1 /* 2 * xfrm6_policy.c: based on xfrm4_policy.c 3 * 4 * Authors: 5 * Mitsuru KANDA @USAGI 6 * Kazunori MIYAZAWA @USAGI 7 * Kunihiro Ishiguro <kunihiro@ipinfusion.com> 8 * IPv6 support 9 * YOSHIFUJI Hideaki 10 * Split up af-specific portion 11 * 12 */ 13 14 #include <linux/err.h> 15 #include <linux/kernel.h> 16 #include <linux/netdevice.h> 17 #include <net/addrconf.h> 18 #include <net/dst.h> 19 #include <net/xfrm.h> 20 #include <net/ip.h> 21 #include <net/ipv6.h> 22 #include <net/ip6_route.h> 23 #if IS_ENABLED(CONFIG_IPV6_MIP6) 24 #include <net/mip6.h> 25 #endif 26 27 static struct xfrm_policy_afinfo xfrm6_policy_afinfo; 28 29 static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, 30 const xfrm_address_t *saddr, 31 const xfrm_address_t *daddr) 32 { 33 struct flowi6 fl6; 34 struct dst_entry *dst; 35 int err; 36 37 memset(&fl6, 0, sizeof(fl6)); 38 memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr)); 39 if (saddr) 40 memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr)); 41 42 dst = ip6_route_output(net, NULL, &fl6); 43 44 err = dst->error; 45 if (dst->error) { 46 dst_release(dst); 47 dst = ERR_PTR(err); 48 } 49 50 return dst; 51 } 52 53 static int xfrm6_get_saddr(struct net *net, 54 xfrm_address_t *saddr, xfrm_address_t *daddr) 55 { 56 struct dst_entry *dst; 57 struct net_device *dev; 58 59 dst = xfrm6_dst_lookup(net, 0, NULL, daddr); 60 if (IS_ERR(dst)) 61 return -EHOSTUNREACH; 62 63 dev = ip6_dst_idev(dst)->dev; 64 ipv6_dev_get_saddr(dev_net(dev), dev, 65 (struct in6_addr *)&daddr->a6, 0, 66 (struct in6_addr *)&saddr->a6); 67 dst_release(dst); 68 return 0; 69 } 70 71 static int xfrm6_get_tos(const struct flowi *fl) 72 { 73 return 0; 74 } 75 76 static void xfrm6_init_dst(struct net *net, struct xfrm_dst *xdst) 77 { 78 struct rt6_info *rt = (struct rt6_info *)xdst; 79 80 rt6_init_peer(rt, net->ipv6.peers); 81 } 82 83 static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, 84 int nfheader_len) 85 { 86 if (dst->ops->family == AF_INET6) { 87 struct rt6_info *rt = (struct rt6_info *)dst; 88 if (rt->rt6i_node) 89 path->path_cookie = rt->rt6i_node->fn_sernum; 90 } 91 92 path->u.rt6.rt6i_nfheader_len = nfheader_len; 93 94 return 0; 95 } 96 97 static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, 98 const struct flowi *fl) 99 { 100 struct rt6_info *rt = (struct rt6_info *)xdst->route; 101 102 xdst->u.dst.dev = dev; 103 dev_hold(dev); 104 105 xdst->u.rt6.rt6i_idev = in6_dev_get(dev); 106 if (!xdst->u.rt6.rt6i_idev) { 107 dev_put(dev); 108 return -ENODEV; 109 } 110 111 rt6_transfer_peer(&xdst->u.rt6, rt); 112 113 /* Sheit... I remember I did this right. Apparently, 114 * it was magically lost, so this code needs audit */ 115 xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | 116 RTF_LOCAL); 117 xdst->u.rt6.rt6i_metric = rt->rt6i_metric; 118 xdst->u.rt6.rt6i_node = rt->rt6i_node; 119 if (rt->rt6i_node) 120 xdst->route_cookie = rt->rt6i_node->fn_sernum; 121 xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; 122 xdst->u.rt6.rt6i_dst = rt->rt6i_dst; 123 xdst->u.rt6.rt6i_src = rt->rt6i_src; 124 125 return 0; 126 } 127 128 static inline void 129 _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) 130 { 131 struct flowi6 *fl6 = &fl->u.ip6; 132 int onlyproto = 0; 133 u16 offset = skb_network_header_len(skb); 134 const struct ipv6hdr *hdr = ipv6_hdr(skb); 135 struct ipv6_opt_hdr *exthdr; 136 const unsigned char *nh = skb_network_header(skb); 137 u8 nexthdr = nh[IP6CB(skb)->nhoff]; 138 int oif = 0; 139 140 if (skb_dst(skb)) 141 