1 /* 2 * Copyright (c) 2013 Nicira, Inc. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 16 * 02110-1301, USA 17 */ 18 19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 20 21 #include <linux/capability.h> 22 #include <linux/module.h> 23 #include <linux/types.h> 24 #include <linux/kernel.h> 25 #include <linux/slab.h> 26 #include <linux/uaccess.h> 27 #include <linux/skbuff.h> 28 #include <linux/netdevice.h> 29 #include <linux/in.h> 30 #include <linux/tcp.h> 31 #include <linux/udp.h> 32 #include <linux/if_arp.h> 33 #include <linux/init.h> 34 #include <linux/in6.h> 35 #include <linux/inetdevice.h> 36 #include <linux/igmp.h> 37 #include <linux/netfilter_ipv4.h> 38 #include <linux/etherdevice.h> 39 #include <linux/if_ether.h> 40 #include <linux/if_vlan.h> 41 #include <linux/rculist.h> 42 #include <linux/err.h> 43 44 #include <net/sock.h> 45 #include <net/ip.h> 46 #include <net/icmp.h> 47 #include <net/protocol.h> 48 #include <net/ip_tunnels.h> 49 #include <net/arp.h> 50 #include <net/checksum.h> 51 #include <net/dsfield.h> 52 #include <net/inet_ecn.h> 53 #include <net/xfrm.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 #include <net/rtnetlink.h> 57 #include <net/udp.h> 58 #include <net/dst_metadata.h> 59 60 #if IS_ENABLED(CONFIG_IPV6) 61 #include <net/ipv6.h> 62 #include <net/ip6_fib.h> 63 #include <net/ip6_route.h> 64 #endif 65 66 static unsigned int ip_tunnel_hash(__be32 key, __be32 remote) 67 { 68 return hash_32((__force u32)key ^ (__force u32)remote, 69 IP_TNL_HASH_BITS); 70 } 71 72 static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p, 73 __be16 flags, __be32 key) 74 { 75 if (p->i_flags & TUNNEL_KEY) { 76 if (flags & TUNNEL_KEY) 77 return key == p->i_key; 78 else 79 /* key expected, none present */ 80 return false; 81 } else 82 return !(flags & TUNNEL_KEY); 83 } 84 85 /* Fallback tunnel: no source, no destination, no key, no options 86 87 Tunnel hash table: 88 We require exact key match i.e. if a key is present in packet 89 it will match only tunnel with the same key; if it is not present, 90 it will match only keyless tunnel. 91 92 All keysless packets, if not matched configured keyless tunnels 93 will match fallback tunnel. 94 Given src, dst and key, find appropriate for input tunnel. 95 */ 96 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 97 int link, __be16 flags, 98 __be32 remote, __be32 local, 99 __be32 key) 100 { 101 unsigned int hash; 102 struct ip_tunnel *t, *cand = NULL; 103 struct hlist_head *head; 104 105 hash = ip_tunnel_hash(key, remote); 106 head = &itn->tunnels[hash]; 107 108 hlist_for_each_entry_rcu(t, head, hash_node) { 109 if (local != t->parms.iph.saddr || 110 remote != t->parms.iph.daddr || 111 !(t->dev->flags & IFF_UP)) 112 continue; 113 114 if (!ip_tunnel_key_match(&t->parms, flags, key)) 115 continue; 116 117 if (t->parms.link == link) 118 return t; 119 else 120 cand = t; 121 } 122 123 hlist_for_each_entry_rcu(t, head, hash_node) { 124 if (remote != t->parms.iph.daddr || 125 t->parms.iph.saddr != 0 || 126 !(t->dev->flags & IFF_UP)) 127 continue; 128 129 if (!ip_tunnel_key_match(&t->parms, flags, key)) 130 continue; 131 132 if (t->parms.link == link) 133 return t; 134 else if (!cand) 135 cand = t; 136 } 137 138 hash = ip_tunnel_hash(key, 0); 139 head = &itn->tunnels[hash]; 140 141 hlist_for_each_entry_rcu(t, head, hash_node) { 142 if ((local != t->parms.iph.saddr || t->parms.iph.daddr != 0) && 143 (local != t->parms.iph.daddr || !ipv4_is_multicast(local))) 144 continue; 145 146 if (!(t->dev->flags & IFF_UP)) 147 continue; 148 149 if (!ip_tunnel_key_match(&t->parms, flags, key)) 150 continue; 151 152 if (t->parms.link == link) 153 return t; 154 else if (!cand) 155 cand = t; 156 } 157 158 if (flags & TUNNEL_NO_KEY) 159 goto skip_key_lookup; 160 161 hlist_for_each_entry_rcu(t, head, hash_node) { 162 if (t->parms.i_key != key || 163 t->parms.iph.saddr != 0 || 164 t->parms.iph.daddr != 0 || 165 !