1 /* 2 * IPv6 tunneling device 3 * Linux INET6 implementation 4 * 5 * Authors: 6 * Ville Nuorvala <vnuorval@tcs.hut.fi> 7 * Yasuyuki Kozakai <kozakai@linux-ipv6.org> 8 * 9 * Based on: 10 * linux/net/ipv6/sit.c and linux/net/ipv4/ipip.c 11 * 12 * RFC 2473 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License 16 * as published by the Free Software Foundation; either version 17 * 2 of the License, or (at your option) any later version. 18 * 19 */ 20 21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 22 23 #include <linux/module.h> 24 #include <linux/capability.h> 25 #include <linux/errno.h> 26 #include <linux/types.h> 27 #include <linux/sockios.h> 28 #include <linux/icmp.h> 29 #include <linux/if.h> 30 #include <linux/in.h> 31 #include <linux/ip.h> 32 #include <linux/if_tunnel.h> 33 #include <linux/net.h> 34 #include <linux/in6.h> 35 #include <linux/netdevice.h> 36 #include <linux/if_arp.h> 37 #include <linux/icmpv6.h> 38 #include <linux/init.h> 39 #include <linux/route.h> 40 #include <linux/rtnetlink.h> 41 #include <linux/netfilter_ipv6.h> 42 #include <linux/slab.h> 43 #include <linux/hash.h> 44 45 #include <asm/uaccess.h> 46 #include <linux/atomic.h> 47 48 #include <net/icmp.h> 49 #include <net/ip.h> 50 #include <net/ip_tunnels.h> 51 #include <net/ipv6.h> 52 #include <net/ip6_route.h> 53 #include <net/addrconf.h> 54 #include <net/ip6_tunnel.h> 55 #include <net/xfrm.h> 56 #include <net/dsfield.h> 57 #include <net/inet_ecn.h> 58 #include <net/net_namespace.h> 59 #include <net/netns/generic.h> 60 61 MODULE_AUTHOR("Ville Nuorvala"); 62 MODULE_DESCRIPTION("IPv6 tunneling device"); 63 MODULE_LICENSE("GPL"); 64 MODULE_ALIAS_NETDEV("ip6tnl0"); 65 66 #ifdef IP6_TNL_DEBUG 67 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__) 68 #else 69 #define IP6_TNL_TRACE(x...) do {;} while(0) 70 #endif 71 72 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 73 #define IPV6_TCLASS_SHIFT 20 74 75 #define HASH_SIZE_SHIFT 5 76 #define HASH_SIZE (1 << HASH_SIZE_SHIFT) 77 78 static bool log_ecn_error = true; 79 module_param(log_ecn_error, bool, 0644); 80 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 81 82 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 83 { 84 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 85 86 return hash_32(hash, HASH_SIZE_SHIFT); 87 } 88 89 static int ip6_tnl_dev_init(struct net_device *dev); 90 static void ip6_tnl_dev_setup(struct net_device *dev); 91 static struct rtnl_link_ops ip6_link_ops __read_mostly; 92 93 static int ip6_tnl_net_id __read_mostly; 94 struct ip6_tnl_net { 95 /* the IPv6 tunnel fallback device */ 96 struct net_device *fb_tnl_dev; 97 /* lists for storing tunnels in use */ 98 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE]; 99 struct ip6_tnl __rcu *tnls_wc[1]; 100 struct ip6_tnl __rcu **tnls[2]; 101 }; 102 103 static struct net_device_stats *ip6_get_stats(struct net_device *dev) 104 { 105 struct pcpu_tstats sum = { 0 }; 106 int i; 107 108 for_each_possible_cpu(i) { 109 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 110 111 sum.rx_packets += tstats->rx_packets; 112 sum.rx_bytes += tstats->rx_bytes; 113 sum.tx_packets += tstats->tx_packets; 114 sum.tx_bytes += tstats->tx_bytes; 115 } 116 dev->stats.rx_packets = sum.rx_packets; 117 dev->stats.rx_bytes = sum.rx_bytes; 118 dev->stats.tx_packets = sum.tx_packets; 119 dev->stats.tx_bytes = sum.tx_bytes; 120 return &dev->stats; 121 } 122 123 /* 124 * Locking : hash tables are protected by RCU and RTNL 125 */ 126 127 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 128 { 129 struct dst_entry *dst = t->dst_cache; 130 131 if (dst && dst->obsolete && 132 dst->ops->check(dst, t->dst_cookie) == NULL) { 133 t->dst_cache = NULL; 134 dst_release(dst); 135 return NULL; 136 } 137 138 return dst; 139 } 140 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check); 141 142 void ip6_tnl_dst_reset(struct ip6_tnl *t) 143 { 144 dst_release(t->dst_cache); 145 t->dst_cache = NULL; 146 } 147 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset); 148 149 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 150 { 151 struct rt6_info *rt = (struct rt6_info *) dst; 152 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 153 dst_release(t->dst_cache); 154 t->dst_cache = dst; 155 } 156 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store); 157 158 /** 159 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses 160 * @remote: the address of the tunnel exit-point 161 * @local: the address of the tunnel entry-point 162 * 163 * Return: 164 * tunnel matching given end-points if found, 165 * else fallback tunnel if its device is up, 166 * else %NULL 167 **/ 168 169 #define for_each_ip6_tunnel_rcu(start) \ 170 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 171 172 static struct ip6_tnl * 173 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local) 174 { 175 unsigned int hash = HASH(remote, local); 176 struct ip6_tnl *t; 177 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 178 179 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 180 if (ipv6_addr_equal(local, &t->parms.laddr) && 181 ipv6_addr_equal(remote, &t->parms.raddr) && 182 (t->dev->flags & IFF_UP)) 183 return t; 184 } 185 t = rcu_dereference(ip6n->tnls_wc[0]); 186 if (t && (t->dev->flags & IFF_UP)) 187 return t; 188 189 return NULL; 190 } 191 192 /** 193 * ip6_tnl_bucket - get head of list matching given tunnel parameters 194 * @p: parameters containing tunnel end-points 195 * 196 * Description: 197 * ip6_tnl_bucket() returns the head of the list matching the 198 * &struct in6_addr entries laddr and raddr in @p. 199 * 200 * Return: head of IPv6 tunnel list 201 **/ 202 203 static struct ip6_tnl __rcu ** 204 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p) 205 { 206 const struct in6_addr *remote = &p->raddr; 207 const struct in6_addr *local = &p->laddr; 208 unsigned int h = 0; 209 int prio = 0; 210 211 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 212 prio = 1; 213 h = HASH(remote, local); 214 } 215 return &ip6n->tnls[prio][h]; 216 } 217 218 /** 219 * ip6_tnl_link - add tunnel to hash table 220 * @t: tunnel to be added 221 **/ 222 223 static void 224 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 225 { 226 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); 227 228 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 229 rcu_assign_pointer(*tp, t); 230 } 231 232 /** 233 * ip6_tnl_unlink - remove tunnel from hash table 234 * @t: tunnel to be removed 235 **/ 236 237 static void 238 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 239 { 240 struct ip6_tnl __rcu **tp; 241 struct ip6_tnl *iter; 242 243 for (tp = ip6_tnl_bucket(ip6n, &t->parms); 244 (iter = rtnl_dereference(*tp)) != NULL; 245 tp = &iter->next) { 246 if (t == iter) { 247 rcu_assign_pointer(*tp, t->next); 248 break; 249 } 250 } 251 } 252 253 static void ip6_dev_free(struct net_device *dev) 254 { 255 free_percpu(dev->tstats); 256 free_netdev(dev); 257 } 258 259 static int ip6_tnl_create2(struct net_device *dev) 260 { 261 struct ip6_tnl *t = netdev_priv(dev); 262 struct net *net = dev_net(dev); 263 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 264 int err; 265 266 t = netdev_priv(dev); 267 err = ip6_tnl_dev_init(dev); 268 if (err < 0) 269 goto out; 270 271 err = register_netdevice(dev); 272 if (err < 0) 273 goto out; 274 275 strcpy(t->parms.name, dev->name); 276 dev->rtnl_link_ops = &ip6_link_ops; 277 278 dev_hold(dev); 279 ip6_tnl_link(ip6n, t); 280 return 0; 281 282 out: 283 return err; 284 } 285 286 /** 287 * ip6_tnl_create - create a new tunnel 288 * @p: tunnel parameters 289 * @pt: pointer to new tunnel 290 * 291 * Description: 292 * Create tunnel matching given parameters. 293 * 294 * Return: 295 * created tunnel or NULL 296 **/ 297 298 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 299 { 300 struct net_device *dev; 301 struct ip6_tnl *t; 302 char name[IFNAMSIZ]; 303 int err; 304 305 if (p->name[0]) 306 strlcpy(name, p->name, IFNAMSIZ); 307 else 308 sprintf(name, "ip6tnl%%d"); 309 310 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); 311 if (dev == NULL) 312 goto failed; 313 314 dev_net_set(dev, net); 315 316 t = netdev_priv(dev); 317 t->parms = *p; 318 err = ip6_tnl_create2(dev); 319 if (err < 0) 320 goto failed_free; 321 322 return t; 323 324 failed_free: 325 ip6_dev_free(dev); 326 failed: 327 return NULL; 328 } 329 330 /** 331 * ip6_tnl_locate - find or create tunnel matching given parameters 332 * @p: tunnel parameters 333 * @create: != 0 if allowed to create new tunnel if no match found 334 * 335 * Description: 336 * ip6_tnl_locate() first tries to locate an existing tunnel 337 * based on @parms. If this is unsuccessful, but @create is set a new 338 * tunnel device is created and registered for use. 339 * 340 * Return: 341 * matching tunnel or NULL 342 **/ 343 344 static struct ip6_tnl *ip6_tnl_locate(struct net *net, 345 struct __ip6_tnl_parm *p, int create) 346 { 347 const struct in6_addr *remote = &p->raddr; 348 const struct in6_addr *local = &p->laddr; 349 struct ip6_tnl __rcu **tp; 350 struct ip6_tnl *t; 351 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 352 353 for (tp = ip6_tnl_bucket(ip6n, p); 354 (t = rtnl_dereference(*tp)) != NULL; 355 tp = &t->next) { 356 if (ipv6_addr_equal(local, &t->parms.laddr) && 357 ipv6_addr_equal(remote, &t->parms.raddr)) 358 return t; 359 } 360 if (!create) 361 return NULL; 362 return ip6_tnl_create(net, p); 363 } 364 365 /** 366 * ip6_tnl_dev_uninit - tunnel device uninitializer 367 * @dev: the device to be destroyed 368 * 369 * Description: 370 * ip6_tnl_dev_uninit() removes tunnel from its list 371 **/ 372 373 static void 374 ip6_tnl_dev_uninit(struct net_device *dev) 375 { 376 struct ip6_tnl *t = netdev_priv(dev); 377 struct net *net = dev_net(dev); 378 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 379 380 if (dev == ip6n->fb_tnl_dev) 381 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 382 else 383 ip6_tnl_unlink(ip6n, t); 384 ip6_tnl_dst_reset(t); 385 dev_put(dev); 386 } 387 388 /** 389 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 390 * @skb: received socket buffer 391 * 392 * Return: 393 * 0 if none was found, 394 * else index to encapsulation limit 395 **/ 396 397 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw) 398 { 399 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw; 400 __u8 nexthdr = ipv6h->nexthdr; 401 __u16 off = sizeof (*ipv6h); 402 403 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 404 __u16 optlen = 0; 405 struct ipv6_opt_hdr *hdr; 406 if (raw + off + sizeof (*hdr) > skb->data && 407 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 408 break; 409 410 hdr = (struct ipv6_opt_hdr *) (raw + off); 411 if (nexthdr == NEXTHDR_FRAGMENT) { 412 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 413 if (frag_hdr->frag_off) 414 break; 415 optlen = 8; 416 } else if (nexthdr == NEXTHDR_AUTH) { 417 optlen = (hdr->hdrlen + 2) << 2; 418 } else { 419 optlen = ipv6_optlen(hdr); 420 } 421 if (nexthdr == NEXTHDR_DEST) { 422 __u16 i = off + 2; 423 while (1) { 424 struct ipv6_tlv_tnl_enc_lim *tel; 425 426 /* No more room for encapsulation limit */ 427 if (i + sizeof (*tel) > off + optlen) 428 break; 429 430 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 431 /* return index of option if found and valid */ 432 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 433 tel->length == 1) 434 return i; 435 /* else jump to next option */ 436 if (tel->type) 437 i += tel->length + 2; 438 else 439 i++; 440 } 441 } 442 nexthdr = hdr->nexthdr; 443 off += optlen; 444 } 445 return 0; 446 } 447 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim); 448 449 /** 450 * ip6_tnl_err - tunnel error handler 451 * 452 * Description: 453 * ip6_tnl_err() should handle errors in the tunnel according 454 * to the specifications in RFC 2473. 