1 /* 2 * IPv6 over IPv4 tunnel device - Simple Internet Transition (SIT) 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Pedro Roque <roque@di.fc.ul.pt> 7 * Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License 11 * as published by the Free Software Foundation; either version 12 * 2 of the License, or (at your option) any later version. 13 * 14 * Changes: 15 * Roger Venning <r.venning@telstra.com>: 6to4 support 16 * Nate Thompson <nate@thebog.net>: 6to4 support 17 * Fred Templin <fred.l.templin@boeing.com>: isatap support 18 */ 19 20 #include <linux/module.h> 21 #include <linux/capability.h> 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/socket.h> 25 #include <linux/sockios.h> 26 #include <linux/net.h> 27 #include <linux/in6.h> 28 #include <linux/netdevice.h> 29 #include <linux/if_arp.h> 30 #include <linux/icmp.h> 31 #include <asm/uaccess.h> 32 #include <linux/init.h> 33 #include <linux/netfilter_ipv4.h> 34 #include <linux/if_ether.h> 35 36 #include <net/sock.h> 37 #include <net/snmp.h> 38 39 #include <net/ipv6.h> 40 #include <net/protocol.h> 41 #include <net/transp_v6.h> 42 #include <net/ip6_fib.h> 43 #include <net/ip6_route.h> 44 #include <net/ndisc.h> 45 #include <net/addrconf.h> 46 #include <net/ip.h> 47 #include <net/udp.h> 48 #include <net/icmp.h> 49 #include <net/ipip.h> 50 #include <net/inet_ecn.h> 51 #include <net/xfrm.h> 52 #include <net/dsfield.h> 53 #include <net/net_namespace.h> 54 #include <net/netns/generic.h> 55 56 /* 57 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 58 59 For comments look at net/ipv4/ip_gre.c --ANK 60 */ 61 62 #define HASH_SIZE 16 63 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 64 65 static void ipip6_fb_tunnel_init(struct net_device *dev); 66 static void ipip6_tunnel_init(struct net_device *dev); 67 static void ipip6_tunnel_setup(struct net_device *dev); 68 69 static int sit_net_id __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 INIT_RCU_HEAD(&p->rcu_head); 368 p->next = t->prl; 369 p->addr = a->addr; 370 p->flags = a->flags; 371 t->prl_count++; 372 rcu_assign_pointer(t->prl, p); 373 out: 374 spin_unlock(&ipip6_prl_lock); 375 return err; 376 } 377 378 static void prl_entry_destroy_rcu(struct rcu_head *head) 379 { 380 kfree(container_of(head, struct ip_tunnel_prl_entry, rcu_head)); 381 } 382 383 static void prl_list_destroy_rcu(struct rcu_head *head) 384 { 385 struct ip_tunnel_prl_entry *p, *n; 386 387 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 388 do { 389 n = p->next; 390 kfree(p); 391 p = n; 392 } while (p); 393 } 394 395 static int 396 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 397 { 398 struct ip_tunnel_prl_entry *x, **p; 399 int err = 0; 400 401 spin_lock(&ipip6_prl_lock); 402 403 if (a && a->addr != htonl(INADDR_ANY)) { 404 for (p = &t->prl; *p; p = &(*p)->next) { 405 if ((*p)->addr == a->addr) { 406 x = *p; 407 *p = x->next; 408 call_rcu(&x->rcu_head, prl_entry_destroy_rcu); 409 t->prl_count--; 410 goto out; 411 } 412 } 413 err = -ENXIO; 414 } else { 415 if (t->prl) { 416 t->prl_count = 0; 417 x = t->prl; 418 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 419 t->prl = NULL; 420 } 421 } 422 out: 423 spin_unlock(&ipip6_prl_lock); 424 return err; 425 } 426 427 static int 428 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 429 { 430 struct ip_tunnel_prl_entry *p; 431 int ok = 1; 432 433 rcu_read_lock(); 434 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 