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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 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 <linux/slab.h> 34 #include <asm/uaccess.h> 35 #include <linux/init.h> 36 #include <linux/netfilter_ipv4.h> 37 #include <linux/if_ether.h> 38 39 #include <net/sock.h> 40 #include <net/snmp.h> 41 42 #include <net/ipv6.h> 43 #include <net/protocol.h> 44 #include <net/transp_v6.h> 45 #include <net/ip6_fib.h> 46 #include <net/ip6_route.h> 47 #include <net/ndisc.h> 48 #include <net/addrconf.h> 49 #include <net/ip.h> 50 #include <net/udp.h> 51 #include <net/icmp.h> 52 #include <net/ip_tunnels.h> 53 #include <net/inet_ecn.h> 54 #include <net/xfrm.h> 55 #include <net/dsfield.h> 56 #include <net/net_namespace.h> 57 #include <net/netns/generic.h> 58 59 /* 60 This version of net/ipv6/sit.c is cloned of net/ipv4/ip_gre.c 61 62 For comments look at net/ipv4/ip_gre.c --ANK 63 */ 64 65 #define HASH_SIZE 16 66 #define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF) 67 68 static bool log_ecn_error = true; 69 module_param(log_ecn_error, bool, 0644); 70 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 71 72 static int ipip6_tunnel_init(struct net_device *dev); 73 static void ipip6_tunnel_setup(struct net_device *dev); 74 static void ipip6_dev_free(struct net_device *dev); 75 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 76 __be32 *v4dst); 77 static struct rtnl_link_ops sit_link_ops __read_mostly; 78 79 static int sit_net_id __read_mostly; 80 struct sit_net { 81 struct ip_tunnel __rcu *tunnels_r_l[HASH_SIZE]; 82 struct ip_tunnel __rcu *tunnels_r[HASH_SIZE]; 83 struct ip_tunnel __rcu *tunnels_l[HASH_SIZE]; 84 struct ip_tunnel __rcu *tunnels_wc[1]; 85 struct ip_tunnel __rcu **tunnels[4]; 86 87 struct net_device *fb_tunnel_dev; 88 }; 89 90 /* 91 * Must be invoked with rcu_read_lock 92 */ 93 static struct ip_tunnel *ipip6_tunnel_lookup(struct net *net, 94 struct net_device *dev, __be32 remote, __be32 local) 95 { 96 unsigned int h0 = HASH(remote); 97 unsigned int h1 = HASH(local); 98 struct ip_tunnel *t; 99 struct sit_net *sitn = net_generic(net, sit_net_id); 100 101 for_each_ip_tunnel_rcu(t, sitn->tunnels_r_l[h0 ^ h1]) { 102 if (local == t->parms.iph.saddr && 103 remote == t->parms.iph.daddr && 104 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 105 (t->dev->flags & IFF_UP)) 106 return t; 107 } 108 for_each_ip_tunnel_rcu(t, sitn->tunnels_r[h0]) { 109 if (remote == t->parms.iph.daddr && 110 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 111 (t->dev->flags & IFF_UP)) 112 return t; 113 } 114 for_each_ip_tunnel_rcu(t, sitn->tunnels_l[h1]) { 115 if (local == t->parms.iph.saddr && 116 (!dev || !t->parms.link || dev->iflink == t->parms.link) && 117 (t->dev->flags & IFF_UP)) 118 return t; 119 } 120 t = rcu_dereference(sitn->tunnels_wc[0]); 121 if ((t != NULL) && (t->dev->flags & IFF_UP)) 122 return t; 123 return NULL; 124 } 125 126 static struct ip_tunnel __rcu **__ipip6_bucket(struct sit_net *sitn, 127 struct ip_tunnel_parm *parms) 128 { 129 __be32 remote = parms->iph.daddr; 130 __be32 local = parms->iph.saddr; 131 unsigned int h = 0; 132 int prio = 0; 133 134 if (remote) { 135 prio |= 2; 136 h ^= HASH(remote); 137 } 138 if (local) { 139 prio |= 1; 140 h ^= HASH(local); 141 } 142 return &sitn->tunnels[prio][h]; 143 } 144 145 static inline struct ip_tunnel __rcu **ipip6_bucket(struct sit_net *sitn, 146 struct ip_tunnel *t) 147 { 148 return __ipip6_bucket(sitn, &t->parms); 149 } 150 151 static void ipip6_tunnel_unlink(struct sit_net *sitn, struct ip_tunnel *t) 152 { 153 struct ip_tunnel __rcu **tp; 154 struct ip_tunnel *iter; 155 156 for (tp = ipip6_bucket(sitn, t); 157 (iter = rtnl_dereference(*tp)) != NULL; 158 tp = &iter->next) { 159 if (t == iter) { 160 rcu_assign_pointer(*tp, t->next); 161 break; 162 } 163 } 164 } 165 166 static void ipip6_tunnel_link(struct sit_net *sitn, struct ip_tunnel *t) 167 { 168 struct ip_tunnel __rcu **tp = ipip6_bucket(sitn, t); 169 170 rcu_assign_pointer(t->next, rtnl_dereference(*tp)); 171 rcu_assign_pointer(*tp, t); 172 } 173 174 static void ipip6_tunnel_clone_6rd(struct net_device *dev, struct sit_net *sitn) 175 { 176 #ifdef CONFIG_IPV6_SIT_6RD 177 struct ip_tunnel *t = netdev_priv(dev); 178 179 if (t->dev == sitn->fb_tunnel_dev) { 180 ipv6_addr_set(&t->ip6rd.prefix, htonl(0x20020000), 0, 0, 0); 181 t->ip6rd.relay_prefix = 0; 182 t->ip6rd.prefixlen = 16; 183 t->ip6rd.relay_prefixlen = 0; 184 } else { 185 struct ip_tunnel *t0 = netdev_priv(sitn->fb_tunnel_dev); 186 memcpy(&t->ip6rd, &t0->ip6rd, sizeof(t->ip6rd)); 187 } 188 #endif 189 } 190 191 static int ipip6_tunnel_create(struct net_device *dev) 192 { 193 struct ip_tunnel *t = netdev_priv(dev); 194 struct net *net = dev_net(dev); 195 struct sit_net *sitn = net_generic(net, sit_net_id); 196 int err; 197 198 err = ipip6_tunnel_init(dev); 199 if (err < 0) 200 goto out; 201 ipip6_tunnel_clone_6rd(dev, sitn); 202 203 if ((__force u16)t->parms.i_flags & SIT_ISATAP) 204 dev->priv_flags |= IFF_ISATAP; 205 206 err = register_netdevice(dev); 207 if (err < 0) 208 goto out; 209 210 strcpy(t->parms.name, dev->name); 211 dev->rtnl_link_ops = &sit_link_ops; 212 213 dev_hold(dev); 214 215 ipip6_tunnel_link(sitn, t); 216 return 0; 217 218 out: 219 return err; 220 } 221 222 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, 223 struct ip_tunnel_parm *parms, int create) 224 { 225 __be32 remote = parms->iph.daddr; 226 __be32 local = parms->iph.saddr; 227 struct ip_tunnel *t, *nt; 228 struct ip_tunnel __rcu **tp; 229 struct net_device *dev; 230 char name[IFNAMSIZ]; 231 struct sit_net *sitn = net_generic(net, sit_net_id); 232 233 for (tp = __ipip6_bucket(sitn, parms); 234 (t = rtnl_dereference(*tp)) != NULL; 235 tp = &t->next) { 236 if (local == t->parms.iph.saddr && 237 remote == t->parms.iph.daddr && 238 parms->link == t->parms.link) { 239 if (create) 240 return NULL; 241 else 242 return t; 243 } 244 } 245 if (!create) 246 goto failed; 247 248 if (parms->name[0]) 249 strlcpy(name, parms->name, IFNAMSIZ); 250 else 251 strcpy(name, "sit%d"); 252 253 dev = alloc_netdev(sizeof(*t), name, ipip6_tunnel_setup); 254 if (dev == NULL) 255 return NULL; 256 257 dev_net_set(dev, net); 258 259 nt = netdev_priv(dev); 260 261 nt->parms = *parms; 262 if (ipip6_tunnel_create(dev) < 0) 263 goto failed_free; 264 265 return nt; 266 267 failed_free: 268 ipip6_dev_free(dev); 269 failed: 270 return NULL; 271 } 272 273 #define for_each_prl_rcu(start) \ 274 for (prl = rcu_dereference(start); \ 275 prl; \ 276 prl = rcu_dereference(prl->next)) 277 278 static struct ip_tunnel_prl_entry * 279 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 280 { 281 struct ip_tunnel_prl_entry *prl; 282 283 for_each_prl_rcu(t->prl) 284 if (prl->addr == addr) 285 break; 286 return prl; 287 288 } 289 290 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 291 struct ip_tunnel_prl __user *a) 292 { 293 struct ip_tunnel_prl kprl, *kp; 294 struct ip_tunnel_prl_entry *prl; 295 unsigned int cmax, c = 0, ca, len; 296 int ret = 0; 297 298 if (copy_from_user(&kprl, a, sizeof(kprl))) 299 return -EFAULT; 300 cmax = kprl.datalen / sizeof(kprl); 301 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 302 cmax = 1; 303 304 /* For simple GET or for root users, 305 * we try harder to allocate. 306 */ 307 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 308 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 309 NULL; 310 311 rcu_read_lock(); 312 313 ca = t->prl_count < cmax ? t->prl_count : cmax; 314 315 if (!kp) { 316 /* We don't try hard to allocate much memory for 317 * non-root users. 318 * For root users, retry allocating enough memory for 319 * the answer. 320 */ 321 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 322 if (!kp) { 323 ret = -ENOMEM; 324 goto out; 325 } 326 } 327 328 c = 0; 329 for_each_prl_rcu(t->prl) { 330 if (c >= cmax) 331 break; 332 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 333 continue; 334 kp[c].addr = prl->addr; 335 kp[c].flags = prl->flags; 336 c++; 337 if (kprl.addr != htonl(INADDR_ANY)) 338 break; 339 } 340 out: 341 rcu_read_unlock(); 342 343 len = sizeof(*kp) * c; 344 ret = 0; 345 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 346 ret = -EFAULT; 347 348 kfree(kp); 349 350 return ret; 351 } 352 353 static int 354 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 355 { 356 struct ip_tunnel_prl_entry *p; 357 int err = 0; 358 359 if (a->addr == htonl(INADDR_ANY)) 360 return -EINVAL; 361 362 ASSERT_RTNL(); 363 364 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) { 365 if (p->addr == a->addr) { 366 if (chg) { 367 p->flags = a->flags; 368 goto out; 369 } 370 err = -EEXIST; 371 goto out; 372 } 373 } 374 375 if (chg) { 376 err = -ENXIO; 377 goto out; 378 } 379 380 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 381 if (!p) { 382 err = -ENOBUFS; 383 goto out; 384 } 385 386 p->next = t->prl; 387 p->addr = a->addr; 388 p->flags = a->flags; 389 t->prl_count++; 390 rcu_assign_pointer(t->prl, p); 391 out: 392 return err; 393 } 394 395 static void prl_list_destroy_rcu(struct rcu_head *head) 396 { 397 struct ip_tunnel_prl_entry *p, *n; 398 399 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 400 do { 401 n = rcu_dereference_protected(p->next, 1); 402 kfree(p); 403 p = n; 404 } while (p); 405 } 406 407 static int 408 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 409 { 410 struct ip_tunnel_prl_entry *x; 411 struct ip_tunnel_prl_entry __rcu **p; 412 int err = 0; 413 414 ASSERT_RTNL(); 415 416 if (a && a->addr != htonl(INADDR_ANY)) { 417 for (p = &t->prl; 418 (x = rtnl_dereference(*p)) != NULL; 419 p = &x->next) { 420 if (x->addr == a->addr) { 421 *p = x->next; 422 kfree_rcu(x, rcu_head); 423 t->prl_count--; 424 goto out; 425 } 426 } 427 err = -ENXIO; 428 } else { 429 x = rtnl_dereference(t->prl); 430 if (x) { 431 t->prl_count = 0; 432 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 433 t->prl = NULL; 434 } 435 } 436 out: 437 return err; 438 } 439 440 static int 441 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t) 442 { 443 struct ip_tunnel_prl_entry *p; 444 int ok = 1; 445 446 rcu_read_lock(); 447 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 448 if (p) { 449 if (p->flags & PRL_DEFAULT) 450 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 451 else 452 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 453 } else { 454 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 455 456 if (ipv6_addr_is_isatap(addr6) && 457 (addr6->s6_addr32[3] == iph->saddr) && 458 ipv6_chk_prefix(addr6, t->dev)) 459 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 460 else 461 ok = 0; 462 } 463 rcu_read_unlock(); 464 return ok; 465 } 466 467 static void ipip6_tunnel_uninit(struct net_device *dev) 468 { 469 struct ip_tunnel *tunnel = netdev_priv(dev); 470 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id); 471 472 if (dev == sitn->fb_tunnel_dev) { 473 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL); 474 } else { 475 ipip6_tunnel_unlink(sitn, tunnel); 476 ipip6_tunnel_del_prl(tunnel, NULL); 477 } 478 dev_put(dev); 479 } 480 481 482 static int ipip6_err(struct sk_buff *skb, u32 info) 483 { 484 485 /* All the routers (except for Linux) return only 486 8 bytes of packet payload. It means, that precise relaying of 487 ICMP in the real Internet is absolutely infeasible. 