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 } __attribute__((aligned(4*sizeof(unsigned long)))); 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 strcpy(nt->parms.name, dev->name); 267 268 dev_hold(dev); 269 270 ipip6_tunnel_link(sitn, nt); 271 return nt; 272 273 failed_free: 274 ipip6_dev_free(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) : 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 net *net = dev_net(dev); 476 struct sit_net *sitn = net_generic(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, netdev_priv(dev)); 482 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 483 } 484 dev_put(dev); 485 } 486 487 488 static int ipip6_err(struct sk_buff *skb, u32 info) 489 { 490 491 /* All the routers (except for Linux) return only 492 8 bytes of packet payload. It means, that precise relaying of 493 ICMP in the real Internet is absolutely infeasible. 494 */ 495 const struct iphdr *iph = (const struct iphdr *)skb->data; 496 const int type = icmp_hdr(skb)->type; 497 const int code = icmp_hdr(skb)->code; 498 struct ip_tunnel *t; 499 int err; 500 501 switch (type) { 502 default: 503 case ICMP_PARAMETERPROB: 504 return 0; 505 506 case ICMP_DEST_UNREACH: 507 switch (code) { 508 case ICMP_SR_FAILED: 509 case ICMP_PORT_UNREACH: 510 /* Impossible event. */ 511 return 0; 512 case ICMP_FRAG_NEEDED: 513 /* Soft state for pmtu is maintained by IP core. */ 514 return 0; 515 default: 516 /* All others are translated to HOST_UNREACH. 517 rfc2003 contains "deep thoughts" about NET_UNREACH, 518 I believe they are just ether pollution. --ANK 519 */ 520 break; 521 } 522 break; 523 case ICMP_TIME_EXCEEDED: 524 if (code != ICMP_EXC_TTL) 525 return 0; 526 break; 527 } 528 529 err = -ENOENT; 530 531 rcu_read_lock(); 532 t = ipip6_tunnel_lookup(dev_net(skb->dev), 533 skb->dev, 534 iph->daddr, 535 iph->saddr); 536 if (t == NULL || t->parms.iph.daddr == 0) 537 goto out; 538 539 err = 0; 540 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 541 goto out; 542 543 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 544 t->err_count++; 545 else 546 t->err_count = 1; 547 t->err_time = jiffies; 548 out: 549 rcu_read_unlock(); 550 return err; 551 } 552 553 static inline void ipip6_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb) 554 { 555 if (INET_ECN_is_ce(iph->tos)) 556 IP6_ECN_set_ce(ipv6_hdr(skb)); 557 } 558 559 static int ipip6_rcv(struct sk_buff *skb) 560 { 561 const struct iphdr *iph; 562 struct ip_tunnel *tunnel; 563 564 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 565 goto out; 566 567 iph = ip_hdr(skb); 568 569 rcu_read_lock(); 570 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 571 iph->saddr, iph->daddr); 572 if (tunnel != NULL) { 573 struct pcpu_tstats *tstats; 574 575 secpath_reset(skb); 576 skb->mac_header = skb->network_header; 577 skb_reset_network_header(skb); 578 IPCB(skb)->flags = 0; 579 skb->protocol = htons(ETH_P_IPV6); 580 skb->pkt_type = PACKET_HOST; 581 582 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 583 !isatap_chksrc(skb, iph, tunnel)) { 584 tunnel->dev->stats.rx_errors++; 585 rcu_read_unlock(); 586 kfree_skb(skb); 587 return 0; 588 } 589 590 tstats = this_cpu_ptr(tunnel->dev->tstats); 591 tstats->rx_packets++; 592 tstats->rx_bytes += skb->len; 593 594 __skb_tunnel_rx(skb, tunnel->dev); 595 596 ipip6_ecn_decapsulate(iph, skb); 597 598 netif_rx(skb); 599 600 rcu_read_unlock(); 601 return 0; 602 } 603 604 /* no tunnel matched, let upstream know, ipsec may handle it */ 605 rcu_read_unlock(); 606 return 1; 607 out: 608 kfree_skb(skb); 609 return 0; 610 } 611 612 /* 613 * Returns the embedded IPv4 address if the IPv6 address 614 * comes from 6rd / 6to4 (RFC 3056) addr space. 