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 <asm/uaccess.h> 32 #include <linux/init.h> 33 #include <linux/netfilter_ipv4.h> 34 #include <linux/if_ether.h> 35 36 #include <net/sock.h> 37 #include <net/snmp.h> 38 39 #include <net/ipv6.h> 40 #include <net/protocol.h> 41 #include <net/transp_v6.h> 42 #include <net/ip6_fib.h> 43 #include <net/ip6_route.h> 44 #include <net/ndisc.h> 45 #include <net/addrconf.h> 46 #include <net/ip.h> 47 #include <net/udp.h> 48 #include <net/icmp.h> 49 #include <net/ipip.h> 50 #include <net/inet_ecn.h> 51 #include <net/xfrm.h> 52 #include <net/dsfield.h> 53 #include <net/net_namespace.h> 54 #include <net/netns/generic.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 void ipip6_fb_tunnel_init(struct net_device *dev); 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; 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 static DEFINE_RWLOCK(ipip6_lock); 81 82 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, 83 struct net_device *dev, __be32 remote, __be32 local) 84 { 85 unsigned h0 = HASH(remote); 86 unsigned h1 = HASH(local); 87 struct ip_tunnel *t; 88 struct sit_net *sitn = net_generic(net, sit_net_id); 89 90 for (t = sitn->tunnels_r_l[h0^h1]; t; t = t->next) { 91 if (local == t->parms.iph.saddr && 92 remote == t->parms.iph.daddr && 93 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 94 (t->dev->flags & IFF_UP)) 95 return t; 96 } 97 for (t = sitn->tunnels_r[h0]; t; t = t->next) { 98 if (remote == t->parms.iph.daddr && 99 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 100 (t->dev->flags & IFF_UP)) 101 return t; 102 } 103 for (t = sitn->tunnels_l[h1]; t; t = t->next) { 104 if (local == t->parms.iph.saddr && 105 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 106 (t->dev->flags & IFF_UP)) 107 return t; 108 } 109 t = sitn->tunnels_wc[0]; 110 if ((t != NULL) && (t->dev->flags & IFF_UP)) 111 return t; 112 return NULL; 113 } 114 115 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn, 116 struct ip_tunnel_parm *parms) 117 { 118 __be32 remote = parms->iph.daddr; 119 __be32 local = parms->iph.saddr; 120 unsigned h = 0; 121 int prio = 0; 122 123 if (remote) { 124 prio |= 2; 125 h ^= HASH(remote); 126 } 127 if (local) { 128 prio |= 1; 129 h ^= HASH(local); 130 } 131 return &sitn->tunnels[prio][h]; 132 } 133 134 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn, 135 struct ip_tunnel *t) 136 { 137 return __ipip6_bucket(sitn, &t->parms); 138 } 139 140 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 141 { 142 struct ip_tunnel **tp; 143 144 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) { 145 if (t == *tp) { 146 write_lock_bh(&ipip6_lock); 147 *tp = t->next; 148 write_unlock_bh(&ipip6_lock); 149 break; 150 } 151 } 152 } 153 154 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 155 { 156 struct ip_tunnel **tp = ipip6_bucket(sitn, t); 157 158 t->next = *tp; 159 write_lock_bh(&ipip6_lock); 160 *tp = t; 161 write_unlock_bh(&ipip6_lock); 162 } 163 164 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net, 165 struct ip_tunnel_parm *parms, int create) 166 { 167 __be32 remote = parms->iph.daddr; 168 __be32 local = parms->iph.saddr; 169 struct ip_tunnel *t, **tp, *nt; 170 struct net_device *dev; 171 char name[IFNAMSIZ]; 172 struct sit_net *sitn = net_generic(net, sit_net_id); 173 174 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) { 175 if (local == t->parms.iph.saddr && 176 remote == t->parms.iph.daddr && 177 parms->link == t->parms.link) { 178 if (create) 179 return NULL; 180 else 181 return t; 182 } 183 } 184 if (!create) 185 goto failed; 186 187 if (parms->name[0]) 188 strlcpy(name, parms->name, IFNAMSIZ); 189 else 190 