488 */ 489 const struct iphdr *iph = (const struct iphdr *)skb->data; 490 const int type = icmp_hdr(skb)->type; 491 const int code = icmp_hdr(skb)->code; 492 struct ip_tunnel *t; 493 int err; 494 495 switch (type) { 496 default: 497 case ICMP_PARAMETERPROB: 498 return 0; 499 500 case ICMP_DEST_UNREACH: 501 switch (code) { 502 case ICMP_SR_FAILED: 503 case ICMP_PORT_UNREACH: 504 /* Impossible event. */ 505 return 0; 506 default: 507 /* All others are translated to HOST_UNREACH. 508 rfc2003 contains "deep thoughts" about NET_UNREACH, 509 I believe they are just ether pollution. --ANK 510 */ 511 break; 512 } 513 break; 514 case ICMP_TIME_EXCEEDED: 515 if (code != ICMP_EXC_TTL) 516 return 0; 517 break; 518 case ICMP_REDIRECT: 519 break; 520 } 521 522 err = -ENOENT; 523 524 t = ipip6_tunnel_lookup(dev_net(skb->dev), 525 skb->dev, 526 iph->daddr, 527 iph->saddr); 528 if (t == NULL) 529 goto out; 530 531 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 532 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 533 t->dev->ifindex, 0, IPPROTO_IPV6, 0); 534 err = 0; 535 goto out; 536 } 537 if (type == ICMP_REDIRECT) { 538 ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0, 539 IPPROTO_IPV6, 0); 540 err = 0; 541 goto out; 542 } 543 544 if (t->parms.iph.daddr == 0) 545 goto out; 546 547 err = 0; 548 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 549 goto out; 550 551 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 552 t->err_count++; 553 else 554 t->err_count = 1; 555 t->err_time = jiffies; 556 out: 557 return err; 558 } 559 560 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, 561 const struct in6_addr *v6addr) 562 { 563 __be32 v4embed = 0; 564 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) 565 return true; 566 return false; 567 } 568 569 /* Checks if an address matches an address on the tunnel interface. 570 * Used to detect the NAT of proto 41 packets and let them pass spoofing test. 571 * Long story: 572 * This function is called after we considered the packet as spoofed 573 * in is_spoofed_6rd. 574 * We may have a router that is doing NAT for proto 41 packets 575 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb 576 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd 577 * function will return true, dropping the packet. 578 * But, we can still check if is spoofed against the IP 579 * addresses associated with the interface. 580 */ 581 static bool only_dnatted(const struct ip_tunnel *tunnel, 582 const struct in6_addr *v6dst) 583 { 584 int prefix_len; 585 586 #ifdef CONFIG_IPV6_SIT_6RD 587 prefix_len = tunnel->ip6rd.prefixlen + 32 588 - tunnel->ip6rd.relay_prefixlen; 589 #else 590 prefix_len = 48; 591 #endif 592 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev); 593 } 594 595 /* Returns true if a packet is spoofed */ 596 static bool packet_is_spoofed(struct sk_buff *skb, 597 const struct iphdr *iph, 598 struct ip_tunnel *tunnel) 599 { 600 const struct ipv6hdr *ipv6h; 601 602 if (tunnel->dev->priv_flags & IFF_ISATAP) { 603 if (!isatap_chksrc(skb, iph, tunnel)) 604 return true; 605 606 return false; 607 } 608 609 if (tunnel->dev->flags & IFF_POINTOPOINT) 610 return false; 611 612 ipv6h = ipv6_hdr(skb); 613 614 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) { 615 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 616 &iph->saddr, &ipv6h->saddr, 617 &iph->daddr, &ipv6h->daddr); 618 return true; 619 } 620 621 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr))) 622 return false; 623 624 if (only_dnatted(tunnel, &ipv6h->daddr)) 625 return false; 626 627 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 628 &iph->saddr, &ipv6h->saddr, 629 &iph->daddr, &ipv6h->daddr); 630 return true; 631 } 632 633 static int ipip6_rcv(struct sk_buff *skb) 634 { 635 const struct iphdr *iph = ip_hdr(skb); 636 struct ip_tunnel *tunnel; 637 int err; 638 639 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 640 iph->saddr, iph->daddr); 641 if (tunnel != NULL) { 642 struct pcpu_tstats *tstats; 643 644 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && 645 tunnel->parms.iph.protocol != 0) 646 goto out; 647 648 skb->mac_header = skb->network_header; 649 skb_reset_network_header(skb); 650 IPCB(skb)->flags = 0; 651 skb->protocol = htons(ETH_P_IPV6); 652 653 if (packet_is_spoofed(skb, iph, tunnel)) { 654 tunnel->dev->stats.rx_errors++; 655 goto out; 656 } 657 658 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net); 659 660 err = IP_ECN_decapsulate(iph, skb); 661 if (unlikely(err)) { 662 if (log_ecn_error) 663 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 664 &iph->saddr, iph->tos); 665 if (err > 1) { 666 ++tunnel->dev->stats.rx_frame_errors; 667 ++tunnel->dev->stats.rx_errors; 668 goto out; 669 } 670 } 671 672 tstats = this_cpu_ptr(tunnel->dev->tstats); 673 tstats->rx_packets++; 674 tstats->rx_bytes += skb->len; 675 676 netif_rx(skb); 677 678 return 0; 679 } 680 681 /* no tunnel matched, let upstream know, ipsec may handle it */ 682 return 1; 683 out: 684 kfree_skb(skb); 685 return 0; 686 } 687 688 static const struct tnl_ptk_info tpi = { 689 /* no tunnel info required for ipip. */ 690 .proto = htons(ETH_P_IP), 691 }; 692 693 static int ipip_rcv(struct sk_buff *skb) 694 { 695 const struct iphdr *iph; 696 struct ip_tunnel *tunnel; 697 698 iph = ip_hdr(skb); 699 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 700 iph->saddr, iph->daddr); 701 if (tunnel != NULL) { 702 if (tunnel->parms.iph.protocol != IPPROTO_IPIP && 703 tunnel->parms.iph.protocol != 0) 704 goto drop; 705 706 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 707 goto drop; 708 if (iptunnel_pull_header(skb, 0, tpi.proto)) 709 goto drop; 710 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); 711 } 712 713 return 1; 714 715 drop: 716 kfree_skb(skb); 717 return 0; 718 } 719 720 /* 721 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function 722 * stores the embedded IPv4 address in v4dst and returns true. 723 */ 724 