(t->dev->flags & IFF_UP)) 166 continue; 167 168 if (t->parms.link == link) 169 return t; 170 else if (!cand) 171 cand = t; 172 } 173 174 skip_key_lookup: 175 if (cand) 176 return cand; 177 178 t = rcu_dereference(itn->collect_md_tun); 179 if (t && t->dev->flags & IFF_UP) 180 return t; 181 182 if (itn->fb_tunnel_dev && itn->fb_tunnel_dev->flags & IFF_UP) 183 return netdev_priv(itn->fb_tunnel_dev); 184 185 return NULL; 186 } 187 EXPORT_SYMBOL_GPL(ip_tunnel_lookup); 188 189 static struct hlist_head *ip_bucket(struct ip_tunnel_net *itn, 190 struct ip_tunnel_parm *parms) 191 { 192 unsigned int h; 193 __be32 remote; 194 __be32 i_key = parms->i_key; 195 196 if (parms->iph.daddr && !ipv4_is_multicast(parms->iph.daddr)) 197 remote = parms->iph.daddr; 198 else 199 remote = 0; 200 201 if (!(parms->i_flags & TUNNEL_KEY) && (parms->i_flags & VTI_ISVTI)) 202 i_key = 0; 203 204 h = ip_tunnel_hash(i_key, remote); 205 return &itn->tunnels[h]; 206 } 207 208 static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t) 209 { 210 struct hlist_head *head = ip_bucket(itn, &t->parms); 211 212 if (t->collect_md) 213 rcu_assign_pointer(itn->collect_md_tun, t); 214 hlist_add_head_rcu(&t->hash_node, head); 215 } 216 217 static void ip_tunnel_del(struct ip_tunnel_net *itn, struct ip_tunnel *t) 218 { 219 if (t->collect_md) 220 rcu_assign_pointer(itn->collect_md_tun, NULL); 221 hlist_del_init_rcu(&t->hash_node); 222 } 223 224 static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn, 225 struct ip_tunnel_parm *parms, 226 int type) 227 { 228 __be32 remote = parms->iph.daddr; 229 __be32 local = parms->iph.saddr; 230 __be32 key = parms->i_key; 231 __be16 flags = parms->i_flags; 232 int link = parms->link; 233 struct ip_tunnel *t = NULL; 234 struct hlist_head *head = ip_bucket(itn, parms); 235 236 hlist_for_each_entry_rcu(t, head, hash_node) { 237 if (local == t->parms.iph.saddr && 238 remote == t->parms.iph.daddr && 239 link == t->parms.link && 240 type == t->dev->type && 241 ip_tunnel_key_match(&t->parms, flags, key)) 242 break; 243 } 244 return t; 245 } 246 247 static struct net_device *__ip_tunnel_create(struct net *net, 248 const struct rtnl_link_ops *ops, 249 struct ip_tunnel_parm *parms) 250 { 251 int err; 252 struct ip_tunnel *tunnel; 253 struct net_device *dev; 254 char name[IFNAMSIZ]; 255 256 err = -E2BIG; 257 if (parms->name[0]) { 258 if (!dev_valid_name(parms->name)) 259 goto failed; 260 strlcpy(name, parms->name, IFNAMSIZ); 261 } else { 262 if (strlen(ops->kind) > (IFNAMSIZ - 3)) 263 goto failed; 264 strcpy(name, ops->kind); 265 strcat(name, "%d"); 266 } 267 268 ASSERT_RTNL(); 269 dev = alloc_netdev(ops->priv_size, name, NET_NAME_UNKNOWN, ops->setup); 270 if (!dev) { 271 err = -ENOMEM; 272 goto failed; 273 } 274 dev_net_set(dev, net); 275 276 dev->rtnl_link_ops = ops; 277 278 tunnel = netdev_priv(dev); 279 tunnel->parms = *parms; 280 tunnel->net = net; 281 282 err = register_netdevice(dev); 283 if (err) 284 goto failed_free; 285 286 return dev; 287 288 failed_free: 289 free_netdev(dev); 290 failed: 291 return ERR_PTR(err); 292 } 293 294 static int ip_tunnel_bind_dev(struct net_device *dev) 295 { 296 struct net_device *tdev = NULL; 297 struct ip_tunnel *tunnel = netdev_priv(dev); 298 const struct iphdr *iph; 299 int hlen = LL_MAX_HEADER; 300 int mtu = ETH_DATA_LEN; 301 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 302 303 iph = &tunnel->parms.iph; 304 305 /* Guess output device to choose reasonable mtu and needed_headroom */ 306 if (iph->daddr) { 307 struct flowi4 fl4; 308 struct rtable *rt; 309 310 ip_tunnel_init_flow(&fl4, iph->protocol, iph->daddr, 311 iph->saddr, tunnel->parms.o_key, 312 RT_TOS(iph->tos), tunnel->parms.link, 313 tunnel->fwmark, 0); 314 rt = ip_route_output_key(tunnel->net, &fl4); 315 316 if (!IS_ERR(rt)) { 317 tdev = rt->dst.dev; 318 ip_rt_put(rt); 319 } 320 if (dev->type != ARPHRD_ETHER) 321 dev->flags |= IFF_POINTOPOINT; 322 323 dst_cache_reset(&tunnel->dst_cache); 324 } 325 326 if (!tdev && tunnel->parms.link) 327 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 328 329 if (tdev) { 330 hlen = tdev->hard_header_len + tdev->needed_headroom; 331 mtu = min(tdev->mtu, IP_MAX_MTU); 332 } 333 334 dev->needed_headroom = t_hlen + hlen; 335 mtu -= (dev->hard_header_len + t_hlen); 336 337 if (mtu < IPV4_MIN_MTU) 338 mtu = IPV4_MIN_MTU; 339 340 return mtu; 341 } 342 343 static struct ip_tunnel *ip_tunnel_create(struct net *net, 344 struct ip_tunnel_net *itn, 345 struct ip_tunnel_parm *parms) 346 { 347 struct ip_tunnel *nt; 348 struct net_device *dev; 349 int t_hlen; 350 int mtu; 351 int err; 352 353 dev = __ip_tunnel_create(net, itn->rtnl_link_ops, parms); 354 if (IS_ERR(dev)) 355 return ERR_CAST(dev); 356 357 mtu = ip_tunnel_bind_dev(dev); 358 err = dev_set_mtu(dev, mtu); 359 if (err) 360 goto err_dev_set_mtu; 361 362 nt = netdev_priv(dev); 363 t_hlen = nt->hlen + sizeof(struct iphdr); 364 dev->min_mtu = ETH_MIN_MTU; 365 dev->max_mtu = IP_MAX_MTU - dev->hard_header_len - t_hlen; 366 ip_tunnel_add(itn, nt); 367 return nt; 368 369 err_dev_set_mtu: 370 unregister_netdevice(dev); 371 return ERR_PTR(err); 372 } 373 374 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, 375 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, 376 bool log_ecn_error) 377 { 378 struct pcpu_sw_netstats *tstats; 379 const struct iphdr *iph = ip_hdr(skb); 380 int err; 381 382 #ifdef CONFIG_NET_IPGRE_BROADCAST 383 if (ipv4_is_multicast(iph->daddr)) { 384 tunnel->dev->stats.multicast++; 385 skb->pkt_type = PACKET_BROADCAST; 386 } 387 #endif 388 389 if ((!(tpi->flags&TUNNEL_CSUM) && (tunnel->parms.i_flags&TUNNEL_CSUM)) || 390 ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) { 391 tunnel->dev->stats.rx_crc_errors++; 392 tunnel->dev->stats.rx_errors++; 393 goto drop; 394 } 395 396 if (tunnel->parms.i_flags&TUNNEL_SEQ) { 397 if (!(tpi->flags&TUNNEL_SEQ) || 398 (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) { 399 tunnel->dev->stats.rx_fifo_errors++; 400 tunnel->dev->stats.rx_errors++; 401 goto drop; 402 } 403 tunnel->i_seqno = ntohl(tpi->seq) + 1; 404 } 405 406 skb_reset_network_header(skb); 407 408 err = IP_ECN_decapsulate(iph, skb); 409 if (unlikely(err)) { 410 if (log_ecn_error) 411 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 412 &iph->saddr, iph->tos); 413 if (err > 1) { 414 ++tunnel->dev->stats.rx_frame_errors; 415 ++tunnel->dev->stats.rx_errors; 416 goto drop; 417 } 418 } 419 420 tstats = this_cpu_ptr(tunnel->dev->tstats); 421 u64_stats_update_begin(&tstats->syncp); 422 tstats->rx_packets++; 423 tstats->rx_bytes += skb->len; 424 u64_stats_update_end(&tstats->syncp); 425 426 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev))); 427 428 if (tunnel->dev->type == ARPHRD_ETHER) { 429 skb->protocol = eth_type_trans(skb, tunnel->dev); 430 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN); 431 } else { 432 skb->dev = tunnel->dev; 433 } 434 435 if (tun_dst) 436 skb_dst_set(skb, (struct dst_entry *)tun_dst); 437 438 gro_cells_receive(&tunnel->gro_cells, skb); 439 return 0; 440 441 drop: 442 if (tun_dst) 443 dst_release((struct dst_entry *)tun_dst); 444 kfree_skb(skb); 445 return 0; 446 } 447 EXPORT_SYMBOL_GPL(ip_tunnel_rcv); 448 449 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops, 450 unsigned int num) 451 { 452 if (num >= MAX_IPTUN_ENCAP_OPS) 453 return -ERANGE; 454 455 return !cmpxchg((const struct ip_tunnel_encap_ops **) 456 &iptun_encaps[num], 457 NULL, ops) ? 0 : -1; 458 } 459 EXPORT_SYMBOL(ip_tunnel_encap_add_ops); 460 461 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops, 462 unsigned int num) 463 { 464 int ret; 465 466 if (num >= MAX_IPTUN_ENCAP_OPS) 467 return -ERANGE; 468 469 ret = (cmpxchg((const struct ip_tunnel_encap_ops **) 470 &iptun_encaps[num], 471 ops, NULL) == ops) ? 0 : -1; 472 473 synchronize_net(); 474 475 return ret; 476 } 477 EXPORT_SYMBOL(ip_tunnel_encap_del_ops); 478 479 int ip_tunnel_encap_setup(struct ip_tunnel *t, 480 struct ip_tunnel_encap *ipencap) 481 { 482 int hlen; 483 484 memset(&t->encap, 0, sizeof(t->encap)); 485 486 hlen = ip_encap_hlen(ipencap); 487 if (hlen < 0) 488 return hlen; 489 490 t->encap.type = ipencap->type; 491 t->encap.sport = ipencap->sport; 492 t->encap.dport = ipencap->dport; 493 t->encap.flags = ipencap->flags; 494 495 t->encap_hlen = hlen; 496 t->hlen = t->encap_hlen + t->tun_hlen; 497 498 return 0; 499 } 500 EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup); 501 502 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, 503 struct rtable *rt, __be16 df, 504 const struct iphdr *inner_iph, 505 int tunnel_hlen, __be32 dst, bool md) 506 { 507 struct ip_tunnel *tunnel = netdev_priv(dev); 508 int pkt_size; 509 int mtu; 510 511 tunnel_hlen = md ? tunnel_hlen : tunnel->hlen; 512 pkt_size = skb->len - tunnel_hlen - dev->hard_header_len; 513 514 if (df) 515 mtu = dst_mtu(&rt->dst) - dev->hard_header_len 516 - sizeof(struct iphdr) - tunnel_hlen; 517 else 518 mtu = skb_valid_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; 519 520 if (skb_valid_dst(skb)) 521 skb_dst_update_pmtu(skb, mtu); 522 523 if (skb->protocol == htons(ETH_P_IP)) { 524 if (!skb_is_gso(skb) && 525 (inner_iph->frag_off & htons(IP_DF)) && 526 mtu < pkt_size) { 527 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 528 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 529 return -E2BIG; 530 } 531 } 532 #if IS_ENABLED(CONFIG_IPV6) 533 else if (skb->protocol == htons(ETH_P_IPV6)) { 534 struct rt6_info *rt6; 535 __be32 daddr; 536 537 rt6 = skb_valid_dst(skb) ? (struct rt6_info *)skb_dst(skb) : 538 NULL; 539 daddr = md ? dst : tunnel->parms.iph.daddr; 540 541 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && 542 mtu >= IPV6_MIN_MTU) { 543 if ((daddr && !ipv4_is_multicast(daddr)) || 544 rt6->rt6i_dst.plen == 128) { 545 rt6->rt6i_flags |= RTF_MODIFIED; 546 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); 547 } 548 } 549 550 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && 551 mtu < pkt_size) { 552 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 553 return -E2BIG; 554 } 555 } 556 #endif 557 return 0; 558 } 559 560 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 561 u8 proto, int tunnel_hlen) 562 { 563 struct ip_tunnel *tunnel = netdev_priv(dev); 564 u32 headroom = sizeof(struct iphdr); 565 struct ip_tunnel_info *tun_info; 566 const struct ip_tunnel_key *key; 567 const struct iphdr *inner_iph; 568 struct rtable *rt = NULL; 569 struct flowi4 fl4; 570 __be16 df = 0; 571 u8 tos, ttl; 572 bool use_cache; 573 574 tun_info = skb_tunnel_info(skb); 575 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 576 ip_tunnel_info_af(tun_info) != AF_INET)) 577 goto tx_error; 578 key = &tun_info->key; 579 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 580 inner_iph = (const struct iphdr *)skb_inner_network_header(skb); 581 tos = key->tos; 582 if (tos == 1) { 583 if (skb->protocol == htons(ETH_P_IP)) 584 tos = inner_iph->tos; 585 else if (skb->protocol == htons(ETH_P_IPV6)) 586 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); 587 } 588 ip_tunnel_init_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src, 589 tunnel_id_to_key32(key->tun_id), RT_TOS(tos), 590 0, skb->mark, skb_get_hash(skb)); 591 if (tunnel->encap.type != TUNNEL_ENCAP_NONE) 592 goto tx_error; 593 594 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 595 if (use_cache) 596 rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl4.saddr); 597 if (!rt) { 598 rt = ip_route_output_key(tunnel->net, &fl4); 599 if (IS_ERR(rt)) { 600 dev->stats.tx_carrier_errors++; 601 goto tx_error; 602 } 603 if (use_cache) 604 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 605 fl4.saddr); 606 } 607 if (rt->dst.dev == dev) { 608 ip_rt_put(rt); 609 dev->stats.collisions++; 610 goto tx_error; 611 } 612 613 if (key->tun_flags & TUNNEL_DONT_FRAGMENT) 614 df = htons(IP_DF); 615 if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, tunnel_hlen, 616 key->u.ipv4.dst, true)) { 617 ip_rt_put(rt); 618 goto tx_error; 619 } 620 621 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 622 ttl = key->ttl; 623 if (ttl == 0) { 624 if (skb->protocol == htons(ETH_P_IP)) 625 ttl = inner_iph->ttl; 626 else if (skb->protocol == htons(ETH_P_IPV6)) 627 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 628 else 629 ttl = ip4_dst_hoplimit(&rt->dst); 630 } 631 632 if (!df && skb->protocol == htons(ETH_P_IP)) 633 df = inner_iph->frag_off & htons(IP_DF); 634 635 headroom += LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len; 636 if (headroom > dev->needed_headroom) 637 dev->needed_headroom = headroom; 638 639 if (skb_cow_head(skb, dev->needed_headroom)) { 640 ip_rt_put(rt); 641 goto tx_dropped; 642 } 643 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, proto, tos, ttl, 644 df, !net_eq(tunnel->net, dev_net(dev))); 645 