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/ipv6.h> 51 #include <net/ip6_route.h> 52 #include <net/addrconf.h> 53 #include <net/ip6_tunnel.h> 54 #include <net/xfrm.h> 55 #include <net/dsfield.h> 56 #include <net/inet_ecn.h> 57 #include <net/net_namespace.h> 58 #include <net/netns/generic.h> 59 60 MODULE_AUTHOR("Ville Nuorvala"); 61 MODULE_DESCRIPTION("IPv6 tunneling device"); 62 MODULE_LICENSE("GPL"); 63 MODULE_ALIAS_NETDEV("ip6tnl0"); 64 65 #ifdef IP6_TNL_DEBUG 66 #define IP6_TNL_TRACE(x...) pr_debug("%s:" x "\n", __func__) 67 #else 68 #define IP6_TNL_TRACE(x...) do {;} while(0) 69 #endif 70 71 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 72 #define IPV6_TCLASS_SHIFT 20 73 74 #define HASH_SIZE_SHIFT 5 75 #define HASH_SIZE (1 << HASH_SIZE_SHIFT) 76 77 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 78 { 79 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 80 81 return hash_32(hash, HASH_SIZE_SHIFT); 82 } 83 84 static int ip6_tnl_dev_init(struct net_device *dev); 85 static void ip6_tnl_dev_setup(struct net_device *dev); 86 87 static int ip6_tnl_net_id __read_mostly; 88 struct ip6_tnl_net { 89 /* the IPv6 tunnel fallback device */ 90 struct net_device *fb_tnl_dev; 91 /* lists for storing tunnels in use */ 92 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE]; 93 struct ip6_tnl __rcu *tnls_wc[1]; 94 struct ip6_tnl __rcu **tnls[2]; 95 }; 96 97 /* often modified stats are per cpu, other are shared (netdev->stats) */ 98 struct pcpu_tstats { 99 unsigned long rx_packets; 100 unsigned long rx_bytes; 101 unsigned long tx_packets; 102 unsigned long tx_bytes; 103 } __attribute__((aligned(4*sizeof(unsigned long)))); 104 105 static struct net_device_stats *ip6_get_stats(struct net_device *dev) 106 { 107 struct pcpu_tstats sum = { 0 }; 108 int i; 109 110 for_each_possible_cpu(i) { 111 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 112 113 sum.rx_packets += tstats->rx_packets; 114 sum.rx_bytes += tstats->rx_bytes; 115 sum.tx_packets += tstats->tx_packets; 116 sum.tx_bytes += tstats->tx_bytes; 117 } 118 dev->stats.rx_packets = sum.rx_packets; 119 dev->stats.rx_bytes = sum.rx_bytes; 120 dev->stats.tx_packets = sum.tx_packets; 121 dev->stats.tx_bytes = sum.tx_bytes; 122 return &dev->stats; 123 } 124 125 /* 126 * Locking : hash tables are protected by RCU and RTNL 127 */ 128 129 struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 130 { 131 struct dst_entry *dst = t->dst_cache; 132 133 if (dst && dst->obsolete && 134 dst->ops->check(dst, t->dst_cookie) == NULL) { 135 t->dst_cache = NULL; 136 dst_release(dst); 137 return NULL; 138 } 139 140 return dst; 141 } 142 EXPORT_SYMBOL_GPL(ip6_tnl_dst_check); 143 144 void ip6_tnl_dst_reset(struct ip6_tnl *t) 145 { 146 dst_release(t->dst_cache); 147 t->dst_cache = NULL; 148 } 149 EXPORT_SYMBOL_GPL(ip6_tnl_dst_reset); 150 151 void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 152 { 153 struct rt6_info *rt = (struct rt6_info *) dst; 154 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 155 dst_release(t->dst_cache); 156 t->dst_cache = dst; 157 } 158 EXPORT_SYMBOL_GPL(ip6_tnl_dst_store); 159 160 /** 161 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses 162 * @remote: the address of the tunnel exit-point 163 * @local: the address of the tunnel entry-point 164 * 165 * Return: 166 * tunnel matching given end-points if found, 167 * else fallback tunnel if its device is up, 168 * else %NULL 169 **/ 170 171 #define for_each_ip6_tunnel_rcu(start) \ 172 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 173 174 static struct ip6_tnl * 175 ip6_tnl_lookup(struct net *net, const struct in6_addr *remote, const struct in6_addr *local) 176 { 177 unsigned int hash = HASH(remote, local); 178 struct ip6_tnl *t; 179 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 180 181 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 182 if (ipv6_addr_equal(local, &t->parms.laddr) && 183 ipv6_addr_equal(remote, &t->parms.raddr) && 184 (t->dev->flags & IFF_UP)) 185 return t; 186 } 187 t = rcu_dereference(ip6n->tnls_wc[0]); 188 if (t && (t->dev->flags & IFF_UP)) 189 return t; 190 191 return NULL; 192 } 193 194 /** 195 * ip6_tnl_bucket - get head of list matching given tunnel parameters 196 * @p: parameters containing tunnel end-points 197 * 198 * Description: 199 * ip6_tnl_bucket() returns the head of the list matching the 200 * &struct in6_addr entries laddr and raddr in @p. 201 * 202 * Return: head of IPv6 tunnel list 203 **/ 204 205 static struct ip6_tnl __rcu ** 206 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, const struct __ip6_tnl_parm *p) 207 { 208 const struct in6_addr *remote = &p->raddr; 209 const struct in6_addr *local = &p->laddr; 210 unsigned int h = 0; 211 int prio = 0; 212 213 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 214 prio = 1; 215 h = HASH(remote, local); 216 } 217 return &ip6n->tnls[prio][h]; 218 } 219 220 /** 221 * ip6_tnl_link - add tunnel to hash table 222 * @t: tunnel to be added 223 **/ 224 225 static void 226 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 227 { 228 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); 229 230 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 231 rcu_assign_pointer(*tp, t); 232 } 233 234 /** 235 * ip6_tnl_unlink - remove tunnel from hash table 236 * @t: tunnel to be removed 237 **/ 238 239 static void 240 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 241 { 242 struct ip6_tnl __rcu **tp; 243 struct ip6_tnl *iter; 244 245 for (tp = ip6_tnl_bucket(ip6n, &t->parms); 246 (iter = rtnl_dereference(*tp)) != NULL; 247 tp = &iter->next) { 248 if (t == iter) { 249 rcu_assign_pointer(*tp, t->next); 250 break; 251 } 252 } 253 } 254 255 static void ip6_dev_free(struct net_device *dev) 256 { 257 free_percpu(dev->tstats); 258 free_netdev(dev); 259 } 260 261 /** 262 * ip6_tnl_create - create a new tunnel 263 * @p: tunnel parameters 264 * @pt: pointer to new tunnel 265 * 266 * Description: 267 * Create tunnel matching given parameters. 