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 66static void ipip6_tunnel_init(struct net_device *dev); 67static void ipip6_tunnel_setup(struct net_device *dev); 68 69static int sit_net_id __read_mostly; 70struct sit_net { 71 struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 72 struct ip_tunnel *tunnels_r[HASH_SIZE]; 73 struct ip_tunnel *tunnels_l[HASH_SIZE]; 74 struct ip_tunnel *tunnels_wc[1]; 75 struct ip_tunnel **tunnels[4]; 76 77 struct net_device *fb_tunnel_dev; 78}; 79 80/* 81 * Locking : hash tables are protected by RCU and a spinlock 82 */ 83static DEFINE_SPINLOCK(ipip6_lock); 84 85#define for_each_ip_tunnel_rcu(start) \ 86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 87 88/* 89 * Must be invoked with rcu_read_lock 90 */ 91static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, 92 struct net_device *dev, __be32 remote, __be32 local) 93{ 94 unsigned h0 = HASH(remote); 95 unsigned h1 = HASH(local); 96 struct ip_tunnel *t; 97 struct sit_net *sitn = net_generic(net, sit_net_id); 98 99 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) { 100 if (local == t->parms.iph.saddr && 101 remote == t->parms.iph.daddr && 102 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 103 (t->dev->flags & IFF_UP)) 104 return t; 105 } 106 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) { 107 if (remote == t->parms.iph.daddr && 108 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 109 (t->dev->flags & IFF_UP)) 110 return t; 111 } 112 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) { 113 if (local == t->parms.iph.saddr && 114 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 115 (t->dev->flags & IFF_UP)) 116 return t; 117 } 118 t = rcu_dereference(sitn->tunnels_wc[0]); 119 if ((t != NULL) && (t->dev->flags & IFF_UP)) 120 return t; 121 return NULL; 122} 123 124static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn, 125 struct ip_tunnel_parm *parms) 126{ 127 __be32 remote = parms->iph.daddr; 128 __be32 local = parms->iph.saddr; 129 unsigned h = 0; 130 int prio = 0; 131 132 if (remote) { 133 prio |= 2; 134 h ^= HASH(remote); 135 } 136 if (local) { 137 prio |= 1; 138 h ^= HASH(local); 139 } 140 return &sitn->tunnels[prio][h]; 141} 142 143static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn, 144 struct ip_tunnel *t) 145{ 146 return __ipip6_bucket(sitn, &t->parms); 147} 148 149static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 150{ 151 struct ip_tunnel **tp; 152 153 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) { 154 if (t == *tp) { 155 spin_lock_bh(&ipip6_lock); 156 *tp = t->next; 157 spin_unlock_bh(&ipip6_lock); 158 break; 159 } 160 } 161} 162 163static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 164{ 165 struct ip_tunnel **tp = ipip6_bucket(sitn, t); 166 167 spin_lock_bh(&ipip6_lock); 168 t->next = *tp; 169 rcu_assign_pointer(*tp, t); 170 spin_unlock_bh(&ipip6_lock); 171} 172 173static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 174{ 175#ifdef CONFIG_IPV6_SIT_6RD 176 struct ip_tunnel *t = netdev_priv(dev); 177 178 if (t->dev == sitn->fb_tunnel_dev) { 179 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 180 t->ip6rd.relay_prefix = 0; 181 t->ip6rd.prefixlen = 16; 182 t->ip6rd.relay_prefixlen = 0; 183 } else { 184 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 185 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 186 } 187#endif 188} 189 190static struct ip_tunnel * ipip6_tunnel_locate(struct net *net, 191 struct ip_tunnel_parm *parms, int create) 192{ 193 __be32 remote = parms->iph.daddr; 194 __be32 local = parms->iph.saddr; 195 struct ip_tunnel *t, **tp, *nt; 