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 #include <linux/module.h> 22 #include <linux/capability.h> 23 #include <linux/errno.h> 24 #include <linux/types.h> 25 #include <linux/sockios.h> 26 #include <linux/icmp.h> 27 #include <linux/if.h> 28 #include <linux/in.h> 29 #include <linux/ip.h> 30 #include <linux/if_tunnel.h> 31 #include <linux/net.h> 32 #include <linux/in6.h> 33 #include <linux/netdevice.h> 34 #include <linux/if_arp.h> 35 #include <linux/icmpv6.h> 36 #include <linux/init.h> 37 #include <linux/route.h> 38 #include <linux/rtnetlink.h> 39 #include <linux/netfilter_ipv6.h> 40 #include <linux/slab.h> 41 42 #include <asm/uaccess.h> 43 #include <asm/atomic.h> 44 45 #include <net/icmp.h> 46 #include <net/ip.h> 47 #include <net/ipv6.h> 48 #include <net/ip6_route.h> 49 #include <net/addrconf.h> 50 #include <net/ip6_tunnel.h> 51 #include <net/xfrm.h> 52 #include <net/dsfield.h> 53 #include <net/inet_ecn.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 57 MODULE_AUTHOR("Ville Nuorvala"); 58 MODULE_DESCRIPTION("IPv6 tunneling device"); 59 MODULE_LICENSE("GPL"); 60 61 #ifdef IP6_TNL_DEBUG 62 #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __func__) 63 #else 64 #define IP6_TNL_TRACE(x...) do {;} while(0) 65 #endif 66 67 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 68 #define IPV6_TCLASS_SHIFT 20 69 70 #define HASH_SIZE 32 71 72 #define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ 73 (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ 74 (HASH_SIZE - 1)) 75 76 static int ip6_tnl_dev_init(struct net_device *dev); 77 static void ip6_tnl_dev_setup(struct net_device *dev); 78 79 static int ip6_tnl_net_id __read_mostly; 80 struct ip6_tnl_net { 81 /* the IPv6 tunnel fallback device */ 82 struct net_device *fb_tnl_dev; 83 /* lists for storing tunnels in use */ 84 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE]; 85 struct ip6_tnl __rcu *tnls_wc[1]; 86 struct ip6_tnl __rcu **tnls[2]; 87 }; 88 89 /* often modified stats are per cpu, other are shared (netdev->stats) */ 90 struct pcpu_tstats { 91 unsigned long rx_packets; 92 unsigned long rx_bytes; 93 unsigned long tx_packets; 94 unsigned long tx_bytes; 95 }; 96 97 static struct net_device_stats *ip6_get_stats(struct net_device *dev) 98 { 99 struct pcpu_tstats sum = { 0 }; 100 int i; 101 102 for_each_possible_cpu(i) { 103 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 104 105 sum.rx_packets += tstats->rx_packets; 106 sum.rx_bytes += tstats->rx_bytes; 107 sum.tx_packets += tstats->tx_packets; 108 sum.tx_bytes += tstats->tx_bytes; 109 } 110 dev->stats.rx_packets = sum.rx_packets; 111 dev->stats.rx_bytes = sum.rx_bytes; 112 dev->stats.tx_packets = sum.tx_packets; 113 dev->stats.tx_bytes = sum.tx_bytes; 114 return &dev->stats; 115 } 116 117 /* 118 * Locking : hash tables are protected by RCU and RTNL 119 */ 120 121 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 122 { 123 struct dst_entry *dst = t->dst_cache; 124 125 if (dst && dst->obsolete && 126 dst->ops->check(dst, t->dst_cookie) == NULL) { 127 t->dst_cache = NULL; 128 dst_release(dst); 129 return NULL; 130 } 131 132 return dst; 133 } 134 135 static inline void ip6_tnl_dst_reset(struct ip6_tnl *t) 136 { 137 dst_release(t->dst_cache); 138 t->dst_cache = NULL; 139 } 140 141 static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 142 { 143 struct rt6_info *rt = (struct rt6_info *) dst; 144 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 145 dst_release(t->dst_cache); 146 t->dst_cache = dst; 147 } 148 149 /** 150 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses 151 * @remote: the address of the tunnel exit-point 152 * @local: the address of the tunnel entry-point 153 * 154 * Return: 155 * tunnel matching given end-points if found, 156 * else fallback tunnel if its device is up, 157 * else %NULL 158 **/ 159 160 #define for_each_ip6_tunnel_rcu(start) \ 161 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 162 163 static struct ip6_tnl * 164 ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local) 165 { 166 unsigned int h0 = HASH(remote); 167 unsigned int h1 = HASH(local); 168 struct ip6_tnl *t; 169 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 170 171 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) { 172 if (ipv6_addr_equal(local, &t->parms.laddr) && 173 ipv6_addr_equal(remote, &t->parms.raddr) && 174 (t->dev->flags & IFF_UP)) 175 return t; 176 } 177 t = rcu_dereference(ip6n->tnls_wc[0]); 178 if (t && (t->dev->flags & IFF_UP)) 179 return t; 180 181 return NULL; 182 } 183 184 /** 185 * ip6_tnl_bucket - get head of list matching given tunnel parameters 186 * @p: parameters containing tunnel end-points 187 * 188 * Description: 189 * ip6_tnl_bucket() returns the head of the list matching the 190 * &struct in6_addr entries laddr and raddr in @p. 191 * 192 * Return: head of IPv6 tunnel list 193 **/ 194 195 static struct ip6_tnl __rcu ** 196 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, struct ip6_tnl_parm *p) 197 { 198 struct in6_addr *remote = &p->raddr; 199 struct in6_addr *local = &p->laddr; 200 unsigned h = 