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 void ipip6_tunnel_init(struct net_device *dev); 67 static void ipip6_tunnel_setup(struct net_device *dev); 68 69 static int sit_net_id __read_mostly; 70 struct 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 */ 83 static 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 */ 91 static 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 } 123 124 static 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 } 142 143 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn, 144 struct ip_tunnel *t) 145 { 146 return __ipip6_bucket(sitn, &t->parms); 147 } 148 149 static 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 } 162 163 static 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 } 172 173 static 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 } 189 190 static 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; 245 246 failed_free: 247 free_netdev(dev); 248 failed: 249 return NULL; 250 } 251 252 static DEFINE_SPINLOCK(ipip6_prl_lock); 253 254 #define for_each_prl_rcu(start) \ 255 for (prl = rcu_dereference(start); \ 256 prl; \ 257 prl = rcu_dereference(prl->next)) 258 259 static struct ip_tunnel_prl_entry * 260 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 261 { 262 struct ip_tunnel_prl_entry *prl; 263 264 for_each_prl_rcu(t->prl) 265 if (prl->addr == addr) 266 break; 267 return prl; 268 269 } 270 271 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 272 struct ip_tunnel_prl __user *a) 273 { 274 struct ip_tunnel_prl kprl, *kp; 275 struct ip_tunnel_prl_entry *prl; 276 unsigned int cmax, c = 0, ca, len; 277 int ret = 0; 278 279 if (copy_from_user(&kprl, a, sizeof(kprl))) 280 return -EFAULT; 281 cmax = kprl.datalen / sizeof(kprl); 282 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 283 cmax = 1; 284 285 /* For simple GET or for root users, 286 * we try harder to allocate. 287 */ 288 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 289 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 290 NULL; 291 292 rcu_read_lock(); 293 294 ca = t->prl_count < cmax ? t->prl_count : cmax; 295 296 if (!kp) { 297 /* We don't try hard to allocate much memory for 298 * non-root users. 299 * For root users, retry allocating enough memory for 300 * the answer. 301 */ 302 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 303 if (!kp) { 304 ret = -ENOMEM; 305 goto out; 306 } 307 } 308 309 c = 0; 310 for_each_prl_rcu(t->prl) { 311 if (c >= cmax) 312 break; 313 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 314 continue; 315 kp[c].addr = prl->addr; 316 kp[c].flags = prl->flags; 317 c++; 318 if (kprl.addr != htonl(INADDR_ANY)) 319 break; 320 } 321 out: 322 rcu_read_unlock(); 323 324 len = sizeof(*kp) * c; 325 ret = 0; 326 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 327 ret = -EFAULT; 328 329 kfree(kp); 330 331 return ret; 332 } 333 334 static int 335 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 336 { 337 struct ip_tunnel_prl_entry *p; 338 int err = 0; 339 340 if (a->addr == htonl(INADDR_ANY)) 341 return -EINVAL; 342 343 spin_lock(&ipip6_prl_lock); 344 345 for (p = t->prl; p; p = p->next) { 346 if (p->addr == a->addr) { 347 if (chg) { 348 p->flags = a->flags; 349 goto out; 350 } 351 err = -EEXIST; 352 goto out; 353 } 354 } 355 356 if (chg) { 357 err = -ENXIO; 358 goto out; 359 } 360 361 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 362 if (!p) { 363 err = -ENOBUFS; 364 goto out; 365 } 366 367 p->next = t->prl; 368 p->addr = a->addr; 369 p->flags = a->flags; 370 t->prl_count++; 371 rcu_assign_pointer(t->prl, p); 372 out: 373 