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 725 __be32 *v4dst) 726 { 727 #ifdef CONFIG_IPV6_SIT_6RD 728 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 729 tunnel->ip6rd.prefixlen)) { 730 unsigned int pbw0, pbi0; 731 int pbi1; 732 u32 d; 733 734 pbw0 = tunnel->ip6rd.prefixlen >> 5; 735 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 736 737 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 738 tunnel->ip6rd.relay_prefixlen; 739 740 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 741 if (pbi1 > 0) 742 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 743 (32 - pbi1); 744 745 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); 746 return true; 747 } 748 #else 749 if (v6dst->s6_addr16[0] == htons(0x2002)) { 750 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 751 memcpy(v4dst, &v6dst->s6_addr16[1], 4); 752 return true; 753 } 754 #endif 755 return false; 756 } 757 758 static inline __be32 try_6rd(struct ip_tunnel *tunnel, 759 const struct in6_addr *v6dst) 760 { 761 __be32 dst = 0; 762 check_6rd(tunnel, v6dst, &dst); 763 return dst; 764 } 765 766 /* 767 * This function assumes it is being called from dev_queue_xmit() 768 * and that skb is filled properly by that function. 769 */ 770 771 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 772 struct net_device *dev) 773 { 774 struct ip_tunnel *tunnel = netdev_priv(dev); 775 const struct iphdr *tiph = &tunnel->parms.iph; 776 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 777 u8 tos = tunnel->parms.iph.tos; 778 __be16 df = tiph->frag_off; 779 struct rtable *rt; /* Route to the other host */ 780 struct net_device *tdev; /* Device to other host */ 781 unsigned int max_headroom; /* The extra header space needed */ 782 __be32 dst = tiph->daddr; 783 struct flowi4 fl4; 784 int mtu; 785 const struct in6_addr *addr6; 786 int addr_type; 787 u8 ttl; 788 int err; 789 790 if (skb->protocol != htons(ETH_P_IPV6)) 791 goto tx_error; 792 793 if (tos == 1) 794 tos = ipv6_get_dsfield(iph6); 795 796 /* ISATAP (RFC4214) - must come before 6to4 */ 797 if (dev->priv_flags & IFF_ISATAP) { 798 struct neighbour *neigh = NULL; 799 bool do_tx_error = false; 800 801 if (skb_dst(skb)) 802 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 803 804 if (neigh == NULL) { 805 net_dbg_ratelimited("nexthop == NULL\n"); 806 goto tx_error; 807 } 808 809 addr6 = (const struct in6_addr *)&neigh->primary_key; 810 addr_type = ipv6_addr_type(addr6); 811 812 if ((addr_type & IPV6_ADDR_UNICAST) && 813 ipv6_addr_is_isatap(addr6)) 814 dst = addr6->s6_addr32[3]; 815 else 816 do_tx_error = true; 817 818 neigh_release(neigh); 819 if (do_tx_error) 820 goto tx_error; 821 } 822 823 if (!dst) 824 dst = try_6rd(tunnel, &iph6->daddr); 825 826 if (!dst) { 827 struct neighbour *neigh = NULL; 828 bool do_tx_error = false; 829 830 if (skb_dst(skb)) 831 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 832 833 if (neigh == NULL) { 834 net_dbg_ratelimited("nexthop == NULL\n"); 835 goto tx_error; 836 } 837 838 addr6 = (const struct in6_addr *)&neigh->primary_key; 839 addr_type = ipv6_addr_type(addr6); 840 841 if (addr_type == IPV6_ADDR_ANY) { 842 addr6 = &ipv6_hdr(skb)->daddr; 843 addr_type = ipv6_addr_type(addr6); 844 } 845 846 if ((addr_type & IPV6_ADDR_COMPATv4) != 0) 847 dst = addr6->s6_addr32[3]; 848 else 849 do_tx_error = true; 850 851 neigh_release(neigh); 852 if (do_tx_error) 853 goto tx_error; 854 } 855 856 rt = ip_route_output_ports(tunnel->net, &fl4, NULL, 857 dst, tiph->saddr, 858 0, 0, 859 IPPROTO_IPV6, RT_TOS(tos), 860 tunnel->parms.link); 861 if (IS_ERR(rt)) { 862 dev->stats.tx_carrier_errors++; 863 goto tx_error_icmp; 864 } 865 if (rt->rt_type != RTN_UNICAST) { 866 ip_rt_put(rt); 867 dev->stats.tx_carrier_errors++; 868 goto tx_error_icmp; 869 } 870 tdev = rt->dst.dev; 871 872 if (tdev == dev) { 873 ip_rt_put(rt); 874 dev->stats.collisions++; 875 goto tx_error; 876 } 877 878 if (df) { 879 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 880 881 if (mtu < 68) { 882 dev->stats.collisions++; 883 ip_rt_put(rt); 884 goto tx_error; 885 } 886 887 if (mtu < IPV6_MIN_MTU) { 888 mtu = IPV6_MIN_MTU; 889 df = 0; 890 } 891 892 if (tunnel->parms.iph.daddr && skb_dst(skb)) 893 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 894 895 if (skb->len > mtu) { 896 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 897 ip_rt_put(rt); 898 goto tx_error; 899 } 900 } 901 902 if (tunnel->err_count > 0) { 903 if (time_before(jiffies, 904 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 905 tunnel->err_count--; 906 dst_link_failure(skb); 907 } else 908 tunnel->err_count = 0; 909 } 910 911 /* 912 * Okay, now see if we can stuff it in the buffer as-is. 913 */ 914 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 915 916 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 917 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 918 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 919 if (!new_skb) { 920 ip_rt_put(rt); 921 dev->stats.tx_dropped++; 922 dev_kfree_skb(skb); 923 return NETDEV_TX_OK; 924 } 925 if (skb->sk) 926 skb_set_owner_w(new_skb, skb->sk); 927 dev_kfree_skb(skb); 928 skb = new_skb; 929 iph6 = ipv6_hdr(skb); 930 } 931 ttl = tiph->ttl; 932 if (ttl == 0) 933 ttl = iph6->hop_limit; 934 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 935 936 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT); 937 if (IS_ERR(skb)) 938 goto out; 939 940 err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos, 941 ttl, df, !net_eq(tunnel->net, dev_net(dev))); 942 iptunnel_xmit_stats(err, &dev->stats, dev->tstats); 943 return NETDEV_TX_OK; 944 945 tx_error_icmp: 946 dst_link_failure(skb); 947 tx_error: 948 dev_kfree_skb(skb); 949 out: 950 dev->stats.tx_errors++; 951 return NETDEV_TX_OK; 952 } 953 954 