435 if (p) { 436 if (p->flags & PRL_DEFAULT) 437 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 438 else 439 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 440 } else { 441 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 442 if (ipv6_addr_is_isatap(addr6) && 443 (addr6->s6_addr32[3] == iph->saddr) && 444 ipv6_chk_prefix(addr6, t->dev)) 445 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 446 else 447 ok = 0; 448 } 449 rcu_read_unlock(); 450 return ok; 451 } 452 453 static void ipip6_tunnel_uninit(struct net_device *dev) 454 { 455 struct net *net = dev_net(dev); 456 struct sit_net *sitn = net_generic(net, sit_net_id); 457 458 if (dev == sitn->fb_tunnel_dev) { 459 spin_lock_bh(&ipip6_lock); 460 sitn->tunnels_wc[0] = NULL; 461 spin_unlock_bh(&ipip6_lock); 462 dev_put(dev); 463 } else { 464 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 465 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 466 dev_put(dev); 467 } 468 } 469 470 471 static int ipip6_err(struct sk_buff *skb, u32 info) 472 { 473 474 /* All the routers (except for Linux) return only 475 8 bytes of packet payload. It means, that precise relaying of 476 ICMP in the real Internet is absolutely infeasible. 477 */ 478 struct iphdr *iph = (struct iphdr*)skb->data; 479 const int type = icmp_hdr(skb)->type; 480 const int code = icmp_hdr(skb)->code; 481 struct ip_tunnel *t; 482 int err; 483 484 switch (type) { 485 default: 486 case ICMP_PARAMETERPROB: 487 return 0; 488 489 case ICMP_DEST_UNREACH: 490 switch (code) { 491 case ICMP_SR_FAILED: 492 case ICMP_PORT_UNREACH: 493 /* Impossible event. */ 494 return 0; 495 case ICMP_FRAG_NEEDED: 496 /* Soft state for pmtu is maintained by IP core. */ 497 return 0; 498 default: 499 /* All others are translated to HOST_UNREACH. 500 rfc2003 contains "deep thoughts" about NET_UNREACH, 501 I believe they are just ether pollution. --ANK 502 */ 503 break; 504 } 505 break; 506 case ICMP_TIME_EXCEEDED: 507 if (code != ICMP_EXC_TTL) 508 return 0; 509 break; 510 } 511 512 err = -ENOENT; 513 514 rcu_read_lock(); 515 t = ipip6_tunnel_lookup(dev_net(skb->dev), 516 skb->dev, 517 iph->daddr, 518 iph->saddr); 519 if (t == NULL || t->parms.iph.daddr == 0) 520 goto out; 521 522 err = 0; 523 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 524 goto out; 525 526 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 527 t->err_count++; 528 else 529 t->err_count = 1; 530 t->err_time = jiffies; 531 out: 532 rcu_read_unlock(); 533 return err; 534 } 535 536 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 537 { 538 if (INET_ECN_is_ce(iph->tos)) 539 IP6_ECN_set_ce(ipv6_hdr(skb)); 540 } 541 542 static int ipip6_rcv(struct sk_buff *skb) 543 { 544 struct iphdr *iph; 545 struct ip_tunnel *tunnel; 546 547 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 548 goto out; 549 550 iph = ip_hdr(skb); 551 552 rcu_read_lock(); 553 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 554 iph->saddr, iph->daddr); 555 if (tunnel != NULL) { 556 secpath_reset(skb); 557 skb->mac_header = skb->network_header; 558 skb_reset_network_header(skb); 559 IPCB(skb)->flags = 0; 560 skb->protocol = htons(ETH_P_IPV6); 561 skb->pkt_type = PACKET_HOST; 562 563 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 564 !isatap_chksrc(skb, iph, tunnel)) { 565 tunnel->dev->stats.rx_errors++; 566 rcu_read_unlock(); 567 kfree_skb(skb); 568 return 0; 569 } 570 tunnel->dev->stats.rx_packets++; 571 tunnel->dev->stats.rx_bytes += skb->len; 572 skb->dev = tunnel->dev; 573 skb_dst_drop(skb); 574 nf_reset(skb); 575 ipip6_ecn_decapsulate(iph, skb); 576 netif_rx(skb); 577 rcu_read_unlock(); 578 return 0; 579 } 580 581 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 582 rcu_read_unlock(); 583 out: 584 kfree_skb(skb); 585 return 0; 586 } 587 588 /* 589 * Returns the embedded IPv4 address if the IPv6 address 590 * comes from 6rd / 6to4 (RFC 3056) addr space. 