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 -= (dev->hard_header_len + t_hlen); 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 - dev->hard_header_len - t_hlen; 351 ip_tunnel_add(itn, nt); 352 return nt; 353 354 err_dev_set_mtu: 355 unregister_netdevice(dev); 356 return ERR_PTR(err); 357 } 358 359 int ip_tunnel_rcv(struct ip_tunnel *tunnel, struct sk_buff *skb, 360 const struct tnl_ptk_info *tpi, struct metadata_dst *tun_dst, 361 bool log_ecn_error) 362 { 363 const struct iphdr *iph = ip_hdr(skb); 364 int err; 365 366 #ifdef CONFIG_NET_IPGRE_BROADCAST 367 if (ipv4_is_multicast(iph->daddr)) { 368 tunnel->dev->stats.multicast++; 369 skb->pkt_type = PACKET_BROADCAST; 370 } 371 #endif 372 373 if ((!(tpi->flags&TUNNEL_CSUM) && (tunnel->parms.i_flags&TUNNEL_CSUM)) || 374 ((tpi->flags&TUNNEL_CSUM) && !(tunnel->parms.i_flags&TUNNEL_CSUM))) { 375 tunnel->dev->stats.rx_crc_errors++; 376 tunnel->dev->stats.rx_errors++; 377 goto drop; 378 } 379 380 if (tunnel->parms.i_flags&TUNNEL_SEQ) { 381 if (!(tpi->flags&TUNNEL_SEQ) || 382 (tunnel->i_seqno && (s32)(ntohl(tpi->seq) - tunnel->i_seqno) < 0)) { 383 tunnel->dev->stats.rx_fifo_errors++; 384 tunnel->dev->stats.rx_errors++; 385 goto drop; 386 } 387 tunnel->i_seqno = ntohl(tpi->seq) + 1; 388 } 389 390 skb_reset_network_header(skb); 391 392 err = IP_ECN_decapsulate(iph, skb); 393 if (unlikely(err)) { 394 if (log_ecn_error) 395 net_info_ratelimited("non-ECT from %pI4 with TOS=%#x\n", 396 &iph->saddr, iph->tos); 397 if (err > 1) { 398 ++tunnel->dev->stats.rx_frame_errors; 399 ++tunnel->dev->stats.rx_errors; 400 goto drop; 401 } 402 } 403 404 dev_sw_netstats_rx_add(tunnel->dev, skb->len); 405 skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(tunnel->dev))); 406 407 if (tunnel->dev->type == ARPHRD_ETHER) { 408 skb->protocol = eth_type_trans(skb, tunnel->dev); 409 skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN); 410 } else { 411 skb->dev = tunnel->dev; 412 } 413 414 if (tun_dst) 415 skb_dst_set(skb, (struct dst_entry *)tun_dst); 416 417 gro_cells_receive(&tunnel->gro_cells, skb); 418 return 0; 419 420 drop: 421 if (tun_dst) 422 dst_release((struct dst_entry *)tun_dst); 423 kfree_skb(skb); 424 return 0; 425 } 426 EXPORT_SYMBOL_GPL(ip_tunnel_rcv); 427 428 int ip_tunnel_encap_add_ops(const struct ip_tunnel_encap_ops *ops, 429 unsigned int num) 430 { 431 if (num >= MAX_IPTUN_ENCAP_OPS) 432 return -ERANGE; 433 434 return !cmpxchg((const struct ip_tunnel_encap_ops **) 435 &iptun_encaps[num], 436 NULL, ops) ? 0 : -1; 437 } 438 EXPORT_SYMBOL(ip_tunnel_encap_add_ops); 439 440 int ip_tunnel_encap_del_ops(const struct ip_tunnel_encap_ops *ops, 441 unsigned int num) 442 { 443 int ret; 444 445 if (num >= MAX_IPTUN_ENCAP_OPS) 446 return -ERANGE; 447 448 ret = (cmpxchg((const struct ip_tunnel_encap_ops **) 449 &iptun_encaps[num], 450 ops, NULL) == ops) ? 