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 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH 482 * if sufficient data bytes are available 483 */ 484 static int ipip6_err_gen_icmpv6_unreach(struct sk_buff *skb) 485 { 486 const struct iphdr *iph = (const struct iphdr *) skb->data; 487 struct rt6_info *rt; 488 struct sk_buff *skb2; 489 490 if (!pskb_may_pull(skb, iph->ihl * 4 + sizeof(struct ipv6hdr) + 8)) 491 return 1; 492 493 skb2 = skb_clone(skb, GFP_ATOMIC); 494 495 if (!skb2) 496 return 1; 497 498 skb_dst_drop(skb2); 499 skb_pull(skb2, iph->ihl * 4); 500 skb_reset_network_header(skb2); 501 502 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0); 503 504 if (rt && rt->dst.dev) 505 skb2->dev = rt->dst.dev; 506 507 icmpv6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); 508 509 if (rt) 510 ip6_rt_put(rt); 511 512 kfree_skb(skb2); 513 514 return 0; 515 } 516 517 static int ipip6_err(struct sk_buff *skb, u32 info) 518 { 519 const struct iphdr *iph = (const struct iphdr *)skb->data; 520 const int type = icmp_hdr(skb)->type; 521 const int code = icmp_hdr(skb)->code; 522 struct ip_tunnel *t; 523 int err; 524 525 switch (type) { 526 default: 527 case ICMP_PARAMETERPROB: 528 return 0; 529 530 case ICMP_DEST_UNREACH: 531 switch (code) { 532 case ICMP_SR_FAILED: 533 /* Impossible event. */ 534 return 0; 535 default: 536 /* All others are translated to HOST_UNREACH. 537 rfc2003 contains "deep thoughts" about NET_UNREACH, 538 I believe they are just ether pollution. --ANK 539 */ 540 break; 541 } 542 break; 543 case ICMP_TIME_EXCEEDED: 544 if (code != ICMP_EXC_TTL) 545 return 0; 546 break; 547 case ICMP_REDIRECT: 548 break; 549 } 550 551 err = -ENOENT; 552 553 t = ipip6_tunnel_lookup(dev_net(skb->dev), 554 skb->dev, 555 iph->daddr, 556 iph->saddr); 557 if (t == NULL) 558 goto out; 559 560 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 561 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 562 t->dev->ifindex, 0, IPPROTO_IPV6, 0); 563 err = 0; 564 goto out; 565 } 566 if (type == ICMP_REDIRECT) { 567 ipv4_redirect(skb, dev_net(skb->dev), t->dev->ifindex, 0, 568 IPPROTO_IPV6, 0); 569 err = 0; 570 goto out; 571 } 572 573 if (t->parms.iph.daddr == 0) 574 goto out; 575 576 err = 0; 577 if (!ipip6_err_gen_icmpv6_unreach(skb)) 578 goto out; 579 580 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 581 goto out; 582 583 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 584 t->err_count++; 585 else 586 t->err_count = 1; 587 t->err_time = jiffies; 588 out: 589 return err; 590 } 591 592 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, 593 const struct in6_addr *v6addr) 594 { 595 __be32 v4embed = 0; 596 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) 597 return true; 598 return false; 599 } 600 601 /* Checks if an address matches an address on the tunnel interface. 602 * Used to detect the NAT of proto 41 packets and let them pass spoofing test. 603 * Long story: 604 * This function is called after we considered the packet as spoofed 605 * in is_spoofed_6rd. 606 * We may have a router that is doing NAT for proto 41 packets 607 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb 608 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd 609 * function will return true, dropping the packet. 610 * But, we can still check if is spoofed against the IP 611 * addresses associated with the interface. 612 */ 613 static bool only_dnatted(const struct ip_tunnel *tunnel, 614 const struct in6_addr *v6dst) 615 { 616 int prefix_len; 617 618 #ifdef CONFIG_IPV6_SIT_6RD 619 prefix_len = tunnel->ip6rd.prefixlen + 32 620 - tunnel->ip6rd.relay_prefixlen; 621 #else 622 prefix_len = 48; 623 #endif 624 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev); 625 } 626 627 /* Returns true if a packet is spoofed */ 628 static bool packet_is_spoofed(struct sk_buff *skb, 629 const struct iphdr *iph, 630 struct ip_tunnel *tunnel) 631 { 632 const struct ipv6hdr *ipv6h; 633 634 if (tunnel->dev->priv_flags & IFF_ISATAP) { 635 if (!isatap_chksrc(skb, iph, tunnel)) 636 return true; 637 638 return false; 639 } 640 641 if (tunnel->dev->flags & IFF_POINTOPOINT) 642 return false; 643 644 ipv6h = ipv6_hdr(skb); 645 646 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) { 647 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 648 &iph->saddr, &ipv6h->saddr, 649 &iph->daddr, &ipv6h->daddr); 650 return true; 651 } 652 653 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr))) 654 return