591 */ 592 static inline 593 __be32 try_6rd(struct in6_addr *v6dst, struct ip_tunnel *tunnel) 594 { 595 __be32 dst = 0; 596 597 #ifdef CONFIG_IPV6_SIT_6RD 598 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 599 tunnel->ip6rd.prefixlen)) { 600 unsigned pbw0, pbi0; 601 int pbi1; 602 u32 d; 603 604 pbw0 = tunnel->ip6rd.prefixlen >> 5; 605 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 606 607 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 608 tunnel->ip6rd.relay_prefixlen; 609 610 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 611 if (pbi1 > 0) 612 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 613 (32 - pbi1); 614 615 dst = tunnel->ip6rd.relay_prefix | htonl(d); 616 } 617 #else 618 if (v6dst->s6_addr16[0] == htons(0x2002)) { 619 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 620 memcpy(&dst, &v6dst->s6_addr16[1], 4); 621 } 622 #endif 623 return dst; 624 } 625 626 /* 627 * This function assumes it is being called from dev_queue_xmit() 628 * and that skb is filled properly by that function. 629 */ 630 631 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 632 struct net_device *dev) 633 { 634 struct ip_tunnel *tunnel = netdev_priv(dev); 635 struct net_device_stats *stats = &dev->stats; 636 struct netdev_queue *txq = netdev_get_tx_queue(dev, 0); 637 struct iphdr *tiph = &tunnel->parms.iph; 638 struct ipv6hdr *iph6 = ipv6_hdr(skb); 639 u8 tos = tunnel->parms.iph.tos; 640 __be16 df = tiph->frag_off; 641 struct rtable *rt; /* Route to the other host */ 642 struct net_device *tdev; /* Device to other host */ 643 struct iphdr *iph; /* Our new IP header */ 644 unsigned int max_headroom; /* The extra header space needed */ 645 __be32 dst = tiph->daddr; 646 int mtu; 647 struct in6_addr *addr6; 648 int addr_type; 649 650 if (skb->protocol != htons(ETH_P_IPV6)) 651 goto tx_error; 652 653 /* ISATAP (RFC4214) - must come before 6to4 */ 654 if (dev->priv_flags & IFF_ISATAP) { 655 struct neighbour *neigh = NULL; 656 657 if (skb_dst(skb)) 658 neigh = skb_dst(skb)->neighbour; 659 660 if (neigh == NULL) { 661 if (net_ratelimit()) 662 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 663 goto tx_error; 664 } 665 666 addr6 = (struct in6_addr*)&neigh->primary_key; 667 addr_type = ipv6_addr_type(addr6); 668 669 if ((addr_type & IPV6_ADDR_UNICAST) && 670 ipv6_addr_is_isatap(addr6)) 671 dst = addr6->s6_addr32[3]; 672 else 673 goto tx_error; 674 } 675 676 if (!dst) 677 dst = try_6rd(&iph6->daddr, tunnel); 678 679 if (!dst) { 680 struct neighbour *neigh = NULL; 681 682 if (skb_dst(skb)) 683 neigh = skb_dst(skb)->neighbour; 684 685 if (neigh == NULL) { 686 if (net_ratelimit()) 687 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 688 goto tx_error; 689 } 690 691 addr6 = (struct in6_addr*)&neigh->primary_key; 692 addr_type = ipv6_addr_type(addr6); 693 694 if (addr_type == IPV6_ADDR_ANY) { 695 addr6 = &ipv6_hdr(skb)->daddr; 696 addr_type = ipv6_addr_type(addr6); 697 } 698 699 