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_sw_netstats *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 u64_stats_update_begin(&tstats->syncp); 706 tstats->rx_packets++; 707 tstats->rx_bytes += skb->len; 708 u64_stats_update_end(&tstats->syncp); 709 710 netif_rx(skb); 711 712 return 0; 713 } 714 715 /* no tunnel matched, let upstream know, ipsec may handle it */ 716 return 1; 717 out: 718 kfree_skb(skb); 719 return 0; 720 } 721 722 static const struct tnl_ptk_info tpi = { 723 /* no tunnel info required for ipip. */ 724 .proto = htons(ETH_P_IP), 725 }; 726 727 static int ipip_rcv(struct sk_buff *skb) 728 { 729 const struct iphdr *iph; 730 struct ip_tunnel *tunnel; 731 732 iph = ip_hdr(skb); 733 tunnel = ipip6_tunnel_lookup(dev_net(skb->dev), skb->dev, 734 iph->saddr, iph->daddr); 735 if (tunnel != NULL) { 736 if (tunnel->parms.iph.protocol != IPPROTO_IPIP && 737 tunnel->parms.iph.protocol != 0) 738 goto drop; 739 740 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) 741 goto drop; 742 if (iptunnel_pull_header(skb, 0, tpi.proto)) 743 goto drop; 744 return ip_tunnel_rcv(tunnel, skb, &tpi, log_ecn_error); 745 } 746 747 return 1; 748 749 drop: 750 kfree_skb(skb); 751 return 0; 752 } 753 754 /* 755 * If the IPv6 address comes from 6rd / 6to4 (RFC 3056) addr space this function 756 * stores the embedded IPv4 address in v4dst and returns true. 757 */ 758 static bool check_6rd(struct ip_tunnel *tunnel, const struct in6_addr *v6dst, 759 __be32 *v4dst) 760 { 761 #ifdef CONFIG_IPV6_SIT_6RD 762 if (ipv6_prefix_equal(v6dst, &tunnel->ip6rd.prefix, 763 tunnel->ip6rd.prefixlen)) { 764 unsigned int pbw0, pbi0; 765 int pbi1; 766 u32 d; 767 768 pbw0 = tunnel->ip6rd.prefixlen >> 5; 769 pbi0 = tunnel->ip6rd.prefixlen & 0x1f; 770 771 d = (ntohl(v6dst->s6_addr32[pbw0]) << pbi0) >> 772 tunnel->ip6rd.relay_prefixlen; 773 774 pbi1 = pbi0 - tunnel->ip6rd.relay_prefixlen; 775 if (pbi1 > 0) 776 d |= ntohl(v6dst->s6_addr32[pbw0 + 1]) >> 777 (32 - pbi1); 778 779 *v4dst = tunnel->ip6rd.relay_prefix | htonl(d); 780 return true; 781 } 782 #else 783 if (v6dst->s6_addr16[0] == htons(0x2002)) { 784 /* 6to4 v6 addr has 16 bits prefix, 32 v4addr, 16 SLA, ... */ 785 memcpy(v4dst, &v6dst->s6_addr16[1], 4); 786 return true; 787 } 788 #endif 789 return false; 790 } 791 792 static inline __be32 try_6rd(struct ip_tunnel *tunnel, 793 const struct in6_addr *v6dst) 794 { 795 __be32 dst = 0; 796 check_6rd(tunnel, v6dst, &dst); 797 return dst; 798 } 799 800 /* 801 * This function assumes it is being called from dev_queue_xmit() 802 * and that skb is filled properly by that function. 803 */ 804 805 static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb, 806 struct net_device *dev) 807 { 808 struct ip_tunnel *tunnel = netdev_priv(dev); 809 const struct iphdr *tiph = &tunnel->parms.iph; 810 const struct ipv6hdr *iph6 = ipv6_hdr(skb); 811 u8 tos = tunnel->parms.iph.tos; 812 __be16 df = tiph->frag_off; 813 struct rtable *rt; /* Route to the other host */ 814 struct net_device *tdev; /* Device to other host */ 815 unsigned int max_headroom; /* The extra header space needed */ 816 __be32 dst = tiph->daddr; 817 struct flowi4 fl4; 818 int mtu; 819 const struct in6_addr *addr6; 820 int addr_type; 821 u8 ttl; 822 int err; 823 824 if (skb->protocol != htons(ETH_P_IPV6)) 825 goto tx_error; 826 827 if (tos == 1) 828 tos = ipv6_get_dsfield(iph6); 829 830 /* ISATAP (RFC4214) - must come before 6to4 */ 831 if (dev->priv_flags & IFF_ISATAP) { 832 struct neighbour *neigh = NULL; 833 bool do_tx_error = false; 834 835 if (skb_dst(skb)) 836 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 837 838 if (neigh == NULL) { 839 net_dbg_ratelimited("nexthop == NULL\n"); 840 