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 __dev_addr_set(dev, &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_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 962 void __user *data, int cmd) 963 { 964 struct ip_tunnel_parm p; 965 int err; 966 967 if (copy_from_user(&p, data, sizeof(p))) 968 return -EFAULT; 969 err = dev->netdev_ops->ndo_tunnel_ctl(dev, &p, cmd); 970 if (!err && copy_to_user(data, &p, sizeof(p))) 971 return -EFAULT; 972 return err; 973 } 974 EXPORT_SYMBOL_GPL(ip_tunnel_siocdevprivate); 975 976 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) 977 { 978 struct ip_tunnel *tunnel = netdev_priv(dev); 979 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 980 int max_mtu = IP_MAX_MTU - t_hlen; 981 982 if (dev->type == ARPHRD_ETHER) 983 max_mtu -= dev->hard_header_len; 984 985 if (new_mtu < ETH_MIN_MTU) 986 return -EINVAL; 987 988 if (new_mtu > max_mtu) { 989 if (strict) 990 return -EINVAL; 991 992 new_mtu = max_mtu; 993 } 994 995 dev->mtu = new_mtu; 996 return 0; 997 } 998 EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu); 999 1000 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1001 { 1002 return __ip_tunnel_change_mtu(dev, new_mtu, true); 1003 } 1004 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu); 1005 1006 static void ip_tunnel_dev_free(struct net_device *dev) 1007 { 1008 struct ip_tunnel *tunnel = netdev_priv(dev); 1009 1010 gro_cells_destroy(&tunnel->gro_cells); 1011 dst_cache_destroy(&tunnel->dst_cache); 1012 free_percpu(dev->tstats); 1013 } 1014 1015 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) 1016 { 1017 struct ip_tunnel *tunnel = netdev_priv(dev); 1018 struct ip_tunnel_net *itn; 1019 1020 itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); 1021 1022 if (itn->fb_tunnel_dev != dev) { 1023 ip_tunnel_del(itn, netdev_priv(dev)); 1024 unregister_netdevice_queue(dev, head); 1025 } 1026 } 1027 EXPORT_SYMBOL_GPL(ip_tunnel_dellink); 1028 1029 struct net *ip_tunnel_get_link_net(const struct net_device *dev) 1030 { 1031 struct ip_tunnel *tunnel = netdev_priv(dev); 1032 1033 return tunnel->net; 1034 } 1035 EXPORT_SYMBOL(ip_tunnel_get_link_net); 1036 1037 int ip_tunnel_get_iflink(const struct net_device *dev) 1038 { 1039 struct ip_tunnel *tunnel = netdev_priv(dev); 1040 1041 return tunnel->parms.link; 1042 } 1043 EXPORT_SYMBOL(ip_tunnel_get_iflink); 1044 1045 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 1046 struct rtnl_link_ops *ops, char *devname) 1047 { 1048 struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id); 1049 struct ip_tunnel_parm parms; 1050 unsigned int i; 1051 1052 itn->rtnl_link_ops = ops; 1053 for (i = 0; i < IP_TNL_HASH_SIZE; i++) 1054 INIT_HLIST_HEAD(&itn->tunnels[i]); 1055 1056 if (!ops || !net_has_fallback_tunnels(net)) { 1057 struct ip_tunnel_net *it_init_net; 1058 1059 it_init_net = net_generic(&init_net, ip_tnl_net_id); 1060 itn->type = it_init_net->type; 1061 itn->fb_tunnel_dev = NULL; 1062 return 0; 1063 } 1064 1065 memset(&parms, 0, sizeof(parms)); 1066 if (devname) 1067 strlcpy(parms.name, devname, IFNAMSIZ); 1068 1069 rtnl_lock(); 1070 itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); 1071 /* FB netdevice is special: we have one, and only one per netns. 1072 * Allowing to move it to another netns is clearly unsafe. 1073 */ 1074 if (!IS_ERR(itn->fb_tunnel_dev)) { 1075 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1076 itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev); 1077 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev)); 1078 itn->type = itn->fb_tunnel_dev->type; 1079 } 1080 rtnl_unlock(); 1081 1082 return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev); 1083 } 1084 EXPORT_SYMBOL_GPL(ip_tunnel_init_net); 1085 1086 static void ip_tunnel_destroy(struct net *net, struct ip_tunnel_net *itn, 1087 struct list_head *head, 1088 struct rtnl_link_ops *ops) 1089 { 1090 struct net_device *dev, *aux; 1091 int h; 1092 1093 for_each_netdev_safe(net, dev, aux) 1094 if (dev->rtnl_link_ops == ops) 1095 unregister_netdevice_queue(dev, head); 1096 1097 for (h = 0; h < IP_TNL_HASH_SIZE; h++) { 1098 struct ip_tunnel *t; 1099 struct hlist_node *n; 1100 struct hlist_head *thead = &itn->tunnels[h]; 1101 1102 hlist_for_each_entry_safe(t, n, thead, hash_node) 1103 /* If dev is in the same netns, it has already 1104 * been added to the list by the previous loop. 1105 */ 1106 if (!net_eq(dev_net(t->dev), net)) 1107 unregister_netdevice_queue(t->dev, head); 1108 } 1109 } 1110 1111 