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 #define IPV6_TLV_TEL_DST_SIZE 8 62 63 #ifdef IP6_TNL_DEBUG 64 #define IP6_TNL_TRACE(x...) printk(KERN_DEBUG "%s:" x "\n", __func__) 65 #else 66 #define IP6_TNL_TRACE(x...) do {;} while(0) 67 #endif 68 69 #define IPV6_TCLASS_MASK (IPV6_FLOWINFO_MASK & ~IPV6_FLOWLABEL_MASK) 70 #define IPV6_TCLASS_SHIFT 20 71 72 #define HASH_SIZE 32 73 74 #define HASH(addr) ((__force u32)((addr)->s6_addr32[0] ^ (addr)->s6_addr32[1] ^ \ 75 (addr)->s6_addr32[2] ^ (addr)->s6_addr32[3]) & \ 76 (HASH_SIZE - 1)) 77 78 static int ip6_tnl_dev_init(struct net_device *dev); 79 static void ip6_tnl_dev_setup(struct net_device *dev); 80 81 static int ip6_tnl_net_id __read_mostly; 82 struct ip6_tnl_net { 83 /* the IPv6 tunnel fallback device */ 84 struct net_device *fb_tnl_dev; 85 /* lists for storing tunnels in use */ 86 struct ip6_tnl __rcu *tnls_r_l[HASH_SIZE]; 87 struct ip6_tnl __rcu *tnls_wc[1]; 88 struct ip6_tnl __rcu **tnls[2]; 89 }; 90 91 /* often modified stats are per cpu, other are shared (netdev->stats) */ 92 struct pcpu_tstats { 93 unsigned long rx_packets; 94 unsigned long rx_bytes; 95 unsigned long tx_packets; 96 unsigned long tx_bytes; 97 }; 98 99 static struct net_device_stats *ip6_get_stats(struct net_device *dev) 100 { 101 struct pcpu_tstats sum = { 0 }; 102 int i; 103 104 for_each_possible_cpu(i) { 105 const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i); 106 107 sum.rx_packets += tstats->rx_packets; 108 sum.rx_bytes += tstats->rx_bytes; 109 sum.tx_packets += tstats->tx_packets; 110 sum.tx_bytes += tstats->tx_bytes; 111 } 112 dev->stats.rx_packets = sum.rx_packets; 113 dev->stats.rx_bytes = sum.rx_bytes; 114 dev->stats.tx_packets = sum.tx_packets; 115 dev->stats.tx_bytes = sum.tx_bytes; 116 return &dev->stats; 117 } 118 119 /* 120 * Locking : hash tables are protected by RCU and RTNL 121 */ 122 123 static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t) 124 { 125 struct dst_entry *dst = t->dst_cache; 126 127 if (dst && dst->obsolete && 128 dst->ops->check(dst, t->dst_cookie) == NULL) { 129 t->dst_cache = NULL; 130 dst_release(dst); 131 return NULL; 132 } 133 134 return dst; 135 } 136 137 static inline void ip6_tnl_dst_reset(struct ip6_tnl *t) 138 { 139 dst_release(t->dst_cache); 140 t->dst_cache = NULL; 141 } 142 143 static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst) 144 { 145 struct rt6_info *rt = (struct rt6_info *) dst; 146 t->dst_cookie = rt->rt6i_node ? rt->rt6i_node->fn_sernum : 0; 147 dst_release(t->dst_cache); 148 t->dst_cache = dst; 149 } 150 151 /** 152 * ip6_tnl_lookup - fetch tunnel matching the end-point addresses 153 * @remote: the address of the tunnel exit-point 154 * @local: the address of the tunnel entry-point 155 * 156 * Return: 157 * tunnel matching given end-points if found, 158 * else fallback tunnel if its device is up, 159 * else %NULL 160 **/ 161 162 #define for_each_ip6_tunnel_rcu(start) \ 163 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 164 165 static struct ip6_tnl * 166 ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local) 167 { 168 unsigned int h0 = HASH(remote); 169 unsigned int h1 = HASH(local); 170 struct ip6_tnl *t; 171 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 172 173 for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) { 174 if (ipv6_addr_equal(local, &t->parms.laddr) && 175 ipv6_addr_equal(remote, &t->parms.raddr) && 176 (t->dev->flags & IFF_UP)) 177 return t; 178 } 179 t = rcu_dereference(ip6n->tnls_wc[0]); 180 if (t && (t->dev->flags & IFF_UP)) 181 return t; 182 183 return NULL; 184 } 185 186 /** 187 * ip6_tnl_bucket - get head of list matching given tunnel parameters 188 * @p: parameters containing tunnel end-points 189 * 190 * Description: 191 * ip6_tnl_bucket() returns the head of the list matching the 192 * &struct in6_addr entries laddr and raddr in @p. 193 * 194 * Return: head of IPv6 tunnel list 195 **/ 196 197 static struct ip6_tnl __rcu ** 198 ip6_tnl_bucket(struct ip6_tnl_net *ip6n, struct ip6_tnl_parm *p) 199 { 200 struct in6_addr *remote = &p->raddr; 201 struct in6_addr *local = &p->laddr; 202 unsigned h = 0; 203 int prio = 0; 204 205 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 206 prio = 1; 207 h = HASH(remote) ^ HASH(local); 208 } 209 return &ip6n->tnls[prio][h]; 210 } 211 212 /** 213 * ip6_tnl_link - add tunnel to hash table 214 * @t: tunnel to be added 215 **/ 216 217 static void 218 ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 219 { 220 struct ip6_tnl __rcu **tp = ip6_tnl_bucket(ip6n, &t->parms); 