1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * IPv6 virtual tunneling interface 4 * 5 * Copyright (C) 2013 secunet Security Networks AG 6 * 7 * Author: 8 * Steffen Klassert <steffen.klassert@secunet.com> 9 * 10 * Based on: 11 * net/ipv6/ip6_tunnel.c 12 */ 13 14 #include <linux/module.h> 15 #include <linux/capability.h> 16 #include <linux/errno.h> 17 #include <linux/types.h> 18 #include <linux/sockios.h> 19 #include <linux/icmp.h> 20 #include <linux/if.h> 21 #include <linux/in.h> 22 #include <linux/ip.h> 23 #include <linux/net.h> 24 #include <linux/in6.h> 25 #include <linux/netdevice.h> 26 #include <linux/if_arp.h> 27 #include <linux/icmpv6.h> 28 #include <linux/init.h> 29 #include <linux/route.h> 30 #include <linux/rtnetlink.h> 31 #include <linux/netfilter_ipv6.h> 32 #include <linux/slab.h> 33 #include <linux/hash.h> 34 35 #include <linux/uaccess.h> 36 #include <linux/atomic.h> 37 38 #include <net/icmp.h> 39 #include <net/ip.h> 40 #include <net/ip_tunnels.h> 41 #include <net/ipv6.h> 42 #include <net/ip6_route.h> 43 #include <net/addrconf.h> 44 #include <net/ip6_tunnel.h> 45 #include <net/xfrm.h> 46 #include <net/net_namespace.h> 47 #include <net/netns/generic.h> 48 #include <linux/etherdevice.h> 49 50 #define IP6_VTI_HASH_SIZE_SHIFT 5 51 #define IP6_VTI_HASH_SIZE (1 << IP6_VTI_HASH_SIZE_SHIFT) 52 53 static u32 HASH(const struct in6_addr *addr1, const struct in6_addr *addr2) 54 { 55 u32 hash = ipv6_addr_hash(addr1) ^ ipv6_addr_hash(addr2); 56 57 return hash_32(hash, IP6_VTI_HASH_SIZE_SHIFT); 58 } 59 60 static int vti6_dev_init(struct net_device *dev); 61 static void vti6_dev_setup(struct net_device *dev); 62 static struct rtnl_link_ops vti6_link_ops __read_mostly; 63 64 static unsigned int vti6_net_id __read_mostly; 65 struct vti6_net { 66 /* the vti6 tunnel fallback device */ 67 struct net_device *fb_tnl_dev; 68 /* lists for storing tunnels in use */ 69 struct ip6_tnl __rcu *tnls_r_l[IP6_VTI_HASH_SIZE]; 70 struct ip6_tnl __rcu *tnls_wc[1]; 71 struct ip6_tnl __rcu **tnls[2]; 72 }; 73 74 #define for_each_vti6_tunnel_rcu(start) \ 75 for (t = rcu_dereference(start); t; t = rcu_dereference(t->next)) 76 77 /** 78 * vti6_tnl_lookup - fetch tunnel matching the end-point addresses 79 * @net: network namespace 80 * @remote: the address of the tunnel exit-point 81 * @local: the address of the tunnel entry-point 82 * 83 * Return: 84 * tunnel matching given end-points if found, 85 * else fallback tunnel if its device is up, 86 * else %NULL 87 **/ 88 static struct ip6_tnl * 89 vti6_tnl_lookup(struct net *net, const struct in6_addr *remote, 90 const struct in6_addr *local) 91 { 92 unsigned int hash = HASH(remote, local); 93 struct ip6_tnl *t; 94 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 95 struct in6_addr any; 96 97 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 98 if (ipv6_addr_equal(local, &t->parms.laddr) && 99 ipv6_addr_equal(remote, &t->parms.raddr) && 100 (t->dev->flags & IFF_UP)) 101 return t; 102 } 103 104 memset(&any, 0, sizeof(any)); 105 hash = HASH(&any, local); 106 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 107 if (ipv6_addr_equal(local, &t->parms.laddr) && 108 (t->dev->flags & IFF_UP)) 109 return t; 110 } 111 112 hash = HASH(remote, &any); 113 for_each_vti6_tunnel_rcu(ip6n->tnls_r_l[hash]) { 114 if (ipv6_addr_equal(remote, &t->parms.raddr) && 115 (t->dev->flags & IFF_UP)) 116 return t; 117 } 118 119 t = rcu_dereference(ip6n->tnls_wc[0]); 120 if (t && (t->dev->flags & IFF_UP)) 121 return t; 122 123 return NULL; 124 } 125 126 /** 127 * vti6_tnl_bucket - get head of list matching given tunnel parameters 128 * @p: parameters containing tunnel end-points 129 * 130 * Description: 131 * vti6_tnl_bucket() returns the head of the list matching the 132 * &struct in6_addr entries laddr and raddr in @p. 133 * 134 * Return: head of IPv6 tunnel list 