455 **/ 456 457 static int 458 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, 459 u8 *type, u8 *code, int *msg, __u32 *info, int offset) 460 { 461 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data; 462 struct ip6_tnl *t; 463 int rel_msg = 0; 464 u8 rel_type = ICMPV6_DEST_UNREACH; 465 u8 rel_code = ICMPV6_ADDR_UNREACH; 466 __u32 rel_info = 0; 467 __u16 len; 468 int err = -ENOENT; 469 470 /* If the packet doesn't contain the original IPv6 header we are 471 in trouble since we might need the source address for further 472 processing of the error. */ 473 474 rcu_read_lock(); 475 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, 476 &ipv6h->saddr)) == NULL) 477 goto out; 478 479 if (t->parms.proto != ipproto && t->parms.proto != 0) 480 goto out; 481 482 err = 0; 483 484 switch (*type) { 485 __u32 teli; 486 struct ipv6_tlv_tnl_enc_lim *tel; 487 __u32 mtu; 488 case ICMPV6_DEST_UNREACH: 489 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n", 490 t->parms.name); 491 rel_msg = 1; 492 break; 493 case ICMPV6_TIME_EXCEED: 494 if ((*code) == ICMPV6_EXC_HOPLIMIT) { 495 net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n", 496 t->parms.name); 497 rel_msg = 1; 498 } 499 break; 500 case ICMPV6_PARAMPROB: 501 teli = 0; 502 if ((*code) == ICMPV6_HDR_FIELD) 503 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data); 504 505 if (teli && teli == *info - 2) { 506 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 507 if (tel->encap_limit == 0) { 508 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n", 509 t->parms.name); 510 rel_msg = 1; 511 } 512 } else { 513 net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n", 514 t->parms.name); 515 } 516 break; 517 case ICMPV6_PKT_TOOBIG: 518 mtu = *info - offset; 519 if (mtu < IPV6_MIN_MTU) 520 mtu = IPV6_MIN_MTU; 521 t->dev->mtu = mtu; 522 523 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 524 rel_type = ICMPV6_PKT_TOOBIG; 525 rel_code = 0; 526 rel_info = mtu; 527 rel_msg = 1; 528 } 529 break; 530 } 531 532 *type = rel_type; 533 *code = rel_code; 534 *info = rel_info; 535 *msg = rel_msg; 536 537 out: 538 rcu_read_unlock(); 539 return err; 540 } 541 542 static int 543 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 544 u8 type, u8 code, int offset, __be32 info) 545 { 546 int rel_msg = 0; 547 u8 rel_type = type; 548 u8 rel_code = code; 549 __u32 rel_info = ntohl(info); 550 int err; 551 struct sk_buff *skb2; 552 const struct iphdr *eiph; 553 struct rtable *rt; 554 struct flowi4 fl4; 555 556 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, 557 &rel_msg, &rel_info, offset); 558 if (err < 0) 559 return err; 560 561 if (rel_msg == 0) 562 return 0; 563 564 switch (rel_type) { 565 case ICMPV6_DEST_UNREACH: 566 if (rel_code != ICMPV6_ADDR_UNREACH) 567 return 0; 568 rel_type = ICMP_DEST_UNREACH; 569 rel_code = ICMP_HOST_UNREACH; 570 break; 571 case ICMPV6_PKT_TOOBIG: 572 if (rel_code != 0) 573 return 0; 574 rel_type = ICMP_DEST_UNREACH; 575 rel_code = ICMP_FRAG_NEEDED; 576 break; 577 case NDISC_REDIRECT: 578 rel_type = ICMP_REDIRECT; 579 rel_code = ICMP_REDIR_HOST; 580 default: 581 return 0; 582 } 583 584 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) 585 return 0; 586 587 skb2 = skb_clone(skb, GFP_ATOMIC); 588 if (!skb2) 589 return 0; 590 591 skb_dst_drop(skb2); 592 593 skb_pull(skb2, offset); 594 skb_reset_network_header(skb2); 595 eiph = ip_hdr(skb2); 596 597 /* Try to guess incoming interface */ 598 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 599 eiph->saddr, 0, 600 0, 0, 601 IPPROTO_IPIP, RT_TOS(eiph->tos), 0); 602 if (IS_ERR(rt)) 603 goto out; 604 605 skb2->dev = rt->dst.dev; 606 607 /* route "incoming" packet */ 608 if (rt->rt_flags & RTCF_LOCAL) { 609 ip_rt_put(rt); 610 rt = NULL; 611 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 612 eiph->daddr, eiph->saddr, 613 0, 0, 614 IPPROTO_IPIP, 615 RT_TOS(eiph->tos), 0); 616 if (IS_ERR(rt) || 617 rt->dst.dev->type != ARPHRD_TUNNEL) { 618 if (!IS_ERR(rt)) 619 ip_rt_put(rt); 620 goto out; 621 } 622 skb_dst_set(skb2, &rt->dst); 623 } else { 624 ip_rt_put(rt); 625 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, 626 skb2->dev) || 627 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) 628 goto out; 629 } 630 631 /* change mtu on this route */ 632 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { 633 if (rel_info > dst_mtu(skb_dst(skb2))) 634 goto out; 635 636 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info); 637 } 638 if (rel_type == ICMP_REDIRECT) 639 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2); 640 641 icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); 642 643 out: 644 kfree_skb(skb2); 645 return 0; 646 } 647 648 static int 649 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 650 u8 type, u8 code, int offset, __be32 info) 651 { 652 int rel_msg = 0; 653 u8 rel_type = type; 654 u8 rel_code = code; 655 __u32 rel_info = ntohl(info); 656 int err; 657 658 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, 659 &rel_msg, &rel_info, offset); 660 if (err < 0) 661 return err; 662 663 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { 664 struct rt6_info *rt; 665 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 666 667 if (!skb2) 668 return 0; 669 670 skb_dst_drop(skb2); 671 skb_pull(skb2, offset); 672 skb_reset_network_header(skb2); 673 674 /* Try to guess incoming interface */ 675 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, 676 NULL, 0, 0); 677 678 if (rt && rt->dst.dev) 679 skb2->dev = rt->dst.dev; 680 681 icmpv6_send(skb2, rel_type, rel_code, rel_info); 682 683 ip6_rt_put(rt); 684 685 kfree_skb(skb2); 686 } 687 688 return 0; 689 } 690 691 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 692 const struct ipv6hdr *ipv6h, 693 struct sk_buff *skb) 694 { 695 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; 696 697 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 698 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); 699 700 return IP6_ECN_decapsulate(ipv6h, skb); 701 } 702 703 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 704 const struct ipv6hdr *ipv6h, 705 struct sk_buff *skb) 706 { 707 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 708 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); 709 710 return IP6_ECN_decapsulate(ipv6h, skb); 711 } 712 713 __u32 ip6_tnl_get_cap(struct ip6_tnl *t, 714 const struct in6_addr *laddr, 715 const struct in6_addr *raddr) 716 { 717 struct __ip6_tnl_parm *p = &t->parms; 718 int