221 222 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 223 rcu_assign_pointer(*tp, t); 224 } 225 226 /** 227 * ip6_tnl_unlink - remove tunnel from hash table 228 * @t: tunnel to be removed 229 **/ 230 231 static void 232 ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t) 233 { 234 struct ip6_tnl __rcu **tp; 235 struct ip6_tnl *iter; 236 237 for (tp = ip6_tnl_bucket(ip6n, &t->parms); 238 (iter = rtnl_dereference(*tp)) != NULL; 239 tp = &iter->next) { 240 if (t == iter) { 241 rcu_assign_pointer(*tp, t->next); 242 break; 243 } 244 } 245 } 246 247 static void ip6_dev_free(struct net_device *dev) 248 { 249 free_percpu(dev->tstats); 250 free_netdev(dev); 251 } 252 253 /** 254 * ip6_tnl_create() - create a new tunnel 255 * @p: tunnel parameters 256 * @pt: pointer to new tunnel 257 * 258 * Description: 259 * Create tunnel matching given parameters. 260 * 261 * Return: 262 * created tunnel or NULL 263 **/ 264 265 static struct ip6_tnl *ip6_tnl_create(struct net *net, struct ip6_tnl_parm *p) 266 { 267 struct net_device *dev; 268 struct ip6_tnl *t; 269 char name[IFNAMSIZ]; 270 int err; 271 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 272 273 if (p->name[0]) 274 strlcpy(name, p->name, IFNAMSIZ); 275 else 276 sprintf(name, "ip6tnl%%d"); 277 278 dev = alloc_netdev(sizeof (*t), name, ip6_tnl_dev_setup); 279 if (dev == NULL) 280 goto failed; 281 282 dev_net_set(dev, net); 283 284 if (strchr(name, '%')) { 285 if (dev_alloc_name(dev, name) < 0) 286 goto failed_free; 287 } 288 289 t = netdev_priv(dev); 290 t->parms = *p; 291 err = ip6_tnl_dev_init(dev); 292 if (err < 0) 293 goto failed_free; 294 295 if ((err = register_netdevice(dev)) < 0) 296 goto failed_free; 297 298 dev_hold(dev); 299 ip6_tnl_link(ip6n, t); 300 return t; 301 302 failed_free: 303 ip6_dev_free(dev); 304 failed: 305 return NULL; 306 } 307 308 /** 309 * ip6_tnl_locate - find or create tunnel matching given parameters 310 * @p: tunnel parameters 311 * @create: != 0 if allowed to create new tunnel if no match found 312 * 313 * Description: 314 * ip6_tnl_locate() first tries to locate an existing tunnel 315 * based on @parms. If this is unsuccessful, but @create is set a new 316 * tunnel device is created and registered for use. 317 * 318 * Return: 319 * matching tunnel or NULL 320 **/ 321 322 static struct ip6_tnl *ip6_tnl_locate(struct net *net, 323 struct ip6_tnl_parm *p, int create) 324 { 325 struct in6_addr *remote = &p->raddr; 326 struct in6_addr *local = &p->laddr; 327 struct ip6_tnl __rcu **tp; 328 struct ip6_tnl *t; 329 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 330 331 for (tp = ip6_tnl_bucket(ip6n, p); 332 (t = rtnl_dereference(*tp)) != NULL; 333 tp = &t->next) { 334 if (ipv6_addr_equal(local, &t->parms.laddr) && 335 ipv6_addr_equal(remote, &t->parms.raddr)) 336 return t; 337 } 338 if (!create) 339 return NULL; 340 return ip6_tnl_create(net, p); 341 } 342 343 /** 344 * ip6_tnl_dev_uninit - tunnel device uninitializer 345 * @dev: the device to be destroyed 346 * 347 * Description: 348 * ip6_tnl_dev_uninit() removes tunnel from its list 349 **/ 350 351 static void 352 ip6_tnl_dev_uninit(struct net_device *dev) 353 { 354 struct ip6_tnl *t = netdev_priv(dev); 355 struct net *net = dev_net(dev); 356 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 357 358 if (dev == ip6n->fb_tnl_dev) 359 rcu_assign_pointer(ip6n->tnls_wc[0], NULL); 360 else 361 ip6_tnl_unlink(ip6n, t); 362 ip6_tnl_dst_reset(t); 363 dev_put(dev); 364 } 365 366 /** 367 * parse_tvl_tnl_enc_lim - handle encapsulation limit option 368 * @skb: received socket buffer 369 * 370 * Return: 371 * 0 if none was found, 372 * else index to encapsulation limit 373 **/ 374 375 static __u16 376 parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw) 377 { 378 struct ipv6hdr *ipv6h = (struct ipv6hdr *) raw; 379 __u8 nexthdr = ipv6h->nexthdr; 380 __u16 off = sizeof (*ipv6h); 381 382 while (ipv6_ext_hdr(nexthdr) && nexthdr != NEXTHDR_NONE) { 383 __u16 optlen = 0; 384 struct ipv6_opt_hdr *hdr; 385 if (raw + off + sizeof (*hdr) > skb->data && 386 !pskb_may_pull(skb, raw - skb->data + off + sizeof (*hdr))) 387 break; 388 389 hdr = (struct ipv6_opt_hdr *) (raw + off); 390 if (nexthdr == NEXTHDR_FRAGMENT) { 391 struct frag_hdr *frag_hdr = (struct frag_hdr *) hdr; 392 if (frag_hdr->frag_off) 393 break; 394 optlen = 8; 395 } else if (nexthdr == NEXTHDR_AUTH) { 396 optlen = (hdr->hdrlen + 2) << 2; 397 } else { 398 optlen = ipv6_optlen(hdr); 399 } 400 if (nexthdr == NEXTHDR_DEST) { 401 __u16 i = off + 2; 402 while (1) { 403 struct ipv6_tlv_tnl_enc_lim *tel; 404 405 /* No more room for encapsulation limit */ 406 if (i + sizeof (*tel) > off + optlen) 407 break; 408 409 tel = (struct ipv6_tlv_tnl_enc_lim *) &raw[i]; 410 /* return index of option if found and valid */ 411 if (tel->type == IPV6_TLV_TNL_ENCAP_LIMIT && 412 tel->length == 1) 413 return i; 414 /* else jump to next option */ 415 if (tel->type) 416 i += tel->length + 2; 417 else 418 i++; 419 } 420 } 421 nexthdr = hdr->nexthdr; 422 off += optlen; 423 } 424 return 0; 425 } 426 427 /** 428 * ip6_tnl_err - tunnel error handler 429 * 430 * Description: 431 * ip6_tnl_err() should handle errors in the tunnel according 432 * to the specifications in RFC 2473. 433 **/ 434 435 static int 436 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt, 437 u8 *type, u8 *code, int *msg, __u32 *info, int offset) 438 { 439 struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data; 440 struct ip6_tnl *t; 441 int rel_msg = 0; 442 u8 rel_type = ICMPV6_DEST_UNREACH; 443 u8 rel_code = ICMPV6_ADDR_UNREACH; 444 __u32 rel_info = 0; 445 __u16 len; 446 int err = -ENOENT; 447 448 /* If the packet doesn't contain the original IPv6 header we are 449 in trouble since we might need the source address for further 450 processing of the error. */ 451 452 rcu_read_lock(); 453 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr, 454 &ipv6h->saddr)) == NULL) 455 goto out; 456 457 if (t->parms.proto != ipproto && t->parms.proto != 0) 458 goto out; 459 460 err = 0; 461 462 switch (*type) { 463 __u32 teli; 464 struct ipv6_tlv_tnl_enc_lim *tel; 465 __u32 mtu; 466 case ICMPV6_DEST_UNREACH: 467 if (net_ratelimit()) 468 printk(KERN_WARNING 469 "%s: Path to destination invalid " 470 "or inactive!\n", t->parms.name); 471 rel_msg = 1; 472 break; 473 case ICMPV6_TIME_EXCEED: 474 if ((*code) == ICMPV6_EXC_HOPLIMIT) { 475 if (net_ratelimit()) 476 printk(KERN_WARNING 477 "%s: Too small hop limit or " 478 "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 = parse_tlv_tnl_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 if (net_ratelimit()) 492 printk(KERN_WARNING 493 "%s: Too small encapsulation " 494 "limit or routing loop in " 495 "tunnel!\n", t->parms.name); 496 rel_msg = 1; 497 } 498 } else if (net_ratelimit()) { 499 printk(KERN_WARNING 500 "%s: Recipient unable to parse tunneled " 501 "packet!\n ", t->parms.name); 502 } 503 break; 504 case ICMPV6_PKT_TOOBIG: 505 mtu = *info - offset; 506 if (mtu < IPV6_MIN_MTU) 507 mtu = IPV6_MIN_MTU; 508 t->dev->mtu = mtu; 509 510 if ((len = sizeof (*ipv6h) + ntohs(ipv6h->payload_len)) > mtu) { 511 rel_type = ICMPV6_PKT_TOOBIG; 512 rel_code = 0; 513 rel_info = mtu; 514 rel_msg = 1; 515 } 516 break; 517 } 518 519 *type = rel_type; 520 *code = rel_code; 521 *info = rel_info; 522 *msg = rel_msg; 523 524 out: 525 rcu_read_unlock(); 526 return err; 527 } 528 529 static int 530 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 531 u8 type, u8 code, int offset, __be32 info) 532 { 533 int rel_msg = 0; 534 u8 rel_type = type; 535 u8 rel_code = code; 536 __u32 rel_info = ntohl(info); 537 int err; 538 struct sk_buff *skb2; 539 struct iphdr *eiph; 540 struct flowi fl; 541 struct rtable *rt; 542 543 err = ip6_tnl_err(skb, IPPROTO_IPIP, opt, &rel_type, &rel_code, 544 &rel_msg, &rel_info, offset); 545 if (err < 0) 546 return err; 547 548 if (rel_msg == 0) 549 return 0; 550 551 switch (rel_type) { 552 case ICMPV6_DEST_UNREACH: 553 if (rel_code != ICMPV6_ADDR_UNREACH) 554 return 0; 555 rel_type = ICMP_DEST_UNREACH; 556 rel_code = ICMP_HOST_UNREACH; 557 break; 558 case ICMPV6_PKT_TOOBIG: 559 if (rel_code != 0) 560 return 0; 561 rel_type = ICMP_DEST_UNREACH; 562 rel_code = ICMP_FRAG_NEEDED; 563 break; 564 default: 565 return 0; 566 } 567 568 if (!pskb_may_pull(skb, offset + sizeof(struct iphdr))) 569 return 0; 570 571 skb2 = skb_clone(skb, GFP_ATOMIC); 572 if (!skb2) 573 return 0; 574 575 skb_dst_drop(skb2); 576 577 skb_pull(skb2, offset); 578 skb_reset_network_header(skb2); 579 eiph = ip_hdr(skb2); 580 581 /* Try to guess incoming interface */ 582 memset(&fl, 0, sizeof(fl)); 583 fl.fl4_dst = eiph->saddr; 584 fl.fl4_tos = RT_TOS(eiph->tos); 585 fl.proto = IPPROTO_IPIP; 586 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl)) 587 goto out; 588 589 skb2->dev = rt->dst.dev; 590 591 /* route "incoming" packet */ 592 if (rt->rt_flags & RTCF_LOCAL) { 593 ip_rt_put(rt); 594 rt = NULL; 595 fl.fl4_dst = eiph->daddr; 596 fl.fl4_src = eiph->saddr; 597 fl.fl4_tos = eiph->tos; 598 if (ip_route_output_key(dev_net(skb->dev), &rt, &fl) || 