oif = skb_dst(skb)->dev->ifindex; 142 143 memset(fl6, 0, sizeof(struct flowi6)); 144 fl6->flowi6_mark = skb->mark; 145 fl6->flowi6_oif = reverse ? skb->skb_iif : oif; 146 147 fl6->daddr = reverse ? hdr->saddr : hdr->daddr; 148 fl6->saddr = reverse ? hdr->daddr : hdr->saddr; 149 150 while (nh + offset + 1 < skb->data || 151 pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 152 nh = skb_network_header(skb); 153 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 154 155 switch (nexthdr) { 156 case NEXTHDR_FRAGMENT: 157 onlyproto = 1; 158 case NEXTHDR_ROUTING: 159 case NEXTHDR_HOP: 160 case NEXTHDR_DEST: 161 offset += ipv6_optlen(exthdr); 162 nexthdr = exthdr->nexthdr; 163 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 164 break; 165 166 case IPPROTO_UDP: 167 case IPPROTO_UDPLITE: 168 case IPPROTO_TCP: 169 case IPPROTO_SCTP: 170 case IPPROTO_DCCP: 171 if (!onlyproto && (nh + offset + 4 < skb->data || 172 pskb_may_pull(skb, nh + offset + 4 - skb->data))) { 173 __be16 *ports; 174 175 nh = skb_network_header(skb); 176 ports = (__be16 *)(nh + offset); 177 fl6->fl6_sport = ports[!!reverse]; 178 fl6->fl6_dport = ports[!reverse]; 179 } 180 fl6->flowi6_proto = nexthdr; 181 return; 182 183 case IPPROTO_ICMPV6: 184 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { 185 u8 *icmp; 186 187 nh = skb_network_header(skb); 188 icmp = (u8 *)(nh + offset); 189 fl6->fl6_icmp_type = icmp[0]; 190 fl6->fl6_icmp_code = icmp[1]; 191 } 192 fl6->flowi6_proto = nexthdr; 193 return; 194 195 #if IS_ENABLED(CONFIG_IPV6_MIP6) 196 case IPPROTO_MH: 197 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { 198 struct ip6_mh *mh; 199 200 nh = skb_network_header(skb); 201 mh = (struct ip6_mh *)(nh + offset); 202 fl6->fl6_mh_type = mh->ip6mh_type; 203 } 204 fl6->flowi6_proto = nexthdr; 205 return; 206 #endif 207 208 /* XXX Why are there these headers? */ 209 case IPPROTO_AH: 210 case IPPROTO_ESP: 211 case IPPROTO_COMP: 212 default: 213 fl6->fl6_ipsec_spi = 0; 214 fl6->flowi6_proto = nexthdr; 215 return; 216 } 217 } 218 } 219 220 static inline int xfrm6_garbage_collect(struct dst_ops *ops) 221 { 222 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); 223 224 xfrm6_policy_afinfo.garbage_collect(net); 225 return dst_entries_get_fast(ops) > ops->gc_thresh * 2; 226 } 227 228 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 229 struct sk_buff *skb, u32 mtu) 230 { 231 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 232 struct dst_entry *path = xdst->route; 233 234 path->ops->update_pmtu(path, sk, skb, mtu); 235 } 236 237 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 238 struct sk_buff *skb) 239 { 240 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 241 struct dst_entry *path = xdst->route; 242 243 path->ops->redirect(path, sk, skb); 244 } 245 246 static void xfrm6_dst_destroy(struct dst_entry *dst) 247 { 248 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 249 250 if (likely(xdst->u.rt6.rt6i_idev)) 251 in6_dev_put(xdst->u.rt6.rt6i_idev); 252 dst_destroy_metrics_generic(dst); 253 if (rt6_has_peer(&xdst->u.rt6)) { 254 struct inet_peer *peer = rt6_peer_ptr(&xdst->u.rt6); 255 inet_putpeer(peer); 256 } 257 xfrm_dst_destroy(xdst); 258 } 259 260 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 261 int unregister) 262 { 263 struct xfrm_dst *xdst; 264 265 if (!unregister) 266 return; 267 268 xdst = (struct xfrm_dst *)dst; 269 if (xdst->u.rt6.rt6i_idev->dev == dev) { 270 struct inet6_dev *loopback_idev = 271 in6_dev_get(dev_net(dev)->loopback_dev); 272 