1 /* 2 * IPv6 virtual tunneling interface 3 * 4 * Copyright (C) 2013 secunet Security Networks AG 5 * 6 * Author: 7 * Steffen Klassert <steffen.klassert@secunet.com> 8 * 9 * Based on: 10 * net/ipv6/ip6_tunnel.c 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; either version 15 * 2 of the License, or (at your option) any later version. 16 */ 17 18 #include <linux/module.h> 19 #include <linux/capability.h> 20 #include <linux/errno.h> 21 #include <linux/types.h> 22 #include <linux/sockios.h> 23 #include <linux/icmp.h> 24 #include <linux/if.h> 25 #include <linux/in.h> 26 #include <linux/ip.h> 27 #include <linux/net.h> 28 #include <linux/in6.h> 29 #include <linux/netdevice.h> 30 #include <linux/if_arp.h> 31 #include <linux/icmpv6.h> 32 #include <linux/init.h> 33 #include <linux/route.h> 34 #include <linux/rtnetlink.h> 35 #include <linux/netfilter_ipv6.h> 36 #include <linux/slab.h> 37 #include <linux/hash.h> 38 39 #include <linux/uaccess.h> 40 #include <linux/atomic.h> 41 42 #include <net/icmp.h> 43 #include <net/ip.h> 44 #include <net/ip_tunnels.h> 45 #include <net/ipv6.h> 46 #include <net/ip6_route.h> 47 #include <net/addrconf.h> 48 #include <net/ip6_tunnel.h> 49 #include <net/xfrm.h> 50 #include <net/net_namespace.h> 51 #include <net/netns/generic.h> 52 53 #define IP6_VTI_HASH_SIZE_SHIFT 5 54 #define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT) 55 56 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 57 { 58 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 59 60 return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT); 61 } 62 63 static int vti6_dev_init(struct net_device *dev); 64 static void vti6_dev_setup(struct net_device *dev); 65 static struct rtnl_link_ops vti6_link_ops __read_mostly; 66 67 static unsigned int vti6_net_id __read_mostly; 68 struct vti6_net { 69 /* the vti6 tunnel fallback device */ 70 struct net_device *fb_tnl_dev; 71 /* lists for storing tunnels in use */ 72 struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE]; 73 struct ip6_tnl __rcu *tnls_wc[1]; 74 struct ip6_tnl __rcu **tnls[2]; 75 }; 76 77 #define for_each_vti6_tunnel_rcu(start) \ 78 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 79 80 /** 81 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses 82 * @net: network namespace 83 * @remote: the address of the tunnel exit-point 84 * @local: the address of the tunnel entry-point 85 * 86 * Return: 87 * tunnel matching given end-points if found, 88 * else fallback tunnel if its device is up, 89 * else %NULL 90 **/ 91 static struct ip6_tnl * 92 vti6_tnl_lookup(struct net *net, const struct in6_addr *remote, 93 const struct in6_addr *local) 94 { 95 unsigned int hash = HASH(remote, local); 96 struct ip6_tnl *t; 97 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 98 struct in6_addr any; 99 100 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 101 if (ipv6_addr_equal(local, &t->parms.laddr) && 102 ipv6_addr_equal(remote, &t->parms.raddr) && 103 (t->dev->flags & IFF_UP)) 104 return t; 105 } 106 107 memset(&any, 0, sizeof(any)); 108 hash = HASH(&any, local); 109 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 110 if (ipv6_addr_equal(local, &t->parms.laddr) && 111 (t->dev->flags & IFF_UP)) 112 return t; 113 } 114 115 hash = HASH(remote, &any); 116 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 117 if (ipv6_addr_equal(remote, &t->parms.raddr) && 118 (t->dev->flags & IFF_UP)) 119 return t; 120 } 121 122 t = rcu_dereference(ip6n->tnls_wc[0]); 123 if (t && (t->dev->flags & IFF_UP)) 124 return t; 125 126 return NULL; 127 } 128 129 /** 130 * vti6_tnl_bucket - get head of list matching given tunnel parameters 131 * @p: parameters containing tunnel end-points 132 * 133 * Description: 134 * vti6_tnl_bucket() returns the head of the list matching the 135 * &struct in6_addr entries laddr and raddr in @p. 136 * 137 * Return: head of IPv6 tunnel list 138 **/ 139 static struct ip6_tnl __rcu ** 140 vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p) 141 { 142 const struct in6_addr *remote = &p->raddr; 143 const struct in6_addr *local = &p->laddr; 144 unsigned int h = 0; 145 int prio = 0; 146 147 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 148 prio = 1; 149 h = HASH(remote, local); 150 } 151 return &ip6n->tnls[prio][h]; 152 } 153 154 static void 155 vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t) 156 { 157 struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms); 158 159 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 160 rcu_assign_pointer(*tp, t); 161 } 162 163 static void 164 vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t) 165 { 166 struct ip6_tnl __rcu **tp; 167 struct ip6_tnl *iter; 168 169 for (tp = vti6_tnl_bucket(ip6n, &t->parms); 170 (iter = rtnl_dereference(*tp)) != NULL; 171 tp = &iter->next) { 172 if (t == iter) { 173 rcu_assign_pointer(*tp, t->next); 174 break; 175 } 176 } 177 } 178 179 static void vti6_dev_free(struct net_device *dev) 180 { 181 free_percpu(dev->tstats); 182 free_netdev(dev); 183 } 184 185 static int vti6_tnl_create2(struct net_device *dev) 186 { 187 struct ip6_tnl *t = netdev_priv(dev); 188 struct net *net = dev_net(dev); 189 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 190 int err; 191 192 err = register_netdevice(dev); 193 if (err < 0) 194 goto out; 195 196 strcpy(t->parms.name, dev->name); 197 dev->rtnl_link_ops = &vti6_link_ops; 198 199 dev_hold(dev); 200 vti6_tnl_link(ip6n, t); 201 202 return 0; 203 204 out: 205 return err; 206 } 207 208 static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 209 { 210 struct net_device *dev; 211 struct ip6_tnl *t; 212 char name[IFNAMSIZ]; 213 int err; 214 215 if (p->name[0]) 216 strlcpy(name, p->name, IFNAMSIZ); 217 else 218 sprintf(name, "ip6_vti%%d"); 219 220 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup); 221 if (!dev) 222 goto failed; 223 224 dev_net_set(dev, net); 225 226 t = netdev_priv(dev); 227 t->parms = *p; 228 t->net = dev_net(dev); 229 230 err = vti6_tnl_create2(dev); 231 if (err < 0) 232 goto failed_free; 233 234 return t; 235 236 failed_free: 237 vti6_dev_free(dev); 238 failed: 239 return NULL; 240 } 241 242 /** 243 * vti6_locate - find or create tunnel matching given parameters 244 * @net: network namespace 245 * @p: tunnel parameters 246 * @create: != 0 if allowed to create new tunnel if no match found 247 * 248 * Description: 249 * vti6_locate() first tries to locate an existing tunnel 250 * based on @parms. If this is unsuccessful, but @create is set a new 251 * tunnel device is created and registered for use. 252 * 253 * Return: 254 * matching tunnel or NULL 255 **/ 256 static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p, 257 int create) 258 { 259 const struct in6_addr *remote = &p->raddr; 260 const struct in6_addr *local = &p->laddr; 261 struct ip6_tnl __rcu **tp; 262 struct ip6_tnl *t; 263 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 264 265 for (tp = vti6_tnl_bucket(ip6n, p); 266 (t = rtnl_dereference(*tp)) != NULL; 267 tp = &t->next) { 268 if (ipv6_addr_equal(local, &t->parms.laddr) && 269 ipv6_addr_equal(remote, &t->parms.raddr)) { 270 if (create) 271 return NULL; 272 273 return t; 274 } 275 } 276 if (!create) 277 return NULL; 278 return vti6_tnl_create(net, p); 279 } 280 281 /** 282 * vti6_dev_uninit - tunnel device uninitializer 283 * @dev: the device to be destroyed 284 * 285 * Description: 286 * vti6_dev_uninit() removes tunnel from its list 287 **/ 288 static void vti6_dev_uninit(struct net_device *dev) 289 { 290 struct ip6_tnl *t = netdev_priv(dev); 291 struct vti6_net *ip6n = net_generic(t->net, vti6_net_id); 292 293 if (dev == ip6n->fb_tnl_dev) 294 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 295 else 296 vti6_tnl_unlink(ip6n, t); 297 dev_put(dev); 298 } 299 300 static int vti6_rcv(struct sk_buff *skb) 301 { 302 struct ip6_tnl *t; 303 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 304 305 rcu_read_lock(); 306 t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr); 307 if (t) { 308 if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) { 