1 /* 2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT) 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 * 14 * Changes: 15 * Roger Venning <r.venning@telstra.com>: 6to4 support 16 * Nate Thompson <nate@thebog.net>: 6to4 support 17 * Fred Templin <fred.l.templin@boeing.com>: isatap support 18 */ 19 20 #include <linux/module.h> 21 #include <linux/capability.h> 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/socket.h> 25 #include <linux/sockios.h> 26 #include <linux/net.h> 27 #include <linux/in6.h> 28 #include <linux/netdevice.h> 29 #include <linux/if_arp.h> 30 #include <linux/icmp.h> 31 #include <linux/slab.h> 32 #include <asm/uaccess.h> 33 #include <linux/init.h> 34 #include <linux/netfilter_ipv4.h> 35 #include <linux/if_ether.h> 36 37 #include <net/sock.h> 38 #include <net/snmp.h> 39 40 #include <net/ipv6.h> 41 #include <net/protocol.h> 42 #include <net/transp_v6.h> 43 #include <net/ip6_fib.h> 44 #include <net/ip6_route.h> 45 #include <net/ndisc.h> 46 #include <net/addrconf.h> 47 #include <net/ip.h> 48 #include <net/udp.h> 49 #include <net/icmp.h> 50 #include <net/ipip.h> 51 #include <net/inet_ecn.h> 52 #include <net/xfrm.h> 53 #include <net/dsfield.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 57 /* 58 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 59 60 For comments look at net/ipv4/ip_gre.c --ANK 61 */ 62 63 #define HASH_SIZE 16 64 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 65 66 static int ipip6_tunnel_init(struct net_device *dev); 67 static void ipip6_tunnel_setup(struct net_device *dev); 68 static void ipip6_dev_free(struct net_device *dev); 69 70 static int sit_net_id __read_mostly; 71 struct sit_net { 72 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE]; 73 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE]; 74 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE]; 75 struct ip_tunnel __rcu *tunnels_wc[1]; 76 struct ip_tunnel __rcu **tunnels[4]; 77 78 struct net_device *fb_tunnel_dev; 79 }; 80 81 /* 82 * Locking : hash tables are protected by RCU and RTNL 83 */ 84 85 #define for_each_ip_tunnel_rcu(start) \ 86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 87 88 /* often modified stats are per cpu, other are shared (netdev->stats) */ 89 struct pcpu_tstats { 90 unsigned long rx_packets; 91 unsigned long rx_bytes; 92 unsigned long tx_packets; 93 unsigned long tx_bytes; 94 }; 95 96 static struct net_device_stats *ipip6_get_stats(struct net_device *dev) 97 { 98 struct pcpu_tstats sum = { 0 }; 99 int i; 100 101 for_each_possible_cpu(i) { 102 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 103 104 sum.rx_packets += tstats->rx_packets; 105 sum.rx_bytes += tstats->rx_bytes; 106 sum.tx_packets += tstats->tx_packets; 107 sum.tx_bytes += tstats->tx_bytes; 108 } 109 dev->stats.rx_packets = sum.rx_packets; 110 dev->stats.rx_bytes = sum.rx_bytes; 111 dev->stats.tx_packets = sum.tx_packets; 112 dev->stats.tx_bytes = sum.tx_bytes; 113 return &dev->stats; 114 } 115 /* 116 * Must be invoked with rcu_read_lock 117 */ 118 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, 119 struct net_device *dev, __be32 remote, __be32 local) 120 { 121 unsigned int h0 = HASH(remote); 122 unsigned int h1 = HASH(local); 123 struct ip_tunnel *t; 124 struct sit_net *sitn = net_generic(net, sit_net_id); 125 126 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) { 127 if (local == t->parms.iph.saddr && 128 remote == t->parms.iph.daddr && 129 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 130 (t->dev->flags & IFF_UP)) 131 return t; 132 } 133 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) { 134 if (remote == t->parms.iph.daddr && 135 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 136 (t->dev->flags & IFF_UP)) 137 return t; 138 } 139 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) { 140 if (local == t->parms.iph.saddr && 141 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 142 (t->dev->flags & IFF_UP)) 143 return t; 144 } 145 t = rcu_dereference(sitn->tunnels_wc[0]); 146 if ((t != NULL) && (t->dev->flags & IFF_UP)) 147 return t; 148 return NULL; 149 } 150 151 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn, 152 struct ip_tunnel_parm *parms) 153 { 154 __be32 remote = parms->iph.daddr; 155 __be32 local = parms->iph.saddr; 156 unsigned int h = 0; 157 int prio = 0; 158 159 if (remote) { 160 prio |= 2; 161 h ^= HASH(remote); 162 } 163 if (local) { 164 prio |= 1; 165 h ^= HASH(local); 166 } 167 return &sitn->tunnels[prio][h]; 168 } 169 170 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn, 171 struct ip_tunnel *t) 172 { 173 return __ipip6_bucket(sitn, &t->parms); 174 } 175 176 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 177 { 178 struct ip_tunnel __rcu **tp; 179 struct ip_tunnel *iter; 180 181 for (tp = ipip6_bucket(sitn, t); 182 (iter = rtnl_dereference(*tp)) != NULL; 183 tp = &iter->next) { 184 if (t == iter) { 185 rcu_assign_pointer(*tp, t->next); 186 break; 187 } 188 } 189 } 190 191 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 192 { 193 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t); 194 195 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 196 rcu_assign_pointer(*tp, t); 197 } 198 199 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 200 { 201 #ifdef CONFIG_IPV6_SIT_6RD 202 struct ip_tunnel *t = netdev_priv(dev); 203 204 if (t->dev == sitn->fb_tunnel_dev) { 205 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 206 t->ip6rd.relay_prefix = 0; 207 t->ip6rd.prefixlen = 16; 208 t->ip6rd.relay_prefixlen = 0; 209 } else { 210 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 211 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 212 } 213 #endif 214 } 215 216 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, 217 struct ip_tunnel_parm *parms, int create) 218 { 219 __be32 remote = parms->iph.daddr; 220 __be32 local = parms->iph.saddr; 221 struct ip_tunnel *t, *nt; 222 struct ip_tunnel __rcu **tp; 223 struct net_device *dev; 224 char name[IFNAMSIZ]; 225 struct sit_net *sitn = net_generic(net, sit_net_id); 226 227 for (tp = __ipip6_bucket(sitn, parms); 228 (t = rtnl_dereference(*tp)) != NULL; 229 tp = &t->next) { 230 if (local == t->parms.iph.saddr && 231 remote == t->parms.iph.daddr && 232 parms->link == t->parms.link) { 233 if (create) 234 return NULL; 235 else 236 return t; 237 } 238 } 239 if (!create) 240 goto failed; 241 242 if (parms->name[0]) 243 strlcpy(name, parms->name, IFNAMSIZ); 244 else 245 strcpy(name, "sit%d"); 246 247 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 248 if (dev == NULL) 249 return NULL; 250 251 dev_net_set(dev, net); 252 253 if (strchr(name, '%')) { 254 if (dev_alloc_name(dev, name) < 0) 255 goto failed_free; 256 } 257 258 nt = netdev_priv(dev); 259 260 nt->parms = *parms; 261 if (ipip6_tunnel_init(dev) < 0) 262 goto failed_free; 263 ipip6_tunnel_clone_6rd(dev, sitn); 264 265 if (parms->i_flags & SIT_ISATAP) 266 dev->priv_flags |= IFF_ISATAP; 267 268 if (register_netdevice(dev) < 0) 269 goto failed_free; 270 271 dev_hold(dev); 272 273 ipip6_tunnel_link(sitn, nt); 274 return nt; 275 276 failed_free: 277 ipip6_dev_free(dev); 278 failed: 279 return NULL; 280 } 281 282 #define for_each_prl_rcu(start) \ 283 for (prl = rcu_dereference(start); \ 284 prl; \ 285 prl = rcu_dereference(prl->next)) 286 287 static struct ip_tunnel_prl_entry * 288 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 289 { 290 struct ip_tunnel_prl_entry *prl; 291 292 for_each_prl_rcu(t->prl) 293 if (prl->addr == addr) 294 break; 295 return prl; 296 297 } 298 299 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 300 struct ip_tunnel_prl __user *a) 301 { 302 struct ip_tunnel_prl kprl, *kp; 303 struct ip_tunnel_prl_entry *prl; 304 unsigned int cmax, c = 0, ca, len; 305 int ret = 0; 306 307 if (copy_from_user(&kprl, a, sizeof(kprl))) 308 return -EFAULT; 309 cmax = kprl.datalen / sizeof(kprl); 310 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 311 cmax = 1; 312 313 /* For simple GET or for root users, 314 * we try harder to allocate. 