268 * 269 * Return: 270 * created tunnel or NULL 271 **/ 272 273 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 274 { 275 struct net_device *dev; 276 struct ip6_tnl *t; 277 char name[IFNAMSIZ]; 278 int err; 279 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 280 281 if (p->name[0]) 282 strlcpy(name, p->name, IFNAMSIZ); 283 else 284 sprintf(name, "ip6tnl%%d"); 285 286 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); 287 if (dev == NULL) 288 goto failed; 289 290 dev_net_set(dev, net); 291 292 t = netdev_priv(dev); 293 t->parms = *p; 294 err = ip6_tnl_dev_init(dev); 295 if (err < 0) 296 goto failed_free; 297 298 if ((err = register_netdevice(dev)) < 0) 299 goto failed_free; 300 301 strcpy(t->parms.name, dev->name); 302 303 dev_hold(dev); 304 ip6_tnl_link(ip6n, t); 305 return t; 306 307 failed_free: 308 ip6_dev_free(dev); 309 failed: 310 return NULL; 311 } 312 313 /** 314 * ip6_tnl_locate - find or create tunnel matching given parameters 315 * @p: tunnel parameters 316 * @create: != 0 if allowed to create new tunnel if no match found 317 * 318 * Description: 319 * ip6_tnl_locate() first tries to locate an existing tunnel 320 * based on @parms. If this is unsuccessful, but @create is set a new 321 * tunnel device is created and registered for use. 322 * 323 * Return: 324 * matching tunnel or NULL 325 **/ 326 327 static struct ip6_tnl *ip6_tnl_locate(struct net *net, 328 struct __ip6_tnl_parm *p, int create) 329 { 330 const struct in6_addr *remote = &p->raddr; 331 const struct in6_addr *local = &p->laddr; 332 struct ip6_tnl __rcu **tp; 333 struct ip6_tnl *t; 334 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 335 336 for (tp = ip6_tnl_bucket(ip6n, p); 337 (t = rtnl_dereference(*tp)) != NULL; 338 tp = &t->next) { 339 if (ipv6_addr_equal(local, &t->parms.laddr) && 340 ipv6_addr_equal(remote, &t->parms.raddr)) 341 return t; 342 } 343 if (!create) 344 return NULL; 345 return ip6_tnl_create(net, p); 346 } 347 348 /** 349 * ip6_tnl_dev_uninit - tunnel device uninitializer 350 * @dev: the device to be destroyed 351 * 352 * Description: 353 * ip6_tnl_dev_uninit() removes tunnel from its list 354 **/ 355 356 static void 357 ip6_tnl_dev_uninit(struct net_device *dev) 358 { 359 struct ip6_tnl *t = netdev_priv(dev); 360 struct net *net = dev_net(dev); 361 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 362 363 if (dev == ip6n->fb_tnl_dev) 364 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 365 else 366 ip6_tnl_unlink(ip6n, t); 367 ip6_tnl_dst_reset(t); 368 dev_put(dev); 369 } 370 371 /** 372 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 373 * @skb: received socket buffer 374 * 375 * Return: 376 * 0 if none was found, 377 * else index to encapsulation limit 378 **/ 379 380 __u16 ip6_tnl_parse_tlv_enc_lim(struct sk_buff *skb, __u8 *raw) 381 { 382 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) raw; 383 __u8 nexthdr = ipv6h->nexthdr; 384 __u16 off = sizeof (*ipv6h); 385 386 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 387 __u16 optlen = 0; 388 struct ipv6_opt_hdr *hdr; 389 if (raw + off + sizeof (*hdr) > skb->data && 390 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 391 break; 392 393 hdr = (struct ipv6_opt_hdr *) (raw + off); 394 if (nexthdr == NEXTHDR_FRAGMENT) { 395 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 396 if (frag_hdr->frag_off) 397 break; 398 optlen = 8; 399 } else if (nexthdr == NEXTHDR_AUTH) { 400 optlen = (hdr->hdrlen + 2) << 2; 401 } else { 402 optlen = ipv6_optlen(hdr); 403 } 404 if (nexthdr == NEXTHDR_DEST) { 405 __u16 i = off + 2; 406 while (1) { 407 struct ipv6_tlv_tnl_enc_lim *tel; 408 409 /* No more room for encapsulation limit */ 410 if (i + sizeof (*tel) > off + optlen) 411 break; 412 413 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 414 /* return index of option if found and valid */ 415 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 416 tel->length == 1) 417 return i; 418 /* else jump to next option */ 419 if (tel->type) 420 i += tel->length + 2; 421 else 422 i++; 423 } 424 } 425 nexthdr = hdr->nexthdr; 426 off += optlen; 427 } 428 return 0; 429 } 430 EXPORT_SYMBOL(ip6_tnl_parse_tlv_enc_lim); 431 432 /** 433 * ip6_tnl_err - tunnel error handler 434 * 435 * Description: 436 * ip6_tnl_err() should handle errors in the tunnel according 437 * to the specifications in RFC 2473. 