1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (c) 2013 Nicira, Inc. 4 */ 5 6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 7 8 #include <linux/capability.h> 9 #include <linux/module.h> 10 #include <linux/types.h> 11 #include <linux/kernel.h> 12 #include <linux/slab.h> 13 #include <linux/uaccess.h> 14 #include <linux/skbuff.h> 15 #include <linux/netdevice.h> 16 #include <linux/in.h> 17 #include <linux/tcp.h> 18 #include <linux/udp.h> 19 #include <linux/if_arp.h> 20 #include <linux/init.h> 21 #include <linux/in6.h> 22 #include <linux/inetdevice.h> 23 #include <linux/igmp.h> 24 #include <linux/netfilter_ipv4.h> 25 #include <linux/etherdevice.h> 26 #include <linux/if_ether.h> 27 #include <linux/if_vlan.h> 28 #include <linux/rculist.h> 29 #include <linux/err.h> 30 31 #include <net/sock.h> 32 #include <net/ip.h> 33 #include <net/icmp.h> 34 #include <net/protocol.h> 35 #include <net/ip_tunnels.h> 36 #include <net/arp.h> 37 #include <net/checksum.h> 38 #include <net/dsfield.h> 39 #include <net/inet_ecn.h> 40 #include <net/xfrm.h> 41 #include <net/net_namespace.h> 42 #include <net/netns/generic.h> 43 #include <net/rtnetlink.h> 44 #include <net/udp.h> 45 #include <net/dst_metadata.h> 46 47 #if IS_ENABLED(CONFIG_IPV6) 48 #include <net/ipv6.h> 49 #include <net/ip6_fib.h> 50 #include <net/ip6_route.h> 51 #endif 52 53 static unsigned int ip_tunnel_hash(__be32 key, __be32 remote) 54 { 55 return hash_32((__force u32)key ^ (__force u32)remote, 56 IP_TNL_HASH_BITS); 57 } 58 59 static bool ip_tunnel_key_match(const struct ip_tunnel_parm *p, 60 __be16 flags, __be32 key) 61 { 62 if (p->i_flags & TUNNEL_KEY) { 63 if (flags & TUNNEL_KEY) 64 return key == p->i_key; 65 else 66 /* key expected, none present */ 67 return false; 68 } else 69 return !(flags & TUNNEL_KEY); 70 } 71 72 /* Fallback tunnel: no source, no destination, no key, no options 73 74 Tunnel hash table: 75 We require exact key match i.e. if a key is present in packet 76 it will match only tunnel with the same key; if it is not present, 77 it will match only keyless tunnel. 78 79 All keysless packets, if not matched configured keyless tunnels 80 will match fallback tunnel. 81 Given src, dst and key, find appropriate for input tunnel. 82 */ 83 struct ip_tunnel *ip_tunnel_lookup(struct ip_tunnel_net *itn, 84 int link, __be16 flags, 85 __be32 remote, __be32 local, 86 __be32 key) 87 { 88 struct ip_tunnel *t, *cand = NULL; 89 struct hlist_head *head; 90 struct net_device *ndev; 91 unsigned int hash; 92 93 hash = ip_tunnel_hash(key, remote); 94 head = &itn->tunnels[hash]; 95 96 hlist_for_each_entry_rcu(t, head, hash_node) { 97 if (local != t->parms.iph.saddr || 98 remote != t->parms.iph.daddr || 99 !(t->dev->flags & IFF_UP)) 100 continue; 101 102 if (!ip_tunnel_key_match(&t->parms, flags, key)) 103 continue; 104 105 if (t->parms.link == link) 106 return t; 107 else 108 cand = t; 109 } 110 111 hlist_for_each_entry_rcu(t, head, hash_node) { 112 if (remote != t->parms.iph.daddr || 113 t->parms.iph.saddr != 0 || 114 !(t->dev->flags & IFF_UP)) 115 continue; 116 117 if (!ip_tunnel_key_match(&t->parms, flags, key)) 118 continue; 119 120 if (t->parms.link == link) 121 return t; 122 else if (!cand) 123 cand = t; 124 } 125 126 hash = ip_tunnel_hash(key, 0); 127 head = &itn->tunnels[hash]; 128 129 hlist_for_each_entry_rcu(t, head, hash_node) { 130 if ((local != t->parms.iph.saddr || t->parms.iph.daddr != 0) && 131 (local != t->parms.iph.daddr || !ipv4_is_multicast(local))) 132 continue; 133 134 if (!(t->dev->flags & IFF_UP)) 135 continue; 136 137 if (!ip_tunnel_key_match(&t->parms, flags, key)) 138 continue; 139 140 if (t->parms.link == link) 141 return t; 142 else if (!cand) 143 cand = t; 144 } 145 146 hlist_for_each_entry_rcu(t, head, hash_node) { 147 if ((!(flags & TUNNEL_NO_KEY) && t->parms.i_key != key) || 148 t->parms.iph.saddr != 0 || 149 t->parms.iph.daddr != 0 || 150 !