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 = p->next; 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, **p; 425 int err = 0; 426 427 ASSERT_RTNL(); 428 429 if (a && a->addr != htonl(INADDR_ANY)) { 430 for (p = &t->prl; *p; p = &(*p)->next) { 431 if ((*p)->addr == a->addr) { 432 x = *p; 433 *p = x->next; 434 call_rcu(&x->rcu_head, prl_entry_destroy_rcu); 435 t->prl_count--; 436 goto out; 437 } 438 } 439 err = -ENXIO; 440 } else { 441 if (t->prl) { 442 t->prl_count = 0; 443 x = t->prl; 444 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 445 t->prl = NULL; 446 } 447 } 448 out: 449 return err; 450 } 451 452 static int 453 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 454 { 455 struct ip_tunnel_prl_entry *p; 456 int ok = 1; 457 458 rcu_read_lock(); 459 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 460 if (p) { 461 if (p->flags & PRL_DEFAULT) 462 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 463 else 464 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 465 } else { 466 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 467 if (ipv6_addr_is_isatap(addr6) && 468 (addr6->s6_addr32[3] == iph->saddr) && 469 ipv6_chk_prefix(addr6, t->dev)) 470 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 471 else 472 ok = 0; 473 } 474 rcu_read_unlock(); 475 return ok; 476 } 477 478 static void ipip6_tunnel_uninit(struct net_device *dev) 479 { 480 struct net *net = dev_net(dev); 481 struct sit_net *sitn = net_generic(net, sit_net_id); 482 483 if (dev == sitn->fb_tunnel_dev) { 484 rcu_assign_pointer(sitn->tunnels_wc[0], NULL); 485 } else { 486 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 487 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 488 } 489 dev_put(dev); 490 } 491 492 493 static int ipip6_err(struct sk_buff *skb, u32 info) 494 { 495 496 /* All the routers (except for Linux) return only 497 8 bytes of packet payload. It means, that precise relaying of 498 ICMP in the real Internet is absolutely infeasible. 499 */ 500 struct iphdr *iph = (struct iphdr*)skb->data; 501 const int type = icmp_hdr(skb)->type; 502 const int code = icmp_hdr(skb)->code; 503 struct ip_tunnel *t; 504 int err; 505 506 switch (type) { 507 default: 508 case ICMP_PARAMETERPROB: 509 return 0; 510 511 case ICMP_DEST_UNREACH: 512 switch (code) { 513 case ICMP_SR_FAILED: 514 case ICMP_PORT_UNREACH: 515 /* Impossible event. */ 516 return 0; 517 case ICMP_FRAG_NEEDED: 518 /* Soft state for pmtu is maintained by IP core. */ 519 return 0; 520 default: 521 /* All others are translated to HOST_UNREACH. 522 rfc2003 contains "deep thoughts" about NET_UNREACH, 523 I believe they are just ether pollution. --ANK 524 */ 525 break; 526 } 527 break; 528 case ICMP_TIME_EXCEEDED: 529 if (code != ICMP_EXC_TTL) 530 return 0; 531 break; 532 } 533 534 err = -ENOENT; 535 536 rcu_read_lock(); 537 t = ipip6_tunnel_lookup(dev_net(skb->dev), 538 skb->dev, 539 iph->daddr, 540 iph->saddr); 541 if (t == NULL || t->parms.iph.daddr == 0) 542 goto out; 543 544 err = 0; 545 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 546 goto out; 547 548 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 549 t->err_count++; 550 else 551 t->err_count = 1; 552 t->err_time = jiffies; 553 out: 554 rcu_read_unlock(); 555 return err; 556 } 557 558 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 559 { 560 if (INET_ECN_is_ce(iph->tos)) 561 IP6_ECN_set_ce(ipv6_hdr(skb)); 562 } 563 564 static int ipip6_rcv(struct sk_buff *skb) 565 { 566 struct iphdr *iph; 567 struct ip_tunnel *tunnel; 568 569 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 570 goto out; 571 572 iph = ip_hdr(skb); 573 574 rcu_read_lock(); 575 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 576 iph->saddr, iph->daddr); 577 if (tunnel != NULL) { 578 struct pcpu_tstats *tstats; 579 580 secpath_reset(skb); 581 skb->mac_header = skb->network_header; 582 skb_reset_network_header(skb); 583 IPCB(skb)->flags = 0; 584 skb->protocol = htons(ETH_P_IPV6); 585 skb->pkt_type = PACKET_HOST; 586 587 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 588 !isatap_chksrc(skb, iph, tunnel)) { 589 tunnel->dev->stats.rx_errors++; 590 rcu_read_unlock(); 591 kfree_skb(skb); 592 return 0; 593 } 594 595 tstats = this_cpu_ptr(tunnel->dev->tstats); 596 tstats->rx_packets++; 597 tstats->rx_bytes += skb->len; 598 599 __skb_tunnel_rx(skb, tunnel->dev); 600 601 ipip6_ecn_decapsulate(iph, skb); 602 603 netif_rx(skb); 604 605 rcu_read_unlock(); 606 return 0; 607 } 608 609 /* no tunnel matched, let upstream know, ipsec may handle it */ 610 rcu_read_unlock(); 611 return 1; 612 out: 613 kfree_skb(skb); 614 return 0; 615 } 616 617 /* 618 * Returns the embedded IPv4 address if the IPv6 address 619 * comes from 6rd / 6to4 (RFC 3056) addr space. 620 */ 621 static inline 622 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel) 623 { 624 __be32 dst = 0; 625 626 #ifdef CONFIG_IPV6_SIT_6RD 627 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 628 tunnel->ip6rd.prefixlen)) { 629 unsigned int pbw0, pbi0; 630 int pbi1; 631 u32 d; 632 633 pbw0 = tunnel->ip6rd.prefixlen >> 5; 634 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 635 636 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 637 tunnel->ip6rd.relay_prefixlen; 638 639 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 640 if (pbi1 > 0) 641 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 642 (32 - pbi1); 643 644 dst = tunnel->ip6rd.relay_prefix | htonl(d); 645 } 646 #else 647 if (v6dst->s6_addr16[0] == htons(0x2002)) { 648 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 649 memcpy(&dst, &v6dst->s6_addr16[1], 4); 650 } 651 #endif 652 return dst; 653 } 654 655 /* 656 * This function assumes it is being called from dev_queue_xmit() 657 * and that skb is filled properly by that function. 658 */ 659 660 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 661 struct net_device *dev) 662 { 663 struct ip_tunnel *tunnel = netdev_priv(dev); 664 struct pcpu_tstats *tstats; 665 struct iphdr *tiph = &tunnel->parms.iph; 666 struct ipv6hdr *iph6 = ipv6_hdr(skb); 667 u8 tos = tunnel->parms.iph.tos; 668 __be16 df = tiph->frag_off; 669 struct rtable *rt; /* Route to the other host */ 670 struct net_device *tdev; /* Device to other host */ 671 struct iphdr *iph; /* Our new IP header */ 672 unsigned int max_headroom; /* The extra header space needed */ 673 __be32 dst = tiph->daddr; 674 int mtu; 675 struct in6_addr *addr6; 676 int addr_type; 677 678 if (skb->protocol != htons(ETH_P_IPV6)) 679 goto tx_error; 680 681 /* ISATAP (RFC4214) - must come before 6to4 */ 682 if (dev->priv_flags & IFF_ISATAP) { 683 struct neighbour *neigh = NULL; 684 685 if (skb_dst(skb)) 686 neigh = skb_dst(skb)->neighbour; 687 688 if (neigh == NULL) { 689 if (net_ratelimit()) 690 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 691 goto tx_error; 692 } 693 694 addr6 = (struct in6_addr*)&neigh->primary_key; 695 addr_type = ipv6_addr_type(addr6); 696 697 if ((addr_type & IPV6_ADDR_UNICAST) && 698 ipv6_addr_is_isatap(addr6)) 699 dst = addr6->s6_addr32[3]; 700 else 701 goto tx_error; 702 } 703 704 if (!dst) 705 dst = try_6rd(&iph6->daddr, tunnel); 706 707 if (!dst) { 708 struct neighbour *neigh = NULL; 709 710 if (skb_dst(skb)) 711 neigh = skb_dst(skb)->neighbour; 712 713 if (neigh == NULL) { 714 if (net_ratelimit()) 715 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 716 goto tx_error; 717 } 718 719 addr6 = (struct in6_addr*)&neigh->primary_key; 720 addr_type = ipv6_addr_type(addr6); 721 722 if (addr_type == IPV6_ADDR_ANY) { 723 addr6 = &ipv6_hdr(skb)->daddr; 724 addr_type = ipv6_addr_type(addr6); 725 } 726 727 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 728 goto tx_error_icmp; 729 730 dst = addr6->s6_addr32[3]; 731 } 732 733 { 734 struct flowi fl = { .fl4_dst = dst, 735 .fl4_src = tiph->saddr, 736 .fl4_tos = RT_TOS(tos), 737 .oif = tunnel->parms.link, 738 .proto = IPPROTO_IPV6 }; 739 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 740 dev->stats.tx_carrier_errors++; 741 goto tx_error_icmp; 742 } 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 flowi fl = { .fl4_dst = iph->daddr, 859 .fl4_src = iph->saddr, 860 .fl4_tos = RT_TOS(iph->tos), 861 .oif = tunnel->parms.link, 862 .proto = IPPROTO_IPV6 }; 863 struct rtable *rt; 864 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 865 tdev = rt->dst.dev; 866 ip_rt_put(rt); 867 } 868 dev->flags |= IFF_POINTOPOINT; 869 } 870 871 if (!tdev && tunnel->parms.link) 872 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 873 874 if (tdev) { 875 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 876 dev->mtu = tdev->mtu - sizeof(struct iphdr); 877 if (dev->mtu < IPV6_MIN_MTU) 878 dev->mtu = IPV6_MIN_MTU; 879 } 880 dev->iflink = tunnel->parms.link; 881 } 882 883 static int 884 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 885 { 886 int err = 0; 887 struct ip_tunnel_parm p; 888 struct ip_tunnel_prl prl; 889 struct ip_tunnel *t; 890 struct net *net = dev_net(dev); 891 struct sit_net *sitn = net_generic(net, sit_net_id); 892 #ifdef CONFIG_IPV6_SIT_6RD 893 struct ip_tunnel_6rd ip6rd; 894 #endif 895 896 switch (cmd) { 897 case SIOCGETTUNNEL: 898 #ifdef CONFIG_IPV6_SIT_6RD 899 case SIOCGET6RD: 900 #endif 901 t = NULL; 902 if (dev == sitn->fb_tunnel_dev) { 903 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 904 err = -EFAULT; 905 break; 906 } 907 t = ipip6_tunnel_locate(net, &p, 0); 908 } 909 if (t == NULL) 910 t = netdev_priv(dev); 911 912 err = -EFAULT; 913 if (cmd == SIOCGETTUNNEL) { 914 memcpy(&p, &t->parms, sizeof(p)); 915 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 916 sizeof(p))) 917 goto done; 918 #ifdef CONFIG_IPV6_SIT_6RD 919 } else { 920 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 921 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 922 ip6rd.prefixlen = t->ip6rd.prefixlen; 923 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 924 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 925 sizeof(ip6rd))) 926 goto done; 927 #endif 928 } 929 err = 0; 930 break; 931 932 case SIOCADDTUNNEL: 933 case SIOCCHGTUNNEL: 934 err = -EPERM; 935 if (!capable(CAP_NET_ADMIN)) 936 goto done; 937 938 err = -EFAULT; 939 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 940 goto done; 941 942 err = -EINVAL; 943 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 944 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 945 goto done; 946 if (p.iph.ttl) 947 p.iph.frag_off |= htons(IP_DF); 948 949 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 950 951 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 952 if (t != NULL) { 953 if (t->dev != dev) { 954 err = -EEXIST; 955 break; 956 } 957 } else { 958 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 959 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 960 err = -EINVAL; 961 break; 962 } 963 t = netdev_priv(dev); 964 ipip6_tunnel_unlink(sitn, t); 965 synchronize_net(); 966 t->parms.iph.saddr = p.iph.saddr; 967 t->parms.iph.daddr = p.iph.daddr; 968 memcpy(dev->dev_addr, &p.iph.saddr, 4); 969 memcpy(dev->broadcast, &p.iph.daddr, 4); 970 ipip6_tunnel_link(sitn, t); 971 netdev_state_change(dev); 972 } 973 } 974 975 if (t) { 976 err = 0; 977 if (cmd == SIOCCHGTUNNEL) { 978 t->parms.iph.ttl = p.iph.ttl; 979 t->parms.iph.tos = p.iph.tos; 980 if (t->parms.link != p.link) { 981 t->parms.link = p.link; 982 ipip6_tunnel_bind_dev(dev); 983 netdev_state_change(dev); 984 } 985 } 986 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 987 err = -EFAULT; 988 } else 989 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 990 break; 991 992 case