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 sprintf(name, "sit%%d"); 169 170 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 171 if (dev == NULL) 172 return NULL; 173 174 if (strchr(name, '%')) { 175 if (dev_alloc_name(dev, name) < 0) 176 goto failed_free; 177 } 178 179 nt = netdev_priv(dev); 180 dev->init = ipip6_tunnel_init; 181 nt->parms = *parms; 182 183 if (parms->i_flags & SIT_ISATAP) 184 dev->priv_flags |= IFF_ISATAP; 185 186 if (register_netdevice(dev) < 0) 187 goto failed_free; 188 189 dev_hold(dev); 190 191 ipip6_tunnel_link(nt); 192 return nt; 193 194 failed_free: 195 free_netdev(dev); 196 failed: 197 return NULL; 198 } 199 200 static void ipip6_tunnel_uninit(struct net_device *dev) 201 { 202 if (dev == ipip6_fb_tunnel_dev) { 203 write_lock_bh(&ipip6_lock); 204 tunnels_wc[0] = NULL; 205 write_unlock_bh(&ipip6_lock); 206 dev_put(dev); 207 } else { 208 ipip6_tunnel_unlink(netdev_priv(dev)); 209 dev_put(dev); 210 } 211 } 212 213 214 static int ipip6_err(struct sk_buff *skb, u32 info) 215 { 216 #ifndef I_WISH_WORLD_WERE_PERFECT 217 218 /* It is not :-( All the routers (except for Linux) return only 219 8 bytes of packet payload. It means, that precise relaying of 220 ICMP in the real Internet is absolutely infeasible. 221 */ 222 struct iphdr *iph = (struct iphdr*)skb->data; 223 const int type = icmp_hdr(skb)->type; 224 const int code = icmp_hdr(skb)->code; 225 struct ip_tunnel *t; 226 int err; 227 228 switch (type) { 229 default: 230 case ICMP_PARAMETERPROB: 231 return 0; 232 233 case ICMP_DEST_UNREACH: 234 switch (code) { 235 case ICMP_SR_FAILED: 236 case ICMP_PORT_UNREACH: 237 /* Impossible event. */ 238 return 0; 239 case ICMP_FRAG_NEEDED: 240 /* Soft state for pmtu is maintained by IP core. */ 241 return 0; 242 default: 243 /* All others are translated to HOST_UNREACH. 244 rfc2003 contains "deep thoughts" about NET_UNREACH, 245 I believe they are just ether pollution. --ANK 246 */ 247 break; 248 } 249 break; 250 case ICMP_TIME_EXCEEDED: 251 if (code != ICMP_EXC_TTL) 252 return 0; 253 break; 254 } 255 256 err = -ENOENT; 257 258 read_lock(&ipip6_lock); 259 t = ipip6_tunnel_lookup(iph->daddr, iph->saddr); 260 if (t == NULL || t->parms.iph.daddr == 0) 261 goto out; 262 263 err = 0; 264 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 265 goto out; 266 267 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) 268 t->err_count++; 269 else 270 t->err_count = 1; 271 t->err_time = jiffies; 272 out: 273 read_unlock(&ipip6_lock); 274 return err; 275 #else 276 struct iphdr *iph = (struct iphdr*)dp; 277 int hlen = iph->ihl<<2; 278 struct ipv6hdr *iph6; 279 const int type = icmp_hdr(skb)->type; 280 const int code = icmp_hdr(skb)->code; 281 int rel_type = 0; 282 int rel_code = 0; 283 int rel_info = 0; 284 struct sk_buff *skb2; 285 struct rt6_info *rt6i; 286 287 if (len < hlen + sizeof(struct ipv6hdr)) 288 return; 289 iph6 = (struct ipv6hdr*)(dp + hlen); 290 291 switch (type) { 292 default: 293 return; 294 case ICMP_PARAMETERPROB: 295 if (icmp_hdr(skb)->un.gateway < hlen) 296 return; 297 298 /* So... This guy found something strange INSIDE encapsulated 299 packet. Well, he is fool, but what can we do ? 