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 #include <linux/etherdevice.h> 53 54 #define IP6_VTI_HASH_SIZE_SHIFT 5 55 #define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT) 56 57 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 58 { 59 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 60 61 return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT); 62 } 63 64 static int vti6_dev_init(struct net_device *dev); 65 static void vti6_dev_setup(struct net_device *dev); 66 static struct rtnl_link_ops vti6_link_ops __read_mostly; 67 68 static unsigned int vti6_net_id __read_mostly; 69 struct vti6_net { 70 /* the vti6 tunnel fallback device */ 71 struct net_device *fb_tnl_dev; 72 /* lists for storing tunnels in use */ 73 struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE]; 74 struct ip6_tnl __rcu *tnls_wc[1]; 75 struct ip6_tnl __rcu **tnls[2]; 76 }; 77 78 #define for_each_vti6_tunnel_rcu(start) \ 79 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 80 81 /** 82 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses 83 * @net: network namespace 84 * @remote: the address of the tunnel exit-point 85 * @local: the address of the tunnel entry-point 86 * 87 * Return: 88 * tunnel matching given end-points if found, 89 * else fallback tunnel if its device is up, 90 * else %NULL 91 **/ 92 static struct ip6_tnl * 93 vti6_tnl_lookup(struct net *net, const struct in6_addr *remote, 94 const struct in6_addr *local) 95 { 96 unsigned int hash = HASH(remote, local); 97 struct ip6_tnl *t; 98 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 99 struct in6_addr any; 100 101 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 102 if (ipv6_addr_equal(local, &t->parms.laddr) && 103 ipv6_addr_equal(remote, &t->parms.raddr) && 104 (t->dev->flags & IFF_UP)) 105 return t; 106 } 107 108 memset(&any, 0, sizeof(any)); 109 hash = HASH(&any, local); 110 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 111 if (ipv6_addr_equal(local, &t->parms.laddr) && 112 (t->dev->flags & IFF_UP)) 113 return t; 114 } 115 116 hash = HASH(remote, &any); 117 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 118 if (ipv6_addr_equal(remote, &t->parms.raddr) && 119 (t->dev->flags & IFF_UP)) 120 return t; 121 } 122 123 t = rcu_dereference(ip6n->tnls_wc[0]); 124 if (t && (t->dev->flags & IFF_UP)) 125 return t; 126 127 return NULL; 128 } 129 130 /** 131 * vti6_tnl_bucket - get head of list matching given tunnel parameters 132 * @p: parameters containing tunnel end-points 133 * 134 * Description: 135 * vti6_tnl_bucket() returns the head of the list matching the 136 * &struct in6_addr entries laddr and raddr in @p. 137 * 138 * Return: head of IPv6 tunnel list 139 **/ 140 static struct ip6_tnl __rcu ** 141 vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p) 142 { 143 const struct in6_addr *remote = &p->raddr; 144 const struct in6_addr *local = &p->laddr; 145 unsigned int h = 0; 146 int prio = 0; 147 148 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 149 prio = 1; 150 h = HASH(remote, local); 151 } 152 return &ip6n->tnls[prio][h]; 153 } 154 155 static void 156 vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t) 157 { 158 struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms); 159 160 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 161 rcu_assign_pointer(*tp, t); 162 } 163 164 static void 165 vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t) 166 { 167 struct ip6_tnl __rcu **tp; 168 struct ip6_tnl *iter; 169 170 for (tp = vti6_tnl_bucket(ip6n, &t->parms); 171 (iter = rtnl_dereference(*tp)) != NULL; 172 tp = &iter->next) { 173 if (t == iter) { 174 rcu_assign_pointer(*tp, t->next); 175 break; 176 } 177 } 178 } 179 180 static void vti6_dev_free(struct net_device *dev) 181 { 182 free_percpu(dev->tstats); 183 free_netdev(dev); 184 } 185 186 static int vti6_tnl_create2(struct net_device *dev) 187 { 188 struct ip6_tnl *t = netdev_priv(dev); 189 struct net *net = dev_net(dev); 190 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 191 int err; 192 193 dev->rtnl_link_ops = &vti6_link_ops; 194 err = register_netdevice(dev); 195 if (err < 0) 196 goto out; 197 198 strcpy(t->parms.name, dev->name); 199 200 dev_hold(dev); 201 vti6_tnl_link(ip6n, t); 202 203 return 0; 204 205 out: 206 return err; 207 } 208 209 static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 210 { 211 struct net_device *dev; 212 struct ip6_tnl *t; 213 char name[IFNAMSIZ]; 214 int err; 215 216 if (p->name[0]) 217 strlcpy(name, p->name, IFNAMSIZ); 218 else 219 sprintf(name, "ip6_vti%%d"); 220 221 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup); 222 if (!dev) 223 goto failed; 224 225 dev_net_set(dev, net); 226 227 t = netdev_priv(dev); 228 t->parms = *p; 229 t->net = dev_net(dev); 230 231 err = vti6_tnl_create2(dev); 232 if (err < 0) 233 goto failed_free; 234 235 return t; 236 237 failed_free: 238 vti6_dev_free(dev); 239 failed: 240 return NULL; 241 } 242 243 /** 244 * vti6_locate - find or create tunnel matching given parameters 245 * @net: network namespace 246 * @p: tunnel parameters 247 * @create: != 0 if allowed to create new tunnel if no match found 248 * 249 * Description: 250 * vti6_locate() first tries to locate an existing tunnel 251 * based on @parms. If this is unsuccessful, but @create is set a new 252 * tunnel device is created and registered for use. 253 * 254 * Return: 255 * matching tunnel or NULL 256 **/ 257 static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p, 258 int create) 259 { 260 const struct in6_addr *remote = &p->raddr; 261 const struct in6_addr *local = &p->laddr; 262 struct ip6_tnl __rcu **tp; 263 struct ip6_tnl *t; 264 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 265 266 for (tp = vti6_tnl_bucket(ip6n, p); 267 (t = rtnl_dereference(*tp)) != NULL; 268 tp = &t->next) { 269 if (ipv6_addr_equal(local, &t->parms.laddr) && 270 ipv6_addr_equal(remote, &t->parms.raddr)) { 271 if (create) 272 return NULL; 273 274 return t; 275 } 276 } 277 if (!create) 278 return NULL; 279 return vti6_tnl_create(net, p); 280 } 281 282 /** 283 * vti6_dev_uninit - tunnel device uninitializer 284 * @dev: the device to be destroyed 285 * 286 * Description: 287 * vti6_dev_uninit() removes tunnel from its list 288 **/ 289 static void vti6_dev_uninit(struct net_device *dev) 290 { 291 struct ip6_tnl *t = netdev_priv(dev); 292 struct vti6_net *ip6n = net_generic(t->net, vti6_net_id); 293 294 if (dev == ip6n->fb_tnl_dev) 295 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 296 else 297 vti6_tnl_unlink(ip6n, t); 298 dev_put(dev); 299 } 300 301 static int vti6_rcv(struct sk_buff *skb) 302 { 303 struct ip6_tnl *t; 304 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 305 306 rcu_read_lock(); 307 t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr); 308 if (t) { 309 if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) { 310 rcu_read_unlock(); 311 goto discard; 312 } 313 314 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 315 rcu_read_unlock(); 316 return 0; 317 } 318 319 if (!ip6_tnl_rcv_ctl(t, &ipv6h->daddr, &ipv6h->saddr)) { 320 t->dev->stats.rx_dropped++; 321 rcu_read_unlock(); 322 goto discard; 323 } 324 325 rcu_read_unlock(); 326 327 return xfrm6_rcv_tnl(skb, t); 328 } 329 rcu_read_unlock(); 330 return -EINVAL; 331 discard: 332 kfree_skb(skb); 333 return 0; 334 } 335 336 static int vti6_rcv_cb(struct sk_buff *skb, int err) 337 { 338 unsigned short family; 339 struct net_device *dev; 340 struct pcpu_sw_netstats *tstats; 341 struct xfrm_state *x; 342 struct xfrm_mode *inner_mode; 343 struct ip6_tnl *t = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6; 344 u32 orig_mark = skb->mark; 345 int ret; 346 347 if (!t) 348 return 1; 349 350 dev = t->dev; 351 352 if (err) { 353 dev->stats.rx_errors++; 354 dev->stats.rx_dropped++; 355 356 return 0; 357 } 