goto tx_error; 841 } 842 843 addr6 = (const struct in6_addr *)&neigh->primary_key; 844 addr_type = ipv6_addr_type(addr6); 845 846 if ((addr_type & IPV6_ADDR_UNICAST) && 847 ipv6_addr_is_isatap(addr6)) 848 dst = addr6->s6_addr32[3]; 849 else 850 do_tx_error = true; 851 852 neigh_release(neigh); 853 if (do_tx_error) 854 goto tx_error; 855 } 856 857 if (!dst) 858 dst = try_6rd(tunnel, &iph6->daddr); 859 860 if (!dst) { 861 struct neighbour *neigh = NULL; 862 bool do_tx_error = false; 863 864 if (skb_dst(skb)) 865 neigh = dst_neigh_lookup(skb_dst(skb), &iph6->daddr); 866 867 if (neigh == NULL) { 868 net_dbg_ratelimited("nexthop == NULL\n"); 869 goto tx_error; 870 } 871 872 addr6 = (const struct in6_addr *)&neigh->primary_key; 873 addr_type = ipv6_addr_type(addr6); 874 875 if (addr_type == IPV6_ADDR_ANY) { 876 addr6 = &ipv6_hdr(skb)->daddr; 877 addr_type = ipv6_addr_type(addr6); 878 } 879 880 if ((addr_type & IPV6_ADDR_COMPATv4) != 0) 881 dst = addr6->s6_addr32[3]; 882 else 883 do_tx_error = true; 884 885 neigh_release(neigh); 886 if (do_tx_error) 887 goto tx_error; 888 } 889 890 rt = ip_route_output_ports(tunnel->net, &fl4, NULL, 891 dst, tiph->saddr, 892 0, 0, 893 IPPROTO_IPV6, RT_TOS(tos), 894 tunnel->parms.link); 895 if (IS_ERR(rt)) { 896 dev->stats.tx_carrier_errors++; 897 goto tx_error_icmp; 898 } 899 if (rt->rt_type != RTN_UNICAST) { 900 ip_rt_put(rt); 901 dev->stats.tx_carrier_errors++; 902 goto tx_error_icmp; 903 } 904 tdev = rt->dst.dev; 905 906 if (tdev == dev) { 907 ip_rt_put(rt); 908 dev->stats.collisions++; 909 goto tx_error; 910 } 911 912 if (df) { 913 mtu = dst_mtu(&rt->dst) - sizeof(struct iphdr); 914 915 if (mtu < 68) { 916 dev->stats.collisions++; 917 ip_rt_put(rt); 918 goto tx_error; 919 } 920 921 if (mtu < IPV6_MIN_MTU) { 922 mtu = IPV6_MIN_MTU; 923 df = 0; 924 } 925 926 if (tunnel->parms.iph.daddr && skb_dst(skb)) 927 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 928 929 if (skb->len > mtu && !skb_is_gso(skb)) { 930 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 931 ip_rt_put(rt); 932 goto tx_error; 933 } 934 } 935 936 if (tunnel->err_count > 0) { 937 if (time_before(jiffies, 938 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 939 tunnel->err_count--; 940 dst_link_failure(skb); 941 } else 942 tunnel->err_count = 0; 943 } 944 945 /* 946 * Okay, now see if we can stuff it in the buffer as-is. 947 */ 948 max_headroom = LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr); 949 950 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 951 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 952 struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); 953 if (!new_skb) { 954 ip_rt_put(rt); 955 dev->stats.tx_dropped++; 956 kfree_skb(skb); 957 return NETDEV_TX_OK; 958 } 959 if (skb->sk) 960 skb_set_owner_w(new_skb, skb->sk); 961 dev_kfree_skb(skb); 962 skb = new_skb; 963 iph6 = ipv6_hdr(skb); 964 } 965 ttl = tiph->ttl; 966 if (ttl == 0) 967 ttl = iph6->hop_limit; 968 tos = INET_ECN_encapsulate(tos, ipv6_get_dsfield(iph6)); 969 970 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_SIT); 971 if (IS_ERR(skb)) { 972 ip_rt_put(rt); 973 goto out; 974 } 975 976 err = iptunnel_xmit(rt, skb, fl4.saddr, fl4.daddr, IPPROTO_IPV6, tos, 977 ttl, df, !net_eq(tunnel->net, dev_net(dev))); 978 iptunnel_xmit_stats(err, &dev->stats, dev->tstats); 979 return NETDEV_TX_OK; 980 981 tx_error_icmp: 982 dst_link_failure(skb); 983 tx_error: 984 kfree_skb(skb); 985 out: 986 dev->stats.tx_errors++; 987 return NETDEV_TX_OK; 988 } 989 990 static netdev_tx_t ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev) 991 { 992 struct ip_tunnel *tunnel = netdev_priv(dev); 993 const struct iphdr *tiph = &tunnel->parms.iph; 