sprintf(name, "sit%%d"); 191 192 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 193 if (dev == NULL) 194 return NULL; 195 196 dev_net_set(dev, net); 197 198 if (strchr(name, '%')) { 199 if (dev_alloc_name(dev, name) < 0) 200 goto failed_free; 201 } 202 203 nt = netdev_priv(dev); 204 205 nt->parms = *parms; 206 ipip6_tunnel_init(dev); 207 208 if (parms->i_flags & SIT_ISATAP) 209 dev->priv_flags |= IFF_ISATAP; 210 211 if (register_netdevice(dev) < 0) 212 goto failed_free; 213 214 dev_hold(dev); 215 216 ipip6_tunnel_link(sitn, nt); 217 return nt; 218 219 failed_free: 220 free_netdev(dev); 221 failed: 222 return NULL; 223 } 224 225 static struct ip_tunnel_prl_entry * 226 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 227 { 228 struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL; 229 230 for (p = t->prl; p; p = p->next) 231 if (p->addr == addr) 232 break; 233 return p; 234 235 } 236 237 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 238 struct ip_tunnel_prl __user *a) 239 { 240 struct ip_tunnel_prl kprl, *kp; 241 struct ip_tunnel_prl_entry *prl; 242 unsigned int cmax, c = 0, ca, len; 243 int ret = 0; 244 245 if (copy_from_user(&kprl, a, sizeof(kprl))) 246 return -EFAULT; 247 cmax = kprl.datalen / sizeof(kprl); 248 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 249 cmax = 1; 250 251 /* For simple GET or for root users, 252 * we try harder to allocate. 253 */ 254 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 255 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 256 NULL; 257 258 read_lock(&ipip6_lock); 259 260 ca = t->prl_count < cmax ? t->prl_count : cmax; 261 262 if (!kp) { 263 /* We don't try hard to allocate much memory for 264 * non-root users. 265 * For root users, retry allocating enough memory for 266 * the answer. 267 */ 268 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 269 if (!kp) { 270 ret = -ENOMEM; 271 goto out; 272 } 273 } 274 275 c = 0; 276 for (prl = t->prl; prl; prl = prl->next) { 277 if (c >= cmax) 278 break; 279 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 280 continue; 281 kp[c].addr = prl->addr; 282 kp[c].flags = prl->flags; 283 c++; 284 if (kprl.addr != htonl(INADDR_ANY)) 285 break; 286 } 287 out: 288 read_unlock(&ipip6_lock); 289 290 len = sizeof(*kp) * c; 291 ret = 0; 292 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 293 ret = -EFAULT; 294 295 kfree(kp); 296 297 return ret; 298 } 299 300 static int 301 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 302 { 303 struct ip_tunnel_prl_entry *p; 304 int err = 0; 305 306 if (a->addr == htonl(INADDR_ANY)) 307 return -EINVAL; 308 309 write_lock(&ipip6_lock); 310 311 for (p = t->prl; p; p = p->next) { 312 if (p->addr == a->addr) { 313 if (chg) 314 goto update; 315 err = -EEXIST; 316 goto out; 317 } 318 } 319 320 if (chg) { 321 err = -ENXIO; 322 goto out; 323 } 324 325 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 326 if (!p) { 327 err = -ENOBUFS; 328 goto out; 329 } 330 331 p->next = t->prl; 332 t->prl = p; 333 t->prl_count++; 334 update: 335 p->addr = a->addr; 336 p->flags = a->flags; 337 out: 338 write_unlock(&ipip6_lock); 339 return err; 340 } 341 342 static int 343 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 344 { 345 struct ip_tunnel_prl_entry *x, **p; 346 int err = 0; 347 348 write_lock(&ipip6_lock); 349 350 if (a && a->addr != htonl(INADDR_ANY)) { 351 for (p = &t->prl; *p; p = &(*p)->next) { 352 if ((*p)->addr == a->addr) { 353 x = *p; 354 *p = x->next; 355 kfree(x); 356 t->prl_count--; 357 goto out; 358 } 359 } 360 err = -ENXIO; 361 } else { 362 while (t->prl) { 363 x = t->prl; 364 t->prl = t->prl->next; 365 kfree(x); 366 t->prl_count--; 367 } 368 } 369 out: 