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 * $Id: sit.c,v 1.53 2001/09/25 05:09:53 davem Exp $ 10 * 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 * 16 * Changes: 17 * Roger Venning <r.venning@telstra.com>: 6to4 support 18 * Nate Thompson <nate@thebog.net>: 6to4 support 19 * Fred Templin <fred.l.templin@boeing.com>: isatap support 20 */ 21 22 #include <linux/module.h> 23 #include <linux/capability.h> 24 #include <linux/errno.h> 25 #include <linux/types.h> 26 #include <linux/socket.h> 27 #include <linux/sockios.h> 28 #include <linux/net.h> 29 #include <linux/in6.h> 30 #include <linux/netdevice.h> 31 #include <linux/if_arp.h> 32 #include <linux/icmp.h> 33 #include <asm/uaccess.h> 34 #include <linux/init.h> 35 #include <linux/netfilter_ipv4.h> 36 #include <linux/if_ether.h> 37 38 #include <net/sock.h> 39 #include <net/snmp.h> 40 41 #include <net/ipv6.h> 42 #include <net/protocol.h> 43 #include <net/transp_v6.h> 44 #include <net/ip6_fib.h> 45 #include <net/ip6_route.h> 46 #include <net/ndisc.h> 47 #include <net/addrconf.h> 48 #include <net/ip.h> 49 #include <net/udp.h> 50 #include <net/icmp.h> 51 #include <net/ipip.h> 52 #include <net/inet_ecn.h> 53 #include <net/xfrm.h> 54 #include <net/dsfield.h> 55 #include <net/net_namespace.h> 56 #include <net/netns/generic.h> 57 58 /* 59 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 60 61 For comments look at net/ipv4/ip_gre.c --ANK 62 */ 63 64 #define HASH_SIZE 16 65 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 66 67 static int ipip6_fb_tunnel_init(struct net_device *dev); 68 static int ipip6_tunnel_init(struct net_device *dev); 69 static void ipip6_tunnel_setup(struct net_device *dev); 70 71 static int sit_net_id; 72 struct sit_net { 73 struct ip_tunnel *tunnels_r_l[HASH_SIZE]; 74 struct ip_tunnel *tunnels_r[HASH_SIZE]; 75 struct ip_tunnel *tunnels_l[HASH_SIZE]; 76 struct ip_tunnel *tunnels_wc[1]; 77 struct ip_tunnel **tunnels[4]; 78 79 struct net_device *fb_tunnel_dev; 80 }; 81 82 static DEFINE_RWLOCK(ipip6_lock); 83 84 static struct ip_tunnel * ipip6_tunnel_lookup(struct net *net, 85 __be32 remote, __be32 local) 86 { 87 unsigned h0 = HASH(remote); 88 unsigned h1 = HASH(local); 89 struct ip_tunnel *t; 90 struct sit_net *sitn = net_generic(net, sit_net_id); 91 92 for (t = sitn->tunnels_r_l[h0^h1]; t; t = t->next) { 93 if (local == t->parms.iph.saddr && 94 remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 95 return t; 96 } 97 for (t = sitn->tunnels_r[h0]; t; t = t->next) { 98 if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP)) 99 return t; 100 } 101 for (t = sitn->tunnels_l[h1]; t; t = t->next) { 102 if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP)) 103 return t; 104 } 105 if ((t = sitn->tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP)) 106 return t; 107 return NULL; 108 } 109 110 static struct ip_tunnel **__ipip6_bucket(struct sit_net *sitn, 111 struct ip_tunnel_parm *parms) 112 { 113 __be32 remote = parms->iph.daddr; 114 __be32 local = parms->iph.saddr; 115 unsigned h = 0; 116 int prio = 0; 117 118 if (remote) { 119 prio |= 2; 120 h ^= HASH(remote); 121 } 122 if (local) { 123 prio |= 1; 124 h ^= HASH(local); 125 } 126 return &sitn->tunnels[prio][h]; 127 } 128 129 static inline struct ip_tunnel **ipip6_bucket(struct sit_net *sitn, 130 struct ip_tunnel *t) 131 { 132 return __ipip6_bucket(sitn, &t->parms); 133 } 134 135 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 136 { 137 struct ip_tunnel **tp; 138 139 for (tp = ipip6_bucket(sitn, t); *tp; tp = &(*tp)->next) { 140 if (t == *tp) { 141 write_lock_bh(&ipip6_lock); 142 *tp = t->next; 143 write_unlock_bh(&ipip6_lock); 144 break; 145 } 146 } 147 } 148 149 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 150 { 151 struct ip_tunnel **tp = ipip6_bucket(sitn, t); 152 153 t->next = *tp; 154 write_lock_bh(&ipip6_lock); 155 *tp = t; 156 write_unlock_bh(&ipip6_lock); 157 } 158 159 static struct ip_tunnel * ipip6_tunnel_locate(struct net *net, 160 struct ip_tunnel_parm *parms, int create) 161 { 162 __be32 remote = parms->iph.daddr; 163 __be32 local = parms->iph.saddr; 164 struct ip_tunnel *t, **tp, *nt; 165 struct net_device *dev; 166 char name[IFNAMSIZ]; 167 struct sit_net *sitn = net_generic(net, sit_net_id); 168 169 for (tp = __ipip6_bucket(sitn, parms); (t = *tp) != NULL; tp = &t->next) { 170 if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) 171 return t; 172 } 173 if (!create) 174 goto failed; 175 176 if (parms->name[0]) 177 strlcpy(name, parms->name, IFNAMSIZ); 178 else 179 sprintf(name, "sit%%d"); 180 181 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 182 if (dev == NULL) 183 return NULL; 184 185 dev_net_set(dev, net); 186 187 if (strchr(name, '%')) { 188 if (dev_alloc_name(dev, name) < 0) 189 goto failed_free; 190 } 191 192 nt = netdev_priv(dev); 193 dev->init = ipip6_tunnel_init; 194 nt->parms = *parms; 195 196 if (parms->i_flags & SIT_ISATAP) 197 dev->priv_flags |= IFF_ISATAP; 198 199 if (register_netdevice(dev) < 0) 200 goto failed_free; 201 202 dev_hold(dev); 203 204 ipip6_tunnel_link(sitn, nt); 205 return nt; 206 207 failed_free: 208 free_netdev(dev); 209 failed: 210 return NULL; 211 } 212 213 static struct ip_tunnel_prl_entry * 214 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 215 { 216 struct ip_tunnel_prl_entry *p = (struct ip_tunnel_prl_entry *)NULL; 217 218 for (p = t->prl; p; p = p->next) 219 if (p->addr == addr) 220 break; 221 return p; 222 223 } 224 225 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 226 { 227 struct ip_tunnel_prl *kp; 228 struct ip_tunnel_prl_entry *prl; 229 unsigned int cmax, c = 0, ca, len; 230 int ret = 0; 231 232 cmax = a->datalen / sizeof(*a); 233 if (cmax > 1 && a->addr != htonl(INADDR_ANY)) 234 cmax = 1; 235 236 /* For simple GET or for root users, 237 * we try harder to allocate. 238 */ 239 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 240 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 241 NULL; 242 243 read_lock(&ipip6_lock); 244 245 ca = t->prl_count < cmax ? t->prl_count : cmax; 246 247 if (!kp) { 248 /* We don't try hard to allocate much memory for 249 * non-root users. 250 * For root users, retry allocating enough memory for 251 * the answer. 252 */ 253 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 254 if (!kp) { 255 ret = -ENOMEM; 256 goto out; 257 } 258 } 259 260 c = 0; 261 for (prl = t->prl; prl; prl = prl->next) { 262 if (c > cmax) 263 break; 264 if (a->addr != htonl(INADDR_ANY) && prl->addr != a->addr) 265 continue; 266 kp[c].addr = prl->addr; 267 kp[c].flags = prl->flags; 268 c++; 269 if (a->addr != htonl(INADDR_ANY)) 270 break; 271 } 272 out: 273 read_unlock(&ipip6_lock); 274 275 len = sizeof(*kp) * c; 276 ret = len ? copy_to_user(a->data, kp, len) : 0; 277 278 kfree(kp); 279 if (ret) 280 return -EFAULT; 281 282 a->datalen = len; 283 return 0; 284 } 285 286 static int 287 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 288 { 289 struct ip_tunnel_prl_entry *p; 290 int err = 0; 291 292 if (a->addr == htonl(INADDR_ANY)) 293 return -EINVAL; 294 295 write_lock(&ipip6_lock); 296 297 for (p = t->prl; p; p = p->next) { 298 if (p->addr == a->addr) { 299 if (chg) 300 goto update; 301 err = -EEXIST; 302 goto out; 303 } 304 } 305 306 if (chg) { 307 err = -ENXIO; 308 goto out; 309 } 310 311 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 312 if (!p) { 313 err = -ENOBUFS; 314 goto out; 315 } 316 317 p->next = t->prl; 318 t->prl = p; 319 t->prl_count++; 320 update: 321 p->addr = a->addr; 322 p->flags = a->flags; 323 out: 324 write_unlock(&ipip6_lock); 325 return err; 326 } 327 328 static int 329 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 330 { 331 struct ip_tunnel_prl_entry *x, **p; 332 int err = 0; 333 334 write_lock(&ipip6_lock); 335 336 if (a && a->addr != htonl(INADDR_ANY)) { 337 for (p = &t->prl; *p; p = &(*p)->next) { 338 if ((*p)->addr == a->addr) { 339 x = *p; 340 *p = x->next; 341 kfree(x); 342 t->prl_count--; 343 goto out; 344 } 345 } 346 err = -ENXIO; 347 } else { 348 while (t->prl) { 349 x = t->prl; 350 t->prl = t->prl->next; 351 kfree(x); 352 t->prl_count--; 353 } 354 } 355 out: 356 write_unlock(&ipip6_lock); 357 return 0; 358 } 359 360 static int 361 isatap_chksrc(struct sk_buff *skb, struct iphdr *iph, struct ip_tunnel *t) 362 { 363 struct ip_tunnel_prl_entry *p; 364 int ok = 1; 365 366 read_lock(&ipip6_lock); 367 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 368 if (p) { 369 if (p->flags & PRL_DEFAULT) 370 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 371 else 372 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 373 } else { 374 struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 375 if (ipv6_addr_is_isatap(addr6) && 376 (addr6->s6_addr32[3] == iph->saddr) && 377 ipv6_chk_prefix(addr6, t->dev)) 378 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 379 else 380 ok = 0; 381 } 382 read_unlock(&ipip6_lock); 383 return ok; 384 } 385 386 static void ipip6_tunnel_uninit(struct net_device *dev) 387 { 388 struct net *net = dev_net(dev); 389 struct sit_net *sitn = net_generic(net, sit_net_id); 390 391 if (dev == sitn->fb_tunnel_dev) { 392 write_lock_bh(&ipip6_lock); 393 sitn->tunnels_wc[0] = NULL; 394 write_unlock_bh(&ipip6_lock); 395 dev_put(dev); 396 } else { 397 ipip6_tunnel_unlink(sitn, netdev_priv(dev)); 398 ipip6_tunnel_del_prl(netdev_priv(dev), NULL); 399 dev_put(dev); 400 } 401 } 402 403 404 static int ipip6_err(struct sk_buff *skb, u32 info) 405 { 406 #ifndef I_WISH_WORLD_WERE_PERFECT 407 408 /* It is not :-( All the routers (except for Linux) return only 409 8 bytes of packet payload. It means, that precise relaying of 410 ICMP in the real Internet is absolutely infeasible. 411 */ 412 struct iphdr *iph = (struct iphdr*)skb->data; 413 const int type = icmp_hdr(skb)->type; 414 const int code = icmp_hdr(skb)->code; 415 struct ip_tunnel *t; 416 int err; 417 418 switch (type) { 419 default: 420 case ICMP_PARAMETERPROB: 421 return 0; 422 423 case ICMP_DEST_UNREACH: 424 switch (code) { 425 case ICMP_SR_FAILED: 426 case ICMP_PORT_UNREACH: 427 /* Impossible event. */ 428 return 0; 429 case ICMP_FRAG_NEEDED: 430 /* Soft state for pmtu is maintained by IP core. */ 431 return 0; 432 default: 433 /* All others are translated to HOST_UNREACH. 