false; 655 656 if (only_dnatted(tunnel, &ipv6h->daddr)) 657 return false; 658 659 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 660 &iph->saddr, &ipv6h->saddr, 661 &iph->daddr, &ipv6h->daddr); 662 return true; 663 } 664 665 static int ipip6_rcv(struct sk_buff *skb) 666 { 667 const struct iphdr *iph = ip_hdr(skb); 668 struct ip_tunnel *tunnel; 669 int err; 670 671 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 672 iph->saddr, iph->daddr); 673 if (tunnel != NULL) { 674 struct pcpu_tstats *tstats; 675 676 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && 677 tunnel->parms.iph.protocol != 0) 678 goto out; 679 680 skb->mac_header = skb->network_header; 681 skb_reset_network_header(skb); 682 IPCB(skb)->flags = 0; 683 skb->protocol = htons(ETH_P_IPV6); 684 685 if (packet_is_spoofed(skb, iph, tunnel)) { 686 tunnel->dev->stats.rx_errors++; 687 goto out; 688 } 689 690 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net); 691 692 err = IP_ECN_decapsulate(iph, skb); 693 if (unlikely(err)) { 694 if (log_ecn_error) 695 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 696 &iph->saddr, iph->tos); 697 if (err > 1) { 698 ++tunnel->dev->stats.rx_frame_errors; 699 ++tunnel->dev->stats.rx_errors; 700 goto out; 701 } 702 } 703 704 tstats = this_cpu_ptr(tunnel->dev->tstats); 705 tstats->rx_packets++; 706 tstats->rx_bytes += skb->len; 707 708 netif_rx(skb); 709 710 return 0; 711 } 712 713 /* no tunnel matched, let upstream know, ipsec may handle it */ 714 return 1; 715 out: 716 kfree_skb(skb); 717 return 0; 718 } 719 720 static const struct tnl_ptk_info tpi = { 721 /* no tunnel info required for ipip. */ 722 .proto = htons(ETH_P_IP), 723 }; 724 725 static int ipip_rcv(struct sk_buff *skb) 726 { 727 const struct iphdr *iph; 728 struct ip_tunnel *tunnel; 729 730 iph = ip_hdr(skb); 731 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 732 iph->saddr, iph->daddr); 733 if (tunnel != NULL) { 734 if (tunnel->parms.iph.protocol != IPPROTO_IPIP && 735 tunnel->parms.iph.protocol != 0) 736 goto drop; 737 738 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 739 goto drop; 740 if (iptunnel_pull_header(skb, 0, tpi.proto)) 741 goto drop; 742 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); 743 } 744 745 return 1; 746 747 drop: 748 kfree_skb(skb); 749 return 0; 750 } 751 752 /* 753 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function 754 * stores the embedded IPv4 address in v4dst and returns true. 755 */ 756 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 757 __be32 *v4dst) 758 { 759 #ifdef CONFIG_IPV6_SIT_6RD 760 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 761 tunnel->ip6rd.prefixlen)) { 762 unsigned int pbw0, pbi0; 763 int pbi1; 764 u32 d; 765 766 pbw0 = tunnel->ip6rd.prefixlen >> 5; 767 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 768 769 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 770 tunnel->ip6rd.relay_prefixlen; 771 772 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 773 if (pbi1 > 0) 774 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 775 (32 - pbi1); 776 777 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); 778 return true; 779 } 780 #else 781 if (v6dst->s6_addr16[0] == htons(0x2002)) { 782 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 783 memcpy(v4dst, &v6dst->s6_addr16[1], 4); 784 return true; 785 } 786 #endif 787 return false; 788 } 789 790 static inline __be32 try_6rd(struct ip_tunnel *tunnel, 791 const struct in6_addr *v6dst) 792 { 793 __be32 dst = 0; 794 check_6rd(tunnel, v6dst, &dst); 795 return dst; 796 } 797 798 /* 799 * This function assumes it is being called from dev_queue_xmit() 800 * and that skb is filled properly by that function. 801 */ 802 803 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 804 struct net_device *dev) 805 { 806 struct ip_tunnel *tunnel = netdev_priv(dev); 807 const struct iphdr *tiph = &tunnel->parms.iph; 808 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 809 u8 tos = tunnel->parms.iph.tos; 810 __be16 df = tiph->frag_off; 811 struct rtable *rt; /* Route to the other host */ 812 struct net_device *tdev; /* Device to other host */ 813 unsigned int max_headroom; /* The extra header space needed */ 814 __be32 dst = tiph->daddr; 815 struct flowi4 fl4; 816 int mtu; 817 const struct in6_addr *addr6; 818 int addr_type; 819 u8 ttl; 820 int err; 821 822 if (skb->protocol != htons(ETH_P_IPV6)) 823 goto tx_error; 824 825 if (tos == 1) 826 tos = ipv6_get_dsfield(iph6); 827 828 /* ISATAP (RFC4214) - must come before 6to4 */ 829 if (dev->priv_flags & IFF_ISATAP) { 830 struct neighbour *neigh = NULL; 831 bool do_tx_error = false; 832 833 if (skb_dst(skb)) 834 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 835 836 if (neigh == NULL) { 837 net_dbg_ratelimited("nexthop == NULL\n"); 838 goto tx_error; 839 } 840 841 addr6 = (const struct in6_addr *)&neigh->primary_key; 842 addr_type = ipv6_addr_type(addr6); 843 844 if ((addr_type & IPV6_ADDR_UNICAST) && 845 ipv6_addr_is_isatap(addr6)) 846 dst = addr6->s6_addr32[3]; 847 else 848 do_tx_error = true; 849 850 neigh_release(neigh); 851 if (do_tx_error) 852 goto tx_error; 853 } 854 855 if (!dst) 856 dst = try_6rd(tunnel, &iph6->daddr); 857 858 if (!dst) { 859 struct neighbour *neigh = NULL; 860 bool do_tx_error = false; 861 862 if (skb_dst(skb)) 863 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 864 865 if (neigh == NULL) { 866 net_dbg_ratelimited("nexthop == NULL\n"); 867 goto tx_error; 868 } 869 870 addr6 = (const struct in6_addr *)&neigh->primary_key; 871 addr_type = ipv6_addr_type(addr6); 872 873 if (addr_type == IPV6_ADDR_ANY) { 874 addr6 = &ipv6_hdr(skb)->daddr; 875 addr_type = ipv6_addr_type(addr6); 876 } 877 878 if ((addr_type & IPV6_ADDR_COMPATv4) != 0) 879 dst = addr6->s6_addr32[3]; 880 else 881 do_tx_error = true; 882 883 neigh_release(neigh); 884 if (do_tx_error) 885 goto tx_error; 886 } 887 888 rt = ip_route_output_ports(tunnel->net, &fl4, NULL, 889 dst, tiph->saddr, 890 0, 0, 891 IPPROTO_IPV6, RT_TOS(tos), 892 tunnel->parms.link); 893 if (IS_ERR(rt)) { 894 dev->stats.tx_carrier_errors++; 895 goto tx_error_icmp; 896 } 897 if (rt->rt_type != RTN_UNICAST) { 898 ip_rt_put(rt); 899 dev->stats.tx_carrier_errors++; 900 goto tx_error_icmp; 901 } 902 tdev = rt->dst.dev; 903 904 if (tdev == dev) { 905 ip_rt_put(rt); 906 dev->stats.collisions++; 907 goto tx_error; 908 } 909 910 if (df) { 911 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 912 913 if (mtu < 68) { 914 dev->stats.collisions++; 915 ip_rt_put(rt); 916 goto tx_error; 917 } 918 919 if (mtu < IPV6_MIN_MTU) { 920 mtu = IPV6_MIN_MTU; 921 df = 0; 922 } 923 924 if (tunnel->parms.iph.daddr && skb_dst(skb)) 925 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 926 927 if (skb->len > mtu) { 928 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 929 ip_rt_put(rt); 930 goto tx_error; 931 } 932 } 933 934 if (tunnel->err_count > 0) { 935 if (time_before(jiffies, 936 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 937 tunnel->err_count--; 938 dst_link_failure(skb); 939 } else 940 tunnel->err_count = 0; 941 } 942 943 /* 944 * Okay, now see if we can stuff it in the buffer as-is. 945 */ 946 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 947 948 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 949 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 950 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 951 if (!new_skb) { 952 ip_rt_put(rt); 953 dev->stats.tx_dropped++; 954 kfree_skb(skb); 955 return NETDEV_TX_OK; 956 } 957 if (skb->sk) 958 skb_set_owner_w(new_skb, skb->sk); 959 dev_kfree_skb(skb); 960 skb = new_skb; 961 iph6 = ipv6_hdr(skb); 962 } 963 ttl = tiph->ttl; 964 if (ttl == 0) 965 ttl = iph6->hop_limit; 966 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 967 968 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT); 969 if (IS_ERR(skb)) 970 goto out; 971 972 err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos, 973 ttl, df, !net_eq(tunnel->net, dev_net(dev))); 974 iptunnel_xmit_stats(err, &dev->stats, dev->tstats); 975 return NETDEV_TX_OK; 976 977 tx_error_icmp: 978 dst_link_failure(skb); 979 tx_error: 980 kfree_skb(skb); 981 out: 982 dev->stats.tx_errors++; 983 return NETDEV_TX_OK; 984 } 985 986 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 987 { 988 struct ip_tunnel *tunnel = netdev_priv(dev); 989 const struct iphdr *tiph = &tunnel->parms.iph; 990 991 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP); 992 if (IS_ERR(skb)) 993 goto out; 994 995 ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP); 996 return NETDEV_TX_OK; 997 out: 998 dev->stats.tx_errors++; 999 return NETDEV_TX_OK; 1000 } 1001 1002 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, 1003 struct net_device *dev) 1004 { 1005 switch (skb->protocol) { 1006 case htons(ETH_P_IP): 1007 ipip_tunnel_xmit(skb, dev); 1008 break; 1009 case htons(ETH_P_IPV6): 1010 ipip6_tunnel_xmit(skb, dev); 1011 break; 1012 default: 1013 goto tx_err; 