135 **/ 136 static struct ip6_tnl __rcu ** 137 vti6_tnl_bucket(struct vti6_net *ip6n, const struct __ip6_tnl_parm *p) 138 { 139 const struct in6_addr *remote = &p->raddr; 140 const struct in6_addr *local = &p->laddr; 141 unsigned int h = 0; 142 int prio = 0; 143 144 if (!ipv6_addr_any(remote) || !ipv6_addr_any(local)) { 145 prio = 1; 146 h = HASH(remote, local); 147 } 148 return &ip6n->tnls[prio][h]; 149 } 150 151 static void 152 vti6_tnl_link(struct vti6_net *ip6n, struct ip6_tnl *t) 153 { 154 struct ip6_tnl __rcu **tp = vti6_tnl_bucket(ip6n, &t->parms); 155 156 rcu_assign_pointer(t->next , rtnl_dereference(*tp)); 157 rcu_assign_pointer(*tp, t); 158 } 159 160 static void 161 vti6_tnl_unlink(struct vti6_net *ip6n, struct ip6_tnl *t) 162 { 163 struct ip6_tnl __rcu **tp; 164 struct ip6_tnl *iter; 165 166 for (tp = vti6_tnl_bucket(ip6n, &t->parms); 167 (iter = rtnl_dereference(*tp)) != NULL; 168 tp = &iter->next) { 169 if (t == iter) { 170 rcu_assign_pointer(*tp, t->next); 171 break; 172 } 173 } 174 } 175 176 static void vti6_dev_free(struct net_device *dev) 177 { 178 free_percpu(dev->tstats); 179 } 180 181 static int vti6_tnl_create2(struct net_device *dev) 182 { 183 struct ip6_tnl *t = netdev_priv(dev); 184 struct net *net = dev_net(dev); 185 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 186 int err; 187 188 dev->rtnl_link_ops = &vti6_link_ops; 189 err = register_netdevice(dev); 190 if (err < 0) 191 goto out; 192 193 strcpy(t->parms.name, dev->name); 194 195 dev_hold(dev); 196 vti6_tnl_link(ip6n, t); 197 198 return 0; 199 200 out: 201 return err; 202 } 203 204 static struct ip6_tnl *vti6_tnl_create(struct net *net, struct __ip6_tnl_parm *p) 205 { 206 struct net_device *dev; 207 struct ip6_tnl *t; 208 char name[IFNAMSIZ]; 209 int err; 210 211 if (p->name[0]) { 212 if (!dev_valid_name(p->name)) 213 goto failed; 214 strlcpy(name, p->name, IFNAMSIZ); 215 } else { 216 sprintf(name, "ip6_vti%%d"); 217 } 218 219 dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, vti6_dev_setup); 220 if (!dev) 221 goto failed; 222 223 dev_net_set(dev, net); 224 225 t = netdev_priv(dev); 226 t->parms = *p; 227 t->net = dev_net(dev); 228 229 err = vti6_tnl_create2(dev); 230 if (err < 0) 231 goto failed_free; 232 233 return t; 234 235 failed_free: 236 free_netdev(dev); 237 failed: 238 return NULL; 239 } 240 241 /** 242 * vti6_locate - find or create tunnel matching given parameters 243 * @net: network namespace 244 * @p: tunnel parameters 245 * @create: != 0 if allowed to create new tunnel if no match found 246 * 247 * Description: 248 * vti6_locate() first tries to locate an existing tunnel 249 * based on @parms. If this is unsuccessful, but @create is set a new 250 * tunnel device is created and registered for use. 251 * 252 * Return: 253 * matching tunnel or NULL 254 **/ 255 static struct ip6_tnl *vti6_locate(struct net *net, struct __ip6_tnl_parm *p, 256 int create) 257 { 258 const struct in6_addr *remote = &p->raddr; 259 const struct in6_addr *local = &p->laddr; 260 struct ip6_tnl __rcu **tp; 261 struct ip6_tnl *t; 262 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 263 264 for (tp = vti6_tnl_bucket(ip6n, p); 265 (t = rtnl_dereference(*tp)) != NULL; 266 tp = &t->next) { 267 if (ipv6_addr_equal(local, &t->parms.laddr) && 268 ipv6_addr_equal(remote, &t->parms.raddr)) { 269 if (create) 270 return NULL; 271 272 return t; 273 } 274 } 275 if (!create) 276 return NULL; 277 return vti6_tnl_create(net, p); 278 } 279 280 /** 281 * vti6_dev_uninit - tunnel device uninitializer 282 * @dev: the device to be destroyed 283 * 284 * Description: 285 * vti6_dev_uninit() removes tunnel from its list 286 **/ 287 static void vti6_dev_uninit(struct net_device *dev) 288 { 289 struct ip6_tnl *t = netdev_priv(dev); 290 struct vti6_net *ip6n = net_generic(t->net, vti6_net_id); 291 292 if (dev == ip6n->fb_tnl_dev) 293 RCU_INIT_POINTER(ip6n->tnls_wc[0], NULL); 294 else 295 vti6_tnl_unlink(ip6n, t); 296 dev_put(dev); 297 } 298 299 static int vti6_rcv(struct sk_buff *skb) 300 { 301 struct ip6_tnl *t; 302 const struct ipv6hdr *ipv6h = ipv6_hdr(skb); 303 304 rcu_read_lock(); 305 t = vti6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr, &ipv6h->daddr); 306 if (t) { 307 if (t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) { 308 rcu_read_unlock(); 309 goto discard; 310 } 311 312 if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { 313 rcu_read_unlock(); 314 goto discard; 315 } 316 317 ipv6h = ipv6_hdr(skb); 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 const 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->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 pkt_len = skb->len; 449 int err = -1; 450 int mtu; 451 452 if (!dst) { 453 switch (skb->protocol) { 454 case htons(ETH_P_IP): { 455 struct rtable *rt; 456 457 fl->u.ip4.flowi4_oif = dev->ifindex; 458 fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC; 459 rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4); 460 if (IS_ERR(rt)) 461 goto tx_err_link_failure; 462 dst = &rt->dst; 463 skb_dst_set(skb, dst); 464 break; 465 } 466 case htons(ETH_P_IPV6): 467 fl->u.ip6.flowi6_oif = dev->ifindex; 468 fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC; 469 dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6); 470 if (dst->error) { 471 dst_release(dst); 472 dst = NULL; 473 goto tx_err_link_failure; 474 } 475 skb_dst_set(skb, dst); 476 break; 477 default: 478 goto tx_err_link_failure; 479 } 480 } 481 482 dst_hold(dst); 483 dst = xfrm_lookup(t->net, dst, fl, NULL, 0); 484 if (IS_ERR(dst)) { 485 err = PTR_ERR(dst); 486 dst = NULL; 487 goto tx_err_link_failure; 488 } 489 490 x = dst->xfrm; 491 if (!vti6_state_check(x, &t->parms.raddr, &t->parms.laddr)) 492 goto tx_err_link_failure; 493 494 if (!ip6_tnl_xmit_ctl(t, (const struct in6_addr *)&x->props.saddr, 495 (const struct in6_addr *)&x->id.daddr)) 496 goto tx_err_link_failure; 497 498 tdev = dst->dev; 499 500 if (tdev == dev) { 501 stats->collisions++; 502 net_warn_ratelimited("%s: Local routing loop detected!\n", 503 t->parms.name); 504 goto tx_err_dst_release; 505 } 506 507 mtu = dst_mtu(dst); 508 if (skb->len > mtu) { 509 skb_dst_update_pmtu_no_confirm(skb, mtu); 510 511 if (skb->protocol == htons(ETH_P_IPV6)) { 512 if (mtu < IPV6_MIN_MTU) 513 mtu = IPV6_MIN_MTU; 514 515 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 516 } else { 517 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 518 htonl(mtu)); 519 } 520 521 err = -EMSGSIZE; 522 goto tx_err_dst_release; 523 } 524 525 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 526 skb_dst_set(skb, dst); 527 skb->dev = skb_dst(skb)->dev; 528 529 err = dst_output(t->net, skb->sk, skb); 530 if (net_xmit_eval(err) == 0) 531 err = pkt_len; 532 iptunnel_xmit_stats(dev, err); 533 534 return 0; 535 tx_err_link_failure: 536 stats->tx_carrier_errors++; 537 dst_link_failure(skb); 538 tx_err_dst_release: 539 dst_release(dst); 540 return err; 541 } 542 543 static netdev_tx_t 544 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 545 { 546 struct ip6_tnl *t = netdev_priv(dev); 547 struct net_device_stats *stats = &t->dev->stats; 548 struct flowi fl; 549 int ret; 550 551 if (!pskb_inet_may_pull(skb)) 552 goto tx_err; 553 554 memset(&fl, 0, sizeof(fl)); 555 556 switch (skb->protocol) { 557 case htons(ETH_P_IPV6): 558 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 559 vti6_addr_conflict(t, ipv6_hdr(skb))) 560 goto tx_err; 561 562 xfrm_decode_session(skb, &fl, AF_INET6); 563 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 564 break; 565 case htons(ETH_P_IP): 566 xfrm_decode_session(skb, &fl, AF_INET); 567 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 568 break; 569 