1 /* 2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT) 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 * 14 * Changes: 15 * Roger Venning <r.venning@telstra.com>: 6to4 support 16 * Nate Thompson <nate@thebog.net>: 6to4 support 17 * Fred Templin <fred.l.templin@boeing.com>: isatap support 18 */ 19 20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 21 22 #include <linux/module.h> 23 #include <linux/capability.h> 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/net.h> 29 #include <linux/in6.h> 30 #include <linux/netdevice.h> 31 #include <linux/if_arp.h> 32 #include <linux/icmp.h> 33 #include <linux/slab.h> 34 #include <linux/uaccess.h> 35 #include <linux/init.h> 36 #include <linux/netfilter_ipv4.h> 37 #include <linux/if_ether.h> 38 39 #include <net/sock.h> 40 #include <net/snmp.h> 41 42 #include <net/ipv6.h> 43 #include <net/protocol.h> 44 #include <net/transp_v6.h> 45 #include <net/ip6_fib.h> 46 #include <net/ip6_route.h> 47 #include <net/ndisc.h> 48 #include <net/addrconf.h> 49 #include <net/ip.h> 50 #include <net/udp.h> 51 #include <net/icmp.h> 52 #include <net/ip_tunnels.h> 53 #include <net/inet_ecn.h> 54 #include <net/xfrm.h> 55 #include <net/dsfield.h> 56 #include <net/net_namespace.h> 57 #include <net/netns/generic.h> 58 59 /* 60 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 61 62 For comments look at net/ipv4/ip_gre.c --ANK 63 */ 64 65 #define IP6_SIT_HASH_SIZE 16 66 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 67 68 static bool log_ecn_error = true; 69 module_param(log_ecn_error, bool, 0644); 70 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 71 72 static int ipip6_tunnel_init(struct net_device *dev); 73 static void ipip6_tunnel_setup(struct net_device *dev); 74 static void ipip6_dev_free(struct net_device *dev); 75 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 76 __be32 *v4dst); 77 static struct rtnl_link_ops sit_link_ops __read_mostly; 78 79 static unsigned int sit_net_id __read_mostly; 80 struct sit_net { 81 struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE]; 82 struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE]; 83 struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE]; 84 struct ip_tunnel __rcu *tunnels_wc[1]; 85 struct ip_tunnel __rcu **tunnels[4]; 86 87 struct net_device *fb_tunnel_dev; 88 }; 89 90 /* 91 * Must be invoked with rcu_read_lock 92 */ 93 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net, 94 struct net_device *dev, 95 __be32 remote, __be32 local, 96 int sifindex) 97 { 98 unsigned int h0 = HASH(remote); 99 unsigned int h1 = HASH(local); 100 struct ip_tunnel *t; 101 struct sit_net *sitn = net_generic(net, sit_net_id); 102 int ifindex = dev ? dev->ifindex : 0; 103 104 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) { 105 if (local == t->parms.iph.saddr && 106 remote == t->parms.iph.daddr && 107 (!dev || !t->parms.link || ifindex == t->parms.link || 108 sifindex == t->parms.link) && 109 (t->dev->flags & IFF_UP)) 110 return t; 111 } 112 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) { 113 if (remote == t->parms.iph.daddr && 114 (!dev || !t->parms.link || ifindex == t->parms.link || 115 sifindex == t->parms.link) && 116 (t->dev->flags & IFF_UP)) 117 return t; 118 } 119 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) { 120 if (local == t->parms.iph.saddr && 121 (!dev || !t->parms.link || ifindex == t->parms.link || 122 sifindex == t->parms.link) && 123 (t->dev->flags & IFF_UP)) 124 return t; 125 } 126 t = rcu_dereference(sitn->tunnels_wc[0]); 127 if (t && (t->dev->flags & IFF_UP)) 128 return t; 129 return NULL; 130 } 131 132 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn, 133 struct ip_tunnel_parm *parms) 134 { 135 __be32 remote = parms->iph.daddr; 136 __be32 local = parms->iph.saddr; 137 unsigned int h = 0; 138 int prio = 0; 139 140 if (remote) { 141 prio |= 2; 142 h ^= HASH(remote); 143 } 144 if (local) { 145 prio |= 1; 146 h ^= HASH(local); 147 } 148 return &sitn->tunnels[prio][h]; 149 } 150 151 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn, 152 struct ip_tunnel *t) 153 { 154 return __ipip6_bucket(sitn, &t->parms); 155 } 156 157 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 158 { 159 struct ip_tunnel __rcu **tp; 160 struct ip_tunnel *iter; 161 162 for (tp = ipip6_bucket(sitn, t); 163 (iter = rtnl_dereference(*tp)) != NULL; 164 tp = &iter->next) { 165 if (t == iter) { 166 rcu_assign_pointer(*tp, t->next); 167 break; 168 } 169 } 170 } 171 172 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 173 { 174 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t); 175 176 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 177 rcu_assign_pointer(*tp, t); 178 } 179 180 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 181 { 182 #ifdef CONFIG_IPV6_SIT_6RD 183 struct ip_tunnel *t = netdev_priv(dev); 184 185 if (t->dev == sitn->fb_tunnel_dev) { 186 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 187 t->ip6rd.relay_prefix = 0; 188 t->ip6rd.prefixlen = 16; 189 t->ip6rd.relay_prefixlen = 0; 190 } else { 191 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 192 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 193 } 194 #endif 195 } 196 197 static int ipip6_tunnel_create(struct net_device *dev) 198 { 199 struct ip_tunnel *t = netdev_priv(dev); 200 struct net *net = dev_net(dev); 201 struct sit_net *sitn = net_generic(net, sit_net_id); 202 int err; 203 204 memcpy(dev->dev_addr, &t->parms.iph.saddr, 4); 205 memcpy(dev->broadcast, &t->parms.iph.daddr, 4); 206 207 if ((__force u16)t->parms.i_flags & SIT_ISATAP) 208 dev->priv_flags |= IFF_ISATAP; 209 210 dev->rtnl_link_ops = &sit_link_ops; 211 212 err = register_netdevice(dev); 213 if (err < 0) 214 goto out; 215 216 ipip6_tunnel_clone_6rd(dev, sitn); 217 218 dev_hold(dev); 219 220 ipip6_tunnel_link(sitn, t); 221 return 0; 222 223 out: 224 return err; 225 } 226 227 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, 228 struct ip_tunnel_parm *parms, int create) 229 { 230 __be32 remote = parms->iph.daddr; 231 __be32 local = parms->iph.saddr; 232 struct ip_tunnel *t, *nt; 233 struct ip_tunnel __rcu **tp; 234 struct net_device *dev; 235 char name[IFNAMSIZ]; 236 struct sit_net *sitn = net_generic(net, sit_net_id); 237 238 for (tp = __ipip6_bucket(sitn, parms); 239 (t = rtnl_dereference(*tp)) != NULL; 240 tp = &t->next) { 241 if (local == t->parms.iph.saddr && 242 remote == t->parms.iph.daddr && 