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 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 __read_mostly; 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 /* 81 * Locking : hash tables are protected by RCU and a spinlock 82 */ 83 static DEFINE_SPINLOCK(ipip6_lock); 84 85 #define for_each_ip_tunnel_rcu(start) \ 86 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 87 88 /* 89 * Must be invoked with rcu_read_lock 90 */ 91 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, 92 struct net_device *dev, __be32 remote, __be32 local) 93 { 94 unsigned h0 = HASH(remote); 95 unsigned h1 = HASH(local); 96 struct ip_tunnel *t; 97 struct sit_net *sitn = net_generic(net, sit_net_id); 98 99 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) { 100 if (local == t->parms.iph.saddr && 101 remote == t->parms.iph.daddr && 102 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 103 (t->dev->flags & IFF_UP)) 104 return t; 105 } 106 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) { 107 if (remote == t->parms.iph.daddr && 108 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 109 (t->dev->flags & IFF_UP)) 110 return t; 111 } 112 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) { 113 if (local == t->parms.iph.saddr && 114 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 115 (t->dev->flags & IFF_UP)) 116 return t; 117 } 118 t = rcu_dereference(sitn->tunnels_wc[0]); 119 if ((t != NULL) && (t->dev->flags & IFF_UP)) 120 return t; 121 return NULL; 122 } 123 124 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn, 125 struct ip_tunnel_parm *parms) 126 { 127 __be32 remote = parms->iph.daddr; 128 __be32 local = parms->iph.saddr; 129 unsigned h = 0; 130 int prio = 0; 131 132 if (remote) { 133 prio |= 2; 134 h ^= HASH(remote); 135 } 136 if (local) { 137 prio |= 1; 138 h ^= HASH(local); 139 } 140 return &sitn->tunnels[prio][h]; 141 } 142 143 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn, 144 struct ip_tunnel *t) 145 { 146 return __ipip6_bucket(sitn, &t->parms); 147 } 148 149 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 150 { 151 struct ip_tunnel **tp; 152 153 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) { 154 if (t == *tp) { 155 spin_lock_bh(&ipip6_lock); 156 *tp = t->next; 157 spin_unlock_bh(&ipip6_lock); 158 break; 159 } 160 } 161 } 162 163 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 164 { 165 struct ip_tunnel **tp = ipip6_bucket(sitn, t); 166 167 spin_lock_bh(&ipip6_lock); 168 t->next = *tp; 169 rcu_assign_pointer(*tp, t); 170 spin_unlock_bh(&ipip6_lock); 171 } 172 173 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 174 { 175 #ifdef CONFIG_IPV6_SIT_6RD 176 struct ip_tunnel *t = netdev_priv(dev); 177 178 if (t->dev == sitn->fb_tunnel_dev) { 179 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 180 t->ip6rd.relay_prefix = 0; 181 t->ip6rd.prefixlen = 16; 182 t->ip6rd.relay_prefixlen = 0; 183 } else { 184 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 185 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 186 } 187 #endif 188 } 189 190 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net, 191 struct ip_tunnel_parm *parms, int create) 192 { 193 __be32 remote = parms->iph.daddr; 194 __be32 local = parms->iph.saddr; 195 struct ip_tunnel *t, **tp, *nt; 196 struct net_device *dev; 197 char name[IFNAMSIZ]; 198 struct sit_net *sitn = net_generic(net, sit_net_id); 199 200 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) { 201 if (local == t->parms.iph.saddr && 202 remote == t->parms.iph.daddr && 203 parms->link == t->parms.link) { 204 if (create) 205 return NULL; 206 else 207 