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 != 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, NET_NAME_UNKNOWN, 254 ipip6_tunnel_setup); 255 if (dev == NULL) 256 return NULL; 257 258 dev_net_set(dev, net); 259 260 nt = netdev_priv(dev); 261 262 nt->parms = *parms; 263 if (ipip6_tunnel_create(dev) < 0) 264 goto failed_free; 265 266 return nt; 267 268 failed_free: 269 ipip6_dev_free(dev); 270 failed: 271 return NULL; 272 } 273 274 #define for_each_prl_rcu(start) \ 275 for (prl = rcu_dereference(start); \ 276 prl; \ 277 prl = rcu_dereference(prl->next)) 278 279 static struct ip_tunnel_prl_entry * 280 __ipip6_tunnel_locate_prl(struct ip_tunnel *t, __be32 addr) 281 { 282 struct ip_tunnel_prl_entry *prl; 283 284 for_each_prl_rcu(t->prl) 285 if (prl->addr == addr) 286 break; 287 return prl; 288 289 } 290 291 static int ipip6_tunnel_get_prl(struct ip_tunnel *t, 292 struct ip_tunnel_prl __user *a) 293 { 294 struct ip_tunnel_prl kprl, *kp; 295 struct ip_tunnel_prl_entry *prl; 296 unsigned int cmax, c = 0, ca, len; 297 int ret = 0; 298 299 if (copy_from_user(&kprl, a, sizeof(kprl))) 300 return -EFAULT; 301 cmax = kprl.datalen / sizeof(kprl); 302 if (cmax > 1 && kprl.addr != htonl(INADDR_ANY)) 303 cmax = 1; 304 305 /* For simple GET or for root users, 306 * we try harder to allocate. 307 */ 308 kp = (cmax <= 1 || capable(CAP_NET_ADMIN)) ? 309 kcalloc(cmax, sizeof(*kp), GFP_KERNEL) : 310 NULL; 311 312 rcu_read_lock(); 313 314 ca = t->prl_count < cmax ? t->prl_count : cmax; 315 316 if (!kp) { 317 /* We don't try hard to allocate much memory for 318 * non-root users. 319 * For root users, retry allocating enough memory for 320 * the answer. 321 */ 322 kp = kcalloc(ca, sizeof(*kp), GFP_ATOMIC); 323 if (!kp) { 324 ret = -ENOMEM; 325 goto out; 326 } 327 } 328 329 c = 0; 330 for_each_prl_rcu(t->prl) { 331 if (c >= cmax) 332 break; 333 if (kprl.addr != htonl(INADDR_ANY) && prl->addr != kprl.addr) 334 continue; 335 kp[c].addr = prl->addr; 336 kp[c].flags = prl->flags; 337 c++; 338 if (kprl.addr != htonl(INADDR_ANY)) 339 break; 340 } 341 out: 342 rcu_read_unlock(); 343 344 len = sizeof(*kp) * c; 345 ret = 0; 346 if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen)) 347 ret = -EFAULT; 348 349 kfree(kp); 350 351 return ret; 352 } 353 354 static int 355 ipip6_tunnel_add_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a, int chg) 356 { 357 struct ip_tunnel_prl_entry *p; 358 int err = 0; 359 360 if (a->addr == htonl(INADDR_ANY)) 361 return -EINVAL; 362 363 ASSERT_RTNL(); 364 365 for (p = rtnl_dereference(t->prl); p; p = rtnl_dereference(p->next)) { 366 if (p->addr == a->addr) { 367 if (chg) { 368 p->flags = a->flags; 369 goto out; 370 } 371 err = -EEXIST; 372 goto out; 373 } 374 } 375 376 if (chg) { 377 err = -ENXIO; 378 goto out; 379 } 380 381 p = kzalloc(sizeof(struct ip_tunnel_prl_entry), GFP_KERNEL); 382 if (!p) { 383 err = -ENOBUFS; 384 goto out; 385 } 386 387 p->next = t->prl; 388 p->addr = a->addr; 389 p->flags = a->flags; 390 t->prl_count++; 391 rcu_assign_pointer(t->prl, p); 392 out: 393 return err; 394 } 395 396 static void prl_list_destroy_rcu(struct rcu_head *head) 397 { 398 struct ip_tunnel_prl_entry *p, *n; 399 400 p = container_of(head, struct ip_tunnel_prl_entry, rcu_head); 401 do { 402 n = rcu_dereference_protected(p->next, 1); 403 kfree(p); 404 p = n; 405 } while (p); 406 } 407 408 static int 409 ipip6_tunnel_del_prl(struct ip_tunnel *t, struct ip_tunnel_prl *a) 410 { 411 struct ip_tunnel_prl_entry *x; 412 struct ip_tunnel_prl_entry __rcu **p; 413 int err = 0; 414 415 ASSERT_RTNL(); 416 417 if (a && a->addr != htonl(INADDR_ANY)) { 418 for (p = &t->prl; 419 (x = rtnl_dereference(*p)) != NULL; 420 p = &x->next) { 421 if (x->addr == a->addr) { 422 *p = x->next; 423 kfree_rcu(x, rcu_head); 424 t->prl_count--; 425 goto out; 426 } 427 } 428 err = -ENXIO; 429 } else { 430 x = rtnl_dereference(t->prl); 431 if (x) { 432 t->prl_count = 0; 433 call_rcu(&x->rcu_head, prl_list_destroy_rcu); 434 t->prl = NULL; 435 } 436 } 437 out: 438 return err; 439 } 440 441 static int 442 isatap_chksrc(struct sk_buff *skb, const struct iphdr *iph, struct ip_tunnel *t) 443 { 444 struct ip_tunnel_prl_entry *p; 445 int ok = 1; 446 447 rcu_read_lock(); 448 p = __ipip6_tunnel_locate_prl(t, iph->saddr); 449 if (p) { 450 if (p->flags & PRL_DEFAULT) 451 skb->ndisc_nodetype = NDISC_NODETYPE_DEFAULT; 452 else 453 skb->ndisc_nodetype = NDISC_NODETYPE_NODEFAULT; 454 } else { 455 const struct in6_addr *addr6 = &ipv6_hdr(skb)->saddr; 456 457 if (ipv6_addr_is_isatap(addr6) && 458 (addr6->s6_addr32[3] == iph->saddr) && 459 ipv6_chk_prefix(addr6, t->dev)) 460 skb->ndisc_nodetype = NDISC_NODETYPE_HOST; 461 else 462 ok = 0; 463 } 464 rcu_read_unlock(); 465 return ok; 466 } 467 468 static void ipip6_tunnel_uninit(struct net_device *dev) 469 { 470 struct ip_tunnel *tunnel = netdev_priv(dev); 471 struct sit_net *sitn = net_generic(tunnel->net, sit_net_id); 472 