358 359 x = xfrm_input_state(skb); 360 361 inner_mode = x->inner_mode; 362 363 if (x->sel.family == AF_UNSPEC) { 364 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol); 365 if (inner_mode == NULL) { 366 XFRM_INC_STATS(dev_net(skb->dev), 367 LINUX_MIB_XFRMINSTATEMODEERROR); 368 return -EINVAL; 369 } 370 } 371 372 family = inner_mode->afinfo->family; 373 374 skb->mark = be32_to_cpu(t->parms.i_key); 375 ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family); 376 skb->mark = orig_mark; 377 378 if (!ret) 379 return -EPERM; 380 381 skb_scrub_packet(skb, !net_eq(t->net, dev_net(skb->dev))); 382 skb->dev = dev; 383 384 tstats = this_cpu_ptr(dev->tstats); 385 u64_stats_update_begin(&tstats->syncp); 386 tstats->rx_packets++; 387 tstats->rx_bytes += skb->len; 388 u64_stats_update_end(&tstats->syncp); 389 390 return 0; 391 } 392 393 /** 394 * vti6_addr_conflict - compare packet addresses to tunnel's own 395 * @t: the outgoing tunnel device 396 * @hdr: IPv6 header from the incoming packet 397 * 398 * Description: 399 * Avoid trivial tunneling loop by checking that tunnel exit-point 400 * doesn't match source of incoming packet. 401 * 402 * Return: 403 * 1 if conflict, 404 * 0 else 405 **/ 406 static inline bool 407 vti6_addr_conflict(const struct ip6_tnl *t, const struct ipv6hdr *hdr) 408 { 409 return ipv6_addr_equal(&t->parms.raddr, &hdr->saddr); 410 } 411 412 static bool vti6_state_check(const struct xfrm_state *x, 413 const struct in6_addr *dst, 414 const struct in6_addr *src) 415 { 416 xfrm_address_t *daddr = (xfrm_address_t *)dst; 417 xfrm_address_t *saddr = (xfrm_address_t *)src; 418 419 /* if there is no transform then this tunnel is not functional. 420 * Or if the xfrm is not mode tunnel. 421 */ 422 if (!x || x->props.mode != XFRM_MODE_TUNNEL || 423 x->props.family != AF_INET6) 424 return false; 425 426 if (ipv6_addr_any(dst)) 427 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET6); 428 429 if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET6)) 430 return false; 431 432 return true; 433 } 434 435 /** 436 * vti6_xmit - send a packet 437 * @skb: the outgoing socket buffer 438 * @dev: the outgoing tunnel device 439 * @fl: the flow informations for the xfrm_lookup 440 **/ 441 static int 442 vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) 443 { 444 struct ip6_tnl *t = netdev_priv(dev); 445 struct net_device_stats *stats = &t->dev->stats; 446 struct dst_entry *dst = skb_dst(skb); 447 struct net_device *tdev; 448 struct xfrm_state *x; 449 int err = -1; 450 int mtu; 451 452 if (!dst) 453 goto tx_err_link_failure; 454 455 dst_hold(dst); 456 dst = xfrm_lookup(t->net, dst, fl, NULL, 0); 457 if (IS_ERR(dst)) { 458 err = PTR_ERR(dst); 459 dst = NULL; 460 goto tx_err_link_failure; 461 } 462 463 x = dst->xfrm; 464 if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr)) 465 goto tx_err_link_failure; 466 467 if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr, 468 (const struct in6_addr *)&x->id.daddr)) 469 goto tx_err_link_failure; 470 471 tdev = dst->dev; 472 473 if (tdev == dev) { 474 stats->collisions++; 475 net_warn_ratelimited("%s: Local routing loop detected!\n", 476 t->parms.name); 477 goto tx_err_dst_release; 478 } 479 480 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 481 skb_dst_set(skb, dst); 482 skb->dev = skb_dst(skb)->dev; 483 484 mtu = dst_mtu(dst); 485 if (!skb->ignore_df && skb->len > mtu) { 486 skb_dst(skb)->ops->update_pmtu(dst, NULL, skb, mtu); 487 488 if (skb->protocol == htons(ETH_P_IPV6)) { 489 if (mtu < IPV6_MIN_MTU) 490 mtu = IPV6_MIN_MTU; 491 492 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 493 } else { 494 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 495 htonl(mtu)); 496 } 497 498 return -EMSGSIZE; 499 } 500 501 err = dst_output(t->net, skb->sk, skb); 502 if (net_xmit_eval(err) == 0) { 503 struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats); 504 505 