return t; 208 } 209 } 210 if (!create) 211 goto failed; 212 213 if (parms->name[0]) 214 strlcpy(name, parms->name, IFNAMSIZ); 215 else 216 sprintf(name, "sit%%d"); 217 218 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 219 if (dev == NULL) 220 return NULL; 221 222 dev_net_set(dev, net); 223 224 if (strchr(name, '%')) { 225 if (dev_alloc_name(dev, name) < 0) 226 goto failed_free; 227 } 228 229 nt = netdev_priv(dev); 230 231 nt->parms = *parms; 232 ipip6_tunnel_init(dev); 233 ipip6_tunnel_clone_6rd(dev, sitn); 234 235 if (parms->i_flags & SIT_ISATAP) 236 dev->priv_flags |= IFF_ISATAP; 237 238 if (register_netdevice(dev) < 0) 239 goto failed_free; 240 241 dev_hold(dev); 242 243 ipip6_tunnel_link(sitn, nt); 244 return nt; 245 246 failed_free: 247 free_netdev(dev); 248 failed: 249 return NULL; 250 } 251 252 static DEFINE_SPINLOCK(ipip6_prl_lock); 253 254 #define for_each_prl_rcu(start) \ 255 for (prl = rcu_dereference(start); \ 256 prl; \ 257 prl = rcu_dereference(prl->next)) 258 259 static struct ip_tunnel_prl_entry * 260 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 261 { 262 struct ip_tunnel_prl_entry *prl; 263 264 for_each_prl_rcu(t->prl) 265 if (prl->addr == addr) 266 break; 267 return prl; 268 269 } 270 271 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 272 struct ip_tunnel_prl __user *a) 273 { 274 struct ip_tunnel_prl kprl, *kp; 275 struct ip_tunnel_prl_entry *prl; 276 unsigned int cmax, c = 0, ca, len; 277 int ret = 0; 278 279 if (copy_from_user(&kprl, a, sizeof(kprl))) 280 return -EFAULT; 281 cmax = kprl.datalen / sizeof(kprl); 282 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 283 cmax = 1; 284 285 /* For simple GET or for root users, 286 * we try harder to allocate. 287 */ 288 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 289 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 290 NULL; 291 292 rcu_read_lock(); 293 294 ca = t->prl_count < cmax ? t->prl_count : cmax; 295 296 if (!kp) { 297 /* We don't try hard to allocate much memory for 298 * non-root users. 299 * For root users, retry allocating enough memory for 300 * the answer. 301 */ 302 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 303 if (!kp) { 304 ret = -ENOMEM; 305 goto out; 306 } 307 } 308 309 c = 0; 310 for_each_prl_rcu(t->prl) { 311 if (c >= cmax) 312 break; 313 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 314 continue; 315 kp[c].addr = prl->addr; 316 kp[c].flags = prl->flags; 317 c++; 318 if (kprl.addr != htonl(INADDR_ANY)) 319 break; 320 } 321 out: 322 rcu_read_unlock(); 323 324 len = sizeof(*kp) * c; 325 ret = 0; 326 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 327 ret = -EFAULT; 328 329 kfree(kp); 330 331 return ret; 332 } 333 334 static int 335 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 336 { 337 struct ip_tunnel_prl_entry *p; 338 int err = 0; 339 340 if (a->addr == htonl(INADDR_ANY)) 341 return -EINVAL; 342 343 spin_lock(&ipip6_prl_lock); 344 345 for (p = t->prl; p; p = p->next) { 346 if (p->addr == a->addr) { 347 if (chg) { 348 p->flags = a->flags; 349 goto out; 350 } 351 err = -EEXIST; 352 goto out; 353 } 354 } 355 356 if (chg) { 357 err = -ENXIO; 358 goto out; 359 } 360 361 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 362 if (!p) { 363 err = -ENOBUFS; 364 goto out; 365 } 366 367 p->next = t->prl; 368 p->addr = a->addr; 369 p->flags = a->flags; 370 t->prl_count++; 371 rcu_assign_pointer(t->prl, p); 372 out: 373 spin_unlock(&ipip6_prl_lock); 374 return err; 375 } 376 377 static void prl_entry_destroy_rcu(struct rcu_head *head) 378 { 379 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head)); 