599 rt->dst.dev->type != ARPHRD_TUNNEL) { 600 ip_rt_put(rt); 601 goto out; 602 } 603 skb_dst_set(skb2, (struct dst_entry *)rt); 604 } else { 605 ip_rt_put(rt); 606 if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, 607 skb2->dev) || 608 skb_dst(skb2)->dev->type != ARPHRD_TUNNEL) 609 goto out; 610 } 611 612 /* change mtu on this route */ 613 if (rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) { 614 if (rel_info > dst_mtu(skb_dst(skb2))) 615 goto out; 616 617 skb_dst(skb2)->ops->update_pmtu(skb_dst(skb2), rel_info); 618 } 619 620 icmp_send(skb2, rel_type, rel_code, htonl(rel_info)); 621 622 out: 623 kfree_skb(skb2); 624 return 0; 625 } 626 627 static int 628 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 629 u8 type, u8 code, int offset, __be32 info) 630 { 631 int rel_msg = 0; 632 u8 rel_type = type; 633 u8 rel_code = code; 634 __u32 rel_info = ntohl(info); 635 int err; 636 637 err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code, 638 &rel_msg, &rel_info, offset); 639 if (err < 0) 640 return err; 641 642 if (rel_msg && pskb_may_pull(skb, offset + sizeof(struct ipv6hdr))) { 643 struct rt6_info *rt; 644 struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); 645 646 if (!skb2) 647 return 0; 648 649 skb_dst_drop(skb2); 650 skb_pull(skb2, offset); 651 skb_reset_network_header(skb2); 652 653 /* Try to guess incoming interface */ 654 rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, 655 NULL, 0, 0); 656 657 if (rt && rt->rt6i_dev) 658 skb2->dev = rt->rt6i_dev; 659 660 icmpv6_send(skb2, rel_type, rel_code, rel_info); 661 662 if (rt) 663 dst_release(&rt->dst); 664 665 kfree_skb(skb2); 666 } 667 668 return 0; 669 } 670 671 static void ip4ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, 672 struct ipv6hdr *ipv6h, 673 struct sk_buff *skb) 674 { 675 __u8 dsfield = ipv6_get_dsfield(ipv6h) & ~INET_ECN_MASK; 676 677 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 678 ipv4_change_dsfield(ip_hdr(skb), INET_ECN_MASK, dsfield); 679 680 if (INET_ECN_is_ce(dsfield)) 681 IP_ECN_set_ce(ip_hdr(skb)); 682 } 683 684 static void ip6ip6_dscp_ecn_decapsulate(struct ip6_tnl *t, 685 struct ipv6hdr *ipv6h, 686 struct sk_buff *skb) 687 { 688 if (t->parms.flags & IP6_TNL_F_RCV_DSCP_COPY) 689 ipv6_copy_dscp(ipv6_get_dsfield(ipv6h), ipv6_hdr(skb)); 690 691 if (INET_ECN_is_ce(ipv6_get_dsfield(ipv6h))) 692 IP6_ECN_set_ce(ipv6_hdr(skb)); 693 } 694 695 /* called with rcu_read_lock() */ 696 static inline int ip6_tnl_rcv_ctl(struct ip6_tnl *t) 697 { 698 struct ip6_tnl_parm *p = &t->parms; 699 int ret = 0; 700 struct net *net = dev_net(t->dev); 701 702 if (p->flags & IP6_TNL_F_CAP_RCV) { 703 struct net_device *ldev = NULL; 704 705 if (p->link) 706 ldev = dev_get_by_index_rcu(net, p->link); 707 708 if ((ipv6_addr_is_multicast(&p->laddr) || 709 likely(ipv6_chk_addr(net, &p->laddr, ldev, 0))) && 710 likely(!ipv6_chk_addr(net, &p->raddr, NULL, 0))) 711 ret = 1; 712 713 } 714 return ret; 715 } 716 717 /** 718 * ip6_tnl_rcv - decapsulate IPv6 packet and retransmit it locally 719 * @skb: received socket buffer 720 * @protocol: ethernet protocol ID 721 * @dscp_ecn_decapsulate: the function to decapsulate DSCP code and ECN 722 * 723 * Return: 0 724 **/ 725 726 static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol, 727 __u8 ipproto, 728 void (*dscp_ecn_decapsulate)(struct ip6_tnl *t, 729 struct ipv6hdr *ipv6h, 730 struct sk_buff *skb)) 731 { 732 struct ip6_tnl *t; 733 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 734 735 rcu_read_lock(); 736 737 if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, 738 &ipv6h->daddr)) != NULL) { 739 struct pcpu_tstats *tstats; 740 741 if (t->parms.proto != ipproto && t->parms.proto != 0) { 742 rcu_read_unlock(); 743 goto discard; 744 } 745 746 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 747 rcu_read_unlock(); 748 goto discard; 749 } 750 751 if (!ip6_tnl_rcv_ctl(t)) { 752 t->dev->stats.rx_dropped++; 753 rcu_read_unlock(); 754 goto discard; 755 } 756 secpath_reset(skb); 757 skb->mac_header = skb->network_header; 758 skb_reset_network_header(skb); 759 skb->protocol = htons(protocol); 760 skb->pkt_type = PACKET_HOST; 761 memset(skb->cb, 0, sizeof(struct inet6_skb_parm)); 762 763 tstats = this_cpu_ptr(t->dev->tstats); 764 tstats->rx_packets++; 765 tstats->rx_bytes += skb->len; 766 767 __skb_tunnel_rx(skb, t->dev); 768 769 dscp_ecn_decapsulate(t, ipv6h, skb); 770 771 netif_rx(skb); 772 773 rcu_read_unlock(); 774 return 0; 775 } 776 rcu_read_unlock(); 777 return 1; 778 779 discard: 780 kfree_skb(skb); 