1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT) 4 * Linux INET6 implementation 5 * 6 * Authors: 7 * Pedro Roque <roque@di.fc.ul.pt> 8 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 9 * 10 * Changes: 11 * Roger Venning <r.venning@telstra.com>: 6to4 support 12 * Nate Thompson <nate@thebog.net>: 6to4 support 13 * Fred Templin <fred.l.templin@boeing.com>: isatap support 14 */ 15 16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18#include <linux/module.h> 19#include <linux/capability.h> 20#include <linux/errno.h> 21#include <linux/types.h> 22#include <linux/socket.h> 23#include <linux/sockios.h> 24#include <linux/net.h> 25#include <linux/in6.h> 26#include <linux/netdevice.h> 27#include <linux/if_arp.h> 28#include <linux/icmp.h> 29#include <linux/slab.h> 30#include <linux/uaccess.h> 31#include <linux/init.h> 32#include <linux/netfilter_ipv4.h> 33#include <linux/if_ether.h> 34 35#include <net/sock.h> 36#include <net/snmp.h> 37 38#include <net/ipv6.h> 39#include <net/protocol.h> 40#include <net/transp_v6.h> 41#include <net/ip6_fib.h> 42#include <net/ip6_route.h> 43#include <net/ndisc.h> 44#include <net/addrconf.h> 45#include <net/ip.h> 46#include <net/udp.h> 47#include <net/icmp.h> 48#include <net/ip_tunnels.h> 49#include <net/inet_ecn.h> 50#include <net/xfrm.h> 51#include <net/dsfield.h> 52#include <net/net_namespace.h> 53#include <net/netns/generic.h> 54 55/* 56 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 57 58 For comments look at net/ipv4/ip_gre.c --ANK 59 */ 60 61#define IP6_SIT_HASH_SIZE 16 62#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 63 64static bool log_ecn_error = true; 65module_param(log_ecn_error, bool, 0644); 66MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 67 68static int ipip6_tunnel_init(struct net_device *dev); 69static void ipip6_tunnel_setup(struct net_device *dev); 70static void ipip6_dev_free(struct net_device *dev); 71static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 72 __be32 *v4dst); 73static struct rtnl_link_ops sit_link_ops __read_mostly; 74 75static unsigned int sit_net_id __read_mostly; 76struct sit_net { 77 struct ip_tunnel __rcu *tunnels_r_l[IP6_SIT_HASH_SIZE]; 78 struct ip_tunnel __rcu *tunnels_r[IP6_SIT_HASH_SIZE]; 79 struct ip_tunnel __rcu *tunnels_l[IP6_SIT_HASH_SIZE]; 80 struct ip_tunnel __rcu *tunnels_wc[1]; 81 struct ip_tunnel __rcu **tunnels[4]; 82 83 struct net_device *fb_tunnel_dev; 84}; 85 86static inline struct sit_net *dev_to_sit_net(struct net_device *dev) 87{ 88 struct ip_tunnel *t = netdev_priv(dev); 89 90 return net_generic(t->net, sit_net_id); 91} 92 93/* 94 * Must be invoked with rcu_read_lock 95 */ 96static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net, 97 struct net_device *dev, 98 __be32 remote, __be32 local, 99 int sifindex) 100{ 101 unsigned int h0 = HASH(remote); 102 unsigned int h1 = HASH(local); 103 struct ip_tunnel *t; 104 struct sit_net *sitn = net_generic(net, sit_net_id); 105 int ifindex = dev ? dev->ifindex : 0; 106 107 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) { 108 if (local == t->parms.iph.saddr && 109 remote == t->parms.iph.daddr && 110 (!dev || !t->parms.link || ifindex == t->parms.link || 111 sifindex == t->parms.link) && 112 (t->dev->flags & IFF_UP)) 113 return t; 114 } 115 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) { 116 if (remote == t->parms.iph.daddr && 117 (!dev || !t->parms.link || ifindex == t->parms.link || 118 sifindex == t->parms.link) && 119 (t->dev->flags & IFF_UP)) 120 return t; 121 } 122 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) { 123 if (local == t->parms.iph.saddr && 124 (!dev || !t->parms.link || ifindex == t->parms.link || 125 sifindex == t->parms.link) && 126 (t->dev->flags & IFF_UP)) 127 return t; 128 } 129 t = rcu_dereference(sitn->tunnels_wc[0]); 130 if (t && (t->dev->flags & IFF_UP)) 131 return t; 132 return NULL; 133} 134 135static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn, 136 struct ip_tunnel_parm *parms) 137{ 138 __be32 remote = parms->iph.daddr; 139 __be32 local = parms->iph.saddr; 140 unsigned int h = 0; 141 int prio = 0; 142 143 if (remote) { 144 prio |= 2; 145 h ^= HASH(remote); 146 } 147 if (local) { 148 prio |= 1; 149 h ^= HASH(local); 150 } 151 return &sitn->tunnels[prio][h]; 152} 153 154static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn, 155 struct ip_tunnel *t) 156{ 157 return __ipip6_bucket(sitn, &t->parms); 158} 159 160static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 161{ 162 struct ip_tunnel __rcu **tp; 163 struct ip_tunnel *iter; 164 165 for (tp = ipip6_bucket(sitn, t); 166 (iter = rtnl_dereference(*tp)) != NULL; 167 tp = &iter->next) { 168 if (t == iter) { 169 rcu_assign_pointer(*tp, t->next); 170 break; 171 } 172 } 173} 174 175static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 176{ 177 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t); 178 179 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 180 rcu_assign_pointer(*tp, t); 181} 182 183static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 184{ 185#ifdef CONFIG_IPV6_SIT_6RD 186 struct ip_tunnel *t = netdev_priv(dev); 187 188 if (dev == sitn->fb_tunnel_dev || !sitn->fb_tunnel_dev) { 189 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 190 t->ip6rd.relay_prefix = 0; 191 t->ip6rd.prefixlen = 16; 192 t->ip6rd.relay_prefixlen = 0; 193 } else { 194 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 195 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 196 } 197#endif 198} 199 200static int ipip6_tunnel_create(struct net_device *dev) 201{ 202 struct ip_tunnel *t = netdev_priv(dev); 203 struct net *net = dev_net(dev); 204 struct sit_net *sitn = net_generic(net, sit_net_id); 205 int err; 206 207 __dev_addr_set(dev, &t->parms.iph.saddr, 4); 208 memcpy(dev->broadcast, &t->parms.iph.daddr, 4); 209 210 if ((__force u16)t->parms.i_flags & SIT_ISATAP) 211 dev->priv_flags |= IFF_ISATAP; 212 213 dev->rtnl_link_ops = &sit_link_ops; 214 215 err = register_netdevice(dev); 216 if (err < 0) 217 goto out; 218 219 ipip6_tunnel_clone_6rd(dev, sitn); 220 221 ipip6_tunnel_link(sitn, t); 222 return 0; 223 224out: 225 return err; 226} 227 228static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, 229 struct ip_tunnel_parm *parms, int create) 230{ 231 __be32 remote = parms->iph.daddr; 232 __be32 local = parms->iph.saddr; 233 struct ip_tunnel *t, *nt; 234 struct ip_tunnel __rcu **tp; 235 struct net_device *dev; 236 char name[IFNAMSIZ]; 237 struct sit_net *sitn = net_generic(net, sit_net_id); 238 