196 struct net_device *dev; 197 char name[IFNAMSIZ]; 198 struct sit_net *sitn = net_generic(net, sit_net_id); 199 200 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) { 201 if (local == t->parms.iph.saddr && 202 remote == t->parms.iph.daddr && 203 parms->link == t->parms.link) { 204 if (create) 205 return NULL; 206 else 207 return t; 208 } 209 } 210 if (!create) 211 goto failed; 212 213 if (parms->name[0]) 214 strlcpy(name, parms->name, IFNAMSIZ); 215 else 216 sprintf(name, "sit%%d"); 217 218 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 219 if (dev == NULL) 220 return NULL; 221 222 dev_net_set(dev, net); 223 224 if (strchr(name, '%')) { 225 if (dev_alloc_name(dev, name) < 0) 226 goto failed_free; 227 } 228 229 nt = netdev_priv(dev); 230 231 nt->parms = *parms; 232 ipip6_tunnel_init(dev); 233 ipip6_tunnel_clone_6rd(dev, sitn); 234 235 if (parms->i_flags & SIT_ISATAP) 236 dev->priv_flags |= IFF_ISATAP; 237 238 if (register_netdevice(dev) < 0) 239 goto failed_free; 240 241 dev_hold(dev); 242 243 ipip6_tunnel_link(sitn, nt); 244 return nt; 245 246failed_free: 247 free_netdev(dev); 248failed: 249 return NULL; 250} 251 252#define for_each_prl_rcu(start) \ 253 for (prl = rcu_dereference(start); \ 254 prl; \ 255 prl = rcu_dereference(prl->next)) 256 257static struct ip_tunnel_prl_entry * 258__ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 259{ 260 struct ip_tunnel_prl_entry *prl; 261 262 for_each_prl_rcu(t->prl) 263 if (prl->addr == addr) 264 break; 265 return prl; 266 267} 268 269static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 270 struct ip_tunnel_prl __user *a) 271{ 272 struct ip_tunnel_prl kprl, *kp; 273 struct ip_tunnel_prl_entry *prl; 274 unsigned int cmax, c = 0, ca, len; 275 int ret = 0; 276 277 if (copy_from_user(&kprl, a, sizeof(kprl))) 278 return -EFAULT; 279 cmax = kprl.datalen / sizeof(kprl); 280 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 281 cmax = 1; 282 283 /* For simple GET or for root users, 284 * we try harder to allocate. 285 */ 286 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 287 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 288 NULL; 289 290 rcu_read_lock(); 291 292 ca = t->prl_count < cmax ? t->prl_count : cmax; 293 294 if (!kp) { 295 /* We don't try hard to allocate much memory for 296 * non-root users. 297 * For root users, retry allocating enough memory for 298 * the answer. 299 */ 300 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 301 if (!kp) { 302 ret = -ENOMEM; 303 goto out; 304 } 305 } 306 307 c = 0; 308 for_each_prl_rcu(t->prl) { 309 if (c >= cmax) 310 break; 311 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 312 continue; 313 kp[c].addr = prl->addr; 314 kp[c].flags = prl->flags; 315 c++; 316 if (kprl.addr != htonl(INADDR_ANY)) 317 break; 318 } 319out: 320 rcu_read_unlock(); 321 322 len = sizeof(*kp) * c; 323 ret = 0; 324 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 325 ret = -EFAULT; 326 327 kfree(kp); 328 329 return ret; 330} 331 332static int 333ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 334{ 335 struct ip_tunnel_prl_entry *p; 336 int err = 0; 337 338 if (a->addr == htonl(INADDR_ANY)) 339 return -EINVAL; 340 341 ASSERT_RTNL(); 342 343 for (p = t->prl; p; p = p->next) { 344 if (p->addr == a->addr) { 345 if (chg) { 346 p->flags = a->flags; 347 goto out; 348 } 349 err = -EEXIST; 350 goto out; 351 } 352 } 353 354 if (chg) { 355 err = -ENXIO; 356 goto out; 357 } 358 359 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 360 if (!p) { 361 err = -ENOBUFS; 362 goto out; 363 } 364 365 p->next = t->prl; 366 p->addr = a->addr; 367 p->flags = a->flags; 