spin_unlock(&ipip6_prl_lock); 374 return err; 375 } 376 377 static void prl_entry_destroy_rcu(struct rcu_head *head) 378 { 379 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head)); 380 } 381 382 static void prl_list_destroy_rcu(struct rcu_head *head) 383 { 384 struct ip_tunnel_prl_entry *p, *n; 385 386 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 387 do { 388 n = p->next; 389 kfree(p); 390 p = n; 391 } while (p); 392 } 393 394 static int 395 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 396 { 397 struct ip_tunnel_prl_entry *x, **p; 398 int err = 0; 399 400 spin_lock(&ipip6_prl_lock); 401 402 if (a && a->addr != htonl(INADDR_ANY)) { 403 for (p = &t->prl; *p; p = &(*p)->next) { 404 if ((*p)->addr == a->addr) { 405 x = *p; 406 *p = x->next; 407 call_rcu(&x->rcu_head, prl_entry_destroy_rcu); 408 t->prl_count--; 409 goto out; 410 } 411 } 412 err = -ENXIO; 413 } else { 414 if (t->prl) { 415 t->prl_count = 0; 416 x = t->prl; 417 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 418 t->prl = NULL; 419 } 420 } 421 out: 422 spin_unlock(&ipip6_prl_lock); 423 return err; 424 } 425 426 static int 427 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 428 { 429 struct ip_tunnel_prl_entry *p; 430 int ok = 1; 431 432 rcu_read_lock(); 433 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 434 if (p) { 435 if (p->flags & PRL_DEFAULT) 436 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 437 else 438 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 439 } else { 440 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 441 if (ipv6_addr_is_isatap(addr6) && 442 (addr6->s6_addr32[3] == iph->saddr) && 443 ipv6_chk_prefix(addr6, t->dev)) 444 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 445 else 446 ok = 0; 447 } 448 rcu_read_unlock(); 449 return ok; 450 } 451 452 static void ipip6_tunnel_uninit(struct net_device *dev) 453 { 454 struct net *net = dev_net(dev); 455 struct sit_net *sitn = net_generic(net, sit_net_id); 456 457 if (dev == sitn->fb_tunnel_dev) { 458 spin_lock_bh(&ipip6_lock); 459 sitn->tunnels_wc[0] = NULL; 460 spin_unlock_bh(&ipip6_lock); 461 dev_put(dev); 462 } else { 463 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 464 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 465 dev_put(dev); 466 } 467 } 468 469 470 static int ipip6_err(struct sk_buff *skb, u32 info) 471 { 472 473 /* All the routers (except for Linux) return only 474 8 bytes of packet payload. It means, that precise relaying of 475 ICMP in the real Internet is absolutely infeasible. 476 */ 477 struct iphdr *iph = (struct iphdr*)skb->data; 478 const int type = icmp_hdr(skb)->type; 479 const int code = icmp_hdr(skb)->code; 480 struct ip_tunnel *t; 481 int err; 482 483 switch (type) { 484 default: 485 case ICMP_PARAMETERPROB: 486 return 0; 487 488 case ICMP_DEST_UNREACH: 489 switch (code) { 490 case ICMP_SR_FAILED: 491 case ICMP_PORT_UNREACH: 492 /* Impossible event. */ 493 return 0; 494 case ICMP_FRAG_NEEDED: 495 /* Soft state for pmtu is maintained by IP core. */ 496 return 0; 497 default: 498 /* All others are translated to HOST_UNREACH. 