0; 201 int prio = 0; 202 203 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 204 prio = 1; 205 h = HASH(remote) ^ HASH(local); 206 } 207 return &ip6n->tnls[prio][h]; 208 } 209 210 /** 211 * ip6_tnl_link - add tunnel to hash table 212 * @t: tunnel to be added 213 **/ 214 215 static void 216 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 217 { 218 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); 219 220 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 221 rcu_assign_pointer(*tp, t); 222 } 223 224 /** 225 * ip6_tnl_unlink - remove tunnel from hash table 226 * @t: tunnel to be removed 227 **/ 228 229 static void 230 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 231 { 232 struct ip6_tnl __rcu **tp; 233 struct ip6_tnl *iter; 234 235 for (tp = ip6_tnl_bucket(ip6n, &t->parms); 236 (iter = rtnl_dereference(*tp)) != NULL; 237 tp = &iter->next) { 238 if (t == iter) { 239 rcu_assign_pointer(*tp, t->next); 240 break; 241 } 242 } 243 } 244 245 static void ip6_dev_free(struct net_device *dev) 246 { 247 free_percpu(dev->tstats); 248 free_netdev(dev); 249 } 250 251 /** 252 * ip6_tnl_create() - create a new tunnel 253 * @p: tunnel parameters 254 * @pt: pointer to new tunnel 255 * 256 * Description: 257 * Create tunnel matching given parameters. 258 * 259 * Return: 260 * created tunnel or NULL 261 **/ 262 263 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p) 264 { 265 struct net_device *dev; 266 struct ip6_tnl *t; 267 char name[IFNAMSIZ]; 268 int err; 269 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 270 271 if (p->name[0]) 272 strlcpy(name, p->name, IFNAMSIZ); 273 else 274 sprintf(name, "ip6tnl%%d"); 275 276 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); 277 if (dev == NULL) 278 goto failed; 279 280 dev_net_set(dev, net); 281 282 if (strchr(name, '%')) { 283 if (dev_alloc_name(dev, name) < 0) 284 goto failed_free; 285 } 286 287 t = netdev_priv(dev); 288 t->parms = *p; 289 err = ip6_tnl_dev_init(dev); 290 if (err < 0) 291 goto failed_free; 292 293 if ((err = register_netdevice(dev)) < 0) 294 goto failed_free; 295 296 dev_hold(dev); 297 ip6_tnl_link(ip6n, t); 298 return t; 299 300 failed_free: 301 ip6_dev_free(dev); 302 failed: 303 return NULL; 304 } 305 306 /** 307 * ip6_tnl_locate - find or create tunnel matching given parameters 308 * @p: tunnel parameters 309 * @create: != 0 if allowed to create new tunnel if no match found 310 * 311 * Description: 312 * ip6_tnl_locate() first tries to locate an existing tunnel 313 * based on @parms. If this is unsuccessful, but @create is set a new 314 * tunnel device is created and registered for use. 315 * 316 * Return: 317 * matching tunnel or NULL 318 **/ 319 320 static struct ip6_tnl *ip6_tnl_locate(struct net *net, 321 struct ip6_tnl_parm *p, int create) 322 { 323 struct in6_addr *remote = &p->raddr; 324 struct in6_addr *local = &p->laddr; 325 struct ip6_tnl __rcu **tp; 326 struct ip6_tnl *t; 327 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 328 329 for (tp = ip6_tnl_bucket(ip6n, p); 330 (t = rtnl_dereference(*tp)) != NULL; 331 tp = &t->next) { 332 if (ipv6_addr_equal(local, &t->parms.laddr) && 333 ipv6_addr_equal(remote, &t->parms.raddr)) 334 return t; 335 } 336 if (!create) 337 return NULL; 338 return ip6_tnl_create(net, p); 339 } 340 341 /** 342 * ip6_tnl_dev_uninit - tunnel device uninitializer 343 * @dev: the device to be destroyed 344 * 345 * Description: 346 * ip6_tnl_dev_uninit() removes tunnel from its list 347 **/ 348 349 static void 350 ip6_tnl_dev_uninit(struct net_device *dev) 351 { 352 struct ip6_tnl *t = netdev_priv(dev); 353 struct net *net = dev_net(dev); 354 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 355 356 if (dev == ip6n->fb_tnl_dev) 357 rcu_assign_pointer(ip6n->tnls_wc[0], NULL); 358 else 359 ip6_tnl_unlink(ip6n, t); 360 ip6_tnl_dst_reset(t); 361 dev_put(dev); 362 } 363 364 /** 365 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 366 * @skb: received socket buffer 367 * 368 * Return: 369 * 0 if none was found, 370 * else index to encapsulation limit 371 **/ 372 373 static __u16 374 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) 375 { 376 struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; 377 __u8 nexthdr = ipv6h->nexthdr; 378 __u16 off = sizeof (*ipv6h); 379 380 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 381 __u16 optlen = 0; 382 struct ipv6_opt_hdr *hdr; 383 if (raw + off + sizeof (*hdr) > skb->data && 384 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 385 break; 386 387 hdr = (struct ipv6_opt_hdr *) (raw + off); 388 if (nexthdr == NEXTHDR_FRAGMENT) { 389 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 390 if (frag_hdr->frag_off) 391 break; 392 optlen = 8; 393 } else if (nexthdr == NEXTHDR_AUTH) { 394 optlen = (hdr->hdrlen + 2) << 2; 395 } else { 396 optlen = ipv6_optlen(hdr); 397 } 398 if (nexthdr == NEXTHDR_DEST) { 399 __u16 i = off + 2; 400 while (1) { 401 struct ipv6_tlv_tnl_enc_lim *tel; 402 403 /* No more room for encapsulation limit */ 404 if (i + sizeof (*tel) > off + optlen) 405 break; 406 407 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 408 /* return index of option if found and valid */ 409 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 410 tel->length == 1) 411 return i; 412 /* else jump to next option */ 413 if (tel->type) 414 i += tel->length + 2; 415 else 416 i++; 417 } 418 } 419 nexthdr = hdr->nexthdr; 420 off += optlen; 421 } 422 return 0; 423 } 424 425 /** 426 * ip6_tnl_err - tunnel error handler 427 * 428 * Description: 429 * ip6_tnl_err() should handle errors in the tunnel according 430 * to the specifications in RFC 2473. 