473 if (dev == sitn->fb_tunnel_dev) { 474 RCU_INIT_POINTER(sitn->tunnels_wc[0], NULL); 475 } else { 476 ipip6_tunnel_unlink(sitn, tunnel); 477 ipip6_tunnel_del_prl(tunnel, NULL); 478 } 479 ip_tunnel_dst_reset_all(tunnel); 480 dev_put(dev); 481 } 482 483 /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH 484 * if sufficient data bytes are available 485 */ 486 static int ipip6_err_gen_icmpv6_unreach(struct sk_buff *skb) 487 { 488 const struct iphdr *iph = (const struct iphdr *) skb->data; 489 struct rt6_info *rt; 490 struct sk_buff *skb2; 491 492 if (!pskb_may_pull(skb, iph->ihl * 4 + sizeof(struct ipv6hdr) + 8)) 493 return 1; 494 495 skb2 = skb_clone(skb, GFP_ATOMIC); 496 497 if (!skb2) 498 return 1; 499 500 skb_dst_drop(skb2); 501 skb_pull(skb2, iph->ihl * 4); 502 skb_reset_network_header(skb2); 503 504 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0); 505 506 if (rt && rt->dst.dev) 507 skb2->dev = rt->dst.dev; 508 509 icmpv6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); 510 511 if (rt) 512 ip6_rt_put(rt); 513 514 kfree_skb(skb2); 515 516 return 0; 517 } 518 519 static int ipip6_err(struct sk_buff *skb, u32 info) 520 { 521 const struct iphdr *iph = (const struct iphdr *)skb->data; 522 const int type = icmp_hdr(skb)->type; 523 const int code = icmp_hdr(skb)->code; 524 struct ip_tunnel *t; 525 int err; 526 527 switch (type) { 528 default: 529 case ICMP_PARAMETERPROB: 530 return 0; 531 532 case ICMP_DEST_UNREACH: 533 switch (code) { 534 case ICMP_SR_FAILED: 535 /* Impossible event. */ 536 return 0; 537 default: 538 /* All others are translated to HOST_UNREACH. 539 rfc2003 contains "deep thoughts" about NET_UNREACH, 540 I believe they are just ether pollution. --ANK 541 */ 542 break; 543 } 544 break; 545 case ICMP_TIME_EXCEEDED: 546 if (code != ICMP_EXC_TTL) 547 return 0; 548 break; 549 case ICMP_REDIRECT: 550 break; 551 } 552 553 err = -ENOENT; 554 555 t = ipip6_tunnel_lookup(dev_net(skb->dev), 556 skb->dev, 557 iph->daddr, 558 iph->saddr); 559 if (t == NULL) 560 goto out; 561 562 if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) { 563 ipv4_update_pmtu(skb, dev_net(skb->dev), info, 564 t->parms.link, 0, IPPROTO_IPV6, 0); 565 err = 0; 566 goto out; 567 } 568 if (type == ICMP_REDIRECT) { 569 ipv4_redirect(skb, dev_net(skb->dev), t->parms.link, 0, 570 IPPROTO_IPV6, 0); 571 err = 0; 572 goto out; 573 } 574 575 if (t->parms.iph.daddr == 0) 576 goto out; 577 578 err = 0; 579 if (!ipip6_err_gen_icmpv6_unreach(skb)) 580 goto out; 581 582 if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) 583 goto out; 584 585 if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) 586 t->err_count++; 587 else 588 t->err_count = 1; 589 t->err_time = jiffies; 590 out: 591 return err; 592 } 593 594 static inline bool is_spoofed_6rd(struct ip_tunnel *tunnel, const __be32 v4addr, 595 const struct in6_addr *v6addr) 596 { 597 __be32 v4embed = 0; 598 if (check_6rd(tunnel, v6addr, &v4embed) && v4addr != v4embed) 599 return true; 600 return false; 601 } 602 603 /* Checks if an address matches an address on the tunnel interface. 604 * Used to detect the NAT of proto 41 packets and let them pass spoofing test. 605 * Long story: 606 * This function is called after we considered the packet as spoofed 607 * in is_spoofed_6rd. 608 * We may have a router that is doing NAT for proto 41 packets 609 * for an internal station. Destination a.a.a.a/PREFIX:bbbb:bbbb 610 * will be translated to n.n.n.n/PREFIX:bbbb:bbbb. And is_spoofed_6rd 611 * function will return true, dropping the packet. 612 * But, we can still check if is spoofed against the IP 613 * addresses associated with the interface. 614 */ 615 static bool only_dnatted(const struct ip_tunnel *tunnel, 616 const struct in6_addr *v6dst) 617 { 618 int prefix_len; 619 620 #ifdef CONFIG_IPV6_SIT_6RD 621 prefix_len = tunnel->ip6rd.prefixlen + 32 622 - tunnel->ip6rd.relay_prefixlen; 623 #else 624 prefix_len = 48; 625 #endif 626 return ipv6_chk_custom_prefix(v6dst, prefix_len, tunnel->dev); 627 } 628 629 /* Returns true if a packet is spoofed */ 630 static bool packet_is_spoofed(struct sk_buff *skb, 631 const struct iphdr *iph, 632 struct ip_tunnel *tunnel) 633 { 634 const struct ipv6hdr *ipv6h; 635 636 if (tunnel->dev->priv_flags & IFF_ISATAP) { 637 if (!isatap_chksrc(skb, iph, tunnel)) 638 return true; 639 640 return false; 641 } 642 643 if (tunnel->dev->flags & IFF_POINTOPOINT) 644 return false; 645 646 ipv6h = ipv6_hdr(skb); 647 648 if (unlikely(is_spoofed_6rd(tunnel, iph->saddr, &ipv6h->saddr))) { 649 net_warn_ratelimited("Src spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 650 &iph->saddr, &ipv6h->saddr, 651 &iph->daddr, &ipv6h->daddr); 652 return true; 653 } 654 655 if (likely(!is_spoofed_6rd(tunnel, iph->daddr, &ipv6h->daddr))) 656 return false; 657 658 if (only_dnatted(tunnel, &ipv6h->daddr)) 659 return false; 660 661 net_warn_ratelimited("Dst spoofed %pI4/%pI6c -> %pI4/%pI6c\n", 