u64_stats_update_begin(&tstats->syncp); 506 tstats->tx_bytes += skb->len; 507 tstats->tx_packets++; 508 u64_stats_update_end(&tstats->syncp); 509 } else { 510 stats->tx_errors++; 511 stats->tx_aborted_errors++; 512 } 513 514 return 0; 515 tx_err_link_failure: 516 stats->tx_carrier_errors++; 517 dst_link_failure(skb); 518 tx_err_dst_release: 519 dst_release(dst); 520 return err; 521 } 522 523 static netdev_tx_t 524 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 525 { 526 struct ip6_tnl *t = netdev_priv(dev); 527 struct net_device_stats *stats = &t->dev->stats; 528 struct ipv6hdr *ipv6h; 529 struct flowi fl; 530 int ret; 531 532 memset(&fl, 0, sizeof(fl)); 533 534 switch (skb->protocol) { 535 case htons(ETH_P_IPV6): 536 ipv6h = ipv6_hdr(skb); 537 538 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 539 vti6_addr_conflict(t, ipv6h)) 540 goto tx_err; 541 542 xfrm_decode_session(skb, &fl, AF_INET6); 543 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 544 break; 545 case htons(ETH_P_IP): 546 xfrm_decode_session(skb, &fl, AF_INET); 547 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 548 break; 549 default: 550 goto tx_err; 551 } 552 553 /* override mark with tunnel output key */ 554 fl.flowi_mark = be32_to_cpu(t->parms.o_key); 555 556 ret = vti6_xmit(skb, dev, &fl); 557 if (ret < 0) 558 goto tx_err; 559 560 return NETDEV_TX_OK; 561 562 tx_err: 563 stats->tx_errors++; 564 stats->tx_dropped++; 565 kfree_skb(skb); 566 return NETDEV_TX_OK; 567 } 568 569 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 570 u8 type, u8 code, int offset, __be32 info) 571 { 572 __be32 spi; 573 __u32 mark; 574 struct xfrm_state *x; 575 struct ip6_tnl *t; 576 struct ip_esp_hdr *esph; 577 struct ip_auth_hdr *ah; 578 struct ip_comp_hdr *ipch; 579 struct net *net = dev_net(skb->dev); 580 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 581 int protocol = iph->nexthdr; 582 583 t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr); 584 if (!t) 585 return -1; 586 587 mark = be32_to_cpu(t->parms.o_key); 588 589 switch (protocol) { 590 case IPPROTO_ESP: 591 esph = (struct ip_esp_hdr *)(skb->data + offset); 592 spi = esph->spi; 593 break; 594 case IPPROTO_AH: 595 ah = (struct ip_auth_hdr *)(skb->data + offset); 596 spi = ah->spi; 597 break; 598 case IPPROTO_COMP: 599 ipch = (struct ip_comp_hdr *)(skb->data + offset); 600 spi = htonl(ntohs(ipch->cpi)); 601 break; 602 default: 603 return 0; 604 } 605 606 if (type != ICMPV6_PKT_TOOBIG && 607 type != NDISC_REDIRECT) 608 return 0; 609 610 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, 611 spi, protocol, AF_INET6); 612 if (!x) 613 return 0; 614 615 if (type == NDISC_REDIRECT) 616 ip6_redirect(skb, net, skb->dev->ifindex, 0, 617 sock_net_uid(net, NULL)); 618 else 619 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 620 xfrm_state_put(x); 621 622 return 0; 623 } 624 625 static void vti6_link_config(struct ip6_tnl *t) 626 { 627 struct net_device *dev = t->dev; 628 struct __ip6_tnl_parm *p = &t->parms; 629 630 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 631 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 632 633 p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV | 634 IP6_TNL_F_CAP_PER_PACKET); 635 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 636 637 if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV) 638 dev->flags |= IFF_POINTOPOINT; 639 else 640 dev->flags &= ~IFF_POINTOPOINT; 641 } 642 643 /** 644 * vti6_tnl_change - update the tunnel parameters 645 * @t: tunnel to be changed 646 * @p: tunnel configuration parameters 647 * 648 * Description: 649 * vti6_tnl_change() updates the tunnel parameters 650 **/ 651 static int 652 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p) 653 { 654 t->parms.laddr = p->laddr; 655 t->parms.raddr = p->raddr; 656 t->parms.link = p->link; 657 t->parms.i_key = p->i_key; 658 t->parms.o_key = p->o_key; 659 t->parms.proto = p->proto; 660 