(t->dev->flags & IFF_UP)) 151 continue; 152 153 if (t->parms.link == link) 154 return t; 155 else if (!cand) 156 cand = t; 157 } 158 159 if (cand) 160 return cand; 161 162 t = rcu_dereference(itn->collect_md_tun); 163 if (t && t->dev->flags & IFF_UP) 164 return t; 165 166 ndev = READ_ONCE(itn->fb_tunnel_dev); 167 if (ndev && ndev->flags & IFF_UP) 168 return netdev_priv(ndev); 169 170 return NULL; 171 } 172 EXPORT_SYMBOL_GPL(ip_tunnel_lookup); 173 174 static struct hlist_head *ip_bucket(struct ip_tunnel_net *itn, 175 struct ip_tunnel_parm *parms) 176 { 177 unsigned int h; 178 __be32 remote; 179 __be32 i_key = parms->i_key; 180 181 if (parms->iph.daddr && !ipv4_is_multicast(parms->iph.daddr)) 182 remote = parms->iph.daddr; 183 else 184 remote = 0; 185 186 if (!(parms->i_flags & TUNNEL_KEY) && (parms->i_flags & VTI_ISVTI)) 187 i_key = 0; 188 189 h = ip_tunnel_hash(i_key, remote); 190 return &itn->tunnels[h]; 191 } 192 193 static void ip_tunnel_add(struct ip_tunnel_net *itn, struct ip_tunnel *t) 194 { 195 struct hlist_head *head = ip_bucket(itn, &t->parms); 196 197 if (t->collect_md) 198 rcu_assign_pointer(itn->collect_md_tun, t); 199 hlist_add_head_rcu(&t->hash_node, head); 200 } 201 202 static void ip_tunnel_del(struct ip_tunnel_net *itn, struct ip_tunnel *t) 203 { 204 if (t->collect_md) 205 rcu_assign_pointer(itn->collect_md_tun, NULL); 206 hlist_del_init_rcu(&t->hash_node); 207 } 208 209 static struct ip_tunnel *ip_tunnel_find(struct ip_tunnel_net *itn, 210 struct ip_tunnel_parm *parms, 211 int type) 212 { 213 __be32 remote = parms->iph.daddr; 214 __be32 local = parms->iph.saddr; 215 __be32 key = parms->i_key; 216 __be16 flags = parms->i_flags; 217 int link = parms->link; 218 struct ip_tunnel *t = NULL; 219 struct hlist_head *head = ip_bucket(itn, parms); 220 221 hlist_for_each_entry_rcu(t, head, hash_node) { 222 if (local == t->parms.iph.saddr && 223 remote == t->parms.iph.daddr && 224 link == t->parms.link && 225 type == t->dev->type && 226 ip_tunnel_key_match(&t->parms, flags, key)) 227 break; 228 } 229 return t; 230 } 231 232 static struct net_device *__ip_tunnel_create(struct net *net, 233 const struct rtnl_link_ops *ops, 234 struct ip_tunnel_parm *parms) 235 { 236 int err; 237 struct ip_tunnel *tunnel; 238 struct net_device *dev; 239 char name[IFNAMSIZ]; 240 241 err = -E2BIG; 242 if (parms->name[0]) { 243 if (!dev_valid_name(parms->name)) 244 goto failed; 245 strlcpy(name, parms->name, IFNAMSIZ); 246 } else { 247 if (strlen(ops->kind) > (IFNAMSIZ - 3)) 248 goto failed; 249 strcpy(name, ops->kind); 250 strcat(name, "%d"); 251 } 252 253 ASSERT_RTNL(); 254 dev = alloc_netdev(ops->priv_size, name, NET_NAME_UNKNOWN, ops->setup); 255 if (!dev) { 256 err = -ENOMEM; 257 goto failed; 258 } 259 dev_net_set(dev, net); 260 261 dev->rtnl_link_ops = ops; 262 263 tunnel = netdev_priv(dev); 264 tunnel->parms = *parms; 265 tunnel->net = net; 266 267 err = register_netdevice(dev); 268 if (err) 269 goto failed_free; 270 271 return dev; 272 273 failed_free: 274 free_netdev(dev); 275 failed: 276 return ERR_PTR(err); 277 } 278 279 static int ip_tunnel_bind_dev(struct net_device *dev) 280 { 281 struct net_device *tdev = NULL; 282 struct ip_tunnel *tunnel = netdev_priv(dev); 283 const struct iphdr *iph; 284 int hlen = LL_MAX_HEADER; 285 int mtu = ETH_DATA_LEN; 286 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 287 288 iph = &tunnel->parms.iph; 289 290 /* Guess output device to choose reasonable mtu and needed_headroom */ 291 if (iph->daddr) { 292 struct flowi4 fl4; 293 struct rtable *rt; 294 295 ip_tunnel_init_flow(&fl4, iph->protocol, iph->daddr, 296 iph->saddr, tunnel->parms.o_key, 297 RT_TOS(iph->tos), tunnel->parms.link, 298 tunnel->fwmark, 0); 299 rt = ip_route_output_key(tunnel->net, &fl4); 300 301 if (!IS_ERR(rt)) { 302 tdev = rt->dst.dev; 303 ip_rt_put(rt); 304 } 305 if (dev->type != ARPHRD_ETHER) 306 dev->flags |= IFF_POINTOPOINT; 307 308 dst_cache_reset(&tunnel->dst_cache); 309 } 310 311 if (!tdev && tunnel->parms.link) 312 tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link); 313 314 if (tdev) { 315 hlen = tdev->hard_header_len + tdev->needed_headroom; 316 mtu = min(tdev->mtu, IP_MAX_MTU); 317 } 318 319 dev->needed_headroom = t_hlen + hlen; 320 mtu -= t_hlen + (dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0); 321 322 if (mtu < IPV4_MIN_MTU) 323 mtu = IPV4_MIN_MTU; 324 325 return mtu; 326 } 327 328 static struct ip_tunnel *ip_tunnel_create(struct net *net, 329 struct ip_tunnel_net *itn, 330 struct ip_tunnel_parm *parms) 331 { 332 struct