ltype = ipv6_addr_type(laddr); 719 int rtype = ipv6_addr_type(raddr); 720 __u32 flags = 0; 721 722 if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) { 723 flags = IP6_TNL_F_CAP_PER_PACKET; 724 } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 725 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 726 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 727 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 728 if (ltype&IPV6_ADDR_UNICAST) 729 flags |= IP6_TNL_F_CAP_XMIT; 730 if (rtype&IPV6_ADDR_UNICAST) 731 flags |= IP6_TNL_F_CAP_RCV; 732 } 733 return flags; 734 } 735 EXPORT_SYMBOL(ip6_tnl_get_cap); 736 737 /* called with rcu_read_lock() */ 738 int ip6_tnl_rcv_ctl(struct ip6_tnl *t, 739 const struct in6_addr *laddr, 740 const struct in6_addr *raddr) 741 { 742 struct __ip6_tnl_parm *p = &t->parms; 743 int ret = 0; 744 struct net *net = dev_net(t->dev); 745 746 if ((p->flags & IP6_TNL_F_CAP_RCV) || 747 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) && 748 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) { 749 struct net_device *ldev = NULL; 750 751 if (p->link) 752 ldev = dev_get_by_index_rcu(net, p->link); 753 754 if ((ipv6_addr_is_multicast(laddr) || 755 likely(ipv6_chk_addr(net, laddr, ldev, 0))) && 756 likely(!ipv6_chk_addr(net, raddr, NULL, 0))) 757 ret = 1; 758 } 759 return ret; 760 } 761 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl); 762 763 /** 764 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally 765 * @skb: received socket buffer 766 * @protocol: ethernet protocol ID 767 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN 768 * 769 * Return: 0 770 **/ 771 772 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, 773 __u8 ipproto, 774 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t, 775 const struct ipv6hdr *ipv6h, 776 struct sk_buff *skb)) 777 { 778 struct ip6_tnl *t; 779 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 780 int err; 781 782 rcu_read_lock(); 783 784 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, 785 &ipv6h->daddr)) != NULL) { 786 struct pcpu_tstats *tstats; 787 788 if (t->parms.proto != ipproto && t->parms.proto != 0) { 789 rcu_read_unlock(); 790 goto discard; 791 } 792 793 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 794 rcu_read_unlock(); 795 goto discard; 796 } 797 798 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 799 t->dev->stats.rx_dropped++; 800 rcu_read_unlock(); 801 goto discard; 802 } 803 secpath_reset(skb); 804 skb->mac_header = skb->network_header; 805 skb_reset_network_header(skb); 806 skb->protocol = htons(protocol); 807 skb->pkt_type = PACKET_HOST; 808 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 809 810 __skb_tunnel_rx(skb, t->dev); 811 812 err = dscp_ecn_decapsulate(t, ipv6h, skb); 813 if (unlikely(err)) { 814 if (log_ecn_error) 815 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n", 816 &ipv6h->saddr, 817 ipv6_get_dsfield(ipv6h)); 818 if (err > 1) { 819 ++t->dev->stats.rx_frame_errors; 820 ++t->dev->stats.rx_errors; 821 rcu_read_unlock(); 822 goto discard; 823 } 824 } 825 826 tstats = this_cpu_ptr(t->dev->tstats); 827 tstats->rx_packets++; 828 tstats->rx_bytes += skb->len; 829 830 netif_rx(skb); 831 832 rcu_read_unlock(); 833 return 0; 834 } 835 rcu_read_unlock(); 836 return 1; 837 838 discard: 839 kfree_skb(skb); 840 return 0; 841 } 842 843 static int ip4ip6_rcv(struct sk_buff *skb) 844 { 845 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, 846 ip4ip6_dscp_ecn_decapsulate); 847 } 848 849 static int ip6ip6_rcv(struct sk_buff *skb) 850 { 851 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, 852 ip6ip6_dscp_ecn_decapsulate); 853 } 854 855 struct ipv6_tel_txoption { 856 struct ipv6_txoptions ops; 857 __u8 dst_opt[8]; 858 }; 859 860 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 861 { 862 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 863 864 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 865 opt->dst_opt[3] = 1; 866 opt->dst_opt[4] = encap_limit; 867 opt->dst_opt[5] = IPV6_TLV_PADN; 868 opt->dst_opt[6] = 1; 869 870 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 871 opt->ops.opt_nflen = 8; 872 } 873 874 /** 875 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 876 * @t: the outgoing tunnel device 877 * @hdr: IPv6 header from the incoming packet 878 * 879 * Description: 880 * Avoid trivial tunneling loop by checking that tunnel exit-point 881 * doesn't match source of incoming packet. 882 * 883 * Return: 884 * 1 if conflict, 885 * 0 else 886 **/ 887 888 static inline bool 889 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 890 { 891 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 892 } 893 894 int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 895 { 896 struct __ip6_tnl_parm *p = &t->parms; 897 int ret = 0; 898 struct net *net = dev_net(t->dev); 899 900 if (p->flags & IP6_TNL_F_CAP_XMIT) { 901 struct net_device *ldev = NULL; 902 903 rcu_read_lock(); 904 if (p->link) 905 ldev = dev_get_by_index_rcu(net, p->link); 906 907 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) 908 pr_warn("%s xmit: Local address not yet configured!\n", 909 p->name); 910 else if (!ipv6_addr_is_multicast(&p->raddr) && 911 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) 912 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n", 913 p->name); 914 else 915 ret = 1; 916 rcu_read_unlock(); 917 } 918 return ret; 919 } 920 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl); 921 922 /** 923 * ip6_tnl_xmit2 - encapsulate packet and send 924 * @skb: the outgoing socket buffer 925 * @dev: the outgoing tunnel device 926 * @dsfield: dscp code for outer header 927 * @fl: flow of tunneled packet 928 * @encap_limit: encapsulation limit 929 * @pmtu: Path MTU is stored if packet is too big 930 * 931 * Description: 932 * Build new header and do some sanity checks on the packet before sending 933 * it. 934 * 935 * Return: 936 * 0 on success 937 * -1 fail 938 * %-EMSGSIZE message too big. return mtu in this case. 939 **/ 940 941 static int ip6_tnl_xmit2(struct sk_buff *skb, 942 struct net_device *dev, 943 __u8 