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/net.h> 33 #include <linux/in6.h> 34 #include <linux/netdevice.h> 35 #include <linux/if_arp.h> 36 #include <linux/icmpv6.h> 37 #include <linux/init.h> 38 #include <linux/route.h> 39 #include <linux/rtnetlink.h> 40 #include <linux/netfilter_ipv6.h> 41 #include <linux/slab.h> 42 #include <linux/hash.h> 43 #include <linux/etherdevice.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_RTNL_LINK("ip6tnl"); 65 MODULE_ALIAS_NETDEV("ip6tnl0"); 66 67 #ifdef IP6_TNL_DEBUG 68 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__) 69 #else 70 #define IP6_TNL_TRACE(x...) do {;} while(0) 71 #endif 72 73 #define HASH_SIZE_SHIFT 5 74 #define HASH_SIZE (1 << HASH_SIZE_SHIFT) 75 76 static bool log_ecn_error = true; 77 module_param(log_ecn_error, bool, 0644); 78 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN"); 79 80 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 81 { 82 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 83 84 return hash_32(hash, HASH_SIZE_SHIFT); 85 } 86 87 static int ip6_tnl_dev_init(struct net_device *dev); 88 static void ip6_tnl_dev_setup(struct net_device *dev); 89 static struct rtnl_link_ops ip6_link_ops __read_mostly; 90 91 static int ip6_tnl_net_id __read_mostly; 92 struct ip6_tnl_net { 93 /* the IPv6 tunnel fallback device */ 94 struct net_device *fb_tnl_dev; 95 /* lists for storing tunnels in use */ 96 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE]; 97 struct ip6_tnl __rcu *tnls_wc[1]; 98 struct ip6_tnl __rcu **tnls[2]; 99 }; 100 101 static struct net_device_stats *ip6_get_stats(struct net_device *dev) 102 { 103 struct pcpu_sw_netstats tmp, sum = { 0 }; 104 int i; 105 106 for_each_possible_cpu(i) { 107 unsigned int start; 108 const struct pcpu_sw_netstats *tstats = 109 per_cpu_ptr(dev->tstats, i); 110 111 do { 112 start = u64_stats_fetch_begin_irq(&tstats->syncp); 113 tmp.rx_packets = tstats->rx_packets; 114 tmp.rx_bytes = tstats->rx_bytes; 115 tmp.tx_packets = tstats->tx_packets; 116 tmp.tx_bytes = tstats->tx_bytes; 117 } while (u64_stats_fetch_retry_irq(&tstats->syncp, start)); 118 119 sum.rx_packets += tmp.rx_packets; 120 sum.rx_bytes += tmp.rx_bytes; 121 sum.tx_packets += tmp.tx_packets; 122 sum.tx_bytes += tmp.tx_bytes; 123 } 124 dev->stats.rx_packets = sum.rx_packets; 125 dev->stats.rx_bytes = sum.rx_bytes; 126 dev->stats.tx_packets = sum.tx_packets; 127 dev->stats.tx_bytes = sum.tx_bytes; 128 return &dev->stats; 129 } 130 131 /* 132 * Locking : hash tables are protected by RCU and RTNL 133 */ 134 135 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 136 { 137 struct dst_entry *dst = t->dst_cache; 138 139 if (dst && dst->obsolete && 140 dst->ops->check(dst, t->dst_cookie) == NULL) { 141 t->dst_cache = NULL; 142 dst_release(dst); 143 return NULL; 144 } 145 146 return dst; 147 } 148 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check); 149 150 void ip6_tnl_dst_reset(struct ip6_tnl *t) 151 { 152 dst_release(t->dst_cache); 153 t->dst_cache = NULL; 154 } 155 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset); 156 157 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 158 { 159 struct rt6_info *rt = (struct rt6_info *) dst; 160 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 161 dst_release(t->dst_cache); 162 t->dst_cache = dst; 163 } 164 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store); 165 166 /** 167 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses 168 * @remote: the address of the tunnel exit-point 169 * @local: the address of the tunnel entry-point 170 * 171 * Return: 172 * tunnel matching given end-points if found, 173 * else fallback tunnel if its device is up, 174 * else %NULL 175 **/ 176 177 #define for_each_ip6_tunnel_rcu(start) \ 178 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 179 180 static struct ip6_tnl * 181 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local) 182 { 183 unsigned int hash = HASH(remote, local); 184 struct ip6_tnl *t; 185 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 186 187 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 188 if (ipv6_addr_equal(local, &t->parms.laddr) && 189 ipv6_addr_equal(remote, &t->parms.raddr) && 190 (t->dev->flags & IFF_UP)) 191 return t; 192 } 193 t = rcu_dereference(ip6n->tnls_wc[0]); 194 if (t && (t->dev->flags & IFF_UP)) 195 return t; 196 197 return NULL; 198 } 199 200 /** 201 * ip6_tnl_bucket - get head of list matching given tunnel parameters 202 * @p: parameters containing tunnel end-points 203 * 204 * Description: 205 * ip6_tnl_bucket() returns the head of the list matching the 206 * &struct in6_addr entries laddr and raddr in @p. 207 * 208 * Return: head of IPv6 tunnel list 209 **/ 210 211 static struct ip6_tnl __rcu ** 212 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p) 213 { 214 const struct in6_addr *remote = &p->raddr; 215 const struct in6_addr *local = &p->laddr; 216 unsigned int h = 0; 217 int prio = 0; 218 219 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 220 prio = 1; 221 h = HASH(remote, local); 222 } 223 return &ip6n->tnls[prio][h]; 224 } 225 226 /** 227 * ip6_tnl_link - add tunnel to hash table 228 * @t: tunnel to be added 229 **/ 230 231 static void 232 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 233 { 234 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); 235 236 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 237 rcu_assign_pointer(*tp, t); 238 } 239 240 /** 241 * ip6_tnl_unlink - remove tunnel from hash table 242 * @t: tunnel to be removed 243 **/ 244 245 static void 246 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 247 { 248 struct ip6_tnl __rcu **tp; 249 struct ip6_tnl *iter; 250 251 for (tp = ip6_tnl_bucket(ip6n, &t->parms); 252 (iter = rtnl_dereference(*tp)) != NULL; 253 tp = &iter->next) { 254 if (t == iter) { 255 rcu_assign_pointer(*tp, t->next); 256 break; 257 } 258 } 259 } 260 261 static void ip6_dev_free(struct net_device *dev) 262 { 263 free_percpu(dev->tstats); 264 free_netdev(dev); 265 } 266 267 static int ip6_tnl_create2(struct net_device *dev) 268 { 269 struct ip6_tnl *t = netdev_priv(dev); 270 struct net *net = dev_net(dev); 271 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 272 int err; 273 274 t = netdev_priv(dev); 275 err = ip6_tnl_dev_init(dev); 276 if (err < 0) 277 goto out; 278 279 err = register_netdevice(dev); 280 if (err < 0) 281 goto out; 282 283 strcpy(t->parms.name, dev->name); 284 dev->rtnl_link_ops = &ip6_link_ops; 285 286 dev_hold(dev); 287 ip6_tnl_link(ip6n, t); 288 return 0; 289 290 out: 291 return err; 292 } 293 294 /** 295 * ip6_tnl_create - create a new tunnel 296 * @p: tunnel parameters 297 * @pt: pointer to new tunnel 298 * 299 * Description: 300 * Create tunnel matching given parameters. 