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 return 0; 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 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 mtu = dst_mtu(dst); 481 if (skb->len > mtu) { 482 skb_dst_update_pmtu_no_confirm(skb, mtu); 483 484 if (skb->protocol == htons(ETH_P_IPV6)) { 485 if (mtu < IPV6_MIN_MTU) 486 mtu = IPV6_MIN_MTU; 487 488 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 489 } else { 490 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, 491 htonl(mtu)); 492 } 493 494 err = -EMSGSIZE; 495 goto tx_err_dst_release; 496 } 497 498 skb_scrub_packet(skb, !net_eq(t->net, dev_net(dev))); 499 skb_dst_set(skb, dst); 500 skb->dev = skb_dst(skb)->dev; 501 502 err = dst_output(t->net, skb->sk, skb); 503 if (net_xmit_eval(err) == 0) 504 err = pkt_len; 505 iptunnel_xmit_stats(dev, err); 506 507 return 0; 508 tx_err_link_failure: 509 stats->tx_carrier_errors++; 510 dst_link_failure(skb); 511 tx_err_dst_release: 512 dst_release(dst); 513 return err; 514 } 515 516 static netdev_tx_t 517 vti6_tnl_xmit(struct sk_buff *skb, struct net_device *dev) 518 { 519 struct ip6_tnl *t = netdev_priv(dev); 520 struct net_device_stats *stats = &t->dev->stats; 521 struct flowi fl; 522 int ret; 523 524 if (!pskb_inet_may_pull(skb)) 525 goto tx_err; 526 527 memset(&fl, 0, sizeof(fl)); 528 529 switch (skb->protocol) { 530 case htons(ETH_P_IPV6): 531 if ((t->parms.proto != IPPROTO_IPV6 && t->parms.proto != 0) || 532 vti6_addr_conflict(t, ipv6_hdr(skb))) 533 goto tx_err; 534 535 xfrm_decode_session(skb, &fl, AF_INET6); 536 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb))); 537 break; 538 case htons(ETH_P_IP): 539 xfrm_decode_session(skb, &fl, AF_INET); 540 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 541 break; 542 default: 543 goto tx_err; 544 } 545 546 /* override mark with tunnel output key */ 547 fl.flowi_mark = be32_to_cpu(t->parms.o_key); 548 549 ret = vti6_xmit(skb, dev, &fl); 550 if (ret < 0) 551 goto tx_err; 552 553 return NETDEV_TX_OK; 554 555 tx_err: 556 stats->tx_errors++; 557 stats->tx_dropped++; 558 kfree_skb(skb); 559 return NETDEV_TX_OK; 560 } 561 562 static int vti6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 563 u8 type, u8 code, int offset, __be32 info) 564 { 565 __be32 spi; 566 __u32 mark; 567 struct xfrm_state *x; 568 struct ip6_tnl *t; 569 struct ip_esp_hdr *esph; 570 struct ip_auth_hdr *ah; 571 struct ip_comp_hdr *ipch; 572 struct net *net = dev_net(skb->dev); 573 const struct ipv6hdr *iph = (const struct ipv6hdr *)skb->data; 574 int protocol = iph->nexthdr; 575 576 t = vti6_tnl_lookup(dev_net(skb->dev), &iph->daddr, &iph->saddr); 577 if (!t) 578 return -1; 579 580 mark = be32_to_cpu(t->parms.o_key); 581 582 switch (protocol) { 583 case IPPROTO_ESP: 584 esph = (struct ip_esp_hdr *)(skb->data + offset); 585 spi = esph->spi; 586 break; 587 case IPPROTO_AH: 588 ah = (struct ip_auth_hdr *)(skb->data + offset); 589 spi = ah->spi; 590 break; 591 