309 rcu_read_unlock(); 310 goto discard; 311 } 312 313 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 314 rcu_read_unlock(); 315 return 0; 316 } 317 318 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 319 t->dev->stats.rx_dropped++; 320 rcu_read_unlock(); 321 goto discard; 322 } 323 324 rcu_read_unlock(); 325 326 return xfrm6_rcv_tnl(skb, t); 327 } 328 rcu_read_unlock(); 329 return -EINVAL; 330 discard: 331 kfree_skb(skb); 332 return 0; 333 } 334 335 static int vti6_rcv_cb(struct sk_buff *skb, int err) 336 { 337 unsigned short family; 338 struct net_device *dev; 339 struct pcpu_sw_netstats *tstats; 340 struct xfrm_state *x; 341 struct xfrm_mode *inner_mode; 342 struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6; 343 u32 orig_mark = skb->mark; 344 int ret; 345 346 if (!t) 347 return 1; 348 349 dev = t->dev; 350 351 if (err) { 352 dev->stats.rx_errors++; 353 dev->stats.rx_dropped++; 354 355 return 0; 356 } 357 358 x = xfrm_input_state(skb); 359 360 inner_mode = x->inner_mode; 361 362 if (x->sel.family == AF_UNSPEC) { 363 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); 364 if (inner_mode == NULL) { 365 XFRM_INC_STATS(dev_net(skb->dev), 366 LINUX_MIB_XFRMINSTATEMODEERROR); 367 return -EINVAL; 368 } 369 } 370 371 family = inner_mode->afinfo->family; 372 373 skb->mark = be32_to_cpu(t->parms.i_key); 374 ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family); 375 skb->mark = orig_mark; 376 377 if (!ret) 378 return -EPERM; 379 380 skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev))); 381 skb->dev = dev; 382 383 tstats = this_cpu_ptr(dev->tstats); 384 u64_stats_update_begin(&tstats->syncp); 385 tstats->rx_packets++; 386 tstats->rx_bytes += skb->len; 387 u64_stats_update_end(&tstats->syncp); 388 389 return 0; 390 } 391 392 /** 393 * vti6_addr_conflict - compare packet addresses to tunnel's own 394 * @t: the outgoing tunnel device 395 * @hdr: IPv6 header from the incoming packet 396 * 397 * Description: 398 * Avoid trivial tunneling loop by checking that tunnel exit-point 399 * doesn't match source of incoming packet. 400 * 401 * Return: 402 * 1 if conflict, 403 * 0 else 404 **/ 405 static inline bool 406 vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 407 { 408 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 409 } 410 411 static bool vti6_state_check(const struct xfrm_state *x, 412 const struct in6_addr *dst, 413 const struct in6_addr *src) 414 { 415 xfrm_address_t *daddr = (xfrm_address_t *)dst; 416 xfrm_address_t *saddr = (xfrm_address_t *)src; 417 418 /* if there is no transform then this tunnel is not functional. 419 * Or if the xfrm is not mode tunnel. 420 */ 421 if (!x || x->props.mode != XFRM_MODE_TUNNEL || 422 x->props.family != AF_INET6) 423 return false; 424 425 if (ipv6_addr_any(dst)) 426 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6); 427 428 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6)) 429 return false; 430 431 return true; 432 } 433 434 /** 435 * vti6_xmit - send a packet 436 * @skb: the outgoing socket buffer 437 * @dev: the outgoing tunnel device 438 * @fl: the flow informations for the xfrm_lookup 439 **/ 440 static int 441 vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) 442 { 443 struct ip6_tnl *t = netdev_priv(dev); 444 struct net_device_stats *stats = &t->dev->stats; 445 struct dst_entry *dst = skb_dst(skb); 446 struct net_device *tdev; 447 struct xfrm_state *x; 448 int err = -1; 449 int mtu; 450 451 if (!dst) 452 goto tx_err_link_failure; 453 454 dst_hold(dst); 455 dst = xfrm_lookup(t->net, dst, fl, NULL, 0); 456 if (IS_ERR(dst)) { 457 err = PTR_ERR(dst); 458 dst = NULL; 459 goto tx_err_link_failure; 460 } 461 462 x = dst->xfrm; 463 if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr)) 464 goto tx_err_link_failure; 465 466 if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr, 467 (const struct in6_addr *)&x->id.daddr)) 468 goto tx_err_link_failure; 469 470 tdev = dst->dev; 471 472 if (tdev == dev) { 473 stats->collisions++; 474 net_warn_ratelimited("%s: Local routing loop detected!