781 return 0; 782 } 783 784 static int ip4ip6_rcv(struct sk_buff *skb) 785 { 786 return ip6_tnl_rcv(skb, ETH_P_IP, IPPROTO_IPIP, 787 ip4ip6_dscp_ecn_decapsulate); 788 } 789 790 static int ip6ip6_rcv(struct sk_buff *skb) 791 { 792 return ip6_tnl_rcv(skb, ETH_P_IPV6, IPPROTO_IPV6, 793 ip6ip6_dscp_ecn_decapsulate); 794 } 795 796 struct ipv6_tel_txoption { 797 struct ipv6_txoptions ops; 798 __u8 dst_opt[8]; 799 }; 800 801 static void init_tel_txopt(struct ipv6_tel_txoption *opt, __u8 encap_limit) 802 { 803 memset(opt, 0, sizeof(struct ipv6_tel_txoption)); 804 805 opt->dst_opt[2] = IPV6_TLV_TNL_ENCAP_LIMIT; 806 opt->dst_opt[3] = 1; 807 opt->dst_opt[4] = encap_limit; 808 opt->dst_opt[5] = IPV6_TLV_PADN; 809 opt->dst_opt[6] = 1; 810 811 opt->ops.dst0opt = (struct ipv6_opt_hdr *) opt->dst_opt; 812 opt->ops.opt_nflen = 8; 813 } 814 815 /** 816 * ip6_tnl_addr_conflict - compare packet addresses to tunnel's own 817 * @t: the outgoing tunnel device 818 * @hdr: IPv6 header from the incoming packet 819 * 820 * Description: 821 * Avoid trivial tunneling loop by checking that tunnel exit-point 822 * doesn't match source of incoming packet. 823 * 824 * Return: 825 * 1 if conflict, 826 * 0 else 827 **/ 828 829 static inline int 830 ip6_tnl_addr_conflict(struct ip6_tnl *t, struct ipv6hdr *hdr) 831 { 832 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 833 } 834 835 static inline int ip6_tnl_xmit_ctl(struct ip6_tnl *t) 836 { 837 struct ip6_tnl_parm *p = &t->parms; 838 int ret = 0; 839 struct net *net = dev_net(t->dev); 840 841 if (p->flags & IP6_TNL_F_CAP_XMIT) { 842 struct net_device *ldev = NULL; 843 844 rcu_read_lock(); 845 if (p->link) 846 ldev = dev_get_by_index_rcu(net, p->link); 847 848 if (unlikely(!ipv6_chk_addr(net, &p->laddr, ldev, 0))) 849 printk(KERN_WARNING 850 "%s xmit: Local address not yet configured!\n", 851 p->name); 852 else if (!ipv6_addr_is_multicast(&p->raddr) && 853 unlikely(ipv6_chk_addr(net, &p->raddr, NULL, 0))) 854 printk(KERN_WARNING 855 "%s xmit: Routing loop! " 856 "Remote address found on this node!\n", 857 p->name); 858 else 859 ret = 1; 860 rcu_read_unlock(); 861 } 862 return ret; 863 } 864 /** 865 * ip6_tnl_xmit2 - encapsulate packet and send 866 * @skb: the outgoing socket buffer 867 * @dev: the outgoing tunnel device 868 * @dsfield: dscp code for outer header 869 * @fl: flow of tunneled packet 870 * @encap_limit: encapsulation limit 871 * @pmtu: Path MTU is stored if packet is too big 872 * 873 * Description: 874 * Build new header and do some sanity checks on the packet before sending 875 * it. 876 * 877 * Return: 878 * 0 on success 879 * -1 fail 880 * %-EMSGSIZE message too big. return mtu in this case. 881 **/ 882 883 static int ip6_tnl_xmit2(struct sk_buff *skb, 884 struct net_device *dev, 885 __u8 dsfield, 886 struct flowi *fl, 887 int encap_limit, 888 __u32 *pmtu) 889 { 890 struct net *net = dev_net(dev); 891 struct ip6_tnl *t = netdev_priv(dev); 892 struct net_device_stats *stats = &t->dev->stats; 893 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 894 struct ipv6_tel_txoption opt; 895 struct dst_entry *dst; 896 struct net_device *tdev; 897 int mtu; 898 unsigned int max_headroom = sizeof(struct ipv6hdr); 899 u8 proto; 900 int err = -1; 901 int pkt_len; 902 903 if ((dst = ip6_tnl_dst_check(t)) != NULL) 904 dst_hold(dst); 905 else { 906 dst = ip6_route_output(net, NULL, fl); 907 908 if (dst->error || xfrm_lookup(net, &dst, fl, NULL, 0) < 0) 909 goto tx_err_link_failure; 910 } 911 912 tdev = dst->dev; 913 914 if (tdev == dev) { 915 stats->collisions++; 916 if (net_ratelimit()) 917 printk(KERN_WARNING 918 "%s: Local routing loop detected!\n", 919 t->parms.name); 920 goto tx_err_dst_release; 921 } 922 mtu = dst_mtu(dst) - sizeof (*ipv6h); 923 if (encap_limit >= 0) { 924 max_headroom += 8; 925 mtu -= 8; 926 } 927 if (mtu < IPV6_MIN_MTU) 928 mtu = IPV6_MIN_MTU; 929 if (skb_dst(skb)) 930 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu); 931 if (skb->len > mtu) { 932 *pmtu = mtu; 933 err = -EMSGSIZE; 934 goto tx_err_dst_release; 935 } 936 937 /* 938 * Okay, now see if we can stuff it in the buffer as-is. 939 */ 940 max_headroom += LL_RESERVED_SPACE(tdev); 941 942 if (skb_headroom(skb) < max_headroom || skb_shared(skb) || 943 (skb_cloned(skb) && !skb_clone_writable(skb, 0))) { 944 struct sk_buff *new_skb; 945 946 if (!