239 for (tp = __ipip6_bucket(sitn, parms); 240 (t = rtnl_dereference(*tp)) != NULL; 241 tp = &t->next) { 242 if (local == t->parms.iph.saddr && 243 remote == t->parms.iph.daddr && 244 parms->link == t->parms.link) { 245 if (create) 246 return NULL; 247 else 248 return t; 249 } 250 } 251 if (!create) 252 goto failed; 253 254 if (parms->name[0]) { 255 if (!dev_valid_name(parms->name)) 256 goto failed; 257 strscpy(name, parms->name, IFNAMSIZ); 258 } else { 259 strcpy(name, "sit%d"); 260 } 261 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, 262 ipip6_tunnel_setup); 263 if (!dev) 264 return NULL; 265 266 dev_net_set(dev, net); 267 268 nt = netdev_priv(dev); 269 270 nt->parms = *parms; 271 if (ipip6_tunnel_create(dev) < 0) 272 goto failed_free; 273 274 if (!parms->name[0]) 275 strcpy(parms->name, dev->name); 276 277 return nt; 278 279failed_free: 280 free_netdev(dev); 281failed: 282 return NULL; 283} 284 285#define for_each_prl_rcu(start) \ 286 for (prl = rcu_dereference(start); \ 287 prl; \ 288 prl = rcu_dereference(prl->next)) 289 290static struct ip_tunnel_prl_entry * 291__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 292{ 293 struct ip_tunnel_prl_entry *prl; 294 295 for_each_prl_rcu(t->prl) 296 if (prl->addr == addr) 297 break; 298 return prl; 299 300} 301 302static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __user *a) 303{ 304 struct ip_tunnel *t = netdev_priv(dev); 305 struct ip_tunnel_prl kprl, *kp; 306 struct ip_tunnel_prl_entry *prl; 307 unsigned int cmax, c = 0, ca, len; 308 int ret = 0; 309 310 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) 311 return -EINVAL; 312 313 if (copy_from_user(&kprl, a, sizeof(kprl))) 314 return -EFAULT; 315 cmax = kprl.datalen / sizeof(kprl); 316 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 317 cmax = 1; 318 319 /* For simple GET or for root users, 320 * we try harder to allocate. 321 */ 322 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 323 kcalloc(cmax, sizeof(*kp), GFP_KERNEL_ACCOUNT | __GFP_NOWARN) : 324 NULL; 325 326 ca = min(t->prl_count, cmax); 327 328 if (!kp) { 329 /* We don't try hard to allocate much memory for 330 * non-root users. 331 * For root users, retry allocating enough memory for 332 * the answer. 333 */ 334 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC | __GFP_ACCOUNT | 335 __GFP_NOWARN); 336 if (!kp) { 337 ret = -ENOMEM; 338 goto out; 339 } 340 } 341 342 rcu_read_lock(); 343 for_each_prl_rcu(t->prl) { 344 if (c >= cmax) 345 break; 346 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 347 continue; 348 kp[c].addr = prl->addr; 349 kp[c].flags = prl->flags; 350 c++; 351 if (kprl.addr != htonl(INADDR_ANY)) 352 break; 353 } 354 355 rcu_read_unlock(); 356 357 len = sizeof(*kp) * c; 358 ret = 0; 359 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 360 ret = -EFAULT; 361 362 kfree(kp); 363out: 364 return ret; 365} 366 367static int 368ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 369{ 370 struct ip_tunnel_prl_entry *p; 371 int err = 0; 372 373 if (a->addr == htonl(INADDR_ANY)) 374 return -EINVAL; 375 376 ASSERT_RTNL(); 377 378 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) { 379 if (p->addr == a->addr) { 380 if (chg) { 381 p->flags = a->flags; 382 goto out; 383 } 384 err = -EEXIST; 385 goto out; 386 } 387 } 388 389 if (chg) { 390 err = -ENXIO; 391 goto out; 392 } 393 394 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 395 if (!p) { 396 err = -ENOBUFS; 397 goto out; 398 } 399 400 p->next = t->prl; 401 p->addr = a->addr; 402 p->flags = a->flags; 403 t->prl_count++; 404 rcu_assign_pointer(t->prl, p); 405out: 406 return err; 407} 408 409static void prl_list_destroy_rcu(struct rcu_head *head) 410{ 411 struct ip_tunnel_prl_entry *p, *n; 412 413 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 414 do { 415 n = rcu_dereference_protected(p->next, 1); 416 kfree(p); 417 p = n; 418 } while (p); 419} 420 421static int 422ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 423{ 424 struct ip_tunnel_prl_entry *x; 425 struct ip_tunnel_prl_entry __rcu **p; 426 int err = 0; 427 428 ASSERT_RTNL(); 429 430 if (a && a->addr != htonl(INADDR_ANY)) { 431 for (p = &t->prl; 432 (x = rtnl_dereference(*p)) != NULL; 433 p = &x->next) { 434 if (x->addr == a->addr) { 435 *p = x->next; 436 kfree_rcu(x, rcu_head); 437 t->prl_count--; 438 goto out; 439 } 440 } 441 err = -ENXIO; 442 } else { 443 x = rtnl_dereference(t->prl); 444 if (x) { 445 t->prl_count = 0; 446 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 447 t->prl = NULL; 448 } 449 } 450out: 451 return err; 452} 453 454static int ipip6_tunnel_prl_ctl(struct net_device *dev, 455 struct ip_tunnel_prl __user *data, int cmd) 456{ 457 struct ip_tunnel *t = netdev_priv(dev); 458 struct ip_tunnel_prl prl; 459 int err; 460 461 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN)) 462 return -EPERM; 463 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) 464 return -EINVAL; 465 466 if (copy_from_user(&prl, data, sizeof(prl))) 467 return -EFAULT; 468 469 switch (cmd) { 470 case SIOCDELPRL: 471 err = ipip6_tunnel_del_prl(t, &prl); 472 break; 473 case SIOCADDPRL: 474 case SIOCCHGPRL: 475 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 476 break; 477 } 478 dst_cache_reset(&t->dst_cache); 479 netdev_state_change(dev); 480 return err; 481} 482 483static int 484isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t) 485{ 486 struct ip_tunnel_prl_entry *p; 487 int ok = 1; 488 489 rcu_read_lock(); 490 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 491 if (p) { 492 if (p->flags & PRL_DEFAULT) 493 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 494 else 495 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 496 } else { 497 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 498 499 if (ipv6_addr_is_isatap(addr6) && 500 (addr6->s6_addr32[3] == iph->saddr) && 501 ipv6_chk_prefix(addr6, t->dev)) 502 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 503 else 504 ok = 0; 505 } 506 rcu_read_unlock(); 507 return ok; 508} 509 510static void ipip6_tunnel_uninit(struct net_device *dev) 511{ 512 struct ip_tunnel *tunnel = netdev_priv(dev); 513 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id); 514 515 if (dev == sitn->fb_tunnel_dev) { 516 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL); 517 } else { 518 ipip6_tunnel_unlink(sitn, tunnel); 519 ipip6_tunnel_del_prl(tunnel, NULL); 520 } 521 dst_cache_reset(&tunnel->dst_cache); 522 netdev_put(dev, &tunnel->dev_tracker); 523} 524 525static int ipip6_err(struct sk_buff *skb, u32 info) 526{ 527 const struct iphdr *iph = (const struct iphdr *)skb->data; 528 const int type = icmp_hdr(skb)->type; 529 const int code = icmp_hdr(skb)->code; 530 unsigned int data_len = 0; 531 struct ip_tunnel *t; 532 int sifindex; 533 int err; 534 535 switch (type) { 536 default: 537 case ICMP_PARAMETERPROB: 538 return 0; 539 540 case ICMP_DEST_UNREACH: 541 switch (code) { 542 case ICMP_SR_FAILED: 543 /* Impossible event. */ 544 return 0; 545 default: 546 /* All others are translated to HOST_UNREACH. 