1 /* 2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT) 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 * 14 * Changes: 15 * Roger Venning <r.venning@telstra.com>: 6to4 support 16 * Nate Thompson <nate@thebog.net>: 6to4 support 17 * Fred Templin <fred.l.templin@boeing.com>: isatap support 18 */ 19 20 #include <linux/module.h> 21 #include <linux/capability.h> 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/socket.h> 25 #include <linux/sockios.h> 26 #include <linux/net.h> 27 #include <linux/in6.h> 28 #include <linux/netdevice.h> 29 #include <linux/if_arp.h> 30 #include <linux/icmp.h> 31 #include <asm/uaccess.h> 32 #include <linux/init.h> 33 #include <linux/netfilter_ipv4.h> 34 #include <linux/if_ether.h> 35 36 #include <net/sock.h> 37 #include <net/snmp.h> 38 39 #include <net/ipv6.h> 40 #include <net/protocol.h> 41 #include <net/transp_v6.h> 42 #include <net/ip6_fib.h> 43 #include <net/ip6_route.h> 44 #include <net/ndisc.h> 45 #include <net/addrconf.h> 46 #include <net/ip.h> 47 #include <net/udp.h> 48 #include <net/icmp.h> 49 #include <net/ipip.h> 50 #include <net/inet_ecn.h> 51 #include <net/xfrm.h> 52 #include <net/dsfield.h> 53 #include <net/net_namespace.h> 54 #include <net/netns/generic.h> 55 56 /* 57 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 58 59 For comments look at net/ipv4/ip_gre.c --ANK 60 */ 61 62 #define HASH_SIZE 16 63 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 64 65 static void ipip6_tunnel_init(struct net_device *dev); 66 static void ipip6_tunnel_setup(struct net_device *dev); 67 68 static int sit_net_id __read_mostly; 69 struct sit_net { 70 struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 71 struct ip_tunnel *tunnels_r[HASH_SIZE]; 72 struct ip_tunnel *tunnels_l[HASH_SIZE]; 73 struct ip_tunnel *tunnels_wc[1]; 74 struct ip_tunnel **tunnels[4]; 75 76 struct net_device *fb_tunnel_dev; 77 }; 78 79 /* 80 * Locking : hash tables are protected by RCU and a spinlock 81 */ 82 static DEFINE_SPINLOCK(ipip6_lock); 83 84 #define for_each_ip_tunnel_rcu(start) \ 85 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 86 87 /* 88 * Must be invoked with rcu_read_lock 89 */ 90 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, 91 struct net_device *dev, __be32 remote, __be32 local) 92 { 93 unsigned h0 = HASH(remote); 94 unsigned h1 = HASH(local); 95 struct ip_tunnel *t; 96 struct sit_net *sitn = net_generic(net, sit_net_id); 97 98 for_each_ip_tunnel_rcu(sitn->tunnels_r_l[h0 ^ h1]) { 99 if (local == t->parms.iph.saddr && 100 remote == t->parms.iph.daddr && 101 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 102 (t->dev->flags & IFF_UP)) 103 return t; 104 } 105 for_each_ip_tunnel_rcu(sitn->tunnels_r[h0]) { 106 if (remote == t->parms.iph.daddr && 107 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 108 (t->dev->flags & IFF_UP)) 109 return t; 110 } 111 for_each_ip_tunnel_rcu(sitn->tunnels_l[h1]) { 112 if (local == t->parms.iph.saddr && 113 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 114 (t->dev->flags & IFF_UP)) 115 return t; 116 } 117 t = rcu_dereference(sitn->tunnels_wc[0]); 118 if ((t != NULL) && (t->dev->flags & IFF_UP)) 119 return t; 120 return NULL; 121 } 122 123 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn, 124 struct ip_tunnel_parm *parms) 125 { 126 __be32 remote = parms->iph.daddr; 127 __be32 local = parms->iph.saddr; 128 unsigned h = 0; 129 int prio = 0; 130 131 if (remote) { 132 prio |= 2; 133 h ^= HASH(remote); 134 } 135 if (local) { 136 prio |= 1; 137 h ^= HASH(local); 138 } 139 return &sitn->tunnels[prio][h]; 140 } 141 142 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn, 143 struct ip_tunnel *t) 144 { 145 return __ipip6_bucket(sitn, &t->parms); 146 } 147 148 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 149 { 150 struct ip_tunnel **tp; 151 152 