380 } 381 382 static void prl_list_destroy_rcu(struct rcu_head *head) 383 { 384 struct ip_tunnel_prl_entry *p, *n; 385 386 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 387 do { 388 n = p->next; 389 kfree(p); 390 p = n; 391 } while (p); 392 } 393 394 static int 395 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 396 { 397 struct ip_tunnel_prl_entry *x, **p; 398 int err = 0; 399 400 spin_lock(&ipip6_prl_lock); 401 402 if (a && a->addr != htonl(INADDR_ANY)) { 403 for (p = &t->prl; *p; p = &(*p)->next) { 404 if ((*p)->addr == a->addr) { 405 x = *p; 406 *p = x->next; 407 call_rcu(&x->rcu_head, prl_entry_destroy_rcu); 408 t->prl_count--; 409 goto out; 410 } 411 } 412 err = -ENXIO; 413 } else { 414 if (t->prl) { 415 t->prl_count = 0; 416 x = t->prl; 417 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 418 t->prl = NULL; 419 } 420 } 421 out: 422 spin_unlock(&ipip6_prl_lock); 423 return err; 424 } 425 426 static int 427 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 428 { 429 struct ip_tunnel_prl_entry *p; 430 int ok = 1; 431 432 rcu_read_lock(); 433 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 434 if (p) { 435 if (p->flags & PRL_DEFAULT) 436 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 437 else 438 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 439 } else { 440 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 441 if (ipv6_addr_is_isatap(addr6) && 442 (addr6->s6_addr32[3] == iph->saddr) && 443 ipv6_chk_prefix(addr6, t->dev)) 444 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 445 else 446 ok = 0; 447 } 448 rcu_read_unlock(); 449 return ok; 450 } 451 452 static void ipip6_tunnel_uninit(struct net_device *dev) 453 { 454 struct net *net = dev_net(dev); 455 struct sit_net *sitn = net_generic(net, sit_net_id); 456 457 if (dev == sitn->fb_tunnel_dev) { 458 spin_lock_bh(&ipip6_lock); 459 sitn->tunnels_wc[0] = NULL; 460 spin_unlock_bh(&ipip6_lock); 461 dev_put(dev); 462 } else { 463 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 464 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 465 dev_put(dev); 466 } 467 } 468 469 470 static int ipip6_err(struct sk_buff *skb, u32 info) 471 { 472 473 /* All the routers (except for Linux) return only 474 8 bytes of packet payload. It means, that precise relaying of 475 ICMP in the real Internet is absolutely infeasible. 476 */ 477 struct iphdr *iph = (struct iphdr*)skb->data; 478 const int type = icmp_hdr(skb)->type; 479 const int code = icmp_hdr(skb)->code; 480 struct ip_tunnel *t; 481 int err; 482 483 switch (type) { 484 default: 485 case ICMP_PARAMETERPROB: 486 return 0; 487 488 case ICMP_DEST_UNREACH: 489 switch (code) { 490 case ICMP_SR_FAILED: 491 case ICMP_PORT_UNREACH: 492 /* Impossible event. */ 493 return 0; 494 case ICMP_FRAG_NEEDED: 495 /* Soft state for pmtu is maintained by IP core. */ 496 return 0; 497 default: 498 /* All others are translated to HOST_UNREACH. 499 rfc2003 contains "deep thoughts" about NET_UNREACH, 500 I believe they are just ether pollution. --ANK 501 */ 502 break; 503 } 504 break; 505 case ICMP_TIME_EXCEEDED: 506 if (code != ICMP_EXC_TTL) 507 return 0; 508 break; 509 } 510 511 err = -ENOENT; 512 513 rcu_read_lock(); 514 t = ipip6_tunnel_lookup(dev_net(skb->dev), 515 skb->dev, 516 iph->daddr, 517 iph->saddr); 518 if (t == NULL || t->parms.iph.daddr == 0) 519 goto out; 520 521 err = 0; 522 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 523 goto out; 524 525 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 526 t->err_count++; 527 else 528 t->err_count = 1; 529 t->err_time = jiffies; 530 out: 531 rcu_read_unlock(); 532 