368 t->prl_count++; 369 rcu_assign_pointer(t->prl, p); 370out: 371 return err; 372} 373 374static void prl_entry_destroy_rcu(struct rcu_head *head) 375{ 376 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head)); 377} 378 379static void prl_list_destroy_rcu(struct rcu_head *head) 380{ 381 struct ip_tunnel_prl_entry *p, *n; 382 383 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 384 do { 385 n = p->next; 386 kfree(p); 387 p = n; 388 } while (p); 389} 390 391static int 392ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 393{ 394 struct ip_tunnel_prl_entry *x, **p; 395 int err = 0; 396 397 ASSERT_RTNL(); 398 399 if (a && a->addr != htonl(INADDR_ANY)) { 400 for (p = &t->prl; *p; p = &(*p)->next) { 401 if ((*p)->addr == a->addr) { 402 x = *p; 403 *p = x->next; 404 call_rcu(&x->rcu_head, prl_entry_destroy_rcu); 405 t->prl_count--; 406 goto out; 407 } 408 } 409 err = -ENXIO; 410 } else { 411 if (t->prl) { 412 t->prl_count = 0; 413 x = t->prl; 414 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 415 t->prl = NULL; 416 } 417 } 418out: 419 return err; 420} 421 422static int 423isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 424{ 425 struct ip_tunnel_prl_entry *p; 426 int ok = 1; 427 428 rcu_read_lock(); 429 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 430 if (p) { 431 if (p->flags & PRL_DEFAULT) 432 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 433 else 434 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 435 } else { 436 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 437 if (ipv6_addr_is_isatap(addr6) && 438 (addr6->s6_addr32[3] == iph->saddr) && 439 ipv6_chk_prefix(addr6, t->dev)) 440 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 441 else 442 ok = 0; 443 } 444 rcu_read_unlock(); 445 return ok; 446} 447 448static void ipip6_tunnel_uninit(struct net_device *dev) 449{ 450 struct net *net = dev_net(dev); 451 struct sit_net *sitn = net_generic(net, sit_net_id); 452 453 if (dev == sitn->fb_tunnel_dev) { 454 spin_lock_bh(&ipip6_lock); 455 sitn->tunnels_wc[0] = NULL; 456 spin_unlock_bh(&ipip6_lock); 457 dev_put(dev); 458 } else { 459 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 460 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 461 dev_put(dev); 462 } 463} 464 465 466static int ipip6_err(struct sk_buff *skb, u32 info) 467{ 468 469/* All the routers (except for Linux) return only 470 8 bytes of packet payload. It means, that precise relaying of 471 ICMP in the real Internet is absolutely infeasible. 472 */ 473 struct iphdr *iph = (struct iphdr*)skb->data; 474 const int type = icmp_hdr(skb)->type; 475 const int code = icmp_hdr(skb)->code; 476 struct ip_tunnel *t; 477 int err; 478 479 switch (type) { 480 default: 481 case ICMP_PARAMETERPROB: 482 return 0; 483 484 case ICMP_DEST_UNREACH: 485 switch (code) { 486 case ICMP_SR_FAILED: 487 case ICMP_PORT_UNREACH: 488 /* Impossible event. */ 489 return 0; 490 case ICMP_FRAG_NEEDED: 491 /* Soft state for pmtu is maintained by IP core. */ 492 return 0; 493 default: 494 /* All others are translated to HOST_UNREACH. 495 rfc2003 contains "deep thoughts" about NET_UNREACH, 496 I believe they are just ether pollution. --ANK 497 */ 498 break; 499 } 500 break; 501 case ICMP_TIME_EXCEEDED: 502 if (code != ICMP_EXC_TTL) 503 return 0; 504 break; 505 } 506 507 err = -ENOENT; 508 509 rcu_read_lock(); 510 t = ipip6_tunnel_lookup(dev_net(skb->dev), 511 skb->dev, 512 iph->daddr, 513 iph->saddr); 514 if (t == NULL || t->parms.iph.daddr == 0) 515 goto out; 516 517 err = 0; 518 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 519 goto out; 520 521 