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]; 138 139 memset(fl6, 0, sizeof(struct flowi6)); 140 fl6->flowi6_mark = skb->mark; 141 142 fl6->daddr = reverse ? hdr->saddr : hdr->daddr; 143 fl6->saddr = reverse ? hdr->daddr : hdr->saddr; 144 145 while (nh + offset + 1 < skb->data || 146 pskb_may_pull(skb, nh + offset + 1 - skb->data)) { 147 nh = skb_network_header(skb); 148 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 149 150 switch (nexthdr) { 151 case NEXTHDR_FRAGMENT: 152 onlyproto = 1; 153 case NEXTHDR_ROUTING: 154 case NEXTHDR_HOP: 155 case NEXTHDR_DEST: 156 offset += ipv6_optlen(exthdr); 157 nexthdr = exthdr->nexthdr; 158 exthdr = (struct ipv6_opt_hdr *)(nh + offset); 159 break; 160 161 case IPPROTO_UDP: 162 case IPPROTO_UDPLITE: 163 case IPPROTO_TCP: 164 case IPPROTO_SCTP: 165 case IPPROTO_DCCP: 166 if (!onlyproto && (nh + offset + 4 < skb->data || 167 pskb_may_pull(skb, nh + offset + 4 - skb->data))) { 168 __be16 *ports = (__be16 *)exthdr; 169 170 fl6->fl6_sport = ports[!!reverse]; 171 fl6->fl6_dport = ports[!reverse]; 172 } 173 fl6->flowi6_proto = nexthdr; 174 return; 175 176 case IPPROTO_ICMPV6: 177 if (!onlyproto && pskb_may_pull(skb, nh + offset + 2 - skb->data)) { 178 u8 *icmp = (u8 *)exthdr; 179 180 fl6->fl6_icmp_type = icmp[0]; 181 fl6->fl6_icmp_code = icmp[1]; 182 } 183 fl6->flowi6_proto = nexthdr; 184 return; 185 186 #if IS_ENABLED(CONFIG_IPV6_MIP6) 187 case IPPROTO_MH: 188 if (!onlyproto && pskb_may_pull(skb, nh + offset + 3 - skb->data)) { 189 struct ip6_mh *mh; 190 mh = (struct ip6_mh *)exthdr; 191 192 fl6->fl6_mh_type = mh->ip6mh_type; 193 } 194 fl6->flowi6_proto = nexthdr; 195 return; 196 #endif 197 198 /* XXX Why are there these headers? */ 199 case IPPROTO_AH: 200 case IPPROTO_ESP: 201 case IPPROTO_COMP: 202 default: 203 fl6->fl6_ipsec_spi = 0; 204 fl6->flowi6_proto = nexthdr; 205 return; 206 } 207 } 208 } 209 210 static inline int xfrm6_garbage_collect(struct dst_ops *ops) 211 { 212 struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); 213 214 xfrm6_policy_afinfo.garbage_collect(net); 215 return dst_entries_get_fast(ops) > ops->gc_thresh * 2; 216 } 217 218 static void xfrm6_update_pmtu(struct dst_entry *dst, struct sock *sk, 219 struct sk_buff *skb, u32 mtu) 220 { 221 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 222 struct dst_entry *path = xdst->route; 223 224 path->ops->update_pmtu(path, sk, skb, mtu); 225 } 226 227 static void xfrm6_redirect(struct dst_entry *dst, struct sock *sk, 228 struct sk_buff *skb) 229 { 230 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 231 struct dst_entry *path = xdst->route; 232 233 path->ops->redirect(path, sk, skb); 234 } 235 236 static void xfrm6_dst_destroy(struct dst_entry *dst) 237 { 238 struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 239 240 if (likely(xdst->u.rt6.rt6i_idev)) 241 in6_dev_put(xdst->u.rt6.rt6i_idev); 242 dst_destroy_metrics_generic(dst); 243 if (rt6_has_peer(&xdst->u.rt6)) { 244 struct inet_peer *peer = rt6_peer_ptr(&xdst->u.rt6); 245 inet_putpeer(peer); 246 } 247 xfrm_dst_destroy(xdst); 248 } 249 250 static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 251 int unregister) 252 { 253 struct xfrm_dst *xdst; 254 255 if (!unregister) 256 return; 257 258 xdst = (struct xfrm_dst *)dst; 259 if (xdst->u.rt6.rt6i_idev->dev == dev) { 260 struct inet6_dev *loopback_idev = 261 in6_dev_get(dev_net(dev)->loopback_dev); 262 