ip_tunnel *nt; 333 struct net_device *dev; 334 int t_hlen; 335 int mtu; 336 int err; 337 338 dev = __ip_tunnel_create(net, itn->rtnl_link_ops, parms); 339 if (IS_ERR(dev)) 340 return ERR_CAST(dev); 341 342 mtu = ip_tunnel_bind_dev(dev); 343 err = dev_set_mtu(dev, mtu); 344 if (err) 345 goto err_dev_set_mtu; 346 347 nt = netdev_priv(dev); 348 t_hlen = nt->hlen + sizeof(struct iphdr); 349 dev->min_mtu = ETH_MIN_MTU; 350 dev->max_mtu = IP_MAX_MTU - t_hlen; 351 if (dev->type == ARPHRD_ETHER) 352 dev->max_mtu -= dev->hard_header_len; 353 354 ip_tunnel_add(itn, nt); 355 return nt; 356 357 err_dev_set_mtu: 358 unregister_netdevice(dev); 359 return ERR_PTR(err); 360 } 361 362 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, 363 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, 364 bool log_ecn_error) 365 { 366 const struct iphdr *iph = ip_hdr(skb); 367 int err; 368 369 #ifdef CONFIG_NET_IPGRE_BROADCAST 370 if (ipv4_is_multicast(iph->daddr)) { 371 tunnel->dev->stats.multicast++; 372 skb->pkt_type = PACKET_BROADCAST; 373 } 374 #endif 375 376 if ((!(tpi->flags&TUNNEL_CSUM) && (tunnel->parms.i_flags&TUNNEL_CSUM)) || 377 ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) { 378 tunnel->dev->stats.rx_crc_errors++; 379 tunnel->dev->stats.rx_errors++; 380 goto drop; 381 } 382 383 if (tunnel->parms.i_flags&TUNNEL_SEQ) { 384 if (!(tpi->flags&TUNNEL_SEQ) || 385 (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) { 386 tunnel->dev->stats.rx_fifo_errors++; 387 tunnel->dev->stats.rx_errors++; 388 goto drop; 389 } 390 tunnel->i_seqno = ntohl(tpi->seq) + 1; 391 } 392 393 skb_set_network_header(skb, (tunnel->dev->type == ARPHRD_ETHER) ? ETH_HLEN : 0); 394 395 err = IP_ECN_decapsulate(iph, skb); 396 if (unlikely(err)) { 397 if (log_ecn_error) 398 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 399 &iph->saddr, iph->tos); 400 if (err > 1) { 401 ++tunnel->dev->stats.rx_frame_errors; 402 ++tunnel->dev->stats.rx_errors; 403 goto drop; 404 } 405 } 406 407 dev_sw_netstats_rx_add(tunnel->dev, skb->len); 408 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev))); 409 410 if (tunnel->dev->type == ARPHRD_ETHER) { 411 skb->protocol = eth_type_trans(skb, tunnel->dev); 412 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN); 413 } else { 414 skb->dev = tunnel->dev; 415 } 416 417 if (tun_dst) 418 skb_dst_set(skb, (struct dst_entry *)tun_dst); 419 420 gro_cells_receive(&tunnel->gro_cells, skb); 421 return 0; 422 423 drop: 424 if (tun_dst) 425 dst_release((struct dst_entry *)tun_dst); 426 kfree_skb(skb); 427 return 0; 428 } 429 EXPORT_SYMBOL_GPL(ip_tunnel_rcv); 430 431 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops, 432 unsigned int num) 433 { 434 if (num >= MAX_IPTUN_ENCAP_OPS) 435 return -ERANGE; 436 437 return !cmpxchg((const struct ip_tunnel_encap_ops **) 438 &iptun_encaps[num], 439 NULL, ops) ? 0 : -1; 440 } 441 EXPORT_SYMBOL(ip_tunnel_encap_add_ops); 442 443 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops, 444 unsigned int num) 445 { 446 int ret; 447 448 if (num >= MAX_IPTUN_ENCAP_OPS) 449 return -ERANGE; 450 451 ret = (cmpxchg((const struct ip_tunnel_encap_ops **) 452 &iptun_encaps[num], 453 ops, NULL) == ops) ? 0 : -1; 454 455 synchronize_net(); 456 457 return ret; 458 } 459 EXPORT_SYMBOL(ip_tunnel_encap_del_ops); 460 461 int ip_tunnel_encap_setup(struct ip_tunnel *t, 462 struct ip_tunnel_encap *ipencap) 463 { 464 int hlen; 465 466 memset(&t->encap, 0, sizeof(t->encap)); 467 468 hlen = ip_encap_hlen(ipencap); 469 if (hlen < 0) 470 return hlen; 471 472 t->encap.type = ipencap->type; 473 t->encap.sport = ipencap->sport; 474 t->encap.dport = ipencap->dport; 475 t->encap.flags = ipencap->flags; 476 477 t->encap_hlen = hlen; 478 t->hlen = t->encap_hlen + t->tun_hlen; 479 480 return 0; 481 } 482 EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup); 483 484 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, 485 struct rtable *rt, __be16 df, 486 const struct iphdr *inner_iph, 487 int tunnel_hlen, __be32 dst, bool md) 488 { 489 struct ip_tunnel *tunnel = netdev_priv(dev); 490 int pkt_size; 491 int mtu; 492 493 tunnel_hlen = md ? tunnel_hlen : tunnel->hlen; 494 pkt_size = skb->len - tunnel_hlen; 495 pkt_size -= dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0; 496 497 if (df) { 498 mtu = dst_mtu(&rt->dst) - (sizeof(struct iphdr) + tunnel_hlen); 499 mtu -= dev->type == ARPHRD_ETHER ? dev->hard_header_len : 0; 500 } else { 501 mtu = skb_valid_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; 502 } 503 504 if (skb_valid_dst(skb)) 505 skb_dst_update_pmtu_no_confirm(skb, mtu); 506 507 if (skb->protocol == htons(ETH_P_IP)) { 508 if (!skb_is_gso(skb) && 509 (inner_iph->frag_off & htons(IP_DF)) && 510 mtu < pkt_size) { 511 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 512 return -E2BIG; 513 } 514 } 515 #if IS_ENABLED(CONFIG_IPV6) 516 else if (skb->protocol == htons(ETH_P_IPV6)) { 517 struct rt6_info *rt6; 518 __be32 daddr; 519 520 rt6 = skb_valid_dst(skb) ? (struct rt6_info *)skb_dst(skb) : 521 NULL; 522 daddr = md ? dst : tunnel->parms.iph.daddr; 523 524 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && 525 mtu >= IPV6_MIN_MTU) { 526 if ((daddr && !ipv4_is_multicast(daddr)) || 527 rt6->rt6i_dst.plen == 128) { 528 rt6->rt6i_flags |= RTF_MODIFIED; 529 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); 530 } 531 } 532 533 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && 534 mtu < pkt_size) { 535 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 536 return -E2BIG; 537 } 538 } 539 #endif 540 return 0; 541 } 542 543 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 544 u8 proto, int tunnel_hlen) 545 { 546 struct ip_tunnel *tunnel = netdev_priv(dev); 547 u32 headroom = sizeof(struct iphdr); 548 struct ip_tunnel_info *tun_info; 549 const struct ip_tunnel_key *key; 550 const struct iphdr *inner_iph; 551 struct rtable *rt = NULL; 552 struct flowi4 fl4; 553 __be16 df = 0; 554 u8 tos, ttl; 555 bool use_cache; 556 557 tun_info = skb_tunnel_info(skb); 558 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 559 ip_tunnel_info_af(tun_info) != AF_INET)) 560 goto tx_error; 561 key = &tun_info->key; 562 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 563 inner_iph = (const struct iphdr *)skb_inner_network_header(skb); 564 tos = key->tos; 565 if (tos == 1) { 566 if (skb->protocol == htons(ETH_P_IP)) 567 tos = inner_iph->tos; 568 else if (skb->protocol == htons(ETH_P_IPV6)) 569 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); 570 } 571 ip_tunnel_init_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src, 572 tunnel_id_to_key32(key->tun_id), RT_TOS(tos), 573 0, skb->mark, skb_get_hash(skb)); 574 if (tunnel->encap.type != TUNNEL_ENCAP_NONE) 575 goto tx_error; 576 577 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 578 if (use_cache) 579 rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl4.saddr); 580 if (!rt) { 581 rt = ip_route_output_key(tunnel->net, &fl4); 582 if (IS_ERR(rt)) { 583 dev->stats.tx_carrier_errors++; 584 goto tx_error; 585 } 586 if (use_cache) 587 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 588 fl4.saddr); 589 } 590 if (rt->dst.dev == dev) { 591 ip_rt_put(rt); 592 dev->stats.collisions++; 593 goto tx_error; 594 } 595 596 if (key->tun_flags & TUNNEL_DONT_FRAGMENT) 597 df = htons(IP_DF); 598 if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, tunnel_hlen, 599 key->u.ipv4.dst, true)) { 600 ip_rt_put(rt); 601 goto tx_error; 602 } 603 604 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 605 ttl = key->ttl; 606 if (ttl == 0) { 607 if (skb->protocol == htons(ETH_P_IP)) 608 ttl = inner_iph->ttl; 609 else if (skb->protocol == htons(ETH_P_IPV6)) 610 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 611 else 612 ttl = ip4_dst_hoplimit(&rt->dst); 613 } 614 615 headroom += LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len; 616 if (headroom > dev->needed_headroom) 617 dev->needed_headroom = headroom; 618 619 if (skb_cow_head(skb, dev->needed_headroom)) { 620 ip_rt_put(rt); 621 goto tx_dropped; 622 } 623 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, proto, tos, ttl, 624 df, !net_eq(tunnel->net, dev_net(dev))); 625 return; 626 tx_error: 627 dev->stats.tx_errors++; 628 goto kfree; 629 tx_dropped: 630 dev->stats.tx_dropped++; 631 kfree: 632 kfree_skb(skb); 633 } 634 EXPORT_SYMBOL_GPL(ip_md_tunnel_xmit); 635 636 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 