dsfield, 944 struct flowi6 *fl6, 945 int encap_limit, 946 __u32 *pmtu) 947 { 948 struct net *net = dev_net(dev); 949 struct ip6_tnl *t = netdev_priv(dev); 950 struct net_device_stats *stats = &t->dev->stats; 951 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 952 struct ipv6_tel_txoption opt; 953 struct dst_entry *dst = NULL, *ndst = NULL; 954 struct net_device *tdev; 955 int mtu; 956 unsigned int max_headroom = sizeof(struct ipv6hdr); 957 u8 proto; 958 int err = -1; 959 960 if (!fl6->flowi6_mark) 961 dst = ip6_tnl_dst_check(t); 962 if (!dst) { 963 ndst = ip6_route_output(net, NULL, fl6); 964 965 if (ndst->error) 966 goto tx_err_link_failure; 967 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0); 968 if (IS_ERR(ndst)) { 969 err = PTR_ERR(ndst); 970 ndst = NULL; 971 goto tx_err_link_failure; 972 } 973 dst = ndst; 974 } 975 976 tdev = dst->dev; 977 978 if (tdev == dev) { 979 stats->collisions++; 980 net_warn_ratelimited("%s: Local routing loop detected!\n", 981 t->parms.name); 982 goto tx_err_dst_release; 983 } 984 mtu = dst_mtu(dst) - sizeof (*ipv6h); 985 if (encap_limit >= 0) { 986 max_headroom += 8; 987 mtu -= 8; 988 } 989 if (mtu < IPV6_MIN_MTU) 990 mtu = IPV6_MIN_MTU; 991 if (skb_dst(skb)) 992 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 993 if (skb->len > mtu) { 994 *pmtu = mtu; 995 err = -EMSGSIZE; 996 goto tx_err_dst_release; 997 } 998 999 /* 1000 * Okay, now see if we can stuff it in the buffer as-is. 1001 */ 1002 max_headroom += LL_RESERVED_SPACE(tdev); 1003 1004 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 1005 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 1006 struct sk_buff *new_skb; 1007 1008 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 1009 goto tx_err_dst_release; 1010 1011 if (skb->sk) 1012 skb_set_owner_w(new_skb, skb->sk); 1013 consume_skb(skb); 1014 skb = new_skb; 1015 } 1016 skb_dst_drop(skb); 1017 if (fl6->flowi6_mark) { 1018 skb_dst_set(skb, dst); 1019 ndst = NULL; 1020 } else { 1021 skb_dst_set_noref(skb, dst); 1022 } 1023 skb->transport_header = skb->network_header; 1024 1025 proto = fl6->flowi6_proto; 1026 if (encap_limit >= 0) { 1027 init_tel_txopt(&opt, encap_limit); 1028 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 1029 } 1030 skb_push(skb, sizeof(struct ipv6hdr)); 1031 skb_reset_network_header(skb); 1032 ipv6h = ipv6_hdr(skb); 1033 ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), fl6->flowlabel); 1034 ipv6h->hop_limit = t->parms.hop_limit; 1035 ipv6h->nexthdr = proto; 1036 ipv6h->saddr = fl6->saddr; 1037 ipv6h->daddr = fl6->daddr; 1038 ip6tunnel_xmit(skb, dev); 1039 if (ndst) 1040 ip6_tnl_dst_store(t, ndst); 1041 return 0; 1042 tx_err_link_failure: 1043 stats->tx_carrier_errors++; 1044 dst_link_failure(skb); 1045 tx_err_dst_release: 1046 dst_release(ndst); 1047 return err; 1048 } 1049 1050 static inline int 1051 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1052 { 1053 struct ip6_tnl *t = netdev_priv(dev); 1054 const struct iphdr *iph = ip_hdr(skb); 1055 int encap_limit = -1; 1056 struct flowi6 fl6; 1057 __u8 dsfield; 1058 __u32 mtu; 1059 int err; 1060 1061 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || 1062 !ip6_tnl_xmit_ctl(t)) 1063 return -1; 1064 1065 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1066 encap_limit = t->parms.encap_limit; 1067 1068 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6)); 1069 fl6.flowi6_proto = IPPROTO_IPIP; 1070 1071 dsfield = ipv4_get_dsfield(iph); 1072 1073 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1074 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) 1075 & IPV6_TCLASS_MASK; 1076 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1077 fl6.flowi6_mark = skb->mark; 1078 1079 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1080 if (err != 0) { 1081 /* XXX: send ICMP error even if DF is not set. */ 1082 if (err == -EMSGSIZE) 1083 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 1084 htonl(mtu)); 1085 return -1; 1086 } 1087 1088 return 0; 1089 } 1090 1091 static inline int 1092 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1093 { 1094 struct ip6_tnl *t = netdev_priv(dev); 1095 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1096 int encap_limit = -1; 1097 __u16 offset; 1098 struct flowi6 fl6; 1099 __u8 dsfield; 1100 __u32 mtu; 1101 int err; 1102 1103 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 1104 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) 1105 return -1; 1106 1107 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb)); 1108 if (offset > 0) { 1109 struct ipv6_tlv_tnl_enc_lim *tel; 1110 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; 1111 if (tel->encap_limit == 0) { 1112 icmpv6_send(skb, ICMPV6_PARAMPROB, 1113 ICMPV6_HDR_FIELD, offset + 2); 1114 return -1; 1115 } 1116 encap_limit = tel->encap_limit - 1; 1117 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1118 encap_limit = t->parms.encap_limit; 1119 1120 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6)); 1121 fl6.flowi6_proto = IPPROTO_IPV6; 1122 1123 dsfield = ipv6_get_dsfield(ipv6h); 1124 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1125 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 1126 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL) 1127 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); 1128 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1129 fl6.flowi6_mark = skb->mark; 1130 1131 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1132 if (err != 0) { 1133 if (err == -EMSGSIZE) 1134 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1135 return -1; 1136 } 1137 1138 return 0; 1139 } 1140 1141 static netdev_tx_t 1142 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1143 { 1144 struct ip6_tnl *t = netdev_priv(dev); 1145 struct net_device_stats *stats = &t->dev->stats; 1146 int ret; 1147 1148 switch (skb->protocol) { 1149 case htons(ETH_P_IP): 1150 ret = ip4ip6_tnl_xmit(skb, dev); 1151 break; 1152 case htons(ETH_P_IPV6): 1153 ret = ip6ip6_tnl_xmit(skb, dev); 1154 break; 1155 default: 1156 goto tx_err; 1157 } 1158 1159 if (ret < 0) 1160 goto tx_err; 1161 1162 return