994 995 skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP); 996 if (IS_ERR(skb)) 997 goto out; 998 999 ip_tunnel_xmit(skb, dev, tiph, IPPROTO_IPIP); 1000 return NETDEV_TX_OK; 1001 out: 1002 dev->stats.tx_errors++; 1003 return NETDEV_TX_OK; 1004 } 1005 1006 static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb, 1007 struct net_device *dev) 1008 { 1009 switch (skb->protocol) { 1010 case htons(ETH_P_IP): 1011 ipip_tunnel_xmit(skb, dev); 1012 break; 1013 case htons(ETH_P_IPV6): 1014 ipip6_tunnel_xmit(skb, dev); 1015 break; 1016 default: 1017 goto tx_err; 1018 } 1019 1020 return NETDEV_TX_OK; 1021 1022 tx_err: 1023 dev->stats.tx_errors++; 1024 kfree_skb(skb); 1025 return NETDEV_TX_OK; 1026 1027 } 1028 1029 static void ipip6_tunnel_bind_dev(struct net_device *dev) 1030 { 1031 struct net_device *tdev = NULL; 1032 struct ip_tunnel *tunnel; 1033 const struct iphdr *iph; 1034 struct flowi4 fl4; 1035 1036 tunnel = netdev_priv(dev); 1037 iph = &tunnel->parms.iph; 1038 1039 if (iph->daddr) { 1040 struct rtable *rt = ip_route_output_ports(tunnel->net, &fl4, 1041 NULL, 1042 iph->daddr, iph->saddr, 1043 0, 0, 1044 IPPROTO_IPV6, 1045 RT_TOS(iph->tos), 1046 tunnel->parms.link); 1047 1048 if (!IS_ERR(rt)) { 1049 tdev = rt->dst.dev; 1050 ip_rt_put(rt); 1051 } 1052 dev->flags |= IFF_POINTOPOINT; 1053 } 1054 1055 if (!tdev && tunnel->parms.link) 1056 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 1057 1058 if (tdev) { 1059 dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr); 1060 dev->mtu = tdev->mtu - sizeof(struct iphdr); 1061 if (dev->mtu < IPV6_MIN_MTU) 1062 dev->mtu = IPV6_MIN_MTU; 1063 } 1064 dev->iflink = tunnel->parms.link; 1065 } 1066 1067 static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p) 1068 { 1069 struct net *net = t->net; 1070 struct sit_net *sitn = net_generic(net, sit_net_id); 1071 1072 ipip6_tunnel_unlink(sitn, t); 1073 synchronize_net(); 1074 t->parms.iph.saddr = p->iph.saddr; 1075 t->parms.iph.daddr = p->iph.daddr; 1076 memcpy(t->dev->dev_addr, &p->iph.saddr, 4); 1077 memcpy(t->dev->broadcast, &p->iph.daddr, 4); 1078 ipip6_tunnel_link(sitn, t); 1079 t->parms.iph.ttl = p->iph.ttl; 1080 t->parms.iph.tos = p->iph.tos; 1081 if (t->parms.link != p->link) { 1082 t->parms.link = p->link; 1083 ipip6_tunnel_bind_dev(t->dev); 1084 } 1085 netdev_state_change(t->dev); 1086 } 1087 1088 #ifdef CONFIG_IPV6_SIT_6RD 1089 static int ipip6_tunnel_update_6rd(struct ip_tunnel *t, 1090 struct ip_tunnel_6rd *ip6rd) 1091 { 1092 struct in6_addr prefix; 1093 __be32 relay_prefix; 1094 1095 if (ip6rd->relay_prefixlen > 32 || 1096 ip6rd->prefixlen + (32 - ip6rd->relay_prefixlen) > 64) 1097 return -EINVAL; 1098 1099 ipv6_addr_prefix(&prefix, &ip6rd->prefix, ip6rd->prefixlen); 1100 if (!ipv6_addr_equal(&prefix, &ip6rd->prefix)) 1101 return -EINVAL; 1102 if (ip6rd->relay_prefixlen) 1103 relay_prefix = ip6rd->relay_prefix & 1104 htonl(0xffffffffUL << 1105 (32 - ip6rd->relay_prefixlen)); 1106 else 1107 relay_prefix = 0; 1108 if (relay_prefix != ip6rd->relay_prefix) 1109 return -EINVAL; 1110 1111 t->ip6rd.prefix = prefix; 1112 t->ip6rd.relay_prefix = relay_prefix; 1113 t->ip6rd.prefixlen = ip6rd->prefixlen; 1114 t->ip6rd.relay_prefixlen = ip6rd->relay_prefixlen; 1115 netdev_state_change(t->dev); 1116 return 0; 1117 } 1118 #endif 1119 1120 static int 1121 ipip6_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd) 1122 { 1123 int err = 0; 1124 struct ip_tunnel_parm p; 1125 struct ip_tunnel_prl prl; 1126 struct ip_tunnel *t; 1127 struct net *net = dev_net(dev); 1128 struct sit_net *sitn = net_generic(net, sit_net_id); 1129 #ifdef CONFIG_IPV6_SIT_6RD 1130 struct ip_tunnel_6rd ip6rd; 1131 #endif 1132 1133 switch (cmd) { 1134 