dst_cache_reset(&t->dst_cache); 661 vti6_link_config(t); 662 return 0; 663 } 664 665 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p) 666 { 667 struct net *net = dev_net(t->dev); 668 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 669 int err; 670 671 vti6_tnl_unlink(ip6n, t); 672 synchronize_net(); 673 err = vti6_tnl_change(t, p); 674 vti6_tnl_link(ip6n, t); 675 netdev_state_change(t->dev); 676 return err; 677 } 678 679 static void 680 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u) 681 { 682 p->laddr = u->laddr; 683 p->raddr = u->raddr; 684 p->link = u->link; 685 p->i_key = u->i_key; 686 p->o_key = u->o_key; 687 p->proto = u->proto; 688 689 memcpy(p->name, u->name, sizeof(u->name)); 690 } 691 692 static void 693 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p) 694 { 695 u->laddr = p->laddr; 696 u->raddr = p->raddr; 697 u->link = p->link; 698 u->i_key = p->i_key; 699 u->o_key = p->o_key; 700 if (u->i_key) 701 u->i_flags |= GRE_KEY; 702 if (u->o_key) 703 u->o_flags |= GRE_KEY; 704 u->proto = p->proto; 705 706 memcpy(u->name, p->name, sizeof(u->name)); 707 } 708 709 /** 710 * vti6_tnl_ioctl - configure vti6 tunnels from userspace 711 * @dev: virtual device associated with tunnel 712 * @ifr: parameters passed from userspace 713 * @cmd: command to be performed 714 * 715 * Description: 716 * vti6_ioctl() is used for managing vti6 tunnels 717 * from userspace. 718 * 719 * The possible commands are the following: 720 * %SIOCGETTUNNEL: get tunnel parameters for device 721 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 722 * %SIOCCHGTUNNEL: change tunnel parameters to those given 723 * %SIOCDELTUNNEL: delete tunnel 724 * 725 * The fallback device "ip6_vti0", created during module 726 * initialization, can be used for creating other tunnel devices. 727 * 728 * Return: 729 * 0 on success, 730 * %-EFAULT if unable to copy data to or from userspace, 731 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 732 * %-EINVAL if passed tunnel parameters are invalid, 733 * %-EEXIST if changing a tunnel's parameters would cause a conflict 734 * %-ENODEV if attempting to change or delete a nonexisting device 735 **/ 736 static int 737 vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 738 { 739 int err = 0; 740 struct ip6_tnl_parm2 p; 741 struct __ip6_tnl_parm p1; 742 struct ip6_tnl *t = NULL; 743 struct net *net = dev_net(dev); 744 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 745 746 switch (cmd) { 747 case SIOCGETTUNNEL: 748 if (dev == ip6n->fb_tnl_dev) { 749 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 750 err = -EFAULT; 751 break; 752 } 753 vti6_parm_from_user(&p1, &p); 754 t = vti6_locate(net, &p1, 0); 755 } else { 756 memset(&p, 0, sizeof(p)); 757 } 758 if (!t) 759 t = netdev_priv(dev); 760 vti6_parm_to_user(&p, &t->parms); 761 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 762 err = -EFAULT; 763 break; 764 case SIOCADDTUNNEL: 765 case SIOCCHGTUNNEL: 766 err = -EPERM; 767 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 768 break; 769 err = -EFAULT; 770 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 771 break; 772 err = -EINVAL; 773 if (p.proto != IPPROTO_IPV6 && p.proto != 0) 774 break; 775 vti6_parm_from_user(&p1, &p); 776 t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL); 777 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 778 if (t) { 779 if (t->dev != dev) { 780 err = -EEXIST; 781 break; 782 } 783 } else 784 t = netdev_priv(dev); 785 786 err = vti6_update(t, &p1); 787 } 788 if (t) { 789 err = 0; 790 vti6_parm_to_user(&p, &t->parms); 791 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 792 err = -EFAULT; 793 794 } else 795 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 796 break; 797 case SIOCDELTUNNEL: 798 err = -EPERM; 799 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 800 break; 801 802 if (dev == ip6n->fb_tnl_dev) { 803 err = -EFAULT; 804 