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 * Fred L. Templin <fltemplin@acm.org>: isatap support 20 */ 21 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/net.h> 29 #include <linux/in6.h> 30 #include <linux/netdevice.h> 31 #include <linux/if_arp.h> 32 #include <linux/icmp.h> 33 #include <asm/uaccess.h> 34 #include <linux/init.h> 35 #include <linux/netfilter_ipv4.h> 36 #include <linux/if_ether.h> 37 38 #include <net/sock.h> 39 #include <net/snmp.h> 40 41 #include <net/ipv6.h> 42 #include <net/protocol.h> 43 #include <net/transp_v6.h> 44 #include <net/ip6_fib.h> 45 #include <net/ip6_route.h> 46 #include <net/ndisc.h> 47 #include <net/addrconf.h> 48 #include <net/ip.h> 49 #include <net/udp.h> 50 #include <net/icmp.h> 51 #include <net/ipip.h> 52 #include <net/inet_ecn.h> 53 #include <net/xfrm.h> 54 #include <net/dsfield.h> 55 56 /* 57 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 58 59 For comments look at net/ipv4/ip_gre.c --ANK 60 */ 61 62 #define HASH_SIZE 16 63 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 64 65 static int ipip6_fb_tunnel_init(struct net_device *dev); 66 static int ipip6_tunnel_init(struct net_device *dev); 67 static void ipip6_tunnel_setup(struct net_device *dev); 68 69 static struct net_device *ipip6_fb_tunnel_dev; 70 71 static struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 72 static struct ip_tunnel *tunnels_r[HASH_SIZE]; 73 static struct ip_tunnel *tunnels_l[HASH_SIZE]; 74 static struct ip_tunnel *tunnels_wc[1]; 75 static struct ip_tunnel **tunnels[4] = { tunnels_wc, tunnels_l, tunnels_r, tunnels_r_l }; 76 77 static DEFINE_RWLOCK(ipip6_lock); 78 79 static struct ip_tunnel * ipip6_tunnel_lookup(__be32 remote, __be32 local) 80 { 81 unsigned h0 = HASH(remote); 82 unsigned h1 = HASH(local); 83 struct ip_tunnel *t; 84 85 for (t = tunnels_r_l[h0^h1]; t; t = t->next) { 86 if (local == t->parms.iph.saddr && 87 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 88 return t; 89 } 90 for (t = tunnels_r[h0]; t; t = t->next) { 91 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 92 return t; 93 } 94 for (t = tunnels_l[h1]; t; t = t->next) { 95 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 96 return t; 97 } 98 if ((t = tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) 99 return t; 100 return NULL; 101 } 102 103 static struct ip_tunnel **__ipip6_bucket(struct ip_tunnel_parm *parms) 104 { 105 __be32 remote = parms->iph.daddr; 106 __be32 local = parms->iph.saddr; 107 unsigned h = 0; 108 int prio = 0; 109 110 if (remote) { 111 prio |= 2; 112 h ^= HASH(remote); 113 } 114 if (local) { 115 prio |= 1; 116 h ^= HASH(local); 117 } 118 return &tunnels[prio][h]; 119 } 120 121 static inline struct ip_tunnel **ipip6_bucket(struct ip_tunnel *t) 122 { 123 return __ipip6_bucket(&t->parms); 124 } 125 126 static void ipip6_tunnel_unlink(struct ip_tunnel *t) 127 { 128 struct ip_tunnel **tp; 129 130 for (tp = ipip6_bucket(t); *tp; tp = &(*tp)->next) { 131 if (t == *tp) { 132 write_lock_bh(&ipip6_lock); 133 *tp = t->next; 134 write_unlock_bh(&ipip6_lock); 135 break; 136 } 137 } 138 } 139 140 static void ipip6_tunnel_link(struct ip_tunnel *t) 141 { 142 struct ip_tunnel **tp = ipip6_bucket(t); 143 144 t->next = *tp; 145 write_lock_bh(&ipip6_lock); 146 *tp = t; 147 write_unlock_bh(&ipip6_lock); 