300 */ 301 rel_type = ICMPV6_PARAMPROB; 302 rel_info = icmp_hdr(skb)->un.gateway - hlen; 303 break; 304 305 case ICMP_DEST_UNREACH: 306 switch (code) { 307 case ICMP_SR_FAILED: 308 case ICMP_PORT_UNREACH: 309 /* Impossible event. */ 310 return; 311 case ICMP_FRAG_NEEDED: 312 /* Too complicated case ... */ 313 return; 314 default: 315 /* All others are translated to HOST_UNREACH. 316 rfc2003 contains "deep thoughts" about NET_UNREACH, 317 I believe, it is just ether pollution. --ANK 318 */ 319 rel_type = ICMPV6_DEST_UNREACH; 320 rel_code = ICMPV6_ADDR_UNREACH; 321 break; 322 } 323 break; 324 case ICMP_TIME_EXCEEDED: 325 if (code != ICMP_EXC_TTL) 326 return; 327 rel_type = ICMPV6_TIME_EXCEED; 328 rel_code = ICMPV6_EXC_HOPLIMIT; 329 break; 330 } 331 332 /* Prepare fake skb to feed it to icmpv6_send */ 333 skb2 = skb_clone(skb, GFP_ATOMIC); 334 if (skb2 == NULL) 335 return 0; 336 dst_release(skb2->dst); 337 skb2->dst = NULL; 338 skb_pull(skb2, skb->data - (u8*)iph6); 339 skb_reset_network_header(skb2); 340 341 /* Try to guess incoming interface */ 342 rt6i = rt6_lookup(&iph6->saddr, NULL, NULL, 0); 343 if (rt6i && rt6i->rt6i_dev) { 344 skb2->dev = rt6i->rt6i_dev; 345 346 rt6i = rt6_lookup(&iph6->daddr, &iph6->saddr, NULL, 0); 347 348 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) { 349 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev); 350 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) { 351 rel_type = ICMPV6_DEST_UNREACH; 352 rel_code = ICMPV6_ADDR_UNREACH; 353 } 354 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 355 } 356 } 357 kfree_skb(skb2); 358 return 0; 359 #endif 360 } 361 362 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 363 { 364 if (INET_ECN_is_ce(iph->tos)) 365 IP6_ECN_set_ce(ipv6_hdr(skb)); 366 } 367 368 /* ISATAP (RFC4214) - check source address */ 369 static int 370 isatap_srcok(struct sk_buff *skb, struct iphdr *iph, struct net_device *dev) 371 { 372 struct neighbour *neigh; 373 struct dst_entry *dst; 374 struct rt6_info *rt; 375 struct flowi fl; 376 struct in6_addr *addr6; 377 struct in6_addr rtr; 378 struct ipv6hdr *iph6; 379 int ok = 0; 380 381 /* from onlink default router */ 382 ipv6_addr_set(&rtr, htonl(0xFE800000), 0, 0, 0); 383 ipv6_isatap_eui64(rtr.s6_addr + 8, iph->saddr); 384 if ((rt = rt6_get_dflt_router(&rtr, dev))) { 385 dst_release(&rt->u.dst); 386 return 1; 387 } 388 389 iph6 = ipv6_hdr(skb); 390 memset(&fl, 0, sizeof(fl)); 391 fl.proto = iph6->nexthdr; 392 ipv6_addr_copy(&fl.fl6_dst, &iph6->saddr); 393 fl.oif = dev->ifindex; 394 security_skb_classify_flow(skb, &fl); 395 396 dst = ip6_route_output(NULL, &fl); 397 if (!dst->error && (dst->dev == dev) && (neigh = dst->neighbour)) { 398 399 addr6 = (struct in6_addr*)&neigh->primary_key; 400 401 /* from correct previous hop */ 402 if (ipv6_addr_is_isatap(addr6) && 403 (addr6->s6_addr32[3] == iph->saddr)) 404 ok = 1; 405 } 406 dst_release(dst); 407 return ok; 408 } 409 410 static int ipip6_rcv(struct sk_buff *skb) 411 { 412 struct iphdr *iph; 413 struct ip_tunnel *tunnel; 414 415 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 416 goto out; 417 418 iph = ip_hdr(skb); 419 420 read_lock(&ipip6_lock); 421 if ((tunnel = ipip6_tunnel_lookup(iph->saddr, iph->daddr)) != NULL) { 422 secpath_reset(skb); 