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 700 goto tx_error_icmp; 701 702 dst = addr6->s6_addr32[3]; 703 } 704 705 { 706 struct flowi fl = { .nl_u = { .ip4_u = 707 { .daddr = dst, 708 .saddr = tiph->saddr, 709 .tos = RT_TOS(tos) } }, 710 .oif = tunnel->parms.link, 711 .proto = IPPROTO_IPV6 }; 712 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 713 stats->tx_carrier_errors++; 714 goto tx_error_icmp; 715 } 716 } 717 if (rt->rt_type != RTN_UNICAST) { 718 ip_rt_put(rt); 719 stats->tx_carrier_errors++; 720 goto tx_error_icmp; 721 } 722 tdev = rt->u.dst.dev; 723 724 if (tdev == dev) { 725 ip_rt_put(rt); 726 stats->collisions++; 727 goto tx_error; 728 } 729 730 if (df) { 731 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 732 733 if (mtu < 68) { 734 stats->collisions++; 735 ip_rt_put(rt); 736 goto tx_error; 737 } 738 739 if (mtu < IPV6_MIN_MTU) { 740 mtu = IPV6_MIN_MTU; 741 df = 0; 742 } 743 744 if (tunnel->parms.iph.daddr && skb_dst(skb)) 745 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 746 747 if (skb->len > mtu) { 748 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 749 ip_rt_put(rt); 750 goto tx_error; 751 } 752 } 753 754 if (tunnel->err_count > 0) { 755 if (time_before(jiffies, 756 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 757 tunnel->err_count--; 758 dst_link_failure(skb); 759 } else 760 tunnel->err_count = 0; 761 } 762 763 /* 764 * Okay, now see if we can stuff it in the buffer as-is. 765 */ 766 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 767 768 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 769 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 770 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 771 if (!new_skb) { 772 ip_rt_put(rt); 773 txq->tx_dropped++; 774 dev_kfree_skb(skb); 775 return NETDEV_TX_OK; 776 } 777 if (skb->sk) 778 skb_set_owner_w(new_skb, skb->sk); 779 dev_kfree_skb(skb); 780 skb = new_skb; 781 iph6 = ipv6_hdr(skb); 782 } 783 784 skb->transport_header = skb->network_header; 785 skb_push(skb, sizeof(struct iphdr)); 786 skb_reset_network_header(skb); 787 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 788 IPCB(skb)->flags = 0; 789 skb_dst_drop(skb); 790 skb_dst_set(skb, &rt->u.dst); 791 792 /* 793 * Push down and install the IPIP header. 794 */ 795 796 iph = ip_hdr(skb); 797 iph->version = 4; 798 iph->ihl = sizeof(struct iphdr)>>2; 799 iph->frag_off = df; 800 iph->protocol = IPPROTO_IPV6; 801 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 802 iph->daddr = rt->rt_dst; 803 iph->saddr = rt->rt_src; 804 805 if ((iph->ttl = tiph->ttl) == 0) 806 iph->ttl = iph6->hop_limit; 807 808 nf_reset(skb); 809 810 IPTUNNEL_XMIT(); 811 return NETDEV_TX_OK; 812 813 tx_error_icmp: 814 dst_link_failure(skb); 815 tx_error: 816 stats->tx_errors++; 817 dev_kfree_skb(skb); 818 return NETDEV_TX_OK; 819 } 820 821 static void ipip6_tunnel_bind_dev(struct net_device *dev) 822 { 823 struct net_device *tdev = NULL; 824 struct ip_tunnel *tunnel; 825 struct iphdr *iph; 826 827 tunnel = netdev_priv(dev); 828 iph = &tunnel->parms.iph; 829 830 if (iph->daddr) { 831 struct flowi fl = { .nl_u = { .ip4_u = 832 { .daddr = iph->daddr, 833 .saddr = iph->saddr, 834 .tos = RT_TOS(iph->tos) } }, 835 .oif = tunnel->parms.link, 836 .proto = IPPROTO_IPV6 }; 837 struct rtable *rt; 838 if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { 839 tdev = rt->u.dst.dev; 840 ip_rt_put(rt); 841 } 842 dev->flags |= IFF_POINTOPOINT; 843 } 844 845 if (!tdev && tunnel->parms.link) 846 tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link); 847 848 if (tdev) { 849 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 850 dev->mtu = tdev->mtu - sizeof(struct iphdr); 851 if (dev->mtu < IPV6_MIN_MTU) 852 dev->mtu = IPV6_MIN_MTU; 853 } 854 dev->iflink = tunnel->parms.link; 855 } 856 857 static int 858 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 859 { 860 int err = 0; 861 struct ip_tunnel_parm p; 862 struct ip_tunnel_prl prl; 863 struct ip_tunnel *t; 864 struct net *net = dev_net(dev); 865 struct sit_net *sitn = net_generic(net, sit_net_id); 866 #ifdef CONFIG_IPV6_SIT_6RD 867 struct ip_tunnel_6rd ip6rd; 868 #endif 869 870 switch (cmd) { 871 case SIOCGETTUNNEL: 872 #ifdef CONFIG_IPV6_SIT_6RD 873 case SIOCGET6RD: 874 #endif 875 t = NULL; 876 if (dev == sitn->fb_tunnel_dev) { 877 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 878 err = -EFAULT; 879 break; 880 } 881 t = ipip6_tunnel_locate(net, &p, 0); 882 } 883 if (t == NULL) 884 t = netdev_priv(dev); 885 886 err = -EFAULT; 887 if (cmd == SIOCGETTUNNEL) { 888 memcpy(&p, &t->parms, sizeof(p)); 889 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 890 sizeof(p))) 891 goto done; 892 #ifdef CONFIG_IPV6_SIT_6RD 893 } else { 894 ipv6_addr_copy(&ip6rd.prefix, &t->ip6rd.prefix); 895 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 896 ip6rd.prefixlen = t->ip6rd.prefixlen; 897 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 898 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 899 sizeof(ip6rd))) 900 goto done; 901 #endif 902 } 903 err = 0; 904 break; 905 906 case SIOCADDTUNNEL: 907 case SIOCCHGTUNNEL: 908 err = -EPERM; 909 if (!capable(CAP_NET_ADMIN)) 910 goto done; 911 912 err = -EFAULT; 913 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 914 goto done; 915 916 err = -EINVAL; 917 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 918 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 919 goto done; 920 if (p.iph.ttl) 921 p.iph.frag_off |= htons(IP_DF); 922 923 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 924 925 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 926 if (t != NULL) { 927 if (t->dev != dev) { 928 err = -EEXIST; 929 break; 930 } 931 } else { 932 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 933 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 934 err = -EINVAL; 935 break; 936 } 937 t = netdev_priv(dev); 938 ipip6_tunnel_unlink(sitn, t); 939 t->parms.iph.saddr = p.iph.saddr; 940 t->parms.iph.daddr = p.iph.daddr; 941 memcpy(dev->dev_addr, &p.iph.saddr, 4); 942 memcpy(dev->broadcast, &p.iph.daddr, 4); 943 ipip6_tunnel_link(sitn, t); 944 netdev_state_change(dev); 945 } 946 } 947 948 if (t) { 949 err = 0; 950 if (cmd == SIOCCHGTUNNEL) { 951 t->parms.iph.ttl = p.iph.ttl; 952 t->parms.iph.tos = p.iph.tos; 953 if (t->parms.link != p.link) { 954 t->parms.link = p.link; 955 ipip6_tunnel_bind_dev(dev); 956 netdev_state_change(dev); 957 } 958 } 959 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 960 err = -EFAULT; 961 } else 962 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 963 break; 964 965 case SIOCDELTUNNEL: 966 err = -EPERM; 967 if (!capable(CAP_NET_ADMIN)) 968 goto done; 969 970 if (dev == sitn->fb_tunnel_dev) { 971 err = -EFAULT; 972 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 973 goto done; 974 err = -ENOENT; 975 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 976 goto done; 977 err = -EPERM; 978 if (t == netdev_priv(sitn->fb_tunnel_dev)) 979 goto done; 980 dev = t->dev; 981 } 982 unregister_netdevice(dev); 983 err = 0; 984 break; 985 986 case SIOCGETPRL: 987 err = -EINVAL; 988 if (dev == sitn->fb_tunnel_dev) 989 goto done; 990 err = -ENOENT; 991 if (!