1014 } 1015 1016 return NETDEV_TX_OK; 1017 1018 tx_err: 1019 dev->stats.tx_errors++; 1020 kfree_skb(skb); 1021 return NETDEV_TX_OK; 1022 1023 } 1024 1025 static void ipip6_tunnel_bind_dev(struct net_device *dev) 1026 { 1027 struct net_device *tdev = NULL; 1028 struct ip_tunnel *tunnel; 1029 const struct iphdr *iph; 1030 struct flowi4 fl4; 1031 1032 tunnel = netdev_priv(dev); 1033 iph = &tunnel->parms.iph; 1034 1035 if (iph->daddr) { 1036 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, 1037 NULL, 1038 iph->daddr, iph->saddr, 1039 0, 0, 1040 IPPROTO_IPV6, 1041 RT_TOS(iph->tos), 1042 tunnel->parms.link); 1043 1044 if (!IS_ERR(rt)) { 1045 tdev = rt->dst.dev; 1046 ip_rt_put(rt); 1047 } 1048 dev->flags |= IFF_POINTOPOINT; 1049 } 1050 1051 if (!tdev && tunnel->parms.link) 1052 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 1053 1054 if (tdev) { 1055 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 1056 dev->mtu = tdev->mtu - sizeof(struct iphdr); 1057 if (dev->mtu < IPV6_MIN_MTU) 1058 dev->mtu = IPV6_MIN_MTU; 1059 } 1060 dev->iflink = tunnel->parms.link; 1061 } 1062 1063 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p) 1064 { 1065 struct net *net = t->net; 1066 struct sit_net *sitn = net_generic(net, sit_net_id); 1067 1068 ipip6_tunnel_unlink(sitn, t); 1069 synchronize_net(); 1070 t->parms.iph.saddr = p->iph.saddr; 1071 t->parms.iph.daddr = p->iph.daddr; 1072 memcpy(t->dev->dev_addr, &p->iph.saddr, 4); 1073 memcpy(t->dev->broadcast, &p->iph.daddr, 4); 1074 ipip6_tunnel_link(sitn, t); 1075 t->parms.iph.ttl = p->iph.ttl; 1076 t->parms.iph.tos = p->iph.tos; 1077 if (t->parms.link != p->link) { 1078 t->parms.link = p->link; 1079 ipip6_tunnel_bind_dev(t->dev); 1080 } 1081 netdev_state_change(t->dev); 1082 } 1083 1084 #ifdef CONFIG_IPV6_SIT_6RD 1085 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, 1086 struct ip_tunnel_6rd *ip6rd) 1087 { 1088 struct in6_addr prefix; 1089 __be32 relay_prefix; 1090 1091 if (ip6rd->relay_prefixlen > 32 || 1092 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) 1093 return -EINVAL; 1094 1095 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); 1096 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) 1097 return -EINVAL; 1098 if (ip6rd->relay_prefixlen) 1099 relay_prefix = ip6rd->relay_prefix & 1100 htonl(0xffffffffUL << 1101 (32 - ip6rd->relay_prefixlen)); 1102 else 1103 relay_prefix = 0; 1104 if (relay_prefix != ip6rd->relay_prefix) 1105 return -EINVAL; 1106 1107 t->ip6rd.prefix = prefix; 1108 t->ip6rd.relay_prefix = relay_prefix; 1109 t->ip6rd.prefixlen = ip6rd->prefixlen; 1110 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; 1111 netdev_state_change(t->dev); 1112 return 0; 1113 } 1114 #endif 1115 1116 static int 1117 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 1118 { 1119 int err = 0; 1120 struct ip_tunnel_parm p; 1121 struct ip_tunnel_prl prl; 1122 struct ip_tunnel *t; 1123 struct net *net = dev_net(dev); 1124 struct sit_net *sitn = net_generic(net, sit_net_id); 1125 #ifdef CONFIG_IPV6_SIT_6RD 1126 struct ip_tunnel_6rd ip6rd; 1127 #endif 1128 1129 switch (cmd) { 1130 case SIOCGETTUNNEL: 1131 #ifdef CONFIG_IPV6_SIT_6RD 1132 case SIOCGET6RD: 1133 #endif 1134 t = NULL; 1135 if (dev == sitn->fb_tunnel_dev) { 1136 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 1137 err = -EFAULT; 1138 break; 1139 } 1140 t = ipip6_tunnel_locate(net, &p, 0); 1141 } 1142 if (t == NULL) 1143 t = netdev_priv(dev); 1144 1145 err = -EFAULT; 1146 if (cmd == SIOCGETTUNNEL) { 1147 memcpy(&p, &t->parms, sizeof(p)); 1148 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 1149 sizeof(p))) 1150 goto done; 1151 #ifdef CONFIG_IPV6_SIT_6RD 1152 } else { 1153 ip6rd.prefix = t->ip6rd.prefix; 1154 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 1155 ip6rd.prefixlen = t->ip6rd.prefixlen; 1156 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 1157 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 1158 sizeof(ip6rd))) 1159 goto done; 1160 #endif 1161 } 1162 err = 0; 1163 break; 1164 1165 case SIOCADDTUNNEL: 1166 case SIOCCHGTUNNEL: 1167 err = -EPERM; 1168 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1169 goto done; 1170 1171 err = -EFAULT; 1172 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1173 goto done; 1174 1175 err = -EINVAL; 1176 if (p.iph.protocol != IPPROTO_IPV6 && 1177 p.iph.protocol != IPPROTO_IPIP && 1178 p.iph.protocol != 0) 1179 goto done; 1180 if (p.iph.version != 4 || 1181 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 