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 * $Id: sit.c,v 1.53 2001/09/25 05:09:53 davem Exp $ 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 * 16 * Changes: 17 * Roger Venning <r.venning@telstra.com>: 6to4 support 18 * Nate Thompson <nate@thebog.net>: 6to4 support 19 */ 20 21 #include <linux/config.h> 22 #include <linux/module.h> 23 #include <linux/capability.h> 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/sched.h> 29 #include <linux/net.h> 30 #include <linux/in6.h> 31 #include <linux/netdevice.h> 32 #include <linux/if_arp.h> 33 #include <linux/icmp.h> 34 #include <asm/uaccess.h> 35 #include <linux/init.h> 36 #include <linux/netfilter_ipv4.h> 37 #include <linux/if_ether.h> 38 39 #include <net/sock.h> 40 #include <net/snmp.h> 41 42 #include <net/ipv6.h> 43 #include <net/protocol.h> 44 #include <net/transp_v6.h> 45 #include <net/ip6_fib.h> 46 #include <net/ip6_route.h> 47 #include <net/ndisc.h> 48 #include <net/addrconf.h> 49 #include <net/ip.h> 50 #include <net/udp.h> 51 #include <net/icmp.h> 52 #include <net/ipip.h> 53 #include <net/inet_ecn.h> 54 #include <net/xfrm.h> 55 #include <net/dsfield.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) ((addr^(addr>>4))&0xF) 65 66 static int ipip6_fb_tunnel_init(struct net_device *dev); 67 static int ipip6_tunnel_init(struct net_device *dev); 68 static void ipip6_tunnel_setup(struct net_device *dev); 69 70 static struct net_device *ipip6_fb_tunnel_dev; 71 72 static struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 73 static struct ip_tunnel *tunnels_r[HASH_SIZE]; 74 static struct ip_tunnel *tunnels_l[HASH_SIZE]; 75 static struct ip_tunnel *tunnels_wc[1]; 76 static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l }; 77 78 static DEFINE_RWLOCK(ipip6_lock); 79 80 static struct ip_tunnel * ipip6_tunnel_lookup(u32 remote, u32 local) 81 { 82 unsigned h0 = HASH(remote); 83 unsigned h1 = HASH(local); 84 struct ip_tunnel *t; 85 86 for (t = tunnels_r_l[h0^h1]; t; t = t->next) { 87 if (local == t->parms.iph.saddr && 88 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 89 return t; 90 } 91 for (t = tunnels_r[h0]; t; t = t->next) { 92 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 93 return t; 94 } 95 for (t = tunnels_l[h1]; t; t = t->next) { 96 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 97 return t; 98 } 99 if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) 100 return t; 101 return NULL; 102 } 103 104 static struct ip_tunnel ** ipip6_bucket(struct ip_tunnel *t) 105 { 106 u32 remote = t->parms.iph.daddr; 107 u32 local = t->parms.iph.saddr; 108 unsigned h = 0; 109 int prio = 0; 110 111 if (remote) { 112 prio |= 2; 113 h ^= HASH(remote); 114 } 115 if (local) { 116 prio |= 1; 117 h ^= HASH(local); 118 } 119 return &tunnels[prio][h]; 120 } 121 122 static void ipip6_tunnel_unlink(struct ip_tunnel *t) 123 { 124 struct ip_tunnel **tp; 125 126 for (tp = ipip6_bucket(t); *tp; tp = &(*tp)->next) { 127 if (t == *tp) { 128 write_lock_bh(&ipip6_lock); 129 *tp = t->next; 130 write_unlock_bh(&ipip6_lock); 131 break; 132 } 133 } 134 } 135 136 static void ipip6_tunnel_link(struct ip_tunnel *t) 137 { 138 struct ip_tunnel **tp = ipip6_bucket(t); 139 140 t->next = *tp; 141 write_lock_bh(&ipip6_lock); 142 *tp = t; 143 write_unlock_bh(&ipip6_lock); 144 } 145 146 static struct ip_tunnel * ipip6_tunnel_locate(struct ip_tunnel_parm *parms, int create) 147 { 148 u32 remote = parms->iph.daddr; 149 u32 