301 * 302 * Return: 303 * created tunnel or NULL 304 **/ 305 306 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 307 { 308 struct net_device *dev; 309 struct ip6_tnl *t; 310 char name[IFNAMSIZ]; 311 int err; 312 313 if (p->name[0]) 314 strlcpy(name, p->name, IFNAMSIZ); 315 else 316 sprintf(name, "ip6tnl%%d"); 317 318 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, 319 ip6_tnl_dev_setup); 320 if (dev == NULL) 321 goto failed; 322 323 dev_net_set(dev, net); 324 325 t = netdev_priv(dev); 326 t->parms = *p; 327 t->net = dev_net(dev); 328 err = ip6_tnl_create2(dev); 329 if (err < 0) 330 goto failed_free; 331 332 return t; 333 334 failed_free: 335 ip6_dev_free(dev); 336 failed: 337 return NULL; 338 } 339 340 /** 341 * ip6_tnl_locate - find or create tunnel matching given parameters 342 * @p: tunnel parameters 343 * @create: != 0 if allowed to create new tunnel if no match found 344 * 345 * Description: 346 * ip6_tnl_locate() first tries to locate an existing tunnel 347 * based on @parms. If this is unsuccessful, but @create is set a new 348 * tunnel device is created and registered for use. 349 * 350 * Return: 351 * matching tunnel or NULL 352 **/ 353 354 static struct ip6_tnl *ip6_tnl_locate(struct net *net, 355 struct __ip6_tnl_parm *p, int create) 356 { 357 const struct in6_addr *remote = &p->raddr; 358 const struct in6_addr *local = &p->laddr; 359 struct ip6_tnl __rcu **tp; 360 struct ip6_tnl *t; 361 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 362 363 for (tp = ip6_tnl_bucket(ip6n, p); 364 (t = rtnl_dereference(*tp)) != NULL; 365 tp = &t->next) { 366 if (ipv6_addr_equal(local, &t->parms.laddr) && 367 ipv6_addr_equal(remote, &t->parms.raddr)) { 368 if (create) 369 return NULL; 370 371 return t; 372 } 373 } 374 if (!create) 375 return NULL; 376 return ip6_tnl_create(net, p); 377 } 378 379 /** 380 * ip6_tnl_dev_uninit - tunnel device uninitializer 381 * @dev: the device to be destroyed 382 * 383 * Description: 384 * ip6_tnl_dev_uninit() removes tunnel from its list 385 **/ 386 387 static void 388 ip6_tnl_dev_uninit(struct net_device *dev) 389 { 390 struct ip6_tnl *t = netdev_priv(dev); 391 struct net *net = t->net; 392 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 393 394 if (dev == ip6n->fb_tnl_dev) 395 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 396 else 397 ip6_tnl_unlink(ip6n, t); 398 ip6_tnl_dst_reset(t); 399 dev_put(dev); 400 } 401 402 /** 403 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 404 * @skb: received socket buffer 405 * 406 * Return: 407 * 0 if none was found, 408 * else index to encapsulation limit 409 **/ 410 411 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw) 412 { 413 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw; 414 __u8 nexthdr = ipv6h->nexthdr; 415 __u16 off = sizeof(*ipv6h); 416 417 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 418 __u16 optlen = 0; 419 struct ipv6_opt_hdr *hdr; 420 if (raw + off + sizeof(*hdr) > skb->data && 421 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 422 break; 423 424 hdr = (struct ipv6_opt_hdr *) (raw + off); 425 if (nexthdr == NEXTHDR_FRAGMENT) { 426 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 427 if (frag_hdr->frag_off) 428 break; 429 optlen = 8; 430 } else if (nexthdr == NEXTHDR_AUTH) { 431 optlen = (hdr->hdrlen + 2) << 2; 432 } else { 433 optlen = ipv6_optlen(hdr); 434 } 435 if (nexthdr == NEXTHDR_DEST) { 436 __u16 i = off + 2; 437 while (1) { 438 struct ipv6_tlv_tnl_enc_lim *tel; 439 440 /* No more room for encapsulation limit */ 441 if (i + sizeof (*tel) > off + optlen) 442 break; 443 444 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 445 /* return index of option if found and valid */ 446 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 447 tel->length == 1) 448 return i; 449 /* else jump to next option */ 450 if (tel->type) 451 i += tel->length + 2; 452 else 453 i++; 454 } 455 } 456 nexthdr = hdr->nexthdr; 457 off += optlen; 458 } 459 return 0; 460 } 461 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim); 462 463 /** 464 * ip6_tnl_err - tunnel error handler 465 * 466 * Description: 467 * ip6_tnl_err() should handle errors in the tunnel according 468 * to the specifications in RFC 2473. 469 **/ 470 471 static int 472 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, 473 u8 *type, u8 *code, int *msg, __u32 *info, int offset) 474 { 475 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data; 476 struct ip6_tnl *t; 477 int rel_msg = 0; 478 u8 rel_type = ICMPV6_DEST_UNREACH; 479 u8 rel_code = ICMPV6_ADDR_UNREACH; 480 __u32 rel_info = 0; 481 __u16 len; 482 int err = -ENOENT; 483 484 /* If the packet doesn't contain the original IPv6 header we are 485 in trouble since we might need the source address for further 486 processing of the error. */ 487 488 rcu_read_lock(); 489 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, 490 &ipv6h->saddr)) == NULL) 491 goto out; 492 493 if (t->parms.proto != ipproto && t->parms.proto != 0) 494 goto out; 495 496 err = 0; 497 498 switch (*type) { 499 __u32 teli; 500 struct ipv6_tlv_tnl_enc_lim *tel; 501 __u32 mtu; 502 case ICMPV6_DEST_UNREACH: 503 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n", 504 t->parms.name); 505 rel_msg = 1; 506 break; 507 case ICMPV6_TIME_EXCEED: 508 if ((*code) == ICMPV6_EXC_HOPLIMIT) { 509 net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n", 510 t->parms.name); 511 rel_msg = 1; 512 } 513 break; 514 case ICMPV6_PARAMPROB: 515 teli = 0; 516 if ((*code) == ICMPV6_HDR_FIELD) 517 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data); 518 519 if (teli && teli == *info - 2) { 520 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 521 if (tel->encap_limit == 0) { 522 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n", 523 t->parms.name); 524 rel_msg = 1; 525 } 526 } else { 527 net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n", 528 t->parms.name); 529 } 530 break; 531 case ICMPV6_PKT_TOOBIG: 532 mtu = *info - offset; 533 if (mtu < IPV6_MIN_MTU) 534 mtu = IPV6_MIN_MTU; 535 t->dev->mtu = mtu; 536 537 if ((len = sizeof(*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 538 rel_type = ICMPV6_PKT_TOOBIG; 539 rel_code = 0; 540 rel_info = mtu; 541 rel_msg = 1; 542 } 543 break; 544 } 545 546 *type = rel_type; 547 *code = rel_code; 548 *info = rel_info; 549 *msg = rel_msg; 550 551 out: 552 rcu_read_unlock(); 553 return err; 554 } 555 556 static int 557 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 558 u8 type, u8 code, int offset, __be32 info) 559 { 560 int rel_msg = 0; 561 u8 rel_type = type; 562 u8 rel_code = code; 563 __u32 rel_info = ntohl(info); 564 int err; 565 struct sk_buff *skb2; 566 const struct iphdr *eiph; 567 struct rtable *rt; 568 struct flowi4 fl4; 569 570 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, 571 &rel_msg, &rel_info, offset); 572 if (err < 0) 573 return err; 574 575 if (rel_msg == 0) 576 return 0; 577 578 switch (rel_type) { 579 case ICMPV6_DEST_UNREACH: 580 if (rel_code != ICMPV6_ADDR_UNREACH) 581 return 0; 582 rel_type = ICMP_DEST_UNREACH; 583 rel_code = ICMP_HOST_UNREACH; 584 break; 585 case ICMPV6_PKT_TOOBIG: 586 if (rel_code != 0) 587 return 0; 588 rel_type = ICMP_DEST_UNREACH; 589 rel_code = ICMP_FRAG_NEEDED; 590 break; 591 case NDISC_REDIRECT: 592 rel_type = ICMP_REDIRECT; 593 rel_code = ICMP_REDIR_HOST; 594 default: 595 return 0; 596 } 597 598 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) 599 return 0; 600 601 skb2 = skb_clone(skb, GFP_ATOMIC); 602 if (!skb2) 603 return 0; 604 605 skb_dst_drop(skb2); 606 607 skb_pull(skb2, offset); 608 skb_reset_network_header(skb2); 609 eiph = ip_hdr(skb2); 610 611 /* Try to guess incoming interface */ 612 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 613 eiph->saddr, 0, 614 0, 0, 615 IPPROTO_IPIP, RT_TOS(eiph->tos), 0); 616 if (IS_ERR(rt)) 617 goto out; 618 619 skb2->dev = rt->dst.dev; 620 621 /* route "incoming" packet */ 622 if (rt->rt_flags & RTCF_LOCAL) { 623 ip_rt_put(rt); 624 rt = NULL; 625 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 626 eiph->daddr, eiph->saddr, 627 0, 0, 628 IPPROTO_IPIP, 629 RT_TOS(eiph->tos), 0); 630 if (IS_ERR(rt) || 631 rt->dst.dev->type != ARPHRD_TUNNEL) { 632 if (!IS_ERR(rt)) 633 ip_rt_put(rt); 634 goto out; 635 } 636 skb_dst_set(skb2, &rt->dst); 637 } else { 638 ip_rt_put(rt); 639 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, 640 skb2->dev) || 641 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) 642 goto out; 643 } 644 645 /* change mtu on this route */ 646 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { 647 if (rel_info > dst_mtu(skb_dst(skb2))) 648 goto out; 649 650 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info); 651 } 652 if (rel_type == ICMP_REDIRECT) 653 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2); 654 655 icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); 656 657 out: 658 kfree_skb(skb2); 659 return 0; 660 } 661 662 static int 663 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 664 u8 type, u8 code, int offset, __be32 info) 665 { 666 int rel_msg = 0; 667 u8 rel_type = type; 668 u8 rel_code = code; 669 __u32 rel_info = ntohl(info); 670 int err; 671 672 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, 673 &rel_msg, &rel_info, offset); 674 if (err < 0) 675 return err; 676 677 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { 678 struct rt6_info *rt; 679 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 680 681 if (!skb2) 682 return 0; 683 684 skb_dst_drop(skb2); 685 skb_pull(skb2, offset); 686 skb_reset_network_header(skb2); 687 688 /* Try to guess incoming interface */ 689 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, 690 NULL, 0, 0); 691 692 if (rt && rt->dst.dev) 693 skb2->dev = rt->dst.dev; 694 695 icmpv6_send(skb2, rel_type, rel_code, rel_info); 696 697 ip6_rt_put(rt); 698 699 kfree_skb(skb2); 700 } 701 702 return 0; 703 } 704 705 static int ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 706 const struct ipv6hdr *ipv6h, 707 struct sk_buff *skb) 708 { 709 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; 710 711 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 712 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); 713 714 return IP6_ECN_decapsulate(ipv6h, skb); 715 } 716 717 static int ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 718 const struct ipv6hdr *ipv6h, 719 struct sk_buff *skb) 720 { 721 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 722 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); 723 724 return IP6_ECN_decapsulate(ipv6h, skb); 725 } 726 727 __u32 ip6_tnl_get_cap(struct ip6_tnl *t, 728 const struct in6_addr *laddr, 729 const struct in6_addr *raddr) 730 { 731 struct __ip6_tnl_parm *p = &t->parms; 732 int ltype = ipv6_addr_type(laddr); 733 int rtype = ipv6_addr_type(raddr); 734 __u32 flags = 0; 735 736 if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) { 737 flags = IP6_TNL_F_CAP_PER_PACKET; 738 } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 739 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 740 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 741 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 742 if (ltype&IPV6_ADDR_UNICAST) 743 flags |= IP6_TNL_F_CAP_XMIT; 744 if (rtype&IPV6_ADDR_UNICAST) 745 flags |= IP6_TNL_F_CAP_RCV; 746 } 747 return flags; 748 } 749 EXPORT_SYMBOL(ip6_tnl_get_cap); 750 751 /* called with rcu_read_lock() */ 752 int ip6_tnl_rcv_ctl(struct ip6_tnl *t, 753 const struct in6_addr *laddr, 754 const struct in6_addr *raddr) 755 { 756 struct __ip6_tnl_parm *p = &t->parms; 757 int ret = 0; 758 struct net *net = t->net; 759 760 if ((p->flags & IP6_TNL_F_CAP_RCV) || 761 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) && 762 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) { 