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 522 t->err_count++; 523 else 524 t->err_count = 1; 525 t->err_time = jiffies; 526out: 527 rcu_read_unlock(); 528 return err; 529} 530 531static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 532{ 533 if (INET_ECN_is_ce(iph->tos)) 534 IP6_ECN_set_ce(ipv6_hdr(skb)); 535} 536 537static int ipip6_rcv(struct sk_buff *skb) 538{ 539 struct iphdr *iph; 540 struct ip_tunnel *tunnel; 541 542 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 543 goto out; 544 545 iph = ip_hdr(skb); 546 547 rcu_read_lock(); 548 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 549 iph->saddr, iph->daddr); 550 if (tunnel != NULL) { 551 secpath_reset(skb); 552 skb->mac_header = skb->network_header; 553 skb_reset_network_header(skb); 554 IPCB(skb)->flags = 0; 555 skb->protocol = htons(ETH_P_IPV6); 556 skb->pkt_type = PACKET_HOST; 557 558 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 559 !isatap_chksrc(skb, iph, tunnel)) { 560 tunnel->dev->stats.rx_errors++; 561 rcu_read_unlock(); 562 kfree_skb(skb); 563 return 0; 564 } 565 566 skb_tunnel_rx(skb, tunnel->dev); 567 568 ipip6_ecn_decapsulate(iph, skb); 569 netif_rx(skb); 570 rcu_read_unlock(); 571 return 0; 572 } 573 574 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 575 rcu_read_unlock(); 576out: 577 kfree_skb(skb); 578 return 0; 579} 580 581/* 582 * Returns the embedded IPv4 address if the IPv6 address 583 * comes from 6rd / 6to4 (RFC 3056) addr space. 584 */ 585static inline 586__be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel) 587{ 588 __be32 dst = 0; 589 590#ifdef CONFIG_IPV6_SIT_6RD 591 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 592 tunnel->ip6rd.prefixlen)) { 593 unsigned pbw0, pbi0; 594 int pbi1; 595 u32 d; 596 597 pbw0 = tunnel->ip6rd.prefixlen >> 5; 598 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 599 600 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 601 tunnel->ip6rd.relay_prefixlen; 602 603 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 604 if (pbi1 > 0) 605 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 606 (32 - pbi1); 607 608 dst = tunnel->ip6rd.relay_prefix | htonl(d); 609 } 610#else 611 if (v6dst->s6_addr16[0] == htons(0x2002)) { 612 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 613 memcpy(&dst, &v6dst->s6_addr16[1], 4); 614 } 615#endif 616 return dst; 617} 618 619/* 620 * This function assumes it is being called from dev_queue_xmit() 621 * and that skb is filled properly by that function. 622 */ 623 624static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 625 struct net_device *dev) 626{ 627 struct ip_tunnel *tunnel = netdev_priv(dev); 628 struct net_device_stats *stats = &dev->stats; 629 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); 630 struct iphdr *tiph = &tunnel->parms.iph; 631 struct ipv6hdr *iph6 = ipv6_hdr(skb); 632 u8 tos = tunnel->parms.iph.tos; 633 __be16 df = tiph->frag_off; 634 struct rtable *rt; /* Route to the other host */ 635 struct net_device *tdev; /* Device to other host */ 636 struct iphdr *iph; /* Our new IP header */ 637 unsigned int max_headroom; /* The extra header space needed */ 638 __be32 dst = tiph->daddr; 639 int mtu; 640 struct in6_addr *addr6; 641 int addr_type; 642 643 if (skb->protocol != htons(ETH_P_IPV6)) 644 goto tx_error; 645 646 /* ISATAP (RFC4214) - must come before 6to4 */ 647 if (dev->priv_flags & IFF_ISATAP) { 648 struct neighbour *neigh = NULL; 649 650 if (skb_dst(skb)) 651 neigh = skb_dst(skb)->neighbour; 652 653 if (neigh == NULL) { 654 if (net_ratelimit()) 655 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 656 goto tx_error; 657 } 658 