423 skb->mac_header = skb->network_header; 424 skb_reset_network_header(skb); 425 IPCB(skb)->flags = 0; 426 skb->protocol = htons(ETH_P_IPV6); 427 skb->pkt_type = PACKET_HOST; 428 429 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 430 !isatap_srcok(skb, iph, tunnel->dev)) { 431 tunnel->stat.rx_errors++; 432 read_unlock(&ipip6_lock); 433 kfree_skb(skb); 434 return 0; 435 } 436 tunnel->stat.rx_packets++; 437 tunnel->stat.rx_bytes += skb->len; 438 skb->dev = tunnel->dev; 439 dst_release(skb->dst); 440 skb->dst = NULL; 441 nf_reset(skb); 442 ipip6_ecn_decapsulate(iph, skb); 443 netif_rx(skb); 444 read_unlock(&ipip6_lock); 445 return 0; 446 } 447 448 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 449 kfree_skb(skb); 450 read_unlock(&ipip6_lock); 451 out: 452 return 0; 453 } 454 455 /* Returns the embedded IPv4 address if the IPv6 address 456 comes from 6to4 (RFC 3056) addr space */ 457 458 static inline __be32 try_6to4(struct in6_addr *v6dst) 459 { 460 __be32 dst = 0; 461 462 if (v6dst->s6_addr16[0] == htons(0x2002)) { 463 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 464 memcpy(&dst, &v6dst->s6_addr16[1], 4); 465 } 466 return dst; 467 } 468 469 /* 470 * This function assumes it is being called from dev_queue_xmit() 471 * and that skb is filled properly by that function. 472 */ 473 474 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 475 { 476 struct ip_tunnel *tunnel = netdev_priv(dev); 477 struct net_device_stats *stats = &tunnel->stat; 478 struct iphdr *tiph = &tunnel->parms.iph; 479 struct ipv6hdr *iph6 = ipv6_hdr(skb); 480 u8 tos = tunnel->parms.iph.tos; 481 struct rtable *rt; /* Route to the other host */ 482 struct net_device *tdev; /* Device to other host */ 483 struct iphdr *iph; /* Our new IP header */ 484 unsigned int max_headroom; /* The extra header space needed */ 485 __be32 dst = tiph->daddr; 486 int mtu; 487 struct in6_addr *addr6; 488 int addr_type; 489 490 if (tunnel->recursion++) { 491 tunnel->stat.collisions++; 492 goto tx_error; 493 } 494 495 if (skb->protocol != htons(ETH_P_IPV6)) 496 goto tx_error; 497 498 /* ISATAP (RFC4214) - must come before 6to4 */ 499 if (dev->priv_flags & IFF_ISATAP) { 500 struct neighbour *neigh = NULL; 501 502 if (skb->dst) 503 neigh = skb->dst->neighbour; 504 505 if (neigh == NULL) { 506 if (net_ratelimit()) 507 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 508 goto tx_error; 509 } 510 511 addr6 = (struct in6_addr*)&neigh->primary_key; 512 addr_type = ipv6_addr_type(addr6); 513 514 if ((addr_type & IPV6_ADDR_UNICAST) && 515 ipv6_addr_is_isatap(addr6)) 516 dst = addr6->s6_addr32[3]; 517 else 518 goto tx_error; 519 } 520 521 if (!dst) 522 dst = try_6to4(&iph6->daddr); 523 524 if (!dst) { 525 struct neighbour *neigh = NULL; 526 527 if (skb->dst) 528 neigh = skb->dst->neighbour; 529 530 if (neigh == NULL) { 531 if (net_ratelimit()) 532 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 533 goto tx_error; 534 } 535 536 addr6 = (struct in6_addr*)&neigh->primary_key; 537 addr_type = ipv6_addr_type(addr6); 538 539 if (addr_type == IPV6_ADDR_ANY) { 540 addr6 = &ipv6_hdr(skb)->daddr; 541 addr_type = ipv6_addr_type(addr6); 542 } 543 544 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 