243 parms->link == t->parms.link) { 244 if (create) 245 return NULL; 246 else 247 return t; 248 } 249 } 250 if (!create) 251 goto failed; 252 253 if (parms->name[0]) 254 strlcpy(name, parms->name, IFNAMSIZ); 255 else 256 strcpy(name, "sit%d"); 257 258 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, 259 ipip6_tunnel_setup); 260 if (!dev) 261 return NULL; 262 263 dev_net_set(dev, net); 264 265 nt = netdev_priv(dev); 266 267 nt->parms = *parms; 268 if (ipip6_tunnel_create(dev) < 0) 269 goto failed_free; 270 271 return nt; 272 273 failed_free: 274 free_netdev(dev); 275 failed: 276 return NULL; 277 } 278 279 #define for_each_prl_rcu(start) \ 280 for (prl = rcu_dereference(start); \ 281 prl; \ 282 prl = rcu_dereference(prl->next)) 283 284 static struct ip_tunnel_prl_entry * 285 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 286 { 287 struct ip_tunnel_prl_entry *prl; 288 289 for_each_prl_rcu(t->prl) 290 if (prl->addr == addr) 291 break; 292 return prl; 293 294 } 295 296 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 297 struct ip_tunnel_prl __user *a) 298 { 299 struct ip_tunnel_prl kprl, *kp; 300 struct ip_tunnel_prl_entry *prl; 301 unsigned int cmax, c = 0, ca, len; 302 int ret = 0; 303 304 if (copy_from_user(&kprl, a, sizeof(kprl))) 305 return -EFAULT; 306 cmax = kprl.datalen / sizeof(kprl); 307 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 308 cmax = 1; 309 310 /* For simple GET or for root users, 311 * we try harder to allocate. 312 */ 313 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 314 kcalloc(cmax, sizeof(*kp), GFP_KERNEL | __GFP_NOWARN) : 315 NULL; 316 317 rcu_read_lock(); 318 319 ca = t->prl_count < cmax ? t->prl_count : cmax; 320 321 if (!kp) { 322 /* We don't try hard to allocate much memory for 323 * non-root users. 324 * For root users, retry allocating enough memory for 325 * the answer. 326 */ 327 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 328 if (!kp) { 329 ret = -ENOMEM; 330 goto out; 331 } 332 } 333 334 c = 0; 335 for_each_prl_rcu(t->prl) { 336 if (c >= cmax) 337 break; 338 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 339 continue; 340 kp[c].addr = prl->addr; 341 kp[c].flags = prl->flags; 342 c++; 343 if (kprl.addr != htonl(INADDR_ANY)) 344 break; 345 } 346 out: 347 rcu_read_unlock(); 348 349 len = sizeof(*kp) * c; 350 ret = 0; 351 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 352 ret = -EFAULT; 353 354 kfree(kp); 355 356 return ret; 357 } 358 359 static int 360 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 361 { 362 struct ip_tunnel_prl_entry *p; 363 int err = 0; 364 365 if (a->addr == htonl(INADDR_ANY)) 366 return -EINVAL; 367 368 ASSERT_RTNL(); 369 370 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) { 371 if (p->addr == a->addr) { 372 if (chg) { 373 p->flags = a->flags; 374 goto out; 375 } 376 err = -EEXIST; 377 goto out; 378 } 379 } 380 381 if (chg) { 382 err = -ENXIO; 383 goto out; 384 } 385 386 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 387 if (!p) { 388 err = -ENOBUFS; 389 goto out; 390 } 391 392 p->next = t->prl; 393 p->addr = a->addr; 394 p->flags = a->flags; 395 t->prl_count++; 396 rcu_assign_pointer(t->prl, p); 397 out: 398 return err; 399 } 400 401 static void prl_list_destroy_rcu(struct rcu_head *head) 402 { 403 struct ip_tunnel_prl_entry *p, *n; 404 405 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 406 do { 407 n = rcu_dereference_protected(p->next, 1); 408 kfree(p); 409 p = n; 410 } while (p); 411 } 412 413 static int 414 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 415 { 416 struct ip_tunnel_prl_entry *x; 417 struct ip_tunnel_prl_entry __rcu **p; 418 int err = 0; 419 420 ASSERT_RTNL(); 421 422 if (a && a->addr != htonl(INADDR_ANY)) { 423 for (p = &t->prl; 424 (x = rtnl_dereference(*p)) != NULL; 425 p = &x->next) { 426 if (x->addr == a->addr) { 427 *p = x->next; 428 kfree_rcu(x, rcu_head); 429 t->prl_count--; 430 goto out; 431 } 432 } 433 err = -ENXIO; 434 } else { 435 x = rtnl_dereference(t->prl); 436 if (x) { 437 t->prl_count = 0; 438 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 439 t->prl = NULL; 440 } 441 } 442 out: 443 return err; 444 } 445 446 static int 447 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t) 448 { 449 struct ip_tunnel_prl_entry *p; 450 int ok = 1; 451 452 rcu_read_lock(); 453 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 454 if (p) { 455 if (p->flags & PRL_DEFAULT) 456 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 457 else 458 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 459 } else { 460 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 461 462 if (ipv6_addr_is_isatap(addr6) && 463 (addr6->s6_addr32[3] == iph->saddr) && 464 ipv6_chk_prefix(addr6, t->dev)) 465 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 466 else 467 ok = 0; 468 } 469 rcu_read_unlock(); 470 return ok; 471 } 472 473 static void ipip6_tunnel_uninit(struct net_device *dev) 474 { 475 struct ip_tunnel *tunnel = netdev_priv(dev); 476 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id); 477 478 if (dev == sitn->fb_tunnel_dev) { 479 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL); 480 } else { 481 ipip6_tunnel_unlink(sitn, tunnel); 482 ipip6_tunnel_del_prl(tunnel, NULL); 483 } 484 dst_cache_reset(&tunnel->dst_cache); 485 dev_put(dev); 486 } 487 488 static int ipip6_err(struct sk_buff *skb, u32 info) 489 { 490 const struct iphdr *iph = (const struct iphdr *)skb->data; 491 const int type = icmp_hdr(skb)->type; 492 const int code = icmp_hdr(skb)->code; 493 unsigned int data_len = 0; 494 struct ip_tunnel *t; 495 int sifindex; 496 int err; 497 498 switch (type) { 499 default: 500 case ICMP_PARAMETERPROB: 501 return 0; 502 503 case ICMP_DEST_UNREACH: 504 switch (code) { 505 case ICMP_SR_FAILED: 506 /* Impossible event. */ 507 return 0; 508 default: 509 /* All others are translated to HOST_UNREACH. 510 rfc2003 contains "deep thoughts" about NET_UNREACH, 511 I believe they are just ether pollution. --ANK 512 */ 513 break; 514 } 515 break; 516 case ICMP_TIME_EXCEEDED: 517 if (code != ICMP_EXC_TTL) 518 return 0; 519 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 520 break; 521 case ICMP_REDIRECT: 522 break; 523 } 524 525 err = -ENOENT; 526 527 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; 528 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 529 iph->daddr, iph->saddr, sifindex); 530 if (!t) 531 goto out; 532 533 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 534 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 535 t->parms.link, 0, iph->protocol, 0); 536 err = 0; 537 goto out; 538 } 539 if (type == ICMP_REDIRECT) { 540 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0, 541 iph->protocol, 0); 542 err = 0; 543 goto out; 544 } 545 546 err = 0; 547 if (!ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len)) 548 goto out; 549 550 if (t->parms.iph.daddr == 0) 551 goto out; 552 553 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 554 goto out; 555 556 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 557 t->err_count++; 558 else 559 t->err_count = 1; 560 t->err_time = jiffies; 561 out: 562 return err; 563 } 564 565 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, 566 const struct in6_addr *v6addr) 567 { 568 __be32 v4embed = 0; 569 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) 570 return true; 571 return false; 572 } 573 574 /* Checks if an address matches an address on the tunnel interface. 575 * Used to detect the NAT of proto 41 packets and let them pass spoofing test. 576 * Long story: 577 * This function is called after we considered the packet as spoofed 578 * in is_spoofed_6rd. 579 * We may have a router that is doing NAT for proto 41 packets 580 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb 581 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd 582 * function will return true, dropping the packet. 583 * But, we can still check if is spoofed against the IP 584 * addresses associated with the interface. 585 */ 586 static bool only_dnatted(const struct ip_tunnel *tunnel, 587 const struct in6_addr *v6dst) 588 { 589 int prefix_len; 590 591 #ifdef CONFIG_IPV6_SIT_6RD 592 prefix_len = tunnel->ip6rd.prefixlen + 32 593 - tunnel->ip6rd.relay_prefixlen; 594 #else 595 prefix_len = 48; 596 #endif 597 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev); 598 } 599 600 /* Returns true if a packet is spoofed */ 601 static bool packet_is_spoofed(struct sk_buff *skb, 602 const struct iphdr *iph, 603 struct ip_tunnel *tunnel) 604 { 605 const struct ipv6hdr *ipv6h; 606 607 if (tunnel->dev->priv_flags & IFF_ISATAP) { 608 if (!isatap_chksrc(skb, iph, tunnel)) 609 return true; 610 611 return false; 612 } 613 614 if (tunnel->dev->flags & IFF_POINTOPOINT) 615 return false; 616 617 ipv6h = ipv6_hdr(skb); 618 619 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) { 620 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 621 &iph->saddr, &ipv6h->saddr, 622 &iph->daddr, &ipv6h->daddr); 623 return true; 624 } 625 626 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr))) 627 return false; 628 629 if (only_dnatted(tunnel, &ipv6h->daddr)) 630 return false; 631 632 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 633 &iph->saddr, &ipv6h->saddr, 634 &iph->daddr, &ipv6h->daddr); 635 return true; 636 } 637 638 static int ipip6_rcv(struct sk_buff *skb) 639 { 640 const struct iphdr *iph = ip_hdr(skb); 641 struct ip_tunnel *tunnel; 642 int sifindex; 643 int err; 644 645 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; 646 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 647 iph->saddr, iph->daddr, sifindex); 648 if (tunnel) { 649 struct pcpu_sw_netstats *tstats; 650 651 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && 652 tunnel->parms.iph.protocol != 0) 653 goto out; 654 655 skb->mac_header = skb->network_header; 656 skb_reset_network_header(skb); 657 IPCB(skb)->flags = 0; 658 skb->dev = tunnel->dev; 659 660 if (packet_is_spoofed(skb, iph, tunnel)) { 661 tunnel->dev->stats.rx_errors++; 662 goto out; 663 } 664 665 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6), 666 !net_eq(tunnel->net, dev_net(tunnel->dev)))) 667 goto out; 668 669 err = IP_ECN_decapsulate(iph, skb); 670 if (unlikely(err)) { 671 if (log_ecn_error) 672 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 673 &iph->saddr, iph->tos); 674 if (err > 1) { 675 ++tunnel->dev->stats.rx_frame_errors; 676 ++tunnel->dev->stats.rx_errors; 677 goto out; 678 } 679 } 680 681 tstats = this_cpu_ptr(tunnel->dev->tstats); 682 u64_stats_update_begin(&tstats->syncp); 683 tstats->rx_packets++; 684 tstats->rx_bytes += skb->len; 685 u64_stats_update_end(&tstats->syncp); 686 687 netif_rx(skb); 688 689 return 0; 690 } 691 692 /* no tunnel matched, let upstream know, ipsec may handle it */ 693 return 1; 694 out: 695 kfree_skb(skb); 696 return 0; 697 } 698 699 static const struct tnl_ptk_info ipip_tpi = { 700 /* no tunnel info required for ipip. */ 701 .proto = htons(ETH_P_IP), 702 }; 703 704 #if IS_ENABLED(CONFIG_MPLS) 705 static const struct tnl_ptk_info mplsip_tpi = { 706 /* no tunnel info required for mplsip. */ 707 .proto = htons(ETH_P_MPLS_UC), 708 }; 709 #endif 710 711 static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto) 712 { 713 const struct iphdr *iph; 714 struct ip_tunnel *tunnel; 715 int sifindex; 716 717 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; 718 719 iph = ip_hdr(skb); 720 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 721 iph->saddr, iph->daddr, sifindex); 722 if (tunnel) { 723 const struct tnl_ptk_info *tpi; 724 725 if (tunnel->parms.iph.protocol != ipproto && 726 tunnel->parms.iph.protocol != 0) 727 goto drop; 728 729 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 730 goto drop; 731 #if IS_ENABLED(CONFIG_MPLS) 732 if (ipproto == IPPROTO_MPLS) 733 tpi = &mplsip_tpi; 734 else 735 #endif 736 tpi = &ipip_tpi; 737 if (iptunnel_pull_header(skb, 0, tpi->proto, false)) 738 goto drop; 739 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error); 740 } 741 742 return 1; 743 744 drop: 745 kfree_skb(skb); 746 return 0; 747 } 748 749 static int ipip_rcv(struct sk_buff *skb) 750 { 751 return sit_tunnel_rcv(skb, IPPROTO_IPIP); 752 } 753 754 #if IS_ENABLED(CONFIG_MPLS) 755 static int mplsip_rcv(struct sk_buff *skb) 756 { 757 return sit_tunnel_rcv(skb, IPPROTO_MPLS); 758 } 759 #endif 760 761 /* 762 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function 763 * stores the embedded IPv4 address in v4dst and returns true. 764 */ 765 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 766 __be32 *v4dst) 767 { 768 #ifdef CONFIG_IPV6_SIT_6RD 769 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 770 tunnel->ip6rd.prefixlen)) { 771 unsigned int pbw0, pbi0; 772 int pbi1; 773 u32 d; 774 775 pbw0 = tunnel->ip6rd.prefixlen >> 5; 776 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 777 778 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 779 tunnel->ip6rd.relay_prefixlen; 780 781 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 782 if (pbi1 > 0) 783 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 784 (32 - pbi1); 785 786 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); 787 return true; 788 } 789 #else 790 if (v6dst->s6_addr16[0] == htons(0x2002)) { 791 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 792 memcpy(v4dst, &v6dst->s6_addr16[1], 4); 793 return true; 794 } 795 #endif 796 return false; 797 } 798 799 static inline __be32 try_6rd(struct ip_tunnel *tunnel, 800 const struct in6_addr *v6dst) 801 { 802 __be32 dst = 0; 803 check_6rd(tunnel, v6dst, &dst); 804 return dst; 805 } 806 807 /* 808 * This function assumes it is being called from dev_queue_xmit() 809 * and that skb is filled properly by that function. 