0 : -1; 451 452 synchronize_net(); 453 454 return ret; 455 } 456 EXPORT_SYMBOL(ip_tunnel_encap_del_ops); 457 458 int ip_tunnel_encap_setup(struct ip_tunnel *t, 459 struct ip_tunnel_encap *ipencap) 460 { 461 int hlen; 462 463 memset(&t->encap, 0, sizeof(t->encap)); 464 465 hlen = ip_encap_hlen(ipencap); 466 if (hlen < 0) 467 return hlen; 468 469 t->encap.type = ipencap->type; 470 t->encap.sport = ipencap->sport; 471 t->encap.dport = ipencap->dport; 472 t->encap.flags = ipencap->flags; 473 474 t->encap_hlen = hlen; 475 t->hlen = t->encap_hlen + t->tun_hlen; 476 477 return 0; 478 } 479 EXPORT_SYMBOL_GPL(ip_tunnel_encap_setup); 480 481 static int tnl_update_pmtu(struct net_device *dev, struct sk_buff *skb, 482 struct rtable *rt, __be16 df, 483 const struct iphdr *inner_iph, 484 int tunnel_hlen, __be32 dst, bool md) 485 { 486 struct ip_tunnel *tunnel = netdev_priv(dev); 487 int pkt_size; 488 int mtu; 489 490 tunnel_hlen = md ? tunnel_hlen : tunnel->hlen; 491 pkt_size = skb->len - tunnel_hlen - dev->hard_header_len; 492 493 if (df) 494 mtu = dst_mtu(&rt->dst) - dev->hard_header_len 495 - sizeof(struct iphdr) - tunnel_hlen; 496 else 497 mtu = skb_valid_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu; 498 499 if (skb_valid_dst(skb)) 500 skb_dst_update_pmtu_no_confirm(skb, mtu); 501 502 if (skb->protocol == htons(ETH_P_IP)) { 503 if (!skb_is_gso(skb) && 504 (inner_iph->frag_off & htons(IP_DF)) && 505 mtu < pkt_size) { 506 memset(IPCB(skb), 0, sizeof(*IPCB(skb))); 507 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); 508 return -E2BIG; 509 } 510 } 511 #if IS_ENABLED(CONFIG_IPV6) 512 else if (skb->protocol == htons(ETH_P_IPV6)) { 513 struct rt6_info *rt6; 514 __be32 daddr; 515 516 rt6 = skb_valid_dst(skb) ? (struct rt6_info *)skb_dst(skb) : 517 NULL; 518 daddr = md ? dst : tunnel->parms.iph.daddr; 519 520 if (rt6 && mtu < dst_mtu(skb_dst(skb)) && 521 mtu >= IPV6_MIN_MTU) { 522 if ((daddr && !ipv4_is_multicast(daddr)) || 523 rt6->rt6i_dst.plen == 128) { 524 rt6->rt6i_flags |= RTF_MODIFIED; 525 dst_metric_set(skb_dst(skb), RTAX_MTU, mtu); 526 } 527 } 528 529 if (!skb_is_gso(skb) && mtu >= IPV6_MIN_MTU && 530 mtu < pkt_size) { 531 icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); 532 return -E2BIG; 533 } 534 } 535 #endif 536 return 0; 537 } 538 539 void ip_md_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 540 u8 proto, int tunnel_hlen) 541 { 542 struct ip_tunnel *tunnel = netdev_priv(dev); 543 u32 headroom = sizeof(struct iphdr); 544 struct ip_tunnel_info *tun_info; 545 const struct ip_tunnel_key *key; 546 const struct iphdr *inner_iph; 547 struct rtable *rt = NULL; 548 struct flowi4 fl4; 549 __be16 df = 0; 550 u8 tos, ttl; 551 bool use_cache; 552 553 tun_info = skb_tunnel_info(skb); 554 if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) || 555 ip_tunnel_info_af(tun_info) != AF_INET)) 556 goto tx_error; 557 key = &tun_info->key; 558 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 559 inner_iph = (const struct iphdr *)skb_inner_network_header(skb); 560 tos = key->tos; 561 if (tos == 1) { 562 if (skb->protocol == htons(ETH_P_IP)) 563 tos = inner_iph->tos; 564 else if (skb->protocol == htons(ETH_P_IPV6)) 565 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); 566 } 567 ip_tunnel_init_flow(&fl4, proto, key->u.ipv4.dst, key->u.ipv4.src, 568 tunnel_id_to_key32(key->tun_id), RT_TOS(tos), 