315 */ 316 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 317 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 318 NULL; 319 320 rcu_read_lock(); 321 322 ca = t->prl_count < cmax ? t->prl_count : cmax; 323 324 if (!kp) { 325 /* We don't try hard to allocate much memory for 326 * non-root users. 327 * For root users, retry allocating enough memory for 328 * the answer. 329 */ 330 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 331 if (!kp) { 332 ret = -ENOMEM; 333 goto out; 334 } 335 } 336 337 c = 0; 338 for_each_prl_rcu(t->prl) { 339 if (c >= cmax) 340 break; 341 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 342 continue; 343 kp[c].addr = prl->addr; 344 kp[c].flags = prl->flags; 345 c++; 346 if (kprl.addr != htonl(INADDR_ANY)) 347 break; 348 } 349 out: 350 rcu_read_unlock(); 351 352 len = sizeof(*kp) * c; 353 ret = 0; 354 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 355 ret = -EFAULT; 356 357 kfree(kp); 358 359 return ret; 360 } 361 362 static int 363 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 364 { 365 struct ip_tunnel_prl_entry *p; 366 int err = 0; 367 368 if (a->addr == htonl(INADDR_ANY)) 369 return -EINVAL; 370 371 ASSERT_RTNL(); 372 373 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) { 374 if (p->addr == a->addr) { 375 if (chg) { 376 p->flags = a->flags; 377 goto out; 378 } 379 err = -EEXIST; 380 goto out; 381 } 382 } 383 384 if (chg) { 385 err = -ENXIO; 386 goto out; 387 } 388 389 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 390 if (!p) { 391 err = -ENOBUFS; 392 goto out; 393 } 394 395 p->next = t->prl; 396 p->addr = a->addr; 397 p->flags = a->flags; 398 t->prl_count++; 399 rcu_assign_pointer(t->prl, p); 400 out: 401 return err; 402 } 403 404 static void prl_entry_destroy_rcu(struct rcu_head *head) 405 { 406 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head)); 407 } 408 409 static void prl_list_destroy_rcu(struct rcu_head *head) 410 { 411 struct ip_tunnel_prl_entry *p, *n; 412 413 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 414 do { 415 n = rcu_dereference_protected(p->next, 1); 416 kfree(p); 417 p = n; 418 } while (p); 419 } 420 421 static int 422 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 423 { 424 struct ip_tunnel_prl_entry *x; 425 struct ip_tunnel_prl_entry __rcu **p; 426 int err = 0; 427 428 ASSERT_RTNL(); 429 430 if (a && a->addr != htonl(INADDR_ANY)) { 431 for (p = &t->prl; 432 (x = rtnl_dereference(*p)) != NULL; 433 p = &x->next) { 434 if (x->addr == a->addr) { 435 *p = x->next; 436 call_rcu(&x->rcu_head, prl_entry_destroy_rcu); 437 t->prl_count--; 438 goto out; 439 } 440 } 441 err = -ENXIO; 442 } else { 443 x = rtnl_dereference(t->prl); 444 if (x) { 445 t->prl_count = 0; 446 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 447 t->prl = NULL; 448 } 449 } 450 out: 451 return err; 452 } 453 454 static int 455 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 456 { 457 struct ip_tunnel_prl_entry *p; 458 int ok = 1; 459 460 rcu_read_lock(); 461 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 462 if (p) { 463 if (p->flags & PRL_DEFAULT) 464 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 465 else 466 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 467 } else { 468 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 469 if (ipv6_addr_is_isatap(addr6) && 470 (addr6->s6_addr32[3] == iph->saddr) && 471 ipv6_chk_prefix(addr6, t->dev)) 472 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 473 else 474 ok = 0; 475 } 476 rcu_read_unlock(); 477 return ok; 478 } 479 480 static void ipip6_tunnel_uninit(struct net_device *dev) 481 { 482 struct net *net = dev_net(dev); 483 struct sit_net *sitn = net_generic(net, sit_net_id); 484 485 if (dev == sitn->fb_tunnel_dev) { 486 rcu_assign_pointer(sitn->tunnels_wc[0], NULL); 487 } else { 488 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 489 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 490 } 491 dev_put(dev); 492 } 493 494 495 static int ipip6_err(struct sk_buff *skb, u32 info) 496 { 497 498 /* All the routers (except for Linux) return only 499 8 bytes of packet payload. It means, that precise relaying of 500 ICMP in the real Internet is absolutely infeasible. 