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 #include <linux/module.h> 21 #include <linux/capability.h> 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/socket.h> 25 #include <linux/sockios.h> 26 #include <linux/net.h> 27 #include <linux/in6.h> 28 #include <linux/netdevice.h> 29 #include <linux/if_arp.h> 30 #include <linux/icmp.h> 31 #include <linux/slab.h> 32 #include <asm/uaccess.h> 33 #include <linux/init.h> 34 #include <linux/netfilter_ipv4.h> 35 #include <linux/if_ether.h> 36 37 #include <net/sock.h> 38 #include <net/snmp.h> 39 40 #include <net/ipv6.h> 41 #include <net/protocol.h> 42 #include <net/transp_v6.h> 43 #include <net/ip6_fib.h> 44 #include <net/ip6_route.h> 45 #include <net/ndisc.h> 46 #include <net/addrconf.h> 47 #include <net/ip.h> 48 #include <net/udp.h> 49 #include <net/icmp.h> 50 #include <net/ipip.h> 51 #include <net/inet_ecn.h> 52 #include <net/xfrm.h> 53 #include <net/dsfield.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 57 /* 58 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 59 60 For comments look at net/ipv4/ip_gre.c --ANK 61 */ 62 63 #define HASH_SIZE 16 64 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 65 66 static int ipip6_tunnel_init(struct net_device *dev); 67 static void ipip6_tunnel_setup(struct net_device *dev); 68 static void ipip6_dev_free(struct net_device *dev); 69 70 static int sit_net_id __read_mostly; 71 struct sit_net { 72 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE]; 73 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE]; 74 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE]; 75 struct ip_tunnel __rcu *tunnels_wc[1]; 76 struct ip_tunnel __rcu **tunnels[4]; 77 78 struct net_device *fb_tunnel_dev; 79 }; 80 81 /* 82 * Locking : hash tables are protected by RCU and RTNL 83 */ 84 85 #define for_each_ip_tunnel_rcu(start) \ 86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 87 88 /* often modified stats are per cpu, other are shared (netdev->stats) */ 89 struct pcpu_tstats { 90 unsigned long rx_packets; 91 unsigned long rx_bytes; 92 unsigned long tx_packets; 93 unsigned long tx_bytes; 94 }; 95 96 static struct net_device_stats *ipip6_get_stats(struct net_device *dev) 97 { 98 struct pcpu_tstats sum = { 0 }; 99 int i; 100 101 for_each_possible_cpu(i) { 102 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 103 104 sum.rx_packets += tstats->rx_packets; 105 sum.rx_bytes += tstats->rx_bytes; 106 sum.tx_packets += tstats->tx_packets; 107 sum.tx_bytes += tstats->tx_bytes; 108 } 109 dev->stats.rx_packets = sum.rx_packets; 110 dev->stats.rx_bytes = sum.rx_bytes; 111 dev->stats.tx_packets = sum.tx_packets; 112 dev->stats.tx_bytes = sum.tx_bytes; 113 return &dev->stats; 114 } 115 /* 116 * Must be invoked with rcu_read_lock 117 */ 118 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, 119 struct net_device *dev, __be32 remote, __be32 local) 120 { 121 unsigned int h0 = HASH(remote); 122 unsigned int h1 = HASH(local); 123 struct ip_tunnel *t; 124 struct sit_net *sitn = net_generic(net, sit_net_id); 125 126 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) { 127 if (local == t->parms.iph.saddr && 128 remote == t->parms.iph.daddr && 129 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 130 (t->dev->flags & IFF_UP)) 131 return t; 132 } 133 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) { 134 if (remote == t->parms.iph.daddr && 135 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 136 (t->dev->flags & IFF_UP)) 137 return t; 138 } 139 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) { 140 if (local == t->parms.iph.saddr && 141 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 142 (t->dev->flags & IFF_UP)) 143 return t; 144 } 145 t = rcu_dereference(sitn->tunnels_wc[0]); 146 if ((t != NULL) && (t->dev->flags & IFF_UP)) 147 return t; 148 return NULL; 149 } 150 151 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn, 152 struct ip_tunnel_parm *parms) 153 { 154 __be32 remote = parms->iph.daddr; 