615 */ 616 static inline 617 __be32 try_6rd(const struct in6_addr *v6dst, struct ip_tunnel *tunnel) 618 { 619 __be32 dst = 0; 620 621 #ifdef CONFIG_IPV6_SIT_6RD 622 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 623 tunnel->ip6rd.prefixlen)) { 624 unsigned int pbw0, pbi0; 625 int pbi1; 626 u32 d; 627 628 pbw0 = tunnel->ip6rd.prefixlen >> 5; 629 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 630 631 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 632 tunnel->ip6rd.relay_prefixlen; 633 634 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 635 if (pbi1 > 0) 636 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 637 (32 - pbi1); 638 639 dst = tunnel->ip6rd.relay_prefix | htonl(d); 640 } 641 #else 642 if (v6dst->s6_addr16[0] == htons(0x2002)) { 643 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 644 memcpy(&dst, &v6dst->s6_addr16[1], 4); 645 } 646 #endif 647 return dst; 648 } 649 650 /* 651 * This function assumes it is being called from dev_queue_xmit() 652 * and that skb is filled properly by that function. 653 */ 654 655 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 656 struct net_device *dev) 657 { 658 struct ip_tunnel *tunnel = netdev_priv(dev); 659 struct pcpu_tstats *tstats; 660 const struct iphdr *tiph = &tunnel->parms.iph; 661 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 662 u8 tos = tunnel->parms.iph.tos; 663 __be16 df = tiph->frag_off; 664 struct rtable *rt; /* Route to the other host */ 665 struct net_device *tdev; /* Device to other host */ 666 struct iphdr *iph; /* Our new IP header */ 667 unsigned int max_headroom; /* The extra header space needed */ 668 __be32 dst = tiph->daddr; 669 struct flowi4 fl4; 670 int mtu; 671 const struct in6_addr *addr6; 672 int addr_type; 673 674 if (skb->protocol != htons(ETH_P_IPV6)) 675 goto tx_error; 676 677 if (tos == 1) 678 tos = ipv6_get_dsfield(iph6); 679 680 /* ISATAP (RFC4214) - must come before 6to4 */ 681 if (dev->priv_flags & IFF_ISATAP) { 682 struct neighbour *neigh = NULL; 683 684 if (skb_dst(skb)) 685 neigh = dst_get_neighbour_noref(skb_dst(skb)); 686 687 if (neigh == NULL) { 688 if (net_ratelimit()) 689 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 690 goto tx_error; 691 } 692 693 addr6 = (const struct in6_addr*)&neigh->primary_key; 694 addr_type = ipv6_addr_type(addr6); 695 696 if ((addr_type & IPV6_ADDR_UNICAST) && 697 ipv6_addr_is_isatap(addr6)) 698 dst = addr6->s6_addr32[3]; 699 else 700 goto tx_error; 701 } 702 703 if (!dst) 704 dst = try_6rd(&iph6->daddr, tunnel); 705 706 if (!dst) { 707 struct neighbour *neigh = NULL; 708 709 if (skb_dst(skb)) 710 neigh = dst_get_neighbour_noref(skb_dst(skb)); 711 712 if (neigh == NULL) { 713 if (net_ratelimit()) 714 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 715 goto tx_error; 716 } 717 718 addr6 = (const struct in6_addr*)&neigh->primary_key; 719 addr_type = ipv6_addr_type(addr6); 720 721 if (addr_type == IPV6_ADDR_ANY) { 722 addr6 = &ipv6_hdr(skb)->daddr; 723 addr_type = ipv6_addr_type(addr6); 724 } 725 726 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 727 goto tx_error_icmp; 728 729 dst = addr6->s6_addr32[3]; 730 } 731 732 rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 733 dst, tiph->saddr, 734 0, 0, 735 IPPROTO_IPV6, RT_TOS(tos), 736 tunnel->parms.link); 737 if (IS_ERR(rt)) { 738 dev->stats.tx_carrier_errors++; 