431 **/ 432 433 static int 434 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, 435 u8 *type, u8 *code, int *msg, __u32 *info, int offset) 436 { 437 struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; 438 struct ip6_tnl *t; 439 int rel_msg = 0; 440 u8 rel_type = ICMPV6_DEST_UNREACH; 441 u8 rel_code = ICMPV6_ADDR_UNREACH; 442 __u32 rel_info = 0; 443 __u16 len; 444 int err = -ENOENT; 445 446 /* If the packet doesn't contain the original IPv6 header we are 447 in trouble since we might need the source address for further 448 processing of the error. */ 449 450 rcu_read_lock(); 451 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, 452 &ipv6h->saddr)) == NULL) 453 goto out; 454 455 if (t->parms.proto != ipproto && t->parms.proto != 0) 456 goto out; 457 458 err = 0; 459 460 switch (*type) { 461 __u32 teli; 462 struct ipv6_tlv_tnl_enc_lim *tel; 463 __u32 mtu; 464 case ICMPV6_DEST_UNREACH: 465 if (net_ratelimit()) 466 printk(KERN_WARNING 467 "%s: Path to destination invalid " 468 "or inactive!\n", t->parms.name); 469 rel_msg = 1; 470 break; 471 case ICMPV6_TIME_EXCEED: 472 if ((*code) == ICMPV6_EXC_HOPLIMIT) { 473 if (net_ratelimit()) 474 printk(KERN_WARNING 475 "%s: Too small hop limit or " 476 "routing loop in tunnel!\n", 477 t->parms.name); 478 rel_msg = 1; 479 } 480 break; 481 case ICMPV6_PARAMPROB: 482 teli = 0; 483 if ((*code) == ICMPV6_HDR_FIELD) 484 teli = parse_tlv_tnl_enc_lim(skb, skb->data); 485 486 if (teli && teli == *info - 2) { 487 tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli]; 488 if (tel->encap_limit == 0) { 489 if (net_ratelimit()) 490 printk(KERN_WARNING 491 "%s: Too small encapsulation " 492 "limit or routing loop in " 493 "tunnel!\n", t->parms.name); 494 rel_msg = 1; 495 } 496 } else if (net_ratelimit()) { 497 printk(KERN_WARNING 498 "%s: Recipient unable to parse tunneled " 499 "packet!\n ", t->parms.name); 500 } 501 break; 502 case ICMPV6_PKT_TOOBIG: 503 mtu = *info - offset; 504 if (mtu < IPV6_MIN_MTU) 505 mtu = IPV6_MIN_MTU; 506 t->dev->mtu = mtu; 507 508 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 509 rel_type = ICMPV6_PKT_TOOBIG; 510 rel_code = 0; 511 rel_info = mtu; 512 rel_msg = 1; 513 } 514 break; 515 } 516 517 *type = rel_type; 518 *code = rel_code; 519 *info = rel_info; 520 *msg = rel_msg; 521 522 out: 523 rcu_read_unlock(); 524 return err; 525 } 526 527 static int 528 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 529 u8 type, u8 code, int offset, __be32 info) 530 { 531 int rel_msg = 0; 532 u8 rel_type = type; 533 u8 rel_code = code; 534 __u32 rel_info = ntohl(info); 535 int err; 536 struct sk_buff *skb2; 537 struct iphdr *eiph; 538 struct flowi fl; 539 struct rtable *rt; 540 541 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, 542 &rel_msg, &rel_info, offset); 543 if (err < 0) 544 return err; 545 546 if (rel_msg == 0) 547 return 0; 548 549 switch (rel_type) { 550 case ICMPV6_DEST_UNREACH: 551 if (rel_code != ICMPV6_ADDR_UNREACH) 552 return 0; 553 rel_type = ICMP_DEST_UNREACH; 554 rel_code = ICMP_HOST_UNREACH; 555 break; 556 case ICMPV6_PKT_TOOBIG: 557 if (rel_code != 0) 558 return 0; 559 rel_type = ICMP_DEST_UNREACH; 560 rel_code = ICMP_FRAG_NEEDED; 561 break; 562 default: 563 return 0; 564 } 565 566 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) 567 return 0; 568 569 skb2 = skb_clone(skb, GFP_ATOMIC); 570 if (!skb2) 571 return 0; 572 573 skb_dst_drop(skb2); 574 575 skb_pull(skb2, offset); 576 skb_reset_network_header(skb2); 577 eiph = ip_hdr(skb2); 578 579 /* Try to guess incoming interface */ 580 memset(&fl, 0, sizeof(fl)); 581 fl.fl4_dst = eiph->saddr; 582 fl.fl4_tos = RT_TOS(eiph->tos); 583 fl.proto = IPPROTO_IPIP; 584 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl)) 585 goto out; 586 587 skb2->dev = rt->dst.dev; 588 589 /* route "incoming" packet */ 590 if (rt->rt_flags & RTCF_LOCAL) { 591 ip_rt_put(rt); 592 rt = NULL; 593 fl.fl4_dst = eiph->daddr; 594 fl.fl4_src = eiph->saddr; 595 fl.fl4_tos = eiph->tos; 596 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl) || 597 rt->dst.dev->type != ARPHRD_TUNNEL) { 598 ip_rt_put(rt); 599 goto out; 600 } 601 skb_dst_set(skb2, (struct dst_entry *)rt); 602 } else { 603 ip_rt_put(rt); 604 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, 605 skb2->dev) || 606 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) 607 goto out; 608 } 609 610 /* change mtu on this route */ 611 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { 612 if (rel_info > dst_mtu(skb_dst(skb2))) 613 goto out; 614 615 