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 flowi4 *fl4, 21 const struct xfrm_dst_lookup_params *params) 22 { 23 struct rtable *rt; 24 25 memset(fl4, 0, sizeof(*fl4)); 26 fl4->daddr = params->daddr->a4; 27 fl4->flowi4_tos = params->tos; 28 fl4->flowi4_l3mdev = l3mdev_master_ifindex_by_index(params->net, 29 params->oif); 30 fl4->flowi4_mark = params->mark; 31 if (params->saddr) 32 fl4->saddr = params->saddr->a4; 33 fl4->flowi4_proto = params->ipproto; 34 fl4->uli = params->uli; 35 36 rt = __ip_route_output_key(params->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(const struct xfrm_dst_lookup_params *params) 44 { 45 struct flowi4 fl4; 46 47 return __xfrm4_dst_lookup(&fl4, params); 48 } 49 50 static int xfrm4_get_saddr(xfrm_address_t *saddr, 51 const struct xfrm_dst_lookup_params *params) 52 { 53 struct dst_entry *dst; 54 struct flowi4 fl4; 55 56 dst = __xfrm4_dst_lookup(&fl4, params); 57 if (IS_ERR(dst)) 58 return -EHOSTUNREACH; 59 60 saddr->a4 = fl4.saddr; 61 dst_release(dst); 62 return 0; 63 } 64 65 static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 66 const struct flowi *fl) 67 { 68 struct rtable *rt = dst_rtable(xdst->route); 69 const struct flowi4 *fl4 = &fl->u.ip4; 70 71 xdst->u.rt.rt_iif = fl4->flowi4_iif; 72 73 xdst->u.dst.dev = dev; 74 netdev_hold(dev, &xdst->u.dst.dev_tracker, GFP_ATOMIC); 75 76 /* Sheit... I remember I did this right. Apparently, 77 * it was magically lost, so this code needs audit */ 78 xdst->u.rt.rt_is_input = rt->rt_is_input; 79 xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | 80 RTCF_LOCAL); 81 xdst->u.rt.rt_type = rt->rt_type; 82 xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway; 83 xdst->u.rt.rt_gw_family = rt->rt_gw_family; 84 if (rt->rt_gw_family == AF_INET) 85 xdst->u.rt.rt_gw4 = rt->rt_gw4; 86 else if (rt->rt_gw_family == AF_INET6) 87 xdst->u.rt.rt_gw6 = rt->rt_gw6; 88 xdst->u.rt.rt_pmtu = rt->rt_pmtu; 89 xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked; 90 rt_add_uncached_list(&xdst->u.rt); 91 92 return 0; 93 } 94 95 static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, 96 struct sk_buff *skb, u32 mtu, 97 bool confirm_neigh) 98 { 99 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 100 struct dst_entry *path = xdst->route; 101 102 path->ops->update_pmtu(path, sk, skb, mtu, confirm_neigh); 103 } 104 105 static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, 106 struct sk_buff *skb) 107 { 108 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 109 struct dst_entry *path = xdst->route; 110 111 path->ops->redirect(path, sk, skb); 112 } 113 114 static void xfrm4_dst_destroy(struct dst_entry *dst) 115 { 116 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 117 118 dst_destroy_metrics_generic(dst); 119 rt_del_uncached_list(&xdst->u.rt); 120 xfrm_dst_destroy(xdst); 121 } 122 123 static struct dst_ops xfrm4_dst_ops_template = { 124 .family = AF_INET, 125 .update_pmtu = xfrm4_update_pmtu, 126 .redirect = xfrm4_redirect, 127 .cow_metrics = dst_cow_metrics_generic, 128 .destroy = xfrm4_dst_destroy, 129 .ifdown = xfrm_dst_ifdown, 130 .local_out = __ip_local_out, 131 .gc_thresh = 32768, 132 }; 133 134 static const struct xfrm_policy_afinfo xfrm4_policy_afinfo = { 135 .dst_ops = &xfrm4_dst_ops_template, 136 .dst_lookup = xfrm4_dst_lookup, 137 .get_saddr = xfrm4_get_saddr, 138 .fill_dst = xfrm4_fill_dst, 139 .blackhole_route = ipv4_blackhole_route, 140 }; 141 142 #ifdef CONFIG_SYSCTL 143 static struct ctl_table xfrm4_policy_table[] = { 144 { 145 .procname = "xfrm4_gc_thresh", 146 .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, 147 .maxlen = sizeof(int), 148 .mode = 0644, 149 .proc_handler = proc_dointvec, 150 }, 151 }; 152 153 static __net_init int xfrm4_net_sysctl_init(struct net *net) 154 { 155 struct ctl_table *table; 156 struct ctl_table_header *hdr; 157 158 table = xfrm4_policy_table; 159 if (!net_eq(net, &init_net)) { 160 table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); 161 if (!table) 162 goto err_alloc; 163 164 table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; 165 } 166 167 hdr = register_net_sysctl_sz(net, "net/ipv4", table, 168 ARRAY_SIZE(xfrm4_policy_table)); 169 if (!hdr) 170 goto err_reg; 171 172 net->ipv4.xfrm4_hdr = hdr; 173 return 0; 174 175 err_reg: 176 if (!net_eq(net, &init_net)) 177 kfree(table); 178 err_alloc: 179 return -ENOMEM; 180 } 181 182 static __net_exit void xfrm4_net_sysctl_exit(struct net *net) 183 { 184 const struct ctl_table *table; 185 186 if (!net->ipv4.xfrm4_hdr) 187 return; 188 189 table = net->ipv4.xfrm4_hdr->ctl_table_arg; 190 unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); 191 if (!net_eq(net, &init_net)) 192 kfree(table); 193 } 194 #else /* CONFIG_SYSCTL */ 195 static inline int xfrm4_net_sysctl_init(struct net *net) 196 { 197 return 0; 198 } 199 200 static inline void xfrm4_net_sysctl_exit(struct net *net) 201 { 202 } 203 #endif 204 205 static int __net_init xfrm4_net_init(struct net *net) 206 { 207 int ret; 208 209 memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template, 210 sizeof(xfrm4_dst_ops_template)); 211 ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops); 212 if (ret) 213 return ret; 214 215 ret = xfrm4_net_sysctl_init(net); 216 if (ret) 217 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 218 219 return ret; 220 } 221 222 static void __net_exit xfrm4_net_exit(struct net *net) 223 { 224 xfrm4_net_sysctl_exit(net); 225 dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); 226 } 227 228 static struct pernet_operations __net_initdata xfrm4_net_ops = { 229 .init = xfrm4_net_init, 230 .exit = xfrm4_net_exit, 231 }; 232 233 static void __init xfrm4_policy_init(void) 234 { 235 xfrm_policy_register_afinfo(&xfrm4_policy_afinfo, AF_INET); 236 } 237 238 void __init xfrm4_init(void) 239 { 240 xfrm4_state_init(); 241 xfrm4_policy_init(); 242 xfrm4_protocol_init(); 243 register_pernet_subsys(&xfrm4_net_ops); 244 } 245