739 goto tx_error_icmp; 740 } 741 if (rt->rt_type != RTN_UNICAST) { 742 ip_rt_put(rt); 743 dev->stats.tx_carrier_errors++; 744 goto tx_error_icmp; 745 } 746 tdev = rt->dst.dev; 747 748 if (tdev == dev) { 749 ip_rt_put(rt); 750 dev->stats.collisions++; 751 goto tx_error; 752 } 753 754 if (df) { 755 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 756 757 if (mtu < 68) { 758 dev->stats.collisions++; 759 ip_rt_put(rt); 760 goto tx_error; 761 } 762 763 if (mtu < IPV6_MIN_MTU) { 764 mtu = IPV6_MIN_MTU; 765 df = 0; 766 } 767 768 if (tunnel->parms.iph.daddr && skb_dst(skb)) 769 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 770 771 if (skb->len > mtu) { 772 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 773 ip_rt_put(rt); 774 goto tx_error; 775 } 776 } 777 778 if (tunnel->err_count > 0) { 779 if (time_before(jiffies, 780 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 781 tunnel->err_count--; 782 dst_link_failure(skb); 783 } else 784 tunnel->err_count = 0; 785 } 786 787 /* 788 * Okay, now see if we can stuff it in the buffer as-is. 789 */ 790 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 791 792 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 793 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 794 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 795 if (!new_skb) { 796 ip_rt_put(rt); 797 dev->stats.tx_dropped++; 798 dev_kfree_skb(skb); 799 return NETDEV_TX_OK; 800 } 801 if (skb->sk) 802 skb_set_owner_w(new_skb, skb->sk); 803 dev_kfree_skb(skb); 804 skb = new_skb; 805 iph6 = ipv6_hdr(skb); 806 } 807 808 skb->transport_header = skb->network_header; 809 skb_push(skb, sizeof(struct iphdr)); 810 skb_reset_network_header(skb); 811 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 812 IPCB(skb)->flags = 0; 813 skb_dst_drop(skb); 814 skb_dst_set(skb, &rt->dst); 815 816 /* 817 * Push down and install the IPIP header. 818 */ 819 820 iph = ip_hdr(skb); 821 iph->version = 4; 822 iph->ihl = sizeof(struct iphdr)>>2; 823 iph->frag_off = df; 824 iph->protocol = IPPROTO_IPV6; 825 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 826 iph->daddr = fl4.daddr; 827 iph->saddr = fl4.saddr; 828 829 if ((iph->ttl = tiph->ttl) == 0) 830 iph->ttl = iph6->hop_limit; 831 832 nf_reset(skb); 833 tstats = this_cpu_ptr(dev->tstats); 834 __IPTUNNEL_XMIT(tstats, &dev->stats); 835 return NETDEV_TX_OK; 836 837 tx_error_icmp: 838 dst_link_failure(skb); 839 tx_error: 840 dev->stats.tx_errors++; 841 dev_kfree_skb(skb); 842 return NETDEV_TX_OK; 843 } 844 845 static void ipip6_tunnel_bind_dev(struct net_device *dev) 846 { 847 struct net_device *tdev = NULL; 848 struct ip_tunnel *tunnel; 849 const struct iphdr *iph; 850 struct flowi4 fl4; 851 852 tunnel = netdev_priv(dev); 853 iph = &tunnel->parms.iph; 854 855 if (iph->daddr) { 856 struct rtable *rt = ip_route_output_ports(dev_net(dev), &fl4, NULL, 857 iph->daddr, iph->saddr, 858 0, 0, 859 IPPROTO_IPV6, 860 RT_TOS(iph->tos), 861 tunnel->parms.link); 862 863 if (!IS_ERR(rt)) { 864 tdev = rt->dst.dev; 865 ip_rt_put(rt); 866 } 867 dev->flags |= IFF_POINTOPOINT; 868 } 869 870 if (!tdev && tunnel->parms.link) 871 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 872 873 if (tdev) { 874 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 875 dev->mtu = tdev->mtu - sizeof(struct iphdr); 876 if (dev->mtu < IPV6_MIN_MTU) 877 dev->mtu = IPV6_MIN_MTU; 878 } 879 dev->iflink = tunnel->parms.link; 880 } 881 882 static int 883 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 884 { 885 int