547 rfc2003 contains "deep thoughts" about NET_UNREACH, 548 I believe they are just ether pollution. --ANK 549 */ 550 break; 551 } 552 break; 553 case ICMP_TIME_EXCEEDED: 554 if (code != ICMP_EXC_TTL) 555 return 0; 556 data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ 557 break; 558 case ICMP_REDIRECT: 559 break; 560 } 561 562 err = -ENOENT; 563 564 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; 565 t = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 566 iph->daddr, iph->saddr, sifindex); 567 if (!t) 568 goto out; 569 570 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 571 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 572 t->parms.link, iph->protocol); 573 err = 0; 574 goto out; 575 } 576 if (type == ICMP_REDIRECT) { 577 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 578 iph->protocol); 579 err = 0; 580 goto out; 581 } 582 583 err = 0; 584 if (__in6_dev_get(skb->dev) && 585 !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4, type, data_len)) 586 goto out; 587 588 if (t->parms.iph.daddr == 0) 589 goto out; 590 591 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 592 goto out; 593 594 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 595 t->err_count++; 596 else 597 t->err_count = 1; 598 t->err_time = jiffies; 599out: 600 return err; 601} 602 603static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, 604 const struct in6_addr *v6addr) 605{ 606 __be32 v4embed = 0; 607 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) 608 return true; 609 return false; 610} 611 612/* Checks if an address matches an address on the tunnel interface. 613 * Used to detect the NAT of proto 41 packets and let them pass spoofing test. 614 * Long story: 615 * This function is called after we considered the packet as spoofed 616 * in is_spoofed_6rd. 617 * We may have a router that is doing NAT for proto 41 packets 618 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb 619 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd 620 * function will return true, dropping the packet. 621 * But, we can still check if is spoofed against the IP 622 * addresses associated with the interface. 623 */ 624static bool only_dnatted(const struct ip_tunnel *tunnel, 625 const struct in6_addr *v6dst) 626{ 627 int prefix_len; 628 629#ifdef CONFIG_IPV6_SIT_6RD 630 prefix_len = tunnel->ip6rd.prefixlen + 32 631 - tunnel->ip6rd.relay_prefixlen; 632#else 633 prefix_len = 48; 634#endif 635 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev); 636} 637 638/* Returns true if a packet is spoofed */ 639static bool packet_is_spoofed(struct sk_buff *skb, 640 const struct iphdr *iph, 641 struct ip_tunnel *tunnel) 642{ 643 const struct ipv6hdr *ipv6h; 644 645 if (tunnel->dev->priv_flags & IFF_ISATAP) { 646 if (!isatap_chksrc(skb, iph, tunnel)) 647 return true; 648 649 return false; 650 } 651 652 if (tunnel->dev->flags & IFF_POINTOPOINT) 653 return false; 654 655 ipv6h = ipv6_hdr(skb); 656 657 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) { 658 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 659 &iph->saddr, &ipv6h->saddr, 660 &iph->daddr, &ipv6h->daddr); 661 return true; 662 } 663 664 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr))) 665 return false; 666 667 if (only_dnatted(tunnel, &ipv6h->daddr)) 668 return false; 669 670 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 671 &iph->saddr, &ipv6h->saddr, 672 &iph->daddr, &ipv6h->daddr); 673 return true; 674} 675 676static int ipip6_rcv(struct sk_buff *skb) 677{ 678 const struct iphdr *iph = ip_hdr(skb); 679 struct ip_tunnel *tunnel; 680 int sifindex; 681 int err; 682 683 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; 684 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 685 iph->saddr, iph->daddr, sifindex); 686 if (tunnel) { 687 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && 688 tunnel->parms.iph.protocol != 0) 689 goto out; 690 691 skb->mac_header = skb->network_header; 692 skb_reset_network_header(skb); 693 IPCB(skb)->flags = 0; 694 skb->dev = tunnel->dev; 695 696 if (packet_is_spoofed(skb, iph, tunnel)) { 697 DEV_STATS_INC(tunnel->dev, rx_errors); 698 goto out; 699 } 700 701 if (iptunnel_pull_header(skb, 0, htons(ETH_P_IPV6), 702 !net_eq(tunnel->net, dev_net(tunnel->dev)))) 703 goto out; 704 705 /* skb can be uncloned in iptunnel_pull_header, so 706 * old iph is no longer valid 707 */ 708 iph = (const struct iphdr *)skb_mac_header(skb); 709 skb_reset_mac_header(skb); 710 711 err = IP_ECN_decapsulate(iph, skb); 712 if (unlikely(err)) { 713 if (log_ecn_error) 714 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 715 &iph->saddr, iph->tos); 716 if (err > 1) { 717 DEV_STATS_INC(tunnel->dev, rx_frame_errors); 718 DEV_STATS_INC(tunnel->dev, rx_errors); 719 goto out; 720 } 721 } 722 723 dev_sw_netstats_rx_add(tunnel->dev, skb->len); 724 725 netif_rx(skb); 726 727 return 0; 728 } 729 730 /* no tunnel matched, let upstream know, ipsec may handle it */ 731 return 1; 732out: 733 kfree_skb(skb); 734 return 0; 735} 736 737static const struct tnl_ptk_info ipip_tpi = { 738 /* no tunnel info required for ipip. */ 739 .proto = htons(ETH_P_IP), 740}; 741 742#if IS_ENABLED(CONFIG_MPLS) 743static const struct tnl_ptk_info mplsip_tpi = { 744 /* no tunnel info required for mplsip. */ 745 .proto = htons(ETH_P_MPLS_UC), 746}; 747#endif 748 749static int sit_tunnel_rcv(struct sk_buff *skb, u8 ipproto) 750{ 751 const struct iphdr *iph; 752 struct ip_tunnel *tunnel; 753 int sifindex; 754 755 sifindex = netif_is_l3_master(skb->dev) ? IPCB(skb)->iif : 0; 756 757 iph = ip_hdr(skb); 758 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 759 iph->saddr, iph->daddr, sifindex); 760 if (tunnel) { 761 const struct tnl_ptk_info *tpi; 762 763 if (tunnel->parms.iph.protocol != ipproto && 764 tunnel->parms.iph.protocol != 0) 765 goto drop; 766 767 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 768 goto drop; 769#if IS_ENABLED(CONFIG_MPLS) 770 if (ipproto == IPPROTO_MPLS) 771 tpi = &mplsip_tpi; 