501 */ 502 struct iphdr *iph = (struct iphdr*)skb->data; 503 const int type = icmp_hdr(skb)->type; 504 const int code = icmp_hdr(skb)->code; 505 struct ip_tunnel *t; 506 int err; 507 508 switch (type) { 509 default: 510 case ICMP_PARAMETERPROB: 511 return 0; 512 513 case ICMP_DEST_UNREACH: 514 switch (code) { 515 case ICMP_SR_FAILED: 516 case ICMP_PORT_UNREACH: 517 /* Impossible event. */ 518 return 0; 519 case ICMP_FRAG_NEEDED: 520 /* Soft state for pmtu is maintained by IP core. */ 521 return 0; 522 default: 523 /* All others are translated to HOST_UNREACH. 524 rfc2003 contains "deep thoughts" about NET_UNREACH, 525 I believe they are just ether pollution. --ANK 526 */ 527 break; 528 } 529 break; 530 case ICMP_TIME_EXCEEDED: 531 if (code != ICMP_EXC_TTL) 532 return 0; 533 break; 534 } 535 536 err = -ENOENT; 537 538 rcu_read_lock(); 539 t = ipip6_tunnel_lookup(dev_net(skb->dev), 540 skb->dev, 541 iph->daddr, 542 iph->saddr); 543 if (t == NULL || t->parms.iph.daddr == 0) 544 goto out; 545 546 err = 0; 547 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 548 goto out; 549 550 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 551 t->err_count++; 552 else 553 t->err_count = 1; 554 t->err_time = jiffies; 555 out: 556 rcu_read_unlock(); 557 return err; 558 } 559 560 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 561 { 562 if (INET_ECN_is_ce(iph->tos)) 563 IP6_ECN_set_ce(ipv6_hdr(skb)); 564 } 565 566 static int ipip6_rcv(struct sk_buff *skb) 567 { 568 struct iphdr *iph; 569 struct ip_tunnel *tunnel; 570 571 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 572 goto out; 573 574 iph = ip_hdr(skb); 575 576 rcu_read_lock(); 577 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 578 iph->saddr, iph->daddr); 579 if (tunnel != NULL) { 580 struct pcpu_tstats *tstats; 581 582 secpath_reset(skb); 583 skb->mac_header = skb->network_header; 584 skb_reset_network_header(skb); 585 IPCB(skb)->flags = 0; 586 skb->protocol = htons(ETH_P_IPV6); 587 skb->pkt_type = PACKET_HOST; 588 589 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 590 !isatap_chksrc(skb, iph, tunnel)) { 591 tunnel->dev->stats.rx_errors++; 592 rcu_read_unlock(); 593 kfree_skb(skb); 594 return 0; 595 } 596 597 tstats = this_cpu_ptr(tunnel->dev->tstats); 598 tstats->rx_packets++; 599 tstats->rx_bytes += skb->len; 600 601 __skb_tunnel_rx(skb, tunnel->dev); 602 603 ipip6_ecn_decapsulate(iph, skb); 604 605 netif_rx(skb); 606 607 rcu_read_unlock(); 608 return 0; 609 } 610 611 /* no tunnel matched, let upstream know, ipsec may handle it */ 612 rcu_read_unlock(); 613 return 1; 614 out: 615 kfree_skb(skb); 616 return 0; 617 } 618 619 /* 620 * Returns the embedded IPv4 address if the IPv6 address 621 * comes from 6rd / 6to4 (RFC 3056) addr space. 622 */ 623 static inline 624 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel) 625 { 626 __be32 dst = 0; 627 628 #ifdef CONFIG_IPV6_SIT_6RD 629 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 630 tunnel->ip6rd.prefixlen)) { 631 unsigned int pbw0, pbi0; 632 int pbi1; 633 u32 d; 634 635 pbw0 = tunnel->ip6rd.prefixlen >> 5; 636 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 637 638 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 639 tunnel->ip6rd.relay_prefixlen; 640 641 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 642 if (pbi1 > 0) 643 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 644 (32 - pbi1); 645 646 dst = tunnel->ip6rd.relay_prefix | htonl(d); 647 } 648 #else 649 if (v6dst->s6_addr16[0] == htons(0x2002)) { 650 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 651 memcpy(&dst, &v6dst->s6_addr16[1], 4); 652 } 653 #endif 654 return dst; 655 } 656 657 /* 658 * This function assumes it is being called from dev_queue_xmit() 659 * and that skb is filled properly by that function. 