local = parms->iph.saddr; 150 struct ip_tunnel *t, **tp, *nt; 151 struct net_device *dev; 152 unsigned h = 0; 153 int prio = 0; 154 char name[IFNAMSIZ]; 155 156 if (remote) { 157 prio |= 2; 158 h ^= HASH(remote); 159 } 160 if (local) { 161 prio |= 1; 162 h ^= HASH(local); 163 } 164 for (tp = &tunnels[prio][h]; (t = *tp) != NULL; tp = &t->next) { 165 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) 166 return t; 167 } 168 if (!create) 169 goto failed; 170 171 if (parms->name[0]) 172 strlcpy(name, parms->name, IFNAMSIZ); 173 else { 174 int i; 175 for (i=1; i<100; i++) { 176 sprintf(name, "sit%d", i); 177 if (__dev_get_by_name(name) == NULL) 178 break; 179 } 180 if (i==100) 181 goto failed; 182 } 183 184 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 185 if (dev == NULL) 186 return NULL; 187 188 nt = netdev_priv(dev); 189 dev->init = ipip6_tunnel_init; 190 nt->parms = *parms; 191 192 if (register_netdevice(dev) < 0) { 193 free_netdev(dev); 194 goto failed; 195 } 196 197 dev_hold(dev); 198 199 ipip6_tunnel_link(nt); 200 return nt; 201 202 failed: 203 return NULL; 204 } 205 206 static void ipip6_tunnel_uninit(struct net_device *dev) 207 { 208 if (dev == ipip6_fb_tunnel_dev) { 209 write_lock_bh(&ipip6_lock); 210 tunnels_wc[0] = NULL; 211 write_unlock_bh(&ipip6_lock); 212 dev_put(dev); 213 } else { 214 ipip6_tunnel_unlink(netdev_priv(dev)); 215 dev_put(dev); 216 } 217 } 218 219 220 static void ipip6_err(struct sk_buff *skb, u32 info) 221 { 222 #ifndef I_WISH_WORLD_WERE_PERFECT 223 224 /* It is not :-( All the routers (except for Linux) return only 225 8 bytes of packet payload. It means, that precise relaying of 226 ICMP in the real Internet is absolutely infeasible. 227 */ 228 struct iphdr *iph = (struct iphdr*)skb->data; 229 int type = skb->h.icmph->type; 230 int code = skb->h.icmph->code; 231 struct ip_tunnel *t; 232 233 switch (type) { 234 default: 235 case ICMP_PARAMETERPROB: 236 return; 237 238 case ICMP_DEST_UNREACH: 239 switch (code) { 240 case ICMP_SR_FAILED: 241 case ICMP_PORT_UNREACH: 242 /* Impossible event. */ 243 return; 244 case ICMP_FRAG_NEEDED: 245 /* Soft state for pmtu is maintained by IP core. */ 246 return; 247 default: 248 /* All others are translated to HOST_UNREACH. 249 rfc2003 contains "deep thoughts" about NET_UNREACH, 250 I believe they are just ether pollution. --ANK 251 */ 252 break; 253 } 254 break; 255 case ICMP_TIME_EXCEEDED: 256 if (code != ICMP_EXC_TTL) 257 return; 258 break; 259 } 260 261 read_lock(&ipip6_lock); 262 t = ipip6_tunnel_lookup(iph->daddr, iph->saddr); 263 if (t == NULL || t->parms.iph.daddr == 0) 264 goto out; 265 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 266 goto out; 267 268 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) 269 t->err_count++; 270 else 271 t->err_count = 1; 272 t->err_time = jiffies; 273 out: 274 read_unlock(&ipip6_lock); 275 return; 276 #else 277 struct iphdr *iph = (struct iphdr*)dp; 278 int hlen = iph->ihl<<2; 279 struct ipv6hdr *iph6; 280 int type = skb->h.icmph->type; 281 int code = skb->h.icmph->code; 282 int rel_type = 0; 283 int rel_code = 0; 284 int rel_info = 0; 285 struct sk_buff *skb2; 286 struct rt6_info *rt6i; 287 288 if (len < hlen + sizeof(struct ipv6hdr)) 289 return; 290 iph6 = (struct ipv6hdr*)(dp + hlen); 291 292 switch (type) { 293 default: 294 return; 295 case ICMP_PARAMETERPROB: 296 if (skb->h.icmph->un.gateway < hlen) 297 return; 298 299 /* So... This guy found something strange INSIDE encapsulated 300 packet. Well, he is fool, but what can we do ? 