499 rfc2003 contains "deep thoughts" about NET_UNREACH, 500 I believe they are just ether pollution. --ANK 501 */ 502 break; 503 } 504 break; 505 case ICMP_TIME_EXCEEDED: 506 if (code != ICMP_EXC_TTL) 507 return 0; 508 break; 509 } 510 511 err = -ENOENT; 512 513 rcu_read_lock(); 514 t = ipip6_tunnel_lookup(dev_net(skb->dev), 515 skb->dev, 516 iph->daddr, 517 iph->saddr); 518 if (t == NULL || t->parms.iph.daddr == 0) 519 goto out; 520 521 err = 0; 522 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 523 goto out; 524 525 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 526 t->err_count++; 527 else 528 t->err_count = 1; 529 t->err_time = jiffies; 530 out: 531 rcu_read_unlock(); 532 return err; 533 } 534 535 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 536 { 537 if (INET_ECN_is_ce(iph->tos)) 538 IP6_ECN_set_ce(ipv6_hdr(skb)); 539 } 540 541 static int ipip6_rcv(struct sk_buff *skb) 542 { 543 struct iphdr *iph; 544 struct ip_tunnel *tunnel; 545 546 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 547 goto out; 548 549 iph = ip_hdr(skb); 550 551 rcu_read_lock(); 552 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 553 iph->saddr, iph->daddr); 554 if (tunnel != NULL) { 555 secpath_reset(skb); 556 skb->mac_header = skb->network_header; 557 skb_reset_network_header(skb); 558 IPCB(skb)->flags = 0; 559 skb->protocol = htons(ETH_P_IPV6); 560 skb->pkt_type = PACKET_HOST; 561 562 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 563 !isatap_chksrc(skb, iph, tunnel)) { 564 tunnel->dev->stats.rx_errors++; 565 rcu_read_unlock(); 566 kfree_skb(skb); 567 return 0; 568 } 569 570 skb_tunnel_rx(skb, tunnel->dev); 571 572 ipip6_ecn_decapsulate(iph, skb); 573 netif_rx(skb); 574 rcu_read_unlock(); 575 return 0; 576 } 577 578 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 579 rcu_read_unlock(); 580 out: 581 kfree_skb(skb); 582 return 0; 583 } 584 585 /* 586 * Returns the embedded IPv4 address if the IPv6 address 587 * comes from 6rd / 6to4 (RFC 3056) addr space. 588 */ 589 static inline 590 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel) 591 { 592 __be32 dst = 0; 593 594 #ifdef CONFIG_IPV6_SIT_6RD 595 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 596 tunnel->ip6rd.prefixlen)) { 597 unsigned pbw0, pbi0; 598 int pbi1; 599 u32 d; 600 601 pbw0 = tunnel->ip6rd.prefixlen >> 5; 602 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 603 604 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 605 tunnel->ip6rd.relay_prefixlen; 606 607 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 608 if (pbi1 > 0) 609 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 610 (32 - pbi1); 611 612 dst = tunnel->ip6rd.relay_prefix | htonl(d); 613 } 614 #else 615 if (v6dst->s6_addr16[0] == htons(0x2002)) { 616 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 617 memcpy(&dst, &v6dst->s6_addr16[1], 4); 618 } 619 #endif 620 return dst; 621 } 622 623 /* 624 * This function assumes it is being called from dev_queue_xmit() 625 * and that skb is filled properly by that function. 626 */ 627 628 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 629 struct net_device *dev) 630 { 631 struct ip_tunnel *tunnel = netdev_priv(dev); 632 struct net_device_stats *stats = &dev->stats; 633 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); 634 struct iphdr *tiph = &tunnel->parms.iph; 635 struct ipv6hdr *iph6 = ipv6_hdr(skb); 636 u8 tos = tunnel->parms.iph.tos; 637 __be16 df = tiph->frag_off; 638 struct rtable *rt; /* Route to the other host */ 639 struct net_device *tdev; /* Device to other host */ 640 struct iphdr *iph; /* Our new IP header */ 641 unsigned int max_headroom; /* The extra header space needed */ 642 __be32 dst = tiph->daddr; 643 int mtu; 644 struct in6_addr *addr6; 645 int addr_type; 646 647 if (skb->protocol != htons(ETH_P_IPV6)) 648 goto tx_error; 649 650 /* ISATAP (RFC4214) - must come before 6to4 */ 651 if (dev->priv_flags & IFF_ISATAP) { 652 struct neighbour *neigh = NULL; 653 654 if (skb_dst(skb)) 655 neigh = skb_dst(skb)->neighbour; 656 657 if (neigh == NULL) { 658 if (net_ratelimit()) 659 