148 } 149 150 static struct ip_tunnel * ipip6_tunnel_locate(struct ip_tunnel_parm *parms, int create) 151 { 152 __be32 remote = parms->iph.daddr; 153 __be32 local = parms->iph.saddr; 154 struct ip_tunnel *t, **tp, *nt; 155 struct net_device *dev; 156 char name[IFNAMSIZ]; 157 158 for (tp = __ipip6_bucket(parms); (t = *tp) != NULL; tp = &t->next) { 159 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) 160 return t; 161 } 162 if (!create) 163 goto failed; 164 165 if (parms->name[0]) 166 strlcpy(name, parms->name, IFNAMSIZ); 167 else { 168 int i; 169 for (i=1; i<100; i++) { 170 sprintf(name, "sit%d", i); 171 if (__dev_get_by_name(&init_net, name) == NULL) 172 break; 173 } 174 if (i==100) 175 goto failed; 176 } 177 178 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 179 if (dev == NULL) 180 return NULL; 181 182 nt = netdev_priv(dev); 183 dev->init = ipip6_tunnel_init; 184 nt->parms = *parms; 185 186 if (parms->i_flags & SIT_ISATAP) 187 dev->priv_flags |= IFF_ISATAP; 188 189 if (register_netdevice(dev) < 0) { 190 free_netdev(dev); 191 goto failed; 192 } 193 194 dev_hold(dev); 195 196 ipip6_tunnel_link(nt); 197 return nt; 198 199 failed: 200 return NULL; 201 } 202 203 static void ipip6_tunnel_uninit(struct net_device *dev) 204 { 205 if (dev == ipip6_fb_tunnel_dev) { 206 write_lock_bh(&ipip6_lock); 207 tunnels_wc[0] = NULL; 208 write_unlock_bh(&ipip6_lock); 209 dev_put(dev); 210 } else { 211 ipip6_tunnel_unlink(netdev_priv(dev)); 212 dev_put(dev); 213 } 214 } 215 216 217 static int ipip6_err(struct sk_buff *skb, u32 info) 218 { 219 #ifndef I_WISH_WORLD_WERE_PERFECT 220 221 /* It is not :-( All the routers (except for Linux) return only 222 8 bytes of packet payload. It means, that precise relaying of 223 ICMP in the real Internet is absolutely infeasible. 224 */ 225 struct iphdr *iph = (struct iphdr*)skb->data; 226 const int type = icmp_hdr(skb)->type; 227 const int code = icmp_hdr(skb)->code; 228 struct ip_tunnel *t; 229 int err; 230 231 switch (type) { 232 default: 233 case ICMP_PARAMETERPROB: 234 return 0; 235 236 case ICMP_DEST_UNREACH: 237 switch (code) { 238 case ICMP_SR_FAILED: 239 case ICMP_PORT_UNREACH: 240 /* Impossible event. */ 241 return 0; 242 case ICMP_FRAG_NEEDED: 243 /* Soft state for pmtu is maintained by IP core. */ 244 return 0; 245 default: 246 /* All others are translated to HOST_UNREACH. 247 rfc2003 contains "deep thoughts" about NET_UNREACH, 248 I believe they are just ether pollution. --ANK 249 */ 250 break; 251 } 252 break; 253 case ICMP_TIME_EXCEEDED: 254 if (code != ICMP_EXC_TTL) 255 return 0; 256 break; 257 } 258 259 err = -ENOENT; 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; 265 266 err = 0; 267 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 268 goto out; 269 270 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) 271 t->err_count++; 272 else 273 t->err_count = 1; 274 t->err_time = jiffies; 275 out: 276 read_unlock(&ipip6_lock); 277 return err; 278 #else 279 struct iphdr *iph = (struct iphdr*)dp; 280 int hlen = iph->ihl<<2; 281 struct ipv6hdr *iph6; 282 const int type = icmp_hdr(skb)->type; 283 const int code = icmp_hdr(skb)->code; 284 int rel_type = 0; 285 int rel_code = 0; 286 int rel_info = 0; 287 struct sk_buff *skb2; 288 struct rt6_info *rt6i; 289 290 if (len < hlen + sizeof(struct ipv6hdr)) 291 return; 292 iph6 = (struct ipv6hdr*)(dp + hlen); 293 294 switch (type) { 295 default: 296 return; 297 case ICMP_PARAMETERPROB: 298 if (icmp_hdr(skb)->un.gateway < hlen) 299 return; 300 301 /* So... This guy found something strange INSIDE encapsulated 302 packet. Well, he is fool, but what can we do ? 