662 &iph->saddr, &ipv6h->saddr, 663 &iph->daddr, &ipv6h->daddr); 664 return true; 665 } 666 667 static int ipip6_rcv(struct sk_buff *skb) 668 { 669 const struct iphdr *iph = ip_hdr(skb); 670 struct ip_tunnel *tunnel; 671 int err; 672 673 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 674 iph->saddr, iph->daddr); 675 if (tunnel != NULL) { 676 struct pcpu_sw_netstats *tstats; 677 678 if (tunnel->parms.iph.protocol != IPPROTO_IPV6 && 679 tunnel->parms.iph.protocol != 0) 680 goto out; 681 682 skb->mac_header = skb->network_header; 683 skb_reset_network_header(skb); 684 IPCB(skb)->flags = 0; 685 skb->protocol = htons(ETH_P_IPV6); 686 687 if (packet_is_spoofed(skb, iph, tunnel)) { 688 tunnel->dev->stats.rx_errors++; 689 goto out; 690 } 691 692 __skb_tunnel_rx(skb, tunnel->dev, tunnel->net); 693 694 err = IP_ECN_decapsulate(iph, skb); 695 if (unlikely(err)) { 696 if (log_ecn_error) 697 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 698 &iph->saddr, iph->tos); 699 if (err > 1) { 700 ++tunnel->dev->stats.rx_frame_errors; 701 ++tunnel->dev->stats.rx_errors; 702 goto out; 703 } 704 } 705 706 tstats = this_cpu_ptr(tunnel->dev->tstats); 707 u64_stats_update_begin(&tstats->syncp); 708 tstats->rx_packets++; 709 tstats->rx_bytes += skb->len; 710 u64_stats_update_end(&tstats->syncp); 711 712 netif_rx(skb); 713 714 return 0; 715 } 716 717 /* no tunnel matched, let upstream know, ipsec may handle it */ 718 return 1; 719 out: 720 kfree_skb(skb); 721 return 0; 722 } 723 724 static const struct tnl_ptk_info tpi = { 725 /* no tunnel info required for ipip. */ 726 .proto = htons(ETH_P_IP), 727 }; 728 729 static int ipip_rcv(struct sk_buff *skb) 730 { 731 const struct iphdr *iph; 732 struct ip_tunnel *tunnel; 733 734 iph = ip_hdr(skb); 735 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 736 iph->saddr, iph->daddr); 737 if (tunnel != NULL) { 738 if (tunnel->parms.iph.protocol != IPPROTO_IPIP && 739 tunnel->parms.iph.protocol != 0) 740 goto drop; 741 742 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 743 goto drop; 744 if (iptunnel_pull_header(skb, 0, tpi.proto)) 745 goto drop; 746 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); 747 } 748 749 return 1; 750 751 drop: 752 kfree_skb(skb); 753 return 0; 754 } 755 756 /* 757 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function 758 * stores the embedded IPv4 address in v4dst and returns true. 759 */ 760 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 761 __be32 *v4dst) 762 { 763 #ifdef CONFIG_IPV6_SIT_6RD 764 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 765 tunnel->ip6rd.prefixlen)) { 766 unsigned int pbw0, pbi0; 767 int pbi1; 768 u32 d; 769 770 pbw0 = tunnel->ip6rd.prefixlen >> 5; 771 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 772 773 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 774 tunnel->ip6rd.relay_prefixlen; 775 776 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 777 if (pbi1 > 0) 778 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 779 (32 - pbi1); 780 781 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); 782 return true; 783 } 784 #else 785 if (v6dst->s6_addr16[0] == htons(0x2002)) { 786 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 787 memcpy(v4dst, &v6dst->s6_addr16[1], 4); 788 return true; 789 } 790 #endif 791 return false; 792 } 793 794 static inline __be32 try_6rd(struct ip_tunnel *tunnel, 795 const struct in6_addr *v6dst) 796 { 797 __be32 dst = 0; 798 check_6rd(tunnel, v6dst, &dst); 799 return dst; 800 } 801 802 /* 803 * This function assumes it is being called from dev_queue_xmit() 804 * and that skb is filled properly by that function. 805 */ 806 807 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 808 struct net_device *dev) 809 { 810 struct ip_tunnel *tunnel = netdev_priv(dev); 811 const struct iphdr *tiph = &tunnel->parms.iph; 812 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 813 u8 tos = tunnel->parms.iph.tos; 814 __be16 df = tiph->frag_off; 815 struct rtable *rt; /* Route to the other host */ 816 struct net_device *tdev; /* Device to other host */ 817 unsigned int max_headroom; /* The extra header space needed */ 818 __be32 dst = tiph->daddr; 819 struct flowi4 fl4; 820 int mtu; 821 const struct in6_addr *addr6; 822 int addr_type; 823 u8 ttl; 824 int err; 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 == NULL) { 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 == NULL) { 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 if (df) { 915 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 916 917 if (mtu < 68) { 918 dev->stats.collisions++; 919 ip_rt_put(rt); 920 goto tx_error; 921 } 922 923 if (mtu < IPV6_MIN_MTU) { 924 mtu = IPV6_MIN_MTU; 925 df = 0; 926 } 927 928 if (tunnel->parms.iph.daddr && skb_dst(skb)) 929 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 930 931 if (skb->len > mtu && !skb_is_gso(skb)) { 932 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 