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) { 153 if (t == *tp) { 154 spin_lock_bh(&ipip6_lock); 155 *tp = t->next; 156 spin_unlock_bh(&ipip6_lock); 157 break; 158 } 159 } 160 } 161 162 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 163 { 164 struct ip_tunnel **tp = ipip6_bucket(sitn, t); 165 166 spin_lock_bh(&ipip6_lock); 167 t->next = *tp; 168 rcu_assign_pointer(*tp, t); 169 spin_unlock_bh(&ipip6_lock); 170 } 171 172 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 173 { 174 #ifdef CONFIG_IPV6_SIT_6RD 175 struct ip_tunnel *t = netdev_priv(dev); 176 177 if (t->dev == sitn->fb_tunnel_dev) { 178 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 179 t->ip6rd.relay_prefix = 0; 180 t->ip6rd.prefixlen = 16; 181 t->ip6rd.relay_prefixlen = 0; 182 } else { 183 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 184 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 185 } 186 #endif 187 } 188 189 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net, 190 struct ip_tunnel_parm *parms, int create) 191 { 192 __be32 remote = parms->iph.daddr; 193 __be32 local = parms->iph.saddr; 194 struct ip_tunnel *t, **tp, *nt; 195 struct net_device *dev; 196 char name[IFNAMSIZ]; 197 struct sit_net *sitn = net_generic(net, sit_net_id); 198 199 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) { 200 if (local == t->parms.iph.saddr && 201 remote == t->parms.iph.daddr && 202 parms->link == t->parms.link) { 203 if (create) 204 return NULL; 205 else 206 return t; 207 } 208 } 209 if (!create) 210 goto failed; 211 212 if (parms->name[0]) 213 strlcpy(name, parms->name, IFNAMSIZ); 214 else 215 sprintf(name, "sit%%d"); 216 217 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 218 if (dev == NULL) 219 return NULL; 220 221 dev_net_set(dev, net); 222 223 if (strchr(name, '%')) { 224 if (dev_alloc_name(dev, name) < 0) 225 goto failed_free; 226 } 227 228 nt = netdev_priv(dev); 229 230 nt->parms = *parms; 231 ipip6_tunnel_init(dev); 232 ipip6_tunnel_clone_6rd(dev, sitn); 233 234 if (parms->i_flags & SIT_ISATAP) 235 dev->priv_flags |= IFF_ISATAP; 236 237 if (register_netdevice(dev) < 0) 238 goto failed_free; 239 240 dev_hold(dev); 241 242 ipip6_tunnel_link(sitn, nt); 243 return nt; 244 245 failed_free: 246 free_netdev(dev); 247 failed: 248 return NULL; 249 } 250 251 static DEFINE_SPINLOCK(ipip6_prl_lock); 252 253 #define for_each_prl_rcu(start) \ 254 for (prl = rcu_dereference(start); \ 255 prl; \ 256 prl = rcu_dereference(prl->next)) 257 258 static struct ip_tunnel_prl_entry * 259 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 260 { 261 struct ip_tunnel_prl_entry *prl; 262 263 for_each_prl_rcu(t->prl) 264 if (prl->addr == addr) 265 break; 266 return prl; 267 268 } 269 270 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 271 struct ip_tunnel_prl __user *a) 272 { 273 struct ip_tunnel_prl kprl, *kp; 274 struct ip_tunnel_prl_entry *prl; 275 unsigned int cmax, c = 0, ca, len; 276 int ret = 0; 277 278 if (copy_from_user(&kprl, a, sizeof(kprl))) 279 return -EFAULT; 280 cmax = kprl.datalen / sizeof(kprl); 281 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 282 cmax = 1; 283 284 /* For simple GET or for root users, 285 * we try harder to allocate. 286 */ 287 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 288 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 289 NULL; 290 291 rcu_read_lock(); 292 293 ca = t->prl_count < cmax ? t->prl_count : cmax; 294 295 if (!kp) { 296 /* We don't try hard to allocate much memory for 297 * non-root users. 298 * For root users, retry allocating enough memory for 299 * the answer. 