return err; 533 } 534 535 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 536 { 537 if (INET_ECN_is_ce(iph->tos)) 538 IP6_ECN_set_ce(ipv6_hdr(skb)); 539 } 540 541 static int ipip6_rcv(struct sk_buff *skb) 542 { 543 struct iphdr *iph; 544 struct ip_tunnel *tunnel; 545 546 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 547 goto out; 548 549 iph = ip_hdr(skb); 550 551 rcu_read_lock(); 552 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 553 iph->saddr, iph->daddr); 554 if (tunnel != NULL) { 555 secpath_reset(skb); 556 skb->mac_header = skb->network_header; 557 skb_reset_network_header(skb); 558 IPCB(skb)->flags = 0; 559 skb->protocol = htons(ETH_P_IPV6); 560 skb->pkt_type = PACKET_HOST; 561 562 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 563 !isatap_chksrc(skb, iph, tunnel)) { 564 tunnel->dev->stats.rx_errors++; 565 rcu_read_unlock(); 566 kfree_skb(skb); 567 return 0; 568 } 569 tunnel->dev->stats.rx_packets++; 570 tunnel->dev->stats.rx_bytes += skb->len; 571 skb->dev = tunnel->dev; 572 skb_dst_drop(skb); 573 nf_reset(skb); 574 ipip6_ecn_decapsulate(iph, skb); 575 netif_rx(skb); 576 rcu_read_unlock(); 577 return 0; 578 } 579 580 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 581 rcu_read_unlock(); 582 out: 583 kfree_skb(skb); 584 return 0; 585 } 586 587 /* 588 * Returns the embedded IPv4 address if the IPv6 address 589 * comes from 6rd / 6to4 (RFC 3056) addr space. 590 */ 591 static inline 592 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel) 593 { 594 __be32 dst = 0; 595 596 #ifdef CONFIG_IPV6_SIT_6RD 597 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 598 tunnel->ip6rd.prefixlen)) { 599 unsigned pbw0, pbi0; 600 int pbi1; 601 u32 d; 602 603 pbw0 = tunnel->ip6rd.prefixlen >> 5; 604 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 605 606 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 607 tunnel->ip6rd.relay_prefixlen; 608 609 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 610 if (pbi1 > 0) 611 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 612 (32 - pbi1); 613 614 dst = tunnel->ip6rd.relay_prefix | htonl(d); 615 } 616 #else 617 if (v6dst->s6_addr16[0] == htons(0x2002)) { 618 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 619 memcpy(&dst, &v6dst->s6_addr16[1], 4); 620 } 621 #endif 622 return dst; 623 } 624 625 /* 626 * This function assumes it is being called from dev_queue_xmit() 627 * and that skb is filled properly by that function. 628 */ 629 630 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 631 struct net_device *dev) 632 { 633 struct ip_tunnel *tunnel = netdev_priv(dev); 634 struct net_device_stats *stats = &dev->stats; 635 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); 636 struct iphdr *tiph = &tunnel->parms.iph; 637 struct ipv6hdr *iph6 = ipv6_hdr(skb); 638 u8 tos = tunnel->parms.iph.tos; 639 __be16 df = tiph->frag_off; 640 struct rtable *rt; /* Route to the other host */ 641 struct net_device *tdev; /* Device to other host */ 642 struct iphdr *iph; /* Our new IP header */ 643 unsigned int max_headroom; /* The extra header space needed */ 644 __be32 dst = tiph->daddr; 645 int mtu; 646 struct in6_addr *addr6; 647 int addr_type; 648 649 if (skb->protocol != htons(ETH_P_IPV6)) 650 goto tx_error; 651 652 /* ISATAP (RFC4214) - must come before 6to4 */ 653 if (dev->priv_flags & IFF_ISATAP) { 654 struct neighbour *neigh = NULL; 655 656 if (skb_dst(skb)) 657 neigh = skb_dst(skb)->neighbour; 658 659 if (neigh == NULL) { 660 if (net_ratelimit()) 661 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 662 goto tx_error; 663 } 664 665 addr6 = (struct in6_addr*)&neigh->primary_key; 