370 write_unlock(&ipip6_lock); 371 return err; 372 } 373 374 static int 375 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 376 { 377 struct ip_tunnel_prl_entry *p; 378 int ok = 1; 379 380 read_lock(&ipip6_lock); 381 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 382 if (p) { 383 if (p->flags & PRL_DEFAULT) 384 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 385 else 386 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 387 } else { 388 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 389 if (ipv6_addr_is_isatap(addr6) && 390 (addr6->s6_addr32[3] == iph->saddr) && 391 ipv6_chk_prefix(addr6, t->dev)) 392 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 393 else 394 ok = 0; 395 } 396 read_unlock(&ipip6_lock); 397 return ok; 398 } 399 400 static void ipip6_tunnel_uninit(struct net_device *dev) 401 { 402 struct net *net = dev_net(dev); 403 struct sit_net *sitn = net_generic(net, sit_net_id); 404 405 if (dev == sitn->fb_tunnel_dev) { 406 write_lock_bh(&ipip6_lock); 407 sitn->tunnels_wc[0] = NULL; 408 write_unlock_bh(&ipip6_lock); 409 dev_put(dev); 410 } else { 411 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 412 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 413 dev_put(dev); 414 } 415 } 416 417 418 static int ipip6_err(struct sk_buff *skb, u32 info) 419 { 420 421 /* All the routers (except for Linux) return only 422 8 bytes of packet payload. It means, that precise relaying of 423 ICMP in the real Internet is absolutely infeasible. 424 */ 425 struct iphdr *iph = (struct iphdr*)skb->data; 426 const int type = icmp_hdr(skb)->type; 427 const int code = icmp_hdr(skb)->code; 428 struct ip_tunnel *t; 429 int err; 430 431 switch (type) { 432 default: 433 case ICMP_PARAMETERPROB: 434 return 0; 435 436 case ICMP_DEST_UNREACH: 437 switch (code) { 438 case ICMP_SR_FAILED: 439 case ICMP_PORT_UNREACH: 440 /* Impossible event. */ 441 return 0; 442 case ICMP_FRAG_NEEDED: 443 /* Soft state for pmtu is maintained by IP core. */ 444 return 0; 445 default: 446 /* All others are translated to HOST_UNREACH. 447 rfc2003 contains "deep thoughts" about NET_UNREACH, 448 I believe they are just ether pollution. --ANK 449 */ 450 break; 451 } 452 break; 453 case ICMP_TIME_EXCEEDED: 454 if (code != ICMP_EXC_TTL) 455 return 0; 456 break; 457 } 458 459 err = -ENOENT; 460 461 read_lock(&ipip6_lock); 462 t = ipip6_tunnel_lookup(dev_net(skb->dev), 463 skb->dev, 464 iph->daddr, 465 iph->saddr); 466 if (t == NULL || t->parms.iph.daddr == 0) 467 goto out; 468 469 err = 0; 470 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 471 goto out; 472 473 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 474 t->err_count++; 475 else 476 t->err_count = 1; 477 t->err_time = jiffies; 478 out: 479 read_unlock(&ipip6_lock); 480 return err; 481 } 482 483 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 484 { 485 if (INET_ECN_is_ce(iph->tos)) 486 IP6_ECN_set_ce(ipv6_hdr(skb)); 487 } 488 489 static int ipip6_rcv(struct sk_buff *skb) 490 { 491 struct iphdr *iph; 492 struct ip_tunnel *tunnel; 493 494 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 495 goto out; 496 497 iph = ip_hdr(skb); 498 499 read_lock(&ipip6_lock); 500 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 501 iph->saddr, iph->daddr); 502 if (tunnel != NULL) { 503 secpath_reset(skb); 504 skb->mac_header = skb->network_header; 505 skb_reset_network_header(skb); 506 IPCB(skb)->flags = 0; 507 skb->protocol = htons(ETH_P_IPV6); 508 skb->pkt_type = PACKET_HOST; 509 510 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 511 !isatap_chksrc(skb, iph, tunnel)) { 512 tunnel->dev->stats.rx_errors++; 513 read_unlock(&ipip6_lock); 514 