660 */ 661 662 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 663 struct net_device *dev) 664 { 665 struct ip_tunnel *tunnel = netdev_priv(dev); 666 struct pcpu_tstats *tstats; 667 struct iphdr *tiph = &tunnel->parms.iph; 668 struct ipv6hdr *iph6 = ipv6_hdr(skb); 669 u8 tos = tunnel->parms.iph.tos; 670 __be16 df = tiph->frag_off; 671 struct rtable *rt; /* Route to the other host */ 672 struct net_device *tdev; /* Device to other host */ 673 struct iphdr *iph; /* Our new IP header */ 674 unsigned int max_headroom; /* The extra header space needed */ 675 __be32 dst = tiph->daddr; 676 int mtu; 677 struct in6_addr *addr6; 678 int addr_type; 679 680 if (skb->protocol != htons(ETH_P_IPV6)) 681 goto tx_error; 682 683 /* ISATAP (RFC4214) - must come before 6to4 */ 684 if (dev->priv_flags & IFF_ISATAP) { 685 struct neighbour *neigh = NULL; 686 687 if (skb_dst(skb)) 688 neigh = skb_dst(skb)->neighbour; 689 690 if (neigh == NULL) { 691 if (net_ratelimit()) 692 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 693 goto tx_error; 694 } 695 696 addr6 = (struct in6_addr*)&neigh->primary_key; 697 addr_type = ipv6_addr_type(addr6); 698 699 if ((addr_type & IPV6_ADDR_UNICAST) && 700 ipv6_addr_is_isatap(addr6)) 701 dst = addr6->s6_addr32[3]; 702 else 703 goto tx_error; 704 } 705 706 if (!dst) 707 dst = try_6rd(&iph6->daddr, tunnel); 708 709 if (!dst) { 710 struct neighbour *neigh = NULL; 711 712 if (skb_dst(skb)) 713 neigh = skb_dst(skb)->neighbour; 714 715 if (neigh == NULL) { 716 if (net_ratelimit()) 717 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 718 goto tx_error; 719 } 720 721 addr6 = (struct in6_addr*)&neigh->primary_key; 722 addr_type = ipv6_addr_type(addr6); 723 724 if (addr_type == IPV6_ADDR_ANY) { 725 addr6 = &ipv6_hdr(skb)->daddr; 726 addr_type = ipv6_addr_type(addr6); 727 } 728 729 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 730 goto tx_error_icmp; 731 732 dst = addr6->s6_addr32[3]; 733 } 734 735 rt = ip_route_output_ports(dev_net(dev), NULL, 736 dst, tiph->saddr, 737 0, 0, 738 IPPROTO_IPV6, RT_TOS(tos), 739 tunnel->parms.link); 740 if (IS_ERR(rt)) { 741 dev->stats.tx_carrier_errors++; 742 goto tx_error_icmp; 743 } 744 if (rt->rt_type != RTN_UNICAST) { 745 ip_rt_put(rt); 746 dev->stats.tx_carrier_errors++; 747 goto tx_error_icmp; 748 } 749 tdev = rt->dst.dev; 750 751 if (tdev == dev) { 752 ip_rt_put(rt); 753 dev->stats.collisions++; 754 goto tx_error; 755 } 756 757 if (df) { 758 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 759 760 if (mtu < 68) { 761 dev->stats.collisions++; 762 ip_rt_put(rt); 763 goto tx_error; 764 } 765 766 if (mtu < IPV6_MIN_MTU) { 767 mtu = IPV6_MIN_MTU; 768 df = 0; 769 } 770 771 if (tunnel->parms.iph.daddr && skb_dst(skb)) 772 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 773 774 if (skb->len > mtu) { 775 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 776 ip_rt_put(rt); 777 goto tx_error; 778 } 779 } 780 781 if (tunnel->err_count > 0) { 782 if (time_before(jiffies, 783 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 784 tunnel->err_count--; 785 dst_link_failure(skb); 786 } else 787 tunnel->err_count = 0; 788 } 789 790 /* 791 * Okay, now see if we can stuff it in the buffer as-is. 792 */ 793 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 794 795 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 796 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 797 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 798 if (!new_skb) { 799 ip_rt_put(rt); 800 dev->stats.tx_dropped++; 801 dev_kfree_skb(skb); 802 return NETDEV_TX_OK; 803 } 804 if (skb->sk) 805 skb_set_owner_w(new_skb, skb->sk); 806 dev_kfree_skb(skb); 807 skb = new_skb; 808 iph6 = ipv6_hdr(skb); 809 } 810 811 skb->transport_header = skb->network_header; 812 skb_push(skb, sizeof(struct iphdr)); 813 skb_reset_network_header(skb); 814 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 815 IPCB(skb)->flags = 0; 816 skb_dst_drop(skb); 817 skb_dst_set(skb, &rt->dst); 818 819 /* 820 * Push down and install the IPIP header. 