return; 646 tx_error: 647 dev->stats.tx_errors++; 648 goto kfree; 649 tx_dropped: 650 dev->stats.tx_dropped++; 651 kfree: 652 kfree_skb(skb); 653 } 654 EXPORT_SYMBOL_GPL(ip_md_tunnel_xmit); 655 656 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 657 const struct iphdr *tnl_params, u8 protocol) 658 { 659 struct ip_tunnel *tunnel = netdev_priv(dev); 660 struct ip_tunnel_info *tun_info = NULL; 661 const struct iphdr *inner_iph; 662 unsigned int max_headroom; /* The extra header space needed */ 663 struct rtable *rt = NULL; /* Route to the other host */ 664 bool use_cache = false; 665 struct flowi4 fl4; 666 bool md = false; 667 bool connected; 668 u8 tos, ttl; 669 __be32 dst; 670 __be16 df; 671 672 inner_iph = (const struct iphdr *)skb_inner_network_header(skb); 673 connected = (tunnel->parms.iph.daddr != 0); 674 675 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 676 677 dst = tnl_params->daddr; 678 if (dst == 0) { 679 /* NBMA tunnel */ 680 681 if (!skb_dst(skb)) { 682 dev->stats.tx_fifo_errors++; 683 goto tx_error; 684 } 685 686 tun_info = skb_tunnel_info(skb); 687 if (tun_info && (tun_info->mode & IP_TUNNEL_INFO_TX) && 688 ip_tunnel_info_af(tun_info) == AF_INET && 689 tun_info->key.u.ipv4.dst) { 690 dst = tun_info->key.u.ipv4.dst; 691 md = true; 692 connected = true; 693 } 694 else if (skb->protocol == htons(ETH_P_IP)) { 695 rt = skb_rtable(skb); 696 dst = rt_nexthop(rt, inner_iph->daddr); 697 } 698 #if IS_ENABLED(CONFIG_IPV6) 699 else if (skb->protocol == htons(ETH_P_IPV6)) { 700 const struct in6_addr *addr6; 701 struct neighbour *neigh; 702 bool do_tx_error_icmp; 703 int addr_type; 704 705 neigh = dst_neigh_lookup(skb_dst(skb), 706 &ipv6_hdr(skb)->daddr); 707 if (!neigh) 708 goto tx_error; 709 710 addr6 = (const struct in6_addr *)&neigh->primary_key; 711 addr_type = ipv6_addr_type(addr6); 712 713 if (addr_type == IPV6_ADDR_ANY) { 714 addr6 = &ipv6_hdr(skb)->daddr; 715 addr_type = ipv6_addr_type(addr6); 716 } 717 718 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 719 do_tx_error_icmp = true; 720 else { 721 do_tx_error_icmp = false; 722 dst = addr6->s6_addr32[3]; 723 } 724 neigh_release(neigh); 725 if (do_tx_error_icmp) 726 goto tx_error_icmp; 727 } 728 #endif 729 else 730 goto tx_error; 731 732 if (!md) 733 connected = false; 734 } 735 736 tos = tnl_params->tos; 737 if (tos & 0x1) { 738 tos &= ~0x1; 739 if (skb->protocol == htons(ETH_P_IP)) { 740 tos = inner_iph->tos; 741 connected = false; 742 } else if (skb->protocol == htons(ETH_P_IPV6)) { 743 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); 744 connected = false; 745 } 746 } 747 748 ip_tunnel_init_flow(&fl4, protocol, dst, tnl_params->saddr, 749 tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link, 750 tunnel->fwmark, skb_get_hash(skb)); 751 752 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) 753 goto tx_error; 754 755 if (connected && md) { 756 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 757 if (use_cache) 758 rt = dst_cache_get_ip4(&tun_info->dst_cache, 759 &fl4.saddr); 760 } else { 761 rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, 762 &fl4.saddr) : NULL; 763 } 764 765 if (!rt) { 766 rt = ip_route_output_key(tunnel->net, &fl4); 767 768 if (IS_ERR(rt)) { 769 dev->stats.tx_carrier_errors++; 770 goto tx_error; 771 } 772 if (use_cache) 773 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 774 fl4.saddr); 775 else if (!md && connected) 776 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, 777 fl4.saddr); 778 } 779 780 if (rt->dst.dev == dev) { 781 ip_rt_put(rt); 782 dev->stats.collisions++; 783 goto tx_error; 784 } 785 786 if (tnl_update_pmtu(dev, skb, rt, tnl_params->frag_off, inner_iph, 787 0, 0, false)) { 788 ip_rt_put(rt); 789 goto tx_error; 790 } 791 792 if (tunnel->err_count > 0) { 793 if (time_before(jiffies, 794 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 795 tunnel->err_count--; 796 797 dst_link_failure(skb); 798 } else 799 tunnel->err_count = 0; 800 } 801 802 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 803 ttl = tnl_params->ttl; 804 if (ttl == 0) { 805 if (skb->protocol == htons(ETH_P_IP)) 806 ttl = inner_iph->ttl; 807 #if IS_ENABLED(CONFIG_IPV6) 808 else