301 */ 302 rel_type = ICMPV6_PARAMPROB; 303 rel_info = skb->h.icmph->un.gateway - hlen; 304 break; 305 306 case ICMP_DEST_UNREACH: 307 switch (code) { 308 case ICMP_SR_FAILED: 309 case ICMP_PORT_UNREACH: 310 /* Impossible event. */ 311 return; 312 case ICMP_FRAG_NEEDED: 313 /* Too complicated case ... */ 314 return; 315 default: 316 /* All others are translated to HOST_UNREACH. 317 rfc2003 contains "deep thoughts" about NET_UNREACH, 318 I believe, it is just ether pollution. --ANK 319 */ 320 rel_type = ICMPV6_DEST_UNREACH; 321 rel_code = ICMPV6_ADDR_UNREACH; 322 break; 323 } 324 break; 325 case ICMP_TIME_EXCEEDED: 326 if (code != ICMP_EXC_TTL) 327 return; 328 rel_type = ICMPV6_TIME_EXCEED; 329 rel_code = ICMPV6_EXC_HOPLIMIT; 330 break; 331 } 332 333 /* Prepare fake skb to feed it to icmpv6_send */ 334 skb2 = skb_clone(skb, GFP_ATOMIC); 335 if (skb2 == NULL) 336 return; 337 dst_release(skb2->dst); 338 skb2->dst = NULL; 339 skb_pull(skb2, skb->data - (u8*)iph6); 340 skb2->nh.raw = skb2->data; 341 342 /* Try to guess incoming interface */ 343 rt6i = rt6_lookup(&iph6->saddr, NULL, NULL, 0); 344 if (rt6i && rt6i->rt6i_dev) { 345 skb2->dev = rt6i->rt6i_dev; 346 347 rt6i = rt6_lookup(&iph6->daddr, &iph6->saddr, NULL, 0); 348 349 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) { 350 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev); 351 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) { 352 rel_type = ICMPV6_DEST_UNREACH; 353 rel_code = ICMPV6_ADDR_UNREACH; 354 } 355 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 356 } 357 } 358 kfree_skb(skb2); 359 return; 360 #endif 361 } 362 363 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 364 { 365 if (INET_ECN_is_ce(iph->tos)) 366 IP6_ECN_set_ce(skb->nh.ipv6h); 367 } 368 369 static int ipip6_rcv(struct sk_buff *skb) 370 { 371 struct iphdr *iph; 372 struct ip_tunnel *tunnel; 373 374 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 375 goto out; 376 377 iph = skb->nh.iph; 378 379 read_lock(&ipip6_lock); 380 if ((tunnel = ipip6_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { 381 secpath_reset(skb); 382 skb->mac.raw = skb->nh.raw; 383 skb->nh.raw = skb->data; 384 memset(&(IPCB(skb)->opt), 0, sizeof(struct ip_options)); 385 IPCB(skb)->flags = 0; 386 skb->protocol = htons(ETH_P_IPV6); 387 skb->pkt_type = PACKET_HOST; 388 tunnel->stat.rx_packets++; 389 tunnel->stat.rx_bytes += skb->len; 390 skb->dev = tunnel->dev; 391 dst_release(skb->dst); 392 skb->dst = NULL; 393 nf_reset(skb); 394 ipip6_ecn_decapsulate(iph, skb); 395 netif_rx(skb); 396 read_unlock(&ipip6_lock); 397 return 0; 398 } 399 400 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 401 kfree_skb(skb); 402 read_unlock(&ipip6_lock); 403 out: 404 return 0; 405 } 406 407 /* Returns the embedded IPv4 address if the IPv6 address 408 comes from 6to4 (RFC 3056) addr space */ 409 410 static inline u32 try_6to4(struct in6_addr *v6dst) 411 { 412 u32 dst = 0; 413 414 if (v6dst->s6_addr16[0] == htons(0x2002)) { 415 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 416 memcpy(&dst, &v6dst->s6_addr16[1], 4); 417 } 418 return dst; 419 } 420 421 /* 422 * This function assumes it is being called from dev_queue_xmit() 423 * and that skb is filled properly by that function. 