155 __be32 local = parms->iph.saddr; 156 unsigned int h = 0; 157 int prio = 0; 158 159 if (remote) { 160 prio |= 2; 161 h ^= HASH(remote); 162 } 163 if (local) { 164 prio |= 1; 165 h ^= HASH(local); 166 } 167 return &sitn->tunnels[prio][h]; 168 } 169 170 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn, 171 struct ip_tunnel *t) 172 { 173 return __ipip6_bucket(sitn, &t->parms); 174 } 175 176 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 177 { 178 struct ip_tunnel __rcu **tp; 179 struct ip_tunnel *iter; 180 181 for (tp = ipip6_bucket(sitn, t); 182 (iter = rtnl_dereference(*tp)) != NULL; 183 tp = &iter->next) { 184 if (t == iter) { 185 rcu_assign_pointer(*tp, t->next); 186 break; 187 } 188 } 189 } 190 191 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 192 { 193 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t); 194 195 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 196 rcu_assign_pointer(*tp, t); 197 } 198 199 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 200 { 201 #ifdef CONFIG_IPV6_SIT_6RD 202 struct ip_tunnel *t = netdev_priv(dev); 203 204 if (t->dev == sitn->fb_tunnel_dev) { 205 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 206 t->ip6rd.relay_prefix = 0; 207 t->ip6rd.prefixlen = 16; 208 t->ip6rd.relay_prefixlen = 0; 209 } else { 210 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 211 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 212 } 213 #endif 214 } 215 216 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, 217 struct ip_tunnel_parm *parms, int create) 218 { 219 __be32 remote = parms->iph.daddr; 220 __be32 local = parms->iph.saddr; 221 struct ip_tunnel *t, *nt; 222 struct ip_tunnel __rcu **tp; 223 struct net_device *dev; 224 char name[IFNAMSIZ]; 225 struct sit_net *sitn = net_generic(net, sit_net_id); 226 227 for (tp = __ipip6_bucket(sitn, parms); 228 (t = rtnl_dereference(*tp)) != NULL; 229 tp = &t->next) { 230 if (local == t->parms.iph.saddr && 231 remote == t->parms.iph.daddr && 232 parms->link == t->parms.link) { 233 if (create) 234 return NULL; 235 else 236 return t; 237 } 238 } 239 if (!create) 240 goto failed; 241 242 if (parms->name[0]) 243 strlcpy(name, parms->name, IFNAMSIZ); 244 else 245 strcpy(name, "sit%d"); 246 247 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 248 if (dev == NULL) 249 return NULL; 250 251 dev_net_set(dev, net); 252 253 nt = netdev_priv(dev); 254 255 nt->parms = *parms; 256 if (ipip6_tunnel_init(dev) < 0) 257 goto failed_free; 258 ipip6_tunnel_clone_6rd(dev, sitn); 259 260 if (parms->i_flags & SIT_ISATAP) 261 dev->priv_flags |= IFF_ISATAP; 262 263 if (register_netdevice(dev) < 0) 264 goto failed_free; 265 266 dev_hold(dev); 267 268 ipip6_tunnel_link(sitn, nt); 269 return nt; 270 271 failed_free: 272 ipip6_dev_free(dev); 273 failed: 274 return NULL; 275 } 276 277 #define for_each_prl_rcu(start) \ 278 for (prl = rcu_dereference(start); \ 279 prl; \ 280 prl = rcu_dereference(prl->next)) 281 282 static struct ip_tunnel_prl_entry * 283 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 284 { 285 struct ip_tunnel_prl_entry *prl; 286 287 for_each_prl_rcu(t->prl) 288 if (prl->addr == addr) 289 break; 290 return prl; 291 292 } 293 294 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 295 struct ip_tunnel_prl __user *a) 296 { 297 struct ip_tunnel_prl kprl, *kp; 298 struct ip_tunnel_prl_entry *prl; 299 unsigned int cmax, c = 0, ca, len; 300 int ret = 0; 301 302 if (copy_from_user(&kprl, a, sizeof(kprl))) 303 return -EFAULT; 304 cmax = kprl.datalen / sizeof(kprl); 305 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 306 cmax = 1; 307 308 /* For simple GET or for root users, 309 * we try harder to allocate. 310 */ 311 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 312 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 313 NULL; 314 315 rcu_read_lock(); 316 317 ca = t->prl_count < cmax ? t->prl_count : cmax; 318 319 if (!kp) { 320 /* We don't try hard to allocate much memory for 321 * non-root users. 