810 */ 811 812 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 813 struct net_device *dev) 814 { 815 struct ip_tunnel *tunnel = netdev_priv(dev); 816 const struct iphdr *tiph = &tunnel->parms.iph; 817 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 818 u8 tos = tunnel->parms.iph.tos; 819 __be16 df = tiph->frag_off; 820 struct rtable *rt; /* Route to the other host */ 821 struct net_device *tdev; /* Device to other host */ 822 unsigned int max_headroom; /* The extra header space needed */ 823 __be32 dst = tiph->daddr; 824 struct flowi4 fl4; 825 int mtu; 826 const struct in6_addr *addr6; 827 int addr_type; 828 u8 ttl; 829 u8 protocol = IPPROTO_IPV6; 830 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 831 832 if (tos == 1) 833 tos = ipv6_get_dsfield(iph6); 834 835 /* ISATAP (RFC4214) - must come before 6to4 */ 836 if (dev->priv_flags & IFF_ISATAP) { 837 struct neighbour *neigh = NULL; 838 bool do_tx_error = false; 839 840 if (skb_dst(skb)) 841 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 842 843 if (!neigh) { 844 net_dbg_ratelimited("nexthop == NULL\n"); 845 goto tx_error; 846 } 847 848 addr6 = (const struct in6_addr *)&neigh->primary_key; 849 addr_type = ipv6_addr_type(addr6); 850 851 if ((addr_type & IPV6_ADDR_UNICAST) && 852 ipv6_addr_is_isatap(addr6)) 853 dst = addr6->s6_addr32[3]; 854 else 855 do_tx_error = true; 856 857 neigh_release(neigh); 858 if (do_tx_error) 859 goto tx_error; 860 } 861 862 if (!dst) 863 dst = try_6rd(tunnel, &iph6->daddr); 864 865 if (!dst) { 866 struct neighbour *neigh = NULL; 867 bool do_tx_error = false; 868 869 if (skb_dst(skb)) 870 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 871 872 if (!neigh) { 873 net_dbg_ratelimited("nexthop == NULL\n"); 874 goto tx_error; 875 } 876 877 addr6 = (const struct in6_addr *)&neigh->primary_key; 878 addr_type = ipv6_addr_type(addr6); 879 880 if (addr_type == IPV6_ADDR_ANY) { 881 addr6 = &ipv6_hdr(skb)->daddr; 882 addr_type = ipv6_addr_type(addr6); 883 } 884 885 if ((addr_type & IPV6_ADDR_COMPATv4) != 0) 886 dst = addr6->s6_addr32[3]; 887 else 888 do_tx_error = true; 889 890 neigh_release(neigh); 891 if (do_tx_error) 892 goto tx_error; 893 } 894 895 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark, 896 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6, 897 0, dst, tiph->saddr, 0, 0, 898 sock_net_uid(tunnel->net, NULL)); 899 rt = ip_route_output_flow(tunnel->net, &fl4, NULL); 900 901 if (IS_ERR(rt)) { 902 dev->stats.tx_carrier_errors++; 903 goto tx_error_icmp; 904 } 905 if (rt->rt_type != RTN_UNICAST) { 906 ip_rt_put(rt); 907 dev->stats.tx_carrier_errors++; 908 goto tx_error_icmp; 909 } 910 tdev = rt->dst.dev; 911 912 if (tdev == dev) { 913 ip_rt_put(rt); 914 dev->stats.collisions++; 915 goto tx_error; 916 } 917 918 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) { 919 ip_rt_put(rt); 920 goto tx_error; 921 } 922 923 if (df) { 924 mtu = dst_mtu(&rt->dst) - t_hlen; 925 926 if (mtu < 68) { 927 dev->stats.collisions++; 928 ip_rt_put(rt); 929 goto tx_error; 930 } 931 932 if (mtu < IPV6_MIN_MTU) { 933 mtu = IPV6_MIN_MTU; 934 df = 0; 935 } 936 937 if (tunnel->parms.iph.daddr) 938 skb_dst_update_pmtu(skb, mtu); 939 940 if (skb->len > mtu && !skb_is_gso(skb)) { 941 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 942 ip_rt_put(rt); 943 goto tx_error; 944 } 945 } 946 947 if (tunnel->err_count > 0) { 948 if (time_before(jiffies, 949 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 950 tunnel->err_count--; 951 dst_link_failure(skb); 952 } else 953 tunnel->err_count = 0; 954 } 955 956 /* 957 * Okay, now see if we can stuff it in the buffer as-is. 958 */ 959 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen; 960 961 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 962 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 963 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 964 if (!new_skb) { 965 ip_rt_put(rt); 966 dev->stats.tx_dropped++; 967 kfree_skb(skb); 968 return NETDEV_TX_OK; 969 } 970 if (skb->sk) 971 skb_set_owner_w(new_skb, skb->sk); 972 dev_kfree_skb(skb); 973 skb = new_skb; 974 iph6 = ipv6_hdr(skb); 975 } 976 ttl = tiph->ttl; 977 if (ttl == 0) 978 ttl = iph6->hop_limit; 979 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 980 981 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) { 982 ip_rt_put(rt); 983 goto tx_error; 984 } 985 986 skb_set_inner_ipproto(skb, IPPROTO_IPV6); 987 988 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, 989 df, !net_eq(tunnel->net, dev_net(dev))); 990 return NETDEV_TX_OK; 991 992 tx_error_icmp: 993 dst_link_failure(skb); 994 tx_error: 995 kfree_skb(skb); 996 dev->stats.tx_errors++; 997 return NETDEV_TX_OK; 998 } 999 1000 static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb, 1001 struct net_device *dev, u8 ipproto) 1002 { 1003 struct ip_tunnel *tunnel = netdev_priv(dev); 1004 const struct iphdr *tiph = &tunnel->parms.iph; 1005 1006 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) 1007 goto tx_error; 1008 1009 skb_set_inner_ipproto(skb, ipproto); 1010 1011 ip_tunnel_xmit(skb, dev, tiph, ipproto); 1012 return NETDEV_TX_OK; 1013 tx_error: 1014 kfree_skb(skb); 1015 dev->stats.tx_errors++; 1016 return NETDEV_TX_OK; 1017 } 1018 1019 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, 1020 struct net_device *dev) 1021 { 1022 switch (skb->protocol) { 1023 case htons(ETH_P_IP): 1024 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP); 1025 break; 1026 case htons(ETH_P_IPV6): 1027 ipip6_tunnel_xmit(skb, dev); 