933 ip_rt_put(rt); 934 goto tx_error; 935 } 936 } 937 938 if (tunnel->err_count > 0) { 939 if (time_before(jiffies, 940 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 941 tunnel->err_count--; 942 dst_link_failure(skb); 943 } else 944 tunnel->err_count = 0; 945 } 946 947 /* 948 * Okay, now see if we can stuff it in the buffer as-is. 949 */ 950 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 951 952 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 953 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 954 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 955 if (!new_skb) { 956 ip_rt_put(rt); 957 dev->stats.tx_dropped++; 958 kfree_skb(skb); 959 return NETDEV_TX_OK; 960 } 961 if (skb->sk) 962 skb_set_owner_w(new_skb, skb->sk); 963 dev_kfree_skb(skb); 964 skb = new_skb; 965 iph6 = ipv6_hdr(skb); 966 } 967 ttl = tiph->ttl; 968 if (ttl == 0) 969 ttl = iph6->hop_limit; 970 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 971 972 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT); 973 if (IS_ERR(skb)) { 974 ip_rt_put(rt); 975 goto out; 976 } 977 978 err = iptunnel_xmit(skb->sk, rt, skb, fl4.saddr, fl4.daddr, 979 IPPROTO_IPV6, tos, ttl, df, 980 !net_eq(tunnel->net, dev_net(dev))); 981 iptunnel_xmit_stats(err, &dev->stats, dev->tstats); 982 return NETDEV_TX_OK; 983 984 tx_error_icmp: 985 dst_link_failure(skb); 986 tx_error: 987 kfree_skb(skb); 988 out: 989 dev->stats.tx_errors++; 990 return NETDEV_TX_OK; 991 } 992 993 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 994 { 995 struct ip_tunnel *tunnel = netdev_priv(dev); 996 const struct iphdr *tiph = &tunnel->parms.iph; 997 998 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP); 999 if (IS_ERR(skb)) 1000 goto out; 1001 1002 ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP); 1003 return NETDEV_TX_OK; 1004 out: 1005 dev->stats.tx_errors++; 1006 return NETDEV_TX_OK; 1007 } 1008 1009 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, 1010 struct net_device *dev) 1011 { 1012 switch (skb->protocol) { 1013 case htons(ETH_P_IP): 1014 ipip_tunnel_xmit(skb, dev); 1015 break; 1016 case htons(ETH_P_IPV6): 1017 ipip6_tunnel_xmit(skb, dev); 1018 break; 1019 default: 1020 goto tx_err; 1021 } 1022 1023 return NETDEV_TX_OK; 1024 1025 tx_err: 1026 dev->stats.tx_errors++; 1027 kfree_skb(skb); 1028 return NETDEV_TX_OK; 1029 1030 } 1031 1032 static void ipip6_tunnel_bind_dev(struct net_device *dev) 1033 { 1034 struct net_device *tdev = NULL; 1035 struct ip_tunnel *tunnel; 1036 const struct iphdr *iph; 1037 struct flowi4 fl4; 1038 1039 tunnel = netdev_priv(dev); 1040 iph = &tunnel->parms.iph; 1041 1042 if (iph->daddr) { 1043 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, 1044 NULL, 1045 iph->daddr, iph->saddr, 1046 0, 0, 1047 IPPROTO_IPV6, 1048 RT_TOS(iph->tos), 1049 tunnel->parms.link); 1050 1051 if (!IS_ERR(rt)) { 1052 tdev = rt->dst.dev; 1053 ip_rt_put(rt); 1054 } 1055 dev->flags |= IFF_POINTOPOINT; 1056 } 1057 1058 if (!tdev && tunnel->parms.link) 1059 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 1060 1061 if (tdev) { 1062 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 1063 dev->mtu = tdev->mtu - sizeof(struct iphdr); 1064 if (dev->mtu < IPV6_MIN_MTU) 1065 dev->mtu = IPV6_MIN_MTU; 1066 } 1067 dev->iflink = tunnel->parms.link; 1068 } 1069 1070 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p) 1071 { 1072 struct net *net = t->net; 1073 struct sit_net *sitn = net_generic(net, sit_net_id); 1074 1075 ipip6_tunnel_unlink(sitn, t); 1076 synchronize_net(); 1077 t->parms.iph.saddr = p->iph.saddr; 1078 t->parms.iph.daddr = p->iph.daddr; 1079 memcpy(t->dev->dev_addr, &p->iph.saddr, 4); 1080 memcpy(t->dev->broadcast, &p->iph.daddr, 4); 1081 ipip6_tunnel_link(sitn, t); 1082 t->parms.iph.ttl = p->iph.ttl; 1083 t->parms.iph.tos = p->iph.tos; 1084 if (t->parms.link != p->link) { 1085 t->parms.link = p->link; 1086 ipip6_tunnel_bind_dev(t->dev); 1087 } 1088 ip_tunnel_dst_reset_all(t); 1089 netdev_state_change(t->dev); 1090 } 1091 1092 #ifdef CONFIG_IPV6_SIT_6RD 1093 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, 1094 struct ip_tunnel_6rd *ip6rd) 1095 { 1096 struct in6_addr prefix; 1097 __be32 relay_prefix; 1098 1099 if (ip6rd->relay_prefixlen > 32 || 1100 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) 1101 return -EINVAL; 1102 1103 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); 1104 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) 1105 return -EINVAL; 1106 if (ip6rd->relay_prefixlen) 1107 relay_prefix = ip6rd->relay_prefix & 1108 htonl(0xffffffffUL << 1109 (32 - ip6rd->relay_prefixlen)); 1110 else 1111 relay_prefix = 0; 1112 if (relay_prefix != ip6rd->relay_prefix) 1113 return -EINVAL; 1114 1115 t->ip6rd.prefix = prefix; 1116 t->ip6rd.relay_prefix = relay_prefix; 1117 t->ip6rd.prefixlen = ip6rd->prefixlen; 1118 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; 1119 ip_tunnel_dst_reset_all(t); 