void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id, 1112 struct rtnl_link_ops *ops) 1113 { 1114 struct ip_tunnel_net *itn; 1115 struct net *net; 1116 LIST_HEAD(list); 1117 1118 rtnl_lock(); 1119 list_for_each_entry(net, net_list, exit_list) { 1120 itn = net_generic(net, id); 1121 ip_tunnel_destroy(net, itn, &list, ops); 1122 } 1123 unregister_netdevice_many(&list); 1124 rtnl_unlock(); 1125 } 1126 EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets); 1127 1128 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 1129 struct ip_tunnel_parm *p, __u32 fwmark) 1130 { 1131 struct ip_tunnel *nt; 1132 struct net *net = dev_net(dev); 1133 struct ip_tunnel_net *itn; 1134 int mtu; 1135 int err; 1136 1137 nt = netdev_priv(dev); 1138 itn = net_generic(net, nt->ip_tnl_net_id); 1139 1140 if (nt->collect_md) { 1141 if (rtnl_dereference(itn->collect_md_tun)) 1142 return -EEXIST; 1143 } else { 1144 if (ip_tunnel_find(itn, p, dev->type)) 1145 return -EEXIST; 1146 } 1147 1148 nt->net = net; 1149 nt->parms = *p; 1150 nt->fwmark = fwmark; 1151 err = register_netdevice(dev); 1152 if (err) 1153 goto err_register_netdevice; 1154 1155 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) 1156 eth_hw_addr_random(dev); 1157 1158 mtu = ip_tunnel_bind_dev(dev); 1159 if (tb[IFLA_MTU]) { 1160 unsigned int max = IP_MAX_MTU - (nt->hlen + sizeof(struct iphdr)); 1161 1162 if (dev->type == ARPHRD_ETHER) 1163 max -= dev->hard_header_len; 1164 1165 mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, max); 1166 } 1167 1168 err = dev_set_mtu(dev, mtu); 1169 if (err) 1170 goto err_dev_set_mtu; 1171 1172 ip_tunnel_add(itn, nt); 1173 return 0; 1174 1175 err_dev_set_mtu: 1176 unregister_netdevice(dev); 1177 err_register_netdevice: 1178 return err; 1179 } 1180 EXPORT_SYMBOL_GPL(ip_tunnel_newlink); 1181 1182 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 1183 struct ip_tunnel_parm *p, __u32 fwmark) 1184 { 1185 struct ip_tunnel *t; 1186 struct ip_tunnel *tunnel = netdev_priv(dev); 1187 struct net *net = tunnel->net; 1188 struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id); 1189 1190 if (dev == itn->fb_tunnel_dev) 1191 return -EINVAL; 1192 1193 t = ip_tunnel_find(itn, p, dev->type); 1194 1195 if (t) { 1196 if (t->dev != dev) 1197 return -EEXIST; 1198 } else { 1199 t = tunnel; 1200 1201 if (dev->type != ARPHRD_ETHER) { 1202 unsigned int nflags = 0; 1203 1204 if (ipv4_is_multicast(p->iph.daddr)) 1205 nflags = IFF_BROADCAST; 1206 else if (p->iph.daddr) 1207 nflags = IFF_POINTOPOINT; 1208 1209 if ((dev->flags ^ nflags) & 1210 (IFF_POINTOPOINT | IFF_BROADCAST)) 1211 return -EINVAL; 1212 } 1213 } 1214 1215 ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU], fwmark); 1216 return 0; 1217 } 1218 EXPORT_SYMBOL_GPL(ip_tunnel_changelink); 1219 1220 int ip_tunnel_init(struct net_device *dev) 1221 { 1222 struct ip_tunnel *tunnel = netdev_priv(dev); 1223 struct iphdr *iph = &tunnel->parms.iph; 1224 int err; 1225 1226 dev->needs_free_netdev = true; 1227 dev->priv_destructor = ip_tunnel_dev_free; 1228 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1229 if (!dev->tstats) 1230 return -ENOMEM; 1231 1232 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); 1233 if (err) { 1234 free_percpu(dev->tstats); 1235 return err; 1236 } 1237 1238 err = gro_cells_init(&tunnel->gro_cells, dev); 1239 if (err) { 1240 dst_cache_destroy(&tunnel->dst_cache); 1241 free_percpu(dev->tstats); 1242 return err; 1243 } 1244 1245 tunnel->dev = dev; 1246 tunnel->net = dev_net(dev); 1247 strcpy(tunnel->parms.name, dev->name); 1248 iph->version = 4; 1249 iph->ihl = 5; 1250 1251 if (tunnel->collect_md) 1252 netif_keep_dst(dev); 1253 return 0; 1254 } 1255 EXPORT_SYMBOL_GPL(ip_tunnel_init); 1256 1257 void ip_tunnel_uninit(struct net_device *dev) 1258 { 1259 struct ip_tunnel *tunnel = netdev_priv(dev); 1260 struct net *net = tunnel->net; 1261 struct ip_tunnel_net *itn; 1262 1263 itn = net_generic(net, tunnel->ip_tnl_net_id); 1264 ip_tunnel_del(itn, netdev_priv(dev)); 1265 if (itn->fb_tunnel_dev == dev) 1266 WRITE_ONCE(itn->fb_tunnel_dev, NULL); 1267 1268 dst_cache_reset(&tunnel->dst_cache); 1269 } 1270 EXPORT_SYMBOL_GPL(ip_tunnel_uninit); 1271 1272 /* Do least required initialization, rest of init is done in tunnel_init call */ 1273 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id) 1274 { 1275 struct ip_tunnel *tunnel = netdev_priv(dev); 1276 tunnel->ip_tnl_net_id = net_id; 1277 } 1278 EXPORT_SYMBOL_GPL(ip_tunnel_setup); 1279 1280 MODULE_LICENSE("GPL"); 1281