\n", 475 t->parms.name); 476 goto tx_err_dst_release; 477 } 478 479 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 480 skb_dst_set(skb, dst); 481 skb->dev = skb_dst(skb)->dev; 482 483 mtu = dst_mtu(dst); 484 if (!skb->ignore_df && skb->len > mtu) { 485 skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu); 486 487 if (skb->protocol == htons(ETH_P_IPV6)) 488 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 489 else 490 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 491 htonl(mtu)); 492 493 return -EMSGSIZE; 494 } 495 496 err = dst_output(t->net, skb->sk, skb); 497 if (net_xmit_eval(err) == 0) { 498 struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats); 499 500 u64_stats_update_begin(&tstats->syncp); 501 tstats->tx_bytes += skb->len; 502 tstats->tx_packets++; 503 u64_stats_update_end(&tstats->syncp); 504 } else { 505 stats->tx_errors++; 506 stats->tx_aborted_errors++; 507 } 508 509 return 0; 510 tx_err_link_failure: 511 stats->tx_carrier_errors++; 512 dst_link_failure(skb); 513 tx_err_dst_release: 514 dst_release(dst); 515 return err; 516 } 517 518 static netdev_tx_t 519 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 520 { 521 struct ip6_tnl *t = netdev_priv(dev); 522 struct net_device_stats *stats = &t->dev->stats; 523 struct ipv6hdr *ipv6h; 524 struct flowi fl; 525 int ret; 526 527 memset(&fl, 0, sizeof(fl)); 528 529 switch (skb->protocol) { 530 case htons(ETH_P_IPV6): 531 ipv6h = ipv6_hdr(skb); 532 533 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 534 vti6_addr_conflict(t, ipv6h)) 535 goto tx_err; 536 537 xfrm_decode_session(skb, &fl, AF_INET6); 538 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 539 break; 540 case htons(ETH_P_IP): 541 xfrm_decode_session(skb, &fl, AF_INET); 542 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 543 break; 544 default: 545 goto tx_err; 546 } 547 548 /* override mark with tunnel output key */ 549 fl.flowi_mark = be32_to_cpu(t->parms.o_key); 550 551 ret = vti6_xmit(skb, dev, &fl); 552 if (ret < 0) 553 goto tx_err; 554 555 return NETDEV_TX_OK; 556 557 tx_err: 558 stats->tx_errors++; 559 stats->tx_dropped++; 560 kfree_skb(skb); 561 return NETDEV_TX_OK; 562 } 563 564 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 565 u8 type, u8 code, int offset, __be32 info) 566 { 567 __be32 spi; 568 __u32 mark; 569 struct xfrm_state *x; 570 struct ip6_tnl *t; 571 struct ip_esp_hdr *esph; 572 struct ip_auth_hdr *ah; 573 struct ip_comp_hdr *ipch; 574 struct net *net = dev_net(skb->dev); 575 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 576 int protocol = iph->nexthdr; 577 578 t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr); 579 if (!t) 580 return -1; 581 582 mark = be32_to_cpu(t->parms.o_key); 583 584 switch (protocol) { 585 case IPPROTO_ESP: 586 esph = (struct ip_esp_hdr *)(skb->data + offset); 587 spi = esph->spi; 588 break; 589 case IPPROTO_AH: 590 ah = (struct ip_auth_hdr *)(skb->data + offset); 591 spi = ah->spi; 592 break; 593 case IPPROTO_COMP: 594 ipch = (struct ip_comp_hdr *)(skb->data + offset); 595 spi = htonl(ntohs(ipch->cpi)); 596 break; 597 default: 598 return 0; 599 } 600 601 if (type != ICMPV6_PKT_TOOBIG && 602 type != NDISC_REDIRECT) 603 return 0; 604 605 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, 606 spi, protocol, AF_INET6); 607 if (!x) 608 return 0; 609 610 if (type == NDISC_REDIRECT) 611 ip6_redirect(skb, net, skb->dev->ifindex, 0, 612 sock_net_uid(net, NULL)); 613 else 614 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 615 xfrm_state_put(x); 616 617 return 0; 618 } 619 620 static void vti6_link_config(struct ip6_tnl *t) 621 { 622 struct net_device *dev = t->dev; 623 struct __ip6_tnl_parm *p = &t->parms; 624 625 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 626 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 627 628 p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV | 629 IP6_TNL_F_CAP_PER_PACKET); 630 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 631 632 