637 const struct iphdr *tnl_params, u8 protocol) 638 { 639 struct ip_tunnel *tunnel = netdev_priv(dev); 640 struct ip_tunnel_info *tun_info = NULL; 641 const struct iphdr *inner_iph; 642 unsigned int max_headroom; /* The extra header space needed */ 643 struct rtable *rt = NULL; /* Route to the other host */ 644 bool use_cache = false; 645 struct flowi4 fl4; 646 bool md = false; 647 bool connected; 648 u8 tos, ttl; 649 __be32 dst; 650 __be16 df; 651 652 inner_iph = (const struct iphdr *)skb_inner_network_header(skb); 653 connected = (tunnel->parms.iph.daddr != 0); 654 655 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 656 657 dst = tnl_params->daddr; 658 if (dst == 0) { 659 /* NBMA tunnel */ 660 661 if (!skb_dst(skb)) { 662 dev->stats.tx_fifo_errors++; 663 goto tx_error; 664 } 665 666 tun_info = skb_tunnel_info(skb); 667 if (tun_info && (tun_info->mode & IP_TUNNEL_INFO_TX) && 668 ip_tunnel_info_af(tun_info) == AF_INET && 669 tun_info->key.u.ipv4.dst) { 670 dst = tun_info->key.u.ipv4.dst; 671 md = true; 672 connected = true; 673 } 674 else if (skb->protocol == htons(ETH_P_IP)) { 675 rt = skb_rtable(skb); 676 dst = rt_nexthop(rt, inner_iph->daddr); 677 } 678 #if IS_ENABLED(CONFIG_IPV6) 679 else if (skb->protocol == htons(ETH_P_IPV6)) { 680 const struct in6_addr *addr6; 681 struct neighbour *neigh; 682 bool do_tx_error_icmp; 683 int addr_type; 684 685 neigh = dst_neigh_lookup(skb_dst(skb), 686 &ipv6_hdr(skb)->daddr); 687 if (!neigh) 688 goto tx_error; 689 690 addr6 = (const struct in6_addr *)&neigh->primary_key; 691 addr_type = ipv6_addr_type(addr6); 692 693 if (addr_type == IPV6_ADDR_ANY) { 694 addr6 = &ipv6_hdr(skb)->daddr; 695 addr_type = ipv6_addr_type(addr6); 696 } 697 698 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 699 do_tx_error_icmp = true; 700 else { 701 do_tx_error_icmp = false; 702 dst = addr6->s6_addr32[3]; 703 } 704 neigh_release(neigh); 705 if (do_tx_error_icmp) 706 goto tx_error_icmp; 707 } 708 #endif 709 else 710 goto tx_error; 711 712 if (!md) 713 connected = false; 714 } 715 716 tos = tnl_params->tos; 717 if (tos & 0x1) { 718 tos &= ~0x1; 719 if (skb->protocol == htons(ETH_P_IP)) { 720 tos = inner_iph->tos; 721 connected = false; 722 } else if (skb->protocol == htons(ETH_P_IPV6)) { 723 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); 724 connected = false; 725 } 726 } 727 728 ip_tunnel_init_flow(&fl4, protocol, dst, tnl_params->saddr, 729 tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link, 730 tunnel->fwmark, skb_get_hash(skb)); 731 732 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) 733 goto tx_error; 734 735 if (connected && md) { 736 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 737 if (use_cache) 738 rt = dst_cache_get_ip4(&tun_info->dst_cache, 739 &fl4.saddr); 740 } else { 741 rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, 742 &fl4.saddr) : NULL; 743 } 744 745 if (!rt) { 746 rt = ip_route_output_key(tunnel->net, &fl4); 747 748 if (IS_ERR(rt)) { 749 dev->stats.tx_carrier_errors++; 750 goto tx_error; 751 } 752 if (use_cache) 753 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 754 fl4.saddr); 755 else if (!md && connected) 756 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, 757 fl4.saddr); 758 } 759 760 if (rt->dst.dev == dev) { 761 ip_rt_put(rt); 762 dev->stats.collisions++; 763 goto tx_error; 764 } 765 766 df = tnl_params->frag_off; 767 if (skb->protocol == htons(ETH_P_IP) && !tunnel->ignore_df) 768 df |= (inner_iph->frag_off & htons(IP_DF)); 769 770 if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, 0, 0, false)) { 771 ip_rt_put(rt); 772 goto tx_error; 773 } 774 775 if (tunnel->err_count > 0) { 776 if (time_before(jiffies, 777 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 778 tunnel->err_count--; 779 780 dst_link_failure(skb); 781 } else 782 tunnel->err_count = 0; 783 } 784 785 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 786 ttl = tnl_params->ttl; 787 if (ttl == 0) { 788 if (skb->protocol == htons(ETH_P_IP)) 789 ttl = inner_iph->ttl; 790 #if IS_ENABLED(CONFIG_IPV6) 791 else if (skb->protocol == htons(ETH_P_IPV6)) 792 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 793 #endif 794 else 795 ttl = ip4_dst_hoplimit(&rt->dst); 