(new_skb = skb_realloc_headroom(skb, max_headroom))) 947 goto tx_err_dst_release; 948 949 if (skb->sk) 950 skb_set_owner_w(new_skb, skb->sk); 951 kfree_skb(skb); 952 skb = new_skb; 953 } 954 skb_dst_drop(skb); 955 skb_dst_set(skb, dst_clone(dst)); 956 957 skb->transport_header = skb->network_header; 958 959 proto = fl->proto; 960 if (encap_limit >= 0) { 961 init_tel_txopt(&opt, encap_limit); 962 ipv6_push_nfrag_opts(skb, &opt.ops, &proto, NULL); 963 } 964 skb_push(skb, sizeof(struct ipv6hdr)); 965 skb_reset_network_header(skb); 966 ipv6h = ipv6_hdr(skb); 967 *(__be32*)ipv6h = fl->fl6_flowlabel | htonl(0x60000000); 968 dsfield = INET_ECN_encapsulate(0, dsfield); 969 ipv6_change_dsfield(ipv6h, ~INET_ECN_MASK, dsfield); 970 ipv6h->hop_limit = t->parms.hop_limit; 971 ipv6h->nexthdr = proto; 972 ipv6_addr_copy(&ipv6h->saddr, &fl->fl6_src); 973 ipv6_addr_copy(&ipv6h->daddr, &fl->fl6_dst); 974 nf_reset(skb); 975 pkt_len = skb->len; 976 err = ip6_local_out(skb); 977 978 if (net_xmit_eval(err) == 0) { 979 struct pcpu_tstats *tstats = this_cpu_ptr(t->dev->tstats); 980 981 tstats->tx_bytes += pkt_len; 982 tstats->tx_packets++; 983 } else { 984 stats->tx_errors++; 985 stats->tx_aborted_errors++; 986 } 987 ip6_tnl_dst_store(t, dst); 988 return 0; 989 tx_err_link_failure: 990 stats->tx_carrier_errors++; 991 dst_link_failure(skb); 992 tx_err_dst_release: 993 dst_release(dst); 994 return err; 995 } 996 997 static inline int 998 ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 999 { 1000 struct ip6_tnl *t = netdev_priv(dev); 1001 struct iphdr *iph = ip_hdr(skb); 1002 int encap_limit = -1; 1003 struct flowi fl; 1004 __u8 dsfield; 1005 __u32 mtu; 1006 int err; 1007 1008 if ((t->parms.proto != IPPROTO_IPIP && t->parms.proto != 0) || 1009 !ip6_tnl_xmit_ctl(t)) 1010 return -1; 1011 1012 if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1013 encap_limit = t->parms.encap_limit; 1014 1015 memcpy(&fl, &t->fl, sizeof (fl)); 1016 fl.proto = IPPROTO_IPIP; 1017 1018 dsfield = ipv4_get_dsfield(iph); 1019 1020 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 1021 fl.fl6_flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT) 1022 & IPV6_TCLASS_MASK; 1023 1024 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); 1025 if (err != 0) { 1026 /* XXX: send ICMP error even if DF is not set. */ 1027 if (err == -EMSGSIZE) 1028 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 1029 htonl(mtu)); 1030 return -1; 1031 } 1032 1033 return 0; 1034 } 1035 1036 static inline int 1037 ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1038 { 1039 struct ip6_tnl *t = netdev_priv(dev); 1040 struct ipv6hdr *ipv6h = ipv6_hdr(skb); 1041 int encap_limit = -1; 1042 __u16 offset; 1043 struct flowi fl; 1044 __u8 dsfield; 1045 __u32 mtu; 1046 int err; 1047 1048 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 1049 !ip6_tnl_xmit_ctl(t) || ip6_tnl_addr_conflict(t, ipv6h)) 1050 return -1; 1051 1052 offset = parse_tlv_tnl_enc_lim(skb, skb_network_header(skb)); 1053 if (offset > 0) { 1054 struct ipv6_tlv_tnl_enc_lim *tel; 1055 tel = (struct ipv6_tlv_tnl_enc_lim *)&skb_network_header(skb)[offset]; 1056 if (tel->encap_limit == 0) { 1057 icmpv6_send(skb, ICMPV6_PARAMPROB, 1058 ICMPV6_HDR_FIELD, offset + 2); 1059 return -1; 1060 } 1061 encap_limit = tel->encap_limit - 1; 1062 } else if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) 1063 encap_limit = t->parms.encap_limit; 1064 1065 memcpy(&fl, &t->fl, sizeof (fl)); 1066 fl.proto = IPPROTO_IPV6; 1067 1068 dsfield = ipv6_get_dsfield(ipv6h); 1069 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)) 1070 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK); 1071 if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1072 fl.fl6_flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK); 1073 1074 err = ip6_tnl_xmit2(skb, dev, dsfield, &fl, encap_limit, &mtu); 1075 if (err != 0) { 1076 if (err == -EMSGSIZE) 1077 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 1078 return -1; 1079 } 1080 1081 return 0; 1082 } 1083 1084 static netdev_tx_t 1085 ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 1086 { 1087 struct ip6_tnl *t = netdev_priv(dev); 1088 struct net_device_stats *stats = &t->dev->stats; 1089 int ret; 1090 1091 switch (skb->protocol) { 1092 case htons(ETH_P_IP): 1093 ret = ip4ip6_tnl_xmit(skb, dev); 1094 break; 1095 case htons(ETH_P_IPV6): 1096 ret = ip6ip6_tnl_xmit(skb, dev); 1097 break; 1098 default: 1099 goto tx_err; 1100 } 1101 1102 if (ret < 0) 1103 goto tx_err; 1104 1105 return NETDEV_TX_OK; 1106 1107 tx_err: 1108 stats->tx_errors++; 1109 stats->tx_dropped++; 1110 kfree_skb(skb); 1111 return NETDEV_TX_OK; 1112 } 1113 1114 static void ip6_tnl_set_cap(struct ip6_tnl *t) 1115 { 1116 struct ip6_tnl_parm *p = &t->parms; 1117 int ltype = ipv6_addr_type(&p->laddr); 1118 int rtype = ipv6_addr_type(&p->raddr); 1119 1120 p->flags &= ~(IP6_TNL_F_CAP_XMIT|IP6_TNL_F_CAP_RCV); 1121 1122 if (ltype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 1123 rtype & (IPV6_ADDR_UNICAST|IPV6_ADDR_MULTICAST) && 1124 !