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 955 { 956 struct ip_tunnel *tunnel = netdev_priv(dev); 957 const struct iphdr *tiph = &tunnel->parms.iph; 958 959 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP); 960 if (IS_ERR(skb)) 961 goto out; 962 963 ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP); 964 return NETDEV_TX_OK; 965 out: 966 dev->stats.tx_errors++; 967 return NETDEV_TX_OK; 968 } 969 970 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, 971 struct net_device *dev) 972 { 973 switch (skb->protocol) { 974 case htons(ETH_P_IP): 975 ipip_tunnel_xmit(skb, dev); 976 break; 977 case htons(ETH_P_IPV6): 978 ipip6_tunnel_xmit(skb, dev); 979 break; 980 default: 981 goto tx_err; 982 } 983 984 return NETDEV_TX_OK; 985 986 tx_err: 987 dev->stats.tx_errors++; 988 dev_kfree_skb(skb); 989 return NETDEV_TX_OK; 990 991 } 992 993 static void ipip6_tunnel_bind_dev(struct net_device *dev) 994 { 995 struct net_device *tdev = NULL; 996 struct ip_tunnel *tunnel; 997 const struct iphdr *iph; 998 struct flowi4 fl4; 999 1000 tunnel = netdev_priv(dev); 1001 iph = &tunnel->parms.iph; 1002 1003 if (iph->daddr) { 1004 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, 1005 NULL, 1006 iph->daddr, iph->saddr, 1007 0, 0, 1008 IPPROTO_IPV6, 1009 RT_TOS(iph->tos), 1010 tunnel->parms.link); 1011 1012 if (!IS_ERR(rt)) { 1013 tdev = rt->dst.dev; 1014 ip_rt_put(rt); 1015 } 1016 dev->flags |= IFF_POINTOPOINT; 1017 } 1018 1019 if (!tdev && tunnel->parms.link) 1020 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 1021 1022 if (tdev) { 1023 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 1024 dev->mtu = tdev->mtu - sizeof(struct iphdr); 1025 if (dev->mtu < IPV6_MIN_MTU) 1026 dev->mtu = IPV6_MIN_MTU; 1027 } 1028 dev->iflink = tunnel->parms.link; 1029 } 1030 1031 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p) 1032 { 1033 struct net *net = t->net; 1034 struct sit_net *sitn = net_generic(net, sit_net_id); 1035 1036 ipip6_tunnel_unlink(sitn, t); 1037 synchronize_net(); 1038 t->parms.iph.saddr = p->iph.saddr; 1039 t->parms.iph.daddr = p->iph.daddr; 1040 memcpy(t->dev->dev_addr, &p->iph.saddr, 4); 1041 memcpy(t->dev->broadcast, &p->iph.daddr, 4); 1042 ipip6_tunnel_link(sitn, t); 1043 t->parms.iph.ttl = p->iph.ttl; 1044 t->parms.iph.tos = p->iph.tos; 1045 if (t->parms.link != p->link) { 1046 t->parms.link = p->link; 1047 ipip6_tunnel_bind_dev(t->dev); 1048 } 1049 netdev_state_change(t->dev); 1050 } 1051 1052 #ifdef CONFIG_IPV6_SIT_6RD 1053 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, 1054 struct ip_tunnel_6rd *ip6rd) 1055 { 1056 struct in6_addr prefix; 1057 __be32 relay_prefix; 1058 1059 if (ip6rd->relay_prefixlen > 32 || 1060 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) 1061 return -EINVAL; 1062 1063 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); 1064 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) 1065 return -EINVAL; 1066 if (ip6rd->relay_prefixlen) 1067 relay_prefix = ip6rd->relay_prefix & 1068 htonl(0xffffffffUL << 1069 (32 - ip6rd->relay_prefixlen)); 1070 else 1071 relay_prefix = 0; 1072 if (relay_prefix != ip6rd->relay_prefix) 1073 return -EINVAL; 1074 1075 t->ip6rd.prefix = prefix; 1076 t->ip6rd.relay_prefix = relay_prefix; 1077 t->ip6rd.prefixlen = ip6rd->prefixlen; 1078 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; 1079 netdev_state_change(t->dev); 1080 return 0; 1081 } 1082 #endif 1083 1084 static int 1085 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 1086 { 1087 int err = 0; 1088 struct ip_tunnel_parm p; 1089 struct ip_tunnel_prl prl; 1090 struct ip_tunnel *t; 1091 struct net *net = dev_net(dev); 1092 struct sit_net *sitn = net_generic(net, sit_net_id); 1093 #ifdef CONFIG_IPV6_SIT_6RD 1094 struct ip_tunnel_6rd ip6rd; 1095 #endif 1096 1097 switch (cmd) { 1098 case SIOCGETTUNNEL: 1099 #ifdef CONFIG_IPV6_SIT_6RD 1100 case SIOCGET6RD: 1101 #endif 1102 t = NULL; 1103 if (dev == sitn->fb_tunnel_dev) { 1104 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 1105 err = -EFAULT; 1106 break; 1107 } 1108 t = ipip6_tunnel_locate(net, &p, 0); 1109 } 1110 if (t == NULL) 1111 t = netdev_priv(dev); 1112 1113 err = -EFAULT; 1114 if (cmd == SIOCGETTUNNEL) { 1115 memcpy(&p, &t->parms, sizeof(p)); 1116 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 1117 sizeof(p))) 1118 goto done; 1119 #ifdef CONFIG_IPV6_SIT_6RD 1120 } else { 1121 ip6rd.prefix = t->ip6rd.prefix; 1122 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 1123 ip6rd.prefixlen = t->ip6rd.prefixlen; 1124 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 1125 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 1126 sizeof(ip6rd))) 1127 goto done; 1128 #endif 1129 } 1130 err = 0; 1131 break; 1132 1133 case SIOCADDTUNNEL: 1134 case SIOCCHGTUNNEL: 1135 err = -EPERM; 1136 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1137 goto done; 1138 1139 err = -EFAULT; 1140 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1141 goto done; 1142 1143 err = -EINVAL; 1144 if (p.iph.protocol != IPPROTO_IPV6 && 1145 p.iph.protocol != IPPROTO_IPIP && 1146 p.iph.protocol != 0) 1147 goto done; 1148 if (p.iph.version != 4 || 1149 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 1150 goto done; 1151 if (p.iph.ttl) 1152 p.iph.frag_off |= htons(IP_DF); 1153 1154 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 1155 1156 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 1157 if (t != NULL) { 1158 if (t->dev != dev) { 1159 err = -EEXIST; 1160 break; 1161 } 1162 } else { 1163 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 1164 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 1165 err = -EINVAL; 1166 break; 1167 } 1168 t = netdev_priv(dev); 1169 } 1170 1171 ipip6_tunnel_update(t, &p); 1172 } 1173 1174 if (t) { 1175 err = 0; 1176 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 1177 err = -EFAULT; 1178 } else 1179 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1180 break; 1181 1182 case SIOCDELTUNNEL: 1183 err = -EPERM; 1184 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1185 goto done; 1186 1187 if (dev == sitn->fb_tunnel_dev) { 1188 err = -EFAULT; 1189 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1190 goto done; 1191 err = -ENOENT; 1192 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 1193 goto done; 1194 err = -EPERM; 1195 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1196 goto done; 1197 dev = t->dev; 1198 } 1199 unregister_netdevice(dev); 1200 err = 0; 1201 break; 1202 1203 case SIOCGETPRL: 1204 err = -EINVAL; 1205 if (dev == sitn->fb_tunnel_dev) 1206 goto done; 1207 err = -ENOENT; 1208 if (!