438 **/ 439 440 static int 441 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, 442 u8 *type, u8 *code, int *msg, __u32 *info, int offset) 443 { 444 const struct ipv6hdr *ipv6h = (const struct ipv6hdr *) skb->data; 445 struct ip6_tnl *t; 446 int rel_msg = 0; 447 u8 rel_type = ICMPV6_DEST_UNREACH; 448 u8 rel_code = ICMPV6_ADDR_UNREACH; 449 __u32 rel_info = 0; 450 __u16 len; 451 int err = -ENOENT; 452 453 /* If the packet doesn't contain the original IPv6 header we are 454 in trouble since we might need the source address for further 455 processing of the error. */ 456 457 rcu_read_lock(); 458 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, 459 &ipv6h->saddr)) == NULL) 460 goto out; 461 462 if (t->parms.proto != ipproto && t->parms.proto != 0) 463 goto out; 464 465 err = 0; 466 467 switch (*type) { 468 __u32 teli; 469 struct ipv6_tlv_tnl_enc_lim *tel; 470 __u32 mtu; 471 case ICMPV6_DEST_UNREACH: 472 net_warn_ratelimited("%s: Path to destination invalid or inactive!\n", 473 t->parms.name); 474 rel_msg = 1; 475 break; 476 case ICMPV6_TIME_EXCEED: 477 if ((*code) == ICMPV6_EXC_HOPLIMIT) { 478 net_warn_ratelimited("%s: Too small hop limit or routing loop in tunnel!\n", 479 t->parms.name); 480 rel_msg = 1; 481 } 482 break; 483 case ICMPV6_PARAMPROB: 484 teli = 0; 485 if ((*code) == ICMPV6_HDR_FIELD) 486 teli = ip6_tnl_parse_tlv_enc_lim(skb, skb->data); 487 488 if (teli && teli == *info - 2) { 489 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 490 if (tel->encap_limit == 0) { 491 net_warn_ratelimited("%s: Too small encapsulation limit or routing loop in tunnel!\n", 492 t->parms.name); 493 rel_msg = 1; 494 } 495 } else { 496 net_warn_ratelimited("%s: Recipient unable to parse tunneled packet!\n", 497 t->parms.name); 498 } 499 break; 500 case ICMPV6_PKT_TOOBIG: 501 mtu = *info - offset; 502 if (mtu < IPV6_MIN_MTU) 503 mtu = IPV6_MIN_MTU; 504 t->dev->mtu = mtu; 505 506 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 507 rel_type = ICMPV6_PKT_TOOBIG; 508 rel_code = 0; 509 rel_info = mtu; 510 rel_msg = 1; 511 } 512 break; 513 } 514 515 *type = rel_type; 516 *code = rel_code; 517 *info = rel_info; 518 *msg = rel_msg; 519 520 out: 521 rcu_read_unlock(); 522 return err; 523 } 524 525 static int 526 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 527 u8 type, u8 code, int offset, __be32 info) 528 { 529 int rel_msg = 0; 530 u8 rel_type = type; 531 u8 rel_code = code; 532 __u32 rel_info = ntohl(info); 533 int err; 534 struct sk_buff *skb2; 535 const struct iphdr *eiph; 536 struct rtable *rt; 537 struct flowi4 fl4; 538 539 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, 540 &rel_msg, &rel_info, offset); 541 if (err < 0) 542 return err; 543 544 if (rel_msg == 0) 545 return 0; 546 547 switch (rel_type) { 548 case ICMPV6_DEST_UNREACH: 549 if (rel_code != ICMPV6_ADDR_UNREACH) 550 return 0; 551 rel_type = ICMP_DEST_UNREACH; 552 rel_code = ICMP_HOST_UNREACH; 553 break; 554 case ICMPV6_PKT_TOOBIG: 555 if (rel_code != 0) 556 return 0; 557 rel_type = ICMP_DEST_UNREACH; 558 rel_code = ICMP_FRAG_NEEDED; 559 break; 560 case NDISC_REDIRECT: 561 rel_type = ICMP_REDIRECT; 562 rel_code = ICMP_REDIR_HOST; 563 default: 564 return 0; 565 } 566 567 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) 568 return 0; 569 570 skb2 = skb_clone(skb, GFP_ATOMIC); 571 if (!skb2) 572 return 0; 573 574 skb_dst_drop(skb2); 575 576 skb_pull(skb2, offset); 577 skb_reset_network_header(skb2); 578 eiph = ip_hdr(skb2); 579 580 /* Try to guess incoming interface */ 581 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 582 eiph->saddr, 0, 583 0, 0, 584 IPPROTO_IPIP, RT_TOS(eiph->tos), 0); 585 if (IS_ERR(rt)) 586 goto out; 587 588 skb2->dev = rt->dst.dev; 589 590 /* route "incoming" packet */ 591 if (rt->rt_flags & RTCF_LOCAL) { 592 ip_rt_put(rt); 593 rt = NULL; 594 rt = ip_route_output_ports(dev_net(skb->dev), &fl4, NULL, 595 eiph->daddr, eiph->saddr, 596 0, 0, 597 IPPROTO_IPIP, 598 RT_TOS(eiph->tos), 0); 599 if (IS_ERR(rt) || 600 rt->dst.dev->type != ARPHRD_TUNNEL) { 601 if (!IS_ERR(rt)) 602 ip_rt_put(rt); 603 goto out; 604 } 605 skb_dst_set(skb2, &rt->dst); 606 } else { 607 ip_rt_put(rt); 608 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, 609 skb2->dev) || 610 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) 611 goto out; 612 } 613 614 /* change mtu on this route */ 615 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { 616 if (rel_info > dst_mtu(skb_dst(skb2))) 617 goto out; 618 619 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), NULL, skb2, rel_info); 620 } 621 if (rel_type == ICMP_REDIRECT) 622 skb_dst(skb2)->ops->redirect(skb_dst(skb2), NULL, skb2); 623 624 icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); 625 626 out: 627 kfree_skb(skb2); 628 return 0; 629 } 630 631 static int 632 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 633 u8 type, u8 code, int offset, __be32 info) 634 { 635 int rel_msg = 0; 636 u8 rel_type = type; 637 u8 rel_code = code; 638 __u32 rel_info = ntohl(info); 639 int err; 640 641 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, 642 &rel_msg, &rel_info, offset); 643 if (err < 0) 644 return err; 645 646 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { 647 struct rt6_info *rt; 648 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 649 650 if (!skb2) 651 return 0; 652 653 skb_dst_drop(skb2); 654 skb_pull(skb2, offset); 655 skb_reset_network_header(skb2); 656 657 /* Try to guess incoming interface */ 658 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, 659 NULL, 0, 0); 660 661 if (rt && rt->dst.dev) 662 skb2->dev = rt->dst.dev; 663 664 icmpv6_send(skb2, rel_type, rel_code, rel_info); 665 666 if (rt) 667 dst_release(&rt->dst); 668 669 kfree_skb(skb2); 670 } 671 672 return 0; 673 } 674 675 static void ip4ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 676 const struct ipv6hdr *ipv6h, 677 struct sk_buff *skb) 678 { 679 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; 680 681 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 682 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); 683 684 if (INET_ECN_is_ce(dsfield)) 685 IP_ECN_set_ce(ip_hdr(skb)); 686 } 687 688 static void ip6ip6_dscp_ecn_decapsulate(const struct ip6_tnl *t, 689 const struct ipv6hdr *ipv6h, 690 struct sk_buff *skb) 691 { 692 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 693 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); 694 695 if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h))) 696 IP6_ECN_set_ce(ipv6_hdr(skb)); 697 } 698 699 __u32 ip6_tnl_get_cap(struct ip6_tnl *t, 700 const struct in6_addr *laddr, 701 const struct in6_addr *raddr) 702 { 703 struct __ip6_tnl_parm *p = &t->parms; 704 int ltype = ipv6_addr_type(laddr); 705 int rtype = ipv6_addr_type(raddr); 706 __u32 flags = 0; 707 708 if (ltype == IPV6_ADDR_ANY || rtype == IPV6_ADDR_ANY) { 709 flags = IP6_TNL_F_CAP_PER_PACKET; 710 } else if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 711 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 712 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 713 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 714 if (ltype&IPV6_ADDR_UNICAST) 715 flags |= IP6_TNL_F_CAP_XMIT; 716 if (rtype&IPV6_ADDR_UNICAST) 717 flags |= IP6_TNL_F_CAP_RCV; 718 } 719 return flags; 720 } 721 EXPORT_SYMBOL(ip6_tnl_get_cap); 722 723 /* called with rcu_read_lock() */ 724 int ip6_tnl_rcv_ctl(struct ip6_tnl *t, 725 const struct in6_addr *laddr, 726 const struct in6_addr *raddr) 727 { 728 struct __ip6_tnl_parm *p = &t->parms; 729 int ret = 0; 730 struct net *net = dev_net(t->dev); 731 732 if ((p->flags & IP6_TNL_F_CAP_RCV) || 733 ((p->flags & IP6_TNL_F_CAP_PER_PACKET) && 734 (ip6_tnl_get_cap(t, laddr, raddr) & IP6_TNL_F_CAP_RCV))) { 735 struct net_device *ldev = NULL; 736 737 if (p->link) 738 ldev = dev_get_by_index_rcu(net, p->link); 739 740 if ((ipv6_addr_is_multicast(laddr) || 741 likely(ipv6_chk_addr(net, laddr, ldev, 0))) && 742 likely(!ipv6_chk_addr(net, raddr, NULL, 0))) 743 ret = 1; 744 } 745 return ret; 746 } 747 EXPORT_SYMBOL_GPL(ip6_tnl_rcv_ctl); 748 749 /** 750 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally 751 * @skb: received socket buffer 752 * @protocol: ethernet protocol ID 753 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN 754 * 755 * Return: 0 756 **/ 757 758 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, 759 __u8 ipproto, 760 void (*dscp_ecn_decapsulate)(const struct ip6_tnl *t, 761 const struct ipv6hdr *ipv6h, 762 struct sk_buff *skb)) 763 { 764 struct ip6_tnl *t; 765 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 766 767 rcu_read_lock(); 768 769 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, 770 &ipv6h->daddr)) != NULL) { 771 struct pcpu_tstats *tstats; 772 773 if (t->parms.proto != ipproto && t->parms.proto != 0) { 774 rcu_read_unlock(); 775 goto discard; 776 } 777 778 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 779 rcu_read_unlock(); 780 goto discard; 781 } 782 783 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 784 t->dev->stats.rx_dropped++; 785 rcu_read_unlock(); 786 goto discard; 787 } 788 secpath_reset(skb); 789 skb->mac_header = skb->network_header; 790 skb_reset_network_header(skb); 791 skb->protocol = htons(protocol); 792 skb->pkt_type = PACKET_HOST; 793 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 794 795 tstats = this_cpu_ptr(t->dev->tstats); 796 tstats->rx_packets++; 797 tstats->rx_bytes += skb->len; 798 799 __skb_tunnel_rx(skb, t->dev); 800 801 dscp_ecn_decapsulate(t, ipv6h, skb); 802 803 netif_rx(skb); 804 805 rcu_read_unlock(); 806 return 0; 807 } 808 rcu_read_unlock(); 809 return 1; 810 811 discard: 812 kfree_skb(skb); 813 return 0; 814 } 815 816 static int ip4ip6_rcv(struct sk_buff *skb) 817 { 818 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, 819 ip4ip6_dscp_ecn_decapsulate); 820 } 821 822 static int ip6ip6_rcv(struct sk_buff *skb) 823 { 824 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, 825 ip6ip6_dscp_ecn_decapsulate); 826 } 827 828 struct ipv6_tel_txoption { 829 struct ipv6_txoptions ops; 830 __u8 dst_opt[8]; 831 }; 832 833 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 834 { 835 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 836 837 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 838 opt->dst_opt[3] = 1; 839 opt->dst_opt[4] = encap_limit; 840 opt->dst_opt[5] = IPV6_TLV_PADN; 841 opt->dst_opt[6] = 1; 842 843 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 844 opt->ops.opt_nflen = 8; 845 } 846 847 /** 848 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 849 * @t: the outgoing tunnel device 850 * @hdr: IPv6 header from the incoming packet 851 * 852 * Description: 853 * Avoid trivial tunneling loop by checking that tunnel exit-point 854 * doesn't match source of incoming packet. 