763 struct net_device *ldev = NULL; 764 765 if (p->link) 766 ldev = dev_get_by_index_rcu(net, p->link); 767 768 if ((ipv6_addr_is_multicast(laddr) || 769 likely(ipv6_chk_addr(net, laddr, ldev, 0))) && 770 likely(!ipv6_chk_addr(net, raddr, NULL, 0))) 771 ret = 1; 772 } 773 return ret; 774 } 775 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl); 776 777 /** 778 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally 779 * @skb: received socket buffer 780 * @protocol: ethernet protocol ID 781 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN 782 * 783 * Return: 0 784 **/ 785 786 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, 787 __u8 ipproto, 788 int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t, 789 const struct ipv6hdr *ipv6h, 790 struct sk_buff *skb)) 791 { 792 struct ip6_tnl *t; 793 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 794 int err; 795 796 rcu_read_lock(); 797 798 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, 799 &ipv6h->daddr)) != NULL) { 800 struct pcpu_sw_netstats *tstats; 801 802 if (t->parms.proto != ipproto && t->parms.proto != 0) { 803 rcu_read_unlock(); 804 goto discard; 805 } 806 807 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 808 rcu_read_unlock(); 809 goto discard; 810 } 811 812 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 813 t->dev->stats.rx_dropped++; 814 rcu_read_unlock(); 815 goto discard; 816 } 817 skb->mac_header = skb->network_header; 818 skb_reset_network_header(skb); 819 skb->protocol = htons(protocol); 820 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 821 822 __skb_tunnel_rx(skb, t->dev, t->net); 823 824 err = dscp_ecn_decapsulate(t, ipv6h, skb); 825 if (unlikely(err)) { 826 if (log_ecn_error) 827 net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n", 828 &ipv6h->saddr, 829 ipv6_get_dsfield(ipv6h)); 830 if (err > 1) { 831 ++t->dev->stats.rx_frame_errors; 832 ++t->dev->stats.rx_errors; 833 rcu_read_unlock(); 834 goto discard; 835 } 836 } 837 838 tstats = this_cpu_ptr(t->dev->tstats); 839 u64_stats_update_begin(&tstats->syncp); 840 tstats->rx_packets++; 841 tstats->rx_bytes += skb->len; 842 u64_stats_update_end(&tstats->syncp); 843 844 netif_rx(skb); 845 846 rcu_read_unlock(); 847 return 0; 848 } 849 rcu_read_unlock(); 850 return 1; 851 852 discard: 853 kfree_skb(skb); 854 return 0; 855 } 856 857 static int ip4ip6_rcv(struct sk_buff *skb) 858 { 859 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, 860 ip4ip6_dscp_ecn_decapsulate); 861 } 862 863 static int ip6ip6_rcv(struct sk_buff *skb) 864 { 865 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, 866 ip6ip6_dscp_ecn_decapsulate); 867 } 868 869 struct ipv6_tel_txoption { 870 struct ipv6_txoptions ops; 871 __u8 dst_opt[8]; 872 }; 873 874 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 875 { 876 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 877 878 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 879 opt->dst_opt[3] = 1; 880 opt->dst_opt[4] = encap_limit; 881 opt->dst_opt[5] = IPV6_TLV_PADN; 882 opt->dst_opt[6] = 1; 883 884 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 885 opt->ops.opt_nflen = 8; 886 } 887 888 /** 889 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 890 * @t: the outgoing tunnel device 891 * @hdr: IPv6 header from the incoming packet 892 * 893 * Description: 894 * Avoid trivial tunneling loop by checking that tunnel exit-point 895 * doesn't match source of incoming packet. 896 * 897 * Return: 898 * 1 if conflict, 899 * 0 else 900 **/ 901 902 static inline bool 903 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 904 { 905 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 906 } 907 908 int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 909 { 910 struct __ip6_tnl_parm *p = &t->parms; 911 int ret = 0; 912 struct net *net = t->net; 913 914 if (p->flags & IP6_TNL_F_CAP_XMIT) { 915 struct net_device *ldev = NULL; 916 917 rcu_read_lock(); 918 if (p->link) 919 ldev = dev_get_by_index_rcu(net, p->link); 920 921 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) 922 pr_warn("%s xmit: Local address not yet configured!\n", 923 p->name); 924 else if (!ipv6_addr_is_multicast(&p->raddr) && 925 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) 926 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n", 927 p->name); 928 else 929 ret = 1; 930 rcu_read_unlock(); 931 } 932 return ret; 933 } 934 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl); 935 936 /** 937 * ip6_tnl_xmit2 - encapsulate packet and send 938 * @skb: the outgoing socket buffer 939 * @dev: the outgoing tunnel device 940 * @dsfield: dscp code for outer header 941 * @fl: flow of tunneled packet 942 * @encap_limit: encapsulation limit 943 * @pmtu: Path MTU is stored if packet is too big 944 * 945 * Description: 946 * Build new header and do some sanity checks on the packet before sending 947 * it. 948 * 949 * Return: 950 * 0 on success 951 * -1 fail 952 * %-EMSGSIZE message too big. return mtu in this case. 953 **/ 954 955 static int ip6_tnl_xmit2(struct sk_buff *skb, 956 struct net_device *dev, 957 __u8 dsfield, 958 struct flowi6 *fl6, 959 int encap_limit, 960 __u32 *pmtu) 961 { 962 struct ip6_tnl *t = netdev_priv(dev); 963 struct net *net = t->net; 964 struct net_device_stats *stats = &t->dev->stats; 965 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 966 struct ipv6_tel_txoption opt; 967 struct dst_entry *dst = NULL, *ndst = NULL; 968 struct net_device *tdev; 969 int mtu; 970 unsigned int max_headroom = sizeof(struct ipv6hdr); 971 u8 proto; 972 int err = -1; 973 974 if (!fl6->flowi6_mark) 975 dst = ip6_tnl_dst_check(t); 976 if (!dst) { 977 ndst = ip6_route_output(net, NULL, fl6); 978 979 if (ndst->error) 980 goto tx_err_link_failure; 981 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0); 982 if (IS_ERR(ndst)) { 983 err = PTR_ERR(ndst); 984 ndst = NULL; 985 goto tx_err_link_failure; 986 } 987 dst = ndst; 988 } 989 990 tdev = dst->dev; 991 992 if (tdev == dev) { 993 stats->collisions++; 994 net_warn_ratelimited("%s: Local routing loop detected!