322 * For root users, retry allocating enough memory for 323 * the answer. 324 */ 325 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 326 if (!kp) { 327 ret = -ENOMEM; 328 goto out; 329 } 330 } 331 332 c = 0; 333 for_each_prl_rcu(t->prl) { 334 if (c >= cmax) 335 break; 336 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 337 continue; 338 kp[c].addr = prl->addr; 339 kp[c].flags = prl->flags; 340 c++; 341 if (kprl.addr != htonl(INADDR_ANY)) 342 break; 343 } 344 out: 345 rcu_read_unlock(); 346 347 len = sizeof(*kp) * c; 348 ret = 0; 349 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 350 ret = -EFAULT; 351 352 kfree(kp); 353 354 return ret; 355 } 356 357 static int 358 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 359 { 360 struct ip_tunnel_prl_entry *p; 361 int err = 0; 362 363 if (a->addr == htonl(INADDR_ANY)) 364 return -EINVAL; 365 366 ASSERT_RTNL(); 367 368 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) { 369 if (p->addr == a->addr) { 370 if (chg) { 371 p->flags = a->flags; 372 goto out; 373 } 374 err = -EEXIST; 375 goto out; 376 } 377 } 378 379 if (chg) { 380 err = -ENXIO; 381 goto out; 382 } 383 384 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 385 if (!p) { 386 err = -ENOBUFS; 387 goto out; 388 } 389 390 p->next = t->prl; 391 p->addr = a->addr; 392 p->flags = a->flags; 393 t->prl_count++; 394 rcu_assign_pointer(t->prl, p); 395 out: 396 return err; 397 } 398 399 static void prl_list_destroy_rcu(struct rcu_head *head) 400 { 401 struct ip_tunnel_prl_entry *p, *n; 402 403 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 404 do { 405 n = rcu_dereference_protected(p->next, 1); 406 kfree(p); 407 p = n; 408 } while (p); 409 } 410 411 static int 412 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 413 { 414 struct ip_tunnel_prl_entry *x; 415 struct ip_tunnel_prl_entry __rcu **p; 416 int err = 0; 417 418 ASSERT_RTNL(); 419 420 if (a && a->addr != htonl(INADDR_ANY)) { 421 for (p = &t->prl; 422 (x = rtnl_dereference(*p)) != NULL; 423 p = &x->next) { 424 if (x->addr == a->addr) { 425 *p = x->next; 426 kfree_rcu(x, rcu_head); 427 t->prl_count--; 428 goto out; 429 } 430 } 431 err = -ENXIO; 432 } else { 433 x = rtnl_dereference(t->prl); 434 if (x) { 435 t->prl_count = 0; 436 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 437 t->prl = NULL; 438 } 439 } 440 out: 441 return err; 442 } 443 444 static int 445 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t) 446 { 447 struct ip_tunnel_prl_entry *p; 448 int ok = 1; 449 450 rcu_read_lock(); 451 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 452 if (p) { 453 if (p->flags & PRL_DEFAULT) 454 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 455 else 456 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 457 } else { 458 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 459 460 if (ipv6_addr_is_isatap(addr6) && 461 (addr6->s6_addr32[3] == iph->saddr) && 462 ipv6_chk_prefix(addr6, t->dev)) 463 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 464 else 465 ok = 0; 466 } 467 rcu_read_unlock(); 468 return ok; 469 } 470 471 static void ipip6_tunnel_uninit(struct net_device *dev) 472 { 473 struct net *net = dev_net(dev); 474 struct sit_net *sitn = net_generic(net, sit_net_id); 475 476 if (dev == sitn->fb_tunnel_dev) { 477 rcu_assign_pointer(sitn->tunnels_wc[0], NULL); 478 } else { 479 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 480 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 481 } 482 dev_put(dev); 483 } 484 485 486 static int ipip6_err(struct sk_buff *skb, u32 info) 487 { 488 489 /* All the routers (except for Linux) return only 490 8 bytes of packet payload. It means, that precise relaying of 491 ICMP in the real Internet is absolutely infeasible. 