772 else 773#endif 774 tpi = &ipip_tpi; 775 if (iptunnel_pull_header(skb, 0, tpi->proto, false)) 776 goto drop; 777 skb_reset_mac_header(skb); 778 779 return ip_tunnel_rcv(tunnel, skb, tpi, NULL, log_ecn_error); 780 } 781 782 return 1; 783 784drop: 785 kfree_skb(skb); 786 return 0; 787} 788 789static int ipip_rcv(struct sk_buff *skb) 790{ 791 return sit_tunnel_rcv(skb, IPPROTO_IPIP); 792} 793 794#if IS_ENABLED(CONFIG_MPLS) 795static int mplsip_rcv(struct sk_buff *skb) 796{ 797 return sit_tunnel_rcv(skb, IPPROTO_MPLS); 798} 799#endif 800 801/* 802 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function 803 * stores the embedded IPv4 address in v4dst and returns true. 804 */ 805static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 806 __be32 *v4dst) 807{ 808#ifdef CONFIG_IPV6_SIT_6RD 809 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 810 tunnel->ip6rd.prefixlen)) { 811 unsigned int pbw0, pbi0; 812 int pbi1; 813 u32 d; 814 815 pbw0 = tunnel->ip6rd.prefixlen >> 5; 816 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 817 818 d = tunnel->ip6rd.relay_prefixlen < 32 ? 819 (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 820 tunnel->ip6rd.relay_prefixlen : 0; 821 822 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 823 if (pbi1 > 0) 824 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 825 (32 - pbi1); 826 827 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); 828 return true; 829 } 830#else 831 if (v6dst->s6_addr16[0] == htons(0x2002)) { 832 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 833 memcpy(v4dst, &v6dst->s6_addr16[1], 4); 834 return true; 835 } 836#endif 837 return false; 838} 839 840static inline __be32 try_6rd(struct ip_tunnel *tunnel, 841 const struct in6_addr *v6dst) 842{ 843 __be32 dst = 0; 844 check_6rd(tunnel, v6dst, &dst); 845 return dst; 846} 847 848/* 849 * This function assumes it is being called from dev_queue_xmit() 850 * and that skb is filled properly by that function. 851 */ 852 853static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 854 struct net_device *dev) 855{ 856 struct ip_tunnel *tunnel = netdev_priv(dev); 857 const struct iphdr *tiph = &tunnel->parms.iph; 858 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 859 u8 tos = tunnel->parms.iph.tos; 860 __be16 df = tiph->frag_off; 861 struct rtable *rt; /* Route to the other host */ 862 struct net_device *tdev; /* Device to other host */ 863 unsigned int max_headroom; /* The extra header space needed */ 864 __be32 dst = tiph->daddr; 865 struct flowi4 fl4; 866 int mtu; 867 const struct in6_addr *addr6; 868 int addr_type; 869 u8 ttl; 870 u8 protocol = IPPROTO_IPV6; 871 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 872 873 if (tos == 1) 874 tos = ipv6_get_dsfield(iph6); 875 876 /* ISATAP (RFC4214) - must come before 6to4 */ 877 if (dev->priv_flags & IFF_ISATAP) { 878 struct neighbour *neigh = NULL; 879 bool do_tx_error = false; 880 881 if (skb_dst(skb)) 882 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 883 884 if (!neigh) { 885 net_dbg_ratelimited("nexthop == NULL\n"); 886 goto tx_error; 887 } 888 889 addr6 = (const struct in6_addr *)&neigh->primary_key; 890 addr_type = ipv6_addr_type(addr6); 891 892 if ((addr_type & IPV6_ADDR_UNICAST) && 893 ipv6_addr_is_isatap(addr6)) 894 dst = addr6->s6_addr32[3]; 895 else 896 do_tx_error = true; 897 898 neigh_release(neigh); 899 if (do_tx_error) 900 goto tx_error; 901 } 902 903 if (!dst) 904 dst = try_6rd(tunnel, &iph6->daddr); 905 906 if (!dst) { 907 struct neighbour *neigh = NULL; 908 bool do_tx_error = false; 909 910 if (skb_dst(skb)) 911 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 912 913 if (!neigh) { 914 net_dbg_ratelimited("nexthop == NULL\n"); 915 goto tx_error; 916 } 917 918 addr6 = (const struct in6_addr *)&neigh->primary_key; 919 addr_type = ipv6_addr_type(addr6); 920 921 if (addr_type == IPV6_ADDR_ANY) { 922 addr6 = &ipv6_hdr(skb)->daddr; 923 addr_type = ipv6_addr_type(addr6); 924 } 925 926 if ((addr_type & IPV6_ADDR_COMPATv4) != 0) 927 dst = addr6->s6_addr32[3]; 928 else 929 do_tx_error = true; 930 931 neigh_release(neigh); 932 if (do_tx_error) 933 goto tx_error; 934 } 935 936 flowi4_init_output(&fl4, tunnel->parms.link, tunnel->fwmark, 937 RT_TOS(tos), RT_SCOPE_UNIVERSE, IPPROTO_IPV6, 938 0, dst, tiph->saddr, 0, 0, 939 sock_net_uid(tunnel->net, NULL)); 940 941 rt = dst_cache_get_ip4(&tunnel->dst_cache, &fl4.saddr); 942 if (!rt) { 943 rt = ip_route_output_flow(tunnel->net, &fl4, NULL); 944 if (IS_ERR(rt)) { 945 DEV_STATS_INC(dev, tx_carrier_errors); 946 goto tx_error_icmp; 947 } 948 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, fl4.saddr); 949 } 950 951 if (rt->rt_type != RTN_UNICAST && rt->rt_type != RTN_LOCAL) { 952 ip_rt_put(rt); 953 DEV_STATS_INC(dev, tx_carrier_errors); 954 goto tx_error_icmp; 955 } 956 tdev = rt->dst.dev; 957 958 if (tdev == dev) { 959 ip_rt_put(rt); 960 DEV_STATS_INC(dev, collisions); 961 goto tx_error; 962 } 963 964 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) { 965 ip_rt_put(rt); 966 goto tx_error; 967 } 968 969 if (df) { 970 mtu = dst_mtu(&rt->dst) - t_hlen; 971 972 if (mtu < IPV4_MIN_MTU) { 973 DEV_STATS_INC(dev, collisions); 974 ip_rt_put(rt); 975 goto tx_error; 976 } 977 978 if (mtu < IPV6_MIN_MTU) { 979 mtu = IPV6_MIN_MTU; 980 df = 0; 981 } 982 983 if (tunnel->parms.iph.daddr) 984 skb_dst_update_pmtu_no_confirm(skb, mtu); 985 986 if (skb->len > mtu && !skb_is_gso(skb)) { 987 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 988 ip_rt_put(rt); 989 goto tx_error; 990 } 991 } 992 993 if (tunnel->err_count > 0) { 994 if (time_before(jiffies, 995 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 996 tunnel->err_count--; 997 dst_link_failure(skb); 998 } else 999 tunnel->err_count = 0; 1000 } 1001 1002 /* 1003 * Okay, now see if we can stuff it in the buffer as-is. 1004 */ 1005 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen; 1006 1007 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 1008 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 1009 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 1010 if (!new_skb) { 1011 ip_rt_put(rt); 1012 DEV_STATS_INC(dev, tx_dropped); 1013 kfree_skb(skb); 1014 return NETDEV_TX_OK; 1015 } 1016 if (skb->sk) 1017 skb_set_owner_w(new_skb, skb->sk); 1018 dev_kfree_skb(skb); 1019 skb = new_skb; 1020 iph6 = ipv6_hdr(skb); 1021 } 1022 ttl = tiph->ttl; 1023 if (ttl == 0) 1024 ttl = iph6->hop_limit; 1025 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 1026 1027 if (ip_tunnel_encap(skb, &tunnel->encap, &protocol, &fl4) < 