case IPPROTO_COMP: 592 ipch = (struct ip_comp_hdr *)(skb->data + offset); 593 spi = htonl(ntohs(ipch->cpi)); 594 break; 595 default: 596 return 0; 597 } 598 599 if (type != ICMPV6_PKT_TOOBIG && 600 type != NDISC_REDIRECT) 601 return 0; 602 603 x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr, 604 spi, protocol, AF_INET6); 605 if (!x) 606 return 0; 607 608 if (type == NDISC_REDIRECT) 609 ip6_redirect(skb, net, skb->dev->ifindex, 0, 610 sock_net_uid(net, NULL)); 611 else 612 ip6_update_pmtu(skb, net, info, 0, 0, sock_net_uid(net, NULL)); 613 xfrm_state_put(x); 614 615 return 0; 616 } 617 618 static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu) 619 { 620 struct net_device *dev = t->dev; 621 struct __ip6_tnl_parm *p = &t->parms; 622 struct net_device *tdev = NULL; 623 int mtu; 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 if (keep_mtu && dev->mtu) { 638 dev->mtu = clamp(dev->mtu, dev->min_mtu, dev->max_mtu); 639 return; 640 } 641 642 if (p->flags & IP6_TNL_F_CAP_XMIT) { 643 int strict = (ipv6_addr_type(&p->raddr) & 644 (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)); 645 struct rt6_info *rt = rt6_lookup(t->net, 646 &p->raddr, &p->laddr, 647 p->link, NULL, strict); 648 649 if (rt) 650 tdev = rt->dst.dev; 651 ip6_rt_put(rt); 652 } 653 654 if (!tdev && p->link) 655 tdev = __dev_get_by_index(t->net, p->link); 656 657 if (tdev) 658 mtu = tdev->mtu - sizeof(struct ipv6hdr); 659 else 660 mtu = ETH_DATA_LEN - LL_MAX_HEADER - sizeof(struct ipv6hdr); 661 662 dev->mtu = max_t(int, mtu, IPV4_MIN_MTU); 663 } 664 665 /** 666 * vti6_tnl_change - update the tunnel parameters 667 * @t: tunnel to be changed 668 * @p: tunnel configuration parameters 669 * @keep_mtu: MTU was set from userspace, don't re-compute it 670 * 671 * Description: 672 * vti6_tnl_change() updates the tunnel parameters 673 **/ 674 static int 675 vti6_tnl_change(struct ip6_tnl *t, const struct __ip6_tnl_parm *p, 676 bool keep_mtu) 677 { 678 t->parms.laddr = p->laddr; 679 t->parms.raddr = p->raddr; 680 t->parms.link = p->link; 681 t->parms.i_key = p->i_key; 682 t->parms.o_key = p->o_key; 683 t->parms.proto = p->proto; 684 t->parms.fwmark = p->fwmark; 685 dst_cache_reset(&t->dst_cache); 686 vti6_link_config(t, keep_mtu); 687 return 0; 688 } 689 690 static int vti6_update(struct ip6_tnl *t, struct __ip6_tnl_parm *p, 691 bool keep_mtu) 692 { 693 struct net *net = dev_net(t->dev); 694 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 695 int err; 696 697 vti6_tnl_unlink(ip6n, t); 698 synchronize_net(); 699 err = vti6_tnl_change(t, p, keep_mtu); 700 vti6_tnl_link(ip6n, t); 701 netdev_state_change(t->dev); 702 return err; 703 } 704 705 static void 706 vti6_parm_from_user(struct __ip6_tnl_parm *p, const struct ip6_tnl_parm2 *u) 707 { 708 p->laddr = u->laddr; 709 p->raddr = u->raddr; 710 p->link = u->link; 711 p->i_key = u->i_key; 712 p->o_key = u->o_key; 713 p->proto = u->proto; 714 715 memcpy(p->name, u->name, sizeof(u->name)); 