SIOCDELTUNNEL: 993 err = -EPERM; 994 if (!capable(CAP_NET_ADMIN)) 995 goto done; 996 997 if (dev == sitn->fb_tunnel_dev) { 998 err = -EFAULT; 999 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1000 goto done; 1001 err = -ENOENT; 1002 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 1003 goto done; 1004 err = -EPERM; 1005 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1006 goto done; 1007 dev = t->dev; 1008 } 1009 unregister_netdevice(dev); 1010 err = 0; 1011 break; 1012 1013 case SIOCGETPRL: 1014 err = -EINVAL; 1015 if (dev == sitn->fb_tunnel_dev) 1016 goto done; 1017 err = -ENOENT; 1018 if (!(t = netdev_priv(dev))) 1019 goto done; 1020 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1021 break; 1022 1023 case SIOCADDPRL: 1024 case SIOCDELPRL: 1025 case SIOCCHGPRL: 1026 err = -EPERM; 1027 if (!capable(CAP_NET_ADMIN)) 1028 goto done; 1029 err = -EINVAL; 1030 if (dev == sitn->fb_tunnel_dev) 1031 goto done; 1032 err = -EFAULT; 1033 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1034 goto done; 1035 err = -ENOENT; 1036 if (!(t = netdev_priv(dev))) 1037 goto done; 1038 1039 switch (cmd) { 1040 case SIOCDELPRL: 1041 err = ipip6_tunnel_del_prl(t, &prl); 1042 break; 1043 case SIOCADDPRL: 1044 case SIOCCHGPRL: 1045 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1046 break; 1047 } 1048 netdev_state_change(dev); 1049 break; 1050 1051 #ifdef CONFIG_IPV6_SIT_6RD 1052 case SIOCADD6RD: 1053 case SIOCCHG6RD: 1054 case SIOCDEL6RD: 1055 err = -EPERM; 1056 if (!capable(CAP_NET_ADMIN)) 1057 goto done; 1058 1059 err = -EFAULT; 1060 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1061 sizeof(ip6rd))) 1062 goto done; 1063 1064 t = netdev_priv(dev); 1065 1066 if (cmd != SIOCDEL6RD) { 1067 struct in6_addr prefix; 1068 __be32 relay_prefix; 1069 1070 err = -EINVAL; 1071 if (ip6rd.relay_prefixlen > 32 || 1072 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1073 goto done; 1074 1075 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1076 ip6rd.prefixlen); 1077 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1078 goto done; 1079 if (ip6rd.relay_prefixlen) 1080 relay_prefix = ip6rd.relay_prefix & 1081 htonl(0xffffffffUL << 1082 (32 - ip6rd.relay_prefixlen)); 1083 else 1084 relay_prefix = 0; 1085 if (relay_prefix != ip6rd.relay_prefix) 1086 goto done; 1087 1088 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1089 t->ip6rd.relay_prefix = relay_prefix; 1090 t->ip6rd.prefixlen = ip6rd.prefixlen; 1091 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1092 } else 1093 ipip6_tunnel_clone_6rd(dev, sitn); 1094 1095 err = 0; 1096 break; 1097 #endif 1098 1099 default: 1100 err = -EINVAL; 1101 } 1102 1103 done: 1104 return err; 1105 } 1106 1107 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1108 { 1109 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1110 return -EINVAL; 1111 dev->mtu = new_mtu; 1112 return 0; 1113 } 1114 1115 static const struct net_device_ops ipip6_netdev_ops = { 1116 .ndo_uninit = ipip6_tunnel_uninit, 1117 .ndo_start_xmit = ipip6_tunnel_xmit, 1118 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1119 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1120 .ndo_get_stats = ipip6_get_stats, 1121 }; 1122 1123 static void ipip6_dev_free(struct net_device *dev) 1124 { 1125 free_percpu(dev->tstats); 1126 free_netdev(dev); 1127 } 1128 1129 static void ipip6_tunnel_setup(struct net_device *dev) 1130 { 1131 dev->netdev_ops = &ipip6_netdev_ops; 1132 dev->destructor = ipip6_dev_free; 1133 1134 dev->type = ARPHRD_SIT; 1135 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1136 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1137 dev->flags = IFF_NOARP; 1138 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1139 dev->iflink = 0; 1140 dev->addr_len = 4; 1141 dev->features |= NETIF_F_NETNS_LOCAL; 1142 dev->features |= NETIF_F_LLTX; 1143 } 1144 