\n", 995 t->parms.name); 996 goto tx_err_dst_release; 997 } 998 mtu = dst_mtu(dst) - sizeof(*ipv6h); 999 if (encap_limit >= 0) { 1000 max_headroom += 8; 1001 mtu -= 8; 1002 } 1003 if (mtu < IPV6_MIN_MTU) 1004 mtu = IPV6_MIN_MTU; 1005 if (skb_dst(skb)) 1006 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 1007 if (skb->len > mtu) { 1008 *pmtu = mtu; 1009 err = -EMSGSIZE; 1010 goto tx_err_dst_release; 1011 } 1012 1013 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 1014 1015 /* 1016 * Okay, now see if we can stuff it in the buffer as-is. 1017 */ 1018 max_headroom += LL_RESERVED_SPACE(tdev); 1019 1020 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 1021 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 1022 struct sk_buff *new_skb; 1023 1024 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 1025 goto tx_err_dst_release; 1026 1027 if (skb->sk) 1028 skb_set_owner_w(new_skb, skb->sk); 1029 consume_skb(skb); 1030 skb = new_skb; 1031 } 1032 if (fl6->flowi6_mark) { 1033 skb_dst_set(skb, dst); 1034 ndst = NULL; 1035 } else { 1036 skb_dst_set_noref(skb, dst); 1037 } 1038 skb->transport_header = skb->network_header; 1039 1040 proto = fl6->flowi6_proto; 1041 if (encap_limit >= 0) { 1042 init_tel_txopt(&opt, encap_limit); 1043 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 1044 } 1045 1046 if (likely(!skb->encapsulation)) { 1047 skb_reset_inner_headers(skb); 1048 skb->encapsulation = 1; 1049 } 1050 1051 skb_push(skb, sizeof(struct ipv6hdr)); 1052 skb_reset_network_header(skb); 1053 ipv6h = ipv6_hdr(skb); 1054 ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield), 1055 ip6_make_flowlabel(net, skb, fl6->flowlabel, false)); 1056 ipv6h->hop_limit = t->parms.hop_limit; 1057 ipv6h->nexthdr = proto; 1058 ipv6h->saddr = fl6->saddr; 1059 ipv6h->daddr = fl6->daddr; 1060 ip6tunnel_xmit(skb, dev); 1061 if (ndst) 1062 ip6_tnl_dst_store(t, ndst); 1063 return 0; 1064 tx_err_link_failure: 1065 stats->tx_carrier_errors++; 1066 dst_link_failure(skb); 1067 tx_err_dst_release: 1068 dst_release(ndst); 1069 return err; 1070 } 1071 1072 static inline int 1073 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1074 { 1075 struct ip6_tnl *t = netdev_priv(dev); 1076 const struct iphdr *iph = ip_hdr(skb); 1077 int encap_limit = -1; 1078 struct flowi6 fl6; 1079 __u8 dsfield; 1080 __u32 mtu; 1081 int err; 1082 1083 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || 1084 !ip6_tnl_xmit_ctl(t)) 1085 return -1; 1086 1087 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1088 encap_limit = t->parms.encap_limit; 1089 1090 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); 1091 fl6.flowi6_proto = IPPROTO_IPIP; 1092 1093 dsfield = ipv4_get_dsfield(iph); 1094 1095 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1096 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) 1097 & IPV6_TCLASS_MASK; 1098 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1099 fl6.flowi6_mark = skb->mark; 1100 1101 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1102 if (err != 0) { 1103 /* XXX: send ICMP error even if DF is not set. */ 1104 if (err == -EMSGSIZE) 1105 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 1106 htonl(mtu)); 1107 return -1; 1108 } 1109 1110 return 0; 1111 } 1112 1113 static inline int 1114 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1115 { 1116 struct ip6_tnl *t = netdev_priv(dev); 1117 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1118 int encap_limit = -1; 1119 __u16 offset; 1120 struct flowi6 fl6; 1121 __u8 dsfield; 1122 __u32 mtu; 1123 int err; 1124 1125 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 1126 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) 1127 return -1; 1128 1129 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb)); 1130 if (offset > 0) { 1131 struct ipv6_tlv_tnl_enc_lim *tel; 1132 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; 1133 if (tel->encap_limit == 0) { 1134 icmpv6_send(skb, ICMPV6_PARAMPROB, 1135 ICMPV6_HDR_FIELD, offset + 2); 1136 return -1; 1137 } 1138 encap_limit = tel->encap_limit - 1; 1139 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1140 encap_limit = t->parms.encap_limit; 1141 1142 memcpy(&fl6, &t->fl.u.ip6, sizeof(fl6)); 1143 fl6.flowi6_proto = IPPROTO_IPV6; 1144 1145 dsfield = ipv6_get_dsfield(ipv6h); 1146 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1147 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 1148 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL) 1149 fl6.flowlabel |= ip6_flowlabel(ipv6h); 1150 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1151 fl6.flowi6_mark = skb->mark; 1152 1153 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1154 if (err != 0) { 1155 if (err == -EMSGSIZE) 1156 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1157 return -1; 1158 } 1159 1160 return 0; 1161 } 1162 1163 static netdev_tx_t 1164 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1165 { 1166 struct ip6_tnl *t = netdev_priv(dev); 1167 struct net_device_stats *stats = &t->dev->stats; 1168 int ret; 1169 1170 switch (skb->protocol) { 1171 case htons(ETH_P_IP): 1172 ret = ip4ip6_tnl_xmit(skb, dev); 1173 break; 1174 case htons(ETH_P_IPV6): 1175 ret = ip6ip6_tnl_xmit(skb, dev); 1176 break; 1177 default: 1178 goto tx_err; 1179 } 1180 1181 if (ret < 0) 1182 goto tx_err; 1183 1184 return NETDEV_TX_OK; 1185 1186 tx_err: 1187 stats->tx_errors++; 1188 stats->tx_dropped++; 1189 kfree_skb(skb); 1190 return NETDEV_TX_OK; 1191 } 1192 1193 static void ip6_tnl_link_config(struct ip6_tnl *t) 1194 { 1195 struct net_device *dev = t->dev; 1196 struct __ip6_tnl_parm *p = &t->parms; 1197 struct flowi6 *fl6 = &t->fl.u.ip6; 1198 1199 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 1200 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 1201 1202 /* Set up flowi template */ 1203 fl6->saddr = p->laddr; 1204 fl6->daddr = p->raddr; 1205 fl6->flowi6_oif = p->link; 1206 fl6->flowlabel = 0; 1207 1208 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 1209 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 1210 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1211 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 1212 1213 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET); 1214 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 