(t = netdev_priv(dev))) 992 goto done; 993 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 994 break; 995 996 case SIOCADDPRL: 997 case SIOCDELPRL: 998 case SIOCCHGPRL: 999 err = -EPERM; 1000 if (!capable(CAP_NET_ADMIN)) 1001 goto done; 1002 err = -EINVAL; 1003 if (dev == sitn->fb_tunnel_dev) 1004 goto done; 1005 err = -EFAULT; 1006 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1007 goto done; 1008 err = -ENOENT; 1009 if (!(t = netdev_priv(dev))) 1010 goto done; 1011 1012 switch (cmd) { 1013 case SIOCDELPRL: 1014 err = ipip6_tunnel_del_prl(t, &prl); 1015 break; 1016 case SIOCADDPRL: 1017 case SIOCCHGPRL: 1018 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1019 break; 1020 } 1021 netdev_state_change(dev); 1022 break; 1023 1024 #ifdef CONFIG_IPV6_SIT_6RD 1025 case SIOCADD6RD: 1026 case SIOCCHG6RD: 1027 case SIOCDEL6RD: 1028 err = -EPERM; 1029 if (!capable(CAP_NET_ADMIN)) 1030 goto done; 1031 1032 err = -EFAULT; 1033 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1034 sizeof(ip6rd))) 1035 goto done; 1036 1037 t = netdev_priv(dev); 1038 1039 if (cmd != SIOCDEL6RD) { 1040 struct in6_addr prefix; 1041 __be32 relay_prefix; 1042 1043 err = -EINVAL; 1044 if (ip6rd.relay_prefixlen > 32 || 1045 ip6rd.prefixlen + (32 - ip6rd.relay_prefixlen) > 64) 1046 goto done; 1047 1048 ipv6_addr_prefix(&prefix, &ip6rd.prefix, 1049 ip6rd.prefixlen); 1050 if (!ipv6_addr_equal(&prefix, &ip6rd.prefix)) 1051 goto done; 1052 if (ip6rd.relay_prefixlen) 1053 relay_prefix = ip6rd.relay_prefix & 1054 htonl(0xffffffffUL << 1055 (32 - ip6rd.relay_prefixlen)); 1056 else 1057 relay_prefix = 0; 1058 if (relay_prefix != ip6rd.relay_prefix) 1059 goto done; 1060 1061 ipv6_addr_copy(&t->ip6rd.prefix, &prefix); 1062 t->ip6rd.relay_prefix = relay_prefix; 1063 t->ip6rd.prefixlen = ip6rd.prefixlen; 1064 t->ip6rd.relay_prefixlen = ip6rd.relay_prefixlen; 1065 } else 1066 ipip6_tunnel_clone_6rd(dev, sitn); 1067 1068 err = 0; 1069 break; 1070 #endif 1071 1072 default: 1073 err = -EINVAL; 1074 } 1075 1076 done: 1077 return err; 1078 } 1079 1080 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1081 { 1082 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1083 return -EINVAL; 1084 dev->mtu = new_mtu; 1085 return 0; 1086 } 1087 1088 static const struct net_device_ops ipip6_netdev_ops = { 1089 .ndo_uninit = ipip6_tunnel_uninit, 1090 .ndo_start_xmit = ipip6_tunnel_xmit, 1091 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1092 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1093 }; 1094 1095 static void ipip6_tunnel_setup(struct net_device *dev) 1096 { 1097 dev->netdev_ops = &ipip6_netdev_ops; 1098 dev->destructor = free_netdev; 1099 1100 dev->type = ARPHRD_SIT; 1101 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1102 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1103 dev->flags = IFF_NOARP; 1104 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1105 dev->iflink = 0; 1106 dev->addr_len = 4; 1107 dev->features |= NETIF_F_NETNS_LOCAL; 1108 } 1109 1110 static void ipip6_tunnel_init(struct net_device *dev) 1111 { 1112 struct ip_tunnel *tunnel = netdev_priv(dev); 1113 1114 