1145 static int ipip6_tunnel_init(struct net_device *dev) 1146 { 1147 struct ip_tunnel *tunnel = netdev_priv(dev); 1148 1149 tunnel->dev = dev; 1150 strcpy(tunnel->parms.name, dev->name); 1151 1152 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1153 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1154 1155 ipip6_tunnel_bind_dev(dev); 1156 dev->tstats = alloc_percpu(struct pcpu_tstats); 1157 if (!dev->tstats) 1158 return -ENOMEM; 1159 1160 return 0; 1161 } 1162 1163 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1164 { 1165 struct ip_tunnel *tunnel = netdev_priv(dev); 1166 struct iphdr *iph = &tunnel->parms.iph; 1167 struct net *net = dev_net(dev); 1168 struct sit_net *sitn = net_generic(net, sit_net_id); 1169 1170 tunnel->dev = dev; 1171 strcpy(tunnel->parms.name, dev->name); 1172 1173 iph->version = 4; 1174 iph->protocol = IPPROTO_IPV6; 1175 iph->ihl = 5; 1176 iph->ttl = 64; 1177 1178 dev->tstats = alloc_percpu(struct pcpu_tstats); 1179 if (!dev->tstats) 1180 return -ENOMEM; 1181 dev_hold(dev); 1182 sitn->tunnels_wc[0] = tunnel; 1183 return 0; 1184 } 1185 1186 static struct xfrm_tunnel sit_handler __read_mostly = { 1187 .handler = ipip6_rcv, 1188 .err_handler = ipip6_err, 1189 .priority = 1, 1190 }; 1191 1192 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1193 { 1194 int prio; 1195 1196 for (prio = 1; prio < 4; prio++) { 1197 int h; 1198 for (h = 0; h < HASH_SIZE; h++) { 1199 struct ip_tunnel *t = sitn->tunnels[prio][h]; 1200 1201 while (t != NULL) { 1202 unregister_netdevice_queue(t->dev, head); 1203 t = t->next; 1204 } 1205 } 1206 } 1207 } 1208 1209 static int __net_init sit_init_net(struct net *net) 1210 { 1211 struct sit_net *sitn = net_generic(net, sit_net_id); 1212 int err; 1213 1214 sitn->tunnels[0] = sitn->tunnels_wc; 1215 sitn->tunnels[1] = sitn->tunnels_l; 1216 sitn->tunnels[2] = sitn->tunnels_r; 1217 sitn->tunnels[3] = sitn->tunnels_r_l; 1218 1219 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1220 ipip6_tunnel_setup); 1221 if (!sitn->fb_tunnel_dev) { 1222 err = -ENOMEM; 1223 goto err_alloc_dev; 1224 } 1225 dev_net_set(sitn->fb_tunnel_dev, net); 1226 1227 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1228 if (err) 1229 goto err_dev_free; 1230 1231 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1232 1233 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1234 goto err_reg_dev; 1235 1236 return 0; 1237 1238 err_reg_dev: 1239 dev_put(sitn->fb_tunnel_dev); 1240 err_dev_free: 1241 ipip6_dev_free(sitn->fb_tunnel_dev); 1242 err_alloc_dev: 1243 return err; 1244 } 1245 1246 static void __net_exit sit_exit_net(struct net *net) 1247 { 1248 struct sit_net *sitn = net_generic(net, sit_net_id); 1249 LIST_HEAD(list); 1250 1251 rtnl_lock(); 1252 sit_destroy_tunnels(sitn, &list); 1253 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1254 unregister_netdevice_many(&list); 1255 rtnl_unlock(); 1256 } 1257 1258 static struct pernet_operations sit_net_ops = { 1259 .init = sit_init_net, 1260 .exit = sit_exit_net, 1261 .id = &sit_net_id, 1262 .size = sizeof(struct sit_net), 1263 }; 1264 1265 static void __exit sit_cleanup(void) 1266 { 1267 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1268 1269 unregister_pernet_device(&sit_net_ops); 1270 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1271 } 1272 1273 static int __init sit_init(void) 1274 { 1275 int err; 1276 1277 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1278 1279 err = register_pernet_device(&sit_net_ops); 1280 if (err < 0) 1281 return err; 1282 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1283 if (err < 0) { 1284 unregister_pernet_device(&sit_net_ops); 1285 printk(KERN_INFO "sit init: Can't add protocol\n"); 1286 } 1287 return err; 1288 } 1289 1290 module_init(sit_init); 1291 module_exit(sit_cleanup); 1292 MODULE_LICENSE("GPL"); 1293 MODULE_ALIAS_NETDEV("sit0"); 1294