1215 1216 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 1217 dev->flags |= IFF_POINTOPOINT; 1218 else 1219 dev->flags &= ~IFF_POINTOPOINT; 1220 1221 dev->iflink = p->link; 1222 1223 if (p->flags & IP6_TNL_F_CAP_XMIT) { 1224 int strict = (ipv6_addr_type(&p->raddr) & 1225 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 1226 1227 struct rt6_info *rt = rt6_lookup(t->net, 1228 &p->raddr, &p->laddr, 1229 p->link, strict); 1230 1231 if (rt == NULL) 1232 return; 1233 1234 if (rt->dst.dev) { 1235 dev->hard_header_len = rt->dst.dev->hard_header_len + 1236 sizeof(struct ipv6hdr); 1237 1238 dev->mtu = rt->dst.dev->mtu - sizeof(struct ipv6hdr); 1239 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1240 dev->mtu -= 8; 1241 1242 if (dev->mtu < IPV6_MIN_MTU) 1243 dev->mtu = IPV6_MIN_MTU; 1244 } 1245 ip6_rt_put(rt); 1246 } 1247 } 1248 1249 /** 1250 * ip6_tnl_change - update the tunnel parameters 1251 * @t: tunnel to be changed 1252 * @p: tunnel configuration parameters 1253 * 1254 * Description: 1255 * ip6_tnl_change() updates the tunnel parameters 1256 **/ 1257 1258 static int 1259 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p) 1260 { 1261 t->parms.laddr = p->laddr; 1262 t->parms.raddr = p->raddr; 1263 t->parms.flags = p->flags; 1264 t->parms.hop_limit = p->hop_limit; 1265 t->parms.encap_limit = p->encap_limit; 1266 t->parms.flowinfo = p->flowinfo; 1267 t->parms.link = p->link; 1268 t->parms.proto = p->proto; 1269 ip6_tnl_dst_reset(t); 1270 ip6_tnl_link_config(t); 1271 return 0; 1272 } 1273 1274 static int ip6_tnl_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p) 1275 { 1276 struct net *net = t->net; 1277 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1278 int err; 1279 1280 ip6_tnl_unlink(ip6n, t); 1281 synchronize_net(); 1282 err = ip6_tnl_change(t, p); 1283 ip6_tnl_link(ip6n, t); 1284 netdev_state_change(t->dev); 1285 return err; 1286 } 1287 1288 static void 1289 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u) 1290 { 1291 p->laddr = u->laddr; 1292 p->raddr = u->raddr; 1293 p->flags = u->flags; 1294 p->hop_limit = u->hop_limit; 1295 p->encap_limit = u->encap_limit; 1296 p->flowinfo = u->flowinfo; 1297 p->link = u->link; 1298 p->proto = u->proto; 1299 memcpy(p->name, u->name, sizeof(u->name)); 1300 } 1301 1302 static void 1303 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p) 1304 { 1305 u->laddr = p->laddr; 1306 u->raddr = p->raddr; 1307 u->flags = p->flags; 1308 u->hop_limit = p->hop_limit; 1309 u->encap_limit = p->encap_limit; 1310 u->flowinfo = p->flowinfo; 1311 u->link = p->link; 1312 u->proto = p->proto; 1313 memcpy(u->name, p->name, sizeof(u->name)); 1314 } 1315 1316 /** 1317 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace 1318 * @dev: virtual device associated with tunnel 1319 * @ifr: parameters passed from userspace 1320 * @cmd: command to be performed 1321 * 1322 * Description: 1323 * ip6_tnl_ioctl() is used for managing IPv6 tunnels 1324 * from userspace. 1325 * 1326 * The possible commands are the following: 1327 * %SIOCGETTUNNEL: get tunnel parameters for device 1328 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 1329 * %SIOCCHGTUNNEL: change tunnel parameters to those given 1330 * %SIOCDELTUNNEL: delete tunnel 1331 * 1332 * The fallback device "ip6tnl0", created during module 1333 * initialization, can be used for creating other tunnel devices. 1334 * 1335 * Return: 1336 * 0 on success, 1337 * %-EFAULT if unable to copy data to or from userspace, 1338 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 1339 * %-EINVAL if passed tunnel parameters are invalid, 1340 * %-EEXIST if changing a tunnel's parameters would cause a conflict 1341 * %-ENODEV if attempting to change or delete a nonexisting device 1342 **/ 1343 1344 static int 1345 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1346 { 1347 int err = 0; 1348 struct ip6_tnl_parm p; 1349 struct __ip6_tnl_parm p1; 1350 struct ip6_tnl *t = netdev_priv(dev); 1351 struct net *net = t->net; 1352 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1353 1354 switch (cmd) { 1355 case SIOCGETTUNNEL: 1356 if (dev == ip6n->fb_tnl_dev) { 1357 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 1358 err = -EFAULT; 1359 break; 1360 } 1361 ip6_tnl_parm_from_user(&p1, &p); 1362 t = ip6_tnl_locate(net, &p1, 0); 1363 if (t == NULL) 1364 t = netdev_priv(dev); 1365 } else { 1366 memset(&p, 0, sizeof(p)); 1367 } 1368 ip6_tnl_parm_to_user(&p, &t->parms); 1369 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) { 1370 err = -EFAULT; 1371 } 1372 break; 1373 case SIOCADDTUNNEL: 1374 case SIOCCHGTUNNEL: 1375 err = -EPERM; 1376 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1377 break; 1378 err = -EFAULT; 1379 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1380 break; 1381 err = -EINVAL; 1382 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && 1383 p.proto != 0) 1384 break; 1385 ip6_tnl_parm_from_user(&p1, &p); 1386 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL); 1387 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 1388 if (t != NULL) { 1389 if (t->dev != dev) { 1390 err = -EEXIST; 1391 break; 1392 } 1393 } else 1394 t = netdev_priv(dev); 1395 1396 err = ip6_tnl_update(t, &p1); 1397 } 1398 if (t) { 1399 err = 0; 1400 ip6_tnl_parm_to_user(&p, &t->parms); 1401 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 1402 err = -EFAULT; 1403 1404 } else 1405 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1406 break; 1407 case SIOCDELTUNNEL: 1408 err = -EPERM; 1409 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 1410 break; 1411 1412 if (dev == ip6n->fb_tnl_dev) { 1413 err = -EFAULT; 1414 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 1415 break; 1416 err = -ENOENT; 1417 ip6_tnl_parm_from_user(&p1, &p); 1418 t = ip6_tnl_locate(net, &p1, 0); 1419 if (t == NULL) 1420 break; 1421 err = -EPERM; 1422 if (t->dev == ip6n->fb_tnl_dev) 1423 break; 1424 dev = t->dev; 1425 } 1426 err = 0; 1427 unregister_netdevice(dev); 1428 break; 1429 default: 1430 err = -EINVAL; 1431 } 1432 return err; 1433 } 1434 1435 /** 1436 * ip6_tnl_change_mtu - change mtu manually for tunnel device 1437 * @dev: virtual device associated with