0) { 1028 ip_rt_put(rt); 1029 goto tx_error; 1030 } 1031 1032 skb_set_inner_ipproto(skb, IPPROTO_IPV6); 1033 1034 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, 1035 df, !net_eq(tunnel->net, dev_net(dev))); 1036 return NETDEV_TX_OK; 1037 1038tx_error_icmp: 1039 dst_link_failure(skb); 1040tx_error: 1041 kfree_skb(skb); 1042 DEV_STATS_INC(dev, tx_errors); 1043 return NETDEV_TX_OK; 1044} 1045 1046static netdev_tx_t sit_tunnel_xmit__(struct sk_buff *skb, 1047 struct net_device *dev, u8 ipproto) 1048{ 1049 struct ip_tunnel *tunnel = netdev_priv(dev); 1050 const struct iphdr *tiph = &tunnel->parms.iph; 1051 1052 if (iptunnel_handle_offloads(skb, SKB_GSO_IPXIP4)) 1053 goto tx_error; 1054 1055 skb_set_inner_ipproto(skb, ipproto); 1056 1057 ip_tunnel_xmit(skb, dev, tiph, ipproto); 1058 return NETDEV_TX_OK; 1059tx_error: 1060 kfree_skb(skb); 1061 DEV_STATS_INC(dev, tx_errors); 1062 return NETDEV_TX_OK; 1063} 1064 1065static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, 1066 struct net_device *dev) 1067{ 1068 if (!pskb_inet_may_pull(skb)) 1069 goto tx_err; 1070 1071 switch (skb->protocol) { 1072 case htons(ETH_P_IP): 1073 sit_tunnel_xmit__(skb, dev, IPPROTO_IPIP); 1074 break; 1075 case htons(ETH_P_IPV6): 1076 ipip6_tunnel_xmit(skb, dev); 1077 break; 1078#if IS_ENABLED(CONFIG_MPLS) 1079 case htons(ETH_P_MPLS_UC): 1080 sit_tunnel_xmit__(skb, dev, IPPROTO_MPLS); 1081 break; 1082#endif 1083 default: 1084 goto tx_err; 1085 } 1086 1087 return NETDEV_TX_OK; 1088 1089tx_err: 1090 DEV_STATS_INC(dev, tx_errors); 1091 kfree_skb(skb); 1092 return NETDEV_TX_OK; 1093 1094} 1095 1096static void ipip6_tunnel_bind_dev(struct net_device *dev) 1097{ 1098 struct ip_tunnel *tunnel = netdev_priv(dev); 1099 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 1100 struct net_device *tdev = NULL; 1101 int hlen = LL_MAX_HEADER; 1102 const struct iphdr *iph; 1103 struct flowi4 fl4; 1104 1105 iph = &tunnel->parms.iph; 1106 1107 if (iph->daddr) { 1108 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, 1109 NULL, 1110 iph->daddr, iph->saddr, 1111 0, 0, 1112 IPPROTO_IPV6, 1113 RT_TOS(iph->tos), 1114 tunnel->parms.link); 1115 1116 if (!IS_ERR(rt)) { 1117 tdev = rt->dst.dev; 1118 ip_rt_put(rt); 1119 } 1120 dev->flags |= IFF_POINTOPOINT; 1121 } 1122 1123 if (!tdev && tunnel->parms.link) 1124 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 1125 1126 if (tdev && !netif_is_l3_master(tdev)) { 1127 int mtu; 1128 1129 mtu = tdev->mtu - t_hlen; 1130 if (mtu < IPV6_MIN_MTU) 1131 mtu = IPV6_MIN_MTU; 1132 WRITE_ONCE(dev->mtu, mtu); 1133 hlen = tdev->hard_header_len + tdev->needed_headroom; 1134 } 1135 dev->needed_headroom = t_hlen + hlen; 1136} 1137 1138static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p, 1139 __u32 fwmark) 1140{ 1141 struct net *net = t->net; 1142 struct sit_net *sitn = net_generic(net, sit_net_id); 1143 1144 ipip6_tunnel_unlink(sitn, t); 1145 synchronize_net(); 1146 t->parms.iph.saddr = p->iph.saddr; 1147 t->parms.iph.daddr = p->iph.daddr; 1148 __dev_addr_set(t->dev, &p->iph.saddr, 4); 1149 memcpy(t->dev->broadcast, &p->iph.daddr, 4); 1150 ipip6_tunnel_link(sitn, t); 1151 t->parms.iph.ttl = p->iph.ttl; 1152 t->parms.iph.tos = p->iph.tos; 1153 t->parms.iph.frag_off = p->iph.frag_off; 1154 if (t->parms.link != p->link || t->fwmark != fwmark) { 1155 t->parms.link = p->link; 1156 t->fwmark = fwmark; 1157 ipip6_tunnel_bind_dev(t->dev); 1158 } 1159 dst_cache_reset(&t->dst_cache); 1160 netdev_state_change(t->dev); 1161} 1162 1163#ifdef CONFIG_IPV6_SIT_6RD 1164static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, 1165 struct ip_tunnel_6rd *ip6rd) 1166{ 1167 struct in6_addr prefix; 1168 __be32 relay_prefix; 1169 1170 if (ip6rd->relay_prefixlen > 32 || 1171 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) 1172 return -EINVAL; 1173 1174 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); 1175 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) 1176 return -EINVAL; 1177 if (ip6rd->relay_prefixlen) 1178 relay_prefix = ip6rd->relay_prefix & 1179 htonl(0xffffffffUL << 1180 (32 - ip6rd->relay_prefixlen)); 1181 else 1182 relay_prefix = 0; 1183 if (relay_prefix != ip6rd->relay_prefix) 1184 return -EINVAL; 1185 1186 t->ip6rd.prefix = prefix; 1187 t->ip6rd.relay_prefix = relay_prefix; 1188 t->ip6rd.prefixlen = ip6rd->prefixlen; 1189 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; 1190 dst_cache_reset(&t->dst_cache); 1191 netdev_state_change(t->dev); 1192 return 0; 1193} 1194 1195static int 1196ipip6_tunnel_get6rd(struct net_device *dev, struct ip_tunnel_parm __user *data) 1197{ 1198 struct ip_tunnel *t = netdev_priv(dev); 1199 struct ip_tunnel_6rd ip6rd; 1200 struct ip_tunnel_parm p; 1201 1202 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) { 1203 if (copy_from_user(&p, data, sizeof(p))) 1204 return -EFAULT; 1205 t = ipip6_tunnel_locate(t->net, &p, 0); 1206 } 1207 if (!t) 1208 t = netdev_priv(dev); 1209 1210 ip6rd.prefix = t->ip6rd.prefix; 1211 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 1212 ip6rd.prefixlen = t->ip6rd.prefixlen; 1213 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 1214 if (copy_to_user(data, &ip6rd, sizeof(ip6rd))) 1215 return -EFAULT; 1216 return 0; 1217} 1218 1219static int 1220ipip6_tunnel_6rdctl(struct net_device *dev, struct ip_tunnel_6rd __user *data, 1221 int cmd) 1222{ 1223 struct ip_tunnel *t = netdev_priv(dev); 1224 struct ip_tunnel_6rd ip6rd; 1225 int err; 1226 1227 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN)) 1228 return -EPERM; 1229 if (copy_from_user(&ip6rd, data, sizeof(ip6rd))) 1230 return -EFAULT; 1231 1232 if (cmd != SIOCDEL6RD) { 1233 err = ipip6_tunnel_update_6rd(t, &ip6rd); 1234 if (err < 0) 1235 return err; 1236 } else 1237 ipip6_tunnel_clone_6rd(dev, dev_to_sit_net(dev)); 1238 return 0; 1239} 1240 1241#endif /* CONFIG_IPV6_SIT_6RD */ 1242 1243static bool ipip6_valid_ip_proto(u8 ipproto) 1244{ 1245 return ipproto == IPPROTO_IPV6 || 1246 ipproto == IPPROTO_IPIP || 1247#if IS_ENABLED(CONFIG_MPLS) 1248 ipproto == IPPROTO_MPLS || 1249#endif 1250 ipproto == 0; 1251} 1252 1253static int 1254__ipip6_tunnel_ioctl_validate(struct net *net, struct ip_tunnel_parm *p) 1255{ 1256 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1257 return -EPERM; 1258 1259 if (!ipip6_valid_ip_proto(p->iph.protocol)) 1260 return -EINVAL; 1261 if (p->iph.version != 4 || 1262 p->iph.ihl != 5 || (p->iph.frag_off & htons(~IP_DF))) 1263 return -EINVAL; 1264 1265 if (p->iph.ttl) 1266 p->iph.frag_off |= htons(IP_DF); 