716 } 717 718 static void 719 vti6_parm_to_user(struct ip6_tnl_parm2 *u, const struct __ip6_tnl_parm *p) 720 { 721 u->laddr = p->laddr; 722 u->raddr = p->raddr; 723 u->link = p->link; 724 u->i_key = p->i_key; 725 u->o_key = p->o_key; 726 if (u->i_key) 727 u->i_flags |= GRE_KEY; 728 if (u->o_key) 729 u->o_flags |= GRE_KEY; 730 u->proto = p->proto; 731 732 memcpy(u->name, p->name, sizeof(u->name)); 733 } 734 735 /** 736 * vti6_ioctl - configure vti6 tunnels from userspace 737 * @dev: virtual device associated with tunnel 738 * @ifr: parameters passed from userspace 739 * @cmd: command to be performed 740 * 741 * Description: 742 * vti6_ioctl() is used for managing vti6 tunnels 743 * from userspace. 744 * 745 * The possible commands are the following: 746 * %SIOCGETTUNNEL: get tunnel parameters for device 747 * %SIOCADDTUNNEL: add tunnel matching given tunnel parameters 748 * %SIOCCHGTUNNEL: change tunnel parameters to those given 749 * %SIOCDELTUNNEL: delete tunnel 750 * 751 * The fallback device "ip6_vti0", created during module 752 * initialization, can be used for creating other tunnel devices. 753 * 754 * Return: 755 * 0 on success, 756 * %-EFAULT if unable to copy data to or from userspace, 757 * %-EPERM if current process hasn't %CAP_NET_ADMIN set 758 * %-EINVAL if passed tunnel parameters are invalid, 759 * %-EEXIST if changing a tunnel's parameters would cause a conflict 760 * %-ENODEV if attempting to change or delete a nonexisting device 761 **/ 762 static int 763 vti6_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 764 { 765 int err = 0; 766 struct ip6_tnl_parm2 p; 767 struct __ip6_tnl_parm p1; 768 struct ip6_tnl *t = NULL; 769 struct net *net = dev_net(dev); 770 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 771 772 switch (cmd) { 773 case SIOCGETTUNNEL: 774 if (dev == ip6n->fb_tnl_dev) { 775 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) { 776 err = -EFAULT; 777 break; 778 } 779 vti6_parm_from_user(&p1, &p); 780 t = vti6_locate(net, &p1, 0); 781 } else { 782 memset(&p, 0, sizeof(p)); 783 } 784 if (!t) 785 t = netdev_priv(dev); 786 vti6_parm_to_user(&p, &t->parms); 787 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 788 err = -EFAULT; 789 break; 790 case SIOCADDTUNNEL: 791 case SIOCCHGTUNNEL: 792 err = -EPERM; 793 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 794 break; 795 err = -EFAULT; 796 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 797 break; 798 err = -EINVAL; 799 if (p.proto != IPPROTO_IPV6 && p.proto != 0) 800 break; 801 vti6_parm_from_user(&p1, &p); 802 t = vti6_locate(net, &p1, cmd == SIOCADDTUNNEL); 803 if (dev != ip6n->fb_tnl_dev && cmd == SIOCCHGTUNNEL) { 804 if (t) { 805 if (t->dev != dev) { 806 err = -EEXIST; 807 break; 808 } 809 } else 810 t = netdev_priv(dev); 811 812 err = vti6_update(t, &p1, false); 813 } 814 if (t) { 815 err = 0; 816 vti6_parm_to_user(&p, &t->parms); 817 if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 818 