default: 570 goto tx_err; 571 } 572 573 /* override mark with tunnel output key */ 574 fl.flowi_mark = be32_to_cpu(t->parms.o_key); 575 576 ret = vti6_xmit(skb, dev, &fl); 577 if (ret < 0) 578 goto tx_err; 579 580 return NETDEV_TX_OK; 581 582 tx_err: 583 stats->tx_errors++; 584 stats->tx_dropped++; 585 kfree_skb(skb); 586 return NETDEV_TX_OK; 587 } 588 589 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 590 u8 type, u8 code, int offset, __be32 info) 591 { 592 __be32 spi; 593 __u32 mark; 594 struct xfrm_state *x; 595 struct ip6_tnl *t; 596 struct ip_esp_hdr *esph; 597 struct ip_auth_hdr *ah; 598 struct ip_comp_hdr *ipch; 599 struct net *net = dev_net(skb->dev); 600 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 601 int protocol = iph->nexthdr; 602 603 t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr); 604 if (!t) 605 return -1; 606 607 mark = be32_to_cpu(t->parms.o_key); 608 609 switch (protocol) { 610 case IPPROTO_ESP: 611 esph = (struct ip_esp_hdr *)(skb->data + offset); 612 spi = esph->spi; 613 break; 614 case IPPROTO_AH: 615 ah = (struct ip_auth_hdr *)(skb->data + offset); 616 spi = ah->spi; 617 break; 618 case IPPROTO_COMP: 619 ipch = (struct ip_comp_hdr *)(skb->data + offset); 620 spi = htonl(ntohs(ipch->cpi)); 621 break; 622 default: 623 return 0; 624 } 625 626 if (type != ICMPV6_PKT_TOOBIG && 627 type != NDISC_REDIRECT) 628 return 0; 629 630 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, 631 spi, protocol, AF_INET6); 632 if (!x) 633 return 0; 634 635 if (type == NDISC_REDIRECT) 636 ip6_redirect(skb, net, skb->dev->ifindex, 0, 637 sock_net_uid(net, NULL)); 638 else 639 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 640 xfrm_state_put(x); 641 642 return 0; 643 } 644 645 static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu) 646 { 647 struct net_device *dev = t->dev; 648 struct __ip6_tnl_parm *p = &t->parms; 649 struct net_device *tdev = NULL; 650 int mtu; 651 652 memcpy(dev->dev_addr, &p->laddr, sizeof(struct in6_addr)); 653 memcpy(dev->broadcast, &p->raddr, sizeof(struct in6_addr)); 654 655 p->flags &= ~(IP6_TNL_F_CAP_XMIT | IP6_TNL_F_CAP_RCV | 656 IP6_TNL_F_CAP_PER_PACKET); 657 p->flags |= ip6_tnl_get_cap(t, &p->laddr, &p->raddr); 658 659 if (p->flags & IP6_TNL_F_CAP_XMIT && p->flags & IP6_TNL_F_CAP_RCV) 660 dev->flags |= IFF_POINTOPOINT; 661 else 662 dev->flags &= ~IFF_POINTOPOINT; 663 664 if (keep_mtu && dev->mtu) { 665 dev->mtu = clamp(dev->mtu, dev->min_mtu, dev->max_mtu); 666 return; 667 } 668 669 if (p->flags & IP6_TNL_F_CAP_XMIT) { 670 int strict = (ipv6_addr_type(&p->raddr) & 671 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); 672 struct rt6_info *rt = rt6_lookup(t->net, 673 &p->raddr, &p->laddr, 674 p->link, NULL, strict); 675 676 if (rt) 677 tdev = rt->dst.dev; 678 ip6_rt_put(rt); 679 } 680 681 if (!tdev && p->link) 682 tdev = __dev_get_by_index(t->net, p->link); 683 684 if (tdev) 685 mtu = tdev->mtu - sizeof(struct ipv6hdr); 686 else 687 mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr); 688 689 dev->mtu = max_t(int, mtu, IPV4_MIN_MTU); 690 } 691 692 /** 693 * vti6_tnl_change - update the tunnel parameters 694 * @t: tunnel to be changed 695 * @p: tunnel configuration parameters 696 * @keep_mtu: MTU was set from userspace, don't re-compute it 697 * 698 * Description: 699 * vti6_tnl_change() updates the tunnel parameters 700 **/ 701 static int 702 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p, 703 bool keep_mtu) 704 { 705 t->parms.laddr = p->laddr; 706 t->parms.raddr = p->raddr; 707 t->parms.link = p->link; 708 t->parms.i_key = p->i_key; 709 t->parms.o_key = p->o_key; 710 t->parms.proto = p->proto; 711 t->parms.fwmark = p->fwmark; 712 dst_cache_reset(&t->dst_cache); 713 vti6_link_config(t, keep_mtu); 714 return 0; 715 } 716 717 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p, 718 bool