1028 break; 1029 #if IS_ENABLED(CONFIG_MPLS) 1030 case htons(ETH_P_MPLS_UC): 1031 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS); 1032 break; 1033 #endif 1034 default: 1035 goto tx_err; 1036 } 1037 1038 return NETDEV_TX_OK; 1039 1040 tx_err: 1041 dev->stats.tx_errors++; 1042 kfree_skb(skb); 1043 return NETDEV_TX_OK; 1044 1045 } 1046 1047 static void ipip6_tunnel_bind_dev(struct net_device *dev) 1048 { 1049 struct net_device *tdev = NULL; 1050 struct ip_tunnel *tunnel; 1051 const struct iphdr *iph; 1052 struct flowi4 fl4; 1053 1054 tunnel = netdev_priv(dev); 1055 iph = &tunnel->parms.iph; 1056 1057 if (iph->daddr) { 1058 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, 1059 NULL, 1060 iph->daddr, iph->saddr, 1061 0, 0, 1062 IPPROTO_IPV6, 1063 RT_TOS(iph->tos), 1064 tunnel->parms.link); 1065 1066 if (!IS_ERR(rt)) { 1067 tdev = rt->dst.dev; 1068 ip_rt_put(rt); 1069 } 1070 dev->flags |= IFF_POINTOPOINT; 1071 } 1072 1073 if (!tdev && tunnel->parms.link) 1074 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 1075 1076 if (tdev) { 1077 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 1078 1079 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 1080 dev->mtu = tdev->mtu - t_hlen; 1081 if (dev->mtu < IPV6_MIN_MTU) 1082 dev->mtu = IPV6_MIN_MTU; 1083 } 1084 } 1085 1086 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p, 1087 __u32 fwmark) 1088 { 1089 struct net *net = t->net; 1090 struct sit_net *sitn = net_generic(net, sit_net_id); 1091 1092 ipip6_tunnel_unlink(sitn, t); 1093 synchronize_net(); 1094 t->parms.iph.saddr = p->iph.saddr; 1095 t->parms.iph.daddr = p->iph.daddr; 1096 memcpy(t->dev->dev_addr, &p->iph.saddr, 4); 1097 memcpy(t->dev->broadcast, &p->iph.daddr, 4); 1098 ipip6_tunnel_link(sitn, t); 1099 t->parms.iph.ttl = p->iph.ttl; 1100 t->parms.iph.tos = p->iph.tos; 1101 t->parms.iph.frag_off = p->iph.frag_off; 1102 if (t->parms.link != p->link || t->fwmark != fwmark) { 1103 t->parms.link = p->link; 1104 t->fwmark = fwmark; 1105 ipip6_tunnel_bind_dev(t->dev); 1106 } 1107 dst_cache_reset(&t->dst_cache); 1108 netdev_state_change(t->dev); 1109 } 1110 1111 #ifdef CONFIG_IPV6_SIT_6RD 1112 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, 1113 struct ip_tunnel_6rd *ip6rd) 1114 { 1115 struct in6_addr prefix; 1116 __be32 relay_prefix; 1117 1118 if (ip6rd->relay_prefixlen > 32 || 1119 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) 1120 return -EINVAL; 1121 1122 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); 1123 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) 1124 return -EINVAL; 1125 if (ip6rd->relay_prefixlen) 1126 relay_prefix = ip6rd->relay_prefix & 1127 htonl(0xffffffffUL << 1128 (32 - ip6rd->relay_prefixlen)); 1129 else 1130 relay_prefix = 0; 1131 if (relay_prefix != ip6rd->relay_prefix) 1132 return -EINVAL; 1133 1134 t->ip6rd.prefix = prefix; 1135 t->ip6rd.relay_prefix = relay_prefix; 1136 t->ip6rd.prefixlen = ip6rd->prefixlen; 1137 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; 1138 dst_cache_reset(&t->dst_cache); 1139 netdev_state_change(t->dev); 1140 return 0; 1141 } 1142 #endif 1143 1144 static bool ipip6_valid_ip_proto(u8 ipproto) 1145 { 1146 return ipproto == IPPROTO_IPV6 || 1147 ipproto == IPPROTO_IPIP || 1148 #if IS_ENABLED(CONFIG_MPLS) 1149 ipproto == IPPROTO_MPLS || 1150 #endif 1151 ipproto == 0; 1152 } 1153 1154 static int 1155 ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1156 { 1157 int err = 0; 1158 struct ip_tunnel_parm p; 1159 struct ip_tunnel_prl prl; 1160 struct ip_tunnel *t = netdev_priv(dev); 1161 struct net *net = t->net; 1162 struct sit_net *sitn = net_generic(net, sit_net_id); 1163 #ifdef CONFIG_IPV6_SIT_6RD 1164 struct ip_tunnel_6rd ip6rd; 1165 #endif 1166 1167 switch (cmd) { 1168 case SIOCGETTUNNEL: 1169 #ifdef CONFIG_IPV6_SIT_6RD 1170 case SIOCGET6RD: 1171 #endif 1172 if (dev == sitn->fb_tunnel_dev) { 1173 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 1174 err = -EFAULT; 1175 break; 1176 } 1177 t = ipip6_tunnel_locate(net, &p, 0); 1178 if (!t) 1179 t = netdev_priv(dev); 1180 } 1181 1182 err = -EFAULT; 1183 if (cmd == SIOCGETTUNNEL) { 1184 memcpy(&p, &t->parms, sizeof(p)); 1185 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 1186 sizeof(p))) 1187 goto done; 1188 #ifdef CONFIG_IPV6_SIT_6RD 1189 } else { 1190 ip6rd.prefix = t->ip6rd.prefix; 1191 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 1192 ip6rd.prefixlen = t->ip6rd.prefixlen; 1193 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 1194 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 1195 sizeof(ip6rd))) 1196 goto done; 1197 #endif 1198 } 1199 err = 0; 1200 break; 1201 1202 case SIOCADDTUNNEL: 1203 case SIOCCHGTUNNEL: 1204 err = -EPERM; 1205 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1206 goto done; 1207 1208 err = -EFAULT; 1209 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1210 goto done; 1211 1212 err = -EINVAL; 1213 if (!ipip6_valid_ip_proto(p.iph.protocol)) 1214 goto done; 1215 if (p.iph.version != 4 || 1216 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 1217 goto done; 1218 if (p.iph.ttl) 1219 p.iph.frag_off |= htons(IP_DF); 1220 1221 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 1222 1223 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 1224 if (t) { 1225 if (t->dev != dev) { 1226 err = -EEXIST; 1227 break; 1228 } 1229 } else { 1230 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 1231 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 1232 err = -EINVAL; 1233 break; 1234 } 1235 t = netdev_priv(dev); 1236 } 1237 1238 ipip6_tunnel_update(t, &p, t->fwmark); 1239 } 1240 1241 if (t) { 1242 err = 0; 1243 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 1244 err = -EFAULT; 1245 } else 1246 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1247 break; 1248 1249 case SIOCDELTUNNEL: 1250 err = -EPERM; 1251 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1252 goto done; 1253 1254 if (dev == sitn->fb_tunnel_dev) { 1255 err = -EFAULT; 1256 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1257 goto done; 1258 err = -ENOENT; 1259 t = ipip6_tunnel_locate(net, &p, 0); 1260 if (!t) 1261 goto done; 1262 err = -EPERM; 1263 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1264 goto done; 1265 dev = t->dev; 1266 } 1267 unregister_netdevice(dev); 1268 err = 0; 1269 break; 1270 1271 case SIOCGETPRL: 1272 err = -EINVAL; 1273 if (dev == sitn->fb_tunnel_dev) 1274 goto