796 } 797 798 max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) 799 + rt->dst.header_len + ip_encap_hlen(&tunnel->encap); 800 if (max_headroom > dev->needed_headroom) 801 dev->needed_headroom = max_headroom; 802 803 if (skb_cow_head(skb, dev->needed_headroom)) { 804 ip_rt_put(rt); 805 dev->stats.tx_dropped++; 806 kfree_skb(skb); 807 return; 808 } 809 810 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, 811 df, !net_eq(tunnel->net, dev_net(dev))); 812 return; 813 814 #if IS_ENABLED(CONFIG_IPV6) 815 tx_error_icmp: 816 dst_link_failure(skb); 817 #endif 818 tx_error: 819 dev->stats.tx_errors++; 820 kfree_skb(skb); 821 } 822 EXPORT_SYMBOL_GPL(ip_tunnel_xmit); 823 824 static void ip_tunnel_update(struct ip_tunnel_net *itn, 825 struct ip_tunnel *t, 826 struct net_device *dev, 827 struct ip_tunnel_parm *p, 828 bool set_mtu, 829 __u32 fwmark) 830 { 831 ip_tunnel_del(itn, t); 832 t->parms.iph.saddr = p->iph.saddr; 833 t->parms.iph.daddr = p->iph.daddr; 834 t->parms.i_key = p->i_key; 835 t->parms.o_key = p->o_key; 836 if (dev->type != ARPHRD_ETHER) { 837 memcpy(dev->dev_addr, &p->iph.saddr, 4); 838 memcpy(dev->broadcast, &p->iph.daddr, 4); 839 } 840 ip_tunnel_add(itn, t); 841 842 t->parms.iph.ttl = p->iph.ttl; 843 t->parms.iph.tos = p->iph.tos; 844 t->parms.iph.frag_off = p->iph.frag_off; 845 846 if (t->parms.link != p->link || t->fwmark != fwmark) { 847 int mtu; 848 849 t->parms.link = p->link; 850 t->fwmark = fwmark; 851 mtu = ip_tunnel_bind_dev(dev); 852 if (set_mtu) 853 dev->mtu = mtu; 854 } 855 dst_cache_reset(&t->dst_cache); 856 netdev_state_change(dev); 857 } 858 859 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) 860 { 861 int err = 0; 862 struct ip_tunnel *t = netdev_priv(dev); 863 struct net *net = t->net; 864 struct ip_tunnel_net *itn = net_generic(net, t->ip_tnl_net_id); 865 866 switch (cmd) { 867 case SIOCGETTUNNEL: 868 if (dev == itn->fb_tunnel_dev) { 869 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 870 if (!t) 871 t = netdev_priv(dev); 872 } 873 memcpy(p, &t->parms, sizeof(*p)); 874 break; 875 876 case SIOCADDTUNNEL: 877 case SIOCCHGTUNNEL: 878 err = -EPERM; 879 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 880 goto done; 881 if (p->iph.ttl) 882 p->iph.frag_off |= htons(IP_DF); 883 if (!(p->i_flags & VTI_ISVTI)) { 884 if (!(p->i_flags & TUNNEL_KEY)) 885 p->i_key = 0; 886 if (!(p->o_flags & TUNNEL_KEY)) 887 p->o_key = 0; 888 } 889 890 t = ip_tunnel_find(itn, p, itn->type); 891 892 if (cmd == SIOCADDTUNNEL) { 893 if (!t) { 894 t = ip_tunnel_create(net, itn, p); 895 err = PTR_ERR_OR_ZERO(t); 896 break; 897 } 898 899 err = -EEXIST; 900 break; 901 } 902 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 903 if (t) { 904 if (t->dev != dev) { 905 err = -EEXIST; 906 break; 907 } 908 } else { 909 unsigned int nflags = 0; 910 911 if (ipv4_is_multicast(p->iph.daddr)) 912 nflags = IFF_BROADCAST; 913 else if (p->iph.daddr) 914 nflags = IFF_POINTOPOINT; 915 916 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { 917 err = -EINVAL; 918 break; 919 } 920 921 t = netdev_priv(dev); 922 } 923 } 924 925 if (t) { 926 err = 0; 927 ip_tunnel_update(itn, t, dev, p, true, 0); 928 } else { 929 err = -ENOENT; 930 } 931 break; 932 933 case SIOCDELTUNNEL: 934 err = -EPERM; 935 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 936 goto done; 937 938 if (dev == itn->fb_tunnel_dev) { 939 err = -ENOENT; 940 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 941 if (!t) 942 goto done; 943 err = -EPERM; 944 if (t == netdev_priv(itn->fb_tunnel_dev)) 945 goto done; 946 dev = t->dev; 947 } 948 unregister_netdevice(dev); 949 err = 0; 950 break; 951 952 default: 953 err = -EINVAL; 954 } 955 956 done: 957 return err; 958 } 959 EXPORT_SYMBOL_GPL(ip_tunnel_ctl); 960 961 int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 962 { 963 struct ip_tunnel_parm p; 964 int err; 965 966 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 967 return -EFAULT; 968 err = dev->netdev_ops->ndo_tunnel_ctl(dev, &p, cmd); 969 if (!err && copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 970 return -EFAULT; 971 return err; 972 } 973 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl); 974 975 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) 