434 rfc2003 contains "deep thoughts" about NET_UNREACH, 435 I believe they are just ether pollution. --ANK 436 */ 437 break; 438 } 439 break; 440 case ICMP_TIME_EXCEEDED: 441 if (code != ICMP_EXC_TTL) 442 return 0; 443 break; 444 } 445 446 err = -ENOENT; 447 448 read_lock(&ipip6_lock); 449 t = ipip6_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr); 450 if (t == NULL || t->parms.iph.daddr == 0) 451 goto out; 452 453 err = 0; 454 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 455 goto out; 456 457 if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) 458 t->err_count++; 459 else 460 t->err_count = 1; 461 t->err_time = jiffies; 462 out: 463 read_unlock(&ipip6_lock); 464 return err; 465 #else 466 struct iphdr *iph = (struct iphdr*)dp; 467 int hlen = iph->ihl<<2; 468 struct ipv6hdr *iph6; 469 const int type = icmp_hdr(skb)->type; 470 const int code = icmp_hdr(skb)->code; 471 int rel_type = 0; 472 int rel_code = 0; 473 int rel_info = 0; 474 struct sk_buff *skb2; 475 struct rt6_info *rt6i; 476 477 if (len < hlen + sizeof(struct ipv6hdr)) 478 return; 479 iph6 = (struct ipv6hdr*)(dp + hlen); 480 481 switch (type) { 482 default: 483 return; 484 case ICMP_PARAMETERPROB: 485 if (icmp_hdr(skb)->un.gateway < hlen) 486 return; 487 488 /* So... This guy found something strange INSIDE encapsulated 489 packet. Well, he is fool, but what can we do ? 490 */ 491 rel_type = ICMPV6_PARAMPROB; 492 rel_info = icmp_hdr(skb)->un.gateway - hlen; 493 break; 494 495 case ICMP_DEST_UNREACH: 496 switch (code) { 497 case ICMP_SR_FAILED: 498 case ICMP_PORT_UNREACH: 499 /* Impossible event. */ 500 return; 501 case ICMP_FRAG_NEEDED: 502 /* Too complicated case ... */ 503 return; 504 default: 505 /* All others are translated to HOST_UNREACH. 506 rfc2003 contains "deep thoughts" about NET_UNREACH, 507 I believe, it is just ether pollution. --ANK 508 */ 509 rel_type = ICMPV6_DEST_UNREACH; 510 rel_code = ICMPV6_ADDR_UNREACH; 511 break; 512 } 513 break; 514 case ICMP_TIME_EXCEEDED: 515 if (code != ICMP_EXC_TTL) 516 return; 517 rel_type = ICMPV6_TIME_EXCEED; 518 rel_code = ICMPV6_EXC_HOPLIMIT; 519 break; 520 } 521 522 /* Prepare fake skb to feed it to icmpv6_send */ 523 skb2 = skb_clone(skb, GFP_ATOMIC); 524 if (skb2 == NULL) 525 return 0; 526 dst_release(skb2->dst); 527 skb2->dst = NULL; 528 skb_pull(skb2, skb->data - (u8*)iph6); 529 skb_reset_network_header(skb2); 530 531 /* Try to guess incoming interface */ 532 rt6i = rt6_lookup(dev_net(skb->dev), &iph6->saddr, NULL, NULL, 0); 533 if (rt6i && rt6i->rt6i_dev) { 534 skb2->dev = rt6i->rt6i_dev; 535 536 rt6i = rt6_lookup(dev_net(skb->dev), 537 &iph6->daddr, &iph6->saddr, NULL, 0); 538 539 if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) { 540 struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev); 541 if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) { 542 rel_type = ICMPV6_DEST_UNREACH; 543 rel_code = ICMPV6_ADDR_UNREACH; 544 } 545 icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev); 546 } 547 } 548 kfree_skb(skb2); 549 return 0; 550 #endif 551 } 552 553 static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb) 554 { 555 if (INET_ECN_is_ce(iph->tos)) 556 IP6_ECN_set_ce(ipv6_hdr(skb)); 557 } 558 559 static int ipip6_rcv(struct sk_buff *skb) 560 { 561 struct iphdr *iph; 562 struct ip_tunnel *tunnel; 563 564 if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) 565 goto out; 566 567 iph = ip_hdr(skb); 568 569 read_lock(&ipip6_lock); 570 if ((tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), 571 iph->saddr, iph->daddr)) != NULL) { 572 secpath_reset(skb); 573 skb->mac_header = skb->network_header; 574 skb_reset_network_header(skb); 575 IPCB(skb)->flags = 0; 576 skb->protocol = htons(ETH_P_IPV6); 