tunnel 1438 * @new_mtu: the new mtu 1439 * 1440 * Return: 1441 * 0 on success, 1442 * %-EINVAL if mtu too small 1443 **/ 1444 1445 static int 1446 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1447 { 1448 struct ip6_tnl *tnl = netdev_priv(dev); 1449 1450 if (tnl->parms.proto == IPPROTO_IPIP) { 1451 if (new_mtu < 68) 1452 return -EINVAL; 1453 } else { 1454 if (new_mtu < IPV6_MIN_MTU) 1455 return -EINVAL; 1456 } 1457 if (new_mtu > 0xFFF8 - dev->hard_header_len) 1458 return -EINVAL; 1459 dev->mtu = new_mtu; 1460 return 0; 1461 } 1462 1463 1464 static const struct net_device_ops ip6_tnl_netdev_ops = { 1465 .ndo_uninit = ip6_tnl_dev_uninit, 1466 .ndo_start_xmit = ip6_tnl_xmit, 1467 .ndo_do_ioctl = ip6_tnl_ioctl, 1468 .ndo_change_mtu = ip6_tnl_change_mtu, 1469 .ndo_get_stats = ip6_get_stats, 1470 }; 1471 1472 1473 /** 1474 * ip6_tnl_dev_setup - setup virtual tunnel device 1475 * @dev: virtual device associated with tunnel 1476 * 1477 * Description: 1478 * Initialize function pointers and device parameters 1479 **/ 1480 1481 static void ip6_tnl_dev_setup(struct net_device *dev) 1482 { 1483 struct ip6_tnl *t; 1484 1485 dev->netdev_ops = &ip6_tnl_netdev_ops; 1486 dev->destructor = ip6_dev_free; 1487 1488 dev->type = ARPHRD_TUNNEL6; 1489 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr); 1490 dev->mtu = ETH_DATA_LEN - sizeof(struct ipv6hdr); 1491 t = netdev_priv(dev); 1492 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1493 dev->mtu -= 8; 1494 dev->flags |= IFF_NOARP; 1495 dev->addr_len = sizeof(struct in6_addr); 1496 netif_keep_dst(dev); 1497 /* This perm addr will be used as interface identifier by IPv6 */ 1498 dev->addr_assign_type = NET_ADDR_RANDOM; 1499 eth_random_addr(dev->perm_addr); 1500 } 1501 1502 1503 /** 1504 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1505 * @dev: virtual device associated with tunnel 1506 **/ 1507 1508 static inline int 1509 ip6_tnl_dev_init_gen(struct net_device *dev) 1510 { 1511 struct ip6_tnl *t = netdev_priv(dev); 1512 1513 t->dev = dev; 1514 t->net = dev_net(dev); 1515 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1516 if (!dev->tstats) 1517 return -ENOMEM; 1518 return 0; 1519 } 1520 1521 /** 1522 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1523 * @dev: virtual device associated with tunnel 1524 **/ 1525 1526 static int ip6_tnl_dev_init(struct net_device *dev) 1527 { 1528 struct ip6_tnl *t = netdev_priv(dev); 1529 int err = ip6_tnl_dev_init_gen(dev); 1530 1531 if (err) 1532 return err; 1533 ip6_tnl_link_config(t); 1534 return 0; 1535 } 1536 1537 /** 1538 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1539 * @dev: fallback device 1540 * 1541 * Return: 0 1542 **/ 1543 1544 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev) 1545 { 1546 struct ip6_tnl *t = netdev_priv(dev); 1547 struct net *net = dev_net(dev); 1548 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1549 int err = ip6_tnl_dev_init_gen(dev); 1550 1551 if (err) 1552 return err; 1553 1554 t->parms.proto = IPPROTO_IPV6; 1555 dev_hold(dev); 1556 1557 ip6_tnl_link_config(t); 1558 1559 rcu_assign_pointer(ip6n->tnls_wc[0], t); 1560 return 0; 1561 } 1562 1563 static int ip6_tnl_validate(struct nlattr *tb[], struct nlattr *data[]) 1564 { 1565 u8 proto; 1566 1567 if (!data || !data[IFLA_IPTUN_PROTO]) 1568 return 0; 1569 1570 proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1571 if (proto != IPPROTO_IPV6 && 1572 proto != IPPROTO_IPIP && 1573 proto != 0) 1574 return -EINVAL; 1575 1576 return 0; 1577 } 1578 1579 static void ip6_tnl_netlink_parms(struct nlattr *data[], 1580 struct __ip6_tnl_parm *parms) 1581 { 1582 memset(parms, 0, sizeof(*parms)); 1583 1584 if (!data) 1585 return; 1586 1587 if (data[IFLA_IPTUN_LINK]) 1588 parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]); 1589 1590 if (data[IFLA_IPTUN_LOCAL]) 1591 nla_memcpy(&parms->laddr, data[IFLA_IPTUN_LOCAL], 1592 sizeof(struct in6_addr)); 1593 1594 if (data[IFLA_IPTUN_REMOTE]) 1595 nla_memcpy(&parms->raddr, data[IFLA_IPTUN_REMOTE], 1596 sizeof(struct in6_addr)); 1597 1598 if (data[IFLA_IPTUN_TTL]) 1599 parms->hop_limit = nla_get_u8(data[IFLA_IPTUN_TTL]); 1600 1601 if (data[IFLA_IPTUN_ENCAP_LIMIT]) 1602 parms->encap_limit = nla_get_u8(data[IFLA_IPTUN_ENCAP_LIMIT]); 1603 1604 if (data[IFLA_IPTUN_FLOWINFO]) 1605 parms->flowinfo = nla_get_be32(data[IFLA_IPTUN_FLOWINFO]); 1606 1607 if (data[IFLA_IPTUN_FLAGS]) 1608 parms->flags = nla_get_u32(data[IFLA_IPTUN_FLAGS]); 1609 1610 if (data[IFLA_IPTUN_PROTO]) 1611 parms->proto = nla_get_u8(data[IFLA_IPTUN_PROTO]); 1612 } 1613 1614 static int ip6_tnl_newlink(struct net *src_net, struct net_device *dev, 1615 struct nlattr *tb[], struct nlattr *data[]) 1616 { 1617 struct net *net = dev_net(dev); 1618 struct ip6_tnl *nt; 1619 1620 nt = netdev_priv(dev); 1621 ip6_tnl_netlink_parms(data, &nt->parms); 1622 1623 if (ip6_tnl_locate(net, &nt->parms, 0)) 1624 return -EEXIST; 1625 1626 return ip6_tnl_create2(dev); 1627 } 1628 1629 static int ip6_tnl_changelink(struct net_device *dev, struct nlattr *tb[], 1630 struct nlattr *data[]) 1631 { 1632 struct ip6_tnl *t = netdev_priv(dev); 1633 struct __ip6_tnl_parm p; 1634 struct net *net = t->net; 1635 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1636 1637 if (dev == ip6n->fb_tnl_dev) 1638 return -EINVAL; 1639 1640 ip6_tnl_netlink_parms(data, &p); 1641 1642 t = ip6_tnl_locate(net, &p, 0); 1643 1644 if (t) { 1645 if (t->dev != dev) 1646 return -EEXIST; 1647 } else 1648 t = netdev_priv(dev); 1649 1650 return ip6_tnl_update(t, &p); 1651 } 1652 1653 static void ip6_tnl_dellink(struct net_device *dev, struct list_head *head) 1654 { 1655 struct net *net = dev_net(dev); 1656 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1657 1658 if (dev != ip6n->fb_tnl_dev) 1659 unregister_netdevice_queue(dev, head); 1660 } 1661 1662 static size_t ip6_tnl_get_size(const struct net_device *dev) 1663 { 1664 return 1665 /* IFLA_IPTUN_LINK */ 1666 nla_total_size(4) + 1667 /* IFLA_IPTUN_LOCAL */ 1668 nla_total_size(sizeof(struct in6_addr)) + 1669 /* IFLA_IPTUN_REMOTE */ 1670 nla_total_size(sizeof(struct in6_addr)) + 1671 /* IFLA_IPTUN_TTL */ 1672 nla_total_size(1) + 1673 /* IFLA_IPTUN_ENCAP_LIMIT */ 