1182 goto done; 1183 if (p.iph.ttl) 1184 p.iph.frag_off |= htons(IP_DF); 1185 1186 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 1187 1188 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 1189 if (t != NULL) { 1190 if (t->dev != dev) { 1191 err = -EEXIST; 1192 break; 1193 } 1194 } else { 1195 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 1196 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 1197 err = -EINVAL; 1198 break; 1199 } 1200 t = netdev_priv(dev); 1201 } 1202 1203 ipip6_tunnel_update(t, &p); 1204 } 1205 1206 if (t) { 1207 err = 0; 1208 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 1209 err = -EFAULT; 1210 } else 1211 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1212 break; 1213 1214 case SIOCDELTUNNEL: 1215 err = -EPERM; 1216 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1217 goto done; 1218 1219 if (dev == sitn->fb_tunnel_dev) { 1220 err = -EFAULT; 1221 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1222 goto done; 1223 err = -ENOENT; 1224 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 1225 goto done; 1226 err = -EPERM; 1227 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1228 goto done; 1229 dev = t->dev; 1230 } 1231 unregister_netdevice(dev); 1232 err = 0; 1233 break; 1234 1235 case SIOCGETPRL: 1236 err = -EINVAL; 1237 if (dev == sitn->fb_tunnel_dev) 1238 goto done; 1239 err = -ENOENT; 1240 if (!(t = netdev_priv(dev))) 1241 goto done; 1242 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1243 break; 1244 1245 case SIOCADDPRL: 1246 case SIOCDELPRL: 1247 case SIOCCHGPRL: 1248 err = -EPERM; 1249 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1250 goto done; 1251 err = -EINVAL; 1252 if (dev == sitn->fb_tunnel_dev) 1253 goto done; 1254 err = -EFAULT; 1255 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1256 goto done; 1257 err = -ENOENT; 1258 if (!(t = netdev_priv(dev))) 1259 goto done; 1260 1261 switch (cmd) { 1262 case SIOCDELPRL: 1263 err = ipip6_tunnel_del_prl(t, &prl); 1264 break; 1265 case SIOCADDPRL: 1266 case SIOCCHGPRL: 1267 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1268 break; 1269 } 1270 netdev_state_change(dev); 1271 break; 1272 1273 #ifdef CONFIG_IPV6_SIT_6RD 1274 case SIOCADD6RD: 1275 case SIOCCHG6RD: 1276 case SIOCDEL6RD: 1277 err = -EPERM; 1278 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1279 goto done; 1280 1281 err = -EFAULT; 1282 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1283 sizeof(ip6rd))) 1284 goto done; 1285 1286 t = netdev_priv(dev); 1287 1288 if (cmd != SIOCDEL6RD) { 1289 err = ipip6_tunnel_update_6rd(t, &ip6rd); 1290 if (err < 0) 1291 goto done; 1292 } else 1293 ipip6_tunnel_clone_6rd(dev, sitn); 1294 1295 err = 0; 1296 break; 1297 #endif 1298 1299 default: 1300 err = -EINVAL; 1301 } 1302 1303 done: 1304 return err; 1305 } 1306 1307 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1308 { 1309 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1310 return -EINVAL; 1311 dev->mtu = new_mtu; 1312 return 0; 1313 } 1314 1315 static const struct net_device_ops ipip6_netdev_ops = { 1316 .ndo_uninit = ipip6_tunnel_uninit, 1317 .ndo_start_xmit = sit_tunnel_xmit, 1318 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1319 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1320 .ndo_get_stats64 = ip_tunnel_get_stats64, 1321 }; 1322 1323 static void ipip6_dev_free(struct net_device *dev) 1324 { 1325 free_percpu(dev->tstats); 1326 free_netdev(dev); 1327 } 1328 1329 #define SIT_FEATURES (NETIF_F_SG | \ 1330 NETIF_F_FRAGLIST | \ 1331 NETIF_F_HIGHDMA | \ 1332 NETIF_F_GSO_SOFTWARE | \ 1333 NETIF_F_HW_CSUM) 1334 1335 static void ipip6_tunnel_setup(struct net_device *dev) 1336 { 1337 dev->netdev_ops = &ipip6_netdev_ops; 1338 dev->destructor = ipip6_dev_free; 1339 1340 dev->type = ARPHRD_SIT; 1341 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1342 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1343 dev->flags = IFF_NOARP; 1344 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1345 dev->iflink = 0; 1346 dev->addr_len = 4; 1347 dev->features |= NETIF_F_LLTX; 1348 dev->features |= SIT_FEATURES; 1349 dev->hw_features |= SIT_FEATURES; 1350 } 1351 1352 static int ipip6_tunnel_init(struct net_device *dev) 1353 { 1354 struct ip_tunnel *tunnel = netdev_priv(dev); 1355 int i; 1356 1357 tunnel->dev = dev; 1358 tunnel->net = dev_net(dev); 1359 1360 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1361 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1362 