((ltype|rtype) & IPV6_ADDR_LOOPBACK) && 1125 (!((ltype|rtype) & IPV6_ADDR_LINKLOCAL) || p->link)) { 1126 if (ltype&IPV6_ADDR_UNICAST) 1127 p->flags |= IP6_TNL_F_CAP_XMIT; 1128 if (rtype&IPV6_ADDR_UNICAST) 1129 p->flags |= IP6_TNL_F_CAP_RCV; 1130 } 1131 } 1132 1133 static void ip6_tnl_link_config(struct ip6_tnl *t) 1134 { 1135 struct net_device *dev = t->dev; 1136 struct ip6_tnl_parm *p = &t->parms; 1137 struct flowi *fl = &t->fl; 1138 1139 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 1140 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 1141 1142 /* Set up flowi template */ 1143 ipv6_addr_copy(&fl->fl6_src, &p->laddr); 1144 ipv6_addr_copy(&fl->fl6_dst, &p->raddr); 1145 fl->oif = p->link; 1146 fl->fl6_flowlabel = 0; 1147 1148 if (!(p->flags&IP6_TNL_F_USE_ORIG_TCLASS)) 1149 fl->fl6_flowlabel |= IPV6_TCLASS_MASK & p->flowinfo; 1150 if (!(p->flags&IP6_TNL_F_USE_ORIG_FLOWLABEL)) 1151 fl->fl6_flowlabel |= IPV6_FLOWLABEL_MASK & p->flowinfo; 1152 1153 ip6_tnl_set_cap(t); 1154 1155 if (p->flags&IP6_TNL_F_CAP_XMIT && p->flags&IP6_TNL_F_CAP_RCV) 1156 dev->flags |= IFF_POINTOPOINT; 1157 else 1158 dev->flags &= ~IFF_POINTOPOINT; 1159 1160 dev->iflink = p->link; 1161 1162 if (p->flags & IP6_TNL_F_CAP_XMIT) { 1163 int strict = (ipv6_addr_type(&p->raddr) & 1164 (IPV6_ADDR_MULTICAST|IPV6_ADDR_LINKLOCAL)); 1165 1166 struct rt6_info *rt = rt6_lookup(dev_net(dev), 1167 &p->raddr, &p->laddr, 1168 p->link, strict); 1169 1170 if (rt == NULL) 1171 return; 1172 1173 if (rt->rt6i_dev) { 1174 dev->hard_header_len = rt->rt6i_dev->hard_header_len + 1175 sizeof (struct ipv6hdr); 1176 1177 dev->mtu = rt->rt6i_dev->mtu - sizeof (struct ipv6hdr); 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 err = ip6_tnl_change(t, &p); 1288 ip6_tnl_link(ip6n, t); 1289 netdev_state_change(dev); 1290 } 1291 if (t) { 1292 err = 0; 1293 if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof (p))) 1294 err = -EFAULT; 1295 1296 } else 1297 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 1298 break; 1299 case SIOCDELTUNNEL: 1300 err = -EPERM; 1301 if (!capable(CAP_NET_ADMIN)) 1302 break; 1303 1304 if (dev == ip6n->fb_tnl_dev) { 1305 err = -EFAULT; 1306 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof (p))) 1307 break; 1308 err = -ENOENT; 1309 if ((t = ip6_tnl_locate(net, &p, 0)) == NULL) 1310 break; 1311 err = -EPERM; 1312 if (t->dev == ip6n->fb_tnl_dev) 1313 break; 1314 dev = t->dev; 1315 } 1316 err = 0; 1317 unregister_netdevice(dev); 1318 break; 1319 default: 1320 err = -EINVAL; 1321 } 1322 return err; 1323 } 1324 1325 /** 1326 * ip6_tnl_change_mtu - change mtu manually for tunnel device 1327 * @dev: virtual device associated with tunnel 1328 * @new_mtu: the new mtu 1329 * 1330 * Return: 1331 * 0 on success, 1332 * %-EINVAL if mtu too small 1333 **/ 1334 1335 static int 1336 ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) 1337 { 1338 if (new_mtu < IPV6_MIN_MTU) { 1339 return -EINVAL; 1340 } 1341 dev->mtu = new_mtu; 1342 return 0; 1343 } 1344 1345 1346 static const struct net_device_ops ip6_tnl_netdev_ops = { 1347 .ndo_uninit = ip6_tnl_dev_uninit, 1348 .ndo_start_xmit = ip6_tnl_xmit, 1349 .ndo_do_ioctl = ip6_tnl_ioctl, 1350 .ndo_change_mtu = ip6_tnl_change_mtu, 1351 .ndo_get_stats = ip6_get_stats, 1352 }; 1353 1354 1355 /** 1356 * ip6_tnl_dev_setup - setup virtual tunnel device 1357 * @dev: virtual device associated with tunnel 1358 * 1359 * Description: 1360 * Initialize function pointers and device parameters 1361 **/ 1362 1363 static void ip6_tnl_dev_setup(struct net_device *dev) 1364 { 1365 dev->netdev_ops = &ip6_tnl_netdev_ops; 1366 dev->destructor = ip6_dev_free; 1367 1368 dev->type = ARPHRD_TUNNEL6; 1369 dev->hard_header_len = LL_MAX_HEADER + sizeof (struct ipv6hdr); 1370 dev->mtu = ETH_DATA_LEN - sizeof (struct ipv6hdr); 1371 dev->flags |= IFF_NOARP; 1372 dev->addr_len = sizeof(struct in6_addr); 1373 dev->features |= NETIF_F_NETNS_LOCAL; 1374 } 1375 1376 1377 /** 1378 * ip6_tnl_dev_init_gen - general initializer for all tunnel devices 1379 * @dev: virtual device associated with tunnel 1380 **/ 1381 1382 static inline int 1383 ip6_tnl_dev_init_gen(struct net_device *dev) 1384 { 1385 struct ip6_tnl *t = netdev_priv(dev); 1386 1387 t->dev = dev; 1388 strcpy(t->parms.name, dev->name); 