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), dev_net(dev), 298 tunnel->parms.link, 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 dev_net(dev), 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), 730 dev_net(dev), tunnel->parms.link, 731 tunnel->fwmark, skb_get_hash(skb)); 732 733 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) 734 goto tx_error; 735 736 if (connected && md) { 737 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 738 if (use_cache) 739 rt = dst_cache_get_ip4(&tun_info->dst_cache, 740 &fl4.saddr); 741 } else { 742 rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, 743 &fl4.saddr) : NULL; 744 } 745 746 if (!rt) { 747 rt = ip_route_output_key(tunnel->net, &fl4); 748 749 if (IS_ERR(rt)) { 750 dev->stats.tx_carrier_errors++; 751 goto tx_error; 752 } 753 if (use_cache) 754 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 755 fl4.saddr); 756 else if (!md && connected) 757 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, 758 fl4.saddr); 759 } 760 761 if (rt->dst.dev == dev) { 762 ip_rt_put(rt); 763 dev->stats.collisions++; 764 goto tx_error; 765 } 766 767 df = tnl_params->frag_off; 768 if (skb->protocol == htons(ETH_P_IP) && !tunnel->ignore_df) 769 df |= (inner_iph->frag_off & htons(IP_DF)); 770 771 if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, 0, 0, false)) { 772 ip_rt_put(rt); 773 goto tx_error; 774 } 775 776 if (tunnel->err_count > 0) { 777 if (time_before(jiffies, 778 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 779 tunnel->err_count--; 780 781 dst_link_failure(skb); 782 } else 783 tunnel->err_count = 0; 784 } 785 786 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 787 ttl = tnl_params->ttl; 788 if (ttl == 0) { 789 if (skb->protocol == htons(ETH_P_IP)) 790 ttl = inner_iph->ttl; 791 #if IS_ENABLED(CONFIG_IPV6) 792 else if (skb->protocol == htons(ETH_P_IPV6)) 793 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 794 #endif 795 else 796 ttl = ip4_dst_hoplimit(&rt->dst); 797 } 798 799 max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) 800 + rt->dst.header_len + ip_encap_hlen(&tunnel->encap); 801 if (max_headroom > dev->needed_headroom) 802 dev->needed_headroom = max_headroom; 803 804 if (skb_cow_head(skb, dev->needed_headroom)) { 805 ip_rt_put(rt); 806 dev->stats.tx_dropped++; 807 kfree_skb(skb); 808 return; 809 } 810 811 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, 812 df, !net_eq(tunnel->net, dev_net(dev))); 813 return; 814 815 #if IS_ENABLED(CONFIG_IPV6) 816 tx_error_icmp: 817 dst_link_failure(skb); 818 #endif 819 tx_error: 820 dev->stats.tx_errors++; 821 kfree_skb(skb); 822 } 823 EXPORT_SYMBOL_GPL(ip_tunnel_xmit); 824 825 static void ip_tunnel_update(struct ip_tunnel_net *itn, 826 struct ip_tunnel *t, 827 struct net_device *dev, 828 struct ip_tunnel_parm *p, 829 bool set_mtu, 830 __u32 fwmark) 831 { 832 ip_tunnel_del(itn, t); 833 t->parms.iph.saddr = p->iph.saddr; 834 t->parms.iph.daddr = p->iph.daddr; 835 t->parms.i_key = p->i_key; 836 t->parms.o_key = p->o_key; 837 if (dev->type != ARPHRD_ETHER) { 838 __dev_addr_set(dev, &p->iph.saddr, 4); 839 memcpy(dev->broadcast, &p->iph.daddr, 4); 840 } 841 ip_tunnel_add(itn, t); 842 843 t->parms.iph.ttl = p->iph.ttl; 844 t->parms.iph.tos = p->iph.tos; 845 t->parms.iph.frag_off = p->iph.frag_off; 846 847 if (t->parms.link != p->link || t->fwmark != fwmark) { 848 int mtu; 849 850 t->parms.link = p->link; 851 t->fwmark = fwmark; 852 mtu = ip_tunnel_bind_dev(dev); 853 if (set_mtu) 854 dev->mtu = mtu; 855 } 856 dst_cache_reset(&t->dst_cache); 857 netdev_state_change(dev); 858 } 859 860 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) 861 { 862 int err = 0; 863 struct ip_tunnel *t = netdev_priv(dev); 864 struct net *net = t->net; 865 struct ip_tunnel_net *itn = net_generic(net, t->ip_tnl_net_id); 866 867 switch (cmd) { 868 case SIOCGETTUNNEL: 869 if (dev == itn->fb_tunnel_dev) { 870 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 871 if (!t) 872 t = netdev_priv(dev); 873 } 874 memcpy(p, &t->parms, sizeof(*p)); 875 break; 876 877 case SIOCADDTUNNEL: 878 case SIOCCHGTUNNEL: 879 err = -EPERM; 880 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 881 goto done; 882 if (p->iph.ttl) 883 p->iph.frag_off |= htons(IP_DF); 884 if (!