1267 return 0; 1268} 1269 1270static int 1271ipip6_tunnel_get(struct net_device *dev, struct ip_tunnel_parm *p) 1272{ 1273 struct ip_tunnel *t = netdev_priv(dev); 1274 1275 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) 1276 t = ipip6_tunnel_locate(t->net, p, 0); 1277 if (!t) 1278 t = netdev_priv(dev); 1279 memcpy(p, &t->parms, sizeof(*p)); 1280 return 0; 1281} 1282 1283static int 1284ipip6_tunnel_add(struct net_device *dev, struct ip_tunnel_parm *p) 1285{ 1286 struct ip_tunnel *t = netdev_priv(dev); 1287 int err; 1288 1289 err = __ipip6_tunnel_ioctl_validate(t->net, p); 1290 if (err) 1291 return err; 1292 1293 t = ipip6_tunnel_locate(t->net, p, 1); 1294 if (!t) 1295 return -ENOBUFS; 1296 return 0; 1297} 1298 1299static int 1300ipip6_tunnel_change(struct net_device *dev, struct ip_tunnel_parm *p) 1301{ 1302 struct ip_tunnel *t = netdev_priv(dev); 1303 int err; 1304 1305 err = __ipip6_tunnel_ioctl_validate(t->net, p); 1306 if (err) 1307 return err; 1308 1309 t = ipip6_tunnel_locate(t->net, p, 0); 1310 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) { 1311 if (!t) 1312 return -ENOENT; 1313 } else { 1314 if (t) { 1315 if (t->dev != dev) 1316 return -EEXIST; 1317 } else { 1318 if (((dev->flags & IFF_POINTOPOINT) && !p->iph.daddr) || 1319 (!(dev->flags & IFF_POINTOPOINT) && p->iph.daddr)) 1320 return -EINVAL; 1321 t = netdev_priv(dev); 1322 } 1323 1324 ipip6_tunnel_update(t, p, t->fwmark); 1325 } 1326 1327 return 0; 1328} 1329 1330static int 1331ipip6_tunnel_del(struct net_device *dev, struct ip_tunnel_parm *p) 1332{ 1333 struct ip_tunnel *t = netdev_priv(dev); 1334 1335 if (!ns_capable(t->net->user_ns, CAP_NET_ADMIN)) 1336 return -EPERM; 1337 1338 if (dev == dev_to_sit_net(dev)->fb_tunnel_dev) { 1339 t = ipip6_tunnel_locate(t->net, p, 0); 1340 if (!t) 1341 return -ENOENT; 1342 if (t == netdev_priv(dev_to_sit_net(dev)->fb_tunnel_dev)) 1343 return -EPERM; 1344 dev = t->dev; 1345 } 1346 unregister_netdevice(dev); 1347 return 0; 1348} 1349 1350static int 1351ipip6_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) 1352{ 1353 switch (cmd) { 1354 case SIOCGETTUNNEL: 1355 return ipip6_tunnel_get(dev, p); 1356 case SIOCADDTUNNEL: 1357 return ipip6_tunnel_add(dev, p); 1358 case SIOCCHGTUNNEL: 1359 return ipip6_tunnel_change(dev, p); 1360 case SIOCDELTUNNEL: 1361 return ipip6_tunnel_del(dev, p); 1362 default: 1363 return -EINVAL; 1364 } 1365} 1366 1367static int 1368ipip6_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 1369 void __user *data, int cmd) 1370{ 1371 switch (cmd) { 1372 case SIOCGETTUNNEL: 1373 case SIOCADDTUNNEL: 1374 case SIOCCHGTUNNEL: 1375 case SIOCDELTUNNEL: 1376 return ip_tunnel_siocdevprivate(dev, ifr, data, cmd); 1377 case SIOCGETPRL: 1378 return ipip6_tunnel_get_prl(dev, data); 1379 case SIOCADDPRL: 1380 case SIOCDELPRL: 1381 case SIOCCHGPRL: 1382 return ipip6_tunnel_prl_ctl(dev, data, cmd); 1383#ifdef CONFIG_IPV6_SIT_6RD 1384 case SIOCGET6RD: 1385 return ipip6_tunnel_get6rd(dev, data); 1386 case SIOCADD6RD: 1387 case SIOCCHG6RD: 1388 case SIOCDEL6RD: 1389 return ipip6_tunnel_6rdctl(dev, data, cmd); 1390#endif 1391 default: 1392 return -EINVAL; 1393 } 1394} 1395 1396static const struct net_device_ops ipip6_netdev_ops = { 1397 .ndo_init = ipip6_tunnel_init, 1398 .ndo_uninit = ipip6_tunnel_uninit, 1399 .ndo_start_xmit = sit_tunnel_xmit, 1400 .ndo_siocdevprivate = ipip6_tunnel_siocdevprivate, 1401 .ndo_get_iflink = ip_tunnel_get_iflink, 1402 .ndo_tunnel_ctl = ipip6_tunnel_ctl, 1403}; 1404 1405static void ipip6_dev_free(struct net_device *dev) 1406{ 1407 struct ip_tunnel *tunnel = netdev_priv(dev); 1408 1409 dst_cache_destroy(&tunnel->dst_cache); 1410} 1411 1412#define SIT_FEATURES (NETIF_F_SG | \ 1413 NETIF_F_FRAGLIST | \ 1414 NETIF_F_HIGHDMA | \ 1415 NETIF_F_GSO_SOFTWARE | \ 1416 NETIF_F_HW_CSUM) 1417 1418static void ipip6_tunnel_setup(struct net_device *dev) 1419{ 1420 struct ip_tunnel *tunnel = netdev_priv(dev); 1421 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 1422 1423 dev->netdev_ops = &ipip6_netdev_ops; 1424 dev->header_ops = &ip_tunnel_header_ops; 1425 dev->needs_free_netdev = true; 1426 dev->priv_destructor = ipip6_dev_free; 1427 1428 dev->type = ARPHRD_SIT; 1429 dev->mtu = ETH_DATA_LEN - t_hlen; 1430 dev->min_mtu = IPV6_MIN_MTU; 1431 dev->max_mtu = IP6_MAX_MTU - t_hlen; 1432 dev->flags = IFF_NOARP; 1433 netif_keep_dst(dev); 1434 dev->addr_len = 4; 1435 dev->features |= NETIF_F_LLTX; 1436 dev->features |= SIT_FEATURES; 1437 dev->hw_features |= SIT_FEATURES; 1438 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; 1439 1440} 1441 1442static int ipip6_tunnel_init(struct net_device *dev) 1443{ 1444 struct ip_tunnel *tunnel = netdev_priv(dev); 1445 int err; 1446 1447 tunnel->dev = dev; 1448 tunnel->net = dev_net(dev); 1449 strcpy(tunnel->parms.name, dev->name); 1450 1451 ipip6_tunnel_bind_dev(dev); 1452 1453 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); 1454 if (err) 1455 return err; 1456 1457 netdev_hold(dev, &tunnel->dev_tracker, GFP_KERNEL); 1458 netdev_lockdep_set_classes(dev); 1459 return 0; 1460} 1461 1462static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1463{ 1464 struct ip_tunnel *tunnel = netdev_priv(dev); 1465 struct iphdr *iph = &tunnel->parms.iph; 1466 struct net *net = dev_net(dev); 1467 struct sit_net *sitn = net_generic(net, sit_net_id); 1468 1469 iph->version = 4; 1470 iph->protocol = IPPROTO_IPV6; 1471 iph->ihl = 5; 1472 iph->ttl = 64; 1473 1474 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1475} 1476 1477static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[], 1478 struct netlink_ext_ack *extack) 1479{ 1480 u8 proto; 1481 1482 if (!data || !data[IFLA_IPTUN_PROTO]) 1483 return 0; 1484 1485 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1486 if (!ipip6_valid_ip_proto(proto)) 1487 return -EINVAL; 1488 1489 return 0; 1490} 1491 1492static void ipip6_netlink_parms(struct nlattr *data[], 1493 struct ip_tunnel_parm *parms, 1494 __u32 *fwmark) 1495{ 1496 memset(parms, 0, sizeof(*parms)); 1497 1498 parms->iph.version = 4; 1499 parms->iph.protocol = IPPROTO_IPV6; 1500 parms->iph.ihl = 5; 1501 parms->iph.ttl = 64; 1502 1503 if (!data) 1504 return; 1505 1506 ip_tunnel_netlink_parms(data, parms); 1507 1508 if (data[IFLA_IPTUN_FWMARK]) 1509 *fwmark = nla_get_u32(data[IFLA_IPTUN_FWMARK]); 1510} 1511 1512#ifdef CONFIG_IPV6_SIT_6RD 1513/* This function returns true when 6RD attributes are present in the nl msg */ 1514static bool ipip6_netlink_6rd_parms(struct nlattr *data[], 1515 struct ip_tunnel_6rd *ip6rd) 1516{ 