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->ifindex == 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->ifindex == 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->ifindex == t->parms.link) && 117 (t->dev->flags & IFF_UP)) 118 return t; 119 } 120 t = rcu_dereference(sitn->tunnels_wc[0]); 121 if (t && (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 memcpy(dev->dev_addr, &t->parms.iph.saddr, 4); 199 memcpy(dev->broadcast, &t->parms.iph.daddr, 4); 200 201 if ((__force u16)t->parms.i_flags & SIT_ISATAP) 202 dev->priv_flags |= IFF_ISATAP; 203 204 err = register_netdevice(dev); 205 if (err < 0) 206 goto out; 207 208 ipip6_tunnel_clone_6rd(dev, sitn); 209 210 dev->rtnl_link_ops = &sit_link_ops; 211 212 dev_hold(dev); 213 214 ipip6_tunnel_link(sitn, t); 215 return 0; 216 217 out: 218 return err; 219 } 220 221 static struct ip_tunnel *ipip6_tunnel_locate(struct net *net, 222 struct ip_tunnel_parm *parms, int create) 223 { 224 __be32 remote = parms->iph.daddr; 225 __be32 local = parms->iph.saddr; 226 struct ip_tunnel *t, *nt; 227 struct ip_tunnel __rcu **tp; 228 struct net_device *dev; 229 char name[IFNAMSIZ]; 230 struct sit_net *sitn = net_generic(net, sit_net_id); 231 232 for (tp = __ipip6_bucket(sitn, parms); 233 (t = rtnl_dereference(*tp)) != NULL; 234 tp = &t->next) { 235 if (local == t->parms.iph.saddr && 236 remote == t->parms.iph.daddr && 237 parms->link == t->parms.link) { 238 if (create) 239 return NULL; 240 else 241 return t; 242 } 243 } 244 if (!create) 245 goto failed; 246 247 if (parms->name[0]) 248 strlcpy(name, parms->name, IFNAMSIZ); 249 else 250 strcpy(name, "sit%d"); 251 252 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, 253 ipip6_tunnel_setup); 254 if (!dev) 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 ip_tunnel_dst_reset_all(tunnel); 479 dev_put(dev); 480 } 481 482 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH 483 * if sufficient data bytes are available 484 */ 485 static int ipip6_err_gen_icmpv6_unreach(struct sk_buff *skb) 486 { 487 int ihl = ((const struct iphdr *)skb->data)->ihl*4; 488 struct rt6_info *rt; 489 struct sk_buff *skb2; 490 491 if (!pskb_may_pull(skb, ihl + sizeof(struct ipv6hdr) + 8)) 492 return 1; 493 494 skb2 = skb_clone(skb, GFP_ATOMIC); 495 496 if (!skb2) 497 return 1; 498 499 skb_dst_drop(skb2); 500 skb_pull(skb2, ihl); 501 skb_reset_network_header(skb2); 502 503 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0); 504 505 if (rt && rt->dst.dev) 506 skb2->dev = rt->dst.dev; 507 508 icmpv6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); 509 510 if (rt) 511 ip6_rt_put(rt); 512 513 kfree_skb(skb2); 514 515 return 0; 516 } 517 518 static int ipip6_err(struct sk_buff *skb, u32 info) 519 { 520 const struct iphdr *iph = (const struct iphdr *)skb->data; 521 const int type = icmp_hdr(skb)->type; 522 const int code = icmp_hdr(skb)->code; 523 struct ip_tunnel *t; 524 int err; 525 526 switch (type) { 527 default: 528 case ICMP_PARAMETERPROB: 529 return 0; 530 531 case ICMP_DEST_UNREACH: 532 switch (code) { 533 case ICMP_SR_FAILED: 534 /* Impossible event. */ 535 return 0; 536 default: 537 /* All others are translated to HOST_UNREACH. 538 rfc2003 contains "deep thoughts" about NET_UNREACH, 539 I believe they are just ether pollution. --ANK 540 */ 541 break; 542 } 543 break; 544 case ICMP_TIME_EXCEEDED: 545 if (code != ICMP_EXC_TTL) 546 return 0; 547 break; 548 case ICMP_REDIRECT: 549 break; 550 } 551 552 err = -ENOENT; 553 554 t = ipip6_tunnel_lookup(dev_net(skb->dev), 555 skb->dev, 556 iph->daddr, 557 iph->saddr); 558 if (!t) 559 goto out; 560 561 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 562 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 563 t->parms.link, 0, IPPROTO_IPV6, 0); 564 err = 0; 565 goto out; 566 } 567 if (type == ICMP_REDIRECT) { 568 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0, 569 IPPROTO_IPV6, 0); 570 err = 0; 571 goto out; 572 } 573 574 if (t->parms.iph.daddr == 0) 575 goto out; 576 577 err = 0; 578 if (!ipip6_err_gen_icmpv6_unreach(skb)) 579 goto out; 580 581 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 582 goto out; 583 584 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 585 t->err_count++; 586 else 587 t->err_count = 1; 588 t->err_time = jiffies; 589 out: 590 return err; 591 } 592 593 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, 594 const struct in6_addr *v6addr) 595 { 596 __be32 v4embed = 0; 597 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) 598 return true; 599 return false; 600 } 601 602 /* Checks if an address matches an address on the tunnel interface. 603 * Used to detect the NAT of proto 41 packets and let them pass spoofing test. 604 * Long story: 605 * This function is called after we considered the packet as spoofed 606 * in is_spoofed_6rd. 607 * We may have a router that is doing NAT for proto 41 packets 608 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb 609 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd 610 * function will return true, dropping the packet. 