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), rel_info); 616 } 617 618 icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); 619 620 out: 621 kfree_skb(skb2); 622 return 0; 623 } 624 625 static int 626 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 627 u8 type, u8 code, int offset, __be32 info) 628 { 629 int rel_msg = 0; 630 u8 rel_type = type; 631 u8 rel_code = code; 632 __u32 rel_info = ntohl(info); 633 int err; 634 635 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, 636 &rel_msg, &rel_info, offset); 637 if (err < 0) 638 return err; 639 640 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { 641 struct rt6_info *rt; 642 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 643 644 if (!skb2) 645 return 0; 646 647 skb_dst_drop(skb2); 648 skb_pull(skb2, offset); 649 skb_reset_network_header(skb2); 650 651 /* Try to guess incoming interface */ 652 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, 653 NULL, 0, 0); 654 655 if (rt && rt->rt6i_dev) 656 skb2->dev = rt->rt6i_dev; 657 658 icmpv6_send(skb2, rel_type, rel_code, rel_info); 659 660 if (rt) 661 dst_release(&rt->dst); 662 663 kfree_skb(skb2); 664 } 665 666 return 0; 667 } 668 669 static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, 670 struct ipv6hdr *ipv6h, 671 struct sk_buff *skb) 672 { 673 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; 674 675 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 676 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); 677 678 if (INET_ECN_is_ce(dsfield)) 679 IP_ECN_set_ce(ip_hdr(skb)); 680 } 681 682 static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, 683 struct ipv6hdr *ipv6h, 684 struct sk_buff *skb) 685 { 686 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 687 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); 688 689 if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h))) 690 IP6_ECN_set_ce(ipv6_hdr(skb)); 691 } 692 693 /* called with rcu_read_lock() */ 694 static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t) 695 { 696 struct ip6_tnl_parm *p = &t->parms; 697 int ret = 0; 698 struct net *net = dev_net(t->dev); 699 700 if (p->flags & IP6_TNL_F_CAP_RCV) { 701 struct net_device *ldev = NULL; 702 703 if (p->link) 704 ldev = dev_get_by_index_rcu(net, p->link); 705 706 if ((ipv6_addr_is_multicast(&p->laddr) || 707 likely(ipv6_chk_addr(net, &p->laddr, ldev, 0))) && 708 likely(!ipv6_chk_addr(net, &p->raddr, NULL, 0))) 709 ret = 1; 710 711 } 712 return ret; 713 } 714 715 /** 716 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally 717 * @skb: received socket buffer 718 * @protocol: ethernet protocol ID 719 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN 720 * 721 * Return: 0 722 **/ 723 724 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, 725 __u8 ipproto, 726 void (*dscp_ecn_decapsulate)(struct ip6_tnl *t, 727 struct ipv6hdr *ipv6h, 728 struct sk_buff *skb)) 729 { 730 struct ip6_tnl *t; 731 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 732 733 rcu_read_lock(); 734 735 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, 736 &ipv6h->daddr)) != NULL) { 737 struct pcpu_tstats *tstats; 738 739 if (t->parms.proto != ipproto && t->parms.proto != 0) { 740 rcu_read_unlock(); 741 goto discard; 742 } 743 744 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 745 rcu_read_unlock(); 746 goto discard; 747 } 748 749 if (!ip6_tnl_rcv_ctl(t)) { 750 t->dev->stats.rx_dropped++; 751 rcu_read_unlock(); 752 goto discard; 753 } 754 secpath_reset(skb); 755 skb->mac_header = skb->network_header; 756 skb_reset_network_header(skb); 757 skb->protocol = htons(protocol); 758 skb->pkt_type = PACKET_HOST; 759 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 760 761 tstats = this_cpu_ptr(t->dev->tstats); 762 tstats->rx_packets++; 763 tstats->rx_bytes += skb->len; 764 765 __skb_tunnel_rx(skb, t->dev); 766 767 dscp_ecn_decapsulate(t, ipv6h, skb); 768 769 netif_rx(skb); 770 771 rcu_read_unlock(); 772 return 0; 773 } 774 rcu_read_unlock(); 775 return 1; 776 777 discard: 778 kfree_skb(skb); 779 return 0; 780 } 781 782 static int ip4ip6_rcv(struct sk_buff *skb) 783 { 784 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, 785 ip4ip6_dscp_ecn_decapsulate); 786 } 787 788 static int ip6ip6_rcv(struct sk_buff *skb) 789 { 790 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, 791 ip6ip6_dscp_ecn_decapsulate); 792 } 793 794 struct ipv6_tel_txoption { 795 struct ipv6_txoptions ops; 796 __u8 dst_opt[8]; 797 }; 798 799 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 800 { 801 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 802 803 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 804 opt->dst_opt[3] = 1; 805 opt->dst_opt[4] = encap_limit; 806 opt->dst_opt[5] = IPV6_TLV_PADN; 807 opt->dst_opt[6] = 1; 808 809 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 810 opt->ops.opt_nflen = 8; 811 } 812 813 /** 814 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 815 * @t: the outgoing tunnel device 816 * @hdr: IPv6 header from the incoming packet 817 * 818 * Description: 819 * Avoid trivial tunneling loop by checking that tunnel exit-point 820 * doesn't match source of incoming packet. 