300 */ 301 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 302 if (!kp) { 303 ret = -ENOMEM; 304 goto out; 305 } 306 } 307 308 c = 0; 309 for_each_prl_rcu(t->prl) { 310 if (c >= cmax) 311 break; 312 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 313 continue; 314 kp[c].addr = prl->addr; 315 kp[c].flags = prl->flags; 316 c++; 317 if (kprl.addr != htonl(INADDR_ANY)) 318 break; 319 } 320 out: 321 rcu_read_unlock(); 322 323 len = sizeof(*kp) * c; 324 ret = 0; 325 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 326 ret = -EFAULT; 327 328 kfree(kp); 329 330 return ret; 331 } 332 333 static int 334 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 335 { 336 struct ip_tunnel_prl_entry *p; 337 int err = 0; 338 339 if (a->addr == htonl(INADDR_ANY)) 340 return -EINVAL; 341 342 spin_lock(&ipip6_prl_lock); 343 344 for (p = t->prl; p; p = p->next) { 345 if (p->addr == a->addr) { 346 if (chg) { 347 p->flags = a->flags; 348 goto out; 349 } 350 err = -EEXIST; 351 goto out; 352 } 353 } 354 355 if (chg) { 356 err = -ENXIO; 357 goto out; 358 } 359 360 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 361 if (!p) { 362 err = -ENOBUFS; 363 goto out; 364 } 365 366 p->next = t->prl; 367 p->addr = a->addr; 368 p->flags = a->flags; 369 t->prl_count++; 370 rcu_assign_pointer(t->prl, p); 371 out: 372 spin_unlock(&ipip6_prl_lock); 373 return err; 374 } 375 376 static void prl_entry_destroy_rcu(struct rcu_head *head) 377 { 378 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head)); 379 } 380 381 static void prl_list_destroy_rcu(struct rcu_head *head) 382 { 383 struct ip_tunnel_prl_entry *p, *n; 384 385 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 386 do { 387 n = p->next; 388 kfree(p); 389 p = n; 390 } while (p); 391 } 392 393 static int 394 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 395 { 396 struct ip_tunnel_prl_entry *x, **p; 397 int err = 0; 398 399 spin_lock(&ipip6_prl_lock); 400 401 if (a && a->addr != htonl(INADDR_ANY)) { 402 for (p = &t->prl; *p; p = &(*p)->next) { 403 if ((*p)->addr == a->addr) { 404 x = *p; 405 *p = x->next; 406 call_rcu(&x->rcu_head, prl_entry_destroy_rcu); 407 t->prl_count--; 408 goto out; 409 } 410 } 411 err = -ENXIO; 412 } else { 413 if (t->prl) { 414 t->prl_count = 0; 415 x = t->prl; 416 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 417 t->prl = NULL; 418 } 419 } 420 out: 421 spin_unlock(&ipip6_prl_lock); 422 return err; 423 } 424 425 static int 426 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 427 { 428 struct ip_tunnel_prl_entry *p; 429 int ok = 1; 430 431 rcu_read_lock(); 432 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 433 if (p) { 434 if (p->flags & PRL_DEFAULT) 435 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 436 else 437 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 438 } else { 439 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 440 if (ipv6_addr_is_isatap(addr6) && 441 (addr6->s6_addr32[3] == iph->saddr) && 442 ipv6_chk_prefix(addr6, t->dev)) 443 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 444 else 445 ok = 0; 446 } 447 rcu_read_unlock(); 448 return ok; 449 } 450 451 static void ipip6_tunnel_uninit(struct net_device *dev) 452 { 453 struct net *net = dev_net(dev); 454 struct sit_net *sitn = net_generic(net, sit_net_id); 455 456 if (dev == sitn->fb_tunnel_dev) { 457 spin_lock_bh(&ipip6_lock); 458 sitn->tunnels_wc[0] = NULL; 459 spin_unlock_bh(&ipip6_lock); 460 dev_put(dev); 461 } else { 462 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 463 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 464 dev_put(dev); 465 } 466 } 467 468 469 static int ipip6_err(struct sk_buff *skb, u32 info) 470 { 471 472 /* All the routers (except for Linux) return only 473 8 bytes of packet payload. It means, that precise relaying of 474 ICMP in the real Internet is absolutely infeasible. 