611 * But, we can still check if is spoofed against the IP 612 * addresses associated with the interface. 613 */ 614 static bool only_dnatted(const struct ip_tunnel *tunnel, 615 const struct in6_addr *v6dst) 616 { 617 int prefix_len; 618 619 #ifdef CONFIG_IPV6_SIT_6RD 620 prefix_len = tunnel->ip6rd.prefixlen + 32 621 - tunnel->ip6rd.relay_prefixlen; 622 #else 623 prefix_len = 48; 624 #endif 625 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev); 626 } 627 628 /* Returns true if a packet is spoofed */ 629 static bool packet_is_spoofed(struct sk_buff *skb, 630 const struct iphdr *iph, 631 struct ip_tunnel *tunnel) 632 { 633 const struct ipv6hdr *ipv6h; 634 635 if (tunnel->dev->priv_flags & IFF_ISATAP) { 636 if (!isatap_chksrc(skb, iph, tunnel)) 637 return true; 638 639 return false; 640 } 641 642 if (tunnel->dev->flags & IFF_POINTOPOINT) 643 return false; 644 645 ipv6h = ipv6_hdr(skb); 646 647 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) { 648 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 649 &iph->saddr, &ipv6h->saddr, 650 &iph->daddr, &ipv6h->daddr); 651 return true; 652 } 653 654 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr))) 655 return false; 656 657 if (only_dnatted(tunnel, &ipv6h->daddr)) 658 return false; 659 660 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 661 &iph->saddr, &ipv6h->saddr, 662 &iph->daddr, &ipv6h->daddr); 663 return true; 664 } 665 666 static int ipip6_rcv(struct sk_buff *skb) 667 { 668 const struct iphdr *iph = ip_hdr(skb); 669 struct ip_tunnel *tunnel; 670 int err; 671 672 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 673 iph->saddr, iph->daddr); 674 if (tunnel) { 675 struct pcpu_sw_netstats *tstats; 676 677 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && 678 tunnel->parms.iph.protocol != 0) 679 goto out; 680 681 skb->mac_header = skb->network_header; 682 skb_reset_network_header(skb); 683 IPCB(skb)->flags = 0; 684 skb->protocol = htons(ETH_P_IPV6); 685 686 if (packet_is_spoofed(skb, iph, tunnel)) { 687 tunnel->dev->stats.rx_errors++; 688 goto out; 689 } 690 691 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net); 692 693 err = IP_ECN_decapsulate(iph, skb); 694 if (unlikely(err)) { 695 if (log_ecn_error) 696 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 697 &iph->saddr, iph->tos); 698 if (err > 1) { 699 ++tunnel->dev->stats.rx_frame_errors; 700 ++tunnel->dev->stats.rx_errors; 701 goto out; 702 } 703 } 704 705 tstats = this_cpu_ptr(tunnel->dev->tstats); 706 u64_stats_update_begin(&tstats->syncp); 707 tstats->rx_packets++; 708 tstats->rx_bytes += skb->len; 709 u64_stats_update_end(&tstats->syncp); 710 711 netif_rx(skb); 712 713 return 0; 714 } 715 716 /* no tunnel matched, let upstream know, ipsec may handle it */ 717 return 1; 718 out: 719 kfree_skb(skb); 720 return 0; 721 } 722 723 static const struct tnl_ptk_info tpi = { 724 /* no tunnel info required for ipip. */ 725 .proto = htons(ETH_P_IP), 726 }; 727 728 static int ipip_rcv(struct sk_buff *skb) 729 { 730 const struct iphdr *iph; 731 struct ip_tunnel *tunnel; 732 733 iph = ip_hdr(skb); 734 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 735 iph->saddr, iph->daddr); 736 if (tunnel) { 737 if (tunnel->parms.iph.protocol != IPPROTO_IPIP && 738 tunnel->parms.iph.protocol != 0) 739 goto drop; 740 741 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 742 goto drop; 743 if (iptunnel_pull_header(skb, 0, tpi.proto)) 744 goto drop; 745 return ip_tunnel_rcv(tunnel, skb, &tpi, NULL, log_ecn_error); 746 } 747 748 return 1; 749 750 drop: 751 kfree_skb(skb); 752 return 0; 753 } 754 755 /* 756 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function 757 * stores the embedded IPv4 address in v4dst and returns true. 758 */ 759 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 760 __be32 *v4dst) 761 { 762 #ifdef CONFIG_IPV6_SIT_6RD 763 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 764 tunnel->ip6rd.prefixlen)) { 765 unsigned int pbw0, pbi0; 766 int pbi1; 767 u32 d; 768 769 pbw0 = tunnel->ip6rd.prefixlen >> 5; 770 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 771 772 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 773 tunnel->ip6rd.relay_prefixlen; 774 775 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 776 if (pbi1 > 0) 777 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 778 (32 - pbi1); 779 780 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); 781 return true; 782 } 783 #else 784 if (v6dst->s6_addr16[0] == htons(0x2002)) { 785 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 786 memcpy(v4dst, &v6dst->s6_addr16[1], 4); 787 return true; 788 } 789 #endif 790 return false; 791 } 792 793 static inline __be32 try_6rd(struct ip_tunnel *tunnel, 794 const struct in6_addr *v6dst) 795 { 796 __be32 dst = 0; 797 check_6rd(tunnel, v6dst, &dst); 798 return dst; 799 } 800 801 /* 802 * This function assumes it is being called from dev_queue_xmit() 803 * and that skb is filled properly by that function. 