if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV) 633 dev->flags |= IFF_POINTOPOINT; 634 else 635 dev->flags &= ~IFF_POINTOPOINT; 636 } 637 638 /** 639 * vti6_tnl_change - update the tunnel parameters 640 * @t: tunnel to be changed 641 * @p: tunnel configuration parameters 642 * 643 * Description: 644 * vti6_tnl_change() updates the tunnel parameters 645 **/ 646 static int 647 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p) 648 { 649 t->parms.laddr = p->laddr; 650 t->parms.raddr = p->raddr; 651 t->parms.link = p->link; 652 t->parms.i_key = p->i_key; 653 t->parms.o_key = p->o_key; 654 t->parms.proto = p->proto; 655 dst_cache_reset(&t->dst_cache); 656 vti6_link_config(t); 657 return 0; 658 } 659 660 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p) 661 { 662 struct net *net = dev_net(t->dev); 663 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 664 int err; 665 666 vti6_tnl_unlink(ip6n, t); 667 synchronize_net(); 668 err = vti6_tnl_change(t, p); 669 vti6_tnl_link(ip6n, t); 670 netdev_state_change(t->dev); 671 return err; 672 } 673 674 static void 675 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u) 676 { 677 p->laddr = u->laddr; 678 p->raddr = u->raddr; 679 p->link = u->link; 680 p->i_key = u->i_key; 681 p->o_key = u->o_key; 682 p->proto = u->proto; 683 684 memcpy(p->name, u->name, sizeof(u->name)); 685 } 686 687 static void 688 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p) 689 { 690 u->laddr = p->laddr; 691 u->raddr = p->raddr; 692 u->link = p->link; 693 u->i_key = p->i_key; 694 u->o_key = p->o_key; 695 u->proto = p->proto; 696 697 memcpy(u->name, p->name, sizeof(u->name)); 698 } 699 700 /** 701 * vti6_tnl_ioctl - configure vti6 tunnels from userspace 702 * @dev: virtual device associated with tunnel 703 * @ifr: parameters passed from userspace 704 * @cmd: command to be performed 705 * 706 * Description: 707 * vti6_ioctl() is used for managing vti6 tunnels 708 * from userspace. 709 * 710 * The possible commands are the following: 711 * %SIOCGETTUNNEL: get tunnel parameters for device 712 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 713 * %SIOCCHGTUNNEL: change tunnel parameters to those given 714 * %SIOCDELTUNNEL: delete tunnel 715 * 716 * The fallback device "ip6_vti0", created during module 717 * initialization, can be used for creating other tunnel devices. 718 * 719 * Return: 720 * 0 on success, 721 * %-EFAULT if unable to copy data to or from userspace, 722 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 723 * %-EINVAL if passed tunnel parameters are invalid, 724 * %-EEXIST if changing a tunnel's parameters would cause a conflict 725 * %-ENODEV if attempting to change or delete a nonexisting device 726 **/ 727 static int 728 vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 729 { 730 int err = 0; 731 struct ip6_tnl_parm2 p; 732 struct __ip6_tnl_parm p1; 733 struct ip6_tnl *t = NULL; 734 struct net *net = dev_net(dev); 735 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 736 737 switch (cmd) { 738 case SIOCGETTUNNEL: 739 if (dev == ip6n->fb_tnl_dev) { 740 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 741 err = -EFAULT; 742 break; 743 } 744 vti6_parm_from_user(&p1, &p); 745 t = vti6_locate(net, &p1, 0); 746 } else { 747 memset(&p, 0, sizeof(p)); 748 } 749 if (!t) 750 t = netdev_priv(dev); 751 vti6_parm_to_user(&p, &t->parms); 752 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 753 err = -EFAULT; 754 break; 755 case SIOCADDTUNNEL: 756 case SIOCCHGTUNNEL: 757 err = -EPERM; 758 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 759 break; 760 err = -EFAULT; 761 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 762 break; 763 err = -EINVAL; 764 if (p.proto != IPPROTO_IPV6 && p.proto != 0) 765 break; 766 vti6_parm_from_user(&p1, &p); 767 t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL); 768 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 769 if (t) { 770 if (t->dev != dev) { 771 err = -EEXIST; 772 break; 773 } 774 } else 775 t = netdev_priv(dev); 776 777 