821 * 822 * Return: 823 * 1 if conflict, 824 * 0 else 825 **/ 826 827 static inline int 828 ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) 829 { 830 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 831 } 832 833 static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 834 { 835 struct ip6_tnl_parm *p = &t->parms; 836 int ret = 0; 837 struct net *net = dev_net(t->dev); 838 839 if (p->flags & IP6_TNL_F_CAP_XMIT) { 840 struct net_device *ldev = NULL; 841 842 rcu_read_lock(); 843 if (p->link) 844 ldev = dev_get_by_index_rcu(net, p->link); 845 846 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) 847 printk(KERN_WARNING 848 "%s xmit: Local address not yet configured!\n", 849 p->name); 850 else if (!ipv6_addr_is_multicast(&p->raddr) && 851 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) 852 printk(KERN_WARNING 853 "%s xmit: Routing loop! " 854 "Remote address found on this node!\n", 855 p->name); 856 else 857 ret = 1; 858 rcu_read_unlock(); 859 } 860 return ret; 861 } 862 /** 863 * ip6_tnl_xmit2 - encapsulate packet and send 864 * @skb: the outgoing socket buffer 865 * @dev: the outgoing tunnel device 866 * @dsfield: dscp code for outer header 867 * @fl: flow of tunneled packet 868 * @encap_limit: encapsulation limit 869 * @pmtu: Path MTU is stored if packet is too big 870 * 871 * Description: 872 * Build new header and do some sanity checks on the packet before sending 873 * it. 874 * 875 * Return: 876 * 0 on success 877 * -1 fail 878 * %-EMSGSIZE message too big. return mtu in this case. 879 **/ 880 881 static int ip6_tnl_xmit2(struct sk_buff *skb, 882 struct net_device *dev, 883 __u8 dsfield, 884 struct flowi *fl, 885 int encap_limit, 886 __u32 *pmtu) 887 { 888 struct net *net = dev_net(dev); 889 struct ip6_tnl *t = netdev_priv(dev); 890 struct net_device_stats *stats = &t->dev->stats; 891 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 892 struct ipv6_tel_txoption opt; 893 struct dst_entry *dst; 894 struct net_device *tdev; 895 int mtu; 896 unsigned int max_headroom = sizeof(struct ipv6hdr); 897 u8 proto; 898 int err = -1; 899 int pkt_len; 900 901 if ((dst = ip6_tnl_dst_check(t)) != NULL) 902 dst_hold(dst); 903 else { 904 dst = ip6_route_output(net, NULL, fl); 905 906 if (dst->error || xfrm_lookup(net, &dst, fl, NULL, 0) < 0) 907 goto tx_err_link_failure; 908 } 909 910 tdev = dst->dev; 911 912 if (tdev == dev) { 913 stats->collisions++; 914 if (net_ratelimit()) 915 printk(KERN_WARNING 916 "%s: Local routing loop detected!\n", 917 t->parms.name); 918 goto tx_err_dst_release; 919 } 920 mtu = dst_mtu(dst) - sizeof (*ipv6h); 921 if (encap_limit >= 0) { 922 max_headroom += 8; 923 mtu -= 8; 924 } 925 if (mtu < IPV6_MIN_MTU) 926 mtu = IPV6_MIN_MTU; 927 if (skb_dst(skb)) 928 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 929 if (skb->len > mtu) { 930 *pmtu = mtu; 931 err = -EMSGSIZE; 932 goto tx_err_dst_release; 933 } 934 935 /* 936 * Okay, now see if we can stuff it in the buffer as-is. 937 */ 938 max_headroom += LL_RESERVED_SPACE(tdev); 939 940 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 941 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 942 struct sk_buff *new_skb; 943 944 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 945 goto tx_err_dst_release; 946 947 if (skb->sk) 948 skb_set_owner_w(new_skb, skb->sk); 949 kfree_skb(skb); 950 skb = new_skb; 951 } 952 skb_dst_drop(skb); 953 skb_dst_set(skb, dst_clone(dst)); 954 955 skb->transport_header = skb->network_header; 956 957 proto = fl->proto; 958 if (encap_limit >= 0) { 959 init_tel_txopt(&opt, encap_limit); 960 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 961 } 962 skb_push(skb, sizeof(struct ipv6hdr)); 963 skb_reset_network_header(skb); 964 ipv6h = ipv6_hdr(skb); 965 *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000); 966 dsfield = INET_ECN_encapsulate(0, dsfield); 967 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 968 ipv6h->hop_limit = t->parms.hop_limit; 969 ipv6h->nexthdr = proto; 970 ipv6_addr_copy(&ipv6h->saddr, &fl->fl6_src); 971 ipv6_addr_copy(&ipv6h->daddr, &fl->fl6_dst); 972 nf_reset(skb); 973 pkt_len = skb->len; 974 err = ip6_local_out(skb); 975 976 if (net_xmit_eval(err) == 0) { 977 struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats); 978 979 tstats->tx_bytes += pkt_len; 980 tstats->tx_packets++; 981 } else { 982 stats->tx_errors++; 983 stats->tx_aborted_errors++; 984 } 985 ip6_tnl_dst_store(t, dst); 986 return 0; 987 tx_err_link_failure: 988 stats->tx_carrier_errors++; 989 dst_link_failure(skb); 990 tx_err_dst_release: 991 dst_release(dst); 992 return err; 993 } 994 995 static inline int 996 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 997 { 998 struct ip6_tnl *t = netdev_priv(dev); 999 struct iphdr *iph = ip_hdr(skb); 1000 int encap_limit = -1; 1001 struct flowi fl; 1002 __u8 dsfield; 1003 __u32 mtu; 1004 int err; 1005 1006 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || 1007 !ip6_tnl_xmit_ctl(t)) 1008 return -1; 1009 1010 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1011 