err = 0; 886 struct ip_tunnel_parm p; 887 struct ip_tunnel_prl prl; 888 struct ip_tunnel *t; 889 struct net *net = dev_net(dev); 890 struct sit_net *sitn = net_generic(net, sit_net_id); 891 #ifdef CONFIG_IPV6_SIT_6RD 892 struct ip_tunnel_6rd ip6rd; 893 #endif 894 895 switch (cmd) { 896 case SIOCGETTUNNEL: 897 #ifdef CONFIG_IPV6_SIT_6RD 898 case SIOCGET6RD: 899 #endif 900 t = NULL; 901 if (dev == sitn->fb_tunnel_dev) { 902 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 903 err = -EFAULT; 904 break; 905 } 906 t = ipip6_tunnel_locate(net, &p, 0); 907 } 908 if (t == NULL) 909 t = netdev_priv(dev); 910 911 err = -EFAULT; 912 if (cmd == SIOCGETTUNNEL) { 913 memcpy(&p, &t->parms, sizeof(p)); 914 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 915 sizeof(p))) 916 goto done; 917 #ifdef CONFIG_IPV6_SIT_6RD 918 } else { 919 ip6rd.prefix = t->ip6rd.prefix; 920 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 921 ip6rd.prefixlen = t->ip6rd.prefixlen; 922 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 923 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 924 sizeof(ip6rd))) 925 goto done; 926 #endif 927 } 928 err = 0; 929 break; 930 931 case SIOCADDTUNNEL: 932 case SIOCCHGTUNNEL: 933 err = -EPERM; 934 if (!capable(CAP_NET_ADMIN)) 935 goto done; 936 937 err = -EFAULT; 938 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 939 goto done; 940 941 err = -EINVAL; 942 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 943 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 944 goto done; 945 if (p.iph.ttl) 946 p.iph.frag_off |= htons(IP_DF); 947 948 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 949 950 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 951 if (t != NULL) { 952 if (t->dev != dev) { 953 err = -EEXIST; 954 break; 955 } 956 } else { 957 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 958 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 959 err = -EINVAL; 960 break; 961 } 962 t = netdev_priv(dev); 963 ipip6_tunnel_unlink(sitn, t); 964 synchronize_net(); 965 t->parms.iph.saddr = p.iph.saddr; 966 t->parms.iph.daddr = p.iph.daddr; 967 memcpy(dev->dev_addr, &p.iph.saddr, 4); 968 memcpy(dev->broadcast, &p.iph.daddr, 4); 969 ipip6_tunnel_link(sitn, t); 970 netdev_state_change(dev); 971 } 972 } 973 974 if (t) { 975 err = 0; 976 if (cmd == SIOCCHGTUNNEL) { 977 t->parms.iph.ttl = p.iph.ttl; 978 t->parms.iph.tos = p.iph.tos; 979 if (t->parms.link != p.link) { 980 t->parms.link = p.link; 981 ipip6_tunnel_bind_dev(dev); 982 netdev_state_change(dev); 983 } 984 } 985 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 986 err = -EFAULT; 987 } else 988 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 989 break; 990 991 case SIOCDELTUNNEL: 992 err = -EPERM; 993 if (!capable(CAP_NET_ADMIN)) 994 goto done; 995 996 if (dev == sitn->fb_tunnel_dev) { 997 err = -EFAULT; 998 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 999 goto done; 1000 err = -ENOENT; 1001 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 1002 goto done; 1003 err = -EPERM; 1004 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1005 goto done; 1006 dev = t->dev; 1007 } 1008 unregister_netdevice(dev); 1009 err = 0; 1010 break; 1011 1012 case SIOCGETPRL: 1013 err = -EINVAL; 1014 if (dev == sitn->fb_tunnel_dev) 1015 goto done; 1016 err = -ENOENT; 1017 if (!