kfree_skb(skb); 515 return 0; 516 } 517 tunnel->dev->stats.rx_packets++; 518 tunnel->dev->stats.rx_bytes += skb->len; 519 skb->dev = tunnel->dev; 520 skb_dst_drop(skb); 521 nf_reset(skb); 522 ipip6_ecn_decapsulate(iph, skb); 523 netif_rx(skb); 524 read_unlock(&ipip6_lock); 525 return 0; 526 } 527 528 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 529 read_unlock(&ipip6_lock); 530 out: 531 kfree_skb(skb); 532 return 0; 533 } 534 535 /* Returns the embedded IPv4 address if the IPv6 address 536 comes from 6to4 (RFC 3056) addr space */ 537 538 static inline __be32 try_6to4(struct in6_addr *v6dst) 539 { 540 __be32 dst = 0; 541 542 if (v6dst->s6_addr16[0] == htons(0x2002)) { 543 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 544 memcpy(&dst, &v6dst->s6_addr16[1], 4); 545 } 546 return dst; 547 } 548 549 /* 550 * This function assumes it is being called from dev_queue_xmit() 551 * and that skb is filled properly by that function. 552 */ 553 554 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 555 struct net_device *dev) 556 { 557 struct ip_tunnel *tunnel = netdev_priv(dev); 558 struct net_device_stats *stats = &tunnel->dev->stats; 559 struct iphdr *tiph = &tunnel->parms.iph; 560 struct ipv6hdr *iph6 = ipv6_hdr(skb); 561 u8 tos = tunnel->parms.iph.tos; 562 struct rtable *rt; /* Route to the other host */ 563 struct net_device *tdev; /* Device to other host */ 564 struct iphdr *iph; /* Our new IP header */ 565 unsigned int max_headroom; /* The extra header space needed */ 566 __be32 dst = tiph->daddr; 567 int mtu; 568 struct in6_addr *addr6; 569 int addr_type; 570 571 if (skb->protocol != htons(ETH_P_IPV6)) 572 goto tx_error; 573 574 /* ISATAP (RFC4214) - must come before 6to4 */ 575 if (dev->priv_flags & IFF_ISATAP) { 576 struct neighbour *neigh = NULL; 577 578 if (skb_dst(skb)) 579 neigh = skb_dst(skb)->neighbour; 580 581 if (neigh == NULL) { 582 if (net_ratelimit()) 583 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 584 goto tx_error; 585 } 586 587 addr6 = (struct in6_addr*)&neigh->primary_key; 588 addr_type = ipv6_addr_type(addr6); 589 590 if ((addr_type & IPV6_ADDR_UNICAST) && 591 ipv6_addr_is_isatap(addr6)) 592 dst = addr6->s6_addr32[3]; 593 else 594 goto tx_error; 595 } 596 597 if (!dst) 598 dst = try_6to4(&iph6->daddr); 599 600 if (!dst) { 601 struct neighbour *neigh = NULL; 602 603 if (skb_dst(skb)) 604 neigh = skb_dst(skb)->neighbour; 605 606 if (neigh == NULL) { 607 if (net_ratelimit()) 608 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 609 goto tx_error; 610 } 611 612 addr6 = (struct in6_addr*)&neigh->primary_key; 613 addr_type = ipv6_addr_type(addr6); 614 615 if (addr_type == IPV6_ADDR_ANY) { 616 addr6 = &ipv6_hdr(skb)->daddr; 617 addr_type = ipv6_addr_type(addr6); 618 } 619 620 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 621 goto tx_error_icmp; 622 623 dst = addr6->s6_addr32[3]; 624 } 625 626 { 627 struct flowi fl = { .nl_u = { .ip4_u = 628 { .daddr = dst, 629 .saddr = tiph->saddr, 630 .tos = RT_TOS(tos) } }, 631 .oif = tunnel->parms.link, 632 .proto = IPPROTO_IPV6 }; 633 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 634 stats->tx_carrier_errors++; 635 goto tx_error_icmp; 636 } 637 } 638 if (rt->rt_type != RTN_UNICAST) { 639 ip_rt_put(rt); 640 stats->tx_carrier_errors++; 641 goto tx_error_icmp; 642 } 643 tdev = rt->u.dst.dev; 644 645 if (tdev == dev) { 646 ip_rt_put(rt); 647 stats->collisions++; 648 goto tx_error; 649 } 650 651 if (tiph->frag_off) 652 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 653 else 654 mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; 655 656 if (mtu < 68) { 657 stats->collisions++; 658 ip_rt_put(rt); 659 goto tx_error; 660 } 661 if (mtu < IPV6_MIN_MTU) 662 mtu = IPV6_MIN_MTU; 663 if (tunnel->parms.iph.daddr && skb_dst(skb)) 664 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 665 666 if (skb->len > mtu) { 667 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 668 ip_rt_put(rt); 669 goto tx_error; 670 } 671 672 if (tunnel->err_count > 0) { 673 if (time_before(jiffies, 674 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 675 tunnel->err_count--; 676 dst_link_failure(skb); 677 } else 678 tunnel->err_count = 0; 679 } 680 681 /* 682 * Okay, now see if we can stuff it in the buffer as-is. 683 */ 684 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 685 686 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 687 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 688 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 689 if (!new_skb) { 690 ip_rt_put(rt); 691 stats->tx_dropped++; 692 dev_kfree_skb(skb); 693 return NETDEV_TX_OK; 694 } 695 if (skb->sk) 696 skb_set_owner_w(new_skb, skb->sk); 697 dev_kfree_skb(skb); 698 skb = new_skb; 699 iph6 = ipv6_hdr(skb); 700 } 701 702 skb->transport_header = skb->network_header; 703 skb_push(skb, sizeof(struct iphdr)); 704 skb_reset_network_header(skb); 705 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 706 IPCB(skb)->flags = 0; 707 skb_dst_drop(skb); 708 skb_dst_set(skb, &rt->u.dst); 709 710 /* 711 * Push down and install the IPIP header. 712 */ 713 714 iph = ip_hdr(skb); 715 iph->version = 4; 716 iph->ihl = sizeof(struct iphdr)>>2; 717 if (mtu > IPV6_MIN_MTU) 718 iph->frag_off = tiph->frag_off; 719 else 720 iph->frag_off = 0; 721 722 iph->protocol = IPPROTO_IPV6; 723 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 724 iph->daddr = rt->rt_dst; 725 iph->saddr = rt->rt_src; 726 727 if ((iph->ttl = tiph->ttl) == 0) 728 iph->ttl = iph6->hop_limit; 729 730 nf_reset(skb); 731 732 IPTUNNEL_XMIT(); 733 return NETDEV_TX_OK; 734 735 tx_error_icmp: 736 dst_link_failure(skb); 737 tx_error: 738 stats->tx_errors++; 739 dev_kfree_skb(skb); 740 return NETDEV_TX_OK; 741 } 742 743 static void ipip6_tunnel_bind_dev(struct net_device *dev) 744 { 745 struct net_device *tdev = NULL; 746 struct ip_tunnel *tunnel; 747 struct iphdr *iph; 748 749 tunnel = netdev_priv(dev); 750 iph = &tunnel->parms.iph; 751 752 if (iph->daddr) { 753 struct flowi fl = { .nl_u = { .ip4_u = 754 { .daddr = iph->daddr, 755 .saddr = iph->saddr, 756 .tos = RT_TOS(iph->tos) } }, 757 .oif = tunnel->parms.link, 758 .proto = IPPROTO_IPV6 }; 759 struct rtable *rt; 760 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 761 tdev = rt->u.dst.dev; 762 ip_rt_put(rt); 763 } 764 dev->flags |= IFF_POINTOPOINT; 765 } 766 767 if (!tdev && tunnel->parms.link) 768 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 769 770 if (tdev) { 771 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 772 dev->mtu = tdev->mtu - sizeof(struct iphdr); 773 if (dev->mtu < IPV6_MIN_MTU) 774 dev->mtu = IPV6_MIN_MTU; 775 } 776 dev->iflink = tunnel->parms.link; 777 } 778 779 static int 780 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 781 { 782 int err = 0; 783 struct ip_tunnel_parm p; 784 struct ip_tunnel_prl prl; 785 struct ip_tunnel *t; 786 struct net *net = dev_net(dev); 787 struct sit_net *sitn = net_generic(net, sit_net_id); 788 789 switch (cmd) { 790 case SIOCGETTUNNEL: 791 t = NULL; 792 if (dev == sitn->fb_tunnel_dev) { 793 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 794 err = -EFAULT; 795 break; 796 } 797 t = ipip6_tunnel_locate(net, &p, 0); 798 } 799 if (t == NULL) 800 t = netdev_priv(dev); 801 memcpy(&p, &t->parms, sizeof(p)); 802 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 803 err = -EFAULT; 804 break; 