1120 netdev_state_change(t->dev); 1121 return 0; 1122 } 1123 #endif 1124 1125 static int 1126 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 1127 { 1128 int err = 0; 1129 struct ip_tunnel_parm p; 1130 struct ip_tunnel_prl prl; 1131 struct ip_tunnel *t = netdev_priv(dev); 1132 struct net *net = t->net; 1133 struct sit_net *sitn = net_generic(net, sit_net_id); 1134 #ifdef CONFIG_IPV6_SIT_6RD 1135 struct ip_tunnel_6rd ip6rd; 1136 #endif 1137 1138 switch (cmd) { 1139 case SIOCGETTUNNEL: 1140 #ifdef CONFIG_IPV6_SIT_6RD 1141 case SIOCGET6RD: 1142 #endif 1143 if (dev == sitn->fb_tunnel_dev) { 1144 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 1145 err = -EFAULT; 1146 break; 1147 } 1148 t = ipip6_tunnel_locate(net, &p, 0); 1149 if (t == NULL) 1150 t = netdev_priv(dev); 1151 } 1152 1153 err = -EFAULT; 1154 if (cmd == SIOCGETTUNNEL) { 1155 memcpy(&p, &t->parms, sizeof(p)); 1156 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 1157 sizeof(p))) 1158 goto done; 1159 #ifdef CONFIG_IPV6_SIT_6RD 1160 } else { 1161 ip6rd.prefix = t->ip6rd.prefix; 1162 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 1163 ip6rd.prefixlen = t->ip6rd.prefixlen; 1164 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 1165 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 1166 sizeof(ip6rd))) 1167 goto done; 1168 #endif 1169 } 1170 err = 0; 1171 break; 1172 1173 case SIOCADDTUNNEL: 1174 case SIOCCHGTUNNEL: 1175 err = -EPERM; 1176 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1177 goto done; 1178 1179 err = -EFAULT; 1180 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1181 goto done; 1182 1183 err = -EINVAL; 1184 if (p.iph.protocol != IPPROTO_IPV6 && 1185 p.iph.protocol != IPPROTO_IPIP && 1186 p.iph.protocol != 0) 1187 goto done; 1188 if (p.iph.version != 4 || 1189 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 1190 goto done; 1191 if (p.iph.ttl) 1192 p.iph.frag_off |= htons(IP_DF); 1193 1194 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 1195 1196 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 1197 if (t != NULL) { 1198 if (t->dev != dev) { 1199 err = -EEXIST; 1200 break; 1201 } 1202 } else { 1203 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 1204 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 1205 err = -EINVAL; 1206 break; 1207 } 1208 t = netdev_priv(dev); 1209 } 1210 1211 ipip6_tunnel_update(t, &p); 1212 } 1213 1214 if (t) { 1215 err = 0; 1216 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 1217 err = -EFAULT; 1218 } else 1219 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1220 break; 1221 1222 case SIOCDELTUNNEL: 1223 err = -EPERM; 1224 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1225 goto done; 1226 1227 if (dev == sitn->fb_tunnel_dev) { 1228 err = -EFAULT; 1229 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1230 goto done; 1231 err = -ENOENT; 1232 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 1233 goto done; 1234 err = -EPERM; 1235 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1236 goto done; 1237 dev = t->dev; 1238 } 1239 unregister_netdevice(dev); 1240 err = 0; 1241 break; 1242 1243 case SIOCGETPRL: 1244 err = -EINVAL; 1245 if (dev == sitn->fb_tunnel_dev) 1246 goto done; 1247 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1248 break; 1249 1250 case SIOCADDPRL: 1251 case SIOCDELPRL: 1252 case SIOCCHGPRL: 1253 err = -EPERM; 1254 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1255 goto done; 1256 err = -EINVAL; 1257 if (dev == sitn->fb_tunnel_dev) 1258 goto done; 1259 err = -EFAULT; 1260 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1261 goto done; 1262 1263 switch (cmd) { 1264 case SIOCDELPRL: 1265 err = ipip6_tunnel_del_prl(t, &prl); 1266 break; 1267 case SIOCADDPRL: 1268 case SIOCCHGPRL: 1269 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1270 break; 1271 } 1272 ip_tunnel_dst_reset_all(t); 1273 netdev_state_change(dev); 1274 break; 1275 1276 #ifdef CONFIG_IPV6_SIT_6RD 1277 case SIOCADD6RD: 1278 case SIOCCHG6RD: 1279 case SIOCDEL6RD: 1280 err = -EPERM; 1281 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1282 goto done; 1283 1284 err = -EFAULT; 1285 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1286 sizeof(ip6rd))) 1287 goto done; 1288 1289 if (cmd != SIOCDEL6RD) { 1290 err = ipip6_tunnel_update_6rd(t, &ip6rd); 1291 if (err < 0) 1292 goto done; 1293 } else 1294 ipip6_tunnel_clone_6rd(dev, sitn); 1295 1296 err = 0; 1297 break; 1298 #endif 1299 1300 default: 1301 err = -EINVAL; 1302 } 1303 1304 done: 1305 return err; 1306 } 1307 1308 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1309 { 1310 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1311 return -EINVAL; 1312 dev->mtu = new_mtu; 1313 return 0; 1314 } 1315 1316 static const struct net_device_ops ipip6_netdev_ops = { 1317 .ndo_uninit = ipip6_tunnel_uninit, 1318 .ndo_start_xmit = sit_tunnel_xmit, 1319 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1320 