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 660 goto tx_error; 661 } 662 663 addr6 = (struct in6_addr*)&neigh->primary_key; 664 addr_type = ipv6_addr_type(addr6); 665 666 if ((addr_type & IPV6_ADDR_UNICAST) && 667 ipv6_addr_is_isatap(addr6)) 668 dst = addr6->s6_addr32[3]; 669 else 670 goto tx_error; 671 } 672 673 if (!dst) 674 dst = try_6rd(&iph6->daddr, tunnel); 675 676 if (!dst) { 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 = (struct in6_addr*)&neigh->primary_key; 689 addr_type = ipv6_addr_type(addr6); 690 691 if (addr_type == IPV6_ADDR_ANY) { 692 addr6 = &ipv6_hdr(skb)->daddr; 693 addr_type = ipv6_addr_type(addr6); 694 } 695 696 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 697 goto tx_error_icmp; 698 699 dst = addr6->s6_addr32[3]; 700 } 701 702 { 703 struct flowi fl = { .nl_u = { .ip4_u = 704 { .daddr = dst, 705 .saddr = tiph->saddr, 706 .tos = RT_TOS(tos) } }, 707 .oif = tunnel->parms.link, 708 .proto = IPPROTO_IPV6 }; 709 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 710 stats->tx_carrier_errors++; 711 goto tx_error_icmp; 712 } 713 } 714 if (rt->rt_type != RTN_UNICAST) { 715 ip_rt_put(rt); 716 stats->tx_carrier_errors++; 717 goto tx_error_icmp; 718 } 719 tdev = rt->u.dst.dev; 720 721 if (tdev == dev) { 722 ip_rt_put(rt); 723 stats->collisions++; 724 goto tx_error; 725 } 726 727 if (df) { 728 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 729 730 if (mtu < 68) { 731 stats->collisions++; 732 ip_rt_put(rt); 733 goto tx_error; 734 } 735 736 if (mtu < IPV6_MIN_MTU) { 737 mtu = IPV6_MIN_MTU; 738 df = 0; 739 } 740 741 if (tunnel->parms.iph.daddr && skb_dst(skb)) 742 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 743 744 if (skb->len > mtu) { 745 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 746 ip_rt_put(rt); 747 goto tx_error; 748 } 749 } 750 751 if (tunnel->err_count > 0) { 752 if (time_before(jiffies, 753 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 754 tunnel->err_count--; 755 dst_link_failure(skb); 756 } else 757 tunnel->err_count = 0; 758 } 759 760 /* 761 * Okay, now see if we can stuff it in the buffer as-is. 762 */ 763 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 764 765 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 766 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 767 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 768 if (!new_skb) { 769 ip_rt_put(rt); 770 txq->tx_dropped++; 771 dev_kfree_skb(skb); 772 return NETDEV_TX_OK; 773 } 774 if (skb->sk) 775 skb_set_owner_w(new_skb, skb->sk); 776 dev_kfree_skb(skb); 777 skb = new_skb; 778 iph6 = ipv6_hdr(skb); 779 } 780 781 skb->transport_header = skb->network_header; 782 skb_push(skb, sizeof(struct iphdr)); 783 skb_reset_network_header(skb); 784 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 785 IPCB(skb)->flags = 0; 786 skb_dst_drop(skb); 787 skb_dst_set(skb, &rt->u.dst); 788 789 /* 790 * Push down and install the IPIP header. 791 */ 792 793 iph = ip_hdr(skb); 794 iph->version = 4; 795 iph->ihl = sizeof(struct iphdr)>>2; 796 iph->frag_off = df; 797 iph->protocol = IPPROTO_IPV6; 798 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 799 iph->daddr = rt->rt_dst; 800 iph->saddr = rt->rt_src; 801 802 if ((iph->ttl = tiph->ttl) == 0) 803 iph->ttl = iph6->hop_limit; 804 805 nf_reset(skb); 806 807 IPTUNNEL_XMIT(); 808 return NETDEV_TX_OK; 809 810 tx_error_icmp: 811 dst_link_failure(skb); 812 tx_error: 813 stats->tx_errors++; 814 dev_kfree_skb(skb); 815 return NETDEV_TX_OK; 816 } 817 818 static void ipip6_tunnel_bind_dev(struct net_device *dev) 819 { 820 struct net_device *tdev = NULL; 