case SIOCGETTUNNEL: 1135 #ifdef CONFIG_IPV6_SIT_6RD 1136 case SIOCGET6RD: 1137 #endif 1138 t = NULL; 1139 if (dev == sitn->fb_tunnel_dev) { 1140 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 1141 err = -EFAULT; 1142 break; 1143 } 1144 t = ipip6_tunnel_locate(net, &p, 0); 1145 } 1146 if (t == NULL) 1147 t = netdev_priv(dev); 1148 1149 err = -EFAULT; 1150 if (cmd == SIOCGETTUNNEL) { 1151 memcpy(&p, &t->parms, sizeof(p)); 1152 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, 1153 sizeof(p))) 1154 goto done; 1155 #ifdef CONFIG_IPV6_SIT_6RD 1156 } else { 1157 ip6rd.prefix = t->ip6rd.prefix; 1158 ip6rd.relay_prefix = t->ip6rd.relay_prefix; 1159 ip6rd.prefixlen = t->ip6rd.prefixlen; 1160 ip6rd.relay_prefixlen = t->ip6rd.relay_prefixlen; 1161 if (copy_to_user(ifr->ifr_ifru.ifru_data, &ip6rd, 1162 sizeof(ip6rd))) 1163 goto done; 1164 #endif 1165 } 1166 err = 0; 1167 break; 1168 1169 case SIOCADDTUNNEL: 1170 case SIOCCHGTUNNEL: 1171 err = -EPERM; 1172 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1173 goto done; 1174 1175 err = -EFAULT; 1176 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1177 goto done; 1178 1179 err = -EINVAL; 1180 if (p.iph.protocol != IPPROTO_IPV6 && 1181 p.iph.protocol != IPPROTO_IPIP && 1182 p.iph.protocol != 0) 1183 goto done; 1184 if (p.iph.version != 4 || 1185 p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF))) 1186 goto done; 1187 if (p.iph.ttl) 1188 p.iph.frag_off |= htons(IP_DF); 1189 1190 t = ipip6_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL); 1191 1192 if (dev != sitn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 1193 if (t != NULL) { 1194 if (t->dev != dev) { 1195 err = -EEXIST; 1196 break; 1197 } 1198 } else { 1199 if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) || 1200 (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) { 1201 err = -EINVAL; 1202 break; 1203 } 1204 t = netdev_priv(dev); 1205 } 1206 1207 ipip6_tunnel_update(t, &p); 1208 } 1209 1210 if (t) { 1211 err = 0; 1212 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p))) 1213 err = -EFAULT; 1214 } else 1215 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1216 break; 1217 1218 case SIOCDELTUNNEL: 1219 err = -EPERM; 1220 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1221 goto done; 1222 1223 if (dev == sitn->fb_tunnel_dev) { 1224 err = -EFAULT; 1225 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1226 goto done; 1227 err = -ENOENT; 1228 if ((t = ipip6_tunnel_locate(net, &p, 0)) == NULL) 1229 goto done; 1230 err = -EPERM; 1231 if (t == netdev_priv(sitn->fb_tunnel_dev)) 1232 goto done; 1233 dev = t->dev; 1234 } 1235 unregister_netdevice(dev); 1236 err = 0; 1237 break; 1238 1239 case SIOCGETPRL: 1240 err = -EINVAL; 1241 if (dev == sitn->fb_tunnel_dev) 1242 goto done; 1243 err = -ENOENT; 1244 if (!(t = netdev_priv(dev))) 1245 goto done; 1246 err = ipip6_tunnel_get_prl(t, ifr->ifr_ifru.ifru_data); 1247 break; 1248 1249 case SIOCADDPRL: 1250 case SIOCDELPRL: 1251 case SIOCCHGPRL: 1252 err = -EPERM; 1253 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1254 goto done; 1255 err = -EINVAL; 1256 if (dev == sitn->fb_tunnel_dev) 1257 goto done; 1258 err = -EFAULT; 1259 if (copy_from_user(&prl, ifr->ifr_ifru.ifru_data, sizeof(prl))) 1260 goto done; 1261 err = -ENOENT; 1262 if (!