err = -EFAULT; 819 820 } else 821 err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT); 822 break; 823 case SIOCDELTUNNEL: 824 err = -EPERM; 825 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 826 break; 827 828 if (dev == ip6n->fb_tnl_dev) { 829 err = -EFAULT; 830 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 831 break; 832 err = -ENOENT; 833 vti6_parm_from_user(&p1, &p); 834 t = vti6_locate(net, &p1, 0); 835 if (!t) 836 break; 837 err = -EPERM; 838 if (t->dev == ip6n->fb_tnl_dev) 839 break; 840 dev = t->dev; 841 } 842 err = 0; 843 unregister_netdevice(dev); 844 break; 845 default: 846 err = -EINVAL; 847 } 848 return err; 849 } 850 851 static const struct net_device_ops vti6_netdev_ops = { 852 .ndo_init = vti6_dev_init, 853 .ndo_uninit = vti6_dev_uninit, 854 .ndo_start_xmit = vti6_tnl_xmit, 855 .ndo_do_ioctl = vti6_ioctl, 856 .ndo_get_stats64 = ip_tunnel_get_stats64, 857 .ndo_get_iflink = ip6_tnl_get_iflink, 858 }; 859 860 /** 861 * vti6_dev_setup - setup virtual tunnel device 862 * @dev: virtual device associated with tunnel 863 * 864 * Description: 865 * Initialize function pointers and device parameters 866 **/ 867 static void vti6_dev_setup(struct net_device *dev) 868 { 869 dev->netdev_ops = &vti6_netdev_ops; 870 dev->needs_free_netdev = true; 871 dev->priv_destructor = vti6_dev_free; 872 873 dev->type = ARPHRD_TUNNEL6; 874 dev->min_mtu = IPV4_MIN_MTU; 875 dev->max_mtu = IP_MAX_MTU - sizeof(struct ipv6hdr); 876 dev->flags |= IFF_NOARP; 877 dev->addr_len = sizeof(struct in6_addr); 878 netif_keep_dst(dev); 879 /* This perm addr will be used as interface identifier by IPv6 */ 880 dev->addr_assign_type = NET_ADDR_RANDOM; 881 eth_random_addr(dev->perm_addr); 882 } 883 884 /** 885 * vti6_dev_init_gen - general initializer for all tunnel devices 886 * @dev: virtual device associated with tunnel 887 **/ 888 static inline int vti6_dev_init_gen(struct net_device *dev) 889 { 890 struct ip6_tnl *t = netdev_priv(dev); 891 892 t->dev = dev; 893 t->net = dev_net(dev); 894 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 895 if (!dev->tstats) 896 return -ENOMEM; 897 return 0; 898 } 899 900 /** 901 * vti6_dev_init - initializer for all non fallback tunnel devices 902 * @dev: virtual device associated with tunnel 903 **/ 904 static int vti6_dev_init(struct net_device *dev) 905 { 906 struct ip6_tnl *t = netdev_priv(dev); 907 int err = vti6_dev_init_gen(dev); 908 909 if (err) 910 return err; 911 vti6_link_config(t, true); 912 return 0; 913 } 914 915 /** 916 * vti6_fb_tnl_dev_init - initializer for fallback tunnel device 917 * @dev: fallback device 918 * 919 * Return: 0 920 **/ 921 static int __net_init vti6_fb_tnl_dev_init(struct net_device *dev) 922 { 923 struct ip6_tnl *t = netdev_priv(dev); 924 struct net *net = dev_net(dev); 925 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 926 927 t->parms.proto = IPPROTO_IPV6; 928 dev_hold(dev); 929 930 rcu_assign_pointer(ip6n->tnls_wc[0], t); 931 