303 */ 304 rel_type = ICMPV6_PARAMPROB; 305 rel_info = icmp_hdr(skb)->un.gateway - hlen; 306 break; 307 308 case ICMP_DEST_UNREACH: 309 switch (code) { 310 case ICMP_SR_FAILED: 311 case ICMP_PORT_UNREACH: 312 /* Impossible event. */ 313 return; 314 case ICMP_FRAG_NEEDED: 315 /* Too complicated case ... */ 316 return; 317 default: 318 /* All others are translated to HOST_UNREACH. 319 rfc2003 contains "deep thoughts" about NET_UNREACH, 320 I believe, it is just ether pollution. --ANK 321 */ 322 rel_type = ICMPV6_DEST_UNREACH; 323 rel_code = ICMPV6_ADDR_UNREACH; 324 break; 325 } 326 break; 327 case ICMP_TIME_EXCEEDED: 328 if (code != ICMP_EXC_TTL) 329 return; 330 rel_type = ICMPV6_TIME_EXCEED; 331 rel_code = ICMPV6_EXC_HOPLIMIT; 332 break; 333 } 334 335 /* Prepare fake skb to feed it to icmpv6_send */ 336 skb2 = skb_clone(skb, GFP_ATOMIC); 337 if (skb2 == NULL) 338 return 0; 339 dst_release(skb2->dst); 340 skb2->dst = NULL; 341 skb_pull(skb2, skb->data - (u8*)iph6); 342 skb_reset_network_header(skb2); 343 344 /* Try to guess incoming interface */ 345 rt6i = rt6_lookup(&iph6->saddr, NULL, NULL, 0); 346 if (rt6i && rt6i->rt6i_dev) { 347 skb2->dev = rt6i->rt6i_dev; 348 349 rt6i = rt6_lookup(&iph6->daddr, &iph6->saddr, NULL, 0); 350 351 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) { 352 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev); 353 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) { 354 rel_type = ICMPV6_DEST_UNREACH; 355 rel_code = ICMPV6_ADDR_UNREACH; 356 } 357 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 358 } 359 } 360 kfree_skb(skb2); 361 return 0; 362 #endif 363 } 364 365 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 366 { 367 if (INET_ECN_is_ce(iph->tos)) 368 IP6_ECN_set_ce(ipv6_hdr(skb)); 369 } 370 371 /* ISATAP (RFC4214) - check source address */ 372 static int 373 isatap_srcok(struct sk_buff *skb, struct iphdr *iph, struct net_device *dev) 374 { 375 struct neighbour *neigh; 376 struct dst_entry *dst; 377 struct rt6_info *rt; 378 struct flowi fl; 379 struct in6_addr *addr6; 380 struct in6_addr rtr; 381 struct ipv6hdr *iph6; 382 int ok = 0; 383 384 /* from onlink default router */ 385 ipv6_addr_set(&rtr, htonl(0xFE800000), 0, 0, 0); 386 ipv6_isatap_eui64(rtr.s6_addr + 8, iph->saddr); 387 if ((rt = rt6_get_dflt_router(&rtr, dev))) { 388 dst_release(&rt->u.dst); 389 return 1; 390 } 391 392 iph6 = ipv6_hdr(skb); 393 memset(&fl, 0, sizeof(fl)); 394 fl.proto = iph6->nexthdr; 395 ipv6_addr_copy(&fl.fl6_dst, &iph6->saddr); 396 fl.oif = dev->ifindex; 397 security_skb_classify_flow(skb, &fl); 398 399 dst = ip6_route_output(NULL, &fl); 400 if (!dst->error && (dst->dev == dev) && (neigh = dst->neighbour)) { 401 402 addr6 = (struct in6_addr*)&neigh->primary_key; 403 404 /* from correct previous hop */ 405 if (ipv6_addr_is_isatap(addr6) && 406 (addr6->s6_addr32[3] == iph->saddr)) 407 ok = 1; 408 } 409 dst_release(dst); 410 return ok; 411 } 412 413 static int ipip6_rcv(struct