545 goto tx_error_icmp; 546 547 dst = addr6->s6_addr32[3]; 548 } 549 550 { 551 struct flowi fl = { .nl_u = { .ip4_u = 552 { .daddr = dst, 553 .saddr = tiph->saddr, 554 .tos = RT_TOS(tos) } }, 555 .oif = tunnel->parms.link, 556 .proto = IPPROTO_IPV6 }; 557 if (ip_route_output_key(&init_net, &rt, &fl)) { 558 tunnel->stat.tx_carrier_errors++; 559 goto tx_error_icmp; 560 } 561 } 562 if (rt->rt_type != RTN_UNICAST) { 563 ip_rt_put(rt); 564 tunnel->stat.tx_carrier_errors++; 565 goto tx_error_icmp; 566 } 567 tdev = rt->u.dst.dev; 568 569 if (tdev == dev) { 570 ip_rt_put(rt); 571 tunnel->stat.collisions++; 572 goto tx_error; 573 } 574 575 if (tiph->frag_off) 576 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 577 else 578 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; 579 580 if (mtu < 68) { 581 tunnel->stat.collisions++; 582 ip_rt_put(rt); 583 goto tx_error; 584 } 585 if (mtu < IPV6_MIN_MTU) 586 mtu = IPV6_MIN_MTU; 587 if (tunnel->parms.iph.daddr && skb->dst) 588 skb->dst->ops->update_pmtu(skb->dst, mtu); 589 590 if (skb->len > mtu) { 591 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 592 ip_rt_put(rt); 593 goto tx_error; 594 } 595 596 if (tunnel->err_count > 0) { 597 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { 598 tunnel->err_count--; 599 dst_link_failure(skb); 600 } else 601 tunnel->err_count = 0; 602 } 603 604 /* 605 * Okay, now see if we can stuff it in the buffer as-is. 606 */ 607 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 608 609 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 610 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 611 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 612 if (!new_skb) { 613 ip_rt_put(rt); 614 stats->tx_dropped++; 615 dev_kfree_skb(skb); 616 tunnel->recursion--; 617 return 0; 618 } 619 if (skb->sk) 620 skb_set_owner_w(new_skb, skb->sk); 621 dev_kfree_skb(skb); 622 skb = new_skb; 623 iph6 = ipv6_hdr(skb); 624 } 625 626 skb->transport_header = skb->network_header; 627 skb_push(skb, sizeof(struct iphdr)); 628 skb_reset_network_header(skb); 629 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 630 IPCB(skb)->flags = 0; 631 dst_release(skb->dst); 632 skb->dst = &rt->u.dst; 633 634 /* 635 * Push down and install the IPIP header. 636 */ 637 638 iph = ip_hdr(skb); 639 iph->version = 4; 640 iph->ihl = sizeof(struct iphdr)>>2; 641 if (mtu > IPV6_MIN_MTU) 642 iph->frag_off = htons(IP_DF); 643 else 644 iph->frag_off = 0; 645 646 iph->protocol = IPPROTO_IPV6; 647 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 648 iph->daddr = rt->rt_dst; 649 iph->saddr = rt->rt_src; 650 651 if ((iph->ttl = tiph->ttl) == 0) 652 iph->ttl = iph6->hop_limit; 653 654 nf_reset(skb); 655 656 IPTUNNEL_XMIT(); 657 tunnel->recursion--; 658 return 0; 659 660 tx_error_icmp: 661 dst_link_failure(skb); 662 tx_error: 663 stats->tx_errors++; 664 dev_kfree_skb(skb); 665 tunnel->recursion--; 666 return 0; 667 } 668 669 static void ipip6_tunnel_bind_dev(struct net_device *dev) 670 { 671 struct net_device *tdev = NULL; 672 struct ip_tunnel *tunnel; 673 struct iphdr *iph; 674 675 tunnel = netdev_priv(dev); 676 iph = &tunnel->parms.iph; 677 678 if (iph->daddr) { 679 struct flowi fl = { .nl_u = { .ip4_u = 680 { .daddr = iph->daddr, 681 .saddr = iph->saddr, 682 .tos = RT_TOS(iph->tos) } }, 683 .oif = tunnel->parms.link, 684 .proto = IPPROTO_IPV6 }; 685 struct rtable *rt; 686 if (!ip_route_output_key(&init_net, &rt, &fl)) { 687 tdev = rt->u.dst.dev; 688 ip_rt_put(rt); 689 } 690 dev->flags |= IFF_POINTOPOINT; 691 } 692 693 if (!tdev && tunnel->parms.link) 694 tdev = __dev_get_by_index(&init_net, tunnel->parms.link); 695 696 if (tdev) { 697 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 698 dev->mtu = tdev->mtu - sizeof(struct iphdr); 699 if (dev->mtu < IPV6_MIN_MTU) 700 dev->mtu = IPV6_MIN_MTU; 701 } 702 dev->iflink = tunnel->parms.link; 703 } 704 705 static int 706 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 707 { 708 int err = 0; 709 struct ip_tunnel_parm p; 710 struct ip_tunnel *t; 711 712 switch (cmd) { 713 case SIOCGETTUNNEL: 714 t = NULL; 715 if (dev == ipip6_fb_tunnel_dev) { 716 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 717 err = -EFAULT; 718 break; 719 } 720 t = ipip6_tunnel_locate(&p, 0); 721 } 722 if (t == NULL) 723 t = netdev_priv(dev); 724 memcpy(&p, &t->parms, sizeof(p)); 725 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 726 err = -EFAULT; 727 break; 728 729 case SIOCADDTUNNEL: 730 case SIOCCHGTUNNEL: 731 err = -EPERM; 732 if (!capable(CAP_NET_ADMIN)) 733 goto done; 734 735 err = -EFAULT; 736 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 737 goto done; 738 739 err = -EINVAL; 740 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 741 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 742 goto done; 743 if (p.iph.ttl) 744 p.iph.frag_off |= htons(IP_DF); 745 746 t = ipip6_tunnel_locate(&p, cmd == SIOCADDTUNNEL); 747 748 if (dev != ipip6_fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 749 if (t != NULL) { 750 if (t->dev != dev) { 751 err = -EEXIST; 752 break; 753 } 754 } else { 755 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 756 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 757 err = -EINVAL; 758 break; 759 } 760 t = netdev_priv(dev); 761 ipip6_tunnel_unlink(t); 762 t->parms.iph.saddr = p.iph.saddr; 763 t->parms.iph.daddr = p.iph.daddr; 764 memcpy(dev->dev_addr, &p.iph.saddr, 4); 765 memcpy(dev->broadcast, &p.iph.daddr, 4); 766 ipip6_tunnel_link(t); 767 netdev_state_change(dev); 768 } 769 } 770 771 if (t) { 772 err = 0; 773 if (cmd == SIOCCHGTUNNEL) { 774 t->parms.iph.ttl = p.iph.ttl; 775 t->parms.iph.tos = p.iph.tos; 776 if (t->parms.link != p.link) { 777 t->parms.link = p.link; 778 ipip6_tunnel_bind_dev(dev); 779 netdev_state_change(dev); 780 } 781 } 782 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 783 err = -EFAULT; 784 } else 785 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 786 break; 787 788 case SIOCDELTUNNEL: 789 err = -EPERM; 790 if (!capable(CAP_NET_ADMIN)) 791 goto done; 792 793 if (dev == ipip6_fb_tunnel_dev) { 794 err = -EFAULT; 795 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 796 goto done; 797 err = -ENOENT; 798 if ((t = ipip6_tunnel_locate(&p, 0)) == NULL) 799 goto done; 800 err = -EPERM; 801 if (t == netdev_priv(ipip6_fb_tunnel_dev)) 802 goto done; 803 dev = t->dev; 804 } 805 unregister_netdevice(dev); 806 err = 0; 807 break; 808 809 default: 810 