492 */ 493 const struct iphdr *iph = (const struct iphdr *)skb->data; 494 const int type = icmp_hdr(skb)->type; 495 const int code = icmp_hdr(skb)->code; 496 struct ip_tunnel *t; 497 int err; 498 499 switch (type) { 500 default: 501 case ICMP_PARAMETERPROB: 502 return 0; 503 504 case ICMP_DEST_UNREACH: 505 switch (code) { 506 case ICMP_SR_FAILED: 507 case ICMP_PORT_UNREACH: 508 /* Impossible event. */ 509 return 0; 510 case ICMP_FRAG_NEEDED: 511 /* Soft state for pmtu is maintained by IP core. */ 512 return 0; 513 default: 514 /* All others are translated to HOST_UNREACH. 515 rfc2003 contains "deep thoughts" about NET_UNREACH, 516 I believe they are just ether pollution. --ANK 517 */ 518 break; 519 } 520 break; 521 case ICMP_TIME_EXCEEDED: 522 if (code != ICMP_EXC_TTL) 523 return 0; 524 break; 525 } 526 527 err = -ENOENT; 528 529 rcu_read_lock(); 530 t = ipip6_tunnel_lookup(dev_net(skb->dev), 531 skb->dev, 532 iph->daddr, 533 iph->saddr); 534 if (t == NULL || t->parms.iph.daddr == 0) 535 goto out; 536 537 err = 0; 538 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 539 goto out; 540 541 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 542 t->err_count++; 543 else 544 t->err_count = 1; 545 t->err_time = jiffies; 546 out: 547 rcu_read_unlock(); 548 return err; 549 } 550 551 static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb) 552 { 553 if (INET_ECN_is_ce(iph->tos)) 554 IP6_ECN_set_ce(ipv6_hdr(skb)); 555 } 556 557 static int ipip6_rcv(struct sk_buff *skb) 558 { 559 const struct iphdr *iph; 560 struct ip_tunnel *tunnel; 561 562 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 563 goto out; 564 565 iph = ip_hdr(skb); 566 567 rcu_read_lock(); 568 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 569 iph->saddr, iph->daddr); 570 if (tunnel != NULL) { 571 struct pcpu_tstats *tstats; 572 573 secpath_reset(skb); 574 skb->mac_header = skb->network_header; 575 skb_reset_network_header(skb); 576 IPCB(skb)->flags = 0; 577 skb->protocol = htons(ETH_P_IPV6); 578 skb->pkt_type = PACKET_HOST; 579 580 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 581 !isatap_chksrc(skb, iph, tunnel)) { 582 tunnel->dev->stats.rx_errors++; 583 rcu_read_unlock(); 584 kfree_skb(skb); 585 return 0; 586 } 587 588 tstats = this_cpu_ptr(tunnel->dev->tstats); 589 tstats->rx_packets++; 590 tstats->rx_bytes += skb->len; 591 592 __skb_tunnel_rx(skb, tunnel->dev); 593 594 ipip6_ecn_decapsulate(iph, skb); 595 596 netif_rx(skb); 597 598 rcu_read_unlock(); 599 return 0; 600 } 601 602 /* no tunnel matched, let upstream know, ipsec may handle it */ 603 rcu_read_unlock(); 604 return 1; 605 out: 606 kfree_skb(skb); 607 return 0; 608 } 609 610 /* 611 * Returns the embedded IPv4 address if the IPv6 address 612 * comes from 6rd / 6to4 (RFC 3056) addr space. 613 */ 614 static inline 615 __be32 try_6rd(const struct in6_addr *v6dst, struct ip_tunnel *tunnel) 616 { 617 __be32 dst = 0; 618 619 #ifdef CONFIG_IPV6_SIT_6RD 620 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 621 tunnel->ip6rd.prefixlen)) { 622 unsigned int pbw0, pbi0; 623 int pbi1; 624 u32 d; 625 626 pbw0 = tunnel->ip6rd.prefixlen >> 5; 627 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 628 629 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 630 tunnel->ip6rd.relay_prefixlen; 631 632 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 633 if (pbi1 > 0) 634 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 635 (32 - pbi1); 636 637 dst = tunnel->ip6rd.relay_prefix | htonl(d); 638 } 639 #else 640 if (v6dst->s6_addr16[0] == htons(0x2002)) { 641 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 642 memcpy(&dst, &v6dst->s6_addr16[1], 4); 643 } 644 #endif 645 return dst; 646 } 647 648 /* 649 * This function assumes it is being called from dev_queue_xmit() 650 * and that skb is filled properly by that function. 