 struct dst_entry *path = xdst->route; 115 116 path->ops->redirect(path, sk, skb); 117 } 118 119 static void xfrm4_dst_destroy(struct dst_entry *dst) 120 { 121 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 122 123 dst_destroy_metrics_generic(dst); 124 if (xdst->u.rt.rt_uncached_list) 125 rt_del_uncached_list(&xdst->u.rt); 126 xfrm_dst_destroy(xdst); 127 } 128 129 static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 130 int unregister) 131 { 132 if (!unregister) 133 return; 134 135 xfrm_dst_ifdown(dst, dev); 136 } 137 138 static struct dst_ops xfrm4_dst_ops_template = { 139 .family = AF_INET, 140 .update_pmtu = xfrm4_update_pmtu, 141 .redirect = xfrm4_redirect, 142 .cow_metrics = dst_cow_metrics_generic, 143 .destroy = xfrm4_dst_destroy, 144 .ifdown = xfrm4_dst_ifdown, 145 .local_out = __ip_local_out, 146 .gc_thresh = 32768, 147 }; 148 149 static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = { 150 .dst_ops = &xfrm4_dst_ops_template, 151 .dst_lookup = xfrm4_dst_lookup, 152 .get_saddr = xfrm4_get_saddr, 153 .fill_dst = xfrm4_fill_dst, 154 .blackhole_route = ipv4_blackhole_route, 155 }; 156 157 #ifdef CONFIG_SYSCTL 158 static struct ctl_table xfrm4_policy_table[] = { 159 { 160 .procname = "xfrm4_gc_thresh", 161 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, 162 .maxlen = sizeof(int), 163 .mode = 0644, 164 .proc_handler = proc_dointvec, 165 }, 166 { } 167 }; 168 169 static __net_init int xfrm4_net_sysctl_init(struct net *net) 170 { 171 struct ctl_table *table; 172 struct ctl_table_header *hdr; 173 174 table = xfrm4_policy_table; 175 if (!net_eq(net, &init_net)) { 176 table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); 177 if (!table) 178 goto err_alloc; 179 180 table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; 181 } 182 183 hdr = register_net_sysctl(net, "net/ipv4", table); 184 if (!hdr) 185 goto err_reg; 186 187 net->ipv4.xfrm4_hdr = hdr; 188 return 0; 189 190 err_reg: 191 if (!net_eq(net, &init_net)) 192 kfree(table); 193 err_alloc: 194 return -ENOMEM; 195 } 196 197 static __net_exit void xfrm4_net_sysctl_exit(struct net *net) 198 { 199 struct ctl_table *table; 200 201 if (!net->ipv4.xfrm4_hdr) 202 return; 203 204 table = net->ipv4.xfrm4_hdr->ctl_table_arg; 205 unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); 206 if (!net_eq(net, &init_net)) 207 kfree(table); 208 } 209 #else /* CONFIG_SYSCTL */ 210 static inline int xfrm4_net_sysctl_init(struct net *net) 211 { 212 return 0; 213 } 214 215 static inline void xfrm4_net_sysctl_exit(struct net *net) 216 { 217 } 218 #endif 219 220 static int __net_init xfrm4_net_init(struct net *net) 221 { 222 int ret; 223 224 memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template, 225 sizeof(xfrm4_dst_ops_template)); 226 ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops); 227 if (ret) 228 return ret; 229 230 ret = xfrm4_net_sysctl_init(net); 231 if (ret) 232 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 233 234 return ret; 235 } 236 237 static void __net_exit xfrm4_net_exit(struct net *net) 238 { 239 xfrm4_net_sysctl_exit(net); 240 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 241 } 242 243 static struct pernet_operations __net_initdata xfrm4_net_ops = { 244 .init = xfrm4_net_init, 245 .exit = xfrm4_net_exit, 246 }; 247 248 static void __init xfrm4_policy_init(void) 249 { 250 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo, AF_INET); 251 } 252 253 void __init xfrm4_init(void) 254 { 255 xfrm4_state_init(); 256 xfrm4_policy_init(); 257 xfrm4_protocol_init(); 258 register_pernet_subsys(&xfrm4_net_ops); 259 } 260