return 0; 932 } 933 934 static int vti6_validate(struct nlattr *tb[], struct nlattr *data[], 935 struct netlink_ext_ack *extack) 936 { 937 return 0; 938 } 939 940 static void vti6_netlink_parms(struct nlattr *data[], 941 struct __ip6_tnl_parm *parms) 942 { 943 memset(parms, 0, sizeof(*parms)); 944 945 if (!data) 946 return; 947 948 if (data[IFLA_VTI_LINK]) 949 parms->link = nla_get_u32(data[IFLA_VTI_LINK]); 950 951 if (data[IFLA_VTI_LOCAL]) 952 parms->laddr = nla_get_in6_addr(data[IFLA_VTI_LOCAL]); 953 954 if (data[IFLA_VTI_REMOTE]) 955 parms->raddr = nla_get_in6_addr(data[IFLA_VTI_REMOTE]); 956 957 if (data[IFLA_VTI_IKEY]) 958 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]); 959 960 if (data[IFLA_VTI_OKEY]) 961 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]); 962 963 if (data[IFLA_VTI_FWMARK]) 964 parms->fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]); 965 } 966 967 static int vti6_newlink(struct net *src_net, struct net_device *dev, 968 struct nlattr *tb[], struct nlattr *data[], 969 struct netlink_ext_ack *extack) 970 { 971 struct net *net = dev_net(dev); 972 struct ip6_tnl *nt; 973 974 nt = netdev_priv(dev); 975 vti6_netlink_parms(data, &nt->parms); 976 977 nt->parms.proto = IPPROTO_IPV6; 978 979 if (vti6_locate(net, &nt->parms, 0)) 980 return -EEXIST; 981 982 return vti6_tnl_create2(dev); 983 } 984 985 static void vti6_dellink(struct net_device *dev, struct list_head *head) 986 { 987 struct net *net = dev_net(dev); 988 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 989 990 if (dev != ip6n->fb_tnl_dev) 991 unregister_netdevice_queue(dev, head); 992 } 993 994 static int vti6_changelink(struct net_device *dev, struct nlattr *tb[], 995 struct nlattr *data[], 996 struct netlink_ext_ack *extack) 997 { 998 struct ip6_tnl *t; 999 struct __ip6_tnl_parm p; 1000 struct net *net = dev_net(dev); 1001 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1002 1003 if (dev == ip6n->fb_tnl_dev) 1004 return -EINVAL; 1005 1006 vti6_netlink_parms(data, &p); 1007 1008 t = vti6_locate(net, &p, 0); 1009 1010 if (t) { 1011 if (t->dev != dev) 1012 return -EEXIST; 1013 } else 1014 t = netdev_priv(dev); 1015 1016 return vti6_update(t, &p, tb && tb[IFLA_MTU]); 1017 } 1018 1019 static size_t vti6_get_size(const struct net_device *dev) 1020 { 1021 return 1022 /* IFLA_VTI_LINK */ 1023 nla_total_size(4) + 1024 /* IFLA_VTI_LOCAL */ 1025 nla_total_size(sizeof(struct in6_addr)) + 1026 /* IFLA_VTI_REMOTE */ 1027 nla_total_size(sizeof(struct in6_addr)) + 1028 /* IFLA_VTI_IKEY */ 1029 nla_total_size(4) + 1030 /* IFLA_VTI_OKEY */ 1031 nla_total_size(4) + 1032 /* IFLA_VTI_FWMARK */ 1033 nla_total_size(4) + 1034 0; 1035 } 1036 1037 static int vti6_fill_info(struct sk_buff *skb, const struct net_device *dev) 1038 { 1039 struct ip6_tnl *tunnel = netdev_priv(dev); 1040 struct __ip6_tnl_parm *parm = &tunnel->parms; 1041 1042 if (nla_put_u32(skb, IFLA_VTI_LINK, parm->link) || 1043 nla_put_in6_addr(skb, IFLA_VTI_LOCAL, &parm->laddr) || 