651 */ 652 653 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 654 struct net_device *dev) 655 { 656 struct ip_tunnel *tunnel = netdev_priv(dev); 657 struct pcpu_tstats *tstats; 658 const struct iphdr *tiph = &tunnel->parms.iph; 659 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 660 u8 tos = tunnel->parms.iph.tos; 661 __be16 df = tiph->frag_off; 662 struct rtable *rt; /* Route to the other host */ 663 struct net_device *tdev; /* Device to other host */ 664 struct iphdr *iph; /* Our new IP header */ 665 unsigned int max_headroom; /* The extra header space needed */ 666 __be32 dst = tiph->daddr; 667 struct flowi4 fl4; 668 int mtu; 669 const struct in6_addr *addr6; 670 int addr_type; 671 672 if (skb->protocol != htons(ETH_P_IPV6)) 673 goto tx_error; 674 675 /* ISATAP (RFC4214) - must come before 6to4 */ 676 if (dev->priv_flags & IFF_ISATAP) { 677 struct neighbour *neigh = NULL; 678 679 if (skb_dst(skb)) 680 neigh = skb_dst(skb)->neighbour; 681 682 if (neigh == NULL) { 683 if (net_ratelimit()) 684 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 685 goto tx_error; 686 } 687 688 addr6 = (const struct in6_addr*)&neigh->primary_key; 689 addr_type = ipv6_addr_type(addr6); 690 691 if ((addr_type & IPV6_ADDR_UNICAST) && 692 ipv6_addr_is_isatap(addr6)) 693 dst = addr6->s6_addr32[3]; 694 else 695 goto tx_error; 696 } 697 698 if (!dst) 699 dst = try_6rd(&iph6->daddr, tunnel); 700 701 if (!dst) { 702 struct neighbour *neigh = NULL; 703 704 if (skb_dst(skb)) 705 neigh = skb_dst(skb)->neighbour; 706 707 if (neigh == NULL) { 708 if (net_ratelimit()) 709 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 710 goto tx_error; 711 } 712 713 addr6 = (const struct in6_addr*)&neigh->primary_key; 714 addr_type = ipv6_addr_type(addr6); 715 716 if (addr_type == IPV6_ADDR_ANY) { 717 addr6 = &ipv6_hdr(skb)->daddr; 718 addr_type = ipv6_addr_type(addr6); 719 } 720 721 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 722 goto tx_error_icmp; 723 724 dst = addr6->s6_addr32[3]; 725 } 726 727 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 728 dst, tiph->saddr, 729 0, 0, 730 IPPROTO_IPV6, RT_TOS(tos), 731 tunnel->parms.link); 732 if (IS_ERR(rt)) { 733 dev->stats.tx_carrier_errors++; 734 goto tx_error_icmp; 735 } 736 if (rt->rt_type != RTN_UNICAST) { 737 ip_rt_put(rt); 738 dev->stats.tx_carrier_errors++; 739 goto tx_error_icmp; 740 } 741 tdev = rt->dst.dev; 742 743 if (tdev == dev) { 744 ip_rt_put(rt); 745 dev->stats.collisions++; 746 goto tx_error; 747 } 748 749 if (df) { 750 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 751 752 if (mtu < 68) { 753 dev->stats.collisions++; 754 ip_rt_put(rt); 755 goto tx_error; 756 } 757 758 if (mtu < IPV6_MIN_MTU) { 759 mtu = IPV6_MIN_MTU; 760 df = 0; 761 } 762 763 if (tunnel->parms.iph.daddr && skb_dst(skb)) 764 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 765 766 if (skb->len > mtu) { 767 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 768 ip_rt_put(rt); 769 goto tx_error; 770 } 771 } 772 773 if (tunnel->err_count > 0) { 774 if (time_before(jiffies, 775 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 776 tunnel->err_count--; 777 dst_link_failure(skb); 778 } else 779 tunnel->err_count = 0; 780 } 781 782 /* 783 * Okay, now see if we can stuff it in the buffer as-is. 784 */ 785 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 786 787 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 788 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 789 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 790 if (!new_skb) { 791 ip_rt_put(rt); 792 dev->stats.tx_dropped++; 793 dev_kfree_skb(skb); 794 return NETDEV_TX_OK; 795 } 796 if (skb->sk) 797 skb_set_owner_w(new_skb, skb->sk); 798 dev_kfree_skb(skb); 799 skb = new_skb; 800 iph6 = ipv6_hdr(skb); 801 } 802 803 skb->transport_header = skb->network_header; 804 skb_push(skb, sizeof(struct iphdr)); 805 skb_reset_network_header(skb); 806 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 807 IPCB(skb)->flags = 0; 808 skb_dst_drop(skb); 809 skb_dst_set(skb, &rt->dst); 810 811 /* 812 * Push down and install the IPIP header. 