sk_buff *skb) 414 { 415 struct iphdr *iph; 416 struct ip_tunnel *tunnel; 417 418 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 419 goto out; 420 421 iph = ip_hdr(skb); 422 423 read_lock(&ipip6_lock); 424 if ((tunnel = ipip6_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { 425 secpath_reset(skb); 426 skb->mac_header = skb->network_header; 427 skb_reset_network_header(skb); 428 IPCB(skb)->flags = 0; 429 skb->protocol = htons(ETH_P_IPV6); 430 skb->pkt_type = PACKET_HOST; 431 432 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 433 !isatap_srcok(skb, iph, tunnel->dev)) { 434 tunnel->stat.rx_errors++; 435 read_unlock(&ipip6_lock); 436 kfree_skb(skb); 437 return 0; 438 } 439 tunnel->stat.rx_packets++; 440 tunnel->stat.rx_bytes += skb->len; 441 skb->dev = tunnel->dev; 442 dst_release(skb->dst); 443 skb->dst = NULL; 444 nf_reset(skb); 445 ipip6_ecn_decapsulate(iph, skb); 446 netif_rx(skb); 447 read_unlock(&ipip6_lock); 448 return 0; 449 } 450 451 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 452 kfree_skb(skb); 453 read_unlock(&ipip6_lock); 454 out: 455 return 0; 456 } 457 458 /* Returns the embedded IPv4 address if the IPv6 address 459 comes from 6to4 (RFC 3056) addr space */ 460 461 static inline __be32 try_6to4(struct in6_addr *v6dst) 462 { 463 __be32 dst = 0; 464 465 if (v6dst->s6_addr16[0] == htons(0x2002)) { 466 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 467 memcpy(&dst, &v6dst->s6_addr16[1], 4); 468 } 469 return dst; 470 } 471 472 /* 473 * This function assumes it is being called from dev_queue_xmit() 474 * and that skb is filled properly by that function. 475 */ 476 477 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 478 { 479 struct ip_tunnel *tunnel = netdev_priv(dev); 480 struct net_device_stats *stats = &tunnel->stat; 481 struct iphdr *tiph = &tunnel->parms.iph; 482 struct ipv6hdr *iph6 = ipv6_hdr(skb); 483 u8 tos = tunnel->parms.iph.tos; 484 struct rtable *rt; /* Route to the other host */ 485 struct net_device *tdev; /* Device to other host */ 486 struct iphdr *iph; /* Our new IP header */ 487 unsigned int max_headroom; /* The extra header space needed */ 488 __be32 dst = tiph->daddr; 489 int mtu; 490 struct in6_addr *addr6; 491 int addr_type; 492 493 if (tunnel->recursion++) { 494 tunnel->stat.collisions++; 495 goto tx_error; 496 } 497 498 if (skb->protocol != htons(ETH_P_IPV6)) 499 goto tx_error; 500 501 /* ISATAP (RFC4214) - must come before 6to4 */ 502 if (dev->priv_flags & IFF_ISATAP) { 503 struct neighbour *neigh = NULL; 504 505 if (skb->dst) 506 neigh = skb->dst->neighbour; 507 508 if (neigh == NULL) { 509 if (net_ratelimit()) 510 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 511 goto tx_error; 512 } 513 514 addr6 = (struct in6_addr*)&neigh->primary_key; 515 addr_type = ipv6_addr_type(addr6); 516 517 if ((addr_type & IPV6_ADDR_UNICAST) && 518 ipv6_addr_is_isatap(addr6)) 519 dst = addr6->s6_addr32[3]; 520 else 521 goto tx_error; 522 } 523 524 if (!dst) 525 dst = try_6to4(&iph6->daddr); 526 527 if (!dst) { 528 struct neighbour *neigh = NULL; 529 530 if (skb->dst) 531 neigh = skb->dst->neighbour; 532 533 if (neigh == NULL) { 534 if (net_ratelimit()) 535 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 536 goto tx_error; 537 } 538 539 addr6 = (struct in6_addr*)&neigh->primary_key; 