BUG_ON(!loopback_idev); 263 264 do { 265 in6_dev_put(xdst->u.rt6.rt6i_idev); 266 xdst->u.rt6.rt6i_idev = loopback_idev; 267 in6_dev_hold(loopback_idev); 268 xdst = (struct xfrm_dst *)xdst->u.dst.child; 269 } while (xdst->u.dst.xfrm); 270 271 __in6_dev_put(loopback_idev); 272 } 273 274 xfrm_dst_ifdown(dst, dev); 275 } 276 277 static struct dst_ops xfrm6_dst_ops = { 278 .family = AF_INET6, 279 .protocol = cpu_to_be16(ETH_P_IPV6), 280 .gc = xfrm6_garbage_collect, 281 .update_pmtu = xfrm6_update_pmtu, 282 .redirect = xfrm6_redirect, 283 .cow_metrics = dst_cow_metrics_generic, 284 .destroy = xfrm6_dst_destroy, 285 .ifdown = xfrm6_dst_ifdown, 286 .local_out = __ip6_local_out, 287 .gc_thresh = 1024, 288 }; 289 290 static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { 291 .family = AF_INET6, 292 .dst_ops = &xfrm6_dst_ops, 293 .dst_lookup = xfrm6_dst_lookup, 294 .get_saddr = xfrm6_get_saddr, 295 .decode_session = _decode_session6, 296 .get_tos = xfrm6_get_tos, 297 .init_dst = xfrm6_init_dst, 298 .init_path = xfrm6_init_path, 299 .fill_dst = xfrm6_fill_dst, 300 .blackhole_route = ip6_blackhole_route, 301 }; 302 303 static int __init xfrm6_policy_init(void) 304 { 305 return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); 306 } 307 308 static void xfrm6_policy_fini(void) 309 { 310 xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); 311 } 312 313 #ifdef CONFIG_SYSCTL 314 static struct ctl_table xfrm6_policy_table[] = { 315 { 316 .procname = "xfrm6_gc_thresh", 317 .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, 318 .maxlen = sizeof(int), 319 .mode = 0644, 320 .proc_handler = proc_dointvec, 321 }, 322 { } 323 }; 324 325 static int __net_init xfrm6_net_init(struct net *net) 326 { 327 struct ctl_table *table; 328 struct ctl_table_header *hdr; 329 330 table = xfrm6_policy_table; 331 if (!net_eq(net, &init_net)) { 332 table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); 333 if (!table) 334 goto err_alloc; 335 336 table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; 337 } 338 339 hdr = register_net_sysctl(net, "net/ipv6", table); 340 if (!hdr) 341 goto err_reg; 342 343 net->ipv6.sysctl.xfrm6_hdr = hdr; 344 return 0; 345 346 err_reg: 347 if (!net_eq(net, &init_net)) 348 kfree(table); 349 err_alloc: 350 return -ENOMEM; 351 } 352 353 static void __net_exit xfrm6_net_exit(struct net *net) 354 { 355 struct ctl_table *table; 356 357 if (net->ipv6.sysctl.xfrm6_hdr == NULL) 358 return; 359 360 table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; 361 unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); 362 if (!net_eq(net, &init_net)) 363 kfree(table); 364 } 365 366 static struct pernet_operations xfrm6_net_ops = { 367 .init = xfrm6_net_init, 368 .exit = xfrm6_net_exit, 369 }; 370 #endif 371 372 int __init xfrm6_init(void) 373 { 374 int ret; 375 376 dst_entries_init(&xfrm6_dst_ops); 377 378 ret = xfrm6_policy_init(); 379 if (ret) { 380 dst_entries_destroy(&xfrm6_dst_ops); 381 goto out; 382 } 383 ret = xfrm6_state_init(); 384 if (ret) 385 goto out_policy; 386 387 #ifdef CONFIG_SYSCTL 388 register_pernet_subsys(&xfrm6_net_ops); 389 #endif 390 out: 391 return ret; 392 out_policy: 393 xfrm6_policy_fini(); 394 goto out; 395 } 396 397 void xfrm6_fini(void) 398 { 399 #ifdef CONFIG_SYSCTL 400 unregister_pernet_subsys(&xfrm6_net_ops); 401 #endif 402 xfrm6_policy_fini(); 403 xfrm6_state_fini(); 404 dst_entries_destroy(&xfrm6_dst_ops); 405 } 406