err = vti6_update(t, &p1); 778 } 779 if (t) { 780 err = 0; 781 vti6_parm_to_user(&p, &t->parms); 782 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 783 err = -EFAULT; 784 785 } else 786 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 787 break; 788 case SIOCDELTUNNEL: 789 err = -EPERM; 790 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 791 break; 792 793 if (dev == ip6n->fb_tnl_dev) { 794 err = -EFAULT; 795 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 796 break; 797 err = -ENOENT; 798 vti6_parm_from_user(&p1, &p); 799 t = vti6_locate(net, &p1, 0); 800 if (!t) 801 break; 802 err = -EPERM; 803 if (t->dev == ip6n->fb_tnl_dev) 804 break; 805 dev = t->dev; 806 } 807 err = 0; 808 unregister_netdevice(dev); 809 break; 810 default: 811 err = -EINVAL; 812 } 813 return err; 814 } 815 816 static const struct net_device_ops vti6_netdev_ops = { 817 .ndo_init = vti6_dev_init, 818 .ndo_uninit = vti6_dev_uninit, 819 .ndo_start_xmit = vti6_tnl_xmit, 820 .ndo_do_ioctl = vti6_ioctl, 821 .ndo_get_stats64 = ip_tunnel_get_stats64, 822 .ndo_get_iflink = ip6_tnl_get_iflink, 823 }; 824 825 /** 826 * vti6_dev_setup - setup virtual tunnel device 827 * @dev: virtual device associated with tunnel 828 * 829 * Description: 830 * Initialize function pointers and device parameters 831 **/ 832 static void vti6_dev_setup(struct net_device *dev) 833 { 834 dev->netdev_ops = &vti6_netdev_ops; 835 dev->destructor = vti6_dev_free; 836 837 dev->type = ARPHRD_TUNNEL6; 838 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr); 839 dev->mtu = ETH_DATA_LEN; 840 dev->min_mtu = IPV6_MIN_MTU; 841 dev->max_mtu = IP_MAX_MTU; 842 dev->flags |= IFF_NOARP; 843 dev->addr_len = sizeof(struct in6_addr); 844 netif_keep_dst(dev); 845 } 846 847 /** 848 * vti6_dev_init_gen - general initializer for all tunnel devices 849 * @dev: virtual device associated with tunnel 850 **/ 851 static inline int vti6_dev_init_gen(struct net_device *dev) 852 { 853 struct ip6_tnl *t = netdev_priv(dev); 854 855 t->dev = dev; 856 t->net = dev_net(dev); 857 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 858 if (!dev->tstats) 859 return -ENOMEM; 860 return 0; 861 } 862 863 /** 864 * vti6_dev_init - initializer for all non fallback tunnel devices 865 * @dev: virtual device associated with tunnel 866 **/ 867 static int vti6_dev_init(struct net_device *dev) 868 { 869 struct ip6_tnl *t = netdev_priv(dev); 870 int err = vti6_dev_init_gen(dev); 871 872 if (err) 873 return err; 874 vti6_link_config(t); 875 return 0; 876 } 877 878 /** 879 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device 880 * @dev: fallback device 881 * 882 * Return: 0 883 **/ 884 static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev) 885 { 886 struct ip6_tnl *t = netdev_priv(dev); 887 struct net *net = dev_net(dev); 888 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 889 890 t->parms.proto = IPPROTO_IPV6; 891 dev_hold(dev); 892 893 rcu_assign_pointer(ip6n->tnls_wc[0], t); 894 return 0; 895 } 896 897 static int vti6_validate(struct nlattr *tb[], struct nlattr *data[]) 898 { 899 return 0; 900 } 901 902 static void vti6_netlink_parms(struct nlattr *data[], 903 struct __ip6_tnl_parm *parms) 904 { 905 memset(parms, 0, sizeof(*parms)); 906 907 if (!data) 908 return; 909 910 if (data[IFLA_VTI_LINK]) 911 parms->link = nla_get_u32(data[IFLA_VTI_LINK]); 912 913 if (data[IFLA_VTI_LOCAL]) 914 parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]); 915 916 if (data[IFLA_VTI_REMOTE]) 917 parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]); 918 919 if (data[IFLA_VTI_IKEY]) 920 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); 921 922 if (data[IFLA_VTI_OKEY]) 923 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); 924 } 925 926 static int vti6_newlink(struct net *src_net, struct net_device *dev, 927 struct nlattr *tb[], struct nlattr *data[]) 928 { 929 struct net *net = dev_net(dev); 930 struct ip6_tnl *nt; 931 932 nt = netdev_priv(dev); 933 vti6_netlink_parms(data, &nt->parms); 934 935 nt->parms.proto = IPPROTO_IPV6; 936 937 if (vti6_locate(net, &nt->parms, 0)) 938 return -EEXIST; 939 940 return vti6_tnl_create2(dev); 941 } 942 943 static void vti6_dellink(struct net_device *dev, struct list_head *head) 944 { 945 struct net *net = dev_net(dev); 946 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 947 948 if (dev != ip6n->fb_tnl_dev) 949 unregister_netdevice_queue(dev, head); 950 } 951 952 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[], 953 struct nlattr *data[]) 954 { 955 struct ip6_tnl *t; 956 struct __ip6_tnl_parm p; 957 struct net *net = dev_net(dev); 958 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 959 960 if (dev == ip6n->fb_tnl_dev) 961 return -EINVAL; 962 963 vti6_netlink_parms(data, &p); 964 965 t = vti6_locate(net, &p, 0); 966 967 if (t) { 968 if (t->dev != dev) 969 return -EEXIST; 970 } else 971 t = netdev_priv(dev); 972 973 return vti6_update(t, &p); 974 } 975 976 static size_t vti6_get_size(const struct net_device *dev) 977 { 978 return 979 /* IFLA_VTI_LINK */ 980 nla_total_size(4) + 981 /* IFLA_VTI_LOCAL */ 982 nla_total_size(sizeof(struct in6_addr)) + 983 /* IFLA_VTI_REMOTE */ 984 nla_total_size(sizeof(struct in6_addr)) + 985 /* IFLA_VTI_IKEY */ 986 nla_total_size(4) + 987 /* IFLA_VTI_OKEY */ 988 nla_total_size(4) + 989 0; 990 } 991 992 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev) 993 { 994 struct ip6_tnl *tunnel = netdev_priv(dev); 995 struct __ip6_tnl_parm *parm = &tunnel->parms; 996 997 if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) || 998 nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) || 999 nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) || 1000 nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) || 1001 nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key)) 1002 goto nla_put_failure; 1003 return 0; 1004 1005 nla_put_failure: 1006 return -EMSGSIZE; 1007 } 1008 1009 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = { 1010 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 1011 [IFLA_VTI_LOCAL] = { .len = sizeof(struct in6_addr) }, 1012 [IFLA_VTI_REMOTE] = { .len = sizeof(struct in6_addr) }, 1013 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 1014 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 1015 }; 1016 1017 static struct rtnl_link_ops vti6_link_ops __read_mostly = { 1018 .kind = "vti6", 1019 .maxtype = IFLA_VTI_MAX, 1020 .policy = vti6_policy, 1021 .priv_size = sizeof(struct ip6_tnl), 1022 .setup = vti6_dev_setup, 1023 .validate = vti6_validate, 1024 .newlink = vti6_newlink, 1025 .dellink = vti6_dellink, 1026 .changelink = vti6_changelink, 1027 .get_size = vti6_get_size, 1028 .fill_info = vti6_fill_info, 1029 .get_link_net = ip6_tnl_get_link_net, 1030 }; 1031 1032 static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n) 1033 { 1034 int h; 1035 struct ip6_tnl *t; 1036 LIST_HEAD(list); 1037 1038 for (h = 0; h < IP6_VTI_HASH_SIZE; h++) { 1039 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1040 while (t) { 1041 unregister_netdevice_queue(t->dev, &list); 1042 t = rtnl_dereference(t->next); 1043 } 1044 } 1045 1046 t = rtnl_dereference(ip6n->tnls_wc[0]); 1047 unregister_netdevice_queue(t->dev, &list); 1048 unregister_netdevice_many(&list); 1049 } 1050 1051 static int __net_init vti6_init_net(struct net *net) 1052 { 1053 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1054 struct ip6_tnl *t = NULL; 1055 int err; 1056 1057 ip6n->tnls[0] = ip6n->tnls_wc; 1058 ip6n->tnls[1] = ip6n->tnls_r_l; 1059 1060 err = -ENOMEM; 1061 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0", 1062 NET_NAME_UNKNOWN, vti6_dev_setup); 1063 1064 if (!ip6n->fb_tnl_dev) 1065 goto err_alloc_dev; 1066 dev_net_set(ip6n->fb_tnl_dev, net); 1067 ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops; 1068 1069 err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1070 if (err < 0) 1071 goto err_register; 1072 1073 err = register_netdev(ip6n->fb_tnl_dev); 1074 if (err < 0) 1075 goto err_register; 1076 1077 t = netdev_priv(ip6n->fb_tnl_dev); 1078 1079 