(p->i_flags & VTI_ISVTI)) { 885 if (!(p->i_flags & TUNNEL_KEY)) 886 p->i_key = 0; 887 if (!(p->o_flags & TUNNEL_KEY)) 888 p->o_key = 0; 889 } 890 891 t = ip_tunnel_find(itn, p, itn->type); 892 893 if (cmd == SIOCADDTUNNEL) { 894 if (!t) { 895 t = ip_tunnel_create(net, itn, p); 896 err = PTR_ERR_OR_ZERO(t); 897 break; 898 } 899 900 err = -EEXIST; 901 break; 902 } 903 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 904 if (t) { 905 if (t->dev != dev) { 906 err = -EEXIST; 907 break; 908 } 909 } else { 910 unsigned int nflags = 0; 911 912 if (ipv4_is_multicast(p->iph.daddr)) 913 nflags = IFF_BROADCAST; 914 else if (p->iph.daddr) 915 nflags = IFF_POINTOPOINT; 916 917 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { 918 err = -EINVAL; 919 break; 920 } 921 922 t = netdev_priv(dev); 923 } 924 } 925 926 if (t) { 927 err = 0; 928 ip_tunnel_update(itn, t, dev, p, true, 0); 929 } else { 930 err = -ENOENT; 931 } 932 break; 933 934 case SIOCDELTUNNEL: 935 err = -EPERM; 936 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 937 goto done; 938 939 if (dev == itn->fb_tunnel_dev) { 940 err = -ENOENT; 941 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 942 if (!t) 943 goto done; 944 err = -EPERM; 945 if (t == netdev_priv(itn->fb_tunnel_dev)) 946 goto done; 947 dev = t->dev; 948 } 949 unregister_netdevice(dev); 950 err = 0; 951 break; 952 953 default: 954 err = -EINVAL; 955 } 956 957 done: 958 return err; 959 } 960 EXPORT_SYMBOL_GPL(ip_tunnel_ctl); 961 962 int ip_tunnel_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 963 void __user *data, int cmd) 964 { 965 struct ip_tunnel_parm p; 966 int err; 967 968 if (copy_from_user(&p, data, sizeof(p))) 969 return -EFAULT; 970 err = dev->netdev_ops->ndo_tunnel_ctl(dev, &p, cmd); 971 if (!err && copy_to_user(data, &p, sizeof(p))) 972 return -EFAULT; 973 return err; 974 } 975 EXPORT_SYMBOL_GPL(ip_tunnel_siocdevprivate); 976 977 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) 978 { 979 struct ip_tunnel *tunnel = netdev_priv(dev); 980 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 981 int max_mtu = IP_MAX_MTU - t_hlen; 982 983 if (dev->type == ARPHRD_ETHER) 984 max_mtu -= dev->hard_header_len; 985 986 if (new_mtu < ETH_MIN_MTU) 987 return -EINVAL; 988 989 if (new_mtu > max_mtu) { 990 if (strict) 991 return -EINVAL; 992 993 new_mtu = max_mtu; 994 } 995 996 dev->mtu = new_mtu; 997 return 0; 998 } 999 EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu); 1000 1001 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 1002 { 1003 return __ip_tunnel_change_mtu(dev, new_mtu, true); 1004 } 1005 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu); 1006 1007 static void ip_tunnel_dev_free(struct net_device *dev) 1008 { 1009 struct ip_tunnel *tunnel = netdev_priv(dev); 1010 1011 gro_cells_destroy(&tunnel->gro_cells); 1012 dst_cache_destroy(&tunnel->dst_cache); 1013 free_percpu(dev->tstats); 1014 } 1015 1016 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) 1017 { 1018 struct ip_tunnel *tunnel = netdev_priv(dev); 1019 struct ip_tunnel_net *itn; 1020 1021 itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); 1022 1023 if (itn->fb_tunnel_dev != dev) { 1024 ip_tunnel_del(itn, netdev_priv(dev)); 1025 unregister_netdevice_queue(dev, head); 1026 } 1027 } 1028 EXPORT_SYMBOL_GPL(ip_tunnel_dellink); 1029 1030 struct net *ip_tunnel_get_link_net(const struct net_device *dev) 1031 { 1032 struct ip_tunnel *tunnel = netdev_priv(dev); 1033 1034 return tunnel->net; 1035 } 1036 EXPORT_SYMBOL(ip_tunnel_get_link_net); 1037 1038 int ip_tunnel_get_iflink(const struct net_device *dev) 1039 { 1040 struct ip_tunnel *tunnel = netdev_priv(dev); 1041 1042 return tunnel->parms.link; 1043 } 1044 EXPORT_SYMBOL(ip_tunnel_get_iflink); 1045 1046 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 1047 struct rtnl_link_ops *ops, char *devname) 1048 { 1049 struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id); 1050 struct ip_tunnel_parm parms; 1051 unsigned int i; 1052 1053 itn->rtnl_link_ops = ops; 1054 for (i = 0; i < IP_TNL_HASH_SIZE; i++) 1055 INIT_HLIST_HEAD(&itn->tunnels[i]); 1056 1057 if (!ops || !net_has_fallback_tunnels(net)) { 1058 struct ip_tunnel_net *it_init_net; 1059 1060 it_init_net = net_generic(&init_net, ip_tnl_net_id); 1061 itn->type = it_init_net->type; 1062 itn->fb_tunnel_dev = NULL; 1063 return 0; 1064 } 1065 1066 memset(&parms, 0, sizeof(parms)); 1067 if (devname) 1068 strlcpy(parms.name, devname, IFNAMSIZ); 1069 1070 rtnl_lock(); 1071 itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); 1072 /* FB netdevice is special: we have one, and only one per netns. 