976 { 977 struct ip_tunnel *tunnel = netdev_priv(dev); 978 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 979 int max_mtu = IP_MAX_MTU - t_hlen; 980 981 if (dev->type == ARPHRD_ETHER) 982 max_mtu -= dev->hard_header_len; 983 984 if (new_mtu < ETH_MIN_MTU) 985 return -EINVAL; 986 987 if (new_mtu > max_mtu) { 988 if (strict) 989 return -EINVAL; 990 991 new_mtu = max_mtu; 992 } 993 994 dev->mtu = new_mtu; 995 return 0; 996 } 997 EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu); 998 999 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1000 { 1001 return __ip_tunnel_change_mtu(dev, new_mtu, true); 1002 } 1003 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu); 1004 1005 static void ip_tunnel_dev_free(struct net_device *dev) 1006 { 1007 struct ip_tunnel *tunnel = netdev_priv(dev); 1008 1009 gro_cells_destroy(&tunnel->gro_cells); 1010 dst_cache_destroy(&tunnel->dst_cache); 1011 free_percpu(dev->tstats); 1012 } 1013 1014 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) 1015 { 1016 struct ip_tunnel *tunnel = netdev_priv(dev); 1017 struct ip_tunnel_net *itn; 1018 1019 itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); 1020 1021 if (itn->fb_tunnel_dev != dev) { 1022 ip_tunnel_del(itn, netdev_priv(dev)); 1023 unregister_netdevice_queue(dev, head); 1024 } 1025 } 1026 EXPORT_SYMBOL_GPL(ip_tunnel_dellink); 1027 1028 struct net *ip_tunnel_get_link_net(const struct net_device *dev) 1029 { 1030 struct ip_tunnel *tunnel = netdev_priv(dev); 1031 1032 return tunnel->net; 1033 } 1034 EXPORT_SYMBOL(ip_tunnel_get_link_net); 1035 1036 int ip_tunnel_get_iflink(const struct net_device *dev) 1037 { 1038 struct ip_tunnel *tunnel = netdev_priv(dev); 1039 1040 return tunnel->parms.link; 1041 } 1042 EXPORT_SYMBOL(ip_tunnel_get_iflink); 1043 1044 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 1045 struct rtnl_link_ops *ops, char *devname) 1046 { 1047 struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id); 1048 struct ip_tunnel_parm parms; 1049 unsigned int i; 1050 1051 itn->rtnl_link_ops = ops; 1052 for (i = 0; i < IP_TNL_HASH_SIZE; i++) 1053 INIT_HLIST_HEAD(&itn->tunnels[i]); 1054 1055 if (!ops || !net_has_fallback_tunnels(net)) { 1056 struct ip_tunnel_net *it_init_net; 1057 1058 it_init_net = net_generic(&init_net, ip_tnl_net_id); 1059 itn->type = it_init_net->type; 1060 itn->fb_tunnel_dev = NULL; 1061 return 0; 1062 } 1063 1064 memset(&parms, 0, sizeof(parms)); 1065 if (devname) 1066 strlcpy(parms.name, devname, IFNAMSIZ); 1067 1068 rtnl_lock(); 1069 itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); 1070 /* FB netdevice is special: we have one, and only one per netns. 1071 * Allowing to move it to another netns is clearly unsafe. 1072 */ 1073 if (!IS_ERR(itn->fb_tunnel_dev)) { 1074 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1075 itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev); 1076 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev)); 1077 itn->type = itn->fb_tunnel_dev->type; 1078 } 1079 rtnl_unlock(); 1080 1081 return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev); 1082 } 1083 EXPORT_SYMBOL_GPL(ip_tunnel_init_net); 1084 1085 static void ip_tunnel_destroy(struct net *net, struct ip_tunnel_net *itn, 1086 struct list_head *head, 1087 struct rtnl_link_ops *ops) 1088 { 1089 struct net_device *dev, *aux; 1090 int h; 1091 1092 for_each_netdev_safe(net, dev, aux) 1093 if (dev->rtnl_link_ops == ops) 1094 unregister_netdevice_queue(dev, head); 1095 1096 for (h = 0; h < IP_TNL_HASH_SIZE; h++) { 1097 struct ip_tunnel *t; 1098 struct hlist_node *n; 1099 struct hlist_head *thead = &itn->tunnels[h]; 1100 1101 hlist_for_each_entry_safe(t, n, thead, hash_node) 1102 /* If dev is in the same netns, it has already 1103 * been added to the list by the previous loop. 1104 */ 1105 if (!net_eq(dev_net(t->dev), net)) 1106 unregister_netdevice_queue(t->dev, head); 1107 } 1108 } 1109 1110 void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id, 1111 struct rtnl_link_ops *ops) 1112 { 1113 struct ip_tunnel_net *itn; 1114 struct net *net; 1115 LIST_HEAD(list); 1116 1117 rtnl_lock(); 1118 list_for_each_entry(net, net_list, exit_list) { 1119 itn = net_generic(net, id); 