if (skb->protocol == htons(ETH_P_IPV6)) 809 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 810 #endif 811 else 812 ttl = ip4_dst_hoplimit(&rt->dst); 813 } 814 815 df = tnl_params->frag_off; 816 if (skb->protocol == htons(ETH_P_IP) && !tunnel->ignore_df) 817 df |= (inner_iph->frag_off&htons(IP_DF)); 818 819 max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) 820 + rt->dst.header_len + ip_encap_hlen(&tunnel->encap); 821 if (max_headroom > dev->needed_headroom) 822 dev->needed_headroom = max_headroom; 823 824 if (skb_cow_head(skb, dev->needed_headroom)) { 825 ip_rt_put(rt); 826 dev->stats.tx_dropped++; 827 kfree_skb(skb); 828 return; 829 } 830 831 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, 832 df, !net_eq(tunnel->net, dev_net(dev))); 833 return; 834 835 #if IS_ENABLED(CONFIG_IPV6) 836 tx_error_icmp: 837 dst_link_failure(skb); 838 #endif 839 tx_error: 840 dev->stats.tx_errors++; 841 kfree_skb(skb); 842 } 843 EXPORT_SYMBOL_GPL(ip_tunnel_xmit); 844 845 static void ip_tunnel_update(struct ip_tunnel_net *itn, 846 struct ip_tunnel *t, 847 struct net_device *dev, 848 struct ip_tunnel_parm *p, 849 bool set_mtu, 850 __u32 fwmark) 851 { 852 ip_tunnel_del(itn, t); 853 t->parms.iph.saddr = p->iph.saddr; 854 t->parms.iph.daddr = p->iph.daddr; 855 t->parms.i_key = p->i_key; 856 t->parms.o_key = p->o_key; 857 if (dev->type != ARPHRD_ETHER) { 858 memcpy(dev->dev_addr, &p->iph.saddr, 4); 859 memcpy(dev->broadcast, &p->iph.daddr, 4); 860 } 861 ip_tunnel_add(itn, t); 862 863 t->parms.iph.ttl = p->iph.ttl; 864 t->parms.iph.tos = p->iph.tos; 865 t->parms.iph.frag_off = p->iph.frag_off; 866 867 if (t->parms.link != p->link || t->fwmark != fwmark) { 868 int mtu; 869 870 t->parms.link = p->link; 871 t->fwmark = fwmark; 872 mtu = ip_tunnel_bind_dev(dev); 873 if (set_mtu) 874 dev->mtu = mtu; 875 } 876 dst_cache_reset(&t->dst_cache); 877 netdev_state_change(dev); 878 } 879 880 int ip_tunnel_ioctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) 881 { 882 int err = 0; 883 struct ip_tunnel *t = netdev_priv(dev); 884 struct net *net = t->net; 885 struct ip_tunnel_net *itn = net_generic(net, t->ip_tnl_net_id); 886 887 switch (cmd) { 888 case SIOCGETTUNNEL: 889 if (dev == itn->fb_tunnel_dev) { 890 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 891 if (!t) 892 t = netdev_priv(dev); 893 } 894 memcpy(p, &t->parms, sizeof(*p)); 895 break; 896 897 case SIOCADDTUNNEL: 898 case SIOCCHGTUNNEL: 899 err = -EPERM; 900 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 901 goto done; 902 if (p->iph.ttl) 903 p->iph.frag_off |= htons(IP_DF); 904 if (!(p->i_flags & VTI_ISVTI)) { 905 if (!(p->i_flags & TUNNEL_KEY)) 906 p->i_key = 0; 907 if (!(p->o_flags & TUNNEL_KEY)) 908 p->o_key = 0; 909 } 910 911 t = ip_tunnel_find(itn, p, itn->type); 912 913 if (cmd == SIOCADDTUNNEL) { 914 if (!t) { 915 t = ip_tunnel_create(net, itn, p); 916 err = PTR_ERR_OR_ZERO(t); 917 break; 918 } 919 920 err = -EEXIST; 921 break; 922 } 923 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 924 if (t) { 925 if (t->dev != dev) { 926 err = -EEXIST; 927 break; 928 } 929 } else { 930 unsigned int nflags = 0; 931 932 if (ipv4_is_multicast(p->iph.daddr)) 933 nflags = IFF_BROADCAST; 934 else if (p->iph.daddr) 935 nflags = IFF_POINTOPOINT; 936 937 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { 938 err = -EINVAL; 939 break; 940 } 941 942 t = netdev_priv(dev); 943 } 944 } 945 946 if (t) { 947 err = 0; 948 ip_tunnel_update(itn, t, dev, p, true, 0); 949 } else { 950 err = -ENOENT; 951 } 952 break; 953 954 case SIOCDELTUNNEL: 955 err = -EPERM; 956 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 957 goto done; 958 959 if (dev == itn->fb_tunnel_dev) { 960 err = -ENOENT; 961 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 962 if (!t) 963 goto done; 964 err = -EPERM; 965 if (t == netdev_priv(itn->fb_tunnel_dev)) 966 goto done; 967 dev = t->dev; 968 } 969 unregister_netdevice(dev); 970 err = 0; 971 break; 972 973 default: 974 err = -EINVAL; 975 } 976 977 done: 978 return err; 979 } 980 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl); 981 982 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) 983 { 984 struct ip_tunnel *tunnel = netdev_priv(dev); 985 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 986 int max_mtu = IP_MAX_MTU - dev->hard_header_len - t_hlen; 987 988 if (new_mtu < ETH_MIN_MTU) 989 return -EINVAL; 990 991 if (new_mtu > max_mtu) { 992 if (strict) 993 return -EINVAL; 994 995 new_mtu = max_mtu; 996 } 997 998 dev->mtu = new_mtu; 999 return 0; 1000 } 1001 EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu); 1002 1003 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1004 { 1005 return __ip_tunnel_change_mtu(dev, new_mtu, true); 1006 } 1007 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu); 1008 1009 static void ip_tunnel_dev_free(struct net_device *dev) 1010 { 1011 struct ip_tunnel *tunnel = netdev_priv(dev); 1012 1013 gro_cells_destroy(&tunnel->gro_cells); 1014 dst_cache_destroy(&tunnel->dst_cache); 1015 free_percpu(dev->tstats); 1016 } 1017 1018 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) 1019 { 1020 struct ip_tunnel *tunnel = netdev_priv(dev); 1021 struct ip_tunnel_net *itn; 1022 1023 itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); 1024 1025 if (itn->fb_tunnel_dev != dev) { 1026 ip_tunnel_del(itn, netdev_priv(dev)); 1027 unregister_netdevice_queue(dev, head); 1028 } 1029 } 1030 EXPORT_SYMBOL_GPL(ip_tunnel_dellink); 1031 1032 struct net *ip_tunnel_get_link_net(const struct net_device *dev) 1033 { 1034 struct ip_tunnel *tunnel = netdev_priv(dev); 1035 1036 return tunnel->net; 1037 } 1038 EXPORT_SYMBOL(ip_tunnel_get_link_net); 1039 1040 int ip_tunnel_get_iflink(const struct net_device *dev) 1041 { 1042 struct ip_tunnel *tunnel = netdev_priv(dev); 1043 1044 return tunnel->parms.link; 1045 } 1046 EXPORT_SYMBOL(ip_tunnel_get_iflink); 1047 1048 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 1049 struct rtnl_link_ops *ops, char *devname) 1050 { 1051 struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id); 1052 struct ip_tunnel_parm parms; 1053 unsigned int i; 1054 1055 itn->rtnl_link_ops = ops; 1056 for (i = 0; i < IP_TNL_HASH_SIZE; i++) 1057 INIT_HLIST_HEAD(&itn->tunnels[i]); 1058 1059 if (!ops || !net_has_fallback_tunnels(net)) { 1060 struct ip_tunnel_net *it_init_net; 1061 1062 it_init_net = net_generic(&init_net, ip_tnl_net_id); 1063 itn->type = it_init_net->type; 1064 itn->fb_tunnel_dev = NULL; 1065 return 0; 1066 } 1067 1068 memset(&parms, 0, sizeof(parms)); 1069 if (devname) 1070 strlcpy(parms.name, devname, IFNAMSIZ); 1071 1072 rtnl_lock(); 1073 itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); 1074 /* FB netdevice is special: we have one, and only one per netns. 1075 * Allowing to move it to another netns is clearly unsafe. 1076 */ 1077 if (!IS_ERR(itn->fb_tunnel_dev)) { 1078 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1079 itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev); 1080 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev)); 1081 itn->type = itn->fb_tunnel_dev->type; 1082 } 1083 rtnl_unlock(); 1084 1085 return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev); 1086 } 1087 EXPORT_SYMBOL_GPL(ip_tunnel_init_net); 1088 1089 static void ip_tunnel_destroy(struct net *net, struct ip_tunnel_net *itn, 1090 struct list_head *head, 1091 struct rtnl_link_ops *ops) 1092 { 1093 struct net_device *dev, *aux; 1094 int h; 1095 1096 for_each_netdev_safe(net, dev, aux) 1097 if (dev->rtnl_link_ops == ops) 1098 unregister_netdevice_queue(dev, head); 1099 1100 for (h = 0; h < IP_TNL_HASH_SIZE; h++) { 1101 struct ip_tunnel *t; 1102 struct hlist_node *n; 1103 struct hlist_head *thead = &itn->tunnels[h]; 1104 1105 hlist_for_each_entry_safe(t, n, thead, hash_node) 1106 /* If dev is in the same netns, it has already 1107 * been added to the list by the previous loop. 1108 */ 1109 if (!net_eq(dev_net(t->dev), net)) 1110 unregister_netdevice_queue(t->dev, head); 1111 } 1112 } 1113 1114 void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id, 1115 struct rtnl_link_ops *ops) 1116 { 1117 struct ip_tunnel_net *itn; 1118 struct net *net; 1119 LIST_HEAD(list); 1120 1121 rtnl_lock(); 1122 list_for_each_entry(net, net_list, exit_list) { 1123 itn = net_generic(net, id); 1124 ip_tunnel_destroy(net, itn, &list, ops); 1125 } 1126 