1044 nla_put_in6_addr(skb, IFLA_VTI_REMOTE, &parm->raddr) || 1045 nla_put_be32(skb, IFLA_VTI_IKEY, parm->i_key) || 1046 nla_put_be32(skb, IFLA_VTI_OKEY, parm->o_key) || 1047 nla_put_u32(skb, IFLA_VTI_FWMARK, parm->fwmark)) 1048 goto nla_put_failure; 1049 return 0; 1050 1051 nla_put_failure: 1052 return -EMSGSIZE; 1053 } 1054 1055 static const struct nla_policy vti6_policy[IFLA_VTI_MAX + 1] = { 1056 [IFLA_VTI_LINK] = { .type = NLA_U32 }, 1057 [IFLA_VTI_LOCAL] = { .len = sizeof(struct in6_addr) }, 1058 [IFLA_VTI_REMOTE] = { .len = sizeof(struct in6_addr) }, 1059 [IFLA_VTI_IKEY] = { .type = NLA_U32 }, 1060 [IFLA_VTI_OKEY] = { .type = NLA_U32 }, 1061 [IFLA_VTI_FWMARK] = { .type = NLA_U32 }, 1062 }; 1063 1064 static struct rtnl_link_ops vti6_link_ops __read_mostly = { 1065 .kind = "vti6", 1066 .maxtype = IFLA_VTI_MAX, 1067 .policy = vti6_policy, 1068 .priv_size = sizeof(struct ip6_tnl), 1069 .setup = vti6_dev_setup, 1070 .validate = vti6_validate, 1071 .newlink = vti6_newlink, 1072 .dellink = vti6_dellink, 1073 .changelink = vti6_changelink, 1074 .get_size = vti6_get_size, 1075 .fill_info = vti6_fill_info, 1076 .get_link_net = ip6_tnl_get_link_net, 1077 }; 1078 1079 static void __net_exit vti6_destroy_tunnels(struct vti6_net *ip6n, 1080 struct list_head *list) 1081 { 1082 int h; 1083 struct ip6_tnl *t; 1084 1085 for (h = 0; h < IP6_VTI_HASH_SIZE; h++) { 1086 t = rtnl_dereference(ip6n->tnls_r_l[h]); 1087 while (t) { 1088 unregister_netdevice_queue(t->dev, list); 1089 t = rtnl_dereference(t->next); 1090 } 1091 } 1092 1093 t = rtnl_dereference(ip6n->tnls_wc[0]); 1094 if (t) 1095 unregister_netdevice_queue(t->dev, list); 1096 } 1097 1098 static int __net_init vti6_init_net(struct net *net) 1099 { 1100 struct vti6_net *ip6n = net_generic(net, vti6_net_id); 1101 struct ip6_tnl *t = NULL; 1102 int err; 1103 1104 ip6n->tnls[0] = ip6n->tnls_wc; 1105 ip6n->tnls[1] = ip6n->tnls_r_l; 1106 1107 if (!net_has_fallback_tunnels(net)) 1108 return 0; 1109 err = -ENOMEM; 1110 ip6n->fb_tnl_dev = alloc_netdev(sizeof(struct ip6_tnl), "ip6_vti0", 1111 NET_NAME_UNKNOWN, vti6_dev_setup); 1112 1113 if (!ip6n->fb_tnl_dev) 1114 goto err_alloc_dev; 1115 dev_net_set(ip6n->fb_tnl_dev, net); 1116 ip6n->fb_tnl_dev->rtnl_link_ops = &vti6_link_ops; 1117 1118 err = vti6_fb_tnl_dev_init(ip6n->fb_tnl_dev); 1119 if (err < 0) 1120 goto err_register; 1121 1122 err = register_netdev(ip6n->fb_tnl_dev); 1123 if (err < 0) 1124 goto err_register; 1125 1126 t = netdev_priv(ip6n->fb_tnl_dev); 1127 1128 strcpy(t->parms.name, ip6n->fb_tnl_dev->name); 1129 return 0; 1130 1131 err_register: 1132 free_netdev(ip6n->fb_tnl_dev); 1133 err_alloc_dev: 1134 return err; 1135 } 1136 1137 static void __net_exit vti6_exit_batch_net(struct list_head *net_list) 1138 { 1139 struct vti6_net *ip6n; 1140 struct net *net; 1141 LIST_HEAD(list); 1142 1143 rtnl_lock(); 1144 list_for_each_entry(net, net_list, exit_list) { 1145 ip6n = net_generic(net, vti6_net_id); 