1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * xfrm6_policy.c: based on xfrm4_policy.c 4 * 5 * Authors: 6 * Mitsuru KANDA @USAGI 7 * Kazunori MIYAZAWA @USAGI 8 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 9 * IPv6 support 10 * YOSHIFUJI Hideaki 11 * Split up af-specific portion 12 * 13 */ 14 15 #include <linux/err.h> 16 #include <linux/kernel.h> 17 #include <linux/netdevice.h> 18 #include <net/addrconf.h> 19 #include <net/dst.h> 20 #include <net/xfrm.h> 21 #include <net/ip.h> 22 #include <net/ipv6.h> 23 #include <net/ip6_route.h> 24 #include <net/l3mdev.h> 25 26 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif, 27 const xfrm_address_t *saddr, 28 const xfrm_address_t *daddr, 29 u32 mark) 30 { 31 struct flowi6 fl6; 32 struct dst_entry *dst; 33 int err; 34 35 memset(&fl6, 0, sizeof(fl6)); 36 fl6.flowi6_oif = l3mdev_master_ifindex_by_index(net, oif); 37 fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF; 38 fl6.flowi6_mark = mark; 39 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr)); 40 if (saddr) 41 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr)); 42 43 dst = ip6_route_output(net, NULL, &fl6); 44 45 err = dst->error; 46 if (dst->error) { 47 dst_release(dst); 48 dst = ERR_PTR(err); 49 } 50 51 return dst; 52 } 53 54 static int xfrm6_get_saddr(struct net *net, int oif, 55 xfrm_address_t *saddr, xfrm_address_t *daddr, 56 u32 mark) 57 { 58 struct dst_entry *dst; 59 struct net_device *dev; 60 61 dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark); 62 if (IS_ERR(dst)) 63 return -EHOSTUNREACH; 64 65 dev = ip6_dst_idev(dst)->dev; 66 ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6); 67 dst_release(dst); 68 return 0; 69 } 70 71 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 72 const struct flowi *fl) 73 { 74 struct rt6_info *rt = (struct rt6_info *)xdst->route; 75 76 xdst->u.dst.dev = dev; 77 dev_hold(dev); 78 79 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 80 if (!xdst->u.rt6.rt6i_idev) { 81 dev_put(dev); 82 return -ENODEV; 83 } 84 85 /* Sheit... I remember I did this right. Apparently, 86 * it was magically lost, so this code needs audit */ 87 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 88 RTF_LOCAL); 89 xdst->route_cookie = rt6_get_cookie(rt); 90 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 91 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 92 xdst->u.rt6.rt6i_src = rt->rt6i_src; 93 INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached); 94 rt6_uncached_list_add(&xdst->u.rt6); 95 atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache); 96 97 return 0; 98 } 99 100 static void xfrm6_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 xfrm6_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 xfrm6_dst_destroy(struct dst_entry *dst) 120 { 121 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 122 123 if (likely(xdst->u.rt6.rt6i_idev)) 124 in6_dev_put(xdst->u.rt6.rt6i_idev); 125 dst_destroy_metrics_generic(dst); 126 if (xdst->u.rt6.rt6i_uncached_list) 127 rt6_uncached_list_del(&xdst->u.rt6); 128 xfrm_dst_destroy(xdst); 129 } 130 131 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 132 int unregister) 133 { 134 struct xfrm_dst *xdst; 135 136 if (!unregister) 137 return; 138 139 xdst = (struct xfrm_dst *)dst; 140 if (xdst->u.rt6.rt6i_idev->dev == dev) { 141 struct inet6_dev *loopback_idev = 142 in6_dev_get(dev_net(dev)->loopback_dev); 143 144 do { 145 in6_dev_put(xdst->u.rt6.rt6i_idev); 146 xdst->u.rt6.rt6i_idev = loopback_idev; 147 in6_dev_hold(loopback_idev); 148 xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst); 149 } while (xdst->u.dst.xfrm); 150 151 __in6_dev_put(loopback_idev); 152 } 153 154 xfrm_dst_ifdown(dst, dev); 155 } 156 157 static struct dst_ops xfrm6_dst_ops_template = { 158 .family = AF_INET6, 159 .update_pmtu = xfrm6_update_pmtu, 160 .redirect = xfrm6_redirect, 161 .cow_metrics = dst_cow_metrics_generic, 162 .destroy = xfrm6_dst_destroy, 163 .ifdown = xfrm6_dst_ifdown, 164 .local_out = __ip6_local_out, 165 .gc_thresh = 32768, 166 }; 167 168 static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 169 .dst_ops = &xfrm6_dst_ops_template, 170 .dst_lookup = xfrm6_dst_lookup, 171 .get_saddr = xfrm6_get_saddr, 172 .fill_dst = xfrm6_fill_dst, 173 .blackhole_route = ip6_blackhole_route, 174 }; 175 176 static int __init xfrm6_policy_init(void) 177 { 178 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6); 179 } 180 181 static void xfrm6_policy_fini(void) 182 { 183 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 184 } 185 186 #ifdef CONFIG_SYSCTL 187 static struct ctl_table xfrm6_policy_table[] = { 188 { 189 .procname = "xfrm6_gc_thresh", 190 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 191 .maxlen = sizeof(int), 192 .mode = 0644, 193 .proc_handler = proc_dointvec, 194 }, 195 { } 196 }; 197 198 static int __net_init xfrm6_net_sysctl_init(struct net *net) 199 { 200 struct ctl_table *table; 201 struct ctl_table_header *hdr; 202 203 table = xfrm6_policy_table; 204 if (!net_eq(net, &init_net)) { 205 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 206 if (!table) 207 goto err_alloc; 208 209 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 210 } 211 212 hdr = register_net_sysctl(net, "net/ipv6", table); 213 if (!hdr) 214 goto err_reg; 215 216 net->ipv6.sysctl.xfrm6_hdr = hdr; 217 return 0; 218 219 err_reg: 220 if (!net_eq(net, &init_net)) 221 kfree(table); 222 err_alloc: 223 return -ENOMEM; 224 } 225 226 static void __net_exit xfrm6_net_sysctl_exit(struct net *net) 227 { 228 struct ctl_table *table; 229 230 if (!net->ipv6.sysctl.xfrm6_hdr) 231 return; 232 233 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 234 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 235 if (!net_eq(net, &init_net)) 236 kfree(table); 237 } 238 #else /* CONFIG_SYSCTL */ 239 static inline int xfrm6_net_sysctl_init(struct net *net) 240 { 241 return 0; 242 } 243 244 static inline void xfrm6_net_sysctl_exit(struct net *net) 245 { 246 } 247 #endif 248 249 static int __net_init xfrm6_net_init(struct net *net) 250 { 251 int ret; 252 253 memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template, 254 sizeof(xfrm6_dst_ops_template)); 255 ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops); 256 if (ret) 257 return ret; 258 259 ret = xfrm6_net_sysctl_init(net); 260 if (ret) 261 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 262 263 return ret; 264 } 265 266 static void __net_exit xfrm6_net_exit(struct net *net) 267 { 268 xfrm6_net_sysctl_exit(net); 269 dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); 270 } 271 272 static struct pernet_operations xfrm6_net_ops = { 273 .init = xfrm6_net_init, 274 .exit = xfrm6_net_exit, 275 }; 276 277 int __init xfrm6_init(void) 278 { 279 int ret; 280 281 ret = xfrm6_policy_init(); 282 if (ret) 283 goto out; 284 ret = xfrm6_state_init(); 285 if (ret) 286 goto out_policy; 287 288 ret = xfrm6_protocol_init(); 289 if (ret) 290 goto out_state; 291 292 register_pernet_subsys(&xfrm6_net_ops); 293 out: 294 return ret; 295 out_state: 296 xfrm6_state_fini(); 297 out_policy: 298 xfrm6_policy_fini(); 299 goto out; 300 } 301 302 void xfrm6_fini(void) 303 { 304 unregister_pernet_subsys(&xfrm6_net_ops); 305 xfrm6_protocol_fini(); 306 xfrm6_policy_fini(); 307 xfrm6_state_fini(); 308 } 309