(t = netdev_priv(dev))) 1263 goto done; 1264 1265 switch (cmd) { 1266 case SIOCDELPRL: 1267 err = ipip6_tunnel_del_prl(t, &prl); 1268 break; 1269 case SIOCADDPRL: 1270 case SIOCCHGPRL: 1271 err = ipip6_tunnel_add_prl(t, &prl, cmd == SIOCCHGPRL); 1272 break; 1273 } 1274 netdev_state_change(dev); 1275 break; 1276 1277 #ifdef CONFIG_IPV6_SIT_6RD 1278 case SIOCADD6RD: 1279 case SIOCCHG6RD: 1280 case SIOCDEL6RD: 1281 err = -EPERM; 1282 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1283 goto done; 1284 1285 err = -EFAULT; 1286 if (copy_from_user(&ip6rd, ifr->ifr_ifru.ifru_data, 1287 sizeof(ip6rd))) 1288 goto done; 1289 1290 t = netdev_priv(dev); 1291 1292 if (cmd != SIOCDEL6RD) { 1293 err = ipip6_tunnel_update_6rd(t, &ip6rd); 1294 if (err < 0) 1295 goto done; 1296 } else 1297 ipip6_tunnel_clone_6rd(dev, sitn); 1298 1299 err = 0; 1300 break; 1301 #endif 1302 1303 default: 1304 err = -EINVAL; 1305 } 1306 1307 done: 1308 return err; 1309 } 1310 1311 static int ipip6_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1312 { 1313 if (new_mtu < IPV6_MIN_MTU || new_mtu > 0xFFF8 - sizeof(struct iphdr)) 1314 return -EINVAL; 1315 dev->mtu = new_mtu; 1316 return 0; 1317 } 1318 1319 static const struct net_device_ops ipip6_netdev_ops = { 1320 .ndo_uninit = ipip6_tunnel_uninit, 1321 .ndo_start_xmit = sit_tunnel_xmit, 1322 .ndo_do_ioctl = ipip6_tunnel_ioctl, 1323 .ndo_change_mtu = ipip6_tunnel_change_mtu, 1324 .ndo_get_stats64 = ip_tunnel_get_stats64, 1325 }; 1326 1327 static void ipip6_dev_free(struct net_device *dev) 1328 { 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 int i; 1360 1361 tunnel->dev = dev; 1362 tunnel->net = dev_net(dev); 1363 1364 memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4); 1365 memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4); 1366 1367 ipip6_tunnel_bind_dev(dev); 1368 dev->tstats = alloc_percpu(struct pcpu_sw_netstats); 1369 if (!dev->tstats) 1370 return -ENOMEM; 1371 1372 for_each_possible_cpu(i) { 1373 struct pcpu_sw_netstats *ipip6_tunnel_stats; 1374 ipip6_tunnel_stats = per_cpu_ptr(dev->tstats, i); 1375 u64_stats_init(&ipip6_tunnel_stats->syncp); 1376 } 1377 1378 return 0; 1379 } 1380 1381 static int __net_init ipip6_fb_tunnel_init(struct net_device *dev) 1382 { 1383 struct ip_tunnel *tunnel = netdev_priv(dev); 1384 struct iphdr *iph = &tunnel->parms.iph; 1385 struct net *net = dev_net(dev); 1386 struct sit_net *sitn = net_generic(net, sit_net_id); 1387 int i; 1388 1389 tunnel->dev = dev; 1390 tunnel->net = dev_net(dev); 1391 strcpy(tunnel->parms.name, dev->name); 1392 1393 iph->version = 4; 1394 iph->protocol = IPPROTO_IPV6; 1395 iph->ihl = 5; 1396 iph->ttl = 64; 1397 1398 dev->tstats = alloc_percpu(struct pcpu_sw_netstats); 1399 if (!dev->tstats) 1400 return -ENOMEM; 1401 1402 for_each_possible_cpu(i) { 1403 struct pcpu_sw_netstats *ipip6_fb_stats; 1404 ipip6_fb_stats = per_cpu_ptr(dev->tstats, i); 1405 u64_stats_init(&ipip6_fb_stats->syncp); 1406 } 1407 1408 dev_hold(dev); 1409 rcu_assign_pointer(sitn->tunnels_wc[0], tunnel); 1410 return 0; 1411 } 1412 1413 static int ipip6_validate(struct nlattr *tb[], struct nlattr *data[]) 1414 { 1415 u8 proto; 1416 1417 if (!data || !data[IFLA_IPTUN_PROTO]) 1418 return 0; 1419 1420 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1421 if (proto != IPPROTO_IPV6 && 1422 proto != IPPROTO_IPIP && 1423 proto != 0) 1424 return -EINVAL; 1425 1426 return 0; 1427 } 1428 1429 static void ipip6_netlink_parms(struct nlattr *data[], 1430 struct ip_tunnel_parm *parms) 1431 { 1432 memset(parms, 0, sizeof(*parms)); 1433 1434 parms->iph.version = 4; 1435 parms->iph.protocol = IPPROTO_IPV6; 1436 parms->iph.ihl = 5; 1437 parms->iph.ttl = 64; 1438 1439 if (!data) 1440 return; 1441 1442 if (data[IFLA_IPTUN_LINK]) 1443 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1444 1445 if (data[IFLA_IPTUN_LOCAL]) 1446 parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]); 1447 1448 if (data[IFLA_IPTUN_REMOTE]) 1449 parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]); 1450 1451 if (data[IFLA_IPTUN_TTL]) { 1452 parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]); 