659 addr6 = (struct in6_addr*)&neigh->primary_key; 660 addr_type = ipv6_addr_type(addr6); 661 662 if ((addr_type & IPV6_ADDR_UNICAST) && 663 ipv6_addr_is_isatap(addr6)) 664 dst = addr6->s6_addr32[3]; 665 else 666 goto tx_error; 667 } 668 669 if (!dst) 670 dst = try_6rd(&iph6->daddr, tunnel); 671 672 if (!dst) { 673 struct neighbour *neigh = NULL; 674 675 if (skb_dst(skb)) 676 neigh = skb_dst(skb)->neighbour; 677 678 if (neigh == NULL) { 679 if (net_ratelimit()) 680 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 681 goto tx_error; 682 } 683 684 addr6 = (struct in6_addr*)&neigh->primary_key; 685 addr_type = ipv6_addr_type(addr6); 686 687 if (addr_type == IPV6_ADDR_ANY) { 688 addr6 = &ipv6_hdr(skb)->daddr; 689 addr_type = ipv6_addr_type(addr6); 690 } 691 692 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 693 goto tx_error_icmp; 694 695 dst = addr6->s6_addr32[3]; 696 } 697 698 { 699 struct flowi fl = { .nl_u = { .ip4_u = 700 { .daddr = dst, 701 .saddr = tiph->saddr, 702 .tos = RT_TOS(tos) } }, 703 .oif = tunnel->parms.link, 704 .proto = IPPROTO_IPV6 }; 705 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 706 stats->tx_carrier_errors++; 707 goto tx_error_icmp; 708 } 709 } 710 if (rt->rt_type != RTN_UNICAST) { 711 ip_rt_put(rt); 712 stats->tx_carrier_errors++; 713 goto tx_error_icmp; 714 } 715 tdev = rt->dst.dev; 716 717 if (tdev == dev) { 718 ip_rt_put(rt); 719 stats->collisions++; 720 goto tx_error; 721 } 722 723 if (df) { 724 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 725 726 if (mtu < 68) { 727 stats->collisions++; 728 ip_rt_put(rt); 729 goto tx_error; 730 } 731 732 if (mtu < IPV6_MIN_MTU) { 733 mtu = IPV6_MIN_MTU; 734 df = 0; 735 } 736 737 if (tunnel->parms.iph.daddr && skb_dst(skb)) 738 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 739 740 if (skb->len > mtu) { 741 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 742 ip_rt_put(rt); 743 goto tx_error; 744 } 745 } 746 747 if (tunnel->err_count > 0) { 748 if (time_before(jiffies, 749 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 750 tunnel->err_count--; 751 dst_link_failure(skb); 752 } else 753 tunnel->err_count = 0; 754 } 755 756 /* 757 * Okay, now see if we can stuff it in the buffer as-is. 758 */ 759 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 760 761 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 762 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 763 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 764 if (!new_skb) { 765 ip_rt_put(rt); 766 txq->tx_dropped++; 767 dev_kfree_skb(skb); 768 return NETDEV_TX_OK; 769 } 770 if (skb->sk) 771 skb_set_owner_w(new_skb, skb->sk); 772 dev_kfree_skb(skb); 773 skb = new_skb; 774 iph6 = ipv6_hdr(skb); 775 } 776 777 skb->transport_header = skb->network_header; 778 skb_push(skb, sizeof(struct iphdr)); 779 skb_reset_network_header(skb); 780 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 781 IPCB(skb)->flags = 0; 782 skb_dst_drop(skb); 783 skb_dst_set(skb, &rt->dst); 784 785 /* 786 * Push down and install the IPIP header. 787 */ 788 789 iph = ip_hdr(skb); 790 iph->version = 4; 791 iph->ihl = sizeof(struct iphdr)>>2; 792// iph->frag_off = df; 793 iph->frag_off = 0; 794 iph->protocol = IPPROTO_IPV6; 795 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 796 iph->daddr = rt->rt_dst; 797 iph->saddr = rt->rt_src; 798 799 if ((iph->ttl = tiph->ttl) == 0) 800 iph->ttl = iph6->hop_limit; 801 802 nf_reset(skb); 803 804 IPTUNNEL_XMIT(); 805 return NETDEV_TX_OK; 806 807tx_error_icmp: 808 dst_link_failure(skb); 809tx_error: 810 stats->tx_errors++; 811 dev_kfree_skb(skb); 812 return NETDEV_TX_OK; 813} 