475 */ 476 struct iphdr *iph = (struct iphdr*)skb->data; 477 const int type = icmp_hdr(skb)->type; 478 const int code = icmp_hdr(skb)->code; 479 struct ip_tunnel *t; 480 int err; 481 482 switch (type) { 483 default: 484 case ICMP_PARAMETERPROB: 485 return 0; 486 487 case ICMP_DEST_UNREACH: 488 switch (code) { 489 case ICMP_SR_FAILED: 490 case ICMP_PORT_UNREACH: 491 /* Impossible event. */ 492 return 0; 493 case ICMP_FRAG_NEEDED: 494 /* Soft state for pmtu is maintained by IP core. */ 495 return 0; 496 default: 497 /* All others are translated to HOST_UNREACH. 498 rfc2003 contains "deep thoughts" about NET_UNREACH, 499 I believe they are just ether pollution. --ANK 500 */ 501 break; 502 } 503 break; 504 case ICMP_TIME_EXCEEDED: 505 if (code != ICMP_EXC_TTL) 506 return 0; 507 break; 508 } 509 510 err = -ENOENT; 511 512 rcu_read_lock(); 513 t = ipip6_tunnel_lookup(dev_net(skb->dev), 514 skb->dev, 515 iph->daddr, 516 iph->saddr); 517 if (t == NULL || t->parms.iph.daddr == 0) 518 goto out; 519 520 err = 0; 521 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 522 goto out; 523 524 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 525 t->err_count++; 526 else 527 t->err_count = 1; 528 t->err_time = jiffies; 529 out: 530 rcu_read_unlock(); 531 return err; 532 } 533 534 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 535 { 536 if (INET_ECN_is_ce(iph->tos)) 537 IP6_ECN_set_ce(ipv6_hdr(skb)); 538 } 539 540 static int ipip6_rcv(struct sk_buff *skb) 541 { 542 struct iphdr *iph; 543 struct ip_tunnel *tunnel; 544 545 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 546 goto out; 547 548 iph = ip_hdr(skb); 549 550 rcu_read_lock(); 551 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 552 iph->saddr, iph->daddr); 553 if (tunnel != NULL) { 554 secpath_reset(skb); 555 skb->mac_header = skb->network_header; 556 skb_reset_network_header(skb); 557 IPCB(skb)->flags = 0; 558 skb->protocol = htons(ETH_P_IPV6); 559 skb->pkt_type = PACKET_HOST; 560 561 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 562 !isatap_chksrc(skb, iph, tunnel)) { 563 tunnel->dev->stats.rx_errors++; 564 rcu_read_unlock(); 565 kfree_skb(skb); 566 return 0; 567 } 568 tunnel->dev->stats.rx_packets++; 569 tunnel->dev->stats.rx_bytes += skb->len; 570 skb->dev = tunnel->dev; 571 skb_dst_drop(skb); 572 nf_reset(skb); 573 ipip6_ecn_decapsulate(iph, skb); 574 netif_rx(skb); 575 rcu_read_unlock(); 576 return 0; 577 } 578 579 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 580 rcu_read_unlock(); 581 out: 582 kfree_skb(skb); 583 return 0; 584 } 585 586 /* 587 * Returns the embedded IPv4 address if the IPv6 address 588 * comes from 6rd / 6to4 (RFC 3056) addr space. 589 */ 590 static inline 591 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel) 592 { 593 __be32 dst = 0; 594 595 #ifdef CONFIG_IPV6_SIT_6RD 596 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 597 tunnel->ip6rd.prefixlen)) { 598 unsigned pbw0, pbi0; 599 int pbi1; 600 u32 d; 601 602 pbw0 = tunnel->ip6rd.prefixlen >> 5; 603 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 604 605 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 606 tunnel->ip6rd.relay_prefixlen; 607 608 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 609 if (pbi1 > 0) 610 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 611 (32 - pbi1); 612 613 dst = tunnel->ip6rd.relay_prefix | htonl(d); 614 } 615 #else 616 if (v6dst->s6_addr16[0] == htons(0x2002)) { 617 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 618 memcpy(&dst, &v6dst->s6_addr16[1], 4); 619 } 620 #endif 621 return dst; 622 } 623 624 /* 625 * This function assumes it is being called from dev_queue_xmit() 626 * and that skb is filled properly by that function. 