err = -EINVAL; 811 } 812 813 done: 814 return err; 815 } 816 817 static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev) 818 { 819 return &(((struct ip_tunnel*)netdev_priv(dev))->stat); 820 } 821 822 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 823 { 824 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 825 return -EINVAL; 826 dev->mtu = new_mtu; 827 return 0; 828 } 829 830 static void ipip6_tunnel_setup(struct net_device *dev) 831 { 832 dev->uninit = ipip6_tunnel_uninit; 833 dev->destructor = free_netdev; 834 dev->hard_start_xmit = ipip6_tunnel_xmit; 835 dev->get_stats = ipip6_tunnel_get_stats; 836 dev->do_ioctl = ipip6_tunnel_ioctl; 837 dev->change_mtu = ipip6_tunnel_change_mtu; 838 839 dev->type = ARPHRD_SIT; 840 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 841 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 842 dev->flags = IFF_NOARP; 843 dev->iflink = 0; 844 dev->addr_len = 4; 845 } 846 847 static int ipip6_tunnel_init(struct net_device *dev) 848 { 849 struct ip_tunnel *tunnel; 850 851 tunnel = netdev_priv(dev); 852 853 tunnel->dev = dev; 854 strcpy(tunnel->parms.name, dev->name); 855 856 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 857 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 858 859 ipip6_tunnel_bind_dev(dev); 860 861 return 0; 862 } 863 864 static int __init ipip6_fb_tunnel_init(struct net_device *dev) 865 { 866 struct ip_tunnel *tunnel = netdev_priv(dev); 867 struct iphdr *iph = &tunnel->parms.iph; 868 869 tunnel->dev = dev; 870 strcpy(tunnel->parms.name, dev->name); 871 872 iph->version = 4; 873 iph->protocol = IPPROTO_IPV6; 874 iph->ihl = 5; 875 iph->ttl = 64; 876 877 dev_hold(dev); 878 tunnels_wc[0] = tunnel; 879 return 0; 880 } 881 882 static struct xfrm_tunnel sit_handler = { 883 .handler = ipip6_rcv, 884 .err_handler = ipip6_err, 885 .priority = 1, 886 }; 887 888 static void __exit sit_destroy_tunnels(void) 889 { 890 int prio; 891 892 for (prio = 1; prio < 4; prio++) { 893 int h; 894 for (h = 0; h < HASH_SIZE; h++) { 895 struct ip_tunnel *t; 896 while ((t = tunnels[prio][h]) != NULL) 897 unregister_netdevice(t->dev); 898 } 899 } 900 } 901 902 static void __exit sit_cleanup(void) 903 { 904 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 905 906 rtnl_lock(); 907 sit_destroy_tunnels(); 908 unregister_netdevice(ipip6_fb_tunnel_dev); 909 rtnl_unlock(); 910 } 911 912 static int __init sit_init(void) 913 { 914 int err; 915 916 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 917 918 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) { 919 printk(KERN_INFO "sit init: Can't add protocol\n"); 920 return -EAGAIN; 921 } 922 923 ipip6_fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 924 ipip6_tunnel_setup); 925 if (!ipip6_fb_tunnel_dev) { 926 err = -ENOMEM; 927 goto err1; 928 } 929 930 ipip6_fb_tunnel_dev->init = ipip6_fb_tunnel_init; 931 932 if ((err = register_netdev(ipip6_fb_tunnel_dev))) 933 goto err2; 934 935 out: 936 return err; 937 err2: 938 free_netdev(ipip6_fb_tunnel_dev); 939 err1: 940 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 941 goto out; 942 } 943 944 module_init(sit_init); 945 module_exit(sit_cleanup); 946 MODULE_LICENSE("GPL"); 947 MODULE_ALIAS("sit0"); 948