encap_limit = t->parms.encap_limit; 1012 1013 memcpy(&fl, &t->fl, sizeof (fl)); 1014 fl.proto = IPPROTO_IPIP; 1015 1016 dsfield = ipv4_get_dsfield(iph); 1017 1018 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 1019 fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) 1020 & IPV6_TCLASS_MASK; 1021 1022 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); 1023 if (err != 0) { 1024 /* XXX: send ICMP error even if DF is not set. */ 1025 if (err == -EMSGSIZE) 1026 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 1027 htonl(mtu)); 1028 return -1; 1029 } 1030 1031 return 0; 1032 } 1033 1034 static inline int 1035 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1036 { 1037 struct ip6_tnl *t = netdev_priv(dev); 1038 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1039 int encap_limit = -1; 1040 __u16 offset; 1041 struct flowi fl; 1042 __u8 dsfield; 1043 __u32 mtu; 1044 int err; 1045 1046 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 1047 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) 1048 return -1; 1049 1050 offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb)); 1051 if (offset > 0) { 1052 struct ipv6_tlv_tnl_enc_lim *tel; 1053 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; 1054 if (tel->encap_limit == 0) { 1055 icmpv6_send(skb, ICMPV6_PARAMPROB, 1056 ICMPV6_HDR_FIELD, offset + 2); 1057 return -1; 1058 } 1059 encap_limit = tel->encap_limit - 1; 1060 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1061 encap_limit = t->parms.encap_limit; 1062 1063 memcpy(&fl, &t->fl, sizeof (fl)); 1064 fl.proto = IPPROTO_IPV6; 1065 1066 dsfield = ipv6_get_dsfield(ipv6h); 1067 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 1068 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 1069 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1070 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); 1071 1072 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); 1073 if (err != 0) { 1074 if (err == -EMSGSIZE) 1075 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1076 return -1; 1077 } 1078 1079 return 0; 1080 } 1081 1082 static netdev_tx_t 1083 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1084 { 1085 struct ip6_tnl *t = netdev_priv(dev); 1086 struct net_device_stats *stats = &t->dev->stats; 1087 int ret; 1088 1089 switch (skb->protocol) { 1090 case htons(ETH_P_IP): 1091 ret = ip4ip6_tnl_xmit(skb, dev); 1092 break; 1093 case htons(ETH_P_IPV6): 1094 ret = ip6ip6_tnl_xmit(skb, dev); 1095 break; 1096 default: 1097 goto tx_err; 1098 } 1099 1100 if (ret < 0) 1101 goto tx_err; 1102 1103 return NETDEV_TX_OK; 1104 1105 tx_err: 1106 stats->tx_errors++; 1107 stats->tx_dropped++; 1108 kfree_skb(skb); 1109 return NETDEV_TX_OK; 1110 } 1111 1112 static void ip6_tnl_set_cap(struct ip6_tnl *t) 1113 { 1114 struct ip6_tnl_parm *p = &t->parms; 1115 int ltype = ipv6_addr_type(&p->laddr); 1116 int rtype = ipv6_addr_type(&p->raddr); 1117 1118 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); 1119 1120 if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 1121 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 1122 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 1123 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 1124 if (ltype&IPV6_ADDR_UNICAST) 1125 p->flags |= IP6_TNL_F_CAP_XMIT; 1126 if (rtype&IPV6_ADDR_UNICAST) 1127 p->flags |= IP6_TNL_F_CAP_RCV; 1128 } 1129 } 1130 1131 static void ip6_tnl_link_config(struct ip6_tnl *t) 1132 { 1133 struct net_device *dev = t->dev; 1134 struct ip6_tnl_parm *p = &t->parms; 1135 struct flowi *fl = &t->fl; 1136 1137 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 1138 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 1139 1140 /* Set up flowi template */ 1141 ipv6_addr_copy(&fl->fl6_src, &p->laddr); 1142 ipv6_addr_copy(&fl->fl6_dst, &p->raddr); 1143 fl->oif = p->link; 1144 fl->fl6_flowlabel = 0; 1145 1146 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 1147 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 1148 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1149 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 1150 1151 ip6_tnl_set_cap(t); 1152 1153 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 1154 dev->flags |= IFF_POINTOPOINT; 1155 else 1156 dev->flags &= ~IFF_POINTOPOINT; 1157 1158 dev->iflink = p->link; 1159 1160 if (p->flags & IP6_TNL_F_CAP_XMIT) { 1161 int strict = (ipv6_addr_type(&p->raddr) & 1162 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 1163 1164 struct rt6_info *rt = rt6_lookup(dev_net(dev), 1165 &p->raddr, &p->laddr, 1166 p->link, strict); 1167 1168 if (rt == NULL) 1169 return; 1170 1171 if (rt->rt6i_dev) { 1172 dev->hard_header_len = rt->rt6i_dev->hard_header_len + 1173 sizeof (struct ipv6hdr); 1174 1175 dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); 1176 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1177 dev->mtu-=8; 1178 1179 if (dev->mtu < IPV6_MIN_MTU) 1180 dev->mtu = IPV6_MIN_MTU; 1181 } 1182 dst_release(&rt->dst); 1183 } 1184 } 1185 1186 /** 1187 * ip6_tnl_change - update the tunnel parameters 1188 * @t: tunnel to be changed 