804 */ 805 806 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 807 struct net_device *dev) 808 { 809 struct ip_tunnel *tunnel = netdev_priv(dev); 810 const struct iphdr *tiph = &tunnel->parms.iph; 811 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 812 u8 tos = tunnel->parms.iph.tos; 813 __be16 df = tiph->frag_off; 814 struct rtable *rt; /* Route to the other host */ 815 struct net_device *tdev; /* Device to other host */ 816 unsigned int max_headroom; /* The extra header space needed */ 817 __be32 dst = tiph->daddr; 818 struct flowi4 fl4; 819 int mtu; 820 const struct in6_addr *addr6; 821 int addr_type; 822 u8 ttl; 823 u8 protocol = IPPROTO_IPV6; 824 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 825 826 if (skb->protocol != htons(ETH_P_IPV6)) 827 goto tx_error; 828 829 if (tos == 1) 830 tos = ipv6_get_dsfield(iph6); 831 832 /* ISATAP (RFC4214) - must come before 6to4 */ 833 if (dev->priv_flags & IFF_ISATAP) { 834 struct neighbour *neigh = NULL; 835 bool do_tx_error = false; 836 837 if (skb_dst(skb)) 838 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 839 840 if (!neigh) { 841 net_dbg_ratelimited("nexthop == NULL\n"); 842 goto tx_error; 843 } 844 845 addr6 = (const struct in6_addr *)&neigh->primary_key; 846 addr_type = ipv6_addr_type(addr6); 847 848 if ((addr_type & IPV6_ADDR_UNICAST) && 849 ipv6_addr_is_isatap(addr6)) 850 dst = addr6->s6_addr32[3]; 851 else 852 do_tx_error = true; 853 854 neigh_release(neigh); 855 if (do_tx_error) 856 goto tx_error; 857 } 858 859 if (!dst) 860 dst = try_6rd(tunnel, &iph6->daddr); 861 862 if (!dst) { 863 struct neighbour *neigh = NULL; 864 bool do_tx_error = false; 865 866 if (skb_dst(skb)) 867 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 868 869 if (!neigh) { 870 net_dbg_ratelimited("nexthop == NULL\n"); 871 goto tx_error; 872 } 873 874 addr6 = (const struct in6_addr *)&neigh->primary_key; 875 addr_type = ipv6_addr_type(addr6); 876 877 if (addr_type == IPV6_ADDR_ANY) { 878 addr6 = &ipv6_hdr(skb)->daddr; 879 addr_type = ipv6_addr_type(addr6); 880 } 881 882 if ((addr_type & IPV6_ADDR_COMPATv4) != 0) 883 dst = addr6->s6_addr32[3]; 884 else 885 do_tx_error = true; 886 887 neigh_release(neigh); 888 if (do_tx_error) 889 goto tx_error; 890 } 891 892 rt = ip_route_output_ports(tunnel->net, &fl4, NULL, 893 dst, tiph->saddr, 894 0, 0, 895 IPPROTO_IPV6, RT_TOS(tos), 896 tunnel->parms.link); 897 if (IS_ERR(rt)) { 898 dev->stats.tx_carrier_errors++; 899 goto tx_error_icmp; 900 } 901 if (rt->rt_type != RTN_UNICAST) { 902 ip_rt_put(rt); 903 dev->stats.tx_carrier_errors++; 904 goto tx_error_icmp; 905 } 906 tdev = rt->dst.dev; 907 908 if (tdev == dev) { 909 ip_rt_put(rt); 910 dev->stats.collisions++; 911 goto tx_error; 912 } 913 914 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT); 915 if (IS_ERR(skb)) { 916 ip_rt_put(rt); 917 goto out; 918 } 919 920 if (df) { 921 mtu = dst_mtu(&rt->dst) - t_hlen; 922 923 if (mtu < 68) { 924 dev->stats.collisions++; 925 ip_rt_put(rt); 926 goto tx_error; 927 } 928 929 if (mtu < IPV6_MIN_MTU) { 930 mtu = IPV6_MIN_MTU; 931 df = 0; 932 } 933 934 if (tunnel->parms.iph.daddr && skb_dst(skb)) 935 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 936 937 if (skb->len > mtu && !skb_is_gso(skb)) { 938 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 939 ip_rt_put(rt); 940 goto tx_error; 941 } 942 } 943 944 if (tunnel->err_count > 0) { 945 if (time_before(jiffies, 946 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 947 tunnel->err_count--; 948 dst_link_failure(skb); 949 } else 950 tunnel->err_count = 0; 951 } 952 953 /* 954 * Okay, now see if we can stuff it in the buffer as-is. 955 */ 956 max_headroom = LL_RESERVED_SPACE(tdev) + t_hlen; 957 958 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 959 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 960 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 961 if (!new_skb) { 962 ip_rt_put(rt); 963 dev->stats.tx_dropped++; 964 kfree_skb(skb); 965 return NETDEV_TX_OK; 966 } 967 if (skb->sk) 968 skb_set_owner_w(new_skb, skb->sk); 969 dev_kfree_skb(skb); 970 skb = new_skb; 971 iph6 = ipv6_hdr(skb); 972 } 973 ttl = tiph->ttl; 974 if (ttl == 0) 975 ttl = iph6->hop_limit; 976 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 977 978 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) { 979 ip_rt_put(rt); 980 goto tx_error; 981 } 982 983 skb_set_inner_ipproto(skb, IPPROTO_IPV6); 984 985 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, 986 df, !net_eq(tunnel->net, dev_net(dev))); 987 return NETDEV_TX_OK; 988 989 tx_error_icmp: 990 dst_link_failure(skb); 991 tx_error: 992 kfree_skb(skb); 993 out: 994 dev->stats.tx_errors++; 995 return NETDEV_TX_OK; 996 } 997 998 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 999 { 1000 struct ip_tunnel *tunnel = netdev_priv(dev); 1001 const struct iphdr *tiph = &tunnel->parms.iph; 1002 