unregister_netdevice_many(&list); 1127 rtnl_unlock(); 1128 } 1129 EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets); 1130 1131 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 1132 struct ip_tunnel_parm *p, __u32 fwmark) 1133 { 1134 struct ip_tunnel *nt; 1135 struct net *net = dev_net(dev); 1136 struct ip_tunnel_net *itn; 1137 int mtu; 1138 int err; 1139 1140 nt = netdev_priv(dev); 1141 itn = net_generic(net, nt->ip_tnl_net_id); 1142 1143 if (nt->collect_md) { 1144 if (rtnl_dereference(itn->collect_md_tun)) 1145 return -EEXIST; 1146 } else { 1147 if (ip_tunnel_find(itn, p, dev->type)) 1148 return -EEXIST; 1149 } 1150 1151 nt->net = net; 1152 nt->parms = *p; 1153 nt->fwmark = fwmark; 1154 err = register_netdevice(dev); 1155 if (err) 1156 goto err_register_netdevice; 1157 1158 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) 1159 eth_hw_addr_random(dev); 1160 1161 mtu = ip_tunnel_bind_dev(dev); 1162 if (tb[IFLA_MTU]) { 1163 unsigned int max = IP_MAX_MTU - dev->hard_header_len - nt->hlen; 1164 1165 mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, 1166 (unsigned int)(max - sizeof(struct iphdr))); 1167 } 1168 1169 err = dev_set_mtu(dev, mtu); 1170 if (err) 1171 goto err_dev_set_mtu; 1172 1173 ip_tunnel_add(itn, nt); 1174 return 0; 1175 1176 err_dev_set_mtu: 1177 unregister_netdevice(dev); 1178 err_register_netdevice: 1179 return err; 1180 } 1181 EXPORT_SYMBOL_GPL(ip_tunnel_newlink); 1182 1183 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 1184 struct ip_tunnel_parm *p, __u32 fwmark) 1185 { 1186 struct ip_tunnel *t; 1187 struct ip_tunnel *tunnel = netdev_priv(dev); 1188 struct net *net = tunnel->net; 1189 struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id); 1190 1191 if (dev == itn->fb_tunnel_dev) 1192 return -EINVAL; 1193 1194 t = ip_tunnel_find(itn, p, dev->type); 1195 1196 if (t) { 1197 if (t->dev != dev) 1198 return -EEXIST; 1199 } else { 1200 t = tunnel; 1201 1202 if (dev->type != ARPHRD_ETHER) { 1203 unsigned int nflags = 0; 1204 1205 if (ipv4_is_multicast(p->iph.daddr)) 1206 nflags = IFF_BROADCAST; 1207 else if (p->iph.daddr) 1208 nflags = IFF_POINTOPOINT; 1209 1210 if ((dev->flags ^ nflags) & 1211 (IFF_POINTOPOINT | IFF_BROADCAST)) 1212 return -EINVAL; 1213 } 1214 } 1215 1216 ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU], fwmark); 1217 return 0; 1218 } 1219 EXPORT_SYMBOL_GPL(ip_tunnel_changelink); 1220 1221 int ip_tunnel_init(struct net_device *dev) 1222 { 1223 struct ip_tunnel *tunnel = netdev_priv(dev); 1224 struct iphdr *iph = &tunnel->parms.iph; 1225 int err; 1226 1227 dev->needs_free_netdev = true; 1228 dev->priv_destructor = ip_tunnel_dev_free; 1229 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1230 if (!dev->tstats) 1231 return -ENOMEM; 1232 1233 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); 1234 if (err) { 1235 free_percpu(dev->tstats); 1236 return err; 1237 } 1238 1239 err = gro_cells_init(&tunnel->gro_cells, dev); 1240 if (err) { 1241 dst_cache_destroy(&tunnel->dst_cache); 1242 free_percpu(dev->tstats); 1243 return err; 1244 } 1245 1246 tunnel->dev = dev; 1247 tunnel->net = dev_net(dev); 1248 strcpy(tunnel->parms.name, dev->name); 1249 iph->version = 4; 1250 iph->ihl = 5; 1251 1252 if (tunnel->collect_md) { 1253 dev->features |= NETIF_F_NETNS_LOCAL; 1254 netif_keep_dst(dev); 1255 } 1256 return 0; 1257 } 1258 EXPORT_SYMBOL_GPL(ip_tunnel_init); 1259 1260 void ip_tunnel_uninit(struct net_device *dev) 1261 { 1262 struct ip_tunnel *tunnel = netdev_priv(dev); 1263 struct net *net = tunnel->net; 1264 struct ip_tunnel_net *itn; 1265 1266 itn = net_generic(net, tunnel->ip_tnl_net_id); 1267 /* fb_tunnel_dev will be unregisted in net-exit call. */ 1268 if (itn->fb_tunnel_dev != dev) 1269 ip_tunnel_del(itn, netdev_priv(dev)); 1270 1271 dst_cache_reset(&tunnel->dst_cache); 1272 } 1273 EXPORT_SYMBOL_GPL(ip_tunnel_uninit); 1274 1275 /* Do least required initialization, rest of init is done in tunnel_init call */ 1276 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id) 1277 { 1278 struct ip_tunnel *tunnel = netdev_priv(dev); 1279 tunnel->ip_tnl_net_id = net_id; 1280 } 1281 EXPORT_SYMBOL_GPL(ip_tunnel_setup); 1282 1283 MODULE_LICENSE("GPL"); 1284