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1080 return 0; 1081 1082 err_register: 1083 vti6_dev_free(ip6n->fb_tnl_dev); 1084 err_alloc_dev: 1085 return err; 1086 } 1087 1088 static void __net_exit vti6_exit_net(struct net *net) 1089 { 1090 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1091 1092 rtnl_lock(); 1093 vti6_destroy_tunnels(ip6n); 1094 rtnl_unlock(); 1095 } 1096 1097 static struct pernet_operations vti6_net_ops = { 1098 .init = vti6_init_net, 1099 .exit = vti6_exit_net, 1100 .id = &vti6_net_id, 1101 .size = sizeof(struct vti6_net), 1102 }; 1103 1104 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = { 1105 .handler = vti6_rcv, 1106 .cb_handler = vti6_rcv_cb, 1107 .err_handler = vti6_err, 1108 .priority = 100, 1109 }; 1110 1111 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = { 1112 .handler = vti6_rcv, 1113 .cb_handler = vti6_rcv_cb, 1114 .err_handler = vti6_err, 1115 .priority = 100, 1116 }; 1117 1118 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = { 1119 .handler = vti6_rcv, 1120 .cb_handler = vti6_rcv_cb, 1121 .err_handler = vti6_err, 1122 .priority = 100, 1123 }; 1124 1125 static bool is_vti6_tunnel(const struct net_device *dev) 1126 { 1127 return dev->netdev_ops == &vti6_netdev_ops; 1128 } 1129 1130 static int vti6_device_event(struct notifier_block *unused, 1131 unsigned long event, void *ptr) 1132 { 1133 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1134 struct ip6_tnl *t = netdev_priv(dev); 1135 1136 if (!is_vti6_tunnel(dev)) 1137 return NOTIFY_DONE; 1138 1139 switch (event) { 1140 case NETDEV_DOWN: 1141 if (!net_eq(t->net, dev_net(dev))) 1142 xfrm_garbage_collect(t->net); 1143 break; 1144 } 1145 return NOTIFY_DONE; 1146 } 1147 1148 static struct notifier_block vti6_notifier_block __read_mostly = { 1149 .notifier_call = vti6_device_event, 1150 }; 1151 1152 /** 1153 * vti6_tunnel_init - register protocol and reserve needed resources 1154 * 1155 * Return: 0 on success 1156 **/ 1157 static int __init vti6_tunnel_init(void) 1158 { 1159 const char *msg; 1160 int err; 1161 1162 register_netdevice_notifier(&vti6_notifier_block); 1163 1164 msg = "tunnel device"; 1165 err = register_pernet_device(&vti6_net_ops); 1166 if (err < 0) 1167 goto pernet_dev_failed; 1168 1169 msg = "tunnel protocols"; 1170 err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP); 1171 if (err < 0) 1172 goto xfrm_proto_esp_failed; 1173 err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH); 1174 if (err < 0) 1175 goto xfrm_proto_ah_failed; 1176 err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP); 1177 if (err < 0) 1178 goto xfrm_proto_comp_failed; 1179 1180 msg = "netlink interface"; 1181 err = rtnl_link_register(&vti6_link_ops); 1182 if (err < 0) 1183 goto rtnl_link_failed; 1184 1185 return 0; 1186 1187 rtnl_link_failed: 1188 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1189 xfrm_proto_comp_failed: 1190 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1191 xfrm_proto_ah_failed: 1192 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1193 xfrm_proto_esp_failed: 1194 unregister_pernet_device(&vti6_net_ops); 1195 pernet_dev_failed: 1196 unregister_netdevice_notifier(&vti6_notifier_block); 1197 pr_err("vti6 init: failed to register %s\n", msg); 1198 return err; 1199 } 1200 1201 /** 1202 * vti6_tunnel_cleanup - free resources and unregister protocol 1203 **/ 1204 static void __exit vti6_tunnel_cleanup(void) 1205 { 1206 rtnl_link_unregister(&vti6_link_ops); 1207 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1208 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1209 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1210 unregister_pernet_device(&vti6_net_ops); 1211 unregister_netdevice_notifier(&vti6_notifier_block); 1212 } 1213 1214 module_init(vti6_tunnel_init); 1215 module_exit(vti6_tunnel_cleanup); 1216 MODULE_LICENSE("GPL"); 1217 MODULE_ALIAS_RTNL_LINK("vti6"); 1218 MODULE_ALIAS_NETDEV("ip6_vti0"); 1219 MODULE_AUTHOR("Steffen Klassert"); 1220 MODULE_DESCRIPTION("IPv6 virtual tunnel interface"); 1221