keep_mtu) 719 { 720 struct net *net = dev_net(t->dev); 721 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 722 int err; 723 724 vti6_tnl_unlink(ip6n, t); 725 synchronize_net(); 726 err = vti6_tnl_change(t, p, keep_mtu); 727 vti6_tnl_link(ip6n, t); 728 netdev_state_change(t->dev); 729 return err; 730 } 731 732 static void 733 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u) 734 { 735 p->laddr = u->laddr; 736 p->raddr = u->raddr; 737 p->link = u->link; 738 p->i_key = u->i_key; 739 p->o_key = u->o_key; 740 p->proto = u->proto; 741 742 memcpy(p->name, u->name, sizeof(u->name)); 743 } 744 745 static void 746 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p) 747 { 748 u->laddr = p->laddr; 749 u->raddr = p->raddr; 750 u->link = p->link; 751 u->i_key = p->i_key; 752 u->o_key = p->o_key; 753 if (u->i_key) 754 u->i_flags |= GRE_KEY; 755 if (u->o_key) 756 u->o_flags |= GRE_KEY; 757 u->proto = p->proto; 758 759 memcpy(u->name, p->name, sizeof(u->name)); 760 } 761 762 /** 763 * vti6_ioctl - configure vti6 tunnels from userspace 764 * @dev: virtual device associated with tunnel 765 * @ifr: parameters passed from userspace 766 * @cmd: command to be performed 767 * 768 * Description: 769 * vti6_ioctl() is used for managing vti6 tunnels 770 * from userspace. 771 * 772 * The possible commands are the following: 773 * %SIOCGETTUNNEL: get tunnel parameters for device 774 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 775 * %SIOCCHGTUNNEL: change tunnel parameters to those given 776 * %SIOCDELTUNNEL: delete tunnel 777 * 778 * The fallback device "ip6_vti0", created during module 779 * initialization, can be used for creating other tunnel devices. 780 * 781 * Return: 782 * 0 on success, 783 * %-EFAULT if unable to copy data to or from userspace, 784 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 785 * %-EINVAL if passed tunnel parameters are invalid, 786 * %-EEXIST if changing a tunnel's parameters would cause a conflict 787 * %-ENODEV if attempting to change or delete a nonexisting device 788 **/ 789 static int 790 vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 791 { 792 int err = 0; 793 struct ip6_tnl_parm2 p; 794 struct __ip6_tnl_parm p1; 795 struct ip6_tnl *t = NULL; 796 struct net *net = dev_net(dev); 797 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 798 799 switch (cmd) { 800 case SIOCGETTUNNEL: 801 if (dev == ip6n->fb_tnl_dev) { 802 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 803 err = -EFAULT; 804 break; 805 } 806 vti6_parm_from_user(&p1, &p); 807 t = vti6_locate(net, &p1, 0); 808 } else { 809 memset(&p, 0, sizeof(p)); 810 } 811 if (!t) 812 t = netdev_priv(dev); 813 vti6_parm_to_user(&p, &t->parms); 814 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 815 err = -EFAULT; 816 break; 817 case SIOCADDTUNNEL: 818 case SIOCCHGTUNNEL: 819 err = -EPERM; 820 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 821 break; 822 err = -EFAULT; 823 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 824 break; 825 err = -EINVAL; 826 if (p.proto != IPPROTO_IPV6 && p.proto != 0) 827 break; 828 vti6_parm_from_user(&p1, &p); 829 t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL); 830 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 831 if (t) { 832 if (t->dev != dev) { 833 err = -EEXIST; 834 break; 835 } 836 } else 837 t = netdev_priv(dev); 838 839 err = vti6_update(t, &p1, false); 840 } 841 if (t) { 842 err = 0; 843 vti6_parm_to_user(&p, &t->parms); 844 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 845 err = -EFAULT; 846 847 } else 848 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 849 break; 850 case SIOCDELTUNNEL: 851 err = -EPERM; 852 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 853 break; 854 855 if (dev == ip6n->fb_tnl_dev) { 856 err = -EFAULT; 857 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 