1189 * @p: tunnel configuration parameters 1190 * 1191 * Description: 1192 * ip6_tnl_change() updates the tunnel parameters 1193 **/ 1194 1195 static int 1196 ip6_tnl_change(struct ip6_tnl *t, struct ip6_tnl_parm *p) 1197 { 1198 ipv6_addr_copy(&t->parms.laddr, &p->laddr); 1199 ipv6_addr_copy(&t->parms.raddr, &p->raddr); 1200 t->parms.flags = p->flags; 1201 t->parms.hop_limit = p->hop_limit; 1202 t->parms.encap_limit = p->encap_limit; 1203 t->parms.flowinfo = p->flowinfo; 1204 t->parms.link = p->link; 1205 t->parms.proto = p->proto; 1206 ip6_tnl_dst_reset(t); 1207 ip6_tnl_link_config(t); 1208 return 0; 1209 } 1210 1211 /** 1212 * ip6_tnl_ioctl - configure ipv6 tunnels from userspace 1213 * @dev: virtual device associated with tunnel 1214 * @ifr: parameters passed from userspace 1215 * @cmd: command to be performed 1216 * 1217 * Description: 1218 * ip6_tnl_ioctl() is used for managing IPv6 tunnels 1219 * from userspace. 1220 * 1221 * The possible commands are the following: 1222 * %SIOCGETTUNNEL: get tunnel parameters for device 1223 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 1224 * %SIOCCHGTUNNEL: change tunnel parameters to those given 1225 * %SIOCDELTUNNEL: delete tunnel 1226 * 1227 * The fallback device "ip6tnl0", created during module 1228 * initialization, can be used for creating other tunnel devices. 1229 * 1230 * Return: 1231 * 0 on success, 1232 * %-EFAULT if unable to copy data to or from userspace, 1233 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 1234 * %-EINVAL if passed tunnel parameters are invalid, 1235 * %-EEXIST if changing a tunnel's parameters would cause a conflict 1236 * %-ENODEV if attempting to change or delete a nonexisting device 1237 **/ 1238 1239 static int 1240 ip6_tnl_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1241 { 1242 int err = 0; 1243 struct ip6_tnl_parm p; 1244 struct ip6_tnl *t = NULL; 1245 struct net *net = dev_net(dev); 1246 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1247 1248 switch (cmd) { 1249 case SIOCGETTUNNEL: 1250 if (dev == ip6n->fb_tnl_dev) { 1251 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) { 1252 err = -EFAULT; 1253 break; 1254 } 1255 t = ip6_tnl_locate(net, &p, 0); 1256 } 1257 if (t == NULL) 1258 t = netdev_priv(dev); 1259 memcpy(&p, &t->parms, sizeof (p)); 1260 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof (p))) { 1261 err = -EFAULT; 1262 } 1263 break; 1264 case SIOCADDTUNNEL: 1265 case SIOCCHGTUNNEL: 1266 err = -EPERM; 1267 if (!capable(CAP_NET_ADMIN)) 1268 break; 1269 err = -EFAULT; 1270 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1271 break; 1272 err = -EINVAL; 1273 if (p.proto != IPPROTO_IPV6 && p.proto != IPPROTO_IPIP && 1274 p.proto != 0) 1275 break; 1276 t = ip6_tnl_locate(net, &p, cmd == SIOCADDTUNNEL); 1277 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 1278 if (t != NULL) { 1279 if (t->dev != dev) { 1280 err = -EEXIST; 1281 break; 1282 } 1283 } else 1284 t = netdev_priv(dev); 1285 1286 ip6_tnl_unlink(ip6n, t); 1287 synchronize_net(); 1288 err = ip6_tnl_change(t, &p); 1289 ip6_tnl_link(ip6n, t); 1290 netdev_state_change(dev); 1291 } 1292 if (t) { 1293 err = 0; 1294 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p))) 1295 err = -EFAULT; 1296 1297 } else 1298 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1299 break; 1300 case SIOCDELTUNNEL: 1301 err = -EPERM; 1302 if (!capable(CAP_NET_ADMIN)) 1303 break; 1304 1305 if (dev == ip6n->fb_tnl_dev) { 1306 err = -EFAULT; 1307 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1308 break; 1309 err = -ENOENT; 1310 if ((t = ip6_tnl_locate(net, &p, 0)) == NULL) 1311 break; 1312 err = -EPERM; 1313 if (t->dev == ip6n->fb_tnl_dev) 1314 break; 1315 dev = t->dev; 1316 } 1317 err = 0; 1318 unregister_netdevice(dev); 1319 break; 1320 default: 1321 err = -EINVAL; 1322 } 1323 return err; 1324 } 1325 1326 /** 1327 * ip6_tnl_change_mtu - change mtu manually for tunnel device 1328 * @dev: virtual device associated with tunnel 1329 * @new_mtu: the new mtu 1330 * 1331 * Return: 1332 * 0 on success, 1333 * %-EINVAL if mtu too small 1334 **/ 1335 1336 static int 1337 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1338 { 1339 if (new_mtu < IPV6_MIN_MTU) { 1340 return -EINVAL; 1341 } 1342 dev->mtu = new_mtu; 1343 return 0; 1344 } 1345 1346 1347 static const struct net_device_ops ip6_tnl_netdev_ops = { 1348 .ndo_uninit = ip6_tnl_dev_uninit, 1349 .ndo_start_xmit = ip6_tnl_xmit, 1350 .ndo_do_ioctl = ip6_tnl_ioctl, 1351 .ndo_change_mtu = ip6_tnl_change_mtu, 1352 .ndo_get_stats = ip6_get_stats, 1353 }; 1354 1355 1356 /** 1357 * ip6_tnl_dev_setup - setup virtual tunnel device 1358 * @dev: virtual device associated with tunnel 1359 * 1360 * Description: 1361 * Initialize function pointers and device parameters 1362 **/ 1363 1364 static void ip6_tnl_dev_setup(struct net_device *dev) 1365 { 1366 struct ip6_tnl *t; 1367 1368 dev->netdev_ops = &ip6_tnl_netdev_ops; 1369 dev->destructor = ip6_dev_free; 1370 1371 dev->type = ARPHRD_TUNNEL6; 1372 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1373 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1374 