1146 vti6_destroy_tunnels(ip6n, &list); 1147 } 1148 unregister_netdevice_many(&list); 1149 rtnl_unlock(); 1150 } 1151 1152 static struct pernet_operations vti6_net_ops = { 1153 .init = vti6_init_net, 1154 .exit_batch = vti6_exit_batch_net, 1155 .id = &vti6_net_id, 1156 .size = sizeof(struct vti6_net), 1157 }; 1158 1159 static struct xfrm6_protocol vti_esp6_protocol __read_mostly = { 1160 .handler = vti6_rcv, 1161 .cb_handler = vti6_rcv_cb, 1162 .err_handler = vti6_err, 1163 .priority = 100, 1164 }; 1165 1166 static struct xfrm6_protocol vti_ah6_protocol __read_mostly = { 1167 .handler = vti6_rcv, 1168 .cb_handler = vti6_rcv_cb, 1169 .err_handler = vti6_err, 1170 .priority = 100, 1171 }; 1172 1173 static struct xfrm6_protocol vti_ipcomp6_protocol __read_mostly = { 1174 .handler = vti6_rcv, 1175 .cb_handler = vti6_rcv_cb, 1176 .err_handler = vti6_err, 1177 .priority = 100, 1178 }; 1179 1180 /** 1181 * vti6_tunnel_init - register protocol and reserve needed resources 1182 * 1183 * Return: 0 on success 1184 **/ 1185 static int __init vti6_tunnel_init(void) 1186 { 1187 const char *msg; 1188 int err; 1189 1190 msg = "tunnel device"; 1191 err = register_pernet_device(&vti6_net_ops); 1192 if (err < 0) 1193 goto pernet_dev_failed; 1194 1195 msg = "tunnel protocols"; 1196 err = xfrm6_protocol_register(&vti_esp6_protocol, IPPROTO_ESP); 1197 if (err < 0) 1198 goto xfrm_proto_esp_failed; 1199 err = xfrm6_protocol_register(&vti_ah6_protocol, IPPROTO_AH); 1200 if (err < 0) 1201 goto xfrm_proto_ah_failed; 1202 err = xfrm6_protocol_register(&vti_ipcomp6_protocol, IPPROTO_COMP); 1203 if (err < 0) 1204 goto xfrm_proto_comp_failed; 1205 1206 msg = "netlink interface"; 1207 err = rtnl_link_register(&vti6_link_ops); 1208 if (err < 0) 1209 goto rtnl_link_failed; 1210 1211 return 0; 1212 1213 rtnl_link_failed: 1214 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1215 xfrm_proto_comp_failed: 1216 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1217 xfrm_proto_ah_failed: 1218 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1219 xfrm_proto_esp_failed: 1220 unregister_pernet_device(&vti6_net_ops); 1221 pernet_dev_failed: 1222 pr_err("vti6 init: failed to register %s\n", msg); 1223 return err; 1224 } 1225 1226 /** 1227 * vti6_tunnel_cleanup - free resources and unregister protocol 1228 **/ 1229 static void __exit vti6_tunnel_cleanup(void) 1230 { 1231 rtnl_link_unregister(&vti6_link_ops); 1232 xfrm6_protocol_deregister(&vti_ipcomp6_protocol, IPPROTO_COMP); 1233 xfrm6_protocol_deregister(&vti_ah6_protocol, IPPROTO_AH); 1234 xfrm6_protocol_deregister(&vti_esp6_protocol, IPPROTO_ESP); 1235 unregister_pernet_device(&vti6_net_ops); 1236 } 1237 1238 module_init(vti6_tunnel_init); 1239 module_exit(vti6_tunnel_cleanup); 1240 MODULE_LICENSE("GPL"); 1241 MODULE_ALIAS_RTNL_LINK("vti6"); 1242 MODULE_ALIAS_NETDEV("ip6_vti0"); 1243 MODULE_AUTHOR("Steffen Klassert"); 1244 MODULE_DESCRIPTION("IPv6 virtual tunnel interface"); 1245