858 break; 859 err = -ENOENT; 860 vti6_parm_from_user(&p1, &p); 861 t = vti6_locate(net, &p1, 0); 862 if (!t) 863 break; 864 err = -EPERM; 865 if (t->dev == ip6n->fb_tnl_dev) 866 break; 867 dev = t->dev; 868 } 869 err = 0; 870 unregister_netdevice(dev); 871 break; 872 default: 873 err = -EINVAL; 874 } 875 return err; 876 } 877 878 static const struct net_device_ops vti6_netdev_ops = { 879 .ndo_init = vti6_dev_init, 880 .ndo_uninit = vti6_dev_uninit, 881 .ndo_start_xmit = vti6_tnl_xmit, 882 .ndo_do_ioctl = vti6_ioctl, 883 .ndo_get_stats64 = ip_tunnel_get_stats64, 884 .ndo_get_iflink = ip6_tnl_get_iflink, 885 }; 886 887 /** 888 * vti6_dev_setup - setup virtual tunnel device 889 * @dev: virtual device associated with tunnel 890 * 891 * Description: 892 * Initialize function pointers and device parameters 893 **/ 894 static void vti6_dev_setup(struct net_device *dev) 895 { 896 dev->netdev_ops = &vti6_netdev_ops; 897 dev->needs_free_netdev = true; 898 dev->priv_destructor = vti6_dev_free; 899 900 dev->type = ARPHRD_TUNNEL6; 901 dev->min_mtu = IPV4_MIN_MTU; 902 dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr); 903 dev->flags |= IFF_NOARP; 904 dev->addr_len = sizeof(struct in6_addr); 905 netif_keep_dst(dev); 906 /* This perm addr will be used as interface identifier by IPv6 */ 907 dev->addr_assign_type = NET_ADDR_RANDOM; 908 eth_random_addr(dev->perm_addr); 909 } 910 911 /** 912 * vti6_dev_init_gen - general initializer for all tunnel devices 913 * @dev: virtual device associated with tunnel 914 **/ 915 static inline int vti6_dev_init_gen(struct net_device *dev) 916 { 917 struct ip6_tnl *t = netdev_priv(dev); 918 919 t->dev = dev; 920 t->net = dev_net(dev); 921 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 922 if (!dev->tstats) 923 return -ENOMEM; 924 return 0; 925 } 926 927 /** 928 * vti6_dev_init - initializer for all non fallback tunnel devices 929 * @dev: virtual device associated with tunnel 930 **/ 931 static int vti6_dev_init(struct net_device *dev) 932 { 933 struct ip6_tnl *t = netdev_priv(dev); 934 int err = vti6_dev_init_gen(dev); 935 936 if (err) 937 return err; 938 vti6_link_config(t, true); 939 return 0; 940 } 941 942 /** 943 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device 944 * @dev: fallback device 945 * 946 * Return: 0 947 **/ 948 static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev) 949 { 950 struct ip6_tnl *t = netdev_priv(dev); 951 struct net *net = dev_net(dev); 952 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 953 954 t->parms.proto = IPPROTO_IPV6; 955 dev_hold(dev); 956 957 rcu_assign_pointer(ip6n->tnls_wc[0], t); 958 return 0; 959 } 960 961 static int vti6_validate(struct nlattr *tb[], struct nlattr *data[], 962 struct netlink_ext_ack *extack) 963 { 964 return 0; 965 } 966 967 static void vti6_netlink_parms(struct nlattr *data[], 968 struct __ip6_tnl_parm *parms) 969 { 970 memset(parms, 0, sizeof(*parms)); 971 972 if (!data) 973 return; 974 975 if (data[IFLA_VTI_LINK]) 976 parms->link = nla_get_u32(data[IFLA_VTI_LINK]); 977 978 if (data[IFLA_VTI_LOCAL]) 979 parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]); 980 981 if (data[IFLA_VTI_REMOTE]) 982 parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]); 983 984 if (data[IFLA_VTI_IKEY]) 985 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); 986 987 if (data[IFLA_VTI_OKEY]) 988 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); 989 990 if (data[IFLA_VTI_FWMARK]) 991 parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]); 992 } 993 994 static int vti6_newlink(struct net *src_net, struct net_device *dev, 995 struct nlattr *tb[], struct nlattr *data[], 996 struct netlink_ext_ack *extack) 997 { 998 struct net *net = dev_net(dev); 999 struct ip6_tnl *nt; 1000 1001 nt = netdev_priv(dev); 1002 vti6_netlink_parms(data, &nt->parms); 1003 