540 addr_type = ipv6_addr_type(addr6); 541 542 if (addr_type == IPV6_ADDR_ANY) { 543 addr6 = &ipv6_hdr(skb)->daddr; 544 addr_type = ipv6_addr_type(addr6); 545 } 546 547 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 548 goto tx_error_icmp; 549 550 dst = addr6->s6_addr32[3]; 551 } 552 553 { 554 struct flowi fl = { .nl_u = { .ip4_u = 555 { .daddr = dst, 556 .saddr = tiph->saddr, 557 .tos = RT_TOS(tos) } }, 558 .oif = tunnel->parms.link, 559 .proto = IPPROTO_IPV6 }; 560 if (ip_route_output_key(&init_net, &rt, &fl)) { 561 tunnel->stat.tx_carrier_errors++; 562 goto tx_error_icmp; 563 } 564 } 565 if (rt->rt_type != RTN_UNICAST) { 566 ip_rt_put(rt); 567 tunnel->stat.tx_carrier_errors++; 568 goto tx_error_icmp; 569 } 570 tdev = rt->u.dst.dev; 571 572 if (tdev == dev) { 573 ip_rt_put(rt); 574 tunnel->stat.collisions++; 575 goto tx_error; 576 } 577 578 if (tiph->frag_off) 579 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 580 else 581 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; 582 583 if (mtu < 68) { 584 tunnel->stat.collisions++; 585 ip_rt_put(rt); 586 goto tx_error; 587 } 588 if (mtu < IPV6_MIN_MTU) 589 mtu = IPV6_MIN_MTU; 590 if (tunnel->parms.iph.daddr && skb->dst) 591 skb->dst->ops->update_pmtu(skb->dst, mtu); 592 593 if (skb->len > mtu) { 594 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 595 ip_rt_put(rt); 596 goto tx_error; 597 } 598 599 if (tunnel->err_count > 0) { 600 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { 601 tunnel->err_count--; 602 dst_link_failure(skb); 603 } else 604 tunnel->err_count = 0; 605 } 606 607 /* 608 * Okay, now see if we can stuff it in the buffer as-is. 609 */ 610 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 611 612 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 613 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 614 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 615 if (!new_skb) { 616 ip_rt_put(rt); 617 stats->tx_dropped++; 618 dev_kfree_skb(skb); 619 tunnel->recursion--; 620 return 0; 621 } 622 if (skb->sk) 623 skb_set_owner_w(new_skb, skb->sk); 624 dev_kfree_skb(skb); 625 skb = new_skb; 626 iph6 = ipv6_hdr(skb); 627 } 628 629 skb->transport_header = skb->network_header; 630 skb_push(skb, sizeof(struct iphdr)); 631 skb_reset_network_header(skb); 632 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 633 IPCB(skb)->flags = 0; 634 dst_release(skb->dst); 635 skb->dst = &rt->u.dst; 636 637 /* 638 * Push down and install the IPIP header. 639 */ 640 641 iph = ip_hdr(skb); 642 iph->version = 4; 643 iph->ihl = sizeof(struct iphdr)>>2; 644 if (mtu > IPV6_MIN_MTU) 645 iph->frag_off = htons(IP_DF); 646 else 647 iph->frag_off = 0; 648 649 iph->protocol = IPPROTO_IPV6; 650 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 651 iph->daddr = rt->rt_dst; 652 iph->saddr = rt->rt_src; 653 654 if ((iph->ttl = tiph->ttl) == 0) 655 iph->ttl = iph6->hop_limit; 656 657 nf_reset(skb); 658 659 IPTUNNEL_XMIT(); 660 tunnel->recursion--; 661 return 0; 662 663 tx_error_icmp: 664 dst_link_failure(skb); 665 tx_error: 666 stats->tx_errors++; 667 dev_kfree_skb(skb); 668 tunnel->recursion--; 669 return 0; 670 } 671 672 static void ipip6_tunnel_bind_dev(struct net_device *dev) 673 { 674 struct net_device *tdev = NULL; 675 struct ip_tunnel *tunnel; 676 struct