627 */ 628 629 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 630 struct net_device *dev) 631 { 632 struct ip_tunnel *tunnel = netdev_priv(dev); 633 struct net_device_stats *stats = &dev->stats; 634 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); 635 struct iphdr *tiph = &tunnel->parms.iph; 636 struct ipv6hdr *iph6 = ipv6_hdr(skb); 637 u8 tos = tunnel->parms.iph.tos; 638 __be16 df = tiph->frag_off; 639 struct rtable *rt; /* Route to the other host */ 640 struct net_device *tdev; /* Device to other host */ 641 struct iphdr *iph; /* Our new IP header */ 642 unsigned int max_headroom; /* The extra header space needed */ 643 __be32 dst = tiph->daddr; 644 int mtu; 645 struct in6_addr *addr6; 646 int addr_type; 647 648 if (skb->protocol != htons(ETH_P_IPV6)) 649 goto tx_error; 650 651 /* ISATAP (RFC4214) - must come before 6to4 */ 652 if (dev->priv_flags & IFF_ISATAP) { 653 struct neighbour *neigh = NULL; 654 655 if (skb_dst(skb)) 656 neigh = skb_dst(skb)->neighbour; 657 658 if (neigh == NULL) { 659 if (net_ratelimit()) 660 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 661 goto tx_error; 662 } 663 664 addr6 = (struct in6_addr*)&neigh->primary_key; 665 addr_type = ipv6_addr_type(addr6); 666 667 if ((addr_type & IPV6_ADDR_UNICAST) && 668 ipv6_addr_is_isatap(addr6)) 669 dst = addr6->s6_addr32[3]; 670 else 671 goto tx_error; 672 } 673 674 if (!dst) 675 dst = try_6rd(&iph6->daddr, tunnel); 676 677 if (!dst) { 678 struct neighbour *neigh = NULL; 679 680 if (skb_dst(skb)) 681 neigh = skb_dst(skb)->neighbour; 682 683 if (neigh == NULL) { 684 if (net_ratelimit()) 685 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 686 goto tx_error; 687 } 688 689 addr6 = (struct in6_addr*)&neigh->primary_key; 690 addr_type = ipv6_addr_type(addr6); 691 692 if (addr_type == IPV6_ADDR_ANY) { 693 addr6 = &ipv6_hdr(skb)->daddr; 694 addr_type = ipv6_addr_type(addr6); 695 } 696 697 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 698 goto tx_error_icmp; 699 700 dst = addr6->s6_addr32[3]; 701 } 702 703 { 704 struct flowi fl = { .nl_u = { .ip4_u = 705 { .daddr = dst, 706 .saddr = tiph->saddr, 707 .tos = RT_TOS(tos) } }, 708 .oif = tunnel->parms.link, 709 .proto = IPPROTO_IPV6 }; 710 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 711 stats->tx_carrier_errors++; 712 goto tx_error_icmp; 713 } 714 } 715 if (rt->rt_type != RTN_UNICAST) { 716 ip_rt_put(rt); 717 stats->tx_carrier_errors++; 718 goto tx_error_icmp; 719 } 720 tdev = rt->u.dst.dev; 721 722 if (tdev == dev) { 723 ip_rt_put(rt); 724 stats->collisions++; 725 goto tx_error; 726 } 727 728 if (df) { 729 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 730 731 if (mtu < 68) { 732 stats->collisions++; 733 ip_rt_put(rt); 734 goto tx_error; 735 } 736 737 if (mtu < IPV6_MIN_MTU) { 738 mtu = IPV6_MIN_MTU; 739 df = 0; 740 } 741 742 if (tunnel->parms.iph.daddr && skb_dst(skb)) 743 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 744 745 if (skb->len > mtu) { 746 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 747 ip_rt_put(rt); 748 goto tx_error; 749 } 750 } 751 752 if (tunnel->err_count > 0) { 753 if (time_before(jiffies, 754 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 755 tunnel->err_count--; 756 dst_link_failure(skb); 757 } else 758 tunnel->err_count = 0; 759 } 760 761 /* 762 * Okay, now see if we can stuff it in the buffer as-is. 763 */ 764 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 765 766 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 767 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 768 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 769 if (!new_skb) { 770 ip_rt_put(rt); 771 txq->tx_dropped++; 772 dev_kfree_skb(skb); 773 return NETDEV_TX_OK; 774 } 775 if (skb->sk) 776 skb_set_owner_w(new_skb, skb->sk); 777 dev_kfree_skb(skb); 778 skb = new_skb; 779 iph6 = ipv6_hdr(skb); 780 } 781 782 skb->transport_header = skb->network_header; 783 skb_push(skb, sizeof(struct iphdr)); 784 skb_reset_network_header(skb); 785 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 786 IPCB(skb)->flags = 0; 787 skb_dst_drop(skb); 788 skb_dst_set(skb, &rt->u.dst); 789 790 /* 791 * Push down and install the IPIP header. 