(t = netdev_priv(dev))) 1209 goto done; 1210 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1211 break; 1212 1213 case SIOCADDPRL: 1214 case SIOCDELPRL: 1215 case SIOCCHGPRL: 1216 err = -EPERM; 1217 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1218 goto done; 1219 err = -EINVAL; 1220 if (dev == sitn->fb_tunnel_dev) 1221 goto done; 1222 err = -EFAULT; 1223 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1224 goto done; 1225 err = -ENOENT; 1226 if (!(t = netdev_priv(dev))) 1227 goto done; 1228 1229 switch (cmd) { 1230 case SIOCDELPRL: 1231 err = ipip6_tunnel_del_prl(t, &prl); 1232 break; 1233 case SIOCADDPRL: 1234 case SIOCCHGPRL: 1235 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1236 break; 1237 } 1238 netdev_state_change(dev); 1239 break; 1240 1241 #ifdef CONFIG_IPV6_SIT_6RD 1242 case SIOCADD6RD: 1243 case SIOCCHG6RD: 1244 case SIOCDEL6RD: 1245 err = -EPERM; 1246 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1247 goto done; 1248 1249 err = -EFAULT; 1250 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1251 sizeof(ip6rd))) 1252 goto done; 1253 1254 t = netdev_priv(dev); 1255 1256 if (cmd != SIOCDEL6RD) { 1257 err = ipip6_tunnel_update_6rd(t, &ip6rd); 1258 if (err < 0) 1259 goto done; 1260 } else 1261 ipip6_tunnel_clone_6rd(dev, sitn); 1262 1263 err = 0; 1264 break; 1265 #endif 1266 1267 default: 1268 err = -EINVAL; 1269 } 1270 1271 done: 1272 return err; 1273 } 1274 1275 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1276 { 1277 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1278 return -EINVAL; 1279 dev->mtu = new_mtu; 1280 return 0; 1281 } 1282 1283 static const struct net_device_ops ipip6_netdev_ops = { 1284 .ndo_uninit = ipip6_tunnel_uninit, 1285 .ndo_start_xmit = sit_tunnel_xmit, 1286 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1287 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1288 .ndo_get_stats64 = ip_tunnel_get_stats64, 1289 }; 1290 1291 static void ipip6_dev_free(struct net_device *dev) 1292 { 1293 free_percpu(dev->tstats); 1294 free_netdev(dev); 1295 } 1296 1297 #define SIT_FEATURES (NETIF_F_SG | \ 1298 NETIF_F_FRAGLIST | \ 1299 NETIF_F_HIGHDMA | \ 1300 NETIF_F_GSO_SOFTWARE | \ 1301 NETIF_F_HW_CSUM) 1302 1303 static void ipip6_tunnel_setup(struct net_device *dev) 1304 { 1305 dev->netdev_ops = &ipip6_netdev_ops; 1306 dev->destructor = ipip6_dev_free; 1307 1308 dev->type = ARPHRD_SIT; 1309 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1310 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1311 dev->flags = IFF_NOARP; 1312 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1313 dev->iflink = 0; 1314 dev->addr_len = 4; 1315 dev->features |= NETIF_F_LLTX; 1316 dev->features |= SIT_FEATURES; 1317 dev->hw_features |= SIT_FEATURES; 1318 } 1319 1320 static int ipip6_tunnel_init(struct net_device *dev) 1321 { 1322 struct ip_tunnel *tunnel = netdev_priv(dev); 1323 int i; 1324 1325 tunnel->dev = dev; 1326 tunnel->net = dev_net(dev); 1327 1328 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1329 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1330 1331 ipip6_tunnel_bind_dev(dev); 1332 dev->tstats = alloc_percpu(struct pcpu_tstats); 1333 if (!dev->tstats) 1334 return -ENOMEM; 1335 1336 for_each_possible_cpu(i) { 1337 struct pcpu_tstats *ipip6_tunnel_stats; 1338 ipip6_tunnel_stats = per_cpu_ptr(dev->tstats, i); 1339 u64_stats_init(&ipip6_tunnel_stats->syncp); 1340 } 1341 1342 return 0; 1343 } 1344 1345 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1346 { 1347 struct ip_tunnel *tunnel = netdev_priv(dev); 1348 struct iphdr *iph = &tunnel->parms.iph; 1349 struct net *net = dev_net(dev); 1350 struct sit_net *sitn = net_generic(net, sit_net_id); 1351 int i; 1352 1353 tunnel->dev = dev; 1354 tunnel->net = dev_net(dev); 1355 strcpy(tunnel->parms.name, dev->name); 1356 1357 iph->version = 4; 1358 iph->protocol = IPPROTO_IPV6; 1359 iph->ihl = 5; 1360 iph->ttl = 64; 1361 1362 dev->tstats = alloc_percpu(struct pcpu_tstats); 1363 if (!dev->tstats) 1364 return -ENOMEM; 1365 1366 for_each_possible_cpu(i) { 1367 struct pcpu_tstats *ipip6_fb_stats; 1368 ipip6_fb_stats = per_cpu_ptr(dev->tstats, i); 1369 u64_stats_init(&ipip6_fb_stats->syncp); 1370 } 1371 1372 dev_hold(dev); 1373 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1374 return 0; 1375 } 1376 1377 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[]) 1378 { 1379 u8 proto; 1380 1381 if (!data || !data[IFLA_IPTUN_PROTO]) 1382 return 0; 1383 1384 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1385 if (proto != IPPROTO_IPV6 && 1386 proto != IPPROTO_IPIP && 1387 proto != 0) 1388 return -EINVAL; 1389 1390 return 0; 1391 } 1392 1393 static void ipip6_netlink_parms(struct nlattr *data[], 1394 struct ip_tunnel_parm *parms) 1395 { 1396 memset(parms, 0, sizeof(*parms)); 1397 1398 parms->iph.version = 4; 1399 parms->iph.protocol = IPPROTO_IPV6; 1400 parms->iph.ihl = 5; 1401 parms->iph.ttl = 64; 1402 1403 if (!data) 1404 