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1321 .ndo_get_stats64 = ip_tunnel_get_stats64, 1322 }; 1323 1324 static void ipip6_dev_free(struct net_device *dev) 1325 { 1326 struct ip_tunnel *tunnel = netdev_priv(dev); 1327 1328 free_percpu(tunnel->dst_cache); 1329 free_percpu(dev->tstats); 1330 free_netdev(dev); 1331 } 1332 1333 #define SIT_FEATURES (NETIF_F_SG | \ 1334 NETIF_F_FRAGLIST | \ 1335 NETIF_F_HIGHDMA | \ 1336 NETIF_F_GSO_SOFTWARE | \ 1337 NETIF_F_HW_CSUM) 1338 1339 static void ipip6_tunnel_setup(struct net_device *dev) 1340 { 1341 dev->netdev_ops = &ipip6_netdev_ops; 1342 dev->destructor = ipip6_dev_free; 1343 1344 dev->type = ARPHRD_SIT; 1345 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr); 1346 dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr); 1347 dev->flags = IFF_NOARP; 1348 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1349 dev->iflink = 0; 1350 dev->addr_len = 4; 1351 dev->features |= NETIF_F_LLTX; 1352 dev->features |= SIT_FEATURES; 1353 dev->hw_features |= SIT_FEATURES; 1354 } 1355 1356 static int ipip6_tunnel_init(struct net_device *dev) 1357 { 1358 struct ip_tunnel *tunnel = netdev_priv(dev); 1359 1360 tunnel->dev = dev; 1361 tunnel->net = dev_net(dev); 1362 1363 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1364 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1365 1366 ipip6_tunnel_bind_dev(dev); 1367 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1368 if (!dev->tstats) 1369 return -ENOMEM; 1370 1371 tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst); 1372 if (!tunnel->dst_cache) { 1373 free_percpu(dev->tstats); 1374 return -ENOMEM; 1375 } 1376 1377 return 0; 1378 } 1379 1380 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1381 { 1382 struct ip_tunnel *tunnel = netdev_priv(dev); 1383 struct iphdr *iph = &tunnel->parms.iph; 1384 struct net *net = dev_net(dev); 1385 struct sit_net *sitn = net_generic(net, sit_net_id); 1386 1387 tunnel->dev = dev; 1388 tunnel->net = dev_net(dev); 1389 strcpy(tunnel->parms.name, dev->name); 1390 1391 iph->version = 4; 1392 iph->protocol = IPPROTO_IPV6; 1393 iph->ihl = 5; 1394 iph->ttl = 64; 1395 1396 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1397 if (!dev->tstats) 1398 return -ENOMEM; 1399 1400 tunnel->dst_cache = alloc_percpu(struct ip_tunnel_dst); 1401 if (!tunnel->dst_cache) { 1402 free_percpu(dev->tstats); 1403 return -ENOMEM; 1404 } 1405 1406 dev_hold(dev); 1407 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1408 return 0; 1409 } 1410 1411 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[]) 1412 { 1413 u8 proto; 1414 1415 if (!data || !data[IFLA_IPTUN_PROTO]) 1416 return 0; 1417 1418 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1419 if (proto != IPPROTO_IPV6 && 1420 proto != IPPROTO_IPIP && 1421 proto != 0) 1422 return -EINVAL; 1423 1424 return 0; 1425 } 1426 1427 static void ipip6_netlink_parms(struct nlattr *data[], 1428 struct ip_tunnel_parm *parms) 1429 { 1430 memset(parms, 0, sizeof(*parms)); 1431 1432 parms->iph.version = 4; 1433 parms->iph.protocol = IPPROTO_IPV6; 1434 parms->iph.ihl = 5; 1435 parms->iph.ttl = 64; 1436 1437 if (!data) 1438 return; 1439 1440 if (data[IFLA_IPTUN_LINK]) 1441 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1442 1443 if (data[IFLA_IPTUN_LOCAL]) 1444 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); 1445 1446 if (data[IFLA_IPTUN_REMOTE]) 1447 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); 1448 1449 if (data[IFLA_IPTUN_TTL]) { 1450 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); 1451 if (parms->iph.ttl) 1452 parms->iph.frag_off = htons(IP_DF); 1453 } 1454 1455 if (data[IFLA_IPTUN_TOS]) 1456 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); 1457 1458 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) 1459 parms->iph.frag_off = htons(IP_DF); 1460 1461 if (data[IFLA_IPTUN_FLAGS]) 1462 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); 1463 1464 if (data[IFLA_IPTUN_PROTO]) 1465 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1466 1467 } 1468 1469 #ifdef CONFIG_IPV6_SIT_6RD 1470 /* This function returns true when 6RD attributes are present in the nl msg */ 1471 static bool ipip6_netlink_6rd_parms(struct nlattr *data[], 1472 struct ip_tunnel_6rd *ip6rd) 1473 { 1474 bool ret = false; 1475 memset(ip6rd, 0, sizeof(*ip6rd)); 1476 1477 if (!data) 1478 return ret; 1479 1480 if (data[IFLA_IPTUN_6RD_PREFIX]) { 1481 ret = true; 1482 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX], 1483 sizeof(struct in6_addr)); 1484 } 1485 1486 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { 1487 ret = true; 1488 ip6rd->relay_prefix = 1489 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); 1490 } 1491 1492 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { 1493 ret = true; 1494 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); 1495 } 1496 1497 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { 1498 ret = true; 1499 ip6rd->relay_prefixlen = 1500 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); 1501 } 1502 1503 return ret; 1504 } 1505 #endif 1506 1507 static int ipip6_newlink(struct net *src_net, struct net_device *dev, 1508 struct nlattr *tb[], struct nlattr *data[]) 1509 { 1510 struct net *net = dev_net(dev); 1511 struct ip_tunnel *nt; 1512 #ifdef CONFIG_IPV6_SIT_6RD 1513 struct ip_tunnel_6rd ip6rd; 1514 #endif 1515 int err; 1516 1517 nt = netdev_priv(dev); 1518 ipip6_netlink_parms(data, &nt->parms); 1519 1520 if (ipip6_tunnel_locate(net, &nt->parms, 0)) 1521 return -EEXIST; 1522 1523 err = ipip6_tunnel_create(dev); 1524 if (err < 0) 1525 return err; 1526 1527 #ifdef CONFIG_IPV6_SIT_6RD 1528 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1529 err = ipip6_tunnel_update_6rd(nt, &ip6rd); 1530 #endif 1531 1532 return err; 1533 } 1534 1535 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], 1536 struct nlattr *data[]) 1537 { 1538 struct ip_tunnel *t = netdev_priv(dev); 1539 struct ip_tunnel_parm p; 1540 struct net *net = t->net; 1541 struct sit_net *sitn = net_generic(net, sit_net_id); 1542 #ifdef CONFIG_IPV6_SIT_6RD 1543 struct ip_tunnel_6rd ip6rd; 1544 #endif 1545 1546 if (dev == sitn->fb_tunnel_dev) 1547 return -EINVAL; 1548 1549 ipip6_netlink_parms(data, &p); 1550 1551 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || 1552 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) 1553 return -EINVAL; 1554 1555 t = ipip6_tunnel_locate(net, &p, 0); 1556 1557 if (t) { 1558 if (t->dev != dev) 1559 return -EEXIST; 1560 } else 1561 t = netdev_priv(dev); 1562 1563 ipip6_tunnel_update(t, &p); 1564 1565 #ifdef CONFIG_IPV6_SIT_6RD 1566 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1567 return ipip6_tunnel_update_6rd(t, &ip6rd); 1568 #endif 1569 1570 return 0; 1571 } 1572 1573 static size_t ipip6_get_size(const struct net_device *dev) 1574 { 1575 return 1576 /* IFLA_IPTUN_LINK */ 1577 nla_total_size(4) + 1578 /* IFLA_IPTUN_LOCAL */ 1579 nla_total_size(4) + 1580 /* IFLA_IPTUN_REMOTE */ 1581 nla_total_size(4) + 1582 /* IFLA_IPTUN_TTL */ 1583 nla_total_size(1) + 1584 /* IFLA_IPTUN_TOS */ 1585 nla_total_size(1) + 1586 /* IFLA_IPTUN_PMTUDISC */ 1587 nla_total_size(1) + 1588 /* IFLA_IPTUN_FLAGS */ 1589 nla_total_size(2) + 1590 /* IFLA_IPTUN_PROTO */ 1591 nla_total_size(1) + 1592 #ifdef CONFIG_IPV6_SIT_6RD 1593 /* IFLA_IPTUN_6RD_PREFIX */ 1594 nla_total_size(sizeof(struct in6_addr)) + 1595 /* IFLA_IPTUN_6RD_RELAY_PREFIX */ 1596 nla_total_size(4) + 1597 /* IFLA_IPTUN_6RD_PREFIXLEN */ 1598 nla_total_size(2) + 1599 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ 1600 nla_total_size(2) + 1601 #endif 1602 0; 1603 } 1604 1605 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1606 { 1607 struct ip_tunnel *tunnel = netdev_priv(dev); 1608 struct ip_tunnel_parm *parm = &tunnel->parms; 1609 1610 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1611 nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || 1612 nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || 1613 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || 1614 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || 1615 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, 1616 !!(parm->iph.frag_off & htons(IP_DF))) || 1617 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || 1618 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags)) 1619 goto nla_put_failure; 1620 1621 #ifdef CONFIG_IPV6_SIT_6RD 1622 if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr), 1623 &tunnel->ip6rd.prefix) || 1624 nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, 1625 tunnel->ip6rd.relay_prefix) || 1626 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, 1627 tunnel->ip6rd.prefixlen) || 1628 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, 1629 tunnel->ip6rd.relay_prefixlen)) 1630 goto nla_put_failure; 1631 #endif 1632 1633 return 0; 1634 1635 nla_put_failure: 1636 return -EMSGSIZE; 1637 } 1638 1639 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { 1640 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1641 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, 1642 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, 1643 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1644 [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, 1645 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, 1646 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, 1647 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1648 #ifdef CONFIG_IPV6_SIT_6RD 1649 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, 1650 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, 1651 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, 1652 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, 1653 #endif 1654 }; 1655 1656 static void ipip6_dellink(struct net_device *dev, struct list_head *head) 1657 { 1658 struct net *net = dev_net(dev); 