792 */ 793 794 iph = ip_hdr(skb); 795 iph->version = 4; 796 iph->ihl = sizeof(struct iphdr)>>2; 797 iph->frag_off = df; 798 iph->protocol = IPPROTO_IPV6; 799 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 800 iph->daddr = rt->rt_dst; 801 iph->saddr = rt->rt_src; 802 803 if ((iph->ttl = tiph->ttl) == 0) 804 iph->ttl = iph6->hop_limit; 805 806 nf_reset(skb); 807 808 IPTUNNEL_XMIT(); 809 return NETDEV_TX_OK; 810 811 tx_error_icmp: 812 dst_link_failure(skb); 813 tx_error: 814 stats->tx_errors++; 815 dev_kfree_skb(skb); 816 return NETDEV_TX_OK; 817 } 818 819 static void ipip6_tunnel_bind_dev(struct net_device *dev) 820 { 821 struct net_device *tdev = NULL; 822 struct ip_tunnel *tunnel; 823 struct iphdr *iph; 824 825 tunnel = netdev_priv(dev); 826 iph = &tunnel->parms.iph; 827 828 if (iph->daddr) { 829 struct flowi fl = { .nl_u = { .ip4_u = 830 { .daddr = iph->daddr, 831 .saddr = iph->saddr, 832 .tos = RT_TOS(iph->tos) } }, 833 .oif = tunnel->parms.link, 834 .proto = IPPROTO_IPV6 }; 835 struct rtable *rt; 836 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 837 tdev = rt->u.dst.dev; 838 ip_rt_put(rt); 839 } 840 dev->flags |= IFF_POINTOPOINT; 841 } 842 843 if (!tdev && tunnel->parms.link) 844 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 845 846 if (tdev) { 847 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 848 dev->mtu = tdev->mtu - sizeof(struct iphdr); 849 if (dev->mtu < IPV6_MIN_MTU) 850 dev->mtu = IPV6_MIN_MTU; 851 } 852 dev->iflink = tunnel->parms.link; 853 } 854 855 static int 856 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 857 { 858 int err = 0; 859 struct ip_tunnel_parm p; 860 struct ip_tunnel_prl prl; 861 struct ip_tunnel *t; 862 struct net *net = dev_net(dev); 863 struct sit_net *sitn = net_generic(net, sit_net_id); 864 #ifdef CONFIG_IPV6_SIT_6RD 865 struct ip_tunnel_6rd ip6rd; 866 #endif 867 868 switch (cmd) { 869 case SIOCGETTUNNEL: 870 #ifdef CONFIG_IPV6_SIT_6RD 871 case SIOCGET6RD: 872 #endif 873 t = NULL; 874 if (dev == sitn->fb_tunnel_dev) { 875 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 876 err = -EFAULT; 877 break; 878 } 879 t = ipip6_tunnel_locate(net, &p, 0); 880 } 881 if (t == NULL) 882 t = netdev_priv(dev); 883 884 err = -EFAULT; 885 if (cmd == SIOCGETTUNNEL) { 886 memcpy(&p, &t->parms, sizeof(p)); 887 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 888 sizeof(p))) 889 goto done; 890 #ifdef CONFIG_IPV6_SIT_6RD 891 } else { 892 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 893 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 894 ip6rd.prefixlen = t->ip6rd.prefixlen; 895 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 896 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 897 sizeof(ip6rd))) 898 goto done; 899 #endif 900 } 901 err = 0; 902 break; 903 904 case SIOCADDTUNNEL: 905 case SIOCCHGTUNNEL: 906 err = -EPERM; 907 if (!capable(CAP_NET_ADMIN)) 908 goto done; 909 910 err = -EFAULT; 911 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 912 goto done; 913 914 err = -EINVAL; 915 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 916 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 917 goto done; 918 if (p.iph.ttl) 919 p.iph.frag_off |= htons(IP_DF); 920 921 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 922 923 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 924 if (t != NULL) { 925 if (t->dev != dev) { 926 err = -EEXIST; 927 break; 928 } 929 } else { 930 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 931 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 932 err = -EINVAL; 933 break; 934 } 935 t = netdev_priv(dev); 936 ipip6_tunnel_unlink(sitn, t); 937 t->parms.iph.saddr = p.iph.saddr; 938 t->parms.iph.daddr = p.iph.daddr; 939 memcpy(dev->dev_addr, &p.iph.saddr, 4); 940 memcpy(dev->broadcast, &p.iph.daddr, 4); 941 ipip6_tunnel_link(sitn, t); 