424 */ 425 426 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 427 { 428 struct ip_tunnel *tunnel = netdev_priv(dev); 429 struct net_device_stats *stats = &tunnel->stat; 430 struct iphdr *tiph = &tunnel->parms.iph; 431 struct ipv6hdr *iph6 = skb->nh.ipv6h; 432 u8 tos = tunnel->parms.iph.tos; 433 struct rtable *rt; /* Route to the other host */ 434 struct net_device *tdev; /* Device to other host */ 435 struct iphdr *iph; /* Our new IP header */ 436 int max_headroom; /* The extra header space needed */ 437 u32 dst = tiph->daddr; 438 int mtu; 439 struct in6_addr *addr6; 440 int addr_type; 441 442 if (tunnel->recursion++) { 443 tunnel->stat.collisions++; 444 goto tx_error; 445 } 446 447 if (skb->protocol != htons(ETH_P_IPV6)) 448 goto tx_error; 449 450 if (!dst) 451 dst = try_6to4(&iph6->daddr); 452 453 if (!dst) { 454 struct neighbour *neigh = NULL; 455 456 if (skb->dst) 457 neigh = skb->dst->neighbour; 458 459 if (neigh == NULL) { 460 if (net_ratelimit()) 461 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 462 goto tx_error; 463 } 464 465 addr6 = (struct in6_addr*)&neigh->primary_key; 466 addr_type = ipv6_addr_type(addr6); 467 468 if (addr_type == IPV6_ADDR_ANY) { 469 addr6 = &skb->nh.ipv6h->daddr; 470 addr_type = ipv6_addr_type(addr6); 471 } 472 473 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 474 goto tx_error_icmp; 475 476 dst = addr6->s6_addr32[3]; 477 } 478 479 { 480 struct flowi fl = { .nl_u = { .ip4_u = 481 { .daddr = dst, 482 .saddr = tiph->saddr, 483 .tos = RT_TOS(tos) } }, 484 .oif = tunnel->parms.link, 485 .proto = IPPROTO_IPV6 }; 486 if (ip_route_output_key(&rt, &fl)) { 487 tunnel->stat.tx_carrier_errors++; 488 goto tx_error_icmp; 489 } 490 } 491 if (rt->rt_type != RTN_UNICAST) { 492 ip_rt_put(rt); 493 tunnel->stat.tx_carrier_errors++; 494 goto tx_error_icmp; 495 } 496 tdev = rt->u.dst.dev; 497 498 if (tdev == dev) { 499 ip_rt_put(rt); 500 tunnel->stat.collisions++; 501 goto tx_error; 502 } 503 504 if (tiph->frag_off) 505 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 506 else 507 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; 508 509 if (mtu < 68) { 510 tunnel->stat.collisions++; 511 ip_rt_put(rt); 512 goto tx_error; 513 } 514 if (mtu < IPV6_MIN_MTU) 515 mtu = IPV6_MIN_MTU; 516 if (tunnel->parms.iph.daddr && skb->dst) 517 skb->dst->ops->update_pmtu(skb->dst, mtu); 518 519 if (skb->len > mtu) { 520 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 521 ip_rt_put(rt); 522 goto tx_error; 523 } 524 525 if (tunnel->err_count > 0) { 526 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { 527 tunnel->err_count--; 528 dst_link_failure(skb); 529 } else 530 tunnel->err_count = 0; 531 } 532 533 /* 534 * Okay, now see if we can stuff it in the buffer as-is. 535 */ 536 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 537 538 if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { 539 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 540 if (!new_skb) { 541 ip_rt_put(rt); 542 stats->tx_dropped++; 543 dev_kfree_skb(skb); 544 tunnel->recursion--; 545 return 0; 546 } 547 if (skb->sk) 548 skb_set_owner_w(new_skb, skb->sk); 549 dev_kfree_skb(skb); 550 skb = new_skb; 551 iph6 = skb->nh.ipv6h; 552 } 553 554 skb->h.raw = skb->nh.raw; 555 skb->nh.raw = skb_push(skb, sizeof(struct iphdr)); 556 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 557 IPCB(skb)->flags = 0; 558 dst_release(skb->dst); 559 skb->dst = &rt->u.dst; 560 561 /* 562 * Push down and install the IPIP header. 