577 skb->pkt_type = PACKET_HOST; 578 579 if ((tunnel->dev->priv_flags & IFF_ISATAP) && 580 !isatap_chksrc(skb, iph, tunnel)) { 581 tunnel->stat.rx_errors++; 582 read_unlock(&ipip6_lock); 583 kfree_skb(skb); 584 return 0; 585 } 586 tunnel->stat.rx_packets++; 587 tunnel->stat.rx_bytes += skb->len; 588 skb->dev = tunnel->dev; 589 dst_release(skb->dst); 590 skb->dst = NULL; 591 nf_reset(skb); 592 ipip6_ecn_decapsulate(iph, skb); 593 netif_rx(skb); 594 read_unlock(&ipip6_lock); 595 return 0; 596 } 597 598 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); 599 kfree_skb(skb); 600 read_unlock(&ipip6_lock); 601 out: 602 return 0; 603 } 604 605 /* Returns the embedded IPv4 address if the IPv6 address 606 comes from 6to4 (RFC 3056) addr space */ 607 608 static inline __be32 try_6to4(struct in6_addr *v6dst) 609 { 610 __be32 dst = 0; 611 612 if (v6dst->s6_addr16[0] == htons(0x2002)) { 613 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 614 memcpy(&dst, &v6dst->s6_addr16[1], 4); 615 } 616 return dst; 617 } 618 619 /* 620 * This function assumes it is being called from dev_queue_xmit() 621 * and that skb is filled properly by that function. 622 */ 623 624 static int ipip6_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 625 { 626 struct ip_tunnel *tunnel = netdev_priv(dev); 627 struct net_device_stats *stats = &tunnel->stat; 628 struct iphdr *tiph = &tunnel->parms.iph; 629 struct ipv6hdr *iph6 = ipv6_hdr(skb); 630 u8 tos = tunnel->parms.iph.tos; 631 struct rtable *rt; /* Route to the other host */ 632 struct net_device *tdev; /* Device to other host */ 633 struct iphdr *iph; /* Our new IP header */ 634 unsigned int max_headroom; /* The extra header space needed */ 635 __be32 dst = tiph->daddr; 636 int mtu; 637 struct in6_addr *addr6; 638 int addr_type; 639 640 if (tunnel->recursion++) { 641 tunnel->stat.collisions++; 642 goto tx_error; 643 } 644 645 if (skb->protocol != htons(ETH_P_IPV6)) 646 goto tx_error; 647 648 /* ISATAP (RFC4214) - must come before 6to4 */ 649 if (dev->priv_flags & IFF_ISATAP) { 650 struct neighbour *neigh = NULL; 651 652 if (skb->dst) 653 neigh = skb->dst->neighbour; 654 655 if (neigh == NULL) { 656 if (net_ratelimit()) 657 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 658 goto tx_error; 659 } 660 661 addr6 = (struct in6_addr*)&neigh->primary_key; 662 addr_type = ipv6_addr_type(addr6); 663 664 if ((addr_type & IPV6_ADDR_UNICAST) && 665 ipv6_addr_is_isatap(addr6)) 666 dst = addr6->s6_addr32[3]; 667 else 668 goto tx_error; 669 } 670 671 if (!dst) 672 dst = try_6to4(&iph6->daddr); 673 674 if (!dst) { 675 struct neighbour *neigh = NULL; 676 677 if (skb->dst) 678 neigh = skb->dst->neighbour; 679 680 if (neigh == NULL) { 681 if (net_ratelimit()) 682 printk(KERN_DEBUG "sit: nexthop == NULL\n"); 683 goto tx_error; 684 } 685 686 addr6 = (struct in6_addr*)&neigh->primary_key; 687 addr_type = ipv6_addr_type(addr6); 688 689 if (addr_type == IPV6_ADDR_ANY) { 690 addr6 = &ipv6_hdr(skb)->daddr; 691 addr_type = ipv6_addr_type(addr6); 692 } 693 694 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 695 goto tx_error_icmp; 696 697 dst = addr6->s6_addr32[3]; 698 } 699 700 { 701 struct flowi fl = { .nl_u = { .ip4_u = 702 { .daddr = dst, 703 .saddr = tiph->saddr, 704 .tos = RT_TOS(tos) } }, 705 .oif = tunnel->parms.link, 706 .proto = IPPROTO_IPV6 }; 707 if (ip_route_output_key(dev_net(dev), &rt, &fl)) { 708 tunnel->stat.tx_carrier_errors++; 709 goto tx_error_icmp; 710 } 711 } 712 if (rt->rt_type != RTN_UNICAST) { 