942 netdev_state_change(dev); 943 } 944 } 945 946 if (t) { 947 err = 0; 948 if (cmd == SIOCCHGTUNNEL) { 949 t->parms.iph.ttl = p.iph.ttl; 950 t->parms.iph.tos = p.iph.tos; 951 if (t->parms.link != p.link) { 952 t->parms.link = p.link; 953 ipip6_tunnel_bind_dev(dev); 954 netdev_state_change(dev); 955 } 956 } 957 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 958 err = -EFAULT; 959 } else 960 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 961 break; 962 963 case SIOCDELTUNNEL: 964 err = -EPERM; 965 if (!capable(CAP_NET_ADMIN)) 966 goto done; 967 968 if (dev == sitn->fb_tunnel_dev) { 969 err = -EFAULT; 970 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 971 goto done; 972 err = -ENOENT; 973 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 974 goto done; 975 err = -EPERM; 976 if (t == netdev_priv(sitn->fb_tunnel_dev)) 977 goto done; 978 dev = t->dev; 979 } 980 unregister_netdevice(dev); 981 err = 0; 982 break; 983 984 case SIOCGETPRL: 985 err = -EINVAL; 986 if (dev == sitn->fb_tunnel_dev) 987 goto done; 988 err = -ENOENT; 989 if (!(t = netdev_priv(dev))) 990 goto done; 991 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 992 break; 993 994 case SIOCADDPRL: 995 case SIOCDELPRL: 996 case SIOCCHGPRL: 997 err = -EPERM; 998 if (!capable(CAP_NET_ADMIN)) 999 goto done; 1000 err = -EINVAL; 1001 if (dev == sitn->fb_tunnel_dev) 1002 goto done; 1003 err = -EFAULT; 1004 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1005 goto done; 1006 err = -ENOENT; 1007 if (!(t = netdev_priv(dev))) 1008 goto done; 1009 1010 switch (cmd) { 1011 case SIOCDELPRL: 1012 err = ipip6_tunnel_del_prl(t, &prl); 1013 break; 1014 case SIOCADDPRL: 1015 case SIOCCHGPRL: 1016 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1017 break; 1018 } 1019 netdev_state_change(dev); 1020 break; 1021 1022 #ifdef CONFIG_IPV6_SIT_6RD 1023 case SIOCADD6RD: 1024 case SIOCCHG6RD: 1025 case SIOCDEL6RD: 1026 err = -EPERM; 1027 if (!capable(CAP_NET_ADMIN)) 1028 goto done; 1029 1030 err = -EFAULT; 1031 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1032 sizeof(ip6rd))) 1033 goto done; 1034 1035 t = netdev_priv(dev); 1036 1037 if (cmd != SIOCDEL6RD) { 1038 struct in6_addr prefix; 1039 __be32 relay_prefix; 1040 1041 err = -EINVAL; 1042 if (ip6rd.relay_prefixlen > 32 || 1043 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1044 goto done; 1045 1046 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1047 ip6rd.prefixlen); 1048 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1049 goto done; 1050 if (ip6rd.relay_prefixlen) 1051 relay_prefix = ip6rd.relay_prefix & 1052 htonl(0xffffffffUL << 1053 (32 - ip6rd.relay_prefixlen)); 1054 else 1055 relay_prefix = 0; 1056 if (relay_prefix != ip6rd.relay_prefix) 1057 goto done; 1058 1059 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1060 t->ip6rd.relay_prefix = relay_prefix; 1061 t->ip6rd.prefixlen = ip6rd.prefixlen; 1062 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1063 } else 1064 ipip6_tunnel_clone_6rd(dev, sitn); 1065 1066 err = 0; 1067 break; 1068 #endif 1069 1070 default: 1071 err = -EINVAL; 1072 } 1073 1074 done: 1075 return err; 1076 } 1077 1078 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1079 { 1080 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1081 return -EINVAL; 1082 dev->mtu = new_mtu; 1083 return 0; 1084 } 1085 1086 static const struct net_device_ops ipip6_netdev_ops = { 1087 .ndo_uninit = ipip6_tunnel_uninit, 1088 .ndo_start_xmit = ipip6_tunnel_xmit, 1089 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1090 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1091 }; 1092 1093 static void ipip6_tunnel_setup(struct net_device *dev) 1094 { 1095 dev->netdev_ops = &ipip6_netdev_ops; 1096 dev->destructor = free_netdev; 1097 1098 dev->type = ARPHRD_SIT; 1099 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1100 