813 */ 814 815 iph = ip_hdr(skb); 816 iph->version = 4; 817 iph->ihl = sizeof(struct iphdr)>>2; 818 iph->frag_off = df; 819 iph->protocol = IPPROTO_IPV6; 820 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 821 iph->daddr = fl4.daddr; 822 iph->saddr = fl4.saddr; 823 824 if ((iph->ttl = tiph->ttl) == 0) 825 iph->ttl = iph6->hop_limit; 826 827 nf_reset(skb); 828 tstats = this_cpu_ptr(dev->tstats); 829 __IPTUNNEL_XMIT(tstats, &dev->stats); 830 return NETDEV_TX_OK; 831 832 tx_error_icmp: 833 dst_link_failure(skb); 834 tx_error: 835 dev->stats.tx_errors++; 836 dev_kfree_skb(skb); 837 return NETDEV_TX_OK; 838 } 839 840 static void ipip6_tunnel_bind_dev(struct net_device *dev) 841 { 842 struct net_device *tdev = NULL; 843 struct ip_tunnel *tunnel; 844 const struct iphdr *iph; 845 struct flowi4 fl4; 846 847 tunnel = netdev_priv(dev); 848 iph = &tunnel->parms.iph; 849 850 if (iph->daddr) { 851 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 852 iph->daddr, iph->saddr, 853 0, 0, 854 IPPROTO_IPV6, 855 RT_TOS(iph->tos), 856 tunnel->parms.link); 857 858 if (!IS_ERR(rt)) { 859 tdev = rt->dst.dev; 860 ip_rt_put(rt); 861 } 862 dev->flags |= IFF_POINTOPOINT; 863 } 864 865 if (!tdev && tunnel->parms.link) 866 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 867 868 if (tdev) { 869 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 870 dev->mtu = tdev->mtu - sizeof(struct iphdr); 871 if (dev->mtu < IPV6_MIN_MTU) 872 dev->mtu = IPV6_MIN_MTU; 873 } 874 dev->iflink = tunnel->parms.link; 875 } 876 877 static int 878 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 879 { 880 int err = 0; 881 struct ip_tunnel_parm p; 882 struct ip_tunnel_prl prl; 883 struct ip_tunnel *t; 884 struct net *net = dev_net(dev); 885 struct sit_net *sitn = net_generic(net, sit_net_id); 886 #ifdef CONFIG_IPV6_SIT_6RD 887 struct ip_tunnel_6rd ip6rd; 888 #endif 889 890 switch (cmd) { 891 case SIOCGETTUNNEL: 892 #ifdef CONFIG_IPV6_SIT_6RD 893 case SIOCGET6RD: 894 #endif 895 t = NULL; 896 if (dev == sitn->fb_tunnel_dev) { 897 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 898 err = -EFAULT; 899 break; 900 } 901 t = ipip6_tunnel_locate(net, &p, 0); 902 } 903 if (t == NULL) 904 t = netdev_priv(dev); 905 906 err = -EFAULT; 907 if (cmd == SIOCGETTUNNEL) { 908 memcpy(&p, &t->parms, sizeof(p)); 909 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 910 sizeof(p))) 911 goto done; 912 #ifdef CONFIG_IPV6_SIT_6RD 913 } else { 914 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 915 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 916 ip6rd.prefixlen = t->ip6rd.prefixlen; 917 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 918 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 919 sizeof(ip6rd))) 920 goto done; 921 #endif 922 } 923 err = 0; 924 break; 925 926 case SIOCADDTUNNEL: 927 case SIOCCHGTUNNEL: 928 err = -EPERM; 929 if (!capable(CAP_NET_ADMIN)) 930 goto done; 931 932 err = -EFAULT; 933 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 934 goto done; 935 936 err = -EINVAL; 937 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 938 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 939 goto done; 940 if (p.iph.ttl) 941 p.iph.frag_off |= htons(IP_DF); 942 943 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 944 945 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 946 if (t != NULL) { 947 if (t->dev != dev) { 948 err = -EEXIST; 949 break; 950 } 951 } else { 952 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 953 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 954 err = -EINVAL; 955 break; 956 } 957 t = netdev_priv(dev); 958 ipip6_tunnel_unlink(sitn, t); 959 synchronize_net(); 960 t->parms.iph.saddr = p.iph.saddr; 961 t->parms.iph.daddr = p.iph.daddr; 962 memcpy(dev->dev_addr, &p.iph.saddr, 4); 963 memcpy(dev->broadcast, &p.iph.daddr, 4); 964 ipip6_tunnel_link(sitn, t); 965 netdev_state_change(dev); 966 } 967 } 968 969 if (t) { 970 err = 0; 971 if (cmd == SIOCCHGTUNNEL) { 972 t->parms.iph.ttl = p.iph.ttl; 973 t->parms.iph.tos = p.iph.tos; 974 if (t->parms.link != p.link) { 975 t->parms.link = p.link; 976 ipip6_tunnel_bind_dev(dev); 977 netdev_state_change(dev); 978 } 979 } 980 