1073 * Allowing to move it to another netns is clearly unsafe. 1074 */ 1075 if (!IS_ERR(itn->fb_tunnel_dev)) { 1076 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1077 itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev); 1078 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev)); 1079 itn->type = itn->fb_tunnel_dev->type; 1080 } 1081 rtnl_unlock(); 1082 1083 return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev); 1084 } 1085 EXPORT_SYMBOL_GPL(ip_tunnel_init_net); 1086 1087 static void ip_tunnel_destroy(struct net *net, struct ip_tunnel_net *itn, 1088 struct list_head *head, 1089 struct rtnl_link_ops *ops) 1090 { 1091 struct net_device *dev, *aux; 1092 int h; 1093 1094 for_each_netdev_safe(net, dev, aux) 1095 if (dev->rtnl_link_ops == ops) 1096 unregister_netdevice_queue(dev, head); 1097 1098 for (h = 0; h < IP_TNL_HASH_SIZE; h++) { 1099 struct ip_tunnel *t; 1100 struct hlist_node *n; 1101 struct hlist_head *thead = &itn->tunnels[h]; 1102 1103 hlist_for_each_entry_safe(t, n, thead, hash_node) 1104 /* If dev is in the same netns, it has already 1105 * been added to the list by the previous loop. 1106 */ 1107 if (!net_eq(dev_net(t->dev), net)) 1108 unregister_netdevice_queue(t->dev, head); 1109 } 1110 } 1111 1112 void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id, 1113 struct rtnl_link_ops *ops) 1114 { 1115 struct ip_tunnel_net *itn; 1116 struct net *net; 1117 LIST_HEAD(list); 1118 1119 rtnl_lock(); 1120 list_for_each_entry(net, net_list, exit_list) { 1121 itn = net_generic(net, id); 1122 ip_tunnel_destroy(net, itn, &list, ops); 1123 } 1124 unregister_netdevice_many(&list); 1125 rtnl_unlock(); 1126 } 1127 EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets); 1128 1129 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 1130 struct ip_tunnel_parm *p, __u32 fwmark) 1131 { 1132 struct ip_tunnel *nt; 1133 struct net *net = dev_net(dev); 1134 struct ip_tunnel_net *itn; 1135 int mtu; 1136 int err; 1137 1138 nt = netdev_priv(dev); 1139 itn = net_generic(net, nt->ip_tnl_net_id); 1140 1141 if (nt->collect_md) { 1142 if (rtnl_dereference(itn->collect_md_tun)) 1143 return -EEXIST; 1144 } else { 1145 if (ip_tunnel_find(itn, p, dev->type)) 1146 return -EEXIST; 1147 } 1148 1149 nt->net = net; 1150 nt->parms = *p; 1151 nt->fwmark = fwmark; 1152 err = register_netdevice(dev); 1153 if (err) 1154 goto err_register_netdevice; 1155 1156 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) 1157 eth_hw_addr_random(dev); 1158 1159 mtu = ip_tunnel_bind_dev(dev); 1160 if (tb[IFLA_MTU]) { 1161 unsigned int max = IP_MAX_MTU - (nt->hlen + sizeof(struct iphdr)); 1162 1163 if (dev->type == ARPHRD_ETHER) 1164 max -= dev->hard_header_len; 1165 1166 mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, max); 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 netif_keep_dst(dev); 1254 return 0; 1255 } 1256 EXPORT_SYMBOL_GPL(ip_tunnel_init); 1257 1258 void ip_tunnel_uninit(struct net_device *dev) 1259 { 1260 struct ip_tunnel *tunnel = netdev_priv(dev); 1261 struct net *net = tunnel->net; 1262 struct ip_tunnel_net *itn; 1263 1264 itn = net_generic(net, tunnel->ip_tnl_net_id); 1265 ip_tunnel_del(itn, netdev_priv(dev)); 1266 if (itn->fb_tunnel_dev == dev) 1267 WRITE_ONCE(itn->fb_tunnel_dev, NULL); 1268 1269 dst_cache_reset(&tunnel->dst_cache); 1270 } 1271 EXPORT_SYMBOL_GPL(ip_tunnel_uninit); 1272 1273 /* Do least required initialization, rest of init is done in tunnel_init call */ 1274 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id) 1275 { 1276 struct ip_tunnel *tunnel = netdev_priv(dev); 1277 tunnel->ip_tnl_net_id = net_id; 1278 } 1279 EXPORT_SYMBOL_GPL(ip_tunnel_setup); 1280 1281 MODULE_LICENSE("GPL"); 1282