(t = netdev_priv(dev))) 1018 goto done; 1019 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1020 break; 1021 1022 case SIOCADDPRL: 1023 case SIOCDELPRL: 1024 case SIOCCHGPRL: 1025 err = -EPERM; 1026 if (!capable(CAP_NET_ADMIN)) 1027 goto done; 1028 err = -EINVAL; 1029 if (dev == sitn->fb_tunnel_dev) 1030 goto done; 1031 err = -EFAULT; 1032 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1033 goto done; 1034 err = -ENOENT; 1035 if (!(t = netdev_priv(dev))) 1036 goto done; 1037 1038 switch (cmd) { 1039 case SIOCDELPRL: 1040 err = ipip6_tunnel_del_prl(t, &prl); 1041 break; 1042 case SIOCADDPRL: 1043 case SIOCCHGPRL: 1044 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1045 break; 1046 } 1047 netdev_state_change(dev); 1048 break; 1049 1050 #ifdef CONFIG_IPV6_SIT_6RD 1051 case SIOCADD6RD: 1052 case SIOCCHG6RD: 1053 case SIOCDEL6RD: 1054 err = -EPERM; 1055 if (!capable(CAP_NET_ADMIN)) 1056 goto done; 1057 1058 err = -EFAULT; 1059 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1060 sizeof(ip6rd))) 1061 goto done; 1062 1063 t = netdev_priv(dev); 1064 1065 if (cmd != SIOCDEL6RD) { 1066 struct in6_addr prefix; 1067 __be32 relay_prefix; 1068 1069 err = -EINVAL; 1070 if (ip6rd.relay_prefixlen > 32 || 1071 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1072 goto done; 1073 1074 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1075 ip6rd.prefixlen); 1076 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1077 goto done; 1078 if (ip6rd.relay_prefixlen) 1079 relay_prefix = ip6rd.relay_prefix & 1080 htonl(0xffffffffUL << 1081 (32 - ip6rd.relay_prefixlen)); 1082 else 1083 relay_prefix = 0; 1084 if (relay_prefix != ip6rd.relay_prefix) 1085 goto done; 1086 1087 t->ip6rd.prefix = prefix; 1088 t->ip6rd.relay_prefix = relay_prefix; 1089 t->ip6rd.prefixlen = ip6rd.prefixlen; 1090 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1091 } else 1092 ipip6_tunnel_clone_6rd(dev, sitn); 1093 1094 err = 0; 1095 break; 1096 #endif 1097 1098 default: 1099 err = -EINVAL; 1100 } 1101 1102 done: 1103 return err; 1104 } 1105 1106 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1107 { 1108 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1109 return -EINVAL; 1110 dev->mtu = new_mtu; 1111 return 0; 1112 } 1113 1114 static const struct net_device_ops ipip6_netdev_ops = { 1115 .ndo_uninit = ipip6_tunnel_uninit, 1116 .ndo_start_xmit = ipip6_tunnel_xmit, 1117 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1118 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1119 .ndo_get_stats = ipip6_get_stats, 1120 }; 1121 1122 static void ipip6_dev_free(struct net_device *dev) 1123 { 1124 free_percpu(dev->tstats); 1125 free_netdev(dev); 1126 } 1127 1128 static void ipip6_tunnel_setup(struct net_device *dev) 1129 { 1130 dev->netdev_ops = &ipip6_netdev_ops; 1131 dev->destructor = ipip6_dev_free; 1132 1133 dev->type = ARPHRD_SIT; 1134 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1135 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1136 dev->flags = IFF_NOARP; 1137 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1138 dev->iflink = 0; 1139 dev->addr_len = 4; 1140 dev->features |= NETIF_F_NETNS_LOCAL; 1141 dev->features |= NETIF_F_LLTX; 1142 } 1143 1144 static int ipip6_tunnel_init(struct net_device *dev) 1145 { 1146 struct ip_tunnel *tunnel = netdev_priv(dev); 1147 1148 tunnel->dev = dev; 1149 1150 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1151 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1152 1153 ipip6_tunnel_bind_dev(dev); 1154 dev->tstats = alloc_percpu(struct pcpu_tstats); 1155 if (!dev->tstats) 1156 return -ENOMEM; 1157 1158 return 0; 1159 } 1160 1161 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1162 { 1163 struct ip_tunnel *tunnel = netdev_priv(dev); 1164 struct iphdr *iph = &tunnel->parms.iph; 1165 struct net *net = dev_net(dev); 1166 struct sit_net *sitn = net_generic(net, sit_net_id); 1167 1168 tunnel->dev = dev; 1169 strcpy(tunnel->parms.name, dev->name); 1170 1171 iph->version = 4; 1172 iph->protocol = IPPROTO_IPV6; 1173 iph->ihl = 5; 1174 iph->ttl = 64; 1175 1176 dev->tstats = alloc_percpu(struct pcpu_tstats); 1177 if (!dev->tstats) 1178 return -ENOMEM; 1179 dev_hold(dev); 1180 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1181 return 0; 1182 } 1183 1184 static struct xfrm_tunnel sit_handler __read_mostly = { 1185 .handler = ipip6_rcv, 1186 .err_handler = ipip6_err, 1187 .priority = 1, 1188 }; 1189 1190 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1191 { 1192 int prio; 1193 1194 for (prio = 1; prio < 4; prio++) { 1195 int h; 1196 for (h = 0; h < HASH_SIZE; h++) { 1197 struct ip_tunnel *t; 1198 1199 t = rtnl_dereference(sitn->tunnels[prio][h]); 1200 while (t != NULL) { 1201 unregister_netdevice_queue(t->dev, head); 1202 t = rtnl_dereference(t->next); 1203 } 1204 } 1205 } 1206 } 1207 1208 static int __net_init sit_init_net(struct net *net) 1209 { 1210 struct sit_net *sitn = net_generic(net, sit_net_id); 1211 struct ip_tunnel *t; 1212 int err; 1213 1214 sitn->tunnels[0] = sitn->tunnels_wc; 1215 sitn->tunnels[1] = sitn->tunnels_l; 1216 sitn->tunnels[2] = sitn->tunnels_r; 1217 sitn->tunnels[3] = sitn->tunnels_r_l; 1218 1219 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1220 ipip6_tunnel_setup); 1221 if (!sitn->fb_tunnel_dev) { 1222 err = -ENOMEM; 1223 goto err_alloc_dev; 1224 } 1225 dev_net_set(sitn->fb_tunnel_dev, net); 1226 1227 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1228 if (err) 1229 goto err_dev_free; 1230 1231 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1232 1233 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1234 goto err_reg_dev; 1235 1236 t = netdev_priv(sitn->fb_tunnel_dev); 1237 1238 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1239 return 0; 1240 1241 err_reg_dev: 1242 dev_put(sitn->fb_tunnel_dev); 1243 err_dev_free: 1244 ipip6_dev_free(sitn->fb_tunnel_dev); 1245 err_alloc_dev: 1246 return err; 1247 } 1248 1249 static void __net_exit sit_exit_net(struct net *net) 1250 { 1251 struct sit_net *sitn = net_generic(net, sit_net_id); 1252 LIST_HEAD(list); 1253 1254 rtnl_lock(); 1255 sit_destroy_tunnels(sitn, &list); 1256 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1257 unregister_netdevice_many(&list); 1258 rtnl_unlock(); 1259 } 1260 1261 static struct pernet_operations sit_net_ops = { 1262 .init = sit_init_net, 1263 .exit = sit_exit_net, 1264 .id = &sit_net_id, 1265 .size = sizeof(struct sit_net), 1266 }; 1267 1268 static void __exit sit_cleanup(void) 1269 { 1270 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1271 1272 unregister_pernet_device(&sit_net_ops); 1273 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1274 } 1275 1276 static int __init sit_init(void) 1277 { 1278 int err; 1279 1280 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1281 1282 err = register_pernet_device(&sit_net_ops); 1283 if (err < 0) 1284 return err; 1285 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1286 if (err < 0) { 1287 unregister_pernet_device(&sit_net_ops); 1288 printk(KERN_INFO "sit init: Can't add protocol\n"); 1289 } 1290 return err; 1291 } 1292 1293 module_init(sit_init); 1294 module_exit(sit_cleanup); 1295 MODULE_LICENSE("GPL"); 1296 MODULE_ALIAS_NETDEV("sit0"); 1297