666 addr_type = ipv6_addr_type(addr6); 667 668 if ((addr_type & IPV6_ADDR_UNICAST) && 669 ipv6_addr_is_isatap(addr6)) 670 dst = addr6->s6_addr32[3]; 671 else 672 goto tx_error; 673 } 674 675 if (!dst) 676 dst = try_6rd(&iph6->daddr, tunnel); 677 678 if (!dst) { 679 struct neighbour *neigh = NULL; 680 681 if (skb_dst(skb)) 682 neigh = skb_dst(skb)->neighbour; 683 684 if (neigh == NULL) { 685 if (net_ratelimit()) 686 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 687 goto tx_error; 688 } 689 690 addr6 = (struct in6_addr*)&neigh->primary_key; 691 addr_type = ipv6_addr_type(addr6); 692 693 if (addr_type == IPV6_ADDR_ANY) { 694 addr6 = &ipv6_hdr(skb)->daddr; 695 addr_type = ipv6_addr_type(addr6); 696 } 697 698 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 699 goto tx_error_icmp; 700 701 dst = addr6->s6_addr32[3]; 702 } 703 704 { 705 struct flowi fl = { .nl_u = { .ip4_u = 706 { .daddr = dst, 707 .saddr = tiph->saddr, 708 .tos = RT_TOS(tos) } }, 709 .oif = tunnel->parms.link, 710 .proto = IPPROTO_IPV6 }; 711 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 712 stats->tx_carrier_errors++; 713 goto tx_error_icmp; 714 } 715 } 716 if (rt->rt_type != RTN_UNICAST) { 717 ip_rt_put(rt); 718 stats->tx_carrier_errors++; 719 goto tx_error_icmp; 720 } 721 tdev = rt->u.dst.dev; 722 723 if (tdev == dev) { 724 ip_rt_put(rt); 725 stats->collisions++; 726 goto tx_error; 727 } 728 729 if (df) { 730 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 731 732 if (mtu < 68) { 733 stats->collisions++; 734 ip_rt_put(rt); 735 goto tx_error; 736 } 737 738 if (mtu < IPV6_MIN_MTU) { 739 mtu = IPV6_MIN_MTU; 740 df = 0; 741 } 742 743 if (tunnel->parms.iph.daddr && skb_dst(skb)) 744 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 745 746 if (skb->len > mtu) { 747 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 748 ip_rt_put(rt); 749 goto tx_error; 750 } 751 } 752 753 if (tunnel->err_count > 0) { 754 if (time_before(jiffies, 755 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 756 tunnel->err_count--; 757 dst_link_failure(skb); 758 } else 759 tunnel->err_count = 0; 760 } 761 762 /* 763 * Okay, now see if we can stuff it in the buffer as-is. 764 */ 765 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 766 767 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 768 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 769 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 770 if (!new_skb) { 771 ip_rt_put(rt); 772 txq->tx_dropped++; 773 dev_kfree_skb(skb); 774 return NETDEV_TX_OK; 775 } 776 if (skb->sk) 777 skb_set_owner_w(new_skb, skb->sk); 778 dev_kfree_skb(skb); 779 skb = new_skb; 780 iph6 = ipv6_hdr(skb); 781 } 782 783 skb->transport_header = skb->network_header; 784 skb_push(skb, sizeof(struct iphdr)); 785 skb_reset_network_header(skb); 786 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 787 IPCB(skb)->flags = 0; 788 skb_dst_drop(skb); 789 skb_dst_set(skb, &rt->u.dst); 790 791 /* 792 * Push down and install the IPIP header. 793 */ 794 795 iph = ip_hdr(skb); 796 iph->version = 4; 797 iph->ihl = sizeof(struct iphdr)>>2; 798 iph->frag_off = df; 799 iph->protocol = IPPROTO_IPV6; 800 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 801 iph->daddr = rt->rt_dst; 802 iph->saddr = rt->rt_src; 803 804 if ((iph->ttl = tiph->ttl) == 0) 805 iph->ttl = iph6->hop_limit; 806 807 nf_reset(skb); 808 809 IPTUNNEL_XMIT(); 810 return NETDEV_TX_OK; 811 812 tx_error_icmp: 813 dst_link_failure(skb); 814 tx_error: 815 stats->tx_errors++; 816 dev_kfree_skb(skb); 817 return NETDEV_TX_OK; 818 } 819 820 static void ipip6_tunnel_bind_dev(struct