855 * 856 * Return: 857 * 1 if conflict, 858 * 0 else 859 **/ 860 861 static inline bool 862 ip6_tnl_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 863 { 864 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 865 } 866 867 int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 868 { 869 struct __ip6_tnl_parm *p = &t->parms; 870 int ret = 0; 871 struct net *net = dev_net(t->dev); 872 873 if (p->flags & IP6_TNL_F_CAP_XMIT) { 874 struct net_device *ldev = NULL; 875 876 rcu_read_lock(); 877 if (p->link) 878 ldev = dev_get_by_index_rcu(net, p->link); 879 880 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) 881 pr_warn("%s xmit: Local address not yet configured!\n", 882 p->name); 883 else if (!ipv6_addr_is_multicast(&p->raddr) && 884 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) 885 pr_warn("%s xmit: Routing loop! Remote address found on this node!\n", 886 p->name); 887 else 888 ret = 1; 889 rcu_read_unlock(); 890 } 891 return ret; 892 } 893 EXPORT_SYMBOL_GPL(ip6_tnl_xmit_ctl); 894 895 /** 896 * ip6_tnl_xmit2 - encapsulate packet and send 897 * @skb: the outgoing socket buffer 898 * @dev: the outgoing tunnel device 899 * @dsfield: dscp code for outer header 900 * @fl: flow of tunneled packet 901 * @encap_limit: encapsulation limit 902 * @pmtu: Path MTU is stored if packet is too big 903 * 904 * Description: 905 * Build new header and do some sanity checks on the packet before sending 906 * it. 907 * 908 * Return: 909 * 0 on success 910 * -1 fail 911 * %-EMSGSIZE message too big. return mtu in this case. 912 **/ 913 914 static int ip6_tnl_xmit2(struct sk_buff *skb, 915 struct net_device *dev, 916 __u8 dsfield, 917 struct flowi6 *fl6, 918 int encap_limit, 919 __u32 *pmtu) 920 { 921 struct net *net = dev_net(dev); 922 struct ip6_tnl *t = netdev_priv(dev); 923 struct net_device_stats *stats = &t->dev->stats; 924 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 925 struct ipv6_tel_txoption opt; 926 struct dst_entry *dst = NULL, *ndst = NULL; 927 struct net_device *tdev; 928 int mtu; 929 unsigned int max_headroom = sizeof(struct ipv6hdr); 930 u8 proto; 931 int err = -1; 932 int pkt_len; 933 934 if (!fl6->flowi6_mark) 935 dst = ip6_tnl_dst_check(t); 936 if (!dst) { 937 ndst = ip6_route_output(net, NULL, fl6); 938 939 if (ndst->error) 940 goto tx_err_link_failure; 941 ndst = xfrm_lookup(net, ndst, flowi6_to_flowi(fl6), NULL, 0); 942 if (IS_ERR(ndst)) { 943 err = PTR_ERR(ndst); 944 ndst = NULL; 945 goto tx_err_link_failure; 946 } 947 dst = ndst; 948 } 949 950 tdev = dst->dev; 951 952 if (tdev == dev) { 953 stats->collisions++; 954 net_warn_ratelimited("%s: Local routing loop detected!\n", 955 t->parms.name); 956 goto tx_err_dst_release; 957 } 958 mtu = dst_mtu(dst) - sizeof (*ipv6h); 959 if (encap_limit >= 0) { 960 max_headroom += 8; 961 mtu -= 8; 962 } 963 if (mtu < IPV6_MIN_MTU) 964 mtu = IPV6_MIN_MTU; 965 if (skb_dst(skb)) 966 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu); 967 if (skb->len > mtu) { 968 *pmtu = mtu; 969 err = -EMSGSIZE; 970 goto tx_err_dst_release; 971 } 972 973 /* 974 * Okay, now see if we can stuff it in the buffer as-is. 975 */ 976 max_headroom += LL_RESERVED_SPACE(tdev); 977 978 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 979 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 980 struct sk_buff *new_skb; 981 982 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 983 goto tx_err_dst_release; 984 985 if (skb->sk) 986 skb_set_owner_w(new_skb, skb->sk); 987 consume_skb(skb); 988 skb = new_skb; 989 } 990 skb_dst_drop(skb); 991 if (fl6->flowi6_mark) { 992 skb_dst_set(skb, dst); 993 ndst = NULL; 994 } else { 995 skb_dst_set_noref(skb, dst); 996 } 997 skb->transport_header = skb->network_header; 998 999 proto = fl6->flowi6_proto; 1000 if (encap_limit >= 0) { 1001 init_tel_txopt(&opt, encap_limit); 1002 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 1003 } 1004 skb_push(skb, sizeof(struct ipv6hdr)); 1005 skb_reset_network_header(skb); 1006 ipv6h = ipv6_hdr(skb); 1007 *(__be32*)ipv6h = fl6->flowlabel | htonl(0x60000000); 1008 dsfield = INET_ECN_encapsulate(0, dsfield); 1009 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 1010 ipv6h->hop_limit = t->parms.hop_limit; 1011 ipv6h->nexthdr = proto; 1012 ipv6h->saddr = fl6->saddr; 1013 ipv6h->daddr = fl6->daddr; 1014 nf_reset(skb); 1015 pkt_len = skb->len; 1016 err = ip6_local_out(skb); 1017 1018 if (net_xmit_eval(err) == 0) { 1019 struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats); 1020 1021 tstats->tx_bytes += pkt_len; 1022 tstats->tx_packets++; 1023 } else { 1024 stats->tx_errors++; 1025 stats->tx_aborted_errors++; 1026 } 1027 if (ndst) 1028 ip6_tnl_dst_store(t, ndst); 1029 return 0; 1030 tx_err_link_failure: 1031 stats->tx_carrier_errors++; 1032 dst_link_failure(skb); 1033 tx_err_dst_release: 1034 dst_release(ndst); 1035 return err; 1036 } 1037 1038 static inline int 1039 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1040 { 1041 struct ip6_tnl *t = netdev_priv(dev); 1042 const struct iphdr *iph = ip_hdr(skb); 1043 int encap_limit = -1; 1044 struct flowi6 fl6; 1045 __u8 dsfield; 1046 __u32 mtu; 1047 int err; 1048 1049 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || 1050 !ip6_tnl_xmit_ctl(t)) 1051 return -1; 1052 1053 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1054 encap_limit = t->parms.encap_limit; 1055 1056 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6)); 