1363 ipip6_tunnel_bind_dev(dev); 1364 dev->tstats = alloc_percpu(struct pcpu_tstats); 1365 if (!dev->tstats) 1366 return -ENOMEM; 1367 1368 for_each_possible_cpu(i) { 1369 struct pcpu_tstats *ipip6_tunnel_stats; 1370 ipip6_tunnel_stats = per_cpu_ptr(dev->tstats, i); 1371 u64_stats_init(&ipip6_tunnel_stats->syncp); 1372 } 1373 1374 return 0; 1375 } 1376 1377 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1378 { 1379 struct ip_tunnel *tunnel = netdev_priv(dev); 1380 struct iphdr *iph = &tunnel->parms.iph; 1381 struct net *net = dev_net(dev); 1382 struct sit_net *sitn = net_generic(net, sit_net_id); 1383 int i; 1384 1385 tunnel->dev = dev; 1386 tunnel->net = dev_net(dev); 1387 strcpy(tunnel->parms.name, dev->name); 1388 1389 iph->version = 4; 1390 iph->protocol = IPPROTO_IPV6; 1391 iph->ihl = 5; 1392 iph->ttl = 64; 1393 1394 dev->tstats = alloc_percpu(struct pcpu_tstats); 1395 if (!dev->tstats) 1396 return -ENOMEM; 1397 1398 for_each_possible_cpu(i) { 1399 struct pcpu_tstats *ipip6_fb_stats; 1400 ipip6_fb_stats = per_cpu_ptr(dev->tstats, i); 1401 u64_stats_init(&ipip6_fb_stats->syncp); 1402 } 1403 1404 dev_hold(dev); 1405 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1406 return 0; 1407 } 1408 1409 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[]) 1410 { 1411 u8 proto; 1412 1413 if (!data || !data[IFLA_IPTUN_PROTO]) 1414 return 0; 1415 1416 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1417 if (proto != IPPROTO_IPV6 && 1418 proto != IPPROTO_IPIP && 1419 proto != 0) 1420 return -EINVAL; 1421 1422 return 0; 1423 } 1424 1425 static void ipip6_netlink_parms(struct nlattr *data[], 1426 struct ip_tunnel_parm *parms) 1427 { 1428 memset(parms, 0, sizeof(*parms)); 1429 1430 parms->iph.version = 4; 1431 parms->iph.protocol = IPPROTO_IPV6; 1432 parms->iph.ihl = 5; 1433 parms->iph.ttl = 64; 1434 1435 if (!data) 1436 return; 1437 1438 if (data[IFLA_IPTUN_LINK]) 1439 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1440 1441 if (data[IFLA_IPTUN_LOCAL]) 1442 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); 1443 1444 if (data[IFLA_IPTUN_REMOTE]) 1445 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); 1446 1447 if (data[IFLA_IPTUN_TTL]) { 1448 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); 1449 if (parms->iph.ttl) 1450 parms->iph.frag_off = htons(IP_DF); 1451 } 1452 1453 if (data[IFLA_IPTUN_TOS]) 1454 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); 1455 1456 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) 1457 parms->iph.frag_off = htons(IP_DF); 1458 1459 if (data[IFLA_IPTUN_FLAGS]) 1460 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); 1461 1462 if (data[IFLA_IPTUN_PROTO]) 1463 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1464 1465 } 1466 1467 #ifdef CONFIG_IPV6_SIT_6RD 1468 /* This function returns true when 6RD attributes are present in the nl msg */ 1469 static bool ipip6_netlink_6rd_parms(struct nlattr *data[], 1470 struct ip_tunnel_6rd *ip6rd) 1471 { 1472 bool ret = false; 1473 memset(ip6rd, 0, sizeof(*ip6rd)); 1474 1475 if (!data) 1476 return ret; 1477 1478 if (data[IFLA_IPTUN_6RD_PREFIX]) { 1479 ret = true; 1480 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX], 1481 sizeof(struct in6_addr)); 1482 } 1483 1484 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { 1485 ret = true; 1486 ip6rd->relay_prefix = 1487 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); 1488 } 1489 1490 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { 1491 ret = true; 1492 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); 1493 } 1494 1495 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { 1496 ret = true; 1497 ip6rd->relay_prefixlen = 1498 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); 1499 } 1500 1501 return ret; 1502 } 1503 #endif 1504 1505 static int ipip6_newlink(struct net *src_net, struct net_device *dev, 1506 struct nlattr *tb[], struct nlattr *data[]) 1507 { 1508 struct net *net = dev_net(dev); 1509 struct ip_tunnel *nt; 1510 #ifdef CONFIG_IPV6_SIT_6RD 1511 struct ip_tunnel_6rd ip6rd; 1512 #endif 1513 int err; 1514 1515 nt = netdev_priv(dev); 1516 ipip6_netlink_parms(data, &nt->parms); 1517 1518 if (ipip6_tunnel_locate(net, &nt->parms, 0)) 1519 return -EEXIST; 1520 1521 err = ipip6_tunnel_create(dev); 1522 if (err < 0) 1523 return err; 1524 1525 #ifdef CONFIG_IPV6_SIT_6RD 1526 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1527 err = ipip6_tunnel_update_6rd(nt, &ip6rd); 1528 #endif 1529 1530 return err; 1531 } 1532 1533 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], 1534 struct nlattr *data[]) 1535 { 1536 struct ip_tunnel *t = netdev_priv(dev); 1537 struct ip_tunnel_parm p; 1538 struct net *net = t->net; 1539 struct sit_net *sitn = net_generic(net, sit_net_id); 1540 #ifdef CONFIG_IPV6_SIT_6RD 1541 struct ip_tunnel_6rd ip6rd; 1542 #endif 1543 1544 if (dev == sitn->fb_tunnel_dev) 1545 return -EINVAL; 1546 1547 ipip6_netlink_parms(data, &p); 1548 1549 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || 1550 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) 1551 return -EINVAL; 1552 1553 t = ipip6_tunnel_locate(net, &p, 0); 1554 1555 if (t) { 1556 if (t->dev != dev) 1557 return -EEXIST; 1558 } else 1559 t = netdev_priv(dev); 1560 1561 ipip6_tunnel_update(t, &p); 1562 1563 #ifdef CONFIG_IPV6_SIT_6RD 1564 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1565 return ipip6_tunnel_update_6rd(t, &ip6rd); 1566 #endif 1567 1568 return 0; 1569 } 1570 1571 static size_t ipip6_get_size(const struct net_device *dev) 1572 { 1573 return 1574 /* IFLA_IPTUN_LINK */ 1575 nla_total_size(4) + 1576 /* IFLA_IPTUN_LOCAL */ 1577 nla_total_size(4) + 1578 /* IFLA_IPTUN_REMOTE */ 1579 nla_total_size(4) + 1580 /* IFLA_IPTUN_TTL */ 1581 nla_total_size(1) + 1582 /* IFLA_IPTUN_TOS */ 1583 nla_total_size(1) + 1584 /* IFLA_IPTUN_PMTUDISC */ 1585 nla_total_size(1) + 1586 /* IFLA_IPTUN_FLAGS */ 1587 nla_total_size(2) + 1588 /* IFLA_IPTUN_PROTO */ 1589 nla_total_size(1) + 1590 #ifdef CONFIG_IPV6_SIT_6RD 1591 /* IFLA_IPTUN_6RD_PREFIX */ 1592 nla_total_size(sizeof(struct in6_addr)) + 1593 /* IFLA_IPTUN_6RD_RELAY_PREFIX */ 1594 nla_total_size(4) + 1595 /* IFLA_IPTUN_6RD_PREFIXLEN */ 1596 nla_total_size(2) + 1597 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ 1598 nla_total_size(2) + 1599 #endif 1600 0; 1601 } 1602 1603 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1604 { 1605 struct ip_tunnel *tunnel = netdev_priv(dev); 1606 struct ip_tunnel_parm *parm = &tunnel->parms; 1607 1608 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1609 nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || 1610 nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || 1611 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || 1612 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || 1613 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, 1614 !!(parm->iph.frag_off & htons(IP_DF))) || 1615 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || 1616 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags)) 1617 goto nla_put_failure; 1618 1619 #ifdef CONFIG_IPV6_SIT_6RD 1620 if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr), 1621 &tunnel->ip6rd.prefix) || 1622 nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, 1623 tunnel->ip6rd.relay_prefix) || 1624 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, 1625 tunnel->ip6rd.prefixlen) || 1626 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, 1627 tunnel->ip6rd.relay_prefixlen)) 1628 goto nla_put_failure; 1629 #endif 1630 1631 return 0; 1632 1633 nla_put_failure: 1634 return -EMSGSIZE; 1635 } 1636 1637 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { 1638 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1639 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, 1640 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, 1641 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1642 [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, 1643 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, 1644 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, 1645 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1646 #ifdef CONFIG_IPV6_SIT_6RD 1647 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, 1648 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, 1649 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, 1650 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, 1651 #endif 1652 }; 1653 1654 static void ipip6_dellink(struct net_device *dev, struct list_head *head) 1655 { 1656 struct net *net = dev_net(dev); 1657 struct sit_net *sitn = net_generic(net, sit_net_id); 1658 1659 if (dev != sitn->fb_tunnel_dev) 1660 unregister_netdevice_queue(dev, head); 1661 } 1662 1663 static struct rtnl_link_ops sit_link_ops __read_mostly = { 1664 .kind = "sit", 1665 .maxtype = IFLA_IPTUN_MAX, 1666 .policy = ipip6_policy, 1667 .priv_size = sizeof(struct ip_tunnel), 1668 .setup = ipip6_tunnel_setup, 1669 .validate = ipip6_validate, 1670 .newlink = ipip6_newlink, 1671 .changelink = ipip6_changelink, 1672 .get_size = ipip6_get_size, 1673 .fill_info = ipip6_fill_info, 1674 .dellink = ipip6_dellink, 1675 }; 1676 1677 static struct xfrm_tunnel sit_handler __read_mostly = { 1678 .handler = ipip6_rcv, 1679 .err_handler = ipip6_err, 1680 .priority = 1, 1681 }; 1682 1683 static struct xfrm_tunnel ipip_handler __read_mostly = { 1684 .handler = ipip_rcv, 1685 .err_handler = ipip6_err, 1686 .priority = 2, 1687 }; 1688 1689 static void __net_exit sit_destroy_tunnels(struct net *net, 1690 struct list_head *head) 1691 { 1692 struct sit_net *sitn = net_generic(net, sit_net_id); 1693 struct net_device *dev, *aux; 1694 int prio; 1695 1696 for_each_netdev_safe(net, dev, aux) 1697 if (dev->rtnl_link_ops == &sit_link_ops) 1698 unregister_netdevice_queue(dev, head); 1699 1700 for (prio = 1; prio < 4; prio++) { 1701 int h; 1702 for (h = 0; h < HASH_SIZE; h++) { 1703 struct ip_tunnel *t; 1704 1705 t = rtnl_dereference(sitn->tunnels[prio][h]); 1706 while (t != NULL) { 1707 /* If dev is in the same netns, it has already 1708 * been added to the list by the previous loop. 1709 */ 1710 if (!net_eq(dev_net(t->dev), net)) 1711 unregister_netdevice_queue(t->dev, 1712 head); 1713 t = rtnl_dereference(t->next); 1714 } 1715 } 1716 } 1717 } 1718 1719 static int __net_init sit_init_net(struct net *net) 1720 { 1721 struct sit_net *sitn = net_generic(net, sit_net_id); 1722 struct ip_tunnel *t; 1723 int err; 1724 1725 sitn->tunnels[0] = sitn->tunnels_wc; 1726 sitn->tunnels[1] = sitn->tunnels_l; 1727 sitn->tunnels[2] = sitn->tunnels_r; 1728 sitn->tunnels[3] = sitn->tunnels_r_l; 1729 1730 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1731 ipip6_tunnel_setup); 1732 if (!sitn->fb_tunnel_dev) { 1733 err = -ENOMEM; 1734 goto err_alloc_dev; 1735 } 1736 dev_net_set(sitn->fb_tunnel_dev, net); 1737 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; 1738 /* FB netdevice is special: we have one, and only one per netns. 1739 * Allowing to move it to another netns is clearly unsafe. 1740 */ 1741 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1742 1743 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1744 if (err) 1745 goto err_dev_free; 1746 1747 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1748 1749 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1750 goto err_reg_dev; 1751 1752 t = netdev_priv(sitn->fb_tunnel_dev); 1753 1754 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1755 return 0; 1756 1757 err_reg_dev: 1758 dev_put(sitn->fb_tunnel_dev); 1759 err_dev_free: 1760 ipip6_dev_free(sitn->fb_tunnel_dev); 1761 err_alloc_dev: 1762 return err; 1763 } 1764 1765 static void __net_exit sit_exit_net(struct net *net) 1766 { 1767 LIST_HEAD(list); 1768 1769 rtnl_lock(); 1770 sit_destroy_tunnels(net, &list); 1771 unregister_netdevice_many(&list); 1772 rtnl_unlock(); 1773 } 1774 1775 static struct pernet_operations sit_net_ops = { 1776 .init = sit_init_net, 1777 .exit = sit_exit_net, 1778 .id = &sit_net_id, 1779 .size = sizeof(struct sit_net), 1780 }; 1781 1782 static void __exit sit_cleanup(void) 1783 { 1784 rtnl_link_unregister(&sit_link_ops); 1785 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1786 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1787 1788 unregister_pernet_device(&sit_net_ops); 1789 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1790 } 1791 1792 static int __init sit_init(void) 1793 { 1794 int err; 1795 1796 pr_info("IPv6 over IPv4 tunneling driver\n"); 1797 1798 err = register_pernet_device(&sit_net_ops); 1799 if (err < 0) 1800 return err; 1801 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1802 if (err < 0) { 1803 pr_info("%s: can't register ip6ip4\n", __func__); 1804 goto xfrm_tunnel_failed; 1805 } 1806 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 1807 if (err < 0) { 1808 pr_info("%s: can't register ip4ip4\n", __func__); 1809 goto xfrm_tunnel4_failed; 1810 } 1811 err = rtnl_link_register(&sit_link_ops); 1812 if (err < 0) 1813 goto rtnl_link_failed; 1814 1815 out: 1816 return err; 1817 1818 rtnl_link_failed: 1819 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1820 xfrm_tunnel4_failed: 1821 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1822 xfrm_tunnel_failed: 1823 unregister_pernet_device(&sit_net_ops); 1824 goto out; 1825 } 1826 1827 module_init(sit_init); 1828 module_exit(sit_cleanup); 1829 MODULE_LICENSE("GPL"); 1830 MODULE_ALIAS_NETDEV("sit0"); 1831