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 981 err = -EFAULT; 982 } else 983 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 984 break; 985 986 case SIOCDELTUNNEL: 987 err = -EPERM; 988 if (!capable(CAP_NET_ADMIN)) 989 goto done; 990 991 if (dev == sitn->fb_tunnel_dev) { 992 err = -EFAULT; 993 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 994 goto done; 995 err = -ENOENT; 996 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 997 goto done; 998 err = -EPERM; 999 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1000 goto done; 1001 dev = t->dev; 1002 } 1003 unregister_netdevice(dev); 1004 err = 0; 1005 break; 1006 1007 case SIOCGETPRL: 1008 err = -EINVAL; 1009 if (dev == sitn->fb_tunnel_dev) 1010 goto done; 1011 err = -ENOENT; 1012 if (!(t = netdev_priv(dev))) 1013 goto done; 1014 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1015 break; 1016 1017 case SIOCADDPRL: 1018 case SIOCDELPRL: 1019 case SIOCCHGPRL: 1020 err = -EPERM; 1021 if (!capable(CAP_NET_ADMIN)) 1022 goto done; 1023 err = -EINVAL; 1024 if (dev == sitn->fb_tunnel_dev) 1025 goto done; 1026 err = -EFAULT; 1027 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1028 goto done; 1029 err = -ENOENT; 1030 if (!(t = netdev_priv(dev))) 1031 goto done; 1032 1033 switch (cmd) { 1034 case SIOCDELPRL: 1035 err = ipip6_tunnel_del_prl(t, &prl); 1036 break; 1037 case SIOCADDPRL: 1038 case SIOCCHGPRL: 1039 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1040 break; 1041 } 1042 netdev_state_change(dev); 1043 break; 1044 1045 #ifdef CONFIG_IPV6_SIT_6RD 1046 case SIOCADD6RD: 1047 case SIOCCHG6RD: 1048 case SIOCDEL6RD: 1049 err = -EPERM; 1050 if (!capable(CAP_NET_ADMIN)) 1051 goto done; 1052 1053 err = -EFAULT; 1054 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1055 sizeof(ip6rd))) 1056 goto done; 1057 1058 t = netdev_priv(dev); 1059 1060 if (cmd != SIOCDEL6RD) { 1061 struct in6_addr prefix; 1062 __be32 relay_prefix; 1063 1064 err = -EINVAL; 1065 if (ip6rd.relay_prefixlen > 32 || 1066 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1067 goto done; 1068 1069 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1070 ip6rd.prefixlen); 1071 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1072 goto done; 1073 if (ip6rd.relay_prefixlen) 1074 relay_prefix = ip6rd.relay_prefix & 1075 htonl(0xffffffffUL << 1076 (32 - ip6rd.relay_prefixlen)); 1077 else 1078 relay_prefix = 0; 1079 if (relay_prefix != ip6rd.relay_prefix) 1080 goto done; 1081 1082 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1083 t->ip6rd.relay_prefix = relay_prefix; 1084 t->ip6rd.prefixlen = ip6rd.prefixlen; 1085 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1086 } else 1087 ipip6_tunnel_clone_6rd(dev, sitn); 1088 1089 err = 0; 1090 break; 1091 #endif 1092 1093 default: 1094 err = -EINVAL; 1095 } 1096 1097 done: 1098 return err; 1099 } 1100 1101 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1102 { 1103 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1104 return -EINVAL; 1105 dev->mtu = new_mtu; 1106 return 0; 1107 } 1108 1109 static const struct net_device_ops ipip6_netdev_ops = { 1110 .ndo_uninit = ipip6_tunnel_uninit, 1111 .ndo_start_xmit = ipip6_tunnel_xmit, 1112 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1113 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1114 .ndo_get_stats = ipip6_get_stats, 1115 }; 1116 1117 static void ipip6_dev_free(struct net_device *dev) 1118 { 1119 free_percpu(dev->tstats); 1120 free_netdev(dev); 1121 } 1122 1123 static void ipip6_tunnel_setup(struct net_device *dev) 1124 { 1125 dev->netdev_ops = &ipip6_netdev_ops; 1126 dev->destructor = ipip6_dev_free; 1127 1128 dev->type = ARPHRD_SIT; 1129 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1130 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1131 dev->flags = IFF_NOARP; 1132 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1133 dev->iflink = 0; 1134 dev->addr_len = 4; 1135 dev->features |= NETIF_F_NETNS_LOCAL; 