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 805 break; 806 err = -ENOENT; 807 vti6_parm_from_user(&p1, &p); 808 t = vti6_locate(net, &p1, 0); 809 if (!t) 810 break; 811 err = -EPERM; 812 if (t->dev == ip6n->fb_tnl_dev) 813 break; 814 dev = t->dev; 815 } 816 err = 0; 817 unregister_netdevice(dev); 818 break; 819 default: 820 err = -EINVAL; 821 } 822 return err; 823 } 824 825 static const struct net_device_ops vti6_netdev_ops = { 826 .ndo_init = vti6_dev_init, 827 .ndo_uninit = vti6_dev_uninit, 828 .ndo_start_xmit = vti6_tnl_xmit, 829 .ndo_do_ioctl = vti6_ioctl, 830 .ndo_get_stats64 = ip_tunnel_get_stats64, 831 .ndo_get_iflink = ip6_tnl_get_iflink, 832 }; 833 834 /** 835 * vti6_dev_setup - setup virtual tunnel device 836 * @dev: virtual device associated with tunnel 837 * 838 * Description: 839 * Initialize function pointers and device parameters 840 **/ 841 static void vti6_dev_setup(struct net_device *dev) 842 { 843 dev->netdev_ops = &vti6_netdev_ops; 844 dev->destructor = vti6_dev_free; 845 846 dev->type = ARPHRD_TUNNEL6; 847 dev->hard_header_len = LL_MAX_HEADER + sizeof(struct ipv6hdr); 848 dev->mtu = ETH_DATA_LEN; 849 dev->min_mtu = IPV6_MIN_MTU; 850 dev->max_mtu = IP_MAX_MTU; 851 dev->flags |= IFF_NOARP; 852 dev->addr_len = sizeof(struct in6_addr); 853 netif_keep_dst(dev); 854 /* This perm addr will be used as interface identifier by IPv6 */ 855 dev->addr_assign_type = NET_ADDR_RANDOM; 856 eth_random_addr(dev->perm_addr); 857 } 858 859 /** 860 * vti6_dev_init_gen - general initializer for all tunnel devices 861 * @dev: virtual device associated with tunnel 862 **/ 863 static inline int vti6_dev_init_gen(struct net_device *dev) 864 { 865 struct ip6_tnl *t = netdev_priv(dev); 866 867 t->dev = dev; 868 t->net = dev_net(dev); 869 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 870 if (!dev->tstats) 871 return -ENOMEM; 872 return 0; 873 } 874 875 /** 876 * vti6_dev_init - initializer for all non fallback tunnel devices 877 * @dev: virtual device associated with tunnel 878 **/ 879 static int vti6_dev_init(struct net_device *dev) 880 { 881 struct ip6_tnl *t = netdev_priv(dev); 882 int err = vti6_dev_init_gen(dev); 883 884 if (err) 885 return err; 886 vti6_link_config(t); 887 return 0; 888 } 889 890 /** 891 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device 892 * @dev: fallback device 893 * 894 * Return: 0 895 **/ 896 static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev) 897 { 898 struct ip6_tnl *t = netdev_priv(dev); 899 struct net *net = dev_net(dev); 900 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 901 902 t->parms.proto = IPPROTO_IPV6; 903 dev_hold(dev); 904 905 rcu_assign_pointer(ip6n->tnls_wc[0], t); 906 return 0; 907 } 908 909 static int vti6_validate(struct nlattr *tb[], struct nlattr *data[]) 910 { 911 return 0; 912 } 913 914 static void vti6_netlink_parms(struct nlattr *data[], 915 struct __ip6_tnl_parm *parms) 916 { 917 memset(parms, 0, sizeof(*parms)); 918 919 if (!data) 920 return; 921 922 if (data[IFLA_VTI_LINK]) 923 parms->link = nla_get_u32(data[IFLA_VTI_LINK]); 924 925 if (data[IFLA_VTI_LOCAL]) 926 parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]); 927 928 if (data[IFLA_VTI_REMOTE]) 929 parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]); 930 931 if (data[IFLA_VTI_IKEY]) 932 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); 933 934 if (data[IFLA_VTI_OKEY]) 935 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); 936 } 937 938 static int vti6_newlink(struct net *src_net, struct net_device *dev, 939 struct nlattr *tb[], struct nlattr *data[]) 940 { 941 struct net *net = dev_net(dev); 942 struct ip6_tnl *nt; 943 944 nt = netdev_priv(dev); 945 vti6_netlink_parms(data, &nt->parms); 946 947 nt->parms.proto = IPPROTO_IPV6; 948 949 if (vti6_locate(net, &nt->parms, 0)) 950 return -EEXIST; 951 952 return vti6_tnl_create2(dev); 953 } 954 955 static void vti6_dellink(struct