NETDEV_TX_OK; 1163 1164 tx_err: 1165 stats->tx_errors++; 1166 stats->tx_dropped++; 1167 kfree_skb(skb); 1168 return NETDEV_TX_OK; 1169 } 1170 1171 static void ip6_tnl_link_config(struct ip6_tnl *t) 1172 { 1173 struct net_device *dev = t->dev; 1174 struct __ip6_tnl_parm *p = &t->parms; 1175 struct flowi6 *fl6 = &t->fl.u.ip6; 1176 1177 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 1178 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 1179 1180 /* Set up flowi template */ 1181 fl6->saddr = p->laddr; 1182 fl6->daddr = p->raddr; 1183 fl6->flowi6_oif = p->link; 1184 fl6->flowlabel = 0; 1185 1186 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 1187 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 1188 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1189 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 1190 1191 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET); 1192 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 1193 1194 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 1195 dev->flags |= IFF_POINTOPOINT; 1196 else 1197 dev->flags &= ~IFF_POINTOPOINT; 1198 1199 dev->iflink = p->link; 1200 1201 if (p->flags & IP6_TNL_F_CAP_XMIT) { 1202 int strict = (ipv6_addr_type(&p->raddr) & 1203 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 1204 1205 struct rt6_info *rt = rt6_lookup(dev_net(dev), 1206 &p->raddr, &p->laddr, 1207 p->link, strict); 1208 1209 if (rt == NULL) 1210 return; 1211 1212 if (rt->dst.dev) { 1213 dev->hard_header_len = rt->dst.dev->hard_header_len + 1214 sizeof (struct ipv6hdr); 1215 1216 dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr); 1217 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1218 dev->mtu-=8; 1219 1220 if (dev->mtu < IPV6_MIN_MTU) 1221 dev->mtu = IPV6_MIN_MTU; 1222 } 1223 ip6_rt_put(rt); 1224 } 1225 } 1226 1227 /** 1228 * ip6_tnl_change - update the tunnel parameters 1229 * @t: tunnel to be changed 1230 * @p: tunnel configuration parameters 1231 * 1232 * Description: 1233 * ip6_tnl_change() updates the tunnel parameters 1234 **/ 1235 1236 static int 1237 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p) 1238 { 1239 t->parms.laddr = p->laddr; 1240 t->parms.raddr = p->raddr; 1241 t->parms.flags = p->flags; 1242 t->parms.hop_limit = p->hop_limit; 1243 t->parms.encap_limit = p->encap_limit; 1244 t->parms.flowinfo = p->flowinfo; 1245 t->parms.link = p->link; 1246 t->parms.proto = p->proto; 1247 ip6_tnl_dst_reset(t); 1248 ip6_tnl_link_config(t); 1249 return 0; 1250 } 1251 1252 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p) 1253 { 1254 struct net *net = dev_net(t->dev); 1255 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1256 int err; 1257 1258 ip6_tnl_unlink(ip6n, t); 1259 synchronize_net(); 1260 err = ip6_tnl_change(t, p); 1261 ip6_tnl_link(ip6n, t); 1262 netdev_state_change(t->dev); 1263 return err; 1264 } 1265 1266 static void 1267 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u) 1268 { 1269 p->laddr = u->laddr; 1270 p->raddr = u->raddr; 1271 p->flags = u->flags; 1272 p->hop_limit = u->hop_limit; 1273 p->encap_limit = u->encap_limit; 1274 p->flowinfo = u->flowinfo; 1275 p->link = u->link; 1276 p->proto = u->proto; 1277 memcpy(p->name, u->name, sizeof(u->name)); 1278 } 1279 1280 static void 1281 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p) 1282 { 1283 u->laddr = p->laddr; 1284 u->raddr = p->raddr; 1285 u->flags = p->flags; 1286 u->hop_limit = p->hop_limit; 1287 u->encap_limit = p->encap_limit; 1288 u->flowinfo = p->flowinfo; 1289 u->link = p->link; 1290 u->proto = p->proto; 1291 memcpy(u->name, p->name, sizeof(u->name)); 1292 } 1293 1294 /** 1295 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace 1296 * @dev: virtual device associated with tunnel 1297 * @ifr: parameters passed from userspace 1298 * @cmd: command to be performed 1299 * 1300 * Description: 1301 * ip6_tnl_ioctl() is used for managing IPv6 tunnels 1302 * from userspace. 1303 * 1304 * The possible commands are the following: 1305 * %SIOCGETTUNNEL: get tunnel parameters for device 1306 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 1307 * %SIOCCHGTUNNEL: change tunnel parameters to those given 1308 * %SIOCDELTUNNEL: delete tunnel 1309 * 1310 * The fallback device "ip6tnl0", created during module 1311 * initialization, can be used for creating other tunnel devices. 1312 * 1313 * Return: 1314 * 0 on success, 1315 * %-EFAULT if unable to copy data to or from userspace, 1316 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 1317 * %-EINVAL if passed tunnel parameters are invalid, 1318 * %-EEXIST if changing a tunnel's parameters would cause a conflict 1319 * %-ENODEV if attempting to change or delete a nonexisting device 1320 **/ 1321 1322 static int 1323 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1324 { 1325 int err = 0; 1326 struct ip6_tnl_parm p; 1327 struct __ip6_tnl_parm p1; 1328 struct ip6_tnl *t = NULL; 1329 struct net *net = dev_net(dev); 1330 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1331 1332 switch (cmd) { 1333 case SIOCGETTUNNEL: 1334 if (dev == ip6n->fb_tnl_dev) { 1335 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 1336 err = -EFAULT; 1337 break; 1338 } 1339 ip6_tnl_parm_from_user(&p1, &p); 1340 t = ip6_tnl_locate(net, &p1, 0); 1341 } else { 1342 memset(&p, 0, sizeof(p)); 1343 } 1344 if (t == NULL) 1345 t = netdev_priv(dev); 1346 ip6_tnl_parm_to_user(&p, &t->parms); 1347 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 1348 err = -EFAULT; 1349 } 1350 break; 1351 case SIOCADDTUNNEL: 1352 case SIOCCHGTUNNEL: 1353 err = -EPERM; 1354 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1355 break; 1356 err = -EFAULT; 1357 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1358 break; 1359 err = -EINVAL; 1360 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && 1361 p.proto != 0) 1362 break; 1363 ip6_tnl_parm_from_user(&p1, &p); 1364 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL); 1365 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 1366 if (t != NULL) { 1367 if (t->dev != dev) { 1368 err = -EEXIST; 1369 break; 1370 } 1371 } else 1372 