1659 struct sit_net *sitn = net_generic(net, sit_net_id); 1660 1661 if (dev != sitn->fb_tunnel_dev) 1662 unregister_netdevice_queue(dev, head); 1663 } 1664 1665 static struct rtnl_link_ops sit_link_ops __read_mostly = { 1666 .kind = "sit", 1667 .maxtype = IFLA_IPTUN_MAX, 1668 .policy = ipip6_policy, 1669 .priv_size = sizeof(struct ip_tunnel), 1670 .setup = ipip6_tunnel_setup, 1671 .validate = ipip6_validate, 1672 .newlink = ipip6_newlink, 1673 .changelink = ipip6_changelink, 1674 .get_size = ipip6_get_size, 1675 .fill_info = ipip6_fill_info, 1676 .dellink = ipip6_dellink, 1677 }; 1678 1679 static struct xfrm_tunnel sit_handler __read_mostly = { 1680 .handler = ipip6_rcv, 1681 .err_handler = ipip6_err, 1682 .priority = 1, 1683 }; 1684 1685 static struct xfrm_tunnel ipip_handler __read_mostly = { 1686 .handler = ipip_rcv, 1687 .err_handler = ipip6_err, 1688 .priority = 2, 1689 }; 1690 1691 static void __net_exit sit_destroy_tunnels(struct net *net, 1692 struct list_head *head) 1693 { 1694 struct sit_net *sitn = net_generic(net, sit_net_id); 1695 struct net_device *dev, *aux; 1696 int prio; 1697 1698 for_each_netdev_safe(net, dev, aux) 1699 if (dev->rtnl_link_ops == &sit_link_ops) 1700 unregister_netdevice_queue(dev, head); 1701 1702 for (prio = 1; prio < 4; prio++) { 1703 int h; 1704 for (h = 0; h < HASH_SIZE; h++) { 1705 struct ip_tunnel *t; 1706 1707 t = rtnl_dereference(sitn->tunnels[prio][h]); 1708 while (t != NULL) { 1709 /* If dev is in the same netns, it has already 1710 * been added to the list by the previous loop. 1711 */ 1712 if (!net_eq(dev_net(t->dev), net)) 1713 unregister_netdevice_queue(t->dev, 1714 head); 1715 t = rtnl_dereference(t->next); 1716 } 1717 } 1718 } 1719 } 1720 1721 static int __net_init sit_init_net(struct net *net) 1722 { 1723 struct sit_net *sitn = net_generic(net, sit_net_id); 1724 struct ip_tunnel *t; 1725 int err; 1726 1727 sitn->tunnels[0] = sitn->tunnels_wc; 1728 sitn->tunnels[1] = sitn->tunnels_l; 1729 sitn->tunnels[2] = sitn->tunnels_r; 1730 sitn->tunnels[3] = sitn->tunnels_r_l; 1731 1732 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1733 NET_NAME_UNKNOWN, 1734 ipip6_tunnel_setup); 1735 if (!sitn->fb_tunnel_dev) { 1736 err = -ENOMEM; 1737 goto err_alloc_dev; 1738 } 1739 dev_net_set(sitn->fb_tunnel_dev, net); 1740 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; 1741 /* FB netdevice is special: we have one, and only one per netns. 1742 * Allowing to move it to another netns is clearly unsafe. 1743 */ 1744 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1745 1746 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1747 if (err) 1748 goto err_dev_free; 1749 1750 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1751 1752 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1753 goto err_reg_dev; 1754 1755 t = netdev_priv(sitn->fb_tunnel_dev); 1756 1757 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1758 return 0; 1759 1760 err_reg_dev: 1761 dev_put(sitn->fb_tunnel_dev); 1762 err_dev_free: 1763 ipip6_dev_free(sitn->fb_tunnel_dev); 1764 err_alloc_dev: 1765 return err; 1766 } 1767 1768 static void __net_exit sit_exit_net(struct net *net) 1769 { 1770 LIST_HEAD(list); 1771 1772 rtnl_lock(); 1773 sit_destroy_tunnels(net, &list); 1774 unregister_netdevice_many(&list); 1775 rtnl_unlock(); 1776 } 1777 1778 static struct pernet_operations sit_net_ops = { 1779 .init = sit_init_net, 1780 .exit = sit_exit_net, 1781 .id = &sit_net_id, 1782 .size = sizeof(struct sit_net), 1783 }; 1784 1785 static void __exit sit_cleanup(void) 1786 { 1787 rtnl_link_unregister(&sit_link_ops); 1788 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1789 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1790 1791 unregister_pernet_device(&sit_net_ops); 1792 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1793 } 1794 1795 static int __init sit_init(void) 1796 { 1797 int err; 1798 1799 pr_info("IPv6 over IPv4 tunneling driver\n"); 1800 1801 err = register_pernet_device(&sit_net_ops); 1802 if (err < 0) 1803 return err; 1804 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1805 if (err < 0) { 1806 pr_info("%s: can't register ip6ip4\n", __func__); 1807 goto xfrm_tunnel_failed; 1808 } 1809 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 1810 if (err < 0) { 1811 pr_info("%s: can't register ip4ip4\n", __func__); 1812 goto xfrm_tunnel4_failed; 1813 } 1814 err = rtnl_link_register(&sit_link_ops); 1815 if (err < 0) 1816 goto rtnl_link_failed; 1817 1818 out: 1819 return err; 1820 1821 rtnl_link_failed: 1822 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1823 xfrm_tunnel4_failed: 1824 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1825 xfrm_tunnel_failed: 1826 unregister_pernet_device(&sit_net_ops); 1827 goto out; 1828 } 1829 1830 module_init(sit_init); 1831 module_exit(sit_cleanup); 1832 MODULE_LICENSE("GPL"); 1833 MODULE_ALIAS_RTNL_LINK("sit"); 1834 MODULE_ALIAS_NETDEV("sit0"); 1835