net_device *dev, struct list_head *head) 956 { 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 unregister_netdevice_queue(dev, head); 962 } 963 964 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[], 965 struct nlattr *data[]) 966 { 967 struct ip6_tnl *t; 968 struct __ip6_tnl_parm p; 969 struct net *net = dev_net(dev); 970 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 971 972 if (dev == ip6n->fb_tnl_dev) 973 return -EINVAL; 974 975 vti6_netlink_parms(data, &p); 976 977 t = vti6_locate(net, &p, 0); 978 979 if (t) { 980 if (t->dev != dev) 981 return -EEXIST; 982 } else 983 t = netdev_priv(dev); 984 985 return vti6_update(t, &p); 986 } 987 988 static size_t vti6_get_size(const struct net_device *dev) 989 { 990 return 991 /* IFLA_VTI_LINK */ 992 nla_total_size(4) + 993 /* IFLA_VTI_LOCAL */ 994 nla_total_size(sizeof(struct in6_addr)) + 995 /* IFLA_VTI_REMOTE */ 996 nla_total_size(sizeof(struct in6_addr)) + 997 /* IFLA_VTI_IKEY */ 998 nla_total_size(4) + 999 /* IFLA_VTI_OKEY */ 1000 nla_total_size(4) + 1001 0; 1002 } 1003 1004 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1005 { 1006 struct ip6_tnl *tunnel = netdev_priv(dev); 1007 struct __ip6_tnl_parm *parm = &tunnel->parms; 1008 1009 if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) || 1010 nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) || 1011 nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) || 1012 nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) || 1013 nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key)) 1014 goto nla_put_failure; 1015 return 0; 1016 1017 nla_put_failure: 1018 return -EMSGSIZE; 1019 } 1020 1021 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = { 1022 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 1023 [IFLA_VTI_LOCAL] = { .len = sizeof(struct in6_addr) }, 1024 [IFLA_VTI_REMOTE] = { .len = sizeof(struct in6_addr) }, 1025 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 1026 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 1027 }; 1028 1029 static struct rtnl_link_ops vti6_link_ops __read_mostly = { 1030 .kind = "vti6", 1031 .maxtype = IFLA_VTI_MAX, 1032 .policy = vti6_policy, 1033 .priv_size = sizeof(struct ip6_tnl), 1034 .setup = vti6_dev_setup, 1035 .validate = vti6_validate, 1036 .newlink = vti6_newlink, 1037 .dellink = vti6_dellink, 1038 .changelink = vti6_changelink, 1039 .get_size = vti6_get_size, 1040 .fill_info = vti6_fill_info, 1041 .get_link_net = ip6_tnl_get_link_net, 1042 }; 1043 1044 static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n) 1045 { 1046 int h; 1047 struct ip6_tnl *t; 1048 LIST_HEAD(list); 1049 1050 for (h = 0; h < IP6_VTI_HASH_SIZE; h++) { 1051 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1052 while (t) { 1053 unregister_netdevice_queue(t->dev, &list); 1054 t = rtnl_dereference(t->next); 1055 } 1056 } 1057 1058 t = rtnl_dereference(ip6n->tnls_wc[0]); 1059 unregister_netdevice_queue(t->dev, &list); 1060 unregister_netdevice_many(&list); 1061 } 1062 1063 static int __net_init vti6_init_net(struct net *net) 1064 { 1065 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1066 struct ip6_tnl *t = NULL; 1067 int err; 1068 1069 ip6n->tnls[0] = ip6n->tnls_wc; 1070 ip6n->tnls[1] = ip6n->tnls_r_l; 1071 1072 err = -ENOMEM; 1073 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0", 1074 NET_NAME_UNKNOWN, vti6_dev_setup); 1075 1076 if (!ip6n->fb_tnl_dev) 1077 goto err_alloc_dev; 1078 dev_net_set(ip6n->fb_tnl_dev, net); 1079 ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops; 1080 1081 err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1082 if (err < 0) 1083 goto err_register; 1084 1085 err = register_netdev(ip6n->fb_tnl_dev); 1086 if (err < 0) 1087 goto err_register; 1088 1089 t = netdev_priv(ip6n->fb_tnl_dev); 1090 1091 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1092 return 0; 1093 1094 err_register: 1095 vti6_dev_free(ip6n->fb_tnl_dev); 