tunnel->dev = dev; 1115 strcpy(tunnel->parms.name, dev->name); 1116 1117 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1118 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1119 1120 ipip6_tunnel_bind_dev(dev); 1121 } 1122 1123 static void ipip6_fb_tunnel_init(struct net_device *dev) 1124 { 1125 struct ip_tunnel *tunnel = netdev_priv(dev); 1126 struct iphdr *iph = &tunnel->parms.iph; 1127 struct net *net = dev_net(dev); 1128 struct sit_net *sitn = net_generic(net, sit_net_id); 1129 1130 tunnel->dev = dev; 1131 strcpy(tunnel->parms.name, dev->name); 1132 1133 iph->version = 4; 1134 iph->protocol = IPPROTO_IPV6; 1135 iph->ihl = 5; 1136 iph->ttl = 64; 1137 1138 dev_hold(dev); 1139 sitn->tunnels_wc[0] = tunnel; 1140 } 1141 1142 static struct xfrm_tunnel sit_handler = { 1143 .handler = ipip6_rcv, 1144 .err_handler = ipip6_err, 1145 .priority = 1, 1146 }; 1147 1148 static void sit_destroy_tunnels(struct sit_net *sitn, struct list_head *head) 1149 { 1150 int prio; 1151 1152 for (prio = 1; prio < 4; prio++) { 1153 int h; 1154 for (h = 0; h < HASH_SIZE; h++) { 1155 struct ip_tunnel *t = sitn->tunnels[prio][h]; 1156 1157 while (t != NULL) { 1158 unregister_netdevice_queue(t->dev, head); 1159 t = t->next; 1160 } 1161 } 1162 } 1163 } 1164 1165 static int sit_init_net(struct net *net) 1166 { 1167 struct sit_net *sitn = net_generic(net, sit_net_id); 1168 int err; 1169 1170 sitn->tunnels[0] = sitn->tunnels_wc; 1171 sitn->tunnels[1] = sitn->tunnels_l; 1172 sitn->tunnels[2] = sitn->tunnels_r; 1173 sitn->tunnels[3] = sitn->tunnels_r_l; 1174 1175 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1176 ipip6_tunnel_setup); 1177 if (!sitn->fb_tunnel_dev) { 1178 err = -ENOMEM; 1179 goto err_alloc_dev; 1180 } 1181 dev_net_set(sitn->fb_tunnel_dev, net); 1182 1183 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1184 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1185 1186 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1187 goto err_reg_dev; 1188 1189 return 0; 1190 1191 err_reg_dev: 1192 dev_put(sitn->fb_tunnel_dev); 1193 free_netdev(sitn->fb_tunnel_dev); 1194 err_alloc_dev: 1195 return err; 1196 } 1197 1198 static void sit_exit_net(struct net *net) 1199 { 1200 struct sit_net *sitn = net_generic(net, sit_net_id); 1201 LIST_HEAD(list); 1202 1203 rtnl_lock(); 1204 sit_destroy_tunnels(sitn, &list); 1205 unregister_netdevice_queue(sitn->fb_tunnel_dev, &list); 1206 unregister_netdevice_many(&list); 1207 rtnl_unlock(); 1208 } 1209 1210 static struct pernet_operations sit_net_ops = { 1211 .init = sit_init_net, 1212 .exit = sit_exit_net, 1213 .id = &sit_net_id, 1214 .size = sizeof(struct sit_net), 1215 }; 1216 1217 static void __exit sit_cleanup(void) 1218 { 1219 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1220 1221 unregister_pernet_device(&sit_net_ops); 1222 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1223 } 1224 1225 static int __init sit_init(void) 1226 { 1227 int err; 1228 1229 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1230 1231 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) { 1232 printk(KERN_INFO "sit init: Can't add protocol\n"); 1233 return -EAGAIN; 1234 } 1235 1236 err = register_pernet_device(&sit_net_ops); 1237 if (err < 0) 1238 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1239 1240 return err; 1241 } 1242 1243 module_init(sit_init); 1244 module_exit(sit_cleanup); 1245 MODULE_LICENSE("GPL"); 1246 MODULE_ALIAS("sit0"); 1247