814 815static void ipip6_tunnel_bind_dev(struct net_device *dev) 816{ 817 struct net_device *tdev = NULL; 818 struct ip_tunnel *tunnel; 819 struct iphdr *iph; 820 821 tunnel = netdev_priv(dev); 822 iph = &tunnel->parms.iph; 823 824 if (iph->daddr) { 825 struct flowi fl = { .nl_u = { .ip4_u = 826 { .daddr = iph->daddr, 827 .saddr = iph->saddr, 828 .tos = RT_TOS(iph->tos) } }, 829 .oif = tunnel->parms.link, 830 .proto = IPPROTO_IPV6 }; 831 struct rtable *rt; 832 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 833 tdev = rt->dst.dev; 834 ip_rt_put(rt); 835 } 836 dev->flags |= IFF_POINTOPOINT; 837 } 838 839 if (!tdev && tunnel->parms.link) 840 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 841 842 if (tdev) { 843 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 844 dev->mtu = tdev->mtu - sizeof(struct iphdr); 845 if (dev->mtu < IPV6_MIN_MTU) 846 dev->mtu = IPV6_MIN_MTU; 847 } 848 dev->iflink = tunnel->parms.link; 849} 850 851static int 852ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 853{ 854 int err = 0; 855 struct ip_tunnel_parm p; 856 struct ip_tunnel_prl prl; 857 struct ip_tunnel *t; 858 struct net *net = dev_net(dev); 859 struct sit_net *sitn = net_generic(net, sit_net_id); 860#ifdef CONFIG_IPV6_SIT_6RD 861 struct ip_tunnel_6rd ip6rd; 862#endif 863 864 switch (cmd) { 865 case SIOCGETTUNNEL: 866#ifdef CONFIG_IPV6_SIT_6RD 867 case SIOCGET6RD: 868#endif 869 t = NULL; 870 if (dev == sitn->fb_tunnel_dev) { 871 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 872 err = -EFAULT; 873 break; 874 } 875 t = ipip6_tunnel_locate(net, &p, 0); 876 } 877 if (t == NULL) 878 t = netdev_priv(dev); 879 880 err = -EFAULT; 881 if (cmd == SIOCGETTUNNEL) { 882 memcpy(&p, &t->parms, sizeof(p)); 883 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 884 sizeof(p))) 885 goto done; 886#ifdef CONFIG_IPV6_SIT_6RD 887 } else { 888 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 889 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 890 ip6rd.prefixlen = t->ip6rd.prefixlen; 891 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 892 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 893 sizeof(ip6rd))) 894 goto done; 895#endif 896 } 897 err = 0; 898 break; 899 900 case SIOCADDTUNNEL: 901 case SIOCCHGTUNNEL: 902 err = -EPERM; 903 if (!capable(CAP_NET_ADMIN)) 904 goto done; 905 906 err = -EFAULT; 907 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 908 goto done; 909 910 err = -EINVAL; 911 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 912 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 913 goto done; 914 if (p.iph.ttl) 915 p.iph.frag_off |= htons(IP_DF); 916 917 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 918 919 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 920 if (t != NULL) { 921 if (t->dev != dev) { 922 err = -EEXIST; 923 break; 924 } 925 } else { 926 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 927 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 928 err = -EINVAL; 929 break; 930 } 931 t = netdev_priv(dev); 932 ipip6_tunnel_unlink(sitn, t); 933 t->parms.iph.saddr = p.iph.saddr; 934 t->parms.iph.daddr = p.iph.daddr; 935 memcpy(dev->dev_addr, &p.iph.saddr, 4); 936 memcpy(dev->broadcast, &p.iph.daddr, 4); 937 ipip6_tunnel_link(sitn, t); 938 netdev_state_change(dev); 939 } 940 } 941 942 if (t) { 943 err = 0; 944 if (cmd == SIOCCHGTUNNEL) { 945 t->parms.iph.ttl = p.iph.ttl; 946 t->parms.iph.tos = p.iph.tos; 947 if (t->parms.link != p.link) { 948 t->parms.link = p.link; 949 ipip6_tunnel_bind_dev(dev); 950 netdev_state_change(dev); 951 } 952 } 953 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 