821 struct ip_tunnel *tunnel; 822 struct iphdr *iph; 823 824 tunnel = netdev_priv(dev); 825 iph = &tunnel->parms.iph; 826 827 if (iph->daddr) { 828 struct flowi fl = { .nl_u = { .ip4_u = 829 { .daddr = iph->daddr, 830 .saddr = iph->saddr, 831 .tos = RT_TOS(iph->tos) } }, 832 .oif = tunnel->parms.link, 833 .proto = IPPROTO_IPV6 }; 834 struct rtable *rt; 835 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 836 tdev = rt->u.dst.dev; 837 ip_rt_put(rt); 838 } 839 dev->flags |= IFF_POINTOPOINT; 840 } 841 842 if (!tdev && tunnel->parms.link) 843 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 844 845 if (tdev) { 846 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 847 dev->mtu = tdev->mtu - sizeof(struct iphdr); 848 if (dev->mtu < IPV6_MIN_MTU) 849 dev->mtu = IPV6_MIN_MTU; 850 } 851 dev->iflink = tunnel->parms.link; 852 } 853 854 static int 855 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 856 { 857 int err = 0; 858 struct ip_tunnel_parm p; 859 struct ip_tunnel_prl prl; 860 struct ip_tunnel *t; 861 struct net *net = dev_net(dev); 862 struct sit_net *sitn = net_generic(net, sit_net_id); 863 #ifdef CONFIG_IPV6_SIT_6RD 864 struct ip_tunnel_6rd ip6rd; 865 #endif 866 867 switch (cmd) { 868 case SIOCGETTUNNEL: 869 #ifdef CONFIG_IPV6_SIT_6RD 870 case SIOCGET6RD: 871 #endif 872 t = NULL; 873 if (dev == sitn->fb_tunnel_dev) { 874 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 875 err = -EFAULT; 876 break; 877 } 878 t = ipip6_tunnel_locate(net, &p, 0); 879 } 880 if (t == NULL) 881 t = netdev_priv(dev); 882 883 err = -EFAULT; 884 if (cmd == SIOCGETTUNNEL) { 885 memcpy(&p, &t->parms, sizeof(p)); 886 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 887 sizeof(p))) 888 goto done; 889 #ifdef CONFIG_IPV6_SIT_6RD 890 } else { 891 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 892 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 893 ip6rd.prefixlen = t->ip6rd.prefixlen; 894 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 895 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 896 sizeof(ip6rd))) 897 goto done; 898 #endif 899 } 900 err = 0; 901 break; 902 903 case SIOCADDTUNNEL: 904 case SIOCCHGTUNNEL: 905 err = -EPERM; 906 if (!capable(CAP_NET_ADMIN)) 907 goto done; 908 909 err = -EFAULT; 910 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 911 goto done; 912 913 err = -EINVAL; 914 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 915 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 916 goto done; 917 if (p.iph.ttl) 918 p.iph.frag_off |= htons(IP_DF); 919 920 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 921 922 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 923 if (t != NULL) { 924 if (t->dev != dev) { 925 err = -EEXIST; 926 break; 927 } 928 } else { 929 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 930 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 931 err = -EINVAL; 932 break; 933 } 934 t = netdev_priv(dev); 935 ipip6_tunnel_unlink(sitn, t); 936 t->parms.iph.saddr = p.iph.saddr; 937 t->parms.iph.daddr = p.iph.daddr; 938 memcpy(dev->dev_addr, &p.iph.saddr, 4); 939 memcpy(dev->broadcast, &p.iph.daddr, 4); 940 ipip6_tunnel_link(sitn, t); 941 netdev_state_change(dev); 942 } 943 } 944 945 if (t) { 946 err = 0; 947 if (cmd == SIOCCHGTUNNEL) { 948 t->parms.iph.ttl = p.iph.ttl; 949 t->parms.iph.tos = p.iph.tos; 950 if (t->parms.link != p.link) { 951 t->parms.link = p.link; 952 ipip6_tunnel_bind_dev(dev); 953 netdev_state_change(dev); 954 } 955 } 956 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 957 err = -EFAULT; 958 } else 959 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 