713 ip_rt_put(rt); 714 tunnel->stat.tx_carrier_errors++; 715 goto tx_error_icmp; 716 } 717 tdev = rt->u.dst.dev; 718 719 if (tdev == dev) { 720 ip_rt_put(rt); 721 tunnel->stat.collisions++; 722 goto tx_error; 723 } 724 725 if (tiph->frag_off) 726 mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr); 727 else 728 mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; 729 730 if (mtu < 68) { 731 tunnel->stat.collisions++; 732 ip_rt_put(rt); 733 goto tx_error; 734 } 735 if (mtu < IPV6_MIN_MTU) 736 mtu = IPV6_MIN_MTU; 737 if (tunnel->parms.iph.daddr && skb->dst) 738 skb->dst->ops->update_pmtu(skb->dst, mtu); 739 740 if (skb->len > mtu) { 741 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); 742 ip_rt_put(rt); 743 goto tx_error; 744 } 745 746 if (tunnel->err_count > 0) { 747 if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) { 748 tunnel->err_count--; 749 dst_link_failure(skb); 750 } else 751 tunnel->err_count = 0; 752 } 753 754 /* 755 * Okay, now see if we can stuff it in the buffer as-is. 756 */ 757 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 758 759 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 760 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 761 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 762 if (!new_skb) { 763 ip_rt_put(rt); 764 stats->tx_dropped++; 765 dev_kfree_skb(skb); 766 tunnel->recursion--; 767 return 0; 768 } 769 if (skb->sk) 770 skb_set_owner_w(new_skb, skb->sk); 771 dev_kfree_skb(skb); 772 skb = new_skb; 773 iph6 = ipv6_hdr(skb); 774 } 775 776 skb->transport_header = skb->network_header; 777 skb_push(skb, sizeof(struct iphdr)); 778 skb_reset_network_header(skb); 779 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 780 IPCB(skb)->flags = 0; 781 dst_release(skb->dst); 782 skb->dst = &rt->u.dst; 783 784 /* 785 * Push down and install the IPIP header. 786 */ 787 788 iph = ip_hdr(skb); 789 iph->version = 4; 790 iph->ihl = sizeof(struct iphdr)>>2; 791 if (mtu > IPV6_MIN_MTU) 792 iph->frag_off = htons(IP_DF); 793 else 794 iph->frag_off = 0; 795 796 iph->protocol = IPPROTO_IPV6; 797 iph->tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 798 iph->daddr = rt->rt_dst; 799 iph->saddr = rt->rt_src; 800 801 if ((iph->ttl = tiph->ttl) == 0) 802 iph->ttl = iph6->hop_limit; 803 804 nf_reset(skb); 805 806 IPTUNNEL_XMIT(); 807 tunnel->recursion--; 808 return 0; 809 810 tx_error_icmp: 811 dst_link_failure(skb); 812 tx_error: 813 stats->tx_errors++; 814 dev_kfree_skb(skb); 815 tunnel->recursion--; 816 return 0; 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); 864 865 switch (cmd) { 866 case SIOCGETTUNNEL: 867 t = NULL; 868 if (dev == sitn->fb_tunnel_dev) { 869 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 870 err = -EFAULT; 871 break; 872 } 873 t = ipip6_tunnel_locate(net, &p, 0); 874 } 875 if (t == NULL) 876 t = netdev_priv(dev); 877 memcpy(&p, &t->parms, sizeof(p)); 878 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 879 err = -EFAULT; 880 break; 881 882 case SIOCADDTUNNEL: 883 case SIOCCHGTUNNEL: 884 err = -EPERM; 885 if (!capable(CAP_NET_ADMIN)) 886 goto done; 887 888 err = -EFAULT; 889 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 890 goto done; 891 892 err = -EINVAL; 893 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPV6 || 894 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 895 goto done; 896 if (p.iph.ttl) 897 p.iph.frag_off |= htons(IP_DF); 898 899 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 900 901 