805 806 case SIOCADDTUNNEL: 807 case SIOCCHGTUNNEL: 808 err = -EPERM; 809 if (!capable(CAP_NET_ADMIN)) 810 goto done; 811 812 err = -EFAULT; 813 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 814 goto done; 815 816 err = -EINVAL; 817 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 818 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 819 goto done; 820 if (p.iph.ttl) 821 p.iph.frag_off |= htons(IP_DF); 822 823 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 824 825 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 826 if (t != NULL) { 827 if (t->dev != dev) { 828 err = -EEXIST; 829 break; 830 } 831 } else { 832 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 833 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 834 err = -EINVAL; 835 break; 836 } 837 t = netdev_priv(dev); 838 ipip6_tunnel_unlink(sitn, t); 839 t->parms.iph.saddr = p.iph.saddr; 840 t->parms.iph.daddr = p.iph.daddr; 841 memcpy(dev->dev_addr, &p.iph.saddr, 4); 842 memcpy(dev->broadcast, &p.iph.daddr, 4); 843 ipip6_tunnel_link(sitn, t); 844 netdev_state_change(dev); 845 } 846 } 847 848 if (t) { 849 err = 0; 850 if (cmd == SIOCCHGTUNNEL) { 851 t->parms.iph.ttl = p.iph.ttl; 852 t->parms.iph.tos = p.iph.tos; 853 if (t->parms.link != p.link) { 854 t->parms.link = p.link; 855 ipip6_tunnel_bind_dev(dev); 856 netdev_state_change(dev); 857 } 858 } 859 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 860 err = -EFAULT; 861 } else 862 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 863 break; 864 865 case SIOCDELTUNNEL: 866 err = -EPERM; 867 if (!capable(CAP_NET_ADMIN)) 868 goto done; 869 870 if (dev == sitn->fb_tunnel_dev) { 871 err = -EFAULT; 872 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 873 goto done; 874 err = -ENOENT; 875 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 876 goto done; 877 err = -EPERM; 878 if (t == netdev_priv(sitn->fb_tunnel_dev)) 879 goto done; 880 dev = t->dev; 881 } 882 unregister_netdevice(dev); 883 err = 0; 884 break; 885 886 case SIOCGETPRL: 887 err = -EINVAL; 888 if (dev == sitn->fb_tunnel_dev) 889 goto done; 890 err = -ENOENT; 891 if (!(t = netdev_priv(dev))) 892 goto done; 893 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 894 break; 895 896 case SIOCADDPRL: 897 case SIOCDELPRL: 898 case SIOCCHGPRL: 899 err = -EPERM; 900 if (!capable(CAP_NET_ADMIN)) 901 goto done; 902 err = -EINVAL; 903 if (dev == sitn->fb_tunnel_dev) 904 goto done; 905 err = -EFAULT; 906 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 907 goto done; 908 err = -ENOENT; 909 if (!(t = netdev_priv(dev))) 910 goto done; 911 912 switch (cmd) { 913 case SIOCDELPRL: 914 err = ipip6_tunnel_del_prl(t, &prl); 915 break; 916 case SIOCADDPRL: 917 case SIOCCHGPRL: 918 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 919 break; 920 } 921 netdev_state_change(dev); 922 break; 923 924 default: 925 err = -EINVAL; 926 } 927 928 done: 929 return err; 930 } 931 932 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 933 { 934 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 935 return -EINVAL; 936 dev->mtu = new_mtu; 937 return 0; 938 } 939 940 static const struct net_device_ops ipip6_netdev_ops = { 941 .ndo_uninit = ipip6_tunnel_uninit, 942 .ndo_start_xmit = ipip6_tunnel_xmit, 943 .ndo_do_ioctl = ipip6_tunnel_ioctl, 944 .ndo_change_mtu = ipip6_tunnel_change_mtu, 945 }; 946 947 static void ipip6_tunnel_setup(struct net_device *dev) 948 { 949 dev->netdev_ops = &ipip6_netdev_ops; 950 dev->destructor = free_netdev; 951 952 dev->type = ARPHRD_SIT; 953 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 954 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 955 dev->flags = IFF_NOARP; 956 