1389 dev->tstats = alloc_percpu(struct pcpu_tstats); 1390 if (!dev->tstats) 1391 return -ENOMEM; 1392 return 0; 1393 } 1394 1395 /** 1396 * ip6_tnl_dev_init - initializer for all non fallback tunnel devices 1397 * @dev: virtual device associated with tunnel 1398 **/ 1399 1400 static int ip6_tnl_dev_init(struct net_device *dev) 1401 { 1402 struct ip6_tnl *t = netdev_priv(dev); 1403 int err = ip6_tnl_dev_init_gen(dev); 1404 1405 if (err) 1406 return err; 1407 ip6_tnl_link_config(t); 1408 return 0; 1409 } 1410 1411 /** 1412 * ip6_fb_tnl_dev_init - initializer for fallback tunnel device 1413 * @dev: fallback device 1414 * 1415 * Return: 0 1416 **/ 1417 1418 static int __net_init ip6_fb_tnl_dev_init(struct net_device *dev) 1419 { 1420 struct ip6_tnl *t = netdev_priv(dev); 1421 struct net *net = dev_net(dev); 1422 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1423 int err = ip6_tnl_dev_init_gen(dev); 1424 1425 if (err) 1426 return err; 1427 1428 t->parms.proto = IPPROTO_IPV6; 1429 dev_hold(dev); 1430 rcu_assign_pointer(ip6n->tnls_wc[0], t); 1431 return 0; 1432 } 1433 1434 static struct xfrm6_tunnel ip4ip6_handler __read_mostly = { 1435 .handler = ip4ip6_rcv, 1436 .err_handler = ip4ip6_err, 1437 .priority = 1, 1438 }; 1439 1440 static struct xfrm6_tunnel ip6ip6_handler __read_mostly = { 1441 .handler = ip6ip6_rcv, 1442 .err_handler = ip6ip6_err, 1443 .priority = 1, 1444 }; 1445 1446 static void __net_exit ip6_tnl_destroy_tunnels(struct ip6_tnl_net *ip6n) 1447 { 1448 int h; 1449 struct ip6_tnl *t; 1450 LIST_HEAD(list); 1451 1452 for (h = 0; h < HASH_SIZE; h++) { 1453 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1454 while (t != NULL) { 1455 unregister_netdevice_queue(t->dev, &list); 1456 t = rtnl_dereference(t->next); 1457 } 1458 } 1459 1460 t = rtnl_dereference(ip6n->tnls_wc[0]); 1461 unregister_netdevice_queue(t->dev, &list); 1462 unregister_netdevice_many(&list); 1463 } 1464 1465 static int __net_init ip6_tnl_init_net(struct net *net) 1466 { 1467 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1468 int err; 1469 1470 ip6n->tnls[0] = ip6n->tnls_wc; 1471 ip6n->tnls[1] = ip6n->tnls_r_l; 1472 1473 err = -ENOMEM; 1474 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6tnl0", 1475 ip6_tnl_dev_setup); 1476 1477 if (!ip6n->fb_tnl_dev) 1478 goto err_alloc_dev; 1479 dev_net_set(ip6n->fb_tnl_dev, net); 1480 1481 err = ip6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1482 if (err < 0) 1483 goto err_register; 1484 1485 err = register_netdev(ip6n->fb_tnl_dev); 1486 if (err < 0) 1487 goto err_register; 1488 return 0; 1489 1490 err_register: 1491 ip6_dev_free(ip6n->fb_tnl_dev); 1492 err_alloc_dev: 1493 return err; 1494 } 1495 1496 static void __net_exit ip6_tnl_exit_net(struct net *net) 1497 { 1498 struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id); 1499 1500 rtnl_lock(); 1501 ip6_tnl_destroy_tunnels(ip6n); 1502 rtnl_unlock(); 1503 } 1504 1505 static struct pernet_operations ip6_tnl_net_ops = { 1506 .init = ip6_tnl_init_net, 1507 .exit = ip6_tnl_exit_net, 1508 .id = &ip6_tnl_net_id, 1509 .size = sizeof(struct ip6_tnl_net), 1510 }; 1511 1512 /** 1513 * ip6_tunnel_init - register protocol and reserve needed resources 1514 * 1515 * Return: 0 on success 1516 **/ 1517 1518 static int __init ip6_tunnel_init(void) 1519 { 1520 int err; 1521 1522 err = register_pernet_device(&ip6_tnl_net_ops); 1523 if (err < 0) 1524 goto out_pernet; 1525 1526 err = xfrm6_tunnel_register(&ip4ip6_handler, AF_INET); 1527 if (err < 0) { 1528 printk(KERN_ERR "ip6_tunnel init: can't register ip4ip6\n"); 1529 goto out_ip4ip6; 1530 } 1531 1532 err = xfrm6_tunnel_register(&ip6ip6_handler, AF_INET6); 1533 if (err < 0) { 1534 printk(KERN_ERR "ip6_tunnel init: can't register ip6ip6\n"); 1535 goto out_ip6ip6; 1536 } 1537 1538 return 0; 1539 1540 out_ip6ip6: 1541 xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET); 1542 out_ip4ip6: 1543 unregister_pernet_device(&ip6_tnl_net_ops); 1544 out_pernet: 1545 return err; 1546 } 1547 1548 /** 1549 * ip6_tunnel_cleanup - free resources and unregister protocol 1550 **/ 1551 1552 static void __exit ip6_tunnel_cleanup(void) 1553 { 1554 if (xfrm6_tunnel_deregister(&ip4ip6_handler, AF_INET)) 1555 printk(KERN_INFO "ip6_tunnel close: can't deregister ip4ip6\n"); 1556 1557 if (xfrm6_tunnel_deregister(&ip6ip6_handler, AF_INET6)) 1558 printk(KERN_INFO "ip6_tunnel close: can't deregister ip6ip6\n"); 1559 1560 unregister_pernet_device(&ip6_tnl_net_ops); 1561 } 1562 1563 module_init(ip6_tunnel_init); 1564 module_exit(ip6_tunnel_cleanup); 1565