net_device *dev) 821 { 822 struct net_device *tdev = NULL; 823 struct ip_tunnel *tunnel; 824 struct iphdr *iph; 825 826 tunnel = netdev_priv(dev); 827 iph = &tunnel->parms.iph; 828 829 if (iph->daddr) { 830 struct flowi fl = { .nl_u = { .ip4_u = 831 { .daddr = iph->daddr, 832 .saddr = iph->saddr, 833 .tos = RT_TOS(iph->tos) } }, 834 .oif = tunnel->parms.link, 835 .proto = IPPROTO_IPV6 }; 836 struct rtable *rt; 837 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 838 tdev = rt->u.dst.dev; 839 ip_rt_put(rt); 840 } 841 dev->flags |= IFF_POINTOPOINT; 842 } 843 844 if (!tdev && tunnel->parms.link) 845 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 846 847 if (tdev) { 848 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 849 dev->mtu = tdev->mtu - sizeof(struct iphdr); 850 if (dev->mtu < IPV6_MIN_MTU) 851 dev->mtu = IPV6_MIN_MTU; 852 } 853 dev->iflink = tunnel->parms.link; 854 } 855 856 static int 857 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 858 { 859 int err = 0; 860 struct ip_tunnel_parm p; 861 struct ip_tunnel_prl prl; 862 struct ip_tunnel *t; 863 struct net *net = dev_net(dev); 864 struct sit_net *sitn = net_generic(net, sit_net_id); 865 #ifdef CONFIG_IPV6_SIT_6RD 866 struct ip_tunnel_6rd ip6rd; 867 #endif 868 869 switch (cmd) { 870 case SIOCGETTUNNEL: 871 #ifdef CONFIG_IPV6_SIT_6RD 872 case SIOCGET6RD: 873 #endif 874 t = NULL; 875 if (dev == sitn->fb_tunnel_dev) { 876 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 877 err = -EFAULT; 878 break; 879 } 880 t = ipip6_tunnel_locate(net, &p, 0); 881 } 882 if (t == NULL) 883 t = netdev_priv(dev); 884 885 err = -EFAULT; 886 if (cmd == SIOCGETTUNNEL) { 887 memcpy(&p, &t->parms, sizeof(p)); 888 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 889 sizeof(p))) 890 goto done; 891 #ifdef CONFIG_IPV6_SIT_6RD 892 } else { 893 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 894 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 895 ip6rd.prefixlen = t->ip6rd.prefixlen; 896 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 897 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 898 sizeof(ip6rd))) 899 goto done; 900 #endif 901 } 902 err = 0; 903 break; 904 905 case SIOCADDTUNNEL: 906 case SIOCCHGTUNNEL: 907 err = -EPERM; 908 if (!capable(CAP_NET_ADMIN)) 909 goto done; 910 911 err = -EFAULT; 912 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 913 goto done; 914 915 err = -EINVAL; 916 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 917 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 918 goto done; 919 if (p.iph.ttl) 920 p.iph.frag_off |= htons(IP_DF); 921 922 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 923 924 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 925 if (t != NULL) { 926 if (t->dev != dev) { 927 err = -EEXIST; 928 break; 929 } 930 } else { 931 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 932 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 933 err = -EINVAL; 934 break; 935 } 936 t = netdev_priv(dev); 937 ipip6_tunnel_unlink(sitn, t); 938 t->parms.iph.saddr = p.iph.saddr; 939 t->parms.iph.daddr = p.iph.daddr; 940 memcpy(dev->dev_addr, &p.iph.saddr, 4); 941 memcpy(dev->broadcast, &p.iph.daddr, 4); 942 ipip6_tunnel_link(sitn, t); 943 netdev_state_change(dev); 944 } 945 } 946 947 if (t) { 948 err = 0; 949 if (cmd == SIOCCHGTUNNEL) { 950 t->parms.iph.ttl = p.iph.ttl; 951 t->parms.iph.tos = p.iph.tos; 952 if (t->parms.link != p.link) { 953 t->parms.link = p.link; 954 ipip6_tunnel_bind_dev(dev); 955 netdev_state_change(dev); 956 } 957 } 958 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 959 err = -EFAULT; 960 } else 