1057 fl6.flowi6_proto = IPPROTO_IPIP; 1058 1059 dsfield = ipv4_get_dsfield(iph); 1060 1061 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1062 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) 1063 & IPV6_TCLASS_MASK; 1064 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1065 fl6.flowi6_mark = skb->mark; 1066 1067 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1068 if (err != 0) { 1069 /* XXX: send ICMP error even if DF is not set. */ 1070 if (err == -EMSGSIZE) 1071 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 1072 htonl(mtu)); 1073 return -1; 1074 } 1075 1076 return 0; 1077 } 1078 1079 static inline int 1080 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1081 { 1082 struct ip6_tnl *t = netdev_priv(dev); 1083 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1084 int encap_limit = -1; 1085 __u16 offset; 1086 struct flowi6 fl6; 1087 __u8 dsfield; 1088 __u32 mtu; 1089 int err; 1090 1091 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 1092 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) 1093 return -1; 1094 1095 offset = ip6_tnl_parse_tlv_enc_lim(skb, skb_network_header(skb)); 1096 if (offset > 0) { 1097 struct ipv6_tlv_tnl_enc_lim *tel; 1098 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; 1099 if (tel->encap_limit == 0) { 1100 icmpv6_send(skb, ICMPV6_PARAMPROB, 1101 ICMPV6_HDR_FIELD, offset + 2); 1102 return -1; 1103 } 1104 encap_limit = tel->encap_limit - 1; 1105 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1106 encap_limit = t->parms.encap_limit; 1107 1108 memcpy(&fl6, &t->fl.u.ip6, sizeof (fl6)); 1109 fl6.flowi6_proto = IPPROTO_IPV6; 1110 1111 dsfield = ipv6_get_dsfield(ipv6h); 1112 if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS) 1113 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 1114 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL) 1115 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); 1116 if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK) 1117 fl6.flowi6_mark = skb->mark; 1118 1119 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu); 1120 if (err != 0) { 1121 if (err == -EMSGSIZE) 1122 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1123 return -1; 1124 } 1125 1126 return 0; 1127 } 1128 1129 static netdev_tx_t 1130 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1131 { 1132 struct ip6_tnl *t = netdev_priv(dev); 1133 struct net_device_stats *stats = &t->dev->stats; 1134 int ret; 1135 1136 switch (skb->protocol) { 1137 case htons(ETH_P_IP): 1138 ret = ip4ip6_tnl_xmit(skb, dev); 1139 break; 1140 case htons(ETH_P_IPV6): 1141 ret = ip6ip6_tnl_xmit(skb, dev); 1142 break; 1143 default: 1144 goto tx_err; 1145 } 1146 1147 if (ret < 0) 1148 goto tx_err; 1149 1150 return NETDEV_TX_OK; 1151 1152 tx_err: 1153 stats->tx_errors++; 1154 stats->tx_dropped++; 1155 kfree_skb(skb); 1156 return NETDEV_TX_OK; 1157 } 1158 1159 static void ip6_tnl_link_config(struct ip6_tnl *t) 1160 { 1161 struct net_device *dev = t->dev; 1162 struct __ip6_tnl_parm *p = &t->parms; 1163 struct flowi6 *fl6 = &t->fl.u.ip6; 1164 1165 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 1166 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 1167 1168 /* Set up flowi template */ 1169 fl6->saddr = p->laddr; 1170 fl6->daddr = p->raddr; 1171 fl6->flowi6_oif = p->link; 1172 fl6->flowlabel = 0; 1173 1174 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 1175 fl6->flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 1176 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1177 fl6->flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 1178 1179 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV|IP6_TNL_F_CAP_PER_PACKET); 1180 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 1181 1182 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 1183 dev->flags |= IFF_POINTOPOINT; 1184 else 1185 dev->flags &= ~IFF_POINTOPOINT; 1186 1187 dev->iflink = p->link; 1188 1189 if (p->flags & IP6_TNL_F_CAP_XMIT) { 1190 int strict = (ipv6_addr_type(&p->raddr) & 1191 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 1192 1193 struct rt6_info *rt = rt6_lookup(dev_net(dev), 1194 &p->raddr, &p->laddr, 1195 p->link, strict); 1196 1197 if (rt == NULL) 1198 return; 1199 1200 if (rt->dst.dev) { 1201 dev->hard_header_len = rt->dst.dev->hard_header_len + 1202 sizeof (struct ipv6hdr); 1203 1204 dev->mtu = rt->dst.dev->mtu - sizeof (struct ipv6hdr); 1205 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1206 dev->mtu-=8; 1207 1208 if (dev->mtu < IPV6_MIN_MTU) 1209 dev->mtu = IPV6_MIN_MTU; 1210 } 1211 dst_release(&rt->dst); 1212 } 1213 } 1214 1215 /** 1216 * ip6_tnl_change - update the tunnel parameters 1217 * @t: tunnel to be changed 1218 * @p: tunnel configuration parameters 1219 * 1220 * Description: 1221 * ip6_tnl_change() updates the tunnel parameters 1222 **/ 1223 1224 static int 1225 ip6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p) 1226 { 1227 t->parms.laddr = p->laddr; 1228 t->parms.raddr = p->raddr; 1229 t->parms.flags = p->flags; 1230 t->parms.hop_limit = p->hop_limit; 1231 t->parms.encap_limit = p->encap_limit; 1232 t->parms.flowinfo = p->flowinfo; 1233 t->parms.link = p->link; 1234 t->parms.proto = p->proto; 1235 ip6_tnl_dst_reset(t); 1236 ip6_tnl_link_config(t); 1237 return 0; 1238 } 1239 1240 static void 1241 