1003 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP); 1004 if (IS_ERR(skb)) 1005 goto out; 1006 1007 skb_set_inner_ipproto(skb, IPPROTO_IPIP); 1008 1009 ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP); 1010 return NETDEV_TX_OK; 1011 out: 1012 dev->stats.tx_errors++; 1013 return NETDEV_TX_OK; 1014 } 1015 1016 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, 1017 struct net_device *dev) 1018 { 1019 switch (skb->protocol) { 1020 case htons(ETH_P_IP): 1021 ipip_tunnel_xmit(skb, dev); 1022 break; 1023 case htons(ETH_P_IPV6): 1024 ipip6_tunnel_xmit(skb, dev); 1025 break; 1026 default: 1027 goto tx_err; 1028 } 1029 1030 return NETDEV_TX_OK; 1031 1032 tx_err: 1033 dev->stats.tx_errors++; 1034 kfree_skb(skb); 1035 return NETDEV_TX_OK; 1036 1037 } 1038 1039 static void ipip6_tunnel_bind_dev(struct net_device *dev) 1040 { 1041 struct net_device *tdev = NULL; 1042 struct ip_tunnel *tunnel; 1043 const struct iphdr *iph; 1044 struct flowi4 fl4; 1045 1046 tunnel = netdev_priv(dev); 1047 iph = &tunnel->parms.iph; 1048 1049 if (iph->daddr) { 1050 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, 1051 NULL, 1052 iph->daddr, iph->saddr, 1053 0, 0, 1054 IPPROTO_IPV6, 1055 RT_TOS(iph->tos), 1056 tunnel->parms.link); 1057 1058 if (!IS_ERR(rt)) { 1059 tdev = rt->dst.dev; 1060 ip_rt_put(rt); 1061 } 1062 dev->flags |= IFF_POINTOPOINT; 1063 } 1064 1065 if (!tdev && tunnel->parms.link) 1066 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 1067 1068 if (tdev) { 1069 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 1070 1071 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 1072 dev->mtu = tdev->mtu - t_hlen; 1073 if (dev->mtu < IPV6_MIN_MTU) 1074 dev->mtu = IPV6_MIN_MTU; 1075 } 1076 } 1077 1078 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p) 1079 { 1080 struct net *net = t->net; 1081 struct sit_net *sitn = net_generic(net, sit_net_id); 1082 1083 ipip6_tunnel_unlink(sitn, t); 1084 synchronize_net(); 1085 t->parms.iph.saddr = p->iph.saddr; 1086 t->parms.iph.daddr = p->iph.daddr; 1087 memcpy(t->dev->dev_addr, &p->iph.saddr, 4); 1088 memcpy(t->dev->broadcast, &p->iph.daddr, 4); 1089 ipip6_tunnel_link(sitn, t); 1090 t->parms.iph.ttl = p->iph.ttl; 1091 t->parms.iph.tos = p->iph.tos; 1092 if (t->parms.link != p->link) { 1093 t->parms.link = p->link; 1094 ipip6_tunnel_bind_dev(t->dev); 1095 } 1096 ip_tunnel_dst_reset_all(t); 1097 netdev_state_change(t->dev); 1098 } 1099 1100 #ifdef CONFIG_IPV6_SIT_6RD 1101 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, 1102 struct ip_tunnel_6rd *ip6rd) 1103 { 1104 struct in6_addr prefix; 1105 __be32 relay_prefix; 1106 1107 if (ip6rd->relay_prefixlen > 32 || 1108 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) 1109 return -EINVAL; 1110 1111 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); 1112 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) 1113 return -EINVAL; 1114 if (ip6rd->relay_prefixlen) 1115 relay_prefix = ip6rd->relay_prefix & 1116 htonl(0xffffffffUL << 1117 (32 - ip6rd->relay_prefixlen)); 1118 else 1119 relay_prefix = 0; 1120 if (relay_prefix != ip6rd->relay_prefix) 1121 return -EINVAL; 1122 1123 t->ip6rd.prefix = prefix; 1124 t->ip6rd.relay_prefix = relay_prefix; 1125 t->ip6rd.prefixlen = ip6rd->prefixlen; 1126 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; 1127 ip_tunnel_dst_reset_all(t); 1128 netdev_state_change(t->dev); 1129 return 0; 1130 } 1131 #endif 1132 1133 static int 1134 ipip6_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1135 { 1136 int err = 0; 1137 struct ip_tunnel_parm p; 1138 struct ip_tunnel_prl prl; 1139 struct ip_tunnel *t = netdev_priv(dev); 1140 struct net *net = t->net; 1141 struct sit_net *sitn = net_generic(net, sit_net_id); 1142 #ifdef CONFIG_IPV6_SIT_6RD 1143 struct ip_tunnel_6rd ip6rd; 1144 #endif 1145 1146 switch (cmd) { 1147 case SIOCGETTUNNEL: 1148 #ifdef CONFIG_IPV6_SIT_6RD 1149 case SIOCGET6RD: 1150 #endif 1151 if (dev == sitn->fb_tunnel_dev) { 1152 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 1153 err = -EFAULT; 1154 break; 1155 } 1156 t = ipip6_tunnel_locate(net, &p, 0); 1157 if (!t) 1158 t = netdev_priv(dev); 1159 } 1160 1161 err = -EFAULT; 1162 if (cmd == SIOCGETTUNNEL) { 1163 memcpy(&p, &t->parms, sizeof(p)); 1164 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 1165 sizeof(p))) 1166 goto done; 1167 #ifdef CONFIG_IPV6_SIT_6RD 1168 } else { 1169 ip6rd.prefix = t->ip6rd.prefix; 1170 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 1171 ip6rd.prefixlen = t->ip6rd.prefixlen; 1172 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 1173 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 1174 sizeof(ip6rd))) 1175 goto done; 1176 #endif 1177 } 1178 err = 0; 1179 break; 1180 1181 case SIOCADDTUNNEL: 1182 case SIOCCHGTUNNEL: 1183 err = -EPERM; 1184 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1185 goto done; 1186 1187 err = -EFAULT; 1188 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1189 goto done; 1190 1191 