iphdr *iph; 677 678 tunnel = netdev_priv(dev); 679 iph = &tunnel->parms.iph; 680 681 if (iph->daddr) { 682 struct flowi fl = { .nl_u = { .ip4_u = 683 { .daddr = iph->daddr, 684 .saddr = iph->saddr, 685 .tos = RT_TOS(iph->tos) } }, 686 .oif = tunnel->parms.link, 687 .proto = IPPROTO_IPV6 }; 688 struct rtable *rt; 689 if (!ip_route_output_key(&init_net, &rt, &fl)) { 690 tdev = rt->u.dst.dev; 691 ip_rt_put(rt); 692 } 693 dev->flags |= IFF_POINTOPOINT; 694 } 695 696 if (!tdev && tunnel->parms.link) 697 tdev = __dev_get_by_index(&init_net, tunnel->parms.link); 698 699 if (tdev) { 700 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 701 dev->mtu = tdev->mtu - sizeof(struct iphdr); 702 if (dev->mtu < IPV6_MIN_MTU) 703 dev->mtu = IPV6_MIN_MTU; 704 } 705 dev->iflink = tunnel->parms.link; 706 } 707 708 static int 709 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 710 { 711 int err = 0; 712 struct ip_tunnel_parm p; 713 struct ip_tunnel *t; 714 715 switch (cmd) { 716 case SIOCGETTUNNEL: 717 t = NULL; 718 if (dev == ipip6_fb_tunnel_dev) { 719 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 720 err = -EFAULT; 721 break; 722 } 723 t = ipip6_tunnel_locate(&p, 0); 724 } 725 if (t == NULL) 726 t = netdev_priv(dev); 727 memcpy(&p, &t->parms, sizeof(p)); 728 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 729 err = -EFAULT; 730 break; 731 732 case SIOCADDTUNNEL: 733 case SIOCCHGTUNNEL: 734 err = -EPERM; 735 if (!capable(CAP_NET_ADMIN)) 736 goto done; 737 738 err = -EFAULT; 739 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 740 goto done; 741 742 err = -EINVAL; 743 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 744 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 745 goto done; 746 if (p.iph.ttl) 747 p.iph.frag_off |= htons(IP_DF); 748 749 t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL); 750 751 if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 752 if (t != NULL) { 753 if (t->dev != dev) { 754 err = -EEXIST; 755 break; 756 } 757 } else { 758 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 759 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 760 err = -EINVAL; 761 break; 762 } 763 t = netdev_priv(dev); 764 ipip6_tunnel_unlink(t); 765 t->parms.iph.saddr = p.iph.saddr; 766 t->parms.iph.daddr = p.iph.daddr; 767 memcpy(dev->dev_addr, &p.iph.saddr, 4); 768 memcpy(dev->broadcast, &p.iph.daddr, 4); 769 ipip6_tunnel_link(t); 770 netdev_state_change(dev); 771 } 772 } 773 774 if (t) { 775 err = 0; 776 if (cmd == SIOCCHGTUNNEL) { 777 t->parms.iph.ttl = p.iph.ttl; 778 t->parms.iph.tos = p.iph.tos; 779 if (t->parms.link != p.link) { 780 t->parms.link = p.link; 781 ipip6_tunnel_bind_dev(dev); 782 netdev_state_change(dev); 783 } 784 } 785 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 786 err = -EFAULT; 787 } else 788 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 789 break; 790 791 case SIOCDELTUNNEL: 792 err = -EPERM; 793 if (!capable(CAP_NET_ADMIN)) 794 goto done; 795 796 if (dev == ipip6_fb_tunnel_dev) { 797 err = -EFAULT; 798 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 799 goto done; 800 err = -ENOENT; 801 if ((t = ipip6_tunnel_locate(&p, 0)) == NULL) 802 goto done; 803 err = -EPERM; 804 if (t == netdev_priv(ipip6_fb_tunnel_dev)) 805 goto done; 806 dev = t->dev; 807 } 808 