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 902 if (t != NULL) { 903 if (t->dev != dev) { 904 err = -EEXIST; 905 break; 906 } 907 } else { 908 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 909 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 910 err = -EINVAL; 911 break; 912 } 913 t = netdev_priv(dev); 914 ipip6_tunnel_unlink(sitn, t); 915 t->parms.iph.saddr = p.iph.saddr; 916 t->parms.iph.daddr = p.iph.daddr; 917 memcpy(dev->dev_addr, &p.iph.saddr, 4); 918 memcpy(dev->broadcast, &p.iph.daddr, 4); 919 ipip6_tunnel_link(sitn, t); 920 netdev_state_change(dev); 921 } 922 } 923 924 if (t) { 925 err = 0; 926 if (cmd == SIOCCHGTUNNEL) { 927 t->parms.iph.ttl = p.iph.ttl; 928 t->parms.iph.tos = p.iph.tos; 929 if (t->parms.link != p.link) { 930 t->parms.link = p.link; 931 ipip6_tunnel_bind_dev(dev); 932 netdev_state_change(dev); 933 } 934 } 935 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 936 err = -EFAULT; 937 } else 938 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 939 break; 940 941 case SIOCDELTUNNEL: 942 err = -EPERM; 943 if (!capable(CAP_NET_ADMIN)) 944 goto done; 945 946 if (dev == sitn->fb_tunnel_dev) { 947 err = -EFAULT; 948 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 949 goto done; 950 err = -ENOENT; 951 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 952 goto done; 953 err = -EPERM; 954 if (t == netdev_priv(sitn->fb_tunnel_dev)) 955 goto done; 956 dev = t->dev; 957 } 958 unregister_netdevice(dev); 959 err = 0; 960 break; 961 962 case SIOCGETPRL: 963 case SIOCADDPRL: 964 case SIOCDELPRL: 965 case SIOCCHGPRL: 966 err = -EPERM; 967 if (cmd != SIOCGETPRL && !capable(CAP_NET_ADMIN)) 968 goto done; 969 err = -EINVAL; 970 if (dev == sitn->fb_tunnel_dev) 971 goto done; 972 err = -EFAULT; 973 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 974 goto done; 975 err = -ENOENT; 976 if (!(t = netdev_priv(dev))) 977 goto done; 978 979 switch (cmd) { 980 case SIOCGETPRL: 981 err = ipip6_tunnel_get_prl(t, &prl); 982 if (!err && copy_to_user(ifr->ifr_ifru.ifru_data, 983 &prl, sizeof(prl))) 984 err = -EFAULT; 985 break; 986 case SIOCDELPRL: 987 err = ipip6_tunnel_del_prl(t, &prl); 988 break; 989 case SIOCADDPRL: 990 case SIOCCHGPRL: 991 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 992 break; 993 } 994 if (cmd != SIOCGETPRL) 995 netdev_state_change(dev); 996 break; 997 998 default: 999 err = -EINVAL; 1000 } 1001 1002 done: 1003 return err; 1004 } 1005 1006 static struct net_device_stats *ipip6_tunnel_get_stats(struct net_device *dev) 1007 { 1008 return &(((struct ip_tunnel*)netdev_priv(dev))->stat); 1009 } 1010 1011 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1012 { 1013 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1014 return -EINVAL; 1015 dev->mtu = new_mtu; 1016 return 0; 1017 } 1018 1019 static void ipip6_tunnel_setup(struct net_device *dev) 1020 { 1021 dev->uninit = ipip6_tunnel_uninit; 1022 dev->destructor = free_netdev; 1023 dev->hard_start_xmit = ipip6_tunnel_xmit; 1024 dev->get_stats = ipip6_tunnel_get_stats; 1025 dev->do_ioctl = ipip6_tunnel_ioctl; 1026 dev->change_mtu = ipip6_tunnel_change_mtu; 1027 1028 dev->type = ARPHRD_SIT; 1029 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1030 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1031 dev->flags = IFF_NOARP; 1032 dev->iflink = 0; 1033 dev->addr_len = 4; 1034 dev->features |= NETIF_F_NETNS_LOCAL; 1035 } 1036 1037 static int ipip6_tunnel_init(struct net_device *dev) 1038 { 1039 struct ip_tunnel *tunnel; 