961 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 962 break; 963 964 case SIOCDELTUNNEL: 965 err = -EPERM; 966 if (!capable(CAP_NET_ADMIN)) 967 goto done; 968 969 if (dev == sitn->fb_tunnel_dev) { 970 err = -EFAULT; 971 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 972 goto done; 973 err = -ENOENT; 974 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 975 goto done; 976 err = -EPERM; 977 if (t == netdev_priv(sitn->fb_tunnel_dev)) 978 goto done; 979 dev = t->dev; 980 } 981 unregister_netdevice(dev); 982 err = 0; 983 break; 984 985 case SIOCGETPRL: 986 err = -EINVAL; 987 if (dev == sitn->fb_tunnel_dev) 988 goto done; 989 err = -ENOENT; 990 if (!(t = netdev_priv(dev))) 991 goto done; 992 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 993 break; 994 995 case SIOCADDPRL: 996 case SIOCDELPRL: 997 case SIOCCHGPRL: 998 err = -EPERM; 999 if (!capable(CAP_NET_ADMIN)) 1000 goto done; 1001 err = -EINVAL; 1002 if (dev == sitn->fb_tunnel_dev) 1003 goto done; 1004 err = -EFAULT; 1005 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1006 goto done; 1007 err = -ENOENT; 1008 if (!(t = netdev_priv(dev))) 1009 goto done; 1010 1011 switch (cmd) { 1012 case SIOCDELPRL: 1013 err = ipip6_tunnel_del_prl(t, &prl); 1014 break; 1015 case SIOCADDPRL: 1016 case SIOCCHGPRL: 1017 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1018 break; 1019 } 1020 netdev_state_change(dev); 1021 break; 1022 1023 #ifdef CONFIG_IPV6_SIT_6RD 1024 case SIOCADD6RD: 1025 case SIOCCHG6RD: 1026 case SIOCDEL6RD: 1027 err = -EPERM; 1028 if (!capable(CAP_NET_ADMIN)) 1029 goto done; 1030 1031 err = -EFAULT; 1032 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1033 sizeof(ip6rd))) 1034 goto done; 1035 1036 t = netdev_priv(dev); 1037 1038 if (cmd != SIOCDEL6RD) { 1039 struct in6_addr prefix; 1040 __be32 relay_prefix; 1041 1042 err = -EINVAL; 1043 if (ip6rd.relay_prefixlen > 32 || 1044 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1045 goto done; 1046 1047 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1048 ip6rd.prefixlen); 1049 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1050 goto done; 1051 if (ip6rd.relay_prefixlen) 1052 relay_prefix = ip6rd.relay_prefix & 1053 htonl(0xffffffffUL << 1054 (32 - ip6rd.relay_prefixlen)); 1055 else 1056 relay_prefix = 0; 1057 if (relay_prefix != ip6rd.relay_prefix) 1058 goto done; 1059 1060 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1061 t->ip6rd.relay_prefix = relay_prefix; 1062 t->ip6rd.prefixlen = ip6rd.prefixlen; 1063 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1064 } else 1065 ipip6_tunnel_clone_6rd(dev, sitn); 1066 1067 err = 0; 1068 break; 1069 #endif 1070 1071 default: 1072 err = -EINVAL; 1073 } 1074 1075 done: 1076 return err; 1077 } 1078 1079 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1080 { 1081 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1082 return -EINVAL; 1083 dev->mtu = new_mtu; 1084 return 0; 1085 } 1086 1087 static const struct net_device_ops ipip6_netdev_ops = { 1088 .ndo_uninit = ipip6_tunnel_uninit, 1089 .ndo_start_xmit = ipip6_tunnel_xmit, 1090 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1091 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1092 }; 1093 1094 static void ipip6_tunnel_setup(struct net_device *dev) 1095 { 1096 dev->netdev_ops = &ipip6_netdev_ops; 1097 dev->destructor = free_netdev; 1098 1099 dev->type = ARPHRD_SIT; 1100 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1101 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1102 dev->flags = IFF_NOARP; 1103 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1104 dev->iflink = 0; 