821 */ 822 823 iph = ip_hdr(skb); 824 iph->version = 4; 825 iph->ihl = sizeof(struct iphdr)>>2; 826 iph->frag_off = df; 827 iph->protocol = IPPROTO_IPV6; 828 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 829 iph->daddr = rt->rt_dst; 830 iph->saddr = rt->rt_src; 831 832 if ((iph->ttl = tiph->ttl) == 0) 833 iph->ttl = iph6->hop_limit; 834 835 nf_reset(skb); 836 tstats = this_cpu_ptr(dev->tstats); 837 __IPTUNNEL_XMIT(tstats, &dev->stats); 838 return NETDEV_TX_OK; 839 840 tx_error_icmp: 841 dst_link_failure(skb); 842 tx_error: 843 dev->stats.tx_errors++; 844 dev_kfree_skb(skb); 845 return NETDEV_TX_OK; 846 } 847 848 static void ipip6_tunnel_bind_dev(struct net_device *dev) 849 { 850 struct net_device *tdev = NULL; 851 struct ip_tunnel *tunnel; 852 struct iphdr *iph; 853 854 tunnel = netdev_priv(dev); 855 iph = &tunnel->parms.iph; 856 857 if (iph->daddr) { 858 struct rtable *rt = ip_route_output_ports(dev_net(dev), NULL, 859 iph->daddr, iph->saddr, 860 0, 0, 861 IPPROTO_IPV6, 862 RT_TOS(iph->tos), 863 tunnel->parms.link); 864 865 if (!IS_ERR(rt)) { 866 tdev = rt->dst.dev; 867 ip_rt_put(rt); 868 } 869 dev->flags |= IFF_POINTOPOINT; 870 } 871 872 if (!tdev && tunnel->parms.link) 873 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 874 875 if (tdev) { 876 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 877 dev->mtu = tdev->mtu - sizeof(struct iphdr); 878 if (dev->mtu < IPV6_MIN_MTU) 879 dev->mtu = IPV6_MIN_MTU; 880 } 881 dev->iflink = tunnel->parms.link; 882 } 883 884 static int 885 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 886 { 887 int err = 0; 888 struct ip_tunnel_parm p; 889 struct ip_tunnel_prl prl; 890 struct ip_tunnel *t; 891 struct net *net = dev_net(dev); 892 struct sit_net *sitn = net_generic(net, sit_net_id); 893 #ifdef CONFIG_IPV6_SIT_6RD 894 struct ip_tunnel_6rd ip6rd; 895 #endif 896 897 switch (cmd) { 898 case SIOCGETTUNNEL: 899 #ifdef CONFIG_IPV6_SIT_6RD 900 case SIOCGET6RD: 901 #endif 902 t = NULL; 903 if (dev == sitn->fb_tunnel_dev) { 904 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 905 err = -EFAULT; 906 break; 907 } 908 t = ipip6_tunnel_locate(net, &p, 0); 909 } 910 if (t == NULL) 911 t = netdev_priv(dev); 912 913 err = -EFAULT; 914 if (cmd == SIOCGETTUNNEL) { 915 memcpy(&p, &t->parms, sizeof(p)); 916 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 917 sizeof(p))) 918 goto done; 919 #ifdef CONFIG_IPV6_SIT_6RD 920 } else { 921 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 922 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 923 ip6rd.prefixlen = t->ip6rd.prefixlen; 924 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 925 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 926 sizeof(ip6rd))) 927 goto done; 928 #endif 929 } 930 err = 0; 931 break; 932 933 case SIOCADDTUNNEL: 934 case SIOCCHGTUNNEL: 935 err = -EPERM; 936 if (!capable(CAP_NET_ADMIN)) 937 goto done; 938 939 err = -EFAULT; 940 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 941 goto done; 942 943 err = -EINVAL; 944 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 945 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 946 goto done; 947 if (p.iph.ttl) 948 p.iph.frag_off |= htons(IP_DF); 949 950 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 951 952 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 953 if (t != NULL) { 954 if (t->dev != dev) { 955 err = -EEXIST; 956 break; 957 } 958 } else { 959 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 960 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 961 err = -EINVAL; 962 break; 963 } 964 t = netdev_priv(dev); 965 ipip6_tunnel_unlink(sitn, t); 966 synchronize_net(); 967 t->parms.iph.saddr = p.iph.saddr; 968 t->parms.iph.daddr = p.iph.daddr; 969 memcpy(dev->dev_addr, &p.iph.saddr, 4); 970 memcpy(dev->broadcast, &p.iph.daddr, 4); 971 ipip6_tunnel_link(sitn, t); 972 netdev_state_change(dev); 973 } 974 } 975 976 if (t) { 977 err = 0; 978 if (cmd == SIOCCHGTUNNEL) { 979 t->parms.iph.ttl = p.iph.ttl; 980 t->parms.iph.tos = p.iph.tos; 981 if (t->parms.link != p.link) { 982 t->parms.link = p.link; 983 ipip6_tunnel_bind_dev(dev); 984 netdev_state_change(dev); 985 } 986 } 987 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 988 err = -EFAULT; 989 } else 990 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 991 break; 992 993 case SIOCDELTUNNEL: 994 err = -EPERM; 995 if (!capable(CAP_NET_ADMIN)) 996 goto done; 997 998 if (dev == sitn->fb_tunnel_dev) { 999 err = -EFAULT; 1000 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1001 goto done; 1002 err = -ENOENT; 1003 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 1004 goto done; 1005 err = -EPERM; 1006 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1007 goto done; 1008 dev = t->dev; 1009 } 1010 unregister_netdevice(dev); 1011 err = 0; 1012 break; 1013 1014 case SIOCGETPRL: 1015 err = -EINVAL; 1016 if (dev == sitn->fb_tunnel_dev) 1017 goto done; 1018 err = -ENOENT; 1019 if (!(t = netdev_priv(dev))) 1020 goto done; 1021 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1022 break; 1023 1024 case SIOCADDPRL: 1025 case SIOCDELPRL: 1026 case SIOCCHGPRL: 1027 err = -EPERM; 1028 if (!capable(CAP_NET_ADMIN)) 1029 goto done; 1030 err = -EINVAL; 1031 if (dev == sitn->fb_tunnel_dev) 1032 goto done; 1033 err = -EFAULT; 1034 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1035 goto done; 1036 err = -ENOENT; 1037 if (!(t = netdev_priv(dev))) 1038 goto done; 1039 1040 switch (cmd) { 1041 case SIOCDELPRL: 1042 err = ipip6_tunnel_del_prl(t, &prl); 1043 break; 1044 case SIOCADDPRL: 1045 case SIOCCHGPRL: 1046 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1047 break; 1048 } 1049 netdev_state_change(dev); 1050 break; 1051 1052 #ifdef CONFIG_IPV6_SIT_6RD 1053 case SIOCADD6RD: 1054 case SIOCCHG6RD: 1055 case SIOCDEL6RD: 1056 err = -EPERM; 1057 if (!capable(CAP_NET_ADMIN)) 1058 goto done; 1059 1060 err = -EFAULT; 1061 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1062 sizeof(ip6rd))) 1063 goto done; 1064 1065 t = netdev_priv(dev); 1066 1067 if (cmd != SIOCDEL6RD) { 1068 struct in6_addr prefix; 1069 __be32 relay_prefix; 1070 1071 err = -EINVAL; 1072 if (ip6rd.relay_prefixlen > 32 || 1073 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1074 goto done; 1075 1076 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1077 ip6rd.prefixlen); 1078 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1079 goto done; 1080 if (ip6rd.relay_prefixlen) 1081 relay_prefix = ip6rd.relay_prefix & 1082 htonl(0xffffffffUL << 1083 (32 - ip6rd.relay_prefixlen)); 1084 else 1085 relay_prefix = 0; 1086 if (relay_prefix != ip6rd.relay_prefix) 1087 goto done; 1088 1089 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1090 t->ip6rd.relay_prefix = relay_prefix; 1091 t->ip6rd.prefixlen = ip6rd.prefixlen; 1092 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1093 } else 1094 ipip6_tunnel_clone_6rd(dev, sitn); 1095 1096 err = 0; 1097 break; 1098 #endif 1099 1100 default: 1101 err = -EINVAL; 1102 } 1103 1104 done: 1105 return err; 1106 } 1107 1108 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1109 { 1110 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1111 return -EINVAL; 1112 dev->mtu = new_mtu; 1113 return 0; 1114 } 1115 1116 static const struct net_device_ops ipip6_netdev_ops = { 1117 .ndo_uninit = ipip6_tunnel_uninit, 1118 .ndo_start_xmit = ipip6_tunnel_xmit, 1119 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1120 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1121 .ndo_get_stats = ipip6_get_stats, 1122 }; 1123 1124 static void ipip6_dev_free(struct net_device *dev) 1125 { 1126 free_percpu(dev->tstats); 1127 free_netdev(dev); 1128 } 1129 1130 static void ipip6_tunnel_setup(struct net_device *dev) 1131 { 1132 dev->netdev_ops = &ipip6_netdev_ops; 1133 dev->destructor = ipip6_dev_free; 1134 1135 dev->type = ARPHRD_SIT; 1136 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1137 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1138 dev->flags = IFF_NOARP; 1139 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1140 dev->iflink = 0; 1141 dev->addr_len = 4; 1142 dev->features |= NETIF_F_NETNS_LOCAL; 1143 dev->features |= NETIF_F_LLTX; 1144 } 1145 1146 static int ipip6_tunnel_init(struct net_device *dev) 1147 { 1148 struct ip_tunnel *tunnel = netdev_priv(dev); 1149 1150 tunnel->dev = dev; 1151 strcpy(tunnel->parms.name, dev->name); 1152 1153 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1154 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1155 1156 ipip6_tunnel_bind_dev(dev); 1157 dev->tstats = alloc_percpu(struct pcpu_tstats); 1158 if (!dev->tstats) 1159 return -ENOMEM; 1160 1161 return 0; 1162 } 1163 1164 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1165 { 1166 struct ip_tunnel *tunnel = netdev_priv(dev); 1167 struct iphdr *iph = &tunnel->parms.iph; 1168 struct net *net = dev_net(dev); 1169 struct sit_net *sitn = net_generic(net, sit_net_id); 1170 1171 tunnel->dev = dev; 1172 strcpy(tunnel->parms.name, dev->name); 1173 1174 iph->version = 4; 1175 iph->protocol = IPPROTO_IPV6; 1176 iph->ihl = 5; 1177 iph->ttl = 64; 1178 1179 dev->tstats = alloc_percpu(struct pcpu_tstats); 1180 if (!dev->tstats) 1181 return -ENOMEM; 1182 dev_hold(dev); 1183 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1184 return 0; 1185 } 1186 1187 static struct xfrm_tunnel sit_handler __read_mostly = { 1188 .handler = ipip6_rcv, 1189 .err_handler = ipip6_err, 1190 .priority = 1, 1191 }; 1192 1193 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1194 { 1195 int prio; 1196 1197 for (prio = 1; prio < 4; prio++) { 1198 int h; 1199 for (h = 0; h < HASH_SIZE; h++) { 1200 struct ip_tunnel *t; 1201 1202 t = rtnl_dereference(sitn->tunnels[prio][h]); 1203 while (t != NULL) { 1204 unregister_netdevice_queue(t->dev, head); 1205 t = rtnl_dereference(t->next); 1206 } 1207 } 1208 } 1209 } 1210 1211 static int __net_init sit_init_net(struct net *net) 1212 { 1213 struct sit_net *sitn = net_generic(net, sit_net_id); 1214 int err; 1215 1216 sitn->tunnels[0] = sitn->tunnels_wc; 1217 sitn->tunnels[1] = sitn->tunnels_l; 1218 sitn->tunnels[2] = sitn->tunnels_r; 1219 sitn->tunnels[3] = sitn->tunnels_r_l; 1220 1221 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1222 ipip6_tunnel_setup); 1223 if (!sitn->fb_tunnel_dev) { 1224 err = -ENOMEM; 1225 goto err_alloc_dev; 1226 } 1227 dev_net_set(sitn->fb_tunnel_dev, net); 1228 1229 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1230 if (err) 1231 goto err_dev_free; 1232 1233 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1234 1235 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1236 goto err_reg_dev; 1237 1238 return 0; 1239 1240 err_reg_dev: 1241 dev_put(sitn->fb_tunnel_dev); 1242 err_dev_free: 1243 ipip6_dev_free(sitn->fb_tunnel_dev); 1244 err_alloc_dev: 1245 return err; 1246 } 1247 1248 static void __net_exit sit_exit_net(struct net *net) 1249 { 1250 struct sit_net *sitn = net_generic(net, sit_net_id); 1251 LIST_HEAD(list); 1252 1253 rtnl_lock(); 1254 sit_destroy_tunnels(sitn, &list); 1255 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1256 unregister_netdevice_many(&list); 1257 rtnl_unlock(); 1258 } 1259 1260 static struct pernet_operations sit_net_ops = { 1261 .init = sit_init_net, 1262 .exit = sit_exit_net, 1263 .id = &sit_net_id, 1264 .size = sizeof(struct sit_net), 1265 }; 1266 1267 static void __exit sit_cleanup(void) 1268 { 1269 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1270 1271 unregister_pernet_device(&sit_net_ops); 1272 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1273 } 1274 1275 static int __init sit_init(void) 1276 { 1277 int err; 1278 1279 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1280 1281 err = register_pernet_device(&sit_net_ops); 1282 if (err < 0) 1283 return err; 1284 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1285 if (err < 0) { 1286 unregister_pernet_device(&sit_net_ops); 1287 printk(KERN_INFO "sit init: Can't add protocol\n"); 1288 } 1289 return err; 1290 } 1291 1292 module_init(sit_init); 1293 module_exit(sit_cleanup); 1294 MODULE_LICENSE("GPL"); 1295 MODULE_ALIAS_NETDEV("sit0"); 1296