BUG_ON(!loopback_idev); 273 274 do { 275 in6_dev_put(xdst->u.rt6.rt6i_idev); 276 xdst->u.rt6.rt6i_idev = loopback_idev; 277 in6_dev_hold(loopback_idev); 278 xdst = (struct xfrm_dst *)xdst->u.dst.child; 279 } while (xdst->u.dst.xfrm); 280 281 __in6_dev_put(loopback_idev); 282 } 283 284 xfrm_dst_ifdown(dst, dev); 285 } 286 287 static struct dst_ops xfrm6_dst_ops = { 288 .family = AF_INET6, 289 .protocol = cpu_to_be16(ETH_P_IPV6), 290 .gc = xfrm6_garbage_collect, 291 .update_pmtu = xfrm6_update_pmtu, 292 .redirect = xfrm6_redirect, 293 .cow_metrics = dst_cow_metrics_generic, 294 .destroy = xfrm6_dst_destroy, 295 .ifdown = xfrm6_dst_ifdown, 296 .local_out = __ip6_local_out, 297 .gc_thresh = 32768, 298 }; 299 300 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 301 .family = AF_INET6, 302 .dst_ops = &xfrm6_dst_ops, 303 .dst_lookup = xfrm6_dst_lookup, 304 .get_saddr = xfrm6_get_saddr, 305 .decode_session = _decode_session6, 306 .get_tos = xfrm6_get_tos, 307 .init_dst = xfrm6_init_dst, 308 .init_path = xfrm6_init_path, 309 .fill_dst = xfrm6_fill_dst, 310 .blackhole_route = ip6_blackhole_route, 311 }; 312 313 static int __init xfrm6_policy_init(void) 314 { 315 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 316 } 317 318 static void xfrm6_policy_fini(void) 319 { 320 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 321 } 322 323 #ifdef CONFIG_SYSCTL 324 static struct ctl_table xfrm6_policy_table[] = { 325 { 326 .procname = "xfrm6_gc_thresh", 327 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 328 .maxlen = sizeof(int), 329 .mode = 0644, 330 .proc_handler = proc_dointvec, 331 }, 332 { } 333 }; 334 335 static int __net_init xfrm6_net_init(struct net *net) 336 { 337 struct ctl_table *table; 338 struct ctl_table_header *hdr; 339 340 table = xfrm6_policy_table; 341 if (!net_eq(net, &init_net)) { 342 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 343 if (!table) 344 goto err_alloc; 345 346 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 347 } 348 349 hdr = register_net_sysctl(net, "net/ipv6", table); 350 if (!hdr) 351 goto err_reg; 352 353 net->ipv6.sysctl.xfrm6_hdr = hdr; 354 return 0; 355 356 err_reg: 357 if (!net_eq(net, &init_net)) 358 kfree(table); 359 err_alloc: 360 return -ENOMEM; 361 } 362 363 static void __net_exit xfrm6_net_exit(struct net *net) 364 { 365 struct ctl_table *table; 366 367 if (net->ipv6.sysctl.xfrm6_hdr == NULL) 368 return; 369 370 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 371 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 372 if (!net_eq(net, &init_net)) 373 kfree(table); 374 } 375 376 static struct pernet_operations xfrm6_net_ops = { 377 .init = xfrm6_net_init, 378 .exit = xfrm6_net_exit, 379 }; 380 #endif 381 382 int __init xfrm6_init(void) 383 { 384 int ret; 385 386 dst_entries_init(&xfrm6_dst_ops); 387 388 ret = xfrm6_policy_init(); 389 if (ret) { 390 dst_entries_destroy(&xfrm6_dst_ops); 391 goto out; 392 } 393 ret = xfrm6_state_init(); 394 if (ret) 395 goto out_policy; 396 397 ret = xfrm6_protocol_init(); 398 if (ret) 399 goto out_state; 400 401 #ifdef CONFIG_SYSCTL 402 register_pernet_subsys(&xfrm6_net_ops); 403 #endif 404 out: 405 return ret; 406 out_state: 407 xfrm6_state_fini(); 408 out_policy: 409 xfrm6_policy_fini(); 410 goto out; 411 } 412 413 void xfrm6_fini(void) 414 { 415 #ifdef CONFIG_SYSCTL 416 unregister_pernet_subsys(&xfrm6_net_ops); 417 #endif 418 xfrm6_protocol_fini(); 419 xfrm6_policy_fini(); 420 xfrm6_state_fini(); 421 dst_entries_destroy(&xfrm6_dst_ops); 422 } 423