569 0, skb->mark, skb_get_hash(skb)); 570 if (tunnel->encap.type != TUNNEL_ENCAP_NONE) 571 goto tx_error; 572 573 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 574 if (use_cache) 575 rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl4.saddr); 576 if (!rt) { 577 rt = ip_route_output_key(tunnel->net, &fl4); 578 if (IS_ERR(rt)) { 579 dev->stats.tx_carrier_errors++; 580 goto tx_error; 581 } 582 if (use_cache) 583 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 584 fl4.saddr); 585 } 586 if (rt->dst.dev == dev) { 587 ip_rt_put(rt); 588 dev->stats.collisions++; 589 goto tx_error; 590 } 591 592 if (key->tun_flags & TUNNEL_DONT_FRAGMENT) 593 df = htons(IP_DF); 594 if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, tunnel_hlen, 595 key->u.ipv4.dst, true)) { 596 ip_rt_put(rt); 597 goto tx_error; 598 } 599 600 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 601 ttl = key->ttl; 602 if (ttl == 0) { 603 if (skb->protocol == htons(ETH_P_IP)) 604 ttl = inner_iph->ttl; 605 else if (skb->protocol == htons(ETH_P_IPV6)) 606 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 607 else 608 ttl = ip4_dst_hoplimit(&rt->dst); 609 } 610 611 headroom += LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len; 612 if (headroom > dev->needed_headroom) 613 dev->needed_headroom = headroom; 614 615 if (skb_cow_head(skb, dev->needed_headroom)) { 616 ip_rt_put(rt); 617 goto tx_dropped; 618 } 619 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, proto, tos, ttl, 620 df, !net_eq(tunnel->net, dev_net(dev))); 621 return; 622 tx_error: 623 dev->stats.tx_errors++; 624 goto kfree; 625 tx_dropped: 626 dev->stats.tx_dropped++; 627 kfree: 628 kfree_skb(skb); 629 } 630 EXPORT_SYMBOL_GPL(ip_md_tunnel_xmit); 631 632 void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev, 633 const struct iphdr *tnl_params, u8 protocol) 634 { 635 struct ip_tunnel *tunnel = netdev_priv(dev); 636 struct ip_tunnel_info *tun_info = NULL; 637 const struct iphdr *inner_iph; 638 unsigned int max_headroom; /* The extra header space needed */ 639 struct rtable *rt = NULL; /* Route to the other host */ 640 bool use_cache = false; 641 struct flowi4 fl4; 642 bool md = false; 643 bool connected; 644 u8 tos, ttl; 645 __be32 dst; 646 __be16 df; 647 648 inner_iph = (const struct iphdr *)skb_inner_network_header(skb); 649 connected = (tunnel->parms.iph.daddr != 0); 650 651 memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); 652 653 dst = tnl_params->daddr; 654 if (dst == 0) { 655 /* NBMA tunnel */ 656 657 if (!skb_dst(skb)) { 658 dev->stats.tx_fifo_errors++; 659 goto tx_error; 660 } 661 662 tun_info = skb_tunnel_info(skb); 663 if (tun_info && (tun_info->mode & IP_TUNNEL_INFO_TX) && 664 ip_tunnel_info_af(tun_info) == AF_INET && 665 tun_info->key.u.ipv4.dst) { 666 dst = tun_info->key.u.ipv4.dst; 667 md = true; 668 connected = true; 669 } 670 else if (skb->protocol == htons(ETH_P_IP)) { 671 rt = skb_rtable(skb); 672 dst = rt_nexthop(rt, inner_iph->daddr); 673 } 674 #if IS_ENABLED(CONFIG_IPV6) 675 else if (skb->protocol == htons(ETH_P_IPV6)) { 676 const struct in6_addr *addr6; 677 