done; 1275 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1276 break; 1277 1278 case SIOCADDPRL: 1279 case SIOCDELPRL: 1280 case SIOCCHGPRL: 1281 err = -EPERM; 1282 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1283 goto done; 1284 err = -EINVAL; 1285 if (dev == sitn->fb_tunnel_dev) 1286 goto done; 1287 err = -EFAULT; 1288 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1289 goto done; 1290 1291 switch (cmd) { 1292 case SIOCDELPRL: 1293 err = ipip6_tunnel_del_prl(t, &prl); 1294 break; 1295 case SIOCADDPRL: 1296 case SIOCCHGPRL: 1297 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1298 break; 1299 } 1300 dst_cache_reset(&t->dst_cache); 1301 netdev_state_change(dev); 1302 break; 1303 1304 #ifdef CONFIG_IPV6_SIT_6RD 1305 case SIOCADD6RD: 1306 case SIOCCHG6RD: 1307 case SIOCDEL6RD: 1308 err = -EPERM; 1309 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1310 goto done; 1311 1312 err = -EFAULT; 1313 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1314 sizeof(ip6rd))) 1315 goto done; 1316 1317 if (cmd != SIOCDEL6RD) { 1318 err = ipip6_tunnel_update_6rd(t, &ip6rd); 1319 if (err < 0) 1320 goto done; 1321 } else 1322 ipip6_tunnel_clone_6rd(dev, sitn); 1323 1324 err = 0; 1325 break; 1326 #endif 1327 1328 default: 1329 err = -EINVAL; 1330 } 1331 1332 done: 1333 return err; 1334 } 1335 1336 static const struct net_device_ops ipip6_netdev_ops = { 1337 .ndo_init = ipip6_tunnel_init, 1338 .ndo_uninit = ipip6_tunnel_uninit, 1339 .ndo_start_xmit = sit_tunnel_xmit, 1340 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1341 .ndo_get_stats64 = ip_tunnel_get_stats64, 1342 .ndo_get_iflink = ip_tunnel_get_iflink, 1343 }; 1344 1345 static void ipip6_dev_free(struct net_device *dev) 1346 { 1347 struct ip_tunnel *tunnel = netdev_priv(dev); 1348 1349 dst_cache_destroy(&tunnel->dst_cache); 1350 free_percpu(dev->tstats); 1351 } 1352 1353 #define SIT_FEATURES (NETIF_F_SG | \ 1354 NETIF_F_FRAGLIST | \ 1355 NETIF_F_HIGHDMA | \ 1356 NETIF_F_GSO_SOFTWARE | \ 1357 NETIF_F_HW_CSUM) 1358 1359 static void ipip6_tunnel_setup(struct net_device *dev) 1360 { 1361 struct ip_tunnel *tunnel = netdev_priv(dev); 1362 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 1363 1364 dev->netdev_ops = &ipip6_netdev_ops; 1365 dev->needs_free_netdev = true; 1366 dev->priv_destructor = ipip6_dev_free; 1367 1368 dev->type = ARPHRD_SIT; 1369 dev->hard_header_len = LL_MAX_HEADER + t_hlen; 1370 dev->mtu = ETH_DATA_LEN - t_hlen; 1371 dev->min_mtu = IPV6_MIN_MTU; 1372 dev->max_mtu = 0xFFF8 - t_hlen; 1373 dev->flags = IFF_NOARP; 1374 netif_keep_dst(dev); 1375 dev->addr_len = 4; 1376 dev->features |= NETIF_F_LLTX; 1377 dev->features |= SIT_FEATURES; 1378 dev->hw_features |= SIT_FEATURES; 1379 } 1380 1381 static int ipip6_tunnel_init(struct net_device *dev) 1382 { 1383 struct ip_tunnel *tunnel = netdev_priv(dev); 1384 int err; 1385 1386 tunnel->dev = dev; 1387 tunnel->net = dev_net(dev); 1388 strcpy(tunnel->parms.name, dev->name); 1389 1390 ipip6_tunnel_bind_dev(dev); 1391 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1392 if (!dev->tstats) 1393 return -ENOMEM; 1394 1395 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); 1396 if (err) { 1397 free_percpu(dev->tstats); 1398 dev->tstats = NULL; 1399 return err; 1400 } 1401 1402 return 0; 1403 } 1404 1405 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1406 { 1407 struct ip_tunnel *tunnel = netdev_priv(dev); 1408 struct iphdr *iph = &tunnel->parms.iph; 1409 struct net *net = dev_net(dev); 1410 struct sit_net *sitn = net_generic(net, sit_net_id); 1411 1412 iph->version = 4; 1413 iph->protocol = IPPROTO_IPV6; 1414 iph->ihl = 5; 1415 iph->ttl = 64; 1416 1417 dev_hold(dev); 1418 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1419 } 1420 1421 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[], 1422 struct netlink_ext_ack *extack) 1423 { 1424 u8 proto; 1425 1426 if (!data || !data[IFLA_IPTUN_PROTO]) 1427 return 0; 1428 1429 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1430 if (!ipip6_valid_ip_proto(proto)) 1431 return -EINVAL; 1432 1433 return 0; 1434 } 1435 1436 static void ipip6_netlink_parms(struct nlattr *data[], 1437 struct ip_tunnel_parm *parms, 1438 __u32 *fwmark) 1439 { 1440 memset(parms, 0, sizeof(*parms)); 1441 1442 parms->iph.version = 4; 1443 parms->iph.protocol = IPPROTO_IPV6; 1444 parms->iph.ihl = 5; 1445 parms->iph.ttl = 64; 1446 1447 if (!data) 1448 return; 1449 1450 if (data[IFLA_IPTUN_LINK]) 1451 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1452 1453 if (data[IFLA_IPTUN_LOCAL]) 1454 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); 1455 1456 if (data[IFLA_IPTUN_REMOTE]) 1457 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); 1458 1459 if (data[IFLA_IPTUN_TTL]) { 1460 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); 1461 if (parms->iph.ttl) 1462 parms->iph.frag_off = htons(IP_DF); 1463 } 1464 1465 if (data[IFLA_IPTUN_TOS]) 1466 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); 1467 1468 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) 1469 parms->iph.frag_off = htons(IP_DF); 1470 1471 if (data[IFLA_IPTUN_FLAGS]) 1472 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); 1473 1474 if (data[IFLA_IPTUN_PROTO]) 1475 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1476 1477 if (data[IFLA_IPTUN_FWMARK]) 1478 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]); 1479 } 1480 1481 /* This function returns true when ENCAP attributes are present in the nl msg */ 1482 static bool ipip6_netlink_encap_parms(struct nlattr *data[], 1483 struct ip_tunnel_encap *ipencap) 1484 { 1485 bool ret = false; 1486 1487 memset(ipencap, 0, sizeof(*ipencap)); 1488 1489 if (!data) 1490 return ret; 1491 1492 if (data[IFLA_IPTUN_ENCAP_TYPE]) { 1493 ret = true; 1494 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]); 1495 } 1496 1497 if (data[IFLA_IPTUN_ENCAP_FLAGS]) { 1498 ret = true; 1499 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]); 1500 } 1501 1502 if (data[IFLA_IPTUN_ENCAP_SPORT]) { 1503 ret = true; 1504 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]); 1505 } 1506 1507 if (data[IFLA_IPTUN_ENCAP_DPORT]) { 1508 ret = true; 1509 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]); 1510 } 1511 1512 return ret; 1513 } 1514 1515 #ifdef CONFIG_IPV6_SIT_6RD 1516 /* This function returns true when 6RD attributes are present in the nl msg */ 1517 static bool ipip6_netlink_6rd_parms(struct nlattr *data[], 1518 struct ip_tunnel_6rd *ip6rd) 1519 { 1520 bool ret = false; 1521 memset(ip6rd, 0, sizeof(*ip6rd)); 1522 1523 if (!data) 1524 return ret; 1525 1526 if (data[IFLA_IPTUN_6RD_PREFIX]) { 1527 ret = true; 1528 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]); 1529 } 1530 1531 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { 1532 ret = true; 1533 ip6rd->relay_prefix = 1534 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); 1535 } 1536 1537 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { 1538 ret = true; 1539 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); 1540 } 1541 1542 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { 1543 ret = true; 1544 ip6rd->relay_prefixlen = 1545 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); 1546 } 1547 1548 return ret; 1549 } 1550 #endif 1551 1552 static int ipip6_newlink(struct net *src_net, struct net_device *dev, 1553 struct nlattr *tb[], struct nlattr *data[], 1554 struct netlink_ext_ack *extack) 1555 { 1556 struct net *net = dev_net(dev); 1557 struct ip_tunnel *nt; 1558 struct ip_tunnel_encap ipencap; 1559 #ifdef CONFIG_IPV6_SIT_6RD 1560 struct ip_tunnel_6rd ip6rd; 1561 #endif 1562 int err; 1563 1564 nt = netdev_priv(dev); 1565 1566 if (ipip6_netlink_encap_parms(data, &ipencap)) { 1567 err = ip_tunnel_encap_setup(nt, &ipencap); 1568 if (err < 0) 1569 return err; 1570 } 1571 1572 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark); 1573 1574 if (ipip6_tunnel_locate(net, &nt->parms, 0)) 1575 return -EEXIST; 1576 1577 err = ipip6_tunnel_create(dev); 1578 if (err < 0) 1579 return err; 1580 1581 #ifdef CONFIG_IPV6_SIT_6RD 1582 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1583 err = ipip6_tunnel_update_6rd(nt, &ip6rd); 1584 #endif 1585 1586 return err; 1587 } 1588 1589 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], 1590 struct nlattr *data[], 1591 struct netlink_ext_ack *extack) 1592 { 1593 struct ip_tunnel *t = netdev_priv(dev); 1594 struct ip_tunnel_parm p; 1595 struct ip_tunnel_encap ipencap; 1596 struct net *net = t->net; 1597 struct sit_net *sitn = net_generic(net, sit_net_id); 1598 #ifdef CONFIG_IPV6_SIT_6RD 1599 struct ip_tunnel_6rd ip6rd; 1600 #endif 1601 __u32 fwmark = t->fwmark; 1602 int err; 1603 1604 if (dev == sitn->fb_tunnel_dev) 1605 return -EINVAL; 1606 1607 if (ipip6_netlink_encap_parms(data, &ipencap)) { 1608 err = ip_tunnel_encap_setup(t, &ipencap); 1609 if (err < 0) 1610 return err; 1611 } 1612 1613 ipip6_netlink_parms(data, &p, &fwmark); 1614 1615 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || 1616 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) 1617 return -EINVAL; 1618 1619 t = ipip6_tunnel_locate(net, &p, 0); 1620 1621 if (t) { 1622 if (t->dev != dev) 1623 return -EEXIST; 1624 } else 1625 t = netdev_priv(dev); 1626 1627 ipip6_tunnel_update(t, &p, fwmark); 1628 1629 #ifdef CONFIG_IPV6_SIT_6RD 1630 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1631 return ipip6_tunnel_update_6rd(t, &ip6rd); 1632 #endif 1633 1634 return 0; 1635 } 1636 1637 static size_t ipip6_get_size(const struct net_device *dev) 1638 { 1639 return 1640 /* IFLA_IPTUN_LINK */ 1641 nla_total_size(4) + 1642 /* IFLA_IPTUN_LOCAL */ 1643 nla_total_size(4) + 1644 /* IFLA_IPTUN_REMOTE */ 1645 nla_total_size(4) + 1646 /* IFLA_IPTUN_TTL */ 1647 nla_total_size(1) + 1648 /* IFLA_IPTUN_TOS */ 1649 nla_total_size(1) + 1650 /* IFLA_IPTUN_PMTUDISC */ 1651 nla_total_size(1) + 1652 /* IFLA_IPTUN_FLAGS */ 1653 nla_total_size(2) + 1654 /* IFLA_IPTUN_PROTO */ 1655 nla_total_size(1) + 1656 #ifdef CONFIG_IPV6_SIT_6RD 1657 /* IFLA_IPTUN_6RD_PREFIX */ 1658 nla_total_size(sizeof(struct in6_addr)) + 1659 /* IFLA_IPTUN_6RD_RELAY_PREFIX */ 1660 nla_total_size(4) + 1661 /* IFLA_IPTUN_6RD_PREFIXLEN */ 1662 nla_total_size(2) + 1663 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ 1664 nla_total_size(2) + 1665 #endif 1666 /* IFLA_IPTUN_ENCAP_TYPE */ 1667 nla_total_size(2) + 1668 /* IFLA_IPTUN_ENCAP_FLAGS */ 1669 nla_total_size(2) + 1670 /* IFLA_IPTUN_ENCAP_SPORT */ 1671 nla_total_size(2) + 1672 /* IFLA_IPTUN_ENCAP_DPORT */ 1673 nla_total_size(2) + 1674 /* IFLA_IPTUN_FWMARK */ 1675 nla_total_size(4) + 1676 0; 1677 } 1678 1679 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1680 { 1681 struct ip_tunnel *tunnel = netdev_priv(dev); 1682 struct ip_tunnel_parm *parm = &tunnel->parms; 1683 1684 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1685 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || 1686 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || 1687 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || 1688 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || 1689 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, 1690 !!(parm->iph.frag_off & htons(IP_DF))) || 1691 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || 1692 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) || 1693 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark)) 1694 goto nla_put_failure; 1695 1696 #ifdef CONFIG_IPV6_SIT_6RD 1697 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX, 1698 &tunnel->ip6rd.prefix) || 1699 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, 1700 tunnel->ip6rd.relay_prefix) || 1701 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, 1702 tunnel->ip6rd.prefixlen) || 1703 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, 1704 tunnel->ip6rd.relay_prefixlen)) 1705 goto nla_put_failure; 1706 #endif 1707 1708 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, 1709 tunnel->encap.type) || 1710 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, 1711 tunnel->encap.sport) || 1712 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, 1713 tunnel->encap.dport) || 1714 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, 1715 tunnel->encap.flags)) 1716 goto nla_put_failure; 1717 1718 return 0; 1719 1720 nla_put_failure: 1721 return -EMSGSIZE; 1722 } 1723 1724 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { 1725 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1726 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, 1727 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, 1728 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1729 [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, 1730 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, 1731 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, 1732 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1733 #ifdef CONFIG_IPV6_SIT_6RD 1734 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, 1735 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, 1736 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, 1737 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, 1738 #endif 1739 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 }, 1740 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 }, 1741 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 }, 1742 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 }, 1743 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 }, 1744 }; 1745 1746 static void ipip6_dellink(struct net_device *dev, struct list_head *head) 1747 { 1748 struct net *net = dev_net(dev); 1749 struct sit_net *sitn = net_generic(net, sit_net_id); 1750 1751 if (dev != sitn->fb_tunnel_dev) 1752 unregister_netdevice_queue(dev, head); 1753 } 1754 1755 static struct rtnl_link_ops sit_link_ops __read_mostly = { 1756 .kind = "sit", 1757 .maxtype = IFLA_IPTUN_MAX, 1758 .policy = ipip6_policy, 1759 .priv_size = sizeof(struct ip_tunnel), 1760 .setup = ipip6_tunnel_setup, 1761 .validate = ipip6_validate, 1762 .newlink = ipip6_newlink, 1763 .changelink = ipip6_changelink, 1764 .get_size = ipip6_get_size, 1765 .fill_info = ipip6_fill_info, 1766 .dellink = ipip6_dellink, 1767 .get_link_net = ip_tunnel_get_link_net, 1768 }; 1769 1770 static struct xfrm_tunnel sit_handler __read_mostly = { 1771 .handler = ipip6_rcv, 1772 .err_handler = ipip6_err, 1773 .priority = 1, 1774 }; 1775 1776 static struct xfrm_tunnel ipip_handler __read_mostly = { 1777 .handler = ipip_rcv, 1778 .err_handler = ipip6_err, 1779 .priority = 2, 1780 }; 1781 1782 #if IS_ENABLED(CONFIG_MPLS) 1783 static struct xfrm_tunnel mplsip_handler __read_mostly = { 1784 .handler = mplsip_rcv, 1785 .err_handler = ipip6_err, 1786 .priority = 2, 1787 }; 1788 #endif 1789 1790 static void __net_exit sit_destroy_tunnels(struct net *net, 1791 struct list_head *head) 1792 { 1793 struct sit_net *sitn = net_generic(net, sit_net_id); 1794 struct net_device *dev, *aux; 1795 int prio; 1796 1797 for_each_netdev_safe(net, dev, aux) 1798 if (dev->rtnl_link_ops == &sit_link_ops) 1799 unregister_netdevice_queue(dev, head); 1800 1801 for (prio = 1; prio < 4; prio++) { 1802 int h; 1803 for (h = 0; h < IP6_SIT_HASH_SIZE; h++) { 1804 struct ip_tunnel *t; 1805 1806 t = rtnl_dereference(sitn->tunnels[prio][h]); 1807 while (t) { 1808 /* If dev is in the same netns, it has already 1809 * been added to the list by the previous loop. 1810 */ 1811 if (!net_eq(dev_net(t->dev), net)) 1812 unregister_netdevice_queue(t->dev, 1813 head); 1814 t = rtnl_dereference(t->next); 1815 } 1816 } 1817 } 1818 } 1819 1820 static int __net_init sit_init_net(struct net *net) 1821 { 1822 struct sit_net *sitn = net_generic(net, sit_net_id); 1823 struct ip_tunnel *t; 1824 int err; 1825 1826 sitn->tunnels[0] = sitn->tunnels_wc; 1827 sitn->tunnels[1] = sitn->tunnels_l; 1828 sitn->tunnels[2] = sitn->tunnels_r; 1829 sitn->tunnels[3] = sitn->tunnels_r_l; 1830 1831 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1832 NET_NAME_UNKNOWN, 1833 ipip6_tunnel_setup); 1834 if (!sitn->fb_tunnel_dev) { 1835 err = -ENOMEM; 1836 goto err_alloc_dev; 1837 } 1838 dev_net_set(sitn->fb_tunnel_dev, net); 1839 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; 1840 /* FB netdevice is special: we have one, and only one per netns. 1841 * Allowing to move it to another netns is clearly unsafe. 1842 */ 1843 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1844 1845 err = register_netdev(sitn->fb_tunnel_dev); 1846 if (err) 1847 goto err_reg_dev; 1848 1849 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1850 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1851 1852 t = netdev_priv(sitn->fb_tunnel_dev); 1853 1854 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1855 return 0; 1856 1857 err_reg_dev: 1858 ipip6_dev_free(sitn->fb_tunnel_dev); 1859 err_alloc_dev: 1860 return err; 1861 } 1862 1863 static void __net_exit sit_exit_batch_net(struct list_head *net_list) 1864 { 1865 LIST_HEAD(list); 1866 struct net *net; 1867 1868 rtnl_lock(); 1869 list_for_each_entry(net, net_list, exit_list) 1870 sit_destroy_tunnels(net, &list); 1871 1872 unregister_netdevice_many(&list); 1873 rtnl_unlock(); 1874 } 1875 1876 static struct pernet_operations sit_net_ops = { 1877 .init = sit_init_net, 1878 .exit_batch = sit_exit_batch_net, 1879 .id = &sit_net_id, 1880 .size = sizeof(struct sit_net), 1881 }; 1882 1883 static void __exit sit_cleanup(void) 1884 { 1885 rtnl_link_unregister(&sit_link_ops); 1886 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1887 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1888 #if IS_ENABLED(CONFIG_MPLS) 1889 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS); 1890 #endif 1891 1892 unregister_pernet_device(&sit_net_ops); 1893 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1894 } 1895 1896 static int __init sit_init(void) 1897 { 1898 int err; 1899 1900 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n"); 1901 1902 err = register_pernet_device(&sit_net_ops); 1903 if (err < 0) 1904 return err; 1905 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1906 if (err < 0) { 1907 pr_info("%s: can't register ip6ip4\n", __func__); 1908 goto xfrm_tunnel_failed; 1909 } 1910 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 1911 if (err < 0) { 1912 pr_info("%s: can't register ip4ip4\n", __func__); 1913 goto xfrm_tunnel4_failed; 1914 } 1915 #if IS_ENABLED(CONFIG_MPLS) 1916 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS); 1917 if (err < 0) { 1918 pr_info("%s: can't register mplsip\n", __func__); 1919 goto xfrm_tunnel_mpls_failed; 1920 } 1921 #endif 1922 err = rtnl_link_register(&sit_link_ops); 1923 if (err < 0) 1924 goto rtnl_link_failed; 1925 1926 out: 1927 return err; 1928 1929 rtnl_link_failed: 1930 #if IS_ENABLED(CONFIG_MPLS) 1931 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS); 1932 xfrm_tunnel_mpls_failed: 1933 #endif 1934 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1935 xfrm_tunnel4_failed: 1936 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1937 xfrm_tunnel_failed: 1938 unregister_pernet_device(&sit_net_ops); 1939 goto out; 1940 } 1941 1942 module_init(sit_init); 1943 module_exit(sit_cleanup); 1944 MODULE_LICENSE("GPL"); 1945 MODULE_ALIAS_RTNL_LINK("sit"); 1946 MODULE_ALIAS_NETDEV("sit0"); 1947