563 */ 564 565 iph = skb->nh.iph; 566 iph->version = 4; 567 iph->ihl = sizeof(struct iphdr)>>2; 568 if (mtu > IPV6_MIN_MTU) 569 iph->frag_off = htons(IP_DF); 570 else 571 iph->frag_off = 0; 572 573 iph->protocol = IPPROTO_IPV6; 574 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 575 iph->daddr = rt->rt_dst; 576 iph->saddr = rt->rt_src; 577 578 if ((iph->ttl = tiph->ttl) == 0) 579 iph->ttl = iph6->hop_limit; 580 581 nf_reset(skb); 582 583 IPTUNNEL_XMIT(); 584 tunnel->recursion--; 585 return 0; 586 587 tx_error_icmp: 588 dst_link_failure(skb); 589 tx_error: 590 stats->tx_errors++; 591 dev_kfree_skb(skb); 592 tunnel->recursion--; 593 return 0; 594 } 595 596 static int 597 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 598 { 599 int err = 0; 600 struct ip_tunnel_parm p; 601 struct ip_tunnel *t; 602 603 switch (cmd) { 604 case SIOCGETTUNNEL: 605 t = NULL; 606 if (dev == ipip6_fb_tunnel_dev) { 607 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 608 err = -EFAULT; 609 break; 610 } 611 t = ipip6_tunnel_locate(&p, 0); 612 } 613 if (t == NULL) 614 t = netdev_priv(dev); 615 memcpy(&p, &t->parms, sizeof(p)); 616 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 617 err = -EFAULT; 618 break; 619 620 case SIOCADDTUNNEL: 621 case SIOCCHGTUNNEL: 622 err = -EPERM; 623 if (!capable(CAP_NET_ADMIN)) 624 goto done; 625 626 err = -EFAULT; 627 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 628 goto done; 629 630 err = -EINVAL; 631 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 632 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 633 goto done; 634 if (p.iph.ttl) 635 p.iph.frag_off |= htons(IP_DF); 636 637 t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL); 638 639 if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 640 if (t != NULL) { 641 if (t->dev != dev) { 642 err = -EEXIST; 643 break; 644 } 645 } else { 646 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 647 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 648 err = -EINVAL; 649 break; 650 } 651 t = netdev_priv(dev); 652 ipip6_tunnel_unlink(t); 653 t->parms.iph.saddr = p.iph.saddr; 654 t->parms.iph.daddr = p.iph.daddr; 655 memcpy(dev->dev_addr, &p.iph.saddr, 4); 656 memcpy(dev->broadcast, &p.iph.daddr, 4); 657 ipip6_tunnel_link(t); 658 netdev_state_change(dev); 659 } 660 } 661 662 if (t) { 663 err = 0; 664 if (cmd == SIOCCHGTUNNEL) { 665 t->parms.iph.ttl = p.iph.ttl; 666 t->parms.iph.tos = p.iph.tos; 667 } 668 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 669 err = -EFAULT; 670 } else 671 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 672 break; 673 674 case SIOCDELTUNNEL: 675 err = -EPERM; 676 if (!capable(CAP_NET_ADMIN)) 677 goto done; 678 679 if (dev == ipip6_fb_tunnel_dev) { 680 err = -EFAULT; 681 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 682 goto done; 683 err = -ENOENT; 684 if ((t = ipip6_tunnel_locate(&p, 0)) == NULL) 685 goto done; 686 err = -EPERM; 687 if (t == netdev_priv(ipip6_fb_tunnel_dev)) 688 goto done; 689 dev = t->dev; 690 } 691 err = unregister_netdevice(dev); 692 break; 693 694 default: 695 err = -EINVAL; 696 } 697 698 done: 699 return err; 700 } 701 702 static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev) 703 { 704 return &(((struct ip_tunnel*)netdev_priv(dev))->stat); 705 } 706 707 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 708 { 709 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 710 return -EINVAL; 711 dev->mtu = new_mtu; 712 return 0; 713 } 714 715 static