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/flow.h> 18 #include <net/ip.h> 19 #include <net/l3mdev.h> 20 21 static struct dst_entry *__xfrm4_dst_lookup(struct flowi4 *fl4, 22 const struct xfrm_dst_lookup_params *params) 23 { 24 struct rtable *rt; 25 26 memset(fl4, 0, sizeof(*fl4)); 27 fl4->daddr = params->daddr->a4; 28 fl4->flowi4_dscp = params->dscp; 29 fl4->flowi4_l3mdev = l3mdev_master_ifindex_by_index(params->net, 30 params->oif); 31 fl4->flowi4_mark = params->mark; 32 if (params->saddr) 33 fl4->saddr = params->saddr->a4; 34 fl4->flowi4_proto = params->ipproto; 35 fl4->uli = params->uli; 36 37 rt = __ip_route_output_key(params->net, fl4); 38 if (!IS_ERR(rt)) 39 return &rt->dst; 40 41 return ERR_CAST(rt); 42 } 43 44 static struct dst_entry *xfrm4_dst_lookup(const struct xfrm_dst_lookup_params *params) 45 { 46 struct flowi4 fl4; 47 48 return __xfrm4_dst_lookup(&fl4, params); 49 } 50 51 static int xfrm4_get_saddr(xfrm_address_t *saddr, 52 const struct xfrm_dst_lookup_params *params) 53 { 54 struct dst_entry *dst; 55 struct flowi4 fl4; 56 57 dst = __xfrm4_dst_lookup(&fl4, params); 58 if (IS_ERR(dst)) 59 return -EHOSTUNREACH; 60 61 saddr->a4 = fl4.saddr; 62 dst_release(dst); 63 return 0; 64 } 65 66 static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 67 const struct flowi *fl) 68 { 69 struct rtable *rt = dst_rtable(xdst->route); 70 const struct flowi4 *fl4 = &fl->u.ip4; 71 72 xdst->u.rt.rt_iif = fl4->flowi4_iif; 73 74 xdst->u.dst.dev = dev; 75 netdev_hold(dev, &xdst->u.dst.dev_tracker, GFP_ATOMIC); 76 77 /* Sheit... I remember I did this right. Apparently, 78 * it was magically lost, so this code needs audit */ 79 xdst->u.rt.rt_is_input = rt->rt_is_input; 80 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | 81 RTCF_LOCAL); 82 xdst->u.rt.rt_type = rt->rt_type; 83 xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway; 84 xdst->u.rt.rt_gw_family = rt->rt_gw_family; 85 if (rt->rt_gw_family == AF_INET) 86 xdst->u.rt.rt_gw4 = rt->rt_gw4; 87 else if (rt->rt_gw_family == AF_INET6) 88 xdst->u.rt.rt_gw6 = rt->rt_gw6; 89 xdst->u.rt.rt_pmtu = rt->rt_pmtu; 90 xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked; 91 rt_add_uncached_list(&xdst->u.rt); 92 93 return 0; 94 } 95 96 static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, 97 struct sk_buff *skb, u32 mtu, 98 bool confirm_neigh) 99 { 100 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 101 struct dst_entry *path = xdst->route; 102 103 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh); 104 } 105 106 static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, 107 struct sk_buff *skb) 108 { 109 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 110 struct dst_entry *path = xdst->route; 111 112 path->ops->redirect(path, sk, skb); 113 } 114 115 static void xfrm4_dst_destroy(struct dst_entry *dst) 116 { 117 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 118 119 dst_destroy_metrics_generic(dst); 120 rt_del_uncached_list(&xdst->u.rt); 121 xfrm_dst_destroy(xdst); 122 } 123 124 static struct dst_ops xfrm4_dst_ops_template = { 125 .family = AF_INET, 126 .update_pmtu = xfrm4_update_pmtu, 127 .redirect = xfrm4_redirect, 128 .cow_metrics = dst_cow_metrics_generic, 129 .destroy = xfrm4_dst_destroy, 130 .ifdown = xfrm_dst_ifdown, 131 .local_out = __ip_local_out, 132 .gc_thresh = 32768, 133 }; 134 135 static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = { 136 .dst_ops = &xfrm4_dst_ops_template, 137 .dst_lookup = xfrm4_dst_lookup, 138 .get_saddr = xfrm4_get_saddr, 139 .fill_dst = xfrm4_fill_dst, 140 .blackhole_route = ipv4_blackhole_route, 141 }; 142 143 #ifdef CONFIG_SYSCTL 144 static const struct ctl_table xfrm4_policy_table[] = { 145 { 146 .procname = "xfrm4_gc_thresh", 147 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, 148 .maxlen = sizeof(int), 149 .mode = 0644, 150 .proc_handler = proc_dointvec, 151 }, 152 }; 153 154 static const struct ctl_table *xfrm4_policy_table_dup(struct net *net) 155 { 156 struct ctl_table *table; 157 158 table = kmemdup(xfrm4_policy_table, sizeof(xfrm4_policy_table), 159 GFP_KERNEL); 160 if (!table) 161 return NULL; 162 163 table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; 164 165 return table; 166 } 167 168 static __net_init int xfrm4_net_sysctl_init(struct net *net) 169 { 170 const struct ctl_table *table; 171 struct ctl_table_header *hdr; 172 173 table = xfrm4_policy_table; 174 if (!net_eq(net, &init_net)) { 175 table = xfrm4_policy_table_dup(net); 176 if (!table) 177 goto err_alloc; 178 } 179 180 hdr = register_net_sysctl_sz(net, "net/ipv4", table, 181 ARRAY_SIZE(xfrm4_policy_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 const 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