struct neighbour *neigh; 678 bool do_tx_error_icmp; 679 int addr_type; 680 681 neigh = dst_neigh_lookup(skb_dst(skb), 682 &ipv6_hdr(skb)->daddr); 683 if (!neigh) 684 goto tx_error; 685 686 addr6 = (const struct in6_addr *)&neigh->primary_key; 687 addr_type = ipv6_addr_type(addr6); 688 689 if (addr_type == IPV6_ADDR_ANY) { 690 addr6 = &ipv6_hdr(skb)->daddr; 691 addr_type = ipv6_addr_type(addr6); 692 } 693 694 if ((addr_type & IPV6_ADDR_COMPATv4) == 0) 695 do_tx_error_icmp = true; 696 else { 697 do_tx_error_icmp = false; 698 dst = addr6->s6_addr32[3]; 699 } 700 neigh_release(neigh); 701 if (do_tx_error_icmp) 702 goto tx_error_icmp; 703 } 704 #endif 705 else 706 goto tx_error; 707 708 if (!md) 709 connected = false; 710 } 711 712 tos = tnl_params->tos; 713 if (tos & 0x1) { 714 tos &= ~0x1; 715 if (skb->protocol == htons(ETH_P_IP)) { 716 tos = inner_iph->tos; 717 connected = false; 718 } else if (skb->protocol == htons(ETH_P_IPV6)) { 719 tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph); 720 connected = false; 721 } 722 } 723 724 ip_tunnel_init_flow(&fl4, protocol, dst, tnl_params->saddr, 725 tunnel->parms.o_key, RT_TOS(tos), tunnel->parms.link, 726 tunnel->fwmark, skb_get_hash(skb)); 727 728 if (ip_tunnel_encap(skb, tunnel, &protocol, &fl4) < 0) 729 goto tx_error; 730 731 if (connected && md) { 732 use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); 733 if (use_cache) 734 rt = dst_cache_get_ip4(&tun_info->dst_cache, 735 &fl4.saddr); 736 } else { 737 rt = connected ? dst_cache_get_ip4(&tunnel->dst_cache, 738 &fl4.saddr) : NULL; 739 } 740 741 if (!rt) { 742 rt = ip_route_output_key(tunnel->net, &fl4); 743 744 if (IS_ERR(rt)) { 745 dev->stats.tx_carrier_errors++; 746 goto tx_error; 747 } 748 if (use_cache) 749 dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, 750 fl4.saddr); 751 else if (!md && connected) 752 dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst, 753 fl4.saddr); 754 } 755 756 if (rt->dst.dev == dev) { 757 ip_rt_put(rt); 758 dev->stats.collisions++; 759 goto tx_error; 760 } 761 762 df = tnl_params->frag_off; 763 if (skb->protocol == htons(ETH_P_IP) && !tunnel->ignore_df) 764 df |= (inner_iph->frag_off & htons(IP_DF)); 765 766 if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, 0, 0, false)) { 767 ip_rt_put(rt); 768 goto tx_error; 769 } 770 771 if (tunnel->err_count > 0) { 772 if (time_before(jiffies, 773 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) { 774 tunnel->err_count--; 775 776 dst_link_failure(skb); 777 } else 778 tunnel->err_count = 0; 779 } 780 781 tos = ip_tunnel_ecn_encap(tos, inner_iph, skb); 782 ttl = tnl_params->ttl; 783 if (ttl == 0) { 784 if (skb->protocol == htons(ETH_P_IP)) 785 ttl = inner_iph->ttl; 786 #if IS_ENABLED(CONFIG_IPV6) 787 else if (skb->protocol == htons(ETH_P_IPV6)) 788 ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit; 789 #endif 790 else 791 ttl = ip4_dst_hoplimit(&rt->dst); 792 } 793 794 max_headroom = LL_RESERVED_SPACE(rt->dst.dev) + sizeof(struct iphdr) 795 + rt->dst.header_len + ip_encap_hlen(&tunnel->encap); 796 if (max_headroom > dev->needed_headroom) 797 