void ipip6_tunnel_setup(struct net_device *dev) 716 { 717 SET_MODULE_OWNER(dev); 718 dev->uninit = ipip6_tunnel_uninit; 719 dev->destructor = free_netdev; 720 dev->hard_start_xmit = ipip6_tunnel_xmit; 721 dev->get_stats = ipip6_tunnel_get_stats; 722 dev->do_ioctl = ipip6_tunnel_ioctl; 723 dev->change_mtu = ipip6_tunnel_change_mtu; 724 725 dev->type = ARPHRD_SIT; 726 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 727 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 728 dev->flags = IFF_NOARP; 729 dev->iflink = 0; 730 dev->addr_len = 4; 731 } 732 733 static int ipip6_tunnel_init(struct net_device *dev) 734 { 735 struct net_device *tdev = NULL; 736 struct ip_tunnel *tunnel; 737 struct iphdr *iph; 738 739 tunnel = netdev_priv(dev); 740 iph = &tunnel->parms.iph; 741 742 tunnel->dev = dev; 743 strcpy(tunnel->parms.name, dev->name); 744 745 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 746 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 747 748 if (iph->daddr) { 749 struct flowi fl = { .nl_u = { .ip4_u = 750 { .daddr = iph->daddr, 751 .saddr = iph->saddr, 752 .tos = RT_TOS(iph->tos) } }, 753 .oif = tunnel->parms.link, 754 .proto = IPPROTO_IPV6 }; 755 struct rtable *rt; 756 if (!ip_route_output_key(&rt, &fl)) { 757 tdev = rt->u.dst.dev; 758 ip_rt_put(rt); 759 } 760 dev->flags |= IFF_POINTOPOINT; 761 } 762 763 if (!tdev && tunnel->parms.link) 764 tdev = __dev_get_by_index(tunnel->parms.link); 765 766 if (tdev) { 767 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 768 dev->mtu = tdev->mtu - sizeof(struct iphdr); 769 if (dev->mtu < IPV6_MIN_MTU) 770 dev->mtu = IPV6_MIN_MTU; 771 } 772 dev->iflink = tunnel->parms.link; 773 774 return 0; 775 } 776 777 static int __init ipip6_fb_tunnel_init(struct net_device *dev) 778 { 779 struct ip_tunnel *tunnel = netdev_priv(dev); 780 struct iphdr *iph = &tunnel->parms.iph; 781 782 tunnel->dev = dev; 783 strcpy(tunnel->parms.name, dev->name); 784 785 iph->version = 4; 786 iph->protocol = IPPROTO_IPV6; 787 iph->ihl = 5; 788 iph->ttl = 64; 789 790 dev_hold(dev); 791 tunnels_wc[0] = tunnel; 792 return 0; 793 } 794 795 static struct net_protocol sit_protocol = { 796 .handler = ipip6_rcv, 797 .err_handler = ipip6_err, 798 }; 799 800 static void __exit sit_destroy_tunnels(void) 801 { 802 int prio; 803 804 for (prio = 1; prio < 4; prio++) { 805 int h; 806 for (h = 0; h < HASH_SIZE; h++) { 807 struct ip_tunnel *t; 808 while ((t = tunnels[prio][h]) != NULL) 809 unregister_netdevice(t->dev); 810 } 811 } 812 } 813 814 void __exit sit_cleanup(void) 815 { 816 inet_del_protocol(&sit_protocol, IPPROTO_IPV6); 817 818 rtnl_lock(); 819 sit_destroy_tunnels(); 820 unregister_netdevice(ipip6_fb_tunnel_dev); 821 rtnl_unlock(); 822 } 823 824 int __init sit_init(void) 825 { 826 int err; 827 828 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 829 830 if (inet_add_protocol(&sit_protocol, IPPROTO_IPV6) < 0) { 831 printk(KERN_INFO "sit init: Can't add protocol\n"); 832 return -EAGAIN; 833 } 834 835 ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 836 ipip6_tunnel_setup); 837 if (!ipip6_fb_tunnel_dev) { 838 err = -ENOMEM; 839 goto err1; 840 } 841 842 ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init; 843 844 if ((err = register_netdev(ipip6_fb_tunnel_dev))) 845 goto err2; 846 847 out: 848 return err; 849 err2: 850 free_netdev(ipip6_fb_tunnel_dev); 851 err1: 852 inet_del_protocol(&sit_protocol, IPPROTO_IPV6); 853 goto out; 854 } 855