t = netdev_priv(dev); 1375 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1376 dev->mtu-=8; 1377 dev->flags |= IFF_NOARP; 1378 dev->addr_len = sizeof(struct in6_addr); 1379 dev->features |= NETIF_F_NETNS_LOCAL; 1380 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1381 } 1382 1383 1384 /** 1385 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1386 * @dev: virtual device associated with tunnel 1387 **/ 1388 1389 static inline int 1390 ip6_tnl_dev_init_gen(struct net_device *dev) 1391 { 1392 struct ip6_tnl *t = netdev_priv(dev); 1393 1394 t->dev = dev; 1395 strcpy(t->parms.name, dev->name); 1396 dev->tstats = alloc_percpu(struct pcpu_tstats); 1397 if (!dev->tstats) 1398 return -ENOMEM; 1399 return 0; 1400 } 1401 1402 /** 1403 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1404 * @dev: virtual device associated with tunnel 1405 **/ 1406 1407 static int ip6_tnl_dev_init(struct net_device *dev) 1408 { 1409 struct ip6_tnl *t = netdev_priv(dev); 1410 int err = ip6_tnl_dev_init_gen(dev); 1411 1412 if (err) 1413 return err; 1414 ip6_tnl_link_config(t); 1415 return 0; 1416 } 1417 1418 /** 1419 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1420 * @dev: fallback device 1421 * 1422 * Return: 0 1423 **/ 1424 1425 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev) 1426 { 1427 struct ip6_tnl *t = netdev_priv(dev); 1428 struct net *net = dev_net(dev); 1429 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1430 int err = ip6_tnl_dev_init_gen(dev); 1431 1432 if (err) 1433 return err; 1434 1435 t->parms.proto = IPPROTO_IPV6; 1436 dev_hold(dev); 1437 rcu_assign_pointer(ip6n->tnls_wc[0], t); 1438 return 0; 1439 } 1440 1441 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { 1442 .handler = ip4ip6_rcv, 1443 .err_handler = ip4ip6_err, 1444 .priority = 1, 1445 }; 1446 1447 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { 1448 .handler = ip6ip6_rcv, 1449 .err_handler = ip6ip6_err, 1450 .priority = 1, 1451 }; 1452 1453 static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) 1454 { 1455 int h; 1456 struct ip6_tnl *t; 1457 LIST_HEAD(list); 1458 1459 for (h = 0; h < HASH_SIZE; h++) { 1460 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1461 while (t != NULL) { 1462 unregister_netdevice_queue(t->dev, &list); 1463 t = rtnl_dereference(t->next); 1464 } 1465 } 1466 1467 t = rtnl_dereference(ip6n->tnls_wc[0]); 1468 unregister_netdevice_queue(t->dev, &list); 1469 unregister_netdevice_many(&list); 1470 } 1471 1472 static int __net_init ip6_tnl_init_net(struct net *net) 1473 { 1474 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1475 int err; 1476 1477 ip6n->tnls[0] = ip6n->tnls_wc; 1478 ip6n->tnls[1] = ip6n->tnls_r_l; 1479 1480 err = -ENOMEM; 1481 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1482 ip6_tnl_dev_setup); 1483 1484 if (!ip6n->fb_tnl_dev) 1485 goto err_alloc_dev; 1486 dev_net_set(ip6n->fb_tnl_dev, net); 1487 1488 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1489 if (err < 0) 1490 goto err_register; 1491 1492 err = register_netdev(ip6n->fb_tnl_dev); 1493 if (err < 0) 1494 goto err_register; 1495 return 0; 1496 1497 err_register: 1498 ip6_dev_free(ip6n->fb_tnl_dev); 1499 err_alloc_dev: 1500 return err; 1501 } 1502 1503 static void __net_exit ip6_tnl_exit_net(struct net *net) 1504 { 1505 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1506 1507 rtnl_lock(); 1508 ip6_tnl_destroy_tunnels(ip6n); 1509 rtnl_unlock(); 1510 } 1511 1512 static struct pernet_operations ip6_tnl_net_ops = { 1513 .init = ip6_tnl_init_net, 1514 .exit = ip6_tnl_exit_net, 1515 .id = &ip6_tnl_net_id, 1516 .size = sizeof(struct ip6_tnl_net), 1517 }; 1518 1519 /** 1520 * ip6_tunnel_init - register protocol and reserve needed resources 1521 * 1522 * Return: 0 on success 1523 **/ 1524 1525 static int __init ip6_tunnel_init(void) 1526 { 1527 int err; 1528 1529 err = register_pernet_device(&ip6_tnl_net_ops); 1530 if (err < 0) 1531 goto out_pernet; 1532 1533 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); 1534 if (err < 0) { 1535 printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n"); 1536 goto out_ip4ip6; 1537 } 1538 1539 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); 1540 if (err < 0) { 1541 printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n"); 1542 goto out_ip6ip6; 1543 } 1544 1545 return 0; 1546 1547 out_ip6ip6: 1548 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); 1549 out_ip4ip6: 1550 unregister_pernet_device(&ip6_tnl_net_ops); 1551 out_pernet: 1552 return err; 1553 } 1554 1555 /** 1556 * ip6_tunnel_cleanup - free resources and unregister protocol 1557 **/ 1558 1559 static void __exit ip6_tunnel_cleanup(void) 1560 { 1561 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) 1562 printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n"); 1563 1564 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1565 printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n"); 1566 1567 unregister_pernet_device(&ip6_tnl_net_ops); 1568 } 1569 1570 module_init(ip6_tunnel_init); 1571 module_exit(ip6_tunnel_cleanup); 1572