err = -EINVAL; 1192 if (p.iph.protocol != IPPROTO_IPV6 && 1193 p.iph.protocol != IPPROTO_IPIP && 1194 p.iph.protocol != 0) 1195 goto done; 1196 if (p.iph.version != 4 || 1197 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 1198 goto done; 1199 if (p.iph.ttl) 1200 p.iph.frag_off |= htons(IP_DF); 1201 1202 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 1203 1204 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 1205 if (t) { 1206 if (t->dev != dev) { 1207 err = -EEXIST; 1208 break; 1209 } 1210 } else { 1211 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 1212 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 1213 err = -EINVAL; 1214 break; 1215 } 1216 t = netdev_priv(dev); 1217 } 1218 1219 ipip6_tunnel_update(t, &p); 1220 } 1221 1222 if (t) { 1223 err = 0; 1224 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 1225 err = -EFAULT; 1226 } else 1227 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1228 break; 1229 1230 case SIOCDELTUNNEL: 1231 err = -EPERM; 1232 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1233 goto done; 1234 1235 if (dev == sitn->fb_tunnel_dev) { 1236 err = -EFAULT; 1237 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1238 goto done; 1239 err = -ENOENT; 1240 t = ipip6_tunnel_locate(net, &p, 0); 1241 if (!t) 1242 goto done; 1243 err = -EPERM; 1244 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1245 goto done; 1246 dev = t->dev; 1247 } 1248 unregister_netdevice(dev); 1249 err = 0; 1250 break; 1251 1252 case SIOCGETPRL: 1253 err = -EINVAL; 1254 if (dev == sitn->fb_tunnel_dev) 1255 goto done; 1256 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1257 break; 1258 1259 case SIOCADDPRL: 1260 case SIOCDELPRL: 1261 case SIOCCHGPRL: 1262 err = -EPERM; 1263 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1264 goto done; 1265 err = -EINVAL; 1266 if (dev == sitn->fb_tunnel_dev) 1267 goto done; 1268 err = -EFAULT; 1269 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1270 goto done; 1271 1272 switch (cmd) { 1273 case SIOCDELPRL: 1274 err = ipip6_tunnel_del_prl(t, &prl); 1275 break; 1276 case SIOCADDPRL: 1277 case SIOCCHGPRL: 1278 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1279 break; 1280 } 1281 ip_tunnel_dst_reset_all(t); 1282 netdev_state_change(dev); 1283 break; 1284 1285 #ifdef CONFIG_IPV6_SIT_6RD 1286 case SIOCADD6RD: 1287 case SIOCCHG6RD: 1288 case SIOCDEL6RD: 1289 err = -EPERM; 1290 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1291 goto done; 1292 1293 err = -EFAULT; 1294 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1295 sizeof(ip6rd))) 1296 goto done; 1297 1298 if (cmd != SIOCDEL6RD) { 1299 err = ipip6_tunnel_update_6rd(t, &ip6rd); 1300 if (err < 0) 1301 goto done; 1302 } else 1303 ipip6_tunnel_clone_6rd(dev, sitn); 1304 1305 err = 0; 1306 break; 1307 #endif 1308 1309 default: 1310 err = -EINVAL; 1311 } 1312 1313 done: 1314 return err; 1315 } 1316 1317 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1318 { 1319 struct ip_tunnel *tunnel = netdev_priv(dev); 1320 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 1321 1322 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - t_hlen) 1323 return -EINVAL; 1324 dev->mtu = new_mtu; 1325 return 0; 1326 } 1327 1328 static const struct net_device_ops ipip6_netdev_ops = { 1329 .ndo_init = ipip6_tunnel_init, 1330 .ndo_uninit = ipip6_tunnel_uninit, 1331 .ndo_start_xmit = sit_tunnel_xmit, 1332 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1333 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1334 .ndo_get_stats64 = ip_tunnel_get_stats64, 1335 .ndo_get_iflink = ip_tunnel_get_iflink, 1336 }; 1337 1338 static void ipip6_dev_free(struct net_device *dev) 1339 { 1340 struct ip_tunnel *tunnel = netdev_priv(dev); 1341 1342 free_percpu(tunnel->dst_cache); 1343 free_percpu(dev->tstats); 1344 free_netdev(dev); 1345 } 1346 1347 #define SIT_FEATURES (NETIF_F_SG | \ 1348 NETIF_F_FRAGLIST | \ 1349 NETIF_F_HIGHDMA | \ 1350 NETIF_F_GSO_SOFTWARE | \ 1351 NETIF_F_HW_CSUM) 1352 1353 static void ipip6_tunnel_setup(struct net_device *dev) 1354 { 1355 struct ip_tunnel *tunnel = netdev_priv(dev); 1356 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 1357 1358 dev->netdev_ops = &ipip6_netdev_ops; 1359 dev->destructor = ipip6_dev_free; 1360 1361 dev->type = ARPHRD_SIT; 1362 dev->hard_header_len = LL_MAX_HEADER + t_hlen; 1363 dev->mtu = ETH_DATA_LEN - t_hlen; 1364 dev->flags = IFF_NOARP; 1365 netif_keep_dst(dev); 1366 dev->addr_len = 4; 1367 dev->features |= NETIF_F_LLTX; 1368 dev->features |= SIT_FEATURES; 1369 dev->hw_features |= SIT_FEATURES; 1370 } 1371 1372 static int ipip6_tunnel_init(struct net_device *dev) 1373 { 1374 struct ip_tunnel *tunnel = netdev_priv(dev); 1375 1376 tunnel->dev = dev; 1377 tunnel->net = dev_net(dev); 1378 strcpy(tunnel->parms.name, dev->name); 1379 1380 ipip6_tunnel_bind_dev(dev); 1381 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1382 if (!dev->tstats) 1383 return -ENOMEM; 1384 1385 tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst); 1386 if (!tunnel->dst_cache) { 1387 free_percpu(dev->tstats); 1388 return -ENOMEM; 1389 } 1390 1391 return 0; 1392 } 1393 1394 static void __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1395 { 1396 struct ip_tunnel *tunnel = netdev_priv(dev); 1397 struct iphdr *iph = &tunnel->parms.iph; 1398 struct net *net = dev_net(dev); 1399 struct sit_net *sitn = net_generic(net, sit_net_id); 1400 1401 iph->version = 4; 1402 iph->protocol = IPPROTO_IPV6; 1403 iph->ihl = 5; 1404 iph->ttl = 64; 1405 1406 dev_hold(dev); 1407 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1408 } 1409 1410 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[]) 1411 { 1412 u8 proto; 1413 1414 if (!data || !data[IFLA_IPTUN_PROTO]) 1415 return 0; 1416 1417 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1418 if (proto != IPPROTO_IPV6 && 1419 proto != IPPROTO_IPIP && 1420 proto != 0) 1421 return -EINVAL; 1422 1423 return 0; 1424 } 1425 1426 static void ipip6_netlink_parms(struct nlattr *data[], 1427 struct ip_tunnel_parm *parms) 1428 { 1429 memset(parms, 0, sizeof(*parms)); 1430 1431 parms->iph.version = 4; 1432 parms->iph.protocol = IPPROTO_IPV6; 1433 parms->iph.ihl = 5; 1434 parms->iph.ttl = 64; 1435 1436 if (!data) 1437 return; 1438 1439 if (data[IFLA_IPTUN_LINK]) 1440 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1441 1442 if (data[IFLA_IPTUN_LOCAL]) 1443 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); 1444 1445 if (data[IFLA_IPTUN_REMOTE]) 1446 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); 1447 1448 if (data[IFLA_IPTUN_TTL]) { 1449 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); 1450 if (parms->iph.ttl) 1451 parms->iph.frag_off = htons(IP_DF); 1452 } 1453 1454 if (data[IFLA_IPTUN_TOS]) 1455 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); 1456 1457 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) 1458 parms->iph.frag_off = htons(IP_DF); 1459 1460 if (data[IFLA_IPTUN_FLAGS]) 1461 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); 1462 1463 if (data[IFLA_IPTUN_PROTO]) 1464 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1465 1466 } 1467 1468 /* This function returns true when ENCAP attributes are present in the nl msg */ 1469 static bool ipip6_netlink_encap_parms(struct nlattr *data[], 1470 struct ip_tunnel_encap *ipencap) 1471 { 1472 bool ret = false; 1473 1474 memset(ipencap, 0, sizeof(*ipencap)); 1475 1476 if (!data) 1477 return ret; 1478 1479 if (data[IFLA_IPTUN_ENCAP_TYPE]) { 1480 ret = true; 1481 ipencap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]); 1482 } 1483 1484 if (data[IFLA_IPTUN_ENCAP_FLAGS]) { 1485 ret = true; 1486 ipencap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]); 1487 } 1488 1489 if (data[IFLA_IPTUN_ENCAP_SPORT]) { 1490 ret = true; 1491 ipencap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]); 1492 } 1493 1494 if (data[IFLA_IPTUN_ENCAP_DPORT]) { 1495 ret = true; 1496 ipencap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]); 1497 } 1498 1499 return ret; 1500 } 1501 1502 #ifdef CONFIG_IPV6_SIT_6RD 1503 /* This function returns true when 6RD attributes are present in the nl msg */ 1504 static bool ipip6_netlink_6rd_parms(struct nlattr *data[], 1505 struct ip_tunnel_6rd *ip6rd) 1506 { 1507 bool ret = false; 1508 memset(ip6rd, 0, sizeof(*ip6rd)); 1509 1510 if (!data) 1511 return ret; 1512 1513 if (data[IFLA_IPTUN_6RD_PREFIX]) { 1514 ret = true; 1515 ip6rd->prefix = nla_get_in6_addr(data[IFLA_IPTUN_6RD_PREFIX]); 1516 } 1517 1518 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { 1519 ret = true; 1520 ip6rd->relay_prefix = 1521 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); 1522 } 1523 1524 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { 1525 ret = true; 1526 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); 1527 } 1528 1529 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { 1530 ret = true; 1531 ip6rd->relay_prefixlen = 1532 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); 1533 } 1534 1535 return ret; 1536 } 1537 #endif 1538 1539 static int ipip6_newlink(struct net *src_net, struct net_device *dev, 1540 struct nlattr *tb[], struct nlattr *data[]) 1541 { 1542 struct net *net = dev_net(dev); 1543 struct ip_tunnel *nt; 1544 struct ip_tunnel_encap ipencap; 1545 #ifdef CONFIG_IPV6_SIT_6RD 1546 struct ip_tunnel_6rd ip6rd; 1547 #endif 1548 int err; 1549 1550 nt = netdev_priv(dev); 1551 1552 if (ipip6_netlink_encap_parms(data, &ipencap)) { 1553 err = ip_tunnel_encap_setup(nt, &ipencap); 1554 if (err < 0) 1555 return err; 1556 } 1557 1558 ipip6_netlink_parms(data, &nt->parms); 1559 1560 if (ipip6_tunnel_locate(net, &nt->parms, 0)) 1561 return -EEXIST; 1562 1563 err = ipip6_tunnel_create(dev); 1564 if (err < 0) 1565 return err; 1566 1567 #ifdef CONFIG_IPV6_SIT_6RD 1568 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1569 err = ipip6_tunnel_update_6rd(nt, &ip6rd); 1570 #endif 1571 1572 return err; 1573 } 1574 1575 