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