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 957 dev->iflink = 0; 958 dev->addr_len = 4; 959 dev->features |= NETIF_F_NETNS_LOCAL; 960 } 961 962 static void ipip6_tunnel_init(struct net_device *dev) 963 { 964 struct ip_tunnel *tunnel = netdev_priv(dev); 965 966 tunnel->dev = dev; 967 strcpy(tunnel->parms.name, dev->name); 968 969 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 970 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 971 972 ipip6_tunnel_bind_dev(dev); 973 } 974 975 static void ipip6_fb_tunnel_init(struct net_device *dev) 976 { 977 struct ip_tunnel *tunnel = netdev_priv(dev); 978 struct iphdr *iph = &tunnel->parms.iph; 979 struct net *net = dev_net(dev); 980 struct sit_net *sitn = net_generic(net, sit_net_id); 981 982 tunnel->dev = dev; 983 strcpy(tunnel->parms.name, dev->name); 984 985 iph->version = 4; 986 iph->protocol = IPPROTO_IPV6; 987 iph->ihl = 5; 988 iph->ttl = 64; 989 990 dev_hold(dev); 991 sitn->tunnels_wc[0] = tunnel; 992 } 993 994 static struct xfrm_tunnel sit_handler = { 995 .handler = ipip6_rcv, 996 .err_handler = ipip6_err, 997 .priority = 1, 998 }; 999 1000 static void sit_destroy_tunnels(struct sit_net *sitn) 1001 { 1002 int prio; 1003 1004 for (prio = 1; prio < 4; prio++) { 1005 int h; 1006 for (h = 0; h < HASH_SIZE; h++) { 1007 struct ip_tunnel *t; 1008 while ((t = sitn->tunnels[prio][h]) != NULL) 1009 unregister_netdevice(t->dev); 1010 } 1011 } 1012 } 1013 1014 static int sit_init_net(struct net *net) 1015 { 1016 int err; 1017 struct sit_net *sitn; 1018 1019 err = -ENOMEM; 1020 sitn = kzalloc(sizeof(struct sit_net), GFP_KERNEL); 1021 if (sitn == NULL) 1022 goto err_alloc; 1023 1024 err = net_assign_generic(net, sit_net_id, sitn); 1025 if (err < 0) 1026 goto err_assign; 1027 1028 sitn->tunnels[0] = sitn->tunnels_wc; 1029 sitn->tunnels[1] = sitn->tunnels_l; 1030 sitn->tunnels[2] = sitn->tunnels_r; 1031 sitn->tunnels[3] = sitn->tunnels_r_l; 1032 1033 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1034 ipip6_tunnel_setup); 1035 if (!sitn->fb_tunnel_dev) { 1036 err = -ENOMEM; 1037 goto err_alloc_dev; 1038 } 1039 dev_net_set(sitn->fb_tunnel_dev, net); 1040 1041 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1042 1043 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1044 goto err_reg_dev; 1045 1046 return 0; 1047 1048 err_reg_dev: 1049 dev_put(sitn->fb_tunnel_dev); 1050 free_netdev(sitn->fb_tunnel_dev); 1051 err_alloc_dev: 1052 /* nothing */ 1053 err_assign: 1054 kfree(sitn); 1055 err_alloc: 1056 return err; 1057 } 1058 1059 static void sit_exit_net(struct net *net) 1060 { 1061 struct sit_net *sitn; 1062 1063 sitn = net_generic(net, sit_net_id); 1064 rtnl_lock(); 1065 sit_destroy_tunnels(sitn); 1066 unregister_netdevice(sitn->fb_tunnel_dev); 1067 rtnl_unlock(); 1068 kfree(sitn); 1069 } 1070 1071 static struct pernet_operations sit_net_ops = { 1072 .init = sit_init_net, 1073 .exit = sit_exit_net, 1074 }; 1075 1076 static void __exit sit_cleanup(void) 1077 { 1078 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1079 1080 unregister_pernet_gen_device(sit_net_id, &sit_net_ops); 1081 } 1082 1083 static int __init sit_init(void) 1084 { 1085 int err; 1086 1087 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1088 1089 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) { 1090 printk(KERN_INFO "sit init: Can't add protocol\n"); 1091 return -EAGAIN; 1092 } 1093 1094 err = register_pernet_gen_device(&sit_net_id, &sit_net_ops); 1095 if (err < 0) 1096 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1097 1098 return err; 1099 } 1100 1101 module_init(sit_init); 1102 module_exit(sit_cleanup); 1103 MODULE_LICENSE("GPL"); 1104 MODULE_ALIAS("sit0"); 1105