1453 if (parms->iph.ttl) 1454 parms->iph.frag_off = htons(IP_DF); 1455 } 1456 1457 if (data[IFLA_IPTUN_TOS]) 1458 parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]); 1459 1460 if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC])) 1461 parms->iph.frag_off = htons(IP_DF); 1462 1463 if (data[IFLA_IPTUN_FLAGS]) 1464 parms->i_flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]); 1465 1466 if (data[IFLA_IPTUN_PROTO]) 1467 parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1468 1469 } 1470 1471 #ifdef CONFIG_IPV6_SIT_6RD 1472 /* This function returns true when 6RD attributes are present in the nl msg */ 1473 static bool ipip6_netlink_6rd_parms(struct nlattr *data[], 1474 struct ip_tunnel_6rd *ip6rd) 1475 { 1476 bool ret = false; 1477 memset(ip6rd, 0, sizeof(*ip6rd)); 1478 1479 if (!data) 1480 return ret; 1481 1482 if (data[IFLA_IPTUN_6RD_PREFIX]) { 1483 ret = true; 1484 nla_memcpy(&ip6rd->prefix, data[IFLA_IPTUN_6RD_PREFIX], 1485 sizeof(struct in6_addr)); 1486 } 1487 1488 if (data[IFLA_IPTUN_6RD_RELAY_PREFIX]) { 1489 ret = true; 1490 ip6rd->relay_prefix = 1491 nla_get_be32(data[IFLA_IPTUN_6RD_RELAY_PREFIX]); 1492 } 1493 1494 if (data[IFLA_IPTUN_6RD_PREFIXLEN]) { 1495 ret = true; 1496 ip6rd->prefixlen = nla_get_u16(data[IFLA_IPTUN_6RD_PREFIXLEN]); 1497 } 1498 1499 if (data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]) { 1500 ret = true; 1501 ip6rd->relay_prefixlen = 1502 nla_get_u16(data[IFLA_IPTUN_6RD_RELAY_PREFIXLEN]); 1503 } 1504 1505 return ret; 1506 } 1507 #endif 1508 1509 static int ipip6_newlink(struct net *src_net, struct net_device *dev, 1510 struct nlattr *tb[], struct nlattr *data[]) 1511 { 1512 struct net *net = dev_net(dev); 1513 struct ip_tunnel *nt; 1514 #ifdef CONFIG_IPV6_SIT_6RD 1515 struct ip_tunnel_6rd ip6rd; 1516 #endif 1517 int err; 1518 1519 nt = netdev_priv(dev); 1520 ipip6_netlink_parms(data, &nt->parms); 1521 1522 if (ipip6_tunnel_locate(net, &nt->parms, 0)) 1523 return -EEXIST; 1524 1525 err = ipip6_tunnel_create(dev); 1526 if (err < 0) 1527 return err; 1528 1529 #ifdef CONFIG_IPV6_SIT_6RD 1530 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1531 err = ipip6_tunnel_update_6rd(nt, &ip6rd); 1532 #endif 1533 1534 return err; 1535 } 1536 1537 static int ipip6_changelink(struct net_device *dev, struct nlattr *tb[], 1538 struct nlattr *data[]) 1539 { 1540 struct ip_tunnel *t = netdev_priv(dev); 1541 struct ip_tunnel_parm p; 1542 struct net *net = t->net; 1543 struct sit_net *sitn = net_generic(net, sit_net_id); 1544 #ifdef CONFIG_IPV6_SIT_6RD 1545 struct ip_tunnel_6rd ip6rd; 1546 #endif 1547 1548 if (dev == sitn->fb_tunnel_dev) 1549 return -EINVAL; 1550 1551 ipip6_netlink_parms(data, &p); 1552 1553 if (((dev->flags & IFF_POINTOPOINT) && !p.iph.daddr) || 1554 (!(dev->flags & IFF_POINTOPOINT) && p.iph.daddr)) 1555 return -EINVAL; 1556 1557 t = ipip6_tunnel_locate(net, &p, 0); 1558 1559 if (t) { 1560 if (t->dev != dev) 1561 return -EEXIST; 1562 } else 1563 t = netdev_priv(dev); 1564 1565 ipip6_tunnel_update(t, &p); 1566 1567 #ifdef CONFIG_IPV6_SIT_6RD 1568 if (ipip6_netlink_6rd_parms(data, &ip6rd)) 1569 return ipip6_tunnel_update_6rd(t, &ip6rd); 1570 #endif 1571 1572 return 0; 1573 } 1574 1575 static size_t ipip6_get_size(const struct net_device *dev) 1576 { 1577 return 1578 /* IFLA_IPTUN_LINK */ 1579 nla_total_size(4) + 1580 /* IFLA_IPTUN_LOCAL */ 1581 nla_total_size(4) + 1582 /* IFLA_IPTUN_REMOTE */ 1583 nla_total_size(4) + 1584 /* IFLA_IPTUN_TTL */ 1585 nla_total_size(1) + 1586 /* IFLA_IPTUN_TOS */ 1587 nla_total_size(1) + 1588 /* IFLA_IPTUN_PMTUDISC */ 1589 nla_total_size(1) + 1590 /* IFLA_IPTUN_FLAGS */ 1591 nla_total_size(2) + 1592 /* IFLA_IPTUN_PROTO */ 1593 nla_total_size(1) + 1594 #ifdef CONFIG_IPV6_SIT_6RD 1595 /* IFLA_IPTUN_6RD_PREFIX */ 1596 nla_total_size(sizeof(struct in6_addr)) + 1597 /* IFLA_IPTUN_6RD_RELAY_PREFIX */ 1598 nla_total_size(4) + 1599 /* IFLA_IPTUN_6RD_PREFIXLEN */ 1600 nla_total_size(2) + 1601 /* IFLA_IPTUN_6RD_RELAY_PREFIXLEN */ 1602 nla_total_size(2) + 1603 #endif 1604 0; 1605 } 1606 1607 static int ipip6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1608 { 1609 struct ip_tunnel *tunnel = netdev_priv(dev); 1610 struct ip_tunnel_parm *parm = &tunnel->parms; 1611 1612 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1613 nla_put_be32(skb, IFLA_IPTUN_LOCAL, parm->iph.saddr) || 1614 nla_put_be32(skb, IFLA_IPTUN_REMOTE, parm->iph.daddr) || 1615 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->iph.ttl) || 1616 nla_put_u8(skb, IFLA_IPTUN_TOS, parm->iph.tos) || 1617 nla_put_u8(skb, IFLA_IPTUN_PMTUDISC, 1618 !!(parm->iph.frag_off & htons(IP_DF))) || 1619 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->iph.protocol) || 1620 nla_put_be16(skb, IFLA_IPTUN_FLAGS, parm->i_flags)) 1621 goto nla_put_failure; 1622 1623 #ifdef CONFIG_IPV6_SIT_6RD 1624 if (nla_put(skb, IFLA_IPTUN_6RD_PREFIX, sizeof(struct in6_addr), 1625 &tunnel->ip6rd.prefix) || 1626 nla_put_be32(skb, IFLA_IPTUN_6RD_RELAY_PREFIX, 1627 tunnel->ip6rd.relay_prefix) || 1628 nla_put_u16(skb, IFLA_IPTUN_6RD_PREFIXLEN, 1629 tunnel->ip6rd.prefixlen) || 1630 nla_put_u16(skb, IFLA_IPTUN_6RD_RELAY_PREFIXLEN, 1631 tunnel->ip6rd.relay_prefixlen)) 1632 goto nla_put_failure; 1633 #endif 1634 1635 return 0; 1636 1637 nla_put_failure: 1638 return -EMSGSIZE; 1639 } 1640 1641 static const struct nla_policy ipip6_policy[IFLA_IPTUN_MAX + 1] = { 1642 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1643 [IFLA_IPTUN_LOCAL] = { .type = NLA_U32 }, 1644 [IFLA_IPTUN_REMOTE] = { .type = NLA_U32 }, 1645 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1646 [IFLA_IPTUN_TOS] = { .type = NLA_U8 }, 1647 [IFLA_IPTUN_PMTUDISC] = { .type = NLA_U8 }, 1648 [IFLA_IPTUN_FLAGS] = { .type = NLA_U16 }, 1649 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1650 #ifdef CONFIG_IPV6_SIT_6RD 1651 [IFLA_IPTUN_6RD_PREFIX] = { .len = sizeof(struct in6_addr) }, 1652 [IFLA_IPTUN_6RD_RELAY_PREFIX] = { .type = NLA_U32 }, 1653 [IFLA_IPTUN_6RD_PREFIXLEN] = { .type = NLA_U16 }, 1654 [IFLA_IPTUN_6RD_RELAY_PREFIXLEN] = { .type = NLA_U16 }, 1655 #endif 1656 }; 1657 1658 static void ipip6_dellink(struct net_device *dev, struct list_head *head) 1659 { 1660 struct net *net = dev_net(dev); 1661 struct sit_net *sitn = net_generic(net, sit_net_id); 1662 1663 if (dev != sitn->fb_tunnel_dev) 1664 unregister_netdevice_queue(dev, head); 1665 } 1666 1667 static struct rtnl_link_ops sit_link_ops __read_mostly = { 1668 .kind = "sit", 1669 .maxtype = IFLA_IPTUN_MAX, 1670 .policy = ipip6_policy, 1671 .priv_size = sizeof(struct ip_tunnel), 1672 .setup = ipip6_tunnel_setup, 1673 .validate = ipip6_validate, 1674 .newlink = ipip6_newlink, 1675 .changelink = ipip6_changelink, 1676 .get_size = ipip6_get_size, 1677 .fill_info = ipip6_fill_info, 1678 .dellink = ipip6_dellink, 1679 }; 1680 1681 static struct xfrm_tunnel sit_handler __read_mostly = { 1682 .handler = ipip6_rcv, 1683 .err_handler = ipip6_err, 1684 .priority = 1, 1685 }; 1686 1687 static struct xfrm_tunnel ipip_handler __read_mostly = { 1688 .handler = ipip_rcv, 1689 .err_handler = ipip6_err, 1690 .priority = 2, 1691 }; 1692 1693 static void __net_exit sit_destroy_tunnels(struct net *net, 1694 struct list_head *head) 1695 { 1696 struct sit_net *sitn = net_generic(net, sit_net_id); 1697 struct net_device *dev, *aux; 1698 int prio; 1699 1700 for_each_netdev_safe(net, dev, aux) 1701 if (dev->rtnl_link_ops == &sit_link_ops) 1702 unregister_netdevice_queue(dev, head); 1703 1704 for (prio = 1; prio < 4; prio++) { 1705 int h; 1706 for (h = 0; h < HASH_SIZE; h++) { 1707 struct ip_tunnel *t; 1708 1709 t = rtnl_dereference(sitn->tunnels[prio][h]); 1710 while (t != NULL) { 1711 /* If dev is in the same netns, it has already 1712 * been added to the list by the previous loop. 1713 */ 1714 if (!net_eq(dev_net(t->dev), net)) 1715 unregister_netdevice_queue(t->dev, 1716 head); 1717 t = rtnl_dereference(t->next); 1718 } 1719 } 1720 } 1721 } 1722 1723 static int __net_init sit_init_net(struct net *net) 1724 { 1725 struct sit_net *sitn = net_generic(net, sit_net_id); 1726 struct ip_tunnel *t; 1727 int err; 1728 1729 sitn->tunnels[0] = sitn->tunnels_wc; 1730 sitn->tunnels[1] = sitn->tunnels_l; 1731 sitn->tunnels[2] = sitn->tunnels_r; 1732 sitn->tunnels[3] = sitn->tunnels_r_l; 1733 1734 sitn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "sit0", 1735 ipip6_tunnel_setup); 1736 if (!sitn->fb_tunnel_dev) { 1737 err = -ENOMEM; 1738 goto err_alloc_dev; 1739 } 1740 dev_net_set(sitn->fb_tunnel_dev, net); 1741 sitn->fb_tunnel_dev->rtnl_link_ops = &sit_link_ops; 1742 /* FB netdevice is special: we have one, and only one per netns. 1743 * Allowing to move it to another netns is clearly unsafe. 1744 */ 1745 sitn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1746 1747 err = ipip6_fb_tunnel_init(sitn->fb_tunnel_dev); 1748 if (err) 1749 goto err_dev_free; 1750 1751 ipip6_tunnel_clone_6rd(sitn->fb_tunnel_dev, sitn); 1752 1753 if ((err = register_netdev(sitn->fb_tunnel_dev))) 1754 goto err_reg_dev; 1755 1756 t = netdev_priv(sitn->fb_tunnel_dev); 1757 1758 strcpy(t->parms.name, sitn->fb_tunnel_dev->name); 1759 return 0; 1760 1761 err_reg_dev: 1762 dev_put(sitn->fb_tunnel_dev); 1763 err_dev_free: 1764 ipip6_dev_free(sitn->fb_tunnel_dev); 1765 err_alloc_dev: 1766 return err; 1767 } 1768 1769 static void __net_exit sit_exit_net(struct net *net) 1770 { 1771 LIST_HEAD(list); 1772 1773 rtnl_lock(); 1774 sit_destroy_tunnels(net, &list); 1775 unregister_netdevice_many(&list); 1776 rtnl_unlock(); 1777 } 1778 1779 static struct pernet_operations sit_net_ops = { 1780 .init = sit_init_net, 1781 .exit = sit_exit_net, 1782 .id = &sit_net_id, 1783 .size = sizeof(struct sit_net), 1784 }; 1785 1786 static void __exit sit_cleanup(void) 1787 { 1788 rtnl_link_unregister(&sit_link_ops); 1789 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1790 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1791 1792 unregister_pernet_device(&sit_net_ops); 1793 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 1794 } 1795 1796 static int __init sit_init(void) 1797 { 1798 int err; 1799 1800 pr_info("IPv6 over IPv4 tunneling driver\n"); 1801 1802 err = register_pernet_device(&sit_net_ops); 1803 if (err < 0) 1804 return err; 1805 err = xfrm4_tunnel_register(&sit_handler, AF_INET6); 1806 if (err < 0) { 1807 pr_info("%s: can't register ip6ip4\n", __func__); 1808 goto xfrm_tunnel_failed; 1809 } 1810 err = xfrm4_tunnel_register(&ipip_handler, AF_INET); 1811 if (err < 0) { 1812 pr_info("%s: can't register ip4ip4\n", __func__); 1813 goto xfrm_tunnel4_failed; 1814 } 1815 err = rtnl_link_register(&sit_link_ops); 1816 if (err < 0) 1817 goto rtnl_link_failed; 1818 1819 out: 1820 return err; 1821 1822 rtnl_link_failed: 1823 xfrm4_tunnel_deregister(&ipip_handler, AF_INET); 1824 xfrm_tunnel4_failed: 1825 xfrm4_tunnel_deregister(&sit_handler, AF_INET6); 1826 xfrm_tunnel_failed: 1827 unregister_pernet_device(&sit_net_ops); 1828 goto out; 1829 } 1830 1831 module_init(sit_init); 1832 module_exit(sit_cleanup); 1833 MODULE_LICENSE("GPL"); 1834 MODULE_ALIAS_NETDEV("sit0"); 1835