954 err = -EFAULT; 955 } else 956 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 957 break; 958 959 case SIOCDELTUNNEL: 960 err = -EPERM; 961 if (!capable(CAP_NET_ADMIN)) 962 goto done; 963 964 if (dev == sitn->fb_tunnel_dev) { 965 err = -EFAULT; 966 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 967 goto done; 968 err = -ENOENT; 969 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 970 goto done; 971 err = -EPERM; 972 if (t == netdev_priv(sitn->fb_tunnel_dev)) 973 goto done; 974 dev = t->dev; 975 } 976 unregister_netdevice(dev); 977 err = 0; 978 break; 979 980 case SIOCGETPRL: 981 err = -EINVAL; 982 if (dev == sitn->fb_tunnel_dev) 983 goto done; 984 err = -ENOENT; 985 if (!(t = netdev_priv(dev))) 986 goto done; 987 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 988 break; 989 990 case SIOCADDPRL: 991 case SIOCDELPRL: 992 case SIOCCHGPRL: 993 err = -EPERM; 994 if (!capable(CAP_NET_ADMIN)) 995 goto done; 996 err = -EINVAL; 997 if (dev == sitn->fb_tunnel_dev) 998 goto done; 999 err = -EFAULT; 1000 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1001 goto done; 1002 err = -ENOENT; 1003 if (!(t = netdev_priv(dev))) 1004 goto done; 1005 1006 switch (cmd) { 1007 case SIOCDELPRL: 1008 err = ipip6_tunnel_del_prl(t, &prl); 1009 break; 1010 case SIOCADDPRL: 1011 case SIOCCHGPRL: 1012 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1013 break; 1014 } 1015 netdev_state_change(dev); 1016 break; 1017 1018#ifdef CONFIG_IPV6_SIT_6RD 1019 case SIOCADD6RD: 1020 case SIOCCHG6RD: 1021 case SIOCDEL6RD: 1022 err = -EPERM; 1023 if (!capable(CAP_NET_ADMIN)) 1024 goto done; 1025 1026 err = -EFAULT; 1027 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1028 sizeof(ip6rd))) 1029 goto done; 1030 1031 t = netdev_priv(dev); 1032 1033 if (cmd != SIOCDEL6RD) { 1034 struct in6_addr prefix; 1035 __be32 relay_prefix; 1036 1037 err = -EINVAL; 1038 if (ip6rd.relay_prefixlen > 32 || 1039 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1040 goto done; 1041 1042 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1043 ip6rd.prefixlen); 1044 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1045 goto done; 1046 if (ip6rd.relay_prefixlen) 1047 relay_prefix = ip6rd.relay_prefix & 1048 htonl(0xffffffffUL << 1049 (32 - ip6rd.relay_prefixlen)); 1050 else 1051 relay_prefix = 0; 1052 if (relay_prefix != ip6rd.relay_prefix) 1053 goto done; 1054 1055 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1056 t->ip6rd.relay_prefix = relay_prefix; 1057 t->ip6rd.prefixlen = ip6rd.prefixlen; 1058 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1059 } else 1060 ipip6_tunnel_clone_6rd(dev, sitn); 1061 1062 err = 0; 1063 break; 1064#endif 1065 1066 default: 1067 err = -EINVAL; 1068 } 1069 1070done: 1071 return err; 1072} 1073 1074static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1075{ 1076 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1077 return -EINVAL; 1078 dev->mtu = new_mtu; 1079 return 0; 1080} 1081 1082static const struct net_device_ops ipip6_netdev_ops = { 1083 .ndo_uninit = ipip6_tunnel_uninit, 1084 .ndo_start_xmit = ipip6_tunnel_xmit, 1085 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1086 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1087}; 1088 1089static void ipip6_tunnel_setup(struct net_device *dev) 1090{ 1091 dev->netdev_ops = &ipip6_netdev_ops; 1092 dev->destructor = free_netdev; 1093 1094 dev->type = ARPHRD_SIT; 1095 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1096 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1097 dev->flags = IFF_NOARP; 1098 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1099 