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1101 dev->flags = IFF_NOARP; 1102 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1103 dev->iflink = 0; 1104 dev->addr_len = 4; 1105 dev->features |= NETIF_F_NETNS_LOCAL; 1106 } 1107 1108 static void ipip6_tunnel_init(struct net_device *dev) 1109 { 1110 struct ip_tunnel *tunnel = netdev_priv(dev); 1111 1112 tunnel->dev = dev; 1113 strcpy(tunnel->parms.name, dev->name); 1114 1115 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1116 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1117 1118 ipip6_tunnel_bind_dev(dev); 1119 } 1120 1121 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1122 { 1123 struct ip_tunnel *tunnel = netdev_priv(dev); 1124 struct iphdr *iph = &tunnel->parms.iph; 1125 struct net *net = dev_net(dev); 1126 struct sit_net *sitn = net_generic(net, sit_net_id); 1127 1128 tunnel->dev = dev; 1129 strcpy(tunnel->parms.name, dev->name); 1130 1131 iph->version = 4; 1132 iph->protocol = IPPROTO_IPV6; 1133 iph->ihl = 5; 1134 iph->ttl = 64; 1135 1136 dev_hold(dev); 1137 sitn->tunnels_wc[0] = tunnel; 1138 } 1139 1140 static struct xfrm_tunnel sit_handler = { 1141 .handler = ipip6_rcv, 1142 .err_handler = ipip6_err, 1143 .priority = 1, 1144 }; 1145 1146 static void __net_exit sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1147 { 1148 int prio; 1149 1150 for (prio = 1; prio < 4; prio++) { 1151 int h; 1152 for (h = 0; h < HASH_SIZE; h++) { 1153 struct ip_tunnel *t = sitn->tunnels[prio][h]; 1154 1155 while (t != NULL) { 1156 unregister_netdevice_queue(t->dev, head); 1157 t = t->next; 1158 } 1159 } 1160 } 1161 } 1162 1163 static int __net_init sit_init_net(struct net *net) 1164 { 1165 struct sit_net *sitn = net_generic(net, sit_net_id); 1166 int err; 1167 1168 sitn->tunnels[0] = sitn->tunnels_wc; 1169 sitn->tunnels[1] = sitn->tunnels_l; 1170 sitn->tunnels[2] = sitn->tunnels_r; 1171 sitn->tunnels[3] = sitn->tunnels_r_l; 1172 1173 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1174 ipip6_tunnel_setup); 1175 if (!sitn->fb_tunnel_dev) { 1176 err = -ENOMEM; 1177 goto err_alloc_dev; 1178 } 1179 dev_net_set(sitn->fb_tunnel_dev, net); 1180 1181 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1182 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1183 1184 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1185 goto err_reg_dev; 1186 1187 return 0; 1188 1189 err_reg_dev: 1190 dev_put(sitn->fb_tunnel_dev); 1191 free_netdev(sitn->fb_tunnel_dev); 1192 err_alloc_dev: 1193 return err; 1194 } 1195 1196 static void __net_exit sit_exit_net(struct net *net) 1197 { 1198 struct sit_net *sitn = net_generic(net, sit_net_id); 1199 LIST_HEAD(list); 1200 1201 rtnl_lock(); 1202 sit_destroy_tunnels(sitn, &list); 1203 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1204 unregister_netdevice_many(&list); 1205 rtnl_unlock(); 1206 } 1207 1208 static struct pernet_operations sit_net_ops = { 1209 .init = sit_init_net, 1210 .exit = sit_exit_net, 1211 .id = &sit_net_id, 1212 .size = sizeof(struct sit_net), 1213 }; 1214 1215 static void __exit sit_cleanup(void) 1216 { 1217 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1218 1219 unregister_pernet_device(&sit_net_ops); 1220 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1221 } 1222 1223 static int __init sit_init(void) 1224 { 1225 int err; 1226 1227 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1228 1229 err = register_pernet_device(&sit_net_ops); 1230 if (err < 0) 1231 return err; 1232 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1233 if (err < 0) { 1234 unregister_pernet_device(&sit_net_ops); 1235 printk(KERN_INFO "sit init: Can't add protocol\n"); 1236 } 1237 return err; 1238 } 1239 1240 module_init(sit_init); 1241 module_exit(sit_cleanup); 1242 MODULE_LICENSE("GPL"); 1243 MODULE_ALIAS("sit0"); 1244