1517 bool ret = false; 1518 memset(ip6rd, 0, sizeof(*ip6rd)); 1519 1520 if (!data) 1521 return ret; 1522 1523 if (data[IFLA_IPTUN_6RD_PREFIX]) { 1524 ret = true; 1525 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]); 1526 } 1527 1528 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { 1529 ret = true; 1530 ip6rd->relay_prefix = 1531 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); 1532 } 1533 1534 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { 1535 ret = true; 1536 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); 1537 } 1538 1539 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { 1540 ret = true; 1541 ip6rd->relay_prefixlen = 1542 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); 1543 } 1544 1545 return ret; 1546} 1547#endif 1548 1549static int ipip6_newlink(struct net *src_net, struct net_device *dev, 1550 struct nlattr *tb[], struct nlattr *data[], 1551 struct netlink_ext_ack *extack) 1552{ 1553 struct net *net = dev_net(dev); 1554 struct ip_tunnel *nt; 1555 struct ip_tunnel_encap ipencap; 1556#ifdef CONFIG_IPV6_SIT_6RD 1557 struct ip_tunnel_6rd ip6rd; 1558#endif 1559 int err; 1560 1561 nt = netdev_priv(dev); 1562 1563 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) { 1564 err = ip_tunnel_encap_setup(nt, &ipencap); 1565 if (err < 0) 1566 return err; 1567 } 1568 1569 ipip6_netlink_parms(data, &nt->parms, &nt->fwmark); 1570 1571 if (ipip6_tunnel_locate(net, &nt->parms, 0)) 1572 return -EEXIST; 1573 1574 err = ipip6_tunnel_create(dev); 1575 if (err < 0) 1576 return err; 1577 1578 if (tb[IFLA_MTU]) { 1579 u32 mtu = nla_get_u32(tb[IFLA_MTU]); 1580 1581 if (mtu >= IPV6_MIN_MTU && 1582 mtu <= IP6_MAX_MTU - dev->hard_header_len) 1583 dev->mtu = mtu; 1584 } 1585 1586#ifdef CONFIG_IPV6_SIT_6RD 1587 if (ipip6_netlink_6rd_parms(data, &ip6rd)) { 1588 err = ipip6_tunnel_update_6rd(nt, &ip6rd); 1589 if (err < 0) 1590 unregister_netdevice_queue(dev, NULL); 1591 } 1592#endif 1593 1594 return err; 1595} 1596 1597static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], 1598 struct nlattr *data[], 1599 struct netlink_ext_ack *extack) 1600{ 1601 struct ip_tunnel *t = netdev_priv(dev); 1602 struct ip_tunnel_parm p; 1603 struct ip_tunnel_encap ipencap; 1604 struct net *net = t->net; 1605 struct sit_net *sitn = net_generic(net, sit_net_id); 1606#ifdef CONFIG_IPV6_SIT_6RD 1607 struct ip_tunnel_6rd ip6rd; 1608#endif 1609 __u32 fwmark = t->fwmark; 1610 int err; 1611 1612 if (dev == sitn->fb_tunnel_dev) 1613 return -EINVAL; 1614 1615 if (ip_tunnel_netlink_encap_parms(data, &ipencap)) { 1616 err = ip_tunnel_encap_setup(t, &ipencap); 1617 if (err < 0) 1618 return err; 1619 } 1620 1621 ipip6_netlink_parms(data, &p, &fwmark); 1622 1623 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || 1624 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) 1625 return -EINVAL; 1626 1627 t = ipip6_tunnel_locate(net, &p, 0); 1628 1629 if (t) { 1630 if (t->dev != dev) 1631 return -EEXIST; 1632 } else 1633 t = netdev_priv(dev); 1634 1635 ipip6_tunnel_update(t, &p, fwmark); 1636 1637#ifdef CONFIG_IPV6_SIT_6RD 1638 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1639 return ipip6_tunnel_update_6rd(t, &ip6rd); 1640#endif 1641 1642 return 0; 1643} 1644 1645static size_t ipip6_get_size(const struct net_device *dev) 1646{ 1647 return 1648 /* IFLA_IPTUN_LINK */ 1649 nla_total_size(4) + 1650 /* IFLA_IPTUN_LOCAL */ 1651 nla_total_size(4) + 1652 /* IFLA_IPTUN_REMOTE */ 1653 nla_total_size(4) + 1654 /* IFLA_IPTUN_TTL */ 1655 nla_total_size(1) + 1656 /* IFLA_IPTUN_TOS */ 1657 nla_total_size(1) + 1658 /* IFLA_IPTUN_PMTUDISC */ 1659 nla_total_size(1) + 1660 /* IFLA_IPTUN_FLAGS */ 1661 nla_total_size(2) + 1662 /* IFLA_IPTUN_PROTO */ 1663 nla_total_size(1) + 1664#ifdef CONFIG_IPV6_SIT_6RD 1665 /* IFLA_IPTUN_6RD_PREFIX */ 1666 nla_total_size(sizeof(struct in6_addr)) + 1667 /* IFLA_IPTUN_6RD_RELAY_PREFIX */ 1668 nla_total_size(4) + 1669 /* IFLA_IPTUN_6RD_PREFIXLEN */ 1670 nla_total_size(2) + 1671 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ 1672 nla_total_size(2) + 1673#endif 1674 /* IFLA_IPTUN_ENCAP_TYPE */ 1675 nla_total_size(2) + 1676 /* IFLA_IPTUN_ENCAP_FLAGS */ 1677 nla_total_size(2) + 1678 /* IFLA_IPTUN_ENCAP_SPORT */ 1679 nla_total_size(2) + 1680 /* IFLA_IPTUN_ENCAP_DPORT */ 1681 nla_total_size(2) + 1682 /* IFLA_IPTUN_FWMARK */ 1683 nla_total_size(4) + 1684 0; 1685} 1686 1687static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1688{ 1689 struct ip_tunnel *tunnel = netdev_priv(dev); 1690 struct ip_tunnel_parm *parm = &tunnel->parms; 1691 1692 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1693 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || 1694 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || 1695 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || 1696 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || 1697 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, 1698 !!(parm->iph.frag_off & htons(IP_DF))) || 1699 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || 1700 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags) || 1701 nla_put_u32(skb, IFLA_IPTUN_FWMARK, tunnel->fwmark)) 1702 goto nla_put_failure; 1703 1704#ifdef CONFIG_IPV6_SIT_6RD 1705 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX, 1706 &tunnel->ip6rd.prefix) || 1707 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, 1708 tunnel->ip6rd.relay_prefix) || 1709 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, 1710 tunnel->ip6rd.prefixlen) || 1711 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, 1712 tunnel->ip6rd.relay_prefixlen)) 1713 goto nla_put_failure; 1714#endif 1715 1716 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, 1717 tunnel->encap.type) || 1718 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, 1719 tunnel->encap.sport) || 1720 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, 1721 tunnel->encap.dport) || 1722 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, 1723 tunnel->encap.flags)) 1724 goto nla_put_failure; 1725 1726 return 0; 1727 1728nla_put_failure: 1729 return -EMSGSIZE; 1730} 1731 1732static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { 1733 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1734 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, 1735 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, 1736 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1737 [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, 1738 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, 1739 