1004 nt->parms.proto = IPPROTO_IPV6; 1005 1006 if (vti6_locate(net, &nt->parms, 0)) 1007 return -EEXIST; 1008 1009 return vti6_tnl_create2(dev); 1010 } 1011 1012 static void vti6_dellink(struct net_device *dev, struct list_head *head) 1013 { 1014 struct net *net = dev_net(dev); 1015 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1016 1017 if (dev != ip6n->fb_tnl_dev) 1018 unregister_netdevice_queue(dev, head); 1019 } 1020 1021 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[], 1022 struct nlattr *data[], 1023 struct netlink_ext_ack *extack) 1024 { 1025 struct ip6_tnl *t; 1026 struct __ip6_tnl_parm p; 1027 struct net *net = dev_net(dev); 1028 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1029 1030 if (dev == ip6n->fb_tnl_dev) 1031 return -EINVAL; 1032 1033 vti6_netlink_parms(data, &p); 1034 1035 t = vti6_locate(net, &p, 0); 1036 1037 if (t) { 1038 if (t->dev != dev) 1039 return -EEXIST; 1040 } else 1041 t = netdev_priv(dev); 1042 1043 return vti6_update(t, &p, tb && tb[IFLA_MTU]); 1044 } 1045 1046 static size_t vti6_get_size(const struct net_device *dev) 1047 { 1048 return 1049 /* IFLA_VTI_LINK */ 1050 nla_total_size(4) + 1051 /* IFLA_VTI_LOCAL */ 1052 nla_total_size(sizeof(struct in6_addr)) + 1053 /* IFLA_VTI_REMOTE */ 1054 nla_total_size(sizeof(struct in6_addr)) + 1055 /* IFLA_VTI_IKEY */ 1056 nla_total_size(4) + 1057 /* IFLA_VTI_OKEY */ 1058 nla_total_size(4) + 1059 /* IFLA_VTI_FWMARK */ 1060 nla_total_size(4) + 1061 0; 1062 } 1063 1064 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1065 { 1066 struct ip6_tnl *tunnel = netdev_priv(dev); 1067 struct __ip6_tnl_parm *parm = &tunnel->parms; 1068 1069 if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) || 1070 nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) || 1071 nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) || 1072 nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) || 1073 nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key) || 1074 nla_put_u32(skb, IFLA_VTI_FWMARK, parm->fwmark)) 1075 goto nla_put_failure; 1076 return 0; 1077 1078 nla_put_failure: 1079 return -EMSGSIZE; 1080 } 1081 1082 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = { 1083 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 1084 [IFLA_VTI_LOCAL] = { .len = sizeof(struct in6_addr) }, 1085 [IFLA_VTI_REMOTE] = { .len = sizeof(struct in6_addr) }, 1086 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 1087 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 1088 [IFLA_VTI_FWMARK] = { .type = NLA_U32 }, 1089 }; 1090 1091 static struct rtnl_link_ops vti6_link_ops __read_mostly = { 1092 .kind = "vti6", 1093 .maxtype = IFLA_VTI_MAX, 1094 .policy = vti6_policy, 1095 .priv_size = sizeof(struct ip6_tnl), 1096 .setup = vti6_dev_setup, 1097 .validate = vti6_validate, 1098 .newlink = vti6_newlink, 1099 .dellink = vti6_dellink, 1100 .changelink = vti6_changelink, 1101 .get_size = vti6_get_size, 1102 .fill_info = vti6_fill_info, 1103 .get_link_net = ip6_tnl_get_link_net, 1104 }; 1105 1106 static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n, 1107 struct list_head *list) 1108 { 1109 int h; 1110 struct ip6_tnl *t; 1111 1112 for (h = 0; h < IP6_VTI_HASH_SIZE; h++) { 1113 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1114 while (t) { 1115 unregister_netdevice_queue(t->dev, list); 1116 t = rtnl_dereference(t->next); 1117 } 1118 } 1119 1120 t = rtnl_dereference(ip6n->tnls_wc[0]); 1121 if (t) 1122 unregister_netdevice_queue(t->dev, list); 1123 } 1124 1125 static int __net_init vti6_init_net(struct net *net) 1126 { 1127 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1128 struct ip6_tnl *t = NULL; 1129 int err; 1130 1131 ip6n->tnls[0] = ip6n->tnls_wc; 1132 ip6n->tnls[1] = ip6n->tnls_r_l; 1133 1134 if (!net_has_fallback_tunnels(net)) 1135 return 0; 1136 err = -ENOMEM; 1137 