unregister_netdevice(dev); 809 err = 0; 810 break; 811 812 default: 813 err = -EINVAL; 814 } 815 816 done: 817 return err; 818 } 819 820 static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev) 821 { 822 return &(((struct ip_tunnel*)netdev_priv(dev))->stat); 823 } 824 825 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 826 { 827 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 828 return -EINVAL; 829 dev->mtu = new_mtu; 830 return 0; 831 } 832 833 static void ipip6_tunnel_setup(struct net_device *dev) 834 { 835 dev->uninit = ipip6_tunnel_uninit; 836 dev->destructor = free_netdev; 837 dev->hard_start_xmit = ipip6_tunnel_xmit; 838 dev->get_stats = ipip6_tunnel_get_stats; 839 dev->do_ioctl = ipip6_tunnel_ioctl; 840 dev->change_mtu = ipip6_tunnel_change_mtu; 841 842 dev->type = ARPHRD_SIT; 843 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 844 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 845 dev->flags = IFF_NOARP; 846 dev->iflink = 0; 847 dev->addr_len = 4; 848 } 849 850 static int ipip6_tunnel_init(struct net_device *dev) 851 { 852 struct ip_tunnel *tunnel; 853 854 tunnel = netdev_priv(dev); 855 856 tunnel->dev = dev; 857 strcpy(tunnel->parms.name, dev->name); 858 859 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 860 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 861 862 ipip6_tunnel_bind_dev(dev); 863 864 return 0; 865 } 866 867 static int __init ipip6_fb_tunnel_init(struct net_device *dev) 868 { 869 struct ip_tunnel *tunnel = netdev_priv(dev); 870 struct iphdr *iph = &tunnel->parms.iph; 871 872 tunnel->dev = dev; 873 strcpy(tunnel->parms.name, dev->name); 874 875 iph->version = 4; 876 iph->protocol = IPPROTO_IPV6; 877 iph->ihl = 5; 878 iph->ttl = 64; 879 880 dev_hold(dev); 881 tunnels_wc[0] = tunnel; 882 return 0; 883 } 884 885 static struct xfrm_tunnel sit_handler = { 886 .handler = ipip6_rcv, 887 .err_handler = ipip6_err, 888 .priority = 1, 889 }; 890 891 static void __exit sit_destroy_tunnels(void) 892 { 893 int prio; 894 895 for (prio = 1; prio < 4; prio++) { 896 int h; 897 for (h = 0; h < HASH_SIZE; h++) { 898 struct ip_tunnel *t; 899 while ((t = tunnels[prio][h]) != NULL) 900 unregister_netdevice(t->dev); 901 } 902 } 903 } 904 905 static void __exit sit_cleanup(void) 906 { 907 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 908 909 rtnl_lock(); 910 sit_destroy_tunnels(); 911 unregister_netdevice(ipip6_fb_tunnel_dev); 912 rtnl_unlock(); 913 } 914 915 static int __init sit_init(void) 916 { 917 int err; 918 919 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 920 921 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) { 922 printk(KERN_INFO "sit init: Can't add protocol\n"); 923 return -EAGAIN; 924 } 925 926 ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 927 ipip6_tunnel_setup); 928 if (!ipip6_fb_tunnel_dev) { 929 err = -ENOMEM; 930 goto err1; 931 } 932 933 ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init; 934 935 if ((err = register_netdev(ipip6_fb_tunnel_dev))) 936 goto err2; 937 938 out: 939 return err; 940 err2: 941 free_netdev(ipip6_fb_tunnel_dev); 942 err1: 943 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 944 goto out; 945 } 946 947 module_init(sit_init); 948 module_exit(sit_cleanup); 949 MODULE_LICENSE("GPL"); 950 MODULE_ALIAS("sit0"); 951