ip6_tnl_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm *u) 1242 { 1243 p->laddr = u->laddr; 1244 p->raddr = u->raddr; 1245 p->flags = u->flags; 1246 p->hop_limit = u->hop_limit; 1247 p->encap_limit = u->encap_limit; 1248 p->flowinfo = u->flowinfo; 1249 p->link = u->link; 1250 p->proto = u->proto; 1251 memcpy(p->name, u->name, sizeof(u->name)); 1252 } 1253 1254 static void 1255 ip6_tnl_parm_to_user(struct ip6_tnl_parm *u, const struct __ip6_tnl_parm *p) 1256 { 1257 u->laddr = p->laddr; 1258 u->raddr = p->raddr; 1259 u->flags = p->flags; 1260 u->hop_limit = p->hop_limit; 1261 u->encap_limit = p->encap_limit; 1262 u->flowinfo = p->flowinfo; 1263 u->link = p->link; 1264 u->proto = p->proto; 1265 memcpy(u->name, p->name, sizeof(u->name)); 1266 } 1267 1268 /** 1269 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace 1270 * @dev: virtual device associated with tunnel 1271 * @ifr: parameters passed from userspace 1272 * @cmd: command to be performed 1273 * 1274 * Description: 1275 * ip6_tnl_ioctl() is used for managing IPv6 tunnels 1276 * from userspace. 1277 * 1278 * The possible commands are the following: 1279 * %SIOCGETTUNNEL: get tunnel parameters for device 1280 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 1281 * %SIOCCHGTUNNEL: change tunnel parameters to those given 1282 * %SIOCDELTUNNEL: delete tunnel 1283 * 1284 * The fallback device "ip6tnl0", created during module 1285 * initialization, can be used for creating other tunnel devices. 1286 * 1287 * Return: 1288 * 0 on success, 1289 * %-EFAULT if unable to copy data to or from userspace, 1290 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 1291 * %-EINVAL if passed tunnel parameters are invalid, 1292 * %-EEXIST if changing a tunnel's parameters would cause a conflict 1293 * %-ENODEV if attempting to change or delete a nonexisting device 1294 **/ 1295 1296 static int 1297 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1298 { 1299 int err = 0; 1300 struct ip6_tnl_parm p; 1301 struct __ip6_tnl_parm p1; 1302 struct ip6_tnl *t = NULL; 1303 struct net *net = dev_net(dev); 1304 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1305 1306 switch (cmd) { 1307 case SIOCGETTUNNEL: 1308 if (dev == ip6n->fb_tnl_dev) { 1309 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 1310 err = -EFAULT; 1311 break; 1312 } 1313 ip6_tnl_parm_from_user(&p1, &p); 1314 t = ip6_tnl_locate(net, &p1, 0); 1315 } else { 1316 memset(&p, 0, sizeof(p)); 1317 } 1318 if (t == NULL) 1319 t = netdev_priv(dev); 1320 ip6_tnl_parm_to_user(&p, &t->parms); 1321 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 1322 err = -EFAULT; 1323 } 1324 break; 1325 case SIOCADDTUNNEL: 1326 case SIOCCHGTUNNEL: 1327 err = -EPERM; 1328 if (!capable(CAP_NET_ADMIN)) 1329 break; 1330 err = -EFAULT; 1331 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1332 break; 1333 err = -EINVAL; 1334 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && 1335 p.proto != 0) 1336 break; 1337 ip6_tnl_parm_from_user(&p1, &p); 1338 t = ip6_tnl_locate(net, &p1, cmd == SIOCADDTUNNEL); 1339 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 1340 if (t != NULL) { 1341 if (t->dev != dev) { 1342 err = -EEXIST; 1343 break; 1344 } 1345 } else 1346 t = netdev_priv(dev); 1347 1348 ip6_tnl_unlink(ip6n, t); 1349 synchronize_net(); 1350 err = ip6_tnl_change(t, &p1); 1351 ip6_tnl_link(ip6n, t); 1352 netdev_state_change(dev); 1353 } 1354 if (t) { 1355 err = 0; 1356 ip6_tnl_parm_to_user(&p, &t->parms); 1357 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 1358 err = -EFAULT; 1359 1360 } else 1361 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1362 break; 1363 case SIOCDELTUNNEL: 1364 err = -EPERM; 1365 if (!capable(CAP_NET_ADMIN)) 1366 break; 1367 1368 if (dev == ip6n->fb_tnl_dev) { 1369 err = -EFAULT; 1370 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1371 break; 1372 err = -ENOENT; 1373 ip6_tnl_parm_from_user(&p1, &p); 1374 t = ip6_tnl_locate(net, &p1, 0); 1375 if (t == NULL) 1376 break; 1377 err = -EPERM; 1378 if (t->dev == ip6n->fb_tnl_dev) 1379 break; 1380 dev = t->dev; 1381 } 1382 err = 0; 1383 unregister_netdevice(dev); 1384 break; 1385 default: 1386 err = -EINVAL; 1387 } 1388 return err; 1389 } 1390 1391 /** 1392 * ip6_tnl_change_mtu - change mtu manually for tunnel device 1393 * @dev: virtual device associated with tunnel 1394 * @new_mtu: the new mtu 1395 * 1396 * Return: 1397 * 0 on success, 1398 * %-EINVAL if mtu too small 1399 **/ 1400 1401 static int 1402 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1403 { 1404 if (new_mtu < IPV6_MIN_MTU) { 1405 return -EINVAL; 1406 } 1407 dev->mtu = new_mtu; 1408 return 0; 1409 } 1410 1411 1412 static const struct net_device_ops ip6_tnl_netdev_ops = { 1413 .ndo_uninit = ip6_tnl_dev_uninit, 1414 .ndo_start_xmit = ip6_tnl_xmit, 1415 .ndo_do_ioctl = ip6_tnl_ioctl, 1416 .ndo_change_mtu = ip6_tnl_change_mtu, 1417 .ndo_get_stats = ip6_get_stats, 1418 }; 1419 1420 1421 /** 1422 * ip6_tnl_dev_setup - setup virtual tunnel device 1423 * @dev: virtual device associated with tunnel 1424 * 1425 * Description: 1426 * Initialize function pointers and device parameters 1427 **/ 1428 1429 static void ip6_tnl_dev_setup(struct net_device *dev) 1430 { 1431 struct ip6_tnl *t; 1432 1433 dev->netdev_ops = &ip6_tnl_netdev_ops; 1434 dev->destructor = ip6_dev_free; 