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], 1576 struct nlattr *data[]) 1577 { 1578 struct ip_tunnel *t = netdev_priv(dev); 1579 struct ip_tunnel_parm p; 1580 struct ip_tunnel_encap ipencap; 1581 struct net *net = t->net; 1582 struct sit_net *sitn = net_generic(net, sit_net_id); 1583 #ifdef CONFIG_IPV6_SIT_6RD 1584 struct ip_tunnel_6rd ip6rd; 1585 #endif 1586 int err; 1587 1588 if (dev == sitn->fb_tunnel_dev) 1589 return -EINVAL; 1590 1591 if (ipip6_netlink_encap_parms(data, &ipencap)) { 1592 err = ip_tunnel_encap_setup(t, &ipencap); 1593 if (err < 0) 1594 return err; 1595 } 1596 1597 ipip6_netlink_parms(data, &p); 1598 1599 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || 1600 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) 1601 return -EINVAL; 1602 1603 t = ipip6_tunnel_locate(net, &p, 0); 1604 1605 if (t) { 1606 if (t->dev != dev) 1607 return -EEXIST; 1608 } else 1609 t = netdev_priv(dev); 1610 1611 ipip6_tunnel_update(t, &p); 1612 1613 #ifdef CONFIG_IPV6_SIT_6RD 1614 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1615 return ipip6_tunnel_update_6rd(t, &ip6rd); 1616 #endif 1617 1618 return 0; 1619 } 1620 1621 static size_t ipip6_get_size(const struct net_device *dev) 1622 { 1623 return 1624 /* IFLA_IPTUN_LINK */ 1625 nla_total_size(4) + 1626 /* IFLA_IPTUN_LOCAL */ 1627 nla_total_size(4) + 1628 /* IFLA_IPTUN_REMOTE */ 1629 nla_total_size(4) + 1630 /* IFLA_IPTUN_TTL */ 1631 nla_total_size(1) + 1632 /* IFLA_IPTUN_TOS */ 1633 nla_total_size(1) + 1634 /* IFLA_IPTUN_PMTUDISC */ 1635 nla_total_size(1) + 1636 /* IFLA_IPTUN_FLAGS */ 1637 nla_total_size(2) + 1638 /* IFLA_IPTUN_PROTO */ 1639 nla_total_size(1) + 1640 #ifdef CONFIG_IPV6_SIT_6RD 1641 /* IFLA_IPTUN_6RD_PREFIX */ 1642 nla_total_size(sizeof(struct in6_addr)) + 1643 /* IFLA_IPTUN_6RD_RELAY_PREFIX */ 1644 nla_total_size(4) + 1645 /* IFLA_IPTUN_6RD_PREFIXLEN */ 1646 nla_total_size(2) + 1647 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ 1648 nla_total_size(2) + 1649 #endif 1650 /* IFLA_IPTUN_ENCAP_TYPE */ 1651 nla_total_size(2) + 1652 /* IFLA_IPTUN_ENCAP_FLAGS */ 1653 nla_total_size(2) + 1654 /* IFLA_IPTUN_ENCAP_SPORT */ 1655 nla_total_size(2) + 1656 /* IFLA_IPTUN_ENCAP_DPORT */ 1657 nla_total_size(2) + 1658 0; 1659 } 1660 1661 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1662 { 1663 struct ip_tunnel *tunnel = netdev_priv(dev); 1664 struct ip_tunnel_parm *parm = &tunnel->parms; 1665 1666 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1667 nla_put_in_addr(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || 1668 nla_put_in_addr(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || 1669 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || 1670 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || 1671 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, 1672 !!(parm->iph.frag_off & htons(IP_DF))) || 1673 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || 1674 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags)) 1675 goto nla_put_failure; 1676 1677 #ifdef CONFIG_IPV6_SIT_6RD 1678 if (nla_put_in6_addr(skb, IFLA_IPTUN_6RD_PREFIX, 1679 &tunnel->ip6rd.prefix) || 1680 nla_put_in_addr(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, 1681 tunnel->ip6rd.relay_prefix) || 1682 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, 1683 tunnel->ip6rd.prefixlen) || 1684 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, 1685 tunnel->ip6rd.relay_prefixlen)) 1686 goto nla_put_failure; 1687 #endif 1688 1689 if (nla_put_u16(skb, IFLA_IPTUN_ENCAP_TYPE, 1690 tunnel->encap.type) || 1691 nla_put_be16(skb, IFLA_IPTUN_ENCAP_SPORT, 1692 tunnel->encap.sport) || 1693 nla_put_be16(skb, IFLA_IPTUN_ENCAP_DPORT, 1694 tunnel->encap.dport) || 1695 nla_put_u16(skb, IFLA_IPTUN_ENCAP_FLAGS, 1696 tunnel->encap.flags)) 1697 goto nla_put_failure; 1698 1699 return 0; 1700 1701 nla_put_failure: 1702 return -EMSGSIZE; 1703 } 1704 1705 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { 1706 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1707 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, 1708 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, 1709 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1710 [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, 1711 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, 1712 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, 1713 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1714 #ifdef CONFIG_IPV6_SIT_6RD 1715 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, 1716 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, 1717 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, 1718 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, 1719 #endif 1720 [IFLA_IPTUN_ENCAP_TYPE] = { .type = NLA_U16 }, 1721 [IFLA_IPTUN_ENCAP_FLAGS] = { .type = NLA_U16 }, 1722 [IFLA_IPTUN_ENCAP_SPORT] = { .type = NLA_U16 }, 1723 [IFLA_IPTUN_ENCAP_DPORT] = { .type = NLA_U16 }, 1724 }; 1725 1726 static void