dev->needed_headroom = max_headroom; 798 799 if (skb_cow_head(skb, dev->needed_headroom)) { 800 ip_rt_put(rt); 801 dev->stats.tx_dropped++; 802 kfree_skb(skb); 803 return; 804 } 805 806 iptunnel_xmit(NULL, rt, skb, fl4.saddr, fl4.daddr, protocol, tos, ttl, 807 df, !net_eq(tunnel->net, dev_net(dev))); 808 return; 809 810 #if IS_ENABLED(CONFIG_IPV6) 811 tx_error_icmp: 812 dst_link_failure(skb); 813 #endif 814 tx_error: 815 dev->stats.tx_errors++; 816 kfree_skb(skb); 817 } 818 EXPORT_SYMBOL_GPL(ip_tunnel_xmit); 819 820 static void ip_tunnel_update(struct ip_tunnel_net *itn, 821 struct ip_tunnel *t, 822 struct net_device *dev, 823 struct ip_tunnel_parm *p, 824 bool set_mtu, 825 __u32 fwmark) 826 { 827 ip_tunnel_del(itn, t); 828 t->parms.iph.saddr = p->iph.saddr; 829 t->parms.iph.daddr = p->iph.daddr; 830 t->parms.i_key = p->i_key; 831 t->parms.o_key = p->o_key; 832 if (dev->type != ARPHRD_ETHER) { 833 memcpy(dev->dev_addr, &p->iph.saddr, 4); 834 memcpy(dev->broadcast, &p->iph.daddr, 4); 835 } 836 ip_tunnel_add(itn, t); 837 838 t->parms.iph.ttl = p->iph.ttl; 839 t->parms.iph.tos = p->iph.tos; 840 t->parms.iph.frag_off = p->iph.frag_off; 841 842 if (t->parms.link != p->link || t->fwmark != fwmark) { 843 int mtu; 844 845 t->parms.link = p->link; 846 t->fwmark = fwmark; 847 mtu = ip_tunnel_bind_dev(dev); 848 if (set_mtu) 849 dev->mtu = mtu; 850 } 851 dst_cache_reset(&t->dst_cache); 852 netdev_state_change(dev); 853 } 854 855 int ip_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p, int cmd) 856 { 857 int err = 0; 858 struct ip_tunnel *t = netdev_priv(dev); 859 struct net *net = t->net; 860 struct ip_tunnel_net *itn = net_generic(net, t->ip_tnl_net_id); 861 862 switch (cmd) { 863 case SIOCGETTUNNEL: 864 if (dev == itn->fb_tunnel_dev) { 865 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 866 if (!t) 867 t = netdev_priv(dev); 868 } 869 memcpy(p, &t->parms, sizeof(*p)); 870 break; 871 872 case SIOCADDTUNNEL: 873 case SIOCCHGTUNNEL: 874 err = -EPERM; 875 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 876 goto done; 877 if (p->iph.ttl) 878 p->iph.frag_off |= htons(IP_DF); 879 if (!(p->i_flags & VTI_ISVTI)) { 880 if (!(p->i_flags & TUNNEL_KEY)) 881 p->i_key = 0; 882 if (!(p->o_flags & TUNNEL_KEY)) 883 p->o_key = 0; 884 } 885 886 t = ip_tunnel_find(itn, p, itn->type); 887 888 if (cmd == SIOCADDTUNNEL) { 889 if (!t) { 890 t = ip_tunnel_create(net, itn, p); 891 err = PTR_ERR_OR_ZERO(t); 892 break; 893 } 894 895 err = -EEXIST; 896 break; 897 } 898 if (dev != itn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) { 899 if (t) { 900 if (t->dev != dev) { 901 err = -EEXIST; 902 break; 903 } 904 } else { 905 unsigned int nflags = 0; 906 907 if (ipv4_is_multicast(p->iph.daddr)) 908 nflags = IFF_BROADCAST; 909 else if (p->iph.daddr) 910 nflags = IFF_POINTOPOINT; 911 912 if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) { 913 err = -EINVAL; 914 break; 915 } 916 917 t = netdev_priv(dev); 918 } 919 } 920 921 if (t) { 922 err = 0; 923 ip_tunnel_update(itn, t, dev, p, true, 0); 924 } else { 925 err = -ENOENT; 926 } 927 break; 928 929 case SIOCDELTUNNEL: 930 