t = netdev_priv(dev); 1373 1374 err = ip6_tnl_update(t, &p1); 1375 } 1376 if (t) { 1377 err = 0; 1378 ip6_tnl_parm_to_user(&p, &t->parms); 1379 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 1380 err = -EFAULT; 1381 1382 } else 1383 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1384 break; 1385 case SIOCDELTUNNEL: 1386 err = -EPERM; 1387 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1388 break; 1389 1390 if (dev == ip6n->fb_tnl_dev) { 1391 err = -EFAULT; 1392 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1393 break; 1394 err = -ENOENT; 1395 ip6_tnl_parm_from_user(&p1, &p); 1396 t = ip6_tnl_locate(net, &p1, 0); 1397 if (t == NULL) 1398 break; 1399 err = -EPERM; 1400 if (t->dev == ip6n->fb_tnl_dev) 1401 break; 1402 dev = t->dev; 1403 } 1404 err = 0; 1405 unregister_netdevice(dev); 1406 break; 1407 default: 1408 err = -EINVAL; 1409 } 1410 return err; 1411 } 1412 1413 /** 1414 * ip6_tnl_change_mtu - change mtu manually for tunnel device 1415 * @dev: virtual device associated with tunnel 1416 * @new_mtu: the new mtu 1417 * 1418 * Return: 1419 * 0 on success, 1420 * %-EINVAL if mtu too small 1421 **/ 1422 1423 static int 1424 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1425 { 1426 if (new_mtu < IPV6_MIN_MTU) { 1427 return -EINVAL; 1428 } 1429 dev->mtu = new_mtu; 1430 return 0; 1431 } 1432 1433 1434 static const struct net_device_ops ip6_tnl_netdev_ops = { 1435 .ndo_uninit = ip6_tnl_dev_uninit, 1436 .ndo_start_xmit = ip6_tnl_xmit, 1437 .ndo_do_ioctl = ip6_tnl_ioctl, 1438 .ndo_change_mtu = ip6_tnl_change_mtu, 1439 .ndo_get_stats = ip6_get_stats, 1440 }; 1441 1442 1443 /** 1444 * ip6_tnl_dev_setup - setup virtual tunnel device 1445 * @dev: virtual device associated with tunnel 1446 * 1447 * Description: 1448 * Initialize function pointers and device parameters 1449 **/ 1450 1451 static void ip6_tnl_dev_setup(struct net_device *dev) 1452 { 1453 struct ip6_tnl *t; 1454 1455 dev->netdev_ops = &ip6_tnl_netdev_ops; 1456 dev->destructor = ip6_dev_free; 1457 1458 dev->type = ARPHRD_TUNNEL6; 1459 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1460 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1461 t = netdev_priv(dev); 1462 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1463 dev->mtu-=8; 1464 dev->flags |= IFF_NOARP; 1465 dev->addr_len = sizeof(struct in6_addr); 1466 dev->features |= NETIF_F_NETNS_LOCAL; 1467 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1468 } 1469 1470 1471 /** 1472 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1473 * @dev: virtual device associated with tunnel 1474 **/ 1475 1476 static inline int 1477 ip6_tnl_dev_init_gen(struct net_device *dev) 1478 { 1479 struct ip6_tnl *t = netdev_priv(dev); 1480 1481 t->dev = dev; 1482 dev->tstats = alloc_percpu(struct pcpu_tstats); 1483 if (!dev->tstats) 1484 return -ENOMEM; 1485 return 0; 1486 } 1487 1488 /** 1489 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1490 * @dev: virtual device associated with tunnel 1491 **/ 1492 1493 static int ip6_tnl_dev_init(struct net_device *dev) 1494 { 1495 struct ip6_tnl *t = netdev_priv(dev); 1496 int err = ip6_tnl_dev_init_gen(dev); 1497 1498 if (err) 1499 return err; 1500 ip6_tnl_link_config(t); 1501 return 0; 1502 } 1503 1504 /** 1505 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1506 * @dev: fallback device 1507 * 1508 * Return: 0 1509 **/ 1510 1511 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev) 1512 { 1513 struct ip6_tnl *t = netdev_priv(dev); 1514 struct net *net = dev_net(dev); 1515 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1516 int err = ip6_tnl_dev_init_gen(dev); 1517 1518 if (err) 1519 return err; 1520 1521 t->parms.proto = IPPROTO_IPV6; 1522 dev_hold(dev); 1523 1524 ip6_tnl_link_config(t); 1525 1526 rcu_assign_pointer(ip6n->tnls_wc[0], t); 1527 return 0; 1528 } 1529 1530 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[]) 1531 { 1532 u8 proto; 1533 1534 if (!data) 1535 return 0; 1536 1537 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1538 if (proto != IPPROTO_IPV6 && 1539 proto != IPPROTO_IPIP && 1540 proto != 0) 1541 return -EINVAL; 1542 1543 return 0; 1544 } 1545 1546 static void ip6_tnl_netlink_parms(struct nlattr *data[], 1547 struct __ip6_tnl_parm *parms) 1548 { 1549 memset(parms, 0, sizeof(*parms)); 1550 1551 if (!data) 1552 return; 1553 1554 if (data[IFLA_IPTUN_LINK]) 1555 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1556 1557 if (data[IFLA_IPTUN_LOCAL]) 1558 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL], 1559 sizeof(struct in6_addr)); 1560 1561 if (data[IFLA_IPTUN_REMOTE]) 1562 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE], 1563 sizeof(struct in6_addr)); 1564 1565 if (data[IFLA_IPTUN_TTL]) 1566 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]); 1567 1568 if (data[IFLA_IPTUN_ENCAP_LIMIT]) 1569 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]); 1570 1571 if (data[IFLA_IPTUN_FLOWINFO]) 1572 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]); 1573 1574 if (data[IFLA_IPTUN_FLAGS]) 1575 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]); 1576 1577 if (data[IFLA_IPTUN_PROTO]) 1578 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1579 } 1580 1581 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev, 1582 struct nlattr *tb[], struct nlattr *data[]) 1583 { 1584 struct net *net = dev_net(dev); 1585 struct ip6_tnl *nt; 1586 1587 nt = netdev_priv(dev); 1588 ip6_tnl_netlink_parms(data, &nt->parms); 1589 1590 if (ip6_tnl_locate(net, &nt->parms, 0)) 1591 return -EEXIST; 1592 1593 return ip6_tnl_create2(dev); 1594 } 1595 1596 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[], 1597 struct nlattr *data[]) 1598 { 1599 struct ip6_tnl *t; 1600 struct __ip6_tnl_parm p; 1601 struct net *net = dev_net(dev); 1602 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1603 1604 if (dev == ip6n->fb_tnl_dev) 1605 return -EINVAL; 1606 1607 ip6_tnl_netlink_parms(data, &p); 1608 1609 t = ip6_tnl_locate(net, &p, 0); 1610 1611 if (t) { 1612 if (t->dev != dev) 1613 return -EEXIST; 1614 } else 1615 t = netdev_priv(dev); 1616 1617 return ip6_tnl_update(t, &p); 