1674 nla_total_size(1) + 1675 /* IFLA_IPTUN_FLOWINFO */ 1676 nla_total_size(4) + 1677 /* IFLA_IPTUN_FLAGS */ 1678 nla_total_size(4) + 1679 /* IFLA_IPTUN_PROTO */ 1680 nla_total_size(1) + 1681 0; 1682 } 1683 1684 static int ip6_tnl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1685 { 1686 struct ip6_tnl *tunnel = netdev_priv(dev); 1687 struct __ip6_tnl_parm *parm = &tunnel->parms; 1688 1689 if (nla_put_u32(skb, IFLA_IPTUN_LINK, parm->link) || 1690 nla_put(skb, IFLA_IPTUN_LOCAL, sizeof(struct in6_addr), 1691 &parm->laddr) || 1692 nla_put(skb, IFLA_IPTUN_REMOTE, sizeof(struct in6_addr), 1693 &parm->raddr) || 1694 nla_put_u8(skb, IFLA_IPTUN_TTL, parm->hop_limit) || 1695 nla_put_u8(skb, IFLA_IPTUN_ENCAP_LIMIT, parm->encap_limit) || 1696 nla_put_be32(skb, IFLA_IPTUN_FLOWINFO, parm->flowinfo) || 1697 nla_put_u32(skb, IFLA_IPTUN_FLAGS, parm->flags) || 1698 nla_put_u8(skb, IFLA_IPTUN_PROTO, parm->proto)) 1699 goto nla_put_failure; 1700 return 0; 1701 1702 nla_put_failure: 1703 return -EMSGSIZE; 1704 } 1705 1706 static const struct nla_policy ip6_tnl_policy[IFLA_IPTUN_MAX + 1] = { 1707 [IFLA_IPTUN_LINK] = { .type = NLA_U32 }, 1708 [IFLA_IPTUN_LOCAL] = { .len = sizeof(struct in6_addr) }, 1709 [IFLA_IPTUN_REMOTE] = { .len = sizeof(struct in6_addr) }, 1710 [IFLA_IPTUN_TTL] = { .type = NLA_U8 }, 1711 [IFLA_IPTUN_ENCAP_LIMIT] = { .type = NLA_U8 }, 1712 [IFLA_IPTUN_FLOWINFO] = { .type = NLA_U32 }, 1713 [IFLA_IPTUN_FLAGS] = { .type = NLA_U32 }, 1714 [IFLA_IPTUN_PROTO] = { .type = NLA_U8 }, 1715 }; 1716 1717 static struct rtnl_link_ops ip6_link_ops __read_mostly = { 1718 .kind = "ip6tnl", 1719 .maxtype = IFLA_IPTUN_MAX, 1720 .policy = ip6_tnl_policy, 1721 .priv_size = sizeof(struct ip6_tnl), 1722 .setup = ip6_tnl_dev_setup, 1723 .validate = ip6_tnl_validate, 1724 .newlink = ip6_tnl_newlink, 1725 .changelink = ip6_tnl_changelink, 1726 .dellink = ip6_tnl_dellink, 1727 .get_size = ip6_tnl_get_size, 1728 .fill_info = ip6_tnl_fill_info, 1729 }; 1730 1731 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { 1732 .handler = ip4ip6_rcv, 1733 .err_handler = ip4ip6_err, 1734 .priority = 1, 1735 }; 1736 1737 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { 1738 .handler = ip6ip6_rcv, 1739 .err_handler = ip6ip6_err, 1740 .priority = 1, 1741 }; 1742 1743 static void __net_exit ip6_tnl_destroy_tunnels(struct net *net) 1744 { 1745 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1746 struct net_device *dev, *aux; 1747 int h; 1748 struct ip6_tnl *t; 1749 LIST_HEAD(list); 1750 1751 for_each_netdev_safe(net, dev, aux) 1752 if (dev->rtnl_link_ops == &ip6_link_ops) 1753 unregister_netdevice_queue(dev, &list); 1754 1755 for (h = 0; h < HASH_SIZE; h++) { 1756 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1757 while (t != NULL) { 1758 /* If dev is in the same netns, it has already 1759 * been added to the list by the previous loop. 1760 */ 1761 if (!net_eq(dev_net(t->dev), net)) 1762 unregister_netdevice_queue(t->dev, &list); 1763 t = rtnl_dereference(t->next); 1764 } 1765 } 1766 1767 unregister_netdevice_many(&list); 1768 } 1769 1770 static int __net_init ip6_tnl_init_net(struct net *net) 1771 { 1772 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1773 struct ip6_tnl *t = NULL; 1774 int err; 1775 1776 ip6n->tnls[0] = ip6n->tnls_wc; 1777 ip6n->tnls[1] = ip6n->tnls_r_l; 1778 1779 err = -ENOMEM; 1780 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1781 NET_NAME_UNKNOWN, ip6_tnl_dev_setup); 1782 1783 if (!ip6n->fb_tnl_dev) 1784 goto err_alloc_dev; 1785 dev_net_set(ip6n->fb_tnl_dev, net); 1786 ip6n->fb_tnl_dev->rtnl_link_ops = &ip6_link_ops; 1787 /* FB netdevice is special: we have one, and only one per netns. 1788 * Allowing to move it to another netns is clearly unsafe. 1789 */ 1790 ip6n->fb_tnl_dev->features |= NETIF_F_NETNS_LOCAL; 1791 1792 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1793 if (err < 0) 1794 goto err_register; 1795 1796 err = register_netdev(ip6n->fb_tnl_dev); 1797 if (err < 0) 1798 goto err_register; 1799 1800 t = netdev_priv(ip6n->fb_tnl_dev); 1801 1802 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1803 return 0; 1804 1805 err_register: 1806 ip6_dev_free(ip6n->fb_tnl_dev); 1807 err_alloc_dev: 1808 return err; 1809 } 1810 1811 static void __net_exit ip6_tnl_exit_net(struct net *net) 1812 { 1813 rtnl_lock(); 1814 ip6_tnl_destroy_tunnels(net); 1815 rtnl_unlock(); 1816 } 1817 1818 static struct pernet_operations ip6_tnl_net_ops = { 1819 .init = ip6_tnl_init_net, 1820 .exit = ip6_tnl_exit_net, 1821 .id = &ip6_tnl_net_id, 1822 .size = sizeof(struct ip6_tnl_net), 1823 }; 1824 1825 /** 1826 * ip6_tunnel_init - register protocol and reserve needed resources 1827 * 1828 * Return: 0 on success 1829 **/ 1830 1831 static int __init ip6_tunnel_init(void) 1832 { 1833 int err; 1834 1835 err = register_pernet_device(&ip6_tnl_net_ops); 1836 if (err < 0) 1837 goto out_pernet; 1838 1839 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); 1840 if (err < 0) { 1841 pr_err("%s: can't register ip4ip6\n", __func__); 1842 goto out_ip4ip6; 1843 } 1844 1845 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); 1846 if (err < 0) { 1847 pr_err("%s: can't register ip6ip6\n", __func__); 1848 goto out_ip6ip6; 1849 } 1850 err = rtnl_link_register(&ip6_link_ops); 1851 if (err < 0) 1852 goto rtnl_link_failed; 1853 1854 return 0; 1855 1856 rtnl_link_failed: 1857 xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6); 1858 out_ip6ip6: 1859 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); 1860 out_ip4ip6: 1861 unregister_pernet_device(&ip6_tnl_net_ops); 1862 out_pernet: 1863 return err; 1864 } 1865 1866 /** 1867 * ip6_tunnel_cleanup - free resources and unregister protocol 1868 **/ 1869 1870 static void __exit ip6_tunnel_cleanup(void) 1871 { 1872 rtnl_link_unregister(&ip6_link_ops); 1873 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) 1874 pr_info("%s: can't deregister ip4ip6\n", __func__); 1875 1876 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1877 pr_info("%s: can't deregister ip6ip6\n", __func__); 1878 1879 unregister_pernet_device(&ip6_tnl_net_ops); 1880 } 1881 1882 module_init(ip6_tunnel_init); 1883 module_exit(ip6_tunnel_cleanup); 1884