1105 dev->addr_len = 4; 1106 dev->features |= NETIF_F_NETNS_LOCAL; 1107 } 1108 1109 static void ipip6_tunnel_init(struct net_device *dev) 1110 { 1111 struct ip_tunnel *tunnel = netdev_priv(dev); 1112 1113 tunnel->dev = dev; 1114 strcpy(tunnel->parms.name, dev->name); 1115 1116 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1117 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1118 1119 ipip6_tunnel_bind_dev(dev); 1120 } 1121 1122 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1123 { 1124 struct ip_tunnel *tunnel = netdev_priv(dev); 1125 struct iphdr *iph = &tunnel->parms.iph; 1126 struct net *net = dev_net(dev); 1127 struct sit_net *sitn = net_generic(net, sit_net_id); 1128 1129 tunnel->dev = dev; 1130 strcpy(tunnel->parms.name, dev->name); 1131 1132 iph->version = 4; 1133 iph->protocol = IPPROTO_IPV6; 1134 iph->ihl = 5; 1135 iph->ttl = 64; 1136 1137 dev_hold(dev); 1138 sitn->tunnels_wc[0] = tunnel; 1139 } 1140 1141 static struct xfrm_tunnel sit_handler = { 1142 .handler = ipip6_rcv, 1143 .err_handler = ipip6_err, 1144 .priority = 1, 1145 }; 1146 1147 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1148 { 1149 int prio; 1150 1151 for (prio = 1; prio < 4; prio++) { 1152 int h; 1153 for (h = 0; h < HASH_SIZE; h++) { 1154 struct ip_tunnel *t = sitn->tunnels[prio][h]; 1155 1156 while (t != NULL) { 1157 unregister_netdevice_queue(t->dev, head); 1158 t = t->next; 1159 } 1160 } 1161 } 1162 } 1163 1164 static int __net_init sit_init_net(struct net *net) 1165 { 1166 struct sit_net *sitn = net_generic(net, sit_net_id); 1167 int err; 1168 1169 sitn->tunnels[0] = sitn->tunnels_wc; 1170 sitn->tunnels[1] = sitn->tunnels_l; 1171 sitn->tunnels[2] = sitn->tunnels_r; 1172 sitn->tunnels[3] = sitn->tunnels_r_l; 1173 1174 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1175 ipip6_tunnel_setup); 1176 if (!sitn->fb_tunnel_dev) { 1177 err = -ENOMEM; 1178 goto err_alloc_dev; 1179 } 1180 dev_net_set(sitn->fb_tunnel_dev, net); 1181 1182 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1183 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1184 1185 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1186 goto err_reg_dev; 1187 1188 return 0; 1189 1190 err_reg_dev: 1191 dev_put(sitn->fb_tunnel_dev); 1192 free_netdev(sitn->fb_tunnel_dev); 1193 err_alloc_dev: 1194 return err; 1195 } 1196 1197 static void __net_exit sit_exit_net(struct net *net) 1198 { 1199 struct sit_net *sitn = net_generic(net, sit_net_id); 1200 LIST_HEAD(list); 1201 1202 rtnl_lock(); 1203 sit_destroy_tunnels(sitn, &list); 1204 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1205 unregister_netdevice_many(&list); 1206 rtnl_unlock(); 1207 } 1208 1209 static struct pernet_operations sit_net_ops = { 1210 .init = sit_init_net, 1211 .exit = sit_exit_net, 1212 .id = &sit_net_id, 1213 .size = sizeof(struct sit_net), 1214 }; 1215 1216 static void __exit sit_cleanup(void) 1217 { 1218 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1219 1220 unregister_pernet_device(&sit_net_ops); 1221 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1222 } 1223 1224 static int __init sit_init(void) 1225 { 1226 int err; 1227 1228 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1229 1230 err = register_pernet_device(&sit_net_ops); 1231 if (err < 0) 1232 return err; 1233 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1234 if (err < 0) { 1235 unregister_pernet_device(&sit_net_ops); 1236 printk(KERN_INFO "sit init: Can't add protocol\n"); 1237 } 1238 return err; 1239 } 1240 1241 module_init(sit_init); 1242 module_exit(sit_cleanup); 1243 MODULE_LICENSE("GPL"); 1244 MODULE_ALIAS("sit0"); 1245