return; 1405 1406 if (data[IFLA_IPTUN_LINK]) 1407 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1408 1409 if (data[IFLA_IPTUN_LOCAL]) 1410 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); 1411 1412 if (data[IFLA_IPTUN_REMOTE]) 1413 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); 1414 1415 if (data[IFLA_IPTUN_TTL]) { 1416 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); 1417 if (parms->iph.ttl) 1418 parms->iph.frag_off = htons(IP_DF); 1419 } 1420 1421 if (data[IFLA_IPTUN_TOS]) 1422 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); 1423 1424 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) 1425 parms->iph.frag_off = htons(IP_DF); 1426 1427 if (data[IFLA_IPTUN_FLAGS]) 1428 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); 1429 1430 if (data[IFLA_IPTUN_PROTO]) 1431 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1432 1433 } 1434 1435 #ifdef CONFIG_IPV6_SIT_6RD 1436 /* This function returns true when 6RD attributes are present in the nl msg */ 1437 static bool ipip6_netlink_6rd_parms(struct nlattr *data[], 1438 struct ip_tunnel_6rd *ip6rd) 1439 { 1440 bool ret = false; 1441 memset(ip6rd, 0, sizeof(*ip6rd)); 1442 1443 if (!data) 1444 return ret; 1445 1446 if (data[IFLA_IPTUN_6RD_PREFIX]) { 1447 ret = true; 1448 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX], 1449 sizeof(struct in6_addr)); 1450 } 1451 1452 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { 1453 ret = true; 1454 ip6rd->relay_prefix = 1455 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); 1456 } 1457 1458 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { 1459 ret = true; 1460 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); 1461 } 1462 1463 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { 1464 ret = true; 1465 ip6rd->relay_prefixlen = 1466 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); 1467 } 1468 1469 return ret; 1470 } 1471 #endif 1472 1473 static int ipip6_newlink(struct net *src_net, struct net_device *dev, 1474 struct nlattr *tb[], struct nlattr *data[]) 1475 { 1476 struct net *net = dev_net(dev); 1477 struct ip_tunnel *nt; 1478 #ifdef CONFIG_IPV6_SIT_6RD 1479 struct ip_tunnel_6rd ip6rd; 1480 #endif 1481 int err; 1482 1483 nt = netdev_priv(dev); 1484 ipip6_netlink_parms(data, &nt->parms); 1485 1486 if (ipip6_tunnel_locate(net, &nt->parms, 0)) 1487 return -EEXIST; 1488 1489 err = ipip6_tunnel_create(dev); 1490 if (err < 0) 1491 return err; 1492 1493 #ifdef CONFIG_IPV6_SIT_6RD 1494 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1495 err = ipip6_tunnel_update_6rd(nt, &ip6rd); 1496 #endif 1497 1498 return err; 1499 } 1500 1501 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], 1502 struct nlattr *data[]) 1503 { 1504 struct ip_tunnel *t = netdev_priv(dev); 1505 struct ip_tunnel_parm p; 1506 struct net *net = t->net; 1507 struct sit_net *sitn = net_generic(net, sit_net_id); 1508 #ifdef CONFIG_IPV6_SIT_6RD 1509 struct ip_tunnel_6rd ip6rd; 1510 #endif 1511 1512 if (dev == sitn->fb_tunnel_dev) 1513 return -EINVAL; 1514 1515 ipip6_netlink_parms(data, &p); 1516 1517 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || 1518 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) 1519 return -EINVAL; 1520 1521 t = ipip6_tunnel_locate(net, &p, 0); 1522 1523 if (t) { 1524 if (t->dev != dev) 1525 return -EEXIST; 1526 } else 1527 t = netdev_priv(dev); 1528 1529 ipip6_tunnel_update(t, &p); 1530 1531 #ifdef CONFIG_IPV6_SIT_6RD 1532 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1533 return ipip6_tunnel_update_6rd(t, &ip6rd); 1534 #endif 1535 1536 return 0; 1537 } 1538 1539 static size_t ipip6_get_size(const struct net_device *dev) 1540 { 1541 return 1542 /* IFLA_IPTUN_LINK */ 1543 nla_total_size(4) + 1544 /* IFLA_IPTUN_LOCAL */ 1545 nla_total_size(4) + 1546 /* IFLA_IPTUN_REMOTE */ 1547 nla_total_size(4) + 1548 /* IFLA_IPTUN_TTL */ 1549 nla_total_size(1) + 1550 /* IFLA_IPTUN_TOS */ 1551 nla_total_size(1) + 1552 /* IFLA_IPTUN_PMTUDISC */ 1553 nla_total_size(1) + 1554 /* IFLA_IPTUN_FLAGS */ 1555 nla_total_size(2) + 1556 /* IFLA_IPTUN_PROTO */ 1557 nla_total_size(1) + 1558 #ifdef CONFIG_IPV6_SIT_6RD 1559 /* IFLA_IPTUN_6RD_PREFIX */ 1560 nla_total_size(sizeof(struct in6_addr)) + 1561 /* IFLA_IPTUN_6RD_RELAY_PREFIX */ 1562 nla_total_size(4) + 1563 /* IFLA_IPTUN_6RD_PREFIXLEN */ 1564 nla_total_size(2) + 1565 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ 1566 nla_total_size(2) + 1567 #endif 1568 0; 1569 } 1570 1571 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1572 { 1573 struct ip_tunnel *tunnel = netdev_priv(dev); 1574 struct ip_tunnel_parm *parm = &tunnel->parms; 1575 1576 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1577 nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || 1578 nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || 1579 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || 1580 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || 1581 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, 1582 !!