1618 } 1619 1620 static size_t ip6_tnl_get_size(const struct net_device *dev) 1621 { 1622 return 1623 /* IFLA_IPTUN_LINK */ 1624 nla_total_size(4) + 1625 /* IFLA_IPTUN_LOCAL */ 1626 nla_total_size(sizeof(struct in6_addr)) + 1627 /* IFLA_IPTUN_REMOTE */ 1628 nla_total_size(sizeof(struct in6_addr)) + 1629 /* IFLA_IPTUN_TTL */ 1630 nla_total_size(1) + 1631 /* IFLA_IPTUN_ENCAP_LIMIT */ 1632 nla_total_size(1) + 1633 /* IFLA_IPTUN_FLOWINFO */ 1634 nla_total_size(4) + 1635 /* IFLA_IPTUN_FLAGS */ 1636 nla_total_size(4) + 1637 /* IFLA_IPTUN_PROTO */ 1638 nla_total_size(1) + 1639 0; 1640 } 1641 1642 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1643 { 1644 struct ip6_tnl *tunnel = netdev_priv(dev); 1645 struct __ip6_tnl_parm *parm = &tunnel->parms; 1646 1647 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1648 nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr), 1649 &parm->raddr) || 1650 nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr), 1651 &parm->laddr) || 1652 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) || 1653 nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) || 1654 nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) || 1655 nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) || 1656 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto)) 1657 goto nla_put_failure; 1658 return 0; 1659 1660 nla_put_failure: 1661 return -EMSGSIZE; 1662 } 1663 1664 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = { 1665 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1666 [IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) }, 1667 [IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) }, 1668 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1669 [IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 }, 1670 [IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 }, 1671 [IFLA_IPTUN_FLAGS] = { .type = NLA_U32 }, 1672 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1673 }; 1674 1675 static struct rtnl_link_ops ip6_link_ops __read_mostly = { 1676 .kind = "ip6tnl", 1677 .maxtype = IFLA_IPTUN_MAX, 1678 .policy = ip6_tnl_policy, 1679 .priv_size = sizeof(struct ip6_tnl), 1680 .setup = ip6_tnl_dev_setup, 1681 .validate = ip6_tnl_validate, 1682 .newlink = ip6_tnl_newlink, 1683 .changelink = ip6_tnl_changelink, 1684 .get_size = ip6_tnl_get_size, 1685 .fill_info = ip6_tnl_fill_info, 1686 }; 1687 1688 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { 1689 .handler = ip4ip6_rcv, 1690 .err_handler = ip4ip6_err, 1691 .priority = 1, 1692 }; 1693 1694 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { 1695 .handler = ip6ip6_rcv, 1696 .err_handler = ip6ip6_err, 1697 .priority = 1, 1698 }; 1699 1700 static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) 1701 { 1702 int h; 1703 struct ip6_tnl *t; 1704 LIST_HEAD(list); 1705 1706 for (h = 0; h < HASH_SIZE; h++) { 1707 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1708 while (t != NULL) { 1709 unregister_netdevice_queue(t->dev, &list); 1710 t = rtnl_dereference(t->next); 1711 } 1712 } 1713 1714 t = rtnl_dereference(ip6n->tnls_wc[0]); 1715 unregister_netdevice_queue(t->dev, &list); 1716 unregister_netdevice_many(&list); 1717 } 1718 1719 static int __net_init ip6_tnl_init_net(struct net *net) 1720 { 1721 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1722 struct ip6_tnl *t = NULL; 1723 int err; 1724 1725 ip6n->tnls[0] = ip6n->tnls_wc; 1726 ip6n->tnls[1] = ip6n->tnls_r_l; 1727 1728 err = -ENOMEM; 1729 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1730 ip6_tnl_dev_setup); 1731 1732 if (!ip6n->fb_tnl_dev) 1733 goto err_alloc_dev; 1734 dev_net_set(ip6n->fb_tnl_dev, net); 1735 1736 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1737 if (err < 0) 1738 goto err_register; 1739 1740 err = register_netdev(ip6n->fb_tnl_dev); 1741 if (err < 0) 1742 goto err_register; 1743 1744 t = netdev_priv(ip6n->fb_tnl_dev); 1745 1746 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1747 return 0; 1748 1749 err_register: 1750 ip6_dev_free(ip6n->fb_tnl_dev); 1751 err_alloc_dev: 1752 return err; 1753 } 1754 1755 static void __net_exit ip6_tnl_exit_net(struct net *net) 1756 { 1757 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1758 1759 rtnl_lock(); 1760 ip6_tnl_destroy_tunnels(ip6n); 1761 rtnl_unlock(); 1762 } 1763 1764 static struct pernet_operations ip6_tnl_net_ops = { 1765 .init = ip6_tnl_init_net, 1766 .exit = ip6_tnl_exit_net, 1767 .id = &ip6_tnl_net_id, 1768 .size = sizeof(struct ip6_tnl_net), 1769 }; 1770 1771 /** 1772 * ip6_tunnel_init - register protocol and reserve needed resources 1773 * 1774 * Return: 0 on success 1775 **/ 1776 1777 static int __init ip6_tunnel_init(void) 1778 { 1779 int err; 1780 1781 err = register_pernet_device(&ip6_tnl_net_ops); 1782 if (err < 0) 1783 goto out_pernet; 1784 1785 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); 1786 if (err < 0) { 1787 pr_err("%s: can't register ip4ip6\n", __func__); 1788 goto out_ip4ip6; 1789 } 1790 1791 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); 1792 if (err < 0) { 1793 pr_err("%s: can't register ip6ip6\n", __func__); 1794 goto out_ip6ip6; 1795 } 1796 err = rtnl_link_register(&ip6_link_ops); 1797 if (err < 0) 1798 goto rtnl_link_failed; 1799 1800 return 0; 1801 1802 rtnl_link_failed: 1803 xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6); 1804 out_ip6ip6: 1805 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); 1806 out_ip4ip6: 1807 unregister_pernet_device(&ip6_tnl_net_ops); 1808 out_pernet: 1809 return err; 1810 } 1811 1812 /** 1813 * ip6_tunnel_cleanup - free resources and unregister protocol 1814 **/ 1815 1816 static void __exit ip6_tunnel_cleanup(void) 1817 { 1818 rtnl_link_unregister(&ip6_link_ops); 1819 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) 1820 pr_info("%s: can't deregister ip4ip6\n", __func__); 1821 1822 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1823 pr_info("%s: can't deregister ip6ip6\n", __func__); 1824 1825 unregister_pernet_device(&ip6_tnl_net_ops); 1826 } 1827 1828 module_init(ip6_tunnel_init); 1829 module_exit(ip6_tunnel_cleanup); 1830