dev->iflink = 0; 1100 dev->addr_len = 4; 1101 dev->features |= NETIF_F_NETNS_LOCAL; 1102} 1103 1104static void ipip6_tunnel_init(struct net_device *dev) 1105{ 1106 struct ip_tunnel *tunnel = netdev_priv(dev); 1107 1108 tunnel->dev = dev; 1109 strcpy(tunnel->parms.name, dev->name); 1110 1111 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1112 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1113 1114 ipip6_tunnel_bind_dev(dev); 1115} 1116 1117static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1118{ 1119 struct ip_tunnel *tunnel = netdev_priv(dev); 1120 struct iphdr *iph = &tunnel->parms.iph; 1121 struct net *net = dev_net(dev); 1122 struct sit_net *sitn = net_generic(net, sit_net_id); 1123 1124 tunnel->dev = dev; 1125 strcpy(tunnel->parms.name, dev->name); 1126 1127 iph->version = 4; 1128 iph->protocol = IPPROTO_IPV6; 1129 iph->ihl = 5; 1130 iph->ttl = 64; 1131 1132 dev_hold(dev); 1133 sitn->tunnels_wc[0] = tunnel; 1134} 1135 1136static struct xfrm_tunnel sit_handler = { 1137 .handler = ipip6_rcv, 1138 .err_handler = ipip6_err, 1139 .priority = 1, 1140}; 1141 1142static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1143{ 1144 int prio; 1145 1146 for (prio = 1; prio < 4; prio++) { 1147 int h; 1148 for (h = 0; h < HASH_SIZE; h++) { 1149 struct ip_tunnel *t = sitn->tunnels[prio][h]; 1150 1151 while (t != NULL) { 1152 unregister_netdevice_queue(t->dev, head); 1153 t = t->next; 1154 } 1155 } 1156 } 1157} 1158 1159static int __net_init sit_init_net(struct net *net) 1160{ 1161 struct sit_net *sitn = net_generic(net, sit_net_id); 1162 int err; 1163 1164 sitn->tunnels[0] = sitn->tunnels_wc; 1165 sitn->tunnels[1] = sitn->tunnels_l; 1166 sitn->tunnels[2] = sitn->tunnels_r; 1167 sitn->tunnels[3] = sitn->tunnels_r_l; 1168 1169 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1170 ipip6_tunnel_setup); 1171 if (!sitn->fb_tunnel_dev) { 1172 err = -ENOMEM; 1173 goto err_alloc_dev; 1174 } 1175 dev_net_set(sitn->fb_tunnel_dev, net); 1176 1177 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1178 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1179 1180 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1181 goto err_reg_dev; 1182 1183 return 0; 1184 1185err_reg_dev: 1186 dev_put(sitn->fb_tunnel_dev); 1187 free_netdev(sitn->fb_tunnel_dev); 1188err_alloc_dev: 1189 return err; 1190} 1191 1192static void __net_exit sit_exit_net(struct net *net) 1193{ 1194 struct sit_net *sitn = net_generic(net, sit_net_id); 1195 LIST_HEAD(list); 1196 1197 rtnl_lock(); 1198 sit_destroy_tunnels(sitn, &list); 1199 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1200 unregister_netdevice_many(&list); 1201 rtnl_unlock(); 1202} 1203 1204static struct pernet_operations sit_net_ops = { 1205 .init = sit_init_net, 1206 .exit = sit_exit_net, 1207 .id = &sit_net_id, 1208 .size = sizeof(struct sit_net), 1209}; 1210 1211static void __exit sit_cleanup(void) 1212{ 1213 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1214 1215 unregister_pernet_device(&sit_net_ops); 1216 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1217} 1218 1219static int __init sit_init(void) 1220{ 1221 int err; 1222 1223 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1224 1225 err = register_pernet_device(&sit_net_ops); 1226 if (err < 0) 1227 return err; 1228 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1229 if (err < 0) { 1230 unregister_pernet_device(&sit_net_ops); 1231 printk(KERN_INFO "sit init: Can't add protocol\n"); 1232 } 1233 return err; 1234} 1235 1236module_init(sit_init); 1237module_exit(sit_cleanup); 1238MODULE_LICENSE("GPL"); 1239MODULE_ALIAS("sit0"); 1240