1136 dev->features |= NETIF_F_LLTX; 1137 } 1138 1139 static int ipip6_tunnel_init(struct net_device *dev) 1140 { 1141 struct ip_tunnel *tunnel = netdev_priv(dev); 1142 1143 tunnel->dev = dev; 1144 strcpy(tunnel->parms.name, dev->name); 1145 1146 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1147 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1148 1149 ipip6_tunnel_bind_dev(dev); 1150 dev->tstats = alloc_percpu(struct pcpu_tstats); 1151 if (!dev->tstats) 1152 return -ENOMEM; 1153 1154 return 0; 1155 } 1156 1157 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1158 { 1159 struct ip_tunnel *tunnel = netdev_priv(dev); 1160 struct iphdr *iph = &tunnel->parms.iph; 1161 struct net *net = dev_net(dev); 1162 struct sit_net *sitn = net_generic(net, sit_net_id); 1163 1164 tunnel->dev = dev; 1165 strcpy(tunnel->parms.name, dev->name); 1166 1167 iph->version = 4; 1168 iph->protocol = IPPROTO_IPV6; 1169 iph->ihl = 5; 1170 iph->ttl = 64; 1171 1172 dev->tstats = alloc_percpu(struct pcpu_tstats); 1173 if (!dev->tstats) 1174 return -ENOMEM; 1175 dev_hold(dev); 1176 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1177 return 0; 1178 } 1179 1180 static struct xfrm_tunnel sit_handler __read_mostly = { 1181 .handler = ipip6_rcv, 1182 .err_handler = ipip6_err, 1183 .priority = 1, 1184 }; 1185 1186 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1187 { 1188 int prio; 1189 1190 for (prio = 1; prio < 4; prio++) { 1191 int h; 1192 for (h = 0; h < HASH_SIZE; h++) { 1193 struct ip_tunnel *t; 1194 1195 t = rtnl_dereference(sitn->tunnels[prio][h]); 1196 while (t != NULL) { 1197 unregister_netdevice_queue(t->dev, head); 1198 t = rtnl_dereference(t->next); 1199 } 1200 } 1201 } 1202 } 1203 1204 static int __net_init sit_init_net(struct net *net) 1205 { 1206 struct sit_net *sitn = net_generic(net, sit_net_id); 1207 int err; 1208 1209 sitn->tunnels[0] = sitn->tunnels_wc; 1210 sitn->tunnels[1] = sitn->tunnels_l; 1211 sitn->tunnels[2] = sitn->tunnels_r; 1212 sitn->tunnels[3] = sitn->tunnels_r_l; 1213 1214 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1215 ipip6_tunnel_setup); 1216 if (!sitn->fb_tunnel_dev) { 1217 err = -ENOMEM; 1218 goto err_alloc_dev; 1219 } 1220 dev_net_set(sitn->fb_tunnel_dev, net); 1221 1222 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1223 if (err) 1224 goto err_dev_free; 1225 1226 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1227 1228 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1229 goto err_reg_dev; 1230 1231 return 0; 1232 1233 err_reg_dev: 1234 dev_put(sitn->fb_tunnel_dev); 1235 err_dev_free: 1236 ipip6_dev_free(sitn->fb_tunnel_dev); 1237 err_alloc_dev: 1238 return err; 1239 } 1240 1241 static void __net_exit sit_exit_net(struct net *net) 1242 { 1243 struct sit_net *sitn = net_generic(net, sit_net_id); 1244 LIST_HEAD(list); 1245 1246 rtnl_lock(); 1247 sit_destroy_tunnels(sitn, &list); 1248 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1249 unregister_netdevice_many(&list); 1250 rtnl_unlock(); 1251 } 1252 1253 static struct pernet_operations sit_net_ops = { 1254 .init = sit_init_net, 1255 .exit = sit_exit_net, 1256 .id = &sit_net_id, 1257 .size = sizeof(struct sit_net), 1258 }; 1259 1260 static void __exit sit_cleanup(void) 1261 { 1262 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1263 1264 unregister_pernet_device(&sit_net_ops); 1265 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1266 } 1267 1268 static int __init sit_init(void) 1269 { 1270 int err; 1271 1272 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1273 1274 err = register_pernet_device(&sit_net_ops); 1275 if (err < 0) 1276 return err; 1277 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1278 if (err < 0) { 1279 unregister_pernet_device(&sit_net_ops); 1280 printk(KERN_INFO "sit init: Can't add protocol\n"); 1281 } 1282 return err; 1283 } 1284 1285 module_init(sit_init); 1286 module_exit(sit_cleanup); 1287 MODULE_LICENSE("GPL"); 1288 MODULE_ALIAS_NETDEV("sit0"); 1289