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 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(net, &init_net)) { 165 table = kmemdup(table, 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, "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(net, &init_net)) 182 kfree(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(net->ipv4.xfrm4_hdr); 196 if (!net_eq(net, &init_net)) 197 kfree(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(&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(&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(&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(&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