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, 1740 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1741#ifdef CONFIG_IPV6_SIT_6RD 1742 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, 1743 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, 1744 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, 1745 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, 1746#endif 1747 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 }, 1748 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 }, 1749 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 }, 1750 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 }, 1751 [IFLA_IPTUN_FWMARK] = { .type = NLA_U32 }, 1752}; 1753 1754static void ipip6_dellink(struct net_device *dev, struct list_head *head) 1755{ 1756 struct net *net = dev_net(dev); 1757 struct sit_net *sitn = net_generic(net, sit_net_id); 1758 1759 if (dev != sitn->fb_tunnel_dev) 1760 unregister_netdevice_queue(dev, head); 1761} 1762 1763static struct rtnl_link_ops sit_link_ops __read_mostly = { 1764 .kind = "sit", 1765 .maxtype = IFLA_IPTUN_MAX, 1766 .policy = ipip6_policy, 1767 .priv_size = sizeof(struct ip_tunnel), 1768 .setup = ipip6_tunnel_setup, 1769 .validate = ipip6_validate, 1770 .newlink = ipip6_newlink, 1771 .changelink = ipip6_changelink, 1772 .get_size = ipip6_get_size, 1773 .fill_info = ipip6_fill_info, 1774 .dellink = ipip6_dellink, 1775 .get_link_net = ip_tunnel_get_link_net, 1776}; 1777 1778static struct xfrm_tunnel sit_handler __read_mostly = { 1779 .handler = ipip6_rcv, 1780 .err_handler = ipip6_err, 1781 .priority = 1, 1782}; 1783 1784static struct xfrm_tunnel ipip_handler __read_mostly = { 1785 .handler = ipip_rcv, 1786 .err_handler = ipip6_err, 1787 .priority = 2, 1788}; 1789 1790#if IS_ENABLED(CONFIG_MPLS) 1791static struct xfrm_tunnel mplsip_handler __read_mostly = { 1792 .handler = mplsip_rcv, 1793 .err_handler = ipip6_err, 1794 .priority = 2, 1795}; 1796#endif 1797 1798static void __net_exit sit_destroy_tunnels(struct net *net, 1799 struct list_head *head) 1800{ 1801 struct sit_net *sitn = net_generic(net, sit_net_id); 1802 struct net_device *dev, *aux; 1803 int prio; 1804 1805 for_each_netdev_safe(net, dev, aux) 1806 if (dev->rtnl_link_ops == &sit_link_ops) 1807 unregister_netdevice_queue(dev, head); 1808 1809 for (prio = 0; prio < 4; prio++) { 1810 int h; 1811 for (h = 0; h < (prio ? IP6_SIT_HASH_SIZE : 1); h++) { 1812 struct ip_tunnel *t; 1813 1814 t = rtnl_dereference(sitn->tunnels[prio][h]); 1815 while (t) { 1816 /* If dev is in the same netns, it has already 1817 * been added to the list by the previous loop. 1818 */ 1819 if (!net_eq(dev_net(t->dev), net)) 1820 unregister_netdevice_queue(t->dev, 1821 head); 1822 t = rtnl_dereference(t->next); 1823 } 1824 } 1825 } 1826} 1827 1828static int __net_init sit_init_net(struct net *net) 1829{ 1830 struct sit_net *sitn = net_generic(net, sit_net_id); 1831 struct ip_tunnel *t; 1832 int err; 1833 1834 sitn->tunnels[0] = sitn->tunnels_wc; 1835 sitn->tunnels[1] = sitn->tunnels_l; 1836 sitn->tunnels[2] = sitn->tunnels_r; 1837 sitn->tunnels[3] = sitn->tunnels_r_l; 1838 1839 if (!net_has_fallback_tunnels(net)) 1840 return 0; 1841 1842 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1843 NET_NAME_UNKNOWN, 1844 ipip6_tunnel_setup); 1845 if (!sitn->fb_tunnel_dev) { 1846 err = -ENOMEM; 1847 goto err_alloc_dev; 1848 } 1849 dev_net_set(sitn->fb_tunnel_dev, net); 1850 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; 1851 /* FB netdevice is special: we have one, and only one per netns. 1852 * Allowing to move it to another netns is clearly unsafe. 1853 */ 1854 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1855 1856 err = register_netdev(sitn->fb_tunnel_dev); 1857 if (err) 1858 goto err_reg_dev; 1859 1860 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1861 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1862 1863 t = netdev_priv(sitn->fb_tunnel_dev); 1864 1865 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1866 return 0; 1867 1868err_reg_dev: 1869 free_netdev(sitn->fb_tunnel_dev); 1870err_alloc_dev: 1871 return err; 1872} 1873 1874static void __net_exit sit_exit_batch_rtnl(struct list_head *net_list, 1875 struct list_head *dev_to_kill) 1876{ 1877 struct net *net; 1878 1879 ASSERT_RTNL(); 1880 list_for_each_entry(net, net_list, exit_list) 1881 sit_destroy_tunnels(net, dev_to_kill); 1882} 1883 1884static struct pernet_operations sit_net_ops = { 1885 .init = sit_init_net, 1886 .exit_batch_rtnl = sit_exit_batch_rtnl, 1887 .id = &sit_net_id, 1888 .size = sizeof(struct sit_net), 1889}; 1890 1891static void __exit sit_cleanup(void) 1892{ 1893 rtnl_link_unregister(&sit_link_ops); 1894 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1895 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1896#if IS_ENABLED(CONFIG_MPLS) 1897 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS); 1898#endif 1899 1900 unregister_pernet_device(&sit_net_ops); 1901 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1902} 1903 1904static int __init sit_init(void) 1905{ 1906 int err; 1907 1908 pr_info("IPv6, IPv4 and MPLS over IPv4 tunneling driver\n"); 1909 1910 err = register_pernet_device(&sit_net_ops); 1911 if (err < 0) 1912 return err; 1913 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1914 if (err < 0) { 1915 pr_info("%s: can't register ip6ip4\n", __func__); 1916 goto xfrm_tunnel_failed; 1917 } 1918 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 1919 if (err < 0) { 1920 pr_info("%s: can't register ip4ip4\n", __func__); 1921 goto xfrm_tunnel4_failed; 1922 } 1923#if IS_ENABLED(CONFIG_MPLS) 1924 err = xfrm4_tunnel_register(&mplsip_handler, AF_MPLS); 1925 if (err < 0) { 1926 pr_info("%s: can't register mplsip\n", __func__); 1927 goto xfrm_tunnel_mpls_failed; 1928 } 1929#endif 1930 err = rtnl_link_register(&sit_link_ops); 1931 if (err < 0) 1932 goto rtnl_link_failed; 1933 1934out: 1935 return err; 1936 1937rtnl_link_failed: 1938#if IS_ENABLED(CONFIG_MPLS) 1939 xfrm4_tunnel_deregister(&mplsip_handler, AF_MPLS); 1940xfrm_tunnel_mpls_failed: 1941#endif 1942 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1943xfrm_tunnel4_failed: 1944 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1945xfrm_tunnel_failed: 1946 unregister_pernet_device(&sit_net_ops); 1947 goto out; 1948} 1949 1950module_init(sit_init); 1951module_exit(sit_cleanup); 1952MODULE_DESCRIPTION("IPv6-in-IPv4 tunnel SIT driver"); 1953MODULE_LICENSE("GPL"); 1954MODULE_ALIAS_RTNL_LINK("sit"); 1955MODULE_ALIAS_NETDEV("sit0"); 1956