(parm->iph.frag_off & htons(IP_DF))) || 1583 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || 1584 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags)) 1585 goto nla_put_failure; 1586 1587 #ifdef CONFIG_IPV6_SIT_6RD 1588 if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr), 1589 &tunnel->ip6rd.prefix) || 1590 nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, 1591 tunnel->ip6rd.relay_prefix) || 1592 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, 1593 tunnel->ip6rd.prefixlen) || 1594 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, 1595 tunnel->ip6rd.relay_prefixlen)) 1596 goto nla_put_failure; 1597 #endif 1598 1599 return 0; 1600 1601 nla_put_failure: 1602 return -EMSGSIZE; 1603 } 1604 1605 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { 1606 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1607 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, 1608 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, 1609 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1610 [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, 1611 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, 1612 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, 1613 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1614 #ifdef CONFIG_IPV6_SIT_6RD 1615 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, 1616 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, 1617 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, 1618 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, 1619 #endif 1620 }; 1621 1622 static void ipip6_dellink(struct net_device *dev, struct list_head *head) 1623 { 1624 struct net *net = dev_net(dev); 1625 struct sit_net *sitn = net_generic(net, sit_net_id); 1626 1627 if (dev != sitn->fb_tunnel_dev) 1628 unregister_netdevice_queue(dev, head); 1629 } 1630 1631 static struct rtnl_link_ops sit_link_ops __read_mostly = { 1632 .kind = "sit", 1633 .maxtype = IFLA_IPTUN_MAX, 1634 .policy = ipip6_policy, 1635 .priv_size = sizeof(struct ip_tunnel), 1636 .setup = ipip6_tunnel_setup, 1637 .validate = ipip6_validate, 1638 .newlink = ipip6_newlink, 1639 .changelink = ipip6_changelink, 1640 .get_size = ipip6_get_size, 1641 .fill_info = ipip6_fill_info, 1642 .dellink = ipip6_dellink, 1643 }; 1644 1645 static struct xfrm_tunnel sit_handler __read_mostly = { 1646 .handler = ipip6_rcv, 1647 .err_handler = ipip6_err, 1648 .priority = 1, 1649 }; 1650 1651 static struct xfrm_tunnel ipip_handler __read_mostly = { 1652 .handler = ipip_rcv, 1653 .err_handler = ipip6_err, 1654 .priority = 2, 1655 }; 1656 1657 static void __net_exit sit_destroy_tunnels(struct net *net, 1658 struct list_head *head) 1659 { 1660 struct sit_net *sitn = net_generic(net, sit_net_id); 1661 struct net_device *dev, *aux; 1662 int prio; 1663 1664 for_each_netdev_safe(net, dev, aux) 1665 if (dev->rtnl_link_ops == &sit_link_ops) 1666 unregister_netdevice_queue(dev, head); 1667 1668 for (prio = 1; prio < 4; prio++) { 1669 int h; 1670 for (h = 0; h < HASH_SIZE; h++) { 1671 struct ip_tunnel *t; 1672 1673 t = rtnl_dereference(sitn->tunnels[prio][h]); 1674 while (t != NULL) { 1675 /* If dev is in the same netns, it has already 1676 * been added to the list by the previous loop. 1677 */ 1678 if (!net_eq(dev_net(t->dev), net)) 1679 unregister_netdevice_queue(t->dev, 1680 head); 1681 t = rtnl_dereference(t->next); 1682 } 1683 } 1684 } 1685 } 1686 1687 static int __net_init sit_init_net(struct net *net) 1688 { 1689 struct sit_net *sitn = net_generic(net, sit_net_id); 1690 struct ip_tunnel *t; 1691 int err; 1692 1693 sitn->tunnels[0] = sitn->tunnels_wc; 1694 sitn->tunnels[1] = sitn->tunnels_l; 1695 sitn->tunnels[2] = sitn->tunnels_r; 1696 sitn->tunnels[3] = sitn->tunnels_r_l; 1697 1698 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1699 ipip6_tunnel_setup); 1700 if (!sitn->fb_tunnel_dev) { 1701 err = -ENOMEM; 1702 goto err_alloc_dev; 1703 } 1704 dev_net_set(sitn->fb_tunnel_dev, net); 1705 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; 1706 /* FB netdevice is special: we have one, and only one per netns. 1707 * Allowing to move it to another netns is clearly unsafe. 1708 */ 1709 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1710 1711 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1712 if (err) 1713 goto err_dev_free; 1714 1715 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1716 1717 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1718 goto err_reg_dev; 1719 1720 t = netdev_priv(sitn->fb_tunnel_dev); 1721 1722 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1723 return 0; 1724 1725 err_reg_dev: 1726 dev_put(sitn->fb_tunnel_dev); 1727 err_dev_free: 1728 ipip6_dev_free(sitn->fb_tunnel_dev); 1729 err_alloc_dev: 1730 return err; 1731 } 1732 1733 static void __net_exit sit_exit_net(struct net *net) 1734 { 1735 LIST_HEAD(list); 1736 1737 rtnl_lock(); 1738 sit_destroy_tunnels(net, &list); 1739 unregister_netdevice_many(&list); 1740 rtnl_unlock(); 1741 } 1742 1743 static struct pernet_operations sit_net_ops = { 1744 .init = sit_init_net, 1745 .exit = sit_exit_net, 1746 .id = &sit_net_id, 1747 .size = sizeof(struct sit_net), 1748 }; 1749 1750 static void __exit sit_cleanup(void) 1751 { 1752 rtnl_link_unregister(&sit_link_ops); 1753 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1754 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1755 1756 unregister_pernet_device(&sit_net_ops); 1757 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1758 } 1759 1760 static int __init sit_init(void) 1761 { 1762 int err; 1763 1764 pr_info("IPv6 over IPv4 tunneling driver\n"); 1765 1766 err = register_pernet_device(&sit_net_ops); 1767 if (err < 0) 1768 return err; 1769 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1770 if (err < 0) { 1771 pr_info("%s: can't register ip6ip4\n", __func__); 1772 goto xfrm_tunnel_failed; 1773 } 1774 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 1775 if (err < 0) { 1776 pr_info("%s: can't register ip4ip4\n", __func__); 1777 goto xfrm_tunnel4_failed; 1778 } 1779 err = rtnl_link_register(&sit_link_ops); 1780 if (err < 0) 1781 goto rtnl_link_failed; 1782 1783 out: 1784 return err; 1785 1786 rtnl_link_failed: 1787 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1788 xfrm_tunnel4_failed: 1789 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1790 xfrm_tunnel_failed: 1791 unregister_pernet_device(&sit_net_ops); 1792 goto out; 1793 } 1794 1795 module_init(sit_init); 1796 module_exit(sit_cleanup); 1797 MODULE_LICENSE("GPL"); 1798 MODULE_ALIAS_NETDEV("sit0"); 1799