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0", 1138 NET_NAME_UNKNOWN, vti6_dev_setup); 1139 1140 if (!ip6n->fb_tnl_dev) 1141 goto err_alloc_dev; 1142 dev_net_set(ip6n->fb_tnl_dev, net); 1143 ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops; 1144 1145 err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1146 if (err < 0) 1147 goto err_register; 1148 1149 err = register_netdev(ip6n->fb_tnl_dev); 1150 if (err < 0) 1151 goto err_register; 1152 1153 t = netdev_priv(ip6n->fb_tnl_dev); 1154 1155 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1156 return 0; 1157 1158 err_register: 1159 free_netdev(ip6n->fb_tnl_dev); 1160 err_alloc_dev: 1161 return err; 1162 } 1163 1164 static void __net_exit vti6_exit_batch_net(struct list_head *net_list) 1165 { 1166 struct vti6_net *ip6n; 1167 struct net *net; 1168 LIST_HEAD(list); 1169 1170 rtnl_lock(); 1171 list_for_each_entry(net, net_list, exit_list) { 1172 ip6n = net_generic(net, vti6_net_id); 1173 vti6_destroy_tunnels(ip6n, &list); 1174 } 1175 unregister_netdevice_many(&list); 1176 rtnl_unlock(); 1177 } 1178 1179 static struct pernet_operations vti6_net_ops = { 1180 .init = vti6_init_net, 1181 .exit_batch = vti6_exit_batch_net, 1182 .id = &vti6_net_id, 1183 .size = sizeof(struct vti6_net), 1184 }; 1185 1186 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = { 1187 .handler = vti6_rcv, 1188 .cb_handler = vti6_rcv_cb, 1189 .err_handler = vti6_err, 1190 .priority = 100, 1191 }; 1192 1193 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = { 1194 .handler = vti6_rcv, 1195 .cb_handler = vti6_rcv_cb, 1196 .err_handler = vti6_err, 1197 .priority = 100, 1198 }; 1199 1200 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = { 1201 .handler = vti6_rcv, 1202 .cb_handler = vti6_rcv_cb, 1203 .err_handler = vti6_err, 1204 .priority = 100, 1205 }; 1206 1207 /** 1208 * vti6_tunnel_init - register protocol and reserve needed resources 1209 * 1210 * Return: 0 on success 1211 **/ 1212 static int __init vti6_tunnel_init(void) 1213 { 1214 const char *msg; 1215 int err; 1216 1217 msg = "tunnel device"; 1218 err = register_pernet_device(&vti6_net_ops); 1219 if (err < 0) 1220 goto pernet_dev_failed; 1221 1222 msg = "tunnel protocols"; 1223 err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP); 1224 if (err < 0) 1225 goto xfrm_proto_esp_failed; 1226 err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH); 1227 if (err < 0) 1228 goto xfrm_proto_ah_failed; 1229 err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP); 1230 if (err < 0) 1231 goto xfrm_proto_comp_failed; 1232 1233 msg = "netlink interface"; 1234 err = rtnl_link_register(&vti6_link_ops); 1235 if (err < 0) 1236 goto rtnl_link_failed; 1237 1238 return 0; 1239 1240 rtnl_link_failed: 1241 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1242 xfrm_proto_comp_failed: 1243 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1244 xfrm_proto_ah_failed: 1245 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1246 xfrm_proto_esp_failed: 1247 unregister_pernet_device(&vti6_net_ops); 1248 pernet_dev_failed: 1249 pr_err("vti6 init: failed to register %s\n", msg); 1250 return err; 1251 } 1252 1253 /** 1254 * vti6_tunnel_cleanup - free resources and unregister protocol 1255 **/ 1256 static void __exit vti6_tunnel_cleanup(void) 1257 { 1258 rtnl_link_unregister(&vti6_link_ops); 1259 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1260 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1261 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1262 unregister_pernet_device(&vti6_net_ops); 1263 } 1264 1265 module_init(vti6_tunnel_init); 1266 module_exit(vti6_tunnel_cleanup); 1267 MODULE_LICENSE("GPL"); 1268 MODULE_ALIAS_RTNL_LINK("vti6"); 1269 MODULE_ALIAS_NETDEV("ip6_vti0"); 1270 MODULE_AUTHOR("Steffen Klassert"); 1271 MODULE_DESCRIPTION("IPv6 virtual tunnel interface"); 1272