1120 ip_tunnel_destroy(net, itn, &list, ops); 1121 } 1122 unregister_netdevice_many(&list); 1123 rtnl_unlock(); 1124 } 1125 EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets); 1126 1127 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 1128 struct ip_tunnel_parm *p, __u32 fwmark) 1129 { 1130 struct ip_tunnel *nt; 1131 struct net *net = dev_net(dev); 1132 struct ip_tunnel_net *itn; 1133 int mtu; 1134 int err; 1135 1136 nt = netdev_priv(dev); 1137 itn = net_generic(net, nt->ip_tnl_net_id); 1138 1139 if (nt->collect_md) { 1140 if (rtnl_dereference(itn->collect_md_tun)) 1141 return -EEXIST; 1142 } else { 1143 if (ip_tunnel_find(itn, p, dev->type)) 1144 return -EEXIST; 1145 } 1146 1147 nt->net = net; 1148 nt->parms = *p; 1149 nt->fwmark = fwmark; 1150 err = register_netdevice(dev); 1151 if (err) 1152 goto err_register_netdevice; 1153 1154 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) 1155 eth_hw_addr_random(dev); 1156 1157 mtu = ip_tunnel_bind_dev(dev); 1158 if (tb[IFLA_MTU]) { 1159 unsigned int max = IP_MAX_MTU - (nt->hlen + sizeof(struct iphdr)); 1160 1161 if (dev->type == ARPHRD_ETHER) 1162 max -= dev->hard_header_len; 1163 1164 mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, max); 1165 } 1166 1167 err = dev_set_mtu(dev, mtu); 1168 if (err) 1169 goto err_dev_set_mtu; 1170 1171 ip_tunnel_add(itn, nt); 1172 return 0; 1173 1174 err_dev_set_mtu: 1175 unregister_netdevice(dev); 1176 err_register_netdevice: 1177 return err; 1178 } 1179 EXPORT_SYMBOL_GPL(ip_tunnel_newlink); 1180 1181 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 1182 struct ip_tunnel_parm *p, __u32 fwmark) 1183 { 1184 struct ip_tunnel *t; 1185 struct ip_tunnel *tunnel = netdev_priv(dev); 1186 struct net *net = tunnel->net; 1187 struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id); 1188 1189 if (dev == itn->fb_tunnel_dev) 1190 return -EINVAL; 1191 1192 t = ip_tunnel_find(itn, p, dev->type); 1193 1194 if (t) { 1195 if (t->dev != dev) 1196 return -EEXIST; 1197 } else { 1198 t = tunnel; 1199 1200 if (dev->type != ARPHRD_ETHER) { 1201 unsigned int nflags = 0; 1202 1203 if (ipv4_is_multicast(p->iph.daddr)) 1204 nflags = IFF_BROADCAST; 1205 else if (p->iph.daddr) 1206 nflags = IFF_POINTOPOINT; 1207 1208 if ((dev->flags ^ nflags) & 1209 (IFF_POINTOPOINT | IFF_BROADCAST)) 1210 return -EINVAL; 1211 } 1212 } 1213 1214 ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU], fwmark); 1215 return 0; 1216 } 1217 EXPORT_SYMBOL_GPL(ip_tunnel_changelink); 1218 1219 int ip_tunnel_init(struct net_device *dev) 1220 { 1221 struct ip_tunnel *tunnel = netdev_priv(dev); 1222 struct iphdr *iph = &tunnel->parms.iph; 1223 int err; 1224 1225 dev->needs_free_netdev = true; 1226 dev->priv_destructor = ip_tunnel_dev_free; 1227 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1228 if (!dev->tstats) 1229 return -ENOMEM; 1230 1231 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); 1232 if (err) { 1233 free_percpu(dev->tstats); 1234 return err; 1235 } 1236 1237 err = gro_cells_init(&tunnel->gro_cells, dev); 1238 if (err) { 1239 dst_cache_destroy(&tunnel->dst_cache); 1240 free_percpu(dev->tstats); 1241 return err; 1242 } 1243 1244 tunnel->dev = dev; 1245 tunnel->net = dev_net(dev); 1246 strcpy(tunnel->parms.name, dev->name); 1247 iph->version = 4; 1248 iph->ihl = 5; 1249 1250 if (tunnel->collect_md) 1251 netif_keep_dst(dev); 1252 return 0; 1253 } 1254 EXPORT_SYMBOL_GPL(ip_tunnel_init); 1255 1256 void ip_tunnel_uninit(struct net_device *dev) 1257 { 1258 struct ip_tunnel *tunnel = netdev_priv(dev); 1259 struct net *net = tunnel->net; 1260 struct ip_tunnel_net *itn; 1261 1262 itn = net_generic(net, tunnel->ip_tnl_net_id); 1263 ip_tunnel_del(itn, netdev_priv(dev)); 1264 if (itn->fb_tunnel_dev == dev) 1265 WRITE_ONCE(itn->fb_tunnel_dev, NULL); 1266 1267 dst_cache_reset(&tunnel->dst_cache); 1268 } 1269 EXPORT_SYMBOL_GPL(ip_tunnel_uninit); 1270 1271 /* Do least required initialization, rest of init is done in tunnel_init call */ 1272 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id) 1273 { 1274 struct ip_tunnel *tunnel = netdev_priv(dev); 1275 tunnel->ip_tnl_net_id = net_id; 1276 } 1277 EXPORT_SYMBOL_GPL(ip_tunnel_setup); 1278 1279 MODULE_LICENSE("GPL"); 1280