960 break; 961 962 case SIOCDELTUNNEL: 963 err = -EPERM; 964 if (!capable(CAP_NET_ADMIN)) 965 goto done; 966 967 if (dev == sitn->fb_tunnel_dev) { 968 err = -EFAULT; 969 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 970 goto done; 971 err = -ENOENT; 972 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 973 goto done; 974 err = -EPERM; 975 if (t == netdev_priv(sitn->fb_tunnel_dev)) 976 goto done; 977 dev = t->dev; 978 } 979 unregister_netdevice(dev); 980 err = 0; 981 break; 982 983 case SIOCGETPRL: 984 err = -EINVAL; 985 if (dev == sitn->fb_tunnel_dev) 986 goto done; 987 err = -ENOENT; 988 if (!(t = netdev_priv(dev))) 989 goto done; 990 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 991 break; 992 993 case SIOCADDPRL: 994 case SIOCDELPRL: 995 case SIOCCHGPRL: 996 err = -EPERM; 997 if (!capable(CAP_NET_ADMIN)) 998 goto done; 999 err = -EINVAL; 1000 if (dev == sitn->fb_tunnel_dev) 1001 goto done; 1002 err = -EFAULT; 1003 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1004 goto done; 1005 err = -ENOENT; 1006 if (!(t = netdev_priv(dev))) 1007 goto done; 1008 1009 switch (cmd) { 1010 case SIOCDELPRL: 1011 err = ipip6_tunnel_del_prl(t, &prl); 1012 break; 1013 case SIOCADDPRL: 1014 case SIOCCHGPRL: 1015 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1016 break; 1017 } 1018 netdev_state_change(dev); 1019 break; 1020 1021 #ifdef CONFIG_IPV6_SIT_6RD 1022 case SIOCADD6RD: 1023 case SIOCCHG6RD: 1024 case SIOCDEL6RD: 1025 err = -EPERM; 1026 if (!capable(CAP_NET_ADMIN)) 1027 goto done; 1028 1029 err = -EFAULT; 1030 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1031 sizeof(ip6rd))) 1032 goto done; 1033 1034 t = netdev_priv(dev); 1035 1036 if (cmd != SIOCDEL6RD) { 1037 struct in6_addr prefix; 1038 __be32 relay_prefix; 1039 1040 err = -EINVAL; 1041 if (ip6rd.relay_prefixlen > 32 || 1042 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1043 goto done; 1044 1045 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1046 ip6rd.prefixlen); 1047 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1048 goto done; 1049 if (ip6rd.relay_prefixlen) 1050 relay_prefix = ip6rd.relay_prefix & 1051 htonl(0xffffffffUL << 1052 (32 - ip6rd.relay_prefixlen)); 1053 else 1054 relay_prefix = 0; 1055 if (relay_prefix != ip6rd.relay_prefix) 1056 goto done; 1057 1058 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1059 t->ip6rd.relay_prefix = relay_prefix; 1060 t->ip6rd.prefixlen = ip6rd.prefixlen; 1061 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1062 } else 1063 ipip6_tunnel_clone_6rd(dev, sitn); 1064 1065 err = 0; 1066 break; 1067 #endif 1068 1069 default: 1070 err = -EINVAL; 1071 } 1072 1073 done: 1074 return err; 1075 } 1076 1077 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1078 { 1079 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1080 return -EINVAL; 1081 dev->mtu = new_mtu; 1082 return 0; 1083 } 1084 1085 static const struct net_device_ops ipip6_netdev_ops = { 1086 .ndo_uninit = ipip6_tunnel_uninit, 1087 .ndo_start_xmit = ipip6_tunnel_xmit, 1088 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1089 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1090 }; 1091 1092 static void ipip6_tunnel_setup(struct net_device *dev) 1093 { 1094 dev->netdev_ops = &ipip6_netdev_ops; 1095 dev->destructor = free_netdev; 1096 1097 dev->type = ARPHRD_SIT; 1098 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1099 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1100 dev->flags = IFF_NOARP; 1101 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1102 dev->iflink = 0; 1103 dev->addr_len = 4; 1104 dev->features |= NETIF_F_NETNS_LOCAL; 1105 } 1106 1107 static void ipip6_tunnel_init(struct net_device *dev) 1108 { 1109 struct ip_tunnel *tunnel = netdev_priv(dev); 1110 1111 tunnel->dev = dev; 1112 strcpy(tunnel->parms.name, dev->name); 1113 1114 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1115 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1116 1117 ipip6_tunnel_bind_dev(dev); 1118 } 1119 1120 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1121 { 1122 struct ip_tunnel *tunnel = netdev_priv(dev); 1123 struct iphdr *iph = &tunnel->parms.iph; 1124 struct net *net = dev_net(dev); 1125 struct sit_net *sitn = net_generic(net, sit_net_id); 1126 1127 tunnel->dev = dev; 1128 strcpy(tunnel->parms.name, dev->name); 1129 1130 iph->version = 4; 1131 iph->protocol = IPPROTO_IPV6; 1132 iph->ihl = 5; 1133 iph->ttl = 64; 1134 1135 dev_hold(dev); 1136 sitn->tunnels_wc[0] = tunnel; 1137 } 1138 1139 static struct xfrm_tunnel sit_handler = { 1140 .handler = ipip6_rcv, 1141 .err_handler = ipip6_err, 1142 .priority = 1, 1143 }; 1144 1145 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1146 { 1147 int prio; 1148 1149 for (prio = 1; prio < 4; prio++) { 1150 int h; 1151 for (h = 0; h < HASH_SIZE; h++) { 1152 struct ip_tunnel *t = sitn->tunnels[prio][h]; 1153 1154 while (t != NULL) { 1155 unregister_netdevice_queue(t->dev, head); 1156 t = t->next; 1157 } 1158 } 1159 } 1160 } 1161 1162 static int __net_init sit_init_net(struct net *net) 1163 { 1164 struct sit_net *sitn = net_generic(net, sit_net_id); 1165 int err; 1166 1167 sitn->tunnels[0] = sitn->tunnels_wc; 1168 sitn->tunnels[1] = sitn->tunnels_l; 1169 sitn->tunnels[2] = sitn->tunnels_r; 1170 sitn->tunnels[3] = sitn->tunnels_r_l; 1171 1172 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1173 ipip6_tunnel_setup); 1174 if (!sitn->fb_tunnel_dev) { 1175 err = -ENOMEM; 1176 goto err_alloc_dev; 1177 } 1178 dev_net_set(sitn->fb_tunnel_dev, net); 1179 1180 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1181 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1182 1183 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1184 goto err_reg_dev; 1185 1186 return 0; 1187 1188 err_reg_dev: 1189 dev_put(sitn->fb_tunnel_dev); 1190 free_netdev(sitn->fb_tunnel_dev); 1191 err_alloc_dev: 1192 return err; 1193 } 1194 1195 static void __net_exit sit_exit_net(struct net *net) 1196 { 1197 struct sit_net *sitn = net_generic(net, sit_net_id); 1198 LIST_HEAD(list); 1199 1200 rtnl_lock(); 1201 sit_destroy_tunnels(sitn, &list); 1202 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1203 unregister_netdevice_many(&list); 1204 rtnl_unlock(); 1205 } 1206 1207 static struct pernet_operations sit_net_ops = { 1208 .init = sit_init_net, 1209 .exit = sit_exit_net, 1210 .id = &sit_net_id, 1211 .size = sizeof(struct sit_net), 1212 }; 1213 1214 static void __exit sit_cleanup(void) 1215 { 1216 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1217 1218 unregister_pernet_device(&sit_net_ops); 1219 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1220 } 1221 1222 static int __init sit_init(void) 1223 { 1224 int err; 1225 1226 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1227 1228 err = register_pernet_device(&sit_net_ops); 1229 if (err < 0) 1230 return err; 1231 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1232 if (err < 0) { 1233 unregister_pernet_device(&sit_net_ops); 1234 printk(KERN_INFO "sit init: Can't add protocol\n"); 1235 } 1236 return err; 1237 } 1238 1239 module_init(sit_init); 1240 module_exit(sit_cleanup); 1241 MODULE_LICENSE("GPL"); 1242 MODULE_ALIAS("sit0"); 1243