1435 1436 dev->type = ARPHRD_TUNNEL6; 1437 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1438 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1439 t = netdev_priv(dev); 1440 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1441 dev->mtu-=8; 1442 dev->flags |= IFF_NOARP; 1443 dev->addr_len = sizeof(struct in6_addr); 1444 dev->features |= NETIF_F_NETNS_LOCAL; 1445 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1446 } 1447 1448 1449 /** 1450 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1451 * @dev: virtual device associated with tunnel 1452 **/ 1453 1454 static inline int 1455 ip6_tnl_dev_init_gen(struct net_device *dev) 1456 { 1457 struct ip6_tnl *t = netdev_priv(dev); 1458 1459 t->dev = dev; 1460 dev->tstats = alloc_percpu(struct pcpu_tstats); 1461 if (!dev->tstats) 1462 return -ENOMEM; 1463 return 0; 1464 } 1465 1466 /** 1467 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1468 * @dev: virtual device associated with tunnel 1469 **/ 1470 1471 static int ip6_tnl_dev_init(struct net_device *dev) 1472 { 1473 struct ip6_tnl *t = netdev_priv(dev); 1474 int err = ip6_tnl_dev_init_gen(dev); 1475 1476 if (err) 1477 return err; 1478 ip6_tnl_link_config(t); 1479 return 0; 1480 } 1481 1482 /** 1483 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1484 * @dev: fallback device 1485 * 1486 * Return: 0 1487 **/ 1488 1489 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev) 1490 { 1491 struct ip6_tnl *t = netdev_priv(dev); 1492 struct net *net = dev_net(dev); 1493 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1494 int err = ip6_tnl_dev_init_gen(dev); 1495 1496 if (err) 1497 return err; 1498 1499 t->parms.proto = IPPROTO_IPV6; 1500 dev_hold(dev); 1501 1502 ip6_tnl_link_config(t); 1503 1504 rcu_assign_pointer(ip6n->tnls_wc[0], t); 1505 return 0; 1506 } 1507 1508 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { 1509 .handler = ip4ip6_rcv, 1510 .err_handler = ip4ip6_err, 1511 .priority = 1, 1512 }; 1513 1514 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { 1515 .handler = ip6ip6_rcv, 1516 .err_handler = ip6ip6_err, 1517 .priority = 1, 1518 }; 1519 1520 static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) 1521 { 1522 int h; 1523 struct ip6_tnl *t; 1524 LIST_HEAD(list); 1525 1526 for (h = 0; h < HASH_SIZE; h++) { 1527 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1528 while (t != NULL) { 1529 unregister_netdevice_queue(t->dev, &list); 1530 t = rtnl_dereference(t->next); 1531 } 1532 } 1533 1534 t = rtnl_dereference(ip6n->tnls_wc[0]); 1535 unregister_netdevice_queue(t->dev, &list); 1536 unregister_netdevice_many(&list); 1537 } 1538 1539 static int __net_init ip6_tnl_init_net(struct net *net) 1540 { 1541 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1542 struct ip6_tnl *t = NULL; 1543 int err; 1544 1545 ip6n->tnls[0] = ip6n->tnls_wc; 1546 ip6n->tnls[1] = ip6n->tnls_r_l; 1547 1548 err = -ENOMEM; 1549 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1550 ip6_tnl_dev_setup); 1551 1552 if (!ip6n->fb_tnl_dev) 1553 goto err_alloc_dev; 1554 dev_net_set(ip6n->fb_tnl_dev, net); 1555 1556 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1557 if (err < 0) 1558 goto err_register; 1559 1560 err = register_netdev(ip6n->fb_tnl_dev); 1561 if (err < 0) 1562 goto err_register; 1563 1564 t = netdev_priv(ip6n->fb_tnl_dev); 1565 1566 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1567 return 0; 1568 1569 err_register: 1570 ip6_dev_free(ip6n->fb_tnl_dev); 1571 err_alloc_dev: 1572 return err; 1573 } 1574 1575 static void __net_exit ip6_tnl_exit_net(struct net *net) 1576 { 1577 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1578 1579 rtnl_lock(); 1580 ip6_tnl_destroy_tunnels(ip6n); 1581 rtnl_unlock(); 1582 } 1583 1584 static struct pernet_operations ip6_tnl_net_ops = { 1585 .init = ip6_tnl_init_net, 1586 .exit = ip6_tnl_exit_net, 1587 .id = &ip6_tnl_net_id, 1588 .size = sizeof(struct ip6_tnl_net), 1589 }; 1590 1591 /** 1592 * ip6_tunnel_init - register protocol and reserve needed resources 1593 * 1594 * Return: 0 on success 1595 **/ 1596 1597 static int __init ip6_tunnel_init(void) 1598 { 1599 int err; 1600 1601 err = register_pernet_device(&ip6_tnl_net_ops); 1602 if (err < 0) 1603 goto out_pernet; 1604 1605 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); 1606 if (err < 0) { 1607 pr_err("%s: can't register ip4ip6\n", __func__); 1608 goto out_ip4ip6; 1609 } 1610 1611 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); 1612 if (err < 0) { 1613 pr_err("%s: can't register ip6ip6\n", __func__); 1614 goto out_ip6ip6; 1615 } 1616 1617 return 0; 1618 1619 out_ip6ip6: 1620 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); 1621 out_ip4ip6: 1622 unregister_pernet_device(&ip6_tnl_net_ops); 1623 out_pernet: 1624 return err; 1625 } 1626 1627 /** 1628 * ip6_tunnel_cleanup - free resources and unregister protocol 1629 **/ 1630 1631 static void __exit ip6_tunnel_cleanup(void) 1632 { 1633 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) 1634 pr_info("%s: can't deregister ip4ip6\n", __func__); 1635 1636 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1637 pr_info("%s: can't deregister ip6ip6\n", __func__); 1638 1639 unregister_pernet_device(&ip6_tnl_net_ops); 1640 } 1641 1642 module_init(ip6_tunnel_init); 1643 module_exit(ip6_tunnel_cleanup); 1644