1096 err_alloc_dev: 1097 return err; 1098 } 1099 1100 static void __net_exit vti6_exit_net(struct net *net) 1101 { 1102 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1103 1104 rtnl_lock(); 1105 vti6_destroy_tunnels(ip6n); 1106 rtnl_unlock(); 1107 } 1108 1109 static struct pernet_operations vti6_net_ops = { 1110 .init = vti6_init_net, 1111 .exit = vti6_exit_net, 1112 .id = &vti6_net_id, 1113 .size = sizeof(struct vti6_net), 1114 }; 1115 1116 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = { 1117 .handler = vti6_rcv, 1118 .cb_handler = vti6_rcv_cb, 1119 .err_handler = vti6_err, 1120 .priority = 100, 1121 }; 1122 1123 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = { 1124 .handler = vti6_rcv, 1125 .cb_handler = vti6_rcv_cb, 1126 .err_handler = vti6_err, 1127 .priority = 100, 1128 }; 1129 1130 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = { 1131 .handler = vti6_rcv, 1132 .cb_handler = vti6_rcv_cb, 1133 .err_handler = vti6_err, 1134 .priority = 100, 1135 }; 1136 1137 static bool is_vti6_tunnel(const struct net_device *dev) 1138 { 1139 return dev->netdev_ops == &vti6_netdev_ops; 1140 } 1141 1142 static int vti6_device_event(struct notifier_block *unused, 1143 unsigned long event, void *ptr) 1144 { 1145 struct net_device *dev = netdev_notifier_info_to_dev(ptr); 1146 struct ip6_tnl *t = netdev_priv(dev); 1147 1148 if (!is_vti6_tunnel(dev)) 1149 return NOTIFY_DONE; 1150 1151 switch (event) { 1152 case NETDEV_DOWN: 1153 if (!net_eq(t->net, dev_net(dev))) 1154 xfrm_garbage_collect(t->net); 1155 break; 1156 } 1157 return NOTIFY_DONE; 1158 } 1159 1160 static struct notifier_block vti6_notifier_block __read_mostly = { 1161 .notifier_call = vti6_device_event, 1162 }; 1163 1164 /** 1165 * vti6_tunnel_init - register protocol and reserve needed resources 1166 * 1167 * Return: 0 on success 1168 **/ 1169 static int __init vti6_tunnel_init(void) 1170 { 1171 const char *msg; 1172 int err; 1173 1174 register_netdevice_notifier(&vti6_notifier_block); 1175 1176 msg = "tunnel device"; 1177 err = register_pernet_device(&vti6_net_ops); 1178 if (err < 0) 1179 goto pernet_dev_failed; 1180 1181 msg = "tunnel protocols"; 1182 err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP); 1183 if (err < 0) 1184 goto xfrm_proto_esp_failed; 1185 err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH); 1186 if (err < 0) 1187 goto xfrm_proto_ah_failed; 1188 err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP); 1189 if (err < 0) 1190 goto xfrm_proto_comp_failed; 1191 1192 msg = "netlink interface"; 1193 err = rtnl_link_register(&vti6_link_ops); 1194 if (err < 0) 1195 goto rtnl_link_failed; 1196 1197 return 0; 1198 1199 rtnl_link_failed: 1200 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1201 xfrm_proto_comp_failed: 1202 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1203 xfrm_proto_ah_failed: 1204 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1205 xfrm_proto_esp_failed: 1206 unregister_pernet_device(&vti6_net_ops); 1207 pernet_dev_failed: 1208 unregister_netdevice_notifier(&vti6_notifier_block); 1209 pr_err("vti6 init: failed to register %s\n", msg); 1210 return err; 1211 } 1212 1213 /** 1214 * vti6_tunnel_cleanup - free resources and unregister protocol 1215 **/ 1216 static void __exit vti6_tunnel_cleanup(void) 1217 { 1218 rtnl_link_unregister(&vti6_link_ops); 1219 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1220 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1221 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1222 unregister_pernet_device(&vti6_net_ops); 1223 unregister_netdevice_notifier(&vti6_notifier_block); 1224 } 1225 1226 module_init(vti6_tunnel_init); 1227 module_exit(vti6_tunnel_cleanup); 1228 MODULE_LICENSE("GPL"); 1229 MODULE_ALIAS_RTNL_LINK("vti6"); 1230 MODULE_ALIAS_NETDEV("ip6_vti0"); 1231 MODULE_AUTHOR("Steffen Klassert"); 1232 MODULE_DESCRIPTION("IPv6 virtual tunnel interface"); 1233