1040 1041 tunnel = netdev_priv(dev); 1042 1043 tunnel->dev = dev; 1044 strcpy(tunnel->parms.name, dev->name); 1045 1046 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1047 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1048 1049 ipip6_tunnel_bind_dev(dev); 1050 1051 return 0; 1052 } 1053 1054 static int ipip6_fb_tunnel_init(struct net_device *dev) 1055 { 1056 struct ip_tunnel *tunnel = netdev_priv(dev); 1057 struct iphdr *iph = &tunnel->parms.iph; 1058 struct net *net = dev_net(dev); 1059 struct sit_net *sitn = net_generic(net, sit_net_id); 1060 1061 tunnel->dev = dev; 1062 strcpy(tunnel->parms.name, dev->name); 1063 1064 iph->version = 4; 1065 iph->protocol = IPPROTO_IPV6; 1066 iph->ihl = 5; 1067 iph->ttl = 64; 1068 1069 dev_hold(dev); 1070 sitn->tunnels_wc[0] = tunnel; 1071 return 0; 1072 } 1073 1074 static struct xfrm_tunnel sit_handler = { 1075 .handler = ipip6_rcv, 1076 .err_handler = ipip6_err, 1077 .priority = 1, 1078 }; 1079 1080 static void sit_destroy_tunnels(struct sit_net *sitn) 1081 { 1082 int prio; 1083 1084 for (prio = 1; prio < 4; prio++) { 1085 int h; 1086 for (h = 0; h < HASH_SIZE; h++) { 1087 struct ip_tunnel *t; 1088 while ((t = sitn->tunnels[prio][h]) != NULL) 1089 unregister_netdevice(t->dev); 1090 } 1091 } 1092 } 1093 1094 static int sit_init_net(struct net *net) 1095 { 1096 int err; 1097 struct sit_net *sitn; 1098 1099 err = -ENOMEM; 1100 sitn = kzalloc(sizeof(struct sit_net), GFP_KERNEL); 1101 if (sitn == NULL) 1102 goto err_alloc; 1103 1104 err = net_assign_generic(net, sit_net_id, sitn); 1105 if (err < 0) 1106 goto err_assign; 1107 1108 sitn->tunnels[0] = sitn->tunnels_wc; 1109 sitn->tunnels[1] = sitn->tunnels_l; 1110 sitn->tunnels[2] = sitn->tunnels_r; 1111 sitn->tunnels[3] = sitn->tunnels_r_l; 1112 1113 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1114 ipip6_tunnel_setup); 1115 if (!sitn->fb_tunnel_dev) { 1116 err = -ENOMEM; 1117 goto err_alloc_dev; 1118 } 1119 1120 sitn->fb_tunnel_dev->init = ipip6_fb_tunnel_init; 1121 dev_net_set(sitn->fb_tunnel_dev, net); 1122 1123 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1124 goto err_reg_dev; 1125 1126 return 0; 1127 1128 err_reg_dev: 1129 free_netdev(sitn->fb_tunnel_dev); 1130 err_alloc_dev: 1131 /* nothing */ 1132 err_assign: 1133 kfree(sitn); 1134 err_alloc: 1135 return err; 1136 } 1137 1138 static void sit_exit_net(struct net *net) 1139 { 1140 struct sit_net *sitn; 1141 1142 sitn = net_generic(net, sit_net_id); 1143 rtnl_lock(); 1144 sit_destroy_tunnels(sitn); 1145 unregister_netdevice(sitn->fb_tunnel_dev); 1146 rtnl_unlock(); 1147 kfree(sitn); 1148 } 1149 1150 static struct pernet_operations sit_net_ops = { 1151 .init = sit_init_net, 1152 .exit = sit_exit_net, 1153 }; 1154 1155 static void __exit sit_cleanup(void) 1156 { 1157 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1158 1159 unregister_pernet_gen_device(sit_net_id, &sit_net_ops); 1160 } 1161 1162 static int __init sit_init(void) 1163 { 1164 int err; 1165 1166 printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n"); 1167 1168 if (xfrm4_tunnel_register(&sit_handler, AF_INET6) < 0) { 1169 printk(KERN_INFO "sit init: Can't add protocol\n"); 1170 return -EAGAIN; 1171 } 1172 1173 err = register_pernet_gen_device(&sit_net_id, &sit_net_ops); 1174 if (err < 0) 1175 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1176 1177 return err; 1178 } 1179 1180 module_init(sit_init); 1181 module_exit(sit_cleanup); 1182 MODULE_LICENSE("GPL"); 1183 MODULE_ALIAS("sit0"); 1184