err = -EPERM; 931 if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) 932 goto done; 933 934 if (dev == itn->fb_tunnel_dev) { 935 err = -ENOENT; 936 t = ip_tunnel_find(itn, p, itn->fb_tunnel_dev->type); 937 if (!t) 938 goto done; 939 err = -EPERM; 940 if (t == netdev_priv(itn->fb_tunnel_dev)) 941 goto done; 942 dev = t->dev; 943 } 944 unregister_netdevice(dev); 945 err = 0; 946 break; 947 948 default: 949 err = -EINVAL; 950 } 951 952 done: 953 return err; 954 } 955 EXPORT_SYMBOL_GPL(ip_tunnel_ctl); 956 957 int ip_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 958 { 959 struct ip_tunnel_parm p; 960 int err; 961 962 if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) 963 return -EFAULT; 964 err = dev->netdev_ops->ndo_tunnel_ctl(dev, &p, cmd); 965 if (!err && copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) 966 return -EFAULT; 967 return err; 968 } 969 EXPORT_SYMBOL_GPL(ip_tunnel_ioctl); 970 971 int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) 972 { 973 struct ip_tunnel *tunnel = netdev_priv(dev); 974 int t_hlen = tunnel->hlen + sizeof(struct iphdr); 975 int max_mtu = IP_MAX_MTU - dev->hard_header_len - t_hlen; 976 977 if (new_mtu < ETH_MIN_MTU) 978 return -EINVAL; 979 980 if (new_mtu > max_mtu) { 981 if (strict) 982 return -EINVAL; 983 984 new_mtu = max_mtu; 985 } 986 987 dev->mtu = new_mtu; 988 return 0; 989 } 990 EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu); 991 992 int ip_tunnel_change_mtu(struct net_device *dev, int new_mtu) 993 { 994 return __ip_tunnel_change_mtu(dev, new_mtu, true); 995 } 996 EXPORT_SYMBOL_GPL(ip_tunnel_change_mtu); 997 998 static void ip_tunnel_dev_free(struct net_device *dev) 999 { 1000 struct ip_tunnel *tunnel = netdev_priv(dev); 1001 1002 gro_cells_destroy(&tunnel->gro_cells); 1003 dst_cache_destroy(&tunnel->dst_cache); 1004 free_percpu(dev->tstats); 1005 } 1006 1007 void ip_tunnel_dellink(struct net_device *dev, struct list_head *head) 1008 { 1009 struct ip_tunnel *tunnel = netdev_priv(dev); 1010 struct ip_tunnel_net *itn; 1011 1012 itn = net_generic(tunnel->net, tunnel->ip_tnl_net_id); 1013 1014 if (itn->fb_tunnel_dev != dev) { 1015 ip_tunnel_del(itn, netdev_priv(dev)); 1016 unregister_netdevice_queue(dev, head); 1017 } 1018 } 1019 EXPORT_SYMBOL_GPL(ip_tunnel_dellink); 1020 1021 struct net *ip_tunnel_get_link_net(const struct net_device *dev) 1022 { 1023 struct ip_tunnel *tunnel = netdev_priv(dev); 1024 1025 return tunnel->net; 1026 } 1027 EXPORT_SYMBOL(ip_tunnel_get_link_net); 1028 1029 int ip_tunnel_get_iflink(const struct net_device *dev) 1030 { 1031 struct ip_tunnel *tunnel = netdev_priv(dev); 1032 1033 return tunnel->parms.link; 1034 } 1035 EXPORT_SYMBOL(ip_tunnel_get_iflink); 1036 1037 int ip_tunnel_init_net(struct net *net, unsigned int ip_tnl_net_id, 1038 struct rtnl_link_ops *ops, char *devname) 1039 { 1040 struct ip_tunnel_net *itn = net_generic(net, ip_tnl_net_id); 1041 struct ip_tunnel_parm parms; 1042 unsigned int i; 1043 1044 itn->rtnl_link_ops = ops; 1045 for (i = 0; i < IP_TNL_HASH_SIZE; i++) 1046 INIT_HLIST_HEAD(&itn->tunnels[i]); 1047 1048 if (!ops || !net_has_fallback_tunnels(net)) { 1049 struct ip_tunnel_net *it_init_net; 1050 1051 it_init_net = net_generic(&init_net, ip_tnl_net_id); 1052 itn->type = it_init_net->type; 1053 itn->fb_tunnel_dev = NULL; 1054 return 0; 1055 } 1056 1057 memset(&parms, 0, sizeof(parms)); 1058 if (devname) 1059 strlcpy(parms.name, devname, IFNAMSIZ); 1060 1061 rtnl_lock(); 1062 itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); 1063 /* FB netdevice is special: we have one, and only one per netns. 1064 * Allowing to move it to another netns is clearly unsafe. 1065 */ 1066 if (!IS_ERR(itn->fb_tunnel_dev)) { 1067 itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; 1068 itn->fb_tunnel_dev->mtu = ip_tunnel_bind_dev(itn->fb_tunnel_dev); 1069 ip_tunnel_add(itn, netdev_priv(itn->fb_tunnel_dev)); 1070 itn->type = itn->fb_tunnel_dev->type; 1071 } 1072 rtnl_unlock(); 1073 1074 return PTR_ERR_OR_ZERO(itn->fb_tunnel_dev); 1075 } 1076 EXPORT_SYMBOL_GPL(ip_tunnel_init_net); 1077 1078 static void ip_tunnel_destroy(struct net *net, struct ip_tunnel_net *itn, 1079 struct list_head *head, 1080 struct rtnl_link_ops *ops) 1081 { 1082 struct net_device *dev, *aux; 1083 int h; 1084 1085 for_each_netdev_safe(net, dev, aux) 1086 if (dev->rtnl_link_ops == ops) 1087 unregister_netdevice_queue(dev, head); 1088 1089 for (h = 0; h < IP_TNL_HASH_SIZE; h++) { 1090 struct ip_tunnel *t; 1091 struct hlist_node *n; 1092 struct hlist_head *thead = &itn->tunnels[h]; 1093 1094 hlist_for_each_entry_safe(t, n, thead, hash_node) 1095 /* If dev is in the same netns, it has already 1096 * been added to the list by the previous loop. 1097 */ 1098 if (!net_eq(dev_net(t->dev), net)) 1099 unregister_netdevice_queue(t->dev, head); 1100 } 1101 } 1102 1103 void ip_tunnel_delete_nets(struct list_head *net_list, unsigned int id, 1104 struct rtnl_link_ops *ops) 1105 { 1106 struct ip_tunnel_net *itn; 1107 struct net *net; 1108 LIST_HEAD(list); 1109 1110 rtnl_lock(); 1111 list_for_each_entry(net, net_list, exit_list) { 1112 itn = net_generic(net, id); 1113 ip_tunnel_destroy(net, itn, &list, ops); 1114 } 1115 unregister_netdevice_many(&list); 1116 rtnl_unlock(); 1117 } 1118 EXPORT_SYMBOL_GPL(ip_tunnel_delete_nets); 1119 1120 int ip_tunnel_newlink(struct net_device *dev, struct nlattr *tb[], 1121 struct ip_tunnel_parm *p, __u32 fwmark) 1122 { 1123 struct ip_tunnel *nt; 1124 struct net *net = dev_net(dev); 1125 struct ip_tunnel_net *itn; 1126 int mtu; 1127 int err; 1128 1129 nt = netdev_priv(dev); 1130 itn = net_generic(net, nt->ip_tnl_net_id); 1131 1132 if (nt->collect_md) { 1133 if (rtnl_dereference(itn->collect_md_tun)) 1134 return -EEXIST; 1135 } else { 1136 if (ip_tunnel_find(itn, p, dev->type)) 1137 return -EEXIST; 1138 } 1139 1140 nt->net = net; 1141 nt->parms = *p; 1142 nt->fwmark = fwmark; 1143 err = register_netdevice(dev); 1144 if (err) 1145 goto err_register_netdevice; 1146 1147 if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS]) 1148 eth_hw_addr_random(dev); 1149 1150 mtu = ip_tunnel_bind_dev(dev); 1151 if (tb[IFLA_MTU]) { 1152 unsigned int max = IP_MAX_MTU - dev->hard_header_len - nt->hlen; 1153 1154 mtu = clamp(dev->mtu, (unsigned int)ETH_MIN_MTU, 1155 (unsigned int)(max - sizeof(struct iphdr))); 1156 } 1157 1158 err = dev_set_mtu(dev, mtu); 1159 if (err) 1160 goto err_dev_set_mtu; 1161 1162 ip_tunnel_add(itn, nt); 1163 return 0; 1164 1165 err_dev_set_mtu: 1166 unregister_netdevice(dev); 1167 err_register_netdevice: 1168 return err; 1169 } 1170 EXPORT_SYMBOL_GPL(ip_tunnel_newlink); 1171 1172 int ip_tunnel_changelink(struct net_device *dev, struct nlattr *tb[], 1173 struct ip_tunnel_parm *p, __u32 fwmark) 1174 { 1175 struct ip_tunnel *t; 1176 struct ip_tunnel *tunnel = netdev_priv(dev); 1177 struct net *net = tunnel->net; 1178 struct ip_tunnel_net *itn = net_generic(net, tunnel->ip_tnl_net_id); 1179 1180 if (dev == itn->fb_tunnel_dev) 1181 return -EINVAL; 1182 1183 t = ip_tunnel_find(itn, p, dev->type); 1184 1185 if (t) { 1186 if (t->dev != dev) 1187 return -EEXIST; 1188 } else { 1189 t = tunnel; 1190 1191 if (dev->type != ARPHRD_ETHER) { 1192 unsigned int nflags = 0; 1193 1194 if (ipv4_is_multicast(p->iph.daddr)) 1195 nflags = IFF_BROADCAST; 1196 else if (p->iph.daddr) 1197 nflags = IFF_POINTOPOINT; 1198 1199 if ((dev->flags ^ nflags) & 1200 (IFF_POINTOPOINT | IFF_BROADCAST)) 1201 return -EINVAL; 1202 } 1203 } 1204 1205 ip_tunnel_update(itn, t, dev, p, !tb[IFLA_MTU], fwmark); 1206 return 0; 1207 } 1208 EXPORT_SYMBOL_GPL(ip_tunnel_changelink); 1209 1210 int ip_tunnel_init(struct net_device *dev) 1211 { 1212 struct ip_tunnel *tunnel = netdev_priv(dev); 1213 struct iphdr *iph = &tunnel->parms.iph; 1214 int err; 1215 1216 dev->needs_free_netdev = true; 1217 dev->priv_destructor = ip_tunnel_dev_free; 1218 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 1219 if (!dev->tstats) 1220 return -ENOMEM; 1221 1222 err = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL); 1223 if (err) { 1224 free_percpu(dev->tstats); 1225 return err; 1226 } 1227 1228 err = gro_cells_init(&tunnel->gro_cells, dev); 1229 if (err) { 1230 dst_cache_destroy(&tunnel->dst_cache); 1231 free_percpu(dev->tstats); 1232 return err; 1233 } 1234 1235 tunnel->dev = dev; 1236 tunnel->net = dev_net(dev); 1237 strcpy(tunnel->parms.name, dev->name); 1238 iph->version = 4; 1239 iph->ihl = 5; 1240 1241 if (tunnel->collect_md) 1242 netif_keep_dst(dev); 1243 return 0; 1244 } 1245 EXPORT_SYMBOL_GPL(ip_tunnel_init); 1246 1247 void ip_tunnel_uninit(struct net_device *dev) 1248 { 1249 struct ip_tunnel *tunnel = netdev_priv(dev); 1250 struct net *net = tunnel->net; 1251 struct ip_tunnel_net *itn; 1252 1253 itn = net_generic(net, tunnel->ip_tnl_net_id); 1254 ip_tunnel_del(itn, netdev_priv(dev)); 1255 if (itn->fb_tunnel_dev == dev) 1256 WRITE_ONCE(itn->fb_tunnel_dev, NULL); 1257 1258 dst_cache_reset(&tunnel->dst_cache); 1259 } 1260 EXPORT_SYMBOL_GPL(ip_tunnel_uninit); 1261 1262 /* Do least required initialization, rest of init is done in tunnel_init call */ 1263 void ip_tunnel_setup(struct net_device *dev, unsigned int net_id) 1264 { 1265 struct ip_tunnel *tunnel = netdev_priv(dev); 1266 tunnel->ip_tnl_net_id = net_id; 1267 } 1268 EXPORT_SYMBOL_GPL(ip_tunnel_setup); 1269 1270 MODULE_LICENSE("GPL"); 1271