ipip6_dellink(struct net_device *dev, struct list_head *head) 1727 { 1728 struct net *net = dev_net(dev); 1729 struct sit_net *sitn = net_generic(net, sit_net_id); 1730 1731 if (dev != sitn->fb_tunnel_dev) 1732 unregister_netdevice_queue(dev, head); 1733 } 1734 1735 static struct rtnl_link_ops sit_link_ops __read_mostly = { 1736 .kind = "sit", 1737 .maxtype = IFLA_IPTUN_MAX, 1738 .policy = ipip6_policy, 1739 .priv_size = sizeof(struct ip_tunnel), 1740 .setup = ipip6_tunnel_setup, 1741 .validate = ipip6_validate, 1742 .newlink = ipip6_newlink, 1743 .changelink = ipip6_changelink, 1744 .get_size = ipip6_get_size, 1745 .fill_info = ipip6_fill_info, 1746 .dellink = ipip6_dellink, 1747 .get_link_net = ip_tunnel_get_link_net, 1748 }; 1749 1750 static struct xfrm_tunnel sit_handler __read_mostly = { 1751 .handler = ipip6_rcv, 1752 .err_handler = ipip6_err, 1753 .priority = 1, 1754 }; 1755 1756 static struct xfrm_tunnel ipip_handler __read_mostly = { 1757 .handler = ipip_rcv, 1758 .err_handler = ipip6_err, 1759 .priority = 2, 1760 }; 1761 1762 static void __net_exit sit_destroy_tunnels(struct net *net, 1763 struct list_head *head) 1764 { 1765 struct sit_net *sitn = net_generic(net, sit_net_id); 1766 struct net_device *dev, *aux; 1767 int prio; 1768 1769 for_each_netdev_safe(net, dev, aux) 1770 if (dev->rtnl_link_ops == &sit_link_ops) 1771 unregister_netdevice_queue(dev, head); 1772 1773 for (prio = 1; prio < 4; prio++) { 1774 int h; 1775 for (h = 0; h < HASH_SIZE; h++) { 1776 struct ip_tunnel *t; 1777 1778 t = rtnl_dereference(sitn->tunnels[prio][h]); 1779 while (t) { 1780 /* If dev is in the same netns, it has already 1781 * been added to the list by the previous loop. 1782 */ 1783 if (!net_eq(dev_net(t->dev), net)) 1784 unregister_netdevice_queue(t->dev, 1785 head); 1786 t = rtnl_dereference(t->next); 1787 } 1788 } 1789 } 1790 } 1791 1792 static int __net_init sit_init_net(struct net *net) 1793 { 1794 struct sit_net *sitn = net_generic(net, sit_net_id); 1795 struct ip_tunnel *t; 1796 int err; 1797 1798 sitn->tunnels[0] = sitn->tunnels_wc; 1799 sitn->tunnels[1] = sitn->tunnels_l; 1800 sitn->tunnels[2] = sitn->tunnels_r; 1801 sitn->tunnels[3] = sitn->tunnels_r_l; 1802 1803 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1804 NET_NAME_UNKNOWN, 1805 ipip6_tunnel_setup); 1806 if (!sitn->fb_tunnel_dev) { 1807 err = -ENOMEM; 1808 goto err_alloc_dev; 1809 } 1810 dev_net_set(sitn->fb_tunnel_dev, net); 1811 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; 1812 /* FB netdevice is special: we have one, and only one per netns. 1813 * Allowing to move it to another netns is clearly unsafe. 1814 */ 1815 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1816 1817 err = register_netdev(sitn->fb_tunnel_dev); 1818 if (err) 1819 goto err_reg_dev; 1820 1821 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1822 ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1823 1824 t = netdev_priv(sitn->fb_tunnel_dev); 1825 1826 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1827 return 0; 1828 1829 err_reg_dev: 1830 ipip6_dev_free(sitn->fb_tunnel_dev); 1831 err_alloc_dev: 1832 return err; 1833 } 1834 1835 static void __net_exit sit_exit_net(struct net *net) 1836 { 1837 LIST_HEAD(list); 1838 1839 rtnl_lock(); 1840 sit_destroy_tunnels(net, &list); 1841 unregister_netdevice_many(&list); 1842 rtnl_unlock(); 1843 } 1844 1845 static struct pernet_operations sit_net_ops = { 1846 .init = sit_init_net, 1847 .exit = sit_exit_net, 1848 .id = &sit_net_id, 1849 .size = sizeof(struct sit_net), 1850 }; 1851 1852 static void __exit sit_cleanup(void) 1853 { 1854 rtnl_link_unregister(&sit_link_ops); 1855 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1856 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1857 1858 unregister_pernet_device(&sit_net_ops); 1859 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1860 } 1861 1862 static int __init sit_init(void) 1863 { 1864 int err; 1865 1866 pr_info("IPv6 over IPv4 tunneling driver\n"); 1867 1868 err = register_pernet_device(&sit_net_ops); 1869 if (err < 0) 1870 return err; 1871 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1872 if (err < 0) { 1873 pr_info("%s: can't register ip6ip4\n", __func__); 1874 goto xfrm_tunnel_failed; 1875 } 1876 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 1877 if (err < 0) { 1878 pr_info("%s: can't register ip4ip4\n", __func__); 1879 goto xfrm_tunnel4_failed; 1880 } 1881 err = rtnl_link_register(&sit_link_ops); 1882 if (err < 0) 1883 goto rtnl_link_failed; 1884 1885 out: 1886 return err; 1887 1888 rtnl_link_failed: 1889 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1890 xfrm_tunnel4_failed: 1891 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1892 xfrm_tunnel_failed: 1893 unregister_pernet_device(&sit_net_ops); 1894 goto out; 1895 } 1896 1897 module_init(sit_init); 1898 module_exit(sit_cleanup); 1899 MODULE_LICENSE("GPL"); 1900 MODULE_ALIAS_RTNL_LINK("sit"); 1901 MODULE_ALIAS_NETDEV("sit0"); 1902